669 research outputs found
The Effect of Prenatal Valproate Exposure in Serotonin Transporter Knockout Rats On Anxiety and Cognition: A Gene*Environment Interaction Model of Autism Spectrum Disorder
Autism Spectrum Disorder is a complex neurodevelopmental disorder which is often associated with increased anxiety and deficits in cognitive ability. The present research investigated a potential gene*environment interaction between two factors previously implicated in ASD in a rat model; prenatal exposure to valproate (VPA) and genetic reduction of the serotonin transporter (SERT). Wildtype and heterozygous SERT knockout rats prenatally exposed to VPA or saline on gestational day12.5 (G12.5) were assessed on measures of anxiety: elevated plus-maze and novelty suppressed-feeding and cognitive ability: prepulse inhibition and latent inhibition. A significant main effect was found for VPA exposure in all paradigms, showing increased anxiety-typical behaviour and abnormal cognitive ability. However, no significant effect of genotype or interaction was observed. Results from the present study do not confirm gene*environment interaction between prenatal VPA and heterozygous SERT knockout but this may be due to several factors that are discussed within the thesis. In any case, this study represents a starting point for further studies investigating other combinations of genetic and environmental factors as models of ASD pathogenesis
Ruination
My work is an investigation of illegal dumpsites located in the Blue Ridge area. This body of work serves as a timeline of the impact on the local landscape. Using photography, printmaking, and sculpture, I explore the environmental impact of the dumpsites, the accumulations of trash it creates, and the reclamation by nature. I seek to bring the global concern of trash into a local perspective
Diversity, Collaboration, Reflective Practice, and Technology in Professional Education Programs: Strategic Choices for Higher Education
Today\u27s postsecondary students are entering American institutions of higher education (IHEs) with different experiences, expectations, and learning needs than students of previous generations. Calls for more diverse campuses, advanced technology, and lifelong learning are maintaining pressure on IHEs to adjust to new demands for a more encompassing vision as traditional approaches are no longer adequate. The challenges are tremendous; the responses must be extensive and reflective if higher education is to achieve its goals of preparing students for productive and meaningful lives. This study investigated student experiences in a yearlong professional education program that was focused by four strategic choices identified by a college of education in a large southwestern university: diversity, collaboration, reflective practice, and technology. Specifically, the content of student journals and transcripts of group discussions were analyzed for indications of changes in awareness and examples of application during their internship experiences. Qualitative research methods were used to address the following questions: 1) How, if at all, did the students, awareness of the four strategic choices change over time? and 2) How, if at all, did the students apply the four strategic choices during their internships? Data were analyzed using a modified version of the constant comparative approach of developing theory. Three subprocesses, e.g., data reduction, data display, and conclusion drawing/verification, were employed to identify patterns of attitude change over time, and indications of progress through stages of awareness, understanding, and application. As patterns emerged, new relationships and explanations were discovered. Findings indicated that changes in awareness occurred and that students applied what they learned in their internships. This study demonstrated that infusing strategic choices into the coursework of a professional education program helped encourage students to challenge their own beliefs and clarify their own values. In addition, the use of a cohort structure and seminar class facilitated the creation and maintenance of a learning community. Finally, coordinating the goals and activities of the coursework and internship experiences helped to reinforce effective models for teaching and learning. Based on these findings, implications were offered for professional education programs and for administrators and faculty engaged in IHE reform
Restriction Fragment Length Polymorphism Linkage Map for Arabidopsis thaliana
We have constructed a restriction fragment length polymorphism linkage map for the nuclear genome of the flowering plant Arabidopsis thaliana. The map, containing 90 randomly distributed molecular markers, is physically very dense; >50% of the genome is within 1.9 centimorgans, or approx 270 kilobase pairs, of the mapped DNA fragments. The map was based on the meiotic segregation of markers in two different crosses. The restriction fragment length polymorphism linkage groups were integrated with the five classically mapped linkage groups by virtue of mapped mutations included in these crosses. Markers consist of both cloned Arabidopsis genes and random low-copy-number genomic DNA clones that are able to detect polymorphisms with the restriction enzymes EcoRI, Bgl II, and/or Xba I. These cloned markers can serve as starting points for chromosome walking, allowing for the isolation of Arabidopsis genes of known map location. The restriction fragment length polymorphism map also can associate clones of unknown gene function with mutant phenotypes, and vice versa
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Estimating the proportion of guilty suspects and posterior probability of guilt in lineups using signal-detection models
Background
The majority of eyewitness lineup studies are laboratory-based. How well the conclusions of these studies, including the relationship between confidence and accuracy, generalize to real-world police lineups is an open question. Signal detection theory (SDT) has emerged as a powerful framework for analyzing lineups that allows comparison of witnessesâ memory accuracy under different types of identification procedures. Because the guilt or innocence of a real-world suspect is generally not known, however, it is further unknown precisely how the identification of a suspect should change our belief in their guilt. The probability of guilt after the suspect has been identified, the posterior probability of guilt (PPG), can only be meaningfully estimated if we know the proportion of lineups that include a guilty suspect, P(guilty). Recent work used SDT to estimate P(guilty) on a single empirical data set that shared an important property with real-world data; that is, no information about the guilt or innocence of the suspects was provided. Here we test the ability of the SDT model to recover P(guilty) on a wide range of pre-existing empirical data from more than 10,000 identification decisions. We then use simulations of the SDT model to determine the conditions under which the model succeeds and, where applicable, why it fails. Results
For both empirical and simulated studies, the model was able to accurately estimate P(guilty) when the lineups were fair (the guilty and innocent suspects did not stand out) and identifications of both suspects and fillers occurred with a range of confidence levels. Simulations showed that the model can accurately recover P(guilty) given data that matches the model assumptions. The model failed to accurately estimate P(guilty) under conditions that violated its assumptions; for example, when the effective size of the lineup was reduced, either because the fillers were selected to be poor matches to the suspect or because the innocent suspect was more familiar than the guilty suspect. The model also underestimated P(guilty) when a weapon was shown. Conclusions
Depending on lineup quality, estimation of P(guilty) and, relatedly, PPG, from the SDT model can range from poor to excellent. These results highlight the need to carefully consider how the similarity relations between fillers and suspects influence identifications
BDNF Val 66 Met genotype is associated with drugâseeking phenotypes in heroinâdependent individuals: a pilot study
Brainâderived neurotrophic factor (BDNF) Val 66 Met genotype has been associated with neurobehavioral deficits. To examine its relevance for addiction, we examined BDNF genotype differences in drugâseeking behavior. Heroinâdependent volunteers ( n â=â128) completed an interview that assessed pastâmonth naturalistic drugâseeking/use behaviors. In African Americans ( n â=â74), the Met allele was uncommon (carrier frequency 6.8%); thus, analyses focused on European Americans ( n â=â54), in whom the Met allele was common (carrier frequency 37.0%). In their natural setting, Met carriers ( n â=â20) reported more timeâ and costâintensive heroinâseeking and more cigarette use than Val homozygotes ( n â=â34). BDNF Val 66 Met genotype predicted 18.4% of variance in âweekly heroin investmentâ (purchasing timeâĂâamountâĂâfrequency). These data suggest that the BDNF Met allele may confer a âpreferred drugâinvestedâ phenotype, resistant to moderating effects of higher drug prices and nonâdrug reinforcement. These preliminary hypothesisâgenerating findings require replication, but are consistent with preâclinical data that demonstrate neurotrophic influence in drug reinforcement. Whether this genotype is relevant to other abused substances besides opioids or nicotine, or treatment response, remains to be determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99593/1/adb431.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99593/2/adb431_sm_fig_s1.pd
Genome-Wide Interaction Study of Omega-3 PUFAs and Other Fatty Acids on Inflammatory Biomarkers of Cardiovascular Health in the Framingham Heart Study
Numerous genetic loci have been identified as being associated with circulating fatty acid (FA) levels and/or inflammatory biomarkers of cardiovascular health (e.g., C-reactive protein). Recently, using red blood cell (RBC) FA data from the Framingham Offspring Study, we conducted a genome-wide association study of over 2.5 million single nucleotide polymorphisms (SNPs) and 22 RBC FAs (and associated ratios), including the four Omega-3 FAs (ALA, DHA, DPA, and EPA). Our analyses identified numerous causal loci. In this manuscript, we investigate the extent to which polyunsaturated fatty acid (PUFA) levels moderate the relationship of genetics to cardiovascular health biomarkers using a genome-wide interaction study approach. In particular, we test for possible geneâFA interactions on 9 inflammatory biomarkers, with 2.5 million SNPs and 12 FAs, including all Omega-3 PUFAs. We identified eighteen novel loci, including loci which demonstrate strong evidence of modifying the impact of heritable genetics on biomarker levels, and subsequently cardiovascular health. The identified genes provide increased clarity on the biological functioning and role of Omega-3 PUFAs, as well as other common fatty acids, in cardiovascular health, and suggest numerous candidate loci for future replication and biological characterization
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