1,045 research outputs found
Metodi di valutazione delle pubblicazioni elettroniche stato dell'arte e prospettive
Online access to scientific literature leads to new ways of evaluation. Next to the evaluated literature, new spaces for grey literature have been opened. The process of peer review can become clear and shared. For journals and articles, a new criterion of evaluation based on the number of “motivated” accesses can be made up. However, the pros and cons of these new methods have to be pointed out. This paper is my word in the debate on the objective value of online scholarly publications analysed from the point of view of the user. It is the product of a fruitful collaboration between two university librarians and a professor who has been working for many years in scientific national and international laboratories. They all manage the Biblioteca Digitale of La Sapienza in Rome. What is important is the need to choose sources addressed to users who learn and produce scientific material in a quantitatively and economically detailed way. The argumentation includes the general, but not all-embracing, field of the experimental sciences.
The starting point of this work is the need to verify the influence of the digital library on the IF. Did the digital library support or nullify the value of the IF as the evaluation paradigm in order to do better choices while buying? Considering the data, IF seems not enough to evaluate the value of a journal and it has to be implemented with the statistical analysis of the effective use of the journals.
In the end, we present schematically a few points and we give a couple of suggestions to the community of librarians and professors which nowadays is working, theoretically and practically, in the management of the digital libraries in Italian scientific institutions
Structure, rotational dynamics, and superfluidity of small OCS-doped He clusters
The structural and dynamical properties of OCS molecules solvated in Helium
clusters are studied using reptation quantum Monte Carlo, for cluster sizes
n=3-20 He atoms. Computer simulations allow us to establish a relation between
the rotational spectrum of the solvated molecule and the structure of the He
solvent, and of both with the onset of superfluidity. Our results agree with a
recent spectroscopic study of this system, and provide a more complex and
detailed microscopic picture of this system than inferred from experiments.Comment: 4 pages. TeX (requires revtex4) + 3 ps figures (1 color
Mid-level Priming by Completion vs. Mosaic Solutions
We report two experiments on the role of mid-level processes in image segmentation and completion. In the primed matching task of Experiment 1, a cue!prime sequence was presented before the imperative stimulus consisting of target shapes with positive versus negative contour curvature polarity and one versus two axes of mirror symmetry. Priming shapes were included in two composite occlusion displays with the same T-junction information and different geometric features supporting a distinct balance between completion and mosaic solutions. A cue, either congruent or incongruent with targets, preceded the presentation of the composite priming display. Matching performance was affected by primes in the expected direction, while cue congruency participated only in a marginally significant three-way interaction, and prime duration had no effect. In Experiment 2, the cue!prime sequence was replaced by a fixation cross to control for the priming effect obtained in Experiment 1. The study confirmed that contour connectability and curvature polarity are effective structural factors capable of competing with symmetry in mid-level image segmentation and completion processes
Long-term radiographic and clinical-functional outcomes of isolated, displaced, closed talar neck and body fractures treated by ORIF: the timing of surgical management
Background: The main purpose of this retrospective case series study was to evaluate long-term radiographic and clinical outcomes of a consecutive series of patients diagnosed with isolated, displaced, closed talar neck or body fractures treated by open reduction and internal fixation (ORIF). Secondly, the aim was to verify the influence of the location of talar fractures on the outcomes, the prognostic value of the Hawkins sign, whether operative delays promote avascular necrosis (AVN) and if the fractures require emergent surgical management.
Methods: From January 2007 to December 2012, at our institution, 31 patients underwent ORIF through the use of screws. On the basis of Inokuchi criteria, the injuries were divided between neck and body fractures, which were classified according to Hawkins and Sneppen, respectively. The patients included were divided into two groups in relation to fracture location and complexity. Radiographic assessment focused on reduction quality, bone healing, the Hawkins sign and post-traumatic arthritis (PTA) development. For the clinical evaluation, clinical-functional scores (AOFAS Ankle-Hindfoot Score; MFS; FFI-17; SF-36) and VAS were determined, and statistical analysis was performed.
Results: 27 patients, 19 males and 8 females, mean age 38.3 years, were included with an average follow-up period of 83.2 months (range 49\u2013119). There were 9 neck and 19 body fractures; their reduction was anatomical or nearly anatomical in 22 cases, and all reached radiographic consolidation after a mean period of 3.4 months (range 1.7\u20137). The Hawkins sign was observed in 9 cases, in which necrosis did not develop. With a 0\u201311 day surgical timing interval, more than 60% of the patients obtained good or fair results with different scores, while 18 (66.7%) were completely satisfied (VAS: 9\u201310). The early complications included malunions (21.4%) and wound problems (25%); the late complications involved AVN (25%) and PTA (78.6%).
Conclusions: Despite a high rate of long-term complications, satisfactory clinical results were achieved. Talar fracture location did not influence the outcomes, the Hawkins sign was confirmed as a positive prognostic factor, and operation timing did not influence AVN development. Hence, these injuries do not require emergent surgical management by ORIF
Metodi di valutazione delle pubblicazioni elettroniche stato dell'arte e prospettive
Online access to scientific literature leads to new ways of evaluation. Next to the evaluated literature, new spaces for grey literature have been opened. The process of peer review can become clear and shared. For journals and articles, a new criterion of evaluation based on the number of “motivated” accesses can be made up. However, the pros and cons of these new methods have to be pointed out. This paper is my word in the debate on the objective value of online scholarly publications analysed from the point of view of the user. It is the product of a fruitful collaboration between two university librarians and a professor who has been working for many years in scientific national and international laboratories. They all manage the Biblioteca Digitale of La Sapienza in Rome. What is important is the need to choose sources addressed to users who learn and produce scientific material in a quantitatively and economically detailed way. The argumentation includes the general, but not all-embracing, field of the experimental sciences.
The starting point of this work is the need to verify the influence of the digital library on the IF. Did the digital library support or nullify the value of the IF as the evaluation paradigm in order to do better choices while buying? Considering the data, IF seems not enough to evaluate the value of a journal and it has to be implemented with the statistical analysis of the effective use of the journals.
In the end, we present schematically a few points and we give a couple of suggestions to the community of librarians and professors which nowadays is working, theoretically and practically, in the management of the digital libraries in Italian scientific institutions
Implementation and Control of the Velvet Fingers: a Dexterous Gripper with Active Surfaces
Since the introduction of the first prototypes of
robotic end-effectors showing manipulation capabilities, much
research focused on the design and control of robot hand and
grippers. While many studies focus on enhancing the sensing
capabilities and motion agility, a less explored topic is the
engineering of the surfaces that enable the hand to contact
the object.
In this paper we present the prototype of the Velvet Fingers
smart gripper, a novel concept of end-effector combining
the simple mechanics and control of under-actuated devices
together with high manipulation possibilities, usually offered
only by dexterous robotic hands. This enhancement is obtained
thanks to active surfaces, i.e. engineered contact surfaces able
to emulate different levels of friction and to apply tangential
thrusts to the contacted object. Through the paper particular
attention is dedicated to the mechanical implementation, sense
drive and control electronics of the device; some analysis on
the control algorithms are reported. Finally, the capabilities
of the prototype are showed through preliminary grasps and
manipulation experiment
Symptomatic pseudoarthrosis secondary to a stress fracture of the acromion
Summary. Fractures of the acromion are uncommon clinical entities, and stress fractures are even more rare, with few cases reported. Due to their rarity, stress fractures are often misdiagnosed. Here, we report a case of an elderly patient with an acromion stress fracture, which was overlooked, resulting in nonunion followed by the displacement of the distal portion of the acromion. The purpose of this report was to discuss this rare fracture, highlighting the importance of an accurate evaluation of radiological imaging as well as clinical data
Long-term survival in patients undergoing cardiac resynchronization therapy: the importance of performing atrio-ventricular junction ablation in patients with permanent atrial fibrillation
Aims To investigate the effects of cardiac resynchronization therapy (CRT) on survival in heart failure (HF) patients with permanent atrial fibrillation (AF) and the role of atrio-ventricular junction (AVJ) ablation in these patients. Methods and results Data from 1285 consecutive patients implanted with CRT devices are presented: 1042 patients were in sinus rhythm (SR) and 243 (19%) in AF. Rate control in AF was achieved by either ablating the AVJ in 118 patients (AVJ-abl) or prescribing negative chronotropic drugs (AF-Drugs). Compared with SR, patients with AF were significantly older, more likely to be non-ischaemic, with higher ejection fraction, shorter QRS duration, and less often received ICD back-up. During a median follow-up of 34 months, 170/1042 patients in SR and 39/243 in AF died (mortality: 8.4 and 8.9 per 100 person-year, respectively). Adjusted hazard ratios were similar for all-cause and cardiac mortality [0.9 (0.57-1.42), P = 0.64 and 1.00 (0.60-1.66) P = 0.99, respectively]. Among AF patients, only 11/118 AVJ-abl patients died vs. 28/125 AF-Drugs patients (mortality: 4.3 and 15.2 per 100 person-year, respectively, P < 0.001). Adjusted hazard ratios of AVJ-abl vs. AF-Drugs was 0.26 [95% confidence interval (CI) 0.09-0.73, P = 0.010] for all-cause mortality, 0.31 (95% CI 0.10-0.99, P = 0.048) for cardiac mortality, and 0.15 (95% CI 0.03-0.70, P = 0.016) for HF mortality. Conclusion Patients with HF and AF treated with CRT have similar mortality compared with patients in SR. In AF, AVJ ablation in addition to CRT significantly improves overall survival compared with CRT alone, primarily by reducing HF deat
Laser remote sensing calibration of ocean color satellite data
world ocean: in fact, those processes dramatically affect the climatic equilibrium of our planet. For this reason, many advanced active and passive remote sensors have been used to study phytoplankton dynamics, since such phenomena are thought to be responsible for the sequestration of atmospheric carbon dioxide, one of the most important greenhouse gases. In this paper, one laser system and three satellite radiometers routinely used for the study of the phytoplankton dynamics will be briefly reviewed. Satellite sensors have been preferred to airborne sensors because, to our knowledge, ocean color airborne radiometers have not been operated in Antarctica, at least not throughout the whole lapse of time examined in this study. Particular focus was on the laser system (ELF) and on a specific satellite radiometer (SeaWiFS). ELF is based on the laser-induced fluorescence of phytoplankton pigments and was conceived for the Italian expeditions to Antarctica. The goal of SeaWiFS is to provide the Earth science community with quantitative data on the global ocean bio-optical properties. Such satellite radiometer has been calibrated with in situ data mainly acquired in non polar regions. This is why a comparison between ELF and SeaWiFS measurements of chlorophyll-a surface concentrations in the Southern Ocean during the austral summer 1997-1998 was believed to be significant. Our results indicate that SeaWiFS overestimates high concentrations and underestimates low concentrations. In order to correct this behavior, the chlorophyll- a bio-optical algorithm of SeaWiFS has been recalibrated according to the measurements of ELF, thus providing a new estimation of the primary production in the Southern Ocean
I.S.Mu.L.T. Achilles Tendon Ruptures Guidelines
This work provides easily accessible guidelines for the diagnosis, treatment and rehabilitation of Achilles tendon ruptures. These guidelines could be considered as recommendations for good clinical practice developed through a process of systematic review of the literature and expert opinion, to improve the quality of care for the individual patient and rationalize the use of resources. This work is divided into two sessions: 1) questions about hot topics; 2) answers to the questions following Evidence Based Medicine principles. Despite the frequency of the pathology andthe high level of satisfaction achieved in treatment of Achilles tendon ruptures, a global consensus is lacking. In fact, there is not a uniform treatment and rehabilitation protocol used for Achilles tendon ruptures
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