Proceso de producción del Yacón de Bárcena, Jujuy: estudio de caso para la intervención del diseño en el agregado de valor a productos elaborados en la CAPP

El presente trabajo parte del análisis del proceso de producción de yacón efectuado por la Cooperativa Agrícola Portal de Patrimonio (CAPP) en la localidad de Bárcena, Jujuy, Argentina. La cooperativa fue creada con el fin de concentrar a los productores familiares de la localidad de Bárcena y recuperar y poner en valor su cultivo característico que fue perdiendo territorio de producción entre los años 1990 y 2005. En este proceso intervinieron diferentes actores sociales: habitantes de Bárcena, maestros, productores locales y referentes técnicos vinculados a organismos civiles y estatales. El eje de estudio sobre el que se basa esta ponencia se centra, por un lado, en el funcionamiento de la cooperativa en la localidad y en el rol de los actores sociales que intervienen. Por otro, en la posible injerencia del diseño en el proceso de producción de derivados del yacón elaborados a nivel local. Para ello, se estudia la cadena de valor, los agentes que intervienen en ella, y se analiza las oportunidades de agregar valor al cultivo a nivel local. Del mismo modo, se generan preguntas vinculadas a las posibilidades de acción en un territorio concreto. En este marco, interesa indagar sobre el proceso de organización local. A su vez, estudiar y comprender qué dimensiones son necesarias cuestionar para producir reapropiaciones en las etapas del proceso de generación de valor. Este estudio se inicia a partir de las conclusiones de investigación de la tesis de maestría “Valor agregado en la cadena de los derivados del Yacón de Bárcena, Jujuy, Argentina”.GT21: Ruralidades en transformación en el marco del capitalismo global: Trabajo, políticas públicas, medio ambiente, mercados y alimentación.Universidad Nacional de La Plat

Effect of animal trampling on the properties of a soil. Part II: infiltration and saturated hydraulic conductivity

Fil: Martínez, Daniel A. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Física; Argentina.Fil: Landini, Ana M. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Física; Argentina.Fil: Soza, Eudardo. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Maquinaria Agrícola; Argentina.Fil: Sainato, Claudia M. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Física; Argentina.Fil: Heredia, Olga S. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Edafología; Argentina.It is important to predict the infiltration process of a soil in order to develop future management strategies for animal production that take into account contamination risks. There are few studies in which basic infiltration rate (TIB) and saturated hydraulic conductivities measured in laboratory (Ks) are compared. The objectives of this study were: 1) To measure the infiltration process for four trampling intensities: zero (control), medium, high and very high; 2) To measure and compare the TIB and Ks; 3) To evaluate the efficiency of the Green and Ampt model (GA) and several pedotransfer functions (FPT) in predicting the infiltration process. The study was carried out in an animal production facility located in Buenos Aires, Argentina, with Argiudolls soils in a plain with planted grasslands. The infiltration process was measured with rings of Muntz and Ks in the laboratory using a constant head permeameter. It was found that the TIB decreased to half its value in areas with very high trampling with respect to the control soil. Ks were lower in areas with higher trampling. It was concluded that Ks values were between 5 and 10 times higher than those of TIB. The GA model predicted the approximate infiltration process when its parameters were obtained by FPT from European soils, but not with FPT with parameters from American soils. This is attributed to the fact that Ks values predicted by the European FPT are lower than those obtained using American FPTs.Es importante predecir el proceso de infiltración en el suelo para elaborar estrategias de manejo de la producción animal, que tengan en cuenta riesgos de contaminación. Por otra parte, existen pocos trabajos en donde se comparan las tasas de infiltración básicas (TIB) medidas a campo con las conductividades hidráulicas saturadas (Ks) obtenidas en laboratorio. Los objetivos del experimento fueron: 1) Medir el proceso de infiltración para cuatro intensidades de pisoteo: nula (testigo), media, alta y muy alta; 2) Medir y comparar las TIB de campo y las Ks en laboratorio; 3) Evaluar la eficiencia del modelo Green y Ampt (GA) junto con el de varias funciones de pedotransferencia (FPT) para predecir el proceso de infiltración. El estudio se realizó en un establecimiento de producción animal ubicado en Buenos Aires, Argentina, con suelos Argiudoles, en una llanura con pastura implantada. El proceso de infiltración se midió con anillos de Muntz y la Ks en laboratorio con un permeámetro de carga constante. Se encontró que la TIB disminuyó a la mitad de su valor en los sectores con muy alta carga animal respecto del suelo testigo. La Ks resultó menor en sitios con mayor carga animal. Conclusiones: Los valores de Ks resultaron entre 5 y 10 veces mayores que los de TIB. El modelo de GA predijo en forma aproximada el fenómeno de infiltración cuando sus parámetros fueron obtenidos por una FPT proveniente de suelos europeos, no así con parámetros de suelos norteamericanos. Esto se atribuye a que los valores de Ks predichos por la FPT europea son menores a los obtenidos con las FPTs de suelos norteamericanos

Phylogenetic insights into the correlates of dioecy in meadow-rues (Thalictrum, Ranunculaceae)

Numerous studies have examined the evolution of sexual systems in angiosperms, but few explore the interaction between these and the evolution of pollination mode. Wind pollination is often associated with unisexual flowers, but which evolved first and played a causative role in the evolution of the other is unclear. Thalictrum, meadow-rues (Ranunculaceae), provides a unique opportunity to study the evolution of these traits because it contains insect and wind pollination and four sexual systems. We used a phylogenetic approach to reconstruct ancestral states for sexual system, pollination mode, and geographic distribution in Thalictrum, and tested for correlations to uncover the factors involved in the evolution of unisexuality and wind pollination. Our results show that dioecy, andro- and gynomonoecy evolved at least twice from hermaphroditism. Wind pollination, unisexual flowers, and New World distribution were all significantly correlated. Wind pollination may have evolved early in the genus, followed by multiple losses and gains, and likely preceded the origin of unisexual flowers in several cases; we found no evidence for unisexual flowers evolving prior to wind pollination. Given a broad scale study showing the evolution of dioecy before wind pollination, our results from a finer scale analysis highlight that different evolutionary pathways are likely to occur throughout angiosperms.Keywords: ITS, Thalictrum, Dioecy, rpl16, Monoecy, Wind pollinationKeywords: ITS, Thalictrum, Dioecy, rpl16, Monoecy, Wind pollinatio

Seroprevalencia de marcadores de infecciones transmisibles por vía transfusional en banco de sangre de Colombia

OBJETIVO: Determinar la seroprevalencia de marcadores de infecciones transmisibles por vía transfusional. MÉTODOS: Estudio transversal con fuente de información secundaria, basada en los resultados de pruebas biológicas en los donantes de un banco de sangre de Medellín, Colombia, de 2007 a 2010. Se determinó la seroprevalencia de los marcadores de infección y se compararon según sexo y tipo de donante a través de análisis de frecuencias, chi cuadrado, Fisher y razones de prevalencia. RESULTADOS: La población de base estuvo conformada por 65.535 donantes de los cuales, 3,3% presentaran al menos una prueba biológica positiva. El marcador más prevalente en las pruebas del banco de sangre fue sífilis (1,2%), seguido de tripanosomiasis (1,0%), virus de la hepatitis C (VHC) (0,6%), virus de la inmunodeficiencia humana (VIH) (0,5%) y virus de la hepatitis B (VHB) (0,2%). Con base en el laboratorio de referencia se halló una prevalencia de 0,6% para sífilis, 0,1% para VHB y 0% para VHC, VIH y Chagas. Se hallaron diferencias estadísticas en la prevalencia de VHB y sífilis según sexo y tipo de donante. CONCLUSIONES: Los resultados son coherentes con las prevalencias dadas por la Organización Panamericana de la Salud (OPS) y se pueden correlacionar con la prevalencia mundial de las infecciones transmisibles por via transfusional. Los resultados hallados en las pruebas del banco de sangre posibilitan la disminución del riesgo transfusional pero limitan la optimización de recursos al excluir donantes clasificados como falsos positivos

Travel Demand Modeling Methodology Recommendations for the Link21 Program

This project aims to provide recommendations on the methodology and design specifications for the travel demand model to be built for the Link21 program in the Northern California megaregion. The Link21 program is a major rail investment program that will considerably improve and upgrade the passenger rail services in the Northern California megaregion, centered around the Transbay Corridor between Oakland and San Francisco in the San Francisco Bay Area

Incidence and mortality rates of selected infection-related cancers in Puerto Rico and in the United States

<p>Abstract</p> <p>Background</p> <p>In 2002, 17.8% of the global cancer burden was attributable to infections. This study assessed the age-standardized incidence and mortality rates of stomach, liver, and cervical cancer in Puerto Rico (PR) for the period 1992-2003 and compared them to those of Hispanics (USH), non-Hispanic Whites (NHW), and non-Hispanic Blacks (NHB) in the United States (US).</p> <p>Methods</p> <p>Age-standardized rates [ASR(World)] were calculated based on cancer incidence and mortality data from the PR Cancer Central Registry and SEER, using the direct method and the world population as the standard. Annual percent changes (APC) were calculated using the Poisson regression model from 1992-2003.</p> <p>Results</p> <p>The incidence and mortality rates from stomach, liver and cervical cancer were lower in NHW than PR; with the exception of mortality from cervical cancer which was similar in both populations. Meanwhile, the incidence rates of stomach, liver and cervical cancers were similar between NHB and PR; except for NHB women who had a lower incidence rate of liver cancer than women in PR. NHB had a lower mortality from liver cancer than persons in PR, and similar mortality from stomach cancer.</p> <p>Conclusions</p> <p>The burden of liver, stomach, and cervical cancer in PR compares to that of USH and NHB and continues to be a public health priority. Public health efforts are necessary to further decrease the burden of cancers associated to infections in these groups, the largest minority population groups in the US. Future studies need to identify factors that may prevent infections with cancer-related agents in these populations. Strategies to increase the use of preventive strategies, such as vaccination and screening, among minority populations should also be developed.</p

Management of Hepatitis C Antiviral Therapy Adverse Effects

Hepatitis C is one of the leading causes of liver disease in the United States, affecting more than 4 million individuals. The current treatment regimen involves pegylated interferon in combination with ribavirin. Although antiviral treatment has been associated with a greater than 50% sustained viral response rate, the adverse effects have proven to be detrimental to quality of life and therapy adherence, and consequently lead to lower sustained viral response rates. This article identifies the most frequently described complications associated with pegylated interferon and ribavirin. The active management of these complications is discussed, including both preventive and empiric treatments

Extended Interferon-Alpha Therapy Accelerates Telomere Length Loss in Human Peripheral Blood T Lymphocytes

BACKGROUND: Type I interferons have pleiotropic effects on host cells, including inhibiting telomerase in lymphocytes and antiviral activity. We tested the hypothesis that long-term interferon treatment would result in significant reduction in average telomere length in peripheral blood T lymphocytes. METHODS/PRINCIPAL FINDINGS: Using a flow cytometry-based telomere length assay on peripheral blood mononuclear cell samples from the Hepatitis-C Antiviral Long-term Treatment against Cirrhosis (HALT-C) study, we measured T cell telomere lengths at screening and at months 21 and 45 in 29 Hepatitis-C virus infected subjects. These subjects had failed to achieve a sustained virologic response following 24 weeks of pegylated-interferon-alpha plus ribavirin treatment and were subsequently randomized to either a no additional therapy group or a maintenance dose pegylated-IFNalpha group for an additional 3.5 years. Significant telomere loss in naive T cells occurred in the first 21 months in the interferon-alpha group. Telomere losses were similar in both groups during the final two years. Expansion of CD8(+)CD45RA(+)CD57(+) memory T cells and an inverse correlation of alanine aminotransferase levels with naive CD8(+) T cell telomere loss were observed in the control group but not in the interferon-alpha group. Telomere length at screening inversely correlated with Hepatitis-C viral load and body mass index. CONCLUSIONS/SIGNIFICANCE: Sustained interferon-alpha treatment increased telomere loss in naive T cells, and inhibited the accumulation of T cell memory expansions. The durability of this effect and consequences for immune senescence need to be defined