Role of SOS1 in potassium nutrition

Comunicación oral presentada al FESPB celebrado del 4-9 de julio, 2010, en Valencia, España.Peer reviewe

Self-consistent MHD simulation of jet launching in a neutron star - white dwarf merger

The merger of a white dwarf (WD) and a neutron star (NS) is a relatively common event that will produce an observable electromagnetic signal. Furthermore, the compactness of these stellar objects makes them an interesting candidate for gravitational wave (GW) astronomy, potentially being in the frequency range of LISA and other missions. To date, three-dimensional simulations of these mergers have not fully modelled the WD disruption, or have used lower resolutions and have not included magnetic fields even though they potentially shape the evolution of the merger remnant. In this work, we simulate the merger of a 1.4$M_\odot$ NS with a 1$M_\odot$ carbon oxygen WD in the magnetohydrodynamic moving mesh code \AREPO. We find that the disruption of the WD forms an accretion disk around the NS, and the subsequent accretion by the NS powers the launch of strongly magnetized, mildly relativistic jets perpendicular to the orbital plane. Although the exact properties of the jets could be altered by unresolved physics around the NS, the event could result in a transient with a larger luminosity than kilonovae. We discuss possible connections to fast blue optical transients (FBOTs) and long-duration gamma-ray bursts. We find that the frequency of GWs released during the merger is too high to be detectable by the LISA mission, but suitable for deci-hertz observatories such as LGWA, BBO or DECIGO.Comment: Accepted for publication in A&A. 13 pages, 11 figure

Assessing a Pilot Scheme of Intensive Support and Assertive Linkage in Levels of Engagement, Retention, and Recovery Capital for People in Recovery Housing using Quasi-Experimental Methods

Introduction: Strong and ever-growing evidence highlights the effectiveness of recovery housing in supporting and sustaining substance use disorder (SUD) recovery, especially when augmented by intensive support that includes assertive linkages to community services. This study aims to evaluate a pilot intensive recovery support (IRS) intervention for individuals (n=175) entering certified Level II and III recovery residences. These individuals met at least three out of five conditions (no health insurance; no driving license; substance use in the last 14 days; current unemployment; possession of less than $75 capital). The study assesses the impact of the IRS on engagement, retention, and changes in recovery capital, compared to the business-as-usual Standard Recovery Support (SRS) approach (n=1,758). Methods: The study employed quasi-experimental techniques to create weighted and balanced counterfactual groups. These groups, derived from the Recovery Capital (REC-CAP) assessment tool, enabled comparison of outcomes between people receiving IRS and those undergoing SRS. Results: After reweighting for resident demographics, service needs, and barriers to recovery, those receiving IRS exhibited improved retention rates, reduced likelihood of disengagement, and growth in recovery capital after living in the residence for 6-9 months. Conclusion: The results from this pilot intervention indicate that intensive recovery support, which integrates assertive community linkages and enhanced recovery coaching, outperforms a balanced counterfactual group in engagement, length of stay, and recovery capital growth. We suggest that this model may be particularly beneficial to those entering Level II and Level III recovery housing with lower levels of recovery capital at admission

Estandarización de la técnica de aglutinación directa para el inmunodiagnóstico de la enfermedad de Chagas

Introduction: Chagas’ disease is caused by the parasite Trypanosoma cruzi and its immunological diagnosis is mainly based on the detection of antibodies against T. cruzi using tests such as the ELISA, the indirect fluorescence antibody test (IFAT) and the indirect hemagglutination test (IHAT). The main disadvantage of the IHAT is the need to prepare sheep erythrocytes, whose availability is limited and they have a short duration once prepared. However, there are alternative tests, such as the direct agglutination test (DAT).Objective: To standardize the direct agglutination test for the diagnosis of Chagas disease.Materials and methods: Trypanosoma cruzi epimastigotes were prepared using two protocols, with and without trypsin treatment. The parasites were stained and optimal conditions for parasitic concentration and serum dilutions were determined. We evaluated the technique using sera from patients with Chagas disease, from healthy individuals and from individuals with other parasitic diseases.Results: The optimal parasitic concentration was 500 x 106 parasites/ml using stained parasites without trypsin treatment. The optimal serum dilutions were 1/25, 1/50 y 1/100 and the cut-off point was the 1/50 dilution. The diagnostic indices for the standardized technique were as follows: Sensitivity, 94.3% (95% CI: 79.5-99.0) and specificity, 96.3% (95% CI: 88.8-99.0), with positive and negative predictive values of 91.7% (95% CI: 76.4-97.8) and 97.5% (95% CI: 90.4-99.6), respectively. Cross-reaction was observed only in three sera from individuals with visceral leishmaniasis. The results were compared with those obtained by IHA, ELISA, and IFA, and the concordance rate was 96% and the kappa index, 0.90 (95% CI: 0.81-0.99).Conclusion: The standardized direct agglutination test could be useful for immunodiagnosis of Chagas disease.Introducción. La enfermedad de Chagas es causada por el parásito Trypanosoma cruzi y su diagnóstico inmunológico se basa principalmente en la detección de anticuerpos contra T. cruzi mediante pruebas tales como ELISA, inmunofluorescencia indirecta (IFI) y hemaglutinación indirecta (HAI). Esta última tiene el inconveniente de requerir la preparación de eritrocitos de carnero, difíciles de obtener y de poca duración. Sin embargo, existen pruebas alternativas, como la técnica de aglutinación directa.Objetivo. Estandarizar la técnica de aglutinación directa para el diagnóstico de la enfermedad de Chagas.Materiales y métodos. Se prepararon parásitos epimastigotes de T. cruzi mediante dos protocolos, con tratamiento con tripsina y sin él. Los parásitos se colorearon, y se determinaron las condiciones óptimas de concentración parasitaria y diluciones de suero. Se utilizaron sueros de pacientes con enfermedad de Chagas, de individuos sanos y con otras parasitosis.Resultados. La concentración parasitaria óptima fue de 500 x106 parásitos/ml, utilizando parásitos coloreados y sin tratamiento con tripsina. Las diluciones de suero óptimas fueron de 1/25, 1/50 y1/100, y el punto de corte, la dilución de 1/50. La técnica estandarizada mostró índices diagnósticos de sensibilidad de 94,3 % (IC95% 79,5-99,0) y de especificidad de 96,3 % (IC95% 88,8-99,0); se encontró reacción cruzada en tres sueros de individuos con leishmaniasis visceral, con valores pronósticos positivo y negativo de 91,7 % (IC95% 76,4-97,8) y de 97,5 % (IC95% 90,4-99,6), respectivamente. Se compararon los resultados con los obtenidos por HAI, ELISA e IFI y la concordancia fue de 96 % con un índice kappa de 0,90 (IC95% 0,81-0,99).Conclusión. La técnica de aglutinación directa estandarizada podría ser útil para el inmunodiagnóstico de la enfermedad de Chagas

Active proton efflux, nutrient retention and boron-bridging of pectin are related to greater tolerance of proton toxicity in the roots of two <i>Erica </i>species

36 páginas.-- 6 figuras.-- 2 tablas.-- 50 referencias.-- Appendix A. The supplementary data related to this article is https://doi.org/10.1016/j.plaphy.2018.02.029Background and aims: Tolerance to soil acidity was studied in two species of Ericaceae that grow in mine-contaminated soils (S Portugal, SW Spain) to find out if there are interspecific variations in H+ tolerance which might be related to their particular location. Methods: Tolerance to H+ toxicity was tested in nutrient solutions using seeds collected in SW Spain. Plant growth and nutrient contents in leaves, stems and roots were determined. Viability tests and proton exchange were studied in roots exposed, short-term, to acidic conditions. Membrane ATPase activity and the cell-wall pectic polysaccharide domain rhamnogalacturonan-II (RG-II) were analysed to find out interspecific differences. Results: Variation in survival, growth and mineral composition was found between species. The H+-tolerant species (Erica andevalensis) showed greater concentration of nutrients than E. australis. Very low pH (pH 2) produced a significant loss of root nutrients (K, P, Mg) in the sensitive species. Root ATPase activity was slightly higher in the tolerant species with a correspondingly greater H+ efflux capacity. In both species, the great majority of the RG-II domains were in their boron-bridged dimeric form. However, shifting to a medium of pH 2 caused some of the boron bridges to break in the sensitive species. Conclusions: Variation in elements linked to the cell wall-membrane complex and the stability of their components (RG-II, H+-ATPases) are crucial for acid stress tolerance. Thus, by maintaining root cell structure, active proton efflux avoided toxic H+ build-up in the cytoplasm and supported greater nutrient acquisition in H+-tolerant species.This work was partially granted by MICINN contract CGL2006/02860 and by Fundación Areces. SCF thanks the BBSRC (UK; grant reference BB/H000690/1) and DS thanks the Comisión Nacional de Investigación Científica y Tecnológia (Conicyt; Chile) for financial support.Peer reviewe

OMEGA: a software tool for the management, analysis, and dissemination of intracellular trafficking data that incorporates motion type classification and quality control [preprint]

MOTIVATION: Particle tracking coupled with time-lapse microscopy is critical for understanding the dynamics of intracellular processes of clinical importance. Spurred on by advances in the spatiotemporal resolution of microscopy and automated computational methods, this field is increasingly amenable to multi-dimensional high-throughput data collection schemes (Snijder et al, 2012). Typically, complex particle tracking datasets generated by individual laboratories are produced with incompatible methodologies that preclude comparison to each other. There is therefore an unmet need for data management systems that facilitate data standardization, meta-analysis, and structured data dissemination. The integration of analysis, visualization, and quality control capabilities into such systems would eliminate the need for manual transfer of data to diverse downstream analysis tools. At the same time, it would lay the foundation for shared trajectory data, particle tracking, and motion analysis standards. RESULTS: Here, we present Open Microscopy Environment inteGrated Analysis (OMEGA), a cross-platform data management, analysis, and visualization system, for particle tracking data, with particular emphasis on results from viral and vesicular trafficking experiments. OMEGA provides easy to use graphical interfaces to implement integrated particle tracking and motion analysis workflows while keeping track of error propagation and data provenance. Specifically, OMEGA: 1) imports image data and metadata from data management tools such as Open Microscopy Environment Remote Objects (OMERO; Allan et al., 2012); 2) tracks intracellular particles moving across time series of image planes; 3) facilitates parameter optimization and trajectory results inspection and validation; 4) performs downstream trajectory analysis and motion type classification; 5) estimates the uncertainty associated with motion analysis; and, 6) facilitates storage and dissemination of analysis results, and analysis definition metadata, on the basis of our newly proposed Minimum Information About Particle Tracking Experiments (MIAPTE; Rigano & Strambio-De-Castillia, 2016; 2017) guidelines in combination with the OME-XML data model (Goldberg et al, 2005)

Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela