Lecture Notes for Bio 106

Reproductive roles Male’s job is to get the sperm to the egg The sperm are specialized to deliver the male’s genes to the egg Female’s job is to produce a gamete (egg) containing the female’s genes Egg is specialized to nourish the embryo Egg is large and contains nutrients Egg must be moved along Female must also nourish and protect the embryo and fetus This is the job of the uterus Male reproductive strategy: Produce millions of gametes and hope that one makes it to the egg Female reproductive strategy: Invest heavily in one gamete and nourish and protect it Egg Cell (Ovum; 1 copy each chromosome) Sperm Cell (1 copy of each chromosome) MEIOSIS (a type of cell division that begins with a cell with 2 copies of each chromosome and ends with 4 cells with 1 copy of each chromosome) FERTLIZATION (Fusion of Egg and Sperm nuclei; creates a cell with 2 copies of each chromosome) Zygote (cell formed by fusion of egg and sperm; has 2 copies of each chromosome; will develop into new individual) Ovary (in female) Testis (in male) 1 Gonads: a. Testes in male b. Ovaries in females 1. roduce gametes Male = sperm Female = ovum or egg join zygote; new individual 2. produce sex hormones testosterone estrogen + progesterone Male Reproductive System Testes located in scrotum why? sperm don't survive well at body temperature is 3-4o F cooler temp kept constant by reflex how? – pass through the inguinal canal before birth hole usually closed over with connective tissue possible problems 1. cryptorchidism failure of the testes to descend if not corrected, results in sterility corrected by surgery or by administering hormones 2. inguinal hernia inguinal canal does not completely close intestine may push into opening correct with surgery more common in men but may occur in women Inside Testes 1. eminiferous tubules about 1000 site where sperm are produced by a process called spermatogenesis produce 100 million+ sperm each day from puberty until death spermatogenesis A. takes place in an orderly progression from the outside edge of seminiferous tubule to inside (lumen) B. involves changes in genetic information and changes in the shape and functioning of cell sperm carry father’s genetic contribution to next offspring body cells have 2 copies of each chromosome (1 from Mom & 1 from Dad) gametes (egg or sperm) can have only 1 copy of each chromosome meiosis = the type of cell division that produces gametes 1 cell with 2 copies of each chromosome Meiosis spermatogenesis 4 cells with 1 copy of each chromosome Sperm Structure 2 designed to deliver male’s genetic contribution to next generation 1.Head – contains male’s genetic contribution to next generation; almost all nucleus 2. Acrosome – a sac containing enzymes to will allow the sperm to digest the outer layers around egg so sperm nucleus can reach egg nucleus 3. Mitochondria – energy to fuel the trip to egg 4. Tail (or flagellum) has contractile fibers for motility; allows the sperm to swim to egg 2. interstitial cells – produce male sex hormone – testosterone Still in testis – between seminiferous tubules Beginning at puberty these cells secrete testosterone They are stimulated to secrete testosterone by LH, a hormone produced by the anterior pituitary gland LH (from anterior pituitary) stimulates the release of testosteroneHORMONES chemical messengers produced by certain glands and released into the blood hormone reaches all cells only cells with a receptor for that hormone can respond a cell responds by doing what that cell does it might divide it might produce a chemical it might increase rate of certain chemical reactions so hormones have different effects on different cells cells without receptors for that hormone cannot respond 3 Cell 1 (with receptor) Effect 1 Cell 2 (with receptor) Effect 2 Hormone Into blood supply throughout body Cell 3 (with receptor) Effect 3 Cell 4 (no rec eptor) No Effect Testosterone causes: development of male reproductive apparatus sperm maturation secondary sex characteristics sex drive (in part) Possible problems with testes Testicular cancer: most common in males 25-30 yrs. more common if testes did not descend after 6 yrs. may be hereditary usually does not cause pain Practice self exam! Feel for small lump Best done after a hot shower Sperm next enter a system of tubes to store and transport sperm 1. pididymis: tube about 20 feet long stores sperm sperm mature here, sperm change size and shape, metabolism changes, sperm become capable of moving but don't yet. sperm moved along by peristalsis (a wave of muscle contraction) 2. vas deferens: sperm duct conducts sperm from epididymis to urethra 3. urethra: conducts sperm to outside of body, also conducts urine but never at same time Accessory Glands: 1. Bulbourethral glands mucous secretion just before ejaculation lubricant? Buffers to adjust pH of urethra 2. Prostate gland secre tes fluid, milky color alkaline activates sperm counteracts acidity of female reproductive tract Possible problems with prostate 1. enlarges in older men difficulty urinating & decreased bladder volume 2. rostate cancer grows slowly can spread detected by: rectal exam and blood test for PSA (prostate specific antigen) 4 3. Seminal vesicles make up most of the volume of semen secretion probably nourishes sperm (contains fructose, vitamin C, amino acids, prostaglandins) Result = semen Semen: secretions of accessory glands and sperm about 1 tsp. per ejaculation, about 20 % sperm Functions: transport sperm lubricate passageways nourish sperm decrease acidity of female reproductive tract Penis: Functions: transfer sperm to female conducts sperm outside body tip is enlarged = glans penis (rich in sensory endings) Mechanism of erection 3 columns of spongy tissue arteries dilate ? increase blood delivery veins close down blood accumulatesErectile Dysfunction = Impotence inability to achieve or maintain an erection common problem many possible causes – both physical and emotional drugs now available to help a man have an erection when he is sexually stimulated (e. g. Viagra, Cialis, Levitra) These inhibit the breakdown of the neurotransmitter that causes the arteries in penis to dilate arteries are dilated longer increases and prolongs blood entering the penis ? erection Female Reproductive System gonads = 2 ovaries 1. produce eggs or ova (singular = ovum) egg is specialized to provide nourishment for early embryo large cell full of nutrients 2. produce female hormones: estrogen progesterone Female also nourishes and protects the developing embryo and fetus = job of the uterus 5 Ovarian Cycle = series of events in the ovary that leads to production of egg, estrogen & progesterone 1. ollicle maturation primary follicle = an immature egg surrounded by a layer of follicle cells as follicle matures the immature egg gets larger follicle cells divide and form many lay ers around egg follicle cells secrete estrogen mature follicle egg completes first meiotic division layers of follicle cells splits forming a central cavity filled with fluid containing estrogen egg pushed to side with layer of follicle cells 2. ovulation = release of immature egg from ovary egg released with layer of follicle cells around it rest of follicle cells stay in ovary 3. corpus luteum forms from follicle cells remaining in ovary corpus luteum secretes estrogen and progesteroneOVARY primary follicle (immature egg surrounded by follicle cells) mature follicle (many layers of follicle cells, fluid filled cavity, egg surrounded by follicle cells) after ovulation follicle cells remaining in ovary become corpus luteum estrogen progesterone egg 1. estrogen maturation of egg development and maintenance of reproductive structures cell division: thickens lining of uterus also occurs in breast tissue secondary sex characteristics pubic hair armpit hair broader pelvis breast developm ent 2. progesterone prepares uterus for egg implantation maintains pregnancy 6 Oogenesis = the process by which an egg (ovum) is formed Meiosis: starts with a cell that has 2 copies of every chromosome ends with up to 4 cells with 1 copy of every chromosome 1 egg (ovum) and 3 non functional polar bodies IN FEMALES MEIOSIS IS NOT A CONTINUOUS PROCESS Preparations begin efore birth in all potential eggs Then development stops Beginning at puberty, 1 egg continues to the next stage of development The egg is ovulated (released from the ovary) Meiosis is completed ONLY if the egg is fertilized) Number of ova At puberty: potential for about 400,000 eggs Usually 1 each month develops in each monthly cycle (if 2 form and both are fertilized get fraternal twins) total egg production ~ 450 eggs in lifetime menopause – rest of potential eggs have degenerated Oviducts (Fallopian tubes tubes that conduct the egg to the uterus – takes about 3 days open end enlarged and fringed †“ increased surface area for catching egg cilia line oviducts to help move egg along fertilization – usually in upper third of oviduct ectopic pregnancy – usually a tubal pregnancy early embryo implants and begins development at site other than uterus usually in Fallopian tube (oviduct) dangerous to mother – must be terminated Uterus provides nourishment & protects the developing embryo and fetus A. Cervix – tubular portion the extends into vagina has opening through which sperm enter and baby exits B. Body – region in which fetus develops 1.Endometrium – lining site where embryo implants built up each month cell division makes it thicker becomes more vascular (more blood vessels) glands develop that provide nutritious material then lost as menstrual fluid (woman gets her period) 2. muscle allows uterus to expand as fetus grows 60X bigger at full term pregnancy 7 provides force to push baby out Possible problems with uterus: 1. Pelvic Infl ammatory Disease (PID): any bacterial infection of pelvic organs especially uterus, oviducts, ovaries; may spread (peritonitis) may be painful or chronic may have no symptoms often leaves oviduct scarred so that fertility is reduced and the risk of ectopic pregnancy is increased treated with antibiotics most commonly caused by sexually transmitted bacteria the bacteria that cause gonorrhea and chlamydia 2.Cervical cancer: involves external surface of cervix detect with PAP test risk factors -intercourse at an early age -multiple sex partners associated with certain STDsparticularly the HPV (human papilloma virus) that causes genital warts use of condoms and/or diaphragm decreases risk Vagina ~3 muscular passageway to uterus elastic – expands to allow baby through possible problem with vagina: vaginitis most commonly yeast (Candida albicans) not usually sexually transmitted not from poor hygiene bacteria in the vagina produce acid Anything that kills the bacteria or makes the vagina less acidic allows yeast to grow ? vaginitis Clitoris †¢ †¢ †¢ Derived from same embryological structure as the glans penis Becomes engorged with blood during sexual excitement No known function other than pleasure 8Menstrual or Uterine Cycle the endometrium (uterine lining) is built up to nourish the embryo and then it breaks down and is lost as menstrual flow it is a cycle caused by interplay of hormones want the uterus ready to receive embryo if there is one the ovarian cycle that produces the egg must be coordinated with the uterine cycle that prepares the uterus done by same hormones Hormones of the menstrual cycle OVARY Estrogen – from follicle cells in ovary and later from corpus luteum maturation of egg cell division in endometrium (uterine lining) cell division in breast tissue Progesterone – from corpus luteum further development of endometrium maintains endometrium ANTERIOR PITUITARY FSH – follicle stimulating hormone: stimulate s development of follicle LH – luteinizing hormone formation of corpus luteum from follicle cells remaining in ovary maintains corpus luteum Negative Feedback X? Y hormone X leads to an increase in hormone Y Y? X hormone Y causes decrease in hormone X when hormone X levels fall, less hormone Y produced less hormone Y means less inhibition of hormone X hormone X increases and stimulates release of hormone Y IN GENERAL FSH & LH stimulate release of estrogen and progesterone estrogen and progesterone inhibit release of FSH & LH BUT rapid rise in estrogen triggers LH release LH causes corpus luteum to form and secrete estrogen and progesterone corpus lutuem degenerates – estrogen and progesterone levels drop (removes inhibition of FSH) 9Negative feedback in menstrual cycle Low levels of estrogen and progesterone stimulate the release of FSH (and LH) from anterior pituitary FSH stimulates estrogen release by follicle cells in ovary Estrogen (and progesterone) inhibit FSH (a nd LH) release FSH and LH levels drop Estrogen and progesterone levels drop if the egg is fertilized corpus luteum is maintained by a hormone from the embryo called: human chorionic gonadotropic (HCG) hormone for about 5 months the corpus luteum secretes progesterone placenta eventually takes over progesterone secretion progesterone is needed to maintain endometrium if progesterone secretion stops – there is a miscarriage Menopause considered to have occurred when there is no period for 1 year follicles in ovary spontaneously degenerate eggs no longer produced ends child-bearing years estrogen & progesterone no longer produced in ovary occurs most often between 4555yrs. occurs gradually Perimenopause = time leading up to menopause Symptoms hot flashes & dizziness – dilation of arteries in top half of body may be: irritable headaches fatigue physical changes skin drier & less elastic ? wrinkles breasts decrease in size might be change in distribution of hair osteoporosi s – decrease in bone density NEED NOT CHANGE SEXUAL DESIRE 10Estrogen DESIRABLE EFFECTS Brain regulates areas that prepare for reproduction maintains stable body temperature may protect memory Breast Breast programs glands promotes breast to produce milk cancer Liver & Heart helps regulate cholesterol production prevents atherosclerosi s Uterus Uterus programs uterus to promotes nourish fetus cancer of cell division in endometrium endometrium NEGATIVE EFFECTS Estrogen’s Effect on Bone Bone maintains density causes calcium to be absorbed from gut promotes calcium deposit in bones Osteoporosis – decrease in bone density calcium salts make bone hard bones are constantly remodeled built up & broken down in response to stress (weight or pressure) until age 35 more build up than break down peak bone density influenced by: sex race size nutrition exercise that puts weight on bones overall health Bone Formation Blood level Of calcium Calcium in Bone 11Bone Breakdown Die t influences level of calcium in blood good sources of calcium: milk and milk products (choose low fat) dark green vegetables nuts seeds Weight-bearing exercise stimulates bone formation in the bones that are stressed by the exercise walking jogging calcium levels are regulated by hormones calcitonin from thyroid gland causes calcium to be put into bones parathyroid hormone from parathyroid glands causes calcium to be removed from bone estrogen helps absorption of calcium from digestive system stimulates bone formation After menopause estrogen levels greatly decrease Bone Formation Calcitonin Estrogen Blood level Of calcium Calcium in BoneThe Breast Function To produce milk to nourish the young Structure The breast is composed almost entirely of fatty tissue and milk glands milk glands are called lobules each gland drains into a system of ducts these empty into a collecting chamber below nipple several ducts collect into one duct ducts drain through nipple Possible Problems 1. Preme nstrual tenderness breast tissue is prepared each month along with egg and endometrium Estrogen causes cell division in breast tissue Progesterone causes increase in glandular activity Increase in blood supply to breast swelling and tenderness Parathyroid Hormone Bone Breakdown Bone Formation 12 2. fibrocystic breast disease (disorder) an exaggeration of monthly changes in breast tissue built up tissue is not completely reabsorbed and forms cysts feels like many lumps in breast 3. fibroadenoma – noncancerous lump in breast usually in upper & outer quadrant small moveable lump 4. reast cancer will return to this after discussion of cancer 13 Cancer = uncontrolled cell division Cancer cells kill by: depriving other cells of nutrients preventing other cells from performing their duties blocking important pathways (air, blood, nerve) Cells divide Tumor Benign tumor: stays in one place; not cancer Malignant tumor: cancer, cells spread (metastasize) multiple tumors form in other pa rts of body usually spread via blood vessels or lymphatic system In healthy person cell division is regulated Cell Cycle = the orderly sequence of events in the life of a dividing cell G1 – cell growth (G1 checkpoint – is the cell large enough to divide? S (synthesis) – genetic material (DNA of chromosomes) is duplicated G2 – growth and final preparations for cell division (G2 checkpoint – is the DNA replicated? ) Cell division Mitosis – nucleus divides Cytoplasm divides produces two daughter cells Normal controls on cell growth regulate cell division to allow growth and replacement 14 Cancer cells escape controls Normal controls: 1. Genes regulate the cell cycle GENE carries the instructions for making a protein PROTEIN has a job in the cell it might form (part of) a structure it might be regulatory = determine whether a certain cellular process will occur mutation = change in the gene’s information changes the instructions for the p rotein the new protein might not function or might function differently Normal Controls on Cell Division 1.Genes regulate the cell cycle proto-oncogene – normal form of a gene that produces specific proteins that stimulate the cell cycle for growth and repair acts like accelerator about 60 known if other controls were faulty it would enhance the growth of a tumor tumor-suppressor gene – normal form of a gene that produces specific proteins that slow the cell cycle proteins stop cell cycle at one of the checkpoints acts like brakes Normal Genetic Controls on Cell Division tumorprotosuppressor oncogene gene slows stimulates cell division mutations in these cell cycle genes can cause the cell to lose control over cell division Cancer oncogene = mutant protooncogene over stimulates cell division = stuck accelerator can help induce cancer dominant mutation – only need 1 of the 2 copies to be mutant mutant tumor-suppressor gene impairs ability to slow cell cycle = bro ken brakes enhances tumor formation recessive mutation – need mutation in both copies of the gene to have an effect 15 p53 a tumor-suppressor gene detects damaged DNA 2. rogrammed cell death occurs when genes are damaged cancer cells have mutation in other genes that prevent the damaged cells from being destroyed 3. limited life span cell can only divide 50-60 times telomeres – protective pieces on tips of chromosomes end of telomeres shaved off with each cell division telomerase = enzyme that makes telomeres not present in normal cells is present in most cancer cells 4. Need for blood supply controls prevent new blood supply to tissue unless it is damaged cancer cells produce growth factors to attract new blood vessels blood vessels needed to bring nutrients and remove waste also provides route for cancer cells to spread tops cell division initiates DNA repair if too much DNA damage —> p53 triggers programmed cell death Development of cancer need several mutati ons in same cell before cancer starts leukemia – may be as few as 3 mutations colon cancer – may need as many as 9 mutations EXAMPLE ONLY: Development of colon cancer 1. Loss of tumor-suppressor gene from chromosome 5 a polyp forms on colon wall a benign, precancerous tumor grows 2. Activation of oncogene from chromosome 12 a class II adenoma (benign) forms) 3. Loss of tumor-suppressor gene from chromosome 18 a class III adenoma (benign) grows 4. loss of tumor-suppressor gene from chromosome 17 a carcinoma (malignant tumor) forms 5. other changes ? cancer spreads to other tissues 16 5.Need for cell attachment normal cells must be anchored in place oncogenes produce proteins that break anchors but signal cell that it is anchored Immune System – The body’s defense system cells of the immune system roam the body looking for cells they don’t recognize as belonging cancer cells have changed and are not recognized as belonging if cells of the immune syst em encounter a cancer cell, they will be destroy it Factors that can cause cancer 1. carcinogens = chemicals that cause cancer cause mutations that lead to cancer many mutate p53 stimulate cell division (e. g. estrogen) inhibiting the immune system may be in environment, in food or drink, or inhaled at least 50 carcinogens some carcinogens are only carcinogenic after modification in the body 2. iruses consist of genetic information (usually DNA) inside a protein coat virus enters cell and uses host cell machinery to make new viruses viral DNA is inserted into host cell chromosome and is replicated with host cell DNA viral DNA is then a permanent part of host cell chromosome – it has transformed the cell into a cancer cell – all daughter cells will have the viral genes viruses have oncogenes that produce proteins that stimulate cell division viral protein produced may be hyperactive in stimulating cell division OR viral gene may direct human gene to produce too much of a protein that stimulates cell division result is a host cell that has been permanently changed by virus so that it contains an oncogene that stimulates cell division 3. radiation interacts with DNA and causes mutation ultraviolet (uv) radiation from sun causes skin cancer ionizing radiation natural sources (cosmic rays, radioactive materials in earth’s crust) medical sources (x-ray exams) 17 Risk Factors 1. revious breast or other form of cancer Breast Cancer most breast lumps are benign (not cancerous) fibrocystic breasts fibroadenoma death rate from breast cancer has been declining due to early detection practice monthly self exam breast cancer usually begins in the ducts (80%) or the glands begins as lump or tumor lump is usually in upper outer quadrant staged by size of lump and how far it has spread it can metastasize: break out of this site and spread to fatty tissue or other parts of body through lymphatic system or blood supply to determine whether cancer has spread they would look at sentinel nodes (first lymph nodes to which a tumor drains) 2. Gender females much more likely (men can get breast cancer) 3. Age chance of breast cancer goes up with age rises sharply after 40 4.Family history risk is 2X if: first-degree relative (mother, sister, daughter) with breast cancer risk is 5X if: 2 first-degree relatives with breast cancer may have inherited genes e. g. BRCA 1 or BRCA 2 these greatly increase chance of breast cancer BRCA 1 = a tumorsuppressor gene turns off another gene that blocks cell cycle 18 5. Hormone history prolonged, uninterrupted exposure to estrogen increases risk estrogen stimulates cell division in breast if too much estrogen some believe it can lead to cancer some types of breast tumors are stimulated to grow by estrogen more menstrual cycles = more exposure to estrogen risk increased by: a. early puberty – before 11 b. late menopause – after 55 c. not having children or delaying first pregnancy – after 30 What about other sources of estrogen? irth control pills – probably not hormone replacement after menopause – slight environmental sources – unknown certain pollutants mimic estrogen (pesticides, ingredients in plastics) electromagnetic fields can boost body’s production of estrogen 6. Obesity fat cells produce a substance that is converted to estrogen 7. Alcohol alcohol increases level of estrogen interferes with use of folate, which protects against tumor growth 19 Birth Control Effectiveness rate = # of couples out of every 100 using that means of contraception for 1 year who do NOT become pregnant Failure Rate = # of couples out of every 100 using that means of contraception for 1 year who DO become pregnant Typical Use = average person, use may be improper or inconsistent Vs.Perfect Use = proper and consistent use Effectiveness in Preventing STDs STDs spread by contact (direct contact is usually needed) Infected surface surface Uninfected Effectiv eness in Preventing Pregnancy Highly Effective 1. Sterilization (tubal ligation or vasectomy) prevent sperm from reaching egg 2. Hormonal Contraception A. Estrogen and progesterone – prevents egg development and ovulation 1. oral – the pill 2. vaginal ring – NuvaRing – woman inserts the ring so that it encircles the cervix worn 3 weeks, removed for the 4th 3. skin patch – OrthoEvra new patch once a week for 3 weeks 4th week no patch B. Progesterone-only contraception interferes with fertilization and implantation Types a. ral – mini pill (not used much in US) b. implants c. injections C. Emergency contraception – ? morning after pills? 1. Preven – estrogen and progesterone 2. Plan B – progesteroneonly first dose within 120 hours (5 days), second dose 12 hours later Decrease spread of STDs Certain means of contraception also prevent contact between body surfaces Condom – male or female Diaphragm or cervical cap (so me protection to woman) Increase spread of STDs Pill may increase woman’s risk of certain STDs Spermicides increase a woman’s risk of getting an STD from an infected partner; damages vaginal lining 20 3. IUD – interferes with fertilization and/or implantation; dislodges embryo 4.Diaphragm, cervical cap, FemCap, or Lea’s shield with spermicide – covers cervix and prevents sperm from reaching egg 5. Condom – prevents sperm from reaching egg 6. Vaginal sponge Moderately Effective 1. Spermicides – kill sperm Foams are best is used as only means of contraception May increase the risk of STD spread, particularly in women 2. Rhythm Method – abstinence on all days that could result in sperm meeting an egg Unreliable 1. Withdrawal (coitus interruptus) Does not work 1. Douching after intercourse 2. Intercourse standing up or in some other position 3. Intercourse during menstruation (during your period) 4. Intercourse while breastfeeding Reliable methods 1.Sterilization — permanent birth control Tubal ligation or vasectomy prevent the sperm from meeting the egg Should NOT be used if you or your partner may change your mind For male = vasectomy Close off vas deferens so sperm can’t leave the male’s body Sperm reabsorbed Still ejaculate Simple operation No effect on masculinity No effect on sex life or sex drive Risks: minimal Less than 1% of time tubes grow back together Occasionally a little bleeding in scrotum For women = tubal ligation = have tubes tied Close off oviducts (fallopian tubes) More difficult procedure than a vasectomy because must enter the abdominal cavity Does not cause menopause Will still menstruate No effect on sex drive 21 2. Hormonal Contraception A. Estrogen and progesterone – prevents egg development and ovulation 1. oral – the pill 2. aginal ring – NuvaRing – woman inserts the ring so that it encircles the cervix; worn 3 weeks, removed for the 4th 3. skin patch – OrthoEvra new patch once a week for 3 weeks; 4th week no patch expect same risks as pill, but know most about birth control pill Contain estrogen and progesterone Estrogen & progesterone inhibit FSH and LH Without FSH the egg doesn’t develop Without LH ovulation cannot occur Almost 100% effective – if used properly If you miss more than one day, use another form of birth control Side Effects Headaches Breast tenderness Weight gain Vaginal Infections are more common Serious Risks caused primarily by estrogen Circulatory System Problems rare but can be fatal A.Problems: (1) High blood pressure (2) Increased tendency to form blood clots (1) High blood pressure Increases with time on pill Increases with woman’s age STOP SMOKING – cigarette smoking also causes high blood pressure Blood pressure = pressure exerted by blood on vessel walls Created by beating of heart Pressure must be great enough to move blood around the body If too g reat = high blood pressure Problems caused by high blood pressure 1. strains the heart and blood vessels 2. can lead to an aneurysm (weak spot in artery wall balloons out; can rupture; bleed to death internally 3. promotes atherosclerosis (fatty deposits in arteries) and arteriosclerosis (hardening of arteries) 4. amages kidneys; can lead to kidney failure 22 (2) Increased tendency to form blood clots Danger is that a blood clot can break free and lodge in a small blood vessel, blocking blood flow B. Consequences: (1) Increased risk of heart attack and stroke Heart attack = death of heart cells Stroke = death of nerve cells in brain Heart attack & stroke occur when blood flow to heart or brain is interrupted by: Burst vessel Fatty deposits (atherosclerosis) Blood clot (2) increased risk of pulmonary embolism 2. Increased risk of urinary tract infections 3. Increased susceptibility to sexually transmitted diseases A. Change in pH of vagina – increased risk of chlamydia and gon orrhea B.Change in cervical structure exposes vulnerable cells C. HPV (human papilloma virus that causes genital warts) infection is more likely to result in cervical cancer Progesterone seems to activate HPV in cervical cells grown is culture Non-contraceptive benefits of the pill Decreased risk of PID (pelvic inflammatory disease) Decreased risk of ovarian and endometrial cancer Decreased risk of ectopic pregnancy Decreased risk of iron deficiency anemia 1. 2. 3. 4. 2. Hormonal contraception (cont. ) B. Progesterone-only contraception interferes with fertilization and implantation Types a. oral – mini pill (not used much in US) b. implants –hormone containing rods implanted in upper arm c. njections – DepoProvera injection every 3 months 99% effective in preventing pregnancy no protection against STDs 23 Mechanism of action of progesterone only a. Thickens cervical mucus b. Interferes with movement of sperm c. makes implantation more difficult because endometr ium thin d. Sometimes blocks ovulation e. Makes the corpus luteum degenerate too quickly (removes the source of progesterone that maintains the endometrium) Side effects a. Menstrual cycle disturbance Periods irregular More days of light bleeding Missed periods b. Weight gain c. breast tenderness d. bone density decreases 2. Hormonal contraception (cont. ) C. Emergency contraception – â€Å"morning after pills† 1. Preven – estrogen and progesterone 2.Plan B – progesteroneonly first dose within 72 hours, second dose 12 hours later Emergency contraception is thought to work by inhibiting or delaying ovulation preventing fertilization altering the endometrium, making it an inhospitable place for implantation of the young embryo used after an act of unprotected intercourse if pregnancy not desired risk of pregnancy varies from 0 – 26 after a single act of intercourse – depending on day of cycle morning after pill decreases the risk of pregnancy by 75% (e. g. from 26% to 6. 5%) does not affect the embryo is it has already implanted Side effects: 1. nausea in 50-70% of women 22% vomit 2. menstrual cycle disturbance next period 2 – 3 days early or late 3.IUD (intrauterine device) – interferes with fertilization and/or implantation; dislodges embryo Small device placed inside the uterus by physician remains effective for 1, 3 or 7 years, depending on the type 24 Effectiveness 97% with progesterone 99% with copper Mechanism of action of IUD– affects: Sperm – immobilizes sperm; interferes with their movement Ovum – speeds up movement to uterus Fertilization inhibited Endometrium – not properly developed for implantation FemCap – 3 sizes, latex free, removal strap Prevents the sperm from reaching the egg Must use with spermicidal cream or jelly Helps seal gaps Holds it in place Added chemical protection Must be fitted by a health care professional so seal is tight refit if weight c hanges by more than 10 lbs. Effectiveness 97-98% perfect use 81% typical use It is ? at the time? rotection In place not more than 2 – 3 hr before intercourse Left in place at least 6 – 8 hrs. after intercourse Offers the woman some protection against STDs Risks with diaphragm – minimal 1. slight increase frequency of bladder infection 2. possible allergic reaction 3. toxic shock syndrome don’t leave in place more than 24 hours or use when you have your period 1. 2. 3. 4. Disadvantages 1. if never had children, insertion is painful 2. may have heavier menstrual flow & more cramps 3. body may reject it – then not protected against pregnancy Risks 1. pelvic inflammatory disease – primarily following insertion of the device can lead to sterility and increased risk of ectopic pregnancy 2. increased risk of ectopic pregnancy 4.Diaphragm or cervical cap with spermicide – covers cervix and prevents sperm from reaching egg Soft rubber cup on flexible ring that fits over the cervix Lea’s shield one-size fits all reusable device 25 5. Condom – prevents sperm from reaching egg A. Male condom Thin strong latex sheath that covers the penis and prevents sperm from reaching the egg Disadvantages: Must be placed on an erect penis – before contact with vagina Decreased sensation Failures usually due to tearing if pulled on too tightly – leave at tip if too little lubrication Penis should be withdrawn from vagina while still erect B. female condom Pouch of polyurethane with a flexible ring at each end Effectiveness in preventing pregnancy — 74% typical use Effectiveness against STDs Little known Does provide a barrier Male condom still better 6.Vaginal sponge use: put in place before intercourse (moisten first) leave in place for at least 6 hours after intercourse effective for 24 hours works by: 1. creating a barrier to sperm 2. trapping sperm in sponge 3. spermicide to kill sperm effectivenes s: about 83% less if you have had children Moderately Effective 1. Spermicides – kill sperm Foams are best is used as only means of contraception Effectiveness in preventing pregnancy – about 80% for 60 min. Increases a woman’s risk of getting an STD from an infected partner; damages vaginal lining 26 2. Rhythm Method – abstinence on all days that could result in sperm meeting an egg Egg Can be fertilized for about24 hr. after ovulation Ovulation ccurs 14+/days before the onset of flow Sperm Can live for at least 2 days within woman’s body Problem is predicting ovulation 2 days before it occurs Effectiveness about 75% Fertile period Subtract 14 days from cycle length Add 2 days on either side for uncertainty in time of ovulation Earliest fertile day = 2 days before earliest expected day of ovulation Latest fertile day = 1 day after the latest expected day of ovulation Works best if you avoid all days until at least 1 day after you know ovulation ha s occurred Ways of detecting ovulation 1. Body temperature Requires a special thermometer Must be done first thing in the morning When body temperature increases slightly and stays up ovulation has probably occurred 2. cervical mucus cervical secretion is more slippery and thinner at ovulation Unreliable 1. Withdrawal before ejaculation (coitus interruptus) Methods that DON’T work 1. Douching after intercourse 2. Intercourse standing up or in some other position 3. Intercourse during menstruation (during your period) 4. Intercourse while breastfeeding 27Sexually Transmitted Disease (STD) and Sexually Transmitted Infection (STI) Extremely Common 2/3 of cases in people under age 25 More likely to affect women Women exposed greater surface area of mucous membrane during sexual contact Women less likely to know they are infected Infected area not easily seen Urethra less likely to be infected So less like to be pain Therefore, women more like to have serious consequences. Spread by contact (direct contact is usually needed) Infected ? Uninfected surface surface Mucous membranes are most vulnerable linings of: Urethra Vagina, uterus, fallopian tubes Vulva (external genitalia of woman) Mouth and throat Rectum Eyes Many STDs can enter through break in skinBacteria A bacterium is a single cell A bacterium can divide very rapidly producing two daughter cells results in very rapid (exponantial) growth of the population *Bacteria produce harmful chemicals = toxins (poisons) of enzymes these toxins kills or damage body cells the damage to body cells causes the symptoms of the disease Bacteria ? Toxin or Enzyme ? Damages / Kills Body Cells Bacteria divide rapidly ? More Cells? More Toxin (or enzyme) ? More damage to body. * Sometimes the damage or symptom is caused by the body's defense mechanisms against the disease. Bacteria = cells with a slightly different structure than the cells found in your body Bacteria have a cell structures (called ribosomes) that have a sliightly different structure than human version Structural differences are important because they allow antibiotics to bactieria without killing host (your) cells. 28Antibiotics kill bacteria by: preventing bacteria from making cell walls OR preventing bacteria from making complete proteins OR damaging the plasma membrane Bacteria can become resistant to antibiotics by: inactivating the antibiotic pumping the antibiotic out of cell devoloping the ability to function in spite of antibiotics Antibiotic – resistant bacteria are a major health threat Antibiotic Resistance Some bacteria are now resistant to every known antibiotic Bacteria get their resistance from genes that: Inactivate the antibiotic Pump the antibiotic out of the cell Allow them to function in spite of antibiotic How do bacteria get these resistance genes? 1. They can get their own genes through mutation and selection a. mutation rate is high because rate of cell division is high hen antibiotics are used that a re not strong enough or are not used long enough, the most resistant survive each time antibiotic taken improperly, the more resistant bacteria survive resistance builds b. the â€Å"good bacteria? are killed by the antibiotic† the resistant bacteria can reproduce faster than normal, healthful bacteria and cause illness 2. Bacteria can get resistance genes from other bacteria through plasmids that carry genes for resistance Plasmids – a small circular piece of DNA (genetic materal) that contains a few genes not necessary for bacteria to live, but bacteria with them often have an advantage can be inserted into bacterial chromosome and come out as circular piece again Plasmids can be copied and a copy gived to another bacterium through sex then both bacteria have the genes on the plasmid. 29Certain plasmids (called R factors) have genes for resistance to antibiotics possible to have genes for 1 or 10 different antibiotics genes for resistance for one antibiotic can be ad ded to a plasmid than has genes for resistance to other antibiotics leads to the development of bacteria that are resistance to many different antibiotics multi-drug resistance tends to happen in places where antibiotic use is heavy hospitals farm animals Resistance develops where antibiotics used most Hospitals Livestock Overuse and Misuse of antibiotics has led to resistance 1. Misuse for medical purposes Don't demand antibiotics for viral diseases – they don't work on viruses Take the full course of your prescription 2.Widespead use in livestock and agriculture Used in livestock to promote growth Resistance genes can spread from the animals to the bacteria that harm humans Cook meat throroughly (be sure meat juices don't come in contact with other food) Wash fruits and vegetables Avoid raw eggs Chlamydia and Gonorrhea Caused by different bacteria but have similar symptoms Both primarily affect mucous membranes Most noticeable symptom – if it occurs – is pain during urination This occurs if urethra is infected Urethra is more likely to infected in a male Therefore males more likely to have symptoms Often they don't cause symptoms Can still spread the cactiria to others Bacteria still damage reproductive structures 30Chlamydia (Chlamydia trachomatis) Most common bacterial STD in US Highly contagious Symptoms – slow to appear, 3 weeks to months Men More likely to have symptoms than women Painful urination Discharge from urethra Women If urethra is infected Painful urination Discharge from urethra PID (chlamydia causes 50-90% of PID) Slight vaginal discharge Pain during intercourse Abdominal pain & fever Chlamydia is the STD the most likely to cause scar tissue to form in the tubes that gametes move through Because of scar tissue: Chlamydia is the STD most likely to cause sterility Chlamydia is the STD most likely to increase the risk of an ectopic pregnancy The bacteria that cause chlamydia Must live within a cell because they canno t generate their own ATP They use the ATP that the host cell produces Energy in food ATP Energy for cell activities Effects on Fetus in Utero can cause membranes to rupture can cause death of fetus contracted during birth blindness pneumonia infection of mouth, throat, rectum Diagnosis Urine test for DNA for Chalmydia Swab cervix (women) or urethra (males) and culture cells Pap test (women) Treatment: Antibiotics Gonorrhea Caused by diplococcus bacterium Neisseria gonorrheae Symptoms Often none Men More likely to have symptoms than women Painful urination Discharge from urethra 31Women If urethra is infected Painful urination Discharge from urethra PID Slight vaginal discharge Pain during intercourse Abdominal pain & fever Acidity decreases if on pill or at menopause Effect on fetus: Contracted during birth May cause blindness Diagnosis: Urine test form DNA Swab cervix (women) or urethra (males) and culture cells Look for bacteria in cells Treatment: Antibiotics New varieties are re sistant to antibiotics Syphilis Cause = bacterium (Treponema pallidum) Requires a warm, moist environment Can invade any mucous membrane Usually in the genital area Three Stages 1. Primary Stage 2-6 weeks after contact chancre forms may be small swelling or deep lesion usually hard raised edges â€Å"crater-like† painless at site of contact heals by itself in 4-6 weeks diagnosis at this pint is by isolation of the bacterium from chancre 2.Secondary Stage 2-10 weeks after chancre appears Symptoms Rash- doesn't itch, ulcerates Ulcers in mucous membranes In mouth, vulva, vagina, rectum Warly growths around anus and genital organs Headache Body ache May have: Sore throat Gastrointestinal upset Loss of hair Diagnosis at this stage: Blood test that looks for antibodies (VDRL) 32 3. Tertiary Stage 8-25 years after initial contact almost any organ can be infected and develop lesions called a gumma most common sites of gummas: 1. large arteries decrease diameter of artery aneurysm â⠂¬â€œ weak spot in artery that balloons out 2. brain & spinal cord Blindness Deafness Paralysis Mental degeneration 3.Skeleton Effect of fetus Transferred across placenta Can cause deformities Can be fatal Treatment: Early stages curables with antibiotics Virus Viruses have genetic material (usually DNA but some have RNA) and a protein coat (capsid) Structure of a typical virus Steps in Viral Life Cycle 1. Attachement – Viral protein binds to receptor on host cell 2. Penetration – virus enters host cell 3. Biosynthesis – viral genetic material replicated by using host cell ? machinery;? new coat proteins made 4. Assembly – newly synthesized viral compnents put together to form new viruses 5. Release [called viral shedding or budding]; viruses leave cell with envelopes from host cell OR Viruses genetic information can be integrated into host cell chromosome and stay there in dormant form until it is reactivated Viruses can cause call damage as they are rel eased (shed) 1.Rapid release – cell can rupture and die 2. slow release – cell damage and dearth occurs over long time period 3. Periodic release – viruses can remain in certain body cells (e. g. nerve cells) for life; they may be release from body cells periodically and enter new target cells. (herpes can remain in nerve cells; be released epriodically and enter new epithelial cells; damages the epithelial cells) 4. be integrated into host chromosome and stay there in dormant form until it is reactivated 33 Lytic Infection Persistent Infection Latent Infection Transformation to cancerous cell Rapid release of new viruses from infecded cell caused cell death.The symptoms of the disease depend on which cells are killed Slow release of new viruses causes cell to remain alive and continue to produce new viruses for a prolonged period of time. Delay between infection and symptoms. Virus is present in the cell without harming the cell. Symptoms beging when the virus begins actively replication and causes cell death when new viruses exit the cell. Certain viruses insert their genetic information into host cell chromosomes. Some carry oncogenes (cancer – causing genes) that are active in the host cell. Some disrupt the functioning of the host cell's genes that regulate cell division, causing the cell to become cancerous. Viruses and Disease 1.Can cause cell damage as they leave the host cell; the cell damage causes the symptoms 2. Can cause cancer when they insert themselves into host chromosome or by producing factors that affect the host genes that regulate cell division Genital Herpes Cause virus Herpes simplex -type 1 (HSV-1) – usually associated with fever blisters + cold sores -type 2 (HSV-2) – usually causes similar sores in genital area Symptoms (if there are symptoms) first may have a tingling or itching sensation (called the prodrome) 2-20 days after contact blisters of fluid filled sores 1st attack lasts about 3 wk s (1wk-4wks) can use ointments to relieve the pain will go away whether treated or not Also cause cancer hen they insert themselves into host chromosome o r by producing factors that affect the host genes that regulate cell division Viruses and Disease 34 Genital Warts in about half (50%) of people with herpes: blisters reform periodically usually at times of stress because the virus moves the the sacral ganglia of the spinal cord not affected by the human immune system here can be reawakened + cause new sores -maybe 2x month or 1x in 10yrs -NO CURE Genital Herpes spread by contact of infected and uinfected surface no sex while blister present or during prodrome or for at least 10 days after blisters are gone use a condom at all timeseven when no blisters are present erpes can be spread to newborn if deliver vaginally while virus is present if infant's infection is in liver and central nervous system-can be fatal Diagnosis Examination of sores Culture fluid from sores Blood test for antibodies in women-Pap test Treatment -Syptoms only Acyclovir (Zovirax):-reduce severity of first outbreak and reduce frequency of recurrences Human Papilloma Virus (HPV) usually transmitted by sexual contact 50-70% of those who have sex with an infected person will get them more likely if on the pill or pregnant or uncircumsized appear 1-2 months after contact, maybe longer appearance of growth on dry areas- brownish on moist areas-pink they grow may cause foul-smelling discharge may itch -warts can be removed by: 1. freezing 2. burning 3. laser 4. treated with a chemical (podophyllin) that is painted onleft 4 hrs. washed away warts fall off * virus may remain Diagnosis appearance of wart in women-Pap test can look for DNA of HPV inside cells 35 Genital Warts *ASSOCIATED WITH INCREASED RISK OF CERVICAL CANCER -HPV found in 90% of women with cervical cancer There is now a vaccine against HPV and, therefore, against cervical cancer *ASSOCIATED WITH AND INCREASED RISK OF CANCER OF P ENIS 36 BODY DEFENSES Innate Responses – Nonspecific Physical and Chemical Barriers Adaptive defense: Specific defenses (directed at specific target): The immune system: 1. Specific for particular â€Å"invader† (antigen) 2. Has memory for specific antigens previously encountered Lymphocyte encounters antigen Immune responses have 1.Specificity: Specific for particular â€Å"invader† (antigen) Antigen = a large molecule (not recognized as belonging in the body) that triggers an immune response Ex: antigen can be on the surface of a bacterium or virus etc. ; can be a bacterial toxin Your body cells have markers (molecules) that label them as belonging in your body Each lymphocyte has receptors on its surface that recognize a specific antigen When that antigen is present, it causes that lymphocyte to divide many times Effector cells Memory cells Effector cells attack specific target Memory cells remain and provide a quick response in subsequent exposure to same an tigen Third line of defense: Specific defenses (directed at specific target): The immune system: Immune system is 1. specific for a particular ? invader? antigen) 2. has memory for specific antigen previously encountered Creates an army of lymphocytes specialized to attack that antigen These are called Effector cells 2. Memory: have memory for specific antigen previously encountered Memory lymphocytes remain to cause a quick response the next time the same antigen is encountered 37 STEPS IN IMMUNE RESPONSE 1. Threat: foreign cell or molecule enters body 2. Detection Macrophage: detects invader engulfs invader digests invader 3. Alert: Macrophage places a piece of consumed antigen on its plasma membrane attached to a self marker presents the antigen to a helper T cell activates the helper T cell 4.Alarm: Helper T Cell: after activation by a macrophage, it divides, forming effector helper T cells and memory helper T cells turns â€Å"on† both lines of immune response to fight t hat specific antigen by activating B cells and T cells 5. Build specific defense (clonal selection) Lymphocyte encounters antigen Effector cells attack specific target Memory cells remain and provide a quick response in subsequent exposure to same antigen 6. Defense A. Antibody-mediated immune response Effector B cell = Plasma cell Plasma cells secrete antibodies Targets = antigens outside of cell or on surface of cell B. Cell-mediated immune response Effector T cell = cytotoxic T cell Cytotoxic T cells kill foreign cells by causing them to burst Targets = cells bearing antigens (any cells recognized as foreign: e. g. nfected cell, bacteria, cancer cell) 7. Continued surveillance memory cells remain 8. Withdrawal of forces After antigen has been destroyed suppressor T cells shut down the immune response Effector cells cells Memory 38 A. Antibody-mediated immune response Effector B cell = Plasma cell Plasma cells secrete antibodies Targets = antigens outside of cell or on surface of cell An antibody is a Y-shaped protein designed to recognize a specific antigen Antibodies help defend against a specific antigen Can only work against antigens that are free in blood Antibodies bind to the antigen Antibodies are secreted by plasma cells (effector B cells) Ways that Antibodies can Work 1.Neutralization – bind to antigen prevent virus from being able to enter host cell inactivate toxin 2. Agglutination and precipitation -clumps â€Å"invaders† together makes it easier for other cells to engulf them 3. Activation of complement system complement (system) is a group of proteins that pokes holes causes â€Å"invader† to burst B. Cell-mediated immune response Effector T cell = cytotoxic T cell Cytotoxic T cells kill foreign cells by causing them to burst Targets = cells bearing antigens (any cells recognized as foreign: e. g. infected cell, bacteria, cancer cell) Cytotoxic T cells secrete proteins called perforins that poke holes in â€Å"invaderâ₠¬  or foreign cells, causing them to burst 39Cells Involved In the Immune System Macrophage: an antigen presenting cells engulfs and digests antigens places a piece of consumed antigen on its plasma membrane presents the antigen to a helper T cell activates the helper T cell B Cells: T Cells: Helper T Cell: the â€Å"on† switch for both lines of immune response after activation by a macrophage, it divides, forming effector helper T cells and memory helper T cells activate B cells and T cells Cytotoxic T cell: (effector T cell) responsible for cellmediated immune responses when activated by helper T cell, it divides to form effector cytotoxic T cells and memory cytotoxic T cells destroys cellular targets, such as virusinfected body cells, bacteria, fungi, arasites, and cancer cells Suppressor T cell: the â€Å"off† switch for immune responses suppresses the activity of B cells and T cells after the foreign cell or molecule has been successfully destroyed involved in an tibodymediated responses when activated by helper T cells, it divides to form plasma cells and memory cells Plasma Cell: effector in antibodymediated response secretes antibodies specific to the invader Memory Cells: responsible for memory of immune system generated by B cells or any type of T cell during an immune response enable quick and efficient response on subsequent exposures of the antigen may live for years 40 AIDS Acquired Immune Deficiency Syndrome Caused by HIV Human Immunodeficiency Virus HIV infects T cells T cells become HIV factories Organism enters body Macrophage detects it HIV kills helper T cells so THIS doesn’t happen Activates a helper T cell Stimulates division of cytotoxic T cells (attack foreign cells) As helper T cell numbers drop, the body becomes increasingly susceptible to infection Stimulates B cells to form antibodies (destroys the infectious organism) 41

OFDM Simulation In Matlab Computer Science Essay

Abstract-This undertaking involves the simulation and survey of a simple Orthogonal Frequency Division Multiplexing ( OFDM ) system as an application of Digital Signal Processing. The country of focal point is the signal processing block of the system which uses Fast Fourier Transform ( FFT ) engines to accomplish perpendicularity of channels and thereby better the transmittal channel use. The system is simulated utilizing MATLAB and it involves transmittal of a digitized sound file through an linear white Gaussian noise ( AWGN ) channel utilizing OFDM technique and so retrieving the file at the receiving system. By correlating the original and the recovered file the effectivity of this technique is tested. The whole system realisation consists of multiple stairss – beginning processing, channel, receiving system processing, analysis. Keywords-OFDM ; AWGN ; FFT ; IFFT ; BPSK ; Orthogonality ; CrosscorrelationI. IntroductionOrthogonal frequence division multiplexing ( OFDM ) is a frequence division multiplexing strategy in which the frequence separation between next bearer channels is minimized by the usage of the construct of perpendicularity. It is one of the multiple entree techniques widely used in radio and powerline communications. OFDM can supply big informations rates with sufficient hardiness against transmittal channel damages. The OFDM strategy allows several extraneous, narrow band sub-channels or subcarriers to overlap in frequence sphere and to be transmitted in parallel thereby spliting the available transmittal bandwidth expeditiously. The input informations is divided into several parallel informations watercourses or channels, one for each subcarrier. Each sub-carrier is modulated with a conventional digital transition strategy ( such as M-ary stage displacement identifying or Quadrature amplitude transition ) at a low symbol rate so as to keep the entire information rate similar to conventional single-carrier transition strategies utilizing the same bandwidth. The perpendicularity is achieved utilizing the fast Fourier transform ( FFT ) algorithm on the receiver side, and reverse FFT on the sender side as it allows for efficient modulator and detector execution. A general OFDM system diagram is shown in Fig. 1. At the sender, the modulated information signal ten [ n ] is foremost transformed to frequence sphere through IFFT. Then the signal is transmitted to the finish in the radio channel. At the receiving system, FFT is foremost applied to the standard signal, so the transmitted information symbol is estimated with some decrypting algorithm. The processing at each block with the assistance of MATLAB is described briefly as follows:A.Source ProcessingAt the beginning, the sound file is first read utilizing MATLAB as a vector music and converted into a binary information watercourse. Binary stage displacement keying ( BPSK ) is used as the transition strategy. In BPSK, each binary informations 1 is mapped to an information symbol of 1, while 0 is mapped to a?’1. With BPSK transition, we can obtain the information vector. Then a 512-point IFFT is performed on that vector to bring forth the vector Texas for transmittal. Zero-padding is used if the information is non a multiple of 512.B. ChannelThe channel is simple AWGN, which means that there is no channel attenuation and the noise is Gaussian distributed with zero mean and discrepancy I?2. For a random noise, the standard signal is transmitted signal ( Texas ) +noise.C. Receiver ProcessingAt the receiving system, FFT is performed on the received informations obtain the noisy informations for decrypting. Simple bit-wise maximal likeliness ( ML ) decryption is adopted. Therefore, for each received noisy information spot, if the value is larger than 0, it is decoded as 1, otherwise, 0.D. System AnalysisThe received informations will the compared with the transmitted informations utilizing crosscorrelation to analyze the difference. The execution will be repeated for different values of noise discrepancies. In the subdivisions that follow we discuss in a bit-by-bit manner how we can implement such a system by sing all the indispensable resources. In subdivision II, the development of the full system is described along with relevant theoretical background. Section III shows how the system can be simulated utilizing MATLAB tools. Section IV contains the consequences of simulation and analysis of the system. Section V concludes the paper by supplying an abstract of the work done.II. system theoretical accountThe system is simulated utilizing MATLAB. The flow diagram of the system operations is shown in Fig. 2. Fig. 2 OFDM system theoretical account [ 8 ]A. TransmitterThe sender subdivision includes reading the sound file, change overing it into a binary watercourse, usage BPSK to modulate this watercourse and so execute N-point IFFT on the modulated informations to change over the information watercourse into N extraneous OFDM channels. In BPSK, each binary informations 1 is mapped to an information symbol of 1, while 0 is mapped to a?’1. Thus we get a consecutive watercourse of BPSK modulated informations. The watercourse is divided into N analogue informations which forms the footing of an OFDM symbol.1. FFT-IFFT Algoritms and OrthogonalityAn OFDM system treats the input BPSK modulated symbols at the sender as though they are in the frequency-domain. These symbols are converted into parallel and are used as the inputs to an IFFT block that converts the signal into the clip sphere. The IFFT takes in N symbols at a clip where N is the figure of subcarriers/channels in the system. By definition of Inverse Discrete Fourier Transform ( DFT ) : x_n = frac { 1 } { N } sum_ { k=0 } ^ { N-1 } X_k e^ { frac { 2pi I } { N } K n } quad quad n = 0, dots, N-1. The signals eiˆ?i? °ikn/N are extraneous over ( 0, N ) where Xk is the input symbol. DFT is the Fourier Transform of distinct clip signal taken at distinct blink of an eyes 2i? °k/N. FFT/IFFT is a computationally efficient version of DFT/IDFT. For case, for N point DFT the computational complexness is N2 whereas for radix-2 FFT the 1 clip calculation is broken down into log2N degrees and each degree need N calculations hence the complexness is reduced to Nlog2N degrees. Therefore cut downing the calculation clip in instance of FFT. Therefore from above definition the base maps IFFT are N extraneous sinusoids, in other words IFFT is expressed as the leaden amount of extraneous sinusoids. These sinusoids have a different frequence extraneous to each other in frequence sphere. Each input symbol Acts of the Apostless like a complex/real weight for the corresponding sinusoidal term. Input symbols will be complex if M-ary PSK is used where M & gt ; 2. In such instance the value of the symbol determines both the amplitude and stage of the sinusoid for that subcarrier. However, since BPSK is used the weights are existent. The IFFT end product is the summing up of the N weighted sinusoids. Therefore, IFFT provides a simple manner to modulate informations onto N extraneous closely separated subcarriers. The block of N end product samples from the IFFT make up a individual OFDM symbol. hypertext transfer protocol: //www.wirelesscommunication.nl/reference/chaptr05/ofdm/images/fig4.gif ( a ) ( B ) Fig 3: OFDM spectrum ( a ) Single channel ( B ) 5 subcarriers [ 6 ] The signals e2i? °kn/N are extraneous over ( 0, N ) as sum_ { n=0 } ^ { N-1 } left ( e^ { frac { 2pi I } { N } kn } ight ) left ( e^ { -frac { 2pi I } { N } k'n } ight ) =N~delta_ { kk ‘ } This perpendicularity due to FFT among next channels implies closely spaced bearers. They can be spaced in such a manner such that the nothing ( zero amplitude response ) of one channel will happen at the extremum of the next bearer as shown in Fig. 3. Therefore merely half of the available transmittal bandwidth will be utilised comparison to standard FDM, bettering the channel use by 50 per centum. The distinct time-domain signal that consequences from the IFFT is transmitted across the channel. Actual transmittals involve transition of IFFT bins into baseband parallel bearers before transmittal over the channel. But for simpleness of analysis we transmit the digital baseband signal itself as N subcarriers in a multipath free environment. Orthogonality of the subcarriers due to IFFT allows the frequence spacing between each next subcarrier to be minimal.B. ChannelThe channel is assumed to be simple AWGN, which means that there is no channel attenuation and the noise is Gaussian dist ributed with zero mean and discrepancy I? . The familial consecutive watercourse of IFFT bins is added to the random AWGN noise generated utilizing MATLAB to enforce the effects of channel.C. ReceiverAt the receiving system, an N point FFT block is used to treat the standard signal and convey it back into the frequence sphere. By definition of Discrete Fourier Transform ( DFT ) : Due to grounds mentioned antecedently FFT is the used in topographic point of DFT. The N point FFT end product will be the original symbols that were sent to the IFFT block at the sender. The end product of the FFT block is capable to maximum likelihood sensing to pull out the binary information from the noise infested symbols. After recovery of binary informations, it is converted to its parallel tantamount thereby retracing the original sound file.III. matlab simulationA. Transmitter1.Input audio file processingThe samples of the sound file that has to be transmitted is read into a vector Y utilizing the wavread bid. The wavread bid besides outputs two statements viz. the sampling frequence and spots per sample which are stored in variables degree Fahrenheits and spots severally. The scope and amplitude of the samples obtained are really little and hence they are increased by factor of 2 ( bits-1 ) and shifted by 2 ( bits-1 ) to acquire positive samples and thereby execute quantisa tion and change over it into 16-bit binary informations utilizing the dec2bin bid. 2. BPSK transition The binary informations stored in a array is BPSK modulated utilizing the simple algorithm of mapping each binary informations 1 to an information symbol of 1, and 0 to a?’1 utilizing a for cringle. Figure 3 shows the configuration for BPSK ( 1bit/symbol ) . Figure 4: BPSK configuration3. IFFTThe BPSK modulated informations which is stored in a martix is converted into a row vector utilizing reshape bid in order to execute 512 point IFFT which is in consequence change overing the consecutive watercourse into 512 point parallel watercourse. IFFT is performed utilizing the bid ifft. The consequence of IFFT of the modulated information is an 512 point OFDM symbol. Since IFFT in MATLAB is calculated utilizing the definition of IDFT we need to multiply the IFFT vector by sqrt ( N ) to raise the mean power degree in order to keep sufficient signal to resound power ratio in the channel. After IFFT the parallel information is converted to consecutive and stored in vector txdataN.B. ChannelChannel is simulated by adding noise by bring forthing random white noise ( Gaussian distributed with average 0 and discrepancy as we specify ) utilizing the bid randn. The white noise generated utilizing randn is added it to txdataN. Thus, ch=txdataN+noise whe re noise= I?*randn ( 1, length ( txdataN ) ) .C. Receiver1.FFTThe standard OFDM signal vector ch is coverted into parallel and 512 point FFT is performed utilizing the bid fft to retrieve the noisy BPSK modulated informations. The scatterplot of the noise infested received informations is shown in Fig. 5 Fig. 5: Received Configuration with noise2.Maximum Likelihood ( ML ) DetectionIf the end product of FFT is observed to be complex, merely the existent portion is taken to observe the information symbols. Simple bit-wise maximal likeliness ( ML ) decryption is used to retrieve the original binary informations. Thus, for each received noisy information spot, if the value is larger than 0, it is decoded as 1, otherwise, 0.3. Reconstruction of audio file from recovered informationsThe cured digital information is converted into tantamount parallel samples utilizing bin2dec bid where each sample corresponds to 16 spots. The samples are so stored as a wav file recovered_music at a sampling frequence degree Fahrenheit utilizing the bid wavwrite.4. CorrelationThe cured sound file is played utilizing bid soundsc to observe the difference with the original file. The correlativity coefficient of the received sound vector and the original sound vector is calculated utilizing the bid corrcoef and stored in a matrix corr. As we change the discrepancy of the noise vector, which implies a alteration in the channel SNR, the covariance between the original and the recovered information lessenings and as a consequence we get a noisy sound at the end product.IV. System analysis and Simulation ResultsA. Frequency Analysis1.Frequency Response of input informations watercourse ( BPSK Modulated ) .2.OFDM channel frequence responseB. Input Sequence and matching OFDM symbolC. Correlation between input and end product informations1.Input sound samples. Fs=8kHz2.Recovered sound samples w/ correlativity coefficient=0.9042Discrepancy of AWGN=0.23.Recovered sound samples w/ correlativity coefficient=1Discrepancy of AWGN=0.013.Recovered sound samples w/ correlativity coefficient=0.1758Discrepancy of AWGN=1V. ConclusionOrthogonality in OFDM introduced due to the usage of DSP engines FFT and IFFT have proven to be really effectual in the improving channel spectral use by leting the convergence of next channels to about half of the channels bandwidth. Besides transition and demodulation complexness is reduced due to the usage FFT techniques. As a consequence it is executable to utilize ML decrypting to retrieve binary informations. In this undertaking, a simple MATLAB theoretical account of OFDM was simulated to analyze OFDM utilizing FFT. The power of FFT-IFFT to present orthogoniality in subcarriers was demonstrated. The consequence of AWGN channel utilizing different noise discrepancies was illustrated. The consequences showed that little noise discrepancies, that is, high signal to resound rations had negligible consequence of original informations. which was apparent from the computation of correlativity coefficient of original and cured informations.VI. MentionsE. Lawrey, â€Å" The suitableness of OFDM as a transition technique for wireless telecommunications, with a CDMA comparing, † B. Eng. thesis, James Cook University, Oct. 1997. Anibal Luis Intini, â€Å" OFDM for Wireless Netwoks † , University of California, Santa Barbara, CA. Rep.Dec.2000. G. Acosta, † OFDM simulation utilizing MATLAB † , Georgia Institute of Technology, GA. Rep.Aug. 2000. Alan C. Brrooks and Stephan J. Hoelzer, â€Å" Design and Implementation of OFDM Signalling † , Rep.May.2001. John G.Proakis, Digital Signal Processing, 3rd erectile dysfunction. Mathematical description of OFDM. [ Online ] .Available: hypertext transfer protocol: //www.wirelesscommunication.nl [ Revieved: 12/01/2010 ] ( Fig. 3 ) Matlab Tutorial. [ Online ] . Available: www.mathworks.com/academia/ EEL5525 Class Notes ( Fig. 1, 2 )

Intro to Astronmy Article Example | Topics and Well Written Essays - 1000 words - 1

Intro to Astronmy - Article Example In 200 AD, astronomers believed that planets moved round the earth in small circles called the epicycle. The Heliocentric model later explained that all planets including the sun revolved around the sun. This model also explained that the retrograde motion of planets did so as the earth which moves faster than the other planets overtook the other planets. Other planets are categorized as superior or inferior to the earth. Time that is able to elapse between the configurations that are identical and consecutive is known as the synodic period. It was Copernicus who determined the sidereal period of other planets. He was also able to know the distance between the planets and the sun. Kepler was able to come up with a law that stated that every planet has an orbit that about the sun know as an ellipse. He also came up with the semi major axis. This happens to be the distance between the planets and the sun. The measure of the deviation from the perfect circle is known as the eccentricity. Kepler had three laws to explain the motion of planets and this was a major achievement in the field of astronomy. Galileo was able to discover a lot more with the aid of a telescope. He was able to know that the earth was not at the centre of the universe. With his telescope, he was able to know that the earth was not at the centre of the universe and that the earth was just like any other planet moving around the sun. Isaac Newton later came and introduced three laws. Inertia, force and action and reaction. He was also able to come up wi th the laws of the universal gravitation. The law of gravitation states that two bodies attract each other with a force directly proportional to each and every mass of the two bodies. This force is also inversely proportional to the square of the distance between them. Using the law of gravitation, Kepler’s three laws can be summed up. Newton’s was able to note that every

Globalization Law Thesis Example | Topics and Well Written Essays - 500 words

Globalization Law - Thesis Example The researcher proposes to do a case study on the effect of globalization on the labor market in gulf area. Scope of Report Our topic of study is the impact of globalization on labor markets with focus on gulf area. The study would include all the countries in the gulf area including Saudi Arabia. Due to globalization there has been movement of material, labor and capital also. These movements have left a tremendous impact on the organizations across the globe. The study would however focus on the effect on labor markets specifically, and examine what kind of impact it has left on the labor market. The researcher would like to adopt a research design that uses both qualitative and quantitative information. Using both qualitative and quantitative design approaches will allow the researcher to use both primary and secondary sources of information. This will lead to a better understanding of the topic. The researcher intends to analyze the effect of globalization on the labor market esp ecially in the gulf area.How the companies are coping with the problem will be studied and analyzed. In doing so the author will use the principles of Miles and Snow’s theory of superior performing business types discussed in their 1978 book (Miles et al, 1978).

B2B and B2C Marketing Assignment Example | Topics and Well Written Essays - 1000 words

B2B and B2C Marketing - Assignment Example Thus, business buyer demand is derived demand. It means that there is an impact of all the determinants of individual demand on the derived demand of the business consumers. Moreover, it also means that it may be possible in the consumer market to mold the demand but it is rarely possible to mold the demand of business consumers. The demand in the business market is more inelastic than the consumer market. It means that the demand of the consumer market is not affected by short-run market price fluctuations. The business market contains fewer but larger customers but in the individual consumer market, the number of buyers is large but average quantity they purchase is small. Moreover, the business market is geographically more concentrated as compared to individual customers. The promotional techniques used in marketing for business are different from that for individual customers. For B2B marketing, usual techniques are direct sales, trade discounts, personal networking etc. However, for B2C marketing, the promotional techniques are advertising and other above the line (ATL) marketing techniques. Since the buying decision is very crucial and any error in that decision may cause a great loss, the buyers of the B2B are more rational, whereas, many consumer buying decision is derived by emotional appeals. The example we have chosen to demonstrate the difference between B2B and B2C is the automotive industry. The automotive industry may serve both the purposes, B2B and B2C. If an automotive industry is manufacturing cars to be sold to the individual consumers, it is B2C market operation, and however, if ACE Car Rental, a car rental service provider, purchases a car from the same vendor (Toyota Motor Corporation Australia). In that case, it would be the B2B market.  

Phonetics and you can find every thing in the slide Essay

Phonetics and you can find every thing in the slide - Essay Example 2a) Within the dataset provided there is only evidence of one minimal pair: [kano] â€Å"to make† and [xano] â€Å"to lose† providing evidence of /k/ and /x/ being phonemes because they are contrastive and therefore distinctive. It is unlikely that a language will have only one stop consonant (plosive) so it can be assumed that /t/ and /p/ are also phonemes. The fact that there is evidence of both a voiced /?/and voiceless /x/ velar fricative occurring in the same environments anticipates they are phonemes, and that a voiced counterpart to the labio-dental /f/ and alveolar fricative /s/ would also be found with further data. Evidence also suggests that although the voiced and voiceless pairs of velar fricative phonemes exist they are not found in all situations; for example, /x/ and /?/ occur directly before the back mid vowel /o/ and the low vowel /a/ but not before the high /i/ and mid /e/front vowels and are thus in complementary distribution, wherein we find a voice less alveolar fricative [?] or its voiced counterpart [?]. ... /n/ only occurs between vowels, but because of symmetry it is more likely they both occur as phonemes – within this same argument there may be a velar nasal /?/. Another allophone evidenced in the data is the alveolar trill [r] which is only found inter-vocalically preceding two vowels - in other words a diphthong. It can thus be assumed that the flap or tap /?/ becomes a trill [r] before a diphthong. The difficulty in terms of interpretation in this data set is whether the post alveolar affricate [t?] is a phoneme or an allophone; for want of further evidence and because both the voiced and voiceless post alveolar fricatives occur in the same environment as the post alveolar affricate it is suggested that it is an allophone of /k/ in keeping with the symmetrical pattern of each velar phoneme having allophones preceding front vowels. The only other phoneme not discussed within the list is the back high vowel /u/, which if considered a phoneme provides a five vowel system for C retan. 2b) The following rules would account for the presumed four allophones: /x/ [?] / -- /i/ and /e/ /?/ [?] / -- /i/ and /e/ /k/ [t?] / -- /i/ and /e/ /?/ [r]/ -- /i/ or /e/ 2c) Based on the dataset it is likely that [g] does not exist in Cretan because there is no evidence of any voiced stops; thus it can be assumed that Cretan only has voiceless stops. References Silzer, P.J. 2005, Working with Language: an interactive guide to understanding language and linguistics. SIL at Biola, Department of TESOL and Applied Linguistics, School of Intercultural Studies, Biola University, viewed 14 January, 201,

My Father's Life Essay Example | Topics and Well Written Essays - 750 words

My Father's Life - Essay Example His mother felt the need for change and so to upgrade him from their not so good financial background, sent him off to a school in San Francisco, where he was to put up with an aunt while attending a public school since she could not afford him the luxury of studying in a private school. The Second World War broke out while my father was still in school, and like most of his friends and all young strong and loyal men of the day, he was drafted into the army to fight for the cause of the nation he believed in. There, he drove an ambulance though his preference was to fight in the front line. He could penetrate war fields and employ skills and extraordinary tactic in missions to rescue injured solders, and once, he almost got himself killed when the ambulance he was driving was bombed by an enemy tanker missile while on a rescue mission to save the life of some seriously injured colleagues. His friends said that his cleverly wit survived him through the war. Immediately after the war, my father returned to Connecticut and decided to settle there. He later met my mother, a shy strong girl from Jamaica, with a large doze of innocent and a tremendous appetite. My father always said that he fell for her because of that gigantic appetite. They got married in a local church and were blessed with two kids: my sister and I. We grew up fast and all took after their father's strength and an outgoing character. As a young couple, my parents loved bowling and so they spent most of their spare time together on the game. My father liked partying a lot, and I can recall once my mother referring to him as a 'party animal' after he came home drank after a night of partying and playing cards with his friends. He worked hard though, and he always had two jobs going, at a minimum, all the days of his youthful life. For example, I remember he took a job as a factory worker for eight hours ever day and then took a four hour break then reported for another job in an apartment store for another six hours. Despite the heavy responsibility of supporting his young wife and the kids, he managed well enough and placed us in good private schools and at the same time affording him self a good and exciting life. He loved baseball and at one point he trained a local club which never did too well anyway. My mom once told me that after my sixth birthday, dad thought that I was old enough to know the game and so he took me along for a trial on the league. Mum came along to watch her men play. She recalls that the ball came to me and as I struggled to concentrate on the ball so had that I missed and it hit me on the face, right between my eyes, I was so embarrassed. He was a good father and had time for the kids, taking them swimming twice every week and for ice cream every Sunday afternoon. They would take the 'wife' along once in a blue moon just to keep the whining away for lack of due attention from the hubby. Sometime in her late thirties, in his late forties, one of my father's friends offered him the chance to cruise on a cruiser leaving Florida to the island. My father's wish has always been to be able to support his family without having to rely on either loans or on borrowing from the family. And so he took the

What relationship can you draw between the ideas of the global village Essay

What relationship can you draw between the ideas of the global village and collective intelligence and how will this impact your professional work - Essay Example Thus, we no longer live in unconnected and detached spots but a ‘global village’. Furthermore, this participation makes what we call ‘collective intelligence’ possible, and that is what is discussed below and how it impacts our lives. What collective intelligence means is that the intelligence of individuals and groups can be pooled together and used in several powerful ways. The actual concept was propounded by Levy (1997) though it is a part of the spiritual concept of ‘collective consciousness’. It was envisioned that networked computers would be able to enhance the totality of human knowledge in a number of ways – by â€Å"facilitating interaction among people†¦[and] promoting [their] participation† (Brand, 2007), and allowing the construction of ‘super databases’. McLuhan (1964) and Boorstin (1978) suggested long ago that we would be living in a ‘boundless global village’ because they foresaw the potential of electronic communication and the evolution of computers and the Internet. The former saw the global village as extending â€Å"or nervous system in a global embrace, abolishing both space and time as far as our planet is concerned† (Symes, 1995). Building on from the earlier World Wide Web, it is evident that a new phase has been reached named as Web 2.0 To take advantage of or ‘harness’ this collective intelligence, many businesses for example have moved entirely onto the Internet and are applying its principles to achieve what they could only imagine before. Thus, another feature of Web 2.0 is the building of special applications that â€Å"harness network effects [to] get better the more people use them† (O’Reilly, 2006). One example of this is the online ‘Wiki’ encyclopedia whose information rests on user contributions (wikepedia.org) The ‘wiki principle’ in general is inviting for people to participate as it gives them power to make useful

Best Buy Case Study Essay Example for Free

Best Buy Case Study Essay After acquiring a stake in Five Star, a retailer of appliances and electronics in China, Best Buy’s VP John Noble is responsible for launching a dual brand strategy to China as he did in Canada back in 2002. The plan was to open three stores in less than two years in China while Five Star was planning on opening 25 additional stores. Entering China would prove to be much more difficult than neighboring Canada as a country with 1. 3 billion consumers which is a lot of people to please. China was chosen as the second international expansion market primarily due to the overall market opportunity, consumer fundamentals and macro-economic factors (Ivey, 2006). † In addition to the Chinese being very frugal, there was also the issue of the concept of credit, or lack there of in China. About four percent of households in China used credit cards, compared to 75 percent in the United States (Ivey, 2006). Best Buy quickly realized that branding in China was not what really attracted the consumers (Ivey, 2006). Best Buy Inc Best Buy had been interested in entering China since the 1990’s. By that time, China had been hosting many of the United States and Europe as far as different manufacturing products. The option of dual branding was what Best Buy was thinking in order to essentially join forces with Chinas retailer of electronics and appliances, Five Star. By coming together, Best Buy in United States thought that the two companies would be even stronger as one. This sort of dual branding worked very well in Canada and presumably would have the same success in China. Competitors Some of the main competitors of Best Buy are Wal-mart and Costco. The competitors were constantly increasing their CE retail market and in particular they increased the products that were less complex therefore easier to sell. Internet shopping and distributors such as Amazon or sites like that are another example of a competitor in the CE market. Also, home improvement stores such as Home Depot and Lowe’s were also venturing into unknown territory which was competition for Best Buy. â€Å"Lines were blurring as retailers of all kinds were widening their product assortments in pursuit of revenues and margins (Ivey, 2006). † Dual branding in Canada seemed like logical step in that Best Buy and Canada’s Future Shop, the main CE retailer there could join together and become stronger with all of the competition coming about (Ivey, 2006). Dual Branding Canada Canada was paid $363. 95 million dollars to acquire Future Shop. Among several reason why the dual branding took place, the number one reason and most important was that Future Shop was an established brand â€Å"with over 95 percent unaided brand awareness among Canadians (Ivey, 2006). † Though dual branding seemed like a great idea there were also some downsides. Cannibalization was the main problem of course due to the products of Future Store eating the profits of Best Buy and vice versa. There was also the immanent issue that the consumer would not know which brand was which. Despite these issues, by the first year of operations the dual branding strategy seemed to be working and cannibalization seemed minimal. It seemed only natural to give it a try in China (Ivey, 2006). Dual Branding China â€Å"China was chosen as the second international expansion market primarily due to the overall market opportunity, consumer fundamentals and macro-economic factors (Ivey, 2006). However the Chinese consumer was different than that of the United States or Canada. Also, consumers were not really concerned with branding as much as they were messages relating to functional features. Therefore, the preference of brand did not really translate into revenue. There was also the issue of land acquisition as there were often delays which would force a store to take up to 6 months to even open its doors. The Chinese also preferred to deal with people they knew and had previous relationships with so pricing had to be up to par due to the consumer not providing much slack for it. With all of these problems, a dual branding in China did not seem as seamless as it was in Canada (Ivey, 2006). Conclusion It is understandable why Best Buy would want to go global to maximize its profit and consumer base all over. Though things seemed to work out in Canada, it would prove to be a much tougher hill to climb in China just based off the consumers alone and the way things are done there and simply the way of life. It will be interesting to see if the places like Turkey and Mexico, other potential targets will have the same success rate as Canada, and not resemble China’s issues.

Introduction to Criminal Justice Essay Example for Free

Introduction to Criminal Justice Essay This definition of a crime comes from (Merriam-Webster On-line Dictionary) and reads; â€Å"Crime: an act or the commission of an act that is forbidden or the omission of a duty that is commanded by a public law and that makes the offender liable to punishment by that law; especially: a gross violation of the law†. There are several definitions of crime, but there all consistent for the most part. People who commit crimes are held to answer for the crimes they are accused of. For this, we must have a judicial system in place that is fair and balanced. Although the person accused of committing the crime is sometimes judged before he’s even gone to court, he must be allowed certain rights and due process. Those rights must not be violated prior to a trial. It’s this system that makes American what we are. Sometimes there are cases that make us feel that the person being tried should just be executed or sent to jail, because the media has basically tried and convicted the person prior to trial. This was evident in the â€Å"Casey Anthony† murder trial. Most Americans and the media had convicted her prior to trial. She was found not guilty earlier today by twelve jurors. Is the system fair? Who knows, but this is the reason, lots of people believe there should be professional jurors for high profile cases like this. On the other hand our judicial system has been around for a long time and delivers in most cases a fair system of government that protects the innocent, the victims and the accused. Of course all parties involved don’t feel this way based on where you’re at during the judicial process, but it’s a system that’s fair to all parties. The system is overseen by federal systems that try to keep order and balance throughout the country. Without any of this we would be a country with no law and order. Vigilantes’ would run the streets creating their own laws and chaos would prevail. The three components of the criminal justice system are The Police, The Criminal Courts and The Correctional Institutions. Each one of these components has a very specific function and go hand in hand with one another. For example; if a person is arrested by a police officer for a residential burglary, there is a series of events that happen on the law enforcement side, before the suspect goes to court and before he becomes a part of the correctional institutions. . Once an officer confirms a crime has been committed, he must place the person under arrest and show there was probable cause to arrest the person. This information goes into a â€Å"Probable Cause statement that’s submitted during the booking process. If the suspect is questioned he must be advised of his Miranda rights by the law enforcement officer. Evidence must be collected to prove the crime was committed and the person being charged committed the crime. The suspect is then transported to the county jail for booking. The officer must then document the incident in a police report and be able to articulate the elements of the crime have been fulfilled. The evidence must be booked and the police report must then be submitted to the District Attorney’s office within a 48 hour time frame before the suspect is arraigned in court. If any of this fails’ to happen the courts could release the suspect under Penal Code 825. The case can still be submitted to the District Attorney’s office, but it will be filled out of custody. If this process has been completed correctly the criminal courts takes over their function. Once the suspect goes to court for his first appearance he is advised of his charges and the probable cause is confirmed by the courts. During this phase the report and evidence collected are examined by the defense counsel to see if the suspect has a chance of winning the case. If the defense attorney feels that his client may lose the case based off of the evidence presented he may be allowed to plea bargain in which the suspect could plead to a lesser crime or admit guilt to the crime he is accused of. There are several things that determine if this allowed to happen, to include the suspects past criminal history and the seriousness of the crime. If the courts feel there is enough probable cause and the suspect’s rights have not been violated, the suspect will be held to answer to the charges brought against him. Otherwise the suspect could be let free based on the lack of probable cause, lack of physical evidence or the suspect’s rights being violated during the arrest or questioning process. If the suspect is held to answer he will then go to an arraignment. Once there he will plead either not guilty, guilty, or no contest. If a person pleads â€Å"not guilty† he is set for pre-trial at which time his case is handled by the person’s lawyer. If need be the case goes to trial where he is judged by twelve of his peers or the person pleads to a lesser charge and the case is closed prior to the trial. If a trial takes place and the person is found guilty he will be sentenced by the judge based on the crimes committed. This can be immediately or shortly after the trial. If the suspect is sentenced to prison he then becomes a part of the correctional institution. After sentencing he is usually turned over immediately to the custody of the sheriff’s department while awaiting transportation to prison.

Mental Health Definition and Case Study

Mental Health Definition and Case Study This assignment is going to explore about what mental health is and make a distinction between mental disorders and mental illnesses. A case study of a patient suffering with depression is going to be incorporated within the assignment. The assignment will also define what depression is and address the possible causes, symptoms, medication and therapies that could be used to change the mental health state of the patient. Changes in the mental health state of the individual will be explored showing the differences between a patient with depression and a person who does not suffer with depression. Gibbs, (1988) reflective cycle is going to be used together with Fleming, (1987) learning needs and styles models to reflect on own personal learning needs. SWOT analysis is going to be use in included reflecting on Strengths, Weaknesses, Opportunities and Threats. In accordance with the Nursing and Midwifery Council (NMC) code of conduct, (2008) and Data Protection Act, (1998) confidentialit y and anonymity will be maintained throughout the assignment. In order to give a depth answers to the above question, it is necessary to briefly mention the importance of mental health and mental illness in our society. Mental health is defined as ‘a continuum of experience, from mental well being through to a severe and enduring mental illness ‘(Austin and Priest, 2005).Kakar, (1984) also define mental health as a label, which covers different perspectives and concerns, such as the absence of incapacitating symptoms, integration of psychological functioning, effective conduct of personal and social life, feelings of ethical and spiritual well-being. In (2007) the WHO define mental health as conceptualized as a state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community. In this positive sense, mental health is the foundation for well- being and effectuating for an individual and for a community. (DH 2001), defined mental health as ‘thinking, feeling and physical health and well-being‘. The world Health Organisation (WHO), (2001) defines health as ‘a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. Mental health problems are more common in people with a learning disability which is the authors chosen branch of work. It is important to have a good knowledge about what health is before defining what mental health is. The WHO uses a holistic approach when looking at health. The (2004) WHO report on â€Å"Promoting Mental Health† stated that â€Å".mental Health and mental illness are determined by multiple and interacting social, Psychological and biological factors, just as health and illness in general. Mental health implies fitness rather than freedom from illness† (WHO, 2004 p 13). Norman and Ryrie, (2009) are not in full agreement of WHOS definitions of health and mental health. They suggest that, these definitions are little value. However they are in agreement with their 2007 definitions and suggest that it hold more promise. They suggest it relates more to their quadrant concept of ‘self and ‘community. Norman and Ryrie are in the agreement with the WHOS definition they believe it is slightly complex and they suggest that, the authors Keyes (2002) and Huppert (2005) use more simpler approach to defined positive   mental health and well-being. The use terms such as hedonic and eudaimonic.Hedonic means positive feelings and positive affect, which reflect subjective well-being and eudaimonic means positive fu nctioning, which includes engagement, fulfilment and social well-being. Mental health is the capacity to live life to the full in ways that enables us to realise our own natural potentialities, and that unite us with rather than divide us from all other human beings who make up our world (Guntrip 1964).According to the Department of Health (1995), mental health consists of four key capacities: The ability to develop psychologically, emotionally, intellectually and spiritually, the ability to intiate, develop and sustain mutually satisfying personal relationships, the ability to become aware of others and to empathise with them and the ability to use psychological distress as a development process, so that it does not hinder or impair further development. Depression REFLECTION Schon, (1983) define reflection as a process of thinking with a purpose and focused strongly on the need to test out and challenge true beliefs by applying the scientific method through deductive reasoning and experimentation and also implied that emotions and feelings are part of reflective thinking. Reflection is an active persistent and careful consideration of any belief or supposed form of knowledge in the light of the grounds that support it and the further conclusion to which it tends Dewey (1933).Using Gibbs reflective Cycle, (1988) appendix 1 and Neil Flemings Vark system, (1987) I will reflect on my experiences on my practise ward and on my theory. By having the chance to completed Flemings Vark questionnaire and my result was multimodal. This showed that I could learn by reading and writing literature, learning using visual aids, aurally and using kinaesthetic methods. I intend to reflect on my communication skills, literacy skills IT skills using Gibbs cycle. Gibbs cycle is a six stage cycle which helps the reader to reflect on situations, analyse feelings and evaluate experiences, conclude situations and how a person would deal with experiences again if they rose. REFERENCES Austin M.P and Priest S.R 2005 Acta Psychiatrica Scandinavica (Online) 112(no.2) Norman Ian and Ryrie Iain 2009, the Art and Science of Mental Health Nursing, Second Edition, Open University Press BIBLIOGRAPHY Andrews, G and Jenkins, R (Eds) 1999 Management of Mental Disorders