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Copyright of Revista Salud UIS is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research is committed to develop a semi-automated landforms classification method for a subtropical area located in the southeast of Brazil, using optical medium- resolution imagery from ASTER/Terra. A four-level semantic network driven by a set of spectral, textural, and geomorphometric variables was used. The textural and geomorphometric variables were extracted from an ASTER/Terra DEM. The semantic network was initially conceived to classify macro morphogenetic landforms and was then further detailed to allow a finer classification, which amounted to eleven classes of morph ographic landforms. In order to assess the classification accuracy, statistical indices were derived from a contingency table obtained by means of a comparison between the classified scene and a reference map. The final agreement in dices for the macro and detailed landforms classifications were 76 percent and 80 percent, respectively. The employed object-based image analysis has proved to be a suitable method for semi- automated procedures in the classification of landforms. [ABSTRACT FROM AUTHOR]

Trimetoquinol (TMQ) (1-(3’,4’,5’-trimethoxybenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, m.w. 345) is the prototype tetrahydroisoquinoline pharmaceutical. TMQ is marketed as a bronchodilator in human medicine; in horse racing, TMQ is listed as an Association of Racing Commissioners International (ARCI) class 3 foreign substance. As such, TMQ is considered to have the potential to affect racing performance in horses, and a validated qualitative confirmatory method is required to regulate its use in racing. We selected 8 μg kg−1 of TMQ IV as a safe and effective dose for studies on its metabolism and analytical detection in horses. We developed a solid phase extraction method for recovery of TMQ and its metabolites from equine urine, identified suitable high performance liquid chromatographic conditions for these substances and our internal standard, papaverine, and developed a highly sensitive ESI(+)-LC-MS-MS method (estimated LOD, 100 pg mL−1) for TMQ and its major metabolites in equine urine. Multiple Reaction Monitoring (MRM) analysis of unhydrolyzed post-administration urine showed small amounts of unchanged TMQ, along with glucuronide, methylated, and sulfated metabolites, with glucuronide metabolites predominating. Following glucuronidase hydrolysis, recovered parent TMQ peaked at relatively high concentrations (>300 ng mL−1) within 1 h of administration and thereafter declined. The methylated metabolites of TMQ peaked later and at comparable total concentrations, and thereafter declined more slowly. These data suggest that glucuronide hydrolysis of post-administration urine samples will allow recovery of readily identifiable quantities of parent TMQ. These findings, combined with the highly sensitive LC-MS-MS detection of parent TMQ described herein suggest that glucuronide hydrolysis of post-administration urine, followed by LC-MS-MS or other analysis, will allow effective regulatory control of this agent in racing horses. [ABSTRACT FROM AUTHOR]

Chromium-resistant bacteria (CRB) isolated from soils can be used to reduce toxic Cr(VI) from contaminated environments. This study assessed in vitro reduction of hexavalent Cr using a cell-free extract (CFE) of CRB isolated from soil contaminated with dichromate. One isolate, ES 29, that substantially reduced Cr(VI) was identified as a Bacillus species by 16S rRNA gene-sequence homology. The isolate reduced Cr(VI) under aerobic conditions, using NADH as an electron donor and produced a soluble Cr(VI)-reducing enzyme stimulated by copper (Cu2+). The CFE of the bacterial isolate reduced 50% of Cr(VI) in 6 h. The Cr(VI)-reduction activity of the CFE had a Km of 7.09 μM and a Vmax of 0.171 μmol min-1 mg-1 protein. Mercury inhibited the enzyme, but not competitively, with a Vmax of 0.143 μmol min-1 mg-1 protein, a Km of 7.07 μM and a Ki of 1.58 μM. This study characterizes the enzymatic reduction of Cr(VI) by Bacillus sp. ES 29 which can be used for the bioremediation of chromate. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe the dual-frequency and dual-polarization emission of a diode-pumped vertical external-cavity semiconductor laser at 852 nm dedicated to the coherent population trapping of cesium atoms. The output power reaches ~20 mW on each frequency, with a frequency difference in the gigahertz range. [ABSTRACT FROM PUBLISHER]