source: https://www.nature.com/articles/d41586-018-00927-4

Jeff Tollefson

For the first time, China has overtaken the United States in terms of the total number of science publications, according to statistics compiled by the US National Science Foundation (NSF).

The agency’s report, released on 18 January, documents the United States’ increasing competition from China and other developing countries that are stepping up their investments in science and technology. Nonetheless, the report suggests that the United States remains a scientific powerhouse, pumping out high-profile research, attracting international students and translating science into valuable intellectual property.

“The US continues to be the global leader in science and technology, but the world is changing,” says Maria Zuber, a geophysicist at the Massachusetts Institute of Technology in Cambridge. As other nations increase their output, the United States’ relative share of global science activity is declining, says Zuber, who chairs the National Science Board, which oversees the NSF and produced the report. “We can’t be asleep at the wheel.”

The shifting landscape is already evident in terms of the sheer volume of publications: China published more than 426,000 studies in 2016, or 18.6% of the total documented in Elsevier’s Scopus database. That compares with nearly 409,000 by the United States. India surpassed Japan, and the rest of the developing world continued its upward trend.

But the picture was very different when researchers examined where the most highly cited publications came from. The United States ranked third, below Sweden and Switzerland; the European Union came in fourth and China fifth. The United States still produces the most doctoral graduates in science and technology, and remains the primary destination for international students seeking advanced degrees — although its share of such students fell from 25% in 2000 to 19% in 2014, the report says.

The United States spent the most on research and development (R&D) — around US$500 billion in 2015, or 26% of the global total. China came in second, at roughly $400 billion. But US spending remained flat as a share of the country’s economy, whereas China has increased its R&D spending, proportionally, in recent years.

📷Credit: National Science Foundation

The NSF analysis, the latest edition of the agency’s biennial Science and Engineering Indicators, comes at a time of heightened concern about the state of US science. It should raise some alarms, says Mark Muro, a senior fellow with the Brookings Institution, a think tank in Washington DC. Trends in US science spending are heading in the wrong direction, he says, and the talent pool of researchers continues to be limited by under-representation of women and minorities. Similarly, key industries such as semiconductors have been hollowed out as businesses ship production work to other countries, Muro adds.

For the first time, the NSF included a section on technology transfer and innovation in its statistical analysis. Data suggest that the United States continues to lead the world when it comes to things like patents, revenue from intellectual property and venture capital funding for innovative technologies. Although more focus is needed at the local and regional level, Muro says, the report nonetheless provides important data about the value of scientific innovation.

“A nation’s innovation capacity is one of the main drivers of productivity growth and so prosperity,” Muro says. The new data provide “a useful reminder of why we care about these indicators in the first place.”

More than 100 genes have been discovered to be associated with osteoporosis and bone fracture. Although the effects of individual genes are relatively small, their effects en mass in the form of a “genetic signature” can help in the personalised assessment of fracture risk.

Bone fracture is a serious consequence of osteoporosis. The lifetime risk of a hip fracture for 50-year old women is about 15%, which is equivalent to that of invasive breast cancer. Almost 20% of patients with a hip fracture die within 12 months after the event. However, it is not just hip fractures that impose a great mortality and morbidity burden on both patients and the society; non-hip fractures are also associated with increased risk of mortality.

Osteoporosis and bone fractures represent one of the most challenging public problems in Australia. The challenge for both research and public health policy lies in the identification of high-risk asymptomatic individuals. Over the past 30 years, studies from our group and others have provided an important clue to the pathogenesis of osteoporotic fractures: bone strength. People sustain a bone fracture because their bone is not strong enough to bear a force exerted against it. Bone mineral density (BMD) is currently the best measure of bone strength, and people with low BMD (i.e., osteoporosis) are at significantly greater risk of fracture than people with normal or only slightly reduced BMD. Therefore, efforts to identify individuals at high risk of fracture have focused largely on factors that are associated with BMD.

Doctors and scientists have long known that the between-individuals variation in BMD is due largely to genetic factors. Studies in twins and families have found that up to 80% of differences in BMD between us are attributable to heritable factors. The risk of hip fracture in women whose mothers have sustained a hip fracture is more than 2-fold higher than women whose mothers have not had a hip fracture, because they have a deficit in bone strength. Taken together, the evidence for genetic influences on bone strength and fracture are overwhelming.

Still, it remains a great challenge to find specific genes (in the pool of millions of genetic variants in our body) that are associated with BMD — a task that is likened to finding needles in the haystack! Nevertheless, with advances in genetics and bioinformatics, after almost two decades of “gene hunting”, we and others have identified more than 60 variants associated with BMD. A more recent study based on ~142,000 individuals from the UK Biobank found 307 genetic variants that are associated with another measure of bone strength called quantitative ultrasound measurement of the heel. While these findings represent a triumph of science and technology, a small twist is that these variants explained only 10-12% of differences in BMD between individuals.

With such a small proportion of variance explained, one may ask: how can GPs utilise genes for the identification of high-risk individuals in the general community? Individually, the variants identified have little clinical utility because they have very small effects on individual fracture risk, but collectively they can be of help. One way to pull the effects of genetic variants en masse is to generate a genetic signature for each individual, which can be used in the assessment of bone health. We have created such a signature — termed as “osteogenomic profile” — and found that it predicts the risk of fracture independently of age and clinical risk factors. We have recently found that the osteogenomic profile can also help assess bone loss in elderly people. Although we are excited about these findings, it is important to emphasize that the profile is not yet ready for use in the clinic. Nevertheless, the recent findings do, however, bring us a huge step closer to a more accurate personalised fracture risk assessment.