371 research outputs found
Relational lattices via duality
The natural join and the inner union combine in different ways tables of a
relational database. Tropashko [18] observed that these two operations are the
meet and join in a class of lattices-called the relational lattices- and
proposed lattice theory as an alternative algebraic approach to databases.
Aiming at query optimization, Litak et al. [12] initiated the study of the
equational theory of these lattices. We carry on with this project, making use
of the duality theory developed in [16]. The contributions of this paper are as
follows. Let A be a set of column's names and D be a set of cell values; we
characterize the dual space of the relational lattice R(D, A) by means of a
generalized ultrametric space, whose elements are the functions from A to D,
with the P (A)-valued distance being the Hamming one but lifted to subsets of
A. We use the dual space to present an equational axiomatization of these
lattices that reflects the combinatorial properties of these generalized
ultrametric spaces: symmetry and pairwise completeness. Finally, we argue that
these equations correspond to combinatorial properties of the dual spaces of
lattices, in a technical sense analogous of correspondence theory in modal
logic. In particular, this leads to an exact characterization of the finite
lattices satisfying these equations.Comment: Coalgebraic Methods in Computer Science 2016, Apr 2016, Eindhoven,
Netherland
Statistical Test of Anarchy
"Anarchy" is the hypothesis that there is no fundamental distinction among
the three flavors of neutrinos. It describes the mixing angles as random
variables, drawn from well defined probability distributions dictated by the
group Haar measure. We perform a Kolmogorov-Smirnov (KS) statistical test to
verify whether anarchy is consistent with all neutrino data, including the new
result presented by KamLAND. We find a KS probability for Nature's choice of
mixing angles equal to 64%, quite consistent with the anarchical hypothesis. In
turn, assuming that anarchy is indeed correct, we compute lower bounds on
|U_{e3}|^2, the remaining unknown "angle" of the leptonic mixing matrix.Comment: 5 pages, 2 figures. Improved criteria for testing the hypothesis and
deriving lower limits on theta_{13
Right-handed Sneutrinos as Nonthermal Dark Matter
When the minimal supersymmetric standard model is augmented by three
right-handed neutrino superfields, one generically predicts that the neutrinos
acquire Majorana masses. We postulate that all supersymmetry (SUSY) breaking
masses as well as the Majorana masses of the right-handed neutrinos are around
the electroweak scale and, motivated by the smallness of neutrino masses,
assume that the lightest supersymmetric particle (LSP) is an almost-pure
right-handed sneutrino. We discuss the conditions under which this LSP is a
successful dark matter candidate. In general, such an LSP has to be nonthermal
in order not to overclose the universe, and we find the conditions under which
this is indeed the case by comparing the Hubble expansion rate with the rates
of the relevant thermalizing processes, including self-annihilation and
co-annihilation with other SUSY and standard model particles.Comment: 17 pages v.2: References adde
Recommended from our members
Making management (more) relevant: breaking down disciplinary walls and pursuing neglected independent variables
The Walls Project encourages educators to broaden management teaching beyond individual and organizational variables and outcomes to systemic variables and outcomes. Its focus is on discovering independent variables that have social and environmental impacts and are currently neglected. Founded by six individuals who met at a RMLE UnConference in 2017,the Project decided to share pedagogical materials, examine them for commonalities, and present their findings at the MOBTC conference in 2019. This article summarizes these materials with an eye to revealing several variables of consequence, such as socioeconomic status and belief in economic growth, which are studied and taught infrequently in business schools. We suggest that researchers examine business curricula for similar neglected variables, study their impact across systems levels, and then develop them pedagogically to enhance management education that has a social and environmental impact
Minimalistic Neutrino Mass Model
We consider the simplest model which solves the solar and atmospheric
neutrino puzzles, in the sense that it contains the smallest amount of beyond
the Standard Model ingredients. The solar neutrino data is accounted for by
Planck-mass effects while the atmospheric neutrino anomaly is due to the
existence of a single right-handed neutrino at an intermediate mass scale
between 10^9 GeV and 10^14 GeV. Even though the neutrino mixing angles are not
exactly predicted, they can be naturally large, which agrees well with the
current experimental situation. Furthermore, the amount of lepton asymmetry
produced in the early universe by the decay of the right-handed neutrino is
very predictive and may be enough to explain the current baryon-to-photon ratio
if the right-handed neutrinos are produced out of thermal equilibrium. One
definitive test for the model is the search for anomalous seasonal effects at
Borexino.Comment: 19 pages, 3 figures, references added, results unchange
Early start of enzyme replacement therapy in pediatric male patients with classical Fabry disease is associated with attenuated disease progression
Background
Enzyme replacement therapy (ERT) slows disease progression of Fabry disease (FD), especially when initiated before the onset of irreversible organ damage. However, with the clinically asymptomatic progression of renal, cardiac and cerebral disease manifestations spanning decades, optimal timing of ERT initiation remains unclear.
Methods
In this cross-sectional retrospective study, seven male FD patients with a classical disease phenotype (cFD) who started treatment with agalsidase-beta in childhood were evaluated after 10 years of treatment (median age at evaluation 24 years, range 14â26). Cardiac imaging (echocardiography and MRI), electrophysiological and biochemical data of these patients were compared to those of untreated male cFD patients (n = 23, median age 22 years, range 13â27).
Results
Albuminuria was less common and less severe in treated patients (albumin to creatinine ratio, ACR 0â8.8 mg/mmol, median 0.4) compared to untreated patients (ACR 0â248 mg/mmol, median 3.7, p = 0.02). The treated group had a lower left ventricular mass, measured using echocardiography (median 80 g/m2 versus 94 g/m2, p = 0.02) and MRI (median 53 g/m2 versus 68 g/m2, p = 0.02). Myocardial fibrosis was absent in all included patients. eGFR was normal in all treated patients whereas 7/23 (30%) of untreated patients had abnormal eGFR. Cerebral manifestations did not differ.
Conclusions
Start of treatment with ERT before age 16, in male cFD patients is associated with reduced occurrence of renal and cardiac manifestations of FD, as assessed by intermediate endpoints. Confirmation that this approach delays or even prevents renal failure and cardiac events requires another decade of follow-up.publishedVersio
A CD3-Specific Antibody Reduces Cytokine Production and Alters Phosphoprotein Profiles in Intestinal Tissues From Patients With Inflammatory Bowel Disease
NOTICE: this is the authorâs version of a work that was accepted for publication in Gastroenterology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in GASTROENTEROLOGY, 10.1053/j.gastro.2014.03.04
Global Symmetries in the Antifield-Formalism
In this paper, two things are done. (i) First, it is shown that any global
symmetry of a gauge-invariant theory can be extended to the ghosts and the
antifields so as to leave invariant the solution of the master-equation (before
gauge fixing). (ii) Second, it is proved that the incorporation of the rigid
symmetries to the solution of the master-equation through the introduction of a
constant ghost for each global symmetry can be obstructed already at the
classical level whenever the theory possesses higher order conservation laws.
Explicit examples are given.Comment: 12 pages, no figures, late
Narcissistic self-sorting of n-acene nano-ribbons yielding energy-transfer and electroluminescence at p-n junctions
The 2,3-didecyloxy derivative of an n-type anthracene (n-BG) and a p-type tetracene (p-R) have been synthesized and their self-assembly into nano-ribbons studied. Hyperspectral fluorescence imaging revealed their narcissistic self-sorting, leading to separated nanoribbons emitting with very different colors (blue or green for n-BG, depending on the growth solvent, and red for p-R). It is unique that the usual origins of self-sorting, such as specific H-bonding, different growth kinetics, or incompatible steric hindrance can be ruled out. Hence, the narcissistic behaviour is herein proposed to originate from a sofar unconsidered cause: the discrepancy between the quadrupolar character of n-BG and dipolar character of p-R. At the p-n junctions of these nanoribbons, inter-ribbon FRET and electro-luminescence switch-on were observed by fluorescence/luminescence microscopy.The authors acknowledge the financial support of the European Research Council Marie Curie Actions (FP7-PEOPLE-2012-ITN SMARTNET Grant agreement Nr 316656); the CNRS; the French Ministry of Education and Research; the Region Aquitaine; the ANR-06-JCJC-0030; the Department of Education, Science and Universities of the Basque Country Government (postdoctoral grant and project IT1639-22); the "Arina" informatic cluster of UPV/EHU; the facilities ELORGA of UB; and the ANR-17-CE24-0033-01 RESOLVE. The authors thank Dr A. Mendez-Ardoy for the CV measurements and CESAMO for structural analyses (ISM, Univ. Bordeaux)
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