18 research outputs found
Percolation for the stable marriage of Poisson and Lebesgue with random appetites
Let be a set of centers chosen according to a Poisson point process in
. Consider the allocation of to which is
stable in the sense of the Gale-Shapley marriage problem, with the additional
feature that every center has a random appetite , where
is a nonnegative scale constant and is a nonnegative random
variable. Generalizing previous results by Freire, Popov and Vachkovskaia
(\cite{FPV}), we show the absence of percolation when is small enough,
depending on certain characteristics of the moment of .Comment: 12 pages. Final versio
Assessing, testing and estimating the amount of fine-tuning by means of active information
A general framework is introduced to estimate how much external information
has been infused into a search algorithm, the so-called active information.
This is rephrased as a test of fine-tuning, where tuning corresponds to the
amount of pre-specified knowledge that the algorithm makes use of in order to
reach a certain target. A function quantifies specificity for each possible
outcome of a search, so that the target of the algorithm is a set of highly
specified states, whereas fine-tuning occurs if it is much more likely for the
algorithm to reach the target than by chance. The distribution of a random
outcome of the algorithm involves a parameter that quantifies how
much background information that has been infused. A simple choice of this
parameter is to use in order to exponentially tilt the distribution
of the outcome of the search algorithm under the null distribution of no
tuning, so that an exponential family of distributions is obtained. Such
algorithms are obtained by iterating a Metropolis-Hastings type of Markov
chain, and this makes it possible to compute the their active information under
equilibrium and non-equilibrium of the Markov chain, with or without stopping
when the targeted set of fine-tuned states has been reached. Other choices of
tuning parameters are discussed as well. Nonparametric and parametric
estimators of active information and tests of fine-tuning are developed when
repeated and independent outcomes of the algorithm are available. The theory is
illustrated with examples from cosmology, student learning, reinforcement
learning, a Moran type model of population genetics, and evolutionary
programming.Comment: 28 pages, 3 figure
Forecast Ergodicity: Prediction Modeling Using Algorithmic Information Theory
The capabilities of machine intelligence are bounded by the potential of data
from the past to forecast the future. Deep learning tools are used to find
structures in the available data to make predictions about the future. Such
structures have to be present in the available data in the first place and they
have to be applicable in the future. Forecast ergodicity is a measure of the
ability to forecast future events from data in the past. We model this bound by
the algorithmic complexity of the available data
FamĂlies botĂ niques de plantes medicinals
Facultat de Farmà cia, Universitat de Barcelona. Ensenyament: Grau de Farmà cia, Assignatura: Botà nica FarmacÚutica, Curs: 2013-2014, Coordinadors: Joan Simon, CÚsar Blanché i
Maria Bosch.Els materials que aquĂ es presenten sĂłn els recull de 175 treballs dâuna famĂlia botĂ nica dâinterĂšs medicinal realitzats de manera individual. Els treballs han estat realitzat
per la totalitat dels estudiants dels grups M-2 i M-3 de lâassignatura BotĂ nica FarmacĂšutica
durant els mesos dâabril i maig del curs 2013-14. Tots els treballs sâhan dut a terme a travĂ©s de la plataforma de GoogleDocs i han estat tutoritzats pel professor de lâassignatura i revisats i finalment co-avaluats entre els propis estudiants. Lâobjectiu principal de lâactivitat ha estat fomentar lâaprenentatge autĂČnom i col·laboratiu en BotĂ nica farmacĂšutica
Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)
Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters.
Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs).
Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001).
Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio
not available
Neste trabalho generaliza-se o chamado casamento estĂĄvel de Poisson e Lebesgue para o caso de apetite aleatĂłrio.Estudam-se propriedades inerentes ao modelo como a existĂȘncia e a unicidade quase certa das alocaçÔes quando as funçÔes de alocação vĂŁo num processo pontual ergĂłdico, entre outras. Estudam-se tambĂ©m propriedades de percolação sobre a existĂȘncia da fase sub-crĂtica e obtĂȘm-se limites superiores polinomiais nas fases super-crĂtica e sub-crĂtica do modelo.not availabl
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A Note on Large Deviations for the Stable Marriage of Poisson and Lebesgue with Random Appetites
Let
Î
ââ
d
be a set of centers chosen according to a Poisson point process in â
d
. Let
Ï
be an allocation of â
d
to
Î
in the sense of the GaleâShapley marriage problem, with the additional feature that every center
Ο
â
Î
has an appetite given by a nonnegative random variable
α
. Generalizing some previous results, we study large deviations for the distance of a typical point
x
ââ
d
to its center
Ï
(
x
)â
Î
, subject to some restrictions on the moments ofÂ
α