scholarly journals Evolution of switchable aposematism: insights from individual-based simulations

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8915
Author(s):  
Woncheol Song ◽  
Sang-im Lee ◽  
Piotr G. Jablonski

Some defended prey animals can switch on their normally hidden aposematic signals. This switching may occur in reaction to predators’ approach (pre-attack signals) or attack (post-attack signals). Switchable aposematism has been relatively poorly studied, but we can expect that it might bring a variety of benefits to an aposmetic organism. First, the switching could startle the predators (deimatism). Second, it could facilitate aversive learning. Third, it could minimize exposure or energetic expense, as the signal can be switched off. These potential benefits might offset costs of developing, maintaining and utilizing the switchable traits. Here we focused on the third benefit of switchability, the cost-saving aspect, and developed an individual-based computer simulation of predators and prey. In 88,128 model runs, we observed evolution of permanent, pre-attack, or post-attack aposematic signals of varying strength. We found that, in general, the pre-attack switchable aposematism may require moderate predator learning speed, high basal detectability, and moderate to high signal cost. On the other hand, the post-attack signals may arise under slow predator learning, low basal detectability and high signal cost. When predator population turnover is fast, it may lead to evolution of post-attack aposematic signals that are not conforming to the above tendency. We also suggest that a high switching cost may exert different selection pressure on the pre-attack than the post-attack switchable strategies. To our knowledge, these are the first theoretical attempts to systematically explore the evolution of switchable aposematism relative to permanent aposematism in defended prey. Our simulation model is capable of addressing additional questions beyond the scope of this article, and we open the simulation software, program manual and source code for free public use.

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1279
Author(s):  
Amaya Martínez-Gracia ◽  
Sergio Usón ◽  
Mª Teresa Pintanel ◽  
Javier Uche ◽  
Ángel A. Bayod-Rújula ◽  
...  

A real case study of an energy system based on a Solar Assisted Heat Pump (SAHP) fed by hybrid photovoltaic-thermal solar panels (PVT) and seasonal storage (SS) is presented in this paper. Exergy and exergy cost analyses are proposed as complementary methods for the assessment and better understanding of the efficiency of this cogeneration solar configuration. The system performance takes advantage of storage heat in summer, when the solar resource is high in Spain, and is then later consumed during the cold winter (heating season). The building is devoted to social housing, and it is currently under construction. The assessment is based on simulations developed using TRNSYS, a dynamic simulation software for energy systems. Results show that the unit exergy cost of the solar field is around 6. The cost of the seasonal storage is higher, about 13, and its formation is affected both by its own irreversibility and by the irreversibility of the PVT solar field. The cost of the heat delivered by the heat pump is around 15, being affected by all the upstream units and even by the grid. Besides, the analysis points out strategies for improving the system efficiency, such as increasing the size of the storage tank or improving the control strategy of the boiler.


2013 ◽  
Vol 718-720 ◽  
pp. 1645-1650
Author(s):  
Gen Yin Cheng ◽  
Sheng Chen Yu ◽  
Zhi Yong Wei ◽  
Shao Jie Chen ◽  
You Cheng

Commonly used commercial simulation software SYSNOISE and ANSYS is run on a single machine (can not directly run on parallel machine) when use the finite element and boundary element to simulate muffler effect, and it will take more than ten days, sometimes even twenty days to work out an exact solution as the large amount of numerical simulation. Use a high performance parallel machine which was built by 32 commercial computers and transform the finite element and boundary element simulation software into a program that can running under the MPI (message passing interface) parallel environment in order to reduce the cost of numerical simulation. The relevant data worked out from the simulation experiment demonstrate that the result effect of the numerical simulation is well. And the computing speed of the high performance parallel machine is 25 ~ 30 times a microcomputer.


2014 ◽  
Vol 933 ◽  
pp. 874-878
Author(s):  
Yun Rui Wang

Inventory is an important link in supply chain, according to characteristics and objectives of inventory control, the reasonable safety inventory, order point, the highest inventory and inventory strategy were determined based on historical sales data. Using Witness simulation software, the optimal strategy was selected from nine inventory strategies by running simulation model for one year. If goods shortage was allowing, the seventh schemes (72000,158100) was better ,the minimum total cost was 888158 yuan ; considering allowing a small amount of shortage, the cost of eighth schemes ( 82000,158100) was least of 1095167; the third scenarios (92000,138100) was selected if without shortage, and the minimum total cost was 1254909 yuan. This shows, the application of computer simulation to assist in the management of inventory is scientific and feasible, it can help enterprises to save the order and operation cost.


2015 ◽  
Vol 17 (1) ◽  
Author(s):  
Madeleine Fombad

Background: Law firms in Botswana offer a particularly interesting context to explore the effects of transition in the knowledge economy. Acquiring and leveraging knowledge effectively in law firms through knowledge management can result in competitive advantage; yet the adoption of this approach remains in its infancy. Objectives: This article investigates the factors that will motivate the adoption of knowledge management in law firms in Botswana, and creates an awareness of the potential benefits of knowledge management in these firms.Method: The article uses both quantitative and qualitative research methods and the survey research design. A survey was performed on all 115 registered law firms and 217 lawyers in Botswana. Interviews were conducted with selected lawyers for more insight. Results: Several changes in the legal environment have motivated law firms to adopt knowledge management. Furthermore, lawyers appreciate the potential benefits of knowledge management. Conclusion: With the rise of the knowledge-based economy, coupled with the pressures faced by the legal industry in recent years, law firms in Botswana can no longer afford to rely on the traditional methods of managing knowledge. Knowledge management will, therefore, enhance the cost effectiveness of these firms. Strategic knowledge management certainly helps to prepare law firms in Botswana to be alive to the fact that the systematic harnessing of legal knowledge is no longer a luxury, but an absolute necessity in the knowledge economy. It will also provide an enabling business environment for private sector development and growth and, therefore, facilitate Botswana’s drive towards the knowledge-based economy.


2015 ◽  
Vol 799-800 ◽  
pp. 1154-1157
Author(s):  
Chen Hua She ◽  
Jian Yu Lin ◽  
Shen Yung Lin

To develop the numerical control program of mill-turn machine, the traditional method is to apply the computer-aided design and manufacture software to construct the geometric model, then to generate tool path and convert the path to NC program. For complex numerical control program of mill-turn machine, such as the multiple turret synchronized motion machining, because of the need to control time sequence, the NC program is highly required on using of dedicated software system. The objective of this paper is to establish a mill-turn machining system with window interface of via the language of Borland C++ Builder. The developed system can plan the machining path of simple mill-turn features, including turning shape, axial slot milling, and radial packet milling, and generate the corresponding NC program. For the milling functions, after the offset coordinates are calculated along the polygonal angle vector in the center point of cutters, the NC program is generated. For the turning functions, through importing the 2D DXF (Drawing Exchange Format) file and inputting related configurations, the entity coordinates can be retrieved and the corresponding NC program is then converted. By means of the solid cutting simulation software and practical cutting experiment for the generated numerical control program, the accuracy of the tool path generation algorithm is confirmed. Hence, the cost of purchasing commercial software can be saved and the time of generating program can also be decreased so that the working efficiency can be enhanced.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 153-153
Author(s):  
Matthew J Soyland ◽  
Isabella V Panetta ◽  
Bailey Armentrout-Shoaf ◽  
Christina Rocco ◽  
Toree Williams

Abstract Organic products have been growing in popularity in the consumer market, often without evidence to support potential benefits. Many organic products promise better results than conventional products, yet research examining the use of organic products as a feedstuff in caprine diets is lacking. Additionally, the cost of organic feedstuff is much greater when compared to conventional. Reproductive success of an animal has a direct correlation with nutrition throughout pregnancy and could be impacted by organic products. Thus, potential benefits of increase of reproductive health could outweigh the initial cost of organic feedstuffs. The objective of the current study was to determine differences in dystocia occurrence between caprine dams fed conventional and organic feedstuffs in the last 6 wk of gestation. Eight gestating Nubian does (n = 4) ranging from 1 to 5 yr of age with initial BW between 45.4 and 68.5 kg were separated into two treatment groups based on BCS utilizing the American Dairy Goat Association’s BCS 1 to 5 scale. Treatment A was fed a conventional diet including 14% CP concentrate, mineral supplementation, and molasses. Treatment B was fed an equivalent USDA certified organic concentrate, mineral supplement and molasses. Dams were fed 0.907kg/d/45.4kg of BW of concentrate and mineral supplement at 0.012kg/d/45.4kg of BW in individual feeding stocks at 0630 and 1730 in the last 6 wk of gestation. All Dams were provided ad libitum to hay and water. During parturition, dystocia was defined as requiring obstetrical assistance at any point during kidding. Differences in dystocia rate between conventional and organic groups were analyzed by independent T-Test at P < 0.05. As expected, no differences were observed between organic and conventional treatment groups (p = 0.28). As a result, the increased priced of organic feedstuff was not justified for feeding over conventional products.


1983 ◽  
Vol 92 (6_suppl) ◽  
pp. 32-33
Author(s):  
J. S. Supance ◽  
P. H. Kaleida ◽  
M. L. Casselbrant ◽  
M. M. Blatter ◽  
K. S. Reisinger ◽  
...  

Prevention and safe and effective treatment of otitis media are two of our ultimate research goals. Both of these require that a variety of medical and surgical methods of management be evaluated. The most frequent medical management of otitis media is the administration of antibiotics, decongestants, and antihistamines; therefore, several studies that are either randomized placebo-controlled clinical trials or drug efficacy studies have been undertaken. Also, pharmacokinetic studies either have been performed or are underway to determine the ability of drugs to achieve appropriate blood and middle ear levels. The most common methods of surgical management are myringotomy with or without tympanostomy tube insertion, and adenoidectomy with or without tonsillectomy. Randomized controlled clinical trials are being conducted to determine the efficacy and risk/benefit of these procedures at various stages and levels of severity of otitis media in children. In addition, we are attempting to address the problem of the cost of these methods in relation to their potential benefits.


2012 ◽  
Vol 510 ◽  
pp. 541-544
Author(s):  
Bing Zhong

The motion of amplification frame of dumper was simulated by multi-body dynamics simulation software ADAMS, and the danger working conditions of amplification frame were calculated. The stress of amplification frame was simulated and analyzed by Optistruct software. The results show that the stress distribution in amplification frame is not uniform and it is big in the middle and small in the edge zeros. The structure of amplification is optimized according to the simulation results. The utilization ratio of the material increases and the cost of production decreases after structural optimization.


2020 ◽  
Author(s):  
Rafael Costa Fernandes ◽  
Paulo Sergio Silva ◽  
Felipe Ieda Fazanaro ◽  
Diego Paolo Ferruzzo Correa

This work discusses the development of a hybrid estimation algorithm based on computer vision and microelectromechanical system sensors. A mathematical enviroment was developed to simulate the dynamics of the quadrotor and its sensors, a 3D simulation software was also developed, simulating a on-board camera. The results obtained were compared to a TRIAD/MEMS attitude and position estimation technique. A fourty times increase in precision was shown, at the cost of five times additional computational processing time.


Author(s):  
Naomi F Green ◽  
Holly H Urquhart ◽  
Cedric P van den Berg ◽  
N Justin Marshall ◽  
Karen L Cheney

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