6,737 research outputs found
Activating the 4th Neutrino of the 3+1 Scheme
Non-Standard Interactions (NSI) of neutrinos with matter has received renewed
interest in recent years. In particular, it has been shown that NSI can
reconcile the solution with IceCube atmospheric data with
GeV, provided that the effective coupling of NSI is large, e.g. .
The main goal of the present paper is to show that contrary to intuition, it is
possible to build viable models with large NSI by invoking a new gauge
symmetry with gauge boson of mass eV. We refer to these new
constructions as models. In the framework of a solution to
LSND and MiniBooNE anomalies, we show that this novel NSI can help to solve the
tension with cosmological bounds and constraints from IceCube atmospheric data
with GeV. We then discuss the implications of the MINOS and MINOS+
results for the 3+1+ scenario.Comment: 24 pages, 5 figure
Inflation meets neutrinos
Constraints on inflationary models typically assume only the standard models
of cosmology and particle physics. By extending the neutrino sector to include
a new interaction with a light scalar mediator (MeV), it is
possible to relax these constraints, in particular via opening up regions of
the parameter space of the spectral index . These new interactions can be
probed at IceCube via interactions of astrophysical neutrinos with the Cosmic
Neutrino Background for nearly all of the relevant parameter space.Comment: 9 pages, 4 figures, comments welcom
Thermodynamically Stable One-Component Metallic Quasicrystals
Classical density-functional theory is employed to study finite-temperature
trends in the relative stabilities of one-component quasicrystals interacting
via effective metallic pair potentials derived from pseudopotential theory.
Comparing the free energies of several periodic crystals and rational
approximant models of quasicrystals over a range of pseudopotential parameters,
thermodynamically stable quasicrystals are predicted for parameters approaching
the limits of mechanical stability of the crystalline structures. The results
support and significantly extend conclusions of previous ground-state
lattice-sum studies.Comment: REVTeX, 13 pages + 2 figures, to appear, Europhys. Let
On the representation theory of finite J-trivial monoids
In 1979, Norton showed that the representation theory of the 0-Hecke algebra
admits a rich combinatorial description. Her constructions rely heavily on some
triangularity property of the product, but do not use explicitly that the
0-Hecke algebra is a monoid algebra.
The thesis of this paper is that considering the general setting of monoids
admitting such a triangularity, namely J-trivial monoids, sheds further light
on the topic. This is a step to use representation theory to automatically
extract combinatorial structures from (monoid) algebras, often in the form of
posets and lattices, both from a theoretical and computational point of view,
and with an implementation in Sage.
Motivated by ongoing work on related monoids associated to Coxeter systems,
and building on well-known results in the semi-group community (such as the
description of the simple modules or the radical), we describe how most of the
data associated to the representation theory (Cartan matrix, quiver) of the
algebra of any J-trivial monoid M can be expressed combinatorially by counting
appropriate elements in M itself. As a consequence, this data does not depend
on the ground field and can be calculated in O(n^2), if not O(nm), where n=|M|
and m is the number of generators. Along the way, we construct a triangular
decomposition of the identity into orthogonal idempotents, using the usual
M\"obius inversion formula in the semi-simple quotient (a lattice), followed by
an algorithmic lifting step.
Applying our results to the 0-Hecke algebra (in all finite types), we recover
previously known results and additionally provide an explicit labeling of the
edges of the quiver. We further explore special classes of J-trivial monoids,
and in particular monoids of order preserving regressive functions on a poset,
generalizing known results on the monoids of nondecreasing parking functions.Comment: 41 pages; 4 figures; added Section 3.7.4 in version 2; incorporated
comments by referee in version
Neuroimaging evidence implicating cerebellum in support of sensory/cognitive processes associated with thirst.
Recent studies implicate the cerebellum, long considered strictly a motor control structure, in cognitive, sensory, and affective phenomenon. The cerebellum, a phylogenetically ancient structure, has reciprocal ancient connections to the hypothalamus, a structure important in vegetative functions. The present study investigated whether the cerebellum was involved in vegetative functions and the primal emotions engendered by them. Using positron emission tomography, we examined the effects on the cerebellum of the rise of plasma sodium concentration and the emergence of thirst in 10 healthy adults. The correlation of regional cerebral blood flow with subjects' ratings of thirst showed major activation in the vermal central lobule. During the development of thirst, the anterior and posterior quadrangular lobule, lingula, and the vermis were activated. At maximum thirst and then during irrigation of the mouth with water to alleviate dryness, the cerebellum was less activated. However, 3 min after drinking to satiation, the anterior quadrangular lobule and posterior cerebellum were highly activated. The increased cerebellar activity was not related to motor behavior as this did not occur. Instead, responses in ancient cerebellar regions (vermis, fastigal nucleus, archicerebellum) may be more directly related to vegetative and affective aspects of thirst experiences, whereas activity in neocerebellar (posterior) regions may be related to sensory and cognitive aspects. Moreover, the cerebellum is apparently not involved in the computation of thirst per se but rather is activated during changes in thirst/satiation state when the brain is "vigilant" and is monitoring its sensory systems. Some neocerebellar activity may also reflect an intentionality for gratification by drinking inherent in the consciousness of thirst
Desarollo de las máquinas de texturación.
Descripción y caracterÃsticas de las máquinas de texturación presentadas en la Feria de la Maquinaria Textil.Peer Reviewe
A laminar flow model of aerosol survival of epidemic and non-epidemic strains of Pseudomonas aeruginosa isolated from people with cystic fibrosis
Cystic fibrosis (CF) is an inherited multi-system disorder characterised by chronic airway infection with pathogens such as Pseudomonas aeruginosa.
Acquisition of P. aeruginosa by patients with CF is usually from the environment, but recent studies have demonstrated patient to patient transmission of certain epidemic strains, possibly via an airborne route. This study was designed to examine the survival of P. aeruginosa within artificially generated aerosols.
Survival was effected by the solution used for aerosol generation. Within the aerosols it was adversely affected by an increase in air temperature. Both epidemic and non-epidemic strains of P. aeruginosa were able to survive within the aerosols, but strains expressing a mucoid phenotype had a survival advantage.
This would suggest that segregating individuals free of P. aeruginosa from those with chronic P. aeruginosa infection who are more likely to be infected with mucoid strains may help reduce the risk of cross-infection. Environmental factors also appear to influence bacterial survival. Warming and drying the air within clinical areas and avoidance of humidification devices may also be beneficial in reducing the risk of cross-infection
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