6,393 research outputs found
Enhancement of the advanced Fenton process (Fe0/H2O2) by ultrasound for the mineralization of phenol
In this study, a successful mineralization of phenol was achieved by means of coupling zero-valent iron (ZVI) particles, hydrogen peroxide and a short input of ultrasonic irradiation. This short sono-advanced Fenton process (AFP) provided a better performance of ZVI in a subsequent silent degradation stage, which involves neither extra cost of energy nor additional oxidant. The short input of ultrasound (US) irradiation enhanced the activity of the Fe0/H2O2 system in terms of the total organic carbon (TOC) removal. Then, the TOC mineralization continued during the silent stage, even after the total consumption of hydrogen peroxide, reaching values of ca. 90% TOC conversions over 24 h. This remarkable activity is attributed to the capacity of the ZVI/iron oxide composite formed during the degradation for the generation of oxidizing radical species and to the formation of another reactive oxidant species, such as the ferryl ion. The modification of the initial conditions of the sono-AFP system such as the ultrasonic irradiation time and the hydrogen peroxide dosage, showed significant variations in terms of TOC mineralization for the ongoing silent degradation stage. An appropriate selection of operation conditions will lead to an economical and highly efficient technology with eventual large-scale commercial applications for the degradation organic pollutants in aqueous effluents
A Morphological Diagnostic for Dynamical Evolution of Wolf-Rayet Bubbles
We have observed H-alpha and [OIII] emission from eight of the most well
defined Wolf-Rayet ring nebulae in the Galaxy. We find that in many cases the
outermost edge of the [OIII] emission leads the H-alpha emission. We suggest
that these offsets, when present, are due to the shock from the Wolf-Rayet
bubble expanding into the circumstellar envelope. Thus, the details of the WR
bubble morphology at H-alpha and [OIII] can then be used to better understand
the physical condition and evolutionary stage of the nebulae around Wolf-Rayet
stars, as well as place constraints on the nature of the stellar progenitor and
its mass loss history.Comment: 11 pages, LaTex, 8 figures, accepted for publication in AJ, November
200
The Tousled-like kinases regulate genome and epigenome stability: implications in development and disease
The Tousled-like kinases (TLKs) are an evolutionarily conserved family of serine–threonine kinases that have been implicated in DNA replication, DNA repair, transcription, chromatin structure, viral latency, cell cycle checkpoint control and chromosomal stability in various organisms. The functions of the TLKs appear to depend largely on their ability to regulate the H3/H4 histone chaperone ASF1, although numerous TLK substrates have been proposed. Over the last few years, a clearer picture of TLK function has emerged through the identification of new partners, the definition of specific roles in development and the elucidation of their structural and biochemical properties. In addition, the TLKs have been clearly linked to human disease; both TLK1 and TLK2 are frequently amplified in human cancers and TLK2 mutations have been identified in patients with neurodevelopmental disorders characterized by intellectual disability (ID), autism spectrum disorder (ASD) and microcephaly. A better understanding of the substrates, regulation and diverse roles of the TLKs is needed to understand their functions in neurodevelopment and determine if they are viable targets for cancer therapy. In this review, we will summarize current knowledge of TLK biology and its potential implications in developmen
The industrial machinery collection of the Alcoy City Council
S’hi presenta el catà leg d’una col·lecció de maquinà ria industrial que va tenir el seu origen en l’Escola Università ria d’Enginyeria Tècnica Industrial
d’Alcoi, ampliada amb posterioritat per donacions d’empreses i particulars, i en l’actualitat custodiada per l’Ajuntament d’Alcoi.
El conjunt supera el centenar d’artefactes representatius de l’activitat fabril alcoiana: tèxtil, paperera, metal·lúrgica, energètica, etc., dels segles XIX
i XX.
Paraules clau: Catalogació. Maquinà ria industrial. Processos industrials. Segles XIX i XX. Alcoi (Alacant).We present the catalogue of a collection of industrial machinery which originated at the School of Industrial Engineering of Alcoy, subsequently enlarged
by donations from businesses and individuals. The collection is currently being held by the Alcoy City Council.
The whole collection is made up of more than one hundred artifacts representative of the manufacturing activity in Alcoy: textile, papermarking, metallurgy,
energy, etc., dating from the XIX and XX centuries.
Key words: Cataloguing. Industrial machinery. Industrial processes. XIX and XX centuries. Alcoy (Alicante, Spain)., Spain).Se presenta el catálogo de una colección de maquinaria industrial que tuvo su origen en la Escuela Universitaria de IngenierÃa Técnica Industrial de
Alcoy, ampliada con posterioridad por donaciones de empresas y particulares, y en la actualidad custodiada por el Ayuntamiento de Alcoy.
El conjunto supera el centenar de artefactos representativos de la actividad fabril alcoyana: textil, papelera, metalúrgica, energética, etc., de los siglos
XIX y XX.
Palabras clave: Catalogación. Maquinaria industrial. Procesos industriales. Siglos XIX y XX. Alcoy (Alicante)
Clouds in the atmospheres of extrasolar planets. II. Thermal emission spectra of Earth-like planets influenced by low and high-level clouds
We study the impact of multi-layered clouds (low-level water and high-level
ice clouds) on the thermal emission spectra of Earth-like planets orbiting
different types of stars. Clouds have an important influence on such planetary
emission spectra due to their wavelength dependent absorption and scattering
properties. We also investigate the influence of clouds on the ability to
derive information about planetary surface temperatures from low-resolution
spectra.Comment: accepted for publication in A&
High-pressure study of substrate material ScAlMgO4
We report on the structural properties of ScAlMgO4 studied under
quasi-hydrostatic pressure using synchrotron high-pressure x-ray diffraction up
to 40 GPa. We also report on single-crystal studies of ScAlMgO4 performed at
300 K and 100 K. We found that the low-pressure phase remains stable up to 24
GPa. At 28 GPa, we detected a reversible phase transformation. The
high-pressure phase is assigned to a monoclinic distortion of the low-pressure
phase. No additional phase transition is observed up to 40 GPa. In addition,
the equation of state, compressibility tensor, and thermal expansion
coefficients of ScAlMgO4 are determined. The bulk modulus of ScAlMgO4 is found
to be 143(8) GPa, with a strong compressibility anisotropy. For the trigonal
low-pressure phase, the compressibility along the c-axis is twice than
perpendicular one. A perfect lattice match with ZnO is retained under pressure
in the pressure range of stability of wurtzite ZnO.Comment: 22 pages, 5 figures, 4 tables, 24 reference
Predictive modelling using pathway scores: robustness and significance of pathway collections
Background Transcriptomic data is often used to build statistical models which are predictive of a given phenotype, such as disease status. Genes work together in pathways and it is widely thought that pathway representations will be more robust to noise in the gene expression levels. We aimed to test this hypothesis by constructing models based on either genes alone, or based on sample specific scores for each pathway, thus transforming the data to a ‘pathway space’. We progressively degraded the raw data by addition of noise and examined the ability of the models to maintain predictivity. Results Models in the pathway space indeed had higher predictive robustness than models in the gene space. This result was independent of the workflow, parameters, classifier and data set used. Surprisingly, randomised pathway mappings produced models of similar accuracy and robustness to true mappings, suggesting that the success of pathway space models is not conferred by the specific definitions of the pathway. Instead, predictive models built on the true pathway mappings led to prediction rules with fewer influential pathways than those built on randomised pathways. The extent of this effect was used to differentiate pathway collections coming from a variety of widely used pathway databases. Conclusions Prediction models based on pathway scores are more robust to degradation of gene expression information than the equivalent models based on ungrouped genes. While models based on true pathway scores are not more robust or accurate than those based on randomised pathways, true pathways produced simpler prediction rules, emphasizing a smaller number of pathways
Phylogenetic Patterns in Montane Troglodytes Wrens
Phylogenetic studies based on mitochondrial DNA sequences of 10 species of wrens in Troglodytes and related genera suggest a new hypothesis of relationships for the group. The Winter Wren (T. troglodytes) and the anomalous Timberline Wren (Thryorchilus browni) are distantly related to the remainder of Troglodytes. The latter group divides into a tropical montane group and a northern/lowland group that includes the northernmost two montane taxa (T. rufociliatus, T. brunneicollis). Erection of the genus Nannus for the Winter Wren is proposed. Song evolution in the complex has involved either convergent derivation or retention of primitive song types in distant lineages
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