251 research outputs found
The Role of Benthic Fluxes of Dissolved Organic Carbon in Oceanic and Sedimentary Carbon Cycling
Benthic fluxes (sediment-water exchange) of dissolved organic carbon (DOC) represent a poorly quantified component of sedimentary and oceanic carbon cycling. In this paper we use pore water DOC data and direct DOC benthic flux measurements to begin to quantitatively examine this problem. These results suggest that marine sediments represent a significant source of DOC to the oceans, as a lower limit of the globally-integrated benthic DOC flux is comparable in magnitude to riverine inputs of organic carbon to the oceans. Benthic fluxes of DOC also appear to be similar in magnitude to other sedimentary processes such as organic carbon oxidation (remineralization) in surface sediments and organic carbon burial with depth
Chemistry of aerosols, cloud droplets, and rain in the Puerto Rican marine atmosphere
The chemical changes occurring during the transformation of aerosols to cloud droplets and rain were observed in orographic clouds on the eastern end of the island of Puerto Rico. Comparisons of elemental ratios in particles and rain and of elemental particle size distributions in and out of the clouds demonstrated scavenging efficiencies of >100% for the elements I, Br, and Cl relative to Na and of <25% for the elements Al, Mn, and V relative to Na. These different scavenging efficiencies are consistent with predictions based on existing cloud physics theory and are a reflection of the geochemical properties of the aerosol consisting partly of a hygroscopic sea salt component containing I, Br, Cl, and Na and partly of a soil dust component containing Al, Mn, and possibly V
BORON IN COASTAL NORTH FLORIDA RAINFALL.
Dissolved boron and sodium concentrations were determined in rainfall collected on the Gulf Coast of northern Florida in order to investigate chemical and physical processes influencing natural concentration levels in the coastal marine atmosphere. Rainfall samples were collected during summer showers, during drizzle and heavy downpours associated with winter frontal activities, and sequentially during tropical storm Becky. Mean calculated B enrichments E//N//a(B) for summer and winter sample sets were 32 and 11, respectively. A surprisingly constant concentration of 'excess' B above that expected from direct seawater injection of approximately 6 mu g 1** minus **1 was observed in the sequential Becky samples. The lower winter B/Na ratios, and thus the calculated E//N//a(B) values, appear related to higher Na concentrations; however, several alternative hypotheses can be advanced to explain the results, including greater particulate sea-salt injection during winter months, incorporation of soil materials with a B/Na ratio above the seawater value, and possible influences of temperature variation on gaseous B incorporation in rain and evaporation from the sea surface
OTULIN protects the intestinal epithelium from apoptosis during inflammation and infection
The intestinal epithelium is a single cell layer that is constantly renewed and acts as a physical barrier that separates intestinal microbiota from underlying tissues. In inflammatory bowel disease (IBD) in humans, as well as in experimental mouse models of IBD, this barrier is impaired, causing microbial infiltration and inflammation. Deficiency in OTU deubiquitinase with linear linkage specificity (OTULIN) causes OTULIN-related autoinflammatory syndrome (ORAS), a severe inflammatory pathology affecting multiple organs including the intestine. We show that mice with intestinal epithelial cell (IEC)-specific OTULIN deficiency exhibit increased susceptibility to experimental colitis and are highly sensitive to TNF toxicity, due to excessive apoptosis of OTULIN deficient IECs. OTULIN deficiency also increases intestinal pathology in mice genetically engineered to secrete excess TNF, confirming that chronic exposure to TNF promotes epithelial cell death and inflammation in OTULIN deficient mice. Mechanistically we demonstrate that upon TNF stimulation, OTULIN deficiency impairs TNF receptor complex I formation and LUBAC recruitment, and promotes the formation of the cytosolic complex II inducing epithelial cell death. Finally, we show that OTULIN deficiency in IECs increases susceptibility to Salmonella infection, further confirming the importance of OTULIN for intestinal barrier integrity. Together, these results identify OTULIN as a major anti-apoptotic protein in the intestinal epithelium and provide mechanistic insights into how OTULIN deficiency drives gastrointestinal inflammation in ORAS patients.</p
Allogeneic Hematopoietic Cell Transplantation Improves Outcome in Myelodysplastic Syndrome Across High-Risk Genetic Subgroups:Genetic Analysis of the Blood and Marrow Transplant Clinical Trials Network 1102 Study
PURPOSE:Allogeneic hematopoietic cell transplantation (HCT) in patients with myelodysplastic syndrome (MDS) improves overall survival (OS). We evaluated the impact of MDS genetics on the benefit of HCT in a biological assignment (donor v no donor) study.METHODS:We performed targeted sequencing in 309 patients age 50-75 years with International Prognostic Scoring System (IPSS) intermediate-2 or high-risk MDS, enrolled in the Blood and Marrow Transplant Clinical Trials Network 1102 study and assessed the association of gene mutations with OS. Patients with TP53 mutations were classified as TP53multihit if two alleles were altered (via point mutation, deletion, or copy-neutral loss of heterozygosity).RESULTS:The distribution of gene mutations was similar in the donor and no donor arms, with TP53 (28% v 29%; P =.89), ASXL1 (23% v 29%; P =.37), and SRSF2 (16% v 16%; P =.99) being most common. OS in patients with a TP53 mutation was worse compared with patients without TP53 mutation (21% ± 5% [SE] v 52% ± 4% at 3 years; P <.001). Among those with a TP53 mutation, OS was similar between TP53single versus TP53multihit (22% ± 8% v 20% ± 6% at 3 years; P =.31). Considering HCT as a time-dependent covariate, patients with a TP53 mutation who underwent HCT had improved OS compared with non-HCT treatment (OS at 3 years: 23% ± 7% v 11% ± 7%; P =.04), associated with a hazard ratio of 3.89; 95% CI, 1.87 to 8.12; P <.001 after adjustment for covariates. OS among patients with molecular IPSS (IPSS-M) very high risk without a TP53 mutation was significantly improved if they had a donor (68% ± 10% v 0% ± 12% at 3 years; P =.001).CONCLUSION:HCT improved OS compared with non-HCT treatment in patients with TP53 mutations irrespective of TP53 allelic status. Patients with IPSS-M very high risk without a TP53 mutation had favorable outcomes when a donor was available.</p
Coastal Ocean Processes : a science prospectus
CoOP (Coastal Ocean Processes) is an organization meant to study major interdisciplinary scientific
problems in the coastal ocean. Its goal is "to obtain a new level of quantitative understanding of the processes
that dominate the transformations, transport and fates of biologically, chemically and geologically important matter on the continental margin". Central to obtaining this understanding will be advances in observing and
modeling the cross-shelf component of transport. More specific objectives are to understand 1) cross-margin
exchanges, 2) air sea exchanges, 3) benthic-pelagic exchanges, 4) terrestrial inputs and 5) biological and
chemical transformations within the water column. CoOP research will be carried out primarly through a
series of process-oriented field studies, each involving about two years of measurements. Each of these field
studies is to be initiated and defined through a community workshop. In addition to the process studies, CoOP
will also involve modeling, long time series, exploratory studies, remote sensing, technological innovation, data
archiving and communications. A CoOP pilot study has been approved for funding by the National Science
Foundation, and funding will begin in 1992. The CoOP science effort is thus already underway.Funding was provided by the National Science Foundation under
Grant No. OCE-9108993
Implementing health research through academic and clinical partnerships : a realistic evaluation of the Collaborations for Leadership in Applied Health Research and Care (CLAHRC)
Background: The English National Health Service has made a major investment in nine partnerships between
higher education institutions and local health services called Collaborations for Leadership in Applied Health
Research and Care (CLAHRC). They have been funded to increase capacity and capability to produce and
implement research through sustained interactions between academics and health services. CLAHRCs provide a
natural ‘test bed’ for exploring questions about research implementation within a partnership model of delivery.
This protocol describes an externally funded evaluation that focuses on implementation mechanisms and
processes within three CLAHRCs. It seeks to uncover what works, for whom, how, and in what circumstances.
Design and methods: This study is a longitudinal three-phase, multi-method realistic evaluation, which
deliberately aims to explore the boundaries around knowledge use in context. The evaluation funder wishes to see
it conducted for the process of learning, not for judging performance. The study is underpinned by a conceptual
framework that combines the Promoting Action on Research Implementation in Health Services and Knowledge to
Action frameworks to reflect the complexities of implementation. Three participating CLARHCS will provide indepth
comparative case studies of research implementation using multiple data collection methods including
interviews, observation, documents, and publicly available data to test and refine hypotheses over four rounds of
data collection. We will test the wider applicability of emerging findings with a wider community using an
interpretative forum.
Discussion: The idea that collaboration between academics and services might lead to more applicable health
research that is actually used in practice is theoretically and intuitively appealing; however the evidence for it is
limited. Our evaluation is designed to capture the processes and impacts of collaborative approaches for
implementing research, and therefore should contribute to the evidence base about an increasingly popular (e.g.,
Mode two, integrated knowledge transfer, interactive research), but poorly understood approach to knowledge
translation. Additionally we hope to develop approaches for evaluating implementation processes and impacts
particularly with respect to integrated stakeholder involvement
Considerations for best practices in studies of fiber or other dietary components and the intestinal microbiome
Considerations for best practices in studies of fiber or other dietary components and the intestinal microbiome. Am J Physiol Endocrinol Metab 315: E1087–E1097, 2018. First published August 21, 2018; doi:10.1152/ajpendo.00058.2018.—A 2-day workshop organized by the National Institutes of Health and U.S. Department of Agriculture included 16 presentations focused on the role of diet in alterations of the gastrointestinal microbiome, primarily that of the colon. Although thousands of research projects have been funded by U.S. federal agencies to study the intestinal microbiome of humans and a variety of animal models, only a minority addresses dietary effects, and a small subset is described in sufficient detail to allow reproduction of a study. Whereas there are standards being developed for many aspects of microbiome studies, such as sample collection, nucleic acid extraction, data handling, etc., none has been proposed for the dietary component; thus this workshop focused on the latter specific point. It is important to foster rigor in design and reproducibility of published studies to maintain high quality and enable designs that can be compared in systematic reviews. Speakers addressed the influence of the structure of the fermentable carbohydrate on the microbiota and the variables to consider in design of studies using animals, in vitro models, and human subjects. For all types of studies, strengths and weaknesses of various designs were highlighted, and for human studies, comparisons between controlled feeding and observational designs were discussed. Because of the lack of published, best-diet formulations for specific research questions, the main recommendation is to describe dietary ingredients and treatments in as much detail as possible to allow reproduction by other scientists
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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