Compensation of atmospheric CO2 buildup through engineered chemical shrinkage

Retrieval of background carbon dioxide into regional chemical extractors would counter anthropogenic inputs in a manner friendly to established industries. We demonstrate via atmospheric transport/scaling calculations that for idealized flat removal units, global coverage could be less than two hundred thousand square kilometers. The disrupted area drops to a small fraction of this with engineering into the vertical to bypass laminarity. Fence structures and artificial roughness elements can both be conceived. Sink thermodynamics are analyzed by taking calcium hydroxide as a sample reactant. Energy costs could be minimized at near the endothermicity of binding reversal. In the calcium case the value is 25 kcal mole-1, as against a fuel carbon content of 150 in the same units. Aqueous kinetics are less than favorable for the hydroxide, but misting could counteract slow liquid phase transfer. Properties of superior scrubbers are outlined

Chemical transport modeling of potential atmospheric CO2 sinks

The potential for carbon dioxide (CO2) sequestration via engineered chemical sinks is investigated using a three dimensional chemical transport model (CTM). Meteorological and chemical constraints for flat or vertical systems that would absorb CO2 from the atmosphere, as well as an example chemical system of calcium hydroxide (Ca(OH)2) proposed by Elliott et al. [Compensation of atmospheric CO2 buildup through engineered chemical sinkage, Geophys. Res. Lett. 28 (2001) 1235] are reviewed. The CTM examines land based deposition sinks, with 4° × 5° latitude/longitude resolution at various locations, and deposition velocities (v). A maximum uptake of ∼20 Gton (1015 g) Cyr-1 is attainable with v ≥ 5 cms-1 at a mid-latitude site. The atmospheric increase of CO2 (3 Gtonyr-1) can be balanced by an engineered sink with an area of no more than 75, 000 km2 at v of 1 cms-1. By building the sink upwards or splitting this area into narrow elements can reduce the active area by more than an order of magnitude as discussed in Dubey et al. © 2002 Elsevier Science Ltd. All rights reserved

Immunohistochemical studies on progressive pathology of ischaemia reperfusion acute kidney injury in male Sprague Dawley rats

270-274Acute kidney injury (AKI) is a major problem in ICU patient, majority of the cases even after functional recovery ended with chronic kidney disease. In the present study, we investigated the immunohistochemical change in progressive pathology of ischaemia reperfusion induced acute kidney injury. Male Sprague Dawley (SD) rats were subjected to 35 min of renal ischemia followed by reperfusion periods of day 1, 4, 7, 14 and 28. Renal injury was confirmed by the increase serum creatinine level. The vascular and tubular changes in kidneys were studied by the CD31 and vimentin immunohistochemistry respectively. In this study, no significant changes were observed in CD31 positive cells, though lower densities of capillaries were noticed in the tubulo-interstitial lesion on day 28 of reperfusion. Significant increase in vimentin positive cells, which is a marker of undifferentiated cells, was observed on day 4 and day 7 of reperfusion. The immature cells were also present on day 28 of reperfusion indicating that these cells may would have led further progressive pathological changes in kidney even after the functional and morphological normalization

Self-Mating in the Definitive Host Potentiates Clonal Outbreaks of the Apicomplexan Parasites Sarcocystis neurona and Toxoplasma gondii

Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. In contrast, selfing and other life history traits, such as asexual expansion of tissue-cysts by oral transmission among intermediate hosts, have been proposed to explain the genetic basis for the clonal population structure of T. gondii. In this study, we investigated the contributing roles self-mating and sexual recombination play in nature to maintain clonal population structures and produce or expand parasite clones capable of causing disease epidemics for two tissue encysting parasites. We applied high-resolution genotyping against strains isolated from a T. gondii waterborne outbreak that caused symptomatic disease in 155 immune-competent people in Brazil and a S. neurona outbreak that resulted in a mass mortality event in Southern sea otters. In both cases, a single, genetically distinct clone was found infecting outbreak-exposed individuals. Furthermore, the T. gondii outbreak clone was one of several apparently recombinant progeny recovered from the local environment. Since oocysts or sporocysts were the infectious form implicated in each outbreak, the expansion of the epidemic clone can be explained by self-mating. The results also show that out-crossing preceded selfing to produce the virulent T. gondii clone. For the tissue encysting coccidia, self-mating exists as a key adaptation potentiating the epidemic expansion and transmission of newly emerged parasite clones that can profoundly shape parasite population genetic structures or cause devastating disease outbreaks

Toxoplasma gondii infection in workers occupationally exposed to unwashed raw fruits and vegetables: a case control seroprevalence study

<p>Abstract</p> <p>Background</p> <p>Through a case control seroprevalence study, we sought to determine the association of <it>Toxoplasma gondii </it>infection with occupational exposure to unwashed raw fruits and vegetables.</p> <p>Methods</p> <p>Subjects, numbering 200, who worked growing or selling fruits and vegetables, and 400 control subjects matched by age, gender, and residence were examined by enzyme immunoassays for the presence of anti-<it>Toxoplasma </it>IgG and IgM antibodies. Socio-demographic, clinical, and behavioral characteristics from the study subjects were obtained.</p> <p>Results</p> <p>Of the 200 fruit and vegetable workers, 15 (7.5%) of whom, and 31 (7.8%) of the 400 controls were positive for anti-<it>Toxoplasma </it>IgG antibodies (<it>P </it>= 0.96). Anti-<it>Toxoplasma </it>IgM antibodies were found in 2 (1%) of the fruit workers and in 11 (2.8%) of the control subjects (<it>P </it>= 0.23). Seroprevalence of <it>Toxoplasma </it>antibodies increased with age (<it>P </it>= 0.0004). In addition, seropositivity to <it>Toxoplasma </it>was associated with ill status (<it>P </it>= 0.04), chronic tonsillitis (<it>P </it>= 0.03), and reflex impairment (<it>P </it>= 0.03). Multivariate analysis showed that <it>Toxoplasma </it>infection was associated with consumption of raw meat (OR = 5.77; 95% CI: 1.15-28.79; <it>P </it>= 0.03), unwashed raw fruits (OR = 2.50; 95% CI: 1.11-5.63; <it>P </it>= 0.02), and living in a house with soil floors (OR = 3.10; 95% CI: 1.22-7.88; <it>P </it>= 0.01), whereas <it>Toxoplasma </it>infection was negatively associated with traveling abroad (OR = 0.28; 95% CI: 0.12-0.67; <it>P </it>= 0.005).</p> <p>Conclusions</p> <p>This is the first report of seroprevalence and contributing factors for <it>Toxoplasma </it>infection in workers occupationally exposed to unwashed raw fruits and vegetables, and the results may help in the design of optimal preventive measures against <it>Toxoplasma </it>infection especially in female workers at reproductive age.</p

Diabetes screening with hemoglobin A1c prior to a change in guideline recommendations: prevalence and patient characteristics

<p>Abstract</p> <p>Background</p> <p>In January 2010, the American Diabetes Association recommended the use of hemoglobin A1c (Hgb A1c) to screen and diagnose diabetes. This study explored the prevalence and clinical context of Hgb A1c tests done for non-diabetic primary care patients for the three years prior to the release of the new guidelines. We sought to determine the provision of tests in non-diabetic patients age 19 or over, patients age 45 and over (eligible for routine diabetes screening), the annual change in the rate of this screening test, and the patient characteristics associated with the provision of Hgb A1c screening.</p> <p>Methods</p> <p>We conducted a retrospective study using data routinely collected in Electronic Medical Records. The participants were thirteen community-based family physicians in Toronto, Ontario. We calculated the proportion of non diabetic patients who had at least one Hbg A1c done in three years. We used logistic generalized estimating equation with year treated as a continuous variable to test for a non-zero slope in yearly Hbg A1c provision. We modelled screening using multivariable logistic regression.</p> <p>Results</p> <p>There were 11,792 non-diabetic adults. Of these, 1,678 (14.2%; 95%CI 13.6%-14.9%) had at least one Hgb A1c test done; this was higher for patients 45 years of age or older (20.2%; 95% CI 19.3% - 21.2%). The proportion of non-diabetic patients with an A1c test increased from 5.2% in 2007 to 8.8% in 2009 (p < 0.0001 for presence of slope). Factors associated with significantly greater adjusted odds ratios of having the test done included increasing diastolic blood pressure, increasing fasting glucose, increasing body mass index, increasing age, as well as male gender and presence of hypertension, but not smoking status or LDL cholesterol. Patients living in the highest income quintile neighbourhoods had significantly lower odds ratios of having this test done than those in the lowest quintile (p < 0.001).</p> <p>Conclusions</p> <p>A large and increasing proportion of the non-diabetic patients we studied have had an Hgb A1c for screening prior to guidelines recommending the test for this purpose. Several risk factors for cardiovascular disease or diabetes were associated with the provision of the Hgb A1c. Early uptake of the test may represent appropriate utilization.</p

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur