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Various Data (various + data)
Selected AbstractsThe RhaS activator controls the Erwinia chrysanthemi 3937 genes rhiN, rhiT and rhiE involved in rhamnogalacturonan catabolismMOLECULAR MICROBIOLOGY, Issue 5 2004Nicole Hugouvieux-Cotte-Pattat Summary Erwinia chrysanthemi causes soft-rot diseases of various plants by enzymatic degradation of the pectin in plant cell walls. The linear regions of pectin are composed of an acidic sugar, d -galacturonic acid. The ramified regions of pectin also include neutral sugars, and are rich in l -rhamnose residues. E. chrysanthemi is able to degrade these polysaccharides, polygalacturonate and rhamnogalacturonate. In E. chrysanthemi, the production of pectinases acting on linear regions is induced in the presence of polygalacturonate by a mechanism involving the repressor KdgR. The induction of the two adjacent E. chrysanthemi genes, designated rhiT and rhiN, is maximal after the simultaneous addition of both polygalacturonate and l -rhamnose. The rhiT product is homologous to the oligogalacturonide transporter TogT of E. chrysanthemi. The rhiN product is homologous to various proteins of unknown function, including a protein encoded by the plant-inducible locus picA of Agrobacterium tumefaciens. Both rhiT and rhiN are highly induced during plant infection. Various data suggest that RhiT and RhiN are involved in rhamnogalacturonate catabolism. RhiN is able to degrade the oligomers liberated by the rhamnogalacturonate lyase RhiE. The induction of the rhiTN operon in the presence of polygalacturonate results from control by the repressor KdgR. The additional induction of these genes by rhamnose is directly mediated by RhaS, a protein homologous to the activator of rhamnose catabolism in Escherichia coli. The virulence of an E. chrysanthemi rhaS mutant towards different host plants was clearly reduced. In this phytopathogenic bacterial species, RhaS positively regulates the transcription of the rhaBAD operon, involved in rhamnose catabolism, of the rhiE gene and of the rhiTN operon. The regulator RhaS plays a larger role in E. chrysanthemi than in other enterobacteria. Indeed, the RhaS control is not restricted to the catabolism of rhamnose but is extended to the degradation of plant polysaccharides that contain this sugar. [source] Measurement of physical work capacity during arm and shoulder lifting at various shoulder flexion and ad/abduction anglesHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 2 2003Jung-Yong Kim The purpose of this study was to provide information on physical work capacity during arm and shoulder lifting at various shoulder flexion and ad/abduction angles. We measured the maximum voluntary contractions (MVCs) in 20 male participants during controlled one-arm lifting. The lifting involved upward motion of the scapula at various shoulder angles. Simultaneously, the electromyographic (EMG) activity of 3 shoulder muscles and psychophysical workload were also recorded. The various measurements were compared to provide a multidimensional assessment of the physical work capacity of the shoulder at various working angles. In particular, 90 and 120 degrees of flexion, 30 degrees of adduction, and 90 degrees of abduction were found to be the most vulnerable angles based on the measured MVCs. The average root mean square value of the EMG increased most significantly at 90 to 150 degrees of flexion and at 30 and 60 degrees of abduction. Slightly different measurements were compared to validate the results. In addition, a 3-D static biomechanical model was used to show whether the estimated shoulder workload matched the measured physical capacity of the shoulder. In conclusion, these results may help ergonomists to identify shoulder angles associated with a relatively high risk of injury, and to match the workload with the physical capacity of the shoulder. Task-specific information on shoulder work capacity is needed in the manufacturing and shipbuilding industries to protect workers from acute injuries and cumulative trauma disorders of the shoulder. Experimental results provide various data on shoulder work capacity during realistic multijoint arm and shoulder lifting, and should help lead to improvements in workplace ergonomic design. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 153,163, 2003. [source] A destructuration theory and its application to SANICLAY modelINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 10 2010Mahdi Taiebat Abstract Many natural clays have an undisturbed shear strength in excess of the remoulded strength. Destructuration modeling provides a means to account for such sensitivity in a constitutive model. This paper extends the SANICLAY model to include destructuration. Two distinct types of destructuration are considered: isotropic and frictional. The former is a concept already presented in relation to other models and in essence constitutes a mechanism of isotropic softening of the yield surface with destructuration. The latter refers to the reduction of the critical stress ratio reflecting the effect of destructuration on the friction angle, and is believed to be a novel proposition. Both the types depend on a measure of destructuration rate expressed in terms of combined plastic volumetric and deviatoric strain rates. The SANICLAY model itself is generalized from its previous form by additional dependence of the yield surface on the third isotropic stress invariant. Such a generalization allows to obtain as particular cases simplified model versions of lower complexity including one with a single surface and associative flow rule, by simply setting accordingly parameters of the generalized version. A detailed calibration procedure of the relatively few model constants is presented, and the performance of three versions of the model, in descending order of complexity, is validated by comparison of simulations to various data for oedometric consolidation followed by triaxial undrained compression and extension tests on two structured clays. Copyright © 2009 John Wiley & Sons, Ltd. [source] Variation in vegetative water use in the savannas of the North Australian Tropical TransectJOURNAL OF VEGETATION SCIENCE, Issue 3 2002Garry D. Cook Abstract. The decline in tree density on sandy soils in savannas is highly correlated with declining mean annual rainfall along the North Australian Tropical Transect (NATT). We reanalyse various data on water use by individual trees and argue that a common relationship can be used to estimate annual water use by tree stands along the NATT from ca. 600 mm mean annual rainfall to at least 1600 mm. Where rainfall is less than 600 mm, trees of a given size use less water than at sites where rainfall is higher. We use these relationships to relate water use at the stand scale with mean annual rainfall along the NATT. From this we show that the empirical data imply that the minimum depth of sandy soil that needs to be exploited by trees declines with increasing aridity along the NATT from more than 5 m to less than 1 m. This finding is consistent with other observations and the pattern that with increasing aridity, an increasing proportion of rainfall coming from isolated storms rather than from periods of extended monsoon activity. [source] Spatial substituent effects of various fluorinated groups on the 13C chemical shifts in cyclohexanesMAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2007Yvan Carcenac Abstract The effect of introduction of fluorinated groups (CH2F, CHF2, CF3, C2F5, OCF3, SCF3) on the 13C NMR chemical shifts in cyclohexanes is examined. The two main effects are caused by location at the , and , carbon positions. Comparison of the various data allowed the calculation of increments corresponding to the introduction of fluorinated groups at axial or equatorial positions on the cyclohexane ring. The introduction of fluorine atoms in methoxy and thiomethoxy groups has only a slight effect through the heteroatom on the 13C chemical shifts. Copyright © 2007 John Wiley & Sons, Ltd. [source] MicroReview: Impact of the bacterial type I cytochrome c maturation system on different biological processesMOLECULAR MICROBIOLOGY, Issue 6 2005Nicholas P. Cianciotto Summary In the ,-, ,- and ,- Proteobacteria, the so-called cytochrome c maturation (Ccm) system is known to promote the covalent attachment of the haem to periplasmic apocytochrome c. However, in species of Pseudomonas, Rhizobium, Paracoccus and Legionella, mutations in ccm genes result in phenotypes that cannot be readily explained by the simple loss of a c -type cytochrome. These phenotypes include loss of siderophore production and utilization, reduced abilities to grow in low-iron conditions and in mammalian and protozoan host cells, and alterations in copper sensitivity and manganese oxidation. These various data suggest that Ccm proteins may perform one or more functions in addition to Ccm, which are critical for bacterial physiology and growth. Novel hypotheses that should be explored include the utilization of Ccm-associated haem for processes besides attachment to apocytochrome c, the export of a non-haem compound through the Ccm system, and the negative effects of protoporphyrin IX accumulation. [source] On the graphitisation role of oxide supports in carbon nanotube CVD synthesisPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 10 2008M. H. Rümmeli Abstract In this contribution we present various data from CNT grown from supported catalysts. The observed data are in agreement with the catalyst volume to surface area model developed for floating catalysts and which predicts a direct CNT diameter and number of wall dependence on the catalyst size. Further, our studies point to the root of a CNT lying at the support rather than the catalyst. Additional supporting studies point to oxygen playing a critical role in the growth of CNT, viz. the CNT can grow from an oxide support rather than the catalyst. In this scenario the catalysts role is twofold; to precipitate carbon from the catalyst,carbon eutectic upon supersaturation and thus form the embryonic caps and to form circular defect sites at its circumference on the oxide support. These circular defect sites enable continued CNT growth directly from the support. Our findings point to catalytic processes very reminiscent of many other heterogeneous catalytic processes. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The income elasticity of meat: a meta-analysisAUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 4 2010Craig A. Gallet The demand for meat has been estimated by many studies utilizing various data and estimation methods. In this study, we perform a meta-analysis of the income elasticity of meat that involves regressing 3357 estimated income elasticities, collected from 393 studies, on variables that control for study characteristics. Across several meta-regression specifications, we find significant differences in income elasticities tied to the type of meat being studied, as well as a few functional forms, data aggregations, publication characteristics, and locations of demand. However, many study characteristics do not significantly influence reported income elasticities. Less concern should be given to such characteristics when choosing an income elasticity from the literature. [source] Logging Evaluation of the Ordovician Carbonate Reservoir Beds in the Lungudong Region, Tarim BasinACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010YANG Wenjing Abstract: In recent years, great progress has been made constantly in oil and gas exploration in the Lungudong region of the Tarim Basin. However, progress has been slow in the evaluation of its main oil-producing horizons , the Ordovician carbonate reservoir beds. Based on previous researches and on the various data such as drilling, geology and oil test, in combination with the interpretation of each single-well imaging and conventional logging data, and through analysis and comparison, the identification methods in imaging and conventional logging for four types of carbonate reservoir beds in this region are summarized in this paper. Calculation formulas for four reservoir bed parameters, i. e. shale content, porosity, permeability and oil saturation in this region are proposed; and reservoir beds in this region are divided into three levels (I, II and III) by combining oil test data and logging data, The lower limits of the effective porosity of reservoir beds and the fracture porosity of effective reservoir beds are determined as 1.8% and 0.04%, respectively. The physical property parameters are calculated by conventional logging curves, and the most advantageous areas for reservoir development are predicted comprehensively. On the plane, the high-value zones of reservoir bed parameters are mainly concentrated in the N-S-trending strike-slip fault, the Sangtamu fault horst zone and near the LG38 well area; vertically, the reservoir bed parameters of the Yijianfang Formation are better than those of the Yingshan and Lianglitage formations. [source] | |||||||||||||