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The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries

Open Journal of Ecology 2024年第5期14卷 455-482页

作者： Joseph Mayindo Mayele jacob b. kolleh Joel Emmanuel Sab.ri Department of Agricultural and Resource Economics The University of Tokyo Tokyo Japan Department of Forestry and Wildlife College of Natural Resources and Environmental Studies University of Juba Juba South Sudan Department of Socio-Economic and Applied Statistics Central Agricultural Research Institute (CARI) Suakoko Liberia

This report provides an overall assessment of land fragmentation prob.ems in East Africa. Many parts of East Africa have b.come highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urb.nization, invaded b. non-local plants, or enclosed for individual use and b. sub.ividing farmlands into sub.equent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possib.e. Land fragmentation is one of the key reasons why the ab.lity of most resources in East Africa b.comes scarcer, and those remaining b.come “privatized” b. more powerful community memb.rs—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further b. affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation prob.ems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighb.ring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a sub.tantial increase in population density. The study review further explores the trend in the performance of agriculture b. average farm sizes within the intervals of five years b. highlighting their strong linkages and found that the average farm size has declined drastically, especiall

关键词： Land Fragmentation Land Consolidation Farm Productivity Industrialization Impacts Causes Average Farm Size Population East Africa

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The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries

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Open Journal of Ecology（生态学期刊） 2024年第5期 455页

作者： Joseph Mayindo Mayele jacob b.kolleh Joel Emmanuel Sab.ri

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Pleistocene glaciation advances the cryptic speciation of Stellera chamaejasme *** a major b.odiversity hotspot

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Journal of Integrative Plant b.ology 2024年第6期66卷 1192-1205页

作者： Santosh Kumar Rana Hum Kala Rana jacob b.andis Tianhui Kuang Juntong Chen Hengchang Wang Tao Deng Charles C.Davis Hang Sun CAS Key Lab.ratory for Plant Diversity and b.ogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Arkansas b.osciences Institute Arkansas State UniversityJonesboroArkansas 72401USA School of Integrative Plant Science Section of Plant Biology and the L.H.Bailey HortoriumCornell UniversityIthacaNew York 14853USA b.I Computational b.ology Center Boyce Thompson InstituteIthacaNew York 14853USA CAS Key Lab.ratory of Plant Germplasm Enhancement and Specialty Agriculture Chinese Academy of SciencesWuhan Botanical GardenWuhan 430074China Department of Organismic and Evolutionary b.ology HerbariaHarvard UniversityCambridgeMassachusetts 02138USA

The mountains of Southwest China comprise a significant large mountain range and b.odiversity hotspot imperiled b. glob.l climate *** high species diversity in this mountain system has long b.en attrib.ted to a complex set of factors,and recent large-scale macroevolutionary investigations have placed a b.oad timeline on plant diversification that stretches from 10 million years ago(Mya)to the *** our increasing understanding of the temporal mode of speciation,finer-scale populationlevel investigations are lacking to b.tter refine these temporal trends and illuminate the ab.otic and b.otic influences of cryptic *** is largely due to the dearth of organismal sampling among closely related species and populations,spanning the incredib.e size and topological heterogeneity of this *** study dives into these evolutionary dynamics of speciation using genomic and ecomorphological data of Stellera chamaejasme *** identified four previously unrecognized cryptic species having indistinct morphological traits and large metapopulation of evolving lineages,suggesting a more recent diversification(~2.67-0.90 Mya),largely influenced b. Pleistocene glaciation and b.otic *** factors likely influenced allopatric speciation and advocated cyclical warming–cooling episodes along elevational gradients during the *** study refines the evolutionary timeline to b. much younger than previously implicated and raises the concern that projected future warming may influence the alpine species diversity,necessitating increased conservation efforts.

关键词： cryptic speciation glacial-interglacial Hengduan Mountains north-south migration Stellera chamaejasme

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Respiratory Mechanics, Respiratory Muscle Strength, Control of Ventilation and Gas Exchange in Patients with Autoimmune Liver Disease

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Open Journal of Respiratory Diseases 2024年第2期14卷 25-38页

作者： Ahmet b.ydur jacob Korula Divisions of Pulmonary Critical Care and Sleep Medicine Los Angeles USA Keck School of Medicine University of Southern California Los Angeles California USA Liver Diseases Rancho Los Amigos National Rehabilitation Center Downey California USA

Ob.ectives: To assess respiratory elastance and resistive properties in patients with autoimmune liver disorders using the passive relaxation expiration technique and compare findings to a group of patients with non-autoimmune liver disease and control sub.ects. These findings were then related to control of ventilation and gas exchange. A secondary ob.ective was to assess respiratory muscle strength and gas exchange and their relation to respiratory mechanics. Methods: Measurements included respiratory elastance and resistance using the passive relaxation method. Pulmonary function, gas exchange and control of ventilation were assessed using standard methods. Results: a) Compared to control sub.ects, Ers in patients with liver disease was on average 50% greater than in controls;b. mean respiratory resistance, expressed as the respiratory constants, Kb.1b. and Kb.2b. in the Rohrer relationship, Pao/V’ = Kb.1b. + Kb.2b.V’, was not different from control resistance;c) mean maximal inspiratory and maximal expiratory pressures averaged 36% and 55% of their respective control values;d) inspiratory occlusion pressure in 0.1 sec (Pb.0.1b.) was increased and negatively associated with FVC;and e) increases in Pb.0.1b., mean inspiratory flow (Vt/Ti) and presence of respiratory alkalosis confirmed the increase in ventilatory drive. Despite inspiratory muscle weakness in patients, Pb.0.1b./Pimax averaged 5-fold higher than in control sub.ects. Conclusions: Despite inspiratory muscle weakness and a V’b.Eb. similar to that in normal sub.ects, central drive is increased in patients with chronic liver disease. The increase in ventilatory drive is related to smaller lung volumes and weakly associated with increase in respiratory elastance. Findings confirm that Pb.0.1b. is a reliab.e measure of central drive and is an approach that can b. used in the evaluation of control of ventilation in patients with chronic liver dis

关键词： Autoimmune Liver Disease Control of Ventilation Occlusion Pressure Passive Relaxation Method Primary b.liary Cirrhosis Respiratory Elastance Respiratory Resistance

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Aging impairs the osteocytic regulation of collagen integrity and b.ne quality

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b.ne Research 2024年第1期12卷 78-94页

作者： Charles A.Schurman Serra Kaya Neha Dole Nadja M.Maldonado Luna Natalia Castillo Ryan Potter jacob P.Rose Joanna b.ns Christina D.King Jordan b.b.rton b.rgit Schilling Simon Melov Simon Tang Eric Schaib.e Tamara Alliston Department of Orthopaedic Surgery University of CaliforniaSan FranciscoCA 94143USA UC b.rkeley/UCSF Graduate Program in b.oengineering San FranciscoCA 94143USA b.ck Institute for Research on Aging NovatoCA 94945USA Washington University in St Louis Department of OrthopedicsSt.LouisMO 63130USA Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA

Poor b.ne quality is a major factor in skeletal fragility in elderly *** molecular mechanisms that estab.ish and maintain b.ne quality,independent of b.ne mass,are unknown b.t are thought to b. primarily determined b. *** hypothesize that the age-related decline in b.ne quality results from the suppression of osteocyte perilacunar/canalicular remodeling(PLR),which maintains b.ne material *** examined b.nes from young and aged mice with osteocyte-intrinsic repression of TGFβsignaling(TβRII^(ocy−/−))that suppresses *** control aged b.ne displayed decreased TGFβsignaling and PLR,b.t aging did not worsen the existing PLR suppression in male TβRII^(ocy−/−)*** relationship impacted the b.havior of collagen material at the nanoscale and tissue scale in macromechanical *** effects of age on b.ne mass,density,and mineral material b.havior were independent of osteocytic TGFβ.We determined that the decline in b.ne quality with age arises from the loss of osteocyte function and the loss of TGFβ-dependent maintenance of collagen integrity.

关键词： maintain primarily integrity

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Shifts in reproductive strategies in the evolutionary trajectory of plant lineages

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Science China Life Sciences 2024年

作者： Xin-Jian Zhang Xian-Han Huang jacob b.Landis Quan-Sheng Fu Jun-Tong Chen Peng-Rui Luo Li-Juan Li Heng-Yi Lu Hang Sun Tao Deng State Key Lab.ratory of Plant Diversity and Specialty Crops Kunming Institute of Botany Chinese Academy of Sciences Yunnan International Joint Lab.ratory for b.odiversity of Central Asia Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences School of Integrative Plant Science Section of Plant Biology and the L.H.Bailey Hortorium Cornell University b.I Computational b.ology Center Boyce Thompson Institute CAS Key Lab.ratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical Garden Chinese Academy of Sciences

Understanding the maintenance and shift in reproductive strategies is a fundamental question in evolutionary research. Although many efforts have b.en made to compare different reproductive strategies, the association b.tween reproductive strategies and lineage divergence is largely unknown. To explore the impact of different reproductive strategies on lineage divergence, we investigated the evolution of clonality in Saxifraga sect. Irregulares+Heterisia. b. integrating several lines of evidence, we found that the loss of clonality in Irregulares+Heterisia was associated with a progressive increase in diversification rate and intraspecific morphological diversity b.t with a reduction in species distrib.tion range. Our findings provide insights into the ecological and evolutionary effects of different reproductive strategies,suggesting the necessity of integrating clonality into ecological and evolutional research.

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Resonant Raman scattering in GaN single crystals and GaN-b.sed heterostructures: feasib.lity for laser cooling

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Chinese Optics Letters 2013年第1期11卷 63-71页

作者： Yujie J. Ding jacob b. Khurgin Department of Electrical and Computer Engineering Lehigh University Department of Electrical and Computer Engineering The Johns Hopkins University

The recent progress on Raman scattering in GaN single crystals and GaN/A1N heterostructures is re- viewed. Anti-Stokes Raman scattering is used to determine electron-phonon scattering time and decay time constant for longitudinal-opticat phonons. In a typical high electron mob.lity transistor b.sed on GaN/A1N heterostructures, strong resonances are reached for the first-order and second-order Raman scattering processes. Therefore, b.th Stokes and anti-Stokes Raman intensities are dramatically enhanced. The feasib.lity for laser cooling of a nitride structure is studied. A further optimization will enab.e us to reach the threshold for laser cooling. Raman scattering have potential applications in up-conversion lasers and laser cooling of nitride ultrafast electronic and optoelectronic devices.

关键词： GaN Ra Resonant Raman scattering in GaN single crystals and GaN-b.sed heterostructures feasib.lity for laser cooling

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Effects of rodent ab.ndance and richness on cache pilfering

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Integrative Zoology 2018年第3期13卷 331-338页

作者： jacob W.DITTEL Stephen b.VANDER WALL Department of Fisheries and Wildlife Oregon State UniversityCorvallisOregonUSA Department of b.ology and the Program in Ecology Evolutionand Conservation BiologyUniversity of NevadaRenoNevadaUSA

Scatterhoarding is a common b.havioral strategy to conserve food during periods of scarcity,b.t this type of food storage is vulnerab.e to theft or pilferage.A variety of environmental factors and cache characteristics influence the rate of *** we investigate 2 environmental factors,which heretofore have not received much attention:the ab.ndance and species richness of scatterhoarding animals in the vicinity of scatterhoarded *** measured the rate of cache pilferage at 7 sites that differed in the numb.r and species composition of granivorous rodents in western Nevada using local native seeds and sunflower *** found that there was no difference b.tween the pilferage rate of native seeds and sunflower seeds,b.t that sites with different rodent ab.ndances had different pilferage *** rates were proportional to the ab.ndance of scatterhoarding *** rodents removed seeds at the rate of 1.3%/day/rodent *** richness of scatterhoarding rodents was not correlated with rates of *** results suggest that density-dependent competition for scatterhoarded seeds is a strong determinant of pilferage rates.

关键词： cache pilfering competition food hoarding heteromyids rodent ab.ndance scatter hoarding sciurids

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Factors controlling nutrient availab.lity to the developing fetus in ruminants

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Journal of Animal Science and b.otechnology 2015年第2期6卷 205-214页

作者： Kathrin A Dunlap jacob D b.own Ashley b.Keith M Carey Satterfield Department of Animal Science Texas A&M University2471 TAMU College Station

Inadequate delivery of nutrients results in intrauterine growth restriction （IUGR）, which is a leading cause of neonatal morb.dity and mortality in livestock. In ruminants, inadequate nutrition during pregnancy is often prevalent due to frequent utilization of exensive forage b.sed grazing systems, making them highly susceptib.e to changes in nutrient quality and availab.lity. Delivery of nutrients to the fetus is dependent on a numb.r of critical factors including placental growth and development, utero-placental b.ood flow, nutrient availab.lity, and placenta metab.lism and transport capacity. Previous findings from our lab.ratory and others, highlight essential roles for amino acids and their metab.lites in supporting normal fetal growth and development, as well as the critical role for amino acid transporters in nutrient delivery to the fetus. The focus of this review will b. on the role of materna nutrition on placental form and function as a regulator of fetal development in ruminants.

关键词： Intrauterine growth restriction Nutrient transport Placenta Ruminant

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The Mathematical Theory of Multifocal Lenses(Dedicated to Professor Haim b.ezis on the occasion of his 70th b.rthday)

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Chinese Annals of Mathematics,Series b 2017年第2期38卷 647-660页

作者： jacob RUb.NSTEIN department of mathematics TechnionHaifa 32000Israel

This paper presents the fundamental optical concepts of designing multifocal ophthalmic lenses and the mathematical methods associated with them. In particular, it is shown that the design methodology is heavily b.sed on differential geometric ideas such as Willmore surfaces. A key role is played b. Hamilton's eikonal functions. It is shown that these functions capture all the information on the local b.ur and distortion created b. the lenses. Along the way, formulas for computing the eikonal functions are derived. Finally,the author lists a few intriguing mathematical prob.ems and novel concepts in optics as future projects.

关键词： Optical design, Differential geometry, Eikonal functions,Multifocal lenses

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