145 research outputs found
Sistema de bloque de tierra compactado frente a la normatividad mexicana
La normatividad mexicana para el sistema constructivo de Bloque de Tierra Comprimida (BTC), no incluye información y requerimientos que sean específicos para la producción y uso del material en el país. La falta de una correcta regulación de este material provoca su desuso, quitando la posibilidad de ser una opción para vivienda sustentable. Este proyecto pretende establecer los criterios regulatorios para que el BTC pueda ser incluido a las normativas oficiales, según sus requerimientos para ladrillo recocido y así, los profesionistas, usuarios y agentes gubernamentales tengan la seguridad de utilizar un material validado regulado que cuenta con los parámetros para la construcción.
Para este trabajo de investigación, se realizó un análisis de normativas para BTC en otros países, esto permitió identificar los vacíos existentes en la ley. Se realizaron diferentes ensayos en laboratorio que determinaron las características mecánicas y estructurales del sistema constructivo, también, se obtuvo un estudio de impacto ambiental y valoración económica, con la finalidad de destacar las ventajas del material
Quantum simulation of entanglement dynamics in a quantum processor
We implement a five-qubit protocol in IBM quantum processors to get
entanglement dynamics in a two qubit system in the presence of an environment.
Specifically, two qubits represent the main system, another two qubits the
environment, and an additional qubit is used as an auxiliary qubit to perform
the quantum entanglement estimation. We focus on measuring, in this
superconducting quantum processor, the sudden death and sudden birth of
entanglement. We obtain the quantum entanglement evolution of the main system
qubits and the environment qubits as the average of independent
experiments in the same quantum device, observing that the noisy nature of
current quantum processors produce a shift on times signaling sudden death o
sudden birth of entanglement. This work takes relevance showing the usefulness
of current noisy quantum devices to test fundamental concepts in quantum
information.Comment: 6 pages, and 12 figure
Portfolio Optimization with Digitized-Counterdiabatic Quantum Algorithms
We consider digitized-counterdiabatic quantum computing as an advanced
paradigm to approach quantum advantage for industrial applications in the NISQ
era. We apply this concept to investigate a discrete mean-variance portfolio
optimization problem, showing its usefulness in a key finance application. Our
analysis shows a drastic improvement in the success probabilities of the
resulting digital quantum algorithm when approximate counterdiabatic techniques
are introduced. Along these lines, we discuss the enhanced performance of our
methods over variational quantum algorithms like QAOA and DC-QAOA.Comment: 8 pages, 4 figure
Piggy Bank: Experience the Semantic Web Inside Your Web Browser
The original publication is available at www.springerlink.com
http://dx.doi.org/10.1007/11574620_31The Semantic Web Initiative envisions a Web wherein information is offered free of presentation, allowing more effective exchange and mixing across web sites and across web pages. But without substantial Semantic Web content, few tools will be written to consume it; without many such tools, there is little appeal to publish Semantic Web content.
To break this chicken-and-egg problem, thus enabling more flexible information access, we have created a web browser extension called Piggy Bankthat lets users make use of Semantic Web content within Web content as users browse the Web. Wherever Semantic Web content is not available, Piggy Bank can invoke screenscrapers to restructure information within web pages into Semantic Web format. Through the use of Semantic Web technologies, Piggy Bank provides direct, immediate benefits to users in their use of the existing Web. Thus, the existence of even just a few Semantic Web-enabled sites or a few scrapers already benefits users. Piggy Bank thereby offers an easy, incremental upgrade path to users without requiring a wholesale adoption of the Semantic Web’s vision.
To further improve this Semantic Web experience, we have created Semantic Bank, a web server application that lets Piggy Bank users share the Semantic Web information they have collected, enabling collaborative efforts to build sophisticated Semantic Web information repositories through simple, everyday’s use of Piggy Bank
A reverse engineering approach to the suppression of citation biases reveals universal properties of citation distributions
The large amount of information contained in bibliographic databases has
recently boosted the use of citations, and other indicators based on citation
numbers, as tools for the quantitative assessment of scientific research.
Citations counts are often interpreted as proxies for the scientific influence
of papers, journals, scholars, and institutions. However, a rigorous and
scientifically grounded methodology for a correct use of citation counts is
still missing. In particular, cross-disciplinary comparisons in terms of raw
citation counts systematically favors scientific disciplines with higher
citation and publication rates. Here we perform an exhaustive study of the
citation patterns of millions of papers, and derive a simple transformation of
citation counts able to suppress the disproportionate citation counts among
scientific domains. We find that the transformation is well described by a
power-law function, and that the parameter values of the transformation are
typical features of each scientific discipline. Universal properties of
citation patterns descend therefore from the fact that citation distributions
for papers in a specific field are all part of the same family of univariate
distributions.Comment: 9 pages, 6 figures. Supporting information files available at
http://filrad.homelinux.or
Universality of Performance Indicators based on Citation and Reference Counts
We find evidence for the universality of two relative bibliometric indicators
of the quality of individual scientific publications taken from different data
sets. One of these is a new index that considers both citation and reference
counts. We demonstrate this universality for relatively well cited publications
from a single institute, grouped by year of publication and by faculty or by
department. We show similar behaviour in publications submitted to the arXiv
e-print archive, grouped by year of submission and by sub-archive. We also find
that for reasonably well cited papers this distribution is well fitted by a
lognormal with a variance of around 1.3 which is consistent with the results of
Radicchi, Fortunato, and Castellano (2008). Our work demonstrates that
comparisons can be made between publications from different disciplines and
publication dates, regardless of their citation count and without expensive
access to the whole world-wide citation graph. Further, it shows that averages
of the logarithm of such relative bibliometric indices deal with the issue of
long tails and avoid the need for statistics based on lengthy ranking
procedures.Comment: 15 pages, 14 figures, 11 pages of supplementary material. Submitted
to Scientometric
Fast Measure of Visual Acuity and Contrast Sensitivity Defocus Curves with an iPad Application
Objective: To evaluate the repeatability of the fast measurement of the visual acuity (VADC) and contrast sensitivity (CSDC) defocus curves with a new test as well as the agreement of measurements at far distance obtained with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart and the ClinicCSF test for measuring Contrast Sensitivity Function (CSF). Method: Records from fifty-nine subjects implanted with Multifocal Intraocular Lenses (MIOLs) were retrieved from our database. VADC and CSDC were measured from +1.00 D to -4.00 D in 0.50 D steps. The agreement with the ETDRS and the CSF at far distance was assessed in comparison to the 0 D location of the VADC and the CSDC, respectively. The repeatability was evaluated in 34 subjects who consecutively repeated two measures. Results: Median Visual Acuity (VA) was -0.1 logMAR with the VADC at 0 D of defocus and 0 logMAR with the ETDRS (p>0.05). A total of 45.8% of eyes showed no differences between both tests and the difference was less than one line of VA in 96.6% of the eyes. The intrasubject repeatability was under one line of VA along all the defocus curve except for positive defocus levels. The CSDC showed the best agreement with the CSF for 18 cycles per degree. The CSDC was less repeatable than VADC. Mean time spent on completing the VADC and CSDC was 7.81 and 7.98 minutes, respectively. Conclusion: The VADC showed good agreement with the ETDRS and good repeatability despite the short testing time. In contrast, poorer repeatability was found for CSDC. Our method would facilitate the inclusion of VADC in clinical practice as it is a fast test, being also the first one including the measure of CSDC
Induction of Lysosome Membrane Permeabilization as a Therapeutic Strategy to Target Pancreatic Cancer Stem Cells
Despite significant efforts to improve pancreatic ductal adenocarcinoma (PDAC) clinical outcomes, overall survival remains dismal. The poor response to current therapies is partly due to the existence of pancreatic cancer stem cells (PaCSCs), which are efficient drivers of PDAC tumorigenesis, metastasis and relapse. To find new therapeutic agents that could efficiently kill PaCSCs, we screened a chemical library of 680 compounds for candidate small molecules with anti-CSC activity, and identified two compounds of a specific chemical series with potent activity in vitro and in vivo against patient-derived xenograft (PDX) cultures. The anti-CSC mechanism of action of this specific chemical series was found to rely on induction of lysosomal membrane permeabilization (LMP), which is likely associated with the increased lysosomal mass observed in PaCSCs. Using the well characterized LMP-inducer siramesine as a tool molecule, we show elimination of the PaCSC population in mice implanted with tumors from two PDX models. Collectively, our approach identified lysosomal disruption as a promising anti-CSC therapeutic strategy for PDAC
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