784 research outputs found
Weighted Estimates for the Bergman and Szeg\H{o} Projections on Strongly Pseudoconvex Domains with Near Minimal Smoothness
We prove the weighted regularity of the ordinary Bergman and
Cauchy-Szeg\H{o} projections on strongly pseudoconvex domains in
with near minimal smoothness for appropriate generalizations of
the classes. In particular, the Muckenhoupt type condition
is expressed relative to balls in a quasi-metric that arises as a space of
homogeneous type on either the interior or the boundary of the domain .Comment: 40 pages, introduction reorganized and some typos correcte
A B\'{e}koll\`{e}-Bonami Class of Weights for Certain Pseudoconvex Domains
We prove the weighted regularity of the ordinary Bergman projection on
certain pseudoconvex domains where the weight belongs to an appropriate
generalization of the B\'{e}koll\`{e}-Bonami class. The main tools used are
estimates on the Bergman kernel obtained by McNeal and B\'{e}koll\`{e}'s
original approach of proving a good-lambda inequality.Comment: 24 page
Bekoll\'e-Bonami estimates on some pseudoconvex domains
We establish a weighted norm estimate for the Bergman projection for a
class of pseudoconvex domains. We obtain an upper bound for the weighted
norm when the domain is, for example, a bounded smooth strictly pseudoconvex
domain, a pseudoconvex domain of finite type in , a convex domain
of finite type in , or a decoupled domain of finite type in
. The upper bound is related to the Bekoll\'e-Bonami constant and
is sharp. When the domain is smooth, bounded, and strictly pseudoconvex, we
also obtain a lower bound for the weighted norm.Comment: 28 pages. An application to the weak-type estimate is added as a new
sectio
Dental students’ perceptions of learning communication skills in a forum theatre-style teaching session on breaking bad news
Introduction: Communication skills are an integral component of dental undergraduate education. Due to the complex nature of these skills, didactic teaching methods used in other educational contexts can be limited. Interactive and participative methods rooted in modern adult learning theories, such as Forum Theatre, may be more effective in the teaching of communication skills. Aim: To explore the usefulness of Forum Theatre in teaching clinical undergraduate dental students how to break bad news to their patients.Methods: A purposive sample of 4th-year undergraduate dental students was invited to participate. An evaluation questionnaire was given to the students and collected after the Forum Theatre interactive session. Participants were asked to provide self-reported accounts on the most and least useful parts of the session, as well as the most important learning outcome. Usefulness of the session in clinical work, increasing confidence and ability in breaking bad news, were evaluated via a 5-point Likert-scale type question. Qualitative data were analysed using Framework Analysis to explore the themes found in the open-text component. Descriptive statistics were used to analyse the Likert-scale items.Results: One hundred and fifteen completed questionnaires were collected from the 2015 and 2016 classes. Most students gave the Forum Theatre session a rating of 3 or above on a 5-point Likert scale; indicating that they found it useful. Qualitative results also showed that most participants liked the teaching session thanks to its interactive nature, the use of actors and the input of the facilitators. The majority of students showed preference towards smaller groups which give everyone equal opportunity to participate without unnecessary repetition.Conclusion: The results seem to confirm previous findings. Students rated their learning experience involving Forum Theatre favourably. Smaller groups and trained facilitators are required for the success of this teaching method. Further research is needed to assess the long-term educational benefits of Forum Theatre.</p
Direct Measurement of Supra-Physiological Levels of Ascorbate in Plasma using a Nanophotometer
High dose intravenously administered vitamin C (ascorbate) is currently being tested in clinical trials as an adjuvant to current standard of care therapies in a variety of cancers. Intravenous infusion is used with a goal to achieve supraphysiological ascorbate concentrations in blood of at least 20 mM, 300 to 500 times normal healthy concentrations (0.04-0.08 mM). These trials need quick and easy access to information on the levels of ascorbate achieved in the blood to make clinical decisions. Previous methods that quantify ascorbate levels in blood require extensive preparation, time, and materials that may not always be present in clinical settings. We developed a new approach to meet this need using direct UV spectroscopy with a nanophotometer. The only preparation required is centrifugation of whole blood to separate the red blood cells from plasma. No more than 3 microliters of plasma are needed; the approach can determine the concentration of ascorbate in the range of 3 – 35 mM; the method is fast and efficient. This approach has already been deployed to gather this information in a clinical trial with lung cancer patients
Decoupling Inflation From the String Scale
When Inflation is embedded in a fundamental theory, such as string theory, it
typically begins when the Universe is already substantially larger than the
fundamental scale [such as the one defined by the string length scale]. This is
naturally explained by postulating a pre-inflationary era, during which the
size of the Universe grew from the fundamental scale to the initial
inflationary scale. The problem then arises of maintaining the [presumed]
initial spatial homogeneity throughout this era, so that, when it terminates,
Inflation is able to begin in its potential-dominated state. Linde has proposed
that a spacetime with compact negatively curved spatial sections can achieve
this, by means of chaotic mixing. Such a compactification will however lead to
a Casimir energy, which can lead to effects that defeat the purpose unless the
coupling to gravity is suppressed. We estimate the value of this coupling
required by the proposal, and use it to show that the pre-inflationary
spacetime is stable, despite the violation of the Null Energy Condition
entailed by the Casimir energy.Comment: 24 pages, 5 eps figures, references added, stylistic changes, version
to appear in Classical and Quantum Gravit
Achieving sustainable aquaculture: Historical and current perspectives and future needs and challenges
Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs
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Depression, Stressful Life Events, and the Impact of Variation in the Serotonin Transporter: Findings from the National Longitudinal Study of Adolescent to Adult Health (Add Health)
BackgroundThe low transcriptionally efficient short-allele of the 5HTTLPR serotonin transporter polymorphism has been implicated to moderate the relationship between the experience of stressful life events (SLEs) and depression. Despite numerous attempts at replicating this observation, results remain inconclusive.MethodsWe examined this relationship in young-adult Non-Hispanic white males and females between the ages of 22 and 26 (n = 4724) participating in the National Longitudinal Study of Adolescent to Adult Health (Add Health) with follow-up information every six years since 1995.ResultsLinear and logistic regression models, corrected for multiple testing, indicated that carriers of one or more of the S-alleles were more sensitive to stress than those with two L-alleles and at a higher risk for depression. This relationship behaved in a dose-response manner such that the risk for depression was greatest among those who reported experiencing higher numbers of SLEs. In post-hoc analyses we were not able to replicate an interaction effect for suicide ideation but did find suggestive evidence that the effects of SLEs and 5HTTLPR on suicide ideation differed for males and females. There were no effects of childhood maltreatment.DiscussionOur results provide partial support for the original hypothesis that 5-HTTLPR genotype interacts with the experience of stressful life events in the etiology of depression during young adulthood. However, even with this large sample, and a carefully constructed a priori analysis plan, the results were still not definitive. For the purposes of replication, characterizing the 5HTTLPR in other large data sets with extensive environmental and depression measures is needed
Neurodevelopmental Correlates of True and False Recognition
The Deese/Roediger–McDermott (DRM) false-memory effect has been extensively documented in psychological research. People falsely recognize critical lures or nonstudied items that are semantically associated with studied items. Behavioral research has provided evidence for age-related increases in the DRM false-recognition effect. The present event-related functional magnetic resonance imaging study was aimed at investigating neurodevelopmental changes in brain regions associated with true- and false-memory recognition in 8-year olds, 12-year olds, and adults. Relative to 8-year olds, adults correctly endorsed more studied items as “old” but also mistakenly endorsed more critical lures. Age-related increases in recollection were associated with changes in the medial temporal lobe (MTL) activation profile. Additionally, age-related increases in false alarms (FAs) to semantically related lures were associated with changes in the activation profile of left ventrolateral prefrontal cortex, a region associated with semantic processing. Additional regions exhibiting age-related changes include posterior parietal and anterior prefrontal cortices. In summary, concomitant changes in the MTL, prefrontal cortex, and parietal cortex underlie developmental increases in true and false recognition during childhood and adolescence
Extracellular superoxide dismutase (SOD3) regulates oxidative stress at the vitreoretinal interface
Oxidative stress is a pathogenic feature in vitreoretinal disease. However, the ability of the inner retina to manage metabolic waste and oxidative stress is unknown. Proteomic analysis of antioxidants in the human vitreous, the extracellular matrix opposing the inner retina, identified superoxide dismutase-3 (SOD3) that localized to a unique matrix structure in the vitreous base and cortex. To determine the role of SOD3, Sod3-/- mice underwent histological and clinical phenotyping. Although the eyes were structurally normal, at the vitreoretinal interface Sod3-/- mice demonstrated higher levels of 3-nitrotyrosine, a key marker of oxidative stress. Pattern electroretinography also showed physiological signaling abnormalities within the inner retina. Vitreous biopsies and epiretinal membranes collected from patients with diabetic vitreoretinopathy (DVR) and a mouse model of DVR showed significantly higher levels of nitrates and/or 3-nitrotyrosine oxidative stress biomarkers suggestive of SOD3 dysfunction. This study analyzes the molecular pathways that regulate oxidative stress in human vitreous substructures. The absence or dysregulation of the SOD3 antioxidant at the vitreous base and cortex results in increased oxidative stress and tissue damage to the inner retina, which may underlie DVR pathogenesis and other vitreoretinal diseases
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