468 research outputs found
Magnetization reversal in amorphous Fe/Dy multilayers: a Monte Carlo study
The Monte Carlo method in the canonical ensemble is used to investigate
magnetization reversal in amorphous transition metal - rare earth multilayers.
Our study is based on a model containing diluted clusters which exhibit an
effective uniaxial anisotropy in competition with random magnetic anisotropy in
the matrix. We simulate hysteresis loops for an abrupt profile and a diffuse
one obtained from atom probe tomography analyses. Our results evidence that the
atom probe tomography profile favors perpendicular magnetic anisotropy in
agreement with magnetic measurements. Moreover, the hysteresis loops calculated
at several temperatures qualitatively agree with the experimental ones
Examining high school studentsâ personality traits of extraversion and emotional stability in relation to their academic expectation and value appraisals
Abstract : Both personality and motivational characteristics can be considered to estimate individualsâ potential for adjustment and development. That said, these characteristics are rarely studied in conjunction. In this study, we examine how personality and motivational characteristics relate one to the other and influence how students approach learning. More precisely, we analyzed the additive and interactive effects of two intimately related traits (extraversion and emotional stability) from the Big Five model of personality on five motivational dimensions reflecting academic expectations (sense of competence) and values (interest, utility, and mastery and performance goal orientations). Data was collected from a sample of 303 students in tenth and eleventh grade (108 boys and 195 girls; Mage = 16.275 years, SD = 1.149) in a French-Canadian public high school in the greater Quebec City area. Primary analyses included both bivariate correlation and hierarchical regression analyses. Correlations indicated that emotionally stable students were more interested in learning. Hierarchical regression showed that emotionally stable students were more likely to exhibit a performance goal orientation, especially when they were extroverted. These analyses also revealed that emotionally stable students were more interested in learning, especially when they had a strong sense of competence. Results are discussed in light of the limited but relevant existing literature
Evidence that pairing with genetically similar mates is maladaptive in a monogamous bird
<p>Abstract</p> <p>Background</p> <p>Evidence of multiple genetic criteria of mate choice is accumulating in numerous taxa. In many species, females have been shown to pair with genetically dissimilar mates or with extra-pair partners that are more genetically compatible than their social mates, thereby increasing their offsprings' heterozygosity which often correlates with offspring fitness. While most studies have focused on genetically promiscuous species, few studies have addressed genetically monogamous species, in which mate choice tends to be mutual.</p> <p>Results</p> <p>Here, we used microsatellite markers to assess individual global heterozygosity and genetic similarity of pairs in a socially and genetically monogamous seabird, the black-legged kittiwake <it>Rissa tridactyla</it>. We found that pairs were more genetically dissimilar than expected by chance. We also identified fitness costs of breeding with genetically similar partners: (i) genetic similarity of pairs was negatively correlated with the number of chicks hatched, and (ii) offspring heterozygosity was positively correlated with growth rate and survival.</p> <p>Conclusion</p> <p>These findings provide evidence that breeders in a genetically monogamous species may avoid the fitness costs of reproducing with a genetically similar mate. In such species that lack the opportunity to obtain extra-pair fertilizations, mate choice may therefore be under high selective pressure.</p
Atomic characterization of Si nanoclusters embedded in SiO2 by atom probe tomography
Silicon nanoclusters are of prime interest for new generation of optoelectronic and microelectronics components. Physical properties (light emission, carrier storage...) of systems using such nanoclusters are strongly dependent on nanostructural characteristics. These characteristics (size, composition, distribution, and interface nature) are until now obtained using conventional high-resolution analytic methods, such as high-resolution transmission electron microscopy, EFTEM, or EELS. In this article, a complementary technique, the atom probe tomography, was used for studying a multilayer (ML) system containing silicon clusters. Such a technique and its analysis give information on the structure at the atomic level and allow obtaining complementary information with respect to other techniques. A description of the different steps for such analysis: sample preparation, atom probe analysis, and data treatment are detailed. An atomic scale description of the Si nanoclusters/SiO2 ML will be fully described. This system is composed of 3.8-nm-thick SiO layers and 4-nm-thick SiO2 layers annealed 1 h at 900°C
Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea
Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38â39 Mb genomes include 11,860â14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t
Atomic scale investigation of silicon nanowires and nanoclusters
In this study, we have performed nanoscale characterization of Si-clusters and Si-nanowires with a laser-assisted tomographic atom probe. Intrinsic and p-type silicon nanowires (SiNWs) are elaborated by chemical vapor deposition method using gold as catalyst, silane as silicon precursor, and diborane as dopant reactant. The concentration and distribution of impurity (gold) and dopant (boron) in SiNW are investigated and discussed. Silicon nanoclusters are produced by thermal annealing of silicon-rich silicon oxide and silica multilayers. In this process, atom probe tomography (APT) provides accurate information on the silicon nanoparticles and the chemistry of the nanolayers
Identification of road user related risk factors, deliverable 4.1 of the H2020 project SafetyCube.
Safety CaUsation, Benefits and Efficiency (SafetyCube) is a European Commission supported Horizon 2020 project with the objective of developing an innovative road safety Decision Support System (DSS). The DSS will enable policy-makers and stakeholders to select and implement the
most appropriate strategies, measures, and cost-effective approaches to reduce casualties of all road user types and all severities. This document is the first deliverable (4.1) of work package 4 which is dedicated to identifying and assessing human related risk factors and corresponding countermeasures as well as their effect on
road safety. The focus of deliverable 4.1 is on identification and assessment of risk factors and describes the corresponding operational procedure and corresponding outcomes. The following steps have been carried out:
Identification of human related risk factors â creation of a taxonomy
Consultation of relevant stakeholders and policy papers for identification of topic with high priority (âhot topicsâ)
Systematic literature search and selection of relevant studies on identified risk factors
âąCoding of studies
âąAnalysis of risk factors on basis of coded studies
âąSynopses of risk factors, including accident scenarios The core output of this task are synopses of risk factors which will be available through the DSS. Within the synopses, each risk factor was analysed systematically on basis of scientific studies and is further assigned to one of four levels of risk (marked with a colour code). Essential information of the more than 180 included studies were coded and will also be available in the database of the DSS. Furthermore, the synopses contain theoretical background on the risk factor and are prepared in different sections with different levels of detail for an academic as well as a non-academic audience. These sections are readable independently. It is important to note that the relationship between road safety and road user related risk factors is a difficult task. For some risk factors the available studies focused more on conditions of the behaviour (in which situations the behaviour is shown or which groups are more likely to show this
behaviour) rather than the risk factor itself. Therefore, it cannot be concluded that those risk factors that have not often been studied or have to rely more indirect and arguably weaker methodologies, e.g. self-reports , do not increase the chance of a crash occurring. The following analysed risk factors were assessed as âriskyâ, âprobably riskyâ or âunclearâ. No risk
factors were identified as âprobably not riskyâ.
Risky Probably risky Unclear
âą Influenced driving â alcohol
âą Influenced Driving â drugs
(legal & illegal)
âą Speeding and inappropriate
speed
âą Traffic rule violations â red
light running
âą Distraction â cell phone use
(hand held)
âą Distraction â cell phone use
(hands free)
âą Distraction â cell phone use
(texting)
âą Fatigue â sleep disorders â
sleep apnea
âą Risk taking â overtaking
âą Risk taking â close following
behaviour
âą Insufficient knowledge and
skills
âą Functional impairment â
cognitive impairment
âą Functional impairment â
vision loss
âą Diseases and disorders â
diabetes
âą Personal factors â sensation
seeking
âą Personal factors â ADHD
âą Emotions â anger, aggression
âą Fatigue â Not enough
sleep/driving while tired
âą Distraction â conversation
with passengers
âą Distraction â outside of
vehicle
âą Distraction â cognitive
overload and inattention
âą Functional impairment â
hearing loss (few studies)
âą Observation errors (few studies)
âą Distraction â music â
entertainment systems (many
studies, mixed results)
âą Distraction â operating devices
(many studies, mixed results)
The next step in SafetyCubeâs WP4 is to identify and assess the effectiveness of measures and to establish a link to the identified risk factors. The work of this first task indicates a set of risk factors
that should be centre of attention when identifying corresponding road safety measures (category âriskyâ)
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
Identification and safety effects of road user related measures. Deliverable 4.2 of the H2020 project SafetyCube
Safety CaUsation, Benefits and Efficiency (SafetyCube) is a European Commission supported
Horizon 2020 project with the objective of developing an innovative road safety Decision Support
System (DSS). The DSS will enable policy-makers and stakeholders to select and implement the
most appropriate strategies, measures, and cost-effective approaches to reduce casualties of all
road user types and all severities.
This document is the second deliverable (4.2) of work package 4, which is dedicated to identifying
and assessing road safety measures related to road users in terms of their effectiveness.
The focus of deliverable 4.2 is on the identification and assessment of countermeasures and
describes the corresponding operational procedure and outcomes. Measures which intend to
increase road safety of all kind of road user groups have been considered [...continues]
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGOâs first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
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