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Inherent Property (inherent + property)
Selected AbstractsDiscrepancy in glucose and fructose utilisation during fermentation by Saccharomyces cerevisiae wine yeast strainsFEMS YEAST RESEARCH, Issue 7 2004N.J. Berthels Abstract While unfermented grape must contains approximately equal amounts of the two hexoses glucose and fructose, wine producers worldwide often have to contend with high residual fructose levels (>2 g l,1) that may account for undesirable sweetness in finished dry wine. Here, we investigate the fermentation kinetics of glucose and fructose and the influence of certain environmental parameters on hexose utilisation by wine yeast. Seventeen Saccharomyces cerevisiae strains, including commercial wine yeast strains, were evaluated in laboratory-scale wine fermentations using natural Colombard grape must that contained similar amounts of glucose and fructose (approximately 110 g l,1 each). All strains showed preference for glucose, but to varying degrees. The discrepancy between glucose and fructose utilisation increased during the course of fermentation in a strain-dependent manner. We ranked the S. cerevisiae strains according to their rate of increase in GF discrepancy and we showed that this rate of increase is not correlated with the fermentation capacity of the strains. We also investigated the effect of ethanol and nitrogen addition on hexose utilisation during wine fermentation in both natural and synthetic grape must. Addition of ethanol had a stronger inhibitory effect on fructose than on glucose utilisation. Supplementation of must with assimilable nitrogen stimulated fructose utilisation more than glucose utilisation. These results show that the discrepancy between glucose and fructose utilisation during fermentation is not a fixed parameter but is dependent on the inherent properties of the yeast strain and on the external conditions. [source] Effect of molecular relaxation of acrylic elastomers on impact toughening of polybutylene terephthlateJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Nafih Mekhilef Abstract In this study, we examined the performance of two core-shell acrylic-based impact modifiers (AIM) prepared by emulsion polymerization. The rubber core was prepared from ethyl hexyl acrylate (EHA) and n -octyl acrylate (n -OA). In such as process, the particle size and particle-size distribution of the modifiers were precisely controlled, so that performance differences observed in polybutylene terephthlate (PBT), used as matrix resin, could only be interpreted in terms of the nature of the elastomeric component of the modifiers. When isolated, the rubber core of the modifiers showed identical glass transition temperatures (Tg) by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) despite the fact that they were made from two different acrylic monomers. Temperature-frequency superposition principle inferred from the classical WLF equation showed that the rubber components exhibit the same Tg at all frequencies including at the time scale at which mechanical impact typically occurs. However, significant differences in low temperature impact performance measured at ,30°C using notched Izod impact test according to ASTM D 256 were obtained even though their rubber components had identical Tg. Such differences were attributed to the dynamic relaxation behavior of the rubber components and identified as inherent properties of the elastomers due to the structure of the monomers' repeat units. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] Soil organic matter beyond molecular structure Part II: Amorphous nature and physical agingJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2006Gabriele E. Schaumann Abstract Glassy, rubbery, and crystalline phases are representatives of supramolecular structures which strongly differ in order, density, and other characteristics. In this contribution, the amorphous nature of soil organic matter (SOM) is reviewed with respect to the glassy/rubbery model, glass transition mechanisms, interactions of SOM with water, and physical aging. Glass-transition behavior and physical aging are inherent properties of amorphous solids, and numerous spectroscopic investigations give insights into different domain mobilities of humic substances (HS). The correlation between sorption nonlinearity and glassiness of polymers and HS supports a relation between sorption and amorphicity in Aldrich humic acid. Further evidence is still required for the transfer to soil HS and SOM. Sorption and differential scanning calorimetry (DSC) data suggest a correlation between aromaticity and glassiness in HS, and the available data do currently not allow to decide unambiguously between specific sorption and hole filling as explanation. This needs to be verified in future research. Although parts of the investigations have up to now only been conducted with humic substances, the collectivity of available data give strong support for the glassy/rubbery conception of SOM. They clearly indicate that amorphous characteristics cannot be excluded in SOM. This is further supported by the observation of different types of glass-transition behavior in samples of whole humous soil. In addition to classical glass transitions in water-free soil samples, water surprisingly acts in an antagonistic way as short-term plasticizer and long-term antiplasticizer in a second, nonclassical transition type. Latter is closely connected with physico-chemical interactions with water and suggests water bridges between structural elements of SOM (HBCL-model). The gradual increase of Tg* in SOM indicates physico-chemical aging processes, which are not restricted to polymers. They may be responsible for contaminant aging, changes in surface properties and increased soil compaction in agricultural soils. [source] Iatrogenic pleuropulmonary charcoal instillation in a teenagerPEDIATRIC PULMONOLOGY, Issue 6 2003Sandip A. Godambe MD Abstract Activated charcoal given through a nasogastric tube is a standard intervention for many types of toxic ingestions in the emergency department. This case study describes a teenage girl whose multidrug overdose was complicated by accidental charcoal instillation into her left lung and pleural space through a misplaced nasogastric tube. The ensuing empyema did not respond to antibiotic therapy alone, probably due to the inherent properties of charcoal, and required a chest tube placement with continuous irrigation. Unlike previously reported cases, this patient did well clinically, without long-term morbidity. Pediatr Pulmonol. 2003; 35:490,493. © 2003 Wiley-Liss, Inc. [source] Cellular shellization: Surface engineering gives cells an exteriorBIOESSAYS, Issue 8 2010Ben Wang Abstract Unlike eggs and diatoms, most single cells in nature do not have structured shells to provide extensive protection. It is a challenge to artificially confer shell structures on living cells to improve their inherent properties and functions. We discuss four different types of cellular shellizations: man-made hydrogels, sol-gels, polyelectrolytes, and mineral shells. We also explore potential applications, such as cell storage, protection, delivery, and therapy. We suggest that shellization could provide another means to regulate and functionalize cells. Specifically, the integration of living cells and non-living functional shells may be developed as a novel strategy to create "super" or intelligent cells. Unlike biological approaches, this material-based bio-interface regulation is inexpensive, effective, and convenient, opening up a novel avenue for cell-based technologies and practices. [source] A novel pharmacological concept in an animal model of psychosis,ACTA PSYCHIATRICA SCANDINAVICA, Issue 2001R. R. Dawirs Objective:,We have analysed pharmacologically induced perturbation of functional and structural neurogenesis in the prefrontal cortex (PFC) and hippocampus. Method:,Juvenile gerbils received a single dose of methamphetamine (METH, 50 mg/kg, i.p.). In adults the following parameters were quantitatively investigated: prefrontal dopaminergic and GABAergic innervation densities (immunocytochemistry), morphogenesis of pyramidal cells (Golgi), dentate granule cell proliferation (BrdU-labelling), working memory and behavioural inhibition (delayed response, open-field). Results:,A single challenge of METH continuously suppresses granule cell proliferation in adult gerbils and initiates rewiring of neuronal networks in the PFC which run concurrently with the development of severe deficits in PFC-related behaviours. Conclusion:,It appears that a continuous remodelling of neuronal circuits is an inherent property of the brain, the biological significance of which seems to be to ascertain adaptive interaction between brain and environment. Learning more about drug-induced neuronal reorganization might be basic for understanding the genesis of psychotic conditions in the brain. This presentation is based both on own research and on a review of the literature. [source] Exercise-induced neuronal plasticity in central autonomic networks: role in cardiovascular controlEXPERIMENTAL PHYSIOLOGY, Issue 9 2009Lisete C. Michelini It is now well established that brain plasticity is an inherent property not only of the developing but also of the adult brain. Numerous beneficial effects of exercise, including improved memory, cognitive function and neuroprotection, have been shown to involve an important neuroplastic component. However, whether major adaptive cardiovascular adjustments during exercise, needed to ensure proper blood perfusion of peripheral tissues, also require brain neuroplasticity, is presently unknown. This review will critically evaluate current knowledge on proposed mechanisms that are likely to underlie the continuous resetting of baroreflex control of heart rate during/after exercise and following exercise training. Accumulating evidence indicates that not only somatosensory afferents (conveyed by skeletal muscle receptors, baroreceptors and/or cardiopulmonary receptors) but also projections arising from central command neurons (in particular, peptidergic hypothalamic pre-autonomic neurons) converge into the nucleus tractus solitarii (NTS) in the dorsal brainstem, to co-ordinate complex cardiovascular adaptations during dynamic exercise. This review focuses in particular on a reciprocally interconnected network between the NTS and the hypothalamic paraventricular nucleus (PVN), which is proposed to act as a pivotal anatomical and functional substrate underlying integrative feedforward and feedback cardiovascular adjustments during exercise. Recent findings supporting neuroplastic adaptive changes within the NTS,PVN reciprocal network (e.g. remodelling of afferent inputs, structural and functional neuronal plasticity and changes in neurotransmitter content) will be discussed within the context of their role as important underlying cellular mechanisms supporting the tonic activation and improved efficacy of these central pathways in response to circulatory demand at rest and during exercise, both in sedentary and in trained individuals. We hope this review will stimulate more comprehensive studies aimed at understanding cellular and molecular mechanisms within CNS neuronal networks that contribute to exercise-induced neuroplasticity and cardiovascular adjustments. [source] Observation of Structural and Conductance Transition of Rotaxane Molecules at a Submolecular Scale,ADVANCED FUNCTIONAL MATERIALS, Issue 5 2007M. Feng Abstract Rotaxane molecules have attracted considerable interest because of their good performance in both molecular electronic devices and nanoscale data-storage media. Low-temperature scanning tunneling microscopy is used to investigate the structure and conductance of single H2 rotaxane molecules on a buffer-layered Au(111) substrate at 77,K. It is demonstrated that the conductance switching in rotaxane-based, solid-state devices is an inherent property of the rotaxane molecules. These results provide evidence that the conductance switching might arise from the movement of the cyclobis(paraquat- p -phenylene) ring along the rod section of the dumbbell-shaped backbone of the rotaxane molecule. [source] Application of piece-wise linear weight functions for 2D 8-node quadrilateral element in contact problemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 2 2004Chouping Luo Abstract The present study is a continuation of our previous work with the aim to reduce problems caused by standard higher order elements in contact problems. The difficulties can be attributed to the inherent property of the Galerkin method which gives uneven distributions of nodal forces resulting in oscillating contact pressures. The proposed remedy is use of piece-wise linear weight functions. The methods to establish stiffness and/or mass matrix for 8-node quadrilateral element in 2D are presented, i.e. the condensing and direct procedures. The energy and nodal displacement error norms are also checked to establish the convergence ratio. Interpretation of calculated contact pressures is discussed. Two new 2D 8-node quadrilateral elements, QUAD8C and QUAD8D, are derived and tested in many examples, which show their good performance in contact problems. Copyright © 2004 John Wiley & Sons, Ltd. [source] Multi-factors oriented study of P2P ChurnINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2009Dong Yang Abstract The dynamics of peers, namely Churn, is an inherent property of peer-to-peer (P2P) systems and is critical to their design and evaluation. Although every excellent P2P protocol has some solution to this issue, studies on Churn are still seldom. This paper studies various factors related to Churn, and uses them to analyze and evaluate P2P protocols. Prior researches on Churn are all based on the P2P network factors in Churn environment, and their difference is whether to use these factors as predecessor references to build Churn analytical models or as successor references to test the models. According to this difference, this paper first divides various factors into two categories: impacting Churn and affected by Churn. There is a causal relationship between these two categories. Factors impacting Churn are cause, and the factors affected by Churn are effect. In this paper, we use this causality to simulate and analyze P2P Churn. Cause is used as the input data and effect is used as the output result. Second, based on the classification of Churn factors, we present a performance evaluation framework and two comparing models. Based on the framework and models, we simulate and analyze three P2P protocols and get some useful results such as the performance of these protocols under Churn, the advantage of Chord over others, and the most important factors impacting Churn. Finally, we present a method to improve recent P2P Churn models by adding some influence factors. Copyright © 2009 John Wiley & Sons, Ltd. [source] The correlation between blood oxygenation level-dependent signal strength and latencyJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2005Karsten Müller PhD Abstract Purpose To investigate the relationship between signal strength and latency of the blood oxygenation level-dependent (BOLD) signal. Materials and Methods Several correlation analyses were performed on data obtained in a functional magnetic resonance imaging (fMRI) experiment, where subjects were presented with a simple visual stimulus. The BOLD signal strength was correlated with both the phase shift of the spectral density matrix and time-to-peak calculated from trial-averaged time courses. Correlation coefficients were calculated for visual stimuli of 2, 6, and 15 seconds in duration. Results Analyzing all functional runs for the same subject separately, i.e., including for each run all significantly activated voxels, we observed that correlations between phase shift and signal strength, as well as between time-to-peak and signal strength, decreased with increasing stimulus length. However, when analyses were restricted to voxels found activated in all functional runs, we observed similar correlations between BOLD signal strength and latency in all runs, independent of the length of stimulation. This result was again obtained for both latency measures: the spectral density phase shift and time-to-peak. Conclusion For both latency measures, phase shift and time-to-peak, a high correlation between BOLD signal strength and latency was observed. We have shown that this correlation is independent of the length of visual stimulation. Thus, the correlation between BOLD signal strength and latency seems to be an inherent property of the BOLD response that is independent of the length of stimulation and can be observed using different methods for determining signal latency. J. Magn. Reson. Imaging 2005;21:489,494. © 2005 Wiley-Liss, Inc. [source] Length dependence of polarization in spontaneous edge emissions from InGaN/AlGaN MQWs laser diodesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2007Chuanyu Jia Abstract The polarization of spontaneous edge-emitting electroluminescence from near-UV LDs with different cavity lengths (from 400 ,m to 1000 ,m) was studied. It was found that TE mode dominates in InGaN/AlGaN MQWs LDs, which is consistent with the theoretical calculation results of similar MQWs. An obvious polarization decrease from P = 0.57 to 0.42 as the LD cavity length changed from 400 ,m to 1000 ,m was also observed, corresponding to a ratio r changing from 3.67 to 2.43, which indicated that, the TE mode attenuated more grievously than the TM mode with increasing cavity length. This is due to the inherent property of polarization selective emission from the alloys. The optical loss coefficient of TE mode was determined to be 35 cm,1, while, 10 cm,1 for TM mode, which is in good agreement with the results obtained from other methods. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] River spacing and drainage network growth in widening mountain rangesBASIN RESEARCH, Issue 3 2006Sébastien Castelltort ABSTRACT Drainage networks in linear mountain ranges always display a particular geometrical organisation whereby the spacing between the major drainage basins is on average equal to half the mountain width (distance from the mountain front to the main drainage divide), independent of climate and tectonics. This relationship is valid for mountains having different widths and is thus usually thought to be maintained by drainage reorganisation during mountain belt widening. However, such large-scale systematic drainage reorganisation has never been evidenced. In this paper, we suggest an alternative explanation, namely that the observed drainage basin relationships are an inherent property of dendritic river networks and that these relationships are established on the undissected, lowland margins outside mountain ranges and are progressively incorporated and quenched into uplifted topography during range widening. Thus, we suggest that the large-scale geometry of drainage networks in mountain ranges is mainly antecedent to erosion. We propose a model in which the large-scale drainage geometry is controlled mainly by the geometrical properties of the undissected surfaces (in particular, the ratio of the regional slope to the local slope related to roughness) over which rivers are flowing before uplift, and is therefore independent of climate and tectonics. [source] Contextualizing Counterintuitiveness: How Context Affects Comprehension and Memorability of Counterintuitive ConceptsCOGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 3 2007M. Afzal Upala Abstract A number of anthropologists have argued that religious concepts are minimally counterintuitive and that this gives them mnemic advantages. This paper addresses the question of why people have the memory architecture that results in such concepts being more memorable than other types of concepts by pointing out the benefits of a memory structure that leads to better recall for minimally counterintuitive concepts and by showing how such benefits emerge in the real-time processing of comprehending narratives such as folk tales. This model suggests that memorability is not an inherent property of a concept; rather it is a property of the concept, the context in which the concept is presented, and the background knowledge that the comprehendor possesses about the concept. The model predicts how memorability of a concept should change if the context containing the concept were changed. The paper also presents the results of experiments carried out to test these predictions. [source] | ||||||||||||||||||||||