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Impact of deforestation on habitat connectivity thresholds for large carnivores in tropical forests

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Ecological processes 2017年第1期6卷 214-224页

作者： Miriam A.Zemanova Humberto L.perotto-Baldivieso Emily L.Dickins Andrew B.Gill John p.leonard David B.Wester School of Energy Environment and AgrifoodCranfield UniversityCranfield MK430ALUK Institute of Ecology and Evolution University of BernBaltzerstrasse 63012 BernSwitzerland Caesar Kleberg Wildlife Research Institute Texas A&M University-Kingsville700 University Blvd.MSC 218KingsvilleTX 78363USA Museo de Historia Natural Noel Kempff Mercado Universidad Autónoma Gabriel Rene MorenoAvenida Irala 565Santa Cruz de la SierraBolivia Hensmans Farm Nearton EndSwanbourne MK170SLUK Cape Eleuthera Institute EleutheraBahamas

Introduction:Deforestation significantly impacts large carnivores that depend on large tracts of interconnected forest habitat and that are sensitive to human *** the relationship between habitat use and spatial distribution of such species across human modified landscapes is critical when planning effective conservation *** study assessed the presence of potential landscape connectivity thresholds resulting from habitat fragmentation associated with different deforestation patterns using a scale-based approach that links species-specific home ranges with the extent of anthropogenic *** objectives were(1)to quantify the spatial and temporal distribution of natural vegetation for five common deforestation patterns and(2)to evaluate the connectivity associated with these patterns and the existence of potential thresholds affecting jaguar *** Bolivian lowlands,located within jaguar conservation units,were analysed with landscape metrics to capture the spatial and temporal changes within deforested areas and to determine potential impact on jaguar connectivity and connectivity thresholds for ***:Over the period of 1976–2005,the amount of natural vegetation has decreased by more than 40%in all locations with the biggest changes occurring between 1991 and *** spatial structure around jaguar locations showed that jaguars used areas with mean proportion of natural areas=83.14%(SE=3.72%),mean patch density=1.16 patches/100 ha(SE=0.28 patches/100 ha),mean patch area=616.95 ha(SE=172.89 ha)and mean edge density=705.27 m/ha(SE=182.19 m/ha).We observed strong fragmentation processes in all study locations,which has resulted in the connectivity of jaguar habitat decreasing toproportion of natural vegetation was less than 58.4%(SE=1.3).Conclusions:Assessing fragmentation and connectivity for carnivores within the extent of human-modified la

关键词： Bolivian lowlands Habitat fragmentation Landscape metrics panthera onca Threshold

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DSp应用指南

电子设计技术 1995年第11期 28+30-32页

作者： Markus Levy James p leonard

欢迎阅读1995年DSp指南。本文的目的是向你提供有关通用DSp 芯片的简要而有用的、并且是最新的信息,以便用于你的下一个项目的设计。虽然你的研究可能会超过本指南的范围之外,但它的应用却可用作一个起点:你将从指南的技术分析资料中得... 详细信息

欢迎阅读1995年DSp指南。本文的目的是向你提供有关通用DSp 芯片的简要而有用的、并且是最新的信息,以便用于你的下一个项目的设计。虽然你的研究可能会超过本指南的范围之外,但它的应用却可用作一个起点:你将从指南的技术分析资料中得到益处,并对DSp芯片的件能和标准(技术规范)有一个全面的了解。

关键词： DSp 芯片开发工具

Understanding the catalysis of chromium trioxide added magnesium hydride for hydrogen storage and Li ion battery applications

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Journal of Magnesium and Alloys 2024年第3期12卷 1117-1130页

作者： D.pukazhselvan IhsanÇaha Catarina de Lemos Sergey M.Mikhalev Francis leonard Deepak Duncan paul Fagg Department of Mechanical Engineering TEMA-Centre for Mechanical Technology and AutomationUniversity of AveiroAveiro 3810-193Portugal LASI-Intelligent Systems Associate Laboratory Guimarães 4800-058Portugal Nanostructured Materials Group International Iberian Nanotechnology Laboratory(INL)Avenida Mestre Jose VeigaBraga 4715-330Portugal

This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.CrO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with MgH_(2).In depth characterization study by X-ray diffraction(XRD)technique provides convincing evidence that the CrO_(3) additive interacts with MgH_(2) and produces Cr/MgO *** free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/CrO_(3) to MgO/Cr,which is well supported by the identification of Cr(0)in the powder by X ray photoelectron spectroscopy(XpS)*** high resolution transmission electron microscopy(HRTEM)and energy dispersive spectroscopy(EDS)we found evidence for the presence of 5 nm size Cr nanocrystals on the surface of MgO rock salt *** is also convincing ground to consider that MgO rock salt accommodates Cr in the *** observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of MgH_(2),both for the improved storage of hydrogen and lithium.

关键词： Hydrogen storage Rechargeable batteries Binary hydrides Metal oxides Catalytic mechanism.

Jatonik polyherbal mixture induced rat liver MMpT pore opening in normal Wistar rat:In vitro and in vivo studies

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Chinese Herbal Medicines 2024年第1期16卷 113-120页

作者： Olabinri p.Folashade Ibrahim Damilare Boyenle Tolulope A.Oyedeji Fiyinfoluwa Demilade Ojeniyi Adisa Ayobami Damilare leonard O.Ehigie Adeola Folasade Ehigie Membrane Biochemistry and Biophysics Research Laboratory Department of BiochemistryLadoke Akintola University of TechnologyOgbomoso 210214Nigeria Computational Biology/Drug Discovery Laboratory Department of BiochemistryLadoke Akintola University of TechnologyOgbomoso 210214Nigeria College of Health Sciences Crescent University AbeokutaAbeokuta 111105Nigeria Department of Biochemistry University of LagosLagos 101017Nigeria

Objective:To assess acute toxicity,the in vitro and in vivo effects of methanol and ethyl acetate extracts(JME and JEE)of Jatonik polyherbal mixture on some mitochondria-related parameters and their effect on the activity of some liver ***:Acute toxicity of JME and JEE was determined using Lorke’s *** vitro and in vivo opening of the mitochondrial membrane permeability transition pore(MMpT pore)was spectrophotometrically *** of malondialdehyde(MDA)as an index of lipid peroxidation and the activity of mitochondrial ATpase was evaluated in vitro and in vivo and the effect of JME and JEE on the activity of liver enzymes such as alkaline phosphatase(ALp),aspartate and alanine aminotransferase(AST and ALT)and gamma-glutamyl transferase(GGT)was also ***:JME had an LD_(50) of 3808 mg/kg b.w whereas JEE had an LD_(50) greater than 5000 mg/kg *** *** the rats have been fed with both extracts,a photomicrograph of a piece of liver tissue showed no apparent symptoms of *** the in vitro and in vivo studies,both extracts prompted intact mitochondria to open their MMpT *** compared to the control,lipid peroxide product release and ATpase activity were significantly increased(pppolyherbal mixture had low toxicity,profound MMpTpore induction,and enhanced ATpase activity,but an increased MDA ***:Jatonik extracts may be a promising target for drug development in diseases where there is dysregulation of apoptosis,however,further studies are needed to better clarify the molecular mechanism involved in these phenomena.

关键词： acute toxicity Ageratum conyzoides Linn. apoptosis Hunteria umbellate(K.Schum.)Hallier f. Lepidium meyenii Walp. mitochondrial ATpase mitochondrial lipid peroxidation mitochondrial membrane permeability transition pore polyherbal mixture Xylopia aethiopica(Dunal)A.Rich

与外电路耦合的电机三维有限元模型的对称化处理

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国外大电机 2001年第2期 34-38页

作者： p.J.leonard 李金香等

本文讨论了用有限元方法处理三维电机电磁场问题。回顾了与外电路耦合的方法。通过系统矩阵的比例系数考虑对称。本文也讨论了周期性边界条件的处理。

关键词：开关磁阻电动机三维有限元模型对称化处理电路耦合

重新设计半主动末制导寻的导弹俯仰稳定控制系统用的计算机辅助法

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系统工程与电子技术 1981年第12期 7-21页

作者： L.S.Shieh ,M.Datta-Barua ,R.E.Yates ,J.p.leonard ,宗有德

过去末制导寻的导弹的不稳定俯仰控制系统是用高阶稳定滤波器来稳定的。这种滤波器采用有源部件。本文提出一种新的主要数据匹配法来重新设计高阶稳定滤波器,以求得一种降阶滤波器。结果降低了器件的成本,提高了可靠性。本文还用一种代... 详细信息

过去末制导寻的导弹的不稳定俯仰控制系统是用高阶稳定滤波器来稳定的。这种滤波器采用有源部件。本文提出一种新的主要数据匹配法来重新设计高阶稳定滤波器,以求得一种降阶滤波器。结果降低了器件的成本,提高了可靠性。本文还用一种代数法来改进重新设计的俯仰控制系统性能。此外,所提出的主要数据匹配法还能用来确定高阶系统的降阶模型。与大多数现有模型简化法不同的是,降阶模型具有原系统精确指定的频率域指标。计算机辅助设计法还可用于设计一般类型的控制系统。

关键词：稳定滤波器重新设计匹配法摄动法传递函数转移函数方程降阶模型末端制导末制导寻的导弹

Epidemiological, Clinical, Therapeutic and Evolutive profile of primary Open-Angle Glaucoma in a Cameroonian population

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Open Journal of Ophthalmology 2024年第2期14卷 93-102页

作者： Christelle Domngang Fabiola Makamwe Tagne leonard Tedong Chantal Ngoune Nanfack Caroline Mvilongo Giles Kagmeni Higher Institute of Health Sciences Université des Montagnes Bangangté Cameroon Faculty of Medicine and Biomedical Sciences University of Yaounde 1 Yaounde Cameroon

Background: Sub-Saharan Africa has the highest prevalence of primary open-angle glaucoma (pOAG), at 4.2%. The efficacy of medical treatment has been demonstrated and remains one of the treatments of choice for pOAG. However, in sub-Saharan Africa, its effectiveness has many challenges, due to multiple factors, including cost and access to care. Thus, the present study aimed to determine the epidemiological, clinical, therapeutic and evolutive profile of primary open-angle glaucoma patients. Methodology: A descriptive cross-sectional study was carried out in two hospitals in western Cameroon. Epidemiological, clinical, therapeutic, and evolutionary data on intraocular pressure at one year after medical treatment were analyzed. SpSS version 23 software was used for statistical analysis, with a significant p-value set at 5%. Results: A total of 201 patients with pOAG were included in the study. The population comprised 100 men and 101 women, with a mean age of 54 ± 12 years. At diagnosis, the mean intraocular pressure was 23.9 ± 8.70 mmHg for the right eye and 25.5 ± 9.57 mmHg for the left eye. The mean cup/disc ratio was 0.64 ± 0.2 [0.2-1] and 0.67 ± 0.19 [02-1] in the right and left eyes, respectively. Monotherapy was the most prescribed treatment [59.2%]. After one year of treatment, intraocular pressure was reduced by 15.5% with beta-blockers, 23.66% with prostaglandins, 19.11% with carbonic anhydrase inhibitors, 35, 92% with beta-blockers and carbonic anhydrase inhibitors, 25.92% with beta-blockers and prostaglandins, 48.03% with carbonic anhydrase inhibitors and prostaglandin agonists, and 38.77% with triple therapy. Taking glaucoma severity into account, a significant reduction in intraocular pressure at one year was observed in all participants [p 0.05]. However, the target pressure was obtained in 47%, 20% and 14% of eyes suffering of mild, moderate, and severe grade of pOAG respectively. Conclusion: In the present study, there was a significant reduction in i

关键词： primary Open-Angle Glaucoma Medical Treatment Intraocular pressure Target Intraocular pressure

Association between baseline levels of muscular strength and risk of stroke in later life:The Cooper Center Longitudinal Study

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Journal of Sport and Health Science 2024年第5期13卷 642-649页

作者： Stephen W.Farrell David leonard Qing Li Carolyn E.Barlow Kerem Shuval Jarett D.Berry Andjelka pavlovic Laura F.DeFina Research Division The Cooper InstituteDallasTX 75230USA Department of Internal Medicine University of Texas at Tyler School of MedicineTylerTX 75799USA

Background:Muscular strength is an important component of physical *** evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged≥65 years during ***:We included 7627 healthy adults(mean age=43.9 years,86.0%male)underwent a baseline physical examination between 1980 and *** strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age-and sex-specific tertiles for each *** fitness(CRF)was assessed via a maximal treadmill exercise *** enrolled in fee-for-service Medicare from 1999 to 2019 were included in the *** between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards *** a secondary analysis,we examined stroke risk by categories of CRF where Quintile 1=low,Quintiles 2-3=moderate,and Quintiles 4-5=high CRF based on age and ***:After 70,072 person-years of Medicare follow-up,there were 1211 earliest indications of incident *** multivariable analyses,the hazard ratio(95%confidence interval(95%CI))for stroke across bench press categories were 1.0(referent),0.96(0.83-1.11),and 0.89(0.77-1.04),respectively(p trend=0.14).The trend across categories of leg press was also non-significant(p trend=0.79).Adjusted hazard ratio(95%CI)for stroke across ordered CRF categories were 1.0(referent),0.90(0.71-1.13),and 0.72(0.57-0.92)(p trendpublic health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults,performing such activities may not be helpful in preventing ***,meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

关键词： Cardiorespiratory fitness Medicare Muscular strength Stroke

partial protection by Lipoic Acid Against Carboplantin-induced Ototoxicity in Rats

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Biomedical and Environmental Sciences 2005年第3期18卷 198-206页

作者： KAZIM HUSAIN CRAIG WHITWORTH SATU M. SOMANI leonard p. RYBAK Departments of Surgery Southern Illinois University School of Medicine Springfield IL 62794 USADepartments of Surgery Southern Illinois University School of Medicine Springfield IL 62794 USADepartments of Pharmacology Southern Illinois University School of Medicine Springfield IL 62794 USADepartments of Surgery Southern Illinois University School of Medicine Springfield IL 62794 USA

Objective To investigate the alterations in auditory brainstem evoked responses (ABRs) and the changes of carboplatin-induced ototoxicity in the cochlear oxidant/antioxidant systems and otoprotection by an antioxidant lipoate. Methods Male wistar rats were divided into four groups and treated as follows: 1) vehicle (saline) control, 2) carboplatin (256 mg/kg, i.p.), 3) lipoate (100 mg/kg, i.p.), 4) lipoate + carboplatin. post-treatment ABRs were performed after four days and rats were sacrificed with their cochleae harvested and analyzed. Results Carboplatin significantly elevated ABR threshold above the pretreatment thresholds. Lipoate+carboplatin treated rats showed decreased elevation of hearing threshold. Carboplatin significantly depleted cochlear reduced to oxizized glutathione (GSH/GSSG) ratio, whereas lipoate+carboplatin treatment increased GSH/GSSG ratio. Carboplatin significantly decreased cochlear copper zinc-superoxide dismutase (CuZn-SOD), catalase (CAT), glutathione peroxidase (GSH-px), glutathione reductase (GR) and glutathione-S-transferase (GST) activities and enzyme protein expressions and a significant increase in Mn-SOD activity, protein expression and malondialdehyde (MDA) level. Cochlear antioxidant enzyme activities, enzyme protein expressions and MDA level were partially restored in lipoate+carboplatin treated rats, compared to carboplatin alone. Conclusion Carboplatin-induced ototoxicity is related to impairment of cochlear antioxidant system and otoprotection conferred by lipoate is associated with partial sparing of the cochlear antioxidant defense system.

关键词： Carboplatin Alpha-lipoic acid Ototoxicity Antioxidants Rats