检索结果-南通市图书馆

Does Selection for Seedling Tiller Number in Perennial Biomass Feedstocks Translate to Yield and Quality Improvements in Mature Swards?

引用

American j.urnal of Plant Sciences 2023年第11期14卷 1223-1234页

作者： Robert B. Mitchell Kenneth P. Vogel susan j. tunnell j.mes L. Stubbendieck Wheat Sorghum and Forage Research Unit USDA-ARS Lincoln NE USA Department of Agronomy and Horticulture University of Nebraska Lincoln NE USA

Breeding for seedling traits in herbaceous perennial biomass feedstocks that translate into increased biomass yield or quality in established swards could accelerate the development of perennial grass cultivars for bioenergy or forage. In previously reported research, breeding for single large tillers (ST) or multiple tillers (MT, ≥3) six weeks after planting for two generations in big bluestem (Andropogon gerardii Vitman) and switchgrass (Panicum virgatum L.) base populations produced ST and MT populations that differed significantly for seedling and mature plant traits including biomass yield in spaced planted nurseries. Our obj.ctive was to evaluate these ST and MT populations in sward trials to determine the effect of these genetic changes on biomass yield and quality when the plants were grown in competitive sward conditions. Big bluestem monocultures of the base, ST, and MT populations were evaluated at three locations in Nebraska in 2001 and 2002 as randomized complete block experiments with four replicates. Switchgrass monocultures of the base, ST, and MT populations were evaluated in 2003, 2004, and 2005 near Mead, NE as a randomized complete block with six replicates. In both big bluestem and switchgrass, the ST and MT populations did not consistently differ from the base population or each other for biomass yield or forage quality. These results demonstrate the importance of evaluating perennial grasses in sward trials and not relying solely on greenhouse-grown plants or space-planted nurseries to develop selection criteria and make selection decisions.

关键词： Seedling Tiller Number Perennial Biomass

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

Contribution of national bioassessment approaches for assessing ecological water security： an AUSRIVAS case study

引用

Frontiers of Environmental Science & Engineering 2013年第5期7卷 669-687页

作者： susan j. NICHOLS Fiona j. DYER Institute for Applied Ecology and MDBfutures CRN University of Canberra Canberra ACT 2601 Australia

River managers in Australia are managing in the face of extremes to provide security of water supply for people, production and the environment. Balancing the water requirements of people, environments and econo- mies requires that water security is viewed holistically, not j.st in terms of the water available for human consump- tion. Common definitions of water security focus on the needs of both humans and ecosystems for purposes such as drinking, agriculture and industrial use, and to maintain ecological values. Information about achieving water security for the environment or ecological purposes can be a challenge to interpret because the watering require- ments of key ecological processes or assets are not well understood, and the links between ecological and human values are often not obvious to water users. Yet the concepts surrounding river health are inherently linked to holistic concepts of water security. The measurement of aquatic biota provides a valuable tool for managers to understand progress toward achieving ecological water security obj.ctives. This paper provides a comprehensive review of the reference condition approach to river health assessment, using the development of the Australian River Assessment System （AUSRIVAS） as a case study. We make the link between the biological assessment of river health and assessment of ecological water security, and suggest that such an approach provides a way of reporting that is relevant to the contribution made by ecosystems to water security. The reference condition approach, which is the condition representative of minimally disturbed sites organized by selected physical, chemical, and biological characteristics, is most important for assessing ecological water security obj.ctives.

关键词： ecological water security biological assessment river health

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

Cell Wall Microstructure Analysis Implicates Hemicellulose Polysaccharides in Cell Adhesion in Tomato Fruit Pericarp Parenchyma

引用

Molecular Plant 2009年第5期2卷 910-921页

作者： j.se j. Ordaz-Ortiz susan E. Marcus j. Paul Knox Centre for Plant Sciences Faculty of Biological Sciences University of Leeds Leeds LS2 9JT United Kingdom

Methods developed to isolate intact cells from both unripe and ripe tomato fruit pericarp parenchyma have allowed the cell biological analysis of polysaccharide epitopes at the surface of separated cells. The LM7 pectic homogalacturonan epitope is a marker of the j.nctions of adhesion planes and intercellular spaces in parenchyma systems. The LM7 epitope persistently marked the former edge of adhesion planes at the surface of cells separated from unripe and ripened tomato fruit and also from fruits with the Cnr mutation. The LM 11 xylan epitope was associated, in sections, with cell walls lining intercellular space but the epitope was not detected at the surface of isolated cells, being lost during cell isolation. The LM15 xyloglucan epitope was present at the surface of cells isolated from unripe fruit in a pattern reflecting the former edge of cell adhesion planes/intercellular space but with gaps and apparent breaks. An equivalent pattern of LM15 epitope occurrence was revealed at the surface of cells isolated by pectate lyase action but was not present in cells isolated from ripe fruit or from Cnr fruit. In contrast to wild-type cells, the LM5 galactan and LM21 mannan epitopes occurred predominantly in positions reflecting intercellular space in Cnr, suggesting a concerted alteration in cell wall microstructure in response to this mutation. Galactanase and mannanase, along with pectic homogalacturonan-degrading enzymes, were capable of releasing cells from unripe fruit parenchyma. These observations indicate that hemicellulose polymers are present in architectural contexts reflecting cell adhesion and that several cell wall polysaccharide classes are likely to contribute to cell adhesion/cell separation in tomato fruit pericarp parenchyma.

关键词： Cell walls fruit development tomato cell adhesion cell separation polysaccharide.

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

Using classification assignment rules to assess land-use change impacts on forest biodiversity at local-to-national scales

引用

Forest Ecosystems 2018年第2期5卷 162-176页

作者： Kathrin Affeld susan K. Wiser Ian j. Payton Miquel DeCaceres Manaaki Whenua - Landcare Research PO Box 69040 Lincoln 7640 New Zealand Lincoln University PO Box 85084 Lincoln 7647 New Zealand Forest Science Centre of Catalonia Ctra. Sant Llorenc km.2 E-25280 Solsona Spain

Background： Ecosystem representation is one key component in assessing the biodiversity impacts of land-use changes that will irrevocably alter natural ecosystems. We show how detailed vegetation plot data can be used to assess the potential impact of inundation by a proposed hydroelectricity dam in the Mokihinui gorge, New Zealand, on representation of natural forests. Specifically we ask： 1） How well are the types of forest represented Locally, regionally, and nationally; and 2） How does the number of distinct communities （i.e. beta diversity） in the target catchment compare with other catchments nationally？ Methods： For local and regional comparisons plant species composition was recorded on 45 obj.ctively located 400 m2 vegetation plots established in each of three gorges, with one being the proposed inundation area of the Mokihinui lower gorge. The fuzzy classification framework of noise clustering was used to assign these plots to a specific alliance and association of a pre-existing national-scale classification. NationaLly, we examined the relationship between the number of alliances and associations in a catchment and either catchment size or the number of plots per catchment by fitting Generalised Additive Models. Results： The four alliances and five associations that were observed in the Mokihinui lower gorge arepresent in the region but limited locally. One association was narrowly distributed nationally, but is the mostfrequent association in the Mokihinui lower gorge; inundation may have consequences of national importance to its long-term persistence. That the Mokihinui lower gorge area had nearly twice as many plots that could not be assigned to pre- existing alliances and associations than either the Mokihinui upper or the Karamea lower gorges and proportionally more than the national dataset emphasises the compositional distinctiveness of this gorge. These outlier plots in the Mokihinui lower gorge may be unsorted assemblages of species or reflect

关键词： Beta-diversity Biodiversity conservation Environmental impacts Ecosystem representation Hydroelectricity dams Land-use change National vegetation classification Noise clustering New Zealand NVS databank Plant community composition

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

Double Fertilization in Arabidopsis thaliana Involves a Polyspermy Block on the Egg but Not the Central Cell

引用

Molecular Plant 2008年第4期1卷 611-619页

作者： Rod j. Scott susan j. Armstrong j.mes Doughty Melissa Spielman Department of Biology and Biochemistry University of Bath Claverton Down Bath BA2 7AY United Kingdom School of Biosciences The University of Birmingham Edgbaston Birmingham B15 2TT United Kingdom

In animal reproduction, thousands of sperm may compete to fertilize a single egg, but polyspermy blocks prevent multiple fertilization that would otherwise lead to death of the embryo. In flowering plants, successful seed development requires that only two sperm are delivered to the embryo sac, where each must fertilize a female gamete （egg or central cell） to produce the embryo and endosperm. Therefore, polyspermy must be avoided, not only to prevent abnormalities in offspring, but to ensure double fertilization. It is not understood how each sperm fertilizes only one female gamete, nor has the existence of polyspermy barriers been directly tested in vivo. Here, we sought evidence for poly- spermy blocks in angiosperms using the polyspermic tetraspore （tes） mutant of Arabidopsis, which allows in-vivo challenge of egg and central cell with multiple male gametes. We show that tes mutant pollen tubes can transmit more than one sperm pair to an embryo sac, and that sperm from more than one pair can participate in fertilization. We detected endosperms but not embryos with ploidies that could only result from multiple fertilization. Our results therefore demonstrate an in-vivo polyspermy block on the egg, but not the central cell of a flowering plant.

关键词： Ovum Embryo Ploidies Endosperm Arabidopsis thaliana embryo sac Spermatozoa fertilizer application polyspermy flowering plant Eggs Fertilization

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

Robust Adaptive Model Tracking for Distributed Parameter Control of Linear Infinite-dimensional Systems in Hilbert Space

引用

IEEE/CAA j.urnal of Automatica Sinica 2014年第3期1卷 294-301页

作者： Mark j.Balas susan A.Frost the Embry-Riddle Aeronautical University the NASA Ames Research Center

This paper is focused on adaptively controlling a linear infinite-dimensional system to track a finite-dimensional reference *** a linear continuous-time infinite-dimensional plant on a Hilbert space with disturbances of known waveform but unknown amplitude and phase,we show that there exists a stabilizing direct model reference adaptive control law with the properties of certain disturbance rej.ction and *** plant is described by a closed,densely defined linear operator that generates a continuous semigroup of bounded operators on the Hilbert space of *** central result will show that all errors will converge to a prescribed neighborhood of zero in an infinitedimensional Hilbert *** result will not require the use of the standard Barbalat’s lemma which requires certain signals to be uniformly *** result is used to determine conditions under which a linear infinite-dimensional system can be directly adaptively controlled to follow a reference *** particular,we examine conditions for a set of ideal traj.ctories to exist for the tracking *** results are applied to adaptive control of general linear diffusion systems described by self-adj.int operators with compact resolvent.

关键词： Adaptation models Adaptive control Hilbert space Learning (artificial intelligence) Robustness Traj.ctory adaptive control algorithm adaptive theory distributed parameter system Distributed parameter systems Hilbert space traj.ctory Adaptation models reference model adaptive control Robustness Computer algorithms

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

根据甲状腺癌危险程度分层行放射性碘治疗和选择性靶向治疗

引用

中华核医学与分子影像杂志 2018年第5期38卷 371-377页

作者：董萍李林 Daniel A. Pryma susan j. Mandel 四川大学华西医院核医学科成都610041 Division of Nuclear Medicine and Clinical Molecular Imaging Department of Radiology Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania Division of Endocrinology Diabetes and Metabolism Department of Medicine Perelman School of Medicine University of PennsylvaniaPhiladelphia Pennsylvania

亲碘是分化型甲状腺癌的典型表现，可用放射性碘对该肿瘤进行有效治疗。在大多数分化型甲状腺癌患者中，常采用放射性碘来清除残留甲状腺组织（简称清甲），对于这类患者主张用最小有效剂量。辅助治疗可降低分化型甲状腺癌复发风险，但... 详细信息

亲碘是分化型甲状腺癌的典型表现，可用放射性碘对该肿瘤进行有效治疗。在大多数分化型甲状腺癌患者中，常采用放射性碘来清除残留甲状腺组织（简称清甲），对于这类患者主张用最小有效剂量。辅助治疗可降低分化型甲状腺癌复发风险，但相关患者的最佳纳入标准及具体治疗剂量尚不清楚。进展期分化型甲状腺癌患者能从最大放射性碘耐受剂量的治疗中获益。筛选适合清甲的患者及其治疗剂量是近期研究热点之一。近年来研发出一些用于治疗碘抵抗难治性分化型甲状腺癌的靶向药物，其中一种已通过美国食品与药品管理局（FDA）的批准，此外，多个临床试验正在评估单用靶向药物或靶向药物联合放射性碘治疗难治性分化型甲状腺癌的疗效。

关键词：甲状腺癌放射性碘治疗碘难治性疾病多激酶靶向治疗

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

TIC-Tox: A preliminary discussion on identifying the forcing agents of DBP-mediated toxicity of disinfected water

引用

j.urnal of Environmental Sciences 2017年第8期29卷 208-216页

作者： Michael j.Plewa Elizabeth D.Wagner susan D.Richardson Safe Global Water Institute and the Department of Crop Sciences University of Illinois at Urbana-Champaign Department of Chemistry and Biochemistry University of South Carolina

The disinfection of drinking water is a maj.r public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products（DBPs）. Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the *** a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes（THMs） and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the maj.r forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water.

关键词： DBPs CHO cell cytotoxicity Toxicity Additivity

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

Assessing the utility of dissolved organic matter photoreactivity as a predictor of in situ methylmercury concentration

引用

j.urnal of Environmental Sciences 2018年第6期30卷 160-168页

作者： Sara j.Klapstein susan E.Ziegler David A.Risk Nelson j.O'Driscoll Environmental Science Program Memorial University of Newfoundland Department of Earth Sciences St. Francis Xavier University Department of Earth and Environmental Science Acadia University

Methylmercury（MeHg） bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter（DOM） and other photoreactive ligands can convert MeHg into less toxic forms of mercury through photodemethylation. In this study, spectral changes and photoreactivity of DOM were measured to assess the potential to control photoreactions and predict in situ MeHg concentration. Water samples collected from a series of lakes in southwestern Nova Scotia in j.ne, August, and September were exposed to controlled ultraviolet-A（UV-A） radiation for up to 24 hr. Dissolved organic matter photoreactivity, measured as the loss of absorbance at 350 nm at constant UV-A irradiation, was positively dependent on the initial DOM concentration in lake waters（r^2=0.94）. This relationship was consistent over time with both DOM concentration and photoreactivity increasing from summer into fall across lakes. Lake in situ MeHg concentration was positively correlated with DOM concentration and likely catchment transport in j.ne（r = 0.77） but not the other sampling months. Despite a consistent seasonal variation in both DOM and Fe, and their respective correlations with MeHg, no discernable seasonal trend in MeHg was observed. However, a 3-year dataset from the 6 study lakes revealed a positive correlation between DOM concentration and both Fe（r = 0.91） and MeHg concentrations（r = 0.51） suggesting a more dominant landscape mobility control on *** DOM-MeHg relationships observed in these lakes highlights the need to examine DOM photoreactivity controls on MeHg transport and availability in natural waters particularly given future climate perturbations.

关键词： Methylmercury Dissolved organic carbon Photoreactions Kej.mkuj.k National Park Freshwater lakes

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

Tight j.nction disruption: Helicobacter pylori and dysregulation of the gastric mucosal barrier

引用

World j.urnal of Gastroenterology 2015年第40期21卷 11411-11427页

作者： Tyler j.Caron Kathleen E Scott j.mes G Fox susan j.Hagen Department of Surgery Beth Israel Deaconess Medical Center and Harvard Medical School Division of Comparative Medicine Massachusetts Institute of Technology

Long-term chronic infection with Helicobacter pylori(H. pylori) is a risk factor for gastric cancer development. In the multi-step process that leads to gastric cancer,tight j.nction dysfunction is thought to occur and serve as a risk factor by permitting the permeation of luminal contents across an otherwise tight mucosa. Mechanisms that regulate tight j.nction function and structure in the normal stomach,or dysfunction in the infected stomach,however,are largely unknown. Although conventional tight j.nction components are expressed in gastric epithelial cells,claudins regulate paracellular permeability and are likely the target of inflammation or H. pylori itself. There are 27 different claudin molecules,each with unique properties that render the mucosa an intact barrier that is permselective in a way that is consistent with cell physiology. Understanding the architecture of tight j.nctions in the normal stomach and then changes that occur during infection is important but challenging,because most of the reports that catalog claudin expression in gastric cancer pathogenesis are contradictory. Furthermore,the role of H. pylori virulence factors,such as cytotoxin-associated gene A and vacoulating cytotoxin,in regulating tight j.nction dysfunction during infection is inconsistent in different gastric cell lines and in vivo,likely because non-gastric epithelial cell cultures were initially used to unravel the details of their effects on the stomach. Hampering further study,as well,is the relative lack of cultured cell models that have tight j.nction claudins that are consistent with native tissues. This summary will review the current state of knowledge about gastric tight j.nctions,normally and in H. pylori infection,and make predictions about the consequences of claudin reorganization during H. pylori infection.

关键词： Helicobacter pylori Tight j.nction Claudins Parace

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

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：