995 resultados para Discovery (Law)
Resumo:
A total of 10446 expressed sequence tags (ESTs) are obtained by a large-scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis. An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.
Resumo:
The chlorophyll fluorescence kinetics of marine red alga Grateloupia turutunt Yamada, green alga Ulva pertusa Kjellm and brown alga Laminaria japonica Aresch during natural sustained dehydration were monitored and investigated. The pulse amplified modulation (PAM) system was used to analyze the distinct fluorescence parameters during thallus dehydration. Results proved that the fluorescence kinetics of different seaweed all showed three patterns of transformation with sustained water loss. These were: 1) peak kinetic pattern (at the early stage of dehydration fluorescence enhanced and quenched subsequently, representing a normal physiological state). 2) plateau kinetic pattern (with sustained water loss fluorescence enhanced continuously but quenching became slower, finally reaching its maximum). 3) Platform kinetic pattern (fluorescence fell and the shape of kinetic curve was similar to plateau kinetic pattern). A critical water content (CWC) could be found and defined as the percentage of water content just prior to the fluorescence drop and to be a significant physiological index for evaluation of plant drought tolerance. Once thallus water content became lower than this value the normal peak pattern can not be recovered even through rehydration, indicating an irreversible damage to the thylakoid membrane. The CWC value corresponding to different marine species were varied and negatively correlated with their desiccation tolerance, for example. Laminaria japonica had the highest CWC value (around 90%) and the lowest dehydration tolerance of the three. In addition, a fluorescence "burst" was found only in red algae during rehydration. The different fluorescence parameters F-o, F-v and F-v, F-m were measured and compared during water loss. Both F-o and F-v increased in the first stage of dehydration but F-v/F-m. kept almost constant. So the immediate response of in vivo chlorophyll fluorescence to dehydration was an enhancement. Later with sustained dehydration F-o increased continuously while F-v decreased and tended to become smaller and smaller. The major changes in fluorescence (including fluorescence drop during dehydration and the burst during rehydration) were all attributed to the change in F-o instead of F-v This significance of F-o indicates that it is necessary to do more research on F-o as well as on its relationship with the state of thylakoid membrane.
Resumo:
Crustacean haemocytes play important roles in the host immune response including recognition, phagocytosis, melanization, cytotoxicity and inter-cellular signal communication. Expressed sequence tags (ESTs) analysis is proved to be an efficient approach not only for gene discovery, but also for gene expression profiles performance. In order to further understand the innate immune system and defense mechanisms of Chinese shrimp at molecular level, complementary DNA library is constructed from the haemocyte tissue of Fenneropenaeus chinensis. A total of 2371 cDNA clones are successfully sequenced and the average sequence length is 460 bp. About 50% are identified as orthologs of known genes from other organisms by BLASTx and BLASTn program. By sequences comparability and analysis, 34 important genes including 177 ESTs are identified that may be involved in defense or immune functions in shrimp based on the known knowledge. These genes are categorized into five categories according to their putative functions in shrimp immune system: 13 genes are different types of antimicrobial peptides (AMP, penaeidin, antilipopolysaccharide factor, etc.), and their proportion is about 3 8%; 11 genes belong to prophenoloxidase system (prophenoloxidase, serine proteinase, serine proteinase inhibitor, etc.), and their proportion is about 32%; five genes have high homology with clotting protein (lectin, transglutaminase, etc), and their proportion is about 15%; three genes may be involved in inter-cell signal communication (peroxinectin, integrin), and their proportion is about 9%; two genes have been identified to be chaperone proteins (Hsc70, thioredoxin peroxidase), and their proportion is about 6%. These EST sequences enrich our understanding of the immune genes of F chinensis and will help farther experimental research into immune factors and improve our knowledge of the immune mechanisms of shrimp. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
We used microarray technology to study differentially expressed genes in white spot syndrome virus (WSSV)-infected shrimp. A total of 3136 cDNA targets, including 1578 unique genes from a cephalothorax cDNA library and 1536 cDNA clones from reverse and forward suppression subtractive hybridization (SSH) libraries of Fenneropenaeus chinensis, plus 14 negative and 8 blank control clones, were spotted onto a 18 x 18 mm area of NH2-modified glass slides. Gene expression patterns in the cephalothorax of shrimp at 6 h after WSSV injection and moribund shrimp naturally infected by WSSV were analyzed. A total of 105 elements on the arrays showed a similar regulation pattern in artificially infected shrimp and naturally infected moribund shrimp; parts of the results were confirmed by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The up-regulated expression of immune-related genes, including heat shock proteins (HSP70 and HSP90), trehalose-phosphate synthase (TPS), ubiquitin C, and so forth, were observed when shrimp were challenged with WSSV. Genes including myosin LC2, ATP synthase A chain, and arginine kinase were found to be down-regulated after WSSV infection. The expression of housekeeping genes such as actin, elongation factor, and tubulin is not stable, and so these genes are not suitable as internal standards for semiquantitative RT-PCR when shrimp are challenged by WSSV. As a substitute, we found that triosephosphate isomerase (TPI) was an ideal candidate of interstandards in this situation.
Resumo:
The Lhasa terrane, located between the Bangonghu-Nujiang suture zone and the Indus-Yalung Tsangpo suture zone in the southern Tibetan Plateau, was considered previously as a Precambrian continental block. Mesozoic and Cenozoic tectonic evolution of the Lhasa terrane is closely related to the subduction of the Tethys ocean and the collision between the Indian and European continents; so it is one of the keys to reveal the formation and evolution of the Tibetan plateau. The garnet two-pyroxene granulite which was found at the Nyingtri rock group of the southeastern Lhasa terrene consists of garnet, clinopyroxene, orthopyroxene, labradorite, Ti-rich amphibolite and biotite, with a chemical composition of mafic rock. The metamorphic conditions were estimated to be at T = 747 similar to 834 degrees C and P = 0.90 similar to 1.35GPa, suggesting a formation depth of 45km. The zircon U-Pb dating for the garnet amphibolite and marble associated with the granulite give a metamorphic age of 85 similar to 90Ma. This granulite-facies metamorphic event together with a contemporaneous magmatism demonstrated that the southern Lhasa terrane has undergone an Andean-type orogeny at Late Mesozoic time.
Resumo:
The dielectric response of graded composites having general power-law-graded cylindrical inclusions under a uniform applied electric field is investigated. The dielectric profile of the cylindrical inclusions is modeled by the equation epsilon(i)(r)=c(b+r)(k) (where r is the radius of the cylindrical inclusions and c, b and k are parameters). Analytical solutions for the local electrical potentials are derived in terms of hypergeometric functions and the effective dielectric response of the graded composites is predicted in the dilute limit. Moreover, for a simple power-law dielectric profile epsilon(i)(r) = cr(k) and a linear dielectric profile epsilon(i)(r) = c(b + r), analytical expressions of the electrical potentials and the effective dielectric response are derived exactly from our results by taking the limits b -> 0 and k -> 1, respectively. For a higher concentration of inclusions, the effective dielectric response is estimated by an effective-medium approximation. In addition, we have discussed the effective response of graded cylindrical composites with a more complex dielectric profile of inclusion, epsilon(i)(r)=c(b+r)(k)e(beta r). (c) 2005 American Institute of Physics.
Resumo:
The effective dielectric response of graded spherical composites having general power-law gradient inclusions is investigated under a uniform applied electric field, where the dielectric gradation profile of the spherical inclusions is modeled by the equation epsilon(i) (r) = c(b+r)(k). Analytical solutions of the local electrical potentials are derived in terms of hyper-geometric function and the effective dielectric response of the graded composites is predicted in the dilute limit. From our result, the local potentials of graded spherical composites having both simple power-law dielectric profile epsilon(i)(r) = cr(k) and linear dielectric profile epsilon(i) (r) = c(b+r) are derived exactly by taking the limits b --> 0 and k --> 1, respectively. In the dilute limit, our exact result is used to test the validity of differential effective dipole approximation (DEDA) for estimating the effective response of graded spherical composites, and it is shown that the DEDA is in excellent agreement with exact result. (C) 2005 Elsevier B.V. All rights reserved.
Resumo:
A rapid and sensitive liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) assay for the determination of five pharmacologically active compounds (PAC) extracted from the traditional Chinese medicine, Rhodiola , namely salidroside, tyrosol, rhodionin, gallic acid, and ethyl gallate has been developed. In this method, PAC could be baseline separated and detected with DAD at 275 nm. The validation of the method, including sensitivity, linearity, repeatability, and recovery, was examined. The linear calibration curves were acquired with correlation coefficient >0.999 and the limits of detection LOD (at a signal-to-noise ratio=3:1) were between 0.058 and 1.500 mu mol/L. It was found, that the amounts of PAC varied with different species of Rhodiola . The established method is rapid and reproducible for the separation of five natural pharmacologically active compounds from extracts of Rhodiola with satisfactory results.
Resumo:
A rapid capillary electrophoresis method for the separation of five natural pharmacologically active compounds from extracted Rhodiola, namely salidroside, tyrosol, rhodionin, gallic acid and ethyl gallate has been developed. The separation of five natural pharmacologically active compounds was carried out in a fused-silica capillary with 14 mM boric acid, 30 mM SDS and 2.5% acetonitrile, adjusted to pH 10.7 with NaOH. Applied potential was 21 kV. The temperature of the capillary was maintained at 25 degreesC by the instrument thermostating system, with the correlation coefficients of 0.9805-0.9989 for migration time, and relative standards of < 3.52% for peak areas. The established method is rapid and reproducible for the separation of five natural pharmacologically compounds from extracts of Rhodiola with satisfactory results.
Resumo:
The engineering geological properties of Neogene hard clays and related engineering problems are frontiers in the fields of Engineering Geology, Soil Mechanics and Rock Mechanics. Recently, it has been recognized that Neogene hard clay is the intermediate type of material between the soil and the rock. Many aspects of them, such as sampling, testing, calculating and engineering process, are special, which could not be researched by means of theories and methods of traditional Soil Mechanics of Rock Mechanics. In order to get real knowledge and instruct the engineering practice, intersect studying of multiple disciplines, including Engineering Geology, Soil Mechanics and Rock Mechanics, etc., is necessary. Neogene hard clay is one of the important study objects of regional problem rocks & soils in our country, which extensively distributed in China, especially in Eastern China. Taking the related areas along the middle line of the Project of Transferring Water from the South to the North (e.g. Nanyang basin, Fangcheng-Baofeng area and Handan-Yongnian area), South-west of Shandong, Xu-Huai area and Beijing area, etc. as main study areas, the paper divided Neogene hard clays into reduction environment dominated origin and oxidation environment dominated origin, which distributed on areas western and eastern to Mount Taihangshan respectively. Intermediate types are also existed in some areas, which mainly distribute near the edges of depositional basins; they are usually of transitions between diluvial and lacustrine deposits. As to Neogene hard clays from Eastern China, the clay particle content is high, and montmorillonite or illite/montmorillonite turbostratic mineral is the dominating clay mineral. The content of effective montmorillonite is very high in each area, which is the basis for the undesirable engineering properties of Neogene hard clays. For hard clays from the same area, the content of effective montmorillonite in gray-greenish hard clay is much higher than that in purple-brownish or brown-yellowish hard clay, which is the reason why the gray-greenish hard clay usually has outstanding expansive property. On the other hand, purple-brownish or brown-yellowish hard clay has relatively less montmorillonite, so its property is better. All of these prove that the composition (clay mineral) of Neogene hard clay is the control factor for the engineering properties. Neogene hard clays have obvious properties such as fissured, overconsolidated and expansive, which are the main reasons that many engineering problems and geological harzards usually occur in Neogene hard clays. The paper systematically elaborates the engineering properties of Neogene hard clays from Eastern China, analyses the relationships between engineering properties and basic indexes. The author introduces the ANN method into the prediction of engineering property indexes of hard clays, which provides a new way for quantitatively assessment and prediction of engineering property indexes. During investigation in the field, the author found that there exists obvious seam-sheared zone between different hard clays in Miocene Xiacaowan formation in Xu-Huai area. Similar phenomenon also exists near the borderline between Neogene hard clays and underlying coal measures in the Southwest of Shandong province, which could be observed in the cores. The discovery of seam-sheard zone has important theoretical and practical significance for engineering stability analysis and revealing the origin of fissures in Neogene hard clays. The macrostructure, medium structure and microstructure together control the engineering properties of hard clays. The author analyses and summarizes the structural effects on hard clays in detail. The complex of the strength property of hard clays is mostly related to the characteristics of fissures, which is one of the main factors that affect the choice of shear strength parameters. So structure-control theory must be inseparably combined with composition-control theory during the engineering geological and rock/soil mechanics research of hard clays. The engineering properties, such as fissured, overconsolidated and expansive, control the instability of engineering behaviors of Neogene hard clays under the condition of excavation, i.e. very sensitive to the change of existence environment. Based on test data analysis, the author elaborates the effects of engineering environment change on the engineering properties. Taking Nanyang basin as example, the author utilizes FEM to study the effects of various factors on stability of cutting canal slopes, than sets forth the characteristics, development laws and formation mechanism of the deformation and failure of hard clay canal slopes, summarizes the protection and reinforcement principles, as well as the protection and remedy steps. On the basis of comparison of engineering properties of domestic and foreign Neogene muddy deposits, in the view of whole globe and associated with the geological characteristics of China, the paper demonstrates that the intermediate type of the material between the soil and the rock, named "hard clay/soft rock", which can not be separated abruptly, really exists in China. The author has given a preliminary classification based on its geological origin and distribution law, which is very significant for promoting the mixture of Engineering Geology, Soil Mechanics and Rock Mechanics. In the course of large scales engineering construction in China, many engineering experiences and testing data are gained, summarizing these testing results and automatically managing them with computer technology are very necessary. The author develops a software named "Hard Clay-Soft Rock Engineering Geological Information Management and Analysis System (HRGIMS)", realizes the automatic and visual management of geo-engineering information, on the basis of information management, the functions of test data analysis and engineering property prediction are strengthened. This system has well merits for practice and popularization.
Resumo:
We have simulated numerically an automated Maxwell's demon inspired by Smoluchowski's ideas of 1912. Two gas chambers of equal area are connected via an opening that is covered by a trapdoor. The trapdoor can open to the left but not to the right, and is intended to rectify naturally occurring variations in density between the two chambers. Our results confirm that though the trapdoor behaves as a rectifier when large density differences are imposed by external means, it can not extract useful work from the thermal motion of the molecules when left on its own.
Resumo:
In Phys. Rev. Letters (73:2), Mantegna et al. conclude on the basis of Zipf rank frequency data that noncoding DNA sequence regions are more like natural languages than coding regions. We argue on the contrary that an empirical fit to Zipf"s "law" cannot be used as a criterion for similarity to natural languages. Although DNA is a presumably "organized system of signs" in Mandelbrot"s (1961) sense, and observation of statistical featurs of the sort presented in the Mantegna et al. paper does not shed light on the similarity between DNA's "gramar" and natural language grammars, just as the observation of exact Zipf-like behavior cannot distinguish between the underlying processes of tossing an M-sided die or a finite-state branching process.
Resumo:
The dream of pervasive computing is slowly becoming a reality. A number of projects around the world are constantly contributing ideas and solutions that are bound to change the way we interact with our environments and with one another. An essential component of the future is a software infrastructure that is capable of supporting interactions on scales ranging from a single physical space to intercontinental collaborations. Such infrastructure must help applications adapt to very diverse environments and must protect people's privacy and respect their personal preferences. In this paper we indicate a number of limitations present in the software infrastructures proposed so far (including our previous work). We then describe the framework for building an infrastructure that satisfies the abovementioned criteria. This framework hinges on the concepts of delegation, arbitration and high-level service discovery. Components of our own implementation of such an infrastructure are presented.
Resumo:
TYPICAL is a package for describing and making automatic inferences about a broad class of SCHEME predicate functions. These functions, called types following popular usage, delineate classes of primitive SCHEME objects, composite data structures, and abstract descriptions. TYPICAL types are generated by an extensible combinator language from either existing types or primitive terminals. These generated types are located in a lattice of predicate subsumption which captures necessary entailment between types; if satisfaction of one type necessarily entail satisfaction of another, the first type is below the second in the lattice. The inferences make by TYPICAL computes the position of the new definition within the lattice and establishes it there. This information is then accessible to both later inferences and other programs (reasoning systems, code analyzers, etc) which may need the information for their own purposes. TYPICAL was developed as a representation language for the discovery program Cyrano; particular examples are given of TYPICAL's application in the Cyrano program.