Safety culture maturity assessment for mining activities in South America.

BACKGROUND: Health and safety is a crucial issue in the mining industry due to the implication of accidents in the sector. OBJECTIVE: This study determines the safety culture characteristics in several mining activities from South America. METHODS: A survey of the safety culture maturity has been done by means of 24 questions regarding the type of activity, number of employees and safety culture characteristics of the activity: information of accidents and incidents, organizational structure to deal with information, involvement of the company in health and safety issues, the way it communicates accidents and incidents and commitment of the company towards health and safety. RESULTS: The questionnaire was completed by 62 managers from Bolivia, Peru and Colombia. Results show different behaviors depending on the type of company, Artisanal or Large-Scale Mines, ASM and LSM respectively. LSM show a level of maturity according to the size of the company, while ASM does not have a clear trend in terms of size, even though there is a relationship between employees and safety culture maturity. In addition, a remarkable difference can be seen between activities with and without continuous improvement systems implemented. CONCLUSIONS: Large scale mining improves their level of safety culture as the size of the company increases, because procedures and control systems are implemented. Cooperatives or small companies also achieve substantial gains when they introduce similar systems.

Hepatic CD36 downregulation parallels steatosis improvement in morbidly obese undergoing bariatric surgery.

BACKGROUND: The notion that hepatic expression of genes involved in lipid metabolism is altered in obese patients is relatively new and its relationship with hepatic steatosis and cardiometabolic alterations remains unclear. OBJECTIVE: We assessed the impact of Roux-en-Y gastric bypass surgery (RYGB) on the expression profile of genes related to metabolic syndrome in liver biopsies from morbidly obese individuals using a custom-made, focused cDNA microarray, and assessed the relationship between the expression profile and hepatic steatosis regression. MATERIALS AND METHODS: Plasma and liver samples were obtained from patients at baseline and 12 months after surgery. Samples were assayed for chemical and gene expression analyses, as appropriate. Gene expression profiles were assessed using custom-made, focused TaqMan low-density array cards. RESULTS: RYGB-induced weight loss produced a favorable reduction in fat deposits, insulin resistance (estimated by homeostasis model assessment of insulin resistance (HOMA-IR)), and plasma and hepatic lipid levels. Compared with the baseline values, the gene expression levels of key targets of lipid metabolism were significantly altered: CD36 was significantly downregulated (-40%; P=0.001), whereas APOB (+27%; P=0.032) and SCARB1 (+37%; P=0.040) were upregulated in response to surgery-induced weight reduction. We also observed a favorable reduction in the expression of the PAI1 gene (-80%; P=0.007) and a significant increase in the expression of the PPARA (+60%; P=0.014) and PPARGC1 genes (+36%; P=0.015). Notably, the relative fold decrease in the expression of the CD36 gene was directly associated with a concomitant reduction in the cholesterol (Spearman's r=0.92; P=0.001) and phospholipid (Spearman's r=0.76; P=0.04) contents in this tissue. CONCLUSIONS: For the first time, RYGB-induced weight loss was shown to promote a favorable downregulation of CD36 expression, which was proportional to a favorable reduction in the hepatic cholesterol and phospholipid contents in our morbidly obese subjects following surgery.

Electrostatic interactions observed when imaging proteins with the atomic force microscope.

The atomic force microscope (AFM) is now an established and valuable tool for the study of biological macromolecules in aqueous environments. In this paper we form a patterned boundary via the microcontact printing of individually isolated proteins, covalently attached to a solid support. We use this boundary to investigate electrostatic interactions that can occur between an AFM tip and a protein surface during imaging in solution. The observed height variations of the protein film are found to be a combination of not only structural considerations and thickness of the protein film, but also the repulsive contribution from electrostatic interactions between the AFM tip and the sample. These variations in measured heights of the protein surface can be described by Derjaguin, Landau, Verway, Overbeek (DLVO) theory. Our experimental results show that height measurements can be manipulated either negatively or positively by adjusting the pH and concentration of the electrolyte buffer that is utilised.

High-resolution detection of adulteration of maize oil using multi-component compound-specific delta13C values of major and minor components and discriminant analysis.

Maize oil commands a premium price and is thus a target for adulteration with cheaper vegetable oils. Detection of this activity presents a particular challenge to the analyst because of the natural variability in the fatty acid composition of maize oils and because of their high sterol and tocopherol contents. This paper describes a method that allows detection of adulteration at concentrations of just 5% (m/m), based on the Mahalanobis distances of the principal component scores of the delta(13)C values of major and minor vegetable oil components. The method makes use of a database consisting of delta(13)C values and relative abundances of the major fatty acyl components of over 150 vegetable oils. The sterols and tocopherols of 16 maize oils and 6 potential adulterant oils were found to be depleted in (13)C by a constant amount relative to the bulk oil. Moreover, since maize oil contains particularly high levels of sterols and tocopherols, their delta(13)C values were not significantly altered when groundnut oil was added up to 20% (m/m) and it is possible to use the values for the minor components to predict the values that would be expected in a pure oil; therefore, comparison of the predicted values with those obtained experimentally allows adulteration to be detected. A refinement involved performing a discriminant analysis on the delta(13)C values of the bulk oil and the major fatty acids (16:0, 18:1 and 18:2) and using the Mahalanobis distances to determine the percentage of adulterant oil present. This approach may be refined further by including the delta(13)C values of the minor components in the discriminant analysis thereby increasing the sensitivity of the approach to concentrations at which adulteration would not be attractive economically.

Prevalence of the C282Y mutation for haemochromatosis on the Island of Majorca.

The C282Y mutation of the HFE gene has been reported to be present in most of the patients with hereditary haemochromatosis (HH) of Northern European ancestry. HH affects approximately 1/300 individuals, but it is not evenly distributed in the different European countries. In the present study, polymerase chain reaction (PCR) and restriction-enzyme digestion were used to analyse the frequency of the most important mutation in haemochromatosis (C282Y) in subjects from Majorca (Balearic Islands, Spain) and patients with haemochromatosis. The results were compared with other studies from Spain and Europe. A total of 420 Majorcan chromosomes were analysed and the C282Y mutation was observed at a frequency of 2.62%+/-0.8 (11 heterozygotes: eight men and three women). In the group of hereditary haemochromatosis probands, 13 out of 14 were homozygous for the C282Y mutation. In the distribution of the C282Y mutation, a north-west to south-east cline was detected, supporting the Celtic origin of this mutation.

delta 13C analyses of vegetable oil fatty acid components, determined by gas chromatography--combustion--isotope ratio mass spectrometry, after saponification or regiospecific hydrolysis.

The delta 13C values of the major fatty acids of several different commercially important vegetable oils were measured by gas chromatography--combustion--isotope ratio mass spectrometry. The delta 13C values obtained were found to fall into two distinct groups, representing the C3 and C4 plants classes from which the oils were derived. The delta 13C values of the oils were measured by continuous flow elemental isotope ratio mass spectrometry and were found to be similar to their fatty acids, with slight differences between individual fatty acids. Investigations were then made into the influence on the delta 13C values of fatty acids of the position occupied on the glycerol backbone. Pancreatic lipase was employed to selectively hydrolyse fatty acids from the 1- and 3-positions with the progress of the reaction being followed by high-temperature gas chromatography in order to determine the optimum incubation time. The 2-monoacylglycerols were then isolated by thin-layer chromatography and fatty acid methyl esters prepared. The delta 13C values obtained indicate that fatty acids from any position on the glycerol backbone are isotopically identical. Thus, whilst quantification of fatty acid composition at the 2-position and measurement of delta 13C values of oils and their major fatty acids are useful criteria in edible oil purity assessment, measurement of delta 13C values of fatty acids from the 2-position does not assist with oil purity assignments.

Molecular analysis of the (CGG)n expansion in the FMR-1 gene in 59 Spanish fragile X syndrome families.

The fragile X mental retardation syndrome is caused by an expansion of a trinucleotide repeat (CGG)n in the FMR-1 gene. Molecular genetic study of fragile X provides accurate diagnosis and facilitates genetic counseling in families with affected members. We present here the molecular study of 59 Spanish fragile X syndrome families using probe StB 12.3 and the polymerase chain reaction (PCR) of the (CGG)n repeat sequence of the FMR-1 gene. The results obtained have allowed us to characterize 455 individuals, including eight prenatal diagnoses. The clinical diagnosis of fragile X in 89 affected males was confirmed, 137 female carriers were identified (48 of whom were mentally retarded), 176 individuals "at risk" were found not to have the expansion, and 12 cases of normal transmitting males (NTM) were detected. In the sample studied, no de novo mutations were detected, nor any mutation different from that described for the (CGG)n expansion. One nonmentally retarded male was detected as having an unmethylated CpG island for the FMR-1 gene, but with more than 200 CGG repeats (high functioning male). The analysis of the (CGG)n repeat in 208 normal chromosomes gave an allele distribution similar to that in other Caucasoid population groups, with alleles of 29 and 30 CGG repeats accounting for 46% of the chromosomes. The combination of Southern analysis and PCR of the (CGG)n repeat is highly efficient for diagnosis, compared with cytogenetic techniques, especially in the detection of female carriers, NTMs, and prenatal diagnosis, enabling accurate genetic counseling to be provided in all cases.

Incidence of dermatophytoses in rabbit farms in Catalonia, Spain, and its repercussion on human health.

Over the past decades there has been an important increase in the incidence of dermatophytoses in humans as a result of contact with animals, although etiological agents can vary as can the animals transmitting the disease. A large-scale study was carried out in 220 farms raising rabbits for consumption. Most of the farms (85%) were located in the autonomous community of Catalonia (Spain). Mycological studies showed that 79.5% of the rabbits were infected with Trichophyton mentagrophytes var. granulosum. Microsporum canis was isolated in only two animals, which had been imported from France. Healthy animal carriers were detected in 3.2% of the apparently non-infected farms. T. mentagrophytes were also found in samples taken from rabbits' nests and from the surrounding environment of the two infected farms. In a survey carried out among the staff responsible for the care of the animals, 77% of those working on infected farms suffered or had suffered dermatophytic lesions. This was confirmed in 8 out of 10 cases sampled. Attention is drawn to the high incidence of dermatophytoses in rabbits on farms and the importance of T. mentagrophytes as the etiological agent of tinea in people in close contact with infected animals.