7,760 research outputs found
Single Molecule as a Local Acoustic Detector for Mechanical Oscillators
Biological and Soft Matter Physic
Key agreement protocols for distributed secure multicast over the ring Ep(m)
Protocols for authenticated key exchange allow parties within an insecure network to establish a common session key which can then be used to secure their future communication. In this paper we introduce a protocol for distributed key agreement over a noncommutative ring with a large number of noninvertible elements. This protocol uses polynomials with coefficients in the center of the ring. We also present the necessary steps for recalculating the shared secret key when a new user joins the system, or when a user leaves the system.The work of the first author was partially supported by Spanish grant MTM2011-24858 of the Ministerio de Economía y Competitividad of the Gobierno de España. The work of the second author was partially supported by the grant FQM 0211 of the Junta de Andalucía
Impact of effectual propensity on entrepreneurial intention
For decades, entrepreneurship has been promoted in academia and the tourism sector and seen as an opportunity for new business ventures. In entrepreneurial behaviour, effectual logic shows how individuals use their resources to create new opportunities. This paper aims to determine effectual propensity as an antecedent of entrepreneurial intentions. For this purpose, and based on the TPB model, we conducted our research with tourism students from Cadiz and Seville (Spain) universities with Smart PLS 3. The results show that effectual propensity influences entrepreneurial intentions and that attitude and perceived behavioural control mediate between subjective norms and intentions. Our research has a great added value since effectual propensity is studied for the first time as an antecedent of intentions in people who have never been entrepreneurs.Durante décadas, el emprendimiento ha sido promovido en la academia y el sector del turismo, siendo visto como una oportunidad para nuevas empresas. En el comportamiento emprendedor, la lógica efectual muestra cómo los individuos utilizan sus recursos para crear nuevas oportunidades. Este documento tiene como objetivo determinar la propensión efectual como un antecedente de las intenciones emprendedoras. Con este propósito, y basándonos en el modelo TPB, llevamos a cabo nuestra investigación con estudiantes de turismo de las universidades de Cádiz y Sevilla (España) utilizando Smart PLS 3. Los resultados muestran que la propensión efectual influye en las intenciones emprendedoras y que la actitud y el control conductual percibido median entre las normas subjetivas e intenciones. Nuestra investigación tiene un gran valor agregado, ya que la propensión efectual se estudia por primera vez como antecedente de intenciones en personas que nunca han sido emprendedoras
Traumatismo de la fisis distal de la tibia: tratamiento y resultados
Hemos realizado un estudio retrospectivo de 206 fracturas fisiarias distales de tibia. Se excluyeron las lesiones fisiarias aisladas de peroné y los arrancamientos óseos de tibia o peroné sin afectación de la placa fisiaria. Se recopilaron variables de 199 casos relativas al diagnóstico, tratamiento y evolución. La clasificación utilizada fue la de Salter y Harris para los traumatismos fisiarios. El tiempo de seguimiento medio fue de 7,73 meses (rango de 1,36 a 126 meses). Se trataba de 115 varones y 84 hembras. El tipo más frecuente fue el II (n=82, 41,2%). La media de edad fue de 12,1 ± 2,6 años. La causa más frecuente fue el accidente casual. Se realizó tratamiento conservador en 121 casos (60,8%). Los resultados se valoraron en función de las complicaciones aparecidas. En 169 casos (90,7%) el resultado fue satisfactorio, encontrando sólo 17 casos (9,3%) de malos resultados por presentar desalineación de los ejes (de 5 o más grados) y/o acortamiento (de 1 cm o más). Se presentó malposición en 9 casos (12%) en el tipo II, 4 casos (10,8%) en el tipo III, 1 caso (4%) en el tipo IV y 3 casos (100%) en el tipo V. La relación entre el grado de reducción obtenido y aparición de malposición sólo presentó diferencias significativas en los casos aparecidos del tipo II. La aparición de alteraciones de crecimiento en los tipos III y IV suele tener poca trascendencia clínica por ocurrir en pacientes con cartílagos en fase avanzada de cierre, no así en el tipo II donde pueden estar asociadas lesiones de tipo V, aconsejando realizar reducciones mediante maniobras cuidadosas para intentar evitar alteraciones.This is a retrospective study of 206 physeal fractures of the distal tibia. Isolated physeal injuries to the fibula and dislocations of the tibia or fibula without involvement of the growth plate were excluded. Variables from 199 cases relative to the diagnosis, treatment and evolution were recorded. The Salter-Harris classification was used for physeal fractures. The mean follow-up period was 7.73 months (range: 1.36 to 126 months), and 115 male and 84 female patients were treated. The most frequented type of fracture was type II (n=82, 41.2%). The mean age of the patients was 12.1 ± 2.6 years. The most frequented cause of injury was accident. In 121 cases (60.8%) the injury was treated conservatively. The results were evaluated in terms of subsequent complications. In 169 cases (90.7%) the results were satisfactory, and in only 17 cases (9.3%) the results were poor as a consequence of misalignment of the axes (5 or more degrees) and/or shortening (1 cm or more). Misalignment was found in 9 cases (12%) of type II, 4 cases (10.8%) of type III, 1 case (4%) of type IV and 3 cases (100%) of type V. The correlation between the degree of reduction obtained and the appearance of misalignment was statistically significant only in the cases of type II fracture. The appearance of growth disturbance in type III and type IV fractures is usually of minor clinical importance because it occurs in patients whose cartilage is at an advanced stage of closure, unlike type II fractures, which may be associated with type V injuries. In these cases reduction must be performed with special care in order to avoid growth disturbance
SoC architecture for acquisition and processing of the EMG signal
2023 38th Conference on Design of Circuits and Integrated Systems (DCIS), 15-17 November 2023, Málaga, Spain.EMG (electromyography) is a technique used to
measure the electrical activity of muscles and nerves, during
contraction and relaxation, and is used in a variety of clinical
and research applications. In particular, it is very useful for
the diagnosis and evaluation of neuromuscular disorders and
control electromechanical devices or prostheses. This signal has a
low SNR and needs to undergo conditioning processes including
amplification, filtering and digitisation for further processing.
In order to improve the SNR of the EMG signals, this work
describes a System-on-Chip (SoC) architecture for the acquisition
and processing of the EMG signals, offering a modular and
high performance solution. These signals could be applied to the
movement of a therapeutic exoskeleton with the aim of improving
active rehabilitation therapies for patients with incomplete spinal
cord injury. The proposed architecture provides a modular
solution that allows signal digitization, performed as close as
possible to the electrode and minimizing transmission losses,
signal noise and artifacts. In addition, sampling is performed at a
higher sampling rate than commercial acquisition systems, while
supporting significant processing throughput. The architecture
uses the ADS1298R integrated circuit for multichannel acquisition
and perform the correct conditioning of EMG signals, as well
as integrate the communication module through Serial Peripheral
Interface (SPI) interface to carry out the configuration and data
transfers. In this case, the acquired signal is processed using a
moving average-based algorithm and its thresholding to establish
the muscle activity. The identified muscle activity could be used
as an active reference to activate the therapeutic exoskeleton. The
results show the validation of the proposed architecture with an
EMG signal with a sampling rate of 8 kSPS.Agencia Estatal de Investigació
Constraining the Matter Power Spectrum Normalization using the SDSS/RASS and REFLEX Cluster surveys
We describe a new approach to constrain the amplitude of the power spectrum
of matter perturbations in the Universe, parametrized by sigma_8 as a function
of the matter density Omega_0. We compare the galaxy cluster X-ray luminosity
function of the REFLEX survey with the theoretical mass function of Jenkins et
al. (2001), using the mass-luminosity relationship obtained from weak lensing
data for a sample of galaxy clusters identified in Sloan Digital Sky Survey
commissioning data and confirmed through cross-correlation with the ROSAT
all-sky survey. We find sigma_8 = 0.38 Omega_0^(-0.48+0.27 Omega_ 0), which is
significantly different from most previous results derived from comparable
calculations that used the X-ray temperature function. We discuss possible
sources of systematic error that may cause such a discrepancy, and in the
process uncover a possible inconsistency between the REFLEX luminosity function
and the relation between cluster X-ray luminosity and mass obtained by Reiprich
& Bohringer (2001).Comment: Accepted to ApJ Letters. 4 pages using emulateapj.st
Zirconium Metal−Organic Polyhedra with Dual Behavior for Organophosphate Poisoning Treatment
Organophosphate nerve agents and pesticides are extremely
toxic compounds because they result in acetylcholinesterase (AChE)
inhibition and concomitant nerve system damage. Herein, we report the
synthesis, structural characterization, and proof-of-concept utility of
zirconium metal−organic polyhedra (Zr-MOPs) for organophosphate
poisoning treatment. The results show the formation of robust tetrahedral
cages [((n-butylCpZr)3(OH)3O)4L6]Cl6 (Zr-MOP-1; L = benzene-1,4-
dicarboxylate, n-butylCp = n-butylcyclopentadienyl, Zr-MOP-10, and L =
4,4′-biphenyldicarboxylate) decorated with lipophilic alkyl residues and
possessing accessible cavities of ∼9.8 and ∼10.7 Å inner diameters,
respectively. These systems are able to both capture the organophosphate
model compound diisopropylfluorophosphate (DIFP) and host and release
the AChE reactivator drug pralidoxime (2-PAM). The resulting 2-PAM@
Zr-MOP-1(0) host−guest assemblies feature a sustained delivery of 2-PAM under simulated biological conditions, with a
concomitant reactivation of DIFP-inhibited AChE. Finally, 2-PAM@Zr-MOP systems have been incorporated into biocompatible
phosphatidylcholine liposomes with the resulting assemblies being non-neurotoxic, as proven using neuroblastoma cell viability
assays.Spanish MCIN/AEI PID2020-113608RB-I00FEDER/Junta de Andalucia-Conserjeria de Economia y Conocimiento B-FQM-364-UGR18
B-FQM-006-UGR18FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades P18-RT-612
P20_00672Fondazione CRUIprograma Juan de la Cierva FormacionSpanish Government PID2020-118117RB-I00Center for Forestry Research & Experimentation (CIEF)European Commission SEJIGENT/2021/059
PROMETEU/2021/054La Caixa Foundation 100010434
LCF/BQ/PR20/11770014"Maria de Maeztu" Program for Centers of Excellence in RD CEX2019-000919-MH2020-MSCA-IF2019-888972-PSust-MO
Facies generadoras de carbón en el Westfaliense superior de la Cuenca Carbonífera Central Asturiana
La Cuenca Carbonífera Central Asturiana constituye una cuenca de antepais individualizada en la Zona Cantábrica durante el Carbonifero Superior coincidiendo con la máxima actividad de la orogenia Hercinica. Durante el Westfaliense, se acumularon en ella importantes volúmenes de material clástico procedentes de los relieves en elevación situados al W. Los abanicos aluviales costeros constituyeron unos sistemas deposicionales muy eficientes en la dispersión de estos materiales, generaron extensas cuñas clásticas en relación con las cuales se originaron capas de carbón explotables. En este trabajo se estudian varios litosomas de edad Westfaliense Superior que representan episodios progradantes de estos sistemas sobre ambientes marinos someros v de transición. El análisis e interpretación de sus facies y geometrías permite la reconstrucción de las condiciones ambientales en que se generaron las capas de carbón asociadas a cada una de las unidades estudiadas. Estas se desarrollaron: 1) en zonas marginales a los lóbulos progradantes y zonas interlóbulos y 2) sobre los mismos una vez que éstos fueron abandonados y previamente a su enterramiento
Sacroiliac joint radiographic progression - speed and determinants
Non-radiographic axial spondyloarthritis (nr-axSpA) and radiographic axial spondyloarthritis (r-axSpA) are considered to be different spectra of the same disease. Accumulating data suggest a low transition rate from nr-axSpA to r-axSpA in patients with early disease and identify inflammation, smoking and HLA-B27 positivity as factors associated with transition
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