79717 research outputs found
Sort by
FieldJenniferEnvironMoleToxAerobicBiotransformationFluorotelomer .pdf
No full textThe aerobic biotransformation pathways of 4:2, 6:2, and 8:2 fluorotelomer thioether amido sulfonate (FtTAoS) were characterized by determining the fate of the compounds in soil and medium microcosms amended with an aqueous film-forming foam (AFFF) solution. The biotransformation of FtTAoS occurred in live microcosms over approximately 40 days and produced 4:2, 6:2, and 8:2 fluorotelomer sulfonate (FtS), 6:2 fluorotelomer unsaturated carboxylic acid (FtUCA), 5:3 fluorotelomer carboxylic acid (FtCA), and C₄ to C₈ perfluorinated carboxylic acids (PFCAs). Two biotransformation products corresponding to singly and doubly oxygenated forms of 6:2 FtTAoS were also identified through high resolution mass spectrometry (MS) analysis and liquid chromatography tandem-MS. An oxidative assay was used to indirectly quantify the total concentration of polyfluorinated compounds and check the mass balance. The assay produced near complete mass recovery of FtTAoS after biotransformation, with 10% (mol/mol) of the amended FtTAoS accounted for in FtS, FtCA, and PFCA products. The transformation rates of identified products appear to be slow relative to FtTAoS, indicating that some intermediates may persist in the environment. This study confirms some of the sources of FtS and PFCAs in groundwater and soil at AFFF-impacted sites and suggests that fluorinated intermediates that are not routinely measured during the biotransformation of PFASs may accumulate
Core Principles of the California Current Acidification Network: Linking Chemistry, Physics, and Ecological Effects
Get PDFNumerous monitoring efforts are underway to improve understanding of ocean acidification and its impacts on coastal environments, but there is a need to develop a coordinated approach that facilitates spatial and temporal comparisons of drivers and responses on a regional scale. Toward that goal, the California Current Acidification Network (C-CAN) held a series of workshops to develop a set of core principles for facilitating integration of ocean acidification monitoring efforts on the US West Coast. The recommended core principles include: (1) monitoring measurements should facilitate determination of aragonite saturation state (Ω[subscript]arag) as the common currency of comparison, allowing a complete description of the inorganic carbon system; (2) maximum uncertainty of ±0.2 in the calculation of Ω[subscript]arag is required to adequately link changes in ocean chemistry to changes in ecosystem function; (3) inclusion of a variety of monitoring platforms and levels of effort in the network will insure collection of high-frequency temporal data at fixed locations as well as spatial mapping across locations; (4) physical and chemical oceanographic monitoring should be linked with biological monitoring; and (5) the monitoring network should share data and make it accessible to a broad audience
Patterns and Variation in Benthic Biodiversity in a Large Marine Ecosystem
Get PDFWhile there is a persistent inverse relationship between latitude and species diversity across many taxa and ecosystems, deviations from this norm offer an opportunity to understand the conditions that contribute to large-scale diversity patterns. Marine systems, in particular, provide such an opportunity, as marine diversity does not always follow a strict latitudinal gradient, perhaps because several hypothesized drivers of the latitudinal diversity gradient are uncorrelated in marine systems. We used a large scale public monitoring dataset collected over an eight year period to examine benthic marine faunal biodiversity patterns for the continental shelf (55–183 m depth) and slope habitats (184–1280 m depth) off the US West Coast (47°20′N—32°40′N). We specifically asked whether marine biodiversity followed a strict latitudinal gradient, and if these latitudinal patterns varied across depth, in different benthic substrates, and over ecological time scales. Further, we subdivided our study area into three smaller regions to test whether coast-wide patterns of biodiversity held at regional scales, where local oceanographic processes tend to influence community structure and function. Overall, we found complex patterns of biodiversity on both the coast-wide and regional scales that differed by taxonomic group. Importantly, marine biodiversity was not always highest at low latitudes. We found that latitude, depth, substrate, and year were all important descriptors of fish and invertebrate diversity. Invertebrate richness and taxonomic diversity were highest at high latitudes and in deeper waters. Fish richness also increased with latitude, but exhibited a hump-shaped relationship with depth, increasing with depth up to the continental shelf break, ~200 m depth, and then decreasing in deeper waters. We found relationships between fish taxonomic and functional diversity and latitude, depth, substrate, and time at the regional scale, but not at the coast-wide scale, suggesting that coast-wide patterns can obscure important correlates at smaller scales. Our study provides insight into complex diversity patterns of the deep water soft substrate benthic ecosystems off the US West Coast
Effects of demineralization on the stable isotope analysis of bone samples
Get PDFRationale:
The sampling of sequential, annually formed bone growth layers for stable carbon (δ¹³C values) and nitrogen (δ¹⁵N values) isotope analysis (SIA) can provide a time series of foraging ecology data. To date, no standard protocol exists for the pre-SIA treatment of cortical samples taken from fresh, modern, bones.
Methods:
Based on the SIA of historical bone, it is assumed that fresh bone samples must be pre-treated with acid prior to SIA. Using an elemental analyzer coupled to an isotope ratio mass spectrometer to measure stable carbon and nitrogen ratios, we tested the need to acidify cortical bone powder with 0.25 M HCl prior to SIA to isolate bone collagen for the determination of δ¹³C and δ¹⁵ values. We also examined the need for lipid extraction to remove potential biases related to δ¹³C analysis, based on a C:N ratio threshold of 3.5.
Results:
It was found that acidification of micromilled cortical bone samples from marine turtles does not affect their δ¹⁵N values, and the small effect acidification has on δ¹³C values can be mathematically corrected for, thus eliminating the need for pre-SIA acidification of cortical bone. The lipid content of the cortical bone samples was low, as measured by their C:N ratios, indicating that lipid extracting cortical bone samples from modern marine turtles is unnecessary.
Conclusions:
We present a standard protocol for testing fresh, modern cortical bone samples prior to SIA, facilitating direct comparison of future studies. Based on the results obtained from marine turtle bones, pre-acidification and lipid removal of cortical bone are not recommended. This is especially useful as there is frequently not enough bone material removed via micromilling of sequential growth layers to accommodate both acid treatment and SIA
Closely-related taxa influence woody species discrimination via DNA barcoding: evidence from global forest dynamics plots
Get PDFTo determine how well DNA barcodes from the chloroplast region perform in forest dynamics plots (FDPs) from global CTFS-ForestGEO network, we analyzed DNA barcoding sequences of 1277 plant species from a wide phylogenetic range (3 FDPs in tropics, 5 in subtropics and 5 in temperate zone) and compared the rates of species discrimination (RSD). We quantified RSD by two DNA barcode combinations (rbcL + matK and rbcL + matK + trnH-psbA) using a monophyly-based method (GARLI). We defined two indexes of closely-related taxa (G[subscript]m/G[subscript]t and S/G ratios) and correlated these ratios with RSD. The combination of rbcL + matK averagely discriminated 88.65%, 83.84% and 72.51% at the local, regional and global scales, respectively. An additional locus trnH-psbA increased RSD by 2.87%, 1.49% and 3.58% correspondingly. RSD varied along a latitudinal gradient and were negatively correlated with ratios of closely-related taxa. Successes of species discrimination generally depend on scales in global FDPs. We suggested that the combination of rbcL + matK + trnH-psbA is currently applicable for DNA barcoding-based phylogenetic studies on forest communities.Supplementary information accompanies this paper at http://www.nature.com/srep. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Nature Publishing Group. The published article can be found at: http://www.nature.com/articles/srep1512
Archives and the Arts: Showcasing the Histories of Communities of Color
Get PDFArts organizations can beautifully express a community's identity through music, dance, and theatre. Through their performances and outreach activities, performing arts organizations can engage audiences in transformative experiences. However, an arts organization is more than just "the performance." The behind-the-scenes of an arts organization provides its own unique narrative documenting a company's rich history that can be made available to the public through archival collections, which can include materials such as administrative records, grants, financial documents, community outreach activities, in addition to audio and video recordings. Similarly, an archive can be more than just a physical repository of those collections. It can showcase a performing arts organization's records through a number of outreach efforts for the benefit of both the performing arts group and the archival repository that collaborates with it and stewards the collection. The Oregon Multicultural Archives (OMA) exemplifies this type of collaboration with two of Oregon's leading performing arts groups, the Obo Addy Legacy Project and the Milagro theatre company.This is the publisher’s final pdf. The published article is copyrighted by the Theatre Library Association and can be found at: http://www.tla-online.org/resources/publications/performing-arts-resources/
"You're Really Gonna Kick Us All Out?" Sustaining Safe Spaces for Community-Based HIV Prevention and Control among Black Men Who Have Sex with Men
Get PDFBlack men who have sex with men (BMSM) experience among the highest rates of HIV infection in the United States. We conducted a community-based ethnography in New York City to identify the structural and environmental factors that influence BMSMs vulnerability to HIV and their engagement with HIV prevention services. Methods included participant observation at community-based organizations (CBOs) in New York City, in-depth interviews with 31 BMSM, and 17 key informant interviews. Our conceptual framework shows how creating and sustaining safe spaces could be a critical environmental approach to reduce vulnerability to HIV among BMSM. Participant observation, in-depth and key informant interviews revealed that fear and mistrust characterized men’s relation to social and public institutions, such as churches, schools, and the police. This fear and mistrust created HIV vulnerability among the BMSM in our sample by challenging engagement with services. Our findings suggest that to be successful, HIV prevention efforts must address these structural and environmental vulnerabilities. Among the CBOs that we studied, “safe spaces” emerged as an important tool for addressing these environmental vulnerabilities. CBOs used safe spaces to provide social support, to address stigma, to prepare men for the workforce, and to foster a sense of community among BMSM. In addition, safe spaces were used for HIV and STI testing and treatment campaigns. Our ethnographic findings suggest that safe spaces represent a promising but so far under-utilized part of HIV prevention infrastructure. Safe spaces seem integral to high impact comprehensive HIV prevention efforts, and may be considered more appropriately as part of HIV capacity-building rather than being nested within program-specific funding structures
RosalesStephanieMicrobiologyBrainMetaTranscriptomics(Correction).pdf
No full textMarine diseases are becoming more frequent, and tools for identifying pathogens and disease
reservoirs are needed to help prevent and mitigate epizootics. Meta-transcriptomics
provides insights into disease etiology by cataloguing and comparing sequences from suspected
pathogens. This method is a powerful approach to simultaneously evaluate both the
viral and bacterial communities, but few studies have applied this technique in marine systems.
In 2009 seven harbor seals, Phoca vitulina, stranded along the California coast from a
similar brain disease of unknown cause of death (UCD). We evaluated the differences
between the virome and microbiome of UCDs and harbor seals with known causes of
death. Here we determined that UCD stranded animals had no viruses in their brain tissue.
However, in the bacterial community, we identified Burkholderia and Coxiella burnetii as
important pathogens associated with this stranding event. Burkholderia were 100% prevalent
and ~2.8 log2 fold more abundant in the UCD animals. Further, while C. burnetii was
found in only 35.7% of all samples, it was highly abundant (~94% of the total microbial community)
in a single individual. In this harbor seal, C. burnetii showed high transcription rates
of invading and translation genes, implicating it in the pathogenesis of this animal. Based on
these data we propose that Burkholderia taxa and C. burnetii are potentially important
opportunistic neurotropic pathogens in UCD stranded harbor seals
A Synthesis of Year-Round Interdisciplinary Mooring Measurements in the Bering Strait (1990-2014) and the RUSALCA Years (2004-2011)
Get PDFThe flow through the Bering Strait, the only Pacific-Arctic oceanic gateway, has dramatic local, regional, and global impacts. Advanced year-round moored technology quantifies challengingly large temporal (subdaily, seasonal, and interannual) and spatial variability in the ~85 km wide, two-channel strait. The typically northward flow, intensified seasonally in the ~10–20 km wide, warm, fresh, nutrient-poor Alaskan Coastal Current (ACC) in the east, is otherwise generally homogeneous in velocity throughout the strait, although with higher salinities and nutrients and lower temperatures in the west. Velocity and water properties respond rapidly (including flow reversals) to local wind, likely causing most of the strait’s approximately two-layer summer structure (by “spilling” the ACC) and winter water-column homogenization. We identify island-trapped eddy zones in the central strait; changes in sea-ice properties (season mean thicknesses from 2 m); and increases in annual mean volume, heat, and freshwater fluxes from 2001 to present (2013). Tantalizing first results from year-round bio-optics, nitrate, and ocean acidification sensors indicate significant seasonal and spatial change, possibly driven by the spring bloom. Moored acoustic recorders show large interannual variability in sub-Arctic whale occurrence, related perhaps to water property changes. Substantial daily variability demonstrates the dangers of interpreting section data and the necessity for year-round interdisciplinary time-series measurements.This is the publisher’s final pdf. The published article is copyrighted by the Oceanography Society and can be found at: http://tos.org/oceanography/article/a-synthesis-of-year-round-interdisciplinary-mooring-measurements-in-the-ber Bering Strait physical oceanographic data are available via http://psc.apl.washington.edu/BeringStrait.html and the National Oceanographic Data Center (https://www.nodc.noaa.gov); ocean acidification data, via http://aoncadis.org; and marine mammal acoustic data, via http://aoncadis.org and http://AOOS.org
SathuvalliVidyasagarCropSoilSciAcrylamideFormingPotential(FiguresS1-S2).pdf
No full textProcessed potato (Solanum tuberosum L.) products, such as chips and French fries, contribute to the dietary intake of acrylamide, a suspected human carcinogen. One of the most promising approaches for reducing its consumption is to develop and commercialize new potato varieties with low acrylamide-forming potential. To facilitate this effort, a National Fry Processing Trial (NFPT) was conducted from 2011 to 2013 in five states. More than 140 advanced breeding lines were evaluated for tuber agronomic traits and biochemical properties from harvest through 8 mo of storage. Thirty-eight and 29 entries had significantly less acrylamide in French fries than standard varieties Russet Burbank and Ranger Russet, with reductions in excess of 50%, after one and 8 mo of storage, respectively. As in previous studies, the glucose content of raw tubers was predictive of acrylamide in finished French fries (R² = 0.64–0.77). Despite its role in acrylamide formation, tuber free asparagine was not significant, potentially because it showed relatively little variation in the NFPT population. Even when glucose was included in the model as a covariate, genotype was highly significant (p = 0.001) for predicting acrylamide, indicating there may be yet-unidentified genetic loci to target in breeding. The NFPT has demonstrated that there exist many elite US breeding lines with low acrylamide-forming potential. Our ongoing challenge is to combine this trait with complex quality attributes required by the fry processing industry