forensics Flashcards

Question

what is analysis of low copy number DNA?

Answer 1

LCN = low copy number same discriminatory power as routine DNA profiling copy 10 informative sites (STR regions) from smaller amount of starting material takes longer to process > used for small/old sample to build at least a partial profile

Answer 2

used for familial searching prioritise using specific parameters (location and police intelligence) can use low copy number profiling

Answer 3

> familial searching > cold cases > too much DNA mixed together ?

Answer 4

computer-based analysis system to interpret mixtures of DNA

Answer 5

an unsolved criminal investigation which remains open pending the discovery of new evidence.

Answer 6

Familial DNA searches simply identify “potential” relatives of an alleged perpetrator. A familial DNA search result is only a lead that is then followed up and investigated until a DNA sample of the suspect is obtained and tested.

Answer 7

> assess likelihood of being involved in a crime > tracing family > tracing relation to certain specific families

Answer 8

it is not always easy to identify a person e.g. tsunami on 2004 which killed ~300,000 people so DNA is taken to try and identify individuals

Answer 9

new extraction methods from bone mini STRs SNPs

Answer 10

to give families closure and to identify the number of individuals that have died

Answer 11

> mutations in genes can lead to defects > genetic diversity - polymorphisms > mutations within restriction sites changes the sizes of fragments > detect genetic diseases by RFLP or PCR > e.g. sickle-cell anaemia, cystic fibrosis

Answer 12

current standard forensic DNA tests do not look at genes

Answer 13

>trade in wildlife; illegal trade in protected species, illegal killing of protected species, poaching >threat to species >non-human DNA- crimes against people/property >conservative + breeding management >evolutionary analysis >dogs; cause of human injury/death, victim of neglect/abuse >rats and rodents; cause of post mortem damage to flesh and bones

Answer 14

should we all have our DNA profiles on a central database? >would this make most crimes solvable? >would it result in unfair convictions/framing? >is it an invasion of privacy? *many people freely give their DNA to commercial databases

Answer 15

A collection of these can give nearly irrefutable evidence statistically of a person's identity because the likelihood of two unrelated people having the same number of repeated sequences in these regions becomes increasingly small as more regions are analysed.

Answer 16

any long thin flex solid object with a high length to transverse cross-section area ratio

Answer 17

human/animal body area race artificial alteration damage

Answer 18

medulla (inner) cortex (middle layer) cuticle (outer)

Answer 19

microscopy acid phosphatase p-30 *semen is a good source of DNA (seminal fluid - sterile; no sperm)

Answer 20

N-napthyl phosphate + ortho-deianisidine

Answer 21

starch/iodine salivary amylase *saliva may contain bacterial/cheek cells

Answer 22

may contain bacterial or cheek cells

Answer 23

is the sample blood? is the sample animal blood? if animal blood, what species? if human blood, what type? *sex, age and race of the source

Answer 24

not entirely specific false reactions obvious stains haemoglobin enzyme/catalyst red blood cells and platelets have no DNA

Answer 25

leuchomalachite green; LMG (reduced) -> LMG (oxidised) *green kastle meyer test; Phenolphthalein (reduces) -> phenolphthalein (oxidised) *red luminol-chemiluminescence in the presence of Hb luminol + H2O2 -> 3 aminophthalate (light producing eraction)

Answer 26

> to provide info regarding the sequence of events; - position of the victim - evidence of struggle > to provide evidence to corroborate or refute statements made by those involved - stain patterns on suspects clothing - stain patterns on victim/at scene

Answer 27

bloodstain pattern analysis: the examination of shapes, locations and distribution of blood stains, in order to provide an interpretation of the physical events which gave rise to the origin

Answer 28

passive stains; due to gravity, drops, drips, pools, clots, shape affected by target surface transfer stains; wet bloody surface in contact with another surface produces a pattern (contact, swipe/smear, wipe, smudge) active stains; projected, arterial spurt/gush, cast off stains, impact (low, medium, high velocity), point of convergence

Answer 29

Reactive: Response to evidence that is already identified or clearly visible. It’s specific and focused on analysing known samples. Inceptive: Proactive search for hidden or less obvious evidence. It’s more exploratory, aiming to uncover traces that aren’t immediately apparent.

Answer 30

(pharmacology) sometimes described as what the drug does to the body, is the study of the biochemical, physiologic and molecular effects on the body and involves; receptor binding, post receptor effects and chemical interactions.

Answer 31

(pharmacology) sometimes described as what the body does to a drug, refers to the movement of the drug into and out of the body- the time course of its; absorption, distribution, metabolism and elimination

Answer 32

> ethyl alcohol (ethanol) is clear, colourless and miscible with water > it contains by products and additives which give it colour and flavour > alcohol is produced from grapes/cereal grains

Answer 33

brain kidneys lungs liver mouth-> oesophagus->stomach+small intestine-> circulatory system->(brain, kidneys, lungs, liver)

Answer 34

> quantity > concentration > contact time in GIT > food > stomach emptying

Answer 35

> rapid > distribution to all organs and body compartments in proportion to that compartments water content > most organs and fluids are in constant equilibrium with blood

Answer 36

under 50; not obvious, talkative 50-100; slurred speech, bravado, some co-ordination loss 100-150; marked loss of gait, possible nausea 150-200; nausea, non co-operative, total loss of interest 200-300; probable coma 300-400; coma, impaired respiration 400+; death may ensue from respiratory paralysis

Answer 37

metabolism -> 90% ethanol-> acetaldehyde->CO2 + water this reduced BAC (blood alcohol content) by approximately 15mg/100ml - 18mg/100ml per hour (0.015-0.018%/hour)

Answer 38

CH3CH2OH + NAD+ -> CH3CHO + NADH+ (alcohol dehydrogenase) CH2CHO + NAD+ + H2O -> CH3COO- + NADH+ (aldehyde dehydrogenase)

Answer 39

genetics; ADH- number of isozymes with different structural, physical and chemical properties. Fast and slow metabolisers. pharmocokinetics; zero order kinetics- clearance is zero order with respect to ethanol. cleared at a constant rate regardless of concentration. also depends on liver size and body mass.

Answer 40

a chemical reaction in which the rate is independent of the concentration of the reactants, i.e. the rate does not change when the concentration of the reactants increases or decreases.

Answer 41

Alcohol affects nearly every system in the body, with effects ranging from mild relaxation at low doses to severe physical and mental health risks at high or chronic levels. The short-term impacts include euphoria, lowered inhibitions, and impaired coordination, while long-term heavy use increases the risk of liver disease, cancer, cardiovascular issues, addiction, and neurological damage. Each person’s reaction to alcohol varies due to factors like genetics, age, body weight, and drinking patterns, underscoring the importance of moderation.

Answer 42

Alcohol metabolism in the human body involves a sequence of enzymes that work primarily in the liver to break down ethanol, the main component of alcoholic beverages. The two primary enzymes involved are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Additionally, a secondary enzyme system called the microsomal ethanol oxidizing system (MEOS) plays a role in alcohol metabolism, especially at high alcohol concentrations or in chronic drinkers. Here’s a closer look at each of these enzymes: 1. Alcohol Dehydrogenase (ADH) Function: ADH is the primary enzyme responsible for initiating alcohol metabolism. It catalyzes the first step, converting ethanol into acetaldehyde, a toxic and reactive intermediate. Location: ADH enzymes are predominantly found in the liver but are also present in the stomach lining and other tissues. Reaction: Ethanol + NAD⁺ → Acetaldehyde + NADH Variants: Genetic variations in ADH isoenzymes can significantly affect the rate of ethanol breakdown. Some people, especially certain East Asian populations, have more active ADH variants, which rapidly convert ethanol to acetaldehyde, leading to an accumulation of acetaldehyde and, subsequently, a quick onset of symptoms like flushing. 2. Aldehyde Dehydrogenase (ALDH) Function: ALDH catalyzes the second step in alcohol metabolism, converting acetaldehyde into acetate, a relatively non-toxic compound that can be further broken down into water and carbon dioxide. Location: ALDH is mainly located in the liver, with smaller amounts found in other tissues. Reaction: Acetaldehyde + NAD⁺ → Acetate + NADH Variants: Genetic differences in ALDH activity are highly influential in alcohol metabolism. For example, many East Asians carry a genetic variant of the ALDH2 enzyme that is either inactive or less efficient, causing a buildup of acetaldehyde in the blood. This buildup can cause flushing, nausea, and palpitations, a reaction sometimes known as “Asian flush.”

Answer 43

In summary, alcohol metabolism varies due to genetic, physiological, and lifestyle factors. Genetics (enzyme variants) and biological differences (gender, body composition, and liver health) are the most influential, while age, food intake, and chronic drinking habits also play a role in how quickly an individual metabolizes alcohol.

Answer 44

The liver clears most of the alcohol through steady metabolism, converting it first to acetaldehyde and then to acetate. A small amount is eliminated via breath, sweat, and urine. Clearance rates vary by individual factors but are generally consistent due to zero-order kinetics. The clearance of alcohol from the human body occurs mainly through metabolism, with smaller amounts being eliminated through breath, sweat, and urine. The liver is the primary organ responsible for metabolizing alcohol, and this process follows a relatively steady rate that cannot be easily accelerated. Steps in Alcohol Clearance Absorption and Initial Distribution: After ingestion, alcohol is quickly absorbed into the bloodstream through the stomach (20%) and the small intestine (80%). Alcohol then circulates throughout the body, where it distributes mainly into water-rich tissues, such as the brain, lungs, liver, and muscles. Primary Metabolism in the Liver: The liver metabolizes approximately 90-95% of the alcohol consumed. The remaining 5-10% is excreted unchanged through urine, sweat, and breath. The liver metabolizes alcohol in a two-step enzymatic process involving: Alcohol Dehydrogenase (ADH): Converts ethanol (alcohol) into acetaldehyde, a toxic substance that causes unpleasant symptoms if it accumulates. Aldehyde Dehydrogenase (ALDH): Rapidly converts acetaldehyde into acetate, which is less harmful. Acetate is eventually broken down into carbon dioxide and water, which the body can eliminate easily. Excretion via Lungs, Urine, and Sweat: Lungs: A small portion of alcohol diffuses into the air sacs in the lungs and is exhaled. This forms the basis for breathalyzer tests, which measure the concentration of alcohol in the breath to estimate blood alcohol concentration (BAC). Urine: The kidneys excrete a small amount of unmetabolized alcohol in urine. Since alcohol is a diuretic, drinking alcohol can increase urine production and contribute to dehydration. Sweat: Some alcohol is eliminated through the skin, which can give the skin and breath a faint odor of alcohol. Rate of Alcohol Clearance Fixed Rate of Metabolism: The liver metabolizes alcohol at an average rate of about 0.015% BAC per hour. This rate is relatively constant, meaning that about one standard drink per hour can be metabolized and cleared from the bloodstream. Zero-Order Kinetics: Unlike many drugs that follow first-order kinetics (where clearance rate is proportional to the concentration in the blood), alcohol is metabolized at a constant rate. This is because liver enzymes are saturated even at low alcohol concentrations. Factors Affecting Alcohol Clearance Genetic Variations: Differences in ADH and ALDH enzyme efficiency affect how quickly alcohol is metabolized. Certain genetic variants (e.g., in some East Asian populations) cause slower ALDH activity, leading to a build-up of acetaldehyde, which causes "flushing" and unpleasant symptoms. Age: Younger people tend to metabolize alcohol more efficiently than older adults. Gender: Women typically have lower ADH enzyme levels than men, meaning they metabolize alcohol slightly slower. Additionally, women have a higher body fat percentage and less body water, leading to a higher BAC from the same alcohol intake. Liver Health: Liver diseases like hepatitis or cirrhosis can significantly impair alcohol metabolism, leading to slower clearance and prolonged effects of alcohol. Food Intake: Consuming food before or while drinking can slow alcohol absorption, resulting in a more gradual rise in BAC and potentially reducing peak BAC levels. However, it does not speed up alcohol metabolism. Chronic Alcohol Consumption: Frequent drinking can induce liver enzymes to a small extent, but this does not significantly increase the clearance rate for moderate drinking and is not sufficient to counteract the effects of large quantities of alcohol.

Answer 45

Alcohol concentration in the body, typically measured as blood alcohol concentration (BAC), is the amount of alcohol in a person’s bloodstream. It is most commonly expressed as a percentage, indicating the grams of alcohol per 100 milliliters of blood. BAC is used to assess intoxication levels and its effects on the body and behavior. The concentration of alcohol in the body depends on several key factors: 1. Alcohol Absorption When a person drinks alcohol, it enters the stomach and small intestine, where it is absorbed into the bloodstream. Absorption begins quickly, with around 20% absorbed through the stomach lining and 80% through the small intestine. Factors influencing absorption speed include: Type of Drink: Carbonated drinks speed up absorption as they increase alcohol movement to the small intestine. Alcohol Concentration: Stronger drinks (higher alcohol by volume, or ABV) lead to faster rises in BAC. Food Intake: Food in the stomach slows absorption by delaying alcohol’s passage to the small intestine. 2. Distribution in the Body Once absorbed, alcohol is distributed throughout the body’s water compartments (like blood, brain, and other tissues). Because alcohol is water-soluble, it spreads more in water-rich areas and less in fat tissues. Body Mass and Composition: Leaner individuals with higher water content dilute alcohol more effectively than individuals with more body fat, resulting in lower BAC for leaner people at the same intake. Gender Differences: Men generally have a higher water-to-fat ratio than women, so they typically reach a lower BAC than women from the same amount of alcohol. 3. Metabolism and Elimination The liver metabolizes around 90-95% of the consumed alcohol through enzymatic processes, primarily by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). The rate of alcohol metabolism varies by person but averages about 0.015% BAC per hour. Small amounts of alcohol are eliminated via breath, sweat, and urine, which is the basis for breathalyzer tests. The rate of metabolism is relatively fixed, so factors like drinking coffee or taking cold showers do not speed up the process. 4. Calculation of Blood Alcohol Concentration BAC can be estimated based on body weight, the amount of alcohol consumed, time since consumption began, and metabolic rate. The Widmark formula is a commonly used formula for estimating BAC: BAC=(Alcohol Consumed in grams)(Body Weight in grams)×r−(Elapsed Time×Metabolism Rate) BAC= (Body Weight in grams)×r (Alcohol Consumed in grams)-(Elapsed Time×Metabolism Rate)r (Widmark Factor): This factor is approximately 0.68 for men and 0.55 for women, representing the proportion of body water in which alcohol is distributed. 5. Measuring BAC >Breath Tests: Devices like breathalyzers estimate BAC based on alcohol exhaled in the breath. Since alcohol in the blood is in equilibrium with alcohol in the lungs, breath measurements provide a reasonable estimate of BAC. >Blood Tests: Directly measure the alcohol concentration in blood samples, offering precise BAC values. >Urine Tests: Estimate BAC indirectly and are typically less accurate because they reflect past consumption rather than current blood levels. Summary of Factors Influencing BAC >Amount of Alcohol Consumed: More alcohol results in higher BAC. >Rate of Consumption: Faster drinking leads to higher BAC as the body can’t metabolize alcohol quickly enough. >Body Size and Composition: Smaller or less muscular individuals generally have a higher BAC than larger or leaner individuals for the same intake. >Gender: Women tend to have higher BACs than men after the same alcohol intake due to differences in body water percentage and enzyme levels. >Food Intake: Food slows absorption, leading to a slower rise in BAC. >Metabolic Rate: Varies by individual and affects how quickly BAC decreases. By accounting for these factors, BAC determination helps assess intoxication, guides legal and medical judgments, and aids in understanding the impact of alcohol on physical and cognitive functions.

Answer 46

The rate of cooling of a body, known as algor mortis, is influenced by several factors in forensic science. Understanding these factors can help estimate the time of death based on body temperature. Here’s an outline of the main factors affecting the rate of cooling of a body: 1. Ambient Temperature Surrounding Environment: The difference between the body’s initial temperature (typically around 37°C or 98.6°F) and the surrounding air temperature significantly influences the rate of cooling. Hot vs. Cold Environments: Bodies cool faster in colder environments and slower in warmer conditions. Extreme cold can lead to freezing, while extreme heat can delay cooling. 2. Humidity and Air Movement Humidity: In high-humidity environments, the cooling rate may be slower as evaporation (a cooling process) is reduced. Air Circulation: Windy or well-ventilated environments speed up heat loss by convection, enhancing the cooling rate. 3. Body Size and Composition Body Mass and Fat Content: Larger bodies and those with higher fat content cool more slowly. Fat acts as an insulator, reducing heat loss. Surface Area to Volume Ratio: Smaller bodies with a higher surface area-to-volume ratio cool faster than larger bodies. 4. Clothing and Covering Type and Amount of Clothing: Clothing acts as insulation, slowing down heat loss. Heavier, thicker clothing or blankets trap heat, delaying cooling. Presence of Wrapping: If a body is wrapped in a material like plastic or heavy fabric, the cooling rate is reduced, as it limits heat loss through both conduction and convection. 5. Body Position and Location Position (exposed vs. concealed): Bodies exposed to open air lose heat faster, while those in enclosed spaces or positioned against insulating surfaces cool more slowly. Contact with Surfaces: Direct contact with cold or conductive surfaces like metal or concrete accelerates heat loss, as the body loses heat via conduction. 6. Environmental Factors Submersion in Water: Water conducts heat away from the body much faster than air, resulting in quicker cooling, especially in cold water. Soil or Ice: Bodies buried or covered in cold substances, like ice or cold earth, will cool faster due to conductive heat loss to these materials. 7. Time Since Death Initial Cooling Phase: In the first few hours after death, the rate of cooling is relatively rapid, as the temperature difference between the body and the environment is greatest. Slowing Rate: As the body temperature approaches ambient temperature, the cooling rate slows, eventually reaching equilibrium with the environment. 8. Environmental or Internal Heat Sources Heat Sources Nearby: Proximity to heat sources (e.g., sunlight, heaters) slows down cooling. Body’s Own Heat Production: In some cases, such as severe infection or physical exertion before death, the body may initially cool more slowly due to retained heat. Summary In forensic investigations, these factors are considered to more accurately estimate the time of death. The body's cooling rate can vary widely depending on environmental conditions, body characteristics, and the presence of insulating factors, all of which can either hasten or delay heat loss from the body.

Answer 47

Decomposition is a complex process in which the body breaks down after death. This process occurs in stages and is influenced by factors like temperature, humidity, presence of insects, and other environmental conditions. The stages of decomposition are generally classified into the following phases: 1. Fresh (0–2 days) Immediately after death: The body is at or near its normal temperature of about 37°C (98.6°F). Cellular breakdown begins: Without blood circulation, cells begin to die, and oxygen depletion causes anaerobic metabolic processes. This leads to the accumulation of waste products inside cells. Autolysis: The body's cells start to break down their own tissues, releasing enzymes that begin digesting the cells from the inside out. Livor mortis (postmortem hypostasis): Blood settles in the lower parts of the body due to gravity, causing a purplish discoloration of the skin. Rigor mortis (stiffening): Muscles begin to stiffen due to the lack of ATP, a condition that typically starts within a few hours after death. Initial changes: The body may begin to lose its natural color, and the skin may become slightly pale or waxy. 2. Bloat (2–6 days) Bacterial growth: The body’s bacteria, particularly in the intestines, begin to break down tissues, producing gases like methane, hydrogen sulfide, and carbon dioxide. Swelling: As these gases accumulate, the body swells, particularly in the abdomen and chest. This can cause the body to appear bloated, sometimes with visible discoloration. Skin changes: The skin may become discolored, turning green or purple as blood decomposes. The skin may also start to blister and peel as the tissues begin to break down. Foul odor: As bacteria and enzymes continue to break down tissues, a strong, characteristic odor of decomposition begins to emanate from the body. Rigor mortis fades: After a few days, rigor mortis begins to dissipate as the muscles start to break down. 3. Active Decay (7–21 days) Tissue liquefaction: The tissues continue to break down, and much of the body’s soft tissue starts to liquefy. This results in the release of fluids, contributing to the body's decomposition. Advanced bloating: The body becomes even more bloated as the gases continue to accumulate and pressurize the body. Maggot and insect activity: At this stage, insects like blowflies, maggots, and beetles are actively feeding on the body, especially on the flesh, aiding in the breakdown of soft tissues. The presence and activity of these organisms can help forensic scientists estimate the time of death. Skin slippage: The skin may begin to detach from the underlying tissue due to the breakdown of collagen. Dehydration and liquefaction: In hotter conditions, parts of the body may dry out and mummify, while other areas continue to liquefy. 4. Advanced Decay (21 days to several months) Significant loss of tissue: Much of the body’s soft tissue, including muscles and organs, has decomposed or been consumed by insects. Only skeletal remains, ligaments, and cartilage may remain. Reduced bloating: As more fluids are lost from the body and the gases have mostly escaped, the bloating starts to decrease. The body may appear sunken or shriveled. Skeletonization begins: The soft tissue around bones continues to decay, leaving behind a skeleton. Insects, particularly beetles, may continue to feed on the remaining tissue. 5. Skeletonization (Several months to years) Complete breakdown of soft tissue: By this stage, most or all of the body’s soft tissue is gone, leaving only bones and possibly some cartilage. Preservation of bones: The rate at which the skeleton decomposes depends on the environmental conditions. In dry, cold, or anaerobic environments (such as burial in peat bogs), bones can be preserved for many years or even centuries. Changes to bones: Over time, bones may begin to decompose through chemical processes like the breakdown of collagen. They can also be consumed by organisms like scavengers or insects, leading to further degradation. Factors Affecting Decomposition Temperature: Warm conditions accelerate decomposition by promoting bacterial growth and enzyme activity, while cold temperatures slow the process. Humidity: High humidity can speed up decomposition by aiding bacterial growth, while dry environments may slow it. Oxygen availability: In open air (aerobic conditions), decomposition is faster than in an anaerobic environment (such as water or soil). Insect activity: The presence of scavengers and decomposers like flies and beetles significantly accelerates decomposition, particularly in the bloat and active decay stages. Cause of death: Trauma, disease, or other factors influencing the condition of the body at the time of death can also affect the rate of decomposition. Summary Decomposition progresses through several stages: fresh, bloat, active decay, advanced decay, and skeletonization. These stages are influenced by environmental factors such as temperature, humidity, and insect activity, as well as the body's size and condition. Understanding these stages helps forensic experts estimate the time of death and gain insight into the conditions surrounding the death.

Answer 48

The Post-Mortem Interval (PMI) can be estimated using Total Body Score (TBS) and Accumulated Degree Days (ADD), two metrics that take into account environmental factors and stages of decomposition. Here’s a breakdown of how to use TBS and ADD to estimate PMI: 1. Understanding TBS and ADD Total Body Score (TBS): TBS is calculated by scoring specific decomposition changes in three main regions of the body: the head/neck, trunk, and limbs. Each region is given a score based on observable characteristics (e.g., skin color changes, bloating, tissue breakdown), and these scores are then summed to provide an overall TBS. Higher scores indicate more advanced decomposition. Accumulated Degree Days (ADD): ADD represents the cumulative environmental temperature exposure experienced by the body over time. It is calculated by summing the average daily temperatures from the time of death onward. The idea is that decomposition progresses more quickly in warmer environments, so ADD helps account for temperature variations in PMI estimates. 2. Using TBS and ADD Together The relationship between TBS and ADD is used to estimate PMI. Generally, this is achieved by: Determine the TBS: Assign a TBS to the body based on observed decomposition characteristics. Use an Established TBS-ADD Regression Model: Many forensic studies have established models that correlate TBS with ADD based on empirical data. These models use regression equations or reference charts that allow forensic scientists to estimate ADD from a given TBS. PMI=ADD/average daily temperature

Answer 49

Cross-discipline collaboration is essential in forensic investigations to provide a comprehensive understanding of the case. For example, in a homicide investigation, various experts contribute: Forensic Pathologists determine the cause of death. Entomologists estimate time of death using insect activity. Anthropologists help with identifying the deceased through skeletal analysis. Toxicologists test for substances that could have contributed to death. DNA Experts assist with identification from biological samples. Collaboration ensures accurate time of death estimation, cause of death, and identification. It also reduces errors and improves efficiency in solving complex cases.

Answer 50

post-mortem interval > the time that has elapsed since an individual's death - accuracy of estimating the time since death is negatively correlated with the time that has elapsed since death occurred support or refute witness/suspect statements

Answer 51

physical - post mortem changes, presence of insects environmental - indoor, outdoor, buried, water, burned historical - victim habits/daily routine, relationships additional evidence - stopped watch, phone records etc. *watch might stop if body was in water

Answer 52

the first stage after death

Answer 53

the closer the body is found to time of death, the more accurate the estimate for time of death is

Answer 54

ENHANCE - small body size - low fat content - body stretched out - body disembered - serious blood loss - lack of clothes - wet clothes - strong air currents - low ambient temperature - body in cold water DELAY - large body size - high fat content - foetal position - clothing - insulative covering - protection from draughts - warm ambient temperature - warm microclimate - exposed to the sun - high humidity *must be taken into consideration when estimating time of death

Answer 55

hypostasis; - settling of blood due to gravity - pale areas (pallor) = areas of pressure - body positioning, items in contact, movement of body - not as useful for PMI *blood migrating towards ground causing discolouration. areas most in contact with ground will appear white due to pressure. This is important to keep in mind to identify if the body has been moved (is the crime scene the location of death?)

Answer 56

pale areas due to pressure typically found in hypostasis (livor mortis)

Answer 57

- stiffening of muscles - caused by reduction in available ATP - evident in smaller muscles first - earliest signs 3-6 hours following death - max rigor between 6-12 hours - completely disappeared by 24-36 hours - affected by temp, muscle mass, physical activity before death *due to the reduction of ATP in body. Can give more into about time of death than livor mortis due to specific hours. Different variables affect livor mortis.

Answer 58

6-12 hours *earliest signs 3-6 hours following death. completely disappeared after 24-36 hours

Answer 59

temperature muscle mass physical activity before death

Answer 60

stiffening of muscle is due to the reduction in ATP

Answer 61

rigor mortis. due to specific hours at which stiffening occurs. *earliest signs 3-6 hours following death. max rigor 6-12 hours after. completely disappeared after 24-36 hours

Answer 62

fresh, bloat, active decay/putrefaction, advanced decay, dry remains/skeletonised fresh; body starts to cool and autolysis begins. hypostasis and rigor mortis may be seen bloat; discolouration of skin surface, body sweels from accumulation of gasses. Tongue protrudes, fluid expelled from orifices (openings in body). Soft tissue visibly decaying. Rapid decay owing to intense microbial and invertebrate activity. active decay/putrefaction; tissues begin to liquify. Skin can start to blacken. Body deflates as composition gasses escape (purge) advanced decay; progressive loss of skin and soft tissues. Decay owing to invertebrate and microbial activity start to slow down once soft tissues removed and body starts to dry out. dry remains/skeletonised; skin and soft tissues lost. decay proceeds more slowly. progressive loss of uterus/prostate gland, tendons, cartilage, fingernails, hair. Skeleton may become disarticulated through environmental and biological processes.

Answer 63

decomposition gasses escape (body deflated) - body fluids become forced out of body orifices

Answer 64

fresh; body starts to cool and autolysis begins. hypostasis and rigor mortis may be seen

Answer 65

bloat; discolouration of skin surface, body sweels from accumulation of gasses. Tongue protrudes, fluid expelled from orifices (openings in body). Soft tissue visibly decaying. Rapid decay owing to intense microbial and invertebrate activity.

Answer 66

active decay/putrefaction; tissues begin to liquify. Skin can start to blacken. Body deflates as composition gasses escape (purge)

Answer 67

advanced decay; progressive loss of skin and soft tissues. Decay owing to invertebrate and microbial activity start to slow down once soft tissues removed and body starts to dry out.

Answer 68

dry remains/skeletonised; skin and soft tissues lost. decay proceeds more slowly. progressive loss of uterus/prostate gland, tendons, cartilage, fingernails, hair. Skeleton may become disarticulated through environmental and biological processes.

Answer 69

greenish discolouration - lower right quadrant first - breakdown of haemoglobin by intestinal bacteria skin slippage - separation of epidermis from dermis - blistering - de-gloving (fingerprints) marbling - bacteria from abdomen spread via blood vessels - superficial veins (fark purple/green) - marbles effect bloat - build up of gases - by-product of decomposition - can rupture - foul smelling purge - body fluids become forced out of body orifices

Answer 70

due to the breakdown of haemoglobin by intestinal bacteria

Answer 71

bloat - build up of gases - by-product of decomposition - can rupture - foul smelling

Answer 72

marbling - bacteria from abdomen spread via blood vessels - superficial vein

Answer 73

skin slippage - separation of epidermis from dermis - blistering - de-gloving (fingerprints)

Answer 74

desiccation of remains happens in hot/cold DRY environments skin dries out - leathery appearance *can preserve features

Answer 75

grave wax - favoured by DAMP conditions - formed by hydrolysis of body fats - usually when body is partially/completely in water *can preserve features

Answer 76

both can preserve features *these two phenomena's modify the natural decomposition of a body and can preserve features

Answer 77

post mortem interval a visual analysis (qualitative) can be completed - highly variable (temperature, environment, clothing, body size, scavenging) ADD (accumulated degree days); total temperature or cumulative degrees that the body has been exposed to (accounts for ~80% or variation in decomposition) TBS (total body scoring) system developed; body regions scored separately ADD and TBS are used to calculate PMI > score the body decomposition (TBS) > work out how many days it would take to get to that level based on ADD > work backwards from date of discovery to determine post-mortem interval (PMI)- add up average daily temperatures for area until get to ADD ADD=10(0.002*TBS*TBS+1.81)+/- 388.16

Answer 78

accumulated degree days. total temperature or cumulative degrees body has been exposed to account for ~80% of variation in decomposition.

Answer 79

decomp will occur down to 0 degrees celcius due to salt concentrations in human body

Answer 80

Drugs of abuse typically lead to immediate euphoria, but long-term use can result in dependence, addiction, and severe health risks. Prescription drugs are designed for medical use, but misuse can lead to similar risks, such as dependence and overdose. Monitoring and appropriate use are crucial to minimize harmful effects.

Answer 81

Drugs can be detected in the body through urine, blood, saliva, hair, sweat, and breath testing, with each method offering specific advantages based on the detection window, the type of drug, and the purpose of the test. Understanding the detection methods and factors involved helps in accurately identifying drug use and its impact on health or legal situations.

Answer 82

- road traffic act offences - drink driving - drug driving - drug-facilitated sexual assault - hair testing for social services - sudden or suspicious deaths

Answer 83

' what is there that is not poison?' all things are poison and nothing without poison solely the dose determines that a thing is not poison

Answer 84

Class A: High potential for harm, serious legal consequences (e.g., heroin, cocaine, LSD). Class B: Moderate potential for harm, less severe penalties (e.g., cannabis, amphetamines, codeine). Class A; major natural and synthetic opiates, cocaine and crack cocaine, LSD, injectable amphetamines, cannabinol, magic mushrooms, ecstasy Class B; oral amphetamines, cannabis plant material and resin, codeine, dihydrocodeine, certain barbiturates Class C; benzodiazepines, methaqualone, gamma hydroxybutyrate (GBA), ketamine

Answer 85

stimulants; - primarily stimulates brain activity - e.g. amphetamines, cocaine depressants; - primarily inhibits brain activity - e.g. alcohol, barbiturates, benzodiazepines, heroin hallucinogens; - induces alterations in perception and mood - e.g. ecstacy, lysergic and diethylamide, cannabis

Answer 86

- qualitative/quantitative - bulk/trace - chronic/acute - screening - confirmation - targeted analyses

Answer 87

- presumptive tests - thin layer chromatography - column chromatography - HPLC - gas chromatography - mass spectrometry - immunoassay - spectroscopy

Answer 88

Drugs like nicotine, cocaine, and heroin can bind to melanin in hair. Since these drugs are weak bases, they can enter the hair and become trapped as the hair grows. When someone uses these drugs, the metabolites (byproducts) they produce can also be incorporated into the hair. Key points: Drug Binding: Drugs bind to melanin in the hair, which acts like a trap. Hair Growth: Hair grows about 0.35 mm per day, or roughly 1 cm per month. Detection: By analyzing hair, it's possible to detect both the drugs themselves and their metabolites, which show that the substances have been in the body for a longer period (months, not just days like in urine tests). Free Base/Smoke: Some drugs like nicotine, cocaine, and heroin, when heated or smoked, become uncharged/free bases, which helps them pass more easily into the body through the lungs. *Hair analysis allows for the detection of drug use over time rather than just at the moment of testing, offering a longer detection window (months) compared to other tests like urine.

Answer 89

pharmacokinetics: the study of the ADME processes over a period of time pharmacodynamics: the study of the does versus pharmacological response pharmacogenetics: the study of genetic influence/variances on the ADME processes **ADME; absorption, distribution, metabolism and elimination

Answer 90

absorption, distribution, metabolism and elimination

Answer 91

dose response curve sensitisation; second time may have enhanced immune response tolerance; when repeatedly exposed accumulation; long half-life bioavailability; proportion of original dose absorbed and rate absorption takes place

Answer 92

methamphetamine- stimulant - adimistration; inhalation, oral, snorting, injection - action; increased dopamine effects: > increased wakefulness and physical activity > decreased appetite > faster breathing > rapid and/or irregular heartbeat > increased blood pressure and body temperature long term effects: > HIV/AIDS > weight loss > severe dental problems ('meth mouth')

Answer 93

ecstasy (molly) > chemically similar to stimulants/hallucinogens increase in activity of; - dopamine; euphoria & increased heart rate & blood pressure - norephinephrine; increased heart rate & blood pressure - other effect; nausea, muscle cramping, blurred vision effects last 3-6 hrs > high doses affect temperature regulation

Answer 94

>extraction from cocoa leaf/chemical synthesis >administration; snorting, injection, oral >stimulant; increases levels of dopamine short term health effects: extreme happiness and energy, mental alertness, hypersensitivity to sight, sound, and touch, irritability, paranoia other health effects: constricted blood vessels, dilated pupils, nausea, raised body temperature and blood pressure, faster heartbeat, tremors and muscle twitches, restlessness

Answer 95

active ingredient; diamorphine, other opiates e.g. codeine names; smack, horse, brown administration; smoking legislation; class A effects; analgesia, dreamy euphoria, sedation, respiratory depression, nausea and vomiting, cough suppression, constipation

Answer 96

> hallucinogen synthesised from lysergic acid > microdots/blotter acids > dosage 50-300mg (20-25mg sufficient) > affects the actions of brain chemical glutamate (NMDA receptors)/seretonin > rapid emotional swings; distortion of a person's ability to recognise reality, think rationally or communicate with others; raised blood pressure, heart rate, body temperature; dizziness and insomnia; loss of appetite; dry mouth; sweating; numbness; weakness; tremors; enlarges pupils

Answer 97

names; pot, week, hash, grass, dope administration; smoking, dabbing, food legislation; depends on preparation (cannabis plant + resin=class B/cannabis oil = class A) effects; euphoria, nausea, hypotension, bloodshot eyes, poor coordination, distortion, munchies speed depends on method of administration (smoking= minutes, oral ~ 1 hour) *hypotension=low blood pressure

Answer 98

prescription drugs street names; moggies, jellies administration; oral, injection actions; depressants, reduce tension and anxiety, drowsiness flunitrazepam- 'date rape'

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