Neuromodulatory effects of 17β-estradiol on synaptic transmission in the entorhinal cortex

Changes in endogenous concentrations of estrogens can influence cognition in humans and animals. Estrogens are thought to affect cognition by modulating synaptic and neuronal function. The hippocampus is important for learning and memory, and estrogens can enhance synaptic transmission in that region. The entorhinal cortex is involved in object recognition, olfaction, and navigation, and provides the hippocampus with most of its cortical sensory and associational inputs. However, the contribution of estrogens to the modulation of entorhinal cortex function is unclear. The work presented herein used electrophysiological and protein quantification techniques to assess the effects of estrogens in the entorhinal cortex. Electrically evoked postsynaptic field potential recordings (fEPSPs) were used in the first experiments to assess the rapid functional effects of acute 17-estradiol (E2) application on excitatory glutamatergic transmission in the superficial layers of the entorhinal cortex in vitro. Results demonstrated that E2 reversibly facilitates fEPSPs via activation of the membrane-bound G protein-coupled estrogen receptor-1 (GPER1). The second group of experiments further examined the cellular mechanisms of this GPER1-mediated facilitation using whole-cell patch-clamp recordings to measure changes in intracellular postsynaptic currents following E2 exposure. These recordings showed significant reductions in NMDA receptor-mediated excitatory postsynaptic currents and GABAA receptor-mediated inhibitory currents following E2 exposure. This suggests that E2 rapidly suppresses inhibition to facilitate excitatory synaptic transmission. Diminished estrogenic function following natural or surgical menopause can induce cognitive alterations which may be ameliorated by estrogen supplementation. The loss of estrogens can alter cholinergic function throughout the brain and this may contribute to cognitive alterations. The last group of experiments explored in this thesis tested the effects of prolonged estrogen loss on cholinergic function in the entorhinal cortex. Western blot protein quantification showed significant reductions in acetylcholinesterase and M1 receptor protein following ovariectomy when compared to intact rats, and E2 supplementation following ovariectomy prevented these effects. Application of eserine, an acetylcholinesterase inhibitor, markedly reduced fEPSP amplitudes in all groups, but the reduction observed in ovariectomized rats was significantly reduced compared to intact and E2 supplemented groups. Together, these works provide evidence for the modulation of synaptic function by 17-estradiol in the entorhinal cortex

Participatory research in Mesoamerica and data protection in Europe (and elsewhere)

This essay interrogates the tensions between participatory ethnographic research methods and newly emerging legal regimes of data protection and privacy. Drawing on the example of recent grant-funded research in Mexico, the essay charts how the European General Data Protection Regulation (GDPR) impedes the practices and ethos of participatory research in significant ways. In particular, new legal requirements about data collection, access and storage, and “the right to be forgotten,” effectively preclude integrating community members into research planning or data collection. As countries around the world move towards more robust and comprehensive data protection and privacy laws, the issues raised in this essay are likely to become more pressing in many different research contexts in the future

Effect of Azospirillum brasilense and mycorrhizal soil fungi on topinambur grown in a greenhouse

To determine the effect of Azospirillum brasilense and soil mycorrhizal fungi on the nutrition of the Jerusalem artichoke crop (Helianthus tuberosus L.), evaluations of agronomic parameters and the health status of the plants were carried out, under greenhouse conditions. The tests were carried out, at the moment of the implantation of the culture: the tubers were inoculated with A. brasilense and with native mycorrhizal fungi, generating four treatments including the control and the co-inoculation of the consortium of the microorganisms under study (T0: control or control without inoculation; T1: inoculation with native A. brasilense; T2: inoculation with native mycorrhizal fungi and T3: joint inoculation with A. brasilense and native mycorrhizal fungi. The results indicate that co-inoculation with A. brasilense and with native mycorrhizal fungi increased plant growth in height, leaf area, biomass, dry matter, and yields significantly in greenhouse production. It was determined that the application of the selected microorganisms has a plant growth-promoting effect, increasing the productivity of cultivated topinambur in the greenhouse.Fil: Di Barbaro, Maria Gabriela. Universidad Nacional de Catamarca; ArgentinaFil: Andrada, Horacio. Universidad Nacional de Catamarca; ArgentinaFil: Batallan Morales, Silvana Rosa. Universidad Nacional de Catamarca; ArgentinaFil: Espeche Acosta, Eliana. Universidad Nacional de Catamarca; ArgentinaFil: Rizo, Melisa. Universidad Nacional de Catamarca; ArgentinaFil: del Valle, Eleodoro Eduardo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Brandan, Celia Ines. Universidad Nacional de Tucumán; Argentin

Domain-wall structure in thin films with perpendicular anisotropy: Magnetic force microscopy and polarized neutron reflectometry study

Ferromagnetic domain patterns and three-dimensional domain-wall configurations in thin CoCrPt films with perpendicular magnetic anisotropy were studied in detail by combining magnetic force microscopy and polarized neutron reflectometry with micromagnetic simulations. With the first method, lateral dimension of domains with alternative magnetization directions normal to the surface and separated by domain walls in 20-nm-thick CoCrPt films were determined in good agreement with micromagnetic simulations. Quantitative analysis of data on reflectometry shows that domain walls consist of a Bloch wall in the center of the thin film, which is gradually transformed into a pair of Néel caps at the surfaces. The width and in-depth thickness of the Bloch wall element, transition region, and Néel caps are found consistent with micromagnetic calculations. A complex structure of domain walls serves to compromise a competition between exchange interactions, keeping spins parallel, magnetic anisotropy orienting magnetization normal to the surface, and demagnetizing fields, promoting in-plane magnetization. It is shown that the result of such competition strongly depends on the film thickness, and in the thinner CoCrPt film (10 nm thick), simple Bloch walls separate domains. Their lateral dimensions estimated from neutron scattering experiments agree with micromagnetic simulations.Microelectronics Advanced Research Corporation (MARCO)United States. Defense Advanced Research Projects Agenc

Magnetization reversal and exchange bias effects in hard/soft ferromagnetic bilayers with orthogonal anisotropies

The magnetization reversal processes are discussed for exchange-coupled ferromagnetic hard/soft bilayers made from Co[subscript 0.66]Cr[subscript 0.22]Pt[subscript 0.12] (10 and 20 nm)/Ni (from 0 to 40 nm) films with out-of-plane and in-plane magnetic easy axes respectively, based on room temperature hysteresis loops and first-order reversal curve analysis. On increasing the Ni layer thicknesses, the easy axis of the bilayer reorients from out-of-plane to in-plane. An exchange bias effect, consisting of a shift of the in-plane minor hysteresis loops along the field axis, was observed at room temperature after in-plane saturation. This effect was associated with specific ferromagnetic domain configurations experimentally determined by polarized neutron reflectivity. On the other hand, perpendicular exchange bias effect was revealed from the out-of-plane hysteresis loops and it was attributed to residual domains in the magnetically hard layer.National Science Foundation (U.S.)MIT-Spain/La Cambra de Barcelona Seed Fun

Biofertilization of topinambur with Azospirillum brasilense and native mycorrhical fungi, cultivated in the Central Valley of Catamarca, Argentina

To evaluate the effect of Azospirillum and mycorrhizal soil fungi on the nutrition of the Jerusalem artichoke crop (Helianthus tuberosus L.), determinations of agronomic parameters and the health status of the plants were carried out under field conditions. The tests were carried out, at the time of the implantation of the culture: the ?seeds? were inoculated with A. brasilense and with native mycorrhizal fungi, generating four treatments including the control and the co-inoculation of the consortium of the microorganisms under study (T0: control or uninoculated control; T1: inoculation with native A. brasilense; T2: inoculation with native mycorrhizal fungi and T3: joint inoculation with A. brasilense and native mycorrhizal fungi). The results indicate that co-inoculation with A. brasilense and native mycorrhizal fungi, significantly increased plant growth in height, leaf area, biomass, dry matter, and yields. It was determined that the application of the selected microorganisms has a promoting effect of plant growth, increasing the growth and productivity of the topinambur crop.Fil: Di Barbaro, Maria Gabriela. Universidad Nacional de Catamarca; ArgentinaFil: Andrada, Horacio Enrique. Universidad Nacional de Catamarca; ArgentinaFil: Batallan Morales, Silvana Rosa. Universidad Nacional de Catamarca; ArgentinaFil: Espeche Acosta, Eliana. Universidad Nacional de Catamarca; ArgentinaFil: Rizo, Melisa. Universidad Nacional de Catamarca; ArgentinaFil: Gonzalez Basso, Maria Valeria. Universidad Nacional de Catamarca; ArgentinaFil: del Valle, Eleodoro Eduardo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Brandan, Celia Ines. Universidad Nacional de Tucumán; Argentin

Magnetization reversal and exchange bias effects in hard/soft ferromagnetic bilayers with orthogonal anisotropies

21 p.The magnetization reversal processes are discussed for exchange-coupled ferromagnetic hard/soft bilayers made from Co0.66Cr0.22Pt0.12 (10 and 20 nm)/Ni (from 0 to 40 nm) films with out-of-plane and in-plane magnetic easy axes respectively, based on room temperature hysteresis loops and first-order reversal curve analysis. On increasing the Ni layer thicknesses, the easy axis of the bilayer reorients from out-of-plane to in-plane. An exchange bias effect, consisting of a shift of the in-plane minor hysteresis loops along the field axis, was observed at room temperature after in-plane saturation. This effect was associated with specific ferromagnetic domain configurations experimentally determined by polarized neutron reflectivity. On the other hand, perpendicular exchange bias effect was revealed from the out-of-plane hysteresis loops and it was attributed to residual domains in the magnetically hard layer.CAR and DN gratefully acknowledge the support of the National Science Foundation and the MIT-Spain/La Cambra de Barcelona Seed Fund. CR and DN thank the Ministerio de Economia y Competitividad for financial support (MAT2010-20798-C05-02)

Magnetic and transport properties in ordered arrays of permalloy antidots and thin films

The magnetotransport behaviors of two types of permalloy nanostructures, thin films and antidots, are presented and discussed. Antidots samples were prepared by sputtering a Ni(80)Fe(20) layer on top of a nanoporous alumina membrane. A counterpart continuous thin film grown on a continuous Si substrate was also prepared. The magnetoresistance (MR) was measured both as a function of the external applied magnetic field and of the angular orientation, and thus compared with the magnetization curves. The introduction of antidots is found to reduce the anisotropic MR and the angular dependence of the MR, simultaneously increasing the coercive field of the samples. The influence of the sample geometry on the perpendicular MR behavior is reported and discussed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3383039]107

Actividad biológica de extractos etanólicos de Tagetes minuta l. (asteraceae) sobre virus de importancia para la salud humana

2 p.Tagetes minuta L. (Asteraceae) es una hierba aromática ampliamente presente en Córdoba. Posee diversos usos en medicina popular: antimicrobiano, antimicótico, antiparasitario, insecticida. Sin embargo, los antecedentes relacionados a su actividad antiviral solo se enfocan en el virus Hepatitis B. Por ello, nuestro objetivo fue evaluar la actividad antiviral de extractos de esta especie sobre otros virus de importancia sanitaria en nuestro país. A partir de material vegetal seco de partes aéreas de tres poblaciones seleccionadas según su perfil químico de T. minuta, se obtuvieron extractos etanólicos (PI, P2 y P3) y aceites esenciales (AE) de cada población, los cuales se caracterizaron por su perfil químico. Así, el AE que se corresponde con P1 fue rico en E-Ocimenona (72%), el de P2 en E-Ocimenona (60%) y una mayor proporción de Ocimeno (15%) que P1 (0.9) utilizando el método de captación del Rojo Neutro, cuyos valores fueron de 83, 64 y 34µg/ml para P1, P2 y P3 respectivamente. La actividad virucida se evaluó sobre virus Herpes Simple I (HSV-I), Encefalitis de Saint Louis (SLEV), West Nile (WNV) y Poliovirus (PV). Cada virus fue pre-incubado con cada uno de los extractos a su CC80 durante 1hora a 37°C. Se realizaron diluciones seriadas (1/10) sembradas por duplicado sobre monocapas de células Vero e incubadas a 37°C, durante 3-7 días. Se incluyeron controles de células, virus y extractos (n=4). Mediante el método de reducción de unidades formadoras de placa, se estimó el porcentaje de inhibición viral (%I). La evaluación de la actividad virucida mostró que ninguno de los extractos fue capaz de inhibir al PV. P1 inhibió a los virus SLEV y WNV (85-82%I) y en un 50% HSV-I. Por su parte, P2 también tuvo buena actividad sobre SLEV (77%I) y, al igual que P1, inhibió al HSV-I en un 50%. P3 no fue activo para ninguno de los virus evaluados. Según los resultados obtenidos se destaca el extracto P1 como más activo y menos citotóxico y el P3 sin actividad con alta toxicidad. De acuerdo a la composición química del AE la presencia de E-Ocimenona en porcentajes mayores al 50% sería importante para la actividad virucida. Se destaca que si bien la composición de P1 y P2 sería similar, solo P1 produjo inhibición sobre WNV, probablemente por la presencia de una mayor proporción de E-Ocimenona como de otros compuestos minoritarios que favorecerían la actividad. Los resultados sugieren, que T. minuta tendría compuestos con baja citotoxicidad y potenciales propiedades antivirales. Esto justifica la planificación de estudios químicos y biológicos para evaluar más exhaustivamente las actividades observadas principalmente de P1 como así también la bioactividad de los compuestos mayoritarios presentes, y sus sinergismos.http://www.aam.org.ar/ram-nueva.aspFil: Martínez, Florencia. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. J. M. Vanella; Argentina.Fil: Farías, Adrian. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. J. M. Vanella; Argentina.Fil: Aguilar, Juan Javier. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. J. M. Vanella; Argentina.Fil: Contigiani, Marta Silvia. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. J. M. Vanella; Argentina.Fil: Konigheim, Brenda. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. J. M. Vanella; Argentina.Fil: Batallan, Gonzalo. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. J. M. Vanella; Argentina.Fil: Massuh, Yamile. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Genética; Argentina.Fil: Ojeda, Marta. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Genética; Argentina.Biología Celular, Microbiologí

Contribution to the understanding of tribological properties of graphite intercalation compounds with metal chloride

Intrinsic tribological properties of lamellar compounds are usually attributed to the presence of van der Waals gaps in their structure through which interlayer interactions are weak. The controlled variation of the distances and interactions between graphene layers by intercalation of electrophilic species in graphite is used in order to explore more deeply the friction reduction properties of low-dimensional compounds. Three graphite intercalation compounds with antimony pentachloride, iron trichloride and aluminium trichloride are studied. Their tribological properties are correlated to their structural parameters, and the interlayer interactions are deduced from ab initio bands structure calculations