1,721,038 research outputs found
Dynamic user profiles and flexible queries in office document retrieval systems
No full textThe problem of document management in an Office Information System in view of supporting the decision process by a set of users with different knowledge, capabilities and requirements is considered. User profiles are used to improve the retrieval properties and a control system is outlined to automatically update the utility information used by the searching strategies. user requirements are modeled in Dynamic User Profiles in order to maintain accurate knowledge of the most promising approach to document search, of the interest fields, and of the favourite output format. An example of DUP use is provided adopting a flexible query specification to take advantage of database selection, retrieval via keyword, or full text scanning in a multi-strategy query processing approach. Actual queries are redefined by extracting the aspects suitable for each strateg
La disautonomia nel morbo di Parkinson puo' essere diagnosticata tramite monitoraggio ambulatoriale della pressione arteriosa nelle 24 ore.
No full textLA DISAUTONOMIA NEL MORBO DI PARKINSON PUO' ESSERE DIAGNOSTICATA TRAMITE MONITORAGGIO AMBULATORIALE DELLA PRESSIONE ARTERIOSA NELLE 24 ORE
G. Reeordati (1), F. Barbie (2), M. Gianni (3), R. Furlan (2)
(I) Istituto Medicina Cardiovascolare, Universita' ed Ospedate Maggiore, Milano (2) Unita' Sincopi, Med. Generale, Ospedale Bolognini, Seriate ed Universita' Milano (3) Ospedale Salvini, Garbagnate Milanese, P.O. Rho
La distribuzione nello spazio-di-fase di pressione arteriosa (PA) ed intervallo R-R dei valori raccolti tramite monitoraggio ambulatoriale nelle 24 ore puo' dare utili indicazioni sullo stato funzionale del sistema nervoso autonomo del singolo soggetto e di gruppi di pazienti. In soggetti giovani e sani, la usuale ipotensione e bradicardia notturna determinano la distribuzione del valori notturni in alto ed a sinistra dei valori diurni ed i valori nelle 24 ore seguono una retta di regressione con distribuzione parallela al cosidetto vettore di reciprocita' descritto per lo "Spazio Autonomico" da Berntson et al., (Psychophysiology, 1993; Recordati et al., Cl. Aut. Res., 2006). Nel presente lavoro abbiamo studiato la distribuzione dei valori di PA e di intervallo R-R ottenuti tramite monitoraggio ambulatoriale nelle 24 ore, in dieci pazienti affetti da morbo di Parkinson (PD) con ipertensione notturna ed ipotensione ortostatica diuma (age 73±3; 4 M) ed in dieci pazienti anziani sani. Mentre la distribuzione nello spazio-di-fase del pazienti anziani sani dimostrava ancora presente la normale reciprocita' simpato-vagale, nei PD i valori di PA e di intervallo RR registrati durante la notte si collocavano alla destra dei valori registrati durante il giorno e la retta di regressione per tutti i valori raccolti nelle 24 ore risultava parallela all'asse dell'ascissa (o vettore del "disaccoppiamento simpatico") senza alcuna evidenza di reciprocita' simpato-vagale, Questi dati sembrano indicare che nei PD con disautonomia vi e' una chiara perdita della reciprocita’ circadiana tra tono simpatico e vagale e che queste alterazioni possono essere prontamente rilevate con l'utilizzo di una tecnica semplice, poco costosa, e non invasiva, come il monitoraggio ambulatoriale della PA nelle 24 ore
Governance dynamics in multi-partner R & D alliances: integrating the control and coordination perspectives
No full textAssessment of the Autonomic Control of the Cardiovascular System by a Frequency Domain Approach
No full textThis chapter discusses how a frequency domain approach can be used to assess the autonomic control of the cardiovascular system. Power spectrum analysis based on Fast Fourier Transform (FFT) or autoregressive modeling (AR) provides the center frequency of rhythmic fluctuations of the different cardiovascular variables. Normalization procedure is obtained by dividing the absolute power of each oscillatory component by total variance and then multiplying by 100. Frequency domain analysis of heart rate and arterial pressure variability enabled to disclose subtle changes in the neural cardiovascular control that would be hidden when considering the simple variations of heart rate and blood pressure mean values. The high frequency (HF) component of systolic arterial pressure variability reflects the mechanical influence of respiratory activity. The other oscillatory component is indicated as low frequency (LF). The LF component of RR variability (LFRR) when expressed in normalized units (n.u.) reflects primarily the sympathetic efferent modulation of the sino-atrial node. Rhythmic discharge activity is a general property of the nervous system. A 0.1 Hz rhythmicity linked with low frequency fluctuations of RR interval and arterial pressure variability was found to characterize sympathetic neurons located in areas within the central nervous system involved in cardiovascular regulation
Do Work Accidents Play Any Role in the Increased Risk of Death Observed in 25- to 44-Year-Old Patients After Syncope?
No full text
Going 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
Stable isotope ratios in hair and teeth reflect biologic rhythms.
Full text linkBiologic rhythms give insight into normal physiology and disease. They can be used as biomarkers for neuronal degenerations. We present a diverse data set to show that hair and teeth contain an extended record of biologic rhythms, and that analysis of these tissues could yield signals of neurodegenerations. We examined hair from mummified humans from South America, extinct mammals and modern animals and people, both healthy and diseased, and teeth of hominins. We also monitored heart-rate variability, a measure of a biologic rhythm, in some living subjects and analyzed it using power spectra. The samples were examined to determine variations in stable isotope ratios along the length of the hair and across growth-lines of the enamel in teeth. We found recurring circa-annual periods of slow and fast rhythms in hydrogen isotope ratios in hair and carbon and oxygen isotope ratios in teeth. The power spectra contained slow and fast frequency power, matching, in terms of normalized frequency, the spectra of heart rate variability found in our living subjects. Analysis of the power spectra of hydrogen isotope ratios in hair from a patient with neurodegeneration revealed the same spectral features seen in the patient's heart-rate variability. Our study shows that spectral analysis of stable isotope ratios in readily available tissues such as hair could become a powerful diagnostic tool when effective treatments and neuroprotective drugs for neurodegenerative diseases become available. It also suggests that similar analyses of archaeological specimens could give insight into the physiology of ancient people and animals
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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