Unionists/researchers writing a book in co-operation: Importance in training/research dynamics

This text describes two different experiences of co-operation between unionists and researchers that resulted in writing of a book. We emphasize their similarities and differences and discuss the importance of these experiences in the dynamics of research and training in Ergonomics.     

巴西圣保罗州莫日-瓜苏河流流域中的汞:根据210Pb测年剖面估计的沿海泻湖与河流贡献之间的联系

引言 莫日-瓜苏河位于纳斯吉拉斯州,海拔高1450m.流淌470km后,该河流注入圣保罗州的帕尔杜河.其流域总面积为1400km2,其中有86%位于圣保罗州,包括一个工业化地区[1].     

An accessory marker derived from chromosome 20 and its co-existence with a mosaic trisomy 20 cell line

We report a 16-month-old boy with delayed psychomotor development, dysmorphic features, and failure to thrive. He had a mosaic karyotype detected prenatally: mos 46,XY/47,XY,+r(20)/47,XY,+20. After birth, the abnormal cell lines were confirmed in a number of tissues. The small ring chromosome was identified using fluorescence in situ hybridization as derived from chromosome 20. We compared our patient with previously reported cases of mosaic trisomy 20 detected prenatally and associated with an abnormal phenotype. In an attempt to characterize an r(20) syndrome, we also compared our case with two similar reports in the literature.     

Potential for bioremediation of the perchlorate‐contaminated sediments in the Las Vegas Wash area,Henderson, Nevada

This study investigates the potential for perchlorate biodegradation in the sediments of the Las Vegas Wash area in Henderson, Nevada. The continuous transport of perchlorate from a contaminated seepage to the Las Vegas Wash, Lake Mead, and the Colorado River has resulted in considerable deposition of perchlorate along the sediments of the Las Vegas Wash. The contaminated sediments act as a distributed source of perchlorate, making efforts to stop the flow of perchlorate to the Colorado River very challenging. In this study, perchlorate‐ reducing bacteria were enumerated and microcosm tests were performed to investigate the role of indigenous microorganisms and the limitations to natural perchlorate biodegradation in the contaminated sediments. The results of microcosm tests revealed that, despite the high number of perchloratereducing bacteria present, natural perchlorate in the area appears to be limited by (1) high salinity levels, the presence of nitrate, and the low perchlorate concentrations present in the sediments and (2) an insufficient carbon source. However, the potential for in situ bioremediation of the sediments along the Wash area is considered to be high due to the presence of significant numbers of perchlorate‐ reducing bacteria and to the ease in which an additional carbon source could be provided to sustain nitrate and perchlorate biodegradation. The economics of this process are expected to be very favorable; however, detailed cost estimates, pilot‐scale testing, and permit applications are required before this concept can be applied. © 2005 Wiley Periodicals, Inc.     

Comparison between UVA- and zero-valent iron-activated persulfate processes for degrading propylparaben

Conventional wastewater treatments are not efficient in removing parabens, which may thus end up in surface waters, posing a threat to aquatic biota and hu     

Human milk contamination by nine organochlorine pesticide residues (OCPs)

Abstract

Organochlorine pesticides (OCPs) are widely used around the world as insecticides, herbicides, fungicides, nematicides, and rodenticides. Despite banned in Brazil, the usage remains occurring in many countries. The persistence and extreme mobility of OCPs contribute to the contamination of the environment and the human body. The OCPs bioaccumulation in adipose tissue triggers the excretion into human milk during breastfeeding. Hence, the present study determined eighteen OCPs residues in the breast milk of mothers from the Western Region of Bahia State, Brazil. Nine different residue species were found, including beta-Hexachlorocyclohexane (9.24?±?0.00?ng g^?1 fat), delta- Hexachlorocyclohexane (22.15?±?10.48?ng g^?1 fat), Heptachlor (58.08?±?74.13?ng g^?1 fat), Aldrin (142.65?±?50.65?ng g^?1 fat), Dieldrin (774.62?±?472.68?ng g^?1 fat), Endosulfan I (408.44?±?245.51?ng g^?1 fat), Dichloro-diphenyl-dichloro-ethylene (29.17?±?22.42?ng g^?1 fat), Dichloro-diphenyl-trichloro-ethane (28.87?±?0.00?ng g^?1 fat) and Methoxychlor (1699.67?±?797.43?ng g^?1 fat). The Methoxychlor presence in all samples may reveal a recent exposure, while Dieldrin and Endosulfan I analyses can point to distant past exposure.     

Modeling a spatially restricted distribution in the Neotropics: How the size of calibration area affects the performance of five presence-only methods

We here examine species distribution models for a Neotropical anuran restricted to ombrophilous areas in the Brazilian Atlantic Forest hotspot. We extend the known occurrence for the treefrog Hypsiboas bischoffi (Anura: Hylidae) through GPS field surveys and use five modeling methods (BIOCLIM, DOMAIN, OM-GARP, SVM, and MAXENT) and selected bioclimatic and topographic variables to model the species distribution. Models were first trained using two calibration areas: the Brazilian Atlantic Forest (BAF) and the whole of South America (SA). All modeling methods showed good levels of predictive power and accuracy with mean AUC ranging from 0.77 (BIOCLIM/BAF) to 0.99 (MAXENT/SA). MAXENT and SVM were the most accurate presence-only methods among those tested here. All but the SVM models calibrated with SA predicted larger distribution areas when compared to models calibrated in BAF. OM-GARP dramatically overpredicted the species distribution for the model calibrated in SA, with a predicted area around 10⁶ km² larger than predicted by other SDMs. With increased calibration area (and environmental space), OM-GARP predictions followed changes in the environmental space associated with the increased calibration area, while MAXENT models were more consistent across calibration areas. MAXENT was the only method that retrieved consistent predictions across calibration areas, while allowing for some overprediction, a result that may be relevant for modeling the distribution of other spatially restricted organisms.     

Finished leather waste chromium acid extraction and anaerobic biodegradation of the products

Due to the amounts of chromium in the leachate resulting from leather leaching tests, chromium sulfate tanned leather wastes are very often considered hazardous wastes. To overcome this problem, one option could be recovering the chromium and, consequently, lowering its content in the leather scrap. With this objective, chromium leather scrap was leached with sulfuric acid solutions at low temperature also aiming at maximizing chromium removal with minimum attack of the leather matrix. The effects of leather scrap dimension, sulfuric acid and sodium sulfate concentration in the solutions, as well as extraction time and temperature on chromium recovery were studied, and, additionally, organic matrix degradation was evaluated. The best conditions found for chromium recovery were leather scrap conditioning using 25 mL of concentrated H₂SO₄/L solution at 293 or 313 K during 3 or 6 days. Under such conditions, 30–60 ± 5% of chromium was recovered and as low as 3–6 ± 1% of the leather total organic carbon (TOC) was dissolved. Using such treatment, the leather scrap area and volume are reduced and the residue is a more brittle material showing enhanced anaerobic biodegradability. Although good recovery results were achieved, due to the fact that the amount of chromium in eluate exceeded the threshold value this waste was still hazardous. Thus, it needs to be methodically washed in order to remove all the chromium de-linked from collagen.