bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman evidence for absence of phase transitions in negative differential resistance thin film devices of niobium dioxide
Authors: Fakih Ali , Shinde Onkar , Biscaras Johan , Shukla Abhay
Published: February 2020

We fabricate NbO2 thin films and measure their transport properties in simple devices. These could be potential components of future memristor devices because of peculiar conductivity variations observed as a function of device current. We find that threshold switching effects observed in the voltage control regime are better viewed in the current controlled regime where they can be understood in terms of a negative differential resistance phenomenon. No electronic or structural phase change is observed in the NbO2 thin films in this regime in the steady state, notably with in situ Raman measurements. In particular, both crystalline and amorphous films remain insulating since their resistance always decreases with an increase in temperature. However, a large decrease in resistivity corresponding to negative differential resistance is observed as current in the devices increases. Temperature is the parameter which induces this change in resistivity through thermal activation of carriers, confirming recent understanding of the phenomenon. Temperature changes are locally induced because of the power dissipated by the current in the device and the intrinsically low thermal conductivity of NbO2. This is confirmed by parameters extracted from the simulation of the phenomenon with different transport models. However, the simplest thermal activation model accounts for the observations in non-nanometric devices without the need for invoking more complex models. Finally, pulsed current can be used to provoke a structural, amorphous to crystalline phase transition in amorphous samples through a sudden local increase in temperature.
Light-induced transition between the strong and weak coupling regimes in planar waveguide with GaAs/AlGaAs quantum well
Authors: Shapochkin P. Yu. , Lozhkin M. S. , Solovev I. A. , Efimov Yu. P. , Eliseev S. A. , Lovtcius V. A. , Kapitonov Yu. V.
Published: February 2020

Exciton-polaritons in planar waveguides are of great interest for application in polariton circuits due to the large polariton group velocity in the plane of the waveguide. We demonstrate the ability to control the exciton-polariton coupling by light in an AlGaAs-based planar waveguide with GaAs/AlGaAs quantum well. The transition between strong and weak coupling regimes observed with increasing light intensity is explained by the increase in exciton mode losses due to the quantum well charging. This assumption is confirmed by the reflection spectroscopy with resonant illumination.
Wideband detection of electromagnetic signals by high-Tc Josephson junctions with comparable Josephson and thermal energies
Authors: Pavlovskiy V. V. , Gundareva I. I. , Volkov O. Y. , Divin Y. Y.
Published: February 2020

Detection mechanisms in Josephson junctions with energies Ej comparable to thermal energies kT have been studied. The responses ΔV of YBa2Cu3O7−x bicrystal junctions to monochromatic radiation with frequencies f ranging from 94 GHz to 3.1 THz can be described in terms of classical rectification on a static nonlinear V–I curve at low frequencies and frequency modulation of the ac Josephson current at high frequencies, with an interplay between these mechanisms at intermediate frequencies. An electrical noise-equivalent power of (9 ± 3) × 10−15 W/Hz1/2, a responsivity of (3.4 ± 0.5) × 105 V/W, and a dynamic power range of 5 × 104 have been demonstrated for the square-law classical detection of 94 GHz radiation with the junctions at 50 K. The effect of background radiation on the V–I curves of YBa2Cu3O7−x bicrystal junctions was found to have an optical noise-equivalent temperature of ≤30 mK/Hz1/2. The main contribution to the effect comes from the interplay between the classical and Josephson detection mechanisms. The spectral and power dependencies of the responses ΔV of Josephson junctions have been numerically simulated within the resistively shunted junction model at various values of kT/Ej, and the results are in acceptable agreement with the experimental data.
The aging skin microenvironment dictates stem cell behavior
Authors: Ge Yejing , Miao Yuxuan , Gur-Cohen Shiri , Gomez Nicholas , Yang Hanseul , Nikolova Maria , Polak Lisa , Hu Yang , Verma Akanksha , Elemento Olivier , Krueger James G. , Fuchs Elaine
Published: February 2020

Aging manifests with architectural alteration and functional decline of multiple organs throughout an organism. In mammals, aged skin is accompanied by a marked reduction in hair cycling and appearance of bald patches, leading researchers to propose that hair follicle stem cells (HFSCs) are either lost, differentiate, or change to an epidermal fate during aging. Here, we employed single-cell RNA-sequencing to interrogate aging-related changes in the HFSCs. Surprisingly, although numbers declined, aging HFSCs were present, maintained their identity, and showed no overt signs of shifting to an epidermal fate. However, they did exhibit prevalent transcriptional changes particularly in extracellular matrix genes, and this was accompanied by profound structural perturbations in the aging SC niche. Moreover, marked age-related changes occurred in many nonepithelial cell types, including resident immune cells, sensory neurons, and arrector pili muscles. Each of these SC niche components has been shown to influence HF regeneration. When we performed skin injuries that are known to mobilize young HFSCs to exit their niche and regenerate HFs, we discovered that aged skin is defective at doing so. Interestingly, however, in transplantation assays in vivo, aged HFSCs regenerated HFs when supported with young dermis, while young HFSCs failed to regenerate HFs when combined with aged dermis. Together, our findings highlight the importance of SC:niche interactions and favor a model where youthfulness of the niche microenvironment plays a dominant role in dictating the properties of its SCs and tissue health and fitness.
Dinoflagellates with relic endosymbiont nuclei as models for elucidating organellogenesis
Authors: Sarai Chihiro , Tanifuji Goro , Nakayama Takuro , Kamikawa Ryoma , Takahashi Kazuya , Yazaki Euki , Matsuo Eriko , Miyashita Hideaki , Ishida Ken-ichiro , Iwataki Mitsunori , Inagaki Yuji
Published: February 2020

Nucleomorphs are relic endosymbiont nuclei so far found only in two algal groups, cryptophytes and chlorarachniophytes, which have been studied to model the evolutionary process of integrating an endosymbiont alga into a host-governed plastid (organellogenesis). However, past studies suggest that DNA transfer from the endosymbiont to host nuclei had already ceased in both cryptophytes and chlorarachniophytes, implying that the organellogenesis at the genetic level has been completed in the two systems. Moreover, we have yet to pinpoint the closest free-living relative of the endosymbiotic alga engulfed by the ancestral chlorarachniophyte or cryptophyte, making it difficult to infer how organellogenesis altered the endosymbiont genome. To counter the above issues, we need novel nucleomorph-bearing algae, in which endosymbiont-to-host DNA transfer is on-going and for which endosymbiont/plastid origins can be inferred at a fine taxonomic scale. Here, we report two previously undescribed dinoflagellates, strains MGD and TGD, with green algal endosymbionts enclosing plastids as well as relic nuclei (nucleomorphs). We provide evidence for the presence of DNA in the two nucleomorphs and the transfer of endosymbiont genes to the host (dinoflagellate) genomes. Furthermore, DNA transfer between the host and endosymbiont nuclei was found to be in progress in both the MGD and TGD systems. Phylogenetic analyses successfully resolved the origins of the endosymbionts at the genus level. With the combined evidence, we conclude that the host–endosymbiont integration in MGD/TGD is less advanced than that in cryptophytes/chrorarachniophytes, and propose the two dinoflagellates as models for elucidating organellogenesis.
Estimation and model selection in general spatial dynamic panel data models
Authors: Jin Baisuo , Wu Yuehua , Rao Calyampudi Radhakrishna , Hou Li
Published: February 2020

Significance

Spatial dynamic panel data modeling is widely used in many areas of science and engineering such as environmental science, epidemiology, economics, and sociology. The ordinary least-squares estimation of parameters of a general spatial dynamic panel data model is inconsistent in general because the spatially lagged dependent variables are typically correlated with the error term. Other estimations based on maximum likelihood or generalized moments are rather complicated. In this paper, we propose an efficient, distribution-free least-squares estimation method that utilizes the eigendecomposition of a weight matrix. We also present a model selection procedure based on the proposed method. Our approach is very powerful compared to the well-known instrumental variable techniques. Its applicability is demonstrated via a high-dimensional data example.
Bioinspired underwater locomotion of light-driven liquid crystal gels
Authors: Shahsavan Hamed , Aghakhani Amirreza , Zeng Hao , Guo Yubing , Davidson Zoey S. , Priimagi Arri , Sitti Metin
Published: February 2020

Significance

Untethered dynamic shape programming and control of soft materials have significant applications in technologies such as soft robots, medical devices, organ-on-a-chip, and optical devices. Here, we present a solution to remotely actuate and move soft materials underwater in a fast, efficient, and controlled manner using photoresponsive liquid crystal gels (LCGs). LCG constructs with engineered molecular alignment show a low and sharp phase-transition temperature and experience considerable density reduction by light exposure, thereby allowing rapid and reversible shape changes. We demonstrate different modes of underwater locomotion, such as crawling, walking, jumping, and swimming, by localized and time-varying illumination of LCGs. The diverse locomotion modes of smart LCGs can provide a new toolbox for designing efficient light-fueled soft robots in fluid-immersed media.
Footprints of natural selection at the mannose-6-phosphate isomerase locus in barnacles
Authors: Nunez Joaquin C. B. , Flight Patrick A. , Neil Kimberly B. , Rong Stephen , Eriksson Leif A. , Ferranti David A. , Rosenblad Magnus Alm , Blomberg Anders , Rand David M.
Published: February 2020

The mannose-6-phosphate isomerase (
Mpi
) locus in
Semibalanus balanoides
has been studied as a candidate gene for balancing selection for more than two decades. Previous work has shown that
Mpi
allozyme genotypes (fast and slow) have different frequencies across Atlantic intertidal zones due to selection on postsettlement survival (i.e., allele zonation). We present the complete gene sequence of the
Mpi
locus and quantify nucleotide polymorphism in
S. balanoides
, as well as divergence to its sister taxon
Semibalanus cariosus
. We show that the slow allozyme contains a derived charge-altering amino acid polymorphism, and both allozyme classes correspond to two haplogroups with multiple internal haplotypes. The locus shows several footprints of balancing selection around the fast/slow site: an enrichment of positive Tajima’s D for nonsynonymous mutations, an excess of polymorphism, and a spike in the levels of silent polymorphism relative to silent divergence, as well as a site frequency spectrum enriched for midfrequency mutations. We observe other departures from neutrality across the locus in both coding and noncoding regions. These include a nonsynonymous trans-species polymorphism and a recent mutation under selection within the fast haplogroup. The latter suggests ongoing allelic replacement of functionally relevant amino acid variants. Moreover, predicted models of
Mpi
protein structure provide insight into the functional significance of the putatively selected amino acid polymorphisms. While footprints of selection are widespread across the range of
S. balanoides
, our data show that intertidal zonation patterns are variable across both spatial and temporal scales. These data provide further evidence for heterogeneous selection on
Mpi
.
Joint profiling of chromatin accessibility and CAR-T integration site analysis at population and single-cell levels
Authors: Wang Wenliang , Fasolino Maria , Cattau Benjamin , Goldman Naomi , Kong Weimin , Frederick Megan A. , McCright Sam J. , Kiani Karun , Fraietta Joseph A. , Vahedi Golnaz
Published: February 2020

Chimeric antigen receptor (CAR)-T immunotherapy has yielded impressive results in several B cell malignancies, establishing itself as a powerful means to redirect the natural properties of T lymphocytes. In this strategy, the T cell genome is modified by the integration of lentiviral vectors encoding CAR that direct tumor cell killing. However, this therapeutic approach is often limited by the extent of CAR-T cell expansion in vivo. A major outstanding question is whether or not CAR-T integration itself enhances the proliferative competence of individual T cells by rewiring their regulatory landscape. To address this question, it is critical to define the identity of an individual CAR-T cell and simultaneously chart where the CAR-T vector integrates into the genome. Here, we report the development of a method called EpiVIA (
https://github.com/VahediLab/epiVIA
) for the joint profiling of the chromatin accessibility and lentiviral integration site analysis at the population and single-cell levels. We validate our technique in clonal cells with previously defined integration sites and further demonstrate the ability to measure lentiviral integration sites and chromatin accessibility of host and viral genomes at the single-cell resolution in CAR-T cells. We anticipate that EpiVIA will enable the single-cell deconstruction of gene regulation during CAR-T therapy, leading to the discovery of cellular factors associated with durable treatment.
Exploring long-range cooperativity in the 20S proteasome core particle from
Thermoplasma acidophilum
using methyl-TROSY–based NMR
Authors: Rennella Enrico , Huang Rui , Yu Zanlin , Kay Lewis E.
Published: February 2020

Significance

The proteasome is a molecular machine that plays a key role in maintaining the healthy function of cells through eliminating protein molecules that are no longer required or that are damaged. Proteasome function is, in part, regulated through the binding of other protein components that turn on pathways of communication between the sites of binding and distal regions of the proteasome that are responsible for its catalytic activity. Understanding how information is communicated between far-removed sites in the proteasome, and the extent of the pathway of communication, is a key first step in the design of molecules that can regulate its activity, with potentially important implications in the fight against certain cancers and neurodegenerative diseases.
Trinuclear copper biocatalytic center forms an active site of thiocyanate dehydrogenase
Authors: Tikhonova Tamara V. , Sorokin Dimitry Y. , Hagen Wilfred R. , Khrenova Maria G. , Muyzer Gerard , Rakitina Tatiana V. , Shabalin Ivan G. , Trofimov Anton A. , Tsallagov Stanislav I. , Popov Vladimir O.
Published: February 2020

Biocatalytic copper centers are generally involved in the activation and reduction of dioxygen, with only few exceptions known. Here we report the discovery and characterization of a previously undescribed copper center that forms the active site of a copper-containing enzyme thiocyanate dehydrogenase (suggested EC 1.8.2.7) that was purified from the haloalkaliphilic sulfur-oxidizing bacterium of the genusThioalkalivibrioubiquitous in saline alkaline soda lakes. The copper cluster is formed by three copper ions located at the corners of a near-isosceles triangle and facilitates a direct thiocyanate conversion into cyanate, elemental sulfur, and two reducing equivalents without involvement of molecular oxygen. A molecular mechanism of catalysis is suggested based on high-resolution three-dimensional structures, electron paramagnetic resonance (EPR) spectroscopy, quantum mechanics/molecular mechanics (QM/MM) simulations, kinetic studies, and the results of site-directed mutagenesis.
CCM.FF-K3.2011.1: CIPM key comparison of air speed, 0.5 m/s to 40 m/s
Authors: Müller Harald , Caré Isabelle , Popov Konstantin
Published: February 2020

The bilateral key comparison between PTB and VNIIM (CCM.FF-K3.2011.1) was performed as direct follow-up of the CIPM air speed key comparison (CCM.FF-K3.2011) which was organized to determine the degree of equivalence of the national standards for air speed covering the range 0.5 m/s to 40 m/s under ambient conditions. An ultrasonic anemometer and a laser Doppler anemometer were used as transfer standards. The measurement procedures in the technical protocol as well as the transfer standards for the bilateral key comparison (CCM.FF-K3.2011.1) were identical to the CIPM Key Comparison (CCM.FF-K3.2011) with nine participants from three RMOs. Thus, the measurement results were directly linked to the key comparison reference values published in the final report of the (CCM.FF-K3.2011) for each standard and each air speed separately. The degree of equivalence of each result with the key comparison reference value (KCRV) was calculated. All reported results of the bilateral key comparison were consistent with the KCRV results of the (CCM.FF-K3.2011).

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with NIST, June 2019
Authors: Viallon Joële , Idrees Faraz , Moussay Philippe , Wielgosz Robert , Norris James E , Hodges Joseph T
Published: February 2020

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the National Institute of Standards and Technology (NIST) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Towards a morphology of cobalt nanoparticles: size and strain effects
Authors: Farkaš Barbara , de Leeuw Nora H
Published: February 2020

Cobalt nanoparticles with diameters of 8 nm have recently shown promising performance for biomedical applications. However, it is still unclear how the shape of cobalt clusters changes with size when reaching the nanoparticle range. In the present work, density functional theory calculations have been employed to compare the stabilities of two non-crystalline (icosahedron and decahedron) shapes, and three crystalline motifs (hcp, fcc, and bcc) for magic numbered cobalt clusters with up to 1500 atoms, based on the changes in the cohesive energies, coordination numbers, and nearest-neighbour distances arising from varying geometries. Obtained trends were extrapolated to a 104 size range, and an icosahedral shape was predicted for clusters up to 5500 atoms. Larger sized clusters adopt hcp stacking, in correspondence with the bulk phase. To explain the crystalline/non-crystalline crossovers, the contributions of the elastic strain density and twin boundary from the specimen surfaces to the cohesive energy of different motifs were evaluated. These results are expected to aid the design and synthesis of cobalt nanoparticles for applications ranging from catalysis to biomedical treatments.
Self-channel-and-spatial-attention neural network for automated multi-organ segmentation on head and neck CT images
Authors: Gou Shuiping , Tong Nuo , Qi Sharon , Yang Shuyuan , Chin Robert , Sheng Ke
Published: February 2020

Accurate segmentation of organs at risk (OARs) is necessary for adaptive head and neck (H&N) cancer treatment planning, but manual delineation is tedious, slow, and inconsistent. A self-channel-and-spatial-attention neural network (SCSA-Net) is developed for H&N OAR segmentation on CT images. To simultaneously ease the training and improve the segmentation performance, the proposed SCSA-Net utilizes the self-attention ability of the network. Spatial and channel-wise attention learning mechanisms are both employed to adaptively force the network to emphasize the meaningful features and weaken the irrelevant features simultaneously. The proposed network was first evaluated on a public dataset, which includes 48 patients, then on a separate serial CT dataset, which contains ten patients who received weekly diagnostic fan-beam CT scans. On the second dataset, the accuracy of using SCSA-Net to track the parotid and submandibular gland volume changes during radiotherapy treatment was quantified. The Dice similarity coefficient (DSC), positive predictive value (PPV), sensitivity (SEN), average surface distance (ASD), and 95% maximum surface distance (95SD) were calculated on the brainstem, optic chiasm, optic nerves, mandible, parotid glands, and submandibular glands to evaluate the proposed SCSA-Net. The proposed SCSA-Net consistently outperforms the state-of-the-art methods on the public dataset. Specifically, compared with Res-Net and SE-Net, which is constructed from squeeze-and-excitation block equipped residual blocks, the DSC of the optic nerves and submandibular glands is improved by 0.06, 0.03 and 0.05, 0.04 by the SCSA-Net. Moreover, the proposed method achieves statistically significant improvements in terms of DSC on all and eight of nine OARs over Res-Net and SE-Net, respectively. The trained network was able to achieve good segmentation results on the serial dataset, but the results were further improved after fine-tuning of the model using the simulation CT images. For the parotids and submandibular glands, the volume changes of individual patients are highly consistent between the automated and manual segmentation (Pearson’s correlation 0.97–0.99). The proposed SCSA-Net is computationally efficient to perform segmentation (sim 2 s/CT).
Transport of kJ-laser-driven relativistic electron beams in cold and shock-heated vitreous carbon and diamond
Authors: Bailly-Grandvaux M , Kim J , Krauland C M , Zhang S , Dozières M , Wei M S , Theobald W , Grabowski P E , Santos J J , Nicolaï Ph , McKenna P , Desjarlais M P , Beg F N
Published: February 2020

We report experimental results on relativistic electron beam (REB) transport in a set of cold and shock-heated carbon samples using the high-intensity kilojoule-class OMEGA EP laser. The REB energy distribution and transport were diagnosed using an electron spectrometer and x-ray fluorescence measurements from a Cu tracer buried at the rear side of the samples. The measured rear REB density shows brighter and narrower signals when the targets were shock-heated. Hybrid PIC simulations using advanced resistivity models in the target warm-dense-matter (WDM) conditions confirm this observation. We show that the resistivity response of the media, which governs the self-generated resistive fields, is of paramount importance to understand and correctly predict the REB transport.
Intercomparison of annual precipitation indices and extremes over global land areas from in situ, space-based and reanalysis products
Authors: Alexander Lisa V , Bador Margot , Roca Rémy , Contractor Steefan , Donat Markus G , Nguyen Phuong Loan
Published: February 2020

A range of in situ, satellite and reanalysis products on a common daily 1° × 1° latitude/longitude grid were extracted from the Frequent Rainfall Observations on Grids database to help facilitate intercomparison and analysis of precipitation extremes on a global scale. 22 products met the criteria for this analysis, namely that daily data were available over global land areas from 50°S to 50°N since at least 2001. From these daily gridded data, 10 annual indices that represent aspects of extreme precipitation frequency, duration and intensity were calculated. Results were analysed for individual products and also for four cluster types: (i) in situ, (ii) corrected satellite, (iii) uncorrected satellite and (iv) reanalyses. Climatologies based on a common 13-year period (2001–2013) showed substantial differences between some products. Timeseries (which ranged from 13 years to 67 years) also highlighted some substantial differences between products. A coefficient of variation showed that the in situ products were most similar to each other while reanalysis products had the largest variations. Reanalyses however agreed better with in situ observations over extra-tropical land areas compared to the satellite clusters, although reanalysis products tended to fall into ‘wet’ and ‘dry’ camps overall. Some indices were more robust than others across products with daily precipitation intensity showing the least variation between products and days above 20 mm showing the largest variation. In general, the results of this study show that global space-based precipitation products show the potential for climate scale analyses of extremes. While we recommend caution for all products dependent on their intended application, this particularly applies to reanalyses which show the most divergence across results.
Fostering natural forest regeneration on former agricultural land through economic and policy interventions
Authors: Chazdon Robin L , Lindenmayer David , Guariguata Manuel R , Crouzeilles Renato , Rey Benayas José María , Lazos Chavero Elena
Published: February 2020

Under suitable conditions, deforested land used for agricultural crops or pastures can revert to forest through the assisted or unassisted process of natural regeneration. These naturally regenerating forests conserve biodiversity, provide a wide array of ecosystem goods and services, and support rural economies and livelihoods. Based on studies in tropical and temperate forest ecosystems, we summarize cases where natural regeneration is occurring in agricultural landscapes around the world and identify the socio-ecological factors that favor its development and affect its qualities, outcomes and persistence. We describe how the economic and policy context creates barriers for the development, persistence, and management of naturally regenerating forests, including perverse outcomes of policies intended to enhance protection of native forests. We conclude with recommendations for specific economic and policy interventions at local, national, and global scales to enhance forest natural regeneration and to promote the sustainable management of regrowth forests on former agricultural land while strengthening rural communities and economies.
Rehabilitation and Reinforcement of Ferroconcrete Walls with Reinforced Pilasters
Authors: Novotný Michal , Všetečka Jan
Published: February 2020

The article is focused on renovation, rehabilitation and reinforcement of high ferroconcrete walls. It tries to point out the experience of experts in solving problems with high ferroconcrete walls. During a revitalization of buildings of a military accommodation facility in Brno with basement and connecting corridors of an average height of 25 m, degradation of concrete, locally missing reinforcement and poor-quality concrete mixtures, the strength class of which varied between C8/10–C10/12, were found in these corridors. Along the height of the pilasters, the structure also showed the signs of torsion and it was assessed the structure also needs to be strengthened/reinforced besides the rehabilitation. The reinforcement structure had to be built from the very foundation of the building, it is linked to the existing wall and has three cascade levels. For the first two parts, a construction pit has been created with a Berliner wall, and these parts reach below the modified terrain, are reinforced with concrete reinforcement according to the structural project, concreted with cast concrete, and the foundation is reinforced with deep-based construction. The second and the third parts of the cascade stretch from the modified terrain between the pilasters to the top and they are made with a two-stage shotcrete technique, the first one has inbuilt concrete reinforcement with welded wire mesh and the second one composite mesh anchored by helical reinforcement without static effect. In terms of the damage of the structure, carbon fibre wrapping technique or grouting of the existing ferroconcrete structure was also used in the affected areas. The article also includes photo documentation of the repairs and structural damage prior to them.
Use of Information Model in Creating the Investment-Construction Project
Authors: Cherkina V M , Shushunova N S
Published: February 2020

The use of information modeling technology in creating the investment-construction object provides a number of advantages to design, construction and operating organizations. Leading development companies should be transformed into a kind of IT-structure. In this regard, construction companies that develop their own strategies for switching to digital technologies and generate digital assets should, first of all, create the basis for their functioning - the integrated information model of the object - the BIM model. The latter includes all sections of the project and contains reliable and relevant information about the existing physical object. The concrete examples in this article show the results of the successful implementation of this approach in relation to capital construction projects of varying complexity.
Disorders of the Green Roof of the Pool Lucenice
Authors: Dědič Martin , Kaňkovský Aleš
Published: February 2020

The main objective of the article is to inform about the construction-technical survey, which focuses on the existing roofing of a pool area. The pool area is a separate object annexed to the historic farmhouse dating from the mid-19th century. Roofing of the pool area is made of a green roof. The main research issues stem from the building-technical survey focused on the green roof disorders. After detecting the faults, we look for their causes and find out which faults are fatal to the building and which can be easily removed. From the evaluated constructions, we focus primarily on the solution of the green roof in terms of correctly executed roof slope, plating, thermal technical properties of the materials, inherent weight of the structure and execution of individual layers of the composition of the green roof. Furthermore, we focus on determining the compliance of project documentation with the construction. We assess the impact of failures on the structure and operation of the building. In the conclusion we propose measures based on the found failures and possibilities for the solved structure.
Experimental Measurements of Wooden Solid Log Wall
Authors: Kacálek Petr , Petříček Tomáš
Published: February 2020

The contribution brings findings accrued from alternative design of log-wall’s lateral joint. The lateral joints present without question a thermal bridge highly repeating in the construction of external log wall. Field of the research was a theoretical design of wall models, simulation in software ANSYS and comparison theoretical results with results gained from the laboratory measurements of wall samples. Bed joints of wooden solid log walls are still a problematic detail in terms of thermal technology. By reason of weakening in the place of lateral joint and the value of coefficient of thermal conductivity, the solid wooden log wall does not meet requirements of Czech Standards ČSN 73 0540-2 posed to the value of wall’s thermal resistance. That is why we have focused on measurement of surface temperature, which is also one of the classified factors in term of construction quality. The project particularly focused on monitoring of surface temperatures in the areas of critical details – bed joints.
Investigating optical properties of Cr:GaN system for various Cr concentrations (A DFT + U study)
Authors: Khan M Junaid Iqbal , Liu Juan , Kanwal Zarfishan , Khan Muhammad Ismail , Usmani M Nauman , Khalid Ata Ur Rahman
Published: February 2020

We study electronic and optical properties of zincblende GaN doped with various Cr concentrations (3.12%, 6.25%, 9.37%). We conduct the calculations by employing DFT + U in Wien2K code while supercell size (1 × 2 × 2) is kept fixed for all cases. Electronic properties are changed with effect of dopant where 3d levels of dopant and 2p level of N produce p-d hybridization and this hybridization is highly affected by increasing impurity contents. Absorption spectra are blue shifted upon increase in dopant contents and absorption peaks are more pronounced in UV region. Refractive index and dielectric constant shows decrease as Cr concentration increases. Results reported in study indicate that Cr:GaN material may be considered a potential candidate for fabrication of optoelectronic, photonic and spintronic devices.
Atomic force microscopy phase imaging of epitaxial graphene films
Authors: Lavini Francesco , Cellini Filippo , Rejhon Martin , Kunc Jan , Berger Claire , de Heer Walt , Riedo Elisa
Published: February 2020

Dynamic mode atomic force microscopy phase imaging is known to produce distinct contrast between graphene areas of different atomic thickness. But the intrinsic complexity of the processes controlling the tip motion and the phase angle shift excludes its use as an independent technique for a quantitative type of analysis. By investigating the relationship between the phase shift, the tip-surface interaction, and the thickness of the epitaxial graphene areas grown on silicon carbide, we shed light on the origin of such phase contrast, and on the complex energy dissipation processes underlying phase imaging. In particular, we study the behavior of phase shift and energy dissipation when imaging the interfacial buffer layer, single-layer, and bilayer graphene regions as a function of the tip-surface separation and the interaction forces. Finally, we compare these results with those obtained on differently-grown quasi free standing single- and bilayer graphene samples.
Framelet pooling aided deep learning network: the method to process high dimensional medical data
Authors: Hyun Chang Min , Kim Kang Cheol , Cho Hyun Cheol , Choi Jae Kyu , Seo Jin Keun
Published: February 2020

Machine learning-based analysis of medical images often faces several hurdles, such as the lack of training data, the curse of the dimensionality problem, and generalization issues. One of the main difficulties is that there exists a computational cost problem in dealing with input data of large size matrices which represent medical images. The purpose of this paper is to introduce a framelet-pooling aided deep learning method for mitigating computational bundles caused by large dimensionality. By transforming high dimensional data into low dimensional components by filter banks and preserving detailed information, the proposed method aims to reduce the complexity of the neural network and computational costs significantly during the learning process. Various experiments show that our method is comparable to the standard unreduced learning method, while reducing computational burdens by decomposing large-sized learning tasks into several small-scale learning tasks.
Fiction and Emotion: The Puzzle of Divergent Norms
Authors: Friend Stacie
Published: February 2020

A familiar question in the literature on emotional responses to fiction, originally put forward by Colin Radford, is how such responses can be rational. How can we make sense of pitying Anna Karenina when we know there is no such person? In this paper I argue that contrary to the usual interpretation, the question of rationality has nothing to do with the Paradox of Fiction. Instead, the real problem is why there is a divergence in our normative assessments of emotions in different contexts. I argue that explaining this divergence requires a more nuanced account of the rationality of emotion than has previously been proposed. One advantage of my proposal over alternatives is that it helps to explain one way we can learn emotionally from fiction and imagination.
Evaluation of an Occupational Safety and Health Training for Cannabis Cultivation Workers
Authors: Brown Carol E , Shore Erin , Van Dyke Mike V , Scott Joshua , Smith Roberta
Published: February 2020

Objectives

As the commercial cannabis industry grows, there is an increased need to characterize potentially hazardous workplace exposures and provide training to workers to mitigate these exposures with the goal of reducing accidents and injuries from cannabis cultivation, processing, and manufacturing. Public health and safety stakeholders in Colorado developed a worker-focused training designed to improve hazard awareness, recognition, and controls related to commercial cannabis cultivation. This paper describes the evaluation of this training.

Methods

The training was a full day, in-person educational experience directed to workers in the cannabis cultivation industry. Training topics included an overview of occupational safety and health hazards, chemical exposures, slip, trips, and falls, repetitive motion, the application of the hierarchy of control including lockout/tagout, machine guarding, personal protective equipment, among others. Evaluation surveys assessed attendee demographics, perceived job hazards, confidence to change workplace practices, knowledge, training relevancy and quality, intent to change behavior, as well as barriers and resources.

Results

A total of 208 people attended the safety trainings. One hundred and thirty-four participants (64%) completed the pre-training survey and 107 (51%) completed the post-training survey. Respondents provided high ratings for the quality and relevance of the training, with 91.3% of respondents rating the training very good or excellent. Before the training, the attendees listed their most concerning safety and health issues as exposure to pesticides and other chemicals (65.7%), absorbing chemicals through the skin (56.7%), slips, trips, and falls (52.2%), and respiratory hazards (50.7%). After the training, they reported the most concerning hazards to be slips, trips, and fall hazards (65.4%), ergonomic problems (64.5%), and respiratory issues (61.7%). There was a statistically non-significant increase in knowledge scores from 67.1% correct to 76.0% correct. Finally, 88.5% of respondents felt extremely or very confident that they could change their own health and safety practices at work.

Conclusions

The training successfully reached cannabis employees in cultivation, compliance, and management. Survey respondents felt that the training was of high quality and addressed gaps in their knowledge related to safety and health hazards in the cannabis industry. The workplace safety and health concerns shifted from pre- to post-training. There was a statistically non-significant increase in knowledge. Additional follow-up of training attendees would be beneficial to measure sustained impact of training.
Characterization and Quantification of Ultrafine Particles and Carbonaceous Components from Occupational Exposures to Diesel Particulate Matter in Selected Workplaces
Authors: da Silveira Fleck Alan , Catto Cyril , L’Espérance Gilles , Masse Jean-Philippe , Roberge Brigitte , Debia Maximilien
Published: February 2020

Questions still exist regarding which indicator better estimates worker’s exposure to diesel particulate matter (DPM) and, especially for ultrafine particles (UFP), how exposure levels and the characteristics of the particles vary in workplaces with different exposure conditions. This study aimed to quantify and characterize DPM exposures in three workplaces with different exposure levels: an underground mine, a subway tunnel, and a truck repair workshop. The same sampling strategy was used and included measurements of the particle number concentration (PNC), mass concentration, size distribution, transmission electron microscopy (TEM), and the characterization of carbonaceous fractions. The highest geometric means (GMs) of PNC and elemental carbon (EC) were measured in the mine [134 000 (geometric standard deviation, GSD = 1.5) particles cm−3 and 125 (GSD = 2.1) µg m−3], followed by the tunnel [32 800 (GSD = 1.7) particles cm−3 and 24.7 (GSD = 2.4) µg m−3], and the truck workshop [22 700 (GSD = 1.3) particles cm−3 and 2.7 (GSD = 2.4) µg m−3]. This gradient of exposure was also observed for total carbon (TC) and particulate matter. The TC/EC ratio was 1.4 in the mine, 2.5 in the tunnel and 8.7 in the workshop, indicating important organic carbon interference in the non-mining workplaces. EC and PNC were strongly correlated in the tunnel (r = 0.85; P < 0.01) and the workshop (r = 0.91; P < 0.001), but a moderate correlation was observed in the mine (r = 0.57; P < 0.05). Results from TEM showed individual carbon spheres between 10 and 56.5 nm organized in agglomerates, while results from the size distribution profiles showed bimodal distributions with a larger accumulation mode in the mine (93 nm) compared with the tunnel (39 nm) and the truck workshop (34 nm). In conclusion, the composition of the carbonaceous fraction varies according to the workplace, and can interfere with DPM estimation when TC is used as indicator. Also, the dominance of particles <100 nm in all workplaces, the high levels of PNC measured and the good correlation with EC suggest that UFP exposures should receive more attention on occupational routine measurements and regulations.
Exposure to Solar UV During Outdoor Construction Work in Britain
Authors: Cherrie John W , Nioi Amanda , Wendelboe-Nelson Charlotte , Cowan Sue , Cherrie Mark , Rashid Shahzad , Cowie Hilary , Ritchie Peter , Lansdown Terry C
Published: February 2020

Excessive exposure to ultraviolet (UV) radiation from the sun in summer can cause skin cancer and in Britain there are around 1500 new cases of non-melanoma skin cancer (NMSC) each year, caused by exposure to solar UV at work. Little is known about the magnitude of UV exposure amongst outdoor construction workers in Britain, although this is one of the main groups at risk. The aim of this paper is to summarise measurements of erythema-weighted UVB radiation amongst construction workers in Scotland and the Southeast of England and interpret the data in terms of the risk of NMSC. The measurements were made as part of an intervention study using short mobile phone text messages to alter worker behaviour to either reduce UV exposure in summer or increase serum vitamin D in winter; the intervention is only briefly reported here. Data were collected from 67 workers from 9 worksites, of whom 41 provided measures of UV exposure for 758 working days. Daily exposure ranged from 0 to 13.47 standard erythema dose (SED), with the mean exposure for outdoor workers being 2.0 SED and the corresponding value for indoor workers being 0.7 SED. These data were obtained from a sensor located on the back of the workers hard hat; others have measured exposure on the wrist or upper arm and these locations probably, on average, have higher levels of UV exposure. It is likely that an outdoor construction worker in Britain could accumulate sufficient solar UV exposure over 30–40 years of work to more than double their risk of NMSC. We argue that employers in Britain should take a more proactive approach to manage sun safety and they should take responsibility for skin health surveillance for their workers.
Ensemble estimation and variable selection with semiparametric regression models
Authors: Shin Sunyoung , Liu Yufeng , Cole Stephen R , Fine Jason P
Published: February 2020

We consider scenarios in which the likelihood function for a semiparametric regression model factors into separate components, with an efficient estimator of the regression parameter available for each component. An optimal weighted combination of the component estimators, named an ensemble estimator, may be employed as an overall estimate of the regression parameter, and may be fully efficient under uncorrelatedness conditions. This approach is useful when the full likelihood function may be difficult to maximize, but the components are easy to maximize. It covers settings where the nuisance parameter may be estimated at different rates in the component likelihoods. As a motivating example we consider proportional hazards regression with prospective doubly censored data, in which the likelihood factors into a current status data likelihood and a left-truncated right-censored data likelihood. Variable selection is important in such regression modelling, but the applicability of existing techniques is unclear in the ensemble approach. We propose ensemble variable selection using the least squares approximation technique on the unpenalized ensemble estimator, followed by ensemble re-estimation under the selected model. The resulting estimator has the oracle property such that the set of nonzero parameters is successfully recovered and the semiparametric efficiency bound is achieved for this parameter set. Simulations show that the proposed method performs well relative to alternative approaches. Analysis of an AIDS cohort study illustrates the practical utility of the method.
Political Climate, Voter Suppression Policies and Federal Sentencing Outcomes
Authors: Nowacki Jeffrey S , Creech Danielle , Parks Megan
Published: February 2020

Many states in the United States have recently implemented voter suppression policies, which make voting more difficult, particularly for members of marginalized populations (e.g. non-white and female voters). In this article, we examine how these policies and other measures of political climate influence criminal sentencing in US district courts. Using 2015 data from the US Sentencing Commission, alongside other district-level measures, we find both direct and conditioning relationships between political climate and extra-legal variables. Specifically, we find that, while voter suppression policies do not directly affect sentence length, racial threat effects are enhanced in districts governed by such policies. Conversely, districts without such policies see larger mitigating effects at high levels of ethnic diversity and gender equality.
Ultrasound Stimulation Suppresses LPS-Induced Proinflammatory Responses by Regulating NF-κB and CREB Activation in Microglial Cells
Authors: Chang Jia-Wei , Wu Meng-Ting , Song Wen-Shin , Yang Feng-Yi
Published: February 2020

The purpose of this study was to investigate the effects and underlying mechanisms of low-intensity pulsed ultrasound (LIPUS) against lipopolysaccharide (LPS)-induced neuroinflammation. BV-2 microglia subjected to LPS administration (1 μg/mL) were treated with LIPUS stimulation. The levels of inflammatory mediators and brain-derived neurotrophic factor (BDNF) were quantified using the western blot. The results showed that LIPUS stimulation promoted the associated cAMP response element-binding protein (CREB)/BDNF expression in the LPS-treated microglia. Meanwhile, LIPUS treatment effectively suppressed the LPS-induced production of tumor necrosis factor-α, interleukin-1β, interleukin-6, inducible nitric oxide synthase, and cyclooxygenase-2 in the microglial cells, in addition to inhibiting the LPS-induced expressions of toll-like receptor 4 and myeloid differentiation factor 88, as well as the LPS-induced activation of c-Jun N-terminal kinase and nuclear factor kappa B. Furthermore, LIPUS significantly decreased the Bax/Bcl-2 ratio in the microglia following LPS treatment. Our data indicated that LIPUS attenuated the proinflammatory responses as well as the decline in BDNF in LPS-treated microglia. This study provides a better understanding of how LIPUS stimulation regulates anti-inflammatory actions in microglia, providing further evidence suggesting that such stimulation may be regarded as a novel strategy for the treatment of neuroinflammation.