Topological defects and misfit strain in magnetic stripe domains of lateral multilayers with perpendicular magnetic anisotropy

Stripe domains are studied in perpendicular magnetic anisotropy films nanostructured with a periodic thickness modulation that induces the lateral modulation of both stripe periods and inplane magnetization. The resulting system is the 2D equivalent of a strained superlattice with properties controlled by interfacial misfit strain within the magnetic stripe structure and shape anisotropy. This allows us to observe, experimentally for the first time, the continuous structural transformation of a grain boundary in this 2D magnetic crystal in the whole angular range. The magnetization reversal process can be tailored through the effect of misfit strain due to the coupling between disclinations in the magnetic stripe pattern and domain walls in the in-plane magnetization configuration

Few-body decay and recombination in nuclear astrophysics

Three-body continuum problems are investigated for light nuclei of astrophysical relevance. We focus on three-body decays of resonances or recombination via resonances or the continuum background. The concepts of widths, decay mechanisms and dynamic evolution are discussed. We also discuss results for the triple $\alpha$ decay in connection with $2^+$ resonances and density and temperature dependence rates of recombination into light nuclei from $\alpha$-particles and neutrons.Comment: 9 pages, 8 figures. Proceedings of the 21st European Few Body Conference held in Salamanca (Spain) in August-September 201

Direct and sequential radiative three-body reaction rates at low temperatures

We investigate the low-temperature reaction rates for radiative capture processes of three particles. We compare direct and sequential capture mechanisms and rates using realistic phenomenological parametrizations of the corresponding photodissociation cross sections.Energy conservation prohibits sequential capture for energies smaller than that of the intermediate two-body structure. A finite width or a finite temperature allows this capture mechanism. We study generic effects of positions and widths of two- and three-body resonances for very low temperatures. We focus on nuclear reactions relevant for astrophysics, and we illustrate with realistic estimates for the $\alpha$-$\alpha$-$\alpha$ and $\alpha$-$\alpha$-$n$ radiative capture processes. The direct capture mechanism leads to reaction rates which for temperatures smaller than 0.1 GK can be several orders of magnitude larger than those of the NACRE compilation.Comment: To be published in European Physical Journal

Three-body structure of low-lying 18Ne states

We investigate to what extent 18Ne can be descibed as a three-body system made of an inert 16O-core and two protons. We compare to experimental data and occasionally to shell model results. We obtain three-body wave functions with the hyperspherical adiabatic expansion method. We study the spectrum of 18Ne, the structure of the different states and the predominant transition strengths. Two 0+, two 2+, and one 4+ bound states are found where they are all known experimentally. Also one 3+ close to threshold is found and several negative parity states, 1-, 3-, 0-, 2-, most of them bound with respect to the 16O excited 3- state. The structures are extracted as partial wave components, as spatial sizes of matter and charge, and as probability distributions. Electromagnetic decay rates are calculated for these states. The dominating decay mode for the bound states is E2 and occasionally also M1.Comment: 17 pages, 5 figures (version to appear in EPJA

Ferramenta de monitoramento da qualidade da água e aviso de risco de inundação

En julio de 2010, la Asamblea General de las Naciones Unidas reconoció el derecho humano al agua y al saneamiento, reafirmando que el acceso a agua potable limpia es esencial para la realización de todos los derechos humanos. Por lo tanto, controlar la calidad del agua debe ser una prioridad. En este marco, es interesante realizar un sistema sencillo, sostenible y de bajo costo, que facilite el control de los parámetros de calidad del agua. El objetivo general de este trabajo es diseñar e implementar un sistema de de monitoreo de la calidad del agua en redes de distribución a la población u otros escenarios donde sea necesaria analizar la potabilidad de la misma. Además, incorpora un sistema de alerta ante la posible inundación de los embalses en zonas bajas o de interés general. Dispone de una interfaz de comunicaciones móviles, soportado sobre la red GSM, GPRS y 3G, para el envío de señales de monitoreo y alarma.In July 2010, the United Nations General Assembly explicitly recognized the human right to water and sanitation, reaffirming that clean drinking water is essential for the realization of all the human rights. Therefore, controlling water quality should be a priority. In this context, it is interesting to make a simple, sustainable and low-cost system, in order take control over water quality parameters. This project main goal is to design and implement a water quality monitoring system on distribution networks to population or another interesting environment. It incorporates a quick alert system of flooding on low-altitude zones. It has mobile communication interface, over GSM, GPRS or 3G network, to send alarm and monitoring signals.Em julho de 2010, a Assembleia Geral das Nações Unidas reconheceu o direito humano à água e ao saneamento, reafirmando que o acesso a água potável limpa é essencial para a realização de todos os direitos humanos. Portanto, controlar a qualidade da água deve ser uma prioridade. Neste contexto, é interessante realizar um sistema simples, sustentável e de baixo custo que facilite o controle dos parâmetros de qualidade da água. O objetivo geral deste trabalho é projetar e implementar um sistema de monitoramento da qualidade da água em redes de distribuição para a população ou outros cenários onde seja necessário analisar a potabilidade da mesma. Além disso, incorpora um sistema de alerta para a possível inundação de reservatórios em áreas baixas ou áreas de interesse geral. Possui uma interface de comunicações móveis, suportada na rede GSM, GPRS e 3G, para o envio de sinais de monitoramento e alarme.

Nuclear astrophysics with radioactive ions at FAIR

R. Reifarth et al: ; 12 págs.; 9 figs.; Open Access funded by Creative Commons Atribution Licence 3.0 ; Nuclear Physics in Astrophysics VI (NPA6)The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process ow and r-process -decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will oer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.This project was supported by the HGF Young Investigators Project VH-NG-327, EMMI, H4F, HGS-HIRe, JINA, NAVI, DFG and ATHENA.Peer Reviewe

Impact of perineural invasion on the outcome of patients with synchronous colorectal liver metastases treated with neoadjuvant chemotherapy and surgery

Purpose: To analyze the prognostic value of variables of the primary tumor in patients with synchronous liver metastases in colorectal cancer (CLRMs) treated with neoadjuvant chemotherapy and surgery. Methods/patients: From a prospective database, we retrospectively identified all patients with synchronous CLRMs who were treated with neoadjuvant chemotherapy and liver resection. Using univariate and multivariate analyses, we identified the variables associated with tumor recurrence. Overall survival and disease-free survival were calculated using the Kaplan-Meier method with differences determined by the Cox multiple hazards model. Results were compared using the log-rank test. Results: Ninety-eight patients with synchronous CLRMs were identified. With a median follow-up of 39.8 months, overall survival and disease-free survival at 5 and 10 years were 53%, 41.7%, 29% and 29%, respectively. Univariate analysis identified three variables associated with tumor recurrence: location in the colon (p = 0.025), lymphovascular invasion (p = 0.011) and perineural invasion (p = 0.005). Multivariate analysis identified two variables associated with worse overall survival: perineural invasion (HR 2.36, 95% CI 1.162-4.818, p = 0.018) and performing frontline colectomy (HR 3.286, 95% CI 1.256-8.597, p = 0.015). Perineural invasion remained as the only variable associated with lower disease-free survival (HR 1.867, 95% CI 1.013-3.441, p = 0.045). Overall survival at 5 and 10 years in patients with and without perineural invasion was 68.2%, 54.4% and 29.9% and 21.3%, respectively (HR 5.920, 95% CI 2.241-15.630, p < 0.001). Conclusions: Perineural invasion in the primary tumor is the variable with most impact on survival in patients with synchronous CLRMs treated with neoadjuvant chemotherapy and surgery

Ig-Like Transcript 2 (ILT2) Blockade and Lenalidomide Restore NK Cell Function in Chronic Lymphocytic Leukemia

One of the cardinal features of chronic lymphocytic leukemia (CLL) is its association with a profound immunosuppression. NK cell function is markedly impaired in CLL patients, who show a significant dysregulation of the expression of activating and inhibitory receptors. Here, we analyzed the role of the novel inhibitory receptor Ig-like transcript 2 (ILT2, also termed LIR-1, LILRB1) in the regulation of NK cells in CLL. Our results show that ILT2 expression was significantly decreased on leukemic cells and increased on NK cells of CLL patients, particularly in those with advanced disease and with bad prognostic features, such as those carrying chromosome del(11q). The immunomodulatory drug lenalidomide may regulate the expression of ILT2 and its ligands in CLL since it significantly increased the expression of ILT2 and partially reestablished the expression of its ligands on leukemic cells. Furthermore, lenalidomide significantly increased the activation and proliferation of NK cells, which was strongly enhanced by ILT2 blockade. Combining ILT2 blockade and lenalidomide activated NK cell cytotoxicity resulting in increased elimination of leukemic cells from CLL patients. Overall, we describe herein the role of an inhibitory receptor involved in the suppression of NK cell activity in CLL, which is restored by ILT2 blockade in combination with lenalidomide, suggesting that it may be an interesting therapeutic strategy to be explored in this disease

Anti-IL-2 Treatment Impairs the Expansion of Treg Cell Population during Acute Malaria and Enhances the Th1 Cell Response at the Chronic Disease

Plasmodium chabaudi infection induces a rapid and intense splenic CD4+ T cell response that contributes to both disease pathogenesis and the control of acute parasitemia. The subsequent development of clinical immunity to disease occurs concomitantly with the persistence of low levels of chronic parasitemia. The suppressive activity of regulatory T (Treg) cells has been implicated in both development of clinical immunity and parasite persistence. To evaluate whether IL-2 is required to induce and to sustain the suppressive activity of Treg cells in malaria, we examined in detail the effects of anti-IL-2 treatment with JES6-1 monoclonal antibody (mAb) on the splenic CD4+ T cell response during acute and chronic P. chabaudi AS infection in C57BL/6 mice. JES6-1 treatment on days 0, 2 and 4 of infection partially inhibits the expansion of the CD4+CD25+Foxp3+ cell population during acute malaria. Despite the concomitant secretion of IL-2 and expression of high affinity IL-2 receptor by large CD4+ T cells, JES6-1 treatment does not impair effector CD4+ T cell activation and IFN-γ production. However, at the chronic phase of the disease, an enhancement of cellular and humoral responses occurs in JES6-1-treated mice, with increased production of TNF-α and parasite-specific IgG2a antibodies. Furthermore, JES6-1 mAb completely blocked the in vitro proliferation of CD4+ T cells from non-treated chronic mice, while it further increased the response of CD4+ T cells from JES6-1-treated chronic mice. We conclude that JES6-1 treatment impairs the expansion of Treg cell population during early P. chabaudi malaria and enhances the Th1 cell response in the late phase of the disease

Multi-task learning for subthalamic nucleus identification in deep brain stimulation

Deep brain stimulation (DBS) of Subthalamic nucleus (STN) is the most successful treatment for advanced Parkinson’s disease. Localization of the STN through Microelectrode recordings (MER) is a key step during the surgery. However, it is a complex task even for a skilled neurosurgeon. Different researchers have developed methodologies for processing and classification of MER signals to locate the STN. Previous works employ the classical paradigm of supervised classification, assuming independence between patients. The aim of this paper is to introduce a patient-dependent learning scenario, where the predictive ability for STN identification at the level of a particular patient, can be used to improve the accuracy for STN identification in other patients. Our inspiration is the multi-task learning framework, that has been receiving increasing interest within the machine learning community in the last few years. To this end, we employ the multi-task Gaussian processes framework that exhibits state of the art performance in multi-task learning problems. In our context, we assume that each patient undergoing DBS is a different task, and we refer to the method as multi-patient learning. We show that the multi-patient learning framework improves the accuracy in the identification of STN in a range from 4.1 to 7.7%, compared to the usual patient-independent setup, for two different datasets. Given that MER are non stationary and noisy signals. Traditional approaches in machine learning fail to recognize accurately the STN during DBS. By contrast in our proposed method, we properly exploit correlations between patients with similar diseases, obtaining an additional information. This information allows to improve the accuracy not only for locating STN for DBS but also for other biomedical signal classification problems