Search results for "swa"
showing 10 items of 430 documents
Preliminary study on analysis and removal of wax from a Carrara marble statue
2015
This preliminary study has mainly focused on the wax identification by nuclear magnetic resonance (NMR) and removal. Wax is used for many purposes in the field of art as protective coatings on wooden, stone or metal objects. From the comparison of the spectra H NMR and in particular with the correspondence of the resonance peaks of the samples taken from the statue and beeswax and paraffin, we can conclude that the wax applied on the statue surface is beeswax. From our data, it can be concluded that, to remove the beeswax, from any stone support, the more effective solvent is the mixture of cyclohexane/ethyl acetate. The removal percentages ranged from 19 to 99%. Lower percentages of remova…
Infantilas rīšanas paradumi un citas orofaciālā kompleksa atradnes pirmsskolas vecuma bērniem Latvijā
2019
Ievads: Pētījuma mērķis bija izpētīt saikni starp infantilas rīšanas paradumiem ar citām orofaciālā kompleksa atradnēm pirmsskolas vecuma bērniem Latvijā. Paralēli tam mēs pētījām arī oklūziju. Metodes: Šajā šķērsgriezuma pētījumā piedalījās 141 pirmsskolas vecuma bērnu no 4 līdz 7 gadiem un viņu mātes. Orofaciālā kompleksa izmeklēšanu veica divi ortodonti, kurā tika novērtēta orofaciālā kompleksa miofunkcionālā situācija, oklūzija un bērnu runas defekti. Mātēm tika sniegtas anketas, lai iegūtu informāciju par bērnu veselības stāvokli un citiem identifikācijas datiem. Tika veikta aprakstoša statistika visiem pētījuma mainīgajiem lielumiem un vienvirziena analīze starp infantilo rīšanu un vi…
Another Look at Value and Momentum: Volatility Spillovers
2017
This paper examines volatility interdependencies between value and momentum returns. Using U.S. data over the period 1926-2015, we document persistent periods of low and high volatility spillovers between value and momentum strategies. Moreover, we find that the intensity of the volatility spillovers may change substantially in very short periods of time and that these shifts in spillover intensity can be linked to prominent economic events and financial market turmoil. Our results further demonstrate that value returns increase and momentum returns decrease monotonically with increasing volatility spillovers between the two strategies. Given this linkage between spillover intensity and ret…
Monochromatic Long-Period Seismicity Prior to the 2012 Earthquake Swarm at Little Sitkin Volcano, Alaska
2021
Detection of the earliest stages of unrest is one of the most challenging and yet critically needed aspects of volcano monitoring. We investigate a sequence of five unusual long-period (LP) earthquakes that occurred in the days prior to the onset of a months-long volcano-tectonic (VT) earthquake swarm beneath Little Sitkin volcano in the Aleutian Islands during late 2012. The long-period earthquakes had two distinctive characteristics: their signals were dominated by a monochromatic spectral peak at approximately 0.57 Hz and they had impulsive P and S-wave arrivals on a seismometer located on Amchitka Island 80 km to the southeast of the volcano. In each case, the monochromatic earthquakes …
Caracterización proteómica de la interacción y la inserción de proteínas de membrana
2019
Las proteínas de membrana tienen funciones muy diversas en la célula, desde controlar el tráfico molecular hasta facilitar la transducción de señales. Sin embargo, el estudio de estas proteínas supone todo un reto por sus particulares características fisico-químicas. Su naturaleza hidrofóbica requiere un elevado control durante su síntesis. Uno de los pasos críticos en esta síntesis es la inserción en la bicapa lipídica. Generalmente, este proceso se produce a través de un mecanismo (co-traduccional) acoplado al proceso de traducción. Esta vía co-traduccional ha sido ampliamente estudiada y la maquinaria implicada en el proceso se conoce con bastante profundidad. Sin embargo, algunas proteí…
The Effects of Stochastic Galvanic Vestibular Stimulation on Body Sway and Muscle Activity
2020
Objective: This study aimed to investigate whether galvanic vestibular stimulation with stochastic noise (nGVS) modulates the body sway and muscle activity of the lower limbs, depending on visual and somatosensory information from the foot using rubber-foam.Methods: Seventeen healthy young adults participated in the study. Each subject maintained an upright standing position on a force plate with/without rubber-foam, with their eyes open/closed, to measure the position of their foot center of pressure. Thirty minutes after baseline measurements under four possible conditions (eyes open/closed with/without rubber-foam) performed without nGVS (intensity: 1 mA, duration: 40 s), the stimulation…
Anodal transcranial direct current stimulation and intermittent theta-burst stimulation improve deglutition and swallowing reproducibility in elderly…
2019
Background: Dysphagia in the elderly, known as presbydysphagia, has become a relevant public health problem in several countries. Swallowing disorders may be a consequence of different neurological disorders (secondary presbydysphagia) or the expression of the aging process itself (primary presbydysphagia). We aimed to test the therapeutic potential of two different non-invasive brain stimulation (NIBS) techniques in subjects with primary or secondary presbydysphagia. Methods: A blinded randomized controlled trial with crossover design was carried out in 42 patients, randomly assigned to anodal transcranial direct current stimulation (tDCS) or intermittent theta-burst stimulation (TBS) grou…
Is karate effective in improving postural control?
2012
Background: Performing complex motor skills, such as the ones performed by karate athletes, requires a great sense of balance. Because the posturo-kinetic performance seems to be improved by sport practice, especially by sports involving a lot of posturokinetic activities, the aim of this review was to critically analyse the scientific literature in order to appraise whether any positive correlation between karate and improved postural control is scientifically supported. Material/Methods: The online search engines Scirus and Medline were used for generating the data. A comprehensive literature search was conducted based on the following keywords: “karate”, “postural control” and “body sway…
From pseudo-bosons to pseudo-Hermiticity via multiple generalized Bogoliubov transformations
2016
We consider the special type of pseudo-bosonic systems that can be mapped to standard bosons by means of generalized Bogoliubov transformation and demonstrate that a pseudo-Hermitian systems can be obtained from them by means of a second subsequent Bogoliubov transformation. We employ these operators in a simple model and study three different types of scenarios for the constraints on the model parameters giving rise to a Hermitian system, a pseudo-Hermitian system in which the second the Bogoliubov transformations is equivalent to the associated Dyson map and one in which we obtain D-quasi bases.
Memetic Algorithms in Engineering and Design
2012
When dealing with real-world applications, one often faces non-linear and nondifferentiable optimization problems which do not allow the employment of exact methods. In addition, as highlighted in [104], popular local search methods (e.g. Hooke-Jeeves, Nelder Mead and Rosenbrock) can be ill-suited when the real-world problem is characterized by a complex and highly multi-modal fitness landscape since they tend to converge to local optima. In these situations, population based meta-heuristics can be a reasonable choice, since they have a good potential in detecting high quality solutions. For these reasons, meta-heuristics, such as Genetic Algorithms (GAs), Evolution Strategy (ES), Particle …