Diesel oil discrimination by origin and type using physicochemical properties and multivariate analysis

The objective of this work is to provide models for the prediction and classification of B4 (volume fraction of 4% in conventional diesel) and diesel samples commercialized in the state of Minas Gerais - Brazil, with respect to its origins and types. Hence, we determined physical chemical parameters, such as, specific gravity, flash point and distillation curves for two distinct diesel samples of metropolitan and interior types from different refineries. Through PCA (principal components analysis), the first three principal components separated the samples by origin and types, with percentage of explained variance greater than 96%. For the LDA (linear discriminant analysis), the information in the invoice receipt of samples regarding origin and type were used. In the simultaneous prediction of origin and type, the percentage of correct classification was above 94%, considering the classification error, due to the similarity between some samples.     

The Influence of MgH2 on the Assessment of Electrochemical Data to Predict the Degradation Rate of Mg and Mg Alloys

Mg and Mg alloys are becoming more and more of interest for several applications. In the case of biomaterial applications, a special interest exists due to the fact that a predictable degradation should be given. Various investigations were made to characterize and predict the corrosion behavior in vitro and in vivo. Mostly, the simple oxidation of Mg to Mg²⁺ ions connected with adequate hydrogen development is assumed, and the negative difference effect (NDE) is attributed to various mechanisms and electrochemical results. The aim of this paper is to compare the different views on the corrosion pathway of Mg or Mg alloys and to present a neglected pathway based on thermodynamic data as a guideline for possible reactions combined with experimental observations of a delay of visible hydrogen evolution during cyclic voltammetry. Various reaction pathways are considered and discussed to explain these results, like the stability of the Mg⁺ intermediate state, the stability of MgH₂ and the role of hydrogen overpotential. Finally, the impact of MgH₂ formation is shown as an appropriate base for the prediction of the degradation behavior and calculation of the corrosion rate of Mg and Mg alloys.     

A balanced technique for preparation of specimens from pathogenicity studies for scanning electron microscopy

This paper reports our experiences with preparing delicate biological specimens for scanning electron microscopy. Three different washing methods were evaluated: One method allowed the analysis of the location of the bacterium Mycoplasma mobile on piscine gill epithelium and the optimal evaluation of histopathologic changes caused by this microbe. These results were achieved when specimens were washed three times in a cacodylic acid buffer after completion of the in vitro infection experiment in gill explant cultures. We also found that of three different concentrations of glutaraldehyde, a fixation with a 1.5% solution was sufficient to achieve excellent structural preservation, even without using post fixation in osmium tetroxide. Furthermore, this study showed that the use of acetone-carbon dioxide in the critical point drying procedure resulted in well-preserved piscine gill epithelium and mycoplasmas. Finally, long-term storage of tissue specimens in 0.1 M cacodylic acid buffer is possible if the buffer is changed on a monthly basis to avoid growth of unwanted microorganisms, such as fungi.     

Determination of metronidazole and hydroxymetronidazole in trout by a high-performance liquid chromatographic method

A high-performance liquid chromatographic (HPLC) method based on solid phase extraction was developed for determination of metronidazole (MNZ) and its metabolite hydroxymetronidazole (MNZ-OH) in muscle and skin tissues of rainbow trout. Tinidazole (TNZ) was used as internal standard. The compounds were extracted with acetonitrile and the extract was evaporated and redissolved in a mixture of ethyl acetate and hexane (1:2). The extract was cleaned up by solid phase extraction on a silica cartridge. The extract was analysed by reverse phase gradient HPLC on a C18 column followed by ultraviolet detection at 325nm. The limit of detection was 2.8 μg/kg for both compounds in muscle. The estimated limits of detection in skin tissue were 3 μg/kg for MNZ and 5 μg/kg for MNZ-OH. The mean recoveries of MNZ in muscle calculated without use of internal standard were 93% and 81% at levels of 10 μg/kg and 25-100 μg/kg respectively. The mean recovery of MNZ-OH in muscle was 79% at a level of 10-100 μg/kg. The mean relative repeatability standard deviations on spiked muscle tissue were 3.3% for MNZ and 3.2% for MNZ-OH at a level of 10-100 μg/kg. The method was applied to trout given feed containing MNZ in an aquaculture pilot plant. Residues of MNZ and MNZ-OH were detected in muscle and skin tissues shortly after the administration period but not 3 weeks later.     

Halogenated veneers: protein cross-linking and halogenation in the jaws of nereis, a marine polychaete worm

Mineralized tissues are produced by most living organisms for load and impact functions. In contrast, the jaws of the clam worm, Nereis, are hard without mineralization. However, they are peculiarly rich in halogens, which are associated with a variety of post-translationally modified amino acids, many of which are multiply halogenated by chlorine, bromine, and/or iodine. Several of these modified amino acids, namely dibromohistidine, bromoiodohistidine, chloroiodotyrosine, bromoiodotyrosine, chlorodityrosine, chlorotrityrosine, chlorobromotrityrosine, and bromoiodotrityrosine, have not been previously reported. We have found that the distributions of Cl, Br, and I differ: Cl is widespread whereas Br and I, although not colocalized, are concentrated in proximity to the external jaw surfaces. By using nanoindentation, we show that Br and I are unlikely to play a purely mechanical role, but that the local Zn and Cl concentrations and jaw microstructure are the prime determinants of local jaw hardness. Several of the post-translationally modified amino acids are akin to those found in various sclerotized structures of invertebrates, and we propose that they are part of a cross-linked protein casing.     

Does Barbie make girls want to be thin? The effect of experimental exposure to images of dolls on the body image of 5- to 8-year-old girls.

[Correction Notice: An erratum for this article was reported in Vol 42(6) of Developmental Psychology (see record 2006-20488-033). A substantive error occurs in the Body shape dissatisfaction section on page 287. The sentence describing the calculation of body shape dissatisfaction scores from girls' responses to the Child Figure Rating Scale should instead read as follows: "A body shape dissatisfaction score was computed by subtracting the girl's actual from her ideal body size."] The ubiquitous Barbie doll was examined in the present study as a possible cause for young girls' body dissatisfaction. A total of 162 girls, from age 5 to age 8, were exposed to images of either Barbie dolls, Emme dolls (U.S. size 16), or no dolls (baseline control) and then completed assessments of body image. Girls exposed to Barbie reported lower body esteem and greater desire for a thinner body shape than girls in the other exposure conditions. However, this immediate negative impact of Barbie doll was no longer evident in the oldest girls. These findings imply that, even if dolls cease to function as aspirational role models for older girls, early exposure to dolls epitomizing an unrealistically thin body ideal may damage girls' body image, which would contribute to an increased risk of disordered eating and weight cycling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validation of an enzyme immunoassay for monitoring Cry1Ab toxin in soils planted with Bt-maize (MON810) in a long-term field trial on four South German sites

For monitoring the environmental impacts of a genetically modified crop well-established methods are a key requirement for the collection of appropriate data. With regard to the fate of Cry1Ab protein from Bt-maize MON810 released by root exudates, plant residues and pollen deposition into soil, a highly specific and sensitive sandwich enzyme immunoassay for detection and quantification of Cry1Ab in soil matrix was developed. The assay was validated according to the criteria of EU-Decision 2002/657/EC for a range of soils originating from four selected experimental field sites in South Germany, where Bt-maize MON810 has been cultivated. On three sites Bt-maize was grown permanently for eight years whereas one site was cropped with Bt-maize for one year only. The validation of the method showed that the assay fulfils the validation criteria as prescribed in the guidelines of the EU-Decision with minor restrictions. When the assay was applied to field soil samples collected from the selected four experimental sites six months after harvest, no Cry1Ab protein was detectable. By ELISA-determination and quantification of Cry1Ab protein in soils collected from these sites at further time points more profound knowledge about the long-term behaviour of Cry1Ab protein in soil will be obtained.     

<Emphasis Type="Italic">Chromohalobacter beijerinckii</Emphasis>: a psychrophilic,extremely halotolerant and enzymatically active microbe from salted food with the capacity for biogenic amine production

The species Chromohalobacter beijerinckii comb. nov. was recently proposed in order to accommodate strain Pseudomonas beijerinckii Hof 1935, which was found in salted beans, and a novel isolate, strain 3b, which was obtained from salted herrings of the Baltic sea. The species is psychrophilic, growing from 5 to 42 °C and highly salt-tolerant, growing between 0.5 and 25% NaCl. Of interest to food microbiology are several properties, which are described here, such as the enzymatic activity of Ch. beijerinckii strain 3b against fish protein, cod liver oil and butter. In addition, the strain possesses decarboxylases of lysine, tyrosine and histidine and can thus be a producer of biogenic amines, mainly histamine and tyramine. In media containing 10% NaCl, Ch. beijerinckii strain 3b is resistant to the antibiotics bacitracin, chloramphenicol, streptomycin, tetracycline and novobiocin. The potential impact of these properties, especially of the biogenic amine content in salted food, which were not known so far from other species of the genus Chromohalobacter, is discussed.     

GIS and Spatial Knowledge Production for Neighborhood Revitalization: Negotiating State Priorities and Neighborhood Visions

Abstract: In this article, we examine the role of geographic information systems used by neighborhood organizations in their planning and revitalization efforts in US inner cities. The use of GIS is related to marked changes in the roles and responsibilities of neighborhood organizations as part of a neoliberal policy agenda that expects them to play an increasing role in neighborhood revitalization. Drawing upon research about neighborhood organizations in Milwaukee, Minneapolis, and St. Paul, we show how the spatial knowledge and revitalization strategies produced by these organizations frequently reflect and reinforce those promoted by the state. At the same time, some neighborhood organizations construct alternative knowledge through their use of GIS and employ alternative visions of neighborhood revitalization as they navigate the tensions between community visions and state priorities.     

Satellite-to-satellite tracking and satellite gravity gradiometry (Advanced techniques for high-resolution geopotential field determination)

The purpose of satellite-to-satellite tracking (SST) and/or satellite gravity gradiometry (SGG) is to determine the gravitational field on and outside the Earth's surface from given gradients of the gravitational potential and/or the gravitational field at satellite altitude. In this paper both satellite techniques are analysed and characterized from a mathematical point of view. Uniqueness results are formulated. The justification is given for approximating the external gravitational field by finite linear combination of certain gradient fields (for example, gradient fields of single-poles or multi-poles) consistent to a given set of SGG and/or SST data. A strategy of modelling the gravitational field from satellite data within a multiscale concept is described; illustrations based on the EGM96 model are given.