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1.
Numerous studies reported the adaptation strategies adopted by ecthotherms to survive under environmental thermal stress. Geographic and seasonal variations in the thermal stress tolerance, which is closely associated with species' climatic adaptation and allopatric speciation, have been extensively investigated in insects. The variation patterns suggest directional selection for species' adaptive straits, and are used to predict the origin, distribution and dynamics of insect populations. These studies are becoming more and more important in the context of global warming. This paper discusses the process of adaptation to environmental thermal stress and the mechanisms underlying the differentiation in related adaptive straits of insect populations.  相似文献   

2.
Potentials for Radio Frequency Identification in AEC/FM   总被引:1,自引:0,他引:1  
Radio frequency identification (RFID) technology has proved to be very effective in industries as diverse as aircraft manufacturing to health and care. The construction industry has been slow to take up on RFID and this paper will discuss the merits of the technology in its potential for application within the construction sector. The paper reports about the prototypical implementation of RFID-based information management in FM-scenarios. The prototypes were tested at University College Cork (UCC). The general applicability of RFID for decentralised information management could be demonstrated.  相似文献   

3.
[美国]University of NebraskaThe Department of Biochemistry and Molecular Biology invitesapplications for a position at the rank of Associate/Full Professor.Qualifications include a PhD or MD degree and relevantexperience.Preference will be given to outstanding candidateswho can utilize state-of-the-art biochemical,molecular,and arrayapproaches to epigenetic research aimed at a better understandingof cancer etiology/diagnosis.The ideal candidates will haveresearch interests and experience that will supplement ongoingresearch in the Department(website:http://www.unmc.edu/Biochemistry/).The successful applicant will be expected to havea well-funded,  相似文献   

4.
This study used the sequence of the mitochondrial Cytochrome b(Cytb)to estimate phylogenetic relationships among host Hepialidae insects of Cordyceps sinensis.Genome DNA of host insect was extracted from the dead larva head part of 18 cordyceps populations and 2 species of Hepialus,and the Cytb fragment of host insect was amplified with PCR technique.The nucleotide sequence alignments and their homologous sequences of 24 species host Hepialidae insects of Cordyceps sinensis were obtained from GenBank and were used to construct phylogenetic trees based on neighbor-joining method.The results showed that genus Bipectilus diverged earlier than genus Hepialus and Hepialiscus.Hepialus host insects of Cordyceps sinensis have multitudinous species with different morphological characteristics and geographical distributions.The interspecific genetic differentiations are obvious in Hepialus.Thus,the genus Hepialus might be considered as polyphyletic origin.Cytb sequences have abundant variations among the host insects of Cordyceps sinensis on spe- cific and generic level.The divergence rate of Cytb sequences among the species in Hepialus ranged from 0.23% to 9.24%,except that Hepialus pratensis and Hepialus jinshaensis have the same sequence.Cytb sequence can be used for species identification of host insects of Cordyceps sinensis,but further confirmation in more host insect species is needed.To obtain the Cytb sequence of host insect by ampli- fying DNA extracted from the head part of dead larva in cordyceps turns out to be an effective and accurate approach,which will be useful for studies on phylogeny and genetic structure of host insects of cordyceps populations,especially for analyzing relationships between C. sinensis and its host insects.  相似文献   

5.
Genetics is assuming an increasingly important role in medicine. As a result, the teaching of genetics should also be increased proportionally to ensure that future physicians will be able to take advantage of the new genetic technology, and to understand the associated ethical, legal and social issues. At the University of Rochester School of Medicine and Dentistry, we have been able to incorporate genetic education into a four-year medical curriculum in a fully integrated fashion. This model may serve as a template for other medical curriculum still in development.  相似文献   

6.
Although the huge potential of the northern South China Sea deepwater basins has been proven by a series of discoveries that followed the exploration breakthrough of well LW 3-1-1, recent drilling and other studies have demonstrated the uniqueness and complicated nature of hydrocarbon accumulations of the deepwater basins there. Based on a review of previous work and the latest exploration activities and studies, the purpose of this paper is to discuss the critical controls for hydrocarbon accumulations in the deepwater basins of the northern South China Sea. A terrestrial-marine transitional coal-bearing source rock is proposed to be the primary source rock for the deepwater basins. A marine source rock, which was first identified as contributing to hydro-carbon generation in this region, probably plays a significant role in the deep-and ultra-deep water basins south to the Pearl River Mouth and Qingdongnan basins. The shelf margin delta depositional systems in the Baiyun Sag, sourced from the Pearl River, are currently primary exploration targets in the deepwater part of the Pearl River Mouth Basin, whereas the western Red River delta-ic-submarine fan depositional systems, initially proven by drilling, are the possible major exploration reservoirs in the Qing-dongnan deepwater areas. Current deepwater exploration targets at the large-sized structural traps and deep and ultra-deep areas in the south of the Pearl River Mouth and Qingdongnan basins will be the future exploration focus. Deepwater exploration activities and relevant fundamental studies, supporting and promoting each other, are of great importance to the national energy supply of China, the basic regional studies of the South China Sea, advancements in technology, and development of related deepwater industries, and will safeguard national sovereignty and territorial integrity.  相似文献   

7.
正博士后[美国]Arizona State UniversityThe Inflammation and Cancer Laboratory at the Biodesign Institute at Arizona State University is searching for a postdoctoral research associate to join their team devoted to understanding how inflammation and inflammatory mediators contribute to colorectal carcinogenesis.This position will focus on the molecular and genetic basis of colorectal cancer formation and progression.The  相似文献   

8.
In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ‘‘accessibility hypothesis' '. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference(RNAi) and other func- tional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic- modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations.  相似文献   

9.
The perennial Medicago sativa cv. Gabes is widely grown on saline soils in Tunisian oases. Morphological and physiological analyses of two populations (Mareth and Gannouch) were conducted in order to study the effect of salinity and gamma radiation (350 Gy) interaction on two populations of this species. It has been shown that the two irradiated populations of Medicago sativa are fairly tolerant to salt at growth phase compared to the non-irradiated. Exposure to gamma irradiation (350 Gy), alone or in combination with salt stress, increased significantly (p 〈 0.001) shoot number, stem height and chlorophyll b pigment especially for the Gannouch population, while no change occurred for the Mareth population. The presence of salt to 9 g/1 affected significantly the root biomass and induced a reduction of shoot development of both control and irradiated alfalfa populations. For all treatments, plants of two populations remained able to produce and to allocate dry matter to the different organs. The survey of Na^+/K^+ ratio showed that the growth of the aerial organs of two non-irradiated populations was at least determined by a selectivity in favour of the K^+ ions (r^2 = 0.97 and r^2 = 0.59 for Mareth and Gannouch non-irradiated populations, respectively). However, the rather weak correlation detected for the irradiated populations, particularly for the irradiated Gannouch, seems to be the consequence of the effect of irradiation that improved potassium availability, essential element for growth and development. Results also showed that the two irradiated populations, especially the Mareth, accumulated Na^+ ions in its photosynthetic organs. This accumulation was associated with an improvement of foliar water content at a level of salinity around 5 g/1. Such a mechanism reflects probably an inclusive behaviour of the plants and a good aptitude to use the dominant ions (Na^+) for the osmotic adjustment. However, the non-irradiated populations are unable to adjust their internal os  相似文献   

10.
Important advances in research of sulphide ore textures in recent years have deepened our understanding of ore genesis of related mineral deposits. Pressure solution of sulphide minerals has been suggested as a mechanism for remobilization of ore materials, whereas pressure solution of the gangues is believed to raise the grade of the primary ores. We have known that precipitation of base metal sulphides from fluids prefers crystal and crack surfaces of pyrite to form overgrowth. Therefore, pyrite-bearing embryo beds in a sedimentary sequence can be acted as effective crystal seed beds and are favorable for fluid overprinting to form huge statabound deposits. Texture studies of various sulphides can be used to interpret the entire history of sedimentation, diagenesis, deformation and metamorphism of the ores. The study of chalcopyrite disease in sphalerite has brought about the idea of zone refining, and given a new explanation to metal zonation in massive sulphide deposits. Ductile shearing of sulphide ores may form ore mylonites, which will become oreshoots enriched in Cu, Au and Ag during late-stage fluid overprinting. Despite that various modern analytical techniques are being rapidly developed, ore microscopy remains to be an unreplaceable tool for ore geologists. Combined with these modern techniques, this tool will help accelerate the development of theories on ore genesis.  相似文献   

11.
The nitrogen isotope signatures in the sediments amended by seal excrements, from Fildes Peninsula of King George Islands, Antarctica, were examined for their paleoecological application potential. The contents of total organic carbon (TOC) and total nitrogen (TN) and the atomic C/N ratios in the sediments show that the organic carbon and nitrogen are predominantly of marine origin and derived from seal excrements. The remarkably high δ15N values in the sediments may be related to at least two important factors of trophic enrichment and NH3 volatilization, which requires further studies. The large variations in the seal hair abundances and the determinedδ15N values in the sediments signify similar changes of the historical seal populations around the study site. A significant negative correlation between the δ15N values and seal hair abundance was observed, and this suggests that the δ15N values, like the number of seal hairs,can be used as a paleoecological proxy for the historical seal populations. The time-integrated δ15N signatures in the sediments with predominantly animal-derived nitrogen source thus provide a new tool for estimating historical populations of seals and penguins and interpretlng the underlying paleoecological processes.  相似文献   

12.
13.
肖卫 《科技信息》2013,(24):185-187
Translating is a cross-cultural activity,and value is an important element of it.Therefore,it is undoubtedly that value will play an important role in English-Chinese translation,which is a learned organization of rules for making choices and resolving conflicts.These rules may serve to teach us to distinguish right and wrong,good and evil,what can be done and what cannot be.Accordingly,in this thesis,the notable differences in values in English-Chinese translation will be firstly dealt with,and then the main presentations of the value differences in English-Chinese translation will be analyzed.Furthermore,some effective methods to solve value-bound problems in English-Chinese translation will be discussed.  相似文献   

14.
《清华大学学报》2005,10(5):560-560
Tsinghua University and the University of Waterloo signed their first Memorandum of Understanding for Educational and Scientific Cooperation on June 17, 2005. As one of Canada’s leading research universities, the University of Waterloo was ranked most innovative among 47 universities in Canada in 2004, according to the national magazine Maclean’s. Its School of Computer Science has been ranked first across Canada and is famous in the world. This MOU will provide a platform for the ex…  相似文献   

15.
Meta-analysis and its application in global change research   总被引:3,自引:0,他引:3  
Meta-analysis is a quantitative synthetic research method that statistically integrates results from in- dividual studies to find common trends and differences. With increasing concern over global change, meta-analysis has been rapidly adopted in global change research. Here, we introduce the methodolo- gies, advantages and disadvantages of meta-analysis, and review its application in global climate change research, including the responses of ecosystems to global warming and rising CO2 and O3 concentrations, the effects of land use and management on climate change and the effects of distur- bances on biogeochemistry cycles of ecosystem. Despite limitation and potential misapplication, meta-analysis has been demonstrated to be a much better tool than traditional narrative review in synthesizing results from multiple studies. Several methodological developments for research synthe- sis have not yet been widely used in global climate change researches such as cumulative meta-analysis and sensitivity analysis. It is necessary to update the results of meta-analysis on a given topic at regular intervals by including newly published studies. Emphasis should be put on multi-factor interaction and long-term experiments. There is great potential to apply meta-analysis to global climate change research in China because research and observation networks have been established (e.g. ChinaFlux and CERN), which create the need for combining these data and results to provide support for governments’ decision making on climate change. It is expected that meta-analysis will be widely adopted in future climate change research.  相似文献   

16.
The 364-bp nucleotide sequence in hypervariable region I (HVRI) of mitochondrial DNA is successfully amplified from 9 out of 11 individuals of an ancient population buried in the Jiangjungou Cemetery in Inner Mongolia dated back to the Warring States Period in China. Nine fragments with different variations are obtained. A phylogenetic tree and a multidimensional scaling (MDS) plot are constructed using mtDNA sequences from the ancient population and several modern Asian populations. The results show that ancient population shares a closer genetic relationship with East Asian populations than with North and Central Asian populations. The genetic and historical evidence raise the possibility that the population might be the immigrants from Zhongyuan area, sent by the King Wuling of Zhao State to guard the nation against the attack from Huns.  相似文献   

17.
Abstract: As the most significant water project, the Three Gorges Project (TGP) was designed to take care of multiple objectives for water utilization such as flood control, power generation and navigation. The implementation of the project will improve the flood safety level of Jingjiang reach to more than 100-year return period, which will reduce greatly the flood risk at the mid-lower reaches of Changjiang River, produce huge quantity of energy for the central, east and south China, and improve significantly the navigation conditions of Chuanjiang River. Meanwhile, the operation of the TGP in dry season which will compensate the downstream water resources, will as well deepen the navigation channel and thus improve the navigation conditions in the middle river reach. With the increasing demands raised from various aspects of the society, new requirements will be made for the TGP for the purpose of harnessing, development and protection of the Yangtze River Basin. Therefore, it will be a long-term task for the operation of TGP on how to optimize the water resources utilization and implement an effective operation.  相似文献   

18.
Cytokinin plays a critical role in plant growth and development by regulating cell divisions and cell differentiation. Recent studies suggest that cytokinin signaling is presumably mediated by a two-component system analogous to those found in bacteria and fungi, which transduces an external signal via a phosphorelay from the plasma membrane-anchored receptors to downstream effectors and regulators. Moreover, cytokinin signaling is highly interactive with other pathways, and many components of the pathway appear to be functionally redundant. Proper address of these questions will be crucial for our further understanding on this important network.  相似文献   

19.
正博士后[美国]Northwestern University Northwestern University opens a post-doctoral researcher position.The focus of their research is Alzheimer’s disease pathogenesis withparticular emphasis on the beta-secretase enzyme,BACE1.Thepostdoctoral research project will include investigations of the role ofBACE1 in Alzheimer’s disease and its potential as a therapeutictarget,and the normal physiological functions of the enzyme in vivo.Applicants must have a PhD in a field of the life sciences and/or MDdegree.Preference will be given to individuals with expertise in  相似文献   

20.
朱新平  Zhou  Li  Chen  Yongle  Du  Hejun  Gui  Jianfang 《高技术通讯(英文版)》2008,14(1):104-111
Mauremys mutica (Cantor, 1842) is an endangered species in China. Main phenotypic variations in body color, body weight, body shape, clutch size, egg size, and hatchling size were revealed between the southern and northern populations. Both populations have the phenomenon of "larger male" sexual size dimorphism (SSD), especially in the southern population. Furthermore, genetic variations between the two populations were analyzed by RAPD band patterns of 30 random individuals in each population. The average genetic distance was 0.299±0.108 among the samples of two populations. The average genetic distance between southern and northern populations was 0.305±0.046. Cluster analysis indicated that all the individuals from the southern and northern populations were clustered among themselves to form two distinct clades. A total of 20 population-specific RAPD fragments were scored from 16 primers, and could be used as RAPD markers for distinguishing the southern and the northern population. Based on the nucleotide sequences of two RAPD markers, two pairs of SCAR primers (SC1-S and SC2-S) were designed, which could be used as SCAR markers for the southern population. According to the significant phenotypic and genetic variations, we suggested that the northern population and southern population might be considered as two separate taxa, the "northern taxon" and the "southern taxon", and the conservation should be respectively conducted on the two taxa.  相似文献   

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