检索结果-南通市图书馆

An expectation–maximization algorithm for estimating proportions of deletions among bacterial populations with application to study antibiotic resistance gene transfer in Enterococcus faecalis

引用

marine Life Science & Technology 2023年第1期5卷 28-43页

作者： Yu Zhang Cong Zhang Wenwen huo Xinlei Wang michael Zhang kelli Palmer min Chen School of mathematical Sciences Ocean University of ChinaQingdao266000China Department of mathematical Sciences University of Texas at DallasRichardsonTX75080USA Department of Biological Sciences University of Texas at DallasRichardsonTX75080USA Department of Statistical Science Southern Methodist UniversityDallasTX75205USA mOE Key Laboratory of Bioinformatics Tsinghua UniversityBeijing100084China Department of Population and Data Sciences UT Southwestern Medical CenterDallasTX75390USA

The emergence of antibiotic resistance in bacteria limits the availability of antibiotic choices for treatment and infection control,thereby representing a major threat to human *** de novo mutation of bacterial genomes is an essential mechanism by which bacteria acquire antibiotic ***,deletion mutations within bacterial immune systems,ranging from dozens to thousands of base pairs(bps)in length,have been associated with the spread of antibiotic *** current methods for evaluating genomic structural variations(SVs)have concentrated on detecting them,rather than estimating the proportions of populations that carry distinct SVs.A better understanding of the distribution of mutations and subpopulations dynamics in bacterial populations is needed to appreciate antibiotic resistance evolution and movement of resistance genes through ***,we propose a statistical model to estimate the proportions of genomic deletions in a mixed population based on Expectation–maximization(Em)algorithms and next-generation sequencing(NGS)*** method integrates both insert size and split-read mapping information to iteratively update estimated *** proposed method was evaluated with three simulations that demonstrated the production of accurate *** proposed method was then applied to investigate the horizontal transfers of antibiotic resistance genes in concert with changes in the CRISPR-Cas system of ***.

关键词： Bacterial genomes CRISPR-Cas system Antibiotic resistance Em algorithm Proportion estimation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Identification of proteins involved in lignocellulose degradation using in gel zymogram analysis combined with mass spectroscopy-based peptide analysis of gut proteins from larval Asian Ionghorned beetles, Anoplophora glabripennis

引用

Insect Science 2010年第3期17卷 253-264页

作者： Scott m. Geib ming Tien kelli hoover Departments of Biochemistry and molecular Biology Departments of Entomology The Pennsylvania State University University Park Pennsylvania USA

Enzyme activities toward lignocellulose substrates were analyzed in the gut of larval Asian longhorned beetle （Anoplophora glabripennis）. Total protein was extracted from gut contents of wild collected larvae from an invasive population in Worchester, mA, USA. From these protein extracts, lignocellulolytic activities were measured （β-1,4- endoglucanase,β-1,4-glucosidase and birch wood xylanase）.β-1,4-glucosidase activity was 0.075 μmol glucose/mg protein per min, endoglucanase activity was measured at 0.41/zmol glucose/mg protein per min and xylanase activity was 0.058μmol xylose/mg protein per min. To identify specific enzymes that may provide these activities, zymogram analysis was performed to detect enzymes active toward carboxymethyl cellulose （CmC）, 4-methylumbelliferyl-β-D-glueopyranoside and birch wood xylan. Three protein bands were found to be active toward CmC, three displayed β-1,4-glucosidase, and one displayed xylanase activity. Proteins from active bands from these zymograms were then identified by in-gel trypsin digestions followed by peptide identification by matrix-assisted laser desorption ionization - time of flight - time of flight mass spectrometry （mS）. A custom A. glabripennis transcriptome database was used for peptide identification, giving highly significant matches in all mS analyses. These matches were then searched against the National Center for Biotechnology Information database to provide annotation to the transcripts and provide possible classification. From these analyses, we were able to detect enzymes active toward cellulose and xylan, and proteins putatively involved in lignocellulose degradation in the gut of this wood-feeding insect. Future research will be focused on characterizing these enzymes through cloning and expression experiments and understanding how the lignocellulose degradation system functions in the gut of this insect.

关键词： beta-glucosidase cellulase Cerambycidae endoglucanase proteomics xylanase

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Empirical assessment of adaptation to climate change impacts of mountain households:development and application of an Adaptation Capability Index

引用

Journal of mountain Science 2016年第8期13卷 1503-1514页

作者： Rajiv PANDEY Nandini mAIThANI Roberta ARETANO Giovanni ZURLINI kelli m ARChIE Ajay K GUPTA Vishnu Prasad PANDEY Biodiversity and Climate Change Division ICFREDehradun 248 006India Forest Research Institute Dehradun 248006India Department of Biological and Environmental Sciences and Technologies University of SalentoLecee 73100Italy Climate Change Research Institute Victoria University of WellingtonWellington 6140New Zealand Asian Institute of Technology and management(AITm) Lalitpur 44700Nepal

The present study proposes an index to assess the potential for adaptation to climate change for households in the mountainous regions. The index provides a realistic approach to recognize social and natural factors which contribute to successful adaptation and addresses several household functions,such as social networking, livelihood strategy, adjustment strategies, resource availability and accessibility. The proposed Adaptation Capability Index(ACI) is analytically defined, mathematically formulated and field tested on mountainous households in urban and semi-urban regions of the Uttarakhand himalaya in India. To gather data on the topic relevant to the ACI, a household scale questionnaire was developed and administered to 120 heads of households through face-to-face interviews. The results highlight higher adaptive capability of urban households and low adaptation capacity of rural households due to poor farm productivity, low accessibility and availability of resources and technological input. Future programs and policies must include and implement regulations to remedy attributive factors responsible for higher adaptation. This paper may be applicable to other mountainous regions and may provide insights for effective adaptation strategies to climate change.

关键词：气候变化影响能力指数农村家庭自适应能力应用评价山地城市地区

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Specificity of Developmental Resistance in Gypsy moth (Lymantria dispar) to two DNA-Insect Viruses

引用

Virologica Sinica 2009年第5期24卷 493-500页

作者： kelli hoover michael J. Grove The Pennsylvania State University Department of Entomology 501 ASI Building University Park PA 16802 USA

Gypsy moth (Lymantria dispar) larvae displayed marked developmental resistance within an instar to L. dispar m nucleopolyhedrovirus (LdmNPV) regardless of the route of infection (oral or intrahemocoelic) in a previous study, indicating that in gypsy moth, this resistance has a systemic component. In this study, gypsy moth larvae challenged with the Amsacta moorei entomopoxvirus (AmEV) showed developmental resistance within the fourth instar to oral, but not intrahemocoelic, inoculation. In general, gypsy moth is considered refractory to oral challenge with AmEV, but in this study, 43% mortality occurred in newly molted fourth instars fed a dose of 5×106 large spheroids of AmEV; large spheroids were found to be more infectious than small spheroids when separated by a sucrose gradient. Developmental resistance within the fourth instar was reflected by a 2-fold reduction in mortality (18%-21%) with 5×106 large spheroids in larvae orally challenged at 24, 48 or 72 h post-molt. Fourth instars were highly sensitive to intrahemocoelic challenge with AmEV; 1PFU produced approximately 80% mortality regardless of age within the instar. These results indicate that in gypsy moth, systemic developmental resistance may be specific to LdmNPV, reflecting a co-evolutionary relationship between the baculovirus and its host.

关键词：舞毒蛾幼虫阻力昆虫病毒 DNA 核多角体病毒异性昆虫痘病毒死亡率

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Life-Threatening Pulmonary Embolism: A multidisciplinary Approach to Diagnosis and management

引用

World Journal of Cardiovascular Surgery 2013年第6期3卷 190-196页

作者： Omar m. Lattouf Kenneth Leeper h.val kelli Emory University School of medicine Atlanta USA

Current treatment of life threatening venous thrombo-embolism (VTE) has been based on general concepts dating to the early 1900s. In this manuscript a general overview of current diagnostic and therapeutic methods of VTE is presented along with the Emory University Affiliated hospitals’ experience of the surgical treatment of life threatening VTE. We retrospectively analyzed the data of twenty-seven consecutive patients who underwent pulmonary embolectomy on cardiopulmonary bypass from January 1998 through April 2010. Our results showed successful outcomes after urgent or emergent surgical pulmonary embolectomy. It encourages the choice of an early and aggressive surgical approach for large pulmonary emboli in hemodynamically unstable patients.

关键词： Cardiopulmonary Bypass Embolectomy Pulmonary Embolism/Surgery

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Inflammation Biomarkers as Predictors of Pulmonary Outcomes in Cardiac Surgical Patients

引用

Open Journal of Thoracic Surgery 2013年第4期3卷 93-102页

作者： Nadera J. Sweiss Ray Sawaqed Kenneth V. Leeper h.val m. kelli Timothy Niewold Omar m. Lattouf Emory University School of medicine Atlanta USA.

Prolonged ventilator support, pulmonary infections and the need for tracheostomies after cardiac operations are associated with increased hospital mortality, length of stay, cost of hospitalization and reduced long term survival. The objective of this study is to review the literature and develop and present an understanding of the potential role of specific pre-operatively or intraoperatively collected inflammatory biomarkers and their role as predictors of pulmonary outcomes in cardiac surgery.

关键词： CABG COPD Biomarkers

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clinical and anatomic predictors of need for repeat atrial fibrillation ablation

引用

World Journal of Cardiology 2017年第9期9卷 742-748页

作者： Yaanik Desai mathew R Levy Shahriar Iravanian Edward C Clermont h.val m kelli Robert L Eisner mikhael F El-Chami Angel R Leon David B Delurgio Faisal m merchant Emory University School of medicine Cardiology Division Department of MedicineEmory University School of Medicine Division of Cardiology Department of MedicineUniversity of Pennsylvania Department of Radiology Emory University School of Medicine

AIm To identify predictors of need for repeat procedures after initial atrial fibrillation(AF) ablation. mEThODS We identified a cohort undergoing first time AF ablation at our institution from January 2004 to February 2014 who had cardiac magnetic resonance(CmR) imaging performed prior to ablation. Clinical variables and anatomic characteristics(determined from CmR) were assessed as predictors of need for repeat ablation. The decision regarding need for and timing of repeat ablation was at the discretion of the treating physician. RESULTS From a cohort of 331 patients, 142 patients(43%) underwent repeat ablation at a mean of 13.6 ± 18.4 mo afterthe index procedure. Both male gender(81% vs 71%, P = 0.05) and lower ejection fraction(57.4% ± 10.3% vs 59.8% ± 9.4%, P = 0.04) were associated with need for repeat ablation. On pre-ablation CmR, mean pulmonary vein(PV) diameters were significantly larger in all four PVs among patients requiring repeat procedures. In multivariate analysis, increased right superior PV diameter significantly predicted need for repeat ablation(odds ratio 1.08 per millimeter increase in diameter, 95%CI: 1.00-1.16, P = 0.05). There were also trends toward significance for increased left and right inferior PV sizes among those requiring repeat *** Increased PV size predicts the need for repeat AF ablation, with each millimeter increase in PV diameter associated with an approximately 5%-10% increased risk of requiring repeat procedures.

关键词： Atrial 纤维性颤动脱离重复脱离心脏的磁性的回声成像肺的静脉成像

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Assessment of UAV Based Vegetation Indices for Nitrogen Concentration Estimation in Spring Wheat

引用

Advances in Remote Sensing 2018年第2期7卷 71-90页

作者： Olga S. Walsh Sanaz Shafian Juliet m. marshall Chad Jackson Jordan R. mcClintick-Chess Steven m. Blanscet Kristin Swoboda Craig Thompson kelli m. Belmont Willow L. Walsh Department of Plant Sciences Southwest Research and Extension Center University of Idaho Moscow ID USA Department of Entomology Plant Pathology and Nematology Idaho Falls Research and Extension Center University of Idaho Idaho Falls ID USA BASF-Chemical Co. Caldwell ID USA Take Flight UAS LLC Boise ID USA Seminis Payette ID USA vallivue high School Caldwell ID USA

Unmanned Aerial Vehicles (UAVs) have become increasingly popular in recent years for agricultural research. high spatial and temporal resolution images obtained with UAVs are ideal for many applications in agriculture. The objective of this study was to evaluate the performance of vegetation indices (VIs) derived from UAV images for quantification of plant nitrogen (N) concentration of spring wheat, a major cereal crop worldwide. This study was conducted at three locations in Idaho, United States. A quadcopter UAV equipped with a red edge multispectral sensor was used to collect images during the 2016 growing season. Flight missions were successfully carried out at Feekes 5 and Feekes 10 growth stages of spring wheat. Plant samples were collected on the same days as UAV image data acquisition and were transferred to lab for N concentration analysis. Different VIs including Normalized Difference Vegetative Index (NDVI), Red Edge Normalized Difference Vegetation Index (NDVIred edge), Enhanced Vegetation Index 2 (EVI2), Red Edge Simple Ratio (SRred edge), Green Chlorophyll Index (CIgreen), Red Edge Chlorophyll Index (CIred edge), medium Resolution Imaging Spectrometer (mERIS) Terrestrial Chlorophyll Index (mTCI) and Red Edge Triangular Vegetation Index (core only) (RTVIcore) were calculated for each flight event. At Feekes 5 growth stage, red edge and green based VIs showed higher correlation with plant N concentration compare to the red based VIs. At Feekes 10 growth stage, all calculated VIs showed high correlation with plant N concentration. Empirical relationships between VIs and plant N concentration were cross validated using test data sets for each growth stage. At Feekes 5, the plant N concentration estimated based on NDVIred edge showed one to one correlation with measured N concentration. At Feekes 10, the estimated and measured N concentration were highly correlated for all empirical models, but the model based on CIgreen was the only model that had a one to

关键词： Unmanned Aerial Vehicles and Systems (UAV) Vegetation Indices (VIs) Plant Nitrogen Concentration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

端粒缩短,再生能力与心血管预后

引用

中华高血压杂志 2016年第12期24卷 1174-1174页

作者：刘莉叶鹏 hammadah m mheid IA Wilmot K Ramadan R Abdulhadi N Alkhoder A Obideen m Pimple P Levantsevych O kelli h Shah A Sun Y Pearce B Kutner m Long Q Ward L Ko YA mohammed Kh Lin J Zhao J Bremner J Kim J Waller E Raggi P Sheps D Quyyumi A Vaccarino V

白细胞端粒长度（leucocyte telomere length,LTL）是衰老的生物标志物,较短的LTL与不良的心血管预后相关。端粒再生能力降低可能是其机制之一。骨髓来源的循环祖细胞（progenitor cells,PCs）参与组织修复和再生。该研究的目的是研究LT... 详细信息

白细胞端粒长度（leucocyte telomere length,LTL）是衰老的生物标志物,较短的LTL与不良的心血管预后相关。端粒再生能力降低可能是其机制之一。骨髓来源的循环祖细胞（progenitor cells,PCs）参与组织修复和再生。该研究的目的是研究LTL与PCs之间的关系及其对不良心血管预后的影响。方法：通过定量聚合酶链反应测定566例冠状动脉疾病（coronary artery disease, CAD）门诊患者[年龄（63±9）岁，76％为男性]的LTL。

关键词：端粒 telomere leucocyte 骨髓来源 progenitor 生物标志物祖细胞组织修复 length 四分位数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：