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杂草对作物产量损失的经验模型

植物保护学报 1991年第4期18卷 371-377页

作者：刘德立 J.V.Lovett i.r.johnson 西南农业大学农学系澳大利亚新英格兰大学

本文讨论一个描述杂草为害导致作物产量损失的经验模型。该模型能反映杂草与作物产量损失的关系特征,其参数具有显著的生物学意义。用不同来源的试验资料进行测试,结果表明,模型具有较高的预测可信度,其参数所反映的生物学意义与实际情... 详细信息

本文讨论一个描述杂草为害导致作物产量损失的经验模型。该模型能反映杂草与作物产量损失的关系特征,其参数具有显著的生物学意义。用不同来源的试验资料进行测试,结果表明,模型具有较高的预测可信度,其参数所反映的生物学意义与实际情况基本一致。

关键词：杂草作物产量损失经验模型

Comparison of a Spectral Bin and Two Multi-Moment Bulk Microphysics Schemes for Supercell Simulation:investigation into Key Processes responsible for Hydrometeor Distributions and Precipitation

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Advances in Atmospheric Sciences 2024年第5期41卷 784-800页

作者： Marcus johnson Ming XUE Youngsun JUNG Center for Analysis and Prediction of Storms University of OklahomaNormanOK 73072USA School of Meteorology University of OklahomaNormanOK 73072USA Office of Science and Technology integration National Weather ServiceSilver SpringMD 20910USA

There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical *** supercell simulations are produced using the WrF model coupled with“full”Hebrew University spectral bin MP(HU-SBM),and NSSL and Thompson bulk MP(BMP)***-SBM downdrafts are typically weaker than those of the NSSL and Thompson simulations,accompanied by less rain ***-SBM produces more cloud ice(plates),graupel,and hail than the BMPs,yet precipitates less at the *** limiting mass bins(and subsequently,particle size)of rimed ice in HU-SBM and slower rimed ice fall speeds lead to smaller melting-level net rimed ice fluxes than those of the *** from plates in HU-SBM,together with snow–graupel collisions,leads to a greater snow contribution to rain than those of the *** HU-SBM’s fall speeds using the formulations of the BMPs after aggregating the discrete bin values to mass mixing ratios and total number concentrations increases net rain and rimed ice ***,they are smaller in magnitude than bulk rain,NSSL hail,and Thompson graupel net fluxes near the ***,the melting-layer net rimed ice fluxes are reduced when the fall speeds for the NSSL and Thompson simulations are calculated using HU-SBM fall speed formulations after discretizing the bulk particle size distributions(PSDs)into spectral *** results highlight precipitation sensitivity to storm dynamics,fall speed,hydrometeor evolution governed by process rates,and MP PSD design.

关键词： precipitation spectral bin microphysics bulk microphysics parameterization microphysics processes WrF model supercell storm

iso-propyl caprylate and iso-propyl linolenate synthetic fluids as novel alternatives in deep-water drilling operations:Critical fluid properties and aerobic biodegradability assessments

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Petroleum 2024年第2期10卷 254-264页

作者： Adewale johnson Folayan Adewale Dosunmu Aleruchi Boniface Oriji Department of Petroleum and Gas Engineering University of Port HarcourtNigeria Professor of Petroleum and Gas Engineering University of Port HarcourtNigeria

Present drilling fluids for deep water wells have severe degenerative effect on the environment with high operational and disposal ***,making them less desirable in recent *** synthetic drilling fluid provides a novel environmentally friendly alternative but conventional ester-based drilling fluids exhibit high viscosities in deep-water wells causing excessive equivalent circulating density(ECD)and increased risk of lost circulation owing to narrow mud density *** study experimentally investigates the critical fluid properties and aerobic biodegradability potentials of two newly developed deep-water synthetic ester drilling fluids namely:iso-propyl caprylate(COiPE)and iso-propyl linolenate(LOiPE)synthetic fluids and their comparison with synthetic-paraffin(SP-SBF)and isomerized-olefin(iOSBF)synthetic hydrocarbon *** esters of iso-propyl caprylate and iso-propyl linolenate were produced from the isolation of ester mixtures that were obtained from the homogeneous catalytic transesterification of coconut and linseed plant oil biomass *** COiPE was isolated from the coconut oil iso-propyl ester mixture by low-pressure fractional distillation *** fractional distillation and crystallization were used to isolate the LOiPE ester from the linseed oil iso-propyl ester ***,the aerobic biodegradation investigation was conducted by a modified oxygen consumption respirometry *** GC-MS analysis of the COiPE and LOiPE showed that the former contains essentially of lower saturated carbon compounds(C8).Whereas the latter contains higher molecular weight and unsaturated carbon compounds(C18+).The COiPE and LOiPE kinematic viscosity values are in good agreement with that of the reference synthetic hydrocarbon fluid samples(SP-SBF and iO-SBF).Although,the COiPE synthetic ester has lower viscosity value owing to the presence of shorter chain and saturated carbon atoms(C8 esters).Similarly,the linolenic oil iso

关键词： Aerobic biodegradation Critical fluid properties Deep-water wells Esters'isolation:isomerized-olefin(iO-SBF) iso-propyl caprylate(COiPE) iso-propyl linolenate(LOiPE) respirometry technique Synthetic-paraffin(SP-SBF)

A 63-Year-Old Male with D-Transposition of the Great Arteries Who Had an Early Form of the Arterial Switch Operation

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Congenital Heart Disease 2024年第1期19卷 65-68页

作者： Michael A.rebolledo Jane S.Yao Jason N.johnson Umar S.Boston Benjamin r.Waller iii Division of Pediatric Cardiology Department of PediatricsThe University of Tennessee Health Science CenterThe Heart InstituteLe Bonheur Children’s HospitalMemphisUSA College of Medicine The University of Tennessee Health ScienceMemphisUSA Division of Pediatric Cardiothoracic Surgery Department of SurgeryThe University of Tennessee Health Science CenterHeart InstituteLe Bonheur Children’s HospitalMemphisUSA

We describe a 63-year-old male who appears to have undergone an early form of the arterial switch operation for D-transposition of the great arteries performed in the *** review the clinical and imaging data that support our *** had a diagnostic cardiac catheterization which demonstrated severe pulmonary hypertension responsive to epoprostenol and *** case may represent one example of the experimental surgical work done prior to *** Jatene’s description of theﬁrst successful arterial switch performed in 1975.

关键词： Adult congenital heart disease arterial switch operation great vessel anomaly imaging(all modalities)

increasing age and duration of sex work among female sex workers in South Africa and implications for HiV incidence estimation:Bayesian evidence synthesis and simulation exercise

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infectious Disease Modelling 2024年第1期9卷 263-277页

作者： Nanina Anderegg Mariette Slabbert Kholi Buthelezi Leigh F.johnson Centre for infectious Disease Epidemiology and research School of Public HealthUniversity of Cape TownSouth Africa institute of Social and Preventive Medicine University of BernSwitzerland independent Consultant PretoriaSouth Africa National Sex Workers Movement in South Africa

introduction:in sub-Saharan Africa,accurate estimates of the HiV epidemic in female sex workers are crucial for effective prevention and care *** estimates are typically derived from mathematical models that assume certain demographic and behavioural characteristics like age and duration of sex work to remain constant over *** reviewed this assumption for female sex workers in South ***:We reviewed studies that reported estimates on either the age or the duration of sex work among female sex workers in South *** used Bayesian hierarchical models to synthesize reported estimates and to study time *** a simulation exercise,we also investigated the potential impact of the"constant age and sex work duration"-assumption on estimates of HiV ***:We included 24 different studies,conducted between 1996 and 2019,contributing 42 estimates on female sex worker age and 27 estimates on sex work *** was evidence suggesting an increase in both the duration of sex work and the age of female sex workers over *** to the fitted models,over each decade the expected duration of sex work increased by 55.6%(95%-credible interval[Cri]:23.5%–93.9%)and the expected age of female sex workers increased by 14.3%(95%-Cri:9.1%–19.1%).Over the 23-year period,the predicted mean duration of sex work increased from 2.7 years in 1996 to 7.4 years in 2019,while the predicted mean age increased from 26.4 years to 32.3 *** for these time trends in the simulation exercise resulted in a notable decline in estimated HiV incidence rate among sex workers over *** decline was significantly more pronounced than when assuming a constant age and duration of sex ***:in South Africa,age and duration of sex work in female sex workers increased over *** this trend might be influenced by factors like expanding community mobilization and improved rights advocacy,the ongoing criminalisation,stigmatisation of s

关键词： Female sex workers Mathematical modelling South Africa HiV

rescue from complications after pancreaticoduodenectomies at a low-volume Caribbean center:Value of tailored peri-pancreatectomy protocols

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 681-688页

作者： Shamir O Cawich Elijah Dixon Parul J Shukla Shailesh V Shrikhande rahul r Deshpande Fawwaz Mohammed Neil W Pearce Wesley Francis Shaneeta johnson Johann Bujhawan Department of Surgery University of the West IndiesSt Augustine 000000Trinidad and Tobago Department of Surgery Faculty of MedicineUniversity of CalgaryCalgaryAlberta T2N2T9Canada Department of Surgery Weill Cornell Medical CollegeNew YorkNY 10065United States Department of Surgical Oncology Tata Memorial CenterHomi Bhabha National UniversityMumbai 400012India Department of Surgery Manchester Royal InfirmaryManchester M139WLUnited Kingdom University Surgical Unit Southampton General HospitalSouthampton SO166YDUnited Kingdom Department of Surgery University of the West IndiesNassau N-1184Bahamas Department of Surgery Morehouse School of MedicineAtlantaGA 30310United States Department of Surgery General Hospital in Port of SpainPort of Spain 000000Trinidad and Tobago

BACKGrOUND Pancreaticoduodenectomy(PD)is a technically complex operation,with a re-latively high risk for *** ability to rescue patients from post-PD complications is as a recognized quality *** protocols were instituted at our low volume facility in the year *** To document the rate of rescue from post-PD complications with tailored protocols in place as a measure of *** A retrospective audit was performed to collect data from patients who experienced major post-PD complications at a low volume pancreatic surgery unit in Trinidad and Tobago between January 1,2013 and June 30,***-dardized definitions from the international Study Group of Pancreatic Surgery were used to define post-PD complications,and the modified Clavien-Dindo classification was used to classify post-PD *** Over the study period,113 patients at a mean age of 57.5 years(standard deviation[SD]±9.23;range:30-90;median:56)underwent PDs at this *** complications were recorded in 33(29.2%)patients at a mean age of 53.8 years(SD:±7.9).Twenty-nine(87.9%)patients who experienced major morbidity were salvaged after aggre-ssive treatment of their ***(3.5%)died from bleeding pseudoaneurysm(1),septic shock secondary to a bile leak(1),anastomotic leak(1),and myocardial infarction(1).There was a significantly greater salvage rate in patients with American Society of Anesthesiologists scores≤2(93.3%vs 25%;P=0.0024).CONCLUSiON This paper adds to the growing body of evidence that volume alone should not be used as a marker of quality for patients requiring *** low volumes at our facility,we demonstrated that 87.9%of patients were rescued from major *** attributed this to several factors including development of rescue protocols,the competence of the pancreatic surgery teams and continuous,and adaptive learning by the entire institution,cul-minating in the development of tailored peri-pancreatectomy protoc

关键词： Pancreas Complication rescue Failure Morbidity Mortality Pancreaticoduodenectomy

integrins and their potential roles in mammalian pregnancy

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Journal of Animal Science and Biotechnology 2024年第1期15卷 1-19页

作者： Gregory A.johnson robert C.Burghardt Fuller W.Bazer Heewon Seo Joe W.Cain Department of Veterinary integrative Biosciences School of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityCollege StationTX 77843‑4459USA Department of Animal Science College of Agriculture and Life SciencesTexas A&M UniversityCollege StationTX 77843‑2471USA

integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin adhesion complexes(iACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the sc

关键词： Humans implantation integrins Pigs Pregnancy rodents Sheep

Antimicrobial stewardship and targeted therapies in the changing landscape of maternal sepsis

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Journal of intensive Medicine 2024年第1期4卷 46-61页

作者： Nishel M Shah Esmita Charani Damien Ming Fook-Choe Cheah Mark r johnson Department of Metabolism Digestion and ReproductionImperial College LondonChelsea and Westminster HospitalLondonUK Health Protection research Unit in Healthcare Associated infection and Antimicrobial resistance Imperial College LondonLondonUK Division of infectious Diseases and HiV Medicine Department of MedicineGroote Schuur HospitalUniversity of Cape TownCape TownSouth Africa Department of infectious Diseases Imperial College LondonChelsea and Westminster HospitalLondonUK Department of Paediatrics Faculty of MedicineUniversiti Kebangsaan Malaysia Medical CentreKuala LumpurMalaysia

Pregnant and postnatal women are a high-risk population particularly prone to rapid progression to sepsis with significant morbidity and mortality ***,severe maternal infections can have a serious detrimental impact on neonates with almost 1 million neonatal deaths annually attributed to maternal infection or *** this review we discuss the susceptibility of pregnant women and their specific physiological and immunological adaptations that contribute to their vulnerability to sepsis,the implications for the neonate,as well as the issues with antimicrobial stewardship and the challenges this poses when attempting to reach a balance between clinical care and urgent ***,we review advancements in the development of pregnancy-specific diagnostic and therapeutic approaches and how these can be used to optimize the care of pregnant women and neonates.

关键词： Sepsis Pregnancy immunology Cardiovascular Personalised medicine Antibiotic stewardship

Spatial distribution and potential ecological and health risks associated with heavy metals in the ijero-Ekiti mining site,Nigeria

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regional Sustainability 2024年第1期5卷 26-41页

作者： johnson Adedeji OLUSOLA Adeyinka Oluyemi ATUrAMU Olufunke ASAOLU Olusesan Sola OGUNLEYE Department of Geography and Planning Science Ekiti State UniversityAdo Ekiti360211Nigeria institute of Ecology and Environmental Studies Obafemi Awolowo UniversityIle IfeOsun State220101Nigeria Department of Geology(Climate Change and Paleobiology Group) Ekiti State UniversityAdo Ekiti360211Nigeria Environmental Natural Resources and Blue EconomyEurope and Central AsiaWorld Bank GroupWashington D.C.20433the USA

Artisanal gold mining,a labor-intensive and antiquated technique,is a growing industry and the source of income for rural communities all over the ***,artisanal gold mining has potential negative and long-term effects on economy,environment,and *** study collected soil samples from 16 sample points including a control point to examine the pollution degrees and spatial distribution of heavy metals,as well as ecological and health risks associated with heavy metal pollution in the ijero-Ekiti mining site,*** information System(GiS)and remote sensing technologies were used to identify regions with high concentrations of heavy metals and assess the environmental impact of gold mining *** results show that the mean heavy metal concentrations of 16 soil pointa are 8.94(±5.97)mg/kg for As,0.18(±0.54)mg/kg for Cd,0.11(±1.06)mg/kg for Co,14.32(±3.43)mg/kg for Cr,6.89(±0.64)mg/kg for Cu,48.92(±11.77)mg/kg for Fe,135.81(±30.75)mg/kg for Mn,5.92(±0.96)mg/kg for Ni,5.72(±1.66)mg/kg for Pb,and 13.94(±1.38)mg/kg for *** study reveals that heavy metal concentration in soils follows the order of Mn>Fe>Cr>Zn>As>Cu>Ni>Pb>Co>*** analysis of soil samples indicates that 3 principal components(PCs)account for 70.008%of the total variance and there are strong positive correlations between various pairs of heavy *** total potential ecological risk index(309.599)in the study area is ***-carcinogenic risk suggests that there may be long-term health impacts on people who work in the mining areas due to chronic exposure to the *** on the study,the hazard index of carcinogenic health risks associated with heavy metals through ingestion is 520.00×10^(–4).Dermal contact from As and Cr also increases the risk of cancer,with the highest hazard index value of 18.40×10^(–4).The lowest exposure pathway,with the hazard index value of 0.68×10^(–4),indicates that the inhalation of heavy metals has a comparatively low risk of can

关键词： Artisanal gold mining Heavy metals Exposure pathway Potential ecological risk Geo-accumulation index ijero-Ekiti mining site