An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were c...An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders (Rodentia, Insectivora, Scandentia and Carnivora), while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts.展开更多
In the present study with Tan sheep, small-tailed Han sheep, Hu sheep, Tong sheep, and Wadi sheep, we detected the distribution of gene frequency of several microsatellite sites in different chromosomes, the result sh...In the present study with Tan sheep, small-tailed Han sheep, Hu sheep, Tong sheep, and Wadi sheep, we detected the distribution of gene frequency of several microsatellite sites in different chromosomes, the result showed that: 1) Hu sheep was in the status of Hardy-Weinberg extreme disequilibrium (P 〈 0.01), while populations including Tong sheep, small-tailed Han sheep, Tan sheep, and Wadi sheep were in Hardy-Weinberg equilibrium (P 〉 0.05). 2) Variance analysis of the heterozygosity and poly- morphic information content at rnicrosatellite makers showed that there were not significant differences among populations as to heterozygosity and PIC (P 〉 0.05), as to effective number of alleles there were not significant differences both among Tan sheep, Hu sheep, Tong sheep, and Wadi sheep, and between Wadi sheep and small-tailed sheep (P 〉 0.05), but between the former three populations and the latter two populations, there were significant differences (0.01〈 P 〈0.05). The variation levels of small-tailed Han sheep was the highest in the five populations based on microsatellite maker data, subsequently followed by Wadi sheep, Tong sheep, Tan sheep, and then Hu sheep. 3) The phylogenetic relationships of the five sheep populations in this study did not meet the mechanism of isolation by distance, and the genetic differentiation relationships among five sheep populations were not closely linearly correlative with their geography distribution. Our findings supported related records in literature: The five populations originated on different time stage from the primogenitor population and communicated genetically with each other thereafter in the process of natural and artificial selection and on different ecological environment.展开更多
Based on mass balance theory and IsoSource program,stable carbon and nitrogen isotopic ratios revealed that small mammals (plateau pika,root vole and plateau zokor) contributed 26.8% and 27.0% and 29.2% to alpine weas...Based on mass balance theory and IsoSource program,stable carbon and nitrogen isotopic ratios revealed that small mammals (plateau pika,root vole and plateau zokor) contributed 26.8% and 27.0% and 29.2% to alpine weasel,steppe polecat and upland buzzard of carnivores as food respectively;adult passerine birds contributed 22.3%,47.7% and 69.1%,with hatchlings contributing 50.9%,25.6% and 1.70% to each respectively.δ 13 C values plotted against δ 15 N indicated significant partitioning in two-dimensional space among the three carnivores.It was reasonable to propose a food resource partitioning among alpine weasel,steppe polecat and upland buzzard,which partially revealed their co-existence mechanisms.展开更多
Microwave-assisted extraction (MAE) of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. ...Microwave-assisted extraction (MAE) of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. It was concluded that two doses of intermittent microwave power radiation, 300 W each for 4 rain, were needed for extraction. The mass ratio of solvent to material was 8:1 and the alcohol mass fraction was 80%. The extracted liquor was then concentrated under vacuum and degreased with petroleum ether. The yield of total isofiavones was about 8.8% and the contents of tectoridin and iridin were 67.6% and 16.3% respectively. Compared with direct-heating extraction (DHE), MAE may shorten extracting duration, reduce solvent consumption, and improve yield and purity of isoflavones from Belamcanda chinensis.展开更多
Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances: kelp 901 (901, with comparatively stronger heat-resistance) and Rongcheng No. I (RC, sensitive to heat stress),...Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances: kelp 901 (901, with comparatively stronger heat-resistance) and Rongcheng No. I (RC, sensitive to heat stress), were respectively collected during October to December 2002 from Yantai and Rongcheng Sea Farm in the Shandong Peninsula of China. The contents of some biochemical materials and antioxidant capacity were analyzed under controlled laboratory conditions to identify if there is any relation between the overall antioxidant capacity and the heat-resistance in L. japonica and to understand possible mechanism of heat-resistance. Results show that: (1) the overall antioxidant capacity in healthy sporophyte of 901, such as vitamin E, polyphenol, and ascorbic acid contents and the enzymatic activity of SOD, POD, CAT, Gpx, PPO, and PAL, were not always higher than that of RC under controlled laboratory conditions, and no significance (P〉0.05) was shown in total antioxidant capacity (T-AOC) in 901 and RC. Result suggested that the difference in antioxidant capacity was not a decisive factor for different heat-resistances in L. japonica; (2) the simultaneous assay on isozymes was carried out using vertical polyacrylamide gel electrophoresis (PAGE). Considerable differences in peroxide (PRX), malate dehydrogenase (MDH), malic enzyme (ME), polyphenol oxidase (PPO) and glutamate dehydrogenase (GDH) were obtained in 901 and RC from either the band number, relative mobility (Rf), or staining intensity, and ME could be used as an indicator to distinguish healthy sporophyte of 901 and RC under controlled laboratory conditions.展开更多
In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam (Ruditapes philippinarum), crosses between two full-sib families including self and reciprocal cross...In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam (Ruditapes philippinarum), crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B (Hp varied between 10.41% and 68.27%) displayed larger heterosis than ♂A×♀B (Hp varied between 1.89% and 32.33%) did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability (GCA), special combining ability (SCA) and interaction (I) were significant in shell length (P〈 0.05), indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.展开更多
To investigate the tissue-specificities of isozymes and the genetic structureof wild spotted halibut ( Verasper variegatus) population, horizontal starch gel electrophoresiswas performed on 45 individuals collected in...To investigate the tissue-specificities of isozymes and the genetic structureof wild spotted halibut ( Verasper variegatus) population, horizontal starch gel electrophoresiswas performed on 45 individuals collected in part of the Yellow Sea. The performances of 17 isozymesin 8 kinds of tissues or organs were screened preliminarily in a TC-7.0 buffer system. The resultsshowed that the screened isozymes displayed remarkable tissue-specificities. Finally, 14 enzymes(AAT, ADH, EST, OPI, G3PDH, IDHP, LAP, LDH, MDH, MPI, PGDH, PGM, SDH and SOD) and 4 kinds of tissues(eye, skeleton muscle, liver and heart) were selected for genetic analysis. Fourteen isozymes areencoded by 20 loci, and 9 of them are polymorphic. The polymorphic loci are AAT-1~*, GPI-2~*,G3PDH~*, IDHP-1~*, LDH~*, MPI~*, PGM-1~*. PGM-2~* and SDH~*, and the proportion of polymorphic lociis 0.4500 (P_(0.99)) ? The mean values of observed and expected heterozygosities are 0.0278and 0.0265, respectively and the average effective number of alleles is 1.0675.展开更多
In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwav...In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.展开更多
The effects of salinity (50 mmol/L NaCI) and Cd (1 μmol/L CdCl2) as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of C...The effects of salinity (50 mmol/L NaCI) and Cd (1 μmol/L CdCl2) as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2+, Zn^2+, Ca^2+, Mg^2+, K^+ and Na^+were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate (P,) in the treatments of salinity stress alone and combined stress (NaCl+Cd), showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency (the ratio of variable fluorescence to maximal fluorescence, Fv/Fm), whereas the decease in NGB was mainly related to reduced stomatal conductance (Gs), The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2+, Ca^2+, Mg^2+, K^+ and Na^+was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.展开更多
A total of 19 protected areas (PAs) have been established in Bangladesh representing all the four forest types of the country. Apart from being the repository of biological diversity, these PAs serve as the source o...A total of 19 protected areas (PAs) have been established in Bangladesh representing all the four forest types of the country. Apart from being the repository of biological diversity, these PAs serve as the source of subsistence livelihoods to the local communities. While all the PAs are managed by the state Forest Department (FD), with a view to ensure sustainability, a recent approach of co-management has been initiated in five PAs as a pilot project with an aid of development partners incorporating stakeholders' participation. Along with demonstrating a number of upbeat impacts, the initiatives exert some constraints which need to be addressed properly to ensure the success of participatory approach and enhance the ongoing conservation scheme. This paper reviews the published works, government and project documents to analyze the present status of PAs and suggest recommendations accordingly.展开更多
Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral com...Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral complex solvent extraction system, fatty alcohol-kerosene (marked by El), was used for extraction of erythromycin, one of the macrolide antibiotics. The extraction equilibrium equation is obtained, and the extraction distribution is as followsD = exp (-36.33×103/RT + 18.77)[B](o)1.1/(1 + 108.07-PH)The effects of several parameters on extraction equilibrium were investigated. Furthermore, a new synergistic extraction system (marked by E2) was developed, in which another solvent was used as synergistic agent to replace the diluent kerosene in the neutral complex extraction system. Based on these new extraction systems, an improved process for extraction of erythromycin was developed, showing remarkable advantages in technology and economics owing to its low solvent consumption of 3kg per billion unit compared with 9—10 for butylacetate. The recovery process of solvent from raffinate may be eliminated.展开更多
Abstract In this study, the method of divergent selection was employed to test the larval and juvenile growth performance within a full-sib family of Manila clam Ruditapes philippinarum. The 10% largest and 10% smalle...Abstract In this study, the method of divergent selection was employed to test the larval and juvenile growth performance within a full-sib family of Manila clam Ruditapes philippinarum. The 10% largest and 10% smallest clam individuals (on the basis of shell length) of a full-sib family were selected as parents for the fast and slow growing lines, respectively. The difference in shell length was significant among the three lines (fast, control, and slow) tested. The sequence of shell length were fast line 〉 control line 〉 slow line. The responses to selection, realized heritability, and genetic gain were 0.06%-0.81%, 0.04%-0.47% and 0.58%-18.89% in the fast direction, respectively; and were 0.14%-1.27%, 0.08%-0.73%, and 0.31%-49.03% in the slow direction, respectively. The re- suits suggested that there was a large portion of additive genetic variance affecting the growth in the full-sib family. Selection in the fast direction within the full-sib family would greatly improve the growth ofR. philippinarum.展开更多
To reveal the mechanism of control of the Woolly Apple Aphid (Eriosoma lanigerum Hausm, WAA) by increase of biodiversity in the apple orchard, a consecutive two-year field trials were conducted in Yurman province, C...To reveal the mechanism of control of the Woolly Apple Aphid (Eriosoma lanigerum Hausm, WAA) by increase of biodiversity in the apple orchard, a consecutive two-year field trials were conducted in Yurman province, China. The results showed that the peak of natural enemy density curve in the cover cropping orchard was well temporally synchronized with that of the WAA density on trees, but did not synchronize with that of WAA density on trees in clean orchard. In addition, the frequency of natural enemies and WAA within a same sample in cover cropping orchard was obviously higher than that in clean cultivated orchard during the peak of population curves, indicating that natural enemies spatially synchronized with aphids. The density of WAA for the whole growing season in cover cropping orchard was much less than that in clean orchard. Therefore, the temporal-spatial synchrony of natural enemy and aphid populations was proposed as one of the mechanisms for aphid control in cover cropped orchards.展开更多
This paper describes parody as an effective teaching and learning practice in Advanced English course offered to English major juniors and seniors. The objective of this course is to help heighten students towards a m...This paper describes parody as an effective teaching and learning practice in Advanced English course offered to English major juniors and seniors. The objective of this course is to help heighten students towards a more advanced level of English proficiency, and its main preoccupation is doing intensive analyses of carefully selected texts which amount to well-established classics and are characterized with linguistic complexity. To enhance students' learning, we embed in the course a practice of parody, which here refers to the creation of an imitative work of an original written work, usually with an attendant comic effect. Upon the completion of each module, students are assigned the task of parodying part of the text, which involves recasting its overall content while retaining formal framework, thus offering students a means of re-paying homage to the excellence of the text. Writing a parody demands great artistry in shaping a creatively simulative work, in fitting exotic content into a local form, and in transplanting new experiential logic into old textual order. The parodies are then peer-reviewed as well as instructor-reviewed. Close observation and survey show that the students have displayed heightened motivation in engaging themselves in the practice and they have benefited greatly from it. Parody proves a particularly fruitful technique in teaching and learning Advanced English, and may also be useful in teaching English writing, since it entitles students to a very unique mode of savoring and wielding the artistic power of the English language.展开更多
The 2030 Agenda for Sustainable Development outlines 17 individual Sustainable Development Goals (SDGs) that guide the needs of practice for many professional disciplines around the world, including engineering, res...The 2030 Agenda for Sustainable Development outlines 17 individual Sustainable Development Goals (SDGs) that guide the needs of practice for many professional disciplines around the world, including engineering, research, policy, and development. The SDGs represent commitments to reduce poverty, hunger, ill health, gender inequality, environmental degradation, and lack of access to clean water and sanitation. If a typical reductionist approach is employed to address and optimize individual goals, it may lead to a failure in technological, policy, or managerial development interventions through unin- tended consequences in other goals. This study uses a systems approach to understand the fundamental dynamics between the SDGs in order to identify potential synergies and antagonisms. A conceptual system model was constructed to illustrate the causal relationships between SDGs, examine system structures using generic system archetypes, and identify leverage points to effectively influence intentional and minimize unintentional changes in the system. The structure of interactions among the SDGs reflects three archetypes of system behavior: Reinforcing Growth, Limits to Growth, and Growth and Underinvestment. The leverage points identified from the conceptual model are gender equality, sustainable management of water and sanitation, alternative resources, sustainable livelihood standards, and global partnerships. Such a conceptual system analysis of SDGs can enhance the likelihood that the development community will broaden its understanding of the potential synergistic benefits of their projects on resource management, environmental sustainability, and climate change. By linking the interactions and feedbacks of those projects with economic gains, women's empowerment, and educational equality, stakeholders can recognize holistic improvements that can be made to the quality of life of many of the world's poor.展开更多
The authors have proposed a new of magnetic isotope theory of life on Earth. According to this theory the initial impetus for the beginning of the synthesis of organic compounds is the impact of electromagnetic radiat...The authors have proposed a new of magnetic isotope theory of life on Earth. According to this theory the initial impetus for the beginning of the synthesis of organic compounds is the impact of electromagnetic radiation from the sun and energy radioactive isotopes.展开更多
Multiphoton microscopy, relying on the simultaneous absorption of two or more photons by a fluorophore, has come to occupy a prominent place in modern biomedical research with its ability to allow real-time observatio...Multiphoton microscopy, relying on the simultaneous absorption of two or more photons by a fluorophore, has come to occupy a prominent place in modern biomedical research with its ability to allow real-time observation of a single cell and molecules in intact tissues. Multiphoton microscopy exhibits nonlinear optical contrast properties, which can make it possible to provide an exceptionally large depth penetration with less phototoxicity. This system becomes more and more an inspiring tool for a non-invasive imaging system to realize "optical biopsy" and to examine the functions of living cells. In this review, we briefly present the physical principles and properties of multiphoton microscopy as well as the current applications in biological fields. In addition, we address what we see as the future potential of multiphoton microscopy for gastroenterologic research.展开更多
The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, espe- cially the hormone-related differences in maturing male fish has seldom been documented. In this ...The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, espe- cially the hormone-related differences in maturing male fish has seldom been documented. In this study, a full length cDNA sequence of the vasa gene was cloned from Japanese sea bass, Lateolabraxjaponicas, and it was namedjsb-vasa. Homology analysis showed thatjsb-vasa was closely related to its teleost homologs. The spatial distribution ofjsb-vasa indicated that it was only highly ex- pressed in testis, showing its germ cell-specific expression pattern. During the testicular development cycle, jsb-vasa was highly expressed during early period of spermatogenesis, and reduced when spermatogenesis advanced. In addition, the jsb-vasa gene ex- pression was significantly inhibited at 6 h, 12 h and 24 h after injecting hCG (human ehorionic gonadotropin) and GnRHa (Gonad- otropin-releasing hormone analogue), indicating thatjsb-vasa gene may play an important role in spermatogenesis of Japanese sea bass, and be under the regulation of external sex hormones.展开更多
In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase o...In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase of the seeds production, it is necessary to ensure that there is no leakage of the radioactive material. A leakage test is performed, immersing the seeds in water during 24 h and measuring the resulting activity in the water. This measurement is made in a sodium iodide detector. The immersion water is transferred to a plastic tube with a cap. The tube is placed by an automated positioning system, in the detector chamber. This study aims to determine the best positioning of the tube for the detection. It is also important to determine the influence of the positioning variation intrinsic of the automated positioning system during the iodine-125 seeds production. The results obtained will be used as a reference to adjust the equipment and process control system, in the production of the iodine-125 seeds.展开更多
基金This project was supported by the Natural Science Foundation of China(30460125)
文摘An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders (Rodentia, Insectivora, Scandentia and Carnivora), while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts.
基金This work was supported by the International Cooperation Item of the National Natural Science Foundation of China (No. 30213009, 30310103007, 30410103150)Natural Science Foundation of Jiangsu Province of China (No. BK2007556)+1 种基金Basic Natura Science Foundation for Colleges and Universities Jiangsu Province (No. NK051039, 06KJD230203)the New Century Talent Project of Yangzhou University in China.
文摘In the present study with Tan sheep, small-tailed Han sheep, Hu sheep, Tong sheep, and Wadi sheep, we detected the distribution of gene frequency of several microsatellite sites in different chromosomes, the result showed that: 1) Hu sheep was in the status of Hardy-Weinberg extreme disequilibrium (P 〈 0.01), while populations including Tong sheep, small-tailed Han sheep, Tan sheep, and Wadi sheep were in Hardy-Weinberg equilibrium (P 〉 0.05). 2) Variance analysis of the heterozygosity and poly- morphic information content at rnicrosatellite makers showed that there were not significant differences among populations as to heterozygosity and PIC (P 〉 0.05), as to effective number of alleles there were not significant differences both among Tan sheep, Hu sheep, Tong sheep, and Wadi sheep, and between Wadi sheep and small-tailed sheep (P 〉 0.05), but between the former three populations and the latter two populations, there were significant differences (0.01〈 P 〈0.05). The variation levels of small-tailed Han sheep was the highest in the five populations based on microsatellite maker data, subsequently followed by Wadi sheep, Tong sheep, Tan sheep, and then Hu sheep. 3) The phylogenetic relationships of the five sheep populations in this study did not meet the mechanism of isolation by distance, and the genetic differentiation relationships among five sheep populations were not closely linearly correlative with their geography distribution. Our findings supported related records in literature: The five populations originated on different time stage from the primogenitor population and communicated genetically with each other thereafter in the process of natural and artificial selection and on different ecological environment.
文摘Based on mass balance theory and IsoSource program,stable carbon and nitrogen isotopic ratios revealed that small mammals (plateau pika,root vole and plateau zokor) contributed 26.8% and 27.0% and 29.2% to alpine weasel,steppe polecat and upland buzzard of carnivores as food respectively;adult passerine birds contributed 22.3%,47.7% and 69.1%,with hatchlings contributing 50.9%,25.6% and 1.70% to each respectively.δ 13 C values plotted against δ 15 N indicated significant partitioning in two-dimensional space among the three carnivores.It was reasonable to propose a food resource partitioning among alpine weasel,steppe polecat and upland buzzard,which partially revealed their co-existence mechanisms.
文摘Microwave-assisted extraction (MAE) of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. It was concluded that two doses of intermittent microwave power radiation, 300 W each for 4 rain, were needed for extraction. The mass ratio of solvent to material was 8:1 and the alcohol mass fraction was 80%. The extracted liquor was then concentrated under vacuum and degreased with petroleum ether. The yield of total isofiavones was about 8.8% and the contents of tectoridin and iridin were 67.6% and 16.3% respectively. Compared with direct-heating extraction (DHE), MAE may shorten extracting duration, reduce solvent consumption, and improve yield and purity of isoflavones from Belamcanda chinensis.
基金Supported by the National Hi-Tech Research Program (863 Program, No. 2004AA639770)the National Natural Science Foundation of China (No.30270258)Program for New Century Excellent Talents in University (NCET-05-0597).
文摘Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances: kelp 901 (901, with comparatively stronger heat-resistance) and Rongcheng No. I (RC, sensitive to heat stress), were respectively collected during October to December 2002 from Yantai and Rongcheng Sea Farm in the Shandong Peninsula of China. The contents of some biochemical materials and antioxidant capacity were analyzed under controlled laboratory conditions to identify if there is any relation between the overall antioxidant capacity and the heat-resistance in L. japonica and to understand possible mechanism of heat-resistance. Results show that: (1) the overall antioxidant capacity in healthy sporophyte of 901, such as vitamin E, polyphenol, and ascorbic acid contents and the enzymatic activity of SOD, POD, CAT, Gpx, PPO, and PAL, were not always higher than that of RC under controlled laboratory conditions, and no significance (P〉0.05) was shown in total antioxidant capacity (T-AOC) in 901 and RC. Result suggested that the difference in antioxidant capacity was not a decisive factor for different heat-resistances in L. japonica; (2) the simultaneous assay on isozymes was carried out using vertical polyacrylamide gel electrophoresis (PAGE). Considerable differences in peroxide (PRX), malate dehydrogenase (MDH), malic enzyme (ME), polyphenol oxidase (PPO) and glutamate dehydrogenase (GDH) were obtained in 901 and RC from either the band number, relative mobility (Rf), or staining intensity, and ME could be used as an indicator to distinguish healthy sporophyte of 901 and RC under controlled laboratory conditions.
基金supported by the earmarked fund for Modern Agro-industry Technology Research System (CARS-48)grants from the ‘863’ Project of China (2012AA10AA400)
文摘In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam (Ruditapes philippinarum), crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B (Hp varied between 10.41% and 68.27%) displayed larger heterosis than ♂A×♀B (Hp varied between 1.89% and 32.33%) did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability (GCA), special combining ability (SCA) and interaction (I) were significant in shell length (P〈 0.05), indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.
文摘To investigate the tissue-specificities of isozymes and the genetic structureof wild spotted halibut ( Verasper variegatus) population, horizontal starch gel electrophoresiswas performed on 45 individuals collected in part of the Yellow Sea. The performances of 17 isozymesin 8 kinds of tissues or organs were screened preliminarily in a TC-7.0 buffer system. The resultsshowed that the screened isozymes displayed remarkable tissue-specificities. Finally, 14 enzymes(AAT, ADH, EST, OPI, G3PDH, IDHP, LAP, LDH, MDH, MPI, PGDH, PGM, SDH and SOD) and 4 kinds of tissues(eye, skeleton muscle, liver and heart) were selected for genetic analysis. Fourteen isozymes areencoded by 20 loci, and 9 of them are polymorphic. The polymorphic loci are AAT-1~*, GPI-2~*,G3PDH~*, IDHP-1~*, LDH~*, MPI~*, PGM-1~*. PGM-2~* and SDH~*, and the proportion of polymorphic lociis 0.4500 (P_(0.99)) ? The mean values of observed and expected heterozygosities are 0.0278and 0.0265, respectively and the average effective number of alleles is 1.0675.
基金Projects(51176045,51276056)supported by the National Natural Science Foundation of ChinaProject(531105050037)supported by the Changjiang Scholars and Innovative Research Team in University,ChinaProjects(201208430262,201306130031)supported by the National Studying Abroad Foundation Project of China
文摘In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.
基金Project (No. Z304104) supported by Natural Science Foundation of Zhejiang Province, China
文摘The effects of salinity (50 mmol/L NaCI) and Cd (1 μmol/L CdCl2) as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2+, Zn^2+, Ca^2+, Mg^2+, K^+ and Na^+were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate (P,) in the treatments of salinity stress alone and combined stress (NaCl+Cd), showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency (the ratio of variable fluorescence to maximal fluorescence, Fv/Fm), whereas the decease in NGB was mainly related to reduced stomatal conductance (Gs), The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2+, Ca^2+, Mg^2+, K^+ and Na^+was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.
文摘A total of 19 protected areas (PAs) have been established in Bangladesh representing all the four forest types of the country. Apart from being the repository of biological diversity, these PAs serve as the source of subsistence livelihoods to the local communities. While all the PAs are managed by the state Forest Department (FD), with a view to ensure sustainability, a recent approach of co-management has been initiated in five PAs as a pilot project with an aid of development partners incorporating stakeholders' participation. Along with demonstrating a number of upbeat impacts, the initiatives exert some constraints which need to be addressed properly to ensure the success of participatory approach and enhance the ongoing conservation scheme. This paper reviews the published works, government and project documents to analyze the present status of PAs and suggest recommendations accordingly.
文摘Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral complex solvent extraction system, fatty alcohol-kerosene (marked by El), was used for extraction of erythromycin, one of the macrolide antibiotics. The extraction equilibrium equation is obtained, and the extraction distribution is as followsD = exp (-36.33×103/RT + 18.77)[B](o)1.1/(1 + 108.07-PH)The effects of several parameters on extraction equilibrium were investigated. Furthermore, a new synergistic extraction system (marked by E2) was developed, in which another solvent was used as synergistic agent to replace the diluent kerosene in the neutral complex extraction system. Based on these new extraction systems, an improved process for extraction of erythromycin was developed, showing remarkable advantages in technology and economics owing to its low solvent consumption of 3kg per billion unit compared with 9—10 for butylacetate. The recovery process of solvent from raffinate may be eliminated.
基金supported by the grant from the Natural National Science Foundation of China (No.31502163)the fund earmarked for Modern Agro-industry Technology Research System (CARS-48)the Natural Science Foundation Grant of Tianjin (No.15JCYBJC30400)
文摘Abstract In this study, the method of divergent selection was employed to test the larval and juvenile growth performance within a full-sib family of Manila clam Ruditapes philippinarum. The 10% largest and 10% smallest clam individuals (on the basis of shell length) of a full-sib family were selected as parents for the fast and slow growing lines, respectively. The difference in shell length was significant among the three lines (fast, control, and slow) tested. The sequence of shell length were fast line 〉 control line 〉 slow line. The responses to selection, realized heritability, and genetic gain were 0.06%-0.81%, 0.04%-0.47% and 0.58%-18.89% in the fast direction, respectively; and were 0.14%-1.27%, 0.08%-0.73%, and 0.31%-49.03% in the slow direction, respectively. The re- suits suggested that there was a large portion of additive genetic variance affecting the growth in the full-sib family. Selection in the fast direction within the full-sib family would greatly improve the growth ofR. philippinarum.
文摘To reveal the mechanism of control of the Woolly Apple Aphid (Eriosoma lanigerum Hausm, WAA) by increase of biodiversity in the apple orchard, a consecutive two-year field trials were conducted in Yurman province, China. The results showed that the peak of natural enemy density curve in the cover cropping orchard was well temporally synchronized with that of the WAA density on trees, but did not synchronize with that of WAA density on trees in clean orchard. In addition, the frequency of natural enemies and WAA within a same sample in cover cropping orchard was obviously higher than that in clean cultivated orchard during the peak of population curves, indicating that natural enemies spatially synchronized with aphids. The density of WAA for the whole growing season in cover cropping orchard was much less than that in clean orchard. Therefore, the temporal-spatial synchrony of natural enemy and aphid populations was proposed as one of the mechanisms for aphid control in cover cropped orchards.
文摘This paper describes parody as an effective teaching and learning practice in Advanced English course offered to English major juniors and seniors. The objective of this course is to help heighten students towards a more advanced level of English proficiency, and its main preoccupation is doing intensive analyses of carefully selected texts which amount to well-established classics and are characterized with linguistic complexity. To enhance students' learning, we embed in the course a practice of parody, which here refers to the creation of an imitative work of an original written work, usually with an attendant comic effect. Upon the completion of each module, students are assigned the task of parodying part of the text, which involves recasting its overall content while retaining formal framework, thus offering students a means of re-paying homage to the excellence of the text. Writing a parody demands great artistry in shaping a creatively simulative work, in fitting exotic content into a local form, and in transplanting new experiential logic into old textual order. The parodies are then peer-reviewed as well as instructor-reviewed. Close observation and survey show that the students have displayed heightened motivation in engaging themselves in the practice and they have benefited greatly from it. Parody proves a particularly fruitful technique in teaching and learning Advanced English, and may also be useful in teaching English writing, since it entitles students to a very unique mode of savoring and wielding the artistic power of the English language.
基金This material is based upon work supported by the National Science Foundation (1243510).
文摘The 2030 Agenda for Sustainable Development outlines 17 individual Sustainable Development Goals (SDGs) that guide the needs of practice for many professional disciplines around the world, including engineering, research, policy, and development. The SDGs represent commitments to reduce poverty, hunger, ill health, gender inequality, environmental degradation, and lack of access to clean water and sanitation. If a typical reductionist approach is employed to address and optimize individual goals, it may lead to a failure in technological, policy, or managerial development interventions through unin- tended consequences in other goals. This study uses a systems approach to understand the fundamental dynamics between the SDGs in order to identify potential synergies and antagonisms. A conceptual system model was constructed to illustrate the causal relationships between SDGs, examine system structures using generic system archetypes, and identify leverage points to effectively influence intentional and minimize unintentional changes in the system. The structure of interactions among the SDGs reflects three archetypes of system behavior: Reinforcing Growth, Limits to Growth, and Growth and Underinvestment. The leverage points identified from the conceptual model are gender equality, sustainable management of water and sanitation, alternative resources, sustainable livelihood standards, and global partnerships. Such a conceptual system analysis of SDGs can enhance the likelihood that the development community will broaden its understanding of the potential synergistic benefits of their projects on resource management, environmental sustainability, and climate change. By linking the interactions and feedbacks of those projects with economic gains, women's empowerment, and educational equality, stakeholders can recognize holistic improvements that can be made to the quality of life of many of the world's poor.
文摘The authors have proposed a new of magnetic isotope theory of life on Earth. According to this theory the initial impetus for the beginning of the synthesis of organic compounds is the impact of electromagnetic radiation from the sun and energy radioactive isotopes.
文摘Multiphoton microscopy, relying on the simultaneous absorption of two or more photons by a fluorophore, has come to occupy a prominent place in modern biomedical research with its ability to allow real-time observation of a single cell and molecules in intact tissues. Multiphoton microscopy exhibits nonlinear optical contrast properties, which can make it possible to provide an exceptionally large depth penetration with less phototoxicity. This system becomes more and more an inspiring tool for a non-invasive imaging system to realize "optical biopsy" and to examine the functions of living cells. In this review, we briefly present the physical principles and properties of multiphoton microscopy as well as the current applications in biological fields. In addition, we address what we see as the future potential of multiphoton microscopy for gastroenterologic research.
基金supported by the National Key Technologies R&D Program of China(2011BAD13B03)
文摘The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, espe- cially the hormone-related differences in maturing male fish has seldom been documented. In this study, a full length cDNA sequence of the vasa gene was cloned from Japanese sea bass, Lateolabraxjaponicas, and it was namedjsb-vasa. Homology analysis showed thatjsb-vasa was closely related to its teleost homologs. The spatial distribution ofjsb-vasa indicated that it was only highly ex- pressed in testis, showing its germ cell-specific expression pattern. During the testicular development cycle, jsb-vasa was highly expressed during early period of spermatogenesis, and reduced when spermatogenesis advanced. In addition, the jsb-vasa gene ex- pression was significantly inhibited at 6 h, 12 h and 24 h after injecting hCG (human ehorionic gonadotropin) and GnRHa (Gonad- otropin-releasing hormone analogue), indicating thatjsb-vasa gene may play an important role in spermatogenesis of Japanese sea bass, and be under the regulation of external sex hormones.
文摘In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase of the seeds production, it is necessary to ensure that there is no leakage of the radioactive material. A leakage test is performed, immersing the seeds in water during 24 h and measuring the resulting activity in the water. This measurement is made in a sodium iodide detector. The immersion water is transferred to a plastic tube with a cap. The tube is placed by an automated positioning system, in the detector chamber. This study aims to determine the best positioning of the tube for the detection. It is also important to determine the influence of the positioning variation intrinsic of the automated positioning system during the iodine-125 seeds production. The results obtained will be used as a reference to adjust the equipment and process control system, in the production of the iodine-125 seeds.