bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of bandwidth‐enhanced power amplifier based on class‐EF modes
Authors: Xuan Xuefei , Liu Yueyue , Zhai Muyi , Wang Yang , Ge Xianlei , Liu Guohua , Cheng Zhiqun 
Published: April 2021

AbstractThis article describes a methodology for designing broadband high‐efficiency GaN HEMT power amplifier (PA) which is suitable for base stations and modern wireless communication based on the Class‐EF mode. To achieve both efficiency enhancement and bandwidth extension for the PA, the load‐pull technique is employed to acquire the optimum impedance regions of the second harmonic. Especially, considering the influences of the harmonic control network on the accuracy of obtaining the fundamental impedance, the load‐pull technique is performed to obtain the optimal fundamental impedance again after the harmonic control circuit is determined. In addition, the theory of multiple frequencies matching is also employed to manipulate six desired fundamental frequency points concurrently. Based on the proposed theory, the Class‐EF PA prototype is designed and fabricated. The measurement results exhibits a drain efficiency (DE) of 60%–75% in the range of 2.1–3.6 GHz while having an output power of 38–40.5 dBm and gain of larger than 8 dB.
High spatial resolution imaging of the dynamics of cuticular lipid deposition during Arabidopsis flower development
Authors: Alexander Liza E. , Gilbertson Jena S. , Xie Bo , Song Zhihong , Nikolau Basil J. 
Published: April 2021

AbstractThe extensive collection of glossy (gl) and eceriferum (cer) mutants of maize and Arabidopsis have proven invaluable in dissecting the branched metabolic pathways that support cuticular lipid deposition. This bifurcated pathway integrates a fatty acid elongation‐decarbonylative branch and a fatty acid elongation‐reductive branch, which collectively has the capacity to generate hundreds of cuticular lipid metabolites. In this study, a combined transgenic and biochemical strategy was implemented to explore and compare the physiological function of three homologous genes, Gl2, Gl2‐like, and CER2, in the context of this branched pathway. These biochemical characterizations integrated new extraction chromatographic procedures with high spatial resolution mass spectrometric imaging methods to profile the cuticular lipids on developing floral tissues transgenically expressing these transgenes in wild‐type or cer2 mutant lines of Arabidopsis. Collectively, these datasets establish that both the maize Gl2 and Gl2‐like genes are functional homologs of the Arabidopsis CER2 gene. In addition, the dynamic distribution of cuticular lipid deposition follows distinct floral organ localization patterns indicating that the fatty acid elongation‐decarbonylative branch of the pathway is differentially localized from the fatty acid elongation‐reductive branch of the pathway.
Exploring charm decays with missing energy in leptoquark models
Authors: Faisel Gaber , Su Jhih-Ying , Tandean Jusak 
Published: April 2021

Abstract
We investigate the possibility that scalar leptoquarks generate consequential effects on the flavor-changing neutral-current decays of charmed hadrons into final states with missing energy "Image missing" carried away by either standard model or sterile neutrinos. We focus on scenarios involving the R2, $$ {\tilde{R}}_2 $$

R
˜

2

, and $$ {\overline{S}}_1 $$

S
¯

1

leptoquarks and take into account various pertinent constraints, learning that meson-mixing ones and those inferred from collider searches can be of significance. We find in particular that the branching fractions of charmed meson decays D →"Image missing", M = π, ρ, and Ds→"Image missing" and singly charmed baryon decays $$ {\Lambda}_c^{+} $$

Λ
c
+

→"Image missing" and Ξc→"Image missing" are presently allowed to attain the 10−7-10−6 levels if induced by R2 and that the impact of $$ {\tilde{R}}_2 $$

R
˜

2

is comparatively much less. In contrast, the contributions of $$ {\overline{S}}_1 $$

S
¯

1

, which couples to right-handed up-type quarks and the sterile neutrinos, could lead to branching fractions as high as order 10−3. This suggests that these charmed hadron decays might be within reach of the BESIII and Belle II experiments or future super charm-tau factories and could serve as potentially promising probes of leptoquark interactions with sterile neutrinos.
Accessing large global charge via the ϵ-expansion
Authors: Watanabe Masataka 
Published: April 2021

Abstract
We compute the lowest operator dimension ∆(J; D) at large global charge J in the O(2) Wilson-Fisher model in D = 4 − ϵ dimensions, to leading order in both 1/J and ϵ. While the effective field theory approach of [1] could only determine ∆(J; 3) as a series expansion in 1/J up to an undetermined constant in front of each term, this time we try to determine the coefficient in front of J3/2 in the ϵ-expansion. The final result for ∆(J; D) in the (resummed) ϵ-expansion, valid when J ≫ 1/ϵ ≫ 1, turns out to be$$ \Delta \left(J;D\right)=\left[\frac{2\left(D-1\right)}{3\left(D-2\right)}{\left(\frac{9\left(D-2\right)\pi }{5D}\right)}^{\frac{D}{2\left(D-1\right)}}{\left[\frac{5\Gamma \left(\frac{D}{2}\right)}{24{\pi}^2}\right]}^{\frac{1}{D-1}}{\epsilon}^{\frac{D-1}{2\left(D-1\right)}}\right]\times {J}^{\frac{D}{D-1}}+O\left({J}^{\frac{D-2}{D-1}}\right) $$
Δ

J
D

=

2

D
−
1

3

D
−
2

9

D
−
2

π

5
D

D

2

D
−
1

5
Γ

D
2

24

π
2

1

D
−
1

ϵ

D
−
1

2

D
−
1

×

J

D

D
−
1

+
O

J

D
−
2

D
−
1

where next-to-leading order onwards were not computed here due to technical cumbersomeness, despite there are no fundamental difficulties. We also compare the result at ϵ = 1,$$ \Delta (J)=0.293\times {J}^{3/2}+\cdots $$
Δ

J

=
0.293
×

J

3
/
2

+
⋯
to the actual data from the Monte-Carlo simulation in three dimensions [2], and the discrepancy of the coefficient 0.293 from the numerics turned out to be 13%. Additionally, we also find a crossover of ∆(J; D) from ∆(J) ∝ $$ {J}^{\frac{D}{D-1}} $$

J

D

D
−
1

to ∆(J) ∝ J, at around J ∼ 1/ϵ, as one decreases J while fixing ϵ (or vice versa), reflecting the fact that there are no interacting fixed-point at ϵ = 0. Based on this behaviour, we propose an interesting double-scaling limit which fixes λ ≡ Jϵ, suitable for probing the region of the crossover. I will give ∆(J; D) to next-to-leading order in perturbation theory, either in 1/λ or in λ, valid when λ ≫ 1 and λ ≪ 1, respectively.
Observations of Hawking radiation: the Page curve and baby universes
Authors: Marolf Donald , Maxfield Henry 
Published: April 2021

Abstract
We reformulate recent insights into black hole information in a manner emphasizing operationally-defined notions of entropy, Lorentz-signature descriptions, and asymptotically flat spacetimes. With the help of replica wormholes, we find that experiments of asymptotic observers are consistent with black holes as unitary quantum systems, with density of states given by the Bekenstein-Hawking formula. However, this comes at the cost of superselection sectors associated with the state of baby universes. Spacetimes studied by Polchinski and Strominger in 1994 provide a simple illustration of the associated concepts and techniques, and we argue them to be a natural late-time extrapolation of replica wormholes. The work aims to be self-contained and, in particular, to be accessible to readers who have not yet mastered earlier formulations of the ideas above.
Diagrammatic expansion of non-perturbative little string free energies
Authors: Hohenegger Stefan 
Published: April 2021

Abstract
In [1] we have studied the single-particle free energy of a class of Little String Theories of A-type, which are engineered by N parallel M5-branes on a circle. To leading instanton order (from the perspective of the low energy U(N) gauge theory) and partially also to higher order, a decomposition was observed, which resembles a Feynman diagrammatic expansion: external states are given by expansion coefficients of the N = 1 BPS free energy and a quasi-Jacobi form that governs the BPS-counting of an M5-brane coupling to two M2-branes. The effective coupling functions were written as infinite series and similarities to modular graph functions were remarked. In the current work we continue and extend this study: working with the full non-perturbative BPS free energy, we analyse in detail the cases N = 2, 3 and 4. We argue that in these cases to leading instanton order all coupling functions can be written as a simple combination of two-point functions of a single free scalar field on the torus. We provide closed form expressions, which we conjecture to hold for generic N. To higher instanton order, we observe that a decomposition of the free energy in terms of higher point functions with the same external states is still possible but a priori not unique. We nevertheless provide evidence that tentative coupling functions are still combinations of scalar Greens functions, which are decorated with derivatives or multiplied with holomorphic Eisenstein series. We interpret these decorations as corrections of the leading order effective couplings and in particular link the latter to dihedral graph functions with bivalent vertices, which suggests an interpretation in terms of disconnected graphs.
Pheromone Mediated Sexual Reproduction of Pennate Diatom Cylindrotheca closterium
Authors: Klapper Franziska , Audoor Sien , Vyverman Wim , Pohnert Georg 
Published: April 2021

AbstractBenthic diatoms dominate primary production in marine subtidal and intertidal environments. Their extraordinary species diversity and ecological success is thought to be linked with their predominantly heterothallic sexual reproduction. Little is known about pheromone involvement during mating of pennate diatoms. Here we describe pheromone guided mating in the coastal raphid diatom Cylindrotheca closterium. We show that the two mating types (mt+ and mt−) have distinct functions. Similar to other benthic diatoms, mt+ cells are searching for the mt− cells to pair. To enhance mating efficiency mt− exudes an attraction pheromone which we proved by establishing a novel capillary assay. Further, two more pheromones produced by mt− promote the sexual events. One arrests the cell cycle progression of mt+ while the other induces gametogenesis of mt+. We suggest that C. closterium shares a functionally similar pheromone system with other pennate diatoms like Seminavis robusta and Pseudostaurosira trainorii which synchronize sexual events and mate attraction. Remarkably, we found no evidence of mt+ producing pheromones, which differentiates C. closterium from other pennates and suggests a less complex pheromone system in C. closterium.
High-order Combined Multi-step Scheme for Solving Forward Backward Stochastic Differential Equations
Authors: Teng Long , Zhao Weidong 
Published: April 2021

AbstractIn this work, in order to obtain higher-order schemes for solving forward backward stochastic differential equations, we propose a new multi-step scheme by adopting the high-order multi-step method in Zhao et al. (SIAM J. Sci. Comput., 36(4): A1731-A1751, 2014) with the combination technique. Two reference ordinary differential equations containing the conditional expectations and their derivatives are derived from the backward component. These derivatives are approximated by using the finite difference methods with multi-step combinations. The resulting scheme is a semi-discretization in the temporal direction involving conditional expectations, which are solved by using the Gaussian quadrature rules and polynomial interpolations on the spatial grids. Our new proposed multi-step scheme allows for higher convergence rate up to ninth order, and are more efficient. Finally, we provide a numerical illustration of the convergence of the proposed method.
Policy learning as complex contagion: how social networks shape organizational beliefs in forest-based climate change mitigation
Authors: Gronow Antti , Brockhaus Maria , Di Gregorio Monica , Karimo Aasa , Ylä-Anttila Tuomas 
Published: April 2021

AbstractPolicy learning can alter the perceptions of both the seriousness and the causes of a policy problem, thus also altering the perceived need to do something about the problem. This then allows for the informed weighing of different policy options. Taking a social network perspective, we argue that the role of social influence as a driver of policy learning has been overlooked in the literature. Network research has shown that normatively laden belief change is likely to occur through complex contagion—a process in which an actor receives social reinforcement from more than one contact in its social network. We test the applicability of this idea to policy learning using node-level network regression models on a unique longitudinal policy network survey dataset concerning the Reducing Deforestation and Forest Degradation (REDD+) initiative in Brazil, Indonesia, and Vietnam. We find that network connections explain policy learning in Indonesia and Vietnam, where the policy subsystems are collaborative, but not in Brazil, where the level of conflict is higher and the subsystem is more established. The results suggest that policy learning is more likely to result from social influence and complex contagion in collaborative than in conflictual settings.
Hot or not? connecting rhizosphere hotspots to total soil respiration
Authors: Becker Joscha N. , Holz Maire 
Published: April 2021

Abstract
Aims
Soil organic carbon (C) efflux is tightly linked to the rhizosphere, where soil microorganisms rapidly decompose organic compounds released from roots. Recently, imaging approaches have greatly improved our understanding of small-scale C-turnover heterogeneity and promoted the term ‘rhizosphere hotspots’ for highly active areas. However, despite often assumed, the effect of these hotspots on total soil C balances is still unknown. We aim to bridge this gap by correlating rhizosphere imaging data to soil respiration on individual plant scale.

Methods
We grew 17 maize (Zea mays L.) plants in rhizoboxes filled with sandy arable soil. After four weeks, the plants were labelled with 14CO2 and root exudation was visualized and quantified by 14C-imaging one day after labeling. The evolved CO2 was trapped in NaOH and 14CO2 as well as total CO2 was quantified before and after labelling. Enzyme activity (β-glucosidase) was quantified by soil zymography.

Results
Bulk soil β-glucosidase activitiy negatively correlated to total CO2 efflux, and was the most important predictor (R2 = 0.55). Total and rhizosphere specific 14C-activity were solely correlated to 14CO2 efflux (r = 0.51, r = 0.58). A combination of bulk soil β-glucosidase activity, rhizosphere-14C activity and root biomass, explained about 75% of variance in CO2 efflux.

Conclusions
This indicates that root exudation and enzyme-activity hotspots are suitable predictors for total soil respiration, particularly when combined with root biomass to account for three-dimensional variation, and that hotspots on the rhizosphere scale are directly linked to larger scale C balances.
FABry Disease Patient-Reported Outcome-GastroIntestinal (FABPRO-GI): A new Fabry disease-specific gastrointestinal outcomes instrument
Authors: Shields Alan L. , Lamoureux Roger E. , Taylor Fiona , Barth Jay A. , Mulberg Andrew E. , Kessler Vivian , Skuban Nina 
Published: April 2021

Abstract
Purpose
Fabry disease is a rare multisystemic disorder caused by functional deficiency of the lysosomal enzyme alpha-galactosidase A. Gastrointestinal (GI) signs and symptoms are among the earliest clinical manifestations in patients with Fabry disease but are often nonspecific, misdiagnosed, and untreated. No instruments have been developed specifically to assess GI signs and symptoms in Fabry disease. The FABry disease Patient-Reported Outcome-GastroIntestinal (FABPRO-GI) was developed to address this unmet need and is intended for use in clinical trials (24-h FABPRO-GI) and real-world settings (7-day FABPRO-GI).

Methods
Findings from a literature review, expert advisory meetings, and patient concept elicitation interviews (CEIs) were summarized into conceptual models. These conceptual models were used to develop preliminary versions of the 24-h and 7-day FABPRO-GI. Cognitive debriefing interviews (CDIs) were conducted with additional patients to assess content validity, including understandability, relevance, and comprehensiveness of the preliminary versions of the 24-h and 7-day FABPRO-GI.

Results
Literature review (n = 17 articles), expert advisory meetings (n = 5), and patient CEIs (n = 17) identified mostly overlapping Fabry disease-related GI signs and symptoms, including abdominal cramps, bloating, and diarrhea, and informed development of the preliminary 24-h and 7-day FABPRO-GI. CDIs (n = 15) provided evidence of content validity and informed revisions of the 24-h and 7-day FABPRO-GI.

Conclusion
With evidence of content validity, the 24-h and 7-day FABPRO-GI are the first Fabry disease-specific patient-reported outcomes to assess GI signs and symptoms in patients with Fabry disease with potential for use in clinical trials and real-world settings, respectively.
Tor Relays an Universitäten
Authors: Döpmann Christoph , Marx Matthias , Federrath Hannes , Tschorsch Florian 
Published: April 2021

ZusammenfassungWährend Universitäten mit ihrer Infrastruktur und Kompetenz ideale Bedingungen für
den Betrieb von Tor-Knoten bieten, ist ihr Anteil am Tor-Netz erstaunlich gering. Wir berichten über
unsere Erfahrungen beim Betrieb von zwei Exit-Knoten an Universitäten und geben Empfehlungen für
deren Betrieb.
Three-dimensional guidance and control for ground moving target tracking by a quadrotor
Authors: Sepehri Movafegh M. , Dehghan S.M.M. , Zardashti R. 
Published: April 2021

Abstract
This paper develops a three-dimensional guidance and control algorithm to ensure that a manoeuverable target is preserved by a quadrotor in a long-term tracking scenario. The proposed guidance approach determines the desired altitude of the quadrotor to adjust the field of view (FOV) to the union of two desired trusted and critical regions. The dimensions of the desired trusted region depend on the controller performance that is evaluated by the distance of the target from the center of the FOV. The critical region is a predefined margin around the trusted region that is defined by the operator based on the upper bounds of the quadrotor and target localisation errors. It also depends on the duration and magnitude of the temporal increase in the target velocity compared to the quadrotor velocity. A sufficient condition is provided for the minimum desired altitude of the quadrotor to ensure that the target is maintained in the FOV. Furthermore, a model predictive control (MPC) is employed to preserve the target at the center of the aerial image and the desired altitude determined by the guidance law. Also, the integrals of the position errors are used to achieve null steady-state errors in the presence of wind disturbances. The simulation results show the effectiveness of the proposed approach in preserving the manoeuverable target in the FOV in the presence of the wind, the uncertainty of the target and quadrotor localisation, accelerations estimation errors, and terrain altitude variation.
Food sources of iodine in schoolchildren and relationship with 24-h urinary iodine excretion in Victoria, Australia
Authors: Beckford Kelsey , Grimes Carley A. , Riddell Lyann J. , Margerison Claire , Skeaff Sheila A. , Nowson Caryl A. 
Published: April 2021

AbstractDietary recalls have been used previously to identify food sources of iodine in Australian schoolchildren. Dietary assessment can provide information on the relative contributions of individual food groups which can be related to a robust objective measure of daily intake (24-h urinary iodine excretion (UIE)). In Australia, the government has mandated the use of iodised salt in breadmaking to address iodine deficiency. The aim of this study was to determine the dietary intake and food sources of iodine to assess their contribution to iodine excretion (UIE) in a sample of Australian schoolchildren. In 2011–2013, UIE was assessed using a single 24-h urine sample and dietary intake was assessed using one 24-h dietary recall in a convenience sample of primary schoolchildren from schools in Victoria, Australia. Of the 454 children with a valid recall and urine sample, 55 % were male (average age 10·1 (1·3 (sd) years). Mean UIE and dietary iodine intake were 108 (sd54) and 172 (sd74) μg/d, respectively. Dietary assessment indicated that bread and milk were the main food sources of iodine, contributing 27 and 25 %, respectively, to dietary iodine. Milk but not bread intake was positively associated with UIE. Multiple regression (adjusted for school cluster, age and sex) indicated that for every 100 g increase in milk consumption, there was a 3 μg/d increase in UIE (β =4·0 (se0·9),P< 0·001). In conclusion, both bread and milk were important contributors to dietary iodine intake; however, consumption of bread was not associated with daily iodine excretion in this group of Australian schoolchildren.
First freshwater gastropod preserved in amber suggests long-distance dispersal during the Cretaceous Period
Authors: Yu Tingting , Neubauer Thomas A. , Jochum Adrienne 
Published: April 2021

AbstractBurmese amber continues to provide unique insights into the terrestrial biota inhabiting tropical equatorial forests during mid-Cretaceous time. In contrast to the large amount and great diversity of terrestrial species retrieved so far, aquatic biota constitute rare inclusions. Here we describe the first freshwater snail ever preserved in amber. The new speciesGalba primasp. nov. belongs in the family Lymnaeidae, today a diverse and near globally distributed family. Its inclusion in terrestrial amber is probably a result of the amphibious lifestyle typical of modern representatives of the genus. The finding of a freshwater snail on the Burma Terrane, back then an island situated at some 1500 km from mainland Asia, has implications for the dispersal mechanisms of Mesozoic lymnaeids. The Cenomanian species precedes the evolution of waterfowl, which are today considered a main vector for long-distance dispersal. In their absence, we discuss several hypotheses to explain the disjunct occurrence of the new species.
New Opportunities for the Public to Shape the Nation's Institutional Health Care Services
Authors: Mandel Mark D. 
Published: April 2021

AbstractThe author of this Comment describes how recent federal legislation (P.L. 93-641, signed into law in January, 1975)—and improved scientific techniques for integrating (1) community medical needs assessment, (2) institutional budgeting linked to regional/state health plans, and (3) budget ceilings—have given the public new authority and technology to shape the nation's institutional health services. He urges administrators and trustees of health institutions—both proprietary and charitable—to become aware of recent developments in this area, and says that active consumer and provider participation in Health Systems Agencies and Statewide Coordinating Councils is necessary if the new federal expectations concerning health planning and regulation are to be met. Given the rising costs of medical care, stronger federal control might be forthcoming if the purposes of P.L. 93-641 are not achieved.