bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel preparation method of polypropylene/natural rubber blends with improved toughness
Authors: Lendvai László
Published: October 2020

A novel melt compounding method – originally introduced for the preparation of nanocomposites – was adapted to produce polypropylene (PP) based blends toughened with up to 20 wt% natural rubber (NR). This water‐assisted technique is based on batchwise melt mixing, where the additives are introduced as an aqueous dispersion into the matrix, drop by drop. The efficiency of this preparation technique was analyzed by comparing the resulting blends with reference samples produced by traditional melt mixing. Mechanical, thermomechanical and morphological properties were determined in order to investigate the structure–property relationships. According to SEM analyses, the average domain size of NR within the PP matrix became significantly smaller when the water‐assisted method was applied. Charpy impact tests showed that the toughening efficiency of NR particles within the PP was enhanced as a result of their decreased size. This improvement was more prominent when the difference between the viscosity of PP and NR was higher. In addition, applying the water‐assisted technique led to an enhanced deformability with similar strength and stiffness compared to common melt mixing. © 2020 The Author. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.
New sustainable alternating semi‐aromatic polyamides prepared in bulk by direct solid‐state polymerization
Authors: Wolffs Martin , Cotton Lucy , Kolkman Ard J , Rulkens Rudy
Published: October 2020

New semi‐aromatic bio‐based copolyamides PA 4T/4Y and PA 6T/6Y were successfully synthesized in bulk by direct solid‐state polycondensation in which hydrophobic bio‐based dicarboxylic acids sebacic acid, octadecanedioic or hydrogenated dimer fatty acid (Y = C10, C18 or C36) alternate with terephthalic acid T. The absence of a polymerization solvent and the possibility of performing the polymerization on the dicarboxylic acid make it an interesting route for future production of alternating copolyamides. A stepwise synthetic approach is taken where first terephthalic acid‐based diamide diamines of the linear C4 or C6 diamines 4T4 or 6T6 are prepared, followed by preparation of solid salts with the above aliphatic dicarboxylic acids and subjecting the salts to a solid‐state post‐condensation. The alternation is achieved by the interlocking of the 4T4 or 6T6 units in the salts with the bio‐based dicarboxylic acids and polymerizing these salts below the melt temperature of the terephthalamide‐based core. During the polycondensation, the transamidation reaction of the terephthalamide moiety is prevented and with that the randomization of the polyamide. Especially the diaminobutane‐based PA 4T/4Y copolyamides show strict alternation, leading to interesting properties like high crystallinity and high melting points of 250 to 318 °C supported by a randomness value of 2, determined using 13C NMR spectroscopy. The special alternating feature becomes especially clear when heating the polymer in the melt state, when the transamidation of the terephthalamide moieties is no longer prevented by the interlocking principle, leading to lowering of the randomness value and therewith the melting point and crystallinity. © 2020 Society of Industrial Chemistry
Towards the targeted assessment of relevant problems: Optimization of the distress Thermometer for adult neuro‐oncological patients
Authors: Goebel Simone , Knuth Carina , Damm Matthias , Linden Daniel , Coburger Jan , Ringel Florian , Tabatabai Ghazaleh , Mehdorn Maximilian , Renovanz Mirjam
Published: October 2020

Objective

Generic psychosocial screening tools may not reflect the unique symptom profile of brain tumour patients (BTPs). The aim was to adapt the problem list of the distress thermometer (DT) for BTPs.

Methods

First, items of low relevance for BTPs were identified on basis of retrospective analyses. Second, relevant yet missing problems were identified via an extensive literature search, qualitative interviews with BTPs and experts, as well as an online expert survey. The resulting raw version of the adapted problem list in BTPs was subsequently pretested.

Results

In the first part, data of n = 657 BTPs were analysed. Twelve items (20%) were excluded in this step as they proved to be less relevant for BTPs (i.e., items were endorsed by less than 10% and without significant correlations to patients' DT score). In the second part, qualitative interviews and the online survey with 102 professionals led to the addition of 21 new and the modification and condensation of 17 relevant problems specific for BTPs. This adapted list was than successfully pretested in n = 19 patients, leading to the ‘distress thermometer brain tumour problem list’ (DT‐BT), consisting of 42 relevant problems.

Conclusion

The adapted problem list for the DT particularly reflects the neurological and psychosocial burden of an intracranial tumour and allows for the targeted assessment of the specific burdens and needs of BTPs. Our revised version of the DTs problem list (DT‐BT) should in the next step be widely validated in multinational samples.
Prevalence of exercise‐induced bronchoconstriction and laryngeal obstruction in adolescent athletes
Authors: Ersson Karin , Mallmin Elisabet , Malinovschi Andrei , Norlander Katarina , Johansson Henrik , Nordang Leif
Published: October 2020

Objectives

To study the prevalence of exercise‐induced bronchoconstriction (EIB) and exercise‐induced laryngeal obstruction (EILO) in adolescent athletes.

Methods

All adolescents (n = 549) attending first year at a sports high school in 2016 and 2017, were invited to answer a questionnaire on respiratory symptoms. The 367 responding participants were divided into two groups based on whether they reported exercise‐induced dyspnea (dyspnea group) or not (nondyspnea group). Randomly selected participants in each group were invited to undergo two standardized exercise tests, an EIB test and a continuous laryngoscopy exercise (CLE) test, to investigate EILO.

Results

In total, 98 participants completed an EIB test, 75 of whom also completed a CLE test. Positive EIB tests: eight of 41 in the dyspnea group and 16 of 57 in the nondyspnea group. Positive CLE tests: 5 of 34 in the dyspnea group and three of 41 in the nondyspnea group. The estimated prevalence of EIB was 23.1% (95% confidence interval [CI]: 14.5–33.8) and of EILO 8.1% (95% CI: 2.5–18.5) in the whole study population. No differences in prevalence of EIB or EILO were found between the dyspnea and the nondyspnea groups.

Conclusion

EIB was highly prevalent in this cohort of adolescent athletes. EILO was less prevalent, but represents an important differential diagnosis to EIB. Self‐reported exercise‐induced dyspnea is a weak indicator for both EIB and EILO and standardized testing should be provided.
Conifold Vacua with Small Flux Superpotential
Authors: Demirtas Mehmet , Kim Manki , McAllister Liam , Moritz Jakob
Published: October 2020

We introduce a method for finding flux vacua of type IIB string theory in which the flux superpotential is exponentially small and at the same time one or more complex structure moduli are stabilized exponentially near to conifold points.
Comparison of strategies for enhancing RNA interference efficiency in Ostrinia nubilalis
Authors: Cooper Anastasia MW , Song Huifang , Yu Zhitao , Biondi Marie , Bai Jun , Shi Xuekai , Ren Zhaoyang , Weerasekara Sahani M , Hua Duy H , Silver Kristopher , Zhang Jianzhen , Zhu Kun Yan
Published: October 2020

BACKGROUND

Targeting insect‐specific genes through post‐transcriptional gene silencing with RNA interference (RNAi) is a new strategy for insect pest management. However, lepidopterans are recalcitrant to RNAi, which prevents application of novel RNAi technology to many notorious pests, including Ostrinia nubilalis (ECB). Strategies for enhancing RNAi efficiency, including large doses of double‐stranded RNA (dsRNA), nuclease inhibitors, transfection reagents, and nanoparticles, have proved useful in other insects exhibiting substantial dsRNA degradation, a major mechanism limiting RNAi efficacy. To determine if similar strategies can enhance RNAi efficiency in ECB, various reagents were tested for their ability to enhance dsRNA stability in ECB tissues, then compared for their effectiveness in whole ECB.

RESULTS

Ex vivo incubation experiments revealed that Meta dsRNA lipoplexes, EDTA, chitosan‐based dsRNA nanoparticles, and Zn2+ enhanced dsRNA stability in ECB hemolymph and gut content extracts, compared with uncoated dsRNA. Despite these positive results, the reagents used in this study were ineffective at enhancing RNAi efficiency in ECB in vivo. To reduce assay time and required dsRNA, midguts were dissected and incubated in tissue culture medium containing dsRNA with and without reagents. These experiments showed that RNAi efficiency varied between target genes, and nuclease inhibitors improved RNAi efficiency for only a portion of the refractory target genes investigated ex vivo.

CONCLUSION

These results indicate that enhancing dsRNA stability is insufficient to improve RNAi efficiency in ECB and suggests the existence of additional, complex mechanisms contributing to low RNAi efficiency in ECB.
Effect of zinc oxide nanoparticle supplementation on the enhanced production of surfactin and iturin lipopeptides of endophytic Bacillus sp. Fcl1 and its ameliorated antifungal activity
Authors: Ravi Aswani , Nandayipurath Vipina Vinod Thazhe , Rajan Sukanya , Salim Simi Asma , Khalid Nejumal Kannankeril , Aravindakumar Charuvila T , Krishnankutty Radhakrishnan Edayileveettil
Published: October 2020

BACKGROUND

Lipopeptides from the Bacillus spp. possess an excellent spectrum of antimicrobial properties which make them suitable candidates to be explored for the food, agricultural, pharmaceutical and biotechnological applications. As the low yield of the lipopeptides limits their applications, methods to enhance their production are highly significant.

RESULTS

In this study, extracts prepared from endophytic Bacillus sp. Fcl1 cultured in the presence of various supplements were screened for antifungal activity against Pythium aphanidermatum. From the results, the supplementation of carbon sources and zinc oxide nanoparticles (ZnONPs) was found to have an enhancement effect on the antifungal activity of Bacillus sp. Fcl1. Among these, the highest antifungal activity (73.2%) could be observed for the Fcl1 sample cultured with 5 mg L−1 of ZnONP supplementation. The growth of Fcl1 in the presence of ZnONPs also indicated its compatibility with the nano‐supplement in the concentration range used. By liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC‐Q‐TOF‐MS) analysis, the synthesis of increased numbers of lipopeptide surfactin derivatives could be identified from the extracts of Fcl1 prepared from the carbon sources and ZnONP‐supplemented cultures. In addition to the surfactin derivatives, the presence of another lipopeptide iturin was also detected from the extracts of Fcl1 cultured with ZnONPs.

CONCLUSION

ZnONP supplementation was found to enhance antifungal activity and lipopeptide production in the Bacillus sp. Fcl1. The use of nanoparticles to enhance the antifungal mechanisms of Fcl1 as observed in the study provides novel insights to explore its applications for sustainable agricultural productivity.
Characteristics of cyclones following different pathways in the Gulf Stream region
Authors: Tsopouridis Leonidas , Spensberger Clemens , Spengler Thomas
Published: October 2020

The Northwest Atlantic is a region of strong temperature gradients and hence is a favourable location for wintertime cyclone intensification co‐located with the storm track. The temperature gradient is associated with both the sea surface temperature front along the Gulf Stream and the land–sea contrast. To understand the respective influences of the sea surface temperature (SST) front and land–sea contrast in the Gulf Stream region, as well as the role of upper‐level forcing on cyclone development, we track individual cyclones and categorise them depending on their propagation relative to the SST front. We concentrate on cyclones staying either on the cold (C1) or warm (C2) side of the SST front, and on cyclones that cross the SST front from the warm to the cold side (C3). Comparing these categories, we find that the land–sea contrast is more important for supplying baroclinicity to cyclones in C1, while the strong low‐level baroclinicity in C3 is also partially attributable to the SST front. The propagation of cyclones in C1 and C3 near the left exit region of the North Atlantic jet explains the higher intensification and precipitation.
Mechanistic investigation on ethanol‐to‐butadiene conversion reaction over metal oxide clusters
Authors: Butera Valeria , Tanabe Yusuke , Shinke Yu , Miyazawa Tomohisa , Fujitani Tadahiro , Kayanuma Megumi , Choe Yoong‐Kee
Published: October 2020

Density functional theory (DFT) calculations were conducted to investigate mechanistic details of ethanol‐to‐butadiene conversion reaction over MgO or ZnO catalyst. We evaluated the Lewis acidity and basicity of MgO and ZnO and found that ZnO had the stronger Lewis acidity and basicity than MgO. Potential energy surfaces of ethanol‐to‐butadiene conversion, which included relevant transition states and intermediates, were computed in detail following the generally accepted mechanism reported in the literature, where such mechanism included ethanol dehydrogenation, aldol condensation, Meerwein‐Pondorf‐Verley reduction, and crotyl alcohol dehydration. DFT results showed that ethanol dehydrogenation was the rate‐limiting step of overall reaction when the reaction was catalyzed by MgO. Also, DFT results showed that ethanol dehydrogenation occurred more easily on ZnO than on MgO, where such a result correlated with the stronger Lewis acidity of ZnO. In addition, we computed ethanol dehydration, which generates ethylene, one of the major undesired side reaction products for butadiene formation. DFT results showed that ZnO favored dehydrogenation over dehydration, while MgO favored dehydration.
Fault accommodation controller under Markovian jump linear systems with asynchronous modes
Authors: Carvalho L. P. , Rosa T. E. , Jayawardhana B. , Costa O. L. V.
Published: October 2020

We tackle the fault accommodation control (FAC) in the Markovian jump linear system (MJLS) framework for the discrete‐time domain, under the assumption that it is not possible to access the Markov chain mode. This premise brings some challenges since the controllers are no longer allowed to depend on the Markov chain, meaning that there is an asynchronism between the system and the controller modes. To tackle this issue, a hidden Markov chain (, ) is used where denotes the Markov chain mode, and denotes the estimated mode. The main novelty of this work is the design of and FAC under the MJLS framework considering partial observation of the Markov chain. Both designs are obtained via bilinear matrix inequalities optimization problems, which are solved using coordinate descent algorithm. As secondary results, we present simulations using a two‐degree of freedom serial flexible joint robot to illustrate the viability of the proposed approach.
Synthesis, Characterisation, and Performance Evaluation of Promoted Ni‐Based Catalysts for Thermocatalytic Decomposition of Methane
Authors: Awad Ali , Alnarabiji Mohamad S. , Salam Md. A. , Vo Dai‐Viet N. , Setiabudi Herma D. , Abdullah Bawadi
Published: October 2020

Thermocatalyatic decomposition (TCD) of methane to COX free hydrogen and carbon nanofibre (CNF) was investigated over a series of self‐designed monometallic Ni catalyst and bimetallic Ni−Cu and Ni−Pd catalysts. The catalysts were synthesised from the wet impregnation method and characterised using a series of complementary techniques include TGA, XRD, BET, TPR, FESEM, TEM, and Raman Spectroscopy. Despite a substantial reduction of surface area in the promoted catalysts, the catalytic activity of the promoted catalyst was enhanced due to the nature of the process which is a metal‐catalysed reaction. As a whole, bimetallic Pd−Ni catalyst with a surface area of 2.76 m2 g−1 possesed the highest conversion of 77 % after 6 h reaction. The overall TCD reaction was found to be first‐order with the calculated activation energy, Ea of 38 kJ mol−1. The methane consumption rates at 1023 K and 1073 K were 0.5 mol s−1gcat−1 and 0.58×104 mol s−1gcat−1 respectively. Meanwhile, the methane consumption rates improved considerably from 0.58 mol s−1gcat−1 to 0.67×104 mol s−1gcat−1 under the methane partial pressure of 41 kPa. The XRD profile of the fresh catalysts revealed that mixed oxides were formed over the surface of the support upon the addition of Cu and Pd to 50 %Ni/Al2O3. Moreover, the formation of carbon nanofibers followed both tip and base growth mechanisms as evident from the TEM images. Larger and wider carbon fibres were found in the Pd promoted catalyst.
Extraction and Characterization of Pectin from the Fruit Peel of Opuntia robusta
Authors: Mota Jaquelinne , Muro Claudia , Illescas Javier , Hernández Omar A. , Tecante Alberto , Rivera Ernesto
Published: October 2020

In this study, pectin extraction from fruits peel of Opuntia robusta was investigated. Pectin was extracted by microwave and conventional heating methods, and the product was analysed to determine the yield, esterification degree, galacturonic acid content, molar mass, antioxidant, emulsifying and rheological properties. The extraction methods resulted in two different types of pectin: pectin I, with high (>50 %) methoxyl degree of esterification, and pectin II, with low, (<50 %) methoxyl degree of esterification. The extraction yield of these pectins was 14.64 and 15.71 %, with molar masses of 33,110 and 20,339 g mol−1, respectively. Pectin II showed the highest galacturonic acid content (47.05 %) in comparison with pectin I (31.74 %). The antioxidant properties of pectins showed similar polyphenols content. However, pectin II had the highest scavenging activity. Finally, pectin I displayed the best emulsifying properties, and both pectins produced shear‐thinning solutions and predominantly elastic gel behaviour.
Bioreduction of Gold Ions from Anisotropic to Isotropic Nanostructures by NADPH‐Dependent Reductase from Bipolaris oryzae
Authors: Dhanasekar Naresh N. , Shirke Anupama , Sakthivel Natarajan
Published: October 2020

Here, we report an eco‐friendly, benign and rapid mycogenic synthesis of gold nanoparticles of various shapes using cell‐free extract of the fungus Bipolaris oryzae (B. oryzae). Three different volumes of cell‐free extract of the fungus were exposed to an aqueous solution of gold chloride and in all three cases, there is a gradual color change from light yellow to pink indicating the formation of gold nanoparticle. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) dependent enzyme present in the cell‐free extract of the fungus B. oryzae leads to the rapid reduction of Au3+ to Au0 within 5–10 min when incubated with an aqueous solution of gold chloride. UV‐visible and fourier transform infra red (FTIR) spectroscopy measurements show the presence of aminoacids, such as tyrosine/phenylalanine and proteins as the possible capping agent. High‐resolution transmission electron microscopy (HR‐TEM) revealed the morphology of the structures were anisotropic triangles, hexagons, decahedrals and isotropic spheres. Isotropic spherical nanoparticles and anisotropic nanoparticles such as triangles, hexagons and decahedrals were produced at higher and lower volumes of the fungal extract, respectively. Rapid and sustainable approach for the production of gold nanoparticles of various shapes such as the one reported has a plethora of applications in the field of life‐sciences and medicine.
Negligible Effect on the Structure and Vibrational Spectral Dynamics of Water Molecules Near Hydrophobic Solutes
Authors: Biswas Sohag , Mallik Bhabani S.
Published: October 2020

The first principles molecular dynamics simulations were performed to study the structural, dynamical, and spectral properties of water molecules in the vicinity of hydrophobic molecules. A layer‐wise distance‐dependent angular distribution calculation was performed to understand the effects of neopentane (NEO) and tert‐butyl alcohol (TBA) on the orientation profile of water molecules. We found no evidence of an increasing tetrahedral structure of water molecules inside the first solvation shell of NEO and TBA; this indicates the presence of less ordered water molecules inside the solvation shell. The water molecules, however, retained their bulk‐like property by accruing three to four hydrogen bonds per water molecule in bulk. The long‐lived non‐hydrogen‐bonded or dangling OH bonds were observed in the hydration shells of both the molecules as compared to the bulk water, where such dangling OH bonds were less. The high peak frequency of dangling OH oscillators in the hydration shell was found to be similar to the previously obtained dangling OH chromophores in experimental and theoretical studies. We also report the rotational dynamics of water molecules. Our calculations suggest that the slowing down of water molecules near the hydrophobic solutes is moderate as compared to that of bulk water due to the lack of hydrogen bond exchangeable partners. Therefore, our results are in complete contrast with the idea of the iceberg of Frank and Evan.
Catalytic Hydrogenation of Methyl Acetate to Ethanol over Boron Doped Carbon Aerogels Supported Cu Catalyst
Authors: Wu Mengmeng , Hou Xiaoxiong , Quan Yanhong , Zhao Jinxian , Ren Jun
Published: October 2020

The hydrogenation of methyl acetate (MA) is a crucial step to obtain ethanol from coal‐syngas indirectly. In this paper, boron doped carbon aerogel (BCAs) has been prepared successfully and applied as support for copper‐base catalyst due to its unique physicochemical properties. The influence of boron on copper‐based catalysts Cu/xBCAs (x=1, 3, 5) for the hydrogenation of methyl acetate (MA) to ethanol is studied systematically. H2‐N2O and XRD prove that appropriate amount of boron not only improves the dispersion of active copper species, but also achieves the higher percentage of Cu+ in (Cu++Cu0). The catalyst Cu/3BCAs performs the best catalytic activity with methyl acetate (MA) conversion of 90.6 % and ethanol selectivity of 59.9 %, respectively. The high catalytic activity comes from the highest proportion of Cu+ on the Cu/3BCAs due to the lower reducibility of Cu+ species caused by the relatively high affinity of boron with electrons.
Three Amino‐functionalized Alkaline Earth Metal‐Organic Frameworks as Catalysts for Knoevenagel Condensation
Authors: Song Xiuduo , He Yanzhen , Cai Zhe , Li Xiaoyun , Sun Yanmin , Liu Hongguang , Lu Yanfei , Hou Jie , Han Enshan
Published: October 2020

Three amino‐functionalized alkaline earth Metal‐Organic Frameworks (MOFs), including Mg‐ABDC [Mg(ABDC)(DMF)], Ca‐ABDC [Ca(ABDC)(DMF)] and Sr‐ABDC [Sr(ABDC)(DMF)]( ABDC=2‐aminobenzene‐1,4‐dicarboxylate anion), were synthesized under solvothermal conditions. The incorporation of alkaline earth metals and N‐containing ligands is an effective way to increase the basicity of MOFs. To explore catalytic activity of three alkaline earth MOFs, they were applied to catalyze the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate to produce ethyl (E)‐α‐cyanocinnamate. All three alkaline earth MOFs had high catalytic performance, among which Mg‐ABDC showed the best performance. The activity of catalyst was expressed by the conversion rate and selectivity. The conversation rate was up to 94.7 % and the selectivity was nearly 100 % by adding Mg‐ABDC. Mg‐ABDC was proved to be an efficient, stable and heterogeneous catalyst through hot filtration and recycling tests.
Morphology Evolution of a High‐Efficiency PSC by Modulating the Vapor Process
Authors: Yao Zhun , Zhao Wangen , Xu Zhuo , Wen Jialun , Liu Shengzhong (Frank)
Published: October 2020

The morphological quality of the photoactive layer is the key component affecting the performance metrics of a photovoltaic device. Therefore, fine adjustment of the crystallization dynamics is urgently required. By manipulating the amount of dimethyl sulfoxide (DMSO) remaining in the spin‐coated perovskite films during the annealing treatment, an obvious morphological evolution arises. The crystallization kinetics is significantly altered due to the formation of intermediate phases and the variation of DMSO vapor pressure via producing the semienclosed space with a covering. On the one hand, the obviously formed intermediate phase MA2Pb3I8(DMSO)2 retards the crystallization process. On the other hand, the DMSO vapor in the semienclosed space intrigues the recrystallization process and results in Ostwald ripening to produce large‐aspect‐ratio grains with fewer defect states, decreased carrier doping, and longer carrier lifetimes. Thus, nonradiative processes are greatly suppressed. Besides, combined with X‐ray photoelectron spectroscopy measurement and the surface energy of MAI‐ and PbI‐terminated surface model calculated by density functional theory, the defect states are identified and the causes of Pb0 defect states are explained. Using this strategy, a high power conversion efficiency of 20.09% is achieved based on MAPbI3 photovoltaic solar cell, and the long‐term ambient shelf and thermal stability are obviously improved.
Energy‐Saving Multisensor Data Sampling and Fusion with Decision‐Making for Monitoring Health Risk Using WBSNs
Authors: Jaber Alaa Shawqi , Idrees Ali Kadhum
Published: October 2020

The necessity of developing sufficient systems to monitor health conditions has increased due to the aging of the population and the prevalence of chronic diseases, creating a demand for remote health care systems that make use of biosensors. This article proposes an energy‐saving multisensor data sampling and fusion with decision‐making for the monitoring of patient health risk in wireless body sensor networks (WBSNs). The work consists of three steps: energy‐efficient sampling rate adaptation, multisensor data fusion, and decision‐making. The sampling is performed in each biosensor and it adapts its rate based on the local risk and the global risk in which global risk computed at the coordinator, where the data is fused afterward. Finally, decisions are made according to the risk level of the patient. The processing of these functions enables in real‐time the adoption of the biosensor sampling rates based on the dynamic risk level of each biosensor, and a corresponding decision is made whenever an emergency is detected. The performance of the suggested approach is evaluated using actual health datasets, and some of its aspects are put into comparison with an existing approach, such as the data reducing and energy‐consuming rates. The acquired results illustrate a decrease in the volume of gathered data, thus a significant energy saving has been made while preserving data accuracy and integrity. Moreover, presenting a data fusing model at the coordinator level by means of an early warning score system has assessed the health condition of patients and took an appropriate decision when detecting emergencies.
Comparison of the performance of 22 models describing soil water retention curves from saturation to oven dryness
Authors: Du Chaoyang
Published: October 2020

Soil water retention curve (SWRC) is key hydraulic property for vadose zone hydrology. Selected 22 SWRC models with different structures were divided into four types: traditional, single‐segment, two‐segment, and three‐segment models. According to the accuracy and model selection criterion, these models were compared and evaluated using water retention data from saturation to oven dryness of 94 soil samples covering almost all soil types. Among the models, the EG model (exponential model combined with the Groenevelt–Grant model) shows the best performance, but the BC (Brooks–Corey) and VG (van Genuchten) models performed the worst. The relationship between model performance and complexity showed that traditional models with residual water content performed worse than segmental models from saturation to oven dryness, and the segmental models performed worse with an increase in the segment number. In general, models with more parameters perform better, but when the parameter number is greater than five, the model performance gradually worsens due to the equifinality of different parameters. The correlation analysis between soil properties on model performance showed that soil texture has a more significant effect on model performance than bulk density and organic matter content, because the models are primarily affected by their mathematical forms rather than the physical significance of the parameters. Each model picks its limitations and may apply to only one or particular group(s) of soil(s). Therefore, the complementarities of different models may be a great choice to improve SWRC fitting and simulation in arid soil.
Confronting grand unification with lepton flavour violation, dark matter and LHC data
Authors: Ellis J. , Gómez M. E. , Lola S. , Ruiz de Austri R. , Shafi Q.
Published: October 2020

Abstract

We explore possible signatures for charged lepton flavour violation (LFV), sparticle discovery at the LHC and dark matter (DM) searches in grand unified theories (GUTs) based on SU(5), flipped SU(5) (FSU(5)) and SU(4)c×SU(2)L×SU(2)R (4-2-2). We assume that soft supersymmetry-breaking terms preserve the group symmetry at some high input scale, and focus on the non-universal effects on different matter representations generated by gauge interactions at lower scales, as well as the charged LFV induced in Type-1 see-saw models of neutrino masses. We identify the different mechanisms that control the relic DM density in the various GUT models, and contrast their LFV and LHC signatures. The SU(5) and 4-2-2 models offer good detection prospects both at the LHC and in LFV searches, though with different LSP compositions, and the SU(5) and FSU(5) models offer LFV within the current reach. The 4-2-2 model allows chargino and gluino coannihilations with neutralinos, and the former offer good detection prospects for both the LHC and LFV, while gluino coannihilations lead to lower LFV rates. Our results indicate that LFV is a powerful tool that complements LHC and DM searches, providing significant insights into the sparticle spectra and neutrino mass parameters in different models.
Classical and quantum double copy of back-reaction
Authors: Adamo Tim , Ilderton Anton
Published: October 2020

Abstract

We consider radiation emitted by colour-charged and massive particles crossing strong plane wave backgrounds in gauge theory and gravity. These backgrounds are treated exactly and non-perturbatively throughout. We compute the back-reaction on these fields from the radiation emitted by the probe particles: classically through background-coupled worldline theories, and at tree-level in the quantum theory through three-point amplitudes. Consistency of these two methods is established explicitly. We show that the gauge theory and gravity amplitudes are related by the double copy for amplitudes on plane wave backgrounds. Finally, we demonstrate that in four-dimensions these calculations can be carried out with a background-dressed version of the massive spinor-helicity formalism.
Chaos from massive deformations of Yang-Mills matrix models
Authors: Başkan K. , Kürkçüoğlu S. , Oktay O. , Taşcı C.
Published: October 2020

Abstract

We focus on an SU(N) Yang-Mills gauge theory in 0 + 1-dimensions with the same matrix content as the bosonic part of the BFSS matrix model, but with mass deformation terms breaking the global SO(9) symmetry of the latter to SO(5)×SO(3)×ℤ2. Introducing an ansatz configuration involving fuzzy four and two spheres with collective time dependence, we examine the chaotic dynamics in a family of effective Lagrangians obtained by tracing over the aforementioned ansatz configurations at the matrix levels$$ N=\frac{1}{6} $$N=16(n+ 1)(n+ 2)(n+ 3), forn= 1,2, · · · ,7. Through numerical work, we determine the Lyapunov spectrum and analyze how the largest Lyapunov exponents(LLE) change as a function of the energy, and discuss how our results can be used to model the temperature dependence of the LLEs and put upper bounds on the temperature above which LLE values comply with the Maldacena-Shenker-Stanford (MSS) bound 2πT, and below which it will eventually be violated.
Bootstrapping conformal four-point correlators with slightly broken higher spin symmetry and 3D bosonization
Authors: Li Zhijin
Published: October 2020

Abstract

Three-dimensional conformal field theories (CFTs) with slightly broken higher spin symmetry provide an interesting laboratory to study general properties of CFTs and their roles in the AdS/CFT correspondence. In this work we compute the planar four-point functions at arbitrary ’t Hooft coupling λ in the CFTs with slightly broken higher spin symmetry. We use a bootstrap approach based on the approximate higher spin Ward identity. We show that the bootstrap equation is separated into two parts with opposite parity charges, and it leads to a recursion relation for the λ expansions of the correlation functions. The λ expansions terminate at order λ2 and the solutions are exact in λ. Our work generalizes the approach proposed by Maldacena and Zhiboedov to four-point correlators, and it amounts to an on-shell study for the 3D Chern-Simons vector models and their holographic duals in AdS4. Besides, we show that the same results can also be obtained rather simply from bosonization duality of 3D Chern-Simons vector models. The odd term at order O(λ) in the spinning four-point function relates to the free boson correlator through a Legendre transformation. This provides new evidence on the 3D bosonization duality at the spinning four-point function level. We expect this work can be generalized to a complete classification of general four-point functions of single trace currents.
CAAI—a cognitive architecture to introduce artificial intelligence in cyber-physical production systems
Authors: Fischbach Andreas , Strohschein Jan , Bunte Andreas , Stork Jörg , Faeskorn-Woyke Heide , Moriz Natalia , Bartz-Beielstein Thomas
Published: October 2020

This paper introduces CAAI, a novel cognitive architecture for artificial intelligence in cyber-physical production systems. The goal of the architecture is to reduce the implementation effort for the usage of artificial intelligence algorithms. The core of the CAAI is a cognitive module that processes the user’s declarative goals, selects suitable models and algorithms, and creates a configuration for the execution of a processing pipeline on a big data platform. Constant observation and evaluation against performance criteria assess the performance of pipelines for many and different use cases. Based on these evaluations, the pipelines are automatically adapted if necessary. The modular design with well-defined interfaces enables the reusability and extensibility of pipeline components. A big data platform implements this modular design supported by technologies such as Docker, Kubernetes, and Kafka for virtualization and orchestration of the individual components and their communication. The implementation of the architecture is evaluated using a real-world use case. The prototypic implementation is accessible on GitHub and contains a demonstration.
Managerial characteristics and budget use in festival organizations
Authors: Knardal Per Ståle , Bjørnenak Trond
Published: October 2020

Festivals are an important part of popular culture and have increased in popularity in recent decades. However, they remain relatively unexplored in the accounting literature, and understanding of the use of management control tools in this context is low. This study aims to investigate the use of budgets in festivals. Informed by upper echelons theory, it investigates how individual and observable characteristics of festival managers are associated with variations in the use of budgets. The study is based on a survey of 61 festival managers from 40 festivals. The findings suggest that festival budgets are particularly important in the planning and coordination process but used less frequently for ex post evaluations. The findings also indicate a positive association between a business educational background and the use of budgets for most purposes, with the exceptions of performance evaluation and reward. This paper contributes to the literature on accounting in popular culture in general and in festivals specifically. Through its application of upper echelons theory, it also contributes to the management accounting and control literature, showing how individual characteristics of managers influence the use of budgets.
A convolutional neural network for fully automated blood SUV determination to facilitate SUR computation in oncological FDG-PET
Authors: Nikulin Pavel , Hofheinz Frank , Maus Jens , Li Yimin , Bütof Rebecca , Lange Catharina , Furth Christian , Zschaeck Sebastian , Kreissl Michael C. , Kotzerke Jörg , van den Hoff Jörg
Published: October 2020

Purpose

The standardized uptake value (SUV) is widely used for quantitative evaluation in oncological FDG-PET but has well-known shortcomings as a measure of the tumor’s glucose consumption. The standard uptake ratio (SUR) of tumor SUV and arterial blood SUV (BSUV) possesses an increased prognostic value but requires image-based BSUV determination, typically in the aortic lumen. However, accurate manual ROI delineation requires care and imposes an additional workload, which makes the SUR approach less attractive for clinical routine. The goal of the present work was the development of a fully automated method for BSUV determination in whole-body PET/CT.

Methods

Automatic delineation of the aortic lumen was performed with a convolutional neural network (CNN), using the U-Net architecture. A total of 946 FDG PET/CT scans from several sites were used for network training (N = 366) and testing (N = 580). For all scans, the aortic lumen was manually delineated, avoiding areas affected by motion-induced attenuation artifacts or potential spillover from adjacent FDG-avid regions. Performance of the network was assessed using the fractional deviations of automatically and manually derived BSUVs in the test data.

Results

The trained U-Net yields BSUVs in close agreement with those obtained from manual delineation. Comparison of manually and automatically derived BSUVs shows excellent concordance: the mean relative BSUV difference was (mean ± SD) = (– 0.5 ± 2.2)% with a 95% confidence interval of [− 5.1,3.8]% and a total range of [− 10.0, 12.0]%. For four test cases, the derived ROIs were unusable (< 1 ml).

Conclusion

CNNs are capable of performing robust automatic image-based BSUV determination. Integrating automatic BSUV derivation into PET data processing workflows will significantly facilitate SUR computation without increasing the workload in the clinical setting.
MGMT methylation may benefit overall survival in patients with moderately vascularized glioblastomas
Authors: Fuster-Garcia Elies , Lorente Estellés David , Álvarez-Torres María del Mar , Juan-Albarracín Javier , Chelebian Eduard , Rovira Alex , Acosta Cristina Auger , Pineda Jose , Oleaga Laura , Mollá-Olmos Enrique , Filice Silvano , Due-Tønnessen Paulina , Meling Torstein R. , Emblem Kyrre E. , García-Gómez Juan M.
Published: October 2020

Objectives

To assess the combined role of tumor vascularity, estimated from perfusion MRI, and MGMT methylation status on overall survival (OS) in patients with glioblastoma.

Methods

A multicentric international dataset including 96 patients from NCT03439332 clinical study were used to study the prognostic relationships between MGMT and perfusion markers. Relative cerebral blood volume (rCBV) in the most vascularized tumor regions was automatically obtained from preoperative MRIs using ONCOhabitats online analysis service. Cox survival regression models and stratification strategies were conducted to define a subpopulation that is particularly favored by MGMT methylation in terms of OS.

Results

rCBV distributions did not differ significantly (p > 0.05) in the methylated and the non-methylated subpopulations. In patients with moderately vascularized tumors (rCBV < 10.73), MGMT methylation was a positive predictive factor for OS (HR = 2.73, p = 0.003, AUC = 0.70). In patients with highly vascularized tumors (rCBV > 10.73), however, there was no significant effect of MGMT methylation (HR = 1.72, p = 0.10, AUC = 0.56).

Conclusions

Our results indicate the existence of complementary prognostic information provided by MGMT methylation and rCBV. Perfusion markers could identify a subpopulation of patients who will benefit the most from MGMT methylation. Not considering this information may lead to bias in the interpretation of clinical studies.

Key Points

• MRI perfusion provides complementary prognostic information to MGMT methylation.

• MGMT methylation improves prognosis in glioblastoma patients with moderate vascular profile.

• Failure to consider these relations may lead to bias in the interpretation of clinical studies.
LI-RADS category 5 hepatocellular carcinoma: preoperative gadoxetic acid–enhanced MRI for early recurrence risk stratification after curative resection
Authors: Wei Hong , Jiang Hanyu , Zheng Tianying , Zhang Zhen , Yang Caiwei , Ye Zheng , Duan Ting , Song Bin
Published: October 2020

Objectives

To explore the role of preoperative gadoxetic acid–enhanced MRI in stratifying the risk of early recurrence in patients with LR-5 hepatocellular carcinoma (HCC) by LI-RADS v2018 after curative resection.

Methods

Between July 2015 and August 2018, this study evaluated consecutive treatment-naïve at-risk LR-5 HCC patients who underwent gadoxetic acid–enhanced MRI examination within 2 weeks before curative resection. The Cox regression analysis was performed to identify potential predictors of early recurrence. Disease-free survival (DFS) rates were analyzed and compared by using the Kaplan-Meier method and log-rank tests.

Results

Fifty-three of 103 (51.5%) patients experienced early recurrence. Three MRI findings were significantly associated with early recurrence: corona enhancement (hazard ratio [HR]: 2.116; p = 0.013), peritumoral hypointensity on hepatobiliary phase (HBP) (HR: 2.262; p = 0.007), and satellite nodule (HR: 2.777; p = 0.005). An additional risk factor was AFP level > 400 ng/mL (HR: 1.975; p = 0.016). Based on the number of MRI predictors, LR-5 HCC patients were stratified into three subgroups: LR-5a (60/103; no predictor), LR-5b (26/103; one predictor), and LR-5c (17/103; two or three predictors), with low, medium, and high risk of early recurrence, respectively. The 2-year DFS rate of LR-5a, LR-5b, and LR-5c patients was 65.0%, 38.5%, and 5.9%, respectively, while the corresponding median DFS was undefined, 17.1 months, and 5.1 months, respectively (p < 0.001).

Conclusions

In at-risk LR-5 HCC patients, corona enhancement, peritumoral hypointensity on HBP, and satellite nodule could be used to preoperatively stratify the risk of early recurrence after hepatectomy.

Key Points

• Corona enhancement, peritumoral hypointensity on HBP, satellite nodule, and serum AFP level > 400 ng/mL were significant predictors of early recurrence in patients with LR-5 HCC after hepatectomy.

• Based on the number of predictive MRI findings, LR-5 HCC patients could be preoperatively stratified into three subgroups: LR-5a, LR-5b, and LR-5c, with significantly different risk of early recurrence and disease-free survival.

• Preoperative risk stratification is essential for the identification of patients at increased risk of postoperative early recurrence, which may contribute to risk-based personalized management for LR-5 HCC patients.
A flow resistive inspiratory muscle training mask worn during high-intensity interval training does not improve 5 km running time-trial performance
Authors: Faghy Mark A. , Brown Peter I. , Davis Nicola M. , Mayes J. P. , Maden-Wilkinson Tom M.
Published: October 2020

Purpose

There is little evidence of the ergogenic effect of flow-resistive masks worn during exercise. We compared a flow-resistive face mask (MASK) worn during high-intensity interval training (HIIT) against pressure threshold loading inspiratory muscle training (IMT).

Methods

23 participants (13 males) completed a 5 km time trial and six weeks of HIIT (3 sessions weekly). HIIT (n = 8) consisted of repeated work (2 min) at the speed equivalent to 95% $${\dot{\text{V}}}$$

V
˙

O2 peak with equal rest. Repetitions were incremental (six in weeks 1, 2 and 6, eight in weeks 3 and 4 and ten in week 5). Participants were allocated to one of three training groups. MASK (n = 8) wore a flow-resistive mask during all sessions. The IMT group (n = 8) completed 2 × 30 breaths daily at 50% maximum inspiratory pressure (PImax). A control group (CON, n = 7) completed HIIT only. Following HIIT, participants completed two 5 km time trials, the first matched identically to pre-intervention trial (ISO time), and a self-paced effort.

Results

Time trial performance was improved in all groups (MASK 3.1 ± 1.7%, IMT, 5.7 ± 1.5% and CON 2.6 ± 1.0%, p < 0.05). IMT improved greater than MASK and CON (p = 0.004). Post intervention, PImax and diaphragm thickness were improved in IMT only (32% and 9.5%, respectively, p = 0.003 and 0.024).

Conclusion

A flow-resistive mask worn during HIIT provides no benefit to 5 km performance when compared to HIIT only. Supplementing HIIT with IMT improves respiratory muscle strength, morphology and performance greater than HIIT alone.
Statistical independence in mathematics–the key to a Gaussian law
Authors: Leobacher Gunther , Prochno Joscha
Published: October 2020

In this manuscript we discuss the notion of (statistical) independence embedded in its historical context. We focus in particular on its appearance and role in number theory, concomitantly exploring the intimate connection of independence and the famous Gaussian law of errors. As we shall see, this at times requires us to go adrift from the celebrated Kolmogorov axioms, which give the appearance of being ultimate ever since they have been introduced in the 1930s. While these insights are known to many a mathematician, we feel it is time for both a reminder and renewed awareness. Among other things, we present the independence of the coefficients in a binary expansion together with a central limit theorem for the sum-of-digits function as well as the independence of divisibility by primes and the resulting, famous central limit theorem of Paul Erdős and Mark Kac on the number of different prime factors of a number $$n\in{\mathbb{N}}$$

n
∈
N

. We shall also present some of the (modern) developments in the framework of lacunary series that have its origin in a work of Raphaël Salem and Antoni Zygmund.