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Controlling antiferromagnetic domains in patterned La0.7Sr0.3FeO3 thin films
Transition metal oxide thin films and heterostructures are promising platforms to achieve full control of the antiferromagnetic (AFM) domain structure in patterned features as needed for AFM spintronic devices. In this work, soft x-ray photoemission electron microscopy was utilized to image AFM domains in micromagnets patterned into La0.7Sr0.3FeO3 (LSFO) thin films and La0.7Sr0.3MnO3 (LSMO)/LSFO superlattices. A delicate balance exists between magnetocrystalline anisotropy, shape anisotropy, and exchange interactions such that the AFM domain structure can be controlled using parameters such as LSFO and LSMO layer thickness, micromagnet shape, and temperature. In LSFO thin films, shape anisotropy gains importance only in micromagnets where at least one extended edge is aligned parallel to an AFM easy axis. In contrast, in the limit of ultrathin LSFO layers in the LSMO/LSFO superlattice, shape anisotropy effects dominate such that the AFM spin axes at micromagnet edges can be aligned along any in-plane crystallographic direction
Dynamics of Jupiter Trojans during the 2:1 mean motion resonance crossing of Jupiter and Saturn
We study the dynamics of Jupiter Trojans in the early phase of the Solar
system while the outer planets migrated due to their interaction with the
planetesimal disk.Comment: 10 pages, 17 figure
Cdx4 Dysregulates Hox Gene Expression and Generates Acute Myeloid Leukemia Alone and in Cooperation with Meis1a in a Murine Model
HOX genes have emerged as critical effectors of leukemogenesis, but the mechanisms that regulate their expression in leukemia are not well understood. Recent data suggest that the caudal homeobox transcription factors CDX1, CDX2, and CDX4, developmental regulators of HOX gene expression, may contribute to HOX gene dysregulation in leukemia. We report here that CDX4 is expressed normally in early hematopoietic progenitors and is expressed aberrantly in approximately 25% of acute myeloid leukemia (AML) patient samples. Cdx4 regulates Hox gene expression in the adult murine hematopoietic system and dysregulates Hox genes that are implicated in leukemogenesis. Furthermore, bone marrow progenitors that are retrovirally engineered to express Cdx4 serially replate in methylcellulose cultures, grow in liquid culture, and generate a partially penetrant, long-latency AML in bone marrow transplant recipients. Coexpression of the Hox cofactor Meis1a accelerates the Cdx4 AML phenotype and renders it fully penetrant. Structure-function analysis demonstrates that leukemic transformation requires intact Cdx4 transactivation and DNA-binding domains but not the putative Pbx cofactor interaction motif. Together, these data indicate that Cdx4 regulates Hox gene expression in adult hematopoiesis and may serve as an upstream regulator of Hox gene expression in the induction of acute leukemia. Inasmuch as many human leukemias show dysregulated expression of a spectrum of HOX family members, these collective findings also suggest a central role for CDX4 expression in the genesis of acute leukemia
A computer vision model for visual-object-based attention and eye movements
This is the post-print version of the final paper published in Computer Vision and Image Understanding. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2008 Elsevier B.V.This paper presents a new computational framework for modelling visual-object-based attention and attention-driven eye movements within an integrated system in a biologically inspired approach. Attention operates at multiple levels of visual selection by space, feature, object and group depending on the nature of targets and visual tasks. Attentional shifts and gaze shifts are constructed upon their common process circuits and control mechanisms but also separated from their different function roles, working together to fulfil flexible visual selection tasks in complicated visual environments. The framework integrates the important aspects of human visual attention and eye movements resulting in sophisticated performance in complicated natural scenes. The proposed approach aims at exploring a useful visual selection system for computer vision, especially for usage in cluttered natural visual environments.National Natural Science of Founda-
tion of Chin
Learning-based adaption of robotic friction models
In the Fourth Industrial Revolution, wherein artificial intelligence and the
automation of machines occupy a central role, the deployment of robots is
indispensable. However, the manufacturing process using robots, especially in
collaboration with humans, is highly intricate. In particular, modeling the
friction torque in robotic joints is a longstanding problem due to the lack of
a good mathematical description. This motivates the usage of data-driven
methods in recent works. However, model-based and data-driven models often
exhibit limitations in their ability to generalize beyond the specific dynamics
they were trained on, as we demonstrate in this paper. To address this
challenge, we introduce a novel approach based on residual learning, which aims
to adapt an existing friction model to new dynamics using as little data as
possible. We validate our approach by training a base neural network on a
symmetric friction data set to learn an accurate relation between the velocity
and the friction torque. Subsequently, to adapt to more complex asymmetric
settings, we train a second network on a small dataset, focusing on predicting
the residual of the initial network's output. By combining the output of both
networks in a suitable manner, our proposed estimator outperforms the
conventional model-based approach and the base neural network significantly.
Furthermore, we evaluate our method on trajectories involving external loads
and still observe a substantial improvement, approximately 60-70\%, over the
conventional approach. Our method does not rely on data with external load
during training, eliminating the need for external torque sensors. This
demonstrates the generalization capability of our approach, even with a small
amount of data-only 43 seconds of a robot movement-enabling adaptation to
diverse scenarios based on prior knowledge about friction in different
settings
Electronic information sharing in local government authorities: Factors influencing the decision-making process
This is the post-print version of the final paper published in International Journal of Information Management. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2013 Elsevier B.V.Local Government Authorities (LGAs) are mainly characterised as information-intensive organisations. To satisfy their information requirements, effective information sharing within and among LGAs is necessary. Nevertheless, the dilemma of Inter-Organisational Information Sharing (IOIS) has been regarded as an inevitable issue for the public sector. Despite a decade of active research and practice, the field lacks a comprehensive framework to examine the factors influencing Electronic Information Sharing (EIS) among LGAs. The research presented in this paper contributes towards resolving this problem by developing a conceptual framework of factors influencing EIS in Government-to-Government (G2G) collaboration. By presenting this model, we attempt to clarify that EIS in LGAs is affected by a combination of environmental, organisational, business process, and technological factors and that it should not be scrutinised merely from a technical perspective. To validate the conceptual rationale, multiple case study based research strategy was selected. From an analysis of the empirical data from two case organisations, this paper exemplifies the importance (i.e. prioritisation) of these factors in influencing EIS by utilising the Analytical Hierarchy Process (AHP) technique. The intent herein is to offer LGA decision-makers with a systematic decision-making process in realising the importance (i.e. from most important to least important) of EIS influential factors. This systematic process will also assist LGA decision-makers in better interpreting EIS and its underlying problems. The research reported herein should be of interest to both academics and practitioners who are involved in IOIS, in general, and collaborative e-Government, in particular
Narrowly distributed crystal orientation in biomineral vaterite
Biominerals formed by animals provide skeletal support, and many other
functions. They were previously shown to grow by aggregation of amorphous
nanoparticles, but never to grow ion-by-ion from solution, which is a common
growth mechanism for abiotic crystals. We analyze vaterite CaCO3 multi
crystalline spicules from the solitary tunicate Herdmania momus, with
Polarization dependent Imaging Contrast PIC mapping, scanning and aberration
corrected transmission electron microscopies. The first fully quantitative PIC
mapping data, presented here, measured 0{\deg} 30{\deg} angle spreads between
immediately adjacent crystals. Such narrowly distributed crystal orientations
demonstrate that crystallinity does not propagate from one crystal to another
0{\deg} angle spreads, nor that new crystals with random orientation 90{\deg}
nucleate. There are no organic layers at the interface between crystals, hence
a new, unknown growth mechanism must be invoked, with crystal nucleation
constrained within 30{\deg}. Two observations are consistent with crystal
growth from solution: vaterite microcrystals express crystal faces, and are
smooth at the nanoscale after cryo fracture. The observation of 30{\deg} angle
spreads, lack of interfacial organic layers, and smooth fracture figures
broadens the range of known biomineralization mechanisms and may inspire novel
synthetic crystal growth strategies. Spherulitic growth from solution is one
possible mechanism consistent with all these observations.Comment: Chemistry of Materials 201
Ligand-Free Copper-Catalyzed Cyano- and Alkynylstannylation of Arynes
A carbon–carbon triple bond of arynes was found to undergo cyanostannylation with a tin cyanide under CuCN catalysis to afford diverse ortho-cyanoarylstannanes in high yield. The copper catalyst was also effective for alkynylstannylation of arynes, and the resulting alkynylstannylated products were demonstrated to be convertible into biologically active compounds and a dye for dyesensitized solar cell.This work was financially supported by JSPS KAKENHI Grant Number JP16H01031 in Precisely Designed Catalysts with Customized Scaffolding and by ACT-C, JST
Detection and Characterization of Planets in Binary and Multiple Systems
Moderately close binaries are a special class of targets for planet searches.
From a theoretical standpoint, their hospitality to giant planets is
uncertain and debated. From an observational standpoint, many of these systems
present technical difficulties for precise radial-velocity measurements and
classical Doppler surveys avoid them accordingly. In spite of these adverse
factors, present data support the idea that giant planets residing in binary
and hierarchical systems provide unique observational constraints on the
processes of planet formation and evolution. The interest and the importance of
including various types of binary stars in extrasolar planet studies have thus
grown over time and significant efforts have recently been put into: (i)
searching for stellar companions to the known planet-host stars using direct
imaging, and (ii) extending Doppler planet searches to spectroscopic and
moderately close visual binaries. In this contribution we review the
observational progresses made over the past years to detect and study
extrasolar planets in binary systems, putting special emphasis on the two
developments mentioned above.Comment: 20 pages, 4 figures, review to appear in Extrasolar Planets in
Multi-Body Systems: Theory and Observations, ed. K. Gozdziewski, A.
Niedzielski, and J. Schneider, EAS Publications Serie
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