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Physical Aspects (physical + aspect)
Selected AbstractsClassification of synchronous oceanic and atmospheric El Niño-Southern Oscillation (ENSO) events for palaeoclimate reconstructionINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2005Joëlle L. Gergis Abstract Since the mid-1970s, ENSO has changed in character to a predominance of El Niño conditions, the extreme phase of which appears coincidental with increases in global temperature records. Instrumental time series (<150 years) are too short to adequately address the significance of late twentieth-century ENSO variability, thus, multi-century palaeoclimate reconstructions derived from long proxy records are sought. Despite the global influence exerted by ENSO on society, limited consensus exists within the scientific community as to which index best defines the timing, duration and strength of events. Here we address issues associated with the complexity of ENSO characterisation by comparing the ,event capture' ability of two currently used indices of ENSO. It is suggested that the use of a sole ENSO index is undesirable as a given index is only indicative of one physical aspect of the phenomenon, and as such is unlikely to be representative of the wider interactions experienced in the coupled ocean-atmospheric system. In an attempt to describe more of the nature and evolution of ENSO events, the Coupled ENSO Index (CEI) classification scheme was devised to identify synchronous oceanic (Niño 3.4 SST) and atmospheric (Southern Oscillation Index) anomalies associated with ENSO for the instrumental period (1871,2003). The CEI is of practical relevance to the ENSO community as it provides an amplitude preserving instrumental baseline for the calibration of proxy records to reconstruct both components of the ENSO system. Analysis of the nature of instrumental ENSO events from the CEI suggests that the frequency and intensity of post-1970 ENSO events (when 50% of all extreme events identified occur) appears the most anomalous in the context of at least the past century. It is hoped that the CEI will facilitate palaeo-ENSO research to systematically resolve the long-term context of past ENSO behaviour to assess whether the apparently anomalous nature of late twentieth-century variability is unprecedented within existing palaeoclimate archives. Copyright © 2005 Royal Meteorological Society. [source] Optical Emission Spectroscopy Analysis of Ar/N2 Plasma in Reactive Magnetron SputteringPLASMA PROCESSES AND POLYMERS, Issue S1 2009Angélique Bousquet Abstract The ternary silicon carbide-nitride SiCxNy presents very promising properties: hardness, low chemical reactivity, and resistance to oxidation. This material can be deposited by various processes, but reactive magnetron sputtering is one of the most versatile. In this paper, we investigated by optical emission spectroscopy an argon-nitrogen plasma used with a silicon carbide target to deposit SiCxNy films. First, we observed the physical aspect of the discharge is modified not only with the injected atmosphere but also with target surface state, which highly influences the N2 dissociation rate. Then, we followed two species coming from target sputtering: CN and Si. This study confirms the target nitriding up to a certain N2 fraction. Finally, the OES information was related to the deposited film composition. [source] Differences in litter mass change mite assemblage structure on a deciduous forest floorECOGRAPHY, Issue 6 2006Graham H. R. Osler Few mechanisms that determine the assemblage structure of mites have been identified. Whilst the relative abundance of soil fauna is known to change with humus form, the degree to which the quantity of litter inputs play a part in these changes has not been investigated. We tested the response of oribatid and mesostigmatid mites in litter and soil layers to increasing levels of birch Betula pubescens litter to test whether litter mass could affect the mite assemblage. Six litter treatments (1, 2, 4, 8 and 12×natural litter mass and complete litter removal) were established in November 2004 and the soil and litter communities sampled in October 2005. Species composition of oribatids was distinct for the soil and litter. There was no apparent effect of increasing litter mass on the soil mite assemblage. In the litter layer, the number of oribatids g,1 of litter showed a strong negative relationship with increasing litter mass whilst the number of mesostigmatids g,1 of litter was unresponsive to litter mass. Hence, the relative abundance of these two groups altered with increasing litter mass. The response of the oribatid groups Oppiidae and Poronota followed this negative relationship with litter mass but Phthiracaridae appeared less affected. Consequently, there was a subtle shift in the relative abundance of these groups with increasing litter mass. Our results demonstrate that oribatids as a whole and within groups respond in a predictable manner to increases in litter mass whilst mesostigmatids are unresponsive. Whilst there are undoubtedly biological and physical aspects that vary with litter mass, litter mass itself, is able to explain some patterns in the assemblage of oribatid mites. [source] The Influence of Comorbid Depression on Seizure SeverityEPILEPSIA, Issue 12 2003Joyce A. Cramer Summary:,Purpose: To determine the relation between depressive symptoms and seizure severity among people with epilepsy. Methods: A postal questionnaire was used to survey a nationwide community sample about seizures and depression. The Seizure Severity Questionnaire (SSQ) assessed the severity and bothersomeness of seizure components. The Centers for Epidemiological Studies-Depression scale categorized levels of depression. Results: Respondents categorized as having current severe (SEV, n = 166), mild,moderate (MOD, n = 74), or no depression (NO, n = 443) differed significantly in SSQ scores (all p < 0.0001). People with SEV or MOD reported significantly worse problems than did those with NO depression for overall seizure recovery (mean, 5.3, 4.9, 4.5, respectively); overall severity (5.0, 4.5, 4.2); and overall seizure bother (5.3, 4.8, 4.4) (all p < 0.005). Cognitive, emotional, and physical aspects of seizure recovery also were rated worse among people with SEV than with NO depression (all p < 0.05). Symptoms of depression were significantly correlated with higher levels of all components of generalized tonic,clonic seizure severity (r = 0.33,0.48; all p < 0.0001), and partial seizures (r = 0.31,0.38; all p < 0.01). Conclusions: Clinically depressed people with epilepsy reported higher levels of perceived severity and bother from seizures, as well as greater problems with overall seizure recovery than did nondepressed people experiencing similar types of seizures. The pervasive influence of depressive symptoms on reports of seizure activity suggests that people with epilepsy should be screened for depression. These data highlight the importance of detecting and treating depression among people with epilepsy. [source] EORTC QLQ-C30 and FACT-BMT for the measurement of quality of life in bone marrow transplant recipients: a comparisonEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 2 2000Martin Kopp Abstract: The purpose of the study was to compare two differentquality-of-life self-rating instruments, namely the EORTC QLQ-C30, developed by the quality-of-life study group of the European Organisation for Research and Treatment of Cancer, and the FACT-BMT (version 3), the Functional Assessment of Cancer Therapy , Bone Marrow Transplantation scale, which is the FACT-G(eneral measure) in combination with a module developed specifically for evaluating quality of life of bone marrow transplant (BMT) patients. Fifty-six BMT recipients completed both the EORTC QLQ-C30 and the FACT-BMT (German language version) during the same session. Questionnaire data were analyzed on a subscale basis using correlation analysis and multiple linear regression. Correlations between corresponding subscales of EORTC QLQ-C30 and the FACT-BMT ranged from r=0.30 for the emotional domain (poor agreement) to r=0.77 for global QOL (good agreement). This suggests that the instruments, despite considerable overlap, possibly focus on different aspects of QOL, in particular in addressing emotional and social issues of BMT patients. It appears that the FACT-BMT gives a more comprehensive overview regarding the multidimensional construct of quality of life. The EORTC QLQ-C30 gives more insight into the physical aspects of quality of life and helps to identify symptoms which effectively decrease quality of life from the patient's perspective. The QLQ-C30 might be improved by the incorporation of a BMT-specific module currently under development. We therefore conclude that neither of the two instruments can be replaced by the other in the assessment of QOL of BMT patients and that a direct comparison of results obtained with the two instruments is likely to be misleading. [source] REVIEW: Acute withdrawal, protracted abstinence and negative affect in alcoholism: are they linked?ADDICTION BIOLOGY, Issue 2 2010Markus Heilig ABSTRACT The role of withdrawal-related phenomena in the development and maintenance of alcohol addiction remains under debate. A ,self-medication' framework postulates that emotional changes are induced by a history of alcohol use, persist into abstinence, and are a major factor in maintaining alcoholism. This view initially focused on negative emotional states during early withdrawal: these are pronounced, occur in the vast majority of alcohol-dependent patients, and are characterized by depressed mood and elevated anxiety. This concept lost popularity with the realization that in most patients, these symptoms abate over 3,6 weeks of abstinence, while relapse risk persists long beyond this period. More recently, animal data have established that a prolonged history of alcohol dependence induces more subtle neuroadaptations. These confer altered emotional processing that persists long into protracted abstinence. The resulting behavioral phenotype is characterized by excessive voluntary alcohol intake and increased behavioral sensitivity to stress. Emerging human data support the clinical relevance of negative emotionality for protracted abstinence and relapse. These developments prompt a series of research questions: (1) are processes observed during acute withdrawal, while transient in nature, mechanistically related to those that remain during protracted abstinence?; (2) is susceptibility to negative emotionality in acute withdrawal in part due to heritable factors, similar to what animal models have indicated for susceptibility to physical aspects of withdrawal?; and (3) to what extent is susceptibility to negative affect that persists into protracted abstinence heritable? [source] A new index of habitat alteration and a comparison of approaches to predict stream habitat conditionsFRESHWATER BIOLOGY, Issue 10 2007BRIAN FRAPPIER Summary 1. Stream habitat quality assessment complements biological assessment by providing a mechanism for ruling out habitat degradation as a potential stressor and provides reference targets for the physical aspects of stream restoration projects. This study analysed five approaches for predicting habitat conditions based on discriminant function, linear regressions, ordination and nearest neighbour analyses. 2. Quantitative physical and chemical habitat and riparian conditions in minimally-impacted streams in New Hampshire were estimated using United States Environmental Protection Agency's Environmental Monitoring and Assessment Program protocols. Catchment-scale descriptors were used to predict segment-scale stream channel and riparian habitat, and the accuracy and precision of the different modelling approaches were compared. 3. A new assessment index comparing and summarizing the degree of correspondence between predicted and observed habitat based on Euclidean distance between the standardized habitat factors is described. Higher index scores (i.e. greater Euclidean distance) would suggest a greater deviation in habitat between observed conditions and expected reference conditions. As in most biotic indices, the range in index scores in reference sites would constitute a situation equivalent to reference conditions. This new index avoids the erroneous prediction of multiple, mutually exclusive habitat conditions that have confounded previous habitat assessment approaches. 4. Separate linear regression models for each habitat descriptor yielded the most accurate and precise prediction of reference conditions, with a coefficient of variation (CV) between predictions and observations for all reference sites of 0.269. However, for a unified implementation in regions where a classification-based approach has already been taken for biological assessment, a discriminant analysis approach, that predicted membership in biotic communities and compared the mean habitat features in the biotic communities with the observed habitat features, was similar in prediction accuracy and precision (CV = 0.293). 5. The best model had an error of 27% of the mean index value for the reference sites, indicating substantial room for improvement. Additional catchment characteristics not readily available for this analysis, such as average rainfall or winter snow-pack, surficial geological characteristics or past land-use history, may improve the precision of the predicted habitat features in the reference streams. Land-use history in New Hampshire and regional environmental impacts have greatly impacted stream habitat conditions even in streams considered minimally-impacted today; thus as regional environmental impacts change and riparian forests mature, reference habitat conditions should be re-evaluated. [source] On MILES based on flux-limiting algorithms,INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 10-11 2005F. F. Grinstein Abstract Non-classical large eddy simulation (LES) approaches based on using the unfiltered flow equations instead of the filtered ones have been the subject of considerable interest during the last decade. In the monotonically integrated LES (MILES) approach, flux-limiting schemes are used to emulate the characteristic turbulent flow features in the high-wave number end of the inertial subrange region. Mathematical and physical aspects of implicit sub grid scale modelling using nonlinear flux-limiters are conveniently addressed using the modified LES-equation formalism. In this study, the performance of MILES is demonstrated as a function of the flux-limiting scheme in selected representative case studies. Published in 2005 by John Wiley & Sons, Ltd. [source] The importance of ,knowing the patient': community nurses' constructions of quality in providing palliative careJOURNAL OF ADVANCED NURSING, Issue 4 2000Karen A. Luker PhD BNurs RGN RHV NDNCert The importance of ,knowing the patient': community nurses' constructions of quality in providing palliative care This paper reports findings from a study conducted in one community health care trust where 62 members of the district nursing team (grades B,H) were interviewed. An adaptation of the critical incident technique was used to determine factors which contributed or detracted from high quality care for a number of key areas including palliative care. The centrality of knowing the patient and his/her family emerged as an essential antecedent to the provision of high quality palliative care. Factors enabling the formation of positive relationships were given prominence in descriptions of ideal care. Strategies used to achieve this included establishing early contact with the patient and family, ensuring continuity of care, spending time with the patient and providing more than the physical aspects of care. The characteristics described by the community nurses are similar to those advocated in ,new nursing' which identifies the uniqueness of patient needs, and where the nurse,patient relationship is objectified as the vehicle through which therapeutic nursing can be delivered. The link with ,new nursing' emerges at an interesting time for community nurses. The past decade has seen many changes in the way that community nursing services are configured. The work of the district nursing service has been redefined, making the ideals of new nursing, for example holism, less achievable than they were a decade ago. This study reiterates the view that palliative care is one aspect of district nursing work that is universally valued as it lends itself to being an exemplar of excellence in terms of the potential for realizing the ideals of nursing practice. This is of increasing importance in the context of changes that militate against this ideal. [source] Endovenous laser therapy , application studies and latest investigationsJOURNAL OF BIOPHOTONICS, Issue 5-6 2010Ronald Sroka Abstract Endovenous laser therapy (ELT) was introduced in clinical practice as a therapy for incompetent veins about ten years ago. One characteristic of ELT is the broad spectrum of different treatment protocols by means of a variety of laser systems as well as manifold application forms and dosimetry concepts are under investigations. Clinical results with effective, relatively pain-free occlusion of incompetent varicosis veins have been observed, as well as undesired side effects such as ecchymosis, phlebitis and recanalization. In recent years systematic experimental investigations and the analysis of clinical results have increased the understanding of the interrelation between the clinical and physical aspects, followed to a continuous optimization of ELT. The use of IR wavelengths and radial irradiation concepts, together with continuous moving of the optical fiber seem to reduce possible side effects. This way ELT treatment becomes a more standardized effective method for the treatment of varicose veins. In future controlled randomized studies are required to compare optimized ELT treatment with other endoluminal modalities as well as conventional surgery. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] U-PVC gelation level assessment, part 1: Comparison of different techniquesJOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 3 2006Louise-Anne Fillot Several different gelation assessment methods such as differential scanning calorimetry, capillary rheometry, solvent absorption, wide angle x-ray scattering, transmission electron microscopy, and atomic force microscopy were applied to a typical PVC window profile formulation subjected to various thermomechanical histories. Shear applied during the process could be decomposed into two components: (i) a thermal component corresponding to the self-heating that was generated and (ii) a "mechanical" component associated with a "pure" shearing action deprived of any thermal aspect. Shear sensitivity of the above-mentioned gelation assessment techniques was evaluated by considering both aspects. Gelation levels established by differential scanning calorimetry and capillary rheometry were especially compared, thus allowing a comparison of the two physical aspects evidenced by each technique, i.e., crystallite melting and macromolecular network development. It appeared that as soon as the PVC particulate structure had been fragmented into micronic entities (primary particles) the gelation process was governed mainly by the thermal aspect, i.e., crystallite melting. J. VINYL. ADDIT. TECHNOL. 12:98,107, 2006. © 2006 Society of Plastics Engineers. [source] Development of an educational programme for caregivers of people aging with multiple sclerosisOCCUPATIONAL THERAPY INTERNATIONAL, Issue 1 2008Marcia Finlayson Abstract This article describes a three-phase project to identify and develop an occupational therapy response to the challenges experienced by caregivers of middle-aged and older adults with multiple sclerosis (MS). In Phase 1 302 caregivers of middle-aged and older adults with MS were interviewed by telephone to identify the care-giving challenges they experienced. A total of eight challenges were identified, with the four most prevalent ones including finding and using formal support services, managing the emotional aspects of caregiving, doing the physical aspects of care-giving and dealing with informal supports. In Phase 2 a comprehensive literature review was conducted to identify existing caregiver education programmes that could be used to address these challenges. None of the 21 programmes that were located addressed all of the challenges identified through the Phase 1 interviews. In response, a new five-session psycho-educational group programme entitled ,Meeting the Challenges of MS' was developed in Phase 3. The programme was empirically grounded in Phase 1 findings, and drew on theory to guide group process and sequencing. The findings from Phases 1 and 2 and the resulting programme cannot be generalized to caregivers of younger adults with MS, although the steps taken to develop this programme have the potential for replication with other populations served by occupational therapists. Copyright © 2008 John Wiley & Sons, Ltd. [source] Local and non-local ductile damage and failure modelling at large deformation with applications to engineeringPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003Bob Svendsen Prof. Dr. The numerical analysis of ductile damage and failure in engineering materials is often based on the micromechanical model of Gurson [1]. Numerical studies in the context of the finite-element method demonstrate that, as with other such types of local damage models, the numerical simulation of the initiation and propagation of damage zones is strongly mesh-dependent and thus unreliable. The numerical problems concern the global load-displacement response as well as the onset, size and orientation of damage zones. From a mathematical point of view, this problem is caused by the loss of ellipticity of the set of partial di.erential equations determining the (rate of) deformation field. One possible way to overcome these problems with and shortcomings of the local modelling is the application of so-called non-local damage models. In particular, these are based on the introduction of a gradient type evolution equation of the damage variable regarding the spatial distribution of damage. In this work, we investigate the (material) stability behaviour of local Gurson-based damage modelling and a gradient-extension of this modelling at large deformation in order to be able to model the width and other physical aspects of the localization of the damage and failure process in metallic materials. [source] Polarization anisotropy of X-ray atomic factors and `forbidden' resonant reflectionsACTA CRYSTALLOGRAPHICA SECTION A, Issue 5 2005Vladimir E. Dmitrienko Symmetry and physical aspects of `forbidden' reflections excited by a local polarization anisotropy of the X-ray susceptibility are surveyed. Such reflections are observed near absorption edges where the anisotropy is caused by distortions of the atomic electronic states owing to interaction with neighbouring atoms. As a consequence, they allow for extracting nontrivial information about the resonant atom's local environment and their physical conditions. The unusual polarization properties of the considered reflections are helpful to distinguish them from other types of `forbidden' reflections. When such reflections are excited, it is, for example, possible to determine not only the intrinsic anisotropy of an atomic form factor but also additional anisotropy induced by thermal motion, point defects and/or incommensurate modulations. Even the local `chirality' of atoms in centrosymmetric crystals is accessible. Unsolved key problems and possible future developments are addressed. [source] Simulation of X-ray frames from macromolecular crystals using a ray-tracing approachACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2009Kay Diederichs An algorithm is described which simulates a data set obtained from a protein crystal using the rotation method. The diffraction pattern of an ideal crystal is specified by the orientation of the crystal's cell axes with respect to a specified laboratory coordinate system, the distance between the crystal and the detector, the wavelength and the rotation range per frame. However, a realistic simulation of an experiment additionally requires at least a plausible physical model for crystal mosaicity and beam properties. To explore the physical basis of reflection shape and rocking-curve variation, the algorithm simulates the diffraction of a real crystal composed of mosaic blocks which is illuminated with a beam of given divergence and dispersion. Ray tracing for each reflection leads to reflection shapes and rocking curves that appear realistic. A program implementing the algorithm may be used to reproducibly generate data sets that model different physical aspects (imperfections) of the crystal and the experiment. Certain types of systematic errors of the experimental apparatus may also be simulated. Further applications include teaching and characterization of the properties of data-reduction algorithms. [source] Wine bottle closures: physical characteristics and effect on composition and sensory properties of a Semillon wine 1.AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2 2001Performance up to 20 months post-bottling Abstract A Semillon wine was bottled using 14 different closures: a screw-cap type, two grades of conventional natural cork, two ,technical cork' closures (natural cork with a synthetic component), and 9 closures manufactured from synthetic polymer material. Closure performance was evaluated for physical aspects (e.g. extraction force and energy, change in closure diameter, and ease of closure reinsertion), and for wine composition and sensory properties. Wine under the screw cap closure retained the greatest concentration of sulfur dioxide (SO2) and ascorbic acid and had the slowest rate of browning. For other closures the trend of SO2 loss relative to the screw cap closure was apparent from an early stage of testing, and was most evident in the group of synthetic closures, intermediate in the conventional corks, and least evident in the technical cork closures. The loss of SO2 was in general highly correlated with an increase in wine browning (OD420) and the concentration of SO2 in the wine at six months was a strong predictor of future browning in the wine, particularly after eighteen months. Neither the concentration of dissolved oxygen at bottling (0.6,3.1 mg/L), nor the physical closure measures were predictors of future browning. For several closures upright storage tended to accelerate loss of SO2 from the wine, but in many cases this effect was marginal. The closures differed widely in regard to physical characteristics, and in general synthetic corks appeared least ,consumer-friendly' in terms of extraction forces, energies, and ease of closure re-insertion, but there was a trend for natural cork closures to exhibit larger variability in physical characteristics than technical cork and synthetic closures. Sensory analysis indicated large differences in wine flavour properties, with closures which tended to result in the best retention of free SO2 having wine sensory scores for ,citrus' that were generally high whilst scores for the attributes ,developed'/,oxidised' were low. The situation was reversed for wine under closures that performed poorly in the retention of free SO2. It was found that below a critical level of free SO2 remaining in the wine, closures exhibited substantially higher ,oxidised' aroma. Whilst trichloroanisole-type (TCA) taint was a noticeable problem for some cork and technical cork closures, any plastic-type taint appeared not to be a problem with most synthetic closures. [source] | ||||||||||||||||||||||