bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolving academic culture to meet societal needs
Authors: Wowk Kateryna , McKinney Larry , Muller-Karger Frank , Moll Russell , Avery Susan , Escobar-Briones Elva , Yoskowitz David , McLaughlin Richard
Published: November 2017

Abstract

Given today’s complex societal challenges, academia should work better with government, industry and others in offering innovative solutions that benefit our society, economy and environment. Researchers across disciplines must work together and with decision-makers to understand how science can have better on-the-ground impacts toward longer-term, resilient societal outcomes. This includes, for example, by working with end-users in problem formation and throughout research projects to ensure decision-making needs are being met, and by linking physical science to additional fields like economics, risk communication or psychology. However, persistent barriers to collaborating across disciplines and with external decision-makers remain. Despite decades of studies highlighting the need for interdisciplinary research and science for decision-making, academic institutions are still not structured to facilitate or reward such collaboration. A group of researchers and educators used a mixed-methods approach to consider the knowledge base on interdisciplinary research and evidence-based policymaking, as well as their own experiences, and formed targeted and actionable recommendations that can help academia overcome these barriers. Their recommendations, specifically targeted to administrators, institutional leads, individual researchers, and research funders, align to three categories: define the role of academia in linking to policy; incorporate nontraditional standards in evaluating success; and build trust while drawing the line between knowledge dissemination and activism. By implementing the following recommendations, academics can foster the culture change that is needed to promote interdisciplinarity, strengthen the impact of their work and help society address urgent and multi-faceted problems.
In search of periodic solutions for a reduction of the Benney chain
Authors: Bialy Misha , Mironov Andrey E.
Published: November 2017

We search for smooth periodic solutions for the system of quasi-linear equations known as the Lax dispersionless reduction of the Benney moments chain. It is naturally related to the existence of a polynomial in momenta integral for a classical Hamiltonian system with 1,5 degrees of freedom. For the solution in question, it is not known a priori if the system is elliptic or hyperbolic or of mixed type. We consider two possible regimes for the solution. The first is the case of only one real eigenvalue, where we can completely classify the solutions. The second case of strict hyperbolicity is really a challenge. We find a remarkable 2 × 2 reduction which is strictly hyperbolic with one umbilic point but violates the condition of genuine non-linearity.
A broadened classical master equation approach for treating electron-nuclear coupling in non-equilibrium transport
Authors: Dou Wenjie , Schinabeck Christian , Thoss Michael , Subotnik Joseph E.
Published: November 2017

We extend the broadened classical master equation (bCME) approach [W. Dou and J. E. Subotnik, J. Chem. Phys. 144, 024116 (2016)] to the case of two electrodes, such that we may now calculate non-equilibrium transport properties when molecules come near metal surfaces and there is both strong electron-nuclear and strong metal-molecule coupling. By comparing against a numerically exact solution, we show that the bCME usually works very well, provided that the temperature is high enough that a classical treatment of nuclear motion is valid. Finally, in the low temperature (quantum) regime, we suggest a means to incorporate broadening effects in the quantum master equation (QME). This bQME works well for fairly low temperatures.
Insight into the effect of screw dislocations and oxygen vacancy defects on the optical nonlinear refraction response in chemically grown ZnO/Al2O3 films
Authors: Agrawal Arpana , Saroj Rajendra K. , Dar Tanveer A. , Baraskar Priyanka , Sen Pratima , Dhar Subhabrata
Published: November 2017

We report the effect of screw dislocations and oxygen vacancy defects on the optical nonlinear refraction response of ZnO films grown on a sapphire substrate at various oxygen flow rates using the chemical vapor deposition technique. The nonlinear refraction response was investigated in the off-resonant regime using a CW He-Ne laser source to examine the role of the intermediate bandgap states. It has been observed that the structural defects strongly influence the optical nonlinearity in the off-resonant regime. Nonlinearity has been found to improve as the oxygen flow rate is lowered from 2 sccm to 0.3 sccm. From photoluminescence studies, we observe that the enhanced defect density of the electronic defect levels due to the increased concentration of structural defects (with the decrease in the oxygen flow rate) is responsible for this improved optical nonlinearity along with the thermal effect. This suggests that defect engineering is an effective way to tailor the nonlinearity of ZnO films and their utility for optoelectronic device applications.
OMNY PIN—A versatile sample holder for tomographic measurements at room and cryogenic temperatures
Authors: Holler M. , Raabe J. , Wepf R. , Shahmoradian S. H. , Diaz A. , Sarafimov B. , Lachat T. , Walther H. , Vitins M.
Published: November 2017

Nowadays ptychographic tomography in the hard x-ray regime, i.e., at energies above about 2 keV, is a well-established measurement technique. At the Paul Scherrer Institut, currently two instruments are available: one is measuring at room temperature and atmospheric pressure, and the other, the so-called OMNY (tOMography Nano crYo) instrument, is operating at ultra-high vacuum and offering cryogenic sample temperatures down to 10 K. In this manuscript, we present the sample mounts that were developed for these instruments. Aside from excellent mechanical stability and thermal conductivity, they also offer highly reproducible mounting. Various types were developed for different kinds of samples and are presented in detail, including examples of how specimens can be mounted on these holders. We also show the first hard x-ray ptychographic tomography measurements of high-pressure frozen biological samples, in the present case Chlamydomonas cells, the related sample pins and preparation steps. For completeness, we present accessories such as transportation containers for both room temperature and cryogenic samples and a gripper mechanism for automatic sample changing. The sample mounts are not limited to x-ray tomography or hard x-ray energies, and we believe that they can be very useful for other instrumentation projects.
Detonation propagation in annular arcs of condensed phase explosives
Authors: Ioannou Eleftherios , Schoch Stefan , Nikiforakis Nikolaos , Michael Louisa
Published: November 2017

We present a numerical study of detonation propagation in unconfined explosive charges shaped as an annular arc (rib). Steady detonation in a straight charge propagates at constant speed, but when it enters an annular section, it goes through a transition phase and eventually reaches a new steady state of constant angular velocity. This study examines the speed of the detonation wave along the annular charge during the transition phase and at steady state, as well as its dependence on the dimensions of the annulus. The system is modeled using a recently proposed diffuse-interface formulation which allows for the representation of a two-phase explosive and of an additional inert material. The explosive considered is the polymer-bonded TATB-based LX-17 and is modeled using two Jones-Wilkins-Lee (JWL) equations of state and the ignition and growth reaction rate law. Results show that steady state speeds are in good agreement with experiment. In the transition phase, the evolution of outer detonation speed deviates from the exponential bounded growth function suggested by previous studies. We propose a new description of the transition phase which consists of two regimes. The first regime is caused by local effects at the outer edge of the annulus and leads to a dependence of the outer detonation speed on the angular position along the arc. The second regime is induced by effects originating from the inner edge of the annular charge and leads to the deceleration of the outer detonation until steady state is reached. The study concludes with a parametric study where the dependence of the steady state and the transition phase on the dimensions of the annulus is investigated.
Theoretical study of photodetachment spectroscopy of hydrogenated boron cluster anion H2B7− and its deuterated isotopomer
Authors: Sarkar Rudraditya , Mahapatra S.
Published: November 2017

Photodetachment spectroscopy of H2B7− and its deuterated isotopomer probing the energetically low-lying electronic states of the respective neutral cluster is theoretically investigated in this paper. The theoretical methodology is based on detailed quantum chemistry calculations of electronic state energies, construction of a vibronic coupling model in the diabatic electronic basis, and nuclear dynamics calculations from first principles using time-dependent and time-independent quantum mechanical methods. The theoretical model consists of five coupled electronic states and fifteen vibrational modes. Several reduced dimensional calculations are performed to identify the relevant vibrational modes contributing to the vibronic structure of electronic bands and the impact of non-adiabatic coupling on them. The low-energy part of the spectrum of both H2B7 and its deuterated analogue is assigned by examining the vibronic wavefunctions and the results are compared with the experimental findings. The nonadiabatic decay dynamics of the electronic excited states of the neutral clusters is examined at length.
Deterministic filtering of breakdown flashing at telecom wavelengths
Authors: Marini Loris , Camphausen Robin , Eggleton Benjamin J. , Palomba Stefano
Published: November 2017

Breakdown flashes are undesired photo-emissions from the active area of single-photon avalanche photo-diodes. They arise from radiative recombinations of hot carriers generated during an avalanche and can induce crosstalk, compromise the measurement of optical quantum states, and hinder the security of quantum communications. Although the spectrum of this emission extends over hundreds of nanometers, active quenching may lead to a smaller uncertainty in the time of emission, thus enabling deterministic filtering. Our results pave the way to broadband interference mitigation in time-correlated single-photon applications.
Pulling force and surface tension drive membrane fusion
Authors: Liu Xuejuan , Tian Falin , Yue Tongtao , Zhang Xianren , Zhong Chongli
Published: November 2017

Despite catalyzed by fusion proteins of quite different molecular architectures, intracellular, viral, and cell-to-cell fusions are found to have the essential common features and the nearly same nature of transition states. The similarity inspires us to find a more general catalysis mechanism for membrane fusion that minimally depends on the specific structures of fusion proteins. In this work, we built a minimal model for membrane fusion, and by using dissipative particle dynamics simulations, we propose a mechanism that the pulling force generated by fusion proteins initiates the fusion process and the membrane tension regulates the subsequent fusion stages. The model shows different features compared to previous computer simulation studies: the pulling force catalyzes membrane fusion through lipid head overcrowding in the contacting region, leading to an increase in the head-head repulsion and/or the unfavorable head-tail contacts from opposing membranes, both of which destabilize the contacting leaflets and thus promote membrane fusion or vesicle rupture. Our simulations produce a variety of shapes and intermediates, closely resembling cases seen experimentally. Our work strongly supports the view that the tight pulling mechanism is a conserved feature of fusion protein-mediated fusion and that the membrane tension plays an essential role in fusion.
Ka-band relativistic diffraction generator with a tapered coaxial Bragg reflector
Authors: Lan Feng , Yang Ziqiang , Mazumder Pinaki , Shi Zongjun , Meng Lin , Liu Dagang , Fu Wenjie
Published: November 2017

A coaxial line with periodically tapered inner rode corrugated ripples is introduced to act as a distributed Bragg reflector to increase output microwave power of relativistic diffraction generator (RDG). The RDG device consists of an overmoded cross-section, two-sectional disk-loaded cylindrical slow-wave structure (SWS), and coaxial reflector is placed upstream at the first SWS section. The RDG device with tapered Bragg reflector is investigated by full three-dimensional Particle-in-Cell (PIC) simulations and experiments in this paper. The structural parameters of the reflector are optimized for favorable characteristic of mode selection and frequency response. It is found that oscillation modes varied at different magnetic field magnitude. The measured radiation power at 29∼31 GHz is over 300 MW for TM01 mode and over 700 MW for TM11 mode. Results show that the reflector has a great impact on performance of the device. Operating at proper conditions, the radiation power is remarkably enhanced.
Electronic control of linear-to-circular polarization conversion using a reconfigurable metasurface
Authors: Ratni Badreddine , de Lustrac André , Piau Gérard-Pascal , Burokur Shah Nawaz
Published: November 2017

A reflective metasurface enabling linear-to-circular polarization (LP-to-CP) conversion is proposed. The metasurface polarizer is composed of active unit cells incorporating voltage-controlled varactor diodes, where the dispersion responses of the cells can be tailored. When illuminated by an incident wave, the metasurface converts the LP wave from the source to a CP one. Moreover, in a single voltage configuration, two circular polarized waves with different handedness can be obtained at distinct frequencies. Such operation can be tuned in frequency by changing the applied voltage along the metasurface. Simulations are performed to verify the concept, and measurements done on a fabricated prototype validate the polarization conversion performances at microwave frequencies.
Reversible control of doping in graphene-on-SiO2 by cooling under gate-voltage
Authors: Singh Anil Kumar , Gupta Anjan Kumar
Published: November 2017

The electronic properties of graphene can be modulated by various doping techniques other than back-gate, but most such methods are not easily reversible and also lead to mobility reduction. Here, we report on the reversible control of doping in graphene by cooling under back-gate-voltage. The observed variation in hysteresis in our devices with the temperature and interface preparation method is attributed to the variation in the density of redox species, namely, H2O and O2, at the graphene/SiO2 interface, and their diffusion. With careful interface preparation, we have been able to make devices with negligible hysteresis at room temperature and by exploiting hysteresis at high temperatures, we get a wide, but reversible tunability of interface charge density and graphene doping, by cooling to room temperature under gate-voltage. Such reversible control of graphene doping by manipulating the interface defect charge density can help in making new data storage devices using graphene.
Extracting elastic properties of an atomically thin interfacial layer by time-domain analysis of femtosecond acoustics
Authors: Chen H.-Y. , Huang Y.-R. , Shih H.-Y. , Chen M.-J. , Sheu J.-K. , Sun C.-K.
Published: November 2017

Modern devices adopting denser designs and complex 3D structures have created much more interfaces than before, where atomically thin interfacial layers could form. However, fundamental information such as the elastic property of the interfacial layers is hard to measure. The elastic property of the interfacial layer is of great importance in both thermal management and nano-engineering of modern devices. Appropriate techniques to probe the elastic properties of interfacial layers as thin as only several atoms are thus critically needed. In this work, we demonstrated the feasibility of utilizing the time-resolved femtosecond acoustics technique to extract the elastic properties and mass density of a 1.85-nm-thick interfacial layer, with the aid of transmission electron microscopy. We believe that this femtosecond acoustics approach will provide a strategy to measure the absolute elastic properties of atomically thin interfacial layers.
Sustaining high-energy orbits of bi-stable energy harvesters by attractor selection
Authors: Udani Janav P. , Arrieta Andres F.
Published: November 2017

Nonlinear energy harvesters have the potential to efficiently convert energy over a wide frequency range; however, difficulties in attaining and sustaining high-energy oscillations restrict their applicability in practical scenarios. In this letter, we propose an actuation methodology to switch the state of bi-stable harvesters from the low-energy intra-well configuration to the coexisting high-energy inter-well configuration by controlled phase shift perturbations. The strategy is designed to introduce a change in the system state without creating distinct metastable attractors by exploiting the basins of attraction of the coexisting stable attractors. Experimental results indicate that the proposed switching strategy yields a significant improvement in energy transduction capabilities, is highly economical, enabling the rapid recovery of energy spent in the disturbance, and can be practically implemented with widely used low-strain piezoelectric transducers.
Prediction dynamic model of shock train with complex background waves
Authors: Li Nan , Chang Jun-Tao , Xu Ke-Jing , Yu Da-Ren , Bao Wen , Song Yan-Ping
Published: November 2017

Oblique shock waves are unavoidable in a rectangular hypersonic inlet, leading to a non-uniform flow field. While a significant body of the literature exists regarding the shock train modeling in a uniform incoming flow condition, few efforts have focused on the shock train behavior considering the influence of the shock wave boundary layer interactions. A low-order dynamic model of the shock train has been constructed with the help of the free interaction theory and a 1-D analysis approach. Experimental and numerical investigations have been carried out to evaluate the low-order model. The results show that the model has the capability of qualitatively analyzing the shock train behavior. In the cases with incident shocks, the rapid forward movement of the shock train has been observed by experiment. Besides this phenomenon was also modeled using the low-order model. Schlieren images show that when the shock train approaches the interaction zone, its behavior is characterized by oscillation and then follows a rapid forward movement with a linear increasing backpressure at 2.7 Ma. This phenomenon is analyzed theoretically based on the free interaction theory. Meanwhile with the help of the direct numerical simulation results from some existing studies, the flow structures in the interaction region and the following boundary layer also provide the evidence.
Path integral Monte Carlo simulations of dense carbon-hydrogen plasmas
Authors: Zhang Shuai , Militzer Burkhard , Benedict Lorin X. , Soubiran François , Sterne Philip A. , Driver Kevin P.
Published: November 2017

Carbon-hydrogen plasmas and hydrocarbon materials are of broad interest to laser shock experimentalists, high energy density physicists, and astrophysicists. Accurate equations of state (EOSs) of hydrocarbons are valuable for various studies from inertial confinement fusion to planetary science. By combining path integral Monte Carlo (PIMC) results at high temperatures and density functional theory molecular dynamics results at lower temperatures, we compute the EOSs for hydrocarbons from simulations performed at 1473 separate (ρ, T)-points distributed over a range of compositions. These methods accurately treat electronic excitation effects with neither adjustable parameter nor experimental input. PIMC is also an accurate simulation method that is capable of treating many-body interaction and nuclear quantum effects at finite temperatures. These methods therefore provide a benchmark-quality EOS that surpasses that of semi-empirical and Thomas-Fermi-based methods in the warm dense matter regime. By comparing our first-principles EOS to the LEOS 5112 model for CH, we validate the specific heat assumptions in this model but suggest that the Grüneisen parameter is too large at low temperatures. Based on our first-principles EOSs, we predict the principal Hugoniot curve of polystyrene to be 2%-5% softer at maximum shock compression than that predicted by orbital-free density functional theory and SESAME 7593. By investigating the atomic structure and chemical bonding of hydrocarbons, we show a drastic decrease in the lifetime of chemical bonds in the pressure interval from 0.4 to 4 megabar. We find the assumption of linear mixing to be valid for describing the EOS and the shock Hugoniot curve of hydrocarbons in the regime of partially ionized atomic liquids. We make predictions of the shock compression of glow-discharge polymers and investigate the effects of oxygen content and C:H ratio on its Hugoniot curve. Our full suite of first-principles simulation results may be used to benchmark future theoretical investigations pertaining to hydrocarbon EOSs and should be helpful in guiding the design of future experiments on hydrocarbons in the gigabar regime.
Quantum cascade lasers transfer-printed on silicon-on-sapphire
Authors: Jung Seungyong , Kirch Jeremy , Kim Jae Hyun , Mawst Luke J. , Botez Dan , Belkin Mikhail A.
Published: November 2017

We demonstrate coupling of the laser mode into a passive waveguide by transfer-printing fully processed mid-infrared quantum cascade lasers onto a silicon-on-sapphire platform. The laser waveguide mode is coupled into a silicon waveguide via an adiabatic taper. The experimentally achieved coupling efficiency of the taper is estimated to be ∼10%, and theoretical calculations show that coupling efficiency over 75% is achievable by reducing the adhesive layer thickness to below 100 nm. Light coupling to silicon waveguides is confirmed by images taken at the output facet of a 3-mm-long passive Si waveguide with a mid-infrared camera. Our technique enables the development of heterogeneous photonic systems integrated with a wide range of fully processed semiconductor laser devices, including buried-heterostructure lasers, which was not previously possible.
Photoinduced transformations of indole and 3-formylindole monomers isolated in low-temperature matrices
Authors: Reva Igor , Lapinski Leszek , Lopes Jesus A. J. , Nowak Maciej J.
Published: November 2017

Photochemical transformations were studied for monomers of indole and 3-formylindole isolated in low-temperature noble-gas matrices. Upon UV (λ > 270 nm) irradiation of indole trapped in argon and neon matrices, the initial 1H-form of the compound converted into the 3H-tautomer. Alongside this photoinduced hydrogen-atom transfer, an indolyl radical was also generated by photodetachment of the hydrogen atom from the N1–H bond. Excitation of 3-formylindole isolated in an argon matrix with UV (λ > 335 nm) light led to interconversion between the two conformers of the 1H-tautomer, differing from each other in the orientation of the formyl group (cis or trans). Parallel to this conformational phototransformation, the 3H-form of the compound was generated in the 1H → 3H phototautomeric conversion. The photoproducts emerging upon UV irradiation of indole and 3-formylindole were identified by comparison of their infrared spectra with the spectra calculated for candidate structures.
Path integral molecular dynamics for exact quantum statistics of multi-electronic-state systems
Authors: Liu Xinzijian , Liu Jian
Published: November 2017

An exact approach to compute physical properties for general multi-electronic-state (MES) systems in thermal equilibrium is presented. The approach is extended from our recent progress on path integral molecular dynamics (PIMD), Liu et al. [J. Chem. Phys. 145, 024103 (2016)] and Zhang et al. [J. Chem. Phys. 147, 034109 (2017)], for quantum statistical mechanics when a single potential energy surface is involved. We first define an effective potential function that is numerically favorable for MES-PIMD and then derive corresponding estimators in MES-PIMD for evaluating various physical properties. Its application to several representative one-dimensional and multi-dimensional models demonstrates that MES-PIMD in principle offers a practical tool in either of the diabatic and adiabatic representations for studying exact quantum statistics of complex/large MES systems when the Born-Oppenheimer approximation, Condon approximation, and harmonic bath approximation are broken.
Opinion evolution in different social acquaintance networks
Authors: Chen Xi , Zhang Xiao , Wu Zhan , Wang Hongwei , Wang Guohua , Li Wei
Published: November 2017

Social acquaintance networks influenced by social culture and social policy have a great impact on public opinion evolution in daily life. Based on the differences between socio-culture and social policy, three different social acquaintance networks (kinship-priority acquaintance network, independence-priority acquaintance network, and hybrid acquaintance network) incorporating heredity proportion ph and variation proportion pv are proposed in this paper. Numerical experiments are conducted to investigate network topology and different phenomena during opinion evolution, using the Deffuant model. We found that in kinship-priority acquaintance networks, similar to the Chinese traditional acquaintance networks, opinions always achieve fragmentation, resulting in the formation of multiple large clusters and many small clusters due to the fact that individuals believe more in their relatives and live in a relatively closed environment. In independence-priority acquaintance networks, similar to Western acquaintance networks, the results are similar to those in the kinship-priority acquaintance network. In hybrid acquaintance networks, similar to the Chinese modern acquaintance networks, only a few clusters are formed indicating that in modern China, opinions are more likely to reach consensus on a large scale. These results are similar to the opinion evolution phenomena in modern society, proving the rationality and applicability of network models combined with social culture and policy. We also found a threshold curve pv+2ph=2.05 in the results for the final opinion clusters and evolution time. Above the threshold curve, opinions could easily reach consensus. Based on the above experimental results, a culture-policy-driven mechanism for the opinion dynamic is worth promoting in this paper, that is, opinion dynamics can be driven by different social cultures and policies through the influence of heredity and variation in interpersonal relationship networks. This finding is of great significance for predicting opinion evolution under different acquaintance networks and formulating reasonable policies based on cultural characteristics to guide public opinion.
Intelligent control of power sharing between parallel-connected boost converters in micro-girds
Authors: Moosavi Kh. , Vahidi B. , Askarian Abyaneh H. , Foroughi Nematollahi A.
Published: November 2017

This paper presents an intelligent control strategy to improve power sharing between parallel-connected boost converters in micro-grids. Micro-grids contain renewable energy sources along power electronics to generate electricity. Due to the importance of renewable energy sources, connecting these sources with power electronics creates challenges. This paper presents one of these challenges and the method to solve it. The method is based on a recurrent artificial neural network that implements the well-known vector control strategy to determine the switching states of the pulse width modulation (PWM) based controlled boost converters optimally. Nested in the inner current control loop, the neural network based current controller tries to minimize the circulating current by reducing dq current errors and generates the dq voltage reference to derive PWM converters. This also results in the power difference between the converters. The simulation results using MATLAB/SIMULINK are provided to validate effectiveness of the proposed control strategy.
Analytical expression for the tunnel current through the redox-mediated tunneling contact in the case of the adiabatic electron transfer at one of the working electrodes and any possible type of the electron transfer at the other electrode
Authors: Medvedev Igor G.
Published: November 2017

We study the tunnel current through a one-level redox molecule immersed into the electrolyte solution for the case when the coupling of the molecule to one of the working electrodes is strong while it is arbitrary to the other electrode. Using the Feynman-Vernon influence functional theory and the perturbation expansion of the effective action of the classical oscillator coupled both to the valence level of the redox molecule and to the thermal bath representing the classical fluctuations of the polarization of the solvent, we obtain, following the canonical way, the Langevin equation for the oscillator. It is found that for the aqueous electrolyte solution, the damping and the stochastic forces which arise due to the tunnel current are much smaller than those due to the thermal bath and therefore can be neglected. We estimate the higher-order corrections to the effective action and show that the Langevin dynamics takes place in this case for arbitrary parameters of the tunneling junction under the condition of the strong coupling of the redox molecule to one of the working electrodes. Then the steady-state coordinate distribution function of the oscillator resulting from the corresponding Fokker-Planck equation is the Boltzmann distribution function which is determined by the adiabatic free energy surface arising from the mean current-induced force. It enables us to obtain the expression for the tunnel current in the case when the coupling of the redox molecule to one of the working electrodes is strong while it is arbitrary to the other electrode.
Implementing a 6-day physiotherapy service in rehabilitation: exploring staff perceptions
Authors: Caruana Erin L. , Kuys Suzanne S. , Clarke Jane , Brauer Sandra G.
Published: November 2017

Objective Australian weekend rehabilitation therapy provision is increasing. Staff engagement optimises service delivery. The present mixed-methods process evaluation explored staff perceptions regarding implementation of a 6-day physiotherapy service in a private rehabilitation unit. Methods All multidisciplinary staff working in the rehabilitation unit were surveyed regarding barriers, facilitators and perceptions of the effect of a 6-day physiotherapy service on length of stay (LOS) and patient goal attainment at three time points: before and after implementation, as well as after modification of a 6-day physiotherapy service. Descriptive statistics and thematic analysis was used to analyse the data. Results Fifty-one staff (50%) responded. Before implementation, all staff identified barriers, the most common being staffing (62%) and patient selection (29%). After implementation, only 30% of staff identified barriers, which differed to those identified before implementation, and included staff rostering and experience (20%), timing of therapy (10%) and increasing the allocation of patients (5%). Over time, staff perceptions changed from being unsure to being positive about the effect of the 6-day service on LOS and patient goal attainment. Conclusion Staff perceived a large number of barriers before implementation of a 6-day rehabilitation service, but these did not eventuate following implementation. Staff perceived improved LOS and patient goal attainment after implementation of a 6-day rehabilitation service incorporating staff feedback. What is known about this topic? Rehabilitation weekend services improve patient quality of life and functional independence while reducing LOS. What does this study add? Staff feedback during implementation and modification of new services is important to address potential barriers and ensure staff satisfaction and support. What are the implications for practitioners? Staff engagement and open communication are important to successfully implement a new service in rehabilitation.
Protein dietary efficiency and methane emission in cattle fed soybean meal treated with tannins
Authors: Mezzomo R. , Paulino P. V. R. , Barbosa M. M. , Martins T. S. , Pereira L. G. R. , Silva J. C. , Paulino M. F. , Silva M. C. , Serão N. V.
Published: November 2017

Adding tannins to the dietary protein source will cause complexation between the tannin and protein, which may increase dietary ruminal undegraded protein. Thus, this study aimed to evaluate the effects of replacing soybean meal (SM) with soybean meal treated with tannin (SMT) on the intake, partial and total nutrient digestibility, and protein dietary efficiency of young cattle fed a high-concentrate diet. Five Nellore bulls with bodyweights of 290 ± 11.2 kg were fitted with ruminal and abomasal cannulas and were used in the study. The experimental diets included 7.5% SM, with a proportion of that SM (0%, 33%, 66% or 100%) replaced with SMT. Another treatment (SMT+urea) with only 2.5% SM treated with tannins was tested. The intake of ether extract and the intake of neutral detergent fibre ash and protein were the only parameters related to feed intake that were affected by the replacement of SM with SMT. Ruminal and intestinal digestibility each showed a linear effect on crude protein, which decreased with ruminal digestibility and increased with intestinal digestibility. The intake of ruminal undegraded protein and metabolisable protein showed a positive linear correlation with the amount of SMT in the diet. SMT substitution showed no effect on methane emission. The replacement of traditional SM with SM treated with 2.5% tannins (85% condensed tannins and 15% hydrolysable tannins) for cattle that were fed high-concentrate diets showed increased amounts of metabolisable protein and decreased nitrogen loss per unit of crude protein, without changing the methane emission.
155 Oocyte Maturation in Lyophilized In Vitro Maturation Medium as a Method to Increase the Medium’s Shelf-Life
Authors: Rubessa M. , Weisgerber D. , Bessler S. , Bertels J. , Harley B. , Wheeler M.
Published: November 2017

The in vitro production of bovine embryos has dramatically increased in recent years, and with it the demand of stable media with a long shelf-life. In this experiment we evaluated the impact of the freeze-dried in vitro maturation (IVM) medium (Mdry) on in vitro oocyte maturation. We compared the standard IVM and the Mdry media. Medium M199 was used as base for the IVM medium. The percentage of metaphase II oocytes and embryo production were evaluated. Media solutions (10 mL) were aliquoted into 50-mL conical tubes and lyophilized to form a powder concentrate using a Genesis freeze-dryer (VirTis, Gardener, NY, USA). Lyophilization consisted of a constant cooling from 20°C to –10°C at a constant rate of 1°C/min with a 2-h hold at –10°C before sublimation at 0°C. The Mdry medium was held at –80°C for 4 months (only serum and hormones were added before the incubation). When the IVM medium was rehydrated, the pH were adjusted to 7.4. The percentage of mature oocytes was evaluated after 24 h of maturation. The oocytes were stained with Hoechst 33342, and only oocytes with metaphase and a polar body were evaluated as matured. Abattoir-derived Holstein oocytes (n = 540) were in vitro matured (25–30/well in 400 µL) and fertilized with sexed semen, according to standard procedures (Rubessa et al. 2011 Theriogenology 76, 1347-1355). The oocytes were split for analysis (432 were used for IVP and 108 for maturation rate) over 6 replicates. Twenty hours after IVF, presumptive zygotes were cultured in SOF medium at 39°C with 5% CO2, 7% O2, and 88% N2. On Day 7, embryo yields were assessed. All recorded parameters were subjected to a Student’s t-test. The parameters compared were maturation rate, cleavage rate, blastocyst rate and the percentage of embryos cleaved. The α level was set at 0.05. All data were expressed as quadratic means and mean standard deviations. The results showed no differences between the 2 groups (75.9% v. 74.1%) (t = 0.37; SD = 12.69; P = 0.36; df = 5) when we compared the nuclear maturation; however, when we evaluated embryo production, we found the Mdry treatment had a higher cleavage percentage (t = 2.39; SD = 14.81; P = 0.02; df = 5) and total embryos produced (t = 2.49; SD = 5.6; P = 0.02; df = 5) compared with the control (Table 1.). These results showed that lyophilization can be a valid method to increase the shelf life of IVP media. More replicates must be done in order to understand why the freeze-dried media produced more embryos.

Table 1.Mean (SD in parentheses) percentage cleavage and blastocysts
Hydrophobicity of proteins and nanostructured solutes is governed by topographical and chemical context
Authors: Xi Erte , Venkateshwaran Vasudevan , Li Lijuan , Rego Nicholas , Patel Amish J. , Garde Shekhar
Published: November 2017

Significance

Numerous biological self-assembly processes, from protein folding to molecular recognition, are driven by hydrophobic interactions, yet characterizing hydrophobicity at the nanoscale has remained a major challenge, because it requires understanding of the strength of protein–water interactions and the ease with which they can be disrupted. Water near a protein responds to its chemistry and topography in a manner that is collective and complex and cannot be captured by commonly used surface area models or hydropathy scales. We demonstrate that water density fluctuations near proteins can characterize protein hydrophobicity and reveal its dependence on curvature and chemical patterns at the nanoscale. Our approach opens new avenues for understanding and efficient characterization of biomolecular interactions.
Histone methyltransferase MMSET promotes AID-mediated DNA breaks at the donor switch region during class switch recombination
Authors: Nguyen Hai Vu , Dong Junchao , Panchakshari Rohit A. , Kumar Vipul , Alt Frederick W. , Bories Jean-Christophe
Published: November 2017

Significance

Activated B lymphocytes produce different classes of antibodies that target specific pathogens. During this process, DNA double-strand breaks (DSBs) are generated at precise regions of the Ig gene and are joined by the classical nonhomologous end joining (C-NHEJ) pathway to allow class switch recombination (CSR). Defects occurring in these mechanisms are associated with impaired antibody diversification, genomic instability, and cancer. Here, we show that deletion of multiple myeloma SET domain (MMSET), a histone methyltransferase that is deregulated in various lymphoid malignancies, reduces DNA cleavage at the upstream Ig gene region without affecting joining of DSBs by the C-NHEJ pathway. These findings show an important role for the histone methyltransferase activity of MMSET in promoting activation-induced cytidine deaminase-mediated DNA breaks during CSR.
Evidence for rRNA 2′-O-methylation plasticity: Control of intrinsic translational capabilities of human ribosomes
Authors: Erales Jenny , Marchand Virginie , Panthu Baptiste , Gillot Sandra , Belin Stéphane , Ghayad Sandra E. , Garcia Maxime , Laforêts Florian , Marcel Virginie , Baudin-Baillieu Agnès , Bertin Pierre , Couté Yohann , Adrait Annie , Meyer Mélanie , Therizols Gabriel , Yusupov Marat , Namy Olivier , Ohlmann Théophile , Motorin Yuri , Catez Frédéric , Diaz Jean-Jacques
Published: November 2017

Significance

Translational control is a cornerstone of gene-expression regulation in physiological and pathological contexts. The contribution of nonribosomal factors, including messenger RNAs (mRNAs) and mRNA-bound factors, to translational control have been extensively studied. Recently, the hypothesis of a ribosome-mediated regulation emerged, which proposes that cells produce ribosomes of different composition and displaying different translational properties. This work reveals that ribosomal RNA 2′-O-methylation can be modulated in human ribosomes, including at key functional sites for translation, and that changes in the 2′-O-methylation pattern control the intrinsic capabilities of ribosomes to translate mRNAs. This work directly demonstrates the existence of composition-modified ribosomes and their associated change in translational activity as conceptualized by the specialized ribosome concept.
Dynamics and control of gold-encapped gallium arsenide nanowires imaged by 4D electron microscopy
Authors: Chen Bin , Fu Xuewen , Tang Jau , Lysevych Mykhaylo , Tan Hark Hoe , Jagadish Chennupati , Zewail Ahmed H.
Published: November 2017

Significance

Imaging chemical/physical reaction dynamics at nanoscale interfaces of a composite nanostructure requires resolutions in both space and time. Using single-pulse methodology, we directly and visually capture the irreversible eutectic-related phase reactions of a single, same metal/semiconductor nanowire at nanometer–nanosecond spatiotemporal resolution by 4D electron microscopy. With a nondestructive free-standing sample preparation free from environmental disturbance that is important for statistical investigation, we have both qualitatively and quantitatively elucidated the transient phase reactions and obtained important physical properties of the newly formed phases, such as latent heat and specific heat. Our work provides an efficient way of quantitatively determining physical properties of a nanoscale object with a tiny small quantity, especially when not available in bulk counterparts.
Active turbulence in a gas of self-assembled spinners
Authors: Kokot Gašper , Das Shibananda , Winkler Roland G. , Gompper Gerhard , Aranson Igor S. , Snezhko Alexey
Published: November 2017

Significance

Turbulent fluid motion is widespread in nature and is observed across diverse length and time scales, ranging from high-Reynolds number hydrodynamics to active fluids, such as bacterial suspensions and cytoskeletal extracts. It is recognized as one of the unsolved challenges in theoretical physics. Here, we explore out-of-equilibrium magnetic colloidal particles at liquid interfaces that exhibit complex collective behavior, resulting in emergence of an active spinner phase. Self-assembled spinners (active spinning without self-propulsion) induce vigorous vortical flows, demonstrating the properties of a 2D hydrodynamic turbulence. Our findings provide insight into the behavior of active spinner liquids and ways to control the collective dynamics and transport in active colloidal materials.
Transcriptome-wide characterization of human cytomegalovirus in natural infection and experimental latency
Authors: Cheng Shu , Caviness Katie , Buehler Jason , Smithey Megan , Nikolich-Žugich Janko , Goodrum Felicia
Published: November 2017

Significance

Herpesviruses have an extraordinarily complex relationship with their host, persisting for the lifetime of the host by way of a latent infection. Reactivation of replication is associated with significant disease risk, particularly in immunocompromised individuals. We characterize in depth transcriptional profiles of human cytomegalovirus latency. We show that a broad and concordant viral transcriptome is found in both an experimental model of latency and in asymptomatically infected individuals. We further define genes that are differentially regulated during latent and replicative states: candidates for key regulators controlling the switch between latency and reactivation. This work will help understand the persistence of complex DNA viruses and provides a path toward developing antiviral strategies to control herpesvirus entry into and exit from latency.
EMT programs promote basal mammary stem cell and tumor-initiating cell stemness by inducing primary ciliogenesis and Hedgehog signaling
Authors: Guen Vincent J. , Chavarria Tony E. , Kröger Cornelia , Ye Xin , Weinberg Robert A. , Lees Jacqueline A.
Published: November 2017

Significance

Breast cancer is one the most common cancers and causes of cancer-related death worldwide. Tumor recurrence following therapy is attributed to a subset of tumor-initiating cells (TICs) with stem cell (SC) properties. Similar to normal adult SCs that drive tissue regeneration, TICs regenerate tumors after treatment and thereby enable dissemination throughout the body. Thus, a better appreciation of the mechanisms that induce and maintain SCs in normal and neoplastic tissues is critical for understanding normal tissue regeneration and improving breast cancer therapy. Here we show that key developmental epithelial–mesenchymal transition programs promote stemness of mammary SCs by inducing primary ciliogenesis and Hedgehog signaling. These results provide insights into intraepithelial and intratumoral heterogeneity that have an impact on certain breast cancers.
Nature and origins of the lexicon in 6-mo-olds
Authors: Bergelson Elika , Aslin Richard N.
Published: November 2017

Significance

Infants start understanding words at 6 mo, when they also excel at subtle speech–sound distinctions and simple multimodal associations, but don’t yet talk, walk, or point. However, true word learning requires integrating the speech stream with the world and learning how words interrelate. Using eye tracking, we show that neophyte word learners already represent the semantic relations between words. We further show that these same infants’ word learning has ties to their environment: The more they hear labels for what they’re looking at and attending to, the stronger their overall comprehension. These results provide an integrative approach for investigating home environment effects on early language and suggest that language delays could be detected in early infancy for possible remediation.
Superhydrophobic diving flies (
Ephydra hians
) and the hypersaline waters of Mono Lake
Authors: van Breugel Floris , Dickinson Michael H.
Published: November 2017

Significance

Superhydrophobic surfaces have been of key academic and commercial interest since the discovery of the so-called lotus effect in 1977. The effect of different ions on complex superhydrophobic biological systems, however, has received little attention. By bringing together ecology, biomechanics, physics, and chemistry our study provides insight into the ion-specific effects of wetting in the presence of sodium carbonate and its large-scale consequences. By comparing the surface structure and chemistry of the alkali fly—an important food source for migrating birds—to other species we show that their uniquely hydrophobic properties arise from very small physical and chemical changes, thereby connecting picoscale physics with globally important ecological impacts.
Cholesterol-binding site of the influenza M2 protein in lipid bilayers from solid-state NMR
Authors: Elkins Matthew R. , Williams Jonathan K. , Gelenter Martin D. , Dai Peng , Kwon Byungsu , Sergeyev Ivan V. , Pentelute Bradley L. , Hong Mei
Published: November 2017

Significance

Cholesterol is important for membrane protein function, but cholesterol-binding structures of membrane proteins are difficult to determine by X-ray crystallography and electron microscopy due to the small size and dynamic nature of cholesterol. We have developed a solid-state NMR approach to determine the cholesterol-binding structure of membrane proteins in lipid bilayers. Applied to the influenza M2 protein, the measured interatomic distances and cholesterol orientational angles indicate that cholesterol binds M2 in a substoichiometric fashion, flanking methyl-rich transmembrane (TM) residues near an amphipathic helix, without requiring a cholesterol recognition sequence motif, and this substoichiometric binding uniquely correlates with membrane curvature generation. These results give unprecedented insights into how cholesterol clusters M2 to the neck of the budding virus to mediate membrane scission.