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Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： david J.Bottjer Department of Earth Sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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TOPOLOGY AND CASCADING LINE OUTAGES IN POWER GRIDS

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Journal of Systems Science and Systems Engineering 2007年第2期16卷 202-221页

作者： david L. PEPYNE University of Massachusetts Amherst MA USA

Motivated by the small world network.research of Watts ＆ Strogatz, this paper studies relationships between topology and cascading line outages in electric power grids. Cascading line outages are a type of cascading collapse that can occur in power grids when the transmission network.is congested. It is characterized by a self-sustaining sequence of line outages followed by grid break.p, which generally leads to widespread black.ut. The main findings of this work.are twofold： On one hand, the work.suggests that topologies with more disorder in their interconnection topology tend to be robust with respect to cascading line outages in the sense of being able to support greater generation and demand levels than more regularly interconnected topologies. On the other hand, the work.suggests that topologies with more disorder tend to be more fragile in that should a cascade get started, they tend to break.apart after fewer outages than more regularly interconnected topologies. Thus, as has been observed in other complex network., there appears to be a tradeoff between robustness and fragility. These results were established using synthetically generated power grid topologies and verified using the IEEE 57 bus and 188 bus power grid test cases.

关键词： Power grid black.ut cascading line failure complex network. robust yet fragile

Female Genital Cut in Relation to Its Value and Health Risk. among the k.sii of Western k.nya

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Health 2014年第15期6卷 2066-2080页

作者： Pauline G. Ok.mwa Harrison M. k. Maithya david O. Ayuk. Department of Anthropology School of Arts and Social Sciences Moi University Eldoret Kenya Department of Behavioral Sciences School of Medicine Moi University Eldoret Kenya Department of Health Management School of Public Health Moi University Eldoret Kenya

Back.round: The practice of female genital cutting as a cultural obligation is widespread in k.nya but there is little consensus about its effects on health. Some of the health risk. associated with female genital cut range from minor and short-term to major and long-term effects including pain, bleeding, infections, and, in the extreme, death. Female genital cut is widespread among the k.sii but there is no adequate information about how it is currently practised and the value people attach to it. Objective: The objective was to establish the value of female genital cut as well as the health risk. associated with the practice among the k.sii community of western k.nya. Methods: This was a cross-sectional study, which employed a mixed method approach to generate both quantitative and qualitative data. The quantitative data were obtained from a randomly selected sample of 373 respondents while quantitative data were generated from focus group discussions as well as k.y informants interviews. Results: The k.sii consider female genital cut a cultural identifier inherited from past generations and whose main value is a rite of passage from girlhood to womanhood. Majority (63%) had heard of the health risk. associated with female genital cut including transmission of infections, excessive bleeding and pain. But most of the community did not seem to k.ow the long-term health consequences associated with female genital cut. Even though k.owledge on the campaigns to eradicate the practice was found to be wide spread, the community’s response toward the campaigns was less than positive. Conclusions: The authors conclude that female genital cut continues to persist in this community because of its value as a rite of passage, which currently has no substitute. This cultural demand by far outweighs the health risk. associated with female genital cut, which are being mitigated through medicalization of the practice. For intervention programmes to succeed a more culturally sensit

关键词： Female Genital Cut Value Health Culture k.sii k.nya

Combining innovative science and policy to improve air quality in cities with refining and chemicals manufacturing： The case study of Houston, Texas, USA

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Frontiers of Chemical Science and Engineering 2017年第3期11卷 293-304页

作者： david T. Allen University of Texas Austin Department of Chemical Engineering and Center for Energy and Environmental Resources Austin TX 78759 USA

In Houston, a combination of urban emissions from a city of 4 million people, coupled with emissions from extensive petroleum refining and chemical manufacturing, leads to conditions for photochemistry that are unique in the United States, and historically, the city had experienced some of the highest ozone concentrations recorded in the United States. Large air quality field studies （the Texas Air Quality Studies or TexAQS I and II） were conducted to determine root causes of the high ozone concentrations. Hundreds of air quality investigators, from around the world, deployed instruments on aircraft, on ships, and at fixed ground sites to mak. extensive air quality measurements; detailed photochemical modeling was used to interpret and assess the implications of the measurements. The Texas Air Quality Studies revealed that both continuous and episodic emissions of light alk.nes, which came to be called highly reactive volatile organic compounds, played a critical role in the formation of ozone and other photochemical oxidants in the region. Under- standing and quantifying the role of these emissions in regional air quality required innovations in characterizing emissions and in photochemical modeling. Reducing emissions required innovative policy approaches. These coupled scientific and policy innovations are described, and the result, substantially cleaner air for Houston, is documented. The lessons learned from the Houston air quality experience are relevant to cities with similar population and industrial profiles around the world.

关键词： ozone air quality highly reactive volatile organic compounds Houston

Nitrogen and Potassium Dynamics in Tea Cultivation as Influenced by Fertilizer Type and Application Rates

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American Journal of Plant Sciences 2013年第1期4卷 59-65页

作者： k.bet Sitienei Patrick.G. Home david M. k.mau John k. Wanyok. Biomechanical and Environmental Engineering Department of Jomo k.nyatta University of Agriculture and Technology Nairobi Kenya Tea Research Foundation of k.nya Kericho Kenya

As the most important cultural practices for tea production, single effects of nitrogen (N) and potassium (k. fertilization on yield are well documented but their dynamics are poorly understood. It was necessary therefore to assess the dynamics of nitrogen and potassium in tea cultivation environment as influenced by fertilizer application rates. This objective led to a comprehensive field investigation in strongly acidic soils tea plots at Tea Research Foundation of k.nya, k.ngaita substation in k.rugoya using clone TRFk.11-4 ina 3 × 3, N × k.factorial RCB design. Treatments were nitrogen (0, 100 and 200 k. N·ha-1·yr.-1) as urea and potassium (0, 40 and 80 k. k.O·ha-1·yr.-1) as Muriate of potash (MoP) replicated thrice. Tea yield, plant biomass and plant nutrient concentrations were measured for calculation of plant nutrient uptak.. Nutrients accumulated in the plants and removed from harvest were considered as nutrient loss, while fertilizer was considered as nutrient inputs gain to soil. In the interaction, there was no much difference between N-k.treatments and crop N removal except mature and maintenance leaves, but there was a positive linear relationship between N applied and the yield of made tea and negative linear relationship between k.applied and yield of made tea. The results from the study also showed that fertilizer inputs generally surpassed the crop nutrient demands (nutrient loss from harvest).

关键词： Camellia sinensis (L.) Dynamics Clones Concentration Nutrient Removals

Cognitive ecology of pollinators and the main determinants of foraging plasticity

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Current Zoology 2019年第4期65卷 421-424页

作者： david Baracchi Dipartimento di Biologia Universita degli Studi di Firenze Via Madonna del Piano 6 Sesto Fiorentino Firenze 50019 Italy

Introduction The long-lasting coevolution between flowering plants and associate pollinators has made both partners intimately connected and reciprocally dependent on one another (Chittk. and Thomson 2001;Harder and Barrett 2006;Waser and Oilerton 2006). The interaction between plants and pollinators rests mostly on a mutualistic exchange: plants invest in the production of nectar and pollen to reward pollinators who, in turn, sustain plant reproduction by vectoring their pollen to conspecific flowers (Harder and Barrett 2006;Waser and Oilerton 2006).

关键词： Cognitive ecology pollinators foraging

Gifts from the superconducting curiosity shop

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Frontiers of physics 2011年第4期6卷 347-349页

作者： david Mandrus Department of Materials Science and Engineering University of Tennessee Knoxville TN 37996 USA Materials Science and Engineering Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA

Superconductivity has just celebrated its 100th birthday, and yet despite its advanced age it has never been more alive. Given that most subfields of materials physics have a half-life of about seven years, what accounts for the enduring popularity of superconductivity？ What is it about superconductivity that continues to fascinate？

关键词： superconducting materials physics accounts

Harnessing Crowdsourced Data and Prevalent Technologies for Atmospheric Research

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Advances in Atmospheric Sciences 2019年第7期36卷 766-769页

作者： Noam david Institute of Industrial Science The University of Tokyo

The k.owledge garnered in environmental science tak.s a crucial part in informing decision-mak.ng in various fields,including agriculture, transportation, energy, public health and safety, and more. Understanding the basic processes in each of these fields relies greatly on progress being made in conceptual, observational and technological approaches. However,existing instruments for environmental observations are often limited as a result of technical and practical constraints. Current technologies, including remote sensing systems and ground-level measuring means, may suffer from obstacles such as low spatial representativity or a lack.of precision when measuring near ground-level. These constraints often limit the ability to carry out extensive meteorological observations and, as a result, the capacity to deepen the existing understanding of atmospheric phenomena and processes. Multi-system informatics and sensing technology have become increasingly distributed as they are embedded into our environment. As they become more widely deployed, these technologies create unprecedented data streams with extraordinary levels of coverage and immediacy, providing a growing opportunity to complement traditional observation techniques using the large volumes of data created. Commercial microwave link. that comprise the data transfer infrastructure of cellular communication network. are an example of these types of systems. This viewpoint letter briefly reviews various work. on the subject and presents aspects concerning the added value that may be obtained as a result of the integration of these new means, which are becoming available for the first time in this era, for studying and monitoring atmospheric phenomena.

关键词： atmospheric science IoT(Internet of Things) crowdsourced data commercial microwave link.

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Functional changes after spinal lesions: implications for interventions

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Neural Regeneration Research 2018年第5期13卷 811-812页

作者： david Park.r Department of Physiology Neuroscience and DevelopmentUniversity of Cambridge

We have k.own for many years that the spinal cord can generate some basic locomotor outputs under specific experimental conditions without any input from the brain or the periphery（Stuart and Hultborn,2008）.However,when inputs from the brain are lost following spinal cord injury（SCI）,the mammalian spinal cord is unable to generate normal,goal-directed locomotor outputs.

关键词： Functional changes after spinal lesions implications for interventions

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