On theoretical modeling of transformer cooling

A theoretical model of the electrohydrodynamic prebreakdown phenomena in the weakly ionized media is proposed. Differential equations and initial conditions for describing the heat transfer in transformers are written. The Nusselt number’s dependence on the high voltage is obtained.     

Subjective, psychomotor, cognitive, and analgesic effects of subanesthetic concentrations of sevoflurane and nitrous oxide

BACKGROUND: Sevoflurane is a volatile general anesthetic that differs in chemical nature from the gaseous anesthetic nitrous oxide. In a controlled laboratory setting, the authors characterized the subjective, psychomotor, and analgesic effects of sevoflurane and nitrous oxide at two equal minimum alveolar subanesthetic concentrations. METHODS: A crossover design was used to test the effects of two end-tidal concentrations of sevoflurane (0.3% and 0.60%), two end-tidal concentrations of nitrous oxide (15% and 30%) that were equal in minimum alveolar concentration to that of sevoflurane, and placebo (100% oxygen) in 12 healthy volunteers. The volunteers inhaled one of these concentrations of sevoflurane, nitrous oxide, or placebo for 35 min. Dependent measures included subjective, psychomotor, and physiologic effects, and pain ratings measured during a cold-water test. RESULTS: Sevoflurane produced a greater degree of amnesia, psychomotor impairment, and drowsiness than did equal minimum alveolar concentrations of nitrous oxide. Recovery from sevoflurane and nitrous oxide effects was rapid. Nitrous oxide but not sevoflurane had analgesic effects. CONCLUSIONS: Sevoflurane and nitrous oxide produced different profiles of subjective, behavioral, and cognitive effects, with sevoflurane, in general, producing an overall greater magnitude of effect. The differences in effects between sevoflurane and nitrous oxide are consistent with the differences in their chemical nature and putative mechanisms of action.     

And now what, after such tribulations? Memory and dislocation in the era of uprooting.

This article explores some of the often overlooked, traumatic psychological consequences that follow from major social and political disruption and upheaval. Specifically, it examines the importance of maintaining memory and legacy in the face of widespread uprootedness and dislocation of the sort that can undermine and even obliterate personal, social, and collective identities. The role that authentic social frameworks for memory play in preserving psychological rootedness and that accurate historical narratives play in resistance and regrouping is explored. Finally, the importance of creating a new psychology that is fully grounded in history and culture is emphasized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Histologic appearance of transmyocardial laser channels after 4 1/2 weeks

Preliminary results of clinical studies suggest that transmyocardial laser revascularization is an effective treatment for patients with chronic angina that cannot be treated by other means. The mechanism of this effect remains controversial. We present autopsy results from a patient obtained 4 1/2 weeks after operation that show that the channels do not maintain patency. Further work is needed to determine the frequency of channel patency and its relation to clinical benefit.     

Thoracoscopic microsurgical excision of a thoracic schwannoma. Case report

A 6-cm-diameter schwannoma located at T-2 was resected completely by using transthoracic microsurgical endoscopy. The partially cystic tumor widened the neural foramen and extended into the apex of the right thoracic cavity but did not extend intradurally. The tumor was accessed by means of three 15-mm incisions made in the intercostal spaces. The operative blood loss was only 200 ml, and there were no complications. The patient was discharged on the 2nd postoperative day and returned to full activity 1 week after surgery. Thoracoscopy provides an excellent alternative to thoracotomy for peripheral thoracic nerve sheath tumors that originate within the neural foramen or more distally along the intercostal nerves within the thorax. An anterior approach is required for intrathoracic tumors but is not suited for intradural tumors. An open posterior or posterolateral approach to the thoracic spine is required for intradural tumors to allow the dura to be closed adequately.     

Survey of o-phenylphenol residues found in marketable citrus fruit

Residues of o-phenylphenol (OPP) were determined in peel, pulp and the whole fruit of Shamouti and Valencia oranges, grapefruits and lemons which were treated under industrial conditions with solutions of sodium-o-phenylphenate (SOPP). The OPP residues found in the peel of the different species of citrus fruit varied from 5.4 to 26.1 ppm OPP. In many cases OPP residues were not detectable in the pulp, and in other cases traces and 0.4 ppm of OPP were found. The residues in the whole fruit were found to range from 1.8 to 8.3 ppm, with 80% of the samples analysed containing less than 5 ppm. These amounts were within the tolerance limits generally established for residues of OPP in citrus fruit (10 and 12 ppm of OPP). The SOPP concentration of the disinfectant solutions ranged from 0.24 to 0.55% SOPP.4H₂O and had little effect on the OPP content of the fruits. The fruits which were treated at a pH below 11.6 usually contained more OPP than those treated at pH values between 11.6 and 12.3.     

Deflation of detachable balloons in the cavernous sinus by percutaneous puncture

The authors show that percutaneous puncture of balloons within the cavernous sinus is technically feasible and allows further access to the cavernous sinus after balloon detachment. Complete closure of a large carotid cavernous fistula was achieved in the 37-year-old trauma victim they treated using this technique.     

Learning (not) to talk about race: When older children underperform in social categorization.

The present research identifies an anomaly in sociocognitive development, whereby younger children (8 and 9 years) outperform their older counterparts (10 and 11 years) in a basic categorization task in which the acknowledgment of racial difference facilitates performance. Though older children exhibit superior performance on a race-neutral version of the task, their tendency to avoid acknowledging race hinders objective success when race is a relevant category. That these findings emerge in late childhood, in a pattern counter to the normal developmental trajectory of increased cognitive expertise in categorization, suggests that this anomaly indicates the onset of a critical transition in human social development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of a cold-water stressor on psychomotor and cognitive functioning in humans

The effects of an acute stressful and painful stimulus, cold water, on psychomotor and cognitive functioning, was assessed in 14 healthy volunteers. Subjects immersed their forearm in ice-cold water (2-3 degrees C) and luke-warm water (37 degrees C) for 3 min, and during this time period a psychomotor or cognitive test was performed. These immersions were done over the course of two experimental sessions, spaced at least 2 days apart, with six trials in each session. Within each session, cold and warm water immersions alternated. Results indicated that flicker-from-fusion threshold from the critical flicker frequency test was higher in the cold-water condition than in the luke-warm-water condition, indicative of increased alertness from the cold stimulus. Short-term memory was attenuated, however, in the cold-water condition. Performance on other tests including those that required speed and/or concentration were not affected by the manipulation. Subjects rated the cold-water stimulus as painful and bothersome, and their blood pressure was significantly elevated by the stimulus. We conclude that a painful stimulus may affect psychomotor and/or cognitive functioning, but the relationship is somewhat complex and depends on the particular tests used.