Anticoagulant therapy with fondaparinux in a liver transplant patient with thrombosis and liver fibrosis: a case report

The treatment with fondaparinux is the effective and safe anticoagulant therapy in liver transplant patient on immunosuppressive therapy with arterial thrombosis, and it seems able to reduce liver fibrosis. Although this treatment is not generalizable, further prospective large studies need to confirm this case report

Speculations on the clinical significance of asymptomatic viral infections

A detailed understanding of asymptomatic chronic viral infections is critical to analyse their pathogenesis, assess the severity and burden of disease and, where required, optimize public health control measures. Recent studies on herpesviruses showed that the hostevirus interactions are modulated by coinfections, emphasizing the relevance of co-infections in determining the clinical expression (from asymptomatic to symptomatic infections) and the severity of herpesvirus-associated diseases (either neoplastic or infectious diseases). To demonstrate causality between viruses (virome) and diseases, Koch's postulates should be adapted adding new knowledge on hostemicrobe relationship and microbial interactions. In the present review we aim to provide an update on asymptomatic chronic infections and criteria for causality and on the virological, immunological and hostevirus interactions in asymptomatic chronic infections in human hosts, focusing on herpetic infections

Language acquisition and universal grammar : a survey of recent research

openDipartimento di discipline linguistiche, comunicative e dello spettacoloCONSULTABILE PRESSO IL DIPARTIMENT

Study and design of Turbo and Low-Density Parity-Check Codes decoder architectures for high-rate flexible communication systems

This PhD dissertation proposes the ASIC design of a flexible Multi-Standard channel decoder for next generation mobile devices. Nowadays the demand of multi-standard applications is becoming a must for the worldwide user. In such a scenario, a wide range of contents can be provided by integrating onto the same device the support of different communication protocols, both satellite and terrestrial. Flexibility is then the keyword in the design of modern modems and particular attention must be paid to the implementation of the advanced channel coding techniques which represents the most challenging task in terms of computational complexity, speed and power consumption. Among the channel decoding schemes, Turbo and LDPC codes are the preferred choice due to the remarkable error correction performance. To the best of our knowledge, the proposed ad-hoc architecture is the first attempt to design a flexible Multi-Standard channel decoder using an ASIC technology. This represents a very powerful innovation w.r.t. the state-of-the-art channel decoders which are mainly based on application-specific instruction set processor (ASIPs). Actually, an ASIC implementation allows the support of different decoding schemes through the real-time re-configuration of its own hardware resources thus attaining optimized performance in terms of speed area and power consumption. The BCJR algorithm was identified as the unified basic decoding algorithm since this represents the common choice of the Turbo codes and at the same time the basic engine of the so-called LDPC Turbo-Decoding Message-Passing. The error correction performance were then evaluated by developing an high level model both in floating and fixed point domain in order to select the most suitable configuration as a trade-off between performance and implementation complexity. Targeting high throughput application the architecture is parallelized by using two different data schedules. On one hand, several distinct data frames can be decoded in parallel through the so-called multi-MAP decoding. On the other hand one single frame is decoded in a parallel manner with the so-called multi-SISO decoding. The power consumption is optimized at two different levels. At the hardware level the resources not used during a particular decoding process are switched off by means of the clock-gating technique. At the algorithmic level stopping rules are employed so as to halt the decoding process as soon as the estimated received word is considered correct. Although a generalization to all the modern communication standards can be easily attained, a proof-of-concept channel decoding platform fully compliant with the IEEE 802.16e, IEEE 802.11n, 3GPP’s and DVB-SH standards was developed. The architecture was then synthesized on a 45 nm CMOS standard-cell library with an operating frequency of 150 MHz. As a result an area of 0.90 mm2 and a maximum power consumption of 86.1 mW was attained and favourably compared with other state-of-the-art solutions

Prescribed mean curvature flow of non-compact space-like Cauchy hypersurfaces

In this paper we consider the prescribed mean curvature flow of a non-compact space-like Cauchy hypersurface of bounded geometry in a generalized Robertson–Walker space-time. We prove that the flow preserves the space-likeness condition and exists for infinite time. We also prove convergence in the setting of manifolds with boundary. Our discussion generalizes previous work by Ecker, Huisken, Gerhardt and others with respect to a crucial aspects: we consider any non-compact Cauchy hypersurface under the assumption of bounded geometry. Moreover, we specialize the aforementioned works by considering globally hyperbolic Lorentzian space-times equipped with a specific class of warped product metrics

Heat-type equations on manifolds with fibered boundary I: Schauder estimates

In this paper we prove parabolic Schauder estimates for the Laplace-Beltrami operator on a manifold $M$ with fibered boundary and a $\Phi$-metric $g_\Phi$. This setting generalizes the asymptotically conical (scattering) spaces and includes special cases of magnetic and gravitational monopoles. This paper, combined with part II, lay the crucial groundwork for forthcoming discussions on geometric flows in this setting; especially the Yamabe- and mean curvature flow.Comment: 33 pages, 7 figure

Euclid and the scientific thought in the third century B.C.

The criticism on the texts of Euclid, even assuming different positions, starts generally from the previous assumption that the author of the Elements is  totally inside the Platonic-Aristotelian tradition. The thesis affirmed in this paper is that many of the gaps and contradictions found by the criticism have their root in this assumption. The authors assert that Euclid was a scientist that belonged in a full way to the new cultural climate of the Hellenistic Kingdoms, and particularly of the Alexandria’s Museum. In this climate, characterized by lively philosophical disputes, the scientists, and in particular Euclid, tend to obtain coherent and stable results, voluntarily omitting to give their opinion on the real being of the scientificobject and on the truth of the principles

Fixed-point MAP decoding of channel codes

This paper describes the fixed-point model of the maximum a posteriori (MAP) decoding algorithm of turbo and low-density parity-check (LDPC) codes, the most advanced channel codes adopted by modern communication systems for forward error correction (FEC). Fixed-point models of the decoding algorithms are developed in a unified framework based on the use of the Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. This approach aims at bridging the gap toward the design of a universal, multistandard decoder of channel codes, capable of supporting the two classes of codes and having reduced requirements in terms of silicon area and power consumption and so suitable to mobile applications. The developed models allow the identification of key parameters such as dynamic range and number of bits, whose impact on the error correction performance of the algorithm is of pivotal importance for the definition of the architectural tradeoffs between complexity and performance. This is done by taking the turbo and LDPC codes of two recent communication standards such asWiMAX and 3GPP-LTE as a reference benchmark for a mobile scenario and by analyzing their performance over additive white Gaussian noise (AWGN) channel for different values of the fixed-point parameters