Forget what you thought you knew about geology. Some minerals can roll up like flaky Belgian piroulines. For the last several decades, mining operations in […]

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Oysters are keystone organisms in estuaries around the world, influencing water quality, constructing habitat and providing food for humans and wildlife. Yet their populations in […]

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At 7:05 pm (EDT), Thursday, Sept. 8, NASA plans to launch a spacecraft to a near-Earth asteroid named Bennu. Among that spacecraft’s five instruments is […]

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The last time Earth experienced both ice sheets and carbon dioxide levels within the range predicted for this century was a period of major sea […]

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To get a better idea of just what is going on with the current volcanic eruption of Kilauea on the island of Hawaii, take a […]

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Seven corrections are made and several supplementary equations are added to the article by Yoshimura [Acta Cryst. (2015), A71, 368–381].

Single-wavelength X-ray anomalous diffraction (SAD) is a frequently employed technique to solve the phase problem in X-ray crystallography. The precision and accuracy of recovered anomalous differences are crucial for determining the correct phases. Continuous rotation (CR) and inverse-beam geometry (IBG) anomalous data collection methods have been performed on tetragonal lysozyme and monoclinic survivin crystals and analysis carried out of how correlated the pairs of Friedel's reflections are after scaling. A multivariate Bayesian model for estimating anomalous differences was tested, which takes into account the correlation between pairs of intensity observations and incorporates the a priori knowledge about the positivity of intensity. The CR and IBG data collection methods resulted in positive correlation between I(+) and I(−) observations, indicating that the anomalous difference dominates between these observations, rather than different levels of radiation damage. An alternative pairing method based on near simultaneously observed Bijvoet's pairs displayed lower correlation and it was unsuccessful for recovering useful anomalous differences when using the multivariate Bayesian model. In contrast, multivariate Bayesian treatment of Friedel's pairs improved the initial phasing of the two tested crystal systems and the two data collection methods.

Under the anomalous transmission condition in the Bragg mode, X-ray interference fringes were observed between two beams with different hyperbolic trajectories in a very weakly bent plane-parallel perfect crystal with negative strain gradient. The origin of the fringes was analysed based on the dynamical theory of diffraction for a distorted crystal. In the reflected beam from the entrance surface, the interference fringes were observed between once- and twice-reflected beams from the back surface. In the transmitted beam from the back surface, the interference fringes were observed between the direct beam and once-reflected beam from the entrance surface. In the emitted beam from the lateral surface, the interference fringes were observed between the beams after different numbers of reflections in the crystal. The multiply reflected beams were formed by a combined result of long propagation length along the beam direction with large divergence of the refracted beams when the strain gradient was negative. The period of these interference fringes was sensitive to very weak strain, of the order of 10−7.

The use of strongly bent crystals in spectrometers for pulses of a hard X-ray free-electron laser is explored theoretically. Diffraction is calculated in both dynamical and kinematical theories. It is shown that diffraction can be treated kinematically when the bending radius is small compared with the critical radius given by the ratio of the Bragg-case extinction length for the actual reflection to the Darwin width of this reflection. As a result, the spectral resolution is limited by the crystal thickness, rather than the extinction length, and can become better than the resolution of a planar dynamically diffracting crystal. As an example, it is demonstrated that spectra of the 12 keV pulses can be resolved in the 440 reflection from a 20 µm-thick diamond crystal bent to a radius of 10 cm.

A crystallographic indexing algorithm, pinkIndexer, is presented for the analysis of snapshot diffraction patterns. It can be used in a variety of contexts including measurements made with a monochromatic radiation source, a polychromatic source or with radiation of very short wavelength. As such, the algorithm is particularly suited to automated data processing for two emerging measurement techniques for macromolecular structure determination: serial pink-beam X-ray crystallography and serial electron crystallography, which until now lacked reliable programs for analyzing many individual diffraction patterns from crystals of uncorrelated orientation. The algorithm requires approximate knowledge of the unit-cell parameters of the crystal, but not the wavelengths associated with each Bragg spot. The use of pinkIndexer is demonstrated by obtaining 1005 lattices from a published pink-beam serial crystallography data set that had previously yielded 140 indexed lattices. Additionally, in tests on experimental serial crystallography diffraction data recorded with quasi-monochromatic X-rays and with electrons the algorithm indexed more patterns than other programs tested.

Crystal structure identification of thin organic films entails a number of technical and methodological challenges. In particular, if molecular crystals are epitaxially grown on single-crystalline substrates a complex scenario of multiple preferred orientations of the adsorbate, several symmetry-related in-plane alignments and the occurrence of unknown polymorphs is frequently observed. In theory, the parameters of the reduced unit cell and its orientation can simply be obtained from the matrix of three linearly independent reciprocal-space vectors. However, if the sample exhibits unit cells in various orientations and/or with different lattice parameters, it is necessary to assign all experimentally obtained reflections to their associated individual origin. In the present work, an effective algorithm is described to accomplish this task in order to determine the unit-cell parameters of complex systems comprising different orientations and polymorphs. This method is applied to a polycrystalline thin film of the conjugated organic material 6,13-pentacene­quinone (PQ) epitaxially grown on an Ag(111) surface. All reciprocal vectors can be allocated to unit cells of the same lattice constants but grown in various orientations [sixfold rotational symmetry for the contact planes (102) and (102)]. The as-determined unit cell is identical to that reported in a previous study determined for a fibre-textured PQ film. Preliminary results further indicate that the algorithm is especially effective in analysing epitaxially grown crystallites not only for various orientations, but also if different polymorphs are present in the film.

Recent developments of two-color operation modes at X-ray free-electron laser facilities provide new research opportunities, such as X-ray pump/X-ray probe experiments and multiple-wavelength anomalous dispersion phasing methods. However, most existing indexing methods were developed for indexing diffraction data from monochromatic X-ray beams. Here, a new algorithm is presented for indexing two-color diffraction data, as an extension of the sparse-pattern indexing algorithm SPIND, which has been demonstrated to be capable of indexing diffraction patterns with as few as five peaks. The principle and implementation of the two-color indexing method, SPIND-TC, are reported in this paper. The algorithm was tested on both simulated and experimental data of protein crystals. The results show that the diffraction data can be accurately indexed in both cases. Source codes are publicly available at https://github.com/lixx11/SPIND-TC.

The Crab Nebula is one of the most studied objects in the night sky. First observed by Chinese astronomers in 1054 A.D., and possibly others, this supernova remnant and its neutron star have become favorite targets for amateur and professional astronomers alike. The Chandra X-Ray Observatory is operated for NASA by the Smithsonian Astrophysical Observatory in Cambridge, Mass.

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Dr. JoGayle Howard of the Smithsonian's National Zoo discusses her work to breed and study one of the world's most endangered cats, the clouded leopard. More about the National Zoo's work to save clouded leopards: http://nationalzoo.si.edu/SCBI/ReproductiveScience/ConsEn...
http://nationalzoo.si.edu/support/annualappeal/cloudedleo... ... (more info)

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The post Roland Kays, curator of mammals at the New York State Museum, discusses a new Smithsonian Website for sharing camera-trap images of wild animals appeared first on Smithsonian Insider.

The post Belize’s South Water Caye Marine Reserve protects biodiversity of Belizean Barrier Reef appeared first on Smithsonian Insider.

If a supernova vaporized Earth’s ozone layer, what would happen to life in the ocean? Smithsonian biologist Pat Neale shows how UV rays could harm […]

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The moon passed between the Earth and the sun on Thursday, Oct. 23. While avid stargazers in North America looked up to watch the spectacle, the […]

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Jan. 6, 2015—As the year’s first blanket of snow coated the Washington, D.C. area today, giant panda Bao Bao at the Smithsonian’s National Zoological Park […]

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Inupiaq artist and teacher Holly Nordlum visited the National Museum of the American Indian to study Arctic objects and archival photographs in the museum’s collections. […]

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“The Outwin 2016: American Portraiture Today” exhibition is on view at the Smithsonian’s National Portrait Gallery from March 12, 2016 – January 8, 2017. The Outwin […]

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Happy Holidays from the Smithsonian’s National Air and Space Museum!

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Ohkay Owingeh from Adventure Pictures on Vimeo. Currently featured in the exhibition “By the People” at the Cooper Hewitt, Smithsonian Design Museum in New York City […]

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At age 19, athlete Amy Purdy had both legs amputated below the knee due to a sudden illness that culminated in septic shock. Two years […]

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US Airways Flight 1549 crashed into the Hudson River on January 15, 2009. Learn how the events of that day unfolded and what happened to […]

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Explore a “day in the life” of the Smithsonian American Art Museum, the nation’s first collection of American art and home to one of the […]

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New on Smithsonian Folkways Recordings: This official music video is for “Ripest of Apples” by Anna & Elizabeth, from the new album ‘The Invisible Comes […]

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We used to make a big deal out of Casual Fridays at work.  But now that we're entering the dog days of summer, is anyone dressing up?

Mark Austin Thomas: Business analyst Mark Lacter, dare I ask what you're wearing?

Mark Lacter: This is radio for a reason, Mark!  And certainly, don't ask that question at the L.A. Daily Journal newspaper, which recently issued a memo that laid down the law on what's not considered appropriate attire.  As in, no jeans, no sneakers (except for messengers), no sandals or flip-flops, no halter tops, no spaghetti straps, no tee-shirts.  Also, no shorts, leggings, or exercise pants.  And, if you don't measure up, you may be sent home to change clothes - without pay for the time you've missed.  Now, to be fair, the Daily Journal is a legal newspaper, and law firms - along with the courts - remain kind of a bastion for traditional business attire.

Thomas: And that means jackets and ties for men...?

Lacter: ...and skirt suits and business dresses for women.  It's the same deal for many offices in New York and Chicago.  Matter of fact, dressing down is still not especially popular in many parts of the country, according to a new survey I came across.  More than half of the respondents say it suggests an employee doesn't have respect for the workplace.  In other words, not a team player.

Thomas: But L.A. has this huge creative community where jeans and tee-shirts are almost part of the uniform.

Lacter: Yeah, the only people wearing suits at these places are the high-level executives who are actually called "suits."  This has been true in Hollywood for years, but now you're seeing it with the growth of tech companies.  Imagine how confusing it must be for an attorney who wears the standard business uniform, and who has one of these companies as his client.  And, maybe that's the point - there is no single workplace culture, even within the companies themselves.

Thomas: Is being comfortable just not on the radar at these places?

Lacter: Well, not to pick on the Daily Journal, but so what if someone who is stuck in front of a computer all day wants to be a little more comfortable in jeans?  Will the world as we know it come to a halt?  You know, the workplace is far different than it was even 10 years ago.  People are doing their jobs in all sorts of ways, whether it's working from home, or as independent contractors.  And, this is really all about common sense - so, maybe it's time the stick-in the-muds realized as much.

Thomas: Attire aside, how is the workplace itself changing?

Lacter: Some of those downtown law firms have been cutting back, which means that they don't need as much space.  Not every attorney needs a giant office.  Same with the downtown accounting firms - when folks do go to work, the office may include a fancy kitchen, a ping pong table, workstations that double as treadmills, a place to do yoga or even to take a nap.

Thomas: All this is supposed to boost productivity...

Lacter: ...which it probably does, though you do have to wonder whether having a yoga room really enhances output, or is just a way of keeping employees from not taking a job somewhere else.  My favorite perk, and I say that facetiously, is the office kegerator, which not only seems like a dumb idea, but a great way for a company to get sued if somebody has one too many.

Thomas: Quickly Mark, any news in the dispute between CBS and Time Warner Cable?

Lacter: Not good news.  Time Warner Cable offered what it said were two possible solutions to the standoff, but CBS has came back and called it a sham.  Time Warner Cable subscribers have been without CBS programming since Friday, which is already going on longer than analysts had first expected.  The fight is over re-transmission fees - the amount of money that a programmer receives from a distributor- in this case, Time Warner Cable.  CBS apparently wants a big increase, and Time Warner Cable doesn't want to pay.

Mark Lacter is a contributing writer for Los Angeles Magazine and writes the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.

Businesses are cutting back on hours to avoid having to provide health care coverage under the new Affordable Care Act.

Steve Julian: Business analyst Mark Lacter, who's affected here?

Mark Lacter: Thirty hours a week is the magic number for workers to be considered full time under the new law.  If a business has 50 or more full-time employees, health care coverage has to be provided.  Except that a lot business owners say that the additional cost is going to be a financial killer, so instead, some of them have been cutting back hours to below that 30-hour threshold.  More than 200,000 Californians are at risk of losing hours from the health care law - that according to one study.

Julian: What kinds of businesses are doing this?

Lacter: Restaurant chains have received much of the attention, but the city of Long Beach, as an example, is going to reduce hours for a couple of hundred of its workers.  And, last week came word that the L.A.-based clothing chain Forever 21 will cut some of its full-time employees to a maximum 29-and-a-half hours a week, and classify them as part time.  That touched off an outcry on the Internet - people were saying that Forever 21 was being unfair and greedy - though the company says that only a small number of employees are affected, and that its decision has nothing to do with the Affordable Care Act.  There's really no way to know - Forever 21 is a private company, which means it's not obligated to disclose a whole lot.  What we do know is that those people will be losing their health care coverage.

Julian: And, the ultimate impact on businesses and workers?

Lacter: Steve, you're looking at several years before the picture becomes clear.  Here in California, workers not eligible for health care through their employer can get their own individual coverage, and if their income levels are not over a certain amount, they'd be eligible for Medicaid.  And, let's not forget many businesses already provide coverage for their employees.  So, lots of rhetoric - but, not many conclusions to draw from, which does make you wonder why so many business owners are unwilling to at least give this thing a chance.  Just doesn't seem to be much generosity of spirit for their workers, not to mention any recognition that if people can go to a doctor instead of an emergency room we'd probably all be better off.

Julian: Health care is far from the only controversy for Forever 21, true?

Lacter: In some ways, it's one of the biggest Southern California success stories.  Don Chang emigrated here in 1981 from Korea at the age of 18, opened his first store in Highland Park three years later (it was called Fashion 21), and he never looked back.  Today, revenues are approaching $4 billion.  But, the guy must have some pretty hefty legal bills because his company has been accused of all kinds of workplace violations.  The lawsuits alleged that workers preparing items for the Forever 21 stores didn't receive overtime, that they didn't get required work breaks, that they received substandard wages, and that they worked in dirty and unsafe conditions - sweatshop conditions, essentially.

Julian: Are most of their claims settled out of court?  You don't hear much about them.

Lacter: They are, which means there's usually a minimal amount of media coverage.  If a privately held company decides to keep quiet by not releasing financial results or other operational information, there's not likely to be much of a story - unlike what happens with a company like Apple, which is always under scrutiny.  Sometimes, plaintiffs will try to organize class-action suits, but that's extremely tough when you're dealing with low-wage workers who are often very reluctant to get involved because of their legal status.  And, let's not forget that Forever 21 - like any low-cost retailer - is simply catering to the demand for cheap, stylish clothes that are made as quickly as possible.

Julian: I guess you can't make that happen when wages and benefits are appreciably higher than your competition.

Lacter: The next time you walk into a Forever 21 store and wonder how prices can be so reasonable, that's how.

Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.

Yesterday may have been a holiday on paper, but if you were navigating LA's major freeways, there was no sign people had the day off.

Steve Julian: Business analyst Mark Lacter, is this more evidence that Southern California traffic getting worse?

Mark Lacter: Steve, L.A. continues to be the most clogged-up city in the U.S. - according to something called the TomTom Traffic Index - with commuters caught up in delays, on average, 35 percent of the time.  Or, to put it another way, L.A. commuters are in congestion up to 40 minutes of each hour they're driving.  The worst time of the week to commute is Thursday night; that's when there's congestion more than 80 percent of the time.  Monday morning commutes are the lightest.

Julian: After L.A., where should you not live if congestion bugs you?

Lacter: The next worst cities in the U.S. are San Francisco, Honolulu, Seattle, and San Jose.  Now, the Census Bureau comes up with its own commuting surveys, and if you compare the most recent numbers with those back in 2000, you'll see that things aren't all that different.  Matter of fact, the percentage of commuters driving alone to work actually increased a little over the last decade to 72 percent, while the percentage of those carpooling has declined.

Julian: What about public transit?

Lacter: Well, the numbers are up slightly from 2000, but only to 7.3 percent of all commuters.  So, even assuming that the number inches up in the next couple of years when the Expo Line extends into Santa Monica, it's still a smallish piece of the pie.  And, since many of the other public transit projects being planned are decades away from being completed, those numbers might not change much.  One other thing, Steve: less than 1 percent of all L.A. commuters bike to work, which would throw cold water on the idea that biking in L.A. is becoming a popular way of getting to the office.

Julian: People just prefer commuting by car…

Lacter: It remains the most convenient way of getting around - despite the congestion.  New car sales are up 14 percent through the first nine months of the year in Southern California.  Add to that are generally affordable gas prices (they've been especially low in the last few weeks).  In other parts of the world, congestion is considered a good thing because it means that the economy is doing well.  Which explains that while L.A. is the most congested city in the U.S., it doesn't rank among the 10 around the world.  On that front, Moscow is tops, followed by Istanbul, and Rio de Janeiro.

Julian: What about driverless cars?

Lacter: Well, these vehicles hold the most promise for reducing accidents, lowering travel times, and improving fuel economy - and you don't have to give up your car.  Actually, a lot of the technology is already in place - that includes stuff like radar-based cruise control, and devices that keep you at a safe distance from the car in front of you.  The trick, of course, is taking these individual capabilities and integrating them into an entirely driverless car.  Several car companies say they could be ready to start selling by 2020, with Google saying that its car could be ready even sooner.

Julian: Is that realistic?

Lacter: Who knows?  But even if the dates can be met - and that's a big if, considering how complex these systems are - legislatures will have to determine, among other things, whether vehicles can be fully autonomous (meaning that you can curl up and take a nap while the computer is driving by itself).  Or, whether they will only be semi-autonomous, which would be like an airline crew using automatic pilot, but always prepared to take over the controls.

Julian: Is that a liability issue?

Lacter: Yes - if something does go wrong, who will get the blame?  The owner of the vehicle?  The carmaker?  The suppliers of the car companies?  These questions might take years to get resolved in the courts - and even then, it could be years before the percentage of these vehicles on the road is large enough to truly have an impact.  But, considering that most commuters aren't willing to give up their cars, this would seem to be the most exciting, most desirable idea.  One day.

Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.

HD Video Player PUP is a potentially unwanted program that in itself is not malicious, but if installed indicates that you most likely have malware or other potentially uwnanted programs installed as well.

This article was published first at Remove the HD Video Player PUP

New results from a massive study at the Smithsonian Tropical Research Institute show that interactions among community members play an important role in determining which organisms thrive.

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Current plans to protect the Chesapeake Bay include planting trees along hundreds of miles of streams that empty into the Bay. This study provides realistic limits for how much these buffers might further reduce nitrate pollution, and it helps identify where buffer restoration can offer the greatest additional nitrate removal.

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