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CD4 and CD8 T cells mediate distinct lethal meningoencephalitis in mice challenged with Tacaribe arenavirus

Cellular & Molecular Immunology 2017年第1期14卷 90-106页

作者： derek dc ireland Cecilia Tami Joao Pedras-Vasconcelos Daniela Verthelyi Division of Biologics Review and Research-III Office of Biotechnology Center for Drug Evaluation and Research Food and Drug Administration Silver Spring MD 20993 USA

Neonates are at increased risk of viral encephalopathies that can result in neurological dysfunction, seizures, permanent disability and even death. The neurological damage results from the combined effect of the virus and the immune response it elicits, thus finding tools to facilitate viral clearance from central nervous system （CNS） while minimizing neuron damage remains a critical challenge. Neonatal mice inoculated intraperitoneally with Tacaribe virus （TCRV） develop seizures, hindlimb paralysis and death within 15 days of inoculation. TCRV localizes to the CNS within days of challenge, primarily infecting astrocytes in the cerebellum and brain stem. We show that infection leads to inflammation, T cell and monocyte infiltration into the cerebellar parenchyma, apoptosis of astrocytes, neuronal degeneration and loss of Purkinje cells. Infiltrating antigen-specific T cells fail to clear the virus but drive the disease, as T-cell-deficient CD3ε KO mice survive TCRV infection with minimal inflammation or clinical manifestations despite no difference in CNS viral loads in comparison with T-cell sufficient mice. CD8＋ T cells drive the pathology, which even in the absence of CD4＋ T-cell help, infiltrate the parenchyma and mediate the apoptotic loss of cerebellar astrocytes, neurodegeneration and loss of Purkinje cells resulting in loss of balance, paralysis and death. CD4＋ T cells are also pathogenic inducing gliosis and inflammation in the cerebellum and cerebrum that are associated with wasting and death several weeks after CD4＋ T-cell transfer. These data demonstrate distinct pathogenic effects of CD4＋ and CD8＋ T cells and identify them as possible therapeutic targets.

关键词： Astrocytes CD4 T cells CD8 T cells encephalitis Purkinje cells virus

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Maximum Power Point Tracking Using the Incremental Conductance Algorithm for PV Systems Operating in Rapidly Changing Environmental Conditions

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Smart Grid and Renewable Energy 2022年第5期13卷 89-108页

作者： derek Ajesam Asoh Brice Damien Noumsi Edwin Nyuysever Mbinkar Laboratoire de Génie Electrique Mécatronique et Traitement du Signal ENSPY University of Yaounde I Yaounde Cameroon Department of Electrical/Electronic Engineering NAHPI University of Bamenda Bamenda Cameroon Higher Technical Teacher Training College (HTTTC) University of Bamenda Bamenda Cameroon Department of Electrical/Electronics Engineering Nigeria Army College of Environmental Studies and Technology (NACEST) Makurdi Nigeria

Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV panels operate at its maximum power point (MPP) entails power losses;resulting in high cost since more panels will be required to provide specified energy needs. To achieve high efficiency and low cost, MPPT has therefore become an imperative in PV systems. In this study, an MPP tracker is modeled using the IC algorithm and its behavior under rapidly changing environmental conditions of temperature and irradiation levels is investigated. This algorithm, based on knowledge of the variation of the conductance of PV cells and the operating point with respect to the voltage and current of the panel calculates the slope of the power characteristics to determine the MPP as the peak of the curve. A simple circuit model of the dc-dc boost converter connected to a PV panel is used in the simulation;and the output of the boost converter is fed through a 3-phase inverter to an electricity grid. The model was simulated and tested using MATLAB/Simulink. Simulation results show the effectiveness of the IC algorithm for tracking the MPP in PV systems operating under rapidly changing temperatures and irradiations with a settling time of 2 seconds.

关键词： Modeling Simulation PV System Maximum Power Point Tracking (MPPT) Incremental Conductance Algorithm MATLAB/Simulink

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Specialized digestive adaptations within the hindgut of a colobine monkey

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The Innovation 2022年第2期3卷 103-109页

作者： Rui Liu Katherine Amato Rong Hou Andres Gomez derek W.Dunn Jun Zhang Paul A.Garber Colin A.Chapman Nicoletta Righini Gang He Gu Fang Yuhang Li Baoguo Li Songtao Guo Shaanxi Key Laboratory for Animal Conservation School of Life SciencesNorthwest UniversityXi’an 710069China Department of Anthropology Northwestern UniversityEvanstonIL 60208USA Department of Animal Science University of Minnesota Twin CitiesSt.PaulMN 55455USA Department of Anthropology and Program in EcologyEvolution and Conservation BiologyUniversity of Illinois at Urbana-ChampaignUrbana-ChampaignIL 61801USA Center for the Advanced Study of Human Paleobiology Department of AnthropologyThe George Washington UniversityWashingtonDC 20037USA School of Life Sciences University of KwaZulu-NatalScottsvillePietermaritzburg 3209South Africa Instituto de Investigaciones en Comportamiento Alimentario y Nutrición(IICAN) Universidad de Guadalajara49000 Ciudad GuzmánJaliscoMexico

In mammal herbivores,fiber digestion usually occurs predominantly in either the foregut or the hindgut.Reports of mechanisms showing synergistic function in both gut regions for the digestion of fiber and other nutrients in wild mammals are rare because it requires integrative study of anatomy,physiology,and gut microbiome.Colobine monkeys(Colobinae)are folivorous,with high-fiber foods fermented primarily in their foreguts.

关键词： anatomy gut primarily

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Design of a Photovoltaic Mini-Grid System for Rural Electrification in Sub-Saharan Africa

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Energy and Power Engineering 2021年第3期13卷 91-110页

作者： Edwin N. Mbinkar derek A. Asoh Roger Tchuidjan Amadou Baldeh Laboratoire de Genie Electrique Mecatronique et Traitement du Signal ENSPY University of Yaounde I Yaounde Cameroon NAHPI/HTTTC University of Bamenda Bamenda Cameroon Gambia Techinical Training Instisitute Banjul the Gambia

This paper presents a detailed design of a photovoltaic (PV) system for use in the rural electrification of remote settlements that are far off from the electricity grid. Since investment in building transmission lines from the grid to these localities is not viable, a good solution is an installation in these areas of standalone photovoltaic systems. The design process comprises the choice and dimensioning of the solar panels, the battery storage, DC-AC inverter, and mini transmission grid to the different homes. The design is for a 15 kW PV system including an economic evaluation and analysis using Hybrid Optimization of Multiple Energy Resources (HOMER) software. Data on the average monthly solar radiation and temperature were obtained from various sources, including, Photovoltaic Geographical Information System (PVGIS) for Africa. From this data the study area receives a monthly average solar insolation of 6.16 kWh/m2/day with the worst month being August with 5.22 kWh/m2/day. The total daily electrical energy consumption is estimated to be about 72.525 kWh. Simulation results using HOMER software shows that the overall capital cost of the PV system components is $122,337, a replacement cost of $12,889 and an operation and maintenance cost of $29,946 over 10years. A financial analysis of the system showed that the design was both viable and sustainable with low maintenance cost.

关键词： Photovoltaic Solar Radiation Rural Electrification Mini-Grid System Dimensioning

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中国西部绿色发展概念框架

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中国人口·资源与环境 2013年第10期23卷 1-7页

作者：刘纪远邓祥征刘卫东李海英 Robyn KRUK derek THOMPSON Peishen WANG Xuemei BAI 中国科学院地理科学与资源研究所北京100101 中国科学院农业政策研究中心北京100101 中国环境与发展国际合作委员会秘书处澳大利亚全国心理健康委员会加拿大皇家路大学世界银行美国华盛顿dc20433 澳大利亚国立大学

综合绿色发展的国际经验,以自然资本、经济资本、社会资本与人力资本四大资本为核心,提出了中国西部地区绿色发展概念框架。中国西部地区绿色发展概念框架是以"发展中促转变,转变中谋发展"的良性循环发展原则为指导原则,分析西部地区社... 详细信息

综合绿色发展的国际经验,以自然资本、经济资本、社会资本与人力资本四大资本为核心,提出了中国西部地区绿色发展概念框架。中国西部地区绿色发展概念框架是以"发展中促转变,转变中谋发展"的良性循环发展原则为指导原则,分析西部地区社会经济发展及生态环境和自然资源保护两个方面在发展过程中相互促进和制约的关系,并根据西部地区当前经济资本、环境资本、社会资本以及人力资本数量,通过政府适当干预,如区域规划、区内调整,最终实现社会经济与生态环境和自然资源相协调的绿色发展。该框架综合考虑了中国西部在绿色发展道路上特有挑战与机遇,阐明了社会经济发展与资源环境承载力之间的相互作用机制,明确了中国西部地区"生态友好、社会包容和内生增长"的绿色发展目标。最后,本文针对该绿色发展框架提出了中国西部地区绿色发展的政策建议:提出"西部地区绿色发展战略"是当前西部地区绿色发展进程中最为迫切的需求,中央政府应当尽快制定和实施"西部地区绿色发展战略",同时西部地区政府在省级和地方层面将保护中国西部生态环境与区域扶贫开发相结合,加大对以提升西部地区人力资本为目的的各类工程的投入,强化区域绿色基础建设和生态服务供给,缓解西部地区贫困,提升区域绿色发展进程的速度和质量;开展财政体制机制改革,以提高各级财政资金的使用效率;结合各省发展需求与条件实施以生态城市为发展目标的可持续城镇化发展模式,制定差异化的城镇化发展战略;在西部地区重点和限制开发区尤其是贫困集中和区域发展潜力较大地区,鼓励具有区域特色的新型绿色产业的发展。在发展过程中不断加强制度创新以引导长期绿色发展。

关键词：绿色发展概念框架自然资本人力资本内生增长西部地区

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COVID-19 among African Americans and Hispanics:Does gastrointestinal symptoms impact the outcome?

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World Journal of Clinical Cases 2021年第28期9卷 8374-8387页

作者： Hassan Ashktorab Adeleye Folake Antonio Pizuorno Gholamreza Oskrochi Philip Oppong-Twene NuriTamanna Maryam Mehdipour Dalivand Lisa N Umeh Esther S Moon Abdoul Madjid Kone Abigail Banson Cassandra Federman Edward Ramos Eyitope Ola Awoyemi Boubini Jones Wonni Eric Otto Guttu Maskalo Alexandra Ogando Velez Sheldon Rankine Camelita Thrift Chiamaka Ekwunazu derek Scholes LakshmiGayathri Chirumamilla Mohd Elmugtaba Ibrahim Brianna Mitchell Jillian Ross Julencia Curtis Rachel Kim Chandler Gilliard Joseph Mathew Adeyinka Laiyemo Angesum Kibreab Edward Lee Zaki Sherif Babak Shokrani Farshad Aduli Hassan Brim Department of Medicine Gastroenterology Division and Cancer CenterHoward University College of MedicineWashingtonDC 20060United States Faculty of Medicine La Universidad del ZuliaMaracaibo 4002ZuliaVenezuela College of Engineering and Technology American University of Middle East KuwaitEgaila 54200Kuwait Department of Biochemistry and Molecular Biology Howard University College of MedicineWashingtonDC 20060United States Pathology and Cancer Center Department of Biochemistry and Molecular BiologyHoward University College of MedicineWashingtonDC 20060United States

BACKGROUND The coronavirus disease 2019(COVID-19)disproportionately affected African Americans(AA)and Hispanics(HSP).AIM To analyze the significant effectors of outcome in African American patient population and make special emphasis on gastrointestinal(GI)symptoms,laboratory values and comorbidities METHODS We retrospectively evaluated the medical records of 386 COVID-19 positive patients admitted at Howard University Hospital between March and May 2020.We assessed the symptoms,including the GI manifestations,comorbidities,and mortality,using logistic regression analysis.RESULTS Of these 386 COVID-19 positive patients,257(63.7%)were AAs,102(25.3%)HSP,and 26(6.45%)Whites.There were 257(63.7%)AA,102(25.3%)HSP,26(6.45%)Whites.The mean age was 55.6 years(SD=18.5).However,the mean age of HSP was the lowest(43.7 years vs 61.2 for Whites vs 60 for AAs).The mortality rate was highest among the AAs(20.6%)and lowest among HSP(6.9%).Patients with shortness of breath(SOB)(OR2=3.64,CI=1.73-7.65)and elevated AST(OR2=8.01,CI=3.79-16.9)elevated Procalcitonin(OR2=8.27,CI=3.95-17.3),AST(OR2=8.01,CI=3.79-16.9),ferritin(OR2=2.69,CI=1.24-5.82),and Lymphopenia(OR2=2.77,CI=1.41-5.45)had a high mortality rate.Cough and fever were common but unrelated to the outcome.Hypertension and diabetes mellitus were the most common comorbidities.Glucocorticoid treatment was associated with higher mortality(OR2=5.40,CI=2.72-10.7).Diarrhea was prevalent(18.8%),and GI symptoms did not affect the outcome.CONCLUSION African Americans in our study had the highest mortality as they consisted of an older population and comorbidities.Age is the most important factor along with SOB in determining the mortality rate.Overall,elevated liver enzymes,ferritin,procalcitonin and C-reactive protein were associated with poor prognosis.GI symptoms did not affect the outcome.Glucocorticoids should be used judiciously,considering the poor outcomes associated with it.Attention should also be paid to monitor liver function during COVID-19,especially in AA and HSP patient

关键词： COVID-19 Pandemic,Gastrointestinal manifestation Liver African Americans Hispanics

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