717 research outputs found
The Alperin Weight Conjecture and the Glauberman correspondence via character triples
Recently, G. Navarro introduced a new conjecture that unifies the Alperin
Weight Conjecture and the Glauberman correspondence into a single statement. In
this paper, we reduce this problem to simple groups and prove it for several
classes of groups and blocks. Our reduction can be divided into two steps.
First, we show that assuming the so-called Inductive (Blockwise) Alperin Weight
Condition for finite simple groups, we obtain an analogous statement for
arbitrary finite groups, that is, an automorphism-equivariant version of the
Alperin Weight Conjecture inducing isomorphisms of modular character triples.
Then, we show that the latter implies Navarro's conjecture for each finite
group
Melodic track identification in MIDI files considering the imbalanced context
In this paper, the problem of identifying the melodic track of a MIDI file in imbalanced scenarios is addressed. A polyphonic MIDI file is a digital score that consists of a set of tracks where usually only one of them contains the melody and the remaining tracks hold the accompaniment. This leads to a two-class imbalance problem that, unlike in previous work, is managed by over-sampling the melody class (the minority one) or by under-sampling the accompaniment class (the majority one) until both classes are the same size. Experimental results over three different music genres prove that learning from balanced training sets clearly provides better results than the standard classification proces
Additional Physical Interventions to Conventional Physical Therapy in Parkinson’s Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
Parkinson's disease (PD) represents the second most common neurodegenerative disease. Currently, conventional physical therapy is complemented by additional physical interventions with recreational components, improving different motor conditions in people with PD. This review aims to evaluate the effectiveness of additional physical interventions to conventional physical therapy in Parkinson's disease. A systematic review and meta-analysis of randomized controlled trials were performed. The literature search was conducted in PubMed, Physiotherapy Evidence Database (PEDro), Scopus, SciELO and Web of Science. The PEDro scale was used to evaluate the methodological quality of the studies. A total of 11 randomized controlled trials were included in this review. Five of them contributed information to the meta-analysis. The statistical analysis showed favorable results for dance-based therapy in motor balance: (Timed Up and Go: standardized mean difference (SMD) = −1.16; 95% Confidence Interval (CI):(−2.30 to −0.03); Berg Balance Scale: SMD = 4.05; 95%CI:(1.34 to 6.75)). Aquatic interventions showed favorable results in balance confidence (Activities-Specific Balance Confidence: SMD=10.10; 95%CI:(2.27 to 17.93)). The results obtained in this review highlight the potential benefit of dance-based therapy in functional balance for people with Parkinson's disease, recommending its incorporation in clinical practice. Nonetheless, many aspects require clarification through further research and high-quality studies on this subject
Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures
A compact cryogenic Kerr microscope for operation in the small volume of
high-field magnets is described. It is suited for measurements both in Voigt
and Faraday configuration. Coupled with a pulsed laser source, the microscope
is used to measure the time-resolved Kerr rotation response of semiconductor
microstructures with ~1 micron spatial resolution. The microscope was designed
to study spin transport, a critical issue in the field of spintronics. It is
thus possible to generate spin polarization at a given location on a
microstructure and probe it at a different location. The operation of the
microscope is demonstrated by time-resolved measurements of micrometer distance
diffusion of spin polarized electrons in a GaAs/AlGaAs heterojunction quantum
well at 4.2 K and 7 Tesla
Suppressed spin dephasing for 2D and bulk electrons in GaAs wires due to engineered cancellation of spin-orbit interaction terms
We report a study of suppressed spin dephasing for quasi-one-dimensional
electron ensembles in wires etched into a GaAs/AlGaAs heterojunction system.
Time-resolved Kerr-rotation measurements show a suppression that is most
pronounced for wires along the [110] crystal direction. This is the fingerprint
of a suppression that is enhanced due to a strong anisotropy in spin-orbit
fields that can occur when the Rashba and Dresselhaus contributions are
engineered to cancel each other. A surprising observation is that this
mechanisms for suppressing spin dephasing is not only effective for electrons
in the heterojunction quantum well, but also for electrons in a deeper bulk
layer.Comment: 5 pages, 3 figure
A distance for partially labeled trees
In a number of practical situations, data have structure and the relations among its component parts need to be coded with suitable data models. Trees are usually utilized for representing data for which hierarchical relations can be defined. This is the case in a number of fields like image analysis, natural language processing, protein structure, or music retrieval, to name a few. In those cases, procedures for comparing trees are very relevant. An approximate tree edit distance algorithm has been introduced for working with trees labeled only at the leaves. In this paper, it has been applied to handwritten character recognition, providing accuracies comparable to those by the most comprehensive search method, being as efficient as the fastest.This work is supported by the Spanish Ministry projects DRIMS (TIN2009-14247-C02), and Consolider Ingenio 2010 (MIPRCV, CSD2007-00018), partially supported by EU ERDF and the Pascal Network of Excellence
The N-terminal domains of syntaxin 7 and vti1b form three-helix bundles that differ in their ability to regulate SNARE complex assembly
The SNAREs syntaxin 7, syntaxin 8, vti1b, and endobrevin/VAMP8 function in the fusion of late endosomes. Although the core complex formed by these SNAREs is very similar to the neuronal SNARE complex, it differs from the neuronal complex in that three of the four SNAREs contain extended N-terminal regions of unknown structure and function. Here we show that the N- terminal regions of syntaxin 7, syntaxin 8, and vti1b contain well folded a-helical domains. Multidimensional NAIR spectroscopy revealed that in syntaxin 7 and vti1b, the domains form three-helix bundles resembling those of syntaxin 1, Sso1p, and Vam3p. The three-helix bundle domain of vti1b is the first of its kind identified in a SNARE outside the syntaxin family. Only syntaxin 7 adopts a closed conformation, whereas in vti1b and syntaxin 8, the N-terminal domains do not interact with the adjacent SNARE motifs. Accordingly, the rate of SNARE complex assembly is retarded about 7-fold when syntaxin 7 contains its N-terminal domain, whereas the N-terminal domains of vti1b and syntaxin 8 have no influence on assembly kinetics. We conclude that three-helix bundles represent a common fold for SNARE N- terminal domains, not restricted to the syntaxin family. However, they differ in their ability to adopt closed conformations and thus to regulate the assembly of SNARE complexes
Adequacy of existing circular economy assessment tools for higher education institutions
[EN] Circular economy (CE) has been identified as a key strategy to contribute to sustainable development and the achievement of the Sustainable Development Goals of the 2030 Agenda. In this context, organisations have started to demand methods to measure and monitor their level of circularity. To facilitate this task, several CE tools have been developed in recent years, which automatically measure, track and communicate the level of circularity of organisations based on answers to qualitative questions. In particular, Higher Education Institutions (HEIs), as organisations engaged in education, research and community services, play an important role in promoting sustainability and should be an example in the transition process towards CE. Therefore, they need approaches that allow them to measure and monitor their transition towards CE. The aim of this study is to analyse the adequacy of existing CE tools for HEIs, to check whether they consider the specificities of HEIs and to identify the required changes to make them suitable for HEIs. For this purpose, seven existing CE tools were applied to four Spanish HEIs, and were analysed and evaluated through interviews with the environmental managers of these HEIs. The results show that the existing CE tools need to be reformulated in order to make them suitable for assessing the level of circularity of HEIs and to make their outputs useful for decision-making. As a conclusion, it has been found that it is better to develop a specific CE tool for HEIs, in order to incorporate the specificities and peculiarities of such complex type of organisation, including the teaching, research and management areas.Acknowledgements The authors are grateful to the Ministerio de Ciencia, Innovaci ' on y Universidades (Spain) (FPU18/02816) for the financial support and to the respondents from the organisations for their participation in this study.Valls-Val, K.; Ibañez-Forés, V.; Lo-Iacono-Ferreira, VG.; Capuz-Rizo, SF.; Bovea, MD. (2023). Adequacy of existing circular economy assessment tools for higher education institutions. Sustainable Production and Consumption. 39:399-413. https://doi.org/10.1016/j.spc.2023.05.0113994133
Optical probing of spin dynamics of two-dimensional and bulk electrons in a GaAs/AlGaAs heterojunction system
We present time-resolved Kerr rotation measurements of electron spin dynamics
in a GaAs/AlGaAs heterojunction system that contains a high-mobility
two-dimensional electron gas (2DEG). Due to the complex layer structure of this
material the Kerr rotation signals contain information from electron spins in
three different layers: the 2DEG layer, a GaAs epilayer in the heterostructure,
and the underlying GaAs substrate. The 2DEG electrons can be observed at low
pump intensities, using that they have a less negative g-factor than electrons
in bulk GaAs regions. At high pump intensities, the Kerr signals from the GaAs
epilayer and the substrate can be distinguished when using a barrier between
the two layers that blocks intermixing of the two electron populations. This
allows for stronger pumping of the epilayer, which results in a shift of the
effective g-factor. Thus, three populations can be distinguished using
differences in g-factor. We support this interpretation by studying how the
spin dynamics of each population has its unique dependence on temperature, and
how they correlate with time-resolved reflectance signals.Comment: 14 pages, 7 figure
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