65 research outputs found
ASSESSMENT OF DOSE INTAKE OF TOXIC ELEMENTS IN GROUNDWATER SAMPLES FROM ABUJA, NORTH CENTRAL NIGERIA
This study measured the concentrations of toxic carcinogenic and non-carcinogenic elements present
in groundwater using Inductively Coupled-Plasma Mass Spectrometry (ICP-MS). The concentration
values obtained were used to calculate the life average daily dose (LADD) exposure of the people
whom rely on groundwater for consumption in Abuja, Nigeria. The highest LADD for the
carcinogenic toxic element chromium (Cr) was 2.7 x 10-5 μg kg‒1 day‒1, whereas it was 3.3 x 10-4 μg
kg‒1 day‒1 for the non-carcinogenic toxic element lead (Pb), identified in water samples collected by
the Water Board. These LADD magnitudes of 10-5 and 10-4 for both carcinogenic and noncarcinogenic
toxic elements in groundwater are far below the International Reference Dose according
to the United States Environmental Protection Agency (USEPA) in 2008, which has a value of 10-1.
The low magnitudes found in water samples may not pose significant health risks to the local
population. The relevant authorities should, therefore, continue to monitor the impact of human
activities on metal pollution in this area and take effective measures to control contamination of the
public water suppl
Characterization of Puberty in an Australian Population-Based Cohort Study
Purpose:
Current knowledge of the characteristics of puberty beyond age at menarche and thelarche is limited, particularly within population-based cohorts. Secular trends and concerns of the health effects of early puberty reinforce the value of contemporary studies characterizing the timing, tempo, duration, and synchronicity of puberty.
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Methods:
The Childhood to Adolescence Transition Study is a unique Australian cohort of individuals followed annually from late childhood to late adolescence, with up to eight assessments of pubertal stage from 9 to 19 years of age (N = 1,183; 636 females). At each assessment, females reported their Tanner Stage of breast and pubic hair development, while males reported on genital/pubic hair development. Nonlinear mixed-effects models characterized pubertal trajectories and were used to derive each individual’s estimates of timing, tempo, and synchronicity. Parametric survival models were used to estimate the overall duration of puberty.
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Results:
Timing of mid-puberty (Tanner Stage 3) ranged from 12.5 to 13.5 years, with females developing approximately 6 months before males. Pubertal tempo (at mid-puberty) was similar across sex (between half and one Tanner Stage per year), but the overall duration of puberty was slightly shorter in males. Most females exhibited asynchronous changes of breast and pubic hair development.
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Discussion:
Estimates of pubertal timing and tempo are consistent with reports of cohorts from two or more decades ago, suggesting stabilization of certain pubertal characteristics in predominantly White populations. However, our understanding of the duration of puberty and individual differences in pubertal characteristics (e.g., synchronicity of physical changes) remains limited
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae)
Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species—drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit conservation and restocking efforts and help fine-tune mariculture techniques. Understanding the repertoire of giant clam behaviours will also facilitate the prediction of threshold levels for sustainable exploitation as well as recovery rates of depleted clam populations
Argumentative writing behavior of graduate EFL learners
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This study analyzed the argumentative writing behavior of Iranian graduate learners of English as Foreign Language in their English essays. Further, the correlations between the use of argument elements and overall writing quality as well as soundness of produced arguments were investigated. To this end, 150 essays were analyzed. The sample essays were found to be predominantly deductive in terms of rhetorical pattern. Moreover, they mainly utilized ‘data’ and ‘claim’ most frequently with secondary elements of argument (i.e., counterargument claim, counterargument data, rebuttal claim, and rebuttal data) as the least produced elements. Overall writing quality co-varied significantly positively with the uses of claims, data, counterargument claims, counterargument data, rebuttal claims, and rebuttal data. Essays rated high in terms of overall writing quality were further rated for soundness and relevance of the arguments. The results demonstrate that even for advanced language learners good surface structure cannot necessarily guarantee well thought-out logical structure. The pedagogical implications for writing instruction and research are discussed
The effect of service quality, satisfaction and loyalty toward customer retention in the telecommunication industry
Telecommunication industry becomes more competitive, and mobile service providers are facing challenges in maintaining their customer. As a customer plays a vital role in business growth, a company must retain their customer. Thus, the purpose of this research is to examine the effect of service quality, satisfaction and loyalty towards customer retention a telecommunication industry in Malaysia. Data has been collected using a survey questionnaire and analyzed using SPSS and Smart-PLS. Six of the hypotheses were supported. Customer satisfaction has been found to have a significant relationship with customer loyalty. Service quality, which was measured using the network, customer service, and pricing structure, has been found to have a significant relationship with customer satisfaction. Research implications and recommendations are further discussed
Feasible transition path generation for EFSM-based system testing
This paper presents a feasible transition path (FTP) generation approach for testing extended finite state machines (EFSM). The major problem faced by EFSM-based testing is the existence of the infeasible paths due to conflict of the context variable with the enable conditions in the transition path. In order to avoid infeasible path generation, this paper proposed an approach that uses the modified breadth first search with conflict checker to generate a set of minimum FTP for each transition. An EFSM executable model is developed for algorithm modeling and verification as well as performance evaluation. Experimental results conducted on two EFSM models showed that the proposed approach is able to generate feasible transition path with at least 18% path length reduction
Removal of Fe (II) in groundwater using rice husk-sourced biosorbent in continuous column adsorption
Integrated tidal marine turbine for power generation with coastal erosion breakwater
Malaysia experiences predictable tides year round. Areas with the greatest potential are Terengganu and Sarawak waters with average annual power generation between 2.8kW/m to 8.6kW/m. This condition gives excellent opportunity to explore power generation using tidal energy converters by utilization of stand-alone marine facilities such as breakwater with the tidal stream energy. The tidal energy converter is a device that converts the energy in a flow of fluid into mechanical energy by passing the stream through a system of fixed and moving fan like blades. The power output is dependent on its design characteristics, which covers the turbine specification and the met-ocean environmental condition. Hence, this paper focused on the conceptual design of the integrated marine turbine mounted on wave breakwater known as WABCORE. The proposed marine turbine was installed in the breakwater and the generated energy was estimated based on the performance analysis through Finite Element Analysis (FEA) and ANSYS Fluent Computational Fluid Dynamics (Fluent CFD) simulations. It was found that a maximum power output of 30 Watts could be generated by horizontal-axis axial-flow marine turbine with excellent venturi-effect of piping design that provided significant contribution on power generation
Central insulin administration improves whole-body insulin sensitivity via hypothalamus and parasympathetic outputs in men.
Animal studies suggest that insulin action in the brain is involved in the regulation of peripheral insulin sensitivity. Whether this holds true in humans is unknown. Using intranasal application of insulin to the human brain, we studied impacts of brain insulin action on whole-body insulin sensitivity and mechanisms involved in this process.Insulin sensitivity was assessed by hyperinsulinemic euglycemic glucose clamp, before and after intranasal application of insulin and placebo in randomized order in lean and obese men. After insulin spray application in lean, higher glucose infusion rate was necessary to maintain euglycemia compared to placebo. Accordingly, clamp-derived insulin sensitivity index improved after insulin spray. In obese subjects, this insulin sensitizing effect could not be detected.Change in the high frequency band of heart rate variability, an estimate of parasympathetic output, correlated positively with change in whole-body insulin sensitivity after intranasal insulin. Improvement in whole-body insulin sensitivity correlated with the change in hypothalamic activity as assessed by functional magnetic resonance imaging.In summary, intranasal insulin improves peripheral insulin sensitivity in lean but not in obese men. Furthermore, brain-derived peripheral insulin sensitization is associated with hypothalamic activity and parasympathetic outputs. Thus, our findings provide novel insights into the regulation of insulin sensitivity and the pathogenesis of insulin resistance in humans
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