Novel U-Shaped D-A-D π-conjugated Systems with Mechanochromic Properties: An Experimental and Theoretical Vibrational Spectroscopic Investigation

Π-conjugated compounds have been widely studied in the last few decades due to their huge field of application in organic electronics. Specifically, stimuli-responsive Π-conjugated materials which are sensitive to external stimulus (i.e., temperature, pressure, etc) have several uses like sensors, probes and security inks, for example.1 In this work, we study two U-shape Donor-Acceptor-Donor (D-A-D) systems that are found to exhibit interesting thermal- and pressure-dependent properties. 2 They consist on two different conformers of phenothiazine-dibenzo[a,j]phenazine-phenothiazine which differs from the position of the phenothiazine respect to the dibenzophenzaine central core. Compound 1R is the equatorial-equatorial conformer and 1Y is the axial-axial conformer (Figure 1). The dibenzophenzaine group acts as an electron-acceptor whereas the phenothiazine unit acts as an electron-donor. It has been reported that this U-shape D-A-D compound shows a multi-active color changing in 3 steps and their luminescence changes with temperature, pressure and acid exposition.2 In this work, we aim to elucidate how the external stimuli (i.e. temperature, pressure, acid ambient) affects the molecular structure at both intra- and intermolecular level. To this end, we use UV-Vis absorption, Raman (Figure 1) and Infrared spectroscopy experiments in combination with DFT calculations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Interference Conditions of the Reconsolidation Process in Humans: The Role of Valence and Different Memory Systems

Following the presentation of a reminder, consolidated memories become reactivated followed by a process of re-stabilization, which is referred to as reconsolidation. The most common behavioral tool used to reveal this process is interference produced by new learning shortly after memory reactivation. Memory interference is defined as a decrease in memory retrieval, the effect is generated when new information impairs an acquired memory. In general, the target memory and the interference task used are the same. Here we investigated how different memory systems and/or their valence could produce memory reconsolidation interference. We showed that a reactivated neutral declarative memory could be interfered by new learning of a different neutral declarative memory. Then, we revealed that an aversive implicit memory could be interfered by the presentation of a reminder followed by a threatening social event. Finally, we showed that the reconsolidation of a neutral declarative memory is unaffected by the acquisition of an aversive implicit memory and conversely, this memory remains intact when the neutral declarative memory is used as interference. These results suggest that the interference of memory reconsolidation is effective when two task rely on the same memory system or both evoke negative valence.Fil: Fernández, Rodrigo Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Bavassi, Mariana Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Kaczer, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Forcato, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Pedreira, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

A quantitative study of the evolution of open source software communities

Typically, virtual communities exhibit the well-known phenomenon of participation inequality, which means that only a small percentage of users is responsible of the majority of contributions. However, the sustainability of the community requires that the group of active users must be continuously nurtured with new users that gain expertise through a participation process. This paper analyzes the time evolution of Open Source Software (OSS) communities, considering users that join/abandon the community over time and several topological properties of the network when modeled as a social network. More specifically, the paper analyzes the role of those users rejoining the community and their influence in the global characteristics of the network

Examining the power-law distribution among eWOM communities: a characterisation approach of the Long Tail

Nowadays electronic word-of-mouth (eWOM) communities symbolise a significant source of information that helps customers to make informed purchasing decisions. Through eWOM communities, a great audience of users is able to acquire knowledge from reviews concerning products and services that are less popular to the majority. The Long Tail effect is a manifestation of such redistribution of demand from popular products to niche products. In this paper, a new methodology that mathematically fits the relationship between the power-law distribution and the Long Tail from an eWOM community is developed. In addition, this paper defines a tool for finding niche products inaccessible through conventional channels. The results are consistent in showing that not all the categories fitting a power-law distribution are characterised by the Long Tail phenomenon, and conversely some of those having a Long Tail do not fit a power-law distribution

Common variable immunodeficiency. Epidemiology and clinical manifestations in 69 patients.

La inmunodeficiencia común variable (IDCV) se caracteriza por una alteración en la producción de anticuerpos y una mayor susceptibilidad a infecciones por bacterias extracelulares capsuladas, principalmente del tracto respiratorio. Analizamos las características clínicas de 69 pacientes, evaluados en un período de 10 años en tres centros de la ciudad de Buenos Aires. Al inicio del estudio se encontraban en seguimiento 14 pacientes y al finalizar 60; la mayoría fueron derivados por infecciones o hipogammaglobulinemia, y casi la mitad con diagnóstico establecido de inmunodeficiencia. Sesenta y cinco (94.2%) pacientes presentaron infecciones por gérmenes capsulados, cuatro (6.1%) sepsis y dos tuberculosis. La edad promedio de comienzo de los síntomas infecciosos fue de 18.1 años, la edad promedio al momento del diagnóstico fue de 29.6 años y el retraso diagnóstico de 11.9 años. En 41 (59.4%) pacientes se registró el antecedente de diarreas recurrentes o crónicas. En 22 (31.9%) se diagnosticaron 13 enfermedades autoinmunes, siendo las más frecuentes las hematológicas y el hipotiroidismo. Ocho pacientes tuvieron linfoproliferación policlonal histológica, cuatro (5.8%) como enfermedad granulomatosa de hígado, laringe y piel, y cuatro como neumonía intersticial linfoidea (NIL). Diecinueve (27.5%) pacientes presentaron esplenomegalia y 23/57 (40.3%) imágenes sugestivas de procesos granulomatosos o linfocíticos en la TAC de tórax (incluidos los 4 con NIL). Tres (4.3%) pacientes desarrollaron linfoma B, cuatro (5.8%) adenocarcinoma de estómago y uno cáncer de mama. El estudio tuvo una mediana de seguimiento de 54 meses, rango 1-353 y durante el período del mismo murieron cuatro pacientes (5.8%).Common variable immunodeficiency (CVID) is characterized by an impaired antibody production and an increased susceptibility to recurrent infections of the respiratory tract, mainly by extracellular encapsulated bacteria. We analyzed the clinical characteristics of 69 patients evaluated over a period of 10 years at three centers in the city of Buenos Aires. At the onset of the study 14 patients were on follow up, and at its end the number of patients reached to 60. Most of them consulted for infection or hypogammaglobulinemia and nearly half had an established diagnosis of immunodeficiency. Sixty-five (94.2%) patients had infections by encapsulated bacteria, four (6.1%) sepsis and two tuberculosis. The average age of onset of infectious symptoms was 18.1 years; the average age at diagnosis was 29.6 years and the delay to diagnosis 11.9 years. Forty one (59.4%) patients reported a history of recurrent or chronic diarrhea. In 22 (31.9%) 13 autoimmune diseases were diagnosed, being the most frequent the hematological disorders and hypothyroidism. Eight patients had histological polyclonal lymphoproliferation, four (5.8%) with granulomatous disease affecting the liver, the larynx and/or the skin; and four as lymphoid interstitial pneumonitis (LIP). Nineteen (27.5%) patients had splenomegaly and 23/57 (40.3%) images suggestive of lymphocytic or granulomatous processes (including the 4 with LIP) in the chest CT. Three (4.3%) patients developed B cell lymphoma, four (5.8%) stomach adenocarcinoma and one breast cancer. The study had a median follow-up of 54 months, range 1-353 and four patients (5.8%) died during the follow up.Fil: Fernández Romero, Diego S.. Hospital Britanico. Serv. de Alergia E Inmunologia Clinica; ArgentinaFil: Juri, María C.. Hospital Britanico. Serv. de Alergia E Inmunologia Clinica; ArgentinaFil: Paolini, María V.. Hospital Durand; ArgentinaFil: Malbran, Alejandro. Hospital Britanico. Serv. de Alergia E Inmunologia Clinica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A Case-Control Study of Cognitive Function in Patients with End-Stage Renal Disease Before and After Hemodialysis in Southern Spain

BACKGROUND: This single-center study aimed to investigate the effects of repetitive transcranial magnetic stimulation (rTMS) on modulation of thyroid hormone levels and cognition in the recovery stage of patients with cognitive dysfunction following stroke. MATERIAL AND METHODS: Seventy post-stroke patients who had cognitive impairment were randomly assigned to either the rTMS group or the control (sham) group. Both groups were administered basic treatment, with the rTMS group receiving rTMS (1 Hz, 90% MT, 1000 pulse/20 min, once a day for 5 days, for a total of 20 times), the stimulation site was the contralateral dorsolateral prefrontal cortex (DLPFC), and the sham group receiving sham stimulation which had the same stimulation parameters and site, except that the coil plane was placed perpendicular to the surface of the scalp. Cognitive function assessment and thyroid function tests were performed before and after 4 weeks of treatment. RESULTS: Serum levels of triiodothyronine (T3), free triiodothyronine (FT3), and thyroid stimulating hormone (TSH) showed a positive correlation with Montreal Cognitive Assessment (MoCA) scale score of stroke patients in the recovery phase. The post-treatment change in the scores of MoCA and Modified Barthel Index (MBI) and scores of 3 cognitive domains (visuospatial function, memory, and attention), as well as serum T3, FT3, and TSH levels, were improved more significantly in the rTMS group, and T3 and FT3 levels significantly affected the MoCA scores within the reference range. CONCLUSIONS: Serum T3, FT3, and TSH levels of stroke patients in the recovery phase were positively correlated with MoCA score. rTMS increased T3, FT3, and TSH levels and also improved MoCA and MBI of patients in the recovery phase of stroke

Cycloidal Domains in the Magnetization Reversal Process of Ni80Fe20/Nd16Co84/Gd12Co88 Trilayers

The magnetization reversal of each individual layer in magnetic trilayers ( permalloy / Nd Co / Gd Co ) is investigated in detail with x-ray microscopy and micromagnetic calculations. Two sequential inversion mechanisms are identified. First, magnetic vortex-antivortex pairs move along the field direction while inverting the magnetization of magnetic stripes until they are pinned by defects. The vortex-antivortex displacements are reversible within a field interval which allows their controlled motion. Second, as the reversed magnetic field increases, cycloidal domains appear in the permalloy layer as a consequence of the dissociation of vortex-antivortex pairs due to pinning. The field range where magnetic vortices and antivortices are effectively guided by the stripe pattern is of the order of tens of mT for the Ni Fe layer, as estimated from the stability of cycloid domains in the sample

The moderating role of prior experience in technological acceptance models for ubiquitous computing services in urban environments

Ubiquitous computing services constitute a new information technology that can be used in thousands of potential applications and environments. Ubiquitous computing is also changing the classic paradigm of information technology as it is forcing social and cultural changes. Determining factors affecting the use of ubiquitous services is essential to correctly define the characteristics of new value added services. However, this study investigates not only these factors, but also the moderating effect of previous experience. Due to the technological nature of ubiquitous services, previous experience alters the way in which potential users face these services. Findings suggest that previous experience changes the way in which antecedent relates to basic TAM constructs. The derived research models and empirical results also provide valuable indicators for future research and managerial guidelines for the successful adoption of ubiquitous computing servicesJunta de Andalucia. Consejería de Economía, Innovación, Ciencia y Empleo P12-SEJ-32

Análisis de las competencias y perfiles profesional es de los programas de máster en el ámbito de las TIC

El objetivo de este trabajo es realizar un análisis comparativo de la oferta actual de programas de máster en el ámbito de las TICs ofertados en España. Como punto de partida se tomarán las competencias definidas en diversas iniciativas Europeas y los perfiles profesionales específicos al ámbito de las TICs definidos por el consorcio Career-Space. Como resultado se obtendrá el grado de cobertura en España de los perfiles profesionales demandados por la industria, identidad las principales carencias existente