2019-07-01_Discover

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Building Blocks

No (Dark) Matter

Back in 2018, a Yale University-led

team put out a paper claiming that

a galaxy called NGC 1052-DF

was essentially void of matter’s

elusive counterpart, dark matter.

Because dark matter is supposed

to constitute most of the universe,

some experts were skeptical that

this galaxy had virtually none of

it, especially since the 2018 work

hung its claim on just a handful of

data points. But in a recent study, the Yale team backed up their

2018 announcement with more robust data. As an added bonus,

the group published a second paper announcing another galaxy

with little to no dark matter. The works add to the ongoing debate

over what exactly dark matter is and its role in the universe.

A Swing and a Miss

Diversity training is increasingly

popping up in offices across

the world. It’s meant to help

shift prejudicial attitudes and

reduce workplace discrimination.

However, a study in the

Proceedings of the National

Academy of Sciences concluded

that, at least in America, the

training doesn’t have the desired

effect. The researchers found

that when workers volunteered to participate in online programs

meant to alter behaviors toward women and racial minorities,

most people’s attitudes changed to some degree. However, only

women and racial minorities, the groups most likely to experience

prejudice and discrimination, actually altered their behavior. The

experiment lays some basic groundwork that will hopefully lead to

improvements in these programs.

Won’t Somebody Please

Think of the Turtles?

In the past decade, alarming mass

die-offs have hit sea turtle popula-

tions in the Great Barrier Reef,

specifically the endangered green

turtle species — and no one could

figure out why. A recent paper in

Science of the Total Environment

proposes a potential answer.

Researchers studied green turtles

from three regions — two coastal

sites likely to be impacted by

human activity and a more pristine offshore site — from 2014 to

2017. They found that metal contaminants, namely cobalt, were

present in populations with unusually high numbers of sick

turtles. Though they’re unsure of the pollutants’ source, the group

speculates human activity is likely a culprit. The group hopes the

findings can help inform future conservation efforts aimed toward

green turtle populations.

Thanks to advances in big data, health experts and

researchers can glean genetic insights from large populations

of people. To do this, they conduct what are called genome-

wide association studies (GWAS). GWAS rely on databases

that house huge amounts of information. However, most of

the information in these databases comes from people of

European ancestry — a feature that doesn’t translate well if

you’re studying other populations.

Researchers from the Broad Institute of MIT and Harvard

and Massachusetts General Hospital demonstrated this

phenomenon in a recent paper in Nature Genetics. The team

analyzed information from one of the largest publicly available

genetic data sets, the UK Biobank. Specifically, they looked

at polygenic scores, which can predict someone’s risk for

developing conditions like breast cancer or Type 2 diabetes.

They found that the scores had a higher prediction accuracy

for people of European descent than those of African, Asian

or Hispanic/Latino backgrounds. This find, the authors say,

highlights the importance of increasing the genetic diversity

of these databases.

The Power of

Representation

Source: “Clinical use of current polygenic risk scores may exacerbate health disparities,”

Nature Genetics, 2019

Ancestry of GWAS Participants Over Time,

Compared With the Global Population

Prediction Accuracy of UK Biobank’s Polygenic Scores

(Relative to European Ancestry Individuals)

POPULATION

European

East Asian

South Asian/other Asian

African

Hispanic/Latino

Greater Middle Eastern

Oceanic

Other

Multiple

EUROPEAN AMERICAN SOUTH ASIAN EAST ASIAN AFRICAN

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BY LACY SCHLEY

THE CRUX