2,386 research outputs found
Fracture energy of coarse recycled aggregate concrete using the wedge splitting test method: influence of water-reducing admixtures
The aim of this study is to evaluate the effect of the replacement levels of coarse natural aggregates with recycled aggregates and water-reducing admixtures on the fracture energy of concrete. Four mixes with 0, 20, 50 and 100% replacement ratios are produced per concrete family: without admixture, with plasticizer and with superplasticizer. The experimental fracture energy is tested using the wedge splitting test method on notched specimens at 28 days. The results prove that the incorporation of up to 20% coarse recycled aggregates led to improved energy absorption capacity of concrete mixes with water-reducing admixtures, reaching 1.5% for concrete with normal plasticizer and 7.0% for concrete with superplasticizer. Furthermore, the compressive strength, slump, and fresh density are tested in order to evaluate the effect of water-reducing admixtures on recycled aggregate concrete with different ratios of coarse natural aggregate replacement, allowing to conclude that the use of plasticizers and superplasticizers improves the behaviour of recycled aggregate concrete for all these properties
Multiaperture Photometry of Galaxies in the Coma Cluster
We present a set of photometry for 745 band selected
objects in a region centered on the core of the Coma
cluster. This includes 516 galaxies and is at least 80% complete to H=16, with
a spectroscopically complete sample of 111 cluster members (nearly all with
morphological classification) for . For each object we present total
\cite{kron80} magnitudes and aperture photometry. As an example, we use these
data to derive color-magnitude relations for Coma early-type galaxies, measure
the intrinsic scatter of these relations and its dependence on galaxy mass, and
address the issue of color gradients. We find that the color gradients are mild
and that the intrinsic scatter about the color-magnitude relation is small
( mag in and less than in , or ).
There is no evidence that the intrinsic scatter varies with galaxy luminosity,
suggesting that the cluster red sequence is established at early epochs over a
range of in stellar mass.Comment: 41 pages, 5 figures, 18 data tables attached to source files or
available on request from R. De propris. Accepted for publication in
Astrophysical Journal Supplement Serie
Harmonized-Multinational qEEG Norms (HarMNqEEG)
This paper extends the frequency domain quantitative electroencephalography (qEEG) methods pursuing higher sensitivity to detect Brain Developmental Disorders. Prior qEEG work lacked integration of cross-spectral information omitting important functional connectivity descriptors. Lack of geographical diversity precluded accounting for site-specific variance, increasing qEEG nuisance variance. We ameliorate these weaknesses. i) Create lifespan Riemannian multinational qEEG norms for cross-spectral tensors. These norms result from the HarMNqEEG project fostered by the Global Brain Consortium. We calculate the norms with data from 9 countries, 12 devices, and 14 studies, including 1564 subjects. Instead of raw data, only anonymized metadata and EEG cross-spectral tensors were shared. After visual and automatic quality control, developmental equations for the mean and standard deviation of qEEG traditional and Riemannian DPs were calculated using additive mixed-effects models. We demonstrate qEEG "batch effects" and provide methods to calculate harmonized z-scores. ii) We also show that the multinational harmonized Riemannian norms produce z-scores with increased diagnostic accuracy to predict brain dysfunction at school-age produced by malnutrition only in the first year of life. iii) We offer open code and data to calculate different individual z-scores from the HarMNqEEG dataset. These results contribute to developing bias-free, low-cost neuroimaging technologies applicable in various health settings
CRIRES-POP: A library of high resolution spectra in the near-infrared
New instrumental capabilities and the wealth of astrophysical information
extractable from the near-infrared wavelength region have led to a growing
interest in the field of high resolution spectroscopy at 1-5 mu. We aim to
provide a library of observed high-resolution and high signal-to-noise-ratio
near-infrared spectra of stars of various types throughout the
Hertzsprung-Russell diagram. This is needed for the exploration of spectral
features in this wavelength range and for comparison of reference targets with
observations and models.
High quality spectra were obtained using the CRIRES near-infrared
spectrograph at ESO's VLT covering the range from 0.97 to 5.3 mu at high
spectral resolution. Accurate wavelength calibration and correction for of
telluric lines were performed by fitting synthetic transmission spectra for the
Earth's atmosphere to each spectrum individually. We describe the observational
strategy and the current status and content of the library which includes 13
objects. The first examples of finally reduced spectra are presented. This
publication will serve as a reference paper to introduce the library to the
community and explore the extensive amount of material.Comment: accepted for publication in A&A; see also the project webpage
http://www.univie.ac.at/crirespo
Common genetic variation in the Estrogen Receptor Beta (ESR2) gene and osteoarthritis: results of a meta-analysis
Background: The objective of this study was to examine the relationship between common genetic variation of the ESR2 gene and osteoarthritis.Methods: In the discovery study, the Rotterdam Study-I, 7 single nucleotide polymorphisms (SNPs) were genotyped and tested for association with hip (284 cases, 2772 controls), knee (665 cases, 2075 controls), and hand OA (874 cases, 2184 controls) using an additive model. In the replication stage one SNP (rs1256031) was tested in an additional 2080 hip, 1318 knee and 557 hand OA cases and 4001, 2631 and 1699 controls respectively. Fixed- and random-effects meta-analyses were performed over the complete dataset including 2364 hip, 1983 knee and 1431 hand OA cases and approximately 6000 controls.Results: The C allele of rs1256031 was associated with a 36% increased odds of hip OA in women of the Rotterdam Study-I (OR 1.36, 95% CI 1.08-1.70, p = 0.009). Haplotype analysis and analysis of knee- and hand OA did not give additional information. With the replication studies, the meta-analysis did not show a significant effect of this SNP on hip OA in the total population (OR 1.06, 95% CI 0.99-1.15, p = 0.10). Stratification according to gender did not change the results. In this study, we had 80% power to detect an odds ratio of at least 1.14 for hip OA (α = 0.05).Conclusion: This study showed that common genetic variation in the ESR2 gene is not likely to influence the risk of osteoarthritis with effects smaller than a 13% increase
Differential Role of Human Choline Kinase α and β Enzymes in Lipid Metabolism: Implications in Cancer Onset and Treatment
11 pages, 6 figures, 1 table.Background
The Kennedy pathway generates phosphocoline and phosphoethanolamine through its two branches. Choline Kinase (ChoK) is the first enzyme of the Kennedy branch of synthesis of 1phosphocholine, the major component of the plasma membrane. ChoK family of proteins is composed by ChoKα and ChoKβ isoforms, the first one with two different variants of splicing. Recently ChoKα has been implicated in the carcinogenic process, since it is over-expressed in a variety of human cancers. However, no evidence for a role of ChoKβ in carcinogenesis has been reported.
Methodology/Principal Findings
Here we compare the in vitro and in vivo properties of ChoKα1 and ChoKβ in lipid metabolism, and their potential role in carcinogenesis. Both ChoKα1 and ChoKβ showed choline and ethanolamine kinase activities when assayed in cell extracts, though with different affinity for their substrates. However, they behave differentially when overexpressed in whole cells. Whereas ChoKβ display an ethanolamine kinase role, ChoKα1 present a dual choline/ethanolamine kinase role, suggesting the involvement of each ChoK isoform in distinct biochemical pathways under in vivo conditions. In addition, while overexpression of ChoKα1 is oncogenic when overexpressed in HEK293T or MDCK cells, ChoKβ overexpression is not sufficient to induce in vitro cell transformation nor in vivo tumor growth. Furthermore, a significant upregulation of ChoKα1 mRNA levels in a panel of breast and lung cancer cell lines was found, but no changes in ChoKβ mRNA levels were observed. Finally, MN58b, a previously described potent inhibitor of ChoK with in vivo antitumoral activity, shows more than 20-fold higher efficiency towards ChoKα1 than ChoKβ.
Conclusion/Significance
This study represents the first evidence of the distinct metabolic role of ChoKα and ChoKβ isoforms, suggesting different physiological roles and implications in human carcinogenesis. These findings constitute a step forward in the design of an antitumoral strategy based on ChoK inhibition.This work has been supported by grants to JCL from Comunidad de Madrid (GR-SAL-0821-2004), Ministerio de Ciencia e Innovación (SAF2008-03750, RD06/0020/0016), Fundación Mutua Madrileña, and by a grant to ARM from Fundación Mutua Madrileña.Peer reviewe
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