Time representation in reinforcement learning models of the basal ganglia

Reinforcement learning (RL) models have been influential in understanding many aspects of basal ganglia function, from reward prediction to action selection. Time plays an important role in these models, but there is still no theoretical consensus about what kind of time representation is used by the basal ganglia. We review several theoretical accounts and their supporting evidence. We then discuss the relationship between RL models and the timing mechanisms that have been attributed to the basal ganglia. We hypothesize that a single computational system may underlie both RL and interval timing—the perception of duration in the range of seconds to hours. This hypothesis, which extends earlier models by incorporating a time-sensitive action selection mechanism, may have important implications for understanding disorders like Parkinson's disease in which both decision making and timing are impaired

Modelling the Effect of Maize Silage and Winter Oat Forage Crop on Cow-Calf Systems in Argentina

Cow-calf systems in the flooding Pampa - Argentina, are facing increasing competition with cropping systems for resources and land. In this context, to be more competitive livestock systems require system intensification, which demands an improvement on the feedbase. Forage crops and feeding silage have been used widely on dairy and beef cattle finishing systems. The purpose of the study was to assess with a model the level of intensification that can be achieved in cow calf systems and its economic effects by incorporating maize silage and winter grazing oat crops

Oral Azithromycin for Treatment of Intractable Rosacea

Rosacea is a common chronic cutaneous disorder that primarily occurs on the convex surfaces of the central face and is often characterized by exacerbations and remissions. A case of a 52-yr-old woman visited our clinic in February 2008 complaining typical features of rosacea including multiple pinhead to rice-sized erythematous papules. We applied various conventional treatments including topical benzoyl peroxide and metronidazole as well as oral metronidazole, isotretinoin, and doxycycline. The lesions were not controlled but were rather aggravated by complications from these treatments. Therefore, we prescribed oral azithromycin, which has anti-inflammatory effects and reduces reactive oxygen species. Ten weeks after the administration of oral azithromycin, 500 mg per day for 2 weeks, the lesions had mostly disappeared and no specific side effects related to the azithromycin were noted. Oral azithromycin dosing 500 mg/day for 2 weeks is effective for treatment of intractable rosacea

Efecto de la gestión integral del estiércol en un sistema feedlot : modelación productiva y gases de efecto invernadero

Kazlauskas Kong, Leyli Giselle. Beca EVC-CIN.Bilotto, Franco. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.Fernandez Rosso, Catalina. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.Ferrati, Rosana. Instituto Multidisciplinario sobre Ecosistemas y Desarrollo Sustentable (UNCPBA- CIC). Buenos Aires, Argentina.Machado, Claudio F. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.136-150El stock de ganado bovino en la Argentina es de 54,5 millones de cabezas, con una participación creciente de los sistemas “feedlot”. El objetivo de este trabajo es cuantificar las emisiones de gases de efecto invernadero de un sistema “feedlot” mediante el desarrollo de un modelo dinámico productivo que permite analizar el efecto del barro sobre el consumo y la ganancia de peso vivo (GPV) en diferentes condiciones climáticas, las posibles instancias de mitigación a partir del manejo del estiércol, incluyendo su aplicación como fertilizante natural, y la incidencia de las emisiones provenientes de la producción del alimento en el cálculo de emisiones totales. Se consideró un “feedlot” base de 2500 animales con dos ciclos consecutivos. La intensidad de emisión del “feedlot” fue de 3,6 kg CO2.Eq. kg-1 producido, proveniente por el 42,7% del alimento, 30,3% de la fermentación entérica, 22,5% del estiércol y 4.5% del mantenimiento del mismo. El efecto barro en condiciones de humedad media y alta aumentó en 0,8 y 5,4% las emisiones de GEI respecto de la condición moderada cuando se realizó limpieza del corral luego de finalizado el ciclo. En condiciones de humedad media y considerando dos ciclos sin limpieza, el consumo total de alimento aumentó 12,5% y las emisiones totales un 14%. La aplicación directa o luego del apilado o del compostaje del estiércol como fertilizante natural de N ahorra un 42 y 27% respectivamente las emisiones respecto de la aplicación de urea sintética

Experimental investigation of the initial regime in fingering electrodeposition: dispersion relation and velocity measurements

Recently a fingering morphology, resembling the hydrodynamic Saffman-Taylor instability, was identified in the quasi-two-dimensional electrodeposition of copper. We present here measurements of the dispersion relation of the growing front. The instability is accompanied by gravity-driven convection rolls at the electrodes, which are examined using particle image velocimetry. While at the anode the theory presented by Chazalviel et al. describes the convection roll, the flow field at the cathode is more complicated because of the growing deposit. In particular, the analysis of the orientation of the velocity vectors reveals some lag of the development of the convection roll compared to the finger envelope.Comment: 11 pages, 15 figures, REVTEX 4; reference adde

Getting to Know the Gut Microbial Diversity of Metropolitan Buenos Aires Inhabitants

In recent years, the field of immunology has been revolutionized by the growing understanding of the fundamental role of microbiota in the immune system function. The immune system has evolved to maintain a symbiotic relationship with these microbes. The aim of our study was to know in depth the uncharacterized metagenome of the Buenos Aires (BA) city population and its metropolitan area, being the second most populated agglomeration in the southern hemisphere. For this purpose, we evaluated 30 individuals (age: 35.23 ± 8.26 years and BMI: 23.91 ± 3.4 kg/m2), from the general population of BA. The hypervariable regions V3-V4 of the bacterial 16S gene was sequenced by MiSeq-Illumina system, obtaining 47526 ± 4718 sequences/sample. The dominant phyla were Bacteroidetes, Firmicutes, Proteobacteria, Verrucomicrobia, and Actinobacteria. Additionally, we compared the microbiota of BA with other westernized populations (Santiago de Chile, Rosario-Argentina, United States-Human-microbiome-project, Bologna-Italy) and the Hadza population of hunter-gatherers. The unweighted UniFrac clustered together all westernized populations, leaving the hunter-gatherer population from Hadza out. In particular, Santiago de Chile?s population turns out to be the closest to BA?s, principally due to the presence of Verrucomicrobiales of the genus Akkermansia. These microorganisms have been proposed as a hallmark of a healthy gut. Finally, westernized populations showed more abundant metabolism related KEEG pathways than hunter-gatherers, including carbohydrate metabolism (amino sugar and nucleotide sugar metabolism), amino acid metabolism (alanine, aspartate and glutamate metabolism), lipid metabolism, biosynthesis of secondary metabolites, and sulfur metabolism. These findings contribute to promote research and comparison of the microbiome in different human populations, in order to develop more efficient therapeutic strategies for the restoration of a healthy dialogue between host and environment.Fil: Belforte, Fiorella Sabrina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernandez, Natalie. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Tonin Monzón, Francisco. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Rosso, Ayelen Daiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Quesada, Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Cimolai, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján; ArgentinaFil: Millán, Andrea Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Cerrone, Gloria Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Frechtel, Gustavo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Burcelin, Rémy. Inserm; Francia. Université Paul Sabatier; FranciaFil: Coluccio Leskow, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Penas Steinhardt, Alberto. Instituto Universidad de la Fundación "Héctor Barceló"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentin

Modelación productiva, económica y emisión de metano en sistemas de cría vacuna de Bahía Blanca y Coronel Rosales

El objetivo de este estudio de simulación fue evaluar la respuesta productiva, económica, emisión de metano y el valor marginal del agregado de alimento extra (VMA) en diferentes sistemas la cría vacuna de Bahía Blanca y Coronel Rosales. Se utilizó información regional y un modelo de simulación dinámico bioeconómico y ambiental (SIMUGAN) para evaluar cuatro planteos ganaderos basados en la incorporación tecnológica de pasturas perennes y prácticas de manejo como el tipo de destete: Tradicional (Trad), Transicional 1 (Trans1), Transicional 2 (Trans2) y Tecnificado (Tecn). El aumento en productividad se asoció positivamente con el margen bruto [MB($/ha)=-1488,6+30,2 x producción de carne kg/ha/año, R2 0,99] y con menor intensidad de emisión de metano [IMC(kgCH4 CO2 -e/kg peso vivo producido)=20,4-0,1x producción de carne, R2 0,98]. El VMA ($/KgMS/ha), en calidad de indicador sistémico de oportunidades de suplementación estratégica, fueron mayores en los planteos Trad y Trans1 que en Trans2 y Tecn. En líneas generales, los distintos planteos simulados presentaron un mayor VMA durante las estaciones de invierno y primavera por sobre la distribución anual de alimento extra. El presente análisis integral permitió identificar y cuantificar oportunidades de mejora en la productividad de estos sistemas incorporando pasturas permanentes.The aim of this study was to evaluate the productive, economic, methane emissions performance and the marginal value of additional feed (MVF) for the different cow-calf systems from Bahía Blanca and Coronel Rosales. A dynamic “whole-farm” model (SIMUGAN) and regional data was used to evaluate four cow-calf system scenarios based on changes in pasture area and management policies as the weaning date: Traditional (Trad), Transitional 1 (Trans1), Transitional 2 (Trans2) and High Technology (HTech). The increase in productivity was positively associated with gross margin GM($/ha)=-1488.6+30.2 x beef production, R2 0.99] and negatively associated with methane emission intensity [IMC(kgCH4 CO2 -e/kg live weight produced)= 20.4-0.1 x production, R2 0.98]. The MVF ($/KgMS/ha) is a systemic indicator for strategic supplementation opportunities, and Trad and Trans1 achieved higher values than Trans2 and Tecn. Overall, the scenarios showed higher VMA when during winter and spring seasons, followed by the annual feeding. This global assessment showed positive opportunities for improving system productivity based on perennial pasturesEEA BordenaveFil: Fernandez Rosso, Catalina. Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión de Investigaciones Científicas de la provincia de Buenos Aires; Argentina.Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Lauric, Miriam Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Bahía Blanca; ArgentinaFil: De Leo, Geronimo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Bahía Blanca; ArgentinaFil: Bilotto, Franco. Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión de Investigaciones Científicas de la provincia de Buenos Aires; Argentina.Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Torres Carbonell, Carlos Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Bahía Blanca; ArgentinaFil: Machado, Claudio F. Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Red Interinstitucional de Modelación Agropecuaria Buenos Aires Sur; Argentin

Investigating neuromagnetic brain responses against chromatic flickering stimuli by wavelet entropies

BACKGROUND: Photosensitive epilepsy is a type of reflexive epilepsy triggered by various visual stimuli including colourful ones. Despite the ubiquitous presence of colorful displays, brain responses against different colour combinations are not properly studied. METHODOLOGY/PRINCIPAL FINDINGS: Here, we studied the photosensitivity of the human brain against three types of chromatic flickering stimuli by recording neuromagnetic brain responses (magnetoencephalogram, MEG) from nine adult controls, an unmedicated patient, a medicated patient, and two controls age-matched with patients. Dynamical complexities of MEG signals were investigated by a family of wavelet entropies. Wavelet entropy is a newly proposed measure to characterize large scale brain responses, which quantifies the degree of order/disorder associated with a multi-frequency signal response. In particular, we found that as compared to the unmedicated patient, controls showed significantly larger wavelet entropy values. We also found that Renyi entropy is the most powerful feature for the participant classification. Finally, we also demonstrated the effect of combinational chromatic sensitivity on the underlying order/disorder in MEG signals. CONCLUSIONS/SIGNIFICANCE: Our results suggest that when perturbed by potentially epileptic-triggering stimulus, healthy human brain manages to maintain a non-deterministic, possibly nonlinear state, with high degree of disorder, but an epileptic brain represents a highly ordered state which making it prone to hyper-excitation. Further, certain colour combination was found to be more threatening than other combinations

A review of friction stir welding of aluminium matrix composites

As a solid state joining process, friction stir welding (FSW) has proven to be a promising approach for joining aluminium matrix composites (AMCs). However, challenges still remain in using FSW to join AMCs even with considerable progress having been made in recent years. This review paper provides an overview of the state of-the-art of FSW of AMC materials. Specific attention and critical assessment have been given to: (a) the macrostructure and microstructure of AMC joints, (b) the evaluation of mechanical properties of joints, and (c) the wear of FSW tools due to the presence of reinforcement materials in aluminium matrices. This review concludes with recommendations for future research directions