1,414 research outputs found
Heavy Quark Fluorescence
Heavy hadrons containing heavy quarks (for example, Upsilon-mesons) feature a
scale separation between the heavy quark mass (about 4.5 GeV for the b-quark)
and the QCD scale (about 0.3 GeV}) that controls effective masses of lighter
constituents. Therefore, as in ordinary molecules, the de-excitation of the
lighter, faster degrees of freedom leaves the velocity distribution of the
heavy quarks unchanged, populating the available decay channels in
qualitatively predictable ways. Automatically an application of the
Franck-Condon principle of molecular physics explains several puzzling results
of Upsilon(5S) decays as measured by the Belle collaboration, such as the high
rate of Bs*-anti Bs* versus Bs*-anti Bs production, the strength of three-body
B-anti B + pion decays, or the dip in B momentum shown in these decays. We
argue that the data is showing the first Sturm-Liouville zero of the
Upsilon(5S) quantum mechanical squared wavefunction, and providing evidence for
a largely b-anti b composition of this meson.Comment: 4 pages, 4 figures, Figure 2 updated and some typos corrected. To be
published in Physical Review Letter
Development and Validation of a Method for Profiling Post-Translational Modification Activities Using Protein Microarrays
Background: Post-translational modifications (PTMs) impact on the stability, cellular location, and function of a protein thereby achieving a greater functional diversity of the proteome. To fully appreciate how PTMs modulate signaling networks, proteome-wide studies are necessary. However, the evaluation of PTMs on a proteome-wide scale has proven to be technically difficult. To facilitate these analyses we have developed a protein microarray-based assay that is capable of profiling PTM activities in complex biological mixtures such as whole-cell extracts and pathological specimens.Methodology/Principal Findings: In our assay, protein microarrays serve as a substrate platform for in vitro enzymatic reactions in which a recombinant ligase, or extracts prepared from whole cells or a pathological specimen is overlaid. The reactions include labeled modifiers (e. g., ubiquitin, SUMO1, or NEDD8), ATP regenerating system, and other required components (depending on the assay) that support the conjugation of the modifier. In this report, we apply this methodology to profile three molecularly complex PTMs (ubiquitylation, SUMOylation, and NEDDylation) using purified ligase enzymes and extracts prepared from cultured cell lines and pathological specimens. We further validate this approach by confirming the in vivo modification of several novel PTM substrates identified by our assay.Conclusions/Significance: This methodology offers several advantages over currently used PTM detection methods including ease of use, rapidity, scale, and sample source diversity. Furthermore, by allowing for the intrinsic enzymatic activities of cell populations or pathological states to be directly compared, this methodology could have widespread applications for the study of PTMs in human diseases and has the potential to be directly applied to most, if not all, basic PTM research
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A phase 1 trial dose-escalation study of tipifarnib on a week-on, week-off schedule in relapsed, refractory or high-risk myeloid leukemia.
Inhibition of farnesyltransferase (FT) activity has been associated with in vitro and in vivo anti-leukemia activity. We report the results of a phase 1 dose-escalation study of tipifarnib, an oral FT inhibitor, in patients with relapsed, refractory or newly diagnosed (if over age 70) acute myelogenous leukemia (AML), on a week-on, week-off schedule. Forty-four patients were enrolled, two patients were newly diagnosed, and the rest were relapsed or refractory to previous treatment, with a median age of 61 (range 33-79). The maximum tolerated dose was determined to be 1200 mg given orally twice daily (b.i.d.) on this schedule. Cycle 1 dose-limiting toxicities were hepatic and renal. There were three complete remissions seen, two at the 1200 mg b.i.d. dose and one at the 1000 mg b.i.d. dose, with minor responses seen at the 1400 mg b.i.d. dose level. Pharmacokinetic studies performed at doses of 1400 mg b.i.d. showed linear behavior with minimal accumulation between days 1-5. Tipifarnib administered on a week-on, week-off schedule shows activity at higher doses, and represents an option for future clinical trials in AML
Periodic magnetorotational dynamo action as a prototype of nonlinear magnetic field generation in shear flows
The nature of dynamo action in shear flows prone to magnetohydrodynamic
instabilities is investigated using the magnetorotational dynamo in Keplerian
shear flow as a prototype problem. Using direct numerical simulations and
Newton's method, we compute an exact time-periodic magnetorotational dynamo
solution to the three-dimensional dissipative incompressible
magnetohydrodynamic equations with rotation and shear. We discuss the physical
mechanism behind the cycle and show that it results from a combination of
linear and nonlinear interactions between a large-scale axisymmetric toroidal
magnetic field and non-axisymmetric perturbations amplified by the
magnetorotational instability. We demonstrate that this large scale dynamo
mechanism is overall intrinsically nonlinear and not reducible to the standard
mean-field dynamo formalism. Our results therefore provide clear evidence for a
generic nonlinear generation mechanism of time-dependent coherent large-scale
magnetic fields in shear flows and call for new theoretical dynamo models.
These findings may offer important clues to understand the transitional and
statistical properties of subcritical magnetorotational turbulence.Comment: 10 pages, 6 figures, accepted for publication in Physical Review
A dynamic emotional model for agent societies
This paper presents a first approximation of a dynamic emotional
model to be employed in agent societies. The proposed model is
based on the PAD emotional model and allows the representation of
the emotional contagion phenomena of a heterogeneous group of agents
which are capable of express emotions. Moreover, the proposal allows
the definition of the social emotion of this group of agents. The model is
mainly based on three elements: personality, empathy and affinity. These
elements allow the characterization of each individual, causing them susceptible
to vary in some degre the emotions of other individuals
Detecting social emotions with a NAO robot
This article aims to give an approach of a dynamic and emotional
propagation, which allows to calculate the propagation of the emotion
of a group of humans and/or intelligent entities. The dynamic model
is based on the Newton laws in order to calculate the emotional attraction
among them. To obtain the emotions we use a NAO robot as a tool
to move around of a real environment for interacting with the humans.
The robot obtains the emotions through image processing. Moreover, the
robot can start a dialogue game with humans in order to estimate the
personality of a new individual.This work is partially supported by the MINECO project TIN2015-65515-C4-1-
R and the FPI grant AP2013-01276 awarded to Jaime-Andres Rincon
Detecting emotions through non-invasive wearables
Current research on computational intelligence is being conducted in order to emulate and/or detect emotional states using specific devices such as wristbands or similar wearables. In this sense, this paper proposes the use of intelligent wristbands for the automatic detection of emotional states in order to develop an application which allows us to extract, analyse, represent and manage the social emotion of a group of entities. Nowadays, most of the existing approaches are centred in the emotion detection and management of a single entity. The designed system has been developed as a multi-agent system where each agent controls a wearable device and is in charge of detecting individual emotions based on bio-signals
An affective personal trainer for elderly people
The main goal of this paper is to try to increase the comfort and well-being of older people through the employment of some kind of automated processes that simplify daily work. So, this paper presents a prototype of an affective personal robotic trainer which, together with a non-invasive sensor, allows caregivers to monitor certain physical activities in order to improve their performance. In addition, the proposed system also takes into account how the person feels during the performance of the physical exercises and thus, determine more precisely if the exercise is appropriate or not for a specific person.e Spanish Government (RTI2018-095390-B-C31) and FCT—Fundação
para a CiĂŞncia e Tecnologia through the Post-Doc scholarship SFRH/BPD/102696/2014 (A. Costa)
and UID/CEC/00319/201
Nego-bot: a human-robot negotiation system
In this paper we present a platform composed of a low-cost robot and a multi-agent system that uses deep learning algorithms, whose objective is to establish a negotiation process and persuasively sell items, maximising their price, thus gain. To do this, we have focused on developing an interactive process that is able to interact with humans using a camera, microphone and speaker, to establish all negotiation process without physical contact. This is relevant due to the current COVID-19 situation and arisen issues of human contact. Validation processes with university students have revealed high interest and success in products’ negotiation.This work was partly supported by the Spanish Government (RTI2018-095390-
B-C31) and Universitat Politecnica de Valencia Research Grant PAID-10-19
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