893 research outputs found
Comparación de las técnicas de diagnóstico por imagen empleadas en la articulación con osteoartritis y su interpretación
El diagnóstico por imagen es esencial para clasificar la gravedad de la osteoartritis y evaluar la eficacia del tratamiento. La técnica ideal de diagnóstico por imagen debe detectar cambios en el cartÃlago articular. Algunas técnicas diagnósticas son la radiografÃa, la tomografÃa computerizada, la resonancia magnética y la artroscopia.
A Review on Internet of Things Solutions for Intelligent Energy Control in Buildings for Smart City Applications
© 2017 The Authors. A smart city exploits sustainable information and communication technologies to improve the quality and the performance of urban services for citizens and government, while reducing resources consumption. Intelligent energy control in buildings is an important aspect in this. The Internet of Things can provide a solution. It aims to connect numerous heterogeneous devices through the internet, for which it needs a flexible layered architecture where the things, the people and the cloud services are combined to facilitate an application task. Such flexible IoT hierarchical architecture model will be introduced in this paper with an overview of each key component for intelligent energy control in buildings for smart cities
Subchondral bone density distribution of the talus in clinically normal Labrador Retrievers
Background: Bones continually adapt their morphology to their load bearing function. At the level of the subchondral bone, the density distribution is highly correlated with the loading distribution of the joint. Therefore, subchondral bone density distribution can be used to study joint biomechanics non-invasively. In addition physiological and pathological joint loading is an important aspect of orthopaedic disease, and research focusing on joint biomechanics will benefit veterinary orthopaedics. This study was conducted to evaluate density distribution in the subchondral bone of the canine talus, as a parameter reflecting the long-term joint loading in the tarsocrural joint.
Results: Two main density maxima were found, one proximally on the medial trochlear ridge and one distally on the lateral trochlear ridge. All joints showed very similar density distribution patterns and no significant differences were found in the localisation of the density maxima between left and right limbs and between dogs.
Conclusions: Based on the density distribution the lateral trochlear ridge is most likely subjected to highest loads within the tarsocrural joint. The joint loading distribution is very similar between dogs of the same breed. In addition, the joint loading distribution supports previous suggestions of the important role of biomechanics in the development of OC lesions in the tarsus. Important benefits of computed tomographic osteoabsorptiometry (CTOAM), i.e. the possibility of in vivo imaging and temporal evaluation, make this technique a valuable addition to the field of veterinary orthopaedic research
Needle age-related and seasonal photosynthetic capacity variation is negligible for modelling yearly gas exchange of a sparse temperate Scots pine forest
In this study, we quantified the predictive accuracy loss involved with
omitting photosynthetic capacity variation for a Scots pine (<i>Pinus sylvestris</i> L.) stand in
Flanders, Belgium. Over the course of one phenological year, we measured the
maximum carboxylation capacity at 25 °C (<i>V</i><sub>m25</sub>), the maximum electron
transport capacity at 25 °C (<i>J</i><sub>m25</sub>), and the leaf area index (LAI) of
different-aged needle cohorts in the upper and lower canopy. We used these
measurements as input for a process-based multi-layer canopy model with the
objective to quantify the difference in yearly gross ecosystem productivity
(GEP) and canopy transpiration (<i>E</i><sub>can</sub>) simulated under scenarios in which
the observed needle age-related and/or seasonal variation of <i>V</i><sub>m25</sub> and
<i>J</i><sub>m25</sub> was omitted. We compared simulated GEP with estimations obtained from
eddy covariance measurements. Additionally, we measured summer needle N
content to investigate the relationship between photosynthetic capacity
parameters and needle N content along different needle ages.
<br><br>
Results show that <i>V</i><sub>m25</sub> and <i>J</i><sub>m25</sub> were, respectively, 27% and
13% higher in current-year than in one-year old needles. A significant
seasonality effect was found on <i>V</i><sub>m25</sub>, but not on <i>J</i><sub>m25</sub>. Summer needle
N content was considerably lower in current-year than in one-year-old
needles. As a result, the correlations between <i>V</i><sub>m25</sub> and needle N content
and <i>J</i><sub>m25</sub> and needle N content were negative and non-significant,
respectively. Some explanations for these unexpected correlations were
brought forward. Yearly GEP was overestimated by the canopy model by ±15% under all scenarios. The inclusion and omission of the observed
needle age-related <i>V</i><sub>m25</sub> and <i>J</i><sub>m25</sub> variation in the model simulations
led to statistically significant but ecologically irrelevant differences in
simulated yearly GEP and <i>E</i><sub>can</sub>. Omitting seasonal variation did not yield
significant simulation differences. Our results indicate that intensive
photosynthetic capacity measurements over the full growing season and
separate simulation of needle age classes were no prerequisites for accurate
simulations of yearly canopy gas exchange. This is true, at least, for the
studied stand, which has a very sparse canopy and is exposed to high N
deposition and, hence, is not fully representative for temperate Scots pine
stands. Nevertheless, we believe well-parameterized process-based canopy
models – as applied in this study – are a useful tool to quantify losses of
predictive accuracy involved with canopy simplification in modelling
On the metallicity dependence of crystalline silicates in oxygen-rich asymptotic giant branch stars and red supergiants
We investigate the occurrence of crystalline silicates in oxygen-rich evolved
stars across a range of metallicities and mass-loss rates. It has been
suggested that the crystalline silicate feature strength increases with
increasing mass-loss rate, implying a correlation between lattice structure and
wind density. To test this, we analyse Spitzer IRS and Infrared Space
Observatory SWS spectra of 217 oxygen-rich asymptotic giant branch stars and 98
red supergiants in the Milky Way, the Large and Small Magellanic Clouds and
Galactic globular clusters. These encompass a range of spectral morphologies
from the spectrally-rich which exhibit a wealth of crystalline and amorphous
silicate features to 'naked' (dust-free) stars. We combine spectroscopic and
photometric observations with the GRAMS grid of radiative transfer models to
derive (dust) mass-loss rates and temperature. We then measure the strength of
the crystalline silicate bands at 23, 28 and 33 microns. We detect crystalline
silicates in stars with dust mass-loss rates which span over 3 dex, down to
rates of ~10^-9 solar masses/year. Detections of crystalline silicates are more
prevalent in higher mass-loss rate objects, though the highest mass-loss rate
objects do not show the 23-micron feature, possibly due to the low temperature
of the forsterite grains or it may indicate that the 23-micron band is going
into absorption due to high column density. Furthermore, we detect a change in
the crystalline silicate mineralogy with metallicity, with enstatite seen
increasingly at low metallicity.Comment: Accepted for publication in MNRAS, 24 pages, 16 figure
- …