Feature selection for chemical sensor arrays using mutual information

We address the problem of feature selection for classifying a diverse set of chemicals using an array of metal oxide sensors. Our aim is to evaluate a filter approach to feature selection with reference to previous work, which used a wrapper approach on the same data set, and established best features and upper bounds on classification performance. We selected feature sets that exhibit the maximal mutual information with the identity of the chemicals. The selected features closely match those found to perform well in the previous study using a wrapper approach to conduct an exhaustive search of all permitted feature combinations. By comparing the classification performance of support vector machines (using features selected by mutual information) with the performance observed in the previous study, we found that while our approach does not always give the maximum possible classification performance, it always selects features that achieve classification performance approaching the optimum obtained by exhaustive search. We performed further classification using the selected feature set with some common classifiers and found that, for the selected features, Bayesian Networks gave the best performance. Finally, we compared the observed classification performances with the performance of classifiers using randomly selected features. We found that the selected features consistently outperformed randomly selected features for all tested classifiers. The mutual information filter approach is therefore a computationally efficient method for selecting near optimal features for chemical sensor arrays

Suitability of PSA-detected localised prostate cancers for focal therapy: Experience from the ProtecT study

This article is available through a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. Copyright @ 2011 Cancer Research UK.Background: Contemporary screening for prostate cancer frequently identifies small volume, low-grade lesions. Some clinicians have advocated focal prostatic ablation as an alternative to more aggressive interventions to manage these lesions. To identify which patients might benefit from focal ablative techniques, we analysed the surgical specimens of a large sample of population-detected men undergoing radical prostatectomy as part of a randomised clinical trial. Methods: Surgical specimens from 525 men who underwent prostatectomy within the ProtecT study were analysed to determine tumour volume, location and grade. These findings were compared with information available in the biopsy specimen to examine whether focal therapy could be provided appropriately. Results: Solitary cancers were found in prostatectomy specimens from 19% (100 out of 525) of men. In addition, 73 out of 425 (17%) men had multiple cancers with a solitary significant tumour focus. Thus, 173 out of 525 (33%) men had tumours potentially suitable for focal therapy. The majority of these were small, well-differentiated lesions that appeared to be pathologically insignificant (38–66%). Criteria used to select patients for focal prostatic ablation underestimated the cancer's significance in 26% (34 out of 130) of men and resulted in overtreatment in more than half. Only 18% (24 out of 130) of men presumed eligible for focal therapy, actually had significant solitary lesions. Conclusion: Focal therapy appears inappropriate for the majority of men presenting with prostate-specific antigen-detected localised prostate cancer. Unifocal prostate cancers suitable for focal ablation are difficult to identify pre-operatively using biopsy alone. Most lesions meeting criteria for focal ablation were either more aggressive than expected or posed little threat of progression.National Institute for Health Researc

Ambient levels of volatile organic compounds in the vicinity of petrochemical industrial area of Yokohama, Japan

Urban ambient air concentrations of 39 aromatic (including benzene, toluene, and xylenes) and aliphatic volatile organic compounds (VOCs) were measured in Yokohama city, Japan. Yokohama city was selected as a case study to assess the amount of VOC released from Industrial area to characterize the ambient air quality with respect to VOC as well as to know the impact of petrochemical storage facilities on local air quality. For this purpose, ambient air samples were collected (from June 2007 to November 2008) at six selected locations which are designated as industrial, residential, or commercial areas. To find out the diurnal variations of VOC, hourly nighttime sampling was carried out for three nights at one of the industrial locations (Shiohama). Samples were analyzed using gas chromatographic system (GC-FID). Results show strong variation between day and nighttime concentrations and among the seasons. Aliphatic fractions were most abundant, suggesting petrochemical storage facilities as the major source of atmospheric hydrocarbons. High concentrations of benzene, toluene, ethyl benzene, and xylene (BTEX) were observed at industrial locations. BTEX showed strong diurnal variation which is attributed to change in meteorology. During our campaign, low ambient VOC concentrations were observed at the residential site

Gnathic diagnosis

WOS: A1996UZ12600013PubMed ID: 871229

A current dilemma in histopathology: Atypical Spitz tumor or Spitzoid melanoma?

Both clinically and histopathologically, melanoma of childhood is a rarely encountered lesion. In addition, it has particular histopathologic diagnostic problems. Differential diagnosis of this lesion and Spitz nevus is at times very problematic, in that distant metastases and death of the patient may be the only diagnostic criteria for some cases. We present a 4-year-old girl with an atypical melanocytic neoplasm with Spitzoid features on the left subscapular region

Verumontanum mucosal gland hyperplasia is associated with atypical adenomatous hyperplasia of the prostate

Background.-Verumontanum mucosal gland hyperplasia (VMGH) and atypical adenomatous hyperplasia (AAH) are both small glandular proliferations that are histologically and topographically unique

N-acetylcysteine attenuates bacterial translocation after partial hepatectomy in rats.

Background. Translocating enteric bacteria have been suggested as playing a major role in the development of infections after partial hepatectomy. We investigated the effect of N-acetylcysteine (NAC) on bacterial translocation. (BT) and intestinal mucosa as the first line of defense against BT

The effect of SWL and URS on health-related quality of life in proximal ureteral stones.

OBJECTIVES: We aimed to compare the effect of shock wave lithotripsy (SWL) and ureteroscopic lithotripsy (URS) on health-related quality of life (HRQoL) for the treatment of proximal ureteral stones. MATERIAL AND METHODS: Between April 2014 and July 2015, patients with proximal ureteral stones who were successfully treated with URS or SWL in seven different centers were included. Patients were divided into two groups according to stone size: stones ≤10 mm and >10 mm. HRQoL subscales which were evaluated by the Medical Outcome Study Short-Form 36-item survey (SF-36) Turkish version were compared for URS and SWL in these two groups one month after the performed procedure. RESULTS: A total of 273 patients were included in the study. While 116 (52.5%) patients were treated with ureteroscopic lithotripsy, SWL was used for 105 (47.5%) patients. Fifty-two patients were excluded from the study. In proximal ureteral stones ≤10 mm, there were no statistically significant differences for any of the eight subscales of the SF-36 questionnaire. Regarding stones >10 mm, it was found that the three subscales of the SF-36 questionnaire - role limitations because of physical health problems (RP), bodily pain (BP), and general health perception (GH) - were significantly lower in the SWL group compared with the URS group. CONCLUSIONS: Patients with proximal ureteral stones >10 mm who were treated with URS generally may have a more favorable HRQoL than those treated with SWL in short-term follow-up