119 research outputs found
Analysis of Scalar Field Cosmology with Phase Space Deformations
Phase space deformations on scalar field cosmology are studied. The deformation is introduced by
modifying the symplectic structure of the minisuperspace variables. The effects of the deformation are studied in the “C-frame” and the “NC-frame.” In order to remove the ambiguities of working on different frames, a new principle is introduced. When we impose that both frames should be physically equivalent, we conclude that the only possibility for this model, is to have an effective cosmological constant Λeff≥0. Finally we bound the parameter space for θ and β
WKB-type Approximation to Noncommutative Quantum Cosmology
In this work, we develop and apply the WKB approximation to several examples
of noncommutative quantum cosmology, obtaining the time evolution of the
noncommutative universe, this is done starting from a noncommutative quantum
formulation of cosmology where the noncommutativity is introduced by a
deformation on the minisuperspace variables. This procedure gives a
straightforward algorithm to incorporate noncommutativity to cosmology and
inflation.Comment: Revtex4, 6 pages, no figure
Phase Transition in Liquid Drop Fragmentation
A liquid droplet is fragmented by a sudden pressurized-gas blow, and the
resulting droplets, adhered to the window of a flatbed scanner, are counted and
sized by computerized means. The use of a scanner plus image recognition
software enables us to automatically count and size up to tens of thousands of
tiny droplets with a smallest detectable volume of approximately 0.02 nl. Upon
varying the gas pressure, a critical value is found where the size-distribution
becomes a pure power-law, a fact that is indicative of a phase transition. Away
from this transition, the resulting size distributions are well described by
Fisher's model at coexistence. It is found that the sign of the surface
correction term changes sign, and the apparent power-law exponent tau has a
steep minimum, at criticality, as previously reported in Nuclear
Multifragmentation studies [1,2]. We argue that the observed transition is not
percolative, and introduce the concept of dominance in order to characterize
it. The dominance probability is found to go to zero sharply at the transition.
Simple arguments suggest that the correlation length exponent is nu=1/2. The
sizes of the largest and average fragments, on the other hand, do not go to
zero but behave in a way that appears to be consistent with recent predictions
of Ashurst and Holian [3,4].Comment: 10 pages, 11 figures. LaTeX (revtex4) with psfig/epsfi
Proteomic profiling reveals mitochondrial dysfunction in the cerebellum of transgenic mice overexpressing DYRK1A, a Down syndrome candidate gene
DYRK1A is a dual-specificity kinase that is overexpressed in Down syndrome (DS) and plays a key role in neurogenesis, neuronal differentiation and function, cognitive phenotypes, and aging. Dyrk1A has also been implicated in cerebellar abnormalities observed in association with DS, and normalization of Dyrk1A dosage rescues granular and Purkinje cell densities in a trisomic DS mouse model. However, the underlying molecular mechanisms governing these processes are unknown.To shed light on the effects of Dyrk1A overexpression in the cerebellum, here we investigated the cerebellar proteome in transgenic Dyrk1A overexpressing mice in basal conditions and after treatment with green tea extract containing epigallocatechin-3-gallate (EGCG), a DYRK1A inhibitor.Our results showed that Dyrk1A overexpression alters oxidative phosphorylation and mitochondrial function in the cerebellum of transgenic mice. These alterations are significantly rescued upon EGCG-containing green tea extract treatment, suggesting that its effects in DS could depend in part on targeting mitochondria, as shown by the partially restoration by the treatment of the increased mtDNA copy number in TG non-treated mice.Copyright © 2022 De Toma, Ortega, Fernández-Blanco, Calderón, Barahona, Trullàs, Sabidó and Dierssen
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Revisiting past experiences of LGBTQ+-identifying students: an analysis framed by the UN’s Sustainable Development Goals
The United Nations (UN) places inclusive and equitable lifelong quality education at the center of its Sustainable Development Goal (SDG) 4: Quality Education. Nevertheless, the express inclusion of gender non-conforming and sexual minority students is omitted from UN communications. Drawing on interview and focus group data with recent secondary graduates who identify as LGBTQ+ (n = 20), we investigate their experiences, in terms of equity and inclusivity and lack thereof, in schools during the first years of the SDG-era in Spain (the data collection type respected participants’ personal preferences). Three SDGs, complementary to SDG4, were used as a framework for data analysis: SDG3 Good Health and Well-being, SDG5 Gender Equality, and SDG10 Reduced Inequalities, with SDG4 interconnectedly at the center of the overarching analyses. Participants reported preventable aggressions that affected their mental health and wellbeing in schools, receiving little LGBTQ+-related content in classes other than one-off mentions, and reflected on gender inequalities in their treatment from both peers and teachers. The authors discuss the need for local and national development education action plans and policies to address the exclusion and marginalization of LGBTQ+ students in Spanish high schools and elsewhere
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