bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrochemical significance and spectroscopy of tetratomic [H, P, S, O]
Authors: Esposito V. J. , Friskey J. M. , Trabelsi T. , Francisco J. S.
Published: January 2022

Context. Phosphorus is integral to life on Earth, and its role in the chemistry of the interstellar medium is highly debated and unknown. Only a handful of phosphorus-bearing species have been detected thus far, with the most recent confirmed detection taking place in 2014. The simultaneous detection of molecules such as PO, SH, and OH indicate the possibility of reactive intermediate species existing in the interstellar medium and circumstellar envelopes of evolved stars. To explore this possibility, the [H, P, S, O] tetratomic isomer family was characterized using high level ab initio methods.

Aims. The aim of this study is to provide rotational, vibrational, and electronic spectroscopic data to drive experimental and observational detection of new phosphorus and sulfur-bearing molecules. Additionally, chemical pathways are explored to explain possible reservoirs for the as of yet undetected PH and PS diatomic molecules.

Methods. Coupled cluster quantum chemistry methods were used to calculate the equilibrium electronic structure followed by the anharmonic treatment of the cubic and quartic force fields to obtain accurate rotational and vibrational data. Møller–Plesset perturbation theory in conjunction with coupled cluster methods were used to explore bimolecular reaction pathways. Multi-reference methods were then used to characterize the photochemical pathways of the excited electronic states and simulate the electronic absorption spectrum.

Results. The reaction between detected molecules SH and PO is highly exothermic and forms the HSPO isomer. Deeply submerged transition state barriers allow for facile isomerization to other isomers, especially HOPS. The dominant photochemical process predicted for HOPS is dissociation to form OH + PS, while that of HSPO is a combination of photodissociation to form H + SPO and SH + PO, depending on the wavelength of light absorbed. If PH and PS are formed in the early outflows from evolved stars, bimolecular reactions may act as a reservoir and partially account for their lack of detection to date. The electronic absorption spectrum is predicted to be congested in the 175–200 nm region for both HOPS and HSPO. Differentiating peaks exist >400 nm, which can be used for spectral assignment. Vibrationally corrected rotational constants and anharmonic vibrational frequencies were calculated to assist in the laboratory and observation identification of the most stable molecules. The PO stretch is predicted to be the most intense vibrational mode in both HOPS isomers, and a frequency difference of 20 cm−1 may prove to help differentiate the conformers in an experimental spectrum.
A rearrangement minimization problem corresponding top-Laplacian equation
Authors: Kao Chiu-Yen , Mohammadi Seyyed Abbas
Published: January 2022

In this paper a rearrangement minimization problem corresponding to solutions of thep-Laplacian equation is considered. The solution of the minimization problem determines the optimal way of exerting external forces on a membrane in order to have a minimum displacement. Geometrical and topological properties of the optimizer is derived and the analytical solution of the problem is obtained for circular and annular membranes. Then, we find nearly optimal solutions which are shown to be good approximations to the minimizer for specific ranges of the parameter values in the optimization problem. A robust and efficient numerical algorithm is developed based upon rearrangement techniques to derive the solution of the minimization problem for domains with different geometries in ℝ2and ℝ3.
Health risks, governance and changes in ecotourism paradigms during Covid19 pandemic, case study of Essaouira Province in Morocco
Authors: Boukherouk Mohamed , Cherkaoui Sidi Imad , El Filali Adil
Published: January 2022

Tourism merits on natural spaces are not exhausted, namely economic dynamics, development of the local population’s life conditions, species conservation and awareness of environmental protection. However, the damage caused by Coronavirus to natural and rural spaces has impacted such merits negatively, for example, suspension of tourism and recreation activities. Further, the rebirth of ecotourism will be slower and necessitates profound changes in travel design and service delivery. Hence, sustainability, sanitary and regulatory measures will probably help manage ecotourism systems. Nevertheless, these will be affected by the increase in exploring relations between nature and wildlife regarding zoonotic and vector-borne infections and the fragility of biodiversity. Because of his mobility, a tourist appears to be a potential pathogen transmission factor of infections to natural areas, local communities, ecotourism destinations, his country and the crossed ones. New procedures would reduce travel and control traveler’s behavior, and interactions between travelers and wild animals. The slowdown in demand may thus hinder the development of ecotourism. Sensitivity to epidemiological risk and vector-borne diseases will be greater and the need for health-friendly tourism will be further strengthened.
Construction of a new levelled cost model for energy storage based on LCOE and learning curve
Authors: Chai Zhe , Chen Xing , Yin Shuo , Jin Man , Wang Xin , Guo Xingwu , Lu Yao
Published: January 2022

New energy storage is essential to the realization of the “dual carbon” goal and the new power system with new energy as the main body, but its cost is relatively high and the economy is poor at present. This paper studies the levelized cost of new energy storage based on the whole life cycle perspective. Based on LCOE and learning curve methods, a new levelled cost estimation model and prediction model for energy storage are constructed. Based on the latest development status of electrochemical new energy storage, the levelized cost of energy of lithium-ion batteries, flow-aluminum batteries, and flow-zinc batteries were measured, the cost composition and proportion of various types of energy storage are analyzed, and on this basis, the levelized cost of lithium-ion batteries was predicted. Comparative analysis shows that the levelized cost per kilowatt-hour of lithium-ion batteries is the lowest. This article provides a certain reference for the construction and layout of energy storage on three sides of the source network and load.
Gamma-ray shielding calculations using empirical formulas for build-up factor: application to a practical case
To Professor J.J. Fletcher
Authors: Ondo Meye P. , Chaley C. , Loemba Mouandza S.Y. , Mabika Ndjembidouma B.C. , Ben-Bolie G.H.
Published: January 2022

Exposure of people to external ionizing radiation is controlled by time, distance and shielding. In the latter case, the radiation dose is reduced if shielding attenuates the radiation. The present study was aimed at comparing gamma-ray shielding calculation methods, the well-known trial-and-error method and a direct calculation method that make use of build-up factor’s empirical fitting formulas. The latter method was then applied to a practical case in gamma industrial radiography. The results showed that both methods provide comparable results. For high energies and high-density materials, it has been observed that all the build-up factor forms studied provide similar values. Contrariwise, it has also been observed that the linear form of the build-up factor seemed to underestimate shielding thickness for low gamma energies (lower than ≈ 1 MeV). Furthermore, the application of the method using empirical build-up factor functions to a practical case in gamma industrial radiography showed that the calculations are in agreement with the measurements carried out on the field. This demonstrates that this method is efficient and can still be used even though more sophisticated and accurate methods are now available.
Chiral Urea-Catalyzed Asymmetric Mannich Reaction of 3-Fluorooxindoles with α-Amidosulfones: Synthesis of Optically Active α-Fluoro-β-amino-oxindoles
Authors: Lin Yingjie , Duan Haifeng , Zhang Xin , Wei Zhonglin , Cao Jungang , Liang Dapeng
Published: January 2022

The asymmetric Mannich reaction of 3-fluorooxindoles and α-amidosulfones catalyzed by a chiral urea catalyst derived from quinine in presence of K3PO4 was developed. Through the asymmetric reaction, a series of α-fluoro-β-amino-oxindoles, containing a tertiary carbon stereocenter, could be obtained in high yields (up to 95%) with high enantioselectivity (95%) and diastereoselectivity (>99:1). Such α-fluoro-β-amino-oxindole compounds are expected to become candidates in the field of medicine.
Bone Remodeling after Ulna Head Replacement in Distal Radioulnar Joint Arthroplasty: A Radiographic Comparison between a Partial and a Total Ulna Head Concept
Authors: Brogren Elisabeth , Abramo Antonio , Tägil Magnus
Published: January 2022

Background Ulna head arthroplasty has become an eligible solution for injury or disease in the distal radioulnar joint. Bone resorption beneath the prosthetic head is often reported, but mechanism poorly understood.

Purpose The aims were to evaluate bone remodeling and radiological instability in two conceptually different distal radioulnar joint arthroplasties: the total and the partial ulna head replacement.

Patients and Methods We conducted a retrospective radiographic assessment of 51 ulna head arthroplasties; 26 Herbert ulna (total ulna head replacement) and 25 First Choice (partial ulna head replacement), to analyze periprosthetic bone resorption and radiologic instability. Intraoperative/immediate postoperative and 1-year radiographs were reviewed by two independent assessors. The radiographic follow-up averaged 13 (10–17) months. The size of the stem in relation to the diameter of the ulna (filling ratio) was measured on the intraoperative/immediate postoperative radiographs. Bone resorption beneath the collar of the prothesis was measured on the 1-year radiographs and expressed as a bone resorption index (BRI) between the length of the resorption and the length of the implant stem. Radiological stability was measured on both the preoperative and the 1-year lateral radiographs.

Results The total ulna head prothesis presented with more extensive bone resorption beneath the prosthetic head than the partial ulna head prothesis at 1-year post surgery (p <0.001). The filling ratio did not influence the 1-year bone resorption and there was no difference regarding radiological instability between the two prosthetic designs.

Conclusion The pattern of bone adaptions after an ulna head prothesis may differ due to design and concept of the prosthesis.
Distal Radioulnar Joint Locking with Bipolar Injury
Authors: Ichikawa Takeru , Suzuki Taku , Kimura Hiroo , Matsumura Noboru , Iwamoto Takuji , Nakamura Masaya , Matsumoto Morio
Published: January 2022

Background Locking of the distal radioulnar joint (DRUJ) induces restriction of the active and passive motion of pronation or supination of the forearm. Diagnosis of DRUJ locking due to a triangular fibrocartilage complex (TFCC) tear is sometimes difficult.

Case Description A 15-year-old female suffered from restriction of forearm supination after cast immobilization for the treatment of an elbow injury. The active and passive range of motion (ROM) of supination was 30 degrees, while the active ROM of pronation was normal. Radiographs of the elbow showed a fracture of the medial epicondyle and a fracture around the radial head. Radiographs of the wrist showed a subluxation of the ulnar head. Accurate diagnosis of supination restriction was difficult before surgery, so an operation was performed for the diagnosis and treatment. DRUJ locking was reduced manually and arthroscopic findings showed central perforation of the TFCC. Forearm supination improved to 90 degrees postoperatively.

Literature Review DRUJ locking due to a TFCC injury is rare and this condition with bipolar injury has not been reported.

Clinical Relevance DRUJ locking due to an injured TFCC should be considered as one of the differential diagnoses of supination contracture.
Novel GNE Gene Variants Associated with Severe Congenital Thrombocytopenia and Platelet Sialylation Defect
Authors: Zieger Barbara , Boeckelmann Doris , Anani Waseem , Falet Hervé , Zhu Jieqing , Glonnegger Hannah , Full Hermann , Andresen Felicia , Erlacher Miriam , Lausch Ekkehart , Fels Salome , Strahm Brigitte , Lang Peter , Hoffmeister Karin M.
Published: January 2022

The GNE gene encodes an enzyme that initiates and regulates the biosynthesis of N-acetylneuraminic acid, a precursor of sialic acids. GNE mutations are classically associated with Nonaka myopathy and sialuria, following an autosomal recessive and autosomal dominant inheritance pattern. Reports show that single GNE variants cause severe thrombocytopenia without muscle weakness. Using panel sequencing, we identified two novel compound heterozygous variants in GNE in a young girl with life-threatening bleedings, severe congenital thrombocytopenia, and a platelet secretion defect. Both variants are located in the nucleotide-binding site of the N-acetylmannosamin kinase domain of GNE. Lectin array showed decreased α-2,3-sialylation on platelets, consistent with loss of sialic acid synthesis and indicative of rapid platelet clearance. Hematopoietic stem cell transplantation (HSCT) normalized platelet counts. This is the first report of an HSCT in a patient with an inherited GNE defect leading to normal platelet counts.
Neutron flat-panel detector using In–Ga–Zn–O thin-film transistor
Authors: Fujiwara Takeshi , Miyoshi Hiroaki , Mitsuya Yuki , Yamada Norifumi L. , Wakabayashi Yasuo , Otake Yoshie , Hino Masahiro , Kino Koichi , Tanaka Masahito , Oshima Nagayasu , Takahashi Hiroyuki
Published: January 2022

Neutron imaging is a powerful tool for observing the internal structure of an object without destroying the object. Neutron imaging (neutron radiography) is a prominent application of neutrons but still requires significant improvements, for example, in sensitivity, resolution, radiation hardness, and handling of neutron imaging detectors. This paper presents the development and the first neutron imaging results of a neutron flat-panel detector (nFPD) based on an In–Ga–Zn–O (IGZO) thin-film transistor (TFT)/photodiode array coupled with a LiF/ZnS scintillator sheet. Direct photo-coupling to the scintillator increases the light collection efficiency. Moreover, unlike lens-coupled neutron cameras, the proposed detector is compact and easy to handle. Owing to the high off-state resistance of IGZO TFTs, their leakage current is lower than that of conventional TFTs, enabling the IGZO TFTs to hold an accumulated charge for a longer period of time and allowing longer exposure times for imaging. This would be a powerful feature for imaging at compact neutron sources with limited flux. This paper reports on the first neutron imaging results with an IGZO nFPD, its performance evaluation, and a demonstration of three-dimensional computed tomography with neutrons.
Subcritical excitation of zonal flow in drift wave turbulence
Authors: Meng Cong , Guo Zhibin
Published: January 2022

We report a subcritical excitation mechanism of zonal flow in drift wave turbulence. Employing the reductive perturbation method, it is shown that the evolution of eikonal phase of the drift wave is governed by a KdV-type equation in the (amplitude) modulational stable regime. A phase pulse train then emerges and generates potential vorticity barrier or staircases. The spatial structure of the zonal flow pattern is given analytically.
Experimental setup to fabricate Rb–Xe gas cells for atom spin gyroscopes
Authors: Yim S. H. , Lee D.-Y. , Lee S. , Kim M. M.
Published: January 2022

An experimental setup to fabricate atomic vapor cells for atom spin gyroscope application, containing 87Rb, 129Xe, 131Xe, N2, and H2, is described. The setup comprises a high-vacuum chamber, an 87Rb ampule, a glass cell, gas lines, and a turbopump. First, the glass cell is baked for a week at 450 °C to reduce outgassing from the inner walls of the glass cell. Next, rubidium atoms are evaporated into the cubic glass cell. Then, the cubic glass cell is cooled to 2 °C to increase the amount of 87Rb in the cubic glass cell while the vacuum chamber is heated to 100 °C. 6 Torr of 129Xe, 48 Torr of 131Xe, 140 Torr of N2, and 24 Torr of H2 are injected into the cubic glass cell. The sealing method employs pinch-off glass welding. The transverse spin relaxation times of 129Xe and 131Xe at a magnetic field of 6.2 µT applied to the quantization axis are measured to be 8.1 and 16.5 s, respectively, at a cell temperature of 96 °C using nuclear magnetic resonance spectroscopy. The pressure ratio between 129Xe and 131Xe is determined by comparing the output signals from our atom spin gyroscope. The signal-to-noise ratios are 2500 for 129Xe and 3333 for 131Xe, respectively, and the expected angular random walk of the atom spin gyroscope is 0.062°/h1/2 with a 1-Hz repetition rate.
Weakly nonlinear stability analysis of salt-finger convection in a longitudinally infinite cavity
Authors: Chou Yen-De , Hwang Wei-Shien , Solovchuk Maxim , Siddheshwar P. G. , Sheu Tony Wen-Hann , Chakraborty Symphony
Published: January 2022

This paper is a two-dimensional linear and weakly nonlinear stability analyses of the three-dimensional problem of Chang et al. [“Three-dimensional stability analysis for a salt-finger convecting layer,” J. Fluid Mech. 841, 636–653 (2018)] concerning salt-finger convection, which is seen when there is sideways heating and salting along the vertical walls along with a linear variation of temperature and concentration on the horizontal walls. A two-dimensional linear stability analysis is first carried out in the problem with the knowledge that the result could be different from those of a three-dimensional study. A two-dimensional weakly nonlinear stability analysis, that is, then performed points to the possibility of the occurrence of sub-critical motions. Stability curves are drawn to depict various instability regions. With the help of a detailed stability analysis, the stationary mode is shown to be the preferred one compared to oscillatory. Local nonlinear stability analysis of the system is done in a neighborhood of the critical Rayleigh number to predict a sub-critical instability region. The existence of a stable solution at the onset of a weakly nonlinear convective regime is indicated, allowing one to perform a bifurcation study in the problem. Heat and mass transports are discussed by analyzing the Nusselt number, Nu, and Sherwood number, Sh, respectively. A simple relationship is obtained between the Nusselt number and the Sherwood number exclusively in terms of the Lewis number, Le.
Torsional wave suppression in metashaft with shunted piezoelectric rings
Authors: Chen Jung-San , Lo Yen-Hsin , Huang Yu-Siang
Published: January 2022

This study investigates the bandgap tunability of a metashaft with periodic shunted piezoelectric rings. An analytical model based on the Bloch theory and the transfer matrix technique is developed to predict bandgap characteristics and the transmission of torsional vibration in the proposed structure. The location and width of the bandgap can be easily tailored by altering the electric parameters of shunt circuits. Compared with other shunt assemblies, the use of the negative capacitance resonant shunt enables the creation of a lower bandgap with a relatively wide bandwidth. Bandgap frequencies have a strong dependency on the inductance and capacitance but not on resistance. Moreover, the frequency with an unbounded loss factor coincides with the one of maximum attenuation. Multiple bandgaps can be achieved by adding extra sets of shunt circuits to the metashaft. Theoretical results have been validated by comparing them with finite element results. Our findings provide feasible guidelines in the design of torsional active control systems.
Experimental investigation on flow characteristics of compressible oscillating jet
Authors: Mohammadshahi Shabnam , Samsam-Khayani Hadi , Kim Kyung Chun
Published: January 2022

An experimental study was performed to investigate the characteristics of a self-sustained oscillating jet emitted from a double feedback channel fluidic oscillator under high pressure inlet conditions. The working fluid was N2 gas from a portable liquid nitrogen tank. The pressure, temperature, and flow rate were measured, and z-type schlieren visualization was performed to study the high-frequency oscillating jet at nozzle pressure ratios (NPRs) of 4–16. A proper orthogonal decomposition (POD) technique was performed on schlieren images, and a Fast Fourier transform was performed on time coefficients of POD modes to calculate the frequency of oscillations. The results show that for the examined NPRs, the frequency of the oscillating jet is independent of the pressure and flow rate, which contrasts with previous studies. However, the flow behavior varies when changing the NPR. The frequency did not increase with increasing supply pressure. In order to find the main reason for the fixed frequency, a second-order mass spring system was assumed. An equation is also proposed for obtaining the resonance frequency of the double feedback fluidic oscillator.
Weakly quasisymmetric near-axis solutions to all orders
Authors: Rodríguez E. , Sengupta W. , Bhattacharjee A.
Published: January 2022

We show that the equations satisfied by weakly quasisymmetric magnetic fields can be solved to arbitrarily high order in powers of the distance from the magnetic axis. This demonstration does not consider force balance. The existence of solutions requires an appropriate choice of parameters, most notably the toroidal current or rotational transform profiles. We do not prove that the expansion converges (it is likely divergent but asymptotic), and thus, the demonstration here should not be taken as definitive proof of the existence of global solutions. Instead, we provide a systematic construction of solutions to an arbitrarily high order.
Spectroscopic ellipsometry characterization of boron nitride films synthesized by a reactive plasma-assisted coating method
Authors: Hamano Takashi , Matsuda Takayuki , Asamoto Yuya , Noma Masao , Hasegawa Shigehiko , Yamashita Michiru , Urabe Keiichiro , Eriguchi Koji
Published: January 2022

The optical constants of boron nitride (BN) films on Si substrates were systematically investigated using spectroscopic ellipsometry. BN films with a wide variety of atomic compositions (B/N ratios) and bonding phases (sp2/sp3 ratios) were synthesized using a reactive plasma-assisted coating method, which consists of magnetically confined vacuum-arc discharge and electron-beam evaporation. A wide range of optical constants were assigned to various BN films via a model fitting procedure employing the Tauc–Lorentz optical model. The estimated film thicknesses corresponded with those determined using scanning electron microscopy. The optical constants of the films were found to be significantly dependent on their respective atomic compositions, which shows a transition from the semiconducting to the insulating phase in BN films in response to the deposition conditions. Ion bombardment during the film growth induced an increase in the refractive index along with an increase in the amount of the sp3 phase. Furthermore, the extinction coefficient increased substantially in the ultraviolet region in response to the generation of defects in the BN nano-network structures.
Synergistic effect of carrier velocity and density on chirality-induced spin selectivity in helical organic devices
Authors: Gao Teng , Tian Qipeng , Du Mengzhao , Zhang Longlong , Liu Xuan , Qin Wei , Xie Shijie
Published: January 2022

The synergistic effect of the carrier velocity and density is studied to understand chirality-induced spin selectivity (CISS) in helical spin-filtering devices. Unlike most previous theories that emphasize the asymmetry between the transmitted spin-related electron densities, we reveal two types of dynamics for the spin polarization: (i) spin conversion dynamics between spin-up and spin-down electrons and (ii) spin-dependent transport dynamics leading to different propagation velocities of spin-up and spin-down electrons. The former dominate in the high-bias-voltage regime by electron tunneling, while the latter dominate in the low-bias-voltage regime by polaron transport. Our theory reproduces well the recently observed extreme spin polarization under a certain bias voltage in a helical spin-filtering device, and it provides a general microscopic perspective for reconsidering CISS.
Molecular descriptors suggest stapling as a strategy for optimizing membrane permeability of cyclic peptides
Authors: Li Jianguo , Kannan Srinivasaraghavan , Aronica Pietro , Brown Christopher J. , Partridge Anthony W. , Verma Chandra S.
Published: January 2022

Cyclic peptides represent a promising class of drug candidates. A significant obstacle limiting their development as therapeutics is the lack of an ability to predict their membrane permeability. We use molecular dynamics simulations to assess the ability of a set of widely used parameters in describing the membrane permeability of a set of model cyclic peptides; the parameters include polar surface area (PSA), the number of hydrogen bonds, and transfer free energy between an aqueous phase and a membrane mimicking phase. These parameters were found to generally correlate with the membrane permeability of the set of cyclic peptides. We propose two new descriptors, the charge reweighted PSA and the non-polar surface area to PSA ratio; both show enhanced correlation with membrane permeability. This inspired us to explore crosslinking of the peptide to reduce the accessible surface area of the backbone polar atoms, and we find that this can indeed result in reductions in the accessible PSA. This gives reason to speculate that crosslinking may result in increased permeability, thus suggesting a new scaffold for the development of cyclic peptides as potential therapeutics.
Effects of temperature-dependent burn-in decay on the performance of triple cation mixed halide perovskite solar cells
Authors: Olanrewaju Yusuf A. , Orisekeh Kingsley , Oyelade Omolara V. , Koech Richard K. , Ichwani Reisya , Ebunu Abraham I. , Amune Daniel I. , Bello Abdulhakeem , Anye Vitalis C. , Oyewole Oluwaseun K. , Soboyejo Winston O.
Published: January 2022

The understanding of the degradation mechanisms in perovskite solar cells (PSCs) is important as they tend to degrade faster under exposure to heat and light conditions. This paper examines the temperature-dependent degradation of solution processed triple-cation mixed halide PSCs (Cs0.05(FA0.95MA0.05)0.95Pb(I0.9Br0.05)3). The PSCs were subjected to temperatures between 30 and 60 °C for 3 h (180 min) to evaluate their current–voltage performance characteristics. Temperature-induced changes in the layer and interfacial structure were also elucidated by scanning electron microscopy (SEM). Our results show that thermally induced degradation leads gradually to the burn-in decay of photocurrent density, which results in a rapid reduction in power conversion efficiency. The SEM images reveal thermally induced delamination and microvoid formation between the layers. The underlying degradation in the solar cell performance characteristics is associated with the formation of these defects (interfacial cracks and microvoids) during the controlled heating of the mixed halide perovskite cells. The electrochemical impedance spectroscopy analysis of the PSCs suggests that the device charge transport resistance and the interfacial capacitance associated with charge accumulation at the interfaces both increase with extended exposure to light.
Strain mapping in interband cascade lasers
Authors: Yu Tian , Ning Chao , Sun Ruixuan , Liu Shu-Man , Zhang Jinchuan , Liu Junqi , Wang Lijun , Zhuo Ning , Zhai Shenqiang , Ye Xiaoling , Li Yuan , Liu Fengqi
Published: January 2022

A typical interband cascade laser wafer contains more than 2000 multilayers composed of InAs, AlSb, GaSb, and GaInSb. The lattice constants of the three materials except GaSb have a certain degree of mismatch with the GaSb substrate. Therefore, to grow a high-quality epitaxial layer, it is necessary to optimize the growth conditions to achieve strain balance in the entire epitaxial layer. In this work, the strained superlattice structure was characterized via scanning transmission electron microscopy and high-resolution x-ray diffraction. The strain distribution was mapped using geometric phase analysis of high-angle annular dark-field images. We demonstrate that strain compensation has been achieved in both the InAs/AlSb superlattice clad layers and the InAs/InGaSb/InAs W quantum well active region.
The formation of a one-dimensional van der Waals selenium crystal from the three-dimensional amorphous phase: A spectroscopic signature of van der Waals bonding
Authors: Krbal Milos , Kolobov Alexander V. , Fons Paul , Saito Yuta , Belev George , Kasap Safa
Published: January 2022

Trigonal selenium is a prototypical one-dimensional (1D) van der Waals (vdW) solid, where covalently bonded helical chains are held together by weaker vdW forces. In this work, we have studied structural transformation from a three-dimensional amorphous phase of non-interacting Se chains into a 1D vdW crystal using x-ray absorption spectroscopy. The crystallization process and establishment of vdW interaction are accompanied by elongation and weakening of covalent Se-Se bonds. We have found a unique signature in the x-ray absorption near-edge structure spectrum that is associated with vdW bonds and can be used to identify the formation of the latter. We believe that a similar approach can be used to study other 1D vdW solids, such as transition-metal trichalcogenides, and particularly stress the usefulness of x-ray absorption spectroscopy to identify vdW bonds.
Rumphius and
Authors: Fensham Roderick
Published: January 2022

In 1743, Georg Rumphius described a tree from the island of Seram in Herbarium Amboinense as Arbor Versicolor (now known as Eucalyptus deglupta Blume). Thus, the first European name for a species in the iconic Australian genus of Eucalyptus was coined decades before the British collected specimens in Australia, and before it was given its current name by a French botanist in 1789. The English translation of Rumphius’ description (see Supplementary Material) also includes vernacular names for Eucalyptus deglupta—some of many names applied to this species as it occurs from New Britain to Mindanao in the Philippines. While neither Rumphius’ name nor vernacular names for E. deglupta are recognised in current Western botanical nomenclature, the naming of Eucalyptus and other genera now recognised as Acacia, Casuarina and Melaleuca confirm the role of the eminent naturalist Rumphius in the history of Australian botany.
Synchronous abortion events in the grey-headed flying-fox (Pteropus poliocephalus)
Authors: Mo Matthew , Meade Jessica , Price Janina , Maisey Jacquie , Welbergen Justin A.
Published: January 2022

Context The grey-headed flying-fox (Pteropus poliocephalus) is a vulnerable species endemic to eastern and south-eastern Australia. Environmental stressors are important contributors to physiological stress, leading to synchronous abortions. Aims We investigate the possibilities of weather conditions and anthropogenic disturbances contributing to synchronous abortion events in a grey-headed flying-fox (Pteropus poliocephalus) roost. Methods We recorded observations of two synchronous abortion events in a flying-fox roost in Tamworth, New South Wales (NSW), Australia, during October 2017 and August 2019. Key results Roost searches found ∼200 (October 2017) and 41 (August 2019) foetuses, equating to ∼0.5% and >0.1% of adults present at the time, respectively. Neither event was associated with significantly colder than average temperatures nor hot extremes (>42°C). Synchronous abortions cannot be easily attributed to unusually cold or hot site conditions. However, the surrounding region suffered from rainfall deficiencies, known to cause failure of flowering in diet plants, in the 6 months preceding both abortion events. Notably, no rainfall deficiency occurred in 6 months preceding August 2015 when colony size was also large, and no synchronous abortions occurred. Conclusions Natural background rates of abortions are unlikely to explain the abortion events. The 2017 abortion event coincided with intense harassment of flying-foxes using noise agents; thus, it is possible that physiological stress was a contributor. The 2019 abortion event was associated with harassment of lesser intensity but coincided with a severe food shortage throughout surrounding regions. Implications While it is not possible to attribute the synchronous abortion events conclusively to a single factor, the results suggest that the combination of chronic physiological stress from food shortage and acute stress from anthropogenic disturbance may have precipitated both synchronous abortion events.
Pseudouridine synthase 7 is an opportunistic enzyme that binds and modifies substrates with diverse sequences and structures
Authors: Purchal Meredith K. , Eyler Daniel E. , Tardu Mehmet , Franco Monika K. , Korn Megan M. , Khan Taslima , McNassor Ryan , Giles Rachel , Lev Katherine , Sharma Hari , Monroe Jeremy , Mallik Leena , Koutmos Markos , Koutmou Kristin S.
Published: January 2022

Significance

Pseudouridine is among the most-abundant RNA modifications. We present a framework for conceptualizing how eukaryotic pseudouridine synthases select their substrates. This work reveals the structure of yeast pseudouridine synthase 7 (Pus7) and presents cell-based and biochemical investigations of enzyme binding and activity. We demonstrate that Pus7 interacts promiscuously with RNAs containing UG
U
AR sequences. Our observations raise the question of why these enzymes only modify <5% of UG
U
AR sequences in the transcriptome, suggesting that factors beyond inherent enzyme properties—such as protein localization, local RNA structure, and RNA–protein interactions—principally shape Pus7 substrate selection. These findings support a role for Pus7 in providing cells with a mechanism to rapidly alter protein synthesis in response to cellular conditions.
Phagocytosis and self-destruction break down dendrites of
Drosophila
sensory neurons at distinct steps of Wallerian degeneration
Authors: Ji Hui , Sapar Maria L. , Sarkar Ankita , Wang Bei , Han Chun
Published: January 2022

Significance

Mutations in the nicotinamide adenine dinucleotide (NAD
+
) biosynthesis pathway are associated with progressive neurodegeneration; neuronal injury causes rapid breakdown of damaged axons and dendrites. NAD
+
reduction is thought to underlie both types of degeneration by inducing neuronal self-destruction. Here, we show that phagocytosis, instead of self-destruction, drives degeneration of
Drosophila
sensory dendrites in both injury and genetic NAD
+
disruptions. Mechanistically, phagocytosis is induced earlier than self-destruction by these manipulations, as a result of phosphatidylserine exposure on the dendrite surface. In addition, injured dendrites exhibit unique calcium dynamics and only partially require the axon-death factor Axed for self-destruction. Thus, our results suggest important contributions of phagocytosis to NAD
+
-related neurodegenerative diseases and highlight the difference between dendrite and axon degeneration.
Remodeling of lateral geniculate nucleus projections to extrastriate area MT following long-term lesions of striate cortex
Authors: Atapour Nafiseh , Worthy Katrina H. , Rosa Marcello G. P.
Published: January 2022

Significance

Lesions of the primary visual area (V1) in primates cause blindness by severing the main pathway which brings information from the thalamus to the cortex. However, some visual abilities remain, which are hypothesized to be mediated by thalamic neurons that innervate surviving areas such as the middle temporal (MT) cortex. We found that V1 lesions trigger long-term plasticity in the connections between the thalamus and cortex, including the emergence of a pathway that brings information to MT from cell populations that would normally project to V1. These results reveal potential targets for rehabilitation strategies to ameliorate the consequences of cortical blindness.
Tourism and Local Community Engagement in Costa Rica
Authors: Seabolt Katie , Ward-Perkins David , Couttet Alizée , Jacob Camille , Liu Jiatong , Zhou Chutong
Published: January 2022

Unique Adventures is a Costa Rican adventure company owned by two female entrepreneurs, Maricruz Pereira and Soledad Naranjo. They offer custom-made packages for visitors wanting to experience Costa Rica from the inside, in the form of adventure tourism, wellness, relaxation and interaction with local communities.

Information

Written on the basis of material provided by Maricruz Pereira and Soledad Naranjo of Unique Adventures.

© CAB International 2022
Resistance matching materials nanoarchitectonics for better performances in water evaporation-driven generators
Authors: Gao Feng , Yu Zhiqiang , Zang Yunhao , Qu Jiangying , Hua Kaihui , Sun Zhenzhong
Published: January 2022

The improvement of electricity production for water evaporation-driven generators (WEGs) remains a challenge. Herein, two types of WEGs were designed to study the resistance matching for improving the electricity production using the method of nanoarchitectonics. One type of reduced graphene oxide/carbon nanotube (RGO/CNT) WEG was constructed using RGO with adjustable resistances as working material and CNTs with fixed resistance as electrode material. The other type of graphene oxide (GO)/RGO WEG was constructed using RGO with adjustable resistance as electrode material and GO with fixed resistance was used as working material. The open circuit voltage of RGO/CNT increased from 15 to 56 mV and then decreased to 22 mV with increasing RGO resistance. The short circuit current of RGO/CNT also first increased and then decreased. The performance of GO/RGO was similar with that of RGO/CNT. Typically, the RGO/CNT and GO/RGO WEG showed the highest performance when the working material to electrode material resistance ratio was 2272 and 2365, respectively. It showed that the best resistance ratio of working material to electrode material was in the range of 2000–2500, which helped to improve about 2–5 times of electricity efficiency in the WEG. The present work provides a new direction for optimizing performance of WEGs.
Cathodoluminescence mapping of electron concentration in MBE-grown GaAs:Te nanowires
Authors: Tong Capucine , Bidaud Thomas , Koivusalo Eero , Rizzo Piton Marcelo , Guina Mircea , Galeti Helder Vinicius Avanço , Galvão Gobato Yara , Cattoni Andrea , Hakkarainen Teemu , Collin Stéphane
Published: January 2022

Cathodoluminescence mapping is used as a contactless method to probe the electron concentration gradient of Te-doped GaAs nanowires. The room temperature and low temperature (10 K) cathodoluminescence analysis method previously developed for GaAs:Si is first validated on five GaAs:Te thin film samples, before extending it to the two GaAs:Te NW samples. We evidence an electron concentration gradient ranging from below 1 × 1018 cm−3 to 3.3 ×1018 cm−3 along the axis of a GaAs:Te nanowire grown at 640 °C, and a homogeneous electron concentration of around 6–8 × 1017 cm−3 along the axis of a GaAs:Te nanowire grown at 620 °C. The differences in the electron concentration levels and gradients between the two nanowires is attributed to different Te incorporation efficiencies by vapor–solid and vapor–liquid–solid processes.
Exploring kinematics graphs using Arduino and an interactive Excel spreadsheet
Authors: Ladeira V B , Calheiro L C , Goncalves A M B
Published: January 2022

We present a low-cost apparatus using Arduino and an ultrasonic distance sensor that permits students to learn about motion graphs more intuitively. Using an interactive interface built using Excel and an add-on, the students can see a graph of position or velocity as a function of time. They are invited to reproduce the proposed motion graph moving themselves in front of the sensor. The Excel spreadsheet presents a real-time of their movement together with the reference.
A liquid lens-based optical sensor for tactile sensing
Authors: Yang Hui , Fu Jian , Cao Ruimin , Liu Jiaqi , Wang Lihui
Published: January 2022

Tactile sensing plays a crucial role in robot manipulation, robot interaction, and health monitoring. Because of high sensitivity, simple structure, and superior interference immunity, optical tactile sensors based on optical imaging or optical conduction have been one of the most active research. Herein, a novel liquid lens-based optical sensor (LLOS) is presented. Different with existed optical tactile sensors, the main body of the proposed sensor belongs to a variable-focus optical lens with a liquid-membrane structure, and its focal length is changed with the contact force, thereby changing the propagation direction of light and affecting the perceived light intensity of the photosensitive element. By conducting some testing experiments, the LLOS demonstrates fast response (about 0.021 s), stable dynamic response characteristics, and good linearity (R-squared is about 0.99), repeated measurement accuracy (<0.006 V), and measurement accuracy (<0.2 N). Hence, the LLOS provides a new and promising method to measure tactile and has potential application in robotics nondestructive grasping and interactive input devices.
Harmonic analysis of isotropic fields on the sphere with arbitrary masks
Authors: Grasshorn Gebhardt Henry S. , Doré Olivier
Published: January 2022

Obtaining constraints from the largest scales of a galaxy survey is
challenging due to the survey mask allowing only partial measurement of large
angular modes. This scatters information from the harmonic-space 2-point
function away from the diagonal and introduces coupling between modes. In
this paper, we derive a custom eigenbasis adapted to any particular survey
geometry so that all information is retained on the diagonal. At the expense
of a somewhat complex pixel- and selection-function-window, the result is a
diagonal 2-point function with a simple shot noise, and a diagonal covariance
matrix in the case of a Gaussian random field. We derive the basis on the
surface of a sphere, and we use it to construct a 3D spherical Fourier-Bessel
power spectrum estimator assuming a survey geometry that is separable in the
angular and radial directions.
Diluted axion star collisions with neutron stars
Authors: Bai Yang , Du Xiaolong , Hamada Yuta
Published: January 2022

Diluted axion star, a self-gravitating object with the quantum pressure balancing gravity, has been predicted in many models with a QCD axion or axion-like particle. It can be formed in the early universe and composes a sizable fraction of dark matter. One could detect the transient radio signals when it passes by a magnetar with the axion particle converted into photon in the magnetic field. Using both numerical and semi-analytic approaches, we simulate the axion star's dynamic evolution and estimate the fraction of axion particles that can have a resonance conversion during such a collision event. We have found that both self-gravity and quantum pressure are not important after the diluted axion star enters the Roche radius. A free-fall approximate can capture individual particle trajectories very well. With some optimistic cosmological and astrophysical assumptions, the QCD axion parameter space can be probed from detecting such a collision event by radio telescopes.
Space-borne atom interferometric gravitational wave detections. Part II. Dark sirens and finding the one
Authors: Yang Tao , Lee Hyung Mok , Cai Rong-Gen , Choi Han Gil , Jung Sunghoon
Published: January 2022

In this paper, we investigate the potential of dark sirens by the space-borne atom interferometric gravitational-wave detectors to probe the Hubble constant. In the mid-frequency band, the sources live a long time. The motion of a detector around the Sun as well as in Earth orbit would induce large Doppler and reorientation effects, providing a precise angular resolution. Such precise localization for the GW sources makes it possible to observe the dark sirens with only one potential host galaxy, which are dubbed “golden dark sirens”. We construct the catalogs of golden dark sirens and estimate that there are around 79 and 35 golden dark sirens of binary neutron stars (BNS) and binary black holes (BBH) that would be pass the detection threshold of AEDGE in 5 years. Our results show that with 5, 10, and all 79 golden dark BNS tracked by AEDGE one can constrain H
0 at 5.5%, 4.1%, and 1.8% precision levels. With 5, 10, and all 35 golden dark BBH one can constrain H
0 at 2.2%, 1.8%, and 1.5% precision levels, respectively. It suggests that only 5–10 golden dark BBH by AEDGE are sufficient to arbitrate the current tension between local and high-z measurements of H
0.
The H2S online detection in gaseous media using diode laser absorption spectroscopy in the range of 4860–4880 cm−1
Authors: Kireev S V , Kondrashov A A , Rybakov M A , Shnyrev S L , Sultangulova A I
Published: January 2022

This paper reports on experimental measurement of H2S absorption in the spectral range of 4860–4880 cm−1 by means of diode laser absorption spectroscopy, and determines the H2S spectral absorption line in the generation area of the laser used, most promising in terms of H2S detection using this method.
Enhancing steered coherence in the Heisenberg model using Dzyaloshinsky–Moriya and Kaplan–Shekhtman–Entin-Wohlman–Aharony interactions
Authors: Xie Yu-Xia , Liu Xin-Yu
Published: January 2022

Steered coherence characterizes the ability of one party to steer the coherence of another when they share a bipartite state. It is crucial to control its strength so as to use it as a resource for practical applications. We investigate average steered coherence (ASC) in the Heisenberg XXZ model. It is found that for the thermal state at finite temperature, the ASC can always be noticeably enhanced by adjusting the Dzyaloshinsky–Moriya and Kaplan–Shekhtman–Entin-Wohlman–Aharony interactions. There are also parameter regions in which the ASC approaches to its maximum. This result suggests an alternative for manipulating ASC in a spin system.
Soliton mode of terahertz radiation generation using picosecond laser pulses with tilted wave fronts
Authors: Sazonov S V , Ustinov N V
Published: January 2022

The soliton-like mode for highly efficient generation of terahertz radiation in a quadratically nonlinear medium by means of optical pulses with tilted wave fronts is investigated. For optical and terahertz pulses, a system of the Zakharov–Boussinesq type equations describing the process of generation at arbitrary angles of the tilt of wave fronts is derived. Various cases of the soliton generation are analyzed. It is shown that the tilt of wave fronts is fundamental for the formation of the optical-terahertz solitons of a new type, which we call dispersionless solitons.