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A Reinforcement Learning Model of Reaching Integrating Kinematic and Dynamic Control in a Simulated Arm Robot.

The paper investigates the Italian debate on municipalization between the 1880s and the 1920s and is divided in two parts. The first deals with the emrgence of municipalization in the late nineteenth century as a component in the birth of the Social State. The second part concerns the anlytical tools elaborated by some leading Italian economists in the first three decades of the twentieth century, with an early expanding stage (until World War I) and a later stage (under Fascism) of prevalent stagnation.

Recent evidence shows that perceiving objects automatically activates the representation of their affordances. For example, the experiments on compatibility effects show that the reaction time needed to categorise an object by producing a certain hand grip is faster if the requested response is compatible with the affordance elicited by the size of the object (e.g., a small or a large grip). The article presents a neural-network architecture that provides a general framework to account for this kind of effects. The model was designed with a methodological approach that aims to provide increasingly general accounts of brain and behaviour (the approach uses four sources of constraints: neuroscientific data, behavioural data, functioning within embodied systems, and reproduction of learning processes). The model is based on four principles of brain organisation that underlie most compatibility effects. First, visual perception and action are organised in the brain along a dorsal neural pathway, which encodes affordances, and a ventral pathway, which encodes goals. Second, the prefrontal cortex within the ventral pathway gives a top-down bias to action selection by integrating information on stimuli, context, and goals. Third, reaction times depend on dynamic neural competitions for action selection, which integrate bottom-up and top-down sources of information. The congruence/incongruence between the information related to affordances and current goals explains the different reaction times found in the experiments. Fourth, because words referring to objects trigger "internal simulations" of their referents, they can cause compatibility effects similarly to objects. We validated the model by reproducing and explaining three types of compatibility effects and showed its heuristic power by producing two testable predictions. We also assessed the explicative power of the model on the basis of a critical comparison with related models and showed how it could be extended to account for other compatibility effects by relying on the aforementioned four principles.

Background Osteoporotic vertebral fractures (VFs) often go unrecognised in both healthy individuals and in pathological conditions. Few data exist on VFs in patients hospitalised in Internal Medicine Units (IMUs), who often suffer from multiple concomitant chronic disorders. Aim of the study This multicentre cross-sectional study was aimed at assessing the prevalence of VFs in an unselected population of patients referring to IMUs. Correlations between VFs and the main coexisting diseases were also investigated. Methods Information on demographic, clinical and laboratory findings, and on the presence of known risk factors for osteoporosis was recorded. The Genant's semi-quantitative method was used to evaluate, in a central reading centre, the presence and severity of VFs in the thoracic and lumbar spine. Results A cohort of 995 patients was evaluated. At least one VF of any grade was found in 47.5% of patients, with similar prevalence between females (48.1%) and males (46.7%). Older age, chronic obstructive pulmonary disease, and previous diagnosis of osteoporosis showed a significant association with VFs in multivariable analysis. However, 79.7% of the VFs were observed in patients without previous diagnosis of osteoporosis. Moreover, a VF of grade 2 or greater was found in 20.8% of patients. Conclusions Fragility VFs is a very frequent finding in patients hospitalised in IMUs. Consequently, more attention should be devoted in this clinical setting to this comorbidity, which is known to be an additional factor for mortality and, when localised in the thoracic part of the spine, may negatively influence a concomitant respiratory insufficiency.

We report on the first laser emission of (Lux Gd(1-x))3 Ga5O12 doped with Tm3+ ions obtaining a slope efficiency of 20% and a maximum output power of 170 mW centered at 2013 nm. Evidences of a multiline emission are shown. Moreover a spectroscopic investigation on six samples of (Lux Gd(1-x))3 Ga5O12:Tm3+ having different Lu concentrations is presented. In particular the stark sublevels energy of 3H6 and 3F4 manifolds have been determined. Spectroscopic data have been utilized to calculate absorption and emission cross sections and gain curves.

Keywords: Glycine betaine, compatible solutes, salt stress, light intensity, durum wheat. Glycine betaine (GB) not only acts as an osmoregulator, but interacts with both hydrophilic and hydrophobic domains of macromolecules stabilizing their structures and activities and maintaining the integrity of membranes against the damaging effects of abiotic stresses. In many halophytes, GB and/or proline concentrations in leaves contribute to the osmotic pressure in the cell as a whole. In glycophytes their concentrations are much lower but, if partitioned exclusively to the cytoplasm, they could generate a significant osmotic pressure and function to balance vacuolar osmotic potential. In this study, we determined the effects of both salinity and high light on durum wheat seedlings, with a special emphasis on the potential role of GB in their protection. Very unexpectedly it appeared that high light treatments inhibit the synthesis of GB, even in the presence of salt stress. In order to understand the mechanisms underlying such result, we investigated the effects of different light intensities on the transcripts encoding enzymes involved in its synthesis. Moreover, additional solutes susceptible to compensate the decrease in GB were followed over this range of light treatments.

Background: Traditionally, pneumonia has been classified as either community- or hospital-acquired. Although only limited data are available, health care–associated pneumonia has been recently proposed as a new category of respiratory infection. “Health care–associated pneumonia” refers to pneumonia in patients who have recently been hospitalized, had hemodialysis, or received intravenous chemotherapy or reside in a nursing home or long-term care facility. Objective: To ascertain the epidemiology and outcome of community-acquired, health care–associated, and hospital-acquired pneumonia in adults hospitalized in internal medicine wards. Design: Multicenter, prospective observational study. Setting: 55 hospitals in Italy comprising 1941 beds. Patients: 362 patients hospitalized with pneumonia during two 1-week surveillance periods. Measurements: Cases of radiologically and clinically assessed pneumonia were classified as community-acquired, health care–associated, or hospital-acquired and rates were compared. Results: Of the 362 patients, 61.6% had community-acquired pneumonia, 24.9% had health care–associated pneumonia, and 13.5% had hospital-acquired pneumonia. Patients with health care–associated pneumonia had higher mean Sequential Organ Failure Assessment scores than did those with community-acquired pneumonia (3.0 vs. 2.0), were more frequently malnourished (11.1% vs. 4.5%, and had more frequent bilateral (34.4% vs. 19.7%) and multilobar (27.8% vs. 21.5%) involvement on a chest radiograph. Patients with health care–associated pneumonia also had higher fatality rates (17.8% [CI, 10.6% to 24.9%] vs. 6.7% [CI, 2.9% to 10.5%]) and longer mean hospital stay (18.7 days [CI, 15.9 to 21.5 days] vs. 14.7 days [CI, 13.4 to 15.9 days]). Logistic regression analysis revealed that depression of consciousness (odds ratio [OR], 3.2 [CI, 1.06 to 9.8]), leukopenia (OR, 6.2 [CI, 1.01 to 37.6]), and receipt of empirical antibiotic therapy not recommended by international guidelines (OR, 6.4 [CI, 2.3 to 17.6]) were independently associated with increased intrahospital mortality. Limitations: The number of patients with health care–associated pneumonia was relatively small. Microbiological investigations were not always homogeneous. The study included only patients with pneumonia that required hospitalization; results may not apply to patients treated as outpatients. Conclusion: Health care–associated pneumonia should be considered a distinct subset of pneumonia associated with more severe disease, longer hospital stay, and higher mortality rates. Physicians should differentiate between patients with health care–associated pneumonia and those with community-acquired pneumonia and provide more appropriate initial antibiotic therapy.

We simulated organisms with an arm terminating with a hand composed by two fingers, a thumb and an index, each composed by two segments, whose behavior was guided by a nervous system simulated through an artificial network. The organisms, which evolved through a genetic algorithm, lived in a bidimensional environment containing four objects, either large or small, either grey or black. In a baseline simulation the organisms had to learn to grasp small objects with a precision grip and large objects with a power grip. In Simulation 1 the organisms learned to perform two tasks: in Task 1 they continued to grasp objects according to their size, in Task 2 they had to decide the objects' color by using a precision or a power grip. Learning occured earlier when the grip required to respond to the object and to decide the color was the same than when it was not, even if object size was irrelevant for the task. The simulation replicates the result of an experiment by Tucker & Ellis (2001) suggesting that seeing objects automatically activates motor information on how to grasp them.

Background: Few studies linking hospital discharge records with the population register of chronic dialysis (CD) patients are available. This study aimed to evaluate the frequency and the determinants of hospitalization, taking into account the demographic, clinical and biochemical data. Methods: We conducted a retrospective cohort study in 3411 patients starting dialysis from 1996-2000, reported to the Lazio Dialysis Registry (RDL) (Italy). These patients were linked with the hospital information system from 1996-2002. Hospital admission probability was calculated using the Kaplan-Meier method. To evaluate the determinants of hospitalization risk we used Cox's proportional hazards for the first admission and a marginal model considering competitive effect of mortality, the Wei-Lin-Weissfeld model, for any admission. Results: We found 7530 hospital admissions, referring to 1711 patients (50.7%), with a rate of 63/100 person-years. The most prevalent diagnoses were "diseases of the genitourinary system", (37.4%), and "diseases of the circulatory system", among secondary diagnoses (46.6%). Hospitalization probability was 34.4% at 1 yr after starting dialysis. The risk of first and any hospital admission was higher (p

Mirror neurons may play a role in representing not only signs but also their meaning. Since actions are the only aspect of behavior which is inter-individually accessible, interpreting meanings in terms of actions might explain how meanings can be shared. Behavioral evidence and Artificial Life simulations suggest that seeing objects or processing words referring to objects automatically activates motor actions.

Covalent modifications of the core histone tails, includind acetylation, methylation, phosphorylation, ADP-ribosylation and ubiquitination govern the chromatine accessibility and create binding surfaces for protein recognition (such as the bromodomain far acetylated lysines and the chromodomain for methylated lysines), therefore dictating the rate of gene transcription. We investigated the impact of p210 bcr-abl tyrosine kinase of chronic myeloid leukemia (CMLl) on the acetylation and methylation at individual lysine residues within the NH2-terminal tails of histone H4, an integral component of transcriptional competence at the onset of S phase. To the purpose, we used RP-HPLC coupled with electrospray mass spectrometry (LCMS) to resolve the single H4 species (non-acetylated and mono-, di- or three-acetylated) and enzymatic digestion coupled with MALDI mass spectrometry to define the individuai lysine residues involved in acetylation and methylation processes. In single cell clones generated from the murine myeloid 32D cell line transducing a temperature-sensitive (ts) p210 bcr-abl construct (that owns constitutive tyrosine kinase activity at the permissive temperature of 33°C, but lacks it at the non- permissive temperature of 39°C) the inhibition of p210 bcr-abl tyrosine kinase induced by 1 M STI571 was associated with a significant (p

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We demonstrate passive Q-switching (PQS) of the Tm-doped BaY2F8 (Tm:BYF) laser for the first time. The Tm:BYF laser is diode-pumped using an L-shaped hemispherical resonator. In the cw regime, the maximum output power with an 18% Tm-doped BYF crystal reached 1.12 W at ~1920 nm for an absorbed pump power of 3.06 W. In the PQS regime, maximum pulse energy (720 μJ) and peak power (17.1 kW) were obtained with an 8% Tm-doped BYF crystal and a Cr:ZnS saturable absorber with 92% low-signal transmission, again near 1920 nm, for a pulse width of ~40 ns and a repetition rate of 50 Hz.

We report the first observation to our knowledge of room-temperature continuous-wave laser operation on the I-5(7) -> I-5(8) transition of Ho3+ ions in a KY3F10 single crystal. Using a Tm-doped silica fiber laser operating at 1938 nm as a pump source, a maximum laser power of 1.8 W was obtained at a wavelength of similar to 2040 nm for 27 W of absorbed pump power with a slope efficiency of 19.1% with respect to absorbed power. At low cavity output coupling, the lasing wavelength shifted to 2060.5 nm. The beam propagation factor (M-2) was measured to be

La socialita? e? fondamentale per gli esseri umani non solo perche? molto del comportamento umano e? comportamento sociale ma perche? la cognizione individuale umana e? essa stessa in gran parte il frutto di processi sociali. La socialita? da? la sua forma alla mente soprattutto attraverso il linguaggio, e le capacita? cognitive superiori umane sono in gran parte il frutto della trasformazione dei processi cognitivi di base - per lo piu? condivisi con gli altri mammiferi - come effetto dell'internalizzazione di relazioni e pratiche sociali che passano attraverso il linguaggio. In questo contributo facciamo alcuni esempi di come l'internalizzazione del linguaggio possa modificare la cognizione umana, in particolare rispetto alla categorizzazione, all'apprendimento, all'astrazione ed alla memoria. Inoltre, accenniamo a come la socialita? influenzi la mente umana anche al di la? del linguaggio e discutiamo brevemente il ruolo che i modelli computazionali possono giocare nello studio delle influenze sociali sulla cognizione individuale.