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Kinds of Different Terms modified by Different Selected AbstractsARE PINNIPEDS FUNCTIONALLY DIFFERENT FROM FISSIPED CARNIVORES?EVOLUTION, Issue 3 2000THE IMPORTANCE OF PHYLOGENETIC COMPARATIVE ANALYSES Abstract., It is widely assumed that adaptations to an aquatic lifestyle are so profound as to produce only obvious differences between pinnipeds and the remaining, largely terrestrial carnivore species ("fissipeds"). Thus, comparative studies of the order Carnivora routinely examine these groups independently. This approach is invalid for two reasons. First, fissipeds are a paraphyletic assemblage, which raises the general issue of when it is appropriate to ignore monophyly as a criterion for inclusion in comparative studies. Second, the claim that most functional characters (beyond a few undoubted characteristic features) are different in pinnipeds and fissipeds has never been quantitatively examined, nor with phylogenetic comparative methods. We test for possible differences between these two groups in relation to 20 morphological, life-history, physiological, and ecological variables. Comparisons employed the method of independent contrasts based on a complete and dated species-level phylogeny of the extant Carnivora. Pinnipeds differ from fissipeds only through evolutionary grade shifts in a limited number of life-history traits: litter weight (vs. gestation length), birth weight, and age of eyes opening (both vs. size). Otherwise, pinnipeds display the same rate of evolution as phylogenetically equivalent fissiped taxa for all variables. Overall functional differences between pinnipeds and fissipeds appear to have been overstated and may be no greater than those among major fissiped groups. Recognition of this fact should lead to a more complete understanding of carnivore biology as a whole through more unified comparative tests. Comparative studies that do not include monophyletic groups for phylogenetically based comparative tests should be reconsidered. [source] INDIVIDUAL AND COMBINED CYTOTOXIC EFFECTS OF THE MAJOR FOUR AFLATOXINS IN DIFFERENT IN VITRO STABILIZED SYSTEMSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2010CORNELIA BRAICU ABSTRACT The present study aims to investigate the cytotoxic effect of the major aflatoxins (B1, B2, G2 and G2) and also aflatoxin combination, using a simple, rapid and cheap cytotoxicity test like MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay in three in vitro models (human umbilical vein endothelial cells [HUVEC], human lung fibroblasts [HFL] and A2780 cell line) and to extrapolate the data to in vivo situation using a prediction model. A difference in cell sensitivity has been observed for B1 and B1 + B2, in the following order A2789 > HFL > HUVEC, while for B2, G1, G2, Mix (B1 + B2 + G1 + G2) the order was HFL > A2789 > HUVEC when comparing the IC50 (half maximal inhibitory concentration) values. We confirm that in vitro cytotoxicity test MTT assay is able to predict in vivo toxicity, at least for aflatoxins using the prediction model. The values of LD50 (lethal dose 50%) calculated from experiments are different for each cell line. This fact may indicate that some species are more resistant than other and target organs are not necessarily those predicted, because the A2780 ovarian cancer cells seem to be more sensitive to B1 than cells of endothelial or fibroblasts origin. PRACTICAL APPLICATIONS This study is in concordance with the international tendency that refined the current techniques to lessen pain or distress, to reduce the number of animals necessary for a particular test or to replace animals with non-whole-animal models, such as in vitro cell cultures. The practical application of such methodologies may help solve the economic problem related to very expensive in vivo toxicology studies and implement preventive methods based on the calculated data and known mechanism of action of individual or combined toxins easily studied in vitro. The nature of coexistence of many types of mycotoxins in complex environmental samples, such as food and water, has been reported worldwide. How these mycotoxins might affect human health in combination is largely unknown. This study had, as a goal, to test the toxicity of the four aflatoxins and aflatoxin combination on human cells. Due to the lack of aflatoxins mixture data regarding the human cytotoxicity, the aim of this study was to specify, evaluate and predict the combined effects of mycotoxin mixtures. [source] IMPACT OF TRAINING ON BEER FLAVOR PERCEPTION AND DESCRIPTION: ARE TRAINED AND UNTRAINED SUBJECTS REALLY DIFFERENT?JOURNAL OF SENSORY STUDIES, Issue 6 2001SYLVIE CHOLLET ABSTRACT This study examines the effect of beer assessment training on verbal and nonverbal performance. Two groups of subjects are asked to sort, match, and describe a set of 12 beers (6 supplemented and 6 commercial beers). Subjects from the first group are enrolled in a beer-training program. Subjects in the second group are untrained beer consumers. Results show that although both groups perform the matching task equally well, trained subjects performed better on supplemented beers and untrained subjects on commercial beers. Examination of the generated vocabulary shows that 44% of the terms are common to trained and untrained subjects. However, an analysis of the terms' efficiency shows that whereas for trained subjects, precise terms are more efficient than intensity or hedonic terms; the opposite is observed for untrained subjects. This suggests that it is not the term itself that is important but the common reference associated to it. [source] LOOKING DIFFERENT, ACTING DIFFERENT: STRUGGLES FOR EQUALITY WITHIN THE SOUTH AFRICAN POLICE SERVICEPUBLIC ADMINISTRATION, Issue 3 2008MONIQUE MARKS This descriptive paper tells the story of the daily difficulties that members of the Public Order Police (POP) unit in South Africa experienced in their attempts to create a more diverse (in terms of race and gender) and representative police organization. This story is told through recordings of observations and conversations that span a 4-year ethnographic journal. The paper demonstrates that despite affirmative action and equity legislation and programmes, Durban POP by the year 2001, six years after the transformation process within the unit began, was still plagued by deep racial and gender divisions. These divisions were reinforced by the structural make-up of the unit and the inability of middle management to challenge entrenched practices, as well as deep-seated assumptions, schemas and values associated with race, ethnicity and gender. By means of a ethnographic journal I was able to discover some of the daily dilemmas of the police in their change efforts and also the difficulties of getting police practice to meet new policy agendas. [source] CAN TRAINEES DO SOMETHING COMPLETELY DIFFERENT?ANZ JOURNAL OF SURGERY, Issue 11 2003David Watters FRACS No abstract is available for this article. [source] An improved study of real-time fluid simulation on GPUCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2004Enhua Wu Abstract Taking advantage of the parallelism and programmability of GPU, we solve the fluid dynamics problem completely on GPU. Different from previous methods, the whole computation is accelerated in our method by packing the scalar and vector variables into four channels of texels. In order to be adaptive to the arbitrary boundary conditions, we group the grid nodes into different types according to their positions relative to obstacles and search the node that determines the value of the current node. Then we compute the texture coordinates offsets according to the type of the boundary condition of each node to determine the corresponding variables and achieve the interaction of flows with obstacles set freely by users. The test results prove the efficiency of our method and exhibit the potential of GPU for general-purpose computations. Copyright © 2004 John Wiley & Sons, Ltd. [source] Labor productivity of small and large manufacturing firms: the case of TaiwanCONTEMPORARY ECONOMIC POLICY, Issue 3 2000M. Hsu This work studies the factors influencing the labor productivity of small and medium-sized enterprises (SMEs) and large firms using Taiwan as a case study. A special emphasis is placed on two possible international channels: exports and foreign direct investment (FDI). Different from conventional studies, we employ the two-stage switching regressions to correct the firm-size effect on labor productivity and estimate labor productivity for SMEs and large firms. The main findings are as follows. First, the estimates of the selectivity variable are statistically significant for both SMEs and large firms, supporting the hypothesis of correcting the effect of firm-size truncation. Second, while a larger trade intensity significantly increases the labor productivity of SMEs, it deteriorates significantly that of large firms. Third, FDI enhances the labor productivity of SMEs internally, whereas it has a negative spillover on that of other small and large firms in the industry. While the first outcome lends supports to the role of self-selection, the remaining stands in sharp contrast to conventional wisdom. [source] AFM study of the surface morphology of the {100} cleavage planes of L-arginine phosphate monohydrate single crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2004Y. L. Geng Abstract Surface morphology of the {100} cleavage planes of L-arginine phosphate monohydrate single crystals grown from aqueous solutions is described and discussed. Different from the previous studies, dislocations are not frequently detected and most of them don't have hollow cores on the emergence points. Various step patterns are also described. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fractional CO2 laser: a novel therapeutic device upon photobiomodulation of tissue remodeling and cytokine pathway of tissue repairDERMATOLOGIC THERAPY, Issue 2009F. Prignano ABSTRACT Minimally ablative fractional laser devices have gained acceptance as a preferred method for skin resurfacing. Notable improvements in facial rhytides, photodamage, acne scarring, and skin laxity have been reported. The aim of the present work was to compare how different CO2 laser fluences, by modulating the secretory pathway of cytokines, are able to influence the wound-healing process, and how these fluences are associated with different clinical results. Eighteen patients, all with photodamaged skin, were treated using a fractional CO2 laser (SmartXide DOT, Deka M.E.L.A., Florence, Italy) with varying laser fluences (2.07, 2.77, and 4.15 J/cm2). An immunocytochemical study was performed at defined end points in order to obtain information about specific cytokines of the microenvironment before and after treatment. The secretory pathway of cytokines changed depending on the re-epithelization and the different laser fluences. Different but significant improvements in wrinkles, skin texture, and hyperpigmentation were definitely obtained when using 2.07, 2.77, and 4.15 J/cm2, indicating fractional CO2 laser as a valuable tool in photorejuvenation with good clinical results, rapid downtime, and an excellent safety profile. [source] Experimental study of rill bank collapseEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2007Jovan R. Stefanovic Abstract Rill bank collapse is an important component in the adjustment of channel morphology to changes in discharge and sediment flux. Sediment inputs from bank collapse cause abrupt changes in flow resistance, flow patterns and downstream sediment concentrations. Generally, bank retreat involves gradual lateral erosion, caused by flow shear stress, and sudden bank collapse, triggered by complex interactions between channel flow and bank and soil water conditions. Collapse occurs when bank height exceeds the critical height where gravitational forces overcome soil shear strength. An experimental study examined conditions for collapse in eroding rill channels. Experiments with and without a deep water table were carried out on a meandering rill channel in a loamy sand and sandy loam in a laboratory flume under simulated rainfall and controlled runon. Different discharges were used to initiate knickpoint and rill incision. Soil water dynamics were monitored using microstandpipes, tensiometers and time domain reflectometer probes (TDR probes). Bank collapse occurred with newly developed or rising pre-existing water tables near rill banks, associated with knickpoint migration. Knickpoint scour increased effective bank height, caused positive pore water pressure in the bank toe and reduced negative pore pressures in the unsaturated zone to near zero. Matric tension in unsaturated parts of the bank and a surface seal on the ,interrill' zone behind the bank enhanced stability, while increased effective bank height and positive pore water pressure at the bank toe caused instability. With soil water contents >35 per cent (sandy loam) and >23 per cent (loamy sand), critical bank heights were 0·11,0·12 m and 0·06,0·07 m, respectively. Bank toe undercutting at the outside of the rill bends also triggered instability. Bank displacement was quite different on the two soils. On the loamy sand, the failed block slid to the channel bed, revealing only the upper half of the failure plane, while on the sandy loam the failed block toppled forwards, exposing the failure plane for the complete bank height. This study has shown that it is possible to predict location, frequency and magnitude of the rill bank collapse, providing a basis for incorporation into predictive models for hillslope soil loss or rill network development. Copyright © 2006 John Wiley & Sons, Ltd. [source] Glycogen: A novel branched polysaccharide chiral selector in CEELECTROPHORESIS, Issue 6 2010Jiaquan Chen Abstract Various chiral selectors have been employed in CE and among them linear polysaccharides exhibited powerful enantioselective properties. Different from linear polysaccharides, the use of branched polysaccharides as chiral selectors in CE has not been reported previously. In this study glycogen belonging to the class of branched polysaccharides was used as a novel chiral selector for the enantiomeric separations for the first time. Since glycogen is electrically neutral, the method is applicable to ionic compounds. Eighteen chiral compounds including 12 basic drugs and six acidic drugs have been tested to demonstrate the potential of this chiral selector. BGE and selector concentrations and buffer pH were systematically optimized in order to obtain successful chiral separations. Among the tested compounds, the enantiomers of ibuprofen, which is an acidic drug, were successfully recognized by 3.0%,w/v glycogen with 90,mM Tris-H3PO4 buffer (pH 7.0). The enantiomers of basic drugs such as citalopram, cetirizine and nefopam were also baseline-resolved with 50,mM Tris-H3PO4 buffer (pH 3.0) containing 3.0% glycogen. Amlodipine belonging to basic compound only gave partial enantioseparation under the above-mentioned condition. [source] Social and Commercial Entrepreneurship: Same, Different, or Both?ENTREPRENEURSHIP THEORY AND PRACTICE, Issue 1 2006James Austin Entrepreneurship has been the engine propelling much of the growth of the business sector as well as a driving force behind the rapid expansion of the social sector. This article offers a comparative analysis of commercial and social entrepreneurship using a prevailing analytical model from commercial entrepreneurship. The analysis highlights key similarities and differences between these two forms of entrepreneurship and presents a framework on how to approach the social entrepreneurial process more systematically and effectively. We explore the implications of this analysis of social entrepreneurship for both practitioners and researchers. [source] Synthesis and Functionalization of Germanium Triphenylcorrolate: The First Example of a Partially Brominated CorroleEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2007Sara Nardis Abstract Ge complexes of 5,10,15-triphenylcorrole were prepared in refluxing dry DMF using GeCl4 as the source of Ge. Chromatographic separation of the crude reaction mixture afforded the ,-oxo dimer 1 and the methoxy derivative 2a. The corresponding chloride 2b can be obtained by treatment of 1 or 2a with HCl. The reaction of 2a with Br2 in CHCl3/py afforded the hexabromo derivative 3 as the main product, giving the first indication of the regioselective substitution of pyrroles B and C on the corrole ring. The fully brominated open-chain tetrapyrrole 4 was also characterized as a reaction by-product. Different partially brominated Ge complexes 5 and 6 have been obtained by variation of reaction conditions, while the heptabromo derivative was obtained in a mixture with the corresponding fully brominated Gecorrole. Photophysical characterization of Ge corrolates confirmed the high fluorescence quantum yield of such complexes, and also led to the first observation of phosphorescence emissions from corrole complexes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Strategies for Improving Tensile Ductility of Bulk Nanostructured Materials,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Yonghao Zhao Abstract The low ductility that is consistently associated with bulk nanostructured (NS) materials has been identified as perhaps the single most critical issue that must be resolved before this novel class of materials can be used in a wide variety of applications. Not surprisingly, a number of published studies, published mostly after 2000, identify the issue of low ductility and describe strategies to improve ductility. Details of these strategies were discussed in review papers published by Koch and Ma in 2005 and 2006, respectively.15,16 In view of continued efforts and recent results, in this paper we describe progress in attempting to address the low ductility of NS materials, after 2006. We first analyze the fundamental reasons for the observed low ductility of bulk NS materials, and summarize early (prior to 2006) attempts to enhance the ductility of bulk NS materials, which often sacrificed the strength. Then, we review recent progress in developing strategies for improving the tensile ductility of bulk NS materials, which involve mainly microstructure modifications, after 2006. Different from early efforts, these new strategies strive to increase the tensile ductility while increasing/maintaining the strength simultaneously. In addition, the influence of tensile testing conditions, including temperature, strain rate, tensile specimen size and geometry, and strain measurement methods, on tensile ductility of NS materials will also be reviewed. Finally, we identify several issues that will require further, in depth analysis in the future. [source] Is politician A or politician B more persuasive? recipients' source preference and the direction of biased message processingEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 5 2003René Ziegler Participants' preference for one of two politicians running for the post of Chancellor in Germany was measured. Under conditions conducive to effortful processing, participants were then presented with a persuasive message ascribed to one of these two sources. The message was either unambiguous strong, unambiguous weak, or ambiguous. Different from previous research on the role of message ambiguity for attitude change, the ambiguous message consisted of arguments rated as moderately convincing in a pretest rather than of a mixture of strong and weak arguments. The results were in line with predictions derived from the heuristic-systematic model (HSM). Indicating unbiased systematic processing, an unambiguous strong message led to more agreement than an unambiguous weak message. In the case of an ambiguous message, in line with the HSM's bias hypothesis, more agreement was found among participants preferring the source politician as compared to participants preferring the other politician. Copyright © 2003 John Wiley & Sons, Ltd. [source] Hierarchical ZnS-In2S3 -CuS Nanospheres with Nanoporous Structure: Facile Synthesis, Growth Mechanism, and Excellent Photocatalytic ActivityADVANCED FUNCTIONAL MATERIALS, Issue 19 2010Yingxuan Li Abstract Without using any templates or surfactants, hierarchical ZnS-In2S3 -CuS nanospheres with nanoporous structure are successfully synthesized via a simple and convenient process. The nanospheres are aggregations of densely packed nanoparticles and nanorods. Different to the oriented attachment (OA) mechanism reported in the literature, the formation of these nanorods is believed to follow a lateral OA mechanism (nanoparticles attach along the direction perpendicular to the crystallographic axes with lateral planes as the juncture) based on the experimental data. This process could be a general phenomenon and would provide a new insight into the OA mechanism. A detailed time-resolved TEM kinetic study of the formation of the complex structure is shown. The dipole mechanism and electric field-induced growth are found to be responsible for the final architecture. Photocatalytic activities for water splitting are investigated under visible-light irradiation (, > 400 nm) and an especially high photocatalytic activity (apparent yield of 22.6% at 420 nm) is achieved by unloaded ZnIn0.25Cu0.02S1.395 prepared at 180 °C for 18 h because of their high crystallinity, large pore volume, and the presence of nanorods with special microstructures. [source] Stress intensity factors for cracked triangular cross-section thin-walled tubesFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 12 2004Y. J. XIE ABSTRACT For one kind of finite-boundary crack problems, the cracked equilateral triangular cross-section tube, an analytical and very simple method to determine the stress intensity factors has been proposed based on a new concept of crack surface widening energy release rate and the principle of virtual work. Different from the classical crack extension energy release rate, the crack surface widening energy release rate can be defined by the G*-integral theory and expressed by stress intensity factors. This energy release rate can also be defined easily by the elementary strength theory for slender structures and expressed by axial strains and loads. These two forms of crack surface widening energy release rate constitute the basis of a new analysis method for cracked tubes. From present discussions, a series of stress intensity factors are derived for cracked equilateral triangular cross-section tubes. Actually, the present method can also be applied to cracked polygonal tubes. [source] The interaction between ,S, the stationary phase , factor, and the core enzyme of Escherichia coli RNA polymeraseGENES TO CELLS, Issue 3 2002Frédéric Colland Background: The RNA polymerase holoenzyme of Escherichia coli is composed of a core enzyme (subunit structure ,2,,,) associated with one of the , subunits, required for promoter recognition. Different , factors compete for core binding. Among the seven , factors present in E. coli, ,70 controls gene transcription during the exponential phase, whereas ,S regulates the transcription of genes in the stationary phase or in response to different stresses. Using labelled ,S and ,70, we compared the affinities of both , factors for core binding and investigated the structural changes in the different subunits involved in the formation of the holoenzymes. Results: Using native polyacrylamide gel electrophoresis, we demonstrate that ,S binds to the core enzyme with fivefold reduced affinity compared to ,70. Using iron chelate protein footprinting, we show that the core enzyme significantly reduces polypeptide backbone solvent accessibility in regions 1.1, 2.5, 3.1 and 3.2 of ,S, while increasing the accessibility in region 4.1 of ,S. We have also analysed the positioning of ,S on the holoenzyme by the proximity-dependent protein cleavage method using ,S derivatives in which FeBABE was tethered to single cysteine residues at nine different positions. Protein cutting patterns are observed on the , and ,, subunits, but not ,. Regions 2.5, 3.1 and 3.2 of ,S are close to both , and ,, subunits, in agreement with iron chelate protein footprinting data. Conclusions: A comparison between these results using ,S and previous data from ,70 indicates similar contact patterns on the core subunits and similar characteristic changes associated with holoenzyme formation, despite striking differences in the accessibility of regions 4.1 and 4.2. [source] Similar and Yet Still Different?GERMAN RESEARCH, Issue 2 2003Heike Wolf Dipl.-Psych. Do the predisposition of our genes or the influence from our environment influence human behaviour? A study of twins provides new information [source] Organized Nanostructured Complexes of Polyoxometalates and Surfactants that Exhibit Photoluminescence and ElectrochromismADVANCED FUNCTIONAL MATERIALS, Issue 4 2009Tierui Zhang Abstract A variety of functional nanostructured organic/inorganic hybrid materials from the europium-exchanged derivative of a Preyssler-type polyoxometalate (POM), [EuP5W30O110]12,, and functional organic surfactants were prepared by the ionic self-assembly (ISA) route. The effect of organic surfactants on the structure, photoluminescent, electrochemical and electrochromic properties of the POM anions was investigated in detail. All obtained hybrid materials are amphotropic, i.e., exhibit both thermotropic and lyotropic liquid-crystalline phase behaviour. Investigations of their photophysical properties have shown that the interactions of the various surfactants with the polyanions influence the coordination environments and site symmetry of Eu3+ in different ways. The functional groups in the organic surfactants significantly influence the electrochromic properties and photoluminescence of POMs. Different from normal and pyridine-containing complexes, no photoluminescence and no electrochromism were observed from the ferrocene-containing complexes. This may be explained in view of charge transfer between the POM anion and the ferrocenyl group. [source] Synthesis and Reactivity of , -Electron-Deficient (Arylsulfonyl)acetatesHELVETICA CHIMICA ACTA, Issue 12 2002Diego Different , -electron-deficient (arylsulfonyl)acetates 9 were synthesized (Scheme,1, Table,1), and their behavior as soft nucleophiles in the dialkylation reaction under phase-transfer catalysis conditions was studied (Schemes,2 and 3, Tables,2 and 3). The [3,5-bis(trifluoromethyl)phenyl]sulfonyl group was shown to be the best substituent for the stereoselective synthesis of (E)-aconitates 18via an alkylation hydro-sulfonyl-elimination integrated process under very mild phase-transfer-catalysis conditions (Scheme,5, Table,4). Sulfonylacetates 9h,i also underwent smooth Diels-Alder reactions with acyclic and cyclic dienes via in situ formation of the appropriate dienophile through a Knoevenagel condensation with paraformaldehyde (Scheme,6). Reductive desulfonylation with Zn and NH4Cl in THF was shown to be an efficient method for removal of the synthetically useful sulfonyl moiety (Scheme,7). [source] Infant crying and maternal holding in the first 2 months of age: an Italian diary studyINFANT AND CHILD DEVELOPMENT, Issue 6 2008Sabrina Bonichini Abstract This study aims to confirm previous North American and North European findings about the normal developmental pattern of infant crying by studying the crying of Italian babies. A cohort of 70 healthy, full-term Italian infants was assessed longitudinally at 2, 5 and 8 weeks of age. Mothers were asked to fill in 24-h behaviour diaries for 3 consecutive days at each age. Results show significant differences in the amount of daily crying between 2 and 8 weeks and between 5 and 8 weeks. Different from other similar studies, no significant cry peak at 5 weeks was found in the Italian babies, but the amount of time Italian mothers spent holding their babies showed a peak at 5 weeks. Infants cried more during the evenings and mothers carried them most during this part of the day. Significant correlations between maternal holding and infant crying were found both concurrently and predictively. The amount of infant crying at 2 weeks predicted the amount of holding at 5 weeks. Results confirmed previous findings about the individual stability of daily crying in the first 8 weeks of age, but future research should take account of cultural variations in maternal holding in studying infant crying in different societies. Copyright © 2008 John Wiley & Sons, Ltd. [source] Impact of heat shock on heat shock proteins expression, biological and commercial traits of Bombyx moriINSECT SCIENCE, Issue 4 2006VASUDHA B. CHAVADI Abstract We report the thermotolerance of new bivoltine silkworm, Bombyx mori strains NB4D2, KSO1, NP2, CSR2 and CSR4and differential expression of heat shock proteins at different instars. Different instars of silkworm larva were subjected to heat shock at 35°C, 40°C and 45°C for 2 hours followed by 2 hours recovery. Heat shock proteins were analyzed by SDS-PAGE. The impact of heat shock on commercial traits of cocoons was analyzed by following different strategies in terms of acquired thermotolerance over control. Comparatively NP2 exhibited better survivability than other strains. Resistance to heat shock was increased as larval development proceeds in the order of first instar > second instar > third instar > fourth instar > fifth instar in all silkworm strains. Expression of heat shock proteins varies in different instars. 90 kDa in the first, second and third instars, 84 kDa in the fourth instar and 84, 62, 60, 47 and 33 kDa heat shock proteins in fifth instar was observed in response to heat shock. Relative influence of heat shock on commercial traits that correspond to different stages was significant in all strains. In NB4D2, cocoon and shell weight significantly increased to 17.52% and 19.44% over control respectively. Heat shock proteins as molecular markers for evaluation and evolution of thermotolerant silkworm strains for tropics was discussed. [source] A new Cosserat-like constitutive model for bedded salt rocksINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2009Yin-Ping Li Abstract Salt rocks are commonly used as geologic host rocks for storage of gas and crude oil, and are being considered for the disposal of radioactive waste. Different from the salt rock domes in many countries, the salt rock formations in China are usually laminar with many alternating layers, i.e. rock salt, anhydrite, and/or mudstone. Considering the unique stratigraphic characteristics of these salt rocks, a new Cosserat-like medium constitutive model is proposed in order to facilitate efficient modeling of the mechanical behavior of these formations. In this model, a new representative volume element, containing two different layers, is employed to simulate the compatibility of the meso-displacement between two different layers and also the bending effect. A new method for the deformation and failure analysis of bedded salt rocks is derived therefrom. Having the macro-average stresses, the conventional stresses in the different layers can be obtained in sequence. The conventional stresses can then be utilized in a routine way for the strength and failure analysis. For the initial numerical modeling, the new Cosserat-like medium is reduced to a transversely isotropic one. The simplified constitutive model for layered media is then implemented into FLAC3D codes. A test sample validates that the results by using the numerical model are in good agreement with that by using the built-in model, and the mesh size for the new model is reduced greatly. Finally, an application for the stability of oil storage caverns in deep thinly bedded salt rocks is carried out. The effects on convergence of storage caverns and on the failure of surrounding rock due to the presence of the mudstone interlayers (hard phase) are discussed in detail. Copyright © 2009 John Wiley & Sons, Ltd. [source] ASOM applied to column stabilityINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 10 2008A. Ranjbaran Abstract A new method for computation of buckling load and mode shape of a non-uniform column is proposed. Based on the principles of calculus of variations the stability analysis of the column is defined as an optimization problem. Different known techniques of optimization are candidates for solution process. Through analysis of typical columns and comparison of the results with those of other methods, the basic theory and implementation of the presented method is verified. Copyright © 2007 John Wiley & Sons, Ltd. [source] An efficient co-rotational formulation for curved triangular shell elementINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 9 2007Zhongxue Li Abstract A 6-node curved triangular shell element formulation based on a co-rotational framework is proposed to solve large-displacement and large-rotation problems, in which part of the rigid-body translations and all rigid-body rotations in the global co-ordinate system are excluded in calculating the element strain energy. Thus, an element-independent formulation is achieved. Besides three translational displacement variables, two components of the mid-surface normal vector at each node are defined as vectorial rotational variables; these two additional variables render all nodal variables additive in an incremental solution procedure. To alleviate the membrane and shear locking phenomena, the membrane strains and the out-of-plane shear strains are replaced with assumed strains in calculating the element strain energy. The strategy used in the mixed interpolation of tensorial components approach is employed in defining the assumed strains. The internal force vector and the element tangent stiffness matrix are obtained from calculating directly the first derivative and second derivative of the element strain energy with respect to the nodal variables, respectively. Different from most other existing co-rotational element formulations, all nodal variables in the present curved triangular shell formulation are commutative in calculating the second derivative of the strain energy; as a result, the element tangent stiffness matrix is symmetric and is updated by using the total values of the nodal variables in an incremental solution procedure. Such update procedure is advantageous in solving dynamic problems. Finally, several elastic plate and shell problems are solved to demonstrate the reliability, efficiency, and convergence of the present formulation. Copyright © 2007 John Wiley & Sons, Ltd. [source] A multigrid procedure for Cartesian ghost-cell methodsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 7 2008L. A. Catalano Abstract This paper proposes a multigrid technique for Cartesian grid flow solvers. A recently developed ghost body-cell method for inviscid flows is combined with a nested-level local refinement procedure, which employs multigrid to accelerate convergence to steady state. Different from standard multigrid applications for body-fitted grids, a fictitious residual needs to be defined in the ghost cells to perform a correct residual collection and thus to avoid possible stalling of the multigrid procedure. The efficiency of the proposed local refinement multigrid Cartesian method is demonstrated for the case of the inviscid subsonic flow past a circular body. Copyright © 2008 John Wiley & Sons, Ltd. [source] Filter-based fault detection and diagnosis using output PDFs for stochastic systems with time delaysINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 4 2006Y. M. Zhang Abstract In this paper, a fault detection and diagnosis (FDD) scheme is studied for general stochastic dynamic systems subjected to state time delays. Different from the formulation of classical FDD problems, it is supposed that the measured information for the FDD is the probability density function (PDF) of the system output rather than its actual value. A B-spline expansion technique is applied so that the output PDF can be formulated in terms of the dynamic weights of the B-spline expansion, by which a time delay model can be established between the input and the weights with non-linearities and modelling errors. As a result, the concerned FDD problem can be transformed into a classic FDD problem subject to an uncertain non-linear system with time delays. Feasible criteria to detect the system fault are obtained and a fault diagnosis method is further presented to estimate the fault. Simple simulations are given to demonstrate the efficiency of the proposed approach. Copyright © 2006 John Wiley & Sons, Ltd. [source] Synthesis and Dielectric Properties of Niobia Coating on BaTiO3INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2009Jia-Jia Gan Different from conventional powder mixing, this study demonstrates a method of homogeneous coating for niobia (Nb2O5) on ferroelectric barium titanate (BaTiO3) powders. The precipitation of Nb coating with pH has been determined quantitatively by the inductance-coupled plasma method. Crystalline phases were determined by X-ray diffractometry, and the formation of a "core-shell" structure with a Nb concentration gradient was observed by a transmission electron microscope with X-ray energy-dispersive spectroscopy. The dielectric constant (K) of the samples prepared by the nanocoating method showed a more stable temperature coefficient of capacitance and well satisfied the requirements of X7R. [source] When Small Is Different: Some Recent Advances in Concepts and Applications of Nanoscale Phenomena,ADVANCED MATERIALS, Issue 5 2007G. Hodes Abstract Reduction in size often does more than simply make things smaller. There are many properties of materials that undergo qualitative, often sudden, changes below a certain size scale. This Report first describes some of these size-dependent properties. Following this general description, recent developments in a number of selected topics in nanoscience are covered. These topics are: luminescence from Au nanoparticles; Si (and related) nanoparticle luminescence; modification of optical absorption by surface adsorption on nanoparticles; and transistors (and some other devices) based on nanotubes and nanowires. [source] | |||||||||||||||||||||||||||||||||||||