Fuzzifying [sic] Markov decision process

Markov decision processes have become an indispensable tool in applications as diverse as equipment maintenance, manufacturing systems, inventory control, queuing networks and investment analysis. Typically we have a controlled Markov chain on a suitable state space in which transitional probabilities depend on the policy (or decision maker) which comes from a set of possible actions. The main problem of interest would be to find an optimal policy that minimizes the associated cost. Linear Programming has been widely used to find the optimal Markov decision policy. It requires solutions of large systems of simultaneous linear equations. By the fact that the complexity in linear programming increases much faster with the increase in the number of states which is often called curse of dimensionality, the linear programming method can handle only small models. This thesis presents a new method to lessen the curse of dimensionality. By assuming certain monotonicity property for the transition probability, it is shown that a fuzzy membership function can be used to reduce the number of states. The use of membership functions help to reduce the number of the states. However all the states remain intact through the use of the membership value. That is, those states eliminated can be recovered through interpolation with the aid of membership functions. This new proposed method is shown to be effective in coping with the curse of dimensionality

Wild Edibles of Kishtwar High Altitude National Park in Northwest Himalaya, Jammu and Kashmir (India)

The use of wild edible plants can contribute vitamins, protein and fat to the human diet besides being an important source of cash-earning to the locals. Spread over an area of 425 km2, Kishtwar High Altitude National Park lies between 33° 20΄ to 34º 40΄ North latitude and 75º 40΄ to 76º 10΄ East longitude. A sizable area of the National Park is inhabited by the indigenous population. The area of the National Park includes 35 villages with about 20000 human population besides nomadic Gujjar and Bakerwals who bring their sheep and cattle for grazing during summer. The economically weak populace of the area is mostly dependent on the agriculture and the wild resources for their day today needs. This paper presents information on the edibility of 50 plants species used traditionally by local inhabitants in Kishtwar High Altitude National Park (KHANP). Majority of plant species belong to angiosperms (42 species) followed by gymnosperms (2 species) and Pteridophytes (2 species), whereas 4 species belong to fungi. As for as the edibility is concerned majority of the plant species (21 species) are exploited for fruit, 19 serve as vegetables, 4 species as flavoring agents (spices), roots and/or leaves of 3 species are eaten as raw, 3 species as tea substitute, whereas 2 species are used in making special drinks. Edible oils are obtained from the kernels of Juglans regia and Prunus armeniaca which are served with meals as such or used as cooking oil. Some of these species also play an important role in income generation for most of the families living in KHANP

The co-evolved Helicobacter pylori and gastric cancer: trinity of bacterial virulence, host susceptibility and lifestyle

Helicobacter pylori is an important yet unproven etiological agent of gastric cancer. H. pylori infection is more prevalent in developing Asian countries like India and it is usually acquired at an early age. It has been two decades since Marshall and Warren (1984) first described curved bacilli in the stomach of ulcer and gastritis patients. This discovery has won them the Nobel Prize recently, but the debate whether H. pylori is a pathogen or a commensal organism is still hot. Associations with disease-specific factors remain illusive years after the genome sequences were made available. Cytotoxin-associated antigen A (CagA) and the so-called plasticity region cluster genes are implicated in pathogenesis of the carcinoma of stomach. Another virulence factor VacA whose role is still debatable, has recently been projected in pathology of gastric cancer. Studies of the evolution through genetic variation in H. pylori populations have provided a window into the history of human population migrations and a possible co-evolution of this pathogen with its human host. Possible symbiotic relationships were seriously debated since the discovery of this pathogen. The debate has been further intensified as some studies proposed H. pylori infection to be beneficial in some humans. In this commentary, we attempt to briefly discuss about H. pylori as a human pathogen, and some of the important issues linked to its pathophysiology in different hosts. 'We dance around in a ring and suppose, the secret sits in the middle and knows' – Robert Fros

Urinary retention in unilateral total knee arthroplasty: Comparison between continuous epidural analgesia and single-shot femoral nerve block

Objective: To compare the frequency of urinary retention and requirement of bladder catheterization in patients undergoing total knee arthroplasty while receiving either continuous epidural analgesia or single-shot femoral nerve block.Study design: Randomized controlled study.Place and duration of study: Operating Rooms of Aga Khan University Hospital, Karachi, from January 2014 to January 2015.Methodology: Patients were randomized in two groups of 30 each, i.e. epidural group (group E) or femoral nerve block group (group F). Baseline parameters were recorded. Postoperatively, patients were followed for upto 24 hours to collect the data regarding urinary retention. Final outcome was taken at 24 hours postoperatively. Data was analyzed to compare the frequency of urinary retention between the two groups.Results: The average age of the patients was 59.58 ±5.85 years. There were 28 (46.7%) male and 32 (53.3%) female patients. Frequency of urinary retention was significantly high in Group E than Group F (46.7% vs. 6.7%; p=0.0005).Conclusion: Single-shot femoral nerve block offers a more favorable profile in terms of postoperative urinary retention when compared to continuous epidural analgesia