An electronic pressure-meter nociception paw test for rats

The objective of the present investigation was to compare the sensitivity of an electronic nociceptive mechanical paw test with classical mechanical tests to quantify the intensity variation of inflammatory nociception. The electronic pressure-meter test consists of inducing the hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared with the classical von Frey filaments test and with the rat paw constant pressure test, a modification of the Randall and Selitto test developed by our group. When comparing the three methods, the electronic pressure-meter and the rat paw constant pressure test, but not the von Frey filaments test, detected time vs treatment interactions in prostaglandin E2 (PGE2)-induced hypernociception. Both methods also detected the PGE2-induced hypernociception in dose- (50-400 ng/paw) and time- (1-4 h) dependent manners, and time vs treatment interactions induced by carrageenin (25-400 µg/paw). Furthermore, the electronic pressure-meter test was more sensitive at early times, whereas the constant pressure test was more sensitive at later times. Moreover, the electronic pressure-meter test detected the dose-dependent antinociceptive effect of local indomethacin (30-300 µg/paw) and dipyrone (80-320 µg/paw) on carrageenin- (200 µg/paw) and PGE2- (100 ng/paw) induced hypernociception, respectively, and also detected the ineffectiveness of indomethacin (300 µg) on the effect of PGE2. Our results show that the electronic pressure-meter provides a sensitive, objective and quantitative mechanical nociceptive test that could be useful to characterize new nociceptive inflammatory mediators and also to evaluate new peripheral analgesic substances.

An electronic pressure-meter nociception paw test for mice

The aim of the present investigation was to describe and validate an electronic mechanical test for quantification of the intensity of inflammatory nociception in mice. The electronic pressure-meter test consists of inducing the animal hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared to the classical von Frey filaments test in which pressure intensity is automatically recorded after the nociceptive hindpaw flexion reflex. The electronic pressure-meter and the von Frey filaments were used to detect time versus treatment interactions of carrageenin-induced hypernociception. In two separate experiments, the electronic pressure-meter was more sensitive than the von Frey filaments for the detection of the increase in nociception (hypernociception) induced by small doses of carrageenin (30 µg). The electronic pressure-meter detected the antinociceptive effect of non-steroidal drugs in a dose-dependent manner. Indomethacin administered intraperitoneally (1.8-15 mg/kg) or intraplantarly (30-300 µg/paw) prevented the hypersensitive effect of carrageenin (100 µg/paw). The electronic pressure-meter also detected the hypernociceptive effect of prostaglandin E2 (PGE2; 10-100 ng) in a dose-dependent manner. The hypernociceptive effect of PGE2 (100 ng) was blocked by dipyrone (160 and 320 µg/paw) but not by intraplantar administration of indomethacin (300 µg/paw). The present results validate the use of the electronic pressure-meter as more sensitive than the von Frey filaments in mice. Furthermore, it is an objective and quantitative nociceptive test for the evaluation of the peripheral antinociceptive effect of anti-inflammatory analgesic drugs, which inhibit prostaglandin synthesis (indomethacin) or directly block the ongoing hypernociception (dipyrone).

Value creation through sponsorship in electronic sports

The objective of this thesis was to study value creation through sponsor-ship in a new emerging electronic sports environment. Sub-questions were formulated which helped in finding answers to the main research question. Theory of traditional sports and practice of electronic sports were compared with each other in order to find out how theories of tradi-tional sports fare in the new environment. B2B-relationship model of Actors, resources and activities is used in this thesis to help in clarifying the different variables used in electronic sports sponsorship environment. The empirical research was conducted via interviews with the managers working in electronic sports environment. One of the main conclusions is that relationship management is really important.. Actors in electronic sports need to find and create win-win-win situations. This means that they need to benefit the actors in sponsoring relationship and also the community.

First-principles study on electronic and structural properties of Cu(In/Ga)Se alloys for solar cells

Thin-film photovoltaic solar cells based on the Cu(In1−xGax)Se2 (CIGS) alloys have attracted more and more attention due to their large optical absorption coefficient, long term stability, low cost, and high efficiency. Modern theoretical studies of this material with first-principles calculations can provide accurate description of the electronic structure and yield results in close agreement with experimental values, but takes a large amount of calculation time. In this work, we use first-principles calculations based on the computationally affordable meta- generalized gradient approximation of the density-functional theory to investigate electronic and structural properties of the CIGS alloys. We report on the simulation of the lattice parameters and band gaps, as a function of chemical composition. The obtained results were found to be in a good agreement with the available experimental data.

Evidence for eosinophil recruitment, leukotriene B4 production and mast cell hyperplasia following Toxocara canis infection in rats

It is well known that eosinophilia is a key pathogenetic component of toxocariasis. The objective of the present study was to determine if there is an association between peritoneal and blood eosinophil influx, mast cell hyperplasia and leukotriene B4 (LTB4) production after Toxocara canis infection. Oral inoculation of 56-day-old Wistar rats (N = 5-7 per group) with 1000 embryonated eggs containing third-stage (L3) T. canis larvae led to a robust accumulation of total leukocytes in blood beginning on day 3 and peaking on day 18, mainly characterized by eosinophils and accompanied by higher serum LTB4 levels. At that time, we also noted increased eosinophil numbers in the peritoneal cavity. In addition, we observed increased peritoneal mast cell number in the peritoneal cavity, which correlated with the time course of eosinophilia during toxocariasis. We also demonstrated that mast cell hyperplasia in the intestines and lungs began soon after the T. canis larvae migrated to these compartments, reaching maximal levels on day 24, which correlated with the complete elimination of the parasite. Therefore, mast cells appear to be involved in peritoneal and blood eosinophil infiltration through an LTB4-dependent mechanism following T. canis infection in rats. Our data also demonstrate a tight association between larval migratory stages and intestinal and pulmonary mast cell hyperplasia in the toxocariasis model.

Dermatan sulfate reduces monocyte chemoattractant protein 1 and TGF-β production, as well as macrophage recruitment and myofibroblast accumulation in mice with unilateral ureteral obstruction

Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS) bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO). Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6) was not subjected to any surgical manipulation; group SH (N = 6) was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6) was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6) was subjected to UUO and received DS (4 mg/kg) subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-β. Collagen (stained area ~3700 µm²), MCP-1 (stained area ~1700 µm²), TGF-β (stained area ~13% of total area), macrophage (number of cells ~40), and myofibroblast (stained area ~1900 µm²) levels were significantly (P < 0.05) higher in the UUO group compared to control. DS treatment significantly (P < 0.05) reduced the content of collagen (stained area ~700 µm²), MCP-1 (stained area ~160 µm²) and TGF-β (stained area ~5% of total area), in addition to myofibroblast (stained area ~190 µm²) and macrophage (number of cells ~32) accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.

The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

It is currently accepted that superoxide anion (O2•−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

Power Electronic Converters in Low-Voltage Direct Current Distribution – Analysis and Implementation

Over the recent years, smart grids have received great public attention. Many proposed functionalities rely on power electronics, which play a key role in the smart grid, together with the communication network. However, “smartness” is not the driver that alone motivates the research towards distribution networks based on power electronics; the network vulnerability to natural hazards has resulted in tightening requirements for the supply security, set both by electricity end-users and authorities. Because of the favorable price development and advancements in the field, direct current (DC) distribution has become an attractive alternative for distribution networks. In this doctoral dissertation, power electronic converters for a low-voltage DC (LVDC) distribution system are investigated. These include the rectifier located at the beginning of the LVDC network and the customer-end inverter (CEI) on the customer premises. Rectifier topologies are introduced, and according to the LVDC system requirements, topologies are chosen for the analysis. Similarly, suitable CEI topologies are addressed and selected for study. Application of power electronics into electricity distribution poses some new challenges. Because the electricity end-user is supplied with the CEI, it is responsible for the end-user voltage quality, but it also has to be able to supply adequate current in all operating conditions, including a short-circuit, to ensure the electrical safety. Supplying short-circuit current with power electronics requires additional measures, and therefore, the short-circuit behavior is described and methods to overcome the high-current supply to the fault are proposed. Power electronic converters also produce common-mode (CM) and radio-frequency (RF) electromagnetic interferences (EMI), which are not present in AC distribution. Hence, their magnitudes are investigated. To enable comprehensive research on the LVDC distribution field, a research site was built into a public low-voltage distribution network. The implementation was a joint task by the LVDC research team of Lappeenranta University of Technology and a power company Suur-Savon S¨ahk¨o Oy. Now, the measurements could be conducted in an actual environment. This is important especially for the EMI studies. The main results of the work concern the short-circuit operation of the CEI and the EMI issues. The applicability of the power electronic converters to electricity distribution is demonstrated, and suggestions for future research are proposed.

The role of motivational systems in community service involvement : initiating and sustaining factors and quality of experience /

Community service participation can have a positive impact on development, especially for youth. Although researchers have found positive outcomes, there has been a notable decline in youth participation over the past few years (Statistics Canada, 2000). Given the positive outcomes and current decline, it has been argued that youth should be encouraged to get involved in service activities. In the present study, quantitative and qualitative data were collected to determine factors that would help youth to initiate and sustain service, along with examining the quality of their experience. Eighty-two university undergraduate students (23 men), ranging in age from 17-20 years completed a 60-minute self-report questionnaire. Initiating and sustaining factors, motivational systems (similar to approach and avoidance dimensions), activity dimensions {Structure, Supportive Social Environment), quality of experience {Positive, Stress-Challenge), and future intention to participate in community service were measured. Eight participants also completed a 20-minute telephone interview to complement and expand on the quantitative data collected. Some initiating and sustaining factors were specific to individuals higher on the avoidance dimension, while others were relevant to those higher on the approach dimension. Several factors also were important to individuals regardless of their motivational system orientation. Positive quality of experience was related positively to experiencing a supportive social environment. In addition, women rated their community service as more positive than did men. A predicted interaction between the avoidance dimension and Structure in predicting positive quality of experience was not supported; however, positive quality of experience was predicted by the interaction of the approach dimension and Structure. A tested interaction between the avoidance dimension and Supportive Social Environment in predicting positive quality of experience was not supported. Similarly, a predicted interaction between the approach dimension and Supportive Social Environment in predicting positive experience quality was not supported. However, Supportive Social Environment was positively related to positive quality of experience. No support was found for a mediational role for positive quality of experience or stress-challenge quality of experience in exploring the relation between motivational orientation and fiiture intention to engage in service activities. The results of this study suggest that participating in a service environment that is supportive and provides the opportunity for social interactions with others would promote positive quality of experience and help youth sustain involvement. Thus, to help youth have positive experiences and to remain active in service, it is important for service agencies to promote these types of environments. In addition, some initiating and sustaining factors were specific to youth higher on the avoidance dimension and some were relevant to youth higher on the approach dimension. Therefore, service agencies may need to consider using different recruitment and retention strategies, depending on the type of youth they wish to recruit.

Comparing ESL electronic and face-to-face pre-writing conferences and first drafts : discourse, participation, and idea transfer /

This study was a comparative investigation of face-toface (i.e., proximate) and computer-mediated written (i.e., graphic) pre-writing conferences. The participants in this study were advanced English as a second language students. The 2 types of conferences were compared in terms of textual features, participation, and the . degree to which they were on topic. Moreover, drafts written after the 2 types of conferences were compared in terms of textual features, and the degree to which they were related to the conferences. Students produced an equivalent amount of discourse in an equivalent amount of time in the 2 types of conferences. The discourse in graphic conferences displayed greater lexical range, and some evidence suggests that it was less on-topic. Both these results likely occurred because the graphic conferences contained more discourse demonstrating interactive competence. Participation in graphic conferences was found to be as balanced or more balanced among students, and among students and the group leader combined. Overall, the drafts produced after the 2 types of conferences were of equivalent length and topical range, but some evidence suggests that drafts written after proximate conferences were more related to the conferences.