Month: January 2016

Developers are ready to wait until this scene is really common enough for big game sales.

When Oculus started taking preorders for its Rift headset at $599 on Wednesday, plenty of potential consumers experienced a bit of sticker shock, thanks in part to Oculus founder Palmer Luckey's admittedly poor job of setting price expectations. While VR consumers can wait for the Rift to come down in cost, though, that launch price could have a much more immediate impact on another group: developers.

"I'm expecting a smaller audience than before [the price was revealed], which isn't good news, but it's no catastrophe either," indie VR developer E McNeill (Darknet, Tactera) told Ars in an e-mail interview.

McNeill said he had been expecting a $499 launch price for the Rift and hoped that it would somehow come in lower than that. "I think the low prices of the dev kits ($300 and $350) had anchored my expectations for the final product."

Cellular Data.

The Verge has spotted a mysterious app in the Windows Store. Published by Microsoft, the "Cellular Data" app "allows you to connect to a trusted nationwide mobile data network using only your Microsoft account."

The app, which seems to work in the UK, US, and France, says that connectivity bought this way requires no contracts or long-term commitment, allowing short-term access to LTE data at your convenience. This will be a useful addition for systems like the Surface 3, which come with integrated LTE support.

While this seems useful already, the unusual part is a sentence in the app's description: "This app is designed to work solely with specific Windows 10 devices and requires a Microsoft SIM card" (emphasis ours). The implication here is that Microsoft will be offering some kind of carrier-independent SIM card, with the app providing the necessary configuration to plumb it in to a network. This sounds similar to what Apple started doing when it updated the iPads in late 2014, though Microsoft has yet to formally announce any intent to offer anything comparable.

(credit: UVA Medicine)

People suffering from type 1 diabetes may soon be able to ditch constant finger pricks and manual insulin injections—if they have a smartphone on hand, that is.

Combined with a tiny sensor and wearable insulin pump, a smartphone can stand in for a pancreas, automatically monitoring blood-sugar levels and delivering insulin as needed, researchers report. The system, backed by a $12.6 million grant from the National Institutes of Health, will enter two final phases of international trials this year.

“We’ve been working on this specific artificial pancreas as it’s called since 2006,” lead researcher Boris Kovatchev, director of the UVA Center for Diabetes Technology, told Ars. And 10 years ago, Kovatchev said, the common wisdom in the field was that such an external system would never work. “We show that it’s not only possible, but it can run on a smartphone.”

A PET scan uses glucose with a radioactive tag to tell us which regions of the brain are most active. (credit: Oak Ridge National Lab)

Functional magnetic resonance imaging (fMRI) is used to record activity in different brain regions. When different regions exhibit simultaneous activity, we generally conclude that they are functionally connected in a network. Functional connectivity maps derived this way have revealed networks that control things like sensory processing and others that control cognition.

But this approach has a significant limitation: it's unable to reveal which brain region within the network is influencing which. Things happen so fast relative to the time resolution of the imaging that it's impossible to tell which part of the brain was active first.

Information about the direction of signaling—effective connectivity, rather than just functional connectivity—has been difficult to obtain. But now researchers in Germany have developed a method that combines the undirected functional-connectivity information from fMRI scans with energy metabolism data from PET scans, which measure glucose use, to begin to identify this effective connectivity.

An artist’s conception of the “changing-look quasar” as it appeared in early 2015. The glowing blue region shows the last of the gas being swallowed by a central black hole. The spectrum is from 2003. (credit: Dana Berry / SkyWorks Digital, Inc.; SDSS collaboration)

Here's a mystery Encyclopedia Brown probably couldn't solve: the case of the missing quasar. But astronomers appear to be up for the task. They're excited about a distant quasar that appears to have dimmed dramatically during the last decade, because it validates their understanding of these phenomena.

For a long time scientists were mystified by quasars, fairly compact objects in the sky that are extremely bright, in some cases ten or even 100 times brighter than the Milky Way Galaxy. Some scientists even speculated that these quasi-stellar objects were the other "side" of a black hole out of which all the material sucked in eventually emerged. By the 1980s, however, astronomers began to understand that quasars actually surrounded the very large, supermassive black holes at the center of galaxies. All of the electromagnetic energy quasars generate, they believed, comes from material falling into the black hole.

About 13 years ago, scientists first measured the spectrum of a quasar known as SDSS J1011+5442. To estimate the amount of gas falling into its central black hole, they looked at its hydrogen-alpha emission line. When they looked at the same quasar again in 2015, they found that emission of this gas had fallen by a factor of 55. As a result of this unprecedented decline in hydrogen-alpha emissions, it has become known as the "changing-look quasar."