Multiple regression Model Research Papers (original) (raw)

Much remains to be clarified in the apparently protective effect of moderate alcohol use against coronary heart disease risk. Insulin levels are positively associated with coronary heart disease risk, so recent reports of decreased insulin sensitivity among nondrinkers and lower fasting insulin levels with increasing alcohol intake suggest the possibility that insulin may play a role. Between 1987 and 1991, the authors examined fasting insulin concentrations and the empiric fasting insulin resistance index in relation to reported alcohol intake (mean, 15.3 g/day; standard deviation, 19.6; range, 0-120.6) and potential confounders. The latter included age, obesity, fat distribution, smoking, energy, saturated fat intake, antihypertensive medication, and physical activity. Participants in this cross-sectional analysis were 938 nondiabetic men from the Boston, Massachusetts, area who were part of the Normative Aging Study. Unadjusted fasting insulin levels were significantly different (p = 0.008) between categories of alcohol intake, as were fasting insulin resistance index values (p = 0.01). After adjustment for potential confounders, analysis revealed that subjects consuming moderate amounts of alcohol had the lowest fasting insulin and fasting insulin resistance index values. Compared with values from moderate drinkers, fasting insulin resistance index values were higher in those subjects reporting no alcohol intake (p = 0.011), low intake (p = 0.004), and high intake (p = 0.04). A similar pattern was observed for fasting insulin values. Among this sample of nondiabetic men, moderate drinkers had the lowest levels of fasting insulin resistance index and fasting insulin, consistent with lower levels of insulin resistance and thus lower risk for cdronary heart disease. These findings suggest the possibility that the coronary heart disease-protective effects of moderate alcohol use are at least partially mediated by insulin. Am J Epidemiol 1997;145:909-16. alcohol drinking; coronary disease; insulin; risk factors Much remains to be clarified with regard to the protective effect of moderate habitual alcohol use against coronary heart disease risk (1). One plausible partial explanation (2) is that the lower coronary heart disease rates observed in subjects with low to moderate levels of alcohol intake are mediated by increased levels of high density lipoprotein cholesterol (3-5).

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- Metabolism, Skeletal muscle biology, Aging, Physical Activity

To investigate the incidence, efficacy, and safety of elective induction in a community teaching hospital over 1 year. Methods: This is a retrospective case-control study of rate, safety, and efficacy of all term inductions with vertex presentations judged to be elective by chart analysis. Cases were matched one for one for age, parity, and pay status with controls in spontaneous labor. The elective induction women were compared with those in spontaneous labor using 2 Student t test, and Fisher exact test. Potential risk factors for cesarean delivery and neonatal intensive care unit (NICU) admission were then selected and subjected to bivariate analysis. Stepwise logistic regression was applied to control for confounding and to select which risk factors were important for those end points. Results: There were 461 case-control pairs. The elective induction rate was 12.3%. Cesarean delivery was increased by elective induction in bivariate analysis (odds ratio [OR] ‫؍‬ ‫؍‬ ‫؍‬ 1.81, confidence interval [CI] ‫؍‬ ‫؍‬ ‫؍‬ 1.07, 3.08; power ‫؍‬ ‫؍‬ ‫؍‬ .60). The cesarean delivery rate was 8.7% (control 5.0%). In a multiple regression model of potential risk factors for cesarean delivery, nulliparity (

- by Frank Castronova
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- Comparative Study, Logistic Regression, Birth Weight, Oxytocin

We present a multiple regression model that explores post-return adjustment of school-age children who experienced abduction by a parent. The model includes: a) child and family characteristics preceding abduction, b) characteristics of the abduction experience, and c) child and family characteristics following return. Overall, the model accounts for 21% of the variance in post-return adjustment of children (p < .05). The most salient finding is that post-return adjustment of children was best explained by characteristics of the chiM and family before the abduction occurred. Domestic violence perpetrated by one or both parents was the most significant factor.

- by Rebecca Hegar
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- Psychology, Domestic Violence, Linguistics, Child Abuse

Background/Objectives: To assess biomarkers and frequency questions as measures of fish consumption. Subjects/Methods: Participants in the Fishermen substudy numbered 125 men and 139 women (aged 22-74), and in the Health 2000 substudy, 577 men and 712 women (aged 45-74) participated. The aim of the Fishermen study was to examine the overall health effect of fish consumption in a high-consumption population, whereas the aim of the Health 2000 substudy was to obtain in-depth information on cardiovascular diseases and diabetes. Fish consumption was measured by the same validated food frequency questionnaire (FFQ) in both the studies, with a further two separate frequency questions used in the Fishermen substudy. Dioxins, polychlorinated biphenyls (PCBs) and methyl mercury (MeHg) (in the Fishermen substudy alone), and omega-3 polyunsaturated fatty acids (omega-3 PUFAs) (in both studies) were analyzed from fasting serum/blood samples. Results: The Spearman's correlation coefficients between FFQ fish consumption and dioxins, PCBs, MeHg and omega-3 PUFAs were respectively 0.46, 0.48, 0.43 and 0.38 among the Fishermen substudy men, and 0.28, 0.36, 0.45 and 0.31 among women. Similar correlation coefficients were observed between FFQ fish consumption and serum omega-3 PUFAs in the Health 2000 substudy, and also between FFQ fish consumption and the frequency questions on fish consumption in the Fishermen substudy. According to multiple regression modeling and LMG metrics, the most important fish consumption biomarkers were dioxins and PCBs among the men and MeHg among the women. Conclusions: Environmental contaminants seemed to be slightly better fish consumption biomarkers than omega-3 PUFAs in the Baltic Sea area. The separate frequency questions measured fish consumption equally well when compared with the FFQ.

- by Hannu Kiviranta
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- Nutrition and Dietetics, Nutrition, Nonparametric Statistics, Metabolism
- by Alejandro Blei
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- Geography, Public Transport, Urban And Regional Planning, Urbanisation

Aim To describe the geographical pattern of mean body size of the non-volant mammals of the Nearctic and Neotropics and evaluate the influence of five environmental variables that are likely to affect body size gradients. Location The Western Hemisphere. Methods We calculated mean body size (average log mass) values in 110 × 110 km cells covering the continental Nearctic and Neotropics. We also generated cell averages for mean annual temperature, range in elevation, their interaction, actual evapotranspiration, and the global vegetation index and its coefficient of variation. Associations between mean body size and environmental variables were tested with simple correlations and ordinary least squares multiple regression, complemented with spatial autocorrelation analyses and split-line regression. We evaluated the relative support for each multiple-regression model using AIC. Results Mean body size increases to the north in the Nearctic and is negatively correlated with temperature. In contrast, across the Neotropics mammals are largest in the tropical and subtropical lowlands and smaller in the Andes, generating a positive correlation with temperature. Finally, body size and temperature are nonlinearly related in both regions, and split-line linear regression found temperature thresholds marking clear shifts in these relationships (Nearctic 10.9 ° C; Neotropics 12.6 ° C). The increase in body sizes with decreasing temperature is strongest in the northern Nearctic, whereas a decrease in body size in mountains dominates the body size gradients in the warmer parts of both regions. Main conclusions We confirm previous work finding strong broad-scale Bergmann trends in cold macroclimates but not in warmer areas. For the latter regions (i.e. the southern Nearctic and the Neotropics), our analyses also suggest that both local and broad-scale patterns of mammal body size variation are influenced in part by the strong mesoscale climatic gradients existing in mountainous areas. A likely explanation is that reduced habitat sizes in mountains limit the presence of larger-sized mammals.

- by Miguel A Rodriguez
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- Geography, Macroecology, Biology, Ecology
- by Mojtaba Ahmadi
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- Engineering, Response Surface Methodology, Wastewater Treatment, Water Pollution

El objetivo de este trabajo es analizar la contribución que tiene una serie de determinantes en el comportamiento de queja con el fin de identificar la combinación que mejor explica las respuestas de queja, a terceras partes y privadas. Utilizando el contexto de los restaurantes y la metodología basada en modelos de regresión múltiple (método secuencial de estimación paso a paso), los resultados más relevantes indican que la probabilidad de éxito de la queja es la variable que mayor influencia tiene sobre las respuestas de queja, mientras que es el nivel de insatisfacción en el caso de las respuestas privadas. PALABRAS CLAVE: Insatisfacción, Comportamiento de queja, Respuestas de queja, Respuestas privadas.

- by MARIA FUENTES-BLASCO
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- Dissatisfaction, Palabras Clave: BIM, Multiple regression Model

We investigated the vertical distribution of seeds in the soil, using data from nine studies in five European countries. We discovered significant correlations between seed shape and distribution in the soil. 2. The classification of the longevity of seeds of plant species has been improved by the introduction of a 'longevity index', expressing on a continuous scale the most recent information on seed longevity represented as the proportion of non-transient seed bank records in the database of . Remarkably, no difference in seed longevity was found if the index was based on direct observations only when compared with the index based on the complete data set where indirect, 'depthderived' observations were included. 3. Seed longevity was best estimated using a multiple regression model with an integrated measure of seed size and shape and depth distribution of seeds. 4. The shape of seeds, known to be a consistent character of species, was shown to be constant within species, whereas depth distribution of seeds was highly variable among sites. This is consistent with the variability of seed longevity found in published seed bank data.

- by Peter Poschlod
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- Functional Ecology, Seed longevity, Biological Sciences, Environmental Sciences

In this presentation a methodology is suggested for site assessment and site selection based in a data analysis framework. This framework consists in tree steeps using different data analysis methods from cluster analysis, classification trees and regression analysis. The different variables selected in all the models used for the three steeps are compared and the spatial analysis data importance in site assessment is evaluated. For variable importance several measures can be used. In this text we use the discriminant power for the selection of profiling variables and a precision index for classification trees. Dominance analysis is used for the multiple regression models in the forecasting procedure. The advantage of this technique over other techniques as the standardized coefficients is that it overcomes some limitations of stepwise regression. The different measures of variable importance result in a clear pattern for the relevance of spatial analysis variables, being only dominated by the "trade area". So, spatial analysis resulting variables are of special importance in site assessment studies and the delimitation method used for their calculation is relevant in their usefulness.

- by Armando Mendes
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- Spatial Analysis, Data Analysis, Spatial Data Analysis, Discriminant Analysis

This study investigates determinants of sustainable food consumer behaviour in Belgium. To gain a better insight in sustainable consumption, a study was conducted in which attitudes and behaviour as well as the role of individual characteristics like confidence and values related to sustainable products are analyzed. The focus of the analysis is on exploring the influence of determinants as hypothesised by the theory of planned behaviour (TPB)attitudes, perceived behavioural control, social normson sustainable consumption intention in general, and specifically depending on consumer's perceived confidence and personal values. The empirical research builds on a survey with a sample of 456 young adults using a questionnaire and showing an advertisement for hypothetical sustainable dairy products. Stepwise multiple regression models showed that 50% of the variance in intention to consume sustainable dairy was explained by the combination of personal attitudes, perceived social influences, perceived consumer effectiveness and perceived availability. In addition, different levels of confidence and value orientation yield different strengths of the determinants. The findings yield public policy and marketing recommendations for stimulating sustainable food consumption among young adults.

- by iris vermeir
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- Theory of Planned Behaviour, Values, Ecological Economics, Sustainable Development

Diatoms from the genus Achnanthidium are abundant in rivers, streams, and springs of the Appalachian Mountains. They inhabit clean and polluted waters, including those affected by acid mine drainage. The identification of Achnanthidium taxa is difficult due to their small cell size and insufficient information in the diatom floras. We studied the taxonomy and ecology of Achnanthidium in Appalachian rivers by analyzing a data set of benthic diatom samples and corresponding water chemistry data collected during several water-quality surveys from 181 sampling sites. Ten species were identified using scanning electron and light microscopy: A. alpestre (Lowe & Kociolek) Lowe & Kociolek, A. atomus (Hustedt) Monnier, Lange-Bertalot, & Ector, A. deflexum (Reimer) Kingston, A. duthii (Sreenivasa) Edlund, A. eutrophilum (Lange-Bertalot) Lange-Bertalot, A. cf. gracillimum (Meister) Lange-Bertalot, A. cf. latecephalum Kobayasi, A. minutissimum (Ku¨tzing) Czarnecki (sensu lato), A. reimeri (Camburn) comb. nov., and A. rivulare Potapova & Ponader.

- by Marina Potapova
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- Water quality, Taxonomy, Acid Mine Drainage, Ecology

Purpose -Using a stakeholder perspective, this paper aims to investigate the effectiveness of sponsorship as a business investment by assessing the impact of sponsorship announcements on the shareholders' reactions of the sponsoring firms. These reactions are examined in two different occasions: in an international mega sport event such as the Olympic Games and in sport organizations such as sport federations/associations. Design/methodology/approach -Event study analysis by using multiple regression models and bootstrapping techniques were employed to study the effects of sponsorship announcements. The sample consisted of sponsors of the 2004 Olympic Games and sponsors of national sport federations. Findings -Overall, the results of the study did not indicate any significant effects of sponsorship announcements on the stock prices of sponsoring firms, suggesting that shareholders' reactions to this business activity are limited. Originality/value -This is the first research initiative that utilizes a stakeholder approach in examining sponsorship effectiveness. The findings provide evidence that shareholders do not perceive sport sponsorships as business investments due to limited information provided by the sponsoring firms. In addition to theoretical and practical implications, the study proposes a new methodological approach in evaluating the impact of sport sponsorship. Multiple regression models applying bootstrap techniques to avoid data distribution and small sample problems are recommended.

- by Rodoula Tsiotsou
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- Marketing, Olympic Games, Stakeholder Theory, Business and Management

Turmeric is native to India and its successful husbandry depends on the monsoon climate and the availability of irrigation. Yield forecasting in advance is required for export planning and policy decisions. A method to forecast turmeric yield from a time series of meteorological and yield data was developed and tested, using 20-year dataset of dry turmeric yield and monthly climatic variables for the crop's 9-month growing season. The variables, which had a significant correlation with yield were second month total rainfall (r = 0.60), third month mean evaporation (r = −0.49), fourth month mean wind speed (r = 0.61), fifth, eighth and ninth month mean minimum temperature (r = 0.45, 0.51 and 0.65, respectively) and ninth month mean minimum relative humidity (r = 0.66).

- by K. Kandiannan
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- Earth Sciences, Time Series, Climate variability, Tamil Nadu
- by Manuel Madeira
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- Environmental Science, Data Mining, Prediction, Agroforestry

The study examines the impact of religion on women empowerment. Three religions, indigenous African, Islam and Christianity, comprising Africa's triple heritage, are considered. The hypothesized relationships are confirmed. Christianity correlates with each of the four Development Targets specified for women empowerment under the third of the Millennium Development Goals (MDGs), including raising the: (1) percentage of school-aged girls in school, (2) female adult literacy rates, (3) female share of non-agricultural employment, and (4) female representation in government. African indigenous religion correlates with Target #3. Islam is inversely linked to each of the four Targets. A composite index incorporating values on these Targets was developed and employed as the dependent variable in a multiple regression model. The model is statistically significant, and confirms the hypothesis of a link between women empowerment and religion. Therefore, any meaningful effort to promote women empowerment in Africa must account for the continent's three main religions.

- by Ambe J Njoh and +1
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- Sociology, Social Indicators, Statistical Significance, Indexation
- by Mahdi Salehi
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- Business Intelligence, Financial Distress, Emerging Market, Profitability

River flow forecasting Artificial neural network Adaptive neuro fuzzy inference system Support vector machine s u m m a r y Data driven models are very useful for river flow forecasting when the underlying physical relationships are not fully understand, but it is not clear whether these data driven models still have a good performance in the small river basin of semiarid mountain regions where have complicated topography. In this study, the potential of three different data driven methods, artificial neural network (ANN), adaptive neuro fuzzy inference system (ANFIS) and support vector machine (SVM) were used for forecasting river flow in the semiarid mountain region, northwestern China. The models analyzed different combinations of antecedent river flow values and the appropriate input vector has been selected based on the analysis of residuals. The performance of the ANN, ANFIS and SVM models in training and validation sets are compared with the observed data. The model which consists of three antecedent values of flow has been selected as the best fit model for river flow forecasting. To get more accurate evaluation of the results of ANN, ANFIS and SVM models, the four quantitative standard statistical performance evaluation measures, the coefficient of correlation (R), root mean squared error (RMSE), Nash-Sutcliffe efficiency coefficient (NS) and mean absolute relative error (MARE), were employed to evaluate the performances of various models developed. The results indicate that the performance obtained by ANN, ANFIS and SVM in terms of different evaluation criteria during the training and validation period does not vary substantially; the performance of the ANN, ANFIS and SVM models in river flow forecasting was satisfactory. A detailed comparison of the overall performance indicated that the SVM model performed better than ANN and ANFIS in river flow forecasting for the validation data sets. The results also suggest that ANN, ANFIS and SVM method can be successfully applied to establish river flow with complicated topography forecasting models in the semiarid mountain regions.

- by Mark Last
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- Marketing, Engineering, Cognitive Science, Econometrics

Objetivo: Reconocer la relación entre el tipo de lactancia materna y el riesgo de asma bronquial. Métodos: Estudio de casos y controles. Los casos (asmáticos, n= 31) y controles (no asmáticos, n=79) se seleccionaron de una muestra no probabilística de tipo accidental. El análisis se realizó por regresión múltiple. Ambiente: Dos comunidades de los Estados Lara y Yaracuy, entre 1998 y 1999. resultados: La lactancia materna complementaria, así como la suplementaria se asociaron a mayor riesgo de presentar el diagnóstico de asma bronquial (razones de posibilidades iguales a 4,5 y 17,8, respectivamente). Conclusiones: La lactancia materna exclusiva parece asociarse a protección contra el asma bronquial, por lo que debe ser promovida en las comunidades.

The influence of pore structure, water transport properties and rock strength on salt weathering is evaluated by means of a thorough rock characterisation and a statistical analysis. The pore structure was described in terms of its porosity, pore size distribution (quantified by mean pore radius) and specific surface area, density and water transport was characterised by means of water permeability (saturated flow) and capillary imbibition (unsaturated flow); whilst the rock strength test was carried out using uniaxial compressive strength, compressional and shear wave velocities, dynamic elastic constants and waveform energy and attenuation were obtained from the digital analysis of the transmitted signal. A principal component analysis and a stepwise multiple regression model was carried out in order to examine the direct relationships between salt weathering and petrophysical properties. From the principal component analysis, two main components were obtained and assigned a petrophysical meaning. The first component is mostly linked to mechanical properties, porosity and density whereas the second component is associated with the water transport and pore structure. Salt weathering, quantified by the percentage of weight loss after salt crystallisation, was included in both principal components, showing its dependence on their petrophysical properties. The stepwise multiple regression analysis found that rock strength has a predominant statistical weight in the prediction of salt weathering, with a minor contribution of water transport and pore structure parameters.

In collaboration with the Business Intelligence Service of London, UK and with the European Business School of Cambridge, UK, the Business Intelligence Journal (BIJ), produced by the Department of Business Management and Economics (BME) at the School of Doctoral Studies of the European Union, hosted at the Isles Internationale Université (IIU-EU) in Brussels, Belgium, publishes research, analysis and inquiries into issues of importance to the business community. Articles in BIJ examine emerging trends and concerns in the areas of general management, business law, public responsibility and ethics, marketing theory and applications, business finance and investment, general business research, business and economics education, production/operations management, organizational behavior and theory, strategic management policy, social issues and public policy, management organization, statistics and econometrics, personnel and industrial relations, technology and innovation, case studies, and management information systems. The goal of BIJ is to broaden the knowledge of business professionals and academicians by promoting free access and provide valuable insight to business-related information, research and ideas. All articles included in the BIJ are peer-reviewed. The Business Intelligence Journal is published semiannually (one volume per year) by the Business Intelligence Service of Secured Assets Yield Corporation Limited based in London, UK.

- by Behzad Abedini
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- Business, Business Intelligence, Financial Distress, Emerging Market

In the present study, prediction of agricultural drought has been addressed through prediction of agricultural yield using a model based on NDVI-SPI. It has been observed that the meteorological drought index SPI with different timescale is correlated with NDVI at different lag. Also NDVI of current fortnight is correlated with NDVI of previous lags. Based on the correlation coefficients, the Multiple Regression Model was developed to predict NDVI. The NDVI of current fortnight was found highly correlated with SPI of previous fortnight in semi-arid and transitional zones. The correlation between NDVI and crop yield was observed highest in first fortnight of August. The RMSE of predicted yield in drought year was found to be about 17.07 kg/ha which was about 6.02 per cent of average yield. In normal year, it was 24 kg/Ha denoting about 2.1 per cent of average yield.

- by Arnab Kundu
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- Geomatic Engineering, Mantle Transition Zone, Correlation coefficient, Indexation

This article develops a rapid response ridership forecast model, based on the combined use of Geographic Information Systems (GIS), distance-decay functions and multiple regression models. The number of passengers boarding at each station in the Madrid Metro network is estimated as a function of the characteristics of the stations (type, number of lines, accessibility within the network, etc.) and of the areas they serve (population and employment characteristics, land-use mix, street density, presence of feeder modes, etc.). The paper considers the need to evaluate the distance threshold used (not the choice of a fixed distance threshold by assimilation from other studies), the distance calculation procedure (network distance versus straight-line distance) and, above all, the use of distance-decay weighted regression (so that the data from the bands nearer the stations have a greater weighting in the model than those farther away). Analyses carried out show that weighting the variables according to the distance-decay functions provides systematically better results. The choice of distance threshold also significantly improves outcomes. When an all-or-nothing function is used, the way the service area is calculated (straight-line or network distances) does not seem to have a decisive influence on the results. However, it seems to be more influential when distance-decay weighting is used.

Objective-To evaluate the performance of nondemented subjects 85 years and older on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery, and to assess its relationship with sociodemographic... more

- by Michal Beeri
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- Cognitive Science, Neurology, Higher Education, Aging

First theories proposed to explain determinants of postmarital residence connected it with the division of labor by gender. However, at the moment all the cross-cultural tests of this hypothesis using worldwide samples have failed to find any significant relationship between these two variables. Our tests have shown that the female contribution to subsistence does correlate significantly with matrilocal residence in general; however, this correlation is hidden by general polygyny factor. Though the rise of female contribution to subsistence tends to lead to matrilocal residence, it also tends simultaneously to lead to general non-sororal polygyny, which effectively destroys matrilocality. This factor being controlled (e.g. through a multiple regression model) labor division turns out to be a significant predictor of postmarital residence. Thus, this paper shows that Murdock's hypotheses regarding the relationships between the labor division and postmarital residence were basically correct, though the actual relationships between those two groups of variables turn out to be more complicated than he expected.

- by Andrey Korotayev
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- Division of labor, World Cultures, Multiple regression Model

An existing dataset of area-specific sediment yield (SSY) for 60 catchments in Spain that was retrieved from sediment deposition rates in reservoirs . Sediment yield at Spanish reservoirs and its relationship with the drainage basin area. ] reveals that catchment area alone explains only 17% of the variability in SSY. In this study, an attempt to explain the remaining variability in SSY was made using a quantitative and a semiqualitative approach for 22 catchments. During a field survey, the 22 selected catchments were characterised by topography, vegetation cover, lithology, shape and the presence of gullies in the broad vicinity of the reservoir. This information was used to develop a factorial scoring index model that provides a fairly accurate and reliable prediction of SSY. A classical multiple regression model using climatic, topographic and land use properties derived from regional datasets could not explain as much variance as the qualitative index model, nor did it appear to be as reliable. The same conclusion could be drawn when using the CORINE soil erosion risk map of southern Europe. The low prediction capability of the multiple regression models and the CORINE soil erosion risk map could be attributed mainly to the fact that these methods do not incorporate gully erosion and that the land cover data are not a good representation of soil cover. Both variables have been shown to be of great importance during the field surveys. Future assessments of SSY could be quickly and efficiently made using the proposed factorial scoring index model. In comparison with other models, which demand more data, the index model offers an alternative prediction tool. D

- by Gert Verstraeten
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- Geology, Geomorphology, Statistical Analysis, Prediction

Open access (OA) to the research literature has the potential to accelerate recognition and dissemination of research findings, but its actual effects are controversial. This was a longitudinal bibliometric analysis of a cohort of OA and... more

- by 4 4
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- Information Systems, Publishing, Open Access, Bibliometrics

- by Miguel Rodríguez
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- Geography, Macroecology, Ecology, Climate
- by Hung-Yi Chuang
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- Nutrition, Neurotoxicology, Lactose intolerance, Peripheral Nervous System
- by ali Hobani
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- Statistical Analysis, Enthalpy, Temperature, Phase Change

We examined relationships between Dutch butter¯y species and the Ellenberg indicator values for nutrients, acidity and moisture. Presence/absence data on butter¯ies were obtained from monitoring transects of the Dutch Butter¯y Monitoring Scheme. Mean indicator values were calculated from vegetation samples of a selection of transect sections. Single and multiple logistic regression models were used to analyse the relationships. Except for the moisture value, the vegetation samples covered the Ellenberg scales quite well. Signi®cant correlations between moisture and acidity (À) and nutrients and acidity (+) were observed. Sites that were both acid and nutrient-rich were not observed. Most of the observed signi®cant relationships were unimodal (Gaussian), in which species show a clear optimum indicator value. Other species showed a sigmoidal (linear) response to one or more of the ecological indicator values. Several species were signi®cantly correlated with all three indicator values. For a small group this was also the case in the multiple regression model. This was probably caused by multicollinearity of the indicator values, leading to some spurious signi®cant single regression models. We discuss methodical problems and possibilities for re®nements of the models. The observed relationships between butter¯ies and indicator values agreed well with available ecological information.The observed regression models can be used to (a) predict the eects of environmental factors on the butter¯y fauna, (b) use changes in the abundances of certain species as indicators of ecological processes and (c) determine the sensitivity of butter¯ies for eutrophication, acidi®cation and groundwater draining. In conclusion, the models provide a powerful aid in the conservation of butter¯ies in a changing environment.

The aim of the present paper was to improve and expand research with a larger number of children from various European countries and to provide a common formula useful for all these countries. Orthopantomographs taken from 2,652 European Caucasian children (1,382 boys, 1,270 girls) aged between 4 and 16 years were analyzed. The children came from Croatia, Germany, Kosovo, Italy, Slovenia, Spain, and the UK. Following the pilot study, subjects’ age was modeled as a function of gender (g), morphological variables (predictors) × 5(second premolar), s (sum of normalized open apices) N 0, and the first-order interaction between s and N 0. The results showed that all these variables contributed significantly to the fit, so that all were included in the regression model, yielding the following linear regression formula: Age = 8.387 + 0.282 g − 1.692 × 5 + 0.835 N 0 − 0.116 s − 0.139 s × N 0, where g is a variable, 1 for males and 0 for females. The equation explained 86.1% (R 2 = 0.861) of total deviance. The median of the residuals (=observed age minus predicted age) was −0.114 years, with (RefB.2) interquartile range = 1.22 years.

- by Mariano Cingolani
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- Statistical Analysis, Adolescent, Linear models, India
- by ANDREW REYNOLDS
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- Plant Biology, Modeling, Treatment, Wine

The main purpose of the study is to develop a general prediction model and to investigate the relationships between sound level produced during drilling and physical properties such as uniaxial compressive strength, tensile strength and percentage porosity of sedimentary rocks. The results were evaluated using the multiple regression analysis taking into account the interaction effects of various predictor variables. Predictor variables selected for the multiple regression model are drill bit diameter, drill bit speed, penetration rate and equivalent sound level produced during rotary drilling (L eq). The constructed models were checked using various prediction performance indices. Consequently, it is possible to say that the constructed models can be used for practical purposes.

- by Harsha Vardhan
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- Civil Engineering, Rock Mechanics, Variable Selection, Compressive Strength

The main idea of this paper is to identify functional relations between seakeeping characteristics and hull form parameters of Mediterranean fishing vessels. Multiple regression analysis is used for quantitative assessment through a computer software that is based on the SQL Server Database. The seakeeping attributes under investigation are the transfer functions of heave and pitch motions and of absolute vertical acceleration at stern, while the ship parameters influencing motion dynamics have been classified into two groups: displacement (D) and main dimensions (L, B, T), coefficients that define the details of the hull form (C WP , C VP , LCB, LCF, etc.).

- by Ali Başak
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- Civil Engineering, Ocean Engineering, Design, Data Analysis

Due to wide application of evapotranspiration (ET) data, a number of indirect methods for estimation of reference ET (ETo) have been developed. Therefore, it becomes impractical for many users to select the best ETo estimation method for the available data and climatic condition. To overcome this problem, a decision support system (DSS ET) was developed which supports 22 ETo estimation methods with varied options for calculation of various intermediate parameters, generalized data input format with copy-paste option from spreadsheet applications, visualize/check input data and results, features to estimate missing data, and user-friendly graphical user interface (GUI) that enhances its applicability as a handy research and teaching tool. Monthly meteorological data for 32 years (1971-2002) were procured from IMD, Pune, for 133 selected stations evenly distributed over five climatic ecosystems of India. Altogether 18 ETo estimation methods, including the globally accepted standard method FAO-56 Penman-Monteith (PM), were found applicable for the data availability conditions used in this study. In absence of lysimeter measured ETo data, the FAO-56 PM ETo values were used to estimate the normal monthly ETo for each station and climatic condition. Finally, ranks were assigned to each applicable ETo method based on weighted standard error of estimate (WSEE) with respect to the FAO-56 PM method for different climatic ecosystems. If, because of poor data availability condition, it becomes unavoidable to use methods other than FAO-56 PM, then these ranks can readily be used to select the best applicable method in the existing data and climatic conditions to get ETo values closer to FAO-56 PM estimates.

- by Sergio Hernandez
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- Earth Sciences, Computer Science, Climate variability, Evaporation

Initial symptom severity is a client characteristic associated with psychotherapy outcome, although this relationship is not well-understood. Readiness to change is a factor that may influence this relationship. This study tested readiness as a moderator of the relationship between initial severity and symptom change. Data were derived from an RCT examining the efficacy of a transdiagnostic CBT treatment. Readiness was assessed with the URICA, and symptom and functioning outcomes were assessed. Multiple regression models indicated that severity was associated with less overall change, yet readiness moderated this relationship. At higher levels of readiness, the effect of initial severity on outcome was essentially reversed; for clients with higher initial readiness, higher levels of severity were associated with greater change.

- by Nicole Solange Plaza Delgado
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- Psychology, Social Work, Anxiety Disorders, Psychotherapy

This research applies neural network (NN) technology to real estate appraisal and compares the performance of two NN models in estimating the sales price of residential properties with a traditional multiple regression model. The study is based on 288 sales of homes in Fort Collins, Colorado. Results do not support previous findings that NNs are a superior tool for appraisal analysis. Furthermore, significant problems were encountered with the NN models: inconsistent results between packages, inconsistent results between runs of the same package and long run times. Any appraiser who plans on using this new technology should do so with caution.

- by Ana Silva
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- Real Estate, Neural Network, New Technology, Multiple Regression

Purpose – To show how the analytical and visualization capabilities of geographic information systems (GIS) can enhance the communication, understanding and utility of data and information to be used in marketing planning, as compared with their conventional presentation as text and tables. Design/methodology/approach – A digital map of the study area was generated and a set of market zones. A multiple regression model for predicting sale of the product under study was then developed, taking into account sales figures from specific distribution outlets and the demographic and socio-economic characteristics of the population served by the distribution outlets in the identified market zones. Optimum routes and times between the manufacturing plant and the distribution outlets were derived. Findings – Combining geospatial methods with conventional marketing techniques enables users to visualize the spatial distribution of data in maps, complemented by various statistical graphs and dia...

- by David Siriba
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- Marketing, Market Segmentation, Distributed Processing, Case Study

Labour-intensive mines are numerous in several developing countries, but dust exposure in such mines has not been adequately characterized. The aim of this study was to identify and quantify the determinants of respirable dust and quartz exposure among underground coal mine workers in Tanzania. Personal respirable dust samples (n = 134) were collected from 90 underground workers in June-August 2003 and July-August 2004. The development team had higher exposure to respirable dust and quartz (geometric means 1.80 and 0.073 mg m À3 , respectively) than the mining team (0.47 and 0.013 mg m À3 ), the underground transport team (0.14 and 0.006 mg m À3 ) and the underground maintenance team (0.58 and 0.016 mg m À3 ). The percentages of samples above the threshold limit values (TLVs) of 0.9 mg m À3 for respirable bituminous coal dust and 0.05 mg m À3 for respirable quartz, respectively, were higher in the development team (55 and 47%) than in the mining team (20 and 9%). No sample for the underground transport team exceeded the TLV. Drilling in the development was the work task associated with the highest exposure to respirable dust and quartz (17.37 and 0.611 mg m À3 , respectively). Exposure models were constructed using multiple regression model analysis, with log-transformed data on either respirable dust or quartz as the dependent variable and tasks performed as the independent variables. The models for the development section showed that blasting and pneumatic drilling times were major determinants of respirable dust and quartz, explaining 45.2 and 40.7% of the variance, respectively. In the mining team, only blasting significantly determined respirable dust. Immediate actions for improvements are suggested to include implementing effective dust control together with improved training and education programmes for the workers. Dust and quartz in this underground mine should be controlled by giving priority to workers performing drilling and blasting in the development sections of the mine.

- by Yohana S
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- Occupational Health, Environmental Monitoring, Tanzania, Linear models
- by ANDREW REYNOLDS
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- Plant Biology, Modeling, Treatment, Wine

Particulate matters (PM) constitute a major concern for air quality of metropolitan cities. In this paper, the problem of air quality forecasting of respirable suspended particulate matter (RSPM) based on some meteorological factors has been discussed. The present work deals with the application of three statistical models to forecast daily averaged concentration of RSPM in urban Delhi and Hong Kong. Model 1 is based on multiple linear regression of meteorological parameters, model 2 is based on Box-Jenkins time series auto regressive integrated moving average (ARIMA) model and model 3 is a combination of the two. A detailed analysis of results of above models shows that the combination of ARIMA and multiple regression (model 3) gives better results in comparison to the other two models with respect to observed data. Thus the model 3 has been used, in the present study, to forecast the air quality of Delhi and Hong Kong with respect to RSPM. It has been concluded that the same model may be used as a practical prognostic model for prediction of RSPM in urban cities. r

- by Pramila Goyal and +1
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- Environmental Engineering, Air Quality, Time Series, Atmospheric sciences

An empirical model based on an ecohydrological approach was developed, which allows the integration of hydrographical, topographical and physicochemical information with vegetation characteristics of mangroves and marshes of the Braganc¸a Peninsula, North Brazil. A synoptic distribution of sediment porewater salinity was produced with isolines derived from predicted porewater salinity values from a GISbased, multiple regression model. It includes a non-linear function of calculated inundation frequencies, the measured salinity distribution in the adjacent estuaries and sediment porewater salinities determined in the dry season. An excellent fit between measured and predicted porewater salinities was obtained. Highly significant correlations were found between vegetation height, inundation frequency and predicted porewater salinities. The relationship between vegetation height and predicted porewater salinities indicated the existence of at least three data 'clusters', which probably respond to different height to diameter-in-breastheight proportions according to age and environmental stress conditions. The porewater salinities produced by the model proved to be a solid proxy for the average stress situation of mangrove vegetation. The model offers good potential as a tool for analysing wetland dynamics, particularly at a synoptic, basin level.

- by Marcelo Cohen
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- Biological Sciences, Environmental Sciences, Data Clustering, Environmental Stress

The purposes of this retrospective study were to examine the multidimensional nature of soft tissue changes associated with mandibular advancement and genioplasty and to develop predictive models. Longitudinal lateral cephalograms of 62 nongrowing patients (27 men and 35 women) were taken in centric relation with the lips in repose within 4 weeks before surgery and at least 6 months postoperatively (median postsurgical duration was 11 months). The mandibular incisor and pogonion were advanced surgically approximately 6 mm and 11 mm, respectively. The lower lip lengthened slightly (2.5 Ϯ 3.8 mm), and its surface contour straightened because of thinning at labrale inferior (Ϫ2.8 Ϯ 2.0 mm); there was a slight thickening at the labiomental fold (1.0 Ϯ 2.3 mm) and a slight thinning at soft tissue pogonion (Ϫ0.8 Ϯ 2.2 mm). Multiple regression models (explaining from 80% to 94% and 66% to 82% of the variation for horizontal and vertical movements, respectively) showed that soft tissue response to advancement surgery depended on pretreatment tissue thickness, horizontal skeletal movement, vertical skeletal movement, and the position of the maxillary incisors. Similar amounts of variation were explained when the models were applied to an independent validation sample of 15 subjects. It was concluded that lower lip and chin response to mandibular advancement and genioplasty is multifactorial but can be accurately and reliably predicted. (Am J Orthod Dentofacial Orthop 2002;122:627-34)

- by Jeryl English
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- Dentistry, Biomedical Engineering, Forecasting, Adolescent

Gambling generates a significant source of income for certain countries/regions. There is a general assumption that a significant share of gambling receipts is originated on both domestic and international tourism flows. In this paper, we argue that while that might be the case for Las Vegas, Macau or Hong Kong, it is certainly not the case for Portugal, where the empirical evidence shows that gambling receipts are highly dependent on national per capita income (instead of international tourism). We use a multiple regression model, with the tourism receipts depending on both international tourism and national income. The GLS estimators, under the assumption of auto correlated errors, exhibit statistically relevant coefficients for GDP for all Casinos in Portugal. On the contrary, international tourism has shown to be insignificant in all Casinos except for the special case of the Madeira Island. Considering that the model shows gambling receipts depending strongly on domestic income...

Purpose -The purpose of this paper is to explore factors influencing Malaysian bank customers to choose Islamic credit cards. The bank customers generally aware of Islamic credit card facilities in Islamic banks but factors leading them to choose it are particularly unexplored. Given the importance of Islamic credit cards to Islamic banks, the study is aimed at explaining the effects of attitude, subjective norm and perceived financial cost on the Malaysian bank customers' behavioral intention to choose Islamic credit cards. Design/methodology/approach -Drawing upon the theory of reasoned action (TRA), this study suggests a modified model to examine the acceptance factors of attitude, subjective norm and perceived financial cost within a context of Islamic credit cards. This paper extends partial least squares (PLS) to examine the impacts of these factors on the intention to choose Islamic credit cards. The model is tested using a survey data from 257 respondents. Findings -The results reveal that attitude, subjective norm and perceived financial cost significantly influence the intention to choose Islamic credit card. Of these, attitude is first ranked as an influential factor in explaining one's intention to choose Islamic credit cards. All hypotheses are supported. The findings have proven the soundness of the TRA for study in the area of Islamic credit cards. Earlier works in Islamic credit cards have not ready to apply TRA in their works. The current research is thus closed the gap. Research limitations/implications -Pertaining to research limitations, this paper reveals two limitations owing to their future directions for future research on Islamic credit cards. This study indicates that its contributions are particularly confined to potential users in Eastern-Malaysia whilst those from Western-Malaysia are largely untapped. Further research is required to include users from both geographies. Owing to time and financial constraints, this study is only analyzed three factors in explaining the behavioral intention to choose Islamic credit cards. Therefore, future studies in this area should examine new potential factors contributing the receptivity. Practical implications -Findings generated from this study serve as a basis for more future works in the area of Islamic credit cards. The theory developed in the current study's model could also be generalized into other contexts of Islamic banking products and services. Practically, branch managers of Islamic banking institutions are of considerable importance to extend the findings of this study to better future planning of their Islamic credit card services. Originality/value -This study extends the applicability of the TRA model into a newly context of Islamic credit cards. Empirically, this study also integrates the effect of perceived financial cost on the intention to choose Islamic credit cards. This study offers insights with respect to factors affecting one's decision to choose Islamic credit cards.

- by Hanudin Amin
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- Islamic Banking, Customer Behavior, Design Methodology, Information Gathering

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- by Harsha Vardhan
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- Civil Engineering, Rock Mechanics, Variable Selection, Compressive Strength

The purpose of the study was to asses the potential use of pulse wave velocity (PWV) and digital volume pulse (DVP) as estimators of systolic (SBP) and diastolic (DPB) blood pressure. Single and multiple correlation studies were conducted, including biometric parameters and risk factors. Brachial-ankle PWV (baPWV) and DVP signals were obtained from a Pulse Trace PWV and Pulse Trace PCA (pulse contour analysis), respectively. The DVP (obtained by photoplethysmography), allowed stiffness (SI) and reflection indexes (RI) to be derived. The first study on 47 healthy volunteers showed that both SBP and DPB correlated significantly both with baPWV and SI. Multiple regression models of the baPWV and the waist-to-hip ratio (WHR) allowed SBP and DBP to be modeled with r = 0.838 and r = 0.673, respectively. SI results also employed WHR and modeled SBP and DBP with r = 0.852 and r = 0.663, respectively. RI did not correlate either with SBP or DBP. In order to avoid the use of ultrasound techniques to measure PWV, we then developed a custom-built system to measure PWV by photoplethysmography and validated it against the Pulse Trace. With the same equipment we conducted a second pilot study with ten healthy volunteers. The best SBP multiple regression model for SBP achieved r = 0.997 by considering the heart-finger PWV (hfPWV measured between R-wave and index finger), WHR and heart rate. Only WHR was significant in the DBP model. Our findings suggest that the hfPWV photoplethysmography signal could be a reliable estimator of approximate SBP and could be used, for example, to monitor cardiac patients during physical exercise sessions in cardiac rehabilitation.

- by Rafael Rodriguez
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- Algorithms, Cardiovascular, Ultrasound, Computer Simulation