3,314 research outputs found

    Estimating the characteristics of runoff inflow into Lake Gojal in ungauged, highly glacierized upper Hunza River Basin, Pakistan

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    Motivated by the potential flood outburst of Lake Gojal in the ungauged highly glacierized (27%) upper Hunza River Basin (HRB) in Pakistan that was dammed by a massive landslide on 4 January 2010, we attempt to analyze the characteristics of water inflow to the lake employing remote sensing data, two hydrological models, and sparsely observed data. One of the models (Model I) is a monthly degree-day model, while another (Model II) is the variable infiltration capacity (VIC) model. The mixture of glacier runoff output from Model I and runoff over unglacierized areas calculated by Model II has a similar seasonal variation pattern as that estimated from data recorded at a downstream station. This suggests that glacier runoff is the main source (87%) of runoff inflow into the lake. A sensitivity analysis suggests that the water inflow to the lake is highly sensitive to an increase in air temperature. Runoff in May is predicted to sharply increase by 15% to more than two-fold if the air temperature increases by 1 to 7, but it is predicted to increase only from 9% to 34% if the precipitation increases by 10% to 40%. The results suggested that the water inflow into Lake Gojal will not sharply rise even if there is heavy rain, and it needs to be in caution if the air temperature sharply increases. Analysis on long-term air temperature record indicates that the water inflow into the lake in May 2010 was probably less than average owing to the relatively low air temperature. Consequently, the flood outburst did not occur before the completion of the spillway on 29 May 2010. © 2013 China University of Geosciences and Springer-Verlag Berlin Heidelberg

    Influence of environmental factors during seed development and after full-ripeness on pre-harvest sprouting in wheat

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    Results on environmental and genotypic factors influencing preharvest sprouting of wheat are summarized. Other possible areas where additional research is needed is suggested

    Computer Modeling: The Adjunct Micro Technique for Lipids

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    Chemistry by computer provides access to microsystem information not readily achieved by other means. Simple computational analysis of saturated triglyceride polymorphism by molecular mechanics within constraints provided by X-ray data show that polymethylene interactions determine hydrocarbon crystal properties when they account for more than 60 percent of the total molecular interaction energy. Modeling predicts multiple , nearly equivalent, a -form triglycerides and a -form character in liquid near-crystalline triglycerides. Symmetrical molecules pack better than asymmetric molecules in a-form configurations and transform readily to 13\u27forms if activated sufficiently to disrupt lateral chain interaction and allow dimensional displacements during transformation. The formation of P\u27-forms, thought important for quality in certain foods, may depend on controlling both the configuration of a-form precursors and the sequence of molecular events during the transformation

    Climate model bias correction and the role of timescales

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    It is well known that output from climate models cannot be used to force hydrological simulations without some form of preprocessing to remove the existing biases. In principle, statistical bias correction methodologies act on model output so the statistical properties of the corrected data match those of the observations. However the improvements to the statistical properties of the data are limited to the specific time scale of the fluctuations that are considered. For example, a statistical bias correction methodology for mean daily values might be detrimental to monthly statistics. Also, in applying bias corrections derived from present day to scenario simulations, an assumption is made of persistence of the bias over the largest timescales. We examine the effects of mixing fluctuations on different time scales and suggest an improved statistical methodology, referred to here as a cascade bias correction method, that eliminates, or greatly reduces, the negative effects

    TDP-43 and FUS mislocalization in VCP mutant motor neurons is reversed by pharmacological inhibition of the VCP D2 ATPase domain

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    RNA binding proteins have been shown to play a key role in the pathogenesis of amyotrophic lateral sclerosis (ALS). Mutations in valosin-containing protein (VCP/p97) cause ALS and exhibit the hallmark nuclear-to-cytoplasmic mislocalization of RNA binding proteins (RBPs). However, the mechanism by which mutations in VCP lead to this mislocalization of RBPs remains incompletely resolved. To address this, we used human-induced pluripotent stem cell-derived motor neurons carrying VCP mutations. We first demonstrate reduced nuclear-to-cytoplasmic ratios of transactive response DNA-binding protein 43 (TDP-43), fused in sarcoma/translocated in liposarcoma (FUS) and splicing factor proline and glutamine rich (SFPQ) in VCP mutant motor neurons. Upon closer analysis, we also find these RBPs are mislocalized to motor neuron neurites themselves. To address the hypothesis that altered function of the D2 ATPase domain of VCP causes RBP mislocalization, we used pharmacological inhibition of this domain in control motor neurons and found this does not recapitulate RBP mislocalization phenotypes. However, D2 domain inhibition in VCP mutant motor neurons was able to robustly reverse mislocalization of both TDP-43 and FUS, in addition to partially relocalizing SFPQ from the neurites. Together these results argue for a gain-of-function of D2 ATPase in VCP mutant human motor neurons driving the mislocalization of TDP-43 and FUS. Our data raise the intriguing possibility of harnessing VCP D2 ATPase inhibitors in the treatment of VCP-related ALS

    E2F8 is a nonreceptor activator of heterotrimeric G proteins

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    BACKGROUND: Heterotrimeric G proteins are important for numerous signaling events in eukaryotes, serving primarily to transduce signals that are initiated by G protein-coupled receptors. It has recently become clear that nonreceptor activators can regulate the level of heterotrimeric G protein signaling and, in some cases, drive cycles of receptor-independent G protein activation. In this study, we used a yeast expression cloning strategy to identify novel nonreceptor activators of heterotrimeric G proteins in a human adipocyte cDNA library. RESULTS: The human transcription factor E2F8 was found to activate heterotrimeric G proteins, suggesting a specific biological role for this recently described member of the E2F family. Epistasis studies showed that E2F8 acted at the level of G proteins and was specific for Gα(i )over Gpa1. E2F8 augmented receptor-driven signaling, but also activated G proteins in the absence of a receptor. The GTPase-activating protein RGS4 antagonized the effect of E2F8, showing that E2F8's effect on Gα involved nucleotide turnover. The entire E2F8 protein was required for full activity, but the majority of the signaling activity appeared to reside in the first 200 residues. CONCLUSION: In yeast, E2F8 is a guanine nucleotide exchange factor (GEF) for the α subunit of heterotrimeric G proteins. The molecular mechanism and biological significance of this effect remain to be determined

    A simple plating assay for aneuploidy in sexual progeny of Neurospora crassa, and a new allele of mei-1.

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    We developed a simple ascospore plating assay for aneuploidy, based on identifying disomic progeny that inherit two independently selectable mtr alleles. We validated the assay using a known meiotic mutant, mei-2. We used this assay to demonstrate that elevated frequencies of aneuploidy previously reported to be associated with reduced DNA methylation were not, in fact, due to the methylation deficiencies. A new allele of the mei-1 gene was responsible for some of the high aneuploidy

    Seasonal characteristics of the relationship between daily precipitation intensity and surface temperature

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    Past studies have argued that the intensity of extreme precipitation events should increase exponentially with temperature. This argument is based on the principle that the atmospheric moisture holding capacity increases according to the Clausius-Clapeyron equation and on the expectation that precipitation formation should follow accordingly. We test the latter assumption by investigating to what extent a relation with temperature can be observed intraseasonally in present-day climate. For this purpose, we use observed and simulated daily surface temperature and precipitation over Europe. In winter a general increase in precipitation intensity is indeed observed, while in summer we find a decrease in precipitation intensity with increasing temperature. We interpret these findings by making use of model results where we can distinguish separate precipitation types and investigate the moisture content in the atmosphere. In winter, the Clausius-Clapeyron relationship sets a limit to the increase in the large-scale precipitation with increasing temperature. Conversely, in summer the availability of moisture, and not the atmosphere's capacity to hold this moisture, is the dominant factor at the daily timescale. For convective precipitation, we find a peak like structure which is similar for all subregions, independent of the mean temperature, contrary to large-scale precipitation which has a more monotonic dependence on temperature
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