Long-term exposure to a synthetic estrogen at levels below those currently found in the environment may have a major impact on fish populations, according to a study accepted today for publication in the December issue of the peer-reviewed journal Environmental Health Perspectives (EHP). The study shows that ethynylestradiol, a potent form of estrogen used in oral contraceptives, can produce sexually compromised males.
Researchers exposed zebrafish to low concentrations of the hormone over three generations and measured the effects. After 210 days, or a full zebrafish lifetime of exposure to ethynylestradiol, second-generation fish showed reduced fertility. In addition, out of nearly 12,000 eggs spawned, none were viable. Upon examination, researchers found that none of the second-generation male fish had normal testes, and they did not produce expressible semen. However, the fish showed normal reproductive behavior patterns, including competing with healthy males.
This research suggests that the development of the testes is more sensitive to disruption by ethynylestradiol than is reproductive behavior. This could have significant population-level consequences, as infertile males have a significant ability to interfere with breeding dynamics. “Previous studies in fish have shown that endocrine disruptors can reduce sperm counts and induce female-specific proteins in males,” said Dr. Jim Burkhart, science editor for EHP. “But until now little evidence existed to show that environmentally relevant concentrations of endocrine disruptors could induce such changes and actually reduce fertility.”
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine