Football manager-s turnover: a deep analysis based on empirical findings

A football manager's job is always under great scrutiny, as the pressure of good results from the fans, the management and the media create a high turnover ratio in this position. This paper tries to measure, from a sample of 208 experiences of coaches in 54 different European clubs if certain variables such as the presence in the European Competitions ,the Tier of the team or the timing (Midseason or not) of the sacking influence the job tenure of the manager and the short-term performance effect of the team after the sacking of a manager

Classifying sleep-wake stages through recurrent neural networks using pulse oximetry signals

The regulation of the autonomic nervous system changes with the sleep stages causing variations in the physiological variables. We exploit these changes with the aim of classifying the sleep stages in awake or asleep using pulse oximeter signals. We applied a recurrent neural network to heart rate and peripheral oxygen saturation signals to classify the sleep stage every 30 seconds. The network architecture consists of two stacked layers of bidirectional gated recurrent units (GRUs) and a softmax layer to classify the output. In this paper, we used 5000 patients from the Sleep Heart Health Study dataset. 2500 patients were used to train the network, and two subsets of 1250 were used to validate and test the trained models. In the test stage, the best result obtained was 90.13% accuracy, 94.13% sensitivity, 80.26% specificity, 92.05% precision, and 84.68% negative predictive value. Further, the Cohen's Kappa coefficient was 0.74 and the average absolute error percentage to the actual sleep time was 8.9%. The performance of the proposed network is comparable with the state-of-the-art algorithms when they use much more informative signals (except those with EEG).Comment: 12 pages, 4 figures, 2 table

Molecular evolution and phylogenetics of rodent malaria parasites

<p>Abstract</p> <p>Background</p> <p>Over the last 6 decades, rodent <it>Plasmodium</it> species have become key model systems for understanding the basic biology of malaria parasites. Cell and molecular parasitology have made much progress in identifying genes underpinning interactions between malaria parasites, hosts, and vectors. However, little attention has been paid to the evolutionary genetics of parasites, which provides context for identifying potential therapeutic targets and for understanding the selective forces shaping parasites in natural populations. Additionally, understanding the relationships between species, subspecies, and strains, is necessary to maximize the utility of rodent malaria parasites as medically important infectious disease models, and for investigating the evolution of host-parasite interactions.</p> <p>Results</p> <p>Here, we collected multi-locus sequence data from 58 rodent malaria genotypes distributed throughout 13 subspecies belonging to <it>P. berghei, P. chabaudi, P. vinckei,</it> and <it>P. yoelii.</it> We employ multi-locus methods to infer the subspecies phylogeny, and use population-genetic approaches to elucidate the selective patterns shaping the evolution of these organisms. Our results reveal a time-line for the evolution of rodent <it>Plasmodium</it> and suggest that all the subspecies are independently evolving lineages (i.e. species). We show that estimates of species-level polymorphism are inflated if subspecies are not explicitly recognized, and detect purifying selection at most loci.</p> <p>Conclusions</p> <p>Our work resolves previous inconsistencies in the phylogeny of rodent malaria parasites, provides estimates of important parameters that relate to the parasite’s natural history and provides a much-needed evolutionary context for understanding diverse biological aspects from the cross-reactivity of immune responses to parasite mating patterns.</p

Application of photoluminescence and electroluminescence techniques to the characterization of intermediate band solar cells

The intermediatebandsolarcell (IBSC) is a photovoltaic device with a theoretical conversion efficiency limit of 63.2%. In recent years many attempts have been made to fabricate an intermediateband material which behaves as the theory states. One characteristic feature of an IBSC is its luminescence spectrum. In this work the temperature dependence of the photoluminescence (PL) and electroluminescence (EL) spectra of InAs/GaAs QD-IBSCs together with their reference cell have been studied. It is shown that EL measurements provide more reliable information about the behaviour of the IB material inside the IBSC structure than PL measurements. At low temperatures, the EL spectra are consistent with the quasi-Fermi level splits described by the IBSC model, whereas at room temperature they are not. This result is in agreement with previously reported analysis of the quantum efficiency of the solarcell

Intrinsic mechanisms of regulation of anti-Sm B cell anergy

One of the fundamental properties of the immune system is its capacity to avoid autoimmune diseases. The mechanisms regulating this process, known as self-tolerance, are many and varied. Self-reactive B cells that are not deleted in the bone marrow are regulated by anergy in the periphery. This mechanism renders self-reactive B cells unresponsive to activating signals. The use of immunoglobulin transgenic mouse models specific for self or neo-self antigens have indicated that anergy encompasses a broad spectrum of complex and multi-factorial states of cell unresponsiveness. The work presented here addresses the regulatory complexity of anergy in anti-Sm B cells. In this study using a high affinity anti-Sm mouse model, I have identified several mechanisms for anti-Sm B cell anergy. In addition, I have shown that the mechanisms of anergy differ depending on affinity of the B cell receptor (BCR) for Sm and subset identity. High affinity anti-Sm B cells, unlike low affinity anti-Sm B cells, are unable to survive in the presence of competitor B cells. This defect correlates with a BAFF non-responsiveness and increased cell death. Both high and low affinity anti-Sm follicular B cells express signaling competent BCRs, although BCR ligation induces rapid cell death, which correlates with an imbalance of pro and anti-apoptotic protein expression. In contrast, the BCRs expressed by marginal zone B cells from the high affinity mouse model are defective in signaling suggesting an uncoupling of the signalsome from the BCR on these cells. Activation by toll-like receptors (TLRs) is also defective in anergic B cells. I find that TLR-induced activation of anergic anti-Sm B cells is regulated by two mechanisms; activation induced cell death and a block in Plasma cell (PC) differentiation. The block in PC differentiation occurs prior to the expression of PC-specific genes. The importance of each mechanism to the regulation of B cells of different subset varies, with the block in PC differentiation not occurring efficiently until after B cells reach maturity. Together, the data presented provide evidence of the complexity and variety of anti-Sm B cells regulation and provide insight to the mechanisms of B cell anergy

Calculation of the energy spectrum of a two-electron spherical quantum dot

We study the energy spectrum of the two-electron spherical parabolic quantum dot using the exact Schroedinger, the Hartree-Fock, and the Kohn-Sham equations. The results obtained by applying the shifted-1/N method are compared with those obtained by using an accurate numerical technique, showing that the relative error is reasonably small, although the first method consistently underestimates the correct values. The approximate ground-state Hartree-Fock and local-density Kohn-Sham energies, estimated using the shifted-1/N method, are compared with accurate numerical self-consistent solutions. We make some perturbative analyses of the exact energy in terms of the confinement strength, and we propose some interpolation formulae. Similar analysis is made for both mean-field approximations and interpolation formulae are also proposed for these exchange-only ground-state cases.Comment: 18 pages, LaTeX, 2 figures-ep