bluuebunny/crossref_metadata_2025 huggingface dataset:
Precursors of Role-Based Access Control Design in KMS: A Conceptual Framework
Authors: Nyame Gabriel , Qin Zhiguang
Published: June 2020

Role-based access control (RBAC) continues to gain popularity in the management of authorization concerning access to knowledge assets in organizations. As a socio-technical concept, the notion of role in RBAC has been overemphasized, while very little attention is given to the precursors: role strain, role ambiguity, and role conflict. These constructs provide more significant insights into RBAC design in Knowledge Management Systems (KMS). KMS is the technology-based knowledge management tool used to acquire, store, share, and apply knowledge for improved collaboration and knowledge-value creation. In this paper, we propose eight propositions that require future research concerning the RBAC system for knowledge security. In addition, we propose a model that integrates these precursors and RBAC to deepen the understanding of these constructs. Further, we examine these precursory constructs in a socio-technical fashion relative to RBAC in the organizational context and the status–role relationship effects. We carried out conceptual analysis and synthesis of the relevant literature, and present a model that involves the three essential precursors that play crucial roles in role mining and engineering in RBAC design. Using an illustrative case study of two companies where 63 IT professionals participated in the study, the study established that the precursors positively and significantly increase the intractability of the RBAC system design. Our framework draws attention to both the management of organizations and RBAC system developers about the need to consider and analyze the precursors thoroughly before initiating the processes of policy engineering, role mining, and role engineering. The propositions stated in this study are important considerations for future work.
Effect of a Coccolithophore Bloom on the Underwater Light Field and the Albedo of the Water Column
Authors: Kopelevich Oleg , Sheberstov Sergey , Vazyulya Svetlana
Published: June 2020

The goal of this work is to study the influence of coccolithophore blooms on the underwater light field and albedo of the water column. A coccolithophore is a single-celled alga with spherical cells surrounded by disk-shaped calcite plates (coccolites), which produce strong light scattering. Because of that, we can observe coccolithophore blooms on satellite ocean color images. We calculated the angular underwater radiance distributions and their integral parameters by the exact numerical method with the input parameters, corresponding to real conditions observed in the Barents Sea and Black Sea. Using the results of the exact calculations, we estimated, for various situations, the accuracy of the approximating formulas applied to the assessment of the water radiance reflectance and the diffuse attenuation coefficients and we make recommendations for their application. As a finding of practical importance, we can note the estimate of the accuracy of the widely used Gordon’s formula for the diffuse attenuation coefficient; this formula results in large errors under strong coccolithophore blooms. We also mention the interesting and important results concerning the features of the asymptotic regime under such conditions.
Validation and Application of a New Software Tool Implementing the PISA Design Methodology
Authors: Brinkgreve Ronald , Lisi Diego , Lahoz Miquel , Panagoulias Stavros
Published: June 2020

The PISA (Pile Soil Analysis) research project has resulted in a new methodology for the design of offshore wind turbine monopile foundations. A new software tool called PLAXIS Monopile Designer (MoDeTo) has been developed that automates the PISA design methodology. It facilitates the calibration of the so-called soil reaction curves by automated three-dimensional finite element calculations and it allows for a quick design of monopiles using the calibrated soil reaction curves in a one-dimensional finite element model based on Timoshenko beam theory. The monopile design approach has been validated for sand- and clay-type soils which are common in North Sea soil deposits. The paper presents a validation exercise based on the PISA research project proposal of a rule-based parametric model—General Dunkirk Sand Model (GDSM)—for Dunkirk sand as well as an application of the tool for a project involving an offshore wind turbine on a monopile foundation in sandy layered soil in which the PISA design is compared to the conventional API design. The paper concludes with a discussion of the results and the differences between the various methods.
Perspective Review on Subsea Jet Trenching Technology and Modeling
Authors: Atangana Njock Pierre Guy , Zheng Qian , Zhang Ning , Xu Ye-Shuang
Published: June 2020

This paper presents a comprehensive review on subsea jet trenching technology via a critical analysis of its principle, mechanism, devices, modeling approaches, as well as properties of subsea sediments. This review shows that the success of jet trenching operations is closely related to some key factors including the soil conditions, trencher specifications, and characteristics of pipelines or cables. Three case histories are presented to demonstrate the importance of these key factors and their interrelationships. This paper also points out a number of challenges pertaining to the implementation of the jet trenching method in carbonate sediments, as well as some limitations and gaps in the existing modeling approaches. Future perspective researches that are recommended to develop: (1) promising theories, like turbulent submerged flow, and (2) robust numerical approaches, such as the smoothed particle hydrodynamics (SPH) and material point method (MPM) to substantiate the experimental experience and reveal possible hidden mechanisms.
Channels of Labour Control in Organic Farming: Toward a Just Agroecological Transition for Sub-Saharan Africa
Authors: Bottazzi Patrick , Boillat Sébastien , Marfurt Franziska , Seck Sokhna Mbossé
Published: June 2020

Agroecological farming has long been described as more fulfilling than conventional agriculture, in terms of farmers’ labour and sense of autonomy. These assumptions must be reconsidered with adequate theoretical perspectives and with the empirical experience of recent studies. This paper introduces the concept of channels of labour control in agriculture based on four initiatives in Senegalese agroecological horticulture. We build on Bourdieu’s theory of social fields to elaborate a framework that articulates multiple channels of labour control with the type of capital or surplus values structuring power relations during labour processes. Although each of the four agroecological initiatives place a clear emphasis on improving farmers’ well-being, various top-down channels of labour control exist, maintaining most farmworkers as technical demonstrators rather than agents of transformation. These constraints stem from dependence on foreign funding, enforcement of uncoordinated organic standards, and farmers’ incorporation of cultural values through interplays of knowledge and symbolic power with initiative promotors. Pressure on agricultural workers is exacerbated by the context of the neo-liberalisation of Senegalese agriculture and increasingly difficult climatic conditions. A more holistic approach of agroecological initiatives is needed, including the institutionalisation of protected markets for their products, farmers’ inclusion in agroecosystem governance and inclusiveness in the co-production of agroecological knowledge, taking cultural patterns of local communities into account. Recent attempts to scale-up and politicise agroecology through farmers’ organisations, advocacy NGOs, and municipalities may offer new perspectives for a just agroecological transition in sub-Saharan Africa.
Adsorption of Cadmium, Manganese and Lead Ions from Aqueous Solutions Using Spent Coffee Grounds and Biochar Produced by Its Pyrolysis in the Fluidized Bed Reactor
Authors: Chwastowski Jarosław , Bradło Dariusz , Żukowski Witold
Published: June 2020

The adsorption process of cadmium ions (Cd), manganese ions (Mn) and lead ions (Pb) onto the spent coffee grounds (SCG) and activated spent coffee grounds (biochar, A-SCG) was investigated. The SCG activation was carried out in the pyrolysis process in a fluidized bed reactor. scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) measurements and CHN analysis were used in order to define the differences between biomaterials. In the study the different mass of materials (0.2–0.5 g) and constant heavy metal volume and concentration (20 cm3/100 ppm) were investigated on the adsorption process. In order to describe the sorption parameters the Langmuir, Freundlich and Temkin isotherms were used. The maximum adsorption for biochar reached 22.3 mg/g for Pb ions, 19.6 mg/g for Mn ions and 19.4 mg/g for Cd ions which were noticeably higher than the results obtained for spent coffee grounds which reached 13.6 mg/g for Pb ions, 13.0 mg/g for Mn ions and 11.0 mg/g for Cd ions. Metal ion adsorption on both SCG and A-SCG was best described by the Langmuir model, thus chemisorption was a dominant type of adsorption. Studying the kinetics of the sorption process, one can see that the process is of a chemical nature according to the best fit of the pseudo-second rate order model. The obtained results show that the chosen sorbents can be used for the removal of cadmium, manganese and lead compounds from aqueous solutions with high efficiency.
Application-Oriented Growth of a Molybdenum Disulfide (MoS2) Single Layer by Means of Parametrically Optimized Chemical Vapor Deposition
Authors: Tummala Pinakapani , Lamperti Alessio , Alia Mario , Kozma Erika , Nobili Luca Giampaolo , Molle Alessandro
Published: June 2020

In the 2D material framework, molybdenum disulfide (MoS2) was originally studied as an archetypical transition metal dichalcogenide (TMD) material. The controlled synthesis of large-area and high-crystalline MoS2 remains a challenge for distinct practical applications from electronics to electrocatalysis. Among the proposed methods, chemical vapor deposition (CVD) is a promising way for synthesizing high-quality MoS2 from isolated domains to a continuous film because of its high flexibility. Herein, we report on a systematic study of the effects of growth pressure, temperature, time, and vertical height between the molybdenum trioxide (MoO3) source and the substrate during the CVD process that influence the morphology, domain size, and uniformity of thickness with controlled parameters over a large scale. The substrate was pretreated with perylene-3,4,9,10-tetracarboxylic acid tetrapotassium salt (PTAS) seed molecule that promoted the layer growth of MoS2. Further, we characterized the as-grown MoS2 morphologies, layer quality, and physical properties by employing scanning electron microscopy (SEM), Raman spectroscopy, and photoluminescence (PL). Our experimental findings demonstrate the effectiveness and versatility of the CVD approach to synthesize MoS2 for various target applications.
Insights into In Vitro Wound Closure on Two Biopolyesters—Polylactide and Polyhydroxyoctanoate
Authors: Witko Tomasz , Solarz Daria , Feliksiak Karolina , Haraźna Katarzyna , Rajfur Zenon , Guzik Maciej
Published: June 2020

Two bio-based polymers have been compared in this study, namely: polylactide (PLA) and polyhydroxyoctanoate (PHO). Due to their properties such as biocompatibility, and biointegrity they are considered to be valuable materials for medical purposes, i.e., creating scaffolds or wound dressings. Presented biopolymers were investigated for their impact on cellular migration strategies of mouse embryonic fibroblasts (MEF) 3T3 cell line. Advanced microscopic techniques, including confocal microscopy and immunofluorescent protocols, enabled the thorough analysis of the cell shape and migration. Application of wound healing assay combined with dedicated software allowed us to perform quantitative analysis of wound closure dynamics. The outcome of the experiments demonstrated that the wound closure dynamics for PLA differs from PHO. Single fibroblasts grown on PLA moved 1.5-fold faster, than those migrating on the PHO surface. However, when a layer of cells was considered, the wound closure was by 4.1 h faster for PHO material. The accomplished work confirms the potential of PLA and PHO as excellent candidates for medical applications, due to their properties that propagate cell migration, vitality, and proliferation—essential cell processes in the healing of damaged tissues.
One Step before 3D Printing—Evaluation of Imaging Software Accuracy for 3-Dimensional Analysis of the Mandible: A Comparative Study Using a Surface-to-Surface Matching Technique
Authors: Lo Giudice Antonino , Ronsivalle Vincenzo , Grippaudo Cristina , Lucchese Alessandra , Muraglie Simone , Lagravère Manuel O. , Isola Gaetano
Published: June 2020

The accuracy of 3D reconstructions of the craniomaxillofacial region using cone beam computed tomography (CBCT) is important for the morphological evaluation of specific anatomical structures. Moreover, an accurate segmentation process is fundamental for the physical reconstruction of the anatomy (3D printing) when a preliminary simulation of the therapy is required. In this regard, the objective of this study is to evaluate the accuracy of four different types of software for the semiautomatic segmentation of the mandibular jaw compared to manual segmentation, used as a gold standard. Twenty cone beam computed tomography (CBCT) with a manual approach (Mimics) and a semi-automatic approach (Invesalius, ITK-Snap, Dolphin 3D, Slicer 3D) were selected for the segmentation of the mandible in the present study. The accuracy of semi-automatic segmentation was evaluated: (1) by comparing the mandibular volumes obtained with semi-automatic 3D rendering and manual segmentation and (2) by deviation analysis between the two mandibular models. An analysis of variance (ANOVA) was used to evaluate differences in mandibular volumetric recordings and for a deviation analysis among the different software types used. Linear regression was also performed between manual and semi-automatic methods. No significant differences were found in the total volumes among the obtained 3D mandibular models (Mimics = 40.85 cm3, ITK-Snap = 40.81 cm3, Invesalius = 40.04 cm3, Dolphin 3D = 42.03 cm3, Slicer 3D = 40.58 cm3). High correlations were found between the semi-automatic segmentation and manual segmentation approach, with R coefficients ranging from 0,960 to 0,992. According to the deviation analysis, the mandibular models obtained with ITK-Snap showed the highest matching percentage (Tolerance A = 88.44%, Tolerance B = 97.30%), while those obtained with Dolphin 3D showed the lowest matching percentage (Tolerance A = 60.01%, Tolerance B = 87.76%) (p < 0.05). Colour-coded maps showed that the area of greatest mismatch between semi-automatic and manual segmentation was the condylar region and the region proximate to the dental roots. Despite the fact that the semi-automatic segmentation of the mandible showed, in general, high reliability and high correlation with the manual segmentation, caution should be taken when evaluating the morphological and dimensional characteristics of the condyles either on CBCT-derived digital models or physical models (3D printing).
Effect of Carbon Nanotube and Styrene-Acrylic Emulsion Additives on Microstructure and Mechanical Characteristics of Cement Paste
Authors: Fan Jie , Li Gengying , Deng Sijie , Deng Chengwei , Wang Zhongkun , Zhang Zhijun
Published: June 2020

Carbon nanotubes (CNTs) are considered as one of the ideal modifiers of cement materials, since CNTs can improve the mechanical properties of cement paste effectively. However, the interfacial interaction between CNTs and the cement matrix is weak. Moreover, it is difficult to disperse CNTs within cement paste. To overcome these shortages, in this study, CNTs were firstly dispersed into a styrene-acrylic emulsion (SAE). Then the homo-dispersion CNT/SAE emulsion was incorporated into cement paste. The effect of the CNT/SAE hybrid-system on the mechanical properties and microstructure of cement paste was studied. For purposes of comparison, the properties of cement paste mono incorporating CNTs or SAE are also investigated. The results show that CNT/SAE network films could be observed in cement paste by using a field emission scanning electron microscope (FESEM). These network films could bridge the cracks and refine the pores of a cement matrix. Infrared analysis and Raman spectroscopy show that the CNT/SAE hybrid modifier has stronger interfacial adhesion and better load transfer ability over the mono adding of CNTs and SAE emulsion. As a result, the hybrid addition of CNT/SAE significantly improved the flexural strength of cement paste. Especially, the addition of 0.1% CNTs and 15% SAE by mass of cement improved the 28-day flexural strength of cement paste by 21% and 25% as compared to the mono addition of CNTs or SAE, respectively.
Rate of Convergence and Periodicity of the Expected Population Structure of Markov Systems that Live in a General State Space
Authors: Vassiliou P. -C. G.
Published: June 2020

In this article we study the asymptotic behaviour of the expected population structure of a Markov system that lives in a general state space (MSGS) and its rate of convergence. We continue with the study of the asymptotic periodicity of the expected population structure. We conclude with the study of total variability from the invariant measure in the periodic case for the expected population structure of an MSGS.
A Geometry-Based Guidance Law to Control Impact Time and Angle under Variable Speeds
Authors: Yan Xinghui , Kuang Minchi , Zhu Jihong
Published: June 2020

To provide a feasible solution for a variable speed unmanned aerial vehicle (UAV) to home on a target with impact time and angle constraints, this paper presents a novel geometry-based guidance law composed of trajectory reshaping and tracking. A trajectory generation process using Bezier curves is introduced to satisfy the impact time and angle constraints under time-varying speed. The impact angle is satisfied by driving the UAV along a specified ending line. The impact time is satisfied by controlling the trajectory length, which is realized through adjusting one Bezier curve end point along the ending line. The adjustable range of this end point, along with the maximum trajectory curvature, is analyzed to ensure that the trajectory is flyable. Guidance command is generated using inverse dynamics. Numerical simulations under various scenarios are demonstrated to illustrate the performance and validate the effectiveness of the proposed method.
On a Conjecture of Alzer, Berg, and Koumandos
Authors: Matejíčka Ladislav
Published: June 2020

In this paper, we find a solution of an open problem posed by Alzer, Berg, and Koumandos: determine ( α , m ) ∈ R + × N such that the function x α | ψ ( m ) ( x ) | is completely monotonic on ( 0 , ∞ ) , where ψ ( x ) denotes the logarithmic derivative of Euler’s gamma function.
Evaluation of Surgical Treatment of Oroantral Fistulae in Smokers Versus Non-Smokers
Authors: Sella Adi , Ben-Zvi Yehonatan , Gillman Leon , Avishai Gal , Chaushu Gavriel , Rosenfeld Eli
Published: June 2020

Background and Objectives: Smoking has been found to interfere with wound healing processes. Therefore, the purpose of this study was to compare surgical treatment of oroantral fistulae (OAFs) in smokers and non-smokers. Materials and Methods: Medical records of all consecutive patients who underwent surgical closure of OAFs between 2003 and 2016 at the oral and maxillofacial surgery department, Rabin Medical Center, Israel were reviewed. Patients’ demographic data, preoperative signs and symptoms, surgical method of repair, and postoperative complications were recorded. Results: The cohort consisted of 38 smokers and 59 non-smokers. Age and gender distributions were similar in both groups. The main etiology in both groups was tooth extraction, followed by pre-prosthetic surgery in smokers and odontogenic infection in non-smokers (p = 0.02). Preoperative conditions were not significantly different between smokers and non-smokers in terms of size of soft tissue fistula and bony defect, chronic sinusitis and foreign bodies inside the sinus. OAFs were repaired by local soft tissue flaps without consideration of smoking status. Smokers experienced more moderate-severe postoperative pain (p = 0.05) and requested more weak opioids (p = 0.06). Postoperative complications included infection, delayed wound healing, residual OAF, pain, sensory disturbances and sino nasal symptoms. These were mostly minor and tended to be more frequent in smokers (p = 0.35). Successful closure of OAFs was obtained in all patients except one smoker who required revision surgery. Conclusions: Smokers may be more susceptible to OAFs secondary to preprosthetic surgery. In this cohort, there was no statistically significant difference in outcome between smokers and non-smokers in terms of failure. However, smokers tended to have more severe postoperative pain and discomfort and to experience more postoperative complications. Further studies with larger sample sizes should be conducted to validate these results.
Solid-Contact Ion-Selective Electrodes: Response Mechanisms, Transducer Materials and Wearable Sensors
Authors: Lyu Yan , Gan Shiyu , Bao Yu , Zhong Lijie , Xu Jianan , Wang Wei , Liu Zhenbang , Ma Yingming , Yang Guifu , Niu Li
Published: June 2020

Wearable sensors based on solid-contact ion-selective electrodes (SC-ISEs) are currently attracting intensive attention in monitoring human health conditions through real-time and non-invasive analysis of ions in biological fluids. SC-ISEs have gone through a revolution with improvements in potential stability and reproducibility. The introduction of new transducing materials, the understanding of theoretical potentiometric responses, and wearable applications greatly facilitate SC-ISEs. We review recent advances in SC-ISEs including the response mechanism (redox capacitance and electric-double-layer capacitance mechanisms) and crucial solid transducer materials (conducting polymers, carbon and other nanomaterials) and applications in wearable sensors. At the end of the review we illustrate the existing challenges and prospects for future SC-ISEs. We expect this review to provide readers with a general picture of SC-ISEs and appeal to further establishing protocols for evaluating SC-ISEs and accelerating commercial wearable sensors for clinical diagnosis and family practice.
Droplet and Particle Generation on Centrifugal Microfluidic Platforms: A Review
Authors: Azimi-Boulali Javid , Madadelahi Masoud , Madou Marc J. , Martinez-Chapa Sergio O.
Published: June 2020

The use of multiphase flows in microfluidics to carry dispersed phase material (droplets, particles, bubbles, or fibers) has many applications. In this review paper, we focus on such flows on centrifugal microfluidic platforms and present different methods of dispersed phase material generation. These methods are classified into three specific categories, i.e., step emulsification, crossflow, and dispenser nozzle. Previous works on these topics are discussed and related parameters and specifications, including the size, material, production rate, and rotational speed are explicitly mentioned. In addition, the associated theories and important dimensionless numbers are presented. Finally, we discuss the commercialization of these devices and show a comparison to unveil the pros and cons of the different methods so that researchers can select the centrifugal droplet/particle generation method which better suits their needs.
Environment-Sensitive Intelligent Self-Reproducing Artificial Cell with a Modification-Active Lipo-Deoxyribozyme
Authors: Matsuo Muneyuki , Hirata Yuiko , Kurihara Kensuke , Toyota Taro , Miura Toru , Suzuki Kentaro , Sugawara Tadashi
Published: June 2020

As a supramolecular micromachine with information flow, a giant vesicle (GV)-based artificial cell that exhibits a linked proliferation between GV reproduction and internal DNA amplification has been explored in this study. The linked proliferation is controlled by a complex consisting of GV membrane-intruded DNA with acidic amphiphilic catalysts, working overall as a lipo-deoxyribozyme. Here, we investigated how a GV-based artificial cell containing this lipo-deoxyribozyme responds to diverse external and internal environments, changing its proliferative dynamics. We observed morphological changes (phenotypic expression) in GVs induced by the addition of membrane precursors with different intervals of addition (starvation periods). First, we focused on a new phenotype, the “multiple tubulated” form, which emerged after a long starvation period. Compared to other forms, the multiple tubulated form is characterized by a larger membrane surface with a heavily cationic charge. A second consideration is the effect of the chain length of encapsulated DNA on competitive proliferation. The competitive proliferation among three different species of artificial cells containing different lengths of DNA was investigated. The results clearly showed a distinct intervention in the proliferation dynamics of the artificial cells with each other. In this sense, our GV-based artificial cell can be regarded as an intelligent supramolecular machine responding to external and internal environments, providing a new concept for developing molecular machines and robotics.
Genome Analysis of Endobacterium cerealis, a Novel Genus and Species Isolated from Zea mays Roots in North Spain
Authors: Menéndez Esther , Flores-Félix Jose David , Ramírez-Bahena Martha Helena , Igual Jose M. , García-Fraile Paula , Peix Alvaro , Velázquez Encarna
Published: June 2020

In the present work, we analyse the genomic and phenotypic characteristics of a strain named RZME27T isolated from roots of a Zea mays plant grown in Spain. The phylogenetic analyses of 16S rRNA gene and whole genome sequences showed that the strain RZME27T clustered with the type strains of Neorhizobium galegae and Pseudorhizobium pelagicum from the family Rhizobiaceae. This family encompasses several genera establishing symbiosis with legumes, but the genes involved in nodulation and nitrogen fixation are absent in its genome. Nevertheless, genes related to plant colonization, such as those involved in motility, chemotaxis, quorum sensing, exopolysaccharide biosynthesis and hydrolytic enzymes production were found. The comparative pangenomic analyses showed that 78 protein clusters present in the strain RZME27T were not found in the type strains of its closest relatives N. galegae and P. pelagicum. The calculated average nucleotide identity (ANI) values between the strain RZME27T and the type strains of N. galegae and P. pelagicum were 75.61% and 75.1%, respectively, similar or lower than those found for other genera from family Rhizobiaceae. Several phenotypic differences were also found, highlighting the absence of the fatty acid C19:0 cyclo ω8c and propionate assimilation. These results support the definition of a novel genus and species named Endobacterium cerealis gen. nov. sp. nov. whose type strain is RZME27T.
Metagenomic Characterization of Gut Microbiota of Carriers of Extended-Spectrum Beta-Lactamase or Carbapenemase-Producing Enterobacteriaceae Following Treatment with Oral Antibiotics and Fecal Microbiota Transplantation: Results from a Multicenter Randomized Trial
Authors: Leo Stefano , Lazarevic Vladimir , Girard Myriam , Gaïa Nadia , Schrenzel Jacques , de Lastours Victoire , Fantin Bruno , Bonten Marc , Carmeli Yehuda , Rondinaud Emilie , Harbarth Stephan , Huttner Benedikt D.
Published: June 2020

Background: The R-GNOSIS (Resistance in Gram-Negative Organisms: Studying Intervention Strategies) WP3 study was the first multicenter randomized clinical trial systematically investigating fecal microbiota transplantation (FMT) for intestinal decolonization of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) or carbapenemase-producing Enterobacteriaceae (CPE). Here, we characterized the temporal dynamics of fecal microbiota changes in a sub-cohort of the R-GNOSIS WP3 participants before and after antibiotics/FMT using whole metagenome shotgun sequencing. Methods: We sequenced fecal DNA obtained from 16 ESBL-E/CPE carriers having received oral colistin/neomycin followed by FMT and their corresponding seven donors. Ten treatment-naïve controls from the same trial were included. Fecal samples were collected at baseline (V0), after antibiotics but before FMT (V2) and three times after FMT (V3, V4 and V5). Results: Antibiotic treatment transiently decreased species richness and diversity and increased the abundance of antibiotic resistance determinants (ARDs). Bifidobacterium species, together with butyrate- and propionate-producing species from Lachnospiraceae and Ruminococcaceae families were significantly enriched in post-FMT microbiota of treated carriers. After FMT, the proportion of Enterobacteriaceae was lower compared to baseline but without statistical significance. Conclusions: Combined antibiotic and FMT treatment resulted in enrichment of species that are likely to limit the gut colonization by ESBL-E/CPE.
Uncovered Microbial Diversity in Antarctic Cryptoendolithic Communities Sampling Three Representative Locations of the Victoria Land
Authors: Coleine Claudia , Pombubpa Nuttapon , Zucconi Laura , Onofri Silvano , Turchetti Benedetta , Buzzini Pietro , Stajich Jason E. , Selbmann Laura
Published: June 2020

The endolithic niche represents an ultimate refuge to microorganisms in the Mars-like environment of the Antarctic desert. In an era of rapid global change and desertification, the interest in these border ecosystems is increasing due to speculation on how they maintain balance and functionality at the dry limits of life. To assure a reliable estimation of microbial diversity, proper sampling must be planned in order to avoid the necessity of re-sampling as reaching these remote locations is risky and requires tremendous logistical and economical efforts. In this study, we seek to determine the minimum number of samples for uncovering comprehensive bacterial and fungal diversity, comparing communities in strict vicinity to each other. We selected three different locations of the Victoria Land (Continental Antarctica) at different altitudes and showing sandstone outcrops of a diverse nature and origin—Battleship promontory (834 m above sea level (a.s.l.), Southern VL), Trio Nunatak (1,470 m a.s.l., Northern VL) and Mt New Zealand (3,100 m a.s.l., Northern VL). Overall, we found that a wider sampling would be required to capture the whole amplitude of microbial diversity, particularly in Northern VL. We concluded that the inhomogeneity of the rock matrix and the stronger environmental pressure at higher altitudes may force the communities to a higher local diversification.
A Highly Selective Reagent Scheme for Scheelite Flotation: Polyaspartic Acid and Pb–BHA Complexes
Authors: Wei Zhao , Fu Junhao , Han Haisheng , Sun Wei , Yue Tong , Wang Li , Sun Lei
Published: June 2020

Previous studies have proved that the lead complexes of benzohydroxamic acid (Pb–BHA) are effective collectors of scheelite flotations; however, the separation of scheelite from calcite needs depressants with high selectivity. In this study, we reported a novel depressant for calcite minerals, and Pb–BHA served as the collector of scheelite. The flotation behavior of polyaspartic acid (PASP) in a scheelite and calcite flotation that uses Pb–BHA was determined via flotation experiments. Furthermore, the selective adsorption of PASP on the mineral surfaces and the effect of PASP on the adsorption of Pb–BHA on the mineral surfaces were investigated through zeta potential measurements, X-ray photoelectron spectroscopy (XPS), crystal chemistry calculations, and Fourier transform infrared spectroscopy (FTIR) measurements. Thus, PASP demonstrated high selectivity in both scheelite and calcite and contributed to the successful separation of scheelite from calcite. PASP exhibited a higher adsorption capacity and stronger chemisorption with the active sites of calcium atoms on the calcite surface. The crystal chemistry calculations indicated that the distance of the PASP functional groups matched with the calcium distance of a calcite mineral surface, which can be attributed to the selectivity of PASP. Furthermore, the adsorption of PASP impeded the adsorption of Pb–BHA on the calcite surfaces, whereas the opposite was the case for scheelite. The mutually reinforcing selectivity of PASP and Pb–BHA considerably contributes to the efficient flotation separation of scheelite from calcite.
Selected Nanomaterials’ Application Enhanced with the Use of Stem Cells in Acceleration of Alveolar Bone Regeneration during Augmentation Process
Authors: Zakrzewski Wojciech , Dobrzynski Maciej , Rybak Zbigniew , Szymonowicz Maria , Wiglusz Rafal J.
Published: June 2020

Regenerative properties are different in every human tissue. Nowadays, with the increasing popularity of dental implants, bone regenerative procedures called augmentations are sometimes crucial in order to perform a successful dental procedure. Tissue engineering allows for controlled growth of alveolar and periodontal tissues, with use of scaffolds, cells, and signalling molecules. By modulating the patient’s tissues, it can positively influence poor integration and healing, resulting in repeated implant surgeries. Application of nanomaterials and stem cells in tissue regeneration is a newly developing field, with great potential for maxillofacial bony defects. Nanostructured scaffolds provide a closer structural support with natural bone, while stem cells allow bony tissue regeneration in places when a certain volume of bone is crucial to perform a successful implantation. Several types of selected nanomaterials and stem cells were discussed in this study. Their use has a high impact on the efficacy of the current and future procedures, which are still challenging for medicine. There are many factors that can influence the regenerative process, while its general complexity makes the whole process even harder to control. The aim of this study was to evaluate the effectiveness and advantage of both stem cells and nanomaterials in order to better understand their function in regeneration of bone tissue in oral cavity.
Antibacterial Character of Cationic Polymers Attached to Carbon-Based Nanomaterials
Authors: Plachá Daniela , Muñoz-Bonilla Alexandra , Škrlová Kateřina , Echeverria Coro , Chiloeches Alberto , Petr Martin , Lafdi Khalid , Fernández-García Marta
Published: June 2020

The preparation of hybrid polymeric systems based on carbon derivatives with a cationic polymer is described. The polymer used is a copolymer of a quaternizable methacrylic monomer with another dopamine-based monomer capable of anchoring to carbon compounds. Graphene oxide and graphene as well as hybrid polymeric systems were widely characterized by infrared, Raman and photoemission X-ray spectroscopies, electron scanning microscopy, zeta potential and thermal degradation. These allowed confirming the attachment of copolymer onto carbonaceous materials. Besides, the antimicrobial activity of hybrid polymeric systems was tested against Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The results showed the antibacterial character of these hybrid systems.
Role of Synthetic Parameters on the Structural and Optical Properties of N,Sn-Copromoted Nanostructured TiO2: A Combined Ti K-Edge and Sn L2,3-Edges X-ray Absorption Investigation
Authors: Fracchia Martina , Ghigna Paolo , Minguzzi Alessandro , Vertova Alberto , Turco Francesca , Cerrato Giuseppina , Meroni Daniela
Published: June 2020

Sn-modification of TiO2 photocatalysts has been recently proposed as a suitable strategy to improve pollutant degradation as well as hydrogen production. In particular, visible light activity could be promoted by doping with Sn2+ species, which are, however, thermally unstable. Co-promotion with N and Sn has been shown to lead to synergistic effects in terms of visible light activity, but the underlying mechanism has, so far, been poorly understood due to the system complexity. Here, the structural, optical, and electronic properties of N,Sn-copromoted, nanostructured TiO2 from sol-gel synthesis were investigated: the Sn/Ti molar content was varied in the 0–20% range and different post-treatments (calcination and low temperature hydrothermal treatment) were adopted in order to promote the sample crystallinity. Depending on the adopted post-treatment, the optical properties present notable differences, which supports a combined role of Sn dopants and N-induced defects in visible light absorption. X-ray absorption spectroscopy at the Ti K-edge and Sn L2,3-edges shed light onto the electronic properties and structure of both Ti and Sn species, evidencing a marked difference at the Sn L2,3-edges between the samples with 20% and 5% Sn/Ti ratio, showing, in the latter case, the presence of tin in a partially reduced state.
Satellite Cells and Markers of Muscle Regeneration during Unloading and Reloading: Effects of Treatment with Resveratrol and Curcumin
Authors: Mañas-García Laura , Guitart Maria , Duran Xavier , Barreiro Esther
Published: June 2020

We hypothesized that treatment with pharmacological agents known to increase sirtuin-1 activity (resveratrol and curcumin) may enhance muscle regeneration. In limb muscles of mice (C57BL/6J, 10 weeks) exposed to reloading for seven days following a seven-day period of hindlimb immobilization with/without curcumin or resveratrol treatment, progenitor muscle cell numbers (FACS), satellite cell subtypes (histology), early and late muscle regeneration markers, phenotype and morphometry, sirtuin-1 activity and content, and muscle function were assessed. Treatment with either resveratrol or curcumin in immobilized muscles elicited a significant improvement in numbers of progenitor, activated, quiescent, and total counts of muscle satellite cells, compared to non-treated animals. Treatment with either resveratrol or curcumin in reloaded muscles compared to non-treated mice induced a significant improvement in the CSA of both hybrid (curcumin) and fast-twitch fibers (resveratrol), sirtuin-1 activity (curcumin), sirtuin-1 content (resveratrol), and counts of progenitor muscle cells (resveratrol). Treatment with the pharmacological agents resveratrol and curcumin enhanced the numbers of satellite cells (muscle progenitor, quiescent, activated, and total satellite cells) in the unloaded limb muscles but not in the reloaded muscles. These findings have potential clinical implications as treatment with these phenolic compounds would predominantly be indicated during disuse muscle atrophy to enhance the muscle regeneration process.
Development of Criteria for a Positive Front-of-Package Food Labeling: The Israeli Case
Authors: Gillon-Keren Michal , Kaufman-Shriqui Vered , Goldsmith Rebecca , Safra Carmit , Shai Iris , Fayman Gila , Berry Elliot , Tirosh Amir , Dicker Dror , Froy Oren , Gordon Eli , Chavia Ben-Yosef Anat , Nitsan Lesley , Altman Hava , Blaychfeld-Magnazi Moran , Endevelt Ronit
Published: June 2020

Efforts to shape the food environment are aimed at reducing diet-related co-morbidities. Front-of-package labeling (FOPL) may support the consumers to make an informed decision at the point of purchase and encourage industry to reformulate food products. The Israeli Ministry of Health (MOH) implemented a unique FOPL system, using two colors: A mandatory warning (red) label alongside a voluntary positive (green) label. An independent Scientific Committee, from academia, the healthcare system, and MOH was appointed to determine the core principles for the positive FOPL. The criteria were based on the Mediterranean diet principles, with adjustments to the Israeli dietary habits, focusing on the health advantages of the food and considering its processing level. The food products eligible for positive FOPL are foods in their natural form or with added spices or herbs, or those that underwent minimal processing, with no food additives. Based on population consumption data, 19.8% of food products were eligible for positive FOPL; of them, 54% were fruits and vegetables, 20% dairy, and 14% grains. An evaluation plan is needed to assess the degree of acceptance of the positive FOPL by the industry, retailers, and the public, and its impact on food consumption and on public health.
Evaluating Nutrient Intake of Career Firefighters Compared to Military Dietary Reference Intakes
Authors: Johnson Brittany V.B. , Mayer John M.
Published: June 2020

The primary goals of the Dietary Reference Intakes (DRI) are to plan and assess nutrient intakes to promote health, reduce chronic disease, and prevent toxicity. Firefighters have unique nutrient needs compared to the public due to their job demands. The military provides the only published guidance for tactical athletes’ nutrient needs. The purpose of this study was to determine whether firefighters were meeting the Military Dietary Reference Intakes (MDRI). A cross-sectional study was conducted in a sample of career firefighters (n = 150, 37.4 ± 8.4 year-old males) employed in Southern California. Data were gathered during baseline assessments from a Federal Emergency Management Agency-funded Firefighter Wellness Initiative. Participants were asked to log their food and beverage consumption over a 72-h period. Descriptive statistics (means, standard deviations, 95% confidence intervals) were calculated for all participant characteristics and average three-day nutrient intakes. A 95% confidence interval compared their nutrient intake to MDRI to identify differences in nutrient intakes, significance accepted at p = 0.05. Compared to MDRI reference values, firefighters consumed an inadequate amount of total calories, linolenic and alpha-linolenic fatty acid, fiber, vitamins D, E, and K, potassium, magnesium, zinc, and carbohydrates. Vitamin D, magnesium, and potassium had the greatest shortcomings (95.3%, 94.0%, and 98.7%, respectively, under MRDA). Thus, firefighters are not meeting the established MDRI for several key nutrients required to promote health, improve performance, and reduce chronic disease. Dietitians and health care providers may use the results of this study to help design health promotion programs for this population. Future research should develop a customized reference intake for firefighters.
In Silico Design and Validation of OvMANE1, a Chimeric Antigen for Human Onchocerciasis Diagnosis
Authors: Shintouo Cabirou Mounchili , Shey Robert Adamu , Nebangwa Derrick Neba , K. Esoh Kevin , Nongley Nkemngo Francis , Nguve Joel Ebai , Giron Philippe , Mutesa Léon , Vanhamme Luc , Souopgui Jacob , Ghogomu Stephen Mbigha , Njemini Rose
Published: June 2020

The public health goal of onchocerciasis in Africa has advanced from control to elimination. In this light, accurate diagnosis is necessary to determine treatment endpoints and confirm elimination, as well as to conduct surveillance for the identification of any possible recrudescence of the disease. Currently, the monitoring of onchocerciasis elimination relies on the Ov-16 test. However, this test is unable to discriminate between past and active infections. Furthermore, about 15–25% of infected persons are reported to be negative for the Ov-16 test, giving a misleading sense of security to false-negative individuals who might continue to serve as reservoirs for infections. Therefore, we opted to design and validate a more sensitive and specific chimeric antigen (OvMANE1) for onchocerciasis diagnosis, using previously reported immunodominant peptides of O. volvulus, the parasite responsible for the disease. In silico analysis of OvMANE1 predicted it to be more antigenic than its individual peptides. We observed that OvMANE1 reacts specifically and differentially with sera from O. volvulus infected and non-infected individuals, as well as with sera from communities of different levels of endemicity. Moreover, we found that total IgG, unlike IgG4 subclass, positively responded to OvMANE1, strongly suggesting its complementarity to the Ov-16 diagnostic tool, which detects Ov-16 IgG4 antibodies. Overall, OvMANE1 exhibited the potential to be utilized in the development of specific diagnostic tools—based on both antibody capture and antigen capture reactions—which are indispensable to monitor the progress of onchocerciasis elimination programs.
Transmission of Antibiotic Resistant Bacteria and Genes: Unveiling the Jigsaw Pieces of a One Health Problem
Authors: Novais Carla , Freitas Ana R.
Published: June 2020

Antimicrobial Resistance is one of the major Global Health challenges of the twenty-first century, and one of the World Health Organization’s (WHO) top ten global health threats. The evolution of antibiotic resistance among bacterial pathogens requires urgent concerted global efforts under a One Health approach integrating human, animal, and environmental surveillance data. This is crucial to develop efficient control strategies and counteract the spread of multidrug-resistant pathogens. The studies in this Special Issue have evidenced the hidden role of less common species, unusual clones or unexplored niches in the dissemination of antimicrobial resistance between different hosts. They reinforce the need for large-scale surveillance studies tracing and tracking both antibiotic resistance and metal tolerance in different bacterial species.
MLVA-16 Genotyping of Brucella abortus and Brucella melitensis Isolates from Different Animal Species in Egypt: Geographical Relatedness and the Mediterranean Lineage
Authors: Wareth Gamal , El-Diasty Mohamed , Melzer Falk , Schmoock Gernot , Moustafa Shawky A. , El-Beskawy Mohamed , Khater Dali F. , Hamdy Mahmoud E.R. , Zaki Hoda M. , Ferreira Ana Cristina , Ekateriniadou Loukia V. , Boukouvala Evridiki , Abdel-Glil Mostafa Y. , Menshawy Ahmed M.S. , Sancho Marta Pérez , Sakhria Sonia , Pletz Mathias W. , Neubauer Heinrich
Published: June 2020

Brucellosis is a common zoonotic disease in Egypt. However, there are limited data available on the genetic diversity of brucellae circulating in Egypt and other Mediterranean areas. One hundred and nine Brucella (B.) strains were isolated from different animal species in thirteen Egyptian governorates. Multi-locus variable number tandem repeats (VNTRs) analysis (MLVA-16) was employed to determine the geographical relatedness and the genetic diversity of a panel of selected Egyptian strains (n = 69), with strains originating from Italy (n = 49), Portugal (n = 52), Greece (n = 63), and Tunisia (n = 4). Egyptian B. melitensis strains clustered into two main clusters containing 21 genotypes. Egyptian B. abortus strains clustered into three main clusters containing nine genotypes. The genotypes were irregularly distributed over time and space in the study area. Egyptian strains of B. melitensis showed MLVA-16 patterns closer to that of Italian strains. Egyptian B. abortus strains isolated from cattle share the same genotype with strains from Portugal and similar to strains from Italy with low genetic diversity. Strains with similar MLVA patterns isolated from different governorates highlight the movement of the pathogen among governorates. Hence, it may also reflect the long endemicity of brucellosis in Egypt with earlier dispersal of types and great local genetic diversity. Open markets may contribute to cross-species transmission and dissemination of the new types nationwide. The presence of West Mediterranean lineages of B. melitensis and relatedness of B. abortus strains from the studied countries is a result of the socio-historical connections among the Mediterranean countries. Transnational eradication of brucellosis in the Mediterranean basin is highly demanded.