Optimal configuration of active and backup servers for augmented reality cooperative games

Interactive applications as online games and mobile devices have become more and more popular in recent years. From their combination, new and interesting cooperative services could be generated. For instance, gamers endowed with Augmented Reality (AR) visors connected as wireless nodes in an ad-hoc network, can interact with each other while immersed in the game. To enable this vision, we discuss here a hybrid architecture enabling game play in ad-hoc mode instead of the traditional client-server setting. In our architecture, one of the player nodes also acts as the server of the game, whereas other backup server nodes are ready to become active servers in case of disconnection of the network i.e. due to low energy level of the currently active server. This allows to have a longer gaming session before incurring in disconnections or energy exhaustion. In this context, the server election strategy with the aim of maximizing network lifetime is not so straightforward. To this end, we have hence analyzed this issue through a Mixed Integer Linear Programming (MILP) model and both numerical and simulation-based analysis shows that the backup servers solution fulfills its design objective

The Relationship between Catalyst Precursors and Chain End Groups in Homogeneous Propene Polymerization Catalysis

The chain transfer to monomer reactions promoted by primary and secondary growing chains in the propene polymerization promoted by ansa-zirconocenes and postmetallocene precursors are studied by using DFT methods. From the theoretical results it comes out that the prevalence of propene insertion over b-hydrogen transfer to the monomer decreases drastically in the presence of a secondary chain. Furthermore, we explained the reason why C2-symmetric metallocene catalysts promote the selective formation of cis but-2-enyls end group after a 2,1 inserted unit whereas for octahedral bis(phenoxy- imine)titanium-based catalysts, chain release promotes exclusively the formation of allyl terminated chain end. These results might be useful to design ligand precursors able to obtain not only high Mn PP polymers but also tuned chain end groups to build new polymer architectures. Overall, a more general picture of the enantioselectivity of the chain transfer to monomer processes is reported

Primary Coronary Embolism as an Unusual Manifestation of Nonbacterial Thrombotic Endocarditis in a Patient with Gastric Cancer

Nonbacterial thrombotic endocarditis (NBTE) is a rare clinical condition characterized by the presence of sterile vegetations on valvular leaflets Gross and Friedberg (1936). The most frequent cause of NBTE is antiphospholipid syndrome Hughson and et al. (1993); malignancy, through an intrinsic condition of hypercoagulability, is the second most common cause Thomas (2001). Systemic thromboembolic complications are frequently associated with this condition, but coronary embolism is not common. We report the case of a patient with NBTE secondary to gastric adenocarcinoma with clinical symptoms of coronary and systemic emboli

Influence of Wind Turbines on Farmlands’ Value: Exploring the Behaviour of a Rural Community through the Decision Tree

The relationship between wind energy and rural areas leads to the controversial debate on the effects declared by rural communities after wind farms or single turbines are operative. The literature on this topic lacks dedicated studies analysing how the behaviour of rural communities towards wind turbines can affect the market value of farmlands. This research aims to examine to the extent to which the easement of wind turbines can influence the market value of farmlands in terms of willingness to pay (WTP) by a small rural community, and to identify the main factors affecting the WTP. Starting from data collected via face-to-face interviews, a decision tree is then applied to investigate the WTP for seven types of farmland in a rural town of Puglia Region (Southern Italy) hosting a wind farm. Results of the interviews show a broad acceptance of the wind farm, while the decision tree classification shows a significant reduction of WTP for all farmlands. The main factors influencing the WTP are the education level, the possibility to increase the income, the concerns for impacts on human health and for maintenance workmen. National and local policy measures have to be put in place to inform rural communities about the ‘magnitude’ of the effects they identified as crucial, so that policy-makers and private bodies will contribute to make the farmland market more equitable

Polymorphism and structural disorder in melt-crystallized and fiber samples of syndiotactic copolymers of propane with 1-butene

The structural characterization of melt-crystallized samples and oriented fibers of syndiotactic copolymers between propene and 1-butene is reported. Melt-crystallized samples of copolymers are crystallized in the form I of syndiotactic polypropylene (s-PP) up to a Content of 1-butene of 60-70 mol %, although disorder in the alternation of right- and left-handed helical chains along both axes of the unit cell is present. More ordered modifications, close to the limit ordered, fully antichiral, form I of s-PP are obtained by crystallization at high temperatures only for samples containing small contents of 1-butene (1-2 mol %). The presence of 1-butene prevents that the order in the alternation of right- and left-handed helical chains develops at high crystallization temperatures. Samples with contents of 1-butene higher than 70 mol % crystallize in structures similar to that of form I of syndiotactic poly(1-butene). Fiber samples of copolymers with small content of 1-butene (1-2 mol %) present the same behavior of syndiotactic polypropylene. Stretched fibers are in the trans planar form III of s-PP,which transforms into the isochiral helical form II of s-PP upon the release of the tension. Mixtures of crystals in forms I and II of s-PP are obtained by annealing. With increasing the 1-butene content only the antichiral helical form I of s-PP is observed in the stretched fibers of the copolymers, as well as upon the release of the tension. The presence of 1-butene units, for contents higher than 4 mol %, prevents the formation of the trans planar form III of s-PP by stretching. For these samples the formation of form I of s-PP, instead of the isochiral form II, either in the stretched fibers or upon the release of the tension, is a further evidence that the isochiral helical form II of s-PP can be obtained only from fibers initially in the trans planar form III, through a cooperative conformational transformation which induce the formation of helical chains having the same chirality

Screening for Tuberculosis in Health Care Workers. Experience in an Italian Teaching Hospital

Health care workers (HCW) are particularly at risk of acquiring tuberculosis (TB), even in countries with low TB incidence. Therefore, TB screening in HCW is a useful prevention strategy in countries with both low and high TB incidence. Tuberculin skin test (TST) is widely used although it suffers of low specificity; on the contrary, the in vitro enzyme immunoassay tests (IGRA) show superior specificity and sensitivity but are more expensive. The present study reports the results of a three-year TB surveillance among HCW in a large teaching hospital in Rome, using TST (by standard Mantoux technique) and IGRA (by QuantiFERON-TB) as first- and second-level screening tests, respectively. Out of 2290 HCW enrolled, 141 (6.1%) had a positive TST; among them, 99 (70.2%) underwent the IGRA and 16 tested positive (16.1%). The frequency of HCW tested positive for TB seems not far from other experiences in low incidence countries. Our results confirm the higher specificity of IGRA, but, due to its higher cost, TST can be considered a good first level screening test, whose positive results should be further confirmed by IGRA before the patients undergo X-ray diagnosis and/or chemotherapy

Melt-Crystallizations of α and γ Forms of Isotactic Polypropylene in Propene-Butene Copolymers

Random isotactic propene-butene copolymers (iPPC4) of different stereoregularity have been synthesized with three different homogeneous single center metallocene catalysts having different stereoselectivity. All samples crystallize from the polymerization solution in mixtures of α and γ forms, and the relative amount of γ form increases with increasing concentrations of butene and of rr stereodefects. All samples crystallize from the melt in mixtures of α and γ forms and the fraction of γ form increases with decreasing cooling rate. At high cooling rates, the crystallization of the α form is always favored, even for samples that contain high total concentration of defects that should crystallize in the γ form. The results demonstrate that in iPPs containing significant concentrations of defects, such as stereodefects and comonomeric units, the γ form is the thermodynamically stable form of iPP and crystallizes in selective conditions of very slow crystallization, whereas the α form is the kinetically favored form and crystallizes in conditions of fast crystallization

Il supporto di QField per l’implementazione dei dati in tempo reale: il caso dei Siti Reali borbonici nella provincia di Caserta

Il presente contributo prende in esame l’applicazione per sistemi Android denominata QField e le sue potenzialità per l’attività da svolgere durante i rilievi in campo. Tale applicazione, sviluppata dall’applicazione GIS-desktop QuantumGIS, consente di acquisire o integrare i dati geografici o attributo durante le attività di indagine sul campo. La sua affidabilità e versatilità è stata testata nell’ambito di un progetto relativo ai siti reali borbonici, ossia le proprietà acquisite dalla Casa Reale a partire dal XVIII secolo nei dintorni di Napoli e nella limitrofa “Terra di Lavoro”

Diffuse Supravalvular Aortic Stenosis: Surgical Repair in Adulthood

We present the case of a 54-year-old woman in which a diffuse congenital supravalvular aortic stenosis (SVAS) was associated with a severe aortic valve incompetence and heavy calcification of the aortic annulus. Repair consisted in resection of the ascending aorta, patch augmentation of the hypoplastic aortic root and annulus, placement of a 20 mm Dacron tubular graft (Vascutek, Renfrewshire, UK) and aortic valve replacement with a mechanical prosthesis (Sorin, Turin, Italy). Follow-up echocardiography demonstrated normal prosthetic valve function and a postoperative three-dimensional computed tomographic scan showed a normal shape of the reconstructed ascending aorta