263 research outputs found

    Homodyne detection as a near-optimum receiver for phase-shift keyed binary communication in the presence of phase diffusion

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    We address binary optical communication channels based on phase-shift keyed coherent signals in the presence of phase diffusion. We prove theoretically and demonstrate experimentally that a discrimination strategy based on homodyne detection is robust against this kind of noise for any value of the channel energy. Moreover, we find that homodyne receiver beats the performance of Kennedy receiver as the signal energy increases, and achieves the Helstrom bound in the limit of large noise

    Matter-wave interferometry: towards antimatter interferometers

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    Starting from an elementary model and refining it to take into account more realistic effects, we discuss the limitations and advantages of matter-wave interferometry in different configurations. We focus on the possibility to apply this approach to scenarios involving antimatter, such as positrons and positronium atoms. In particular, we investigate the Talbot-Lau interferometer with material gratings and discuss in details the results in view of the possible experimental verification.Comment: 18 pages; 8 figure

    Apparent superluminal advancement of a single photon far beyond its coherence length

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    We present experimental results relative to superluminal propagation based on a single photon traversing an optical system, called 4f-system, which acts singularly on the photon's spectral component phases. A single photon is created by a CW laser light down{conversion process. The introduction of a linear spectral phase function will lead to the shift of the photon peak far beyond the coherence length of the photon itself (an apparent superluminal propagation of the photon). Superluminal group velocity detection is done by interferometric measurement of the temporal shifted photon with its correlated untouched reference. The observed superluminal photon propagation complies with causality. The operation of the optical system allows to enlighten the origin of the apparent superluminal photon velocity. The experiment foresees a superluminal effect with single photon wavepackets.Comment: 11 pages, 2 figure

    SEROEPIDEMIOLOGICAL SCREENING OF LEISHMANIA INFECTION IN DOGS AND CATS: THE ROLE OF THE VETERINARIAN IN A HIGHLY ENDEMIC AREA IN SICILY

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    BACKGROUND Leishmaniosis is a zoonotic disease caused by Leishmania spp. with a wide spectrum of clinical signs, lymphadenomegaly, skinocular lesions, weight loss, signs of renal failure [1,2]. Many subclinical cases of leishmaniasis without illness could play an important role in the maintenance of Leishmania infection in endemic areas. Veterinary surveillance of dogs/cats owners could help to update the seroprevalence status of Leishmania infantum infection in a random court of sick and apparently healthy dogs and cats from western Sicily (Bagheria and neighboring areas) using indirect fluorescent antibody test (IFAT). MATERIAL AND METHODS A total of 268 dogs and 9 cats living in western Sicily were randomly sampled during the 2020 year. Specific antibodies to L. infantum were detected using the IFAT against in-house cultured promastigotes. Leishmania strain was used as an antigen fixed on multispot microscope slides. The feline and canine sera were both prepared by serial 2-fold dilutions (1:40 to 1:5120) in phosphate buffered saline and added to the antigen-coated wells. Fluorescent anti-cat/anti-dog immunoglobulin G antibody was used for detection. CONCLUSION Western Sicily is an active focus for canine and feline leishmaniosis in the Mediterranean area. The results of the present study indicate a high exposure rate to Leishmania (about 33% dogs and 44% cats result positive or suspected) in a random population, suggesting that they are infected with L. infantum. Moreover, 5 dogs and 1 cat previously classified as apparently healthy were seropositive with a titer ā‰„1:160. In conclusion, veterinary surveillance of dogs/cats could help to control the increase of L. infantum infections, especially in areas of high endemicity. RESULTS 49/268 (18.3%) sampled dogs tested positive to IFAT with a titer ā‰„1:160 and 40/268 (15%) tested suspected (titers 1:40-1:80), for L.infantum infection (Table 1). An additional 2/9 (22.2%) cats were seropositive with a titer of 1:160 and 2/9 (22.2%) cats were seropositive with a titer of 1:80 (Table 1). Figure 1 shows geographical distribution of L. infantum seroprevalenc in dogs/cats sampled from western Sicily. CONCLUSION Western Sicily is an active focus for canine and feline leishmaniosis in the Mediterranean area. The results of the present study indicate a high exposure rate to Leishmania (about 33% dogs and 44% cats result positive or suspected) in a random population, suggesting that they are infected with L. infantum. Moreover, 5 dogs and 1 cat previously classified as apparently healthy were seropositive with a titer ā‰„1:160. In conclusion, veterinary surveillance of dogs/cats could help to control the increase of L. infantum infections, especially in areas of high endemicity

    SEROEPIDEMIOLOGICAL SCREENING OF LEISHMANIA INFECTION IN DOGS AND CATS: THE ROLE OF THE VETERINARIAN IN A HIGHLY ENDEMIC AREA IN SICILY

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    Western Sicily is an active focus for canine and feline leishmaniosis in the Mediterranean area. The results of the present study indicate a high exposure rate to Leishmania (about 33% dogs and 44% cats result positive or suspected) in a random population, suggesting that they are infected with L. infantum. Moreover, 5 dogs and 1 cat previously classified as apparently healthy were seropositive with a titer ā‰„1:160. In conclusion, veterinary surveillance of dogs/cats could help to control the increase of L. infantum infections, especially in areas of high endemicity

    EVALUATION OF RPMI-PY MEDIUM FOR TRYPANOSOMA CRUZI AND DIFFERENT LEISHMANIA SPECIES

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    Trypanosoma spp. and Leishmania spp. are causal agents of a number of parasitic diseases. Culture media can be divided into 3 main categories: semisolid, biphasic, and liquid. While biphasic and semisolid culture media need blood, an important factor for the reproduction of parasites, most liquid media require fetal calf serum or erythrocyte lysate. A culture media RPMI-PY demonstrated a good performance in terms of time and parasitic load of L. infantum compared to other culture media. The aim of the work was to evaluate the performance of RPMI-PY medium in different Leishmania species and also to evaluate in T. cruzi culture. RPMI-PY is likely to be valuable additions to laboratory practice in light of the relatively simple recipes, general availability of the components, and in terms of suitability because rabbit breeding is not necessary and the costs are lowered and can be used for all Leishmania species and to cultivate T. cruzi

    "Stilbene ST18, terfenile TR4 e carrier innovativi: effetti in cellule di Leishmania spp. ed in modelli sperimentali in vivo".

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    Convegno Nazionale I RISULTATI DELLā€™ATTIVITƁ DI RICERCA DELLā€™IZS SICILI

    Kinematic models of lower limb joints for musculo-skeletal modelling and optimization in gait analysis

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    Kinematic models of lower limb joints have several potential applications in musculoskeletal modelling of the locomotion apparatus, including the reproduction of the natural joint motion. These models have recently revealed their value also for in vivo motion analysis experiments, where the soft-tissue artefact is a critical known problem. This arises at the interface between the skin markers and the underlying bone, and can be reduced by defining multibody kinematic models of the lower limb and by running optimization processes aimed at obtaining estimates of position and orientation of relevant bones. With respect to standard methods based on the separate optimization of each single body segment, this technique makes it also possible to respect joint kinematic constraints. Whereas the hip joint is traditionally assumed as a 3 degrees of freedom ball and socket articulation, many previous studies have proposed a number of different kinematic models for the knee and ankle joints. Some of these are rigid, while others have compliant elements. Some models have clear anatomical correspondences and include real joint constraints; other models are more kinematically oriented, these being mainly aimed at reproducing joint kinematics. This paper provides a critical review of the kinematic models reported in literature for the major lower limb joints and used for the reduction of soft-tissue artefact. Advantages and disadvantages of these models are discussed, considering their anatomical significance, accuracy of predictions, computational costs, feasibility of personalization, and other features. Their use in the optimization process is also addressed, both in normal and pathological subjects
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