Prevalence and ergonomic risk factors of work-related musculoskeletal injuries amongst underground mine workers in Zambia

Work-related musculoskeletal injuries (WMSIs) are common in both developed and third world countries. Most researchers agree that exposure to ergonomic risk factors is a major contributor to these injuries. Objective: The aim of this study was to determine the prevalence of and ergonomic risk factors associated with WMSIs amongst underground mine workers in Kitwe, Zambia. Methods: A cross-sectional quantitative study was conducted using a sample size of 500 workers. A stratified random sampling method according to mining work activity type was used to obtain the sample. Data was collected by means of a structured questionnaire, and the Statistical Package for Social Sciences (SPSS) was used to analyze data using descriptive and inferential statistical methods. Results were significant at 5%. Results: A response rate of 40.4% (202) was obtained. The 12-month prevalence of WMSIs was 42.6%. The mean age of the workers was 40.31 years (SD +/− 8.57 years). Electricians and mechanics reported the highest injury frequencies. The back was the most affected body part. Ergonomic risk factors consistently reported by workers included poor postures and heavy lifting. There were significant (p=0.020) associations between working with the back bent and sustaining a back injury. Significant (p=0.049) associations were also found between injuries of the wrists/hands and grasping an unsupported object(s). Conclusions: This study revealed significant associations between WMSIs and ergonomic risk factors like working with the back bent and grasping object.Web of Scienc

Daily Patterns of River Herring (\u3cem\u3eAlosa\u3c/em\u3e spp.) Spawning Migrations: Environmental Drivers and Variation among Coastal Streams in Massachusetts

The timing of life history events in many plants and animals depends on the seasonal fluctuations of specific environmental conditions. Climate change is altering environmental regimes and disrupting natural cycles and patterns across communities. Anadromous fishes that migrate between marine and freshwater habitats to spawn are particularly sensitive to shifting environmental conditions and thus are vulnerable to the effects of climate change. However, for many anadromous fish species the specific environmental mechanisms driving migration and spawning patterns are not well understood. In this study, we investigated the upstream spawning migrations of river herring Alosa spp. in 12 coastal Massachusetts streams. By analyzing long-term data sets (8–28 years) of daily fish counts, we determined the local influence of environmental factors on daily migration patterns and compared seasonal run dynamics and environmental regimes among streams. Our results suggest that water temperature was the most consistent predictor of both daily river herring presence–absence and abundance during migration. We found inconsistent effects of streamflow and lunar phase, likely due to the anthropogenic manipulation of flow and connectivity in different systems. Geographic patterns in run dynamics and thermal regimes suggest that the more northerly runs in this region are relatively vulnerable to climate change due to migration occurring later in the spring season, at warmer water temperatures that approach thermal maxima, and during a narrower temporal window compared to southern runs. The phenology of river herring and their reliance on seasonal temperature patterns indicate that populations of these species may benefit from management practices that reduce within-stream anthropogenic water temperature manipulations and maintain coolwater thermal refugia

Pharmacokinetic aspects of retinal drug delivery

Drug delivery to the posterior eye segment is an important challenge in ophthalmology, because many diseases affect the retina and choroid leading to impaired vision or blindness. Currently, intravitreal injections are the method of choice to administer drugs to the retina, but this approach is applicable only in selected cases (e.g. anti-VEGF antibodies and soluble receptors). There are two basic approaches that can be adopted to improve retinal drug delivery: prolonged and/or retina targeted delivery of intravitreal drugs and use of other routes of drug administration, such as periocular, suprachoroidal, sub-retinal, systemic, or topical. Properties of the administration route, drug and delivery system determine the efficacy and safety of these approaches. Pharmacokinetic and pharmacodynamic factors determine the required dosing rates and doses that are needed for drug action. In addition, tolerability factors limit the use of many materials in ocular drug delivery. This review article provides a critical discussion of retinal drug delivery, particularly from the pharmacokinetic point of view. This article does not include an extensive review of drug delivery technologies, because they have already been reviewed several times recently. Instead, we aim to provide a systematic and quantitative view on the pharmacokinetic factors in drug delivery to the posterior eye segment. This review is based on the literature and unpublished data from the authors' laboratory.Peer reviewe

Dynamic Response of Pile Reinforced Soils and Piled Foundations

International audienc

User Fairness in Wireless Powered Communication Networks with Non-Orthogonal Multiple Access

This letter investigates user fairness in wireless powered communication networks (WPCNs) with non-orthogonal multiple access (NOMA) with the aim of maximizing the equal individual data rates. Initially, it is proposed the bisection method to obtain the optimal power allocation coefficients. Then, Lagrange dual-decomposition is considered for evaluating the optimal time-splitting ratio. Next, Newton's method combined with the sub-gradient method are employed to achieve the optimal solution. In addition, two sub-optimal solutions that provide a good balance between performance and complexity are proposed. Lastly, simulation results are presented to evaluate the performance of the proposed solutions. © 2012 IEEE

CHARACTERIZATION OF THE TOXICOLOGICAL EFFECTS OF AMINOCARB ON RATS: HEMATOLOGICAL, BIOCHEMICAL, AND HISTOLOGICAL ANALYSES

Aminocarb is a widely applied carbamate insecticide with action of controlling pests such as Lepidoptera and Coleoptera. In this study, subchronic effects on Wistar rats were investigated using hematological, biochemical, and histological techniques. Rats were exposed orally at sublethal levels of 10, 20, or 40 mg/kg body weight (groups A, B, and C, respectively) for 14 d. Hematological results revealed no statistical differences after 1 d of exposure but significant reduction in white blood cells detected after 7 d of exposure in group C, as well as, in all treated groups after 14 d of exposure. Biochemical data showed a decrease of acetylcholinesterase activity in all groups after 1 d of exposure with a return to normal after 7 and 14 d. Significant increase in alkaline phosphatase activity of rats exposed to aminocarb was noted after 7 d of treatment. The levels of triglycerides were also significantly decreased. The present investigation also showed a significant increase in content of serum urea and creatinine in animals from group A (14 d), and from groups B and C (7 and 14 d). Histological results demonstrated hemorrhagic focus on hepatic and renal parenchyma in all exposed groups. Taken together, the attained results were dose dependent and indicated adverse effects of aminocarb on hepatic and renal functions, as well as on immune responsiveness at sublethal tested doses