1,721,019 research outputs found
Vander : Fisiologia
No full textQuesto testo rappresenta la prima edizione italiana di un’opera, giunta alla XII edizione in lingua inglese, che si caratterizza per la felice coesistenza di due caratteristiche raramente presenti entrambe in un unico trattato: la sintesi e la completezza. Un’esposizione ricca, ben organizzata, in cui i concetti complessi sono presentati con semplicità e chiarezza.
Estremamente aggiornato, il testo presenta la fisiologia in un’ottica integrata ed è corredato da numerosi cenni di fisiopatologia e da riferimenti all’anatomia che precedono la descrizione degli aspetti funzionali. Inoltre ogni capitolo è concluso da un caso clinico relativo agli argomenti trattati per permettere al lettore di sviluppare conoscenze di fisologia applicata, con un approccio problem based learning che vada oltre la normale acquisizione delle nozioni presentate nel testo. Sempre a questo scopo, l’ultimo capitolo è costituito da una raccolta di quattro casi clinici più complessi che integrano tra loro gli argomenti discussi nel testo.
Molto significativo è anche l'insieme di risorse dedicate alla verifica autonoma dell’apprendimento: al termine di ogni sezione sono presenti domande di ripasso sugli argomenti appena affrontati, mentre al termine di ogni capitolo si trovano numerosi test di autovalutazione e domande di ragionamento e calcolo. Inoltre, tutti i capitoli sono arricchiti da domande di fisiologia, più strutturate, la cui risposta richiede un’efficace comprensione degli argomenti trattati e una buona capacità di integrazione degli stessi. Le risposte di tutte le domande e di tutti i test sono presentate alla fine dei capitoli o in appendice.
L’apparato iconografico è particolarmente ricco e assolutamente aggiornato, e facilita notevolmente l’apprendimento di una materia non sempre intuitiva.
Infine, in fondo al volume è presente un glossario che raccoglie i termini tecnici più significativi, dei quali viene fornita definizione per permettere allo studente di richiamarne immediatamente il significato
From morphological heterogeneity at alveolar level to the overall mechanical lung behavior: an in vivo microscopic imaging study.
Full text linkIn six male anesthetized, tracheotomized, and mechanically ventilated rabbits, we imaged subpleural alveoli under microscopic view (60×) through a "pleural window" obtained by stripping the endothoracic fascia and leaving the parietal pleura intact. Three different imaging scale levels were identified for the analysis on increasing stepwise local distending pressure (P ld) up to 16.5 cmH2O: alveoli, alveolar cluster, and whole image field. Alveolar profiles were manually traced, clusters of alveoli of similar size were identified through a contiguity-constrained hierarchical agglomerative clustering analysis and alveolar surface density (ASD) was estimated as the percentage of air on the whole image field. Alveolar area distributions were remarkably right-skewed and showed an increase in median value with a large topology-independent heterogeneity on increasing P ld. Modeling of alveolar area distributions on increasing P ld led to hypothesize that absolute alveolar compliance (change in surface area over change in P ld) increases fairly linearly with increasing initial alveolar size, the corollary of this assumption being a constant specific compliance. Clusters were reciprocally interweaved due to their highly variable complex shapes. ASD was found to increase with a small coefficient of variation (CV <25\%) with increasing P ld. The CV of lung volume at each transpulmonary pressure was further decreased (about 6\%). The results of the study suggest that the considerable heterogeneity of alveolar size and of the corresponding alveolar mechanical behavior are homogenously distributed, resulting in a substantially homogenous mechanical behavior of lung units and whole organ
Alveolar mechanics studied by in vivo microscopy imaging through intact pleural space.
No full textIn six male anesthetized, tracheotomized, and mechanically ventilated rabbits we derived indications on alveolar mechanics from in vivo imaging, using a "pleural window" technique (pleural space intact) that allows unrestrained movement of the same subpleural alveoli (N=60) on increasing alveolar pressure from 4 to 8 cmH2O. Absolute compliance (C(abs), ratio of change in alveolar surface area to the change in alveolar pressure) was significantly lower in smaller compared to larger alveoli. Specific compliance, C(sp), obtained by normalizing C(abs) to alveolar surface area, was essentially independent of alveolar size. Both C(abs) and C(sp) were affected by large variability likely reflecting the complex matching between elastic and surface forces. We hypothesize that the relative constancy of C(sp) might contribute to reduce interregional differences in parenchymal and surface forces in the lung tissue by contributing to assure a uniform stretching in a model of mechanically inter-dependent alveoli
Prevalência e ciclo evolutivo de Isospora felis Wenyon, 1923 e I. rivolta (Grassi, 1879) Wenyon, 1923 em gatos Prevalence and intestinal cycle of Isospora felis Wenyon, 1923 e I. rivolta (Grassi, 1879) Wenyon, 1923 in the domestic cat
Full text linkFoi levantada a prevalência de "I. felis" (24,0%), de "I. rivolta" (14,4%) e de infecções mistas (15,2%) em 125 gatos da Guanabara e do Rio de Janeiro, Brasil. Foi estudado o ciclo endógeno desses coccídios no epitélio intestinal. A "I. felis" se caracteriza pelo seu maior tamanho e pelo maior número de merozoítos e microgametos; e a "I. rivolta" por evoluir freqüentemente junto à lâmina própria, e quando isto não acontece, pelo seu menor tamanho em relação a "I. felis". Não foi conseguida a infecção de 3 cães desmamados e 4 recém-nascidos com as Isospora do gato. De 20 gatos com isosporose, apenas 2 deram reação de Sabin-Feldman positiva (1:16 e 1:64 respectivamente).In 125 domestic cats from Guanabara and Rio de Janeiro state, Brasil, the following prevalence of Isospora was met: "I. felis", 24.0; "I. rivolta", 14.44%; and infections by both parasites, 15,2%. "I. felis" is characterized by its larger size and by a greater number of merozoites and microgametocytes and by its evolution in the epithelial cells of the intestine between the nuclei and the brush border. "I. rivolta" has a smaller size than "I. felis" and frequently envolves between the nuclei and the basal membrane. The sabin-Feldman rection in 20 cats with isosporosis was negative in 18. One cat had a weakly positive reaction (1:16) an another a positive reaction (1:64). Cat faeces stored in potassium dichromate at 2.5% with "I. felis" and/or "I. rivolta" were twice administered "per os" to seven puppies and didn't produce Isospora infection
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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