Motor learning by field approximation

We investigated how human subjects adapt to forces perturbing the motion of their ams. We found that this kind of learning is based on the capacity of the central nervous system (CNS) to predict and therefore to cancel externally applied perturbing forces. Our experimental results indicate: (i) that the ability of the CNS to compensate for the perturbing forces is restricted to those spatial locations where the perturbations have been experienced by the moving arm. The subjects also are able to compensate for forces experienced at neighboring workspace locations. However, adaptation decays smoothly and quickly with distance from the locations where disturbances had been sensed by the moving limb. (ii) Our experiments also how that the CNS builds an internal model of the external perturbing forces in intrinsic (muscles and / or joints) coordinates.     

Value of early variables as predictors of short-term outcome in patients with acute focal cerebral ischemia

The pathogenesis of essential thrombocythemia as a clonal myeloproliferative disorder has been clearly established. However, there continues to be considerable controversy concerning the management of this disease, particularly because its natural history is consistent with a nearly normal life expectancy. Therapeutic decisions have been complicated by a reliance on largely anecdotal, retrospective experience in the medical literature and, until very recently, an absence of prospective, controlled clinical trials. A recent study of patients with essential thrombocythemia at high risk of thrombosis because of advanced age or previous history of thrombotic complications demonstrated that platelet cytoreduction with hydroxyurea is effective in reducing thrombotic complications. Other cytoreducing agents that have been used in this disease include alkylating agents, recombinant interferon alpha, and anagrelide. The use of antiplatelet therapy is also controversial, and is most highly effective in patients with digital or cerebrovascular ischemic problems.     

Simplified analytical models for compressed concrete columns confined by FRP and FRCM system

In order to consider the response of concrete columns confined by FRP and FRCM system, proper models have to be formulated. In this context the present paper shows a generalized criterion for the determination of the increase in strength, in ductility and in dissipated energy for varying corner radius ratio of the cross section and fiber volumetric ratio. The procedure is based on the best fitting of several experimental data and unlike the usual empirical approaches available in the literature, the proposed technique relates the confinement effectiveness to a single parameter representative of the relative stiffness between the original concrete core and the reinforcement system. Furthermore, the proposed analytical models overcomes the limit of many empirical or semi-empirical models given in the literature that are applicable only to specific cases. A comparison with same available models confirm the reliability of the proposed procedure.     

Local instability and oscillations of trajectories in a diluted symmetric neural network

Using a generalized version of the signal-to-noise analysis, we study local instabilities of trajectories for the parallel dynamics of an extremely diluted, symmetric, Hopfield neural network. In order to reach a better understanding of the structure of the attractors of this model, a revision of the asymmetric version is performed in the case of zero and non-zero temperatures. New unexpected dynamical behaviours are found. Moreover, despite accepted beliefs, both analytical and numerical deviations between the dynamical properties of the two models (symmetric and asymmetric) can be exhibited. We show that, in some range of parameters, the diluted symmetric network exhibits strong dynamical oscillations of the neuronal activity, similar to those observed in synchronized networks. Furthermore, a deeper knowledge of the structure near attractors is achieved from this stability/instability analysis thanks to explicit analytical formulae for a two-step parallel dynamics for a symmetric network.     

Corticosteroids in liver and urine in Sicilian cattle by a LC-MS/MS method

The presence of corticosteroid residues was assessed in urine and liver samples from livestock of Sicily. A total of 630 bovine samples were collected from farms and slaughterhouses. The samples were analysed using solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS). All the corticosteroids found were under the maximum residue limit imposed by Commission Regulation (EC) 37/2010. About 4% of liver samples showed dexamethasone levels above the limit of detection (LOD), with a mean of 1.5 ± 0.2 µg kg^?1. Betamethasone was found only in seven liver samples, with a mean of 1.6 ± 0.1 µg kg^?1. Furthermore, prednisolone and prednisone were found only in urine and liver samples from slaughterhouse, probably related to the high rate of stress for bovines. These results suggest good control practices adopted by Sicilian farms, able to ensure the quality of food products.     

The autochrome process

Abstract

The autochrome was the first successful commercial colour process. It was invented by Louis and Auguste Lumiere at the tum of the century, patented in 1903 and produced until the 1950s on a sheet film called ‘Filmcolor’. Many articles were published between 1903 when the autochrome process was unveiled to the public, and 1935 when the decline of the screen process began and the first colour films with chromogenic development appeared. There are detailed deseriptions of the plate's range of use, its characteristies and processing, but these publications are very sketchy as to the nature of the components. The most detailed documents, on which this article is based, are the ‘report on the titles and work of Louis Lumiere’ published in 1918, the factory notebooks written by Louis Lumiere or M. Perrigot,¹ and the archives of the Lumiere firm, which are now scattered in various locations.     

Regulation of the expression of peripheral benzodiazepine receptors and their endogenous ligands during rat sciatic nerve degeneration and regeneration: a role for PBR in neurosteroidogenesis

This study addresses (1) the relationship between headache presence/intensity at time of testing and neurocognitive performance, and (2) the probability that testing triggers or intensifies pain. Subjects were 125 patients with chronic posttraumatic headache (mean = 2.67 years post injury) who completed a 4-hour test battery emphasizing memory. Comparisons of 34 individual tests/subtests and the five Wechsler Memory Scale-Revised (WMS-R) indices of relative memory impairment for 73 patients with no headache or mild headache versus 52 patients with moderate to severe pain revealed no significant differences. Testing intensified existing headaches for 55% but triggered headache for only 1 of 20 (5%; P =.00003). Results support the validity of neuropsychological test performance regardless of pain level, although testing can be painful.     

Incidence of cervical intraepithelial neoplasia grade III, and cancer of the cervix uteri following a negative Pap-smear in an opportunistic screening

224 patients with a recent diagnosis of chronic lymphocytic leukemia, confirmed by immune phenotype, were studied with a mean follow-up of 16 months. The median age was 72 years and the ratio of men to women was 1.51. An incidental diagnosis because of leukocytosis was made in 75% of the patients; in only 22% was the diagnosis related to symptoms. 80% were in stage A, 7.5% in stage B, and 12.5% in stage C. A relation was found between advanced stage and the number of lymphocytes in the blood, the percentage of lymphocytes in the bone marrow, WHO performance status, bacterial infection and disease-related mortality. Thus, six patients in stage C (21%) died because of infection (septicaemia or pneumonia), as opposed to only one out of 196 patients in stages A and B. The incidence of bacterial infection was 64% in stage C, as compared to 8.3% in stage A. Treatment with chlorambucil, started in 59 patients, was in accordance with the guidelines of the national programme for 52 of them. In contrast, a strict indication for prednisone (autoimmune cytopenia) was found in only 42% of 42 patients given this treatment.