1,642 research outputs found

    Binding of the Bacillus subtilis LexA protein to the SOS operator

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    The Bacillus subtilis LexA protein represses the SOS response to DNA damage by binding as a dimer to the consensus operator sequence 5′-CGAACN(4)GTTCG-3′. To characterize the requirements for LexA binding to SOS operators, we determined the operator bases needed for site-specific binding as well as the LexA amino acids required for operator recognition. Using mobility shift assays to determine equilibrium constants for B.subtilis LexA binding to recA operator mutants, we found that several single base substitutions within the 14 bp recA operator sequence destabilized binding enough to abolish site-specific binding. Our results show that the AT base pairs at the third and fourth positions from the 5′ end of a 7 bp half-site are essential and that the preferred binding site for a LexA dimer is 5′-CGAACATATGTTCG-3′. Binding studies with LexA mutants, in which the solvent accessible amino acid residues in the putative DNA binding domain were mutated, indicate that Arg-49 and His-46 are essential for binding and that Lys-53 and Ala-48 are also involved in operator recognition. Guided by our mutational analyses as well as hydroxyl radical footprinting studies of the dinC and recA operators we docked a computer model of B.subtilis LexA on the preferred operator sequence in silico. Our model suggests that binding by a LexA dimer involves bending of the DNA helix within the internal 4 bp of the operator

    Perceived Effectiveness, Cost, and Availability of Patient Education Methods and Materials

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    To determine the efficacy of and need for patient education methods and media, a needs assessment was sent to 816 members of the American Association of Diabetes Educators. Respondents (n=325, 40%) included 62% RNs, 36% RDs, 1% other; 62% CDEs. Their mean number of years experience in diabetes education was 8.5, and 99% routinely provided patient education. Respondents indicated that videotapes and slide tapes were the most educationally effective media and books and audiotapes were the least effective. Booklets and videotapes were the most cost-effective and computer-assisted instruction the least effective. While respondents perceived one-to-one counseling, skills training, and diabetes content sessions to be the three most educationally effective methods, support groups and large and small discussion groups were seen as the three most cost-effective educational methods. Among nine potential barriers to quality patient education listed, educators rated lack of third-party reimbursement as a major barrier most frequently and national availability of quality education materials as a barrier least frequently.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68739/2/10.1177_014572179201800207.pd

    Condiciones físico-ambientales en las aulas y desempeño escolar en Colombia

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    Motivated by the need to explore factors related to academic performance beyond those regularly examined, this research analyzes two context variables that have been overlooked and offer inconclusive findings so far: lighting and temperature conditions at schools. To reach this goal, this research uses multilevel models and the OECD's Programme for International Student Assessment (PISA) of 2012 to measure the incidence on mathematics outcomes. Once accounted by characteristics of students and schools, as well as educational processes, it is found that the average score is 15 points lower and the probability of achieving below the basic level of performance is 10 percent higher for students in schools with inadequate temperature and lighting conditions. Likewise, those conditions reduce the effect that teaching practices, disciplinary environment and school day have on learning.Junto a la necesidad de explorar aquellos factores que inciden en el desempeño escolar, y más allá de los condicionantes regularmente evaluados, esta investigación analiza dos variables de contexto muy poco estudiadas y con resultados inconclusos: las condiciones de iluminación y temperatura en las escuelas. Para ese fin, y con el objetivo de medir la incidencia en competencias matemáticas, hace uso de modelos multinivel y de los resultados en el Programa Internacional para la Evaluación de Alumnos (PISA) 2012. Una vez se controla por las características de los estudiantes y las escuelas, así como por los procesos educativos, se encuentra que el puntaje promedio es 15 puntos inferior, y la probabilidad de obtener un desempeño por debajo del nivel básico es un 10% mayor, para los estudiantes en escuelas con inadecuadas condiciones físico-ambientales. Asimismo, esas condiciones reducen el efecto que tienen las prácticas docentes, el ambiente disciplinario y la jornada escolar sobre el aprendizaje

    Peat Bog Wildfire Smoke Exposure in Rural North Carolina Is Associated with Cardiopulmonary Emergency Department Visits Assessed through Syndromic Surveillance

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    Background: In June 2008, burning peat deposits produced haze and air pollution far in excess of National Ambient Air Quality Standards, encroaching on rural communities of eastern North Carolina. Although the association of mortality and morbidity with exposure to urban air pollution is well established, the health effects associated with exposure to wildfire emissions are less well understood. Objective: We investigated the effects of exposure on cardiorespiratory outcomes in the population affected by the fire. Methods: We performed a population-based study using emergency department (ED) visits reported through the syndromic surveillance program NC DETECT (North Carolina Disease Event Tracking and Epidemiologic Collection Tool). We used aerosol optical depth measured by a satellite to determine a high-exposure window and distinguish counties most impacted by the dense smoke plume from surrounding referent counties. Poisson log-linear regression with a 5-day distributed lag was used to estimate changes in the cumulative relative risk (RR). Results: In the exposed counties, significant increases in cumulative RR for asthma [1.65 (95% confidence interval, 1.25–2.1)], chronic obstructive pulmonary disease [1.73 (1.06–2.83)], and pneumonia and acute bronchitis [1.59 (1.07–2.34)] were observed. ED visits associated with cardiopulmonary symptoms [1.23 (1.06–1.43)] and heart failure [1.37 (1.01–1.85)] were also significantly increased. Conclusions: Satellite data and syndromic surveillance were combined to assess the health impacts of wildfire smoke in rural counties with sparse air-quality monitoring. This is the first study to demonstrate both respiratory and cardiac effects after brief exposure to peat wildfire smoke

    Multiple reassortment events in the evolutionary history of H1N1 influenza A virus since 1918

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    The H1N1 subtype of influenza A virus has caused substantial morbidity and mortality in humans, first documented in the global pandemic of 1918 and continuing to the present day. Despite this disease burden, the evolutionary history of the A/H1N1 virus is not well understood, particularly whether there is a virological basis for several notable epidemics of unusual severity in the 1940s and 1950s. Using a data set of 71 representative complete genome sequences sampled between 1918 and 2006, we show that segmental reassortment has played an important role in the genomic evolution of A/H1N1 since 1918. Specifically, we demonstrate that an A/H1N1 isolate from the 1947 epidemic acquired novel PB2 and HA genes through intra-subtype reassortment, which may explain the abrupt antigenic evolution of this virus. Similarly, the 1951 influenza epidemic may also have been associated with reassortant A/H1N1 viruses. Intra-subtype reassortment therefore appears to be a more important process in the evolution and epidemiology of H1N1 influenza A virus than previously realized

    Facial Mask Use and COVID-19 Protection Measures in Jefferson County, Kentucky: Results from an Observational Survey, November 5−11, 2020

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    Introduction: The transmission of respiratory infectious diseases such as COVID-19 can significantly decrease by mask-wearing. However, accurate information about the extent and proper use of the facial mask is scarce. This study’s main objective was to observe and analyze mask-wearing behavior and the level of COVID-19 protection measures in indoor public areas (PAs) of Jefferson County, Kentucky. Methods: For conducting the observational survey study, targets were indoor PAs, and zip codes were defined as surveying clusters. The number of selected PAs in each zip code was proportional to the population and the total number of PAs in that zip code. The PA pool in a zip code was divided into four groups, followed by random selection without replacement from each group. Results: A total of 191 PAs were surveyed: 50 of them were grocery stores, 56 were convenience stores or pharmacies, 39 were wine and liquor stores, and 46 were other stores. At least one unmasked and one incorrectly masked staff were observed in 26% and 40% of the sampled PAs, respectively. Also, in 29% and 35% of the PAs, at least one unmasked and one incorrectly masked visitor were observed, respectively. The rates varied by PA size and county district. Eighty percent of unmasked staff and 75% of the unmasked visitors were male. The rate of unmasked males varied from 50% to 100% across districts. About 66% of unmasked staff among all Jefferson County districts were young adults. More than one-fourth of all the PAs provided hand sanitizer for visitors’ use, and only 2% of the PAs provided masks to their visitors. Conclusion: Messaging about mask use and correct usage may need to particularly target the 19-44-year-old male population, as these individuals were the most prevalent among those unmasked and masked incorrectly. Additionally, businesses’ protective measures may depend on their resources to operate in such a manner. Hand sanitizer is easier to offer visitors, while staffing to regularly sanitize carts or funds to provide a sufficient number of wipes, gloves, or masks may present further opportunities for government assistance
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