Thalassemia is a group of inherited blood disorders that has a similar characteristic: defective and reduced production of haemoglobin, the iron-containing protein in red blood cells that helps in carrying oxygen throughout the body. Beta-thalassemia (BT) is one of

Following the recent demonstration of grazing-incidence X-ray fluorescence (GIXRF)-based characterization of the 3D atomic distribution of different elements and dimensional parameters of periodic nanoscale structures, this work presents a new computational scheme for the simulation of the angular-dependent fluorescence intensities from such periodic 2D and 3D nanoscale structures. The computational scheme is based on the dynamical diffraction theory in many-beam approximation, which allows a semi-analytical solution to the Sherman equation to be derived in a linear-algebraic form. The computational scheme has been used to analyze recently published GIXRF data measured on 2D Si3N4 lamellar gratings, as well as on periodically structured 3D Cr nanopillars. Both the dimensional and structural parameters of these nanostructures have been reconstructed by fitting numerical simulations to the experimental GIXRF data. Obtained results show good agreement with nominal parameters used in the manufacturing of the structures, as well as with reconstructed parameters based on the previously published finite-element-method simulations, in the case of the Si3N4 grating.

The asymmetric unit of the title compound, C8H15N3S, contains two independent mol­ecules. In both mol­ecules, the seven-membered cyclo­heptane ring adopts a chair conformation. An intra­molecular N—H⋯N hydrogen bond is observed in both mol­ecules, forming S(5) graph-set motifs. In the crystal, the two independent mol­ecules are connected through N—H⋯S hydrogen bonds, forming dimers which are in turn further connected by N—H⋯S hydrogen bonds into chains along [010].

The structure of the title compound (systematic name: N-{[(2-hy­droxy­phen­yl)methyl­idene]amino}­morpholine-4-carbo­thio­amide), C12H15N3O2S, was prev­iously determined (Koo et al., 1977) using multiple-film equi-inclination Weissenberg data, but has been redetermined with higher precision to explore its conformation and the hydrogen-bonding patterns and supra­molecular inter­actions. The mol­ecular structure shows intra­molecular O—H⋯N and C—H⋯S inter­actions. The configuration of the C=N bond is E. The mol­ecule is slightly twisted about the central N—N bond. The best planes through the phenyl ring and the morpholino ring make an angle of 43.44 (17)°. In the crystal, the mol­ecules are connected into chains by N—H⋯O and C—H⋯O hydrogen bonds, which combine to generate sheets lying parallel to (002). The most prominent contribution to the surface contacts are H⋯H contacts (51.6%), as concluded from a Hirshfeld surface analysis.

Owing to their combined open-framework structures and semiconducting properties, two-dimensional thio­stannates show great potential for catalytic and sensing applications. One such class of crystalline materials consists of porous polymeric [Sn3S72−]n sheets with molecular cations embedded in-between. The compounds are denoted R-SnS-1, where R is the cation. Dependent on the cation, some R-SnS-1 thio­stannates transition into amorphous phases upon dispersion in water. Knowledge about the fundamental chemical properties of the thio­stannates, including their water stability and the nature of the amorphous products, has not yet been established. This paper presents a time-resolved study of the transition from the crystalline to the amorphous phase of two violet-light absorbing thio­stannates, i.e. AEPz-SnS-1 [AEPz = 1-(2-amino­ethyl)­piperazine] and trenH-SnS-1 [tren = tris­(2-amino­ethyl)­amine]. X-ray total scattering data and pair distribution function analysis reveal no change in the local intralayer coordination during the amorphization. However, a rapid decrease in the crystalline domain sizes upon suspension in water is demonstrated. Although scanning electron microscopy shows no significant decrease of the micrometre-sized particles, transmission electron microscopy reveals the formation of small particles (∼200–400 nm) in addition to the larger particles. The amorphization is associated with disorder of the thio­stannate nanosheet stacking. For example, an average decrease in the interlayer distance (from 19.0 to 15.6 Å) is connected to the substantial loss of the organic components as shown by elemental analysis and X-ray photoelectron spectroscopy. Despite the structural changes, the light absorption properties of the amorphisized R-SnS-1 compounds remain intact, which is encouraging for future water-based applications of such materials.

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.

Scientists at the Smithsonian Conservation Biology Institute are celebrating the birth of a female Przewalski’s (Cha-VAL-skee) horse—the first to be born via artificial insemination. The […]

The post First wild horse species born from artificial insemination at Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.

Scientists at the Smithsonian Conservation Biology Institute in Front Royal, Va., are celebrating the anniversary of the first birth of a Przewalski’s horse by artificial […]

The post First Przewalski’s horse born by artificial insemination birthday appeared first on Smithsonian Insider.

Keepers at the Smithsonian's National Zoo perform an artificial insemination procedure on a pair of Stanley Cranes. A Stanley Crane chick was successfully hatched on May 23, 2011.

The post Bird keepers at the National Zoo demonstrate the art of artificially inseminating Stanley cranes appeared first on Smithsonian Insider.

As the Rim Fire burns deeper into Yosemite, park managers are fighting fire with fire—and one of the Smithsonian’s ForestGEO plots was caught in the […]

The post Smithsonian research plot burns in Yosemite fires appeared first on Smithsonian Insider.

Modern technologies have provided new ways for communities to engage with climate change. This study investigated the role of Internet-based tools in disseminating the findings of a climate change research project in Canada and provides insights on how best to use the Internet to communicate the outcomes of scientific research.

Research assessments should focus more on engagement processes and less on impacts and outcomes, a new study suggests. The authors examined researchers’ intended impacts and motivational factors, and stated that a change in research evaluation methods, together with better direction from university managers, could help incentivise knowledge exchange and engagement between departments and non-academic entities.

Emissions of the greenhouse gases (GHGs) tetrafluoromethane (TFM) and hexafluoroethane (HFE) reported by industry accounted for only around half actual levels measured in the atmosphere between 2002 and 2010, new research reveals. The semiconductor and aluminium production industries, the two main sources of these gases, have reported success in their voluntary efforts to control these emissions. However, this does not match ‘top-down’ atmospheric monitoring, the researchers say.

Middlesbrough stand between Watford Ladies and a place in the FAWNL Plate final after the Golden Girls swept aside Chichester City 4-0 to march into the last four.

The bad weather has caused yet more frustration for Watford Ladies after their FAWNL Plate semi-final at Middlesbrough tomorrow was postponed.

Great British Bake Off semi-finalist, Stacey Hart, has taken on a new challenge - creating delicious treats without using refined sugar. Here the baker from Hertfordshire explains what prompted her to make changes and shares her recipes.

The well-known TV personality and attorney posted a shirtless photo of himself on Twitter, but deleted it hours later.

Tesla unveils the Tesla Semi, an electric semi truck, and surprises everyone with an update to the Roadster at the same live event.

Which shortlisted bridge proposal for Tintagel Castle would King Arthur himself choose?

This teeny-tiny wooden cabin from Spain can be built in several hours (provided you can wrangle several friends to help you).

Yosemite National Park has 300 seasonal positions to fill for summer 2018. Here's how to apply.

50 technology companies will compete in the clean technology 'Oscars.'

The rare and stunningly beautiful phenomenon of Yosemite's firefall at Horsetail Falls only occurs during a two-week window in February.

Omron‘s unique Automated inspection capability ensures process quality in a mass-production environment by using Submicron CT imaging with a variety of Metrology data.(VT-X700 / VT-X900)

Tofiq Bolwala of F.A.S.T. Global Marketing hosted a motivational seminar discussing the story of basketball player, Stephen Curry's recent achievements.

Degerberg Academy of Martial Arts will host a Boxing Seminar on Sunday, June 22 at 10 a.m. for those interested in exploring and developing their boxing skills.

Firm Also Hosts Events for EmoryLaw@Work and Business Executives for National Security

ISSCC 2019 Conference, San Francisco 17-21 February 2019

You now have a simple, safe and cost-effective way to move semi-trailers in your yard without using a licensed truck driver and semi-tractor with the new V-Move™ electric trailer mover.

"Not everyone who supports BDS is an anti-Semite. However - if you look at the organisational papers of the BDS movement, and listen to what the people behind it say, it is clearly antisemitism - plain and simple."

Generators for sale in preparation for Hurricane Matthew

Sanford, Florida Power Sports dealership has 2017 Can-Am Maverick's available for sale.

Sanford, Florida Power Sports dealership participates in Yamaha pre-order program.

Sanford, Florida Power Sports Dealership Welcomes Cristy Lee for the Kickoff of "Tour de Florida"

Sanford, Florida Power Sports Dealership Continues Partnership with Kyle Farnell

The new framework uses contrastive learning to improve image analysis in unlabeled datasets.

The talk will be sometime the morning of Wed 6 May in this seminar. Title: Some statistical issues in the fight against coronavirus. Abstract: To be a good citizen, you sometimes have to be a bit of a scientist. To be a good scientist, you sometimes have to be a bit of a statistician. And […]

David Rohde points us to this new seminar series that has the following description: Machine learning is changing the world we live in at a break neck pace. From image recognition and generation, to the deployment of recommender systems, it seems to be breaking new ground constantly and influencing almost every aspect of our lives. […]

This past week was the optimal time to photograph moonbows in Yosemite Valley. I revisited photographing the moonbow at Upper Yosemite Falls as I had last year, but this time there was considerable more water and as a result the moonbow (rainbow by moonlight) was more easily seen. It was considerably larger, more vivid in color and wider arching. Conditions were great and at times a little too good as the 3 cameras I set up were completely drenched. If you’d like to read about what it took to get this photo be sure to check out my last blog post, Upper Yosemite Falls Moonbow – Getting The Shot, as it goes into a lot of detail about the hike and the challenges I faced.  If you’re curious about gear and settings this was taken with a Canon 5D Mark IV and Canon 11-24mm f/4 lens. Settings were ISO 640, 15 seconds at f/4.

We study two notions of topological entropy of correspondences introduced by Friedland and Dinh-Sibony. Upper bounds are known for both. We identify a class of holomorphic correspondences whose entropy in the sense of Dinh-Sibony equals the known upper bound. This provides an exact computation of the entropy for rational semigroups. We also explore a connection between these two notions of entropy.

We extend the analytic theory of Frobenius manifolds to semisimple points with coalescing eigenvalues of the operator of multiplication by the Euler vector field. We clarify which freedoms, ambiguities and mutual constraints are allowed in the definition of monodromy data, in view of their importance for conjectural relationships between Frobenius manifolds and derived categories. Detailed examples and applications are taken from singularity and quantum cohomology theories. We explicitly compute the monodromy data at points of the Maxwell Stratum of the A3-Frobenius manifold, as well as at the small quantum cohomology of the Grassmannian G(2,4). In the latter case, we analyse in details the action of the braid group on the monodromy data. This proves that these data can be expressed in terms of characteristic classes of mutations of Kapranov's exceptional 5-block collection, as conjectured by one of the authors.

We construct semiglobal singular spacetimes for the Einstein equations coupled to a massless scalar field. Consistent with the heuristic analysis of Belinskii, Khalatnikov, Lifshitz or BKL for this system, there are no oscillations due to the scalar field. (This is much simpler than the oscillatory BKL heuristics for the Einstein vacuum equations.) Prior results are due to Andersson and Rendall in the real analytic case, and Rodnianski and Speck in the smooth near-spatially-flat-FLRW case. Similar to Andersson and Rendall we give asymptotic data at the singularity, which we refer to as final data, but our construction is not limited to real analytic solutions. This paper is a test application of tools (a graded Lie algebra formulation of the Einstein equations and a filtration) intended for the more subtle vacuum case. We use homological algebra tools to construct a formal series solution, then symmetric hyperbolic energy estimates to construct a true solution well-approximated by truncations of the formal one. We conjecture that the image of the map from final data to initial data is an open set of anisotropic initial data.

This paper develops a method for obtaining guaranteed outer approximations for global attractors of continuous and discrete time nonlinear dynamical systems. The method is based on a hierarchy of semidefinite programming problems of increasing size with guaranteed convergence to the global attractor. The approach taken follows an established line of reasoning, where we first characterize the global attractor via an infinite dimensional linear programming problem (LP) in the space of Borel measures. The dual to this LP is in the space of continuous functions and its feasible solutions provide guaranteed outer approximations to the global attractor. For systems with polynomial dynamics, a hierarchy of finite-dimensional sum-of-squares tightenings of the dual LP provides a sequence of outer approximations to the global attractor with guaranteed convergence in the sense of volume discrepancy tending to zero. The method is very simple to use and based purely on convex optimization. Numerical examples with the code available online demonstrate the method.

Monadic second order logic can be used to express many classical notions of sets of vertices of a graph as for instance: dominating sets, induced matchings, perfect codes, independent sets or irredundant sets. Bounds on the number of sets of any such family of sets are interesting from a combinatorial point of view and have algorithmic applications. Many such bounds on different families of sets over different classes of graphs are already provided in the literature. In particular, Rote recently showed that the number of minimal dominating sets in trees of order $n$ is at most $95^{frac{n}{13}}$ and that this bound is asymptotically sharp up to a multiplicative constant. We build on his work to show that what he did for minimal dominating sets can be done for any family of sets definable by a monadic second order formula.

We first show that, for any monadic second order formula over graphs that characterizes a given kind of subset of its vertices, the maximal number of such sets in a tree can be expressed as the extit{growth rate of a bilinear system}. This mostly relies on well known links between monadic second order logic over trees and tree automata and basic tree automata manipulations. Then we show that this "growth rate" of a bilinear system can be approximated from above.We then use our implementation of this result to provide bounds on the number of independent dominating sets, total perfect dominating sets, induced matchings, maximal induced matchings, minimal perfect dominating sets, perfect codes and maximal irredundant sets on trees. We also solve a question from D. Y. Kang et al. regarding $r$-matchings and improve a bound from G'orska and Skupie'n on the number of maximal matchings on trees. Remark that this approach is easily generalizable to graphs of bounded tree width or clique width (or any similar class of graphs where tree automata are meaningful).

The present invention is directed to an electroconductive silver thick film paste composition comprising Ag, a glass frit and rhodium resinate, Cr2O3 or a mixture thereof all dispersed in an organic medium. The present invention is further directed to an electrode formed from the paste composition and a semiconductor device and, in particular, a solar cell comprising such an electrode. The paste is particularly useful for forming a tabbing electrode.

Copper(II) acetate, zinc(II) acetate, and tin(IV) acetate are weighed so that the total amount of metal ions is 2.0×10−4 mol and the molar ratio of ions is Cu:Zn:Sn=2:1:1, and 2.0 cm3 of oleylamine is added to prepare a mixed solution. Apart from this, 1.0 cm3 of oleylamine is added to 2.0×10−4 mol of sulfur powder to prepare a mixed solution. These mixed solutions are separately heated at 60° C. and mixed at room temperature. The pressure in a test tube is reduced, followed by nitrogen filling. The test tube is heated at 240° C. for 30 minutes and then allowed to stand until room temperature. The resultant product is separated into a supernatant and precipitates by centrifugal separation. The separated supernatant is filtered, methanol is added to produce precipitates. The precipitates are dissolved by adding chloroform to prepare a semiconductor nanoparticle solution.

Device for forming, on a nanowire made of a semiconductor, an alloy of this semiconductor with a metal or metalloid by bringing this nanowire into contact with electrically conductive metal or metalloid probes and Joule heating the nanowire at the points of contact with the probes so as to form an alloy such as a silicide. Application to the production of controlled-channel-length metal-silicide transistors.