Identifying Optimal Methods for Addressing Confounding Bias When Estimating the Effects of State-Level Policies

Background: Policy evaluation studies that assess how state-level policies affect health-related outcomes are foundational to health and social policy research. The relative ability of newer analytic methods to address confounding, a key source of bias in observational studies, has not been closely examined. Methods: We conducted a simulation study to examine how differing magnitudes of confounding affected the performance of four methods used for policy evaluations: (1) the two-way fixed effects (TWFE) difference-in-differences (DID) model; (2) a one-period lagged autoregressive (AR) model; (3) augmented synthetic control method (ASCM); and (4) the doubly robust DID approach with multiple time periods from Callaway-Sant'Anna (CSA). We simulated our data to have staggered policy adoption and multiple confounding scenarios (i.e., varying the magnitude and nature of confounding relationships). Results: Bias increased for each method: (1) as confounding magnitude increases; (2) when confounding is generated with respect to prior outcome trends (rather than levels), and (3) when confounding associations are nonlinear (rather than linear). The AR and ASCM have notably lower root mean squared error than the TWFE model and CSA approach for all scenarios; the exception is nonlinear confounding by prior trends, where CSA excels. Coverage rates are unreasonably high for ASCM (e.g., 100%), reflecting large model-based standard errors and wide confidence intervals in practice. Conclusions: Our simulation study indicated that no single method consistently outperforms the others. But a researcher's toolkit should include all methodological options. Our simulations and associated R package can help researchers choose the most appropriate approach for their data.Comment: 4 figures, 1 table, supplemental material including cod

Adubos verdes: alternativa para agricultores familiares no nordeste paraense

No Estado do Pará, a busca por estratégias acessíveis e de baixo custo para a adubação dos cultivos e controle de plantas espontâneas são de extrema importância para o desenvolvimento da agricultura familiar. Visando construir e consolidar tais estratégias foi desenvolvido o presenta trabalho no ano de 2014, no nordeste paraense no município de Capitão Poço/Pará/Brasil. Inicialmente foram realizadas oficinas, palestras e dias de campo para sensibilização dos agricultores. Em seguida foi proposto à implantação de uma área demonstrativa com algumas espécies de leguminosas. Ao final do processo de pesquisa/ação participativa, este trabalho teve por objetivo avaliar a construção e adoção destas estratégias junto aos agricultores assentados. Como resultado, realizou-se o plantio das leguminosas em consórcio com espécies frutíferas regionais, e a visualização de bons resultados com o plantio dos adubos verdes. De acordo com relatos, estes diminuíram o número de capinas, reduziram a mão de obra nos manejos e consequentemente baixaram o custo de produção.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Adubos verdes: alternativa para agricultores familiares no nordeste paraense

No Estado do Pará, a busca por estratégias acessíveis e de baixo custo para a adubação dos cultivos e controle de plantas espontâneas são de extrema importância para o desenvolvimento da agricultura familiar. Visando construir e consolidar tais estratégias foi desenvolvido o presenta trabalho no ano de 2014, no nordeste paraense no município de Capitão Poço/Pará/Brasil. Inicialmente foram realizadas oficinas, palestras e dias de campo para sensibilização dos agricultores. Em seguida foi proposto à implantação de uma área demonstrativa com algumas espécies de leguminosas. Ao final do processo de pesquisa/ação participativa, este trabalho teve por objetivo avaliar a construção e adoção destas estratégias junto aos agricultores assentados. Como resultado, realizou-se o plantio das leguminosas em consórcio com espécies frutíferas regionais, e a visualização de bons resultados com o plantio dos adubos verdes. De acordo com relatos, estes diminuíram o número de capinas, reduziram a mão de obra nos manejos e consequentemente baixaram o custo de produção.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

Adubos verdes: alternativa para agricultores familiares no nordeste paraense

No Estado do Pará, a busca por estratégias acessíveis e de baixo custo para a adubação dos cultivos e controle de plantas espontâneas são de extrema importância para o desenvolvimento da agricultura familiar. Visando construir e consolidar tais estratégias foi desenvolvido o presenta trabalho no ano de 2014, no nordeste paraense no município de Capitão Poço/Pará/Brasil. Inicialmente foram realizadas oficinas, palestras e dias de campo para sensibilização dos agricultores. Em seguida foi proposto à implantação de uma área demonstrativa com algumas espécies de leguminosas. Ao final do processo de pesquisa/ação participativa, este trabalho teve por objetivo avaliar a construção e adoção destas estratégias junto aos agricultores assentados. Como resultado, realizou-se o plantio das leguminosas em consórcio com espécies frutíferas regionais, e a visualização de bons resultados com o plantio dos adubos verdes. De acordo com relatos, estes diminuíram o número de capinas, reduziram a mão de obra nos manejos e consequentemente baixaram o custo de produção.Eje: B1 Sistemas de producción de base agroecológica (Relatos de experiencias).Facultad de Ciencias Agrarias y Forestale

The Fifth Data Release of the Sloan Digital Sky Survey

This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky Survey (SDSS). DR5 includes all survey quality data taken through June 2005 and represents the completion of the SDSS-I project (whose successor, SDSS-II will continue through mid-2008). It includes five-band photometric data for 217 million objects selected over 8000 square degrees, and 1,048,960 spectra of galaxies, quasars, and stars selected from 5713 square degrees of that imaging data. These numbers represent a roughly 20% increment over those of the Fourth Data Release; all the data from previous data releases are included in the present release. In addition to "standard" SDSS observations, DR5 includes repeat scans of the southern equatorial stripe, imaging scans across M31 and the core of the Perseus cluster of galaxies, and the first spectroscopic data from SEGUE, a survey to explore the kinematics and chemical evolution of the Galaxy. The catalog database incorporates several new features, including photometric redshifts of galaxies, tables of matched objects in overlap regions of the imaging survey, and tools that allow precise computations of survey geometry for statistical investigations.Comment: ApJ Supp, in press, October 2007. This paper describes DR5. The SDSS Sixth Data Release (DR6) is now public, available from http://www.sdss.or

Feasibility of large-scale deployment of multiple wearable sensors in Parkinson’s disease

Wearable devices can capture objective day-to-day data about Parkinson’s Disease (PD). This study aims to assess the feasibility of implementing wearable technology to collect data from multiple sensors during the daily lives of PD patients. The Parkinson@home study is an observational, two-cohort (North America, NAM; The Netherlands, NL) study. To recruit participants, different strategies were used between sites. Main enrolment criteria were self-reported diagnosis of PD, possession of a smartphone and age ≥18 years. Participants used the Fox Wearable Companion app on a smartwatch and smartphone for a minimum of 6 weeks (NAM) or 13 weeks (NL). Sensor-derived measures estimated information about movement. Additionally, medication intake and symptoms were collected via self-reports in the app. A total of 953 participants were included (NL: 304, NAM: 649). Enrolment rate was 88% in the NL (n = 304) and 51% (n = 649) in NAM. Overall, 84% (n = 805) of participants contributed sensor data. Participants were compliant for 68% (16.3 hours/participant/day) of the study period in NL and for 62% (14.8 hours/participant/day) in NAM. Daily accelerometer data collection decreased 23% in the NL after 13 weeks, and 27% in NAM after 6 weeks. Data contribution was not affected by demographics, clinical characteristics or attitude towards technology, but was by the platform usability score in the NL (χ2 (2) = 32.014, p<0.001), and self-reported depression in NAM (χ2(2) = 6.397, p = .04). The Parkinson@home study shows that it is feasible to collect objective data using multiple wearable sensors in PD during daily life in a large cohort

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

Freezing of gait and fall detection in Parkinson’s disease using wearable sensors:a systematic review

Despite the large number of studies that have investigated the use of wearable sensors to detect gait disturbances such as Freezing of gait (FOG) and falls, there is little consensus regarding appropriate methodologies for how to optimally apply such devices. Here, an overview of the use of wearable systems to assess FOG and falls in Parkinson’s disease (PD) and validation performance is presented. A systematic search in the PubMed and Web of Science databases was performed using a group of concept key words. The final search was performed in January 2017, and articles were selected based upon a set of eligibility criteria. In total, 27 articles were selected. Of those, 23 related to FOG and 4 to falls. FOG studies were performed in either laboratory or home settings, with sample sizes ranging from 1 PD up to 48 PD presenting Hoehn and Yahr stage from 2 to 4. The shin was the most common sensor location and accelerometer was the most frequently used sensor type. Validity measures ranged from 73–100% for sensitivity and 67–100% for specificity. Falls and fall risk studies were all home-based, including samples sizes of 1 PD up to 107 PD, mostly using one sensor containing accelerometers, worn at various body locations. Despite the promising validation initiatives reported in these studies, they were all performed in relatively small sample sizes, and there was a significant variability in outcomes measured and results reported. Given these limitations, the validation of sensor-derived assessments of PD features would benefit from more focused research efforts, increased collaboration among researchers, aligning data collection protocols, and sharing data sets

SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANÁ RIVER BASIN, BRAZIL

Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated