2,198 research outputs found
The similarity metric
A new class of distances appropriate for measuring similarity relations
between sequences, say one type of similarity per distance, is studied. We
propose a new ``normalized information distance'', based on the noncomputable
notion of Kolmogorov complexity, and show that it is in this class and it
minorizes every computable distance in the class (that is, it is universal in
that it discovers all computable similarities). We demonstrate that it is a
metric and call it the {\em similarity metric}. This theory forms the
foundation for a new practical tool. To evidence generality and robustness we
give two distinctive applications in widely divergent areas using standard
compression programs like gzip and GenCompress. First, we compare whole
mitochondrial genomes and infer their evolutionary history. This results in a
first completely automatic computed whole mitochondrial phylogeny tree.
Secondly, we fully automatically compute the language tree of 52 different
languages.Comment: 13 pages, LaTex, 5 figures, Part of this work appeared in Proc. 14th
ACM-SIAM Symp. Discrete Algorithms, 2003. This is the final, corrected,
version to appear in IEEE Trans Inform. T
Kalirin, a Key Player in Synapse Formation, Is Implicated in Human Diseases
Synapse formation is considered to be crucial for learning and memory. Understanding the underlying molecular mechanisms of synapse formation is a key to understanding learning and memory. Kalirin-7, a major isoform of Kalirin in adult rodent brain, is an essential component of mature excitatory synapses. Kalirin-7 interacts with multiple PDZ-domain-containing proteins including PSD95, spinophilin, and GluR1 through its PDZ-binding motif. In cultured hippocampal/cortical neurons, overexpression of Kalirin-7 increases spine density and spine size whereas reduction of endogenous Kalirin-7 expression decreases synapse number, and spine density. In Kalirin-7 knockout mice, spine length, synapse number, and postsynaptic density (PSD) size are decreased in hippocampal CA1 pyramidal neurons; these morphological alterations are accompanied by a deficiency in long-term potentiation (LTP) and a decreased spontaneous excitatory postsynaptic current (sEPSC) frequency. Human Kalirin-7, also known as Duo or Huntingtin-associated protein-interacting protein (HAPIP), is equivalent to rat Kalirin-7. Recent studies show that Kalirin is relevant to many human diseases such as Huntington's Disease, Alzheimer's Disease, ischemic stroke, schizophrenia, depression, and cocaine addiction. This paper summarizes our recent understanding of Kalirin function
Combining isotonic regression and EM algorithm to predict genetic risk under monotonicity constraint
In certain genetic studies, clinicians and genetic counselors are interested
in estimating the cumulative risk of a disease for individuals with and without
a rare deleterious mutation. Estimating the cumulative risk is difficult,
however, when the estimates are based on family history data. Often, the
genetic mutation status in many family members is unknown; instead, only
estimated probabilities of a patient having a certain mutation status are
available. Also, ages of disease-onset are subject to right censoring. Existing
methods to estimate the cumulative risk using such family-based data only
provide estimation at individual time points, and are not guaranteed to be
monotonic or nonnegative. In this paper, we develop a novel method that
combines Expectation-Maximization and isotonic regression to estimate the
cumulative risk across the entire support. Our estimator is monotonic,
satisfies self-consistent estimating equations and has high power in detecting
differences between the cumulative risks of different populations. Application
of our estimator to a Parkinson's disease (PD) study provides the age-at-onset
distribution of PD in PARK2 mutation carriers and noncarriers, and reveals a
significant difference between the distribution in compound heterozygous
carriers compared to noncarriers, but not between heterozygous carriers and
noncarriers.Comment: Published in at http://dx.doi.org/10.1214/14-AOAS730 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
1-[2-(3,5-Difluorobenzyloxy)phenyl]ethanone
In the title compound, C15H12F2O2, the dihedral angle between the aromatic rings is 70.43 (4)°. The crystal packing exhibits no significantly short intermolecular contacts
Totally thoracoscopic closure of ventricular septal defect without a robotically assisted surgical system: A summary of 119 cases
ObjectivesTo summarize the clinical outcomes of totally thoracoscopic closure of a ventricular septal defect (VSD).MethodsTotally thoracoscopic VSD closure was performed in 119 patients (66 boys; mean age, 7.1 ± 3.6 years). An additional 35 patients undergoing open-chest VSD closure were selected as a control group. Using 3 port incisions in the right chest, pericardiotomy, bicaval occlusion, atriotomy, and VSD closure were performed by thoracoscopy without the aid of a robotically assisted surgical system.ResultsCardiopulmonary bypass and aortic crossclamp times were 42.2 ± 9.8 and 32.5 ± 7.3 minutes, respectively. There were no deaths but 1 patient required insertion of a permanent pacemaker as a result of postoperative atrioventricular conduction block. The length of stay in the intensive care unit (11.0 ± 2.6 vs 22.9 ± 4.9 hours, P < .01) or postoperative hospital stay (4.2 ± 1.1 vs 6.6 ± 2.1 days, P < .03) in the thoracoscopic group were shorter than in the control group. The percentage of patients who required postoperative opioid analgesics in the thoracoscopic group was lower than in the control group (31.9% vs 74.2%, P < .001). Rate of blood transfusion during the operation (17.6% vs 65.7%, P = .001) and the postoperative use of opioid analgesics (31.9% vs 74.3%, P = .003) in the thoracoscopic group was lower than in the control group. Transesophageal echocardiographic analysis 4.6 ± 2.3 months after the operation showed complete closure of the defect.ConclusionsTotally thoracoscopic closure of VSD through a 3-port entry was safe and effective
Adaptive Control of Resource Flow to Optimize Construction Work and Cash Flow via Online Deep Reinforcement Learning
Due to complexity and dynamics of construction work, resource, and cash
flows, poor management of them usually leads to time and cost overruns,
bankruptcy, even project failure. Existing approaches in construction failed to
achieve optimal control of resource flow in a dynamic environment with
uncertainty. Therefore, this paper introducess a model and method to adaptive
control the resource flows to optimize the work and cash flows of construction
projects. First, a mathematical model based on a partially observable Markov
decision process is established to formulate the complex interactions of
construction work, resource, and cash flows as well as uncertainty and
variability of diverse influence factors. Meanwhile, to efficiently find the
optimal solutions, a deep reinforcement learning (DRL) based method is
introduced to realize the continuous adaptive optimal control of labor and
material flows, thereby optimizing the work and cash flows. To assist the
training process of DRL, a simulator based on discrete event simulation is also
developed to mimic the dynamic features and external environments of a project.
Experiments in simulated scenarios illustrate that our method outperforms the
vanilla empirical method and genetic algorithm, possesses remarkable capability
in diverse projects and external environments, and a hybrid agent of DRL and
empirical method leads to the best result. This paper contributes to adaptive
control and optimization of coupled work, resource, and cash flows, and may
serve as a step stone for adopting DRL technology in construction project
management
In-gap states with nearly free electron characteristics in layered structure trivalent iridates
Iridium oxides (iridates) provide good platform to study the complex
interplay of spin-orbit coupling (SOC) interactions, correlation effects, Hund
coupling and lattice degree of freedom. However, previous studies primarily
focus on tetravalent (Ir4+, 5d5) and pentavalent (Ir5+, 5d4) iridates. Here, we
turn our attention to a recently reported unprecedented trivalent (Ir3+, 5d6)
iridates, K0.75Na0.25IrO2, crystalizes in a triangular lattice with
edge-sharing IrO6 octahedra and alkali ions intercalated [IrO2]- layers. We
theoretically determine the preferred occupied positions of the alkali ions
from energetic viewpoints, and reproduce the experimentally observed
semiconducting behavior and nonmagnetic (NM) properties. The SOC interactions
play a critical role in the band dispersion, resulting in NM Jeff = 0 states.
More intriguingly, our electronic structure not only confirms the experimental
speculation of the presence of in-gap states and explains the abnormal low
activation energy in K0.75Na0.25IrO2, but also puts forward the in-gap states
featured with nearly free electron characteristics. Our theoretical results
provide new insights into the unconventional electronic structures of the
trivalent iridates and imply its promising applications in nanoelectronic
devices such as ideal electron transport channels.Comment: 14+15pages,6+6figure
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