bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of precession versus instabilities on the jets of GRS 1758–258
Authors: Luque-Escamilla Pedro L. , Martí Josep , Martínez-Aroza José
Published: October 2020

Aims. The prototypical microquasar GRS 1758–258 exhibits large-scale morphological changes in radio maps over time which have been attributed to the rise of instabilities. Here, we investigate whether these effects could be attributed to jet precession instead.

Methods. We used new and archival radio maps to fit a kinematic jet precession model. The value of the parameters thus obtained were analysed in order to get constraints on the physical properties of the GRS 1758–258 system. Their consistency with different theories of the origins for the jet precession, such as Lense–Thirring effect and tidal torques induced by the secondary star, has previously been studied. Alternatively, we also assessed the possibility that observations are compatible with eventual jet instabilities.

Results. The new radio data presented here confirm that the large-scale radio morphology of GRS 1758–258 is changing over time. Our study shows that the 18.48 day period could plausibly be ascribed to precession, thus implying a reinterpretation of assumptions made for the orbital period to date. However, the observed structural changes in radio jets cannot be easily attributed to jet precession according to our analysis. In contrast, the growth of instabilities certainly appears to be a more realistic explanation of these effects.
Three open clusters containing Cepheids: NGC 6649, NGC 6664, and Berkeley 55
Authors: Alonso-Santiago J. , Negueruela I. , Marco A. , Tabernero H. M. , Castro N.
Published: October 2020

Classical Cepheids in open clusters play an important role in benchmarking stellar evolution models, in addition to anchoring the cosmic distance scale and invariably securing the Hubble constant. Three pertinent clusters hosting classical Cepheids and red (super)giants are: NGC 6649, NGC 6664, and Berkeley 55. These clusters form the basis of analysis to assess newly acquired spectra (≈50), archival photometry, andGaiaDR2 data. Importantly, for the first time chemical abundances were determined for the evolved members of NGC 6649 and NGC 6664. We find that they are slightly metal-poor relative to the mean Galactic gradient. Also, an overabundance of Ba is observed. These two clusters likely belong to the thin disc and the latter finding supports the “s-enhanced” scenario of D’Orazi et al. (2009). NGC 6664 and Berkeley 55 exhibit radial velocities consistent with Galactic rotation, while NGC 6649 displays a peculiar velocity. The resulting age estimates for the clusters (≈70 Ma) imply masses of ≈6M⊙for the (super)giant demographic. Lastly, the observed yellow-to-red (super)giant ratio is lower than expected and the overall differences that are relative to the models reflect the outstanding theoretical uncertainties.
The volumetric star formation law for nearby galaxies
Authors: Bacchini Cecilia , Fraternali Filippo , Pezzulli Gabriele , Marasco Antonino
Published: October 2020

In the last decades, much effort has been put into finding the star formation law, which could unequivocally link the gas and the star formation rate (SFR) densities measured on a sub-kiloparsec scale in star-forming galaxies. The conventional approach of using the observed surface densities to infer star formation laws has however revealed a major and well-known issue, as such relations are valid for the high-density regions of galaxies but break down in low-density and HI-dominated environments. Recently, an empirical correlation between the total gas (HI+H2) and the SFR volume densities was obtained for a sample of nearby disc galaxies and for the Milky Way. This volumetric star formation (VSF) law is a single power-law with no break and a smaller intrinsic scatter with respect to the star formation laws based on the surface density. In this work, we explore the VSF law in the regime of dwarf galaxies in order to test its validity in HI-dominated, low-density, and low-metallicity environments. In addition, we assess this relation in the outskirts of spiral galaxies, which are low-density and HI-dominated regions similar to dwarf galaxies. Remarkably, we find that the VSF law, namelyρSFR∝ρgasαwithα ≈ 2, is valid for both these regimes. This result indicates that the VSF law, which holds unbroken for a wide range of gas (≈3 dex) and SFR (≈6 dex) volume densities, is the empirical relation with the smallest intrinsic scatter and is likely more fundamental than surface-based star formation laws.
Mass and metallicity distribution of parent AGB stars of presolar SiC
Authors: Cristallo S. , Nanni A. , Cescutti G. , Minchev I. , Liu N. , Vescovi D. , Gobrecht D. , Piersanti L.
Published: October 2020

The vast majority (≳90%) of presolar SiC grains identified in primitive meteorites are relics of ancient asymptotic giant branch (AGB) stars, whose ejecta were incorporated into the Solar System during its formation. Detailed characterization of these ancient stardust grains has revealed valuable information on mixing processes in AGB interiors in great detail. However, the mass and metallicity distribution of their parent stars still remains ambiguous, although such information is crucial to investigating the slow neutron-capture process, whose efficiency depends on mass and metallicity. Using a well-known Milky Way chemo-dynamical model, we followed the evolution of the AGB stars that polluted the Solar System at 4.57 Gyr ago and weighted the stars based on their SiC dust productions. We find that presolar SiC in the Solar System predominantly originated from AGB stars with M ∼ 2 M⊙ and Z ∼ Z⊙. Our finding well explains the grain-size distribution of presolar SiC identified in situ in primitive meteorites. Moreover, it provides complementary results to very recent papers that characterized parent stars of presolar SiC.
Measures for controlling the material flow when extruding sheet-bulk metal forming parts from coil
Authors: Henneberg Johannes , Merklein Marion
Published: October 2020

The increasing demand for lightweight design requires functional integration. This poses challenges to conventional manufacturing processes due to the rising geometrical complexity of components. The application of bulk forming operations to sheet metal, named sheet-bulk metal forming (SBMF), is one approach to overcome these challenges. Currently, mainly pre-cut blanks are applied in research of SBMF. Production from coil, in contrast, would combine the advantages of SBMF with the advantages of manufacturing from a coil regarding high output quantity. To research SBMF from coil, a lateral and a backward extrusion process are set up. In addition to a reduced geometrical accuracy of the parts, which is known from SBMF of pre-cut blanks, an anisotropic material flow is identified as a coil-specific challenge. The aim of this research is to investigate measures that extend the forming limits by means of a material flow control. For this purpose, a combined numerical-experimental approach is applied in order to analyze and evaluate an adaption of the width of the coil, the feed width, and the local friction as measures for material flow control. Particularly local adaptation of friction by means of modified tool surfaces reduces the anisotropic material flow and improves the geometrical accuracy of the parts.
Das Bad Neuenahr-Ahrweilerer Modell für gesunde, lebenswerte Arbeitswelten: Kooperationen von ergebnis- und erlebnisorientierten Gesundheitsbereichen
Authors: Poersch Marius
Published: October 2020

Alle gesundheitsförderlichen betrieblichen Bemühungen beginnen in den Köpfen der Akteure mit dem von Ihnen (un)bewusst bevorzugtem Gesundheitsmodell und den daraus abgeleiteten Vorstellungen über Gesundheit und ihren Fördermöglichkeiten. Der Autor hat sich mit vielfältigen Gesprächspartnern (Rehabilitanden, Patienten, Coachees, Ärzten, Psychologen, Berater, Führungskräfte und Gesundheitsmanager) über Jahre auf die Suche nach einem neuen, zeitgemäßen betrieblichen Gesundheitsmodell begeben. Seit April 2018 hat er in monatlichen Konferenzen im regionalen BGM-Netzwerk der Stadt Bad Neuenahr-Ahrweiler hierzu mit vielfältigen Teilnehmern intensiv diskutiert und stellt nun das „Bad Neuenahr-Ahrweilerer Modell für gesunde, lebenswerte Arbeitswelten“ vor.
Ergebnisse der COVID-19-Umfrage der Deutschen Gesellschaft für
Rehabilitationswissenschaften e.V. (DGRW)
Authors: Meyer Thorsten , Posthumus Elain ,   für den Vorstand der DGRW
Published: October 2020

Hintergrund und Ziel

COVID-19 stellt eine substanzielle Bedrohung der Gesundheit und in der Folge auch der
Lebensbedingungen der Menschen weltweit dar. Die Erkrankung entsteht infolge einer
Infektion mit dem neuartigen Coronavirus SARS-CoV-2. Erkenntnisse über
molekulare Grundlagen, Pathophysiologie, klinische Charakteristika, Epidemiologie,
aber auch Ressourcenbedarf und Outcomes (z. B. Karagiannidis et al. 2020; zur Übersicht s. Website der WHO:
https://search.bvsalud.org/global-literature-on-novel-coronavirus-2019-ncov/)
wachsen in beispiellos kurzem Zeitraum weltweit an, auch im Feld der Rehabilitation
(vgl. Negrini et al. 2020). Die Erkenntnisse
münden in Leitlinien, Policy Briefs oder konkreten Handlungsempfehlungen
(vgl. Publikationen des Kompetenznetz Public Health COVID-19,
www.public-health-covid19.de).
Synchronisation des Liegeverhaltens von Mastbullen bei verschiedenen Platzangeboten
Authors: Schneider Laura , Volkmann Nina , Spindler Birgit , Kemper Nicole
Published: October 2020

Gegenstand und Ziel Die Synchronisation des Liegens ist ein wichtiger Teil des natürlichen Rinderverhaltens. Die niedersächsische Tierschutzleitlinie für die Mastbullenhaltung fordert erstmals eine Liegefläche, deren Größe ein zeitgleiches Liegen aller Tiere ermöglicht. Allerdings wurde die Synchronisation des Liegens bei Mastbullen bisher kaum wissenschaftlich untersucht und es fehlen auch genaue Angaben zur Fläche, die Mastbullen zum Liegen benötigen. Ziel der Studie war daher zu untersuchen, inwiefern Mastbullen bei verschiedenen Platzangeboten synchron liegen und ob ein zeitgleiches Liegen aller Tiere pro Bucht stattfindet.

Material und Methoden Analysiert wurde das Liegeverhalten von 41 Mastbullen mit einem Körpergewicht > 450 kg in teil- und vollgummierten Vollspaltenbuchten. Die Haltung der Bullen erfolgte in Gruppen von 6–8 Tieren in 3 Platzangebotsgruppen (A: 3,1–3,5 m2; B: 4,0–4,2 m2, C: 6,7 m2 pro Tier). Pro Gruppe wurden in je zwei Buchten die Liegezeiten aller Einzeltiere mittels Videoaufnahmen über 2 aufeinanderfolgende Hellphasen (insgesamt 17 Stunden) erfasst.

Ergebnisse Während der beiden Hellphasen lagen die Mastbullen der verschiedenen Gruppen durchschnittlich 5 h 30 min bis 9 h 6 min. In je einer Bucht der Platzangebotsgruppen A und B trat zeitgleiches Liegen aller Tiere im Beobachtungszeitraum gar nicht auf und in den übrigen Buchten über 27 min bis 4 h. Mindestens 80 % der Tiere lagen in allen Buchten während 1 h 30 min bis 7 h 13 min.

Schlussfolgerungen und klinische Relevanz Bei praxisüblichem Platzangebot zwischen 3,1 m2 und 4,2 m2 war im Beobachtungszeitraum in einzelnen Buchten kein zeitgleiches Liegen aller Tiere feststellbar. Phasen, in denen nur einzelne Tiere standen oder ein Tier aufstand und sich sofort darauf ein anderes Tier hinlegte, deuten darauf hin, dass die Tiere zu einer Synchronisation des Liegeverhaltens neigten, die Platzangebote von 3,1 m2 und 4,2 m2 aber kein zeitgleiches Liegen aller Tiere erlaubten. Die Ergebnisse betonen die Notwendigkeit weiterer Studien zum Liegeflächenbedarf von Mastbullen, um das Platzangebot zu definieren, das für das zeitgleiche Liegen aller Tiere benötigt wird.
Verhaltensassoziierte und physiologische Indikatoren für Schmerz und Unwohlsein bei Kälbern nach Schwanzamputation
Authors: Mayer Carina , Zablotski Yury , Rieger Anna , Knubben-Schweizer Gabriela , Feist Melanie
Published: October 2020

Gegenstand und Ziel Die prophylaktische Amputation der bindegewebigen Schwanzspitze mittels Gummiring ist in Deutschland nach TSchG § 6 Abs. 3 Nr. 3 bei Mastbullenkälbern genehmigungspflichtig und erfolgt zur Vermeidung von Schwanzspitzennekrosen. Andere haltungstechnische Eingriffe bei Kälbern, wie Enthornung und Kastration, sind mit Stress und Schmerzen für das Tier verbunden. Auch eine weiter proximal, im Zwischenwirbelspalt durchgeführte Amputation des Schwanzes hat erkennbare Auswirkungen auf das Tier. Dagegen gibt es zur Amputation der bindegewebigen Schwanzspitze bisher keine Studie, die entstehende Belastungen für das Kalb untersucht. Ziel der vorliegenden Pilotstudie war, das Schmerzerlebnis der Kälber bei diesem Eingriff zu erfassen.

Material und Methoden Im Rahmen einer Doppelblindstudie wurden 16 männliche, 8–10 Wochen alte Fleckvieh- oder Fleckviehkreuzungskälber untersucht. Probanden der Gruppe A (Amputation) wurde an Tag 0 ein Gummiring 3 cm oberhalb der Schwanzspitze angelegt, bei Tieren der Gruppe K (Kontrolle) erfolgte an dieser Stelle ein Kontrollhandling. Nach dem Eingriff wurde mittels ELISA die Konzentration von Kortisol und Substanz P im Blutplasma untersucht sowie Verhaltens- und Aktivitätsparameter anhand videogestützter Verhaltensbeobachtung und Pedometerdaten erfasst.

Ergebnisse Der Eingriff beeinflusste die Substanz-P-Konzentration nicht. Anders als in Gruppe A sank in Gruppe K die Kortisolkonzentration im Vergleich zum Basalwert ab. An Tag 0 zeigten Kälber der Gruppe A im Vergleich zu Tieren der Gruppe K eine höhere Schrittzahl, vermehrtes Schlagen mit dem Schwanz sowie häufigere Interaktionen des Kopfes mit Schwanz oder Hinterhand.

Schlussfolgerung Eine höhere Schrittzahl nach Anbringen des Gummirings lässt sich als Zeichen für Unruhe interpretieren, gehäuftes Schwanzschlagen und Benagen/Belecken des Schwanzes als schmerzbedingtes Abwehrverhalten. In Kombination mit dem gleichbleibend hohen Kortisolspiegel sprechen diese Parameter für eine schmerzhafte Belastung der Kälber durch die Amputation.

Klinische Relevanz Um die Inzidenz von Schwanzspitzennekrosen zu vermindern, sollte zunächst eine tierschutzgerechte Verbesserung der Haltungsumwelt im Vordergrund stehen. Bei Durchführung der Amputation lässt sich auf Grundlage dieser Studie die Gabe eines nicht steroidalen Antiphlogistikums vor Anlegen des Gummirings empfehlen, um die Schmerzbelastung für das Tier zu minimieren.
An Efficient and Concise Synthesis of α-Galactosylceramide
Authors: Imperio Daniela , Morelli Laura , Compostella Federica , Panza Luigi
Published: October 2020

A concise and stereoselective synthesis of α-galactosylceramide (α-GalCer) is described. The key features of the synthetic strategy are the use of a phytosphingosine in which the amine is masked as a tetrachlorophthalimide and the diol as an isopropylidene acetal, and the galactosyl donor is protected as a 4,6-benzylidene to improve the α selectivity of the glycosylation reaction. The pattern of protecting groups on the donor and the acceptor have proven to give an excellent match of reactivity, allowing the glycosylation reaction to take place stereoselectively. The overall synthesis gave α-GalCer in good yields and in few steps.
Cost-effectiveness analysis of SARS-CoV-2 infection prevention strategies including pre-endoscopic virus testing and use of high risk personal protective equipment
Authors: Ebigbo Alanna , Römmele Christoph , Bartenschlager Christina , Temizel Selin , Kling Elisabeth , Brunner Jens , Messmann Helmut
Published: October 2020

Background Infection prevention strategies to protect healthcare workers in endoscopy units during the post-peak phase of the COVID-19 pandemic are currently under intense discussion. In this paper, the cost-effectiveness of routine pre-endoscopy testing and high risk personal protective equipment (PPE) is addressed.

Method A model based on theoretical assumptions of 10 000 asymptomatic patients presenting to a high volume center was created. Incremental cost-effectiveness ratios (ICERs) and absolute costs per endoscopy were calculated using a Monte Carlo simulation.

Results ICER values for universal testing decreased with increasing prevalence rates. For higher prevalence rates (≥ 1 %), ICER values were lowest for routine pre-endoscopy testing coupled with use of high risk PPE, while cost per endoscopy was lowest for routine use of high risk PPE without universal testing.

Conclusion In general, routine pre-endoscopy testing combined with high risk PPE becomes more cost-effective with rising prevalence rates of COVID-19.
Impacto femoroacetabular e lesão do lábio acetabular – Parte 3: Tratamento cirúrgico
Authors: Queiroz Marcelo C. , Ricioli Junior Walter , Ejnisman Leandro , Gurgel Henrique Melo de Campos , Miyahara Helder de Souza , Polesello Giancarlo Cavalli
Published: October 2020

Nos últimos 15 anos, o diagnóstico do impacto femoroacetabular tem se tornado cada vez mais frequente; com o avanço do entendimento de quais pacientes potencialmente se beneficiariam do tratamento cirúrgico, diferentes técnicas foram desenvolvidas. O tratamento cirúrgico inclui grande variedade de opções, sendo elas: osteotomia periacetabular, técnica de luxação cirúrgica do quadril, artroscopia com osteocondroplastia via pequena incisão, técnica via anterior modificada, e técnica exclusivamente artroscópica. O tipo de abordagem deve ser escolhido de acordo com a complexidade da morfologia do impacto femoroacetabular e com o treinamento do cirurgião. As técnicas mais utilizadas atualmente são a artroscopia, a luxação cirúrgica do quadril e a osteotomia periacetabular. O presente artigo busca descrever as principais técnicas cirúrgicas utilizadas para o tratamento do impacto femoroacetabular, suas indicações, vantagens e desvantagens, complicações e resultados clínicos.
Perfectly absorbing dielectric metasurfaces for photodetection
Authors: Mitrofanov Oleg , Hale Lucy L. , Vabishchevich Polina P. , Luk Ting Shan , Addamane Sadhvikas J. , Reno John L. , Brener Igal
Published: October 2020

Perfect absorption of light by an optically thin metasurface is among several remarkable optical functionalities enabled by nanophotonics. This functionality can be introduced into optoelectronic devices by structuring an active semiconductor-based element as a perfectly absorbing all-dielectric metasurface, leading to improved optical properties while simultaneously providing electrical conductivity. However, a delicate combination of geometrical and material parameters is required for perfect absorption, and currently, no general all-dielectric metasurface design fulfills these conditions for a desired semiconductor and operation wavelength. Here, using numerical simulations, we demonstrate that Mie resonators with subwavelength-size interconnecting channels allow this combination of perfect absorption requirements to be satisfied for different wavelengths of operation and different levels of intrinsic material absorption. We reveal the underlying physics and show that interconnecting channels play a critical role in achieving perfect absorption through their effects on the resonant wavelengths and losses for the electric dipole and magnetic dipole modes in Mie resonators. By adjusting only the channel widths, perfect absorption can be achieved for an optically thin GaAs-based metasurface at a desired wavelength of operation in a range from 715 nm to 840 nm, where the intrinsic absorption level in GaAs varies by more than a factor of 2. Optical transmission experiments confirm that these metasurfaces resonantly enhance optical absorption. This work lays out the foundation and guidelines for replacing bulk semiconductors with electrically connected, optically thin, perfectly absorbing metasurfaces in optical detectors.
Soft peripheral nerve interface made from carbon nanotubes embedded in silicone
Authors: Terkan Korkut , Zurita Francisco , Jamal Khalaf Touba , Rinklin Philipp , Teshima Tetsuhiko , Kohl Tobias , Wolfrum Bernhard
Published: October 2020

Electrodes for interfacing implantable electronics and neural tissue are of great importance to gain a better understanding of the nervous system and to help people suffering from impaired body functions due to nerve lesions or lost organ functionality. In particular, neurostimulation techniques for bioelectronic medicine rely on the development of mechanically and electrochemically stable electrodes. While contemporary electrodes are based mainly on metals, new materials are being designed to enhance the mechanical and electrochemical properties of the interface. In this work, a nerve interface based on carbon nanotubes (CNTs) embedded in polydimethylsiloxane (PDMS) is fabricated and investigated. The fabrication process relies on the selective vacuum filtration of CNT suspensions through a printed wax pattern. The mechanical and electrochemical stability of the nerve interface was validated by 10 000 stretching cycles up to 20% strain and >4 × 106 biphasic stimulation pulses with 32 μC cm−2 per phase. The feedline resistance and electrode impedance showed only minor alterations after the stress tests. The functionality of the nerve interface was demonstrated by successful stimulation of the central nerve cord of a horse leech applying stimulation conditions within the water window of the CNT/PDMS electrodes. This work shows the practical usability of CNT/PDMS composites as electrodes and feedlines in peripheral nerve interfaces for future neuroprosthetic devices.
Generation of coherent phonons via a cavity enhanced photonic lambda scheme
Authors: Bourhill J. , Carvalho N. C. , Goryachev M. , Galliou Serge , Tobar M. E.
Published: October 2020

We demonstrate the generation of coherent phonons in a quartz bulk acoustic wave (BAW) resonator through the photoelastic properties of the crystal, via coupling to a microwave cavity enhanced by a photonic lambda scheme. This is achieved by imbedding a single crystal BAW resonator between the post and the adjacent wall of a microwave re-entrant cavity resonator. This 3D photonic lumped LC resonator at the same time acts as the electrode of a BAW phonon resonator and allows the direct readout of coherent phonons via the linear piezoelectric response of the quartz. A microwave pump, ωp, is tuned to the cavity resonance ω0, while a probe frequency, ωprobe, is detuned and varied around the red and blue detuned values with respect to the BAW phonon frequency, Ωm. The pump and probe power dependence of the generated phonons unequivocally determines the process to be electrostrictive, with the phonons produced at the difference frequency between the pump and the probe, with no back action effects involved. Thus, the phonons are created without threshold and can be considered analogous to a passive coherent population trapped maser scheme.
Thermally assisted charge transfer and charge separation in organic donor–acceptor solar cells
Authors: Gao Teng , Lu Qiuxia , Qin Wei , Qu Fanyao , Xie Shijie
Published: October 2020

We propose a mechanism based on thermally assisted charge transfer (CT) to study the thermal effect on the formation of CT states and subsequent charge separation in an organic donor–acceptor solar cell. We reveal that the difference between phonons in the donor and acceptor caused by elastic energy acts as a thermally assisted driving force for charge transfer. It is found that the system exhibits a quite different CT process in the high and low temperature regions. Remarkably, combined with the entropy driving mechanics, the thermally assisted CT yields charge separation probability as high as 70% at room temperature. Our model and results provide a microscopic quantum understanding of the relevant recent experiments and open up a route to realize high-efficiency organic solar cells by effectively taking advantage of the thermal effect.
Dynamics of a dielectric microsphere inside a nonlinear laser trap
Authors: Devi Anita , Yadav Sumit , De Arijit K.
Published: October 2020

The 2018 Nobel Prize in Physics was awarded for the invention of optical trapping and generation of ultrashort pulses, which revolutionized many areas of modern science and technology. However, physics of optical trapping under ultra-short pulsed excitation has not been explored much. The nonlinear nature of optical trapping force/potential under ultra-short pulsed excitation was theoretically investigated, however, without any direct experimental demonstration and development of any generalized theory independent of the particle size. In this work, we present a methodology to numerically estimate trapping force/potential including optical as well as thermal nonlinearity under ultra-short pulsed excitation and implement a variety of detection modalities to capture the particle's real-time trajectories. We show how highly asymmetric nonlinear axial potential, created by a femtosecond pulse-train, can be mapped from the dynamics of the trapped particle. Considering fine-tuning of trap-stiffness by changing nonlinearity, we envision far-reaching applications of using ultra-short pulsed excitation in laser trapping and manipulation.
Opto-fluidic-plasmonic liquid-metal core microcavity
Authors: Lu Qijing , Chen Xiaogang , Liu Xianlin , Guo Junqiang , Xie Shusen , Wu Xiang , Zou Chang-Ling , Dong Chun-Hua
Published: October 2020

A hybrid microcavity based on the liquid-metal-filled silica microbubble is experimentally demonstrated, which supports both plasmonic and optical whispering gallery modes. The high quality (Q)-factor plasmonic mode of liquid metal is demonstrated via controlling the polarization of the probe laser as well as changing the liquids in the microbubble. Additionally, we reveal an unconventional Q-factor enhancement effect in the bottle microresonator. The liquid metal (mercury) could dissolve various metals and solids, meriting the optofluidic type of sensing. Combining the two kinds of high-Q resonances in the hybrid microcavity, we could probe the optical, mechanical, and thermal properties of solvents in liquid metal, providing a unique experimental platform for realizing multi-parameter optical sensing and making the detection and identification of metal and alloy possible.
Reduction of background scattered light in vacuum systems for cold atoms experiments
Authors: Vovrosh J. , Earl L. , Thomas H. , Winch J. , Stray B. , Ridley K. , Langlois M. , Bongs K. , Holynski M.
Published: October 2020

Recent advances in the understanding and control of cold atom systems have resulted in devices with extraordinary metrological performance. To further improve the performance in these systems, additional methods of noise reduction are needed. Here, we examine the noise reduction possible from vacuum compatible low reflection coatings in cold atom systems by characterizing a black coating and its compatibility in a Magneto-Optical Trap (MOT). We demonstrate that the commercially available PCO35® coating provides low-reflectivity surfaces that are ultra-high vacuum compatible. The reflective properties of the coating are compared to titanium, a common vacuum chamber material, and the reduction to scattered light is characterized over a range of angles and wavelengths. The outgassing properties of the coating are measured to be less than that of the vacuum system used to test the coating, which is limited to 3 × 10−8 mbar L cm−2 s−1. The coating is applied to a vacuum chamber housing a rubidium prism MOT, and its vacuum compatibility is assessed and compared to an identical non-coated system. Finally, the effect of scattered light reduction in a generalized system is explored theoretically. These results show promise for reducing background light in cold atom experiments via the use of low-reflectivity coatings.
Diversity and volume of international trade in Old World pitcher plants
Authors: Šetlíková Irena , Berec Michal
Published: October 2020

In global trade analyses, plants are neglected in comparison to animals. Controlling and monitoring international trade in threatened species contributes to their overall conservation. Here, an in-depth look at the dynamics of the international trade in attractive and widely traded carnivorous Old World pitcher plants (Nepenthes spp.) from their first appearance in the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) Trade Database in 1983 until 2017 is presented. The current trade of Nepenthes is rapidly growing in terms of the total volume traded and the number of both species and importing countries. Most of pitcher plants are globally traded as artificially propagated live plants. The share of wild-originated live plants was only 0.09%. Hybrids and Nepenthes spp. dominated the trade, representing 61 and 15% of the total traded volume respectively, followed by N. alata and N. mirabilis. The latter species was also the most traded species from the wild. Sri Lanka is a hotspot, exporting the highest volume and number of species of live pitcher plants. Monitoring of the trade is complicated by (1) the absence of a permit obligation for seeds, seedlings and in vitro cultures, and (2) the outdated list of valid species in the CITES Checklist. Using a holistic approach with a focus on the permanent monitoring, recording and assessing of international trade is desirable.
Epidemic poliomyelitis, post-poliomyelitis sequelae and the eradication program
Authors: Peel Margaret M
Published: October 2020

Epidemics of paralytic poliomyelitis (polio) first emerged in the late 19th and early 20th centuries in the United States and the Scandinavian countries. They continued through the first half of the 20th century becoming global. A major epidemic occurred in Australia in 1951 but significant outbreaks were reported from the late 1930s to 1954. The poliovirus is an enterovirus that is usually transmitted by the faecal–oral route but only one in about 150 infections results in paralysis when the central nervous system is invaded. The Salk inactivated polio vaccine (IPV) became available in Australia in 1956 and the Sabin live attenuated oral polio vaccine (OPV) was introduced in 1966. After decades of stability, many survivors of the earlier epidemics experience late-onset sequelae including post-polio syndrome. The World Health Organization launched the global polio eradication initiative (GPEI) in 1988 based on the easily administered OPV. The GPEI has resulted in a dramatic decrease in cases of wild polio so that only Pakistan and Afghanistan report such cases in 2020. However, a major challenge to eradication is the reversion of OPV to neurovirulent mutants resulting in circulating vaccine-derived poliovirus (cVDPV). A novel, genetically stabilised OPV has been developed recently to stop the emergence and spread of cVDPV and OPV is being replaced by IPV in immunisation programs worldwide. Eradication of poliomyelitis is near to achievement and the expectation is that poliomyelitis will join smallpox as dreaded epidemic diseases of the past that will be consigned to history.
Coculture of porcine cumulus–oocyte complexes with porcine luteal cells during IVM: effect on oocyte maturation and embryo development
Authors: Teplitz G. M. , Lorenzo M. S. , Maruri A. , Cruzans P. R. , Carou M. C. , Lombardo D. M.
Published: October 2020

Coculture with somatic cells is an alternative to improve suboptimal invitro culture conditions. In pigs, IVF is related to poor male pronuclear formation and high rates of polyspermy. The aim of this study was to assess the effect of a coculture system with porcine luteal cells (PLCs) on the IVM of porcine cumulus–oocyte complexes (COCs). Abattoir-derived ovaries were used to obtain PLCs and COCs. COCs were matured invitro in TCM-199 with or without the addition of human menopausal gonadotrophin (hMG; C+hMG and C-hMG respectively), in coculture with PLCs from passage 1 (PLC-1) and in PLC-1 conditioned medium (CM). In the coculture system, nuclear maturation rates were significantly higher than in the C-hMG and CM groups, but similar to rates in the C+hMG group. In cumulus cells, PLC-1 coculture decreased viability, early apoptosis and necrosis, and increased late apoptosis compared with C+hMG. PLC-1 coculture also decreased reactive oxygen species levels in cumulus cells. After IVF, monospermic penetration and IVF efficiency increased in the PLC-1 group compared with the C+hMG group. After invitro culture, higher blastocysts rates were observed in the PLC-1 group. This is the first report of a coculture system of COCs with PLCs. Our model could be an alternative for the conventional maturation medium plus gonadotrophins because of its lower rates of polyspermic penetration and higher blastocysts rates, key issues in porcine invitro embryo production.
Measuring soil bulk density from shear wave velocity using piezoelectric sensors
Authors: Murad Mohammad Omar Faruk , Minasny Budiman , Malone Brendan , Crossing Kip
Published: October 2020

Bulk density and soil stiffness moduli are vital physical parameters related to soil compaction, porosity, moisture storage capacity, soil penetration resistance and structural integrity. Conventional methods for measuring soil density and stiffness moduli are destructive, time-consuming, complex, expensive and often require skilled operators to conduct the tests. A new soil density and stiffness moduli measurement technique that can evaluate soil density and stiffness moduli more rapidly, efficiently and precisely, at a low cost is introduced here. This study evaluated the use of shear wave velocity measurements using the piezoelectric extender and bender elements as a viable alternative to measure soil density and stiffness moduli of soil. To test this idea, soda-lime glass beads of <0.002, 0.04–0.07 and 1.00–1.30 mm in diameter were used to develop the empirical relationship between the shear wave velocity and the bulk density of soil in laboratory conditions. These empirical equations were then tested on sands and clayey soils for validation. Accuracy in terms of coefficient of determination (R2) and root mean squared error (RMSE) from the current and existing studies ranged within 0.91–0.93 and 0.073–0.177 g cm–3 respectively. Both shear and Young moduli were compared with the shear wave velocity of soil, with R2 and RMSE of 0.96–0.97 and 0.48–3.5 MPa respectively. The major advantage of this technique is that input and output signal data can be stored in a computer that can be used to calculate soil density and stiffness moduli automatically. This technique could play a vital role in improving crop yield and soil management practices.
Bifidobacterium
alters the gut microbiota and modulates the functional metabolism of T regulatory cells in the context of immune checkpoint blockade
Authors: Sun Shan , Luo Lingjie , Liang Wenhua , Yin Qian , Guo Jing , Rush Anthony M. , Lv Zhibao , Liang Qiming , Fischbach Michael A. , Sonnenburg Justin L. , Dodd Dylan , Davis Mark M. , Wang Feng
Published: October 2020

Significance

Many millions of people take probiotics over the counter, but very little is known about what they do and whether they really work. Here we show that in mice, introducing
Bifidobacterium
, one of the most commonly used probiotics, not only colonizes the gut, but also alters the entire microbiotic landscape. We previously found that this treatment rescues mice from an otherwise fatal inflammatory syndrome brought on by anti–CTLA-4 antibody, a checkpoint inhibitor that often causes autoimmunity in humans undergoing cancer treatment. Here we show that this is effect is due, at least in part, to the effect of this probiotic treatment on regulatory CD4
+
cells, whose metabolic and immune suppressive functions are altered. These CD4
+
regulatory T cells are known to be a key mechanism in the control of autoreactivity in the immune system in both mice and humans. Thus, we found a direct connection between probiotic treatment and one of the known principal mechanisms for controlling excess immune responses.
DOT1L-controlled cell-fate determination and transcription elongation are independent of H3K79 methylation
Authors: Cao Kaixiang , Ugarenko Michal , Ozark Patrick A. , Wang Juan , Marshall Stacy A. , Rendleman Emily J. , Liang Kaiwei , Wang Lu , Zou Lihua , Smith Edwin R. , Yue Feng , Shilatifard Ali
Published: October 2020

Significance

DOT1L is a histone methyltransferase that catalyzes histone H3K79 methylation, a chromatin modification that is correlated with active transcription. Inhibition of DOT1L’s catalytic activity has been studied for cancer therapy; however, the mechanisms underlying its function in development and cancer pathogenesis remain elusive. To understand the catalytic-dependent and catalytic-independent functions of DOT1L, we generated catalytic dead and null DOT1L embryonic stem cells and found that DOT1L, but not its catalytic activity, is required for establishing the proper expression signature of neural progenitor cells, suggesting that DOTlL has biological functions that are independent of its methyltransferase activity. We propose that the loss/degradation of DOT1L could be beneficial for cancer therapeutics.
Interactions between host genetics and gut microbiota determine susceptibility to CNS autoimmunity
Authors: Montgomery Theresa L. , Künstner Axel , Kennedy Josephine J. , Fang Qian , Asarian Lori , Culp-Hill Rachel , D’Alessandro Angelo , Teuscher Cory , Busch Hauke , Krementsov Dimitry N.
Published: October 2020

Significance

Increasing evidence suggests a role for the gut microbiome in autoimmune diseases, including multiple sclerosis. However, the impact of natural genetic variation in the mammalian host and other underlying mechanisms has been largely overlooked. We used a mouse model of natural genetic diversity to explore interactions between the host and the microbiome. Our results demonstrate a complex interplay between host genotype and gut microbiota in autoimmune disease, and identify a single commensal species capable of modifying disease susceptibility in a genetically susceptible host. Our studies underscore the need to consider host genetics and baseline gut microbiota composition in autoimmunity.
Nucleosome Positioning Regulates the Establishment, Stability, and Inheritance of Heterochromatin in
Saccharomyces cerevisiae
Authors: Saxton Daniel S. , Rine Jasper
Published: October 2020

Significance

Cells control which genes are actively providing instructions to the cell, and which genes are silenced. This regulation requires DNA to be wrapped around molecular scaffolds to form repeating units called nucleosomes. The organization of nucleosomes varies across the genome, with regular placement being a feature of regions adjacent to nucleosome-depleted regions (NDRs) and irregular positions more common elsewhere. To test whether regular positioning of nucleosomes is especially important in gene silencing, we altered the distance between NDRs within heterochromatin. These changes to NDR positioning revealed an oscillatory correlation between inter-NDR distance and poor nucleosome positioning. These defects in nucleosome positioning correlated with defects in silencing efficiency, indicating that regular placement of nucleosomes helps cells achieve gene silencing.
Acceleration of plague outbreaks in the second pandemic
Authors: Earn David J. D. , Ma Junling , Poinar Hendrik , Dushoff Jonathan , Bolker Benjamin M.
Published: October 2020

Significance

Epidemics of plague devastated Europe’s population throughout the Medieval and Renaissance periods. Genetic studies of modest numbers of skeletal remains indicate that the causative agent of all these epidemics was the bacteriumYersinia pestis, but such analyses cannot identify overall patterns of transmission dynamics. Analysis of thousands of archival records from London, United Kingdom, reveals that plague epidemics spread much faster in the 17th century than in the 14th century.
Prenatal and early-life exposure to the Great Chinese Famine increased the risk of tuberculosis in adulthood across two generations
Authors: Cheng Qu , Trangucci Robert , Nelson Kristin N. , Fu Wenjiang , Collender Philip A. , Head Jennifer R. , Hoover Christopher M. , Skaff Nicholas K. , Li Ting , Li Xintong , You Yue , Fang Liqun , Liang Song , Yang Changhong , He Jin’ge , Zelner Jonathan L. , Remais Justin V.
Published: October 2020

Significance

Food system collapse incurs major societal costs that may extend across generations. The Great Chinese Famine—widely acknowledged as the largest famine in human history—was associated with tremendous short-term adverse health consequences, yet its long-term effect on infectious disease incidence has not been estimated. We conducted a cohort analysis of >1 million pulmonary tuberculosis (PTB) cases in a major center of ongoing transmission that experienced high famine mortality, finding a substantial burden of active PTB potentially attributable to the famine in the birth cohort that experienced prenatal and early-life exposure to famine, as well in their putative offspring. The Great Chinese Famine occurred >60 y ago, yet continues to contribute to the high PTB burden in China.
Chaos in a simple model of a delta network
Authors: Salter Gerard , Voller Vaughan R. , Paola Chris
Published: October 2020

Significance

River deltas are threatened with rapid change due to human activity, highlighting the importance of predicting their dynamics. Based on a model of a simple delta network, we find that delta dynamics can be chaotic, implying a fundamental constraint on detailed long-term predictions of deltas. However, our estimates of the fundamental predictability horizon suggest substantial room for improvement in delta modeling. We test our model by using it to generate stratigraphy, translating our measure of predictability from time to vertical distance, and identifying the time scale required for long-term averages to become predictable. Although chaos precludes long-term prediction of deltas, the statistical behavior of deltas and their response to external changes such as human activity are predictable.
N
-
glycosylation shields
Phytophthora sojae
apoplastic effector PsXEG1 from a specific host aspartic protease
Authors: Xia Yeqiang , Ma Zhenchuan , Qiu Min , Guo Baodian , Zhang Qi , Jiang Haibin , Zhang Baiyu , Lin Yachun , Xuan Mingrun , Sun Liang , Shu Haidong , Xiao Junhua , Ye Wenwu , Wang Yan , Wang Yiming , Dong Suomeng , Tyler Brett M. , Wang Yuanchao
Published: October 2020

Significance

The apoplastic space is the initial battlefield in plant–microbe interactions. However, the molecular mechanisms underlying how apoplastic immunity controls pathogen invasion is still largely unknown. Here, we show that soybean secretes an apoplastic aspartic protease, GmAP5, that binds to and degrades PsXEG1 to block its contribution to virulence.
Phytophthora sojae
, however, employs N-glycosylation as a shield to protect PsXEG1 from degradation by GmAP5. N-glycosylation of PsXEG1 also attenuates the binding by the inhibitor GmGIP1. Our result uncovers an additional layer of defense and counterdefense centered on PsXEG1, highlighting an example in which N
-
glycosylation of a pathogen virulence factor tips the balance of an arms race in host–pathogen conflicts.
Initial economic damage from the COVID-19 pandemic in the United States is more widespread across ages and geographies than initial mortality impacts
Authors: Polyakova Maria , Kocks Geoffrey , Udalova Victoria , Finkelstein Amy
Published: October 2020

Significance

A full picture of the COVID-19 pandemic requires information on how its impact on lives and on livelihoods relates across different groups. We therefore estimate excess all-cause mortality and employment displacement in April 2020 nationally and separately by state and by age group. Initial economic damages from the pandemic are more widespread across groups than deaths, which were primarily concentrated in a few states and among the oldest old. While the two states with the largest mortality increase account for about half of national excess mortality, the two most economically affected states account for only 7% of national economic damages. These findings suggest that policy responses to contain the pandemic involve trade-offs across different demographic and geographic groups.
Liquid-liquid phase separation promotes animal desiccation tolerance
Authors: Belott Clinton , Janis Brett , Menze Michael A.
Published: October 2020

Significance

Recent research has shown that intracellular proteinaceous condensates (membraneless organelles [MLOs]) are involved in various processes, ranging from Alzheimer’s disease to RNA processing, and here we demonstrate that this phenomenon governs a mechanism of anhydrobiosis. The proteinAfrLEA6 is found in the desiccation-tolerant life stage of the animal extremophileArtemia franciscana,and the protein engages in two distinct molecular mechanisms to confer protection during water loss.AfrLEA6 forms MLOs that may act as protective nodes for desiccation-sensitive proteins, while a cytosolic fraction of the protein promotes structural integrity of cells during anhydrobiosis. These findings significantly advance our understanding of “life without water” and promote transformative advancements in various fields, ranging from cell preservation technology to improvement of crop desiccation tolerance.
Scanning digital oil immersion lithography providing high-speed large area patterning with diffraction limited sub-micron resolution
Authors: Jakkinapalli Aravind , Bhaskar Arun , Wen Sy-Bor
Published: October 2020

A high numerical aperture (NA) scanning digital oil immersion lithography scheme is proposed and demonstrated in this study. To successfully conduct the scanning digital oil immersion lithography, immersion oil should be removed from the photoresist layer before the development process. Also, uniformity of the projected light patterns becomes crucial in the quality of this high NA photolithography. To solve these issues, we developed a cleaning procedure for the immersion oil and an intensity calibration scheme to achieve a highly uniform intensity distribution of the projected patterns. With these preparations, we were able to achieve 400 nm resolution large area patterning with the developed scanning digital oil immersion lithography system and a better than 200 nm resolution in the single line patterning. Also, with a double layered photoresist scheme and our lab-prepared photoresist, we successfully achieved large area lift-off patterns of 400 nm metallic dot arrays through the scanning digital oil immersion lithography system.
Entanglement and correlation in two-nucleon systems
Authors: Kruppa A T , Kovács J , Salamon P , Legeza Ö
Published: October 2020

We examine mode entanglement and correlation of two fermionic particles analytically and numerically. We study the one- and two-mode entropies and a global characteristic, the one-body entanglement entropy considering angular momentum coupled state with a single configuration. We show that with rearrangement of the single-particle orbitals the Slater decomposition can be obtained which can also be applied for configuration mixing subject to special restriction. With the help of the Slater decomposition, we derive analytical expressions for the entanglement measures, which becomes very simple for zero total angular momentum. The Slater decomposition allows us to define associated modes, and it turns out that they have identical one- and two-mode entropies. Furthermore, we show that specific single configurations describe maximally entangled states when the total angular momentum is zero. The numerical shell model study of two valence neutrons in the sd shell is revealed that the one-body entanglement entropy of the ground state is close to the maximal value, and the associated modes have the largest mutual information.