bluuebunny/crossref_metadata_2025 huggingface dataset:
The arginine repressor of Escherichia coli
Authors: Maas W K
Published: December 2020

This review tells the story of the arginine repressor of Escherichia coli from the time of its discovery in the 1950s until the present. It describes how the research progressed through physiological, genetic, and biochemical phases and how the nature of the repressor and its interaction with its target sites were unraveled. The studies of the repression of arginine biosynthesis revealed unique features at every level of the investigations. In the early phase of the work they showed that the genes controlled by the arginine repressor were scattered over the linkage map and were not united, as in other cases, in a single operon. This led to the concept of the regulon as a physiological unit of regulation. It was also shown that different alleles of the arginine repressor could result in either inhibition of enzyme formation, as in E. coli K-12, or in stimulation of enzyme formation, as in E. coli B. Later it was shown that the arginine repressor is a hexamer, whereas other repressors of biosynthetic pathways are dimers. As a consequence the arginine repressor binds to two palindromic sites rather than to one. It was found that the arginine repressor not only acts in the repression of enzyme synthesis but also is required for the resolution of plasmid multimers to monomers, a completely unrelated function. Finally, the arginine repressor does not possess characteristic structural features seen in other prokaryotic repressors, such as a helix-turn-helix motif or an antiparallel beta-sheet motif. The unique features have sustained continuous interest in the arginine repressor and have made it a challenging subject of investigation.
Bacterial dehalogenases: biochemistry, genetics, and biotechnological applications
Authors: Fetzner S , Lingens F
Published: December 2020

This review is a survey of bacterial dehalogenases that catalyze the cleavage of halogen substituents from haloaromatics, haloalkanes, haloalcohols, and haloalkanoic acids. Concerning the enzymatic cleavage of the carbon-halogen bond, seven mechanisms of dehalogenation are known, namely, reductive, oxygenolytic, hydrolytic, and thiolytic dehalogenation; intramolecular nucleophilic displacement; dehydrohalogenation; and hydration. Spontaneous dehalogenation reactions may occur as a result of chemical decomposition of unstable primary products of an unassociated enzyme reaction, and fortuitous dehalogenation can result from the action of broad-specificity enzymes converting halogenated analogs of their natural substrate. Reductive dehalogenation either is catalyzed by a specific dehalogenase or may be mediated by free or enzyme-bound transition metal cofactors (porphyrins, corrins). Desulfomonile tiedjei DCB-1 couples energy conservation to a reductive dechlorination reaction. The biochemistry and genetics of oxygenolytic and hydrolytic haloaromatic dehalogenases are discussed. Concerning the haloalkanes, oxygenases, glutathione S-transferases, halidohydrolases, and dehydrohalogenases are involved in the dehalogenation of different haloalkane compounds. The epoxide-forming halohydrin hydrogen halide lyases form a distinct class of dehalogenases. The dehalogenation of alpha-halosubstituted alkanoic acids is catalyzed by halidohydrolases, which, according to their substrate and inhibitor specificity and mode of product formation, are placed into distinct mechanistic groups. beta-Halosubstituted alkanoic acids are dehalogenated by halidohydrolases acting on the coenzyme A ester of the beta-haloalkanoic acid. Microbial systems offer a versatile potential for biotechnological applications. Because of their enantiomer selectivity, some dehalogenases are used as industrial biocatalysts for the synthesis of chiral compounds. The application of dehalogenases or bacterial strains in environmental protection technologies is discussed in detail.
Control of gene expression in trypanosomes
Authors: Vanhamme L , Pays E
Published: December 2020

Trypanosomes are protozoan agents of major parasitic diseases such as Chagas' disease in South America and sleeping sickness of humans and nagana disease of cattle in Africa. They are transmitted to mammalian hosts by specific insect vectors. Their life cycle consists of a succession of differentiation and growth phases requiring regulated gene expression to adapt to the changing extracellular environment. Typical of such stage-specific expression is that of the major surface antigens of Trypanosoma brucei, procyclin in the procyclic (insect) form and the variant surface glycoprotein (VSG) in the bloodstream (mammalian) form. In trypanosomes, the regulation of gene expression is effected mainly at posttranscriptional levels, since primary transcription of most of the genes occurs in long polycistronic units and is constitutive. The transcripts are processed by transsplicing and polyadenylation under the influence of intergenic polypyrimidine tracts. These events show some developmental regulation. Untranslated sequences of the mRNAs seem to play a prominent role in the stage-specific control of individual gene expression, through a modulation of mRNA abundance. The VSG and procyclin transcription units exhibit particular features that are probably related to the need for a high level of expression. The promoters and RNA polymerase driving the expression of these units resemble those of the ribosomal genes. Their mutually exclusive expression is ensured by controls operating at several levels, including RNA elongation. Antigenic variation in the bloodstream is achieved through DNA rearrangements or alternative activation of the telomeric VSG gene expression sites. Recent discoveries, such as the existence of a novel nucleotide in telomeric DNA and the generation of point mutations in VSG genes, have shed new light on the mechanisms and consequences of antigenic variation.
The plasma membrane of Saccharomyces cerevisiae: structure, function, and biogenesis
Authors: van der Rest M E , Kamminga A H , Nakano A , Anraku Y , Poolman B , Konings W N
Published: December 2020

The composition of phospholipids, sphingolipids, and sterols in the plasma membrane has a strong influence on the activity of the proteins associated or embedded in the lipid bilayer. Since most lipid-synthesizing enzymes in Saccharomyces cerevisiae are located in intracellular organelles, an extensive flux of lipids from these organelles to the plasma membrane is required. Although the pathway of protein traffic to the plasma membrane is similar to that of most of the lipids, the bulk flow of lipids is separate from vesicle-mediated protein transport. Recent advances in the analysis of membrane budding and membrane fusion indicate that the mechanisms of protein transport from the endoplasmic reticulum to the Golgi and from the Golgi to plasma membrane are similar. The majority of plasma membrane proteins transport solutes across the membrane. A number of ATP-dependent export systems have been detected that couple the hydrolysis of ATP to transport of molecules out of the cell. The hydrolysis of ATP by the plasma membrane H(+)-ATPase generates a proton motive force which is used to drive secondary transport processes. In S. cerevisiae, many substrates are transported by more than one system. Transport of monosaccharide is catalyzed by uniport systems, while transport of disaccharides, amino acids, and nucleosides is mediated by proton symport systems. Transport activity can be regulated at the level of transcription, e.g., induction and (catabolite) repression, but transport proteins can also be affected posttranslationally by a process termed catabolite inactivation. Catabolite inactivation is triggered by the addition of fermentable sugars, intracellular acidification, stress conditions, and/or nitrogen starvation. Phosphorylation and/or ubiquitination of the transport proteins has been proposed as an initial step in the controlled inactivation and degradation of the target enzyme. The use of artificial membranes, like secretory vesicles and plasma membranes fused with proteoliposomes, as model systems for studies on the mechanism and regulation of transport is evaluated.
Chromosome-length polymorphism in fungi
Authors: Zolan M E
Published: December 2020

The examination of fungal chromosomes by pulsed-field gel electrophoresis has revealed that length polymorphism is widespread in both sexual and asexual species. This review summarizes characteristics of fungal chromosome-length polymorphism and possible mitotic and meiotic mechanisms of chromosome length change. Most fungal chromosome-length polymorphisms are currently uncharacterized with respect to content and origin. However, it is clear that long tandem repeats, such as tracts of rRNA genes, are frequently variable in length and that other chromosomal rearrangements are suppressed during normal mitotic growth. Dispensable chromosomes and dispensable chromosome regions, which have been well documented for some fungi, also contribute to the variability of the fungal karyotype. For sexual species, meiotic recombination increases the overall karyotypic variability in a population while suppressing genetic translocations. The range of karyotypes observed in fungi indicates that many karyotypic changes may be genetically neutral, at least under some conditions. In addition, new linkage combinations of genes may also be advantageous in allowing adaptation of fungi to new environments.
Methanotrophic bacteria
Authors: Hanson R S , Hanson T E
Published: December 2020

Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehyde assimilation, whereas type II methanotrophs, which employ the serine pathway for formaldehyde assimilation, form a coherent cluster within the beta subdivision of the Proteobacteria. Methanotrophic bacteria are ubiquitous. The growth of type II bacteria appears to be favored in environments that contain relatively high levels of methane, low levels of dissolved oxygen, and limiting concentrations of combined nitrogen and/or copper. Type I methanotrophs appear to be dominant in environments in which methane is limiting and combined nitrogen and copper levels are relatively high. These bacteria serve as biofilters for the oxidation of methane produced in anaerobic environments, and when oxygen is present in soils, atmospheric methane is oxidized. Their activities in nature are greatly influenced by agricultural practices and other human activities. Recent evidence indicates that naturally occurring, uncultured methanotrophs represent new genera. Methanotrophs that are capable of oxidizing methane at atmospheric levels exhibit methane oxidation kinetics different from those of methanotrophs available in pure cultures. A limited number of methanotrophs have the genetic capacity to synthesize a soluble methane monooxygenase which catalyzes the rapid oxidation of environmental pollutants including trichloroethylene.
Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO)
Authors: Conrad R
Published: December 2020

Production and consumption processes in soils contribute to the global cycles of many trace gases (CH4, CO, OCS, H2, N2O, and NO) that are relevant for atmospheric chemistry and climate. Soil microbial processes contribute substantially to the budgets of atmospheric trace gases. The flux of trace gases between soil and atmosphere is usually the result of simultaneously operating production and consumption processes in soil: The relevant processes are not yet proven with absolute certainty, but the following are likely for trace gas consumption: H2 oxidation by abiontic soil enzymes; CO cooxidation by the ammonium monooxygenase of nitrifying bacteria; CH4 oxidation by unknown methanotrophic bacteria that utilize CH4 for growth; OCS hydrolysis by bacteria containing carbonic anhydrase; N2O reduction to N2 by denitrifying bacteria; NO consumption by either reduction to N2O in denitrifiers or oxidation to nitrate in heterotrophic bacteria. Wetland soils, in contrast to upland soils are generally anoxic and thus support the production of trace gases (H2, CO, CH4, N2O, and NO) by anaerobic bacteria such as fermenters, methanogens, acetogens, sulfate reducers, and denitrifiers. Methane is the dominant gaseous product of anaerobic degradation of organic matter and is released into the atmosphere, whereas the other trace gases are only intermediates, which are mostly cycled within the anoxic habitat. A significant percentage of the produced methane is oxidized by methanotrophic bacteria at anoxic-oxic interfaces such as the soil surface and the root surface of aquatic plants that serve as conduits for O2 transport into and CH4 transport out of the wetland soils. The dominant production processes in upland soils are different from those in wetland soils and include H2 production by biological N2 fixation, CO production by chemical decomposition of soil organic matter, and NO and N2O production by nitrification and denitrification. The processes responsible for CH4 production in upland soils are completely unclear, as are the OCS production processes in general. A problem for future research is the attribution of trace gas metabolic processes not only to functional groups of microorganisms but also to particular taxa. Thus, it is completely unclear how important microbial diversity is for the control of trace gas flux at the ecosystem level. However, different microbial communities may be part of the reason for differences in trace gas metabolism, e.g., effects of nitrogen fertilizers on CH4 uptake by soil; decrease of CH4 production with decreasing temperature; or different rates and modes of NO and N2O production in different soils and under different conditions.
Flow cytometry and cell sorting of heterogeneous microbial populations: the importance of single-cell analyses
Authors: Davey H M , Kell D B
Published: December 2020

The most fundamental questions such as whether a cell is alive, in the sense of being able to divide or to form a colony, may sometimes be very hard to answer, since even axenic microbial cultures are extremely heterogeneous. Analyses that seek to correlate such things as viability, which is a property of an individual cell, with macroscopic measurements of culture variables such as ATP content, respiratory activity, and so on, must inevitably fail. It is therefore necessary to make physiological measurements on individual cells. Flow cytometry is such a technique, which allows one to analyze cells rapidly and individually and permits the quantitative analysis of microbial heterogeneity. It therefore offers many advantages over conventional measurements for both routine and more exploratory analyses of microbial properties. While the technique has been widely applied to the study of mammalian cells, is use in microbiology has until recently been much more limited, largely because of the smaller size of microbes and the consequently smaller optical signals obtainable from them. Since these technical barriers no longer hold, flow cytometry with appropriate stains has been used for the rapid discrimination and identification of microbial cells, for the rapid assessment of viability and of the heterogeneous distributions of a wealth of other more detailed physiological properties, for the analysis of antimicrobial drug-cell interactions, and for the isolation of high-yielding strains of biotechnological interest. Flow cytometric analyses provide an abundance of multivariate data, and special methods have been devised to exploit these. Ongoing advances mean that modern flow cytometers may now be used by nonspecialists to effect a renaissance in our understanding of microbial heterogeneity.
Determining the source of placer gold in the Anaconda metamorphic core complex supradetachment basin using detrital zircon U-Pb geochronology, western Montana, USA
Authors: Howlett Caden J. , Laskowski Andrew K.
Published: December 2020

Despite the widespread occurrence and economic significance of gold placer deposits, modern provenance studies of placer sediments remain largely qualitative. This study applies detrital zircon (DZ) geochronology to determine the source of zircon in placer deposits. We then evaluate the provenance of the zircon to assess whether the gold might have been derived from the same sources, thereby providing a case study of the use of DZ geochronology applied to placers. We present a new set of DZ U-Pb ages (n = 1058) and Lu-Hf (n = 61) isotopic data from four placer deposit samples collected from the Pioneer District of western Montana (USA). Each of the four samples yielded similar age spectra, with a range of U-Pb ages between 3000 and 25 Ma. We interpret that ≥250 Ma zircons were recycled from the Mesoproterozoic Belt Supergroup, Paleozoic–Mesozoic sedimentary rocks, and the Upper Cretaceous–Paleocene Beaverhead Group. Our 237 DZ U-Pb ages ≤250 Ma reveal two prominent age-probability peaks centered at ca. 69 Ma and ca. 26 Ma, which we interpret to record first-cycle derivation from the Royal stock and nearby Dillon Volcanics, respectively. We evaluate these data using an inverse Monte Carlo DZ unmixing model that calculates relative contributions from plausible source units, determining a 12% contribution from the Royal stock and a 43% contribution from the Beaverhead Group. A current absence of the Beaverhead Group in the hypothesized source region suggests complete erosion of the unit into the placer-bearing basin.

Detrital zircon geochronology, Hf isotopic data, and the unmixing modeling results offer the first zircon-based support for previous interpretations that the Late Cretaceous Royal stock precipitated gold along its contact with overlying Proterozoic–Mesozoic sedimentary strata. Subsequent exhumation and erosion of the lode source led to gold deposition in the Anaconda metamorphic core complex supradetachment basin during the late Oligocene–late Miocene. The worldwide occurrence of gold placer deposits with unknown source areas provides abundant opportunity to apply these techniques elsewhere.
Evaluating cross contamination on a shared ventilator
Authors: Doukas Donald Joseph , Paladino Lorenzo , Hanuscin Christopher , McMahon Jonathan , Quale John , Bhatt Isha , Eason Julie , Silverberg Mark
Published: December 2020

Background

Disasters have the potential to cause critical shortages of life-saving equipment. It has been postulated that during patient surge, multiple individuals could be maintained on a single ventilator. This was supported by a previous trial that showed one ventilator could support four sheep. The goal of our study is to investigate if cross contamination of pathological agents occurs between individuals on a shared ventilator with strategically placed antimicrobial filters.

Methods

A multipatient ventilator circuit was assembled using four sterile, parallel standard tubing circuits attached to four 2 L anaesthesia bags, each representing a simulated patient. Each ‘patient’ was attached to a Heat and Moisture Exchange filter. An additional bacterial/viral filter was attached to each expiratory limb. ‘Patient-Lung’ number 1 was inoculated with an isolate ofSerratia marcescens,and the circuit was run for 24 hours. Each ‘lung’ and three points in the expiratory limb tubing were washed with broth and cultured. All cultures were incubated for 48 hours with subcultures performed at 24 hours.

Results

Washed cultures of patient 2, 3 and 4 failed to demonstrate growth ofS. marcescens. Cultures of the distal expiratory tubing, expiratory limb connector and expiratory limb prefilter tubing yielded no growth ofS. marcescensat 24 or 48 hours.

Conclusion

Based on this circuit configuration, it is plausible to maintain four individuals on a single ventilator for 24 hours without fear of cross contamination.
Liquid biopsy forBRAFmutations testing in non-small cell lung cancer: a retrospective study
Authors: Iaccarino Antonino , Pisapia Pasquale , Pepe Francesco , Sgariglia Roberta , Nacchio Mariantonia , Russo Gianluca , Gragnano Gianluca , De Luca Caterina , Troncone Giancarlo , Malapelle Umberto
Published: December 2020

V-Raf murine sarcoma viral oncogene homolog B (BRAF) gene mutations have recently been approved to select advanced stages non-small cell lung cancer (NSCLC) patients for tyrosine kinase inhibitors treatments. In this setting, liquid biopsy may represent a valuable option forBRAFmutational testing in patients without tissue availability. Here, we reviewed 196 plasma based liquid biopsies analysed by an in-house developed next generation sequencing panel, termed SiRe. On the overall, 6 (3.1%) out of 196BRAFmutated cases were identified, with an overall median allelic frequency of 3.4%. Exon 15 p.V600E was the most common detected mutation (2/6, 33.3%). Our data highlighted that the SiRe panel is a robust tool forBRAFmutation assessment on circulating tumour DNA. Further investigation is required to develop a diagnostic algorithm to harmoniseBRAFtesting on tissue and blood in advanced stages NSCLC patients.
Reading heredity in racist environments: epigenetic imaginaries in Bessie Head’sThe Cardinals
Authors: Hemsley Frances
Published: December 2020

The field of epigenetics research shows us how we are constructed by what is without—materially, socially and environmentally—while also taking us beyond narrow genetic determinants of heredity. If misappropriated, epigenetics research risks pathologising particular social or ethnic groups as biologically damaged. However, epigenetics may also allow us to better conceptualise the biopsychosocially constitutive nature of racist environments. In this article, I argue that epigenetic understandings of embodiment allow us to follow Achille Mbembe’s recommendation: that to account for postcolonial relations of power—their effectiveness and psychology—we need to go beyond the binary categories (like passivity vs resistance) so frequently deployed in the analysis of domination. To demonstrate this, I offer a literary example from apartheid South Africa. In Bessie Head’sThe Cardinals, embodiment is imagined as the hereditary effect of segregated environmental space.The Cardinalsthus offers something like a literary imagining of the epigenetic (as a material change that is heritable), before contemporary advances in epigenetics research made the connection between environment and embodiment more sensible in molecular terms. Head radically calls into question the certainty of biological identity: characters are ‘marked’ deterministically by their environments but ultimately the mutability of such ‘epigenetic’ markers is revealed when the individual transcends apartheid’s spatial and racial demarcations. Writing in the context of apartheid, Head’s engagement with non-genetic understandings of identity is a motivated attempt to evade the stigmatising categories and ‘genetic’ assumptions of scientific racism, which constructed races as biologically distinct (modern genetic science shows us that there is no genetic basis for ‘race’). Instead, Head positions environmental spaces, including the Indian Ocean (a conduit for South Asian arrivals and for new philosophies and the potential political affiliations that arrive with them) as points of genealogical origin and as constitutive of identity in non-deterministic ways.
Do declines in occupational physical activity contribute to population gains in body mass index? Tromsø Study 1974–2016
Authors: Sagelv Edvard H , Ekelund Ulf , Hopstock Laila A , Aars Nils Abel , Fimland Marius Steiro , Jacobsen Bjarne Koster , Løvsletten Ola , Wilsgaard Tom , Morseth Bente
Published: December 2020

Objective

To examine whether occupational physical activity changes predict future body mass index (BMI) changes.

Methods

This longitudinal cohort study included adult participants attending ≥3 consecutive Tromsø Study surveys (examinations 1, 2 and 3) from 1974 to 2016 (N=11 308). If a participant attended >3 surveys, the three most recent surveys were included. Occupational physical activity change (assessed by the Saltin-Grimby Physical Activity Level Scale) was computed from the first to the second examination, categorised into persistently inactive (n=3692), persistently active (n=5560), active to inactive (n=741) and inactive to active (n=1315). BMI change was calculated from the second to the third examination (height being fixed at the second examination) and regressed on preceding occupational physical activity changes using analysis of covariance adjusted for sex, birth year, smoking, education and BMI at examination 2.

Results

Overall, BMI increased by 0.84 kg/m2(95% CI 0.82 to 0.89). Following adjustments as described previously, we observed no differences in BMI increase between the occupational physical activity change groups (Persistently Inactive: 0.81 kg/m2, 95% CI 0.75 to 0.87; Persistently Active: 0.87 kg/m2, 95% CI 0.82 to 0.92; Active to Inactive: 0.81 kg/m2, 95% CI 0.67 to 0.94; Inactive to Active: 0.91 kg/m2, 95% CI 0.81 to 1.01; p=0.25).

Conclusion

We observed no prospective association between occupational physical activity changes and subsequent BMI changes. Our findings do not support the hypothesis that occupational physical activity declines contributed to population BMI gains over the past decades. Public health initiatives aimed at weight gain prevention may have greater success if focusing on other aspects than occupational physical activity.
The generally covariant meaning of space distances
Authors: Capozziello S. , Chiappini A. , Fatibene L. , Orizzonte A.
Published: December 2020

We propose a covariant and geometric framework to introduce space distances as they are used by astronomers. In particular, we extend the definition of space distances from the one used between events to non-test bodies with horizons and singularities so that the definition extends through the horizons and it matches the protocol used to measure them. The definition we propose can be used in standard general relativity although it extends directly to Weyl geometries to encompass a number of modified theories, extended theories in particular.
Impact of Machine Learning Pipeline Choices in Autism Prediction From Functional Connectivity Data
Authors: Graña Manuel , Silva Moises
Published: December 2020

Autism Spectrum Disorder (ASD) is a largely prevalent neurodevelopmental condition with a big social and economical impact affecting the entire life of families. There is an intense search for biomarkers that can be assessed as early as possible in order to initiate treatment and preparation of the family to deal with the challenges imposed by the condition. Brain imaging biomarkers have special interest. Specifically, functional connectivity data extracted from resting state functional magnetic resonance imaging (rs-fMRI) should allow to detect brain connectivity alterations. Machine learning pipelines encompass the estimation of the functional connectivity matrix from brain parcellations, feature extraction, and building classification models for ASD prediction. The works reported in the literature are very heterogeneous from the computational and methodological point of view. In this paper, we carry out a comprehensive computational exploration of the impact of the choices involved while building these machine learning pipelines. Specifically, we consider six brain parcellation definitions, five methods for functional connectivity matrix construction, six feature extraction/selection approaches, and nine classifier building algorithms. We report the prediction performance sensitivity to each of these choices, as well as the best results that are comparable with the state of the art.
Spatial interference between infectious hotspots: Epidemic condensation and optimal windspeed
Authors: Dieplinger Johannes , Succi Sauro
Published: December 2020

We discuss the effects of spatial interference between two infectious hotspots as a function of the mobility of individuals (wind speed) between the two and their relative degree of infectivity. As long as the upstream hotspot is less contagious than the downstream one, increasing the wind speed leads to a monotonic decrease of the infection peak in the downstream hotspot. Once the upstream hotspot becomes about between twice and five times more infectious than the downstream one, an optimal wind speed emerges, whereby a local minimum peak intensity is attained in the downstream hotspot, along with a local maximum beyond which the beneficial effect of the wind is restored. Since this nonmonotonic trend is reminiscent of the equation of state of nonideal fluids, we dub the above phenomena “epidemic condensation”. When the relative infectivity of the upstream hotspot exceeds about a factor five, the beneficial effect of the wind above the optimal speed is completely lost: any wind speed above the optimal one leads to a higher infection peak. It is also found that spatial correlation between the two hotspots decay much more slowly than their inverse distance. It is hoped that the above findings may offer a qualitative clue for optimal confinement policies between different cities and urban agglomerates.
Surveillance Video Coding for Traffic Scene based on Vehicle Knowledge and Shared Library by Cloud-Edge Computing in Cyber-Physical-Social Systems
Authors: Wang Gang , Zhou Mingliang , Fang Bin , Wen Shiting
Published: December 2020

With rapid development of intelligent video surveillance systems based on cloud computing devices and edge computing devices in Cyber-Physical-Social Systems, massive surveillance video data has brings enormous challenge for video storage and transmission. However, existing surveillance video coding approaches hardly utilize intelligent video analysis results for improving video coding. This paper proposed a surveillance video coding scheme for traffic scene based on vehicle knowledge and shared library by cloud-edge computing in Cyber-Physical-Social Systems. Firstly, in order to provide the object library for synchronous application at the encode and decode side offline, a generation method of shared long-term foreground reference object library is proposed by using the existing large-scale monitoring vehicle object datasets. Then, to meet the requirement of low complexity and high-performance coding, a virtual foreground reference picture generation method with coding-oriented object retrieval is proposed. Experimental results show that the proposed scheme can obtain the satisfactory effect of the virtual foreground reference picture. Also, it can yield remarkable bit rate reductions, compared to HEVC.
EPS: Robust Pupil Edge Points Selection with Haar Feature and Morphological Pixel Patterns
Authors: Shi Lu , Wang Changyuan , Jia Hongbo , Hu Xiuhua
Published: December 2020

Pupil parameters are the essential foundation for many applications, such as cognitive science and human–machine interaction. Existing approaches are still affected by various challenges. We propose a novel pupil detection pipeline (known as Edge Points Selector “EPS”) which is suitable even for partial occlusion, lighting, and specular reflection. EPS consists of pupil area detection, edge selection, and ellipse fitting. For the first time, we find the suitable Haar-like feature of 2D-pupil and a new pupil edge feature in the local pupil area, and integrate them into the proposed pipeline. EPS was compared with two state-of-art methods on 130[Formula: see text]856 images in this work. Within an error threshold of 5 pixels, our method outperforms the comparison algorithms by 33.8% and 19.4%, respectively, on overage.
MASS PRODUCTION OF HFCVD DIAMOND-COATED WIRE-DRAWING DIES WITHOUT FILAMENT THROUGH THE HOLE
Authors: SONG XIN , WANG CHENG-CHUAN , WANG XIN-CHANG , SUN FANG-HONG
Published: December 2020

Hot filament chemical vapor deposition (HFCVD) diamond-coated small aperture wire-drawing dies from [Formula: see text] to [Formula: see text][Formula: see text]mm are in high demand. A new deposition technique without filaments through the inner hole of wire-drawing dies is proposed, accompanied with the specially designed fixtures. Temperature distribution on the deposition surfaces is studied by computational fluid dynamics (CFD) simulation based on the finite volume method (FVM); both case study and mass production simulations are accomplished. Excellent performance and uniform multilayer MCD/NCD/MCD/NCD films are successfully deposited on the inner-hole surfaces of total 16 cemented carbide (WC-6wt.%Co) wire-drawing dies with an aperture of [Formula: see text][Formula: see text]mm in one batch. Drawing results of gas shield welding wires show that the lifespan of the multilayer diamond coated wire-drawing dies is about 20 times of the uncoated cemented carbide dies and 2 times of the monolayer MCD coated dies.
Cs ADSORPTION ON GaAS(001) As-RICH β2 (2×4) AND Ga-RICH (4×2) RECONSTRUCTION PHASES: A FIRST-PRINCIPLES RESEARCH
Authors: YU XIAOHUA , SUN HUIXIA , SHAO GUIRONG
Published: December 2020

Using plane-wave ultrasoft pseudopotential method based on first-principles density functional theory (DFT), the adsorption of Cs atom on As-rich GaAs(001)[Formula: see text]([Formula: see text]) reconstruction phase and Ga-rich GaAs(001)([Formula: see text]) reconstruction phase are investigated. The adsorption energy, work function, dipole moment, ionicity, band structure and density of state (DOS) of Cs adsorbed GaAs [Formula: see text]([Formula: see text]) and ([Formula: see text]) models are calculated. The stability and electronic structure of Cs adsorbed GaAs [Formula: see text]([Formula: see text]) and ([Formula: see text]) models are compared. Result shows that [Formula: see text]([Formula: see text]) phase is stable than the ([Formula: see text]) phase and after that Cs adsorption [Formula: see text]([Formula: see text]) phase is more beneficial for photoemission.
On trees with domination number equal to edge-vertex roman domination number
Authors: Naresh Kumar H. , Venkatakrishnan Y. B.
Published: December 2020

An edge-vertex Roman dominating function (or just ev-RDF) of a graph [Formula: see text] is a function [Formula: see text] such that for each vertex [Formula: see text] either [Formula: see text] where [Formula: see text] is incident with [Formula: see text] or there exists an edge [Formula: see text] adjacent to [Formula: see text] such that [Formula: see text]. The weight of a ev-RDF is the sum of its function values over all edges. The edge-vertex Roman domination number of a graph [Formula: see text], denoted by [Formula: see text], is the minimum weight of an ev-RDF [Formula: see text]. We provide a characterization of all trees with [Formula: see text], where [Formula: see text] is the domination number of [Formula: see text]
Star chromatic number of Harary graphs
Authors: Suseendran Chitra , Tabrez Fathima
Published: December 2020

A proper vertex coloring of a graph [Formula: see text] is called a star coloring if every path on four vertices in [Formula: see text] is not 2-colored. The star chromatic number is the minimum number of colors required to star color [Formula: see text] and it is denoted by [Formula: see text]. In this paper, the star coloring of Harary graphs [Formula: see text], where [Formula: see text] is even and [Formula: see text] is odd, is discussed.
The Laurentian Great Lakes: A Biogeochemical Test Bed
Authors: Sterner Robert W.
Published: December 2020

The Laurentian Great Lakes are vast, spatially heterogeneous, and changing. Across these hydrologically linked basins, some conditions approach biogeochemical extremes for freshwater systems anywhere. Some of the biogeochemical processes operate over nearly as broad a range of temporal and spatial scales as is possible to observe in freshwater. What we know about the biogeochemistry of this system is strongly influenced by an intense focus on phosphorus loading, eutrophication, and partial recovery; therefore, some important biogeochemical processes are known in detail while others are scarcely described. These lakes serve as a life support system for tens of millions of people, and they generate trillions of dollars of economic activity. Many biogeochemical changes that have occurred have surprised us. Biogeochemistry affects how these lakes perform these functions and should be a higher research priority. ▪  The biogeochemical functioning of the Great Lakes affects tens of millions of people and trillions of dollars of economy, but our knowledge of their biogeochemistry is fragmentary. ▪  The history of environmental damage and recovery in the Great Lakes is long and includes many surprises. ▪  Large lakes such as the Great Lakes combine characteristics of small lakes and the world's oceans, making them worthy objects of study to advance fundamental understanding. ▪  The Great Lakes are understudied relative to their scale and importance.
My Trajectory in Molecular Reaction Dynamics and Spectroscopy
Authors: Gerber Robert Benny
Published: December 2020

This is the story of a career in theoretical chemistry during a time of dramatic changes in the field due to phenomenal growth in the availability of computational power. It is likewise the story of the highly gifted graduate students and postdoctoral fellows that I was fortunate to mentor throughout my career. It includes reminiscences of the great mentors that I had and of the exciting collaborations with both experimentalists and theorists on which I built much of my research.

This is an account of the developments of exciting scientific disciplines in which I was involved: vibrational spectroscopy, molecular reaction mechanisms and dynamics, e.g., in atmospheric chemistry, and the prediction of new, exotic molecules, in particular noble gas molecules.

From my very first project to my current work, my career in science has brought me the excitement and fascination of research. What a wonderful pursuit!
Development and Application of an Electrochemical Sensor for Hydroquinone in Pharmaceutical Products
Authors: Cotchim Suparat , Promsuwan Kiattisak , Dueramae Muslim , Duerama Sophuwan , Dueraning Anisah , Thavarungkul Panote , Kanatharana Proespichaya , Limbut Warakorn
Published: December 2020

In this work, a carboxylic acid-functionalized graphene (Gr-COOH)-modified glassy carbon electrode (GCE) (Gr-COOH/GCE) was developed and applied for the sensitive determination of hydroquinone in pharmaceutical products. Gr-COOH on a GCE was used as an adsorbent in adsorptive anodic stripping voltammetry (AdASV). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV) and AdASV were employed to characterize the surface morphology and electrochemical behavior of the Gr-COOH/GCE. The sensitivity of the Gr-COOH/GCE was 3, 7, and 10 times higher than those of a Gr/GCE, GCE-COOH and bare GCE, respectively. Several operational parameters, including the amount of Gr-COOH, preconcentration potential and preconcentration time, were optimized. Under optimum conditions, the peak current response linearly increased with the hydroquinone concentration in the range of 0.1–40.0μmol l−1(r = 0.999) with a high sensitivity of 19.86μA (μmol l−1)−1cm−2and a limit of detection of 0.04μmol l−1. This proposed modified electrode exhibited good repeatability, accuracy and precision. It also showed good anti-interference properties. This method was successfully applied to detect hydroquinone in skin-lightening products.
Induction of HO-1 by 5, 8-Dihydroxy-4

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,7-Dimethoxyflavone via Activation of ROS/p38 MAPK/Nrf2 Attenuates Thrombin-Induced Connective Tissue Growth Factor Expression in Human Cardiac Fibroblasts
Authors: Yang Chien-Chung , Hsiao Li-Der , Lin Hsin-Hui , Tseng Hui-Ching , Situmorang Jiro Hasegawa , Leu Yann-Lii , Yang Chuen-Mao
Published: December 2020

Heme oxygenase-1 (HO-1) has been shown to exert as an antioxidant and anti-inflammatory enzyme in cardiovascular inflammatory diseases. Flavonoids have been demonstrated to display anti-inflammatory and antioxidant effects through the induction of HO-1. 5,8-Dihydroxy-4

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,7-dimethoxyflavone (DDF), one of the flavonoid compounds, is isolated from Reevesia formosana. Whether DDF induced HO-1 expression on human cardiac fibroblasts (HCFs) remained unknown. Here, we found that DDF time- and concentration-dependently induced HO-1 protein and mRNA expression, which was attenuated by pretreatment with reactive oxygen species (ROS) scavenger N-acetyl cysteine (NAC) in HCFs. DDF-enhanced ROS generation was attenuated by NAC, but not by either diphenyleneiodonium chloride (DPI, Nox inhibitor) or MitoTempol (mitochondrial ROS scavenger). Interestingly, pretreatment with glutathione (GSH) inhibited DDF-induced HO-1 expression. The ratio of GSH/GSSG was time-dependently decreased in DDF-treated HCFs. DDF-induced HO-1 expression was attenuated by an inhibitor of p38 MAPK (p38i VIII) or siRNA, but not by MEK1/2 (PD98059) or JNK1/2 (SP600125). DDF-stimulated p38 MAPK phosphorylation was inhibited by GSH or p38i VIII. Moreover, DDF-induced HO-1 expression was mediated through Nrf2 phosphorylation and translocation into the nucleus which was attenuated by NAC or p38 siRNA. DDF also stimulated antioxidant response element (ARE) promoter activity which was inhibited by NAC, GSH, or p38i VIII. Interaction between Nrf2 and the ARE-binding sites on the HO-1 promoter was revealed by chromatin immunoprecipitation assay, which was attenuated by NAC, GSH, or p38i VIII. We further evaluated the functional effect of HO-1 expression on the thrombin-induced fibrotic responses. Our result indicated that the induction of HO-1 by DDF can attenuate the thrombin-induced connective tissue growth factor expression. These results suggested that DDF-induced HO-1 expression is, at least, mediated through the activation of the ROS-dependent p38 MAPK/Nrf2 signaling pathway in HCFs. Thus, the upregulation of HO-1 by DDF could be a candidate for the treatment of heart fibrosis.
Availability of Adequately Iodized Dietary Salt and Associated Factors in a Town of Southeast Ethiopia: A Community-Based Cross-Sectional Survey
Authors: Obssie Gadisa Fitala , Ketema Kassahun , Tekalegn Yohannes
Published: December 2020

Background. Iodine deficiency is the world’s major cause of preventable intellectual impairment, and nearly 2 billion people are at risk of iodine deficiency worldwide. Prevention and control of iodine deficiency disorders primarily aim at ensuring the intake of adequate iodine to maintain normal thyroid function. In our study area, studies regarding the coverage of adequately iodized salt at household level are meager. Hence, this study aimed to assess the magnitude of adequately iodized dietary salt at a household level in Kore Town, Southeast Ethiopia. Methods. A community-based cross-sectional study was conducted in the Kore town from August 1 to 30, 2019. A total of 394 households were selected for this study using a simple random sampling technique. The level of salt iodine content was determined using the rapid field test kit. Then, iodine contents of dietary salt were reported as <15 parts per million and ≥15 parts per million. Data regarding sociodemographic factors, knowledge of respondents about iodized salt, and iodized salt handling practices were collected through a face-to-face interview. The binary logistic regression model was used to assess the association between independent factors and the outcome variable. Statistical significance was declared atp<0.05. Result. Out of all the households, 223 (56.6%) had adequately iodized salt. Not exposing iodized salt to sunlight (AOR = 2.35, 95% CI: 1.1, 5.2), storing the salt at a dry or cold place [(AOR = 4.77, 95% CI: 1.39, 16.45) and (AOR = 8.23, 95% CI: 1.44, 47.19), respectively], and having good knowledge about iodized salt (AOR = 1.88, 95% CI: 1.18, 3.01) were significantly associated with the presence of adequately iodized salt at the household level. Conclusion. Availability of adequately iodized salt in the study area was far below the World Health Organization recommendation. Information regarding the importance and proper handling of iodized dietary salt should be communicated to the householders.
The Crosstalk between Calcium Ions and Aldosterone Contributes to Inflammation, Apoptosis, and Calcification of VSMC via the AIF-1/NF-κB Pathway in Uremia
Authors: Hao Jianbing , Tang Jie , Zhang Lei , Li Xin , Hao Lirong
Published: December 2020

Vascular calcification is a major complication of maintenance hemodialysis patients. Studies have confirmed that calcification mainly occurs in the vascular smooth muscle cells (VSMC) of the vascular media. However, the exact pathogenesis of VSMC calcification is still unknown. This study shows that the crosstalk between calcium and aldosterone via the allograft inflammatory factor 1 (AIF-1) pathway contributes to calcium homeostasis and VSMC calcification, which is a novel mechanism of vascular calcification in uremia. In vivo results showed that the level of aldosterone and inflammatory factors increased in calcified arteries, whereas no significant changes were observed in peripheral blood. However, the expression of inflammatory factors markedly increased in the peripheral blood of uremic rats without aortic calcification and gradually returned to normal levels with aggravation of aortic calcification. In vitro results showed that there was an interaction between calcium ions and aldosterone in macrophages or VSMC. Calcium induced aldosterone synthesis, and in turn, aldosterone also triggered intracellular calcium content upregulation in macrophages or VSMC. Furthermore, activated macrophages induced inflammation, apoptosis, and calcification of VSMC. Activated VSMC also imparted a similar effect on untreated VSMC. Finally, AIF-1 enhanced aldosterone- or calcium-induced VSMC calcification, and NF-κB inhibitors inhibited the effect of AIF-1 on VSMC. These in vivo and in vitro results suggest that the crosstalk between calcium ions and aldosterone plays an important role in VSMC calcification in uremia via the AIF-1/NF-κB pathway. Local calcified VSMC induced the same pathological process in surrounding VSMC, thereby contributing to calcium homeostasis and accelerating vascular calcification.