174 research outputs found
Flow Equations for Non-BPS Extremal Black Holes
We exploit some common features of black hole and domain wall solutions of
(super)gravity theories coupled to scalar fields and construct a class of
stable extremal black holes that are non-BPS, but still can be described by
first-order differential equations. These are driven by a "superpotential'',
which replaces the central charge Z in the usual black hole potential. We
provide a general procedure for finding this class and deriving the associated
"superpotential''. We also identify some other cases which do not belong to
this class, but show a similar behaviour.Comment: LaTeX, 21 pages, 2 figures. v2: reference added, JHEP versio
Age-Related Differences in Restricted Repetitive Behaviors in Autism Spectrum Disorders
Restricted repetitive behaviors (RRBs) were examined in a large group of children, adolescents and adults with ASD in order to describe age-related patterns of symptom change and association with specific contextual factors, and to examine if the patterns of change are different for the various types of RRBs. Over 700 individuals with ASD were rated on the Repetitive Behavior Scale – Revised. RRBs were less frequent and less severe among older than younger individuals, corroborating that autism symptoms abate with age. Our findings further suggest that repetitive behaviors are a heterogeneous group of behaviors, with the subtypes of RRBs having their own individual patterns across the lifespan, and in some cases, a differential association with age depending on intellectual functioning
Modelling the effect of picloram on the growth kinetics of cell suspension cultures of Ficus deltoidea L.
Ficus deltoidea (or commonly known as mistletoe fig) in various parts of the world mainly serves as an ornamental shrub or houseplant and found native mainly in Asia tropical region, for example, Malaysia, Indonesia, Philippines and Thailand. Studies on the effect of plant growth regulators on cells production from this plant is important as optimization of cells production can lead to efficient production of secondary products characterization and production. An important aspect of the sigmoidal cells growth curve is the growth parameters. In this work, we model the effect of picloram (4-amino-3,5,6-trichloropicolinic acid) on the growth kinetics of the cell suspension cultures of Ficus deltoidea according to the modified Gompertz model. The adjusted coefficient of determination showed good agreement between experimental and predicted data with values ranging from 0.97-0.99. Parameters obtained from the fitting exercise were maximum cells growth rate (µm), lag time (λ) and maximal cells production (Ymax). The results showed that picloram at concentrations of 3 mg/L and above were optimal for giving the highest cells growth rate measured as PCV (packed cell volume). The parameter growth rate obtained from the modelling exercise will be helpful for additional secondary modelling implicating the consequence of media conditions as well as other factors on the effect of picloram on the growth rate of cell suspension from this plant
Analysis of a spatial Lotka-Volterra model with a finite range predator-prey interaction
We perform an analysis of a recent spatial version of the classical
Lotka-Volterra model, where a finite scale controls individuals' interaction.
We study the behavior of the predator-prey dynamics in physical spaces higher
than one, showing how spatial patterns can emerge for some values of the
interaction range and of the diffusion parameter.Comment: 7 pages, 7 figure
Fault-controlled and stratabound Dolostones in the Late Aptian-earliest Albian Benassal Formation (Maestrat Basin, E Spain): petrology and geochemistry constrains
Fault-controlled hydrothermal dolomitization of the Late Aptian to earliest Albian Benassal Fm shallow water carbonates resulted in the seismic-scale stratabound dolostone geobodies that characterize the Benicàssim case study (Maestrat Basin, E Spain). Petrological and geochemical data indicate that dolomite cement (DC1) filling intergranular porosity in grain-dominated facies constituted the initial stage of dolomitization. The bulk of the dolostone is formed by a replacive nonplanar-a to planar-s dolomite (RD1) crystal mosaic with very low porosity and characteristic retentive fabric. Neomorphic recrystallization of RD1 to form replacive dolomite RD2 occurred by successive dolomitizing fluid flow. The replacement sequence DC1-RD1-RD2 is characterized by a depletion in the oxygen isotopic composition (mean δ18O(V-PDB) values from −6.92, to −8.55, to −9.86¿), which is interpreted to result from progressively higher temperature fluids. Clear dolomite overgrowths (overdolomitization) precipitated during the last stage of replacement. Strontium isotopic composition suggests that the most likely origin of magnesium was Cretaceous seawater-derived brines that were heated and enriched in radiogenic strontium and iron while circulating through the Paleozoic basement and/or Permo-Triassic red beds. Burial curves and analytical data indicate that the replacement took place at burial depths between 500 and 750 m, and by hydrothermal fluids exceeding temperatures of 80 °C. Following the partial dolomitization of the host rock, porosity considerably increased in dolostones by burial corrosion related to the circulation of acidic fluids derived from the emplacement of the Mississippi Valley-Type deposits. Overpressured acidic fluids circulated along faults, fractures and open stylolites. Saddle dolomite and ore-stage calcite cement filled most of the newly created vuggy porosity. Subsequent to MVT mineralization, precipitation of calcite cements resulted from the migration of meteoric-derived fluids during uplift and subaerial exposure. This late calcite cement destroyed most of the dolostone porosity and constitutes the main cause for its present day poor reservoir qualit
Vacuum oscillation solution to the solar neutrino problem in standard and non-standard pictures
The neutrino long wavelength (just-so) oscillation is revisited as a solution
to the solar neutrino problem. We consider just-so scenario in various cases:
in the framework of the solar models with relaxed prediction of the boron
neutrino flux, as well as in the presence of the non-standard weak range
interactions between neutrino and matter constituents. We show that the fit of
the experimental data in the just-so scenario is not very good for any
reasonable value of the neutrino flux, but it substantially improves if
the non-standard -neutrino--electron interaction is included. These new
interactions could also remove the conflict of the just-so picture with the
shape of the SN 1987A neutrino spectrum. Special attention is devoted to the
potential of the future real-time solar neutrino detectors as are
Super-Kamiokande, SNO and BOREXINO, which could provide the model independent
tests for the just-so scenario. In particular, these imply specific deformation
of the original solar neutrino energy spectra, and time variation of the
intermediate energy monochromatic neutrino ( and ) signals.Comment: Latex, 14 pages, 9 figures (avalilable by fax or postscript files
requested to [email protected]) -- some textual and Latex errors are corrected
and few references adde
The Upper Aptian to Lower Albian syn-rift carbonate succession of the southern Maestrat Basin (Spain): Facies architecture and fault-controlled stratabound dolostones
Syn-rift shallow-marine carbonates of Late Aptian to Early Albian age in the southern Maestrat Basin (E Spain) register the thickest Aptian sedimentary record of the basin, and one of the most complete carbonate successions of this age reported in the northern Tethyan margin. The host limestones (Benassal Formation) are partially replaced by dolostones providing a new case study of fault-controlled hydrothermal dolomitization. The syn-rift sediments filled a graben controlled by normal basement faults. The Benassal Fm was deposited in a carbonate ramp with scarce siliciclastic input. The lithofacies are mainly characterized by the presence of orbitolinid foraminifera, corals and rudist bivalves fauna. The succession is stacked in three transgressive-regressive sequences (T-R) bounded by surfaces with sequence stratigraphic significance. The third sequence, which is reported for the first time in the basin, is formed by fully marine lithofacies of Albian age and represents the marine equivalent to the continental deposits of the Escucha Fm in the rest of the basin. The dolomitization of the host rock is spatially associated with the basement faults, and thus is fault-controlled. The dolostone forms seismic-scale stratabound tabular geobodies that extend several kilometres away from the fault zones, mostly in the hanging wall blocks, and host Mississippi Valley Type (MVT) deposits. The dolostones preferentially replaced middle to inner ramp grain-dominated facies from the third T-R sequences consisting of bioclastic packestones and peloidal grainstones. Field and petrology data indicate that the replacement took place after early calcite cementation and compaction, most likely during the Late Cretaceous post-rift stage of the basin. The dolostone registers the typical hydrothermal paragenesis constituted by the host limestone replacement, dolomite cementation and sulfide MVT mineralization. The Aptian succession studied provides a stratigraphic framework that can be used for oil exploration in age-equivalent rocks, especially in the València Trough, offshore Spain. Moreover, this new case study constitutes a world class outcrop analogue for similar partially stratabound, dolomitized limestone reservoirs worldwide
Estudi impacte economia col·laborativa en mobilitat : informe relatiu a l'impacte de les modificacions de l'OCVV relatives als VMP sobre el trànsit en carril bici i calçada
Es basa en l'Ordenança de circulació de vianants i de vehicles [1998] : modificació [2015-02-27] [http://hdl.handle.net/11703/86848]Les mencions de responsabilitat s'han basat en els crèdits facilitats per l'àrea responsableEl present informe fa una estimació de l'impacte de les modificacions introduïdes a l'OCVV de Barcelona que regula la circulació dels Vehicles de Mobilitat Personal (VMP
Total urinary polyphenols and ideal cardiovascular health metrics in Spanish adolescents enrolled in the SI Program: a cross-sectional study
To study the relationship between urinary total polyphenol excretion (TPE) in adolescents and ideal cardiovascular (CVH) metrics. 1151 adolescents aged 12.04 (0.46) years participating in the SI! Program for Secondary Schools were selected based on the availability of urine samples and information required to assess CVH metrics. Data on health behaviours (smoking status, body mass index, physical activity, and healthy diet) and health factors (blood pressure, total cholesterol, and blood glucose) were used to calculate the CVH metrics. TPE in urine was analysed by a Folin-Ciocalteu method after solid-phase extraction. Associations between TPE (categorized into tertiles) and CVH metrics (total and separate scores) were assessed using multilevel mixed-effect regression models. Higher TPE levels were associated with higher (healthier) CVH scores and ideal smoking status (OR 1.54, 95% CI 1.10; 1.87, p value = 0.007), physical activity (OR 1.12, 95% CI 1.02; 1.23, p value = 0.022) and total cholesterol (OR 1.78, 95% CI 1.16; 2.73, p value = 0.009) after multivariate adjustment. An association between TPE and total CVH scores was observed only in boys. Girls with higher TPE had higher rates of ideal total cholesterol and blood pressure. According to our findings, higher urinary TPE is related to better CVH scores, with relevant differences in this association by gender
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