On twin peak quasi-periodic oscillations resulting from the interaction between discoseismic modes and turbulence in accretion discs around black holes

Versión preprintGiven the peculiar and (in spite of many efforts) unexplained quasi-periodic oscillation (QPO) twin peak phenomena in accretion disc psd observations, the present exploratory analytical article tries to inquire deeper into the relationship between discoseismic modes and the underlying driving turbulence in order to assess its importance. We employ a toy model in the form of a Gaussian white noise driven damped harmonic oscillator with stochastic frequency. This oscillator represents the discoseismic mode. (Stochastic damping was also considered, but interestingly found to be less relevant for the case at hand.) In the context of this model, we find that turbulence interacts with disc oscillations in interesting ways. In particular, the stochastic part in the oscillator frequency behaves as a separate driving agent. This gives rise to 3:2 twin peaks for some values of the physical parameters, which we find. We conclude with the suggestion that the study of turbulence be brought to the forefront of disc oscillation dynamics, as opposed to being a mere background feature. This change of perspective carries immediate observable consequences, such as considerably shifting the values of the (discoseismic) oscillator frequencies.Universidad de Costa Rica/[805-B6-148]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic

Stimuli-responsive selection of target DNA sequences by synthetic bZIP peptides

One of the strategies used by nature to regulate gene expression relies on the stimuli controlled combination of DNA-binding proteins. This in turn determines the target-binding site within the genome, and thereby whether a particular gene is activated or repressed. Here we demonstrate how a designed basic region leucine zipper-based peptide can be directed towards two different DNA sequences depending on its dimerization arrangement. While themonomeric peptide is non-functional, a C-terminal metallo-dimer recognizes the natural ATF/CREB-binding site (5'-ATGA cg TCAT-3'), and a N-terminal disulphide dimer binds preferentially to the swapped sequence (5-TCATcg ATGA-30'). As the dimerization mode can be efficiently controlled by appropriate external reagents, it is possible to reversibly drive the peptide to either DNA site in response to such specific inputs. This represents the firstexample of a designed molecule that can bind to more than one specific DNA sequence depending on changes in its environment.Fil: Mosquera, Jesus. Universidad de Santiago de Compostela. Facultad de Quimica. Departamento de Quimica Organica; EspañaFil: Jimenez Balsa, Adrian. Universidad de Santiago de Compostela. Facultad de Quimica. Departamento de Quimica Organica; EspañaFil: Dodero, Veronica Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad de Santiago de Compostela; EspañaFil: Vázquez, M. Eugenio . Universidad de Santiago de Compostela. Facultad de Quimica. Departamento de Quimica Organica; EspañaFil: Mascareñas, José L. . Universidad de Santiago de Compostela. Facultad de Quimica. Departamento de Quimica Organica; Españ

The Winckelmann300 Project: Dissemination of Culture with Virtual Reality at the Capitoline Museum in Rome

The best way to disseminate culture is, nowadays, the creation of scenarios with virtual and augmented reality that supply the visitors of museums with a powerful, interactive tool that allows to learn sometimes difficult concepts in an easy, entertaining way. 3D models derived from reality-based techniques are nowadays used to preserve, document and restore historical artefacts. These digital contents are also powerful instrument to interactively communicate their significance to non-specialist, making easier to understand concepts sometimes complicated or not clear. Virtual and Augmented Reality are surely a valid tool to interact with 3D models and a fundamental help in making culture more accessible to the wide public. These technologies can help the museum curators to adapt the cultural proposal and the information about the artefacts based on the different type of visitor’s categories. These technologies allow visitors to travel through space and time and have a great educative function permitting to explain in an easy and attractive way information and concepts that could prove to be complicated. The aim of this paper is to create a virtual scenario and an augmented reality app to recreate specific spaces in the Capitoline Museum in Rome as they were during Winckelmann’s time, placing specific statues in their original position in the 18th century

The effect of air pollution on children’s health: a comparative study between La Plata and Bahía Blanca, Buenos Aires Province, Argentina

We present the results of a study of outdoor air quality in two comparable regions of Buenos Aires province (Argentina), La Plata and Bahía Blanca, developed jointly by researchers of National University in both cities, and of the Hospital of Bahía Blanca, between 2009 and 2011. Both regions are characterized by a large petrochemical complex and a village with outstanding traffic. In this study, we measure levels of volatile organic compounds (VOCs), particulate matter suspended in air (PM) in air outdoor and affectation of respiratory system in children between 6 and 12 years. Also, analysis of the effect of the air pollution exposure was done thought the calculation of potentially increased life time cancer risk (LCR) in children. In both regions, including three areas: urban, industrial and residential (reference area), 20 VOCs were sampled by passive monitoring (3M 3500), and determined by GC/FID, comprising n-alkanes, cycloalkanes, aromatics, chlorinated compounds, terpenoids and ketones; particulate matter (PM10) was token using a low flow sampler MiniVol TAS, and spirometry were performed, using a portable spirometer. The collected data show higher levels of PM10 in Bahía Blanca, both in the industrial zone and urban areas, industrial area of Bahía Blanca with very bad air quality, associable with a 5% increased in mortality. The levels of total VOCs found in the residential area for both regions are comparable. Spirometry parameters of children living in industrial area evidence respiratory disease respect to urban and residential areas.Fil: Colman Lerner, Jorge Esteban. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morales, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Aguilar, M.. Universidad Nacional de La Plata. Fundación Ciencias Exactas; ArgentinaFil: Giuliani, Daniela Silvana. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Orte, Marcos Agustín. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ditondo, J.. Hospital Interzonal General de Agudos “Dr. José Penna”; ArgentinaFil: Dodero, Veronica Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Massolo, L.. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Sanchez, Erica Yanina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Matamoros, N.. Universidad Nacional de La Plata. Facultad de Ingenieria; ArgentinaFil: Porta, A.. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin

Pretransplantation 18F-Fluorodeoxyglucose positron emission tomography scan predicts outcome in patients with recurrent Hodgkin lymphoma or aggressive non-hodgkin lymphoma undergoing reduced-intensity conditioning follone by allogeneic stem cell transplantation

Background: The use of positron emission tomography (PET) scanning in Hodgkin lymphoma (HL) and aggressive non-Hodgkin lymphoma (HG-NHL) has recognized prognostic value in patients who are receiving chemotherapy or undergoing autologous stem cell transplantation (SCT). In contrast, the role of PET before reduced-intensity conditioning (RIC) and followed by allogeneic SCT has not been investigated to date. Methods: PET was used to assess 80 patients who had chemosensitive disease (34 patients with HG-NHL and 46 patients with HL) before they underwent allogeneic SCT: 42 patients had negative PET studies, and 38 patients had positive PET studies. Patients underwent allograft from matched related siblings (n = 41) or alternative donors (n = 39). Results: At the time of the last follow-up, 48 patients were alive (60%), and 32 had died. The 3-year cumulative incidence of nonrecurrence mortality and disease recurrence was 17% and 40%, respectively. The cumulative incidence of disease recurrence was significantly lower in the PET-negative patients (25% vs 56%; P =.007), but there was no significant difference between the patients with or without chronic graft-versus-host disease (P =.400). The patients who had negative PET studies before undergoing allogenic SCT also had significantly better outcomes in terms of 3-year overall survival (76% vs 33%; P =.001) and 3-year progression-free survival (73% vs 31%; P =.001). On multivariate analysis, overall survival was influenced by PET status (hazard ratio [HR], 3.35), performance status (HR, 5.15), and type of donor (HR, 6.26 for haploidentical vs sibling; HR, 1.94 for matched unrelated donor vs sibling). Conclusions: The current results indicated that PET scanning appears to be an accurate tool for assessing prognosis in patients who are eligible for RIC allografting

Dysfunctional dopaminergic neurotransmission in asocial BTBR mice

Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by pronounced social and communication deficits and stereotyped behaviours. Recent psychosocial and neuroimaging studies have highlighted reward-processing deficits and reduced dopamine (DA) mesolimbic circuit reactivity in ASD patients. However, the neurobiological and molecular determinants of these deficits remain undetermined. Mouse models recapitulating ASD-like phenotypes could help generate hypotheses about the origin and neurophysiological underpinnings of clinically relevant traits. Here we used functional magnetic resonance imaging (fMRI), behavioural and molecular readouts to probe dopamine neurotransmission responsivity in BTBR T+ Itpr3tf/J mice (BTBR), an inbred mouse line widely used to model ASD-like symptoms owing to its robust social and communication deficits, and high level of repetitive stereotyped behaviours. C57BL/6J (B6) mice were used as normosocial reference comparators. DA reuptake inhibition with GBR 12909 produced significant striatal DA release in both strains, but failed to elicit fMRI activation in widespread forebrain areas of BTBR mice, including mesolimbic reward and striatal terminals. In addition, BTBR mice exhibited no appreciable motor responses to GBR 12909. DA D1 receptor-dependent behavioural and signalling responses were found to be unaltered in BTBR mice, whereas dramatic reductions in pre- and postsynaptic DA D2 and adenosine A2A receptor function was observed in these animals. Overall these results document profoundly compromised DA D2-mediated neurotransmission in BTBR mice, a finding that is likely to have a role in the distinctive social and behavioural deficits exhibited by these mice. Our results call for a deeper investigation of the role of dopaminergic dysfunction in mouse lines exhibiting ASD-like phenotypes, and possibly in ASD patient populations

Characterization of visual object representations in rat primary visual cortex

For most animal species, quick and reliable identification of visual objects is critical for survival. This applies also to rodents, which, in recent years, have become increasingly popular models of visual functions. For this reason in this work we analyzed how various properties of visual objects are represented in rat primary visual cortex (V1). The analysis has been carried out through supervised (classification) and unsupervised (clustering) learning methods. We assessed quantitatively the discrimination capabilities of V1 neurons by demonstrating how photometric properties (luminosity and object position in the scene) can be derived directly from the neuronal responses

Neuroimaging Evidence of Major Morpho-Anatomical and Functional Abnormalities in the BTBR T+TF/J Mouse Model of Autism

BTBR T+tf/J (BTBR) mice display prominent behavioural deficits analogous to the defining symptoms of autism, a feature that has prompted a widespread use of the model in preclinical autism research. Because neuro-behavioural traits are described with respect to reference populations, multiple investigators have examined and described the behaviour of BTBR mice against that exhibited by C57BL/6J (B6), a mouse line characterised by high sociability and low self-grooming. In an attempt to probe the translational relevance of this comparison for autism research, we used Magnetic Resonance Imaging (MRI) to map in both strain multiple morpho-anatomical and functional neuroimaging readouts that have been extensively used in patient populations. Diffusion tensor tractography confirmed previous reports of callosal agenesis and lack of hippocampal commissure in BTBR mice, and revealed a concomitant rostro-caudal reorganisation of major cortical white matter bundles. Intact inter-hemispheric tracts were found in the anterior commissure, ventro-medial thalamus, and in a strain-specific white matter formation located above the third ventricle. BTBR also exhibited decreased fronto-cortical, occipital and thalamic gray matter volume and widespread reductions in cortical thickness with respect to control B6 mice. Foci of increased gray matter volume and thickness were observed in the medial prefrontal and insular cortex. Mapping of resting-state brain activity using cerebral blood volume weighted fMRI revealed reduced cortico-thalamic function together with foci of increased activity in the hypothalamus and dorsal hippocampus of BTBR mice. Collectively, our results show pronounced functional and structural abnormalities in the brain of BTBR mice with respect to control B6 mice. The large and widespread white and gray matter abnormalities observed do not appear to be representative of the neuroanatomical alterations typically observed in autistic patients. The presence of reduced fronto-cortical metabolism is of potential translational relevance, as this feature recapitulates previously-reported clinical observations