On the Firing Rate Dependency of the Phase Response Curve of Rat Purkinje Neurons In Vitro

Synchronous spiking during cerebellar tasks has been observed across Purkinje cells: however, little is known about the intrinsic cellular mechanisms responsible for its initiation, cessation and stability. The Phase Response Curve (PRC), a simple input-output characterization of single cells, can provide insights into individual and collective properties of neurons and networks, by quantifying the impact of an infinitesimal depolarizing current pulse on the time of occurrence of subsequent action potentials, while a neuron is firing tonically. Recently, the PRC theory applied to cerebellar Purkinje cells revealed that these behave as phase-independent integrators at low firing rates, and switch to a phase-dependent mode at high rates. Given the implications for computation and information processing in the cerebellum and the possible role of synchrony in the communication with its post-synaptic targets, we further explored the firing rate dependency of the PRC in Purkinje cells. We isolated key factors for the experimental estimation of the PRC and developed a closed-loop approach to reliably compute the PRC across diverse firing rates in the same cell. Our results show unambiguously that the PRC of individual Purkinje cells is firing rate dependent and that it smoothly transitions from phase independent integrator to a phase dependent mode. Using computational models we show that neither channel noise nor a realistic cell morphology are responsible for the rate dependent shift in the phase response curve

Indicações de gestão para um laboratório, a partir do cadastro de clientes e de serviços: estudo de caso da clínica fitossanitária Embrapa Clima Temperado.

bitstream/item/31621/1/comunicado91.pd

Mothers' food choices and consumption of ultra-processed foods in the Brazilian Amazon: A grounded theory study

In recent decades, an increase in consumption of ultra-processed foods (UPF), a type of product frequently associated with diet-related obesity, chronic diseases, decrease of eating traditions and loss of culinary diversity, has been observed in middle-income countries. However, there is lack of information on factors related to choosing UPF. In this study, we aimed to understand the factors promoting UPF choices and consumption among mothers living in an urban context in the Brazilian Amazon, and to present a conceptual model grounded on their experiences that illustrates the dynamics between the observed factors. For this qualitative study, we used a constructive grounded theory approach, with a theoretical sampling of 40 women, to choose mothers with high and low consumption of ultra-processed foods. Data production and the first steps of analysis were performed concomitantly, followed by four steps of coding focused on creating conceptual categories and explaining the interactions between them. Our findings highlighted the importance of context in promoting UPF choice and consumption, particularly the “food environment”, physical and virtual, and the “sociocultural environment”. These contextual aspects interacted with the two main personal aspects influencing participants' UPF consumption, one concerning practices, “cooking behaviors”, and the other concerning preferences, “food tastes”. Factors such as economic and time constraints were also important and competed to shape eating practices through interactions with participants’ health valorization. Findings are discussed in relation to food choice theories, social roles and the food environment. Implications for public health initiatives include the importance of considering environmental changes, sociocultural and economic influences, the reliance on UPF, and the role of women in the home, when promoting healthy diets

Resistência intra-específica de eucaliptos a formigas-cortadeiras.

Objetivando selecionar procedências de eucalipto resistentes às formigas-cortadeiras Atta sexdens e A. laevigata, foram instalados testes, de preferência, em amostras foliares com essas formigas. O experimento foi realizado nos laboratórios da Universidade Federal de Viçosa, utilizando-se sauveiros artificiais, de cada espécie de formiga, e material vegetal, oriundo de testes de introdução de espécies de eucaliptos, realizados pelo PRODEPEF na região de Viçosa. Os resultados indicaram que ambas as espécies de formiga são capazes de distinguir as procedências de uma mesma espécie de eucalipto. Destacaram-se, como resistentes, as seguintes procedências: E. grandis, 10695 de Kenilworth S.F., E. pilularis 9491, de Frazer Island, E. tereticornis 10051 de Atherton District e E. maculata 6169 de W. Southport, todas de Queensland, Austrália. A resistência intraespecífica não se mostrou relacionada com a latitude pois houve grandes variações entre procedências de origem geográfica praticamente idêntica. Os resultados foram semelhantes para ambas espécies de formiga, sugerindo que o fator de resistência nestas procedências é comum para as duas espécies de formiga estudadas

Dibucaine in Ionic-Gradient Liposomes: Biophysical, Toxicological, and Activity Characterization

Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of dibucaine.Fil: Couto, Verônica M.. Universidade Estadual de Campinas; BrasilFil: Prieto, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Igartúa, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Feas, Daniela Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Ribeiro, Lígia N.M.. Universidade Estadual de Campinas; BrasilFil: Silva, Camila M.G.. Universidade Estadual de Campinas; BrasilFil: Castro, Simone R.. Universidade Estadual de Campinas; BrasilFil: Guilherme, Viviane A.. Universidade Estadual de Campinas; BrasilFil: Dantzger, Darlene D.. Universidade Estadual de Campinas; BrasilFil: Machado, Daisy. Universidade Estadual de Campinas; BrasilFil: Alonso, Silvia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: de Paula, Eneida. Universidade Estadual de Campinas; Brasi

Hematología del Galgo Español utilizando el analizador hematológico LaserCyte (IDEXX)

Los Greyhounds tienen valores hematológicos y bioquímicos diferentes a los de perros de otras razas, incluyendo alto hematocrito (HCT), recuento de eritrocitos, concentración de hemoglobina (HGB), aumento de la viscosidad sanguínea y bajo recuento de leucocitos y plaquetas. Estas diferencias se han atribuido a la propia idiosincrasia de la raza, ya que están presentes en individuos normales. El objetivo del estudio era determinar si esta diferencia en los valores hematológicos se presenta en el Galgo español para poder establecer un rango de referencia para esta raza. Evaluamos hemogramas de 35 Galgos Españoles normales utilizando un dispositivo diagnóstico (LaserCyte, IDEXX). El HCT, recuento de eritrocitos, y HGB tendían a ser más altas y el recuento de plaquetas más bajo que los valores de referencia del dispositivo