bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemodynamics of infants with strong fluctuations of internal cerebral vein
Authors: Ikeda Toshifumi , Ito Yuya , Mikami Ryosuke , Matsuo Koji , Kawamura Naoto , Yamoto Akane
Published: March 2019

Background

There is a high incidence of intraventricular hemorrhage in extremely low‐birthweight (ELBW) infants of low gestational age with high‐grade fluctuations in the perfusion waveform of the internal cerebral vein. This study investigated changes in the hemodynamic status of ELBW infants during initial strong fluctuations in the perfusion waveform of the internal cerebral vein.

Methods

We evaluated the perfusion waveform of the internal cerebral vein in 192 ELBW infants from birth, every 8 h for a total of 120 h. Sixty‐seven infants had high‐grade fluctuations. On the basis of the presence of patent ductus arteriosus (PDA), patients were subdivided into PDA(−) (n = 32) and PDA(+) (n = 35) groups.

Results

During the first high‐grade fluctuation, the PDA(−) group had significant increases in systolic, diastolic, and mean blood pressure (P < 0.001 for all). The PDA(+) group did not have significant changes in blood pressure but did have significant increases in the number of interruptions or regurgitations of diastolic renal arterial blood flow (P = 0.04) and end‐diastolic left pulmonary arterial flow velocity (P < 0.001), indicating increased left‐to‐right shunt.

Conclusions

Blood pressure elevation may underlie fluctuations in the perfusion waveform of the internal cerebral vein and lead to the first high‐grade increases during acute management of ELBW infants. When no elevation in blood pressure occurred, hemodynamically significant PDA was considered a potential underlying factor.
Influence of caregiver burden on well‐being of family member caregivers of older adults
Authors: OR Recep , Kartal Asiye
Published: March 2019

Background

Caregiving to older adults is one of the most important social issues associated with aging. While caregiving provides a suitable care and supportive environment for older adults, changes in the lives of caregiving family members also affect their health. The aim of this study was to examine the effect of care burden on the well‐being of family members providing care for older adults.

Methods

The study used a cross‐sectional design. The study sample included 363 family caregivers of older adults. Socio‐demographic questionnaire form, Burden Interview and Caregiver Well‐Being Scale were used as data collection tools. Multiple linear regression analysis was performed to explore the predictors of well‐being in the family caregivers of older adults.

Results

The caregiver burden mean score was 32.63 ± 15.72 and Caregiver Well‐Being Mean score was 159.38 ± 24.55. Caregiver burden, perceived health status of the older adults, marital status, perceived health status of caregiver and social support of caregiver were found to be statistically significant predictors of well‐being in family member caregivers of older adults. Caregiver burden level was found to be the strongest predictor of well‐being in the family caregivers of older adults.

Conclusion

Results showed that caregiver burden had an important effect on well‐being of the caregiver. For this reason caregiver burden should be considered during interventions for improving well‐being in family caregivers of older adults. Findings of our study revealed the necessity of showing special attention to caregivers by healthcare professionals and the importance of conducting interventional studies that aim to reduce caregiver burden in order to promote well‐being.
Inflation Expectations and Monetary Policy Surprises*
Authors: Eminidou Snezana , Zachariadis Marios , Andreou Elena
Published: March 2019

We estimate monetary policy surprises for European consumers over time, based on monetary policy changes that were unanticipated according to consumers’ stated beliefs. We find that such monetary policy surprises have the opposite impact on inflation expectations from the impact found when assuming that consumers are well informed. Relaxing the latter assumption by focusing on consumers’ stated beliefs, unanticipated increases in the interest rate raise inflation expectations before the 2008 financial crisis. This is consistent with imperfect information theoretical settings where interest rate hikes are interpreted as positive news about the state of the economy by consumers who know that policymakers have relatively more information.
Prices or Quantities Can Dominate Banking and Borrowing*
Authors: Weitzman Martin L.
Published: March 2019

The possibility of intertemporal banking and borrowing of tradable permits is often viewed as tilting the various policy debates about optimal pollution control instruments towards favoring such time‐flexible quantities. This paper shows that this view can be misleading, at least for the simplest dynamic extension of the original “prices versus quantities” information structure. The model of this paper allows firms to know and act upon the realization of uncertain future costs two full periods ahead of the regulators. For any given circumstance, the paper shows that either a fixed price or a fixed quantity is superior in expected welfare to time‐flexible banking and borrowing. Furthermore, the standard original formula for the comparative advantage of prices over quantities contains sufficient information to completely characterize the regulatory role of intertemporal banking and borrowing. The logic and implications of these results are analyzed and discussed.
Examination of the Level of State- Trial Anxiety of Elite Level Archers from Several Variables
Authors: Saçakli Haluk
Published: March 2019

The purpose of this study is to examine the state and trait anxiety levels of the individuals who perform archery sports at the elite level according to different variables. The population of the study was held from constitute archers who participated in the archery tournament "Turkey Cup" in 2018 (N=421). Also, the sample of the research was the volunteer athletes determined by the simple random sampling method (n = 156). The study was conducted by applying the causal comparison method in the screening model. The data collected by the survey technique. Participants were provided with a personal information form and Trait and State Anxiety Inventory. The obtained data transferred to SPSS 22 packet program and one-way ANOVA and Independent Sample T-test statistic applied as the statistical process for study purpose. This study demonstrates that there was a significant difference between the participants' level of trait anxiety according to gender variable and state anxiety levels according to the bow categories they used. Also the study demonstrates that there was a significant difference between the participants' level of trait anxiety according to gender variable and state anxiety levels according to the bow categories they used.
Análisis de los costos de producción y la cadena de valor de las plantas tradicionales que cultivan los campesinos de Cundinamarca, Colombia
Authors: Husain-Talero Soraya
Published: March 2019

El artículo analiza los costos de producción y la cadena de valor de las plantas tradicionales que cultivan los campesinos de Cundinamarca, específicamente del municipio de Chipaque. Así, se evidencian los retos productivos a los que se enfrentan, dadas las tensiones entre la racionalidad economicista y una racionalidad alternativa en la cual se toman en cuenta las prácticas socioeconómicas junto con las diversas formas de valorar. Se resalta el carácter heterogéneo de los campesinos y el funcionamiento de la cadena de valor de las plantas tradicionales desde la parcela hasta las ventas en la plaza de mercado municipal, en la ciudad de Bogotá, y a partir del proceso de deshidratación.
Microfinanzas y pobreza rural en México: un análisis con técnicas de propensity score matching
Authors: Mora-Rivera Jorge , García-Mora Fernando
Published: March 2019

El objetivo de este artículo es estimar el efecto que tiene el uso de las microfinanzas en la pobreza por ingresos de los hogares del sector rural mexicano. Empleando información de la Encuesta Coneval a Hogares Rurales de México 2013 (EnChor 2013) (Consejo Nacional de Evaluación de la Política de Desarrollo Social [Coneval], 2013) y técnicas de propensity score matching, los resultados de esta investigación muestran que el uso de los microcréditos contribuye a disminuir los niveles de pobreza de los hogares rurales en México. Estos hallazgos ponen de manifiesto la necesidad de crear políticas públicas que permitan incorporar a un mayor número de hogares pobres al mercado de las microfinanzas, lo cual incrementaría los niveles de vida de las personas que viven en este sector.
The genus Kunstidamaeus (Acari, Oribatida, Damaeidae) in Asia, with description of a new species from Taiwan
Authors: Miko Ladislav , Ermilov Sergey G.
Published: March 2019

A new oribatid mite species of the genus Kunstidamaeus Miko, 2006 (Oribatida, Damaeidae) is described from Taiwan, based on adult and tritonymphal instar; Kunstidamaeus yilanensis sp. nov. differs from similar damaeid species by the long and flagellate interlamellar, exobothridial and some epimeral setae (3c, 4c, 4d), and the presence of prodorsal tubercles Da, Ba and La, prodorsal enantiophyses and ventrosejugal tubercles. Four Asian species, originally described as species of Epidamaeus Bulanova-Zachvatkina, 1957, are transferred to the genus Kunstidamaeus: K. fragilis (Enami & Fujikawa, 1989) comb. nov., K. parayunnanensis (Ermilov & Kalúz, 2013) comb. nov., K. verrucatus (Enami & Fujikawa, 1989) comb. nov., K. yunnanensis (Enami, Aoki & Hu, 1994) comb. nov.
Electromechanical equivalent circuit of the radially polarized cylindrical piezoelectric transducer in coupled vibration
Authors: Xu Jie , Lin Shuyu
Published: March 2019

Electromechanical equivalent circuit of the radially polarized cylindrical piezoelectric transducer in coupled vibration is obtained. The equivalent elasticity method is used to analyze the coupled vibration. It is an approximate analytical method, ignoring the shear and torsion stresses and strains, dividing the coupled vibration into the extensional radial and longitudinal vibrations. A mechanical coupling coefficient is introduced to connect these two equivalent vibrations. According to the electromechanical equivalent circuit, the resonance frequency equations as functions of the frequency and the mechanical coupling coefficient are acquired. The sound pressure level and far field sound pressure distribution for the transducer in water are simulated. It is demonstrated that the radiation range of the cylindrical transducer is larger than that of the ring-type transducer. Several prototypes of the transducer are fabricated; the radial and longitudinal resonance frequencies are measured. The experimental resonance frequencies are in good agreement with the analytical results. The acquisition of the electromechanical equivalent circuit contributes to analyzing the electromechanical characteristics of the radial polarized cylindrical transducer.
Investigation on the diffusive surface modeling detail in geometrical acoustics based simulations
Authors: Shtrepi Louena
Published: March 2019

This study shows an investigation on the modeling level of detail of diffusive surfaces, which strongly influences the efficiency of geometrical acoustic based software. One diffusive condition of the lateral wall of a shoebox hall has been modeled as (a) flat surfaces with surface scattering coefficient and (b) three-dimensional relief including edge diffraction. The analysis has been performed by comparing the conventional acoustic parameters, which showed no significant differences, and by subjectively investigating the sensitivity of listeners to both modeling approaches, which highlighted that perceptual differences related to reverberance and spaciousness are clearer when using the modeling approach (b).
Between-speaker variability and temporal organization of the first formant
Authors: He Lei , Zhang Yu , Dellwo Volker
Published: March 2019

First formant (F1) trajectories of vocalic intervals were divided into positive and negative dynamics. Positive F1 dynamics were defined as the speeds of F1 increases to reach the maxima, and negative F1 dynamics as the speeds of F1 decreases away from the maxima. Mean, standard deviation, and sequential variability were measured for both dynamics. Results showed that measures of negative F1 dynamics explained more between-speaker variability, which was highly congruent with a previous study using intensity dynamics [He and Dellwo (2017). J. Acoust. Soc. Am. 141, EL488–EL494]. The results may be explained by speaker idiosyncratic articulation.
The Quinazolinone Allosteric Inhibitor of PBP 2a Synergizes with Piperacillin and Tazobactam against Methicillin-Resistant Staphylococcus aureus
Authors: Janardhanan Jeshina , Bouley Renee , Martínez-Caballero Siseth , Peng Zhihong , Batuecas-Mordillo Mayte , Meisel Jayda E. , Ding Derong , Schroeder Valerie A. , Wolter William R. , Mahasenan Kiran V. , Hermoso Juan A. , Mobashery Shahriar , Chang Mayland
Published: March 2019

The quinazolinones are a new class of antibacterials with
in vivo
efficacy against methicillin-resistant
Staphylococcus aureus
(MRSA). The quinazolinones target cell wall biosynthesis and have a unique mechanism of action by binding to the allosteric site of penicillin-binding protein 2a (PBP 2a).
Cooperative Interactions between
Trichomonas vaginalis
and Associated Bacteria Enhance Paracellular Permeability of the Cervicovaginal Epithelium by Dysregulating Tight Junctions
Authors: Hinderfeld Annabel S. , Phukan Niha , Bär Ann-Katrein , Roberton Anthony M. , Simoes-Barbosa Augusto
Published: March 2019

The human protozoan
Trichomonas vaginalis
is the causative agent of trichomoniasis, a prevalent sexually transmitted infection, which is accompanied by a species-diversified vaginal microbiota named community state type IV (CST-IV). Coincidently, CST-IV includes species associated with bacterial vaginosis (e.g.
Activity of Spore-Specific Respiratory Nitrate Reductase 1 of
Streptomyces coelicolor
A3(2) Requires a Functional Cytochrome
bcc-aa
3
Oxidase Supercomplex
Authors: Falke Dörte , Biefel Bianca , Haase Alexander , Franke Stefan , Fischer Marco , Sawers R. Gary
Published: March 2019

Streptomyces coelicolor
forms spores that respire with either oxygen or nitrate, using only endogenous electron donors. This helps maintain a membrane potential and, thus, viability. Respiratory nitrate reductase (Nar) usually receives electrons directly from reduced quinone species; however, we show that nitrate respiration in spores requires a respiratory supercomplex comprising cytochrome
bcc
oxidoreductase and
aa
3
oxidase. Our findings suggest that the Nar1 enzyme in the
S. coelicolor
spore functions together with the proton-translocating
bcc-aa
3
supercomplex to help maintain the membrane potential more efficiently. Dissecting the mechanisms underlying this survival strategy is important for our general understanding of bacterial persistence during infection processes and of how bacteria might deal with nutrient limitation in the natural environment.
Suppressor Mutations in
degS
Overcome the Acute Temperature-Sensitive Phenotype of Δ
degP
and Δ
degP
Δ
tol-pal
Mutants of Escherichia coli
Authors: Kern Brea , Leiser Owen P. , Misra Rajeev
Published: March 2019

The Tol-Pal complex plays a poorly defined role in envelope biogenesis. The data presented here show that DegP’s periplasmic protease activity becomes crucial in mutants lacking the intact Tol-Pal complex, but this requirement can be circumvented by suppressor mutations that activate the basal protease activity of a regulatory protease, DegS. These observations point to a critical role for periplasmic proteases when Tol-Pal-mediated envelope structure and/or functions are perturbed.
Modulation of the CCR5 Receptor/Ligand Axis by Seminal Plasma and the Utility of
In Vitro
versus
In Vivo
Models
Authors: Juno Jennifer A. , Wragg Kathleen M. , Kristensen Anne B. , Lee Wen Shi , Selva Kevin J. , van der Sluis Renee M. , Kelleher Anthony D. , Bavinton Benjamin R. , Grulich Andrew E. , Lewin Sharon R. , Kent Stephen J. , Parsons Matthew S.
Published: March 2019

The majority of HIV-1 vaccine studies do not take into consideration the impact that semen exposure might have on the mucosal immune system. In this study, we demonstrate that seminal plasma (SP) exposure can alter CCR5 expression on T cells. Importantly,
in vitro
studies of T cells in culture cannot replicate the conditions under which immune cells might be recruited to the genital mucosa
in vivo
, leading to potentially erroneous conclusions about the impact of semen on mucosal HIV-1 susceptibility.
Design and Characterization of Cholesterylated Peptide HIV-1/2 Fusion Inhibitors with Extremely Potent and Long-Lasting Antiviral Activity
Authors: Zhu Yuanmei , Chong Huihui , Yu Danwei , Guo Yan , Zhou Yusen , He Yuxian
Published: March 2019

The peptide drug enfuvirtide (T-20) remains the only membrane fusion inhibitor available for treatment of viral infection, which is used in combination therapy of HIV-1 infection; however, it exhibits relatively low antiviral activity and a genetic barrier to inducing resistance, calling for the continuous development for novel anti-HIV agents. In this study, we report cholesterylated fusion inhibitors showing the most potent and broad anti-HIV activities to date. The new inhibitors have been comprehensively characterized for their modes of action and druggability, including small size, low cytotoxicity, binding ability to human serum albumin (HSA), and, especially, extremely potent and long-lasting antiviral activity in rhesus monkeys. Therefore, the present studies have provided new drug candidates for clinical development, which can also be used as tools to probe the mechanisms of viral entry and inhibition.
RstA Is a Major Regulator of Clostridioides difficile Toxin Production and Motility
Authors: Edwards Adrianne N. , Anjuwon-Foster Brandon R. , McBride Shonna M.
Published: March 2019

Clostridioides difficile
is an anaerobic, gastrointestinal pathogen of humans and other mammals.
C. difficile
produces two major toxins, TcdA and TcdB, which cause the symptoms of the disease, and forms dormant endospores to survive the aerobic environment outside the host. A recently discovered regulatory factor, RstA, inhibits toxin production and positively influences spore formation. Herein, we determine that RstA directly binds its own promoter DNA to repress its own gene transcription. In addition, our data demonstrate that RstA directly represses toxin gene expression and gene expression of two toxin gene activators, TcdR and SigD, creating a complex regulatory network to tightly control toxin production. This study provides a novel regulatory link between
C. difficile
sporulation and toxin production. Further, our data suggest that
C. difficile
toxin production is regulated through a direct, species-specific sensing mechanism.
Methane-Linked Mechanisms of Electron Uptake from Cathodes by Methanosarcina barkeri
Authors: Rowe Annette R. , Xu Shuai , Gardel Emily , Bose Arpita , Girguis Peter , Amend Jan P. , El-Naggar Mohamed Y.
Published: March 2019

Methanogenic archaea are of fundamental applied and environmental relevance. This is largely due to their activities in a wide range of anaerobic environments, generating gaseous reduced carbon that can be utilized as a fuel source. While the bioenergetics of a wide variety of methanogens have been well studied with respect to soluble substrates, a mechanistic understanding of their interaction with solid-phase redox-active compounds is limited. This work provides insight into solid-phase redox interactions in
Methanosarcina
spp. using electrochemical methods. We highlight a previously undescribed mode of electron uptake from cathodes that is potentially informative of direct interspecies electron transfer interactions in the
Methanosarcinales
.
A Role for Tetracycline Selection in Recent Evolution of Agriculture-Associated
Clostridium difficile
PCR Ribotype 078
Authors: Dingle Kate E. , Didelot Xavier , Quan T. Phuong , Eyre David W. , Stoesser Nicole , Marwick Charis A. , Coia John , Brown Derek , Buchanan Sarah , Ijaz Umer Z. , Goswami Cosmika , Douce Gill , Fawley Warren N. , Wilcox Mark H. , Peto Timothy E. A. , Walker A. Sarah , Crook Derrick W.
Published: March 2019

Clostridium difficile
PCR ribotype 078 (RT078) has multiple reservoirs; many are agricultural. Since 2005, this genotype has been increasingly associated with human infections in both clinical settings and the community. Investigations of RT078 whole-genome sequences revealed that tetracycline resistance had been acquired on multiple independent occasions. Phylogenetic analysis revealed a rapid, recent increase in numbers of closely related tetracycline-resistant RT078 (clonal expansions), suggesting that tetracycline selection has strongly influenced its recent evolutionary history. We demonstrate recent international spread of emergent, tetracycline-resistant RT078. A similar tetracycline-positive clonal expansion was also identified in unrelated nontoxigenic
C. difficile
, suggesting that this process may be widespread and may be independent of disease-causing ability. Resistance to typical
C. difficile
infection-associated antimicrobials (e.g., fluoroquinolones, clindamycin) occurred only sporadically within RT078. Selective pressure from tetracycline appears to be a key factor in the emergence of this human pathogen and the rapid international dissemination that followed, plausibly via the food chain.
Effectiveness and cost-effectiveness randomised controlled trial of basic versus biofeedback-mediated intensive pelvic floor muscle training for female stress or mixed urinary incontinence: protocol for the OPAL (optimising pelvic floor exercises to achieve long-term benefits) trial mixed methods longitudinal qualitative case study and process evaluation
Authors: Grant Aileen , Dean Sarah , Hay-Smith Jean , Hagen Suzanne , McClurg Doreen , Taylor Anne , Kovandzic Marija , Bugge Carol
Published: March 2019

Introduction

Female urinary incontinence (UI) is common affecting up to 45% of women. Pelvic floor muscle training (PFMT) is the first-line treatment but there is uncertainty whether intensive PFMT is better than basic PFMT for long-term symptomatic improvement. It is also unclear which factors influence women’s ability to perform PFMT long term and whether this has impacts on long-term outcomes. OPAL (optimising PFMT to achieve long-term benefits) trial examines the effectiveness and cost-effectiveness of basic PFMT versus biofeedback-mediated PFMT and this evaluation explores women’s experiences of treatment and the factors which influence effectiveness. This will provide data aiding interpretation of the trial findings; make recommendations for optimising the treatment protocol; support implementation in practice; and address gaps in the literature around long-term adherence to PFMT for women with stress or mixed UI.

Methods and analysis

This evaluation comprises a longitudinal qualitative case study and process evaluation (PE). The case study aims to explore women’s experiences of treatment and adherence and the PE will explore factors influencing intervention effectiveness. The case study has a two-tailed design and will recruit 40 women, 20 from each trial group; they will be interviewed four times over 2 years. Process data will be collected from women through questionnaires at four time-points, from health professionals through checklists and interviews and by sampling 100 audio recordings of appointments. Qualitative analysis will use case study methodology (qualitative study) and the framework technique (PE) and will interrogate for similarities and differences between the trial groups regarding barriers and facilitators to adherence. Process data analyses will examine fidelity, engagement and mediating factors using descriptive and interpretative statistics.

Ethics and dissemination

Approval from West of Scotland Research Ethics Committee 4 (16/LO/0990). Findings will be published in journals, disseminated at conferences and through the final report.

Trial registration number

ISRCTN57746448.
Enhanced electrical performance by modulation-doping in AlGaN-based deep ultraviolet light-emitting diodes
Authors: Yang Sipan , He Miao , Yan Jianchang , Wen Kunhua , Wang Junxi , Guo Yanan , Xiong Deping
Published: March 2019

Through the silicon modulation-doping (MD) growth method, the electrical performance of AlGaN-based deep ultraviolet light-emitting diodes (DUV-LEDs) is improved by replacing the commonly uniform-doped (UD) method of n-AlGaN layer. The electroluminescence characterisic measurements demonstrate the MD growth method could effectively enhance the light emission intensity. Both the forward voltage and reverse leakage current of the MD samples are obviously reduced compared to those of the UD sample. Due to the existence of periodic Si-MD superlattices in n-AlGaN layers, which may behave like a series of capacitors, the built-in electric fields are formed. Both the measured capacitance–voltage (C–V) characteristics, and related photoluminescence (PL) intensity with the Si-MD growth method are enhanced. In detail, the effects of these capacitors can enhance the peak internal capacitance up to 370 pF in the MD sample, whereas the UD sample is only 180 pF. The results also mean that with better current spreading ability in the MD sample, the MD processes can effectively enhance the efficiency and reliability of DUV-LEDs. Thus, the investigations of the Si-MD growth methods may be useful for improving the electrical performance of DUV-LEDs in future works. Meanwhile, this investigation may partly suggest the minor crystalline quality improvements in the epi-layers succeeding the MD n-AlGaN layer.
Correlation Investigation for Uniform Circular Array Based on Measured Massive MIMO
Authors: Lu Yanping , Tao Cheng , Liu Liu
Published: March 2019

In this paper, the performance of a two-dimensional (2D) Massive MIMO angle parameter system with a uniform circular array (UCA) topology at base station is studied based on the field measurements in indoor line-of-sight (LOS) scenario at a frequency of 4.45[Formula: see text]GHz. Many spatial parameters are extracted, including angle information and correlation characteristic. It is shown that correlation lies between antenna elements and users. It is illustrated in the envelope correlation coefficient which goes on a downward trend while the antenna spacing is increasing in the measurements.
Normally Bypassed Cascaded Sources Multilevel Inverter with RGA Optimization for Reduced Output Distortion and Formulaic Passive Filter Design
Authors: Chitrakala G. , Stalin N. , Mohan V.
Published: March 2019

The distributed generation involving multiple photovoltaic sources and synthesizing high-quality ac voltage from those multiple dc sources are nascent research ambits. A host of multilevel inverters (MLIs) has been ascertained for performing above errand diligently, where the component count is obnoxious. The single phase seven-level inverter is an acquiescent compromise between the circuit complexity and the quality of the output. Further enhancement on the performance can be succored through optimizing dc link voltages and switching angles. This paper proposes a component count pruned MLI structure and also a refined genetic algorithm (RGA)-based optimization scheme for the computation of both dc link voltages and switching angles. Previous attempts for this problem have solved the switching angles with the objective of resulting minimum harmonic content in the staircase-shaped output voltage. The dc link voltage of each level is however assumed to be the same and constant. As an extension, RGA-based optimization of both dc link voltages and switching angles is triumphed. The harmonic profile of the proposed switching strategy is simulated and also corroborated by a hardware prototype. In practice, the proposed fundamental switched strategy is apposite, in which each dc voltage can be self-maintained and independently controlled. In addition, a method for designing the passive LC filter is also presented.
A High Precision Output Impedance Calibration Technique for SST Transmitter
Authors: Bai Xu , Zhao Jianzhong , Zhou Yumei
Published: March 2019

This paper presents a high precision output impedance calibration technique for source-series terminated (SST) transmitter. Unlike the conventional impedance calibration technique using a digital method, the proposed impedance calibration employs the analog method to implement the impedance calibration. Therefore, there is no trade-off between area overhead and precision of calibration. The proposed analog impedance calibration circuit has three analog impedance control loops, namely, pull-up loop, pull-down loop and shunt-loop. Each loop is composed of a high gain amplifier and a slice-based unit. To reduce the hardware, the shunt loop utilized a slice unit replication design to achieve the shunt-slice calibration. These loops send output voltage to the SST transmitter when they reached stability. Fabricated in 55[Formula: see text]nm CMOS technology, the power consumption of the calibration circuit is 1.35[Formula: see text]mW and the total area is 61[Formula: see text][Formula: see text]m*83.1[Formula: see text][Formula: see text]m, which consumes 6.3% of the total power consumed by the transmitter and occupies 25% of the total area occupied by the complete transmitter. The post-layout simulation result shows that the maximum impedance calibration error of the three loops is less than 0.02%.
The fundamental groups of Galois covers of planar Zappatic deformations of type Ek
Authors: Amram Meirav , Gong Cheng , Tan Sheng-Li , Teicher Mina , Xu Wan-Yuan
Published: March 2019

In this paper, we investigate the fundamental groups of Galois covers of planar Zappatic deformations of type [Formula: see text]. Using Moishezon–Teicher’s algorithm, we prove that the Galois covers of the generic fiber of planar Zappatic deformations of type [Formula: see text] [Formula: see text] are simply-connected; we also compute their Chern numbers.
Ernest Henley and the shape of baryons
Authors: Buchmann Alfons J.
Published: March 2019

Calculations of pion–baryon couplings, baryon quadrupole and octupole moments, baryon spin and orbital angular momentum done in collaboration with Ernest Henley are reviewed. A common theme of this work is the shape of baryons. Also, a personal account of my work with Ernest Henley during the period 1999–2013 is given.
Asymptotics of Gaussian integrals in infinite dimensions
Authors: Albeverio Sergio , Steblovskaya Victoria
Published: March 2019

We introduce an infinite-dimensional version of the classical Laplace method, in its original form, relative to a canonical Gaussian measure associated with a Hilbert space, and for a general phase function. Particular attention is given to the case of a phase function with finite-dimensional degeneracy. Explicit results on expansions in the form of power series in the relevant parameter, with estimates on remainders, are provided.
A Multiscale Framework for Designing High-Toughness Composite Materials
Authors: Li Yan
Published: March 2019

Development of high-toughness composite materials requires careful microstructure design as geometric distribution of phases, constituent properties and interface attributes combine to influence the deformation and failure behavior of composites. In two-phase composite materials, reinforcement cracking and interface debonding are two competing fracture mechanisms observed during the crack–microstructure interactions. The activation of each fracture mechanism largely depends on the microstructure and ultimately determines the fracture toughness of composites. The objective of this study is to quantify the competition of the two fracture mechanisms as function of microstructure and find their intricate coupling with material fracture toughness. The multiscale material design framework developed here allows fracture toughness to be predicted through cohesive element-based fracture simulation and digital image correlation measurement. Based on the numerical and experimental results, two analytical models are developed for fracture mode determination of both brittle and ductile composites. Although calculations carried out concern ceramic composites Al2O3/SiC and metal matrix composites Al/SiC, the approach developed can be applied to other composite material systems.
Universal thermodynamics in inhomogeneous FLRW-type model: Thermal equilibrium
Authors: Bhandari Pritikana , Chakraborty Subenoy
Published: March 2019

A study of the universal thermodynamics has been done for the inhomogeneous Friedmann–Lemaitre–Robertson–Walker type (FLRW-type) space-time model. Validity of the generalized second law of thermodynamics has been examined across an arbitrary horizon and integrability condition for the generalized Gibbs equation has been determined. Also, the conditions for thermodynamical equilibrium have been presented in a tabular form. Finally, using unified first law, the corrected Bekenstein entropy has been evaluated for both apparent and event horizons.
Solution of fractional oscillator equations using ultraspherical wavelets
Authors: Shah Firdous A. , Abass Rustam
Published: March 2019

Fractional oscillator type equations are well-known model equations to describe several phenomenon in mathematical physics, engineering and biology. In this paper, a new method incorporated by the ultraspherical wavelet operational matrix of general order integration and block-pulse functions are adopted to investigate the solution of fractional oscillator type equations. To facilitate this, the ultraspherical wavelets are first presented and the corresponding operational matrix of fractional-order integration is derived by virtue of block pulse functions. The properties of ultraspherical wavelets and block pulse functions are used to transform the underlying problem to a system of algebraic equations which can be easily solved by any of the usual numerical methods. The efficiency and accuracy of the proposed method is demonstrated by presenting several benchmark test problems. Moreover, special attention is given to the comparison of the numerical results obtained by the new algorithm with those found by other known methods.
On a new modified fractional analysis of Nagumo equation
Authors: Saad Khaled M. , Deni̇z Si̇nan , Baleanu Dumi̇tru
Published: March 2019

In this work, a new modified fractional form of the Nagumo equation has been presented and deeply analyzed. Using the Caputo–Fabrizio and Atangana–Baleanu time-fractional derivatives, classical Nagumo model is transformed to a new fractional version. The modified equation has been solved by using the homotopy analysis transform method. The convergence analysis has been also examined with the help of the so-called [Formula: see text]-curves and average residual error. Comparing the obtained approximate solution with the exact solution leaves no doubt believing that the proposed technique is very efficient and converges toward the exact solution very rapidly.
Global dynamics in a heroin epidemic model with different conscious stages and two distributed delays
Authors: Abdurahman Xamxinur , Teng Zhidong , Zhang Ling
Published: March 2019

A heroin epidemic model with different conscious stages and distributed delays is constructed. The model allows for conscious drug users and unconscious drug users. The threshold dynamics of the model is established. It is shown that drug-free equilibrium is globally asymptotically stable when basic reproduction number [Formula: see text]; when [Formula: see text], the uniform persistence of the model is proved, and it is proved that the endemic equilibrium is globally asymptotically stable.
Photodynamic diagnostics of early gastric cancer: Complexity measures of gastric microcirculation and new model of metastatic adenocarcinoma of rat stomach
Authors: Pavlov Alexey , Borisova Ekaterina , Pavlova Olga , Agranovich Ilana , Khorovodov Alexander , Terskov Andrey , Mamedova Aysel , Klimova Maria , Avramov Latchezar , Semyachkina-Glushkovskaya Oxana
Published: March 2019

The detection of early gastric cancer that often develops asymptomatically is crucial for improving patient survival. The photodynamic diagnosis (PDD) of gastric cancer using 5-aminolevulinic acid/protoporphyrin IX (5-ALA/PpIX) has been reported in several studies. However, the selectivity of PDD of gastric tumor is poor with often false-positive results that require the development of new methods to improve PDD for early gastric cancer. Therefore, a measure of the complexity of gastric microcirculation (multi-scale entropy, MSE) and the detrended fluctuation analysis (DFA) were applied as additional tools to detect early gastric cancer in rats.In this experimental study, we used our original model of metastatic adenocarcinoma in the stomach of a rat. To induce a gastric tumor, we used a long-term combination (for 9 months, which is 1/2 of the life of rats) of two natural factors, such as chronic stress (overpopulation being typical for modern cities) and the daily presence of nitrites in food and drinks, which are common ingredients added to processed meat and fish to help preserve food.

Our results clearly show that both methods, namely, PDD using 5-ALA/PpIX and complexity/correlation analysis, can detect early gastric cancer, which was confirmed by histological analysis. Pre-cancerous areas in the stomach were detected as an intermediate fluorescent signal or MSE level between normal and malignant lesions of the stomach. However, in some cases, PDD with 5-ALA/PpIX produced a false-positive fluorescence of exogenous fluorophores due to its accumulation in benign and inflammatory areas of the mucosa. This fact indicates that the PDD itself is not sufficient for the correct diagnosis of gastric cancer, and the use of additional characteristics, e.g., complexity measures or scaling exponents, can significantly improve the diagnostic accuracy of PDD of gastric cancer that should be confirmed in further clinical studies and applications.
Formation Control of Swarm Robots Using Mobile Agents
Authors: Kambayashi Yasushi , Yajima Hideaki , Shyoji Tadashi , Oikawa Ryotaro , Takimoto Munehiro
Published: March 2019

In this paper, we propose an algorithm for controlling a fleet of swarm robots that construct three-dimensional forms. The swarm robots coordinate with each other through network communication, and compose formations such as polyhedrons presented as spherical coordinates. Our control algorithm achieves communication through mobile software agents, which introduce control programs to robots that initially have no information about the formation. Mobile software agents are autonomous objects that can migrate from one robot to other robots through a communication network and can deliver control programs as they are needed. We have made our swarm robot system to mimic the behaviors of the leafcutter ants. A leafcutter ant is a typical social insect and uses pheromone for communication. In our robot control system, we have implemented ants and pheromones as mobile software agents. We call the mobile software agents that drive the mobile robots as ant agents, and call the other agents that provide communication as pheromone agents. The ant agents drive the swarm robots to locations identified by the pheromone agents. Each ant agent has only partial information. There is no need for either a central control or an agent that has the entire design of the formation. In order to diffuse the partial information among the neighboring robots, each ant agent generates pheromone agents and dispatches them to the surrounding robots. Dispatched pheromone agent looks for a proper ant agent to influence towards a desired relative location. It is the ant agent that actually drives the robot by following the guidance of the pheromone agent, and the collective actions of ant agents and pheromone agents achieve the composition of the objective formation. We have implemented a simulator based on our algorithm and conducted numerical experiments. The results demonstrate that our mobile robot control system is feasible and efficient in practice in practical situations.
Grating Alignment for the Water Recovery X-Ray Rocket (WRXR)
Authors: Tutt James H. , McEntaffer Randall L. , Miles Drew M. , Donovan Benjamin D. , Hillman Christopher
Published: March 2019

High-resolution, high-throughput soft X-ray spectroscopy using reflection gratings has the potential to unlock answers to many of the questions about the high-energy Universe. To enable missions to use this technology in the future, the ability to precisely align reflection gratings needs to be demonstrated. The Water Recovery X-ray Rocket (WRXR), a soft X-ray spectrometer that successfully launched in April 2018 from the Kwajalein Atoll, required co-aligned X-ray reflection gratings. WRXR was designed to produce a moderate-resolution spectrum of the Vela supernova remnant over a large field-of-view. The grating module was manufactured, integrated onto the rocket payload, passed environmental testing and was successfully launched and recovered. This paper describes the grating and mirror alignment methodologies for WRXR, and their inherent systematic uncertainties. Improvements to the alignment method that are required to meet the tighter alignment tolerances of future X-ray spectrometers are also discussed.
Research on Institutional Innovation of China’s Green Insurance Investment
Authors: Chen Haitao , Yao Meifang , Chong Dazhi
Published: March 2019

Carrying out green insurance investment is of great significance for improving the green financial service system, expanding the investment space for insurance funds, improving the ability of insurance fund service ecological environment construction, and promoting the transformation of China’s economy towards a green and low-carbon sustainable development. In recent years, China’s green finance has made great progress, but its scale is only a drop in the ocean compared with the huge demand for green investment. In particular, the scale and influence of green insurance investment is small, and the role played by it is not obvious. In terms of the system, top-level design and promotion are not sufficient, and the insurance asset management institutions are less active and innovative. Therefore, it is recommended to start from the institutional innovation of green insurance investment, strengthen policy promotion and build an efficient examination and approval registration and inspection and assessment system. Also, giving full play to the role of industry infrastructure, improving the liquidity of green insurance investment projects, effectively stimulating the internal motivation of insurance institutions will promote the steady development of China’s green insurance investment.
Intertwined Vestigial Order in Quantum Materials: Nematicity and Beyond
Authors: Fernandes Rafael M. , Orth Peter P. , Schmalian Jörg
Published: March 2019

A hallmark of the phase diagrams of quantum materials is the existence of multiple electronic ordered states, which, in many cases, are not independent competing phases, but instead display a complex intertwinement. In this review, we focus on a particular realization of intertwined orders: a primary phase characterized by a multi-component order parameter and a fluctuation-driven vestigial phase characterized by a composite order parameter. This concept has been widely employed to elucidate nematicity in iron-based and cuprate superconductors. Here we present a group-theoretical framework that extends this notion to a variety of phases, providing a classification of vestigial orders of unconventional superconductors and density waves. Electronic states with scalar and vector chiral order, spin-nematic order, Ising-nematic order, time-reversal symmetry-breaking order, and algebraic vestigial order emerge from one underlying principle. The formalism provides a framework to understand the complexity of quantum materials based on symmetry, largely without resorting to microscopic models.
Development and Validation of UV-Visible Spectrophotometric Method for the Determination of 5-Hydroxymethyl Furfural Content in Canned Malt Drinks and Fruit Juices in Ghana
Authors: Adu Joseph K. , Amengor Cedric D. K. , Orman Emmanuel , Ibrahim Nurudeen Mohammed , Ifunanya Maryjane O. , Arthur Dylan F.
Published: March 2019

A simple, rapid, accurate, and less expensive spectrophotometric method has been developed for the quantitation of 5-hydroxymethyl furfural (5-HMF) levels in canned malt drinks and fruit juice drinks sampled in the Kumasi Metropolis, Ghana. The quantitation is based on the selective maximum absorption of ultraviolet radiation by 5-HMF at the wavelength (λmax) of 284 nm using acetonitrile : water (50 : 50 v/v) as the solvent system. The method was established to be specific, precise, and accurate over a concentration range of 0.001 mg/ml–0.02 mg/ml. 5-HMF levels in fruit juice samples (A1–A10) were between 0.132 mg/ml and 0.438 mg/ml, and these levels were shown to be comparable (t = 2.200;p=0.0553) to the contents in the canned malt samples (M1–M10) which were between 0.3140 mg/ml and 0.7170 mg/ml. The study failed to show any dependence of 5-HMF levels on the composition of the product as well as the manufacturing process adopted. The length of storage did also not significantly affect the 5-HMF levels in the products.
The Unanticipated Catalytic Activity of Lithium tert-Butoxide/THF in the Interesterification of Rapeseed Oil with Methyl Acetate
Authors: Kampars Valdis , Abelniece Zane , Blaua Sabine
Published: March 2019

Conventionally, the biodiesel (mixture of fatty acid methyl esters, FAME) production proceeds by transesterification of triglycerides with methanol accordingly by the formation of glycerol as a by-product, which cannot be included in biofuel composition. Biodiesel could also be produced via interesterification ensuring full conversion of oil to biofuel, consisting of FAME and triacetin. The most effective catalysts for interesterification reactions are alkali metal alkoxides. The effectivity of alkoxide catalyst depends on its solubility determined by the structure of the alkyl chain. In our previous studies, we have shown that the branched chain catalyst tert-BuOK/THF is highly suitable for the realisation of interesterification reactions. Till now, in the scientific literature, very little is known about the influence of metal ions. In order to investigate the influence of counterion on the activity of alkoxide catalysts, in this work, we have investigated the proceeding of interesterification reactions of rapeseed oil with methyl acetate in the presence of lithium, sodium, and potassium tert-butoxides in THF. Experimentally obtained relationships for catalyst-to-oil molar ratio (COMR) influence rapeseed oil interesterifications with methyl acetate at 55°C for 1 h, with methyl acetate-to-oil molar ratio (MAOMR) 18 showing that the tert-BuONa/THF and tert-BuOK/THF have high and similar activity, but the tert-BuOLi/THF is fundamentally different. The low and diverse activity of lithium tert-butoxide can be explained by the association of ions and very low catalytic activity of ion pairs. Simulation of the influence of association on the FAME formation shows that at COMR 0.1 (sufficient for fast reaction proceeding in the presence of tert-BuONa/THF and tert-BuOK/THF), the concentration of tert-butoxide ions in the presence of tert-BuOLi/THF because of associations lowers from 28 mmol/L to 13 mmol/L, whcih is not sufficient for effective proceeding of reaction. Activity of alkoxides in this reaction is solely determined by the counterion.