4,311 research outputs found
Karen Rothenberg’s (Not So) Secret Roles and Contributions at the U.S. National Institutes of Health
D3 Brane Action and Fermion Zero Modes in Presence of Background Flux
We derive the fermion bilinear terms in the world volume action for a D3
brane in the presence of background flux. In six-dimensional compactifications
non-perturbative corrections to the superpotential can arise from an Euclidean
D3-brane instanton wrapping a divisor in the internal space. The bilinear terms
give rise to fermion masses and are important in determining these corrections.
We find that the three-form flux generically breaks a U(1) subgroup of the
structure group of the normal bundle of the divisor. In an example of
compactification on T^6/Z_2, six of the sixteen zero modes originally present
are lifted by the flux.Comment: Important factor of ``i'' was overlooked in Euclidean continuation of
WZ term. This changes the count of zero-modes in the T^6/Z_2 example. Main
result stays unchanged. We thank Bergshoeff, Kallosh, Kashani-Poor, Sorokin
and Tomasiello for pointing this ou
CT virtual intravascular endoscopy in the follow-up of endoluminal fenestrated stent grafts
Purpose: To investigate the potential value of CT virtual intravascular endoscopy in the follow-up of patients with abdominal aortic aneurysms treated with endoluminal fenestrated stent grafts.Methods and Materials: Eight patients with abdominal aortic aneurysms unsuitable for open surgery or conventional endovascular repair undergoing fenestrated stent grafts were included in the study. Both pre-and post-fenestration multislice CT data were collected in these patients and used for generation of virtual intravascular endoscopy images of aortic ostium and endovascular stents. Virtual endoscopy images were compared with conventional axial CT and multiplanar images with the aim of identifying the appearances of the endoluminal stents. The length of endoluminal stents that protruded into the aortic lumen was measured on virtual endoscopy images.Results: Variable fenestrations were deployed in 27 aortic branches with scallop fenestration implanted in 5 aortic ostia, large fenestration in 7 aortic ostia and small fenestration in 15 renal ostia, respectively. All of the fenestrated branches remained patent. Virtual endoscopy was superior to conventional 2D images in the visualization of configuration of endovascular stents. Most of the stents (68%) were found to be circular visualized on virtual endoscopy images, while the remaining stents were irregular in terms of endoluminal appearances. 95% of these stents were shown to protrude into the lumen with length less than 7.0 mm. There is no significant difference of the diameters of aortic ostia between pre-and post- fenestration (p>0.05).Conclusion: Our preliminary study shows that virtual intravascular endoscopy could be a valuable technique to follow-up patients treated with endoluminal fenestrated stent grafts
Upending the Social Ecological Model to Guide Health Promotion Efforts Toward Policy and Environmental Change
Efforts to change policies and the environments in which people live, work, and play have gained increasing attention over the past several decades. Yet health promotion frameworks that illustrate the complex processes that produce health-enhancing structural changes are limited. Building on the experiences of health educators, community activists, and community-based researchers described in this supplement and elsewhere, as well as several political, social, and behavioral science theories, we propose a new framework to organize our thinking about producing policy, environmental, and other structural changes. We build on the social ecological model, a framework widely employed in public health research and practice, by turning it inside out, placing health-related and other social policies and environments at the center, and conceptualizing the ways in which individuals, their social networks, and organized groups produce a community context that fosters healthy policy and environmental development. We conclude by describing how health promotion practitioners and researchers can foster structural change by (1) conveying the health and social relevance of policy and environmental change initiatives, (2) building partnerships to support them, and (3) promoting more equitable distributions of the resources necessary for people to meet their daily needs, control their lives, and freely participate in the public sphere
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The organizational social context of mental health services and clinician attitudes toward evidence-based practice: a United States national study.
UnlabelledABSTBACKGROUND: Evidence-based practices have not been routinely adopted in community mental health organizations despite the support of scientific evidence and in some cases even legislative or regulatory action. We examined the association of clinician attitudes toward evidence-based practice with organizational culture, climate, and other characteristics in a nationally representative sample of mental health organizations in the United States.MethodsIn-person, group-administered surveys were conducted with a sample of 1,112 mental health service providers in a nationwide sample of 100 mental health service institutions in 26 states in the United States. The study examines these associations with a two-level Hierarchical Linear Modeling (HLM) analysis of responses to the Evidence-Based Practice Attitude Scale (EBPAS) at the individual clinician level as a function of the Organizational Social Context (OSC) measure at the organizational level, controlling for other organization and clinician characteristics.ResultsWe found that more proficient organizational cultures and more engaged and less stressful organizational climates were associated with positive clinician attitudes toward adopting evidence-based practice.ConclusionsThe findings suggest that organizational intervention strategies for improving the organizational social context of mental health services may contribute to the success of evidence-based practice dissemination and implementation efforts by influencing clinician attitudes
D-terms and D-strings in open string models
We study the Fayet-Iliopoulos (FI) D-terms on D-branes in type II Calabi-Yau
backgrounds. We provide a simple worldsheet proof of the fact that, at tree
level, these terms only couple to scalars in closed string hypermultiplets. At
the one-loop level, the D-terms get corrections only if the gauge group has an
anomalous spectrum, with the anomaly cancelled by a Green-Schwarz mechanism. We
study the local type IIA model of D6-branes at SU(3) angles and show that, as
in field theory, the one-loop correction suffers from a quadratic divergence in
the open string channel. By studying the closed string channel, we show that
this divergence is related to a closed string tadpole, and is cancelled when
the tadpole is cancelled. Next, we study the cosmic strings that arise in the
supersymmetric phases of these systems in light of recent work of Dvali et. al.
In the type IIA intersecting D6-brane examples, we identify the D-term strings
as D4-branes ending on the D6-branes. Finally, we use N=1 dualities to relate
these results to previous work on the FI D-term of heterotic strings.Comment: 29 pages, 5 figures; v2: improved referencin
A Nonword Repetition Task for Speakers with Misarticulations: The Syllable Repetition Task (SRT)
Purpose. Conceptual and methodological confounds occur when non(sense) repetition tasks are administered to speakers who do not have the target speech sounds in their phonetic inventories or who habitually misarticulate targeted speech sounds. We describe a nonword repetition task, the Syllable Repetiton Task (SRT) that eliminates this confound and report findings from three validity studies. Method. Ninety-five preschool children with Speech Delay and 63 with Typical Speech, completed an assessment battery that included the Nonword Repetition Task (NRT: Dollaghan & Campbell, 1998) and the SRT. SRT stimuli include only four of the earliest occurring consonants and one early occurring vowel. Results. Study 1 findings indicated that the SRT eliminated the speech confound in nonword testing with speakers who misarticulate. Study 2 findings indicated that the accuracy of the SRT to identify expressive language impairment was comparable to findings for the NRT. Study 3 findings illustrated the SRT’s potential to interrogate speech processing constraints underlying poor nonword repetition accuracy. Results supported both memorial and auditory-perceptual encoding constraints underlying nonword repetition errors in children with speech-language impairment. Conclusion. The SRT appears to be a psychometrically stable and substantively informative nonword repetition task for emerging genetic and other research with speakers who misarticulate
Lessons Learned in the Early Stages of a Community-Academic Partnership to Address Health Disparities in a Rural Community
In rural Georgia, African American men are burdened by chronic health diseases such as cancer, diabetes, and cardiovascular disease. Community-academic partnerships that leverage community-based participatory research (CBPR) principles can facilitate the adaptation and translation of multilevel programs to address chronic disease prevention and management in rural areas. The objective of this study was to explore key components of the CBPR process that bolstered the early stages of a partnership established between rural-residing community leaders and academic partners in Georgia. Qualitative methodology was used to collect and assess data regarding the initial engagement between the community and academic partners. Findings indicate that five components supported initial engagement: utilizing the public service and outreach arm of the university to connect with rural communities; creating synergy around identified community health needs; encouraging community members to provide input into the research design to ensure the research goals reflect community values; enhancing the capacity of community partners; and following the lead of the community. Findings provide insights into how to begin engaging rural communities in the southeast in order to strengthen the adaptation and translation of initiatives to improve cancer, diabetes and cardiovascular disease outcomes
Bulk perturbations of N=2 branes
The evolution of supersymmetric A-type D-branes under the bulk
renormalization group flow between two different N=2 minimal models is studied.
Using the Landau-Ginzburg description we show that a specific set of branes
decouples from the infrared theory, and we make detailed predictions for the
behavior of the remaining branes. The Landau-Ginzburg picture is then checked
against a direct conformal field theory analysis. In particular we construct a
natural index pairing which is preserved by the RG flow, and show that the
branes that decouple have vanishing index with the surviving branes.Comment: 35 pages (30 pages plus title and references), 8 figure
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