bluuebunny/crossref_metadata_2025 huggingface dataset:
Spotlight on the Clinician in the Life Participation Approach to Aphasia: Balancing Relationship-Centered Care and Professionalism
Authors: Cohen-Schneider Rochelle , Chan Melodie T. , McCall Denise M. , Tedesco Allison M. , Abramson Ann P.
Published: February 2020

Background

Speech-language pathologists make clinical decisions informed by evidence-based theory and “beliefs, values and emotional experiences” (Hinckley, 2005, p. 265). These subjective processes, while not extensively studied, underlie the workings of the therapeutic relationship and contribute to treatment outcomes. While speech-language pathologists do not routinely pay attention to subjective experiences of the therapeutic encounter, social workers do. Thus, the field of social work makes an invaluable contribution to the knowledge and skills of speech-language pathologists.

Purpose

This clinical focus article focuses on the clinician's contribution to the therapeutic relationship by surfacing elements of the underlying subjective processes.

Method

Vignettes were gathered from clinicians in two community aphasia programs informed by the principles of the Life Participation Approach to Aphasia.

Results and Discussion

By reflecting on and sharing aspects of clinical encounters, clinicians reveal subjective processing occurring beneath the surface. The vignettes shed light on the following clinical behaviors: listening to the client's “whole self,” having considerations around self-disclosure, dealing with biases, recognizing and surfacing clients' identities, and fostering hope. Speech-language pathologists are given little instruction on the importance of the therapeutic relationship, how to conceptualize this relationship, and how to balance this relationship with professionalism. Interprofessional collaboration with social workers provides a rich opportunity to learn ways to form and utilize the benefits of a strong therapeutic relationship while maintaining high standards of ethical behavior.

Conclusion

This clinical focus article provides speech-language pathologists with the “nuts and bolts” for considering elements of the therapeutic relationship. This is an area that is gaining traction in the field of speech-language pathology and warrants further investigation.
The Obligation of Listening: Caring for Patients With Chronic Dysphagia Through Illness Narratives
Authors: Xia Jinxu Bridget
Published: February 2020

Purpose

Chronic conditions affect the lives of thousands of people in the United States. Dysphagia is a symptom that co-occurs with many chronic conditions. This presents unique challenges to speech-language pathologists (SLPs) who work with patients that are physically and psychosocially burdened by chronic dysphagia. Clinical decisions in chronic care are characterized by context-dependent complexities. There is a theoretical framework in bioethics callednarrative ethics, which suggests that engaging with patients' illness narratives informs patient-centered decision making and that exploring contexts is essential to provision of care.

Conclusion

Using a narrative approach in decision making in chronic dysphagia helps contextualize the symptoms and supports clinicians to form individualized treatment plans that better suit patients' health care and psychosocial needs.
Effective capacity of multi‐unicast flows using network coded‐ARQ
Authors: Bouteggui M. , Merazka F. , Kurt G.K.
Published: February 2020

In this Letter, the authors consider a multi‐unicast flow wireless communication system with a retransmission scheme. The effective capacity (EC) is used as a performance metric in order to make use of the recurrence relation approach. They also take advantage of network coding (NC) as combined with automatic repeat request (ARQ) protocol (NC‐ARQ), for more robust communication. The authors' main contribution, in this work, is the derivation of the EC for M‐user NC‐ARQ using only the opportunity of XoR‐ing M packets. They then, focus on a 3‐user system and derive the EC using the opportunity of XoR‐ing packets for 3 and 2 users. An interesting result is the fact that, contrary to expectation, as the number of users in a network that uses NC‐ARQ increases, the performance in terms of EC increases as well, depending on how the sender schedules and manages the retransmissions.
Multiband RadioAstron space VLBI imaging of the jet in quasar S5 0836+710
Authors: Vega-García L. , Lobanov A. P. , Perucho M. , Bruni G. , Ros E. , Anderson J. M. , Agudo I. , Davis R. , Gómez J. L. , Kovalev Y. Y. , Krichbaum T. P. , Lisakov M. , Savolainen T. , Schinzel F. K. , Zensus J. A.
Published: February 2020

Context. Detailed studies of relativistic jets in active galactic nuclei (AGN) require high-fidelity imaging at the highest possible resolution. This can be achieved using very long baseline interferometry (VLBI) at radio frequencies, combining worldwide (global) VLBI arrays of radio telescopes with a space-borne antenna on board a satellite.

Aims. We present multiwavelength images made of the radio emission in the powerful quasar S5 0836+710, obtained using a global VLBI array and the antenna Spektr-R of the RadioAstron mission of the Russian Space Agency, with the goal of studying the internal structure and physics of the relativistic jet in this object.

Methods. The RadioAstron observations at wavelengths of 18 cm, 6 cm, and 1.3 cm are part of the Key Science Program for imaging radio emission in strong AGN. The internal structure of the jet is studied by analyzing transverse intensity profiles and modeling the structural patterns developing in the flow.

Results. The RadioAstron images reveal a wealth of structural detail in the jet of S5 0836+710 on angular scales ranging from 0.02 mas to 200 mas. Brightness temperatures in excess of 1013 K are measured in the jet, requiring Doppler factors of ≥100 for reconciling them with the inverse Compton limit. Several oscillatory patterns are identified in the ridge line of the jet and can be explained in terms of the Kelvin–Helmholtz (KH) instability. The oscillatory patterns are interpreted as the surface and body wavelengths of the helical mode of the KH instability. The interpretation provides estimates of the jet Mach number and of the ratio of the jet to the ambient density, which are found to be Mj ≈ 12 and η ≈ 0.33. The ratio of the jet to the ambient density should be conservatively considered an upper limit because its estimate relies on approximations.
Horizontal shear instabilities in rotating stellar radiation zones
Authors: Park J. , Prat V. , Mathis S.
Published: February 2020

Context. Rotational mixing transports angular momentum and chemical elements in stellar radiative zones. It is one of the key processes for modern stellar evolution. In the past two decades, an emphasis has been placed on the turbulent transport induced by the vertical shear instability. However, instabilities arising from horizontal shear and the strength of the anisotropic turbulent transport that they may trigger remain relatively unexplored. The weakest point of this hydrodynamical theory of rotational mixing is the assumption that anisotropic turbulent transport is stronger in horizontal directions than in the vertical one.

Aims. This paper investigates the combined effects of stable stratification, rotation, and thermal diffusion on the horizontal shear instabilities that are obtained and discussed in the context of stellar radiative zones.

Methods. The eigenvalue problem describing linear instabilities of a flow with a hyperbolic-tangent horizontal shear profile was solved numerically for a wide range of parameters. When possible, the Wentzel–Kramers–Brillouin–Jeffreys (WKBJ) approximation was applied to provide analytical asymptotic dispersion relations in both the nondiffusive and highly diffusive limits. As a first step, we consider a polar f-plane where the gravity and rotation vector are aligned.

Results. Two types of instabilities are identified: the inflectional and inertial instabilities. The inflectional instability that arises from the inflection point (i.e., the zero second derivative of the shear flow) is the most unstable when at a zero vertical wavenumber and a finite wavenumber in the streamwise direction along the imposed-flow direction. While the maximum two-dimensional growth rate is independent of the stratification, rotation rate, and thermal diffusivity, the three-dimensional inflectional instability is destabilized by stable stratification, while it is stabilized by thermal diffusion. The inertial instability is rotationally driven, and a WKBJ analysis reveals that its growth rate reaches the maximum value of √f(1 − f) in the inviscid limit as the vertical wavenumber goes to infinity, where f is the dimensionless Coriolis parameter. The inertial instability for a finite vertical wavenumber is stabilized as the stratification increases, whereas it is destabilized by the thermal diffusion. Furthermore, we found a selfsimilarity in both the inflectional and inertial instabilities based on the rescaled parameter PeN2 with the Péclet number Pe and the Brunt–Väisälä frequency N.
Trend to equilibrium for systems with small cross-diffusion
Authors: Alasio Luca , Ranetbauer Helene , Schmidtchen Markus , Wolfram Marie-Therese
Published: February 2020

This paper presents new analytical results for a class of nonlinear parabolic systems of partial different equations with small cross-diffusion which describe the macroscopic dynamics of a variety of large systems of interacting particles. Under suitable assumptions, we prove existence of classical solutions and we show exponential convergence in time to the stationary state. Furthermore, we consider the special case of one mobile and one immobile species, for which the system reduces to a nonlinear equation of Fokker–Planck type. In this framework, we improve the convergence result obtained for the general system and we derive sharper L∞-bounds for the solutions in two spatial dimensions. We conclude by illustrating the behaviour of solutions with numerical experiments in one and two spatial dimensions.
Bone Substitutes in Orthopaedic Surgery: Current Status and Future Perspectives
Authors: Busch André , Wegner Alexander , Haversath Marcel , Jäger Marcus
Published: February 2020

Bone replacement materials have been successfully supplied for a long time. But there are cases, especially in critical sized bone defects, in which the therapy is not sufficient. Nowadays, there are multiple bone substitutes available. Autologous bone grafts remain the “gold standard” in bone regeneration. Yet, donor-site morbidity and the available amount of sufficient material are limitations for autologous bone grafting. This study aimed to provide information about the current status in research regarding bone substitutes. We report on the advantages and drawbacks of several bone substitutes. At the end, we discuss the current developments of combining ceramic substitutes with osteoinductive substances.
Efficacy and safety of endoscopic ultrasound-guided therapy versus direct endoscopic glue injection therapy for gastric varices: systematic review and meta-analysis
Authors: Mohan Babu P. , Chandan Saurabh , Khan Shahab R. , Kassab Lena L. , Trakroo Sushruth , Ponnada Suresh , Asokkumar Ravishankar , Adler Douglas G.
Published: February 2020

Background Gastric variceal bleeding carries significant mortality in the setting of portal hypertension. Among the endoscopic treatment options, endoscopic ultrasound (EUS)-guided glue and/or coil injection is a novel approach, but its role in the treatment of gastric varices is not established due to a lack of robust data.

Methods We conducted a comprehensive search of several databases (inception to June 2019) to identify studies evaluating EUS in the treatment of gastric varices. Our primary goals were to estimate the pooled rates of treatment efficacy, obliteration and recurrence of gastric varices, early and late rebleeding, and adverse events with EUS-guided therapy in gastric varices. We also searched for studies that evaluated direct endoscopic glue (END-glue) injection for treatment of gastric varices, and used the pooled rates as comparators.

Results 23 studies (851 patients) evaluating EUS-guided therapy were included. The pooled treatment efficacy was 93.7 % (95 % confidence interval [CI] 89.5 – 96.3, I
2 = 53.7), gastric varices obliteration was 84.4 % (95 %CI 74.8 – 90.9, I
2 = 77), gastric varices recurrence was 9.1 % (95 %CI 5.2 – 15.7, I
2 = 32), early rebleeding was 7.0 % (95 %CI 4.6 – 10.7, I
2 = 0), and late rebleeding was 11.6 % (95 %CI 8.8 – 15.1, I
2 = 22). The rates were comparable to END-glue therapy (28 studies, 3467 patients) except for obliteration, which was significantly better with EUS-guided therapy. On subgroup analysis, EUS-coil/glue combination showed superior outcomes.

Conclusions EUS-guided therapy demonstrated clinical efficacy for treatment of gastric varices in terms of obliteration, recurrence, and long-term rebleeding, and may be superior to END-glue.
Efficient Approaches for the Synthesis of Diverse α-Diazo Amides
Authors: Nelson Adam , Chow Shiao , Green Adam I. , Arter Christopher , Liver Samuel , Leggott Abbie , Trask Luke , Karageorgis George , Warriner Stuart
Published: February 2020

Metal-catalysed carbenoid chemistry can be exploited for the synthesis of diverse ranges of small molecules from α-diazo carbonyl compounds. In this paper, three synthetic approaches to α-diazo amides are described, and their scope and limitations are determined. On the basis of these synthetic studies, recommendations are provided to assist the selection of the most appropriate approach for specific classes of product. The availability of practical and efficient syntheses of diverse α-diazo acetamides is expected to facilitate the discovery of many different classes of bioactive small molecules.
The Financial and Clinical Impact of an Electronic Health Record Integrated Pathway in Elective Colon Surgery
Authors: Austrian Jonathan S. , Volpicelli Frank , Jones Simon , Bernstein Mitchell A. , Padikkala Jane , Bagheri Ashley , Blecker Saul
Published: February 2020

Background Enhanced Recovery after Surgery (ERAS) pathways have been shown to reduce length of stay, but there have been limited evaluations of novel electronic health record (EHR)-based pathways. Compliance with ERAS in real-world settings has been problematic.

Objective This article evaluates a novel ERAS electronic pathway (E-Pathway) activity integrated with the EHR for patients undergoing elective colorectal surgery.

Methods We performed a retrospective cohort study of surgical patients age ≥ 18 years hospitalized from March 1, 2013 to August 31, 2016. The primary cohort consisted of patients admitted for elective colon surgery. We also studied a control group of patients undergoing other elective procedures. The E-Pathway was implemented on March 2, 2015. The primary outcome was variable costs per case. Secondary outcomes were observed to expected length of stay and 30-day readmissions.

Results We included 823 (470 and 353 in the pre- and postintervention, respectively) colon surgery patients and 3,415 (1,819 and 1,596 in the pre- and postintervention) surgical control patients in the study. Among the colon surgery cohort, there was statistically significant (p = 0.040) decrease in costs of 1.28% (95% confidence interval [CI] 0.06–2.48%) per surgical encounter per month over the 18-month postintervention period, amounting to a total savings of $2,730 per patient at the 1-year postintervention period. The surgical control group had a nonsignificant (p = 0.231) decrease in monthly costs of 0.57% (95% CI 1.51 to – 0.37%) postintervention. For the 30-day readmission rates, there were no statistically significant changes in either cohort.

Conclusion Our study is the first to report on the reduced costs after implementation of a novel sophisticated E-Pathway for ERAS. E-Pathways can be a powerful vehicle to support ERAS adoption.
Classical Cesarean Section
Authors: Kan Amano
Published: February 2020

Cesarean section is the most common surgery in obstetrics. Several techniques are proposed according to the indication and the degree of urgency. Usually laparotomy followed by hysterotomy with a low transverse incision is preferable. However, in cases in which it is difficult to access the lower uterine segment, such as that in preterm labor, dense adhesion, placenta previa/accrete a vertical hysterotomy (classical cesarean section) may be needed. Although a smooth and gentle delivery of the fetus is possible through the vertical incision, uterine closure is technically difficult. To decrease the risks of hemorrhage and adhesion, a speedy and skillful technique is mandatory. The most serious risk of vertical incision in the contractile corpus is uterine rupture in the subsequent pregnancy. Therefore, cases of prior classical cesarean section are contraindicated for trial of labor after cesarean section.
Clinical Results of Combined ACL and Anterolateral Ligament Reconstruction: A Narrative Review from the SANTI Study Group
Authors: Saithna Adnan , Daggett Matt , Helito Camilo Partezani , Monaco Edoardo , Franck Florent , Vieira Thais Dutra , Pioger Charles , Kim Jin Goo , Sonnery-Cottet Bertrand
Published: February 2020

Lateral extraarticular procedures (LEAPs) in the anterior cruciate ligament (ACL)-injured knee were widely abandoned in the 1990s but have seen a recent resurgence. The aim of this review was to demonstrate that anterolateral ligament reconstruction (ALLR) is associated with evidence of significant advantages and no evidence of historical concerns. A narrative review of the literature was performed. Combined ACL + ALLR is associated with improved outcomes when compared against isolated ACL reconstruction, including a significantly lower risk of ACL graft rupture (hazard ratio [HR]: 0.327, 95% CI: 0.130–0.758), a significantly lower risk of reoperation for secondary meniscectomy following medial meniscal repair at the time of ACL reconstruction (HR: 0.443, 95% CI: 0.218–0.866), significantly increased likelihood of return to the preinjury level of sport following primary (odds ratio [OR]: 1.938, 95% CI: 1.174–3.224) and revision ACL reconstruction (57.1 vs. 25.6%, respectively; p = 0.008), and in chronic ACL injuries, less residual pivot shift (9.1 vs. 35.3%, p = 0.011), and better IKDC (92.7 ± 5.9 vs. 87.1 ± 9.0, p = 0.0013) and Lysholm (95.4 ± 5.3 vs. 90.0 ± 7.1, p < 0.0001) scores, and no evidence of historical concerns. Combined ACLR + ALLR is associated with excellent clinical outcomes with no evidence of the adverse events that led to the historical widespread abandonment of other types of LEAP. Specifically, comparative series have demonstrated significant advantages of ALLR when compared against isolated ACLR with respect to reduced rates of ACL graft rupture, secondary meniscectomy, persistent instability, and significantly improved functional outcomes and improved return to sport metrics.
Influences of discharge modes and gas bubbling conditions on E. coli sterilization by pulsed underwater discharge treatments
Authors: Li Yuan , Wen Jia-Ye , Jiang Qiu-Yu , Zhao Ling-Yu , Zhang Guan-Jun
Published: February 2020

Underwater discharges are considered to be promising solutions to water disinfection problems. In this paper, the sterilization effects of different discharge modes and gas bubbling conditions on E. coli are investigated. The experimental results show that spark discharge owns a much higher sterilization efficiency than the streamer discharge. The larger discharge volume and stronger UV emission during spark discharge may play a more important role than the electric field and active species in the sterilization efficiency of discharge modes. To further increase the sterilization efficiency, two kinds of feeding gases, O2 and Ar, are introduced in underwater discharges, and experimental results show that O2 bubbling presents a greater promotion than Ar. Higher sterilization efficiency of O2 bubbling than that of Ar can be explained by the combination of physical and chemical reactions, while in the case of Ar, only physical interactions play a major role.
Axisymmetric simulations of vertical displacement events in tokamaks: A benchmark of M3D-C1, NIMROD, and JOREK
Authors: Krebs I. , Artola F. J. , Sovinec C. R. , Jardin S. C. , Bunkers K. J. , Hoelzl M. , Ferraro N. M.
Published: February 2020

A benchmark exercise for the modeling of vertical displacement events (VDEs) is presented and applied to the 3D nonlinear magnetohydrodynamic codes M3D-C1, JOREK, and NIMROD. The simulations are based on a vertically unstable NSTX equilibrium enclosed by an axisymmetric resistive wall with a rectangular cross section. A linear dependence of the linear VDE growth rates on the resistivity of the wall is recovered for sufficiently large wall conductivity and small temperatures in the open field line region. The benchmark results show good agreement between the VDE growth rates obtained from linear NIMROD and M3D-C1 simulations and from the linear phase of axisymmetric nonlinear JOREK, NIMROD, and M3D-C1 simulations. Axisymmetric nonlinear simulations of a full VDE performed with the three codes are compared, and an excellent agreement is found regarding the plasma location and plasma currents, as well as eddy and halo currents in the wall.
Anti-reflection coatings of zero-index metamaterial for solar cells
Authors: Kamran Muhammad , Faryad Muhammad
Published: February 2020

Anti-reflection coatings of zero index metamaterials (ZIMs) are proposed for maximum absorption of light in solar cells. A thin layer of a ZIM is shown to help trap light inside a solar cell. The outer surface of a ZIM layer is planar, and the inner surface has periodic corrugations in order for the incident light to pass through but block the re-transmission of the light back into free space. Using rigorous calculations for light absorption efficiency integrated over the AM1.5 solar spectrum, the basic design of the anti-reflection coating using a ZIM is studied by comparing the results with a common anti-reflection coating and a ZIM layer planar on both sides.
An experimental investigation of temperature distribution and heat loss in molten salt tanks in concentrating solar power plants
Authors: Zhou Hao , Shi Hua , Zhu Yifan , Fang Wenfeng
Published: February 2020

Two-tank molten salt storage systems, which increase the dispatchability of power, are widely utilized in commercial concentrating solar power plants. In the present work, a pilot solar thermal power plant was created to investigate temperature distribution and heat loss in the molten salt tank. The results showed that the molten salt had no temperature stratification at different liquid levels and operating temperature conditions except at the unprotected position near the electric heater. However, there was an obvious temperature difference in the upper atmosphere: the temperature dropped by 5.5 °C to 6.5 °C with every 400 mm increase in the height. During the cooling process, the temperature gradient in the tank foundation was basically stable. Experiments indicated that the liquid level of the salt affected the cooling rate of the molten salt significantly, while it had a little effect on the total heat loss in the tank. As the liquid level decreased from 2040 to 1039 mm, the temperature difference of the molten salt in the cooling process increased from 22.1 °C to 41.5 °C, but the total heat loss only changed by 4.3%. However, the molten salt operating temperature had a great influence on both the temperature change and the heat loss in the molten salt tank. When the operating temperature decreased from 557.7 °C to 376.9 °C, the temperature difference of molten salt in the cooling process decreased from 37.4 °C to 19.7 °C and the total heat loss in the tank decreased by 48.2%.
Interaction features of two ultra-intense laser pulses self-trapped in underdense plasmas
Authors: Bai R. X. , Zhou C. T. , Huang T. W. , Ju L. B. , Wu S. Z. , Zhang H. , Yu M. Y. , Qiao B. , Ruan S. C. , He X. T.
Published: February 2020

The interaction of two parallel relativistic laser beams in underdense plasmas is investigated by considering the evolution of their wave envelopes. The energy transfer between the two lasers is given by an expression based on the evolution of the total laser power in a regime without beam mixing. It is shown that how the energy is transferred depends nonlinearly on the initial phase difference of the lasers, and the result of the interaction depends on the laser intensity, spot radius, and their separation distance. The results are verified by direct numerical solution of the relativistic nonlinear Schrödinger equations for the laser envelopes as well as particle-in-cell simulation. The study and results should be helpful for understanding the energy transfer behavior of multiple co-propagating laser beams in underdense plasmas.
Construction and test of an ion-gate with high-voltage switch system for single-reflection time of flight measurement
Authors: Kim Jongwon
Published: February 2020

An ion gate and its high-voltage pulse switch system are constructed to produce a few nanosecond pulse beam so that the beam can be used for the time of flight (TOF) measurement. The maximum gating voltages are set to be ±1 kV to deflect away ion beams of intermediate heavy nuclei such as 133Cs when the gate is closed. The ion gate was designed by calculating deflection angles analytically and was checked numerically, which were in agreement. On the other hand, the switch system uses a Behlke switch, solid-state high voltage device, for pulse gating and its circuit was designed utilizing an equivalent circuit of the gate. Simulation by LTspice showed that a 10 ns pulse with a peak voltage of 2 kV can be produced if the capacitance of the gate is less than 50 nF. The ion gate was first tested inside the TOF system to ensure that a Cs1+ beam can be turned on and off in terms of beam arriving at a Faraday cup. The switch was then tested in connection with the gate, and we found that the pulse can be produced and its peak can be controlled by adjusting the capacitance of connection cables so far as its width is kept.
Investigation of N2 adsorption on Fe3O4(001) using ambient pressure X-ray photoelectron spectroscopy and density functional theory
Authors: Degaga Gemechis D. , Trought Mikhail , Nemsak Slavomir , Crumlin Ethan J. , Seel Max , Pandey Ravindra , Perrine Kathryn A.
Published: February 2020

Reactions on iron oxide surfaces are prevalent in various chemical processes from heterogeneous catalysts to minerals. Nitrogen (N2) is known to dissociate on iron surfaces, a precursor for ammonia production in the Haber–Bosch process, where the dissociation of N2 is the limiting step in the reaction under equilibrium conditions. However, little is known about N2 adsorption on other iron-based materials, such as iron oxide surfaces that are ubiquitous in soils, steel pipelines, and other industrial materials. An atomistic description is reported for the binding of N2 on the Fe3O4(001) surface using first principles calculations with ambient pressure X-ray photoelectron spectroscopy. Two primary adsorption sites are experimentally identified from N2 dissociation on Fe3O4(001). The electronic signatures associated with the valence band region unambiguously show how the electronic structure of magnetite transforms near ambient pressures due to the binding of atomic nitrogen to different surface sites. Overall, the experimental and theoretical results of our study bridge the gap between ultra-high vacuum studies and reaction conditions to provide insight into other nitrogen-based chemistry on iron oxide surfaces that impact the agriculture and energy industries.
Structural studies of magnetic C60/Cu multilayers
Authors: Shoup J. E. , Arena D. A. , Borchers J. A. , Kirby B. J. , Caruana A. J. , Kinane C. J. , Langridge S. , Rogers M. , Cespedes O.
Published: February 2020

We report on x-ray and neutron scattering studies that reveal the structure of interfaces of C60 layers with adjacent transition metal layers, in this instance, Cu. Such interfaces produce room-temperature long-range spin order that is not described by conventional theories of metallic magnetism. We use a combination of hard x-ray reflectivity and neutron scattering to investigate the interfacial structure of two C60/Cu layered samples: a superlattice with multiple C60/Cu repeats and a simpler tri-layer structure. For both structures, we develop a consistent structural model for the two scattering techniques, which details the critical interfacial roughness between the layers. We find that while x-ray reflectivity provides a strong contrast between the C60 and Cu layers, the similar neutron scattering length density of the two materials severely reduces the neutron scattering contrast. Our results can be used to design material systems that permit studies of the magnetism of the C60/transition metal interfaces with spin-sensitive scattering probes such as polarized neutron reflectometry.
Tunable surface acoustic waves on strain-engineered relaxor K0.7Na0.3NbO3 thin films
Authors: Liang Sijia , Pfützenreuter D. , Finck D. , von Helden L. , Schwarzkopf J. , Wördenweber R.
Published: February 2020

In this work, we demonstrate the electronic tunability of surface acoustic waves (SAWs) in epitaxially strained relaxor-type ferroelectric thin films. Epitaxial K0.7Na0.3NbO3 thin films of typically 30 nm in thickness are grown via pulsed laser deposition on (110)-oriented TbScO3. A partial plastic lattice relaxation of the epitaxial strain in these samples leads to a relaxor-type ferroelectricity of these films, which strongly affects the SAW properties. Without electronic bias, only tiny SAW signals of ∼0.2 dB can be detected at room temperature, which can be boosted up to ∼4 dB by a static voltage bias added to the high frequency driving current of the SAW transducers. Upon field cooling below the freezing temperature of polar nanoregions (PNRs), this strong SAW signal can be preserved and is even enhanced due to a release of the electronically fixed PNRs if the bias is removed. In contrast, at elevated temperatures, a reversible switching of the SAW signal is possible. The switching shows relaxation dynamics that are typical for relaxor ferroelectrics. The relaxation time τ decreases exponentially from several hours at freezing temperature to a few seconds (<5 s) at room temperature.
A 5 GHz and 7.5 V multi-amplitude modulator driving circuit for practical high-speed quantum key distribution
Authors: Liu Xiang , Huang Ming-Qi , Min Hao , Jin Ge , Jiang Xiao , Peng Cheng-Zhi
Published: February 2020

Quantum key distribution (QKD) offers the ability of information theoretic security key exchange. The secure key rate is an important indicator for the practical QKD systems, which determines what kinds of applications can be supported. One most effective way to enhance the secure key rate is to increase the system repetition frequency. Here, we report an implementation of a high-speed DC-coupled modulator driving circuit with a repetition rate of up to 5 GHz. The circuit outputs a multi-amplitude return-to-zero pattern pulse with a maximum amplitude of 7.5 V. The design adapts to the various electro-optic modulators widely employed in QKD systems. The minimum pulse width is measured as 75 ps, with the relative noise level less than 1.5% for all the output amplitudes under random modulation.
Nutrient use efficiency and utilisation in east coast Australian Eucalyptus forests
Authors: Turner John
Published: February 2020

Nutrient use efficiency (NUE) has been used as a method to evaluate the utilisation and processes of cycling of nutrient in forests. In publications, different methods have been used to calculate NUE, but as efficiency they are all expressed as ratios and these cover the basic areas of: (1) absorption from the soil and uptake, (2) efficiency in their requirement or utilisation of nutrients including physiological efficiency and (3) efficiency in the retention and internal re-utilisation of nutrients. Few studies address NUE based on complete nutrient cycling information but use indices based on litterfall or foliage nutrient concentrations. In this study different expressions of NUE were defined and evaluated for N and P using data on nutrient cycles on species in the genus Eucalyptus in regrowth and mature native eastern Australian forests. It has been hypothesised that NUE increases with decreasing nutrient availability however increasing such efficiency has a cost reflected in reduced productivity. The hypothesis was proven for all expressions of NUE correlating NUE against estimates of soil N or P availability but there were differences between coastal and tableland Eucalyptus forests. The level of significance varied for different types of NUE and in these ecosystems P was of greater significance than N. This reflected the importance of P in relation to productivity on many of the weathered soils or the limited value of the soil available N indices. It is suggested that the difference expressions of NUE differ in their significance with species so some will be relatively more efficient in terms of uptake, others in utilisation and others in redistribution. Only in extreme situations of nutrient availability do species have relatively high efficiency for all methods NUE calculation. It is proposed that these differences are of importance in site/species distribution and more importantly in mixed stands where they provide advantages either at different stages of stand development or after significant disturbances such as fire.
Rutin content in the forage and grain of common buckwheat (Fagopyrum esculentum) as affected by sowing time and irrigation in a Mediterranean environment
Authors: Mariotti Marco , Macchia Marco , Cerri Domenico , Gatta Domenico , Arduini Iduna , Saccomanni Giuseppe
Published: February 2020

Cultivation of buckwheat (Fagopyrum esculentum Moench) under Mediterranean photothermal conditions could affect synthesis of the flavonoid rutin and its partitioning within the plant, thus affecting the nutraceutical value of plant products. We examined rutin concentration and yield in the forage and the grain of common buckwheat grown under Mediterranean field conditions, in response to sowing time, irrigation, growth stage at harvest, and variety. The highest rutin concentration and yield in the forage were obtained with late spring sowing, thanks to greater accumulation of solar radiation and higher efficiency of rutin synthesis per photothermal unit. Water supply promoted a more efficient use of light resources for both biomass accumulation and rutin synthesis. Rainfed conditions reduced biomass accumulation to a greater extent than rutin synthesis. Rutin concentration was highest in leaves, followed by inflorescences, stems and achenes, and in all plant parts it decreased with plant age. In the grain, rutin concentration was highest with late spring sowing, and rutin yield was highest with early spring sowing. Correlation analyses suggest that rutin synthesis proceeds from the leaves to the other plant parts. Our research demonstrates that buckwheat can be cultivated in Mediterranean regions as a source of rutin for medicine and for food and feed supplementation.
The forage grass Paspalum dilatatum tolerates partial but not complete submergence caused by either deep water or repeated defoliation
Authors: Manzur M. E. , Grimoldi A. A. , Striker G. G.
Published: February 2020

Grazing, flooding and their combination are major disturbances that could affect plant performance in humid grasslands. We performed two experiments to study the tolerance of the forage grass Paspalum dilatatum Poir. to different submergence depths and defoliation frequencies. First, we addressed whether this species can shift from the escape strategy to ‘quiescence’ when completely submerged for 30 days. Second, we explored to what extent partial or complete submergence produced by defoliation compromises plant regrowth. The results showed that regardless of the depth of water at submergence, P. dilatatum always responded by attempting to expose its leaf area above water, by increasing the tiller angle and/or blade length (i.e. tiller height). Partially submerged plants showed a reduction in starch concentration (89%) but biomass was unaffected, whereas completely submerged plants did not survive. After one defoliation event, 77% of aerial biomass of partially submerged plants was removed and the concentration of carbon reserves (water-soluble carbohydrates and starch) decreased to half that of control plants. A second event of defoliation (20 days later) of plants with few reserves removed 50–52% of shoot biomass and compromised plant survival, with plants dying before the end of the experiment. In conclusion, P. dilatatum does not tolerate prolonged conditions of complete submergence caused by either deep water columns or repeated defoliation.
John Dallachy (1804–71): collecting botanical specimens at Rockingham Bay
Authors: Dowe John Leslie , Maroske Sara
Published: February 2020

Warning Readers of this article are warned that it may contain terms, descriptions and opinions that are culturally sensitive and/or offensive to Aboriginal and Torres Strait Islanders. John Dallachy (1804–71) was employed by Baron Ferdinand von Mueller to collect plants as a pioneer resident of Cardwell, Rockingham Bay, Queensland, 1864–71. Mueller’s longest-serving paid botanical collector, Dallachy was also the most prolific collector of types among Mueller’s large network of collectors. In part, Dallachy’s success can be attributed to his collecting methods and intensive travels around the species-rich Rockingham Bay area. In part, also, Dallachy was indebted to fellow European pioneers for support (which was acknowledged in the eponymy of new taxa), and to local Indigenous and South Sea Islander people. Dallachy managed these relationships in a context of frontier war as local Indigenous people resisted being displaced by European colonists. Nevertheless, Dallachy’s opportunity to work as a full-time professional botanical collector, and the rapidity with which his new specimens were identified and published was, to a large extent, due to Mueller. The partnership with Mueller led to Dallachy contributing ~3500 specimens from Rockingham Bay to the Melbourne Herbarium of which ~400 taxa were considered new to Western science.
Effects of the environmental endocrine disruptors di-2-ethylhexyl phthalate and mono-2-ethylhexyl phthalate on human sperm function in vitro
Authors: Sun Xinyi , Chen Wenqiong , Weng Shiqi , Pan Tingting , Hu Xiaonian , Wang Fang , Xia Tianxinyu , Chen Houyang , Luo Tao
Published: February 2020

Di-2-ethylhexyl phthalate (DEHP), a plastic-derived, endocrine-disrupting chemical, has been shown to exhibit male reproductive toxicity. However, its effects on human mature spermatozoa are largely unknown. In this study we investigated the invitro effects of DEHP and mono-2-ethylhexyl phthalate (MEHP; the main metabolite of DEHP) on sperm function and the mechanisms involved. Human spermatozoa were exposed to phthalates invitro at the doses that cover the concentrations detected in human semen: 20nM–8 μM DEHP, 1nM–20 μM MEHP or a mixture of 20nM–8 μM DEHP and 1nM–20 μM MEHP. DEHP and MEHP, alone or in combination, had no effect on the viability, membrane integrity, motility, homeostasis of reactive oxygen species or mitochondrial activity of human spermatozoa. Interestingly, 1nM–20 μM MEHP and combinations of 20nM–8 μM DEHP and 1nM–20 μM MEHP enhanced penetration ability, hyperactivation and the spontaneous acrosome reaction of human spermatozoa, and increased intracellular free Ca2+ concentrations ([Ca2+]i) and tyrosine phosphorylation, two key signalling pathways that regulate sperm function. The findings of this study suggest that invitro exposure to MEHP metabolised from DEHP affects human sperm function by inducing increases in sperm [Ca2+]i and tyrosine phosphorylation, which adds to our understanding of the effects of DEHP on male reproduction.
Disturbance history modulates how litter and herbaceous cover influence conifer regeneration after fire
Authors: Gill Nathan S. , Jarvis Daniel , Rogan John , Kulakowski Dominik
Published: February 2020

Climate-driven increases in disturbance frequency and extent augment the potential for compounded disturbances. Drawing on well-studied forests that experienced successive disturbances, we asked: (1) how does post-fire cover of litter, herbaceous cover and bare ground vary between stands affected by combinations of blow-down, insect outbreak, and fire? (2) How do post-fire relationships between ground cover and conifer regeneration vary with recent disturbance history? We measured ground cover and conifer regeneration from 2003 to 2014 following stand-replacing fires in 2002. Burned stands were either blown down in 1997, affected by a 1940s Dendroctonus rufipennis (spruce beetle; SB) outbreak, or neither. Implementing mixed-effects models, we measured the relationships between pre-fire stand attributes (structural stage, canopy dominance and combination of disturbances) and post-fire ground cover and between post-fire ground cover and conifer regeneration. Fire-only stands had more litter and herbaceous cover post fire than other stands (P<0.05). Fir regeneration increased with litter in stands that only burned, but decreased with litter in stands that were first blown down. Similarly, pine and fir regeneration increased with herbaceous cover after fire-only, but did the opposite in stands affected by the SB outbreak. Pre-fire legacies can modulate the effects of ground cover on plant regeneration.
The effect of fuel bed height in grass fire spread: addressing the findings and recommendations of Moinuddin et al. (2018)
Authors: Cruz Miguel G. , Sullivan Andrew L. , Gould James S.
Published: February 2020

A recent numerical simulation study by Moinuddin et al. (2018) determined that over a specific range of Froude numbers defined by them as ‘plume mode’, grass fuel height has a strong inverse effect on the rate of fire spread in grasslands. They then suggested that a relationship for effect of fuel height derived from their simulation results could be used to support fire management decision-making. The present analysis used fire spread measurement data from two outdoor experimental burning studies in grass fuels where an explicit control of fuel height was imposed to verify the realism of their results. It was found that a reduction in grass height, with or without removal of the cut fuel and regardless of the Froude number, led to a significant reduction in rate of fire spread, a result opposite to the simulations obtained by Moinuddin et al. (2018).
Elongation factor-Tu can repetitively engage aminoacyl-tRNA within the ribosome during the proofreading stage of tRNA selection
Authors: Morse Justin C. , Girodat Dylan , Burnett Benjamin J. , Holm Mikael , Altman Roger B. , Sanbonmatsu Karissa Y. , Wieden Hans-Joachim , Blanchard Scott C.
Published: February 2020

Significance

Elongation factor Tu (EF-Tu) facilitates rapid and accurate selection of aminoacyl-tRNA (aa-tRNA) by the bacterial ribosome during protein synthesis. We show that EF-Tu dissociates from the ribosome as aa-tRNA navigates the accommodation corridor en route to peptide bond formation. We find that EF-Tu’s release from the ribosome during aa-tRNA selection can be reversible. We also demonstrate that new ternary complex formation, accompanied by futile cycles of GTP hydrolysis, can occur on aa-tRNA bound within the ribosome. These findings inform on the decoding mechanism, the contributions of EF-Tu to the fidelity of translation, and the potential consequences of reduced rates of peptide bond formation on cellular physiology.
High-Reynolds-number fractal signature of nascent turbulence during transition
Authors: Wu Zhao , Zaki Tamer A. , Meneveau Charles
Published: February 2020

Significance

Transition from laminar to turbulent flow over a solid surface is often accompanied by growth and merger of turbulent spots. Our analysis shows that these spots’ boundaries exhibit power-law scaling already during early phases of transition at very moderate Reynolds numbers. The measured fractal dimension,

D
=
2.36
±
0.03

, is visible over almost 5 decades and agrees very well with values known from fully turbulent flows, such as for cloud boundaries at much higher Reynolds numbers. Hence, turbulent spots at very moderate Reynolds numbers already contain seeds of high-Reynolds-number geometric scaling behavior. Since analytical tools are typically more easily applicable at low Reynolds numbers, turbulent spots could serve as a convenient setting for developing analytical tools aiming to predict high-Reynolds-number scaling laws in turbulence.
Positive allosteric modulation of indoleamine 2,3-dioxygenase 1 restrains neuroinflammation
Authors: Mondanelli Giada , Coletti Alice , Greco Francesco Antonio , Pallotta Maria Teresa , Orabona Ciriana , Iacono Alberta , Belladonna Maria Laura , Albini Elisa , Panfili Eleonora , Fallarino Francesca , Gargaro Marco , Manni Giorgia , Matino Davide , Carvalho Agostinho , Cunha Cristina , Maciel Patricia , Di Filippo Massimiliano , Gaetani Lorenzo , Bianchi Roberta , Vacca Carmine , Iamandii Ioana Maria , Proietti Elisa , Boscia Francesca , Annunziato Lucio , Peppelenbosch Maikel , Puccetti Paolo , Calabresi Paolo , Macchiarulo Antonio , Santambrogio Laura , Volpi Claudia , Grohmann Ursula
Published: February 2020

Significance

Indoleamine 2,3-dioxygenase 1 (IDO1) is an immunoregulatory enzyme that transforms tryptophan into kynurenine, an endogenous agonist of the aryl hydrocarbon receptor (AhR) whose activation sustains IDO1 expression and activity over the long term in dendritic cells (DCs). Here we found that
N
-acetylserotonin (NAS), a tryptophan metabolite produced along the serotonin pathway, acts as a positive allosteric modulator (PAM) of IDO1 and thus increases kynurenine-mediated AhR activation in DCs. NAS effects on IDO1 translated into protection of mice from neuroinflammation and reinstallment of physiologic IDO1 activity in peripheral blood mononuclear cells from patients with relapsing-remitting multiple sclerosis.
Give constructions in Korean EFL learner
writing
Authors: Nam Yunjung
Published: February 2020

This study aims to investigate constructions of
the verb give used by Korean EFL learners, along
with an in-depth analysis of ditransitive use and L1 influences. The
use of give in a Korean EFL learner corpus and a
reference native speaker corpus is analyzed in terms of different
construction types and their frequencies. In-depth analysis of
ditransitive use of give was conducted using three
factors: pronominality, weight, and semantic classes. L1 influence
was discussed and a Korean language corpus was used to provide
evidence to strengthen the arguments. This study concludes with the
discussion of limitations, and future directions for understanding
Korean EFL learners’ developmental trajectory of construction
acquisition within the usage-based framework.
Lexical bundles across disciplines
Authors: Reppen Randi , Olson Shannon B.
Published: February 2020

This chapter reports on a study that examined
over 700 four-word lexical bundles (Biber et al., 1999) identified from a
multi-disciplinary corpus of over 25 million words from introductory
courses across nine disciplines. Two types of bundles were
identified: cross-disciplinary (occurring in at least four of the
nine disciplines), and discipline-specific (occurring in only one or
two disciplines). Results indicate that these bundle types typically
serve different functions. The cross-disciplinary bundles function
as discourse frames providing sign posts for readers, while
discipline-specific bundles are often content-specific. Analyses
also identified bundles with variable slots that could be completed
with various fillers. The chapter concludes with ideas and examples
for teaching lexical bundles that can enhance teaching and promote
fluency for learners.