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Lower Estimates (lower + estimate)
Selected AbstractsA theory for elastic properties of single crystals with microstructure and its application to diffusion induced segregationCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2008T. Blesgen Abstract In this article a general theory for elastically stressed single crystals in the presence of microstructure is presented and an explicit formula for the resulting non-linear stored mechanical energy is obtained. The optimal microstructure under applied stress is characterised and the optimal laminates are identified in 2D. The analysis is based on a sharp lower estimate of the energy that relies on relaxation. The new theory is then used to extend existing models for diffusion induced segregation (DIS) in the case of (Zn,Fe)S single crystals. Numerical simulations based on finite elements are carried out and the results are compared with former computations of the homogeneous case. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Measuring health inequality with realization of potential life years (RePLY)HEALTH ECONOMICS, Issue S1 2009Kam Ki Tang Abstract This paper proposes a new method to measure health inequalities that are caused by conditions amenable to policy intervention. The method is built on a technique that can separate avoidable and unavoidable mortality risks, using world mortality data compiled by the World Health Organization for the year 2000. The new method is applied to data from 191 countries. It is found that controlling for unavoidable mortality risks leads to a lower estimate of health inequality than otherwise, especially for developed countries. Furthermore, although countries with a higher life expectancy at birth tend to have lower health inequality, there are significant variations in health inequalities across countries with the same life expectancy. The results therefore support the WHO's plea for using health inequality as a distinct parameter from the average level of health in assessing the performance of health systems. Copyright © 2009 John Wiley & Sons, Ltd. [source] GENOMIC FEATURES OF COTESIA PLUTELLAE POLYDNAVIRUSINSECT SCIENCE, Issue 2 2003LIU Cai-ling Abstract Polydnavirus was purified from the calyx fluid of Cotesia plutellae ovary. The genomic features of C. plutellae polydnavirus (CpPDV) were investigated. The viral genome consists of at least 12 different segments and the aggregate genome size is a lower estimate of 80kbp. By partial digestion of CpPDV DNA with Bam HI and subsequent ligation with Bam HI-cut plasmid Bluescript, a representative library of CpPDV genome was obtained. [source] The epidemiologic, health-related quality of life, and economic burden of gastrointestinal stromal tumoursJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 6 2007P. Reddy PharmD Summary Background and objectives:, Gastrointestinal stromal tumours (GIST) are uncommon tumours believed to arise from interstitial cells of Cajal or their precursors in the gastrointestinal (GI) tract, accounting for a small percentage of GI neoplasms and sarcomas. Given the recent recognition of GIST as a distinct cancer, as well as new treatment options available today, a review of the epidemiologic, health-related quality of life (HRQL), and economic burden of GIST is timely from a payer, provider and patient perspective and may provide guidance for treatment decision making and reimbursement. Methods:, A systematic literature review of PubMed and five scientific meeting databases, was conducted to identify published studies and abstracts describing the epidemiologic, HRQL and economic impact of GIST. Publications deemed worthy of further review, based on the information available in the abstract, were retrieved in full text. Results and discussion:, Thirty-four publications met the review criteria: 29 provided data on GIST epidemiology, one provided cost data, three reported HRQL outcomes, and one reported cost and HRQL outcomes. The annual incidence of GIST (cases per million) ranged from 6·8 in the USA to 14·5 in Sweden, with an estimated 5-year survival rate of 45,64%. On the Functional Illness of Chronic Therapy-fatigue instrument, GIST patients scored 40·0 compared with 37·6 in anaemic cancer patients (0 = worst; 52 = least fatigue). Total costs over 10 years for managing GIST patients with molecularly targeted treatment was estimated at £47 521,£56 146 per patient compared with £4047,£4230 per patient with best supportive care. Conclusions:, The incidence of GIST appears to be similar by country; the lower estimate in one country could be explained by differences in method of case ascertainment. Data suggest that the HRQL burden of GIST is similar to that with other cancers although this requires further exploration. The value of new therapies in GIST needs to consider not only cost but also anticipated benefits and the unmet medical need in this condition. [source] Obtaining upper bounds of heat kernels from lower boundsCOMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 5 2008Alexander Grigor We show that a near-diagonal lower bound of the heat kernel of a Dirichlet form on a metric measure space with a regular measure implies an on-diagonal upper bound. If in addition the Dirichlet form is local and regular, then we obtain a full off-diagonal upper bound of the heat kernel provided the Dirichlet heat kernel on any ball satisfies a near-diagonal lower estimate. This reveals a new phenomenon in the relationship between the lower and upper bounds of the heat kernel. © 2007 Wiley Periodicals, Inc. [source] Modelflow estimates of cardiac output compared with Doppler ultrasound during acute changes in vascular resistance in womenEXPERIMENTAL PHYSIOLOGY, Issue 4 2010Kenneth S. Dyson We compared Modelflow (MF) estimates of cardiac stroke volume (SV) from the finger pressure-pulse waveform (Finometer®) with pulsed Doppler ultrasound (DU) of the ascending aorta during acute changes in total peripheral resistance (TPR) in the supine and head-up-tilt (HUT) postures. Twenty-four women were tested during intravenous infusion of 0.005 or 0.01 ,g kg,1 min,1 isoprenaline, 10 or 50 ng kg,1 min,1 noradrenaline and 0.3 mg sublingual nitroglycerine. Responses to static hand-grip exercise (SHG), graded lower body negative pressure (LBNP, from ,20 to ,45 mmHg) and 45 deg HUT were evaluated on separate days. Bland,Altman analysis indicated that SVMF yielded lower estimates than SVDU during infusion of 0.01 ,g kg,1 min,1 isoprenaline (SVMF 92.7 ± 15.5 versus SVDU 104.3 ± 22.9 ml, P= 0.03) and SHG (SVMF 78.8 ± 12.0 versus SVDU 106.1 ± 28.5 ml, P < 0.01), while larger estimates were recorded with SVMF during ,45 mmHg LBNP (SVMF 52.6 ± 10.7 versus SVDU 46.2 ± 14.5 ml, P= 0.04) and HUT (SVMF 59.3 ± 13.6 versus SVDU 45.2 ± 11.3 ml, P < 0.01). Linear regression analysis revealed a relationship (r2= 0.41, P < 0.01) between the change in TPR from baseline and the between-methods discrepancy in SV measurements. This relationship held up under all of the experimental protocols (regression for fixed effects, P= 0.46). These results revealed a discrepancy in MF estimates of SV, in comparison with those measured by DU, during acute changes in TPR. [source] Night sampling improves indices used for management of yellow perch in Lake ErieFISHERIES MANAGEMENT & ECOLOGY, Issue 1 2010P. M. KOCOVSKY Abstract, Catch rate (catch per hour) was examined for age-0 and age-1 yellow perch, Perca flavescens (Mitchill), captured in bottom trawls from 1991 to 2005 in western Lake Erie: (1) to examine variation of catch rate among years, seasons, diel periods and their interactions; and (2) to determine whether sampling during particular diel periods improved the management value of CPH data used in models to project abundance of age-2 yellow perch. Catch rate varied with year, season and the diel period during which sampling was conducted as well as by the interaction between year and season. Indices of abundance of age-0 and age-1 yellow perch estimated from night samples typically produced better fitting models and lower estimates of age-2 abundance than those using morning or afternoon samples, whereas indices using afternoon samples typically produced less precise and higher estimates of abundance. The diel period during which sampling is conducted will not affect observed population trends but may affect estimates of abundance of age-0 and age-1 yellow perch, which in turn affect recommended allowable harvest. A field experiment throughout western Lake Erie is recommended to examine potential benefits of night sampling to management of yellow perch. [source] High-involvement work practices and analysts' forecasts of corporate earningsHUMAN RESOURCE MANAGEMENT, Issue 4 2006George S. Benson Research has shown that high-involvement work practices are positively related to corporate financial performance. However, it is unknown if investors are able to use information on high-involvement practices to predict the performance of specific companies. In this study, we examine earnings forecasts for a sample of Fortune 1000 firms and find professional stock analysts consistently underestimated the earnings of firms that made greater use of high-involvement practices during the 1990s. Based on data collected from newspaper articles and annual reports, we argue that these lower estimates resulted from a lack of information on innovative HR practices. Recommendations to managers for disseminating information on and leveraging highinvolvement HR practices are discussed. © 2006 Wiley Periodicals, Inc. [source] Simulating pan-Arctic runoff with a macro-scale terrestrial water balance modelHYDROLOGICAL PROCESSES, Issue 13 2003Michael A. Rawlins Abstract A terrestrial hydrological model, developed to simulate the high-latitude water cycle, is described, along with comparisons with observed data across the pan-Arctic drainage basin. Gridded fields of plant rooting depth, soil characteristics (texture, organic content), vegetation, and daily time series of precipitation and air temperature provide the primary inputs used to derive simulated runoff at a grid resolution of 25 km across the pan-Arctic. The pan-Arctic water balance model (P/WBM) includes a simple scheme for simulating daily changes in soil frozen and liquid water amounts, with the thaw,freeze model (TFM) driven by air temperature, modelled soil moisture content, and physiographic data. Climate time series (precipitation and air temperature) are from the National Centers for Environmental Prediction (NCEP) reanalysis project for the period 1980,2001. P/WBM-generated maximum summer active-layer thickness estimates differ from a set of observed data by an average of 12 cm at 27 sites in Alaska, with many of the differences within the variability (1,) seen in field samples. Simulated long-term annual runoffs are in the range 100 to 400 mm year,1. The highest runoffs are found across northeastern Canada, southern Alaska, and Norway, and lower estimates are noted along the highest latitudes of the terrestrial Arctic in North America and Asia. Good agreement exists between simulated and observed long-term seasonal (winter, spring, summer,fall) runoff to the ten Arctic sea basins (r = 0·84). Model water budgets are most sensitive to changes in precipitation and air temperature, whereas less affect is noted when other model parameters are altered. Increasing daily precipitation by 25% amplifies annual runoff by 50 to 80% for the largest Arctic drainage basins. Ignoring soil ice by eliminating the TFM sub-model leads to runoffs that are 7 to 27% lower than the control run. The results of these model sensitivity experiments, along with other uncertainties in both observed validation data and model inputs, emphasize the need to develop improved spatial data sets of key geophysical quantities (particularly climate time series) to estimate terrestrial Arctic hydrological budgets better. Copyright © 2003 John Wiley & Sons, Ltd. [source] Management implications of the Macquarie Island trophic cascade revisited: a reply to Dowding et al. (2009)JOURNAL OF APPLIED ECOLOGY, Issue 5 2009Dana M. Bergstrom Summary 1. The management of non-indigenous species is not without its complications. In Bergstrom et al.'s (2009) study, we demonstrated that feral cats Felis catus on sub-Antarctic Macquarie Island were exerting top-down control on the feral rabbit Oryctolagus cuniculus population, and that the eradication of the cats led to a substantial increase in rabbit numbers and an associated trophic cascade. 2. Dowding et al. (2009) claim our modelling was flawed for various reasons, but primarily that a reduction in the application of the rabbit control agent, Myxoma virus, coinciding with cat removal, was a major driver of rabbit population release. 3. We explore this proposition (as well as others) by examining rates of Myxoma viral release between 1991 and 2006 (with an attenuation factor for the years, 2003,2006) in association with presence/absence of cats against two estimates of rabbit population size. Myxoma viral release was a significant factor in the lower estimates of rabbit population, but the effect was small, and was not significant for higher rabbit population estimates. By contrast, the presence or absence of cats remained highly significant for both estimates. 4.Synthesis and applications. We re-affirm our position that top-down control of rabbit numbers by cats, prior to their eradication, was occurring on Macquarie Island. Nonetheless, we agree with Dowding et al. (2009) that systems with multiple invasive species represent complex situations that require careful scrutiny. Such scrutiny should occur in advance of, during, and following management interventions. [source] REVISITING INTERVIEW,COGNITIVE ABILITY RELATIONSHIPS: ATTENDING TO SPECIFIC RANGE RESTRICTION MECHANISMS IN META-ANALYSISPERSONNEL PSYCHOLOGY, Issue 4 2007CHRISTOPHER M. BERRY This study revisits the relationship between interviews and cognitive ability tests, finding lower magnitudes of correlation than have previous meta-analyses; a finding that has implications for both the construct and incremental validity of the interview. Our lower estimates of this relationship than previous meta-analyses were mainly due to (a) an updated set of studies, (b) exclusion of samples in which interviewers potentially had access to applicants' cognitive test scores, and (c) attention to specific range restriction mechanisms that allowed us to identify a sizable subset of studies for which range restriction could be accurately accounted. Moderator analysis results were similar to previous meta-analyses, but magnitudes of correlation were generally lower than in previous meta-analyses. Findings have implications for the construct and incremental validity of interviews, and meta-analytic methodology in general. [source] Effect of dielectric screening on the binding energies and diamagnetic susceptibility of a donor in a quantum well wirePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2006M. Latha Abstract The effect of the dielectric screening on donor binding energies in a quantum wire has been estimated. Since the screening function is shown to be significant in a few phenomena like carrier transport, and not so in a few cases like the donor binding energy calculations, five different screening functions have been used in the calculations to see their relative merits. It is observed that the dielectric function obtained by Resta using the Thomas,Fermi approximation not only gives lower estimates of the ionization energies for all well widths (L ), but also is shown to vary very rapidly with L . The other functions used are those of Hermanson and Vinsome & Richardson. Using the results of the variational calculations for the finite barrier problem, the diamagnetic susceptibility of a donor as a function of L has also been estimated. Though experimental results are not available, we have compared our results for Eion with other theoretical estimates available in the literature. The agreement is found to be good. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] An evaluation of the evidence for, and implications of, cytoplasmic nitrate homeostasisPLANT CELL & ENVIRONMENT, Issue 10 2002M. Y. Siddiqi Abstract A review of literature, reporting values of cytoplasmic/cytosolic [NO3,] in plant cells, identified two major areas of disagreement: (1) disparity in the absolute values within the same system, and (2) constancy versus variability in cytoplasmic/cytosolic [NO3,] with varying [NO3,]o. These differences are related to the techniques used by the different authors. Estimates of cytoplasmic [NO3,] by compartmental analysis and by cell fractionation were consistently higher than the estimates by NO3,selective microelectrodes and by techniques based upon in vivo and in vitro nitrate reductase activity (NRA). A model recognizing more than one cytoplasmic ionic pool would satisfactorily reconcile the differences in both aspects, i.e. absolute values and constancy. Compartmental analysis and cell fractionation techniques may measure the amount of NO3, in the cytoplasm as a whole (including organelles); by contrast, NO3, selective microelectrodes and NRA estimate only the cytosolic NO3, and, hence, may result in lower estimates. Thus, variable organellar pool(s) may maintain a constant cytosolic pool as estimated by microelectrodes. However, certain observations remain at odds with the notion of a constant cytosolic [NO3,]. [source] What a difference a year makes: How immediate and anniversary media reports influence judgements about earthquakesASIAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 3 2002Jodie Cowan Research suggests that the content of newspaper and television reports about natural disasters, such as earthquakes, affects people's fatalistic judgements about these disasters. The present paper contains two studies, Study 1 and Study 2. Study 1 examined features in newspaper reports written at two time points following two major earthquakes: immediately after the earthquakes and a year following the earthquakes. These reports showed several features about the earthquakes: in reports immediately after the earthquakes, the reports were concerned about earthquake agency and general damage; and in reports written a year following the earthquakes, the reports portrayed specific damage and lessons. Study 2 examined the influence of these features on students' (n = 160) estimates of the extent of damage, attributions for damage and judgements of the preventability of the damage. With excerpts presenting specific damage and lessons, participants gave lower estimates of damage, judged damage to be more preventable and attributed the damage more to building design than with earthquake agency and general damage descriptions of the same earthquakes. These findings have clear implications for the way the media and civic education programs present information on earthquakes and other disasters. [source] Estimates of effective stress beneath a modern West Antarctic ice stream from till preconsolidation and void ratioBOREAS, Issue 2 2001SLAWEK TULACZYK Preconsolidation stress recorded in subglacial sediments provides important information about subglacial effective stresses. It is commonly used to reconstruct past effective stresses from sediments left after ice retreat. In this article, we use properties of sub-ice-stream till samples to estimate effective stresses beneath a modern West Antarctic ice stream. Two previous estimates of sub-ice-stream effective stress were derived for the Upstream B (UpB) area of Ice Stream B from shear wave velocities (50 ± 40 kPa, Blankenship et al 1987) and borehole water level measurements (63 ± 24 kPa, Engelhardt & Kamb 1997). However, geotechnical tests performed on samples of the UpB till have shown that if subjected to effective stress of 50,63 kPa this till would have significantly lower porosity (,0.32,0.35) and higher strength (,-22,28 kPa) than it apparently has in situ (,0.4 and ,2kPa). We derive new estimates of sub-ice-stream effective stress using: (1) Casagrande's construction applied to the results of six confined uniaxial tests, and (2) a combination of void-ratio data for 51 till samples and 3 experimentally constrained equations describing compressibility of the UpB till under normal consolidation, overconsolidation and in the critical state. Casagrande's method yields an upper bound on effective stress of 25 kPa for four till samples and values of 13, and 4.4kPa for two other samples. The void-ratio approach gives 11.7 ± 2.6 (normal consolidation), 18.3 ± 4.4 (overconsolidation) and 2.0 ± 0.8 kPa (critical state). These new, lower estimates of effective stress are consistent with the low till strength that has been independently measured and inferred from recent theoretical ice-stream models. Our interpretation of data on till void ratio in terms of sub-ice-stream effective stress means that we can qualitatively evaluate the nature of the vertical distribution of this stress in the UpB till layer. We infer that in the sampled top 3 m of till the effective-stress distribution is non-hydrostatic, probably close to lithostatic. The results may be useful in future modeling of ice-stream behavior and may aid efforts to delineate paleo-ice streams based on their geologic record. [source] Physical performance limitations among adult survivors of childhood brain tumorsCANCER, Issue 12 2010Kirsten K. Ness PhD Abstract BACKGROUND: Young adult survivors of childhood brain tumors (BTs) may have late effects that compromise physical performance and everyday task participation. The objective of this study was to evaluate muscle strength, fitness, physical performance, and task participation among adult survivors of childhood BTs. METHODS: In-home evaluations and interviews were conducted for 156 participants (54% men). Results on measures of muscle strength, fitness, physical performance, and participation were compared between BT survivors and members of a population-based comparison group by using chi-square statistics and 2-sample t tests. Associations between late effects and physical performance and between physical performance and participation were evaluated in regression models. RESULTS: The median age of BT survivors was 22 years (range, 18-58 years) at the time of the current evaluation, and they had survived for a median of 14.7 years (range, 6.5-45.9 years) postdiagnosis. Survivors had lower estimates of grip strength (women, 24.7 ± 9.2 kg vs 31.5 ± 5.8 kg; men, 39.0 ± 12.2 kg vs 53.0 ± 10.1 kg), knee extension strength (women, 246.6 ± 95.5 Newtons [N] vs 331.5 ± 5.8 N; men, 304.7 ± 116.4 N vs 466.6 ± 92.1 N), and peak oxygen uptake (women, 25.1 ± 8.8 mL/kg per minute vs 31.3 ± 5.1 mL/kg per minute; men, 24.6 ± 9.5 mL/kg per minute vs 33.2 ± 3.4 mL/kg per minute) than members of the population-based comparison group. Physical performance was lower among survivors and was associated with not living independently (odds ratio [OR], 5.0; 95% confidence interval [CI], 2.0-12.2) and not attending college (OR, 2.3; 95% CI 1.2-4.4). CONCLUSIONS: Muscle strength and fitness values among BT survivors were similar to those among individuals aged ,60 years and were associated with physical performance limitations. Physical performance limitations were associated with poor outcomes in home and school environments. The current data indicated an opportunity for interventions targeted at improving long-term physical function in this survivor population. Cancer 2010. © 2010 American Cancer Society. [source] | ||||||||||||||||||||||