Ba excess in LaBaGaO4 triggers ionic conductivity together with structural disorder. A direct correlation is found between the density functional theory model energy and the pair distribution function fit residual.

A fast and exact algorithm to calculate the powder pair distribution function (PDF) for the case of periodic structures is presented. The algorithm especially improves X-ray and electron PDF calculations, and the handling of instrumental resolution functions.

The sasPDF method, an extension of the atomic pair distribution function (PDF) analysis to the small-angle scattering (SAS) regime, is presented. The method is applied to characterize the structure of nanoparticle assemblies with different levels of structural order.

The crystal structure of the organic pigment 2-monomethyl-quinacridone (Pigment Red 192, C21H14N2O2) was solved from X-ray powder diffraction data. The resulting average structure is described in space group Poverline 1, Z = 1 with the molecule on the inversion centre. The molecules are arranged in chains. The molecules, which have no inversion symmetry, show orientational head-to-tail disorder. In the average structure, the methyl group is disordered and found on both ends of the molecule with an occupancy of 0.5 each. The disorder and the local structure were investigated using various ordered structural models. All models were analysed by three approaches: Rietveld refinement, structure refinement to the pair distribution function (PDF) and lattice-energy minimization. All refinements converged well. The Rietveld refinement provided the average structure and gave no indication of a long-range ordering. The refinement to the PDF turned out to be very sensitive to small structural details, giving insight into the local structure. The lattice-energy minimizations revealed a significantly preferred local ordering of neighbouring molecules along the [0ar 11] direction. In conclusion, all methods indicate a statistical orientational disorder with a preferred parallel orientation of molecules in one direction. Additionally, electron diffraction revealed twinning and faint diffuse scattering.

The crystal structure of the nanocrystalline pigment mono­methyl-quinacridone was solved from X-ray powder data. The orientational disorder was investigated using Rietveld refinements, structure refinement to the pair-distribution function, and lattice-energy minimizations of various ordered structural models.

The new study suggests that echolocation calls also serve a social function--bats listen to the ultrasonic calls of other bats to identify roost mates, bats of the same species, members of the opposite sex and intruders to their territory.

The post Scientists find ultrasonic calls of bats also serve a social function appeared first on Smithsonian Insider.

Aldo-keto reductases (AKRs) are NADPH/NADP+-dependent oxidoreductase enzymes that metabolize an aldehyde/ketone to the corresponding alcohol. AKR4C14 from rice exhibits a much higher efficiency in metabolizing malondialdehyde (MDA) than do the Arabidopsis enzymes AKR4C8 and AKR4C9, despite sharing greater than 60% amino-acid sequence identity. This study confirms the role of rice AKR4C14 in the detoxification of methylglyoxal and MDA, and demonstrates that the endogenous contents of both aldehydes in transgenic Arabidopsis ectopically expressing AKR4C14 are significantly lower than their levels in the wild type. The apo structure of indica rice AKR4C14 was also determined in the absence of the cofactor, revealing the stabilized open conformation. This is the first crystal structure in AKR subfamily 4C from rice to be observed in the apo form (without bound NADP+). The refined AKR4C14 structure reveals a stabilized open conformation of loop B, suggesting the initial phase prior to cofactor binding. Based on the X-ray crystal structure, the substrate- and cofactor-binding pockets of AKR4C14 are formed by loops A, B, C and β1α1. Moreover, the residues Ser211 and Asn220 on loop B are proposed as the hinge residues that are responsible for conformational alteration while the cofactor binds. The open conformation of loop B is proposed to involve Phe216 pointing out from the cofactor-binding site and the opening of the safety belt. Structural comparison with other AKRs in subfamily 4C emphasizes the role of the substrate-channel wall, consisting of Trp24, Trp115, Tyr206, Phe216, Leu291 and Phe295, in substrate discrimination. In particular, Leu291 could contribute greatly to substrate selectivity, explaining the preference of AKR4C14 for its straight-chain aldehyde substrate.

David Guerit, Pauline Marie, Anne Morel, Justine Maurin, Christel Verollet, Brigitte Raynaud-Messina, Serge Urbach, and Anne Blangy

Among hematopoietic cells, osteoclasts (Oc) and immature dendritic cells (Dc) are closely related myeloid cells with distinct functions; Oc participate skeleton maintenance while Dc sample the environment for foreign antigens. Such specificities rely on profound modifications of gene and protein expression during Oc and Dc differentiation. We provide global proteomic and transcriptomic analyses of primary mouse Oc and Dc, based on original SILAC and RNAseq data. We established specific signatures for Oc and Dc including genes and proteins of unknown functions. In particular, we showed that Oc and Dc have the same α and β tubulin isotypes repertoire but that Oc express much more β tubulin isotype Tubb6. In both mouse and human Oc, we demonstrate that elevated expression of Tubb6 in Oc is necessary for correct podosomes organization and thus for the structure of the sealing zone, which sustains the bone resorption apparatus. Hence, lowering Tubb6 expression hindered Oc resorption activity. Overall, we highlight here potential new regulators of Oc and Dc biology and illustrate the functional importance of the tubulin isotype repertoire in the biology of differentiated cells.

Isabella Guardamagna, Elisabetta Bassi, Monica Savio, Paola Perucca, Ornella Cazzalini, Ennio Prosperi, and Lucia A. Stivala

Assessing DNA repair is an important endpoint to study the DNA damage response for investigating the biochemical mechanisms of this process and the efficacy of chemotherapy, which often uses DNA damaging compounds. Numerous in vitro methods to biochemically characterize DNA repair mechanisms have been developed so far. However, they show some limitations mainly due to the lack of chromatin organization. Here we describe a functional cell-free system to study DNA repair synthesis in vitro, using G1-phase nuclei isolated from human cells treated with different genotoxic agents. Upon incubation in the correspondent damage-activated cytosolic extracts, containing biotin-16-dUTP, nuclei are able to initiate DNA repair synthesis. The use of specific DNA synthesis inhibitors markedly decreased biotinylated dUTP incorporation, indicating the specificity of the repair response. Exogenously added human recombinant PCNA protein, but not the sensors of UV-DNA damage DDB2 or DDB1, stimulated UVC induced dUTP incorporation. In contrast, a DDB2^PCNA- mutant protein, unable to associate with PCNA, interfered with DNA repair synthesis. Given its responsiveness to different type of DNA lesions, this system offers an additional tool to study DNA repair mechanisms.

A novel approach for finding and evaluating structural models of small metallic nanoparticles is presented. Rather than fitting a single model with many degrees of freedom, libraries of clusters from multiple structural motifs are built algorithmically and individually refined against experimental pair distribution functions. Each cluster fit is highly constrained. The approach, called cluster-mining, returns all candidate structure models that are consistent with the data as measured by a goodness of fit. It is highly automated, easy to use, and yields models that are more physically realistic and result in better agreement to the data than models based on cubic close-packed crystallographic cores, often reported in the literature for metallic nanoparticles.

A new approach is presented to obtain candidate structures from atomic pair distribution function (PDF) data in a highly automated way. It fetches, from web-based structural databases, all the structures meeting the experimenter's search criteria and performs structure refinements on them without human intervention. It supports both X-ray and neutron PDFs. Tests on various material systems show the effectiveness and robustness of the algorithm in finding the correct atomic crystal structure. It works on crystalline and nanocrystalline materials including complex oxide nanoparticles and nanowires, low-symmetry and locally distorted structures, and complicated doped and magnetic materials. This approach could greatly reduce the traditional structure searching work and enable the possibility of high-throughput real-time auto-analysis PDF experiments in the future.

It is shown how to reconstruct the stacking sequence from the pairwise correlation functions between layers in close-packed structures. First, of theoretical interest, the analytical formulation and solution of the problem are presented when the exact pairwise correlation counts are known. In the second part, the practical problem is approached. A simulated annealing procedure is developed to solve the problem using as initial guess approximate solutions from previous treatments. The robustness of the procedure is tested with synthetic data, followed by an experimental example. The developed approach performs robustly over different synthetic and experimental data, comparing favorably with the reported methods.

When creating a System Composer architecture model, if the following functions are called with an invalid or missing stereotype, it can cause the model to get corrupted and might lead to a MATLAB crash:

• addComponent
• addPort
• connect

The positional change of nitro­gen-7 of the RNA constituent guanosine to the bridgehead position-5 leads to the base-modified nucleoside 5-aza-7-de­aza­guanosine. Contrary to guanosine, this mol­ecule cannot form Hoogsteen base pairs and the Watson–Crick proton donor site N3—H becomes a proton-acceptor site. This causes changes in nucleobase recognition in nucleic acids and has been used to construct stable `all-purine' DNA and DNA with silver-mediated base pairs. The present work reports the single-crystal X-ray structure of 7-iodo-5-aza-7-de­aza­guanosine, C10H12IN5O5 (1). The iodinated nucleoside shows an anti conformation at the glycosylic bond and an N conformation (O4'-endo) for the ribose moiety, with an anti­periplanar orientation of the 5'-hy­droxy group. Crystal packing is controlled by inter­actions between nucleobase and sugar moieties. The 7-iodo substituent forms a contact to oxygen-2' of the ribose moiety. Self-pairing of the nucleobases does not take place. A Hirshfeld surface analysis of 1 highlights the contacts of the nucleobase and sugar moiety (O—H⋯O and N—H⋯O). The concept of pK-value differences to evaluate base-pair stability was applied to purine–purine base pairing and stable base pairs were predicted for the construction of `all-purine' RNA. Furthermore, the 7-iodo substituent of 1 was functionalized with benzo­furan to detect motional constraints by fluorescence spectroscopy.

Structure-mining finds and returns the best-fit structures from structural databases given a measured pair distribution function data set. Using databases and heuristics for automation it has the potential to save experimenters a large amount of time as they explore candidate structures from the literature.

The Debye scattering equation (DSE) is generalized and augmented in order to account for moderate texture effects, yielding the differential cross section as a function of atomic coordinates and texture coefficients subject to symmetry constraints. Implications for the evaluation of the pair distribution function (PDF) as a direct transform of powder diffraction data from textured samples are also discussed.

Norbert Volkmar
Apr 24, 2020; 133:jcs243519-jcs243519
REVIEW

Assessments of a person’s ability to function at work provide important information for disability determinations, and many validated tests are available to assess work-related physical and mental functions.

Acute exacerbations of chronic obstructive pulmonary disease, or COPD, are associated with significant long-term lung function loss, according to research published online, ahead of print in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

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Nanomaterials – at a scale of one thousand times smaller than a millimetre – offer the promise of radical technological development. Many of these will improve our quality of life, and develop our economies, but all will be measured against the overarching principle that we do not make some error, and harm ourselves and our environment by exposure to new forms of hazard. This Thematic Issue explores recent developments in nanomaterials research, and possibilities for safe, practical and resource-efficient applications.

Recent research into the impact of different levels of noise on 75 volunteers reveals that disturbed sleep caused by night-time aircraft noise can damage blood vessels and increase the levels of stress hormones. As these physical changes are potential pathways to high blood pressure, heart and circulatory disease over the long term, reducing night-time aircraft noise is important for preventing cardiovascular disease in people living near airports.

Sonata Software announced that its Unified Enterprise Mobility Platform, Halosys, has been enhanced with additional features that boost optimization and usability

Low oxygen levels (‘hypoxia’) are a pressing concern for marine and freshwater ecosystems worldwide, and this may deteriorate as ocean temperatures rise. Hypoxia causes stress in organisms, which can cause reproductive impairments that persist across generations — even the offspring that have never been exposed to hypoxia. Previous studies discovered that hypoxia can disrupt sex hormones, resulting in birth defects and affecting reproduction of male fish over several generations. This study shows how hypoxia can also affect female marine medaka (Oryzias melastigma) over multiple generations — and thus may pose a significant threat to the sustainability of natural fish populations worldwide.

A synthesis of 192 studies has provided a quantitative estimate of the impact of the loss of plant biodiversity on ecosystem primary production, showing that this impact could be as great as that of other major environmental changes, such as climate warming, rising ozone levels and ocean acidification. They examined the effects of biodiversity loss on primary plant production of biomass and decomposition of plant litter, both of which underpin the carbon cycle and provision of key ecosystem services.

Woody networks in agricultural landscapes are known to harbour high intrinsic biodiversity (i.e. diversity of plant species) and functional biodiversity (i.e. ecosystem services that arise from biodiversity). In order to clarify the drivers of intrinsic and functional biodiversity in woody networks, researchers analysed the plant species diversity, pollinator resource value (PRV), and potential edibility value (PEV) of a woody network in northern Belgium. The analysis confirmed that woody elements are a rich source of intrinsic and functional biodiversity and identified several important drivers. From a policy perspective, this research highlights the value of protecting existing woody elements and thoughtfully designing and locating new ones to maximise intrinsic and functional biodiversity in the countryside.

Wastewaters from fruit-packaging plants may contain preservative chemicals. When spread onto fields, these wastewaters affect the way soil microbes cycle nitrogen, new research has found. Although this may impair crop growth, according to the authors, the results could also lead to the development of new substances that reduce nitrate run-off from agricultural land.

Of all the MATLAB or MathWorks toolbox functions that have been mentioned in this blog since 2006, imshow and imread have appeared the most. As in last week's post, they often appear together, right at the beginning: ... read more >>

You can get all the brain-boosting benefits from these nootropic foods instead of taking supplements, which aren't regulated.

A few years ago, when Janet Jackson “oopsed” her way into Super Bowl and Federal Communications Commission history, 140 million viewers of the biggest game

My Fair Trade Lady, a small shop in South Jersey, showcases fair trade items for the kitchen and beyond.

Born to drive machines　　　(3G3MX2-V1)

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Save energy and maximize performance with versatile inverter(3G3RX2)

Service Fusion is offering cutting edge fleet tracking technology to help companies increase their fleet operation efficiency and improve customer experience.

EasePDF, the best online PDF converter announces new improvements to Split PDF and Compress PDF for Better Performance. Great experience and best to use.

Internal Sale Creates Two Restaurant Brands with Dedicated Ownership, Operations, and Management Teams

The Dempster Clinic - Center for Functional Medicine is a company specialized in Functional Medicine & Naturopathic Medicine, servicing the GTA. The Dempster Clinic - Center for Functional Medicine wins this year its first Consumer Choice Award.

Speed switches can let you know if equipment is running too fast, too slow, or not at all

ABC Foundations is a drug-free educational remediation center that offers services to children with learning and academic difficulties. Some children struggle with learning and academics due to delay at the brain stem level known as NDD.

Kristin Grayce McGary's new book "Know Your Blood, Know Your Health" launches April 7, 2020

The new "USB Data Recovery Function" This functionality comes with loads of new and unique features which will provide a comprehensive solution to USB recovery issues.

A firefighter with over 20 years' experience launched a safety tool on crowd-funding site Kickstarter that can literally be a lifesaver for First Responders and Civilians alike!

Why is Gradient Descent so important in Machine Learning? Learn more about this iterative optimization algorithm and how it is used to minimize a loss function.

Roger Schwarz, author of "Smart Leaders, Smarter Teams," explains how to build trust and accountability on your team.

Margaret Parker, MD, MCCM, speaks with Meredith F. Bone, MD, MSCI

Margaret Parker, MD, MCCM, speaks with Guillaume Emeriaud, MD, PhD.

The association of dispositional optimism with health-related factors has been well established in several clinical populations, but little is known about the role of optimism in recovery after traumatic brain injury (TBI). Given the high prevalence of cognitive complaints after TBI, the present study examined the association between optimism and cognitive functioning after TBI.

We compute non-extremal three-point functions of scalar operators in $mathcal{N}=4$ super Yang-Mills at tree-level in $g_{YM}$ and at finite $N_c$, using the operator basis of the restricted Schur characters. We make use of the diagrammatic methods called quiver calculus to simplify the three-point functions. The results involve an invariant product of the generalized Racah-Wigner tensors ($6j$ symbols). Assuming that the invariant product is written by the Littlewood-Richardson coefficients, we show that the non-extremal three-point functions satisfy the large $N_c$ background independence; correspondence between the string excitations on $AdS_5 imes S^5$ and those in the LLM geometry.