检索结果-南通市图书馆

Crustal magnetization of mars: Terra meridiani and Terra Sirenum

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of modern Physics 2017年第8期8卷 1275-1293页

作者： Renee A. French donna m. jurdy Department of Earth and Planetary Sciences Northwestern University Evanston IL USA

We examine the crustal magnetization of Terra meridiani and Terra Sirenum, the region representing the strongest magnetization in the Southern Hemisphere, by downward continuing mapping level data (400 km altitude) from the mars Global Surveyor (mGS) magnetometer and Electron Reflectometer (mAG/ER). We find that the surface magnetization in both regions can be fit with a small number of sources, with the positive sources stronger than negative ones in both regions. The ratio of the strongest positive to strongest negative source for the regions matches within 2%. For both regions, the locations of strong sources are positioned at the outer rings of ancient impact features. We employ two approaches of source depth estimation. One method employs downward continuation of positive and negative sources from mapping level into the subsurface to extrapolate the depth to magnetization. With this approach, source depths generally range from 80 ±20 km in Terra meridiani and 65 ±25 km in Terra Sirenum. A graphical approach uses the contour map of surface magnetization to estimate depths ranging from 125 km for thick sources in Terra meridiani and from 82 km for thick sources in Terra Sirenum. These depths require a low (≤∼20 mW/m2) martian heat flux to permit magnetite, hematite, and/or pyrrhotite (although limited) as carriers through 100 km or more. The upcoming InSight mission will provide invaluable seismic constraints on both crustal and core structure, in addition to the first martian heat flow measurements that will constrain magnetization.

关键词： mars Crustal magnetization magnetization Depth InSight mission Geophysics

Thiopurine use associated with reduced B and natural killer cells in inflammatory bowel disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第18期23卷 3240-3251页

作者： James D Lord donna m Shows Translational Research Program Benaroya Research Institute Gastroenterology Division Virginia Mason Medical Center

To identify which blood and mucosal lymphocyte populations are specifically depleted by thiopurine use in *** thiopurines azathioprine and 6-mercaptopurine have been a mainstay of inflammatory bowel disease (IBD) therapy for decades, but their mechanism of action in vivo remains obscure. Although thiopurines are lymphotoxic at high doses, and have been reported to cause T cell apoptosis in vitro, their ability to control IBD at lower doses suggests that they may selectively deplete particular lymphocyte populations. Blood cells from 19 IBD patients on a thiopurine, 19 IBD patients not on a thiopurine, and 38 matched healthy control subjects were analyzed by multiple multi-color flow cytometry panels to quantify the immune cell subsets contained therein, both as a percent of cells, and as an absolute cell count. Similar analyses were performed on colon biopsies from 17 IBD patients on a thiopurine, 17 IBD patients not on a thiopurine, and 49 healthy screening colonoscopy *** blood counts revealed lower lymphocyte, but not monocyte or granulocyte, counts in IBD patients who were taking thiopurines at the time of sampling. This reduction was restricted to CD3-negative lymphocytes, wherein both natural killer (NK) and B cells were significantly reduced among thiopurine recipients. Among CD19+ B cells, the transitional B cells were particularly depleted, being nearly absent in both blood and colon biopsies of thiopurine recipients. No differences were associated with thiopurine use in CD8+ T cells, mucosa-associated invariant T (mAIT) cells, invariant natural killer T (iNKT) cells, gamma/delta T cells, Th1, Th17, regulatory T cells (Tregs) or naïve CD4+ T cells. However, patients with IBD had significantly more circulating FOXP3+, Helios+ Tregs and fewer iNKT and mAIT cells than healthy *** use is associated with reduced B and NK cell, but not T cell, subpopulations in the blood of IBD patients.

关键词： Thiopurine Azathioprine mercaptopurine Lymphocyte Natural killer cell Transitional B cell Inflammatory bowel disease

High energy femtosecond mid-infrared generation pumped by a two-color Ti:sapphire multipass amplifier

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第5期53卷 664-670页

作者： donna T. Strickland Department of Physics Guelph-Waterloo Physics Institute University of Waterloo 200 University Ave. W. Waterloo Ontario N2L 3G1 Canada

Intense mid-infrared was generated by direct frequency mixing two pulses from a dual-wavelength Ti:sapphire system. From a multipass amplifier we generated two tunable wavelength femtosecond pulses with a total energy of 15 mJ. Pulse energy of 1.6 μJ and 7.4 μJ of mid-infrared light is achieved with and without its multipass amplifier at 9-11 μm, with pulse duration of 500 fs.

关键词：兰宝石激光器红外激光远红外激光超速激光激光放大器

维普期刊数据库

A journey towards shared governance: status and prospects for collaborative management in the protected areas of Bangladesh

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2013年第3期24卷 599-605,602-605页

作者： A. Z. m. manzoor Rashid donna Craig Sharif Ahmed mukul Niaz Ahmed Khan Environmental Law School of Law University of Western SydneyAustralia Department of Forestry and Environmental Science Shahjalal University of Science and TechnologySylhet Bangladesh School of Agriculture and Food Sciences The University of QueenslandAustralia Department of Development Studies University of DhakaBangladesh

Establishment of Protected Areas （PAs）, in the face of rapid deforestation, forest degradation and climate change has been one of the key efforts in conservation of biodiversity worldwide in recent times. While Bangladesh has gained a degree of prominence in the world for its successful social forestry programs, the concept of collaborative pro- tected area management is rather new in the country, initiated in 2004 by the Bangladesh Forest Department in five PAs with financial assistance from USAID. Based on empirical evidence from three of the pilot PAs, we examined the achievements and associated challenges and prospects for co-management. Our fieldwork revealed a number of challenges faced by co-management institutions：（1） institutions were dominated by the elite group, overshadowing the voice of the community people; （2） mutual trust and collective performance are key to good governance but had not taken root in the PAs; （3） encroachment onto forest land and subsequent conversion to agriculture remained a serious problem that discouraged forest-dependent people from participating actively in co-management initiatives; （4） legal provisions （including acts, rules and policies） were not clearly and adequately disseminated and understood at the community level; （5） there remained a degree of ambiguity regarding the roles and responsibilities of forest department （FD） and co-management committees （CmC） in field operations, and this was not enhancing transparency and accountability of the overall initiative; （6） the long-term sustainability of co-management institutions was another major concern, as the local intuitional structure was still in a nascent stage, and provisioning of resources （either internally or externally） remained somewhat uncertain. We offer recommendations for improve- ment.

关键词： protected area co-management Nishorgo IPAC govern-ance

维普期刊数据库

Forest protected area governance in Bangladesh:a focus on the legal and policy framework

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2013年第4期11卷 345-351页

作者： A.Z.m.manzoor Rashid donna Craig michael I.Jeffery Niaz Ahmed Khan Department of Forestry and Environmental Science Shahjalal University of Science and Technology Environmental Law School of LawUniversity of Western Sydney Department of Development Studies University of Dhaka

In the context of renewed interest in collaboration in natural resource management,the collaborative governance approach has lately been introduced to the forest Protected Areas(PAs)in *** adoption of this co-management approach is seen as an attempt to influence the governance process towards a transformation from the conventional custodian system to a more participatory management *** of rights and responsibilities,effective participation,and equitable distribution of benefits amongst the key stakeholders working under a facilitative policy and legal framework are believed to address the broader goals of sustainable development Notwithstanding the resurgence of interest in governance of forest PAs through the co-management approach,academic research on the subject remains *** article attempts to review selected key information and milestones on the forest PAs governance with special reference to the major policies and legal *** a brief introductory section,this article focuses on the genesis and selected major features of the Forest PAs in the *** discussion then dwells on the policy and legal framework and provides a critique on its relevance for promoting community *** existing institutional arrangements for community engagement in protected area governance are also analyzed in light of the national and international commitment and policy obligations on the part of the *** salient observations and key findings of the study include the following:(1)despite its limitations,comanagement as concept and practice has gradually taken roots in Bangladesh;(2)the degree and level of active community participation remain low and limited,and there is also clear weakness in conscientizing and orientating the local community on the key legal and policy issues related to PA governance in the country;and(3)policy makers,practitioners,and other local stakeholders related to PA governance need to be orien

关键词： governance protected areas participation community decision-making organizations

维普期刊数据库

mechanisms for flowering plants to benefit arthropod natural enemies of insect pests： Prospects for enhanced use in agriculture

在线全文

学校读者我要写书评

暂无评论

Insect Science 2014年第1期21卷 1-12页

作者： Zhong-Xian Lu Ping-Yang Zhu Geoff m. Gurr Xu-Song Zheng donna m. Y. Read Kong-Luen Heong Ya-Jun Yang Hong-Xing Xu State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control Institute of Plant Protection and Microbiology Zhejiang Academy of Agricultural Sciences Hangzhou China EH Graham Centre for Agricultural Innovation Charles Stuff University Orange NSW Australia College of Chemistry and Life Science Zhejiang Normal University Jinhua Zhejiang Province China and Crop and Environmental Sciences Division International Rice Research Institute Los Banos Metro Manila Philippines

Reduction of noncrop habitats, intensive use of pesticides and high levels of disturbance associated with intensive crop production simplify the farming landscape and bring about a sharp decline of biodiversity. This, in turn, weakens the biological control ecosystem service provided by arthropod natural enemies. Strategic use of flowering plants to enhance plant biodiversity in a well-targeted manner can provide natural enemies with food sources and shelter to improve biological control and reduce dependence on chemical pesticides. This article reviews the nutritional value of various types of plant-derived food for natural enemies, possible adverse effects on pest management, and the practical application of flowering plants in orchards, vegetables and field crops, agricultural systems where most research has taken place. Prospects for more effective use of flowering plants to maximize biological control of insect pests in agroecosystem are good but depend up on selection of optimal plant species based on information on the ecological mechanisms by which natural enemies are selectively favored over pest species.

关键词： conservation biological control ecological engineering habitat nectar,nutrition pollen shelter

Polistes metricus queens exhibit personality variation and behavioral syndromes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2018年第1期64卷 45-52页

作者： Colin m. WRIGHT Trevor D. HYLAND Amanda S. IZZO donna R.mCDERmOTT Elizabeth A. TIBBETTS Jonathan N. PRUITT Department of Ecology Evolution and Marine Biology University of California at Santa Barbara Santa Barbara CA 93106 USA Department of Wildlife Fish and Conservation Biology University of California at Davis Davis CA 95616 USA Ecology and Evolutionary Biology University of Michigan Ann Arbor MI 48109-1048 USA

Consistent differences in behavior between individuals, otherwise known as animal personalities, have become a staple in behavioral ecology due to their ability to explain a wide range of phenomena. Social organisms are especially serviceable to animal personality techniques because they can be used to explore behavioral variation at both the individual and group level. Despite the suc- cess of personality research in social organisms generally, and social Hymenoptera in particular, social wasps （Vespidae） have received little to no attention in the personality literature. In the pre- sent study, we test Polistes metricus （Vespidae; Polistinae） paper wasp queens for the presence of repeatable variation in, and correlations （＂behavioral syndromes＂） between, several commonly used personality metrics： boldness, aggressiveness, exploration, and activity. Our results indicate that P. metricus queens exhibit personalities for all measured traits and correlations between differ- ent behavioral measures. Given that paper wasps have served as a model organism for a wide range of phenomena such as kin selection, dominance hierarchies, mate choice, facial recognition, social parasitism, and chemical recognition, we hope that our results will motivate researchers to explore whether, or to what degree, queen personality is important in their research programs.

关键词： behavioral syndromes personality social insects temperament wasps.

Advance Directives in the Context of Uncertain Prognosis for Residents of Nursing Homes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Nursing 2014年第4期4卷 321-329页

作者： Beryl E. Cable-Williams donna m. donna m. Wilson Norah Keating Department of Human Ecology University of Alberta Edmonton Canada Faculty of Nursing University of Alberta Edmonton Canada Trent/Fleming School of Nursing Trent University Peterborough Canada

This report documents the findings of a mixed-methods study focused on the advanced directives of 182 residents of three LTC facilities in southern Ontario, Canada. Although almost all had a completed advance directive within 3 months of death, most did not have a palliative designation or directive until a few days before they died. Each facility’s written Progress Notes revealed staff members usually sought additional confirmation of care preferences from residents’ substitute decision-makers within a few days of the death. It was thus common for advance directives to change from a more interventionist approach to the least interventionist approach near death. This change indicates that the meaning and significance of advance care planning and resulting advance directives must be considered in light of the processes and temporal factors involved in their completion and use within this distinct population. The relational nature of advance care planning and concern about ageism as a factor for withholding or withdrawing life support for LTC residents are considered as possible explanatory factors. These findings and their implications are described in relation to end-of-life care policies and practices in LTC facilities.

关键词： Advance Care Planning Advance Directives Palliative Care Nursing Homes

Daily and Weekly Standing Patterns When Using a Sit-Stand Desk in a College Class

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sports Science 2018年第2期6卷 65-75页

作者： Jeremy m. Frost donna J. Terbizan Department of Human Performance Minnesota State University-Mankato Mankato MN 56001 USA Department of Health Nutrition and Exercise Sciences North Dakota State University Fargo ND 58108 USA

Objective： Sit-stand desks have been designed to address high daily sitting in work and school environments. The purpose was to determine the daily pattern of use and overall likeability of sit-stand desk over the course of a semester. Participants： A total of 18 subjects （12 standing） completed the 11-week study （week 5-15 of the semester） from January-April, 2016. methods： Each student in the standing group was given a sit-stand desk to use as they desired. Results： Individual daily standing time ranged from 0-100% of daily attendance time and the daily group average ranged from 2.1-38.4%. Two-thirds of the standing bouts were ≤ 2 min. Perception questionnaire answers were positive for using the desk and their effect on students’ ability to work in class. Conclusions： The results indicate the sit-stand desks were utilized at low levels and for short durations for most participants, but perceptions of desk use remained positive.

关键词： Sit-stand desks adjustable-height desks classroom perceptions.