bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Radiotherapy in Locally Advanced, Fungating, and Inoperable Breast Cancer
Authors: Singh Pramod Kumar , Verma Jitendra Kumar , Raza Waseem , Verma Sanjay Kumar , Kumar Nitin
Published: February 2020

Introduction In India, majority of patients are diagnosed with breast cancer in locally advanced stage. Surgery, chemotherapy, and radiotherapy (RT) are the mainstay of treatment for many patients who are not fit for surgery and need local RT.

Materials and Methods This was a single-center, nonstratified, single-blind, nonplacebo-controlled parallel group intervention study with imbalanced randomization done at our institute. Adult patients of 30 to 65 years of age with histologically proven carcinoma of breast with biopsy were registered and assessed.

Results In total, 30 patients were included in the study and the mean age was 50 years. All the patients received 30 Gy/10 fractions in 2 weeks and the response was assessed after 4 weeks of completion of RT. Twelve patients observed more than 70% reduction in tumor size and good subjective relief, nine patients observed 40% reduction in tumor size, and six patients observed 30% reduction in tumor size. Two patients did not show any response to RT, while one patient did show progress. All patients received chemotherapy before RT and 28 patients received chemotherapy after RT.

Conclusion Thus, whether it is 20 Gy in 5 fractions or 30 Gy in 10 fractions is debatable and needs further study of larger group to establish their benefit on each other. However, 30 Gy in 10 fractions gives good subjective response to patients and improves the quality of life.
Diagnóstico da Doença Inflamatória Intestinal na Criança e Adolescente
Authors: Rodrigues Maraci
Published: February 2020

O critério de Porto1 esta alinhado com a apresentação do ESPGHAN, pois ambas as fontes chamam a atenção sobre o cuidado que se deve ter ao fazer diagnóstico da Doença Inflamatória Intestinal (DII) em crianças e adolescentes, mas principalmente em menores de 6 anos, no sentido de se afastar a possibilidade de imunodeficiências primárias e de doenças monogenéticas.

A apresentação do ESPGHAN reforça que é muito importante a forma de comunicação do diagnóstico para familiares e pacientes com DII pediátrica. O profissional deve, se possível, ter um time especializado em DII pediátrica, com pediatra, gastropediatra, enfermeira, nutricionista, psicóloga,etc.

A DII tem se tornado um diagnóstico crescente em crianças de todas as idades. Esta condição tem quadro clínico particular na infância, comparado com os adultos. Realizar o diagnóstico precoce é fundamental para se evitar um impacto adicional sobre o estado nutricional, desenvolvimento pondoestatural e pubertário.

Também requer atenção as consequências da DII sobre o aspecto psicossocial da criança e do adolescente, pois é comum a ruptura escolar e atividades sociais, especialmente naqueles pacientes com a doença instável ou grave, sendo necessário a intervenção psicológica.
Manejo da obesidade infanto-juvenil
Authors: de Mello Elza Daniel , Nogueira-de-Almeida Carlos Alberto
Published: February 2020

O assunto aqui abordado foi apresentado no Simpósio Paralelo: Manejo clínico da obesidade e da doença hepática não gordurosa do fígado na criança“, coordenado por: Anil Dhawan (UK) e Mary Fewtrell (UK). Estão sendo apresentados alguns aspectos salientados na apresentação de Cristina Campoy (Granada, Espanha), com o título “Manejo não cirúrgico da obesidade infantil“.
Esofagite eosinofílica na infância
Authors: Duarte Marco Antônio
Published: February 2020

A Esofagite eosinofílica (EEo) é doença imunológica caracterizada por 15 ou mais eosinófilos à biópsia microscópica da mucosa esofágica em campo de maior aumento. Acomete principalmente adultos (20% em crianças). As manifestações clínicas são vômitos, regurgitação, dificuldade para alimentar, dor abdominal e/ou retroesternal, disfagia ou impactação alimentar. Variam com a idade. Os primeiros são mais frequentes em crianças menores. O diagnóstico só deve ser considerado após exclusão de doença péptica com Inibidores de Bomba de Prótons (IBP). Há duas opções para o tratamento: Uso de corticoide tópico na mucosa esofágica dissolvido em solução viscosa durante pelo menos 8 semanas; exclusão de possíveis antígenos - leite de vaca, ovo, amendoim, soja, amidos, frutos do mar, castanha e/ou carnes. Os pacientes podem evoluir para a cura ou apresentar recidivas frequentes. Muitas pesquisas ainda são necessárias para melhor compreensão desta doença.
Impactos da microbiota intestinal na saúde do lactente e da criança em curto e longo prazo
Authors: Fernandes Tadeu Fernando
Published: February 2020

Base teórica: Há evidências suficientes que sustentam a importância da programação metabólica no período perinatal e nos primeiros anos de vida na prevenção ou desenvolvimento de doenças ao longo da vida.

Metodologia: Utilizando como referências principais as palestras proferidas no ESPGHAN 2016, fizemos uma revisão bibliográfica nas bases de dados PubMed, Scielo e Google Scholar, tendo como objetivo principal mostrar a importância dos impactos da microbiota intestinal na saúde do lactente e da criança em curto e longo prazo.

Achados: Documentou-se a existência de um imprinting epigenético fetal através da translocação bacteriana durante a gravidez, que fornece à prole um microbioma pioneiro intra-útero. A presença de componentes da microbiota materna no feto intra-útero é uma importante fonte de maturação do sistema imune fetal levando à indução de tolerância à alérgenos orais e respiratórios, mas pode também resultar em um desfavorável fator epigenético nos casos de obesidade materna.

Conclusão: Está clara e evidente a importância do pediatra no acompanhamento do desenvolvimento da microbiota intestinal da criança desde a vida intrauterina.

Existem várias janelas de oportunidade para intervenção na programação metabólica da criança visando minimizar as repercussões na saúde em curto e longo prazo.
Dynamics of a circular cylinder with an attached splitter plate in laminar flow: A transition from vortex-induced vibration to galloping
Authors: Sun Xu , Suh C. Steve , Ye Ze-Hua , Yu Bo
Published: February 2020

Flow-induced vibration (FIV) of a circular cylinder with an attached splitter plate in a laminar flow with Re = 100 is studied numerically. First, the mechanical model along with mathematical formulations is proposed to describe the fluid-structure interaction (FSI) between the elastically supported cylinder–plate body and the surrounding flow. Subsequently, an FSI solution procedure is developed based on the characteristic-based split finite element method, and its accuracy and stability are validated using vortex-induced vibrations (VIVs) of a plain circular cylinder with benchmark solutions. Finally, using FSI simulations, effects of the plate length (L), reduced velocity, mass ratio and damping coefficient on the dynamic response, fluid load, and flow pattern of the cylinder–plate assembly are investigated in detail. As the plate length increases from L/D = 0–1.5 (D is the cylinder diameter), three FIV modes are observed successively: VIV, coupled VIV and galloping, and separated VIV and galloping, along with three vortex modes in the wake: 2S (two separated vortices in one cycle), P+S (a vortex pair and a separated vortex in one cycle), and 2P (two vortex pairs in one cycle). Moreover, it is found that the lift components generated from the splitter plate and the cylinder behave, respectively, as the driving force and the suppressing force of galloping, and the transition from VIV to galloping can be taken as a result of the competition between them. The cylinder–plate model presented could be taken as a benchmark model demonstrating the VIV-galloping interaction and applied to the design of novel FSI-based energy harvesters.
Analytic stability boundaries for compressional and global Alfvén eigenmodes driven by fast ions. I. Interaction via ordinary and anomalous cyclotron resonances
Authors: Lestz J. B. , Gorelenkov N. N. , Belova E. V. , Tang S. X. , Crocker N. A.
Published: February 2020

Conditions for net fast ion drive are derived for beam-driven, sub-cyclotron compressional (CAE) and global (GAE) Alfvén eigenmodes, such as those routinely observed in spherical tokamaks such as NSTX(-U) and MAST. Both co- and counter-propagating CAEs and GAEs are investigated, driven by the ordinary and anomalous Doppler-shifted cyclotron resonance with fast ions. Whereas prior results were restricted to vanishingly narrow distributions in velocity space, broad parameter regimes are identified in this work which enable an analytic treatment for realistic fast ion distributions generated by neutral beam injection. The simple, approximate conditions derived in these regimes for beam distributions of realistic width compare well to the numerical evaluation of the full analytic expressions for fast ion drive. Moreover, previous results in the very narrow beam case are corrected and generalized to retain all terms in ω/ωci and |k∥/k⊥|, which are often assumed to be small parameters but can significantly modify the conditions of drive and damping when they are non-negligible. Favorable agreement is demonstrated between the approximate stability criterion, simulation results, and a large database of NSTX observations of cntr-GAEs.
Rapid discrimination of chemically distinctive surface terminations in 2D material based heterostructures by direct van der Waals identification
Authors: Tamalampudi Srinivasa Reddy , Santos Sergio , Lai Chia-Yun , Olukan Tuza A. , Lu Jin-You , Rajput Nitul , Chiesa Matteo
Published: February 2020

We demonstrate that surfaces presenting heterogeneous and atomically flat domains can be directly and rapidly discriminated via robust intensive quantifiables by exploiting one-pass noninvasive methods in standard atomic force microscopy (AFM), single ∼2 min passes, or direct force reconstruction, i.e., ∼103 force profiles (∼10 min collection time), allowing data collection, interpretation, and presentation in under 20 min, including experimental AFM preparation and excluding only sample fabrication, in situ and without extra experimental or time load. We employ a misfit SnTiS3 compound as a model system. Such heterostructures can be exploited as multifunctional surface systems and provide multiple support sites with distinguishable chemical, mechanical, or opto-electronic distinct properties. In short, they provide an ideal model system to exemplify how current AFM methods can significantly support material discovery across fields.
Electronic and optical properties of highly boron-doped epitaxial Ge/AlAs(001) heterostructures
Authors: Clavel Michael B. , Liu Jheng-Sin , Meeker Michael A. , Khodaparast Giti A. , Xie Yuantao , Heremans Jean J. , Bhattacharya Shuvodip , Hudait Mantu K.
Published: February 2020

The impact of elemental boron (B) doping on the structural, optical, and magnetotransport properties of epitaxial Ge/AlAs/GaAs(001) heterostructures, grown by solid-source molecular beam epitaxy, was comprehensively investigated. Cross-sectional transmission electron microscopy analysis revealed atomically abrupt Ge:B/AlAs and AlAs/GaAs heterointerfaces and a lack of observable long-range defect formation or B segregation in the epitaxial Ge:B layer. Spectral broadening observed in the measured temperature-dependent photoluminescence spectra suggested valence band mixing during recombination, implying a splitting of the valence band heavy- and light-hole degeneracy due to residual strain resulting from substitutional B incorporation in the Ge epilayer. Temperature-dependent magnetotransport analysis of the B-doped Ge thin films exhibited the tell-tale signature of antilocalization, indicating observable spin–orbit interaction in the Ge:B system. Moreover, the temperature- and magnetic field-dependent magnetotransport results indicate the presence of single-carrier, p-type conduction in the Ge:B film, further affirming the successful incorporation and activation of B at a high concentration (∼4 × 1019 cm−3) and elimination of parallel conduction via the large-bandgap AlAs buffer. Together, these results provide insights into the effects of heavy doping (via elemental solid-source doping) on Ge-based heterostructures and their feasibility in future electronic and photonic applications.
Non-classical electron transport in the cathode plume of a Hall effect thruster
Authors: Jorns Benjamin A. , Cusson Sarah E. , Brown Zachariah , Dale Ethan
Published: February 2020

An experimental investigation is presented into the wave-driven electron transport in the near-field plume of a hollow cathode operating in a 300 V, 4.5 kW magnetically shielded Hall thruster. Correlational analysis of probe measurements in the cathode plume shows two types of electrostatic waves: ion acoustic turbulence propagating along the applied longitudinal magnetic field at frequencies from 500 to 1250 kHz and coherent, azimuthal anti-drift waves with a fundamental frequency of 95 kHz and mode numbers from m=1−4. A quasilinear analysis is applied to quantify the impact of each wave on the electron transport in the near-field plume. It is found that the ion acoustic modes give rise to an enhanced effective collision frequency in the direction parallel to the applied magnetic field that exceeds the classical collision frequency by two orders of magnitude. The anti-drift waves promote an anisotropic collision frequency that depends on the direction of the electron drift. While the enhanced collision frequency from these waves is comparable to the classical frequency for motion along the applied magnetic field, the effective collision frequency in the azimuthal direction exceeds the classical by three orders of magnitude. These results are discussed in the context of their impact on the steady-state plasma gradients in the near-field cathode plume. Closure models for incorporating the effective collision frequencies from both types of waves into fluid-based codes are derived and shown to agree with the measured wave-driven collision frequencies.
Gallium nitride tunneling field-effect transistors exploiting polarization fields
Authors: Chaney Alexander , Turski Henryk , Nomoto Kazuki , Hu Zongyang , Encomendero Jimy , Rouvimov Sergei , Orlova Tatyana , Fay Patrick , Seabaugh Alan , Xing Huili Grace , Jena Debdeep
Published: February 2020

This report showcases a vertical tunnel field effect transistor (TFET) fabricated from a GaN/InGaN heterostructure and compares it to a gated vertical GaN p-n diode. By including a thin InGaN layer, the interband tunneling in the TFET is increased compared to the gated homojunction diode. This leads to an increased drain current of 57 μA/μm and a reduced subthreshold swing of 102 mV/dec, from 240 mV/dec. However, trap assisted tunneling prevents devices from realizing subthreshold slopes below the Boltzmann limit of 60 mV/dec. Nevertheless, this work shows the capability of tunnel field effect transistors to be realized in GaN by taking advantage of the spontaneous and piezoelectric polarization in the III-N material system.
Determining multiphoton and free carrier absorption coefficients using Fourier transform infrared spectroscopy
Authors: Cao Wentian
Published: February 2020

We present an optical absorption model that integrates wavelength dependence of two- and three-photon absorption (2PA and 3PA) and free carrier absorption (FCA) coefficients in the below bandgap regime. The model can be termed as the characteristic function for the below bandgap absorption. The measured absorption spectrum of the PbTe film using Fourier transform infrared spectroscopy agrees well with the modeled optical properties. 2PA, 3PA, and FCA coefficients in cm−1 for the entire wavelength range can be obtained from a single measurement of the below bandgap absorption spectrum. The results indicate that the remarkable 2PA and 3PA processes occur in the wavelength range from 4.18 to 7.58 μm. In addition, we implement the model in the below bandgap absorption spectra of n-Si with the room temperature carrier concentration 1.0×10−19cm−3. The predicted 2PA values by the model in cm−1 are 5.38–0.53 cm−1 in the wavelength range from 1.1 to 2.2 μm and agree well with experimental 2PA values at 1.55 μm wavelengths by the Z-scan measurement. Our paper offers an effective method in handling the below bandgap absorption measurement.
Epitaxial stabilization of ultra thin films of high entropy perovskite
Authors: Patel Ranjan Kumar , Ojha Shashank Kumar , Kumar Siddharth , Saha Akash , Mandal Prithwijit , Freeland J. W. , Middey S.
Published: February 2020

High entropy oxides (HEOs) are a class of materials, containing equimolar portions of five or more transition metal and/or rare-earth elements. We report here about the layer-by-layer growth of HEO [(La0.2Pr0.2Nd0.2Sm0.2Eu0.2)NiO3] thin films on NdGaO3 substrates by pulsed laser deposition. The combined characterizations with in situ reflection high energy electron diffraction, atomic force microscopy, and x-ray diffraction affirm the single crystalline nature of the film with smooth surface morphology. The desired +3 oxidation of Ni has been confirmed by an element sensitive x-ray absorption spectroscopy measurement. Temperature dependent electrical transport measurements revealed a first order metal-insulator transition with the transition temperature very similar to the undoped NdNiO3. Since both these systems have a comparable tolerance factor, this work demonstrates that the electronic behaviors of A-site disordered perovskite-HEOs are primarily controlled by the average tolerance factor.
Modeling of magnetic thermal noise in stable magnetic sensors
Authors: Pipathanapoompron Thalerngsak , Stankiewicz Andrzej , Subramanian Krishnan , Grier Andrew , Kaewrawang Arkom
Published: February 2020

Low-frequency noise is a critical issue in magnetic tunneling read sensors. In this work, a mechanism of low-frequency noise generation due to asymmetric oscillations is analyzed using the Langevin equation applying both biharmonic and approximated skew normal distribution energy potentials. Both models show a high degree of correlation between low-frequency noise and fluctuations of resonance oscillation amplitude only when oscillation asymmetry is present. Furthermore, the low-frequency spectrum approaches a 1/fα profile as asymmetry increases. To investigate the effect of asymmetry in magnetic read sensors, a macrospin model was developed and validated by comparison with a full micromagnetic simulation. This macrospin model was used to study low-frequency noise by introducing asymmetry via shape anisotropy of the reader. The presence of this effect of low-frequency noise generation in reader devices is confirmed with this model, and its effect with varying temperature and damping constant is investigated.
On-chip surface acoustic wave and micropipette aspiration techniques to assess cell elastic properties
Authors: Wu Yanqi , Cheng Tianhong , Chen Qianyu , Gao Bryan , Stewart Alastair G. , Lee Peter V. S.
Published: February 2020

The cytoskeletal mechanics and cell mechanical properties play an important role in cellular behaviors. In this study, in order to provide comprehensive insights into the relationship between different cytoskeletal components and cellular elastic moduli, we built a phase-modulated surface acoustic wave microfluidic device to measure cellular compressibility and a microfluidic micropipette-aspiration device to measure cellular Young's modulus. The microfluidic devices were validated based on experimental data and computational simulations. The contributions of structural cytoskeletal actin filament and microtubule to cellular compressibility and Young's modulus were examined in MCF-7 cells. The compressibility of MCF-7 cells was increased after microtubule disruption, whereas actin disruption had no effect. In contrast, Young's modulus of MCF-7 cells was reduced after actin disruption but unaffected by microtubule disruption. The actin filaments and microtubules were stained to confirm the structural alteration in cytoskeleton. Our findings suggest the dissimilarity in the structural roles of actin filaments and microtubules in terms of cellular compressibility and Young's modulus. Based on the differences in location and structure, actin filaments mainly contribute to tensile Young's modulus and microtubules mainly contribute to compressibility. In addition, different responses to cytoskeletal alterations between acoustophoresis and micropipette aspiration demonstrated that micropipette aspiration was better at detecting the change from actin cortex, while the response to acoustophoresis was governed by microtubule networks.
On the spreading of non-canonical thermals from direct numerical simulations
Authors: Liu Kai , Zgheib N. , Balachandar S.
Published: February 2020

We present results from direct numerical simulations on laminar and turbulent non-canonical thermals with an initial rectangular density distribution at a Reynolds number of Re = 500 and Re = 5000, respectively. We find the non-canonical shape to induce strong azimuthal variations in the thermal for both the laminar and turbulent cases. These include noticeable differences in downward and horizontal propagation speeds as well as differences in the strength of the vortex tube. These differences persist over a significant period of time and help generate a cross-flow component that is otherwise not present in canonical cases. The cross-flow component is in the opposite direction to that observed in gravity currents with the same initial density distribution. This is counterintuitive seeing that both flows are solely driven by buoyancy. By extracting the three-dimensional streamlines, we find the descending vortex tube to force the dense fluid to follow a helical path.
Drying kinetics and nucleation in evaporating sodium nitrate aerosols
Authors: Robinson Joshua F. , Gregson Florence K. A. , Miles Rachael E. H. , Reid Jonathan P. , Royall C. Patrick
Published: February 2020

A quantitative understanding of the evaporative drying kinetics and nucleation rates of aqueous based aerosol droplets is important for a wide range of applications, from atmospheric aerosols to industrial processes such as spray drying. Here, we introduce a numerical model for interpreting measurements of the evaporation rate and phase change of drying free droplets made using a single particle approach. We explore the evaporation of aqueous sodium chloride and sodium nitrate solution droplets. Although the chloride salt is observed to reproducibly crystallize at all drying rates, the nitrate salt solution can lose virtually all of its water content without crystallizing. The latter phenomenon has implications for our understanding of the competition between the drying rate and nucleation kinetics in these two systems. The nucleation model is used in combination with the measurements of crystallization events to infer nucleation rates at varying equilibrium state points, showing that classical nucleation theory provides a good description of the crystallization of the chloride salt but not the nitrate salt solution droplets. The reasons for this difference are considered.
On the role of intermolecular vibrational motions for ice polymorphs. II. Atomic vibrational amplitudes and localization of phonons in ordered and disordered ices
Authors: Tanaka Hideki , Yagasaki Takuma , Matsumoto Masakazu
Published: February 2020

We investigate the vibrational amplitudes and the degree of the phonon localization in 19 ice forms, both crystalline and amorphous, by a quasi-harmonic approximation with a reliable classical intermolecular interaction model for water. The amplitude in the low pressure ices increases with compression, while the opposite trend is observed in the medium and high pressure ices. The amplitude of the oxygen atom does not differ from that of hydrogen in low pressure ices apart from the contribution from the zero-point vibrations. This is accounted for by the coherent but opposite phase motions in the mixed translational and rotational vibrations. A decoupling of translation-dominant and rotation-dominant motions significantly reduces the vibrational amplitudes in any ice form. The amplitudes in ice III are found to be much larger than any other crystalline ice form. In order to investigate the vibrational mode characteristics, the moment ratio of the atomic displacements for individual phonon modes, called the inverse participation ratio, is calculated and the degree of the phonon localization in crystalline and amorphous ices is discussed. It is found that the phonon modes in the hydrogen-ordered ice forms are remarkably spread over the entire crystal having propagative or diffusive characteristic, while many localized modes appear at the edges of the vibrational bands, called dissipative modes, in the hydrogen-disordered counterparts. The degree of localization is little pronounced in low density amorphous and high density amorphous due to disordering of oxygen atoms.
Tl2O/WTe2 van der Waals heterostructure with tunable multiple band alignments
Authors: He Zhonglin , Ma Yandong , Lei Chengan , Peng Rui , Huang Baibiao , Dai Ying
Published: February 2020

Two-dimensional van der Waals heterostructures (vdWHs) with tunable band alignment can be very useful for developing minimized multifunctional and controllable devices, but so far they are scarcely reported. Here, using first-principles calculations, we systematically investigate the electronic properties of Tl2O/WTe2 vdWH. Our results indicate that it is a direct bandgap semiconductor harboring a straddling type-I band alignment, with the conduction band minimum (CBM) and valence band maximum (VBM) both from two-dimensional WTe2. Interestingly, upon introducing feasible external strain or electric field, its band alignment can be easily transformed into staggered type-II, with CBM and VBM separated in different layers, achieving the long-sought tunable multiple band alignments. Along with this, the intriguing direct-to-indirect bandgap transition is also achieved in Tl2O/WTe2 vdWH. Our work thus provides a promising candidate in the field of two-dimensional multifunctional and controllable electronics.
The limited influence of transference number on the performance of nanoscale batteries
Authors: Dwelle Kaitlyn A. , Willard Adam P.
Published: February 2020

We present a model of a nanoscale Li-ion-type battery that includes explicit, atomistic representation of the current-carrying cations and their counter-ions. We use this model to simulate the dependence of battery performance on the transference number of the electrolyte. We report simulated values of the current at constant applied voltage for a series of model electrolytes with varying cation and anion mobilities. Unlike the predictions of macroscopic device models, our simulation results reveal that under conditions of fixed cation mobility, the performance of a nanoscale battery is not improved by increasing the transference number of the electrolyte. We attribute this model discrepancy to the ability of the electrolyte to support deviations from charge neutrality over nanometer length scales and conclude that models for nanoscale electrochemical systems need to include the possibility of deviations from electroneutrality.
High-transition-temperature nanoscale superconducting quantum interference devices directly written with a focused helium ion beam
Authors: Li Hao , Cai Han , Cho Ethan Y. , McCoy Stephen J. , Wang Yan-Ting , LeFebvre Jay C. , Zhou Yuchao W. , Cybart Shane A.
Published: February 2020

In this work, we present nanoscale superconducting quantum interference devices (SQUIDs) with dimensions as small as 10 nm from the high-transition-temperature superconductor YBa2Cu3O7−δ (YBCO). The SQUID features and Josephson junctions are directly written into a 35-nm thick YBCO film with a focused helium ion beam. We integrate these nano-SQUIDs with directly written nano-isolated inductively coupled control lines to demonstrate a low power superconducting output driver capable of transimpedance conversion over a very wide temperature range of 4–50 K.
Triple group-V donors in ZnO
Authors: Hegde Manu , Mohammadbeigi F. , Kure T. , Senthil Kumar E. , Wagner M. R. , Hoffmann A. , Watkins S. P.
Published: February 2020

Triple donors have been explored in a few semiconductor materials; however, the conventional effective mass theory treatment fails at short length scales due to the high degree of localization implied by a 3+ nuclear charge. Using density functional theory, we consider the various charge states of group-V elements substituting for the Zn sublattice in ZnO under oxygen-rich conditions. For the case of Sb and Bi substitutional impurities, the (1+/0) charge state transition is shallow and has strong similarities to a (1+/0) charge transition of the more common shallow group III donors such as Ga and Al. We compare these calculations with extensive photoluminescence (PL) measurements that now exist for the Sb-related donor bound exciton in ZnO, which is known to contain substitutional Sb on Zn sites. We present new experimental data on the magneto-PL properties of the Sb-related donor bound exciton. These data confirm the strong similarity of the (+1/0) charge state transition of this center to the common group III shallow donors in ZnO. We propose that the very low binding energy (40.2 meV) of the neutral Sb donor is due to a combination of increased screening due to the two inner donor electrons, as well as the exclusion principle, resulting in a repulsive central cell potential close to the defect core.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: February 2020

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials which supersede earlier data or suggest new research applications.
Simple closed geodesics on regular tetrahedra in Lobachevsky space
Authors: Borisenko A. A. , Sukhorebska D. D.
Published: February 2020

All simple closed geodesics on regular tetrahedra in Lobachevsky space are described. The asymptotic behaviour is found for the number of simple closed geodesics of length

, as

tends to infinity.

Bibliography: 22 titles.
Waring’s problem in natural numbers of special form
Authors: Eminyan K. M.
Published: February 2020

Let

be the set of positive integers whose binary decompositions contain an even number of ones. We give a bound for the trigonometric sum of special form over numbers in

; using this bound, we derive an asymptotic formula for the number of solutions to Waring’s equation in positive integers in

, and also a bound for the number of terms in the last equation, which is sufficient for the equation to be solvable in integers in

.

Bibliography: 9 titles.
In vivo digestibility of a range of silages in cattle compared with sheep
Authors: Bailes K. L. , Piltz J. W. , McNeill D. M.
Published: February 2020

Context
Ensuring accuracy of feed testing is becoming increasingly important as livestock industries seek to maximise efficiency of producing animal products to meet world requirements.

Aim
Twenty-four silages were fed to sheep and cattle to test the validity of using sheep-derived digestibility estimates for cattle.

Method
The silages tested included temperate and subtropical forages, and differed in level of maturity and weed contamination at harvest: several of the forage crops were grown with irrigation. In vivo comparisons were made for digestibility of dry matter (DMD), organic matter (OMD), and organic matter in the dry matter (DOMD) across two experiments. Intake was restricted to 16.5 g/kg liveweight and those silages with low nitrogen (N) contents were supplemented with urea to meet minimum dietary crude protein requirements.

Key results
DMD, OMD and DOMD ranged from 0.538 to 0.773, 0.550 to 0.810, 0.505 to 0.762 and 0.551 to 0.749, 0.584 to 0.786, 0.539 to 0.702 for cattle and sheep respectively. DMD, OMD and DOMD determined in sheep explained 88.7, 86.3 and 78.4% of the variation of DMD, OMD and DOMD in cattle respectively. In Experiment 1, DOMD was higher in cattle than sheep but for two silages (Silage 1, Subterranean clover: 0.631 vs 0.589; Silage 5, Annual ryegrass/oats, early cut: 0.761 vs 0.702) whereas in Experiment 2 DOMD was lower for cattle than sheep for one silage (silage 21, maize: 0.645 vs 0.691, s.e.d. = 0.019).

Conclusions and Implications
Since there was no clear trend for sheep to digest higher quality feeds better than cattle or for cattle to digest lower quality feeds better than sheep, we conclude that, at least for silages made from forage, sheep-derived values for digestibility should, in most instances, be applicable to cattle.
Hurricanes fertilize mangrove forests in the Gulf of Mexico (Florida Everglades, USA)
Authors: Castañeda-Moya Edward , Rivera-Monroy Victor H. , Chambers Randolph M. , Zhao Xiaochen , Lamb-Wotton Lukas , Gorsky Adrianna , Gaiser Evelyn E. , Troxler Tiffany G. , Kominoski John S. , Hiatt Matthew
Published: February 2020

Hurricanes are recurring high-energy disturbances in coastal regions that change community structure and function of mangrove wetlands. However, most of the studies assessing hurricane impacts on mangroves have focused on negative effects without considering the positive influence of hurricane-induced sediment deposition and associated nutrient fertilization on mangrove productivity and resilience. Here, we quantified how Hurricane Irma influenced soil nutrient pools, vertical accretion, and plant phosphorus (P) uptake after its passage across the Florida Coastal Everglades in September 2017. Vertical accretion from Irma’s deposits was 6.7 to 14.4 times greater than the long-term (100 y) annual accretion rate (0.27 ± 0.04 cm y−1). Storm deposits extended up to 10-km inland from the Gulf of Mexico. Total P (TP) inputs were highest at the mouth of estuaries, with P concentration double that of underlying surface (top 10 cm) soils (0.19 ± 0.02 mg cm−3). This P deposition contributed 49 to 98% to the soil nutrient pool. As a result, all mangrove species showed a significant increase in litter foliar TP and soil porewater inorganic P concentrations in early 2018, 3 mo after Irma’s impact, thus underscoring the interspecies differences in nutrient uptake. Mean TP loading rates were five times greater in southwestern (94 ± 13 kg ha−1d−1) mangrove-dominated estuaries compared to the southeastern region, highlighting the positive role of hurricanes as a natural fertilization mechanism influencing forest productivity. P-rich, mineral sediments deposited by hurricanes create legacies that facilitate rapid forest recovery, stimulation of peat soil development, and resilience to sea-level rise.
The evolution of early symbolic behavior inHomo sapiens
Authors: Tylén Kristian , Fusaroli Riccardo , Rojo Sergio , Heimann Katrin , Fay Nicolas , Johannsen Niels N. , Riede Felix , Lombard Marlize
Published: February 2020

How did human symbolic behavior evolve? Dating up to about 100,000 y ago, the engraved ochre and ostrich eggshell fragments from the South African Blombos Cave and Diepkloof Rock Shelter provide a unique window into presumed early symbolic traditions ofHomo sapiensand how they evolved over a period of more than 30,000 y. Using the engravings as stimuli, we report five experiments which suggest that the engravings evolved adaptively, becoming better-suited for human perception and cognition. More specifically, they became more salient, memorable, reproducible, and expressive of style and human intent. However, they did not become more discriminable over time between or within the two archeological sites. Our observations provide support for an account of the Blombos and Diepkloof engravings as decorations and as socially transmitted cultural traditions. By contrast, there was no clear indication that they served as denotational symbolic signs. Our findings have broad implications for our understanding of early symbolic communication and cognition inH. sapiens.
Time-evolving sea-surface warming patterns modulate the climate change response of subtropical precipitation over land
Authors: Zappa Giuseppe , Ceppi Paulo , Shepherd Theodore G.
Published: February 2020

Greenhouse gas (GHG) emissions affect precipitation worldwide. The response is commonly described by two timescales linked to different processes: a rapid adjustment to radiative forcing, followed by a slower response to surface warming. However, additional timescales exist in the surface-warming response, tied to the time evolution of the sea-surface-temperature (SST) response. Here, we show that in climate model projections, the rapid adjustment and surface mean warming are insufficient to explain the time evolution of the hydro-climate response in three key Mediterranean-like areas—namely, California, Chile, and the Mediterranean. The time evolution of those responses critically depends on distinct shifts in the regional atmospheric circulation associated with the existence of distinct fast and slow SST warming patterns. As a result, Mediterranean and Chilean drying are in quasiequilibrium with GHG concentrations, meaning that the drying will not continue after GHG concentrations are stabilized, whereas California wetting will largely emerge only after GHG concentrations are stabilized. The rapid adjustment contributes to a reduction in precipitation, but has a limited impact on the balance between precipitation and evaporation. In these Mediterranean-like regions, future hydro-climate–related impacts will be substantially modulated by the time evolution of the pattern of SST warming that is realized in the real world.
Nitrifier adaptation to low energy flux controls inventory of reduced nitrogen in the dark ocean
Authors: Zhang Yao , Qin Wei , Hou Lei , Zakem Emily J. , Wan Xianhui , Zhao Zihao , Liu Li , Hunt Kristopher A. , Jiao Nianzhi , Kao Shuh-Ji , Tang Kai , Xie Xiabing , Shen Jiaming , Li Yufang , Chen Mingming , Dai Xiaofeng , Liu Chang , Deng Wenchao , Dai Minhan , Ingalls Anitra E. , Stahl David A. , Herndl Gerhard J.
Published: February 2020

Ammonia oxidation to nitrite and its subsequent oxidation to nitrate provides energy to the two populations of nitrifying chemoautotrophs in the energy-starved dark ocean, driving a coupling between reduced inorganic nitrogen (N) pools and production of new organic carbon (C) in the dark ocean. However, the relationship between the flux of new C production and the fluxes of N of the two steps of oxidation remains unclear. Here, we show that, despite orders-of-magnitude difference in cell abundances between ammonia oxidizers and nitrite oxidizers, the two populations sustain similar bulk N-oxidation rates throughout the deep waters with similarly high affinities for ammonia and nitrite under increasing substrate limitation, thus maintaining overall homeostasis in the oceanic nitrification pathway. Our observations confirm the theoretical predictions of a redox-informed ecosystem model. Using balances from this model, we suggest that consistently low ammonia and nitrite concentrations are maintained when the two populations have similarly high substrate affinities and their loss rates are proportional to their maximum growth rates. The stoichiometric relations between the fluxes of C and N indicate a threefold to fourfold higher C-fixation efficiency per mole of N oxidized by ammonia oxidizers compared to nitrite oxidizers due to nearly identical apparent energetic requirements for C fixation of the two populations. We estimate that the rate of chemoautotrophic C fixation amounts to ∼1 × 10
13
to ∼2 × 10
13
mol of C per year globally through the flux of ∼1 × 10
14
to ∼2 × 10
14
mol of N per year of the two steps of oxidation throughout the dark ocean.
Spatial mapping of tissue properties in vivo reveals a 3D stiffness gradient in the mouse limb bud
Authors: Zhu Min , Tao Hirotaka , Samani Mohammad , Luo Mengxi , Wang Xian , Hopyan Sevan , Sun Yu
Published: February 2020

Numerous hypotheses invoke tissue stiffness as a key parameter that regulates morphogenesis and disease progression. However, current methods are insufficient to test hypotheses that concern physical properties deep in living tissues. Here we introduce, validate, and apply a magnetic device that generates a uniform magnetic field gradient within a space that is sufficient to accommodate an organ-stage mouse embryo under live conditions. The method allows rapid, nontoxic measurement of the three-dimensional (3D) spatial distribution of viscoelastic properties within mesenchyme and epithelia. Using the device, we identify an anteriorly biased mesodermal stiffness gradient along which cells move to shape the early limb bud. The stiffness gradient corresponds to a
Wnt5a
-dependent domain of fibronectin expression, raising the possibility that durotaxis underlies cell movements. Three-dimensional stiffness mapping enables the generation of hypotheses and potentially the rigorous testing of mechanisms of development and disease.
Noninvasive muscle activity imaging using magnetography
Authors: Llinás Rodolfo R. , Ustinin Mikhail , Rykunov Stanislav , Walton Kerry D. , Rabello Guilherme M. , Garcia John , Boyko Anna , Sychev Vyacheslav
Published: February 2020

A spectroscopic paradigm has been developed that allows the magnetic field emissions generated by the electrical activity in the human body to be imaged in real time. The growing significance of imaging modalities in biology is evident by the almost exponential increase of their use in research, from the molecular to the ecological level. The method of analysis described here allows totally noninvasive imaging of muscular activity (heart, somatic musculature). Such imaging can be obtained without additional methodological steps such as the use of contrast media.
The role of critical micellization concentration in efficacy and toxicity of supramolecular polymers
Authors: Su Hao , Wang Feihu , Ran Wei , Zhang Weijie , Dai Wenbing , Wang Han , Anderson Caleb F. , Wang Zongyuan , Zheng Chao , Zhang Pengcheng , Li Yaping , Cui Honggang
Published: February 2020

Significance

Critical micellization concentration (CMC) is an important design consideration for developing all supramolecular biomaterials, and in particular for drug delivery systems. Once placed in an in vivo setting, supramolecular materials will start to dissociate into monomeric units, providing a means for therapeutic release and an essential pathway for clearance. This beneficial phenomenon could also lead to premature drug release and degradation. Through the design of a series of self-assembling prodrugs (SAPDs) of various CMCs, we developed a fundamental understanding of the role of CMC in therapeutic efficacy of supramolecular polymers. We found that the two important parameters of assessing a drug potential (efficacy and toxicity) can be correlated to the SAPD’s supramolecular form and monomeric form, respectively.
Historical comparison of gender inequality in scientific careers across countries and disciplines
Authors: Huang Junming , Gates Alexander J. , Sinatra Roberta , Barabási Albert-László
Published: February 2020

Significance

Empirical evidence suggests significant gender differences in the total productivity and impact of academic careers across science, technology, engineering, and mathematics (STEM) fields. Paradoxically, the increase in the number of women academics over the past 60 years has increased these gender differences. Yet, we find that men and women publish a comparable number of papers per year and have equivalent career-wise impact for the same total number of publications. This suggests the productivity and impact of gender differences are explained by different publishing career lengths and dropout rates. This comprehensive picture of gender inequality in academic publishing can help rephrase the conversation around the sustainability of women’s careers in academia, with important consequences for institutions and policy makers.
The emergence and resilience of self-organized governance in coupled infrastructure systems
Authors: Muneepeerakul Rachata , Anderies John M.
Published: February 2020

Significance

Many small-scale, self-organized systems have persisted for hundreds of years and been the subject of studies seeking to understand effective governance. The lack of formal analytically tractable models of such coupled infrastructure systems hinders linking knowledge gained from those studies to such concepts as resilience and robustness. Here, we develop a stylized, generic model of these systems. The analysis clarifies complex interactions and feedbacks that yield different system outcomes. The boundaries between these outcomes are expressed in clear functions of biophysical and socioeconomic factors and can potentially be used to develop resilience metrics. Such regime boundaries clarify how changes in biophysical and socioeconomic drivers affect the system outcome and what changes in governance may be required to maintain its sustainability.
The vortex gas scaling regime of baroclinic turbulence
Authors: Gallet Basile , Ferrari Raffaele
Published: February 2020

Significance

Developing a theory of climate requires an accurate parameterization of the transport induced by turbulent eddies. A major source of turbulence in the midlatitude planetary atmospheres and oceans is the baroclinic instability of the large-scale flows. We present a scaling theory that quantitatively predicts the local heat flux, eddy kinetic energy, and mixing length of baroclinic turbulence as a function of the large-scale flow characteristics and bottom friction. The theory is then used as a quantitative parameterization in the case of meridionally dependent forcing in the fully turbulent regime. Beyond its relevance for climate theories, our work is an intriguing example of a successful closure for a fully turbulent flow.
Essential requirement for nicastrin in marginal zone and B-1 B cell development
Authors: Choi Jin Huk , Han Jonghee , Theodoropoulos Panayotis C. , Zhong Xue , Wang Jianhui , Medler Dawson , Ludwig Sara , Zhan Xiaoming , Li Xiaohong , Tang Miao , Gallagher Thomas , Yu Gang , Beutler Bruce
Published: February 2020

Significance

Follicular B cells generally require T cell help to contribute to adaptive immunity, producing several isotypes of immunoglobulins that carry out distinct effector functions. Two specialized B cell subsets, marginal zone (MZ) and B-1 B cells, arise from different developmental steps and have different functions. They become activated to produce antibodies without T cell help and are the major sources of plasma IgM. We identified a viable missense allele of Ncstn in a forward genetic screen. We discovered that the development of MZ and B-1 B cells, TI antibody response, fur pigmentation, and intestinal homeostasis critically depend on the glycosylation status of NCSTN and the catalytic activity of γ-secretase toward its substrate Notch, a critical receptor in numerous developmental decisions.