Features

SAN FRANCISCO — Microsoft’s HoloLens goggles have hit a sweet spot between Google Glass and virtual reality headgear, immersing users in a mesmerising world of augmented reality holograms.

The glasses, which the US technology titan sprang on an unsuspecting press recently, elicited descriptions such as “magical” and “unbelievable”, the first time in a while such praise was heaped on a Microsoft creation.

The augmented reality goggles are a step in a different direction from virtual reality headgear such as Oculus Rift and Sony’s Project Morpheus system, as well as Google Glass.

At private demos of HoloLens in a carefully guarded lower level of Microsoft’s campus in Redmond, Washington, cameras, recording devices and even smartphones were not permitted.

Microsoft executives said the holographic capabilities built into Windows 10 operating software — to be released late this year — would open doors for developers to augment tasks from complex surgery to motorcycle design.

In a captivating demonstration, a prototype HoloLens turned a room into the surface of Mars.

HoloLens wearers found themselves standing near a 3D representation of the Rover, free to roam Mars, at times accompanied by a NASA scientist projected into the scene and communicating through Skype.

“This is the future of space exploration,” said the scientist, represented by a glowing golden spacesuit reminiscent of vintage science fiction films.

NASA team members can use HoloLens to move about as if they are on Mars and figure out where they want the Rover to go and what they want it to do.

Work and play

Through a series of scenarios, HoloLens overlaid virtual scenes on real space, allowing wearers to safely and efficiently navigate rooms while engaging with 3D imagery using voice, gaze or gesture.

The head piece tracks eye movements, then lets wearers use a simple finger flick to interact with whatever they focus on.

Replacing a light switch became a collaborative effort, as one individual with a tablet computer guided the job, overlaying arrows or notes that floated in the air.

The room was then converted into an extension of the building block themed game Minecraft, with castles on floors and table tops. With voice commands and taps of the finger, a wearer built or destroyed, and sometimes vanquished zombies.

The Microsoft headgear even became a tool for designing virtual toys then made real using a 3D printer.

HoloLens also promises scintillating integration with video games, and Microsoft has a broad and devoted fan base for Xbox consoles.

The future of computing

“HoloLens offers a new platform and experience for computing on the scale of the original PC and the launch of Apple iPhone,” Forrester analyst Frank Gillett said in a blog post.

And Facebook co-founder Mark Zuckerberg has depicted virtual reality as a computing platform poised to succeed the mobile Internet era centred on smartphones and tablets.

He backed his belief by buying Oculus VR last year in a $2 billion deal.

Because virtual reality headgear disconnects users from their immediate surroundings, some people worry about what is happening in reality or what they might bump into.

“Virtual reality makes sense for gamers pretty much immediately,” said Endpoint Technologies analyst Roger Kay.

“I think augmented reality is actually how this type of technology is going to hit in to the general population.”

By contrast, Google Glass essentially displays a miniature version of a smartphone screen in an upper corner of one lens.

People can glance to see text messages, video or other scenes in small displays, and also take pictures or video, controlling the eyewear with voice commands or taps on frames.

Google recently ended sales of Glass through an Explorer programme, but a lower cost and more fashionable version is expected to make it to market.

“I have to say Microsoft has truly delivered a mixed reality experience that will delight,” Forrester analyst James McQuivey said in a blog post.

“It’s on everybody else — from Apple to Samsung, Oculus VR to Magic Leap — to match Microsoft’s opening bid.”

“Leave it till tomorrow to unpack my case, honey disconnect the phone,” sang Beatle Paul McCartney in 1968 in “Back in the USSR”, the opening song of the now legendary White Album. To have peace of mind for a short while all that they needed to disconnect back then was to pull out the cable of a simple analogue phone. How many devices and systems to disconnect today for peace of mind? Not to mention that actual disconnection (from the web) consists of more than a simple wire to unplug.

Comes a time when too much is too much. We may not be there yet but we’re surely approaching a situation where excessive web connection to IT networks is going to backfire.

The industry, understandably, wants you to connect every single object you own and use. It’s a vicious circle of the worst kind. By buying more connected devices we serve, willingly or unwillingly, as guinea pigs, as the perfect testing ground and lab for the industry that, therefore, can use our feedback and experience to improve the devices, only to inject more of them in the market. And all over again.

It makes sense to have a computer of a smartphone connected, but why should a spoon (yes a spoon…) be connected? It’s been almost two years since Hapilabs introduced the Hapispoon that can warn you if you eat too fast or too much and that can keep a record of your good or bad eating habits by sending the report over the web. “Another tool in a utensil drawer that won’t be used,” was one of the comments found on the web about the Hapispoon.

Many of the famous Japanese makers of wristwatches, with Seiko and Citizen in the lead, are now offering models that are connected to the Internet. These are not digital smartwatches that talk to your smartphone via Bluetooth but regular, often fancy and expensive wristwatches that rely on the connection to keep perfect time and date depending on where you live, where you are travelling, as well as your location’s daylight saving time. Not forgetting their ability at reading your GPS position.

It takes a little time to say whether a connected object is useful or ridiculous. Without enough time one does not have enough perspective to tell. Some cases, like the Hapispoon, however are obvious!

A web connected collar to locate your pet or a tiny device to locate your luggage in an airport can prove handy, but where do you set a limit?

Canadian innovator Hexoskin last year suggested a connected shirt that monitors your body and sends alerts about your health in specific cases. Readiymate goes further. The company proposes DIY kits that let you turn some objects into web connected ones, admitting they become merely toys — albeit connected ones.

At the 2015 edition of Los Angeles celebrated CES technology show, wearable web connected objects attracted huge audience.

“At the end of the day, what we’re creating is information,” says Ric Asselstine, CEO of Terepac Corp., a maker of microelectronics that are integrated into objects so as to make them smart. It may true but excessive amount of information precisely is the core issue today. The more information is generated and the higher the risk of hacking, of identity theft, and of plain theft of property and wealth. Not to mention that most of the time it is all but raw information, not having undergone any meaningful or useful analysis.

The sky is the limit goes the saying. When it comes to high-tech and web connectivity it is more outer space than just the sky. Soon we will want to scream “enough” and disconnect.

LONDON — Video-based therapy for families with babies at risk of autism improves infants’ engagement, attention and social behaviour, and might reduce their risk chances of developing the condition, the findings of a small scientific study show.

Researchers publishing the findings in The Lancet Psychiatry journal said they showed that using video feedback-based therapy to help parents understand and respond to their baby’s early communication style might help modify emerging autism symptoms.

“Targeting the earliest risk markers of autism, such as lack of attention or reduced social interest or engagement, during the first year of life may lessen the development of these symptoms later,” said Jonathan Green, a Manchester University professor of child and adolescent psychiatry, who led the study.

People with autism have varying levels of impairment across three areas: social interaction and understanding, repetitive behaviour and interests, and language and communication.

The exact causes of the neurodevelopmental disorder are not known, but evidence shows they are likely to include a range of genetic and environmental factors.

As many as one in 50 school-age children in the United States are diagnosed with autism, although some of these will be milder cases. In Europe, the rate is around one in 100 children.

“It will be important to document whether any such changes observed in the children’s behaviour persist in the absence of continued intervention,” said Melissa Allen, an autism specialist at the University of Lancaster.

SYDNEY — Australia faces a rise in temperature of potentially more than 5^oC by the end of the century, outpacing global warming worldwide, the country’s national science agency said on Tuesday.

In its most comprehensive analysis yet of the impacts of climate change, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) painted a worst-case scenario of a rise of up to 5.1^oC by 2090 if there are no actions taken to cut greenhouse emissions.

“There is a very high confidence that hot days will become more frequent and hotter,” CSIRO principal research scientist Kevin Hennessy said. “We also have very high confidence that sea levels will rise, oceans will become more acidic, and snow depths will decline.”

The dire warning from the government-funded agency is at odds with the official line from Australian Prime Minister Tony Abbott, who in 2009 declared the science of climate change was “crap”.

Abbott last year scrapped a tax on carbon pricing and abolished the independent Climate Commission, saying recent severe droughts that have crippled cattle farmers were “not a new thing in Australia.”

As the host of the Group of 20 last year, he attempted to keep climate change off the agenda, resulting in an embarrassing backdown at the Leaders Summit in Brisbane after US President Barack Obama used a high-profile speech to warn Australia that its own Great Barrier Reef was in danger.

One of the world’s biggest carbon emitters per capita, Australia initially declined to join the United States, Japan, France and others in contributing to the United Nations’ Green Climate Fund.

At the Lima climate change conference in December, Australia announced it would provide A$200 million from its existing aid budget — a method of contributing that went against agreements when the fund was set up at the Copenhagen conference in 2009.

Abbott has committed A$2.55 billion ($2.21 billion) to a domestic initiative to reduce Australian’s emissions by 5 per cent below 2000 levels by 2020.

The new research by CSIRO and the Bureau of Meteorology, using some 40 global climate models, has Australia warming at a greater rate than the rest of the world.

The 5.1^oC projection for 2090 is at the top end of a range starting at 2.8 ^oC and is dependent on how deeply, if at all, greenhouse gas emissions are cut. The world average is for an increase of between 2.6^oC and 4.8^oC.

The report said the annual average temperature in Australia would likely be up to 1.3^oC warmer in 2030 than the average experienced between 1986 and 2005.

To compound our misery, my favourite supermarket right across the road from our house, has been bought over and the new owners have hiked up the prices of everything and anything in their store. 

Which is fine, I mean, how can I argue with their personal business decision? But what gets me mad, and continues to give me a steady rise in blood pressure is their manner of doing so. 

The consistent theme in this brand-new store is the total lack of customer care; the concept is not understood somehow. All their salespeople have the same mindset, and it is as if they are obliging us by providing the goods. The fact that we pay exorbitant amounts of money to procure them simply escapes their notice.

Where “consumer is always right” philosophy is not assured what can one expect but continual bad service? I will recount one incident for you, dear readers, and you can judge for yourself. 

A week ago I went there to buy some groceries and picked up a packet of lentils. The price tag read one figure but when I went to pay for it at the cash till, the machine announced four times the amount! For that one item! 

We could not believe our eyes, the lady cashier as well as me. She swiped the packet again, and the result was also the same: JD2 on the packet and JD8 on the tiny computer screen. 

After complaining to the storeowner, an irritable man on a wheelchair, he proceeded to explain the error. Apparently, the price of the commodity had been raised and recorded on the computer software but had simultaneously not been increased on the labels of the products. 

Now, whose fault was that? Why should the buyer be made to pay for this oversight on the part of the mismanaged shop? I lost my temper and got into a heated argument. After much quarrelling, my overcharged money was returned to me, so I went back somewhat placated. 

If it were any other country my entire shopping would have been compensated. Client wooing strategies were different there. But in this shop such pampering of the consumer was unheard of. If anything, they were ready to chase me off their grounds. 

By now, a seed of doubt had settled in my head, and I simply could not shake it off. Supposing I had not noticed this swindling and deception on my own, would I have been cheated time and again? Perhaps yes, but did the management care? I don’t think so. 

Yesterday, I went back again, to pick up a shampoo. The manager they had recently hired was rude, obnoxiously so. What was the problem, said the voice in my head? Why was he so disinclined towards being pleasant?

The purchase I made was once more wrongly marked. Actually, it was not even marked but was placed on a shelf where it was not supposed to be. And the rack where it belonged had other, latest versions of the brand, which were at a higher price. 

I figured that out, but since there was no price-sticker on it, I was made to wait while they went and manufactured a new one. The person-in-charge did not have an apology to offer. He just snatched the JD10 note from my hand. And then thrust the pack at me.

I just wish I had pushed the shopping trolley over his right foot. 

NEW YORK — A new wave of experimental cancer drugs that directly recruit the immune system’s powerful T cells are proving to be immensely effective weapons against tumours, potentially transforming the $100 billion global market for drugs that fight the disease.

But top oncology researchers are concerned about the two emerging technologies, citing dangers seen repeatedly in clinical trials including the potentially fatal buildup of toxic debris from killed tumour cells and damage to healthy tissue. Such side effects could block regulatory approval if they aren’t controlled, researchers and drug company executives said in interviews with Reuters.

In some trials, the two new approaches, known as CAR T cells and bispecific antibodies, have eliminated all traces of blood cancers in 40 to 90 per cent of patients who had no remaining options. The drugs could reap annual sales in the tens of billions of dollars for their manufacturers, especially if they can also eliminate solid tumours in such terminally ill patients.

CAR T cells, or chimeric antigen receptor T cells, are T cells that have been removed from the body and attached through genetic engineering to an antibody fragment that recognises a specific tumour protein. T cells are an especially powerful disease fighting kind of white blood cell. The result is a drug with the killing power of a greatly enhanced T cell, combined with the spotting-spotting ability of an antibody.

Bispecific antibodies are a twist on conventional antibodies, Y-shaped proteins whose two arms grasp for the same protein target found on cancer cells.

With bispecifics, one arm of the antibody typically grasps a cancer cell while the other arm takes hold of T cells, bringing the mortal enemies into contact. The T cell punches holes into the adjacent tumour cell and injects deadly enzymes. Conventional antibodies, by contrast, don’t directly recruit T cells.

“Unleashing the killing power of the T cell directly on the tumour cells allows a large increase in potency of these antibodies,” said Dr David Scheinberg, chairman of molecular pharmacology at Memorial Sloan Kettering Cancer Centre.

Investor excitement over these therapies have helped boost interest from companies including Amgen Inc. and Roche and have fuelled a jump in share prices of smaller firms such as Kite Pharma Inc., Juno Therapeutics and Bluebird Bio.

“We take patients that have failed every treatment, every chemo combination, that have just two to six months to live. You give them a CAR, and within three to four weeks you can see massive tumours melting away,” said Arie Belldegrun, chief executive officer of Kite. The company went public in June and announced a partnership with Amgen earlier this month.

CAR T cells could cost $300,000 to $500,000 per patient, if approved, making them among the world’s most expensive drugs and testing the ability of insurers to pay for them, said Les Funtleyder of E Squared Asset Management. The hedge fund owns shares of Kite Pharma. Bispecific antibodies could command prices of $200,000 or higher, he said.

The potency of the experimental drugs comes with some dangerous potential side effects. In the killing process, inflammatory chemicals from the medicines and the tumour cells, called cytokines, are released into the bloodstream and can cause fever, low blood pressure and rapid heartbeat that can be life threatening.

The drugs, because of their unique structure and how they work, make it harder to predict whether they will go astray, said Dr Bindu George, team leader of the US Food and Drug Administration’s Office of Cellular, Tissue and Gene Therapies, who called CAR T drugs perhaps the most interesting new technology.

Most CAR T cells and bispecific antibodies in development identify blood cancer cells by a specific protein, CD19, found on the surfaces of lymphomas and leukaemias. Because the same protein can also be found on non-cancerous cells, the drugs can go off track and attack healthy tissues.

“Our biggest concern would be an off-target toxicity that wasn’t expected and we didn’t know the cause of it,” George said. In that case, “we might have to ask [the drugmaker] for additional information, how the toxicity happened, what organ it was, and literally go back to the drawing board.”

Taming a powerful drug

Researchers have used anti-inflammation medications to tame some of the adverse reactions, not always successfully. A study of CAR T cell treatment sponsored by Juno for patients with aggressive non-Hodgkin’s lymphoma was briefly put on hold after two people died.

Unlike antibodies, which are excreted from the body within days or weeks, engineered CAR T cells are expected to circulate for years or even a lifetime in the bloodstream, potentially providing lasting benefits, but also risks.

“You can start to reject normal tissues; it can kill organs or cause autoimmune disease, and you don’t want that,” said Zelig Eshhar, a professor emeritus of the Weizmann Institute in Israel who pioneered the CAR approach.

To reduce that danger, researchers are attempting to build “suicide switches” into CAR T cells to turn them off after they have wiped out all signs of cancer.

At least 30 bispecific antibodies are believed to be in development, including ones from Roche, Johnson & Johnson, AbbVie and Eli Lilly.

A growing number of drugmakers are also racing to develop the first CAR T therapies, including Kite, Novartis, Juno, Cellectis and its partner Pfizer Inc., and Bluebird, in partnership with Celgene Corp.

Expensive option

The FDA in December approved the first bispecific, Amgen’s $178,000 Blincyto for acute lymphoblastic leukaemia (ALL) that did not respond to previous treatment. The cancer, prevalent in children, is diagnosed each year in an estimated 6,020 Americans, killing about a fourth of them.

One-third of patients in the Amgen study had no detectable cancer for nearly seven months after receiving the drug through a month-long infusion.

A main hope for Blincyto is that it will keep patients alive until they can receive stem cell transplants, their best chance of a possible cure.

CAR technology may also come to the rescue where few options remain.

“If doctors and specialists learn how to control this very powerful gun, CAR T cells could save hundreds of thousands of people in the United States,” said Ori Hershkowitz, a Tel Aviv-based fund manager with Sphera Funds, which owns shares of Kite and rival CARs developer Novartis.

A Novartis trial showed 27 of 30 children and adults with ALL had no signs of the disease after being treated with its CAR T drug. Some 78 per cent of patients were still alive six months after treatment, while some sustained remission for up to two years.

But everyone in the study developed cytokine release syndrome, including a severe form of it in 27 per cent of patients.

“It certainly needs to be watched and evaluated,” said Usman Azam, global head of cell therapies for Novartis. He still believes the drug’s benefits provide “compelling hope that you can potentially cure patients”.

Roche’s Genentech unit is conducting a mid-stage trial of a bispecific antibody to treat head and neck cancer and colorectal cancer. It is studying a dozen others in preclinical trials against cancer, Alzheimer’s disease and inflammatory diseases.

Paul Carter, a Genentech executive, was cautious about the prospects.

“It’s too early to say whether this will be a home run, although there’s optimism it will be at least a base hit that will help us figure out how to go further.”

SAN FRANCISCO — Apple CEO Tim Cook says consumer demand for new iPhones has been "staggering" and "hard to comprehend”. That helped the company report record-smashing earnings for its latest quarter and primed its stock for a rally Wednesday.

But after selling a record 74.5 million iPhones in three months that ended in December, what can Apple do next?

Some analysts worry that Apple depends too much on the iPhone, which contributes two-thirds of its sizeable revenue — leaving the company vulnerable if some other gadget comes along to replace the iPhone in popularity. Cook and Chief Financial Officer Luca Maestri, however, say they're optimistic about other products in Apple's portfolio. Here's some of what they talked about on Tuesday.

Apple Watch

Apple plans to start selling its highly anticipated smartwatch in April, Cook told analysts on a conference call after the company's earnings report Tuesday. He added that developers are working on new apps called "Glances" — apparently in reference to the way people will view those apps on their wrists.

Cook boasted he's already wearing and enjoying an early model. "I'm using it every day and love it and can't live without it," he said.

Still, some analysts say it's difficult to predict demand for the Apple Watch. "We continue to believe interest from consumers is tepid," said Piper Jaffray's Gene Munster in a recent note to investors.

Apple Pay

Apple introduced its digital payments service last fall, but Cook vowed Tuesday that "2015 will be the year of Apple Pay”. He said 750 banks have signed up for the programme, which now accounts for two out of every three dollars spent through so-called "contactless" payment systems, as opposed to credit cards that are swiped at the point of sale.

While Apple is believed to collect fees from banks when shoppers use Apple Pay, it doesn't specifically disclose revenue from the service. BGC Partners analyst Colin Gillis says he doesn't expect the programme will make a "material" contribution to Apple's revenue in the near future.

Other devices

Apple said sales of Macintosh computers were up 9 per cent in the last quarter. The company increased its share of the personal computer market at a time when overall PC sales were declining. Apple no longer reports separate numbers for its iPod music players.

But iPad sales fell 22 per cent. Even so, Maestri said surveys show consumers love iPads for web-browsing and shopping, and he said new apps produced in partnership with IBM will increase business uses for the devices. The iPad has "a very bright future”, Cook added, although he cautioned he doesn't expect sales trends to change in the next couple of quarters.

New markets

Apple says iPhone sales doubled in China, Brazil and Singapore in the last quarter, despite aggressive competition from South Korea's Samsung and the Chinese companies Huawei and Xiaomi. Cook also boasted the company saw record rates of first-time iPhone buyers and former owners of Android phones who are switching to Apple devices, although he didn't provide specifics.

Overall, Apple reported $74.6 billion in sales and $18 billion in profit for the December quarter, which represents a year-over-year increase of 30 per cent and 38 per cent respectively. Based on those numbers, analyst Bill Kreher of the Edward Jones investment firm said he'll be raising his forecasts for the company's performance this year.

Even so, he added, as Apple keeps setting records, "it's certainly going to be more difficult for them to continue to beat expectations”.

Signalling a rally Wednesday, Apple's stock rose almost 6 per cent in after-market trading following the earnings report late Tuesday.

WASHINGTON — Facebook, the world's most popular social network, and its Instagram photo site were interrupted temporarily Tuesday, provoking panic, rumours of a hack, and jokes of how more than one billion users were struggling to cope.

"This was not the result of a third party attack," Facebook said in a statement after its services were restored.

The outage "occurred after we introduced a change that affected our configuration systems”, it added.

The breakdown, at around 0615 GMT, reportedly lasted an hour and hit users in the United States, Europe and Asia, with both sites showing error messages.

With users disabled from posting selfies or the latest details of their personal lives, many rushed to Twitter to complain and joke, with "#facebookdown" and "#SocialMeltdown2015" rapidly trending.

Some joked about how they had been able to read real books during the enforced social media pause.

"Status Update: Facebook is Down!!!" Twitter user @kingpodge posted, in a photographed handwritten note.

"It's, like, really snowing in New York and now Facebook and Instagram are down. The hipster apocalypse has begun," tweeted another user, @jessbrammar, as a snowstorm swept across the east coast of the United States.

"Things to do during #SocialMeldown2015 1. Take a selfie 2. Melt down further because we can't instagram it," posted @YashiDP.

"#facebookdown and I hope it never gets up again! Imagine the lives that would be saved!" tweeted @nikonical.

Some suggested that hacking group Lizard Squad had been responsible for the outage, after a tweet on the group's Twitter account read: "Facebook, Instagram, Tinder, AIM, Hipchat #offline #LizardSquad."

Reports said that Tinder, AIM, Hipchat and My Space had also been affected.

Lizard Squad has claimed to be behind a series hacks of Microsoft and Sony gaming networks over Christmas.

The group also claimed an attack on the website of Malaysia Airlines on Monday, referencing the Islamic State jihadists and threatening to expose data taken from the carrier's servers.

Facebook, which is headquartered in California, has more than 1.35 billion active users each month.

The last time Facebook was down was last September.

LONDON/DAKAR — A recent sharp drop in new Ebola infections in West Africa is prompting scientists to wonder whether the virus may be silently immunising some people at the same time as brutally killing their neighbours.

So-called “asymptomatic” Ebola cases — in which someone is exposed to the virus, develops antibodies, but doesn’t get sick or suffer symptoms — are hotly disputed among scientists, with some saying their existence is little more than a pipe dream.

Yet if, as some studies suggest, such cases do occur in epidemics of the deadly disease, they may be a key factor in ending outbreaks more swiftly by giving secret protection to those lucky enough to be able to bat the infection away.

“We wonder whether ‘herd immunity’ is secretly coming up — when you get a critical mass of people who are protected, because if they are asymptomatic they are then immune,” Philippe Maughan, senior operations administrator for the humanitarian branch of the European Commission, told Reuters. “The virus may be bumping into people it can’t infect any more.”

Latest World Health Organisation data show new cases of infection in West Africa’s unprecedented Ebola epidemic dropping dramatically in Guinea, Sierra Leone and particularly in Liberia.

Most experts are sure the main driver is better control measures reducing direct contact with contagious patients and corpses, but there may also be other factors at work.

So-called herd immunity is a feature of many infectious diseases and can, in some cases, dampen an outbreak if enough people get asymptomatic, or “sub-clinical” cases and acquire protective antibodies. After a while, the virus — be it flu, measles, polio — can’t find non-immune people to be its hosts.

But some specialists with wide experience of disease outbreaks are highly sceptical about whether this phenomenon happens in Ebola, or whether it could affect an epidemic.

“There is some suggestion there may be cases that are less severe... and there may even be some that are asymptomatic,” said David Heymann, an infectious disease expert and head of global health security at Chatham House.

“But herd immunity is just the wrong term. There could be household immunity developing, but even that is only hypothesis.”

Others are more hopeful and are urging researchers in West Africa to seek out and test possible asymptomatic cases with a view to using the secrets of their silent immunity.

Steve Bellan of the University of Texas in the United States argues that if scientists can reliably identify asymptomatic people, they could help with disease-control tasks like caring for patients and conducting burials, reducing the number of non-immune people exposed in these risky jobs.

Bellan points to two studies in particular. One, conducted after an Ebola outbreak in Gabon in 1997, found that 71 per cent of “seropositive” people — those with traces of the Ebola virus in their blood — did not have the disease. The other, published in April 2002, found 46 per cent of asymptomatic close contacts of patients with Ebola were seropositive.

With the largest Ebola epidemic on record raging through three of Africa’s most under-resourced countries, scientists and medics have, understandably, focussed all efforts on the sick and dying and not on testing people with no symptoms.

If they do, however, and if they were to find what Bellan and some others suspect, it could prompt a reappraisal of what jolted a relatively sudden downturn in new cases.

Some researchers say they have identified a few cases in the current outbreak with mild symptoms and low concentrations of Ebola virus in the blood. One was a Guinean student who travelled to Senegal and is not known to have infected anyone else, despite having contact with dozens of people.

Ian MacKay, a virologist at Australia’s University of Queensland, agrees that possible sub-clinically-acquired immunity is one of many unexplored mysteries of the Ebola virus.

“One thing that this particular outbreak shows is that we really don’t know an awful lot about these kinds of infectious diseases,” he said. “We tend to think we can answer all the questions, but this is one of those things we may end up being taught by the virus itself.”

PARIS — Suspicions that shooting stars come from comet dust, transformed into fiery streaks as they hit Earth’s atmosphere, have been bolstered by Europe’s Rosetta space mission, scientists reported Monday.

Comets and asteroids have both been eyed as possible progenitors of meteors, also known as shooting or falling stars — and now particles spewed from comet 67P/Churyumov-Gerasimenko have provided proof of paternity.

“This paper shows for the first time that the fluffy, dry dust particles of a comet are [the] parents” of interplanetary dust particles [IDPs] which give us shooting stars, Rita Schulz of the European Space Agency (ESA) told AFP.

Published in the journal Nature, the study saw ESA’s probe Rosetta snare and analyse dust ejected from 67P as the comet raced towards the sun, hundreds of millions of kilometres from Earth.

Comets are clusters of primordial dust and ice that orbit our star in elliptical circuits. 

As they near the sun, melted dust and ice is deposited in their wake as a visible “tail” that disappears from view as they head back into the solar system — a cycle that continues until the celestial wanderers finally disintegrates.

Comet 67P has an orbit of about six-and-a-half years — about four years of each cycle are spent in the cold outer reaches of space far from the sun.

‘Fluffy and porous’

During this time, the gassy outflow too feeble to lift grains from its surface, the comet builds up an outer dust mantle. But as the comet draws closer to the sun again, and is reactivated by its heat, the mantle starts to disintegrate and dust particles are shed.

The comet’s most recent switch into active mode was observed from up close by Rosetta since its arrival in August last year to October — orbiting 67P at a distance of 30km or less.

Particles collected by Rosetta’s COSIMA instrument during this period, when the comet moved from a distance of 535 million kilometres to 450 million kilometres from the sun, shattered on contact, said Schultz. 

The particles were about 50 micrometres (0.05 millimetres) in size before breaking.

“They are fluffy and porous and rich in Na. [sodium],” said Schulz — characteristics that led the team to conclude that “these particles likely represent the parents of interplanetary dust particles.”

IDPs, in turn, are what we see as shooting stars if they enter Earth’s atmosphere.

The study gives important backing for mathematical models of the source of shooting stars. For example, the Leonids, a meteor shower that occurs every November, have been associated with a comet called 55P/Tempel-Tuttle.

“There has been a long-standing dispute of whether the source of IDPs are solely comets or also asteroids,” said Schultz. “Our results imply that they have cometary origin. Another source would not be required.”

Asteroids are considered to be far more numerous than comets, but their composition is different. They are rocks, much smaller than planets, which circle the sun, mainly in a belt between Mars and Jupiter. 

Comet 67P’s outer dust mantle should be entire shed soon, if it has not happened already, said the study authors. 

As a result, the particles that will be collected for the remainder of Rosetta’s mission will have very different properties as the ones used in the study.

Rosetta’s journey to 67P took more than a decade from 2004 and 6.5 billion kilometres.

Last November, the craft placed a washing machine-sized robot lab, Philae, on the comet to gather as much data as possible for the 60-hour duration of its onboard batteries.

Rosetta will continue orbiting 67P as the comet loops around the sun, coming to its closest point of some 186 million kilometres on August 13.