1,692 research outputs found

    Flexible epidemiological model for estimates and short-term projections in generalised HIV/AIDS epidemics

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    International audienceObjective UNAIDS and country analysts use a simple infectious disease model, embedded in the Estimation and Projection Package (EPP), to generate annual updates on the global HIV/AIDS epidemic. Our objective was to develop modifications to the current model that improve fit to recently observed prevalence trends across countries. Methods Our proposed alternative to the current EPP approach simplifies the model structure and explicitly models changes in average infection risk over time, operationalised using penalised B-splines in a Bayesian framework. We also present an alternative approach to initiating the epidemic that improves standardisation and efficiency, and add an informative prior distribution for changes in infection risk beyond the last data point that enhances the plausibility of short-term extrapolations. Results The spline-based model produces better fits than the current model to observed prevalence trends in settings that have recently experienced levelling or rising prevalence following a steep decline, such as Uganda and urban Rwanda. The model also predicts a deceleration of the decline in prevalence for countries with recent experience of steady declines, such as Kenya and Zimbabwe. Estimates and projections from our alternative model are comparable to those from the current model where the latter performs well. Conclusions A more flexible epidemiological model that accommodates changing infection risk over time can provide better estimates and short-term projections of HIV/AIDS incidence, prevalence and mortality than the current EPP model. The alternative model specification can be incorporated easily into existing analytical tools that are used to produce updates on the global HIV/AIDS epidemic

    Neonatal cause-of-death estimates for the early and late neonatal periods for 194 countries: 2000-2013.

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    OBJECTIVE: To estimate cause-of-death distributions in the early (0-6 days of age) and late (7-27 days of age) neonatal periods, for 194 countries between 2000 and 2013. METHODS: For 65 countries with high-quality vital registration, we used each country's observed early and late neonatal proportional cause distributions. For the remaining 129 countries, we used multinomial logistic models to estimate these distributions. For countries with low child mortality we used vital registration data as inputs and for countries with high child mortality we used neonatal cause-of-death distribution data from studies in similar settings. We applied cause-specific proportions to neonatal death estimates from the United Nations Inter-agency Group for Child Mortality Estimation, by country and year, to estimate cause-specific risks and numbers of deaths. FINDINGS: Over time, neonatal deaths decreased for most causes. Of the 2.8 million neonatal deaths in 2013, 0.99 million deaths (uncertainty range: 0.70-1.31) were estimated to be caused by preterm birth complications, 0.64 million (uncertainty range: 0.46-0.84) by intrapartum complications and 0.43 million (uncertainty range: 0.22-0.66) by sepsis and other severe infections. Preterm birth (40.8%) and intrapartum complications (27.0%) accounted for most early neonatal deaths while infections caused nearly half of late neonatal deaths. Preterm birth complications were the leading cause of death in all regions of the world. CONCLUSION: The neonatal cause-of-death distribution differs between the early and late periods and varies with neonatal mortality rate level. To reduce neonatal deaths, effective interventions to address these causes must be incorporated into policy decisions

    Encouraging Patient Portal Use in the Patient-Centered Medical Home: Three Stakeholder Perspectives

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    BACKGROUND: Health care organizations are increasingly offering patients access to their electronic medical record and the ability to communicate with their providers through Web-based patient portals, thus playing a prominent role within the patient-centered medical home (PCMH). However, despite enthusiasm, adoption remains low. OBJECTIVE: We examined factors in the PCMH context that may affect efforts to improve enrollment in a patient portal. METHODS: Using a sociotechnical approach, we conducted qualitative, semistructured interviews with patients and providers from 3 primary care clinics and with national leaders from across a large integrated health care system. RESULTS: We gathered perspectives and analyzed data from 4 patient focus groups and one-on-one interviews with 1 provider from each of 3 primary care clinics and 10 program leaders. We found that leaders were focused on marketing in primary care, whereas patients and providers were often already aware of the portal. In contrast, both patients and providers cited administrative and logistical barriers impeding enrollment. Further, although leadership saw the PCMH as the logical place to focus enrollment efforts, providers and patients were more circumspect and expressed concern about how the patient portal would affect their practice and experience of care. Further, some providers expressed ambivalence about patients using the portal. Despite absence of consensus on how and where to encourage portal adoption, there was wide agreement that promoting enrollment was a worthwhile goal. CONCLUSIONS: Patients, clinicians, and national leaders agreed that efforts were needed to increase enrollment in the patient portal. Opinions diverged regarding the suitability of the PCMH and, specifically, the primary care clinic for promoting patient portal enrollment. Policymakers should consider diverse stakeholder perspectives in advance of interventions to increase technology adoption

    Rangelands in a fragmented grass‑dominated landscape are vulnerable to tree invasion from roadsides

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    Roadsides can be vectors for tree invasion within rangelands by bisecting landscapes and facilitating propagule spread to interior habitat. Current invasive tree management in North America’s Great Plains focuses on reducing on-site (i.e., interior habitat) vulnerability through on-site prevention and eradication, but invasive tree management of surrounding areas known to serve as invasion vectors, such as roadsides and public rights-of-ways, is sporadic. We surveyed roadsides for invasive tree propagule sources in a central Great Plains grassland landscape to determine how much of the surrounding landscape is potentially vulnerable to roadside invasion, and by which species, and thereby provide insights into the locations and forms of future landcover change. Invasive tree species were widespread in roadsides. Given modest seed dispersal distances of 100–200 m, our results show that roadsides have potential to serve as major sources of rangeland exposure to tree invasion, compromising up to 44% of rangelands in the study area. Under these dispersal distances, funds spent removing trees on rangeland properties may have little impact on the landscape’s overall vulnerability, due to exposure driven by roadside propagule sources. A key implication from this study is that roadsides, while often neglected from management, represent an important component of integrated management strategies for reducing rangeland vulnerability to tree invasion

    Motion-Sensitive 3-D Optical Coherence Microscope Operating at 1300 nm for the Visualization of Early Frog Development

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    We present 3-dimensional volume-rendered in vivo images of developing embryos of the African clawed frog Xenopus laevis taken with our new en-face-scanning, focus-tracking OCM system at 1300 nm wavelength. Compared to our older instrument which operates at 850 nm, we measure a decrease in the attenuation coefficient by 33%, leading to a substantial improvement in depth penetration. Both instruments have motion-sensitivity capability. By evaluating the fast Fourier transform of the fringe signal, we can produce simultaneously images displaying the fringe amplitude of the backscattered light and images showing the random Brownian motion of the scatterers. We present time-lapse movies of frog gastrulation, an early event during vertebrate embryonic development in which cell movements result in the formation of three distinct layers that later give rise to the major organ systems. We show that the motion-sensitive images reveal features of the different tissue types that are not discernible in the fringe amplitude images. In particular, we observe strong diffusive motion in the vegetal (bottom) part of the frog embryo which we attribute to the Brownian motion of the yolk platelets in the endoderm

    Increasing Capacity for Evaluation of Community-Based Organizations: Lessons from the Ohio Equity Institute

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    Background: Community-based organizations (CBOs) play an important role delivering disease prevention and health promotion activities to address community health needs and improve the health of individuals living in their communities. While CBOs play this important role, evaluation of the services they deliver is hampered by limited infrastructure to systematically collect data from these organizations. To address this gap, we report on a case study of the development of the Ohio Equity Institute (OEI) Data Portal. The OEI is a statewide initiative that supports 65 CBOs across Ohio to deliver 3 evidence-based interventions (ie, CenteringPregnancy, Community Health Workers, and Home Visiting) to address infant mortality in underserved populations. Methods: Employing principles of community-engaged stakeholder research and user-centered design, we conducted Plan-Do-Study-Act cycles, including semistructured interviews with 43 key informants, to improve the development, implementation, and use of the OEI Data Portal. Results: This process identified both technical and implementation challenges, and offered opportunities to make improvements to the data collection system itself as well as to the integration of this system with CBO workflows. These improvements yielded significant gains in terms of the quantity and quality of data submission, ultimately contributing to ongoing outcome evaluation efforts. Conclusion: Our findings provide important insight into the challenges experienced by CBOs when participating in a statewide CBO data evaluation infrastructure development and implementation. As Ohio and other states push to expand collaborations between CBOs and health care organizations, leaders should leverage existing data collection to facilitate a more comprehensive and effective process

    CaMKII Controls Whether Touch Is Painful

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    The sensation of touch is initiated when fast conducting low-threshold mechanoreceptors (Aβ-LTMRs) generate impulses at their terminals in the skin. Plasticity in this system is evident in the process of adaption, in which a period of diminished sensitivity follows prior stimulation. CaMKII is an ideal candidate for mediating activity-dependent plasticity in touch because it shifts into an enhanced activation state after neuronal depolarizations and can thereby reflect past firing history. Here we show that sensory neuron CaMKII autophosphorylation encodes the level of Aβ-LTMR activity in rat models of sensory deprivation (whisker clipping, tail suspension, casting). Blockade of CaMKII signaling limits normal adaptation of action potential generation in Aβ-LTMRs in excised skin. CaMKII activity is also required for natural filtering of impulse trains as they travel through the sensory neuron T-junction in the DRG. Blockade of CaMKII selectively in presynaptic Aβ-LTMRs removes dorsal horn inhibition that otherwise prevents Aβ-LTMR input from activating nociceptive lamina I neurons. Together, these consequences of reduced CaMKII function in Aβ-LTMRs cause low-intensity mechanical stimulation to produce pain behavior. We conclude that, without normal sensory activity to maintain adequate levels of CaMKII function, the touch pathway shifts into a pain system. In the clinical setting, sensory disuse may be a critical factor that enhances and prolongs chronic pain initiated by other conditions. SIGNIFICANCE STATEMENT: The sensation of touch is served by specialized sensory neurons termed low-threshold mechanoreceptors (LTMRs). We examined the role of CaMKII in regulating the function of these neurons. Loss of CaMKII function, such as occurred in rats during sensory deprivation, elevated the generation and propagation of impulses by LTMRs, and altered the spinal cord circuitry in such a way that low-threshold mechanical stimuli produced pain behavior. Because limbs are protected from use during a painful condition, this sensitization of LTMRs may perpetuate pain and prevent functional rehabilitation
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