Suchergebnisse

Mobile phones, particularly smartphones, have become an indispensable part of our daily lives. Technological advancements and the availability of high-speed internet services have culminated in an enormous rise in the number of mobile phone users. Nowadays, as a result of constant advancements in mobile phone technology and other factors, a portion of consumers use more than one mobile phone. On the other hand, the actual lifespan of a mobile phone has reached nearly 4 years. As a result, mobile phone waste as a component of electronic waste has increased significantly over the last decade. From an environmental point of view, various carcinogenic chemical components may be released from mobile phones during the informal recycling process, drastically polluting our environment. According to our survey, while the majority of educated mobile phone users in Kolkata are aware of the adverse effects of electronic waste (e-waste), they typically choose less expensive and easier disposal solutions since they are not concerned about the recycling of mobile phones or e-waste. This study primarily highlighted mobile phone disposal behaviours in Kolkata, India. After reviewing the results of our questionnaire, we noticed numerous actual problems with customers' disposal patterns for their obsolete mobile phones. In this article, we attempt to depict the current problem of e-waste generated from mobile phones in Kolkata.

Con el objetivo de identificar la relación entre el desempeño docente en las plataformas virtuales y la satisfacción de clases online en estudiantes universitarios, se sometió a estudio a 326 estudiantes peruanos a quienes se les aplicó dos encuestas: E-teach performance in virtual environments y satisfacción de clases online, encontrando en su aplicación que estas dos variables se relacionan de manera directa y significativa con un R Spearman 0,845; además, dentro del análisis se demuestra que la percepción del desempeño docente por parte de los alumnos genera satisfacción de clases online.

Efavirenz (EFV) is a nonnucleoside reverse transcriptase inhibitor approved worldwide for the treatment of HIV in adults and children over 3 years of age or weighing over 10 kg. Only recently EFV was approved in children over 3 months and weighing at least 3.5 kg in the United States and the European Union. The objective of this analysis was to support the selection of an appropriate dose for this younger pediatric population and to explore the impact of CYP2B6 genetic polymorphisms on EFV systemic exposures. A population pharmacokinetic (PPK) model was developed using data from three studies in HIV-1-infected pediatric subjects (n = 168) and one study in healthy adults (n = 24). The EFV concentration-time profile was best described by a two-compartment model with first-order absorption and elimination. Body weight was identified as a significant predictor of efavirenz apparent clearance (CL), oral central volume of distribution (VC), and absorption rate constant (Ka). The typical values of efavirenz apparent CL, VC, oral peripheral volume of distribution (VP), and Ka for a reference pediatric patient were 4.8 liters/h (4.5 to 5.1 liters/h), 84.9 liters (76.8 to 93.0 liters), 287 liters (252.6 to 321.4 liters), and 0.414 h−1 (0.375 to 0.453 h−1), respectively. The final model was used to simulate steady-state efavirenz concentrations in pediatric patients weighing <10 kg to identify EFV doses that produce comparable exposure to adult and pediatric patients weighing ≥10 kg. Results suggest that administration of EFV doses of 100 mg once daily (QD) to children weighing ≥3.5 to <5 kg, 150 mg QD to children weighing ≥5 to <7.5 kg, and 200 mg QD to children weighing ≥7.5 to <10 kg produce exposures within the target range. Further evaluation of the impact of CYP2B6 polymorphisms on EFV PK showed that the identification of CYP2B6 genetic status is not predictive of EFV exposure and thus not informative to guide pediatric dosing regimens.

This book describes a pathway for sustainable phosphorus management via the Global Transdisciplinary Processes for Sustainable Phosphorus Management project (Global TraPs). Global TraPs is a multi-stakeholder forum in which scientists from a variety of disciplines join with key actors in practice to jointly identify critical questions and to articulate what new knowledge, technologies and policy processes are needed to ensure that future phosphorus use is sustainable, improves food security and environmental quality and provides benefits for the poor. The book offers insight into economic scarcity and identifies options to improve efficiency and reduce environmental impacts of anthropogenic phosphorus flows at all stages of the supply-demand chain. The opening chapter provides a comprehensive survey describing "what is wrong with the current anthropogenically driven phosphorus cycle, based on a material flow analysis". Five chapters address such challenges of sustainable phosphorus as understanding the dynamics of reserves and elaborating when economic scarcity may become physical scarcity, the multiple costs of mining and the challenge of innovation in fertilizer products and production. Chapters on use and on dissipation and recycling establish that phosphorus has a dissipative structure and shows low use efficiency and high losses along the entire length of its value chain, and go on to identify constraints and options for closing the anthropogenic phosphorus loop. A concluding chapter on trade and finance discusses the causes of price volatility of phosphorus products. Fifty key stakeholders from industry and scientists from different disciplines have contributed to this volume, writing full chapters and related spotlights on critical points. Their wide-ranging expertise helps to establish a transdisciplinary perspective as they identify the knowledge and the key stakeholders which must be included in a successful transition from current phosphorus management toward sustainability