Friday
Dec072012

Dear NASA, Be real! Love, the National Research Council.

by Sarah Scoles

After the federal government suggested a comprehensive and independent assessment of NASA's "strategic direction and agency management," NASA asked the National Research Council (NRC) if they would please do so. The NRC said, "Okay, NASA," and formed a 12-person committee. The report just came out, and while it does appear to be comprehensive and independent, it isn't pretty. 

The 80-page document is available for free at the National Academies Press. If you think you might want the gritty details, I recommend at least a skim--it's not all that gritty, and the committee did an effective job (and perhaps they were given a prescriptive format) of saying, "Here's what we noticed; here's why it's a problem; here's how you can fix it; also, here are some more ways you can fix it." The text is quite narrative, readable, and broken it up into sensible sections.

But because it's Friday, and you, like Rebecca Black, gotta get down on Friday and don't have time for PDFs, the highlights are below:

The committee's goal: to figure out how NASA can accomplish its goals.Credit: Sonia Kathuria.

The preface begins, "The National Aeronautics and Space Administration (NASA) is widely admired for astonishing accomplishments since its formation in 1958. Looking ahead over a comparable period of time, what can the United States and the world expect of NASA? What will be the agency’s goals and objectives, and what will be the strategy for achieving them? More fundamentally, how and by whom will the goals, objectives, and strategy be established and subsequently modified to reflect changes in science, technology, national priorities, and available resources?"

 

The committee's assessment: obstacles to NASA's accomplishment of its goals.

Let's start with the problems the committee so comprehensively and independently saw in NASA:

  1. The budget has been level, despite the increasing costs of missions.
  2. Despite the flat budget, which one might think would provide ongoing programs approximately the same $$ year-to-year, the $$ going to each program has fluctuated, leading to instability and delays.
  3. There is not enough money to accomplish the science goals set forth in the decadal survey (a document of science discovery and investigation priorities meant to guide research and budgets for periods of ten years). As a result, these goals "will now not be pursued for many years, or not at all."
  4. NASA maintains too many programs for the amount of money they have.
  5. Low funding even for programs that are funded results in stretching their timelines, which annoys everyone and also means it's impossible to start many new programs.
  6. The aeronautics portion of NASA is too small a portion of the budget to make strides that help industry and defense.
  7. Each NASA homestead (of which there are 11) does not have the ability to "manage personnel and facilities." Which means they can't tear buildings down/sell things/fire people/cancel projects easily to make their operations more cost-effective.
  8. The NASA sites do not combine capabilities as much as they could, and some of the sites do redundant things. For instance, both Dryden and Langley are working on warp drives for their vegetable-oil-powered Cylon Raiders. No, but really, "the NASA field centers do not appear to be managed as an integrated resource."
  9. The infrastructure was largely established during the Apollo program and is thus as old as "the dream."
  10. There is going to be a large time-gap in between American human space flights, and NASA does not have a strategic plan in place for rocketing humans around in the future.
  11. The human spaceflight goal that does exist was made up by the President in 2010. It's supposed to be a stepping-stone to a martian colony but is not actually a stepping-stone to anything except itself. The idea is to land people on an asteroid by 2025.
  12. Most people don't know we are supposed to send some people to an asteroid by 2025. 
  13. Most NASA employees are not supportive of sending some people to an asteroid by 2025.
  14. They're like, "That's a weird goal."
  15. NASA has no concrete plans in place to send some people to an asteroid by 2025, although they maintain that it's their near-term human spaceflight goal.
  16. I have goals too, NASA: I would like to meet a unicorn and inspire a filmmaker to make a biopic made about my unicorn and me.
  17. Though there exists a document called "The 2011 NASA Strategic Plan," it's a misleading title. The NRC committee says the plan "avoids stating any clear prioritization of the goals described therein...is broad in scope and vague on details and does not have a clearly defined plan about how to achieve the agency’s goals and objectives." Also they want to land on an asteroid and no one is sure why.

 

The committee's suggestions for how NASA can help NASA help itself:

Dear NASA, 

If you want to make yourself back into the dream machine you were in the 1960s, you need to:

Rainbow fuel exhaust will save the space program. Credit: Pretty Day Designs.

  1. Form spaceflight and science partnerships with other countries and don't be so much like, "We are the best and also the boss." Truly collaborate. This is not the Cold War.
  2. Form a consensus about where NASA should be going. This is called a "strategic vision." You may not have heard the term before, which is why we put it in quotations.
  3. Use concrete, not abstract, language when putting that consensus on a piece of paper.
  4. Make smaller objectives that lead step by step to The Future.
  5. Allocate resources in a way that reflects the steps you plan to take on your journey to The Future.
  6. Balance the distribution of resources between human spaceflight, Earth and space science, and aeronautics. 
  7. Tell everybody why you're giving various programs money and staff and equipment, so that you can be held accountable and so that you'll have to come up with an explanation for how those programs further your strategic vision.

Aside from these smaller solutions, we also offer offered four overaching options for changing NASA's structure and culture:

a) Institute an aggressive restructuring program to reduce infrastructure and personnel costs to improve efficiency.

b) Engage in and commit for the long term to more cost-sharing partnerships with other U.S. government agencies, private sector industries, and international partners.

c) Increase the size of the NASA budget.

d) Reduce considerably the size and scope of elements of NASA’s current program

e) Well, d sucks, but how about a, b, and c?

We will use vague language to say that we think you should cut staff and/or pay PhD engineers less than a living wage and/or make the James Webb Space Telescope 1/10 its planned size, but let's be real--who's going to increase the size of your budget?

 

Sincerely,

Those 12 people

PS--We love you! This is for your own good.

 

Monday
Dec032012

Bacterial Pan-Resistance: What's next?

by Brooke Napier

I gave a talk last Friday at Big Nerd Ranch (aka HighGroove Studios) about pan-resistant bacteria and innovations in the field that are making it possible to kill these pesky pathogens!

It's about 15 minutes - filled with good information & some great questions were asked!

 

2012.11.30 Tech Talk on Antibiotic Resistance from Highgroove Studios on Vimeo.

Friday
Nov302012

Fast Stats (from Space)

by Sarah Scoles

Here are some recent astronomy discoveries, turned into the kind of numbers you love to balk at:

A newly discovered quasar puts out the most energy we've ever seen anything put out, ever. And we've seen things put out plenty.

This quasar will surely qualify for state heating-bill assistance. CREDIT: L. Calçada, ESO.SDSS J1106+1939

  • has jets of material traveling away from its central black hole at 12,000 times as fast as an F22. Jet versus jet.
  • outputs 2 million-million times as much power as the Sun, an amount that would earn the this quasar a monthly power bill of $616 decillion dollars (it's a real word; I looked it up by Googling "million billion trillion quintillion"), at least at the kilowatt-hour rate on my own most recent bill.
  • It's five times as powerful as the next-most-powerful quasar.

 

 

 

In case you haven't heard, there's water water everywhere, including on Mercury. It's ice, but that still counts.

    Not a drop to drink unless you want to spend a really long time in transit. This picture shows areas of Mercury that are always in shadow (red) and the places where scientists found water-ice deposits (yellow). CREDIT: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory.

     

  • According to David Lawrence, a MESSENGER participating scientist at the Johns Hopkins University Applied Physics Laboratory, “The new data indicate the water ice in Mercury’s polar regions, if spread over an area the size of Washington, D.C., would be more than 2 miles thick." 
  • The ice likely came from a comet impact that that occurred within the last 50 million years, or sometime between when Antartica was a rain forest and when the macarena became popular.

 

The National Radio Astronomy Observatory and NASA co-released a multi-wavelength image of Hercules A, an elliptical galaxy with

The visible galaxy is the glowing yellow patch in the middle, and all the stuff being accelerated out from the black hole in the center is in purple, which represents the radio data. CREDIT: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA).

  • 1,000 times the mass of the Milky Way and
  • a central supermassive black hole 1,000 times the mass of the Milky Way's black hole, Sagittarius A*.

This image emphasizes the idea that anyone who truly wants to understand the universe has to think about all the different kinds of light waves that are out there, not just the ones our rods and cones can detect, because if we relied only on those, we would think "the galaxy" was "that yellow thing" and have no idea that those crazy huge pom-poms were coming out of it.

And isn't it interesting that the galaxy is 1000 times as massive as ours and its black hole is also 1000 times as massive as ours? 

Actually, no, that's not interesting. Astronomers have known that galaxies of a mass X tend to host black holes of mass 0.01*X.

But, guess what, that relationship doesn't always hold true, or so says another paper that came out recently. 

It doesn't look cray, but it is cray. CREDIT: NASA/ESA/Andrew C. Fabian.The newly discovered NGC 1277 is

  • 1/4 as wide as the Milky Way but has
  • a black hole 4,250 times as massive as ours at its center.
  • This object contains 14% of the galaxy's total mass. In your body, an arm accounts for about 5% of your body weight, and a leg accounts for about 9%. So if you wanted to take the black hole away from NGC 1277, that would cost it an an arm and a leg. 
  • Joke?
  • The black hole has 17 billion times as much mass as the Sun, which means 
  • its diameter is four light-days across. Not that light can travel across it.

If other such core-heavy galaxies are discovered, as the paper's authors suggested will happen in their data, astronomers will have to reconsider the "galaxy and black hole grow and then stop growing together" model.

The last statistic is based on the amount of "background" starlight there is. Astronomers looked at gamma-ray signals from extremely distant galaxies and determined, from the way the signals had dimmed, how much visible and UV light they must have interacted with. From this background they can figure out when stars were forming, how much light there is the universe, and how dense the universe is with these weirdo nuclear spheroids that keep us alive. Turns out, there is

  • one star in every 100,000,000 cubic light-years of space, which means there would be
  • 4,150 light-years between stars, if you were to spread all the stars homogeneously across the universe instead of keeping them confined to these stifling galaxies.

 

ResearchBlogging.org

Benoit C. J. Borguet, Nahum Arav, Doug Edmonds, Carter Chamberlain, & Chris Benn (2012). Major contributor to AGN feedback: VLT X-shooter observations of SIV BAL QSO outflows The Astrophysical Journal arXiv: 1211.6250v1

Lawrence, D., Feldman, W., Goldsten, J., Maurice, S., Peplowski, P., Anderson, B., Bazell, D., McNutt, R., Nittler, L., Prettyman, T., Rodgers, D., Solomon, S., & Weider, S. (2012). Evidence for Water Ice Near Mercury's North Pole from MESSENGER Neutron Spectrometer Measurements Science DOI: 10.1126/science.1229953

van den Bosch RC, Gebhardt K, Gültekin K, van de Ven G, van der Wel A, & Walsh JL (2012). An over-massive black hole in the compact lenticular galaxy NGC 1277. Nature, 491 (7426), 729-31 PMID: 23192149

Ackermann M, Ajello M, et al.  (2012). The Imprint of the Extragalactic Background Light in the Gamma-Ray Spectra of Blazars. Science (New York, N.Y.) PMID: 23118013

Tuesday
Nov202012

Where's all the old hydrogen?

by Sarah Scoles

 

No telescope will ever be able to detect cold hydrogen gas in distant radio galaxies and quasars. Even if venture capitalists funded a telescope with a 500,000,000-foot dish. Which is so big that even Australia and South Africa, put together, couldn't build it.

Why is the simplest element so undetectable in far-away, active galaxies?

Well, because it's just not there. Which is weird. Because neutral hydrogen is, like, everywhere. In all galaxies. All the time. Surrounding them and, in many cases, dwarfing the parts of a galaxy that we normally think of as "the whole galaxy." 

Recent results show that the hydrogen surrounding our galaxy is this big, while the pretty spirals we're used to think of as "our whole selves" is that tiny stuff in the middle. CREDIT: NASA/CXC/M.Weiss; NASA/CXC/Ohio State/A. Gupta,et al .It's also what begets stars. Imagine this: You are a cloud of cold hydrogen gas sitting in space. The gravitational force attracting you toward your own center is perfectly balanced with the pressure from your molecules collisions. So zen, right?

 

 

But what if that stopped being true? 

What if you became more massive, making the gravitational force stronger? (It is, after all, the holidays.) Then the gravity would not equal the pressure--gravity would win. You would collapse in on yourself. 

Way to go.

But, no, seriously--way to go. If you did it right, you'll become a star. You'll get contract and collapse and become denser and denser and hotter and hotter and eventually start to fuse your hydrogens together. You're a star!

After you form a star, you fuse heavier and heavier elements, and then, if you are massive enough (and, let's be honest, you are), you explode in a supernova and make even heavier elements. 

And more stars form from the gas cloud you made. And those stars have heavier elements, as do their planets. That's how we got all this gold bling on Earth. This picture was called "BlingBlingNeon.jpg." Credit: PSP.

So if you rewind the clock back to the beginning of the universe, it makes sense that there would be more cold hydrogen gas than there is now, since so much of it has turned into stars and into planets and into, well, the universe as we know it.

So, when, in 2008, Drs. Stephen Curran, Matthew Whiting, and J.K. Webb looked for hydrogen in these distant, energetic galaxies from the beginning of the universe, they were surprised to see...nothing.

How do you "see" hydrogen?

A neutral hydrogen atom emits a radio wave of frequencies 1420.41 MHz when its proton and its electron switch from spinning ("spinning") in the same direction to spinning in opposite directions; this is a transition from a higher energy state to a lower energy state, and the difference in energy must go somewhere (gor a more detailed answer, see this post).

Curran and associates used the Giant Metrewave Telescope in India to look for the hydrogen that they assumed would be more abundant because it hadn't yet collapsed into stars and been consumed.

But since they didn't see any, they had to form an idea as to why.

In a press release from the first paper's debut, Curran suggested that the element's absence was due to the galaxies' supermassive black holes (supermassive black holes: always causing problems): "The intense radiation from the matter accreting into the black hole in these quasars [distant galaxies with active nuclei] is extreme and we believe that this radiation is ripping the electrons from the atoms, destroying the hydrogen gas."

When hydrogen loses its electron, it is ionized and can no longer be seen by radio telescopes, because an electron that's not there can't flip its spin. The is also too hot and energetic to form stars--gravity can't win against the higher pressure and higher temperatures caused by the higher kinetic energy.

But not next time. Credit: myopera.com.

Now, four years later, Curran, Whiting, and a few others have published a model that proves, basically,

"Yep, that disruptive black hole thing was right."

These supermassive black holes are feeding on the material around them, and as the material falls in, it heats up. This hot material emits energetic radiation--specifically, ultraviolet radiation. Because these galaxies are flying away from us, carried by the expansion of the universe, the UV rays are stretched out (redshifted) down to optical wavelengths, so astronomers can literally see the light from stuff swirling around some of the first-ever huge black holes.

While this accretion process is cool, it is too hot to allow the hydrogen gas to remain neutral and form stars. And the heat doesn't just affect some of the atoms--all of them, in these distant galaxies, are ionized.

Why is this interesting?

Well, it means that a long time ago, in galaxies that are now far, far away but that tell us a lot about how galaxies in general may have been a long time ago, stars were not forming because they could not form. But they must have formed sometime, because they are here now. And there is hope for detecting star-forming hydrogen in other, less distant, less active galaxies. As Curran said, “The Square Kilometre Array will excel ... in detecting very cold gas that is too faint to be detected by optical telescopes, which must have existed to give us the stars and galaxies we see today.”

Mysteries! Of the universe. 

Curran and colleagues' conclusions have consistently created a new question for them to answer, which is exactly how science should work.


ResearchBlogging.org


Curran, S., & Whiting, M. (2012). COMPLETE IONIZATION OF THE NEUTRAL GAS: WHY THERE ARE SO FEW DETECTIONS OF 21 cm HYDROGEN IN HIGH-REDSHIFT RADIO GALAXIES AND QUASARS The Astrophysical Journal, 759 (2) DOI: 10.1088/0004-637X/759/2/117

Monday
Nov192012

Human pathogen Salmonella Typhi requires one extra protein to jump hosts

By Brooke NapierNOM NOM NOM (Hungry Hungry Macrophage)

Salmonella enterica serovar Typhi (S. Typhi), made infamous by Typhoid Mary, is a strictly human pathogen and the causative agent of typhoid fever (which still kills around 200,000 people a year).

Interestingly, we do not know what drives the species-specification of S. Typhi – even though there is a very similar mouse pathogen, Salmonella Typhimurium (Typhi-murium, murium = mouse, yah!). The species-restrictions carry all the way down to the cellular level, even though human and mouse macrophages (lean, mean innate immune system machines) are a very similar cell types, S. Typhi cannot infect mouse macrophages.

Both S. Typhi and S. Typhimurium are taken up by host innate immune cells, macrophages, and survive within an intracellular compartment called the Salmonella containing vaculole (SCV). It’s curious that S. Typhi and S. Typhimurium have such similar life cycles, but retain species-specifications.

Perhaps the key to species-restriction can be found in the differences within the SCVs?

While in the SCV, S. Typhi (human) and S. Typhimurium (mouse) communicate with host cells through a variety of proteins, called effector proteins, which are secreted from the bacteria into the host cell.

S. Typhi and S. Typhimurium have subtle differences in what effector proteins are secreted and this results in different SCV environments. Specifically, species-specific S. Typhi recruits host protein Rab29 to the SCV, however S. Typhimurium does not because it secretes an effector protein GtgE that degrades Rab29.

Whoa whoa whoa, what is a Rab protein anyway?

Rab proteins are a family of G-proteins, or guanine nucleotide-binding proteins, a superfamily of proteins involved in transmitting chemical signals throughout host cells. Specifically Rab proteins are involved in regulating steps of vesicle formation and trafficking – vesicles like the Salmonella-containing vesicles (SCVs). REALLY briefly, they are proteins that are anchored to the membranes of these vesicles in our case interact with bacterial effector protein GtgE.

Salmonella (yellow) getting taken up by a "normal macrophage". SPI-2 is a set of genes that encodes a secretion system that is depicted here secreting effector proteins, like GtgE.

Could the key to the species-restriction of S. Typhi be related to the recruitment of host proteins to the SCV?

Stefania Spanò and Jorge E. Galán found that if they expressed gtgE within the human-specific S. Typhi they could bypass host-restriction and S. Typhi could survive and replicate within macrophages and other tissues of mice.

Breaking it down:

The expression of just one single effector protein belonging to another bacterial species allowed S. Typhi to overcome host-cell restriction and survive in a nonpermissive host cell.

I guess this is particularly interesting because we always hear about flu viruses jumping from one species to the next (ex: Avian flu or Swine flu), but we rarely hear about the evolution of species-specification in bacteria.

Not only that, but papers like this have identified it’s almost as simple as viruses jumping from one species to the next – it’s a matter of one gene. Considering many species of bacteria can readily pick up floating DNA and/or exchange DNA easily with other bacterial strains and that these DNA floaters could very well encode just one gene needed for a pathogen to jump species – that’s SCARY!

Back to the story though, remember how I mentioned that GtgE acts as a protease to degrade host protein Rab29, but this degradation does not happen in S. Typhi? Perhaps…

…is the degradation of Rab29 in the SCV by GtgE responsible for host-restriction?

Oddly they found that Rab29 was not very important in host-specificity, but that another host protein, Rab32, is perhaps this is the key to host-restriction.

They first noticed that like Rab29, Rab32 was being recruited to the membrane of SCVs during infection of human macrophages with S. Typhi; however, Rab32 is not recruited to the SCV in an infection of mouse macrophages with S. Typhimurium (hint: Rab32 is most likely being degraded by GtgE, like Rab29).

Gratuitious photo of Rab32 (green) surrounding S. Typhi (red) in the mouse macrophages.

So if the presence of Rab32 in the SCV membrane might be restricting S. Typhi from surviving and replicating in mouse macrophages – what if we just delete Rab32 from mouse macrophages? Could S. Typhi then survive and replicate in mouse macrophages? Could we have found the key to host restriction?!

Eureka! They depleted Rab32 (by siRNA) from mouse macrophages and S. Typhi could not only survive but also THRIVE.

So why on Earth would Rab32, a signaling protein, be required for host-restriction?

Their hypothesis is that Rab32 has been implicated in the biogenesis of very specific cellular compartments that harbor antimicrobial peptides; therefore, perhaps Rab32 may restrict S. Typhi growth in mouse macrophages by delivering antimicrobial peptides to the SCV. They found this was actually happening, and S. Typhi was actively dying in the SCVs of mouse macrophages because of the presence of antimicrobial peptides.

Want to know something really cool? Their last few sentences:

“…a recent genome-wide association study has uncovered a genetic polymorphism (or mutation) in (human) Rab32 that is linked to increased susceptibility of Mycobacterium leprae infection. Furthermore, Rab32 has been reported to be present in the Mycobacterium tuberculosis-containing vacuole.”

In short, this could be the reason behind species-restrictions in other multiple intracellular bacterial pathogens.

 

ResearchBlogging.org Spano, S., & Galan, J. (2012). A Rab32-Dependent Pathway Contributes to Salmonella Typhi Host Restriction Science, 338 (6109), 960-963 DOI: 10.1126/science.1229224

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