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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2005.04.039 Byline: J. Sudhir Ryan Daniel, Chandrasekharan Rajendran Abstract: This paper deals with the problem of determination of installation base-stock levels in a serial supply chain. The problem is treated first as a single-objective inventory-cost optimization problem, and subsequently as a multi-objective optimization problem by considering two cost components, namely, holding costs and shortage costs. Variants of genetic algorithms are proposed to determine the best base-stock levels in the single-objective case. All variants, especially random-key gene-wise genetic algorithm (RKGGA), show an excellent performance, in terms of convergence to the best base-stock levels across a variety of supply chain settings, with minimum computational effort. Heuristics to obtain base-stock levels are proposed, and heuristic solutions are introduced in the initial population of the RKGGA to expedite the convergence of the genetic search process. To deal with the multi-objective supply-chain inventory optimization problem, a simple multi-objective genetic algorithm is proposed to obtain a set of non-dominated solutions. Author Affiliation: Department of Management Studies, Indian Institute of Technology Madras, Chennai 600 036, India Article History: Received 26 August 2003; Accepted 14 April 2005

Aneurysms are bulges in arteries which reflect unhealthy state of conduit in which blood is flowing. In the aorta, they are typically found in the abdominal region as well as thoracic region. Understanding the rupture risk of these vessels is critical to preventing failure and fatalities. In the current clinical practice, treatment modalities are initiated, when the out‐pouching exceeds maximum diameter (Dmax). However this approach is very crude as it does not account for the fluid mechanical forces and the attendant stresses. Since it is medically and ethically not possible to follow the patients to study the rupture risk potential, fluid structure interaction (FSI) modelling would be an apt tool to develop adequate understanding on various hemodynamic parameters. On the other hand, performing patient‐specific studies would demand adequate lead time and they are computationally expensive as well. In the present study, the shape of the aneurysm and its interaction with the flowing fluid are accounted through the shape indices to study the FSI effects on the hemodynamic parameters. Numerical simulation of Newtonian flow through five axi‐symmetric geometries with different shape indices coupled with a linear elastic vessel wall model is considered. From these simulations, it was observed that (Dmax) to height ratio (DHr) is the most significant shape index which influences the variation of all hemodynamic parameters, which makes it a potential candidate for predicting rupture risk. Wall acceleration due to pulsatile flow was found to cause the onset of re‐circulation zones at the centre of the aneurysm during early systole and the temporal deceleration resulted in the generation of near wall eddying structures during late diastole. Investigation of turbulence carried out with k‐ω Shear Stress transport turbulence model, predicts a turbulence intensity of greater than 1.5% in the diseased segment as well as the distal end of the aneurysm. [ABSTRACT FROM AUTHOR]

Byline: J. Sudhir Ryan Daniel, Chandrasekharan Rajendran This paper presents simulation-based heuristic methodologies to compute installation base-stock levels in a serial supply chain so as to minimise the total supply chain cost. A simulated annealing heuristic is proposed to compute the installation base-stock levels for different installations in a serial supply chain. In addition, a simple heuristic to determine the installation base-stock levels is also presented. Simulation is used to evaluate the installation base-stock levels yielded by the proposed simulated annealing heuristic and the simple heuristic. A best-move local search is also used as a benchmark procedure. The solution constructed by the simple heuristic is initialised as the seed solution to both simulated annealing heuristic and the best-move local search, and their performances are studied. All the solution methodologies are extensively evaluated with different supply chain test problems. The solutions yielded by the proposed solution methodologies is compared against the optimal installation base-stock level which is obtained through a complete enumeration of the solution space for each of the supply chain test problems. A comparison of the performance of all the solution methodologies shows that the proposed simulated annealing heuristic initialised with the heuristic solution as the initial seed solution performs the best by consistently producing good-quality solutions with little computational effort.

Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Background : Tobacco smoking remains a leading risk factor for disease burden globally. In India alone, about 1 million deaths are caused annually by smoking. Although increasing tobacco prices has consistently been found to be the most effective intervention to reduce tobacco use, the documentation of prices and taxes across time and space has not been an essential component of tobacco control surveillance in most jurisdictions. This study aimed to examine, using graphical methods, trends in smoking tobacco taxes and prices in India at national and state-level. Methods : We used retail prices, price indices, and unit values (household expenditures on a commodity divided by the quantity purchased) collected and reported by government agencies. For bidis and cigarettes, we examined current and real (inflation-adjusted) prices, affordability (cost in terms of income), and key tax changes at both national and state-level. Results : We show that real prices of bidis and cigarettes were relatively flat (even decreasing in the case of bidis) between 2000 and 2007, and clearly increasing from 2010. When rising income is taken into account, however, both cigarettes and bidis have become more affordable since 2000. We found that some but not all tax changes were accompanied by price changes and in particular, that tax decreases did not result in price decreases. Conclusion : It is feasible to evaluate tax and price policies at national and regional level using routinely collected data., Competing Interests: No competing interests were disclosed.

Background: Revascularization surgery (RS) is the therapy of choice in moyamoya disease (MMD). Due to rarity of disease and ethical concerns, randomized controlled trials about the treatment options are lacking. Very little information is available on the long-term outcome of conservatively treated moyamoya patients., Aim: We compared the long-term outcome of moyamoya patients treated conservatively to those who underwent RS., Methods: Our study population included all patients with moyamoya disease/syndrome from 2002 to 2012. The demographic, clinical characteristic and imaging details were reviewed. The outcome was obtained prospectively., Results: Of the 36 patients, 26 (72.2%) had MMD and 10 (27.8%) had moyamoya syndrome. The median age at onset of symptoms was 17.5 years (range, 10 months-55 years). Fifteen patients belonged to pediatric group and 21 were adults. All the pediatric patients had ischemic events at onset and 10 (47.6%) of the adults presented with hemorrhage. Twenty (55.6%) patients received conservative treatment and 16 (44.4%) underwent revascularization procedures. The median duration of follow-up was 28 months (range, 3-90 months). Three (18%) of the surgically treated patients had recurrent ischemic events on follow-up, but none of the conservatively treated patients had events. An excellent outcome (Modified Rankin Scale of ≤2) was seen in 12 (75%) surgically treated and 16 (94%) conservatively treated patients (p=0.17)., Conclusion: Compared to East Asians, our patients had a lower stroke recurrence rate and good functional outcome even with conservative treatment. Future studies should focus on clinical and imaging predictors of progression to select moyamoya patients for RS., (© 2013 Elsevier B.V. All rights reserved.)

Solid waste is an unwanted byproduct of modern civilization. Landfills are the most common means of solid waste disposal. But the increasing amount of solid waste is rapidly filling existing landfills, and new sites are difficult to establish. Alternatives to landfills include the use of source reduction, recycling, composting and incineration, as well as use of landfills. Incineration is most economical if it includes energy recovery from the waste. Energy can be recovered directly from waste by incineration or the waste can be processed to produce storable refuse derived fuel (RDF). Information on the composition of solid wastes is important in evaluating alternative equipment needs, systems, management programs and plans. Pulverization of municipal solid waste is done and the pulverized solid waste is dressed to form a bed and the bed is fed by earthworms which convert the bed into vermi compost. The obtained vermi compost is sent to Ministry of Environment & Forests (MoEF) recognized lab for estimating the major nutrients, i.e. Potassium (K), Phosphorous (P), Nitrogen (N) and Micro-nutrient values. It is estimated that 59 - 65 tons of wet waste can be collected in a town per day and if this wet waste is converted to quality compost, around 12.30 tons of vermi compost can be generated. If a Municipal Corporation manages this wet waste an income of over (see text symbol) for 0.8 9 crore per anum can be earned which is a considerable amount for providing of better services to public.

We retrospectively analyzed a series of patients with brainstem cavernomas of the medulla, pons, or midbrain to attempt to define the natural history, indications for surgery, and outcome after surgical resection. Between 1993 and 2008, 52 patients with cavernomas of the brainstem presented to our institute and were managed either surgically or conservatively. Twenty-three patients underwent surgical excision using standard skull base approaches. Outcomes were correlated to the number of preoperative hemorrhages, location of the cavernoma, timing of surgery in relation to the hemorrhage and the preoperative neurological status. Nine patients improved after surgery, 12 deteriorated and two died. In the conservatively managed group, 15 patients had a good outcome, 11 deteriorated and one died. Multiple hemorrhages, poor preoperative neurological status and surgery during the acute phase were predictive of the surgical outcome. Excision of brainstem cavernomas should be considered in patients with symptomatic hemorrhages whose lesions approach the pial surface. Patients with minimal stable neurologic deficits without recurrent bleeds should be managed conservatively., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Intralesional floating fat globules have been reported in cystic lesions such as teratoma of the ovary and dermoid of the head and neck but not within intracranial lesions. Fat globules dispersed within the subarachnoid space are a known imaging finding of ruptured intracranial dermoid. We report a unique case of an intralesional solitary floating fat globule within a multicompartmental arachnoid cyst, with varying locations on serial imaging. We also put forward a hypothesis for the pathogenesis of fat within an arachnoid cyst. To the best of our knowledge, this is the first such report in the literature.

Objective: Bilateral thalamic lesions are rare and relatively obscure neoplasms. We present our experience with nine cases of bilateral thalamic lesions and attempt to analyse them in the background of available literature., Materials and Methods: Retrospective analyses of the case records of 9 cases of bilateral thalamic lesions treated in our department since January 2002, which have a minimum of 1 year follow-up., Results: The study group included four males and five females with a mean age of 14.6 years (5 years to 29 years). Seven of these patients had radiological evidence of bilateral thalamic lesions at presentation and 2 patients had involvement of the opposite thalamus at a later stage of the disease. All patients except one presented with raised intracranial pressure symptoms. Focal motor deficits (4/9), behavioral and memory disturbances (3/9) were the other major presenting symptoms. Biopsy confirmation was possible in six patients and histopathology was suggestive of low grade fibrillary astrocytoma in all six patients. Seven patients required CSF diversion procedure for associated hydrocephalus. Eight of our nine patients underwent radiotherapy. On last follow-up, 3 patients were clinically stable with images suggestive of arrested disease, four patients had evidence of progressive disease both clinically and radiologically and there were two recorded cases of mortality., Conclusion: Primary bilateral thalamic lesions have characteristic neuroradiological properties and are distinct from unilateral thalamic tumours with bilateral progression. Almost all of these lesions on histology prove to be gliomas but decompressive surgery is seldom feasible. Surgical intervention is limited to biopsy and CSF diversion for hydrocephalus. Bilateral thalamic lesions remain unresponsive to adjuvant therapy and generally carry a poor prognosis.

Lateral ventricular meningiomas are rare tumours that pose considerable surgical challenge. This study attempts to analyse some of the important clinical features of these tumours and review technical considerations in surgery for lateral ventricular meningiomas. A retrospective analysis of the case records of patients with lateral ventricular meningiomas operated in our institute since 1998 with a minimum of one year follow up was done. The variables analysed included age, sex, clinical presentation, imaging characteristics, histopathology and operative details. Outcome was analysed using the Glasgow outcome score (GOS). Fifteen patients with a mean age of 40.6 years formed the study group. A female preponderance was observed (M:F 5:10). Raised intracranial pressure was the predominant symptom at presentation (10/15; 66%) followed by visual field deficits (6/15; 40%) and contralateral motor deficits (5/15; 33.3%). One patient presented with evidence of intratumoural bleed. The tumour was on the right side in 7 patients and on the left side in 8 patients. The lesion was located in the trigone of the lateral ventricle in 13 patients and in the body of the ventricle in two. The tumours were excised through a parietooccipital approach in 11 (73.33%) patients and through a middle temporal gyrus approach in 4 (26.66%).The tumour recurred in 2 patients, both tumours being histologically fibroblastic variants. Fresh operative complications included motor deficits in 3, contralateral homonymous hemianopia in 2, dysphasia in 1, refractory seizures in 2 and loculated hydrocephalus in one. We had no operative mortality. At last follow-up for 10 patients were in GOS 5, two were in GOS 4 and three in GOS 3. Lateral ventricular meningiomas are difficult tumours to operate. Total surgical excision through a superior parietal lobule or middle temporal gyrus approach is possible in most cases with minimal morbidity.

Background: The aim is to study the clinical, radiological and pathological features of childhood and adolescent meningiomas and analyse outcome prognosticators., Method: A retrospective analysis of the case records of patients less than 20 years of age operated for a meningioma in our institute since 1982 was performed. The variables analysed included age, sex, presentation, associated neurofibromatosis (NF), imaging characteristics, extent of resection and histopathology., Results: The study group included 20 males and 18 females with a mean age of 15.53 years. Eleven children (28.9%) had evidence of NF of whom three had NF2 with bilateral vestibular schwannomas. The common presenting symptoms were seizures (76.3%), raised intracranial tension (71%), and focal neurological deficits (39.4%). The location of the operated tumours were as follows: ten skull base (24.4%), ten falx/parasagittal (24.4%), eight spinal (19.5%), five convexity (12.2%), three posterior fossa (7.3%), three intraventricular (7.3%) and two optic nerve sheath (4.9%). Two children (4.9%) had cystic meningiomas. Grade I excision was achieved only in twenty tumours (48.8%). On histopathology, thirty (73.2%) were grade I, nine (21.9%) were grade II and two (4.9%) were grade III meningiomas. Seven tumours recurred of which six were located at the skull base. During the mean follow up period of 4.74 years, the majority, 32 (84.2%) had a good outcome and five (13.2%) had a poor outcome. One child (2.6%) expired due to post-operative sepsis., Conclusion: Childhood meningiomas are uncommon but not rare lesions with a marginal male predominance. Absence of large series with long follow up precludes any definite conclusions on the clinical course and outcome. Uniform observations made in different series including ours, include a higher incidence of the skull base location and tumours with atypical histopathology. Favourable prognostic factors include younger age (< than 10 years), superficial location, total excision and absence of neurofibromatosis. Location and extent of excision appear to be more important than histopathology grade in predicting outcome.