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Removing subordinate species in a biodiversity experiment to mimic observational field studies

Grassland Research 2022年第1期1卷 53-62页

作者： Bernhard Schmid Martin Schmitz Michael Rzanny Michael Scherer-Lorenzen peter n.mwangi Wolfgang W.Weisser Andrew Hector Roland Schmid Dan F.B.Flynn Remote Sensing Laboratories Department of GeographyUniversity of ZurichZurichSwitzerland Department of Planning and Energy Municipality of ThalwilThalwilSwitzerland Department Biogeochemical Integration Max Planck Institute for BiogeochemistryJenaGermany Geobotany Faculty of BiologyUniversity of FreiburgFreiburgGermany Department of Botany Jomo Kenyatta University of Agriculture and TechnologyNairobiKenya Department of Life Science Systems School of Life SciencesTechnical University of MunichFreisingGermany Department of Plant Sciences University of OxfordOxfordUK Mirai Solutions GmbH ZurichSwitzerland Energy Analysis&Sustainability John A.Volpe National Transportation Systems CenterCambridgeMassachusettsUSA

Background:Positive effects of plant species richness on community biomass in biodiversity experiments are often stronger than those from observational field *** may be because experiments are initiated with randomly assembled species compositions whereas field communities have experienced ***:We compared aboveground biomass production of randomly assembled communities of 2–16 species(controls)with experimentally filtered communities from which subordinate species were removed,resulting in removal communities of 1–8 ***:Removal communities had(1)12.6%higher biomass than control communities from which they were derived,that is,with double species richness and(2)32.0%higher biomass than control communities of equal *** differences were maintained along the richness *** increased productivity of removal communities was paralleled by increased species evenness and ***:Result(1)indicates that subordinate species can reduce community biomass production,suggesting a possible explanation for why the most diverse field communities sometimes do not have the highest ***(2)suggests that if a community of S species has been derived by filtering from a pool of 2S randomly chosen species it is more productive than a community derived from a pool of S randomly chosen species without filtering.

关键词： environmental filtering Jena Experiment plant community species pool species richness

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Modeling impacts of climate change on the potential distribution of six endemic baobab species in Madagascar

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Plant Diversity 2021年第2期43卷 117-124页

作者： Jun-nan Wan ndungu J.Mbari Sheng-Wei Wang Bing Liu Brian n.mwangi Jean R.E.Rasoarahona Hai-Ping Xin Ya-Dong Zhou Qing-Feng Wang Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical GardenChinese Academy of SciencesWuhanHubei430074PR China State Key Laboratory of Systematic and Evolutionary Botany Institute of BotanyChinese Academy of SciencesBeijing100093PR China University of Chinese Academy of Sciences Beijing100049PR China Sino-Africa Joint Research Center Chinese Academy of SciencesWuhanHubei430074PR China High School of Agricultural Sciences University of AntananarivoP.O.Box 175Madagascar

Madagascar,a globally renowned biodiversity hotspot characterized by high rates of endemism,is one of the few remaining refugia for many plants and animal ***,global climate change has greatly affected the natural ecosystem and endemic species living in Madagascar,and will likely continue to influence species distribution in the *** is home to six endemic baobab(Adansonia spp.,Bombacoideae[Malvaceae])species(Adansonia grandidieri,***,***,***,***,***),which are remarkable and endangered *** study aimed to model the current distribution of suitable habitat for each baobab species endemic to Madagascar and determine the effect that climate change will have on suitable baobab habitat by the years 2050 and *** distribution was modeled using MaxEnt based on locality information of 245 occurrence sites of six species from both online database and our own field work.A total of seven climatic variables were used for the modeling *** present distribution of all six Madagascar's baobabs was largely influenced by temperature-related *** both expansion and contraction of suitable habitat are predicted for all species,loss of original suitable habitat is predicted to be *** the most widespread Madagascar baobab,***,more than 40%of its original habitat is predicted to be lost because of climate *** on these findings,we recommend that areas predicted to contract in response to climate change should be designated key protection regions for baobab conservation.

关键词： Madagascar Adansonia Climate change MaxEnt Potential distribution

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Design methods for antimicrobial peptides with improved performance

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Zoological Research 2023年第6期44卷 1095-1114页

作者： James mwangi peter Muiruri Kamau Rebecca Caroline Thuku Ren Lai Key Laboratory of Bioactive Peptides of Yunnan Province Engineering Laboratory of Peptides of Chinese Academy of SciencesKIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common DiseasesNational Resource Centre for Non-Human PrimatesKunming Primate Research CentreNational Research Facility for Phenotypic&Genetic Analysis of Model Animals(Primate Facility)Sino-African Joint Research CentreNew Cornerstone Science InstituteKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650107China Centre for Evolution and Conservation Biology Southern Marine Science and Engineering Guangdong LaboratoryGuangzhouGuangdong 511458China Kunming College of Life Science University of Chinese Academy of SciencesKunmingYunnan 650204China

The recalcitrance of pathogens to traditional antibiotics has made treating and eradicating bacterial infections more *** this regard,developing new antimicrobial agents to combat antibiotic-resistant strains has become a top *** peptides(AMPs),a ubiquitous class of naturally occurring compounds with broadspectrum antipathogenic activity,hold significant promise as an effective solution to the current antimicrobial resistance(AMR)*** AMPs have been identified and evaluated for their therapeutic application,with many already in the drug development *** distinct properties,such as high target specificity,potency,and ability to bypass microbial resistance mechanisms,make AMPs a promising alternative to traditional ***,several challenges,such as high toxicity,lability to proteolytic degradation,low stability,poor pharmacokinetics,and high production costs,continue to hamper their clinical ***,recent research has focused on optimizing the properties of AMPs to improve their *** understanding the physicochemical properties of AMPs that correspond to their activity,such as amphipathicity,hydrophobicity,structural conformation,amino acid distribution,and composition,researchers can design AMPs with desired and improved *** this review,we highlight some of the key strategies used to optimize the performance of AMPs,including rational design and de novo *** also discuss the growing role of predictive computational tools,utilizing artificial intelligence and machine learning,in the design and synthesis of highly efficacious lead drug candidates.

关键词： Antimicrobial resistance Antimicrobial peptides Design methods Peptidomimetics Artificial intelligence

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Structure of the 40S ribosomal subunit of Plasmodium falciparum by homology and de novo modeling

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Acta Pharmaceutica Sinica B 2017年第1期7卷 97-105页

作者： Harrison ndung'u mwangi peter Wagacha peterson Mathenge Fredrick Sijenyi Francis Mulaa Center for Biotechnology and Bioinformatics Chiromo CampusUniversity of Nairobi.HEP Bioinformatics Consultants Ltd. Department of Computing Informatics University of Nairobi DnA Software Inc. Department of Biochemistry Riverside DriveChiromo CampusUniversity of Nairobi

Generation of three dimensional structures of macromolecules using in silico structural modeling technologies such as homology and de novo modeling has improved dramatically and increased the speed by which tertiary structures of organisms can be generated. This is especially the case if a homologous crystal structure is already available. High-resolution structures can be rapidly created using only their sequence information as input, a process that has the potential to increase the speed of scientific discovery. In this study, homology modeling and structure prediction tools such as RnA123 and SWISS–MODEL were used to generate the 40 S ribosomal subunit from Plasmodium falciparum. This structure was modeled using the published crystal structure from Tetrahymena thermophila, a homologous eukaryote. In the absence of the Plasmodium falciparum 40 S ribosomal crystal structure, the model accurately depicts a global topology, secondary and tertiary connections, and gives an overall root mean square deviation(RMSD) value of 3.9 ? relative to the template's crystal structure. Deviations are somewhat larger in areas with no homology between the templates. These results demonstrate that this approach has the power to identify motifs of interest in RnA and identify potential drug targets for macromolecules whose crystal structures are unknown. The results also show the utility of RnA homology modeling software for structure determination and lay the groundwork for applying thisapproach to larger and more complex eukaryotic ribosomes and other RnA-protein complexes. Structures generated from this study can be used in in silico screening experiments and lead to the determination of structures for targets/hit complexes.

关键词： Ribosome 40S subunit RnA structure Plasmodium falciparum 3D modeling De novo Homology

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Variation of morphological and leaf stoichiometric traits of two endemic species along the elevation gradient of Mount Kenya, East Africa

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Journal of Plant Ecology 2020年第6期13卷 785-792页

作者： Antony n.Waigwa Brian njoroge mwangi Gituru R.Wahiti Fred Omengo Yadong Zhou Qingfeng Wang Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China Sino-Africa Joint Research Center(SAJOREC) Jomo Kenyatta University of Agriculture and TechnologyJujaNairobi 00200Kenya Department of Biodiversity Research Kenya Wildlife ServiceNairobi 00100Kenya Center of Conservation Biology Core Botanical GardensChinese Academy of SciencesWuhan 430074China Sino-Africa Joint Research Center(SAJOREC) Chinese Academy of SciencesWuhan 430074China

Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical *** In this study,we assessed the variation of the morphological traits,including plant height,leaf area,leaf thickness,leaf dry weight,specific leaf area and the leaf stoichiometry traits nitrogen,carbon and phosphorous of the two endemic species *** and *** further explored the relations of these morphological traits to soil organic carbon,soil total nitrogen,soil phosphorous,annual mean temperature,annual mean precipitation,annual total solar radiation,water vapor pressure and the topographic variables aspect,slope and hill shade along the elevation *** 10 m×10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 *** used 1 km×1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation *** performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory *** conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic,soil and topographic variables along the elevation *** Findings Dendrosenecio keniensis had wool-like pubescent leaves while *** had mucilage packed succulent and waxy cuticle leaves to avoid *** species exhibited reduced metabolic rates as shown by the low leaf phosphorous *** results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate,soil and topographic variables that change along elevation on Mount *** observed variations in the morphological and leaf stoichiometric traits of *** and ***,which grow side by side along the elevation gradient,were interpreted as adaptation to the harsh en

关键词： Africa elevation gradient functional traits adaptability climate change

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Medical therapy for spermatogenic failure

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Asian Journal of Andrology 2012年第1期14卷 57-60,176页

作者： Ranjith Ramasamy peter J Stahl peter n Schlegel Department of Urology Weill Cornell Medical College New York NY 10065 USA

Medical treatment of men with primary spermatogenic failure remains largely ineffective in contrast to those with secondary testicular failure. Treatment has been attempted with a multitude of agents ranging from hormones to nutritional supplements （antioxidants）. While some studies have demonstrated benefit to some treatments, no treatments have consistently demonstrated efficacy nor has it been possible to reliably identify patients likely to benefit. Idiopathic spermatogenic failure likely results from multiple discrete defects in sperm production that are as yet unidentified. A better understanding of these defects will yield more effective treatment options and appropriate triage of patients to specific therapeutic regimens. This review focuses on the rationale and current evidence for hormonal and antioxidant therapy in medical treatment of male infertility, spermatogenic failure in particular. Although empiric medical therapy for spermatogenic failure has been largely replaced by assisted reproductive techniques, both treatment modalities could play a role, oerhaos as combination therapy.

关键词： antioxidant hormones male infertility sperm spermatogenesis spermatogenic failure testicular failure

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Microdissection testicular sperm extraction： an update

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Asian Journal of Andrology 2013年第1期15卷 35-39页

作者： Ali A Dabaja peter n Schlegel Department of Urology Male Reproductive Medicine Weill Cornell Medical College New York NY 10065 USA

Patients with non-obstructive azoospermia （nOA） were once considered to be infertile with few treatment options due to the absence of sperm in the ejaculate. In the last two decades, the advent of intracytoplasmic sperm injection （ICSI）, and the application of various testicular sperm retrieval techniques, including fine needle aspiration （FnA）, conventional testicular sperm extraction （TESE） and microdissection testicular sperm extraction （micro-TESE） have revolutionized treatment in this group of men. Because most men with nOA will have isolated regions of spermatogenesis within the testis, studies have illustrated that sperm can be retrieved in most men with nOA, including Klinefelter＇s syndrome （KS）, prior history of chemotherapy and cryptorchidism. Micro-TESE, when compared with conventional TESE has a higher sperm retrieval rate （SRR） with fewer postoperative complications and negative effects on testicular function. In this article, we will compare the efficacy of the different procedures of sperm extraction, discuss the medical treatment and the role of testosterone optimization in men with nOA and describe the micro-TESE surgical technique. Furthermore, we will update our overall experience to allow counseling on the prognosis of sperm retrieval for the specific subsets of nOA.

关键词： azoospermia genetics male infertility microsurgery non-obstructive azoospermia sperm retrieval testicular sperm extraction

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Deletion or underexpression of the Y-chromosome genes CDY2 and HSFY is associated with maturation arrest in American men with nonobstructive azoospermia

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Asian Journal of Andrology 2012年第5期14卷 676-682页

作者： peter J Stahl Anna n Mielnik Christopher E Barbieri peter n Schlegel Darius A Paduch Department of Urology Weill Cornell Medical CollegeNew York Presbyterian HospitaI-CornellNew YorkNY 10065USA

Maturation arrest （MA） refers to failure of germ cell development leading to clinical nonobstructive azoospermia. Although the azoospermic factor （AZF） region of the human Y chromosome is clearly implicated in some cases, thus far very little is known about which individual Y-chromosome genes are important for complete male germ cell development. We sought to identify single genes on the Y chromosome that may be implicated in the pathogenesis of nonobstructive azoospermia associated with MA in the American population. Genotype-phenotype analysis of 132 men with Y-chromosome microdeletions was performed. Protein-coding genes associated with MA were identified by visual analysis of a genotype-phenotype map. Genes associated with MA were selected as those genes within a segment of the Y chromosome that, when completely or partially deleted, were always associated with MA and absence of retrievable testicular sperm. Expression of each identified gene transcript was then measured with quantitative RT-PCR in testicular tissue from separate cohorts of patients with idiopathic MA and obstructive azoospermia. Ten candidate genes for association with MA were identified within an 8.4-Mb segment of the Y chromosome overlapping the AZFb region. CDY2and HSFYwere the only identified genes for which differences in expression were observed between the MA and obstructive azoospermia cohorts. Men with obstructive azoospermia had 12-fold higher relative expression of CDY2transcript （1.33__.0.40 vs. 0.11＋_0.04; P=O.O003） and 16-fold higher expression of HSFYtranscript （0.78__.0.32 vs. 0.05_0.02; P=O.O005） compared to men with MA. CDY2 and HSFYwere also underexpressed in patients with Sertoli cell only syndrome. These data indicate that CDY2and HSFYare located within a segment of the Y chromosome that is important for sperm maturation, and are underexpressed in testicular tissue derived from men with MA. These observations suggest that impairments in CDY2 or HSFYexpression could be impli

关键词： CDY1 protein CDY2 protein genetics histology HSFY human make infertility nonobstructive azoospermia spermato-genesis sperm maturation

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Better together? Treating traumatic brain injury with minocycline plus n-acetylcysteine

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neural Regeneration Research 2022年第12期17卷 2589-2592页

作者： Siobhán Lawless peter J.Bergold Graduate Program in neural and Behavioral Sciences State University of New York-Downstate Health Sciences UniversityBrooklynNYUSA Department of Physiology and Pharmacology State University of New York-Downstate Health Sciences UniversityBrooklynNYUSA

Traumatic brain injury has a complex pathophysiology that produces both rapid and delayed brain damage. Rapid damage initiates immediately after injury. Treatment of traumatic brain injury is typically delayed many hours, thus only delayed damage can be targeted with drugs. Delayed traumatic brain injury includes neuroinflammation, oxidative damage, apoptosis, and glutamate toxicity. Both the speed and complexity of traumatic brain injury pathophysiology present large obstacles to drug development. Repurposing of Food and Drug Administration-approved drugs may be a highly efficient approach to get therapeutics to the clinic. This review examines the preclinical outcomes of minocycline and n-acetylcysteine as individual drugs and compares them to the minocycline plus n-acetylcysteine combination. Both minocycline and n-acetylcysteine are Food and Drug Administration-approved drugs with pleiotropic therapeutic effects. As individual drugs, minocycline and n-acetylcysteine are well tolerated, with known pharmacokinetics, and enter the brain through an intact blood-brain barrier. At concentrations greater than needed for antimicrobial action, minocycline is a potent anti-inflammatory minocycline, also acts as an antioxidant and inhibits multiple enzymes that promote brain injury including metalloproteases, caspases, and polyADP-ribose-polymerase-1. n-acetylcysteine alone is also an antioxidant. It increases brain glutathione, prevents lipid oxidation, and protects mitochondria. n-acetylcysteine also acts as an anti-inflammatory as well as increases extracellular glutamate by activating the X;cystine-glutamate antitransporter. These multiple actions of minocycline and n-acetylcysteine have made them attractive candidates to treat traumatic brain injury. When first dosed within the one hour after injury, either minocycline or n-acetylcysteine improves a diverse set of therapeutic outcome measures in multiple traumatic brain injury animal models. A small number of clinical

关键词： clinical trial outcome measures preclinical testing rodent models of traumatic brain injury therapeutic time window

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Isolated Bell's palsy-An unusual presentation of dengue infection

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Asian Pacific Journal of Tropical Medicine 2013年第1期6卷 82-84页

作者： Soumia peter Malhotra n peter P Sood R Department of Medicine Christian Medical College & Hospital Department of Radiodiagnosis Christian Medical College & Hospital

Dengue fever is a very common arthropod-borne infection in tropical *** complications in dengue fever are relatively uncommon and among these,isolated cranial neuropathies have been reported only very *** present an unusual neurological complication of Bell’s palsy(lower motor neuron 7 th nerve palsy) associated with dengue *** the best of our knowledge,there have been very few documented cases of Flavivirus causing isolated Bell’s palsy.

关键词： Dengue infection Bell’s palsy

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