1,029 research outputs found
Parietal disruption alters audiovisual binding in the sound-induced flash illusion
Selective attention and multisensory integration are fundamental to perception, but little is known about whether, or under what circumstances, these processes interact to shape conscious awareness. Here, we used transcranial magnetic stimulation (TMS) to investigate the causal role of attention-related brain networks in multisensory integration between visual and auditory stimuli in the sound-induced flash illusion. The flash illusion is a widely studied multisensory phenomenon in which a single flash of light is falsely perceived as multiple flashes in the presence of irrelevant sounds. We investigated the hypothesis that extrastriate regions involved in selective attention, specifically within the right parietal cortex, exert an influence on the multisensory integrative processes that cause the flash illusion. We found that disruption of the right angular gyrus, but not of the adjacent supramarginal gyrus or of a sensory control site, enhanced participants' veridical perception of the multisensory events, thereby reducing their susceptibility to the illusion. Our findings suggest that the same parietal networks that normally act to enhance perception of attended events also play a role in the binding of auditory and visual stimuli in the sound-induced flash illusion
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Proceedings of the Rank Forum on Vitamin D
The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations . 75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted
concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations
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Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study using data from the 2007 to 2009 Canadian Health Measures Survey
Background:
Exposure to solar ultraviolet-B (UV-B) radiation is a major source of vitamin D3. Chemistry climate models project decreases in ground-level solar erythemal UV over the current century. It is unclear what impact this will have on vitamin D status at the population level. The purpose of this study was to measure the association between ground-level solar UV-B and serum concentrations of 25-hydroxyvitamin D (25(OH)D) using a secondary analysis of the 2007 to 2009 Canadian Health Measures Survey (CHMS).
Methods:
Blood samples collected from individuals aged 12 to 79 years sampled across Canada were analyzed for 25(OH)D (n=4,398). Solar UV-B irradiance was calculated for the 15 CHMS collection sites using the Tropospheric Ultraviolet and Visible Radiation Model. Multivariable linear regression was used to evaluate the association between 25(OH)D and solar UV-B adjusted for other predictors and to explore effect modification.
Results:
Cumulative solar UV-B irradiance averaged over 91 days (91-day UV-B) prior to blood draw correlated significantly with 25(OH)D. Independent of other predictors, a 1 kJ/m 2
increase in 91-day UV-B was associated with a significant 0.5 nmol/L (95% CI 0.3-0.8) increase in mean 25(OH)D (P =0.0001). The relationship was stronger among younger individuals and those spending more time outdoors. Based on current projections of decreases in ground-level solar UV-B, we predict less than a 1 nmol/L decrease in mean 25(OH)D for the population.
Conclusions:
In Canada, cumulative exposure to ambient solar UV-B has a small but significant association with 25(OH)D concentrations. Public health messages to improve vitamin D status should target safe sun exposure with sunscreen use, and also enhanced dietary and supplemental intake and maintenance of a healthy body weight
Vitamin D during pregnancy: why observational studies suggest deficiency and interventional studies show no improvement in clinical outcomes? A narrative review
International audienc
Randomized comparison of the effects of the vitamin D(3 )adequate intake versus 100 mcg (4000 IU) per day on biochemical responses and the wellbeing of patients
BACKGROUND: For adults, vitamin D intake of 100 mcg (4000 IU)/day is physiologic and safe. The adequate intake (AI) for older adults is 15 mcg (600 IU)/day, but there has been no report focusing on use of this dose. METHODS: We compared effects of these doses on biochemical responses and sense of wellbeing in a blinded, randomized trial. In Study 1, 64 outpatients (recruited if summer 2001 25(OH)D <61 nmol/L) were given 15 or 100 mcg/day vitamin D in December 2001. Biochemical responses were followed at subsequent visits that were part of clinical care; 37 patients completed a wellbeing questionnaire in December 2001 and February 2002. Subjects for Study 2 were recruited if their 25(OH)D was <51 nmol/L in summer 2001. 66 outpatients were given vitamin D; 51 completed a wellbeing questionnaire in both December 2002 and February 2003. RESULTS: In Study 1, basal summer 25-hydroxyvitamin D [25(OH)D] averaged 48 ± 9 (SD) nmol/L. Supplementation for more than 6 months produced mean 25(OH)D levels of 79 ± 30 nmol/L for the 15 mcg/day group, and 112 ± 41 nmol/L for the 100 mcg/day group. Both doses lowered plasma parathyroid hormone with no effect on plasma calcium. Between December and February, wellbeing score improved more for the 100-mcg/day group than for the lower-dosed group (1-tail Mann-Whitney p = 0.036). In Study 2, 25(OH)D averaged 39 ± 9 nmol/L, and winter wellbeing scores improved with both doses of vitamin D (two-tail p < 0.001). CONCLUSION: The highest AI for vitamin D brought summertime 25(OH)D to >40 nmol/L, lowered PTH, and its use was associated with improved wellbeing. The 100 mcg/day dose produced greater responses. Since it was ethically necessary to provide a meaningful dose of vitamin D to these insufficient patients, we cannot rule out a placebo wellbeing response, particularly for those on the lower dose. This work confirms the safety and efficacy of both 15 and 100 mcg/day vitamin D(3 )in patients who needed additional vitamin D
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Preparation for Rural Practice with a Multimodal Rural Emergency Medicine Curriculum
Rural regions face emergency medicine (EM) physician shortages. Most training programs are located in cities and lack rural clinical experiences, didactics, and mentorship to excite and prepare residents for rural EM practice. There is limited data on optimal training methods for preparing residents for rural practice. To address this need for rural EM training and workforce, we developed a rural EM curriculum. We began with a two-year case review from critical access emergency departments. Rural EM skills were defined and taught using lectures, simulation cases, and clinical rotations. We obtained quantitative and qualitative feedback from the first ten residents participating in the curriculum. Qualitatively, 10/10 residents gained new skills and found these experiences valuable to their training and career choice, with 100% expressing interest in rural practice and 75% choosing a rural practice. Quantitatively, residents managed a greater variability in patient acuity and volume and performed a greater variety of procedures compared to their academic center rotations, all while gaining unique skills from the challenges of a rural environment. Focused rural emergency medicine clinical experience and didactic training during residency are a promising approach to bridge the gap between urban tertiary care training programs and rural emergency care needs
25-Hydroxyvitamin D and pre-clinical alterations in inflammatory and hemostatic markers: a cross sectional analysis in the 1958 British Birth Cohort
BACKGROUND: Vitamin D deficiency has been suggested as a cardiovascular risk factor, but little is known about underlying mechanisms or associations with inflammatory or hemostatic markers. Our aim was to investigate the association between 25-hydroxyvitamin D [25(OH)D, a measure for vitamin D status] concentrations with pre-clinical variations in markers of inflammation and hemostasis. METHODOLOGY/PRINCIPAL FINDINGS: Serum concentrations of 25(OH)D, C-reactive protein (CRP), fibrinogen, D-dimer, tissue plasminogen activator (tPA) antigen, and von Willebrand factor (vWF) were measured in a large population based study of British whites (aged 45 y). Participants for the current investigation were restricted to individuals free of drug treated cardiovascular disease (n = 6538). Adjusted for sex and month, 25(OH)D was inversely associated with all outcomes (p or =75 nmol/l compared to < 25 nmol/l. D-dimer concentrations were lower for participants with 25(OH)D 50-90 nmol/l compared to others (quadratic term p = 0.01). We also examined seasonal variation in hemostatic and inflammatory markers, and evaluated 25(OH)D contribution to the observed patterns using mediation models. TPA concentrations varied by season (p = 0.02), and much of this pattern was related to fluctuations in 25(OH)D concentrations (p < or =0.001). Some evidence of a seasonal variation was observed also for fibrinogen, D-dimer and vWF (p < 0.05 for all), with 25(OH)D mediating some of the pattern for fibrinogen and D-dimer, but not vWF. CONCLUSIONS: Current vitamin D status was associated with tPA concentrations, and to a lesser degree with fibrinogen and D-dimer, suggesting that vitamin D status/intake may be important for maintaining antithrombotic homeostasi
Child Advocacy Studies (CAST): A National Movement to Improve the Undergraduate and Graduate Training of Child Protection Professionals
An Appraisal to Address Health Consequences of Vitamin D Deficiency With Food Fortification and Supplements: Time to Act!
A symposium entitled "Vitamin D in Prevention and Therapy" was held on May 4-5, 2022, in Homburg, Germany to discuss important new advances in the field, including identification of new vitamin D signaling pathways, of new biologic effects of vitamin D-compounds (e.g., on the microbiome), and convincing proof of the relevance of vitamin D deficiency for the risk and outcome of many chronic diseases, including cancer, cardio-vascular, auto-immune, metabolic, and infectious diseases. Concerning the COVID-19-pandemic, an inverse association between 25(OH)D serum concentrations and SARS-CoV-2-infections, morbidity, and mortality was shown. In relation to cancer, several meta-analyses recently demonstrated an association of vitamin D-supplementation with significantly decreased mortality rates, which presumably would reduce health care costs. Considering the impressive body of evidence and the high safety of oral supplementation and food fortification with vitamin D, it was concluded that there is now an urgent need to act. In many countries worldwide, health care authorities need to increase efforts to address vitamin D deficiency, e.g., via food fortification and/or supplementation with vitamin D, and/or promoting moderate UV-exposure. It was estimated that in many countries, vitamin D intakes of the order of appr. 1,000 IE (25 μg)/day would be needed to bring and/or keep the vast majority of people over a serum 25(OH)D threshold of 20 ng/ml (50 nmol/l), which would be difficult to obtain alone from food fortification. New developments in personalized medicine may represent helpful tools to identify populations at risk for vitamin D deficiency and their responsiveness to vitamin D treatment
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