122 research outputs found
Consensus formation on a triad scale-free network
Several cases of the Sznajd model of socio-physics, that only a group of
people sharing the same opinion can convince their neighbors, have been
simulated on a more realistic network with a stronger clustering. In addition,
many opinions, instead of usually only two, and a convincing probability have
been also considered. Finally, with minor changes we obtain a vote distribution
in good agreement with reality.Comment: 11 pages including 7 encapsulated postscript (*.eps) figures; to
appear in Physica
Outward-inward information flux in an opinion formation model on different topologies
A simple model of opinion formation dynamics in which binary-state agents
make up their opinions due to the influence of agents in a local neighborhood
is studied using different network topologies. Each agent uses two different
strategies, the Sznajd rule with a probability and the Galam majority rule
(without inertia) otherwise; being a parameter of the system. Initially,
the binary-state agents may have opinions (at random) against or in favor about
a certain topic. The time evolution of the system is studied using different
network topologies, starting from different initial opinion densities. A
transition from consensus in one opinion to the other is found at the same
percentage of initial distribution no matter which type of network is used or
which opinion formation rule is used.Comment: 11 pages including figures. To appear in Physica
Combined update scheme in the Sznajd model
We analyze the Sznajd opinion formation model, where a pair of neighboring
individuals sharing the same opinion on a square lattice convince its six
neighbors to adopt their opinions, when a fraction of the individuals is
updated according to the usual random sequential updating rule (asynchronous
updating), and the other fraction, the simultaneous updating (synchronous
updating). This combined updating scheme provides that the bigger the
synchronous frequency becomes, the more difficult the system reaches a
consensus. Moreover, in the thermodynamic limit, the system needs only a small
fraction of individuals following a different kind of updating rules to present
a non-consensus state as a final state.Comment: 9 pages including figures. To appear in Physica
Interlayer hopping properties of electrons in layered metals
A formalism is proposed to study the electron tunneling between extended
states, based on the spin-boson Hamiltonian previously used in two-level
systems. It is applied to analyze the out--of--plane tunneling in layered
metals considering different models. By studying the effects of in--plane
interactions on the interlayer tunneling of electrons near the Fermi level, we
establish the relation between departure from Fermi liquid behavior driven by
electron correlations inside the layer and the out of plane coherence. Response
functions, directly comparable with experimental data are obtained
Late-time cosmology in (phantom) scalar-tensor theory: dark energy and the cosmic speed-up
We consider late-time cosmology in a (phantom) scalar-tensor theory with an
exponential potential, as a dark energy model with equation of state parameter
close to -1 (a bit above or below this value). Scalar (and also other kinds of)
matter can be easily taken into account. An exact spatially-flat FRW cosmology
is constructed for such theory, which admits (eternal or transient)
acceleration phases for the current universe, in correspondence with
observational results. Some remarks on the possible origin of the phantom,
starting from a more fundamental theory, are also made. It is shown that
quantum gravity effects may prevent (or, at least, delay or soften) the cosmic
doomsday catastrophe associated with the phantom, i.e. the otherwise
unavoidable finite-time future singularity (Big Rip). A novel dark energy model
(higher-derivative scalar-tensor theory) is introduced and it is shown to admit
an effective phantom/quintessence description with a transient acceleration
phase. In this case, gravity favors that an initially insignificant portion of
dark energy becomes dominant over the standard matter/radiation components in
the evolution process.Comment: LaTeX file, 48 pages, discussion of Big Rip is enlarged, a reference
is adde
Associations between insulin resistance and three B-vitamins in european adolescents: The HELENA study
Objective: To assess whether adolescents with high body mass index (BMI), or fat mass index (FMI), in combination with insulin resistance (assessed with the Homeostatic Model Assessment [HOMA] index), had also lower blood vitamin B6, folate and vitamin B12 concentrations. Methods and materials: Six hundred and fifteen adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, with data on B-vitamins (both intakes and status), and BMI, FMI, HOMA, were selected. Intakes were assessed by two non-consecutive 24-h recalls. B-vitamins biomarkers were measured by chromatography and immunoassay. Analysis of covariance was applied to elucidate the differences in B-vitamins between combinations of groups defined according to the median of the z-scores of markers of body composition and insulin sensitivity. Results: When considering energy intakes and education of the mother in the model, in females, vitamin B6 intakes were higher in the high BMI/ high HOMA group than in the high BMI-low HOMA group. Similarly, vitamin B6 intakes were higher in the high FMI/high HOMA group than in the low FMI/low HOMA group. Plasma vitamin B12 was significantly lower in males in the high FMI/high HOMA group than in the low FMI/low HOMA group, keeping also significant their trends throughout the groups, a fact that can be observed also for females (p < 0.05). Conclusion: Adolescents with combined higher adiposity and higher HOMA insulin sensitivity showed lower vitamin B12 plasma concentrations. These differences do not seem to be explained by dietary vitamin B12 intake
Utilización de harina de pimiento morrón (capsicum annuum) en la elaboración de pan artesanal
The use of food wastes to enhance existing products such as breads by their nutritional properties, is a field that has become more popular within the years. Bell peppers (Capsicum annuum) are a rich source of fibre and carotenoids, also the increasing need of these nutrients are vital to reduce and prevent future diseases. Along this article, certain methods are employed in order to obtain the bell pepper flour and a 10 %, 15 % and 20 % substitution of wheat flour for bell pepper flour is made. The products were analysed to obtain their unique characteristics, resulting in the 10 % substitution being the best option for either acceptance and versatility in future markets. It showed a P value of 0.318 in relation to the protein content and a P value of 0.000 in relation to the fibre content.El uso de alimentos de desecho para enriquecer las propiedades de un producto como lo es el pan, mediante sus propiedades nutricionales es un área que ha ganado interés en los últimos años. El pimiento morrón (Capsicum annuum) es una rica fuente de fibra y carotenoides. La necesidad del consumo en los humanos de dichos fitonutrientes ha incrementado debido a sus propiedades preventivas. Diferentes métodos como deshidratación y molienda para la obtención de la harina de pimiento y para una realización de panes con diversos porcentajes de sustitución de harina de trigo común por harina de pimiento son mostrados. Sus características únicas mostraron aquel con un 10 % de sustitución como la mejor opción por su aceptación y versatilidad en futuros mercados. Se obtuvo un P valor de 0.318 con relación al contenido proteico mientras que para fibra se obtuvo un P valor de 0.000
Generating fuzzy rules by learning from olive tree transpiration measurement - An algorithm to automatize Granier sap flow data analysis
The present study aims at developing an intelligent system of automating data analysis and prediction
embedded in a fuzzy logic algorithm (FAUSY) to capture the relationship between environmental variables
and sap flow measurements (Granier method). Environmental thermal gradients often interfere
with Granier sap flow measurements since this method uses heat as a tracer, thus introducing a bias in
transpiration flux calculation. The FAUSY algorithm is applied to solve measurement problems and provides
an approximate and yet effective way of finding the relationship between the environmental variables
and the natural temperature gradient (NTG), which is too complex or too ill-defined for precise
mathematical analysis. In the process, FAUSY extracts the relationships from a set of input–output environmental
observations, thus general directions for algorithm-based machine learning in fuzzy systems
are outlined. Through an iterative procedure, the algorithm plays with the learning or forecasting via a
simulated model. After a series of error control iterations, the outcome of the algorithm may become
highly refined and be able to evolve into a more formal structure of rules, facilitating the automation
of Granier sap flow data analysis. The system presented herein simulates the occurrence of NTG with reasonable
accuracy, with an average residual error of 2.53% for sap flux rate, when compared to data processing
performed in the usual way. For practical applications, this is an acceptable margin of error given
that FAUSY could correct NTG errors up to an average of 76% of the normal manual correction process. In
this sense, FAUSY provides a powerful and flexible way of establishing the relationships between the
environment and NTG occurrencesinfo:eu-repo/semantics/publishedVersio
RICORS2040 : The need for collaborative research in chronic kidney disease
Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true
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