bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecological and evolutionary dynamics of interconnectedness and modularity
Authors: Nordbotten Jan M. , Levin Simon A. , Szathmáry Eörs , Stenseth Nils C.
Published: January 2018

Significance

This work contains two major theoretical contributions: Firstly, we define a general set of measures, referred to as interconnectedness, which generalizes and combines classical notions of diversity and modularity. Secondly, we analyze the temporal evolution of interconnectedness based on a microscale model of ecoevolutionary dynamics. This we do by providing a platform for understanding how and why macroecological phenomena change over long time scales. Such a platform allows us to show how the drivers of the dynamics of macroecological descriptors, such as interconnectedness, can be partitioned into three components: (i) ecologically driven change, (ii) evolutionarily driven change, and (iii) environmentally driven change.
Single-crystal metal growth on amorphous insulating substrates
Authors: Zhang Kai , Pitner Xue Bai , Yang Rui , Nix William D. , Plummer James D. , Fan Jonathan A.
Published: January 2018

Significance

Eliminating grain boundaries of metal structures is desirable for many electronic and nanooptical applications. However, a technique that can be used to grow large-scale patterned single-crystal metal on amorphous insulating substrate has not been demonstrated. In this work, we show that using liquid phase epitaxy, microstructures of single-crystal metal can be grown on amorphous insulating substrates such as silicon dioxide with high yield. The single-crystal metal can be further patterned on the insulating substrate with lithography into functional devices, which avoids the transfer, and is largely scalable. This technology platform will reduce the failure of metal structures in electronic systems, and enable more efficient plasmonic nanostructures.
Rice bran supplement prevents UVB-induced skin photoaging in vivo
Authors: Ha Su Jeong , Park Joon , Lee Jangho , Song Kyung-Mo , Um Min Young , Cho Suengmok , Jung Sung Keun
Published: January 2018

Although rice bran consumption is reportedly has numerous beneficial effects on human health, the relationship between rice bran and the prevention of photoaging has not been investigated in detail. We sought to investigate whether consumption of rice bran supplement (RBS) can elicit preventive effects against UVB-induced photoaging in vivo. Dorsal skin sections of hairless mice were exposed to UVB over 16 weeks. RBS consumption suppressed UVB-induced wrinkle formation and inhibited the loss of water content and epidermal thickening in the mouse skin. Western blot and immunohistochemical analyses revealed that repeated exposure to UVB upregulated matrix metalloproteinase-13 (MMP-13) and cyclooxygenase-2 (COX-2) expression, while consumption of RBS suppressed MMP-13 and COX-2 expression, as well as mitogen-activated protein kinase (MAPK) signaling pathways. These findings suggest that RBS could be a potential bioactive ingredient in nutricosmetics to inhibit wrinkle formation and water content loss via the suppression of COX-2 and MMP-13 expression.
Reproducibility of work ability and work functioning instruments
Authors: van Schaaijk A , Nieuwenhuijsen K , Frings-Dresen M H W , Sluiter J K
Published: January 2018

Background

Work ability (WA) and work functioning (WF) instruments can be useful in occupational health practice. The reproducibility of both instruments is important to their relevance for daily practice. Clinimetrics concerns the methodological and statistical quality of instruments and their performance in practice.

Aims

To assess the reproducibility of WA and WF instruments.

Methods

Dutch workers completed a questionnaire containing WA questions and the WF questionnaire twice with a 7-day interval between. The questionnaire included an appraisal of current general, physical and mental/emotional WA (0–10) and the composite WF questionnaire of 49 items (0–100). We measured reproducibility, reliability and agreement by calculating the intraclass correlation coefficient (ICC), the standard error of measurement (SEM) and the smallest detectable change (SDC).

Results

The answers of 104 respondents were available for analysis. General, physical and mental/emotional WA had ICC values of 0.52, 0.69 and 0.56, respectively. For WF, the ICC value was 0.85. For general WA, the SEM was 0.71. For physical and mental/emotional WA, the SEMs were 0.75 and 0.74, respectively. For general, physical and mental/emotional WA, the SDC was 1.98, 2.09 and 2.05 respectively. The SEM of the WF score was 4.78, and the SDC was 13.25.

Conclusions

The WA questions showed moderate reliability, while the WF instrument showed good reliability. Occupational health professionals can use the SDCs of the instruments to monitor changes in WA and WF in workers over time.
Rapid Reversal of Complete Binocular Blindness With High-Dose Corticosteroids and Lumbar Drain in a Solid Organ Transplant Recipient With Cryptococcal Meningitis and Immune Reconstitution Syndrome: First Case Study and Literature Review
Authors: Weiss Zoe , Mehta Nihaal , Aung Su Nandar , Migliori Michael , Farmakiotis Dimitrios
Published: January 2018

Blindness is a rare, devastating, usually permanent complication of cryptococcal meningitis (CM). We present the first case of complete vision loss in a solid organ transplant recipient with CM treated with placement of a lumbar drain who had a dramatic visual recovery that started after 3 doses of high-dose steroids.
The AFIP/ARP Atlases of Pathology Past, Present, and Future
Authors: DeLellis Ronald A. , Caton Mirlinda
Published: January 2018

The AFIP (Armed Forces Institute of Pathology) Atlases (Fascicles) have been in continuous publication for nearly 75 years and have enjoyed a highly regarded reputation for their excellence. Throughout this time period, more than 130 volumes, encompassing the 1st to 4th series have been published. Since their inception in the 1940’s, the Fascicles have evolved from loose-leafed atlases illustrated with black and white images, to hardbound monographs with full color images and expansion of scope, including relevant clinical information, cytopathology, and the most recent advances in immunohistochemistry and molecular diagnostics. Each of the volumes undergoes a rigorous review process by the Editor-in-Chief, Associate Editors, members of the Editorial Advisory Board, and external reviewers. The 5th series, under the editorial direction of Drs. Elizabeth Montgomery and Jason Hornick, is well underway and will include an Epub version and a virtual slide box, in addition to the hardbound book. The Atlases of Nontumor Pathology will also continue to be published. With the closure of the AFIP in 2011, the American Registry of Pathology (ARP) has assumed full responsibility for the publication of both the Tumor and Nontumor Fascicles.
Comprehensive Assessment of PD-L1 Staining Heterogeneity in Pulmonary Adenocarcinomas Using Tissue Microarrays
Authors: Gagné Andréanne , Enlow William , Pigeon Marc-Antoine , Orain Michèle , Turcotte Stéphane , Bossé Yohan , Joubert Philippe
Published: January 2018

Checkpoint inhibitors directed against programmed death receptor 1 (PD-1) and its ligand (PD-L1) changed the treatment of advanced lung non–small cell carcinomas. The decision to treat patients is influenced by PD-L1 expression by tumor cells, but evidence indicates that this staining is heterogenous within a tumor. As PD-L1 staining is tested mostly on biopsies, false negative results can occur due to sampling issues. The clinical impact of this heterogeneity has not been established. We selected 241 patients who underwent pulmonary resection for adenocarcinoma. Tissue microarrays were constructed with five 1 mm cores representative of the histologic patterns observed in each tumor and stained for PD-L1. For each core, the histologic pattern and the percentage of PD-L1 positive tumor cells were noted. Staining heterogeneity was defined as cases with both positive and negative cores at positivity thresholds of 1%, 10%, and 50% of tumor cells. At the 50% cut-off, 37.8% of patients were PD-L1 positive, whereas 22.4% showed staining heterogeneity. Among patients with 1 negative core, 26.5% also had a positive core and could have been misclassified based on 1 biopsy. Mean staining of PD-L1 was higher in solid (47.9%) and micropapillary (24.2%) patterns and was lower in acinar (14.1%), papillary (3.4%), and lepidic (6.4%) architectures. A significant proportion of patients presented a heterogenous staining for PD-L1. A total of 26.5% of patients negative on 1 core turned out to be positive on another core, which raises the consideration of rebiopsy, in particular when lepidic, acinar, or papillary patterns are observed on a biopsy.
The BAP1 deubiquitinase complex is a general transcriptional co-activator
Authors: Campagne Antoine , Zielinski Dina , Michaud Audrey , Corre Stéphanie Le , Dingli Florent , Chen Hong , Vassilev Ivaylo , Lee Ming-Kang , Servant Nicolas , Loew Damarys , Pasmant Eric , Postel-Vinay Sophie , Wassef Michel , Margueron Raphaël
Published: January 2018

InDrosophila, a complex consisting of Calypso and ASX catalyzes H2A deubiquitination and has been reported to act as part of the Polycomb machinery in transcriptional silencing. The mammalian homologs of these proteins (BAP1 and ASXL1/2/3, respectively), are frequently mutated in various cancer types, yet their precise functions remain unclear. Using an integrative approach based on isogenic cell lines generated with CRISPR/Cas9, we uncover an unanticipated role for BAP1 in gene activation. This function requires the assembly of an enzymatically active BAPl-associated core complex (BAP1.com) containing one of the redundant ASXL proteins. We investigated the mechanism underlying BAP1.com-mediated transcriptional regulation and show that it functions neither in synergy nor by antagonism with the Polycomb machinery. Instead, our results provide compelling evidence that BAP1.com acts as a general transcriptional co-activator.
Genealogies in Growing Solid Tumors
Authors: Rick Durrett Duke U.
Published: January 2018

Over the past two decades, the theory of tumor evolution has largely focused on the selective sweeps model. According to this theory, tumors evolve by a succession of clonal expansions that are initiated by driver mutations that have a fitness advantage over the resident types. A 2015 study of colon cancer [44] has suggested an alternative theory of tumor evolution, the so-called Big Bang model, in which all of the necessary driver mutations are acquired before expansion began, and the evolutionary dynamics within the expanding population are predominantly neutral. In this paper, we will describe a simple mathematical model inspired by work of Hallatschek and Nelson [25] that makes quantitative predictions about spatial patterns of genetic variability. While this model has some success in matching observed patterns in two dimensions, it fails miserably in three dimensions. Despite this failure, we think the model analyzed here will be a useful first step in building an accurate model.
A Novel Computational Framework to Predict the Impact of a Point Mutation on PDZ Domain Classification
Authors: Moinuddin Muhammad , Aftab Wasim , Memic Adnan
Published: January 2018

PDZ domains represent one of the most common protein homology regions playing key roles in several diseases. Point mutations (PM) in amino acid primary sequence of PDZ domains can alter domain functions by affecting for example, downstream phosphorylation, a pivotal process in biology. Our goal in this present study was to introduce a novel approach to investigate how point mutations within the Class 1, Class 2 and Class 1–2 PDZ domains could affect the changes in binding with their partner ligands and hence affect their classification. We focused on features in PDZ domains of various species including human, rat and mouse. However, our work represents a generic computational framework that could be used to analyze PM in any given PDZ sequence. We have adopted two different approaches to investigate the impact of PM. In the first approach, we have developed a statistical model using bigram frequencies of amino acids and employed six different similarity measures to contrast the bigram frequency distribution of a wild type sequence relevant to its point mutants. In the next approach, we developed a statistical method that incorporates the impact of bigram frequency history associated with each mutational site that we call history weighted conditional change in probabilities. In this PM study, we observed that the history weighted method performs best when compared to all other methods studied in terms of picking up sites in PDZ domain where a PM could flip the class. We anticipate that this method will present a step forward towards computational techniques unveiling PDZ domain point mutants that largely affect the protein-ligand binding, specificity and affinity. We hope that this and future studies could aid therapy in which PDZ mutations have been implicated as the main disease drivers such as the Usher syndrome.
Trade credit supply in African agro-food manufacturing industry: determinants and motives
Authors: Dary Stanley Kojo , James Jr Harvey S.
Published: January 2018

Purpose

The purpose of this paper is to examine the determinants and motives for supply of trade credit among agro-food manufacturing firms in African countries.

Design/methodology/approach

The paper uses a subsample of food manufacturing firms from World Bank Enterprise Survey in eight African countries in 2014. Two-limit Tobit models are specified for the determinants of trade credit supply (TCS) and the motives for TCS are inferred from the determinants. An instrumental variable two-limit Tobit model is estimated to check the endogeneity of trade credit received (TCR) in relation to trade credit supplied.

Findings

The level of TCS is significantly related with degree of product diversification, manager experience, level of TCR and overdraft availability. From the results, financing motives (particularly liquidity and redistribution) and commercial motives (particularly marketing and quality guarantee motives) for TCS are implied.

Research limitations/implications

The parameter estimates may contain both demand and supply effects as the two effects cannot be separated due to absence of information on firms’ customers in the data set. The results should be interpreted in this context.

Originality/value

The motives for TCS by agro-food firms is less understood in the agricultural finance literature and this paper makes an important contribution in this regard. In particular, the paper shows the degree of product diversification is directly associated with TCS, a relationship which has not been explored in the trade credit literature.
Teaching a sense of initiative and entrepreneurship with constructive alignment in tertiary non-business contexts
Authors: Morselli Daniele
Published: January 2018

Purpose

The purpose of this paper is to focus on a course in entrepreneurship education for students studying for a Masters in Educational Sciences at a Finnish university. The course was structured around the principles of constructive alignment and aimed to move beyond reflection on entrepreneurship towards action

Design/methodology/approach

The course was delivered in alignment with intended learning outcomes, teaching and learning activities, and assessment. Along with lectures, group work and peer-review activities, students prepared a career development plan as the course progressed, undertook a homework assignment, wrote a reflective journal, and sat the GET2 test twice.

Findings

Quantitative and qualitative analysis suggests that students developed more enterprising attitudes as result of participating in the course. This paper makes an argument in favour of entrepreneurship as a subject for all, a transformative experience capable of shaping the mindset in all who participate.

Originality/value

This paper shows how a course on entrepreneurial education based on a “through” approach can be taught at a tertiary level in places other than economics faculties or business schools. Most tertiary courses rely on “about” and “for” approaches to entrepreneurial education, are teacher-centred, and follow a behaviouristic or cognitive learning paradigm of knowledge transmission, as opposed to the student-centred constructivist approach deployed and described here.
Two-phase explicit CBS procedure for compressible viscous flow transport in porous materials
Authors: Cortellessa Gino , Arpino Fausto , Di Fraia Simona , Scungio Mauro
Published: January 2018

Purpose

In this work, a new two-phase version of the finite element-based Artificial Compressibility (AC) Characteristic-Based Split (CBS) algorithm is developed and applied for the first time to heat and mass transfer phenomena in porous media with associated phase change. The purpose of this study is to provide an alternative for the theoretical analysis and numerical simulation of multiphase transport phenomena in porous media. Traditionally, the more complex Separate Flow Model was used in which the vapour and liquid phases were considered as distinct fluids and mathematically described by the conservation laws for each phase separately, resulting in a large number of governing equations.

Design/methodology/approach

Even though the adopted mathematical model presents analogies with the conventional multicomponent mixture flow model, it is characterized by a considerable reduction in the number of the differential equations for the primary variables. The fixed-grid numerical formulation can be applied to the resolution of general problems that may simultaneously include a superheated vapour region, a two-phase zone and a sub-cooled liquid region in a single physical domain with irregular and moving phase interfaces in between. The local thermal non-equilibrium model is introduced to consider the heat exchange between fluid and solid within the porous matrix.

Findings

The numerical model is verified considering the transport phenomena in a homogenous and isotropic porous medium in which water is injected from one side and heated from the other side, where it leaves the computational domain in a superheated vapour state. Dominant forces are represented by capillary interactions and two-phase heat conduction. The obtained results have been compared with the numerical data available in the scientific literature.

Social implications

The present algorithm provides a powerful routine tool for the numerical modelling of complex two-phase transport processes in porous media.

Originality/value

For the first time, the stabilized AC-CBS scheme is applied to the resolution of compressible viscous flow transport in porous materials with associated phase change. A properly stabilized matrix inversion-free procedure employs an adaptive local time step that allows acceleration of the solution process even in the presence of large source terms and low diffusion coefficients values (near the phase change point).
Schlieren and Mie scattering techniques for the ECN “spray G” characterization and 3D CFD model validation
Authors: Piazzullo Daniele , Costa Michela , Allocca Luigi , Montanaro Alessandro , Rocco Vittorio
Published: January 2018

Purpose

This paper aims to study the heat transfer phenomenon occurring between heated walls and impinging fuel, showing the strict relationship between cooling effect after impingement and enhancing of wallfilm formation. The study focuses on a fundamental task in terms of pollutant emissions in internal combustion engines, aiming at giving a major contribution to the optimization of energy conversion systems in terms of environmental impact.

Design/methodology/approach

The paper is based on experimental campaigns relevant at taking measurements of an impinging spray over a heated wall in a confined vessel. The results, in both qualitative and quantitative terms (measurements of liquid and vapour radial penetration and thickness), are numerically reproduced by a computational model based on a Reynolds Averaged Navier Stokes approach, properly validated through customized sub-models.

Findings

The paper provides quantitative results about the agreement between radial penetration and vapour thickness between measurements and simulation, achieved by taking into account the cooling effect determined by the fuel impingement. This validation of the numerical model allows the author to give more considerations about the link between wall temperature and wallfilm formation.

Originality/value

This paper presents an original approach for the simulation of wall heat transfer, by imposing a boundary condition at the wall that may consider the heat conduction and temperature cooling given by fuel impingement in both lateral and normal directions. The classical Dirichlet boundary condition, characterized by imposing a fixed temperature value, is, instead, replaced by an approach based on calculating the unsteady process that couples the heat fluxes between the fluid and the solid material and within the solid itself.
Simulation of a macrosegregation benchmark with a meshless diffuse approximate method
Authors: Hatić Vanja , Mavrič Boštjan , Šarler Božidar
Published: January 2018

Purpose

The purpose of this paper is to simulate a macrosegregation solidification benchmark by a meshless diffuse approximate method. The benchmark represents solidification of Al 4.5 wt per cent Cu alloy in a 2D rectangular cavity, cooled at vertical boundaries.

Design/methodology/approach

A coupled set of mass, momentum, energy and species equations for columnar solidification is considered. The phase fractions are determined from the lever solidification rule. The meshless diffuse approximate method is structured by weighted least squares method with the second-order monomials for trial functions and Gaussian weight functions. The spatial localization is made by overlapping 13-point subdomains. The time-stepping is performed in an explicit way. The pressure-velocity coupling is performed by the fractional step method. The convection stability is achieved by upstream displacement of the weight function and the evaluation point of the convective operators.

Findings

The results show a very good agreement with the classical finite volume method and the meshless local radial basis function collocation method. The simulations are performed on uniform and non-uniform node arrangements and it is shown that the effect of non-uniformity of the node distribution on the final segregation pattern is almost negligible.

Originality/value

The application of the meshless diffuse approximate method to simulation of macrosegregation is performed for the first time. An adaptive upwind scheme is successfully applied to the diffuse approximate method for the first time.
Suprachoroidal shunts for treatment of glaucoma
Authors: Mauro Alessandro , Romano Mario R. , Romano Vito , Nithiarasu P.
Published: January 2018

Purpose

The purpose of this paper is to compare the fluid dynamic performance of two Aqueous Humor (AH) ocular drainage devices, the SOLX® Gold Micro Shunt (GMS) and the novel Silicon Shunt Device (SSD), implanted by surgeons in human eyes to reduce the IntraOcular Pressure towards physiological values, by draining the AH from the Anterior Chamber to the Suprachoroidal Space, to cure eyes with glaucoma.

Design/methodology/approach

The generalized porous medium model is solved to simulate the AH flow through the two ocular drainage devices and the surrounding porous tissues of the eye.

Findings

In the GMS, probable stagnation regions have been found, due to the very small AH velocity values inside the device and to the surrounding tissues, creating possible blockage and malfunction of the device. The simple microtubular geometry of the novel SSD allows to have a regular AH flow and to choose shunts with different diameters and/or with the presence of radial holes, based on patient needs, with consequent reduction of post-operative complications.

Research limitations/implications

The present model will be further developed taking into account the insertion of the present drainage devices inside the anterior section of the eye. The present results show the comparative fluid dynamic performance of the two shunts considered, and can be useful for surgeons to choose the adequate shunt, based on the required AH flow rate for a specific patient.

Practical implications

The present numerical approach, employing the generalized porous medium model, represents a useful tool to study the fluid dynamics of ocular drainage devices and to design these shunts, to reduce post-operative complications.

Originality/value

The generalized porous medium model is here applied for the first time to simulate the interaction of ocular drainage devices with the surrounding porous tissues of the eye.
Investigating antecedents and outcome of telepresence on a hotel’s website
Authors: Lee Seonjeong (Ally)
Published: January 2018

Purpose

This study aims to investigate the relationships among sensory, emotional and cognitive attributes on a hotel’s website, customers’ telepresence, their attitudes toward the hotel’s website, brand attitudes and their behavioral intentions, based on telepresence and parasocial interaction theories as theoretical backgrounds.

Design/methodology/approach

A cross-sectional, online, self-administered survey was conducted to examine the proposed framework from previous hotel guests in the USA, who booked the hotel via its website within the previous 12 months.

Findings

Results identified sensory and emotional attributes influenced customers’ telepresence; however, cognitive attributes did not affect telepresence on the hotel’s website. Telepresence then influenced customers’ attitudes toward the hotel’s website and their behavioral intentions. Both attitudes toward the hotel’s website and brand attitudes influenced customers’ behavioral intentions.

Originality/value

This study was the first study to propose the telepresence model in the hotel website context, investigating antecedents and outcomes of the telepresence.
Impact assessment in higher education: a strategic view from the UK
Authors: Ayres Ruth L.
Published: January 2018

Purpose

This paper focuses on the importance of impact in higher education from a strategic perspective, exploring its value to institutions, learners and prospective students in today’s higher education context, using the UK as a case study. The increasing prominence of impact assessment in higher education is discussed, with consideration given to the operational structures, tools and approaches which can be adopted to monitor and evaluate the impact of any strategic project or initiative introduced by a higher education provider.

Design/methodology/approach

This paper presents a strategic view of impact assessment in today’s higher education landscape.

Findings

The significance of impact assessment in higher education is discussed from a strategic perspective, drawing upon relevant studies, UK Government policy and initiatives. Consideration is given to the tools and approaches that can be adopted by higher education providers in assessing the impact of any strategic initiatives and projects that have been implemented.

Originality/value

The paper is of value to 'any higher education provider that is currently undertaking, or planning to deliver large-scale strategic projects and initiatives which have been designed to enhance the student learning experience.
A new two-stage grey evaluation decision-making method for interval grey numbers
Authors: Li Peng , Wei Cuiping
Published: January 2018

Purpose

In multi-criteria decision-making with interval grey number information, decision makers usually take a risk to rank or choose some very similar alternatives. Additionally, when evaluating only one alternative, decision makers can only obtain a specific value using traditional decision-making methods and may find it hard to cluster the alternatives to the “correct class” because these methods lack predetermined reference points. To overcome this problem, this paper aims to propose a two-stage grey decision-making method.

Design/methodology/approach

First, a new type of clustering method for interval grey numbers is designed by proposing a new possibility function for grey numbers. Based on this clustering method, a new grey clustering evaluation model for interval grey numbers is proposed by which decision makers can obtain the grade rating information of each alternative. Then, according to the grey clustering evaluation model, a new two-stage decision-making method is introduced to solve the problem that some alternatives are very similar by designing a grey comprehensive decision coefficient of alternatives.

Findings

The authors propose a new grey clustering evaluation model to deal with interval grey numbers. They design a new model to obtain the membership degree for the interval grey numbers and then propose a new grey clustering evaluation model, which can evaluate only one alternative by predefined grey classes. Then, by the grey comprehensive decision coefficient, a two-stage grey evaluation decision-making method is put forward to solve the problem that some alternatives are very close and hard to be distinguished.

Originality/value

A new grey clustering evaluation model is proposed, which can evaluate only one alternative by predefined grey classes. A two-stage grey evaluation decision-making method is given to solve the problem that some alternatives are very close and hard to be distinguished.
Nanophotonic technologies driving innovations in molecular sensing
Authors: Bogue Robert
Published: January 2018

Purpose

This paper aims to provide a technical insight into recent molecular sensor developments involving nanophotonic materials and phenomena.

Design/methodology/approach

Following an introduction, this highlights a selection of recent research activities involving molecular sensors based on nanophotonic technologies. It discusses chemical sensors, gas sensors and finally the role of nanophotonics in Raman spectroscopy. Brief concluding comments are drawn.

Findings

This shows that nanophotonic technologies are being applied to a diversity of molecular sensors and have the potential to yield devices with enhanced features such as higher sensitivity and reduced size. As several of these sensors can be fabricated with CMOS technology, potential exists for mass-production and significantly reduced costs.

Originality/value

This article illustrates how emerging nanophotonic technologies are set to enhance the capabilities of a diverse range of molecular sensors.
Enhanced photoelectric responses induced by visible light of acetone gas sensors based on CuO-ZnO nanocomposites at about room temperature
Authors: Miao Yuxin , Pan Guofeng , Sun Caixuan , He Ping , Cao Guanlong , Luo Chao , Zhang Li , Li Hongliang
Published: January 2018

Purpose

The purpose of this paper is to study the effect of doping, annealing temperature and visible optical excitation on CuO-ZnO nanocomposites’ acetone sensing properties and introduce an attractive candidate for acetone detection at about room temperature.

Design/methodology/approach

ZnO nanoparticles doped with CuO were prepared by sol-gel method, and the structure and morphology were characterized via X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and Brunauer-Emmett-Teller. The photoelectric responses of CuO-ZnO nanocomposites to cetone under the irradiation of visible light were investigated at about 30°C. The photoelectric response mechanism was also discussed with the model of double Schottky.

Findings

The doping of CuO enhanced performance of ZnO nanoparticles in terms of the photoelectric responses and the gas response and selectivity to acetone of ZnO nanoparticles, in addition, decreasing the operating temperature to about 30ºC. The optimum performance was obtained by 4.17% CuO-ZnO nanocomposites. Even at the operating temperature, about 30ºC, the response to 1,000 ppm acetone was significantly increased to 579.24 under the visible light irradiation.

Practical implications

The sensor fabricated by 4.17% CuO-ZnO nanocomposites exhibited excellent acetone-sensing characteristics at about 30ºC. It is promising to be applied in low power and miniature acetone gas sensors.

Originality/value

In the present research, a new nanocomposite material of CuO-ZnO was prepared by Sol-gel method. The optimum gas sensing properties to acetone were obtained by 4.17% CuO-ZnO nanocomposites at about 30ºC operating temperature when it was irradiated by visible light with the wavelength more than 420 nm.
Some Generalizations of Logistic Model
Authors: Dallakyan Gurgen
Published: January 2018

During the last decades models have been created to achieve the description and the representation of phenomena and bi- ological populations. These models are often an ordinary dieren- tial equations. A new population models are proposed in this article. This models are named the Generalized Logistic Models and it is an improvement-generalization of the already known, from the bibliog- raphy, Logistic Equation (Model). The solution of the new model is presented as well as its graph drown with Mathematica 11.0 and properties for a more complete and spherical view.
The parallel from Dr. Anastasopoulos' Legend-Classicatory of Diseases - Ancient Hospital of the Anchialos-Mesembria Hospital (1882-1883) to a contemporary European Short List of Disease Causes (2017)
Authors: Kyurkchiev Nikolay
Published: January 2018

The parallel from Dr. Anastasopoulos' Legend-Classicatory of Diseases - Ancient Hospital of the Anchialos-Mesembria Hospital (1882-1883) to a contemporary European Short List of Disease Causes (2017)
Paradigmatic variation of vowels in expressive speech: Acoustic description and dimensional analysis
Authors: Rilliard Albert , d'Alessandro Christophe , Evrard Marc
Published: January 2018

Acoustic variation in expressive speech at the syllable level is studied. As emotions or attitudes can be conveyed by short spoken words, analysis of paradigmatic variations in vowels is an important issue to characterize the expressive content of such speech segments. The corpus contains 160 sentences produced under seven expressive conditions (Neutral, Anger, Fear, Surprise, Sensuality, Joy, Sadness) acted by a French female speaker (a total of 1120 sentences, 13 140 vowels). Eleven base acoustic parameters are selected for voice source and vocal tract related feature analysis. An acoustic description of the expressions is drawn, using the dimensions of melodic range, intensity, noise, spectral tilt, vocalic space, and dynamic features. The first three functions of a discriminant analysis explain 95% of the variance in the data. These statistical dimensions are consistently associated with acoustic dimensions. Covariation of intensity and F0 explains over 80% of the variance, followed by noise features (8%), covariation of spectral tilt, and F0 (7%). On the basis of isolated vowels alone, expressions are classified with a mean accuracy of 78%.
Evolution of a Dominant Natural Isolate of Escherichia coli in the Human Gut over the Course of a Year Suggests a Neutral Evolution with Reduced Effective Population Size
Authors: Ghalayini Mohamed , Launay Adrien , Bridier-Nahmias Antoine , Clermont Olivier , Denamur Erick , Lescat Mathilde , Tenaillon Olivier
Published: January 2018

In vitro
and
in vivo
evolution experiments on
Escherichia coli
revealed several principles of bacterial adaptation. However, few data are available in the literature describing the behavior of
E. coli
in its natural environment. We attempted here to study the evolution in the human gut of a commensal dominant
E. coli
clone, ED1a belonging to the B2 phylogroup, through a longitudinal genomic study. We sequenced 24 isolates sampled at three different time points within a healthy individual over almost a year. We computed a mutation rate of 6.90 × 10
−7
mutations per base per year of the chromosome for
E. coli
ED1a in healthy human gut. We observed very limited genomic diversity and could not detect any evidence of selection, in contrast to what is observed in experimental evolution over a similar length of time. We therefore suggest that ED1a, being well adapted to the healthy human gut, evolves mostly neutrally with a low effective population size (

N
e

of ≈500 to 1,700).

IMPORTANCE
In this study, we follow the genomic fate of a dominant clone of
Escherichia coli
in the human gut of a healthy individual over about a year. We could compute a low annual mutation rate that supports low diversity, and we could not retrieve any clear signature of selection. These observations support a neutral evolution of
E. coli
in the human gut, compatible with a very limited effective population size that deviates drastically with the observations made previously in experimental evolution.
Elucidating Waterborne Pathogen Presence and Aiding Source Apportionment in an Impaired Stream
Authors: Weidhaas Jennifer , Anderson Angela , Jamal Rubayat
Published: January 2018

Fecal indicator bacteria (FIB) are the basis for water quality regulations and are considered proxies for waterborne pathogens when conducting human health risk assessments. The direct detection of pathogens in water and simultaneous identification of the source of fecal contamination are possible with microarrays, circumventing the drawbacks to FIB approaches. A multigene target microarray was used to assess the prevalence of waterborne pathogens in a fecally impaired mixed-use watershed. The results indicate that fecal coliforms have improved substantially in the watershed since its listing as a 303(d) impaired stream in 2002 and are now near United States recreational water criterion standards. However, waterborne pathogens are still prevalent in the watershed, as viruses (bocavirus, hepatitis E and A viruses, norovirus, and enterovirus G), bacteria (
Campylobacter
spp.,
Clostridium
spp., enterohemorrhagic and enterotoxigenic
Escherichia coli
, uropathogenic
E. coli
,
Enterococcus faecalis
,
Helicobacter
spp.,
Salmonella
spp., and
Vibrio
spp.), and eukaryotes (
Acanthamoeba
spp.,
Entamoeba histolytica
, and
Naegleria fowleri
) were detected. A comparison of the stream microbial ecology with that of sewage, cattle, and swine fecal samples revealed that human sources of fecal contamination dominate in the watershed. The methodology presented is applicable to a wide range of impaired streams for the identification of human health risk due to waterborne pathogens and for the identification of areas for remediation efforts.

IMPORTANCE
The direct detection of waterborne pathogens in water overcomes many of the limitations of the fecal indicator paradigm. Furthermore, the identification of the source of fecal impairment aids in identifying areas for remediation efforts. Multitarget gene microarrays are shown to simultaneously identify waterborne pathogens and aid in determining the sources of impairment, enabling further focused investigations. This study shows the use of this methodology in a historically impaired watershed in which total maximum daily load reductions have been successfully implemented to reduce risk. The results suggest that while the fecal indicators have been reduced more than 96% and are nearing recreational water criterion levels, pathogens are still detectable in the watershed. Microbial source tracking results show that additional remediation efforts are needed to reduce the impact of human sewage in the watershed.
An IgaA/UmoB Family Protein from Serratia marcescens Regulates Motility, Capsular Polysaccharide Biosynthesis, and Secondary Metabolite Production
Authors: Stella Nicholas A. , Brothers Kimberly M. , Callaghan Jake D. , Passerini Angelina M. , Sigindere Cihad , Hill Preston J. , Liu Xinyu , Wozniak Daniel J. , Shanks Robert M. Q.
Published: January 2018

Secondary metabolites are an important source of pharmaceuticals and key modulators of microbe-microbe interactions. The bacteriumSerratia marcescensis part of theEnterobacteriaceaefamily of eubacteria and produces a number of biologically active secondary metabolites. In this study, we screened for novel regulators of secondary metabolites synthesized by a clinical isolate ofS. marcescensand found mutations in a gene for an uncharacterized UmoB/IgaA family member here namedgumB. Mutation ofgumBconferred a severe loss of the secondary metabolites prodigiosin and serratamolide. ThegumBmutation conferred pleiotropic phenotypes, including altered biofilm formation, highly increased capsular polysaccharide production, and loss of swimming and swarming motility. These phenotypes corresponded to transcriptional changes infimA,wecA, andflhD. Unlike other UmoB/IgaA family members,gumBwas found to be not essential for growth inS. marcescens, yetigaAfromSalmonella enterica,yrfFfromEscherichia coli, and an uncharacterized predicted ortholog fromKlebsiella pneumoniaecomplemented thegumBmutant secondary metabolite defects, suggesting highly conserved function. These data support the idea that UmoB/IgaA family proteins are functionally conserved and extend the known regulatory influence of UmoB/IgaA family proteins to the control of competition-associated secondary metabolites and biofilm formation.

IMPORTANCEIgaA/UmoB family proteins are found in members of theEnterobacteriaceaefamily of bacteria, which are of environmental and public health importance. IgaA/UmoB family proteins are thought to be inner membrane proteins that report extracellular stresses to intracellular signaling pathways that respond to environmental challenge. This study introduces a new member of the IgaA/UmoB family and demonstrates a high degree of functional similarity between IgaA/UmoB family proteins. Moreover, this study extends the phenomena controlled by IgaA/UmoB family proteins to include the biosynthesis of antimicrobial secondary metabolites.
Potential Immunological Biomarkers for Detection of Mycobacterium tuberculosis Infection in a Setting Where M. tuberculosis Is Endemic, Ethiopia
Authors: Teklu Takele , Kwon Keehwan , Wondale Biniam , HaileMariam Milkessa , Zewude Aboma , Medhin Girmay , Legesse Mengistu , Pieper Rembert , Ameni Gobena
Published: January 2018

Accurate diagnosis and early treatment of tuberculosis (TB) and latent TB infection (LTBI) are vital to prevent and control TB. The lack of specific biomarkers hinders these efforts. This study's purpose was to screen immunological markers that discriminate
Mycobacterium tuberculosis
infection outcomes in a setting where it is endemic, Ethiopia. Whole blood from 90 participants was stimulated using the ESAT-6/CFP-10 antigen cocktail. The interferon gamma (IFN-γ)-based QuantiFERON diagnostic test was used to distinguish between LTBI and uninfected control cases. Forty cytokines/chemokines were detected from antigen-stimulated plasma supernatants (SPSs) and unstimulated plasma samples (UPSs) using human cytokine/chemokine antibody microarrays. Statistical tests allowed us to identify potential biomarkers that distinguish the TB, LTBI, and healthy control groups. As expected, the levels of IFN-γ in SPSs returned a high area under the receiver operating characteristic curve (AUC) value comparing healthy controls and LTBI cases (Z = 0.911;
P
< 0.001). The SPS data also indicated that interleukin 17 (IL-17) abundance discriminates LTBI from healthy controls (Z = 0.763;
P
= 0.001). RANTES and MIP-1β were significantly elevated in SPSs of TB-infected compared to healthy controls (
P
< 0.05), while IL-12p40 and soluble tumor necrosis factor receptor II (sTNF-RII) were significantly increased in active TB cases compared to the combined LTBI and control groups (
P
< 0.05). Interestingly, quantitative changes for RANTES were observed using both SPSs and UPSs, with
P
values of 0.013 and 0.012, respectively, in active TB versus LTBI cases and 0.001 and 0.002, respectively, in active TB versus healthy controls. These results encourage biomarker verification studies for IL-17 and RANTES. Combinations of these cytokines may complement IFN-γ measurements to diagnose LTBI and distinguish active TB from LTBI cases.
Cessation from Smoking Improves Innate Host Defense and Clearance of Experimentally Inoculated Nasal Staphylococcus aureus
Authors: Cole Amy L. , Schmidt-Owens Mary , Beavis Ashley C. , Chong Christine F. , Tarwater Patrick M. , Schaus James , Deichen Michael G. , Cole Alexander M.
Published: January 2018

Staphylococcus aureus
nasal carriage is transient in most humans and usually benign, but dissemination of
S. aureus
to extranasal sites causes the majority of clinical infections, and
S. aureus
is a major cause of serious infections in the United States. A better understanding of innate nasal decolonization mechanisms is urgently needed, as are relevant models for studying
S. aureus
clearance. Here, we screened a population of healthy smokers for nasal
S. aureus
carriage and compared the participants' abilities to clear experimentally applied nasal
S. aureus
before and after completion of a smoking cessation program. We determined that cigarette smoking increases the mean nasal
S. aureus
load (2.6 × 10
4
CFU/swab) compared to the load observed in healthy nonsmokers (1.7 × 10
3
CFU/swab) and might increase the rate of
S. aureus
nasal carriage in otherwise-healthy adults: 22 of 99 smokers carried
S. aureus
at the screening visit, while only 4 of 30 nonsmokers screened positive during the same time period. Only 6 of 19 experimental inoculation studies in active smokers resulted in
S. aureus
clearance within the month of follow-up, while in the cessation group, 6 of 9 subjects cleared nasal
S. aureus
and carriage duration averaged 21 ± 4 days. Smoking cessation associated with enhanced expression of
S. aureus
-associated interleukin-1β (IL-1β) and granulocyte colony-stimulating factor (G-CSF) in nasal fluids. Participants who failed to clear
S. aureus
exhibited a higher nasal
S. aureus
load and elevated nasal interleukin-1 receptor antagonist (IL-1RA) expression at the preexperiment study visits. We conclude that smokers exhibit higher
S. aureus
loads than nonsmokers and that innate immune pathways, including G-CSF expression and signaling through the IL-1 axis, are important mediators of nasal
S. aureus
clearance.