Spatiotemporal dynamics of attention in visual neglect: a case study

Patients with visual neglect are often unaware of contralesional visual stimuli. Recent studies have demonstrated non-spatial as well as spatial deficits in allocating attention in neglect patients. We examined the spatiotemporal dynamics of directing attention in a patient with neglect for visual objects appearing in the left side of space by using a version of the attentional blink paradigm. presenting two visual stimuli in succession. The first target (T1) was presented at fixation. The location of the second target (T2) and time between the two targets was varied. When T2 appeared to the left, the patient required more time between targets to identify both accurately, compared to when T2 appeared at fixation or to the right. Our findings demonstrate a spatial and temporal gradient of attention. The results are discussed with respect to current models of visual processing in visual neglect.     

Exposure Assessment to Trichloroethylene and Perchloroethylene for Workers in the Dry Cleaning Industry

Perchloroethylene and trichloroethylene are two particular organochloro compounds, are often used for dry-cleaning. In the present study the excretion of urinary Perchloroethylene and trichloroethylene were evaluated as biomarkers of exposure to these compounds. The mean value of Perchloroethylene in breathing zone and the total Perchloroethylene uptake during the work shift of the three groups of dry-cleaning workers according to the capacity of the dry-cleaning machine (8, 12 and 18 kg) were 31.04, 50.87 and 120.99 mg m⁻³ and 11.46, 22.6 and 41.6 μg L⁻¹, respectively, which were significantly greater than the occupationally nonexposed groups. A good correlation (r = 0.907) between the mean values of Perchloroethylene in breathing zone and the urinary concentrations was observed.     

Framework for assessing governance of the health system in developing countries: gateway to good governance

Governance is thought to be a key determinant of economic growth, social advancement and overall development, as well as for the attainment of the MDGs in low- and middle-income countries. Governance of the health system is the least well-understood aspect of health systems. A framework for assessing health system governance (HSG) at national and sub-national levels is presented, which has been applied in countries of the Eastern Mediterranean. In developing the HSG framework key issues considered included the role of the state vs. the market; role of the ministries of health vs. other state ministries; role of actors in governance; static vs. dynamic health systems; and health reform vs. human rights-based approach to health. Four existing frameworks were considered: World Health Organization's (WHO) domains of stewardship; Pan American Health Organization's (PAHO) essential public health functions; World Bank's six basic aspects of governance; and United Nations Development Programme (UNDP) principles of good governance. The proposed HSG assessment framework includes the following 10 principles-strategic vision, participation and consensus orientation, rule of law, transparency, responsiveness, equity and inclusiveness, effectiveness and efficiency, accountability, intelligence and information, and ethics. The framework permits 'diagnoses of the ills' in HSG at the policy and operational levels and points to interventions for its improvement. In the case of Pakistan, where the framework was applied, a positive aspect was the growing participation and consensus orientation among stakeholders, while weaknesses were identified in relation to strategic vision, accountability, transparency, effectiveness and efficiency and rule of law. In using the HSG framework it needs to be recognized that the principles are value driven and not normative and are to be seen in the social and political context; and the framework relies on a qualitative approach and does not follow a scoring or ranking system. It does not directly address aid effectiveness but provides insight on the ability to utilize external resources and has the ability to include the effect of global health governance on national HSG as the subject itself gets better crystallized. The improved performance of the ministries of health and state health departments is at the heart of this framework. The framework helps raise the level of awareness among policymakers of the importance of HSG. The road to good governance in health is long and uneven. Assessing HSG is only the first step; the challenge that remains is to carry out effective governance in vastly different institutional contexts.     

Sensitivity of Crosswise Model to Simplistic Selection of Nonsensitive Questions: An Application to Estimate Substance Use,Alcohol Consumption and Extramarital Sex Among Iranian College Students

Background: Nonrandomized response (NRR) models are a new generation of surveys for sensitive issues. This study aims to evaluate the validity of estimates from the crosswise model (as one of the efficient models) through employing different response probabilities of nonsensitive questions. Methods: This cross-sectional study was conducted during October and November 2015 among 1777 students of Tabriz University of Medical Sciences. Estimates of monthly alcohol consumption, and at least one instance of illicit drug use and extramarital sex over the last year were determined using direct questioning (DQ) and the Crosswise model (CM). In the last model, the probability of positive response to the nonsensitive questions was determined by using five different methods: uniform distribution (I), Benford’s law (II), and estimations based on data from three other studies (III, IV, V). Results: Crosswise estimates of sensitive behaviors with different probabilities of a positive response to nonsensitive questions differed significantly. For example, estimates of history of using illegal opioids at least once in the last year among men varied significantly from 5.0% to 16.1% with different crosswise models based on the probability of being born in Spring using method I (0.250), III (0.287), IV (0.248), and V (0.310). The model based on Benford’s law (II) was applied to estimate alcohol and cannabis consumption, and its estimates showed significant discrepancy with results of crosswise models I and V. Conclusion: Estimates from crosswise model is highly sensitive to the response probability of nonsensitive questions. It seems that if this question is not selected carefully, the mentioned models will provide overestimates or underestimates, and the more-is-better hypothesis is not always valid. To achieve valid estimates, the exact probability of a positive response to the nonsensitive question must be known for the studied population.     

Natural and anthropogenic radioactivity levels and the associated radiation hazard in the soil of Oodalia Tea Estate in the hilly region of Fatickchari in Chittagong,Bangladesh

Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring ²³⁸U and ²³²Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg⁻¹ and 36 ± 11 to 72 ± 11 Bq kg⁻¹, respectively. The activity concentration of ⁴⁰K ranged from 201 ± 78 to 672 ± 81 Bq kg⁻¹, and the highest activity of fallout ¹³⁷Cs observed was 10 ± 1 Bq kg⁻¹. The average activity concentration observed for ²³⁸U was 39 ± 8 Bq kg⁻¹, for ²³²Th was 57 ± 11 Bq kg⁻¹, for ⁴⁰K was 384 ± 79 Bq kg⁻¹ and for ¹³⁷Cs was 5 ± 0.5 Bq kg⁻¹. The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil.     

Spatial remapping of the visual world across saccades

Recent research has identified neurons in the visual system that remap their receptive fields before a saccade. The activity of these neurons may signal a prediction of postsaccadic visual input, derived from an efference copy of saccadic motor output. Such a prediction is often thought to underlie our perception of a stable visual world, by compensating for the shifts in retinal image that accompany each eye movement. Here we review the evidence, and conclude that prediction does not in fact play a significant role in maintaining visual stability. Instead, we consider a novel perspective in which the primary function of spatial remapping is to support three key nonperceptual processes: action control, sensorimotor adaptation and spatial memory.     

131I activity for remnant ablation in patients with differentiated thyroid cancer: A systematic review

CONTEXT: Radioiodine ablation of the thyroid remnant after thyroidectomy is commonly performed in the management of patients with differentiated thyroid cancer. Although many centers administer an activity of 100 mCi, there is uncertainty over using a lower activity. OBJECTIVE: A systematic review of the published literature was used to compare the success rates of remnant ablation using approximately 30 mCi with approximately 100 mCi (1.1 vs. 3.7 GBq). DATA SOURCES: Data were obtained from MEDLINE and EMBASE for the years 1966 to March 2006. STUDY SELECTION: All studies that reported rates of successful ablation associated with approximately 30 or approximately 100 mCi of radioiodine were reviewed. DATA EXTRACTION: Studies were based on reviews of patient case notes (n = 41), prospective cohorts (n = 12), and randomized trials (n = 6). We obtained the success of thyroid remnant ablation according to different administered activities of radioiodine. Where a study reported on two or more activities, the risk ratio of having a successful ablation (approximately 30 vs. approximately 100 mCi) was calculated and combined in a meta-analysis. DATA SYNTHESIS: Observational studies confirmed the high ablation success rate ( approximately 80%) using approximately 100 mCi, although 22% of studies reported a rate of 90% or greater. The pooled ablation success rate in these studies was 10% lower using 30 mCi compared with 100 mCi (95% confidence interval, 3-17%; P = 0.01). The meta-analysis of the randomized trials produced equivocal results. For example, the rate of successful ablation in patients given 30 mCi was 8% lower compared with 100 mCi (95% confidence interval, 29% lower or up to 20% greater, P = 0.58), consistent with there being no difference or that 30 mCi is much less effective. CONCLUSIONS: From the published data, it is not possible to reliably determine whether ablation success rates using 30 mCi are similar to using 100 mCi. Large randomized trials are needed to resolve the issue and guide clinical practice.