Peroxisomal 3-ketoacyl-CoA thiolase B (Thb) catalyzes the final step in the peroxisomal β-oxidation of straight-chain acyl-CoAs and is under the transcription control of the nuclear hormone receptor ...PPARα. PPARα binds to and is activated by the synthetic compound Wy14,643 (Wy). Here, we show that the magnitude of Wy-mediated induction of peroxisomal β-oxidation of radiolabeled (1-(14)C) palmitate was significantly reduced in mice deficient for Thb. In contrast, mitochondrial β-oxidation was unaltered in Thb(-/-) mice. Given that Wy-treatment induced Acox1 and MFP-1/-2 activity at a similar level in both genotypes, we concluded that the thiolase step alone was responsible for the reduced peroxisomal β-oxidation of fatty acids. Electron microscopic analysis and cytochemical localization of catalase indicated that peroxisome proliferation in the liver after Wy-treatment was normal in Thb(-/-) mice. Intriguingly, micro-array analysis revealed that mRNA levels of genes encoding cholesterol biosynthesis enzymes were upregulated by Wy in Wild-Type (WT) mice but not in Thb(-/-) mice, which was confirmed at the protein level for the selected genes. The non-induction of genes encoding cholesterol biosynthesis enzymes by Wy in Thb(-/-) mice appeared to be unrelated to defective SREBP-2 or PPARα signaling. No difference was observed in the plasma lathosterol/cholesterol ratio (a marker for de novo cholesterol biosynthesis) between Wy-treated WT and Thb(-/-) mice, suggesting functional compensation. Overall, we conclude that ThA and SCPx/SCP2 thiolases cannot fully compensate for the absence of ThB. In addition, our data indicate that ThB is involved in the regulation of genes encoding cholesterol biosynthesis enzymes in the liver, suggesting that the peroxisome could be a promising candidate for the correction of cholesterol imbalance in dyslipidemia.
The contribution of BRCA1 and BRCA2 to breast cancer incidence in Cuba has not yet been explored. In order to estimate the proportion of breast cancers due to BRCA1 and BRCA2 mutations in Cuba, and ...to identify possible Cuban founder mutations, we conducted a study of unselected breast cancer patients from Havana, Cuba. We enrolled 336 women with breast cancer from a large public hospital in the city. A family history of cancer was obtained from each patient and a blood sample was processed for DNA analysis. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques, but all mutations were confirmed by direct sequencing. We were able to successfully complete testing on samples from 307 women. Among these, eight mutations were identified (seven in BRCA2 and one in BRCA1) representing 2.6% of the total, including 10% of familial cases and 10% of cases under age forty. One BRCA2 mutation (c.3394C > T) was found in two women, but no clear example of a founder mutation was identified. In summary, BRCA1 and BRCA2 mutations are not uncommon in Cuban women with breast cancer, but the absence of founder mutations precludes the development of a rapid and inexpensive clinical screening test.
Internal stresses due to anisotropic thermal and plastic properties were investigated in rolled α‐titanium. The thermal stresses induced by a cooling process were predicted using a self‐consistent ...model and compared with experimental results obtained by X‐ray diffraction. A study of the elastoplastic response after uniaxial loading was performed along the rolling and the transverse direction of the sheet. Using an elastoplastic self‐consistent model, the predicted results were compared with X‐ray diffraction and mechanical tests. Theoretical and experimental results agree in their tendencies. The comparison between εϕψ versus sin2 ψ and simulations confirms that prismatic slip is the main active deformation mode.
O objetivo do estudo foi comparar três testadores (híbrido triplo Zélia, híbrido simples IAC 112 e composto CMS 43) para a avaliação da capacidade de combinação de 36 famílias S2 de milho-pipoca ...provenientes de CMS 43. As famílias foram avaliadas por seu desempenho per se e em seus cruzamentos com os testadores (topcrosses) por meio de quatro látices 6 x 6, com três repetições, instalados na Fazenda Experimental da Universidade Estadual de Maringá, em Iguatemi - PR, durante as épocas de ‘safrinha’ de 2001 e safra normal de 2001/2002. As capacidades geral e específica de combinação foram estimadas segundo o modelo dialélico parcial. Foram estimadas as heteroses dos topcrosses em relação à média de cada testador, bem como as correlações entre o desempenho das famílias e dos seus respectivos topcrosses. O testador mais apropriado, tanto para rendimento de grãos como para capacidade de expansão, foi o híbrido triplo Zélia na ‘safrinha’, e o testador CMS 43 para as duas características, na safra normal.
The aim of the present study was to compare three testers (three-way hybrid Zélia, single cross hybrid IAC 112 and composite CMS 43) for evaluating general and specific combining ability of thirty ...six S2 popcorn families obtained from CMS 43. Families were evaluated considering per se and topcrosses performances, in four 6X6 lattices, with three replications. Trials were carried out in the experimental field at Universidade Estadual de Maringá, in Iguatemi, Paraná, in the years 2001 and 2002. General and specific combining ability were estimated following the partial diallel model. Heterosis of topcrosses in relation to the mean of each tester as well as the correlation between families performances and respective topcrosses were estimated. Correlation estimates were obtained among four sets of means: the S2 families and the three topcrosses sets. Results showed that the more appropriate testers for grain yield and popping expansion were Zélia in 2001 and CMS 43 in 2002.
The X-linked SRPX2 gene encodes a Sushi Repeat-containing Protein of unknown function and is mutated in two disorders of the Rolandic/Sylvian speech areas. Since it is linked to defects in the ...functioning and the development of brain areas for speech production, SRPX2 may thus have participated in the adaptive organization of such brain regions. To address this issue, we have examined the recent molecular evolution of the SRPX2 gene.
The complete coding region was sequenced in 24 human X chromosomes from worldwide populations and in six representative nonhuman primate species. One single, fixed amino acid change (R75K) has been specifically incorporated in human SRPX2 since the human-chimpanzee split. The R75K substitution occurred in the first sushi domain of SRPX2, only three amino acid residues away from a previously reported disease-causing mutation (Y72S). Three-dimensional structural modeling of the first sushi domain revealed that Y72 and K75 are both situated in the hypervariable loop that is usually implicated in protein-protein interactions. The side-chain of residue 75 is exposed, and is located within an unusual and SRPX-specific protruding extension to the hypervariable loop. The analysis of non-synonymous/synonymous substitution rate (Ka/Ks) ratio in primates was performed in order to test for positive selection during recent evolution. Using the branch models, the Ka/Ks ratio for the human branch was significantly different (p = 0.027) from that of the other branches. In contrast, the branch-site tests did not reach significance. Genetic analysis was also performed by sequencing 9,908 kilobases (kb) of intronic SRPX2 sequences. Despite low nucleotide diversity, neither the HKA (Hudson-Kreitman-Aguadé) test nor the Tajima's D test reached significance.
The R75K human-specific variation occurred in an important functional loop of the first sushi domain of SRPX2, indicating that this evolutionary mutation may have functional importance; however, positive selection for R75K could not be demonstrated. Nevertheless, our data contribute to the first understanding of molecular evolution of the human SPRX2 gene. Further experiments are now required in order to evaluate the possible consequences of R75K on SRPX2 interactions and functioning.
Microbial transformation of 8:2 fluorotelomer acrylate and methacrylate in aerobic soils Royer, Laurel A; Linda S. LeeauthorDepartment of Agronomy, Purdue University, West Lafayette, IN 47907-2054, United States; Mark H. RussellauthorDuPont Haskell Global Centers for Health and Environmental Sciences, Newark, DE 19714, United States ...
2015
Journal Article
We report four studies that are concerned with the construct validity of the Sentence Verification Technique (SVT) as a measure of reading comprehension. The studies proceed from the assumption that ...readers with greater subject matter expertise should comprehend technical text in their area of expertise better than readers with less subject matter expertise. Experiment 1 had graduate students in psychology, advanced undergraduate psychology majors, and undergraduates who had never had a psychology course, read and take an SVT test on technical psychological text and/or nontechnical book reviews. Experiment 2 measured text comprehension of the technical and nontechnical text at the beginning and end of a semester psychology course. Experiment 3 evaluated whether the text comprehension of readers who varied in level of expertise would be influenced by Kintschian text structure variables. Experiment 4 tested whether the SVT was a measure of sentence comprehension or a measure of passage comprehension. The results of these studies were consistent with the interpretation that the SVT is a measure of text comprehension.
The 4MOST consortium is currently halfway through a Conceptual Design study for ESO with the aim to develop a wide-field (>3 square degree, goal >5 square degree), high-multiplex (>1500 fibres, goal ...3000 fibres) spectroscopic survey facility for an ESO 4m-class telescope (VISTA). 4MOST will run permanently on the telescope to perform a 5 year public survey yielding more than 20 million spectra at resolution R~5000 ({\lambda}=390-1000 nm) and more than 2 million spectra at R~20,000 (395-456.5 nm & 587-673 nm). The 4MOST design is especially intended to complement three key all-sky, space-based observatories of prime European interest: Gaia, eROSITA and Euclid. Initial design and performance estimates for the wide-field corrector concepts are presented. We consider two fibre positioner concepts, a well-known Phi-Theta system and a new R-Theta concept with a large patrol area. The spectrographs are fixed configuration two-arm spectrographs, with dedicated spectrographs for the high- and low-resolution. A full facility simulator is being developed to guide trade-off decisions regarding the optimal field-of-view, number of fibres needed, and the relative fraction of high-to-low resolution fibres. Mock catalogues with template spectra from seven Design Reference Surveys are simulated to verify the science requirements of 4MOST. The 4MOST consortium aims to deliver the full 4MOST facility by the end of 2018 and start delivering high-level data products for both consortium and ESO community targets a year later with yearly increments.
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