98 research outputs found
Septal aperture of the humerus: Aetiology and frequency rates in two European populations.
Analysis of the septal aperture was conducted on two documented European populations. Collections from the National Museum of Natural History Lisbon, Portugal and University of Athens, Greece were used for the study. Both collections are modern and documented for sex and age. The Portuguese sample comprises 297 individuals (149 males and 148 females) between the ages of 18 and 88. A septal aperture was observed in 50 individuals resulting in a frequency of 16.83%. The Greek sample comprises 117 individuals (68 males and 49 females) between the ages of 20 and 65. Twenty-five septal apertures were observed, giving a frequency of 21.37%. Both populations had high frequencies which exceeded those observed in European countries in previous studies. Sex analysis shows that both samples confirm that septal apertures are more common in females. The Portuguese sample also supports that septal apertures are more common in the left humerus, however the Greek sample had a higher frequency of bilateral cases. Measurements of the Portuguese sample were taken to determine whether robusticity correlates with presence of septal apertures. These measurements concluded that there was no difference in robusticity with presence or absence of a septal aperture, challenging previous studies
Investigation of carrier confinement in direct bandgap GeSn/SiGeSn 2D and 0D heterostructures
Since the first demonstration of lasing in direct bandgap GeSn semiconductors, the research efforts for the realization of electrically pumped group IV lasers monolithically integrated on Si have significantly intensified. This led to epitaxial studies of GeSn/SiGeSn hetero- and nanostructures, where charge carrier confinement strongly improves the radiative emission properties. Based on recent experimental literature data, in this report we discuss the advantages of GeSn/SiGeSn multi quantum well and quantum dot structures, aiming to propose a roadmap for group IV epitaxy. Calculations based on 8-band k∙p and effective mass method have been performed to determine band discontinuities, the energy difference between Γ- and L-valley conduction band edges, and optical properties such as material gain and optical cross section. The effects of these parameters are systematically analyzed for an experimentally achievable range of Sn (10 to 20 at.%) and Si (1 to 10 at.%) contents, as well as strain values (−1 to 1%). We show that charge carriers can be efficiently confined in the active region of optical devices for experimentally acceptable Sn contents in both multi quantum well and quantum dot configurations
Observing the Observer (I): Meta-Bayesian Models of Learning and Decision-Making
In this paper, we present a generic approach that can be used to infer how subjects make optimal decisions under uncertainty. This approach induces a distinction between a subject's perceptual model, which underlies the representation of a hidden "state of affairs" and a response model, which predicts the ensuing behavioural (or neurophysiological) responses to those inputs. We start with the premise that subjects continuously update a probabilistic representation of the causes of their sensory inputs to optimise their behaviour. In addition, subjects have preferences or goals that guide decisions about actions given the above uncertain representation of these hidden causes or state of affairs. From a Bayesian decision theoretic perspective, uncertain representations are so-called "posterior" beliefs, which are influenced by subjective "prior" beliefs. Preferences and goals are encoded through a "loss" (or "utility") function, which measures the cost incurred by making any admissible decision for any given (hidden) state of affair. By assuming that subjects make optimal decisions on the basis of updated (posterior) beliefs and utility (loss) functions, one can evaluate the likelihood of observed behaviour. Critically, this enables one to "observe the observer", i.e. identify (context-or subject-dependent) prior beliefs and utility-functions using psychophysical or neurophysiological measures. In this paper, we describe the main theoretical components of this meta-Bayesian approach (i.e. a Bayesian treatment of Bayesian decision theoretic predictions). In a companion paper ('Observing the observer (II): deciding when to decide'), we describe a concrete implementation of it and demonstrate its utility by applying it to simulated and real reaction time data from an associative learning task
Pan-cancer analysis of whole genomes
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
Medium-Induced Modification of Z-Tagged Charged Particle Yields in Pb+Pb Collisions at 5.02 TeV with the ATLAS Detector
The yield of charged particles opposite to a
Z
boson with large transverse momentum (
p
T
) is measured in
260
pb
−
1
of
p
p
and
1.7
nb
−
1
of
Pb
+
Pb
collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider. The
Z
boson tag is used to select hard-scattered partons with specific kinematics, and to observe how their showers are modified as they propagate through the quark-gluon plasma created in
Pb
+
Pb
collisions. Compared with
p
p
collisions, charged-particle yields in
Pb
+
Pb
collisions show significant modifications as a function of charged-particle
p
T
in a way that depends on event centrality and
Z
boson
p
T
. The data are compared with a variety of theoretical calculations and provide new information about the medium-induced energy loss of partons in a
p
T
regime difficult to measure through other channels
A special crack tip element for bending of plates with through cracks from a sixth-order plate theory
A special crack tip element for bending of plates with through cracks is developed. The element formulation is based on a general crack tip solution obtained from a continuum analysis based on Mindlin's theory satisfying all the three natural conditions on crack surface. A special feature of the element formulation is that, in setting up of the element stiffness matrix, only line integrations are involved rather than usual area integration, thus enabling the choice of any shape for the element. It is demonstrated through numerical examples that this crack tip element can be used in combination with conventional elements for accurate evaluation of stress intensity factors in practical problems. Numerical studies reveal that there exists an optimum crack tip element size with reference to thickness of plate which gives the best possible value of stress intensity factor
Not Available
Not AvailableThe present study, investigate the socio-economic and other farm level factors influencing the decision making pattern in adopting agricultural innovations by farmers of Karnataka, India. A secondary data on decision pattern in adoption of agricultural innovations, socio-economic and other farm level factors of 372 farmers was considered. Multinomial logistic regression model was employed to identify potential influencing factors for decision making pattern by farmers. The result revealed that age, family size, socio-economic status (SES total score), yield, cost of cultivation, number of innovations adopted, gross income and net income were found to be significantly (p<0.05) influencing factors for the decision making patterns viz, informed and induced categories in adopting agricultural innovations. In conclusion, farmers were facing difficulty in decisions making at several situations towards adoption of any new innovations in agriculture mainly because of inadequate information or awareness about new innovations. Farmers need to have more awareness on their economic status, benefit-cost of different crops, adoption of appropriate innovations which controls the decision making pattern of farmers in perception of any new technology.Not Availabl
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