202 research outputs found

    Overseas Student Teachers’ Reflections on American National Identity: A Longitudinal Study

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    This study draws on narratives submitted between summer 2008 – summer 2018 by 78 student teachers across all grade bands [K-12] and content areas [Language Arts, Social Studies, Science, Mathematics] who completed three months of student teaching in an overseas country through the Consortium for Overseas Student Teaching (COST) during their final undergraduate senior year. All student teachers were in their early 20s. Upon completing their student teaching each student submitted a written reflection in response to the following prompt: Now that you have finished your student teaching abroad experience, what did you learn about yourself as an American? What did you learn about others’ perspectives of what it is that makes someone American? In other words, how do you answer Crevecoeur’s question, “What is an American?” Our findings include 12 major themes categorized into three major categories, i.e. socialization, hegemony and individuation

    Multiple air pollutant exposure and lung cancer in Tehran, Iran

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    Lung cancer is the most rapidly increasing malignancy worldwide with an estimated 2.1 million cancer cases in the latest, 2018 World Health Organization (WHO) report. The objective of this study was to investigate the association of air pollution and lung cancer, in Tehran, Iran. Residential area information of the latest registered lung cancer cases that were diagnosed between 2014 and 2016 (N = 1,850) were inquired from the population-based cancer registry of Tehran. Long-term average exposure to PM10, SO2, NO, NO2, NOX, benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene (BTEX), and BTEX in 22 districts of Tehran were estimated using land use regression models. Latent profile analysis (LPA) was used to generate multi-pollutant exposure profiles. Negative binomial regression analysis was used to examine the association between air pollutants and lung cancer incidence. The districts with higher concentrations for all pollutants were mostly in downtown and around the railway station. Districts with a higher concentration for NOx (IRR = 1.05, for each 10 unit increase in air pollutant), benzene (IRR = 3.86), toluene (IRR = 1.50), ethylbenzene (IRR = 5.16), p-xylene (IRR = 9.41), o-xylene (IRR = 7.93), m-xylene (IRR = 2.63) and TBTEX (IRR = 1.21) were significantly associated with higher lung cancer incidence. Districts with a higher multiple air-pollution profile were also associated with more lung cancer incidence (IRR = 1.01). Our study shows a positive association between air pollution and lung cancer incidence. This association was stronger for, respectively, p-xylene, o-xylene, ethylbenzene, benzene, m-xylene and toluene

    U–Pb zircon geochronology, petrochemical and Sr–Nd isotopic characteristic of Late Neoproterozoic granitoids of the Bornaward complex (Bardaskan-NE Iran)

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    The Bornaward granitoids in the Taknar zone are located in the northeast of the central Iranian block in northeast Iran (Khorasan Razavi province), about 280 km southwest of Mashhad city and 28 km northwest of Bardaskan city. Taknar zone is an exotic block, bordered by two major faults, the Great Kavir fault in the south and Rivash fault in the north. Intrusive rocks of the study area, called the Bornaward granitoid complex (BGC), include of granite, alkali granite, syenogranite, leucogranite, granophyre, monzogranite, granodiorite, tonalite, diorite and gabbro intruded into the center of Taknar zone. These intrusive rocks affected low grade metamorphism. The results of U-Pb zircon dating on two granite samples, one belonging to the Taknar mine west of the study area and the other the Bornaward granitoids in the eastern part of study area, and also one granodiorite the Taknar mine area and one diorite the Bornaward area, yield ages of the granites as 540.5±2.9 Ma (Taknar mine area) and 550.41 3.21,-4.54 Ma (Bornaward area), the granodiorite as 550±6.9 Ma and diorite as 551.96±4.32 Ma, all Late Neoproterozoic. The Bornaward intrusive bodies are classified as belonging to the ilmenite-series of reduced granitoids. Some small high magnetite-granite and tonalite outcrops in the study area are classified as belonging to the magnetite-series of oxidized granitoids. Chemically, most granitoids of the study area are S-type middle-high metaluminous to slightlymiddle peraluminous and belong to tholeiite, calc-alkaline to high-K calc-alkaline rock series with enrichments in LIL (Cs, Rb and Ba, U, K, Zr, Y, Th) elements and depletion in HIL (Sr and Nb, Ta, Ti) elements. Chondrite-normalized Rare Earth Elements (REEs) plots indicate minor enrichments of LREEs in comparison with HREEs, with (La/Yb)N between 1.04 -7.90 and total of REEs of the samples between 44.8 ppm (minimum) and 293.5 ppm (maximum) with strong negative anomaly of Eu compared to other Rare Earth elements. The Bornaward granitoid have an initial 87Sr/86Sr and 143Nd/144Nd ranging 0.703514 to 0.716888 and 0.511585 to 0.512061, respectively, when recalculated to an age of 550 to 538 Ma, consistent with the new radiometric age results. Initial εNd isotope values for granite, granodiorite and diorite range -6.73 to 2.52. TDM age of the BGC is 1.08-1.70 Ga. This indicates that the Bornaward granitoid complex (BGC) derived partial melting of distinct basement source regions with very high initial 87Sr/86Sr and underwent extensive crustal contamination

    Multiple air pollutants exposure and leukaemia incidence in Tehran, Iran from 2010 to 2016: a retrospective cohort study

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    OBJECTIVE: Leukaemia is one of the most common cancers and may be associated with exposure to environmental carcinogens, especially outdoor air pollutants. The objective of this study was to investigate the association of ambient air pollution and leukaemia in Tehran, Iran. DESIGN: In this retrospective cohort study, data about the residential district of leukaemia cases diagnosed from 2010 to 2016 were inquired from the Ministry of Health cancer database. Data from a previous study were used to determine long-term average exposure to different air pollutants in 22 districts of Tehran. Latent profile analysis (LPA) was used to classify pollutants in two exposure profiles. The association between air pollutants and leukaemia incidence was analysed by negative binomial regression. SETTING: Twenty-two districts of Tehran megacity. PARTICIPANTS: Patients with leukaemia. OUTCOME MEASURES: The outcome variables were incidence rate ratios (IRR) of acute myeloid and lymphoid leukaemia across the districts of Tehran. RESULTS: The districts with higher concentrations for all pollutants were near the city centre. The IRR was positive but non-significant for most of the air pollutants. However, annual mean NOx was directly and significantly associated with total leukaemia incidence in the fully adjusted model (IRR (95% CI): 1.03 (1.003 to 1.06) per 10 ppb increase). Based on LPA, districts with a higher multiple air-pollutants profile were also associated with higher leukaemia incidence (IRR (95% CI): 1.003 (0.99 to 1.007) per 1 ppb increase). CONCLUSIONS: Our study shows that districts with higher air pollution (nitrogen oxides and multipollutants) have higher incidence rates of leukaemia in Tehran, Iran. This study warrants conducting further research with individual human data and better control of confounding

    Stringency of COVID-19 containment response policies and air quality changes: a global analysis across 1851 cities

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    The COVID-19 containment response policies (CRPs) had a major impact on air quality (AQ). These CRPs have been time-varying and location-specific. So far, despite having numerous studies on the effect of COVID-19 lockdown on AQ, a knowledge gap remains on the association between stringency of CRPs and AQ changes across the world, regions, nations, and cities. Here, we show that globally across 1851 cities (each more than 300000 people) in 149 countries, after controlling for the impacts of relevant covariates (e.g., meteorology), Sentinel-5P satellite-observed nitrogen dioxide (NO2) levels decreased by 4.9% (95% CI: 2.2, 7.6%) during lockdowns following stringent CRPs compared to pre-CRPs. The NO2 levels did not change significantly during moderate CRPs and even increased during mild CRPs by 2.3% (95% CI: 0.7, 4.0%), which was 6.8% (95% CI: 2.0, 12.0%) across Europe and Central Asia, possibly due to population avoidance of public transportation in favor of private transportation. Among 1768 cities implementing stringent CRPs, we observed the most NO2 reduction in more populated and polluted cities. Our results demonstrate that AQ improved when and where stringent COVID-19 CRPs were implemented, changed less under moderate CRPs, and even deteriorated under mild CRPs. These changes were location-, region-, and CRP-specific

    Access and utilisation of primary health care services comparing urban and rural areas of Riyadh Providence, Kingdom of Saudi Arabia

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    The Kingdom of Saudi Arabia (KSA) has seen an increase in chronic diseases. International evidence suggests that early intervention is the best approach to reduce the burden of chronic disease. However, the limited research available suggests that health care access remains unequal, with rural populations having the poorest access to and utilisation of primary health care centres and, consequently, the poorest health outcomes. This study aimed to examine the factors influencing the access to and utilisation of primary health care centres in urban and rural areas of Riyadh province of the KSA

    Prevalence of nosocomial infections in Iran: A systematic review and meta-analysis

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    Background: Nosocomial infections represent a serious public health concern worldwide, and, especially, in developing countries where, due to financial constraints, it is difficult to control infections. This study aimed to review and assess the prevalence of nosocomial infections in Iran. Methods: Different databases were searched between January 2000 and December 2017. To determine the pooled prevalence, the stochastic DerSimonian-Laird model was used, computing the effect size with its 95 confidence interval. To examine the heterogeneity among studies, the I2 test were conducted. The reporting of observational studies in epidemiology (STROBE) checklist was used to assess the methodological quality of observational studies. To further investigate the source of heterogeneity, meta-regression analyses stratified by publication year, sample size and duration of hospitalization in the hospital were carried out. Results: 52 studies were included. Based on the random-effects model, the overall prevalence of nosocomial infection in Iran was 4.5 95% CI: 3.5 to 5.7 with a high, statistically significant heterogeneity (I2=99.82%). A sensitivity analysis was performed to ensure the stability results. After removing each study, results did not change. A cumulative meta-analysis of the included studies was performed based on year of publication and the results did not change. In the present study, a high rate of infections caused by Klebsiella pneumoniae (urinary tract, respiratory tract, and bloodstream infections) was found. Conclusion: Preventing and reducing hospital infections can significantly impact on reducing mortality and health-related costs. Implementing ad hoc programs, such as training healthcare staff on admission to the hospital, may play an important role in reducing infections spreading. © Iran University of Medical Sciences

    Long-term exposure to air pollution and mortality in a Danish nationwide administrative cohort study: Beyond mortality from cardiopulmonary disease and lung cancer.

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    BACKGROUND: The association between long-term exposure to air pollution and mortality from cardiorespiratory diseases is well established, yet the evidence for other diseases remains limited. OBJECTIVES: To examine the associations of long-term exposure to air pollution with mortality from diabetes, dementia, psychiatric disorders, chronic kidney disease (CKD), asthma, acute lower respiratory infection (ALRI), as well as mortality from all-natural and cardiorespiratory causes in the Danish nationwide administrative cohort. METHODS: We followed all residents aged ≥ 30 years (3,083,227) in Denmark from 1 January 2000 until 31 December 2017. Annual mean concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), black carbon (BC), and ozone (warm season) were estimated using European-wide hybrid land-use regression models (100 m × 100 m) and assigned to baseline residential addresses. We used Cox proportional hazard models to evaluate the association between air pollution and mortality, accounting for demographic and socioeconomic factors. We additionally applied indirect adjustment for smoking and body mass index (BMI). RESULTS: During 47,023,454 person-years of follow-up, 803,881 people died from natural causes. Long-term exposure to PM2.5 (mean: 12.4 µg/m3), NO2 (20.3 µg/m3), and/or BC (1.0 × 10-5/m) was statistically significantly associated with all studied mortality outcomes except CKD. A 5 µg/m3 increase in PM2.5 was associated with higher mortality from all-natural causes (hazard ratio 1.11; 95% confidence interval 1.09-1.13), cardiovascular disease (1.09; 1.07-1.12), respiratory disease (1.11; 1.07-1.15), lung cancer (1.19; 1.15-1.24), diabetes (1.10; 1.04-1.16), dementia (1.05; 1.00-1.10), psychiatric disorders (1.38; 1.27-1.50), asthma (1.13; 0.94-1.36), and ALRI (1.14; 1.09-1.20). Associations with long-term exposure to ozone (mean: 80.2 µg/m3) were generally negative but became significantly positive for several endpoints in two-pollutant models. Generally, associations were attenuated but remained significant after indirect adjustment for smoking and BMI. CONCLUSION: Long-term exposure to PM2.5, NO2, and/or BC in Denmark were associated with mortality beyond cardiorespiratory diseases, including diabetes, dementia, psychiatric disorders, asthma, and ALRI

    Diminishing benefits of urban living for children and adolescents’ growth and development

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    Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified

    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world
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