bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereoselective methadone disposition after administration of racemic methadone to anesthetized Shetland ponies assessed by capillary electrophoresis
Authors: Sandbaumhüter Friederike A. , Gittel Claudia , Larenza‐Menzies M. Paula , Theurillat Regula , Thormann Wolfgang , Braun Christina
Published: May 2021

The enantioselectivity of the pharmacokinetics of methadone was investigated in anesthetized Shetland ponies after a single intravenous (0.5 mg/kg methadone hydrochloride; n = 6) or constant rate infusion (0.25 mg/kg bolus followed by 0.25 mg/kg/h methadone hydrochloride; n = 3) administration of racemic methadone. Plasma concentrations of l‐methadone and d‐methadone and their major metabolites, l‐ and d‐2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine (EDDP), respectively, were analyzed by CE with highly sulfated γ‐cyclodextrin as chiral selector and electrokinetic analyte injection from liquid/liquid extracts prepared at alkaline pH. In both trials, the d‐methadone concentrations were lower than those of l‐methadone and the d‐EDDP levels were lower than those of L‐EDDP. For the case of a single intravenous bolus injection, the plasma concentration versus time profile of methadone enantiomers was analyzed with a two‐compartment pharmacokinetic model. l‐methadone showed a slower elimination rate constant, a lower body clearance, and a smaller steady‐state volume of distribution than d‐methadone. d‐methadone and d‐EDDP were eliminated faster than their respective l‐enantiomers. This is the first study that outlines that the disposition of racemic methadone administered to anesthetized equines is enantioselective.
Sulfonation mechanisms of aromatic polymers for PEMFC applications
Authors: Hu Yidong , Yan Liuming , Yue Baohua
Published: May 2021

The sulfonated aromatic polymers are competitive proton conducting materials for proton exchange membrane fuel cells because of their relatively low costs and adequate performances compared with the perfluorinated sulfonic acid ionomers. These polymeric materials can be economically synthesized by the sulfonation of existing aromatic polymers; however, the inadequate sulfonation degree has prevented the further optimization of their overall performances. In order to improve the overall performances of sulfonated aromatic polymeric proton conducting materials, the sulfonation mechanisms of typical aromatic polymers, including bisphenol A type polysulfone (BPA‐PSF), 4,4’‐biphenol type polysulfone (44BP‐PSF), poly(ether ether ketone) (PEEK), and poly(ether sulfone) (PES), are studied in terms of transition states and activation energies using density functional theory calculations with satisfactory results. It is concluded that the sulfonations are favored at the ortho‐position of direct arylene‐arylene linkage and ether bond linkage, but retarded by the bulky sulfonyl linkage, dimethyl methylene linkage, and carbonyl linkage. It is also concluded that the solvation effect from polar solvent reduces the activation barrier more efficiently than that from nonpolar solvent.
Coupled effect of multislips and activation energy in a micropolar nanoliquid on a convectively heated elongated surface
Authors: Katam Malleswari , Ganganapalli Sarojamma , Kata Sreelakshmi , Rayanki Vijayalakshmi , Panyam Venkata Satya Narayana , Kuppalapalle Vajravelu
Published: May 2021

This research communication explores the impact of wall slips along with the suspension of nanomaterials in a chemically reactive micropolar liquid stream on a stretched surface with convective heating. Activation of energy is analyzed through the modified Arrhenius function. Radiative heat flux with nonlinearity and temperature‐dependent thermal source (sink) are considered in the heat transmission process. The Cattaneo–Christov approach featuring the time of thermal relaxation is employed. Successive application of scaling analysis followed by the Runge–Kutta–Fehlberg numerical approach delivered computational solutions for the partial differential equations delineating the problem under study. The response of flow variables for different values of various emerged physical variables is elaborated in detail via graphical and numerical presentations. Comparison of the outcome of the current analysis for certain cases is in accordance with the outcomes available in the literature. The findings reveal that pairs of velocity, microrotation, temperature, and species concentration oppositely reacted to both parameters of slip. The temperature of the nanofluid is improved by 18.5%, for specified values of radiation and temperature ratio parameters over that of the pure base liquid. Activation energy augments concentration. The drag coefficient declines with growing thermal and solutal Grashof numbers. Sherwood number is enhanced for higher values of the temperature difference and chemical reaction parameters.
Key Issues of Organizational Structure and Processes with Feature‐based Product Line Engineering
Authors: Bolander William J. , Clements Paul C.
Published: May 2021

Feature‐Based Product Line Engineering (PLE) is a well‐known approach for efficiently engineering product lines, which numerous case studies have shown to yield substantial benefits in cost, quality, and time to market. This article presents an approach for a necessary ingredient of successful PLE: Handling the temporal dimension, which is concerned with managing artifacts as they change and evolve. The approach relies on a foundation of proven traditional change control techniques but shows how they apply in the context of Feature‐Based PLE.
A comparative study on fabrication techniques of gelable bone matrix derived from porcine tibia
Authors: Li Wuwei , Wang Feilong , Barnett Cleon , Wang Bo
Published: May 2021

Recently, several types of native tissues have been enzymatically digested to prepare hydrogels that have natural‐mimic extracellular matrix (ECM) proteins, architecture, and biologic activities. However, the residual detergents and salts remaining in the hydrogel may cause some undesirable effects on compatibility, functionality, and bioactivity of the material. In this study, we enzymatically digested the demineralized and decellularized bone matrix (DDBM) and adopted two common methods that included dialysis against distilled water and acetone precipitation for sample desalting. Efficiency in salt removal, protein preservation, gelation ability, and in vivo biocompatibility and function were compared to the DDBM digest without a desalting treatment. After lyophilization, the dialyzed, precipitated, and non‐desalted DDBM digests all exhibited cotton‐like texture and were water‐soluble; however, only the precipitated DDBM digest could be gelled. We also found that the method of acetone precipitation could effectively remove salt from the DDBM digest while preserving of multiple proteins from the native bone and internal porous structure. A total of 57 proteins were identified by mass spectrometry in the precipitated DDBM digest and the majority of these proteins are critical to overall protein assembly, scaffold structure and stability, and cell‐activities. Additionally, the precipitated DDBM digest possessed enhanced biocompatibility and osteointegration in repairing a cranial bone defect in Sprague–Dawley (SD) rat. In conclusion, the soluble, biodegradable, and biocompatible natures of the precipitated DDBM digest allow its usage in bone tissue engineering as a protein carrier because of its resemblance to native bone‐like protein composite and operative flexibility.
Barnyard grass [Echinochloa crus‐galli (L.) Beauv] leaves extract against tomato pests
Authors: Castrosanto Melvin A , Alvarez Michael Russelle , Salamanez Kevin C , Nacario Ruel C , Completo Gladys C
Published: May 2021

BACKGROUND

Tomato is one of the widely cultivated crops worldwide that is affected by several pests, such as fungi (Fusarium oxysoporum, Alternaria solani), bacteria (Pectobacterium carotovorum) and weeds (Cyperus iria L., Amaranthus spinosus). A growing interest has emerged for developing plant‐derived pesticidal compounds to counteract these pests. One attractive alternative is to use barnyard grass (Echinochloa crus‐galli), known to be widely resistant to synthetic herbicides, as a potential biopesticide compound source.

RESULTS

Phytochemical screening of the crude extract showed that phenolic compounds were the most abundant component present in barnyard grass. The crude extract was evaluated for antifungal, antibacterial and herbicidal activities. Bioassays showed inhibition against F. oxysporum (10.73 ± 1.30%) and A. solani (20.47 ± 3.51%), the causative agent of Fusarium rot and early blight disease in tomato, respectively. Antibacterial activity against P. carotovorum gave a mean zone of inhibition (paper disc diffusion assay) of 17.00 ± 1.00 mm and an IC50 (dose–response assay) of 2.26 mg mL−1 was observed. Dose–responsive herbicidal activity on the lettuce seed germination bioassay produced an IC50 of 459.30 ppm. Selectivity studies showed inhibition towards C. iria and A. spinosus with no effect on tomato. Lastly, bioassay‐guided fractionation coupled with untargeted metabolomics studies using ultra‐performance liquid chromatography with diode array detection–tandem mass spectrometry mass analyses revealed loliolide and tricin as the putative metabolites present in barnyard grass.

CONCLUSION

To date, this is the first reported study on using barnyard grass as a potential alternative biopesticide against tomato pests such as fungi, bacteria and weeds. © 2021 Society of Chemical Industry.
Statin Therapy and the Incidence of Thromboembolism and Vascular Events Following Liver Transplantation
Authors: Frasco Peter E. , Aqel Bashar , Alvord Jeremy M. , Poterack Karl A. , Bauer Isabel , Mathur Amit K.
Published: May 2021

Statin therapy may reduce the risk of venous thromboembolism (VTE), which may impact solid organ transplant outcomes. We evaluated the incidence of VTE and other complications after liver transplantation stratified by hyperlipidemia status and statin use using a retrospective cohort study approach. We reviewed all primary orthotopic liver transplantation (OLT) records from January 2014 to December 2019 from our center. Intraoperative deaths were excluded. Recipient, donor clinical and demographic data were collected. We developed risk‐adjusted models to assess the effect of statin use on the occurrence of VTE, hepatic artery complications (HACs), graft failure, and death, accounting for clinical covariates and competing risks. A total of 672 OLT recipients were included in the analysis. Of this cohort, 11.9% (n = 80) received statin therapy. A total of 47 patients (7.0%) had VTE events. HACs occurred in 40 patients (6.0%). A total of 42 (6.1%) patients experienced graft loss, whereas 9.1% (n = 61) of the cohort died during the study interval. Eighty OLT recipients (29.8%) were treated with statins. In the statin treated group, 0% of patients had VTE versus 7.9% of those not on statins (P = 0.02). HACs were identified in 1.2% of the statin group and 6.8% of the nonstatin group. Untreated hyperlipidemia was associated with a 2.1‐fold higher risk of HACs versus patients with no hyperlipidemia status (P = 0.05). Statin therapy was associated with significantly better risk‐adjusted thromboembolic event‐free survival (absence of VTE, cerebrovascular accident, myocardial infarction, HACs, and death); hazard ratio, 2.7; P = 0.01. These data indicate that statin therapy is correlated with a lower rate of VTE and HACs after liver transplantation.
Cancer‐Cell‐Derived Hybrid Vesicles from MCF‐7 and HeLa Cells for Dual‐Homotypic Targeting of Anticancer Drugs
Authors: Song Jihyeon , Jung Heesun , You Gayeon , Mok Hyejung
Published: May 2021

Here, as a proof of concept, hybrid vesicles (VEs) are developed from two types of cancer cells, MCF‐7 and HeLa, for the dual targeting of the anticancer drug doxorubicin (Dox) to cancer cells via homotypic interactions. Hybrid VEs with a size of 181.8 ± 28.2 nm and surface charge of −27.8 ± 1.9 mV are successfully prepared by the fusion of MCF‐7 and HeLa VEs, as demonstrated by the fluorescence resonance energy transfer assay. The hybrid VEs exhibit enhanced intracellular uptake both in MCF‐7 and HeLa cells. Dox‐encapsulated hybrid VEs (Dox–hybrid VEs) also exhibit promising anticancer and antiproliferative activities against MCF‐7/multidrug‐resistant cells and HeLa cells. In addition, compared to free Dox, the Dox–hybrid VEs exhibit low intracellular uptake and reduced cytotoxicity for RAW264.7 cells. Thus, hybrid VEs with dual‐targeting activity toward two types of cancer cells may be useful for the specific targeting of anticancer drugs for improved anticancer effects with reduced nonspecific toxicity.
Spectral fitting strategy to overcome the overlap between 2‐hydroxyglutarate and lipid resonances at 2.25 ppm
Authors: Askari Pegah , Dimitrov Ivan E. , Ganji Sandeep K. , Tiwari Vivek , Levy Michael , Patel Toral R. , Pan Edward , Mickey Bruce E. , Malloy Craig R. , Maher Elizabeth A. , Choi Changho
Published: May 2021

Purpose

1H MRS provides a noninvasive tool for identifying mutations in isocitrate dehydrogenase (IDH). Quantification of the prominent 2‐hydroxyglutarate (2HG) resonance at 2.25 ppm is often confounded by the lipid resonance at the same frequency in tumors with elevated lipids. We propose a new spectral fitting approach to separate these overlapped signals, therefore, improving 2HG evaluation.

Methods

TE 97 ms PRESS was acquired at 3T from 42 glioma patients. New lipid basis sets were created, in which the small lipid 2.25‐ppm signal strength was preset with reference to the lipid signal at 0.9 ppm, incorporating published fat relaxation data. LCModel fitting using the new lipid bases (Fitting method 2) was conducted along with fitting using the LCModel built‐in lipid basis set (Fitting method 1), in which the lipid 2.25‐ppm signal is assessed with reference to the lipid 1.3‐ppm signal. In‐house basis spectra of low‐molecular‐weight metabolites were used in both fitting methods.

Results

Fitting method 2 showed marked improvement in identifying IDH mutational status compared with Fitting method 1. 2HG estimates from Fitting method 2 were overall smaller than those from Fitting method 1, which was because of differential assignment of the signal at 2.25 ppm to lipids. In receiver operating characteristic analysis, Fitting method 2 provided a complete distinction between IDH mutation and wild‐type whereas Fitting method 1 did not.

Conclusion

The data suggest that 1H MR spectral fitting using the new lipid basis set provides a robust fitting strategy that improves 2HG evaluation in brain tumors with elevated lipids.
Folded‐end dipole transceiver array for human whole‐brain imaging at 7 T
Authors: Avdievich Nikolai I. , Solomakha Georgiy , Ruhm Loreen , Nikulin Anton V. , Magill Arthur W. , Scheffler Klaus
Published: May 2021

The advancement of clinical applications of ultrahigh field (UHF) MRI depends heavily on advances in technology, including the development of new radiofrequency (RF) coil designs. Currently, the number of commercially available 7 T head RF coils is rather limited, implying a need to develop novel RF head coil designs that offer superior transmit and receive performance. RF coils to be used for clinical applications must be robust and reliable. In particular, for transmit arrays, if a transmit channel fails the local specific absorption rate may increase, significantly increasing local tissue heating. Recently, dipole antennas have been proposed and used to design UHF head transmit and receive arrays. The dipole provides a unique simplicity while offering comparable transmit efficiency and signal‐to‐noise ratio with the conventional loop design. Recently, we developed a novel array design in our laboratory using a folded‐end dipole antenna. In this work, we developed, constructed and evaluated an eight‐element transceiver bent folded‐end dipole array for human head imaging at 7 T. Driven in the quadrature circularly polarized mode, the array demonstrated more than 20% higher transmit efficiency and significantly better whole‐brain coverage than that provided by a widely used commercial array. In addition, we evaluated passive dipole antennas for decoupling the proposed array. We demonstrated that in contrast to the common unfolded dipole array, the passive dipoles moved away from the sample not only minimize coupling between the adjacent folded‐end active dipoles but also produce practically no destructive interference with the quadrature mode of the array.
Effect of dimensionality of nanosized TiO2 embedded in regenerated cellulose beads as a portable catalyst for reusable decomposition system
Authors: Evyan Chia‐Yan Yang , Salleh Kushairi Mohd , Chong Mee Yoke , Chia Chin Hua , Zakaria Sarani
Published: May 2021

Free‐standing titanium dioxide (TiO2) nanowires (TNW) with great photocatalysis performances were formed by using a simple hydrothermal method. Pre‐cool rapid dissolution technique was used to dissolve cellulose, and the regenerated cellulose (RC) beads were used as a portable host for absorption and photocatalytic reaction. Comparisons were made between zero‐dimensional TiO2 nanoparticle (TNP) and one‐dimensional TNW, which both were mixed separately with dissolved cellulose and regenerated into spherical beads. As regeneration involved physical interaction, there were no functional group changes observed on RC beads, as confirmed by Fourier‐transform infrared (FT‐IR) spectroscopy analysis. TNP and TNW maintained the crystallize phase after the regeneration process, thus confirming that aqueous LiOH/urea solvent had no chemical interaction with them. RC beads shaped, external and internal structures were morphologically examined with a field emission scanning electron microscope (FESEM). Due to the distinct dimensionality between TNW and TNP, interactions of physical crosslinking with dissolved cellulose are also different. This leads to different RC beads morphological structures, externally and internally. Changes in pore volume and percentage of weight gain were most prominent with the embedment of TNW. RC beads with TNP (TPB) had better photocatalytic performances than RC beads with TNW (TWB) in the 1st cycle but have poor recyclability in comparison to TWB after the 5th cycle. We concluded that the embedment of one‐dimensional TNW in RC beads promotes better photocatalytic behavior and performance as a portable catalyst.
A rare case of leiomyosarcoma of the inferior vena cava in a 32‐year‐old patient
Authors: Rosenbaum Paulo César , da Silva Boigues Aroldo Henrique , Tassone Fernando Zambelli , Martinhão Isabela , de Melo João Italo Fortaleza , Netto Raphael Oliveira Ramos Franco , Fernandes Victor Augusto Ramos , Mendonça Messias Villa , de Souza Freitas Melo Lindyane , Rocha Castilhos Cindy Liberato , Ferreira Leonardo Gattass , Dutra Luiz Dias
Published: May 2021

Leiomyosarcoma is a malignant tumor that develops from the smooth muscle constituents of the middle layer in veins, usually affecting the inferior vena cava (IVC); however, this disease is observed in older patients. In this report, we describe a rare case of a 32‐year‐old female patient who presented with leiomyosarcoma. Initially, the patient complained of moderate‐intensity pain in the abdominal region of the right hypochondrium and nausea, worsening postprandial starting 6 days earlier. Abdominal ultrasonography showed a heterogeneous hypoechoic expansive formation, with lobulated contours and ill‐defined limits in the projection of the IVC. Inferior vena cavography, showed obliteration of the vessel in almost all of its extensions. Magnetic resonance examination showed a large expansive lesion occupying the IVC. The lesion was resected, and the specimen was sent for anatomopathological analysis, which showed a leiomyosarcoma of the IVC. Patients with leiomyosarcoma have a poor prognosis, and early diagnosis and complete resection with free surgical margins are the only chance of long‐term survival. The report stands out due to the appearance of this condition in a young patient with no family history of this disease or other predisposing carcinogenic pathologies.
High Thermopower and Optical Properties of A2MoS4 (A = K, Rb, Cs) and Cs2MoSe4
Authors: Roy Argha Jyoti , Sharma Vineet Kumar , Kanchana Venkatakrishanan
Published: May 2021

The current work analyzes the electronic, structural, mechanical, thermoelectric (TE), and optical properties of alkali‐based transition metal chalcogenides (A = K, Rb, Cs) and using methods based on first principles. The electronic, structural, and mechanical properties are analyzed using projected augmented wave (PAW) potentials. The electronic structure calculations show them to be direct bandgap semiconductors. From the TE properties, it is found that all the compounds possess huge thermopower especially for the holes, and this along with low lattice thermal conductivity enables us to predict (A = K, Rb, Cs) and to be a good class of material for TE applications. Also, the optical properties are found to be nearly isotropic in the low energy region, which also might fetch potential applications in the visible range. The nearly isotropic optical properties along with giant thermopower are the highlights of the current study, which sets a platform for exploring future device applications.
Associations between beta‐blocker use and psychological distress in bereaved adults with cardiovascular conditions
Authors: Viola Martin , Ouyang Daniel , Xu Jiehui , Maciejewski Paul K. , Prigerson Holly G. , Derry Heather M.
Published: May 2021

The death of a close other is a major life stressor that disrupts mental and physical health. Beta‐blocker medications are indicated treatments for cardiovascular conditions that may also mitigate psychological distress in the context of stressors by reducing adrenergic activity. We sought to examine observational links between beta‐blocker medication use and psychological distress during bereavement. Using publicly available data from the Midlife in the United States Refresher study, we examined associations between beta‐blocker use and general distress, depressive symptoms, and anxiety symptoms (as measured by the Mood and Anxiety Symptom Questionnaire) among bereaved adults with cardiovascular conditions (n = 161) using t‐tests and regression models. Beta‐blocker users reported lower levels of anxiety‐related general distress (b = −2.49, SE = 0.88, p = 0.005) and depression‐related general distress than non‐users (b = −2.39, SE = 1.14, p = 0.039) in multivariate linear regression models adjusting for demographic characteristics, mental health treatments, time since loss and comorbid health conditions. These observed links between beta‐blockers and lower psychological distress in bereavement warrant further investigation in prospective and randomized studies, as beta‐blockers could be a scalable intervention for mitigating distress following loss.
Understanding flavin electronic structure and spectra
Authors: Kar Rajiv K. , Miller Anne‐Frances , Mroginski Maria‐Andrea
Published: May 2021

Flavins have emerged as central to electron bifurcation, signaling, and countless enzymatic reactions. In bifurcation, two electrons acquired as a pair are separated in coupled transfers wherein the energy of both is concentrated on one of the two. This enables organisms to drive demanding reactions based on abundant low‐grade chemical fuel. To enable incorporation of this and other flavin capabilities into designed materials and devices, it is essential to understand fundamental principles of flavin electronic structure that make flavins so reactive and tunable by interactions with protein. Emerging computational tools can now replicate spectra of flavins and are gaining capacity to explain reactivity at atomistic resolution, based on electronic structures. Such fundamental understanding can moreover be transferrable to other chemical systems. A variety of computational innovations have been critical in reproducing experimental properties of flavins including their electronic spectra, vibrational signatures, and nuclear magnetic resonance (NMR) chemical shifts. A computational toolbox for understanding flavin reactivity moreover must be able to treat all five oxidation and protonation states, in addition to excited states that participate in flavoprotein's light‐driven reactions. Therefore, we compare emerging hybrid strategies and their successes in replicating effects of hydrogen bonding, the surrounding dielectric, and local electrostatics. These contribute to the protein's ability to modulate flavin reactivity, so we conclude with a survey of methods for incorporating the effects of the protein residues explicitly, as well as local dynamics. Computation is poised to elucidate the factors that affect a bound flavin's ability to mediate stunningly diverse reactions, and make life possible.

This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics

Electronic Structure Theory > Combined QM/MM Methods

Theoretical and Physical Chemistry > Spectroscopy
Flips, dualities and symmetry enhancements
Authors: Hwang Chiung , Pasquetti Sara , Sacchi Matteo
Published: May 2021

Abstract

We present various 4d $$ \mathcal{N} $$
N
= 1 theories enjoying IR global symmetry enhancement. The models we consider have the USp(2N) gauge group, 8 fundamental, one antisymmetric chirals and various numbers of gauge singlets. By suitably turning on superpotential deformations involving the singlets which break part of the UV symmetry we flow to SCFTs with E6, SO(10), SO(9), SO(8) and F4 IR global symmetry. We explain these patterns of symmetry enhancement following two arguments due to Razamat, Sela and Zafrir. The first one involves the study of the relations satisfied by marginal operators, while the second one relies on the existence of self-duality frames.
Counterexample-guided inductive synthesis for probabilistic systems
Authors: Češka Milan , Hensel Christian , Junges Sebastian , Katoen Joost-Pieter
Published: May 2021

This paper presents counterexample-guided inductive synthesis (CEGIS) to automatically synthesise probabilistic models. The starting point is a family of finite-stateMarkov chains with related but distinct topologies. Such families can succinctly be described by a sketch of a probabilistic program. Program sketches are programs containing holes. Every hole has a finite repertoire of possible program snippets by which it can be filled.We study several synthesis problems—feasibility, optimal synthesis, and complete partitioning—for a given quantitative specification

φ

. Feasibility amounts to determine a family member satisfying

φ

, optimal synthesis amounts to find a family member that maximises the probability to satisfy

φ

, and complete partitioning splits the family in satisfying and refuting members. Each of these problems can be considered under the additional constraint of minimising the total cost of instantiations, e.g., what are all possible instantiations for

φ

that are within a certain budget? The synthesis problems are tackled using a CEGIS approach. The crux is to aggressively prune the search space by using counterexamples provided by a probabilistic model checker. Counterexamples can be viewed as sub-Markov chains that rule out all family members that share this sub-chain. Our CEGIS approach leverages efficient probabilisticmodel checking,modern SMT solving, and programsnippets as counterexamples. Experiments on case studies froma diverse nature—controller synthesis, program sketching, and security—show that synthesis among up to a million candidate designs can be done using a few thousand verification queries.
Meditation affects word recognition of meditation novices
Authors: Lusnig Larissa , Radach Ralph , Hofmann Markus J.
Published: May 2021

This work represents one of the first attempts to examine the effects of meditation on the processing of written single words. In the present longitudinal study, participants conducted a lexical decision task and rated the affective valence of nouns before and after a 7-week class in mindfulness meditation, loving-kindness meditation, or a control intervention. Both meditation groups rated the emotional valence of nouns more neutral after the interventions, suggesting a general down-regulation of emotions. In the loving-kindness group, positive words were rated more positively after the intervention, suggesting a specific intensification of positive feelings. After both meditation interventions, response times in the lexical decision task accelerated significantly, with the largest facilitation occurring in the loving-kindness group. We assume that meditation might have led to increased attention, better visual discrimination, a broadened attentional focus, and reduced mind-wandering, which in turn enabled accelerated word recognition. These results extend findings from a previous study with expert Zen meditators, in which we found that one session of advanced meditation can affect word recognition in a very similar way.
Trading offspring for survival: high duckweed cover decreases reproductive potential and stimulates elongation in the submerged macrophyte Chara globularis Thuillier
Authors: Van Onsem Stijn , Triest Ludwig
Published: May 2021

Compact blankets of free-floating plants generate stressful aquatic environments. The response of submerged macrophytes remains largely elusive. Will they rush toward the light or rather speed up reproductive efforts and escape using propagules—the macrophyte equivalent of lifeboats? We studied the effects of complete duckweed (Lemna minor) cover on growth and reproductive fitness of macroalgaChara globularisin a pond mesocosm experiment.C. globularisgrowing inLemna-covered plots lost biomass and developed longer internodes, indicating an elongative reflex to escape stress. Densities of reproductive organs per biomass unit evolved positively in open plots and negatively in covered plots, suggesting a trade-off between reproductive effort and vegetative elongation. Reproductive potential correlated significantly with incident radiation.Lemnacover, however, did not affect oospore rain—at least within the limited time span of propagule trapping.C. globularisthus displayed an ability to modify phenology in response to floating plant stress, allocating resources to internodes instead of gametangia. Nevertheless, duckweed dominance clearly suppressed the overall reproductive performance ofC. globularis. The regenerative capacity of many submerged macrophytes will likely suffer from increased floating plant dominance due to global warming—unless efforts are made to reduce nutrient levels in vulnerable waterbodies.
Towards an enriched framework of service evaluation for pedestrian and bicyclist infrastructure: acknowledging the power of users’ perceptions
Authors: Rodriguez-Valencia Alvaro , Vallejo-Borda Jose Agustin , Barrero German A. , Ortiz-Ramirez Hernan Alberto
Published: May 2021

More and more cities worldwide are striving for sustainability and livability. Measuring the service or performance of local-scale spaces for pedestrians and bicyclists to better understand how to provide “walkable” and “bikeable” environments is key in this endeavor to enhance active transportation. These pedestrian and bicycle service or performance indicators, such as Level of Traffic Stress or Level of Service, relate measurable characteristics with a perceived proxy of the performance or service, such as comfort, satisfaction, or quality of service (QoS). The purpose of this study is to propose and validate a framework that integrates user-oriented inputs to the existing traditional supply-oriented variables to explain the QoS in segment roadways in urban environments for active modes. The conceptual framework underlying this study considers the contribution of individual perceptions, in addition to the traditionally considered operational and geometry variables, to explain the perceived QoS of pedestrian and bicyclist infrastructure. The framework is tested via two separate and independent surveys for pedestrians and bicyclists. Evidence determined the relative importance of these supply-oriented and user-oriented factors to explain the QoS. The superior explanatory power of the perception variables and in terms of the variables that explain the individuals’ perceived QoS justify the framework for both pedestrians and bicyclists.
Food security and food quality among vanilla farmers in Madagascar: the role of contract farming and livestock keeping
Authors: Andriamparany Jessica Noromalala , Hänke Hendrik , Schlecht Eva
Published: May 2021

The northeastern SAVA region of Madagascar is the largest vanilla producing area in the world and is flourishing due to a large global demand for natural vanilla. Although the general socio-economic situation has regionally improved because of high vanilla prices, little is known about the nutritional status of local vanilla farmers. We used a 12-month longitudinal food survey to analyze food security, food consumption and nutrient intake of local vanilla farming households (n = 140). Food consumption data was complemented with baseline, agro-economic, longitudinal and field-plot information to determine factors influencing food security, and the contribution of protein from Animal Source Food (ASF_protein) to household nutrition using a stepwise generalized linear model. Results show a high level (74%) of food insecurity and micronutrient deficiency but an acceptable level of protein intake among surveyed households. Consumption of rice, the principal source of carbohydrates, is stable across the year. Compared to other regions in Madagascar, local diets are moderately diversified with an acceptable share of ASF_protein (about 50%). Household size (P < 0.001) and cash income from rice sales (P < 0.001) were the most important factors influencing the food security index (FSI), while cash crop income (P < 0.01) and number of income sources (P < 0.01) were more important in the explanation of the dietary share of ASF_protein. Yet, neither livestock ownership nor contracting with vanilla buyers/exporters did improve food security of the surveyed households. Households who concluded contracts were significantly less food secure than non-contracting households (P = 0.01) with seasonal fluctuations across the year. Policy implications of our findings are that, although many actors of the vanilla value chain run social and environmental programs in the SAVA region, more needs to be done to improve diet quality at household level and strengthen farmers’ resilience to food insecurity.
Wie in Mathe so auch in Kunst? Zur Konzeption von Unterrichtsqualität im Kunstunterricht
Authors: Rakoczy Katrin , Wagner Ernst , Frick Ulrich
Published: May 2021

Die Frage, was guten Kunstunterricht ausmacht, stellt zwar eine der zentralen Fragen der Kunstpädagogik dar, wurde bisher jedoch kaum (quantitativ) empirisch untersucht. Im vorliegenden Beitrag werden Erkenntnisse aus der allgemeinen Unterrichtsqualitätsforschung für die Konzeption von Qualität im Kunstunterricht genutzt, indem die Dimensionen des Syntheseframeworks von Praetorius und Charalambous (2018) mit zwei zentralen kunstdidaktischen Ansätzen abgeglichen werden. Die Gegenüberstellung der aus kunstdidaktischer Sicht relevanten Unterrichtsmerkmale mit dem Syntheseframework spricht für eine grundsätzliche Eignung der aus Kernfächern bekannten Qualitätsdimensionen für den Kunstunterricht. Sie macht jedoch auch deutlich, dass eine fachspezifische Überarbeitung und Ausdifferenzierung der Dimensionen unter Berücksichtigung der Vielschichtigkeit und Komplexität des Lernprozesses notwendig ist. Es wird dargelegt, dass sich die fachspezifische Gestaltung und Ausdifferenzierung sowohl auf die Erweiterung einer Dimension (z. B. „Kognitive und emotionale Aktivierung“ statt „kognitiver Aktivierung“) beziehen kann als auch auf eine unterschiedliche Schwerpunktsetzung innerhalb einer Dimension (z. B. bedeutet Klassenführung im Kunstunterricht nicht die exakte Einhaltung einer genauen Unterrichtsplanung, sondern eher die Schaffung einer kreativitätsfördernden Atmosphäre).
Analysis of fractality and complexity of the planetary K-index
Authors: Chattopadhyay Anirban , Chandra Aniruddha , Khondekar Mofazzal H. , Bhattacharjee Anup Kumar
Published: May 2021

The objective of this research is to explore the inherent complexities and multifractal properties of the underlying distributions in the daily Planetary K-index time series collected from NOAA Space Weather Prediction Center. In this article, non-stationary and nonlinear characteristics of the signal have been explored using Smoothed Pseudo Wigner–Ville Distribution and Delay Vector Variance algorithms, respectively, while Recurrence Plot, 0–1 test, Recurrence Quantification Analysis and correlation dimension analysis have been applied to confirm and measure the chaos in the signal under consideration. Multifractal detrending moving average has been used to evaluate the multifractality and also recognise the singularities of the signal. The result of these analyses validates the nonstationary and nonlinear characteristics of the Planetary K-index signal, while a significant presence of deterministic chaos in it has also been noticed. It has also been confirmed that the Planetary K-index exhibits multifractal nature with positive persistence. The long-range temporal association and also the large pdf are discovered to be the primary factors that contribute to the multifractal behaviour of the Kp-index.
Using storytelling to unpack resilience theory in accordance with an internationally recognised resilience framework with primary school children
Authors: Tillott Sarah , Weatherby-Fell Noelene , Pearson Phil , Neumann Michelle M.
Published: May 2021

Resilience can be a protective trait to promote mental health when implemented in the early years. This study explored the use of storytelling to foster children’s learning of resilience. A pedagogically appropriate storybook was used to facilitate and embed the skills of resilience in children at primary school. Teachers ( n = 2) and community-based sports officers ( n = 2) read the storybook to children enrolled in Kindergarten (first formal year of schooling) ( n = 20), Year 1 ( n = 20) and Year 2 ( n = 20). The total number in the participant group was 60, aged 4–8 years old. Following the initial reading, teachers continued to deliver the storybook to children over a 4-week intervention period. All participants were interviewed about their perceptions of the storybook, and their responses were coded into key themes mapped by the Grotberg Resilience Framework. Results indicated that storytelling as a tool provided children with positive resilience-based behavioural intervention opportunities.
Objective structured assessment of technical skill in temporal bone dissection: validation of a novel tool
Authors: Stavrakas M , Menexes G , Triaridis S , Bamidis P , Constantinidis J , Karkos P D
Published: May 2021

Objective

This study developed an assessment tool that was based on the objective structured assessment for technical skills principles, to be used for evaluation of surgical skills in cortical mastoidectomy. The objective structured assessment of technical skill is a well-established tool for evaluation of surgical ability. This study also aimed to identify the best material and printing method to make a three-dimensional printed temporal bone model.

Methods

Twenty-four otolaryngologists in training were asked to perform a cortical mastoidectomy on a three-dimensional printed temporal bone (selective laser sintering resin). They were scored according to the objective structured assessment of technical skill in temporal bone dissection tool developed in this study and an already validated global rating scale.

Results

Two external assessors scored the candidates, and it was concluded that the objective structured assessment of technical skill in temporal bone dissection tool demonstrated some main aspects of validity and reliability that can be used in training and performance evaluation of technical skills in mastoid surgery.

Conclusion

Apart from validating the new tool for temporal bone dissection training, the study showed that evolving three-dimensional printing technologies is of high value in simulation training with several advantages over traditional teaching methods.
Filling the Data Gaps Within GRACE Missions Using Singular Spectrum Analysis
Authors: Yi Shuang , Sneeuw Nico
Published: May 2021

Dozens of missing epochs in the monthly gravity product of the satellite mission Gravity Recovery and Climate Experiment (GRACE) and its follow‐on (GRACE‐FO) mission greatly inhibit the complete analysis and full utilization of the data. Despite previous attempts to handle this problem, a general all‐purpose gap‐filling solution is still lacking. Here we propose a non‐parametric, data‐adaptive and easy‐to‐implement approach—composed of the Singular Spectrum Analysis gap‐filling technique, cross‐validation, and spectral testing for significant components—to produce reasonable gap‐filling results in the form of spherical harmonic coefficients (SHCs). We demonstrate that this approach is adept at inferring missing data from long‐term and oscillatory changes extracted from available observations. A comparison in the spectral domain reveals that the gap‐filling result in the same signal intensity as the product of GRACE missions for spherical harmonic degrees below 30. As the degree increases above 30, the degree variance of the gap‐filling result decreases more rapidly than that of GRACE/GRACE‐FO SHCs, demonstrating effective suppression of noise. As a result, our approach can reduce noise in the oceans without sacrificing resolutions on land. The quality of the gap‐filling product is evaluated through comparison with a surface mass balance based estimate in Greenland, Swarm gravity solutions and a climate‐driven water storage model, all of which confirm the good performance of our results. This study makes a ready‐to‐use gap‐filling product in the form of SHCs together with proper error estimates available. Nonetheless, our method is also applicable to smoothed gridded observations.
Soil Microbes Transform Inorganic Carbon Into Organic Carbon by Dark Fixation Pathways in Desert Soil
Authors: Liu Zhen , Sun Yanfei , Zhang Yuqing , Feng Wei , Lai Zongrui , Qin Shugao
Published: May 2021

Soil inorganic carbon (SIC) represents the main soil carbon pool in drylands with a high geologic residence time for carbon sequestration. Recent studies have shown that SIC is not stable as previously supposed, and can be employed by certain microbes and transformed into organics in soils; however, this transformation remains largely unexplored. We performed in situ 13C tracing in desert bulk soil and employed metagenomics to predict the microbial metabolic processes associated with carbon transformation. The tracing data showed that the 13C signature profile in soil organic carbon (SOC) originated from SIC with a carbon transformation content of 6.881 mg m−2 during the feeding periods, corresponding to a rate of 3.276 μg kg−1 d−1. Metagenomic analysis identified genes encoding enzymes related to microbial CO2 and fixation, accounting for 0.448% (based on Kyoto Encyclopedia of Genes and Genomes database) and 0.668% (based on Evolutionary genealogy of genes: Non‐supervised Orthologous Groups database) of all ascertained genes. Soil microbes, from a broad taxonomic range, harboring these genes mainly contributed toward chemoautotrophic and heterotrophic carbon fixation. Our results demonstrated that the microbes employed the chemoautotrophic and heterotrophic pathways, namely, dark microbial pathways, for SIC transformation into SOC. Although the amount of SOC derived from the dark microbial fixation process was not assessed, the present study highlights a neglected carbon transformation process mediated by soil microbes in drylands and provides insights into carbon transformation of SIC to SOC in dryland soil.
The Role of Spatial Gradient on Vertical Total Electron Content Extraction From Geodetic Very Long Baseline Interferometry Observation: Case Study CONT08 to CONT17‐L1
Authors: Etemadfard Hossein , Heinkelmann Robert , Hossainali Masoud Mashhadi , Schuh Harald
Published: May 2021

Geodetic very long baseline interferometry (VLBI) observations are carried out, with the legacy system, using two well‐separated frequency bands in order to determine first‐order ionospheric delay corrections corresponding to the combined effect of total electron content (TEC) at two stations forming a baseline. On the other hand, it is possible to obtain the vertical TEC (VTEC) above the VLBI antennas from VLBI data. This research intends to investigate the role of the ionospheric spatial gradient on VTEC which is derived from VLBI observations based on the latest four Continuous VLBI Campaigns (CONT08 to CONT17‐L1). For this purpose, station‐based VTEC values were computed in two modes, with and without spatial gradients. Then, these two approaches were evaluated by comparison to global ionospheric maps (GIMs). The differences between the GIM‐based VTEC values and the VLBI VTEC values derived using two parameterization approaches were used to compute the Root Mean Square Error (RMSE) for each VLBI station during the CONTs. In addition, the improvement percentages of the VLBI VTEC's error were calculated to understand the spatial gradient role. Based on the obtained results, the role of spatial gradient is more significant on the equatorial region as compared to the polar area. Using the ionospheric spatial gradient decreases the RMSE values of VLBI‐derived VTEC values from CONT08, CONT11, CONT14, and CONT17‐L1 by 26.4%, 37.6%, 32.4%, and 27.4%, respectively. In addition, it is also shown that this parameter reduces the RMSE values during the high solar activity, as in 2011 and 2014.
First Worldwide View of a Key Phytoplankton Proxy
Authors: Stanley Sarah
Published: May 2021

New insights into the dynamics of ocean features known as deep chlorophyll maxima set the stage for better understanding of their role in carbon cycling.
Creating heralded hyper-entangled photons using Rydberg atoms
Authors: Ghosh Sutapa , Rivera Nicholas , Eisenstein Gadi , Kaminer Ido
Published: May 2021

Entangled photon pairs are a fundamental component for testing the foundations of quantum mechanics, and for modern quantum technologies such as teleportation and secured communication. Current state-of-the-art sources are based on nonlinear processes that are limited in their efficiency and wavelength tunability. This motivates the exploration of physical mechanisms for entangled photon generation, with a special interest in mechanisms that can be heralded, preferably at telecommunications wavelengths. Here we present a mechanism for the generation of heralded entangled photons from Rydberg atom cavity quantum electrodynamics (cavity QED). We propose a scheme to demonstrate the mechanism and quantify its expected performance. The heralding of the process enables non-destructive detection of the photon pairs. The entangled photons are produced by exciting a rubidium atom to a Rydberg state, from where the atom decays via two-photon emission (TPE). A Rydberg blockade helps to excite a single Rydberg excitation while the input light field is more efficiently collectively absorbed by all the atoms. The TPE rate is significantly enhanced by a designed photonic cavity, whose many resonances also translate into high-dimensional entanglement. The resulting high-dimensionally entangled photons are entangled in more than one degree of freedom: in all of their spectral components, in addition to the polarization—forming a hyper-entangled state, which is particularly interesting in high information capacity quantum communication. We characterize the photon comb states by analyzing the Hong-Ou-Mandel interference and propose proof-of-concept experiments.