1,721,026 research outputs found
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
Influence of duration of simulated transport on plasma stress markers in the calf
No full textThe effects of simulated transport of calves for 150 min on plasma cortisol, NEFA, glucose, and calcium were evaluated. Both cortisol and NEFA reached maximal values within 30-60 min, with no further increases during the transportation. Changes in glucose and calcium were not significant. The results indicate that in simulated transport, the duration per se is not a crucial factor in transport stress
Haematological parameters and altered erythrocyte metabolism in anaemic dogs
No full textIn previous studies, an increase in the activity of pyruvate kinase (PK) and glucose-6-phosphate dehydrogenase (G6PDH), an increase in the concentration of 2,3-diphosphoglycerate (2,3DPG), and alterations in osmotic fragility were found in dogs with haemolytic anaemia. These changes were mainly caused by the presence of immature red cells found in regenerative anaemias. In the present study, the same parameters were evaluated in dogs with different types of anaemia. The haematological patterns of 40 anaemic dogs were analysed to define the pathogenesis and the haematological features of each case. Non-regenerative anaemias could be attributed principally to chronic diseases and to the haemolysis that accompanies the early stages of canine babesiosis. Regenerative anaemias were mainly due to haemolysis, in some cases with an immune-mediated pathogenesis. PK activity was higher in regenerative than in non-regenerative anaemias, but G6PDH activity and 2,3DPG concentration increased in both types of anaemia. This suggests that PK activity is influenced by the presence of immature red cells, but the requirements for reducing compounds and oxygen are not dependent on the type of anaemia. Abnormalities in osmotic fragility were detected in haemolytic anaemias and in those non-regenerative anaemias in which reticulocyte percentage, but not reticulocyte production index (RPI), increased. The osmotic fragility could be used as an early indicator of erythrocyte regeneration. (C) 2000 Harcourt Publishers Ltd
In vitro influence of two concentrations of ketone bodies on different steps of phagocytosis of ovine neutrophils
No full textIN VITRO INFLUENCE OF TWO CONCENTRATIONS OF KETONE BODIES ON DIFFERENT STEPS OF PHAGOCYTOSIS OF OVINE NEUTROPHILS
Sartorelli P., Paltrinieri S., Agnes F.
Istituto di Patologia Generale Veterinaria, Milano
In previous works (1, 2) we have found that sheep neutrophil functions were affected differently when high concentrations of acetoacetate (4.8 mmol/l), -OH-butyrate (4.8 mmol/l), or acetoacetate (4.8 mmol/l) and -OH-butyrate (4.8 mmol/l) together were present. Because acetoacetate is a lithium salt, we also verified the effects of LiCl (4.8 mmol/l): in particular chemotaxis was depressed when both the ketone bodies were added simultaneously, while the uptake of latex particles was depressed only with -OH-butyrate, maybe due to the activating effect of LiCl.
To verify the efficency of non-specific immunity in subketotic conditions, when infectious diseases are frequently detectable, we repeated these tests in the presence of lower concentrations of the ketone bodies (2.4 mmol/l). Furthermore, to complete the evaluation of the phagocytic process we studied the adherence and the respiratory burst of ovine neutrophils either at 4.8 mmol/l or at 2.4 mmol/l of the ketone bodies.
Neutrophils were isolated from the blood of 8 sheep by centrifugation followed by two hypotonic lysis of erythrocytes; chemotaxis was measured in a modified Boyden chamber using the leading front method; phagocytosis was measured using polystyrene latex particles, with spectrophotometric evaluation after dioxan solubilization; adherence was measured in microtiter plate, along with the respiratory burst by means of superoxide production evaluation.
Adherence and superoxide production were not affected by the ketone bodies or LiCl at the different concentrations employed.
Even if a trend to depression of chemotaxis was detectable when the two ketone bodies were added simultaneously, no significative differences were found, due to strong individual variations.
No variation in latex partcicle uptake ability was detectable using 2.4 mmol/l ketone bodies.
In conclusion, while with high concentrations of ketone bodies some steps of the phagocytic process were undoubtably affected, the influence of lower concentration of ketone bodies, similar to those detectable in subketotic conditions, is much more variable among animals. This could suggest that non specific immunity is less involved in the immunodepressive status that characterize the subketotic condition, than other factors, such as specific immunity depression.
(1) Paltrinieri S. et al., (1995), European Journal of Veterinary Pathology, 2 (Suppl): 48
(2) Paltrinieri S. et al., (1996), European Journal of Haematology, 57 (Suppl. 59):1
Non specific immunity and ketone bodies. 1: In Vitro studies on chemotaxis and phagocytosis in ovine neutrophils
No full textThe in vitro effects of the ketone bodies β-OH-butyrate (2.4 or 4.8 mmol/1) and acetoacetate (2.4 or 4.8 mmol/1) on the uptake of latex particles (1.09 μm) and chemotaxis were investigated in ovine neutrophils. Because the acetoacetate used was a lithium salt, the effect of 2.4 or 4.8 mmol/1 lithium chloride was also tested. Neutrophils from eight non-lactating, non-pregnant ewes were studied. The uptake of latex particles, as measured by a spectrophotometric method, showed wide individual variation. The phagocytotic activity was unaffected by 2.4 mmol/1 ketone bodies and LiCl, but it was significantly inhibited by 4.8 mmol/1 β-OH-butyrate and activated by 4.8 mmol/1 LiCl. The latter result could be masking an inhibitory effect of acetoacetate. Chemotactic movements of neutrophils, as evaluated in a modified Boyden chamber using homologous zymosan-activated serum (ZAS) as a chemoattractant, were slightly but significantly reduced by a 2.4 mmolar concentration of the ketone bodies, administered singly or simultaneously, and by LiCl. We conclude therefore that the inhibitory effect of lithium-acetoacetate could be due to its lithium component. The 4.8 mmol/1 dose of acetoacetate and β-OH butyrate significantly decreased chemotaxis only when both compounds were added simultaneously. No effect of 4.8 mmol/1 LiCl was observed. These results suggest that ketone bodies, in particular β-OH butyrate, could directly influence particle uptake and chemotaxis in neutrophils. Although other factors could decrease the efficiency of the immune system in ketotic ruminants, the effects of the ketone bodies on neutrophils functions may explain the high frequency of infectious disease during 'ketotic syndrome'. The immunomodulatory effect of lithium needs to be evaluated further and it should be considered when testing lithium compounds
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