20 NEWS Health & Science
Salad for the Red Planet
Good news for aspiring Mars explorers:
You’ll be able to grow and munch fresh
lettuce during your voyage through space.
At the moment, most of the food that astro-
nauts eat on the International Space Station
(ISS) is prepared on Earth and sent up in
cargo rockets. But during a mission to Mars
such resupply flights won’t be possible,
and in the three years it will take to make
a round trip, Earth-grown produce stored
on board will lose some of its nutrients and
taste. Previous efforts to grow vegetables
in space have been stymied by zero grav-
ity; water sticks to the leaves, for example,
rather than dropping down to the roots. But
a new analysis of lettuce grown in Veggie,
a plant chamber used on the ISS between
2014 and 2016, has found it is as health-
ful as the stuff grown on terra firma. “This
was really good,” co-author Gioia Massa,
a NASA plant scientist, tells The New York
Times. “There wasn’t anything completely
surprising or crazy or weird.” Veggie uses
porous ceramic clay to trap water and air
around the plant’s roots. One problem it
hasn’t solved is how to wash the produce:
When ISS astronauts ate their harvest, they
cleaned the leaves with sanitizing wipes.
Low-carb diet good for brain
Eating fewer carbohydrates might prevent
and could even reverse age-related dam-
age to the brain, reports The Guardian
(U.K.). Researchers examined brain scans
of nearly 1,000 people, ages 18 to 88, and
found that the rate of damage to neural
pathways varied depending on the brain’s
main source of energy. Glucose, the sugar
broken down from carbohydrates, acceler-
ated the damage; ketones, produced by
the liver during low-carb diets, slowed it
down. The researchers also found that
people can start experiencing damage in
their neural pathways as early as their
late 40s. “The bad news is that we see
the first signs of brain aging much earlier
than was previously thought,” says lead
author Lilianne Mujica-Parodi, from Stony
Brook University in New York. “The good
news is that we may be able to prevent or
reverse these effects with diet.” A high-
ketone diet is low in carbohydrates and
high in fats and proteins; further research
is needed to determine whether the pos-
sible neurological benefits of such a diet
outweigh its impact on heart health.Dinosaur days were shorter
When dinosaurs walked the earth, days were
about half an hour shorter than they are
now, reports USA Today. That’s the conclu-
sion of a new study into a 70 million–year-
old fossil of a mollusk shell, below. The mol-
lusk, which lived for about nine years on a
shallow seabed in what is now Oman, grew
fast and is thought to have produced daily
growth rings. Using lasers to sample
tiny slivers of its shell,
scientists were able to
count these growth
rings. “We have
about four to
five data points
per day, and
this is some-
thing that you
almost never get
in geological his-tory,” says lead author Niels de Winter,
from Vrije Universiteit in Brussels. “We can
basically look at a day 70 million years ago.
It’s pretty amazing.” From their analysis, de
Winter and his team concluded that days
lasted about 23 hours and 30 minutes in
the Cretaceous period. Earth turned faster
then than it does today, clocking up to 372
rotations a year rather than 365; over time,
friction from ocean tides—which are driven
by the gravity of the moon—has steadily
slowed the planet’s rotation.Health scare of the week
Anxiety and bad-sleeping babies
Babies who are poor sleepers may be at
greater risk of developing anxiety and
emotional issues later in childhood. In a
decade-long study, Australian researchers
tracked 1,507 first-time mothers and their
children, reports CNN.com. Each mother
recorded her baby’s sleeping pattern every
three months for the first year after birth,
and then answered questions about the
child’s mental health at 4 and 10 years of
age. During their first year, 20 percent of
the children had “persistent severe sleep
problems”—waking up multiple times dur-
ing the night and struggling to settle back
down. Compared with the children who
slept well as infants, these poor sleepers
were almost three times more likely to show
signs of emotional difficulties at age 4, and
twice as likely by age 10. The emotional
issues included separation anxiety,
fear of physical injury, and
elevated anxiety. “These results
may mean that sleep issues
result in later problems,”
says Jodi Mindell from
the Children’s Hospital
of Philadelphia, who
wasn’t involved in the
study. “But it is just as
likely that sleep problems
are an early indicator.” Reuters, NASA, WikipediaScientists in China believe they have
identified two unique strains of the
new coronavirus—a discovery that, if
confirmed, could mean new variants
will crop up year after year in the same
way as seasonal flu. Researchers from
Peking University examined the genetic
sequences of viral samples from 103
Chinese Covid-19 patients. They say they
found two forms of the virus: “L-type”
and “S-type.” The L-type was more
prevalent among those who had the
disease early in the outbreak; the S-type
was more common in later samples.
Counterintuitively, it appeared that theformer was derived from the latter.
Researchers think the S-type didn’t make
as big an impact initially because it isn’t
as virulent. The differences between the
two are tiny; they both carry the same
symptoms and are equally deadly. But
if there are indeed two strains, it’s safe
to assume that more will emerge in the
months and years ahead. That’s how
seasonal flu works: New variants crop up
as viruses mutate to overcome people’s
immune systems. Some scientists have
questioned the finding, noting that the
study is based on a small sample and
that such mutations don’t make the virusbehave differently. But others say the
research shows that the coronavirus will
be with us for years to come. Ian Jones,
from Reading University in the U.K., tells
New Scientist: “I don’t see it going away
any time soon.”Are there multiple strains of Covid-19?
Harvesting the space lettuce on the ISSThe coronavirus could become seasonal.