Non-heurisitc Machine Learning Apprach for Classifying Twitter Content

In online social networks like Twitter, the users usually get inundated with the continuous stream of short messages or tweets. This problem can be handled using classification. Classification is a supervised data mining technique which involves assigning a label to a set of unlabeled objects. A conventional approach for classifying text or tweets is to extract features from the linguistic content posted by the users. A recurrent problem in classification is feature selection, that is, to decide the best set of features for making a particular classification decision among the infinite possible different sets of features. This process usually involves heuristic approaches that require manual feature selection by experts, which involves guesswork, prior information about the dataset and a great deal of tweaking and experimental validation. To address this problem we propose and employ a non-heuristic machine learning approach which will automatically decide the feature set for a classification task. Our analysis shows that our automated feature selection process for Twitter content classification performs on par with current state-of-the-art approaches which incorporate painstaking, time-consuming human effort to manually and heuristically select a feature set. This approach will improve the timeliness and accessibility of data mining social media data streams.Computer Scienc

Venous Air Embolism during Surgery, Especially Cesarean Delivery

Venous air embolism (VAE) is the entrapment of air or medical gases into the venous system causing symptoms and signs of pulmonary vessel obstruction. The incidence of VAE during cesarean delivery ranges from 10 to 97% depending on surgical position or diagnostic tools, with a potential for life-threatening events. We reviewed extensive literatures regarding VAE in detail and herein described VAE during surgery including cesarean delivery from background and history to treatment and prevention. It is intended that present work will improve the understanding of VAE during surgery

A concise conceptual model for material data and its applications in process engineering

BACKGROUND: During caesarean section mothers can be in different positions. Theatre tables could be tilted laterally, upwards, downwards or flexed and wedges or cushions could be used. There is no consensus on the best positioning at present. OBJECTIVES: We assessed all available data on positioning of the mother to determine if there is an ideal position during caesarean section that would improve outcomes. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (September 2009), PubMed (1966 to 14 September 2009) and manually searched the references of retrieved articles. SELECTION CRITERIA: Randomised trials of woman undergoing caesarean section comparing different positions. DATA COLLECTION AND ANALYSIS: Two authors assessed eligibility, trial quality and extracted data. MAIN RESULTS: We identified 17 studies with a total of 683 woman included. We included nine studies and excluded eight studies. Included trials were of variably quality with small sample sizes. Most comparisons had data from single trials. This is a shortcoming and applicability of results is limited.The incidence of air embolism was not affected by head up versus horizontal position (risk ratio (RR) 0.91; 95% confidence interval (CI) 0.65 to 1.26). We found no change in hypotensive episodes when comparing left lateral tilt (RR 0.11; 95% CI 0.01 to 1.94), right lateral tilt (RR 1.25; 95% CI 0.39 to 3.99) and head down tilt (mean difference (MD) -3.00; 95% CI -8.38 to 2.38) with horizontal positions or full lateral tilt with 15-degree tilt (RR 1.20; 95% CI 0.80 to 1.79). Hypotensive episodes were decreased with manual displacers (RR 0.11; 95% CI 0.03 to 0.45), a right lumbar wedge compared to a right pelvic wedge (RR 1.64; 95% CI 1.07 to 2.53) and increased in right lateral tilt (RR 3.30; 95% CI 1.20 to 9.08) versus left lateral tilt.Position did not affect systolic blood pressure when comparing left lateral tilt (MD 2.70; 95% CI -1.47 to 6.87) or head down tilt (RR 1.07; 95% CI 0.81 to 1.42) to horizontal positions, or full lateral tilt with 15-degree tilt (MD -5.00; 95% CI -11.45 to 1.45). Manual displacers showed decreased fall in mean systolic blood pressure compared to left lateral tilt (MD -8.80; 95% CI -13.08 to -4.52).Position did not affect diastolic blood pressures when comparing left lateral tilt versus horizontal positions. (MD-1.90; 95% CI -5.28 to 1.48). The mean diastolic pressure was lower in head down tilt (MD -7.00; 95% CI -12.05 to -1.95) when compared to horizontal positions.There were no statistically significant changes in maternal pulse rate, five-minute Apgars, maternal blood pH or cord blood pH when comparing different positions. AUTHORS' CONCLUSIONS: There is limited evidence to support or clearly disprove the value of the use of tilting or flexing the table, the use of wedges and cushions or the use of mechanical displacers. Larger studies are needed.Revie