1,720,968 research outputs found
On the performance of a WDM ring network with multitoken interarrival time (MTIT) MAC protocol
No full textThe influence of aluminium availability on phosphate uptake in Phaseolus vulgaris L. and Phaseolus lunatus L.
No full textAluminium toxicity is one of the major limiting factors of crop productivity on acid soils. High levels of available aluminium in soil may induce phosphorus deficiency in plants. This study investigates the influence of Aluminium (Al) on the phosphate (P(i)) uptake of two Phaseolus species, Phaseolus vulgaris L. var. Red Kidney and Phaseolus lunatus L. The two bean species were treated first with solutions of Al at different concentrations (0, 25, 50 and 100microM, pH 4.50) and second with solutions of P(i) (150microM) at pH 4.50. The higher the Al concentration the higher the Al concentration sorbed but P. vulgaris L var. Red Kidney adsorbed significantly more Al than P. lunatus L. Both species released organic acids: P. vulgaris L var. Red Kidney released fumaric acid and P. lunatus L. fumaric and oxalic acids which could have hindered further Al uptake. The two bean species showed a sigmoid P(i) uptake trend but with two different mechanisms. P. vulgaris L var. Red Kidney showed a starting point of 3h whereas P. lunatus L. adsorbed P(i) immediately within the first minutes. In addition, P. vulgaris L var. Red Kidney presented significantly higher P(i) uptake (higher uptake rate 'k' and higher maximum adsorption 'a' of the kinetic uptake model). The Al treatments did not significantly influence P(i) uptake. Results suggest that P. lunatus L. might adopt an external Al detoxification mechanism by the release of oxalic acid. P. vulgaris L var. Red Kidney on the other hand seemed to adopt an internal detoxification mechanism even if the Al sorbed is poorly translocated into the shoots. More detailed studies will be necessary to better define Al tolerance and/or resistance of Phaseolus spp
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
COMBINATION OF VENOUS OCCLUSION PLETHYSMOGRAPHY AND D-DIMER TESTING IN PATIENTS WITH CLINICAL SUSPECTED DVT
No full textThe clinical diagnosis of lower limbs deep venous thrombosis (DVT) is
unreliable in more than 50% of patients: so it becomes necessary the use of di agnostic
tools. This study investigates the possibility of exclu sion of DVT in symptomatic
pati ent s obteining negative results from both D-Dimer (DD) and venous occlusion
pl ethysmography (V.O.P.
TVP E MALFORMAZIONI CAVALI: CASE REPORT
No full textLa trombosi venosa profonda spesso é la manifestazione più evidente di una
patologia sottostante e, solo se accurate indagini di laboratorio e strumentali escludono tale
patologia, la trombosi venosa pub essere definita idiopatica.
E' necessario quindi, in assenza di L1na causa ben evidente di trombosi venosa, sottoporre il
paziente ad accertamenti.
Spesso viene rilevato un deficit della coagulazione; qualche volta la trombosi venosa é la prima
manifestazione di una neoplasia, altre volte é sostenuta da malattie del collagene.
Qualche volta può essere conseguenza di patologia malformativa sconosciuta fino al momento
della manifestazione trombotica.
Sono descritti casi, infatti, di malformazione della vena cava inferiore esorditi con trombosi venosa profonda
LE LESIONI ULCEROSE NEL PAZIENTE CON ISCHEMIA CRITICA E CONCOMITANTE PATOLOGIA VENOSA
No full textLa presenza di lesioni ulcerose nel paziente con ischemia critica non trattabile con
rivascolarizzazione diretta è un quadro di difficile soluzione che si aggrava ulteriormente se vi è
concomitante ipertensione venosa. In questo caso infatti la stasi a livello del "versante venoso"
del microcircolo porta ad un'ulteriore riduzione della perfusione tissutale che conduce ad un
ulteriore aggravamento dell'ischemi
COLECISTECTOMIA LAPAROSCOPICA: INDICAZIONI ALLA COLANGIOGRAFIA INTRA-OPERATORIA
No full textL'indicazione assoluta o relativa
alla colangiografia intra-operatoria in corso di
colecistectomia laparoscopica rimane un argomento
dibattuto, in virtù della possibile esecuzione
di ERCP pre-operatoria con finalità sia
diagnostiche che terapeutiche
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