Twisted Nano-optics: Manipulating Light at the Nanoscale with Twisted Phonon Polaritonic Slabs

Recent discoveries have shown that when two layers of van der Waals (vdW) materials are superimposed with a relative twist angle between their respective in-plane principal axes, the electronic properties of the coupled system can be dramatically altered. Here, we demonstrate that a similar concept can be extended to the optics realm, particularly to propagating polaritons, hybrid light-matter interactions. To do this, we fabricate stacks composed of two twisted slabs of a polar vdW crystal (MoO3) supporting low-loss anisotropic phonon polaritons (PhPs), and image the propagation of the latter when launched by localized sources (metal antennas). Our images reveal that under a critical angle the PhPs isofrequency curve (determining the PhPs momentum at a fixed frequency) undergoes a topological transition. Remarkably, at this angle, the propagation of PhPs is strongly guided along predetermined directions (canalization regime) with no geometrical spreading (diffraction-less). These results demonstrate a new degree of freedom (twist angle) for controlling the propagation of polaritons at the nanoscale with potential for nano-imaging, (bio)-sensing, quantum applications and heat management

Proyecto final fase 10 presentar y sustentar proyecto final

Identifica el estado actual de la empresa objeto de estudio, con respecto al análisis de la herramienta del modelo referencial. Comprende como el modelo referencial recoge las tendencias internacionales en Logística, plasmadas en la literatura especializada, en encuentros científicos y técnicos y, en las experiencias conocidas en investigaciones realizadas en Colombia, en Norteamérica y Europa. Analiza como el desarrollo de los procesos de globalización e internacionalización de la economía, exige que los sistemas logísticos colombianos alcancen niveles de competitividad similares al de las empresas de clase mundial, porque en últimas, es con ellas con quienes se debe competir. Identifica cada proceso que compone el Supply Chain de la empresa Lácteos del Cesar Klarens S.A., así como sus fortalezas y debilidades. Realiza propuestas de mejoras a cada uno de los procesos identificados, así como planteamientos de nuevas estrategias.Identifies the current status of the company under study, with respect to the analysis of the Referential Model tool. It understands how the Reference Model gathers the international tendencies in Logistics, reflected in the specialized literature, in scientific and technical meetings and, in the known experiences in research carried out in Colombia, in North America and Europe. Analyze how the development of the processes of globalization and internationalization of the economy, requires that Colombian logistics systems reach levels of competitiveness similar to that of world-class companies, because ultimately, it is with them that they must compete. Identify each process that makes up the Supply Chain of the Dairy Company of Cesar Klarens S.A. , as well as their strengths and weaknesses. Make proposals for improvements to each of the identified processes, as well as approaches to new strategies

Manganese Inhalation Induces Dopaminergic Cell Loss: Relevance to Parkinson’s Disease

Parkinson’s disease (PD) experimental models are crucial in the assessment of possible therapies. Nevertheless, even though PD was one of the first neurodegenerative conditions to be modeled, there are limitations such as spontaneous recovery; lack of bilateral damage, which is a PD characteristic; animal intensive care after neurotoxin administration; and ultrastructural and biochemical nonspecific alterations but mostly the neurodegenerative time course observed in humans. In this chapter, we investigated the effects of divalent and trivalent manganese inhalation on rats and mice to obtain a novel PD animal model inducing bilateral and progressive dopaminergic cell death. We found that after 5 or 6 months of inhalation, there was more than 70% decrease in the number of TH-immunopositive neurons, and these alterations are correlated with an evident motor performance deficits manifested as akinesia, postural instability, and action tremor. More interesting is the fact that these alterations were reverted with l-DOPA treatment, implying that the motor alterations are associated with nigrostriatal dopaminergic innervation, postulating new light for the understanding of manganese neurotoxicity as an appropriate PD experimental model. Our results are contributing to the development of a suitable PD animal model, reproducible, sensitive, time-efficient, and readily applicable behavioral tests

Burnout Among First-Year Medical Students During COVID-19 Pandemic in Mexico: A Cross-Sectional Study

Background: The coronavirus pandemic is an international public health emergency without precedence in modern history. It represents a challenge to students’ academic and psychological stability due to the changes it caused in daily life. This study aimed to evaluate the prevalence and level of burnout in medical students caused by the academic and psychological instability that the pandemic represents. Methods: A prospective cross-sectional study was designed using the Maslach Burnout Inventory-Student Survey (MBI-SS). This evaluated the emotional exhaustion due to study demands, cynicism, and negative self-academic efficacy. This study was based in the school of medicine of the Universidad Autonoma de Nuevo Leon (UANL) in Monterrey, Mexico, during the Spring semester of 2020. Results: A total of 154 (93 women and 61 men) first-year medical students participated (response rate of 36.4%). Burnout was identified in 14.9% (n=23), and high emotional exhaustion in 53.9% (n=83). Burnout was almost 4 times more likely to develop in men than in women (aOR = 4.8; 95% Confidence Interval=1.7-13.3) when considering age as a covariable in the multivariable model. Conclusion: Further epidemiological studies of burnout syndrome in medical students are needed, and schools should consider promoting mental health and making programs available for their students to help overcome the emotional and social challenges during the pandemic

Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution

P. 1-14The relation between gestational age and foetal death risk in ovine toxoplasmosis is already known, but the mechanisms involved are not yet clear. In order to study how the stage of gestation influences these mechanisms, pregnant sheep of the same age and genetic background were orally dosed with 50 oocysts of Toxoplasma gondii (M4 isolate) at days 40 (G1), 90 (G2) and 120 (G3) of gestation. In each group, four animals were culled on the second, third and fourth week post infection (pi) in order to evaluate parasite load and distribution, and lesions in target organs. Ewes from G1 showed a longer period of hyperthermia than the other groups. Abortions occurred in all groups. While in G2 they were more frequent during the acute phase of the disease, in G3 they mainly occurred after day 20 pi. After challenge, parasite and lesions in the placentas and foetuses were detected from day 19 pi in G3 while in G2 or G1 they were only detected at day 26 pi. However, after initial detection at day 19 pi, parasite burden, measured through RT-PCR, in placenta or foetus of G3 did not increase significantly and, at in the third week pi it was lower than that measured in foetal liver or placenta from G1 to G3 respectively. These results show that the period of gestation clearly influences the parasite multiplication and development of lesions in the placenta and foetus and, as a consequence, the clinical course in ovine toxoplasmosis.S

Perspectivas del sistema agroalimentario regional

Esta publicación constituye una primera aproximación al abordaje sistémico y de la complejidad del sistema agroalimentario regional. La publicación aborda la evolución y trayectoria de los sistemas agroalimentarios y su sustentabilidad, caracteriza las tendencias y cambios globales, analiza las configuraciones locales y regionales de las tendencias, ensaya sobre las políticas públicas situadas del sistema agroalimentario regional, y toma posición sobre cómo construir un sistema agroalimentario sostenible. El documento busca presentar una serie de interrogantes estratégicos sobre los desafíos de la gestión territorial rural para potenciar y promover la seguridad alimentaria. El texto brinda ideas y conceptos para reflexionar y debatir sobre la sustentabilidad futuro del sistema agroalimentario regional de Mendoza y de San Juan.EEA MendozaFil: Perez, Martin Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; ArgentinaFil: Silva Colomer, Jorge. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Mussetta, Paula Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Hernandez, Juan Jesus. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; ArgentinaFil: Rodriguez Ibañez, Yanina Griselda. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región Cuyo (IPAF); ArgentinaFil: Cueto, Walter. Universidad Nacional de Cuyo; ArgentinaFil: Dalmasso, Caterina. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Mendoza San Juan; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil. Vitale Gutierrez, Javier Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Mendoza San Juan; ArgentinaFil: Alvarez, Juan Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina.Fil: Sales, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Investigaciones de Zonas Aridas; ArgentinaFil: Quagliariello, Roxana Gaby. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Junín; Argentin

Non-productive angiogenesis disassembles Aß plaque-associated blood vessels

The human Alzheimer’s disease (AD) brain accumulates angiogenic markers but paradoxically, the cerebral microvasculature is reduced around Aß plaques. Here we demonstrate that angiogenesis is started near Aß plaques in both AD mouse models and human AD samples. However, endothelial cells express the molecular signature of non-productive angiogenesis (NPA) and accumulate, around Aß plaques, a tip cell marker and IB4 reactive vascular anomalies with reduced NOTCH activity. Notably, NPA induction by endothelial loss of presenilin, whose mutations cause familial AD and which activity has been shown to decrease with age, produced a similar vascular phenotype in the absence of Aß pathology. We also show that Aß plaque-associated NPA locally disassembles blood vessels, leaving behind vascular scars, and that microglial phagocytosis contributes to the local loss of endothelial cells. These results define the role of NPA and microglia in local blood vessel disassembly and highlight the vascular component of presenilin loss of function in AD

Chimeric camel/human heavy-chain antibodies protect against MERS-CoV infection

Middle East respiratory syndrome coronavirus (MERS-CoV) continues to cause outbreaks in humans as a result of spillover events from dromedaries. In contrast to humans, MERS-CoV–exposed dromedaries develop only very mild infections and exceptionally potent virus-neutralizing antibody responses. These strong antibody responses may be caused by affinity maturation as a result of repeated exposure to the virus or by the fact that dromedaries—apart from conventional antibodies—have relatively unique, heavy chain–only antibodies (HCAbs). These HCAbs are devoid of light chains and have long complementarity-determining regions with unique epitope binding properties, allowing them to recognize and bind with high affinity to epitopes not recognized by conventional antibodies. Through direct cloning and expression of the variable heavy chains (VHHs) of HCAbs from the bone marrow of MERS-CoV–infected dromedaries, we identified several MERS-CoV–specific VHHs or nanobodies. In vitro, these VHHs efficiently blocked virus entry at picomolar concentrations. The selected VHHs bind with exceptionally high affinity to the receptor binding domain of the viral spike protein. Furthermore, camel/human chimeric HCAbs—composed of the camel VHH linked to a human Fc domain lacking the CH1 exon—had an extended half-life in the serum and protected mice against a lethal MERS-CoV challenge. HCAbs represent a promising alternative strategy to develop novel interventions not only for MERS-CoV but also for other emerging pathogens.info:eu-repo/semantics/publishedVersio

Relevamiento de opinión sobre la actividad ovina en la Patagonia

La prospectiva ofrece, la posibilidad de pensar de manera estructurada y sistémica sobre el futuro. Explora los cambios a través de la identificación de fuerzas impulsoras, invariantes estratégicas, incertidumbres críticas y apoya la toma de decisión en el presente en vista de los futuros posibles. La prospectiva nos ayuda a construir el futuro, nos invita a considerarlo como algo a crear, y no como algo ya definido a predecir. Por medio de un análisis prospectivo al 2030 de la actividad ovina en la Patagonia Argentina se intentan definir escenarios que permitan orientar las políticas públicas. En ese sentido se espera construir dos tipos de escenarios: el tendencial que intenta recoger hacia dónde va el sector si todo sigue como hasta ahora y otro escenario deseado que tenga como rasgos identitarios ser alcanzable y compartido entre los actores involucrados en este sistema de producción. En pos de aportar en la construcción de un futuro mejor para la actividad en la región es que el mayor esfuerzo se pondrá en la consolidación de un escenario deseado. Para contar con la información necesaria para empezar a delinear ese futuro deseable, se reunió un grupo de técnicos de la Institución que diseñó un esquema de trabajo donde se tuvo en cuenta la metodología utilizada para estos estudios y las características del caso específico a estudiar. El primer evento realizado fue el Seminario virtual ¡Hablemos del ovino y su futuro! en agosto de 2021. Este evento sirvió como puntapié para trabajar la determinación del “árbol de problemas” y la definición de las “variables” y “procesos críticos” que afectan la actividad ovina en la Patagonia argentina. El diagnóstico del equipo de trabajo identificó como principales problemas y desafíos: 1) Caída continua de las existencias ganaderas ovinas, 2) Nuevas demandas asociadas a la calidad de producto (“productos éticos/sustentables”), 3) consolidación de la demanda de lanas finas y superfinas como una fibra “Premium” 4) demanda en forma creciente de un animal de mayor peso en el mercado internacional de carne, 5) problema de “escala” para la adopción de tecnologías, 6) Falta de organización e integración de las cadenas de carne y lana, 7) Escasas políticas públicas permanentes, más allá de Ley Ovina, Prolana y Planes sanitarios, 8) Factores externos como el cambio climático, la pandemia del COVID 19, nuevas tecnologías de las comunicaciones y mejoras en la calidad de servicios urbanos. En la continuidad de la tarea es que se realiza esta consulta sectorial, para ampliar la perspectiva del equipo de trabajo y tener una mejor comprensión de la problemática con la opinión de diferentes actores sociales.EEA ChubutFil: Pena, Sergio Osvaldo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Saavedra, Osvaldo Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Dirección Nacional. Centro de Investigación en Economía y Prospectiva (CIEP); ArgentinaFil: La Torraca, Andres Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Bain, Ingrid. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Vozzi, Pedro Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Muñoz, Marcelo Mirco. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Buono, Gustavo Gabriel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Elvira, Mario Gonzalo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Cariac, German. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Valle Inferior del Río Negro; ArgentinaFil: Alvarez, Juan Mauricio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Valle Inferior del Río Negro; ArgentinaFil: Conterno, Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Giovannini, Nicolas. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Alonso, Ignacio Agustin. Instituto Nacional de Tecnología Agropecuaria (INTA). Dirección Nacional. Centro de Investigación y Desarrollo Tecnológico para la Agricultura Familiar (CIPAF); ArgentinaFil: Barrera, Debora. Instituto Nacional de Tecnología Agropecuaria (INTA). Dirección Nacional Asistente Planificación, Monitoreo y Evaluación. Gerencia Monitoreo y Evaluación; ArgentinaFil: Tarraborelli, Diego. Universidad Nacional de Quilmes; ArgentinaFil: Vitale Gutierrez, Javier Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Mendoza - San Juan; ArgentinaFil: Gauna, Diego Hernan. Instituto Nacional de Tecnología Agropecuaria (INTA). Dirección Nacional. Centro de Investigación en Economía y Prospectiva (CIEP); Argentin