On Estimating the First Frequency Moment of Data Streams

Estimating the first moment of a data stream defined as F_1 = \sum_{i \in \{1, 2, \ldots, n\}} \abs{f_i} to within $1 \pm \epsilon$-relative error with high probability is a basic and influential problem in data stream processing. A tight space bound of $O(\epsilon^{-2} \log (mM))$ is known from the work of [Kane-Nelson-Woodruff-SODA10]. However, all known algorithms for this problem require per-update stream processing time of $\Omega(\epsilon^{-2})$, with the only exception being the algorithm of [Ganguly-Cormode-RANDOM07] that requires per-update processing time of $O(\log^2(mM)(\log n))$ albeit with sub-optimal space $O(\epsilon^{-3}\log^2(mM))$. In this paper, we present an algorithm for estimating $F_1$ that achieves near-optimality in both space and update processing time. The space requirement is $O(\epsilon^{-2}(\log n + (\log \epsilon^{-1})\log(mM)))$ and the per-update processing time is $O( (\log n)\log (\epsilon^{-1}))$.Comment: 12 page

Cardioprotective Roles of Hydrogen Sulfide Donor Treatment in Diabetic Cardiomyopathy

Diabetes mellitus (DM) increases the risk of heart failure 2-4-fold. Intensive glycemic control does not abate this risk in DM patients, suggesting that DM-induced heart failure is beyond hyperglycemia. DM silently induces cardiac muscle disorder termed diabetic cardiomyopathy (DMCM), which progresses to heart failure. The objective of this dissertation is to understand the mechanistic underpinnings of DMCM to develop new solutions to diagnose and treat heart failure in DM. The heart pumps blood due to the contraction and relaxation of terminally differentiated cardiomyocytes with limited regenerative capacity. The DM environment of hyperglycemia, hyperlipidemia, and inflammation causes cardiomyocyte death and leads to hypertrophy, fibrosis, and heart failure progression. Apoptosis, the most studied form of cell death, contributes minimally (0.025%) to cardiomyocyte death in the failing heart. Thus, non-apoptotic forms of cell death predominate, but their molecular mechanisms are unclear in the DM heart. Pyroptosis is an inflammatory non-apoptotic cell death pathway shown to occur in cardiomyopathies. Ferroptosis is a newly discovered form of cell death, which is triggered by the accumulation of intracellular iron, lipids, and oxidative stress. Although inflammation, lipotoxicity, iron overload, and oxidative stress are hallmarks of DMCM, the role of cardiac pyroptosis and ferroptosis in DMCM remains unclear. Hydrogen sulfide (H₂S) is a gaseous signaling molecule that has been shown to inhibit multiple forms of cell death. Systemic and cardiac levels of H₂S are reduced in DM. We hypothesized that DM induces non-apoptotic cell death which may be prevented by elevating endogenous H₂S. We also investigated if exercise training has cardioprotective effects in DMCM via H₂S upregulation. Our results demonstrated that reduced expression of H₂S biosynthesis enzymes increased pyroptosis and caused cardiac remodeling. DM hearts also demonstrated increased pyroptosis and ferroptosis. H₂S donor treatment or exercise training increased cardiac H₂S levels, inhibited pyroptosis and ferroptosis signaling, and prevented adverse cardiac remodeling and dysfunction. Our studies demonstrate how myocardial cell death contributes to DMCM progression. We conclude that targeting cell death, specifically by H₂S donor treatment and/or exercise, could be a novel approach to mitigate DMCM and heart failure

Black Hole Geometries in Noncommutative String Theory

We obtain a generalized Schwarzschild (GS-) and a generalized Reissner-Nordstrom (GRN-) black hole geometries in (3+1)-dimensions, in a noncommutative string theory. In particular, we consider an effective theory of gravity on a curved $D_3$-brane in presence of an electromagnetic (EM-) field. Two different length scales, inherent in its noncommutative counter-part, are exploited to obtain a theory of effective gravity coupled to an U(1) noncommutative gauge theory to all orders in $\Theta$. It is shown that the GRN-black hole geometry, in the Planckian regime, reduces to the GS-black hole. However in the classical regime it may be seen to govern both Reissner-Nordstrom and Schwarzschild geometries independently. The emerging notion of 2D black holes evident in the frame-work are analyzed. It is argued that the $D$-string in the theory may be described by the near horizon 2D black hole geometry, in the gravity decoupling limit. Finally, our analysis explains the nature of the effective force derived from the nonlinear EM-field and accounts for the Hawking radiation phenomenon in the formalism.Comment: 30 pages, 2 figure

An Anomaly Detection Scheme for DDoS Attack in Grid Computing

The demand for computing power and storage is increasing continuously and there are applications like scientific research and industrial need, whose computational demand even exceeds the available fastest technologies. As a result it is an economically feasible mean to look into efficiently aggregate existing distributed resources. To achieving this goal makes it possible to build a shared large scale wide-area distributed computing infrastructure, a concept which has been named the Grid computing. The primary objective of Grid computing is to support the sharing of resources and service spanning across multiple administrative domains. Due to the inherently dynamic and multi organizational nature maintaining security of both users and resources is the challenging aspect of Grid. Grid uses internet as an infrastructure to build communication, with the fusion of web services and grid technologies further increases the security concerns for their complex nature. This thesis takes a look at the vulnerability of Grid environment on denial of service attack. We found that deploying an efficient intrusion detection system to Grid can significantly improve its security and it can detect denial of service attack before it affects the victim. But due to the special characteristics and requirement of Grids, the existing traditional intrusion detection system can not work properly in that environment. The focus of this thesis is to investigate and design an anomaly detection system which can detect DoS and DDoS attack with high attack detection and low false alarm rate to achieve high performance. We have extensively surveyed the current literatures in this area; the main stress is put on feature selection for the Grid based anomaly detection system. An entropy based anomaly detection system has been proposed; also we have discussed the advantage of taking entropy as the metric. Finally the performance of the system has been analyzed using NS2 network simulator. For shake of continuity each chapter has its relevant introduction and theory. The work is also supported by list of necessary references. Attempt is made to make the thesis self-content

Digito-palmar dermatoglyphics in vitiligo – A case control study

AbstractBackgroundDermatoglyphics is a scientific study of epidermal ridges and their configuration on the volar skin. It is not established whether there is definite dermatoglyphic pattern which exists with vitiligo.ObjectivesTo study the finger and palmar dermatoglyphic patterns in vitiligo patients.MethodsThe study included a total 112 cases of vitiligo and 104 controls. Handprints of palmar surface and rolled fingerprints of 10 digits were subjected to detailed digito-palmar dermatoglyphic analysis.ResultsMale patients had increased percentage of total loops, total ulnar loops and finger ridge counts and increased true palmar patterns (TPP) in right hypothenar, right thenar and both interdigital area (ID)2. Decreased percentage of total radial loops, total whorls, total arches, TPP in right ID3, right ID4 and absolute finger ridge count was noted in male patients. Female cases showed an increased number of arches, true palmar pattern in right hypo- thenar, right ID1 and a-b ridge count along with decreased number of total loops, total ulnar loops, total radial loops, whorls, total finger ridge count, absolute finger ridge count, TPP in right ID2 and left ID3. In both the sexes, atd angle was found to be increased

Scrotal Dermatitis - Can we Consider it as a Separate Entity?

Scrotal dermatitis is a very common condition that has been easily overlooked by most dermatologists and treating physicians. The condition is easily mistaken for the common skin disorders affecting the area, like fungal infections. Scrotal dermatitis is not considered a separate disease entity and is usually considered a condition similar to the contact dermatitis occurring elsewhere. This article attempts to classify the condition as a separate disease entity and explains the various etiological factors and the pathogenesis of the condition. The various stages of the condition are also explained in detail. Newer treatment modalities like the use of narrow band UVB for the management of scrotal dermatitis is also highlighted in this article

Microalbuminuria as an overrated indicator of target organ damage in hypertension: a hospital based cross sectional study

Background:Hypertension is one of the leading causes of global burden of disease. Uncontrolled hypertension is associated with long term risk of damage to vital organs like brain, heart, kidney, blood vessels and eye i.e. Target Organ Damage (TOD). Medical scientists all over the world have been in search for an indicator which can accurately predict TOD. It is accepted that Microalbuminuria (MA) represents a more generalised vascular problem, not only confined to renal microcirculation. MA is found in a significant proportion of non-diabetic population, particularly in association with hypertension and is a predictor of cardiovascular disease. The objective of the study was to evaluate MA in hypertension and its correlation with TOD.  Methods:A Hospital based cross sectional study carried out in the department medicine of central referral hospital, a well-equipped tertiary care hospital in East Sikkim, Gangtok. 200 patients were recruited fulfilling the inclusion criteria of pre hypertension, stage 1 & 2 hypertension as defined by JNC 7 report. Patients with secondary hypertension, DM, ESRD & hyperuricemia were excluded.  MA was estimated by Immunoturbidimetry.Results:MA is associated with all TOD but significant correlation was found only with retinopathy. Out of 200 study subjects, 90 (45%) subjects had retinopathy out of which 54 (60%) had MA and 36 (40%) did not have MA. (P <0.0001)Conclusion:MA has established its position in DM where it indicates early end organ damage and heralds cardiovascular risk. Its role as a reliable indicator of TOD in non-diabetic hypertensives needs further evaluation.

Adverse Events Following COVID-19 Vaccination among the Beneficiaries of Sikkim Manipal University: A Cross Sectional Study

Background: Covid-19, an infection caused by SARS- CoV2 has claimed millions of lives since late 2019 with no curative measures. In India, 4 vaccines have been approved for use i.e. Serum Institute’s Covishield, Bharat Biotech’s Covaxin, GRIEM’s Sputnik V and Moderna’s Covid-19 vaccine. Aims: This study aims to find the adverse events following Covishield vaccination among the beneficiaries of Sikkim Manipal University, Sikkim. Material &amp;Methods: A cross sectional study was conducted among the beneficiaries of Sikkim Manipal University to find out the adverse events following the first dose of vaccination. The data was collected using a self-administered questionnaire when the beneficiaries came for their second dose of vaccination. Microsoft Excel and SPSS version 27 was used for statistical analysis. Results: Out of 716 study participants majority i.e. 79.5% of the study participants developed adverse events following their first dose with maximum (73.8%) complaining of pain at the site of infection followed by fever (65.2%). Conclusions: Vaccines may prevent diseases, but it also brings about adverse effects, be it minor or major. Hence, many studies are required to study their full-fledged side effects and the means to overcome them

MMP9 mediates acute hyperglycemia-induced human cardiac stem cell death by upregulating apoptosis and pyroptosis in vitro

Providing a conducive microenvironment is critical to increase survival of transplanted stem cells in regenerative therapy. Hyperglycemia promotes stem cell death impairing cardiac regeneration in the diabetic heart. Understanding the molecular mechanisms of high glucose-induced stem cell death is important for improving cardiac regeneration in diabetic patients. Matrix metalloproteinase-9 (MMP9), a collagenase, is upregulated in the diabetic heart, and ablation of MMP9 decreases infarct size in the non-diabetic myocardial infarction heart. In the present study, we aim to investigate whether MMP9 is a mediator of hyperglycemia-induced cell death in human cardiac stem cells (hCSCs) in vitro. We created MMP9−/− hCSCs to test the hypothesis that MMP9 mediates hyperglycemia-induced oxidative stress and cell death via apoptosis and pyroptosis in hCSCs, which is attenuated by the lack of MMP9. We found that hyperglycemia induced oxidative stress and increased cell death by promoting pyroptosis and apoptosis in hCSCs, which was prevented in MMP9−/− hCSCs. These findings revealed a novel intracellular role of MMP9 in mediating stem cell death and provide a platform to assess whether MMP9 inhibition could improve hCSCs survival in stem cell therapy at least in acute hyperglycemic microenvironment