CO2 levels mark 'new era' in the world's changing climate

Levels of CO2 in the atmosphere have surged past an important threshold and may not dip below it for "many generations".

The 400 parts per million benchmark was broken globally for the first time in recorded history in 2015.

But according to the World Meteorological Organisation (WMO), 2016 will likely be the first full year to exceed the mark.

The high levels can be partly attributed to a strong El Niño event.

Gas spike

While human emissions of CO2 remained fairly static between 2014 and 2015, the onset of a strong El Niño weather phenomenon caused a spike in levels of the gas in the atmosphere.

That's because the drought conditions in tropical regions produced by El Niño meant that vegetation was less able to absorb CO2. There were also extra emissions from fires, sparked by the drier conditions.

In its annual Greenhouse Gas Bulletin, the World Meteorological Organisation says the conditions helped push the growth in the levels of CO2 in the atmosphere above the average for the last ten years.

At the atmospheric monitoring station in Mauna Loa, Hawaii, levels of CO2 broke through 400 parts per million (ppm), meaning 400 molecules of CO2 for every one million molecules in the atmosphere.

The last time CO2 was regularly above 400ppm was three to five million years ago, say experts.

Prior to 1800 atmospheric levels were around 280ppm, according to the US National Oceanic And Atmospheric Administration (Noaa).

The WMO says that the rise through the 400ppm barrier has persisted and it's likely that 2016 will be the first full year when the measurements show CO2 above that benchmark, and "hence for many generations".

While the El Niño factor has now disappeared, the human impact on climate change has not, the WMO argues.

"The year 2015 ushered in a new era of optimism and climate action with the Paris climate change agreement," said WMO Secretary-General Petteri Taalas.

  http://ichef-1.bbci.co.uk/news/624/cpsprodpb/7D3D/production/_92016023_mlo_600.jpgThe air sampling station at Mauna Loa observatory in Hawaii which recorded CO2 levels going through 400ppm / NOAA

"But it will also make history as marking a new era of climate change reality with record high greenhouse gas concentrations."

The report also details the growth in other greenhouse gases, including methane and nitrous oxide.

In 2015, levels of methane were 2.5 times greater than in the pre-industrial era, while nitrous oxide was 1.2 times above the historic measure.

The study also points to the impact of these increased concentrations of warming gases on the world's climate.

Between 1990 and 2015 there was a 37% increase in radiative forcing or warming effect, caused by a build up of these substances, from industrial, agricultural and domestic activities.

While welcoming new initiatives like the global agreement to phase out HFC gases agreed recently in Rwanda, the WMO argues that nations must retain their focus on cutting CO2.

"Without tackling CO2 emissions, we cannot tackle climate change and keep temperature increases to below 2 degrees C above the pre-industrial era," said Petteri Taalas.

"It is therefore of the utmost importance that the Paris Agreement does indeed enter into force well ahead of schedule on 4 November and that we fast-track its implementation."

Around 200 nations who signed the Paris climate agreement will meet in Morocco in November to decide on the next steps forward.

Local fidelity key to ocean-wide recovery of humpback whales

Humpback whales can migrate thousands of miles to reach feeding grounds each year, but a new study concludes that their fidelity to certain local habitats -- as passed on through the generations -- and the protection of these habitats are key to understanding the ultimate recovery of this endangered species.

The study documents the local recruitment of whales in Glacier Bay and Icy Strait in Alaska over a 30-year period. The researchers found that contemporary whales that utilize these rich feeding grounds overwhelmingly are descendants of whales that previously used the area.

In other words, the population recovery of humpback whales in the region depends on cultural knowledge of migratory routes passed on from mothers to their calves; it is not a product of whales from outside the area suddenly "discovering" a rich feeding ground.

Results of the study are being published this week in the journal Endangered Species Research.

"Humpback whales are recovering from exploitation on an ocean-wide basis, but ultimately their individual success is on a much more local scale," said Scott Baker, associate director of the Marine Mammal Institute at Oregon State University and a co-author on the study.

"Humpback whales travel globally, but thrive locally."

The study compares records of individual whales returning to Glacier Bay. The first, referred to as the "founder's population," included whales documented by a local high school teacher, Charles Jurasz, beginning in the 1970s. Jurasz was one of the first researchers to realize that individual whales could be identified by photographs of natural markings -- a technique now widely used to study living whales.

Over the years, other researchers -- including the authors of this study -- continued to record the return of these whales by photo identification and they later collected small genetic samples to confirm the relatedness between individual whales.

Using a large database maintained by Glacier Bay National Park and the University of Alaska Southeast, the records of the founding population were then compared to records of the "contemporary population" returning to Glacier Bay, more than 30 years after Jurasz's initial studies. The results were striking.

Of the 25 "founding females" that were also sampled for genetic analysis, all but one was represented in the contemporary group -- either as still living, or by a direct descendant, or in many cases, both. Several of the founding females were even grandmothers of individuals in the contemporary population.

"We looked at three possibilities for population increase over a 33-year period including local recruitment from Glacier Bay/Icy Strait, recruitment from elsewhere in southeastern Alaska, and immigration from outside the region," said Sophie P. Pierszalowski, a master's student in OSU's Department of Fisheries and Wildlife and lead author on the study.

"It is clear that the contemporary generation of whales is based on local recruitment, highlighting the importance of protecting local habitat for recovering species, especially those with culturally inherited migratory destinations."

Humpback whales in the North Pacific were once estimated to number more than 15,000 individuals based on catch data before commercial whaling took a toll, reducing the population to less than a thousand by 1966. Humpback whales were first protected by the International Whaling Commission in 1965, then listed under the U.S. Endangered Species Act in 1973.

Since the protection, the oceanic population has increased to an estimated 21,000 individuals based on photo-identification studies and other evidence. The recovery has been slow, in part because humpback whales can live to be 70 years of age and their recovery is driven primarily by local fidelity and recruitment.

"Limiting vessel traffic in important habitats is one way to help protect humpback whales," Pierszalowski said, "along with maintaining legal distances by vessels, reducing the risk of entanglement with fishing gear, and maintaining stranding networks that have the capacity to quickly disentangle whales."

OSU's Marine Mammal Institute is based at the university's Hatfield Marine Science Center in Newport, Ore.

Limit to human life may be 115 (ish)

Human life spans may be limited to a maximum of about 115 years, claim US scientists.

Their conclusions, published in the journal Nature, were made by analysing decades of data on human longevity.

They said a rare few may live longer, but the odds were so poor you'd have to scour 10,000 planet Earths to find just one 125-year-old.

But while some scientists have praised the study, others have labelled it a dismal travesty.

Life expectancy has been increasing relentlessly since the nineteenth century - due to vaccines, safer childbirth and tackling killers like cancer and heart disease.

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But can that go on forever?

The team in New York analysed data from the Human Mortality Database and the deaths of super-centenarians (those over 110) in France, Japan, UK and US.

The data showed increases in life expectancy were slowing in centenarians and that the maximum age of death had plateaued for at least two decades.

Prof Jan Vijg, one of the researchers from the Albert Einstein College of Medicine, told the BBC News website: "In people over 105 we make very little progress, that tells you we are most likely approaching the limit to human life.

"For the first time in history we've been able to see this, it looks like the maximum life span - this ceiling, this barrier - is about 115.

"It's almost impossible you'll get beyond it, you need 10,000 world's like ours to end up with one individual in a given year who will live until 125 - so a very small chance."

The oldest person

 

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Jeanne Calment came close. The oldest ever person, whose age can be backed up by official documents, was 122 when she died in 1997.

The French icon of longevity was born before the Eiffel Tower was constructed and met the painter Vincent van Gogh.

Nobody has since got near her venerable age.

Prof Dame Linda Partridge, the director of the UCL Institute of Healthy Ageing, said a limit to lifespans "logically has to exist".

But she told the BBC: "Although this really interesting paper describes what is happening, it doesn't describe what will happen."

The crop of centenarians in the study were affected by malnutrition and infectious diseases in their childhood back in the late 19th Century. Remember smallpox was declared eradicated only in 1980.

"It was certainly very different to what the current birth cohort will go through, but it could yet be rather negative as a lot of children have grown up obese and that could bring lifespan down quite a lot," Prof Partridge added.

'Travesty'

The 115-year claim is too much for Prof James Vaupel, the director of the Max Planck Institute for Demographic Research.

He described the study as a dismal travesty and said scientists had in the past claimed the limit was 65, 85 and 105 only to be proven wrong over and over again.

He said: "In this sorry saga, those convinced that there are looming limits did not apply demography and statistics to test hypotheses about lifespan limits—instead they exploited rhetoric, deficient methods and pretty graphics to attempt to prove their gut feelings.

"[This study] adds nothing to scientific knowledge about how long we will live."

Experiments, which look after animals in ideal conditions, have suggested lifespans do have a limit.

Prof Jay Olshansky, from the University of Illinois, said mice tend to live for about 1,000 days, dogs for about 5,000 days and "humanity is approaching a natural limit to life".

Stopping ageing?

The challenge with tackling ageing is that we have not evolved to live to extreme old ages.

Millions of years of natural selection has honed us to survive, grow and reproduce in our youth.

What happens to our bodies half a century or more later - at ages we have never reached in our evolutionary history - are a side-effect of the instructions in our DNA that are important in youth.

So any attempt to really increase lifespan will need an approach that goes beyond treating diseases and tackles ageing inside every cell of the body.

Prof Jan Vijg added: "To get maximum life spans of 120, 125 or 130 maybe, we need to do something very fundamental here.

"We need to change the whole genetic make-up of the human species, you would have to develop thousands or tens of thousands of different drugs.

"The ageing process is so complicated that it will not be possible to substantially change this limit to human life."

Culex mosquitoes do not transmit zika virus, study finds

A Biosecurity Research Institute study has found important results in the fight against Zika virus: Culex mosquitoes do not appear to transmit Zika virus.

Researchers at Kansas State University's Biosecurity Research Institute studied Culex species mosquitoes from across the country, including Vero Beach in Florida, which is near Miami-Dade County where mosquitoes are spreading Zika virus.

The research, "Culex species mosquitoes and Zika virus," appears in the journal Vector-Borne and Zoonotic Diseases and involves researchers from Rutgers University, the University of Florida and the U.S. Department of Agriculture.

The findings are important for controlling Zika virus in Florida and preventing its spread to other parts of the country, said Dana Vanlandingham, lead author and assistant professor of virology in the College of Veterinary Medicine.

"It's very important to know that Culex mosquitoes are not able to transmit Zika," Vanlandingham said. "It enables people to target their control strategies so that they aren't wasting time and effort on a mosquito that isn't transmitting Zika virus."

It is the first Zika virus research publication from the Biosecurity Research Institute. Before this study, Culex mosquitoes' role in Zika virus was unclear. By studying Culex mosquitoes over a period of time, the researchers found that Zika virus did not multiply and instead disappeared in the species.

"This is great news," said Stephen Higgs, co-author and director of the Biosecurity Research Institute. "We can check this particular group of mosquitoes off the list here in the U.S. and focus efforts of control on the mosquitoes that we know can infect, like Aedes aegypti and Aedes albopictus."

The Centers for Disease Control and Prevention has identified Aedes aegypti, or yellow fever mosquito, and Aedes albopictus, or Asian tiger mosquito, as two species that transmit Zika virus. Both mosquitoes are widely distributed in the U.S. and are present in Kansas.

Culex mosquitoes are brown mosquitoes, while Aedes aegypti are black and Aedes albopictus are black and white. Culex mosquitoes transmit West Nile virus and Japanese encephalitis and live outside. Aedes aegypti and Aedes albopictus can live in and around houses in plant trays, spare containers or gutters.

"We need to know which mosquitoes to target and which mosquitoes not to target because mosquitoes live in different environments," said Vanlandingham, whose research focuses on zoonotic viruses -- such as Japanese encephalitis and chikungunya. "Some mosquitoes are found outside and some are more in people's homes. You need to know this in order to target your efforts."

Both Vanlandingham and Higgs emphasize the importance of personal responsibility in stopping the spread of Zika virus. Homeowners can get rid of small pools of water where mosquitoes breed and should use mosquito repellent as personal protection.

While a startup fund from the university's College of Veterinary Medicine provided funding for this Biosecurity Research Institute study, there is still a need for additional national funding to support research that stops Zika virus, said Higgs, who also has studied chikungunya, a mosquito-borne virus that has a similar transmission cycle to that of Zika virus.

"We thought that this research is so important with what is going on that we were able to use startup funding," Higgs said. "This research is basic research because we don't know some of the most fundamental information about mosquitoes. Applied research -- such as vaccines and diagnostics -- are obviously very important, but there is a need for funding basic research as well."

Iron nanoparticles make immune cells attack cancer

Iron nanoparticles can activate the immune system to attack cancer cells, according to a study led by researchers at the Stanford University School of Medicine.

The nanoparticles, which are commercially available as the injectable iron supplement ferumoxytol, are approved by the Food and Drug Administration to treat iron deficiency anemia.

The mouse study found that ferumoxytol prompts immune cells called tumor-associated macrophages to destroy cancer cells, suggesting that the nanoparticles could complement existing cancer treatments. The discovery, described in a paper published online Sept. 26 in Nature Nanotechnology, was made by accident while testing whether the nanoparticles could serve as Trojan horses by sneaking chemotherapy into tumors in mice.

"It was really surprising to us that the nanoparticles activated macrophages so that they started to attack cancer cells in mice," said Heike Daldrup-Link, MD, who is the study's senior author and an associate professor of radiology at the School of Medicine. "We think this concept should hold in human patients, too."

Daldrup-Link's team conducted an experiment that used three groups of mice: an experimental group that got nanoparticles loaded with chemo, a control group that got nanoparticles without chemo and a control group that got neither. The researchers made the unexpected observation that the growth of the tumors in control animals that got nanoparticles only was suppressed compared with the other controls.

Getting macrophages back on track

The researchers conducted a series of follow-up tests to characterize what was happening. Experimenting with cells in a dish, they showed that immune cells called tumor-associated macrophages were required for the nanoparticles' anti-cancer activity; in cell cultures without macrophages, the iron nanoparticles had no effect against cancer cells.

Before this study was done, it was already known that in healthy people, tumor-associated macrophages detect and eat individual tumor cells. However, large tumors can hijack the tumor-associated macrophages, causing them to stop attacking and instead begin secreting factors that promote the cancer's growth.

The study showed that the iron nanoparticles switch the macrophages back to their cancer-attacking state, as evidenced by tracking the products of the macrophages' metabolism and examining their patterns of gene expression.

Furthermore, in a mouse model of breast cancer, the researchers demonstrated that the ferumoxytol inhibited tumor growth when given in doses, adjusted for body weight, similar to those approved by the FDA for anemia treatment. Prior studies had shown that the nanoparticles are metabolized over a period of about six weeks, and the new study showed that the anti-cancer effect of a single dose of nanoparticles declined over about three weeks.

The scientists also tested whether the nanoparticles could stop cancer from spreading. In a mouse model of small-cell lung cancer, the nanoparticles reduced tumor formation in the liver, a common site of metastasis in both mice and humans. In a separate model of liver metastasis, pretreatment with nanoparticles before tumor cells were introduced greatly reduced the volume of liver tumors.

Potential clinical applications

The study's results suggest several possible applications to test in human trials, Daldrup-Link said. For instance, after surgery to remove a potentially metastatic tumor, patients often need chemotherapy but must wait until they recover from the operation to tolerate the severe side effects of conventional chemo. The iron nanoparticles lack the toxic side effects of chemotherapy, suggesting they might be given to patients during the surgical recovery period.

"We think this could bridge the time when the patient is quite sick after surgery, and help keep the cancer from spreading until they are able to receive chemotherapy," said Daldrup-Link.

The nanoparticles may also help cancer patients whose tumors can't be completely removed. "If there are some tumor cells left after surgery, the situation that cancer surgeons call positive margins, we think it might work to inject iron nanoparticles there, and the smaller tumor seeds could potentially be taken care of by our immune system," Daldrup-Link said.

The fact that the nanoparticles are already FDA-approved speeds the ability to test these applications in humans, she added.

The new findings will also help cancer researchers conduct more accurate evaluations of nanoparticle-drug combinations, Daldrup-Link said. "In many studies, researchers just consider nanoparticles as drug vehicles," she said. "But they may have hidden intrinsic effects that we won't appreciate unless we look at the nanoparticles themselves."

SpaceX 'Mars' rocket engine tested

Private firm SpaceX has carried out its first test of the Raptor rocket engine, designed to send humans to Mars.

SpaceX founder Elon Musk announced that the engine had been fired at the company's facility in McGregor, Texas.

If his vision is realised, it could power a super-heavy launch vehicle that would transport people to the Red Planet in coming decades.

But sending astronauts on round trips to our neighbour remains a formidable challenge.

Beyond the astronomical cost, there are the technical hurdles - currently unsolved - of protecting humans from the radiation levels they would be exposed to, once in deep space.

Mr Musk is set to outline his vision for a programme to colonise Mars at the International Astronautical Congress (IAC) in Guadalajara, Mexico, on Tuesday.

His announcement is being watched closely because SpaceX has already made several landmark achievements for a private space company, including successful upright landings of orbital rocket stages.

In an earlier series of tweets, Mr Musk pointed out the "Mach diamonds" in a picture of the engine test.

This is the name given to a type of wave pattern that appears in the supersonic exhaust plume of a rocket engine or jet engine.

When the Raptor was first announced in 2012, SpaceX said it would be several times more powerful than the Merlin 1 family of engines designed to power the company's Falcon launch vehicles.

And, unlike the Merlin engines, which use a combination of refined kerosene and liquid oxygen as fuel, the Raptor will be powered by liquid methane and liquid oxygen.

Raptor engines could eventually lift SpaceX's Mars Colonial Transport (MCT) towards the Red Planet.

For Mr Musk, Tuesday's speech should offer welcome respite from dealing with the fall-out of the company's launch pad explosion in September, which destroyed one of the company's Falcon 9 launchers and its payload - an Israeli-built communications satellite for Facebook.

Why don't antidepressants work in some patients?

Mouse study shows it may be down to your environment.

SSRI antidepressants (Selective Serotonin Reuptake Inhibitors, the best known being Prozactm) are amongst the most commonly taken medicines. However, there seems to be no way of knowing in advance whether or not SSRIs will work effectively. Now a group of European researchers has developed a new theory of SSRI action, and tested it in stressed mice. The results, which are presented at the ECNP conference in Vienna, show why the circumstances we find ourselves in may influence whether an antidepressant works or not.

According to researcher, Silvia Poggini (Istituto Superiore di Sanità, Rome), "There is no doubt that antidepressants work for many people, but for between 30 and 50% of depressed people, antidepressants don't work. No-one knows why. This work may explain part of the reason."

The researchers have proposed that simply increasing the levels of serotonin, by taking an SSRI, does not cause a recovery from depression, but puts the brain into a condition where change can take place -- it increases the plasticity of the brain, making it more open to being changed. "In a certain way it seems that the SSRIs open the brain to being moved from a fixed state of unhappiness, to a condition where other circumstances can determine whether or not you recover" said Ms Poggini. According to the researchers, it is the environmental conditions you find yourselves in at the time of the treatment which determines whether you are likely to get better or worse.

To test this, they took a sample of mice which they subjected to stress for two weeks. They started treating the mice with the SSRI fluoxetine, and split the group. They continued to stress half (n=12) of the group of mice but the other half of the mice were subjected to a more comfortable environment. They then tested all the mice to measure the levels of the stress-related cytokines in the brain. Cytokines are protein-related molecules which aid cell to cell communication in the immune system.

They found that mice kept in a more comfortable environment showed an increase in the expression of pro-inflammatory cytokines and decreased anti-inflammatory-related genes, as well as showing fewer signs of depression, whereas those under continuous stress showed the opposite effect (i.e. a decrease in pro-inflammatory cytokines, and an increase in anti-inflammatory gene expression, with more signs of depression). The fluoxetine-treated mice exposed to the comfortable environment showed a 98% increase in the pro-inflammatory cytokines IL-1β while mice kept in a stressed environment and treated with fluoxetine showed a 30% decrease in the pro-inflammatory cytokines TNF-α.

This indicates that the environment determines the response to antidepressants. According to Silvia Poggini, "This work indicates that simply taking an SSRI is probably not enough. To use an analogy, the SSRIs put you in the boat, but a rough sea can determine whether you will enjoy the trip. For an SSRI to work well, you may need to be in a favourable environment. This may mean that we have to consider how we can adapt our circumstances, and that antidepressant treatment would only be one tool to use against depression."

She cautioned "Our studies have a number of limitations. First of all, we are not explaining the complete range of actions of SSRIs. It's also an animal model, so clinical and epidemiological studies are needed to further test the validity of the hypothesis. Our results are preliminary and we strongly recommend that patients stick to the treatment prescribed by their doctors."

Commenting, Dr Laurence Lanfumey (Centre de Psychiatrie et Neuroscience Inserm, Paris), Member of the ECNP Executive Committee, said, "This original study is a nice model for combined behavioral and pharmacological treatments in depression- like disorders. The idea that environment could impact the output of a pharmacological treatment has been suggested for years, but this work brings direct biological evidences of such an interaction. Although the present work also raised several questions, this kind of experiment is important to do to bridge the gap between behavior and SSRIs efficacy."

Modern environment blamed for 40% rise in children’s cancer cases

The number of cancer cases in children has leapt by 40 per cent in less than two decades because of pollution, pesticides and gadgets, new analysis has shown.

There are 1,300 more diagnoses of the disease a year in people under the age of 25 compared to 1998 – costing the NHS £130 million extra a year.

Cases of colon cancer in children are up 200 per cent, while thyroid cancer cases have more than doubled.

Ovarian and cervical cancer cases have also seen stark rises – up by 70 per cent and 50 per cent respectively, analysis of ONS data by the charity Children with Cancer UK found.

Around 4,000 children and young people develop cancer each year and it is the leading cause of death in children aged one to 14 in the UK.

The 40 per cent jump in cases over 16 years is partially attributed to population growth, as the incidence rate per 100,000 people has risen by 30 per cent.

However, Professor Denis Henshaw, scientific director at Children with Cancer UK, said that lifestyle and environmental factors could play a part in the rise.

“These significant rises in cancer cases cannot be explained by improvements in cancer diagnosis or registration alone – lifestyle and environmental causal factors must be considered.”

He said that burnt barbecues, the electric fields of power lines, and hairdriers were contributors to the rise, as well as a pregnant women’s diet and working shifts.

“We were shocked to see the figures, and it’s the modern lifestyle I’m afraid. Many items on the list of environmental causes are now known to be carcinogenic, such as air pollution and pesticides and solvents.”

He added: “What’s worrying is it is very hard to avoid a lot of these things. How can you avoid air pollution? It sometimes feels like we are fighting a losing battle.”

Children with Cancer UK are calling on the Government and medical and science community to ensure children with cancer have access to precision medicine by 2020.

The charity is hosting a three-day international conference on childhood cancer which begins today. It will look at precision medicine, immunotherapy and influenceable causes of childhood cancer.

Precision medicine – which considers an individual’s genes, environment and lifestyle to provide more targeted treatment – needs to be offered to all young people within the framework of clinical trials by 2020, the charity’s medical director has claimed.

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