scholarly journals Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimating the Impact?

2006 ◽  
Vol 114 (Suppl 1) ◽  
pp. 40-50 ◽  
Author(s):  
Tyrone B. Hayes ◽  
Paola Case ◽  
Sarah Chui ◽  
Duc Chung ◽  
Cathryn Haeffele ◽  
...  
Keyword(s):  
Endocrine Disruption ◽  
Amphibian Declines ◽  
Pesticide Mixtures ◽  
The Impact

Virulence and Pathogenicity of Chytrid Fungi Causing Amphibian Extinctions

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Matthew C. Fisher ◽  
Frank Pasmans ◽  
An Martel
Keyword(s):  
Online Publication ◽  
Abiotic Factors ◽  
Amphibian Declines ◽  
Host Responses ◽  
Annual Review ◽  
Publication Date ◽  
Emerging Infections ◽  
Biological Methods ◽  
The Impact ◽  
Highly Virulent

Ancient enzootic associations between wildlife and their infections allow evolution to innovate mechanisms of pathogenicity that are counterbalanced by host responses. However, erosion of barriers to pathogen dispersal by globalization leads to the infection of hosts that have not evolved effective resistance and the emergence of highly virulent infections. Global amphibian declines driven by the rise of chytrid fungi and chytridiomycosis are emblematic of emerging infections. Here, we review how modern biological methods have been used to understand the adaptations and counteradaptations that these fungi and their amphibian hosts have evolved. We explore the interplay of biotic and abiotic factors that modify the virulence of these infections and dissect the complexity of this disease system. We highlight progress that has led to insights into how we might in the future lessen the impact of these emerging infections. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals The Impact of Endocrine Disruption: A Consensus Statement on the State of the Science

2013 ◽  
Vol 121 (4) ◽  
Author(s):  
Åke Bergman ◽  
Jerrold J. Heindel ◽  
Tim Kasten ◽  
Karen A. Kidd ◽  
Susan Jobling ◽  
...  
Keyword(s):  
Endocrine Disruption ◽  
Consensus Statement ◽  
The State ◽  
State Of The Science ◽  
The Impact

scholarly journals Endocrine disruption in wildlife: The future?

2003 ◽  
Vol 75 (11-12) ◽  
pp. 2355-2360 ◽  
Author(s):  
J. P. Sumpter
Keyword(s):  
Endocrine Disruption ◽  
Sewage Treatment ◽  
Population Level ◽  
Paper Mill ◽  
Individual Organism ◽  
Paper Mill Effluent ◽  
The Future ◽  
Over Exploitation ◽  
The Individual ◽  
The Impact

Probably the only thing that can be said with certainty about the future of this field of ecotoxicology is that predicting it is foolish; the chances of being right are very slim. Instead, it seems to me likely that unexpected discoveries will probably have more influence on the field of endocrine disruption than the outcomes of all the planned experiments. It is certainly true that chance discoveries, such as masculinized fish in rivers receiving paper-mill effluent, imposex in molluscs due to exposure to tributyltin and feminized fish in rivers receiving effluent from sewage-treatment works, have been pivotal in the development of the field of endocrine disruption in wildlife. I consider that further such discoveries are likely, but I do not know which species will be affected, what effects will be found, what chemical(s) will be the cause, or what endocrine mechanism(s) will underlie the effects. The recent realization that many pharmaceuticals are present in the aquatic environment only underscores the range of effects that could, in theory at least, occur in exposed wildlife. What is somewhat easier to predict is the research that will be conducted in the immediate future, which will build upon what is known already. For example, it is clear that wildlife is rarely, if ever, exposed to single chemicals, but instead is exposed to highly complex, ill-defined mixtures of chemicals, including many that are endocrine active in various ways. We need to understand much better how chemicals interact, and what overall effects will occur upon exposure to such mixtures. We also need to move from assessing effects at the individual organism level, to understanding the consequences of these effects at the population level. Then, we need to determine the significance of any population-level effects due to endocrine disruption in comparison with the impact of many other significant stressors (e.g., over-exploitation, habitat loss, climate change) that also negatively impact wildlife. Such research will be difficult, and time-consuming, and will probably produce many surprises. All I can be fairly certain about is that the next few years are likely to be as interesting and exciting as the last few have been.

scholarly journals Early-life exposure to a herbicide has enduring effects on pathogen-induced mortality

2013 ◽  
Vol 280 (1772) ◽  
pp. 20131502 ◽  
Author(s):  
Jason R. Rohr ◽  
Thomas R. Raffel ◽  
Neal T. Halstead ◽  
Taegan A. McMahon ◽  
Steve A. Johnson ◽  
...  
Keyword(s):  
Early Life ◽  
Disease Susceptibility ◽  
Developmental Stages ◽  
Cost Effective ◽  
Amphibian Declines ◽  
Early Life Exposure ◽  
Risk Of Mortality ◽  
Fungal Load ◽  
Herbicide Atrazine ◽  
The Impact

Exposure to stressors at formative stages in the development of wildlife and humans can have enduring effects on health. Understanding which, when and how stressors cause enduring health effects is crucial because these stressors might then be avoided or mitigated during formative stages to prevent lasting increases in disease susceptibility. Nevertheless, the impact of early-life exposure to stressors on the ability of hosts to resist and tolerate infections has yet to be thoroughly investigated. Here, we show that early-life, 6-day exposure to the herbicide atrazine (mean ± s.e.: 65.9±3.48 µg l −1 ) increased frog mortality 46 days after atrazine exposure (post-metamorphosis), but only when frogs were challenged with a chytrid fungus implicated in global amphibian declines. Previous atrazine exposure did not affect resistance of infection (fungal load). Rather, early-life exposure to atrazine altered growth and development, which resulted in exposure to chytrid at more susceptible developmental stages and sizes, and reduced tolerance of infection, elevating mortality risk at an equivalent fungal burden to frogs unexposed to atrazine. Moreover, there was no evidence of recovery from atrazine exposure. Hence, reducing early-life exposure of amphibians to atrazine could reduce lasting increases in the risk of mortality from a disease associated with worldwide amphibian declines. More generally, these findings highlight that a better understanding of how stressors cause enduring effects on disease susceptibility could facilitate disease prevention in wildlife and humans, an approach that is often more cost-effective and efficient than reactive medicine.

scholarly journals Eutrophic status influences the impact of pesticide mixtures and predation on Daphnia pulex populations

2021 ◽  
Author(s):  
Talles Bruno Oliveira dos Anjos ◽  
Francesco Polazzo ◽  
Alba Arenas‐Sánchez ◽  
Laura Cherta ◽  
Roberto Ascari ◽  
...  
Keyword(s):  
Daphnia Pulex ◽  
Pesticide Mixtures ◽  
The Impact

scholarly journals Do pathogens become more virulent as they spread? Evidence from the amphibian declines in Central America

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131290 ◽  
Author(s):  
Ben L. Phillips ◽  
Robert Puschendorf
Keyword(s):  
Central America ◽  
Population Decline ◽  
Rapid Evolution ◽  
Amphibian Declines ◽  
Environmental Drivers ◽  
Strong Impact ◽  
Spatial Effects ◽  
Southern Mexico ◽  
Amphibian Population ◽  
The Impact

The virulence of a pathogen can vary strongly through time. While cyclical variation in virulence is regularly observed, directional shifts in virulence are less commonly observed and are typically associated with decreasing virulence of biological control agents through coevolution. It is increasingly appreciated, however, that spatial effects can lead to evolutionary trajectories that differ from standard expectations. One such possibility is that, as a pathogen spreads through a naive host population, its virulence increases on the invasion front. In Central America, there is compelling evidence for the recent spread of pathogenic Batrachochytrium dendrobatidis (Bd) and for its strong impact on amphibian populations. Here, we re-examine data on Bd prevalence and amphibian population decline across 13 sites from southern Mexico through Central America, and show that, in the initial phases of the Bd invasion, amphibian population decline lagged approximately 9 years behind the arrival of the pathogen, but that this lag diminished markedly over time. In total, our analysis suggests an increase in Bd virulence as it spread southwards, a pattern consistent with rapid evolution of increased virulence on Bd's invading front. The impact of Bd on amphibians might therefore be driven by rapid evolution in addition to more proximate environmental drivers.

Status of Conservation and Decline of Amphibians

2018 ◽  
Keyword(s):  
Environmental Changes ◽  
Current Knowledge ◽  
Conservation Status ◽  
Warning System ◽  
Amphibian Declines ◽  
Current Conservation ◽  
The Pacific ◽  
Challenges And Opportunities ◽  
The Status ◽  
The Impact

Amphibians are among the most threatened groups of animals on earth. In part due to their highly permeable skin, amphibians are highly sensitive to environmental changes and pollution and provide an early-warning system of deteriorating environmental conditions. The more we learn about the impact of environmental changes on amphibians, the better we as humans will be able to arrest their demise, and our own. Status of Conservation and Decline of Amphibians brings together the current knowledge on the status of the unique frogs of Australia, New Zealand, and the Pacific. Although geographically proximate, each region presents unique challenges and opportunities in amphibian research and conservation. This book contributes to an understanding of the current conservation status of the amphibians of each region, aims to stimulate research into halting amphibian declines, and provides a better foundation for making conservation decisions. It is an invaluable reference for environmental and governmental agencies, researchers, policy-makers involved with biodiversity conservation, and the interested public.

Receptor and Enzyme Mechanisms as Targets for Endocrine Disruptors

2017 ◽  
Author(s):  
Heather B. Patisaul ◽  
Scott M. Belcher
Keyword(s):  
Nervous System ◽  
Steroid Hormones ◽  
Endocrine Disruptors ◽  
Endocrine Disruption ◽  
Hormone Receptors ◽  
Mammalian Brain ◽  
Mechanistic Studies ◽  
Rapid Signaling ◽  
The Impact ◽  
The Brain

In this chapter, the current understanding of the mechanisms of endocrine disruption on the brain and nervous system are presented. Because the overwhelming majority of mechanistic studies on EDCs have focused on the actions mediated by nuclear hormone receptors, this mechanisms is described in detail. The chapter also discusses the classic transcriptional mechanisms of steroid action and the impact of EDCs on rapid signaling (non-genomic) mechanisms. It presents an overview of the enzymes and pathways involved in the biosynthesis of steroid hormones, which are critical to proper functioning of the HPA and HPG axis, and the neuroactive steroids synthesized and active in the mammalian brain. The potential for EDCs to alter metabolic enzymes, with a focus on possible targets in the metabolic blood-brain barrier, is presented as a potential, though largely unexplored, mode of EDC action in the brain.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Sign in / Sign up

Export Citation Format

Share Document