bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical constants of polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As determined by variable-angle spectroscopic ellipsometry
Authors: Quispe D. , Eng B. , Kim M. , Onno A. L. , Coppa B. J. , Yu Z. J. , Lee M. L. , Holman Z. C.
Published: August 2023

The optical constants of single-crystal AlxGa1−xP and AlxGa1−xAs have been widely studied at various Al compositions but have not yet been thoroughly investigated as polycrystalline materials. Using variable-angle spectroscopic ellipsometry, we estimate and analyze the optical constants of polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As that were non-epitaxially deposited at deposition temperatures of either 250 or 420 °C, and with various dopant species, dopant concentrations, and V/III flux ratios. For wavelengths of 350–400 nm, decreasing the V/III ratio increases the refractive index of Be-doped polycrystalline Al0.25Ga0.75P. For wavelengths >500 nm, as the targeted Be dopant concentration increases for polycrystalline Al0.25Ga0.75P, the amount the extinction coefficient increases and the indirect bandgap decreases depends on the V/III ratio. Furthermore, Si-doped polycrystalline Al0.25Ga0.75P has significantly smaller extinction coefficient values than when it is Be-doped, for the same V/III ratio and targeted doping concentration, at wavelengths >500 nm. Based on our findings, we hypothesize that the dopant species, dopant concentration, and the V/III ratio dictate various types of defect concentrations, which then affect the optical constants and indirect bandgap of polycrystalline Al0.25Ga0.75P. Additionally, for wavelengths >500 nm, we find that polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As have the lowest extinction coefficient values when deposited at 420 °C, as opposed to 250 °C. Thus, we hypothesize that the deposition temperature is the most significant factor in dictating the optical constants of these polycrystalline III-Vs. Ultimately, this work demonstrates alternative methods to tune the optical constants of polycrystalline Al0.25Ga0.75P and Al0.9Ga0.1As, as opposed to tuning the Al composition.
Coupling of orbital and spin polarizations to interatomic hopping in a helical atomic chain
Authors: Yatabe Yuya , Akera Hiroshi
Published: August 2023

Electron transport through a variety of helical structures has been shown to exhibit high-efficiency spin filtering, which is called chirality-induced spin selectivity (CISS). In this paper, we consider a helical chain of atomic p orbitals, which has been employed as a model in exploring the mechanism of CISS in previous theories, and show that the interatomic hopping along the helical chain induces an effective magnetic field (EMF) acting on the atomic orbital angular momentum (OAM). In chains where the curvature and torsion of the helix are small, we find that the EMF on the binormal component of the atomic OAM is created by the curvature, while that on the tangential component is produced by the torsion. We show that such coupling of the atomic OAM and the interatomic hopping leads to current-induced orbital and spin polarizations. We expect that the present coupling, which is expressed locally, can be used to estimate orbital and spin polarizations locally induced in molecules and solids.
Isotropic atomic layer etching of GaN using SF6 plasma and Al(CH3)3
Authors: Chittock Nicholas J. , Shu Yi , Elliott Simon D. , Knoops Harm C. M. , Kessels W. M. M. (Erwin). , Mackus Adriaan J. M.
Published: August 2023

GaN is an enabling material for light emitting diodes, advanced radio frequency, and power semiconductor devices. However, fabrication of GaN devices often relies on harsh etch processes, which can leave an etch damage layer, limiting final device performance. In this work, an isotropic atomic layer etching (ALE) process involving SF6 plasma and trimethylaluminium [Al(CH3)3] is presented for the controlled etching of GaN, which reduces oxygen and carbon contamination while smoothing the surface. The ALE chemistry was first examined with density functional theory. A comparison between proposed thermal and plasma-driven reactions is made by implementing Natarajan–Elliott analysis, highlighting that the plasma process is a good candidate for GaN ALE. Saturation was experimentally confirmed for both ALE half-cycles at 150 and 300 °C, with etch rates of 0.31 ± 0.01 and 0.40 ± 0.02 nm/cycle, respectively. Analysis of the films post-ALE shows that the RMS roughness of the films decreases from 2.6 ± 0.1 to 1.9 ± 0.1 nm after 25 nm of etching at 300 °C, in agreement with a previously developed curvature-dependent smoothing model. Taken together, this ALE process enables accurate GaN thickness tuning, surface cleaning, and surface smoothing, allowing for further development of GaN devices.
Prediction of hemiwicking dynamics in micropillar arrays
Authors: Zhang Shiyu , Wang Ruisong , Adera Solomon , Guo Jiahui , Wang Yida , Antao Dion S.
Published: August 2023

Dynamic hemiwicking behavior is observable in both nature and a wide range of industrial applications ranging from biomedical devices to thermal management. We present a semi-analytical modeling framework (without empirical fitting coefficients) to predict transient capillary-driven hemiwicking behavior of a liquid through a nano/microstructured surface, specifically a micropillar array. In our model framework, the liquid domain is discretized into micropillar unit cells to enable the time marching of the hemiwicking front. A simplified linear pressure drop is assumed along the hemiwicking length such that the local meniscus curvature, contact angle, and effective liquid height are determined at each time step in our transient model. This semi-analytical model is validated with experimental data from our own experiments and from published literature for different fluids. Our model predicts hemiwicking dynamics with <20% error over a broad range of micropillar geometries with height-to-pitch ratio ranging between ≈0.34 and 6.7 and diameter-to-pitch ratio in the range of ≈0.25–0.7 and without any fitting parameters. For lower diameter-to-pitch ratio data points related to sparse micropillar array arrangements, we suggest modifications to the semi-analytical model. This work sheds light on complex and dynamic solid–liquid–vapor interfacial interactions which could serve as a guide for the design of textured surfaces for wicking enhancement in multi-phase thermal and mass transport technologies and applications.
Substrate effects in hysteresis of microscale Ni–Mn–Sn Heusler alloy films
Authors: Zhang Yijia , Zhao Dexin , Lago Juan C. , Xie Kelvin , Shamberger Patrick J.
Published: August 2023

During martensitic phase transformations in thin films, substrates impact hysteresis by introducing an additional interface, which can inhibit martensite/austenite interface motion. In order to reduce hysteresis, we examine 2.9–14.5 μm thick Ni–Mn–Sn films, which in some cases have been delaminated from the substrates before or after annealing. We compare thermal hysteresis and defect densities at the interface. Delaminating films prior to annealing decreases hysteresis, whereas delaminating films after annealing does not significantly impact hysteresis. Substrate effects are attributed to the thermal expansion mismatch between the film and substrate, resulting in the formation of dislocations at the interface and, consequentially, an increase in frictional resistance to martensite/austenite interface motion.
Room temperature two-dimensional ferromagnetic Ni-doped Fe5GeTe2 with tunable Tc for enhanced oxygen evolution reaction
Authors: Wang Bochong , Li Yongbing , Li Xiang , Mu Congpu , Xiang Jianyong , Yuan Shijun , Nie Anmin , Zhai Kun , Xue Tianyu , Wen Fusheng , Liu Zhongyuan
Published: August 2023

Improving the Curie temperature and catalytic performance of two-dimensional magnetic materials through elemental doping is a feasible strategy. In this study, Ni-doped (Fe1−xNix)5GeTe2 (0 ≤ x ≤ 0.3) single crystals were grown via chemical vapor transport method and the amount of Ni doping could be precisely controlled. As the amount of Ni doping increases, the long-range ferromagnetic ordering temperature increased, and (Fe0.7Ni0.3)5GeTe2 exhibited the highest Curie temperature Tc = 492.73 K. The improvement of Tc can be attributed to the occupancy of the Fe1 site by Ni atoms. The oxygen evolution reaction (OER) activities of liquid phase exfoliated (Fe1−xNix)5GeTe2 nanoflakes were enhanced by doping Ni atoms, and the overpotential decrease to 464 mV at 10 mA/cm2 with a small Tafel slope of 41 mV/dec for the (Fe0.9Ni0.1)5GeTe2 nanoflakes. Based on the density functional theory calculations, when half of the Fe1 sites were replaced by Ni atoms, the number of enhanced OER active sites (Fe1-Te sites) reached maximum, and then, (Fe0.9Ni0.1)5GeTe2 exhibited the best catalytic performance. The experimental and theoretical calculation results indicate that replacing Fe1 site with Ni in two-dimensional magnetic Fe5GeTe2 can effectively increase the Curie temperature and enhance OER activity.
Development of Sb2Se3 alloys by Ti-doping with ultralow resistance drift and improved microstructure for nonvolatile memory applications
Authors: Wu Tong , Wang Guoxiang , Lotnyk Andriy , Zhu Jinyi , Jiao Yucheng , Shen Xiang
Published: August 2023

The Sb2Se3 and Ti-doped Sb2Se3 phase change thin films were prepared by magnetron sputtering. The relationship between resistance drift and crystallization behavior of Sb2Se3 and Ti-doped Sb2Se3 thin films were thoroughly investigated. The results revealed that when Ti-doping concentration reaches 5.4 at. %, Ti5.4(Sb2Se3)95.4 thin film exhibited a high thermal stability with crystallization temperature of 225 °C and 10-year data retention temperature of 129.5 °C. This benefits to lower resistance drift coefficient from 0.067 for Sb2Se3 to 0.002 for Ti5.4(Sb2Se3)95.4. Further microstructural analysis revealed the suppression of large grain growth in Ti-doped Sb2Se3 thin films, while the formation of Ti–Sb and Ti–Se bonds being responsible for enhanced stability of the amorphous Ti-doped thin films. Moreover, the Ti doping promoted one-dimensional growth-dominated crystallization mechanism of the studied alloys, leading to the reduced nucleation index compared to Sb2Se3. The present study sheds valuable light on the effectively reducing nucleation randomness in chalcogenide-based phase-change materials.
Optical-scanning evanescent sensor for high-speed broadband photoacoustic microscopy
Authors: Yang Yifan , Yang Fan , Song Wei , Yuan Xiaocong
Published: August 2023

Photoacoustic microscopy with high spatial resolution and fast imaging acquisition allows observing dynamic processes of optical absorption-based microanatomic structures in three dimensions. An evanescent sensor accesses ultrasonic detection with high sensitivity and broad bandwidth while suffering from limited field of view (FOV), thus compromising the photoacoustic imaging acquisition rate. Here, we develop an optical-scanning evanescent sensor by fast deflection of the interrogation light along the interface of prism and water using a one-dimensional galvanometer, demonstrating excellent detection sensitivity of ∼132 Pa with a broadband frequency response of >140-MHz at an enlarged FOV of ∼2.90 × 0.19 mm2. Incorporating the optical-scanning evanescent sensor in photoacoustic microscopy, a volumetric image (∼3.0 × 0.25 × 1.0 mm3) with micrometer-scale spatial resolution is acquired within ∼2.5 s by synergistically scanning both photoacoustic illumination laser and sensor's interrogation light. High-speed imaging of flowing microparticles within a capillary tube offers the visualizations of the traveling processes in three dimensions. Potentially, the optical-scanning evanescent sensor allows photoacoustic microscopy accommodating to dynamic imaging at cellular level such as in vivo flow cytometry of circulating tumor cells.
Unraveling instabilities and mixing behavior in two-layered flows: A quest for the optimum viscosity ratio
Authors: Banga Priyanka , Maharana Surya Narayan , Mishra Manoranjan
Published: August 2023

A two-layer miscible displacement of density-matched but viscosity-contrasted fluids through a channel is numerically investigated in a nonlinear regime. The flow is governed by Navier–Stokes equations, which are coupled to a convection-diffusion equation via viscosity dependent concentration. Instabilities in the form of roll-ups or ligament waves are observed when a less viscous fluid is sheared over a more viscous fluid. Through interfacial length calculations, we demonstrate that the temporal evolution of the interface can be divided into three regimes: the initial diffusion-dominated regime, the intermediate convection-dominated regime, and the final diffusion-dominated regime. With the unstable roll-up growth only in a convection-dominated regime, the growth of instability delays at later times in diffusion dominated regime. Moreover, onset time ton vs R plots for each Reynolds number (Re), Péclet number (Pe), initial interface location (h), and thickness of initial mixing zone (q) depict that the instability originates early for intermediate viscosity ratios (R) than larger R. In contrast to earlier studies in the linear regime, we showed that if the viscosity ratio between two fluids is very large or small, the instability doesn't trigger in the nonlinear regime. The analysis of the concentration's global variance-based degree of mixing allows us to find optimum parameters for maximum mixing. We show that the optimal mixing is obtained at an intermediate value of R (optimum R). Furthermore, the degree of mixing is found to increase for increasing Re and decreasing Pe.
Thermally developing combined electroosmotic and pressure-driven flow of Phan–Thien–Tanner fluids in a microchannel
Authors: Kumbalpuri Tripti , Sarkar Sandip
Published: August 2023

We present semi-analytical solutions for the hydrodynamically developed and thermally developing flow of a non-Newtonian fluid through an isothermal rectangular microchannel. The fluid motion is actuated by the combined consequences of the electroosmotic and pressure-gradient forces. For the rheological behavior of the non-Newtonian fluid, we have used the simplified Phan–Thien–Tanner viscoelastic model. Going beyond the Debye Hückel linearization approximation, we have used the full-scale solution for the electrical double-layer potential equation to obtain the exact analytical solutions for the velocity, flow rate, and shear rate parameters. In contrast, the temperature distribution and heat transfer for the thermally developing flow have been obtained by solving the energy equation numerically considering the effects of volumetric heat generation due to Joule heating and viscous dissipation. We find that a larger value of the viscoelastic set ε̃Wĩk2 contributes toward the net gain in flow rate. Both the normal and shear stress increase for increasing ε̃Wĩk2, while the shear viscosity reduces with a degree of surface charging. The average shear viscosity reduces with the degree of surface charging and at higher ε̃Wĩk2 values. The heat transfer is enhanced for augmenting ε̃Wĩk2, although the thermal entrance region gets contracted for a pure electroosmotic flow at higher Peclet numbers. Our study reveals that the heat transfer rate can be amplified by effectively modulating the degree of surface charging and ε̃Wĩk2. We have also carried out an entropy generation analysis, which shows the dominance of heat transfer irreversibility over fluid friction irreversibility. We believe that the present research will offer essential approaches for designing advanced energy-efficient microchannels appropriate to modern industrial applications using viscoelastic fluids.
Polarization conversion at multiple angles in the terahertz regime via a metasurface with two crossed L-shaped elements
Authors: Bai Yuanyuan , Ouyang Chunmei , Yao Zhibo , Liu Shilei , Li Yanfeng , Liu Liyuan , Gu Jianqiang , Han Jiaguang , Zhang Weili
Published: August 2023

Although remarkable advances have been made over the past decades, more functional devices suitable for practical systems are needed to further facilitate the development and application of terahertz technology. Among them, polarization devices are essential in terahertz systems. In this work, a metasurface with a multi-angle polarization conversion function is proposed. The device is composed of a top metal structure layer, a dielectric spacer, and a bottom metal film. The unit cell in the metal structure layer consists of two L-shaped elements which are symmetric about the −45° axis and rotated clockwise and counterclockwise around the center, respectively. Cross-polarization conversion can be achieved when the metal structure is in its original position. When the structure is rotated counterclockwise at a certain angle around the center, oblique polarization conversion can be realized within the same frequency band. If we keep rotating the structure, more polarization conversion angles can be achieved. Compared with recent reports, the structure proposed here is more flexible in polarization conversion and more suitable for practical applications and has great potential in the terahertz field.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: August 2023

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials, which supersede earlier data or suggest new research applications.
Phosphorylation of RhoGDI1, a Rho GDP dissociation inhibitor, regulates root hair development in
Arabidopsis
under salt stress
Authors: Liu Xiangning , Yu Xiang , Shi Yue , Ma Liang , Fu Ying , Guo Yan
Published: August 2023

To ensure optimal growth, plants actively regulate their growth and development based on environmental changes. Among these, salt stress significantly influences growth and yield. In this study, we demonstrate that the growth of root hairs of salt-stressed
Arabidopsis thaliana
seedlings is regulated by the SALT OVERLY SENSITIVE 2 (SOS2)–GUANOSINE NUCLEOTIDE DIPHOSPHATE DISSOCIATION INHIBITOR 1 (RhoGDI1)–Rho GTPASE OF PLANTS 2 (ROP2) module. We show here that the kinase SOS2 is activated by salt stress and subsequently phosphorylates RhoGDI1, a root hair regulator, thereby decreasing its stability. This change in RhoGDI1 abundance resulted in a fine-tuning of polar localization of ROP2 and root hair initiation followed by polar growth, demonstrating how SOS2-regulated root hair development is critical for plant growth under salt stress. Our results reveal how a tissue-specific response to salt stress balances the relationship of salt resistance and basic growth.
Electric field–induced magnetochiral dichroism in a ferroaxial crystal
Authors: Hayashida Takeshi , Kimura Kenta , Kimura Tsuyoshi
Published: August 2023

In a chiral medium, any mirror symmetries are broken, which induces unique physical properties represented by natural optical rotation. When electromagnetic waves propagate through a chiral medium placed in a magnetic field, the refractive index, or equivalently, the absorption encountered by the electromagnetic waves differs depending on whether it travels parallel or antiparallel to the magnetic field. Such a phenomenon is known as magnetochiral dichroism (MChD), which is the characteristic interplay between chirality and magnetism. Similar to chirality, the so-called ferroaxial order, an emergent ferroic state of crystalline materials, is also characterized by mirror symmetry breaking. In contrast to chiral materials, however, the mirror symmetry perpendicular to the crystalline principal axis is allowed in ferroaxial materials. In other words, chirality and thus phenomena unique to chirality can be induced by breaking the remaining mirror symmetry by applying an electric field. Here, we show electric control of chirality and resulting electric field–induced MChD (
E
-MChD) of the short-wavelength infrared region in a ferroaxial crystal, NiTiO
3
. We performed spectroscopy measurements of
E
-MChD by taking a difference of absorption coefficients obtained with and without electric and magnetic fields. As a result,
E
-MChD was observed around the excitation energy corresponding to Ni
2+
d-d
magnetic-dipole transitions. The result is nicely explained by adopting the theory of MChD concerning the pseudo-Stark splitting of the energy state. Ferroaxial materials therefore provide platforms to achieve electric control of chirality-related phenomena.
A human monoclonal antibody combination rescues nonhuman primates from advanced disease caused by the major lineages of Lassa virus
Authors: Cross Robert W. , Heinrich Megan L. , Fenton Karla A. , Borisevich Viktoriya , Agans Krystle N. , Prasad Abhishek N. , Woolsey Courtney , Deer Daniel J. , Dobias Natalie S. , Rowland Megan M. , Lathigra Raju , Borrega Rodrigo , Geisbert Joan B. , Garry Robert F. , Branco Luis M. , Geisbert Thomas W.
Published: August 2023

There are no approved treatments for Lassa fever (LF), which is responsible for thousands of deaths each year in West Africa. A major challenge in developing effective medical countermeasures against LF is the high diversity of circulating Lassa virus (LASV) strains with four recognized lineages and four proposed lineages. The recent resurgence of LASV in Nigeria caused by genetically distinct strains underscores this concern. Two LASV lineages (II and III) are dominant in Nigeria. Here, we show that combinations of two or three pan-lineage neutralizing human monoclonal antibodies (8.9F, 12.1F, 37.D) known as Arevirumab-2 or Arevirumab-3 can protect up to 100% of cynomolgus macaques against challenge with both lineage II and III LASV isolates when treatment is initiated at advanced stages of disease on day 8 after LASV exposure. This work demonstrates that it may be possible to develop postexposure interventions that can broadly protect against most strains of LASV.
Orange/far-red hybrid voltage indicators with reduced phototoxicity enable reliable long-term imaging in neurons and cardiomyocytes
Authors: Liu Shuzhang , Ling Jing , Chen Peng , Cao Chang , Peng Luxin , Zhang Yuan , Ji Guangshen , Guo Yingna , Chen Peng R. , Zou Peng , Chen Zhixing
Published: August 2023

Hybrid voltage indicators (HVIs) are chemogenetic sensors that combines the superior photophysical properties of organic dyes and the genetic targetability of protein sensors to report transient membrane voltage changes. They exhibit boosted sensitivity in excitable cells such as neurons and cardiomyocytes. However, the voltage signals recorded during long-term imaging are severely diminished or distorted due to phototoxicity and photobleaching issues. To capture stable electrophysiological activities over a long time, we employ cyanine dyes conjugated with a cyclooctatetraene (COT) molecule as the fluorescence reporter of HVI. The resulting orange-emitting HVI–COT–Cy3 enables high-fidelity voltage imaging for up to 30 min in cultured primary neurons with a sensitivity of ~ −30% ΔF/F
0
per action potential (AP). It also maximally preserves the signal of individual APs in cardiomyocytes. The far-red-emitting HVI–COT–Cy5 allows two-color voltage/calcium imaging with GCaMP6s in neurons and cardiomyocytes for 15 min. We leverage the HVI–COT series with reduced phototoxicity and photobleaching to evaluate the impact of drug candidates on the electrophysiology of excitable cells.
The apicoplast is important for the viability and persistence of
Toxoplasma gondii
bradyzoites
Authors: Sanchez Syrian G. , Bassot Emilie , Cerutti Aude , Mai Nguyen Hoa , Aïda Amel , Blanchard Nicolas , Besteiro Sébastien
Published: August 2023

Toxoplasma gondii
is responsible for toxoplasmosis, a disease that can be serious when contracted during pregnancy, but can also be a threat for immunocompromised individuals. Acute infection is associated with the tachyzoite form that spreads rapidly within the host. However, under stress conditions, some parasites can differentiate into cyst-forming bradyzoites, residing mainly in the central nervous system, retina and muscle. Because this latent form of the parasite is resistant to all currently available treatments, and is central to persistence and transmission of the parasite, specific therapeutic strategies targeting this developmental stage need to be found.
T. gondii
contains a plastid of endosymbiotic origin called the apicoplast, which is an appealing drug target because it is essential for tachyzoite viability and contains several key metabolic pathways that are largely absent from the mammalian host. Its function in bradyzoites, however, is unknown. Our objective was thus to study the contribution of the apicoplast to the viability and persistence of bradyzoites during chronic toxoplasmosis. We have used complementary strategies based on stage-specific promoters to generate conditional bradyzoite mutants of essential apicoplast genes. Our results show that specifically targeting the apicoplast in both in vitro or in vivo-differentiated bradyzoites leads to a loss of long-term bradyzoite viability, highlighting the importance of this organelle for this developmental stage. This validates the apicoplast as a potential area to look for therapeutic targets in bradyzoites, with the aim to interfere with this currently incurable parasite stage.
On the L1-acquisition of the pragmatics of discourse like
Authors: Schweinberger Martin
Published: August 2023

This study analyzes the L1-acquisition of discourse like and its pragmatic functions in American
English based on the Home-School Study of Language and Literacy Development component of the Child
Language Data Exchange System (CHILDES). The data show that discourse like is already present in the
speech of 3- and 4-year-old children and that even very young children employ like to perform distinct pragmatic
functions with specifying uses being dominant until age 8;5. The analysis also shows a notable increase in discourse
like as children mature, mainly driven by an increase in attention-directing like, the
dominant function of discourse like among children older than 8;5. Conditional inference trees show that the use
of discourse like by children is affected by a child’s age, the situation type and the frequency of discourse
like in caregivers’ input. Children younger than 7;10 use discourse like only rarely in
formal contexts as well as in informal contexts if their caregivers do not use discourse like frequently.
However, children use discourse like substantially more if they are older than 7;10 or, in informal contexts,
when their caregivers use discourse like frequently. The changes in frequency and the functional shifts in the
use of like around the ages of 7 to 9 is interpreted to show that peers become more important as linguistic role
models when children enter school. The results thus substantiate research which suggests that the pragmatic and social meanings of
discourse markers are learned alongside linguistic constraints rather than after the form has been acquired.
Empiricism against imperialism
Authors: Bakker Peter
Published: August 2023

Large scale typological studies have been criticized for being unscientific, biased, methodologically unsound and as perpetrating neocolonial attitudes.Meakins (2022)echoes these views in her first JPCL column. The conclusions ofallstudies using large typological datasets, however, point in the direction that creoles do have structural properties that distinguish them from their lexifiers and the languages of the world, including a dozen not mentioned in Meakins’ column. Opponents use data that are a factor of thousand less extensive, yet apparently more credible. Creoles developed in adverse circumstances, and the flexibility of human genius led to new structural properties, apparently shared across the world. The opposite view, that creoles are continuations of their lexifiers, runs the risk of justifying colonialism, as if forced deportation, blackbirding, slavery, imperialism and colonialism could not have had catastrophic consequences for the continuation of languages. Devastating sociohistorical circumstances led to the creation of new societies, and human ingenuity created their fully-fledged natural languages.
Semiotics of a Covid landscape
Authors: Modan Gabriella , Schaller Susanna
Published: August 2023

This paper brings together urban planning and linguistic perspectives to examine the semiotic landscape of a
Washington, DC ‘streatery’ in the context of the intersecting public health- and place-based economic crises unleashed by the
Covid-19 pandemic. Drawing from Garay-Huamán and Irazábal-Zurita’s (2021) work on
neoliberal Social Structures of Accumulation (SSA), we examine how different layers of Adams Morgan’s emergent
Covid landscape are rooted in the dynamics of capitalist accumulation through urban placemaking strategies. We focus on signs put
up by the Business Improvement District (BID) that explain the public health regulations applicable to the area through discourse
that playfully encourages people to social distance and wear masks. These signs utilize three linguistic or semiotic discourses:
hygiene, humor and play, and anti-Trump politics. The signs serve as a bona fide effort to both halt the spread of the coronavirus
and take a political stance. At the same time as the signs promote public health, their commodified aestheticization of hygiene
and politics also serves commercial interests.
Native and foreign language orthotactic probability and neighborhood density in word learning
Authors: Ring Josh , Leoné Frank , Dijkstra Ton
Published: August 2023

Laboratory studies on word learning in a foreign language (L2) have identified several variables involved in the learning process, key amongst them the orthotactic probability and neighborhood density of new words relative to learners’ native (L1) lexicons. More recently, learners’ sensitivity to orthotactic probability and neighborhood density relative to their developing L2 lexicons has come into focus. Past studies on word learning have largely focused on early stages of learning, in controlled studies spanning hours or days. Few studies have considered large corpora of ‘real-life’ learning data, spanning several weeks. In this study, we validate past findings outside of controlled laboratory conditions, by analyzing a dataset collected from Duolingo (Settles et al., 2018), a popular language learning app. Effects of orthotactic probability and neighborhood density observed in controlled studies persist under uncontrolled, big-data conditions for learners of Spanish, but not French. As learning progresses, we observe a previously unreported reversal of the effects of L1 orthotactic probability and neighborhood density, challenging theoretical models of word learning. Finally, we confirm the importance of orthotactic probability and neighborhood density relative to learners’ developing L2 Spanish lexicons, lending support to theories which posit that the same processes underly both L1 and L2 acquisition.
The emotional value of Polish and English subtitles
Authors: Stanisławska Agata , Korpal Paweł
Published: August 2023

Although research on the role of emotion in audiovisual translation and audio description has gained some ground in recent years, the emotional reception of subtitles as an AVT mode has been under researched. To address this empirical gap, this paper presents the results of a study on the emotional rating of English and Polish subtitles to a selection of animated films. Expressions from Polish and English subtitled versions of the same films were collected, and 100 participants (native speakers of Polish and English) were asked to rate them in terms of emotional valence and arousal evoked. While the main effect of utterance type (negatively valenced, neutral, positively valenced) was observed, there was no effect of language, suggesting that the subtitle excerpts elicited similar responses in both languages.
Microsatellite analysis of the Queensland fruit fly Bactrocera tryoni (Diptera: Tephritidae) indicates spatial structuring: implications for population control
Authors: Yu H. , Frommer M. , Robson M.K. , Meats A.W. , Shearman D.C.A. , Sved J.A.
Published: August 2023

The population structure of a tephritid pest species, the Queensland fruit fly Bactrocera tryoni (Froggatt), has been analysed over a five year period (1994–1998), using six microsatellites. Adult fly samples were collected to cover most regions of eastern and central Australia where the flies are regularly found. Tests for heterogeneity indicated that flies within geographically defined regions were homogeneous. The samples were allocated into five regions, including one very large region, Queensland, which encompasses that portion of the fly‘s range where breeding can occur year-round. With one exception, the collections from different regions were homogeneous between years, showing a fairly static distribution of the species. However, differences between regions were highly significant. The one case of a change in frequency between years indicated a gradual replacement of flies in a marginal region by flies from the main part of the range. The finding of stability in the distribution of a highly mobile insect is of interest, potentially also for other species which have expanded beyond their native range. It is argued that a contributing reason for this stability may be adaptation to different climatic regimes, and that strategies for control based on this hypothesis afford a reasonable chance of success.
Spatial and temporal distribution of tsetse fly trap catches at Nguruman, southwest Kenya
Authors: Odulaja A. , Baumgärtner J. , Mihok S. , Abu-Zinid I.M.
Published: August 2023

Spatial and temporal dynamics of rapidly growing populations of tsetse flies at Nguruman, southwest Kenya during 1993–1995, were investigated, following six years of intensive population suppression with traps over a c. 100 km2area. The two tsetse species present were randomly distributed in the short rainy season, but were aggregated in the dry and long rainy seasons. Maximum temperature was the dominant weather factor associated with the degree of aggregation. Trends in catches at 20 fixed sites along an 18 km north–south axis were weakly correlated between locations, possibly representing population sub-structuring. In particular, trends in population change were poorly correlated between the area with a long history of trapping suppression in the south and the area with a more recent history of suppression in the north. On a micro-geographic scale, correlations among paired trap catches were clearly related to geographical proximity for Glossina pallidipes Austen (r2 = 0.55); whereas this relationship was quite weak for Glossina longipennis Corti (r2 = 0.12). Positive correlations among trap catches were significant for sites separated by less than c. 3.8 km (G. pallidipes) or 4.8 km (G. longipennis). These results suggest the existence of different population substructures in the two species on a relatively small geographic scale.
Development, survival and reproduction of black citrus aphid, Toxoptera aurantii (Hemiptera: Aphididae), as a function of temperature
Authors: Wang J.J. , Tsai J.H.
Published: August 2023

The development, survival, and reproduction of the black citrus aphid Toxoptera aurantii (Boyer de Fonscolombe) were evaluated at ten constant temperatures (4, 7, 10, 15, 20, 25, 28, 30, 32 and 35°C). Development was limited at 4 and 35°C. Between 7 and 32°C, developmental periods of immature stages varied from 44.2 days at 7°C to 5.3 days at 28°C. Overall immature development required 129.9 degree-days above 3.8°C. The upper temperature thresholds of 32.3, 28.6, 29.3, 27.2, and 28.6°C were determined from a non-linear biophysical model for the development of instars 1–4 and overall immature stages, respectively. Immature survivorship varied from 82.1 to 97.7% within the temperature range of 10–30°C. However, immature survivorship was reduced to 26.3%at 7°C and 33.1% at 32°C. Mean adult longevity was the longest (44.2 days) at 15°C and the shortest (6.2 days) at 32°C. The predicted upper temperature limit for adult survivorship was at 32.3°C. Total nymph production increased from 16.3 nymphs per female at 10°C to 58.7 nymphs per female at 20°C, declining to 6.1 nymphs per female at 32°C. The estimation of lower and upper temperature limits for reproduction was at 8.2 and 32.5°C, respectively. The population reared at 28°C had the highest intrinsic rate of increase (0.394), the shortest population doubling time (1.8 days), and shortest mean generation time (9.5 days) compared with the populations reared at six other temperatures. The population reared at 20°C had the highest net reproductive rate (54.6). The theoretical lower and upper temperature limits for population development, survival and reproduction were estimated at 9.4 and 30.4°C, respectively. The biology of T. aurantiiwas also compared with three other citrus aphid species.
Ecological and genetic aspects of grape phylloxera Daktulosphaira vitifoliae (Hemiptera: Phylloxeridae) performance on rootstock hosts
Authors: Forneck A. , Walker M.A. , Blaich R.
Published: August 2023

Performance and genetic variability of clonal lineages derived from one Californian and one German population of grape phylloxera, Daktulosphaira vitifoliae Fitch were studied on their natal grape rootstock host and on three novel hosts over four generations in an aseptic dual culture system. The ability of D. vitifoliae to adapt to new hosts was measured by changes in fitness (rm) over four generations. The performance of a given clonal lineage changed over successive generations, depending upon the host plant and the phylloxera group. Analysis of amplified fragment length polymorphism–polymerase chain reaction (AFLP–PCR) banding patterns from 40 individual parthenogenetic D. vitifoliae revealed equal levels of genetic variation both among the four clonal lineages analysed and within the different generations of one lineage. Analysis of molecular variance (AMOVA) showed no significant differences between the D. vitifoliae lineages reared on different host plants, nor was a correlation between host performance and genotype found.
Development and reproductive capacity of Thrips hawaiiensis (Thysanoptera: Thripidae) and its potential as a major pest
Authors: Murai T.
Published: August 2023

The effect of constant temperature on development, reproduction and population growth of Thrips hawaiiensis (Morgan) reared on a diet of pollen and honey solution was studied. Although hatchability and survival rates from egg hatch to adult were higher than 79% between 15 and 25°C, they were lower than 55% at 10 and 30°C. Developmental rates increased linearly as rearing temperature increased. It was estimated that 153.8 degree-days, above a lower threshold temperature of 10.4°C, were required to complete development from egg to adult oviposition. According to these figures, between 11 and 18 generations of T. hawaiiensis could have developed annually under outdoor conditions in western Japan, between 1990 and 1999. Mean adult longevity decreased with increasing temperature, from a maximum of 102.7 days at 15°C to a minimum of 27.8 days at 25°C. The mean fecundity on pollen and honey solution was highest at 20°C with 536.9 eggs per female. The highest intrinsic rate of natural increase (rm) 0.208 was observed at 25°C.
The changing distribution of two riverine tsetse flies over 15 years in an increasingly cultivated area of Burkina Faso
Authors: de La Rocque S. , Augusseau X. , Guillobez S. , Michel V. , De Wispelaere G. , Bauer B. , Cuisance D.
Published: August 2023

Changes in the distribution of two riverine tsetse flies, Glossina tachinoides Westwood and Glossina palpalis gambiensis Vanderplank are described in an agro-pastoral area of Burkina Faso subject to increasing human population pressure and land use change. Two similar entomological surveys (one trap every 100 m, 120 km of river) were conducted in 1981 and 1996. Changes in tsetse distribution were compared to land use changes through high resolution remote sensing imagery (LANDSAT, SPOT). There was a close relationship between proximity of crops relative to riverine forest and the density of Glossina. Where fields encroached on riverine vegetation, tsetse populations declined. Where the geomorphological structure was not well suited to agricultural activity, riverine vegetation and tsetse fly populations were relatively unaffected, even with intense agricultural activity nearby. In contrast, increased human activity and higher cattle densities in the surrounding savannah areas were associated with increased tsetse numbers. The results demonstrated a wide diversity of tsetse distribution and habitat within a few kilometres in an agro-pastoral landscape in West Africa.
Sex separation of tsetse fly pupae using near-infrared spectroscopy
Authors: Dowell F.E. , Parker A.G. , Benedict M.Q. , Robinson A.S. , Broce A.B. , Wirtz R.A.
Published: August 2023

Implementation of the sterile insect technique for tsetse (Glossina spp.) requires that only sterile male insects be released; thus, at some stage of the fly production process the females have to be removed. A further constraint in the use of the sterile insect technique for tsetse is that the females are needed for colony production and hence, a non-destructive method of sex separation is required. In most tsetse sterile insect technique programmes thus far, females have been eliminated from the released material by hand-separation of chilled adults. Using near-infrared (NIR) spectroscopy, significant differences have been found between the spectra for the pupae of male and female G. pallidipes Austen. Significantly, the differences appear to be maximized 4–5 days before emergence of the adults. Tsetse fly pupae up to five days before emergence can be sexed with accuracies that generally range from 80 to 100%. This system, when refined, will enable effective separation of male and female pupae to be carried out, with emerged females being returned to the colony and males being irradiated and released. If separation can be achieved five days before emergence, this will also enable irradiated male pupae to be shipped to other destinations as required. Other Diptera were evaluated using this system but had lower classification accuracies of 50–74%. This may be due to the difference in reproductive physiology between these different fly groups.
Enemies in low places – insects avoid winter mortality and egg parasitism by modulating oviposition height
Authors: Obermaier E. , Heisswolf A. , Randlkofer B. , Meiners T.
Published: August 2023

Oviposition site selection in insects is essential in terms of low egg mortality, high offspring survival and therefore a high reproductive output. Although oviposition height could be a crucial factor for the fitness of overwintering eggs, it has rarely been investigated. In this study the oviposition height of a polyphagous leaf beetle, Galeruca tanaceti Linnaeus in different habitats and at different times of the season was examined and its effect on egg clutch mortality was recorded. The leaf beetle occurs as an occasional pest on several agricultural plants. It deposits its eggs within herbaceous vegetation in autumn. Eggs are exposed to numerous biotic and abiotic mortality factors summarized as egg parasitism and winter mortality. Oviposition height of the leaf beetle was not uniform, but changed significantly with the structure of the habitat and during the season. Mean oviposition height per site (70.2±4.9 cm) was significantly higher than mean vegetation height (28.4±2.4 cm). Height of plants with egg clutches attached and oviposition height were significantly positively correlated. The results suggest that females try to oviposit as high as possible in the vegetation and on the plants selected. In accordance with this, the probability of egg parasitism and of winter egg clutch mortality significantly declined with increasing oviposition height. A preference of G. tanaceti for oviposition sites high up in the vegetation might therefore have evolved due to selection pressures by parasitoids and winter mortality.
Phylogeny of Australian Coptotermes (Isoptera: Rhinotermitidae) species inferred from mitochondrial COII sequences
Authors: Lo N. , Eldridge R.H. , Lenz M.
Published: August 2023

Six Australian species of Coptotermes are traditionally recognized, but recent cuticular hydrocarbon studies suggest that some of these may represent more than one species. An understanding of the phylogenetic diversity of Australian Coptotermes, particularly the pest species, is likely to be important for the improvement of termite management strategies. A study of phylogenetic relationships among species of this genus was performed, based on the mitochondrial cytochrome oxidase (COII) gene, comparing the data with recent data from Asian species. Representatives of the species C. lacteus (Froggatt), C. frenchi Hill and C. michaelseni Silvestri were each found to form closely related monophyletic groups, however representatives of C. acinaciformis (Froggatt) were not. For C. acinaciformis, representatives from northern mound-building populations were found to form a distinct group to southern, tree-nesting forms. Among southern C. acinaciformis, two Western Australian representatives were found to be divergent from other populations. The results suggest that C. acinaciformis probably represents a complex of species rather than one, as has been suggested previously. One unidentified Coptotermes sp. taxon from Melbourne was found to be divergent from other taxa. Notably, some Australian species were more closely related to Asian species than other Australian species.
Impact of human activity on the distribution of native and non-native cockroach species (Dictyoptera) in La Réunion and Mayotte
Authors: Boyer S. , Rivault C.
Published: August 2023

Establishment of non-native species and human-driven alteration of habitats are major causes of the decline of native faunas. Interference between native and non-native cockroach species was evaluated here by comparing their distribution areas in two oceanic islands: Mayotte and La Réunion. A factorial correspondence analysis showed that their presence is related to environmental parameters among which human activity, humidity and altitude are the three most important. Human activity and humidity favour establishment and development of non-native species, whereas altitude limits their presence. Non-native species form guilds (up to seven species). Their distribution areas overlap and illustrate their colonizing capacities. On the contrary, distribution areas of native species never overlap, although some co-occur with non-native species. Native species are more endangered when they are established in cultivated areas than when they are in protected natural areas.