Effects Of Other Independent Variables Research Articles

The association of ALT to HDL-C ratio with type 2 diabetes in 50–74 years old adults: a population-based study

There is limited information about the relationship between diabetes mellitus (DM) and ALT to HDL-C ratio. This study aims to investigate this relationship for the first time in Iran. The data of this study were taken from the third phase of the Shahroud Eye Cohort Study, which was conducted in 2019 with the participation of 4394 people aged 50–74. ALT and HDL-C levels were measured using a BT-1500 autoanalyzer. The mean ALT/HDL-C ratio was reported along with 95% confidence intervals (CI). The multiple logistic regression was used to examine the association between this ratio and DM, while controlling for the effects of other independent variables. The mean and standard deviation of the ALT/HDL-C ratio in all participants were 16.62 ± 11.22 (95% CI 16.28–16.96). The prevalence of DM was 34.7% and individuals with DM had a mean ALT/HDL-C ratio that was 1.80 units higher than those without diabetes (P < 0.001). Also, in individuals with DM, the HDL-C was found to be 0.035 (mmol/L) lower (P < 0.001), while ALT was 1.13 (IU/L) higher (P < 0.001) compared to those without diabetes. Additionally, after controlling for confounding factors, the odds of developing DM increased in a non-linear manner with an increase in the ALT/HDL-C ratio. Abdominal obesity, advanced age, female gender, and hypertension were also found to be associated with increased odds of DM. In conclusion, an increase in the ALT/ HDL-C ratiowas associated with higher odds of DM. This ratio can serve as an important predictor for diabetes mellitus.

Aspergillus niger as an eco-friendly agent for potassium release from K- bearing minerals: Isolation, screening and culture medium optimization using Plackett-Burman design and response surface methodology

The potential of Aspergillus niger, to enhance non-exchangeable potassium (K+) release from mineral structures were investigated as a cost-effective and environmentally friendly alternative to traditional chemical fertilizers. Optimizing the culture medium for maximum K+ release, alongside identifying potential mechanisms of action of the A. niger including the production of various organic acids and pH reduction in the minerals feldspar and phlogopite, were among the primary objectives of the present study. K+ dissolution from feldspar and phlogopite in the presence of Aspergillus niger were examined through a two-step experiment; impact of different carbon sources (glucose, sucrose, and fructose) on K+ release using the Plackett-Burman design (PBD) with 12 experimental runs and effect of other independent variables including pH (ranging from 5 to 10), carbon concentration (3–12.3 g l−1), and incubation time (5–18 days) on K+ release using the central composite design (CCD). Our results indicated that the PBD demonstrated a strong predictive capacity (RMSE = 0.012–0.018 g l−1 and R2 = 0.85–0.89) for K+ release. According to the CCD model, pH exerted a significant positive influence on increasing soluble K+ release (P < 0.001). The highest levels of K+ release (157.8 and 175.3 mg l−1 in feldspar and phlogopite, respectively) were observed at the central levels (0) of time and carbon source, and at the +α level (+1.68) of pH. Furthermore, based on the CCD model, the optimal conditions for achieving high K+ release from feldspar and phlogopite in a medium were pHs of 10.36 and 10.31, sucrose concentrations of 11.23 and 11.32 g l−1, and incubation times of 15 and 18 days, respectively. The determination coefficients of the CCD model indicated that 89.5% and 92.6% of the changes in soluble K+ for feldspar and phlogopite, could be explained by this model, respectively. In the current study, the production of organic acids and the resulting pH reduction, along with the reduction in mineral particle size in feldspar and phlogopite, were identified as potential mechanisms influencing the enhancement of potassium solubility. The predominant acids in both feldspar and phlogopite were lactic acid (70.9 and 69.15 mg l−1) and citric acid (40.48 and 22.93 mg l−1), although the production levels of organic acids differed in the two minerals. Overall, our findings highlight the potential of A. niger to proficiently release non-exchangeable potassium from mineral matrices, indicating its promising potential in agricultural applications.

The mediating effect of platform width on the size and shape of stone flakes.

To understand the ways in which past stone knappers controlled the morphology of the flakes they produced, archaeologists have focused on examining the effects of striking platform attributes on flake size and shape. Among the variables commonly considered, platform width has routinely been noted to correlate with flake size and hence used to explain past knapping behaviors. Yet, the influence of platform width on flake variation remains equivocal due to the fact that the attribute is not under the direct control of the knapper. Instead, platform width tends to be treated as a by-product of other independent knapping parameters, such as platform depth. In this study, we hypothesize that platform width acts as an intermediary that intervenes the effect of other independent variables on flake attributes. By analyzing experimental flakes produced under both controlled and replicative settings, the results support the hypothesis that platform width mediates the effect of platform depth on flake width, such that flakes with relatively larger platform widths are generally wider but no longer. This finding provides a way to incorporate platform width into discussions of the interrelationships among knapping variables, and highlights the importance of platform width for investigating how past knappers controlled flake production through platform manipulation.

INFLUENCES OF PARENTS AND PEERS ON ADOLESCENT SMOKING INITIATION: FINDINGS FROM A LONGITUDINAL STUDY IN KOTA TINGGI DISTRICT, JOHOR, MALAYSIA

&#x0D; &#x0D; &#x0D; Studies have shown that parents and peers are among the dominant factors that contribute to smoking initiation among non-smoking adolescents. The paucity of this information in Malaysia warrants a longitudinal study to determine the actual factors associated smoking initiation. The study aims to address the gaps in our knowledge on the factors that associated with smoking initiation among non-smoking school-going adolescents. We carried out a longitudinal study among non-smoking secondary school-going adolescents in Kota Tinggi district, Johor. A representative sample of 1682 was selected via multi-stage sampling and respondents were followed-up for a period of one year. A pre-validated questionnaire was used to collect data from the selected respondents and multivariable logistic regression was employed to determine the factors associated with smoking initiation among non-smoking school-going adolescents. Approximately 1 in 10 non-smoking school-going adolescents-initiated smoking at the end of follow-up. Having peers and a father who smokes were significantly associated with smoking in univariate analysis, similarly, a relationship was also observed in multivariable analysis between parents who smoked with smoking initiation after the effect of other independent variables were controlled (Adjusted relative risk: 1.81, 95% CI 1.06-2.95). The study revealed that parental influence was more dominant than peer influence with regard to smoking initiation. Therefore, intervention programmes should involve parents/guardians to enhance their chances of success and reduce the incidence of smoking among non-smoking school-going adolescents.&#x0D; &#x0D; &#x0D;

Prevalence and Associated Factors of Perinatal Asphyxia in Neonates Admitted to Ayder Comprehensive Specialized Hospital, Northern Ethiopia: A Cross-Sectional Study

Background Perinatal asphyxia is defined as the inability of the newborn to initiate and sustain enough respiration after delivery and is characterized by a marked impairment of gas exchange. It is one of the most common causes of neonatal mortality and morbidity. There are very few studies on perinatal asphyxia in Tigray, and so this study is aimed at assessing the prevalence and associated factors of perinatal asphyxia in Ayder Comprehensive Specialized Hospital NICU, Tigray, Ethiopia. Methods An institution-based cross-sectional study design was conducted among neonates admitted to Ayder Comprehensive Specialized Hospital from January 1, 2016, to December 30, 2017. Medical records of 267 neonates admitted to the neonatal intensive care unit were selected by a systematic sampling method, and relevant information was collected using a checklist. The data was analyzed using SPSS version 20. Descriptive statistics were computed to determine the prevalence of birth asphyxia and sociodemographic and obstetrics data. Binary logistic regression was used to test associations between the associated factors and perinatal asphyxia. First bivariate analysis was performed to assess the association without controlling the effect of other independent variables. Variables with P value < 0.25 were fitted to the multivariable binary logistic regression model. Finally, variables with P value < 0.25 were fitted to the multivariable binary logistic regression model. Finally, variables with Results Of the 267 neonates, 48 neonates had perinatal asphyxia, giving a prevalence of 18%. Prolonged labor (AOR = 5.19, 95% CI: 1.73-15.63, P value < 0.25 were fitted to the multivariable binary logistic regression model. Finally, variables with P value < 0.25 were fitted to the multivariable binary logistic regression model. Finally, variables with P value < 0.25 were fitted to the multivariable binary logistic regression model. Finally, variables with Conclusion and Recommendations. Prevalence and mortality of asphyxia were high. Prolonged labor, presence of meconium, and preeclampsia were determinant factors for birth asphyxia. Early detection and intervention of high-risk mothers should be carried out by health care providers, and mothers should be monitored with partograph during labor.

The Effects of Internal Marketing on Turnover Intentions in Knowledge Workers in the IT Sector

This study suggests applying the concept of internal marketing to combat turnover intentions in knowledge workers in the IT sector. Internal marketing sees all employees as the firm's customers. The major hypothesis examined here is that when employees feel that a firm considers and treats them like customers, it increases employment commitment and reduces turnover intentions. A multivariate hierarchical regression analysis and structural equation modelling (SEM) incorporating demographic, personal, organizational and external variables were used to identify the unique contribution of internal marketing to turnover intentions. The findings showed a negative correlation between internal marketing and turnover intention that contributed significantly to the explained variance beyond the effects of other independent variables. These results are discussed in the light of their theoretical and practical implications and in particular that IT organizations should consider adopting internal-marketing practices to reduce turnover intention and hence voluntary turnover.

Women empowerment through health seeking behavior in Bangladesh: Evidence from a national survey

Empowering women is an important subject to achieve targets for the Sustainable Development Goals (SDGs) of Bangladesh. There are several indicators to measure the empowerment of women. Health seeking information is one of the most important indicators in this regard. This study aims at identifying the levels and patterns of women empowerment in relation to health seeking behavior in Bangladesh. Bangladesh Demographic and Health Survey (BDHS) 2011 data was used for the study. A total of 16635 women of reproductive age were included in this study. Only 42% of recently married women participated in all the four discussions regarding their own health care, major household purchases, child health care, and visiting their family or relatives. Cross tabulation and logistic regression analyses were performed to know about women empowerment in relation to health seeking behavior on decision making, controlling the effect of other independent variables. The results showed that about 63% women were empowered (either by themselves or jointly with their husbands) to decide on their own healthcare seeking and around 67% in healthcare seeking for their children. Working women were 1.734 times more likely to seek their own healthcare than non-working women. Again rural women appeared to be 21% less likely to seek child healthcare compared to urban women. The results of this study showed that seeking health information empowered women to promote their self-confidence, filter the information, manage life problems successfully, feel strength against health problems and disabilities, and be encouraged to seek more information.South East Asia Journal of Public Health Vol.6(1) 2016: 40-45

Comprehensive reuse of drinking water treatment residuals in coagulation and adsorption processes

While drinking water treatment residuals (DWTRs) inevitably lead to serious problems due to their huge amount of generation and limitation of landfill sites, their unique properties of containing Al or Fe contents make it possible to reuse them as a beneficial material for coagulant recovery and adsorbent. Hence, in the present study, to comprehensively handle and recycle DWTRs, coagulant recovery from DWTRs and reuse of coagulant recovered residuals (CRs) were investigated. In the first step, coagulant recovery from DWTRs was conducted using response surface methodology (RSM) for statistical optimization of independent variables (pH, solid content, and reaction time) on response variable (Al recovery). As a result, a highly acceptable Al recovery of 97.5 ± 0.4% was recorded, which corresponds to 99.5% of the predicted Al recovery. Comparison study of recovered and commercial coagulant from textile wastewater treatment indicated that recovered coagulant has reasonable potential for use in wastewater treatment, in which the performance efficiencies were 68.5 ± 2.1% COD, 97.2 ± 1.9% turbidity, and 64.3 ± 1.0% color removals at 50 mg Al/L. Subsequently, in a similar manner, RSM was also applied to optimize coagulation conditions (Al dosage, initial pH, and reaction time) for the maximization of real cotton textile wastewater treatment in terms of COD, turbidity, and color removal. Overall performance revealed that the initial pH had a remarkable effect on the removal performance compared to the effects of other independent variables. This is mainly due to the transformation of metal species form with increasing or decreasing pH conditions. Finally, a feasibility test of CRs as adsorbent for phosphate adsorption from aqueous solution was conducted. Adsorption equilibrium of phosphate at different temperatures (10–30 °C) and initial levels of pH (3–11) indicated that the main mechanisms of phosphate adsorption onto CRs are endothermic and chemical precipitation; the surfaces are energetically heterogeneous for adsorbing phosphate.

The relative effects of core surface morphology on flake shape and other attributes

It is long been thought that many flake attributes, including both size and shape, are largely due to the morphology of a core’s flaking surface, yet this has never been tested under strictly controlled conditions. Using molded glass cores with surface morphologies that highly resemble prehistoric ones, this experiment demonstrates that while core surface morphology does exhibit some influence on flake size and shape, a high degree of variation in flakes produced with the same core surface morphology shows that the effects of other independent variables, such as exterior platform angle and platform depth, have an even stronger effect. A major implication of these results is that current approaches to reconstruct prehistoric knapping strategies are overlooking significant sources of variation.

Somatic cell count, lactoferrin and NAGase activity in milk of infected and non-infected udder halves of dairy goats

Based on a repeated sampling the influence of an intramammary infection on the somatic cell count (SCC), the content of lactoferrin (Lf) and the activity of N-acetyl-β- d-glucosaminidase (NAGase) in goats’ milk was investigated. 58 dairy goats (German Improved Fawn) were sampled weekly over 3 consecutive weeks and the udder halves were classified according to the results of the bacteriological analysis of the foremilk samples and the results of their parallel half into three groups: uninfected halves with an uninfected parallel half (NoInf/NoInf), uninfected halves with an infected parallel half (NoInf/Inf) and infected halves with an uninfected parallel half (Inf/NoInf). None of the goats had two infected halves, thus, this group was omitted. 15 out of the 58 goats were infected on one udder half. The bacteria detected were Staphylococcus aureus ( n = 4), coagulase-negative staphylococci ( n = 7), corynebacteria ( n = 3) and esculin-positive streptococci ( n = 1). Log 10 SCC, log 10 Lf and log 10 NAGase were strongly correlated to each other and changed over the sampling period but not uniformly, revealing a significant effect of the sampling day on the variables ( F 6,98 = 29.13, p < .001). This could not be explained by an underlying effect due to the stage of lactation or the estrus season the animals were in, and therefore needs further investigation. The infection status had a significant effect on log 10 SCC ( F 2,103 = 20.22, p < .001), log 10 Lf ( F 2,103 = 11.18, p < .001) and log 10 NAGase ( F 2,103 = 12.06, p < .001). Inf/NoInf differed significantly from NoInf/NoInf as well as NoInf/Inf for log 10 SCC ( p < .01) and log 10 Lf ( p < .001) whereas the NoInf/NoInf did not differ from NoInf/Inf indicating that the infected halves did not influence their uninfected parallel half. For log 10 NAGase this was different: infected halves differed significantly from NoInf/NoInf ( p < .01) but not from NoInf/Inf which might be caused by a dependency of the udder halves. Results support the approach to monitor mastitis in goats by means of Lf or NAGase instead of SCC. Further studies should explore the effect of other independent variables, such as estrus, on these indicators and aim for thresholds indicating an intramammary infection.

Characteristics of Nursing Home Social Services Directors: How Common is a Degree in Social Work?

To report the percentage of nursing homes whose social services director has a degree in social work, to report the characteristics of social service directors, and to describe the characteristics of nursing homes most likely to employ a degreed social worker. These questions are important because social workers are core members of the interdisciplinary team in nursing homes and have responsibilities for the psychosocial well-being of residents. Cross-sectional nationally representative survey of 1071 social service directors employed in US nursing homes certified to receive Medicare and/or Medicaid. Most nursing homes do employ at least one (and typically only one) social service staff person. Most are employed full-time and half have a degree in social work. About 20% do not have a college degree. The vast majority of social service directors are white and are women. Close to 40% are licensed social workers. Full-time salaries varies enormously from less than $15,000 to over $60,000 per year. Most do not belong to an organization that helps them keep apprised of developments in nursing home social services. Using logistic regression and controlling for the effects of other independent variables, for-profit nursing homes with fewer than 121 beds, in sparsely populated counties in the West are the least likely to hire a degreed social worker as social service director. The wide range in educational preparedness and salary indicates 2 roles: a social work role and a social services role. The different roles have implications for initial role preparation and continuing education. Clear communication about the role expectations associated with social services and social work would benefit residents, family, staff, and physicians, who would then be better prepared to draw on their skills in helping to meet the psychosocial needs of residents.

Patient/enrollee satisfaction with healthcare and health plan

The findings of the present study show that healthier patients, older patients, males, those with a lower level of education, those who perceive system performance to be high and those with lower levels of system usage are more satisfied with both their healthcare and health plan than their opposite counterparts. Regarding the incremental effects of these variables, the most striking finding is the strong, pivotal role of physicians in influencing patient satisfaction with healthcare. In regard to satisfaction with health plan, the extent of the problems that members have had with their health plan has by far the largest statistical influence on their satisfaction with that plan. The effects of other independent variables including the three demographic variables, self‐stated health status, number of visits to doctor’s office or clinic, and issues related to access, though significant, show relatively small statistical influences on overall satisfaction with healthcare and health plan.

Clinical, provider and sociodemographic predictors of late initiation of antenatal care in England and Wales

Objective To identify factors that are predictive of late initiation of antenatal care in England and Wales. Design A multivariate binomial regression model was constructed to examine the association between clinical, provider and sociodemographic characteristics and late initiation of antenatal care. Setting Nine maternity units in Northern England and North Wales. Population A total of 20,771 women with a singleton pregnancy who delivered a liveborn or stillborn baby between 1 August 1994 and 31 July 1995. All analyses were based on the 17,765 (85.5%) women for whom information on gestational age at initial presentation for antenatal care and other variables incorporated into the regression model was retrievable from the case records Results Primiparous women of high obstetric risk were 13.4% more likely to initiate antenatal care after 10 weeks of gestation than a low risk reference group (adjusted OR 1.134, 95% CI 1.011, 1.272; P = 0.0312), and 34.3% more likely to initiate antenatal care after 18 weeks of gestation (adjusted OR 1.343, 95% CI 1.046, 1.724; P = 0.0208). This association between high obstetric risk status and late initiation of antenatal care was not replicated among multiparous women. When the effects of other independent variables on gestational age at booking were examined, the following characteristics were associated with failure to initiate antenatal care by 10 weeks of gestation ( P ≤ 0.05): maternal age at booking, smoking status, ethnicity, type of hospital at booking, the planned pattern of antenatal care and the planned place of delivery. Adopting a criterion of 18 weeks of gestation exacerbated the association between clinical and sociodemographic characteristics and late initiation of antenatal care, but appeared to dilute the association between provider characteristics and late initiation of antenatal care. Conclusions There is a pressing need for further research to identify the specific concerns of late bookers, to identify areas where new interventions might encourage the uptake of services and to gauge the likely impact of increased dissemination of information about the availability of antenatal care services.

Clinical, provider and sociodemographic predictors of late initiation of antenatal care in England and Wales.

To identify factors that are predictive of late initiation of antenatal care in England and Wales. A multivariate binomial regression model was constructed to examine the association between clinical, provider and sociodemographic characteristics and late initiation of antenatal care. Nine maternity units in Northern England and North Wales. A total of 20,771 women with a singleton pregnancy who delivered a liveborn or stillborn baby between 1 August 1994 and 31 July 1995. All analyses were based on the 17,765 (85.5%) women for whom information on gestational age at initial presentation for antenatal care and other variables incorporated into the regression model was retrievable from the case records. Primiparous women of high obstetric risk were 13.4% more likely to initiate antenatal care after 10 weeks of gestation than a low risk reference group (adjusted OR 1.134, 95% CI 1.011, 1.272; P = 0.0312), and 34.3% more likely to initiate antenatal care after 18 weeks of gestation (adjusted OR 1.343, 95% CI 1.046, 1.724; P = 0.0208). This association between high obstetric risk status and late initiation of antenatal care was not replicated among multiparous women. When the effects of other independent variables on gestational age at booking were examined, the following characteristics were associated with failure to initiate antenatal care by 10 weeks of gestation (P < or = 0.05): maternal age at booking, smoking status, ethnicity, type of hospital at booking, the planned pattern of antenatal care and the planned place of delivery. Adopting a criterion of 18 weeks of gestation exacerbated the association between clinical and sociodemographic characteristics and late initiation of antenatal care, but appeared to dilute the association between provider characteristics and late initiation of antenatal care. There is a pressing need for further research to identify the specific concerns of late bookers, to identify areas where new interventions might encourage the uptake of services and to gauge the likely impact of increased dissemination of information about the availability of antenatal care services.

Comparison and Contrast of Push and Pull Motivational Effects on Trip Behavior: An Application of a Multinomial Logistic Regression Model

Within the context of the multidestinations and multiactivities, the present study focused on the comparison between the push and pull motives in terms of the influences on destination choice and vacation activity of German pleasure travelers to the US, Canada, and Asia. Employing a multinomial logistic regression and OLS regression techniques, this study assessed the effect of each motivational factor on destination choice and vacation activity participation. The effect of other independent variables, such as length of stay, travel budget, travel mode, and sociodemographics, was also investigated. The results of this study indicated that: (1) in general, pull factors exerted more influence on destination choice than push factors, and different pull factors motivated travelers to select different destinations, (2) motivational factors were the most significant determinants among others, and (3) a typology of vacation activity patterns based on need-satisfying property of motivation may exis

Wealth Flow and Fertility Decline in Rural Kenya, 1981-92: A Reassessment of the Evidence

In 1981 and 1992, identical questionnaires measuring lineal and lateral wealth flows and emotional nucleation were administered to comparable samples of male household heads in rural Kenya. The 1981 results, showing limited evidence of economic or emotional nucleation within the household, were consistent with prevailing high fertility. By 1992 desired and observed fertility had declined significantly, but nucleation levels remained the same. The question then arose as to whether our bivariate measurements had been too coarse to detect subtle shifts in nucleation and/or the simultaneous effect of other independent variables. To resolve these issues, we re-examined our 1981 and 1992 data sets using regression analysis. The findings suggest that the independent contribution of wealth flow and emotional nucleation variables to explained variance in the desired number of children by rural male heads of households was limited, being approximately seven to 10 percent in 1981 and 10 to 18 percent in 1992. However, we observed that the independent variables picking up the explanatory slack in the current exercise were largely ideational in nature, having to do with the expectation of future child support, education, form of marriage, and spousal perception, communication, and consensus on key family size and family planning variables.

Full-Information Models for Multiple Psychometric Tests: Annualized Rates of Change in Normal Aging and Dementia

The rates of change for five widely used psychometric tests were analyzed to compare how much more variance reduction can be achieved using full-information methods relative to the single-equation methods previously used in dementia research. Nondemented controls and subjects with Alzheimer disease (AD), probable/ possible vascular dementia (VD), or mixed dementia (MD) were evaluated. A cohort design was followed, with follow-up of three demented groups and one normal control group; data were analyzed in a multiple-equation regression model estimated with full-information methods. The study was conducted at Alzheimer's Disease Research Center sites at the University of California, Irvine, and at the University of Southern California. In all, 226 patients and controls who had completed initial assessment and at least one annual reassessment were included in the study. Dependent variables were annualized rates of change in the Mini-Mental State Examination (MMSE), the Short-Blessed Dementia Rating Scale (DRS), the Consortium to Establish a Registry for Alzheimer's Disease drawings test (CD), the WAIS-R Block Design test (WRB), and the Boston Naming Test (BNT). Independent variables were dementia severity, diagnosis (AD, VD, MD, or control), sex, age, marital status, education, and age at onset. Full-information methods reduced the variance in the change scores by > or = 25% compared with previous studies. The model's prediction of a test's rate of change was almost entirely due to dementia stage and diagnosis. The effects of other explanatory variables (sex, marital status, age, and education) were weak and statistically insignificant. When the effects of other independent variables were controlled, AD and MD patients were found to decline at significantly faster rates than VD patients. Full-information methods, relative to single-equation methods, substantially reduce the variance of rates of change for multiple psychometric tests. They do so by simultaneously considering the correlated error terms in the regression for each dependent psychometric change score variable. The robustness of these results to minor variations in follow-up time suggests that annualization is a reasonably valid procedure for making change scores comparable. This study's results suggest that change scores in psychometric tests provide information that can be used to aid differential diagnosis. However, the large variances of change scores preclude many other uses. Finally, since standardization of psychometric change scores translates all tests to the same scale (0-100%), standardized change scores are easier to interpret. The analysis of standardized change scores deserves further investigation.

Correlations between parameters of body selenium status and peripheral thyroid parameters in the low selenium region.

The following were measured in 380 male and female inhabitants of Prague (n the age range 6-65 years):selenium in serum and urine, iodine in urine, thyroid-stimulating hormone, thyroid volume, thyroxine (T4), triiodothyronine (T3), ankle jerk time, pulse rate and body fat. Correlations were calculated to assess the influence of Se upon the thyroid hormone parameters and their peripheral effects in Se-deficient regions both by using the linear correlation analysis and by using the multiple linear correlation analysis and the analysis of variance. Many significant linear correlations were found for whole groups of examined persons, for the individual groups (boys, men, girls and women) as well as for subgroups, according to the age and sex. We conclude, from the analytical results of Se indices (serum, hair, urine) reported previously, and on the basis of the statistical demonstration of the influence of selenium upon thyroid hormone levels and the peripheral effects in the group of Prague inhabitants in connection with the previously documented role of Se in pathways resulting in the synthesis of physiologically active thyroid hormone, that inhabitants of Prague are selenium deficient. Concurrent deficiency of selenium may modify and even worsen iodine deficiency disorders of various stages. Multiple linear correlation analysis followed by analysis of variance of subgroups indicated a coincidence of the effects of some measured parameters upon the peripheral manifestation of thyroid hormone state as well as highlighting the effect of other independent variables of thyroid hormone metabolism than those measured in the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of social context, reinforcer probability, and reinforcer magnitude on humans' choices to compete or not to compete.

In the first two experiments, subjects' choices to earn points (exchangeable for money) either by competing with a fictitious opponent or by not competing were studied. Buskist, Barry, Morgan, and Rossi's (1984) competitive fixed-interval schedule was modified to include a second response option, a noncompetitive fixed-interval schedule. After choosing to enter either option, the opportunity for reinforcers became available after the fixed-interval's duration had elapsed. Under the no-competition condition, points were always available after the interval had elapsed. Under the competition condition, points were available based on a predetermined probability of delivery. Experiments 1 and 2 examined how reinforcer probabilities and reinforcer magnitudes affected subjects' choices to compete. Several general conclusions can be made about the results: (a) Strong preferences to compete were observed at high and moderate reinforcer probabilities; (b) competing was observed even at very low reinforcer probabilities; (c) response rates were always higher in the competition component than in the no-competition component; and (d) response rates and choices to compete were insensitive to reinforcer-magnitude manipulations. In Experiment 3, the social context of this choice schedule was removed to determine whether the high levels of competing observed in the first two experiments were due to a response preference engendered by the social context provided by the experimenters through instructions. In contrast to the first two experiments, these subjects preferred the 60-s fixed-interval schedule (formerly the no-competition option), indicating that the instructions themselves were responsible for the preference to compete. This choice paradigm may be useful to future researchers interested in the effects of other independent variables (e.g., drugs, social context, instructions) on competitive behavior.

Sexual knowledge among Norwegian adolescents

Sexual knowledge among Norwegian adolescents was studied. The data stemmed from a nationwide postal survey of 3000 Norwegian adolescents aged 17-19 years, yielding a response rate of 62·8%. Information of 16 sexual knowledge items was collected. The results showed considerable knowledge gaps among adolescents on sexual physiology and anatomy, sexually transmitted diseases, and fecundation/contraception. The level of sexual knowledge was higher among girls than boys, and increased with increasing age. Furthermore, sexual knowledge was positively associated with educational plans, frequency of discussing sex with friends, and experience of sexual intercourse. Sexual knowledge did not predict contraception use, when the effects of other independent variables were controlled for. The results of the study clearly demonstrate the need for further information and education efforts to increase sexual knowledge among adolescents. The potential adequacy of efforts which both activate and increase the quality of peer communication on sexual issues is addressed.