bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Characterization of RF Reactive Sputtered p–Mg-InxGa1−xN/n–Si Hetero-Junction Diodes without Using Buffer Layer
Authors: Tuan Thi Tran Anh , Kuo Dong-Hau , Cao Phuong Thao , Nguyen Van Sau , Pham Quoc-Phong , Nghi Vinh Khanh , Tran Nguyen Phuong Lan
Published: October 2019

The modeling of p–InxGa1−xN/n–Si hetero junction diodes without using the buffer layer were investigated with the “top-top” electrode. The p–Mg-GaN and p–Mg-In0.05Ga0.95N were deposited directly on the n–Si (100) wafer by the RF reactive sputtering at 400 °C with single cermet targets. Al and Pt with the square size of 1 mm2 were used for electrodes of p–InxGa1−xN/n–Si diodes. Both devices had been designed to prove the p-type performance of 10% Mg-doped in GaN and InGaN films. By Hall measurement at the room temperature (RT), the holes concentration and mobility were determined to be Np = 3.45 × 1016 cm−3 and µ = 145 cm2/V·s for p–GaN film, Np = 2.53 × 1017 cm−3, and µ = 45 cm2/V·s for p–InGaN film. By the I–V measurement at RT, the leakage currents at −5 V and turn-on voltages were found to be 9.31 × 10−7 A and 2.4 V for p–GaN/n–Si and 3.38 × 10−6 A and 1.5 V for p–InGaN/n–Si diode. The current densities at the forward bias of 20 V were 0.421 and 0.814 A·cm−2 for p–GaN/n–Si and p–InGaN/n–Si devices. The electrical properties were measured at the temperature range of 25 to 150 °C. By calculating based on the TE mode, Cheungs’ and Norde methods, and other parameters of diodes were also determined and compared.
Crystal Structures of Putative Flavin Dependent Monooxygenase from Alicyclobacillus Acidocaldarius
Authors: Moon Hyunjin , Shin Sungwook , Choe Jungwoo
Published: October 2019

Flavin dependent monooxygenases catalyze various reactions to play a key role in biological processes, such as catabolism, detoxification, and biosynthesis. Group D flavin dependent monooxygenases are enzymes with an Acyl-CoA dehydrogenase (ACAD) fold and use Flavin adenine dinucleotide (FAD) or Flavin mononucleotide (FMN) as a cofactor. In this research, crystal structures of Alicyclobacillus acidocaldarius protein formerly annotated as an ACAD were determined in Apo and FAD bound state. Although our structure showed high structural similarity to other ACADs, close comparison of substrate binding pocket and phylogenetic analysis showed that this protein is more closely related to other bacterial group D flavin dependent monooxygenases, such as DszC (sulfoxidase) and DnmZ and Kijd3 (nitrososynthases).
Design and Optimization of Proton Exchanged Integrated Electro-Optic Modulators in X-Cut Lithium Niobate Thin Film
Authors: Han Huangpu , Xiang Bingxi , Lin Tao , Chai Guangyue , Ruan Shuangchen
Published: October 2019

In this study, we designed, simulated, and optimized proton exchanged integrated Mach-Zehnder modulators in a 0.5-μm-thick x-cut lithium niobate thin film. The single-mode conditions, the mode distributions, and the optical power distribution of the lithium niobate channel waveguides are discussed and compared in this study. The design parameters of the Y-branch and the separation distances between the electrodes were optimized. The relationship between the half-wave voltage length production of the electro-optic modulators and the thickness of the proton exchanged region was studied.
Crystal Structure of IlvC, a Ketol-Acid Reductoisomerase, from Streptococcus Pneumoniae
Authors: Kim Gyuhee , Shin Donghyuk , Lee Sumin , Yun Jaesook , Lee Sangho
Published: October 2019

Biosynthesis of branched-chain amino acids (BCAAs), including isoleucine, leucine and valine, is required for survival and virulence of a bacterial pathogen such as Streptococcus pneumoniae. IlvC, a ketol-acid reductoisomerase (E.C. 1.1.1.86) with NADP(H) and Mg2+ as cofactors from the pathogenic Streptococcus pneumoniae (SpIlvC), catalyzes the second step in the BCAA biosynthetic pathway. To elucidate the structural basis for the IlvC-mediated reaction, we determined the crystal structure of SpIlvC at 1.69 Å resolution. The crystal structure of SpIlvC contains an asymmetric dimer in which one subunit is in apo-form and the other in NADP(H) and Mg2+-bound form. Crystallographic analysis combined with an activity assay and small-angle X-ray scattering suggested that SpIlvC retains dimeric arrangement in solution and that D83 in the NADP(H) binding site and E195 in the Mg2+ binding site are the most critical in the catalytic activity of SpIlvC. Crystal structures of SpIlvC mutants (R49E, D83G, D191G and E195S) revealed local conformational changes only in the NADP(H) binding site. Taken together, our results establish the molecular mechanism for understanding functions of SpIlvC in pneumococcal growth and virulence.
Structural and Electrical Parameters of ZnO Thin Films Grown by ALD with either Water or Ozone as Oxygen Precursors
Authors: Seweryn Aleksandra , Pietruszka Rafal , Witkowski Bartlomiej S. , Wierzbicka Aleksandra , Jakiela Rafal , Sybilski Piotr , Godlewski Marek
Published: October 2019

Low temperature (at 100 °C and below) growth of ZnO thin films by atomic layer deposition (ALD) is demonstrated. Properties of the layers grown with two different oxygen reagents: ozone and water are compared. Diethylzinc (DEZ) was used as metal precursor. Electrical and structural properties of films obtained at several different growth temperatures, ranging from 50 °C to 250 °C were analyzed. It turned out that the film grown in the water-based process at 250 °C and all films grown with ozone have more ordered crystallographic structure with the privileged growth direction (001) perpendicular to the substrate than water-based samples grown in temperatures 100–200 °C. Higher free electron concentration at room temperature was observed for ozone-based samples grown at 100 °C and 150 °C in comparison to water-based samples obtained at the same growth temperature. Low value of resistivity in case of ozone-based samples grown at 100 °C is a promising result, however lower electron mobility requires further optimization.
Previous, Current, and Future Pharmacotherapy and Diagnosis of Prostate Cancer—A Comprehensive Review
Authors: Malinowski Bartosz , Wiciński Michał , Musiała Nikola , Osowska Ilona , Szostak Mateusz
Published: October 2019

Prostate cancer (PCa) is one of the most common cancers in men that usually develops slowly. Since diagnostic methods improved in the last decade and are highly precise, more cancers are diagnosed at an early stage. Active surveillance or watchful waiting are appealing approaches for men diagnosed with low-risk prostate cancer, and they are an antidote to the overtreatment problem and unnecessary biopsies. However, treatment depends on individual circumstances of a patient. Older hormonal therapies based on first generation antiandrogens and steroids were widely used in metastatic castration-resistant prostate cancer (mCRPC) patients prior to the implementation of docetaxel. Nowadays, accordingly to randomized clinical trials, abiraterone, enzalutamide, apalutamide. and docetaxel became first line agents administrated in the treatment of mCRPC. Furthermore, radium-223 is an optional therapy for bone-only metastasis patients. Sipuleucel-T demonstrated an overall survival benefit. However, other novel immunotherapeutics showed limitations in monotherapy. Possible combinations of new vaccines or immune checkpoint blockers with enzalutamide, abiraterone, radium-223, or docetaxel are the subject of ongoing rivalry regarding optimal therapy of prostate cancer.
Hardware Optimized and Error Reduced Approximate Adder
Authors: Balasubramanian Padmanabhan , Maskell Douglas L.
Published: October 2019

This paper presents a new hardware optimized and error reduced approximate adder (HOERAA), which is suitable for field programmable gate array (FPGA)- and application specific integrated circuit (ASIC)-based implementations. In this work, we consider a FPGA-based implementation using Xilinx Vivado 2018.3, targeting an Artix-7 FPGA. The ASIC-based realizations are based on a 32/28nm complementary metal oxide semiconductor (CMOS) process. Based on FPGA implementations, we note the following: (i) For 32-bit addition involving a 8-bit least significant inaccurate sub-adder, HOERAA requires 22% fewer look-up tables (LUTs) and 18.6% fewer registers while reducing the minimum clock period by 7.1% and reducing the power-delay product (PDP) by 14.7%, compared to the native accurate FPGA adder, and (ii) for 64-bit addition involving a 8-bit least significant inaccurate sub-adder, HOERAA requires 11% fewer LUTs and 9.3% fewer registers while reducing the minimum clock period by 8.3% and reducing the PDP by 9.3%, compared to the native accurate FPGA adder. Based on ASIC-style implementations, HOERAA is found to achieve the following reductions in design metrics compared to an optimum accurate carry-lookahead adder: (i) A 15.7% reduction in critical path delay, a 21.4% reduction in area, and a 35% reduction in PDP for 32-bit addition involving a 8-bit least significant inaccurate sub-adder, and (ii) a 15.3% reduction in critical path delay, a 10.7% reduction in area, and a 20% reduction in PDP for 64-bit addition involving a 8-bit least significant inaccurate sub-adder. Moreover, comparisons with other approximate adders show that HOERAA has a significantly reduced average error, mean average error, and root mean square error, while reporting near optimum design metrics.
Refocusing of Multiple Moving Targets Based on the Joint Sparse Processing of One Channel Synthetic Aperture Radar Imagery Patches
Authors: Wang Xin , Qiao Ling
Published: October 2019

A sparse-based refocusing methodology for multiple slow-moving targets (MTs) located inside strong clutter regions is proposed in this paper. The defocused regions of MTs in synthetic aperture radar (SAR) imagery were utilized here instead of the whole original radar data. A joint radar projection operator for the static and moving objects was formulated and employed to construct an optimization problem. The Lp norm constraint was utilized to promote the separation of MT data and the suppression of clutter. After the joint sparse imaging processing, the energy of strong static targets could be suppressed significantly in the reconstructed MT imagery. The static scene imagery could be derived simultaneously without the defocused MT. Finally, numerical simulations were used verify the validity and robustness of the proposed methodology.
New “Full-Bridge Buck Inverter–DC Motor” System: Steady-State and Dynamic Analysis and Experimental Validation
Authors: Hernández-Márquez Eduardo , Avila-Rea Carlos Alejandro , García-Sánchez José Rafael , Silva-Ortigoza Ramón , Marciano-Melchor Magdalena , Marcelino-Aranda Mariana , Roldán-Caballero Alfredo , Márquez-Sánchez Celso
Published: October 2019

A mathematical model of a new “full-bridge Buck inverter–DC motor” system is developed and experimentally validated. First, using circuit theory and the mathematical model of a DC motor, the dynamic behavior of the system under study is deduced. Later, the steady-state, stability, controllability, and flatness properties of the deduced model are described. The flatness property, associated with the mathematical model, is then exploited so that all system variables and the input can be differentially parameterized in terms of the flat output, which is determined by the angular velocity. Then, when a desired trajectory is proposed for the flat output, the input signal is calculated offline and is introduced into the system. In consequence, the validation of the mathematical model for constant and time-varying duty cycles is possible. Such a validation of this mathematical model is tackled from two directions: (1) by circuit simulation through the SimPowerSystems toolbox of Matlab-Simulink and (2) via a prototype of the system built by using Matlab-Simulink and a DS1104 board. The good similarities between the circuit simulation and the experimental results allow satisfactorily validating the mathematical model.
Characterization and Correction of the Geometric Errors Using a Confocal Microscope for Extended Topography Measurement, Part II: Experimental Study and Uncertainty Evaluation
Authors: Wang Chen , Gómez Emilio , Yu Yingjie
Published: October 2019

This paper presents the experimental implementations of the mathematical models and algorithms developed in Part I. Two experiments are carried out. The first experiment determines the correction coefficients of the mathematical model. The dot grid target is measured, and the measurement data are processed by our developed and validated algorithms introduced in Part I. The values of the coefficients are indicated and analyzed. Uncertainties are evaluated using the Monte Carlo method. The second experiment measures a different area of the dot grid target. The measurement results are corrected according to the coefficients determined in the first experiment. The mean residual between the measured points and their corresponding certified values reduced 29.6% after the correction. The sum of squared errors reduced 47.7%. The methods and the algorithms for raw data processing, such as data partition, fittings of dots’ centers, K-means clustering, etc., are the same for the two experiments. The experimental results demonstrate that our method for the correction of the errors produced by the movement of the lateral stage of a confocal microscope is meaningful and practicable.
An Efficient Encryption Algorithm for the Security of Sensitive Private Information in Cyber-Physical Systems
Authors: Zhu Xiaogang , Srivastava Gautam , M. Parizi Reza
Published: October 2019

The new developments in smart cyber-physical systems can be shown to include smart cities, Internet of things (IoT), and for the most part smart anything. To improve the security of sensitive personal information (SPI) in cyber-physical systems, we present some novel ideas related to the encryption of SPI. Currently, there are issues in traditional encryption methods, such as low speed of information acquisition, low recognition rate, low utilization rate of effective information resources, and high delay of information query. To address these issues, we propose a novel efficient encryption algorithm for the security of incremental SPI. First, our proposed method analyzes user information resources and determines valid data to be encrypted. Next, it uses adaptive acquisition methods to collect information, and uses our encryption method to complete secure encryption of SPI according to the acquisition results. Our experimental analysis clearly shows that the algorithm effectively improves the speed of information acquisition as well as effective information recognition rate, thus enhancing the security of SPI. The encryption model in turn can provide a strong guarantee for user information security.
Development and Deployment of Green Technologies for Sustainable Environment
Authors: Pan Shu-Yuan , Fan Chihhao , Lin Yu-Pin
Published: October 2019

The definition of green technologies should be any process, product or service that reduces negative environmental impacts while protecting human health and ecosystem quality [...]
The Challenges of the Forestry Sector Communication Based on an Analysis of Research Studies in the Czech Republic
Authors: Riedl Marcel , Jarský Vilém , Palátová Petra , Sloup Roman
Published: October 2019

Achieving public support and understanding in addressing the challenges of climate change and the bark beetle calamity is a prerequisite for the successful future of Czech forestry. The most important instrument for achieving public support is communication. To be effective, this communication has to be built on a communication strategy reflecting the long-term goals of forest policy and has to be based on both current analyses and other relevant information, which, in turn, is based on the research results of the public perception of the forests and forestry. This article deals with the results of current research studies and formulates conclusions in relation to this communication strategy. Among other things, these results indicate the willingness of a large part of the public to actively participate in voluntary assistance to forestry, markedly differing opinions among individual groups on forest functions, and rather below-average interest in information concerning forests and forestry.
Winter Embolism and Recovery in the Conifer Shrub Pinus mugo L.
Authors: Mayr Stefan , Schmid Peter , Rosner Sabine
Published: October 2019

Research Highlights: Pronounced winter embolism and recovery were observed in the Alpine conifer shrub Pinus mugo L. Data indicated that the hydraulic courses and underlying mechanism were similar to timberline trees. Background and Objectives: At high elevation, plants above the snow cover are exposed to frost drought and temperature stress during winter. Previous studies demonstrated winter stress to induce low water potentials (Ψ) and significant xylem embolism (loss of conductivity, or LC) in evergreen conifer trees, and recovery from embolism in late winter. Here, we analyzed xylem hydraulics and related structural and cellular changes in a conifer shrub species. Materials and Methods: The uppermost branches of Pinus mugo shrubs growing at the Alpine timberline were harvested over one year, and the Ψ, water content, LC, proportion of aspirated pits, and carbohydrate contents were analyzed. Results: Minimum Ψ (−1.82 ± 0.04 MPa) and maximum LC (39.9% ± 14.5%) values were observed in mid and late winter, followed by a recovery phase. The proportion of aspirated pits was also highest in winter (64.7% ± 6.9% in earlywood, 27.0% ± 1.4% in latewood), and decreased in parallel with hydraulic recovery in late winter and spring. Glucose and fructose contents gradually decreased over the year, while starch contents (also microscopically visible as starch grains in needle and stem tissues) increased from May to July. Conclusions: The formation and recovery of embolism in Pinus mugo were similar to those of timberline trees, as were the underlying mechanisms, with pit aspiration enabling the isolation of embolized tracheids, and changes in carbohydrate contents indicating adjustments of osmotic driving forces for water re-distribution. The effects of future changes in snow cover regimes may have pronounced and complex effects on shrub-like growth forms, because a reduced snow cover may shorten the duration of frost drought, but expose the plants to increased temperature stress and impair recovery processes.
Forest Understorey Vegetation: Colonization and the Availability and Heterogeneity of Resources
Authors: Su Xiangping , Wang Minhuang , Huang Zhiqun , Fu Songling , Chen Han Y.H.
Published: October 2019

Understorey vegetation comprises a major portion of plant diversity and contributes greatly to nutrient cycling and energy flow. This review examines the mechanisms involved in the response of understorey vegetation to stand development and the overstorey canopy following disturbances. The overall abundance and diversity of the understorey is enhanced with the availability and heterogeneity of light, soil nutrients, soil moisture, and substrates. Vascular plants are positively impacted by the availability and heterogeneity of light and soil nutrients, whereas non-vascular vegetation is more strongly influenced by colonization time, soil moisture, and substrates, and is decreased with a higher proportion of broadleaf overstorey. The availability of resources is a prominent driver toward the abundance and diversity of understorey vegetation, from the stand initiation to stem exclusion stage under a single-species dominated overstorey. However, resource heterogeneity dominates at the later stages of succession under a mixed overstorey. Climate and site conditions modify resource availability and heterogeneity in the understorey layer, but the extent of their influences requires more investigation. Forest management practices (clearcutting and partial harvesting) tend to increase light availability and heterogeneity, which facilitates the abundance and diversity of understorey vascular plants; however, these factors reduce the occurrence of non-vascular plants. Nevertheless, in the landscape context, anthropogenic disturbances homogenize environmental conditions and reduce beta-diversity, as well, the long-term effects of anthropogenic disturbances on understorey vegetation remain unclear, particularly compared with those in primary forests.
Understanding the Critical Impact Path on Vegetation Growth under Climate Extremes and Human Influence
Authors: Kim Yoon Jung , Song Young Keun , Lee Dong Kun
Published: October 2019

Reduced vegetation growth ultimately induces degradation of the ecosystem and CO2 sequestration. Multiple risks can affect vegetation, but climate change and human influence have been particularly known to be major risks for deteriorating the ecosystem. However, there is limited information illustrating comprehensive impact pathways that consider both climatic and human impacts on vegetation. To promote optimum decision-making, information is required to elucidate complex cause-and-effect pathways in order to determine how various impacts are related and which ones are more important. Hence, we identified impact pathways affecting enhanced vegetation index (EVI) regarding climate and human factors by revealing a causal network using the Bayesian network approach. Vulnerable vegetation types and the spatial range of impact were evaluated based on the identified network by analyzing temporal changes in annual average EVI, human-induced land conversion, and multiple climate extremes from 2002 to 2014 on Jeju Island, South Korea. The results indicated the high vulnerability of coniferous forests compared with mixed and deciduous forests were able to elucidate the major impact paths, including human-induced land conversion at lower elevation, length of frost, degree of heat, and general intensity of wetness (Pearson’s r = 0.58). Existing policies in the study site have been insufficient to avoid the major paths influencing vegetation state. This study offers insights into comprehensive impact paths in order to support effective decision-making for nature conservation.
Seven Decades of Spontaneous Forest Regeneration after Large-Scale Clear-Cutting in Białowieża Forest do not Ensure the Complete Recovery of Collembolan Assemblages
Authors: Sławski Marek , Sławska Małgorzata
Published: October 2019

The long-term effects of large-scale disturbance on forest ecosystem processes and structure are poorly understood. To assess the effects of large-scale clear-cutting on the taxonomic and functional structure of collembolan assemblages, 18 plots were established in the Polish part of Białowieża Forest. All plots, situated in a mixed Tilio-Carpinetum broad-leaved forest, had eutrophic Cambisol developed on rich glacial deposits. The Collembola assemblages in the stands that had naturally regenerated on large-scale clear-cuts performed at the beginning of the 20th century were compared to those in old-growth forests (i.e., the endpoint of stand development following stand-replacing disturbance). Collembolans, one of the most numerous soil microarthropods, are successfully used to assess the consequences of forest management and ecosystem restoration. Our study tested whether seven decades of spontaneous forest development after large-scale anthropogenic disturbance ensures the complete recovery of the soil Collembola. Using complementary taxonomic and life-form approaches, we provide evidence that the collembolan assemblages associated with the tree stands that had spontaneously developed in large harvesting plots distinctly differed from those in old-growth deciduous forests in this region despite seven decades of regenerative forest succession. The species diversity of the assemblages in the naturally regenerated tree stands was significantly lower, and their life-form structure was noticeably different from those in the reference forests. Moreover, the shift in the functional group structure of the collembolan assemblages in the stands that had regenerated after clear-cutting indicates that their activity seven decades after disturbance is concentrated mainly on the decomposition of the litter in the upper layers, whereas the processes controlled by these organisms in the deeper soil layers are not fully restored.
Fog Computing in IoT Smart Environments via Named Data Networking: A Study on Service Orchestration Mechanisms
Authors: Amadeo Marica , Ruggeri Giuseppe , Campolo Claudia , Molinaro Antonella , Loscrí Valeria , Calafate Carlos T.
Published: October 2019

By offering low-latency and context-aware services, fog computing will have a peculiar role in the deployment of Internet of Things (IoT) applications for smart environments. Unlike the conventional remote cloud, for which consolidated architectures and deployment options exist, many design and implementation aspects remain open when considering the latest fog computing paradigm. In this paper, we focus on the problems of dynamically discovering the processing and storage resources distributed among fog nodes and, accordingly, orchestrating them for the provisioning of IoT services for smart environments. In particular, we show how these functionalities can be effectively supported by the revolutionary Named Data Networking (NDN) paradigm. Originally conceived to support named content delivery, NDN can be extended to request and provide named computation services, with NDN nodes acting as both content routers and in-network service executors. To substantiate our analysis, we present an NDN fog computing framework with focus on a smart campus scenario, where the execution of IoT services is dynamically orchestrated and performed by NDN nodes in a distributed fashion. A simulation campaign in ndnSIM, the reference network simulator of the NDN research community, is also presented to assess the performance of our proposal against state-of-the-art solutions. Results confirm the superiority of the proposal in terms of service provisioning time, paid at the expenses of a slightly higher amount of traffic exchanged among fog nodes.
Impacts of Video Display on Purchase Intention for Digital and Home Appliance Products—Empirical Study from China
Authors: Hao Ruohong , Shao Bingjia , Ma Rong
Published: October 2019

Rapid online trading expansion and the bloom of internet technologies has raised the importance of effective product video presentations for online retailers. This article developed a model for the impacts of video presentations on purchase intention for digital and home appliance products. Four group experiments were designed, and empirical tests were performed. This research found that presenting videos on how to use digital and home appliance products increased purchase intention by raising the information gained by customers. Meanwhile, video tutorial information had insignificant effects related to the knowledge and experience of customers.
Effects of Hybridisation on the Low Velocity Falling Weight Impact and Flexural Properties of Flax-Carbon/Epoxy Hybrid Composites
Authors: Chapman Matthew , Dhakal Hom Nath
Published: October 2019

The trend of research and adoption of natural plant-based fibre reinforced composites is increasing, with traditional synthetic fibres such as carbon and glass experiencing restrictions placed on their manufacture and use by legislative bodies due to their environmental impact through the entire product life cycle. Finding suitable alternatives to lightweight and high-performance synthetic composites will be of benefit to the automotive, marine and aerospace industries. This paper investigates the low-velocity impact (LVI) and flexural properties and damage characteristics of flax-carbon/epoxy hybrid composites to be used in structural lightweight applications. LVI, for example, is analogous to several real-life situations, such as damage during manufacture, feasibly due to human error such as the dropping of tools and mishandling of the finished product, debris strikes of aircraft flight, or even the collision of a vessel with another. Carbon fibre has been hybridised with flax fibres to achieve enhanced impact and flexural performance. The failure mechanisms of woven flax and flax-carbon epoxy hybrid composites have been further analysed using Scanning Electron Microscopy (SEM). It was observed from the experimental results that carbon fibre hybridisation has a significant effect on the impact and flexural properties and their damage modes. The results obtained from this study exhibited that the flexural strength and modulus of plain flax/epoxy composite increase significantly from 95.66 MPa to 425.87 MPa and 4.78 GPa to 17.90 GPa, respectively, with carbon fibre hybridisation. This significant improvement in flexural properties would provide designers with important information to make informed decisions during material selection for lightweight structural applications.
Environmental Conditions May Shape the Patterns of Genomic Variations in Leishmania panamensis
Authors: Restrepo Carlos M. , Llanes Alejandro , Cedeño Eymi M. , Chang Jim H. , Álvarez Jennifer , Ríos Margarita , Penagos Homero , Suárez José A. , Lleonart Ricardo
Published: October 2019

Due to the absence of transcriptional regulation of gene expression in Leishmania parasites, it is now well accepted that several forms of genomic variations modulate the levels of critical proteins through changes in gene dosage. We previously observed many of these variations in our reference laboratory strain of L. panamensis (PSC-1 strain), including chromosomes with an increased somy and the presence of a putative linear minichromosome derived from chromosome 34. Here, we compared the previously described genomic variations with those occurring after exposure of this strain to increasing concentrations of trivalent antimony (SbIII), as well as those present in two geographically unrelated clinical isolates of L. panamensis. We observed changes in the somy of several chromosomes, amplifications of several chromosomal regions, and copy number variations in gene arrays after exposure to SbIII. Occurrence of amplifications potentially beneficial for the Sb-resistant phenotype appears to be associated with the loss of other forms of amplification, such as the linear minichromosome. In contrast, we found no evidence of changes in somy or amplification of relatively large chromosomal regions in the clinical isolates. In these isolates, the predominant amplifications appear to be those that generate genes arrays; however, in many cases, the amplified arrays have a notably higher number of copies than those from the untreated and Sb-treated laboratory samples.
Diversity Analysis of Sweet Potato Genetic Resources Using Morphological and Qualitative Traits and Molecular Markers
Authors: Palumbo Fabio , Galvao Aline Carolina , Nicoletto Carlo , Sambo Paolo , Barcaccia Gianni
Published: October 2019

The European Union (EU) market for sweet potatoes has increased by 100% over the last five years, and sweet potato cultivation in southern European countries is a new opportunity for the EU to exploit and introduce new genotypes. In view of this demand, the origins of the principal Italian sweet potato clones, compared with a core collection of genotypes from Central and Southern America, were investigated for the first time. This was accomplished by combining a genetic analysis, exploiting 14 hypervariable microsatellite markers, with morphological and chemical measurements based on 16 parameters. From the molecular analyses, Italian accessions were determined to be genetically very similar to the South American germplasm, but they were sub-clustered into two groups. This finding was subsequently confirmed by the morphological and chemical measurements. Moreover, the analysis of the genetic structure of the population suggested that one of the two groups of Italian genotypes may have descended from one of the South American accessions, as predicted on the basis of the shared morphological characteristics and molecular fingerprints. Overall, the combination of two different characterization methods, genetic markers and agronomic traits, was effective in differentiating or clustering the sweet potato genotypes, in agreement with their geographical origin or phenotypic descriptors. This information could be exploited by both breeders and farmers to detect and protect commercial varieties, and hence for traceability purposes.
Clinical and Molecular Characterization of Classical-Like Ehlers-Danlos Syndrome Due to a Novel TNXB Variant
Authors: Rymen Daisy , Ritelli Marco , Zoppi Nicoletta , Cinquina Valeria , Giunta Cecilia , Rohrbach Marianne , Colombi Marina
Published: October 2019

The Ehlers-Danlos syndromes (EDS) constitute a clinically and genetically heterogeneous group of connective tissue disorders. Tenascin X (TNX) deficiency is a rare type of EDS, defined as classical-like EDS (clEDS), since it phenotypically resembles the classical form of EDS, though lacking atrophic scarring. Although most patients display a well-defined phenotype, the diagnosis of TNX-deficiency is often delayed or overlooked. Here, we described an additional patient with clEDS due to a homozygous null-mutation in the TNXB gene. A review of the literature was performed, summarizing the most important and distinctive clinical signs of this disorder. Characterization of the cellular phenotype demonstrated a distinct organization of the extracellular matrix (ECM), whereby clEDS distinguishes itself from most other EDS subtypes by normal deposition of fibronectin in the ECM and a normal organization of the α5β1 integrin.
The Value of Reference Genomes in the Conservation of Threatened Species
Authors: Brandies Parice , Peel Emma , Hogg Carolyn J. , Belov Katherine
Published: October 2019

Conservation initiatives are now more crucial than ever—over a million plant and animal species are at risk of extinction over the coming decades. The genetic management of threatened species held in insurance programs is recommended; however, few are taking advantage of the full range of genomic technologies available today. Less than 1% of the 13505 species currently listed as threated by the International Union for Conservation of Nature (IUCN) have a published genome. While there has been much discussion in the literature about the importance of genomics for conservation, there are limited examples of how having a reference genome has changed conservation management practice. The Tasmanian devil (Sarcophilus harrisii), is an endangered Australian marsupial, threatened by an infectious clonal cancer devil facial tumor disease (DFTD). Populations have declined by 80% since the disease was first recorded in 1996. A reference genome for this species was published in 2012 and has been crucial for understanding DFTD and the management of the species in the wild. Here we use the Tasmanian devil as an example of how a reference genome has influenced management actions in the conservation of a species.
Levels of Knowledge, Beliefs, and Practices Regarding Osteoporosis and the Associations with Bone Mineral Density among Populations More Than 40 Years Old in Malaysia
Authors: Chan Chin Yi , Subramaniam Shaanthana , Chin Kok-Yong , Ima-Nirwana Soelaiman , Muhammad Norliza , Fairus Ahmad , Ng Pei Yuen , Jamil Nor Aini , Abd Aziz Noorazah , Mohamed Norazlina
Published: October 2019

Osteoporosis is a skeletal disorder commonly found among the elderly, in which the bones become weak, brittle, and more susceptible to fracture. Adequate knowledge and positive attitude towards the disease and osteoprotective activities may prevent osteoporosis, but comprehensive studies to verify this hypothesis are limited in Malaysia. This study aims to bridge the research gap by determining the levels of knowledge, beliefs, and practices regarding osteoporosis and their associations with bone mineral density (BMD) among men and women ≥ 40 years in Klang Valley, Malaysia. In this cross-sectional study, 786 Malaysians (382 men, 404 women) completed a questionnaire on knowledge, beliefs, and osteoprotective practices, and underwent BMD scan using a dual-energy X-ray absorptiometry device. The current study found moderate levels of knowledge and beliefs regarding osteoporosis but poor osteoprotective practices. Osteoporosis knowledge, beliefs, and practices were significantly different based on subjects’ demographic characteristics (p < 0.05). Osteoporosis knowledge and beliefs were correlated significantly with osteoprotective practices (p < 0.05). Bone health status of the subjects was associated positively with calcium supplement intake, and negatively with exercise barriers and smoking status of the subjects (p < 0.05). However, no significant correlation was noted between osteoporosis knowledge and bone health (p > 0.05). Conclusively, despite some correlations between individual components, the detachment between bone health knowledge and beliefs, and osteoprotective practices among Malaysians is apparent. Integrating all three components into a comprehensive osteoporosis prevention program is warranted.
Factors Associated with Physical Fitness among Overweight and Non-Overweight Austrian Secondary School Students
Authors: Ruedl Gerhard , Greier Nikolaus , Niedermeier Martin , Posch Markus , Prünster Vera , Faulhaber Martin , Burtscher Martin
Published: October 2019

The aim of the study was to evaluate factors associated with physical fitness (PF) among overweight and non-overweight Austrian secondary school students. PF was measured using the German motor test (DMT) 6–18 and students were asked about sex, migration background, weekly leisure time physical activity and daily electronic media use. In total 560 adolescents (56.6% female) with a mean age of 15.4 ± 1.4 years and a mean body mass index (BMI) of 22.5 ± 4.2 kg/m² were evaluated with 130 (23.2%) students classified as overweight or obese. For the total cohort, results of the multiple linear regression analysis (R2 = 0.34) revealed that a younger age (β = −0.16), no migration background (β = 0.13), a lower BMI (β = −0.29), a higher weekly leisure time physical activity (β = 0.34) and a lower daily electronic media use (β = −0.15) were associated with increased PF. Separate regression analyses for non-overweight and overweight students showed similar regression coefficients except for BMI. In conclusion, the positive influence of modifiable factors such as lower BMI, higher self-reported weekly leisure time sports activity and lower self-reported daily electronic media use should be considered already at young ages to increase physical fitness in overweight and non-overweight youth.
Impact of a Vicinity of Airport on the Prices of Single-Family Houses with the Use of Geospatial Analysis
Authors: Cellmer Radosław , Bełej Mirosław , Konowalczuk Jan
Published: October 2019

This article analyses the adverse impact of Chopin Airport in Warsaw on the prices of single-family houses located within the aircraft noise impact zone. The specific feature of the largest airport in Poland is its location within the city limits and the resulting direct surroundings of both multi- and single-family housing developments. Not only is the nuisance due to the proximity of the airport resulting from the actual exposure to an excessive noise level but also from legal restrictions associated with the Limited Use Area (LUA). The study used statistical modeling by applying a classic multiple regression model, spatial autoregressive model and geographically weighted regression model. Moreover, Geographical Information System (GIS) tools and geostatic modeling were used to visualise the results. The modeling results clearly show the significant impact of the neighborhood nuisance and the related spatial distribution of real estate prices. In addition, the geographically weighted regression model indicates that the proximity to an airport adversely affects the rate of price changes over time.
Estimation of Origin-Destination Flows of Passenger Cars in 1925 in Old Tokyo City, Japan
Authors: Ishikawa Kazuki , Nakayama Daichi
Published: October 2019

In recent years, surveys of personal travel behavior have been conducted around the world and these surveys have been used for understanding the characteristics of people flow. However, it is impossible to acquire people and traffic flows for the modern era (1868–1945). In modern era Japan, some traffic surveys were conducted, and that records still persist. The purpose of this study was to estimate origin-destination (OD) flows in old Tokyo in 1925 based on the historical traffic census record. In this study, OD flows were estimated using an absorbing Markov chain model, which is a simple model based on traffic generation and transition probabilities. Transition probabilities in unobserved nodes were estimated using genetic algorithms (GA). The result of OD distributions is clearly different in the eastern part of Tokyo City, the Shitamachi area, from the western part, the Yamanote area. The traffic was very busy in Shitamachi, an area which included terminal stations and a central business district. In Yamanote, major traffic generation and absorption points were distributed along the main streets to the Shinjuku or Shibuya areas. These results are affected by the distribution of main roads and the locations of residences or workplaces of car owners.
Disulfide Engineered Lipase to Enhance the Catalytic Activity: A Structure-Based Approach on BTL2
Authors: Godoy César A. , Klett Javier , Di Geronimo Bruno , Hermoso Juan A. , Guisán José M. , Carrasco-López César
Published: October 2019

Enhancement, control, and tuning of hydrolytic activity and specificity of lipases are major goals for the industry. Thermoalkaliphilic lipases from the I.5 family, with their native advantages such as high thermostability and tolerance to alkaline pHs, are a target for biotechnological applications. Although several strategies have been applied to increase lipases activity, the enhancement through protein engineering without compromising other capabilities is still elusive. Lipases from the I.5 family suffer a unique and delicate double lid restructuration to transition from a closed and inactive state to their open and enzymatically active conformation. In order to increase the activity of the wild type Geobacillus thermocatenulatus lipase 2 (BTL2) we rationally designed, based on its tridimensional structure, a mutant (ccBTL2) capable of forming a disulfide bond to lock the open state. ccBTL2 was generated replacing A191 and F206 to cysteine residues while both wild type C64 and C295 were mutated to serine. A covalently immobilized ccBTL2 showed a 3.5-fold increment in esterase activity with 0.1% Triton X-100 (2336 IU mg−1) and up to 6.0-fold higher with 0.01% CTAB (778 IU mg−1), both in the presence of oxidizing sulfhydryl agents, when compared to BTL2. The remarkable and industrially desired features of BTL2 such as optimal alkaliphilic pH and high thermal stability were not affected. The designed disulfide bond also conferred reversibility to the enhancement, as the increment on activity observed for ccBTL2 was controlled by redox pretreatments. MD simulations suggested that the most stable conformation for ccBTL2 (with the disulfide bond formed) was, as we predicted, similar to the open and active conformation of this lipase.
Identification of Gain and Loss of Function Missense Variants in MRGPRX2’s Transmembrane and Intracellular Domains for Mast Cell Activation by Substance P
Authors: Chompunud Na Ayudhya Chalatip , Roy Saptarshi , Alkanfari Ibrahim , Ganguly Anirban , Ali Hydar
Published: October 2019

The neuropeptide substance P (SP) contributes to neurogenic inflammation through the activation of human mast cells via Mas-related G protein-coupled receptor-X2 (MRGPRX2). Using pertussis toxins and YM-254890, we demonstrated that SP induces Ca2+ mobilization and degranulation via both the Gαi and Gαq family of G proteins in rat basophilic leukemia (RBL-2H3) cells stably expressing MRGPRX2. To determine the roles of MRGPRX2’s transmembrane (TM) and intracellular domains on SP-induced responses, we utilized information obtained from both structural modeling and naturally occurring MRGPRX2 missense variants. We found that highly conserved residues in TM6 (I225) and TM7 (Y279) of MRGPRX2 are essential for SP-induced Ca2+ mobilization and degranulation in transiently transfected RBL-2H3 cells. Cells expressing missense variants in the receptor’s conserved residues (V123F and V282M) as well as intracellular loops (R138C and R141C) failed to respond to SP. By contrast, replacement of all five Ser/Thr residues with Ala and missense variants (S325L and L329Q) in MRGPRX2’s carboxyl-terminus resulted in enhanced mast cell activation by SP when compared to the wild-type receptor. These findings suggest that MRGPRX2 utilizes conserved residues in its TM domains and intracellular loops for coupling to G proteins and likely undergoes desensitization via phosphorylation at Ser/Thr residues in its carboxyl-terminus. Furthermore, identification of gain and loss of function MRGPRX2 variants has important clinical implications for SP-mediated neurogenic inflammation and other chronic inflammatory diseases.
Expression of Two α-Type Expansins from Ammopiptanthus nanus in Arabidopsis thaliana Enhance Tolerance to Cold and Drought Stresses
Authors: Liu Yanping , Zhang Li , Hao Wenfang , Zhang Ling , Liu Yi , Chen Longqing
Published: October 2019

Expansins, cell-wall loosening proteins, play an important role in plant growth and development and abiotic stress tolerance. Ammopiptanthus nanus (A. nanus) is an important plant to study to understand stress resistance in forestry. In our previous study, two α-type expansins from A. nanus were cloned and named AnEXPA1 and AnEXPA2. In this study, we found that they responded to different abiotic stress and hormone signals. It suggests that they may play different roles in response to abiotic stress. Their promoters show some of the same element responses to abiotic stress and hormones, but some special elements were identified between the expansins that could be essential for their expression. In order to further testify the reliability of the above results, we conducted an analysis of β-glucuronidase (GUS) dyeing. The analysis showed that AnEXPA1 was only induced by cold stress, whereas AnEXPA2 responded to hormone induction. AnEXPA1 and AnEXPA2 transgenic Arabidopsis plants showed better tolerance to cold and drought stresses. Moreover, the ability to scavenge reactive oxygen species (ROS) was significantly improved in the transgenic plants, and expansin activity was enhanced. These results suggested that AnEXPA1 and AnEXPA2 play an important role in the response to abiotic stress. Our research contributes to a better understanding of the regulatory network of expansins and may benefit agricultural production.