1,721,045 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
Pulmonary gas exchange in anesthetized horses mechanically ventilated with oxygen or a helium/oxygen mixture
No full textIt is unknown whether administration of gas-mixtures high in inspired fraction of oxygen (FiO2) under general anaesthesia may increase formation of pulmonary atelectasis and impair gas exchange.
OBJECTIVE:
To evaluate the effects of different FiO2 on pulmonary gas exchange in isoflurane-anaesthetised horses breathing a helium/oxygen (He/O2) mixture.
METHODS:
Thirty healthy mature horses were sedated with i.v. acepromazine (0.02 mg/kg bwt), detomidine (0.002 mg/kg bwt) and xylazine (02-0.4 mg/kg bwt). General anaesthesia was induced with i.v. 5% guaifenesin to effect, diazepam (0.1 mg/kg bwt) and ketamine (2 mg/kg bwt), and maintained with isoflurane. Fifteen horses (Group HX) were ventilated mechanically with gas mixtures of successively increasing FiO2 (0.25-030, 0.50-0.55, > 0.90), obtained by blending 02 with Heliox (70% He/30% O2). The other 15 horses (Group O) were ventilated immediately with 100% O2 (FiO2 > 0.90). After 20 min of ventilation at the different FiO2 levels in Group HX and after 60 min in Group O, PaO2 and PaCO2 were measured and the alveolar to arterial PO2 gradient (P(A-a)O2) was calculated. Data analysis included robust categorical regression with clustering on horse (P < 0.05).
RESULTS:
Inhalation of a He/O2 mixture with FiO2 as low as 0.25-030 ensured adequate arterial oxygenation and was associated with a smaller P(A-a)O2 gradient than inhalation of pure O2 (P 0.90 (P < 0.05).
CONCLUSIONS AND POTENTIAL RELEVANCE:
Administration of a He/O2 gas mixture low in FiO2 can better preserve lung function than ventilation with pure oxygen. A step-wise increase of FiO2 using a He/O2 gas mixture might offer advantages with respect to pulmonary gas exchange over an immediate exposure to 100% 2O2
Effects of inspired oxygen concentration on pulmonary gas exchange in anesthetized horses mechanically ventilated with a helium/oxygen (He/O2) gas mixture
No full textThe isoflurane sparing effect of intravenous lidocaine administered to horses undergoing exploratory celiotomy
No full textA comparison of subarachnoid buprenorphine or xylazine as an adjunct to lidocaine for analgesia in goats
No full textObjective To test the hypothesis that subarachnoid administration of buprenorphine and lidocaine provides more intense and longer lasting perioperative analgesia with less side effects than xylazine and lidocaine in goats. Study design Randomized, blinded, controlled study. Study animals Ten healthy female goats randomly assigned to two groups of five animals each. Methods After sedation with acepromazine (0.1 mg kg-1) intravenously (IV), lidocaine 2% (0.1 mL kg-1) combined with either xylazine (0.05 mg kg-1; Group X) or buprenorphine (0.005 mg kg-1; Group B) were injected intrathecally at the lumbo-sacral junction prior to stifle surgery. Electrocardiogram, heart rate, direct systolic, mean, and diastolic arterial blood pressures, rectal temperature and arterial blood gases were recorded as were post-operative sedation and pain scores using a visual analogue and numeric rating scale, respectively. Data were analyzed with one-way anova for repeated measures, one-way anova, Friedman's and Kruskal-Wallis tests as necessary (p < 0.05). Results Surgery was successfully performed under both analgesia protocols. Total pain and sedation scores were significantly lower in the B as compared with X group from 3-24 hours and 30-120 minutes, respectively after subarachnoid drug administration (SDA). Heart rate and arterial blood pressures decreased post SDA and were consistently lower in X versus B (p < 0.05). In B arterial blood gas parameters did not change post SDA, but in group X PaCO2 increased slightly within 15 minutes of SDA and remained elevated for at least 3 hours (p < 0.05). Conclusion In these goats intrathecal administration of buprenorphine and lidocaine produced more profound and longer lasting analgesia with less sedation and hemodynamic and respiratory impairment than xylazine with lidocaine. Clinical relevance In these goats undergoing hind limb surgery, subarachnoid buprenorphine/lidocaine offered more intense and longer lasting analgesia than a xylazine/lidocaine combination, with less sedation and impairment of cardiopulmonary functio
Sensory nerve conduction and nociception in the equine lower forelimb during perineural bupivacaine infusion along the palmar nerves
No full textThe purpose of this investigation was to study lateral palmar nerve (LPN) and medial palmar nerve (MPN) morphology and
determine nociception and sensory nerve conduction velocity (SNCV) following placement of continuous peripheral nerve block
(CPNB) catheters along LPN and MPN with subsequent bupivacaine (BUP) infusion. Myelinated nerve fiber distribution in
LPN and MPN was examined after harvesting nerve specimens in 3 anesthetized horses and processing them for morphometric
analysis. In 5 sedated horses, CPNB catheters were placed along each PN in both forelimbs. Horses then received in one forelimb
3 mL 0.125% BUP containing epinephrine 1:200 000 and 0.04% NaHCO3 per catheter site followed by 2 mL/h infusion over a 6-day
period, while in the other forelimb equal amounts of saline (SAL) solution were administered. The hoof withdrawal response
(HWR) threshold during pressure loading of the area above the dorsal coronary band was determined daily in both forelimbs.
On day 6 SNCV was measured under general anesthesia of horses in each limb’s LPN and MPN to detect nerve injury, followed by CPNB catheter removal. The SNCV was also recorded in 2 anesthetized non-instrumented horses (sham controls). In both
LPN and MPN myelinated fiber distributions were bimodal. The fraction of large fibers (. 7 mm) was greater in the MPN than
LPN (P , 0.05). Presence of CPNB catheters and SAL administration did neither affect measured HWR thresholds nor SNCVs,
whereas BUP infusion suppressed HWRs. In conclusion, CPNB with 0.125% BUP provides pronounced analgesia by inhibiting sensory nerve conduction in the distal equine forelimb
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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