82 research outputs found
Ballooning Multi-Armed Bandits
In this paper, we introduce Ballooning Multi-Armed Bandits (BL-MAB), a novel
extension of the classical stochastic MAB model. In the BL-MAB model, the set
of available arms grows (or balloons) over time. In contrast to the classical
MAB setting where the regret is computed with respect to the best arm overall,
the regret in a BL-MAB setting is computed with respect to the best available
arm at each time. We first observe that the existing stochastic MAB algorithms
result in linear regret for the BL-MAB model. We prove that, if the best arm is
equally likely to arrive at any time instant, a sub-linear regret cannot be
achieved. Next, we show that if the best arm is more likely to arrive in the
early rounds, one can achieve sub-linear regret. Our proposed algorithm
determines (1) the fraction of the time horizon for which the newly arriving
arms should be explored and (2) the sequence of arm pulls in the exploitation
phase from among the explored arms. Making reasonable assumptions on the
arrival distribution of the best arm in terms of the thinness of the
distribution's tail, we prove that the proposed algorithm achieves sub-linear
instance-independent regret. We further quantify explicit dependence of regret
on the arrival distribution parameters. We reinforce our theoretical findings
with extensive simulation results. We conclude by showing that our algorithm
would achieve sub-linear regret even if (a) the distributional parameters are
not exactly known, but are obtained using a reasonable learning mechanism or
(b) the best arm is not more likely to arrive early, but a large fraction of
arms is likely to arrive relatively early.Comment: A full version of this paper is accepted in the Journal of Artificial
Intelligence (AIJ) of Elsevier. A preliminary version is published as an
extended abstract in AAMAS 2020. Proceedings of the 19th International
Conference on Autonomous Agents and MultiAgent Systems. 202
Experimental Models on Diabetes: A Comprehensive Review
Present world scenario globally, upto 2010, around 285 million people suffering from Type 2 diabetes making up about 90% of the cases. According to statistics, by 2030, this number is estimated to almost double. Diabetes mellitus occurs throughout the world, but is more common (especially Type 2) in the more developed countries. The greatest increase in prevalence is, however, expected to occur in Asia and Africa, where most patients will probably be found by 2030. The aim of this review is to summarize several studies done for the discovery of new drug using different animal models for in vivo studies (chemical, surgical, and genetic models ) & in vitro models (glucose uptake, pancreatic islet cell lines and insulin secretion)
Prophylactic Effect of Butea monosperma against Cisplatin-Induced Nephrotoxicity in Rats
Cisplatin is an effective chemotherapeutic agent for solid tumors; however its use is limited by nephrotoxicity. The current study investigated the effect of Butea monosperma in cisplatin-induced nephrotoxicity and oxidative stress in rats. Kidneys have a vital role in the normal physiology of humans. Worldwide chronic kidney disease has become a major cause for disability and in worst circumstances leads to death. Major renal disorders occur due to diabetes and its complications termed as diabetic nephropathy (DN). The animals were divided into four groups of six rats each (n=6). The control group (Group 1) received 1%CMC, Group 2 received only cisplatin, a 7 days of extract of Butea monosperma (200 mg/kg bwt) pre-treatment was applied to the animals in Group 3 before administration of cisplatin; a 7 days of extract of Butea monosperma was performed following administration of cisplatin for the animals in Group 4. Cisplatin (6 mg/kg) was intraperitoneally injected as a single dose and extract of Butea monosperma (200 and 400 mg/kg bwt) was administered by gavage in 1%CMC. Biochemical and histopathological methods were utilized for evaluation of the nephrotoxicity. The concentrations of creatinine, uric acid and blood urine nitrogen, in plasma and levels of malondialdehyde and reduced glutathione as well as glutathione peroxidase and catalase activities were determined in kidney tissue. Administration of cisplatin to rats induced a marked renal failure, characterized with a significant increase in plasma creatinine and uric acid and Blood urea nitrogen. levels of rats received cisplatin alone were significantly different compared to control group but they had higher kidney malondialdehyde, and lower reduce glutathione concentrations, superoxide dismutase and catalase activities. Extract of B. monosperma administration produced amelioration in biochemical indices of nephrotoxicity in both serum and kidney tissues when compared to toxic inducer group; pre-treatment with extract of Butea monosperma being more effective. Results from this study indicated that the novel natural antioxidant extract of B. monosperma might have protective effect against cisplatin-induced nephrotoxicity and oxidative stress in rat.
 
Echocardiographic evaluation of left ventricular diastolic dysfunction in recently diagnosed type 2 diabetes mellitus
Background: Diastolic dysfunction in patients suffering from diabetes mellitus represents an earlier stage in the natural history of cardiomyopathy. This study was done to assess the left ventricular diastolic dysfunction in recently diagnosed (<5yr) Type 2 Diabetes Mellitus by Echocardiography and also to determine association of glycemic status (by HBA1c levels) with left ventricular diastolic dysfunction (LVDD).Methods: An observational descriptive study involving 100 diabetic patients, taken on first come first serve basis after applying inclusion and exclusion criteria. In all the subjects, other than routine investigations, HbA1c was estimated and echocardiography was done to evaluate LVDD.Results: Mean value of HbA1c in the study was 8.31+ 1.408 %. 63 out of 100 subjects had LVDD. There was significant positive correlation between HbA1c and LVDD (p value <0.001). As HbA1c increased, severity of LVDD increased. In this study, as BMI increased, HbA1c and LVDD increased & both findings were statistically significant (p value =0.001).Conclusion: Our study indicates that myocardial damage in patients with diabetes affects diastolic function before systolic function &higher HbA1C level is strongly associated with presence of LVDD. Patients should be advised strict control of diabetes in order to reduce the risk for developing LVDD which is a precursor for more advanced disease.Keywords: Diabetes mellitus, Diastolic dysfunction, BMI, HbA1
Listeria monocytogenes brain abscess in an immunocompromised patient: a case report
Listeria monocytogenes is a facultative intracellular gram-positive bacillus which usually infects immunocompromised patients, though it can infrequently infect immunocompetent individuals, neonates and pregnant women as well. Neurological manifestations include meningitis and cerebritis. Brain Abscess is an extremely rare presentation with approximately 80 reported cases. Authors report a patient with a brain abscess identified on an MRI scan with positive blood culture for Listeria monocytogenes. Patient was managed conservatively with intravenous followed by oral antibiotics with resolution of the abscess.
Chronic neutrophilic leukaemia-a rare haematological malignancy
Chronic neutrophilic leukaemia is a rare myeloproliferative neoplasm. It requires exhaustive workup and puts a diagnostic challenge to the clinician as well as pathologist. It should be differentiated from chronic myelogenous leukemia and reactive neutrophilia. Prognosis of the disease is poor. Here we report a case presented to us with 4 months of fatigue and fever. Investigation shows leucocytosis with predominant neutrophilia, evaluated and diagnosed as Chronic Neutrophilic Leukaemia (CNL) according to revised WHO criteria
Detection of Brain Injury Using Different Soft Computing Techniques: A Survey
The detection of brain injury is one of the important and difficult task in the field of medicine. If the brain injuries are not detected in time, then it can cause serious problems in patients and sometimes can even lead to death. Traumatic brain injury (TBI) is one of the major causes of mortality and poor quality of life among the survivors. Various imaging techniques are available for taking the images of the brain so that the injuries can be detected. Magnetic resonance imaging (MRI) is one of the common medical imaging technique used for the delineation of soft tissues such as that of the brain. This paper analyses few of the methods and their performances that have been proposed for the detection of the brain injury. In these methods different soft computing techniques such as artificial neural networks (ANN), k nearest neighbor (k-NN), support vector machine (SVM), Parzan window, etc. were used for the classification of abnormal and normal brain images. Before classification feature extraction and reduction were done using the methods such as DWT, GLCM, PCA, etc.
DOI: 10.17762/ijritcc2321-8169.15030
Decompressive craniectomy in herpes simplex encephalitis: a case report
Herpes Simplex Encephalitis is the commonest form of sporadic encephalitis. Availability of effective antiviral therapy viz Acyclovir has significantly reduced the mortality of Herpes Simplex Encephalitis. Elevated intracranial pressure resulting in herniation syndromes continues to be an important cause of mortality. Antiviral therapy and medical measures for managing raised intracranial pressure including osmotic diuretics, careful usage of steroids and controlled hyperventilation continue to be the cornerstones in management of these patients. Authors present a 38-year-old male patient with Cerebrospinal fluid Meningo-encephalitic panel positivity for herpes simplex virus 1 and bilateral temporal lobe lesions with secondary decline due to impending herniation syndrome despite osmotic diuretics and steroids with patient survival and complete recovery following decompressive hemicraniectomy
Cytomorphology of Castleman’s Disease of Parotid Gland: Pitfalls and Diagnostic Dilemma in a Young Adult
Fine needle aspiration cytology (FNAC) is an easy, effective diagnostic tool that makes it the procedure of choice for all accessible
swellings in the body. Castleman’s disease (CD) may present as unicentric or multicentric swelling hence is subjected to FNAC
very frequently. CD mainly presents mediastinal nodes, nonetheless when present in salivary glands such as parotid, it is often
diagnosed clinically as a salivary gland tumor. However, due to lack of adequate literature on its cytological features and nonspecific radiological findings, the condition is often misdiagnosed. There are few case series on cytological features of CD and even
fewer cases of CD in the parotid gland. Histopathology serves as the gold standard of diagnosis for CD. In superficial locations,
these swellings are easily subjected to direct fine needle aspiration cytology (FNAC). Radiologically guided FNA can be performed
for deeper locations. Hence, the authors present a case of 19 year old male patient, who presented with a small superficial,
preauricular swelling for FNAC. The initial FNAC yielded no conclusive opinion. however a repeat FNAC and histopathological
examination led to the final diagnosis. This case report aims to highlight the cytomorphological and histopathological features of
CD in the Parotid gland and various difficulties encountered in making the final diagnosi
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