Controllable chirality-induced geometrical Hall effect in a frustrated highly-correlated metal

A current of electrons traversing a landscape of localized spins possessing non-coplanar magnetic order gains a geometrical (Berry) phase which can lead to a Hall voltage independent of the spin-orbit coupling within the material--a geometrical Hall effect. We show that the highly-correlated metal UCu5 possesses an unusually large controllable geometrical Hall effect at T<1.2K due to its frustration-induced magnetic order. The magnitude of the Hall response exceeds 20% of the \nu=1 quantum Hall effect per atomic layer, which translates into an effective magnetic field of several hundred Tesla acting on the electrons. The existence of such a large geometric Hall response in UCu5 opens a new field of inquiry into the importance of the role of frustration in highly-correlated electron materials.Comment: article and supplemental informatio

Implementación del Proyecto Planta de Alimentos para la Integración Social de la Universidad Nacional de La Plata (PAIS-UNLP)

En el marco de la crisis alimentaria global, durante el bienio 2016-2018 cerca de 14.2 millones de argentinos padecían inseguridad alimentaria, moderada o grave, valor que duplicaba lo registrado para el bienio anterior (FAO, 2019). En este aspecto el INDEC informó que, para 2021, existían en nuestro país casi 12 millones de personas por debajo de la línea de pobreza, de los cuales 3 millones se encontraban por debajo de la línea de indigencia. En la ciudad de La Plata, entre 2018 y 2019, el Consejo Social llevó adelante un relevamiento de Sitios de Distribución de Alimentos del Gran La Plata, encontrando también datos alarmantes: casi un 41% de la población por debajo de la línea de pobreza y un 13.5% por debajo de la línea de indigencia. Frente a este panorama, la Universidad Nacional de La Plata (UNLP) priorizó la necesidad de un accionar urgente planteando nuevas herramientas. Por este motivo, en el marco del Plan Argentina Contra el Hambre, en 2019, la UNLP puso a disposición toda su capacidad científica y técnica y se propuso como objetivo principal la creación de la Planta de Alimentos para la Integración Social (P.A.I.S) con el propósito de generar productos de alta calidad nutricional, de fácil acceso para las personas más vulnerables, que permitan articular las capacidades productivas del Cinturón Hortícola Platense fortaleciendo el sistema productivo local y en particular la cadena de valor alimentaria.Facultad de Ingenierí

Hydrogen bond networks determine emergent mechanical and thermodynamic properties across a protein family

<p>Abstract</p> <p>Background</p> <p>Gram-negative bacteria use periplasmic-binding proteins (bPBP) to transport nutrients through the periplasm. Despite immense diversity within the recognized substrates, all members of the family share a common fold that includes two domains that are separated by a conserved hinge. The hinge allows the protein to cycle between open (apo) and closed (ligated) conformations. Conformational changes within the proteins depend on a complex interplay of mechanical and thermodynamic response, which is manifested as an increase in thermal stability and decrease of flexibility upon ligand binding.</p> <p>Results</p> <p>We use a distance constraint model (DCM) to quantify the give and take between thermodynamic stability and mechanical flexibility across the bPBP family. Quantitative stability/flexibility relationships (QSFR) are readily evaluated because the DCM links mechanical and thermodynamic properties. We have previously demonstrated that QSFR is moderately conserved across a mesophilic/thermophilic RNase H pair, whereas the observed variance indicated that different enthalpy-entropy mechanisms allow similar mechanical response at their respective melting temperatures. Our predictions of heat capacity and free energy show marked diversity across the bPBP family. While backbone flexibility metrics are mostly conserved, cooperativity correlation (long-range couplings) also demonstrate considerable amount of variation. Upon ligand removal, heat capacity, melting point, and mechanical rigidity are, as expected, lowered. Nevertheless, significant differences are found in molecular cooperativity correlations that can be explained by the detailed nature of the hydrogen bond network.</p> <p>Conclusion</p> <p>Non-trivial mechanical and thermodynamic variation across the family is explained by differences within the underlying H-bond networks. The mechanism is simple; variation within the H-bond networks result in altered mechanical linkage properties that directly affect intrinsic flexibility. Moreover, varying numbers of H-bonds and their strengths control the likelihood for energetic fluctuations as H-bonds break and reform, thus directly affecting thermodynamic properties. Consequently, these results demonstrate how unexpected large differences, especially within cooperativity correlation, emerge from subtle differences within the underlying H-bond network. This inference is consistent with well-known results that show allosteric response within a family generally varies significantly. Identifying the hydrogen bond network as a critical determining factor for these large variances may lead to new methods that can predict such effects.</p

Kwapa: Gente del río. Estrategias transmedia de impacto social

En este reporte se encuentra toda la documentación del trabajo realizado durante el período de otoño 2022 dentro del proyecto de aplicación profesional Alter Código en el cual se siguió trabajando en la realización del videojuego “A orillas del río” y en la producción del documental de etnoficción “Déjennos pescar”. En el documental etnoficción se tuvo como objetivo principal el rodaje en comunidades cucapá en Baja California, a partir de esto se implementaron diversas estrategias para lograrlo. Como resultado de lo anterior, se abrió un crowdfunding junto con una estrategia de difusión en redes sociales que incluyó, además, la participación en el festival universitario y la producción de stickers para lograr mayor impacto. En el videojuego el objetivo principal consistió en desarrollar una demo jugable cuyo resultado deja definida una dirección concreta para continuar a futuro. Además, permite mostrar las herramientas que se van a implementar como tomar objetos, seleccionar, agarrar e interactuar entre personajes y el entorno. En términos de colaboración se creó un cuadernillo ilustrado para mostrar a niños y adolescentes cucapá y, de este modo, sentar las bases de retroalimentación respecto al desarrollo de la historia y diseño de personajes. Por último, el viaje de producción proveyó de material para seguir desarrollando eldocumental, al mismo tiempo que permitió al equipo de videojuego sentar las bases de una retroalimentación con base en una metodología, desde la perspectiva emic, en la que nuestros colaboradores son co-productores del sentido.ITESO, A.C

Performance of a malaria microscopy image analysis slide reading device.

BACKGROUND: Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a "device" consisting of a microscope, a scanner, and a computer algorithm) that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. METHODS: The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization ("WHO55" test), and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test). These subjects' blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n = 119. RESULTS: On the WHO55 test, the device scored a "Level 4" using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. CONCLUSIONS: In its current manifestation, the device performs at a level comparable to that of many human slide readers. Because its use requires minimal additional equipment and it uses standard stained slides as starting material, its widespread adoption may eliminate the current uncertainty about the quality of microscopic diagnoses worldwide