Matching Items (14)
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- All Subjects: Forensics
- All Subjects: Urbanization
- Creators: School of Mathematical and Natural Sciences
Description
Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities. Herbivores, for example, are expected to be more abundant in urban desert remnant parks located within cities due to anthropogenic activities that concentrate food resources and reduce native predator populations. Despite this assumption, previous research conducted around Phoenix has shown that top-down herbivory led to equally reduced plant biomass. It is unclear if this insignificant difference in herbivory at rural and urban sites is due to unaltered desert herbivore populations or altered activity levels that counteract abundance differences. Vertebrate herbivore populations were surveyed at four sites inside and four sites outside of the core of Phoenix during fall 2014 and spring 2015 in order to determine whether abundances and richness differ significantly between urban and rural sites. In order to survey species composition and abundance at these sites, 100 Sherman traps and 8 larger wire traps that are designed to attract and capture small vertebrates such as mice, rats, and squirrels, were set at each site for two consecutive trap nights. Results suggest that the commonly assumed effect of urbanization on herbivore abundances does not apply to small rodent herbivore populations in a desert city, as overall small rodent abundances were statistically similar regardless of location. Though a significant difference was not found for species richness, a significant difference between small rodent genera richness at these sites was observed.
ContributorsAlvarez Guevara, Jessica Noemi (Co-author) / Ball, Becky A. (Co-author, Thesis director) / Hall, Sharon J. (Co-author) / Bateman, Heather (Committee member) / School of Sustainability (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Bloodstain pattern analysis can provide telling evidence from a crime scene based on the clues left in the blood, but the field itself is highly problematic since the evidence extracted is dependent upon the interpretation of the analyst. Although some aspects of this type of analysis have been scientifically supported, most are not seen as positively accurate. Since certainty is the basis for acceptance of courtroom testimony, it is important that these unsettled aspects become more understood. This experiment examines the diameter of a weapon and how it affects its cast-off pattern. Weapons with four different diameters were used to generate 5 sample patterns under controlled conditions from each weapon diameter for a total of 20 patterns consisting of 3,367 droplets. The length and width of the pattern, the total number of droplets in the pattern, and the percentage of each droplet type (classified into low-velocity, medium-velocity, and high-velocity droplets) were recorded, averaged, and compared to each other individually using a t-test difference of two means assuming unequal variances. The results reveal that a higher percentage of droplets greater than 4 mm may indicate the use of a weapon with a wider diameter. The data also shows differences between the weapons that may be related to other factors besides the diameter of the weapon such as surface area or the curvature of the weapon. Still, more testing must be conducted to support these theories.
ContributorsBetz, Alexandra Marie (Author) / Kobojek, Kimberly (Thesis director) / Jacobson, David (Committee member) / School of Humanities, Arts, and Cultural Studies (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
In recent years, ecologists have begun to study the effects of urbanization on species diversity. While urban areas generally suffer decreased biodiversity, some species, termed “urban exploiters”, not only live in the city but depend on urban resources to thrive. It is hypothesized that urban exploiters may succeed in part due to phenotypic plasticity, in which organisms rapidly adjust their physiology or behavior to adapt to novel environmental contexts. In the city, it may be adaptive to display thermal plasticity, as the urban heat island effect caused by concrete and asphalt infrastructure prevents cooling at night. In this study, we observed the decorated cricket Gryllodes sigillatus, an invasive urban exploiter found in metropolitan Phoenix, in two separate experiments. We hypothesized that heat tolerance and activity are both plastic traits in this species. In Experiment 1, we predicted that knock-down time, a measure of heat tolerance, would be negatively affected by acclimation to a laboratory environment. Our results suggest that heat tolerance is affected by recent thermal regimes and that laboratory acclimation decreases knock-down time. In Experiment 2, we predicted that activity would increase with temperature until a point of extreme heat, at which point activity would decline. Statistical analysis for the second experiment reveals that activity decreases at 33°C, a natural urban extreme. This suggests either that 33°C is a thermal limit to physiology or that G. sigillatus is able to alter its behavior to exploit local thermal heterogeneity.
ContributorsVannan, Annika (Author) / Johnson, James Chadwick (Thesis director) / Angilletta, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor) / School of Social and Behavioral Sciences (Contributor)
Created2015-05
Description
Urbanization exposes wildlife to many unfamiliar environmental conditions, including the presence of novel structures and food sources. Adapting to or thriving within such anthropogenic modifications may involve cognitive skills, whereby animals come to solve novel problems while navigating, foraging, etc. The increased presence of humans in urban areas is an additional environmental challenge that may potentially impact cognitive performance in wildlife. To date, there has been little experimental investigation into how human disturbance affects problem solving in animals from urban and rural areas. Urban animals may show superior cognitive performance in the face of human disturbance, due to familiarity with benign human presence, or rural animals may show greater cognitive performance in response to the heightened stress of unfamiliar human presence. Here, I studied the relationship between human disturbance, urbanization, and the ability to solve a novel foraging problem in wild-caught juvenile house finches (Haemorhous mexicanus). This songbird is a successful urban dweller and native to the deserts of the southwestern United States. In captivity, finches captured from both urban and rural populations were presented with a novel foraging task (sliding a lid covering their typical food dish) and then exposed to regular periods of high or low human disturbance over several weeks before they were again presented with the task. I found that rural birds exposed to frequent human disturbance showed reduced task performance compared to human-disturbed urban finches. This result is consistent with the hypothesis that acclimation to human presence protects urban birds from reduced cognition, unlike rural birds. Some behaviors related to solving the problem (e.g. pecking at and eying the dish) also differed between urban and rural finches, possibly indicating that urban birds were less neophobic and more exploratory than rural ones. However, these results were unclear. Overall, these findings suggest that urbanization and acclimation to human presence can strongly predict avian response to novelty and cognitive challenges.
ContributorsCook, Meghan Olivia (Author) / McGraw, Kevin (Thesis director) / Bimonte-Nelson, Heather (Committee member) / Weaver, Melinda (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Self-maintenance behaviors, like preening in birds, can have important effects on fitness in many animals. Birds produce preen oil, which is a mixture of volatile and non-volatile compounds, that is spread through their feathers during grooming and influences feather integrity, waterproofing, and coloration. As urban areas grow and present conditions that may demand increased feather self-maintenance (e.g. due to soiling, pollution, elevated UV exposure due to natural habitat alterations), it is important to examine how preening and preen oil may be affected by this process. I assessed variation in preen oil composition in house finches (Haemorhous mexicanus) as a function of sex, urbanization, and plumage hue, a sexually selected indicator of male quality. Preen oil samples from birds captured at urban and rural sites were analyzed using gas chromatography-mass spectrometry. We detected 18 major peaks, which we tentatively identified as esters, and found that, although there were no sex or urban-rural differences in preen oil constituents, there was a significant interactive effect of sex and urbanization, with rural females and urban males having higher amounts of some components. This suggests that factors that vary with sex or urbanization, such as the timing of seasonal cycles, are affecting preen oil composition. There were no significant relationships between coloration and preen oil composition, suggesting that preen oil composition does not vary with male quality.
ContributorsBrooks, Ellen Elizabeth (Author) / McGraw, Kevin (Thesis director) / Liebig, Juergen (Committee member) / Weaver, Melinda (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Abstract Latent fingerprints are a critical component of the evidence that is captured and analyzed from crime scenes and presented for convictions in court. Although fingerprint science has been used for many years in forensics, it is not without many criticisms and critiques from those that believe it is too subjective. Researchers from many disciplines have tried to refute this claim by completing experiments that would eventually lead to a fingerprint aging technique as well as providing statistical models and mathematical support. In this literature review, the research that has been widely published and talked about in this field was reviewed and analyzed to determine what aspects of the experiments are benefitting the study of degradation. By carefully combing through the methods and results of each study, it can be determined where future focuses should be and what disciplines need to be exploited for knowledge. Lastly, an important aspect of the experiments in recent years have depended on the collaboration with statistics so this evidence was examined to identify what models are realistic in determining error rates and likelihood ratios to support latent fingerprint evidence in court. After a thorough review, it is seen that although large strides have been taken to study the degradation of fingerprints, the day where fingerprints will be able to be definitively aged may be ways away. The current experiments have provided methods such as three-dimensional and visual parameters that could potentially find the solution, but also uncovered methods such as immunolabeling and chemical composition that face major challenges. From the statistically point of view, researchers are very close in developing equations that exploit the likelihood ratios of similarity and even calculate the various possible error rates. The evidence found in this review shows that science is one step closer to the age determination of fingerprints.
ContributorsPorter, Lindsey Jordan (Author) / De Alcaraz Fossoul, Josep (Thesis director) / Mancenido, Michelle (Committee member) / School of Criminology and Criminal Justice (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The spread of urbanization leads to habitat fragmentation and deterioration and changes the composition of ecosystems for species all over the world. Different groups of organisms are impacted differently, and insects have experienced loss in diversity and abundance due to changing environmental factors. Here, I collected seed beetles across 12 urban and rural sites in Phoenix, Arizona, to analyze the effects of urbanization and habitat variation on beetle diversity and abundance. I found that urbanization, host tree origin, and environmental factors such as tree diversity and density had no impact on overall beetle diversity and abundance. Beetles were found to have higher density on hosts with a higher density of pods. In assessing individual beetle species, some beetles exhibited higher density in rural sites with native trees, and some were found more commonly on nonnative tree species. The observed differences in beetle density demonstrate the range of effects urbanization and environmental features can have on insect species. By studying ecosystem interactions alongside changing environments, we can better predict the role urbanization and human development can have on different organisms.
ContributorsPaduano, Gabrielle (Author) / Savalli, Udo (Thesis director) / Sweat, Ken (Committee member) / Division of Teacher Preparation (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
As human beings we go through the world interpreting – seeing a situation, gathering context, and making a decision on the meaning of the thing we just experienced. The philosopher Martin Heidegger calls this way of being hermeneutics – a practice of interpretation. This method of approach does not ignore a person’s bias, instead bias is highlighted, understood, and possibly even overcome. In the following pages the basic definition and process of hermeneutics will be discussed. Leading into the difference between calculative and meditative thought – scientific and philosophical – in order to later discuss the possibility and need to merge the two in the field of Forensic Science. Forensic Scientist uses hermeneutic thought by way of merging calculative and meditative thinking. In order to support this claim artistic renderings of ‘the pieces of an unknowable whole’ were created to literally illustrate this truth.
Forensic science is tasked with using calculative thinking with scientifically accepted methods of measurement and detection as well as the meditative task of applying their data to messy, real-world events. In order to support my supposition of forensic scientists being hermeneutical workers, three paintings were created. The three paintings can be considered a tryptic of sorts due to the context in which they are presented: forensic science. They each tell a story that is weaved within each other – spatter indicating violence long past, the empty void of a body gone, and the cold decomposition of a victim found. It is the forensic scientist that must interpret each piece separately and is tasked with finding how and why they are put together. The hermeneutical work of the forensic scientist interpreting a crime scene uses the same methods as one who interprets text. A forensic scientist opens possibilities of meaning in the same way that Martin Heidegger’s hermeneutic circle does. There is interplay between the interpreter (the forensic scientist) and the text (the crime scene), questions are formed (what happened here?) and responses are made (evidence found at the scene). This question and response outlook is what make the forensic scientist a hermeneutic thinker.
Forensic science is tasked with using calculative thinking with scientifically accepted methods of measurement and detection as well as the meditative task of applying their data to messy, real-world events. In order to support my supposition of forensic scientists being hermeneutical workers, three paintings were created. The three paintings can be considered a tryptic of sorts due to the context in which they are presented: forensic science. They each tell a story that is weaved within each other – spatter indicating violence long past, the empty void of a body gone, and the cold decomposition of a victim found. It is the forensic scientist that must interpret each piece separately and is tasked with finding how and why they are put together. The hermeneutical work of the forensic scientist interpreting a crime scene uses the same methods as one who interprets text. A forensic scientist opens possibilities of meaning in the same way that Martin Heidegger’s hermeneutic circle does. There is interplay between the interpreter (the forensic scientist) and the text (the crime scene), questions are formed (what happened here?) and responses are made (evidence found at the scene). This question and response outlook is what make the forensic scientist a hermeneutic thinker.
ContributorsCraig, Catherine Anne (Author) / Kobojek, Kimberly (Thesis director) / Watrous, Lisa (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The effects that forensic-themed programs such as CSI: Crime Scene Investigation has on the public's understanding and expectations of the criminal justice system has been a main focus of study in recent years. This phenomenon was coined by the media and termed the "CSI Effect." This study aimed to research the correlations between age, gender, and program-watching habits on potential juries' evidence expectations in court. To do so, 70 people were surveyed and asked a series of demographic questions, as well as questions about how often they watch forensic-themed shows and their experience with the criminal justice system. They were given a mock crime scene scenario and asked about their scientific and non-scientific evidence expectations in this particular case. The most notable results showed that a longer exposure time to forensic-themed programs correlated to high evidence expectations. However, how often viewers watch forensic-themed programs did not seem to affect their evidence expectations. It was concluded that the higher evidence expectations by modern jurors may be due to a combination of the "CSI Effect" and the newly hypothesized "Tech Effect," instead of just being the consequence of the watching too much forensic-themed television.
ContributorsJones, Kristin Taylor (Author) / Kobojek, Kimberly (Thesis director) / Lafond, Sue (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2014-05
Description
Due to the nature of animals, even domesticated pets, animal scavenging of human remains is an important taphonomic factor. This area of study has, however, been undercounted in the current literature. The purpose of this study was to begin the first step in creating a taphonomic profile for urban / household animal scavenging as distinguishable from manmade tool marks. Using volunteered animals and regularly available tools, alterations were made on beef ribs in order to characterize the distinguishing profiles between the two groups. It was found that animal scavenging alterations, in the short term (20 minutes used in this study) have a distinctly different appearance than tool mark alterations. Animal scavenging has less visible alterations, consistent bite morphology across different species, and symmetrical cut marks along the midsection of the long bones. Ultimately, this study was a successful first step in furthering taphonomic alteration database research across various biomes and conditions.
ContributorsLittle, Cody Lee (Author) / Kobojek, Kimberly (Thesis director) / Falsetti, Anthony (Committee member) / Ball, Becky (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05