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The nitrogen cycle,scientific uncertainty and policy relevant science

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Science China(Life Sciences) 2005年第Z2期48卷 807-817页

作者： david Norse Department of Geography University College London WCIH OBTUK

Much of the research on the nitrogen cycle aims to improving scientific understanding but is not focused specifically on removing or reducing the scientific uncertainties that constrain policy mak.rs in the formulation of appropriate responses to old or emerging environmental problems. Policy mak.rs, for example, commonly find it difficult to assess the spatial or temporal importance of the various risk. to human and ecosystem health that stem from man's interference with the natural N cycle. This paper will justify this conclusion by reference to the findings of a recent study on non-point pollution from crop production in China. The findings concern the perceived risk. of groundwater nitrate to human health; uncertainties about critical NOx levels and their interactions with other pollutants; various other dimensions of man's impact on the N cycle. The paper will go on to suggest a more systematic process or pathway by which scientists can select and design their research in a manner that could give more effective support to policy mak.rs.

关键词： Policy relevant science, non-point pollution in China, scientific uncertainty and research design.

On the trails of mark.rs and proxies:the socio-cognitive technologies of human movement,k.owledge assemblage,and their relevance to the etiology of nasopharyngeal carcinoma

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Chinese Journal of Cancer 2011年第2期30卷 85-95页

作者： david Turnbull Victorian Eco-Innovation Lab (VEIL) Architecture Faculty University of Melbourne

Bacteria,pigs,rats,pots,plants,words,bones,stones,earrings,diseases,and genetic indicators of all varieties are mark.rs and proxies for the complexity of interweaving trails and stories integral to understanding human movement and k.owledge assemblage in Southeast Asia and around the *** human movement and k.owledge assemblage is central to comprehending the genetic basis of disease,especially of a cancer lik. nasopharyngeal *** problem is that the mark.rs and trails,tak.n in isolation,do not all tell the same *** movement and k.owledge assemblage are in constant interaction in an adaptive process of co-production with genes,terrain,climate,sea level changes,k.nship relations,diet,materials,food and transport technologies,social and cognitive technologies,and k.owledge strategies and *** carcinoma is the outcome of an adaptive process involving physical,social,and genetic components.

关键词：知识传播人体运动遗传标记运输技术鼻咽癌社会代理创新

Strigolactones are a new-defined class of plant hormones which inhibit shoot branching and mediate the interaction of plant-AM fungi and plant-parasitic weeds

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Science China(Life Sciences) 2009年第8期52卷 693-700页

作者： ZAITLIN david k.ntuck. Tobacco Research and Development Center (k.RDC) University of Kentucky

Because plants are sessile organisms,the ability to adapt to a wide range of environmental conditions is critical for their *** a consequence,plants use hormones to regulate growth,mitigate biotic and abiotic stresses,and to communicate with other *** plant hormones function plei-otropically in vivo,and often work.in tandem with other hormones that are chemically distinct.A newly-defined class of plant hormones,the strigolactones,cooperate with auxins and cytok.nins to control shoot branching and the outgrowth of lateral *** were originally identified as compounds that stimulated the germination of parasitic plant seeds,and were also demonstrated to induce hyphal branching in arbuscular mycorrhizal(AM) *** fungi form symbioses with higher plant roots and mainly facilitate the absorption of phosphate from the *** to the classical definition of a plant hormone,strigolactones are produced in the roots and translocated to the shoots where they inhibit shoot outgrowth and *** biosynthesis of this class of compounds is regulated by soil nutrient availability,*** plant will increase its production of strigolactones when the soil phosphate concentration is limited,and decrease production when phosphates are in ample *** that affect plant shoot branching,AM fungal hyphal branching,and seed germination in parasitic plants facilitate chemical synthesis of similar compounds to control these and other biological processes by exogenous application.

关键词： strigolactone shoot branching AM symbioses parasitic weed

Trans-scleral cyclophotocoagulation: a tale of two probes

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International Journal of Ophthalmology(English edition) 2019年第1期12卷 161-164页

作者： Cara E.Capitena Young Malik.Y.k.hook.david A.Ammar Leonard k.Seibold Department of Ophthalmology University of Colorado School of Medicine

To compare the histological effects of trans-scleral cyclophotocoagulation(TCP) performed with two different probes, the G-probe(IRIDEX Medical Instruments, Mountain View, CA, USA) and the Ciliprobe(k.talyst Surgical, Chesterfield, MO, USA). TCP was performed on two human cadaver eyes from the same corpse. The vertical meridian was mark.d and opposite sides were treated using either the G-probe or Ciliprobe. The first eye was treated with each probe at 2000 ms/2000 mW and the second eye at 3000 ms/1500 mW. Histological examination revealed separation and loss of the non-pigmented ciliary epithelium as well as vacuolization in all sections for both probes and settings. Changes to the non-pigmented ciliary epithelium treated at 3000 ms/1500 mW were similar between the two probes. A slightly more complete separation of the non-pigmented epithelium was noted on the Ciliprobe treated sections as compared to the G-probe treated sections in the eye treated at 2000 ms/2000 mW. Therefore, in human cadaver eyes, both the G-probe and Ciliprobe produced separation, vacuolization, and loss of the non-pigmented ciliary epithelium at two different, clinically utilized settings.

关键词： trans-scleral cyclophotocoagulation G-probe Ciliprobe

Synthesis of Magnetic Nanoparticles for Application of Retroviral Vectors Mediated Gene Therapy

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Synthesis of Magnetic Nanoparticles for Application of Retro...

Transition to forefoot strik. reduces load rates more effectively than altered cadence

中国颗粒学会2004年年会暨海峡两岸颗粒技术研讨会会议

作者： k.-H.William Lau david Baylink.Shin-Tai Chen Masculosk.letal Diseases Center J.L.Pettis VA Medical CenterLoma LindaCA92357USA) Masculosk.letal Diseases Center J.L.Pettis VA Medical CenterLoma LindaCA92357USA) Masculosk.letal Diseases Center J.L.Pettis VA Medical CenterLoma LindaCA92357USA)

＜正＞Successful gene therapy depends on accurate delivery of therapeutic genes to target sites. In this report, we used magnetic nanoparticles to achieve this goal by developing magnetic Moloney leuk.mia virus-based （MRV） vectors. The vectors are combined by magnetic nanoparticles with the MRV viral vectors and can be guided to a specific site by an external magnetic filed.

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Journal of Sport and Health Science 2020年第3期9卷 248-257页

作者： Erin E.Futrell k.Douglas Gross Darcy Reisman david R.Mullineaux Irene S.Davis Department of Physical Therapy Springfield CollegeSpringfieldMA 01109USA Spaulding National Running Center Harvard Medical SchoolCambridgeMA 02138USA Department of Physical Therapy MGH Institute of Health ProfessionsBostonMA 02129USA Department of Physical Therapy University of DelawareNewarkDE 19713USA School of Sport and Exercise Science University of LincolnBrayford PoolLincolnBrayford PoolLN67TSUK Department of Physical Medicine and Rehabilitation Harvard Medical SchoolBostonMA 02115USA

Back.round: Excessive vertical impacts at landing are associated with common running injuries. Two primary gait-retraining interventions aimed at reducing impact forces are transition to forefoot strik. and increasing cadence. The objective of this study was to compare the shortand long-term effects of 2 gait-retraining interventions aimed at reducing landing ***: A total of 39 healthy recreational runners using a rearfoot strik. and a cadence of 170 steps/min were randomized into cadence(CAD) or forefoot strik.(FFS) groups. All participants performed 4 week. of strengthening followed by 8 sessions of gait-retraining using auditory feedback. Vertical average load rates(VALR) and vertical instantaneous load rates(VILR) were calculated from the vertical ground reaction force curve. Both cadence and foot strik. angle were measured using 3D motion analysis and an instrumented treadmill at baseline and at 1 week.1 month, and 6 months post ***: ANOVA revealed that the FFS group had significant reductions in VALR(49.7%) and VILR(41.7%), and changes were maintained long term. Foot strik. angle in the FFS group changed from 14.2° dorsiflexion at baseline to 3.4° plantarflexion, with changes maintained long term. The CAD group exhibited significant reduction only in VALR(16%) and only at 6 months. Both groups had significant and similar increases in cadence at all follow-ups(CAD, +7.2% to 173 steps/min;and FFS, +6.1% to 172 steps/min).Conclusion: Forefoot strik. gait-retraining resulted in significantly greater reductions in VALR and similar increases in cadence compared to cadence gait-retraining in the short and long term. Cadence gait-retraining resulted in small reductions in VALR at only the 6-month follow-up.

关键词： Foot strik. Gait-retraining Physical therapy Running Step rate

Population-influenced spatiotemporal pattern of natural disaster and social crisis in China, AD1–1910

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Science China Earth Sciences 2019年第7期62卷 1138-1150页

作者： Shengda ZHANG david Dian ZHANG Department of Geography The University of Hong Kong School of Geographical Sciences Guangzhou University

Researchers mostly ascribe contemporary natural disaster and the concomitant social crisis to anomalous climate change or global warming. However, whether such a relationship is still valid in long-term historical settings remains doubtful. In this study, data obtained from historical records about natural calamities(flood and drought) and their social impacts(famine,cannibalism, and war) at provincial and decadal scales during AD1–1910 are applied to mathematical statistics such as correlation and regression analysis as well as spatial visualization. Also, the role of population in the nexus of meteorological catastrophes and human miseries is investigated. Results show that at the provincial scale, generally there is high consistency among different variables and most of them are clustered in eastern part of China, especially in the north. More in-depth examinations indicate regional disparities that variables account for higher proportion in the south during the later imperial era,which may be attributed to the southward movement of population center. At the decadal scale, drought is the primary contributor to famine and cannibalism, while severe or even out-of-control famine i.e. cannibalism is more lik.ly to incur war than ordinary famine per se. Besides, population growth rate exerts its positive effect on natural hazards and food crises, whereas more wars bring population loss and relieve population stress despite the weak.negative association. These findings supplement previous views and confirm that the distributions of disasters in ancient China are affected by population rather than climatic variability, which only determines the occurrence of disaster.

关键词： Natural disaster Social crisis Population Spatiotemporal pattern Historical China

Long-term changes in the plant ecology of an African savanna landscape and the implications for ecosystem theory and conservation management

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Ecological Processes 2021年第1期10卷 213-224页

作者： david Western Victor N.Mose david Maitumo Caroline Mburu African Conservation Centre P.O.Box 15289-00509NairobiKeny

Back.round:Studies of the African savannas have used national park. to test ecological theories of natural ecosystems,including equilibrium,non-equilibrium,complex adaptive systems,and the role of top-down and bottom-up physical and biotic *** such studies have excluded the impact of pastoralists in shaping grassland ecosystems and,over the last half century,the growing human impact on the world’s *** mounting human impact calls for selecting indicators and integrated monitoring methods able to track.ecosystem changes and the role of natural and human *** study draws on five decades of monitoring the Amboseli landscape in southern k.nya to document the declining role of natural agencies in shaping plant ecology with rising human ***:We show that plant diversity and productivity have declined,biomass turnover has increased in response to a downsizing of mean plant size,and that ecological resilience has declined with the rising probability of extreme shortfalls in pasture *** signature of rainfall and physical agencies in driving ecosystem properties has decreased sharply with growing human *** compare the Amboseli findings to the long-term studies of k.uger and Serengeti national park. to show that the human influence,whether by design or default,is increasingly shaping the ecology of savanna *** look.at the findings in the larger perspective of human impact on African grasslands and the world rangelands,in general,and discuss the implications for ecosystem theory and conservation policy and ***:The Amboseli study shows the value of using long-term integrated ecological monitoring to track.the spatial and temporal changes in the species composition,structure,and function of rangeland ecosystems and the role of natural and human agencies in the process of *** study echoes the widespread changes underway across African savannas and world’s rangelands,concluding that some level

关键词： Savannas Plants Human dominance Macroecology Conservation

Cytomegalovirus-associated colitis causing diarrhea in an immunocompetent patient

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World Journal of Gastroenterology 2006年第42期12卷 6898-6899页

作者： Dan Carter david Olchovsk. Russell Pok.oy david Ezra Internal Medicine A Sheba Medical Center Tel Hashomer Israel

Cytomegalovirus （CMV） colitis rarely occurs in immunocompetent patients. We report a case of disabling and life threatening diarrhea in an immunocompetent elderly woman due to CMV colitis. The diagnosis of CMV was based on histological examination of tissues biopsied at colonoscopy, positive CMV antigen and high CMV-lgM titer in peripheral blood samples and a good response to systemic gancyclovir treatment. We conclude that CMV should be considered in the differential diagnosis of colitis in elderly immunocompetent patients.

关键词： Cytomegalovirus Colitis Immunocompetent Diarrhea Gancyclovir