White House takes aim at antibiotic resistance

Antibiotic use in agriculture all began in 1948 when a biochemist found chickens fed a new antibiotic were growing faster than those without. [Credit: iStock]

Antibiotic use in agriculture all began in 1948 when a biochemist found chickens fed a new antibiotic were growing faster than those without. [Credit: iStock]

The Obama administration has announced a range of measures to combat antibiotic resistance that threatens to render much of our arsenal of drugs useless in the face of disease.

Already more than 20,000 lives are lost every year because bacteria have become resistance to available antibiotics. Nowhere is the problem more acute than with the scourge of TB around the world.

This is a “top national security and public health priority”, says John Holdren, director of the White House Office of Science and Technology Policy.

The strategy to control the problem will include the development of new drugs, better control of the use of existing treatments, and improved monitoring processes.

Cheaper and more efficient genome-sequencing technology will be a key tool as it helps scientists get a better idea of how infections develop and – a crucial question –  how antibiotic use on livestock is adding to the problem of resistance.

"Genetic differences between bacteria can be used to sketch out a molecular 'family tree', which would allow researchers to trace an outbreak and scour it for telltale similarities or differences," the report says.
"With traditional methods of characterizing antibiotic-resistant bacteria, it was difficult to answer these questions. In the past few years, however, advances in rapid and inexpensive DNA-sequencing technology have made it possible to extract answers from bacterial genomes."

According to the New York Times, Americans use more antibiotics than people in other industrialised nations...

...with rates more than twice those in Germany and the Netherlands, according to the Pew Charitable Trusts, a Washington-based research and advocacy group. The United States also uses far more antibiotics in livestock than many other nations; animals raised for food in America are given about six times as much antibiotics as are animals in Norway and Denmark.

Cosmos highlighted the issue of antibiotic use in livestock a few months back when we investigated how these drugs got into the food chain and what affect they are having.

They were introduced by Thomas H. Jukes, a distinguished professor at the University of California at Berkeley and a pioneer in the new science of molecular biology. Before that, though, he had worked in the pharmaceutical industry for Lederle, where he discovered in 1948 that chickens fed a new antibiotic were growing faster than those without. 

Jukes was very much a man of his time when there was a wider belief that science could solve all ills.

Thomas Jukes, formed his ideas in an age of medical miracles, and firmly believed in the power of science to conquer sickness and hunger. [Credit: UC Berkeley].

Thomas Jukes, formed his ideas in an age of medical miracles, and firmly believed in the power of science to conquer sickness and hunger. [Credit: UC Berkeley].

Jukes formed his ideas in an age of medical miracles, and firmly believed in the power of science to conquer sickness and hunger. So he also defended the use of DDT against malaria, even calling attempts to ban the insecticide “unquestionably genocidal”. When the prescription drug DES, or diethylstilbestrol, became notorious in the 1970s for causing birth defects and cancers in young women, Jukes argued for its continued use as a growth promoter in cattle, saying the risk to consumers was minuscule...

Now antibiotics are so widely used, and vested interests so powerful any reduction of their use will be hard to achieve.

The food industry has long argued that any limit on use of antibiotics in livestock feed would be an agricultural disaster, or at least the end of affordable meat. But critics are applying increasing pressure on the industry to address its share of the blame for an epidemic of antibiotic-resistant infections that kills hundreds of thousands of people worldwide each year.  

Perhaps the White House's new aggressive strategy – the first of its kind – will tip the scales towards the critics' arguments. But even if it does, it will be a long and bruising fight.

The science of piracy

Today is apparently International Talk Like a Pirate Day (No, we don't know why, either).

RiAus has used it as an excuse to look at the science and technology an old school pirate would use every day.

Navigational instruments like the backstaff, nocturnal and sextant, how to measure your speed in knots, explosives for cannonballs, scurvy and other health issues are all covered, with more on the RiAus website.

Fat? Unfit? Sick? We can still launch you into space

The 20 G centrifuge at the NASA Ames Research Center. But doctors say most people could take the stress. [Credit: NASA]

The 20 G centrifuge at the NASA Ames Research Center. But doctors say most people could take the stress. [Credit: NASA]

Doctors say that almost anyone can join a commercial spaceflight, traditionally the preserve of the super fit astronaut.

In fact it is hard to find a disorder or condition that rules you out.

People with common medical problems — high blood pressure, heart disease, diabetes, lung diseases like asthma or emphysema and back and neck injuries, surgeries or disorders — would be able to tolerate the stresses of commercial spaceflight, the aerospace medicine group at the University of Texas Medical Branch at Galveston says, after studying how average people would cope.

The key seems to be that, whatever your medical condition, it is well-controlled. " Lead author Dr. Rebecca Blue explains:

Physiological stresses of flight include increased acceleration forces, or 'G-forces,' during launch and re-entry, as well as the microgravity period. Our goal was to see how average people with common medical problems, who aren't necessarily as fit as a career astronaut, would be able to tolerate these stresses of an anticipated commercial spaceflight.

The researchers made their findings by putting people with a range of conditions through centrifuge simulations of spaceflight launch and re-entry and studying how they performed.

They do not say how they got that one past their insurance company.

The report was published in the journal Aviation, Space and Environmental Medicine

So what happened to the super El Niño we were promised?

Normally, winds across the Pacific flow east to west, with cold water dominating the eastern Pacific. [Credit: NOAA/Wikimedia]

Normally, winds across the Pacific flow east to west, with cold water dominating the eastern Pacific. [Credit: NOAA/Wikimedia]

In May, Michael Slezak in New Scientist was warning of wild weather for the year ahead thanks to an impending major El Niño event.

During an El Niño, warm water spreads right across the Pacific Ocean, and the winds reverse.  [Credit: NOAA/Wikimedia]

During an El Niño, warm water spreads right across the Pacific Ocean, and the winds reverse.  [Credit: NOAA/Wikimedia]

The weather is preparing to go wild, and will wreak havoc and death around the globe later this year. An El Niño, a splurge of warm water in the Pacific Ocean, is coming. It will unleash floods in the Americas, while South-East Asia and Australia face drought. Yet little is being done to address these consequences.

The weather pattern occurs when warm water spreads eastwards from Indonesia and rises to the surface of the Pacific, taking rain from Asia and Australia and dumping it on the Americas – droughts and wildfires for some, floods and landslides for others.

As Slezak noted, the effects can be deadly.

A big El Niño in 1997-98 killed 20,000 people and caused almost $97 billion of damage.

But so far, nothing (or perhaps that should be "nada" as we're talking El Niño). At least nothing that could be branded a "super El Niño". 

As Agus Santosa notes in the Conversation

The Bureau of Meteorology has brought the odds of an El Niño event down to 50%, from 70%. Even if it hits, most authorities are forecasting a weak to moderate event. Not that this should make seasonal weather watchers any less wary. Even a moderate El Niño can significantly affect Australia’s rainfall.

But Santosa questions whether the betting markets are right. He points out that we have been caught out before by dismissing the chances of a super event.

The second-largest El Niño event on modern record, which hit in 1982/83, developed rather slowly before rapidly picking up in late August.

He points to recent signs that the development of El Niño conditions may be picking up again.

...the July average temperatures are still comparable to 1982. In particular, as you can see, the Southern Oscillation Index has also recently turned negative again — indicating a possible El Niño.

Although not as dramatic as this year, the 1982/83 event also showed a weakening in May to July. The 1982 anomalies then picked up rapidly to deliver the second-strongest El Niño in modern record.

No one knows quite what will happen. The recent changes in temperature make it more likely, but we’ll have to keep watching to know for sure, says Santosa.

 

 

Endangered Chinese sturgeon gives up fight to survive

The Three Gorges dam is just the largest of a succession of dams that have blocked the Chinese sturgeon from its spawning sites. [Credit: iStock]

The Three Gorges dam is just the largest of a succession of dams that have blocked the Chinese sturgeon from its spawning sites. [Credit: iStock]

It looks like we are just counting down the days for the Chinese sturgeon, at least in the wild. It has apparently  given up breeding in the polluted and dammed Yangtze River, its last stronghold.

According to a report by the Chinese Academy of Fishery Sciences, only about 100 of the massive fish remain. The academy found that the sturgeon did not reproduce naturally at all last year and researchers found no evidence of either eggs or juveniles.

John Platt at Scientific American charts the animal's decline.

That’s quite a change from just 50 or 60 years ago, when a healthy sturgeon fishing industry existed on the Yangtze and nearby rivers. But pollution and the construction of dams took a rapid toll. By the late 1970s, the sturgeon population had dropped to an estimated 10,000 adults. The 1980s saw another drop as the Gezhouba Dam cut off the upper Yangtze and blocked the sturgeons’ migratory route. By 1984, the population of spawning adult sturgeon had fallen to under 2,200.
A 3.2m, 280kg Chinese sturgeon  in Heilongjiang Museum. 

A 3.2m, 280kg Chinese sturgeon  in Heilongjiang Museum. 

An adult Chinese sturgeon measures up to 4 metres long, and weighs over 450 kg, making it one the largest sturgeons in the world. 

It is anadromous, which means it spends part of its life in saltwater, returning to rivers to breed.

Young sturgeons live in estuaries of the river and along the shoreline nearby.

A Chinese sturgeon in captivity.

A Chinese sturgeon in captivity.

Sexually mature adults arrive at the mouth of the Yangtze River in June or July to travel up-river to spawn. They reach the middle sections of the river in September or October, where they overwinter.

Before a succession of dams were built along the river, the fish migrated by 2,500 to 3,300 km. Spawning sites often occur in turbulent sections of the river between steep cliffs.

The sturgeon spawn in turbulent water running between steep cliffs, typical of the upper Yangtze. [Credit: iStock]

The sturgeon spawn in turbulent water running between steep cliffs, typical of the upper Yangtze. [Credit: iStock]

Their roe sticks to gravel on the river-bottom until hatching, with the fry travelling down river to coast where they grow and cycle begins again.

The Yangtze is home to at least two other animals that are heading for extinction thanks to the combination of pollution and damming. The World Wildlife Fund says the Yangtze river dolphin population crashed by 99.4% from 1980 to 2006, and that of the Chinese alligator by 97% from 1955 to 2010.

Smallest known galaxy with a supermassive black hole

This Hubble Space telescope image shows the gargantuan galaxy M60 in the center, and the ultracompact dwarf galaxy M60-UCD1 below it and to the right, and also enlarged as an inset. A new international study led by University of Utah astronomer Anil Seth found that M60-UCD1 is the smallest known galaxy with a supermassive black hole at its centre, suggesting the dwarf galaxy originally was much larger but was stripped of its outer layers by gravity from galaxy M60 over billions of years. M60's gravity also is pulling galaxy NGC4647, upper right, and the two eventually will collide. [Credit: NASA/Space Telescope Science Institute/European Space Agency].

Many black holes may hide in dwarf remnants of stripped galaxies, a University of Utah astronomer and his colleagues believe after discovering an ultracompact dwarf galaxy that harbours a supermassive black hole.

If correct, it means black holes may be more common than we thought.

"It is the smallest and lightest object that we know of that has a supermassive black hole," says Anil Seth, lead author of an international study of the dwarf galaxy published today in Nature. "It's also one of the most black hole-dominated galaxies known."

The small galaxy named M60-UCD1 has a black hole with a mass equal to 21 million Suns.

Seth, assistant professor of physics and astronomy at the University of Utah, believes that dwarf galaxies like this may be the stripped remnants of larger galaxies that were torn apart during collisions with yet other galaxies.

"We don't know of any other way you could make a black hole so big in an object this small. There are a lot of similar ultracompact dwarf galaxies, and together they may contain as many supermassive black holes as there are at the centers of normal galaxies."

Black holes are collapsed stars and collections of stars with such strong gravity that even light is pulled into them. Supermassive black holes – those with the mass of at least a million stars like our Sun – are thought to be at the centres of many galaxies.

The central, supermassive black hole at the centre of our Milky Way galaxy – that we discussed in a recent Cosmos issue – has the mass of 4 million Suns. By comparison, the supermassive black hole at the centre of ultracompact dwarf galaxy M60-UCD1 is five times larger than the Milky Way's.

M60-UCD1 is about 54 million light years from Earth, but the dwarf galaxy is only 22,000 light years from the centre of galaxy M60, which "is closer than the sun is to the centre of the Milky Way," Seth says.

The video simulation below, made by one of Seth's co-authors, Holger Baumgardt of the University of Queensland, shows how galaxy M60-UCD1, was formed from a larger, normal galaxy.

The video begins with a background image from the Hubble Space Telescope, with the huge elliptical galaxy M60 in the centre, galaxy NGC4647 in the upper right and MC60-UCD as a small whitish spot lower right.

As the video begins, a normal galaxy (yellow and red) orbits M60. During an estimated 500 million years, M60’s gravity strips stars (red material) from the orbiting galaxy, leaving as a remnant the ultracompact dwarf galaxy now known as M60-UCD1. The end of the video zooms in on the Hubble Space Telescope close-up image of M60-UCD1.

How the Earth's tectonic plates began to move

[Credit: iStock]

[Credit: iStock]

The Earth's tectonic plates began to move thanks to the eruption of continents that pushed them apart, scientists at the University of Sydney believe.

The process has been a mystery until now.

"The geological record suggests that until three billion years ago the earth's crust was immobile so what sparked this unique phenomenon has fascinated geoscientists for decades," says lead author of the study Professor Patrice Rey, from the University of Sydney's School of Geosciences.

"We suggest it was triggered by the spreading of early continents then eventually became a self-sustaining process."

There are eight major tectonic plates that move above the earth's mantle at rates up to 150 millimetres every year.

The process involves plates being dragged into the mantle at certain points and moving away from each other at others, in what has been dubbed "the conveyor belt".

Earth is the only planet in our solar system where the process of plate tectonics occurs and the dynamic was only relatively recently discovered, as Cosmos explained in a recent article.

Plate tectonics depends on the inverse relationship between density of rocks and temperature.

At mid-oceanic ridges, rocks are hot and their density is low, making them buoyant or more able to float. As they move away from those ridges they cool down and their density increases until, where they become denser than the underlying hot mantle, they sink and are 'dragged' under.

But three to four billion years ago, the earth's interior was hotter, volcanic activity was more prominent and tectonic plates did not become cold and dense enough to spontaneously sank.

"So the driving engine for plate tectonics didn't exist," said Professor Rey said.

"Instead, thick and buoyant early continents erupted in the middle of immobile plates. Our modelling shows that these early continents could have placed major stress on the surrounding plates. Because they were buoyant they spread horizontally, forcing adjacent plates to be pushed under at their edges."

 The study was published in Nature today.

The other authors on the paper are Nicolas Flament, also from Sydney's School of Geosciences and Nicolas Coltice, from the University of Lyon.

Boeing and SpaceX winners in NASA Commercial Crew round

A mock-up of Boeing's Crew Space Transportation CST-100 spacecraft which will be able to carry a crew of seven. [Credit: Boeing]

A mock-up of Boeing's Crew Space Transportation CST-100 spacecraft which will be able to carry a crew of seven. [Credit: Boeing]

Boeing and SpaceX have won the NASA contract as the first private companies to transport astronauts to the International Space Station.

The Commercial Crew program is aimed at ending the reliance on Russia to provide the transportation.

SpaceX's Dragon 2 craft. Dragon in 2012 became the first commercial spacecraft in history to deliver cargo to the International Space Station and safely return cargo to Earth [Credit: SpaceX]

SpaceX's Dragon 2 craft. Dragon in 2012 became the first commercial spacecraft in history to deliver cargo to the International Space Station and safely return cargo to Earth [Credit: SpaceX]

Boeing and SpaceX will receive a total of $6.8 billion to prepare for certification by 2017. That will include a crewed flight to the ISS. Each company will have to prove that their system is at least as safe as the old Space Shuttle program.

Based on each company's tender, Boeing will receive $4.2 billion and SpaceX $2.6 billion. 

The new vehicles will be Boeing's CST-100 and SpaceX's Dragon 2

The third contender, and the most radical design, Sierra Nevada Corporation's Dream Chaser craft was knocked out of the round.

The certification process will involve a flight with at least one NASA astronaut aboard to verify the fully integrated rocket and spacecraft system can launch, manoeuvre in orbit, and dock to the space station, as well as validate all its systems perform as expected.

Once each company passes NASA certification, they will conduct at least two, and as many as six, crewed missions to the space station. 

Are exoskeletons next season's must-have fashion accessory?

Harvard faculty member Conor Walsh and members of his team explain how the biologically inspired Soft Exosuit targets enhancing the mobility of healthy individuals and restoring the mobility of those with physical disabilities. [Credit: Harvard's Wyss Institute]. 

Exoskeletons may not yet offer the capabilities of Tony Stark's armoured flight suit of Iron Man fame, but a new wearable robotic suit being developed at Harvard's Wyss Institute is a potential game-changer.

Instead of the bulky, heavy metal versions that have been developed recently, researchers at Wyss turned to soft materials that work with the body's own movements and can be worn under clothing like a high tech, strength- and endurance-enhancing pair of long johns.

It could help people walk further, tire less easily, and carry heavy loads. The suit uses artificial muscles and tendons that work in parallel with a person's own muscles to give them a boost as they walk. The whole thing is powered by batteries and electric motors attached to a belt.

Wyss has just won support to the tune of nearly $3 million from the Defense Advanced Research Projects Agency (DARPA) to further develop the "Soft Exosuit".

The team also plans to work with clinical partners to develop a medical version of the suit that could help stroke victims walk again.

The Harvard Gazette explains.

The lightweight Soft Exosuit overcomes the drawbacks of traditional, heavier exoskeleton systems, such as power-hungry battery packs and rigid components that can interfere with natural joint movement. It is made of soft, functional textiles woven into a piece of smart clothing that is pulled on like a pair of pants, and is intended to be worn under a soldier’s regular gear. The suit mimics the action of leg muscles and tendons when a person walks, and provides small but carefully timed assistance at the leg joints without restricting the wearer’s movement...
In a current prototype, a series of webbing straps around the lower half of the body contain a low-power microprocessor and a network of supple strain sensors. These act as the “brain” and “nervous system” of the Soft Exosuit, respectively, continuously monitoring various data signals, including suit tension, wearer position (walking, running, crouched), and more.

Asian monsoon older than we thought – and it's going to get wetter

A study of the Asian monsoon 40 million years ago when carbon dioxide levels were four times today's suggests that wet seasons across the content are destined to get wetter. [Credit: iStock]

A study of the Asian monsoon 40 million years ago when carbon dioxide levels were four times today's suggests that wet seasons across the content are destined to get wetter. [Credit: iStock]

The Asian monsoon is much older than we thought, which means it was going strongly when carbon dioxide levels were nearly four times higher than now. That suggests the torrential rain dumped on the Asian continent in summer by the weather system is only going to increase.

Scientists had thought the the monsoon – the biggest weather system in the world – had begun 22-25 million years ago as a result of the uplift of the Tibetan Plateau and the Himalaya Mountains. The new study, though, has found the system already existed 40 million years ago. 

The research by Licht and his colleagues shows the earlier start of the monsoon occurred at a time when atmospheric CO2 was three to four times greater than it is now. The monsoon then weakened 34 million years ago when atmospheric CO2 then decreased by 50 percent and an ice age occurred.

Lead author Alexis Licht, now a research associate in the University of Arizona department of geosciences, said the study is the first to show the rise of the monsoon is as much a result of global climate as it is a result of topography.

The team's paper was published in Nature at the weekend.

Licht didn't set out to study the origin of the monsoon.

His research, when at the University of Poitiers, was focused on understanding the environments early primates inhabited. He chose a study site in Burma because the area was rich in fossils of some of the earliest ancestors of modern monkeys and apes.

To learn about the past environment, Licht analysed 40-million-year-old freshwater snail shells and teeth of mammals to see what types of oxygen they contained. The ratio of two different forms of oxygen, oxygen-18 and oxygen-16, shows whether the animal lived in a relatively wet climate or an arid one – a seasonal pattern very much like the current monsoon, with dry winters and very rainy summers.

"The early primates of Myanmar lived under intense seasonal stress – aridity and then monsoons," he said. "That was completely unexpected."

Licht will now go on to investigate how increases of atmospheric carbon dioxide affected the monsoon's behaviour 40 million years ago.

"The response of the monsoon ... could provide interesting analogs to the ongoing global warming," he said.

Scientists identify fracking gas-leak culprit

A 3D model of a natural gas rig shows how hydraulic fracturing works. The water pumped underground to break up shale is far below the water table. [Credit: iStock]

A 3D model of a natural gas rig shows how hydraulic fracturing works. The water pumped underground to break up shale is far below the water table. [Credit: iStock]

Faulty wells are the likely culprits for contamination of groundwater associated with hydraulic fracturing – better known as fracking – a study has found. But the problem may be fixable.

And the good news is that neither horizontal drilling nor hydraulic fracturing of shale deposits seems to have caused any of the natural gas contamination.

A team led by a researcher at Ohio State University, with researchers from Duke, Stanford, Dartmouth, and the University of Rochester, identified eight clusters of contaminated drinking-water wells in Pennsylvania and Texas.

Water pumped underground to break up shale during the fracking process is at a depth far below the water table. 

The long vertical pipes that carry the resulting gas upward are encircled in cement to keep the natural gas from leaking out along the well. 

The study suggests that natural gas that has leaked into aquifers is the result of failures in the cement used in the well.

"There is no question that in many instances elevated levels of natural gas are naturally occurring, but in a subset of cases, there is also clear evidence that there were human causes for the contamination," said Thomas Darrah, assistant professor of earth sciences at Ohio State. "However our data suggests that where contamination occurs, it was caused by poor casing and cementing in the wells," Darrah said.

The solution could be as simple as improved construction standards for cement well linings and casings at hydraulic fracturing sites.

The research was published this week in the Proceedings of the National Academy of Sciences.