3,775 research outputs found

    Zero gravity tissue-culture laboratory

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    Hardware was developed for performing experiments to detect the effects that zero gravity may have on living human cells. The hardware is composed of a timelapse camera that photographs the activity of cell specimens and an experiment module in which a variety of living-cell experiments can be performed using interchangeable modules. The experiment is scheduled for the first manned Skylab mission

    The 2′-Phosphate of NADP Is Critical for Optimum Productive Binding to 6-Phosphogluconate Dehydrogenase from Candida Utilis

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    Initial velocity studies obtained with alternative dinucleotide substrates for the 6-phosphogluconate dehydrogenase reaction suggest that the 2′-phosphate is critical for the optimum productive binding of the dinucleotide substrate. Initial velocity patterns obtained by varying 6-phosphogluconate at different fixed levels of NAD are nearly parallel with apparent competitive substrate inhibition by 6-phosphogluconate at pH 7 and below but intersect to the left of the ordinate at pH 8 and above. Dead-end inhibition studies indicate that the mechanism is random at all pH values. Data are interpreted in terms of a random mechanism with marked antagonism in the binding of NAD and 6-phosphogluconate at low pH. Deuterium isotope effects on V and V/K for either substrate are equal at pH 8, indicating that the kinetic mechanism is rapid equilibrium random. A decrease in the pH and the subsequent protonation of the active site general base or some other enzyme residue with a similar pK apparently results in the ineffective binding of NAD. The latter suggests either a link between the protonation state of this group and the conformation of the dinucleotide binding site or an interaction between the two

    The 2′-Phosphate of NADP Is Critical for Optimum Productive Binding to 6-Phosphogluconate Dehydrogenase from Candida Utilis

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    Initial velocity studies obtained with alternative dinucleotide substrates for the 6-phosphogluconate dehydrogenase reaction suggest that the 2′-phosphate is critical for the optimum productive binding of the dinucleotide substrate. Initial velocity patterns obtained by varying 6-phosphogluconate at different fixed levels of NAD are nearly parallel with apparent competitive substrate inhibition by 6-phosphogluconate at pH 7 and below but intersect to the left of the ordinate at pH 8 and above. Dead-end inhibition studies indicate that the mechanism is random at all pH values. Data are interpreted in terms of a random mechanism with marked antagonism in the binding of NAD and 6-phosphogluconate at low pH. Deuterium isotope effects on V and V/K for either substrate are equal at pH 8, indicating that the kinetic mechanism is rapid equilibrium random. A decrease in the pH and the subsequent protonation of the active site general base or some other enzyme residue with a similar pK apparently results in the ineffective binding of NAD. The latter suggests either a link between the protonation state of this group and the conformation of the dinucleotide binding site or an interaction between the two

    Toward an index of adaptive personality regulation.

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    The idea that matching personality expression with situational demands is adaptive is implicit in many accounts of personality. Numerous constructs and measures have been posited to address this or similar phenomena. Few have proven adequate. In response, we proposed and tested a novel measurement approach (the APR index) assessing real-time behavior to rate participants’ success in matching personality expression with situational demands, which we denote adaptive personality regulation. An experimental study (N = 88) and an observational study of comedians (N = 203) provided tests of whether the APR index constituted a useful metric of adaptive personality regulation. In both studies, the APR index showed robust psychometric properties; was statistically unique from mean-level personality, self-monitoring, and the general factor of personality expression; and provided incremental concurrent prediction of task/job performance. The results suggest that the APR index provides a useful metric for studying the phenomenon of successfully matching personality expression to situational demands.</p

    An assessment of the benefits of yellow Sigatoka (Mycosphaerella musicola) control in the Queensland Northern Banana Pest Quarantine Area

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    The banana leaf spotting disease yellow Sigatoka is established and actively controlled in Australia through intensive chemical treatments and diseased leaf removal. In the State of Queensland, the State government imposes standards for de-leafing to minimise the risk of the disease spreading in 6 banana pest quarantine areas. Of these, the Northern Banana Pest Quarantine Area is the most significant in terms of banana production. Previous regulations imposed obligations on owners of banana plants within this area to remove leaves from plants with visible spotting on more than 15 per cent of any leaf during the wet season. Recently, this leaf disease threshold has been lowered to 5 per cent. In this paper we examine the likely impact this more-costly regulation will have on the spread of the disease. We estimate that the average net benefit of reducing the diseased leaf threshold is only likely to be $1.4 million per year over the next 30 years, expressed as the annualised present value of tightened regulation. This result varies substantially when the timeframe of the analysis is changed, with shorter time frames indicating poorer net returns from the change in protocols. Overall, the benefit of the regulation change is likely to be minor

    Common Genetic Variant Association with Altered HLA Expression, Synergy with Pyrethroid Exposure, and Risk for Parkinson's Disease: An Observational and Case-Control Study.

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    Background/objectivesThe common non-coding single nucleotide polymorphism (SNP) rs3129882 in HLA-DRA is associated with risk for idiopathic Parkinson's disease (PD). The location of the SNP in the major histocompatibility complex class II (MHC-II) locus implicates regulation of antigen presentation as a potential mechanism by which immune responses link genetic susceptibility to environmental factors in conferring lifetime risk for PD.MethodsFor immunophenotyping, blood cells from 81 subjects were analyzed by qRT-PCR and flow cytometry. A case-control study was performed on a separate cohort of 962 subjects to determine association of pesticide exposure and the SNP with risk of PD.ResultsHomozygosity for G at this SNP was associated with heightened baseline expression and inducibility of MHC class II molecules in B cells and monocytes from peripheral blood of healthy controls and PD patients. In addition, exposure to a commonly used class of insecticide, pyrethroids, synergized with the risk conferred by this SNP (OR = 2.48, p = 0.007), thereby identifying a novel gene-environment interaction that promotes risk for PD via alterations in immune responses.ConclusionsIn sum, these novel findings suggest that the MHC-II locus may increase susceptibility to PD through presentation of pathogenic, immunodominant antigens and/or a shift toward a more pro-inflammatory CD4+ T cell response in response to specific environmental exposures, such as pyrethroid exposure through genetic or epigenetic mechanisms that modulate MHC-II gene expression

    The modelling gap : quantifying the discrepancy in the representation of thermal mass in building simulation

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    Enhanced fabric performance is fundamental to reduce the energy consumption in buildings. Research has shown that the thermal mass of the fabric can be used as a passive design strategy to reduce energy use for space conditioning. Concrete is a high density material, therefore said to have high thermal mass. Insulating concrete formwork (ICF) consists of cast in-situ concrete poured between two layers of insulation. ICF is generally perceived as a thermally lightweight construction, although previous field studies indicated that ICF shows evidence of heat storage effects. There is a need for accurate performance prediction when designing new buildings. This is challenging in particular when using advanced or new methods (such as ICF), that are not yet well researched. Building Performance Simulation (BPS) is often used to predict the thermal performance of buildings. Large discrepancies can occur in the simulation predictions provided by different BPS tools. In many cases assumptions embedded within the tools are outside of the modeller's control. At other times, users are required to make decisions on whether to rely on the default settings or to specify the input values and algorithms to be used in the simulation. This paper investigates the “modelling gap”, the impact of default settings and the implications of the various calculation algorithms on the results divergence in thermal mass simulation using different tools. ICF is compared with low and high thermal mass constructions. The results indicated that the modelling uncertainties accounted for up to 26% of the variation in the simulation predictions

    Game and training load differences in elite junior Australian football

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    Game demands and training practices within team sports such as Australian football (AF) have changed considerably over recent decades, including the requirement of coaching staff to effectively control, manipulate and monitor training and competition loads. The purpose of this investigation was to assess the differences in external and internal physical load measures between game and training in elite junior AF. Twenty five male, adolescent players (mean &plusmn;SD: age 17.6 &plusmn; 0.5 y) recruited from three elite under 18 AF clubs participated. Global positioning system (GPS), heart rate (HR) and rating of perceived exertion (RPE) data were obtained from 32 game files during four games, and 84 training files during 19 training sessions. Matched-pairs statistics along with Cohen\u27s d effect size and percent difference were used to compare game and training events. Players were exposed to a higher physical load in the game environment, for both external (GPS) and internal (HR, Session-RPE) load parameters, compared to in-season training. Session time (d = 1.23; percent difference = 31.4% (95% confidence intervals = 17.4 - 45.4)), total distance (3.5; 63.5% (17.4 - 45.4)), distance per minute (1.93; 33.0% (25.8 - 40.1)), high speed distance (2.24; 77.3% (60.3 - 94.2)), number of sprints (0.94; 43.6% (18.9 - 68.6)), mean HR (1.83; 14.3% (10.5 - 18.1)), minutes spent above 80% of predicted HRmax (2.65; 103.7% (89.9 - 117.6)) and Session-RPE (1.22; 48.1% (22.1 - 74.1)) were all higher in competition compared to training. While training should not be expected to fully replicate competition, the observed differences suggest that monitoring of physical load in both environments is warranted to allow comparisons and evaluate whether training objectives are being met. Key pointsPhysical loads, including intensity, are typically lower in training compared to competition in junior elite Australian football.Monitoring of player loads in team sports should include both internal and external measures.Selected training drills should look to replicate game intensities, however training is unlikely to match the overall physical demands of competition
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