Design of two-dimensional particle assemblies using isotropic pair interactions with an attractive well

Using ground-state and relative-entropy based inverse design strategies, isotropic interactions with an attractive well are determined to stabilize and promote as- sembly of particles into two-dimensional square, honeycomb, and kagome lattices. The design rules inferred from these results are discussed and validated in the dis- covery of interactions that favor assembly of the highly open truncated-square and truncated-hexagonal lattices.Comment: 11 pages, 5 figures and supplemental materia

Algunas reflexiones en torno a la salud de comunidades indígenas

La población indígena en Colombia asciende a aproximadamente 600.000 individuos, repartidos en 87 etnias diferentes, que a pesar de ser distintas entre sí, tienen en común su origen amerindio y constituyen un sector social definido, La mayor parte de la población indígena del país habita áreas de muy baja densidad poblacional y, de acuerdo con su localización geográfica, el Departamento Nacional de Planeación los ha clasificado como habitantes de cuatro macroregiones, a saber: selva, sabana, región andina y península guajira: A pesar de pertenecer a tan diverso número de etnias y de habitar en regiones con características ecológicas tan distintas que influyen en el comportamiento epidemiológico de las enfermedades, se observa, en términos generales, una alta frecuencia de enfermedades infecciosas respiratorias y gastrointestinales, así como enfermedades transmisibles, desnutrición, problemas perinatales y patologías orales. Aunque se desconoce la real magnitud de dichos problemas, en general, podemos afirmar que la situación de salud en las comunidades indígenas es crítica y preocupante. Se mencionan a continuación una serie de factores y circunstancias que inciden o están relacionados con esta crítica situación y que podemos generalizar para la gran mayoría de comunidades indígenas del país

Functional characterization and discovery of modulators of SbMATE, the agronomically important aluminium tolerance transporter from Sorghum bicolor.

About 50% of the world's arable land is strongly acidic (pH ≤ 5). The low pH solubilizes root-toxic ionic aluminium (Al3+) species from clay minerals, driving the evolution of counteractive adaptations in cultivated crops. The food crop Sorghum bicolor upregulates the membrane-embedded transporter protein SbMATE in its roots. SbMATE mediates efflux of the anionic form of the organic acid, citrate, into the soil rhizosphere, chelating Al3+ ions and thereby imparting Al-resistance based on excluding Al+3 from the growing root tip. Here, we use electrophysiological, radiolabeled, and fluorescence-based transport assays in two heterologous expression systems to establish a broad substrate recognition profile of SbMATE, showing the proton and/or sodium-driven transport of 14C-citrate anion, as well as the organic monovalent cation, ethidium, but not its divalent analog, propidium. We further complement our transport assays by measuring substrate binding to detergent-purified SbMATE protein. Finally, we use the purified membrane protein as an antigen to discover native conformation-binding and transport function-altering nanobodies using an animal-free, mRNA/cDNA display technology. Our results demonstrate the utility of using Pichia pastoris as an efficient eukaryotic host to express large quantities of functional plant transporter proteins. The nanobody discovery approach is applicable to other non-immunogenic plant proteins

Eye drop Self-medication: Comparative Questionnaire-based study of two Latin American cities.

A broad spectrum of ocular symptoms are treated by self-medication with commercial eye-drops.  This behavior threatens individuals' visual health. In Latin America, evidence is poor. Objective:  To  detect,  characterize  and  compare  patterns  of  ophthalmic  self-medication  between  Córdoba (Argentina) and Barranquilla (Colombia).Design:  Analytic, cross-sectional and comparative population-based study. Setting: Two private tertiary care ophthalmology centers from Córdoba, Argentina, and Barranquilla, Colombia.Participants:  Patients 18 years of age or older who consulted for the first time in this two institutions duringAugust-November 2009, were included. A number of 570 patients were enrrolled.Methods:  Data collected through a semi-structured questionnaire. Main outcome measure: To determine thefrequency of self-medication with eyedrops on a specific population of two cities in Latin America.Results:  Comparable  rates  of  ocular  self-medication  were  found  (25.6%  and  25.7%  for  Cordoba  and Barranquilla, respectively). The percentage of men and women who self-medicated was not significantly different between both samples. The major source of eye drops recommendation in the Argentineans patients was the pharmacist (31%); while the social source was predominant in Colombian individuals (53%). In Cordoba, the most frequently used product was a non-steroidal anti-inflammatory drop in combination with a vasoconstrictive agent (32%); while in Barranquilla, antibiotic eye drops were preferred (33%). Self-medication was higher between the ages of 31 and 50 years old in Argentinean citizens (28%) and between 18 to 31 years old in the Colombiancommunity (39%). This habit was found mostly in patients who completed university studies in Cordoba (33%); in Barranquilla, individuals with lower educational level practice more this behavior (36%).Conclusion:  In both populations, patients commonly treat ocular conditions by self-medicating. Currently, anincreasing number of eye drops are obtainable without prescription and a high percentage of self-medicated patients in both samples ignore the possible side effects of the used medication.Fil: Marquez, Gabriel. Fundación VER; ArgentinaFil: Hildegard Piñeros-Heilbron. Fundación Oftalmológica del Caribe; ColombiaFil: Sanchez, Victoria M.. Fundación VER; ArgentinaFil: Torres, Victor Eduardo Roque. Fundación VER; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Gramajo, Ana L.. Fundación VER; ArgentinaFil: Juarez, Claudio P.. Fundación VER; Argentina. Fundación Oftalmológica del Caribe; ColombiaFil: Peña, Fernando. Fundación Oftalmológica del Caribe; ColombiaFil: Luna, José D.. Fundación VER; Argentin

A Versatile, Portable Intravital Microscopy Platform for Studying Beta-cell Biology In Vivo

The pancreatic islet is a complex micro-organ containing numerous cell types, including endocrine, immune, and endothelial cells. The communication of these systems is lost upon isolation of the islets, and therefore the pathogenesis of diabetes can only be fully understood by studying this organized, multicellular environment in vivo. We have developed several adaptable tools to create a versatile platform to interrogate β-cell function in vivo. Specifically, we developed β-cell-selective virally-encoded fluorescent protein biosensors that can be rapidly and easily introduced into any mouse. We then coupled the use of these biosensors with intravital microscopy, a powerful tool that can be used to collect cellular and subcellular data from living tissues. Together, these approaches allowed the observation of in vivo β-cell-specific ROS dynamics using the Grx1-roGFP2 biosensor and calcium signaling using the GcAMP6s biosensor. Next, we utilized abdominal imaging windows (AIW) to extend our in vivo observations beyond single-point terminal measurements to collect longitudinal physiological and biosensor data through repeated imaging of the same mice over time. This platform represents a significant advancement in our ability to study β-cell structure and signaling in vivo, and its portability for use in virtually any mouse model will enable meaningful studies of β-cell physiology in the endogenous islet niche

Emerging pleiotropic mechanisms underlying aluminum resistance and phosphorus acquisition on acidic soils.

Aluminum (Al) toxicity on acidic soils significantly damages plant roots and inhibits root growth. Hence, crops intoxicated by Al become more sensitive to drought stress and mineral nutrient deficiencies, particularly phosphorus (P) deficiency, which is highly unavailable on tropical soils. Advances in our understanding of the physiological and genetic mechanisms that govern plant Al resistance have led to the identification of Al resistance genes, both in model systems and in crop species. It has long been known that Al resistance has a beneficial effect on crop adaptation to acidic soils. This positive effect happens because the root systems of Al resistant plants show better development in the presence of soil ionic Al3C and are, consequently, more efficient in absorbing sub-soil water and mineral nutrients. This effect of Al resistance on crop production, by itself, warrants intensified efforts to develop and implement, on a breeding scale, modern selection strategies to profit from the knowledge of the molecular determinants of plant Al resistance. Recent studies now suggest that Al resistance can exert pleiotropic effects on P acquisition, potentially expanding the role of Al resistance on crop adaptation to acidic soils. This appears to occur via both organic acid (OA)- and non-OA transporters governing a joint, iron-dependent interplay between Al resistance and enhanced P uptake, via changes in root system architecture. Current research suggests this interplay to be part of a P stress response, suggesting that this mechanism could have evolved in crop species to improve adaptation to acidic soils. Should this pleiotropism prove functional in crop species grown on acidic soils, molecular breeding based on Al resistance genes may have a much broader impact on crop performance than previously anticipated. To explore this possibility, here we review the components of this putative effect of Al resistance genes on P stress responses and P nutrition to provide the foundation necessary to discuss the recent evidence suggesting pleiotropy as a genetic linkage between Al resistance and P efficiency. We conclude by exploring what may be needed to enhance the utilization of Al resistance genes to improve crop production on acidic soils.Article 1420

The burden of cutaneous melanoma and status of preventive measures in Central and South America

Rationale and objective Very little is known about the burden of cutaneous melanoma in Central and South America, despite the existence of a reasonable amount of population-based data. We present data on melanoma incidence calculated in a standardized way for Central and South America, as well as an overview of primary and secondary prevention issues in the region. Methods Cancer registry data on all incident cases reported in the different registries present in Central and South America were combined to provide registry-based country estimates of age-standardized, sex-specific cutaneous melanoma incidence overall, and by histological subtype and anatomical site. A literature search provided additional information. Results Age-standardized incidence rates were between 1 and 5 per 100,000 and tended to be higher further away from the equator. Cutaneous melanomas of the acral type, mostly occurring on the lower limbs, are a distinguishing feature of melanoma in Central and South America in comparison with high-incidence areas. Several preventive measures, both primary and secondary, are in place, albeit largely without evaluation. Conclusion Due to incomplete registration and different registration practices, reliable and comparable data on melanoma were difficult to obtain; thus it is likely that the true burden of melanoma in Central and South America has been underestimated. The different characteristics of the cutaneous melanoma patient population in terms of anatomical site and histological type distribution imply a need for adapted primary and secondary prevention measures. The generally high ambient ultraviolet radiation levels require sufficient sun protection measures