bluuebunny/crossref_metadata_2025 huggingface dataset:
HST/WFC3 transmission spectroscopy of the cold rocky planet TRAPPIST-1h
Authors: Garcia L. J. , Moran S. E. , Rackham B. V. , Wakeford H. R. , Gillon M. , de Wit J. , Lewis N. K.
Published: April 2022

Aims. TRAPPIST-1 is a nearby ultra-cool dwarf star transited by seven rocky planets. We observed three transits of its outermost planet, TRAPPIST-1h, using the G141 grism of the Wide Field Camera 3 instrument aboard the Hubble Space Telescope to place constraints on its potentially cold atmosphere.

Methods. In order to deal with the effect of stellar contamination, we model TRAPPIST-1 active regions as portions of a cooler and a hotter photosphere, and generate multi-temperature models that we compare to the out-of-transit spectrum of the star. Using the inferred spot parameters, we produce corrected transmission spectra for planet h under five transit configurations and compare these data to planetary atmospheric transmission models using the forward model CHIMERA.

Results. Our analysis reveals that TRAPPIST-1h is unlikely to host an aerosol-free H/He-dominated atmosphere. While the current data precision limits the constraints we can put on the planetary atmosphere, we find that the likeliest scenario is that of a flat, featureless transmission spectrum in the WFC3/G141 bandpass due to a high mean molecular weight atmosphere (≥1000 × solar), no atmosphere, or an opaque aerosol layer, all in absence of stellar contamination. This work outlines the limitations of modeling active photospheric regions with theoretical stellar spectra, and those brought by our lack of knowledge of the photospheric structure of ultracool dwarf stars. Further characterization of the planetary atmosphere of TRAPPIST-1h would require higher precision measurements over wider wavelengths, which will be possible with the James Webb Space Telescope.
Discovery of new TESS pulsating hot subdwarfs
Authors: Krzesinski J. , Balona L. A.
Published: April 2022

Aims. This work is dedicated to a search for new pulsating hot subdwarfs in TESS photometric data which could have been missed in previous searches.

Methods. By matching catalogues of hot subdwarfs with TESS targets and using luminosities from Gaìa parallaxes, a list of 1389 candidate hot subdwarfs observed by TESS was created. The periodograms of these stars were inspected, and the stars were classified according to variability type.

Results. An updated catalogue of all known pulsating hot subdwarfs is presented. A number of probable pulsating binaries have been identified, which might prove useful for verifying the asteroseismic masses. The mean masses of p- and g-mode pulsators are estimated from the stellar parameters.

Conclusions. A list of 63 previously unknown pulsating hot subdwarfs observed by TESS is presented. More than half of the stars previously identified as pure p-mode pulsators are found to have frequencies in the g-mode region as well. As a result, hybrid p- and g-mode pulsators occur over the whole instability strip.
Shaping the topology of a single phase BLDC motor for reduced cogging torque and improved performance
Authors: Petkovska Lidija , Lefley Paul , Cvetkovski Goga
Published: April 2022

In the paper is presented a step-by-step development of the topology for a novel single phase permanent magnet (PM) brushless DC (BLDC) motor, aiming to improve its operation with more efficient utilisation of the active materials. The studied motor is based on a generic design, where asymmetrical stator poles and respective shaping of the permanent magnets is applied. Accurate 2D finite element simulations were employed for numerical prototyping of the motor design, until the expected results were obtained. Based on FEA, cogging and static torque waveforms, along with other relevant performance characteristics were determined and examined. The results show that the motor topology, and in particular, the detailed shape of the stator poles has the most important impact on the smooth operation of the single phase BLDC permanent magnet motor.
Umgang mit Todeswünschen in der Palliativversorgung – Evaluation eines Schulungsprogramms
Authors: Boström Kathleen , Dojan Thomas , Frerich Gerrit , Romotzky Vanessa , Galushko Maren , Voltz Raymond , Kremeike Kerstin
Published: April 2022

Ziel der Studie Mitarbeitende der Palliativversorgung werden oft mit Todeswünschen von Patient*innen konfrontiert und berichten Unsicherheiten im Umgang damit. Daher wurden Schulungen zum Thema durchgeführt und evaluiert.

Methodik Teilnehmende der zweitägigen Schulungen beantworteten davor (t0), danach (t1) und 1 Jahr später (t2) Fragen zu ihrem Umgang mit Todeswünschen, zu t1 außerdem Fragen zur Schulung. Eine Subgruppe wurde zu t2 zu qualitativen Interviews eingeladen.

Ergebnisse An 12 Schulungen nahmen 102 Versorgende teil. Die Selbsteinschätzung zum Umgang mit Todeswünschen verbesserte sich nach den Schulungen konstant und signifikant – vor allem bei den Versorgenden, die Gespräche über Todeswünsche führten. Die qualitativen Daten geben Hinweise auf Gründe dafür.

Schlussfolgerung Die entwickelten Schulungen können Versorgenden nachhaltig mehr Selbstsicherheit im Umgang mit Todeswünschen und eine Grundlage für offene Gespräche bei Anfragen nach (ärztlich) assistiertem Suizid vermitteln.
Ungewöhnliche Ursache einer Hyperkalzämie in der Schwangerschaft
Authors: Mehl Lisa , Schrader Jörg , Winterberg Torsten , Daniels Thies , Gross Andreas , Weidner Ulrike , Clauditz Till Sebastian , Lock Guntram
Published: April 2022

Hintergrund In der Schwangerschaft diagnostizierte neuroendokrine Tumoren (NET) sind eine absolute Rarität. Die vorliegende Kasuistik beschreibt Diagnostik und Therapie eines im 2. Trimenon symptomatisch gewordenen metastasierten NET des Pankreas.

Fallbeschreibung Eine 33-jährige Patientin stellte sich in der 19. Schwangerschaftswoche (SSW) mit persistierender Diarrhoe in der Notaufnahme vor. Laborchemisch fiel eine ausgeprägte Hyperkalzämie (3,53 mmol/l) auf. In der Bildgebung fand sich eine Raumforderung im Bereich des Pankreaskorpus/-schwanzes mit ausgedehnter Lebermetastasierung. Histologisch zeigte sich ein NET (G2, SSTR-positiv) mit einer paraneoplastischen Parathormon-related-Peptide-Sekretion als Ursache der Hyperkalzämie. Unter einer Therapie mit Octreotid normalisierte sich das Kalzium, die Diarrhoe sistierte. Nach Geburt eines gesunden Kindes (32. SSW per sectio) fand sich ein Progress; der Pankreastumor wurde komplett entfernt, die Leberfiliae so weit wie möglich. In einem postoperativen CT zeigten sich verbliebene metastasensuspekte Läsionen, eine palliative Therapie mit Lanreotid wurde eingeleitet. Darunter ist die Patientin seit einem Jahr symptomfrei, das Serumkalzium blieb normwertig. Das Kind entwickelte sich unauffällig.

Diskussion Dieser ungewöhnliche Fall zeigt, dass es auch bei ausgedehnt metastasierten symptomatischen NETs in der Schwangerschaft weitreichende diagnostische und therapeutische Optionen geben kann, die in enger interdisziplinärer Zusammenarbeit unter sorgfältiger Risiko-Nutzen-Abwägung für Mutter und Kind eine Fortführung der Schwangerschaft erlauben.
Nahtaneurysmen - Ätiopathogenese, Symptomatologie, Diagnostik,
Therapie, Outcome und Einflussfaktoren nach offen gefäßchirurgischer und
interventioneller Rekonstruktion
Authors: Romancik Peter , Meyer Frank , Redlich Ulf , Halloul Zuhir , Tautenhahn Jörg
Published: April 2022

Hintergrund Die über die letzten Jahre/Jahrzehnte ausgebaute und
optimierte gefäßchirurgische Grundversorgung hat auch das Fallaufkommen von
Sekundärkomplikationen wie das Nahtaneurysma (NA) wesentlich erhöht.

Ziel Darstellung der sekundären Versorgungsdiagnose NA in ihrem/r
Fallaufkommen, Ätiopathogenese, Symptomatologie, Diagnostik,
periinterventionellem/-operativem Management und Outcome, basierend auf
selektiven Referenzen der medizinisch-wissenschaftlichen Literatur und eigenen
klinischen Versorgungserfahrungen.

Methode Narratives Review

Ergebnisse

Schlussfolgerung Das NA als relevante Versorgungsgröße ist inzwischen
längst mit in den Fokus eines basalen gefäßchirurgischen/-interventionellen
Betreuungsprofils gerückt, dem sich der Gefäßchirurg/-interventionalist aufgrund
der bestehenden Herausforderung hinsichtlich des anspruchsvollen diagnostischen
und therapeutischen Managements mit seiner ganzen fachspezifischen Kompetenz
widmen muss.
Suizidalität aus toxikologischer Sicht
Authors: Geith Stefanie , Eyer Florian
Published: April 2022

Das Wissen um Charakteristika suizidal intendierter Selbstvergiftungen sowie Faktoren, die mit einem wiederholten Suizidversuch assoziiert sind, ist für die Identifikation von potenziellen Risikopatienten und -konstellationen wertvoll. Daher wurden in einer prospektiven Beobachtungsstudie in einem Zeitraum von 12 Monaten Daten von 1238 Patienten mit suizidalen Intoxikationen, zu denen unser Giftnotruf kontaktiert wurde, gesammelt und ausgewertet. Die erhobenen Informationen umfassen neben demografischen Daten auch Angaben zu Symptomen, eingenommenen Substanzen bzw. deren Quelle, somatisch-psychiatrischen Komorbiditäten, früheren Suizidversuchen, Vorliegen einer Substanzkonsumstörung sowie einer Koingestion von Alkohol oder illegalen Drogen.

53 % der Patienten waren zwischen 18 und 44 Jahre alt, 66 % waren weiblich. 79 % der Patienten litten an einer psychiatrischen Erkrankung, 45 % hatten mindestens einen Suizidversuch hinter sich. Patienten mit einer psychiatrischen Störung nahmen am häufigsten Antidepressiva und Neuroleptika ein, während Patienten ohne psychiatrische Vorerkrankung vorwiegend periphere Analgetika, insbesondere Ibuprofen, verwendeten. Im Vergleich zu Patienten mit einem Erstereignis wiesen diejenigen mit einem wiederholten Suizidversuch häufiger eine psychiatrische Erkrankung oder eine Substanzkonsumstörung auf und ingestierten bevorzugt Antidepressiva und Neuroleptika, jedoch seltener periphere Analgetika. Neben der Identifikation von Charakteristika vorsätzlicher Selbstvergiftungen konnten mit dem Vorliegen einer psychiatrischen Erkrankung, eines gestörten Substanzgebrauchs sowie der Ingestion von Antidepressiva oder Neuroleptika Risikofaktoren für einen wiederholten Suizidversuch detektiert werden, auf deren Basis individuelle Präventivmaßnahmen für Risikogruppen entwickelt werden können.
Manipulating image luminance to improve eye gaze and verbal behavior in autistic children
Authors: Boyd LouAnne , Berardi Vincent , Hughes Deanna , Cibrian Franceli , Johnson Jazette , Sean Viseth , DelPizzo-Cheng Eliza , Mackin Brandon , Tusneem Ayra , Mody Riya , Jones Sara , Lotich Karen
Published: April 2022

Autism has been characterized by a tendency to attend to the local visual details over surveying an image to understand the gist–a phenomenon called local interference. This sensory processing trait has been found to negatively impact social communication. Although much work has been conducted to understand these traits, little to no work has been conducted to intervene to provide support for local interference. Additionally, recent understanding of autism now introduces the core role of sensory processing and its impact on social communication. However, no interventions to the end of our knowledge have been explored to leverage this relationship. This work builds on the connection between visual attention and semantic representation in autistic children. In this work, we ask the following research questions: RQ1: Does manipulating image characteristics of luminance and spatial frequency increase likelihood of fixations in hot spots (Areas of Interest) for autistic children? RQ2: Does manipulating low-level image characteristics of luminance and spatial frequency increase the likelihood of global verbal responses for autistic children? We sought to manipulate visual attention as measured by eye gaze fixations and semantic representation of verbal response to the question “What is this picture about?”. We explore digital strategies to offload low-level, sensory processing of global features via digital filtering. In this work, we designed a global filter to reduce image characteristics found to be distracting for autistic people and compared baseline images to featured images in 11 autistic children. Participants saw counterbalanced images way over 2 sessions. Eye gaze in areas of interest and verbal responses were collected and analyzed. We found that luminance in non-salient areas impacted both eye gaze and verbal responding–however in opposite ways (however versus high levels of luminance). Additionally, the interaction of luminance and spatial frequency in areas of interest is also significant. This is the first empirical study in designing an assistive technology aimed to augment global processing that occurs at a sensory-processing and social-communication level. Contributions of this work include empirical findings regarding the quantification of local interference in images of natural scenes for autistic children in real-world settings; digital methods to offload global visual processing to make this information more accessible via insight on the role of luminance and spatial frequency in visual perception of and semantic representation in images of natural scenes.
Mesogels control volume to explore the glass transition
Authors: Piccone Ashley
Published: April 2022

Suspending colloidal particles in solution with thermosensitive hydrogel spheres allows for study of the liquid and solid conditions in glass-forming suspensions
Numerical study on flow and wear characteristics of dense fine particle solid–liquid two-phase flow in centrifugal pump
Authors: Wang Yanping , Tao Ruilin , Han Chuanfeng , Li Weiqin , He Tielin , Zhu Zuchao
Published: April 2022

The solid–liquid two-phase centrifugal pump is one of the core power equipment of solid phase material hydraulic transportation, widely used in hydraulic engineering, petrochemical industry, marine metal mineral exploitation, urban sewage treatment, and other sectors of the national economy. There is a significant increase in the need to transport dense fine particle slurry in industrial production. Under this condition, the influence of particle parameters on the performance of the centrifugal pump is still not clear. In order to study the flow and wear characteristics of dense fine particle solid–liquid two-phase transported by an open impeller centrifugal pump, the Re-Normalization Group k − ε and dense discrete phase models in Fluent were used to describe the characteristics of the solid–liquid two-phase flow. The numerical model is validated with the experimental data of the pump’s performance. The study indicates that the particle size and concentration have great influence on the wear of the impeller. The wear of the blade pressure surface is the most serious. With the increase of particle concentration and size, the wear area expands to the leading edge and the upper surface of the blade. These results can provide supporting theories for the design of a dense fine particle solid–liquid two-phase medium conveying pump.
Effects of hole arrangement and trenched hole on multirow film cooling
Authors: Wang Wen , Cui Jiahuan , Qu Shaoxing
Published: April 2022

Multirow film cooling is an advanced cooling method to provide effective surface cooling for gas turbine components exposed to high temperature. In this paper, the performance of multirow film cooling under different configurations is investigated numerically. The geometrical parameters, including the hole arrangement, hole orientation, and trenched hole, are considered. The numerical setup is validated before the performances of different cooling configurations are compared. The flow and heat transfer characteristics of the various cooling configurations are analyzed, and the different row-to-row interactions are revealed. For the configurations with standard holes, the staggered arrangement of simple angle holes achieves better cooling efficiency than the counterpart with inline configuration, while the inline arrangement with opposite compound angle holes provides the best cooling efficiency. For the configurations with trenched holes, the trench promotes the coolant uniform mixing, and the coolant stays more close to the effusion plate. Thus, the multirow cooling efficiency with trenched holes is better than the cooling configurations with standard holes.
Study on preparation and mechanism of organic montmorillonite with different functional groups
Authors: Liu Qingxin , Wu Limei , Wang Xiaolong , Hu Ling , Gao Lili , Hu Yuanbiao , Tang Ning
Published: April 2022

The influence of functional groups on the organic intercalation of montmorillonite (Mt) was discussed in this article by intercalating Mt with four organic compounds containing different cationic functional groups. The maximum intercalation amounts of hexadecyl trimethyl ammonium bromide (CTAB), benzylcetyldimethyl ammonium chloride (HDBAC), bromohexadecyl pyridine (HIB), and 1-hexadecyl-3-methylimidazolium chloride (HMC) were 0.96, 0.81, 0.73, and 0.61 mmol/g, respectively. Molecular simulations revealed that the functional groups influenced the arrangement status of organic cations in the Mt interlayers. It found out that the minimum distances between the nitrogen atom in CTAB, HDBAC, HIB, and HMC and the surface oxygen of Mt were 2.939 ± 0.05, 2.554 ± 0.11, 3.703 ± 0.07, and 3.360 ± 0.08 Å, respectively. Molecular size was also shown to influence intercalation since CTAB was more easily intercalated than the larger HDBAC. Moreover, the benzene ring in HDBAC weakened the interaction between its chains, which decreased its intercalation amount. The –N+ functional groups of HIB and HMC were located on the benzene ring, which weakened their cationic exchange ability. In summary, the functional groups affected the intercalation amount, intercalation rate, and their arrangement (parallel or vertical) in Mt. These results were used to explore the intercalation mechanism of Mt, which can be used to guide the production of novel organic Mt compounds.
Comparison between cold sintering and dry pressing of CaCO3 at room temperature by numerical simulations
Authors: Yasui Kyuichi , Hamamoto Koichi
Published: April 2022

Numerical models of solid-state and liquid-phase sintering of CaCO3 at room temperature are developed for applied static pressures as high as 280 MPa. Under the applied static pressure of 280 MPa, solid-state sintering (dry pressing) also works at room temperature due to the significant increase in the magnitude of the strain rate caused by dislocation processes occurring within the grains. Under the applied static pressure as low as 10 MPa, solid-state sintering no longer works due to the drop in the magnitude of the strain rate caused by dislocation processes occurring within the grains. On the other hand, liquid-phase sintering (cold sintering) still works under 10 MPa at room temperature due to the significant contribution of densification due to rearrangement in the presence of liquid as well as that due to contact flattening by dissolution and precipitation.
Magnetization statics and dynamics in (Ir/Co/Pt)6 multilayers with Dzyaloshinskii–Moriya interaction
Authors: Dhiman A. K. , Gieniusz R. , Gruszecki P. , Kisielewski J. , Matczak M. , Kurant Z. , Sveklo I. , Guzowska U. , Tekielak M. , Stobiecki F. , Maziewski A.
Published: April 2022

Magnetic multilayers of (Ir/Co/Pt)6 with interfacial Dzyaloshinskii-Moriya interaction (IDMI) were deposited by magnetron sputtering with Co thickness d=1.8 nm. Exploiting magneto-optical Kerr effect in longitudinal mode microscopy, magnetic force microscopy, and vibrating sample magnetometry, the magnetic field-driven evolution of domain structures and magnetization hysteresis loops have been studied. The existence of weak stripe domains structure was deduced – tens micrometers size domains with in-plane “core” magnetization modulated by hundred of nanometers domains with out-of-plane magnetization. Micromagnetic simulations interpreted such magnetization distribution. Quantitative evaluation of IDMI was carried out using Brillouin light scattering (BLS) spectroscopy as the difference between Stokes and anti-Stokes peak frequencies Δf. Due to the additive nature of IDMI, the asymmetric combination of Ir and Pt covers led to large values of effective IDMI energy density Deff. It was found that Stokes and anti-Stokes frequencies as well as Δf, measured as a function of in-plane applied magnetic field, show hysteresis. These results are explained under the consideration of the influence of IDMI on the dynamics of the in-plane magnetized “core” with weak stripe domains.
Quantitative evaluation of silicon applications on wheat response to salinity: changes in photosynthetic pigments, chlorophyll fluorescence parameters, yield and yield components
Authors: Feghhenabi Faride , Hadi Hashem , Khodaverdiloo Habib , van Genuchten Martinus Th. , Lake Lachlan
Published: April 2022

Context Salinity is a major cause of yield loss in wheat globally. Aims and Methods To investigate the potential of silicon to minimise the effect of salinity in wheat, experiments were conducted using outdoor pots subjected to seven salinity treatments. Silicon (as potassium silicate K2SiO3) was applied as both a priming agent and foliar spray. Selected response functions were used to quantify wheat response to salinity as affected by silicon application. Key results Concentration of chlorophyll a, chlorophyll b and carotenoid decreased by 4.2, 3.6 and 1.4 mg/g FW respectively with increasing salinity up to an electrical conductivity of 14 dS/m. Increasing salinity levels increased maximum variable chlorophyll fluorescence yield in a dark-adapted state and decreased the photochemical quenching coefficient, the nonphotochemical quenching coefficient, non-photochemical quenching, actual quantum yield of PSII electron transport in the light-adapted state, and the apparent photosynthetic electron transport rate. The maximal efficiency of PSII photochemistry in the dark-adapted state was not significantly influenced by salinity. The response functions showed that the salinity threshold value and the salinity at which a given trait was reduced by 50% (EC50) were 5.7 and 12.1 dS/m, respectively. Conclusions The combined treatment of silicon (priming × foliar spray) was found to be the most effective, increasing salinity threshold value and EC50 by 32 and 2% respectively. Implications These findings give insight into the effects of salinity on wheat and demonstrate the potential of silicon applications to promote crop health in saline environments.
Predicting daily initial attack aircraft targets in British Columbia
Authors: Taylor S. W. , Nadeem K.
Published: April 2022

We developed spatially explicit models of the daily probability of aircraft use in initial attack (IA) on a fire (hereafter the conditional models), and estimates of the unconditional probability of daily aircraft IA targets to support preparedness planning in the province of British Columbia, Canada, using a grid cell × day lasso-logistic framework. Novel aspects of our work include: (1) inclusion of an historical aircraft baseline covariate to account for missing or poorly estimated factors in our models; and of 2 day lead weather and Forest Fire Weather Index (FWI) covariates as proxies for fire potential trend, and (2) linking the conditional models of aircraft use in IA to models of daily fire occurrence to estimate the daily number of aircraft IA targets. The baseline risk of using an aircraft, population and road density were highly influential spatial covariates in both aircraft conditional models. The probability of sustained flaming, temperature, and FWI lead, and Sheltered Duff Moisture Code, temperature, and the Showalter Index were the three most influential meteorological variables in the conditional airtanker and helicopter IA models, respectively. We demonstrate the application of the models to portray the distribution of the expected number of daily aircraft IA targets.
Expression of Hv1 proton channels in myeloid-derived suppressor cells (MDSC) and its potential role in T cell regulation
Authors: Alvear-Arias Juan J. , Carrillo Christian , Villar Javiera Paz , Garcia-Betancourt Richard , Peña-Pichicoi Antonio , Fernandez Audry , Fernandez Miguel , Carmona Emerson M. , Pupo Amaury , Neely Alan , Alvarez Osvaldo , Garate Jose , Barajas-Martinez Héctor , Larsson H. Peter , Lopez-Rodriguez Angélica , Latorre Ramon , Gonzalez Carlos
Published: April 2022

Significance

Immunosuppression by myeloid-derived suppressor cells (MDSC), especially near tumor surfaces, involves the extracellular production of reactive oxygen species (ROS). ROS generation in MDSC occurs during the oxidation of NADPH to NADP+, which NOX2 catalyzes. ROS react with the T cell receptor complex, abolishing the antigen presentation, which blocks the immune system elimination of the tumor cells. Extrusion of protons from MDSC by voltage-gated proton channel (Hv1) sustains ROS production. Here, we demonstrate the expression of Hv1 in mouse MDSC. In this way, Hv1 present in MDSC becomes a potential cancer therapeutic target since its inhibition seems to diminish immunosuppression activity in the tumoral microenvironment, allowing cancer cells to be attacked by the immune system.
Supercurrent diode effect and finite-momentum superconductors
Authors: Yuan Noah F. Q. , Fu Liang
Published: April 2022

Significance

Our work shows a fascinating application of finite-momentum superconductivity, the supercurrent diode effect, which is being reported in a growing number of experiments. We show that, under external magnetic field, Cooper pairs can acquire finite momentum so that critical currents in the direction parallel and antiparallel to the Cooper pair momentum become unequal.
A note on the modeling of the effects of experimental time in psycholinguistic experiments
Authors: Baayen R. Harald , Fasiolo Matteo , Wood Simon , Chuang Yu-Ying
Published: April 2022

Thul et al. (2020) called attention to problems that arise when chronometric
experiments implementing specific factorial designs are analysed with the generalized additive mixed model (GAMM), using factor smooths to
capture trial-to-trial dependencies. From a series of simulations incorporating such dependencies, they conclude that GAMMs are
inappropriate for between-subject designs. They argue that in addition GAMMs come with too many modeling possibilities, and advise using the
linear mixed model (LMM) instead. As clarified by the title of their paper, their conclusion is: “Using GAMMs to model trial-by-trial
fluctuations in experimental data: More risks but hardly any benefit”.

We address the questions raised by Thul et al. (2020), who clearly demonstrated
that problems can indeed arise when using factor smooths in combination with factorial designs. We show that the problem does not arise when
using by-smooths. Furthermore, we have traced a bug in the implementation of factor smooths in the mgcv package, which will
have been removed from version 1.8–36 onwards.

To illustrate that GAMMs now produce correct estimates, we report simulation studies implementing different by-subject
longitudinal effects. The maximal LMM emerges as slightly conservative compared to GAMMs, and GAMMs provide estimated coefficients that can
be less variable across simulation runs. We also discuss two datasets where time-varying effects interact with numerical predictors in a
theoretically informative way.
The action of Con-ikot-ikot toxin on single AMPA-type glutamate receptors
Authors: Baranovic Jelena , Braunbeck Sebastian , Zaki Nikolai , Minniberger Sonja , Chebli Miriam , Plested Andrew J.R.
Published: April 2022

Conotoxins are a large group of naturally occurring toxic peptides produced by the predatory sea snails of the genus Conus. Many of these toxins target ion channels, often with high specificity and affinity. As such, they have proven to be invaluable for basic research, as well as acting as leads for therapeutic strategies. Con-ikot-ikot is the only conotoxin so far identified that targets AMPA-type glutamate receptors, the main mediators of excitatory neurotransmission in the vertebrate brain. Here, we describe how the toxin modifies the activity of AMPA receptors at the single-channel level. The toxin binds to the AMPA receptor with EC50 of 5 nM, and once bound takes minutes to wash out. As shown previously, it effectively blocks desensitization of AMPA receptors; however, compared to other desensitization blockers, it is a poor stabilizer of the open channel because toxin-bound AMPA receptors undergo frequent brief closures. We propose that this is a direct consequence of the toxin’s unique binding mode to the ligand-binding domains (LBDs). Unlike other blockers of desensitization, which stabilize individual dimers within an AMPA receptor tetramer, the toxin immobilizes all four LBDs of the tetramer. This result further emphasizes that quaternary reorganization of independent LBD dimers is essential for the full activity of AMPA receptors.
Large enhancement of thermoelectric effects in multiple quantum dots in a serial configuration due to Coulomb interactions
Authors: Zimbovskaya Natalya A
Published: April 2022

In the present work we theoretically study Seebeck effect in a set of several quantum dots in a serial configuration coupled to nonmagnetic conducting electrodes. We focus on the combined effect of intra-dot Coulomb interactions between electrons and the number of dots on the thermopower (S) and the thermoelectric figure of merit (ZT) of the considered transport junction within the Coulomb blockade regime. We show that a strong enhancement of the both S and ZT may occur when the chemical potential of electrodes is situated within the Coulomb gap in the electron transmission spectrum thus indicating a possibility of significant increase of the efficiency of heat-to-electric energy conversion. The enhancement becomes more pronounced when the number of dots increases.
Spontaneously expanding and shrinking soap bubbles
Authors: Lindén Johan , Fogde Anna
Published: April 2022

An ordinary soap bubble immersed in a pure carbon-dioxide atmosphere, created e.g. by sublimating chunks of dry ice (solid CO2), will expand within a few minutes to a volume exceeding the original one with a factor of almost ten. Considering that the bubble simultaneously experiences a cooling of

∼

30

 
∘

C one would perhaps expect a tiny shrinkage instead. The physics behind the phenomenon, i.e. diffusion of highly soluble CO2 through the soap film caused by the difference in the partial pressure of CO2 between the interior and the exterior of the bubble, combined with the expansion of the active area of the bubble, is discussed. Actual data obtained from a video of an expanding bubble is combined with the simulation of the process, resulting in a fairly good agreement. The reverse experiment of a bubble filled with CO2 under ambient conditions leads to a fast shrinkage of the bubble. Finally, a bubble filled with helium placed in a CO2 atmosphere expands initially, reaches a maximum volume and then begins to shrink. Also this case was modeled semi-empirically. The experiments presented are suitable for upper-secondary-school pupils. Understanding the theoretical description requires first year university studies of physics or chemistry.
To measure the wavelength of the light of a LED using LDR: a simple and an inexpensive method
Authors: Lahane Rohan D , Bhatt Harsh R , Paranjpye Arvind
Published: April 2022

Students are introduced to the term wavelength in optics at school level. In this paper, we present an inexpensive and simple method to measure the wavelength of the light of a light emitting diode using a light depending resistor. This experimental set-up is developed at Science Laboratory, Nehru Planetarium (Mumbai), India. It is useful as an experimental tool to teach the concepts of light in a simpler way.
Comment on ‘An electrostatics paradox’
Authors: Mungan Carl E
Published: April 2022

Cross (2022 Phys. Educ.
57 023001) presents several thought-provoking ideas about the electrical effects of point charges located inside and outside a hollow conductor. Some amplifying remarks are made in this Comment about his discussion.
Reply to Comment on ‘An electrostatics paradox’
Authors: Cross Rod
Published: April 2022

Carl Mungan has amplified my discussion concerning an apparent paradox in electrostatics. I amplify his Comment.
Streamer–surface interaction in an atmospheric pressure dielectric barrier discharge in argon
Authors: Jovanović Aleksandar P , Loffhagen Detlef , Becker Markus M
Published: April 2022

An atmospheric-pressure dielectric barrier discharge (DBD) in argon is investigated using a time-dependent and spatially two-dimensional fluid-Poisson model in axisymmetric geometry. The focus is on the streamer–surface interaction and the cathode-layer formation during the first discharge event in the single-filament DBD driven by sinusoidal voltage. A characteristic structure consisting of a volume streamer propagating just above the dielectric and simultaneous development of an additional surface discharge near the cathode is observed. The analysis of the electric field, electron production and loss rates, and surface charge density distribution shows that the radial deflection of the volume streamer is driven by free electrons remaining in the volume from the Townsend pre-phase and guided by the radial component of the electric field. The surface discharge occurring between the deflected volume streamer, which acts as virtual anode, and the dielectric surface is governed by ion-induced secondary electron emission and the surface charges accumulated on the dielectric.
Finite-density-induced motility and turbulence of chimera solitons
Authors: Smirnov L A , Bolotov M I , Bolotov D I , Osipov G V , Pikovsky A
Published: April 2022

We consider a one-dimensional oscillatory medium with a coupling through a diffusive linear field. In the limit of fast diffusion this setup reduces to the classical Kuramoto–Battogtokh model. We demonstrate that for a finite diffusion stable chimera solitons, namely localized synchronous domain in an infinite asynchronous environment, are possible. The solitons are stable also for finite density of oscillators, but in this case they sway with a nearly constant speed. This finite-density-induced motility disappears in the continuum limit, as the velocity of the solitons is inverse proportional to the density. A long-wave instability of the homogeneous asynchronous state causes soliton turbulence, which appears as a sequence of soliton mergings and creations. As the instability of the asynchronous state becomes stronger, this turbulence develops into a spatio-temporal intermittency.
An efficient technique to analyze the fractional model of vector-borne diseases
Authors: Veeresha P , Malagi Naveen S , Prakasha D G , Baskonus Haci Mehmet
Published: April 2022

In the present work, we find and analyze the approximated analytical solution for the vector-borne diseases model of fractional order with the help of

q

-homotopy analysis transform method (

q

-HATM). Many novel definitions of fractional derivatives have been suggested and utilized in recent years to build mathematical models for a wide range of complex problems with nonlocal effects, memory, or history. The primary goal of this work is to create and assess a Caputo–Fabrizio fractional derivative model for Vector-borne diseases. In this investigation, we looked at a system of six equations that explain how vector-borne diseases evolve in a population and how they affect community public health. With the influence of the fixed-point theorem, we establish the existence and uniqueness of the models system of solutions. Conditions for the presence of the equilibrium point and its local asymptotic stability are derived. We discover novel approximate solutions that swiftly converge. Furthermore, the future technique includes auxiliary parameters that are both trustworthy and practical for managing the convergence of the solution found. The current study reveals that the investigated model is notably dependent on the time chronology and also the time instant, which can be effectively studied with the help of the arbitrary order calculus idea.
Is local H0at odds with dark energy EFT?
Authors: Lee Bum-Hoon , Lee Wonwoo , Ó Colgáin Eoin , Sheikh-Jabbari M.M. , Thakur Somyadip
Published: April 2022

Local H_0 determinations currently fall in a window betweenH0∼ 70 km/s/Mpc (TRGB) andH0∼ 76 km/s/Mpc (Tully-Fisher). In contrast, BAO data calibrated in an early ΛCDM universe are largely consistent with Planck-ΛCDM,H0∼ 67.5 km/s/Mpc. Employing a generic two parameter family of evolving equations of state (EoS) for dark energy (DE)wDE(z) and mock BAO data, we demonstrate that if i)wDE(z= 0) < -1 and ii) integrated DE density less than ΛCDM, thenH0increases. EoS that violate these conditions at best lead to modestH0increases within 1σ. Tellingly, Quintessence and K-essence satisfy neither condition, whereas coupled Quintessence can only satisfy ii). Beyond these seminal DE Effective Field Theories (EFTs), we turn to explicit examples. Working model agnostically in an expansion in powers of redshiftz, we show that Brans-Dicke/f(R) and Kinetic Gravity Braiding models within the Horndeski class can lead to marginal and modest increases inH0, respectively. We confirm that as far as increasingH0is concerned, no DE EFT model can outperform the phenomenological two parameter family of the DE models. Evidently, the late universe may no longer be large enough to accommodateH0, BAO and DE described by EFT.
Application of NASA core Flight System to Telescope Control Software for 2017 Total Solar Eclipse Observation
Authors: Park Jongyeob , Lee Jae-Ok , Kim Jihun , Bong Su-Chan , Cho Kyung-Suk , Choi Seonghwan , Jang Bi-Ho , Park Young-Deuk , Moon Yong-Jae , Baek Ji-Hye , Yang Heesu , Kim Sujin , Kim Yeon-Han , Timmons Elizabeth , Swinski Joseph-paul A.
Published: April 2022

The core Flight System (cFS), developed by NASA, is a reusable software framework and a set of pluggable software applications that take advantage of the rich heritage of NASA’s successful space missions. We applied the cFS to the development of telescope control software for the observation of the 2017 total solar eclipse. Four main modules were developed: imaging control, mechanism control, data handling, and automated observation. Other modules, such as communication and scheduler, were reused from the cFS. Using an integrated observation system, we successfully observed the total solar eclipse, in which the linearly polarized brightness of the solar corona and sky background were measured at four different wavelengths. In this study, we demonstrated the usefulness of the cFS to develop telescope control software through an eclipse observation system, the so-called DICE (DIagnostic Coronagraph Experiment) mission. Our experience and knowledge of the cFS were expanded to a flight software BITSE (Balloon-borne Investigation of Temperature and Speed of Electrons in the corona), the high-altitude scientific balloon mission in 2019. We plan to apply this approach to future solar coronagraph observations, such as CODEX (COronal Diagnostic EXperiment), on the International Space Station. We expect that the cFS can also be applied in telescope control software for ground-and space-based observations.
TAP: targeting and analysis pipeline for optimization and verification of coil placement in transcranial magnetic stimulation
Authors: Dannhauer Moritz , Huang Ziping , Beynel Lysianne , Wood Eleanor , Bukhari-Parlakturk Noreen , Peterchev Angel V
Published: April 2022

Objective. Transcranial magnetic stimulation (TMS) can modulate brain function via an electric field (E-field) induced in a brain region of interest (ROI). The ROI E-field can be computationally maximized and set to match a specific reference using individualized head models to find the optimal coil placement and stimulus intensity. However, the available software lacks many practical features for prospective planning of TMS interventions and retrospective evaluation of the experimental targeting accuracy. Approach. The TMS targeting and analysis pipeline (TAP) software uses an MRI/fMRI-derived brain target to optimize coil placement considering experimental parameters such as the subject’s hair thickness and coil placement restrictions. The coil placement optimization is implemented in SimNIBS 3.2, for which an additional graphical user interface (TargetingNavigator) is provided to visualize/adjust procedural parameters. The coil optimization process also computes the E-field at the target, allowing the selection of the TMS device intensity setting to achieve specific E-field strengths. The optimized coil placement information is prepared for neuronavigation software, which supports targeting during the TMS procedure. The neuronavigation system can record the coil placement during the experiment, and these data can be processed in TAP to quantify the accuracy of the experimental TMS coil placement and induced E-field. Main results. TAP was demonstrated in a study consisting of three repetitive TMS sessions in five subjects. TMS was delivered by an experienced operator under neuronavigation with the computationally optimized coil placement. Analysis of the experimental accuracy from the recorded neuronavigation data indicated coil location and orientation deviations up to about 2 mm and 2°, respectively, resulting in an 8% median decrease in the target E-field magnitude compared to the optimal placement. Significance. TAP supports navigated TMS with a variety of features for rigorous and reproducible stimulation delivery, including planning and evaluation of coil placement and intensity selection for E-field-based dosing.
Semi-supervised EEG emotion recognition model based on enhanced graph fusion and GCN
Authors: Li Guangqiang , Chen Ning , Jin Jing
Published: April 2022

Objective. To take full advantage of both labeled data and unlabeled ones, the Graph Convolutional Network (GCN) was introduced in electroencephalography (EEG) based emotion recognition to achieve feature propagation. However, a single feature cannot represent the emotional state entirely and precisely due to the instability of the EEG signal and the complexity of the emotional state. In addition, the noise existing in the graph may affect the performance greatly. To solve these problems, it was necessary to introduce feature/similarity fusion and noise reduction strategies. Approach. A semi-supervised EEG emotion recognition model combining graph fusion, network enhancement, and feature fusion was proposed. Firstly, different features were extracted from EEG and then compacted by Principal Component Analysis (PCA), respectively. Secondly, a Sample-by-sample Similarity Matrix (SSM) was constructed based on each feature, and similarity network fusion (SNF) was adopted to fuse the graphs corresponding to different SSMs to take advantage of their complementarity. Then, Network Enhancement (NE) was performed on the fused graph to reduce the noise in it. Finally, GCN was performed on the concatenated features and the enhanced fused graph to achieve feature propagation. Main results. Experimental results demonstrated that: (a) When 5.30

%

of SEED and 7.20

%

of SEED-IV samples were chosen as the labeled samples, respectively, the minimum classification accuracy improvement achieved by the proposed scheme over state-of-the-art schemes were 1.52

%

on SEED and 13.14

%

on SEED-IV, respectively. (b) When 8.00

%

of SEED and 9.60

%

of SEED-IV samples were chosen as the labeled samples, respectively, the minimum training time reduction achieved by the proposed scheme over state-of-the-art schemes were 46.75 s and 22.55 s, respectively. (c) Graph fusion, network enhancement, and feature fusion all contributed to the performance enhancement. (d) The key hyperparameters that affect the performance were relatively few and easy to set to obtain outstanding performance. Significance. This paper demonstrated that the combination of graph fusion, network enhancement, and feature fusion help to enhance GCN-based EEG emotion recognition.
Nonlinear response of human trunk musculature explains neuromuscular stabilization mechanisms in sitting posture
Authors: Noamani Alireza , Vette Albert H , Rouhani Hossein
Published: April 2022

Objective. Determining the roles of underlying mechanisms involved in stabilizing the human trunk during sitting is a fundamental challenge in human motor control. However, distinguishing their roles requires understanding their complex interrelations and describing them with physiologically meaningful neuromechanical parameters. The literature has shown that such mechanistic understanding contributes to diagnosing and improving impaired balance as well as developing assistive technologies for restoring trunk stability. This study aimed to provide a comprehensive characterization of the underlying neuromuscular stabilization mechanisms involved in human sitting. Approach. This study characterized passive and active stabilization mechanisms involved in seated stability by identifying a nonlinear neuromechanical physiologically-meaningful model in ten able-bodied individuals during perturbed sitting via an adaptive unscented Kalman filter to account for the nonlinear time-varying process and measurement noises. Main results. We observed that the passive mechanism provided instant resistance against gravitational disturbances, whereas the active mechanism provided delayed complementary phasic response against external disturbances by activating appropriate trunk muscles while showing non-isometric behavior. The model predicted the trunk sway behavior during perturbed sitting with high accuracy and correlation (average: 0.0007 (rad2) and 86.77%). This allows a better mechanistic understanding of the roles of passive and active stabilization mechanisms involved in sitting. Significance. Our characterization approach accounts for the inherently nonlinear behavior of the neuromuscular mechanisms and physiological uncertainties, while allowing for real-time tracking and correction of parameters’ variations due to external disturbances and muscle fatigue. The outcome of our research, for the first time, (a) allows a better mechanistic understanding of the roles of passive and active stabilization mechanisms involved in sitting; (b) enables objective evaluation and targeted rehabilitative interventions for impaired balance; facilitate bio-inspired designs of assistive technologies, and (c) opens new horizons in mathematical identification of neuromechanical mechanisms employed in the stable control of human body postures and motions.
Graphene oxide reinforced epoxy nanocomposites coatings for corrosion protection: a review
Authors: Harsha Voleti Sri Sai , Sharma Ambuj , Tambe Pankaj
Published: April 2022

Graphene oxide (GO) is a reinforcing filler material used in epoxy resin to make coatings for improving the corrosion resistance of epoxy. The synthesis methods of GO are discussed with their modification methods (covalently and non-covalently). The incorporation of GO in epoxy resin nanocomposites coatings shows the improved corrosion resistance and adhesion strength depends on the processing protocol and aspect ratio of GO. Modification of GO covalently and non-covalently and reinforced in epoxy nanocomposites coatings show the enhanced corrosion protection as compared to pure epoxy and epoxy/GO nanocomposites coatings due to improved dispersion of GO in an epoxy matrix. Inorganic nanofiller modified with GO as hybrid reinforcement in epoxy nanocomposites coatings shows improved corrosion resistance as compared to epoxy/GO nanocomposites. GO/inorganic hybrid filler reinforced in epoxy nanocomposites coatings are promising in terms of applications in the industry for long time corrosion protection.