Targeting neurosteroid synthesis as a therapy for schizophrenia-related alterations induced by early psychosocial stress

Background Cogent evidence has shown that schizophrenia vulnerability is enhanced by psychosocial stress in adolescence, yet the underpinnings of this phenomenon remain elusive. One of the animal models that best capture the relationship between juvenile stress and schizophrenia is isolation rearing (IR). This manipulation, which consists in subjecting rats to social isolation from weaning through adulthood, results in neurobehavioral alterations akin to those observed in schizophrenia patients. In particular, IR-subjected rats display a marked reduction of the prepulse inhibition (PPI) of the startle reflex, which are posited to reflect imbalances in dopamine neurotransmission in the nucleus accumbens (NAcc). We recently documented that the key neurosteroidogenic enzyme 5α-reductase (5αR) plays an important role in the dopaminergic regulation of PPI; given that IR leads to a marked down-regulation of this enzyme in the NAcc, the present study was designed to further elucidate the functional role of 5αR in the regulation of PPI of IR-subjected rats. Methods We studied the impact of the prototypical 5αR inhibitor finasteride (FIN) on the PPI deficits and NAcc steroid profile of IR-subjected male rats, in comparison with socially reared (SR) controls. Results FIN (25–100 mg/kg, i.p.) dose-dependently countered IR-induced PPI reduction, without affecting gating integrity in SR rats. The NAcc and striatum of IR-subjected rats displayed several changes in neuroactive steroid profile, including a reduction in pregnenolone in both SR and IR-subjected groups, as well as a decrease in allopregnanolone content in the latter group; both effects were significantly opposed by FIN. Conclusions These results show that 5αR inhibition counters the PPI deficits induced by IR, possibly through limbic changes in pregnenolone and/or allopregnanolone concentrations

Noncommutative QED and the Lifetimes of Ortho and Para Positronium

We examine the implications of including corrections associated with the noncommutative extension of quantum electrodynamics - NCQED - to the decays of the ortho and para positronium (\Trip and \Sing) ground states. In NCQED, the well known charge conjugation argument restricting \Trip decays to an odd number of photons and \Sing decays to an even number of photons no longer obtains. Instead, the dominant two photon decay mode of \Sing is accompanied by a three photon mode. The dominant three photon decay mode of \Trip receives a NCQED correction, but there is no corresponding two photon decay mode in the weak binding limit. These corrections to the $P_s$ three photon decay mode have a different energy distribution, but their effect is too small to explain any discrepancy between the observed and calculated values of the \Trip lifetime.Comment: Additional reference

High energy photon-neutrino elastic scattering

The one-loop helicity amplitudes for the elastic scattering process $\gamma\nu\to\gamma\nu$ in the Standard Model are computed at high center of mass energies. A general decomposition of the amplitudes is utilized to investigate the validity of some of the key features of our results. In the center of mass, where $\sqrt{s} = 2\omega$, the cross section grows roughly as $\omega^6$ to near the threshold for $W$-boson production, $\sqrt{s} = m_W$. Although suppressed at low energies, we find that the elastic cross section exceeds the cross section for $\gamma\nu\to\gamma\gamma\nu$ when $\sqrt{s}>13$ GeV. We demonstrate that the scattered photons are circularly polarized and the net value of the polarization is non-zero. Astrophysical implications of high energy photon-neutrino scattering are discussed.Comment: 9 pages, 7 figures, RevTeX

Noncommutative QCD corrections to the gluonic decays of heavy quarkonia

We compute the Noncommutative QCD (NCQCD) contributions to the three gluon decay modes of heavy quarkonia. For triplet quarkonia (ortho-quarkonia), the NCQCD correction to the QCD three gluon decay mode, like the standard model contribution, is infrared finite. In the case of singlet quarkonia (para-quarkonia), whose QCD three gluon decay mode has infrared singularities which are removed using one-loop corrections to the two gluon mode, we find that NCQCD contribution is also infrared finite. The calculations are performed in the weak binding limit and do not require the introduction of additional effective couplings.Comment: Version accepted for publicatio

La hora del museo: la sala Uriburu del Museo Histórico y Colonial de la Provincia de Buenos Aires (Luján, 1932)

El artículo analiza el proceso de creación de la Sala Uriburu del Museo Histórico y Colonial de la Provincia de Buenos Aires instalado en la ciudad de Luján y abierto al público en 1923. La sala fue inaugurada el 4 de septiembre de 1932 y estaba destinada a honrar la memoria del líder de la "Revolución" del 6 de septiembre de 1930. El objetivo es dar cuenta de los múltiples factores que incidieron en su instalación considerando que ella no puede explicarse solamente a través de la relación directa entre coyuntura política, atmósfera nacionalista y la necesidad de crear un mito para perpetuar su memoria. Proponemos entonces explorar las prácticas y dispositivos colectivos indispensables en el proceso de creación de evidencias materiales para sustentar la visualización de un relato histórico.O artigo analisa o processo de instalação da Sala Uriburu, do Museu Histórico e Colonial da Província de Buenos Aires, fundado na cidade de Luján e aberto ao público em 1923. A sala foi inaugurada em 4 de setembro de 1932, e destinava-se a "honrar a memória" do líder da "Revolução" de 6 de setembro de 1930, poucos meses depois de sua morte. O objetivo é dar conta dos múltiplos fatores que incidiram na instalação, considerando que ela não pode ser explicada somente através da relação direta entre conjuntura política, atmosfera nacionalista e a necessidade de criar um mito para perpetuar sua memória. Propomos, então, explorar as práticas e dispositivos coletivos indispensáveis no processo de criação de evidências materiais para sustentar a visualização de um relato histórico.This article analyzes the installation of Uriburu's Hall at the Museo Histórico y Colonial de la Provincia de Buenos Aires, institution established in Luján in 1923. This hall was opened to the public in September 1932, to celebrate the name and memory of the hero of the Revolution of 1930. Far from proposing a direct relationship between politics and museum displays, this article wants to display the several elements that colluded in the creation of this hall

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of $\sqrt s =1.96$ TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is $A_{\mathrm{FB}}^{t\bar{t}} = 0.128 \pm 0.025$. The combined inclusive and differential asymmetries are consistent with recent standard model predictions

La regulación de los servicios públicos y el caso de la electricidad

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La regulación de los servicios públicos y el caso de la electricidad

La reforma del estado y los servicios públicos. A partir del año 1989 se inicia en la Argentina una profunda reforma del Estado, que reconoce en lo inmediato una situación de virtual colapso económico, atento la experiencia de las hiperinflaciones sucesivas, el peso considerable de la deuda externa y la persistente caída en las tasas de crecimiento, y en lo mediato las experiencias de la “revolución conservadora” operada tanto en Gran Bretaña como en los Estados Unidos

La regulación de los servicios públicos y el caso de la electricidad

La reforma del estado y los servicios públicos. A partir del año 1989 se inicia en la Argentina una profunda reforma del Estado, que reconoce en lo inmediato una situación de virtual colapso económico, atento la experiencia de las hiperinflaciones sucesivas, el peso considerable de la deuda externa y la persistente caída en las tasas de crecimiento, y en lo mediato las experiencias de la “revolución conservadora” operada tanto en Gran Bretaña como en los Estados Unidos