8,392 research outputs found
Tecniche contrastografiche nello studio dell'esofago del cavallo
No full textLa diagnosi delle patologie esofagee nel cavallo viene formulata sulla base di segni clinici e di esami collaterali, quali endoscopia, indagini radiografiche dirette e con mezzo di contrasto (MdC). Scopo di questa comunicazione è descrivere le tecniche e le metodiche radiologiche per lo studio dell'esofago in condizioni normali e patologiche, sottolineandone possibilità e limiti per un possibile impiego clinico
Venezia di notte. Frontiera della colonizzazione turistica o spazio-tempo per pratiche sociali? Venice by night. Frontier of tourist colonization or space-time for social practices?
No full textGrowing tourist flows, continuous depopulation, rising tension between locals and visitors are three of the most severe issues affecting Venice’s historic centre. The aim of this paper is to explore if Venice’s night is a spatiotemporal frontier for touristification and if the re-interpretative practices of urban spaces and the expression of the “right to the city” occur during the night. The analysis develops a taxonomy of evening and night-time social activities in urban outdoor spaces and employs a qualitative methodological frame based on an ethnographic fieldwork structured through focused surveys and participant observation. In particular, the analysis focuses on urban night practices in the area of campo San Giacomo da l’Orio
Growth and endocrine function in thalassemia major in childhood and adolescence
No full textBackground: Thalassemia major is an inherited hemoglobin disorder characterized by chronic anemia and iron overload due to transfusion therapy and gastrointestinal absorption. Iron overload causes most of the associated mortality and morbidity and frequently involves the endocrine glands. Aim: To review the most pertinent literature on the topic. Methods: One hundred and twenty-three papers were evaluated. Results: Disproportionate short stature is frequent and becomes more evident at puberty because of the lack of growth spurt. Later on, partial height recovery may occur. Long-term treatment with recombinant human GH seems ineffective to improve final height. Pubertal development is characterized by a clinical spectrum ranging from hypogonadism to a simple delay in starting and developing of puberty. Hormonal replacement is mandatory in cases of absent or arrested puberty. Pancreatic beta-cells function may be impaired during adolescence or later on. Its impairment ranges from hyperinsulinemia, secondary to insulin resistance, with normal glucose tolerance to beta-cells failure with insulin-dependent diabetes mellitus. Primary hypothyroidism may affect thalassemic patients from the second decade of life. The thyroid dysfunction may be reversible (if an intensive chelation therapy regimen is started in the precocious phase), stationary, or slowly progressive. Central hypothyroidism is less common and autoimmune thyroiditis absent. Conclusion: Despite the improvement of the treatment, the involvement of the endocrine system still burdens the life of these patients. Further therapeutic improvement would reasonably reduce morbidity and, hopefully, mortality of thalassemic patients and make the endocrine disorders easier to treat. (J. Endocrinol. Invest. 33: 61-68, 2010) (c) 2010, Editrice Kurti
Measurement of Ds- --> tau- anti-neutrino_tau and a new limit for B- --> tau- anti-neutrino_tau
No full textUsing a data sample of 1 475 000 Z → qq̄(γ) events collected during 1994 with the L3 detector at LEP, we have studied the purely leptonic decays of heavy flavour mesons, and . A signal is observed in the invariant mass distribution M(γDs−) corresponding to the decay sequence , , . The branching fraction for decays is measured to be . No signal of decays is observed in the data, corresponding to an upper limit on the branching franction at 90% CL
Design of an efficient 900 GHz antenna in standard CMOS technology for imaging arrays
No full textThis paper describes and addresses the challenges that are encountered while designing a 900 GHz antenna for FET detectors using a standard submicron CMOS technology. The reduced metal stack, the problem of surface waves and technology-related rules are taken into account in order to properly design an efficient antenna, with the objective to couple it to field-effect transistor (FET) detectors in a focal-plane array configuration. Simulations on a 0.15-μm standard CMOS technology show that up to 58% efficiency with responsivity in the several kV/W range can be achieved.Accepted author manuscriptTera-Hertz Sensin
4 Pi Beta Counter
No full textThis pillbox design of 4-pi proportional flow radioactivity counter was designed and tested by Howard H. Seliger and Lucy M. Cavallo of the National Bureau of Standards (NBS) in 1951, following a suggestion by C. J. Borkowski of Oak Ridge National Laboratory, made in June 1949 at a meeting of the Subcommittee on Beta and Gamma Ray Measurements and Standards of the Committee on Nuclear Science of the National Academy of Sciences National Research Council. The radioactivity counter design consisted of two 2-pi counters mounted face to face, separated by a thin stainless steel diaphragm with peripheral holes for the passage of the methane counter gas. The tubes in the upper half of the device served as inlets for the gas, which was withdrawn from the bottom of the device. During operation of the counter, a thin deposit of source material was mounted on a Formvar-polystyrene film, which was cemented over a 2-cm hole in the central diaphragm. Operation was in the region of limited proportionality where the gas gain and the electronic gain were about 10^4 and 5 x 10^3, respectively. The pillbox radioactivity counter made possible the high-efficiency counting of beta particles from radioactive materials with activities as low as 10 nuclear transitions per second. The device was durable, easily decontaminated, and proved to be stable over long periods of time. It was used to calibrate sources of 14^C, 22^Na, 24^Na, 35^S, 60^Co, 90^Sr+90^Y, and 198^Au. After some years of use, the pillbox design was superseded first by a 4-pi proportional flow counter with a cylindrical form, and later by a counter with a spherical form.[H] 12 cm [Diam] 16 cm [L] 31 c
Constructing Bridges between Computational Tools in Heterogeneous and Homogeneous Catalysis
No full textBetter catalysts are needed to address numerous challenges faced by humanity. In this Perspective, we review concepts and tools in theoretical and computational chemistry that can help to accelerate the rational design of homogeneous and heterogeneous catalysts. In particular, we focus on the following three topics: (1) identification of key intermediates and transition states in a reaction using the energetic span model, (2) disentanglement of factors influencing the relative stability of the key species using energy decomposition analysis and the activation strain model, and (3) discovery of new catalysts using volcano relationships. To facilitate wider use of these techniques across different areas, we illustrate their potentials and pitfalls when applied to the study of homogeneous and heterogeneous catalysts
Résistance et renaissance de la vitiviniculture dans la Lagune de Venise
No full textThe article analyzes the historical and the present developments of viticulture in Venice and its lagoon. The particularities of viticulture in this area linked to the particular environmental context are highlighted, as well as its close links with the numerous religious communities historically present in the city. As regards today's conditions, the particular role of voluntary associations in the conservation and enhancement of winegrowing lagoon spaces and wine production is highlighted
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