1,374 research outputs found
Evaluation of a novel assay for detection of the fetal marker RASSF1A: facilitating improved diagnostic reliability of noninvasive prenatal diagnosis
BackgroundAnalysis of cell free fetal (cff) DNA in maternal plasma is used routinely for non invasive prenatal diagnosis (NIPD) of fetal sex determination, fetal rhesus D status and some single gene disorders. True positive results rely on detection of the fetal target being analysed. No amplification of the target may be interpreted either as a true negative result or a false negative result due to the absence or very low levels of cffDNA. The hypermethylated RASSF1A promoter has been reported as a universal fetal marker to confirm the presence of cffDNA. Using methylation-sensitive restriction enzymes hypomethylated maternal sequences are digested leaving hypermethylated fetal sequences detectable. Complete digestion of maternal sequences is required to eliminate false positive results.MethodscfDNA was extracted from maternal plasma (n = 90) and digested with methylation-sensitive and insensitive restriction enzymes. Analysis of RASSF1A, SRY and DYS14 was performed by real-time PCR.ResultsHypermethylated RASSF1A was amplified for 79 samples (88%) indicating the presence of cffDNA. SRY real time PCR results and fetal sex at delivery were 100% accurate. Eleven samples (12%) had no detectable hypermethylated RASSF1A and 10 of these (91%) had gestational ages less than 7 weeks 2 days. Six of these samples were male at delivery, five had inconclusive results for SRY analysis and one sample had no amplifiable SRY.ConclusionUse of this assay for the detection of hypermethylated RASSF1A as a universal fetal marker has the potential to improve the diagnostic reliability of NIPD for fetal sex determination and single gene disorders
The soil and plant biogeochemistry sampling design for The National Ecological Observatory Network
Human impacts on biogeochemical cycles are evident around the world, from changes to forest structure and function due to atmospheric deposition, to eutrophication of surface waters from agricultural effluent, and increasing concentrations of carbon dioxide (CO2) in the atmosphere. The National Ecological Observatory Network (NEON) will contribute to understanding human effects on biogeochemical cycles from local to continental scales. The broad NEON biogeochemistry measurement design focuses on measuring atmospheric deposition of reactive mineral compounds and CO2 fluxes, ecosystem carbon (C) and nutrient stocks, and surface water chemistry across 20 eco‐climatic domains within the United States for 30 yr. Herein, we present the rationale and plan for the ground‐based measurements of C and nutrients in soils and plants based on overarching or “high‐level” requirements agreed upon by the National Science Foundation and NEON. The resulting design incorporates early recommendations by expert review teams, as well as recent input from the larger natural sciences community that went into the formation and interpretation of the requirements, respectively. NEON\u27s efforts will focus on a suite of data streams that will enable end‐users to study and predict changes to biogeochemical cycling and transfers within and across air, land, and water systems at regional to continental scales. At each NEON site, there will be an initial, one‐time effort to survey soil properties to 1 m (including soil texture, bulk density, pH, baseline chemistry) and vegetation community structure and diversity. A sampling program will follow, focused on capturing long‐term trends in soil C, nitrogen (N), and sulfur stocks, isotopic composition (of C and N), soil N transformation rates, phosphorus pools, and plant tissue chemistry and isotopic composition (of C and N). To this end, NEON will conduct extensive measurements of soils and plants within stratified random plots distributed across each site. The resulting data will be a new resource for members of the scientific community interested in addressing questions about long‐term changes in continental‐scale biogeochemical cycles, and is predicted to inspire further process‐based research
Bidirectional lipid droplet velocities are controlled by differential binding strengths of HCV Core DII protein
Host cell lipid droplets (LD) are essential in the hepatitis C virus (HCV) life cycle and are targeted by the viral capsid core protein. Core-coated LDs accumulate in the perinuclear region and facilitate viral particle assembly, but it is unclear how mobility of these LDs is directed by core. Herein we used two-photon fluorescence, differential interference contrast imaging, and coherent anti-Stokes Raman scattering microscopies, to reveal novel core-mediated changes to LD dynamics. Expression of core protein’s lipid binding domain II (DII-core) induced slower LD speeds, but did not affect directionality of movement on microtubules. Modulating the LD binding strength of DII-core further impacted LD mobility, revealing the temporal effects of LD-bound DII-core. These results for DII-core coated LDs support a model for core-mediated LD localization that involves core slowing down the rate of movement of LDs until localization at the perinuclear region is accomplished where LD movement ceases. The guided localization of LDs by HCV core protein not only is essential to the viral life cycle but also poses an interesting target for the development of antiviral strategies against HCV
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Common bottlenose dolphin, Tursiops truncatus, seasonal habitat use and associations with habitat characteristics in Roanoke Sound, North Carolina
Understanding how habitat characteristics influence common bottlenose dolphin, Tursiops truncatus, distribution and behavior can be useful for conservation. The dolphin community in Roanoke Sound, North Carolina primarily exhibits seasonal residency and there is limited information on their habitat use. The objectives of this study were to increase habitat use knowledge and determine the relationship between habitat characteristics and dolphin distribution using standardized photographic-identification data (2009 – 2017). A hot spot (Getis-Ord Gi*) analysis showed dolphins frequently use the southern region containing the mouth of the estuary for feeding and traveling. Habitat characteristics were modeled with zero-altered gamma (ZAG), generalized linear (GLM), and generalized additive (GAM) models to predict dolphin group density. Models showed that groups were more likely to be present in areas with greater benthic slope variation and shallow areas closer to land, and that different habitat characteristics were associated with feed, social, and travel activities. This study suggests that Roanoke Sound provides a seasonal foraging area and travel corridor between the estuaries and coastal waters. This information contributes baseline knowledge of how habitat potentially influences dolphin distribution and behavior which can be useful for management and conservation, especially in areas where habitat changes and impacts need to be assessed
Impact of EMA regulatory label changes on systemic diclofenac initiation, discontinuation, and switching to other pain medicines in Scotland, England, Denmark, and The Netherlands
Purpose: In June 2013 a European Medicines Agency referral procedure concluded that diclofenac was associated with an elevated risk of acute cardiovascular events and contraindications, warnings, and changes to the product information were implemented across the European Union. This study measured the impact of the regulatory action on the prescribing of systemic diclofenac in Denmark, The Netherlands, England, and Scotland. Methods: Quarterly time series analyses measuring diclofenac prescription initiation, discontinuation and switching to other systemic nonsteroidal anti-inflammatory (NSAIDs), topical NSAIDs, paracetamol, opioids, and other chronic pain medication in those who discontinued diclofenac. Absolute effects were estimated using interrupted time series regression. Results: Overall, diclofenac prescription initiations fell during the observation periods of all countries. Compared with Denmark where there appeared to be amore limited effect, the regulatory action was associated with significant immediate reductions in diclofenac initiation in The Netherlands (−0.42%, 95% CI, −0.66% to −0.18%), England (−0.09%, 95% CI, −0.11% to −0.08%), and Scotland (−0.67%, 95% CI, −0.79% to −0.55%); and falling trends in diclofenac initiation in the Netherlands (−0.03%, 95% CI, −0.06% to −0.01% per quarter) and Scotland (−0.04%, 95% CI, −0.05% to −0.02% per quarter). There was no significant impact on diclofenac discontinuation in any country. The regulatory action was associated with modest differences in switching to other pain medicines following diclofenac discontinuation. Conclusions: The regulatory action was associated with significant reductions in overall diclofenac initiation which varied by country and type of exposure. There was no impact on discontinuation and variable impact on switching
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Application of change point analysis to daily influenza-like illness emergency department visits
Background: The utility of healthcare utilization data from US emergency departments (EDs) for rapid monitoring of changes in influenza-like illness (ILI) activity was highlighted during the recent influenza A (H1N1) pandemic. Monitoring has tended to rely on detection algorithms, such as the Early Aberration Reporting System (EARS), which are limited in their ability to detect subtle changes and identify disease trends. Objective: To evaluate a complementary approach, change point analysis (CPA), for detecting changes in the incidence of ED visits due to ILI. Methodology and principal findings Data collected through the Distribute project (isdsdistribute.org), which aggregates data on ED visits for ILI from over 50 syndromic surveillance systems operated by state or local public health departments were used. The performance was compared of the cumulative sum (CUSUM) CPA method in combination with EARS and the performance of three CPA methods (CUSUM, structural change model and Bayesian) in detecting change points in daily time-series data from four contiguous US states participating in the Distribute network. Simulation data were generated to assess the impact of autocorrelation inherent in these time-series data on CPA performance. The CUSUM CPA method was robust in detecting change points with respect to autocorrelation in time-series data (coverage rates at 90% when −0.2≤ρ≤0.2 and 80% when −0.5≤ρ≤0.5). During the 2008–9 season, 21 change points were detected and ILI trends increased significantly after 12 of these change points and decreased nine times. In the 2009–10 flu season, we detected 11 change points and ILI trends increased significantly after two of these change points and decreased nine times. Using CPA combined with EARS to analyze automatically daily ED-based ILI data, a significant increase was detected of 3% in ILI on April 27, 2009, followed by multiple anomalies in the ensuing days, suggesting the onset of the H1N1 pandemic in the four contiguous states. Conclusions and significance As a complementary approach to EARS and other aberration detection methods, the CPA method can be used as a tool to detect subtle changes in time-series data more effectively and determine the moving direction (ie, up, down, or stable) in ILI trends between change points. The combined use of EARS and CPA might greatly improve the accuracy of outbreak detection in syndromic surveillance systems
Changing the Face of an Institution: Creative Partnerships for Women’s Professional Development
Purpose of program/study/research:To accelerate the advancement of women professionals at an academic medical center through creative collaboration.
Methodology (including study design, analysis, and evaluation):The UMass Medical School Women’s Faculty Committee (WFC) initiated a partnership with the medical library to compete successfully to host the traveling exhibition “Changing the Face of Medicine: Celebrating America’s Women Physicians.” Concurrent with the 6-week exhibition, fifteen events brought local and nationally prominent women together for mentoring activities, an original dramatic production, and an awards luncheon for women faculty. Women featured in the exhibit as well as its Visiting Curator spoke at UMMS about their research and career challenges, read from their published works, and were featured at graduation and a regional medical society event.
Results:Application-writing and event planning sessions forged robust working relationships among top-ranking administrators, senior and junior faculty, and staff. The exhibition increased opportunities for administration, faculty, and students to understand the impact of women in medicine, their leadership potential, and historical contributions. It also generated new mentor/mentee relationships and grant-writing collaborations. The exhibition’s national recognition helped draw a larger, more diverse and gender-balanced audience (575+ people) to the events enhancing the visibility of the WFC, as evidenced by institutional funding for women faculty to attend the AAMC WIM professional development workshops and ELAM for the first time.
Conclusion(s):Creative partnerships, motivated by the opportunity to host “Changing the Face of Medicine,” produced greater than expected gains for women faculty, generating new awareness and understanding of women’s accomplishments and leadership potential. This partnership allowed for a wide range of multi-disciplinary efforts, strengthening networking across silos, and advancing the goals of women in an academic medical center.
Presented October 29, 2006 at AAMC 2006 Annaul Meeting, Seattle, WA
Predicted Infrared and Raman Spectra for Neutral Ti_8C_12 Isomers
Using a density-functional based algorithm, the full IR and Raman spectra are
calculated for the neutral Ti_8C_12 cluster assuming geometries of Th, Td, D2d
and C3v symmetry. The Th pentagonal dodecahedron is found to be dynamically
unstable. The calculated properties of the relaxed structure having C3v
symmetry are found to be in excellent agreement with experimental gas phase
infrared results, ionization potential and electron affinity measurements.
Consequently, the results presented may be used as a reference for further
experimental characterization using vibrational spectroscopy.Comment: 6 pages, 5 figures. Physical Review A, 2002 (in press
ДОСЛІДЖЕННЯ ПРОЦЕСУ ОХОЛОДЖЕННЯ БАГАТОШАРОВОЇ СУЦІЛЬНОЇ СФЕРИЧНОЇ КОНСТРУКЦІЇ
Purpose. The work aims to study the process of cooling the spherical structure "ball inside a multilayer spherical shell".Methodology. The paper uses the idea of a boundary transition, which is realised through the solution of the auxiliary problem of determining the distribution of a nonstationary temperature field in a multilayer hollow plane of a structure with an "extracted" sphere of sufficiently small radius. The symmetry condition is replaced by the zero condition of the second kind. Implementation of the solution of the auxiliary problem by applying the method of reduction using the concept of quasi-derivatives using the modified method of eigenfunctions. To find the final solution of the problems of the original problem, the radius of the extracted sphere is directed to zero.Results. The proposed work is devoted to the application of the direct method to the study of cooling processes in the system of spherical bodies - "ball inside a multilayer shell". It is assumed that there is a perfect thermal contact between thelayers. At the initial point in time, the outer surface of such a system is cooled to a certain constant temperature, which is constant throughout the cooling process. The cooling takes place evenly so that the isotherms inside this structure areconcentric spheres, i.e. the problem is symmetric and is solved for the first time in such a setting. To solve this problem, the auxiliary problem of determining the distribution of a nonstationary temperature field in a multilayer hollow sphericalstructure with an "extracted" sphere of a sufficiently small radius is set in parallel. The condition of symmetry of the initial problem is replaced by the condition of the second kind on the inner surface of this structure.To find the solution to the original problem, we used the idea of a boundary transition by directing the radius of the extracted sphere to zero. It is established that with this approach all eigenfunctions of the corresponding problem have nosingularities at zero, which means that the solutions of the original problem are limited in the whole construction. To illustrate the proposed method, a model example of finding the temperature field distribution in a sphere in a three-layer shell with different thermophysical characteristics of materials is solved. The results of calculations of the graph of temperature change depend on time and spatial coordinates.
Note that the replacement of the boundary condition of the first kind with any other boundary condition (for example, the third kind) does not affect the scheme of solving similar problems.Мета роботи. Метою роботи є дослідження процесу охолодження сферичної конструкції «куля всередині багатошарової сферичної оболонки».Методи дослідження. У роботі використано ідею граничного переходу, яка реалізується через постановку допоміжної задачі про визначення розподілу нестаціонарного температурного поля у багатошаровій порожнистій сферичній конструкції з «вилученою» кулею достатньо малого радіуса. Умова симетрії замінюється на нульову крайову умову другого роду. Реалізація розв’язку допоміжної задачі проводиться шляхом застосування методу редукції із використанням концепції квазіпохідних із застосуванням модифікованого методу власних функцій. Для знаходження остаточного розв’язку задачі вихідної задачі радіус вилученої кулі спрямовується до нуля.Результати. Запропонована робота присвячена застосуванню прямого методу до дослідження процесів охолодження в системі сферичних тіл – «куля всередині багатошарової оболонки». Припускається що між шарами існує ідеальний тепловий контакт. У початковий момент часу зовнішня поверхня такої системи охолоджується до деякої постійної температури, яка є сталою протягом всього процесі охолодження. Охолодження проходить рівномірно, так що ізотерми всередині цієї конструкції являють собою концентричні сфери, тобто задача є симетричною і в такій постановці розв’язана вперше. Для розв’язування такої задачі паралельно ставиться допоміжна задача про визначення розподілу нестаціонарного температурного поля у багатошаровій порожнистій сферичній конструкції з «вилученою» кулею достатньо малого радіуса. При цьому умова симетрії вихідної задачі замінюється умовою другого роду на внутрішній поверхні цієї конструкції.Для знаходження розв’язку вихідної задачі використано ідею граничного переходу шляхом прямування радіуса вилученої кулі до нуля. Встановлено, що при такому підході всі власні функції відповідної задачі на власні значення не мають особливостей в нулі, а це означає, що й розв’язки вихідної задачі є обмеженими у всій конструкції. Для ілюстрації запропонованого методу розв’язано модельний приклад про знаходження розподілу температурного поля у кулі в тришаровій оболонці з різними теплофізичними характеристиками матеріалів. Результати обчислень графіка зміни температури залежно від часу та просторової координати.Зауважимо, що при цьому заміна крайової умови першого роду на будь яку іншу крайову умову (наприклад, третього роду) не впливає на схему розв’язування аналогічно поставлених задач
The Role of Relationships in the Professional Formation of Physicians
BACKGROUND: Studies of the professional development of physicians highlight the important effect that the learning environment, or \ hidden curriculum,\ has in shaping student attitudes, behaviors, and values. We conducted this study to better understand the role that relationships have in mediating these effects of the hidden curriculum. [See PDF for complete abstract
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