689 research outputs found
Stacks and D-Brane Bundles
In this paper we describe explicitly how the twisted ``bundles'' on a D-brane
worldvolume in the presence of a nontrivial B field, can be understood in terms
of sheaves on stacks. We also take this opportunity to provide the physics
community with a readable introduction to stacks and generalized spaces.Comment: 24 pages, LaTeX; v2: references adde
Palmoplantar keratoderma along with neuromuscular and metabolic phenotypes in Slurp1-deficient mice.
Mutations in SLURP1 cause mal de Meleda, a rare palmoplantar keratoderma (PPK). SLURP1 is a secreted protein that is expressed highly in keratinocytes but has also been identified elsewhere (e.g., spinal cord neurons). Here, we examined Slurp1-deficient mice (Slurp1(-/-)) created by replacing exon 2 with β-gal and neo cassettes. Slurp1(-/-) mice developed severe PPK characterized by increased keratinocyte proliferation, an accumulation of lipid droplets in the stratum corneum, and a water barrier defect. In addition, Slurp1(-/-) mice exhibited reduced adiposity, protection from obesity on a high-fat diet, low plasma lipid levels, and a neuromuscular abnormality (hind-limb clasping). Initially, it was unclear whether the metabolic and neuromuscular phenotypes were due to Slurp1 deficiency, because we found that the targeted Slurp1 mutation reduced the expression of several neighboring genes (e.g., Slurp2, Lypd2). We therefore created a new line of knockout mice (Slurp1X(-/-) mice) with a simple nonsense mutation in exon 2. The Slurp1X mutation did not reduce the expression of adjacent genes, but Slurp1X(-/-) mice exhibited all of the phenotypes observed in the original line of knockout mice. Thus, Slurp1 deficiency in mice elicits metabolic and neuromuscular abnormalities in addition to PPK
Do Girls and Boys Perceive Themselves as Equally Engaged in School? The Results of an International Study from 12 Countries
This study examined gender differences in student engagement and academic
performance in school. Participants included 3420 students (7th, 8th, and 9th
graders) from Austria, Canada, China, Cyprus, Estonia, Greece, Malta, Portugal,
Romania, South Korea, the United Kingdom, and the United States. The results
indicated that, compared to boys, girls reported higher levels of engagement in
school andwere rated higher by their teachers in academic performance. Student
engagement accounted for gender differences in academic performance, but
gender did not moderate the associations among student engagement, academic
performance, or contextual supports. Analysis of multiple-group structural
equation modeling revealed that perceptions of teacher support and parent
support, but not peer support, were related indirectly to academic performance
through student engagement. This partial mediation model was invariant across
gender. The findings from this study enhance the understanding about the
contextual and personal factors associated with girls' and boys' academic
performance around the world
SN2013fs and SN2013fr: Exploring the circumstellar-material diversity in Type II supernovae
We present photometry and spectroscopy of SN2013fs and SN2013fr in the first
100 days post-explosion. Both objects showed transient, relatively narrow
H emission lines characteristic of SNeIIn, but later resembled normal
SNeII-P or SNeII-L, indicative of fleeting interaction with circumstellar
material (CSM). SN2013fs was discovered within 8hr of explosion. Its light
curve exhibits a plateau, with spectra revealing strong CSM interaction at
early times. It is a less luminous version of the transitional SNIIn PTF11iqb,
further demonstrating a continuum of CSM interaction intensity between SNeII-P
and IIn. It requires dense CSM within 6.510~cm of the
progenitor, from a phase of advanced pre-SN mass loss shortly before explosion.
Spectropolarimetry of SN2013fs shows little continuum polarization, but
noticeable line polarization during the plateau phase. SN2013fr morphed from a
SNIIn at early times to a SNII-L. After the first epoch its narrow lines
probably arose from host-galaxy emission, but the bright, narrow H
emission at early times may be intrinsic. As for SN2013fs, this would point to
a short-lived phase of strong CSM interaction if proven to be intrinsic,
suggesting a continuum between SNeIIn and II-L. It is a low-velocity SNII-L,
like SN2009kr but more luminous. SN2013fr also developed an IR excess at later
times, due to warm CSM dust that require a more sustained phase of strong
pre-SN mass loss.Comment: MNRAS accepted. 28 pages, 23 figures, 8 table
Evaluating implementation effectiveness and sustainability of a maternity waiting homes intervention to improve access to safe delivery in rural Zambia: A mixed-methods protocol
Background: In low-income countries such as Zambia, where maternal mortality rates are persistently high, maternity waiting homes (MWHs) represent one potential strategy to improve access to safe delivery, especially for women living in remote areas. The Maternity Homes Access in Zambia project (MAHMAZ) is evaluating the impact of a MWH model on women’s access to safe delivery in rural Zambia. There is a growing need to understand not only the effectiveness of interventions but also the effectiveness of their implementation in order to appropriately interpret outcomes. There is little evidence to guide effective implementation of MWH for both immediate uptake and to promote sustainability in this context. This protocol describes a study that aims to investigate the effectiveness of the implementation of MAHMAZ by not only documenting fidelity but also identifying factors that influence implementation success and affect longer-term sustainability.
Methods: This study will use mixed methods to evaluate the implementation effectiveness and sustainability of the MAHMAZ intervention. In our study, “implementation effectiveness” means to expand beyond measuring fidelity to the MWH model and includes assessing both the adoption and uptake of the model and identifying those factors that facilitate or inhibit uptake. Sustainability is defined as the routine implementation of an intervention after external support has ended. Quantitative methods include extracting data from existing records at the MWHs and health facilities to analyze patterns of utilization, and conducting a routine health facility assessment to determine facility-level factors that may influence MWH implementation and woman-level outcomes. We will also conduct an experience survey with MWH users and apply a checklist to assess fidelity to the MWH model. Qualitative methods include in-depth interviews and focus group discussions with MWH users, community members and other stakeholders. Qualitative data will be analyzed using an integrated framework drawing constructs from the Consolidated Framework for Implementation Research and the Conceptual Framework for Sustainability.
Discussion: The findings from this evaluation will be shared with policymakers formulating policy affecting the implementation of MWH and may be used as evidence for programmatic decisions by the government and supporting agencies in deciding to take this model to scale
Out-of-pocket expenditure for home and facility based delivery among rural women in Zambia: a mixed-methods, cross-sectional study
Purpose: Out-of-pocket expenses associated with facility-based delivery are a well-known barrier to health care access. However, there is extremely limited contemporary information on delivery-related household out-of-pocket expenditure in sub-Saharan Africa. We assess the financial burden of delivery for the most remote Zambian women and compare differences between delivery locations (primary health center, hospital, or home).
Methods: We conducted household surveys and in-depth interviews among randomly selected remote Zambian women who delivered a baby within the last 13 months. Women reported expenditures for their most-recent delivery for delivery supplies, transportation, and baby clothes, among others. Expenditures were converted to US dollars for analysis.
Results: Of 2280 women sampled, 2223 (97.5%) reported spending money on their delivery. Nearly all respondents in the sample (95.9%) spent money on baby clothes/blanket, while over 80% purchased delivery supplies such as disinfectant or cord clamps, and a third spent on transportation. Women reported spending a mean of USD28.76 on their delivery, with baby clothes/blanket (USD21.46) being the main expenditure and delivery supplies (USD3.81) making up much of the remainder. Compared to women who delivered at home, women who delivered at a primary health center spent nearly USD4 (p\u3c0.001) more for their delivery, while women who delivered at a level 1 or level 2 hospital spent over USD7.50 (p\u3c0.001) more for delivery.
Conclusion: These expenses account for approximately one third of the monthly household income of the poorest Zambian households. While the abolition of user fees has reduced the direct costs of delivering at a health facility for the poorest members of society, remote Zambian women still face high out-of-pocket expenses in the form of delivery supplies that facilities should provide as well as unofficial policies/norms requiring women to bring new baby clothes/blanket to a facility-based delivery. Future programs that target these expenses may increase access to facility-based delivery
Psychological distress and quality of life in lung cancer: The role of health-related stigma, illness appraisals and social constraints
Psycho-Oncology Published by John Wiley & Sons Ltd. Objective Health-related stigma is associated with negative psychological and quality of life outcomes in lung cancer patients. This study describes the impact of stigma on lung cancer patients' psychological distress and quality of life and explores the role of social constraints and illness appraisal as mediators of effect. Methods A self-administered cross-sectional survey examined psychological distress and quality of life in 151 people (59% response rate) diagnosed with lung cancer from Queensland and New South Wales. Health-related stigma, social constraints and illness appraisals were assessed as predictors of adjustment outcomes. Results Forty-nine percent of patients reported elevated anxiety; 41% were depressed; and 51% had high global distress. Health-related stigma was significantly related to global psychological distress and quality of life with greater stigma and shame related to poorer outcomes. These effects were mediated by illness appraisals and social constraints. Conclusions Health-related stigma appears to contribute to poorer adjustment by constraining interpersonal discussions about cancer and heightening feelings of threat. There is a need for the development and evaluation of interventions to ameliorate the negative effects of health-related stigma among lung cancer patients
Consumer Connectivity in a Complex, Technology-Enabled, and Mobile-Oriented World with Smart Products
Today’s consumers are immersed in a vast and complex array of networks. Each network features an interconnected mesh of people and firms, and now, with the rise of the Internet of Things (IoT), also objects. Technology (particularly mobile devices) enables such connections, and facilitates many kinds of interactions in these networks - from transactions, to social information sharing, to people interfacing with connected devices (e.g., wearable technology). We introduce the POP-framework, discuss how People, Objects and the Physical world interconnect with each other and how it results in an increasing amount of connected data, and briefly summarize existing knowledge on these inter-connections. We also provide an agenda for future research focused on examining potential impact of IoT and smart products on consumer behavior and firm strategies
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