470 research outputs found

    Reconstruction of the Dark Energy equation of state from latest data: the impact of theoretical priors

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    We reconstruct the Equation of State of Dark Energy (EoS) from current data using a non-parametric approach where, rather than assuming a specific time evolution of this function, we bin it in time. We treat the transition between the bins with two different methods, i.e. a smoothed step function and a Gaussian Process reconstruction, investigating whether or not the two approaches lead to compatible results. Additionally, we include in the reconstruction procedure a correlation between the values of the EoS at different times in the form of a theoretical prior that takes into account a set of viability and stability requirements that one can impose on models alternative to Λ\LambdaCDM. In such case, we necessarily specialize to broad, but specific classes of alternative models, i.e. Quintessence and Horndeski gravity. We use data coming from CMB, Supernovae and BAO surveys. We find an overall agreement between the different reconstruction methods used; with both approaches, we find a time dependence of the mean of the reconstruction, with different trends depending on the class of model studied. The constant EoS predicted by the Λ\LambdaCDM model falls anyway within the 1σ1\sigma bounds of our analysis.Comment: 17 pages, 5 figures. Prepared for submission to JCA

    Strategies to optimize glucose control during exercise in subjects with type 1 diabetes

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    Regular physical activity is highly recommended in subjects with type 1 diabetes (T1D) because of its beneficial impact on body composition, cardiovascular disease risk profile, glucose control and psychological wellbeing. However, exercise is challenging for many individuals with T1D, particularly due to the fear of hypoglycaemia, loss of glycaemic control and lack of motivation. The aim of this commentary is to briefly summarize the patterns of dysregulation of glucose homeostasis during and after exercise in subjects with T1D. In addition, we focus on carbohydrate intake and adjustment of insulin dosing as the main strategies used in clinical settings to optimize glucose control and prevent hypoglycaemia before, during and after exercise

    Relationship between Mathematical Parameters of Modified Van der Pol Oscillator Model and ECG Morphological Features

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    The mathematical model describes the electrical and mechanical activity of the cardiac conduction system thought set of differential equations. By changing the value of parameters included in these equations, it is possible to change the amplitude and the period of ECG waves. Although this model is a powerful tool for modeling the electrical activity of the heart, its use is often limited to those familiar with the differential equations that describe the system. The purpose of this work is to provide a system that allows generating an ECG signal using Ryzhii model without knowing the details of differential equations. First, we provide the relationships between the ECG wave features and the model parameters; then we generalize them through fitting neural networks. Finally, putting in series fitting neural network and heart model, we provide a system that allows generating a synthetic signal by setting as input only the morphological ECG feature. We computed numerical simulation in Simulink environment and implemented the fitting neural networks in Matlab. Results show that non-linear trends characterize the correlation functions between ECG morphological features and model parameters and that the fitting neural networks can generalized this trend by providing the model parameters given in input the respectively ECG feature

    Microtaphofacies analysis of lower Oligocene turbid-water coral assemblages

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    The presence, distribution, and preservation of coral-rich facies in the lower Oligocene Gornji Grad Beds of Slovenia are analyzed using a microtaphofacies approach. This method allows taphonomic signatures to be recognized in thin section along with the presence of coral specimens and growth forms within and between stratigraphic logs. Coral-dominated limestones within the Gornji Grad Beds are represented by rudstones in a packstone-wackestone matrix. The conditions are generally reconstructedas turbid water due to the prevalence of muddy carbonate matrix, which also leads to excellently preserved morphological features in thin section. These beds represent a reference area for the study of Paleogene corals, especially during the Oligocene, a key phase of reef development during the Cenozoic. This study also contributes to the characterization of fossil reefs in turbid-water environments. The evaluated coral fauna is dominated by delicate-branching Stylophora and Acropora, although thickly branching (Actinacis, Goniopora), phaceloid (Caulastrea), and massive forms (Alveopora, Astreopora, Antiguastrea) also occur. Assessed taphonomic signatures include fragmentation, abrasion, bioerosion, and encrustation. Three types of bioerosion traces are distinguished (Entobia, Gastrochoenolites, Trypanites). Encrustation includes both thincrusts and complex multi-taxon sequences dominated by coralline algae. Five microtaphofacies are distinguished based on variation of taphonomic signatures, taxonomic composition, and growth forms. Differences in microtaphofacies are interpreted with respect to turbidity, sediment accumulation, and water turbulence; both parautochthonous and allochthonous deposits are reconstructed. A depositional model based on the distribution of microtaphofacies in the studied sections shows a succession of coral communities with different colonization strategies reflecting generally high stress levels

    Folate-based single cell screening using surface enhanced Raman microimaging

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    Recent progress in nanotechnology and its application to biomedical settings have generated great advantages in dealing with early cancer diagnosis. The identification of the specific properties of cancer cells, such as the expression of particular plasma membrane molecular receptors, has become crucial in revealing the presence and in assessing the stage of development of the disease. Here we report a single cell screening approach based on Surface Enhanced Raman Scattering (SERS) microimaging. We fabricated a SERS-labelled nanovector based on the biofunctionalization of gold nanoparticles with folic acid. After treating the cells with the nanovector, we were able to distinguish three different cell populations from different cell lines (cancer HeLa and PC-3, and normal HaCaT lines), suitably chosen for their different expressions of folate binding proteins. The nanovector, indeed, binds much more efficiently on cancer cell lines than on normal ones, resulting in a higher SERS signal measured on cancer cells. These results pave the way for applications in single cell diagnostics and, potentially, in theranostic

    L225P mutation of ABCC8 gene: a case of transient neonatal diabetes mellitus with thrombophilic predisposition and epilepsy

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    Neonatal diabetes mellitus (NDM) is defined as a rare disorder of glucose metabolism in the first six months of life, transient (TNDM) or permanent (PNDM). TNDM usually resolves by 18 months, though it might relapse later in life; PNDM requires lifelong therapy with insulin or/and sulfonylurea. Etiology of NDM is monogenic and genetically heterogeneous. TNDM is often caused by an over-expression of paternal genes on chromosome 6 or by mutation in KCNJ11. Either way the release of insulin is reduced. PNDM is mostly associated with two genes, KCNJ11and ABCC8, which encode, respectively, Kir 6.2 and SUR1, subunits of beta cells K-ATP channel. K-ATP channel is constitutively open, hyperglycemia increases the intracellular ATP levels that cause the closure of K-ATP channel and the depolarization of beta cell causing release of insulin. Inactivating mutations in Kir 6.2 or SUR1, K-ATP channel remains open leading to impaired insulin secretion and neonatal diabetes. Here, we report a case of a three months old baby with diagnosis of NDM and thrombophilic predisposition, referred to emergency pediatric department because of intercurrent ipsilateral clonus to the upper and lower right limbs from a few days, successor seizures during the recovery and incidental finding of hyperglycemia. Child was initially treated with insulin, subsequently was started therapy with glybenclamide for 13 months with progressive decal age. The child was also successfully weaned by treatment with sulfonylureas and epilepsy was well controlled with Phenobarbital

    US foreign policy towards India: 1993-2005: a study emphasizing the importance of systematic selection and usage of documentary evidence

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    This thesis studies the implications of the selection of empirical evidence underpinning reported interpretations and conclusions about US foreign policy towards India. US-India relations have been investigated by a number of scholars whose work has been reported in well-regarded books and journal articles. Their studies typically rely for empirical evidence on official documents, and occasionally on interviews. In spite of their qualities, none of these studies provides explicit rational for their selection of US and Indian primary sources and about the procedures and the criteria used to identify relevant information from these sources. This shortcoming poses a risk for the validity of their conclusions. To assess the nature of this risk, this thesis reports a fresh study of US foreign policy towards India in which all publicly available US documents are used. These documents are the basis of a Qualitative Content Analysis (QCA), the results of which feed into the subsequent analysis. The substantive results of this research are compared with those in the existing literature. This comparison reveals, in addition to obvious similarities, important differences that can be attributed to unsystematic and incomplete use of empirical material in the existing literature. These differences, that emanate from a more explicit and systematic approach to evidence, provide grounds for a reassessment of the significance of many factors influencing US foreign policy towards India. This study identifies relevant factors that have so far been overlooked in the existing literature, and that need to be included in accounts to understand widely documented changes in this area of US foreign policy. Substantively, this thesis highlights the vital importance of the Clinton period in understanding the foreign policy of the United States, a period which had not been examined in sufficient detail by existing studies. Contrary to what most of the existing literature suggests, elements of continuity between the Clinton and the Bush administrations are particularly important to explain the evolution of US foreign policy towards India. In spite of the change in the presidency from Democrat to Republican, President George W. Bush (hereafter Bush) continued to hold the same level of commitment shown by his predecessor in developing closer strategic ties with India, making it a priority of his foreign policy. This aspect is particularly important to furthering a more thorough understanding of US relations with India

    The kinesin Eg5 inhibitor K858 induces apoptosis but also survivin-related chemoresistance in breast cancer cells

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    Inhibitors of kinesin spindle protein Eg5 are characterized by pronounced antitumor activity. Our group has recently synthesized and screened a library of 1,3,4-thiadiazoline analogues with the pharmacophoric structure of K858, an Eg5 inhibitor. We herein report the effects of K858 on four different breast cancer cell lines: MCF7 (luminal A), BT474 (luminal B), SKBR3 (HER2 like) and MDA-MB231 (basal like). We demonstrated that K858 displayed anti-proliferative activity on every analyzed breast cancer cell line by inducing apoptosis. However, at the same time, we showed that K858 up-regulated survivin, an anti-apoptotic molecule. We then performed a negative regulation of survivin expression, with the utilization of wortmannin, an AKT inhibitor, and obtained a significant increase of K858-dependent apoptosis. These data demonstrate that K858 is a potent inhibitor of replication and induces apoptosis in breast tumor cells, independently from the tumor phenotype. This anti-proliferative response of tumor cells to K858 can be limited by the contemporaneous over-expression of survivin; consequently, the reduction of survivin levels, obtained with AKT inhibitors, can sensitize tumor cells to K858-induced apoptosis

    FPGA Implementation of Hand-written Number Recognition Based on CNN

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    Convolutional Neural Networks (CNNs) are the state-of-the-art in computer vision for different purposes such as image and video classification, recommender systems and natural language processing. The connectivity pattern between CNNs neurons is inspired by the structure of the animal visual cortex. In order to allow the processing, they are realized with multiple parallel 2-dimensional FIR filters that convolve the input signal with the learned feature maps.  For this reason, a CNN implementation requires highly parallel computations that cannot be achieved using traditional general-purpose processors, which is why they benefit from a very significant speed-up when mapped and run on Field Programmable Gate Arrays (FPGAs). This is because FPGAs offer the capability to design full customizable hardware architectures, providing high flexibility and the availability of hundreds to thousands of on-chip Digital Signal Processing (DSP) blocks. This paper presents an FPGA implementation of a hand-written number recognition system based on CNN. The system has been characterized in terms of classification accuracy, area, speed, and power consumption. The neural network was implemented on a Xilinx XC7A100T FPGA, and it uses 29.69% of Slice LUTs, 4.42% of slice registers and 52.50% block RAMs. We designed the system using a 9-bit representation that allows for avoiding the use of DSP. For this reason, multipliers are implemented using LUTs. The proposed architecture can be easily scaled on different FPGA devices thank its regularity. CNN can reach a classification accuracy of 90%

    INFLUENZA DEL SOTTOSUOLO SUL COMPORTAMENTO DINAMICO DEL CAMPANILE DEL CARMINE A NAPOLI

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    La nota descrive l’identificazione dinamica del campanile del Carmine a Napoli, effettuata attraverso analisi dinamiche su un modello tridimensionale del sistema terreno - fondazione - struttura, tarato sui risultati di dettagliate indagini in situ. Sono stati riconosciuti fenomeni di risonanza tra la frequenza fondamentale del terreno e la seconda frequenza di vibrazione della struttura che ne condizionano il comportamento dinamico
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