Analyzing collaborative learning processes automatically

In this article we describe the emerging area of text classification research focused on the problem of collaborative learning process analysis both from a broad perspective and more specifically in terms of a publicly available tool set called TagHelper tools. Analyzing the variety of pedagogically valuable facets of learners’ interactions is a time consuming and effortful process. Improving automated analyses of such highly valued processes of collaborative learning by adapting and applying recent text classification technologies would make it a less arduous task to obtain insights from corpus data. This endeavor also holds the potential for enabling substantially improved on-line instruction both by providing teachers and facilitators with reports about the groups they are moderating and by triggering context sensitive collaborative learning support on an as-needed basis. In this article, we report on an interdisciplinary research project, which has been investigating the effectiveness of applying text classification technology to a large CSCL corpus that has been analyzed by human coders using a theory-based multidimensional coding scheme. We report promising results and include an in-depth discussion of important issues such as reliability, validity, and efficiency that should be considered when deciding on the appropriateness of adopting a new technology such as TagHelper tools. One major technical contribution of this work is a demonstration that an important piece of the work towards making text classification technology effective for this purpose is designing and building linguistic pattern detectors, otherwise known as features, that can be extracted reliably from texts and that have high predictive power for the categories of discourse actions that the CSCL community is interested in

Epidemiology and control of Salmonella in the pork production chain: the approach in a high prevalence country (Spain)

The present study summarises the insights yielded by different studies focused on the epidemiology of the infection by Salmonella through the pig production (breeders, finishers and post-farm stages). The final objective is to determine the best strategies for successful control of Salmonella in a highly prevalent country such as Spain. The study in breeders evidenced a high seroprevalence. There were differences among some of the 10 most common serotypes detected in breeders compared to previous studies in finishers, although the two most common were shared by both populations. Type of feed and type of floor were the factors associated to the presence of Salmonella. A Salmonella Typhimurium inactivated vaccine and two organic acids demonstrated to be good tools to reduce the prevalence in finishers. Finally a study of the contamination in post-farm stages evidenced the high contamination of transport, lairage and the contamination of the slaughter line, accounting for 70% of carcass cross-contamination

Rodent herpesvirus Peru encodes a secreted chemokine decoy receptor

Viruses have long been studied not only for their pathology and associated disease but also as model systems for understanding cellular and immunological processes. Rodent herpesvirus Peru (RHVP) is a recently characterized rhadinovirus related to murine gammaherpesvirus 68 (MHV68) and Kaposi's sarcoma-associated herpesvirus (KSHV) that establishes acute and latent infection in laboratory mice. RHVP encodes numerous unique proteins that we hypothesize might facilitate host immune evasion during infection. We report here that open reading frame (ORF) R17 encodes a high-affinity chemokine binding protein that broadly recognizes human and murine CC and C chemokines. The interaction of R17 with chemokines is generally characterized by rapid association kinetics, and in the case of CCL3, CCL4, CCL5, CCL24, and XCL1, extremely stable complexes are formed. Functionally, R17 potently inhibited CCL2-driven chemotaxis of the human monocytic cell line THP-1, CCL3-driven chemotaxis of peripheral blood mononuclear cells, and CCL2-mediated calcium flux. Our studies also reveal that R17 binds to glycosaminoglycans (GAGs) in a process dependent upon two BBXB motifs and that chemokine and GAG binding can occur simultaneously at distinct sites. Collectively, these studies suggest that R17 may play a role in RHVP immune evasion through the targeted sabotage of chemokine-mediated immune surveillance

Electroexcitation of the Δ+(1232)\Delta^{+}(1232) at low momentum transfer

We report on new p$(e,e^\prime p)\pi^\circ$ measurements at the $\Delta^{+}(1232)$ resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low $Q^2$ dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements

Pb(II) Induces Scramblase Activation and Ceramide-Domain Generation in Red Blood Cells

The mechanisms of Pb(II) toxicity have been studied in human red blood cells using confocal microscopy, immunolabeling, fluorescence-activated cell sorting and atomic force microscopy. The process follows a sequence of events, starting with calcium entry, followed by potassium release, morphological change, generation of ceramide, lipid flip-flop and finally cell lysis. Clotrimazole blocks potassium channels and the whole process is inhibited. Immunolabeling reveals the generation of ceramide-enriched domains linked to a cell morphological change, while the use of a neutral sphingomyelinase inhibitor greatly delays the process after the morphological change, and lipid flip-flop is significantly reduced. These facts point to three major checkpoints in the process: first the upstream exchange of calcium and potassium, then ceramide domain formation, and finally the downstream scramblase activation necessary for cell lysis. In addition, partial non-cytotoxic cholesterol depletion of red blood cells accelerates the process as the morphological change occurs faster. Cholesterol could have a role in modulating the properties of the ceramide-enriched domains. This work is relevant in the context of cell death, heavy metal toxicity and sphingolipid signaling.AGA was a predoctoral student supported by the Basque Government and later by the University of the Basque Country (UPV/EHU). This work was also supported in part by grants from the Spanish Government (FEDER/MINECO BFU 2015-66306-P to F.M.G. and A.A.) and the Basque Government (IT849-13 to F.M.G. and IT838-13 to A.A.), and by the Swiss National Science Foundation

Diagnóstico del cultivo de tomate en la zona metropolitana de Bucaramanga

El tomate es una hortaliza de gran demanda en el área metropolitana de Bucaramanga, para consumo fresco, como condimento y en forma de salsa. El presente estudio se adelantó con el propósito de conocer la problemática del cultivo de tomate respecto a la utilización de agroquímicos, mano de obra y fotosanidad, en los cultivos establecidos en el área de influencia de Bucaramanga en el año de 1987. Para la realización de este trabajo se encuestaron 25 agricultores ubicados en 14 veredas de vocación tomatera de los municipios de Bucaramanga, Floridablenca, Piedecuesta, Girón y Cepitá. Los resultados más importantes de la investigación fueron: la mayoría de los agricultores manejan inadecuadamente el cultivo en cuanto a labores culturales básicas. El control de plagas y enfermedades lo hacen por calendario, notándose un total desconocimiento de los sistemas de manejo integrado de plagas y enfermedades que tan excelentes resultados ha producido en otras zonas de cultivo como los del Valle del Cauca. Se encontró igualmente que no se destruyen los residuos de cosecha no se practica la rotación de cultivos de manera significativa. Hay uso indiscriminado y deficiente aplicación de plaguicidas con lo cual se incrementan los costos de producción y se contamina el producto cosechado, el cultivador y el ambiente. Los problemas fitosanitarios relevantes detectados en la fecha, lo constituyen los nemátodos, el barrenador del fruto (Neoleucinodes elegantalis), la virosis y la gota, La rentabilidad del cultivo es baja, el crédito insuficiente e inoportuno y no se cuenta con asistencia técnicaTomate-Solanum lycopersicu

Análisis de los sistemas agropecuarios del departamento de Santander.

Se describen y analizan las características ambientales, sociales y económicas del sector agropecuario del departamento de Santander y los componentes de los sistemas agropecuarios, con base en características de los agroecosistemas, relativas al clima, relieve, provincias de humedad, cobertura vegetal y nivel de tecnología empleada. Como resultado se obtuvieron 20 sistemas productivos entre agrícolas, agropecuarios, pecuarios y agroforestales, con lo cual se busca facilitar la planificación de la investigación y transferencia de tecnología de CORPOICA en el departamento. La información se procesó a partir de la configuración de una base de datos, mediante el Sistema de Información Georeferenciada SIG-ILWI