433 research outputs found
Leading a Campus Team to Navigate Through the Comprehensive Evaluation
What are some best practices to help your institution prepare for a comprehensive evaluation? This presentation will include discussion of how to gain broad campus community participation by assembling a team to help lead the process. Committee membership, information sharing, meeting topics and timelines will be shared
Minnesota Tuning Project: Biology and Graphic Design
Within the tuning methodology, a key step is the utilization of a consultative survey. The objectives established in the Bologna process for the tuning survey “include gleaning current perspectives on the diversity of practice and commonality of knowledge across borders and traditions, and seeking a simple and accessible language to create a scaffolding on which the various degrees can work in comfort and trust” (Adelman, 2009, p. 49). The Minnesota tuning surveys sought the consultation of previous graduates, current students, employers of graduates, and academic faculty for each of the disciplines involved in tuning
A genetic algorithm based method for stringent haplotyping of family data
<p>Abstract</p> <p>Background</p> <p>The linkage phase, or haplotype, is an extra level of information that in addition to genotype and pedigree can be useful for reconstructing the inheritance pattern of the alleles in a pedigree, and computing for example Identity By Descent probabilities. If a haplotype is provided, the precision of estimated IBD probabilities increases, as long as the haplotype is estimated without errors. It is therefore important to only use haplotypes that are strongly supported by the available data for IBD estimation, to avoid introducing new errors due to erroneous linkage phases.</p> <p>Results</p> <p>We propose a genetic algorithm based method for haplotype estimation in family data that includes a stringency parameter. This allows the user to decide the error tolerance level when inferring parental origin of the alleles. This is a novel feature compared to existing methods for haplotype estimation. We show that using a high stringency produces haplotype data with few errors, whereas a low stringency provides haplotype estimates in most situations, but with an increased number of errors.</p> <p>Conclusion</p> <p>By including a stringency criterion in our haplotyping method, the user is able to maintain the error rate at a suitable level for the particular study; one can select anything from haplotyped data with very small proportion of errors and a higher proportion of non-inferred haplotypes, to data with phase estimates for every marker, when haplotype errors are tolerable. Giving this choice makes the method more flexible and useful in a wide range of applications as it is able to fulfil different requirements regarding the tolerance for haplotype errors, or uncertain marker-phases.</p
Electromagnetic Reduction of Plasma Density During Atmospheric Reentry and Hypersonic Flights
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76341/1/AIAA-32147-259.pd
Evaluation of Readmission Ink as a Marker for Dispersal Studies with the Oriental Fruit Fly, Bactrocera dorsalis
In this text we present a new marking dye, readmission ink, Blak-Ray, for the purpose of insect movement studies. The dye was tested in a controlled experiment with Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) in anticipation of a long distance movement study planned for the following year with the same species. 700 individuals of both sexes were marked with the dye and placed in holding containers. Both the percentage of mortality and the ease of dye detection were monitored throughout a five-week period. Results showed minimal fly mortality and exceptional ease of dye detection
Evidence for Pervasive Adaptive Protein Evolution in Wild Mice
The relative contributions of neutral and adaptive substitutions to molecular evolution has been one of the most controversial issues in evolutionary biology for more than 40 years. The analysis of within-species nucleotide polymorphism and between-species divergence data supports a widespread role for adaptive protein evolution in certain taxa. For example, estimates of the proportion of adaptive amino acid substitutions (alpha) are 50% or more in enteric bacteria and Drosophila. In contrast, recent estimates of alpha for hominids have been at most 13%. Here, we estimate alpha for protein sequences of murid rodents based on nucleotide polymorphism data from multiple genes in a population of the house mouse subspecies Mus musculus castaneus, which inhabits the ancestral range of the Mus species complex and nucleotide divergence between M. m. castaneus and M. famulus or the rat. We estimate that 57% of amino acid substitutions in murids have been driven by positive selection. Hominids, therefore, are exceptional in having low apparent levels of adaptive protein evolution. The high frequency of adaptive amino acid substitutions in wild mice is consistent with their large effective population size, leading to effective natural selection at the molecular level. Effective natural selection also manifests itself as a paucity of effectively neutral nonsynonymous mutations in M. m. castaneus compared to humans
Parallel Adaptive Divergence among Geographically Diverse Human Populations
Few genetic differences between human populations conform to the classic model of positive selection, in which a newly arisen mutation rapidly approaches fixation in one lineage, suggesting that adaptation more commonly occurs via moderate changes in standing variation at many loci. Detecting and characterizing this type of complex selection requires integrating individually ambiguous signatures across genomically and geographically extensive data. Here, we develop a novel approach to test the hypothesis that selection has favored modest divergence at particular loci multiple times in independent human populations. We find an excess of SNPs showing non-neutral parallel divergence, enriched for genic and nonsynonymous polymorphisms in genes encompassing diverse and often disease related functions. Repeated parallel evolution in the same direction suggests common selective pressures in disparate habitats. We test our method with extensive coalescent simulations and show that it is robust to a wide range of demographic events. Our results demonstrate phylogenetically orthogonal patterns of local adaptation caused by subtle shifts at many widespread polymorphisms that likely underlie substantial phenotypic diversity
Admixture in the Hispanics of the San Luis Valley, Colorado, and its implications for complex trait gene mapping
Hispanic populations are a valuable resource that can and should facilitate the identification of complex trait genes by means of admixture mapping (AM). In this paper we focus on a particular Hispanic population living in the San Luis Valley (SLV) in Southern Colorado.We used a set of 22 Ancestry Informative Markers (AIMs) to describe the admixture process and dynamics in this population. AIMs are defined as genetic markers that exhibit allele frequency differences between parental populations ≥30%, and are more informative for studying admixed populations than random markers. The ancestral proportions of the SLV Hispanic population are estimated as 62.7 ± 2.1% European, 34.1 ± 1.9% Native American and 3.2 ± 1.5% West African. We also estimated the ancestral proportions of individuals using these AIMs. Population structure was demonstrated by the excess association of unlinked markers, the correlation between estimates of admixture based on unlinked marker sets, and by a highly significant correlation between individual Native American ancestry and skin pigmentation (R 2 = 0.082, p < 0.001). We discuss the implications of these findings in disease gene mapping efforts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65937/1/j.1529-8817.2003.00084.x.pd
Empirical Distributions of F-ST from Large-Scale Human Polymorphism Data
Studies of the apportionment of human genetic variation have long established that most human variation is within population groups and that the additional variation between population groups is small but greatest when comparing different continental populations. These studies often used Wright’s FST that apportions the standardized variance in allele frequencies within and between population groups. Because local adaptations increase population differentiation, high-FST may be found at closely linked loci under selection and used to identify genes undergoing directional or heterotic selection. We re-examined these processes using HapMap data. We analyzed 3 million SNPs on 602 samples from eight worldwide populations and a consensus subset of 1 million SNPs found in all populations. We identified four major features of the data: First, a hierarchically FST analysis showed that only a paucity (12%) of the total genetic variation is distributed between continental populations and even a lesser genetic variation (1%) is found between intra-continental populations. Second, the global FST distribution closely follows an exponential distribution. Third, although the overall FST distribution is similarly shaped (inverse J), FST distributions varies markedly by allele frequency when divided into non-overlapping groups by allele frequency range. Because the mean allele frequency is a crude indicator of allele age, these distributions mark the time-dependent change in genetic differentiation. Finally, the change in mean-FST of these groups is linear in allele frequency. These results suggest that investigating the extremes of the FST distribution for each allele frequency group is more efficient for detecting selection. Consequently, we demonstrate that such extreme SNPs are more clustered along the chromosomes than expected from linkage disequilibrium for each allele frequency group. These genomic regions are therefore likely candidates for natural selection
The PLIN4 Variant rs8887 Modulates Obesity Related Phenotypes in Humans through Creation of a Novel miR-522 Seed Site
PLIN4 is a member of the PAT family of lipid storage droplet
(LSD) proteins. Associations between seven single nucleotide polymorphisms
(SNPs) at human PLIN4 with obesity related phenotypes were
investigated using meta-analysis followed by a determination if these phenotypes
are modulated by interactions between PLIN4 SNPs and dietary
PUFA. Samples consisted of subjects from two populations of European ancestry.
We demonstrated association of rs8887 with anthropometrics. Meta-analysis
demonstrated significant interactions between the rs8887 minor allele with PUFA
n3 modulating anthropometrics. rs884164 showed interaction with both n3 and n6
PUFA modulating anthropometric and lipid phenotypes. In silico
analysis of the PLIN4 3′UTR sequence surrounding the
rs8887 minor A allele predicted a seed site for the human microRNA-522
(miR-522), suggesting a functional mechanism. Our data showed that a PLIN4
3′UTR luciferase reporter carrying the A allele of rs8887 was reduced in
response to miR-522 mimics compared to the G allele. These results suggest
variation at the PLIN4 locus, and its interaction with PUFA as
a modulator of obesity related phenotypes, acts in part through creation of a
miR-522 regulatory site
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