Clarity of Microstamped Identifiers as a Function of Primer Hardness and Type of Firearm Action

The transfer of microstamped identifiers to the primers of fired cartridges was examined using a stereomicroscope and scanning electron microscope (SEM). The identifiers were placed on the firing pins of three different 9mm handguns, namely, a Sig Sauer, a Taurus, and a Hi-Point. Ten different brands of ammunition were fired from each handgun, 100 rounds being fired using each brand for a total of 1000 rounds fired per handgun. The quality of the markings was evaluated using a simple observation rubric. These results were compared to Vickers hardness values obtained from the ammunition primers and are discussed in light of the types of actions of firearms used

Evolution of a Sexually Dimorphic Trait In a Broadly Distributed Topminnow (\u3ci\u3eFundulus olivaceus\u3c/i\u3e)

Understanding the interaction between sexual and natural selection within variable environments is crucial to our understanding of evolutionary processes. The handicap principle predicts females will prefer males with exaggerated traits provided those traits are indicators of male quality to ensure direct or indirect female benefits. Spatial variability in ecological factors is expected to alter the balance between sexual and natural selection that defines the evolution of such traits. Male and female blackspotted topminnows (Fundulidae: Fundulus olivaceus) display prominent black dorsolateral spots that are variable in number across its broad range. We investigated variability in spot phenotypes at 117 sites across 13 river systems and asked if the trait was sexually dimorphic and positively correlated with measures of fitness (condition and gonadosomatic index [GSI]). Laboratory and mesocosm experiments assessed femalemate choice and predation pressure on spot phenotypes. Environmental and community data collected at sampling locations were used to assess predictive models of spot density at the individual, site, and river system level. Greater number of spots was positively correlated with measures of fitness in males. Males with more spots were preferred by females and suffered greater mortality due to predation. Water clarity (turbidity) was the best predictor of spot density on the drainage scale, indicating that sexual and natural selection for the trait may be mediated by local light environments

Evolution of a Sexually Dimorphic Trait in a Broadly Distributed Topminnow (Fundulus Olivaceus)

Understanding the interaction between sexual and natural selection within variable environments is crucial to our understanding of evolutionary processes. The handicap principle predicts females will prefer males with exaggerated traits provided those traits are indicators of male quality to ensure direct or indirect female benefits. Spatial variability in ecological factors is expected to alter the balance between sexual and natural selection that defines the evolution of such traits. Male and female blackspotted topminnows (Fundulidae: Fundulus olivaceus) display prominent black dorsolateral spots that are variable in number across its broad range. We investigated variability in spot phenotypes at 117 sites across 13 river systems and asked if the trait was sexually dimorphic and positively correlated with measures of fitness (condition and gonadosomatic index [GSI]). Laboratory and mesocosm experiments assessed female mate choice and predation pressure on spot phenotypes. Environmental and community data collected at sampling locations were used to assess predictive models of spot density at the individual, site, and river system level. Greater number of spots was positively correlated with measures of fitness in males. Males with more spots were preferred by females and suffered greater mortality due to predation. Water clarity (turbidity) was the best predictor of spot density on the drainage scale, indicating that sexual and natural selection for the trait may be mediated by local light environments

A prospective randomised trial comparing nasogastric with intravenous hydration in children with bronchiolitis (protocol) The comparative rehydration in bronchiolitis study (CRIB)

<p>Abstract</p> <p>Background</p> <p>Bronchiolitis is the most common reason for admission of infants to hospital in developed countries. Fluid replacement therapy is required in about 30% of children admitted with bronchiolitis. There are currently two techniques of fluid replacement therapy that are used with the same frequency-intravenous (IV) or nasogastric (NG).</p> <p>The evidence to determine the optimum route of hydration therapy for infants with bronchiolitis is inadequate. This randomised trial will be the first to provide good quality evidence of whether nasogastric rehydration (NGR) offers benefits over intravenous rehydration (IVR) using the clinically relevant continuous outcome measure of duration of hospital admission.</p> <p>Methods/Design</p> <p>A prospective randomised multi-centre trial in Australia and New Zealand where children between 2 and 12 months of age with bronchiolitis, needing non oral fluid replacement, are randomised to receive either intravenous (IV) or nasogastric (NG) rehydration.</p> <p>750 patients admitted to participating hospitals will be recruited, and will be followed daily during the admission and by telephone 1 week after discharge. Patients with chronic respiratory, cardiac, or neurological disease; choanal atresia; needing IV fluid resuscitation; needing an IV for other reasons, and those requiring CPAP or ventilation are excluded.</p> <p>The primary endpoint is duration of hospital admission. Secondary outcomes are complications, need for ICU admission, parental satisfaction, and an economic evaluation. Results will be analysed using t-test for continuous data, and chi squared for categorical data. Non parametric data will be log transformed.</p> <p>Discussion</p> <p>This trial will define the role of NGR and IVR in bronchiolitis</p> <p>Trail registration</p> <p>The trial is registered with the Australian and New Zealand Clinical Trials Registry - ACTRN12605000033640</p

Validation of Tool Mark Comparisons Obtained Using a Quantitative, Comparative, Statistical Algorithm

A statistical analysis and computational algorithm for comparing pairs of tool marks via profilometry data is described. Empirical validation of the method is established through experiments based on tool marks made at selected fixed angles from 50 sequentially manufactured screwdriver tips. Results obtained from three different comparison scenarios are presented and are in agreement with experiential knowledge possessed by practicing examiners. Further comparisons between scores produced by the algorithm and visual assessments of the same tool mark pairs by professional tool mark examiners in a blind study in general show good agreement between the algorithm and human experts. In specific instances where the algorithm had difficulty in assessing a particular comparison pair, results obtained during the collaborative study with professional examiners suggest ways in which algorithm performance may be improved. It is concluded that the addition of contextual information when inputting data into the algorithm should result in better performance

Population Genetic Structure and Phylogeography of \u3ci\u3eMesokalliapseudes macsweenyi\u3c/i\u3e (Crustacea: Tanaidacea) in the Northwestern Atlantic and Gulf of Mexico

Various studies of Gulf of Mexico/Atlantic populations have detected a phylogeographic break created by the Florida peninsula despite the fact that many of these species possess planktonic larvae and/or highly vagile adults. In light of these results, one would predict that the genetic structure in a species with limited dispersal ability would be heavily influenced by the geologic history of this region. Mesokalliapseudes macsweenyi is a direct developing benthic crustacean that occurs in coastal regions of the southeastern United States, ranging from South Carolina to Mississippi. Mitochondrial cytochrome oxidase subunit I (COI) sequences were obtained from 159 specimens representing eight collection sites from across a large portion of its known range to assess the population genetic and phylogeographic structure. Significant genetic structure existed among populations and between the Atlantic/Gulf of Mexico regions, consistent with expectations based on its life history of direct larval development and a sedentary adult stage. Demographic analyses inferred a population expansion in the Gulf of Mexico, which might reflect a Pleistocene post-glacial range expansion. The significant population structure exhibited by the northern Gulf of Mexico populations is likely the product of isolation among populations post expansion, but the diversity of haplotypes might also reflect under-sampled variation or the persistence of individuals in northern refugia during the Pleistocene. Crown Copyright (c) 2011 Published by Elsevier B.V. All rights reserved

Ecological and Genetic Assessment of Spatial Structure among Replicate Contact Zones between Two Topminnow Species

The spatial structure of contact zones is often described as disjunct, diffuse or mosaic and presumed to be related to underlying ecological gradients. However, the ecology of contact zones, how they are structured, and if that structure is predictable based on the strength and nature of ecological gradients is unknown. Large spatial scales and the unreplicated nature of many of the best studied contact zones has made it difficult to codify broader ecological patterns. Freshwater stream fish contact zones have the advantage of being potentially replicated with well defined boundaries and predictable linear gradients (river continuum concept). We sampled four replicate topminnow (Fundulus olivaceus and F. notatus) contact zones in Gulf of Mexico drainages. In each, we quantified contact zone spatial structure and the strength of ecological gradients (habitat, physicochemical variables and fish community functional traits). All three types of contact zone structure were represented. Systems with weaker gradients had diffuse contact zones, low species richness and were numerically dominated by generalist species. Rates of hybridization were also variable among systems. There was no hybridization detected in the mosaic zone while hybrids were found at most of the co-occurrence sites in the diffuse and disjunct zones. Overall, local ecology clearly influences contact zone structure and the two species interact in fundamentally different ways in these four systems

Shape Variability in Topminnows (Fundulus Notatus Species Complex) Along the River Continuum

We examined intra- and interspecific variability in shape of three topminnow species (Funduluidae: Fundulus notatus, F. olivaceus, and F. euryzonus) across ten drainages. Within each drainage, five or more adult male topminnows were digitized at multiple sites (83 total sites) along the river continuum representing a range of stream sizes (cumulative drainage area) and hydrological conditions. Nine of the ten drainages contained two Fundulus species that were longitudinally separated along the river continuum with narrow areas of coexistence. Upstream-downstream distribution patterns were variable by drainage, allowing us to examine patterns repeated across ecologically similar species. More variability in shape was explained by drainage (19.7%) than by species (7.4%) differences. Populations of F. notatus from headwaters (three drainages) converged on a deep-bodied form similar to F. olivaceus which was typically sampled in headwaters. Fundulus notatus shape was more closely related to stream size than in the other two species. Headwater populations of F. notatus and F. olivaceus had fineness ratios near the hydrodynamic optima of 4.5 whereas downstream populations of F. notatus had shallower bodies

Ecological and Genetic Assessment of Spatial Structure Among Replicate Contact Zones Between Two Topminnow Species

The spatial structure of contact zones is often described as disjunct, diffuse or mosaic and presumed to be related to underlying ecological gradients. However, the ecology of contact zones, how they are structured, and if that structure is predictable based on the strength and nature of ecological gradients is unknown. Large spatial scales and the unreplicated nature of many of the best studied contact zones has made it difficult to codify broader ecological patterns. Freshwater stream fish contact zones have the advantage of being potentially replicated with well defined boundaries and predictable linear gradients (river continuum concept). We sampled four replicate topminnow (Fundulus olivaceus and F. notatus) contact zones in Gulf of Mexico drainages. In each, we quantified contact zone spatial structure and the strength of ecological gradients (habitat, physicochemical variables and fish community functional traits). All three types of contact zone structure were represented. Systems with weaker gradients had diffuse contact zones, low species richness and were numerically dominated by generalist species. Rates of hybridization were also variable among systems. There was no hybridization detected in the mosaic zone while hybrids were found at most of the co-occurrence sites in the diffuse and disjunct zones. Overall, local ecology clearly influences contact zone structure and the two species interact in fundamentally different ways in these four systems