3,189 research outputs found

    Computational wing optimization and comparisons with experiment for a semi-span wing model

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    A computational wing optimization procedure was developed and verified by an experimental investigation of a semi-span variable camber wing model in the NASA Ames Research Center 14 foot transonic wind tunnel. The Bailey-Ballhaus transonic potential flow analysis and Woodward-Carmichael linear theory codes were linked to Vanderplaats constrained minimization routine to optimize model configurations at several subsonic and transonic design points. The 35 deg swept wing is characterized by multi-segmented leading and trailing edge flaps whose hinge lines are swept relative to the leading and trailing edges of the wing. By varying deflection angles of the flap segments, camber and twist distribution can be optimized for different design conditions. Results indicate that numerical optimization can be both an effective and efficient design tool. The optimized configurations had as good or better lift to drag ratios at the design points as the best designs previously tested during an extensive parametric study

    Autism, Social Comprehension, and Cognitive Impenetrability

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    Autism is a neurodevelopmental disorder featuring severe social and communicative deficits. Cognitive impenetrability is the inability of systems to be affected by an individual’s beliefs and desires. Individuals with autism have delayed performance on mindreading tasks. Mindreading is the interpretation of others which enables successful social interactions. This task performance is not correlated with everyday social function in autism. These deficits are in contrast with general intelligence and reasoning abilities within the normal range, resistant to cognitive behavioral training, and partially attributable to atypical social predispositions. This suggests individuals with autism perform social tasks differently than typicals. I argue that this mindreading deficit is cognitively impenetrable, then position this deficit within a theoretical framework, enactivism, emphasizing cognitive embodiment and inseparability of social comprehension and action. This framework helps explain the cognitive impenetrability of these social deficits by locating failure to penetrate in individuals\u27 failure to properly interact with the environment

    Investigation of stress corrosion cracking of titanium alloys Semiannual progress report, 1 Jun. - 30 Nov. 1966

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    Stress corrosion cracking mechanisms in titanium alloy foil

    Dramatic expansion of the black widow toxin arsenal uncovered by multi-tissue transcriptomics and venom proteomics.

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    BackgroundAnimal venoms attract enormous interest given their potential for pharmacological discovery and understanding the evolution of natural chemistries. Next-generation transcriptomics and proteomics provide unparalleled, but underexploited, capabilities for venom characterization. We combined multi-tissue RNA-Seq with mass spectrometry and bioinformatic analyses to determine venom gland specific transcripts and venom proteins from the Western black widow spider (Latrodectus hesperus) and investigated their evolution.ResultsWe estimated expression of 97,217 L. hesperus transcripts in venom glands relative to silk and cephalothorax tissues. We identified 695 venom gland specific transcripts (VSTs), many of which BLAST and GO term analyses indicate may function as toxins or their delivery agents. ~38% of VSTs had BLAST hits, including latrotoxins, inhibitor cystine knot toxins, CRISPs, hyaluronidases, chitinase, and proteases, and 59% of VSTs had predicted protein domains. Latrotoxins are venom toxins that cause massive neurotransmitter release from vertebrate or invertebrate neurons. We discovered ≥ 20 divergent latrotoxin paralogs expressed in L. hesperus venom glands, significantly increasing this biomedically important family. Mass spectrometry of L. hesperus venom identified 49 proteins from VSTs, 24 of which BLAST to toxins. Phylogenetic analyses showed venom gland specific gene family expansions and shifts in tissue expression.ConclusionsQuantitative expression analyses comparing multiple tissues are necessary to identify venom gland specific transcripts. We present a black widow venom specific exome that uncovers a trove of diverse toxins and associated proteins, suggesting a dynamic evolutionary history. This justifies a reevaluation of the functional activities of black widow venom in light of its emerging complexity

    The behaviour of tobacco varieties in Western Australia

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    With the advent of a number of new varieties into the district, several problems have arisen, and this article is being written in an endeavour to set down just what is known of the varieties being tested. In order to make definite recommendations regarding a certain variety of tobacco, it requires to be tested under a wide range of soil and climatic conditions. To cover as wide a range of weather conditions as possible, the variety needs to be grown for three years before any real recommendation is warranted. To cover a wide range of soil types, trials have been conducted in several areas over the past two years and results are being accumulated

    Safe From Subpoena? The Importance of Certificates of Confidentiality to the Viability and Ethics of Research

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    This Article addresses legal issues related to Certificates, recognizes that Certificates face an uncertain future if challenged in court—based on the statutory history and limited relevant case law—and proposes that changes should be made to ensure Certificates actually offer the protection they promise. Part II reviews the background of Certificates of Confidentiality. Part III explores how Certificates fulfill vital functions by encouraging research participation, satisfying ethical obligations of researchers to protect participant data, and promoting the accuracy of data provided by participants in research studies. Part IV observes that the case law relevant to Certificates of Confidentiality, though limited, presents cause for concern. Part V explores the potential threats to Certificates of Confidentiality. Part VI argues that, for legal and public policy reasons, courts and Congress should consider changes in the way they approach Certificates of Confidentiality in order to offer broad protection for participants involved in sensitive research studies. Additionally, this section provides recommendations for researchers to secure sensitive data

    Symmetrically H-Bridged Dimer of 2-Carboxylatobenzenediazonium. The 1:1 Complex between 2-Carboxybenzenediazonium Chloride and Benzenediazonium-2-carboxylate

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    The two zwitterions in the H-bridged dimer of 2-carboxylatobenzenediazonim (1) are linked by a crystallographically symmetric O⋯Hctdot;O hydrogen bond with an O⋯O distance of 2.436 (3) Ã…. Comparison of the (1) with the other benzenediazonium salts shows that the phenyl ring distortions in (1) are determined primarily by the diazonium substituent with only modest additional effects by the carboxylato group. Intramolecular neighboring goup interactions between the N2 group and the orthoCOO(H) group are indicated and are discussed. The terminal N atom of the diazonium group is bent away from the neighboring carboxylato group. The N2 and the carboxylato group are on the opposite sides of the best plane of the aromatic ring. Importantly, the carboxylato group is not fully conjugated with the aromatic ring but instead is rotated 6.5 (2)° around the C-CO2 axis in a fashion that suggest minimization of intramolecular repulsion between Nα and the proximate O atom and optimization of the inter-molecular hydrogen bonding

    Phylogenetic signals in detoxification pathways in Cyprinid and Centrarchid species in relation to sensitivity to environmental pollutants

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    Observations in a previous study on biomarker responses in fish collected from urban creeks in Greenville, SC, indicated that there might be considerable differences in the expression of biotransformation enzymes in chub and sunfish species. To further investigate these species differences a dosing experiment was performed in which bluehead and creek chub (Nocomis leptocephalus and Semotilus atromaculatus), and redbreast sunfish, pumpkinseed, and bluegill (Lepomis auritus, L. gibbosus, and L. macrochirus) were injected with benzo[a]pyrene (BaP) as a model compound for common pollutants in urban creeks. Fish were injected with BaP doses of 0, 25 and 50 mg/kg, and after 3 days BaP metabolites in bile, and enzymatic activities of cytochrome P450-1A (CYP1A), UDP-glucuronosyltransferase (UGT) and glutathione S-transferase (GST) were measured. CYP1A activity was significantly increased after BaP dosing in both species groups, but chubs had significantly lower levels than were observed in the dosed sunfish. The UGT activity in unexposed animals was comparable in both species groups, and significantly increased in both groups as a result of BaP dosage. Finally, GST activity was significantly higher in chubs, but did not change in either species group as a result of BaP exposure. There were no significant differences between species within each species group, and the results confirmed that unexposed chubs have much lower CYP1A activity, but a much higher GST activity than unexposed sunfish. The metabolized BaP was excreted in both species groups, but at the time of sampling there were no differences in the amount of BaP metabolites in the bile of dosed animals. The differences in baseline enzyme activity and induction capacity between both species groups are an example of phylogenetically determined differences between fish families, and may explain why chubs are in general more sensitive to exposure to environmental pollutants than sunfish. This conclusion was corroborated by the observation that the highest BaP dose of 50 mg/kg was close to the apparent LC50 for chub, while no mortality was observed in the sunfish at this dose
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