Fractal Reconnection in Solar and Stellar Environments

Recent space based observations of the Sun revealed that magnetic reconnection is ubiquitous in the solar atmosphere, ranging from small scale reconnection (observed as nanoflares) to large scale one (observed as long duration flares or giant arcades). Often the magnetic reconnection events are associated with mass ejections or jets, which seem to be closely related to multiple plasmoid ejections from fractal current sheet. The bursty radio and hard X-ray emissions from flares also suggest the fractal reconnection and associated particle acceleration. We shall discuss recent observations and theories related to the plasmoid-induced-reconnection and the fractal reconnection in solar flares, and their implication to reconnection physics and particle acceleration. Recent findings of many superflares on solar type stars that has extended the applicability of the fractal reconnection model of solar flares to much a wider parameter space suitable for stellar flares are also discussed.Comment: Invited chapter to appear in "Magnetic Reconnection: Concepts and Applications", Springer-Verlag, W. D. Gonzalez and E. N. Parker, eds. (2016), 33 pages, 18 figure

Report of the RCDSO/CDHRSU Workshop on Developing Clinical Guidelines/Standards of Practice

Under the auspices of Quality Assurance Committee of The Royal College of Dental Surgeons of Ontario (RCDSO) investigators from the Community Dental Health Services Research Unit (CDHSRU) held a workshop to test a model for developing clinical guidelines/standards of practice as required under the Regulated Health Professions Legislation. Forty two dentists and representatives of the public and professions from Ontario and Canada participated in a workshop held over three days. The participants were to learn, through direct experience, each of the steps as defined by the literature on clinical guideline development. Ultimately they were to recommend the steps for the RCDSO to follow in developing standards of practice

The update of evidence-based recommendation for the use of pit and fissure sealants in the North York Public Dental Program: An evidence-based report

Program guidelines have been developed to assist clinicians in making decisions on the management ofpatient care. The guidelines and the underlying evidence-based report, also assist managers to allocate resources to achieve maximum impact and to assure the quality of patient care. These guidelines assist staff in decision-making for quality care. They also assist the managers in their decisions on allocation of resources to best fit the needs and to maximize the impact of the services provided

Success of Endodontic therapy on permanent molars and recommendations for endodontic therapy in the North York Public Health Department

The frequency of endodontic therapy of permanent teeth has increased substantially in the past 30-40 years, with an increasing proportion of this treatment occurring on the molars and pre-molars rather than anterior teeth (Ingle et al. 1985, Farrell & Burke 1989). Performing endodontic treatment on posterior teeth may be more difficult than anterior teeth due to the location of the teeth and their root morphology (Altonen & Mattila 1976, Persson 1982, Ioannides & Bortslap 1983, Friedman et al. 1991, Cheung & Lam 1993). Before considering endodontic therapy, the patient and the practitioner should have an idea of the overall probability of success, but studies investigating the success of endodontic treatment of posterior teeth report varying results. Ingle et al. (1985) suggested that treated teeth, if properly restored, will be retained as long as vital teeth. The North York Public Health Department operates a school-based publicly funded dental program that offers basic dental care to children in need. Because the dental program's resources are limited, treatment, prevention, and education are provided based on need which is identified through a screening examination. Using this needs-based approach, North York hopes to allocate its fixed resources most appropriately, achieving the highest level of oral health possible for the greatest number of children. One of the treatment services currently offered is endodontic therapy. However, in order to assess which services are most likely to achieve North York's oral health goals, the expected prognosis of the services they offer should be known. Therefore, we have reviewed the literature to assess the expected rates of success for endodontic therapy of children's permanent posterior teeth.The Community Dental Health Services Research Unit (CDHSRU) is a joint project of the Faculty of Dentistry, University of Toronto and the Dental Division, North York Public Health Department. It is supported by a grant from the Ontario Ministry of Health (#04170)

The management of root caries: an evidence based report

Root caries is a disease of humans, which manifests as lesions on the root surfaces of teeth producing loss of the natural tooth structure. The lesions progress to deeper and deeper levels of the root as well as spreading laterally to enwrap it. Ultimately a lesion can progress to involve the pulp, threatening the viability of the tooth, producing pain and eventual tooth loss. When located between the teeth, the lesions are difficult to access and therefore difficult to excise and restore. In otherwise healthy, North American populations, root caries lesions increase with age. This report sets out to provide evidence-based guidelines on the management (diagnosis, prediction, prevention, and treatment) of root caries for Toronto Public Health staff based on the best available evidence.The preparation of this report was funded by the Community Dental Health Services Research Unit, Faculty of Dentistry, University of Toronto, which receives its funding from the Ministry of Health and Long Term Care Grant #04170

Oral health status of third grade children in North York: clinical and parent-reported measures

We investigated the oral health status of 424, eight and nine year-old, North York children using the results of a clinical examination and a parent interview. Examination results revealed that 35% of the children were free of any evidence of dental caries, 71 % had no or mild malocclusion, 68% were free of dental fluorosis, and 71 % had no periodontal problems. The majority of the untreated dental decay (65%) was found in a minority of the children (10%). The results are consistent with results of the Ontario Children's Dental Health Survey and are comparable to other areas of North America, as well as other parts of the world. Subjective measures of the children's oral health, as reported by their parents, suggest that the oral health of these children was satisfactory. When subjective and clinical measures of oral health were compared we found that children with dental decay were more likely to have experienced tooth pain over the past four weeks. We also found that parents were less likely to be satisfied with the appearance of their child's teeth if their child had moderate to severe fluorosis or any signs of malocclusion.The Community Dental Health Services Research Unit (CDHSRU) is a joint project of the Faculty of Dentistry, University of Toronto and the Dental Division, North York Public Health Department. It is supported by a grant from the Ontario Ministry of Health (#04170)

Dentists' opinions of quality assurance

For a quality assurance (QA) program, includmg practice guidelines, to be m::,st successful, its developrrent and implerrentation should involve all individuals affected by the program. In health care however, QA has typically been carried out by hospital administrators and managers of public health programs and little is known about how health care providers view QA. The Connnunity Dental Services Division of the City of North York Public Health Departrrent (NYPHD) has had a QA program in place for 15 years, but little is known about how dentists, who are currently or might be affected by such a program, view QA. We sent a QA questionnaire to all 771 dentists who were either employed by the North York Public Health Departrrent (NYPHD), or who had treated children under the CINOT Program and have had their claims administered by the NYPHD. Based on the results of the 282 questionnaires that were returned it is evident that the dentists view QA as sorrething positive for the profession. However, the respondents also felt that a QA program should be developed and managed by practicing dentists, and that the public, governrrent, and academic should have limited involverrent. Cost also was not considered to be an important factor in QA. Understandmg these views could guide the developrrent and implerrentation of QA in dentistry.The Community Dental Health Services Research Unit (CDHSRU) is a joint project of the Faculty of Dentistry, University of Toronto and the Dental Division, North York Public Health Department. It is supported by a grant from the Ontario Ministry of Health (#04170)

The impact of policy change in dental health care: an examination of the effect of implementing screening to gain access to dentists' examinations and preventive care in the North York Public Health Department (Pilot Study Findings)

The North York Public Health Department (NYPHD) has operated a schoolbased dental treatment program since 1939. The children receive dental care at no charge and until 1992, enrolment was offered to all children up to and including those attending grade 6. In 1991-92, about one-half of parents chose to have their children attend private dentists. Presumably these parents preferred private dental care and had access to dental insurance or other financial resources to pay for it. In early 1992, North York public health officials believed that all 65,000 school-aged children in the city had access to a full range of diagnostic, preventive and treatment services through the combined coverage by the NYPHD dental programs and the community's private dental practitioners (PDP). In June 1992, the NYPHD received notice from the Ontario Ministry ofHealth that subsidy for the school-based treatment program would be withdrawn immediately. Over the summer and early fall the dental care program managers in the NYPHD received approval from the Board of Health for a revised program fully funded by the municipality. As a result, in 1992-93 and for the foreseeable future,the NYPHD dental program activities consist of: 1) screening children attending school in North York from Junior Kindergarten to Grade 8 (1992-93 estimate 60,000 children) and notification of findings to parents/guardians; 2) offering NYPHD services children with identified need for clinical preventive (1992-93 estimate: 7,000 children) and treatment (1992-93 estimate: 11,000 children) services; 3) providing appropriate services to identified children whose parents enrol them in the NYPHD program (1992-93 estimate: 2,000 children for prevention plus 8,000 for diagnosis and treatment) Thus, those children who have no dental needs identified on screening, will not be offered diagnostic treatment or preventive services by the NYPHD. Approximately 20,000 of these children would have been NYPHD patients in 1991-92 and the question arises as to whether they will suffer adverse health outcomes as a result of the policy change.The Community Dental Health Services Research Unit (CDHSRU) is a joint project of the Faculty of Dentistry, University of Toronto and the Dental Division, North York Public Health Department. It is supported by a grant from the Ontario Ministry of Health (#04170)

Knowledge and practice patterns of Ontario dentists relative to the North York Public Health Department's Dental Practice guidelines

Many studies have shown a high degree of variability in dentists' decision making and have shown that some practices are not supported by the scientific literature. Practice guidelines based on scientific evidence are intended to reduce this variation and indicate which procedures and practice patterns are most appropriate. The North York Public Health Department's Community Dental Services Division provides dental services to children according to evidence based practice guidelines. The purpose of this report was to compare the evidence used to draft these guidelines with the results of the Ontario Dentists' Survey which investigated dental knowledge and practice patterns of Ontario dentists. Results of this comparison revealed that infection control practices of Ontario dentists generally were consistent with the literature, but preventive and radiographic practices were not consistent with current scientific evidence. Simple statistical analyses revealed that these inconsistencies may be related to the dentist's past and present dental education as well as the dentist's practice characteristics. However, further investigation using multivariate analyses is recommended.The Community Dental Health Services Research Unit (CDHSRU) is a joint project of the Faculty of Dentistry, University of Toronto and the Dental Division, North York Public Health Department. It is supported by a grant from the Ontario Ministry of Health (#04170)

Practice guidelines for use in the Communiy Dental Services Division of the North York Public Health Department: Guidelines for the use of professionally applied topical fluorides; the use of pit and fissure sealants; the use of dental radiographs, the use of space maintainers; when to place and initial restoration; posterior restorative materials and restoration replacement; infection control

North York is a municipality of Metropolitan Toronto with a population of approximately 560,000 people. The water supply has been fluoridated since 1963 and dental caries among children has fallen dramatically over the last 20 years. The average DMFT score in 1990 for a 13 year-old in North York was 1.97 but most of the burden of disease is born by a minority of children. The North York Public Health Department operates a school-based dental program that provides preventive and treatment services to children aged 3-14 years who are identified through a screening procedure. In an effort to allocate appropriately their limited resources and to obtain the best possible outcomes in this program, North York has an ongoing quality assurance process. One aspect of this quality assurance process involves the development, revision, and application of procedural or practice guidelines.The Community Dental Health Services Research Unit (CDHSRU) is a joint project of the Faculty of Dentistry, University of Toronto and the Dental Division, North York Public Health Department. It is supported by a grant from the Ontario Ministry of Health (#04170)