1,721,029 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
On the cellular mechanisms underlying working memory capacity in humans
The cellular processes underlying individual differences in the Working Memory Capacity (WMC) of humans are essentially unknown. Psychological experiments suggest that subjects with lower working memory capacity (LWMC), with respect to subjects with higher capacity (HWMC), take more time to recall items from a list because they search through a larger set of items and are much more susceptible to interference during retrieval. However, a more precise link between psychological experiments and cellular properties is lacking and very difficult to investigate experimentally. In this paper, we investigate the possible underlying mechanisms at the single neuron level by using a computational model of hippocampal CA1 pyramidal neurons, which have been suggested to be deeply involved in the recognition of specific items. The model makes a few experimentally testable predictions on the cellular processes underlying the cumulative latency in delayed free recall experimentally observed in humans under different testing conditions. The results suggest, for the first time, a physiologically plausible explanation for individual performances, and establish a proof of principle for the hypothesis that HWMC individuals use a larger portion of the apical tree with a correlated higher level of synaptic background noise
Spleen rupture: an unusual postoperative complication after laparoscopic cholecystectomy.
Abstract
INTRODUCTION:
Laparoscopic cholecystectomy is the gold standard in the surgical treatment of symptomatic cholelithiasis and other benign gallbladder diseases. Laparoscopic cholecystectomy isn't devoid by some complications such as intra and post-operative bleeding, biliary injury, bile leakage, surgical site infection, port-site hernia and visceral injury. After an extensive literature research, we find only one case study in which the patients required a splenectomy after laparoscopic cholecystectomy. We present a case of uneventful laparoscopic cholecystectomy requiring an open splenectomy during the postoperative course.
CASE REPORT:
The Authors report a case of ruptured spleen during the second post-operative day after an uncomplicated laparoscopic cholecystectomy. At 36 hours after the operation, the patient referred a sudden upper abdominal pain. We performed a splenectomy, intra-abdominal lavage and two drainages have been placed. The patient was discarged in the 7th post-operative day in good clinical condition.
CONCLUSION:
As best of our Knowledge we report the second case of spleen rupture after a cholecystectomy, which is reported in the literature. We think that the splenic injury should not be due to direct trauma after or at the time of cholecystectomy, but it should be due to some adherences stretched by the pneumoperitoneum induction. KEY WORDS: Complication,Laparoscopic cholecystectomy, Laparoscopy Spleen rupture
Variations on the Author
“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
Il volgarizzamento trecentesco del Libro delle factezze della spera e di sue figure e di sue opere (ms. Bav, Vat. Lat. 8174)
Il contributo offre la prima edizione critica del volgarizzamento fiorentino del Libro
delle factezze della spera e di sue figure e di sue opere, eseguito nel 1341 e tràdito dal manoscritto
BAV, Vat. Lat. 8174, pp. 103a-130b. L’edizione è accompagnata da un ampio studio introduttivo,
da un Glossario dei principali termini tecnici e da un Indice delle voci in castigliano
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Appropriate Similarity Measures for Author Cocitation Analysis
We 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
On the structural connectivity of large-scale models of brain networks at cellular level
The brain’s structural connectivity plays a fundamental role in determining how neuron networks generate, process, and transfer information within and between brain regions. The underlying mechanisms are extremely difficult to study experimentally and, in many cases, large-scale model networks are of great help. However, the implementation of these models relies on experimental findings that are often sparse and limited. Their predicting power ultimately depends on how closely a model’s connectivity represents the real system. Here we argue that the data-driven probabilistic rules, widely used to build neuronal network models, may not be appropriate to represent the dynamics of the corresponding biological system. To solve this problem, we propose to use a new mathematical framework able to use sparse and limited experimental data to quantitatively reproduce the structural connectivity of biological brain networks at cellular level
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