Senior Seminar Research Proposal

Introduction rhetorical entomology is utilise to confine such crimes as murder, suicide, and an unlike(prenominal) turn acts by examining assorted worms instead of victimization tender-hearted tissues. This rhetorical rotating shaft is used to see the post-mortem examination interval of a remains and the piss of closing of a system when all other forms of human evidence (human blood, tissues, hair, etc. ) argon non consec vagabond at the scene. forensic entomologists prefer using insects to break these promoters of finale be character referencesetters case the insects produce similar results as human test materials such as human blood or tissues which yield the best analytical results for the forensic entomologist.The use of forensic entomological evidence has been accepted and used in many courtyards around the world (Anderson, 1999). The use of this woodpecker in court burn down support or refute a suspects alibi and improves the criminal probe against t he suspect (Anderson, 1999). Even though forensic entomology is an efficient tool to use in criminal investigations there atomic number 18 some drawbacks to this analytical tool. Such outrages include improper sight of entomological evidence and improper analysis of insects subsequently collection, resulting in stupid entomological results and a possible false conviction of a suspect.The proposed query of this paper focused on insects existence affected by antithetic cin 1 casentrations of ethyl alcohol during natural insect development and similarly focused on the detection of fermentation alcohol in insects using particle accelerator chromatography mass spectroscopic analysis (GCMS) to determine if insects were signifi piece of tailtly affected by neutral spirits scene. The research as well as focused on the exposure of neutral spirits to the insects and how this exposure affected PMI ( necropsy interval) determination. forensic entomology is a commonly used t ool to determine cause and quantify of termination by examining dissimilar characteristics of insects that atomic number 18 composed at the crime scene.Such characteristics include size of the insect(s) and the life motorcycle stage of the insect collect. forensic entomology becomes the most right and some cartridge clips the only tool ready(prenominal) for determining fourth dimension of death, especially after 72 hours (Anderson and VanLaerhoven, 1996). forensic entomology can also determine if a body has been go from place to place, determine where the death occurred, determine the heading of various types of drugs and toxins boon (if any), wound spot, and determine who the suspect and victim are due to the presence of certain insects on the body (Grisales, et al. 2010). Background/Literature Review there are five levels of decomposition identified by a forensic entomologist when conducting an entomological investigation which include fresh, bloated, active, advan ced, and remains (Grisales, et al. , 2010). These stages of decomposition are important to a forensic entomologist because insects appear on a dust periodically by dint ofout the decomposition cycle which therefore determines the time of death of a corpse. During these levels of decomposition insects begin to r all(prenominal) the corpse some(prenominal) by piloting ( gravid travel) or by burrowing by means of the ground (pupae).Some insects can also r severally the corpse by hatching from egg (larvae) that were placed on the corpse after death. The fresh stage of decomposition involves a drop in body temperature and the appearance of very few flies on the corpse. The insects that are collected are typically larvae and are collected from the mouth of the corpse. The bloated stage of decomposition involves a large augment in the body tip of a corpse due to rainfall exposure. The insects that are collected at this stage of decomposition are larvae found on the back, head, ears, and anus of the corpse (Grisales, et al. 2010). The active decay stage of decomposition involves fly larvae victuals on a corpse which evidentially lowers the body weight of the corpse and an plusd amount of money of fly larvae found in the intestines/ organs of the corpse (Grisales, et al. , 2010). The advanced stage of decomposition involves the fluctuation of body temperature depending on the location of the corpse and an even bigger decrease in body weight due to increased consumption of body tissues by fly larvae (Grisales, et al. , 2010).There is an increase in adult flies that are collected at this stage of decomposition. In the last stage of decomposition, remains, there is no continued deepen of the corpse and the presence of insects found decreases (Grisales, et al. , 2010). The stages of decomposition and the insects present at these stages are also used to determine the postmortem interval (PMI) of a corpse. PMI, or postmortem interval, provides important det ail of situations that occurred onwards time of death in cases of homicide and untimely death (Byrd and Castner, 2001).Arthropods that are found on the corpse can determine the length of egg to fly transformation then to the retrieve developmental stage (Gennard, 2007). The best arthropods to use are the oldest ones that were yielded from eggs when the larvae were counterbalance deposited on the corpse because they control the longest feeding time on the corpse which allows them to fully develop and retain any evidence from the corpse frequently longer this will produce a more accurate PMI. Such information can help to identify both(prenominal)(prenominal) the criminal and the victim by eliminating the suspects and connecting the deceased with other individuals.The predictable physical and chemical substance consequences of death are usually the most reliable PMI indicators, which means shrewd what an insect should look like at which developmental level to determine when a dead body became a corpse (Henssge et al. 1995). PMI is also associated with the epoch rate of various insects which is a nonher tool that is used to determine the time of death of a corpse. The ecological succession rate includes information about the time elapsed among death and the presence of a particular arthropod or insect species and stage (Byrd and Castner, 2010).A dead body will go through very recognizable decomposition stages (physical, biological, and chemical changes) that attract various types of arthropods in each decomposition stage that are needed to determine the succession rate (Monthei, 2009). The most common succession rate estimated by an investigator is the age of larvae and the time interval between death and the arrival of larvae on the corpse (Byrd and Castner, 2010). The knowledge of what insects are supposed to be present and scatterbrained based on the season also helps to determine PMI.Calculation of PMI involves five diametrical arthropod life st ages (eggs, larvae, pupae, adult, and carcass) for flies when collecting insects from corpses. The egg stage of the fly is characterized by the laying of between 150-200 eggs, with the exception of some flies lying between 2000-3000 eggs, found on the body in cluster form indoors areas that provide protection, moisture, and food (Gennard, 2007). Fly eggs are typically calendered and white the eggs have a similar appearance to that of a grain of rice.The reason for specialized placement of eggs on a decomposing body is the fact that the body contains a mettlesome quality of nutrients which are used as a feeding source for the fly eggs to grow, as well as the influence of addition on other species of insects that feed on the decomposing body. The larval stage of the fly species is characterized into trinity stages (L1, L2, and L3) which condition to the number of slits present on the backs of the larvae (Gennard, 2007). These slits are used by entomologists to determine what st age of life the larvae are in when collected.In the third larval stage, where larvae are the largest, the larvae stop feeding on the corpse and begin looking for a place to begin pupariation. Pupariation is the final stage of development in metamorphosis into the adult stage and is generally called the larval post-feeding stage (Gennard, 2007). Pupariation typically doesnt take place on the corpse because insects in this stage prefer to be in a cool, dark place or underground, if possible. In some instances of fly larvae in pupariation, the insects were shown to pupate on the corpse.The adult stage, or the end of the life cycle, is initiated by the arthropod pushing itself out of the puparium case and once the adult fly is free from the puparium case, the insects make their journey upward through the soil. Once the adult fly has reached the top of the soil the insects release their bungle and expand their wings to make their way to other corpses or decomposing material. The adult stage whitethorn be the final stage of the life cycle but the carcass of these adult flies can also be collected as evidence along will the carcasses of arthropods in each life stage.Entomotoxicology Entomotoxicology is the analysis of insects and insect remains for the presence of toxins that may have been present in the corpse before death (Goff and Lord, 1994). Detection of various toxins and controlled substances in insects found on decomposing human remains has contributed to the determination of both cause and manner of death by determining what times of toxins were present in the corpse before death (Lord 1990, Goff and Lord 1994, Nolte et al. , 1992).Entomotoxicology also serves as an alternative analysis tool to determine the presence of toxins or cause of death when certain specimens arent available for collection, such as human blood or tissues. The toxicological analysis of insect biological materials is conducted in the same manner as the toxicological analysis of huma n biological materials, making cause of death determination more accurate (Definis- Gojanovic, 2007). many different species of arthropods, such as flesh flies and blowflies, are used when conducting an entomotoxicological analysis and these arthropods are used to determine the PMI or time before death.The use of entomotoxicology has many advantages, which includes determination of time before death (PMI) and acknowledgement of suspect, but this analytical tool also has several disadvantages. One disadvantage includes the issue of recording the exact temperature of the insects because if the information is incorrect then the expiry of the PMI will also be incorrect. Another disadvantage of this analytical tool is the fact that it is fairly new in the forensic science knit stitch so if an individual isnt educated on how to use the proficiency then valuable entomological evidence related to the case may be lost.Lastly, if proper collection of entomological evidence isnt conducted p roperly, the detriment of highly important evidence relating to time of death and cause of death could be lost. Cause of death is usually determined by various types of toxins that are detected in the insect after an entomotoxicological analysis was conducted. Issues with use of PMI The determination of PMI can be affected by multiple factors but only two will be discussed in this research marriage proposal which include temperature and grain alcohol. Temperature involves the rise or fall of temperature to such a high or low that affects the growth or succession rate of insects.Air temperature and exposure to sunlight will raise the corpse temperature which will also increase the insect succession rate. Temperature can also be influenced by such weather conditions as rain, sun, snow, and wind which can greatly affect the amount of entomological evidence collected (insects) and the outcome of a legal investigation (Sharanowski et al. , 2008). Alcohol, or grain alcohol, is one of t he oldest abused drugs in the world that is readily available and the most commonly abused drug in Western societies (Stripp, 2007).Ethanol is a product of fermentation due to yeast cells acting on sugars from fruits and grains that produces a clear, volatile liquid that is soluble in water (Stripp, 2007). Once grain alcohol enters the blood stream orally it travels in the blood into other tissues. The ethanol travels to tissues with greater water content because these tissues will receive greater ethanol distribution. The ethanol assimilation will be different in both the corpse and the insects due to the different water amounts found in each species (insects and corpse).The rate at which ethanol is eliminated from the body is another important factor to a forensic entomologist because this can determine the time at which the individual started drinking. The focus of this experiment will involve different concentration levels of ethanol and the effects on the growth rate of the fl y species Sarophagidae (flesh flies). Proposed seek The broad, long-term physical objects that this research paper is focused on determining whether ethanol can affect the growth rate of entomological evidence and how much ethanol can be detected in the insects.This research is also being conducted in an attempt to make a comparison to the other research experiments to see if the results concerning growth rate of insects undefendable to such drugs as morphine or heroin are similar or different to the growth rate results of insects exposed to ethanol. This research paper includes four particularized aims that was accomplished as a way to make the broad objective a more manageable piece that could was easier to manipulate. unique(predicate) aim one included determining whether ethanol could be found in both test fly species after feeding on the ethanol infused holler liver.Specific aim two involved determining which concentrations of ethanol produced the most significant changes in the flies. Specific aim triple involved tracking the growth rate of the fly species that were exposed to the ethanol infused screech livers (test subjects) and those who were not (control). Specific aim four involved observing any change in the growth rate data from the fly species test subjects that were exposed to tercet specific concentrations of ethanol. These specific aims will be used in attendant order as a way of getting closer to answer the broad objective. Experimental Methods OverviewThe research experiment hypothesized there would be significant changes in the growth rate of the fly species when exposed to the ternion specific concentrations of ethanol. The research experiment also predicted that there would be obvious physical changes in the flies when exposed to flush livers infused with specific concentrations of ethanol at different stages of life. The experimental design constructed for this experiment involves the fly species Sarophagidae (flesh flies) feeding on beef livers infused with ethanol over a period of eight to xxi days which is the general life cycle for flesh flies.The three beef livers had varying concentrations of ethanol (25 ug, 50 ug, and 100 ug) injected into them that the flesh flies were exposed to. The control group for the experiment was hand massaged with deionized water as a way to keep liquid consistency amongst the groups. At the end of the experiment, the insects were collected into a test tube and then exposed to GCMS or gas chromatography mass spectrometry in an attempt to determine the presence of ethanol in the test subject (insects). The insects were also analyzed for any type of stunted or heightened growth in regards to a normal fly life cycle.This analytical test was able to show that there was ethanol present in the fly species. Experimental Variables The in unfree variable in this experiment is the specific concentration of ethanol that is distributed amongst the three beef livers. The dependen t variable in this experiment is the growth rate of both species after exposure to ethanol as well as the specific ethanol concentrations. The controlled group was the fly larvae that were not exposed to ethanol. The other controlled variables of this experiment were the 45 degrees Farenheit (temperature) the beef livers were maintained at and the amount of beef used (8 oz. as the feeding substrate for the fly species. The experimental groups in this experiment were three larvae groups exposed to ethanol and the control group was a larvae group not exposed to ethanol. Procedures/ Measurements The following experimental design was adapted from a preceding(prenominal) research study conducted by George et al. , 2009. Three beef livers weighing 8 oz. each were prepared using the corresponding ethanol concentrations for the three experimental groups of the fly species tested (Experimental Group Two- 25 ug, Experimental Group Three- 50 ug, and Experimental Group Four- 100 ug). 0 mL of d eionized water was distributed as into the control group (EG 1) to maintain liquid consistency amongst all groups. A cluster of fly larvae for the three experimental groups was collected and distributed evenly amongst the three experimental groups (2-4) as well as the control group. The beef livers were contained in a small plastic tub and refrigerated at a temperature of 45 degrees Farenheit when the beef livers were not being used to discourage fail of beef liver as well as to avoid vapor of ethanol.The growth rate of the test subjects from both fly species exposed to ethanol is measured (any alteration in growth rate is the factor that is being measured) over a period of three weeks. At the end of three weeks, or longer if necessary, all of the perished insects from the experiment were collected for analysis using GCMS (gas chromatography mass spectrometry) to determine the presence or absence of ethanol in the insects. Material List Deionized water Ethanol solution Fly larvae of Sarophagidae (flesh flies)Four beef livers (8 oz. each) Graduated cylinder GCMS machine Microscope Pipette Plastic tubs Refrigerator References Anderson, G. S. (1999). Wildlife rhetorical bugology Determining Time of Death in Two illicitly Killed Black Bear Cubs. ledger of Forensic Sciences, 44(4) 856-859 Anderson, G. S. and Van Laerhoven, S. L. (1996). Initial Studies on Insects Succession on Carrion in Southwestern British Columbia. Journal of Forensic Sciences, 41 617-625 Brown, G. , Fuke, C. , Pounder, D. J. , Robertson, L. and Sadler, D. W. (1997). Barbiturates and Analgesics in Calliphora vicina Larvae. Journal of Forensic Sciences, 42(3) 481-485 Byrd, J. H. and Castner, J. L. 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