1,721,004 research outputs found
Nuove tecnologie in classe : cosa è cambiato?,
No full textAbstract. Nel corso degli ultimi decenni le nuove tecnologie, e in particolare il computer, hanno avuto un forte sviluppo e come hanno iniziato a far parte della nostra vita quotidiana così sono entrati anche a far parte della realtà scolastica. La ricerca didattica da tempo si è concentrata sul problema dell’utilizzazione dei computer in classe, cercando di capire come sfruttare in modo conveniente le loro potenzialità in ambito didattico e avanzando una ricca collezione di proposte didattiche.
La ricerca descritta in questo articolo ha come scopo l’analisi dell’effetto che l’introduzione delle nuove tecnologie ha avuto nella pratica scolastica, a questo scopo si è concentrata sul rapporto tra le metodologie di utilizzo del computer e i possibili cambiamenti avvenuti nei modelli educativi – pedagogici di riferimento dei docenti; in particolare, si è cercato di mettere in evidenza i cambiamenti introdotti dagli insegnanti nella pratica scolastica in relazione all’uso delle nuove tecnologie e al grado di efficienza loro attribuito, come supporto alla didattica della matematica
Severe withdrawal syndrome in three newborns subjected to continuous opioid infusion and seizure activity dependent on brain hypoxia--ischemia. A possible link.
No full textBACKGROUND: The aim of this investigation was to verify whether brain hypoxia represented a risk factor for the occurrence and severity of opioid abstinence syndrome. METHODS: Three newborns who manifested seizure activity as a result of hypoxia, focal brain ischemia, and hypoxia and sepsis, respectively, were compared with 17 neonates who suffered from hypoxia without developing seizure activity. RESULTS: The first three neonates suffered a severe withdrawal syndrome (a rating on the neonatal abstinence score>17), the others did not. CONCLUSIONS: It is hypothesized that brain hypoxia facilitated the occurrence and severity of the withdrawal syndrome because some key neurochemical processes (such as N-methyl-D-aspartate activation, protein kinase C activation and nitric oxide production) are common to both phenomena
A System-theoretic Note on Model-Based Actor-Critic
No full textIn this paper, we provide preliminary results toward the direction of using systems theory tools for the design and analysis of reinforcement learning algorithms. Specifically, we analyze the convergence properties of a model-based scheme with an actor-critic structure. The distinctive feature of our scheme is that the actor and critic updates are equipped with auxiliary variables that allow for the use of a constant step size. Although idealized due to the assumption on access to the underlying Markov Decision Process (MDP), the investigated setting is a starting point toward a genuine (model-free) actorcritic scheme. A key contribution is the interpretation of this algorithmic framework in terms of discrete-time, interconnected dynamical systems. Specifically, by resorting to Singular Perturbations (S P), we reinterpret the whole algorithm as the interconnection of a fast subsystem (auxiliary variables' mechanism), an intermediate one (critic), and a slow one (actor). We separately analyze three auxiliary systems each corresponding to one of the identified subsystems. These preparatory results, combined with SP and LaSalle arguments, allow us to prove that the overall method asymptotically converges to a problem stationary point. Some numerical simulations confirm our theoretical findings
Neonatal anesthesia for major thoracic surgery
No full textNeonatal anesthesia for major thoracic surger
Bronchoscopy in newborns with esophageal atresia
No full textThe aim was to evaluate the influence of rigid laryngotracheo-bronchoscopy in newborns with oesophageal atresia (OA) and tracheoesophageal fistula (TOF) in preventing complications, improving diagnosis and surgical treatment. Among 76 consecutive newborns, received in the Paediatric Intensive Care Unit (PICU) from January 1990 to September 2001 with prenatal o perinatal suspected OA, forty-five had one or more other congenital anomalies. They were divided in I Montreal's risk group for 73.7% (56) and in the II one for 26.3% (20). Endoscopic procedure was performed in the operating room with Storz's rigid ventilating bronchoscope just before surgery, in all babies. With bronchoscopic examination we were able to identify the level, number and size of TOF and to visualise anatomical variants in 76 children. 15 children with OA had a gasless abdomen, but an upper pouch fistula was found only in three cases. In another four cases bronchoscopy confirmed the diagnosis of an "H" fistula and cervical surgical approach was established. One case had only oesophageal stenosis. 56 patients had fistula in lower pouch and in the last 38 cases we proceeded with selective transtracheal fistula incannulation and then we provided gastric drainage. One quadriforcation, 2 triforcations, 3 aberrant right upper lobe bronchi, 1 congential subglottic stenosis and 1 associated with a congenital subglottic stenosis and 1 left main bronchus agenesia were detected. No complications were correlated to the procedure and no babies had early pneumonia. Continuous feeding was achieved in 70 out of 76 patients: 46 primary anastomosis with 12 staged repairs (OA I and II type long gap), 4 resections of TEF, 8 oesophagocoloplasty. Nine babies (11.8%) did not survive. Clinical follow-up was possible in all the survivors. Mortality rate in the high-risk patients with OA remains high because of the many complications that may occur. Tracheal endoscopy is useful in improving the diagnostic approach and to prevent pulmonary complications. Fistula incannulation minimizes the risk of gastric distension and its detrimental effect on ventilation, helping the surgeon to identify TEF easily and quickly. Moreover, the endoscopic approach offers obvious advantages for the anaesthesiologist and the surgeon and has proven, in our experience, to be effective
Analisi critica sui criteri di scelta dell'assistenza respiratoria postoperatoria immediata su 200 pazienti trasferiti al reparto di rianimazione.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analisi della correlazione lineare fra ETCO2 e la gittata cardiaca in varie condizioni sperimentali.
No full textContrast enhanced ultrasound in children with blunt abdominal trauma: diagnostic performance
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