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Status of microsatellites as genetic markers in cervids 被引量:1
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作者 徐艳春 潘紫辰 +3 位作者 许志茹 杨淑慧 金煜 白素英 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第1期55-58,共5页
Microsatellite loci distributing on genome randomly act as effective genetic markers. To date, about 200 microsatellite loci were found in cervids b y transferring microsatellite PCR primers derived in bovine, ovine ... Microsatellite loci distributing on genome randomly act as effective genetic markers. To date, about 200 microsatellite loci were found in cervids b y transferring microsatellite PCR primers derived in bovine, ovine to cervids, a s well as a few loci derived directly from deer microsatellite library. These lo ci have been used in parentage determination, genetic diversity and population s tructure, population introgression, as genetic marker gestation length and winte ring survival et al. However, microsatellite loci presently found are untouchabl e to the demand of application. Future work should include: 1) isolating a large number of cervine microsatellite loci, 2) constructing genetic and physical map s of microsatellite loci. So that microsatelites have a strong base for advanced applications in deer. 展开更多
关键词 DEER CERVIDS MICROSATELLITE Genetic marker
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Two newly recorded species of the genus Hypsibius (Tardigrada;Hypsi-biidae) from China 被引量:3
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作者 王立志 廉振民 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期340-342,共3页
This paper reported two newly recorded species, Hypsibius convergens Urbanowicz, 1925 and Hypsibius hypostomus Bartos, 1935, of the genus Hypsibius (Tardigrada; Hypsibiidae) from China. Both species were collected f... This paper reported two newly recorded species, Hypsibius convergens Urbanowicz, 1925 and Hypsibius hypostomus Bartos, 1935, of the genus Hypsibius (Tardigrada; Hypsibiidae) from China. Both species were collected from Taibai Mt, Shaanxi Province. All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, China. 展开更多
关键词 TARDIGRADA Hypsibius TAXONOMY new record China
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新作推荐
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《职业技术教育》 北大核心 2003年第35期49-49,共1页
关键词 《永不畏惧永不放弃》 《职场政治》 《通稿 2003》 《动物记》 人力资源管理 英雄主义 韩寒
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Pharmacokinetics of exendin-4 in Wistar rats
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作者 艾国 陈知航 +3 位作者 单成启 车津晶 侯禹男 程远国 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第1期6-10,共5页
To characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of exendin-4 in healthy Wistar rats were studied. Exendin-4 was radioiodinated by the IODOGEN (1,3,4,6-tetrachloro-3 alpha,... To characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of exendin-4 in healthy Wistar rats were studied. Exendin-4 was radioiodinated by the IODOGEN (1,3,4,6-tetrachloro-3 alpha, 6 alphadiphenylglucoluril) method. Pharrnacokinetic properties of ^125I-exendin-4 were examined after a single s.c. and i.v. injection, respectively. Tissue distri- bution and urinary, fecal, and biliary excretion patterns of ^125I-exendin-4 were also investigated following a single s.c. injection. Exendin-4 was rapidly distributed and cleared with t1/2 of (0.48 ± 0.03) h after a single i.v. injection. Following a single s.c. administration, exendin-4 exhibited rapid and considerable absorption with Tmax of (0.25± 0.02) h and declined with the elimination t1/2 of(1.28± 0.14) h. The absolute bioavailability was (65.5 ± 10.2) %. The radioactivity was widely distributed and rapidly diminished in most tissues. The kidney contained the highest radioactivity and the distribution of ^125I-exendin-4 to the brain was minimal. The major elimination route was urinary excretion. The pharmacokinetic properties of exendin-4 obtained from the present study closely matched those reported in previous studies in rats. Pharmacokinetics profiles of exendin-4 in rats are warranted for the design of future clinical trials. 展开更多
关键词 Exendm-4 IODINE PHARMACOKINETICS
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Genetic variation in two sea cucumber (Apostichopus japonicus) stocks revealed by ISSR markers 被引量:3
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作者 姚冰 胡晓丽 +2 位作者 包振民 陆维 胡景杰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2007年第1期91-96,共6页
Sea cucumber Apostichopus japonicus samples were collected in Changdao, Penglai (PL), 27 individuals, and Lingshandao, Qingdao (QD), 30 individuals, in the Shandong Peninsula, China. Ten SSR primers were used to asses... Sea cucumber Apostichopus japonicus samples were collected in Changdao, Penglai (PL), 27 individuals, and Lingshandao, Qingdao (QD), 30 individuals, in the Shandong Peninsula, China. Ten SSR primers were used to assess the genetic variation and relationship between and within the two stocks. Respectively, for each stock, the percentage of polymorphic bands was 85.2% and 86.9%; the gene diver- sity was 0.360 5 and 0.342 8; and the Shannon’s information index was 0.515 0 and 0.499 0. At species level, the percentage of polymorphic bands was 92.2%, the total gene diversity was 0.378 9 and the Shannon’s information index was 0.550 4. The coefficient of overall genetic differentiation and the ge- netic distances between the stocks were also calculated to be 0.073 0 and 0.079 6 using the POPGENE program. Results show that the genetic diversity of the two stocks is still large but the genetic distance between the two stocks is close. A dendrogram was constructed for the 57 individuals from the two stocks, showing that the genetic structure was unitary for PL stock but complex for QD stock. 展开更多
关键词 sea cucumber Apostichopusjaponicus ISSR STOCK genetic diversity
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RADIOIODINATION AND PHARMACOKINETICS OF BIVALENT ANALOG OF PRACTOLOL AS MYOCARDIAL IMAGING AGENT
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作者 曹国宪 李卫一 +1 位作者 张荣军 俞惠新 《Nuclear Science and Techniques》 SCIE CAS CSCD 1995年第4期238-240,共3页
Solid phase exchange radioiodination method was used to label the compound.Pharmacokinetics was studied in rats and the data were dealt with by computer. The results indicate that the compound would be a potential myo... Solid phase exchange radioiodination method was used to label the compound.Pharmacokinetics was studied in rats and the data were dealt with by computer. The results indicate that the compound would be a potential myocardial imaging agent. 展开更多
关键词 Bivalent analog of practolol RADIOIODINATION PHARMACOKINETICS Myocardial imaging agent  ̄(125)I
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Toxicity of Chlorpyrifos and Dimethoate to the Ciliate Urostyla grandis, with Notes on Their Effects on Cell Ultrastructure
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作者 MU Weijie WARREN Alan +1 位作者 PAN Xuming YING Chen 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第3期697-704,共8页
Chlorpyrifos and dimethoate are overused agricultural pesticides that can trigger trophic cascades, resulting in toxicity to both terrestrial and aquatic organisms as well as altered ecosystems. In previous studies, s... Chlorpyrifos and dimethoate are overused agricultural pesticides that can trigger trophic cascades, resulting in toxicity to both terrestrial and aquatic organisms as well as altered ecosystems. In previous studies, substantial attention has been given to the effects of pesticides on vertebrate species and, to a lesser extent, species of zooplankton. The present study was designed to show that the fission time effective concentration in ciliates is a potential aquatic detection index for environmental monitoring. The ciliate Urostyla grandis was treated with doses of chlorpyrifos and dimethoate. After exposed to the pesticides, the LC_(50)(i.e., concentration that killed 50% of the ciliate cells within 24 h) values were 0.029 mg L^(-1) for chlorpyrifos and 0.0685 mg L^(-1) for dimethoate. The fission time effective concentrations after 168 h of exposure were 0.0075–0.0093 mg L^(-1) for chlorpyrifos and 0.2640–0.2750 mg L^(-1) for dimethoate. These results show that the fission time effective concentration is lower than the LC_(50) value in ciliates, indicating that fission time effective concentration is more suitable than the LC_(50) value for environmental monitoring using ciliates. The effects of chlorpyrifos and dimethoate on ciliate cell ultrastructures included agglutination of chromatin in the macronucleus, protruded and discontinuous macronuclear and micronuclear membranes, loss of integrity of mitochondrial membranes and contents, and abscission and deformation of the adoral zone of membranelles. 展开更多
关键词 CILIATE fission time effective concentration LC50 PESTICIDE ULTRASTRUCTURE
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A new species and new recorded species of Lumbrineridae Schmarda,1861(Annelida:Polychaeta)from China 被引量:4
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作者 蔡文倩 李新正 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第2期356-365,共10页
Based on material deposited in the Marine Biological Museum of the Chinese Academy of Sciences (Qingdao), a new species, Lurnbrineris sinensis sp. nov., as well as Augeneria albidentata (Ehlers, 1908), which is re... Based on material deposited in the Marine Biological Museum of the Chinese Academy of Sciences (Qingdao), a new species, Lurnbrineris sinensis sp. nov., as well as Augeneria albidentata (Ehlers, 1908), which is recorded for the first time from coastal water of China, are reported in the present paper. The specimens examined were collected during 1958 to 1960 from the Yellow Sea, East China Sea and South China Sea at depths of 4 to 182 m. 展开更多
关键词 POLYCHAETA Lumbrineridae Lumbrineris sinensis sp. nov. Augeneria albidentata (Ehlers 1908) new species new record Chinese waters
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DYNAMIC LAYOUT ADJUSTMENT AND NAVIGATION FOR ENTERPRISE GIS BASED ON OBJECT MARK RECOGNITION
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作者 LAIWei YUDong-gang ZHONGYong-liang 《Chinese Geographical Science》 SCIE CSCD 2003年第1期73-78,共6页
In this paper a new method is developed to make a dynamic layout adjustmentand navigation for enterprise Geographic Information System (GIS) based on object mark recognition.The extraction of object mark images is bas... In this paper a new method is developed to make a dynamic layout adjustmentand navigation for enterprise Geographic Information System (GIS) based on object mark recognition.The extraction of object mark images is based on some morphological structural patterns, which aredescribed by morphological structural points, contour property, and other geometrical data in abinary image of enterprise geographic information map. Some pre-processing methods, contour smoothfollowing, linearization and extraction patterns of structural points, are introduced. If anyspecial object is selected to make a decision in a GIS map, the all information around it will beobtained. That is, we need to investigate similar object enterprises around selected region toanalyse whether it is necessary for establishing the object enterprise at that place. To furthernavigate GIS map, we need to move from one region to another. Each time a region is formed anddisplayed based on the user's focus. If a focus point of a map is selected, in terms of extractedobject mark image, a dynamic layout and navigation diagram is constructed. When the user changes thefocus (i. e. click a node in the navigation mode), a new sub-diagram is formed by dropping oldnodes and adding new nodes. The prototype system provides effective interfaces that support GISimage navigation, detailed local image/map viewing, and enterprise information browsing. 展开更多
关键词 layout NAVIGATION geographic information system shape description andrecognition image processing
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Construction of a Normalized Full-Length cDNA Library of Cephalopod Amphioctopus fangsiao and Development of Microsatellite Markers 被引量:1
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作者 FENG Yanwei LIU Wenfen +5 位作者 XU Xin YANG Jianmin WANG Weijun WEI Xiumei LIU Xiangquan SUN Guohua 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第5期897-904,共8页
Amphioctopus fangsiao is one of the most economically important species and has been considered to be a candidate for aquaculture. In order to facilitate its fine-scale genetic analyses, we constructed a normalized fu... Amphioctopus fangsiao is one of the most economically important species and has been considered to be a candidate for aquaculture. In order to facilitate its fine-scale genetic analyses, we constructed a normalized full-length library successfully and developed a set of microsatellite markers in this study. The normalized full-length library had a storage capacity of 6.9×105 independent clones. The recombination efficiency was 95% and the average size of inserted fragments was longer than 1000 bp. A total of 3440 high quality ESTs were obtained, which were assembled into 1803 unigenes. Of these unigenes, 450(25%) were assigned into 33 Gene Ontology terms, 576(31.9%) into 153 Kyoto Encyclopedia of Genes and Genomes pathways, and 275(15.3%) into 22 Clusters of Orthologous Groups. Seventy-six polymorphic microsatellite markers were identified. The number of alleles per locus ranged from 4 to 17, and the observed and expected heterozygosities varied between 0.167 and 0.967 and between 0.326 and 0.944, respectively. Twelve loci were significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction and no linkage disequilibrium was found between different loci. This study provided not only a useful resource for the isolation of the functional genes, but also a set of informative microsatellites for the assessment of population structure and conservation genetics of A. fangsiao. 展开更多
关键词 microsatellite ESTs polymorphic informative normalized length alleles isolation aquaculture linkage
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Automatic Spike Sorting Based on Robust Clustering
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作者 丁伟东 袁景淇 《Journal of Donghua University(English Edition)》 EI CAS 2008年第3期273-276,共4页
The collected spikes from extracellular recordings usually contain noisy data and outliers, which make it difficult to separate them. A method for spike sorting based on robust clustering is proposed to deal with the ... The collected spikes from extracellular recordings usually contain noisy data and outliers, which make it difficult to separate them. A method for spike sorting based on robust clustering is proposed to deal with the problem. The clustering method combines the advantage of fuzzy clustering and robust statistical estimators. The number of dusters is obtained by fuzzy cluster validity. In order to reduce the influence of outliers, the validity index is calculated using the weighting intra-cluster distances. The proposed method is suitable to separate neural spikes in the presence of noisy data and outfiers. The experiment on real data shows its performance. 展开更多
关键词 spike sorting robust clustering multiunit extracellular recording
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Insights into the phylogeny of sporadotrichid ciliates (Protozoa, Ciliophora: Hypotricha) based on genealogical analyses of multiple molecular markers
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作者 胡晓燕 胡晓钟 +2 位作者 Khaled A.S.AL-RASHEID Saleh A.AL-FARRAJ 宋微波 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第1期96-102,共7页
The sporadotrichid ciliates are an especially diverse group. A number of investigators have studied the morphological, morphogenetic, and molecular relationships among members of this group. Despite this, a consistent... The sporadotrichid ciliates are an especially diverse group. A number of investigators have studied the morphological, morphogenetic, and molecular relationships among members of this group. Despite this, a consistent classification is still lacking and several important questions about the phylogenetic relationships within this group remain unsolved. To improve our understanding of these relationships, we constructed phylogenetic trees using the nucleotide sequences of the small-subunit rRNA (SSrRNA) gene and amino acid sequences of actin I and α-tubulin. Analyses of SSrRNA gene sequences indicated that: 1) the Sporadotrichida sensu Lynn (2008) and the Oxytrichidae are polyphyletic; 2) the Uroleptus species, which are classified to urostylids, formed a sister group with the oxytrichids; 3) Halteria grandinella, which is grouped morphologically with oligotrich species, clustered within the oxytrichids. These results are congruent with previous studies based on SSrRNA gene sequences. However, the amino acid sequences of actin I and α-tubulin yielded different topologies. The main results are: 1) in all phylogenetic trees, the genus Oxytricha was paraphyletic; 2) Uroleptus was sister to a subset of Urostyla and Holosticha, albeit with low supporting values; 3) Halteria grandinella was separated distantly from the Oxytrichidae in trees inferred from actin I amino acid sequences but clustered with oligotrichids in the α-tubulin analysis. The inconsistency among the trees inferred from these different molecular markers may be caused by rapidly accumulated genetic characterizations of ciliates. Further studies with additional molecular markers and sampling of more taxa are expected to better address the relationships among sporadotrichids. 展开更多
关键词 sporadotrichid ciliates PHYLOGENY SSRRNA actin I ALPHA-TUBULIN amino acid sequences
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SMAD7 and SERPINE1 as novel dynamic network biomarkers detect and regulate the tipping point of TGF-beta induced EMT 被引量:6
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作者 Zhonglin Jiang Lina Lu +5 位作者 Yuwei Liu Si Zhang Shuxian Li Guanyu Wang Peng Wang Luonan Chen 《Science Bulletin》 SCIE EI CAS CSCD 2020年第10期842-853,M0004,共13页
Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer ... Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer metastasis. A hallmark of EMT is the switch-like behavior during state transition, which is characteristic of phase transitions. Hence, detecting the tipping point just before mesenchymal state transition is critical for understanding molecular mechanism of EMT. Through dynamic network biomarkers(DNB) model, a DNB group with 37 genes was identified which can provide the early-warning signals of EMT. Particularly, we found that two DNB genes, i.e., SMAD7 and SERPINE1 promoted EMT by switching their regulatory network which was further validated by biological experiments. Survival analyses revealed that SMAD7 and SERPINE1 as DNB genes further acted as prognostic biomarkers for lung adenocarcinoma. 展开更多
关键词 Dynamic network biomarker Tipping point Epithelial–mesenchymal transition BISTABILITY Quantitative real-time PCR
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Cold-induced shape memory hydrogels for strong and programmable artificial muscles 被引量:5
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作者 Luqin Hua Chuanzhuang Zhao +2 位作者 Xin Guan Jianlei Lu Jiawei Zhang 《Science China Materials》 SCIE EI CAS CSCD 2022年第8期2274-2280,共7页
Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we pr... Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we present a unique poly(acrylic acid)/calcium acetate shape memory hydrogel with cold-induced shape recovery performances as ultrastrong artificial muscles.Since the acetate groups could form aggregate at high temperatures and thus induce the association of the hydrogel network,the hydrogel can be fixed into a temporary shape upon heating and recover to its original shape in a cold environment.Moreover,a programmable shape recovery process is realized by adjusting the shape fixing time.In addition,the unique shape memory process enables the application demonstration as bio-inspired artificial muscles with an ultrahigh work density of45.2 kJ m^(-3),higher than that of biological muscles(~8 kJ m^(-3)). 展开更多
关键词 shape memory hydrogel THERMO-RESPONSIVE hydrophobic aggregation cold-induced shape recovery artificial muscles
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Genetic outcomes from the translocations of the critically endangered woylie
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作者 Carlo PACIONI Adrian F. WAYNE Peter B. S. SPENCER 《Current Zoology》 SCIE CAS CSCD 2013年第3期294-310,共17页
Translocations are an important conservation strategy for many species. However simply observing demographic growth of a translocated population is not sufficient to infer species recovery. Adequate genetic representa... Translocations are an important conservation strategy for many species. However simply observing demographic growth of a translocated population is not sufficient to infer species recovery. Adequate genetic representation of the source population(s) and their long-term viability should also be considered. The woylie Bettongia penicillata ogilbyi has been subject to more formal translocations for conservation than any other marsupial that, up until recently, has resulted in one of the most suc- cessful species recoveries in Australia. We used mitochondrial and nuclear DNA markers to assess the genetic outcomes of trans- located woylie populations. These populations have lost genetic variability, differentiated fxom their source population and the supplementation program on two island populations appears to have failed. We discuss the conservation implications that our re- suits have for managing threatened species, outline some general recommendations for the management of present and future translocations and discuss the appropriate sampling design for the establishment of new populations or captive breeding programs that may mitigate the genetic 'erosion' seen in our study species. This research provides some practical outcomes and a pragmatic understanding of translocation biology. The findings are directly applicable to other translocation programs . 展开更多
关键词 Bettongia penicillata MACROPOD TRANSLOCATION Supplementation Microsatellites MTDNA
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The effects of gonadal hormones on learning and memory in male mammals: A review 被引量:1
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作者 Stuart T. LEONARD Peter J. WINSAUER 《Current Zoology》 SCIE CAS CSCD 北大核心 2011年第4期543-558,共16页
The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and ... The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes including cognition, neural development, and neural plasticity. In particular, a number of studies show that estradiol modulates dendritic spine growth and synapse density (synaptic plasticity) in the hippocampus of females, and that increased estradiol levels are generally associated with improvements on a variety of learning and memory tasks. While the majority of research has focused on the beneficial effects of estradiol in females, much less attention has been given to testosterone and its effects on learning and memory in males. Similar to estradiol titers in females, testosterone titers in males decline with age, albeit more gradually, and this decline has been correlated with impairment of certain cognitive tasks. Moreover, studies involving both humans and animals indicate that testosterone and its metabolites can augment responding on certain behavioral tasks, depending on the subject's current hormonal state, the response required, and the stimuli involved (e.g., those involving spatial or nonspatial stimuli). While the exact mechanisms by which testosterone exerts its effects on learning and memory are not fully understood, recent findings suggest that testosterone modulates learning and memory in males through an interaction with the cholinergic system. The overall objective of this review is to discuss studies investigating the role of the gonadal hormones in mediating learning and memory processes in male mammals [Current Zoology 57 (4): 543-558, 2011]. 展开更多
关键词 TESTOSTERONE Learning and memory Cholinergic system MAMMALS COGNITION ANDROGENS
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Smelling fit: scent marking exposes parasitic infection status in the banded mongoose
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作者 Jessica MITCHELL Michael A. CANT +1 位作者 Emma I.K. VITIKAINEN Hazel J. NICHOLS 《Current Zoology》 SCIE CAS CSCD 2017年第3期237-247,共11页
Preference for uninfected mates is presumed beneficial as it minimizes one's risk of contracting an infection and infecting one's offspring. In avian systems, visual ornaments are often used to indi- cate parasite b... Preference for uninfected mates is presumed beneficial as it minimizes one's risk of contracting an infection and infecting one's offspring. In avian systems, visual ornaments are often used to indi- cate parasite burdens and facilitate mate choice. However, in mammals, olfactory cues have been proposed to act as a mechanism allowing potential mates to be discriminated by infection status. The effect of infection upon mammalian mate choice is mainly studied in captive rodents where ex- perimental trials support preference for the odors of uninfected mates and some data suggest scent marking is reduced in individuals with high infection burdens. Nevertheless, whether such effects occur in nonmodel and wild systems remains poorly understood. Here, we investigate the interplay between parasite load (estimated using fecal egg counts) and scent marking behavior in a wild population of banded mongooses Mungos mungo. Focusing on a costly protozoan parasite of the genus Isospora and the nematode worm Toxocara, we first show that banded mongooses that engage in frequent, intensive scent marking have lower Isospora loads, suggesting marking behavior may be an indicator trait regarding infection status. We then use odor presentations to demonstrate that banded mongooses mark less in response to odors of opposite sexed individuals with high Isospora and Toxocara loads. As both of these parasites are known to have detrimental effects upon the health of preweaned young in other species, they would appear key targets to avoid during mate choice. Results provide support for scent as an important ornament and mechanism for advertising parasitic infection within wild mammals. 展开更多
关键词 ISOSPORA OLFACTION PARASITE SCENT scent preferences Toxocara.
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A molecular dynamics investigation of the deformation mechanism and shape memory effect of epoxy shape memory polymers 被引量:3
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作者 Hua Yang Zheng Dao Wang +1 位作者 Ya Fang Guo Xing Hua Shi 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第3期89-95,共7页
Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behavi... Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behaviors of three types of epoxy SMPs with varying curing agent contents were investigated using a molecular dynamics(MD) method. The mechanical properties under uniaxial tension at different temperatures were obtained, and the simulation results compared reasonably with experimental data. In addition, in a thermomechanical cycle, ideal shape memory effects for the three types of SMPs were revealed through the shape frozen and shape recovery responses at low and high temperatures, respectively, indicating that the recovery time is strongly influenced by the ratio of E-51 to 4,4'-Methylenedianiline. 展开更多
关键词 shape memory polymer molecular dynamics simulation THERMOMECHANICS
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Dynamics of ^(14)C-labelled Glucose and NH_4^+ in a Regularly Flooded Extremely Alkaline Saline Soil
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作者 Luc DENDOOVEN Eustacio RAMIREZ-FUENTES +4 位作者 Rocio ALCANTARA-HERNDEZ Cesar VALENZUELA-ENCINAS Katia Berenice SANCHEZ-LOPEZ Marco LUNA-GUIDO Victor Manuel RUIZ-VALDIVIEZO 《Pedosphere》 SCIE CAS CSCD 2015年第2期230-239,共10页
Flooding an extremely alkaline(pH 10.6) saline soil of the former Lake Texcoco to reduce salinity will affect the soil carbon(C)and nitrogen(N) dynamics.A laboratory incubation experiment was done to investigate how d... Flooding an extremely alkaline(pH 10.6) saline soil of the former Lake Texcoco to reduce salinity will affect the soil carbon(C)and nitrogen(N) dynamics.A laboratory incubation experiment was done to investigate how decreasing soil salt content affected dynamics of C and N in an extremely alkaline saline soil.Sieved soil with electrical conductivity(EC) of 59.2 dS m^(-1) was packed in columns,and then flooded with tap water,drained freely and conditioned aerobically at 50%water holding capacity for a month.This process of flooding-drainage-conditioning was repeated eight times.The original soil and the soil that had undergone one,two,four and eight flooding-drainage-conditioning cycles were amended with 1000 mg glucose-^(14)C kg^(-1) soil and 200 mg NH_4^+-N kg^(-1)soil,and then incubated for 28 d.The CO_2 emissions,soil microbial biomass,and soil ammonium(NE_4^+),nitrite(NO_2^-) and nitrate(NO_3^-) were monitored in the aerobic incubation of 28 d.The soil EC decreased from 59.2 to 1.0 dS m^(_1) after eight floodings,and soil pH decreased from 10.6 to 9.6.Of the added ^(14)C-labelled glucose,only 8%was mineralized in the original soil,while 24%in the soil flooded eight times during the 28-d incubation.The priming effect was on average 278 mg C kg^(-1) soil after the 28-d incubation.Soil microbial biomass C(mean 66 mg C kg^(-1) soil) did not change with flooding times in the unamended soil,and increased 1.4 times in the glucose-NH_4^+-amended soil.Ammonium immobilization and NO_2^- concentration in the aerobically incubated soil decreased with increasing flooding times,while NO_3^- concentration increased.It was found that flooding the Texcoco soil decreased the EC sharply,increased mineralization of glucose,stimulated nitrification,and reduced immobilization of inorganic N,but did not affect soil microbial biomass C. 展开更多
关键词 C mineralization CO2 emission microbial biomass C mineral N NITRIFICATION
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