Syftet med examensarbetet är att studera den subsynkrona interaktionen (subsynchronous torsional interaktion, SSTI) mellan ett HVDC system med spänningsstyva strömriktare och en närliggande generator. Studien utförs med hjälp av datorsimuleringar och fokuserar på att studera dämpkaraktäristiken för SSTI. Studien ska visa hur faktorer såsom den överförda effektens storlek och riktning, vald driftmod och kraftsystemets kortslutningseffekt påverkar dämpkaraktäristiken. Rapporten beskriver subsynkron oscillation (SSO) och tillvägagångssättet vid en SSTI undersökning. En kort introduktion till HVDC Light ges. Studien visar att HVDC Light ökar dämpningen för det frekvensområde som är intressant. Resultaten presenteras som diagram med beräknad dämpkaraktäristik.

Chiropractic training involves many hours of skin contact, and chiropractors have manual contact with millions of patients annually, but chiropractic has only had professional clinical hygiene guidance since 2010. Methicillin-resistant Staphylococcus aureus (MRSA) is the most common cause of cultured skin and soft tissue infection (SSTI) in the United States. Using the epidemiologic triad of person, place, and time as a framework, this quantitative, cross-sectional study obtained the first assessment of MRSA SSTI incidence among chiropractic students and its association with infection control behaviors (hand and table hygiene, sharing gowns, and sharing lotion) and initiation of patient care. The study obtained surveys from 312 students attending half (9/18) of U.S. chiropractic campuses. Associations were assessed by Ï?2 and Fisher's exact test. Stratum specific effects were assessed. Two logistic regression models were produced. The results were that attendance at Campus 6 was associated with postmatriculation MRSA SSTI in univariate analysis, p = 0.010. There was an interaction between campus attended, sharing lotion, and postmatriculation MRSA SSTI, with the Mantel-Haenszel pooled estimate varying significantly from unity, Ï?2 (1) = 6.75, p = 0.009. No other association between any assessed factor and MRSA SSTI was detected. Logistic regression models were significant (p < 0.05), but the composing variables were not. For social change, chiropractic colleges should instruct students and chiropractic associations could encourage members not to share massage lotions and emollients during the practice of manual therapy to help prevent MRSA SSTI.

Methicillin-resistant Staphylococcus aureus (MRSA) is a growing concern in Canada especially in Aboriginal communities in remote regions. The northern and remote communities possess some or many of the risk factors that are identified in previous research to be associated with Community-Associated Methicillin-resistant Staphylococcus aureus (CA-MRSA) infections such as overcrowding, challenges in maintaining personal hygiene and limited access to healthcare. CA-MRSA spreads rapidly in the communities. It is known to not only affect young and healthy individuals, but it is also associated with high morbidity and mortality rates. Furthermore, antibiotic resistance in CA-MRSA is increasing in Canada. It is known that inappropriate and greater use of antibiotics is associated with increased antibiotic resistance. Resistant CA-MRSA infections are more difficult to treat. To reduce and to control the antibiotic resistance, monitoring the prevalence of CA-MRSA and the changing antibiotic susceptibility profiles at the population level, especially in highly affected communities, is crucial. By monitoring this trend, it will enable healthcare practitioners to provide more adequate and appropriate treatment. To our knowledge, there was no community-based study that examined the epidemiology of CA-MRSA skin and soft-tissue infections (SSTIs) in First Nations communities in Canada at large scale, and the knowledge on the risk factors, outcomes and antibiotic susceptibility profiles is still very limited. This study aimed to describe the local epidemiology of SSTIs at the community level in selected First Nations communities as well as to describe the antibiotic use to treat SSTIs and the antibiotic susceptibility patterns of CA-MRSA. A retrospective chart review was conducted in 12 nursing stations in the First Nations communities across 5 provinces in Canada. The charts of individuals over 18 years of age who had received service at the nursing station in the previous 12 months, starting retrospectively from the date of collection, were reviewed in this study. Each antibiotic prescription that was noted in the chart in this period prior to chart review was recorded in the antibiotic tracking case report form. Data collected included demographics, indication for antibiotic use, antibiotic prescription parameters and patient outcomes. In total, of 372 patient charts reviewed, 224 patient charts contained at least one case (an encounter that resulted in an antibiotic prescription during the study period). Of those 224 charts, 459 cases were recorded and, of those, 137 cases had a diagnosis of an SSTI. In the 65 patients accounting for all cases of SSTI patients, more than 80% of the study population were under the age of 50. The prevalence of impaired renal function was low, diabetes was present in 20% of cases, cardiac disease was present in 15% of cases, and reported alcohol misuse was present in 30% of cases. The presence of indwelling devices was very rare. There were 137 cases of SSTIs over 372 charts reviewed in total. The prevalence of SSTI among the selected First Nations communities in 2012-2013 was estimated at almost 37% (137 cases of SSTIs / 372 charts reviewed). In the 137 SSTI cases, 55 cases were identified as MRSA infections either by laboratory test such as wound culture or by history of colonization documented in the chart. The overall prevalence of MRSA in all SSTI cases was estimated at 40.1% (55 confirmed MRSA positive cases / 137 cases of SSTIs). The majority of SSTIs were purulent infections and wounds. We also found that a wound culture and susceptibility test were performed only in 29% of all SSTI cases. An orally administered antibiotic was most frequently used (in 71.5% of treatments). Topical antibiotics were used in 18.3% and IV antibiotics were used in 8.8%. Other than the antibiotic treatment, wound care was performed in 49% of the SSTI cases and incision and drainage (I&D) procedure in 9%. The majority of MRSA isolates in this study were susceptible to clindamycin and co-trimoxazole (90.5% and 95.2%), but only 29% were susceptible to erythromycin. In general, higher rates of SSTIs were seen in communities where overcrowding and poor access to running water are more prevalent. In this study, we found that the diagnostic tests such as wound culture and sensitivity test was not ordered very often and there was also lack of follow-up or lack of documentation of the follow-up. More research is needed to better understand some of the challenges and risk factors associated with CA-MRSA infections in remote communities. Developing a national-level surveillance system that can help with monitoring the epidemiology of SSTIs and the antibiotic susceptibility test results of CA-MRSA at community level would be essential for better prevention, control, and management. Furthermore, adopting other initiatives such as antibiotic stewardship programs at community and healthcare settings as well as addressing the socio-environmental factors such as housing and access to water would be all very important in the steps to curb antibiotic resistance.

The purpose of this thesis was to quantify the prevalence, measure the severity, and describe treatment patterns in patients who present to medical clinics in Texas with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft-tissue infections (SSTI). Ten clinics participated in this prospective, community-based study. Clinicians consented patients and collected clinical information, pictures, and wound swabs; data were processed centrally. MRSASelect[trademark] was used for identification. Susceptibilities were determined via Etest[registered sign]. The results are as follows. Overall, 73/119 (61%) patients had CA-MRSA. Among these, 49% were male, 79% were Hispanic, and 30% had diabetes. Half (56%) of the lesions were [greater than or equal to] 5 cm in diameter. Most patients had abscesses (82%) and many reported pain scores of [greater than or equal to] 7/10 (67%). Many presented with erythema (85%) or drainage (56%). Most received incision and drainage (I&D) plus an antibiotic (64%). Antibiotic monotherapy was frequently prescribed: sulfamethoxazole/ trimethoprim (SMX/TMP) (78%), clindamycin (4%), doxycycline (2%), and mupirocin (2%). The rest frequently received SMX/TMP in combination with other antibiotics. SMX/TMP was commonly administered as one double-strength tablet twice daily. Isolates were 93% susceptible to clindamycin and 100% susceptible to vancomycin, doxycycline, SMX/TMP, and linezolid. We report a predominance of CA-MRSA SSTIs, favorable susceptibilites, and frequent prescribing of SMX/TMP in primary care clinics located in South Texas. / text