3,818 research outputs found

    Mapping biodiversity value worldwide: combining higher-taxon richness from different groups

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    Maps of large-scale biodiversity are urgently needed to guide conservation, and yet complete enumeration of organisms is impractical at present. One indirect approach is to measure richness at higher taxonomic ranks, such as families. The difficulty is how to combine information from different groups on numbers of higher taxa, when these taxa may in effect have been defined in different ways, particularly for more distantly related major groups. In this paper, the regional family richness of terrestrial and freshwater seed plants, amphibians, reptiles and mammals is mapped worldwide by combining: (i) absolute family richness; (ii) proportional family richness; and (iii) proportional family richness weighted for the total species richness in each major group. The assumptions of the three methods and their effects on the results are discussed, although for these data the broad pattern is surprisingly robust with respect to the method of combination. Scores from each of the methods of combining families are used to rank the top five richness hotspots and complementary areas, and hotspots of endemism are mapped by unweighted combination of range-size rarity scores

    Development of Fluorescence Polarization Assays for the Molecular Chaperone Hsp70 Family Members: Hsp72 and DnaK

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    The heat shock protein 70 (Hsp70) family of chaperones play crucial roles in protein folding and have been linked to numerous diseases. We were interested in developing a generally applicable assay format for the Hsp70 family and have developed fluorescence polarization based assays for both the mammalian Hsp72 and its bacterial counterpart, DnaK. These assays are comparable in assay set-up, incubation conditions and buffer components. Both unfolded polypeptides and synthetic peptides can be utilized as tracers to detect binding although peptides meeting the minimum seven residue length for Hsp70 binders have weaken binding when modified with fluorescein presumably due to steric effects. Although we did not identify a suitable general substrate for all Hsp70 proteins, fluorescein tagged peptide substrates that gave high affinity binding were identified for both DnaK and hsp72. We would predict that these assays will be suitable for identifying both selective chemical probes of Hsp70 family members and “pan” Hsp70 inhibitors

    Unique Transcriptional Profile of Sustained Ligand-Activated Preconditioning in Pre- and Post-Ischemic Myocardium

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    BACKGROUND: Opioidergic SLP (sustained ligand-activated preconditioning) induced by 3–5 days of opioid receptor (OR) agonism induces persistent protection against ischemia-reperfusion (I-R) injury in young and aged hearts, and is mechanistically distinct from conventional preconditioning responses. We thus applied unbiased gene-array interrogation to identify molecular effects of SLP in pre- and post-ischemic myocardium. METHODOLOGY/PRINCIPAL FINDINGS: Male C57Bl/6 mice were implanted with 75 mg morphine or placebo pellets for 5 days. Resultant SLP did not modify cardiac function, and markedly reduced dysfunction and injury in perfused hearts subjected to 25 min ischemia/45 min reperfusion. Microarray analysis identified 14 up- and 86 down-regulated genes in normoxic hearts from SLP mice (≥1.3-fold change, FDR≤5%). Induced genes encoded sarcomeric/contractile proteins (Myh7, Mybpc3,Myom2,Des), natriuretic peptides (Nppa,Nppb) and stress-signaling elements (Csda,Ptgds). Highly repressed genes primarily encoded chemokines (Ccl2,Ccl4,Ccl7,Ccl9,Ccl13,Ccl3l3,Cxcl3), cytokines (Il1b,Il6,Tnf) and other proteins involved in inflammation/immunity (C3,Cd74,Cd83, Cd86,Hla-dbq1,Hla-drb1,Saa1,Selp,Serpina3), together with endoplasmic stress proteins (known: Dnajb1,Herpud1,Socs3; putative: Il6, Gadd45g,Rcan1) and transcriptional controllers (Egr2,Egr3, Fos,Hmox1,Nfkbid). Biological themes modified thus related to inflammation/immunity, together with cellular/cardiovascular movement and development. SLP also modified the transcriptional response to I-R (46 genes uniquely altered post-ischemia), which may influence later infarction/remodeling. This included up-regulated determinants of cellular resistance to oxidant (Mgst3,Gstm1,Gstm2) and other forms of stress (Xirp1,Ankrd1,Clu), and repression of stress-response genes (Hspa1a,Hspd1,Hsp90aa,Hsph1,Serpinh1) and Txnip. CONCLUSIONS: Protection via SLP is associated with transcriptional repression of inflammation/immunity, up-regulation of sarcomeric elements and natriuretic peptides, and modulation of cell stress, growth and development, while conventional protective molecules are unaltered

    CFD Code Validation of Wall Heat Fluxes for a G02/GH2 Single Element Combustor

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    This paper puts forth the case for the need for improved injector design tools to meet NASA s Vision for Space Exploration goals. Requirements for this improved tool are outlined and discussed. The potential for Computational Fluid Dynamics (CFD) to meet these requirements is noted along with its current shortcomings, especially relative to demonstrated solution accuracy. The concept of verification and validation is introduced as the primary process for building and quantifying the confidence necessary for CFD to be useful as an injector design tool. The verification and validation process is considered in the context of the Marshall Space Flight Center (MSFC) Combustion Devices CFD Simulation Capability Roadmap via the Simulation Readiness Level (SRL) concept. The portion of the validation process which demonstrates the ability of a CFD code to simulate heat fluxes to a rocket engine combustor wall is the focus of the current effort. The FDNS and Loci-CHEM codes are used to simulate a shear coaxial single element G02/GH2 injector experiment. The experiment was conducted a t a chamber pressure of 750 psia using hot propellants from preburners. A measured wall temperature profile is used as a boundary condition to facilitate the calculations. Converged solutions, obtained from both codes by using wall functions with the K-E turbulence model and integrating to the wall using Mentor s baseline turbulence model, are compared to the experimental data. The initial solutions from both codes revealed significant issues with the wall function implementation associated with the recirculation zone between the shear coaxial jet and the chamber wall. The FDNS solution with a corrected implementation shows marked improvement in overall character and level of comparison to the data. With the FDNS code, integrating to the wall with Mentor s baseline turbulence model actually produce a degraded solution when compared to the wall function solution with the K--E model. The Loci-CHEM solution, produced by integrating to the wall with Mentor s baseline turbulence model, matches both the heat flux rise rate in the near injector region and the peak heat flux level very well. However, it moderately over predicts the heat fluxes downstream of the reattachment point. The Loci-CHEM solution achieved by integrating to the wall with Mentor s baseline turbulence model was clearly superior to the other solutions produced in this effort

    ALMA Observations of Asymmetric Molecular Gas Emission from a Protoplanetary Disk in the Orion Nebula

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    We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of molecular line emission from d216-0939, one of the largest and most massive protoplanetary disks in the Orion Nebula Cluster (ONC). We model the spectrally resolved HCO+^+ (4--3), CO (3--2), and HCN (4--3) lines observed at 0\farcs5 resolution to fit the temperature and density structure of the disk. We also weakly detect and spectrally resolve the CS (7--6) line but do not model it. The abundances we derive for CO and HCO+^+ are generally consistent with expected values from chemical modeling of protoplanetary disks, while the HCN abundance is higher than expected. We dynamically measure the mass of the central star to be 2.17±0.07M2.17\pm0.07\,M_\odot which is inconsistent with the previously determined spectral type of K5. We also report the detection of a spatially unresolved high-velocity blue-shifted excess emission feature with a measurable positional offset from the central star, consistent with a Keplerian orbit at 60±20au60\pm20\,\mathrm{au}. Using the integrated flux of the feature in HCO+^+ (4--3), we estimate the total H2_2 gas mass of this feature to be at least 1.88MJupiter1.8-8\,M_\mathrm{Jupiter}, depending on the assumed temperature. The feature is due to a local temperature and/or density enhancement consistent with either a hydrodynamic vortex or the expected signature of the envelope of a forming protoplanet within the disk.Comment: 19 pages, 12 figures, accepted for publication in A

    Hypoxia Augments Outgrowth Endothelial Cell (OEC) Sprouting and Directed Migration in Response to Sphingosine-1-Phosphate (S1P)

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    Therapeutic angiogenesis provides a promising approach to treat ischemic cardiovascular diseases through the delivery of proangiogenic cells and/or molecules. Outgrowth endothelial cells (OECs) are vascular progenitor cells that are especially suited for therapeutic strategies given their ease of noninvasive isolation from umbilical cord or adult peripheral blood and their potent ability to enhance tissue neovascularization. These cells are recruited to sites of vascular injury or tissue ischemia and directly incorporate within native vascular endothelium to participate in neovessel formation. A better understanding of how OEC activity may be boosted under hypoxia with external stimulation by proangiogenic molecules remains a challenge to improving their therapeutic potential. While vascular endothelial growth factor (VEGF) is widely established as a critical factor for initiating angiogenesis, sphingosine-1-phosphate (S1P), a bioactive lysophospholipid, has recently gained great enthusiasm as a potential mediator in neovascularization strategies. This study tests the hypothesis that hypoxia and the presence of VEGF impact the angiogenic response of OECs to S1P stimulation in vitro. We found that hypoxia altered the dynamically regulated S1P receptor 1 (S1PR1) expression on OECs in the presence of S1P (1.0 mu M) and/or VEGF (1.3 nM). the combined stimuli of S1P and VEGF together promoted OEC angiogenic activity as assessed by proliferation, wound healing, 3D sprouting, and directed migration under both normoxia and hypoxia. Hypoxia substantially augmented the response to S1P alone, resulting in similar to 6.5-fold and similar to 25-fold increases in sprouting and directed migration, respectively. Overall, this report highlights the importance of establishing hypoxic conditions in vitro when studying ischemia-related angiogenic strategies employing vascular progenitor cells.University of California, DavisAmerican Heart Association (AHA)Univ Calif Davis, Dept Biomed Engn, Davis, CA 95616 USAUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilUniv Calif Davis, Dept Neurobiol Physiol & Behav, Davis, CA 95616 USAUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilAmerican Heart Association (AHA): 15PRE22930044Web of Scienc

    The need for increased protection of Antarctica's inland waters

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    Protection of Antarctica's biodiversity and ecosystem values is enshrined in the Protocol on Environmental Protection to the Antarctic Treaty, which provides for the designation of Antarctic Specially Protected Areas (ASPAs) to areas with outstanding values. Concern has been raised that existing ASPAs fail to prioritize areas to maximize the likelihood of ensuring the long-term conservation of Antarctic ecosystems and biodiversity. The absence of systematic and representative protection is particularly acute for inland aquatic ecosystems, which support a disproportionate amount of inland biodiversity. This paper promotes the case for overt inclusion of inland waters as a critical component of a representative protected area framework for Antarctica, thereby addressing their current underrepresentation. We set out a structured approach to enable the selection of representative freshwater systems for inclusion in the ASPA framework that, with modification, could also be applied across other Antarctic habitats. We acknowledge an overall lack of information on the biogeography of inland aquatic diversity and recommend increased use of remote data collection along with classification tools to mitigate this, as well as the need for the consideration of catchment-scale processes. Changes that accompany contemporary and anticipated climate change make the need for the conservation of representative biodiversity increasingly urgen
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