Rangia as Potential Indicators of Bay Health

Galveston Bay is an economically and ecologically important estuarine system on the Texas Coast sourced by freshwater inflows from an increasingly urbanized watershed. To regulate these flows, a baseline of ecological demands is established by monitoring biological response of estuarine organisms to changes in flows. Rangia clams have been identified as potential bioindicators for bay health. Historic rangia abundance and distribution data collected by TPWD and TCEQ showed that rangia were found in the greatest numbers in Trinity Bay and a decline in the overall population of Galveston Bay rangia throughout the past three decades. Though t-tests conducted on historical data showed that gear-related size exclusion significantly biased rangia CPUE and shell length data, smaller CPUE numbers in recent years compared to the rest of the historical record were supportive a genuine decline in rangia. After three years of present-day study (2012-2014), there was an observed increase in mean rangia shell length and decreases in mean meat index and areal density with a mean clam density of 25.3 (± 16.1) m^-2 in the Trinity River Delta and 22.5 (± 16.8) m^-2 in the Bay. Low mean monthly river discharges from the Trinity River during the study period complicated by drought and land use changes likely altered conditions which rangia require to for the survival of larvae and the initiation of spawning. These results also support the hypothesis that the low rangia densities found during the present-day study in Galveston Bay may be tied to the effects of drought conditions. PERMANOVA Main tests validated the comparability of the small-scale experimental design to long-term monitoring of bay wide sites by identifying significant variation in rangia abundance and health at different spatiotemporal levels. Multivariate analyses of clam health metrics and environmental parameters support a link between rangia health and variables influenced by freshwater inflow (salinity, DO, river discharge, dissolved nutrients) and explained one third of the variance in clam health metrics. Variables independent of FWI influence (temperature, water depth) were also related to clam health which further suggests that stressors unrelated to flows are compounding the effects of limited FWI on rangia

Subsistence, Butchery, and Commercialization in Knox County, Tennessee

A multifaceted approach to zooarchaeology is used to attain a broader diachronic view of Upland South subsistence and market activities as commercialization increased nationwide. Greater beef consumption is evidenced through faunal remains as availability and affordability increase with technological advancements. Paralleling this trend is an increased acceptance and purchase of Georgian cuts (individual hams and beef steaks) gaining popularity over time. In order to investigate this pattern, a sample of six historic archaeological sites in Knox County, Tennessee, differing in proximity to urban markets, socioeconomic status, ethnicity, and temporal context was chosen. General time ranges from the late eighteenth through the mid-twentieth century are used for descriptive purposes, and incorporate relevant historical, subsistence, and butchery data to demonstrate archaeological trends of a developing meat market. Additionally, the author proposes the identification of butchery saw and cut width measurements in historic zooarchaeology to glean greater information on individual site activities and market involvement

Rangia as Potential Indicators of Bay Health

Galveston Bay is an economically and ecologically important estuarine system on the Texas Coast sourced by freshwater inflows from an increasingly urbanized watershed. To regulate these flows, a baseline of ecological demands is established by monitoring biological response of estuarine organisms to changes in flows. Rangia clams have been identified as potential bioindicators for bay health. Historic rangia abundance and distribution data collected by TPWD and TCEQ showed that rangia were found in the greatest numbers in Trinity Bay and a decline in the overall population of Galveston Bay rangia throughout the past three decades. Though t-tests conducted on historical data showed that gear-related size exclusion significantly biased rangia CPUE and shell length data, smaller CPUE numbers in recent years compared to the rest of the historical record were supportive a genuine decline in rangia. After three years of present-day study (2012-2014), there was an observed increase in mean rangia shell length and decreases in mean meat index and areal density with a mean clam density of 25.3 (± 16.1) m^-2 in the Trinity River Delta and 22.5 (± 16.8) m^-2 in the Bay. Low mean monthly river discharges from the Trinity River during the study period complicated by drought and land use changes likely altered conditions which rangia require to for the survival of larvae and the initiation of spawning. These results also support the hypothesis that the low rangia densities found during the present-day study in Galveston Bay may be tied to the effects of drought conditions. PERMANOVA Main tests validated the comparability of the small-scale experimental design to long-term monitoring of bay wide sites by identifying significant variation in rangia abundance and health at different spatiotemporal levels. Multivariate analyses of clam health metrics and environmental parameters support a link between rangia health and variables influenced by freshwater inflow (salinity, DO, river discharge, dissolved nutrients) and explained one third of the variance in clam health metrics. Variables independent of FWI influence (temperature, water depth) were also related to clam health which further suggests that stressors unrelated to flows are compounding the effects of limited FWI on rangia

Towards an Understanding of the Interactions between Freshwater Inflows and Phytoplankton Communities in a Subtropical Estuary in the Gulf of Mexico

Subtropical estuaries worldwide face increased pressure on their ecosystem health and services due to increasing human population growth and associated land use/land cover changes, expansion of ports, and climate change. We investigated freshwater inflows (river discharge) and the physico-chemical characteristics of Galveston Bay (Texas, USA) as mechanisms driving variability in phytoplankton biomass and community composition between February 2008 and December 2009. Results of multivariate analyses (hierarchical cluster analysis, PERMANOVA, Mantel test, and nMDS ordination coupled to environmental vector fitting) revealed that temporal and spatial differences in phytoplankton community structure correlate to differences in hydrographic and water quality parameters. Spatially, phytoplankton biomass and community composition responded to nutrient loading from the San Jacinto River in the northwest region of the bay (consistent with nutrient limitation) while hydraulic displacement (and perhaps other processes) resulted in overall lower biomass in the Trinity River delta (northeast region). The influence of inflows on phytoplankton diminished along a north to south gradient in the bay. Temporally, temperature and variables associated with freshwater inflow (discharge volume, salinity, inorganic nitrogen and phosphorus concentrations) were major influences on phytoplankton dynamics. Dissolved inorganic nitrogen: phosphorus (DIN:DIP) ratios suggest that phytoplankton communities will be predominately nitrogen limited. Diatoms dominated during periods of moderate to high freshwater inflows in winter/spring and were more abundant in the upper bay while cyanobacteria dominated during summer/fall when inflow was low. Given the differential influences of freshwater inflow on the phytoplankton communities of Galveston Bay, alterations upstream (magnitude, timing, frequency) will likely have a profound effect on downstream ecological processes and corresponding ecosystem services

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

Novel genetic loci underlying human intracranial volume identified through genome-wide association

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth

Assessing Prevention Measures and Sin Nombre Hantavirus Seroprevalence Among Workers at Yosemite National Park

Background During 2012, a total of 10 overnight visitors to Yosemite National Park (Yosemite) became infected with a hantavirus (Sin Nombre virus [SNV]); three died. SNV infections have been identified among persons with occupational exposure to deer mice (Peromyscus maniculatus). Methods We assessed SNV infection prevalence, work and living environments, mice exposures, and SNV prevention training, knowledge, and practices among workers of two major employers at Yosemite during September–October, 2012 by voluntary blood testing and a questionnaire. Results One of 526 participants had evidence of previous SNV infection. Participants reported frequently observing rodent infestations at work and home and not always following prescribed safety practices for tasks, including infestation cleanup. Conclusion Although participants had multiple exposures to deer mice, we did not find evidence of widespread SNV infections. Nevertheless, employees working around deer mice should receive appropriate training and consistently follow prevention policies for high-risk activities

Differentially co‐expressed myofibre transcripts associated with abnormal myofibre proportion in chronic obstructive pulmonary disease

BackgroundSkeletal muscle dysfunction is a common extrapulmonary manifestation of chronic obstructive pulmonary disease (COPD). Alterations in skeletal muscle myosin heavy chain expression, with reduced type I and increased type II myosin heavy chain expression, are associated with COPD severity when studied in largely male cohorts. The objectives of this study were (1) to define an abnormal myofibre proportion phenotype in both males and females with COPD and (2) to identify transcripts and transcriptional networks associated with abnormal myofibre proportion in COPD.MethodsForty-six participants with COPD were assessed for body composition, strength, endurance and pulmonary function. Skeletal muscle biopsies from the vastus lateralis were assayed for fibre-type distribution and cross-sectional area via immunofluorescence microscopy and RNA-sequenced to generate transcriptome-wide gene expression data. Sex-stratified k-means clustering of type I and IIx/IIax fibre proportions was used to define abnormal myofibre proportion in participants with COPD and contrasted with previously defined criteria. Single transcripts and weighted co-expression network analysis modules were tested for correlation with the abnormal myofibre proportion phenotype.ResultsAbnormal myofibre proportion was defined in males with COPD (n = 29) as <18% type I and/or >22% type IIx/IIax fibres and in females with COPD (n = 17) as <36% type I and/or >12% type IIx/IIax fibres. Half of the participants with COPD were classified as having an abnormal myofibre proportion. Participants with COPD and an abnormal myofibre proportion had lower median handgrip strength (26.1 vs. 34.0 kg, P = 0.022), 6-min walk distance (300 vs. 353 m, P = 0.039) and forced expiratory volume in 1 s-to-forced vital capacity ratio (0.42 vs. 0.48, P = 0.041) compared with participants with COPD and normal myofibre proportions. Twenty-nine transcripts were associated with abnormal myofibre proportions in participants with COPD, with the upregulated NEB, TPM1 and TPM2 genes having the largest fold differences. Co-expression network analysis revealed that two transcript modules were significantly positively associated with the presence of abnormal myofibre proportions. One of these co-expression modules contained genes classically associated with muscle atrophy, as well as transcripts associated with both type I and type II myofibres, and was enriched for genetic loci associated with bone mineral density.ConclusionsOur findings indicate that there are significant transcriptional alterations associated with abnormal myofibre proportions in participants with COPD. Transcripts canonically associated with both type I and type IIa fibres were enriched in a co-expression network associated with abnormal myofibre proportion, suggesting altered transcriptional regulation across multiple fibre types