The preferred orientation growth characteristics and surface roughness of polycrystalline bis­muth (Bi) thin films fabricated on glass substrates using the molecular beam epitaxy method were investigated at temperatures ranging from 18 to 150°C. The crystallization and morphology were analyzed in detail and the polycrystalline metal film structure-zone model (SZM) was modified to fit the polycrystalline Bi thin film. The boundary temperature between Zone T and Zone II in the SZM shifted to higher temperatures with the increase in film thickness or the decrease of growth rate. Furthermore, the effect of the thickness and surface roughness on the transport properties was investigated, especially for Bi thin films in Zone II. A two-transport channels model was adopted to reveal the influence of the film thickness on the competition between the metallic surface states and the semiconducting bulk states, which is consistent with the results of Bi single-crystal films. Therefore, the polycrystalline Bi thin films are expected to replace the single-crystal films in the application of spintronic devices.

3D electron diffraction (3DED) has been used to follow polymorph evolution in the crystallization of glycine from aqueous solution. The three polymorphs of glycine which exist under ambient conditions follow the stability order β < α < γ. The least stable β polymorph forms within the first 3 min, but this begins to yield the α-form after only 1 min more. Both structures could be determined from continuous rotation electron diffraction data collected in less than 20 s on crystals of thickness ∼100 nm. Even though the γ-form is thermodynamically the most stable polymorph, kinetics favour the α-form, which dominates after prolonged standing. In the same sample, some β and one crystallite of the γ polymorph were also observed.

Transforming growth factor β-1 (TGFβ-1) is a secreted signalling protein that directs many cellular processes and is an attractive target for the treatment of several diseases. The primary endogenous activity regulatory mechanism for TGFβ-1 is sequestration by its pro-peptide, latency-associated peptide (LAP), which sterically prohibits receptor binding by caging TGFβ-1. As such, recombinant LAP is promising as a protein-based therapeutic for modulating TGFβ-1 activity; however, the mechanism of binding is incompletely understood. Comparison of the crystal structure of unbound LAP (solved here to 3.5 Å resolution) with that of the bound complex shows that LAP is in a more open and extended conformation when unbound to TGFβ-1. Analysis suggests a mechanism of binding TGFβ-1 through a large-scale conformational change that includes contraction of the inter-monomer interface and caging by the `straight-jacket' domain that may occur in partnership through a loop-to-helix transition in the core jelly-roll fold. This conformational change does not appear to include a repositioning of the integrin-binding motif as previously proposed. X-ray scattering-based modelling supports this mechanism and reveals possible orientations and ensembles in solution. Although native LAP is heavily glycosylated, solution scattering experiments show that the overall folding and flexibility of unbound LAP are not influenced by glycan modification. The combination of crystallography, solution scattering and biochemical experiments reported here provide insight into the mechanism of LAP sequestration of TGFβ-1 that is of fundamental importance for therapeutic development.

X-ray reflectivity (XRR) is a powerful and popular scattering technique that can give valuable insight into the growth behavior of thin films. This study shows how a simple artificial neural network model can be used to determine the thickness, roughness and density of thin films of different organic semiconductors [diindenoperylene, copper(II) phthalocyanine and α-sexithiophene] on silica from their XRR data with millisecond computation time and with minimal user input or a priori knowledge. For a large experimental data set of 372 XRR curves, it is shown that a simple fully connected model can provide good results with a mean absolute percentage error of 8–18% when compared with the results obtained by a genetic least mean squares fit using the classical Parratt formalism. Furthermore, current drawbacks and prospects for improvement are discussed.

This paper reports an Fe-added Y2O3 crucible which is capable of balancing the solution spontaneously and is employed to effectively enhance the homogeneity of YBa2(Cu1−xFex)3O7−δ single crystals.

Single-crystalline-like thin films composed of crystallographically aligned grains are a new prototype of 2D materials developed recently for low-cost and high-performance flexible electronics as well as second-generation high-temperature superconductors. In this work, significant texture improvement in single-crystalline-like materials is achieved through growth of a 330 nm-thick silver layer.

The fossil teeth of a 15- to 18-million-year-old three-toed browsing horse, Anchitherium clarencei, were recently discovered by scientists from the Smithsonian Tropical Research Institute and the […]

The post Fossil teeth of 15-million-year-old browsing horse found in Panama Canal excavations. appeared first on Smithsonian Insider.

A new study published in the Feb. 2 issue of the Proceedings of the National Academy of Sciences indicates that forests in the Eastern United […]

The post Smithsonian ecologists discover forests are growing at a faster rate appeared first on Smithsonian Insider.

The anemones—both of which are commonly called Tealia red anemones under the species of Urticina—spawned in late April and early May, just days apart. Henley collected the eggs and sperm from the more than 2,000-gallon tank and put them together in smaller tanks to increase the chances of fertilization. After fertilization, the larvae settled and metamorphosed into a polyp.

The post National Zoo scientists successfully grow two species of anemones in aquarium tanks appeared first on Smithsonian Insider.

A team of scientists from the Smithsonian Environmental Research Center in Edgewater, Md., is taking a closer look at how rising acidification of ocean water may be impacting estuaries and near shore environments on the Chesapeake Bay

The post Oysters on floating plates help scientists study acidification and shell growth appeared first on Smithsonian Insider.

A team of scientists have found that because of this, high summer temperatures have been a strong influence in determining bill size in some birds, particularly species of sparrows that favor salt marshes.

The post It’s no sweat for salt marsh sparrows to beat the heat if they have a larger bill appeared first on Smithsonian Insider.

Using 2-dimensional and 3-dimensional CT scans, Natural History Museum anthropologists found that the brain and major organs were removed and rolls of linen filled out the abdominal cavity. This mummification method is evidence of superior embalming, indicating a person of higher status.

The post Video: A mummy ‘grows’ with CT scans and 3D digital technology appeared first on Smithsonian Insider.

A new study by astrophysicists at the University of Utah and the Smithsonian Astrophysical Observatory in Cambridge, Mass., has found a new explanation for the growth of supermassive black holes: they repeatedly capture and swallow single stars from pairs of stars that get too close.

The post Steady diet of binary star partners makes black holes grow “supermassive” appeared first on Smithsonian Insider.

A new study of Chandra data has revealed two nearby galaxies whose supermassive black holes are growing faster than the galaxies themselves.

The post Black hole growth found to be out of synch appeared first on Smithsonian Insider.

JoVonn Hill, a research associate with the Mississippi Agricultural and Forestry Experiment Station at Mississippi State University, recently borrowed 32,000 grasshoppers from the Smithsonian’s National […]

The post Mississippi State borrows grasshopper collection from Smithsonian appeared first on Smithsonian Insider.

A specimen recently pulled from deep in the southwest Atlantic may represent a new species of squid, say scientist who have studied the animal’s unusual morphology. But then again, it may not…

The post As they grow some squid change dramatically, making scientists cautious about naming new species appeared first on Smithsonian Insider.

Forget the deep forest, “today the highest densities of deer in the state of Virginia are in suburbia,” says William McShea, ecologist and research scientist at the Smithsonian’s Conservation Biology Institute in Front Royal, Va.

The post Browsing suburbia: Virginia’s parceled-up farms and forests are ideal refuge for white-tailed deer appeared first on Smithsonian Insider.

Striking Caribbean sunsets occur when particles in the air scatter incoming sunlight. But a particulate shadow over the sea may have effects underwater. A research […]

The post Human shadow cast over the Caribbean slows coral growth appeared first on Smithsonian Insider.

Astronomers are constantly on the hunt for ever-colder star-like bodies, and two years ago a new class of objects was discovered by researchers using NASA’s […]

The post Coldest brown dwarfs blur lines between stars and planets appeared first on Smithsonian Insider.

The galaxy known as M87 has a fastball that would be the envy of any baseball pitcher. It has thrown an entire star cluster toward […]

The post Star cluster thrown out of its galaxy appeared first on Smithsonian Insider.

Investigators from Rock County, Wisconsin, are one step closer to solving the mystery surrounding the death of an unknown teenager thanks to Smithsonian scientists. Christine […]

The post Smithsonian/Wisconsin police narrow search in 20 year mystery appeared first on Smithsonian Insider.

One year ago, the olinguito (Bassaricyon neblina) stepped out of the forest shadows into the spotlight and onto the pages of science—the first carnivore species […]

The post Crowdsourcing the Olinguito appeared first on Smithsonian Insider.

Every massive galaxy has a black hole at its center, and the heftier the galaxy, the bigger its black hole. But why are the two […]

The post Dark matter guides growth of supermassive black holes appeared first on Smithsonian Insider.

The clouded leopard, a native of Southeast Asia, is among the most charismatic, secretive and least understood cat species in the world. In 2002, the […]

The post Clouded leopards, from crisis to success: Q&A with Janine Brown appeared first on Smithsonian Insider.

Prehistoric human populations of hunter-gatherers in a region of North America grew at the same rate as farming societies in Europe, according to a new […]

The post Research shows same growth rate for farming, non-farming societies appeared first on Smithsonian Insider.

Today’s cutting-edge laboratories rely on ultra-cold refrigeration to keep delicate cells like sperm viable for use in the future. But a new technique using microwaves […]

The post What does candied, microwaved sperm have to do with saving endangered species? appeared first on Smithsonian Insider.

Eric Peterman, Mindaugas Valius, and Rytis Prekeris

During mitotic cell division, the actomyosin cytoskeleton undergoes several dynamic changes that play key roles in progression through mitosis. While the regulators of cytokinetic ring formation and contraction are well-established, proteins that regulate cortical stability during anaphase and telophase have been understudied. Here, we describe a role for CLIC4 in regulating actin and actin-regulators at the cortex and cytokinetic cleavage furrow during cytokinesis. We first describe CLIC4 as a new component of the cytokinetic cleavage furrow that is required for successful completion of mitotic cell division. We also demonstrate that CLIC4 regulates the remodeling of sub-plasma membrane actomyosin network within the furrow by recruiting MST4 kinase and regulating ezrin phosphorylation. This work identifies and characterizes new molecular players involved in regulating cortex stiffness and blebbing during late stages of cytokinetic furrowing.

Benjamin Ziman, Peter Karabinis, Paul Barghouth, and Nestor J. Oviedo

Nutrient availability upon feeding leads to an increase in body size in the planarian Schmidtea mediterranea. However, it remains unclear how food consumption integrates with cell division at the organismal level. Here we show that Sirtuins is evolutionarily conserved in planarians and specifically demonstrate that Sirtuin-1 (Smed-Sirt-1) regulates organismal growth by impairing both feeding behavior and intestinal morphology. Disruption of Smed-Sirt-1 with either RNAi or pharmacological treatment leads to reduced animal growth. Conversely, enhancement of Smed-Sirt-1 with resveratrol accelerates growth. Differences in growth rates were associated with changes in the amount of time to locate food and overall consumption. Furthermore, Smed-Sirt-1(RNAi) animals displayed reduced cell death and increased stem cell proliferation accompanied by impaired expression of intestinal lineage progenitors and reduced branching of the gut. Altogether, our findings indicate Sirtuin-1 is a crucial metabolic hub capable of controlling animal behavior, tissue renewal and morphogenesis of the adult intestine.

Bipasha Dey and Richa Rikhy

Cell shape morphogenesis from spherical to polygonal occurs in epithelial cell formation in metazoan embryogenesis. In syncytial Drosophila embryos, the plasma membrane incompletely surrounds each nucleus and is organized as a polygonal epithelial-like array. Each cortical syncytial division cycle shows circular to polygonal plasma membrane transition along with furrow extension between adjacent nuclei from interphase to metaphase. In this study, we assess the relative contribution of DE-cadherin and Myosin II at the furrow for polygonal shape transition. We show that polygonality initiates during each cortical syncytial division cycle when the furrow extends from 4.75 to 5.75 µm. Polygon plasma membrane organization correlates with increased junctional tension, increased DE-cadherin and decreased Myosin II mobility. DE-cadherin regulates furrow length and polygonality. Decreased Myosin II activity allows for polygonality to occur at a lower length than controls. Increased Myosin II activity leads to loss of lateral furrow formation and complete disruption of polygonal shape transition. Our studies show that DE-cadherin-Myosin II balance regulates an optimal lateral membrane length during each syncytial cycle for polygonal shape transition.

Monday, Aug. 21 was an unusual day across North America. Early in the morning, families, colleagues and tourists were searching for special solar glasses with […]

The post Crowds gather at Air and Space Museum to view solar eclipse appeared first on Smithsonian Insider.

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.

myVolcano is a crowd-sourcing app that enables you to share your photographs and descriptions of volcanic hazards, as well as collecting samples and measurements of […]

The post New: myVolcano crowd-sourcing app appeared first on Smithsonian Insider.

Judy Garland’s iconic ruby slippers from “The Wizard of Oz” are one of the most popular attractions at the National Museum of American History. But […]

The post Crowdfunding campaign to restore Ruby Slippers surpasses mark appeared first on Smithsonian Insider.

When you look at fast growing private companies in the U.S., you need look no further than a small city next to Los Angeles International Airport.

Steve Julian: Business analyst Mark Lacter, tell us about the company that's based in El Segundo.

Mark Lacter: It's called Fuhu, Steve - that might ring a bell with some parents because Fuhu is the maker of the Nabi.  The Nabi is an Android tablet for kids, and it's a very cool device that mimics a lot of the capabilities of regular tablet, including the ability to play games and get onto the Web (with controls that parents are able to set up).  Last year, they sold 1.2 million Nabis, and that helped push the El Segundo company to the very top of Inc. magazine's list of fastest-growing businesses.  That's number one on a list of 5,000 companies, with a three-year growth rate of 42,148 percent.  Or, to put it another way, company revenue was $279,000 in 2009; it was almost $118 million in 2012.  Now, by the standards of an Apple or a Samsung, those are still not huge numbers -

Julian: - and maybe that explains why there's been relatively little media coverage of this company.

Lacter: It might also explain why local tech companies in general get short shrift.  Many of them are quite successful, but they're often on the small side, and they're also privately held as opposed to publicly-traded on a stock exchange.  That's one big difference from Silicon Valley, which has so many huge public corporations: Apple, Intel, HP.  L.A. County has only six Fortune 500 companies, and not a single one devoted solely to technology.  In Silicon Valley, there are 22 in the Fortune 500.

Julian: And yet, the L.A. economy has more than held its own without those large corporations.

Lacter: Matter of fact, the accounting firm PriceWaterhouse studied more than two dozen cities around the world to determine where it was easiest to do business (that's based on factors like access to labor), and what they found - somewhat surprisingly - was that L.A. ranked ahead of both San Francisco and Tokyo.  And, you can see evidence of that with the increase in venture capital money coming into all parts of L.A.  Now, it's important to keep an eye on all these up-and-coming companies because these businesses are helping generate higher-wage jobs.  And, for an area with a still-high unemployment rate - still over 10 percent in some places -- that's a big deal.

Julian: Speaking of companies, does anyone want to buy the L.A. Times?

Lacter: The answer is yes - most recently, the controlling owner of the Dodgers, Mark Walter, said he was interested in both the Times and the Chicago Tribune (though there's no way to know whether there are actual discussions taking place).  You also have several local groups, including one that involves billionaire Eli Broad, that have been interested to one degree or another.  But what was thought would be a fairly straightforward auction process has turned enormously complicated.  It's now to the point where the Tribune board has decided spin off the papers into a separate business, and that process will take until next year to complete and could preclude any sales for quite some time after that.

Julian: So, it's Limbo-land for the Times for who knows how long.

Lacter: Steve, it's not that Tribune really wants to keep the newspapers.  But, selling them off presents huge tax implications.  Also, there are assets that the potential buyers thought would be part of the package - assets that include real estate - that Tribune wants to hold onto.  So, what's left to sell are just the newspapers themselves, and frankly, they're among the least valuable properties.

Julian: Now, last week came word that the billionaire Koch brothers, who were believed to be interested in the Tribune properties, decided not to pursue a deal...

Lacter: ...that's right, they don't consider the Times or the other dailies to be economically viable.  You might recall a bit of an outcry over the prospect of having the Kochs, who are staunch conservatives, becoming the owners of these papers.  So, they're out of the picture.  But for the L.A. Times, it's really the worst of all worlds: no new owner and no vision for recasting the paper, at least in the near term.

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.

The Windows Defender Browser Protection tech support scam is a fake web site alert that states that Windows Defender Browser Extension detected someone to hack your bank account.

This article was published first at Remove the Windows Defender Browser Protection Tech Support Scam

A new study shows that as climate change enhances tree growth in tropical forests, the resulting increase in litterfall could stimulate soil micro-organisms leading to a release of stored soil carbon.

The post Increased tropical forest growth may result in release of stored carbon in the soil appeared first on Smithsonian Insider.

Trees put on weight faster and faster as they grow older, according to a new study in the journal Nature. The finding that most trees’ […]

The post Trees grow faster and store more carbon as they age appeared first on Smithsonian Insider.

Scientists have long known that in the tropics shade-grown coffee plantations provide critical habitat for migratory and resident birds. Now a new survey conducted in […]

The post Shade-grown coffee plantations are mammal friendly as well, study shows appeared first on Smithsonian Insider.

Fort Pierce, Fla. – Fall in southern Florida is festival season: when the weather stops being oppressively hot and 70 degrees is positively autumnal.  On […]

The post Annual Smithsonian-led science festival draws crowds in Fort Pierce, Florida appeared first on Smithsonian Insider.

Internet and phone connections are essential for effective communicators and for success in business. New results from the Smithsonian Tropical Research Institute in Panama show […]

The post Ant bridges connect tropical tree crowns appeared first on Smithsonian Insider.

Caribbean coral reefs have become biologically and economically degraded habitats. The relative weight of the big factors in this ecological catastrophe–pollution, overfishing, warming and ocean […]

The post Coral reefs grow faster, healthier when parrotfish are abundant appeared first on Smithsonian Insider.

Coral reefs are home to some of the most colorful, diverse life on the planet. And yet, for all their fame as biodiversity hotspots, it’s […]

The post Coral reef eavesdropping unveils burrowed, romantic male singers appeared first on Smithsonian Insider.

A method is described for indexing grazing-incidence X-ray diffraction data of epitaxially grown thin films comprising various crystal orientations and/or polymorphs by measuring reciprocal-lattice vectors.