One shot of an experimental gene therapy kept female cats kitten-free for at least two years, Erin Garcia de Jesús reported in “Gene therapy prevents cat pregnancy” (SN: 7/15/23 & 7/29/23, p. 10).
It only takes one “pesky” male cat to impregnate multiple females, says reproductive biologist David Pépin of Massachusetts General Hospital and Harvard Medical School. If male contraceptives alone were used, nearly every male cat would need to receive treatment to prevent pregnancies in females. But each female cat that receives contraception is one less female giving birth to litters, regardless of the male population, Pépin says. What’s more, surgical sterilization is a more invasive procedure for female cats than it is for males, which makes females an ideal target for quick and easy birth control, he says.
With that said, contraception for both male and female cats would be helpful for controlling populations of feral cats, Pépin says. Researchers are developing new birth control methods for male cats, but none have proved permanent.
The North Pole drifted about 1.6 meters toward the east coast of Greenland between 1993 and 2010. About 78 centimeters, or about 4.4 cm per year, of that shift was due to irrigation alone, Sid Perkins reported in “Irrigation nudges the North Pole” (SN: 7/15/23 & 7/29/23, p. 12).
2023-09-03 06:15:00
Source from www.sciencenews.org
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