153 research outputs found
Stability of E' centers induced by 4.7eV laser radiation in SiO2
The kinetics of E' centers (silicon dangling bonds) induced by 4.7eV pulsed
laser irradiation in dry fused silica was investigated by in situ optical
absorption spectroscopy. The stability of the defects, conditioned by reaction
with mobile hydrogen of radiolytic origin, is discussed and compared to results
of similar experiments performed on wet fused silica. A portion of E' and
hydrogen are most likely generated by laser-induced breaking of Si-H
precursors, while an additional fraction of the paramagnetic centers arise from
another formation mechanism. Both typologies of E' participate to the reaction
with H_2 leading to the post-irradiation decay of the defects. This annealing
process is slowed down on decreasing temperature and is frozen at T=200K,
consistently with the diffusion properties of H_2 in silica.Comment: 12 pages, 3 figures, in press on J. Non cryst. solids (2007
The Effect of Gibberellic Acid Treatment on the Growth of Dwarf Setaria Mutations
Dwarfism is a common mutation found in many organisms and Setaria (millets) is no different. In millets and other plants, a reduction or complete lack of production of necessary hormones such as Gibberellic acid (GA), auxin, or Brassinosteroid can cause a mutantâs vertical and sometimes outward growth to be significantly reduced when compared to a wild type of the same variety. A typical solution to this mutation is the application of a hormone solution to allow the plantâs cells and organs to have access to the hormones needed to continue growing at an average rate. We decided to test an application method by applying a solution of 15 ppm of GA in 1L of water, at three different rates to four different varieties of millet including one wild type and three different mutant types. Our experimental results come from measuring the plantâs growth (using centimeters) three times a week and recording that data to find the average growth of each group. We have been testing this experiment over the course of three weeks and will be presenting evidence to show that the application of Gibberellic acid solution improves the growth of all millets including Dwarf mutants
Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing
The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals suffering from chronic medical conditions facile assessment of their immediate physiological state. Furthermore, it could serve as a research tool for analysis of complex, multifactorial medical conditions. In order for such a multianalyte sensor to be realized, it must be minimally invasive, sampling of interstitial fluid must occur without pain or harm to the user, and analysis must be rapid as well as selective
Domain Specific Self-Efficacy Mediates the Impact of Pain Catastrophizing on Pain and Disability in Overweight and Obese Osteoarthritis Patients
This study examined whether self-efficacy mediated the relationship between pain catastrophizing and pain and disability. Participants were 192 individuals diagnosed with osteoarthritis (OA) of the knees who were overweight or obese. Multiple mediator analyses were conducted to simultaneously test self-efficacy for pain control, physical function, and emotional symptoms as mediators while controlling for demographic and medical status variables. Higher pain catastrophizing was associated with lower self-efficacy in all three domains (ps< .05). Self-efficacy for pain control fully mediated the relationship between pain catastrophizing and pain (Beta=.08, Sobel test Z=1.97, p<.05). The relationship between pain catastrophizing and physical disability was fully mediated by self-efficacy for physical function (Beta=.06, Sobel test Z=1.95, p=.05). Self-efficacy for emotional symptoms partially mediated the relationship between pain catastrophizing and psychological disability (Beta=. 12, Sobel test Z=2.92, p<.05). These results indicate that higher pain catastrophizing contributed to greater pain and disability via lower domain-specific self-efficacy. Efforts to reduce pain and improve functioning in OA patients should consider addressing pain catastrophizing and domain specific selfefficacy. Pain catastrophizing may be addressed through cognitive therapy techniques and selfefficacy may be enhanced through practice of relevant skills and personal accomplishments. Perspective- This paper found that higher pain catastrophizing contributed to great pain and disability via domain specific self-efficacy. These results suggest that treatment efforts to reduce pain and improve functioning in OA patients who are overweight or obese should consider addressing both pain catastrophizing and self-efficacy. Originally published Journal of Pain, Vol. 9, No. 10, Oct 200
Pain coping skills training for African Americans with osteoarthritis (STAART): study protocol of a randomized controlled trial
Background: African Americans bear a disproportionate burden of osteoarthritis (OA), with higher prevalence rates, more severe pain, and more functional limitations. One key barrier to addressing these disparities has been limited engagement of African Americans in the development and evaluation of behavioral interventions for management of OA. Pain Coping Skills Training (CST) is a cognitive-behavioral intervention with shown efficacy to improve OA-related pain and other outcomes. Emerging data indicate pain CST may be a promising intervention for reducing racial disparities in OA symptom severity. However, there are important gaps in this research, including incorporation of stakeholder perspectives (e.g. cultural appropriateness, strategies for implementation into clinical practice) and testing pain CST specifically among African Americans with OA. This study will evaluate the effectiveness of a culturally enhanced pain CST program among African Americans with OA.
Methods/Design: This is a randomized controlled trial among 248 participants with symptomatic hip or knee OA, with equal allocation to a pain CST group and a wait list (WL) control group. The pain CST program incorporated feedback from patients and other stakeholders and involves 11 weekly telephone-based sessions. Outcomes are assessed at baseline, 12ĂÂ weeks (primary time point), and 36ĂÂ weeks (to assess maintenance of treatment effects). The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index, and secondary outcomes include self-efficacy, pain coping, pain interference, quality of life, depressive symptoms, and global assessment of change. Linear mixed models will be used to compare the pain CST group to the WL control group and explore whether participant characteristics are associated with differential improvement in the pain CST program. This research is in compliance with the Helsinki Declaration and was approved by the Institutional Review Boards of the University of North Carolina at Chapel Hill, Durham Veterans Affairs Medical Center, East Carolina University, and Duke University Health System.
Discussion: This culturally enhanced pain CST program could have a substantial impact on outcomes for African Americans with OA and may be a key strategy in the reduction of racial health disparities.Funded by Patient-Centered Outcomes Research Institute (PCORI) Award (AD-1408-19519)
Pain Coping Skills Training for African Americans With Osteoarthritis Study: Baseline Participant Characteristics and Comparison to Prior Studies
Background: The Pain Coping Skills Training for African Americans with OsteoaRTthritis (STAART) trial is examining the effectiveness of a culturally enhanced pain coping skills training (CST) program for African Americans with osteoarthritis (OA). This disparities-focused trial aimed to reach a population with greater symptom severity and risk factors for poor pain-related outcomes than previous studies. This paper compares characteristics of STAART participants with prior studies of CST or cognitive behavioral therapy (CBT)-informed training in pain coping strategies for OA.
Methods: A literature search identified 10 prior trials of pain CST or CBT-informed pain coping training among individuals with OA. We descriptively compared characteristics of STAART participants with other studies, in 3 domains of the National Institutes of Minority Health and Health Disparities' Research Framework: Sociocultural Environment (e.g., age, education, marital status), Biological Vulnerability and Mechanisms (e.g, pain and function, body mass index), and Health Behaviors and Coping (e.g., pain catastrophizing). Means and standard deviations (SDs) or proportions were calculated for STAART participants and extracted from published manuscripts for comparator studies.
Results: The mean age of STAART participants, 59 years (SD = 10.3), was lower than 9 of 10 comparator studies; the proportion of individuals with some education beyond high school, 75%, was comparable to comparator studies (61-86%); and the proportion of individuals who are married or living with a partner, 42%, was lower than comparator studies (62-66%). Comparator studies had less than about 1/3 African American participants. Mean scores on the Western Ontario and McMaster Universities Osteoarthritis Index pain and function scales were higher (worse) for STAART participants than for other studies, and mean body mass index of STAART participants, 35.2 kg/m2 (SD = 8.2), was higher than all other studies (30-34 kg/m2). STAART participants' mean score on the Pain Catastrophizing scale, 19.8 (SD = 12.3), was higher (worse) than other studies reporting this measure (7-17).
Conclusions: Compared with prior studies with predominantly white samples, STAART participants have worse pain and function and more risk factors for negative pain-related outcomes across several domains. Given STAART participants' high mean pain catastrophizing scores, this sample may particularly benefit from the CST intervention approach
Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms
Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS. Here, we outline mechanisms for how males and females can evolve differences in POLS traits and in how such traits can covary differently despite constraints resulting from a shared genome. We review the current knowledge of the genetic basis of POLS traits and suggest candidate genes and pathways for future studies. Pleiotropic effects may govern many of the genetic correlations, but little is still known about the mechanisms involved in trade-offs between current and future reproduction and their integration with behavioral variation. We highlight the importance of metabolic and hormonal pathways in mediating sex differences in POLS traits; however, there is still a shortage of studies that test for sex specificity in molecular effects and their evolutionary causes. Considering whether and how sexual dimorphism evolves in POLS traits provides a more holistic framework to understand how behavioral variation is integrated with life histories and physiology, and we call for studies that focus on examining the sex-specific genetic architecture of this integration
The United States COVID-19 Forecast Hub dataset
Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages
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