590 research outputs found
Classical properties of algebras using a new graph association
We study the relation between algebraic structures and Graph Theory. We have
defined five different weighted digraphs associated to a finite dimensional
algebra over a field in order to tackle important properties of the associated
algebras, mainly the nilpotency and solvability in the case of Leibniz
algebras
Descripción del Perfil Lector de una Revista Científica de Audiología para profesionales del área audiológica Hispanohablantes
Audiologists are recognized in Spain and most countries in Latin America and have practised in various fields for more than 40 years. Despite this, a paucity of information exists regarding audiologists’ engagement with scientific journals both as readers and authors alike. The aim of this paper was to describe the scientific-disciplinary reader profile of Spanish-speaking audiology professionals. A questionnaire was distributed online with 16 questions grouped into two sections: 1) General and demographic data and 2) Readership profile. A total of 200 questionnaires were completed. With the results, a qualitative analysis was performed and a summary was written for each question.
General audiology and hearing aids/amplification systems were found to be the areas of greatest interest among respondents (74% and 71%, respectively). In the readership profile section, 66% of respondents reported consulting scientific journals (at least once a month). The most common reason, given by 51% in this group, was to keep up to date. However, 81% of respondents reported never having published in a peer-reviewed journal. The main reason for not publishing was lack of confidence to write an article (51%). Despite audiologists showing a keen interest in reading audiology journals, only a small proportion submits articles for publication.El profesional audiólogo se encuentra reconocido en la mayoría de los países de Iberoamérica desempeñando sus funciones en diversas áreas desde hace más de 40 años. A pesar esto aún existe escasa información en relación a la vinculación con revistas científicas, ya sea como lectores y/o autores. El objetivo del presente trabajo fue la caracterización del profesional del área de la audiología en Iberoamérica como lector de una revista científica de audiología en Castellano. Un total de 200 cuestionarios fueron respondidos.
En relación al perfil del lector, se reporta que un 66% de los participantes consulta revistas científicas (una o más veces al mes), siendo la actualización (51%) el motivo más frecuente dentro de este grupo. Sin embargo, un 81% de los participantes refiere no tener experiencia publicando en una revista revisada por pares, siendo inseguridad para escribir un artículo (51%) como la razón principal
Temporal analysis of natural radionuclides deposition at Málaga(2005-2016)
Atmospheric deposition of radionuclides has been investigated in many studies from the aspects of both
radiation protection and geochemistry. The present study, carried out in the city of Málaga, in the southeast
of Spain, focuses on the assessment of the bulk depositional fluxes of three natural radionuclides: 7Be
(cosmogenic origin), and 210Pb and 40K (crustal origin). These three radionuclides are useful markers of
particles arising from their respective sources. To obtain fundamental information of atmospheric
transportation, sedimentation and geological process of particulate matter, a long-term monitoring of
atmospheric deposition has been carried out in Málaga from January 2005-December 2016. Samples of
bulk deposition were collected on a monthly basis on a stainless steel tray from January 2005 to
December 2016. Afterwards, a volume of 6 L of the bulk deposition was reduced via evaporation to 1 L
approximately and transferred to a Marinelli geometry container for gamma counting. Additionally,
aerosols samples were collected weekly in cellulose membrane filters of 0.8μm pore size and 47mm
diameter with an air sampler lodged in an all-weather sampling station, situated on the roof near the bulk
rain collector. Gamma counting of the aerosols and bulk deposition samples was performed using an
intrinsic germanium coaxial detector, Re-Ge-type (CANBERRA). This study describes the results and
then discusses characteristics of atmospheric deposition of mentioned radionuclides with respect to
seasonal variations and dependency on controlling factors. The depositional fluxes of all radionuclides
showed a clear seasonal trend with summer minimum and high values in wintertime
Speech, Spatial, Qualities of Hearing Scale – versión de 12 preguntas: sugerencias y consideraciones de aplicación
Hearing questionnaires are extremely useful tools for describing people's hearing abilities and for measuring and documenting hearing device fitting outcomes. The Speech, Spatial and Qualities of Hearing Scale (SSQ) questionnaire is often used and is even available in different versions and formats. However, detailed instructions and guidance for the clinician administering the questionnaire are limited. Below are some suggestions and guidance for reducing variability when administering the questionnaire, thereby maintaining consistency in both clinical and research settings alike.Los cuestionarios para evaluar la función auditiva son herramientas de gran utilidad para describir las habilidades auditivas de una persona que también permiten medir y documentar el resultado obtenido tras una adaptación de dispositivos auditivos. El uso del cuestionario Speech, Spatial and Qualities of Hearing Scale (SSQ) es frecuente, incluso cuenta con diferentes versiones y formatos de aplicación, aunque la información detallada sobre las instrucciones para el evaluador y las consideraciones de aplicación son limitadas. A continuación se presentan algunas consideraciones y sugerencias con el objetivo de disminuir la variabilidad en su aplicación y así mantener la sistematicidad tanto en contextos clínicos como de investigación.
Osteocondritis de los sesamoideos del hallux: revisión de la literatura a propósito de un caso
La osteocondritis de los sesamoideos del hallux es una afección poco frecuente que puede afectar tanto al sesamoideo medial como al lateral. Presentamos un caso de osteocondritis del sesamoideo externo en una mujer de 27 años, con clínica de dolor de un año de evolución, que se resolvió satisfactoriamente con la excisión quirúrgica del mismo. Comparamos el tratamiento realizado con otros publicados, realizando una revisión de la literatura con respecto a sus causas, los métodos diagnósticos y los tratamientos empleados.Osteochondritis of the sesamoid bones is an unfrequent condition wich may affect both the medial and lateral hallux sesamoids. We report a case of osteochondritis of the external sesamoid in a 27 years old woman, with a one year clinical pain evolution, wich was satisfactory solved by carrying out its surgical excision. We compare the treatment carried out with others that have been published, reviewing the literature that refers to its causes, the diagnostic methods and treatment use
El ácido úrico se asocia con características de un síndrome de resistencia insulínica en los niños obesos en etapas perdurables
Elevated plasma uric acid levels are associated with obesity
and could be an expression of insulin-resistant state.
The aim of the present study was to evaluate plasma uric
acid in obese and normal-weight children exclusively at prepubertal
stage and its relationship with anthropometric
measurements, intake, and features of the insulin resistance
syndrome. A study was performed in 34 obese and 20 normal-
weight prepubertal children. Nutrient intake was
determined using a 72 h recall questionnaire and a consumption
food frequency questionnaire. Anthropometric
parameters and fasting plasma lipids, glucose, insulin, leptin,
adiponectin, tumour necrosis factor (TNF-α) and uric
acid were measured. Multiple regression analysis was used
to identify association of anthropometric parameters, nutrient
intake and insulin resistance syndrome variables (arterial
blood pressure, plasma glucose, insulin, homeostasis
model assessment of insulin resistance index- HOMA- triacylglycerols
and, HDL-cholesterol) with uric acid. Plasma
uric concentration was significantly higher in the obese
group than in the control group and when adjusted by sex,
age and BMI was positively associated with tricipital skinfold
and insulin resistance, and negatively with adiponectin.
In multiple regression analysis, BMI, HDL-cholesterol and
adiponectin were independent predictors of plasma uric
acid. In conclusion, elevated levels of uric acid in obese children,
compared with lean subjects, at the prepubertal
period, seems to be an early metabolic alteration that is associated
with other features of insulin resistance syndrome.Los niveles elevados de ácido úrico plasmáticos se asocian
a la obesidad y pueden ser la expresión de un estado de
resistencia insulínica. El objetivo de este estudio ha sido
evaluar la concentración plasmática de ácido úrico en niños
obesos y normales, exclusivamente en edad prepuberal, y
determinar su relación con las medidas antropométricas, la
ingesta dietética y los parámetros asociados al síndrome de
resistencia insulínica. El estudio se llevó a cabo en 34 niños
obesos y 20 controles en edad prepuberal a los cuales se les
estimó su ingesta dietética mediante el registro de un cuestionario
de ingesta de alimentos de 72 h y un cuestionario de
frecuencia de consumo de alimentos y se determinaron,
además de los parámetros antropométricos, la glucosa, la
insulina, la leptina, la adiponectina y el factor de necrosis
tumoral alfa (TNF-α) plasmáticos. Se realizó un análisis de
regresión múltiple para identificar la asociación entre los
niveles de ácido úrico y los parámetros antropométricos, la
ingesta de nutrientes y las variables clásicas relacionadas
con el síndrome de resistencia insulínica (hipertensión, glucosa,
insulina, índice de resistencia insulínica HOMA, triglicéridos
y HDL-colesterol plasmáticos), así como con leptina,
adiponectina y TNF-α. La concentración plasmática
de ácido úrico fue significativamente más elevada en los
niños obesos que en los controles y, cuando se ajustó por
sexo, edad e índice de masa corporal, los niveles de ácido
úrico se asociaron con el pliegue tricipital y la resistencia
inulínica, y negativamente con la adiponectina. En el análisis
de regresión múltiple, el índice de masa corporal, el
HDL-colesterol y la adiponectina fueron predictores independientes
del ácido úrico plasmático. En conclusión, los
niveles elevados de ácido úrico en niños obesos en edad prepuberal,
comparado con los de los niños normales, representan
una alteración metabólica temprana asociada con la
resistencia insulínica.This work was supported by the Spanish Ministry of
Health and Consumer Affairs, the Spanish National Program
for Scientific Research, Development, and Technological
Innovation (I+D+I), and the Instituto de Salud
Carlos III (Spanish National Health Research Institute),
FEDER co-financed Project No. PI 051968. Mercedes
Gil-Campos was a research scientist appointed on a
training contract funded by the Carlos III Health
Research Institute
Electrochemical synthesis and magnetic properties of MFe_2O_4 (M = Fe, Mn, Co, Ni) nanoparticles for potential biomedical applications
In this study, we evaluate the magnetic properties and cytotoxic effect of magnetic nanoparticles (MNPs) based on magnetite and Mn, Co and Ni ferrites, obtained by electrochemical synthesis. These nanoparticles have almost spherical shape and an mode size of 9 +/- 1 nm. The electrochemical synthesis produces a single crystallographic phase with a spinel-like structure in all cases. Magnetization saturation at room temperature varies with the composition of the ferrites from M_S (Fe_3O_4) > M_S (MnFe_2O_4) > M_S (CoFe_2O_4) > M_S (NiFe_2O_4). Ferrite MNPs present low magnetic remanence indicating a superparamagnetic-like response at room temperature. However, the different values of magnetic anisotropy and size produce variations in the values of coercivity and susceptibility of the ferrite MNPs. The cytotoxicity of the different ferrites was evaluated by internalizing MNP in HeLa cancer cells. Although magnetite and Mn ferrite present low toxicity for all the concentrations studied, significant cytotoxic effect were observed when incubating the cells with high concentration of Co and Ni ferrites
Too cold for invasions? Contrasting patterns of native and introduced ascidians in subantarctic and temperate Chile
10 páginas, 1 tabla, 2 figuras.We analysed the biodiversity of ascidians in two areas located in southern and northern Chile: Punta Arenas in the Strait of Magellan (53º
latitude, subantarctic) and Coquimbo (29º latitude, temperate). The oceanographic features of the two zones are markedly different, with
influence of the Humboldt Current in the north, and the Cape Horn Current System, together with freshwater influxes, in the Magellanic
zone. Both regions were surveyed twice during 2013 by SCUBA diving and pulling ropes and aquaculture cages. Both artificial structures
and natural communities were sampled. A total of 22 species were identified, three of them reported for the first time in Chilean waters:
Lissoclinum perforatum, Synoicum georgianum, and Polyzoa minor. The first is an introduced species found here for the first time in the
Pacific. No species occurred in both regions, highlighting the very different environmental conditions of subantarctic vs. temperate waters. In
spite of exhaustive searches in aquaculture facilities and on artificial structures such as harbour docks and piers, no introduced species were
found in the Punta Arenas area. Conversely, 5 out of 11 (45%) species found in northern Chile were introduced. The Coquimbo area has a
history of ship traffic dating back at least 150 years, and cultures of native (e.g. scallop) as well as exotic species (e.g. abalone) have been
deployed for ca. 35 years. Some of the introduced species, such as Ciona robusta (formerly C. intestinalis sp. A), constitute pests for scallop
culture facilities in the area, causing serious losses to local farmers. It is surprising that the Punta Arenas zone, with a history of ship traffic
dating back ca. 500 years and over 25 years of sustained mussel and salmon aquaculture activity, is apparently free from introduced species.
The ascidian cover on artificial structures is high, but it is made up of native species such as Paramolgula sp., Cnemidocarpa verrucosa, or
Polyzoa opuntia. It is hypothesized that cold waters (5 to 11ºC) are the determining factor hindering the development of introduced ascidians,
which tend to be temperate-warm water species. The ongoing warming in the Southern Cone may change this picture and continued
monitoring is strongly advised.This research was
funded by CONICYT Chile (Grant 80122006). Additional
funding was obtained by XT from the Spanish Government
(project CHALLENGEN CTM2013-48163) and by JIC from
University of Magallanes - UMAG/DI&P Grant PR-F2-01CRN-
12, CIMAR 18 & CIMAR 20 Fjords Chilean Navy, and GAIAAntarctic
Project (MINEDUC-UMAG). RMR received a research
grant from CNPq–National Counsel of Technological and
Scientific Development (304768/2010-3).Peer reviewe
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