Asymptotic behaviour of the Rayleigh--Taylor instability

We investigate long time numerical simulations of the inviscid Rayleigh-Taylor instability at Atwood number one using a boundary integral method. We are able to attain the asymptotic behavior for the spikes predicted by Clavin & Williams\cite{clavin} for which we give a simplified demonstration. In particular we observe that the spike's curvature evolves like $t^3$ while the overshoot in acceleration shows a good agreement with the suggested $1/t^5$ law. Moreover, we obtain consistent results for the prefactor coefficients of the asymptotic laws. Eventually we exhibit the self-similar behavior of the interface profile near the spike.Comment: 4 pages, 6 figure

New Algorithm for Parallel Laplacian Growth by Iterated Conformal Maps

We report a new algorithm to generate Laplacian Growth Patterns using iterated conformal maps. The difficulty of growing a complete layer with local width proportional to the gradient of the Laplacian field is overcome. The resulting growth patterns are compared to those obtained by the best algorithms of direct numerical solutions. The fractal dimension of the patterns is discussed.Comment: Sumitted to Phys. Rev. Lett. Further details at http://www.pik-potsdam.de/~ander

A study of adverse drug reaction profile of tuberculosis patients attending DOTS center at Dr. Bhim Rao Ambedkar memorial hospital, Raipur, Chhattisgarh, India

Background: Tuberculosis is second leading cause of death in the world. The causative organism is Mycobacterium tuberculosis. The objective was to study the adverse reactions of the patients attending the DOTS center and to assess their causality and severity of reported ADRs.Methods: Present study was a prospective observational study carried at the DOTS center of Dr. Bhim Rao Ambedkar Memorial Hospital, Raipur, Chhattisgarh, India between August 2011 to July 2012 (One year). The patients were monitored for adverse drug reactions. The assessment of ADRs were based upon the WHO assessment scale, Naranjo scale, European A.B.O scale.Results: Total number of patients attending DOTS center was 816. The number of males (428) exceeded that of females (388). Majority of patients in this study belonged to 21-30 years (26.96%) next 31-40 years (25.24%) and 41-50 years (16.5%) of age group. Prevalence of ADRs were more in males (57%) than in females 32 (43%). Majority of ADRs reported were moderate 33 (35.22%) followed by 29 (46,77%) were mild, no severe ADRs reported. According to severity of ADRs seen were gastritis 28 (45%) followed by 10 (16% ) rashes , 10 (16,12%) of arthralgia, 3 (4.83%) of hepatitis, 6 (9.7%) of peripheral neuropathy, 2 (3%) onsets of ADRs after starting anti-tubercular drug were 12 (19.35%) in 0-1 week followed by 19 (30%) ADRs showed onset in 1-2 week and 2-3 week, 8 (13%) in 3-4 week 3 (5%) in 4-5 week and 1 (2%) in 5-6 week.Conclusions: The casual link between the ADRs and the suspected anti-tubercular drug by Naranjo scale definitely relationship was established between the anti-tubercular drug and ADRs in 7 (11.25%) patient while 22 (35.45%) probable and 33 (53.22%) ADRs were categorized as possible

Rationality verses irrationality in fixed dose combinations: at a tertiary teaching hospital of rural Chhattisgarh, India

Background: Rational drug prescribing can be defined as appropriate drugs prescribed in the right dose, at correct time intervals and for a sufficient duration. Irrational drug use is a common problem in many countries of the world.Methods: A prospective observational study was conducted, total 300 patients attending various outpatient departments of tertiary health care rural hospital in Rajnandgaon district were interviewed and their prescriptions were analysed.Results: Total 350 drugs were prescribed 60 (17.14%) were prescribed by generic name and the rest 290 (82.86%) were prescribed by brand name. Only 18 (5.14%) drugs were not prescribed from hospital formulary. 264 (75.43%) drugs were dispensed from hospital pharmacy. On the basis of rationality score 53% prescriptions were rational, 30% semi rational and 17% irrational.Conclusions: In a rural hospital, where hospital formulary is based on WHO Essential medicine list, hundred percent utilization of hospital pharmacy service doctors and patients would ensure rational prescribing benefits of the patients coming from rural and uneducated background

Self-perceived barriers to eye care in a hard-to-reach population: The Karachi marine fishing communities eye and general health survey

Abstract Purpose.: We examined self-reported barriers to eye care among marginalized, hard-to-reach fishing communities in Karachi, Pakistan. Methods.: The Karachi Marine Fishing Communities Eye and General Health Survey was a cross-sectional survey conducted between March 2009 and April 2010 in fishing communities in Keamari, Karachi, located on the coast of the Arabian Sea. Adults aged ≥50 years living on seven islands and coastal areas were interviewed regarding sociodemographic background, experience of eye problems, eye care use, and barriers to access. They also were examined to determine visual acuity with a reduced logMAR chart and underwent a detailed eye examination. Results.: Of 700 people planned to be included in the study, 638 (91.1%) were interviewed and examined. Of these participants, 599 (93.9%) lived in extreme poverty and 84.3% had no school-based education, and 349 (54.7%; 95% confidence interval [CI], 50.8–58.6) of them had never had an eye examination. The common barriers to access identified included a perceived lack of or low need (176/349 or 50.4%), financial hardships (36.4%), “fears” (8.6%), and social support constraints (6.3%). Of those reporting a “lack of need,” 21.9% had significant visual loss. Financial hardships, “fears,” and social support constraints were more prevalent among women than men. Bengalis compared to Kutchis and Sindhis, and individuals with “poor/fragile” household financial status (self-reported) compared to those with “fine” status, were more likely to cite financial hardships. Conclusions.: Access to eye care in this marginalized population is substantially hindered by perceived lack of need, financial hardships, and a range of “fears” and anxieties, despite a large unmet need. These barriers should be addressed while paying particular attention to gender, and ethnic and socioeconomic differences

Assessment of knowledge of pharmacotherapeutics amongst medical undergraduates of a tertiary care teaching hospital of Chhattisgarh, India: a questionnaire based study

Background: Knowledge of pharmacology forms the basis of rational pharmacotherapy practice. Teaching the medical students about systematic application of pharmacology in patients’ care forms an essential component. It facilitates the medical students to develop a methodical approach in solving patients’ clinical problems.Methods: A questionnaire-based study was conducted, at Government Medical College Rajnandgaon involving second year MBBS students. Total 100 students participated in the study.Results: Hundred percent of the students responded that pharmacology was presently taught to them, seventy nine percent of them agreed with the fact that pharmacology was preferred to pass the MBBS, eighty eight percent of them responded that in pharmacokinetics was the least preferred topic, ninety seven of them were not aware of the essential drug list. Their suggestions regarding the change in teaching methodology was recorded.Conclusions: This study concludes that efforts are needed to develop a curriculum that encompasses important aspects of clinical pharmacology and therapeutics along with incorporation of the useful suggestions by the undergraduate students

Cystic artery pseudo-aneurysm: a complication of xanthogranulomatous cholecystitis

A 54-year-old man presented for radiology with pain and a feeling of fullness in the upper abdomen and an epigastric mass. Ultrasound revealed a large cystic mass with internal echoes, lying posterior and inferior to left lobe of the liver. The gallbladder was thick-walled and contracted, and contained a calculus and echogenic sludge. A cystic structure that produced swirling flow signals on colour Doppler was demonstrated within the gallbladder. The CT scan showed a thickened gallbladder with adjacent inflammation and a 2-cm pseudo-aneurysm in its wall. High-density material was present in the gallbladder lumen, in the extra-hepatic bile ducts and around the gastrohepatic ligament. A thick haemorrhagic pus, from which Escherichia coli was cultured, was drained from the gastrohepatic collection. An elective coeliac angiogram demonstrated a solitary pseudo-aneurysm of the medial branch of the cystic artery. Selective catheterisation of this artery with a micro-catheter enabled complete exclusion of the pseudo-aneurysm by a single micro-coil. Histological examination of the gallbladder, which was ultimately removed at open cholecystectomy, demonstrated xanthogranulomatous cholecystitis

Iterated Conformal Dynamics and Laplacian Growth

The method of iterated conformal maps for the study of Diffusion Limited Aggregates (DLA) is generalized to the study of Laplacian Growth Patterns and related processes. We emphasize the fundamental difference between these processes: DLA is grown serially with constant size particles, while Laplacian patterns are grown by advancing each boundary point in parallel, proportionally to the gradient of the Laplacian field. We introduce a 2-parameter family of growth patterns that interpolates between DLA and a discrete version of Laplacian growth. The ultraviolet putative finite-time singularities are regularized here by a minimal tip size, equivalently for all the models in this family. With this we stress that the difference between DLA and Laplacian growth is NOT in the manner of ultraviolet regularization, but rather in their deeply different growth rules. The fractal dimensions of the asymptotic patterns depend continuously on the two parameters of the family, giving rise to a "phase diagram" in which DLA and discretized Laplacian growth are at the extreme ends. In particular we show that the fractal dimension of Laplacian growth patterns is much higher than the fractal dimension of DLA, with the possibility of dimension 2 for the former not excluded.Comment: 13 pages, 12 figures, submitted to Phys. Rev.