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Open Access June 02, 2025

Residual Sets and the Density of Binary Goldbach Representations

Abstract A residual-set framework is introduced for analyzing additive prime conjectures, with particular emphasis on the Strong Goldbach Conjecture (SGC). For each even integer En4, the residual set [...] Read more.
A residual-set framework is introduced for analyzing additive prime conjectures, with particular emphasis on the Strong Goldbach Conjecture (SGC). For each even integer En4, the residual set (En)={Enp p<En,p} is defined, and the universal residual set E=En(En) is constructed. It is shown that E contains infinitely many primes. A nontrivial constructive lower bound is derived, establishing that the number of Goldbach partitions satisfies G(E)2 for all E8, and that the cumulative partition count satisfies ENG(E)N2log4N. An optimized deterministic algorithm is implemented to verify the SGC for even integers up to 16,000 digits. Each computed partition En=p+q is validated using elliptic curve primality testing, and no exceptions are observed. Runtime variability observed in the empirical tests corresponds with known fluctuations in prime density and modular residue distribution. A recursive construction is formulated for generating Goldbach partitions, using residual descent and leveraging properties of the residual sets. The method extends naturally to Lemoine's Conjecture, asserting that every odd integer n7 can be expressed as n=p+2q, where p,q. A corresponding residual formulation is developed, and it is proven that at least two valid partitions exist for all n9. Comparative analysis with the Hardy-Littlewood and Chen estimates is provided to contextualize the cumulative growth rate. The residual-set methodology offers a deterministic, scalable, and structurally grounded approach to additive problems in prime number theory, supported by both theoretical results and large-scale computational evidence.
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Open Access May 13, 2025

Geochemistry distributions and statistics analysis of REE in stream sediments from the watershed west of Mambaka (Adamawa Plateau, Cameroun)

Abstract The Mambaka watershed is extends between latitudes 1 3°45'E and 14°15'E and longitudes 7°16'N and 6°45'N. The geology, various tectonic and structural events that have affected the Adamawa Plateau in Cameroon make it rich in multi-substance mining. The objective of this study is to map rare earth (REE) geochemical anomalies in the sediments of the watershed streams west of Mambaka, and to trace [...] Read more.
The Mambaka watershed is extends between latitudes 1 3°45'E and 14°15'E and longitudes 7°16'N and 6°45'N. The geology, various tectonic and structural events that have affected the Adamawa Plateau in Cameroon make it rich in multi-substance mining. The objective of this study is to map rare earth (REE) geochemical anomalies in the sediments of the watershed streams west of Mambaka, and to trace their origins and geochemical processes. Predictive maps from inverse distance interpolations (IDW), factor analysis (F1) or principal component analysis (PCA) and hierarchical bottom-up classification maps provided a better understanding of the central tendency, distribution and dispersion of REE in the samples and in the study area, based on standard deviation and variance values that generated two factors F1 (Ho-Tm-Er-Yb-Lu-Dy-Tb-Gd-Eu-Sm) and F2 (Pr-Nd-Ce-La-Sm) representing 92.44% of the total cumulative variance. The ratios Ce/Ce* > 0.78 and Eu/Eu* > 1 demonstrate positive anomalies in Ce and Eu, and clear differentiation. The normalized concentrations used to calculate fractionation ratios show that the values for LaN/YbN (0.58 to 1.34), LaN/SmN (0.61 to 0.88) and LaN/LuN (0.62 to 1.43) suggest higher fractionation in SS09 and lower fractionation in SS01. Similarly, the ratios La/Lu (61.71 to 143.46), La/Yb (9.00 to 20.72), La/Sm (4.02 to 5.83) and La/ Lu (61.71 to 143.46) confirm these higher ratios in SS09 and lower in SS01. The REE in the study area comes from hydrothermal processes based on high lineament densities at sampling points in igneous rocks with a mean ∑REE value of between 174-219 ppm.
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Open Access February 21, 2025

Diminished Returns of Educational Attainment on Unpaid and Paid Maternity Leave of Mothers Giving Birth in Poverty

Abstract Background: Maternity leave, whether paid or unpaid, is a critical resource that can significantly impact maternal well-being and newborn outcomes. However, its availability and utilization among mothers living in poverty remain understudied. Education is widely recognized as a key factor that increases access to both paid and unpaid leave. However, the theory of Minorities’ [...] Read more.
Background: Maternity leave, whether paid or unpaid, is a critical resource that can significantly impact maternal well-being and newborn outcomes. However, its availability and utilization among mothers living in poverty remain understudied. Education is widely recognized as a key factor that increases access to both paid and unpaid leave. However, the theory of Minorities’ Diminished Returns (MDRs) posits that structural racism, segregation, and labor market discrimination limit the benefits of socioeconomic resources, such as education, for Black and Latino individuals. This suggests that the effects of education on maternity leave may not be uniform across racial and ethnic groups. Objective: This study aimed to examine the MDRs of education on access to unpaid and paid maternity leave among Black and Latino mothers compared to White mothers giving birth while living in poverty. Methods: We utilized baseline data from the Baby’s First Years Study (BFY), a longitudinal investigation of the effects of poverty on child development. The sample consisted of 1,050 mothers living in poverty who had recently given birth. Maternity leave (paid and unpaid) was assessed via self-report, and educational attainment was measured in years of schooling. Structural equation modeling (SEM) and interaction terms were employed to analyze racial and ethnic differences in the relationship between education and access to maternity leave. Results: Educational attainment was positively associated with access to unpaid maternity leave for the overall sample of mothers giving birth in poverty, but this association was weaker for Black and Latino mothers compared to non-Latino White mothers. Education did not significantly increase the likelihood of paid maternity leave, and there were no group differences for this association. Conclusion: This study highlights the urgent needs to address structural racism, labor market discrimination, and residential segregation that diminish the impact of education on living conditions for Black and Latino mothers, compared to non-Latino White mothers, even for those living under poverty. Policymakers and practitioners should develop targeted interventions to reduce racial and ethnic disparities in access to paid and unpaid maternity leave and other critical resources, particularly for new mothers living in poverty. Addressing these inequities is essential for improving maternal and newborn health outcomes and promoting social justice.
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Open Access November 15, 2024

Education Does Not Equally Increase Financial Well-being for All

Abstract Background: Financial well-being is a key domain of overall well-being, encompassing an individual's ability to meet financial obligations, secure their financial future, and maintain a sense of financial freedom. Education is often viewed as a critical pathway to enhancing financial well-being. However, the returns of education on financial well-being are not uniform across racial, ethnic, [...] Read more.
Background: Financial well-being is a key domain of overall well-being, encompassing an individual's ability to meet financial obligations, secure their financial future, and maintain a sense of financial freedom. Education is often viewed as a critical pathway to enhancing financial well-being. However, the returns of education on financial well-being are not uniform across racial, ethnic, and nativity groups. The theory of Minorities’ Diminished Returns (MDRs) suggests that the positive effects of education on outcomes such as income and financial security are weaker for marginalized groups, including Black individuals, Latinos, and immigrants. Objective: This study examines the diminished returns of education on financial well-being among Black, Latino, and immigrant populations in the United States. We aim to investigate how structural inequalities contribute to weaker financial returns on education for these groups compared to their White and native-born counterparts. Methods: We utilized data from the Understanding America Study (UAS 2014) to conduct a cross-sectional analysis of adult respondents. The study assessed financial well-being outcomes (e.g., income, savings, and financial security) and their association with educational attainment across racial, ethnic, and nativity groups. Regression models were employed to test for interaction effects between education and race/ethnicity/nativity, adjusting for sociodemographic factors such as age, gender, employment, and family structure. Results: Our analysis included 8,121 individuals. The mean age of the respondents was 48 years (SD = 16). High education was associated with higher financial well-being (B = 1.284, 95% CI: 1.157, 1.410). The interaction terms between education and immigrant status (B = -0.507, 95% CI: -0.930, -0.084), race (Black) (B = -0.770, 95% CI: -1.208, -0.331), and ethnicity (Hispanic) (B = -0.589, 95% CI: -0.969, -0.210) were all significant, suggesting that immigrant, Black, and Hispanic individuals experience diminished returns on education in terms of financial well-being, relative to US-born non-Hispanic White individuals. The significant negative interactions between education and minority statuses (Black, Hispanic, and immigrant) indicate that while education generally improves financial well-being, the magnitude of this improvement is substantially smaller for these marginalized groups. Conclusion: Understanding how education translates to financial well-being across different racial, ethnic, and nativity groups is critical for addressing persistent financial disparities.
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Open Access August 05, 2023

Structural controls mineralization in strike-slip fault terminals, case study: Kaybarkuh region in East of Iran

Abstract In this study, we have investigated the status of faults in terms of precession and subsequence, and their relationship with vein mineralization in Kaybarkuh intrusive body in East of Iran. At least, three generations of faults are evidenced in Dasht-e-Bayaz (DB) fault terminal. During formation of faults, the stress orientation in the region has changed at least once probably due to DB fault [...] Read more.
In this study, we have investigated the status of faults in terms of precession and subsequence, and their relationship with vein mineralization in Kaybarkuh intrusive body in East of Iran. At least, three generations of faults are evidenced in Dasht-e-Bayaz (DB) fault terminal. During formation of faults, the stress orientation in the region has changed at least once probably due to DB fault evolution. Mineralization, especially gold and copper, is formed along the third-generation faults and sometimes on the fault surfaces. It can be predicted that mineralization also happened in the tensioned area of Kal-Shur covered by salt playa and Quaternary sediments, which requires subsurface and geophysics studies.
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Open Access July 06, 2023

Health condition of palm trees of Mexico City, with an emphasis on “crowns”

Abstract The government of Mexico City carried out the introduction of palm trees in the 50s to increase the visual appearance of the main avenues. As a result of introduction of these exotic species, phytosanitary problems appeared. Currently there is scarce information on how to evaluate the health of these majestic monocots, in this sense, it is necessary to implement assessment scales to determine the [...] Read more.
The government of Mexico City carried out the introduction of palm trees in the 50s to increase the visual appearance of the main avenues. As a result of introduction of these exotic species, phytosanitary problems appeared. Currently there is scarce information on how to evaluate the health of these majestic monocots, in this sense, it is necessary to implement assessment scales to determine the health condition of the most frequently found species to advance on their care and management. The present study had the following objectives: 1) To determine the current state of health of palm trees by means of a scale of visual evaluation of the crown; 2) To know the diversity and structural characteristics of palm trees and 3) To determine the influence of composite variables on the ecosystem services such as the amount of shade provided. Health of palm trees were evaluated two times (dry and rainy seasons in 2022) on 35 transects of 200 m length. An imaginary circle divided into twelfths was overlapped on palm tree “crowns”, and through it, two absolute variables, Live Crown Ratio (LCR) and Crown Quality (CQ) were evaluated. Composite variables were also calculated. The 12/12 health scale adapted in the present study was useful. Four health categories were obtained for the Live crown ratio (LCR): 7.62% of the palm trees were in critical condition, 7.80% were in intermediate condition, 80.36% were in normal condition, and 4.20% were in excellent condition. Meanwhile, for crown quality (CQ), the percentages were 13.50%, 20.00%, 56.96% and 0.43%, respectively. The total height and “crown” diameter showed a positive correlation with the volume composite variables. The shadow area projected as an important ecosystem service increased as the health of the palm trees improved. This is the first study on palm trees health assessment in Mexico City.
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Open Access March 03, 2022

New Parameter for Characterization of Dispersed Systems

Abstract A new parameter was proposed, with the help of which a specific disperse system was characterized. In addition, a regularity was found showing the relationship between the structural characteristics of structural units (particle size distribution, standard deviation, intensity and average diameter). Various highly dispersed systems have been investigated, including polystyrene latex, Sucrose and [...] Read more.
A new parameter was proposed, with the help of which a specific disperse system was characterized. In addition, a regularity was found showing the relationship between the structural characteristics of structural units (particle size distribution, standard deviation, intensity and average diameter). Various highly dispersed systems have been investigated, including polystyrene latex, Sucrose and latex.
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Open Access February 13, 2026

Influence of Religious Literacy and Multicultural Teaching Competence on Religious and Moral Education Teachers’ Self-Efficacy: Empirical Evidence from Public Basic Schools in the Kumasi Metropolis

Abstract The focus of this study was to determine the influence of religious literacy and multicultural teaching competence on the teaching self-efficacy of Religious and Moral Education (RME) teachers in public basic schools within the Kumasi Metropolis. The research employed a cross-sectional survey design with a sample of 308 RME teachers selected through the stratified sampling technique from 165 basic [...] Read more.
The focus of this study was to determine the influence of religious literacy and multicultural teaching competence on the teaching self-efficacy of Religious and Moral Education (RME) teachers in public basic schools within the Kumasi Metropolis. The research employed a cross-sectional survey design with a sample of 308 RME teachers selected through the stratified sampling technique from 165 basic schools across 14 circuits. Data were collected using questionnaires and analysed using Partial Least Squares Structural Equation Modelling (PLS-SEM). The findings revealed that religious literacy significantly and positively influenced teachers’ self-efficacy (β = 0.487, p < 0.05), accounting for 23.7% of the variance. Similarly, multicultural teaching competence demonstrated a strong positive effect on teaching self-efficacy (β = 0.711, p < 0.05), explaining 50.6% of the variance. Finally, the study found that religious literacy and multicultural teaching competence together contributed 52.2% to RME teachers' teaching self-efficacy (SD = 0.692, p < 0.05, R² = 0.522). The study recommended that the Ghana Education Service (GES) and the National Council for Curriculum and Assessment (NaCCA) should design and mandate regular in-service training programmes focused specifically on religious literacy for RME teachers. Also, it was recommended that pre-service and in-service training should emphasise awareness of personal biases, deep knowledge of learners’ cultural and religious backgrounds, and practical skills for culturally responsive pedagogy.
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Open Access November 28, 2025

Determinants of the Carotid Tortuosity Index: Evidence from Digital Subtraction Angiography

Abstract Introduction: Stroke remains one of the leading causes of death and disability worldwide, with ischemic stroke accounting for most cases. Structural vascular factors such as carotid artery tortuosity have gained attention as potential markers of vascular aging and cerebrovascular risk. The carotid tortuosity index (CTI), defined as the ratio of actual vessel length to the straight-line [...] Read more.
Introduction: Stroke remains one of the leading causes of death and disability worldwide, with ischemic stroke accounting for most cases. Structural vascular factors such as carotid artery tortuosity have gained attention as potential markers of vascular aging and cerebrovascular risk. The carotid tortuosity index (CTI), defined as the ratio of actual vessel length to the straight-line distance between two fixed points, provides a quantitative measure of arterial curvature. A CTI value of ≥1.2 indicates pathological tortuosity. Although noninvasive modalities such as CTA and MRA are frequently used, digital subtraction angiography (DSA) remains the gold standard for evaluating vessel geometry due to its higher spatial precision. This study aimed to determine the association of age, sex, and hypertension with CTI measured by DSA. Methods: A cross-sectional study was conducted from November to December 2025 at the Neurointervention Clinic, RS Pelni Jakarta, Indonesia, involving 61 adult patients who underwent carotid DSA. CTI was measured bilaterally using digital imaging software and classified as <1.2 (non-tortuous) or ≥1.2 (tortuous). Clinical data, including age, sex, and hypertension status, were collected from medical records and analyzed using bivariate tests. Results: Older age (≥65 years), female sex, and hypertension were significantly associated with higher CTI values on both carotid sides. Tortuosity was more common among hypertensive patients and elderly females, indicating the influence of vascular remodeling and chronic hemodynamic stress. Conclusion: Carotid tortuosity increases with age, hypertension, and female sex. DSA-based CTI measurement provides a reliable and precise approach for evaluating vascular changes associated with cerebrovascular risk.
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