检索结果-南通市图书馆

Sap flow for beech(Fagus sylvatica L.)in a natural and a managed forest—effect of spatial heterogeneity

维普期刊数据库博看期刊

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

Journal of Plant Ecology 2011年第1期4卷 23-35页

作者： Lise dalsgaard Teis Nørgaard Mikkelsen Annemarie Bastrup-Birk Forest and Landscape Faculty of Life SciencesUniversity of CopenhagenRolighedsvej 231958 Frederiksberg CDenmark RisøNational Laboratory for Sustainable Energy Technical University of DenmarkFrederiksborgvej 399P.O.Box 494000 RoskildeDenmark

Aims Beech(Fagus sylvatica L.)is an important species in natural and managed forests in *** drought-sensitive species dominates even-aged stands as well more natural stands composed of a mixture of tree species,age and size *** study evaluates the extent that heterogeneity in spacing and tree diameter affect the seasonal availability and use of *** Two stands were evaluated:(i)a heterogeneous forest remnant(NAT)with trees up to;300 years old,a mean top height of 28.4 m and a total of 733 stems ha1with stem diameters averaging 18 cm and(ii)an even-aged 80-year old stand(MAN),with a height of 25 m,and a total of 283 stems ha1 with diameters averaging 38 *** sap flow,Js(g m2 s1),was continuously measured in 12(MAN)and 13(NAT)trees using 20-mm long heat dissipation *** tree measures of sap flow were correlated using non-linear statistical methods with air vapour pressure deficit(D,hPa)and global radiation(Rg,J m2 day1),along with constraints imposed by reductions in soil water content(SWC).SWC was measured as volumetric%using time domain *** Findings The daily integrated Js(Js-sum)for trees growing in the evenly spaced MAN stand and trees in canopy and closed forest positions in NAT stand decreased as the availability of soil moisture was *** the heterogeneous NAT stand,SWC in a recently formed canopy gap remained high throughout the vegetation *** on regression models,the predicted relative decrease in Js-sum for dry relative to moist soil water conditions in the closed forest(at mean daily D=10 hPa)was 7–11%for trees near the gap and 39–42%for trees in the closed *** MAN,the reduction in Js-sum was 29%in dry relative to moist ***-sum in the outer 20 mm of the xylem in NAT was lower than that in MAN and the rate of decline in Js with xylem depth was less in NAT than in *** MAN,Js-sum in deep and outer xylem was negatively affected at low soil moisture availability

关键词： canopy gap canopy structure tree size tree water use

Seismic study of solar convection and overshooting: results of nonlocal convection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2013年第9期13卷 1127-1140页

作者： Chun-Guang Zhang Li-Cai Deng Da-Run Xiong Jrgen Christensen-dalsgaard Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Purple Mountain Observatory Chinese Academy of Sciences Stellar Astrophysics Centre Department of Physics and Astronomy Aarhus University

Local mixing-length theory is incapable of describing nonlocal phenom- ena in stellar convection, such as overshooting. Therefore standard solar models con- structed with local mixing-length theory significantly deviate from the Sun at the boundaries of the convection zone, where convection becomes less efficient and nonlo- cal effects are important. The differences between observed and computed frequencies mainly come from the region near the surface, while the localized difference in sound speed is just below the convective envelope. We compute a solar envelope model using Xiong＇s nonlocal convection theory, and carry out helioseismic analysis. The nonlocal model has a smooth transition at the base of the convection zone, as revealed by helio- seismology. It reproduces solar frequencies more accurately, and reduces the localized difference in sound speed between the Sun and standard solar models.

关键词： convection -- Sun: interior -- Sun: helioseismology

兆瓦级风力机结构系统可靠性分析的样本分数阶矩最大熵方法

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

太阳能学报 2022年第7期43卷 293-301页

作者：黄德胜张旭方 Sørensen John dalsgaard 东北大学机械工程与自动化学院沈阳110819 丹麦奥尔堡大学土木工程学院奥尔堡DK-9220

以兆瓦级风力机塔架和叶片极限载荷的概率外推模型为基础,结合载荷动态响应峰值的独立同分布假设和三参数威布尔模型,外推获取了正常湍流和极端湍流强度条件下风力机关键部件长期服役载荷概率分布;进一步通过无量纲极值统计量定义系统... 详细信息

以兆瓦级风力机塔架和叶片极限载荷的概率外推模型为基础,结合载荷动态响应峰值的独立同分布假设和三参数威布尔模型,外推获取了正常湍流和极端湍流强度条件下风力机关键部件长期服役载荷概率分布;进一步通过无量纲极值统计量定义系统失效的结构可靠性状态函数,结合样本分数阶矩和最大熵理论提出兆瓦级风力机关键部件结构可靠性分析的数值方法,对比湍流模型对兆瓦级风力机关键部件结构失效概率的影响。计算结果表明:样本分数阶矩最大熵方法能有效重构结构可靠性状态函数的概率分布;基于无量纲极值统计量的系统可靠性建模方法能有效表征风力机关键部件耦合相关失效问题,结合该文方法可获得系统失效概率的准确预测结果;湍流模型对风力机结构失效概率影响较大,难以预先判定何种模型将得到结构失效概率的保守预估结果,需结合IEC 61400-1标准中的设计载荷工况细致分析后才能确定。

关键词：风力机最大熵方法概率分布湍流模型可靠性分析

Nuclear Stopping: Paving the way from RHIC to LHC

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

Nuclear Stopping: Paving the way from RHIC to LHC

Probabilistic modeling for an integrated temporary acquired immunity with norovirus epidemiological data

The 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions

作者： H. H. dalsgaard for the BRAHMS collaboration Niels Bohr Institute The University of Copenhagen Blegdamsvej 17Copenhagen 2100Denmark

Using data taken with the BRAHMS experiment at RHIC the rapidity and energy loss in Au+Au collisions at S =62.4GeV has been measured. For the first time at RHIC energies it is possible to resolve almost the entire baryon rapidity density. dNB-(B|-)(y)/*** results show that the trend of the rapidity loss as a function of ybeam, defined as :

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2019年第1期4卷 99-114页

作者： Emmanuel de-Graft Johnson Owusu-Ansah Benedict Barnes Robert Abaidoo Hald Tine Anders dalsgaard Anders Permin Torben Wilde Schou Department of Mathematics Faculty of Physical and Computational ScienceCollege of ScienceKwame Nkrumah University of Science and TechnologyKumasiGhana Laboratory of Integrated Statistical Applications(LISA) Faculty of Physical and Computational SciencesCollege of ScienceKwame Nkrumah University of Science and TechnologyKumasiGhana Regional Water and Environmental Sanitation Center-Kumasi College of EngineeringKwame Nkrumah University of Science and TechnologyKumasiGhana Department of Theoretical and Applied Biology Faculty of Bio ScienceCollege of ScienceKwame Nkrumah University of Science and TechnologyKumasiGhana Research Group of Genomic Epidemiology National Food InstituteTechnical University of DenmarkKgs LyngbyDenmark Food Safety and Zoonoses Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenStigb€ojlen 41870 Frederiksberg CDenmark Office for Innovation and Sector Services AdministrationTechnical University of DenmarkAnker Engelunds Vej2800 Kgs LyngbyDenmark Environment and Toxicology DHIHorsholmDenmark

Integration of acquired immunity into microbial risk assessment for illness incidence is of no doubt essential for the study of susceptibility to *** this study,a probabilistic model was set up as dose response for infection and a mathematical derivation was carried out by integrating immunity to obtain probability of illness *** acquire immunity from epidemiology studies which includes six different Norovirus transmission scenarios such as symptomatic individuals infectious,pre-and post-symptomatic infectiousness(low and high),innate genetic resistance,genogroup 2 type 4 and those with no immune boosting by asymptomatic infection were *** results on illness inflation factor as a function of dose and exposure indicated that high frequency exposures had immense immunity build up even at high dose levels;hence minimized the probability of *** Norovirus transmission dynamics data,results showed,and immunity included models had a reduction of 2e6 logs of magnitude difference in disease burden for both population and individual probable illness ***,the magnitude order of illness for each dose response remained largely the same for all transmission scenarios;symptomatic infectiousness and no immune boosting after asymptomatic infectiousness also remained the same *** integration of epidemiological data on acquired immunity into the risk assessment,more realistic results were achieved signifying an overestimation of probable risk of illness when epidemiological immunity data are not *** finding supported the call for rigorous integration of temporary acquired immunity in dose-response in all microbial risk assessments.

关键词： Quantitative risk assessment Probabilistic modeling Immunity integrated modeling

TUUKUSATION OF INDIGENOUS KNOWLEDGE IN RURAL LIVESTOCK FARMING IN UGANDA: A HOPE FOR BASIC AND SUSTAINABLE ANIMAL HEALTH CARE.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

TUUKUSATION OF INDIGENOUS KNOWLEDGE IN RURAL LIVESTOCK FARMI...

Replication of Prostate Cancer Risk Variants in a Danish Case-Control Association Study

面向21世纪的动物科学与动物医学国际研讨会

作者： EdwardSsewannyana CyprianEbong PeterT.dalsgaard Serere Agricultural and Animal Production Research Institute Namulonge Agricultural and Animal Production Research Institute Namulonge Agricultural and Animal Production Research Institute

＜正＞Animal health care is one of the key factors in developing a sustainable animal industry in any country. Healthy animals grow faster and produce better, giving the owners better dividends. In developing countries like Uganda, due to macro-level factors, farmers are finding it increasingly difficult to deal with agricultural input requirements and credits in times of

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Open Journal of Urology 2012年第2期2卷 45-54页

作者： Diem Nguyen Bentzon Mette Nyegaard Anders Borglum Torben Orntoft Michael Borre Karina dalsgaard Sorensen Department of Urology Aarhus University Hospital SkejbyAarhusDenmark Department of Human Genetics Aarhus UniversityAarhusDenmark Department of Molecular Medicine Aarhus University Hospital SkejbyAarhusDenmark

Background: Prostate cancer is one of the main causes for cancer morbidity and mortality in Western countries. Recently, several single nucleotide polymorphisms (SNPs) associated with prostate cancer have been identified in genome-wide association studies and multiple variant models have been developed to predict prostate cancer risk. The association between genetic markers and clinico-pathological tumor variables has, however, been inconsistent. Methods and Materials: A total of 32 previously identified prostate cancer-associated risk SNPs were genotyped in 648 prostate cancer cases and 526 age-matched controls. Family history was obtained by questionnaire. Age at diagnosis, clinical tumor variables including pre- and postoperative PSA, Gleason score, and T stage were obtained from prospectively collected clinical data (Aarhus Prostate Cancer Study). The SNPs were genotyped using Sequenom and Taqman assays and associations between SNPs, prostate cancer risk, and clinico-pathological variables were assessed. Results: Seventeen SNPs were successfully replicated in our case-control study and the association estimates were consistent with previous reports. Four markers were excluded from further analysis due to linkage disequilibrium. The cumulative effect of having the disease-associated genotype at five SNPs (rs4430796, rs6983267, rs1859962, rs1447295 and rs16901979) increased the prostate cancer risk with odds ratio 6.02 (95% CI: 2.21 - 16.38;P = 1.0 × 10–4) in patients with any combination of ≥4 markers compared with patients without any of the five SNPs (P for trend = 1.0 × 10–4). Six markers were significantly associated with clinico-pathological variables: SNP rs2735839 (GG) at locus 19q13, which is in the KLK3 gene encoding PSA, was associated with high preoperative PSA (P = 0.04), low Gleason score (P = 0.01) and low T stage (P = 0.02). Variants rs5759167 (GG/GT) (22q13) and rs7679673 (CC/CA) (4q24) were correlated with low risk for biochemical relapse (P = 0.

关键词： SNP Family History Cumulative Effect Biochemical Relapse Prostate Cancer Risk

Involvement of Cyclic Nucleotides and Potassium Channels in Hypoxic Vasodi-latation in Pig Coronary Arteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Involvement of Cyclic Nucleotides and Potassium Channels in ...

A New Furunculosis Challenge Method for Evaluation of Vaccine Efficacy in Rainbow Trout

第十五届国际药理学大会

作者： Nielsen Berit dalsgaard Frobert Ole Clunn Gerard Hughes Alun Simonsen Ulf Department of Pharmacology University of AarhusDK. Department of Pharmacology University of AarhusDK. Department of Clinical Pharmacology National Heart and Lung Institute London UK. Department of Clinical Pharmacology National Heart and Lung Institute London UK. Department of Pharmacology University of Aarhus DK.

＜正＞ We hypothesized that cyclic nucleotide-dependent pathways are pivotal for hypox-ia-induced coronary relaxation. Large pig coronary artery segments were mounted in myographs for isometric tension recording. Arteries were contracted with either K + or PGF2α and in the absence and presence of a protein kinase A （PKA） inhibitor or a K-channel-blocker, respectively, oxygen was gradually reduced （95%-0% ）. Intracellular calcium （[Ca2+]ic） was measured using Fura-2-AM. Following PGF2α（10-5M） contraction, arteries relaxed in proportion to the level of hypoxia. An inhibitor of PKA, Rp-CPT-cAMPS （100μM）, reduced hypoxic relaxation. Hypoxic relaxation was diminished by a blocker of BKCa2+-channels, Iberiotoxin （100 nM）, a blocker of KV-channels, 4-aminopyridine （0.5mM） and in arteries contracted with 30mM K+,respectively. Only a minor reduction was found with a blocker of KATP-channels, Glibenclamide （3x10-6M）. Hy-poxiainduced relaxation was associated with reduced [Ca2+]ic in PGF2α contracted arteries but not in 30mM K+ contracted arteries. Hypoxia relaxes coronary arteries by activation of PKA and by opening of potassium channels following lowering of [Ca2+]ic. Desensitization contributes to hypoxic relaxation.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Open Journal of Immunology 2016年第4期6卷 136-147页

作者： Moonika H. Marana Jiwan K. Chettri Jakob Skov Inger dalsgaard Per W. Kania Kurt Buchmann Department of Veterinary Disease Biology Faculty of Health and Medical Sciences University of Copenhagen Frederiksberg Denmark National Veterinary Institute Technical University of Denmark Frederiksberg Denmark

Experimental infection of fish for vaccine efficacy studies is associated with several limitations. Administration of live bacteria with the purpose of causing disease in fish can be performed by co-habitation, immersion or injection. We have developed a new Aeromonas salmonicida challenge method for rainbow trout and have applied it for evaluation of furunculosis vaccine efficacy. The method reveals development of systemic immunity in fish as live bacteria are introduced in the tail fin epidermis distant from the vaccine injection site (peritoneal cavity). This method seeks to mimic natural infection in fish farms where tail biting and therefore bacterial exposure to tail fin ulcers is widespread. By use of a multi-needle device ten epidermal perforations were introduced in the dorsal part of the tail fin of anaesthetized rainbow trout (vaccinated or naive). Subsequently 100 μL (3.4 × 108 colony-forming units (CFU) mL-1) of a 48 hour culture of Aeromonas salmonicida subsp. salmonicida strain 090710-1/23 was placed at the perforation site for 60 sec whereafter fish were allowed to regain consciousness in clean freshwater. Immunohistochemistry and scanning electron microscopy illustrated the spread of bacteria from the injection site. Classical furunculosis symptoms associated with a high morbidity rate were observed in control fish whereas vaccinated fish exhibited a significantly higher survival.

关键词： Aeromonas salmonicida Challenge Method Furunculosis Immunization Salmonids