To Be Connected, or Not to Be Connected: That is the Minimum Inefficiency Subgraph Problem

We study the problem of extracting a selective connector for a given set of query vertices $Q \subseteq V$ in a graph $G = (V,E)$. A selective connector is a subgraph of $G$ which exhibits some cohesiveness property, and contains the query vertices but does not necessarily connect them all. Relaxing the connectedness requirement allows the connector to detect multiple communities and to be tolerant to outliers. We achieve this by introducing the new measure of network inefficiency and by instantiating our search for a selective connector as the problem of finding the minimum inefficiency subgraph. We show that the minimum inefficiency subgraph problem is NP-hard, and devise efficient algorithms to approximate it. By means of several case studies in a variety of application domains (such as human brain, cancer, and food networks), we show that our minimum inefficiency subgraph produces high-quality solutions, exhibiting all the desired behaviors of a selective connector.Comment: In Proceedings of the 26th ACM conference on Information and Knowledge Management (CIKM 2017

Mechanical behaviour and phase transition mechanisms of a shape memory alloy by means of a novel analytical model

The aim of the present paper is to examine both the fatigue behaviour and the phase transition mechanisms of an equiatomic pseudo-elastic NiTi Shape Memory Alloy through cyclic tests (up to 100 loading cycles). More precisely, miniaturised dog-bone specimens are tested by using a customised testing machine and the contents of both austenite and martensite phase are experimentally measured by means of X-Ray diffraction (XRD) analyses. On the basis of such experimental results in terms of martensite content, an analytical model is here formulated to correlate the stress-strain relationship to the phase transition mechanisms. Finally, a validation of the present model by means of experimental data pertaining the stress-strain relationship is performed

Simultaneous Extraction of Density of States Width, Carrier Mobility and Injection Barriers in Organic Semiconductors

The predictive accuracy of state–of–the–art continuum models for charge transport in organic semiconductors is highly dependent on the accurate tuning of a set of parameters whose values cannot be effectively estimated either by direct measurements or by first principles. Fitting the complete set of model parameters at once to experimental data requires to set up extremely complex multi–objective optimization problems whose solution is, on the one hand, overwhelmingly computationally expensive and, on the other, it provides no guarantee of the physical soundness of the value obtained for each individual parameter. In the present study we present a step–by–step procedure that enables to determine the most relevant model parameters, namely the density of states width, the carrier mobility and the injection barrier height, by fitting experimental data from a sequence of relatively simple and inexpensive measurements to suitably devised numerical simulations. At each step of the proposed procedure only one parameter value is sought for, thus highly simplifying the numerical fitting and enhancing its robustness, reliability and accuracy. As a case study we consider a prototypical n-type organic polymer. A very satisfactory fitting of experimental measurements is obtained, and physically meaningful values for the aforementioned parameters are extracted

Injection Length in Staggered Organic Thin Film Transistors: Assessment and Implications for Device Downscaling

In staggered thin film transistors, the injection length is the fraction of the gate to contact overlap that is effectively involved in current injection. Its assessment is important to properly downscale device dimensions. In fact, in order to increase transistor operation speed, the whole device footprint should be downscaled, which means both the gate to contact overlap and the channel length, as they affect the relative weight of gate to contact parasitic capacitances and the carrier transit time along the channel respectively. Nevertheless, it is not advisable to make the gate to contact overlap smaller than the injection length, because this negatively affects contact resistances. Suitable figures of merits are introduced to quantify these aspects, and a method is proposed to extract the injection length from electrical measurements. As an example of application, transistors based on the prototypical n-type polymer poly[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene) (P(NDI2OD-T2) are analyzed. When the channel length is scaled while driving voltages are kept constant, in P(NDI2OD-T2) the injection length decreases as well, thus proving that the downscaling of the whole device footprint is feasible. The physical origins of this finding are analyzed and traced back to material properties, in order to suggest general guidelines for a successful transistor downscaling

The cosmic web of dwarf galaxies in a warm versus cold dark matter universe: mock galaxies in CDM and WDM simulations

Using cosmological simulations, we show that the cosmic web of dwarf galaxies in a warm dark matter (WDM) universe, wherein low mass halo formation is heavily suppressed, is nearly indistinguishable to that of a cold dark matter (CDM) universe whose low mass halos are not seen because galaxy formation is suppressed below some threshold mass. Low mass warm dark matter halos are suppressed nearly equally in all environments. For example, WDM voids in the galaxy distribution are neither larger nor emptier than CDM voids, once normalized to the same total galaxy number density and assuming galaxy luminosity scales with halo mass. It is thus a challenge to find hints about the dark matter particle in the cosmic web of galaxies. However, if the scatter between dwarf galaxy luminosity and halo properties is large, low mass CDM halos would sometimes host bright galaxies thereby populating voids that would be empty in WDM. Future surveys that will capture the small scale clustering in the local volume could thus help determine whether the CDM problem of the over-abundance of small halos with respect to the number density of observed dwarf galaxies has a cosmological solution or an astrophysical solution

I.S.Mu.L.T. Achilles Tendon Ruptures Guidelines

This work provides easily accessible guidelines for the diagnosis, treatment and rehabilitation of Achilles tendon ruptures. These guidelines could be considered as recommendations for good clinical practice developed through a process of systematic review of the literature and expert opinion, to improve the quality of care for the individual patient and rationalize the use of resources. This work is divided into two sessions: 1) questions about hot topics; 2) answers to the questions following Evidence Based Medicine principles. Despite the frequency of the pathology andthe high level of satisfaction achieved in treatment of Achilles tendon ruptures, a global consensus is lacking. In fact, there is not a uniform treatment and rehabilitation protocol used for Achilles tendon ruptures

Design and analysis of automated rack supported warehouses

Background: The lack of codified standards for the design of automated rack supported warehouses forced engineers to use personal experience and commonly accepted rules. Objective: This paper investigates the efficacy of applying Eurocodes’ rules for the design and analysis of automated rack supported warehouses. Structural performance, construction feasibility and economic effort are considered. Method: A typical case study building was designed following the two approaches proposed by Eurocodes: elastic and dissipative. Results: The satisfaction of the capacity design requirements, used for dissipative approach, was not always possible. Analyses showed the development of non-uniform collapse mechanisms and yielding patterns. Conclusion: Specific design rules and analysis techniques shall be developed accounting for the structural performance of automated rack supported warehouses

Quantitation of regional ejection fractions using gated tomographic imaging with Tc-99m-sestamibi

BACKGROUND: A new oro-dispersible film (ODF) formulation of sildenafil has been developed for the treatment of erectile dysfunction (ED) to overcome the drawbacks that some patients experience when taking the conventional film-coated tablet (FCT). AIM: To assess the effectiveness and safety of sildenafil ODF formulation in patients with ED who were using the conventional FCT. METHODS: From May 2017 through July 2017, 139 patients with ED were enrolled. Data from penile color-duplex ultrasound, medical history, hormonal evaluation, and patient self-administered questionnaires were collected. All patients were administered sildenafil 100-mg FCT for 4 weeks. Thereafter, they underwent a 2-week washout period and subsequently took sildenafil 75-mg ODF for 4 weeks. OUTCOMES: The International Index of Erectile Function (IIEF-15), Hospital Anxiety and Depression Scale (HADS), Patient Global Impressions of Improvement (PGI-I), and Clinician Global Impressions of Improvement (CGI-I) questionnaires were administered and severity of ED was classified as severe (IIEF-15 score ≤ 10), moderate (IIEF-15 score 11-16), or mild (IIEF-15 score = 17-25). RESULTS: All patients completed the final protocol. Differences in mean IIEF scores for erectile function, orgasmic function, sexual desire, and intercourse satisfaction were significantly in favor of sildenafil 100-mg FCT, whereas the mean score for overall satisfaction was in favor of sildenafil 75-mg ODF. A significant difference in changes in HADS score was found from washout to final follow-up (mean difference = -0.19; P < .01). For the ODF formulation, the median CGI-I score was 3.5 (interquartile range [IQR] = 2.5-4.5) and the median PGI-I score was 3.0 (IQR = 2.0-4.0). The median action time was 20.0 minutes (IQR = 15.0-30.0) and the median mouth time was 60.0 seconds (IQR = 30.0-120.0). CLINICAL IMPLICATIONS: The ODF formulation of a widely known drug, with the same safety and effectiveness of the FCT, was better appreciated by patients in overall satisfaction. STRENGTHS AND LIMITATIONS: This is the first clinical trial to assess the efficacy of a new formulation of sildenafil in patients with ED. The limitations of the study are related to the methodology used: it was not a case-control study and the patients were not drug-naïve for ED treatment. Therefore, only the "additional" side effects of the ODF formulation compared with FCT are reported. CONCLUSION: The new ODF formulation is as efficient and safe as the FCT formulation and offers a new choice of treatment to specialists for more precisely tailored therapy. Cocci A, Capece M, Cito G, et al. Effectiveness and Safety of Oro-Dispersible Sildenafil in a New Film Formulation for the Treatment of Erectile Dysfunction: Comparison Between Sildenafil 100-mg Film-Coated Tablet and 75-mg Oro-Dispersible Film. J Sex Med 2017;X:XXX-XXX

sn and ti influence on damage of bent hot dip galvanizing phases

Abstract: Hot dip galvanizing is the most used technique in the metallic protection field. The coating formation is mainly due to interdiffusion phenomena between iron and zinc atoms. In the last years, the introduction of different elements allows to obtain baths optimized by different characteristics. For example, the presence of Sn in the bath fluidifies the bath and it allows the formation of coatings characterized by an improved homogeneity of thickness. Presence of Ti, allows to obtain different colors of coatings due to different oxidation of Ti in the coatings. In this work a comparison between coatings obtained by the presence of 3%Sn and 0.5%Ti in the baths has been investigated at five different dipping time. In order to analyse the kinetics of coatings formation and the intermetallic phases, longitudinal sections of the bended specimens have been metallographically prepared and observed by means of an optical microscope (LOM). Finally, the mechanical behaviour of all coatings has been investigated using bending tests carried out on specimens