568 research outputs found
Recursive POD expansion for the advection-diffusion-reaction equation
This paper deals with the approximation of advection-diffusion-reaction
equation solution by reduced order methods. We use the Recursive POD approximation for multivariate functions introduced in [M. AZAÏEZ, F. BEN BELGACEM, T. CHACÓN REBOLLO, Recursive POD expansion for reactiondiffusion equation, Adv.Model. and Simul. in Eng. Sci. (2016) 3:3. DOI 10.1186/s40323-016-0060-1] and applied to the low tensor representation
of the solution of the reaction-diffusion partial differential equation. In this
contribution we extend the Recursive POD approximation for multivariate functions with an arbitrary number of parameters, for which we prove general error estimates. The method is used to approximate the solutions of the advection-diffusion-reaction equation. We prove spectral error estimates, in which the spectral convergence rate depends only on the diffusion interval, while the error estimates are affected by a factor that grows exponentially with the advection velocity, and are independent of the reaction rate if this lives in a bounded set. These error estimates are based upon the analyticity of the solution of these equations as a function of the parameters (advection
velocity, diffusion, reaction rate). We present several numerical tests, strongly consistent with the theoretical error estimates.Ministerio de Economía y CompetitividadAgence nationale de la rechercheGruppo Nazionale per il Calcolo ScientificoUE ERA-PLANE
Dynamics of a suspended nanowire driven by an ac Josephson current in an inhomogeneous magnetic field
We consider a voltage-biased nanoelectromechanical Josephson junction, where
a suspended nanowire forms a superconducting weak-link, in an inhomogeneous
magnetic field. We show that a nonlinear coupling between the Josephson current
and the magnetic field generates a Laplace force that induces a whirling motion
of the nanowire. By performing an analytical and a numerical analysis, we
demonstrate that at resonance, the amplitude-phase dynamics of the whirling
movement present different regimes depending on the degree of inhomogeneity of
the magnetic field: time independent, periodic and chaotic. Transitions between
these regimes are also discussed.Comment: 7 pages, 5 figure
The Interaction between the Forkhead Thyroid Transcription Factor TTF-2 and the Constitutive Factor CTF/NF-1 Is Required for Efficient Hormonal Regulation of the Thyroperoxidase Gene Transcription
The forkhead thyroid-specific transcription factor TTF-2 is the main mediator of thyrotropin and insulin regulation of thyroperoxidase (TPO) gene expression. This function depends on multimerization and specific orientation of its DNA-binding site, suggesting that TTF-2 is part of a complex interaction network within the TPO promoter. This was confirmed by transfection experiments and by protein-DNA interaction studies, which demonstrated that CTF/NF1 proteins bind 10 base pairs upstream of the TTF-2- binding site to enhance its action in hormone-induced expression of the TPO gene. GST pull-down assays showed that TTF-2 physically interacts with CTF/NF1 proteins. In addition, we demonstrate that increasing the distance between both transcription factors binding sites by base pair insertion results in loss of promoter activity and in a drastic decrease on the ability of the promoter to respond to the hormones. CTF/NF1 is a family of transcription factors that contributes to constitutive and cell-type specific gene expression. Originally identified as factors implicated in the replication of adenovirus, this group of proteins (CTF/NF1-A, -B, -C, and - X) is now known to be involved in the regulation of several genes. In contrast to other reports regarding the involvement of these proteins in inducible gene expression, we show here that members of this family of transcription factors are regulated by hormones. With the use of specific CTF/NF1 DNA probes and antibodies we demonstrate that CTF/NF1-C is a thyrotropin-, cAMP-, and insulin-inducible protein. Thus CTF/NF1 proteins do not only mediate hormone-induced gene expression cooperating with TTF-2, but are themselves hormonally regulated. All these findings are clearly of important value in understanding the mechanisms governing the transcription regulation of RNA polymerase II promoters, which often contain binding sites for multiple transcription factors
Nutritional status, energy and protein consumption among primary schoolchildren in Pulau Mantanani, Kota Belud, Sabah
This study was conducted in April 2007 in Pulau Mantanani, an isolated island northwest of
Kota Belud, 80 km north of Kota Kinabalu. Forty-six schoolchildren, boys and girls aged 10, 11 and
12 were included in the study. Anthropometric measurements were taken and compared with the
growth charts of the National Centre for Health Statistics. Food consumption based on the 24-
hours dietary recall was recorded and calculated using the NutriCal software. It was interesting to
know that despite the acceptable protein consumption, the growth indicators showed otherwise.
Results showed that 50.0% of the children were stunted (<-2 standard deviation of height for age),
52.2% were underweight (<-2 standard deviation of weight for age) and 17.4% were wasted (<-2
standard deviation of weight for height). 2.2% had a energy consumption of less than 1/3 of the
Recommended Nutrient Intake (RNI) for Malaysia, 43.5% consumed energy between 1/3-2/3 of
the RNI whereas 41.3% consumed between 2/3 to 100% of the RNI while 13% consumed energy
more than the RNI. As for protein intake, 39.1% children had protein intake below the RNI.
However, there was no significant correlation between growth indicators and energy consumption.
In conclusion, this study showed poor nutritional status of the children as shown by the growth
indicators. Energy intake was also inadequate among the majority of the children although protein
consumption was higher than the RNI by 2/3 of the subjects
A -Topological Index for Free-Fermion Systems in Disordered Media
We use infinite dimensional self--dual -algebras to
study a -index, which classifies free--fermion systems embedded
on -index disordered lattices. Combes-Thomas estimates are
pivotal to show that the -index is uniform with respect to the
size of the system. We additionally deal with the set of ground states to
completely describe the mathematical structure of the underlying system.
Furthermore, the weak--topology of the set of linear functionals is used
to analyze paths connecting different sets of ground states.Comment: 38 pages, typos corrected, references adde
Regional differences in AIDS and non-AIDS related mortality in HIV-positive individuals across Europe and Argentina: the EuroSIDA study
BACKGROUND
Differences in access to care and treatment have been reported in Eastern Europe, a region with one of the fastest growing HIV epidemics, compared to the rest of Europe. This analysis aimed to establish whether there are regional differences in the mortality rate of HIV-positive individuals across Europe, and Argentina.
METHODS
13,310 individuals under follow-up were included in the analysis. Poisson regression investigated factors associated with the risk of death.
FINDINGS
During 82,212 person years of follow-up (PYFU) 1,147 individuals died (mortality rate 14.0 per 1,000 PYFU (95% confidence interval [CI] 13.1-14.8). Significant differences between regions were seen in the rate of all-cause, AIDS and non-AIDS related mortality (global p<0.0001 for all three endpoints). Compared to South Europe, after adjusting for baseline demographics, laboratory measurements and treatment, a higher rate of AIDS related mortality was observed in East Europe (IRR 2.90, 95%CI 1.97-4.28, p<.0001), and a higher rate of non-AIDS related mortality in North Europe (IRR 1.51, 95%CI 1.24-1.82, p<.0001). The differences observed in North Europe decreased over calendar-time, in 2009-2011, the higher rate of non-AIDS related mortality was no longer significantly different to South Europe (IRR 1.07, 95%CI 0.66-1.75, p = 0.77). However, in 2009-2011, there remained a higher rate of AIDS-related mortality (IRR 2.41, 95%CI 1.11-5.25, p = 0.02) in East Europe compared to South Europe in adjusted analysis.
INTERPRETATIONS
There are significant differences in the rate of all-cause mortality among HIV-positive individuals across different regions of Europe and Argentina. Individuals in Eastern Europe had an increased risk of mortality from AIDS related causes and individuals in North Europe had the highest rate of non-AIDS related mortality. These findings are important for understanding and reviewing HIV treatment strategies and policies across the European region
Examining the suitability of the list of indicators describing age-related typical support needs
Producción CientíficaThe list of indicators is a form of training material used for the Supports Intensity Scale—Children’s version (SIS-C). It is aimed at helping interviewers distinguishing between extraordinary and age-related typical support needs in children with intellectual and developmental disabilities (IDD) when implementing the SIS-C, and thus improve supports planning. The aim of this study is to adapt and test the list of indicators’ content validity and rating scale’s functioning in Spain. A total of 222 general education teachers reported their agreement with each indicator description using a 5-point rating scale. A total of 353 of 366 indicators showed evidence of content validity, whereas analyses on the rating scale highlighted the necessity of subsuming one of the scale categories within another. The need for developing research-based training materials to develop training programs on the use of the SIS-C to support decision-making concerning supports planning with students with IDD, the relevance of using the latest methodological approaches available when required, and future lines of research are discussed.Unión Europea Programa Erasmus - (grant 2017-3338/001-001 (project 592127-EPP-1-2017-1-BE-EPPKA3-IPI-SOC IN)Ministerio de Economía y Competitividad - (grant BES-2016-078252)Ministerio de Economía y Competitividad y Fondo Europeo de Desarrollo Regional (FEDER) - (Grant PID2019-110127GB-100
Synthesis, characterization, bioactivity and biocompatibility of nanostructured materials based on the wollastonite-poly(ethylmethacrylate-co-vinylpyrrolidone) system
Composite materials are very promising biomaterials
for hard tissue augmentation. The approach assayed
in this work involves the manufacturing of a composite
made of a bioactive ceramic, natural wollastonite (W) and a
nanostructured copolymer of ethylmethacrylate (EMA) and
vinylpyrrolidone (VP) to yield a bioresorbable and biocompatible
VP–EMA copolymer. A bulk polymerization was
induced thermally at 508C, using 1 wt % azobis(isobutyronitrile)
(AIBN) as free-radical initiator. Structural characterization,
compressive strength, flexural strength (FS), degradation,
bioactivity, and biocompatibility were evaluated in
specimens with a 60/40 VP/EMA ratio and ceramic content
in the range 0–60%. A good integration between phases
was achieved. Greater compression and FS, in comparison
with the pure copolymer specimens was obtained only
when the ceramic load got up to 60% of the total weight.
The soaking in NaCl solution resulted in the initial swelling
of the specimens tested. The maximum swelling was
reached after 2–3 h of immersion and it was significantly
greater for lower ceramic loads. This result makes the polymer
component the main responsible for the interactions
with the media. After soaking in SBF, microdomains segregation
can be observed in the polymer component that can
be related with a dramatic difference in the reactivity of
both monomers in free radical polymerization, whereas the
formation of an apatite-like layer on the W surfaces can be
observed. Biocompatibility in vitro studies showed the absence
of cytotoxicity of all formulations. The cells were able
to adhere on the polystyrene negative control and on specimens
containing 60 wt % wollastonite forming a monolayer
and showing a normal morphology. However, a low cellular
growth was observed. 2008 Wiley Periodicals, Inc.
J Biomed Mater Res 88A: 53–64, 2009Peer reviewe
The cultural and geopolitical dimensions of nation-building in the Ukraine
Ukraine belongs among those young countries where the beginnings of democratisation and nation-building approximately coincided. While the development of nation states in Central Europe was usually preceded by the development of nations, the biggest dilemma in the Ukraine is whether a nation-state programme — parallel to the aim of state-building — is able to bring unfinished nation-building to completion. Ukraine sways between the EU and Russia with enormous amplitude. The alternating orientation between the West and the East can be ascribed to superpower ambitions reaching beyond Ukraine. Eventually, internal and external determinants are intertwined and mutually interact with one another. The aim of the paper is to explain the dilemmas arising from identity problems behind the Ukraine’s internal and external orientation
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