scholarly journals A Simulation of Information Exchange between Two Fish Swimming in a Water Tank

1997 ◽  
Vol 33 (12) ◽  
pp. 1187-1189
Author(s):  
Nobuo SANNOMIYA ◽  
Ko NAITO
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ehud Vinepinsky ◽  
Lear Cohen ◽  
Shay Perchik ◽  
Ohad Ben-Shahar ◽  
Opher Donchin ◽  
...  

Abstract Like most animals, the survival of fish depends on navigation in space. This capacity has been documented in behavioral studies that have revealed navigation strategies. However, little is known about how freely swimming fish represent space and locomotion in the brain to enable successful navigation. Using a wireless neural recording system, we measured the activity of single neurons in the goldfish lateral pallium, a brain region known to be involved in spatial memory and navigation, while the fish swam freely in a two-dimensional water tank. We found that cells in the lateral pallium of the goldfish encode the edges of the environment, the fish head direction, the fish swimming speed, and the fish swimming velocity-vector. This study sheds light on how information related to navigation is represented in the brain of fish and addresses the fundamental question of the neural basis of navigation in this group of vertebrates.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2131 ◽  
Author(s):  
Mu ◽  
Cao ◽  
Gong ◽  
Baiyin ◽  
Li

In fishway design, the combination of fish swimming behaviors and suitable fishway hydraulic characteristics increases the fish passage efficiency. In this study, the most representative grass carp among the “four major Chinese carps” was selected. Under conditions similar to the time period for feeding migration, juvenile grass carps were targeted to study the swimming characteristic indicators (i.e., critical and burst swimming speeds) and swimming behaviors that were closely associated with fishway hydraulic design using the incremental water velocity method in a homemade test water tank. (1) The study results reveal that both the absolute critical (Ucrit) and burst (Uburst) swimming speeds increased linearly with increasing body length and both the relative critical (U’crit) and burst (U′burst) swimming speeds decreased linearly with increasing body length. There existed a quantitative relationship between Uburst and Ucrit, which could facilitate the fishway hydraulic design. (2) This study analyzed the effects of water velocity changes on fish swimming behaviors and proposed a classification method for four fish swimming behaviors—swimming freely, staying, dashing at a long distance, and dashing at a short distance—of tested fish during the process of adapting to water velocity changes interspersed with one another. The entire swimming process under the incremental water velocity was divided into four stages. (3) This study suggests that the maximum water velocity of the mainstream in a fishway using grass carp as the major passage fish should not exceed 52–60% Uburst at stage 1. For the high-water velocity areas of a fishway, such as vertical slots and orifices, the optimal water velocity should not be higher than 76–79% Uburst at stage 2 and should absolutely not exceed 90–96% Uburst at stage 3.


2007 ◽  
Author(s):  
Stephen E. Humphrey ◽  
Susan Mohammed
Keyword(s):  

1998 ◽  
Vol 37 (03) ◽  
pp. 247-253 ◽  
Author(s):  
K. Ohe ◽  
S. Kaihara ◽  
T. Kiuchi

AbstractWWW-based user interface is presented for secure electronic mail service for healthcare users. Using this method, communications between an electronic mail (WWW) server and users (WWW browsers) can be performed securely using Secure Socket Layer protocol-based Hypertext Transfer Protocol (SSL-HTIP). The mail can be encrypted, signed, and sent to the recipients and vice versa on the remote WWW server. The merit of this method is that many healthcare users can use a secure electronic mail system easily and immediately, because SSL-compatible WWW browsers are widely used and this system can be made available simply by installing a WWW-based mail user agent on a mail server. We implemented a WWWbased mail user agent which is compatible with PEM-based secure mail and made it available to about 16,000 healthcare users. We believe this approach is effective in facilitating secure network-based information exchange among medical professionals.


This study investigated the use of e-Procurement in selected construction firms in Oyo state, Nigeria. The data were derived using a well-structured questionnaire survey involving 104 respondents. Descriptive statistical and correlation analyses were used to analyze the data. Findings show that the use of electronic procurement in the selected construction firms for carrying out procurement function is high with majority of the professionals affirming the use of the system, the four categories of e-Procurement used were e-mail, static websites, web.2.0 technologies and portals that have capabilities of supporting the execution of functions limited to intra and inter firm communication and exchange of project information and data. Consequently, between 84 percent and 76 percent of the respondents used these e-Procurement technologies for communication of information, exchange of bill of quantities, project reports, CAD drawings and project specifications. Consequently, factors with the highest positive impacts on the use of these technologies in the firms were the speed of transactions, lower transaction cost and ease of use. The study implies that the selected construction firms in Oyo state Nigeria predominantly use e-mails and websites to support the execution of pre-award phase of construction procurement. Finding also shows that there is positive relationship between e-Procurement (e-Notifying, e-Exchange, and e-Submission of bid) and Project delivery. The study suggests that to accelerate the rate of uptake of e-Procurement and maximize its benefits in the Nigerian construction industry, there is a need to improve the quality and quantity of ICT infrastructure across the country; and to embark on aggressive enlightenment campaigns, training and skill development programs in the use of e-Procurement in the construction industry in this country.


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