1,757 research outputs found
Effect of Landauer's blowtorch on the equilibration rate in a bistable potential
Kinetic aspect of Landauer's blowtorch effect is investigated for a model
double-well potential with localized heating. Using the supersymmetric
approach, we derive an approximate analytical expression for the equilibration
rate as function of the strength, width and the position of the hot zone, and
the barrier height. We find that the presence of the hot zone enhances the
equilibration rate, which is found to be an increasing function of the strength
and width of the hot zone. Our calculations also reveal an intriguing result,
namely, that placing the hot zone away from the top of the potential barrier
enhances the rate more than when it is placed close to it. A physically
plausible explanation for this is attempted. The above analytical results are
borne out by detailed numerical solution of the associated Smoluchowski
equation for the inhomogeneous medium.Comment: 15 pages in LaTeX format and 6 figures in postscript E-Mail :
[email protected] [email protected]
Case Report: Corneal Pyogenic Granuloma: Rare Complication of Infectious Keratitis
Background: Pyogenic granuloma is an excessive proliferation of granulation tissue that usually develops after minor trauma or surgery. Ocular involvement usually happens on the external surface and cornea is rarely involved. The objective of our report is to describe the clinicopathological feature of this rare disease and give insight on clinical features that help in the diagnosis.Case Report: This report presents a case of a four year old child who had fleshy growth of one week duration on the right eye after seven weeks of pain and redness. Slit lamp examination showed vascularized central corneal mass with surrounding stromal infiltrates. The mass was excised, and histopathological examination confirmed pyogenic granuloma of the cornea.Conclusion: Corneal pyogenic granuloma could be a rare complication of infectious keratitis. Therefore, it should be considered as a differential diagnosis in corneal mass especially after an infection or trauma.Keywords: Pyogenic Granuloma, Corneal pyogenic granuloma, Keratitis, Post-infectious granulom
Water Supply and Health: Drinking water and Sanitation Coverage in Ethiopia 1990 - 2015 Review
Background: Human health, incorporating physical, social and psychological well-being, depends on an adequate supply of potable water and a safe environment sections. Waterborne infections are one of the commonest problems in developing countries. Access to safe drinking water and basic sanitation needs will eliminate vast part of water-borne disease cases.
Objectives: to assess the trends safe water coverage and sanitary conditions in Ethiopia together with the challenges of the sector.
Methods: In depth literature survey from online published peer reviewed articles, publications from International organization and Ethiopia ministry of health was used to assess the trend and access of improved water and sanitation coverage since 1990 to 2015 in Ethiopia.
Results: Among 93 articles, 45 of them have important information and included in the quantitative review. To this end Ethiopia has reached the Millennium Development goal of access to safe water and the national coverage reached to 68.5% and 33% for sanitation facilities. Ethiopia is not on the right track to reach for sanitation target (47%) of 2015. The development trend for water coverage and sanitation facilities shows that urban dwellers (16% of the population) are more benefited than the rural (84%) citizens. Poor access of sanitation and improved drinking water in rural part is resulted due to improper planning, malfunction water scheme utilities, and other factors.
Conclusions: Despite, the efforts made to increase the access to safe drinking water and sanitation facilities to the population in the last 15 years; water related diseases are still one of the top ten diseases in the country. Protecting the source alone is not sufficient enough to reduce waterborne diseases unless point of use treatments and hygienic handling of water is practiced. Additional commitments and efforts are required post 2015 to assure the sustainability, access to the basic human right, water
Surgically treated acute abdomen at Gondar University Hospital, Ethiopia.
Background: Acute abdomen is an acute onset of abdominal disease entities that require immediate surgical intervention in most of the cases. The numbers of researches done on acute abdomen in general are Very few in Ethiopia. The main objective of this study was to document the burden of acute abdomen in general and the outcome of emergency laparotomyMethods: This was a retrospective study on surgically treated acute abdomen performed at Gondar University Hospital (GUH) from September 1998 to August 2002Results: More than 1 in 10 operations done in GUH were for acute abdomen. Nearly a quarter of the operations performed in the study period were laparotomies, 43.3% of which were on emergency bases. Majority of surgically treated acute abdomen patients were from rural areas (58.2%). The sex composition was significantly different by place of residence (X2= 12.74, p=0.0017). Abdominal pain (100%), Vomiting (90.3%), abdominal distension (58.3%) and constipation (55.3%) were the commonest symptoms in patients with acute abdomen.Conclusion: This study has shown what the commonest symptoms of acute abdomen are and that the outcome of emergency laparotomy may be affected by different factors. Some of these factors were duration of illness, age, presence of peritonitis, Haematocrit level and complication detection time. Since the management is almost the same for almost all causes of surgical acute abdomens, the abovementioned factors should be given due attention in handling such patients. The reasons for low appearance of rural female dwellers to better health care centres need to be investigated
Work-related operating theatre accidents among surgical residents in Addis Ababa, Ethiopia
Background: With the Human Immunodeficiency virus (HIV) epidemic and infections with hepatitis B, C and D, occupational exposures to these infections is a cause of concern to all health care workers, especially those working in the operating theatre in low income countries.Methods: A cross-sectional study was conducted to investigate the prevalence and context of all work-related accidents that occurred as a result of contamination with blood and blood products, among surgical residents at the Black lion teaching specialized referral hospital, in Addis Ababa, Ethiopia. Data was collected from all 36 surgical residents who were at different stages of their specialty training in 2006/07.Results: Thirty two (88.9%) of the residents were males; 17 (47.2%) in their 3rd and 4th year, and the rest 19 (52.8%) were in their first and second year of training. Of the 36 respondents, 28(77.8%) had sustained a needle-stick injury inside the operating theatre at least twice during their residency (Range=2-10 times). For 13(36.1%), the accidents involved a high risk patient at least once. Cut with a sharp object, contact of blood to an unprotected skin and splash of blood to the eyes and face were reported by 11(30.6%), 27(75%) and 27(75%) of the respondents respectively. Information concerning the most recent occupational injury inside the operating theatre revealed that 31(86.1%) of the residents sustained work-related accident in the 6 months preceding the survey, 8(25.8%) of which involved a high risk patient. All of the 8 (100%) of the recent high risk injuries and 22(95.6%) of the non-high risk injuries were not reported to the hospital’s employee health service. The most frequently cited reasons for not reporting include; “The occupational health service doesn’t exist or I don’t know if it exists in the hospital” for 15 (50%), among others.Conclusions and Recommendations: Overall, the present study revealed that work-related accidents among surgical trainees constitute a substantial risk of acquiring and transmitting blood-borne infections which calls for well targeted educational and other preventive measures in the teaching hospital
Vegetation Composition in Hugumbirda-Gratkhassu National Forest Priority Area, South Tigray
The floristic composition and structure of the vegetation of Hugumbirda-Grat-Khassu forest, South Tigray, Northern Ethiopia is described and related to environmental factors. To analyze the vegetation and environmental data seventy-four relevè ( 20m x 20m) were used. For each species the cover/abundance value was estimated. Height and diameter at breast height (DBH) of all woody individuals taller than 2 m and thicker than 2 cm were measured. Importance Value Index was calculated for 24 tree/shrub species and the result helped to identify the five dominant tree/shrub species and to show the overall forest situation. The species and relevès were classified with the two-way indicator species analysis program TWINSPAN. We recorded 102 species belonging to 83 genera and 50 families. Five community types are described: Allophylus macrobotrys-Ficus sur, Nuxia congesta-Podocarpus falcatus, Acacia abyssinica-Olea europaea, Myrica salicifolia-Erica arborea-Maesa lanceolata and Acacia etbaica- Dichrostachys cinerea-Acacia tortilis type. Of these, community type 2 has high species richness while community type 3 is poor in species richness. The general arrangement of all species was found to show high density at lower height and DBH classes. Based on the cumulative results of Importance Value Index, Juniperus procera, Olea europaea subsp. cuspidata, Nuxia congesta, Cassipourea mallosana and Olinia rochetiana were identified to be the most dominant tree species of the forest and they contributed 71.43% of the basal area. Analysis of community-environment relationships didn’t show significant differences except for altitude and slope.
Key words: Community, DBH, Floristic composition, Forest structure, Releve, Vegetation classification
Levels and Trends of Occupational Hazards among Surgical Residents at Tikur Anbessa Hospital, Addis Ababa Ethiopia
Background: A previous study conducted four years ago among surgeons-in-training at the Addis Ababa University revealed that work-related accidents among surgical trainees were enormous, and there was huge under reporting to the occupational health unit (OHU) of the hospital. The aim of this study was to evaluate the impact of the strengthened OHU of the hospital and what the current status of work-related accidents is like at the same hospital three years later.Methods: A cross-sectional study was conducted to investigate the prevalence and context of all work-related accidents that resulted in contamination with blood and blood products inside the operating theatre, among surgical residents at the Tikur Anbessa teaching specialized referralhospital, in Addis Ababa University, Ethiopia. Data was collected from all 76 surgical residents who were at different stages of their specialty training in 2011.Results: Seventy- two (94.7%) of the residents were males and 26 (34.2%) were in their 3rd and 4th year of training. Of the 76 respondents, 53 (69.8%) had sustained a needle-stick injury inside the operating theatre at least once during their residency (Range=1-15 times). For 20 (26.3%), the accidents involved a high risk patient at least once. Cut with a sharp object, contact of blood to an unprotected skin and splash of blood to the eyes and face were reported by 9 (11.7%), 39(51.3%) and 28(36.9%) of the respondents respectively. Information concerning the most recent injuries inside the operating theatre revealed that 46(69.7%) of the residents sustained accidents in the 6 months preceding the survey, 7(9.2%) of which involved a high risk patient. All of the 7 (100%) of the recent high risk injuries and 10(27.7%) of the low-risk injuries were reported to the OHU and all the high risk injury victims were commenced on HIV prophylaxis.Conclusions and Recommendations: Overall, the study revealed that work-related accidents among surgical trainees are still unacceptably high, even though there is a decline in the number of sharp object cut, and blood splash accidents. However, there is a positive trend towards reporting of injuries, particularly those which are high risk. More is expected from the hospital to create a safe working environment and to encourage reporting of all form of injuries
Aspergilloma of the lungs: Operative experience from Tikur Anbessa Hospital, Ethiopia
Background: Pulmonary aspergilloma represents a potentially life-threatening disease caused by saprophytic growth of Aspergillus fumigates in pulmonary cavities. This is the first report of its operative treatment from Ethiopia.The aim of this study was to determine the clinical presentations, operative treatments and post operative outcome of patients with pulmonary aspergilloma.Methods: This was a retrospective review of patients’ record with post operative diagnosis of pulmonary aspergilloma treated over a period of three years between April 2005-March 2008 at The Tikur Anbessa hospital which is a teaching and referral hospital in Addis Ababa.Results: Eleven patients were included, 81.8% of whom were males. Cough and hemoptysis were the two most common presenting symptoms, occurring in 11(100%) and 10(90.9%). The chest x-ray features typical for aspergilloma was seen in only 4(36.4%). The left lung was involved in 8(72.75%) and the upper lobes were the most commonly affected lobes occurring in 10 (90.9%). The most frequent clinical indication for surgery was severe hemoptysis in 8 (72.75%). Left upper lobectomy was the most frequently performed surgery in 4(36.4%) and left pneumonectomy in 3(27.3%). Four significant complications occurred in the postoperative period and one patient died, making the postoperative mortality 9.1%. Histopathologic confirmation of the fungal ball was possible in 10 patients and the most common underlying cavitary disease was tuberculosis in 9(90%).Conclusion: Aspergilloma is not an uncommon disease in Ethiopia and the diagnosis should be considered in patients who present with hemoptysis or chronic non-resolving cough. Surgery for pulmonary aspergilloma accounted for 5.8% of all thoracotomies done at the hospital and we have adopted the policy of early surgical treatment for all cases. In our series, the commonest lung pathology behind the aspergillus lesions was cavitary pulmonary tuberculosis, similar to many reports. Since the typical x/ray finding is not present in all patients, we believe that a supportive x/ray finding is sufficient enough an investigation to decide on early surgery in patients who present with suggestive symptoms
The Gap between Surgical Resident and Faculty Surgeons Concerning Operating Theatre Teaching: Report from Addis Ababa, Ethiopia
Background: In a continent like Africa where the number of surgeons is alarmingly few, training of a large number of residents is the way forward. However, sudden expansion in the number of trainees in an existing teaching environment may bring the quality of the most fundamentaleducation i.e. operation room teaching into question.Method: We wanted to investigate the different perceptions of our surgeons-under-training and faculty concerning preoperative preparation, intra operative teaching and postoperative feedback. A validated questionnaire was administered to our surgical residents and faculty at the Addis Ababa University, School of Medicine, Department of Surgery. Results were analyzed with 2-sample t tests, comparing Likert scores. Findings were significant if the p value was < 0.05.Results: Forty residents (15 second year, 15 third years and 10 final years) and 30 faculty members completed the survey. With respect to preoperative preparation, faculty were significantly more likely to claim that residents’ preparation in terms of reading is low (3.77 vs 2.45; p=0.001) and anatomy review (3.73 vs 2.34; p=0.001) before the procedure. There was a very significant difference with regards to intra-operative teaching activities, i.e teaching of the operative steps (2.60 vs 3.79; p=0.048), instrument handling (2.30 vs 3.72; p=0.002), and surgical technique (2.23vs 3.83; p= 0.001). Residents’ perception of the effort of the faculty to act as a teacher in the operating room was significantly lower compared to the faculty (2.13 vs 3.94; p=0.002). Postoperatively, significant differences were found in perceptions of positive feedback (2.48 vs 3.86; p=0.01) and feedback on areas to improve (1.85 vs 3.34; p=0.001).Conclusion: There is a universal agreement on the need to improve the current residency training. However, the difference between resident and faculty in the teaching-learning process is alarmingly significant. As there is no substitute for the intra-operative training of residents, every effort must be made to not to trade off number of graduates with quality and competence of surgeons-under-training. Keywords: Resident, Surgeons, Operating, Theatre, Teachin
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