How Mentor Support Interacts With Mother and Teacher Support in Predicting Youth Academic Adjustment: An Investigation Among Youth Exposed to Big Brothers Big Sisters of Canada Programs

This study examines three potential contributions (i.e., additive only, hierarchical compensatory, and hierarchical conditional) of mentor support to youth academic adjustment, taking into account interactions with support from mothers and teachers. We derived data from a larger study of the Big Brothers Big Sisters (BBBS) of Canada community mentoring program. The sample included 427 youth (average age 9.8 years; 64% girls, 56% White) who received one-to-one community-based mentoring for at least three months. We assessed perceptions of support from mothers and teachers before the match and assessed perceptions of support from mentors five times throughout the mentoring experience. Hierarchical linear regression analyses showed that mentor support predicted positive changes in youth academic adjustment (i.e., school attitude, academic self-efficacy, assistance seeking, and problem solving) mainly when mentees already reported high support from their mother. This finding clearly supports the conditional model and invites researchers to question the assumption that mentoring constitutes a corrective experience for young people (i.e., the compensatory model). BBBS agencies are strongly encouraged to involve parents in the mentoring process and to view them as experts, assets, and allies in their effort to meet the youth’s needs.     

Histological and Genotoxic Biomarkers in <Emphasis Type="Italic">Prochilodus lacustris</Emphasis> (Pisces,Prochilodontidae) for Environmental Assessment in a Protected Area in the Northeast of Brazil

The quality of aquatic environments all around the world is being altered by different human activities that represent direct threat to the ecological system and the aquatic biota. This study aimed to evaluate the occurrence of histological and genotoxic alterations in Prochilodus lacustris as indicators of anthropic impacts in a lacustrine environment in northeast Brazil. The histological alterations were evaluated using the histological alteration index, and the genotoxic alterations were detected using the micronuclei test, at three sampling stations (S1, S2 and S3). The gills presented lesions with three stages of severity, with mild lesions more frequent in the specimens collected at station S1. Mild hepatic tissue lesions were the most frequent type in both areas. Micronucleus analysis showed that station S3 was the most affected. The biological responses observed indicated that the fish are under influence of environmental changes. It is important to highlight that the organisms collected at station S3 had a more compromised health status.     

Kinetic Modeling of Cr(VI) Reduction by nZVI in Soil: The Influence of Organic Matter and Manganese Oxide

The effect of soil composition on the reduction of hexavalent chromium (Cr(VI)) by zero valent iron nanoparticles was studied. A model was proposed, to investigate both the effect of manganese oxide and the simultaneous effect of manganese dioxide and soil organic matter on the kinetic of Cr(VI) reduction. Fe(0) nanoparticles consumption by the reaction with dissolved oxygen, water and soluble Cr(VI) was taken into account. The model was validated through experimental tests performed on soil samples collected at an industrial polluted site, and on artificially contaminated samples from the same site, in the presence of selected amount of leonardite.     

Assessment of the Remediation Effect of Nano-hydroxyapatite in Exogenous Pb-contaminated Soil Using Toxicity Characteristic Leaching Procedure and Soil Enzyme Activities

This study assessed the level of Pb in soil and five wild plant species (Calotropis procera, Datura alba, Parthenium hysterophorus, Cenchrus ciliaris and Ricinus communis) during all the four seasons. Two busy roads varying in age and traffic volume were selected i.e., Faisalabad–Sargodha road (FSR) and Pindi Bhattian to Lillah (M-2) in the Punjab, Pakistan. Results showed raised levels of Pb in both plants and soil samples along both roads. The range of Pb concentration in plants was 0.08–3.98 and 1.95–4.74 mg kg^??1 for soil. Higher Pb contamination was recorded along FSR road as compared to M-2. Among seasons, the higher Pb concentration was found during summer, probably due to very high temperature. Among all the plants studied, Calotropis procera accumulated the highest level (3.98 mg kg^??1 dry wt.) of Pb; Thus, it can be used as good biomonitor/phytoremediator at Pb contaminated areas.     

Geochemical Assessment of Fluoride Pollution in Groundwater of Tribal Region in India

This study assessed the fluoride (F^?) pollution in groundwater samples (n?=?170) of tribal regions around Bailadila Iron Ore Mines [BIOM] Complex of Dantewada District, India. Weathering of carbonate and silicate clays were important geogenic sources of dissolved ions. A Piper diagram showed a Ca–HCO₃ water type, with positive chloro-alkaline indices illustrating the occurrence of direct base-exchange reactions. The F^? concentrations varied from 0.08 to 1.95 mg L^?1 with a mean value of 0.9?±?0.3 mg L^?1. Only two groundwater samples showed F^? concentrations?>?1.5 mg L^?1, the drinking water guideline established by the World Health Organization (WHO) and Bureau of Indian Standards (BIS). Factor analysis showed high loadings of HCO₃^? and F^?, indicating alkaline conditions, favoring the dissolution of F^? in the groundwater. The K _fluor value is less than 10^?10.6, indicating that the dissociation of fluorite is very slow. As a result, groundwater locations were under-saturated with respect to fluorite.     

Effect of Dibutyl Phthalate on the Tolerance and Lipid Accumulation in the Green Microalgae <Emphasis Type="Italic">Chlorella vulgaris</Emphasis>

Offshore oil exploration creates threats to coastal ecosystems, including increasing urbanization and associated effluent releases. Genotoxicity biomarkers in mussels were determined across a gradient of coastal zone influences of offshore petroleum exploration in southeastern Brazil. Coastal ecosystems such as estuaries, beaches and islands were seasonally monitored for genotoxicity evaluation using the brown mussel Perna perna. The greatest DNA damage (5.2%?±?1.9% tail DNA and 1.5‰? ±?0.8‰ MN) were observed in urban estuaries, while Santana Archipelago showed levels of genotoxicity near zero and is considered a reference site. Mussels from urban and pristine beaches showed intermediate damage levels, but were also influenced by urbanization. Thus, mussel genotoxicity biomarkers greatly indicated the proposed oil exploration and urbanization scenarios that consequently are genetically affecting coastal organisms.     

Validation of a Sulfuric Acid Digestion Method for Inductively Coupled Plasma Mass Spectrometry Quantification of TiO<Subscript>2</Subscript> Nanoparticles

A consistent analytical method incorporating sulfuric acid (H₂SO₄) digestion and ICP-MS quantification has been developed for TiO₂ quantification in biotic and abiotic environmentally relevant matrices. Sample digestion in H₂SO₄ at 110°C provided consistent results without using hydrofluoric acid or microwave digestion. Analysis of seven replicate samples for four matrices on each of 3 days produced Ti recoveries of 97%?±?2.5%, 91?% ±?4.0%, 94%?±?1.8%, and 73?% ±?2.6% (mean?±?standard deviation) from water, fish tissue, periphyton, and sediment, respectively. The method demonstrated consistent performance in analysis of water collected over a 1 month.     

Children’s Doctor Games and Nudity at Danish Childcare Institutions

This article presents the first Danish study of the acceptance of children’s nudity and sexuality at Danish childcare institutions. The study revealed an important cultural shift in the attitude toward children’s nudity and sexual games, the so-called doctor games. Although these were quite accepted at Danish childcare institutions until the beginning of this century, the study showed that new, pervasive regulations had been established to control the child’s body and its sexuality. A new discourse revealed that fear of child sexual abuse, in particular, had influenced views of children’s sexual games and nudity and that, at times, the child itself was viewed as a potential threat to other children. This marks a new development in Denmark, internationally known for its broadmindedness, and this article discusses the background to this cultural shift in the institutions, and possible implications for the children.     

Sexual Activity and Cognitive Decline in Older Adults

This prospective study tested whether sexual activity and emotional closeness during partnered sexual activity relate to cognitive decline (episodic memory performance) in older adulthood. In total, 6016 adults aged 50 and over (2672 men, 3344 women; M age?=?66.0?±?8.8 years) completed an episodic memory task and self-report questions related to health, sexual activity, and emotional closeness. Two years later, participants again completed the episodic memory task. After controlling for demographic and health-related lifestyle factors, more frequent sexual activity and greater emotional closeness during partnered sexual activity were associated with better memory performance. The association between sexual activity and memory performance was stronger among older participants in the sample. Memory performance worsened over 2 years, but change in memory performance was unrelated to sexual activity or emotional closeness during partnered sexual activity. These findings build on experimental research that has found sexual activity enhances episodic memory in non-human animals. Further research using longer timeframes and alternative measures of cognitive decline is recommended.