bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian Update with Information Quality under the Framework of Evidence Theory
Authors: Li Yuting , Xiao Fuyuan
Published: December 2018

Bayesian update is widely used in data fusion. However, the information quality is not taken into consideration in classical Bayesian update method. In this paper, a new Bayesian update with information quality under the framework of evidence theory is proposed. First, the discounting coefficient is determined by information quality. Second, the prior probability distribution is discounted as basic probability assignment. Third, the basic probability assignments from different sources can be combined with Dempster’s combination rule to obtain the fusion result. Finally, with the aid of pignistic probability transformation, the combination result is converted to posterior probability distribution. A numerical example and a real application in target recognition show the efficiency of the proposed method. The proposed method can be seen as the generalized Bayesian update. If the information quality is not considered, the proposed method degenerates to the classical Bayesian update.
A Controlled-Environment Quality Assessment of Android GNSS Raw Measurements
Authors: Gogoi Neil , Minetto Alex , Linty Nicola , Dovis Fabio
Published: December 2018

Raw Global Navigation Satellite System (GNSS) measurements have been available since 2016 in select Android smartphones. The availability of such observations allows smartphones users, in principle, to significantly improve the quality of GNSS-based positioning by applying customized and advanced positioning algorithms. However, the quality of such measurements is poor, mainly because of the low quality of smartphone hardware components and the nonideal environment in which phones are typically used. To overcome this problem and to separate the contribution of the hardware components and signal quality, dedicated test campaigns were carried out in a real environment and in a controlled-environment anechoic chamber using several different Android models. In addition, signal-processing techniques aimed at increasing the accuracy and precision of the solution were employed. Results show that the quality of the data captured in the anechoic chamber was significantly better than in real conditions. Furthermore, such analysis allows to underline certain phenomena in smartphones, such as the duty cycle, and to test the validity of anechoic environments for Android raw measurements.
Automatic Fault Diagnostic System for Induction Motors under Transient Regime Optimized with Expert Systems
Authors: Burriel-Valencia Jordi , Puche-Panadero Ruben , Martinez-Roman Javier , Sapena-Bano Angel , Pineda-Sanchez Manuel , Perez-Cruz Juan , Riera-Guasp Martin
Published: December 2018

Induction machines (IMs) power most modern industrial processes (induction motors) and generate an increasing portion of our electricity (doubly fed induction generators). A continuous monitoring of the machine’s condition can identify faults at an early stage, and it can avoid costly, unexpected shutdowns of production processes, with economic losses well beyond the cost of the machine itself. Machine current signature analysis (MCSA), has become a prominent technique for condition-based maintenance, because, in its basic approach, it is non-invasive, requires just a current sensor, and can process the current signal using a standard fast Fourier transform (FFT). Nevertheless, the industrial application of MCSA requires well-trained maintenance personnel, able to interpret the current spectra and to avoid false diagnostics that can appear due to electrical noise in harsh industrial environments. This task faces increasing difficulties, especially when dealing with machines that work under non-stationary conditions, such as wind generators under variable wind regime, or motors fed from variable speed drives. In these cases, the resulting spectra are no longer simple one-dimensional plots in the time domain; instead, they become two-dimensional images in the joint time-frequency domain, requiring highly specialized personnel to evaluate the machine condition. To alleviate these problems, supporting the maintenance staff in their decision process, and simplifying the correct use of fault diagnosis systems, expert systems based on neural networks have been proposed for automatic fault diagnosis. However, all these systems, up to the best knowledge of the authors, operate under steady-state conditions, and are not applicable in a transient regime. To solve this problem, this paper presents an automatic system for generating optimized expert diagnostic systems for fault detection when the machine works under transient conditions. The proposed method is first theoretically introduced, and then it is applied to the experimental diagnosis of broken bars in a commercial cage induction motor.
Partial Isolation Type Saddle-FinFET(Pi-FinFET) for Sub-30 nm DRAM Cell Transistors
Authors: Kim Young Kwon , Lee Jin Sung , Kim Geon , Park Taesik , Kim Hui Jung , Cho Young Pyo , Park Young June , Lee Myoung Jin
Published: December 2018

In this paper, we proposed a novel saddle type FinFET (S-FinFET) to effectively solve problems occurring under the capacitor node of a dynamic random-access memory (DRAM) cell and showed how its structure was superior to conventional S-FinFETs in terms of short channel effect (SCE), subthreshold slope (SS), and gate-induced drain leakage (GIDL). The proposed FinFET exhibited four times lower Ioff than modified S-FinFET, called RFinFET, with more improved drain-induced barrier lowering (DIBL) characteristics, while minimizing Ion reduction compared to RFinFET. Our results also confirmed that the proposed device showed improved drain-induced barrier lowering (DIBL) and Ioff characteristics as gate channel length decreased.
Soft-Decision Low-Complexity Chase Decoders for the RS(255,239) Code
Authors: Torres Vicente , Valls Javier , Canet Maria Jose , García-Herrero Francisco
Published: December 2018

In this work, we present a new architecture for soft-decision Reed–Solomon (RS) Low-Complexity Chase (LCC) decoding. The proposed architecture is scalable and can be used for a high number of test vectors. We propose a novel Multiplicity Assignment stage that sorts and stores only the location of the errors inside the symbols and the powers of α that identify the positions of the symbols in the frame. Novel schematics for the Syndrome Update and Symbol Modification blocks that are adapted to the proposed sorting stage are also presented. We also propose novel solutions for the problems that arise when a high number of test vectors is processed. We implemented three decoders: a η = 4 LCC decoder and two decoders that only decode 31 and 60 test vectors of true η = 5 and η = 6 LCC decoders, respectively. For example, our η = 4 decoder requires 29% less look-up tables in Virtex-V Field Programmable Gate Array (FPGA) devices than the best soft-decision RS decoder published to date, while has a 0.07 dB coding gain over that decoder.
Experimental Study on the Evaporation and Condensation Heat Transfer Characteristics of a Vapor Chamber
Authors: Liu Yanfei , Han Xiaotian , Shen Chaoqun , Yao Feng , Zhang Mengchen
Published: December 2018

A vapor chamber can meet the cooling requirements of high heat flux electronic equipment. In this paper, based on a proposed vapor chamber with a side window, a vapor chamber experimental system was designed to visually study its evaporation and condensation heat transfer performance. Using infrared thermal imaging technology, the temperature distribution and the vapor–liquid two-phase interface evolution inside the cavity were experimentally observed. Furthermore, the evaporation and condensation heat transfer coefficients were obtained according to the measured temperature of the liquid near the evaporator surface and the vapor near the condenser surface. The effects of heat load and filling rate on the thermal resistance and the evaporation and condensation heat transfer coefficients are analyzed and discussed. The results indicate that the liquid filling rate that maximized the evaporation heat transfer coefficient was different from the liquid filling rate that maximized the condensation heat transfer coefficient. The vapor chamber showed good heat transfer performance with a liquid filling rate of 33%. According to the infrared thermal images, it was observed that the evaporation/boiling heat transfer could be strengthened by the interference of easily broken bubbles and boiling liquid. When the heat input increased, the uniformity of temperature distribution was improved due to the intensified heat transfer on the evaporator surface.
Mechanical Characterization of Low Permeable Siltstone under Different Reservoir Saturation Conditions: An Experimental Study
Authors: Wanniarachchi Ayal , Pathegama Gamage Ranjith , Lyu Qiao , Perera Samintha , Wickramarathne Hiruni , Rathnaweera Tharaka
Published: December 2018

Hydro-fracturing is a common production enhancement technique used in unconventional reservoirs. However, an effective fracturing process requires a precise understanding of a formation’s in-situ strength behavior, which is mainly dependent on the formation’s in-situ stresses and fluid saturation. The aim of this study is to identify the effect of brine saturation (concentration and degree of saturation (DOS)) on the mechanical properties of one of the common unconventional reservoir rock types, siltstone. Most common type of non-destructive test: acoustic emission (AE) was used in conjunction with the destructive tests to investigate the rock properties. Unconfined compressive strength (UCS) and splitting tensile strength (STS) experiments were carried out for 78 varyingly saturated specimens utilizing ARAMIS (non-contact and material independent measuring system) and acoustic emission systems to determine the fracture propagation. According to the experimental results, the increase in degree of pore fluid saturation (NaCl ionic solution) causes siltstone’s compressive and tensile strengths to be reduced through weakening and breakage of the existing bonding between clay minerals. However, increasing NaCl concentration in the pore fluid generally enhances the compressive strength of siltstone through associated NaCl crystallization effect and actually reduces the tensile strength of siltstone through the corrosive influence of the NaCl ions. Moreover, results show that AE capture and analysis is one of the most effective methods to understand crack propagation behavior in rocks including the crack initiation, crack propagation, and final failure. The findings of this study are important for the identification of fluid saturation dependent in-situ strength conditions for successful hydro-fracturing in low permeable reservoirs.
Automatic Processing of User-Generated Content for the Description of Energy-Consuming Activities at Individual and Group Level
Authors: De Kok Roos , Mauri Andrea , Bozzon Alessandro
Published: December 2018

Understanding and improving the energy consumption behavior of individuals is considered a powerful approach to improve energy conservation and stimulate energy efficiency. To motivate people to change their energy consumption behavior, we need to have a thorough understanding of which energy-consuming activities they perform and how these are performed. Traditional sources of information about energy consumption, such as smart sensor devices and surveys, can be costly to set up, may lack contextual information, have infrequent updates, or are not publicly accessible. In this paper, we propose to use social media as a complementary source of information for understanding energy-consuming activities. A huge amount of social media posts are generated by hundreds of millions of people every day, they are publicly available, and provide real-time data often tagged to space and time. We design an ontology to get a better understanding of the energy-consuming activities domain and develop a text and image processing pipeline to extract from social media the description of energy-consuming activities. We run a case study on Istanbul and Amsterdam. We highlight the strength and weakness of our approach, showing that social media data has the potential to be a complementary source of information for describing energy-consuming activities.
A Novel Fault-Tolerant Control of Modular Multilevel Converter under Sub-Module Faults Based on Phase Disposition PWM
Authors: Yin Jingyuan , Wu Wen , Wei Tongzhen , Wu Xuezhi , Huo Qunhai
Published: December 2018

Each arm of modular multilevel converter (MMC) consists of a large number of sub-module (SM) units. However, it also increases the probability of SM failure during the long-term system operation. Focusing on the fault-tolerant operation issue for the MMC under SM faults, the traditional zero-sequence voltage injection fault-tolerant control algorithm is analyzed detailed and its disadvantages are concluded. Based on this, a novel fault-tolerant control strategy based on phase disposition pulse-width modulation (PD-PWM) is proposed in this paper, which has three main benefits: (i) it has carrier and modulation wave dual correction mechanism, which control ability is more higher and flexible; (ii) it only needs to inject zero-sequence voltage in half a cycle of the modulation wave, which simplifies the complexity of traditional zero-sequence voltage injection control algorithms and much easier for implement; (iii) furthermore, the zero-sequence voltage can even be avoided injecting under the symmetrical fault conditions. Finally, the effectiveness of the proposed control strategy is verified with the simulation and experiment studies under different fault conditions.
Security Risk Analysis of LoRaWAN and Future Directions
Authors: Butun Ismail , Pereira Nuno , Gidlund Mikael
Published: December 2018

LoRa (along with its upper layers definition—LoRaWAN) is one of the most promising Low Power Wide Area Network (LPWAN) technologies for implementing Internet of Things (IoT)-based applications. Although being a popular technology, several works in the literature have revealed vulnerabilities and risks regarding the security of LoRaWAN v1.0 (the official 1st specification draft). The LoRa-Alliance has built upon these findings and introduced several improvements in the security and architecture of LoRa. The result of these efforts resulted in LoRaWAN v1.1, released on 11 October 2017. This work aims at reviewing and clarifying the security aspects of LoRaWAN v1.1. By following ETSI guidelines, we provide a comprehensive Security Risk Analysis of the protocol and discuss several remedies to the security risks described. A threat catalog is presented, along with discussions and analysis in view of the scale, impact, and likelihood of each threat. To the best of the authors’ knowledge, this work is one of the first of its kind, by providing a detailed security risk analysis related to the latest version of LoRaWAN. Our analysis highlights important practical threats, such as end-device physical capture, rogue gateway and self-replay, which require particular attention by developers and organizations implementing LoRa networks.
Medicine in the Light of Evolution
Authors: Dolgova Olga , Lao Oscar
Published: December 2018

Evolutionary medicine applies the principles of evolutionary biology to understand why we get sick rather than how, and it has undergone an exponential growth since the early 1990s [...]
Evidence for Strong Kinship Influence on the Extent of Linkage Disequilibrium in Cultivated Common Beans
Authors: Diniz Augusto Lima , Giordani Willian , Costa Zirlane Portugal , Margarido Gabriel R. A. , Perseguini Juliana Morini K. C. , Benchimol-Reis Luciana L. , Chiorato Alisson F. , Garcia Antônio Augusto F. , Vieira Maria Lucia Carneiro
Published: December 2018

Phaseolus vulgaris is an important grain legume for human consumption. Recently, association mapping studies have been performed for the species aiming to identify loci underlying quantitative variation of traits. It is now imperative to know whether the linkage disequilibrium (LD) reflects the true association between a marker and causative loci. The aim of this study was to estimate and analyze LD on a diversity panel of common beans using ordinary r 2 and r 2 extensions which correct bias due to population structure ( r S 2 ), kinship ( r V 2 ), and both ( r V S 2 ). A total of 10,362 single nucleotide polymorphisms (SNPs) were identified by genotyping by sequencing (GBS), and polymorphisms were found to be widely distributed along the 11 chromosomes. In terms of r 2 , high values of LD (over 0.8) were identified between SNPs located at opposite chromosomal ends. Estimates for r V 2 were lower than those for r S 2 . Results for r V 2 and r V S 2 were similar, suggesting that kinship may also include information on population structure. Over genetic distance, LD decayed to 0.1 at a distance of 1 Mb for r V S 2 . Inter-chromosomal LD was also evidenced. This study showed that LD estimates decay dramatically according to the population structure, and especially the degree of kinship. Importantly, the LD estimates reported herein may influence our ability to perform association mapping studies on P. vulgaris.
Daily Regulation of Phototransduction, Circadian Clock, DNA Repair, and Immune Gene Expression by Heme Oxygenase in the Retina of Drosophila
Authors: Damulewicz Milena , Świątek Michał , Łoboda Agnieszka , Dulak Józef , Bilska Bernadetta , Przewłocki Ryszard , Pyza Elżbieta
Published: December 2018

The daily expression of genes and the changes in gene expression after silencing the heme oxygenase (ho) gene were examined in the retina of Drosophila using microarray and SybrGreen qPCR (quantitative polymerase chain reaction) methods. The HO decrease in the morning upregulated 83 genes and downregulated 57 genes. At night, 80 genes were upregulated and 22 were downregulated. The top 20 genes downregulated after ho silencing in the morning modulate phototransduction, immune responses, autophagy, phagocytosis, apoptosis, the carbon monoxide (CO) response, the oxidative stress/UV response, and translation. In turn, the genes that upregulated at night were involved in translation—the response to oxidative stress, DNA damage, and phototransduction. Among the top 20 genes downregulated at night were genes involved in phototransduction, immune responses, and autophagy. For some genes, a low level of HO had an opposite effect in the morning compared to those at night. Silencing ho also changed the expression of circadian clock genes, while the HO decrease during the night enhanced the expression of immune system genes. The results showed that the cyclic expression of HO is important for controlling several processes in the retina, including neuroprotection and those involved in the innate immune system.
Scientific Knowledge of the Moon, 1609 to 1969
Authors: Wood Charles A.
Published: December 2018

Discoveries stemming from the Apollo 11 mission solved many problems that had vexed scientists for hundreds of years. Research and discoveries over the preceding 360 years identified many critical questions and led to a variety of answers: How did the Moon form, how old is its surface, what is the origin of lunar craters, does the Moon have an atmosphere, how did the Moon change over time, is the Moon geologically active today, and did life play any role in lunar evolution? In general, scientists could not convincingly answer most of these questions because they had too little data and too little understanding of astronomy and geology, and were forced to rely on reasoning and speculation, in some cases wasting hundreds of years of effort. Surprisingly, by 1969, most of the questions had been correctly answered, but a paucity of data made it uncertain which answers were correct.
Maternal Pre-Pregnancy Cardiovascular Risk Factors and Offspring and Grandoffspring Health: Bogalusa Daughters
Authors: Harville Emily W. , Apolzan John W. , Bazzano Lydia A.
Published: December 2018

Both maternal pre-pregnancy body mass index (BMI) and gestational weight gain have been associated with cardiovascular health in the offspring beyond two generations. A total of 274 daughters (aged 12–54) of 208 mothers who participated in the Bogalusa Heart Study were interviewed about their reproductive history. Mothers’ data was taken from the original study, and cardiovascular measures at the visit prior to pregnancy were correlated with daughter’s measures. Maternal pre-pregnancy BMI, skinfold, and waist circumference were examined as a predictor of daughters’ blood pressure, lipids, and glucose, as well as a predictor of birthweight and gestational age of grandchildren. Maternal pre-pregnancy BMI was associated with higher blood pressure and lower low-density lipoprotein (LDL) and cholesterol in the daughters. Most maternal cardiometabolic risk factors were not associated with grandchildren’s birth outcomes, even though higher cholesterol and LDL was associated with lower gestational age, and higher BMI and skinfold thickness with an increased risk of preterm birth. In this pilot study, some associations were found between maternal adiposity and cardiovascular risk, daughters’ cardiovascular risk, and grandchild birth outcomes. Lack of conclusive associations could be due to a true lack of effect, effects being primarily mediated through daughter’s BMI, or the low power of the study.
The Impact of Land Use Transformations on Zooplankton Communities in a Small Mountain River (The Corgo River, Northern Portugal)
Authors: Sługocki Łukasz , Czerniawski Robert , Kowalska-Góralska Monika , Senze Magdalena , Reis Anabela , Carrola João S. , Teixeira Carlos A.
Published: December 2018

Transformation of the river catchment and the river bed cause significant changes in the functioning of river ecosystems. The main effects of anthropogenic transformations are hydrological changes, such as lower current velocity or an increase of nutrient content, and higher temperature. Zooplankton reacts rapidly to the new environmental conditions in rivers, increasing its richness and abundance. We tried to answer two questions: what type of catchment use has a greater influence on the zooplankton communities in a river and how do dam impoundments influence the zooplankton communities downstream? The study was conducted in the Corgo river (drainage of the Douro river, Northern Portugal) at 17 sampling sites in the lotic, free-flowing sections. Crustaceans present in the Corgo can attain relatively high densities in the rural section, which offers them better trophic conditions. The urban catchment use and the presence of dams have a greater impact on the rotifer density and the increase of zooplankton density downstream. The results of this study confirm that zooplankton properties allow for the evaluation of the degree of river-bed transformation.
Assessment of Three Antimicrobial Residue Concentrations in Broiler Chicken Droppings as a Potential Risk Factor for Public Health and Environment
Authors: Yévenes Karina , Pokrant Ekaterina , Pérez Fernando , Riquelme Ricardo , Avello Constanza , Maddaleno Aldo , San Martín Betty , Cornejo Javiera
Published: December 2018

Tetracyclines, sulfonamides and amphenicols are broad spectrum antimicrobial drugs that are widely used in poultry farming. However, a high proportion of these drugs can be excreted at high concentrations in droppings, even after the end of a therapy course. This work intended to assess and compare concentrations of florfenicol (FF), florfenicol amine (FFa), chlortetracycline (CTC), 4-epi-chlortetracycline (4-epi-CTC), and sulfachloropyridazine (SCP) in broiler chicken droppings. To this end, 70 chickens were housed under controlled environmental conditions, and assigned to experimental groups that were treated with therapeutic doses of either 10% FF, 20% CTC, or 10% SCP. Consequently, we implemented and designed an in-house validation for three analytical methodologies, which allowed us to quantify the concentrations of these three antimicrobial drugs using liquid chromatography coupled to mass spectrometry (LC-MS/MS). Our results showed that FF and FFa concentrations were detected in chicken droppings up to day 10 after ceasing treatment, while CTC and 4-epi-CTC were detected up to day 25. As for SCP residues, these were detected up to day 21. Noticeably, CTC showed the longest excretion period, as well as the highest concentrations detected after the end of its administration using therapeutic doses.
Improved Decision-Making Geo-Information System for Continuous Monitoring of Deformations on Airport Infrastructure
Authors: Doler Damjan , Kovačič Boštjan
Published: December 2018

Heavy burdens are placed on runways daily; thus, it is necessary to monitor these surfaces regularly. The appearance of distortions can cause difficulties for aircraft when they land or take off, which occurs mainly for lighter planes. This can be seen in reduced grip, uneven use of tires, problems with measurement systems, and unbalanced drive, which can result in damage to or even destruction of the plane or its parts. For that purpose, the model of continuous monitoring of distortions on and under the surface of the runway was created. This model is based on geodetic and geophysical methods. The method for monitoring distortions was developed into a decision-making model in the shape of a geo-information base. The results provide an image of the state of the runway including damage on and under the surface, which are the most common causes of runway distortions. The data are automatically recorded in the newly established information system, which supports the decision making regarding renovations and runway maintenance. The measurement on the runway takes 30 min, which does not lead to a long closure of the airport and, thus, reduces traffic jams and additional costs.
Combining Radiotherapy and Immunotherapy in Lung Cancer: Can We Expect Limitations Due to Altered Normal Tissue Toxicity?
Authors: Wirsdörfer Florian , De Leve Simone , Jendrossek Verena
Published: December 2018

In recent decades, technical advances in surgery and radiotherapy, as well as breakthroughs in the knowledge on cancer biology, have helped to substantially improve the standard of cancer care with respect to overall response rates, progression-free survival, and the quality of life of cancer patients. In this context, immunotherapy is thought to have revolutionized the standard of care for cancer patients in the long term. For example, immunotherapy approaches such as immune checkpoint blockade are currently increasingly being used in cancer treatment, either alone or in combination with chemotherapy or radiotherapy, and there is hope from the first clinical trials that the appropriate integration of immunotherapy into standard care will raise the success rates of cancer therapy to a new level. Nevertheless, successful cancer therapy remains a major challenge, particularly in tumors with either pronounced resistance to chemotherapy and radiation treatment, a high risk of normal tissue complications, or both, as in lung cancer. Chemotherapy, radiotherapy and immunotherapy have the capacity to evoke adverse effects in normal tissues when administered alone. However, therapy concepts are usually highly complex, and it is still not clear if combining immunotherapy with radio(chemo)therapy will increase the risk of normal tissue complications, in particular since normal tissue toxicity induced by chemotherapy and radiotherapy can involve immunologic processes. Unfortunately, no reliable biomarkers are available so far that are suited to predict the unique normal tissue sensitivity of a given patient to a given treatment. Consequently, clinical trials combining radiotherapy and immunotherapy are attracting major attention, not only regarding efficacy, but also with regard to safety. In the present review, we summarize the current knowledge of radiation-induced and immunotherapy-induced effects in tumor and normal tissue of the lung, and discuss the potential limitations of combined radio-immunotherapy in lung cancer with a focus on the suspected risk for enhanced acute and chronic normal tissue toxicity.
Computational and Experimental Tools to Monitor the Changes in Translation Efficiency of Plant mRNA on a Genome-Wide Scale: Advantages, Limitations, and Solutions
Authors: Goldenkova-Pavlova Irina V. , Pavlenko Olga S. , Mustafaev Orkhan N. , Deyneko Igor V. , Kabardaeva Ksenya V. , Tyurin Alexander A.
Published: December 2018

The control of translation in the course of gene expression regulation plays a crucial role in plants’ cellular events and, particularly, in responses to environmental factors. The paradox of the great variance between levels of mRNAs and their protein products in eukaryotic cells, including plants, requires thorough investigation of the regulatory mechanisms of translation. A wide and amazingly complex network of mechanisms decoding the plant genome into proteome challenges researchers to design new methods for genome-wide analysis of translational control, develop computational algorithms detecting regulatory mRNA contexts, and to establish rules underlying differential translation. The aims of this review are to (i) describe the experimental approaches for investigation of differential translation in plants on a genome-wide scale; (ii) summarize the current data on computational algorithms for detection of specific structure–function features and key determinants in plant mRNAs and their correlation with translation efficiency; (iii) highlight the methods for experimental verification of existed and theoretically predicted features within plant mRNAs important for their differential translation; and finally (iv) to discuss the perspectives of discovering the specific structural features of plant mRNA that mediate differential translation control by the combination of computational and experimental approaches.
Comparison of Reliable Reference Genes Following Different Hormone Treatments by Various Algorithms for qRT-PCR Analysis of Metasequoia
Authors: Wang Jing-Jing , Han Shuo , Yin Weilun , Xia Xinli , Liu Chao
Published: December 2018

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is the most sensitive technique for evaluating gene expression levels. Choosing appropriate reference genes for normalizing target gene expression is important for verifying expression changes. Metasequoia is a high-quality and economically important wood species. However, few systematic studies have examined reference genes in Metasequoia. Here, the expression stability of 14 candidate reference genes in different tissues and following different hormone treatments were analyzed using six algorithms. Candidate reference genes were used to normalize the expression pattern of FLOWERING LOCUS T and pyrabactin resistance-like 8. Analysis using the GrayNorm algorithm showed that ACT2 (Actin 2), HIS (histone superfamily protein H3) and TATA (TATA binding protein) were stably expressed in different tissues. ACT2, EF1α (elongation factor-1 alpha) and HIS were optimal for leaves treated with the flowering induction hormone solution, while Cpn60β (60-kDa chaperonin β-subunit), GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and HIS were the best reference genes for treated buds. EF1α, HIS and TATA were useful reference genes for accurate normalization in abscisic acid-response signaling. Our results emphasize the importance of validating reference genes for qRT-PCR analysis in Metasequoia. To avoid errors, suitable reference genes should be used for different tissues and hormone treatments to increase normalization accuracy. Our study provides a foundation for reference gene normalization when analyzing gene expression in Metasequoia.
A Dual Role of Heme Oxygenase-1 in Cancer Cells
Authors: Chiang Shih-Kai , Chen Shuen-Ei , Chang Ling-Chu
Published: December 2018

Heme oxygenase (HO)-1 is known to metabolize heme into biliverdin/bilirubin, carbon monoxide, and ferrous iron, and it has been suggested to demonstrate cytoprotective effects against various stress-related conditions. HO-1 is commonly regarded as a survival molecule, exerting an important role in cancer progression and its inhibition is considered beneficial in a number of cancers. However, increasing studies have shown a dark side of HO-1, in which HO-1 acts as a critical mediator in ferroptosis induction and plays a causative factor for the progression of several diseases. Ferroptosis is a newly identified iron- and lipid peroxidation-dependent cell death. The critical role of HO-1 in heme metabolism makes it an important candidate to mediate protective or detrimental effects via ferroptosis induction. This review summarizes the current understanding on the regulatory mechanisms of HO-1 in ferroptosis. The amount of cellular iron and reactive oxygen species (ROS) is the determinative momentum for the role of HO-1, in which excessive cellular iron and ROS tend to enforce HO-1 from a protective role to a perpetrator. Despite the dark side that is related to cell death, there is a prospective application of HO-1 to mediate ferroptosis for cancer therapy as a chemotherapeutic strategy against tumors.
Ribosome Structure, Function, and Early Evolution
Authors: Opron Kristopher , Burton Zachary F.
Published: December 2018

Ribosomes are among the largest and most dynamic molecular motors. The structure and dynamics of translation initiation and elongation are reviewed. Three ribosome motions have been identified for initiation and translocation. A swivel motion between the head/beak and the body of the 30S subunit was observed. A tilting dynamic of the head/beak versus the body of the 30S subunit was detected using simulations. A reversible ratcheting motion was seen between the 30S and the 50S subunits that slide relative to one another. The 30S–50S intersubunit contacts regulate translocation. IF2, EF-Tu, and EF-G are homologous G-protein GTPases that cycle on and off the same site on the ribosome. The ribosome, aminoacyl-tRNA synthetase (aaRS) enzymes, transfer ribonucleic acid (tRNA), and messenger ribonucleic acid (mRNA) form the core of information processing in cells and are coevolved. Surprisingly, class I and class II aaRS enzymes, with distinct and incompatible folds, are homologs. Divergence of class I and class II aaRS enzymes and coevolution of the genetic code are described by analysis of ancient archaeal species.
Brain Gray Matter Volume Is Modulated by Visual Input and Overall Learning Success but Not by Time Spent on Learning a Complex Balancing Task
Authors: Dordevic Milos , Taubert Marco , Müller Patrick , Kaufmann Jörn , Hökelmann Anita , Müller Notger G.
Published: December 2018

To better understand the process of neuroplasticity, this study assesses brain changes observed by voxel-based morphometry (VBM) in response to two different learning conditions. Twenty-two young, healthy subjects learned slacklining, a complex balancing task, with either their eyes open (EO, n = 11) or their eyes closed (EC, n = 11). The learning took place three times per week for four weeks, with learning periods of 1 hour, providing a total of 12 hours of learning. The scanning and testing protocols were applied at three time-points: (1) immediately before learning (baseline), (2) immediately afterwards (post-test), and (3) two months afterwards (follow-up). The EO group performed better on the task-specific test. Significant group*time interaction effects were found in sensory-motor areas at the post-test, with increases in the EO group only. The results suggest that VBM-observed brain changes in response to learning a complex balancing task vary depending on the learning success and the availability of visual input, and not solely on the amount of time spent on learning. These findings should be taken into account by future studies using similar methodologies.
The Mediating Role of Perceived Stress in the Relationship of Self-Efficacy and Work Engagement in Nurses
Authors: Pérez-Fuentes María del Carmen , Molero Jurado María del Mar , Barragán Martín Ana Belén , Simón Márquez María del Mar , Martos Martínez África , Gázquez Linares José Jesús
Published: December 2018

Positive occupational health psychology (POHP) examines the mechanisms that promote the health and wellbeing of workers, in addition to the risk factors arising from work activity. The aim of this study was to analyse the mediating role of perceived stress in the effect that self-efficacy has on engagement in nurses. The sample was comprised of 1777 currently working nurses. We administered the Utrecht Work Engagement Scale (UWES), the Perceived Stress Questionnaire and the General Self-Efficacy Scale. Following bivariate correlational analysis, multiple linear regression analysis and simple and multiple mediation analysis, the results showed self-efficacy to be a powerful personal resource that positively predicts employee engagement, although the effect diminishes when there are mediating variables of stress. We found differences in the way the different aspects of stress mediated the relationship between self-efficacy and the engagement dimensions. “Energy–joy” was the strongest mediating variable for all of the engagement dimensions and this, together with “harassment–social acceptance” dampened the effect of self-efficacy on vigour and dedication, whereas “Overload” was only a mediator for dedication. As nurses work in a stressful environment, risk factors arise from work activity, so hospital management should design interventions to enhance their workers’ personal resources and improve personal and organizational wellbeing.
Testosterone Therapy, Thrombophilia, Venous Thromboembolism, and Thrombotic Events
Authors: Glueck Charles J. , Goldenberg Naila , Wang Ping
Published: December 2018

In our sequential studies of 67 and 21 patients, testosterone therapy (TT) interacted with thrombophilia–hypofibrinolysis, leading to venous thromboembolism (VTE). Compared to 111 VTE controls not taking TT (VTE-no TT), the 67 and 21 cases were more likely (p < 0.05 for all) to have Factor V Leiden (FVL) heterogeneity (24% and 33% vs. 12%), the lupus anticoagulant (14% and 33% vs. 4%), and high lipoprotein(a) (33% vs. 13%, n = 21). After a first VTE and continuing TT, 11 thrombophilic cases had a second VTE despite adequate anticoagulation, 6 of whom, still anticoagulated, had a third VTE. The greatest density of thrombotic events was at three months after starting TT, with a rapid decline by 10 months. From <1 to 8 months after starting TT, 65% of VTE occurred, which may reflect TT-induced depletion of susceptible thrombophilic patients, leaving a winnowed residual group with fewer VTE events despite the continuation of TT. Before starting TT, we suggest screening for FVL, lipoprotein(a), and the lupus anticoagulant to identify patients at increased VTE risk, with an adverse risk-to-benefit ratio for TT. We suggest that TT should not be started in patients with known thrombophilia–hypofibrinolysis, and should not be continued after a first VTE. When TT is given to patients with thrombophilia–hypofibrinolysis, VTE may occur and then recur despite adequate anticoagulation.
Effects of Corticosteroid Treatment and Antigen Avoidance in a Large Hypersensitivity Pneumonitis Cohort: A Single-Centre Cohort Study
Authors: De Sadeleer Laurens J. , Hermans Frederik , De Dycker Els , Yserbyt Jonas , Verschakelen Johny A. , Verbeken Eric K. , Verleden Geert M. , Wuyts Wim A.
Published: December 2018

Background: Although the third most frequent interstitial lung disease, hypersensitivity pneumonitis (HP) remains an enigmatic disease without clear diagnostic and therapeutic guidelines. We assessed the effect of the commonly used therapeutic interventions (i.e. exposure avoidance and corticosteroid treatment) in an HP cohort. Methods: We collected clinical data of all HP patients followed at our centre between January 1, 2005, and December 31, 2016. HP patients were stratified according to the presence of fibrosis on chest CT. Survival was analysed using the multivariate Cox proportional hazards model. Forced vital capacity (percent predicted, FVC%) and diffusing capacity of the lung for carbon monoxide (percent predicted, DLCO%) evolution were analysed using linear mixed-effect models. Results: Two hundred and two HP patients were identified: 93 non-fibrotic HP (nfHP) and 109 fibrotic HP (fHP), experiencing a monthly FVC% decline before treatment of 0.93% and 0.56%, respectively. While nfHP had an excellent survival, fHP patients experienced a median survival of 9.2 years. Corticosteroid treatment and exposure avoidance did not result in survival differences. Although nfHP patients showed FVC% and DLCO% increase after corticosteroid initiation, no therapeutic effect was seen in fHP patients. FVC% and DLCO% increased in nfHP patients after exposure avoidance, while a positive numerical trend was seen for FVC% after exposure avoidance in fHP patients (p = 0.15). Conclusions: nfHP patients experienced an excellent survival with good therapeutic effect on pulmonary function tests with both corticosteroid initiation as well as antigen avoidance. In contrast, fHP patients experienced a dismal prognosis (median survival of 9.2 years) without any therapeutic effect of corticosteroid treatment. Whether antigen avoidance is useful in fHP patients is still unclear.
Risk of Infection with Methotrexate Therapy in Inflammatory Diseases: A Systematic Review and Meta-Analysis
Authors: Ibrahim Ammar , Ahmed Mohammed , Conway Richard , Carey John J.
Published: December 2018

The aim of this study was to determine the risk of infection in adults with inflammatory rheumatic diseases (IRDs) treated with methotrexate. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing methotrexate versus placebo in adults using MEDLINE, EMBASE, and CENTRAL databases from 1980 to August 2017. The primary outcome was the risk of infection associated with methotrexate therapy. We chose a random effect model to summarize adverse event outcomes as risk ratios (RRs) and related 95% confidence intervals (95% CI). Twelve RCTs (total patients 1146) met the inclusion criteria for our main analysis, and ten for risk of serious infection (total patients 906). Overall, methotrexate was associated with increased risk of infection in rheumatoid arthritis (RA) (RR: 1.25; 95% CI, 1.01–1.56; p = 0.04; I2 = 0%), but not in other non-RA IRD populations. There was no increased risk of total infections (RR: 1.14; 95% CI, 0.98–1.34; p = 0.10; I2 = 0%) or serious infections (RR: 0.76; 95% CI, 0.11–5.15; p = 0.78; I2 = 0%) in all included IRDs. Conclusively, methotrexate use in IRDs is associated with a higher risk of all infections in RA, but not in other non-RA (IRD) populations. There is no increased risk of serious infections.
Hierarchical Control of an Integrated Fuel Processing and Fuel Cell System
Authors: Ohenoja Markku , Ruusunen Mika , Leiviskä Kauko
Published: December 2018

An advanced model-based control method for the integrated fuel processing and a fuel cell system consisting of ethanol reforming, hydrogen purification, and a proton exchange membrane fuel cell is presented. For process identification, a physical model of the process chain was constructed. Subsequently, the simulated process was approximated with data-driven control models. Based on these control models, a hierarchical control framework consisting of model predictive controller and a global optimization algorithm was introduced. The performance of the new control method was evaluated with simulations. Results indicate that the new optimization concept enables resource efficient and fast control of the studied energy conversion process. Fast and efficient fuel cell process could then provide sustainable power source for autonomous and mobile applications in the future.
Demineralization, Collagen Modification and Remineralization Degree of Human Dentin after EDTA and Citric Acid Treatments
Authors: Gandolfi Maria Giovanna , Taddei Paola , Pondrelli Anna , Zamparini Fausto , Prati Carlo , Spagnuolo Gianrico
Published: December 2018

The aim of the study was to investigate the effects of several decalcifying agents used as irrigant solutions in endodontic treatment on collagen and mineral components of dentin. Coronal dentin discs from five caries-free human third molars with a smear layer were treated for one minute with a chelating solution (1% Ethylenediaminetetraacetic acid (EDTA), 10% EDTA, 17% EDTA, 10% citric acid). Mineralization degree (Ca/N and P/N atomic ratios, IR Iapatite/Iamide II and I1410(carbonate)/I554(phosphate) spectroscopic ratios) and possible collagen rearrangements (collagen infrared (IR) amide II e III shifts) were evaluated by environmental scanning electron microscopy (ESEM)/energy dispersive X-ray spectroscopy (EDX) and IR spectroscopy before and after treatment (T0) and after ageing (T24h and T2m) in simulated body fluid (SBF). At T0, analysis showed that the highest demineralizing effect was achieved using a 10% citric acid solution and 10% EDTA, while the smallest effect was observed when using 17% EDTA. No significant collagen modifications were detected upon treatment with 1% EDTA, while subtle changes were observed after the other treatments. At T24h or T2m, analyses showed the highest remineralization values for 1% EDTA and the lowest for 10% citric acid, mainly at T2m. The samples treated with 17% EDTA showed slight collagen rearrangements upon remineralization. In conclusion, the highest demineralizing effect was observed for 10% EDTA and 10% citric acid. Collagen rearrangement was found for all the treatments except for 1% EDTA. The highest remineralization capability in SBF values was recorded for 1% EDTA and the lowest for 10% citric acid. A slight collagen rearrangement upon remineralization was still present in 17% EDTA-treated samples. Clinical use as a chelating agent in the endodontic therapy of citric acid and concentrated EDTA solutions should be reconsidered.
Study of Resistive-Type Superconducting Fault Current Limiters for a Hybrid High Voltage Direct Current System
Authors: Chen Lei , He Huiwen , Li Guocheng , Chen Hongkun , Wang Lei , Chen Xiaoyuan , Tian Xin , Xu Ying , Ren Li , Tang Yuejin
Published: December 2018

In this paper, a hybrid high voltage direct current transmission system containing a line commutated converter and a voltage source converter is developed. To enhance the robustness of the hybrid transmission system against direct current short-circuit faults, resistive-type superconducting fault current limiters are applied, and the effectiveness of this approach is assessed. Related mathematical models are built, and the theoretical functions of the proposed approach are expounded. According to the transient simulations in MATLAB software, the results demonstrate that: (i) The superconducting fault current limiter at the voltage source converter station enables to very efficiently mitigate the fault transients, and owns an enhanced current-limiting ability for handling the short-line faults. (ii) The superconducting fault current limiter at the line commutated converter station is able to mildly limit the fault current and alleviate the voltage drop, and its working performance has a low sensitivity to the fault location. At the end of the study, a brief scheme design of the resistive-type superconducting fault current limiters is achieved. In conclusion, the application feasibility of the proposed approach is well confirmed.