201 research outputs found
Chemical nonlinearities in relating intercontinental ozone pollution to anthropogenic emissions
Model studies typically estimate intercontinental influence on surface ozone by perturbing emissions from a source continent and diagnosing the ozone response in the receptor continent. Since the response to perturbations is non-linear due to chemistry, conclusions drawn from different studies may depend on the magnitude of the applied perturbation. We investigate this issue for intercontinental transport between North America, Europe, and Asia with sensitivity simulations in three global chemical transport models. In each region, we decrease anthropogenic emissions of NOx and nonmethane volatile organic compounds (NMVOCs) by 20% and 100%. We find strong nonlinearity in the response to NOx perturbations outside summer, reflecting transitions in the chemical regime for ozone production. In contrast, we find no significant nonlinearity to NOx perturbations in summer or to NMVOC perturbations year-round. The relative benefit of decreasing NOx vs. NMVOC from current levels to abate intercontinental pollution increases with the magnitude of emission reductions
The Use of Health Service Areas for Measuring Provider Availability
Measurement of the availability of health care providers in a geographic area is a useful component in assessing access to health care. One of the problems associated with the county provider-to-population ratio as a measure of availability is that patients frequently travel outside their counties of residence for health care, especially those residing in non-metropolitan counties. Thus, in measuring the number of providers per capita, it is important that the geographic unit of analysis be a health service area. We have defined health care service areas for the coterminous United States, based on 1988 Medicare data on travel patterns between counties for routine hospital care. We used hierarchical cluster analysis to group counties into 802 service areas. More than one half of the service areas include only non-metropolitan counties. The service areas vary substantially in the availability of health care resources as measured by physicians and hospital beds per 100,000 population. For almost all of the service areas, the majority of hospital stays by area residents occur within the service area. In contrast, for 39 percent of counties, the majority of hospital stays by county residents occur outside the county. Thus, the service areas are a more appropriate georgraphic unit than the county for measuring the availability of health care
Assessment of Olfactory Processing in Parkinson’s Disease Patients
Background: Hyposmia is an early symptom of Parkinson’s Disease (PD) that often predates motor symptoms by years. Hyposmia has been shown to have a more consistent link to idiopathic PD than to other movement disorders. Olfaction has the potential to be used as a biomarker for PD, either through clinical evaluation or imaging.
Objectives: This study uses functional magnetic resonance imaging (fMRI) to assess differences in olfaction pathways between anosmic early PD patients and age and gender-matched controls.
Methods: 12 PD patients and 12 age- and gender-matched control subjects were recruited from the subject panel of a previous UMMS study on olfaction and PD. All PD patients were determined to be anosmic, and all controls were determined to have normal olfaction for their age and gender. All subjects underwent fMRI including periods with and without odorant exposure. Statistical analysis was performed using SPM8, using a general linear model to calculate BOLD signal changes for each scent relative to room air. A random effect model was used to infer general population effects.
Results: Control subjects showed significant activation in the piriform cortex, anterior olfactory nucleus, insula, hippocampus and temporal lobe, all regions associated with olfactory processing. Relative to control subjects, PD patients showed no significant BOLD activation in the olfactory pathways of the brain. In response to a citrus scent, PD patients showed activation in the superior and middle frontal lobe, as well as the cingulate gyrus. In response to a cinnamon scent, PD patients showed significant activation in the precuneus and paracentral lobule as well as lower levels of activation in the frontal lobe. PD patients showed no significant areas of activation in response to a mint scent.
Conclusion: Our results suggest that anosmic PD patients do not show activation of the olfactory pathways in the brain on exposure to these odorants. Taken together with previous studies, this suggests that BOLD activation in these regions of the brain can reflect clinical olfactory capability. In addition, PD patients show areas of increased activation, particularly in the frontal lobe. These distinct patterns of BOLD activation allow us to consider the feasibility of fMRI as a biomarker for diagnosis and evaluation of PD
Comparison of quantitative trait loci methods:Total expression and allelic imbalance method in brain RNA-seq
BackgroundOf the 108 Schizophrenia (SZ) risk-loci discovered through genome-wide association studies (GWAS), 96 are not altering the sequence of any protein. Evidence linking non-coding risk-SNPs and genes may be established using expression quantitative trait loci (eQTL). However, other approaches such allelic expression quantitative trait loci (aeQTL) also may be of use.MethodsWe applied both the eQTL and aeQTL analysis to a biobank of deeply sequenced RNA from 680 dorso-lateral pre-frontal cortex (DLPFC) samples. For each of 340 genes proximal to the SZ risk-SNPs, we asked how much SNP-genotype affected total expression (eQTL), as well as how much the expression ratio between the two alleles differed from 1:1 as a consequence of the risk-SNP genotype (aeQTL).ResultsWe analyzed overlap with comparable eQTL-findings: 16 of the 30 risk-SNPs known to have gene-level eQTL also had gene-level aeQTL effects. 6 of 21 risk-SNPs with known splice-eQTL had exon-aeQTL effects. 12 novel potential risk genes were identified with the aeQTL approach, while 55 tested SNP-pairs were found as eQTL but not aeQTL. Of the tested 108 loci we could find at least one gene to be associated with 21 of the risk-SNPs using gene-level aeQTL, and with an additional 18 risk-SNPs using exon-level aeQTL.ConclusionOur results suggest that the aeQTL strategy complements the eQTL approach to susceptibility gene identification
Pilot study evaluating the effects of an intervention to enhance culturally appropriate hypertension education among healthcare providers in a primary care setting
Background: To improve hypertension care for ethnic minority patients of African descent in the Netherlands, we developed a provider intervention to facilitate the delivery of culturally appropriate hypertension education. This pilot study evaluates how the intervention affected the attitudes and perceived competence of hypertension care providers with regard to culturally appropriate care.Methods: Pre- and post-intervention questionnaires were used to measure the attitudes, experienced barriers, and self-reported behaviour of healthcare providers with regard to culturally appropriate cardiovascular and general care at three intervention sites (N = 47) and three control sites (N = 35).Results: Forty-nine participants (60%) completed questionnaires at baseline (T0) and nine months later (T1). At T1, healthcare providers who received the intervention found it more important to consider the patient's culture when delivering care than healthcare providers who did not receive the intervention (p = 0.030). The intervention did not influence ex
Metropolitan New York in the Greenhouse: Air Quality and Health Effects
A variety of potential effects on human health resulting from climate change have been identified in several assessments. According to an international panel{sup 1} they include direct effects of extreme temperatures on cardiovascular deaths, secondary effects due to vector-borne diseases or crop yields, and tertiary effects such as those that might arise from conflicts over freshwater supplies. To this fist we add the secondary effects of increased air pollution, which may result either directly from climate change or indirectly from increased air conditioning loads and the corresponding pollutant emissions from electric utilities. Higher ozone concentrations have been linked to increased ambient temperatures by both theory and observations of monitoring data. A similar association with particulate matter has been limited to observations, thus far. The pollution-heat linkage has been recognized before` but health effects have not been evaluated in terms of predictions of the joint effects of both agents. This paper has been prepared in two sections. First, we discuss the ozone situation with special reference to the Northeast Corridor and New York. In the second section, we present estimates of the health effects of climate change on New York and discuss some mitigation options
Clinical realism: a new literary genre and a potential tool for encouraging empathy in medical students
Background: Empathy has been re-discovered as a desirable quality in doctors. A number of approaches using the medical humanities have been advocated to teach empathy to medical students. This paper describes a new approach using the medium of creative writing and a new narrative genre: clinical realism. Methods: Third year students were offered a four week long Student Selected Component (SSC) in Narrative Medicine and Creative Writing. The creative writing element included researching and creating a character with a life-changing physical disorder without making the disorder the focus of the writing. The age, gender, social circumstances and physical disorder of a character were randomly allocated to each student. The students wrote repeated assignments in the first person, writing as their character and including details of living with the disorder in all of their narratives. This article is based on the work produced by the 2013 cohort of students taking the course, and on their reflections on the process of creating their characters. Their output was analysed thematically using a constructivist approach to meaning making. Results: This preliminary analysis suggests that the students created convincing and detailed narratives which included rich information about living with a chronic disorder. Although the writing assignments were generic, they introduced a number of themes relating to illness, including stigma, personal identity and narrative wreckage. Some students reported that they found it difficult to relate to “their” character initially, but their empathy for the character increased as the SSC progressed. Conclusion: Clinical realism combined with repeated writing exercises about the same character is a potential tool for helping to develop empathy in medical students and merits further investigation
The state of play: securities of childhood - insecurities of children
This article is broadly concerned with the positioning of children, both within and outside the subject area of International Relations. It considers the costs of an adult- 5 centric standpoint in security studies and contrasts this with investments made seemingly on behalf of children and their security. It begins by looking at how children and childhoods are constructed and contained - yet also defy categorization - at some cost to their protection. The many competing children and childhoods that are invoked in security discourses and partially sustain their victimcy are then illustrated. It is 10 argued that at their entry point into academia they are essentialized and sentimentalized. Power relations which subvert, yet also rely on children and childhoods can only be disrupted through a reconfiguration of politics and agency which includes an engagement with political literacy on a societal level and acknowledgement of the ubiquitous presence of war in all our live
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