检索结果-南通市图书馆

Explaining First-Year Seedling Survival from Quality Distributions of Bare-Root Seedlings and Microsites in Industrial Plantations

引用

Open Journal of Forestry 2018年第3期8卷 362-379页

作者： Puskar n. Khanal Thomas J. dean Scott D. Roberts Donald L. Grebner Thomas J. Straka Department of Forestry and Environmental Conservation Clemson University Clemson SC USA School of Renewable natural Resources Louisiana State University Agricultural Center Baton Rouge LA USA Department of Forestry Mississippi State University Starkville MS USA

First-year seedling survival impacts all subsequent management planning in plantation forestry. Descriptive statistics of first-year seedling survival data from the Louisiana Department of Agriculture and Forestry (LDAF) indicated that survival success reaches a plateau at between 79% - 85% under normal weather conditions. We provide an explanation for this plateau based on an analysis of seedling and microsite qualities involved in operational pine plantations by: 1) using a conceptual model demonstrating how variation in seedling quality and microsite quality interact to determine plantation survival, 2) presenting an example to characterize quality distributions of seedling and microsite qualities, and 3) comparing model outcomes based on measured distributions to realistic values of first-year survival. Simulation results indicated that consistent survival could result from random pairings of initial seedling and site quality distributions. LDAF data analysis indicated that 72% of seedlings were associated with the most frequent quality class that comprised seedlings with stem caliper between 3.2 to 4.7 mm and average stem height and volume of 25.75 cm and 3.43 cm3, respectively. Similarly, assessment of microsites at planting sites in Southeast Louisiana indicated that 48% of planted seedlings were associated with the most frequent microsite quality class which supported first-year height increment between 9 to 29 cm. Modelling of current operational practice indicated that using seedlings with larger caliper size would increase first year survival, but would result in higher establishment costs. The conceptual model could be modified to for use in other regions regardless of species types involved.

关键词： Seedling Survival Site Quality Microsite Simulation

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

“It All Goes Back to the Services”: A Rural/Urban Comparison of Service Providers’ Perceptions of Challenges and Facilitators to Disability Services

引用

Open Journal of Preventive Medicine 2015年第10期5卷 434-440页

作者： Moya L. Alfonso Ashley Walker Akrati Gupta Joseph Telfair gavin Colquit Department of Community Health Georgia Southern University Statesboro GA USA Department of Health and Kinesiology Georgia Southern University Statesboro GA USA

Purpose: The purpose of this qualitative study was to explore rural/urban differences in service providers’ perceptions of challenges and facilitators to services for children with special health care needs (CSHn) and their families in southeast Georgia. Methodology: A total of 23 individual interviews were conducted with service providers in one rural county in southeast Georgia (n = 12) and in one urban county in north central Georgia (n = 11). Interviews were based on the national Survey of Children with Special Health Care needs 2009-2010 survey. All interviews were audio recorded, transcribed and coded with the intent of identifying themes and illustrative quotes. Findings: Service providers discussed a variety of challenges to accessing services related to socioeconomic status and the transition out of the school system. Urban and rural service providers’ perceptions were similar overall, with the exception of lack of transportation and access to a variety of services in rural area. Service providers overcome challenges through identifying parents’ needs and limitations and adapting service provision. Some of the facilitators mentioned by both urban and rural service providers are availability of transportation and resources. Practical Implications: The results of this study provide public health practice and policy implications that could guide the pathways of targeted interventions to improve the access and availability of variety of services for CSHCn. Originality/value of paper: This paper represents an in-depth exploration of service provider’s perceptions of challenges and facilitators related to service provision for children with special healthcare needs.

关键词： Disability Adolescents Qualitative Access Service Service Providers

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

人类T型钙通道α_(1H)亚单位基因在细胞增殖中的功能研究

引用

Acta Genetica Sinica 2002年第8期29卷 659-665页

作者：王跃群 Brooks gavin 朱传柄袁婺洲李永青吴秀山湖南师范大学生命科学学院蛋白质化学及发育生物学教育部重点实验室长沙410081 英国雷丁大学动物及微生物系

将人类T型钙通道α1H 亚单位基因 (CACnA1H)cDnA转染到HEK 2 93(humanembroyonickidney)细胞系得到稳定过量表达的细胞株 ,以此为体外模型来研究T型钙通道在细胞增殖中的直接作用。RT -PCR和标准全细胞膜片钳记录分别从mRnA转录水平和T... 详细信息

将人类T型钙通道α1H 亚单位基因 (CACnA1H)cDnA转染到HEK 2 93(humanembroyonickidney)细胞系得到稳定过量表达的细胞株 ,以此为体外模型来研究T型钙通道在细胞增殖中的直接作用。RT -PCR和标准全细胞膜片钳记录分别从mRnA转录水平和T型钙通道蛋白功能水平验证了α1H 亚单位的过量表达。生长曲线结果表明 ,T型钙通道α1H 亚单位基因的过量表达能显著促进HEK - 2 93细胞增殖 ,将细胞群体倍增时间从对照细胞的 2 2 1± 1.1h缩短到稳定转染细胞的 14 0± 0 .4h ,细胞群体倍增时间缩短了约 8h ;流式细胞分析结果表明 ,在稳定转染细胞处于S期的细胞百分率比对照细胞高 ,相反地处于G1 期的百分率比对照细胞低 ,以上结果证明了过量表达T型钙通道亚单位α1H 基因能促进细胞增殖。Western印迹结果提示 ,T型钙通道α1H 亚单位基因表达产物是通过某种信号途径 ,提高了与细胞周期有关基因 (CDK2、cyclinA和cyclinE)的蛋白质表达水平 ,从而刺激了细胞周期的进程。

关键词：人类 T型钙通道α1H亚单位基因细胞增殖功能 HEK-293细胞机制血管疾病

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

Effect of oxygen and nitrogen functionalization on the physical and electronic structure of graphene

引用

nano Research 2015年第8期8卷 2620-2635页

作者： Alexander J. Marsden Peter Brommer James J. Mudd M. Adam Dyson Robert Cook Maria Asensio Jose Avila Ana Levy Jeremy Sloan David Quigley gavin R. Bell neil R. Wilson Department of Physics University of Warwick Coventry UK Centre for Scientific Computing University of Warwick Coventry UK Synchrotron SOLEIL L'Orme des Merisiers Saint Aubin-BP 48 91192 Gifsur Yvette Cedex France

Covalent functionalization of graphene offers opportunities for tailoring its properties and is an unavoidable consequence of some graphene synthesis techniques. However, the changes induced by the functionalization are not well understood. By using atomic sources to control the extent of the oxygen and nitrogen functionalization, we studied the evolution in the structure and properties at the atomic scale. Atomic oxygen reversibly introduces epoxide groups whilst, under similar conditions, atomic nitrogen irreversibly creates diverse functionalities including substitutional, pyridinic, and pyrrolic nitrogen. Atomic oxygen leaves the Fermi energy at the Dirac point （i.e., undoped）, whilst atomic nitrogen results in a net n-doping; however, the experimental results are consistent with the dominant electronic effect for both being a transition from delocalized to localized states, and hence the loss of the signature electronic structure of graphene.

关键词： graphene functionalization chemical vapor deposition density functional theory

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

一种稳定易行的创伤性颅脑损伤模型的构建和评估

引用

中华神经医学杂志 2018年第5期17卷 469-474页

作者：林桂清郭阳梁凤银 gavin Sunnassee 裴中谭盛南方医科大学珠江医院神经内科广州510282 中山大学附属第一医院神经科广州510080

目的构建并评估一种可同时模拟运动和认知障碍的小鼠创伤性颅脑损伤（TBI）模型. 方法 24只健康雄性C57BL/6小鼠按随机数字表法分为假手术组和TBI组,每组12只.TBI组小鼠参照并改良压缩损伤模型的方法制备TBI模型,假手术组小鼠进行相同... 详细信息

目的构建并评估一种可同时模拟运动和认知障碍的小鼠创伤性颅脑损伤（TBI）模型. 方法 24只健康雄性C57BL/6小鼠按随机数字表法分为假手术组和TBI组,每组12只.TBI组小鼠参照并改良压缩损伤模型的方法制备TBI模型,假手术组小鼠进行相同操作,但不进行损伤.造模后1、3、7、14、21、28d采用转棒实验和平衡木实验评估小鼠的运动能力;造模后28、29、30、31、32、33 d采用水迷宫实验测试小鼠的学习和记忆能力;造模后34 d尼氏染色检测小鼠脑组织病理改变情况,免疫荧光染色检测小鼠脑组织胶质纤维酸性蛋白（GFAP）、离子钙接头蛋白-1（Iba-1）的表达以观察胶质细胞的增生情况. 结果造模后1、3、7、14、21、28 d TBI组小鼠的潜伏期明显低于假手术组,右后肢出错步数明显多于假手术组,差异均有统计学意义（P＜0.05）;造模后30、31、32d TBI组小鼠逃避潜伏期明显长于假手术组,造模后33 d TBI组小鼠穿越原平台位置的次数明显少于假手术组,差异均有统计学意义（P＜0.05）;假手术组小鼠脑组织损伤体积低于TBI组[（0.55±0.06）％ vs.（16.90±1.14）％],差异有统计学意义（P＜0.05）;TBI组、假手术组小鼠病灶周围星形胶质细胞数分别为（101.40±6.18）个/mm2、（20.17±1.55）个/mm2,小胶质细胞数目分别为（119.20±6.28）个/mm2、（23.58±1.72）个/mm2,差异均有统计学意义（P＜0.05）. 结论本实验构建的简便、具有良好重复性和稳定的运动和认知障碍表现的TBI模型,符合中度TBI的病理学改变,可推广用于TBI的动物实验研究.

关键词：创伤性颅脑损伤模型动物运动障碍认知障碍

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

A Randomized Comparison of a Parker Endotracheal Tube and a Standard Tube Oriented 90°Counterclockwise

引用

Open Journal of Anesthesiology 2012年第5期2卷 219-223页

作者： Wade A. Weigel Thomas C. dean Department of Anesthesiology Virginia Mason Medical Center Seattle USA.

Purpose: During oral fiberoptic intubation, advancement of an endotracheal tube (ETT) into the trachea is occasionally impeded by laryngeal structures. The curved flex tip Parker ETT has been shown to improve the likelihood of successful advancement as opposed to a standard ETT that is advanced in neutral orientation. However, a Parker tube has not been compared to a standard ETT oriented 90° counterclockwise from the neutral position. We hypothesize that fiber-optically-guided advancement of an ETT into the trachea will be more successful when using a Parker tube than a 90° counterclockwise-oriented standard ETT. Methods: This unblinded, randomized controlled trial compares the rate of successful advancement of a fiberoptically-guided endotracheal tube into the trachea. Two groups of randomly assigned patients with non-difficult airways are compared: a Parker flex-tip tube (Parker Group;n = 57) versus a standard ETT oriented 90° counterclockwise (Standard Group;n = 58). Our primary outcome is the first pass success rate of advanceing the ETT into the trachea. Results: First pass success occurred in 48 of 57 (84%) patients in the Parker Group vs. 39 of 58 (67%) of patients in the Standard Group (p = 0.0497). Conclusion: When advancing an ETT over an oral fiberoptic scope and into the trachea, a Parker curved flex tip ETT is statistically more likely to be placed successfully on the first pass than is a standard ETT oriented 90° counterclockwise.

关键词： Endotracheal Intubation Parker Mallinckrodt Fiberoptic

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

Effects of feeding a pigmented or non-pigmented diet to Arctic charr, <i>Salvelinus alpinus</i>, on flesh color and sexual maturity

引用

Open Journal of Animal Sciences 2012年第4期2卷 229-233页

作者： Mary A. Mcniven gavin F. Richardson Claude S. Pelletier 13 Advana Avenue Charlottetown Canada Coastal Zones Research Institute Shippagan Canada Department of Health Management Atlantic Veterinary College University of Prince Edward Island Charlottetown Canada

The objective of this study was to evaluate the effects of feeding pigmented feed (50 ppm astaxanthin) to diploid or triploid Arctic charr, Salvelinus alpinus, on growth rate, color of fillets, and the variability of color within fillets. Arctic charr with an average weight of 419.9 g ± 83.3 g, including both diploid (n = 72) and triploid (n = 72) fish, were allotted to each treatment: 0, 3 or 6 months of pigmented feed before slaughter. Color assessment was made using a portable reflected light colorimeter in the CIE 1976 L* a* b* color system mode. Feeding a pigmented diet to Arctic charr delayed sexual maturity in male Arctic charr and to a certain extent in females, but also slightly reduced the rate of growth. With increasing time on the pigmented diet, color parameters of the flesh increased as well as the variability in color. Triploid fish had more intense color assessments for each dietary treatment than the diploid fish.

关键词： Arctic Charr Pigment Color Maturation

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

An exploration of the relationship between wastewater viral signals and COVID-19 hospitalizations in Ottawa,Canada

引用

Infectious Disease Modelling 2023年第3期8卷 617-631页

作者： K.Ken Peng Elizabeth M.Renouf Charmaine B.dean X.Joan Hu Robert Delatolla Douglas G.Manuel Department of Statistics and Actuarial Science Simon Fraser University8888 University DrBurnabyV5A 1S6BCCanada Department of Statistics and Actuarial Science University of Waterloo200 University Ave WWaterlooN2L 3G1ONCanada Department of Civil Engineering University of Ottawa75 Laurier Ave.EOttawaK1N 6N5ONCanada The Ottawa Hospital Research Institute 1053 Carling AveOttawaK1Y 4E9ONCanada Department of Family Medicine University of Ottawa75 Laurier Ave.EOttawaK1N 6N5ONCanada School of Epidemiology and Public Health University of Ottawa75 Laurier Ave.EOttawaK1N 6N5ONCanada

Monitoring of viral signal in wastewater is considered a useful tool for monitoring the burden of COVID-19,especially during times of limited availability in *** have shown that COVID-19 hospitalizations are highly correlated with wastewater viral signals and the increases in wastewater viral signals can provide an early warning for increasing hospital *** association is likely nonlinear and *** project employs a distributed lag nonlinear model(DLnM)(Gasparrini et al.,2010)to study the nonlinear exposure-response delayed association of the COVID-19 hospitalizations and SARS-CoV-2 wastewater viral signals using relevant data from Ottawa,*** consider up to a 15-day time lag from the average of SARS-CoV n1 and n2 gene concen-trations to COVID-19 *** expected reduction in hospitalization is adjusted for vaccination efforts.A correlation analysis of the data verifies that COVID-19 hospital-izations are highly correlated with wastewater viral signals with a time-varying *** DLnM based analysis yields a reasonable estimate of COVID-19 hospitalizations and enhances our understanding of the association of COVID-19 hospi-talizations with wastewater viral signals.

关键词： Wastewater surveillance COVID-19 vaccination effectiveness Distributed lag nonlinear model Time varying correlation

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

不同耕作方式对内蒙古旱作农田土壤性状及作物产量的影响

引用

生态学杂志 2010年第2期29卷 295-302页

作者：孙建刘苗李立军刘景辉 KEnnETH dean Sayre 内蒙古农业大学农学院呼和浩特010018 国际玉米小麦改良中心墨西哥06600

2005—2008年在内蒙古清水河县进行了定位试验,研究了不同耕作方式下土壤微生物量及土壤营养指标、作物产量的年际变化。结果表明:免耕有利于提高土壤微生物量碳、氮、磷含量,2007和2008年不同耕作方式0～10cm土层土壤微生物量均表现为... 详细信息

2005—2008年在内蒙古清水河县进行了定位试验,研究了不同耕作方式下土壤微生物量及土壤营养指标、作物产量的年际变化。结果表明:免耕有利于提高土壤微生物量碳、氮、磷含量,2007和2008年不同耕作方式0～10cm土层土壤微生物量均表现为免耕留高茬覆盖>免耕留低茬覆盖>免耕留高茬>免耕留低茬>传统耕作;免耕有利于提高土壤有机质和土壤养分含量,2007和2008年不同耕作方式0～10cm土层土壤有机质和养分含量均表现为免耕留高茬覆盖>免耕留低茬覆盖>免耕留高茬>免耕留低茬>传统耕作,实施免耕的前3年,玉米产量不稳定,甚至造成玉米减产,第4年免耕增产效应有所显现;不同保护性方式下土壤指标与玉米产量之间的相关度较好,通径分析得知土壤全氮、全磷、速效磷及微生物量碳对玉米产量起直接作用,其中尤以土壤微生物量碳的作用最大;免耕有利于改善内蒙古农田旱作区的土壤生态环境,提高土壤肥力。

关键词：耕作方式土壤性状作物产量旱作农田内蒙古

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

不同耕作方式对内蒙古旱作农田土壤微生物量和作物指标的影响

引用

生态学杂志 2009年第11期28卷 2279-2285页

作者：孙建刘苗李立军刘景辉 KEnnETH dean Sayre 内蒙古农业大学呼和浩特010018 国际玉米小麦改良中心墨西哥06600

研究了不同耕作方式下土壤微生物量碳、氮、磷及玉米全生育期叶面积指数、株高和干物质积累量的动态变化,并对土壤指标与作物指标之间的关系进行分析。结果表明:免耕有利于提高土壤微生物量碳、氮、磷含量。不同处理微生物量均表现为:... 详细信息

研究了不同耕作方式下土壤微生物量碳、氮、磷及玉米全生育期叶面积指数、株高和干物质积累量的动态变化,并对土壤指标与作物指标之间的关系进行分析。结果表明:免耕有利于提高土壤微生物量碳、氮、磷含量。不同处理微生物量均表现为:免耕留高茬覆盖>免耕留低茬覆盖>免耕留高茬>免耕留低茬>传统耕翻;土壤微生物量碳、氮、磷含量随土层深度的增加而呈降低趋势。除传统耕翻微生物量碳在10～20cm土层深度含量提高外,其他处理微生物量碳、氮、磷均表现为0～10cm>10～20cm>20～30cm>30～40cm土层深度;土壤生物量碳、氮、磷随季节的变化趋势基本一致,不同处理土壤生物量含量均为7月份含量最高、6月份次之、10月份最低;叶面积指数全生育期呈单峰曲线变化,株高和干物质积累呈S曲线变化。不同处理之间作物指标均表现为免耕留高茬覆盖>免耕留低茬覆盖>免耕留高茬>免耕留低茬>传统耕翻;土壤微生物量与作物指标之间的相关度较高,特别是微生物量磷,土壤微生物量在一定程度上可以反映作物的生长状况。研究结果能够很好地揭示在黄河流域内蒙古农田旱作区实施免耕的优势。

关键词：耕作方式内蒙古旱作农田土壤微生物量作物指标

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

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

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：