205 research outputs found
Effects of the distant population density on spatial patterns of demographic dynamics
Spatiotemporal patterns of population changes within and across countries
have various implications. Different geographical, demographic and
econo-societal factors seem to contribute to migratory decisions made by
individual inhabitants. Focussing on internal (i.e., domestic) migration, we
ask whether individuals may take into account the information on the population
density in distant locations to make migratory decisions. We analyse population
census data in Japan recorded with a high spatial resolution (i.e., cells of
size 500 m 500 m) for the entirety of the country and simulate
demographic dynamics induced by the gravity model and its variants. We show
that, in the census data, the population growth rate in a cell is positively
correlated with the population density in nearby cells up to a radius of 20 km
as well as that of the focal cell. The ordinary gravity model does not capture
this empirical observation. We then show that the empirical observation is
better accounted for by extensions of the gravity model such that individuals
are assumed to perceive the attractiveness, approximated by the population
density, of the source or destination cell of migration as the spatial average
over a radius of km.Comment: 22 figures, 2 tables, fixed an incorrect publication yea
Win-stay lose-shift strategy in formation changes in football
Managerial decision making is likely to be a dominant determinant of
performance of teams in team sports. Here we use Japanese and German football
data to investigate correlates between temporal patterns of formation changes
across matches and match results. We found that individual teams and managers
both showed win-stay lose-shift behavior, a type of reinforcement learning. In
other words, they tended to stick to the current formation after a win and
switch to a different formation after a loss. In addition, formation changes
did not statistically improve the results of succeeding matches.The results
indicate that a swift implementation of a new formation in the win-stay
lose-shift manner may not be a successful managerial rule of thumb.Comment: 7 figures, 11 table
Population changes in residential clusters in Japan
Population dynamics in urban and rural areas are different. Understanding
factors that contribute to local population changes has various socioeconomic
and political implications. In the present study, we use population census data
in Japan to examine contributors to the population growth of residential
clusters between years 2005 and 2010. The data set covers the entirety of Japan
and has a high spatial resolution of 500500, enabling us
to examine population dynamics in various parts of the country (urban and
rural) using statistical analysis. We found that, in addition to the area,
population density, and age, the shape of the cluster and the spatial
distribution of inhabitants within the cluster are significantly related to the
population growth rate of a residential cluster. Specifically, the population
tends to grow if the cluster is "round" shaped (given the area) and the
population is concentrate near the center rather than periphery of the cluster.Comment: 3 figures, 4 table
Predictors of cognitive function in patients with hypothalamic hamartoma following stereotactic radiofrequency thermocoagulation surgery
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138275/1/epi13838.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138275/2/epi13838_am.pd
Estimating Body Stiffness in Quadrupedal Locomotion using the Flexible Shoulder as a Physical Reservoir
The 11th International Symposium on Adaptive Motion of Animals and Machines. Kobe University, Japan. 2023-06-06/09. Adaptive Motion of Animals and Machines Organizing Committee.Poster Session P1
Twisted mass transport enabled by the angular momentum of light
The authors acknowledge support in the form of KAKENHI Grants-in-Aid (Grant Nos. JP 16H06507, JP 17K19070, and JP 18H03884) from the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST) CREST Grant No. (JPMJCR1903), and the U.S. National Science Foundation Award #1809518. KD and YA thank the UK Engineering and Physical Sciences Research Council for funding (through Grant No. EP/P030017/1).Light may carry both orbital angular momentum (AM) and spin AM. The former is a consequence of its helical wavefront, and the latter is a result of its rotating transverse electric field. Intriguingly, the light–matter interaction with such fields shows that the orbital AM of light causes a physical “twist” in a range of materials, including metal, silicon, azopolymer, and even liquid-phase resin. This process may be aided by the light’s spin AM, resulting in the formation of various helical structures. The exchange between the AM of light and matter offers not only unique helical structures at the nanoscale but also entirely novel fundamental phenomena with regard to the light–matter interaction. This will lead to the future development of advanced photonics devices, including metamaterials for highly sensitive detectors as well as reactions for chiral chemical composites. Here, we focus on interactions between the AM of light and azopolymers, which exhibit some of the most diverse structures and phenomena observed. These studies result in helical surface relief structures in azopolymers and will leverage next-generation applications with light fields carrying optical AM.Publisher PDFPeer reviewe
Impact of the Coronary Flow Reduction at Rest on Myocardial Perfusion and Functional Indices Derived from Myocardial Contrast and Strain Echocardiography
Background: The severity of the coronary flow reduction that corresponds to myocardial perfusion and functional abnormalities remains unclear. We estimated the impact of various severities of flow-limiting coronary stenosis at rest on myocardial perfusion and functional indices from myocardial contrast echocardiography and tissue strain imaging and characterized the relationship between both the indices. Methods: Four levels of flow-limiting stenoses (slight, mild, moderate, severe) of the left circumflex coronary artery were examined in 10 open-chest dogs. In the left circumflex coronary artery area, plateau videointensity and time to plateau (TP) of the replenishment curve from myocardial contrast echocardiography were calculated for perfusion analysis, and peak systolic strain and postsystolic strain index (PSI) from tissue strain imaging were measured for functional analysis. Results: Plateau videointensity and peak systolic strain tended to decrease with increased severity of stenosis, although these differences did not reach the level of statistical significance. TP and PSI were significantly increased in the context of moderate (≥30-<50%) and severe (≥50%) flow reduction when compared to baseline values (TP, moderate 1.69 ± 0.20 and severe 1.77 ± 0.25 vs baseline 0.93 ± 0.17, P < .01, respectively; PSI, moderate 0.96 ± 0.15 and severe 1.28 ± 0.32 vs baseline 0.59 ± 0.18, P < .05 and P < .01, respectively). Further, TP and PSI were positively correlated with flow reduction (r = 0.81 and r = 0.84, P < .0001, respectively), and PSI was positively correlated with TP (r = 0.72, P < .0001). Conclusions: In contrast to conventional indices, such as plateau videointensity and peak systolic strain, novel indices, such as TP and PSI, were both able to detect 30% or greater coronary flow reduction at rest. © 2006 American Society of Echocardiography.Okuda K, Asanuma T, Hirano T, Masuda K, Otani K, Ishikura F, Beppu S. Impact of the coronary flow reduction at rest on myocardial perfusion and functional indices derived from myocardial contrast and strain echocardiography. J Am Soc Echocardiogr. 2006 Jun;19(6):781-7. doi: 10.1016/j.echo.2005.10.016
Deep Learning Predicts Rapid Over-softening and Shelf Life in Persimmon Fruits
In contrast to the progress in the research on physiological disorders relating to shelf life in fruit crops, it has been difficult to non-destructively predict their occurrence. Recent high-tech instruments have gradually enabled non-destructive predictions for various disorders in some crops, while there are still issues in terms of efficiency and costs. Here, we propose application of a deep neural network (or simply deep learning) to simple RGB images to predict a severe fruit disorder in persimmon, rapid over-softening. With 1,080 RGB images of ‘Soshu’ persimmon fruits, three convolutional neural networks (CNN) were examined to predict rapid over-softened fruits with a binary classification and the date to fruit softening. All of the examined CNN models worked successfully for binary classification of the rapid over-softened fruits and the controls with > 80% accuracy using multiple criteria. Furthermore, the prediction values (or confidence) in the binary classification were correlated to the date to fruit softening. Although the features for classification by deep learning have been thought to be in a black box by conventional standards, recent feature visualization methods (or “explainable” deep learning) has allowed identification of the relevant regions in the original images. We applied Grad-CAM, Guided backpropagation, and layer-wise relevance propagation (LRP), to find early symptoms for CNNs classification of rapid over-softened fruits. The focus on the relevant regions tended to be on color unevenness on the surface of the fruit, especially in the peripheral regions. These results suggest that deep learning frameworks could potentially provide new insights into early physiological symptoms of which researchers are unaware
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