303 research outputs found

    Comparisons of urban and rural heat stress conditions in a hot–humid tropical city

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    Background: In recent years the developing world, much of which is located in the tropical countries, has seen dramatic growth of its urban population associated with serious degradation of environmental quality. Climate change is producing major impacts including increasing temperatures in these countries that are considered to be most vulnerable to the impact of climate change due to inadequate public health infrastructure and low income status. However, relevant information and data for informed decision making on human health and comfort are lacking in these countries. Objective: The aim of this paper is to study and compare heat stress conditions in an urban (city centre) and rural (airport) environments in Akure, a medium-sized tropical city in south-western Nigeria during the dry harmattan season (January–March) of 2009. Materials and methods: We analysed heat stress conditions in terms of the mean hourly values of the thermohygrometric index (THI), defined by simultaneous in situ air temperature and relative humidity measurements at both sites. Results: The urban heat island (UHI) exists in Akure as the city centre is warmer than the rural airport throughout the day. However, the maximum UHI intensity occurs at night between 1900 and 2200 hours local time. Hot conditions were predominant at both sites, comfortable conditions were only experienced in the morning and evenings of January at both sites, but the rural area has more pleasant morning and evenings and less of very hot and torrid conditions. January has the lowest frequency of hot and torrid conditions at both sites, while March and February has the highest at the city centre and the airport, respectively. The higher frequencies of high temperatures in the city centre suggest a significant heat stress and health risk in this hot humid environment of Akure. Conclusions: More research is needed to achieve better understanding of the seasonal variation of indoor and outdoor heat stress and factors interacting with it in order to improve the health, safety, and productivity of Akure city dwellers

    The transcription factor GTF2IRD1 regulates the topology and function of photoreceptors by modulating photoreceptor gene expression across the retina

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    The mechanisms that specify photoreceptor cell-fate determination, especially as regards to short-wave-sensitive (S) versus medium-wave-sensitive (M) cone identity, and maintain their nature and function, are not fully understood. Here we report the importance of general transcription factor II-I repeat domain-containing protein 1 (GTF2IRD1) in maintaining M cone cell identity and function as well as rod function. In the mouse, GTF2IRD1 is expressed in cell-fate determined photoreceptors at postnatal day 10. GTF2IRD1 binds to enhancer and promoter regions in the mouse rhodopsin, M- and S-opsin genes, but regulates their expression differentially. Through interaction with the transcription factors CRX and thyroid hormone receptor β 2, it enhances M-opsin expression, whereas it suppresses S-opsin expression; and with CRX and NRL, it enhances rhodopsin expression. In an apparent paradox, although GTF2IRD1 is widely expressed in multiple cell types across the retina, knock-out of GTF2IRD1 alters the retinal expression of only a limited number of annotated genes. Interestingly, however, the null mutation leads to altered topology of cone opsin expression in the retina, with aberrant S-opsin overexpression and M-opsin underexpression in M cones. Gtf2ird1-null mice also demonstrate abnormal M cone and rod electrophysiological responses. These findings suggest an important role for GTF2IRD1 in regulating the level and topology of rod and cone gene expression, and in maintaining normal retinal function

    Invited Editorial: Health as a crucial driver for climate policy

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    Health impacts of climate change and the need to prevent them should be at centre stage of the ongoing debate on climate policies (1). We have specifically prepared this series of papers to be available for the COP151 conference in Copenhagen, to which the world looks to agree on targets and procedures to reduce greenhouse gas (GHG) emissions on the basis of fair burden-sharing between high and low-income countries

    Long-Term Effects of Traffic-Related Air Pollution on Mortality in a Dutch Cohort (NLCS-AIR Study)

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    BACKGROUND: Several studies have found an effect on mortality of between-city contrasts in long-term exposure to air pollution. The effect of within-city contrasts is still poorly understood. OBJECTIVES: We studied the association between long-term exposure to traffic-related air pollution and mortality in a Dutch cohort. METHODS: We used data from an ongoing cohort study on diet and cancer with 120,852 subjects who were followed from 1987 to 1996. Exposure to black smoke (BS), nitrogen dioxide, sulfur dioxide, and particulate matter < or = 2.5 microm (PM(2.5)), as well as various exposure variables related to traffic, were estimated at the home address. We conducted Cox analyses in the full cohort adjusting for age, sex, smoking, and area-level socioeconomic status. RESULTS: Traffic intensity on the nearest road was independently associated with mortality. Relative risks (95% confidence intervals) for a 10-microg/m(3) increase in BS concentrations (difference between 5th and 95th percentile) were 1.05 (1.00-1.11) for natural cause, 1.04 (0.95-1.13) for cardiovascular, 1.22 (0.99-1.50) for respiratory, 1.03 (0.88-1.20) for lung cancer, and 1.04 (0.97-1.12) for mortality other than cardiovascular, respiratory, or lung cancer. Results were similar for NO(2) and PM(2.5), but no associations were found for SO(2). CONCLUSIONS: Traffic-related air pollution and several traffic exposure variables were associated with mortality in the full cohort. Relative risks were generally small. Associations between natural-cause and respiratory mortality were statistically significant for NO(2) and BS. These results add to the evidence that long-term exposure to ambient air pollution is associated with increased mortality

    Use of expert elicitation to assign weights to climate and hydrological models in climate impact studies

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    Various methods are available for assessing uncertainties in climate impact studies. Among such methods, model weighting by expert elicitation is a practical way to provide a weighted ensemble of models for specific real-world impacts. The aim is to decrease the influence of improbable models in the results and easing the decision-making process. In this study both climate and hydrological models are analysed, and the result of a research experiment is presented using model weighting with the participation of six climate model experts and six hydrological model experts. For the experiment, seven climate models are a priori selected from a larger EURO-CORDEX (Coordinated Regional Downscaling Experiment - European Domain) ensemble of climate models, and three different hydrological models are chosen for each of the three European river basins. The model weighting is based on qualitative evaluation by the experts for each of the selected models based on a training material that describes the overall model structure and literature about climate models and the performance of hydrological models for the present period. The expert elicitation process follows a three-stage approach, with two individual rounds of elicitation of probabilities and a final group consensus, where the experts are separated into two different community groups: a climate and a hydrological modeller group. The dialogue reveals that under the conditions of the study, most climate modellers prefer the equal weighting of ensemble members, whereas hydrological-impact modellers in general are more open for assigning weights to different models in a multi-model ensemble, based on model performance and model structure. Climate experts are more open to exclude models, if obviously flawed, than to put weights on selected models in a relatively small ensemble. The study shows that expert elicitation can be an efficient way to assign weights to different hydrological models and thereby reduce the uncertainty in climate impact. However, for the climate model ensemble, comprising seven models, the elicitation in the format of this study could only re-establish a uniform weight between climate models

    Practitioner\u27s Guide to Technology, Pedagogy, and Content Knowledge (TPACK): Rich Media Cases of Teacher Knowledge

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    The goal of the TPACK Practitioners Guide is simple--to offer exemplary cases of technology integration efforts that result in curriculum-based student learning in each of the following nine content areas and grade level contexts: Elementary Science, Elementary Math, Elementary Social Studies, Elementary Reading, Middle School Language Arts, Secondary Science, Secondary Math, Secondary Social Studies, and, Secondary English.https://scholarworks.wm.edu/book/1000/thumbnail.jp
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