439 research outputs found
Assessing Visual Preference among Fourth Grade Students for Habitat Components on Educational Green Roofs in Starkville, Mississippi
As urbanization grows wildlife habitat is displaced and fragmented. Vegetative roofs offer an innovative alternative to provide animal food and habitat in urban environments. This research study investigates how wildlife needs in a green roof ecosystem are interpreted through childrenās visual perception. A visual preference survey was administered to fourth-grade students in Starkville, Mississippi which offered paired photographs displaying basic vertebrate and invertebrate needs. The responses from 85 students (n=85) were compared to identify preferences for legible habitat components. The results of this survey showed that fourth-grade students could readily identify the basic habitat needs for birds but were less able to with insects. Students were intrigued with utilizing a green roof for learning and play. Green roofs have potential to be designed as innovative teaching tools to enhance science education in K-12 schools
Deliberate self-harm in clinical and non-clinical populations
Approximately 4% of the general population and 14% of college students have engaged or currently engage in deliberate self-harm. The purpose of the Literature Review is to assess similarities and differences of demographic information, gender, age, frequency, prevalence rates, methods, and reasons of self-harm in both clinical and non-clinical samples. Definitions and alternate names of self-harm were presented, common misconceptions regarding gender were discussed, and frequency and prevalence rates in clinical and non-clinical samples were compared
Course Placement, Course Modality, and Student Success: Developmental Mathematics at a Public Two-Year College in the Northeast
Changing how we present information to students has been standard discourse from as early as the 5th century BC, when Quintilian stated that teachers needed to reach students with different learning styles at different points in their education (Corno, 2008). There are varied methods for reaching students with learning disabilities, language or cultural differences, and content-related struggles, but no singular method has proven to be the ābestā choice for all learners. This research study examined archival data of developmental mathematics students from fall 2015 through spring 2019 at Northampton Community College (N.C.C.).
Purpose
The purposes of this journal-ready dissertation were to look for differences in student success and persistence in developmental mathematics based on three factors: placement, studentsā perceptions of their motivation and anxiety, and the course modality they chose. The first purpose was to analyze the success and persistence of students in mathematics, based on the collegeās placement policy of utilizing high school transcripts and ACCUPLACER exam. The second purpose was to determine if developmental studentsā perceptions of their motivation and anxiety levels impacted their final course grade or persistence in mathematics at the college. Finally, the third purpose was to examine the differences between final exam grades, final course grades, and persistence to the next mathematics courses at the college, based on developmental mathematics course modality. The first and third research study involved an analysis of four years of data from a suburban community college in Northeastern Pennsylvania. The second study involved the survey of developmental mathematics students in the spring of 2019.
Method
This study was a causal-comparative research design using archival data from Northampton Community College Institutional Review Board for fall 2015 through spring 2019 school years. Statistical data were analyzed to determine whether differences existed in final exams, final course grades, persistence in mathematics, and motivation and anxiety levels for students enrolled in developmental mathematics in either emporium, face-to-face, or online courses during this timeframe.
Findings
In the first study, chi-square analysis revealed that placement by high school transcripts appeared to result in higher success and persistence in mathematics for students. The second study examined how studentsā perceptions of their intrinsic and extrinsic motivation and anxiety levels affected their course grades in these courses, based on their modality using MANOVA and t-test analysis. Regardless of student success or course modality, students who responded to the survey were more worried and extrinsically motivated than had negative affection reactions (NAR) or were intrinsically motivated. In the third study, chi-square analysis revealed that, overall, students in emporium and face-to-face courses performed equally as well, but online students struggled more with final course grades and persistence in mathematics at the college. The conclusion of this journal-style dissertation includes connections with literature and theoretical frameworks and suggestions for practice and future research
PARE: A tool for comparing protein abundance and mRNA expression data
<p>Abstract</p> <p>Background</p> <p>Techniques for measuring protein abundance are rapidly advancing and we are now in a situation where we anticipate many protein abundance data sets will be available in the near future. Since proteins are translated from mRNAs, their expression is expected to be related to their abundance, to some degree.</p> <p>Results</p> <p>We have developed a web tool, called PARE (Protein Abundance and mRNA Expression; <url>http://proteomics.gersteinlab.org</url>), to correlate these two quantities. In addition to globally comparing the quantities of protein and mRNA, PARE allows users to select subsets of proteins for focused study (based on functional categories and complexes). Furthermore, it highlights correlation outliers, which are potentially worth further examination.</p> <p>Conclusion</p> <p>We anticipate PARE will facilitate comparative studies on mRNA and protein abundance by the proteomics community.</p
The Genetics of Speciation by Reinforcement
Reinforcement occurs when natural selection strengthens behavioral discrimination to prevent costly interspecies matings, such as when matings produce sterile hybrids. This evolutionary process can complete speciation, thereby providing a direct link between Darwin's theory of natural selection and the origin of new species. Here, by examining a case of speciation by reinforcement in Drosophila, we present the first high-resolution genetic study of variation within species for female mating discrimination that is enhanced by natural selection. We show that reinforced mating discrimination is inherited as a dominant trait, exhibits variability within species, and may be influenced by a known set of candidate genes involved in olfaction. Our results show that the genetics of reinforced mating discrimination is different from the genetics of mating discrimination between species, suggesting that overall mating discrimination might be a composite phenomenon, which in Drosophila could involve both auditory and olfactory cues. Examining the genetics of reinforcement provides a unique opportunity for both understanding the origin of new species in the face of gene flow and identifying the genetic basis of adaptive female species preferences, two major gaps in our understanding of speciation
Divergence with gene flow across a speciation continuum of Heliconius butterflies
BACKGROUND:
A key to understanding the origins of species is determining the evolutionary processes that drive the patterns of genomic divergence during speciation. New genomic technologies enable the study of high-resolution genomic patterns of divergence across natural speciation continua, where taxa pairs with different levels of reproductive isolation can be used as proxies for different stages of speciation. Empirical studies of these speciation continua can provide valuable insights into how genomes diverge during speciation.
METHODS:
We examine variation across a handful of genomic regions in parapatric and allopatric populations of Heliconius butterflies with varying levels of reproductive isolation. Genome sequences were mapped to 2.2-Mb of the H. erato genome, including 1-Mb across the red color pattern locus and multiple regions unlinked to color pattern variation.
RESULTS:
Phylogenetic analyses reveal a speciation continuum of pairs of hybridizing races and incipient species in the Heliconius erato clade. Comparisons of hybridizing pairs of divergently colored races and incipient species reveal that genomic divergence increases with ecological and reproductive isolation, not only across the locus responsible for adaptive variation in red wing coloration, but also at genomic regions unlinked to color pattern.
DISCUSSION:
We observe high levels of divergence between the incipient species H. erato and H. himera, suggesting that divergence may accumulate early in the speciation process. Comparisons of genomic divergence between the incipient species and allopatric races suggest that limited gene flow cannot account for the observed high levels of divergence between the incipient species.
CONCLUSIONS:
Our results provide a reconstruction of the speciation continuum across the H. erato clade and provide insights into the processes that drive genomic divergence during speciation, establishing the H. erato clade as a powerful framework for the study of speciation.This work was funded by the following awards: Hanne and Torkel Weis-Fogh
Fund (sample collection, awarded to Nicola Nadeau and Richard Merrill);
CNRS Nouraugues (BAC); NSF DEB-1257839 (BAC), DEB-1257689 (WOM), DEB-
1027019 (WOM); and the Smithsonian Institution
Transposable element evolution in Heliconius suggests genome diversity within Lepidoptera
Background Transposable elements (TEs) have the potential to impact genome structure, function and evolution in profound ways. In order to understand the contribution of transposable elements (TEs) to Heliconius melpomene, we queried the H. melpomene draft sequence to identify repetitive sequences. Results We determined that TEs comprise ~25% of the genome. The predominant class of TEs (~12% of the genome) was the non-long terminal repeat (non-LTR) retrotransposons, including a novel SINE family. However, this was only slightly higher than content derived from DNA transposons, which are diverse, with several families having mobilized in the recent past. Compared to the only other well-studied lepidopteran genome, Bombyx mori, H. melpomene exhibits a higher DNA transposon content and a distinct repertoire of retrotransposons. We also found that H. melpomene exhibits a high rate of TE turnover with few older elements accumulating in the genome. Conclusions Our analysis represents the first complete, de novo characterization of TE content in a butterfly genome and suggests that, while TEs are able to invade and multiply, TEs have an overall deleterious effect and/or that maintaining a small genome is advantageous. Our results also hint that analysis of additional lepidopteran genomes will reveal substantial TE diversity within the group
Patternize: An R Package For Quantifying Color Pattern Variation
The use of image data to quantify, study and compare variation in the colors and patterns of organisms requires the alignment of images to establish homology, followed by color-based segmentation of images. Here we describe an R package for image alignment and segmentation that has applications to quantify color patterns in a wide range of organisms. patternize is an R package that quantifies variation in color patterns obtained from image data. patternize first defines homology between pattern positions across specimens either through manually placed homologous landmarks or automated image registration. Pattern identification is performed by categorizing the distribution of colors using an RGB threshold, k-means clustering or watershed transformation. We demonstrate that patternize can be used for quantification of the color patterns in a variety of organisms by analyzing image data for butterflies, guppies, spiders and salamanders. Image data can be compared between sets of specimens, visualized as heatmaps and analyzed using principal component analysis (PCA). patternize has potential applications for fine scale quantification of color pattern phenotypes in population comparisons, genetic association studies and investigating the basis of color pattern variation across a wide range of organisms.NSF grant DEB-1257839
NIH grant 5P20GM103475-1
X-ray diffraction and computer simulation studies on the structure of homophase and heterophase interfaces in metals
We use the Thin Film X-ray Diffraction (TFXD) technique in conjunction with computer simulation methods to obtain detailed information on the structure of complex interfacial systems in metals. Results for three types of interfaces are presented. These are, a [Sigma] 13 [001] twist homophase boundary in a Au-Cu 10 at. % alloy, a [Sigma] 26/29 [001] twist Au-Pd heterophase boundary and finally the [Sigma] 4/5 [001] twist Ag-Cu heterophase boundary. For the homophase boundary in Au-Cu we demonstrate the utility of the X-ray technique in studying the effects of solute segregation on boundary structure. Calculations predict trends which are in agreement with the experimental observations; however the precise magnitudes of the observed effects are not reproduced by the calculations. For the Au-Pd heterophase boundary semi-quantitative agreement is obtained between the experiments and the calculations (performed using EAM potentials and Molecular Statics). Finally, in the Ag-Cu [Sigma] 4/5 system, strong X-ray scattering is observed on the BDL, and is correlated with surprisingly large atomic displacements in this boundary; fairly good agreement is obtained with computer simulated structures. We conclude with speculations on the usefulness of the simple dislocation model in the Ag-Cu [001] twist system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31311/1/0000220.pd
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