172 research outputs found
Studio di sistemi di navigazione biologici per il controllo della traiettoria di volo in alcune specie di uccelli
No full textSapersi muovere con efficienza è fondamentale per tutti gli esseri viventi. Gli uccelli sono abili navigatori del cielo e, per orientarsi, utilizzano diversi tipi di bussole naturali e un orologio circadiano che gli consente di compensare i cambiamenti giornalieri dovuti alla rotazione terrestre. Essi sono in grado di immagazzinare, in una mappa cognitiva, le informazioni percepite durante i vari voli effettuati; queste possono derivare da riferimenti sia di tipo visivo, che di altro genere, come odori e geomagnetismo, e consentono ai volatili di ritrovare facilmente la strada di casa.
Gli uccelli, inoltre, sono in grado di percepire il flusso ottico proveniente da un paesaggio pieno di irregolarità (come può esserlo una foresta o una superficie ondosa marina); grazie ad esso possono controllare con precisione l'altitudine di volo a bassa quota e possono individuare ostacoli nelle immediate vicinanze in modo da evitare collisioni.
Durante le migrazioni capita di volare a quote più elevate per cercare di risparmiare energie e, in questo caso, gli uccelli possono controllare la loro altitudine con un errore all'incirca di 10m, poiché sono in grado di percepire direttamente le variazioni di pressione atmosferica. Per risparmiare energie sono molto abili nello sfruttare la forza dei venti e nel compensarne la deriva.
Gli uccelli possiedono diverse abilità che spiegano la loro impressionante capacità di navigazione e quindi rappresentano un ottimo spunto per apprendere diverse tecniche in modo da migliorare i nostri metodi di orientamento ed elaborazione dei dati
Laparoscopic re-sleeve gastrectomy as a treatment of weight regain after sleeve gastrectomy
No full textAim: To evaluate laparoscopic re-sleeve gastrectomy as a treatment of weight regain after Sleeve. Methods: Laparoscopic sleeve gastrectomy is a common bariatric procedure. Weight regain after long-term follow-up is reported. Patients were considered for laparoscopic re-sleeve gastrectomy when we observed progressive weight regain and persistence of comorbidities associated with evidence of dilated gastric fundus and/or antrum on upper gastro-intestinal series. Follow-up visits were scheduled at 1, 3, 6 and 12 mo after surgery and every 6 mo thereafter. Measures of change from baseline at different times were analyzed with the paired samples t test. Results: We observed progressive weight regain after sleeve in 11 of the 201 patients (5.4%) who had a mean follow-up of 21.1 ± 9.7 mo (range 6-57 mo). Three patients started to regain weight after 6 mo following Sleeve, 5 patients after 12 mo, 3 patients after 18 m. Re-sleeve gastrectomy was always performed by laparoscopy. The mean time of intervention was 55.8 ± 29.1 min. In all cases, neither intra-operative nor post-operative complications occurred. After 1 year follow-up we observed a significant (P < 0.05) mean body mass index reduction (-6.6 ± 2.7 kg/m(2)) and mean % excess weight loss (%EWL) increase (+31.0% ± 15.8%). An important reduction of antihypertensive drugs and hypoglycemic agents was observed after re-sleeve in those patients affected by hypertension and diabetes. Joint problems and sleep apnea syndrome improved in all 11 patients. Conclusion: Laparoscopic re-sleeve gastrectomy is a feasible and effective intervention to correct weight regain after sleeve
Ecological impact of isolated cognitive relapses in MS
No full textIsolated cognitive relapses (ICRs) are transient deficits in cognitive performance that are the only presentation of a multiple sclerosis (MS) relapse. Here, we evaluated the impact of ICRs on cognitive difficulties in daily activities (assessed with the Multiple Sclerosis Neuropsychological Screening Questionnaire, Informant Version (MSNQ-I)) to characterize ICRs’ clinical relevance. We used 2-year-long retrospective data to compare 15 relapsing-remitting MS (RRMS) patients with ICRs with 57 RRMS patients presenting an asymptomatic gadolinium enhancing lesion (and no-ICRs). ICRs were associated not only with neuropsychological performance decline but also with an increase in the daily cognitive difficulties. These findings support the ecological relevance of ICRs
A working model on large-scale spatio-temporal organization of brain functioning and its implications for bipolar disorder
No full textA working model on large-scale spatio-temporal organization of brain functioning and its implications for bipolar disorde
Drinking water contamination from perfluoroalkyl substances (PFAS): An ecological mortality study in the Veneto Region, Italy
No full textBackground Perfluoroalkyl substances (PFAS), a heterogeneous group of highly stable man-made chemicals, have been widely used since 1960s and can be detected almost ubiquitously in all environmental matrices. In Italy, on January 2014, drinking water contamination in an area of the Veneto Region was detected mainly due to the drain of fluorinated chemicals by a manufacturing company operating since 1964. Methods The present ecological mortality study was aimed at comparing mortality for some causes of death selected on the basis of previous reported associations, during the period 1980-2013, in municipalities with PFAS contaminated and uncontaminated drinking water on the basis of the levels indicated by the Italian National Health Institute (ISS). Sex-specific number, standardized mortality rates and rate ratios (RR) for PFAS contaminated and uncontaminated areas were computed for each cause of death through the ENEA epidemiological database. Results In both sexes, statistically significant RRs were detected for all causes mortality, diabetes, cerebrovascular diseases, myocardial infarction and Alzheimer's disease. In females, RRs significantly higher than 1.0 were also observed for kidney and breast cancer, and Parkinson's disease. Increased risk, although not statistically significant, was observed for bladder cancer in both sexes, and for testicular cancer, pancreatic cancer and leukemia in males only. Conclusions Higher mortality levels for some causes of death, possibly associated with PFAS exposure, were detected in contaminated municipalities in comparison with uncontaminated ones with similar socioeconomic status and smoking habits. These results warrant further individual level analytic studies to delineate casual associations. © 2015 The Author
Autologous haematopoietic stem-cell transplantation in multiple sclerosis: benefits and risks
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