1,194 research outputs found
The Arabidopsis thaliana SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASES1 and 2 control male sporogenesis
The Arabidopsis thaliana SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) family of plasma membrane receptors consists of five closely related members. The SERK1 and SERK2 genes show a complex expression pattern throughout development. Both are expressed in anther primordia up to the second parietal division. After this point, expression ceases in the sporocytes and is continued in the tapetum and middle layer precursors. Single knockout mutants of SERK1 and SERK2 show no obvious phenotypes. Double mutants of SERK1 and SERK2 are completely male sterile due to a failure in tapetum specification. Fertility can be restored by a single copy of either gene. The SERK1 and SERK2 proteins can form homodimers or heterodimers in vivo, suggesting they are interchangeable in the SERK1/SERK2 signaling comple
Two-axis magnetic field sensor
A ferromagnetic thin-film based magnetic field sensor with first and second sensitive direction sensing structures each having a nonmagnetic intermediate layer with two major surfaces on opposite sides thereof having a magnetization reference layer on one and an anisotropic ferromagnetic material sensing layer on the other having a length in a selected length direction and a smaller width perpendicular thereto and parallel to the relatively fixed magnetization direction. The relatively fixed magnetization direction of said magnetization reference layer in each is oriented in substantially parallel to the substrate but substantially perpendicular to that of the other. An annealing process is used to form the desired magnetization directions
Learning Colour Representations of Search Queries
Image search engines rely on appropriately designed ranking features that
capture various aspects of the content semantics as well as the historic
popularity. In this work, we consider the role of colour in this relevance
matching process. Our work is motivated by the observation that a significant
fraction of user queries have an inherent colour associated with them. While
some queries contain explicit colour mentions (such as 'black car' and 'yellow
daisies'), other queries have implicit notions of colour (such as 'sky' and
'grass'). Furthermore, grounding queries in colour is not a mapping to a single
colour, but a distribution in colour space. For instance, a search for 'trees'
tends to have a bimodal distribution around the colours green and brown. We
leverage historical clickthrough data to produce a colour representation for
search queries and propose a recurrent neural network architecture to encode
unseen queries into colour space. We also show how this embedding can be learnt
alongside a cross-modal relevance ranker from impression logs where a subset of
the result images were clicked. We demonstrate that the use of a query-image
colour distance feature leads to an improvement in the ranker performance as
measured by users' preferences of clicked versus skipped images.Comment: Accepted as a full paper at SIGIR 202
Shear-thinning, Coulomb friction and grain collisions in debris-flow waterfalls: Applications of a 3D phase mixture model with a single calibration parameter and a complex 4-way coupled resolved CFD-DEM approach
Shear-thinning is a common flow-feature of fine sediment suspensions. Mixed with gravel, Coulomb friction drives the energy dissipation between small grains while collisions become more and more important with larger grains. The interaction of the flow with local geometries of the channel can enforce each of these three key features, making the design analysis of channel sections with obstacles a highly back-coupled system. This paper addresses the numerical simulation of debris flow material under extreme flow conditions at planned protection measures. Mixtures with small grain sizes are modelled with a single calibration parameter using the 3D CFD phase mixture software debrisInterMixing and compared with laboratory experiments. To further investigate the scaling of the results, a coupled code of YADE and debrisInterMixingLP is applied accounting for the 4-way coupling to the coarse boulders at the front with resolved CFD-DEM, reaching beyond the possibilities of debris flow experiments
Concert recording 2017-11-30b
[Track 1]. Sonata for clarinet and piano. I. Mässig bewegt / Paul Hindemith -- [Track 2]. Concertino in E♭ major, op. 26 / Carl Maria von Weber -- [Track 3]. Five bagatelles for clarinet and piano, op. 23. I. Prelude / Gerald Finzi -- [Track 4]. Solo de concours, op. 10 / Henri Rabaud -- [Track 5]. Concerto no. 2 in E♭ major, op. 74. III. Alla polacca / Weber -- [Track 6]. Six studies in English folk song. II. Andante sostenuto (\u27Spurn point\u27) [Track 7]. III. Larghetto ( Van Dieman\u27s land\u27) in D modal minor [Track 8]. IV. Lento (\u27She borrowed some of her mother\u27s gold\u27) in D major / Ralph Vaughan Williams -- [Track 9]. Concerto no. 2 in F minor, op. 5. III. Rondo: allegretto / Bernard Crusell -- [Track 10]. Premiere rhapsodie / Claude Debussy -- [Track 11]. Fantasy for clarinet and piano / Carl Nielsen
DIX Domain Polymerization Drives Assembly of Plant Cell Polarity Complexes
The identities of cell polarity determinants are not conserved between animals and plants; however, characterization of a DIX-domain containing protein in land plants reveals that the physical principles of polar complex assembly are preserved across eukaryotes.</p
The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared
Quasars are thought to be powered by supermassive black holes accreting
surrounding gas. Central to this picture is a putative accretion disk which is
believed to be the source of the majority of the radiative output. It is well
known, however, that the most extensively studied disk model -- an optically
thick disk which is heated locally by the dissipation of gravitational binding
energy -- is apparently contradicted by observations in a few major respects.
In particular, the model predicts a specific blue spectral shape asymptotically
from the visible to the near-infrared, but this is not generally seen in the
visible wavelength region where the disk spectrum is observable. A crucial
difficulty was that, toward the infrared, the disk spectrum starts to be hidden
under strong hot dust emission from much larger but hitherto unresolved scales,
and thus has essentially been impossible to observe. Here we report
observations of polarized light interior to the dust-emiting region that enable
us to uncover this near-infrared disk spectrum in several quasars. The revealed
spectra show that the near-infrared disk spectrum is indeed as blue as
predicted. This indicates that, at least for the outer near-infrared-emitting
radii, the standard picture of the locally heated disk is approximately
correct. The model problems at shorter wavelengths should then be directed
toward a better understanding of the inner parts of the revealed disk. The
newly uncovered disk emission at large radii, with more future measurements,
will also shed totally new light on the unanswered critical question of how and
where the disk ends.Comment: published in Nature, 24 July 2008 issue. Supplementary Information
can be found at
http://www.mpifr-bonn.mpg.de/div/ir-interferometry/suppl_info.pdf Published
version can be accessed from
http://www.nature.com/nature/journal/v454/n7203/pdf/nature07114.pd
AGN accretion disks as spatially resolved by polarimetry
A crucial difficulty in understanding the nature of the putative accretion
disk in AGNs is that some of its key intrinsic spectral signatures cannot be
observed directly. The strong emissions from the broad-line region (BLR) and
the obscuring torus, which are generally yet to be spatially resolved,
essentially 'bury' such signatures. Here we argue that we can actually isolate
the disk emission spectrum by using optical and near-infrared polarization of
quasars and uncover the important spectral signatures. In these quasars, the
polarization is considered to originate from electron scattering interior to
the BLR, so that the polarized flux shows the disk spectrum with all the
emissions from the BLR and torus eliminated. The polarized flux observations
have now revealed a Balmer edge feature in absorption and a blue near-infrared
spectral shape consistent with a specific and robust theoretical prediction.
These results critically verify the long-standing picture of an optically thick
and locally heated disk in AGNs.Comment: Proceedings for "The Universe under the Microscope" (AHAR 2008), held
in Bad Honnef (Germany) in April 2008, to be published in Journal of Physics:
Conference Series by Institute of Physics Publishing, R. Schoedel, A. Eckart,
S. Pfalzner, and E. Ros (eds.
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