Multi-year characterization of aerosol black carbon concentrations over a semiarid tropical site Udaipur.

Continuous and multi-year (2008-2012) measurements of black carbon (BC) mass concentrations (MBC), carried out from the semiarid tropical site Udaipur (24.6° N, 74° E, 580 m a.s.l.) near the western Indian desert, are analyzed for their region-specific features. MBC varied over a wide range during the period of study, with the hourly mean values occurring as low as 0.09 to as high as 49.1 µg m-3, with the multi-year average ~ 4.5 ± 2.6 µg m-3. Annual variations showed the highest concentrations during November and December (winter seasonal mean = 7.4 ± 3.3 µg m-3) and the lowest in the monsoon months of July and August (monsoon seasonal mean = 2.5 ± 2.2 µg m-3). MBC showed significant inverse relationship with the planetary boundary layer height (ρ ~ - 0.50) as well as ventilation coefficient (ρ ~ - 0.72). Alike aforesaid atmospheric dynamic parameters, T, WS, and RH also possessed statistically significant negative correlations with monthly MBC. Enhancement in annual as well as diurnal amplitude in MBC during deficient monsoon years relative to excessive monsoon years have given marked indication of BC sink mechanism due to precipitation. Roles of long-range regional air pollutant transport also have been identified. Identical and consistent seasonal variation in percentage contribution of MBC with PM2.5 (varying from 2.6 to 9.1%) and absorption Angstrom exponent (αabs, monthly mean values varying from 0.77 ± 0.04 to 1.16 ± 0.08) gives evidence of substantial amount of enhanced anthropogenic source activities of fossil fuel incomplete combustion in post-monsoon and winter period.

Subtotal colectomy for intestinal Behcet's disease: a histopathological surprise.

A 40-year-old male who was diagnosed to be having ileocaecal tuberculosis by colonoscopy elsewhere was put on antitubercular treatment. Despite therapy over three months patient had recurrent bouts of lower abdominal pain and was admitted repeatedly with features of subacute intestinal obstruction. CT- abdomen revealed concentric large bowel thickening at multiple sites with features of stenosing lesions. Patient underwent an exploratory laparotomy and subtotal colectomy was done for the diseased large bowel. Post operative histopathological examination revealed it to be Behcet's disease. We report a rare case of intestinal Behcet's disease requiring subtotal colectomy.