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Several Variables (several + variable)

Distribution by Scientific Domains

Medical Sciences	33%
Life Sciences	20%
Humanities and Social Sciences	15%
Chemistry	12%
6 Other Domains	20%

Selected Abstracts

The Impact of Macroeconomic and Financial Variables on Market Risk: Evidence from International Equity Returns

EUROPEAN FINANCIAL MANAGEMENT, Issue 4 2002
Dilip K. Patro
Using a GARCH approach, we estimate a time,varying two,factor international asset pricing model for the weekly equity index returns of 16 OECD countries. We find significant time,variation in the exposure (beta) of country equity index returns to the world market index and in the risk,adjusted excess returns (alpha). We then explain these world market betas and alphas using a number of country,specific macroeconomic and financial variables with a panel approach. We find that several variables including imports, exports, inflation, market capitalisation, dividend yields and price,to,book ratios significantly affect a country's exposure to world market risk. Similar conclusions are obtained by using lagged explanatory variables, and thus these variables may be useful as predictors of world market risks. Several variables also significantly impact the risk,adjusted excess returns over this time period. Our results are robust to a number of alternative specifications. We further discuss some economic hypotheses that may explain these relationships. [source]

DIEL VARIATIONS IN OPTICAL PROPERTIES OF IMANTONIA ROTUNDA (HAPTOPHYCEAE) AND THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE) EXPOSED TO DIFFERENT IRRADIANCE LEVELS,

JOURNAL OF PHYCOLOGY, Issue 3 2008
Sébastien Mas
Diel variations of cellular optical properties were examined for cultures of the haptophyte Imantonia rotunda N. Reynolds and the diatom Thalassiosira pseudonana (Hust.) Hasle et Heimdal grown under a 14:10 light:dark (L:D) cycle and transferred from 100 ,mol photons · m,2 · s,1 to higher irradiances of 250 and 500 ,mol photons · m,2 · s,1. Cell volume and abundance, phytoplankton absorption coefficients, flow-cytometric light scattering and chl fluorescence, and pigment composition were measured every 2 h over a 24 h period. Results showed that cell division was more synchronous for I. rotunda than for T. pseudonana. Several variables exhibited diel variability with an amplitude >100%, notably mean cell volume for the haptophyte and photoprotective carotenoids for both species, while optical properties such as flow-cytometric scattering and chl a,specific phytoplankton absorption generally showed <50% diel variability. Increased irradiance induced changes in pigments (both species) and mean cell volume (for the diatom) and amplified diel variability for most variables. This increase in amplitude is larger for pigments (factor of 2 or more, notably for cellular photoprotective carotenoid content in I. rotunda and for photosynthetic pigments in T. pseudonana) than for optical properties (a factor of 1.5 for chl a,specific absorption, at 440 nm, in I. rotunda and a factor of 2 for the absorption cross-section and the chl a,specific scattering in T. pseudonana). Consequently, diel changes in optical properties and pigmentation associated with the L:D cycle and amplified by concurrent changes in irradiance likely contribute significantly to the variability in optical properties observed in biooptical field studies. [source]

Influences on Detention Decisions in the Juvenile Justice System

JUVENILE AND FAMILY COURT JOURNAL, Issue 1 2002
BRIAN F. O'NEILL MSW, PH.D.
ABSTRACT This paper examines the pretrial detention of juveniles in County X located in a northeastern state. The sample (N=642) included Black, White, and Hispanic males and females adjudicated delinquent in the summer of 2000. The following independent variables were analyzed with respect to the dependent variable of pretrial detention: age, sex, address, race, current offense (misdemeanors, violent misdemeanors, felonies, violent felonies, and probation violations), prior offense (misdemeanors, violent misdemeanors, felonies, and violent felonies), and previous dispositions (community or placement). Several variables were found to be significant in increasing the odds of pretrial detention: probation violations, prior misdemeanors, prior residential placements, prior community interventions, age, sex, urban address, felonies, prior violent misdemeanors, and prior violent felonies. It was expected that minority youths would be more likely to be detained, but race was only significant in the absence of the variable of address. Urban youths were more likely to be detained resulting in an over-representation of minorities in detention, since most of the minority population resides in the urban area. Also included is supplemental material based on interviews with defense lawyers, judges, masters, and juvenile probation officers. [source]

A new method for estimating age-at-death from the first rib,

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009
Elizabeth A. DiGangi
Abstract A new method for estimating adult age-at-death from the first rib was developed as a modification of the Kunos et al. (Am J Phys Anthropol 110 (1999) 303,323) method. Data were collected on three aspects of the first rib (costal face, rib head, and tubercle facet) for 470 known-age males of Balkan ancestry collected as evidence during investigations conducted by the International Criminal Tribunal for the former Yugoslavia (ICTY). Ages-at-death range from 12 to 90 years (mean of 47.7 years). Several variables were extracted from the original study utilizing all three skeletal aspects of the first rib. This list was modified to 11 variables as preliminary tests on seriations of the samples were undertaken. A cumulative probit model with age measured on a log scale was used to calculate the mean and standard deviation of the ages-of-transition for each component. Multivariate analysis of the three components was also performed. The lowest correlation (r = 0.079, controlling for age) was between the geometric shape of the costal face and the surface texture of the tubercle facet. Assuming a correlation of zero, these two traits were used to calculate the highest posterior density regions for estimating individual ages-at-death. Age-at-death estimates generated from 50 and 95% posterior density regions indicate that this method captures age-related change reaching the ninth decade. The Bayesian statistical approach used here produced a valuable and promising new method for estimating age-at-death. Additional research is necessary to determine if these highest posterior density regions produce results highly correlated with age in other samples and its applicability to females. Am J Phys Anthropol 2009. © 2008 Wiley-Liss, Inc. [source]

Rheological determinants of red blood cell aggregation in diabetic patients in relation to their metabolic control

DIABETIC MEDICINE, Issue 2 2002
K. Elishkevitz
Abstract Aims To determine whether increased red blood cell adhesiveness/aggregation in diabetic patients is related to the extent of their metabolic control. Methods We measured erythrocyte adhesiveness/aggregation in a group of 85 adult patients with diabetes mellitus by using citrated venous whole blood and a simple slide test. The erythrocyte adhesiveness/aggregation was determined by measuring the size of the spaces that are formed between the aggregated erythrocytes. We divided the patients into those with either low or high erythrocyte adhesiveness/aggregation values. Results The erythrocyte adhesiveness/aggregation values of the two groups differed significantly in terms of their fibrinogen concentration, erythrocyte sedimentation rate, high sensitive C-reactive protein (CRP), total cholesterol and triglyceride concentrations. There was no difference between the two groups regarding the concentrations of HbA1c. Logistic regression was applied to construct a model to predict the belonging of a patient in the low or high erythrocyte adhesiveness/aggregation group. A linear regression was applied to construct a model to predict the erythrocyte adhesiveness/aggregation values. Both models turned out to include gender, age, fibrinogen, triglyceride, retinopathy, coronary artery disease and age and gender interaction. Neither HbA1c nor CRP entered the models. Conclusions The degree of erythrocyte adhesiveness/aggregation and several variables of the acute-phase response in patients with diabetes mellitus are not directly related to the degree of metabolic control as evaluated by means of HbA1c concentration. Diabetic patients might benefit from rheological or anti-inflammatory interventions regardless of their metabolic control. [source]

The effects of fluvial processes and habitat heterogeneity on distribution, growth and densities of juvenile Atlantic salmon (Salmo salar L.), with consequences on abundance of the adult fish

ECOLOGY OF FRESHWATER FISH, Issue 4 2002
R. J. Gibson
Abstract,,,The required freshwater habitats of juvenile Atlantic salmon (Salmo salar) are, in general, well known, but vary in quality, related to interacting effects of several variables, which may depend on different parts of a river system. Examples are given of ranges of densities and growth that can be found at various sites in eastern Canada, illustrating the biological and physico-chemical factors affecting production of juvenile salmon. Relative growth rates can indicate habitat quality and population densities. Salmon parr have negative effects on brook trout in riffle habitats. The effects of migrations within the river and of changes with stream succession on juvenile salmon production are illustrated with examples from a Newfoundland river. Migration of age-classes can be quantified from ,self-thinning' curves. Lakes have enhancing effects on downstream fluvial habitats, and, at least in Newfoundland, and probably in many boreal areas, the lacustrine proportion of the basin can be used as an index for deriving estimates of required spawning escapement. The factors described should be taken into account for more refined estimates of river production and management of the salmon resource. [source]

The Impact of Macroeconomic and Financial Variables on Market Risk: Evidence from International Equity Returns

Frailty predicts long-term mortality in elderly subjects with chronic heart failure

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2005
F. Cacciatore
Abstract Background, The elderly are characterized by a high prevalence of chronic heart failure (CHF) and frailty, which is a complex interaction of physical, psychological and social impairment. This study aimed to examine the predictive role of frailty on long-term mortality in elderly subjects with CHF. Materials and methods, The study assessed long-term mortality after 12-year follow up in 120 subjects with CHF and 1139 subjects without CHF, selected in 1992, from a random sample of the elderly population in the Campania region of Italy. Frailty was assessed according to a ,Frailty Staging System'. Results, Subjects with CHF were prevalently female (60%) and older than 75 years (mean 75·9 ± 6·7); subjects without CHF were prevalently female (56·4%) and younger than 75 years (mean 74·0 ± 6·3). In subjects with and without CHF stratified into classes of frailty there was a statistically significant increase in age, comorbidity, disability and low social support, and a decrease in MMSE score. Moreover, death progressively increased more with frailty in subjects (70·0% to 94·4%, P < 0·03) than in those without (43·8.% to 88·3%, P < 0·0001) CHF. The Kaplan,Meier analysis shows that at 9 years the probability of survival progressively decreased as frailty increased (45·5% to 0%) in subjects with CHF and from 62·8% to 25·9% in subjects without CHF. The Cox regression analysis indicated that frailty is predictive of mortality in the multivariate model adjusted for several variables including sex and age in subjects with and without CHF. Moreover, the analysis showed that frailty is more predictive of mortality in elderly subjects with CHF when it was analyzed either as continuous (1·48 vs. 1·36) or as a dummy (3 vs. 1 = 1·62 vs. 1·24) variable. Conclusions, Thus mortality among elderly subjects with or without CHF increases with frailty. Moreover, frailty is more predictive of long-term mortality in elderly subjects with than in those without CHF. Hence, frailty represents a new independent variable for predicting long-term mortality in elderly subjects with CHF. [source]

Effects of afforestation on water yield: a global synthesis with implications for policy

GLOBAL CHANGE BIOLOGY, Issue 10 2005
Kathleen A. Farley
Abstract Carbon sequestration programs, including afforestation and reforestation, are gaining attention globally and will alter many ecosystem processes, including water yield. Some previous analyses have addressed deforestation and water yield, while the effects of afforestation on water yield have been considered for some regions. However, to our knowledge no systematic global analysis of the effects of afforestation on water yield has been undertaken. To assess and predict these effects globally, we analyzed 26 catchment data sets with 504 observations, including annual runoff and low flow. We examined changes in the context of several variables, including original vegetation type, plantation species, plantation age, and mean annual precipitation (MAP). All of these variables should be useful for understanding and modeling the effects of afforestation on water yield. We found that annual runoff was reduced on average by 44% (±3%) and 31% (±2%) when grasslands and shrublands were afforested, respectively. Eucalypts had a larger impact than other tree species in afforested grasslands (P=0.002), reducing runoff (90) by 75% (±10%), compared with a 40% (±3%) average decrease with pines. Runoff losses increased significantly with plantation age for at least 20 years after planting, whether expressed as absolute changes (mm) or as a proportion of predicted runoff (%) (P<0.001). For grasslands, absolute reductions in annual runoff were greatest at wetter sites, but proportional reductions were significantly larger in drier sites (P<0.01 and P<0.001, respectively). Afforestation effects on low flow were similar to those on total annual flow, but proportional reductions were even larger for low flow (P<0.001). These results clearly demonstrate that reductions in runoff can be expected following afforestation of grasslands and shrublands and may be most severe in drier regions. Our results suggest that, in a region where natural runoff is less than 10% of MAP, afforestation should result in a complete loss of runoff; where natural runoff is 30% of precipitation, it will likely be cut by half or more when trees are planted. The possibility that afforestation could cause or intensify water shortages in many locations is a tradeoff that should be explicitly addressed in carbon sequestration programs. [source]

Unravelling the effects of temperature, latitude and local environment on the reproduction of forest herbs

GLOBAL ECOLOGY, Issue 6 2009
P. De Frenne
ABSTRACT Aim, To investigate the effect of temperature, latitude and local environment on the reproductive traits of widespread perennial forest herbs to better understand the potential impacts of rising temperatures on their population dynamics and colonization capacities. Location, Six regions along a latitudinal gradient from France to Sweden. Methods, Within each region, we collected data from three to five populations of up to six species. For each species, several variables were recorded in each region (temperature, latitude) and population (local abiotic and biotic environmental variables), and seed production and germination were estimated. Resource investment in reproduction (RIR) was quantified as seed number × seed mass, while germinable seed output (GSO) was expressed as seed number × germination percentage. We performed linear regression and mixed effect models to investigate the effects of temperature (growing degree hours), latitude and local abiotic and biotic environment on RIR and GSO. Results, Temperature and latitude explained most of the variation in RIR and GSO for early flowering species with a northerly distribution range edge (Anemone nemorosa, Paris quadrifolia and Oxalis acetosella). Reproduction of the more southerly distributed species (Brachypodium sylvaticum, Circaea lutetiana and Primula elatior), in contrast, was independent of temperature/latitude. In the late summer species, B. sylvaticum and C. lutetiana, variation in RIR and GSO was best explained by local environmental variables, while none of the investigated variables appeared to be related to reproduction in P. elatior. Main conclusions, We showed that reproduction of only two early flowering, northerly distributed species was related to temperature. This suggests that the potential reproductive response of forest herbs to climate warming partly depends on their phenology and distribution, but also that the response is to some extent species dependent. These findings should be taken into account when predictions about future shifts in distribution range are made. [source]

Sources of well-being and commitment of staff in the Australian Disability Employment Services

HEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 2 2008
Andrew Noblet PhD
Abstract This study examined the role of working conditions in predicting the psychological health, job satisfaction and organisational commitment of personnel responsible for helping people with disabilities gain employment in the mainstream Australian labour market. The working conditions were assessed using two theories: the Job Strain Model (job demand, social support and job control) and Psychological Contract Theory (unwritten reciprocal obligations between employers and employees). In the case of the Job Strain Model, the generic dimensions had been augmented by industry-specific sources of stress. A cross-sectional survey was undertaken in June and July 2005 with 514 staff returning completed questionnaires (representing a response rate of 30%). Comparisons between respondents and non-respondents revealed that on the basis of age, gender and tenure, the sample was broadly representative of employees working in the Australian disability employment sector at that time. The results of regression analyses indicate that social support was predictive of all of the outcome measures. Job control and the honouring of psychological contracts were both predictive of job satisfaction and commitment, while the more situation-specific stressors , treatment and workload stressors , were inversely related to psychological health (i.e. as concern regarding the treatment and workload stressors increased, psychological health decreased). Collectively, these findings suggest that strategies aimed at combating the negative effects of large-scale organisational change could be enhanced by addressing several variables represented in the models , particularly social support, job control, psychological contracts and sector-specific stressors. [source]

Prediction of hemodialysis sorbent cartridge urea nitrogen capacity and sodium release from in vitro tests

HEMODIALYSIS INTERNATIONAL, Issue 2 2008
Benjamin P. ROSENBAUM
Abstract In sorbent-based hemodialysis, factors limiting a treatment session are urea conversion capacity and sodium release from the cartridge. In vitro experiments were performed to model typical treatment scenarios using various dialyzers and 4 types of SORBÔ sorbent cartridges. The experiments were continued to the point of column saturation with ammonium. The urea nitrogen removed and amount of sodium released in each trial were analyzed in a multi-variable regression against several variables: amount of zirconium phosphate (ZrP), dialysate flow rate (DFR), simulated blood flow rate (BFR), simulated patient whole-body fluid volume (V), initial simulated patient urea concentration (BUNi), dialyzer area permeability (KoA) product, initial dialysate sodium and bicarbonate (HCO3i) concentrations, initial simulated patient sodium (Nai), pH of ZrP, creatinine, breakthrough time, and average urea nitrogen concentration in dialysate. The urea nitrogen capacity (UNC) of various new SORBÔ columns is positively related to ZrP, BFR, V, BUNi, and ZrP pH and negatively to DFR with an R2adjusted=0.990. Two models are described for sodium release. The first model is related positively to DFR and V and negatively to ZrP, KoA product, and dialysate HCO3i with an R2adjusted=0.584. The second model incorporates knowledge of initial simulated patient sodium (negative relationship) and urea levels (negative relationship) in addition to the parameters in the first model with an R2adjusted=0.786. These mathematical models should allow for prediction of patient sodium profiles and the time of column urea saturation based on simple inputs relating to patient chemistries and the dialysis treatment. [source]

Generalized fuzzy quantifiers and the modeling of fuzzy branching quantification

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 6 2009
Ingo Glöckner
Lindström (Theoria, 1966; 32:186,195) introduced a very powerful notion of quantifiers, which permits multiplace quantification and the simultaneous binding of several variables. "Branching" quantification was found to be useful by linguists, e.g., for modeling reciprocal constructions like "Most men and most women admire each other." Westerståhl (In Gärdenfors P., editor. Generalized Quantifiers. New York: Reidel; 1987. pp 269,298) showed how to compute the three-place Lindström quantifier for "Q1As and Q2Bs R each other" from the binary quantifiers Q1 and Q2, assuming crisp quantifiers and arguments. In the paper, this basic method will be generalized to vague quantifiers like "many" and fuzzy arguments like "young." A consistent interpretation is achieved by extending the DFS theory of fuzzy quantification (Glöckner, TR97-06, 1997; TR2002-07, (Int J Approx Reason) 2003; 2004; 37(2):93,126), which introduces fuzzy generalized quantifiers in conformance with the original linguistic notion, and controls their interpretation by formal adequacy criteria. The new analysis is important to linguistic data summarization because the full meaning of reciprocal summarizers (e.g., describing factors, which are "correlated" or "associated" with each other), can only be captured by branching quantification. The proofs of all theorems cited in the paper are listed in (Glöckner, TR2002-07, 2003). © 2009 Wiley Periodicals, Inc. [source]

Gender relations and grass-roots urban movements

INTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 177 2003
François Hainard
This article, based on the work of a network of seven teams from countries of the South and countries in transition, presents research findings on the themes of the environment, cities, and social relationships between men and women. The research is predicated on the view that a crosswise look at these three topics brings a useful new perspective to bear on each of these issues as such. It starts from the twofold observation that women and men are not involved in the same way in the urban environment, and that innovative approaches often emanate from women's movements concerned to change the environmental situation in cities as well as women's place and role in the decision-making process. However, research on urban issues, apart from recent research on employment and the labour market, has turned a blind eye to distinctions between men's and women's needs. The urban environment and gender relations bring into play several variables: the environment, the urban dimension, and gender. While the intermeshing of these approaches undoubtedly constitutes a large part of the originality of the work, it does not make the task any the less complex, for its impact is evident neither in methodological nor in conceptual terms. The personal motivation necessarily built into any research-action presupposes that the analysis is founded on specific experiences and not upon strictly theoretical principles, though the need for conceptual concordance between the different research teams should not be overlooked. We shall here focus on the governance of which women may be the agents or actors in cities, a focus that brings into play the different approaches to empowerment and gender relations in the context of social change, the analysis of grass-roots organisations and of men's and women's identities and roles, and the changing balance of power between men and women, whether in the domestic or the public arena. [source]

Associations of Sexual Victimization, Depression, and Sexual Assertiveness with Unprotected Sex: A Test of the Multifaceted Model of HIV Risk Across Gender

JOURNAL OF APPLIED BIOBEHAVIORAL RESEARCH, Issue 1 2009
Patricia J. Morokoff
This study examined whether the Multifaceted Model of HIV Risk (MMOHR) would predict unprotected sex based on predictors including gender, childhood sexual abuse (CSA), sexual victimization (SV), depression, and sexual assertiveness for condom use. A community-based sample of 473 heterosexually active men and women, aged 18,46 years completed survey measures of model variables. Gender predicted several variables significantly. A separate model for women demonstrated excellent fit, while the model for men demonstrated reasonable fit. Multiple sample model testing supported the use of MMOHR in both men and women, while simultaneously highlighting areas of gender difference. Prevention interventions should focus on sexual assertiveness, especially for CSA and SV survivors, as well as targeting depression, especially among men. [source]

Assessing the suitability of central European landscapes for the reintroduction of Eurasian lynx

JOURNAL OF APPLIED ECOLOGY, Issue 2 2002
Stephanie Schadt
Summary 1After an absence of almost 100 years, the Eurasian lynx Lynx lynx is slowly recovering in Germany along the German,Czech border. Additionally, many reintroduction schemes have been discussed, albeit controversially, for various locations. We present a habitat suitability model for lynx in Germany as a basis for further management and conservation efforts aimed at recolonization and population development. 2We developed a statistical habitat model using logistic regression to quantify the factors that describe lynx home ranges in a fragmented landscape. As no data were available for lynx distribution in Germany, we used data from the Swiss Jura Mountains for model development and validated the habitat model with telemetry data from the Czech Republic and Slovenia. We derived several variables describing land use and fragmentation, also introducing variables that described the connectivity of forested and non-forested semi-natural areas on a larger scale than the map resolution. 3We obtained a model with only one significant variable that described the connectivity of forested and non-forested semi-natural areas on a scale of about 80 km2. This result is biologically meaningful, reflecting the absence of intensive human land use on the scale of an average female lynx home range. Model testing at a cut-off level of P > 0·5 correctly classified more than 80% of the Czech and Slovenian telemetry location data of resident lynx. Application of the model to Germany showed that the most suitable habitats for lynx were large-forested low mountain ranges and the large forests in east Germany. 4Our approach illustrates how information on habitat fragmentation on a large scale can be linked with local data to the potential benefit of lynx conservation in central Europe. Spatially explicit models like ours can form the basis for further assessing the population viability of species of conservation concern in suitable patches. [source]

Association between central venous pressure and blood loss during hepatic resection in 984 living donors

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2009
Y. K. KIM
Background: Although low central venous pressure (CVP) anesthesia has been used to minimize blood loss during hepatectomy, the efficacy of this technique remains controversial. We therefore assessed the association between blood loss and CVP during hepatic resection, and examined significant determinants associated with intraoperative hemorrhage during hepatectomy in living donors. Methods: Between April 2004 and April 2008, 984 living donors who underwent a hepatic resection were assessed retrospectively. Univariate and multivariate analyses were performed to explore the relationships between intraoperative blood loss and several variables including CVP. Results: The mean intraoperative blood loss was 691.3 ± 365.5 ml. Only four donors required packed red blood cell transfusions (mean, 1.5 U). The mean duration of hepatic resection was 92.1 ± 26.3 min. The mean, maximum, and minimum values of CVP measured during hepatectomy were 4.6 ± 1.7, 5.3 ± 1.8, and 4.0 ± 1.8 mmHg, respectively, and were not significantly correlated with intraoperative blood loss. On multivariate analysis, predictors of hemorrhage were liver fatty change, gender, and body weight, but none of the mean CVP, surgeons, anesthesiologists, anesthesia duration, resected liver volume, hepatectomy type, systolic blood pressure, heart rate, or body temperature were significant. Conclusions: CVP during hepatic resection was not associated with intraoperative blood loss in living liver donors, suggesting that CVP may not be an important factor in predicting blood loss during hepatectomy in healthy subjects. [source]

Drying-induced birefringence of polyimide optical films

AICHE JOURNAL, Issue 3 2010
Po-Ju Chen
Abstract Drying-induced birefringence of polyimide film was investigated. The polyimide solutions were coated and dried on two different types of substrates and then removed for optical measurements. The operating window, which was a region for stable and uniform film formation, was determined experimentally. The out-of-plane birefringence (OPBR) was found to increase with decreasing dry film thickness, and the increase became more significant for films less than 10 ,m thick. The experimental OPBR results were compared with the predictions of two theoretical models. The results agreed reasonably well with the one-dimensional model of Lei et al. (J Appl Polym Sci. 2001;81:1000-1013). On the other hand, a simple viscoelastic model, which is an extension of the elastic model of Croll (J Appl Polym Sci. 1979;23:847-858), could provide clear physical insight, but its applicability was somewhat limited. The effects of several variables such as elasticity number, solidification concentration, yield stress, and mass transfer rate on OPBR were examined. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]

A CONTENT ANALYSIS OF RESEARCH IN FAMILY THERAPY JOURNALS

JOURNAL OF MARITAL AND FAMILY THERAPY, Issue 1 2000
Dale R. Hawley
In order to assess trends in family therapy research, empirical articles (N = 195) from three family therapy journals over a 5-year period were coded for several variables: authorship, external funding, methodology, sample, purpose, cost effectiveness, use of therapeutic model, and topic. Results indicated that a large pecentage of research in these journals focused on nonclinical issues and used nonclinical samples. Authors were affiliated with a wide variety of disciplines and reported low levels of external funding for their research. While a majority of the studies used quantitative methods, there appeared to be a growing number of studies using qualitative methods. Implications of these findings are discussed in light of research reviews over the past two decades. [source]

Marital Quality and Personal Well-Being: A Meta-Analysis

JOURNAL OF MARRIAGE AND FAMILY, Issue 3 2007
Christine M. Proulx
This study examines the association between marital quality and personal well-being using meta-analytic techniques. Effects from 93 studies were analyzed. The average weighted effect size r was .37 for cross-sectional and .25 for longitudinal effects. Results indicate that several variables moderate the association between marital quality and personal well-being, including gender, participants' marital duration, source of measurement, data collection year, and dependent variable. These results suggest that longitudinal effects are more likely to be uncovered when using standard measurement and that future research should use samples homogenous in marital length. The longitudinal finding that the strength of the association is stronger when personal well-being is treated as the dependent variable supports previous theorizing. [source]

Jet fires: An experimental study of the main geometrical features of the flame in subsonic and sonic regimes

AICHE JOURNAL, Issue 1 2009
A. Palacios
Abstract Although jet fires are usually smaller than other fires, they may lead to a destructive chain of events that can increase the scale of an accident. Therefore, their size should be predicted for accurate risk assessment. In the literature, most of the proposals for estimating jet fire size concern small jet fires (up to 2.5 m in length) or subsonic flames. In this study, experiments on relatively large propane jet fires in still air were performed. Vertical turbulent diffusion flames up to 10 m in length, with sonic and subsonic mass flow rates, were obtained using six different orifice exit diameters. The experiments were filmed with video and thermographic cameras and the resulting visible and infrared images were used to determine flame length and lift-off distance. Expressions for estimating jet length as a function of several variables (mass flow rate, orifice exit diameter, Froude and Reynolds numbers) are also proposed. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source]

Urinary Incontinence in Pregnancy and the Puerperium

JOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 6 2001
Charlotte E. Spellacy MS
Objective: To describe the incidence of urinary incontinence (UI) during pregnancy and the puerperium and to identify potential contributing factors. Design: A descriptive correlational design, using participant interviews and reviews of the existing medical records to determine the incidence of UI in pregnancy and the puerperium and to examine relationships between and among several variables. The variables included parity, episiotomy, use of forceps/vacuum extractor, type of anesthesia, prolonged Stage II labor, and race. Data were collected via two personal interviews and review of medical records. The first interview was conducted during the recruitment of each participant; the second was a telephone interview conducted 4 to 6 weeks postpartum. Data collected from the medical records included obstetric history, weeks of gestation, and estimated date of delivery. Data were entered into data files for analysis with SPSS 8.0 and summarized with descriptive statistics. Setting: A secluded area of a university teaching hospital prenatal clinic. Participants: A convenience sample of 50 pregnant women, at least 18 years old, who received their care at a large university hospital prenatal clinic in the southeastern part of the United States. Results: First Interview (N= 50). More than half (62%; n= 31) of the sample reported some degree of involuntary urine loss during their pregnancy. The racial distribution of those reporting UI was the following: white (70%; 21 out of 30); African American (44%; 8 out of 18); Hispanic/Asian (100%; n= 2). Among the participants who experienced UI (n= 31), 76% (n= 23) reported that their health care provider never asked if they were experiencing any UI symptoms. Second Interview (n= 24). Only 48% of the initial participants could be contacted for the second interview because of changes in residence or telephones being disconnected with no forwarding number. Of the women in this sample who reported UI during the first interview (59%; n= 14), 7 (50%) continued to experience UI 4 to 6 weeks postpartum. The 2 remaining participants who reported UI 4 to 6 weeks postpartum (22%) had not experienced UI during pregnancy. Of the participants experiencing postpartum UI, 77% (n= 7) were white. Almost half of the participants with postpartum UI were ages 35 or older (44%; n= 4). Among the participants reporting episiotomy (n= 4), 3 (75%) reported having UI 4 to 6 weeks postpartum. Conclusions: Study results support the conclusion that childbirth, specifically vaginal birth, is a major factor in developing UI in the early postpartum period. Age, race, and use of episiotomy appear to be contributing risk factors. [source]

Functionalized HMS mesoporous silica as solid phase extractant for Pb(II) prior to its determination by flame atomic absorption spectrometry

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2007
Damián Pérez-Quintanilla
Abstract In this work, a mesoporous silica has been chemically modified with 5-mercapto-1-methyl-1-H-tetrazol using the homogeneous route (MTTZ-HMS). This synthetic route involved the reaction of 5-mercapto-1-methyl-1-H-tetrazol with 3-chloropropyltriethoxysilane, prior to immobilization on the support. The resulting material has been characterized and employed as solid phase extractant for Pb(II). The effect of several variables (stirring time, pH, temperature, metal concentration, presence of other metals) has been studied using batch and column techniques. In batch experiments, 15 min stirring time, 55°C and pH 8 were the optimal conditions for Pb(II) adsorption. In column experiments, sorption was quantitative for 1000 mL of 2.41×10,4 mM of Pb(II) solution and adsorbed ions were eluted out by 5 mL of 1 M HCl (preconcentration factor of 200). Spiked tap water was used for the preconcentration and determination of Pb(II) by flame atomic absorption spectrometry, and a 100% recovery was obtained. The LOD and LOQ values of the proposed method were found to be 3.52×10,3 and 4.20×10,3 mM, respectively. The RSD for three preconcentration experiments was found to be ,2%. The linear working range for measurements was between 2×10,3 and 0.14 mM (y = 0.0136x + 0.0007, R2 = 0.9999). [source]

Ethnic patterns in the phonetics of Montreal English

JOURNAL OF SOCIOLINGUISTICS, Issue 4 2004
Charles Boberg
Most North American cities no longer display strong ethnic differentiation of speech within the European-origin population. This is not true in the English-speaking community of Montreal, Canada, where English is a minority language. Differences in the phonetic realization of vowels by Montrealers of Irish, Italian, and Jewish ethnic origin are investigated by means of acoustic analysis. A statistical analysis of ethnic differences in formant frequencies shows that ethnicity has a significant effect on several variables, particularly the phonetic position of /u:/ and /ou/ and the allophonic conditioning of /æ/ and /au/ before nasal consonants. The unusual tenacity of ethnophonetic variation in Montreal English is explained in light of the minority status of English, and the social and residential segregation of ethnic groups in distinct neighborhoods, which limits their exposure to speakers of Standard Canadian English who might otherwise serve as models for assimilation. [source]

Diagnostic score for heparin-induced thrombocytopenia after cardiopulmonary bypass

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2004
A. Lillo-Le Louet
Summary. Heparin-induced thrombocytopenia (HIT) occurs in nearly 3% of patients treated with heparin after cardiopulmonary bypass (CPB). HIT carries a risk of severe thrombotic complications, and must be diagnosed rapidly. To identify simple criteria for estimating the probability of HIT after CPB, we retrospectively analyzed the files of 84 patients with suspected HIT after CPB and we analyzed the usefulness of several variables collected at the time of HIT suspicion to estimate HIT probability. HIT was confirmed in 35 cases and ruled out in 49 cases, on the basis of a platelet increment after heparin withdrawal, detection of heparin-dependent antibodies, and absence of other clear cause of thrombocytopenia. A biphasic platelet count from CPB to the first day of suspected HIT, an interval of ,,5 days from CPB to the first day of suspected HIT, and a CPB duration of ,,118 min were independent risk factors for HIT. These variables were combined to create a post-CPB HIT probability score. The score correctly identified 34/35 HIT patients and 28/49-non-HIT patients. This score, which can be applied as soon as HIT is suspected after CPB, has very good negative predictive value (97%). Prospective studies are required to confirm these findings. [source]

A Capelli type theorem for multiplicative convolutions of polynomials

MATHEMATISCHE NACHRICHTEN, Issue 9 2008
Anca Iuliana Bonciocat
Abstract We prove a Capelli type theorem on the canonical decomposition for multiplicative convolutions of polynomials. We derive then some irreducibility criteria for convolutions of polynomials in several variables over a given field. The irreducibility conditions are expressed only in terms of the degrees of the polynomials in convolution, the degrees of their coefficients, and the degrees of some suitable divisors of the resulting leading coefficient. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Chitosan tailor-made films: the effects of additives on barrier and mechanical properties

PACKAGING TECHNOLOGY AND SCIENCE, Issue 3 2009
Cristiana M. P. Yoshida
Abstract With the aim of achieving ,tailor-made' chitosan films, the effects of several variables on the properties of chitosan films were studied. These variables were chitosan concentration and molecular weight of thermally depolymerized chitosan, addition of lipids (palmitic acid, beeswax or carnauba wax) and plasticizer (glycerol). The water vapour transmission rate (WVTR) and mechanical properties of these films were measured. The innovative feature of this study is that it provides specific information to support the design of tailor-made films. These can only be formulated when the effects of the important variables are well understood. It was found that WVTR was reduced by 57% in film made from chitosan that had been thermally treated for 7,h at 100°C (molecular mass 13.7,kDa), while in the emulsion films, the WVTR was increased by incorporation of palmitic acid, beeswax or carnauba wax incorporation. The mechanical properties (tensile strength and elongation at break) were improved when glycerol was used as plasticizer, resulting in more elastic films (increasing the elongation at break by 62%). Copyright © 2008 John Wiley & Sons, Ltd. [source]

Noninvasive assessment of energy expenditure in children

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2006
Isabelle Sarton-Miller
This study establishes an affordable, simple, and noninvasive method to assess energy expenditure (EE) in children, an underrepresented group. The method is based on regression modeling, where prediction of oxygen consumption (VO2), a proxy of EE, was deduced from heart rate (HR) and several variables that adjusted for interindividual variability. Limb activities (arms vs. legs) and posture (sitting vs. standing) were represented in the regression as dichotomous covariates. The order of activities and intensities was randomized. Seventy-four children (aged 7,10 years), raised at sea-level (Seattle, WA), comprised the sample. Anthropometric measures were taken, and VO2 and HR were measured for activities using the arms in sitting and standing positions (mixing and punching), as well as walking at different velocities on a treadmill. Repeated measures and least square regression estimation were used. HR, body mass, number of hours of physical activity per week (HPA), an interaction term between sitting and standing resting HR, and the two dichotomous variables, sex and limbs, were significant covariates; posture was not. Several equations were developed for various field uses. The equations were built from sea-level data, but ultimately this method could serve as a baseline for developing a similar approach in other populations, where noninvasive estimation of EE is imperative in order to gain a better understanding of children's energetic issues. Am. J. Hum. Biol. 18:600,609, 2006. © 2006 Wiley-Liss, Inc. [source]

Effects of modernisation on desired fertility in Egypt

POPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 5 2007
Angela Baschieri
Abstract Using a conceptual framework that borrows notions both from the economic theory of fertility and social interaction theory, this paper assesses the relative importance of social and economic modernisation at the individual and community level in explaining geographical differentials in desired fertility in Egypt. Using the 2000 Egyptian Demographic Health Survey and an up-to-date map of land cover in Egypt, this paper provides an application of an advanced methodology which uses a combination of multilevel modelling and geographical information system (GIS) techniques. The paper shows how GIS techniques facilitate the construction of several variables representing the level of economic modernisation, such as land use, road density and urbanisation. It illustrates how GIS techniques and multilevel modelling can help us to move forward a step in substantiating theories of community influences on fertility. This study also analyses the effect of current family composition on desired fertility in Egypt and reveals the desire of Egyptian society to have at least two children and at least one boy. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Further uses of the heat of oxidation in chemical hazard assessment

PROCESS SAFETY PROGRESS, Issue 1 2003
Laurence G. Britton
Flammability: The "net heat of oxidation" technique described in an earlier publication is extended to predicting the lower flammable limits, lower limit flame temperatures, and limiting oxygen concentrations of chlorinated organic fuels having H:Cl ratios greater than unity. A new Rule is derived for predicting the effect of initial temperature on the lower flammable limits and limiting oxygen concentrations of organic fuels. It is suggested that this Rule be used in preference to the modified "Burgess-Wheeler" Rule. The effect of initial pressure is discussed. Instability: Net heats of oxidation (kcal/mol oxygen) for a series of disparate fuel groups are compared with ",HD," the maximum heat of decomposition (cal/g) calculated using CHETAH methodology. Given the reasonable assumption that CHETAH's "maximum heat of decomposition" cannot exceed the net heat of combustion ",HC," examination is made as to whether the ratio of these parameters (each expressed in units of kcal/mol), coined the "Reaction Heat Ratio" (RH), provides a useful new indicator for instability assessment. Of these parameters, the net heat of oxidation (,HC/S) is the best indicator to help assign NFPA Instability Ratings. However, ,HC/S cannot generally be used to assign ratings for organo-peroxides. Also, its performance as an indicator for hazardous polymerization depends on the ,HC/S difference between the reacting monomer and the polymer product, so it should become increasingly unreliable as the monomer ,HC/S approaches -100 kcal/mol oxygen. The ranking method tacitly assumes organic polymers to have a constant heat of oxidation of about -100 kcal/mol oxygen. Errors in this assumption must invalidate the ranking approach where ,HC/S differences are small. Finally, separate "cut-offs" must be used at each NFPA Instability Rating for organo-nitrates versus other organics containing combinations of CHON atoms. Additional materials need to be examined to extend this preliminary analysis. The net heat of oxidation would be a useful additional output parameter of the CHETAH program, if only for its application in flammability assessment. No conclusions are drawn regarding the usefulness of net heat of oxidation or RH in conducting CHETAH hazard assessments, since this procedure requires consideration of several variables. However, the analysis may be helpful to the ASTM E 27.07 subcommittee responsible for developing the program. For example, the -,HD , 700 cal/g cut-off used to assign a "high" CHETAH hazard rating typically corresponds to organic materials rated NFPA 1, the second to lowest hazard rating. [source]