Browsing by Subject "patterns"

Now showing 1 - 4 of 4
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    Classes of Intimate Partner Violence From Late Adolescence to Young Adulthood.
    (J Interpers Violence, 2017-06-01) Saint-Eloi Cadely, Hans; Pittman, Joe F; Pettit, Gregory S; Lansford, Jennifer E; Bates, John E; Dodge, Kenneth A; Holtzworth-Munroe, Amy
    Researchers do not agree on how intimate partner violence (IPV) emerges and changes from adolescence to young adulthood. This may be because change in these behaviors varies across individuals. The present study uses a longitudinal, person-centered approach to examine whether there are multiple classes or patterns of change in the perpetration of IPV during the transitional period from adolescence (age 18) to young adulthood (age 25) using data collected annually from a community sample of 484 participants. Latent class analysis was the analytic approach used. Results revealed three patterns for psychological IPV (Little-to-None, Minor/Increasing, and Extensive/Increasing) and two patterns for physical IPV (Little-to-None and Extensive). Patterns varied greatly in number of representatives, although they were more balanced in size for psychological than physical IPV. Variations in IPV behaviors were also revealed across classes, although as expected in a community sample, minor forms of IPV were more common than severe forms. In addition, classes differed in demographic and relationship status variables. These findings suggest that IPV may occur in multiple distinct patterns as opposed to one average pattern across a population. This suggests that interventions for IPV may need to be geared to differences in patterns to enhance their efficacy.
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    Context dependent substitution biases vary within the human genome
    (2010) Nevarez, P Andrew; DeBoever, Christopher M; Freeland, Benjamin J; Quitt, Marissa A; Bush, Eliot C
    Background: Models of sequence evolution typically assume that different nucleotide positions evolve independently. This assumption is widely appreciated to be an over-simplification. The best known violations involve biases due to adjacent nucleotides. There have also been suggestions that biases exist at larger scales, however this possibility has not been systematically explored. Results: To address this we have developed a method which identifies over-and under-represented substitution patterns and assesses their overall impact on the evolution of genome composition. Our method is designed to account for biases at smaller pattern sizes, removing their effects. We used this method to investigate context bias in the human lineage after the divergence from chimpanzee. We examined bias effects in substitution patterns between 2 and 5 bp long and found significant effects at all sizes. This included some individual three and four base pair patterns with relatively large biases. We also found that bias effects vary across the genome, differing between transposons and non-transposons, between different classes of transposons, and also near and far from genes. Conclusions: We found that nucleotides beyond the immediately adjacent one are responsible for substantial context effects, and that these biases vary across the genome.
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    Heading Down the Wrong Pathway: on the Influence of Correlation within Gene Sets
    (2010) Gatti, Daniel M; Barry, William T; Nobel, Andrew B; Rusyn, Ivan; Wright, Fred A
    Background: Analysis of microarray experiments often involves testing for the overrepresentation of pre-defined sets of genes among lists of genes deemed individually significant. Most popular gene set testing methods assume the independence of genes within each set, an assumption that is seriously violated, as extensive correlation between genes is a well-documented phenomenon. Results: We conducted a meta-analysis of over 200 datasets from the Gene Expression Omnibus in order to demonstrate the practical impact of strong gene correlation patterns that are highly consistent across experiments. We show that a common independence assumption-based gene set testing procedure produces very high false positive rates when applied to data sets for which treatment groups have been randomized, and that gene sets with high internal correlation are more likely to be declared significant. A reanalysis of the same datasets using an array resampling approach properly controls false positive rates, leading to more parsimonious and high-confidence gene set findings, which should facilitate pathway-based interpretation of the microarray data. Conclusions: These findings call into question many of the gene set testing results in the literature and argue strongly for the adoption of resampling based gene set testing criteria in the peer reviewed biomedical literature.
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    Representation of Global and National Conservation Priorities by Colombia's Protected Area Network
    (2010) Forero-Medina, German; Joppa, Lucas
    Background: How do national-level actions overlap with global priorities for conservation? Answering this question is especially important in countries with high and unique biological diversity like Colombia. Global biodiversity schemes provide conservation guidance at a large scale, while national governments gazette land for protection based on a combination of criteria at regional or local scales. Information on how a protected area network represents global and national conservation priorities is crucial for finding gaps in coverage and for future expansion of the system. Methodology/Principal Findings: We evaluated the agreement of Colombia's protected area network with global conservation priorities, and the extent to which the network reflects the country's biomes, species richness, and common environmental and physical conditions. We used this information to identify priority biomes for conservation. We find the dominant strategy in Colombia has been a proactive one, allocating the highest proportion of protected land on intact, difficult to access and species rich areas like the Amazon. Threatened and unique areas are disproportionately absent from Colombia's protected lands. We highlight six biomes in Colombia as conservation priorities that should be considered in any future expansion of Colombia's protected area network. Two of these biomes have less than 3% of their area protected and more than 70% of their area transformed for human use. One has less than 3% protected and high numbers of threatened vertebrates. Three biomes fall in both categories. Conclusions: Expansion of Colombia's Protected Area Network should consider the current representativeness of the network. We indicate six priority biomes that can contribute to improving the representation of threatened species and biomes in Colombia.