15 research outputs found
Analysis of Various Data Mining Techniques using Novel Ratings Prediction
Availability of large amount of data in unprocessed form has increased the need of data mining. Various data mining techniques are available for this purpose but we need to choose one which is more accurate. Looking at the increasing interest of people in novel reading, data collected for prediction is based on novels. People were asked to rate different genre novel s. This study has predicted ratings of dystopian novel based on ratings given to other genre novels by readers using various data mining techniques and calculated their prediction accuracy
Site-Specific Effects of PECAM-1 on Atherosclerosis in LDL Receptor-Deficient Mice
Objective—Atherosclerosis is a vascular disease that involves lesion formation at sites of disturbed flow under the influence of genetic and environmental factors. Endothelial expression of adhesion molecules that enable infiltration of immune cells is important for lesion development. Platelet/endothelial cell adhesion molecule-1 (PECAM-1; CD31) is an adhesion and signaling receptor expressed by many cells involved in atherosclerotic lesion development. PECAM-1 transduces signals required for proinflammatory adhesion molecule expression at atherosusceptible sites; thus, it is predicted to be proatherosclerotic. PECAM-1 also inhibits inflammatory responses, on which basis it is predicted to be atheroprotective.
Methods and Results—We evaluated herein the effect of PECAM-1 deficiency on development of atherosclerosis in LDL receptor– deficient mice. We found that PECAM-1 has both proatherosclerotic and atheroprotective effects, but that the former dominate in the inner curvature of the aortic arch whereas the latter dominate in the aortic sinus, branching arteries, and descending aorta. Endothelial cell expression of PECAM-1 was sufficient for its atheroprotective effects in the aortic sinus but not in the descending aorta, where the atheroprotective effects of PECAM-1 also required its expression on bone marrow–derived cells.
Conclusion—We conclude that PECAM-1 influences initiation and progression of atherosclerosis both positively and negatively, and that it does so in a site-specific manner. (Arterioscler Thromb Vasc Biol. 2008;28:1996-2002
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Differences In Nicotine Dependence, Smoke Exposure And Consumer Characteristics Between Smokers Of Machine-Injected Roll-Your-Own Cigarettes And Factory-Made Cigarettes
Background: Consumption of machine-injected roll-your-own (RYO) filtered cigarettes made from pipe tobacco increased almost 7-fold from 2008 to 2011 in the United States. Methods: We used data from the Pennsylvania Adult Smoking Study to compare the differences in sociodemographic, smoking topography, nicotine dependence, and cotinine levels between 280 smokers using factory made (FM) cigarettes and 68 smokers using RYO cigarettes. Results: RYO smokers were older (41 vs. 37, P = 0.053), had significantly lower levels of income (P \u3c 0.001) and education (P = 0.007), and were less likely to be fully employed (P = 0.009). RYO smokers consumed more cigarettes per day [CPD] (21 vs. 15, P \u3c 0.001), and had a higher mean score on the Fagerström Test for Cigarette/Nicotine Dependence (5.2 vs. 4.1, P \u3c 0.001). The main reasons for choosing RYO cigarettes were the lower cost (68%) and believed they are less harmful (12%). The average cost per pack of FM cigarettes was 1.13 for RYO. In multiple regression analyses, RYO smokers had significantly lower cotinine levels across all levels of CPD. Among smokers of king-size cigarettes, mean interpuff interval (P \u3c 0.05) and total smoke duration (P \u3c 0.01) per cigarette was significantly greater in RYO smokers. In laboratory measurements, RYO cigarettes contained more tobacco by weight than FM cigarettes, but weight varied by both tobacco and cigarette tube brands. Conclusions: Machine-injected RYO cigarettes made from pipe tobacco are cheaper than FM cigarettes but may have higher abuse liability. Smokers who might otherwise reduce their cigarette consumption or quit altogether may continue to smoke RYO cigarettes due to their affordability
Platelet-Endothelial Cell Adhesion Molecule-1 Regulates Endothelial NO Synthase Activity and Localization Through Signal Transducers and Activators of Transcription 3–Dependent NOSTRIN Expression
Differences in nicotine dependence, smoke exposure and consumer characteristics between smokers of machine-injected roll-your-own cigarettes and factory-made cigarettes.
BACKGROUND: Consumption of machine-injected roll-your-own (RYO) filtered cigarettes made from pipe tobacco increased almost 7-fold from 2008 to 2011 in the United States.
METHODS: We used data from the Pennsylvania Adult Smoking Study to compare the differences in sociodemographic, smoking topography, nicotine dependence, and cotinine levels between 280 smokers using factory made (FM) cigarettes and 68 smokers using RYO cigarettes.
RESULTS: RYO smokers were older (41 vs. 37, P = 0.053), had significantly lower levels of income (P \u3c 0.001) and education (P = 0.007), and were less likely to be fully employed (P = 0.009). RYO smokers consumed more cigarettes per day [CPD] (21 vs. 15, P \u3c 0.001), and had a higher mean score on the Fagerström Test for Cigarette/Nicotine Dependence (5.2 vs. 4.1, P \u3c 0.001). The main reasons for choosing RYO cigarettes were the lower cost (68%) and believed they are less harmful (12%). The average cost per pack of FM cigarettes was 1.13 for RYO. In multiple regression analyses, RYO smokers had significantly lower cotinine levels across all levels of CPD. Among smokers of king-size cigarettes, mean interpuff interval (P \u3c 0.05) and total smoke duration (P \u3c 0.01) per cigarette was significantly greater in RYO smokers. In laboratory measurements, RYO cigarettes contained more tobacco by weight than FM cigarettes, but weight varied by both tobacco and cigarette tube brands.
CONCLUSIONS: Machine-injected RYO cigarettes made from pipe tobacco are cheaper than FM cigarettes but may have higher abuse liability. Smokers who might otherwise reduce their cigarette consumption or quit altogether may continue to smoke RYO cigarettes due to their affordability
Effects of Topography-Related Puff Parameters on Carbonyl Delivery in Mainstream Cigarette Smoke
Smoking topography
parameters differ substantially between individual
smokers and may lead to significant variation in tobacco smoke exposure
and risk for tobacco-caused diseases. However, to date, little is
known regarding the impact of individual puff parameters on the delivery
of many harmful smoke constituents including carbonyls. To examine
this, we determined the effect of altering individual puff parameters
on mainstream smoke carbonyl levels in machine-smoked reference cigarettes.
Carbonyls including formaldehyde, acetaldehyde, crotonaldehyde, propionaldehyde,
methyl ethyl ketone (MEK), acrolein, and acetone were determined in
cigarette smoke by HPLC after derivatization with 2,4-dinitrophenylhydrazine
(DNPH). Deliveries of all carbonyls were nearly two-fold greater when
cigarettes were smoked according to the more intense Health Canada
Intense (HCI) protocol compared to the International Organization
of Standardization (ISO) method, consistent with the two-fold difference
in total puff volume between methods (ISO: 280–315 mL; CI:
495–605 mL). When individual topography parameters were assessed,
changes in puff volume alone had the greatest effect on carbonyl delivery
as predicted with total carbonyls being strongly correlated with overall
puff volume (<i>r</i><sup>2</sup>: 0.52–0.99) regardless
of how the differences in volume were achieved. All seven of the carbonyls
examined showed a similar relationship with puff volume. Minor effects
on carbonyl levels were observed from vent blocking and changing the
interpuff interval, while effects of changing puff duration and peak
flow rate were minimal. Overall, these results highlight the importance
of considering topography, especially puff volume, when the toxicant
delivery and potential exposure smokers receive are assessed. The
lack of an impact of other behaviors, including puff intensity and
duration independent of volume, indicate that factors such as temperature
and peak flow rate may have minimal overall effects on carbonyl production
and delivery
Influence of Smoking Puff Parameters and Tobacco Varieties on Free Radicals Yields in Cigarette Mainstream Smoke
Cigarette smoke is
a major exogenous source of free radicals, and
the resulting oxidative stress is one of the major causes of smoking-caused
diseases. Yet, many of the factors that impact free radical delivery
from cigarettes remain unclear. In this study, we machine-smoked cigarettes
and measured the levels of gas- and particulate-phase radicals by
electron paramagnetic resonance (EPR) spectroscopy using standardized
smoking regimens (International Organization of Standardization (ISO)
and Canadian Intense (CI)), puffing parameters, and tobacco blends.
Radical delivery per cigarette was significantly greater in both gas
(4-fold) and particulate (6-fold) phases when cigarettes were smoked
under the CI protocol compared to the ISO protocol. Total puff volume
per cigarette was the major factor with radical production being proportional
to total volume, regardless of whether volume differences were achieved
by changes in individual puff volume or puff frequency. Changing puff
shape (bell vs sharp vs square) or puff duration (1–5 s), without
changing volume, had no effect on radical yields. Tobacco variety
did have a significant impact on free radical production, with gas-phase
radicals highest in reconstituted > burley > oriental > bright
tobacco
and particulate-phase radicals highest in burley > bright >
oriental
> reconstituted tobacco. Our findings show that modifiable cigarette
design features and measurable user smoking behaviors are key factors
determining free radical exposure in smokers