检索结果-南通市图书馆

Mercury concentrations in blood and feathers of nestling Bald Eagles in coastal and inland Virginia

Avian Research 2019年第1期10卷 36-42页

作者： David E.Kramar Bill Carstensen Steve Prisley Jim Campbell Department of Anthropology and Earth Science Minnesota State University Moorhead Department of Geography Virginia Tech national council for air and stream improvement

Background:Mercury(Hg) and methylmercury are widely considered significant issues for wildlife,and in particular,piscivorous birds due to their widespread availability and neurotoxic *** a substantial number of studies of Hg contamination of Bald Eagles(Haliaeetus leucocephalus) have been conducted throughout the east coast of the United States,little has been done that directly addresses Hg contamination in Bald Eagles in Virginia,particularly the inland ***:We collected blood and feather samples from nestling Bald Eagles in the coastal plain,piedmont,and western regions of Virginia in an effort to determine which areas of the state were more likely to contain populations showing evidence of Hg *** analyzed the samples for total Hg using a Milestone ***:Samples collected from individuals located in the coastal region exhibited low concentrations of Hg compared to those further inland located on freshwater rivers and *** collected from the inland population exhibited levels in some areas that are approaching what may be considered to be sub-lethal to avian health(blood:mean 0.324 mg/kg,SE = 0.13,range = 0.06-0.97 mg/kg;feather:mean = 8.433 mg/kg,SE = 0.3,range = 3.811-21.14 mg/kg).Conclusions:Even after accounting for known point-sources of Hg,the inland eagle population in Virginia is susceptible to concentrations of Hg that are significantly higher than their coastal ***,several locations besides those currently known to be impacted by point-sources are exhibiting concentrations that are approaching a sub-lethal level.

关键词： Bald Eagle Haliaeetus leucocephalus Mercury Methyl-mercury Virginia

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

Model-Based Forecasts of North American Forest Growth: A Review

引用

American Journal of Climate Change 2018年第4期7卷 519-547页

作者： Craig Loehle national council for air and stream improvement Inc. Naperville USA

In the context of climate change, planning for forest management goals becomes more complicated. Possible changes in precipitation, temperature, and CO2 can affect tree growth substantially and potential effects differ by species and region. However, integration of potential forest growth responses to these factors can be achieved using models. Because of the need to understand the range of forest growth forecasts and the strengths and limitations of different modeling approaches, I summarized results from 25 studies of forecasted forest responses over coming decades. Some models used statistical relationships between tree rings and climate to forecast growth responses to future climate, some simulated net photosynthesis of a standard forest canopy, and many used tree or stand growth models at various levels of mechanistic detail. In general, models that included CO2 responses predicted enhanced forest growth by 2100 across most of the commercial timberland areas of the US and Canada. For modest warming, most models showed growth enhancement in most regions. For hotter scenarios, many models and regions showed even more growth enhancement, but some regions such as the Southwest, mountain West, and southwestern Canada were predicted to experience drought stress and increased fire incidence, although projections in these regions were variable. Young stands, angiosperms, and early-successional species were predicted to exhibit the most positive responses. As a result, commercial harvest ages might be accelerated by several years, depending on species. Some simulations for the Midwest and Northeast US predicted a doubling or more of net primary productivity although other studies show a lesser response. Model runs that did not include mechanisms of CO2 fertilization showed positive growth responses in only limited cases and generally showed growth declines. There also was some evidence indicating the potential spread of forest into woodland at shrub or prairie ecotones.

关键词： Carbon Dioxide Fertilization Climate Change Fire Forest Response Growth Model 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

Evaluation of the Survivability of SARS-CoV-2 on Cardboard and Plastic Surfaces and the Transferability of Virus from Surface to Skin

引用

Occupational Diseases and Environmental Medicine 2021年第2期9卷 63-73页

作者： Giffe T. Johnson Craig Loehle Sifang S. Zhou Cory Chiossone James Palumbo Paul Wiegand national council for air and stream improvement (NCASI) Cary USA Microbac Laboratories Inc. Sterling USA

Objective: To 1) characterize the decay curve of infective SARS-CoV-2 over time on the surface of cardboard packaging and plastic mailer packaging;2) characterize the transferability over time of virus-inoculated cardboard packaging and plastic mailer packaging to skin. Methods: We inoculated samples of plastic and cardboard packaging with a titer of SARS-CoV-2 > 106 TCID50/ mL to evaluate the survivability and transferability to the skin (pig skin) over time. A cell culture-based infectivity assay (TCID50) was used to determine viral titers. Regression analysis was used to characterize decay curves. Results: The time that SARS-CoV-2 remained transferable to skin was reduced on both packaging substrates compared to the total time of survivability, though cardboard demonstrated a substantially larger reduction. Virus inoculated plastic substrates continued to transfer the virus to the skin after 7 hours of holding time and regression analysis predicts this transferability would remain detectable up to 9.5 hours of holding time. Inoculated cardboard substrates demonstrated detectable transfer at 15 minutes of holding time, but no viable virus could be detected on the skin after 30 minutes of holding time. Conclusions: The type of material used as a packaging substrate substantially modifies the potential for SARS-CoV-2 fomite transmission. The use of materials that limit fomite transmission from packaging should be considered among strategies to reduce the transmission of SARS-CoV-2. Future research should investigate the generalizability of these findings for other viral pathogens that potentially transmit via fomite.

关键词： SARS-CoV-2 Fomite Cardboard Plastic Viral Transmission to Skin

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

Tribenuron-Methyl Induces Male Sterility through Anther-Specific Inhibition of Acetolactate Synthase Leading to Autophagic Cell Death

引用

Molecular Plant 2015年第12期8卷 1710-1724页

作者： Lun Zhao Xue Jing Li Chen Yingjun Liu Yanan Su Tingting Liu Changbin Gao Bin Yi Jing Wen Chaozhi Ma Jinxing Tu Jitao Zou Tingdong Fu Jinxiong Shen national Key Laboratory of Crop Genetic improvement National Center of Rapeseed Improvement Huazhong Agricultural University Wuhan 430070 China national Research council Canada Saskatoon Saskatchewan S7N 0W9 Canada

Tribenuron-methyl （TM） is a powerful sulfonylurea herbicide that inhibits branched-chain amino acid （BCAA） biosynthesis by targeting the catalytic subunit （CSR1） of acetolactate synthase （ALS）. Selective in- duction of male sterility by foliar spraying of TM at low doses has been widely used for hybrid seed produc- tion in rapeseed （Brassica napus）; however, the underlying mechanism remains unknown. Here, we report greater TM accumulation and subsequent stronger ALS inhibition and BCAA starvation in anthers than in leaves and stems after TM application. Constitutive or anther-specific expression of csrl-lD （a CSR1 mutant） eliminated anther-selective ALS inhibition and reversed the TM-induced male sterile phenotype in both rapeseed and Arabidopsis. The results of TM daub-stem experiments, combined with the observations of little TM accumulation in anthers and reversion of TM-induced male sterility by targeted expression of the TM metabolism gene Bel in either the mesophyll or phloem, suggested that foliar-sprayed TM was polar-transported to anthers mainly through the mesophyll and phloem. Microscopy and immunoblotting revealed that autophagy, a bulk degradation process induced during cell death, was elevated in TM-induced male sterile anthers and by anther-specific knockdown of ALS. Moreover, TM-induced pollen abortion was significantly inhibited by the autophagy inhibitor 3-MA. These data suggested that TM was polar-transported to anthers, resulting in BCAA starvation via anther-specific ALS inhibition and, ulti- mately, autophagic cell death in anthers.

关键词： male sterility chemical hybridizing agent acetolactate synthase amino acid starvation autophagy,Brassica napus

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

Approximating Geographical Queries

引用

Journal of Computer Science & Technology 2009年第6期24卷 1109-1124页

作者： Arianna D’Ulizia Fernando Ferri Anna Formica Patrizia Grifoni Institute of Research on Population and Social Policies National Research Council Institute for System Analysis and Computer Science National Research CouncilRome Italy

This article proposes a graph-theoretic methodology for query approximation in Geographic Information Systems, enabling the relaxation of three kinds of query constraints： topological, semantic and structural. An approximate query is associated with a value corresponding to the degree of similarity with the original query. Such a value is computed for topological constraints on the basis of the topological distance between configurations, for semantic constraints using the information content approach, and for structural constraints revisiting the maximum weighted matching problem in bipartite graphs. Finally, the high correlation of our proposal with human judgment is demonstrated by an experiment.

关键词： query language spatial database GIS (Geographic Information System) query formulation

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

Development of carbon composite iron ore micropellets by using the microfines of iron ore and carbon-bearing materials in iron making

引用

International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 132-140页

作者： Jagannath Pal Satadal Ghorai Avimanyu Das national Metallurgical Laboratory Council of Scientific and Industrial Research

Iron ore microfines and concentrate have very limited uses in sintering processes. They are used in pelletization; however, this process is cost intensive. Furthermore, the microfines of non-coking coal and other carbon-bearing materials, e.g., blast-furnace flue dust （BFD） and coke frees, are not used extensively in the metallurgical industry because of operational difficu]ties and handling problems. In the present work, to utilize these microfines, coal composite iron oxide micropellets （2-6 mm in size） were produced through an innovative technique in which lime and molasses were used as binding materials in the micropellets. The micropellets were subsequently treated with CO2 or the industrial waste gas to induce the chemical bond formation. The results show that, at a very high carbon level of 22wt% （38wt% coal）, the cold crushing strength and abrasion index of the micropellets are 2.5-3 kg/cm2 and 5wt%-9wt%, respectively; these values indicate that the pellets are suitable for cold handling. The developed micropellets have strong potential as a heat source in smelting reduction in iron making and sintering to reduce coke breeze. The micropellets produced with BFD and coke fines （8wt%-12wt%） were used in iron ore sin- tering and were observed to reduce the coke breeze consumption by 3%-4%. The quality of the produced sinter was at par with that of the conventional blast-furnace sinter.

关键词： ironmaking microfines non-coking coal iron ore concentrates micropellets pelletizing, waste utilization

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

Remediation of a Mercury-Contaminated Industrial Soil Using Bioavailable Contaminant Stripping

引用

Pedosphere 2013年第1期23卷 104-110页

作者： F.PEDRON G.PETRUZZELLI M.BARBAFIERI E.TASSI national Research council Institute of Ecosystem Studies

The method to remove bioavailable amounts of heavy metals from a contaminated soil by using plants is defined as bioavailable contaminant stripping （BCS） and could safely be applied if the soil＇s long-term ability to replenish the bioavuilable pool is known. The aim of this study was to evaluate the ability of three common plant species selected, Brassica juncea, Poa annua, and Helianthus annus, to remove bioavailable amounts of mercury （Hg） from a contaminated industrial soil containing 15.1 mg kg-1 Hg. Trials were carried out under greenhouse conditions using pots （mesocosms）. According to the precautionary principle, we modified the BCS remediation approach by adding a new step, in which mercury bioavailability was increased by the addition of a strong mobilizing agent, ammonium thiosulphate, （NH4）28203, to obtain an estimate of the likely long-term bioavailable Hg pool. The modified BCS remediation approach was called enhanced bioavailable contaminant stripping （EBCS）. After one growth cycle, nearly all the bioavailable mercury （95.7%） was removed and the metal remaining in the soil was considered inert since it was neither extractable by （NH4）2S2O3 nor taken up by plants during a second growth cycle. The results demonstrated that EBCS appeared promising since it removed the most dangerous metal forms while substantially shortening the cleanup time.

关键词： heavy metal mercury bioavailability mobilizing agent plant species remediation approach

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

Potential impacts of climate change on Welwitschia mirabilis populations in the Namib Desert,southern Africa

引用

Journal of Arid Land 2018年第5期10卷 663-672页

作者： Pierluigi BOMBI Institute of Agro-environmental and Forest Biology National Research Council of Italy LifeWatch-ITA Mediterranean Thematic Center National Research Council of Italy

Climate change is threatening natural ecosystems in the Earth, and arid regions of southern Africa are particularly exposed to further drying. Welwitschia mirabilis Hook. （Welwitschiaceae） is an unusual gymnosperm tree that is recognized as an icon of the Namib Desert, southern Africa. Many aspects of its biology were investigated in the past, with a special emphasis for its physiology and adaptations, but nothing is known about its potential sensitivity to current climate changes. In this study, we adopted an approach based on distribution data for W. mirabilis and ecological niche models for clarifying the species-climate interactions and for predicting the potential impacts of climate change on W. mirabilis populations in three well-separated sub-ranges （northern, southern and central） in northwestern Namibia, southern Africa. We evidenced that the populations occurring in the northern sub-range have peculiar climatic exigencies compared with those in the central and southern sub-ranges and are particularly exposed to the impact of climate change, which will consist of a substantial increase in temperature across the region. These impacts could be represented by demographic changes that should be detected and monitored detailedly to plan efficient measures for managing populations of this important species on the long-term scale.

关键词： global warming range fragmentation climatic suitability Welwitschia mirabilis ecological niche model Namib Desert

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

Forest mapping:a comparison between hyperspectral and multispectral images and technologies

引用

Journal of Forestry Research 2018年第5期29卷 1395-1405页

作者： Mohamad M.Awad Remote Sensing Center National Council for Scientific Research

Mapping forests is an important process in managing natural *** present,due to spectral resolution limitations,multispectral images do not give a complete separation between different forest *** contrast,advances in remote sensing technologies have provided hyperspectral tools and images as a solution for the determination of *** this study,spectral signatures for stone pine（Pinus pinea L.） forests were collected using an advanced spectroradiometer ＂ASD FieldSpec 4 Hi-Res＂ with an accuracy of 1 *** spectral signatures are used to compare between different multispectral and hyperspectral satellite *** comparison is based on processing satellite images： hyperspectral Hyperion,hyperspectral CHRIS-Proba,Advanced Land Imager（ALI）,and Landsat *** and classification methods for hyperspectral and multispectral images are investigated and *** addition,a well-known hyperspectral image classification algorithm,spectral angle mapper（SAM）,has been improved to perform the classification process efficiently based on collected spectral *** results show that the modified SAM is 9% more accurate than the conventional *** addition,experiments indicate that the CHRIS-Proba image is more accurate than Landsat 8（overall accuracy 82%,precision 93%,and Kappa coefficient 0.43 compared to 60,67%,and 0.035,respectively）.Similarly,Hyperion is better than ALI in mapping stone pine（overall accuracy 92%,precision 97%,and Kappa coefficient 0.74 compared to 52,56%,and -0.032,respectively）.

关键词： Classification Economy Hyperspectral Multispectral Spectral signatures Stone pine

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

Application of a Robust Model Reference Adaptive Control Algorithm to a Nonlinear Automotive Actuator

引用

International Journal of Automation and computing 2014年第4期11卷 377-391页

作者： Alessandro di Gaeta Umberto Montanaro Istituto Motori National Research Council Naples Italy

Model reference adaptive control is a viable control method to impose the demanded dynamics on plants whose parameters are affected by large uncertainty. In this paper, we show by means of experiments that robust adaptive methods can effectively face nonlinearities that are common to many automotive electromechanical devices. We consider here, as a representative case study, the control of a strongly nonlinear automotive actuator. The experimental results confirm the effectiveness of the method to cope with unmodeled nonlinear terms and unknown parameters. In addition, the engineering performance indexes computed on experimental data clearly show that the robust adaptive strategy provides better performance compared with those given by a classical model-based control solution with fixed gains.

关键词： Model reference adaptive control robust adaptive control nonlinear systems automotive control electronic throttle body electromechanical actuators

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：