Objective: To investigate variations in the prevalence of self reported symptoms, diagnosis, and treatment of asthma in 12-14 year old children. Design: Self completion questionnaire. Setting: Great Britain.

Background-Respiratory diseases are common in childhood and may lead to chronic disease in adult life; environmental factors probably play an important part in their causation. Methods-A survey of respiratory symptoms in children aged 12-14 years was conducted throughout Great Britain as part of the International Study of Asthma and Allergies in Childhood (ISAAC). Information was obtained on certain aspects of the home environment in order to assess their importance as risk factors. Results-The response rate was 79.3%, and 25 393 children in 93 schools participated. In a multiple regression analysis, wheeze was reported more often in nonmetropolitan areas and in association with active smoking, passive smoking, the presence of a furry pet, bottled gas, paraffin, and other unusual heating fuels; small regional diVerences persisted. Current smoking, previous smoking, and passive smoking accounted for 10.4%, 6.8%, and 6.5%, respectively, of wheezing in the past 12 months, and furry pets accounted for 5.0%. Cough and phlegm were associated with active and passive smoking and with the miscellaneous fuels; similar associations were found for rhinitis, but were less consistent for rhinitis occurring in spring and summer. Gas cooking showed little association with respiratory symptoms. Conclusions-Passive as well as active smoking is an important cause of respiratory symptoms in adolescence. Pets seem to increase the risk of wheeze and rhinitis, and fumes from certain unusual heating fuels may have adverse eVects. Home environment and geographical location have independent eVects on the prevalence of respiratory symptoms.

Objectives-To describe the prevalence of atopic symptoms in children throughout the UK. Method-A questionnaire survey of 12-14 year olds throughout England, Wales, Scotland, and the Scottish Islands using the international study of asthma and allergies in childhood (ISAAC) protocol. Results-A total of 27 507 (86%) children took part. Recent rhinoconjunctivitis was reported by 18.2%, with 6.2% reporting symptoms between March and September; 16.4% reported itchy flexural rash in the past 12 months. The prevalence of atopic symptoms was higher in girls and subjects born within the UK. The prevalence of severe wheeze was highest in subjects reporting perennial rhinoconjunctivitis, as opposed to summertime only symptoms. Winter rhinoconjunctivitis was associated with severe wheeze and severe flexural rash. One or more current symptoms were reported by 47.6% of all children and 4% reported all three symptoms. Conclusion-In general, geographical variations were small but the prevalence of symptoms was significantly higher in Scotland and northern England. The study demonstrates the importance of atopic diseases both in their own right and in association with asthma. (Arch Dis Child 1999;81:225-230) Keywords: international study of asthma and allergies in childhood; hay fever; eczema; epidemiology; atopic diseaseThe prevalence of childhood hay fever shows wide variation throughout the world, ranging from 1.4% to 39.7%.1 The literature suggests that the prevalence of atopy has increased throughout the UK over the past five decades. In terms of eczema, the national British birth cohort study showed a rise in prevalence from 5.1% in 6 year olds born in 1946 to 12.2% for children born in 1970 and assessed at 5 years of age, 2 whereas data from the Welsh study of 12 year olds by Burr et al showed a rise from 5% in 1973 to 16% in 1988. 3 Similarly, the prevalence of hay fever in the same Welsh study rose from 9% to 15% over the 15 year period, whereas for Scottish children Russell reported a rise over a 25 year period from 3.2% in 1964 to 12.7% in 1994. 4 5 Ross and Fleming examined general practice data, which showed that the prevalence of hay fever was maximal in the age group 5-14 years and did not show any significant diVerences in geographical distribution throughout England or Wales. 6 Prevalence studies in diVerent geographical areas are often diYcult to compare because of variations in methodology. In addition, the term atopy, meaning a predisposition to develop type I hypersensitivity demonstrated by skin prick testing and assay of IgE, is often used in relation to atopic diseases such as hay fever and eczema. Many of these diYculties have been overcome by the protocol developed for the international study of asthma and allergies in childhood (ISAAC), which standardises both methodology and terminology. The distribution of hay fever and eczema are of interest not only in their own right, but also as an indicator of the pattern of atopy, which contributes to the burden of asthma. The literature demons...

Phenotypic and genetic diversity of 59 Macrophomina phaseolina isolates collected from various host species growing in or near cluster bean (Cyamopsis tetragonoloba) fields in four states of north and north‐west India were characterized using RAPD and PCR–RFLPs of the ITS region. These isolates, and 11 from various hosts from culture collections, were classified into three mycelial phenotypes: dense, feathery and restricted, based on variable growth patterns on nutrient agar containing 120 mm chlorate. Pathogenicity of isolates was evaluated by measuring the length of stem lesions 21 days post‐inoculation on the susceptible cluster bean genotype FS 277. Isolates showed considerable variation in aggressiveness, with the isolates from cluster bean with dense chlorate phenotype producing relatively higher lesion lengths on cluster bean plants. The results of the RAPD assay clearly distinguished the isolates on the basis of chlorate phenotype and host origin. Isolates from a single host were generally similar to each other, but differed distinctly from those from other hosts. Chlorate‐sensitive isolates were distinct from chlorate‐resistant isolates within a given host. A high degree of polymorphism in restriction patterns of the ITS region, including part of 25S rDNA, has been reported for the first time in the charcoal rot fungus.

The polycyclic aromatic hydrocarbon, benzo[a]pyrene (B[a]P) is a proven animal carcinogen that is potentially carcinogenic to humans. B[a]P is an ubiquitous environmental pollutant and is also present in tobacco smoke, coal tar, automobile exhaust emissions, and charred food. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using electrospray ionization and selected reaction monitoring (SRM) has been developed for the detection of 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]PDE-N(2)dG) adducts formed in DNA following the metabolic activation of B[a]P to benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (B[a]PDE). The method involves enzymatic digestion of the DNA sample to 2'-deoxynucleosides following the addition of a stable isotope internal standard, [(15)N(5)]B[a]PDE-N(2)dG, and then solid phase extraction to remove unmodified 2'-deoxynucleosides prior to analysis by LC-MS/MS SRM. The limit of detection of the method was 10 fmol (approximately 3 B[a]PDE-N(2)dG adducts per 10(8) 2'-deoxynucleosides) using 100 microg of calf thymus DNA as the matrix. Calf thymus DNA reacted with B[a]PDE in vitro and mouse liver DNA samples at different time points following dosing intraperitoneally with 50, 100, and 200 mg/kg B[a]P was analyzed. Three stereoisomers of the B[a]PDE-N(2)dG adduct were detected following the reaction of calf thymus DNA with B[a]PDE in vitro. The levels of B[a]PDE-N(2)dG DNA adducts in the mice livers were found to increase in a dose-dependent manner with adducts reaching maximal levels at 1-3 days and then gradually decreasing over time but still detectable after 28 days. A very good correlation (r = 0.962, p < 0.001) was observed between the results obtained for the mouse liver DNA samples using LC-MS/MS SRM as compared to those obtained using a (32)P-postlabeling method. However, the levels of adducts observed following (32)P-postlabeling using butanol enrichment were approximately 3.7-fold lower. The LC-MS/MS method allowed the more precise quantitation of DNA adduct levels that were structurally characterized, in addition to a reduction in the time taken to perform the analysis when compared with the (32)P-postlabeling method.

Cigarette smoke contains a complex mixture of chemicals, including some that are genotoxic. A number of epidemiological and clinical studies have reported the association of increased DNA adduct levels with the development of lung cancer in smokers. The majority of chemicals present in cigarette smoke require cytochrome P450-mediated metabolic activation to form the ultimate reactive species that covalently binds with DNA. We have investigated the presence of a direct-acting ethylating agent present in cigarette smoke by studying the formation of N-7 ethylguanine (N-7EtG) following exposure of DNA to cigarette smoke in vitro. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with multiple reaction monitoring (MRM) was developed for the detection of N-7EtG in DNA. DNA samples were subjected to thermal hydrolysis to selectively release the N-7EtG, which was then quantified by LC-MS/MS MRM using a stable isotope internal standard [15N5]N-7EtG. The limit of detection of the method for N-7EtG was 2.0 fmol injected on column with 100 microg of calf thymus DNA as the matrix (0.6 N-7EtG adducts per 10(8) nucleotides). A linear dose-response was observed for the formation of N-7EtG in calf thymus DNA treated with diethyl sulfate at concentrations ranging from 1 to 1000 microM. Calf thymus DNA treated with smoke generated from 1, 5, and 10 commercially available cigarettes resulted in the formation of 1.3, 3.6, and 8.4 N-7EtG adducts per 10(8) nucleotides, respectively. There was a positive correlation between the formation of N-7EtG and the number of cigarettes (r = 0.9938). These results confirm the presence of an as yet unidentified direct acting ethylating agent in cigarette smoke, which is present at levels that can produce DNA damage that could ultimately have adverse implications for human health, particularly in the case of the development of lung cancer.

An edge detection is important for its reliability and security which delivers a better understanding of object recognition in the applications of computer vision, such as pedestrian detection, face detection, and video surveillance. This paper introduced two fundamental limitations encountered in edge detection: edge connectivity and edge thickness, those have been used by various developments in the state-of-theart. An optimal selection of the threshold for effectual edge detection has constantly been a key challenge in computer vision. Therefore, a robust edge detection algorithm using multiple threshold approaches (B-Edge) is proposed to cover both the limitations. The majorly used canny edge operator focuses on two thresholds selections and still witnesses a few gaps for optimal results. To handle the loopholes of the canny edge operator, our method selects the simulated triple thresholds that target to the prime issues of the edge detection: image contrast, effective edge pixels selection, errors handling, and similarity to the ground truth. The qualitative and quantitative experimental evaluations demonstrate that our edge detection method outperforms competing algorithms for mentioned issues. The proposed approach endeavors an improvement for both grayscale and colored images.INDEX TERMS Edge, edge connectivity, edge detection, edge width uniformity, threshold.SUDIPTA ROY received the Ph.D. degree in computer science and engineering from the Department of Computer Science and Engineering, University of Calcutta. He is currently with the Radiological Chemistry and Imaging Laboratory, Washington University in Saint Louis, USA. He has more than five years of experience in teaching and research. He is an author of more than 30 publications in refereed national and international journals and conferences, including the IEEE, Springer, Elsevier, and many others. He is an author of one book and many book chapters. He holds an U.S. patent in medical image processing and filed an Indian patent in smart agricultural system. His research interests include biomedical image analysis, image processing, steganography, artificial intelligence, big data analysis, machine learning, and big data technologies.

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