bluuebunny/crossref_metadata_2025 huggingface dataset:
Light intensity-dependence studies on the role of surface deposits for titania-photocatalyzed oxygen evolution: Are they really cocatalysts?
Authors: Ketwong Pradudnet , Yoshihara Shun , Takeuchi Shugo , Takashima Mai , Ohtani Bunsho
Published: September 2020

The effects of surface loading of iridium(II) oxide (IrO2), manganese(IV) oxide (MnO2), and cobalt(II) phosphate (CoPi) on the rate of photocatalytic oxygen evolution by anatase or rutile titania particles suspended in aqueous solutions of an electron acceptor, iodate ions, were studied by light intensity-dependence (LID) kinetic analyses. Although the role of these deposits has been reported to be a cocatalyst without showing results of any kinetic analysis, the present LID kinetic study suggested that the deposits may act as a “positive-hole capturer” for oxygen evolution, not as a cocatalyst for both metal oxides and CoPi. Further studies on the effects of loading amount, deposit types, titania crystalline type, and titania-particle size on the reaction order were also performed by LID analysis based on the proposed kinetic model. The observed LID behaviors could be interpreted consistently using a virtual parameter of “effective volume” as the target volume of photoabsorption by one positive-hole-bearing titania particle to govern the probability of two positive-hole accumulations in a titania particle.
Introduction of misfit dislocations into strained-layer GaAs/InxGa1–xAs/GaAs heterostructures by mechanical bending
Authors: Liu X. W. , Hopgood A. A.
Published: September 2020

The stability of strained-layer heterostructure lasers can be assessed by their response to stimuli for the introduction of dislocations. Three-point bending at elevated temperatures has been applied to GaAs/InxGa1−xAs/GaAs heterostructures to apply such a thermomechanical stimulus. In each case, the middle-layer thickness was below the critical thickness predicted by the Matthews–Blakeslee model, so that the pre-test structures were fully strained with no observed misfit dislocations. The tensile stress of 46.4 MPa produced during the tests resulted in the formation of 60° misfit dislocations whose configurations changed according to the alignment of the bending axis. For bending in the [110] orientation, the misfit dislocations formed parallel to each other and to the bending axis. For [100] bending, they formed an orthogonal pattern with each dislocation at 45° to the bending axis. In each case, these misfit dislocations caused relaxation of the strained-layer structures, even though the unloaded structures had been considered thermodynamically stable and the test temperatures were lower than those used during the original fabrication of the structures. These findings challenge existing assumptions of strained-layer stability and have implications for the design of lasers intended to be “buried and forgotten” in optical telecommunications.
On the role of the zirconia/ceria interface in the degradation of solid oxide electrolysis cells
Authors: Zhang Qian , Park Beom-Kyeong , Barnett Scott , Voorhees Peter
Published: September 2020

Gd-doped Ceria (GDC) barrier layers are widely used in solid oxide electrolysis cells to prevent reactions between the Y-stabilized Zirconia (YSZ) electrolyte and oxygen electrode. In some cases, electrolysis operation causes fracture near the GDC/YSZ interface. Here, we explain this effect using a numerical calculation, showing that a peak oxygen pressure is observed near the GDC/YSZ interface during electrolysis operation. Moreover, GDC/YSZ interdiffusion and possible zirconate phase formation occurring during electrode firing yield a low oxygen ion conductivity region that introduces a much higher peak oxygen partial pressure at the interdiffusion layer/YSZ interface, thereby exacerbating degradation. The results indicate that the peak pressure can be reduced and, thereby, damage can be mitigated by altering processing in order to minimize interdiffusion, decreasing the GDC layer thickness, and reducing oxygen electrode polarization resistance or altering electrolyte transport properties, e.g., changing the Gd doping level of GDC to increase the oxygen vacancy diffusivity.
Two-dimensional swarm formation in time-invariant external potential: Modeling, analysis, and control
Authors: Wang Yanran , Hikihara Takashi
Published: September 2020

Cluster formation has been observed in many organisms in nature. It has the desirable properties for designing energy efficient protocols for Wireless Sensor Networks (WSNs). In this paper, we present a new approach for energy efficient WSN protocols that investigates how the cluster formation of sensors responds to the external time-invariant energy potential. In this approach, the necessity for data transmission to the Base Station is eliminated, thereby conserving energy for WSNs. We define swarm formation topology and estimate the curvature of an external potential manifold by analyzing the change of the swarm formation in time. We also introduce a dynamic formation control algorithm for maintaining defined swarm formation topology in the external potential.
Large eddy simulations of solitons colliding with intrusions
Authors: Ottolenghi Luisa , Adduce Claudia , Roman Federico , la Forgia Giovanni
Published: September 2020

The dynamics of lock-release Intrusive Gravity Currents (IGCs) generating Internal Solitary Waves (ISWs) are investigated by three-dimensional large eddy simulations. We set the numerical, laboratory-scale domain in order to release a uniform fluid in multi-layer, stratified ambient, exciting pycnocline displacements. By adopting different initial settings, we analyzed the influence of the ambient stratification on both IGCs and ISWs features. We present the main flow dynamics and the time evolution of IGC and ISW front and trough positions, respectively. During the simulations, the ISW is allowed to reach the vertical wall at the end of the domain, and it undergoes reflection. We then analyzed the interaction between the IGC and the reflected ISW: the wave is observed to accelerate as it is pushed upwards by the intrusion, which, in turns, flows below the ISW, decelerating. By analyzing instantaneous velocity fields and flow rates, we found that during this interaction, the ISW increases its celerity in response of the reduced area available for its propagation, partially occupied by the intrusion, and because the velocity field in the IGC interface surroundings acts to facilitate the ISW passage.
Ring-polymer, centroid, and mean-field approximations to multi-time Matsubara dynamics
Authors: Jung Kenneth A. , Videla Pablo E. , Batista Victor S.
Published: September 2020

Based on a recently developed generalization of Matsubara dynamics to the multi-time realm, we present a formal derivation of multi-time generalizations of ring-polymer molecular dynamics, thermostatted ring-polymer molecular dynamics (TRPMD), centroid molecular dynamics (CMD), and mean-field Matsubara dynamics. Additionally, we analyze the short-time accuracy of each methodology. We find that for multi-time correlation functions of linear operators, (T)RPMD is accurate up to order t3, while CMD is only correct up to t, indicating a degradation in the accuracy of these methodologies with respect to the single-time counterparts. The present work provides a firm justification for the use of path-integral-based approximations for the calculation of multi-time correlation functions.
A hybrid (Al)GaAs-LiNbO3 surface acoustic wave resonator for cavity quantum dot optomechanics
Authors: Nysten Emeline D. S. , Rastelli Armando , Krenner Hubert J.
Published: September 2020

A hybrid device comprising a (Al)GaAs quantum dot heterostructure and a LiNbO3 surface acoustic wave resonator is fabricated by heterointegration. High acoustic quality factors Q>4000 are demonstrated for an operation frequency f≈300 MHz. The measured large quality factor-frequency products Q×f>1012 ensure the suppression of decoherence due to thermal noise for temperatures exceeding T>50 K. Frequency and position dependent optomechanical coupling of single quantum dots and resonator modes is observed.
Localization model description of the interfacial dynamics of crystalline Cu and Cu64Zr36 metallic glass films
Authors: Mahmud Gazi , Zhang Hao , Douglas Jack F.
Published: September 2020

Recent studies of structural relaxation in Cu–Zr metallic glass materials having a range of compositions and over a wide range of temperatures and in crystalline UO2 under superionic conditions have indicated that the localization model (LM) can predict the structural relaxation time τα of these materials from the intermediate scattering function without any free parameters from the particle mean square displacement ⟨r2⟩ at a caging time on the order of ps, i.e., the “Debye–Waller factor” (DWF). In the present work, we test whether this remarkable relation between the “fast” picosecond dynamics and the rate of structural relaxation τα in these model amorphous and crystalline materials can be extended to the prediction of the local interfacial dynamics of model amorphous and crystalline films. Specifically, we simulate the free-standing amorphous Cu64Zr36 and crystalline Cu films and find that the LM provides an excellent parameter-free prediction for τα of the interfacial region. We also show that the Tammann temperature, defining the initial formation of a mobile interfacial layer, can be estimated precisely for both crystalline and glass-forming solid materials from the condition that the DWFs of the interfacial region and the material interior coincide.
Metabolic tuning of inhibition regulates hippocampal neurogenesis in the adult brain
Authors: Wang Xinxing , Liu Hanxiao , Morstein Johannes , Novak Alexander J. E. , Trauner Dirk , Xiong Qiaojie , Yu Yuguo , Ge Shaoyu
Published: September 2020

Significance

Our the brain actively responds to changes in the environment by remodeling neural circuits. One important aspect of neuroplasticity is adult neurogenesis, which involves the generation, survival, and incorporation of new neurons into existing circuits and is unique to two discrete areas of the mammalian brain. The hippocampus, critical for learning and memory, is one such area that exhibits ongoing neurogenesis throughout an individual’s lifetime. Although recent studies have confirmed that hippocampal behaviors regulate neurogenesis, the mechanistic pathways governing that regulatory activity remain poorly understood. In this work, we found that hippocampal behaviors increase inhibitory circuit activity through a metabolic pathway, and established a computational model to quantitively model the relationship between circuit activity and control of hippocampal neurogenesis.
Deep profiling of protease substrate specificity enabled by dual random and scanned human proteome substrate phage libraries
Authors: Zhou Jie , Li Shantao , Leung Kevin K. , O’Donovan Brian , Zou James Y. , DeRisi Joseph L. , Wells James A.
Published: September 2020

Significance

Over 600 proteases work together to maintain the normal functions and homeostasis of cells in the human body. Determining protease specificity and their natural substrates is critical to understanding their biology. We present a facile, inexpensive, general, and global means to profile the natural specificity of human proteases at unprecedented depth. Using two genetically encoded substrate phage libraries, we deeply profile the substrate specificities of two important protease families, caspases involved in cell death and ADAMs family proteases that shed membrane proteins. We validated our results by recapitulating and expanding on known consensus substrates with up to 1,000-fold greater coverage.
Emergence of the Southeast Asian islands as a driver for Neogene cooling
Authors: Park Yuem , Maffre Pierre , Goddéris Yves , Macdonald Francis A. , Anttila Eliel S. C. , Swanson-Hysell Nicholas L.
Published: September 2020

Significance

The Southeast Asian islands are a modern-day hotspot of CO
2
consumption via silicate weathering. Since ∼15 million years ago, these islands have been increasing in size at the same time that Earth’s climate has been cooling. Here, we test the hypothesis that this global cooling could have been driven by tectonic emergence of the Southeast Asian islands. Using a compilation of paleoshorelines, in conjunction with a coupled silicate weathering and climate model, we find that this emergence is associated with a large decrease in
p
CO
2
. Without these changes in tropical island paleogeography, there would not have been large Northern Hemisphere ice sheets as a defining feature of Earth’s climate over the past 3 million years.
Speech can produce jet-like transport relevant to asymptomatic spreading of virus
Authors: Abkarian Manouk , Mendez Simon , Xue Nan , Yang Fan , Stone Howard A.
Published: September 2020

Significance

Medical reports and news sources raise the possibility that flows created during breathing, speaking, laughing, singing, or exercise could be the means by which asymptomatic individuals contribute to spread of the SARS-CoV-2 virus. We use experiments and simulations to quantify how exhaled air is transported in speech. Phonetic characteristics introduce complexity to the airflow dynamics and plosive sounds, such as “P,” produce intense vortical structures that behave like “puffs” and rapidly reach 1 m. However, speech, corresponding to a train of such puffs, creates a conical, turbulent, jet-like flow and easily produces directed transport over 2 m in 30 s of conversation. This work should inform public health guidance for risk reduction and mitigation strategies of airborne pathogen transmission.
Study of non-equilibrium dendrite growth in an undercooled alloy
Authors: An Hongen , Xu Xiaolong
Published: September 2020

Nonequilibrium thermodynamics and transportation kinetics near the propagating solid–liquid interface dominates the rapid solidification process, which is far from a thermodynamically stable state. Rapid solidification process can be described more precisely using quantitative thermodynamic calculation of phase diagram with nonlinear liquidus and solidus and evaluating the nonequilibrium effect in diffusion kinetics. Based on these basic principles, we have used a current nonequilibrium dendrite growth model to describe the rapid solidification process and the recalescence temperature of deeply undercooled alloys. Evolution of the key fundamental solidification parameters was also evaluated. The experimental data agree well with the model prediction.
A relativistic paradox and its resolution or who drives the entropy current between two bodies in relative motion?
Authors: Herrmann Friedrich , Pohlig Michael
Published: September 2020

We discuss a paradox from the field of relativistic thermodynamics: two heat reservoirs of the same proper temperature move against each other. One is at rest in the inertial reference frame S
A, the other in S
B. For an observer, no matter in which of the two reference frames he is at rest, the temperatures of the two reservoirs are different. One might, therefore, conclude that a thermal engine can be operated between the reservoirs. However, the observers in S
A and S
B do not agree upon the direction of the entropy flow: from S
A to S
B, or from S
B to S
A. The resolution of the paradox is obtained by taking into account that the ‘drive’ of an entropy current is not simply a temperature difference, but the difference of a quantity that depends on both temperature and velocity.
Particle recirculating orbits within microvortices using microfluidics
Authors: Shen Feng , Li Zonghe , Xue Sen , Li Mengqi , Liu Zhaomiao
Published: September 2020

Particle/cell separation from a mixture using a hydrodynamic vortex has been attracting much interest for the isolation of circulating tumor cells in basic biological studies and clinical applications. However, some issues regarding the particle recirculating orbits within the vortex in microcavities remain unclear. In this work, using micro-particle image velocimetry and a high-speed microscopy system, we quantitatively investigate the effects of inlet Reynolds numbers (Re) on the microcavity flow characteristics and particle recirculating behavior. The results show that due to the evolution of microcavity flow patterns (Re = 15–313), the particle orbit topology expands gradually, developing from a single small orbit (Re = 39–79) to a single semicircular orbit (98–117), then to alternating double orbits (Re = 136–215), and at last to a single large orbit (Re = 254–352). The alternating double orbits are observed for the first time. The particle orbit periods and topologies (lengths and area) have also been characterized. Moreover, the variations of the recirculating particle velocity are also quantitatively measured. The results deepen the fundamental understanding of particle recirculating behavior and could provide useful guidance for vortex-based microfluidics.
A mixed-valent metal–organic ladder linked by pyrazine
Authors: Otake Ken-ichi , Otsubo Kazuya , Kitagawa Hiroshi
Published: September 2020

We report the synthesis, characterization, and electronic state of a novel mixed-valent metal–organic ladder (MOL) linked by pyrazine (pz). Single-crystal x-ray studies revealed that the MOL has a two-legged ladder-shaped framework, which is composed of a pz-connected Pt dimer with bridging Br ions. The electronic state of the MOL was investigated using x-ray and spectroscopic techniques; the MOL was found to have an electronic state that corresponds to the mixed-valence state of PtII and PtIV. Furthermore, the intervalence charge transfer energy of the MOL has lower than that expected from the tendency of a similar halogen-bridged mixed-valence MOL owing to its unique ‘zig-zag’-shaped legs. These results provide a new insight into the physical and electronic properties of MOL systems.
C60 self-orientation on hexagonal boron nitride induced by intermolecular coupling
Authors: Guo Haojie , Martínez-Galera Antonio J , Gómez-Rodríguez Jose M
Published: September 2020

A deep grasp of the properties of the interface between organic molecules and hexagonal boron nitride (h-BN) is essential for the full implementation of these two building blocks in the next generation of electronic devices. Here, using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), we report on the geometric and electronic features of C60 evaporated on a single layer of h-BN grown on a Rh(110) surface under ultra-high vacuum. Two different molecular assemblies of C60 on the h-BN/Rh(110) surface were observed. The first STM study at room temperature (RT) and at low temperatures (40 K) looked at the molecular orientation of C60 on a two-dimensional layered material. Intramolecular-resolution images demonstrate the existence of a phase transition of C60 over the h-BN/Rh(110) surface similar to that found on bulk solid C60. At RT molecules exhibit random orientations, while at 40 K such rotational disorder vanishes and they adopt a common orientation over the h-BN/Rh(110) surface. The decrease in thermal energy allows recognition between C60 molecules, and they become equally oriented in the configuration at which the van der Waals intermolecular interactions are optimized. Bias-dependent submolecular features obtained by means of high-resolution STM images are interpreted as the highest occupied and lowest unoccupied molecular orbitals. STS data showed that fullerenes are electronically decoupled from the substrate, with a negligible charge transfer effect if any. Finally, the very early stages of multilayer growth were also investigated.
High frequency sheath modulation and higher harmonic generation in a low pressure very high frequency capacitively coupled plasma excited by sawtooth waveform
Authors: Sharma Sarveshwar , Sirse Nishant , Turner Miles M
Published: September 2020

A particle-in-cell simulation study is performed to investigate the discharge asymmetry, higher harmonic generations and electron heating mechanism in a low pressure capacitively coupled plasma excited by a saw-tooth like current waveform for different driving frequencies; 13.56 MHz, 27.12 MHz, and 54.24 MHz. Two current densities, 50 A m−2 and 100 A m−2 are chosen for a constant gas pressure of 5 mTorr in argon plasma. At a lower driving frequency, high frequency modulations on the instantaneous sheath electric field near to the grounded electrode are observed. These high frequency oscillations create multiple ionization beam like structures near to the sheath edge that drives the plasma density in the discharge and responsible for discharge/ionization asymmetry at lower driving frequency. Conversely, the electrode voltage shows higher harmonics generation at higher driving frequencies and corresponding electric field transients are observed into the bulk plasma. At lower driving frequency, the electron heating is maximum near to the sheath edge followed by electron cooling within plasma bulk, however, alternate heating and cooling i.e. burst like structures are obtained at higher driving frequencies. These results suggest that electron heating in these discharges will not be described accurately by simple analytical models.
Importance of shallow hydrogenic dopants and material purity of ultra-wide bandgap semiconductors for vertical power electron devices
Authors: Zhang Yuewei , Speck James S
Published: September 2020

Ultra-wide bandgap (UWBG) semiconductors are attracting increasing research interest for power device applications. While promising results have been reported for various materials, it remains unclear which material and technology will succeed. Many figure of merits (FOMs) were derived for power device applications to guide material choices, including the widely used Baliga’s FOM (BFOM) to describe the resistive loss of power devices, and Baliga’s high-frequency FOM (BHFFOM) to further consider the switching loss. However, key underlying assumptions for those widely cited FOMs, including the assumption of shallow hydrogenic dopants, tend to fail for UWBG semiconductors. In this work, we revisit several important FOMs in describing vertical power electronics to properly account for both incomplete ionization and background compensation effects. We suggest that it is necessary to include the dopant ionization term (for example n/Nd
in an n-drift layer) for both BFOM and BHFFOM to fully capture the potential of the UWBG semiconductors for power device applications. Incomplete dopant ionization in materials like diamond and AlN substantially lowers their FOMs for power switching, leading to high conductive and switching losses. Due to the availability of shallow donors, low background impurity compensation, and bulk substrates, β-Ga2O3 promises the best performance among the investigated materials. The modified FOMs offer a valuable guidance in material choices for power device applications.
Boosting spatial resolution by incorporating periodic boundary conditions into single-distance hard-x-ray phase retrieval
Authors: Paganin David M , Favre-Nicolin Vincent , Mirone Alessandro , Rack Alexander , Villanova Julie , Olbinado Margie P , Fernandez Vincent , da Silva Julio C , Pelliccia Daniele
Published: September 2020

A simple coherent-imaging method due to Paganin et al is widely employed for phase–amplitude reconstruction of samples using a single paraxial x-ray propagation-based phase-contrast image. The method assumes that the sample-to-detector distance is sufficiently small for the associated Fresnel number to be large compared to unity. The algorithm is particularly effective when employed in a tomographic setting, using a single propagation-based phase-contrast image for each projection. Here we develop a simple extension of the method, which improves the reconstructed contrast of very fine sample features. This provides first-principles motivation for boosting fine spatial detail associated with high Fourier frequencies, relative to the original method, and was inspired by several recent works employing empirically-obtained Fourier filters to a similar end.
Evaluation of the compression behavior of recycled marine plastic waste-reinforced concrete
Authors: Lee Dong-Ha , Kim Hee-Tae , Kim Jeong-Dae , Kim Jeong-Hyeon , Kim Seul-Kee , Lee Jae-Myung
Published: September 2020

Marine debris is a serious and worldwide environmental problem. In particular, most marine debris is comprised of plastics, which decompose in natural conditions for decades to hundreds of years. They have been distributed across the ocean since the 1970s. Marine plastics have a very low recycling rate due to concerns associated seawater and attachment of microorganisms. Collected plastics are subjected to a pre-treatment process that is not efficient due to the heat generated during grinding. For this reason, cryogenic grinding using liquid nitrogen has been developed. In this study, they were applied to concrete as a marine waste treatment method. In particular, the waste existing in bulk was subjected to cryogenic grinding to evaluate the strength of the concrete according to the particle size. Two types of fiber and two types of bulk plastics that account for a significant portion of marine plastics were tested to evaluate the resulting performance of the concrete. The experimental results confirmed that the strength and ductility increased when adding plastic particles to cement via cryogenic grinding and that the strength increased by 30% or more for a specific plastic.
Machine learning for BMS analysis and optimisation
Authors: Mesa-Jiménez J J , Stokes L , Yang Q , Livina V N
Published: September 2020

In large buildings, linking heating, cooling or ventilation systems between themselves and to physical spaces is a very time-consuming task that requires highly skilled engineering knowledge, as all these systems are interconnected and they have a certain influence to each other (ventilation systems are often connected to heating and cooling), which often makes task of locating the sources of error or anomalies very time consuming and difficult as they are performed manually. A different approach would be to work out relationships and equipment linkage from time series data provided by the sensors, thus inferring equipment links from which anomalies can be traced back to the source more easily. This paper proposes a data-based solution to obtain equipment relationships based on cross-correlations to relate Air Handling Units (AHUs) to their respective areas of operation. We also propose a methodology, in particular for AHUs, to identify whether or not to trust correlations based on the difference between supply and return temperature. A case study is presented based a large building with 16 AHU systems.
Reducing Bias Due to Exposure Measurement Error Using Disease Risk Scores
Authors: Richardson David B , Keil Alexander P , Cole Stephen R , Edwards Jessie K
Published: September 2020

Suppose that an investigator wants to estimate an association between a continuous exposure variable and an outcome, adjusting for a set of confounders. If the exposure variable suffers classical measurement error, in which the measured exposures are distributed with independent error around the true exposure, then an estimate of the covariate-adjusted exposure-outcome association may be biased. We propose an approach to estimate a marginal exposure-outcome association in the setting of classical exposure measurement error using a disease score–based approach to standardization to the exposed sample. First, we show that the proposed marginal estimate of the exposure-outcome association will suffer less bias due to classical measurement error than the covariate-conditional estimate of association when the covariates are predictors of exposure. Second, we show that if an exposure validation study is available with which to assess exposure measurement error, then the proposed marginal estimate of the exposure-outcome association can be corrected for measurement error more efficiently than the covariate-conditional estimate of association. We illustrate both of these points using simulations and an empirical example using data from the Orinda Longitudinal Study of Myopia (California, 1989–2001).
Baseline Drinking Patterns in Non-Treatment Seeking Problem Drinkers
Authors: Baskerville Wave-Ananda , Nieto Steven J , Ho Diana , Towns Brandon , Grodin Erica N , Li Caesar , Burnette Elizabeth , Donato Suzanna , Ray Lara A
Published: September 2020

Aims

Natural processes of change have been documented in treatment-seekers who begin to reduce their drinking in anticipation of treatment. The study examined whether non-treatment-seeking problem drinkers would engage in drinking reduction in anticipation of participating in a research study.

Methods

Non-treatment-seeking problem drinkers (n = 935) were culled from five behavioral pharmacology studies. Participants reported on their alcohol use during the past 30 days using the Timeline Followback. Cluster analysis identified distinct groups/clusters based on drinking patterns over the 30-day pre-visit period. The identified clusters were compared on demographic and clinical measures.

Results

Three distinct clusters were identified (a) heavy-decreasing drinking group (n = 255, 27.27%); (b) a moderate-stable drinking group (n = 353, 37.75%) and (c) low-stable drinking group (n = 327, 34.97%). The three clusters differed significantly on a host of measures including pre-visit drinking (age at first drink, drinking days, drinks per week, drinks per drinking day), alcohol use severity, alcohol craving, readiness for change, depression and anxiety levels. These differences were alcohol dose-dependent such that the heavier drinking group reported the highest levels on all constructs, followed by the moderate group, and the low drinking group last.

Conclusions

Baseline drinking patterns of non-treatment-seekers were generally stable and pre-visit reductions were only observed among the heavy drinking group. This generally stable pattern stands in contrast to previous reports for treatment-seeking samples. Nevertheless, the heavier drinking group, which is most similar to treatment-seekers, displayed pre-study drinking reduction. Overall, naturalistic processes of change may pose less of a threat to randomization and testing in this population.
Artificial Neural Networks (ANNs) and Partial Least Squares (PLS) Regression in the Quantitative Analysis of Respirable Crystalline Silica by Fourier-Transform Infrared Spectroscopy (FTIR)
Authors: Salehi Mina , Zare Asma , Taheri Ali
Published: September 2020

Respirable crystalline silica (RCS) overexposure can lead to the development of silicosis which is a chronic, irreversible, potentially fatal respiratory disease. The most significant prerequisite for any silica exposure control plan is an accurate occupational exposure assessment. The results of crystalline silica analysis are often affected by other mineral interferences and are influenced by an analyst’s knowledge of mineralogy to accurately interpret infrared spectra and correct matrix interferences. Partial least squares (PLS) and artificial neural networks (ANNs) are two multivariate calibration methods to overcome the problem of spectral interferences without the need for an analyst intervention. The performance of these two methods in quantitative analysis of quartz in the presence of mineral interferences was evaluated and compared in this study. Fifty mixtures with different crystalline silica content ratios were prepared by mixing quartz with four common mineral interferences including kaolinite, albite, muscovite, and amorphous silica. Fourier-transform infrared spectra of the mixtures were split into training and test datasets. The optimal architecture of the ANN model was achieved using a two-level full factorial design experiment and data were modeled using ANN and PLS regression analysis. Root mean squared error of prediction values of 1.69 and 6.12 µg quartz for ANN and PLS models, respectively, revealed the fact that the both models performed very well in quantitative analysis of quartz in the presence of mineral interferences, with a better relative performance of the ANN model which can be related to the inherent nonlinear predictive ability of ANNs. Given the excellent predictive ability of the ANN model which can deal with a completely overlapped peak without any need of user’s intervention, it is recommended that the ANN model be optimized in future studies and utilized for reliable and rapid on-field assessment of RCS exposure.
Influence of niche breadth and position on the historical biogeography of seafaring scincid lizards
Authors: Richmond Jonathan Q , Ota Hidetoshi , Grismer L Lee , Fisher Robert N
Published: September 2020

Niche breadth and position can influence diversification among closely related species or populations, yet limited empirical data exist concerning the predictability of the outcomes. We explored the effects of these factors on the evolution of the Emoia atrocostata species group, an insular radiation of lizards in the western Pacific Ocean and Indo-Australasia composed of both endemic and widespread species that differ in niche occupancy. We used molecular data and phylogeographical diffusion models to estimate the timing and patterns of range expansion, and ancestral reconstruction methods to infer shifts in ecology. We show evidence of multidirectional spread from a centre of origin in western Micronesia, and that the phyletic diversity of the group is derived from a putative habitat specialist that survives in the littoral zone. This species is composed of paraphyletic lineages that represent stages or possible endpoints in the continuum toward speciation. Several descendant species have transitioned to either strand or interior forest habitat, but only on remote islands with depauperate terrestrial faunas. Our results suggest that the atrocostata group might be in the early phases of a Wilsonian taxon cycle and that the capacity to tolerate salt stress has promoted dispersal and colonization of remote oceanic islands. Divergence itself, however, is largely driven by geographical isolation rather than shifts in ecology.
Unity in diversity: phylogenetics and taxonomy of Rhabdoweisiaceae (Dicranales, Bryophyta)
Authors: Fedosov Vladimir E , Fedorova Alina V , Larraín Juan , Santos Marina B , Stech Michael , Kučera Jan , Brinda John C , Tubanova Dolgor Ya , Von Konrat Matt , Ignatova Elena A , Ignatov Michael S
Published: September 2020

Molecular phylogenetic reconstructions of Rhabdoweisiaceae based on plastid (trnS-rps4 and trnL-F) and mitochondrial (nad5) DNA sequences and a comprehensive taxon sampling were performed, including 15 out of 16 genera currently attributed to the family, taxa recently found belonging to Rhabdoweisiaceae and expanded outgroups from related families of Dicranidae. The suggested revised delimitation of the family comprises Camptodontium (previously referred to Dicranaceae), three subaquatic species currently classified in Blindia (Seligeriaceae), and Glyphomitrium (previously referred to Ptychomitriaceae, Erpodiaceae or its own family) and Eucamptodon perichaetialis (the type species of the genus, previously referred to Dicnemonaceae). The emended delimitation of Rhabdoweisiaceae thus adds to the already high morphological heterogeneity resulting from the divergent evolution of specialized traits in different lineages of epiphytes and saxicolous hygrophytes. Taxonomic inferences from the phylogenetic analyses include segregation of three new genera, Pseudoblindia (for species currently recognized as Kiaeria falcata, Blindia robusta, B. lewinskyae and B. inundata), Ripariella (for Kiaeria riparia) and Brideliella (for Oncophorus wahlenbergii, O. demetrii and Symblepharis lindigii). Hollia is reinstated for the dicnemonoid Australasian species previously classified in Eucamptodon. Additionally, we propose to merge (1) Oreoweisia, Pocsiella and Pseudohyophila with Cynodontium, and (2) Kiaeria s.s. with Arctoa. Furthermore, we propose to limit Oncophorus to O. virens and O. integerrimus and expand the circumscription of Symblepharis to accommodate O. crispifolius, O. dendrophilus, O. elongatus and O. raui. The generic status and inclusion in Rhabdoweisiaceae are confirmed for Cnestrum and the recently described Notocynodontium, and the exclusion of Amphidium, Dichodontium, Holodontium and Hymenoloma from the family is supported.
Subthalamic stimulation impairs stopping of ongoing movements
Authors: Lofredi Roxanne , Auernig Georg Cem , Irmen Friederike , Nieweler Johanna , Neumann Wolf-Julian , Horn Andreas , Schneider Gerd-Helge , Kühn Andrea A
Published: September 2020

The subthalamic nucleus is part of a global stopping network that also includes the presupplementary motor area and inferior frontal gyrus of the right hemisphere. In Parkinson’s disease, subthalamic deep brain stimulation improves movement initiation and velocity, but its effect on stopping of ongoing movement is unknown. Here, we examine the relation between movement stopping and connectivity of stimulation volumes to the stopping network. Stop and go times were collected in 17 patients with Parkinson’s disease on and off subthalamic stimulation during visually cued initiation and termination of continuous, rotational movements. Deep brain stimulation contacts were localized; the stimulation volume computed and connectivity profiles estimated using an openly available, normative structural connectome. Subthalamic stimulation significantly increased stop times, which correlated with the connectivity of the stimulation volume to presupplementary motor area and inferior frontal gyrus of the right hemisphere. The robustness of this finding was validated using three separate analysis streams: voxel-wise whole-brain connectivity, region of interest connectivity and a tract-centred method. Our study sheds light on the role of the fronto-subthalamic inhibitory triangle in stopping of ongoing movements and may inspire circuit based adaptive stimulation strategies for control of stopping impairment, possibly reflected in stimulation-induced dyskinesia.
Df(h15q13)/+ Mouse Model Reveals Loss of Astrocytes and Synaptic-Related Changes of the Excitatory and Inhibitory Circuits in the Medial Prefrontal Cortex
Authors: Al-Absi Abdel-Rahman , Qvist Per , Glerup Simon , Sanchez Connie , Nyengaard Jens R
Published: September 2020

The 15q13.3 deletion is associated with multiple neurodevelopmental disorders including epilepsy, schizophrenia, and autism. The Df(h15q13)/+ mouse model was recently generated that recapitulates several phenotypic features of the human 15q13.3 deletion syndrome (DS). However, the biological substrates underlying these phenotypes in Df(h15q13)/+ mice have not yet been fully characterized. RNA sequencing followed by real-time quantitative PCR, western blotting, liquid chromatography-mass spectrometry, and stereological analysis were employed to dissect the molecular, structural, and neurochemical phenotypes of the medial prefrontal cortex (mPFC) circuits in Df(h15q13)/+ mouse model. Transcriptomic profiling revealed enrichment for astrocyte-specific genes among differentially expressed genes, translated by a decrease in the number of glial fibrillary acidic protein positive cells in mPFC of Df(h15q13)/+ mice compared with wild-type mice. mPFC in Df(h15q13)/+ mice also showed a deficit of the inhibitory presynaptic marker GAD65, in addition to a reduction in dendritic arborization and spine density of pyramidal neurons from layers II/III. mPFC levels of GABA and glutamate neurotransmitters were not different between genotypes. Our results suggest that the 15q13.3 deletion modulates nonneuronal circuits in mPFC and confers molecular and morphometric alterations in the inhibitory and excitatory neurocircuits, respectively. These alterations potentially contribute to the phenotypes accompanied with the 15q13.3DS.
Mass Screening of Asymptomatic Persons for Severe Acute Respiratory Syndrome Coronavirus 2 Using Saliva
Authors: Yokota Isao , Shane Peter Y , Okada Kazufumi , Unoki Yoko , Yang Yichi , Inao Tasuku , Sakamaki Kentaro , Iwasaki Sumio , Hayasaka Kasumi , Sugita Junichi , Nishida Mutsumi , Fujisawa Shinichi , Teshima Takanori
Published: September 2020

Background

Coronavirus disease 2019 (COVID-19) has rapidly evolved to become a global pandemic, largely owing to the transmission of its causative virus through asymptomatic carriers. Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic people is an urgent priority for the prevention and containment of disease outbreaks in communities. However, few data are available in asymptomatic persons regarding the accuracy of polymerase chain reaction testing. In addition, although self-collected saliva samples have significant logistical advantages in mass screening, their utility as an alternative specimen in asymptomatic persons is yet to be determined.

Methods

We conducted a mass screening study to compare the utility of nucleic acid amplification, such as reverse-transcription polymerase chain reaction testing, using nasopharyngeal swab (NPS) and saliva samples from each individual in 2 cohorts of asymptomatic persons: the contact-tracing cohort and the airport quarantine cohort.

Results

In this mass screening study including 1924 individuals, the sensitivities of nucleic acid amplification testing with NPS and saliva specimens were 86% (90% credible interval, 77%–93%) and 92% (83%–97%), respectively, with specificities >99.9%. The true concordance probability between the NPS and saliva tests was estimated at 0.998 (90% credible interval, .996–.999) given the recent airport prevalence of 0.3%. In individuals testing positive, viral load was highly correlated between NPS and saliva specimens.

Conclusion

Both NPS and saliva specimens had high sensitivity and specificity. Self-collected saliva specimens are valuable for detecting SARS-CoV-2 in mass screening of asymptomatic persons.
Clinical Epidemiology of Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) in Japan: Report of the COVID-19 Registry Japan
Authors: Matsunaga Nobuaki , Hayakawa Kayoko , Terada Mari , Ohtsu Hiroshi , Asai Yusuke , Tsuzuki Shinya , Suzuki Setsuko , Toyoda Ako , Suzuki Kumiko , Endo Mio , Fujii Naoki , Suzuki Michiyo , Saito Sho , Uemura Yukari , Shibata Taro , Kondo Masashi , Izumi Kazuo , Terada-Hirashima Junko , Mikami Ayako , Sugiura Wataru , Ohmagari Norio
Published: September 2020

Background

There is limited understanding of the characteristics of patients with coronavirus disease 2019 (COVID-19) requiring hospitalization in Japan.

Methods

This study included 2638 cases enrolled from 227 healthcare facilities that participated in the COVID-19 Registry Japan (COVIREGI-JP). The inclusion criteria for enrollment of a case in COVIREGI-JP are both (1) a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test and (2) inpatient treatment at a healthcare facility.

Results

The median age of hospitalized patients with COVID-19 was 56 years (interquartile range [IQR], 40–71 years). More than half of cases were male (58.9%, 1542/2619). Nearly 60% of the cases had close contact to confirmed or suspected cases of COVID-19. The median duration of symptoms before admission was 7 days (IQR, 4–10 days). The most common comorbidities were hypertension (15%, 396/2638) and diabetes without complications (14.2%, 374/2638). The number of nonsevere cases (68.2%, n = 1798) was twice the number of severe cases (31.8%, n = 840) at admission. The respiratory support during hospitalization includes those who received no oxygen support (61.6%, 1623/2636) followed by those who received supplemental oxygen (29.9%, 788/2636) and invasive mechanical ventilation/extracorporeal membrane oxygenation (8.5%, 225/2636). Overall, 66.9% (1762/2634) of patients were discharged home, while 7.5% (197/2634) died.

Conclusions

We identified the clinical epidemiological features of COVID-19 in hospitalized patients in Japan. When compared with existing inpatient studies in other countries, these results demonstrated fewer comorbidities and a trend towards lower mortality.
Shiga Toxin–Producing Escherichia coli Transmission via Fecal Microbiota Transplant
Authors: Zellmer Caroline , Sater Mohamad R A , Huntley Miriam H , Osman Majdi , Olesen Scott W , Ramakrishna Bharat
Published: September 2020

Fecal microbiota transplantation (FMT) is recommended therapy for multiply recurrent Clostridioides difficile infection. We report adverse events in 7 patients who received FMT from a stool donor who was colonized with Shiga toxin–producing Escherichia coli (STEC). No patients died of FMT-transmitted STEC. Improved screening can likely avoid future transmission.
Trimethoprim-sulfamethoxazole Versus Azithromycin for the Treatment of Undifferentiated Febrile Illness in Nepal: A Double-blind, Randomized, Placebo-controlled Trial
Authors: Giri Abhishek , Karkey Abhilasha , Dangol Sabina , Arjyal Amit , Pokharel Sunil , Rijal Samita , Gajurel Damodar , Sharma Rabi , Lamsal Kamal , Shrestha Pradip , Prajapati Gayatri , Pathak Saruna , Shrestha Sita Ram , K.C Raj Kumar , Pandey Sujata , Thapa Abishkar , Shrestha Nistha , Thapa Raj Kumar , Poudyal Buddhi , Phuong Dung Nguyen Thi , Baker Stephen , Kestelyn Evelyne , Geskus Ronald , Thwaites Guy , Basnyat Buddha
Published: September 2020

Background

Azithromycin and trimethoprim-sulfamethoxazole (SXT) are widely used to treat undifferentiated febrile illness (UFI). We hypothesized that azithromycin is superior to SXT for UFI treatment, but the drugs are noninferior to each other for culture-confirmed enteric fever treatment.

Methods

We conducted a double-blind, randomized, placebo-controlled trial of azithromycin (20 mg/kg/day) or SXT (trimethoprim 10 mg/kg/day plus sulfamethoxazole 50 mg/kg/day) orally for 7 days for UFI treatment in Nepal. We enrolled patients >2 years and <65 years of age presenting to 2 Kathmandu hospitals with temperature ≥38.0°C for ≥4 days without localizing signs. The primary endpoint was fever clearance time (FCT); secondary endpoints were treatment failure and adverse events.

Results

From June 2016 to May 2019, we randomized 326 participants (163 in each arm); 87 (26.7%) had blood culture–confirmed enteric fever. In all participants, the median FCT was 2.7 days (95% confidence interval [CI], 2.6–3.3 days) in the SXT arm and 2.1 days (95% CI, 1.6–3.2 days) in the azithromycin arm (hazard ratio [HR], 1.25 [95% CI, .99–1.58]; P = .059). The HR of treatment failures by 28 days between azithromycin and SXT was 0.62 (95% CI, .37–1.05; P = .073). Planned subgroup analysis showed that azithromycin resulted in faster FCT in those with sterile blood cultures and fewer relapses in culture-confirmed enteric fever. Nausea, vomiting, constipation, and headache were more common in the SXT arm.

Conclusions

Despite similar FCT and treatment failure in the 2 arms, significantly fewer complications and relapses make azithromycin a better choice for empirical treatment of UFI in Nepal.

Clinical Trials Registration

NCT02773407.