2,001 research outputs found
Energy-Momentum Complex in M\o ller's Tetrad Theory of Gravitation
M\o ller's Tetrad Theory of Gravitation is examined with regard to the
energy-momentum complex. The energy-momentum complex as well as the
superpotential associated with M\o ller's theory are derived. M\o ller's field
equations are solved in the case of spherical symmetry. Two different
solutions, giving rise to the same metric, are obtained. The energy associated
with one solution is found to be twice the energy associated with the other.
Some suggestions to get out of this inconsistency are discussed at the end of
the paper.Comment: LaTeX2e with AMS-LaTeX 1.2, 13 page
An assessment of diet overlap of two mesocarnivores in the North-West Province, South Africa
We used scat analysis to study the diet of two sympatric medium-sized carnivores: brown hyaena and black-backed jackal, in the NorthWest Province of South Africa. Seven major dietary categories were identified from the scats, with mammal remains being most common for both species. Brown hyaena scats contained more large mammal remains, which together with the presence of invertebrates (in 50% of all brown hyaena scats), suggests that they mainly scavenged. Jackal scats contained a higher proportion of small mammal remains, suggesting that jackals actively hunted more often than brown hyaenas did. The diets differed significantly between the two species, even though diet overlap was fairly high (0.79). Further analysis, albeit based on small sample sizes, suggests that diet of these mesopredators differ between protected reserves with apex predators and unprotected areas without apex predators, thus confounding generalizations. Further studies are therefore required to investigate possible mesopredator release when apex predators are absent
Strategies for the early detec tion and management of chronic kidney disease– tertiary and primary health care working together
No Abstract
Aportació al coneixement de l"herbari Trèmols de l"Institut Botà nic de Barcelona.
The herbarium BC-Trèmols was created during the second half of the 19th century by the Catalan chemist and botanist Frederic Trèmols Borrell. Between 1930 and 1960, the technician Antoni Marcos carried out a thorough review. The current collection consists of approximately 9000 specimen sheets; is made up of 58 volumes reordered by Marcos,two volumes with the original structure, four boxes of Hieracium and 85 boxes with additional material. Up to now 22 volumes and four boxes of Hieracium have been computerized (3695 specimens); we made an inventory at genus level of all volumes, and we computerized the original catalogue of the herbarium and the existing taxonomical fiches. We have also developed a preliminary inventory of the contents of the extra boxes. The analysis of these 3695 herbarium specimens clearly shows that it mainly consists of samples obtained by exchange (67.1%) especially within the Société Helvétique pour l"Échange des Plantes and the Societat Botà nica Barcelonesa. Among the materials studied we found two specimens regarded as interesting from a taxonomical and/or nomenclatural point of view (isotypes of Silene holzmanii Heldr. ex Boiss. and of Arenaria minutiflora Loscos). Therefore, the main interest of the herbarium lies in the diversity of the geographical provenance of plants, which makes of this collection one of the first"pan-European herbaria" in Catalonia
Single-shot hybrid photoacoustic-fluorescent microendoscopy through a multimode fiber with wavefront shaping
We present a minimally-invasive endoscope based on a multimode fiber that combines photoacoustic and fluorescence sensing. From the measurement of a transmission matrix during a prior calibration step, a focused spot is produced and raster-scanned over a sample at the distal tip of the fiber by use of a fast spatial light modulator. An ultra-sensitive fiber-optic ultrasound sensor for photoacoustic detection placed next to the fiber is combined with a photodetector to obtain both fluorescence and photoacoustic images with a distal imaging tip no larger than 250 µm. The high signal-to-noise ratio provided by wavefront shaping based focusing and the ultra-sensitive ultrasound sensor enables imaging with a single laser shot per pixel, demonstrating fast two-dimensional hybrid in vitro imaging of red blood cells and fluorescent beads
Mean field theory and Monte Carlo simulation of Phase transitions and Magnetic Properties of a tridimensional Fe7S8 Compound
The structural, electronic and magnetic properties of Fe7S8 material have
been studied within the framework of the ab-initio calculations, the mean field
approximation (MFA) and Monte Carlo simulation (MCS). Our study shows that two
forms of the iron atoms, Fe2+ with spin S=2, and Fe3+ with spin {\sigma}=5/2
are the most probable configurations. A mixed Ising model with ferromagnetic
spin coupling between Fe2+ and Fe3+ ions and between Fe3+ and Fe3+ ions, and
with antiferromagnetic spin coupling between Fe2+ ions of adjacent layers has
been used to study the magnetic properties of this compound. We demonstrated
that the magnetic phase transition can be either of the first or of the second
order, depending on the value of the exchange interaction and crystal field.
The presence of vacancies in every second iron layer leads to incomplete
cancellation of magnetic moments, hence to the emergence of the ferrimagnetism.
Anomalies in the magnetization behavior have been found and compared with the
experimental results.Comment: 18 pages, 14 Figures, 4 Table
Correlation between microstructure and electric properties in SnO(2) rich enamels
No abstract availabl
Cost analysis of the management of brain metastases in patients with advanced ALK+ NSCLC: alectinib versus crizotinib
Aim: To estimate management cost of NSCLC ALK+ patients with and without brain metastasis (BM), and to compare annual costs in patients treated with alectinib or crizotinib. Methods: Management cost/year (euro 2018) in patients with and without BM was estimated with disaggregated resource consumption provided by local oncologists, including medical visits, hospitalizations, diagnostic/laboratory tests, imaging techniques and surgical procedures. The comparison of costs/year with alectinib and crizotinib, considered the cumulative 12-month incidence of BM in ALEX trial (9.4 and 41.4%, respectively). Results: Management cost was euro6173.42/patient-year without BM and euro21,637.50/patient-year with BM. With alectinib, average cost/patient was lower than crizotinib (euro4948.51/patient-year). Conclusion: Prevention of BM with alectinib may result in reductions of cost/year in the management of advanced ALK+ NSCLC
Inspiratory muscle warm-up does not improve cycling time-trial performance
Purpose: This study examined the effects of an active cycling warm-up, with and without the addition of an inspiratory muscle warm-up (IMW), on 10-km cycling time-trial performance
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