scholarly journals Tail regeneration after autotomy revives survival: a case from a long-term monitored lizard population under avian predation

2017 ◽  
Vol 284 (1847) ◽  
pp. 20162538 ◽  
Author(s):  
Jhan-Wei Lin ◽  
Ying-Rong Chen ◽  
Ying-Han Wang ◽  
Kuen-Chih Hung ◽  
Si-Min Lin

Caudal autotomy in lizards has intrigued scientists for more than 100 years. Because of the relative lack of literature under natural conditions, the complicated association among field autotomy rate, real predation pressure, the long-term cost of tail loss, and the benefit of regeneration remains equivocal. In this study, we conducted a 7-year capture–mark–recapture (CMR) programme with a wild population of a sexually dichromatic lizard, Takydromus viridipunctatus . We used autotomy indexes and a contemporary bird census mega-dataset of four predatory birds as predictors to examine the association between tail loss and predation pressure. We further estimated the survival cost of tail loss and alleviation by regeneration under natural conditions through CMR modelling. We found that large and small avian predators affect lizard survival through the following two routes: the larger-sized cattle egret causes direct mortality while the smaller shrikes and kestrels are the major causes of autotomy. Following autotomy, the survival rate of tailless individuals over the next month was significantly lower than that of tailed individuals, especially males during the breeding season, which showed a decline of greater than 30%. This sex-related difference further demonstrated the importance of reproductive costs for males in this sexually dichromatic species. However, the risk of mortality returned to baseline after the tails were fully grown. This study indicates the benefit of tail regeneration under natural conditions, which increases our understanding of the cost–benefit dynamics of caudal autotomy and further explains the maintenance of this trait as an evolutionarily beneficial adaption to long-term predator–prey interactions.

Author(s):  
Šubat-Dežulović Mirna ◽  
Pelčić Gordana ◽  
Valković Ana ◽  
Flajšman-Raspor Sanja ◽  
Pelčić Goran ◽  
...  

Cystic Fibrosis (CF) is a common inherited disease with reported mean prevalence of 0.737/10,000 in 27 EU countries (Farrell J Cyst Fibros. 2008). Still, many EU countries have not implemented CF in the Newborn Screening (NBS) programme, including our country. We report the case of a 7-month-old boy whose presenting signs of CF were life-threatening neurological symptoms caused by severe metabolic alkalosis and hypoelectrolytemia. By presenting this case, we argue hoping to persuade the authorities in any country that the available newborn screening for CF is the cost benefit procedure in preventing life treating consequences with the obvious impact on the long-term prognosis of this chronic disease.


2014 ◽  
Vol 8 (5) ◽  
pp. 45
Author(s):  
Ali Khraiwish Dalabeeh ◽  
Eng.Hani Hasan Saleh Al-Hajbi

This study presents a comprehensive procedure for evaluating the reliability indices incorporating reduction in interruption cost, and to relate reliability investments with customer’s benefits. An analytical algorithm is used to obtain the final optimal operational solution by determining unit commitment for each generating unit to reach the maximum profit (minimizing cost) subjected to operational constraints. The paper describes a method based on the complementing short-term planning with long-term planning take into account the cost benefit approach. The proposed method has been demonstrated on the RBTS to show the feasibility and the economic effect of the proposed method, and was applied to the Jordanian Electric Power System (JEPS) to show its application capability.


Author(s):  
Marijke Keus Van De Poll ◽  
Gunnar Bergström ◽  
Irene Jensen ◽  
Lotta Nybergh ◽  
Lydia Kwak ◽  
...  

The cost-benefit and cost-effectiveness of a work-directed intervention implemented by the occupational health service (OHS) for employees with common mental disorders (CMD) or stress related problems at work were investigated. The economic evaluation was conducted in a two-armed clustered RCT. Employees received either a problem-solving based intervention (PSI; n = 41) or care as usual (CAU; n = 59). Both were work-directed interventions. Data regarding sickness absence and production loss at work was gathered during a one-year follow-up. Bootstrap techniques were used to conduct a Cost-Benefit Analysis (CBA) and a Cost-Effectiveness Analysis (CEA) from both an employer and societal perspective. Intervention costs were lower for PSI than CAU. Costs for long-term sickness absence were higher for CAU, whereas costs for short-term sickness absence and production loss at work were higher for PSI. Mainly due to these costs, PSI was not cost-effective from the employer’s perspective. However, PSI was cost-beneficial from a societal perspective. CEA showed that a one-day reduction of long-term sickness absence costed on average €101 for PSI, a cost that primarily was borne by the employer. PSI reduced the socio-economic burden compared to CAU and could be recommended to policy makers. However, reduced long-term sickness absence, i.e., increased work attendance, was accompanied by employees perceiving higher levels of production loss at work and thus increased the cost for employers. This partly explains why an effective intervention was not cost-effective from the employer’s perspective. Hence, additional adjustments and/or support at the workplace might be needed for reducing the loss of production at work.


2022 ◽  
Author(s):  
Marjolein Mens ◽  
Gigi van Rhee ◽  
Femke Schasfoort ◽  
Neeltje Kielen

Abstract. Adaptive policy-making to prepare for current and future drought risks requires an integrated assessment of policy actions and combinations of those under changing conditions. This entails quantification of drought risks, integrating drought probability and socio-economic consequences for all relevant sectors that are potentially impacted by drought. The investment costs of proposed policy actions and strategies (various actions combined) can then be compared with the expected risk reduction to determine the cost-effectiveness. This paper presents a method to quantify drought risk in the Netherlands under changing future conditions and in response to policy actions. It illustrates how to use this information as part of a societal cost-benefit analysis and in building an adaptive long-term strategy. The method has been successfully applied to support decision making on the Netherlands’ national drought risk management strategy as part of the National Delta Program for climate change adaptation.


2013 ◽  
Vol 4 (1) ◽  
pp. 41
Author(s):  
Monica Singhania

This case study aims at comprehensively assessing a decision by XYZ Ltd (name withheld due to confidentiality), New Delhi, on whether to build or to lease a recreation centre for its rank-and-file employees. Based on a cost–benefit analysis, we concluded that the centre should be built since the company would recover its investment within 11 years. Apart from the financial considerations, the recreation centre could be considered a long-term investment in employee morale, as it would lead to a better quality of life for the staff and their families, and is likely to enhance their sense of belonging and improve productivity. To date, what little space there is available for hosting family functions is reserved for the use of the officers, and only officers and their families are invited to most company functions. Thus, the other employees feel neglected by the management. Hiring a community centre external to the organisation for a function would involve spending a lot of money as the company is located in a prime real estate area where the cost of land and rentals is huge, and sometimes even availability is an issue. Most of the staff cannot afford such places and are generally under a lot of stress whenever they have a family function. This, in turn, tends to affect their productivity. 


Author(s):  
Peter Lewis

The British Library launched in 1986 a Catalogue Action Plan to deal with the long-term prospect of declining financial and manpower resources, the absence of growth in the market for its services, an unacceptably large backlog of uncatalogued materials, and a steadily increasing annual output of British publications to be catalogued. The initial phase of the Plan was designed to contain staff costs by reduction and simplification in data content in BNBMARC and other British Library records, predicating their future use primarily in an online (OPAC) environment. It has had significant success for the British Library's aims in the first full year of implementation, but it has raised questions of the cost-benefit in centralized cataloguing services for the library community, in respect both of the costs and sizing of OPAC systems in local libraries and of the necessity of sustaining indefinitely the high cost of adherence to international standards established before OPACs, the CD-ROMs and OSI had changed the technology.


2021 ◽  
Vol 6 (16) ◽  
pp. 230-237
Author(s):  
Murat KAYA

The recovery of an investment is very important in the world of economy. While businesses are preparing long-term projects for investment purposes, basic criteria such as changing economic conditions, risks, cash flows of the project, discount rate to be applied, economic life should be estimated in advance. For this reason, businesses prepare different projects that can provide the same economic conditions for the projects they prepare. In order to compare these projects, a cost-benefit table is prepared and evaluated in terms of their advantages. In line with these values, it is ensured that the most correct project is selected by eliminating each other. In this study, the cost-benefit ratio method was applied to three different projects. For all three projects, 10% annual interest and numerical values between 15 and 60 years of life are given. As a result of the evaluation of the projects, the most suitable project was determined by eliminating each other. Cash flows are calculated based on present and annual equivalents.


1998 ◽  
Vol 76 (8) ◽  
pp. 1431-1440 ◽  
Author(s):  
Jenny Christal ◽  
Hal Whitehead ◽  
Erland Lettevall

Sperm whale (Physeter macrocephalus) photoidentification data spanning 12 years of study around the Galápagos Islands were examined to investigate the size, variability, and stability of social units. Adult females and immature whales of both sexes have two types of associates: "constant companions," which are members of an individual's "stable" social unit, and "casual acquaintances," which are temporarily associating members of different units. We analysed long-term association patterns and calculated that individuals have a mean of 11.3 constant companions. Estimated social unit size ranged from 3 to 24 individuals. Evidence of splitting and merging of units and of transfer of individuals between units is presented. The estimated overall frequency of these unit-membership changes is 6.3% per individual per year. These forms of unit dynamics are rare in species with male dispersal and matrilineally related social groups, and cannot be easily explained in this species. There is considerable variation in unit size (perhaps caused by demographic processes), suggesting that the benefits of remaining in a social unit usually outweigh selection for some optimal unit size. However, the occurrence of merging and transfers suggests that the ecological or social cost/benefit of leaving one's matrilineal unit may sometimes outweigh the cost/benefit of staying.


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