检索结果-南通市图书馆

Morphology and morphometry of two hybridizing buntings at their hybrid zone in northern Iran reveal intermediate and transgressive morphotypes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Avian Research 2023年第4期14卷 523-532页

作者： Ali Gholamhosseini Mansour Aliabadian Till Topfer Glenn-peter sætre Ornithology Research Laboratory Department of BiologySchool of ScienceShiraz UniversityShirazIran Department of Biology Faculty of SciencesFerdowsi University of MashhadMashhadIran Leibniz Institute for the Analysis of Biodiversity Change Zoological Research Museum Alexander KoenigCentre for Taxonomy and MorphologyBonnGermany Centre for Ecological and Evolutionary synthesis(CEEs) Department of BiosciencesUniversity of OsloNorway

The closely related Black-headed Bunting(Emberiza melanocephala,a western Palearctic lineage)and Red-headed Bunting(Emberiza bruniceps,an eastern Palearctic lineage)hybridize and replace each other south of the Caspian *** parental species have distinct phenotypes and therefore morphology is useful for assessing hybridization in the contact *** the years of 1940 and 1977,quite a few hybrids were collected and studied *** then,the hybrid zone appears to have expanded westwards,but there has been a time gap in the collection of morphological *** we reanalyze bunting specimens morphologically and compare the historical data with recent *** and phenotypic traits from three time periods(1940,1977 and recent)were studied to assess phenotypic variation of hybrids,pattern of hybridization,and transgressive traits in the hybrid *** results show that most of the birds in the hybrid zone exhibit intermediate phenotypes(both colors and morphometric characters),ranging from the pure phenotype of either of the parental ***,hybridization has also produced novel phenotypes not seen in any of the *** a canonical discriminant function analysis,the morphometric characters separated each parental species and the hybrids quite *** results showed morphometric intermediacy of hybrids in accordance with *** observe a time trend in which recent hybrids are more similar to Red-headed Buntings phenotypically compared to historical *** pattern is likely a signature of a westward expansion of the Red-headed Bunting into the breeding range of the Black-headed Bunting.

关键词： Bunting Hybridization Intermediate phenotypes Transgressive traits

A portfolio approach to managing ecological risks of global change

在线全文

学校读者我要写书评

暂无评论

Ecosystem Health and sustainability 2017年第2期3卷 1-16页

作者： Gregory H.Aplet peter s.McKinley The Wilderness society 1660 Wynkoop StreetSuite 850DenverColorado 80202 USA The Wilderness society 9 Union StreetSecond FloorHallowellMaine 04347 USA

The stressors of global environmental change make it impossible over the long term for natural systems to maintain their historical ***’s new objective must be to maintain the building blocks of future systems(e.g.,species,genes,soil types,and landforms)as they continuously *** of the certainty of change,some biologists and managers question continued use of retrospective conservation strategies(e.g.,reserves and restoration)informed by the historical range of *** strategies that manage toward anticipated conditions have joined the conservation toolbox alongside retrospective *** argue that high uncertainty around the rates and trajectories of climate and ecological change dictate the need to spread ecological risk using prospective and retrospective strategies across conservation networks in a systematic and adaptively managed *** term this a portfolio approach drawing comparisons to financial portfolio risk management as a means to maximize conservation benefit and *** with a financial portfolio,the portfolio approach requires that management allocations receive minimum temporal commitments to realize longer-term *** approach requires segregation of the strategies into three landscape zones to avoid counterproductive *** zones will be managed to(1)observe change,(2)resist change,and(3)facilitate *** offer guidelines for zone allocation based on ecological *** zones should follow principles of conservation design traditionally applied to *** to financial portfolios,zone performance is monitored to facilitate learning and potential reallocation for long-term net minimization of risk to the building blocks of future ecosystems.

关键词： adaptive management biodiversity connectivity global change gradients portfolio reserve restoration risk spreading transformation

Polaron Effect of a Two Electron Parabolic Quantum Dot

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

Communications in Theoretical Physics 2013年第6期59卷 763-768页

作者： s.saravana Kumar A.John peter Chang Kyoo Yoo Department of Physics Nadar Saraswathi College of Engineering and Tecchnology Vadapudupatti Department of Physics Government Arts College Center for Environmental studies/Green Energy Center Department of Environmental Science and Engineering Collegeof Engineering Kyung Hee University

Polaron induced double electron in a quantum dot is investigated using the exact diagonalization techniques and the compact density-matrix approach. The dependence of nonlinear optical processes on the incident photon energies and the polaronic effect are brought out. The linear, third order non-linear optical absorption coefficients and the refractive index changes of singlet and triplet states as a function of photon energy are obtained with and without the inclusion of polaronic effect. It is found that the geometrical confinement and the effect of polaron have great influence on the optical properties of dots.

关键词： parabolic quantum dot correlation energy semiconductor

Tekcrete Fast~: Fiber-reinforced, rapid-setting sprayed concrete for rib and surface control

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining science and Technology 2018年第1期28卷 29-34页

作者： stephen C.Tadolini peter s.Mills David R.Burkhard Minova UsA IncGeorgetownKYUSA san Juan Coal Company WaterflowNMUSA

Fiber-reinforced spayed concrete has been used for several years in civil and tunneling *** conducted to reduce cure times and increase compressive and flexural strengths resulted in the development of Tekcrete Fast~, a cementitious product capable of obtaining 41 MPa compressive strength and 8 MPa flexural strength in only 3 h and reaching 7 d strengths of 62 and 11.7 MPa, respectively.A single bag product that uses conventional shotcrete and gunite application systems makes it a natural crossover product for mining *** discovery of incredible adhesion properties and high resistance to chloride permeability helps ensure long-term stability and increases the ease of *** results from Disaster City~ in Texas and the application for rehabilitating a coal mine belt entry are *** case study illustrates the effectiveness of the product in stabilizing a coal mine beltway and adjacent cross-cuts that were subjected to progressive sloughage due to humidity and cyclical loading.

关键词： sprayed concrete Coal mine High strength concrete Polypropylene fiber

Composite recommendations： from items to packages

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer science 2012年第3期6卷 264-277页

作者： Min XIE Laks V. s. LAKsHMANAN peter T. WOOD Department of Computer science University of British Columbia Vancouver V6T 1Z4 Canada Department of Computer science and Information systems Birkbeck University of London London WCIE 7HX UK

Classical recommender systems provide users with a list of recommendations where each recommendation consists of a single item, e.g., a book or DVD. However, sev- eral applications can benefit from a system capable of recom- mending packages of items, in the form of sets. sample appli- cations include travel planning with a limited budget （price or time） and twitter users wanting to select worthwhile tweeters to follow, given that they can deal with only a bounded num- ber of tweets. In these contexts, there is a need for a system that can recommend the top-k packages for the user to choose from. Motivated by these applications, we consider composite recommendations, where each recommendation comprises a set of items. Each item has both a value （rating） and a cost associated with it, and the user specifies a maximum total cost （budget） for any recommended set of items. Our composite recommender system has access to one or more component recommender systems focusing on different do- mains, as well as to information sources which can provide the cost associated with each item. Because the problem of deciding whether there is a recommendation （package） whose cost is under a given budget and whose value exceeds some threshold is NP-complete, we devise several approximation algorithms for generating the top-k packages as recommen- dations. We analyze the efficiency as well as approximation quality of these algorithms. Finally, using two real and two synthetic datasets, we subject our algorithms to thorough ex- perimentation and empirical analysis. Our findings attest tothe efficiency and quality of our approximation algorithms for the top-k packages compared to exact algorithms.

关键词： recommendation algorithms optimization,top-k query processing

Changes in various metabolic parameters in blood and milk during experimental Escherichia coli mastitis for primiparous Holstein dairy cows during early lactation

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

Journal of Animal science and Biotechnology 2015年第1期6卷 37-46页

作者： Kasey M Moyes Torben Larsen peter s?rensen Klaus L Ingvartsen Department of Animal and Avian sciences University of Maryland142 Animal Sciences BuildingMD 20742-231120910 College ParkMDUSA Department of Animal science Faculty of Science and TechnologyAarhus University

Background： The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli （E. coh. for dairy cows during early lactation. Thirty, healthy primiparous Holstein cows were infused （h = 0） with -20-40 cfu of live E. coil into one front mammary quarter at -4-6 wk in lactation. Daily feed intake and milk yield were recorded. At -12, 0, 3, 6, 12, 18, 24, 36, 48, 60, 72, 96, 108, 120, 132, 144, 156, 168, 180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E. coil Composite milk samples were collected at -180, -132, -84, -36, -12, 12, 24, 36, 48, 60, 72, 84, 96, 132 and 180 h relative to challenge （h=0） and analyzed for lactate dehydrogenase （LDH）, somatic cell count, fat, protein, lactose, citrate, beta-hydroxybutyrate （BHBA）, free glucose （fglu）, and glucose-6-phosphate （G6P）. Blood was collected at -12, 0, 3, 6, 12, 18, 24, 36, 60, 72, 84, 132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids （NEFA）, BHBA and glucose concentration. A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation. Results： By 12 h, E. coli was recovered from challenged quarters and shedding continued through 72 h. Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge. Daily feed intake and milk yield decreased （P 〈0.05） by 1 and 2 d, respectively, after mastitis challenge. Plasma BHBA decreased （12 h, P 〈0.05） from 0.96± 1.1 at 0 h to 0.57±0.64 mmol/L by ]8 h whereas concentration of plasma NEFA （78 h） and glucose （24 h） were significantly greater, 11 and 27%, respectively, after challenge. In milk fglu, lactose, citrate, fat and protein yield were lower whereas yield of BHBA and G6P were higher after challenge when compared to pre-challenge values. Conclusion

关键词： Cow Early lactation Escherichia coli Metabolism

Novel oncogenes and tumor suppressor genes in hepatocellular carcinoma

在线全文

学校读者我要写书评

暂无评论

Liver Research 2021年第4期5卷 195-203页

作者： Fang Wang peter Breslin s J Wei Qiu Department of surgery and Cancer Biology Loyola University Chicago Stritch School of MedicineMaywoodILUSA Department of Molecular/Cellular Physiology Cancer BiologyCardinal Bernardin Cancer CenterLoyola University Medical Centerand BiologyLoyola University ChicagoChicagoILUSA

Hepatocellular carcinoma(HCC)is a very deadly *** initiation and progression involve multiple genetic events,including the activation of proto-oncogenes and disruption of the function of specific tumor suppressor *** of oncogenes stimulates cell growth and survival,while loss-of-function mutations of tumor suppressor genes result in unrestrained cell *** this review,we summarize the new findings that identified novel proto-oncogenes and tumor suppressors in HCC over the past five *** findings may inspire the development of novel therapeutic strategies to improve the outcome of HCC patients.

关键词： Hepatocellular carcinoma(HCC) Oncogene Tumor suppressor Activation Loss-of-function

Application of the health risk assessment of acetochlor in the development of water quality criteria

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

Journal of Environmental sciences 2021年第12期33卷 48-54页

作者： Wei An Chenhui sang Kristian Marienlund Jensen peter Borgen sørensen Bin Zhang Min Yang Key Laboratory of Drinking Water science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China sino-Danish College University of Chinese Academy of SciencesBeijing 100190China Department of Bioscience Aarhus UniversityVejlsovej 25PO BOX 314SilkeborgDenmark University of Chinese Academy of sciences Beijing 100049China Department of Mathematical sciences Tsinghua UniversityBeijing 100084China

Acetochlor is a widely used herbicide in agricultural production. studies have shown that acetochlor has obvious environmental hormone effects, and long-term exposure may pose a threat to human health. To quantify the hazards of acetochlor in drinking water, a health risk assessment of acetochlor was conducted in major cities of China based on the data of acetochlor residue concentrations in drinking water. The approach of the species sensitivity Distributions(ssD) method is used to extrapolate from animal testing data to reflect worst case human toxicity. Results show that hazard quotients related to acetochlor residues in drinking water for different age groups range from 1.94 × 10-4 to 6.13 × 10-4, so, there are no indication of human risk. Compared to the total estimated hazard quotient from oral intake of acetochlor, the chronic exposure imputed to acetochlor residues in drinking water in China accounts for 0.4%. This paper recommends 0.02 mg/L to be the maximum acetochlor residue concentration level in drinking water and source water criteria.

关键词： Acetochlor Drinking water source water Contribution rate species sensitivity distributions(ssD)

Identification of stable normalization genes for quantitative real-time PCR in porcine articular cartilage

在线全文

学校读者我要写书评

暂无评论

Journal of Animal science and Biotechnology 2012年第4期3卷 181-187页

作者： Ryan s McCulloch Melissa s Ashwell Audrey T O'Nan peter L Mente Joint Department of Biomedical Engineering North Carolina State University University of North Carolina Animal science Department North Carolina State University

Background： Expression levels for genes of interest must be normalized with an appropriate reference, or housekeeping gene, to make accurate comparisons of quantitative real-time PCR results. The purpose of this study was to identify the most stable housekeeping genes in porcine articular cartilage subjected to a mechanical injury from a panel of 10 candidate genes. Results： Ten candidate housekeeping genes were evaluated in three different treatment groups of mechanically impacted porcine articular cartilage. The genes evaluated were： beta actin, beta-2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, hydroxymethylbilane synthase, hypoxanthine phosphoribosyl transferase, peptidylprolyl isomerase A （cyclophilin A）, ribosomal protein L4, succinate dehydrogenase flavoprotein subunit A, TATA box binding protein, and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein--zeta polypeptide The stability of the genes was measured using geNorm, BestKeeper, and NormFinder software. The four most stable genes measured via geNorm were （most to least stable） succinate dehydrogenase flavoprotein, subunit A, peptidylprolyl isomerase A, glyceraldehyde-3-phosphate dehydrogenase, beta actin; the four most stable genes measured via BestKeeper were glyceraldehyde-3-phosphate dehydrogenase, peptidylprolyl isomerase A, beta actin, succinate dehydrogenase flavoprotein, subunit A; and the four most stable genes measured via NormFinder were peptidylprolyl isomerase A, sucdnate dehydrogenase flavoprotein, subunit A, glyceraldehyde-3-phosphate dehydrogenase, beta actin. Conclusions： BestKeeper, geNorm, and NormFinder all generated similar results for the most stable genes in porcine articular cartilage. The use of these appropriate reference genes will facilitate accurate gene expression studies of porcine articular cartilage and suggest appropriate housekeeping genes for articular cartilage studies in other species.

关键词： Cartilage Housekeeping Normalization Porcine Reference stability