3,382 research outputs found
Distribución vertical de la macrofauna en sedimentos contaminados del interior del puerto de Ceuta
Se ha estudiado la distribución vertical de la macrofauna y su relación con las variables fisicoquímicas
de los sedimentos contaminados del puerto de Ceuta. La obtención de las muestras se
llevó a cabo mediante buceo con escafandra autónoma y empleando instrumentos de muestreo
tipo core (10 cm × 17 cm × 35 cm), diferenciándose las siguientes profundidades en la columna
de sedimento: 0-2 cm, 2-5 cm, 5-10 cm y más de 10 cm. Los crustáceos Pariambus typicus Kröyer,
1844; Apseudes latreilli Milne-Edwards, 1820; Corophium runcicorne Della Valle, 1893; C. sextonae
Crawford, 1937; el molusco Parvicardium exiguum (Gmelin, 1791) y los poliquetos
Pseudomalacoceros tridentata (Southern, 1914) y Exogone verrugera Cleparede, 1868 se localizaron en
los dos primeros centímetros de sedimento, mientras que el molusco Loripes lacteus (L., 1758) y
los poliquetos Platynereis dumerilii Audouin y Milne-Edwards, 1833; Cirratulus cirratus (Muller,
1776) y Cirriformia tentaculata (Montagu, 1808) dominaron en los niveles más profundos, observándose
el incremento en el tamaño de los individuos con el aumento de la profundidad. Los
análisis multivariantes reflejaron que el porcentaje de pelitas, la materia orgánica total y, especialmente,
la relación lípidos malténicos/lípidos asfalténicos, fueron los principales factores condicionantes
de la distribución vertical de las especies en el sedimento.Vertical distribution of the macrofauna in polluted sediments from the harbour of Ceuta
Vertical distribution of the macrofauna and its relationship with physico-chemical parameters were studied
in polluted sediments from the harbour of Ceuta. The samples were collected with cores (10 cm × 17 cm ×
35 cm) by scuba divers. The following depths in the sediment column were included in the study: 0-2 cm, 2-
5 cm, 5-10 cm and more than 10 cm. The crustaceans Pariambus typicus Kröyer, 1844; Apseudes latreilli
Milne-Edwards, 1820; Corophium runcicorne Della Valle, 1893; C. sextonae Crawford, 1937; the mollusc
Parvicardium exiguum (Gmelin, 1791), and the polychaetes Pseudomalacoceros tridentata
(Southern, 1914) and Exogone verrugera Cleparede, 1868 were found in the first 2 cm of the sediment,
whereas the mollusc Loripes lacteus (L., 1758) and the polychaetes Platynereis dumerilii Audouin &
Milne Edwards, 1833; Cirratulus cirratus (Muller, 1776) and Cirriformia tentaculata (Montagu,
1808) were dominant in deeper strata, and size increased with depth. A multivariate analysis showed that
the percentage of silt and clays, the total organic matter, and especially, the maltenes/asphaltenes ratio, were
the main factors affecting species’ vertical distribution
The Sustainable Management of Metals: An Analysis of Global Research
The objective of this study was to analyze research trends in the field of sustainable management of metals on a global level between 1993 and 2017. To do so, a bibliometric analysis was carried out on a total of 6967 articles. The results revealed the growing interest in this research field, particularly over the last five year-period during which 63% of all articles were published. The three journals in which most articles had been published were the Journal of Cleaner Production, ACS Sustainable Chemistry and Engineering, and Chemsuschem. The countries that published the most articles were China, the United States, India, Germany, and the United Kingdom. A sizeable network of collaboration has been established between countries for the joint publication of studies. The main lines of research have been focused on metal decontamination in water and soil, waste management oriented towards reuse and recycling, and the innovation of processes for cleaner and more efficient production. The results revealed the need for comprehensive studies that integrate different disciplines within the same analytical framework, and to promote research that contributes to the different dimensions of sustainability (environmental, economic, and social)
A survey of the genera Sarcodictyon Forbes, 1847, and rolandia Lacaze-Duthiers, 1900, (anthozoa: octocorallia) in the North-eastern Atlantic and the Mediterranean
Sarcodictyon catenatum Forbes, 1847, is a common species in the Atlantic and the Mediterranean. However, often it has been mistaken for Rolandia coralloides Lacaze-Duthiers, 1900. On the basis of British and Mediterranean material we studied the main characters for distinguishing S. catenatum. We consider Rolandia coralloides Lacaze-Duthiers, 1900, to be a valid species and we assign to it all the material named Rolandia rosea by S. Weinberg (1978). Furthermore, a histological study confirmed that R. coralloides typically forms groups of polyps embedded in a common coenenchyme. Therefore, the possibility of transferring R. coralloides from Stolonifera to Alcyonacea is discussed. Evagorgia rosea Philippi, 1842, is here considered to be a nomen dubium
Onubactis rocioi gen. et spec. nov., a new species of Actiniidae (Anthozoa: Actiniaria) from the southern Iberian Peninsula
North-eastern Atlantic and Mediterranean species of Comulariidae Dana, 1846 (anthozoa: Stoloniferal) with the description of a new genus
Influence of lanthanum doping on the structure and transport properties of CeO2
LaxCe1-xO2-x/2 materials are oxide and/or proton conductors depending on the La-content and they are of interest for numerous electrochemical applications at high temperatures, including membranes for hydrogen separation and fuel cell electrolytes. Samples with low La-content exhibit (x0.4) crystallize with cubic fluorite type structure; while for x>0.4 the structure is still unclear. The crystal structure of these materials is still unknown, some authors reported that the materials exhibit fluorite type structure in the whole compositional range. However, another authors reported a pyrochlore type structure for x0.5. The stabilization of the fluorite or pyrochlore type structure depends mainly on the oxygen sublattice and the vacancy ordering1.
In this contribution, LaxCe1-xO2-δ (0<x0.7) materials are prepared by the freeze-drying precursor method and the sintering conditions have been optimized to obtain dense ceramic samples. A complete structural characterization has been carried out by X-ray powder diffraction and scanning electron microscopy. The average structure determined by conventional XRD indicates that the materials are single fluorite compounds for x0.6. However, the local structure determined by combined electron diffraction and HRTEM is more complex. The SAED patterns reveal diffuse scatterings for x0.5 that have been associated with O-vacancy ordering, leading to a superstructure relative to a single fluorite . This finding is further confirmed by the HRTEM images in the same zone axis. Thermogravimetric and Raman analysis confirmed an increase of oxygen vacancy concentration with La-doping. The overall conductivity was determined by complex impedance spectroscopy in different atmospheres. The samples with high La-content exhibit an important proton contribution at low temperature. In addition, all samples are mixed ion-electronic conductors in hydrogen containing atmosphereUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Associations between sedentary time, physical activity and bone health among older people using compositional data analysis
Introduction : Aging is associated with a progressive decrease in bone mass (BM), and being physical active is one of the main strategies to combat this continuous loss. Nonetheless, because daily time is limited, time spent on each movement behavior is co-dependent. The aim of this study was to determine the relationship between BM and movement behaviors in elderly people using compositional data analysis.
Methods : We analyzed 871 older people [395 men (76.9 +/- 5.3y) and 476 women (76.7 +/- 4.7y)]. Time spent in sedentary behavior (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA), was assessed using accelerometry. BM was determined by bone densitometry (DXA). The sample was divided according to sex and bone health indicators.
Results : The combined effect of all movement behaviors (PA and SB) was significantly associated with whole body, leg and femoral region BM in the whole sample (p<0.05), with leg and pelvic BM (p<0.05) in men and, with whole body, arm and leg BM (p<0.05) in women. In men, arm and pelvic BM were negatively associated with SB and whole body, pelvic and leg BM were positively associated with MVPA (p<0.05). In women, whole body and leg BM were positively associated with SB. Arm and whole body BM were positively associated and leg BM was negatively associated with LPA and arm BM was negatively associated with MVPA (p<0.05). Women without bone fractures spent less time in SB and more in LPA and MVPA than the subgroup with bone fractures.
Conclusion : We identified that the positive effect of MVPA relative to the other behaviors on bone mass is the strongest overall effect in men. Furthermore, women might decrease bone fracture risk through PA increase and SB reduction, despite the fact that no clear benefits of PA for bone mass were found
Signos neuromusculares anormales tras la anestesia con romifidina-propofol-halotano en dos algas
Dos galgas (ASA I, con edades de 1.5 y 8 años) incluídas en un estudio anestésico experimental, mostraron signos de una reacción neuromuscular epileptiforme con mioclonías, movimientos natatorios de las extremidades anteriores y opistótonos, durante el inicio de la recuperación anestésica en varios procedimientos anestésicos. Ninguna tenía antecedentes de epilepsia. Las dos fueron anestesiadas con los siguientes protocolos anestésicos: 1. Romifidina (ROM) Ilvl-Atropina (ATR)- Propofol (PRO)-Halotano (HAL), 2. ROM IV-ATRPRO-HAL. 3. Xilacina (XIL)-ATR-PRO-HAL, 4. Medetomidina (MED)-ATR-PRO-HAL y 5. ROMATR-Tiopental sódico (TIO)-HAL. Las perras no fueron sometidas a ninguna intervención quirúrgica. La anestesia se mantuvo durante 60 minutos en todos los casos. Las variables anestésicas y los parámetros sanguíneos estudiados se mantuvieron dentro de los rangos normales. La galga mayor mostró el cuadro descrito en los protocolos 1, 2 y 3 (más marcado en el 2), mientras que la más joven sólo los presentó en el 2, y con una menor intensidad en los signos clínicos. En todos los casos, éstos aparecieron de 2 a 5 minutos después de terminar la administración de halotano, y tras 15 minutos, y adoptar las pacientes el decúbito esternal, los signos cesaron. No fue necesario administrar ningún fármaco para aliviar el cuadro convulsivo. A partir de entonces, la recuperación fue normal y las pacientes no mostraron posteriormente síntomas nerviosos.Two female Greyhounds (ASA I, aged 1.5 and 8 years) showed signs of a neuromuscular epileptiforrn activity, with paddling, opisthotonus and shivering, during the anaesthetic recovery in some anaesthetic protocols. No epilepsy history was registered befare in any patient. The dogs were anaesthetized with the following procedures: 1. Romifidine (ROM) IMAtropine (ATR)-Propofol (PRO)-Halothane (HAL), 2. ROM IV-ATR-PRO-HAL. 3. Xylazine (XIL)-ATR-PROHAL, 4. Medetomidine (MED)-ATR-PRO-HAL y 5. ROM-ATR-Thiopentone (TIO)-HAL. The older Greyhound showed an epileptiforrn activity in the protocols 1, 2 and 3 (more intense in 2), however the younger one only exhibited these signs in the protocol 2. The older one suffered excitatory phenomena deeper than the other one. In all cases, signs began 2-5 minutes after the end of the halothane administration, and after 15 minutes, when the patients adopted the sternal recumbency the signs disappeared. Anaesthetic variables and haematological values were within normal limits. No drug was administered for treating the excitatory phenomena. The recovery was normal and the dogs did not exhibite nervous signs later
Entangled microwaves as a resource for entangling spatially separate solid-state qubits: Superconducting qubits, nitrogen-vacancy centers, and magnetic molecules
13 págs.; 10 figs.; 2 apps.Quantum correlations present in a broadband two-line squeezed microwave state can induce entanglement in a spatially separated bipartite system consisting of either two single qubits or two-qubit ensembles. By using an appropriate master equation for a bipartite quantum system in contact with two separate but entangled baths, the generating entanglement process in spatially separated quantum systems is thoroughly characterized. Decoherence thermal effects on the entanglement transfer are also discussed. Our results provide evidence that this entanglement transfer by dissipation is feasible, yielding to a steady-state amount of entanglement in the bipartite quantum system which can be optimized for a wide range of realistic physical systems that include state-of-the-art experiments with nitrogen-vacancy centers in diamond, superconducting qubits, or even magnetic molecules embedded in a crystalline matrix. ©2016 American Physical SocietyA.V.G., F.J.R., and L.Q. acknowledge financial support
from Facultad de Ciencias at UniAndes-2015 Project “Transfer
of Correlations from Non-classically Correlated Reservoirs
to Solid State Systems” and Project “Quantum Control of
Non-equilibrium Hybrid Systems-Part II,” UniAndes-2015.
J.J.G.R. acknowledges support from Spanish Mineco Project
No. FIS2012-33022, from EU FP7 Project PROMISCE, from
CAM Research Network QUITEMAD+.Peer Reviewe
Dredging impact on the benthic community of an unaltered inlet in southern Spain
The impact of dredging on macrobenthic
communities was studied in an unaltered zone, the
Getares inlet of Algeciras Bay (SW Spain). The data
obtained before, during and after dredging in a time series
spanning 5 years revealed the re-establishment of directly
affected communities and of physicochemical substrate
characteristics within 1 month of the end of dredging,
although 2 years later there was a confusing biological
impoverishment of the whole inlet. After 4 years, there
was a high degree of population re-establishment, both on
the bottoms directly affected by the works and on
neighbouring areas, that was partly due to the hydrodynamic conditions. Before this type of activity is undertaken, each case should be studied regarding viability, the
environmental medium where it will take place, the best
time of year, and the type of dredging to be used
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