1,721,132 research outputs found
Case report: Successful endoscopic removal of a large rectal foreign body
No full textIncidence of emergency access due to retained large rectal foreign bodies is increased in the last years. Such situations are a challenge because often, due to their size and physical characteristics, the large foreign bodies of the rectum cannot be extracted manually or by endoscopy, thus requiring surgery, as reported in the literature. We report a case of a 59-old male with a retention of a large vegetable rectal foreign body (whole eggplant) successfully subjected to endoscopic removal without the need for surgery
An automatic procedure for using models of proteins in molecular replacement.
No full textIn a crystallography experiment, a crystal is irradiated with X-rays whose diffracted waves are collected and measured. The reconstruction of the structure of the molecule in the crystal requires knowledge of the phase of the diffracted waves, information that is lost in the passage from the three-dimensional structure of the molecule to its diffraction pattern. It can be recovered using experimental methods such as heavy-atom isomorphous replacement and anomalous scattering or by molecular replacement, which relies on the availability of an atomic model of the target structure. This can be the structure of the target protein itself, if a previous structure determination is available, or a computational model or, in some cases, the structure of a homologous protein. It is not straightforward to predict beforehand whether or not a computational model will work in a molecular replacement experiment, although some rules of thumb exist. The consensus is that even minor differences in the quality of the model, which are rather difficult to estimate a priori, can have a significant effect on the outcome of the procedure. We describe here a method for quickly assessing whether a protein structure can be solved by molecular replacement. The procedure consists in submitting the sequence of the target protein to a selected list of freely available structure prediction servers, cluster the resulting models, select the representative structures of each cluster and use them as search models in an automatic phasing procedure. We tested the procedure using the structure factors of newly released proteins of known structure downloaded from the Protein Data Bank as soon as they were made available. Using our automatic procedure we were able to obtain an interpretable electron density map in more than half the cases
Competitive equilibrium cycles with endogenous labor
No full textIn this paper, we study a two-sector optimal growth model with elastic labor supply. We show that the modified golden rule is saddle-point stable when the investment good is capital intensive. To characterize stability with a capital intensive consumption good, we focus on either additively separable or homothetic preferences. In the first specification, we show that optimal oscillations require the elasticity of intertemporal substitution in consumption to be high enough while the elasticity of labor needs to be low enough. At the same time, we prove that with a linear utility in leisure the modified golden rule is always saddle-point stable. In the second specification for preferences, we show that the local dynamic properties of the optimal path depend instead on the shares of consumption and leisure into total utility. We prove that endogenous fluctuations are even more likely with homothetic preferences
Animal spirits in cash-in-advance economies
No full textThe possibility of indeterminacy and sunspot fluctuations in dynamic rational expectations models has been often questioned on empirical grounds, for such models are widely believed to rely on implausibly high degrees of increasing returns to scale and/or other controversial calibrations of economic fundamentals. In this paper, we study the occurrence of such phenomena in a standard (one-sector) optimal growth model with endogenous labor supply and a partial cash-in-ad vanee constraint on consumption purchases. We show that, under standard preferences and constant returns to scale in production, indeterminacy typically prevails for an arbitrarily small amplitude of the liquidity constraint. We also analyze the cyclical properties of the model submitted to technological and beliefs disturbances and observe that it performs as well as comparable indeterminate models in the literature
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
Plausibility of Indeterminacy and Complex Dynamics
No full textWe study a pure exchange economy with infinite-lived agents, in which a share of consumption purchases must be paid cash. The economy may exhibit multiple equilibria, no matter what the fundamental specification, the only requirement being a share of consumption to be paid cash sufficiently low. Complex dynamics, such as chaos and cycles of eny periodicity, can emerge under gross substitutability, a condition usually known for eliminating such phenomena
- …
