1,414 research outputs found
Diversiteit in het Europese talenonderwijs:Over praktische noodzaak en theoretische verdieping
An Alternative Approach to the Calculation and Analysis of Connectivity in the World City Network
Empirical research on world cities often draws on Taylor's (2001) notion of
an 'interlocking network model', in which office networks of globalized service
firms are assumed to shape the spatialities of urban networks. In spite of its
many merits, this approach is limited because the resultant adjacency matrices
are not really fit for network-analytic calculations. We therefore propose a
fresh analytical approach using a primary linkage algorithm that produces a
one-mode directed graph based on Taylor's two-mode city/firm network data. The
procedure has the advantage of creating less dense networks when compared to
the interlocking network model, while nonetheless retaining the network
structure apparent in the initial dataset. We randomize the empirical network
with a bootstrapping simulation approach, and compare the simulated parameters
of this null-model with our empirical network parameter (i.e. betweenness
centrality). We find that our approach produces results that are comparable to
those of the standard interlocking network model. However, because our approach
is based on an actual graph representation and network analysis, we are able to
assess cities' position in the network at large. For instance, we find that
cities such as Tokyo, Sydney, Melbourne, Almaty and Karachi hold more strategic
and valuable positions than suggested in the interlocking networks as they play
a bridging role in connecting cities across regions. In general, we argue that
our graph representation allows for further and deeper analysis of the original
data, further extending world city network research into a theory-based
empirical research approach.Comment: 18 pages, 9 figures, 2 table
Artificial neural networks for 3D cell shape recognition from confocal images
We present a dual-stage neural network architecture for analyzing fine shape
details from microscopy recordings in 3D. The system, tested on red blood
cells, uses training data from both healthy donors and patients with a
congenital blood disease. Characteristic shape features are revealed from the
spherical harmonics spectrum of each cell and are automatically processed to
create a reproducible and unbiased shape recognition and classification for
diagnostic and theragnostic use.Comment: 17 pages, 8 figure
Registration of Blood Exposure Accidents in the Netherlands by a Nationally Operating Call Center
Phosphatidic acid binding proteins display differential binding as a function of membrane curvature stress and chemical properties
Evaluating 35 Methods to Generate Structural Connectomes Using Pairwise Classification
There is no consensus on how to construct structural brain networks from
diffusion MRI. How variations in pre-processing steps affect network
reliability and its ability to distinguish subjects remains opaque. In this
work, we address this issue by comparing 35 structural connectome-building
pipelines. We vary diffusion reconstruction models, tractography algorithms and
parcellations. Next, we classify structural connectome pairs as either
belonging to the same individual or not. Connectome weights and eight
topological derivative measures form our feature set. For experiments, we use
three test-retest datasets from the Consortium for Reliability and
Reproducibility (CoRR) comprised of a total of 105 individuals. We also compare
pairwise classification results to a commonly used parametric test-retest
measure, Intraclass Correlation Coefficient (ICC).Comment: Accepted for MICCAI 2017, 8 pages, 3 figure
WLM-1: A Non-Rotating, Gravitationally Unperturbed, Highly Elliptical Extragalactic Globular Cluster
Globular clusters have long been known for presenting (at times) significant
deviations from spherical symmetry. While rotation has been the main proposed
explanation, other complicating factors such as their constant interaction with
the strong gravitational potential of their host galaxy have made it difficult
for a consensus to be reached. To address this question we have obtained
high-resolution spectra of WLM-1, the lone globular cluster associated with the
isolated, low-mass dwarf irregular galaxy WLM. Using archival HST WFPC2 data,
we measure the radial ellipticity profile of WLM-1, finding it to be highly
elliptical, with a mean value of 0.17 in the region 0.5-5" -- which is
comparable to what is found in our Galaxy for the most elliptical globular
clusters. There is no evidence of isophote twisting, except for the innermost
regions of the cluster (r < 0.5"). To investigate whether the observed
flattening can be ascribed to rotation, we have obtained long-slit
high-resolution VLT/UVES spectra of this cluster along and perpendicular to the
axis of flattening. Using cross-correlation we find that the velocity profile
of the cluster is consistent with zero rotation along either axis. Thus neither
cluster rotation nor galactic tides can be responsible for the flattened
morphology of WLM-1. We argue that the required velocity dispersion anisotropy
between the semi-major and semi-minor axes that would be required to account
for the observed flattening is relatively small, of order 1 km/s. Even though
our errors preclude us from conclusively establishing that such a difference
indeed exists, velocity anisotropy remains at present the most plausible
explanation for the shape of this cluster.Comment: 11 pages, 10 figures, submitted to the A
The association between preoperative body composition and aerobic fitness in patients scheduled for colorectal surgery
AIM: Although cardiopulmonary exercise testing (CPET) is considered the gold standard, a preoperative abdominal CT scan might also provide information concerning preoperative aerobic fitness for risk assessment. This study aimed to investigate the association between preoperative CTâscanâderived body composition variables and preoperative CPET variables of aerobic fitness in colorectal surgery. METHOD: In this retrospective cohort study, CT images at level L3 were analysed for skeletal muscle mass, skeletal muscle radiation attenuation, visceral adipose tissue (VAT) mass and subcutaneous adipose tissue mass. Regression analyses were performed to investigate the relation between CTâscanâderived body composition variables, CPETâderived aerobic fitness and other preoperative patientârelated variables. Logistic regression analysis was performed to predict a preoperative anaerobic threshold (AT) â€Â 11.1 ml/kg/min as cutâoff for having a high risk for postoperative complications. RESULTS: Data from 78 patients (45 men; mean [SD] age 74.5 [6.4 years]) were analysed. A correlation coefficient of 0.55 was observed between absolute AT and skeletal muscle mass index. Absolute AT (R (2) of 51.1%) was lower in patients with a lower skeletal muscle mass index, together with higher age, lower body mass and higher American Society of Anesthesiologists (ASA) score. Higher ASA score (odds ratio 5.64; P = 0.033) and higher VAT mass (odds ratio 1.02; P = 0.036) were associated with an increased risk of an AT â€Â 11.1 ml/kg/min. CONCLUSION: Body composition variables from the preoperative CT scan were moderately associated with preoperative CPETâderived aerobic fitness. Higher ASA score and higher VAT mass were associated with an increased risk of an AT â€Â 11.1 ml/kg/min
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