Spatio-temporal learning by the ant ectatomma ruidum

1999 ◽  
Vol 202 (14) ◽  
pp. 1897-1907 ◽  
Author(s):  
B. Schatz ◽  
J.P. Lachaud ◽  
G. Beugnon
Keyword(s):  
Food Delivery ◽  
Temporal Memory ◽  
Feeding Sites ◽  
Spatial Changes ◽  
Daily Schedule ◽  
Ectatomma Ruidum ◽  
Temporal And Spatial ◽  
Spatio Temporal ◽  
Field And Laboratory Conditions ◽  
Temporal Learning

We tested, under field and laboratory conditions, whether the neotropical ant Ectatomma ruidum Roger can learn several associations between temporal and spatial changes in the daily pattern of food availability. Honey was shuffled between two or three feeding sites following a fixed daily schedule. Foragers learnt to associate particular sites with the specific times at which food was available, individually marked ants being observed on the correct sites at the correct times. Some ants anticipated the time of food delivery by approximately 30 min, and it was not necessary for them to be rewarded at the first stage of the sequence of food collection to continue their search for honey according to the correct schedule of reward. Ants also followed the same schedule when no honey was supplied at each stage of the sequence, and they stayed at the expected unrewarded site for a period equivalent to the reward period of the corresponding training phase, indicating that they had learnt when and for how long the food was available. Thus, ants rely on their spatio-temporal memory rather than on local cues coming from the honey source to guide them.

Temporal and spatial variation of catastrophic river floodings in the Lower Yellow River from AD 960 to 1938

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1359-1369 ◽  
Author(s):  
Xiangping Zhang ◽  
Xiuqi Fang
Keyword(s):  
Yellow River ◽  
Spatial Scales ◽  
Alluvial Fan ◽  
Lower Yellow River ◽  
The Lower Yellow River ◽  
Spatial Changes ◽  
Temporal And Spatial ◽  
Spatio Temporal ◽  
Downstream Movement ◽  
Past 1000 Years

This study is intended to investigate the patterns for the temporal and spatial changes of catastrophic river floodings which took place in the Lower Yellow River, based on the available records collected from historical documents, and rearranged in a GIS database. A series of catastrophic river floodings from AD 960 to 1938 was reconstructed, and their temporal and spatial variations were analyzed, which leads to the conclusions, among others. (1) The increasing trend of frequency of catastrophic river floodings in the Lower Yellow River is not so significant in the past 1000 years. (2) Most dike breachings and overtoppings occurred near the apex of the Yellow River Alluvial Fan, and the number of dike breaching and overtopping was gradually reduced as the elevation decreased. (3) Under different spatio-temporal backgrounds, dike breaching and overtopping developed either downstream or upstream, which is evidenced by both the downstream movement for large temporal and spatial scales in dike breaching and overtopping places in AD 1128–1344 and 1391–1447 and the upstream movement for small temporal and spatial scales in AD 960–969, 1730–1761, and 1807–1819.

scholarly journals Spatio-Temporal Learning of Basketball Offensive Strategies

2015 ◽  
Author(s):  
Ching-Hang Chen ◽  
Tyng-Luh Liu ◽  
Yu-Shuen Wang ◽  
Hung-Kuo Chu ◽  
Nick C. Tang ◽  
...  
Keyword(s):  
Spatio Temporal ◽  
Temporal Learning ◽  
Offensive Strategies

VIDEO-SHOT TRANSITION DETECTION: A SPATIO-TEMPORAL SALIENCY APPROACH

2010 ◽  
Vol 24 (08) ◽  
pp. 1295-1309 ◽  
Author(s):  
XIAN WU ◽  
JIANHUANG LAI ◽  
PONG C. YUEN
Keyword(s):  
Error Probability ◽  
Spatial Information ◽  
Saliency Map ◽  
Detection Error ◽  
Novel Approach ◽  
Video Shot ◽  
Recent Method ◽  
Temporal And Spatial ◽  
Spatio Temporal ◽  
Shot Transitions

This paper proposes a novel approach for video-shot transition detection using spatio-temporal saliency. Both temporal and spatial information are combined to generate a saliency map, and features are available based on the change of saliency. Considering the context of shot changes, a statistical detector is constructed to determine all types of shot transitions by the minimization of the detection-error probability simultaneously under the same framework. The evaluation performed on videos of various content types demonstrates that the proposed approach outperforms a more recent method and two publicly available systems, namely VideoAnnex and VCM.

scholarly journals Temporal and spatial changes in wall shear stress during atherosclerotic plaque progression in mice

2018 ◽  
Vol 5 (3) ◽  
pp. 171447 ◽  
Author(s):  
R. Xing ◽  
A. M. Moerman ◽  
Y. Ridwan ◽  
M. J. Daemen ◽  
A. F. W. van der Steen ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Mouse Model ◽  
Atherosclerotic Plaque ◽  
Proximal Part ◽  
Plaque Progression ◽  
Plaque Composition ◽  
Spatial Changes ◽  
Temporal And Spatial ◽  
Wall Shear

Wall shear stress (WSS) is involved in atherosclerotic plaque initiation, yet its role in plaque progression remains unclear. We aimed to study (i) the temporal and spatial changes in WSS over a growing plaque and (ii) the correlation between WSS and plaque composition, using animal-specific data in an atherosclerotic mouse model. Tapered casts were placed around the right common carotid arteries (RCCA) of ApoE −/− mice. At 5, 7 and 9 weeks after cast placement, RCCA geometry was reconstructed using contrast-enhanced micro-CT. Lumen narrowing was observed in all mice, indicating the progression of a lumen intruding plaque. Next, we determined the flow rate in the RCCA of each mouse using Doppler Ultrasound and computed WSS at all time points. Over time, as the plaque developed and further intruded into the lumen, absolute WSS significantly decreased. Finally at week 9, plaque composition was histologically characterized. The proximal part of the plaque was small and eccentric, exposed to relatively lower WSS. Close to the cast a larger and concentric plaque was present, exposed to relatively higher WSS. Lower WSS was significantly correlated to the accumulation of macrophages in the eccentric plaque. When pooling data of all animals, correlation between WSS and plaque composition was weak and no longer statistically significant. In conclusion, our data showed that in our mouse model absolute WSS strikingly decreased during disease progression, which was significantly correlated to plaque area and macrophage content. Besides, our study demonstrates the necessity to analyse individual animals and plaques when studying correlations between WSS and plaque composition.

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