bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elementary teachers' science knowledge and instructional practices: Impact of an intervention focused on english language learners
Authors: Lee Okhee , Llosa Lorena , Jiang Feng , Haas Alison , O'Connor Corey , Van Booven Christopher D. 
Published: February 2016

AbstractAs part of a three‐year curricular and professional development intervention focused on English language learners (ELLs), this study examined the intervention's effect on teachers' science knowledge and instructional practices after one year of implementation. The P‐SELL (Promoting Science Among English Language Learners) intervention comprised curriculum materials for students and teachers and teacher professional development workshops during the summer and throughout the school year. Using a cluster randomized controlled trial design, the study involved 103 fifth grade teachers from 33 treatment schools and 116 fifth grade teachers from 33 control schools across three school districts in one state. The teachers completed a researcher‐developed science test and a questionnaire about their instructional practices at the beginning and end of the year. Results indicated a positive effect of the P‐SELL intervention on teachers' science knowledge and all four measures of instructional practices: teaching for understanding, teaching for inquiry, language development strategies, and home language use. This positive effect could be attributed to consistent implementation of the key features of the intervention (i.e., standards‐based, inquiry‐oriented, and language‐focused) for all students and ELLs in particular through educative curriculum materials and professional development. © 2016 Wiley Periodicals, Inc. J Res Sci Teach 53: 579–597, 2016
State‐specific multireference perturbation theory: development and present status
Authors: Chattopadhyay Sudip , Chaudhuri Rajat K , Mahapatra Uttam Sinha , Ghosh Anirban , Ray Suvonil Sinha 
Published: February 2016

The state‐specific multireference perturbation theory (SSMRPT), which provides one state at a time may now gradually become a new useful ab initio tool for studying electronic states with strong configurational quasidegeneracy owing primarily to its suitability toward numerical implementation in the presence of intruders and also to a great extent for its firm theoretical construct and the scope of a systematic and hierarchical improvement. The method works with a complete active space, and treats each of the model space functions on the same footing by exploiting Jeziorski–Monkhorst parametrization of the wavefunction. The SSMRPT is size‐extensive and size‐consistent (with the orbitals localized). The real challenge remains in developing MRPT methods capable of maintaining explicit size‐extensivity and avoiding intruders over a vast range of molecular geometries. Recently developed relativistic SSMRPT for the four‐component spinors is very promising to describe the near‐degenerate states of molecules containing heavy atoms. The analysis of the formal aspects and practical utility of the SSMRPT method vis‐à‐vis the other MRPT formalisms that bear kinship with the SSMRPT formulation is also presented. Illustrative results show high accuracy of the SSMRPT method in describing quasidegenerate situations such as those appearing when one or more covalent bonds in the molecule become stretched or broken. While actively pursuing SSMRPT method, it became apparent to us that this method encounters two major limitations: (1) the scaling of the computational cost with respect to the number of active orbitals and (2) the lack of invariance of the energy with respect to a unitary transformation of the active orbitals. The future will tell whether the SSMRPT method will be able to acquire the same faith as other widely used single‐root MRPT methods. WIREs Comput Mol Sci 2016, 6:266–291. doi: 10.1002/wcms.1248This article is categorized under:

Electronic Structure Theory > Ab Initio Electronic Structure Methods
Nanoparticle formulations of cisplatin for cancer therapy
Authors: Duan Xiaopin , He Chunbai , Kron Stephen J. , Lin Wenbin 
Published: February 2016

The genotoxic agent cisplatin, used alone or in combination with radiation and/or other chemotherapeutic agents, is an important first‐line chemotherapy for a broad range of cancers. The clinical utility of cisplatin is limited both by intrinsic and acquired resistance and dose‐limiting normal tissue toxicity. That cisplatin shows little selectivity for tumor versus normal tissue may be a critical factor limiting its value. To overcome the low therapeutic ratio of the free drug, macromolecular, liposomal, and nanoparticle drug delivery systems have been explored toward leveraging the enhanced permeability and retention effect and promoting delivery of cisplatin to tumors. Here, we survey recent advances in nanoparticle formulations of cisplatin, focusing on agents that show promise in preclinical or clinical settings. WIREs Nanomed Nanobiotechnol 2016, 8:776–791. doi: 10.1002/wnan.1390This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Coaxial electrospun fibers: applications in drug delivery and tissue engineering
Authors: Lu Yang , Huang Jiangnan , Yu Guoqiang , Cardenas Romel , Wei Suying , Wujcik Evan K. , Guo Zhanhu 
Published: February 2016

Coelectrospinning and emulsion electrospinning are two main methods for preparing core–sheath electrospun nanofibers in a cost‐effective and efficient manner. Here, physical phenomena and the effects of solution and processing parameters on the coaxial fibers are introduced. Coaxial fibers with specific drugs encapsulated in the core can exhibit a sustained and controlled release. Their exhibited high surface area and three‐dimensional nanofibrous network allows the electrospun fibers to resemble native extracellular matrices. These features of the nanofibers show that they have great potential in drug delivery and tissue engineering applications. Proteins, growth factors, antibiotics, and many other agents have been successfully encapsulated into coaxial fibers for drug delivery. A main advantage of the core–sheath design is that after the process of electrospinning and release, these drugs remain bioactive due to the protection of the sheath. Applications of coaxial fibers as scaffolds for tissue engineering include bone, cartilage, cardiac tissue, skin, blood vessels and nervous tissue, among others. A synopsis of novel coaxial electrospun fibers, discussing their applications in drug delivery and tissue engineering, is covered pertaining to proteins, growth factors, antibiotics, and other drugs and applications in the fields of bone, cartilage, cardiac, skin, blood vessel, and nervous tissue engineering, respectively.WIREs Nanomed Nanobiotechnol2016, 8:654–677. doi: 10.1002/wnan.1391This article is categorized under:Implantable Materials and Surgical Technologies > Nanomaterials and ImplantsImplantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and ReplacementImplantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery
RNA recognition by Roquin in posttranscriptional gene regulation
Authors: Schlundt Andreas , Niessing Dierk , Heissmeyer Vigo , Sattler Michael 
Published: February 2016

Posttranscriptional regulation of gene expression plays a central role in the initiation of innate and adaptive immune responses. This is exemplified by the protein Roquin, which has attracted great interest during the past decade owing to its ability to prevent autoimmunity. Roquin controls T‐cell activation and T helper cell differentiation by limiting the induced expression of costimulatory receptors on the surface of T cells. It does so by recognizing cis regulatory RNA‐hairpin elements in the 3′ UTR of target transcripts via its ROQ domain—a novel RNA‐binding fold—and triggering their degradation through recruitment of factors that mediate deadenylation and decapping. Recent structural studies have revealed molecular details of the recognition of RNA hairpin structures by the ROQ domain. Surprisingly, it was found that Roquin mainly relies on shape‐specific recognition of the RNA. This observation implies that a much broader range of RNA motifs could interact with the protein, but it also complicates systematic searches for novel mRNA targets of Roquin. Thus, large‐scale approaches, such as crosslinking and immunoprecipitation or systematic evolution of ligands by exponential enrichment experiments coupled with next‐generation sequencing, will be required to identify the complete spectrum of its target RNAs. Together with structural analyses of their binding modes, this will enable us to unravel the intricate complexity of 3′ UTR regulation by Roquin and other trans‐acting factors. Here, we review our current understanding of Roquin–RNA interactions and their role for Roquin function. WIREs RNA 2016, 7:455–469. doi: 10.1002/wrna.1333This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Recognition
RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
RNA Turnover and Surveillance > Regulation of RNA Stability
CONSISTENT YIELD CURVE PREDICTION
Authors: Teichmann Josef , Wüthrich Mario V. 
Published: February 2016

AbstractWe present an arbitrage-free non-parametric yield curve prediction model which takes the full discretized yield curve data as input state variable. Absence of arbitrage is a particularly important model feature for prediction models in case of highly correlated data as, for instance, interest rates. Furthermore, the model structure allows to separate constructing the daily yield curve from estimating its volatility structure and from calibrating the market prices of risk. The empirical part includes tests on modeling assumptions, out-of-sample back-testing and a comparison with the Vasiček (1977) short-rate model.
Control of trailing-edge separation by tangential blowing inside the bubble
Authors: Viswanath P. R. , Madhavan K. T. 
Published: February 2016

AbstractExperiments have been performed investigating the effectiveness of steady tangential blowing, with the blowing slot located downstream of separation (but inside the separation bubble) to control a trailing-edge separated flow at low speeds. Trailing-edge separation was induced on a two-dimensional aerofoil-like body and the shear layer closure occurred in the near-wake. Measurements made consisted of model surface pressures and mean velocity, turbulent shear stress and kinetic energy profiles in the separated zone using a two-component LDV system. It is explicitly demonstrated that the novel concept of tangential blowing inside the bubble can be an effective means of control for trailing-edge separated flows as well. Blowing mass and momentum requirements for the suppression of wall and wake flow reversals have been estimated.
Investigation of active control of swept shock wave/turbulent boundary-layer interactions – PSP results
Authors: Couldrick J. S. , Gai S. L. , Milthorpe J. F. , Shankar K. 
Published: February 2016

AbstractAn investigation of active control of the swept shock wave/boundary-layer interaction using ‘smart’ flap actuators is presented. The actuators are manufactured by bonding piezoelectric material to an inert substrate to control the bLeed/suction rate through a plenum chamber. The cavity provides communication of signals across the shock, allowing rapid thickening of the boundary layer approaching the shock. This splits the shock foot into a series of weaker shocks forming a lambda structure, thus reducing wave drag. Active control allows optimisation of the unimorph deflection, hence rate of mass transfer.In this paper, results of the interaction using pressure sensitive paint (PSP) are emphasised. It is shown that the use of PSP, in conjunction with discrete pressure data, enables the main features of the interaction to be observed when the actuators are subject to different deflections.
Wind-tunnel interference effects on a 70° delta wing
Authors: Allan M. R. , Badcock K. J. , Barakos G. N. , Richards B. E. 
Published: February 2016

AbstractThis paper considers the effects of both wind-tunnel walls and a downstream support structure, on the aerodynamics of a 70° delta wing. A RANS model of the flow was used with the wind-tunnel walls and supports being modelled with inviscid wall boundary conditions. A consistent discretisation of the domain was employed such that grid dependence effects were consistent in all solutions, thus any differences occurring were due to varying boundary conditions (wall and support locations). Comparing solutions from wind-tunnel simulations and simulations with farfield conditions, it has been shown that the presence of tunnel walls moves the vortex breakdown location upstream. It has also been seen that vortex strength, helix angle, and mean incidence also increase, leading to a more upstream breakdown location in wind-tunnels. The secondary separation line was also observed to move outboards. It was observed that for high Reynolds numbers, with a support downstream of the wing, vortex breakdown can be delayed due to blockage effects providing the vortices do not impinge on the support This was observed to be the case for smaller supports also.
Induced-drag reduction of wing–wings and wings–ground configurations
Authors: Marino L. 
Published: February 2016

AbstractThe problem of induced drag reduction during formation flight is revisited by means of a simple aerodynamic model based on lifting line theory. The optimum configuration for minimum induced drag is analysed both in and out of the ground effect and the influence of the main geometrical and aerodynamic parameters is considered. The results are discussed and compared with existing numerical and experimental data.
Effects of hydrogen–air non–equilibrium chemistry on the performance of a model scramjet thrust nozzle
Authors: Stalker R. J. , Truong N. K. , Morgan R. G. , Paull A. 
Published: February 2016

AbstractTwo aspects of hydrogen-air non-equilibrium chemistry related to scramjets are nozzle freezing and a process called ‘kinetic afterburning’ which involves continuation of combustion after expansion in the nozzle. These effects were investigated numerically and experimentally with a model scramjet combustion chamber and thrust nozzle combination. The overall model length was 0·5m, while precombustion Mach numbers of 3·1±0·3 and precombustion temperatures ranging from 740K to 1,400K were involved. Nozzle freezing was investigated at precombustion pressures of 190kPa and higher, and it was found that the nozzle thrusts were within 6% of values obtained from finite rate numerical calculations, which were within 7% of equilibrium calculations. When precombustion pressures of 70kPa or less were used, kinetic afterburning was found to be partly responsible for thrust production, in both the numerical calculations and the experiments. Kinetic afterburning offers a means of extending the operating Mach number range of a fixed geometry scramjet.
Investigation into clustering of synthetic jet actuators for flow separation control applications
Authors: Liddle S. C. , Wood N. J. 
Published: February 2016

AbstractAn investigation into the behaviour of clustered synthetic jet Actuators for flow-control applications is described. Experiments have been undertaken with two small-scale synthetic jet actuators in a zero-pressure gradient boundary-layer, in order to investigate the effect of configuration yaw angle and relative input signal phase. Oil-flow visualisation and hotwire anemometry techniques were used, demonstrating that changes in the downstream flow structure could be observed. Compared to a streamwise configuration, in which a symmetrical counter-rotating vortex pair was produced by the synthetic jet-boundary-layer interaction, a broader asymmetric interaction was produced in a 15° yaw configuration. Streamwise velocity contour plots, illustrating the development of the interaction downstream, over four phase angles, were presented. Significant differences in the PSD analyses of downstream streamwise velocity time histories were found, suggesting that input signal phase could influence the stability and hence effectiveness of flow structures used in flow-control applications.
The Vortex Merger Factor in Aircraft Wake Turbulence
Authors: Mokry Miroslav 
Published: February 2016

AbstractVortex merger is studied within the context of two-dimensional discrete vortex sheets and demonstrated on two equally oriented circular vortices and aircraft tip and flap vortices. It is confirmed that, depending on the wing load distribution, the latter may or may not coalesce into a single counter-rotating pair. The interaction of a vortex with an equally oriented shear layer, governed by the same physical principle, suggests a possible intensification of an aircraft vortex in cross-wind shear.
2D numerical study of circular synthetic jets in quiescent flows
Authors: Tang H. , Zhong S. 
Published: February 2016

Abstract2D numerical simulations of flows generated by a synthetic jet actuator with a circular orifice were conducted at two different diaphragm displacement settings, one representing a typical laminar case and the other a fully turbulent case. The flow in the cavity was included in the computation in order to provide more accurate predictions. A velocity boundary condition was applied at the neutral position of the diaphragm to account for its temporal deformation. Comparisons were made between the computational results and existing PIV and hot-wire data in terms of the time sequence of the velocity vector field, velocity variations in space and with time. It is found that computational results for the laminar case agree well with the experimental data. Four turbulent models were tested for the fully turbulent case. It was found that the predictions using the RNG κ-ε and Standard k-ε models were reasonably close to the experimental data. This initial study has produced some encouraging evidence for the capacity of FLUENT in simulating the key features of synthetic jets.
Industry applications of advanced flow diagnostics experience in the BAE Systems ground effects rig
Authors: Curtis P. 
Published: February 2016

AbstractThis paper reviews some of the work performed on the ground effects rig at BAE Systems in Warton, the now unique facility for modelling dynamic vertical landings and measuring hot gas ingestion. The paper discusses the flow diagnostic tools which have been used in recent times, up to the complexity of 3D PIV, and uses examples from the F-35 JSF programme to illustrate these. The paper hopefully demonstrates the difficulties of using these tools, as well as the benefits they can bring to a development programme.The ground effects rig is a facility designed to measure temperature rise in aircraft intakes during vertical manoeuvres close to the ground. It is a complex facility that comes as close as possible to accurately modelling the flowfields around an aircraft moving both vertically and horizontally near the ground, with the ability to model dynamic pitch and roll at the same time.Standard instrumentation for the models consists of rapid response thermocouples mounted in a rake at the engine face. 45 thermocouples of 0·05mm diameter with a time constant of about 10ms are used.Although, with its standard instrumentation, the rig can measure how much hot gas gets to the engine face, it doesn’t show how it got there, or where it came from, which is the knowledge required to improve the design. Hence there is a need for flow diagnostics.
Jet thrust vectoring using a miniature fluidic oscillator
Authors: Raman G. , Packiarajan S. , Papadopoulos G. , Weissman C. , Raghu S. 
Published: February 2016

AbstractThis paper presents a new approach to vectoring jet thrust using a miniature fluidic actuator that provided spatially distributed mass addition. The fluidic actuators used had no moving parts and produced oscillatory flow with a square wave form at frequencies up to 1·6kHz. A subsonic jet with an exit diameter of 3·81cm was controlled using single and dual fluidic actuators, each with an equivalent circular diameter of 1·06mm. The fluidic nozzle was operated at pressures between 20·68 and 165·47kPa. The objectives of the present work included documentation of the actuation characteristics of fluidic devices, assessment of the effectiveness of fluidic devices for jet thrust vectoring, and evaluation of mass flow requirements for vectoring under various conditions. Measurements were made in the flow field using a pitot probe for the vectored and unvectored cases. Some acoustic measurements were made using microphones in the near-field and for selected cases particle image velocimetry (PIV) measurements were made. Thrust vectoring was obtained in low speed jets by momentum effects with fluidic device mass flow rates of only 2 × 10–4kg/sec (0·6% of main jet mass flow per fluidic oscillator). Although a single fluidic device produced vectoring of the primary jet, the dual fluidic device configuration (with two fluidic devices on either side of the jet exit) produced mass flux enhancement of 28% with no vectoring. Our results indicate that fluidic actuators have the potential for use in thrust vectoring, flow mixing and industrial flow deflection applications.
Simulation and flight test of a temperature sensing stabilisation system
Authors: Herrmann P. , Bil C. 
Published: February 2016

AbstractThermopile sensors detect electromagnetic radiation as a function of the object’s temperature. Because there is a temperature difference between the cold ground and the warm sky, these sensors could be used to detect the horizon and thus be used as a reference to stabilise a small aircraft, such as an unmanned aerial vehicle (UAV) in visual meteorological conditions (VMC). To verify this hypothesis, a system has been developed providing horizon detection using thermopile sensors to stabilise an R/C model aircraft. The aircraft has gone through a number of flight trials using remote control to enable and disable the stabilisation system. During the flight trials the aircraft was set at various attitudes when the system was enabled. The stabilisation system was able to assume wing level under various bank angles and weather conditions with minimum overshoot and oscillation.Although the system shows good performance during flight trials, most of the original design was done using trial and error. A design tool was needed to implement further improvements to the system and to efficiently implement it on other aircraft. This required a good understanding of the physical behaviour of the system and the interaction between the sensors, aircraft and the environment. A mathematical model of the overall system was developed using the MATLAB/Simulink environment to simulate the behaviour of the system under various conditions. The simulation results were then compared with actual flight experiments. This paper describes the modelling techniques used for the different system components and the results of the simulation compared to actual flight trials.