检索结果-南通市图书馆

Evolutionary responses to climate change and contaminants： Evidence and experimental approaches

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2015年第4期61卷 690-701页

作者： david A. KIMBERLY Department of Biology Westminster College 442 Meldrum Science Center Salt Lake City UT 84105 USA Department of Environmental Toxicology The Institute of Environmental and Human Health Texas Tech University 1207 Gilbert Drive Lubbock Texas 79416 USA Environmental Science and Studies Program Towson University 8000 York Rd. Towson MD 21252 USA

A fundamental objective within ecotoxicology lies in understanding and predicting effects of contaminants. This ob- jective is made more challenging when global climate change is considered as an environmental stress that co-occurs with con- taminant exposure. In this multi-stressor context, evolutionary processes are particularly important. In this paper, we consider several non-＂omic＂ approaches wherein evolutionary responses to stress have been studied and discuss those amenable to a mul- tiple stressor context. Specifically, we discuss common-garden designs, artificial and quasi-natural selection, and the estimation of adaptive potential using quantitative genetics as methods for studying evolutionary responses to contaminants and climate change in the absence of expensive molecular tools. While all approaches shed light on potential evolutionary impacts of stressor exposure, they also have limitations. These include logistical constraints, difficulty extrapolating to real systems, and responses tied strongly to specific taxa, populations, and/or testing conditions. The most effective way to lessen these inherent limitations is likely through inclusion of complementary physiological and molecular tools, when available. We believe that an evolutionary context to the study of contaminants and global climate change is a high priority in ecotoxicology and we outline methods that can be implemented by almost any researcher but will also provide valuable insights [Current Zoology 61 （4）： 690-701, 2015].

关键词： Climate change Multiple stressors Adaptation Experimental evolution Quantitative genetics

Regulation of AMP-activated protein kinase by natural and synthetic activators

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2016年第1期6卷 1-19页

作者： david Grahame Hardie Division of Cell Signaling & Immunology College of Life SciencesUniversity of Dundee

The AMP-activated protein kinase(AMPK)is a sensor of cellular energy status that is almost universally expressed in eukaryotic *** it appears to have evolved in single-celled eukaryotes to regulate energy balance in a cell-autonomous manner,during the evolution of multicellular animals its role has become adapted so that it also regulates energy balance at the whole body level,by responding to hormones that act primarily on the *** monitors energy balance at the cellular level by sensing the ratios of AMP/ATP and ADP/ATP,and recent structural analyses of the AMPK heterotrimer that have provided insight into the complex mechanisms for these effects will be *** the central importance of energy balance in diseases that are major causes of morbidity or death in humans,such as type 2 diabetes,cancer and inflammatory disorders,there has been a major drive to develop pharmacological activators of *** such activators have been described,and the various mechanisms by which these activate AMPK will be discussed.A particularly large class of AMPK activators are natural products of plants derived from traditional herbal *** the mechanism by which most of these activate AMPK has not yet been addressed,I will argue that many of them may be defensive compounds produced by plants to deter infection by pathogens or grazing by insects or herbivores,and that many of them will turn out to be inhibitors of mitochondrial function.

关键词： AMP-activated protein kinase Energy balance AMP AMPK activator Mitochondrial function Regulatory mechanism

DNA damage, NF-κB and accelerated aging

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2012年第6期14卷 811-812页

作者： david G Le Couteur david J Handelsman ANZAC Medical Research Institute Sydney 2139 Australia Centre for Education and Research on Ageing (CERA) Concord Hospital and University of Sydney Concord NSW 2139 Australia

The aging process is the major risk factor for disease and disability yet the cel- lular mechanisms for aging are uncertain.

关键词：

The scaling of bite force and constriction pressure in kingsnakes(Lampropeltis getula):Proximate determinants and correlated performance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2017年第2期12卷 121-131页

作者： david A.PENNING Department of Biology University of Louisiana at LafayetteLafayetteLouisianaUSA Department of Biology&Environmental Health Missouri Southern State UniversityJoplinMissouriUSA

Across the diversity of vertebrates,bite force has been studied and suggested to have important ecological and evolutionary ***,there is a notable lineage of vertebrates that use this performance trait yet are missing from the bite-force literature:the *** often rely on biting during prey subjugation and *** snakes bite and hold prey while a constriction coil is formed or while venom is being delivered,or *** use biting exclusively without employing any additional prey-handling *** addition to biting,constriction is an important predation ***,I quantify bite force and constriction pressure in kingsnakes(Lampropeltis getula).Furthermore,I explore the proximate determinants of bite force as well as the relationship between biting and constriction *** force increased linearly with all head and body *** these,head height was the best predictor of bite *** force in kingsnakes was within the range of values reported for lizards,but their relative performance was lower for their head size compared to *** constriction pressure also increased with all body *** and constricting use 2 different parts of the musculoskeletal system and are positively and significantly correlated with one *** work targeting a greater diversity of snakes that rely more heavily on biting may reveal a greater range of bite performance in this diverse and successful vertebrate group.

关键词： bite force constriction pressure ontogeny scaling snake

Predicting total organic carbon from few well logs aided by well-log attributes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum 2023年第2期9卷 166-182页

作者： david A.Wood Lincoln LN59JPDWA Energy LimitedUnited Kingdom

Derivative/volatility well-log attributes from very few commonly recorded well logs can assist in the prediction of total organic carbon(TOC)in shales and tight *** is of value where only limited suites of well logs are recorded,and few laboratory measurements of TOC are conducted on rock *** from two Lower-Barnett-Shale(LBS)wells(USA),including well logs and core analysis is *** demonstrates how well-log attributes can be exploited with machine learning(ML)to generate accurate TOC *** attributes are calculated for gamma-ray(GR),bulk-density(PB)and compressional-sonic(DT)*** in combination with just one of those recorded logs,those attributes deliver more accurate TOC predictions with ML models than using all three recorded *** used in combination with two or three of the recorded logs,the attributes generate TOC prediction accuracy comparable with ML models using five recorded well ***-K-fold-cross-validation analysis reveals that the K-nearest-neighbour algorithm yields the most accurate TOC predictions for the LBS *** extreme-gradient-boosting(XGB)algorithm also performs *** is able to provide information about the relative importance of each well-log attribute used as an input *** facilitates feature selection making it possible to reduce the number of attributes required to generate accurate TOC predictions from just two or three recorded well logs.

关键词： TOC well-Log relationships Log attribute influences Log curve derivatives Moving average volatility Effective attribute combinations

Re-Establishing the Merits of Thermal Maturity and Petroleum Generation Multi-Dimensional Modeling with an Arrhenius Equation Using a Single Activation Energy

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2017年第5期28卷 804-834页

作者： david A.Wood DWA Energy Limited

Thermal maturation and petroleum generation modeling of shales is essential for suc- cessful exploration and exploitation of conventional and unconventional oil and gas plays. For basin- wide unconventional resource plays such modeling, when well calibrated with direct maturity meas- urements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A miscon- ception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite re- flectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index （~TTIARa）, as proposed by Wood （1988）, is flawed. This claim was initially made by Sweeney and Burnham （1990） in promoting their ＂EasyRo＂ method, and repeated by others. This paper dem- onstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ~TTIARR and ＂EasyRo＂ methods that this is not the case. The ~TTIA^R method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies （e.g., ＂EasyRo＂）. Through simple expres- sions the ~TTIAaa method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ~TTIARR method than the ＂EasyRo＂ method. Analysis indicates that the ＂EasyRo＂ method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realisti- cally model observed kerogen behaviour and transformation factors over geologic time scales.

关键词： time-temperature maturity index kerogen activation energies kerogen reaction rates multi-dimensional thermal maturity models petroleum generation versus vitrinite reflectance burial/ thermal history analysis.

Predicting saturated vapor pressure of LNG from density and temperature data with a view to improving tank pressure management

在线全文

学校读者我要写书评

暂无评论

Petroleum 2021年第1期7卷 91-101页

作者： david A.Wood DWA Energy Limited LincolnLN59JPUnited Kingdom

Determining the saturated vapor pressure(SVP)of LNG requires detailed thermodynamic calculations based on compositional *** LNG compositions and SVPs evolve constantly for LNG stored in ***,the SVP of the LNG in a tank influences boil-off rates and tank pressure *** order to make improved tank pressure control decisions it would be beneficial for LNG tank operators to be made more constantly aware of the SVP of the LNG in a *** learning models that accurately estimate LNG SVP from density and temperature inputs offer the potential to provide such information.A dataset of five distinct,internationally traded LNG cargoes is compiled with 305 data records representing a range of temperature and density *** can be used graphically to interpolate LNG ***,two machine learning methods are applied to this dataset to automate the SVP predictions.A simple multi-layer perceptron artificial neural network(MLP-ANN)predicts SVP of the dataset with root mean square error(RMSE)=6.34 kPaA and R^(2)=*** transparent open-box learning network(TOB),a regression-free optimized data matching algorithm predicts SVP of the dataset with RMSE=0.59 kPaA and R^(2)=*** applied to infill unknown LNG compositions the superior TOB method achieves prediction accuracy of RMSE~3kPaA and R^(2)=*** LNG SVP to this level of accuracy is beneficial for tank-pressure management decision making.

关键词： LNG traded Compositions LNG SVP relationships LNG tank pressure influences Boil-off gas rates Optimized data-matching prediction

On relationship between curve numbers and phi indices

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2018年第3期11卷 187-195页

作者： david A.Chin Department of Civil Architectural and Environmental Engineering University of Miami

The curve number and phi(4)-index models each provide a simple one-parameter relationship between storm-event rainfall and runoff. It is shown that the curve number and 4-index models can both be used to segregate the rainfall hyetograph into initial abstraction, retention, and runoff amounts. However, the principal advantages of the 4-index model are that both rainfall distribution and duration can be explicitly taken into account in calculating runoff, and the 4 index is more physically based than the curve number. The quantitative relationship between the curve number and the 4 index is presented and validated with field measurements. Knowing the relationship between the curve number and the 4 index is useful in that it facilitates using the extensive database of curve numbers in the more realistic 4-index model in calculating a runoff hydrograph from a given rainfall hyetograph. It is demonstrated that conventional adjustments to curve numbers can be largely explained by variations in storm duration, which suggests that variable rainfall duration can possibly be an essential factor in accounting for deviations from the median curve number of a catchment.

关键词： Infiltration Rainfall Runoff Curve number 4 index Storm duration

Don’t know what you got till it’s gone:microglial depletion and neurodegeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第10期16卷 1921-1927页

作者： david Graykowski Eiron Cudaback Department of Health Sciences DePaul UniversityChicagoILUSA

In the central nervous system,immunologic surveillance and response are carried out,in large part,by *** resident macrophages derive from myeloid precursors in the embryonic yolk sac,migrating to the brain and eventually populating local tissue prior to blood-brain barrier *** for the duration of lifespan,microglia serve the host as more than just a central arm of innate immunity,also contributing significantly to the development and maintenance of neurons and neural networks,as well as *** critical nature of these varied functions makes the characterization of key roles played by microglia in neurodegenerative disorders,especially Alzheimer’s disease,of paramount *** genetic models and rudimentary pharmacologic approaches for microglial manipulation have greatly improved our understanding of central nervous system health and disease,significant advances in the selective and near complete in vitro and in vivo depletion of microglia for neuroscience application continue to push the boundaries of *** we discuss the research efficacy and utility of various microglial depletion strategies,including the highly effective CSF1R inhibitor models,noteworthy insights into the relationship between microglia and neurodegeneration,and the potential for therapeutic repurposing of microglial depletion and repopulation.

关键词： Alzheimer’s disease clodronate liposomes CSF1R depletion microglia neurodegeneration neuroregeneration repopulation