1,207 research outputs found
Improving the quality of care in children with juvenile idiopathic arthritis: A step in the right direction
Efficient oxide phosphors for light upconversion; green emission from Yb3+ and Ho3+ co-doped Ln(2)BaZnO(5) (Ln = Y, Gd)
This is the author's accepted version of the article. The final published article can be found here: http://dx.doi.org/10.1039/C0JM01652
Noncommutative Geometry Framework and The Feynman's Proof of Maxwell Equations
The main focus of the present work is to study the Feynman's proof of the
Maxwell equations using the NC geometry framework. To accomplish this task, we
consider two kinds of noncommutativity formulations going along the same lines
as Feynman's approach. This allows us to go beyond the standard case and
discover non-trivial results. In fact, while the first formulation gives rise
to the static Maxwell equations, the second formulation is based on the
following assumption
The results extracted from the second formulation are more significant since
they are associated to a non trivial -extension of the Bianchi-set of
Maxwell equations. We find and where
, , and are local functions depending on
the NC -parameter. The novelty of this proof in the NC space is
revealed notably at the level of the corrections brought to the previous
Maxwell equations. These corrections correspond essentially to the possibility
of existence of magnetic charges sources that we can associate to the magnetic
monopole since is not vanishing in general.Comment: LaTeX file, 16 page
Choosy Grazers and Plant Communities – Interactions between Cattle Breeds and Vegetation in Semi-Natural Pastures
It is well recognized that domesticated and wild ruminant grazers have an important impact on the composition of grassland vegetation, mainly by forage selection, trampling and defaecation. However, little is known on the effects of genetic diversity, for example differences among breeds of cattle. Cattle breeds differ in terms of robustness, growth rate, weight and probably also in movement and forage selection behaviour, which all could impact vegetation composition. Our study therefore aimed at identifying breed-specific differences in forage selection and behaviour and its consequences for vegetation. In a controlled experiment on semi-natural pastures in the Swiss Alps, suckler cows of three cattle breeds (high-yielding Angus×Holstein crossbreeds, dual-purpose Original Braunvieh and slow-growing Highland cattle) grazed a series of adjacent paddocks. Plant species selection of the cattle was quantified by assessing biomass proportions of all plant species in vegetation subplots before and after pasturing. Movement behaviour was monitored using GPS sensors and pedometers. To assess long-term effects of cattle breeds on vegetation, we recorded vegetation composition in 50 paired pastures in mountain areas of Switzerland and in southern Germany, which were either grazed by Highland cattle or a production-oriented cattle breed. Low-productive Highland cattle selected plant species less strictly than the two higher-yielding breeds. They also exerted less physical pressure on the vegetation, because they were substantially lighter, but had relatively large claws. Highland cattle moved less actively, likely because of less selective foraging. These differences showed a strong correlation with differences in pasture vegetation, namely a smaller number of indicator plants for grazing and trampling tolerance on pastures of Highland cattle. Moreover, plant species richness was significantly increased by pasturing with Highland cattle, suggesting a high potential of robust breeds for sustaining or even increasing the diversity of species-rich pastures
A G_2 Unification of the Deformed and Resolved Conifolds
We find general first-order equations for G_2 metrics of cohomogeneity one
with S^3\times S^3 principal orbits. These reduce in two special cases to
previously-known systems of first-order equations that describe regular
asymptotically locally conical (ALC) metrics \bB_7 and \bD_7, which have
weak-coupling limits that are S^1 times the deformed conifold and the resolved
conifold respectively. Our more general first-order equations provide a
supersymmetric unification of the two Calabi-Yau manifolds, since the metrics
\bB_7 and \bD_7 arise as solutions of the {\it same} system of first-order
equations, with different values of certain integration constants.
Additionally, we find a new class of ALC G_2 solutions to these first-order
equations, which we denote by \wtd\bC_7, whose topology is an \R^2 bundle over
T^{1,1}. There are two non-trivial parameters characterising the homogeneous
squashing of the T^{1,1} bolt. Like the previous examples of the \bB_7 and
\bD_7 ALC metrics, here too there is a U(1) isometry for which the circle has
everywhere finite and non-zero length. The weak-coupling limit of the \wtd\bC_7
metrics gives S^1 times a family of Calabi-Yau metrics on a complex line bundle
over S^2\times S^2, with an adjustable parameter characterising the relative
sizes of the two S^2 factors.Comment: Latex, 14 pages, Major simplification of first-order equations;
references amende
Isospectrality in Chaotic Billiards
We consider a modification of isospectral cavities whereby the classical
dynamics changes from pseudointegrable to chaotic. We construct an example
where we can prove that isospectrality is retained. We then demonstrate this
explicitly in microwave resonators.Comment: 5 pages, 7 figure
The persistence of a chlorophyll spectral biosignature from Martian evaporite and spring analogues under Mars-like conditions
Spring and evaporite deposits are considered two of the most promising environments for past habitability on Mars and preservation of biosignatures. Manitoba, Canada hosts the East German Creek (EGC) hypersaline spring complex, and the post impact evaporite gypsum beds of the Lake St. Martin (LSM) impact. The EGC complex has microbial mats, sediments, algae and biofabrics, while endolithic communities are ubiquitous in the LSM gypsum beds. These communities are spectrally detectable based largely on the presence of a chlorophyll absorption band at 670 nm; however, the robustness of this feature under Martian surface conditions was unclear. Biological and biology-bearing samples from EGC and LSM were exposed to conditions similar to the surface of present day Mars (high UV flux, 100 mbar, anoxic, CO_2 rich) for up to 44 days, and preservation of the 670 nm chlorophyll feature and chlorophyll red-edge was observed. A decrease in band depth of the 670 nm band ranging from ∼16 to 80% resulted, with correlations seen in the degree of preservation and the spatial proximity of samples to the spring mound and mineral shielding effects. The spectra were deconvolved to Mars Exploration Rover (MER) Pancam and Mars Science Laboratory (MSL) Mastcam science filter bandpasses to investigate the detectability of the 670 nm feature and to compare with common mineral features. The red-edge and 670 nm feature associated with chlorophyll can be distinguished from the spectra of minerals with features below ∼1000 nm, such as hematite and jarosite. However, distinguishing goethite from samples with the chlorophyll feature is more problematic, and quantitative interpretation using band depth data makes little distinction between iron oxyhydroxides and the 670 nm chlorophyll feature. The chlorophyll spectral feature is observable in both Pancam and Mastcam, and we propose that of the proposed EXOMARS Pancam filters, the PHYLL filter is best suited for its detection
Instability of misoprostol tablets stored outside the blister: a potential serious concern for clinical outcome in medical abortion
Misoprostol (Cytotec) is recognised to be effective for many gynaecological indications including termination of pregnancy, management of miscarriage and postpartum haemorrhage. Although not licensed for such indications, it has been used for these purposes by millions of women throughout the world. Misoprostol tablets are most often packaged as multiple tablets within an aluminium strip, each within an individual alveolus. When an alveolus is opened, tablets will be exposed to atmospheric conditions
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