The reproductive cycle in the firetail gudgeon, Hypseleotris galii III. Environmental regulation of vitellogenesis

1974 ◽  
Vol 22 (4) ◽  
pp. 449 ◽  
Author(s):  
NJ Mackay
Keyword(s):  
Environmental Regulation ◽  
Reproductive Cycle ◽  
Gonadotropin Release

Fish were maintained under four combinations of photoperiod and temperature for 10 weeks. Fish maintained at 25C showed extensive vitellogenesis but at 15C vitellogenesis was inhibited and yolky oocytes became atretic. Photoperiod had no effect. The effect of reserpine on vitellogenesis was examined, but no evidence for a reserpine-sensitive central nervous mechanism controlling gonadotropin release was found.

Economic models of Environment monitoring under imperfect information and high Costs

2014 ◽  
pp. 99-122
Author(s):  
M. Levin ◽  
K. Matrosova
Keyword(s):  
Environmental Monitoring ◽  
Environmental Regulation ◽  
Environmental Economics ◽  
Imperfect Information ◽  
Central Element ◽  
Economic Models ◽  
Environment Monitoring ◽  
Nature Protection ◽  
Protection Measures ◽  
Effective System

The paper considers monitoring of environmental change as the central element of environmental regulation. Monitoring, as each kind of principalagent relations, easily gives rise to corruptive behavior. In the paper we analyze economic models of environmental monitoring with high costs, incomplete information and corruption. These models should be the elements of environmental economics and are needed to create an effective system of nature protection measures.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

Mechanisms underlying pituitary microvascular remodelling in thoroughbred horses during the annual reproductive cycle

2014 ◽  
Author(s):  
Angus Yeomans ◽  
Nichol Thompson ◽  
Jennifer Castle-Miller ◽  
David O Bates ◽  
Domingo Tortonese
Keyword(s):  
Reproductive Cycle ◽  
Annual Reproductive Cycle ◽  
Thoroughbred Horses

Impacts of Environmental Regulation on Sustainable Economic Growth

2018 ◽  
Vol 9 (9) ◽  
pp. 749-773
Author(s):  
Jonathan Fisher
Keyword(s):  
Economic Growth ◽  
Environmental Regulation ◽  
Technical Change ◽  
Best Practice ◽  
Environmental Regulations ◽  
The European Union ◽  
Porter Hypothesis ◽  
The United Kingdom ◽  
Environment Agency ◽  
Sustainable Economic Growth

There is considerable concern and debate about the economic impacts of environmental regulations. Jonathan Fisher, former Economics Manager at the Environment Agency in England and Wales, reviews the available evidence on this subject. Section 2 presents estimates of the costs and benefits of environmental regulations. Section 3 examines the impacts of environmental regulations on economic growth, innovation and technical change as well as impacts on competitiveness and any movement of businesses to less pollution havens. He questions call for greater certainty regarding future environmental regulations, whereas in fact there should be calls for less uncertainty. This section then suggests how this could be achieved. This section then finishes with an overview of the available evidence. This includes an examination of the Porter Hypothesis that environmental regulations can trigger greater innovation that may partially or more than fully offset the compliance costs. Section 4 then sets out principles for how better environmental regulation can improve its impacts on sustainable economic growth and illustrates how the European Union (EU) Water Framework Directive is a good example of the application of these principles in practice. Section 5 reviews current and recent political perspectives regarding developments in environmental regulations across the EU and shows how the United Kingdom (UK) has successfully positively managed to influence such developments so that EU environmental regulations now incorporate many of these principles to improve their impacts on economic growth. Section 5.1 then examines the implications of Brexit for UK environmental regulations. Finally, Section 6 sets out some best practice principles to improve the impacts of environmental regulation on sustainable economic growth, innovation and technical change.

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