On negative higher-order Kerr effect and filamentation

As a contribution to the ongoing controversy about the role of higher-order Kerr effect (HOKE) in laser filamentation, we first provide thorough details about the protocol that has been employed to infer the HOKE indices from the experiment. Next, we discuss potential sources of artifact in the experimental measurements of these terms and show that neither the value of the observed birefringence, nor its inversion, nor the intensity at which it is observed, appear to be flawed. Furthermore, we argue that, independently on our values, the principle of including HOKE is straightforward. Due to the different temporal and spectral dynamics, the respective efficiency of defocusing by the plasma and by the HOKE is expected to depend substantially on both incident wavelength and pulse duration. The discussion should therefore focus on defining the conditions where each filamentation regime dominates.Comment: 22 pages, 11 figures. Submitted to Laser physics as proceedings of the Laser Physics 2010 conferenc

Makerere University College of Health Sciences’ role in addressing challenges in health service provision at Mulago National Referral Hospital

<p>Abstract</p> <p>Background</p> <p>Mulago National Referral Hospital (MNRH), Uganda’s primary tertiary and teaching hospital, and Makerere University College of Health Sciences (MakCHS) have a close collaborative relationship. MakCHS students complete clinical rotations at MNRH, and MakCHS faculty partner with Mulago staff in clinical care and research. In 2009, as part of a strategic planning process, MakCHS undertook a qualitative study to examine care and service provision at MNRH, identify challenges, gaps, and solutions, and explore how MakCHS could contribute to improving care and service delivery at MNRH.</p> <p>Methods</p> <p>Key informant interviews (n=23) and focus group discussions (n=7) were conducted with nurses, doctors, administrators, clinical officers and other key stakeholders. Interviews and focus groups were tape recorded and transcribed verbatim, and findings were analyzed through collaborative thematic analysis.</p> <p>Results</p> <p>Challenges to care and service delivery at MNRH included resource constraints (staff, space, equipment, and supplies), staff inadequacies (knowledge, motivation, and professionalism), overcrowding, a poorly functioning referral system, limited quality assurance, and a cumbersome procurement system. There were also insufficiencies in the teaching of professionalism and communication skills to students, and patient care challenges that included lack of access to specialized services, risk of infections, and inappropriate medications.</p> <p>Suggestions for how MakCHS could contribute to addressing these challenges included strengthening referral systems and peripheral health center capacity, and establishing quality assurance mechanisms. The College could also strengthen the teaching of professionalism, communication and leadership skills to students, and monitor student training and develop courses that contribute to continuous professional development. Additionally, the College could provide in-service education for providers on professionalism, communication skills, strategies that promote evidence-based practice and managerial leadership skills.</p> <p>Conclusions</p> <p>Although there are numerous barriers to delivery of quality health services at MNRH, many barriers could be addressed by strengthening the relationship between the Hospital and MakCHS. Strategic partnerships and creative use of existing resources, both human and financial, could improve the quality of care and service delivery at MNRH. Improving services and providing more skills training could better prepare MakCHS graduates for leadership roles in other health care facilities, ultimately improving health outcomes throughout Uganda.</p

Prevalence of oral diseases/conditions in Uganda

Objective: The aim was to report the prevalence of oral diseases/conditions among a Ugandan population. Methods: Subjects aged 12 (n=696) and 35-44 years (n=396) were chosen from randomly selected urban and peri-urban areas of Arua, Mbale, Kampala and Mbarara districts. They were clinically examined by 4 trained and calibrated dentists for oral diseases/ conditions using criteria described by World Health Organisation. Results: Dental caries (DMFT ≥1) was recorded in 40% and 62.5% of the children and adults, respectively. The overall mean DMFT score was 0.9 for children and 3.4 for adults. Caries was significantly more severe in females as compared to males in children (p<0.05), whereas in adults, there was no significant gender difference. Kampala had a significantly higher mean DMFT score compared to other districts in all age groups (p>0.05). Culculus deposits were generally, more prevalent in adults as compare to children except in Mbarara district. Gum bleeding was also significantly more prevalent among children as compared to adults (p<0.05). Significantly higher prevalence of gum bleeding in both children and adults was recorded in Arua district as compared to other areas (p<0.05). Each of the age groups had a prevalence of malocclusion of 61%. However, the severity of malocclusion varied between age groups and districts. The prevalence of dental fluorosis was 3% and 4% for children and adults, respectively. All subjects in Arua district were fluorosis-free. Tetracycline enamel staining was less than 1% in both age groups. Enamel attrition was more prevalent in adults as compared to children: 19% versus 1%. Conclusion: The prevalence of oral diseases/conditions was generally low among the study population. Caries experience was significantly higher in the Kampala (urban) district as compared to rural districts in all age groups; the D - component being the major contributor