Providing Diversity in K-Nearest Neighbor Query Results

Given a point query Q in multi-dimensional space, K-Nearest Neighbor (KNN) queries return the K closest answers according to given distance metric in the database with respect to Q. In this scenario, it is possible that a majority of the answers may be very similar to some other, especially when the data has clusters. For a variety of applications, such homogeneous result sets may not add value to the user. In this paper, we consider the problem of providing diversity in the results of KNN queries, that is, to produce the closest result set such that each answer is sufficiently different from the rest. We first propose a user-tunable definition of diversity, and then present an algorithm, called MOTLEY, for producing a diverse result set as per this definition. Through a detailed experimental evaluation on real and synthetic data, we show that MOTLEY can produce diverse result sets by reading only a small fraction of the tuples in the database. Further, it imposes no additional overhead on the evaluation of traditional KNN queries, thereby providing a seamless interface between diversity and distance.Comment: 20 pages, 11 figure

Assessment of cardiac complication in diabetic patient of rural India

Background: Diabetes mellitus (DM) is a common endocrine disorder affecting approximately 382 million people worldwide. Diabetes mellitus (DM) is group of metabolic disorder in which glucose is underutilized, thus producing hyperglycemia resulting from a defect in insulin secretion, action, or both. Cardiovascular disease is the most common cause of death and disability among people with diabetes. The cardiovascular disease that accompany diabetes include angina, myocardial infarction (heart attack), Stroke, peripheral artery disease and congestive heart failure. In people with diabetes, high blood pressure, high cholesterol, high blood glucose and other risk factors contribute to the increased risk of cardiovascular complications.Method:  This study was conducted to determine the cardiac complication in diabetic patient of rural India. It was Cross sectional retrospective study, done in between period of January 2018 to December 2019.Result: In the present study authors found that   47.7% patients have Coronary artery disease (CAD), Silent 21.6% have myocardial ischemia (SMI), 36% Diastolic dysfunction (DF), 28.8% have Systolic dysfunction (SDF).Conclusion: In this study authors found that wide spectrum of cardiac complications in diabetic patients ranging silent myocardial ischemia to heart failure. CAD was the most common complication including silent myocardial ischemia (SMI) which is the one of the major concern of rural diabetic population which need proper screening by exercise treadmill test

Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July–August 2001: a multi-analytical approach

International audienceDuring the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T>550ºC) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) mass concentrations were on average respectively 1.19±0.56 and 3.62±1.08 mgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 mgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope=1.00, r2=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these two methods for determining BC brings here new insights on the origin of carbonaceous aerosols in a complex mixture of different sources. It brings also to our attention that important deviations in BC levels are observed using three widely used EGA's techniques and most probably none of the EGA tested here are well adapted to fully characterize this aerosol mixture. Spherical, smooth and silico-aluminated fly-ash observed by an Analytical Scanning Electron Microscope (ASEM) confirm the influence of coal combustion on the carbonaceous aerosol load throughout the campaign. A rough calculation based on a BC/nss-SO4 mass ratio suggests that biomass burning could be responsible for half of the BC concentration recorded during the MINOS campaign. From the plot of BC as a function of TC, two linear correlations were observed corresponding to 2 times series (before and after 12 August). Such good correlations suggest, from a first look, that both BC and OC have similar origin and atmospheric transport. On the other hand, the plot of BC as a function of TC obtained from the 2-step thermal method applied to DEKATI Low Pressure Cascade Impactor samples does not show a similar correlation and points out a non conservative distribution of this ratio with 2 super micron modes enriched in OC, correlated with sea salt aerosols and probably originating from gas-to-particle conversion

Variability of dimethyl sulphide (DMS), methanethiol and other trace gases in relation with microbial communities from the temperate Atlantic to the Arctic Ocean

Dimethyl sulphide (DMS) plays an important role in the atmosphere by influencing the formation of aerosols and cloud condensation nuclei. In contrast, the role of methanethiol (MeSH) for the budget and flux of reduced sulphur remains poorly understood. In the present study, we quantified DMS and MeSH together with the trace gases carbon monoxide (CO), isoprene, acetone, acetaldehyde and acetonitrile in North Atlantic and Arctic Ocean surface waters, covering a transect from 57.2° N to 80.9° N in high spatial resolution. Whereas isoprene, acetone, acetaldehyde and acetonitrile concentrations decreased northwards, CO, DMS and MeSH retained significant levels at high latitudes, indicating specific sources in polar waters. DMS was the only compound with higher average in polar (31.2 ± 9.3 nM) than in Atlantic waters (13.5 ± 2 nM), presumably due to DMS originating from sea ice. At eight sea-ice stations north of 80° N, in the diatom-dominated marginal ice zone, vertical profiles showed a marked correlation (R2 = 0.93) between DMS and chlorophyll a. Contrary to previous measurements, MeSH and DMS did not co-vary, indicating decoupled processes of production and conversion. The contribution of MeSH to the sulphur budget (represented by DMS+MeSH) was on average 20 % (and up to 50 %) higher than previously observed in the Atlantic and Pacific Oceans, suggesting MeSH as a significant source of sulphur possibly emitted to the atmosphere. The potential importance of MeSH was underlined by several correlations with bacterial taxa, including typical phytoplankton associates from the Rhodobacteraceae and Flavobacteriaceae families. Furthermore, the correlation of isoprene and chlorophyll a with Alcanivorax indicated a specific relationship with isoprene-producing phytoplankton. Overall, the demonstrated latitudinal and vertical patterns contribute to the understanding of central marine trace gases from chemical, atmospheric and biological perspectives

Role of acute viral hepatitis as a confounding factor in antituberculosis treatment induced hepatotoxicity

Background & Objective: Drug induced hepatotoxicity (DIH) is an important and commonly encountered adverse effect with antituberculosis (anti-TB) treatment. Acute viral hepatitis (AVH) is an important confounding reason which clinically, biochemically and histologically mimics DIH. Methods: The contributory role of acute viral hepatitis as a confounding factor in patients with normal baseline liver functions who developed acute hepatitis while receiving short-course anti-TB treatment was prospectively studied. The sera of all patients who developed acute hepatitis were analysed for markers for hepatitis A, B, C and E viruses. Results: Viral hepatitis was present in 15 of the 102 (14.7%) patients who developed acute hepatitis while receiving anti-TB treatment with hepatitis E virus being the most common cause Later onset of acute hepatitis [58 (5-133) vs. 26 (3-221) days; P=0.04], large elevations in aspartate aminotransferase (AST) [371 (30-2643) vs. 212 (63-1990 IU/l); P=0.03] and alanine aminotransferase (ALT) [388 (31-2997) vs. 225 (52- 1670 IU/l); P= 0.002] and a longer time for normalization of deranged liver functions [36.7 ± 13.3 vs. 24.5 ± 19.3 days; P=0.02] indicated acute viral hepatitis as the cause of liver function derangement. Interpretation & Conclusion: Our findings showed AVH in 14.7 per cent patients who developed hepatotoxicity while an anti-TB treatment. Therefore, in endemic areas, viral hepatitis should be sought after and excluded in all patients suspected to have DIH before attributing the hepatotoxic effect to the anti-TB drugs

Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July–August 2001: a multi-analytical approach

During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T>550ºC) under the pure helium step of the analysis.<br> <br> During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) mass concentrations were on average respectively 1.19±0.56 and 3.62±1.08 <font face='Symbol'>m</font>gC/m³ for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 <font face='Symbol'>m</font>gC/m³ for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope=1.00, <i>r</i>²=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO₄), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these two methods for determining BC brings here new insights on the origin of carbonaceous aerosols in a complex mixture of different sources. It brings also to our attention that important deviations in BC levels are observed using three widely used EGA's techniques and most probably none of the EGA tested here are well adapted to fully characterize this aerosol mixture.<br> <br> Spherical, smooth and silico-aluminated fly-ash observed by an Analytical Scanning Electron Microscope (ASEM) confirm the influence of coal combustion on the carbonaceous aerosol load throughout the campaign. A rough calculation based on a BC/nss-SO₄ mass ratio suggests that biomass burning could be responsible for half of the BC concentration recorded during the MINOS campaign.<br> <br> From the plot of BC as a function of TC, two linear correlations were observed corresponding to 2 times series (before and after 12 August). Such good correlations suggest, from a first look, that both BC and OC have similar origin and atmospheric transport. On the other hand, the plot of BC as a function of TC obtained from the 2-step thermal method applied to DEKATI Low Pressure Cascade Impactor samples does not show a similar correlation and points out a non conservative distribution of this ratio with 2 super micron modes enriched in OC, correlated with sea salt aerosols and probably originating from gas-to-particle conversion

Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions

Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D. &lt;2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM&lt;sub&gt;2.5&lt;/sub&gt;). This time-resolved dataset allowed investigating the factors controlling the levels of PM&lt;sub&gt;2.5&lt;/sub&gt; in Paris and showed that polluted periods with PM&lt;sub&gt;2.5&lt;/sub&gt; &gt; 15 μg m&lt;sup&gt;−3&lt;/sup&gt; were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations (typically of about 10 μg m&lt;sup&gt;−3&lt;/sup&gt;); carbonaceous aerosols contributing for most of this mass (typically 75%). &lt;br&gt;&lt;br&gt; In order to better discriminate between local and continental contributions to the observed chemical composition and concentrations of PM&lt;sub&gt;2.5&lt;/sub&gt; over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM&lt;sub&gt;2.5&lt;/sub&gt; and ion species. Different model scenarios were then investigated switching off local and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. On the opposite, long-range transport from Europe appeared to weakly contribute to the levels of carbonaceous aerosols observed over Paris. &lt;br&gt;&lt;br&gt; The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as much as 75%, showing a weak dependence on air masses origin. Elevated SOA/OA ratios were also observed for air masses having residence time above ground of less than 10 h, suggesting intense emissions and/or photochemical processes leading to rapid formation of secondary organic aerosols

Microwave Assisted Synthesis of 2,4-Diphenyl-4H-chromen-5-one Using ZnCl2/Montmorillonite K-10

α, β-Unsaturated carbonyl compounds and 1, 3-cyclohexanedione under microwave irradiation in the presence ZnCl2/montmorillonite K-10 offers the corresponding 2,4-diphenyl-4H-chromen-5-one in excellent yield. Catalyst is recycled and reused for several time