6,447 research outputs found
On the origin of exponential growth in induced earthquakes in Groningen
The Groningen gas field shows exponential growth in earthquakes event counts
around a magnitude M1 with a doubling time of 6-9 years since 2001. This
behavior is identified with dimensionless curvature in land subsidence, which
has been evolving at a constant rate over the last few decades {essentially
uncorrelated to gas production.} We demonstrate our mechanism by a tabletop
crack formation experiment. The observed skewed distribution of event
magnitudes is matched by that of maxima of event clusters with a normal
distribution. It predicts about one event \,M5 per day in 2025, pointing to
increasing stress to human living conditions.Comment: 12 pages, 7 figures, to appear in Earthquakes and Structure
Reintroduction of an Undescribed Species of Elassoma into Pryor Branch, Limestone County, Alabama
Evidence for the importance of resonance scattering in X-ray emission line profiles of the O star Puppis
We fit the Doppler profiles of the He-like triplet complexes of \ion{O}{7}
and \ion{N}{6} in the X-ray spectrum of the O star Puppis, using
XMM-Newton RGS data collected over ks of exposure. We find that they
cannot be well fit if the resonance and intercombination lines are constrained
to have the same profile shape. However, a significantly better fit is achieved
with a model incorporating the effects of resonance scattering, which causes
the resonance line to become more symmetric than the intercombination line for
a given characteristic continuum optical depth . We discuss the
plausibility of this hypothesis, as well as its significance for our
understanding of Doppler profiles of X-ray emission lines in O stars.Comment: 29 pages, 8 figures, revised version accepted by Ap
Super-diversity. A new perspective on integration.
__Abstract__
Inhabitants of Dutch descent are no longer a majority in Amsterdam. Professor Maurice Crul addresses the superdivers city in his inaugural lecture. For the first time the people in Amsterdam from Dutch origin are a minority. This brings on the question who should adapt to who? Super-diversity draws a new perspective in the debate on integration. It argues that we are standing at a crossroads. On the one hand the multi-ethnic city is a fact: for the first time the people from Dutch origin are a minority in Amsterdam, just like all the other ethnic groups. On the other hand the idea of the multicultural society is increasingly viewed as naive, since cultural equality opens the door for undesirable cultural habits, like the repression of women. Super-diversity offers a progressive alternative for the failed idea of multiculturalism and the worn-out call from politicians for migrants to adapt to Dutch values. In his view, the key to a successfully diverse society lies in the emancipation of second generation women. Super-diversity carries out a vision of hope. But there is also urgency to it. It shows that an un-emancipated second generation withdraws from society, and is even more conservative than their parents
mockrobiota: a Public Resource for Microbiome Bioinformatics Benchmarking.
Mock communities are an important tool for validating, optimizing, and comparing bioinformatics methods for microbial community analysis. We present mockrobiota, a public resource for sharing, validating, and documenting mock community data resources, available at http://caporaso-lab.github.io/mockrobiota/. The materials contained in mockrobiota include data set and sample metadata, expected composition data (taxonomy or gene annotations or reference sequences for mock community members), and links to raw data (e.g., raw sequence data) for each mock community data set. mockrobiota does not supply physical sample materials directly, but the data set metadata included for each mock community indicate whether physical sample materials are available. At the time of this writing, mockrobiota contains 11 mock community data sets with known species compositions, including bacterial, archaeal, and eukaryotic mock communities, analyzed by high-throughput marker gene sequencing. IMPORTANCE The availability of standard and public mock community data will facilitate ongoing method optimizations, comparisons across studies that share source data, and greater transparency and access and eliminate redundancy. These are also valuable resources for bioinformatics teaching and training. This dynamic resource is intended to expand and evolve to meet the changing needs of the omics community
Spin-dependent tunneling through high-k LaAlO3
We report on the use of the LaAlO3 (LAO) high-k dielectric as a tunnel
barrier in magnetic tunnel junctions. From tunnel magnetoresistance (TMR)
measurements on epitaxial La2/3Sr1/3MnO3/LAO/La2/3Sr1/3MnO3 junctions, we
estimate a spin polarization of 77% at low temperature for the
La2/3Sr1/3MnO3/LAO interface. Remarkably, the TMR of La2/3Sr1/3MnO3/LAO/Co
junctions at low bias is negative, evidencing a negative spin polarization of
Co at the interface with LAO, and its bias dependence is very similar to that
of La2/3Sr1/3MnO3/STO/Co junctions. We discuss possible reasons for this
behaviour.Comment: 14 pages, 3 figure
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