Boundary Controllability and Observability of a Viscoelastic String

In this paper we consider an integrodifferential system, which governs the vibration of a viscoelastic one-dimensional object. We assume that we can act on the system at the boundary and we prove that it is possible to control both the position and the velocity at every point of the body and at a certain time $T$, large enough. We shall prove this result using moment theory and we shall prove that the solution of this problem leads to identify a Riesz sequence which solves controllability and observability. So, the result as presented here are constructive and can lead to simple numerical algorithms

Improvement of the Engineering Student’s Training inside University Laboratories through Quality Management Systems

This article analyzes the potentialities and the various consequences that may occur during engineering student’s educational path when they undertake a training activity,both if it is a thesis work or an internship, in a laboratory implementing a QualityManagement System (QMS). This is important because it may change the job’s organization (perspectives) and the problem solving approach, and it gives students a very important added value appreciated in workplaces. It is important to explain some relevant points in order to understand how a Quality Management System (hereafter referred to as QMS) can give a significant support to students’ training

Testosterone Replacement Therapy: Long-Term Safety and Efficacy.

Recent position statements and guidelines have raised the distinction between a true and false, age-related hypogonadism (HG) or late-onset hypogonadism (LOH). The former is the consequence of congenital or acquired “organic” damage of the brain centers or of the testis. The latter is mainly secondary to age-related comorbidities and does not require testosterone (T) therapy (TTh). In addition, concerns related to cardiovascular (CV) safety have further increased the scepticism related to TTh. In this paper, we reviewed the available evidence supporting the efficacy of TTh in non-organic HG and its long term safety. A large amount of evidence has documented that sexual symptoms are the most specific correlates of T deficiency. TTh is able to improve all aspects of sexual function independent of the pathogenetic origin of the disease supporting the scientific demonstration that LOH does exist according to an “ex-juvantibus” criterion. Although the presence of metabolic derangements could mitigate the efficacy of TTh on erectile dysfunction, the positive effect of TTh on body composition and insulin sensitivity might counterbalance the lower efficacy. CV safety concerns related to TTh are essentially based on a limited number of observational and randomized controlled trials which present important methodological flaws. When HG is properly diagnosed and TTh correctly performed no CV and prostate risk have been documented

Propagation model for the Land Mobile Satellite channel in urban environments

This paper presents the major characteristics of a simulation package capable of performing a complete narrow and wideband analysis of the mobile satellite communication channel in urban environments for any given orbital configuration. The wavelength-to-average urban geometrical dimension ratio has required the use of the Geometrical Theory of Diffraction (GTD). For the RF frequency range, the model has been designed to be (1 up to 60 GHz) extended to include effects of non-perfect conductivity and surface roughness. Taking advantage of the inherent capabilities of such a high frequency method, we are able to provide a complete description of the electromagnetic field at the mobile terminal. Using the information made available at the ray-tracer and GTD solver outputs, the Land Mobile Satellite (LMS) urban model can also give a detailed description of the communication channel in terms of power delay profiles, Doppler spectra, channel scattering functions, and so forth. Statistical data, e.g. cumulative distribution functions, level crossing rates or distributions of fades are also provided. The user can access the simulation tool through a Design-CAD user-friendly interface by means of which she can effectively design her own urban layout and run consequently all the envisaged routines. The software is optimized in its execution time so that numerous runs can be achieved in a considerably short time

Splenic Flexure Volvulus Presenting with Peritonitis: Case Report and Review of the Literature

Splenic flexure is the rarest site for colonic volvulus. We report a case of an 18 years old woman, admitted to our department for tender and sore abdomen, nausea and vomiting. A barium enema reported a splenic flexure volvulus. Explorative laparotomy revealed peritonitis originating from an extensive gangrene of splenic flexure of the colon, caused by 360° volvulus. The colon was encircled by omentum at its base. A resection with primary anastomosis was performed. Anatomic abnormalities and partial intestinal malrotation are the main pathogenetic cause

Post-operative complications after abdominal surgery in patients treated with oral anticoagulant therapy

Introduction: The management of oral anticoagulant therapy preceding abdominal surgery is a clinical problem that will be more and more frequent in the coming years. Objectives: To investigate the correlation between comorbidities (at the time of surgical treatment) and abdominal surgery post-operative complications in patients treated with OAT, in order to identify risk stratification, correct timing of surgical treatment and postoperative support requirement. Materials and Methods: In this Prospective Observational Study all patients undergoing abdominal programmed surgery between September 1st 2009 and May 31th 2011 were enrolled. Surgical outcomes and complications were recorded (transfusion requirements, anastomotic leaks, abdominal wall collections, abdominal collections, re-interventions, infections, anemia, hospital re-admission, death). Results: A total of 834 patients were therefore considered,35 inOAT (Group A) and 780 not in OAT (Group B). Seven patients in Group A and 153 patients in Group B required transfusion (20,0% vs 19,6%, p= ns), with a mean of 2.71 RBC units required in Group A and2.75 inGroup B. As for fresh frozen plasma, the mean requirement was 0.57 units in Group A as compared to 0.24 units in Group B (p= ns). Conclusions: Although bleeding in the peri-operative period was feared, hemorrhagic events were not more frequent in the OAT group as compared to the non-OAT one. On the contrary, the most serious complications, including death, were related to thrombotic episodes. A multidisciplinary evaluation is therefore fundamental for these patients, requiring the implementation of new "ad hoc" guidelines

Long-term effects of functional appliances in treated versus untreated patients with Class II malocclusion: A systematic review and meta-analysis

Objective To assess the cephalometric skeletal and soft-tissue of functional appliances in treated versus untreated Class II subjects in the long-term (primarily at the end of growth, secondarily at least 3 years after retention). Search methods Unrestricted electronic search of 24 databases and additional manual searches up to March 2018. Selection criteria Randomised and non-randomised controlled trials reporting on cephalometric skeletal and soft-tissue measurements of Class II patients (aged 16 years or under) treated with functional appliances, worn alone or in combination with multi-bracket therapy, compared to untreated Class II subjects. Data collection and analysis Mean differences (MDs) and 95% confidence intervals (95% CIs) were calculated with the random-effects model. Data were analysed at 2 primary time points (above 18 years of age, at the end of growth according to the Cervical Vertebral Maturation method) and a secondary time point (at least 3 years after retention). The risk of bias and quality of evidence were assessed according to the ROBINS tool and GRADE system, respectively. Results Eight non-randomised studies published in 12 papers were included. Functional appliances produced a significant improvement of the maxillo-mandibular relationship, at almost all time points (Wits appraisal at the end of growth, MD -3.52 mm, 95% CI -5.11 to -1.93, P < 0.0001). The greatest increase in mandibular length was recorded in patients aged 18 years and above (Co-Gn, MD 3.20 mm, 95% CI 1.32 to 5.08, P = 0.0009), although the improvement of the mandibular projection was negligible or not significant. The quality of evidence was \u2018very low\u2019 for most of the outcomes at both primary time points. Conclusions Functional appliances may be effective in correcting skeletal Class II malocclusion in the long-term, however the quality of the evidence was very low and the clinical significance was limited

Inference of population splits and mixtures from genome-wide allele frequency data

Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, we present a statistical model for inferring the patterns of population splits and mixtures in multiple populations. In this model, the sampled populations in a species are related to their common ancestor through a graph of ancestral populations. Using genome-wide allele frequency data and a Gaussian approximation to genetic drift, we infer the structure of this graph. We applied this method to a set of 55 human populations and a set of 82 dog breeds and wild canids. In both species, we show that a simple bifurcating tree does not fully describe the data; in contrast, we infer many migration events. While some of the migration events that we find have been detected previously, many have not. For example, in the human data we infer that Cambodians trace approximately 16% of their ancestry to a population ancestral to other extant East Asian populations. In the dog data, we infer that both the boxer and basenji trace a considerable fraction of their ancestry (9% and 25%, respectively) to wolves subsequent to domestication, and that East Asian toy breeds (the Shih Tzu and the Pekingese) result from admixture between modern toy breeds and "ancient" Asian breeds. Software implementing the model described here, called TreeMix, is available at http://treemix.googlecode.comComment: 28 pages, 6 figures in main text. Attached supplement is 22 pages, 15 figures. This is an updated version of the preprint available at http://precedings.nature.com/documents/6956/version/