3,616 research outputs found
Dynamical mean-field approach to materials with strong electronic correlations
We review recent results on the properties of materials with correlated
electrons obtained within the LDA+DMFT approach, a combination of a
conventional band structure approach based on the local density approximation
(LDA) and the dynamical mean-field theory (DMFT). The application to four
outstanding problems in this field is discussed: (i) we compute the full
valence band structure of the charge-transfer insulator NiO by explicitly
including the p-d hybridization, (ii) we explain the origin for the
simultaneously occuring metal-insulator transition and collapse of the magnetic
moment in MnO and Fe2O3, (iii) we describe a novel GGA+DMFT scheme in terms of
plane-wave pseudopotentials which allows us to compute the orbital order and
cooperative Jahn-Teller distortion in KCuF3 and LaMnO3, and (iv) we provide a
general explanation for the appearance of kinks in the effective dispersion of
correlated electrons in systems with a pronounced three-peak spectral function
without having to resort to the coupling of electrons to bosonic excitations.
These results provide a considerable progress in the fully microscopic
investigations of correlated electron materials.Comment: 24 pages, 14 figures, final version, submitted to Eur. Phys. J. for
publication in the Special Topics volume "Cooperative Phenomena in Solids:
Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom
Design and development of a field-deployable single-molecule detector (SMD) for the analysis of molecular markers
Single-molecule detection (SMD) has demonstrated some attractive benefits for many types of biomolecular analyses including enhanced processing speed by eliminating processing steps, elimination of ensemble averaging and single-molecule sensitivity. However, it's wide spread use has been hampered by the complex instrumentation required for its implementation when using fluorescence as the readout modality. We report herein a simple and compact fluorescence single-molecule instrument that is straightforward to operate and consisted of fiber optics directly coupled to a microfluidic device. The integrated fiber optics served as waveguides to deliver the laser excitation light to the sample and collecting the resulting emission, simplifying the optical requirements associated with traditional SMD instruments by eliminating the need for optical alignment and simplification of the optical train. Additionally, the use of a vertical cavity surface emitting laser and a single photon avalanche diode serving as the excitation source and photon transducer, respectively, as well as a field programmable gate array (FPGA) integrated into the processing electronics assisted in reducing the instrument footprint. This small footprint SMD platform was tested using fluorescent microspheres and single AlexaFluor 660 molecules to determine the optimal operating parameters and system performance. As a demonstration of the utility of this instrument for biomolecular analyses, molecular beacons (MBs) were designed to probe bacterial cells for the gene encoding Gram-positive species. The ability to monitor biomarkers using this simple and portable instrument will have a number of important applications, such as strain-specific detection of pathogenic bacteria or the molecular diagnosis of diseases requiring rapid turn-around-times directly at the point-of-use.close5
Bio-orthogonal Fluorescent Labelling of Biopolymers through Inverse-Electron-Demand Diels–Alder Reactions
Bio-ort
hogona
llabellin
gschemes
based
on inverse-elec
tron-
deman
dDiels–Ald
er (IEDDA)
cycloa
ddition
have
attracted
much
attention
in chem
ical biology
recently
.The appeal
ing
features
of this reactio
n, such
as the fast reactio
nkinetics,
fully
bio-ort
hogonal
nature
and high
selectiv
ity,have helped
chem
i-
cal biologists
gain
deeper
understandi
ng of biochemic
al pro-
cesses
at the molecular
level.Listing
the compo
nents
and dis-
cussing
the possib
ilities
andlimitations
of thesereagent
s, we
provid
earecent
snapshot
of the field
of IEDDA
-based
biomo-
lecular
manipulatio
nwith special
focus
on fluores
cent
modula-
tion
approaches
throug
hthe use of bio-orthogon
alized
build-
ing blocks.
At the end,
we discuss
challenges
that
need
to be
addres
sed
for further
develop
ments
in order
to overcome
recent
limita
tions
and to enabl
eresearchers
to answer
biomo
-
lecular
quest
ions in more
detail
Authorship trends in software engineering
This paper aims to examine authorship trends in software engineering, especially those related to the number of authors, of scientific publications. We collected and mined around 70.000 entries from DBLP for 122 conferences and journals, for the period 1971–2012, in order to process several bibliometric indicators. We provide evidence that the number of authors of articles in software engineering is increasing on average around +0.40 authors/decade. The results also indicate that until 1980, the majority of the articles have a sole author, while nowadays articles with 3 or 4 authors represent almost half of the total.Fundação para a Ciência e a Tecnologia (FCT
Attachment and self-regulation in the workplace—a theoretical integration
Interest in adopting attachment theory to interpret workplace dynamics is growing, reflected in increasing theoretical development and empirical research. However, the advancement of the field has been hindered by the limited attention paid to the cognitive, affective and behavioral processes involved in carrying the effect of attachment styles on outcomes. Adopting a self-regulatory lens, this paper aims to unpack the attachment black box by integrating attachment theory and self-regulation theory. We propose a theoretical framework that explicates how attachment styles function to shape individuals’ regulatory responses from cognitive, affective, and behavioral perspectives, as well as identifying boundary conditions of the activation processes of attachment styles in the workplace. The framework provides novel insights into the effects, mechanisms, and boundary conditions of employee attachment styles in the workplace. Implications of the framework and future research directions are discussed
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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Design and closed‐loop motion planning of an untethered swimming soft robot using 2D discrete elastic rods simulations
Sequential roles for myosin-X in BMP6-dependent filopodial extension, migration, and activation of BMP receptors
Endothelial cell migration is an important step during angiogenesis, and its dysregulation contributes to aberrant neovascularization. The bone morphogenetic proteins (BMPs) are potent stimulators of cell migration and angiogenesis. Using microarray analyses, we find that myosin-X (Myo10) is a BMP target gene. In endothelial cells, BMP6-induced Myo10 localizes in filopodia, and BMP-dependent filopodial assembly decreases when Myo10 expression is reduced. Likewise, cellular alignment and directional migration induced by BMP6 are Myo10 dependent. Surprisingly, we find that Myo10 and BMP6 receptor ALK6 colocalize in a BMP6-dependent fashion. ALK6 translocates into filopodia after BMP6 stimulation, and both ALK6 and Myo10 possess intrafilopodial motility. Additionally, Myo10 is required for BMP6-dependent Smad activation, indicating that in addition to its function in filopodial assembly, Myo10 also participates in a requisite amplification loop for BMP signaling. Our data indicate that Myo10 is required to guide endothelial migration toward BMP6 gradients via the regulation of filopodial function and amplification of BMP signals
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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