3,103 research outputs found
A stochastic approach to the closure of accessible sets of control systems with application on homogeneous spaces
Given a control system on a compact manifold M, we study conditions for the foliation defined by the accessible sets to be dense in M. For this, we relate the control system to a stochastic differential equation and, by the support theorem, we give a characterization of the density in terms of the infinitesimal generator of the diffusion and its invariant measures.33351953
Genome sequence of Rhizobium sullae HCNT1 isolated from Hedysarum coronarium nodules and featuring peculiar denitrification phenotypes
The genome sequence of Rhizobium sullae strain HCNT1, isolated from root nodules of the legume Hedysarum coronarium growing in wild stands in Tuscany, Italy, is described here. Unlike other R. sullae strains, this isolate features a truncated denitrification pathway lacking NO/N2O reductase activity and displaying high sensitivity to nitrite under anaerobic conditions
Evaluación de la cronología dentaria en grupos wichi, toba y criollos del Gran Chaco (provincia de Formosa)
Se realizó el análisis de la cronología de erupción dentaria como una evaluación de maduración funcional en individuos pertenecientes a comunidades wichí, toba y crillas del Gran Chaco (provincia de Formosa, Argentina). Se tuvieron en cuenta los elementos dentarios presentes en cada hemiarcada izquierda y el orden de erupción. El objetivo del presente trabajo fue examinar el comportamiento de estas variables en la población infantil de ambos sexos de las distintas comunidades. La muestra estuvo integrada por 159 individuos entre 6 y 12 años. La metodología aplicada fue la del conteo de las piezas dentarias individuales. Los datos fueron volcados en una ficha odontológica pertinente. Se analizó comparativamente el orden de erupción en cada muestra investigada. Resultados: a) diferencias de erupción entre los wichí, toba y criollos; b) alteración en el orden de erupción, en el segundo premolar y los segundos molares y c) variación de erupción de las niñas con respecto a los varones. Concluimos que los grupos pertenecientes a la misma zona geográfica, pero con distinto nivel socioeconómico, muestran diferencias en la cronología dentaria, lo cual estaría indicando una influencia ambiental sobre el determinante genético
PREVALÊNCIA DE SOBREPESO E OBESIDADE EM PRÉ-ESCOLARES DE ALTO NÍVEL SÓCIOECONÔMICO DA CIDADE DE ARACAJU-SE
Model of Study: Prevalence Study. Objective: The objective of the present study was to esteem the prevalence of overweight and obesity among preschool children of high level economical partner of Aracaju-Sergipe city, Brazil, measured in a direct way. Methods: 243 children, being 51% of the female sex from 3,5 to 5,5 years old of high level economical partner, in agreement to National Association of Company of Research was appraised with relationship to the weight and the stature, to calculate IMC and to classify them in normal, overweight or obesity in agreement with the criteria of it Cole et al. Results: The prevalence of overweight was 16% and the obesity of 7,9%, and there were not significant differences in the prevalence of overweight and obesity between boys and girls (p > 0,05), as well as there were not differences among the groups of age for each sex (p > 0,05). Conclusion: The overweight and the obesity were made presents in a sample of children from 3,5 to 5,5 years of age of high purchasing power of the Aracaju city. Modelo de Estudo: Estudo de Prevalência. O objetivo do presente estudo foi estimar a prevalência de sobrepeso e obesidade em pré-escolares de alto nível socioeconô-mico da cidade de Aracaju-Sergipe, Brasil, medido de forma direta. Métodos: 243 crianças, sendo 51% do sexo feminino de 3,5 a 5,5 anos de idade de alto nível socioeconômico, segundo critérios da Associação Nacional de Empresa de Pesquisa, foram avaliadas quanto ao peso e a estatura, para se calcular o IMC e classificá-las em normal, sobrepeso ou obesidade de acordo com os critérios de Cole et al. Resultados: Na amostra estudada a prevalência de sobrepeso foi de 16% e a obesidade de 7,9%, sendo que não houve diferenças significativas na prevalência de sobrepeso e obesidade entre meninos e meninas (p > 0,05). Não houve também diferenças entre os grupos de idade para cada sexo (p > 0,05). Conclusão: O sobrepeso e a obesidade se fizeram presentes em uma amostra de crianças de 3,5 a 5,5 anos de idade de alto poder aquisitivo da cidade de Aracaju-SE.
Unveiling the Dynamics of the Universe
We explore the dynamics and evolution of the Universe at early and late
times, focusing on both dark energy and extended gravity models and their
astrophysical and cosmological consequences. Modified theories of gravity not
only provide an alternative explanation for the recent expansion history of the
universe, but they also offer a paradigm fundamentally distinct from the
simplest dark energy models of cosmic acceleration. In this review, we perform
a detailed theoretical and phenomenological analysis of different modified
gravity models and investigate their consistency. We also consider the
cosmological implications of well motivated physical models of the early
universe with a particular emphasis on inflation and topological defects.
Astrophysical and cosmological tests over a wide range of scales, from the
solar system to the observable horizon, severely restrict the allowed models of
the Universe. Here, we review several observational probes -- including
gravitational lensing, galaxy clusters, cosmic microwave background temperature
and polarization, supernova and baryon acoustic oscillations measurements --
and their relevance in constraining our cosmological description of the
Universe.Comment: 94 pages, 14 figures. Review paper accepted for publication in a
Special Issue of Symmetry. "Symmetry: Feature Papers 2016". V2: Matches
published version, now 79 pages (new format
Reciprocity, Fairness and the Financial Burden of Undertaking COVID-19 Hotel Quarantine in Australia
In late March 2020 in response to the COVID-19 pandemic, Australia introduced mandatory 14-day supervised quarantine at hotels and other designated facilities for all international arrivals. From July 2020, most states and territories introduced a fixed charge for quarantine of up to $3220 per adult. The introduction of the fee was rationalised on the basis that Australians had been allowed sufficient time to return and there was a need to recover some of the cost associated with administering the program. Drawing on an empirical study of 58 returned Australian citizens and residents quarantined between March 2020 and January 2021, this paper aims to explore how people experienced paying for hotel quarantine, particularly with respect to fairness and relatedly, the principle of reciprocity. Reciprocity requires that the state has an obligation to assist individuals in discharging their duty to comply with public health measures and avoid disproportionate burdens accruing to populations or individuals. Though participants had varying opinions on whether they thought it fair to be charged for their quarantine, for many, the fee constituted a significant burden and source of stress. Given the undertaking of quarantine is primarily for the benefit of the public good, we argue the financial cost imposed on individuals does not meet the demands of reciprocity. It is imperative that future quarantine and isolation arrangements consider seriously the need to minimise burdens of individuals subject to such measures, and that fees do not become a new norm in public health and infectious disease control
Same-Sign Taus Signatures of Maximally Flavor-Violating Scalars at the LHC
We explore single and double flavor-violating scalars (flavons) production at
the 13 and 14 TeV LHC in an effective field theory formulation where flavons
always change the flavor of Standard Model fermions. When those scalars couple
to mass, their flavor-changing couplings to top quarks and tau leptons are
favored. Focusing on the mass region below the top quark mass, we find
couplings that fit the muon and electron discrepancies and avoid
several current experimental constraints. We determine the potential of the LHC
to exclude or discover such a new physics scenario with clean signatures
consisting of same-sign tau leptons and the simultaneous observation of
resonances in the tau plus electron or muon invariant mass. We found that in
the double production mode, effective couplings down to order
TeV can be probed for flavon masses in the 10-170 GeV range at the
HL-LHC at 14 TeV, but couplings down to 0.1 TeV can be excluded at 95\%
confidence level with data collected by the 13 TeV LHC in the same mass
interval.Comment: 32 pages, 12 figures, 2 table
Photon rings as tests for alternative spherically symmetric geometries with thin accretion disks
The imaging by the Event Horizon Telescope (EHT) of the supermassive central
objects at the heart of the M87 and Milky Way (Sgr A) galaxies, has
marked the first step into peering at the shadow and photon rings that
characterize the optical appearance of black holes surrounded by an accretion
disk. Recently, Vagnozzi et. al. [S.~Vagnozzi, \textit{et al.} arXiv:2205.07787
[gr-qc]] used the claim by the EHT that the size of the shadow of Sgr A
can be inferred by calibrated measurements of the bright ring enclosing it, to
constrain a large number of spherically symmetric space-time geometries. In
this work we use this result to study some features of the first and second
photon rings of a restricted pool of such geometries in thin accretion disk
settings. The emission profile of the latter is described by calling upon three
analytic samples belonging to the family introduced by Gralla, Lupsasca and
Marrone, in order to characterize such photon rings using the Lyapunov exponent
of nearly bound orbits and discuss its correlation with the luminosity
extinction rate between the first and second photon rings. We finally elaborate
on the chances of using such photon rings as observational discriminators of
alternative black hole geometries using very long baseline interferometry.Comment: 17 pages, 58 figures/image
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