bluuebunny/crossref_metadata_2025 huggingface dataset:
Mothers' distress exposure and children's withdrawn behavior – A moderating role for the Interferon Gamma gene (IFNG)
Authors: Pinto Raquel , Belsky Jay , Baptista Joana , Carvalho Agostinho , Cunha Cristina , Soares Isabel , Mesquita Ana R.
Published: February 2020

The dysregulation of the inflammatory response, including pro‐inflammatory molecules, produces neuropsychiatric symptoms and depression‐like behavior, including withdrawal from the physical and social environment. Genetic variants that enhance immune reactivity may thus increase inflammatory and withdrawn reactions to stress. Here we investigated a functional polymorphism of Interferon Gamma gene (IFNG +874 T > A, rs2430561) as moderator of the relationship between mothers’ distress exposure and children's withdrawn behavior at preschool age. Participants were 198 Portuguese preschool children (mean age = 57.98 months). Exposure to mother's distress was assessed using the Brief Symptom Inventory, and withdrawn behavior with the Caregiver Teacher Report Form. All children provided saliva samples for genotyping. Contrary to expecations based on prior work, the rs2430561 AA genotype—not the T variant—interacted with (high levels of) mothers’ distress exposure, to increase children's withdrawn behavior. No significant main effects were detected. The polymorphism in Interferon Gamma gene showed specific environmental stressor‐dependent effects on withdrawn behavior during childhood, ones which are interpreted in light of the "behavioral immune system" hypothesis, and which proved inconsistent with diathesis‐stress thinking.
Temperament in preadolescence is associated with weight and eating pathology in young adulthood
Authors: van Eeden Annelies E. , Hoek Hans W. , van Hoeken Daphne , Deen Mathijs , Oldehinkel Albertine J.
Published: February 2020

Objective

Few longitudinal studies have investigated the role of temperament traits on weight and eating problems thus far. We investigated whether temperament in preadolescence influences body weight and the development of eating pathology in adolescence and young adulthood.

Method

This study used data from TRAILS (Tracking Adolescents' Individual Lives Survey), a Dutch community cohort study (N = 2,230) from preadolescence into adulthood. At age 11, the temperament dimensions negative affectivity and effortful control were measured with the Early Adolescent Temperament Questionnaire‐Revised. Body mass index (BMI) was measured at all assessment waves. At age 19, the prevalence of eating disorders was investigated by two‐stage screening including interviews by eating disorder experts. At age 22 and 26, the Eating Disorder Diagnostic Scale was used to assess the level of eating pathology.

Results

Higher negative affectivity in preadolescence was associated with higher BMI and eating pathology in young adulthood. Lower effortful control in preadolescence was found to be a risk factor for the development of obesity in young adulthood. No association was found between effortful control in preadolescence and eating pathology in later life.

Discussion

Both negative affectivity and effortful control play a role in the development of weight or eating problems during adolescence.
Improvement of germinated brown rice quality with autoclaving treatment
Authors: Ren Chuanying , Hong Bin , Zheng Xianzhe , Wang Liqun , Zhang Yinglei , Guan Lijun , Yao Xinmiao , Huang Wengong , Zhou Ye , Lu Shuwen
Published: February 2020

Germinated brown rice (GBR) is a popular functional food containing considerable amounts of beneficial nutrients and bioactive compounds. Here, autoclaving at 115°C for 20 min was employed to process GBR (AGBR) to evaluate the effect of autoclaving on the nutritional and health function of GBR in microstructure, taste value, aroma, as well as the physiological ingredients. The results showed that autoclaving treatment influenced the starch gelatinization and aroma to improve the taste of cooked AGBR. Autoclaving treatment significantly increased the gamma‐aminobutyric acid (GABA) and ferulic acid levels of AGBR (p < .05). In addition, consuming AGBR for 1 month significantly decreased the fasting plasma glucose (FPG), 0.5, 1, and 2 hr postprandial plasma glucose (PPG), triglyceride (TG), total cholesterol (TC), high‐density lipoprotein cholesterol (HDL‐c), and low‐density lipoprotein cholesterol (LDL‐c) in metabolic syndrome (MS) patients (p < .05). Therefore, autoclaving treatment, as a promising processing strategy, may both improve the sensory attributes and the nutrition of GBR.
The intellectual disability protein Oligophrenin‐1 controls astrocyte morphology and migration
Authors: Pillet Laure‐Elise , Cresto Noémie , Saillour Yoann , Ghézali Grégory , Bemelmans Alexis‐Pierre , Livet Jean , Bienvenu Thierry , Rouach Nathalie , Billuart Pierre
Published: February 2020

Astrocytes are involved in several aspects of neuronal development and properties which are altered in intellectual disability (ID). Oligophrenin‐1 is a RhoGAP protein implicated in actin cytoskeleton regulation, and whose mutations are associated with X‐linked ID. Oligophrenin‐1 is expressed in neurons, where its functions have been widely reported at the synapse, as well as in glial cells. However, its roles in astrocytes are still largely unexplored. Using in vitro and in vivo models of oligophrenin1 disruption in astrocytes, we found that oligophrenin1 regulates at the molecular level the RhoA/ROCK/MLC2 pathway in astroglial cells. We also showed at the cellular level that oligophrenin1 modulates astrocyte morphology and migration both in vitro and in vivo, and is involved in glial scar formation. Altogether, these data suggest that oligophrenin1 deficiency alters not only neuronal but also astrocytic functions, which might contribute to the development of ID.
Effects of isolated or combined exposure to sibutramine and rosuvastatin on reproductive parameters of adult male rats
Authors: e Silva Patrícia Villela , Borges Cibele dos Santos , Rosa Josiane de Lima , Pacheco Tainá Louise , Figueiredo Thamiris Moreira , Leite Gabriel Adan Araújo , Guerra Marina Trevizan , Anselmo‐Franci Janete Aparecida , Klinefelter Gary Robert , Kempinas Wilma De Grava
Published: February 2020

Many obese patients are exposed to hypolipidemic and serotonin‐norepinephrine reuptake inhibitor (SNRI) drugs. Statins are one of the most marketed drugs in the world to treat dyslipidemia, while sibutramine, a SNRI drug, is prescribed in some countries to treat obesity and is detected as an additive in many adulterated weight loss supplements marketed worldwide. Previous studies reported adverse effects of isolated exposure to these drugs on male rat reproductive parameters. In the present work, we further investigated male reproductive toxicity of these drugs, administered in isolation or combination in adult rats for a longer period of treatment. Adult male rats (90 days) were treated (gavage) for 70 days with saline and dimethyl sulfoxide (control), sibutramine (10 mg/kg), rosuvastatin (5 mg/kg), or rosuvastatin combined with sibutramine. Sibutramine alone or with rosuvastatin, promoted a reduction in food intake and body weight gain, weight of the epididymis, ventral prostate and seminal vesicle; as well as decreased sperm reserves and transit time through the epididymis; androgen depletion; and increased index of cytoplasmic droplet. The rosuvastatin‐treated group showed reduced frequency of ejaculation. Exposure to this drug alone or combined with sibutramine impaired epididymal morphology. Co‐exposed rats had altered epididymal morphometry, and seminal vesicle and testis weights. The rats also showed decreased fertility after natural mating and a trend toward a delay in ejaculation, suggesting a small synergistic effect of these drugs. Given the greater reproductive efficiency of rodents, the results obtained in the present study raise concern regarding possible fertility impairment in men taking statins and SNRI drugs.
Cascade substitution reaction between oxabornene and amines to construct cyclohexa‐1,4‐diene‐3,6‐diamine and amino alcohol
Authors: Zhao Changkuo , Wang Xianheng , Xu Lang , Cao Ying , Cui Hanqi , Wang Yuhe
Published: February 2020

In competition with Michael addition between oxabornene and amines, a cascade substitution reaction predominates to generate cyclohexa‐1,4‐diene‐3,6‐diamine and amino alcohol in a moderate yield. This method has wide universality for different amines, overcomes the shortcomings of Michael addition reaction that cannot be synthesized due to shortage of raw materials, and can be further applied to the total synthesis of some related natural products.
Determination of HIV status and identification of incident HIV infections in a large, community‐randomized trial: HPTN 071 (PopART)
Authors: Eshleman Susan H , Piwowar‐Manning Estelle , Wilson Ethan A , Lennon Denni , Fogel Jessica M , Agyei Yaw , Sullivan Philip A , Weng Lei , Moore Ayana , Laeyendecker Oliver , Kosloff Barry , Bwalya Justin , Maarman Gerald , van Deventer Anneen , Floyd Sian , Bock Peter , Ayles Helen , Fidler Sarah , Hayes Richard , Donnell Deborah ,   for the HPTN 071 (PopART) Study Team
Published: February 2020

Introduction

The HPTN 071 (PopART) trial evaluated the impact of an HIV combination prevention package that included “universal testing and treatment” on HIV incidence in 21 communities in Zambia and South Africa during 2013‐2018. The primary study endpoint was based on the results of laboratory‐based HIV testing for> 48,000 participants who were followed for up to three years. This report evaluated the performance of HIV assays and algorithms used to determine HIV status and identify incident HIV infections in HPTN 071, and assessed the impact of errors on HIV incidence estimates.

Methods

HIV status was determined using a streamlined, algorithmic approach. A single HIV screening test was performed at centralized laboratories in Zambia and South Africa (all participants, all visits). Additional testing was performed at the HPTN Laboratory Center using antigen/antibody screening tests, a discriminatory test and an HIV RNA test. This testing was performed to investigate cases with discordant test results and confirm incident HIV infections.

Results

HIV testing identified 978 seroconverter cases. This included 28 cases where the participant had acute HIV infection at the first HIV‐positive visit. Investigations of cases with discordant test results identified cases where there was a participant or sample error (mixups). Seroreverter cases (errors where status changed from HIV infected to HIV uninfected, 0.4% of all cases) were excluded from the primary endpoint analysis. Statistical analysis demonstrated that exclusion of those cases improved the accuracy of HIV incidence estimates.

Conclusions

This report demonstrates that the streamlined, algorithmic approach effectively identified HIV infections in this large cluster‐randomized trial. Longitudinal HIV testing (all participants, all visits) and quality control testing provided useful data on the frequency of errors and provided more accurate data for HIV incidence estimates.
Longitudinal in vivo monitoring of callus remodeling in BMP‐7‐ and Zoledronate‐treated fractures
Authors: Mathavan Neashan , Raina Deepak Bushan , Tägil Magnus , Isaksson Hanna
Published: February 2020

Pharmacological interventions that combine pro‐anabolic and anti‐catabolic drugs to treat recalcitrant fractures have shown remarkable efficacy in augmenting the regenerative response. Specifically, in rodent models of fracture repair, treatment with BMP‐7 and Zoledronate (ZA) has almost uniformally resulted in complete union. However, delayed remodeling may be problematic for ZA‐treated fractures. The increase in newly formed bone is substantial but if translated in humans, delayed remodeling may delay functional recovery. Our objective was to determine if, and to what extent, bone morphogenetic protein (BMP) (in synergistically administered BMP‐7 + ZA) can modulate the delayed hard callus remodeling caused by ZA. Callus remodeling in BMP‐7‐only and BMP‐7 + ZA‐treated osteotomies were monitored using in vivo µCT to follow the progression of healing at 6‐week intervals over 24 weeks in an open femoral fracture rat model. None of the groups recovered baseline cortical bone volumes within 24 weeks post‐osteotomy. Treatment prolonged the remodeling phase but the kinetics of remodeling appeared to differ between BMP and BMP + ZA groups. However, the mechanical characteristics were largely restored. Callus/bone volumes in BMP‐only treated fractures peaked as early as week 3 suggesting that remodeling is stimulated prematurely. However, this rate of remodeling was not maintained as BMP‐7 was found to exhibit negligible changes in callus/bone volumes between weeks 6 and 18, whereas declines in callus/bone volumes were present at these time points in the BMP‐7 + ZA group. Our findings suggest that inclusion of ZA as an anti‐catabolic agent may not be detrimental to the regenerative process despite a prolonged remodeling phase.
Biosurfactants Production Using Permeate from Whey Ultrafiltration and Bioproduct Recovery by Membrane Separation Process
Authors: Decesaro Andressa , Machado Thaís Strieder , Cappellaro Ângela Carolina , Rempel Alan , Margarites Ana Cláudia , Reinehr Christian Oliveira , Eberlin Marcos Nogueira , Zampieri Davila , Thomé Antônio , Colla Luciane Maria
Published: February 2020

The management of whey is a challenge for dairy products where the volume produced is remarkable. This problem is minimized through membrane separation processes (MSP) to obtain whey protein concentrate, which has high added value. However, a permeate effluent stream is still generated that is composed of lactose, vitamins, and minerals, which can serve as raw material for the production of biotechnological compounds. Thus, this study aimed to produce biosurfactants using the permeate from whey ultrafiltration as part of the culture media of the bioprocess, to recover the biosurfactant produced using MSP, and to identify the biocompound. The production was carried out using Bacillus methylotrophicus and Bacillus pumilus. The variables nitrogen source (urea or ammonium sulfate), nitrogen source concentration (0.5% or 1.0%), inducer (soybean oil or biodiesel), inducer concentration (1% or 2%), and the addition of micronutrients (with our without) were studied using a fractional factorial experimental design 25‐1IV. In the fermentation processes, it was possible to verify the biosurfactant production through the reduction of surface tension, obtaining a minimum value of 35.07 mN/m for B. methylotrophicus and 26.02 mN/m for B. pumilus. Recovery via MSP was an efficient strategy for biosurfactant purification, which was concentrated in the fraction of the retentate. We produced a high‐value‐added biocompound identified as surfactin, valuing the permeate residue from whey ultrafiltration.
High‐throughput determination of fungicides in grapes using thin‐film microextraction coupled with liquid chromatography–tandem mass spectrometry
Authors: Zhang Zong‐hui , Zhao Hui‐yu , Shen Qian , Qi Pei‐pei , Wang Xin‐quan , Xu Hao , Di Shan‐shan , Wang Zhi‐wei
Published: February 2020

A high‐throughput and environmentally friendly method based on 96‐well plate thin‐film microextraction was established to determine 14 fungicides in grapes and grape juice using liquid chromatography–tandem mass spectrometry. The thin‐film microextraction optimized method consisted of 60 min of extraction at pH 6.0 with the addition of sodium chloride (2–5%). Acetonitrile/water in the ratio of 8:2 was used for desorption analytes for 60 min. Evaluation of different extractive phases showed that polyacrylonitrile–polystyrene–divinylbenzene was the optimum coating. The linearity of the method was good in the range of 0.01–0.5 μg/mL for 14 fungicides with determination coefficients (R2) from 0.990 to 0.999, which indicated good linearity for both the grape juice and grape matrixes. The limit of detection was in the range of 0.002–0.01 μg/mL. The limit of quantitation was in the range of 0.01 mg/kg according to the minimum fortified level. The average absolute recoveries of the 14 fungicides ranged from 75.0 to 118.3%. The intraday relative standard deviation (n = 4) and interday relative standard deviation (n = 4) were 5.6–13.0% and 1.6–6.4%, respectively. This study showed that this method can be used for analyzing 96 samples in parallel, and the sample preparation time was approximately 2.0 min per sample. In addition, this approach offers a green and low‐cost sample pretreatment technique for future analyses.
Untargeted metabolomic study on the insomnia effect of Suan‐Zao‐Ren decoction in the rat serum and brain using ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry combined with data processing analysis
Authors: Du Yiyang , Wu Bo , Xiao Feng , Yan Tingxu , Li Qing , Jia Ying , Bi Kaishun , He Bosai
Published: February 2020

Insomnia is a common clinical disease that can seriously damage the normal lives of sufferers. Suan‐Zao‐Ren decoction has been used to treat insomnia for a long time. However, the underlying molecular mechanism of Suan‐Zao‐Ren decoction is still not clear. In this study, the nontargeted metabolomics based on high‐resolution mass spectrometry and multiple statistical approaches were initially used to investigate the changes of potential serum and brain biomarkers and metabolic pathways in the insomnia model rat. Principal component analysis‐discriminate analysis indicated that the Suan‐Zao‐Ren decoction treatment improved the metabolic phenotype insomnia. Moreover, the heatmap analysis identified the most important biomarkers involved in insomnia. According to the pathway analysis, phenylalanine metabolism, tryptophan metabolism, and so on were recognized as the most affected metabolic pathways associated with insomnia disease. These findings provided a comprehensive understanding of the regulative effects of Suan‐Zao‐Ren decoction on the host metabolic phenotype of the insomnia rats. Our work demonstrated that the metabolomics approach is a promising tool that could help us to conduct the exploration of the therapeutic effects and mechanism of traditional Chinese medicines.
Freshening of the western Arctic negates anthropogenic carbon uptake potential
Authors: Woosley Ryan J. , Millero Frank J.
Published: February 2020

As human activities increase the atmospheric concentration of carbon dioxide (CO2), the oceans are known to absorb a significant portion. The Arctic Ocean has long been considered to have enormous potential to sequester anthropogenic CO2, and mitigate emissions. The frigid waters make CO2more soluble, and as sea ice melts, greater surface area is exposed to absorb CO2. However, sparse data have made quantifying the amount of anthropogenic CO2in the Arctic difficult, stimulating much debate over the basin's contribution to CO2sequestration from the atmosphere. Using three separate cruises in 1994, 2005, and 2015 in the Canada and Makarov basins, we analyze the decadal variability in anthropogenic CO2uptake in the central western Arctic. Here we show, from direct carbon system measurements spanning two decades, that despite increased atmospheric CO2, total dissolved inorganic carbon has actually decreased, with minimal anthropogenic CO2uptake. The reduction in dissolved CO2results from a dilution of total alkalinity by increased freshwater supply, particularly river water. Changes in the freshwater budget of the western Arctic override its uptake potential, resulting in a weak sink, or possibly source of CO2.
Role of tool pin profiles on wear characteristics of friction stir processed magnesium alloy ZK60/silicon carbide surface composites
Authors: Vignesh Kumar M. , Padmanaban G. , Balasubramanian V.
Published: February 2020

Poor friction and wear resistance are the major drawbacks that restrict structural applications of ZK60 magnesium alloys. The surface properties of magnesium alloy can be enhanced by reinforcing particles in the surface using friction stir processing (FSP). Tool pin profile is the significant process parameters which influences the material flow, particle breakups and its distribution in the processed zone. In this study, an attempt was made in order to understand the major effects of tool pin profiles namely, cylindrical thread (CT), plain cylindrical (PC), plain tapered cylindrical (PTC) and square (SA) pin profiles on the microstructure characteristics and particle distribution of friction stir processed/silicon carbide particle surface composites. The surface composites fabricated by plain tapered cylindrical pin profile yield superior properties which is attributed to the higher shear force and balanced state of material flow and heat generation in the processed zone. The formation of smaller grains and hardness enhancement due to dispersion strengthening are the main causes to get better wear resistance of friction stir processed/silicon carbide particle magnesium alloy.
An algorithm for the determination of graphs associated to fold maps between closed surfaces
Authors: Romero Pantaleón D. , Coêlho Jéferson R. P. , Mendes de Jesus Catarina
Published: February 2020

The aim of this paper is to introduce a computational tool that checks theoretical conditions in order to determine whether a weighted graph, as a topological invariant of stable maps, can be associated to stable maps without cusps (ie, fold maps) from closed surfaces to the projective plan.
Triple‐wavelength Q‐switched ytterbium‐doped fiber laser based on tungsten oxide as saturable absorber
Authors: Salman Ali A. , Al‐Janabi Abdulhadi
Published: February 2020

In this article, a multiwavelength Q‐switched ytterbium‐doped fiber laser using tungsten oxide nanoparticles (WO3 NPs) as a saturable absorber (SA) is reported for the first time. The SA was prepared by depositing micron‐sized layers of WO3 NPs suspension onto the surface of the fiber tip via direct deposition process. After embedding the SA into an ytterbium‐doped fiber laser cavity, self‐starting Q‐switched performance was realized at a bleaching threshold of 179 mW having a minimum pulse width of 2.92 μs and maximum pulse energy of 9.26 nJ with variable repetition rates from 14.8 to 71.3 kHz. By boosting the pump power and proper adjustment of the polarization controller, steady dual‐ and triple‐wavelength operations were obtained at pump powers of 210 and 275 mW, respectively. The obtained results confirm the practical use of WO3 as an effective nonlinear modulator for multiwavelength and pulsed fiber lasers near 1 μm wavelength band.
Impact of angle of attack on plasma flow and electromagnetic wave propagation around hypersonic vehicles
Authors: Ouyang Wenchong , Liu Yanming , Zhang Xu
Published: February 2020

The flow field around the RAMC‐II vehicle at differenrt angles of attack (AOA) was numerically solved using a computational fluid dynamics technique with a three‐dimensional model. Electron density, pressure, temperature, and collision frequency, which is given great importance in this paper. The maximal electron density, total pressure, and temperature at the same position decreases with the angle of attack on the leeward side and increases with the angle of attack on the windward side. The collision frequency is almost unaffected by AOA on the leeward side, but increases significantly with AOA on the windward side. Based on the realistic plasma sheaths obtained by hypersonic fluid model, a multilayer transmission model was used to study the electromagnetic (EM) wave propagation in plasma sheath at different AOA. The attenuation value of EM wave on the leeward (windward) side decreases (increases) with the AOA. So the influence of the AOA on the EM wave transmission must be considered in the communication of vehicle reentry. In addition, the EM wave attenuation on the leeward at the same angle of attack is always smaller than the windward side, especially at a large AOA. Therefore, the leeward side can be considered as one end of the communication to improve the communication quality. The conclusions of this paper have both theoretical and practical significance to better understand the communication“blackout” problem for the reentry of hypersonic vehicles.
Improvement of unidirectional scattering characteristics based on multiple nanospheres array
Authors: Jiang Li , Fang Bo , Yan Zhigang , Li Chenxia , Fu Jipeng , Gan Haiyong , Hong Zhi , Jing Xufeng
Published: February 2020

All dielectric nanospheres with low loss and ultra‐compact characteristics can be effectively applied in nanophotonics in the visible and infrared ranges. The unidirectional forward scattering with azimuthally symmetry can be achieved by simple dielectric nanosphere. The physical origin of this directionality can be attributed to the interference effect of electric and magnetic resonances induced in nanoshperes. For the forward scattering of a single nanosphere the spectrally overlapping resonance of electric and magnetic quadrupoles can further enhance the directionality and magnitude of unidirectional forward scattering. For a nanosphere homodimers, the scattering pattern can also preserve the azimuthal asymmetry and the suppression of backscattering. But, the side scattering lobes occur due to the grating diffraction effect. Furthermore, the significant improvement of scattering magnitude and directionality can be achieved by a linear chain of nanospheres. These unique optical scattering of nanoshperes can be applied in the fields of nanoantennas, photovoltaics, and nanolasers in visible and near infrared ranges.
A mathematical expression for depth‐light curves of therapeutic proton beams in a quenching scintillator
Authors: Kelleter Laurent , Jolly Simon
Published: February 2020

Purpose

Recently, there has been increasing interest in the development of scintillator‐based detectors for the measurement of depth–dose curves of therapeutic proton beams (Beaulieu and Beddar [2016], Phys Med Biol., 61:R305–R343). These detectors allow the measurement of single beam parameters such as the proton range or the reconstruction of the full three‐dimensional dose distribution. Thus, scintillation detectors could play an important role in beam quality assurance, online beam monitoring, and proton imaging. However, the light output of the scintillator as a function of dose deposition is subject to quenching effects due to the high‐specific energy loss of incident protons, particularly in the Bragg peak. The aim of this work is to develop a model that describes the percent depth‐light curve in a quenching scintillator and allow the extraction of information about the beam range and the strength of the quenching.

Methods

A mathematical expression of a depth‐light curve, derived from a combination of Birks’ law (Birks [1951], Proc Phys Soc A., 64:874) and Bortfeld’s Bragg curve (Bortfeld [1997], Med Phys., 24:2024–2033) that is termed a “quenched Bragg” curve, is presented. The model is validated against simulation and measurement.

Results

A fit of the quenched Bragg model to simulated depth‐light curves in a polystyrene‐based scintillator shows good agreement between the two, with a maximum deviation of 2.5% at the Bragg peak. The differences are larger behind the Bragg peak and in the dose build‐up region. In the same simulation, the difference between the reconstructed range and the reference proton range is found to be always smaller than 0.16 mm. The comparison with measured data shows that the fitted beam range agrees with the reference range within their respective uncertainties.

Conclusions

The quenched Bragg model is, therefore, an accurate tool for the range measurement from quenched depth–dose curves. Moreover, it allows the reconstruction of the beam energy spread, the particle fluence, and the magnitude of the quenching effect from a measured depth‐light curve.
Does the magnetization transfer effect bias chemical exchange saturation transfer effects? Quantifying chemical exchange saturation transfer in the presence of magnetization transfer
Authors: Smith Alex K. , Ray Kevin J. , Larkin James R. , Craig Martin , Smith Seth A. , Chappell Michael A.
Published: February 2020

Purpose

Chemical exchange saturation transfer (CEST) is an MRI technique sensitive to the presence of low‐concentration solute protons exchanging with water. However, magnetization transfer (MT) effects also arise when large semisolid molecules interact with water, which biases CEST parameter estimates if quantitative models do not account for macromolecular effects. This study establishes under what conditions this bias is significant and demonstrates how using an appropriate model provides more accurate quantitative CEST measurements.

Methods

CEST and MT data were acquired in phantoms containing bovine serum albumin and agarose. Several quantitative CEST and MT models were used with the phantom data to demonstrate how underfitting can influence estimates of the CEST effect. CEST and MT data were acquired in healthy volunteers, and a two‐pool model was fit in vivo and in vitro, whereas removing increasing amounts of CEST data to show biases in the CEST analysis also corrupts MT parameter estimates.

Results

When all significant CEST/MT effects were included, the derived parameter estimates for each CEST/MT pool significantly correlated (P < .05) with bovine serum albumin/agarose concentration; minimal or negative correlations were found with underfitted data. Additionally, a bootstrap analysis demonstrated that significant biases occur in MT parameter estimates (P < .001) when unmodeled CEST data are included in the analysis.

Conclusions

These results indicate that current practices of simultaneously fitting both CEST and MT effects in model‐based analyses can lead to significant bias in all parameter estimates unless a sufficiently detailed model is utilized. Therefore, care must be taken when quantifying CEST and MT effects in vivo by properly modeling data to minimize these biases.
Mesoscale numerical study on the evolution of borehole breakout in heterogeneous rocks
Authors: Li Yingchun , Qu Yaodong , He Qiangyuan , Tang Chunan
Published: February 2020

Inherent heterogeneity of a rock strongly affects its mechanical behavior. We numerically study the mechanisms governing the initiation, propagation, and ultimate pattern of borehole breakouts in heterogeneous rocks. A two‐dimensional finite element model incorporating material heterogeneity is established to systematically examine the effects of several key factors on borehole failure, including borehole diameter, far‐field stress, and rock heterogeneity. The inherent heterogeneity of a rock is explicitly characterized by prescribing the rock mechanical properties of mesoscale elements statistically obeying the Weibull distribution. Elastic damage mechanics is used to represent the constitutive law of the mesoscale element. We find that borehole diameter reduction remarkably changes the crack failure from tensile to shear and elevates the critical hydrostatic pressure. Far‐field stress anisotropy strongly affects the shape of the borehole breakout. Rock heterogeneity dictates the location of the preferred crack under the hydrostatic stress, which leads to local stress concentration, and determines the types of breakouts around the borehole. Our findings facilitate in‐depth understanding of the classic borehole stability problems in heterogeneous rocks.
Linear and nonlinear topology optimization design with projection‐based ground structure method (P‐GSM)
Authors: Deng Hao , To Albert C.
Published: February 2020

A new topology optimization scheme called the projection‐based ground structure method (P‐GSM) is proposed for linear and nonlinear topology optimization designs. For linear design, compared to traditional GSM which are limited to designing slender members, the P‐GSM can effectively resolve this limitation and generate functionally graded lattice structures. For additive manufacturing‐oriented design, the manufacturing abilities are the key factors to constrain the feasible design space, for example, minimum length and geometry complexity. Conventional density‐based method, where each element works as a variable, always results in complex geometry with large number of small intricate features, while these small features are often not manufacturable even by 3D printing and lose its geometric accuracy after postprocessing. The proposed P‐GSM is an effective method for controlling geometric complexity and minimum length for optimal design, while it is capable of designing self‐supporting structures naturally. In optimization progress, some bars may be disconnected from each other (floating in the air). For buckling‐induced design, this issue becomes critical due to severe mesh distortion in the void space caused by disconnection between members, while P‐GSM has ability to overcome this issue. To demonstrate the effectiveness of proposed method, three different design problems ranging from compliance optimization to buckling‐induced mechanism design are presented and discussed in details.
Global stabilizability of an anaerobic biodegradation process via piecewise constant feedback
Authors: Borisov Milen K. , Dimitrova Neli S. , Krastanov Mikhail I.
Published: February 2020

We consider a nonlinear model of an anaerobic digestion process with methane production. We propose a stabilizing control law involving piecewise constant feedback and study the asymptotic stability of the obtained closed‐loop system. An extremum seeking algorithm is applied to maximize the output. Numerical simulation results are also presented to illustrate the theoretical investigations.
Optimal‐switched extended H∞ filter for nonlinear systems with stochastic uncertainties
Authors: Li Yuankai , Ding Liang , Jing Zhongliang
Published: February 2020

The extended H∞ filter (EH∞F) is a conservative solution with infinite‐horizon robustness for the state estimation problem regarding nonlinear systems with stochastic uncertainties, which leads to excessive costs in terms of filtering optimality and reduces the estimation precision, particularly when uncertainties related to external disturbances and noise appear intermittently. In order to restore the filtering optimality lost due to the conservativeness of the EH∞F design, we developed an optimal‐switched (OS) filtering mechanism based on the standard EH∞F to obtain an optimal‐switched extended H∞ filter (OS‐EH∞F). The OS mechanism has an error‐tolerant switched (ETS) structure, which switches the filtering mode between optimal and H∞ robust by setting a switching threshold with redundancy to uncertainties, and a robustness‐optimality cost function (ROCF) is introduced to determine the threshold and optimize the ETS structure online. The ROCF is the weighted sum of the quantified filtering robustness and optimality. When a weight is given, the proposed OS‐EH∞F can obtain the optimal state estimates while maintaining the filtering robustness at an invariant ratio. A simulation example of space target tracking has demonstrated the superior estimation performance of the OS‐EH∞F compared with some other typical filters, thereby verifying the effectiveness of using the weight to evaluate the estimation result of the filters.
Variation in soil lignin protection mechanisms in five successional gradients of mixed broadleaf–pine forests
Authors: Feng Yue , Han Shijie , Chen Wei , Gu Yue , Stewart Catherine E. , Zhang Junhui , Geng Shicong , Chen Zhijie , Setälä Heikki
Published: February 2020

Over 200 yr of ecosystem succession in northeastern China, conifers have replaced broadleaf trees. Vegetation changes during forest succession may affect soil organic C (SOC) stability, which is associated with altered protection mechanisms. Lignin phenol composition, a predictor of soil organic matter variation, was assessed for macroaggregates, microaggregates, and silt–clay (SC) fractions from successional gradients in five forests aged 19 to 239 yr in the Changbai Mountains nature reserve. The large macroaggregates (4.00–8.00 and 2.00–4.00 mm) comprised 45.17 to 59.87% of bulk dry weight and 40.22 to 60.89% of SOC in the 19‐, 32‐, and 48‐yr‐old pioneer forests. However, we detected increased mass proportions and SOC contents in small macroaggregates (1.00–2.00 and 0.25–1.00 mm) in the mixed broadleaf–Korean pine (Pinus koraiensis Siebold & Zucc.) forest after 122 yr. Lignin in bulk soil and aggregates in the 122‐yr‐old stand had lower acid/aldehyde ratios for the vanillyl and syringyl types than other stands, indicating less lignin decomposition. The highest C (198.20 g kg−1 soil) and lignin concentrations (6.14 mg 100 mg−1 C) were detected in the bulk soil from the 239‐yr‐old stand, where SC fraction occupied 56.18% of the C and 84.17% of the lignin content in bulk soil. Forest succession from broadleaf to a broadleaf–pine mixture shifted SOC sequestration and lignin protection from aggregates to SC fractions, along with the development of plant litter composition, fine‐root biomass and turnover, and microorganism biomass, which prompted effective long‐term SOC accumulation in successional forest communities.
Non‐targeted metabolomics approach to assess the brown marine macroalga Dictyota dichotoma as a functional food using liquid chromatography with mass spectrometry
Authors: Dixit Dhara , Reddy C.R.K. , Trivedi M.H. , Gadhavi Devesh K.
Published: February 2020

The study elucidates presence of 16 potential putative metabolites in Dictyota dichotoma through non‐targeted secondary metabolite profile analysis using electrospray ionization negative mode of liquid chromatography with time‐of‐flight mass spectrometry. Two fatty acyl glycosides viz; 5‐megastigmen‐7‐yne‐3,9‐diol 9‐glucoside (biomarker for food consumption) and (3S,7E,9S)‐9‐hydroxy‐4,7‐megastigmadien‐3‐one 9‐glucoside (nutrient, emulsifier, surfactant), an o‐glycosyl compound 5‐megastigmen‐7‐yne‐3,9‐diol 3‐glucoside (biomarker for food consumption), all with m/z value 370.19 were detected. An acyclic monoterpenoid and diterpenoid viz; isodigeranyl and digeranyl (both with m/z 274.26; food biomarkers) were detected. Additionally, (3′x,5′a,9′x,10′b)‐O‐(3‐hydroxy‐6‐oxo‐7‐drimen‐11‐yl) umbelliferone (m/z 396.19; nutrient, emulsifier, surfactant) and kamolonol (m/z 398.2; antibacterial, anti‐tumor) were observed. Two angular pyranocoumarins: mammea C/AB cyclo D (m/z 398.2; food consumption biomarker) and 5‐hydroxy‐8, 8‐dimethyl‐6‐(3‐methyl‐1‐oxobutyl)‐4‐pentyl‐2H,8H‐benzo[1,2‐b:3,4‐b']dipyran‐2‐one (m/z 398.2; fruit constituent) were present. Two terpene lactones ‐ galbanic acid (m/z 398.2; antimicrobial, anticoagulant, antiviral, anti‐inflammatory, anti‐cancer) and asacoumarin A (m/z 398.2; antiprotozoal, antiglycation activity) were detected. Armillaribin (m/z 398.2; food biomarker) along with glycinoeclepin B (m/z 558.28; nutrient, emulsifier, surfactant) was noted. Two flavonoids; (S)‐(E)‐2′‐(3,6‐dimethyl‐2‐heptenyl)‐3′,4′,7‐trihydroxyflavanone and (S)‐(E)‐8‐(3,6‐dimethyl‐2‐heptenyl)‐4′,5,7‐trihydroxyflavanone (m/z 396.19) and a drug triclofos (m/z 227.89; sedative) were detected. This study highlights the metabolic makeup of D. dichotoma collected from Kachchh coast thereby, accentuating the probability of its inclusion as a promising ingredient in functional foods from algal origin.
Influence of basalt fibers on the mechanical behavior of concrete—A review
Authors: John Vinotha Jenifer , Dharmar Brindha
Published: February 2020

The natural fibers are evolving in the construction industry in many forms due to its dominant characteristics since decades. This paper delivers a review of the behavior of basalt fiber reinforced concrete under static and dynamic loading conditions. The main aim of the paper is to signify the influence of basalt fibers in concrete as chopped fibers, minibars, rebars, and meshes by showcasing the physical and mechanical properties of the concrete. The proposed review paper furnishes a summary of obtainable evidence about the incorporation of basalt fibers in concrete under various loading conditions. The effect of size and volume fraction of the fibers in concrete subjected to static loading and dynamic loading is discussed and reviewed. Additionally, the optimum length, diameter, and aspect ratio of the fibers with its volume fraction depending on the constituents in concrete is exhibited. Basalt fibers, can operate as an exceptional reinforcing material which can replace the conventional reinforcement with appropriate implementation.

Highlights

Application of basalt fibers in concrete based on different loading conditions has been reviewed.

Properties and applications of basalt fibers in various forms were assessed.

Static and dynamic behavior of basalt fiber reinforced concrete has been summarized based on the studied literature.

Addition of suitable forms and size of basalt fibers in concrete were examined.

Parameters such as volume fraction, aspect ratio of basalt fibers has been highlighted.
A review of nonrevenue water assessment software tools
Authors: AL‐Washali Taha M. , Elkhider Mohamed E. , Sharma Saroj K. , Kennedy Maria D.
Published: February 2020

Several software tools are available that can assess the performance of nonrevenue water (NRW) in water distribution networks and plan for reduction measures. Of the 21 tools that have been reported in the literature, 12 are freely available. The creation of these many tools and different versions of each individual tool indicates the promising future of NRW software development. This review comprises 12 freely available tools for water balance establishment, NRW performance assessment, and NRW reduction planning. Most of the tools have been developed to establish standard annual water balances and recommended performance indicators (PIs) for the entire network. Some tools have been developed to intervene and reduce the leakage in a district metered area. Key features increasingly being included in NRW software include uncertainty analysis, recognition of supply intermittency, and accommodation of a guidance matrix and benchmarks. Leakage assessment is fully recognized, and leakage reduction analyses are increasingly growing in the software tools. However, much less attention has been paid to assessing and options for reducing apparent losses. Although a comprehensive NRW management tool for monitoring, planning, and intervention is not currently available, developing a comprehensive tool is worthwhile, in the form of one package or a kit of smaller tools. Toward this goal, the article provides insights and recommendations addressing topics of intermittency, normalization, multi‐method assessment, planning for the reduction of apparent and real losses, and estimation of the economic level of water loss.

This article is categorized under:

Engineering Water > Planning Water

Engineering Water > Methods
A survey and taxonomy of adversarial neural networks for text‐to‐image synthesis
Authors: Agnese Jorge , Herrera Jonathan , Tao Haicheng , Zhu Xingquan
Published: February 2020

Text‐to‐image synthesis refers to computational methods which translate human written textual descriptions, in the form of keywords or sentences, into images with similar semantic meaning to the text. In earlier research, image synthesis relied mainly on word to image correlation analysis combined with supervised methods to find best alignment of the visual content matching to the text. Recent progress in deep learning (DL) has brought a new set of unsupervised DL methods, particularly deep generative models which are able to generate realistic visual images using suitably trained neural network models. The change of direction from the computer vision‐based approaches to artificial intelligence (AI)‐driven methods ignited the intense interest in industry, such as virtual reality, recreational & professional (eSports) gaming, and computer‐aided design, and so on, to automatically generate compelling images from text‐based natural language descriptions. In this paper, we review the most recent development in the text‐to‐image synthesis research domain. Our goal is to provide value by delivering a comparative review of the state‐of‐the‐art models in terms of their architecture and design. The survey first introduces image synthesis and its challenges, and then reviews key concepts such as generative adversarial networks (GANs) and deep convolutional encoder‐decoder neural networks (DCNNs). After that, we propose a taxonomy to summarize GAN‐based text‐to‐image synthesis into four major categories: semantic enhancement GANs, resolution enhancement GANs, diversity enhancement GANS, and motion enhancement GANs. We elaborate on the main objective of each group, and further review typical GAN architectures in each group. The taxonomy and the review outline the techniques and the evolution of different approaches, and eventually provide a roadmap to summarize the list of contemporaneous solutions that utilize GANs and DCNNs to generate enthralling results in categories such as human faces, birds, flowers, room interiors, object reconstruction from edge maps (games), and so on. The survey concludes with a comparison of the proposed solutions, challenges that remain unresolved, and future developments in the text‐to‐image synthesis domain.

This article is categorized under:

Algorithmic Development > Multimedia

Technologies > Machine Learning
The geometry of SUSY enhancement
Authors: Carta Federico , Giacomelli Simone , Hayashi Hirotaka , Savelli Raffaele
Published: February 2020

Abstract

We provide a precise geometric picture that demystifies the phenomenon of supersymmetry enhancement along certain RG flows of four-dimensional field theories, recently discovered by Maruyoshi and Song. It applies to theories of arbitrary rank and it is based on a hyperkähler-structure restoration on the moduli space of solutions of (twisted) Hitchin systems, which underly the class-$$ \mathcal{S} $$
S
construction we use as an engineering tool. Along the way, we formulate a necessary algebraic condition for supersymmetry enhancement, and, when enhancement occurs, we are able to derive the Seiberg-Witten geometry and all conformal dimensions of Coulomb-branch operators for the infrared theory, without using a-maximization.
The Mixed Degree of Families of Lattice Polytopes
Authors: Nill Benjamin
Published: February 2020

The degree of a lattice polytope is a notion in Ehrhart theory that was studied quite intensively over previous years. It is well known that a lattice polytope has normalized volume one if and only if its degree is zero. Recently, Esterov and Gusev gave a complete classification result for families of n lattice polytopes in $${\mathbb {R}}^n$$Rn whose mixed volume equals one. Here, we give a reformulation of their result involving the novel notion of mixed degree that generalizes the degree similar to how the mixed volume generalizes the volume. We discuss and motivate this terminology, also from an algebro-geometric viewpoint, and explain why it extends a previous definition of Soprunov. We also remark how a recent combinatorial result due to Bihan solves a related problem posed by Soprunov.
Spectroscopy and diode-pumped continuous-wave laser operation of Tm:Y2O3 transparent ceramic at cryogenic temperatures
Authors: Yue Fangxin , Jambunathan Venkatesan , Paul David Samuel , Mateos Xavier , Aguiló Magdalena , Díaz Francesc , Šulc Jan , Lucianetti Antonio , Mocek Tomáš
Published: February 2020

We present the spectroscopic and laser characteristics of a 3 at.% Tm:Y2O3 transparent ceramic at cryogenic temperatures. An absorption cross section of 4.7 × 10−21 cm2 with a bandwidth of 0.7 nm centered at 793.3 nm and an emission cross section of 29.0 × 10−21 cm2 centered at 1930.9 nm were estimated at 80 K. Continuous-wave laser operation was achieved using broadband and VBG stabilized laser diodes emitting around 793 nm as pump sources. With the VBG pump diode, a maximum output power of 6.4 W was achieved at 80 K corresponding to a slope efficiency of 52.0% with respect to absorbed power.