There has been a lot of speculation about the causes of the 2014 North American polar vortex and some very severe winters in Eurasia. A potential culprit is the loss of Arctic sea ice. A new modeling study offers support for a linkage. In the long run Winters in the areas will warm, but in the next few decades serve Winters may become more frequent in these areas.
The Swedish biologist Kirsty Spalding and others have found that your fat-storage cells persist for about a decade, which is good news for people who struggle to lose weight. It was long thought that starvation merely deflates fat cells rather than killing them off, leaving them to fill up again like grocery bags when a dieter tires of feeling hungry. But if you can stick to a healthy regimen for long enough, it seems that you can help to stabilize your weight by outliving some of your fat cells.
Your bones and muscles are constantly remodeled. About 3 percent of the dense outermost layers of your skeleton and up to a quarter of the porous bone in the knobby parts of your limb joints are recycled every year, and experts calculate an average life cycle of a decade or so for your skeleton as a whole. The muscle cells between your ribs live for about fifteen years, according to Nicholas Wade, and the collagen cores of your tendons are essentially permanent once they finish developing during your late teens.
But Thomas seemed to be lacking all the Rh antigens. If this suspicion proved correct, it would make his blood type Rhnull – one of the rarest in the world, and a phenomenal discovery for the hospital haematologists.
Rhnull blood was first described in 1961, in an Aboriginal Australian woman. Until then, doctors had assumed that an embryo missing all Rh blood cell antigens would not survive, let alone grow into a normal, thriving adult. By 2010, nearly five decades later, some 43 people with Rhnull blood had been reported worldwide.
Hardly able to believe what she was seeing, Dr Marie-José Stelling, then head of the haematology and immunohaematology laboratory at the University Hospital of Geneva, sent Thomas’ blood for analysis in Amsterdam and then in Paris. The results confirmed her findings: Thomas had Rhnull blood. And with that, he had instantly become infinitely precious to medicine and science.
Researchers seeking to unravel the mysteries of the physiological role of the intriguingly complex Rh system are keen to get hold of Rhnull blood, as it offers the perfect ‘knockout’ system. Rare negative blood is so sought after for research that even though all samples stored in blood banks are anonymised, there have been cases where scientists have tried to track down and approach individual donors directly to ask for blood.
And because Rhnull blood can be considered ‘universal’ blood for anyone with rare blood types within the Rh system, its life-saving capability is enormous. As such, it’s also highly prized by doctors – although it will be given to patients only in extreme circumstances, and after very careful consideration, because it may be nigh on impossible to replace. “It’s the golden blood,” says Dr Thierry Peyrard, the current Director of the National Immunohematology Reference Laboratory in Paris.
Ultra high energy cosmic rays create a shower of particles when they encounter the Earth's atmosphere. The shower is large enough that distributed detector arrays are used to detect them. You need very large arrays and/or a lot of time to obtain a meaningful sample of events.
Greg noted an interesting approach that would use smartphones. The camera sensor can detect some types of shower particles if they happen to hit it. Of course the probability is small and you couldn't tell much from single events, but smartphones know where they are and what time it is and have a link to the Internet. There are also a lot of them. The scheme is to use them when they're idle, but plugged into a power source (so they don't drain the battery). When they detect energy being deposited in the camera sensor they send a report with the type of phone, time, place and rough amount of energy. The individual points are mapped by the experimentors who look for time and space correlated shower footprints.
A neat idea, but it would take a lot of cooperation to build a meaningful array. The problem is more social than technical in nature at this point.
Observing Ultra-High Energy Cosmic Rays with Smartphones
Daniel Whiteson,1 Michael Mulhearn,2 Chase Shimmin,1 Kyle Brodie,1 and Dustin Burns2
1Department of Physics and Astronomy, University of California, Irvine, CA 92697
2Department of Physics, University of California, Davis, CA
We propose a novel approach for observing cosmic rays at ultra-high energy (> 1018 eV) by re- purposing the existing network of smartphones as a ground detector array. Extensive air showers generated by cosmic rays produce muons and high-energy photons, which can be detected by the CMOS sensors of smartphone cameras. The small size and low efficiency of each sensor is compen- sated by the large number of active phones. We show that if user adoption targets are met, such a network will have significant observing power at the highest energies.
The source of ultra-high energy cosmic rays (UHECR), those with energy above 1018 eV, remains a puzzle even many decades after their discovery, as does the mecha- nism behind their acceleration. Their high energy leaves them less susceptible to bending by magnetic fields be- tween their source and the Earth, making them excel- lent probes of the cosmic accelerators which produce them [1, 2]. But the mechanism and location of this enor- mous acceleration is still not understood, despite many theoretical conjectures [3–6].
When incident on the Earth’s atmosphere, UHECRs produce extensive air showers, which can be detected via the particle flux on the ground, the flourescence in the air, or the radio and acoustic signatures. A series of dedicated detectors [7–9] have detected cosmic rays at successively higher energies, culminating in observation up to 3 · 1020 eV. The flux of particles drops precipitously above 1018 GeV, due to the suppression via interaction with the cosmic microwave background [10, 11], making observation of these particles challenging.
To accumulate a sufficient number of observed showers requires either a very long run or a very large area. Con- structing and maintaining a new detector array with a large effective area presents significant obstacles. Current arrays with large, highly-efficient devices (Auger , AGASA ) cannot grow dramatically larger without becoming much more expensive. Distributed detector ar- rays with small, cheaper devices (ERGO , etc) have the potential to grow very large, but have not achieved the size and density required to probe air showers, poten- tially due to the organizational obstacles of production, distribution and maintenance of their custom-built de- vices.
It has been previously shown that smartphones can de- tect ionizing radiation [15, 16]. In this paper, we demon- strate that a dense network of such devices has power sufficient to detect air showers from the highest energy cosmic rays. We measure the particle-detection efficiency of several popular smartphone models, which is necessary for the reconstruction of the energy and direction of the particle initiating the shower. With sufficient user adop- tion, such a distributed network of devices can observe UHECRs at rates at least comparable to conventional cosmic ray observatories. Finally, we describe the oper- ating principles, technical design and expected sensitivity of the CRAYFIS (Cosmic RAYs Found In Smartphones) detector array. Preliminary applications for Android and iOS platforms are available for testing .