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Selected AbstractsDevelopmental profiles for multiple object tracking and spatial memory: typically developing preschoolers and people with Williams syndromeDEVELOPMENTAL SCIENCE, Issue 3 2010Kirsten O'Hearn The ability to track moving objects, a crucial skill for mature performance on everyday spatial tasks, has been hypothesized to require a specialized mechanism that may be available in infancy (i.e. indexes). Consistent with the idea of specialization, our previous work showed that object tracking was more impaired than a matched spatial memory task in individuals with Williams syndrome (WS), a genetic disorder characterized by severe visuo-spatial impairment. We now ask whether this unusual pattern of performance is a reflection of general immaturity or of true abnormality, possibly reflecting the atypical brain development in WS. To examine these two possibilities, we tested typically developing 3- and 4-year-olds and people with WS on multiple object tracking (MOT) and memory for static spatial location. The maximum number of objects that could be correctly tracked or remembered (estimated from the k -statistic) showed similar developmental profiles in typically developing 3- and 4-year-old children, but the WS profile differed from either age group. People with WS could track more objects than 3-year-olds, and the same number as 4-year-olds, but they could remember the locations of more static objects than both 3- and 4-year-olds. Combining these data with those from our previous studies, we found that typically developing children show increases in the number of objects they can track or remember between the ages of 3 and 6, and these increases grow in parallel across the two tasks. In contrast, object tracking in older children and adults with WS remains at the level of 4-year-olds, whereas the ability to remember multiple locations of static objects develops further. As a whole, the evidence suggests that MOT and memory for static location develop in tandem typically, but not in WS. Atypical development of the parietal lobe in people with WS could play a causal role in the abnormal, uneven pattern of performance in WS. This interpretation is consistent with the idea that multiple object tracking engages different mechanisms from those involved in memory for static object location, and that the former can be particularly disrupted by atypical development. [source] Using Design Effects From Previous Cluster Surveys to Guide Sample Size Calculation in Emergency SettingsDISASTERS, Issue 2 2006Reinhard Kaiser Abstract A good estimate of the design effect is critical for calculating the most efficient sample size for cluster surveys. We reviewed the design effects for seven nutrition and health outcomes from nine population-based cluster surveys conducted in emergency settings. Most of the design effects for outcomes in children, and one-half of the design effects for crude mortality, were below two. A reassessment of mortality data from Kosovo and Badghis, Afghanistan revealed that, given the same number of clusters, changing sample size had a relatively small impact on the precision of the estimate of mortality. We concluded that, in most surveys, assuming a design effect of 1.5 for acute malnutrition in children and two or less for crude mortality would produce a more efficient sample size. In addition, enhancing the sample size in cluster surveys without increasing the number of clusters may not result in substantial improvements in precision. [source] The implications of different species concepts for describing biodiversity patterns and assessing conservation needs for African birdsECOGRAPHY, Issue 5 2005Shaun Dillon It has been suggested that switching from the widely used Biological Species Concept to a Phylogenetic Species Concept, would result in the appearance of hitherto neglected patterns of endemism. The problem has mainly been analyzed with respect to endemic taxa and for rather limited geographical regions, but will here be analysed for the entire resident avifauna of sub-Saharan Africa. A database of African bird distributions was re-edited to create two new datasets representing 1572 biological species and 2098 phylogenetic species. Species richness patterns were virtually identical with the two taxonomies, and only subtle changes were found in the geographical variation in range-size rarity sum. However, there were some differences in the most range-restricted species, with increased complexity of long-recognized centres of endemism. Overall, then, the large-scale biogeographic patterns are robust to changes in species concepts. This reflects the aggregated nature of endemism, with certain areas acting as "species pumps" and large intervening areas being characterised by a predominance of widespread species which distribute themselves in accordance with contemporary environmental conditions. The percentages of phylogenetic and threatened species captured in a BSC near-minimum set of 64 grid-cells and a PSC near-maximum set, with the same number of grid-cells, are very similar. [source] Does constrained oviposition influence offspring sex ratio in the solitary parasitoid wasp Venturia canescens?ECOLOGICAL ENTOMOLOGY, Issue 2 2008MARIE METZGER Abstract 1.,In haplodiploid organisms, virgin or sperm-depleted females can reproduce but are constrained to produce only male progeny. According to Godfray's constrained model, when p, the proportion of females constrained to produce only male progeny, is not null in a panmictic population, unconstrained females should bias their sex allocation towards females to compensate for the excess of males. These unconstrained females should be able to adjust the sex ratio in response to local variation of p. 2.,In this paper an experimental approach is used to test the hypotheses of this model in the solitary endoparasitoid Venturia canescens under both field and laboratory conditions. Specifically, it is tested whether unconstrained females use their encounters with conspecifics (either male or female) to estimate p and then adjust their sex ratio accordingly. 3.,As assumed by Godfray's model, constrained females actively search for host patches in the field and under laboratory conditions produce the same number of offspring during their lifetime as unconstrained females. As predicted by the model, unconstrained females produce a sex ratio biased towards females both in the laboratory and in the field. 4.,The results show that this bias is not a response to encounters with conspecifics previous to oviposition. The hypothesis that the bias is due to differential mortality between sexes during ontogeny is also rejected. The proportions of constrained ovipositions estimated in two natural populations explain only a small fraction of the sex ratio bias observed in V. canescens. [source] A landscape theory for food web architectureECOLOGY LETTERS, Issue 8 2008Neil Rooney Abstract Ecologists have long searched for structures and processes that impart stability in nature. In particular, food web ecology has held promise in tackling this issue. Empirical patterns in food webs have consistently shown that the distributions of species and interactions in nature are more likely to be stable than randomly constructed systems with the same number of species and interactions. Food web ecology still faces two fundamental challenges, however. First, the quantity and quality of food web data required to document both the species richness and the interaction strengths among all species within food webs is largely prohibitive. Second, where food webs have been well documented, spatial and temporal variation in food web structure has been ignored. Conversely, research that has addressed spatial and temporal variation in ecosystems has generally ignored the full complexity of food web architecture. Here, we incorporate empirical patterns, largely from macroecology and behavioural ecology, into a spatially implicit food web structure to construct a simple landscape theory of food web architecture. Such an approach both captures important architectural features of food webs and allows for an exploration of food web structure across a range of spatial scales. Finally, we demonstrated that food webs are hierarchically organized along the spatial and temporal niche axes of species and their utilization of food resources in ways that stabilize ecosystems. [source] Legibility evaluation using point-of-regard measurementELECTRICAL ENGINEERING IN JAPAN, Issue 4 2008Daisuke Saito Abstract Web site visibility has become important because of the rapid dissemination of the World Wide Web, and combinations of foreground and background colors are crucial in providing high visibility. In our previous studies, the visibilities of several web-safe color combinations were examined using a psychological method. In those studies, simple stimuli were used because of experimental restriction. In this paper, legibility of sentences on web sites was examined using a psychophysiological method, point-of-regard measurement, to obtain other practical data. Ten people with normal color sensations ranging from ages 21 to 29 were recruited. The number of characters per line in each page was arranged in the same number, and the four representative achromatic web-safe colors, that is, #000000, #666666, #999999, and #CCCCCC, were examined. The reading time per character and the gaze time per line were obtained from point-of-regard measurement, and the normalized with the reading time and the gaze time of the three colors were calculated and compared. It was found that the time of reading and gaze become long at the same ratio when the contrast decreases by point-of-regard measurement. Therefore, it was indicated that the legibility of color combinations could be estimated by point-of-regard measurement. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 35,42, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20612 [source] Endothelial dysfunction in Buerger's disease and its relation to markers of inflammationEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2006M. Joras Abstract Background, Buerger's disease (BD) is a segmental occlusive vascular disease. The aim of this study was to detect functional changes in brachial artery and asymptomatic morphological changes in extra-cranial carotid arteries not affected by the disease process and to assess markers of inflammation and endothelial damage. Materials and methods, Fourteen patients in the remission phase of BD and the same number of age- and sex-matched healthy controls were included in the study. The capability of endothelium-dependent (flow-mediated) and endothelium-independent dilation of the brachial artery and intima-media thickness of the carotid arteries were measured using high-resolution ultrasound. Laboratory parameters of endogenous fibrinolytic activity, inflammation and endothelial dysfunction were also measured. Results, Patients with BD had a diminished capability of endothelium-dependent vasodilation and higher levels of some circulating markers of inflammation, such as leukocytes, C-reactive protein, intercellular adhesion molecule-1 and E-selectin. Intercellular adhesion molecule-1 levels were related to some of the inflammatory markers (sedimentation rate, C-reactive protein, ,2-globulins and fibrinogen), while E-selectin was correlated with decreased endogenous blood fibrinolytic activity. Endothelium-dependent vasodilation was in negative correlation with the relative share of neutrophil granulocytes. There were no significant differences in intima-media thickness between patients with BD and controls. Conclusions, Our study has expressed generalized functional arterial disorder in patients with BD not accompanied by any measurable morphological changes of the carotid arterial wall. Functional deterioration of brachial artery could be related to increased levels of various inflammatory markers , the process which is most probably the basic pathogenetic mechanism of the disease. [source] The Effects of the Absence of Emergency Medicine Residents in an Academic Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 11 2002Daniel French MD Objective: What are the quality effects of an emergency medicine (EM) residency, and the associated 24/7 supervision of residents by faculty, in an academic emergency department (ED)? The authors evaluated activity and quality indicators when there were no EM residents present. The hypothesis of the study was that there was no difference between the patient care provided by faculty supervising EM residents and that with an alternative model without EM residents (AbsenceEMResident). Methods: To support the weekly residency educational program (Thursday), EM residents are not scheduled clinically for a 24-hour period (ConfDay). Emergency medicine resident coverage (mean 62.7 hours) was replaced with incremental faculty and mid-level providers (mean 41.0 hours). This study was limited to adult patients (22,527 visits of 39,190 ED total) for six months (January,June 2001) and compared indicators for ConfDay (n = 23) with all other days (NotConfDay, n = 158). Results: Comparing ConfDay (2,842 visits) with NotConfDay (19,685 visits), there was no difference in mean daily visits, inpatient admissions, intensive care unit admissions, or emergency medical services arrivals. ConfDay decision-to-admit time (333 vs. 313 min, p = 0.03) and length of stay for admissions (490 vs. 445 min, p = 0.000) were longer, with no difference for treat/release patients. There was no difference in the numbers of laboratory or radiology tests, consultations, unscheduled return visits, or patient satisfaction. Conclusion: During the study period, there was no measurable difference for most of the quality indicators studied. The AbsenceEMResident model is less efficient in admitting patients. Faculty supervision results in the same number of laboratory and radiology tests and consultations. Other specialties may consider this model if off-hours care becomes a concern. [source] Long-lasting hippocampal potentiation and contextual memory consolidationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2001Benedetto Sacchetti Abstract In order to ascertain whether there are hippocampal electrophysiological modifications specifically related to memory, exploratory activity and emotional stress, extracellular electrical activity was recorded in hippocampal slices prepared from the brains of male adult rats. Several groups of animals were employed: (i) rats which had freely explored the experimental apparatus (8 min exposure); (ii) rats which had been subjected, in the same apparatus, to a fear conditioning paradigm training entailing the administration of aversive electrical footshocks (8 min exposure); (iii) rats to which the same number of aversive shocks had been administered in the same apparatus, but temporally compressed so as to make difficult the association between painful stimuli and the apparatus (30 s exposure); (iv) naïve rats never placed in the apparatus. Half of the rats from each treatment group were used for retrieval testing and the other half for hippocampal excitability testing. The conditioned freezing response was exhibited for no less than 4 weeks. Hippocampal excitability was measured by means of input,output curves (IOC) and paired-pulse facilitation curves (PPF). Retrieval testing or brain slices preparation were performed at increasing delays after the training sessions: immediately afterwards or after 1, 7 or 28 days. Only the rats subjected to the fear conditioning training exhibited freezing when placed again in the apparatus (retrieval testing). It was found that IOCs, with respect to naïve rats, increased in the conditioned animals up to the 7-day delay. In free exploration animals the IOCs increased only immediately after the training session. In all other rats no modification of the curves was observed. IOC increases do not appear to imply presynaptic transmitter release modifications, because they were not accompanied by PPF modifications. In conclusion, a clear-cut correlation was found between the increase in excitability of the Schaffer collateral,CA1 dendrite synapses and freezing response consolidation. [source] Reduced operant ethanol self-administration and in vivo mesolimbic dopamine responses to ethanol inPKC,-deficient miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2000M. Foster Olive Abstract There is increasing evidence that individual protein kinase C (PKC) isozymes mediate specific effects of ethanol on the nervous system. In addition, multiple lines of evidence suggest that the mesoaccumbens dopamine reward system is critically involved in the rewarding and reinforcing effects of ethanol. Yet little is known about the role of individual PKC isozymes in ethanol reinforcement processes or in regulation of mesolimbic systems. In this study, we report that mice lacking the epsilon isoform of PKC (PKC,) show reduced operant ethanol self-administration and an absence of ethanol-induced increase in extracellular dopamine levels in the nucleus accumbens. PKC, null mice exhibited a 53% decrease in alcohol-reinforced operant responses under basal conditions, as well as following ethanol deprivation. Behavioural analysis revealed that while both genotypes had the same number of drinking bouts following deprivation, PKC, null mice demonstrated a 61% reduction in number of ethanol reinforcers per bout and a 57% reduction in ethanol-reinforced response rate. In vivo microdialysis experiments showed that, in contrast to wild-type mice, PKC, null mice exhibited no change in extracellular levels of dopamine in the nucleus accumbens following acute administration of ethanol (1 and 2 g/kg i.p.), while mesolimbic dopamine responses to cocaine (20 mg/kg i.p.) or high potassium (100 m m) in these mice were comparable with that of wild-types. These data provide further evidence that increases in extracellular mesolimbic dopamine levels contribute to the reinforcing effects of ethanol, and indicate that pharmacological agents inhibiting PKC, may be useful in the treatment of alcohol dependence. [source] Effects of the nature and concentration of substrates in aqueous solutions on the solubility of aroma compoundsFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2005Marco Covarrubias-Cervantes Abstract The solubility of nine aroma compounds (acetone, 2-butanone, 2-hexanone, 2-octanone, ethyl acetate, ethyl butanoate, ethyl hexanoate, n -hexanal, and n -hexanol) in both water and various aqueous solutions was measured at 25 °C using the mutual solubility method. The aqueous solutions consisted of sucrose, glucose, sorbitol, glycerol, polyethylene glycol 200, or maltodextrins at different concentrations. Aroma solubility in water decreased with increased hydrophobicity. For aroma molecules which have the same number of carbon atoms in their structure, aqueous solubility decreased as follows: aldehyde > methyl ketone > alcohol > ethyl ester. When using a group contribution method, the estimated solubility of ethyl esters and methyl ketones in water was, respectively, underestimated and overestimated. Compared to water, the solubility of the volatile molecules in aqueous solutions was higher in the aqueous polyols solutions than in the carbohydrate solutions, although solubility decreased as substrate concentration increased. Aqueous solutions properties, such as water activity, also in,uenced aroma compound solubility. Copyright © 2004 John Wiley & Sons, Ltd. [source] DNA repair polymorphisms associated with cytogenetic subgroups in B-cell chronic lymphocytic leukemia,GENES, CHROMOSOMES AND CANCER, Issue 9 2009Christina Ganster Genetic polymorphisms in DNA repair genes can affect the risk of developing different forms of cancer. Therefore, we have studied the putative association of seven single nucleotide polymorphisms (SNPs) in five DNA repair genes with the incidence of chronic lymphocytic leukemia (CLL). We included 461 CLL patients and the same number of age- and sex-matched controls. As chromosomal aberrations are important prognostic markers in CLL, we additionally correlated the SNPs with the occurrence of favorable and unfavorable cytogenetic aberrations in CLL patients. Patients with del(13q) as a sole aberration were allocated to the favorable cytogenetic risk group, and patients with del(17p) and/or del(11q) to the unfavorable cytogenetic risk group. All investigated SNPs were equally distributed between patients with the favorable cytogenetic aberration and controls. However, differences were observed in the distribution of rs13181 in ERCC2 between all CLL patients and controls. Moreover, the clearest differences were found for rs13181 in ERCC2 and rs25487 in XRCC1 between CLL patients with unfavorable cytogenetic aberrations and controls. These data suggest that inborn genetic polymorphisms may predict the outcome of CLL. © 2009 Wiley-Liss, Inc. [source] Optimal designs for estimating penetrance of rare mutations of a disease-susceptibility geneGENETIC EPIDEMIOLOGY, Issue 3 2003Gail Gong Abstract Many clinical decisions require accurate estimates of disease risks associated with mutations of known disease-susceptibility genes. Such risk estimation is difficult when the mutations are rare. We used computer simulations to compare the performance of estimates obtained from two types of designs based on family data. In the first (clinic-based designs), families are ascertained because they meet certain criteria concerning multiple disease occurrences among family members. In the second (population-based designs), families are sampled through a population-based registry of affected individuals called probands, with oversampling of probands whose families are more likely to segregate mutations. We generated family structures, genotypes, and phenotypes using models that reflect the frequencies and penetrances of mutations of the BRCA1/2 genes. We studied the effects of risk heterogeneity due to unmeasured, shared risk factors by including risk variation due to unmeasured genotypes of another gene. The simulations were chosen to mimic the ascertainment and selection processes commonly used in the two types of designs. We found that penetrance estimates from both designs are nearly unbiased in the absence of unmeasured shared risk factors, but are biased upward in the presence of such factors. The bias increases with increasing variation in risks across genotypes of the second gene. However, it is small compared to the standard error of the estimates. Standard errors from population-based designs are roughly twice those from clinic-based designs with the same number of families. Using the root-mean-square error as a measure of performance, we found that in all instances, the clinic-based designs gave more accurate estimates than did the population-based designs with the same numbers of families. Rough variance calculations suggest that clinic-based designs give more accurate estimates because they include more identified mutation carriers. Genet Epidemiol 24:173,180, 2003. © 2003 Wiley-Liss, Inc. [source] Eutectic Gallium-Indium (EGaIn): A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature,ADVANCED FUNCTIONAL MATERIALS, Issue 7 2008Michael D. Dickey Abstract This paper describes the rheological behavior of the liquid metal eutectic gallium-indium (EGaIn) as it is injected into microfluidic channels to form stable microstructures of liquid metal. EGaIn is well- ;suited for this application because of its rheological properties at room temperature: it behaves like an elastic material until it experiences a critical surface stress, at which point it yields and flows readily. These properties allow EGaIn to fill microchannels rapidly when sufficient pressure is applied to the inlet of the channels, yet maintain structural stability within the channels once ambient pressure is restored. Experiments conducted in microfluidic channels, and in a parallel-plate rheometer, suggest that EGaIn's behavior is dictated by the properties of its surface (predominantly gallium oxide, as determined by Auger measurement s); these two experiments both yield approximately the same number for the critical surface stress required to induce EGaIn to flow (,0 .5,N/m). This analysis,which shows that the pressure that must be exceeded for EGaIn to flow through a microchannel is inversely proportional to the critical (i.e., smallest) dimension of the channel,is useful to guide future fabrication of microfluidic channels to mold EGaIn into functional microstructures. [source] Simplified intersubject averaging on the cortical surface using SUMAHUMAN BRAIN MAPPING, Issue 1 2006Brenna D. Argall Abstract Task and group comparisons in functional magnetic resonance imaging (fMRI) studies are often accomplished through the creation of intersubject average activation maps. Compared with traditional volume-based intersubject averages, averages made using computational models of the cortical surface have the potential to increase statistical power because they reduce intersubject variability in cortical folding patterns. We describe a two-step method for creating intersubject surface averages. In the first step cortical surface models are created for each subject and the locations of the anterior and posterior commissures (AC and PC) are aligned. In the second step each surface is standardized to contain the same number of nodes with identical indexing. An anatomical average from 28 subjects created using the AC,PC technique showed greater sulcal and gyral definition than the corresponding volume-based average. When applied to an fMRI dataset, the AC,PC method produced greater maximum, median, and mean t -statistics in the average activation map than did the volume average and gave a better approximation to the theoretical-ideal average calculated from individual subjects. The AC,PC method produced average activation maps equivalent to those produced with surface-averaging methods that use high-dimensional morphing. In comparison with morphing methods, the AC,PC technique does not require selection of a template brain and does not introduce deformations of sulcal and gyral patterns, allowing for group analysis within the original folded topology of each individual subject. The tools for performing AC,PC surface averaging are implemented and freely available in the SUMA software package. Hum Brain Mapp, 2005. © 2005 Wiley-Liss, Inc. [source] Body condition, growth rates and diet of Skylark Alauda arvensis nestlings on lowland farmlandIBIS, Issue 3 2001PAUL F. DONALD Factors affecting the diet, body condition and growth rates of Skylark chicks were assessed to examine their relationship to their agricultural environment during a critical period in the life cycle of this rapidly declining species. Rainfall explained the greatest amount of variation in body condition and growth rates and had a negative effect on both. Body condition indices were a good predictor of the likelihood of future partial brood loss to starvation. Low body condition in grass fields was related to a low diversity in the diet. Chicks fed insect larvae had higher body condition indices than those not fed larvae. Larger broods tended to have higher growth rates than smaller ones, whereas smaller broods tended to have higher body condition indices. Natural brood size reduction through the non-hatching of eggs resulted in higher body condition indices than were found in nests with the same number of chicks where all eggs hatched, this effect being independent of absolute brood size. There was no significant difference between crop types in the distance adult birds flew to forage for food for nestlings and foraging crop destination had no effect on chick development. Differences between crop types in chick diet could be related to the documented effects of pesticides on different prey species. We suggest that recent agricultural changes have affected diet and possibly body condition, but that these effects are unlikely to have been an important factor in recent population declines. [source] Histological evaluation of MTA as a root-end filling materialINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2007P. F. E. Bernabé Abstract Aim, To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored. Methodology, Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using anova analysis and Tukey's test. Results, A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls. Conclusions, GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present. [source] Curvature- and displacement-based finite element analyses of flexible slider crank mechanismsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 10 2010Y. L. Kuo Abstract The paper presents the applications of the curvature- and displacement-based finite element methods to flexible slider crank mechanisms. The displacement-based method usually needs more elements or high-degree polynomials to obtain highly accurate solutions. The curvature-based method assumes a polynomial to approximate a curvature distribution, and the expressions are investigated to obtain the displacement and rotation distributions. During the process, the boundary conditions associated with displacement, rotation, and curvature are imposed, which leads the great reduction of the number of degrees of freedom that are required. The numerical results demonstrate that the errors obtained by applying the curvature-based method are much smaller than those by applying the displacement-based method, based on the comparison of the same number of degrees of freedom. Copyright © 2008 John Wiley & Sons, Ltd. [source] Sliding mesh algorithm for CFD analysis of helicopter rotor,fuselage aerodynamicsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 5 2008R. Steijl Abstract The study of rotor,fuselage interactional aerodynamics is central to the design and performance analysis of helicopters. However, regardless of its significance, rotor,fuselage aerodynamics has so far been addressed by very few authors. This is mainly due to the difficulties associated with both experimental and computational techniques when such complex configurations, rich in flow physics, are considered. In view of the above, the objective of this study is to develop computational tools suitable for rotor,fuselage engineering analysis based on computational fluid dynamics (CFD). To account for the relative motion between the fuselage and the rotor blades, the concept of sliding meshes is introduced. A sliding surface forms a boundary between a CFD mesh around the fuselage and a rotor-fixed CFD mesh which rotates to account for the movement of the rotor. The sliding surface allows communication between meshes. Meshes adjacent to the sliding surface do not necessarily have matching nodes or even the same number of cell faces. This poses a problem of interpolation, which should not introduce numerical artefacts in the solution and should have minimal effects on the overall solution quality. As an additional objective, the employed sliding mesh algorithms should have small CPU overhead. The sliding mesh methods developed for this work are demonstrated for both simple and complex cases with emphasis placed on the presentation of the inner workings of the developed algorithms. Copyright © 2008 John Wiley & Sons, Ltd. [source] Needs and risks of patients in a state-wide inpatient forensic mental health populationINTERNATIONAL JOURNAL OF MENTAL HEALTH NURSING, Issue 4 2010Ariel Segal ABSTRACT Routine needs assessments have become mandated requirements for public mental health services. However, the appropriateness of these generic health needs assessments to specialist populations remains questionable. This study sought to assess individual needs assessed using a widely used clinician rated assessment (Health of the Nation Outcome Scales-Secure; HoNOS-Secure), a subjective needs assessment that considers both staff and patient perspectives (Camberwell Assessment of Need-Forensic version; CANFOR), and a measure of risk for general criminal recidivism (Level of Service Inventory: Screening Version; LSI:SV) in a secure forensic mental health service. Results revealed significant positive correlations between staff ratings on HoNOS-Secure, CANFOR total needs, and CANFOR met needs scores, but no significant association between CANFOR ratings or HoNOS-Secure ratings and LSI:SV scores. Although patients and staff reported the same number of needs overall according to CANFOR (7.2 vs. 7.5, P > 0.05), patients reported that more of these needs were unmet (3.1 vs. 2.3, P < 0.05). Differences between staff and patient ratings of need suggest that needs assessments should include patient perspectives to facilitate more collaborative and comprehensive care planning. Divergent perspectives between patients and staff may impair patient engagement in treatment and therefore negatively impact on outcome. Service planning issues and opportunities for future research are discussed. [source] Synchronization patterns in spaghetti-like nanoclustersINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2008Acep Purqon Abstract Spaghetti-like nanoclusters concern disordered shapes and irregular shape fluctuations in few correlated biological lipids. We evaluate the shape fluctuations by introducing Symmetry- S as a physical parameter for measuring symmetry degrees and detecting shape transitions. From numerical simulation of few correlated lipids of POPC and POPE at 300 K and 340 K by using molecular dynamics, we investigate the symmetry dynamics for each individual cluster by analyzing both spatiotemporal and frequency. From spatiotemporal analysis, we find several jump motions in S -dynamics and non-Gaussian distributions in S -distribution. Interestingly, the jump motions likely contribute on the existence of transitions in the non-Gaussian distributions. Additionally, even number of lipids show more symmetric than the odd number of lipids and the symmetry distributions shift at higher temperature, while, from three dimension of actual position of symmetry dynamics, they are not easy to configure high symmetry as well as showing certain patterns. From power spectra density analysis, each individual cluster shows nearly random fluctuation. Besides individual clusters, we also investigate mutual clusters. Surprisingly, although individual clusters show fluctuations randomly, mutual clusters show certain direction correlations. Moreover, they show certain patterns in delayed time analysis such as mutual fluctuations periodically occur for same number of lipids. It indicates that an existence of synchronization patterns occur in shape fluctuations of spaghetti-like nanoclusters. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [source] The political participation of social workers: a comparative studyINTERNATIONAL JOURNAL OF SOCIAL WELFARE, Issue 2 2002Mel Gray This article reports on a comparative study that examined the political participation of social workers in KwaZulu-Natal province in South Africa, the state of New South Wales (excluding the Hunter region) in Australia, and New Zealand. Each of these contexts had roughly the same number of social workers, that is, approximately 1,200. It was found that social workers in New Zealand tended to be more politically active than their counterparts in New South Wales and KwaZulu-Natal, and the reasons for this are examined. In the process, New Zealand is presented as a case study of the way in which social work has responded to its political context. Finally, conclusions are drawn as to the engagement of social workers in the policy cycle and of the need for them to become more active politically. [source] Ketonization of 1,5-Cyclooctadiene by Nitrous OxideADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Dmitry Abstract The kinetics and mechanism of the liquid phase ketonization of 1,5-cyclooctadiene (COD) by nitrous oxide have been studied. The reaction proceeds without catalyst in the temperature range 473,553,K with the activation energy 113,kJ,mol,1 and is first order with respect to the initial reactants. The mechanism includes consecutive ketonization of two CC bonds in the COD molecule, with the intermediate formation of an unsaturated monoketone (MK). Further ketonization of MK leads to two isomeric diketones (DK): 1,4- and 1,5-cyclooctanedione. The 1,5-DK is a stable final product while the 1,4-DK undergoes further intramolecular aldol transformation leading to two bicyclic compounds, that retain the same number of carbon atoms. The distribution of mono- and diketones in the course of reaction is described by theoretical dependences pointing to identical reactivities of the CC double bonds residing in COD and MK molecules. The ketonization of COD by nitrous oxide exemplifies a prospective way for the preparation of valuable organic products in perfect harmony with the strategy of green chemistry. [source] An educational process to strengthen primary care nursing practices in São Paulo, BrazilINTERNATIONAL NURSING REVIEW, Issue 4 2007A.M. Chiesa rn Objective:, To describe the experience of a registered nurse (RN) training process related to the Family Health Program (FHP) developed in the city of São Paulo, Brazil. Background:, The FHP is a national, government strategy to restructure primary care services. It focuses on the family in order to understand its physical and social structure in regards to the health,illness process. In the FHP, the RN is a member of a team with the same number as medical doctors , an unprecedented situation. The FHP requires a discussion of the RNs' practice, by qualifying and empowering them with tools and knowledge. Methods:, The training process was based on Freire's approach founded on critical pedagogy in order to address the fundamental problem of inequalities in health. The first phase included workshops and the second one included a course. The workshops identified the following problems related to the RN's work: lack of tools to identify the population's needs; overload of work due to the accumulation of management and assistance activities; difficulties regarding teamwork; lack of tools to evaluate the impact of nursing interventions; lack of tools to improve the participation of the community. The course was organized to tackle these problems under five thematic headings. Results:, The RN's training process allowed the group to reflect deeply on its work. This experience led to the need for the construction of tools to intervene in the reality, mainly against social exclusion, rescuing and adapting of the knowledge accumulated in the healthcare practice, identifying settings which demand institutional solutions and engaging the RN in research groups in order to develop projects according to the complexity of the primary care services. Conclusion:, The application of the concept of equity in the health sector represented a reaction against the processes of social exclusion, starting from performance at a local level to become a reality in the accomplishments achieved by the Brazilian National Health System. This training process allowed us to evaluate that partnership, which has produced many concrete results in addressing both parts of the Inequalities in Health dilemma and which is a productive way of building up a new model of health. [source] Foreign Policy Gaps between Citizens and LeadersINTERNATIONAL STUDIES QUARTERLY, Issue 3 2000Benjamin I. Page Persistent gaps between the policy preferences of leaders and those of citizens are problematic from the point of view of democratic theory. Examination of the foreign policy preferences of samples of citizens and leaders from seven Chicago Council on Foreign Relations (CCFR) surveys between 1974 and 1998 reveals many differences of 30, 40, and even 50 percentage points. Often a majority of the public has disagreed with a majority of leaders. Some of the same gaps have persisted over the full 24-year period of these surveys. The pattern of gaps is considerably more complicated than a simple difference in degree of commitment to internationalism. Citizens have generally put a higher priority than leaders on expanding domestic programs like Social Security, crime fighting, and health care, and have been more eager to cut foreign economic aid. But there have not been substantial gaps with respect to defense spending or military aid. More members of the public than leaders emphasize foreign policy goals related to protecting Americans' jobs and ensuring Americans' health and physical security (e.g., from terrorism, drugs, and epidemic diseases). Citizens have been more reluctant than leaders to use U.S. troops in most circumstances, but the opposite is true of situations involving Latin America. Citizens have been more willing to bomb than to commit troops, though not indiscriminately so, and many more citizens than leaders oppose selling weapons abroad. Fewer members of the public than leaders have favored most kinds of cooperative relationships with adversary countries. But more members of the public than leaders generally support the United Nations, and more favor multilateralism in general. About the same number of citizens as leaders have supported NATO. Some of these gaps may reflect lower levels of attention to foreign affairs and lower levels of information among the public than among leaders, but many of the gaps may instead reflect different values and interests. In cases where the public is ill-informed, persistent gaps suggest a failure of leaders to educate and persuade. Where public opinion is well-informed and deliberative, democratic theory would seem to call for responsiveness by policymakers. [source] Time allocation of a parasitoid foraging in heterogeneous vegetation: implications for host,parasitoid interactionsJOURNAL OF ANIMAL ECOLOGY, Issue 5 2007TIBOR BUKOVINSZKY Summary 1Changing plant composition in a community can have profound consequences for herbivore and parasitoid population dynamics. To understand such effects, studies are needed that unravel the underlying behavioural decisions determining the responses of parasitoids to complex habitats. 2The searching behaviour of the parasitoid Diadegma semiclausum was followed in environments with different plant species composition. In the middle of these environments, two Brassica oleracea plants infested by the host Plutella xylostella were placed. The control set-up contained B. oleracea plants only. In the more complex set-ups, B. oleracea plants were interspersed by either Sinapis alba or Hordeum vulgare. 3Parasitoids did not find the first host-infested plant with the same speed in the different environments. Sinapis alba plants were preferentially searched by parasitoids, resulting in fewer initial host encounters, possibly creating a dynamic enemy-free space for the host on adjacent B. oleracea plants. In set-ups with H. vulgare, also, fewer initial host encounters were found, but in this case plant structure was more likely than infochemicals to interfere with the searching behaviour of parasitoids. 4On discovering a host-infested plant, parasitoids located the second host-infested plant with equal speed, demonstrating the effect of experience on time allocation. Further encounters with host-infested plants that had already been visited decreased residence times and increased the tendency to leave the environment. 5Due to the intensive search of S. alba plants, hosts were encountered at lower rates here than in the other set-ups. However, because parasitoids left the set-up with S. alba last, the same number of hosts were encountered as in the other treatments. 6Plant composition of a community influences the distribution of parasitoid attacks via its effects on arrival and leaving tendencies. Foraging experiences can reduce or increase the importance of enemy-free space for hosts on less attractive plants. [source] Apparent inferiority of first-time breeders in the kittiwake: the role of heterogeneity among age classesJOURNAL OF ANIMAL ECOLOGY, Issue 3 2000Emmanuelle Cam Summary 1.,Many studies have provided evidence that first-time breeders have a lower survival, a lower probability of success, or of breeding, in the following year. Hypotheses based on reproductive costs have often been proposed to explain this. However, because of the intrinsic relationship between age and experience, the apparent inferiority of first-time breeders at the population level may result from selection, and experience may not influence performance within each individual. In this paper we address the question of phenotypic correlations between fitness components. This addresses differences in individual quality, a prerequisite for a selection process to occur. We also test the hypothesis of an influence of experience on these components while taking age and reproductive success into account: two factors likely to play a key role in a selection process. 2.,Using data from a long-term study on the kittiwake, we found that first-time breeders have a lower probability of success, a lower survival and a lower probability of breeding in the next year than experienced breeders. However, neither experienced nor inexperienced breeders have a lower survival or a lower probability of breeding in the following year than birds that skipped a breeding opportunity. This suggests heterogeneity in quality among individuals. 3.,Failed birds have a lower survival and a lower probability of breeding in the following year regardless of experience. This can be interpreted in the light of the selection hypothesis. The inferiority of inexperienced breeders may be linked to a higher proportion of lower-quality individuals in younger age classes. When age and breeding success are controlled for, there is no evidence of an influence of experience on survival or future breeding probability. 4.,Using data from individuals whose reproductive life lasted the same number of years, we investigated the influence of experience on reproductive performance within individuals. There is no strong evidence that a process operating within individuals explains the improvement in performance observed at the population level. [source] Null model analysis of communities on gradientsJOURNAL OF BIOGEOGRAPHY, Issue 6 2004James G. Sanderson Abstract Aim, I employed a novel null model and metric to uncover unusual species co-occurrence patterns in a herpetofaunal assemblage of 49 species collected at discrete elevations along a gradient. Location, Mount Kupe, Cameroon. Methods, Using a construction algorithm that started from a matrix of 0s, a sample null space of 25,000 unique null matrices was generated by simultaneously conserving (1) the number of occurrences of each species, (2) site richness and (3) species range spans derived from the observed incidence matrix. I then compared the number of times each pair of confamilial species co-occurred in the null space with the same number derived from the observed incidence matrix. Two cases dealing with embedded absences in species ranges were tested: (1) embedded absences were maintained, and (2) embedded absences were assumed to be sampling omissions and were replaced by presences. Results, In the observed absence/presence assemblage there were 147 possible confamilial species pairs. Therefore, 5% or eight were expected by chance alone to have co-occurrence patterns that differed from chance expectations by chance alone. Of these confamilial species pairs, 38 were congeneric and so 5% or two were expected to differ from chance expectations. For case (1) 16, and for case (2) 17 confamilial species pairs' co-occurrence patterns differed significantly from chance expectations. For case (1) nine congeneric species pairs, and for case (2) 10 congeneric pairs differed significantly from chance expectations. For case (1) four, and for case (2) five congeneric species pairs formed checkerboards (patterns of mutual exclusion). Results from case (1) were a proper subset of case (2) indicating that sampling omissions did not alter greatly the results. Main conclusions, I have demonstrated that null models are valuable tools to analyse ecological communities provided that proper models are employed. The choice of the appropriate null space to analyse distributions is critical. The null model employed to analyse birds on islands of an archipelago can be adapted to analyse species along gradients provided an additional range constraint is added to the null model. Moreover, added precision to results can be obtained by analysing each species pair separately, particularly those in the same family or genus, as opposed to applying a community-wide metric to the faunal assemblage. My results support some of the speculations of previous authors who were unable to demonstrate their suspicions analytically. [source] Alterations of liver function test in patients treated with antipsychoticsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2003M. Teresa Garcia-Unzueta Abstract The prevalence of alterations of liver function tests in patients treated with a wide range of antypsychotics is unknown. The aim of this study was to analyze the effects of antipsychotics on liver function tests in a population of schizophrenic outpatients. Concentrations of AST, ALT, GGT, alkaline phosphatase, albumin, and bilirubin were determined in 54 patients fitting DSM-IV criteria of schizophrenia, and the same number of sex- and age-matched healthy subjects. Assessments included the Clinical Global Impression (CGI) and the Positive and Negative Syndrome Scale (PANSS) in addition to treatment related variables. Transaminases concentrations were slightly elevated in study patients compared to healthy controls, but without statistical significance. Alkaline phosphatase showed higher values in schizophrenic patients. Albumin and bilirubin were lower in study patients. Liver function tests abnormalities were found in about 10% of schizophrenic patients treated with antipsychotics. Treatment with depot phenotiazines induces alteration in these tests more frequently than treatment with other antipsychotics. PANSS negative subscale scores directly correlated with alkaline phosphatase and inversely correlated with albumin. A substantial number of patients in treatment with antipsychotic drugs present alterations of liver function tests. Both pharmacological and clinical factors could be related with these alterations. J. Clin. Lab. Anal. 17:216,218, 2003. © 2003 Wiley-Liss, Inc. [source] Dissemination of research in clinical nursing journalsJOURNAL OF CLINICAL NURSING, Issue 2 2008Marilyn H Oermann Aim., The purposes of the study were to describe the extent of research, clinical and evidence-based practice articles published in clinical nursing journals and to explore the communication of research and practice knowledge in the clinical nursing literature using citation analysis. Background., For nursing research to have an impact on clinical practice and build evidence for practice, findings from research must transfer into the clinical practice literature. By analysing the extent of research published in clinical nursing journals, the citations in those articles, and other characteristics of the nursing literature, we can learn more about the linkages between research and practice in nursing. Design., This was a descriptive study of 768 articles and 18901 citations in those articles. Methods., Feature articles were classified into four groups , (i) original research reports; (ii) clinical practice articles (non-data based papers on a clinical topic); (iii) systematic reviews, integrative literature reviews, guidelines and papers describing evidence-based practice; and (iv) others. Each citation was then examined to determine if it was a reference to a research study or to a document on clinical practice. Results., Nearly a third of the articles in clinical nursing journals were reports on research studies; another third addressed clinical practice. Of the 14232 citations analysed in clinical nursing journals, 6142 were to research reports (43·2%) and about the same number of citations were to clinical documents (n = 5844, 41·1%). Medical research articles were cited most frequently , 27·1% of the citations in clinical journal articles. Nursing research articles were only 7·6% of the cited documents in clinical publications. Conclusions., Dissemination of research findings in the clinical nursing literature occurred at two levels: through articles that reported studies of potential value to the nurse's practice and citations to research publications within articles. Relevance to clinical practice., Disseminating research in journals that are geared to clinicians is essential to increase nurses' awareness of research findings that might be relevant to their practice. This study documented that articles in clinical nursing journals disseminated not only information about clinical practice, but also informed readers about research of potential value to the nurse's practice. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||