1,721,023 research outputs found
Competition under non-linear pricing: the optimal entry tax with a public firm
No full textUniversity of Edinburgh Discussion Paper in Economic
Velocity estimation of Grandes Jorasses glacier in the framework of GlaRiskAlp project
No full textThe Grandes Jorasses hanging glacier, located at 4100 m asl above a populated area, is monitored by Fondazione Montagna sicura since 2007, on account of the Geological Service of the Aosta Valley Autonomous Region. The serac dynamic shows a periodic trend of mass increasing, interrupted by a collapse: The collapse is preceded by an exponential acceleration that lasts few days, as revealed in 1997-98 by Prof. M Funk (ETH Zurich). By tracking the velocity of the ice mass it is therefore possible to forecast its breakdown. At the early stage of the project the native monitoring system consisted of poles with prisms placed on the glacier surface, monitored by an automatic total station (motorized total station) sited at the valley bottom. During bad weather conditions the system could loss measurements, so alternative monitoring systems were designed, installed and tested in the framework of the GlaRiskAlp project (Alcotra program). In particular the new monitoring systems consisted of a low cost, single frequency, GNSS wireless sensors network, able to trace continuously (H24) the receivers positions to measure the displacement in real time, and a seismometer at the top of the glacier was placed in order to follow the seismic activity (that is proportional to the velocity). Furthermore, in order to better characterize the mass evolution, photogrammetric activities were carried out to reconstruct the glacier surface. Prototypes, results and outlooks of these monitoring systems for Grandes Jorasses glacier will be presente
Acoustic parameters of voluntary cough in healthy non-smoking subjects
No full textOBJECTIVE:
The aim of this study was to explore cough in healthy subjects.
METHODOLOGY:
We studied 234 coughs generated by 24 (12 males) healthy non-smokers (forced expiratory volume in 1 s (FEV1) 103+/-8% of predicted), who had no significant differences in FEV1 and age between males and females. For each subject, several bouts of voluntary coughing were recorded using a personal computer with an A/D converter (sampling rate 10 kHz, 8 bit resolution) and the first and second coughs of each bout were analysed using short-time Fast Fourier Transformation. For each cough we studied the three phases that are produced. In particular, we studied the duration of the three parts, loudest frequency in the first part, lowest and highest frequencies, number of continuous frequencies and lowest and highest continuous frequencies in the second part, and the loudest frequency of the third part if present.
RESULTS:
We found significant differences between males and females in length of the first part (41.4+/-14 vs 44.7+/-10.4 msec, P = 0.04), loudest frequency of the first part (362+/-145 vs 449+/-145 Hz), lowest frequencies (282+/-100 vs 348+/-135 Hz) and highest continuous frequencies (3877+/-571 vs 4147+/-362 Hz; P < 0.001) of the second part. An interesting finding was that healthy males and females had the same number of continuous frequencies. Different frequencies are probably a consequence of anatomical differences in airway geometry involved in the cough.
CONCLUSION:
In cough frequency spectrum studies the differences between the two sexes should be taken into account to reduce the variability of the results.OBJECTIVE:
The aim of this study was to explore cough in healthy subjects.
METHODOLOGY:
We studied 234 coughs generated by 24 (12 males) healthy non-smokers (forced expiratory volume in 1 s (FEV1) 103+/-8% of predicted), who had no significant differences in FEV1 and age between males and females. For each subject, several bouts of voluntary coughing were recorded using a personal computer with an A/D converter (sampling rate 10 kHz, 8 bit resolution) and the first and second coughs of each bout were analysed using short-time Fast Fourier Transformation. For each cough we studied the three phases that are produced. In particular, we studied the duration of the three parts, loudest frequency in the first part, lowest and highest frequencies, number of continuous frequencies and lowest and highest continuous frequencies in the second part, and the loudest frequency of the third part if present.
RESULTS:
We found significant differences between males and females in length of the first part (41.4+/-14 vs 44.7+/-10.4 msec, P = 0.04), loudest frequency of the first part (362+/-145 vs 449+/-145 Hz), lowest frequencies (282+/-100 vs 348+/-135 Hz) and highest continuous frequencies (3877+/-571 vs 4147+/-362 Hz; P < 0.001) of the second part. An interesting finding was that healthy males and females had the same number of continuous frequencies. Different frequencies are probably a consequence of anatomical differences in airway geometry involved in the cough.
CONCLUSION:
In cough frequency spectrum studies the differences between the two sexes should be taken into account to reduce the variability of the results
Multimedia presentation of lung sounds as a learning aid for medical students
No full textNew educational technologies might help to compensate for the decrease in time and emphasis dedicated to physical examination in medical training. This may, in particular, be applicable for improving the skills in auscultation of the chest. We investigated whether a multimedia presentation of acoustic and graphic characteristics of lung sounds could improve the learning of pulmonary auscultation by medical students, in comparison with conventional teaching methods. We studied 48 medical students without clinical experience, who had received conventional formal teaching on chest examination. Chest auscultation skills were evaluated using an inaccuracy score for the student's auscultation report on three patients, selected according to a standardized procedure. After a baseline evaluation, 27 students in groups of 5-10, participated in a multimedia seminar on lung sounds during which digitized lung sounds were played and the corresponding time-expanded waveform and frequency spectrum were commented on and displayed on a computer. The remaining 21 students received conventional bedside training, acting as control group. The following week, all the students underwent a second evaluation of chest auscultation skills. No differences in the inaccuracy score were observed between the two groups in the preliminary test. However, in the second postintervention assessment, the inaccuracy score of the students who had followed the seminar (11.2 +/- 1.3 points) was significantly lower than that of the controls (16.6 +/- 1.6 points). The answers to a feedback questionnaire confirmed that the great majority of the students found the association of the acoustic signals with their visual image to be useful for learning and understanding lung sounds.(ABSTRACT TRUNCATED AT 250 WORDS
Rischi glaciali in Valle d'Aosta. Monitoraggio e ricerca applicata
No full textI fenomeni di origine glaciale rappresentano una fonte di rischio importante nelle aree
di montagna e nelle Alpi in particolare. Il rischio deriva dall’interazione tra le dinamiche
glaciali, molto attive ed in rapida evoluzione anche – ma non solo – in relazione al
cambiamento climatico, e la presenza antropica, in forte espansione nelle aree alpine
nell’ultimo secolo. I principali rischi di origine glaciale derivano dal crollo di seracchi,
dal collasso di ghiacciai temperati e dal rilascio improvviso di acqua accumulata nei
ghiacciai stessi. Il territorio valdostano, per le sue caratteristiche, è particolarmente
soggetto a tali rischi. Per questa ragione l’amministrazione regionale, tramite la Fondazione
montagna sicura, ha attuato un piano di monitoraggio specifico per il rischio
glaciale. Il piano si articola in diverse azioni, sia a livello dell’intero territorio sia per il
monitoraggio di casi specifici
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