Search Results (10)

Background/Objectives: The aim of this study was to identify and assess the independent risk factors and potential predictors for endo-periodontal lesions (EPLs) in endodontically treated teeth with periapical pathology. Methods: The study group included 90 patients (35 men, 55 women; mean age 47.96 ± 13.495 years) with 126 endodontically treated teeth. Following clinical examinations and radiologic evaluation, 50 patients were diagnosed with endo-periodontal lesions (EPLs) in 64 molars (test group); the control group included 62 endodontically treated teeth without EPLs diagnosed in 40 patients. The independent variables were assessed as risk factors for EPLs. The relationship between patients’ demographic and clinical features and endo-periodontal status was assessed using Chi-squared tests for categorical variables and Student’s t- or Mann–Whitney tests for continuous variables, depending on data distribution. The potential risk factors were characterized by calculating Odds Ratios (ORs) with 95% confidence intervals. The variables included in the multivariate logistic regression model were selected based on their clinical relevance and statistical significance in the univariate analysis. To evaluate the combined effect of the identified risk factors, a binary logistic regression model was constructed using the Enter method. Results: Out of the 126 endodontically treated molars with periapical pathology, 64 teeth (50.8%) were diagnosed with endo-periodontal lesions (EPLs). Patients aged ≥60 years were significantly more represented in the EPL group (32.8%) compared to the control group (12.9%) (p = 0.024). Probing pocket depth ≥ 4 mm was present in 85.9% of teeth with EPLs versus only 30.6% in teeth without EPLs (p < 0.001). Probing pocket depth (PPD) ≥ 4 mm was the strongest predictor (OR = 13.830) and remained significant after adjustment in multivariate analysis (OR = 6.585). PPD ≥ 3.625 mm showed a strong association in univariate analysis (OR = 12.587) and preserved significance in the multivariate model (OR = 6.163). Conclusions: This study highlights age ≥ 60 years and PPD ≥ 4 mm as the most significant independent risk factors for EPLs, emphasizing the need for early periodontal assessment in endodontically treated teeth with periapical pathology. While PPD greater than 3.625 mm is a strong indicator of the presence of EPLs, other factors such as MBL (marginal bone loss) and occlusal considerations appear to have indirect roles in EPL development in endodontically treated teeth with periapical lesions. Full article

Background and Objectives: Caregiving for geriatric patients is essential for ensuring the well-being and quality of life of older adults. Family caregivers play a crucial role, but they often face a significant burden that can lead to adverse mental health outcomes, including depression. This study aimed to estimate the prevalence of depression among caregivers of geriatric patients in Jeddah, Saudi Arabia, and to analyze its association with caregiver burden and various socio-demographic and caregiving parameters. Methods: A cross-sectional study was conducted in Jeddah, Saudi Arabia, between January and March 2024. Adult caregivers of geriatric patients were recruited through various social media platforms. Data were collected via an electronic questionnaire that included demographic information, caregiving parameters, the Patient Health Questionnaire-9 (PHQ-9) for depression screening, and the Zarit Burden Interview (ZBI-12) for caregiver burden assessment. Data were analyzed using descriptive statistics, chi-square tests, and multivariate logistic regression. Results: Of the 269 participants, the average age was 32 years, and the gender distribution was nearly balanced. The prevalence of depression (PHQ-9 score ≥ 10) among caregivers was 45.4% (95% CI: 39.3, 51.5%). Significant factors associated with higher depression scores included younger age, female gender, single status, being a student, low income, and caregiving burden. In the multivariate analysis, female gender (OR 2.50, 95% CI 1.30–4.80) and caregiving burden (mild-to-moderate burden: OR 6.18, 95% CI 2.94–13.00; high burden: OR 22.75, 95% CI 8.75–59.13) were independent predictors of depression. Conclusions: The study highlights the high prevalence of depression among caregivers of geriatric patients in Jeddah and underscores the significant impact of caregiving burden on mental health. These findings emphasize the need for targeted interventions, such as mental health support, respite care programs, and culturally sensitive educational training, to mitigate caregiver burden and enhance the well-being of caregivers. Full article

Peer rejection occurs at all stages of education, including infant education, and entails serious consequences, both immediately and in the future, in all areas of children’s development. This study aims to gain insight into the link between peer rejection and academic performance, mediated by the presence of special educational needs (SEN). The study involved the participation of 758 students (397 male) in the second cycle of early childhood education (3–6 years old) in Spain who were given a sociometric test to ascertain the sociometric distribution of each classroom. Their teachers were asked to record the academic performance of each student in terms of language, logic-mathematics, psychomotor ability, and overall performance. Teachers were also asked to identify whether or not students had SEN. By applying a multivariate variance analysis (MANOVA) that considered the presence or otherwise of peer rejection and the presence or otherwise of SEN as independent variables, results show that rejected students display poorer academic performance in all areas. The same was also found to be true for those with SEN. As a result, rejected students with SEN are seen to exhibit the poorest academic performance and suffer two-fold stigmatisation. Full article

We show that the one-way ANOVA and Tukey–Kramer (TK) tests agree on any sample with two groups. This result is based on a simple identity connecting the Fisher–Snedecor and studentized probabilistic distributions and is proven without any additional assumptions; in particular, the standard ANOVA assumptions (independence, normality, and homoscedasticity (INAH)) are not needed. In contrast, it is known that for a sample with $k>2$ groups of observations, even under the INAH assumptions, with the same significance level $\alpha$, the above two tests may give opposite results: (i) ANOVA rejects its null hypothesis $H_0^A:{\mu }_1=\dots ={\mu }_k$, while the TK one, $H_0^{\mathit{TK}}(i,j):{\mu }_i={\mu }_j$, is not rejected for any pair $i,j\in \{1,\dots ,k\}$; (ii) the TK test rejects $H_0^{\mathit{TK}}(i,j)$ for a pair $(i,j)$ (with $i\ne j$), while ANOVA does not reject $H_0^A$. We construct two large infinite pseudo-random families of samples of both types satisfying INAH: in case (i) for any $k\ge 3$ and in case (ii) for some larger k. Furthermore, case (ii) ANOVA, being restricted to the pair of groups $(i,j)$, may reject equality ${\mu }_i={\mu }_j$ with the same $\alpha$. This is an obvious contradiction, since ${\mu }_1=\dots ={\mu }_k$ implies ${\mu }_i={\mu }_j$ for all $i,j\in \{1,\dots ,k\}.$ Such contradictions appear already in the symmetric case for $k=3$, or in other words, for three groups of $d,d$, and c observations with sample means $+1,-1$, and 0, respectively. We outline conditions necessary and sufficient for this phenomenon. Similar contradictory examples are constructed for the multivariable linear regression (MLR). However, for these constructions, it seems difficult to verify the Gauss–Markov assumptions, which are standardly required for MLR. Mathematics Subject Classification: 62 Statistics. Full article

Self-reported fruit and vegetable (FV) consumption in children has limitations that could be overcome with objective measures that are easy to implement. The Veggie Meter (VM) is a non-invasive portable device that measures skin carotenoid levels, a concentration biomarker of usual FV intake. While VM has been used to measure FV consumption in adults, few studies have explored its use in elementary school settings. Designing research studies using the VM with elementary school-age children requires an understanding of how well this device can be used in a school setting and of the distribution of VM scores in this population. We used VM to measure skin carotenoids in a diverse sample of 143 elementary school children who also answered commonly asked questions about consumption frequency of FV the previous day. Multivariable regression was used to assess the independent association of demographic variables with VM scores. VM scores were also compared with student-reported FV intake. There was a weak but statistically significant correlation between reported frequency of total vegetable consumption the previous day and observed VM scores (r = 0.174, p = 0.042). This study provides an example of the successful use of the VM in a school setting to collect an objective measure of FV intake and provides important description of data that can inform future studies. Full article

Universities strive to ensure quality education focused on the diversity of the student body. According to experiential learning theory, students display different learning preferences. This study has a three-fold objective: to compare learning styles based on personal and educational variables, to analyze the association between learning styles, the level of academic performance, and consistency of performance in four assessment methods, and to examine the influence of learning dimensions in students with medium-high performance in the assessment methods. An interdisciplinary approach was designed involving 289 psychology, early childhood education and primary education students at two universities in Spain. The Learning Style Inventory was used to assess learning styles and dimensions. The assessment methods used in the developmental psychology course included the following question formats: multiple-choice, short answer, creation-elaboration and an elaboration question on the relationship between theory and practice. Univariate analysis, multivariate analysis, and binomial logistic models were computed. The results reveal Psychology students to be more assimilative (theoretical and abstract), while early childhood and primary education students were evenly distributed among styles and were more divergent and convergent (practical) in absolute terms. In addition, high scores in perception (abstract conceptualization) were associated with a high level of performance on the multiple-choice tests and the elaboration question on the relationship between theory and practice. Abstract conceptualization was also associated with medium-high performance in all assessment methods and this variable predicted consistent high performance, independent of the assessment method. This study highlights the importance of promoting abstract conceptualization. Recommendations for enhancing this learning dimension are presented. Full article

Brushing at least twice a day is one of the most effective methods for the prevention of dental caries and oral diseases. The aim of the present study was to determine the prevalence and correlates of poor oral hygiene in Mongolian school-going students. A secondary analysis of nationally representative data from the 2013 Mongolian Global School-based Health Survey (GSHS) was performed. In the survey, a questionnaire was completed by 5393 students aged 12–16 years old. The prevalence of poor oral hygiene and its association with some independent variables were analyzed by frequency distribution, chi-squared test, and logistic regression. The overall prevalence of poor oral hygiene was 33%. In the multivariate analysis, male students, inadequate fruit and vegetable intake, parents’ smoking, being exposed to second-hand smoke, poor parental supervision and connectedness, physical inactivity, and sedentary behavior were significantly associated with poor oral hygiene. Meanwhile, students who ate fast food and drank carbonated soft drink were found to be less likely to be poor tooth-brushers in 2013. Various determinants were identified in connection with poor oral hygiene. Based on these findings, it is recommended that an oral health promotion program should be combined with general health promotion and lifestyle intervention programs for this target population. Full article

Objective: To determine the characteristics of members of online diabetes communities as well as those factors affecting the provision and acceptance of social support. Methods: A cross-sectional STAR questionnaire survey was conducted among patients with diabetes who were members of online diabetes groups. Univariate and multivariate binary logistic regression analysis were adopted to explore the relative analysis of providing and accepting social support compared with the characteristics of members in virtual diabetics’ groups. Results: A total of 1297 respondents were collected. The map distribution of patients in China was mainly located in the Guangdong, Jiangsu, Shandong, Henan, and Hebei provinces. As for their demographic characteristics, respondents had diabetes or prediabetes and were between the ages of 21 and 50 years (Median age was 35.0 (interquartile range from 28.0 to 44.0)). Most respondents were married and lived in cities. The education level of patients was mainly distributed throughout junior high, technical secondary, high school, junior college, and undergraduate levels. Age, marital status, and education level varied by gender, and the total score of the patients aged 41 to 50 for social support had a statistical significance between male and female. In addition, when group members were in junior high school or below, or were undergraduate students, their total social support scores varied by gender. Binary logistic regression showed that in 21 independent variables the total score and the total score grade of relationship intensity in the online group and reorganize of age were significant. The patients’ social support acceptance of the map of respondents score grading of relationship intensity in the online group was 5.420 times higher than that of the lower score grading of relationship intensity in the group. At the same time, the patients’ social support acceptance of the patients at the age of less than or equal to 31 years old was 19.608 times higher than that of group members aged more than 31 years old. Conclusion: Age and education background of the patients affects scores of social supports between males and females. The higher the total score and the score grade of relationship intensity in the online group, the higher the patients’ social support acceptance. The younger patients had a better utilization of social support. Full article

Determining distributions of the functions of random variables is one of the most important problems in statistics and applied mathematics because distributions of functions have wide range of applications in numerous areas in economics, finance, risk management, science, and others. However, most studies only focus on the distribution of independent variables or focus on some common distributions such as multivariate normal joint distributions for the functions of dependent random variables. To bridge the gap in the literature, in this paper, we first derive the general formulas to determine both density and distribution of the product for two or more random variables via copulas to capture the dependence structures among the variables. We then propose an approach combining Monte Carlo algorithm, graphical approach, and numerical analysis to efficiently estimate both density and distribution. We illustrate our approach by examining the shapes and behaviors of both density and distribution of the product for two log-normal random variables on several different copulas, including Gaussian, Student-t, Clayton, Gumbel, Frank, and Joe Copulas, and estimate some common measures including Kendall’s coefficient, mean, median, standard deviation, skewness, and kurtosis for the distributions. We found that different types of copulas affect the behavior of distributions differently. In addition, we also discuss the behaviors via all copulas above with the same Kendall’s coefficient. Our results are the foundation of any further study that relies on the density and cumulative probability functions of product for two or more random variables. Thus, the theory developed in this paper is useful for academics, practitioners, and policy makers. Full article

To model multivariate, possibly heavy-tailed data, we compare the multivariate normal model (N) with two versions of the multivariate Student model: the independent multivariate Student (IT) and the uncorrelated multivariate Student (UT). After recalling some facts about these distributions and models, known but scattered in the literature, we prove that the maximum likelihood estimator of the covariance matrix in the UT model is asymptotically biased and propose an unbiased version. We provide implementation details for an iterative reweighted algorithm to compute the maximum likelihood estimators of the parameters of the IT model. We present a simulation study to compare the bias and root mean squared error of the ensuing estimators of the regression coefficients and covariance matrix under several scenarios of the potential data-generating process, misspecified or not. We propose a graphical tool and a test based on the Mahalanobis distance to guide the choice between the competing models. We also present an application to model vectors of financial assets returns. Full article