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Phenological Stage, Plant Biomass, and Drought Stress Affect Microbial Biomass and enzyme Activities in the Rhizosphere of enteropogon macrostachyus

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Pedosphere 2019年第2期29卷 259-265页

作者： kevin Z.MGANGA Bahar S.RAZAVI Muhammad SANAULLAH Yakov KUZYAKOV Department of Soil Science of Temperate ecosystems Institute of Soil Science University of G?ttingen Department of Range and Wildlife Sciences South Eastern Kenya University Department of Agricultural Soil Science Institute of Soil Science University of G?ttingen Institute of Soil and environmental Sciences University of AgricultureFaisalabad Institute of environmental Sciences Kazan Federal University

Indigenous grasses have been effectively used to rehabilitate degraded African drylands. Despite their success, studies examining their effects on soil bioindicators such as microbial biomass carbon(C) and enzyme activities are scarce. This study elucidates the effects of drought stress and phenological stages of a typical indigenous African grass, enteropogon macrostachyus, on microbial biomass and enzyme activities(β-glucosidase, cellobiohydrolase, and chitinase) in the rhizosphere soil. enteropogon macrostachyus was grown under controlled conditions. Drought stress(partial watering) was simulated during the last 10 d of plant growth, and data were compared with those from optimum moisture conditions. The rhizosphere soil was sampled after 40 d(seedling stage), 70 d(elongation stage), and 80 d(simulated drought stress). A high root:shoot ratio at seedling stage compared with elongation and reproduction stages demonstrated that e. macrostachyus invested more on root biomass in early development, to maximise the uptake of nutrients and water. Microbial biomass and enzyme activities increased with root biomass during plant growth. Ten-day drought at reproduction stage increased the microbial biomass and enzyme activities, accompanying a decrease in binding affinity and catalytic efficiency. In conclusion, drought stress controls soil organic matter decomposition and nutrient mobilization, as well as the competition between plant and microorganisms for nutrient uptake.

关键词： African grass catalytic efficiency cellobiohydrolase chitinase β-glucosidase nutrient uptake optimum moisture soil bioindicators

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Calcium signaling and T-type calcium channels in cancer cell cycling

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World Journal of Gastroenterology 2008年第32期14卷 4984-4991页

作者： James T Taylor Xiang-Bin Zeng Jonathan e Pottle kevin Lee Alun R Wang Stephenie G Yi lennifer A S Scruggs Suresh S Sikka Ming Li Department of Pharmacology Tulane University Health Sciences Center New Orleans LA 70112 United States Department of Urology Tulane University Health Sciences Center New Orleans LA 70112 United States Department of Physiology Tulane University Health Sciences Center New Orleans LA 70112 United States Department of Pathology Tulane University Health Sciences Center New Orleans LA 70112 United States

Regulation of intracellular calcium is an important signaling mechanism for cell proliferation in both normal and cancerous cells. In normal epithelial cells, free calcium concentration is essential for cells to enter and accomplish the S phase and the M phase of the cell cycle. In contrast, cancerous cells can pass these phases of the cell cycle with much lower cytoplasmic free calcium concentrations, indicating an alternative mechanism has developed for fulfilling the intracellular calcium requirement for an increased rate of DNA synthesis and mitosis of fast replicating cancerous cells. The detailed mechanism underlying the altered calcium loading pathway remains unclear; however, there is a growing body of evidence that suggests the T-type Ca2+ channel is abnormally expressed in cancerous cells and that blockade of these channels may reduce cell proliferation in addition to inducing apoptosis. Recent studies also show that the expression of T-type Ca2+ channels in breast cancer cells is proliferation state dependent, i.e. the channels are expressed at higher levels during the fast-replication period, and once the cells are in a non-proliferation state, expression of this channel isminimal. Therefore, selectively blocking calcium entry into cancerous cells may be a valuable approach for preventing tumor growth. Since T-type Ca2+ channels are not expressed in epithelial cells, selective T-type Ca2+ channel blockers may be useful in the treatment of certain types of cancers.

关键词： T-type calcium channels Cancer Cellcycle Calcium

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MINAR1 is a Notch2-binding protein that inhibits angiogenesis and breast cancer growth

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Journal of Molecular Cell Biology 2018年第3期10卷 195-204页

作者： Rachel Xi-Yeen Ho Rosana D. Meyer kevin B. Chandler esma ersoy Michael Park Philip A. Bondzie Nima Rahimi Huihong Xu Catherine e. Costello Nader Rahimi Department of Pathology School of Medicine Boston University Medical Campus Boston MA 02118 USA Department of Biochemistry and Center for Biomedical Mass Spectrometry School of Medicine Boston University Medical Campus Boston MA 02118 USA

Intrinsically disordered proteins （IDPs）/intrinsicaUy unstructured proteins are characterized by the lack of fixed or stable tertiary structure, and are increasingly recognized as an important class of proteins with major roles in signal transduction and transcriptional regulation. In this study, we report the identification and functional characterization of a previously uncharacterized protein （UPFO258/KIAA1024）, major intrinsically disordered Notch2-associated receptor 1 （MINAR1）. While MINAR1 carries a single transmembrane domain and a short cytoplasmic domain, it has a large extraceUular domain that shares no similarity with known protein sequences. Uncharacteristically, MINAR1 is a highly IDP with nearly 70% of its amino acids sequences unstructured. We demonstrate that MINAR1 physically interacts with Notch2 and its binding to Notch2 increases its stability and function. MINAR1 is widely expressed in various tissues including the epithelial cells of the breast and endothelial cells of blood vessels. MINAR1 plays a negative role in angioganesis as it inhibits angioganesis in cell culture and in mouse matrigal plug and zebraflsh anglo- genesis models. Furthermore, while MINAR1 is highly expressed in the normal human breast, its expression is significantly down- regulated in advanced human breast cancer and its re-expression in breast cancer cells inhibited tumor growth. Our study demonstrates that MINAR1 is an IDP that negatively regulates angioganesis and growth of breast cancer cells.

关键词： intrinsically disordered proteins Notch2 angiogenesis breast cancer MINAR1

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Methods and approaches to disease mechanisms using systems kinomics

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Synthetic and Systems Biotechnology 2018年第1期3卷 34-43页

作者： Alicia Berard Andrea Kroeker Peter McQueen kevin M.Coombs Department of Medical Microbiology University of ManitobaWinnipegR3E 0J9Canada JC Wilt Infectious Diseases Research Centre Public Health Agency of CanadaWinnipegCanada Canadian Food Inspection Agency WinnipegCanada

All cellular functions,ranging from regular cell maintenance and homeostasis,specialized functions specific to cellular types,or generating responses due to external stimulus,are mediated by proteins within the *** of these proteins allows the cell to alter its behavior under different circumstances.A major mechanism of protein regulation is utilizing protein kinases and phosphatases;enzymes that catalyze the transfer of phosphates between substrates[1].Proteins involved in phosphate signaling are well studied and include kinases and phosphatases that catalyze opposing reactions regulating both structure and function of the *** is the study of kinases,phosphatases and their targets,and has been used to study the functional changes in numerous diseases and infectious diseases with aims to delineate the cellular functions *** the phosphate signaling pathways changed by certain diseases or infections can lead to novel therapeutic ***,a daunting 518 putative protein kinase genes have been identified[2],indicating that this protein family is very large and *** which enzymes are specific to a particular disease can be a laborious *** this review,we will provide information on large-scale systems biology methodologies that allow global screening of the kinome to more efficiently identify which kinase pathways are pertinent for further study.

关键词： diseases homeostasis utilizing

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Cash transfer during the COVID-19 pandemic:a multicentre,randomised controlled trial

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Family Medicine and Community Health 2021年第4期9卷 50-56,I0016-I0021页

作者： Navindra Persaud kevin e Thorpe Michael Bedard Stephen W Hwang Andrew Pinto Peter Jüni Bruno R da Costa 无 Department of Family and Community Medicine University of TorontoTorontoOntarioCanada MAP Centre for Urban Health Solutions Li Ka Shing Knowledge InstituteSt.Michael’s HospitalUniversity of TorontoTorontoOntarioCanada Department of Family and Community Medicine St Michael’s HospitalTorontoOntarioCanada Institute of Health Policy Managementand EvaluationUniversity of TorontoTorontoOntarioCanada Dalla Lana School of Public Health University of TorontoTorontoOntarioCanada Applied Health Research Centre Unity Health TorontoSt Michael's HospitalTorontoOntarioCanada Department of Family Medicine Northern Ontario School of MedicineThunder BayOntarioCanada Department of Medicine St Michael's HospitalUnity Health TorontoTorontoOntarioCanada Department of Medicine University of TorontoTorontoOntarioCanada Institute of Primary Health Care(BIHAM) University of BernTorontoSwitzerland DISTANSe COVID-19(Direct Income SupporT and Advice Negating Spread of epidemic COVID-19:a randomized controlled trial)study team

Objective To evaluate the effect of a one-time cash transfer of$C1000 in people who are unable to physically distance due to insufficient *** Open-label,multi-centre,randomised superiority *** Seven primary care sites in Ontario,Canada;six urban sites associated with ***’s Hospital in Toronto and one in Manitoulin *** 392 individuals who reported trouble affording basic necessities due to disruptions related to *** After random allocation,participants either received the cash transfer of$C1000(n=196)or physical distancing guidelines alone(n=196).Main outcome measures The primary outcome was the maximum number of symptoms consistent with COVID-19 over 14 *** outcomes were meeting clinical criteria for COVID-19,SARS-CoV-2 presence,number of close contacts,general health and ability to afford basic *** The primary outcome of number of symptoms reported by participants did not differ between groups after 2 weeks(cash transfer,mean 1.6 vs 1.9,ratio of means 0.83;95%CI 0.56 to 1.24).There were no statistically significant effects on secondary outcomes of the meeting COVID-19 clinical criteria(7.9%vs 12.8%;risk difference−0.05;95%CI−0.11 to 0.01),SARS-CoV-2 presence(0.5%vs 0.6%;risk difference 0.0095%CI−0.02 to 0.02),mean number of close contacts(3.5 vs 3.7;rate ratio 1.10;95%CI 0.83 to 1.46),general health very good or excellent(60%vs 63%;risk difference−0.0395%CI−0.14 to 0.08)and ability to make ends meet(52%vs 51%;risk difference 0.0195%CI−0.10 to 0.12).Conclusions A single cash transfer did not reduce the COVID-19 symptoms or improve the ability to afford *** studies are needed to determine whether some groups may benefit from financial supports and to determine if a higher level of support is *** registration number NCT04359264.

关键词： Canada centre random

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冷热通道气流遏制对数据中心温度和效率的影响(上)

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数据中心建设+ 2020年第4期 31-37页

作者： John Niemann kevin brown Victor Avelar 施耐德电气-数据中心科研中心

冷热通道气流遏制均可显著提高传统数据中心制冷系统的可预测性和效率。尽管两种方式均可消除冷、热气流的混合,但在实际的实施和运营中两者仍存在差别,而且这种差别将对作业环境、PUe和节能冷却模式运行的时间产生显著的影响。采用热... 详细信息

冷热通道气流遏制均可显著提高传统数据中心制冷系统的可预测性和效率。尽管两种方式均可消除冷、热气流的混合,但在实际的实施和运营中两者仍存在差别,而且这种差别将对作业环境、PUe和节能冷却模式运行的时间产生显著的影响。采用热通道气流遏制系统的策略会比采用冷通道气流遏制的策略多取得43%的节能效果,由此在年度PUe上会有15%的改善。本文将对这两种策略进行研究,并着重阐述为什么热通道气流遇制系统对于新建数据中心是最佳实践。

关键词：数据中心可预测性热气流制冷系统冷却模式热通道最佳实践两种策略

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(In) consistency of air/sea heat flux estimates,ocean heat uptake anomalies and top of atmosphere radiation budgets

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engineering Sciences 2014年第2期12卷 29-35,40页

作者： Drijfhout Sybren S Trenberth kevin e Large William G National Oceanography Centre National Center for Atmospheric Research

This paper introduces the consistency between top of atmosphere(TOA) imbalances and ocean heat uptake,and the inconsistency between ocean heat uptake estimates and flux climatologies,and then gives some recommendation... 详细信息

关键词： heat flux ocean heat uptake radiation budget

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Vanishing bile duct syndrome in human immunodeficiency virus infected adults:A report of two cases

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World Journal of Gastroenterology 2013年第1期19卷 115-121页

作者： Ana Paula Oppenheimer Christopher Koh Mary McLaughlin John C Williamson Thomas D Norton Jennifer Laudadio Theo Heller David e Kleiner kevin P High Caryn G Morse Section of Infectious Diseases Department of MedicineWake Forest School of MedicineWinston-SalemNC 27109-7205United States Liver Diseases Branch National Institute of DiabetesDigestive and Kidney DiseasesNational Institutes of Health Clinical CenterBethesdaMD 20892-1403United States Laboratory of Immunoregulation National Institute of Allergy and Infectious DiseasesNational Institutes of Health Clinical CenterBethesdaMD 20892-1403United States Division of Infectious Diseases and Immunology Department of MedicineNew York University School of MedicineNew YorkNY 10016United States Laboratory of Pathology Wake Forest School of MedicineWinston-SalemNC 27109-7205United States Laboratory of Pathology National Cancer InstituteNational Institutes of Health Clinical CenterBethesdaMD 20892-1403United States Department of Critical Care Medicine National Institutes of Health Clinical CenterBethesdaMD 20892-1403United States

Vanishing bile duct syndrome(VBDS) is a group of rare disorders characterized by ductopenia,the progressive destruction and disappearance of intrahepatic bile ducts leading to *** in association with medications,autoimmune disorders,cancer,transplantation,and infections,the specific mechanisms of disease are not *** date,only 4 cases of VBDS have been reported in human immunodeficiency virus(HIV) infected *** report 2 additional cases of HIV-associated VBDS and review the features common to the HIV-associated *** includes hyperbilirubinemia,normal liver imaging,and negative viral and autoimmune hepatitis *** HIV-infected subjects,VBDS occurred at a range of CD4+ T-cell counts,in some cases following initiation or change in antiretroviral *** was associated with two cases;nevirapine,antibiotics,and viral co-infection were suggested as etiologies in the other *** HIV-positive patients with progressive cholestasis,early identification of VBDS and referral for transplantation may improve outcomes.

关键词： Human immunodeficiency virus Antiretroviral therapy Vanishing bile duct syndrome Ductopenia Liver biopsy

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Mechanisms for the hiatus in global warming

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engineering Sciences 2014年第2期12卷 41-42,74页

作者： Ka-Kit Tung Rong Zhang kevin e Trenberth Department of Applied Mathematics University of Washington Geophysical Fluid Dynamics Laboratory National Oceanic and Atmospheric Administration National Center for Atmospheric Research

The observed global mean temperature is the highest on record for the past decade but has plateaued to form an apparent"hiatus"in global temperature rise,with an almost zero short-term trend. Several speakers presente... 详细信息

关键词： hiatus global warming mechanisms

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eDA: an enhanced dual-active algorithm for location privacy preservation in mobile P2P networks

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Journal of Zhejiang University-Science C(Computers and electronics) 2013年第5期14卷 356-373页

作者： Yan-zhe CHe kevin CHIeW Xiao-yan HONG Qiang YANG Qin-ming He College of Computer Science and Technology Zhejiang University School of engineering Tan Tao University Department of Computer Science University of Alabama College of electrical engineering Zhejiang University

Various solutions have been proposed to enable mobile users to access location-based services while preserving their location privacy. Some of these solutions are based on a centralized architecture with the participation of a trustworthy third party, whereas some other approaches are based on a mobile peer-to-peer (P2P) architecture. The former approaches suffer from the scalability problem when networks grow large, while the latter have to endure either low anonymization success rates or high communication overheads. To address these issues, this paper deals with an enhanced dual-active spatial cloaking algorithm (eDA) for preserving location privacy in mobile P2P networks. The proposed eDA allows mobile users to collect and actively disseminate their location information to other users. Moreover, to deal with the challenging characteristics of mobile P2P networks, e.g., constrained network resources and user mobility, eDA enables users (1) to perform a negotiation process to minimize the number of duplicate locations to be shared so as to significantly reduce the communication overhead among users, (2) to predict user locations based on the latest available information so as to eliminate the inaccuracy problem introduced by using some out-of-date locations, and (3) to use a latest-record-highest-priority (LRHP) strategy to reduce the probability of broadcasting fewer useful locations. extensive simulations are conducted for a range of P2P network scenarios to evaluate the performance of eDA in comparison with the existing solutions. experimental results demonstrate that the proposed eDA can improve the performance in terms of anonymity and service time with minimized communication overhead.

关键词： Location-based service Privacy preservation Spatial cloaking Mobile peer-to-peer networks

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