345 research outputs found
Detection of Gaussian signals via hexagonal sensor networks
This paper considers a special case of the problem of identifying a static
scalar signal, depending on the location, using a planar network of sensors in
a distributed fashion. Motivated by the application to monitoring wild-fires
spreading and pollutants dispersion, we assume the signal to be Gaussian in
space. Using a network of sensors positioned to form a regular hexagonal
tessellation, we prove that each node can estimate the parameters of the
Gaussian from local measurements. Moreover, we study the sensitivity of these
estimates to additive errors affecting the measurements. Finally, we show how a
consensus algorithm can be designed to fuse the local estimates into a shared
global estimate, effectively compensating the measurement errors.Comment: 16 pages, 4 figures. Accepted. v1-current: corrected typos, added
clarifications, updated and added references, extended intro and final
remark
The Strategic Value of Information: A Manager\u27s Guide to Profiting from Information Systems
The unprecedented volume of data captured by modern hospitality firms can be used to create economic value. This report provides a methodology to help hospitality managers identify and prioritize possible data-driven initiatives. This process starts with identifying the transaction-processing systems in the organization and inventorying the data they capture and store. After envisioning possible initiatives that employ these data, the methodology suggests a way to prioritize projects to ensure that only those offering positive returns are implemented. The methodology presented here allows managers to make such a cost-benefit assessment for any data-driven initiative
Bridgewater hedge fund: analisi dell'investimento short sui principali titoli italiani ed europei.
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Transient phrenic nerve paralysis associated with status asthmaticus
Phrenic nerve paralysis is a condition typically occurring after invasive procedures in the chest and neck. Here we describe a case of transient unilateral diaphragmatic paralysis in a child with status asthmaticus complicated by complete right lung atelectasis. Common causes of this disorder and possible implications for our case are discussed
Uniqueness of Classical and Nonclassical Solutions for Nonlinear Hyperbolic Systems
AbstractIn this paper we establish a general uniqueness theorem for nonlinear hyperbolic systems of partial differential equations in one-space dimension. First of all we introduce a new notion of admissible solutions based on prescribed sets of admissible discontinuitiesΊ and admissible speedsÏ. Our definition unifies in a single framework the various notions of entropy solutions known for hyperbolic systems of conservation laws, as well as for systems in nonconservative form. For instance, it covers the nonclassical (undercompressive) shock waves generated by a vanishing diffusion-dispersion regularization and characterized via a kinetic relation. It also covers Dal Maso, LeFloch, and Murat's definition of weak solutions of nonconservative systems. Under certain natural assumptions on the prescribed sets Ί and Ï and assuming the existence of a L1-continuous semi-group of admissible solutions, we prove that, for each Cauchy datum at t=0, there exists at most one admissible solution to the Cauchy problem depending L1-continuously upon the initial data. In particular, our result shows the uniqueness of the L1-continuous semi-group of admissible solutions. In short, this paper proves that supplementing a hyperbolic system with the âdynamicsâ of elementary discontinuities characterizes at most one L1-continuous and admissible solution
First steps to define murine amniotic fluid stem cell microenvironment
Stem cell niche refers to the microenvironment where stem cells reside in living organisms. Several elements define the niche and regulate stem cell characteristics, such as stromal support cells, gap junctions, soluble factors, extracellular matrix proteins, blood vessels and neural inputs. In the last years, different studies demonstrated the presence of cKit+ cells in human and murine amniotic fluid, which have been defined as amniotic fluid stem (AFS) cells. Firstly, we characterized the murine cKit+ cells present both in the amniotic fluid and in the amnion. Secondly, to analyze the AFS cell microenvironment, we injected murine YFP+ embryonic stem cells (ESC) into the amniotic fluid of E13.5 wild type embryos. Four days after transplantation we found that YFP+ sorted cells maintained the expression of pluripotency markers and that ESC adherent to the amnion were more similar to original ESC in respect to those isolated from the amniotic fluid. Moreover, cytokines evaluation and oxygen concentration analysis revealed in this microenvironment the presence of factors that are considered key regulators in stem cell niches. This is the first indication that AFS cells reside in a microenvironment that possess specific characteristics able to maintain stemness of resident and exogenous stem cells
Improved graft patency rates and mid-term outcome of diabetic patients undergoing total arterial myocardial revascularization
Objectives: Diabetes negatively affects the outcome of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) or coronary surgery. However, data are lacking with respect to the impact of arterial revascularization in the diabetic population. Methods: Between 1999 and 2003, 100 of 491 diabetics underwent coronary artery bypass graft surgery (CABG) with total arterial grafting (Group 1, G1); these patients were compared with 100 diabetics undergoing conventional CABG with saphenous veins (Group 2, G2), who were matched for Euroscore and other risk factors such as age, obesity, hypertension, left ventricular ejection fraction (LVEF), previous myocardial infarction and chronic obstructive pulmonary disease (COPD). Results: Both groups had a similar number of diseased coronary vessels (G1=2.6 vs G2= 2.7) and received a similar degree of myocardial revascularization (grafted vessels: G1=2.2 vs G2=2.4). Early outcome was comparable between the groups in terms of ventilatory support (G1=10.8±6 vs G2=10.4±5 hours), intensive care unit (ICU) stay (G1=24±12 vs G2=25±14 hours) and major post-operative complications such as atrial fibrillation (G1=26% vs G2=28%), peri-operative myocardial infarction (G1=1% vs G2=2%)and prolonged ventilatory support (G1=6% vs G2=5%). Hospital mortality was 2% in G1 and 3% in G2. Angiography was performed at a mean follow-up of 34 months in 65.9% and 71.1% of hospital survivors of G1 and G2 respectively: patients of G1 showed a significantly higher patency rate (G1=96% vs G2=83.6%, p=0.02). Additionally, patients of G1 showed a significantly lower incidence of recurrent myocardial ischemia (G1=7 pts. vs G2=18 pts., p=0.03), late myocardial infarction (G1=2 pts. vs G2=10 pts., p=0.03) and need for coronary reintervention (G1=1 pt. vs G2=12 pts, p=0.004). Conclusions: Total arterial grafting in diabetic patients significantly improved the benefits of coronary surgery providing at mid term a higher graft patency rate with a lower incidence of cardiac related events. (Heart International 2006; 3-4: 136-40
Decellularized diaphragmatic muscle drives a constructive angiogenic response in vivo
Skeletal muscle tissue engineering (TE) aims to efficiently repair large congenital and acquired defects. Biological acellular scaffolds are considered a good tool for TE, as decellularization allows structural preservation of tissue extracellular matrix (ECM) and conservation of its unique cytokine reservoir and the ability to support angiogenesis, cell viability, and proliferation. This represents a major advantage compared to synthetic scaffolds, which can acquire these features only after modification and show limited biocompatibility. In this work, we describe the ability of a skeletal muscle acellular scaffold to promote vascularization both ex vivo and in vivo. Specifically, chicken chorioallantoic membrane assay and protein array confirmed the presence of pro-angiogenic molecules in the decellularized tissue such as HGF, VEGF, and SDF-1\u3b1. The acellular muscle was implanted in BL6/J mice both subcutaneously and ortotopically. In the first condition, the ECM-derived scaffold appeared vascularized 7 days post-implantation. When the decellularized diaphragm was ortotopically applied, newly formed blood vessels containing CD31+, \u3b1SMA+, and vWF+ cells were visible inside the scaffold. Systemic injection of Evans Blue proved function and perfusion of the new vessels, underlying a tissue-regenerative activation. On the contrary, the implantation of a synthetic matrix made of polytetrafluoroethylene used as control was only surrounded by vWF+ cells, with no cell migration inside the scaffold and clear foreign body reaction (giant cells were visible). The molecular profile and the analysis of macrophages confirmed the tendency of the synthetic scaffold to enhance inflammation instead of regeneration. In conclusion, we identified the angiogenic potential of a skeletal muscle-derived acellular scaffold and the pro-regenerative environment activated in vivo, showing clear evidence that the decellularized diaphragm is a suitable candidate for skeletal muscle tissue engineering and regeneration
Semi-supervised cross-lingual speech emotion recognition
Speech emotion recognition (SER) on a single language has achieved remarkable
results through deep learning approaches over the last decade. However,
cross-lingual SER remains a challenge in real-world applications due to (i) a
large difference between the source and target domain distributions, (ii) the
availability of few labeled and many unlabeled utterances for the new language.
Taking into account previous aspects, we propose a Semi-Supervised Learning
(SSL) method for cross-lingual emotion recognition when a few labels from the
new language are available. Based on a Convolutional Neural Network (CNN), our
method adapts to a new language by exploiting a pseudo-labeling strategy for
the unlabeled utterances. In particular, the use of a hard and soft
pseudo-labels approach is investigated. We thoroughly evaluate the performance
of the method in a speaker-independent setup on both the source and the new
language and show its robustness across five languages belonging to different
linguistic strains
Low-protein diets in CKD: How can we achieve them? A narrative, pragmatic review
Low-protein diets (LPDs) have encountered various fortunes, and several questions remain open. No single study, including the famous Modification of Diet in Renal Disease, was conclusive and even if systematic reviews are in favour of protein restriction, at least in non-diabetic adults, im-plementation is lagging. LPDs are considered difficult, malnutrition is a threat and compliance is poor. LPDs have been reappraised in this era of reconsideration of dialysis indications and timing. The definition of a normal-adequate protein diet has shifted in the overall population from 1 to 1.2 to 0.8 g/kg/day. Veganâvegetarian diets are increasingly widespread, thus setting the ground-work for easier integration of moderate protein restriction in Chronic Kidney Disease. There are four main moderately restricted LPDs (0.6 g/kg/day). Two of them require careful planning of quantity and quality of food: a âtraditional â one, with mixed proteins that works on the quantity and quality of food and a vegan one, which integrates grains and legumes. Two further options may be seen as a way to simplify LPDs while being on the safe side for malnutrition: adding supplements of essential amino and keto acids (various doses) allows an easier shift from omniv-orous to vegan diets, while protein-free food intake allows for an increase in calories. Very-low
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