Item statistics derived from three-option versions of multiple-choice questions are usually as robust as four- or five-option versions: implications for exam design.

Different versions of multiple-choice exams were administered to an undergraduate class in human physiology as part of normal testing in the classroom. The goal was to evaluate whether the number of options (possible answers) per question influenced the effectiveness of this assessment. Three exams (each with three versions) were given to each of two sections during an academic quarter. All versions were equally long, with 30 questions: 10 questions with 3 options, 10 questions with 4, and 10 questions with 5 (always one correct answer plus distractors). Each question appeared in all three versions of an exam, with a different number of options in each version (three, four, or five). Discrimination (point biserial and upper-lower discrimination indexes) and difficulty were evaluated for each question. There was a small increase in difficulty (a lower average score on a question) when more options were provided. The upper-lower discrimination index indicated a small improvement in assessment of student learning with more options, although the point biserial did not. The total length of a question (number of words) was associated with a small increase in discrimination and difficulty, independent of the number of options. Quantitative questions were more likely to show an increase in discrimination with more options than nonquantitative questions, but this effect was very small. Therefore, for these testing conditions, there appears to be little advantage in providing more than three options per multiple-choice question, and there are disadvantages, such as needing more time for an exam

Globalization and land-use transitions in Latin America

Current socioeconomic drivers of land-use change associated with globalization are producing two contrasting land-use trends in Latin America. Increasing global food demand (particularly in Southeast Asia) accelerates deforestation in areas suitable for modern agriculture (e.g., soybean), severely threatening ecosystems, such as Amazonian rain forests, dry forests, and subtropical grasslands. Additionally, in the coming decades, demand for biofuels may become an emerging threat. In contrast, high yields in modern agricultural systems and rural–urban migration coupled with remittances promote the abandonment of marginal agricultural lands, thus favoring ecosystem recovery on mountains, deserts, and areas of poor soils, while improving human well-being. The potential switch from production in traditional extensive grazing areas to intensive modern agriculture provides opportunities to significantly increase food production while sparing land for nature conservation. This combination of emerging threats and opportunities requires changes in the way the conservation of Latin American ecosystems is approached. Land-use efficiency should be analyzed beyond the local-based paradigm that drives most conservation programs, and focus on large geographic scales involving long-distance fluxes of products, information, and people in order to maximize both agricultural production and the conservation of environmental services.Fil: Grau, Hector Ricardo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Mitchell, Aide. Universidad de Puerto Rico; Puerto Ric

Assessment of humoral and cellular immune responses of the RTS,S/AS02D malaria vaccine candidate administered to infants living in a malaria endemic area in Mozambique

MSc (Med), Faculty of Health Sciences, University of the Witwatersrand, 2009Background: RTS,S candidate malaria vaccine has been shown to be highly immunogenic in children and infants, but the protective immune mechanisms still remain to be clearly elucidated. It is believed that RTS,S elicits a strong neutralizing humoral immune response directed against surface-exposed sporozoite proteins and cell mediated immune (CMI) responses characterized by predominantly CD4+ Th1 cells. The objective of this study was to investigate humoral and cell-mediated immune responses to the RTS,S/AS02D malaria vaccine and its association with protection against infection and disease by P. falciparum. Methodology and Principal Findings: This secondary data analysis from data of a phase I/IIb randomized, double-blind, controlled trial, included 154 healthy infants living in rural Mozambique, previously immunized with RTS,S/AS02D candidate malaria vaccine or the control Engerix-B™ vaccine. Antibodies against circumsporozoite protein (CSP) and hepatitis-B surface antigen (HBsAg) were measured with a standard ELISA. Fresh blood intracellular staining assay was performed to evaluate the expression of IL-2 and IFN-γ by CD4+ and CD8+ cells in response to in vitro stimulation of specific peptides. Data was evaluated for association with the risk of malaria detected by both active and passive case detection of infection over a period of 6 months post dose 3. Anti-HBs antibody geometric mean titers declined from 10,082 mIU/mL one month post Dose 3 to 2,751 mIU/mL at 12 months post Dose 3 in the RTS,S/AS02D group; anti-HBs v geometric mean titers were 392.4 mIU/mL and 263.9 mIU/mL, respectively in the Engerix- BTM group. Anti-CSP antibody geometric mean titers declined from 199.9 EU/mL one month post Dose 3 to 7.3 EU/mL at 12 months post Dose 3 in the RTS,S/AS02D group. Median stimulation indices of HBs-specific IL-2 and IFN-γ producing CD8+ T cells was higher in the RTS,S/AS02D group than in control group (Wilcoxon rank sum p-values for IFN-γ = 0.015, for IL-2 = 0.030) at 10.5 weeks post immunization. Median stimulation indices of anti-CSP specific IFN-γ producing CD8+ T cells at the same time point was 1.13 (IQR: 0.79 - 1.67; p=0.029). For specific IL-2-producing CD4+ T cells, the median SI was 1.14 (IQR: 0.74 – 1.60, p=0.043) at 10.5 weeks post dose three. The reduction in hazards of malaria infection were 18.3 % (95% CI: -267.9 – 81.8, p=0.793) and -12.0 % (95% CI: -295 – 68.2, p=0.86) for specific IL-2 CD4+ stimulation indices; For specific CD8+ IFN-γ stimulation indices the hazards were -103.6% (95% CI: -690.9 – 47.6; p=0.305) and 48.8% (95% CI: -97.0 – 86.7; p=0.33) at four and 10.5 weeks post immunization respectively. Conclusion: The RTS,S/AS02D vaccine was immunogenic and has elicited detectable levels of CSP specific cell mediated responses. No evidence of association was found between the antibodies anti-CSP and specific cell mediated responses and the risk of malaria

Genetic characterization of the Ma locus with pH and titratable acidity in apple

Apple fruit flavor is greatly affected by the level of malic acid, which is the major organic acid in mature apple fruit. To understand the genetic and molecular basis of apple fruit acidity, fruit juice pH and/or titratable acidity (TA) were measured in two half-sib populations GMAL 4595 [Royal Gala×PI (Plant Introduction) 613988] and GMAL 4590 (Royal Gala×PI 613971) of 438 trees in total. The maternal parent Royal Gala is a commercial variety and the paternal parents are two M. sieversii (the progenitor species of domestic apple) elite accessions. The low-acid trait segregates recessively and the overall acidity variations in the two populations were primarily controlled by the Ma (malic acid) locus, a major gene discovered in the 1950s (Nybom in Hereditas 45:332-350, 1959) and later mapped to linkage group 16 (Maliepaard et al. in Theor Appl Genet 97:60-73, 1998). The allele Ma has a strong additive effect in increasing fruit acidity and is incompletely dominant over ma. QTL (quantitative trait locus) analyses in GMAL 4595 mapped the major QTL Ma in both Royal Gala and PI 613988, the effects of which explained 17.0-42.3% of the variation in fruit pH and TA. In addition, two minor QTL, tentatively designated M2 and M3, were also detected for fruit acidity, with M2 on linkage group 6 of Royal Gala and M3 on linkage group 1 of PI 613988. By exploring the genome sequences of apple, eight new simple sequence repeat markers tightly linked to Ma were developed, leading to construction of a fine genetic map of the Ma locus that defines it to a physical region no larger than 150kb in the Golden Delicious genom

Influencia del marketing político en los electores que votaron por primera vez en las elecciones federales del 2012, en la cabecera municipal de Ixtlahuaca

Contiene esquemas y cuadrosHan existido cambios paulatinos dentro de las sociedades debido a las diferentes necesidades, asimismo, los cambios sociales surgen como respuesta a la transformación científica y tecnológica, la organización socioeconómica y política, se transforma de un líder absoluto y designado por poderes divinos, a líderes en diferentes ámbitos y niveles de gobierno que en su mayoría son elegidos de forma democrática, de tal manera que el voto es una de las cuestiones de mayor relevancia en una democracia. La vida social se adapta al constante desarrollo, al día a día de las diversas sociedades existentes en el mundo, se tiene que ajustar a las normas y reglas necesarias para llevar una sana convivencia entre las personas que se encuentran en un mismo espacio geográfico, en un mismo territorio y con el mismo marco jurídico. La manera de cómo obtener el voto, ha sido una de las principales preocupaciones que giran en torno a la vida política de cualquier sociedad, como lo es en la Cabecera del municipio de Ixtlahuaca, Estado de México, en donde los jóvenes que oscilan en un rango de 18-24 años de edad juegan un papel muy importante puesto que son actores decisivos de la vida política nacional, pero que también son agentes que pueden ser sujetos a manipulación debido a que es la primera vez que emiten el voto, por lo que es necesario conocer aquellos factores del marketing político que influyen en su decisión electoral. El Marketing Político, sus principales factores y estrategias afectan de manera innegable el poder de decisión de los individuos que emiten por primera vez su voto durante las elecciones presidenciales, de tal manera que será fundamental generar y analizar elementos teóricos que creen una nueva perspectiva del Marketing Político y su influencia en los jóvenes electores, ya que de esta manera se podrá crear conciencia respecto del papel que desempeñan en la vida política de la nación. Las elecciones y la forma de obtener el voto siempre representarán un tema de estudio para los científicos sociales dedicados al profundo análisis de la vida política mexicana, académicamente hablando, ampliar el universo de conocimiento de la realidad política mexicana será bien recibido puesto que los fenómenos sociales son únicos e irrepetibles, de esta manera tener un estudio sobre un caso particular contribuye a crear un acervo de conocimiento político. En particular el conocimiento que se pueda obtener de realizar un trabajo de investigación respecto de la “Influencia del marketing político en los electores que votaron por primera vez en las elecciones federales del 2012, en la cabecera del municipio de Ixtlahuaca” contribuirá a crear una visión holística de la política en México y su forma de desarrollarse a través de la conciencia ciudadana. Se podrá generar una visión integra del cambio que sufre día con día la sociedad, sobre todo el cambio que experimentan los jóvenes de la comunidad de Ixtlahuaca, respecto la influencia que se recibe de los factores del Marketing y cómo estos afectan innegablemente en su forma de emitir por primera vez su voto. El Marketing Político en años recientes se ha convertido en una herramienta infalible en cuanto a la manera de persuadir a un elector, debido a las estrategias utilizadas en cada uno de los rubros de las contiendas electorales, también por el desarrollo y uso de las nuevas tecnologías. En esta investigación se trata de percibir la realidad de los jóvenes electores, aquellos que se convierten en un factor clave y decisivo del rumbo que tomará la política nacional. Esta investigación tiene como propósito analizar las nuevas herramientas que utilizan los partidos políticos a través del marketing político para persuadir al nuevo electorado, así mismo, se demostrará que la televisión sigue siendo el principal conducto para el flujo de información entre política y sociedad, siendo aún el primer medio que provee de información al electorado para poder emitir su voto y estar al tanto de la realidad política que se vive en el país, a pesar del uso del internet y otros medios de comunicación en el marketing político utilizado en las elecciones presidenciales del 2012. Otro propósito de esta investigación es contribuir a la consolidación del estudio del Marketing Político en México, sobre todo en los municipios de Estado de México, partiendo en este proyecto de investigación del Municipio de Ixtlahuaca, ya que contribuirá a crear antecedentes de estudios que puedan contribuir en un futuro a todas aquellas investigaciones que puedan surgir derivadas de esta investigación. Lo fundamental de la investigación es proporcional a un universo entendible de la influencia del Marketing Político que contribuyen de una forma u otra a fundar la decisión del joven elector en un rango de edad de 18-24 años, la investigación será decisiva debido a que ofrece una contribución importante respecto de la vida política nacional, de aquí se derivara el entendimiento de los factores que llevaron al resultado de las elecciones presidenciales del 2012 y la manera en que contribuye la Cabecera del municipio de Ixtlahuaca en esta vital decisión

El clima organizacional y su influencia en el desempeño laboral de los trabajadores de la ONG - CDSP 338 Luminares del Mundo - La Victoria

La apreciación de un buen clima organizacional por parte de los trabajadores de cualquier empresa ha tomado vital importancia pues se ha demostrado una buena relación con el desempeño laboral. Con base en estas percepciones es que se desarrolló la presente investigación en la ONG CDSP 338- Luminares del Mundo- La Victoria cuyo objetivo principal es determinar la influencia del clima organizacional en el desempeño laboral de los trabajadores de la ONG en mención. Para la realización de dicho estudio se utilizó como instrumento de medición un cuestionario para Clima Organizacional de 35 preguntas contestado íntegramente por los trabajadores de la ONG y otro de 7 preguntas para el desempeño laboral que fue evaluado por su supervisor que permitió medir cada variable en la escala de Likert basándonos en 8 dimensiones para Clima Organizacional propuestas por distintos autores como: Litwin y Stringer, Bowers y Taylor Newman, Tagiuri, Schnedider y Bartlett y Pritchard y Karasick y 2 del Desempeño Laboral explicadas por Chiavenato. Tal instrumento fue aplicado a los 21 trabajadores de la ONG CDSP 338 – Luminares del Mundo – La Victoria, utilizando el Alfa de Cronbach para la fiabilidad del instrumento obteniendo un resultado de 0.944 de apreciación elevada. La información recopilada fue procesada con el Programa SPSS para su análisis. Con los resultados se determina que existe un grado de correlación muy fuerte, ya que la significación es de 0,000 menor de 0,05 y la correlación de Pearson r = 0,741**, por cuanto a mejor Clima Organizacional en el CDSP 338 mayor es el Desempeño de los trabajadores. Por otro lado encontramos evidencia a favor de la hipótesis: Clima organizacional y su influencia en el desempeño laboral de los trabajadores de la ONG CDSP 338 – Luminares del Mundo – La Victoria. Al finalizar la investigación se hizo el análisis por dimensiones para encontrar las dimensiones del clima organizacional que tienen mayor influencia con el desempeño laboral

Nuclear Physics on the Light Front

High energy scattering experiments involving nuclei are typically analyzed in terms of light front variables. The desire to provide realistic, relativistic wave functions expressed in terms of these variables led me to try to use light front dynamics to compute nuclear wave functions. The progress is summarized here.Comment: 4 pages, text of presentation made at PANIC9

Tannerella forsythia is associated with increased levels of atherogenic low density lipoprotein and total cholesterol in chronic periodontitis

Background: Accumulating evidence suggests that acute and chronic infections with periodontopathogens are associated with an increased risk of cardiovascular disease. The objective of this study was to assess whether Tannerella forsythia and Porphyromonas gingivalis are associated with increased levels of atherogenic low-density lipoprotein (LDL), high-density lipoprotein, total cholesterol (TC), triglycerides and body mass index (BMI) in chronic periodontitis patients. Material and Methods: Medical history and clinical and radiographic examination were conducted in 80 chronic periodontitis patients and 28 healthy individuals. Fasting blood samples were drawn for the measurement of the parameters of dyslipidemia. Anthropometric measurements such as height in meters and weight in kilograms were recorded. Both periodontitis and control subjects were asked to answer a questionnaire with regard to their socio- demographic and smoking status. The presence of T. forsythia , and P. gingivalis was detected using primers designed to target the respective 16S rRNA gene sequences. Results: The occurrence of T. forsythia and P. gingivalis was higher in the group of subjects with periodontitis. Superior levels of triglycerides were observed in chronic periodontitis patients compared to healthy individuals. High levels of TC in periodontitis persons were significantly associated with increased bleeding on probing. Greater mean levels of TC and LDL were shown in the presence of T. forsythia ( P <0.05). Likewise, higher proportions of patients with BMI ≥25 kg/m 2 related with T. forsythia ( P <0.05). T. forsythia was a significant discriminating factor in the multivariate linear regression model emerging as significant explanatory of increased levels of TC (β=17,879, 95% CI = 4,357-31,401; p =0.01) and LDL (β=17,162, 95% CI= 4,009-30,316; p =0.01). Conclusions: Higher levels of serum total cholesterol and LDL were observed in the occurrence of T. forsythia and the presence of this periodontopathogen may increase the atherogenic potency of low-density lipoprotein that may augment the risk for atherosclerosis in periodontal disease patients

Mortality by influenza-related causes in the elderly in Brazil, from 1992 to 2005

Trata-se de um estudo ecológico de séries temporais que teve como objetivo descrever a mortalidade por doenças respiratórias relacionadas à influenza em pessoas com 60 anos ou mais de idade, no Brasil (1992-2005), utilizando dados secundários do Sistema de Informações sobre Mortalidade (SIM) e estimativas populacionais do Instituto Brasileiro de Geografia e Estatística (IBGE). As taxas de mortalidade foram estratificadas por ano, mês, sexo, faixa etária, região e capitais agregadas por região e foram padronizadas pelo método direto (população padrão: Brasil – Censo de 2000). Observou-se tendência crescente nas taxas de mortalidade com o aumento da idade da população de estudo. Valores mais elevados também foram observados entre os homens, em todas as faixas etárias, e entre os residentes das regiões Sul, Sudeste e Centro-Oeste do país. Outros estudos são necessários para analisar as tendências da mortalidade e ampliar o debate sobre os benefícios da vacinação. _______________________________________________________________________________________ ABSTRACTThis is a time-series ecological study aiming to analyze the mortality due to influenza-related respiratory diseases among people aged 60 or over in Brazil (1992-2005), using secondary data from the Mortality Information System (SIM) and from the Brazilian Institute of Geography and Statistics (IBGE). The mortality rates were stratified by year, month, sex, age group, and regions. Capital cities were aggregated by region. Rates were standardized using the direct method (standard population: Brazil – Census 2000). Mortality rates had an increased trend as the study population grew older. Higher values were also observed among males in all age groups and among individuals living in the Southern, Southeastern and Midwestern regions. Complementary studies are necessary to analyze trends of mortality rates, as well as to extend the debate on the effectiveness of influenza vaccination

Characterization of the microbiota associated to Pecten maximus gonads using 454-pyrosequencing

A next-generation sequencing (NGS) approach was used to study the microbiota associated to Pecten maximus broodstock, applying pyrosequencing of PCR-amplified V1-V4 16S rRNA gene regions. We analysed the resident bacterial communities in female and male scallop gonads before and after spawning. DNA samples were amplified and quality-filtered reads were assigned to family and genus taxonomic levels using the Ribosomal Database Project classifier. A total of 18,520 sequences were detected, belonging to 13 phyla, including Proteobacteria (55%), Bacteroidetes (11,7%), Firmicutes (3%), Actinobacteria (2%) and Spirochaetes (1,2%), and 110 genera. The major fraction of the sequences detected corresponded to Proteobacteria, Beta- and Gammaprotebacteria being the most abundant classes. The microbiota of P. maximus gonad harbour a wide diversity, however differences on male and female samples were observed, where female gonad samples show a larger number of genera and families. The dominant bacterial genera appeared to be Delftia, Acinetobacter, Hydrotalea, Aquabacterium, Bacillus, Sediminibacterium, Sphingomonas, and Pseudomonas that were present among the four analysed samples. This next generation sequencing technique, applied for the first time in P. maximus (great scallop) gonads was useful for the study of the bacterial communities in this mollusc, unravelling the great bacterial diversity in its microbiota. [Int Microbiol 19(2): 93-99(2016)]Keywords: Pecten maximus &middot; gonads microbiota &middot; next-generation sequencing (NGS) &middot; molluscs pathogens &middot; aquacultur