bluuebunny/crossref_metadata_2025 huggingface dataset:
Photosynthesis and photosynthetic efficiencies along the terrestrial plant’s phylogeny: lessons for improving crop photosynthesis
Authors: Flexas Jaume , Carriquí Marc
Published: December 2019

Photosynthesis is the basis of all life on Earth. Surprisingly, until very recently, data on photosynthesis, photosynthetic efficiencies, and photosynthesis limitations in terrestrial land plants other than spermatophytes were very scarce. Here we provide an updated data compilation showing that maximum photosynthesis rates (expressed either on an area or dry mass basis) progressively scale along the land plant’s phylogeny, from lowest values in bryophytes to largest in angiosperms. Unexpectedly, both photosynthetic water (WUE) and nitrogen (PNUE) use efficiencies also scale positively through the phylogeny, for which it has been commonly reported that these two efficiencies tend to trade‐off between them when comparing different genotypes or a single species subject to different environmental conditions. After providing experimental evidence that these observed trends are mostly due to an increased mesophyll conductance to CO2 – associated with specific anatomical changes – along the phylogeny, we discuss how these findings on a large phylogenetic scale can provide useful information to address potential photosynthetic improvements in crops in the near future.
Functional organization of vestibulospinal inputs on thoracic motoneurons responsible for trunk postural control in Xenopus
Authors: Olechowski‐Bessaguet Anne , Grandemange Raphaël , Cardoit Laura , Courty Elric , Lambert François M. , Le Ray Didier
Published: December 2019

Key points

Vestibulospinal reflexes participate in postural control. How this is achieved has not been investigated fully.

We combined electrophysiological, neuroanatomical and imaging techniques to decipher the vestibulospinal network controlling the activation of back and limb muscles responsible for postural adjustments.

We describe two distinct pathways activating either thoracic postural motoneurons alone or thoracic and lumbar motoneurons together, with the latter co‐ordinating specifically hindlimb extensors and postural back muscles.

In vertebrates, trunk postural stabilization is known to rely mainly on direct vestibulospinal inputs on spinal axial motoneurons. However, a substantial role of central spinal commands ascending from lumbar segments is not excluded during active locomotion. In the adult Xenopus, a lumbar drive dramatically overwhelms the descending inputs onto thoracic postural motoneurons during swimming. Given that vestibulospinal fibres also project onto the lumbar segments that shelter the locomotor generators, we investigated whether such a lumbo‐thoracic pathway may relay vestibular information and consequently, also be involved in the control of posture at rest. We show that thoracic postural motoneurons exhibit particular dendritic spatial organization allowing them to gather information from both sides of the cord. In response to passive head motion, these motoneurons display both early and delayed discharges, with the latter occurring in phase with ipsilateral hindlimb extensor bursts. We demonstrate that both vestibulospinal and lumbar ascending fibres converge onto postural motoneurons, and that thoracic motoneurons monosynaptically respond to the electrical stimulation of either pathway. Finally, we show that vestibulospinal fibres project to and activate lumbar interneurons with thoracic projections. Taken together, our results complete the scheme of the vestibulospinal control of posture by illustrating the existence of a novel, indirect pathway, which implicates lumbar interneurons relaying vestibular inputs to thoracic motoneurons, and participating in global body postural stabilization in the absence of active locomotion.
Examination of Consistent Application of Interfacial Fracture Energy Versus Mode-Mixity Curve for Delamination Prediction
Authors: Samet David , Trilochan Rambhatla V. N. N. , Sitaraman Suresh K.
Published: December 2019

Experimentally characterized critical interfacial fracture energy is often written as an explicit trigonometric function of mode-mixity and is used to determine whether an interfacial crack will propagate or not under given loading conditions for an application. A different approach to assess whether an interfacial crack will propagate is to employ a failure locus consisting of the critical fracture energies corresponding to different fracture modes, represented by an implicit formulation. Such a failure locus can be linear, elliptical, among other shapes. As it is nearly impossible to obtain isolated GIc or GIIc values through experimentation, extrapolations are used to determine these two extreme values based on intermediate experimental data. However, the magnitude of these extreme values as well as the shape of the two forms of failure curves are at risk of being inconsistent should proper care not be taken. An example of such an inconsistency would be to use a trigonometric formulation to obtain the extreme values through extrapolation and then employ those values in simulation through an elliptical failure. In this work, we have employed a series of commonly used interfacial fracture energy measurement techniques over a range of mode-mixities for a metal/polymer interface to demonstrate the potential discrepancy in the two approaches and to underscore the need for a consistent approach in evaluating interfacial crack propagation.
Biaxial Stress Relaxation of Vaginal Tissue in Pubertal Gilts
Authors: Pack Erica , Dubik Justin , Snyder William , Simon Alexander , Clark Sherrie , De Vita Raffaella
Published: December 2019

Pelvic organ prolapse (POP) is a condition characterized by displacement of the vagina from its normal anatomical position leading to symptoms such as incontinence, physical discomfort, and poor self-image. Conservative treatment has shown limited success and surgical procedures, including the use of mesh, often lead to severe complications. To improve the current treatment methods for prolapse, the viscoelastic properties of vaginal tissue need to be characterized. We determined the biaxial stress relaxation response of vaginal tissue isolated from healthy pubertal gilts. Square specimens (n = 20) with sides aligned along the longitudinal directions (LD) and circumferential direction (CD) of the vagina were biaxially displaced up to 5 N. The specimens were then kept at the displacements corresponding to 5 N for 20 min in both the LD and CD, and the corresponding strains were measured using digital image correlation (DIC). The stresses in the LD and CD were found to decrease by 49.91 ± 5.81% and 46.22 ± 5.54% after 20 min, respectively. The strain in the LD and CD increased slightly from 0.080 ± 0.054 to 0.091 ± 0.064 and 0.050 ± 0.039 to 0.058 ± 0.047, respectively, but these changes were not significant (p > 0.01). By using the Peleg model, the initial decay rate and the asymptotic stress during stress relaxation were found to be significantly higher in the LD than in the CD (p≪0.001), suggesting higher stress relaxation in the LD. These findings may have implications for improving current surgical mesh, mechanical devices, and physical therapy used for prolapse treatment.
Investigating the Influence of MCP Uncertainties on the Energy Storage Capacity Requirements for Offshore Windfarms
Authors: Mifsud Michael D. , Farrugia Robert N. , Sant Tonio
Published: December 2019

Recent studies have shown that the intermittency of wind energy can be mitigated by means of an energy storage system (ESS). Energy can be stored during periods of low energy demand and high wind availability to then be utilised during periods of high energy demand. Measure-Correlate-Predict (MCP) methodologies are used to predict the wind speed and direction at a wind farm candidate site, hence enabling the estimation of the power output from the wind farm. Once energy storage is integrated with the wind farm, it is no longer only a matter of estimating the power output from the windfarm, but it is also important to model the behaviour of the ESS in conjunction with the energy demand. The latter is expected to depend, amongst other factors, on the reliability of the MCP methodology used.

This paper investigates how different MCP methodologies influence the projected time series behaviour and the capacity requirements of ESS systems coupled to offshore wind farms. The analysis is based on wind data captured by a LiDAR system installed at a coastal location and from the Meteorological Office at Malta International Airport in the Maltese Islands. Different MCP methodologies are used to generate wind speed and direction time series at a candidate offshore wind farm site for various array layouts. The latter are then used in WindPRO® to estimate the time series power production for each MCP methodology and wind farm layout. This is repeated with actual wind data, such that the percentage error in energy yield from each MCP methodology is quantified, and the more reliable methodology could be identified. While it is evident that the integration of storage will reduce the need for wind energy curtailment, the reliability of the MCP methodology used is found to be crucial for proper estimation of the behaviour of the ESS.
Research on Underwater Vehicle for Monitoring of Offshore Wind Generation Systems
Authors: Yamamoto Ikuo , Morinaga Akihiro , Lawn Murray
Published: December 2019

A compact low cost lightweight ROV (Remotely operated underwater vehicle) has been developed to assist in the monitoring of offshore wind generation systems. The ROV successfully dove 76 meters to check the condition of the spa to the base and associated moorings of a floating offshore wind generator (Goto, Nagasaki, Japan). An abundance of sea life was also observed around the base as the base provides a kind of artificial reef which fosters a marine ecosystem. The design philosophy of this ROV and overall system are described in this paper including the proposed addition of robotic arms.
Disparity Analysis for Three Floating Wind Turbine Aerodynamic Codes in Comparison
Authors: Sant Tonio , Micallef Daniel
Published: December 2019

This paper compares the predictions from three independent aerodynamic simulation tools modelling the time varying rotor thrust and shaft power of floating offshore wind turbines (FOWTs) under different sea wave conditions. These include a Blade-Element-Momentum (BEM) model, a Free-Wake Vortex model (FWM) and a Navier-Stokes based Actuator Disc (AD) model. The study is based on the NREL1 5 MW baseline FOWT installed on the OC4 DeepCWind semi-submersible platform. The rotor speed is maintained constant throughout the analysis, though different rotor tip speeds and sea wave heights and periods are considered. While the three aerodynamic models apply different approaches for modelling the wake, they are all based on a blade element theory (BET) approach for simulating the blade loads. A common set of static aerofoil data is used and corrections to the data for unsteady effects such as dynamic stall are ignored. Thus disparity between the predictions for the surging rotor is primarily due to the different numerical approaches used for modelling the FOWT wake. The time-averaged rotor thrust and power coefficients predicted by the three models were found to be in close agreement with one another at low tip speed ratios and the sea state was found to have marginal effect on these results. However, the disparity in such predictions between the three models was found to increase at high tip speed ratios, with the FWM and the AD models yielding the largest and smallest rotor thrust and power coefficients, respectively. Furthermore, the AD model was observed to exhibit the highest sensitivity to sea state, with a significant increase in the time averaged power coefficient being predicted at the most extreme wave condition.

The amplitudes in the thrust and power expressed as a percentage of the corresponding time-averaged values estimated by the three aerodynamic models were found to be in close agreement with one another for the optimal and high tip speed ratios. However, at low tip speed ratios, the BEM predictions were significantly smaller than those estimated by the FWM and AD models.
Numerical Modeling and Prediction of the Significant Parameters for Wind Monitoring
Authors: Radulescu Victorita
Published: December 2019

Romania has a high wind potential, representing more than 14,000 MW. After significant investments of over 5 billion euros made starting 2010, many wind farms were developed in regions with efficient potential, from the South-East part of the country. Nowadays, in January 2018, in Romania were registered 3025 MW produced by wind energy, representing around 30% of the total generated energy. To establish the efficient areas for future wind power plants a massive campaign of wind’s monitoring was developed, in the entire country. The paper presents a solution of the numerical modeling for the registered environmental data, significant atmospheric parameters. The complex realized database will allow future implementations of wind power plants. The data measured and stored refer at wind intensity and direction, pressure, temperature, humidity, solar radiation, and drew points, performed during four years with masts of height 70 m, situated at distance of 20 km each other. By numerical modeling is created a correlation and prediction of the measured data, plotted in correspondence to each elevation of the measuring stations. It was also analyzed the perturbations induced by the masts presence. Firstly, are mentioned some aspects referring to the masts installation, the solution adopted for a proper distribution through the analyzed area. The database elaboration was a challenge, due to the large amount of data recorded at intervals of 10 minutes (some parameters at 10 seconds) for a period of four years, for more than 12 parameters instantly. Besides these, there were stored and some other data referring at daily produced energy with some existent wind turbines. They will be considered as data input for future developments, with new generations of turbines, more efficient. It is created an original method to compact the database in order to use small amounts of computer memory. With the daily collected data was made and stored separately the average, maximum, and minimum wind velocity, for each day and month, from the measurements at time interval of 10 minutes. The relations between the values registered are within classification areas CL-4 and CL-8, allowing performing illustrations of over-prediction and under-prediction. The wind velocities under 4 m/s are stored in a separate folder because they are not useful in wind turbine functioning. These values are used only for estimation the future wind farms efficiency. The uncertainties are analyzed and are assessed the limits of errors, for the land classification CL-4. There are presented numerical results, some conclusions, and references.
Machine Learning-Aided Assessment of Wind Turbine Energy Losses due to Blade Leading Edge Damage
Authors: Cavazzini Anna , Minisci Edmondo , Campobasso M. Sergio
Published: December 2019

Estimating reliably and rapidly the losses of wind turbine annual energy production due to blade surface damage is essential for optimizing maintenance planning and, in the frequent case of leading edge erosion, assessing the need for protective coatings. These requirements prompted the development of the prototype system presented herein, using machine learning, wind turbine engineering codes and computational fluid dynamics to estimate wind turbine annual energy production losses due to blade leading edge damage. The power curve of a turbine with nominal or damaged blade surfaces is determined respectively with the open-source FAST and AeroDyn codes of the National Renewable Energy Laboratory, both using the blade element momentum theory for turbine aerodynamics. The loss prediction system is designed to map a given three-dimensional geometry of a damaged blade onto a damaged airfoil database, which, in this study, consists of 2700+ airfoil geometries, each analyzed with Navier-Stokes computational fluid dynamics over the working range of angles of attack. To avoid the need for lengthy aerodynamic analyses to assess losses due to damages monitored during turbine operation, the airfoil force data of a damaged turbine required by AeroDyn are rapidly obtained using a machine learning method trained using the pre-existing airfoil database. Presented results focus on the analysis of a utility-scale offshore wind turbine and demonstrate that realistic estimates of the annual energy production loss due to leading edge surface damage can be obtained in just a few seconds using a standard desktop computer, highlighting the viability and the industrial impact of this new technology for wind farm energy losses due to blade erosion.
Effect of Nacelle Drag on the Performance of a Floating Wind Turbine Platform
Authors: Son Daewoong , Louazel Pauline , Yu Bingbin
Published: December 2019

Wind forces acting on an offshore wind turbine are transferred to the bottom of the tower and consequently to the floating structure. Thus, drag forces acting on each component of the wind turbine such as the blades, the nacelle, and the tower must be accounted for properly in order to evaluate the performance of the supporting platform. In the aero-elastic wind turbine simulation tool FAST v.7, the nacelle drag component, however, has not been implemented, which means that only the drag forces on the tower and on the blades are represented. In this work, the front and side nacelle drag forces are modelled in FAST v.7 via different drag contributions. This paper will examine the behavior of a floating offshore semisubmersible platform, the WindFloat, for different Rotor-Nacelle-Assembly (RNA) yaw-misalignments with emphasis on the nacelle drag component.
Simulation of an Offshore Wind Turbine Using a Weakly-Compressible CFD Solver Coupled With a Blade Element Turbine Model
Authors: Elie Baptiste , Oger Guillaume , Le Touzé David
Published: December 2019

The present study addresses the first steps of development and validation of a coupled CFD-BE (Blade Element) simulation tool dedicated to offshore wind turbine farm modelling. The CFD part is performed using a weakly-compressible solver (WCCH). The turbine is taken into account using FAST (from NREL) and its effects are imposed into the fluid domain through an actuator line model. The first part of this paper is dedicated to the presentation of the WCCH solver and its coupling with the aero-elastic modules from FAST. In a second part, for validation purposes, comparisons between FAST and the WCCH-FAST coupling are presented and discussed. Finally, a discussion on the performances, advantages and limitations of the formulation proposed is provided.
Analysis of Environmental Conditions for the Conceptual Design of a 200 MW Floating Offshore Wind Farm in the East Sea, Korea
Authors: Shin Hyunkyoung , Yu Youngjae , Pham Thanh Dam , Ahn Hyeonjeong , Seo Byoungcheon , Kim Junbae
Published: December 2019

Due to global climate change, concern regarding the environment is greater than ever. Also, the energy industry is constantly developing and investing in new and renewable energy to reduce carbon emissions. Korea is planning to increase the proportion of renewable energy generation to 20% by 2030, in accordance with the 3020 renewable energy policy. This will involve 16.5 GW (34%) from wind energy, with a capacity from offshore wind energy of approximately 13 GW. Considering domestic technological wind resource potential (33.2 GW), it seems to be a sufficient target amount. However, in order to start the wind power generation business, the installation area must be analyzed for environmental information, for the evaluation of the wind resource and the early-stage concept design. Because it is difficult to conduct long-term measurements of the entire sea area, the environmental conditions are generally estimated from short-term measurement data and long-term reanalysis data. In this study, the environmental conditions of the East Sea of Korea were selected, and a comparative analysis was performed on the meteorological agency’s oceanic meteorology buoy data, ERA-5 reanalysis data obtained from ECMWF, and NASA’s MERRA-2 data. The extreme sea states of 50 years and 100 years were analyzed by extreme statistical analysis. Finally, environmental conditions required for the basic design of wind turbines were selected following IEC and DNV standards.
A Modified Free-Wake Vortex Ring Model for the Aerodynamics of Floating Offshore Wind Turbines
Authors: Dong Jing , Viré Axelle , Ferreira Simao , Li Zhangrui , van Bussel Gerard
Published: December 2019

A modified free-wake vortex ring model is proposed to compute the dynamics of a floating horizontal-axis wind turbine. The model is divided into two parts. The near wake model uses a blade bound vortex model and trailed vortex model, which is developed based on vortex filament method. By contrast, the far wake model is based on the vortex ring method. This is a good compromise between accuracy and computational cost. In this work, the model is used to assess the influence of floating platform motions on the performance of a horizontal-axis wind turbine rotor. The results are validated on the 5MW NREL rotor and compared with other vortex models for the same rotor subjected to different platform motions. It was found that the result from the proposed method are more reliable than the results from BEM theory especially at small angles of attack in the region of low wind speeds, on the one hand, and high wind speeds with blade pitch motions, on the other hand.
Design and Dynamic Analysis of a Compact 10 MW Medium Speed Gearbox for Offshore Wind Turbines
Authors: Wang Shuaishuai , R. Nejad Amir , Moan Torgeir
Published: December 2019

This paper presents the design of a compact gearbox for the DTU 10 MW reference offshore wind turbine. An innovative gearbox concept consisting of a fixed planetary stage with a differential compound epicyclic stage is proposed. Power splitting and compound epicyclic transmission technologies are employed, which could effectively reduce the gearbox’ size. Power transmission principle of the gearbox is described, and power distribution on two transfer paths is derived by the geometrical and mechanical relationships among the components. The gearbox is designed based on the design loads and criteria with reference to the relevant international standards, and all of the critical components, gears and bearings, are designed by performing fatigue limit state (FLS) check. A high fidelity drivetrain dynamic model, consisting of the compact gearbox and one four-point support drivetrain configuration, is established by means of multi-body system (MBS) approach. Then, validation of the power distribution is conducted by the comparison of the simulation results and design values. Resonance analysis of the drivetrain model is conducted by employing Campbell diagram, energy distribtuion of components and time domain simulation approach, and the results show that no resonance phenomenon appears in this drivetrain model during the normal operating conditions. In addition, load sharing performance of the MBS model is assessed, indicating the a favorable dynamic operating behavior of the gearbox. It is believed that such compact design could be good alternative for floating offshore wind turbines.
Experimental Validation of Angular Velocity Measurements for Wind Turbines Drivetrain Condition Monitoring
Authors: Moghadam Farid K. , R. Nejad Amir
Published: December 2019

Drivetrain bearings are seen as the most common reason of the wind turbine drivetrain system failures and the consequent downtimes. In this study, the angular velocity error function is used for the condition monitoring of the bearings and gears in the wind turbine drivetrain. This approach benefits from using the sensor data and the dedicated communication network which already exist in the turbine for performance monitoring purposes. Minor required modification includes an additional moderate sampling frequency encoder without any need of adding an extra condition monitoring system. The additional encoder is placed on the low speed shaft and can also be used as the backup for the high speed shaft encoder which is critical for turbine control purposes. A theory based on the variations of the energy of response around the defect frequency is suggested to detect abnormalities in the drivetrain operation. The proposed angular velocity based method is compared with the classical vibration-based detection approach based on axial/radial acceleration data, for the faults initiated by different types of excitation sources. The method is experimentally evaluated using the data obtained from the encoders and vibration sensors of an operational wind turbine.
Advanced Vibration Signal Processing Using Edge Computing to Monitor Wind Turbine Drivetrains
Authors: Peeters Cédric , Verstraeten Timothy , Nowé Ann , Daems Pieter-Jan , Helsen Jan
Published: December 2019

This paper illustrates an integrated monitoring approach for wind turbines exploiting this Industry 4.0 context. Our combined edge-cloud processing approach is documented. We show edge processing of vibration data captured on a wind turbine gearbox to extract diagnostic features. Focus is on statistical indicators. Real-life signals collected on an offshore turbine are used to illustrate the concept of local processing. The NVIDIA Jet-son platform serves as edge computation medium. Furthermore, we show an integrated failure detection and fault severity assessment at the cloud level. Health assessment and fault localization combines state-of-the-art vibration signal processing on high frequency data (10kHz and higher) with machine learning models to allow anomaly detection for each processing pipeline. Again this is illustrated using data from an offshore wind farm. Additionally, the fact that data of similar wind turbines in the farm is collected allows for exploiting system similarity over the fleet.
Do Older Adults With Reduced Bone Mineral Density Benefit From Strength Training? A Critically Appraised Topic
Authors: Zamoscinska Maja , Faber Irene R. , Büsch Dirk
Published: December 2019

Clinical Scenario:Reduced bone mineral density (BMD) is a serious condition in older adults. The mild form, osteopenia, is often a precursor of osteoporosis. Osteoporosis is a pathological condition and a global health problem as it is one of the most common diseases in developed countries. Finding solutions for prevention and therapy should be prioritized. Therefore, the critically appraised topic focuses on strength training as a treatment to counteract a further decline in BMD in older adults.Clinical Question:Is strength training beneficial in increasing BMD in older people with osteopenia or osteoporosis?Summary of Key Findings:Four of the 5 reviewed studies with the highest evidence showed a significant increase in lumbar spine BMD after strength training interventions in comparison with control groups. The fifth study confirmed the maintenance of lumbar spine density due to conducted exercises. Moreover, 3 reviewed studies revealed increasing BMD at the femoral neck after strength training when compared with controls, which appeared significant in 2 of them.Clinical Bottom Line:The findings indicate that strength training has a significant positive influence on BMD in older women (ie, postmenopausal) with osteoporosis or osteopenia. However, it is not recommended to only rely on strength training as the increase of BMD may not appear fast enough to reach the minimal desired values. A combination of strength training and supplements/medication seems most adequate. Generalization of the findings to older men with reduced BMD should be done with caution due to the lack of studies.Strength of Recommendation:There is grade B of recommendation to support the validity of strength training for older women in postmenopausal phase with reduced BMD.
DNA from Arctic lakes traces past climate impacts
Authors: Voosen Paul
Published: December 2019

Ancient vegetation shifts offer clues to the impacts of future warming.
Epilepsy's next frontier
Authors: Couzin-Frankel Jennifer
Published: December 2019

Almost one in every three patients suffers from seizures that are resistant to drugs. Scientists are looking for new ways to help them.
Foiling epilepsy in a brain at risk
Authors: Couzin-Frankel Jennifer
Published: December 2019

With biomarker and animal research, doctors are probing how to prevent epilepsy after a brain injury.
Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants
Authors: Goldbogen J. A. , Cade D. E. , Wisniewska D. M. , Potvin J. , Segre P. S. , Savoca M. S. , Hazen E. L. , Czapanskiy M. F. , Kahane-Rapport S. R. , DeRuiter S. L. , Gero S. , Tønnesen P. , Gough W. T. , Hanson M. B. , Holt M. M. , Jensen F. H. , Simon M. , Stimpert A. K. , Arranz P. , Johnston D. W. , Nowacek D. P. , Parks S. E. , Visser F. , Friedlaender A. S. , Tyack P. L. , Madsen P. T. , Pyenson N. D.
Published: December 2019

It's the prey that matters

Although many people think of dinosaurs as being the largest creatures to have lived on Earth, the true largest known animal is still here today—the blue whale. How whales were able to become so large has long been of interest. Goldbogen
et al.
used field-collected data on feeding and diving events across different types of whales to calculate rates of energy gain (see the Perspective by Williams). They found that increased body size facilitates increased prey capture. Furthermore, body-size increase in the marine environment appears to be limited only by prey availability.

Science
, this issue p.
1367
; see also p.
1316
Realizing the potential of digital development: The case of agricultural advice
Authors: Fabregas Raissa , Kremer Michael , Schilbach Frank
Published: December 2019

Mobile farming advice

Mobile phones are almost universally available, and the costs of information transmission are low. They are used by smallholder farmers in low-income countries, largely successfully, to optimize markets for their produce. Fabregaset al.review the potential for boosting mobile phone use with smartphones to deliver not only market information but also more sophisticated agricultural extension advice. GPS-linked smartphones could provide locally relevant weather and pest information and video-based farming advice. But how to support the financial requirements of such extension services is less obvious, given the unwieldiness of government agencies and the vested interests of commercial suppliers.

Science, this issue p.eaay3038
Cryo–electron microscopy structures of human oligosaccharyltransferase complexes OST-A and OST-B
Authors: Ramírez Ana S. , Kowal Julia , Locher Kaspar P.
Published: December 2019

A division of labor for glycosylation

Glycosylation is a ubiquitous modification of eukaryotic secreted proteins. Asparagine-linked chains of sugars are appended to many substrates as they are translocated into the endoplasmic reticulum. Ramírez
et al.
solved cryo–electron microscopy structures of two human oligosaccharyltransferase complexes, OST-A and OST-B. The catalytic subunits bind partner proteins that direct glycosylation of specific substrates either cotranslationally (OST-A) or on fully folded proteins (OST-B). High-resolution views of the active site and bound substrates in one of the complexes reveal important features of the human enzymes.

Science
, this issue p.
1372
Planning for a warmer world
Building a Resilient Tomorrow
Alice C. Hill and Leonardo Martinez-Diaz
Oxford University Press, 2019. 264 pp.
Authors: Reifsnyder Daniel A.
Published: December 2019

A pair of Obama advisers advocate for proactive climate solutions
Making stronger carbon-fiber precursors
Authors: Fox Bronwyn
Published: December 2019

Cross-linking multiple strands improves strength and toughness of polyacrylonitrile fibers
Two-dimensional polymers grow up
Authors: MacLean Oliver , Rosei Federico
Published: December 2019

Silicon wafer–sized single-layer films are synthesized with a new method
Mastering the element of competition
Periodic: A Game of the Elements
John J. Coveyou and Paul Salomon
Illustrator:
Tomasz Bogusz
Genius Games, 2019.
Authors: Hines Jennifer V.
Published: December 2019

Players race to research the periodic table in an engaging new board game
Accommodation outcomes for children of drug-misusing women
Authors: Mitchell Jennifer , Mactier Helen
Published: December 2019

Children of drug-misusing women are a vulnerable group. Data describing the pattern of accommodation placements are lacking. We investigated 10- to 12-year accommodation outcomes of children born to drug-misusing mothers at a single maternity hospital. 94% of mothers were prescribed maintenance methadone during pregnancy and at least 87% poly-drug used.

Data were successfully matched for 132 children (29% of the original cohort of 450 babies). These children had a total of 291 placements (median 2 (range 1–6)), only 28.5% of which were with the birth parents. At 10–12 years, 54 (41%) were in the care of their parent(s).

83% (109/132) were discharged from the maternity hospital to their birth parents; 41% of these children (54/132) remained with their parents at 10–12 years. Of the 23 children not discharged from the maternity unit to their parents, 70% remain within the care system or have been adopted at 10–12 years of age.
Performance of the MEDS score in predicting mortality among emergency department patients with a suspected infection: a meta-analysis
Authors: Zhang Gensheng , Zhang Kai , Zheng Xie , Cui Wei , Hong Yucai , Zhang Zhongheng
Published: December 2019

Objectives

To carry out a meta-analysis to examine the prognostic performance of the Mortality in Emergency Department Sepsis (MEDS) score in predicting mortality among emergency department patients with a suspected infection.

Methods

Electronic databases—PubMed, Embase, Scopus, EBSCO and the Cochrane Library—were searched for eligible articles from their respective inception through February 2019. Sensitivity, specificity, likelihood ratios and receiver operator characteristic area under the curve were calculated. Subgroup analyses were performed to explore the prognostic performance of MEDS in selected populations.

Results

We identified 24 studies involving 21 246 participants. The pooled sensitivity of MEDS to predict mortality was 79% (95% CI 72% to 84%); specificity was 74% (95% CI 68% to 80%); positive likelihood ratio 3.07 (95% CI 2.47 to 3.82); negative likelihood ratio 0.29 (95% CI 0.22 to 0.37) and area under the curve 0.83 (95% CI 0.80 to 0.86). Significant heterogeneity was seen among included studies. Meta-regression analyses showed that the time at which the MEDS score was measured and the cut-off value used were important sources of heterogeneity.

Conclusion

The MEDS score has moderate accuracy in predicting mortality among emergency department patients with a suspected infection. A study comparison MEDS and qSOFA in the same population is needed.
Continuing conversations about abortion and deprivation
Authors: Christensen Anna
Published: December 2019

In ‘Abortion and deprivation: a reply to Marquis’, I argued that Marquis’ argument about abortion encounters the Epicurean Challenge. In this essay, I continue the conversation begun there. I aim to motivate the Challenge further by examining Marquis’ argument on his own terms and responding to objections about whom death deprives, whether we should focus on the action of killing or the result of death, and how harms suffered before existence compare to harms suffered after death. Finally, I suggest that perhaps the solution to the ethics of killing lies in considering another account of harm entirely—one that does not rely on deprivation.
New Results on Vector and Homing Vector Automata
Authors: Salehi Özlem , Yakaryılmaz Abuzer , Cem Say A. C.
Published: December 2019

We present several new results and connections between various extensions of finite automata through the study of vector automata and homing vector automata. We show that homing vector automata outperform extended finite automata when both are defined over [Formula: see text] integer matrices. We study the string separation problem for vector automata and demonstrate that generalized finite automata with rational entries can separate any pair of strings using only two states. Investigating stateless homing vector automata, we prove that a language is recognized by stateless blind deterministic real-time version of finite automata with multiplication iff it is commutative and its Parikh image is the set of nonnegative integer solutions to a system of linear homogeneous Diophantine equations.
Tree invariants and Milnor linking numbers with indeterminacy
Authors: Komendarczyk R. , Michaelides A.
Published: December 2019

This paper concerns the tree invariants of string links, introduced by Kravchenko and Polyak, which are closely related to the classical Milnor linking numbers also known as [Formula: see text]-invariants. We prove that, analogously as for [Formula: see text]-invariants, certain residue classes of tree invariants yield link-homotopy invariants of closed links. The proof is arrow diagramatic and provides a more geometric insight into the indeterminacy through certain tree stacking operations. Further, we show that the indeterminacy of tree invariants is consistent with the original Milnor’s indeterminacy. For practical purposes, we also provide a recursive procedure for computing arrow polynomials of tree invariants.
EFFECTS OF Co CONCENTRATION ON THE STRUCTURAL AND OPTICAL PROPERTIES OF Zn1−xCoxS FILMS
Authors: LI SHUFENG , WANG LI , SU XUEQIONG , PANG YONG , GAO DONGWEN , HAN XIAOWEI
Published: December 2019

Amorphous and crystalline Zn[Formula: see text]CoxS ([Formula: see text], 0.3, 0.5) thin films were grown on sapphire (Al2O3) substrates by pulsed laser deposition at substrate temperature of 25∘C and 800∘C, respectively. The X-ray diffraction results show that the crystalline film has a cubic zinc blende structure and the crystalline quality decreased with increasing Co-doping concentration. The X-ray diffraction and X-ray photoelectron spectroscopy spectra reveal that the samples reached an overdoping state at Co-doping concentration of [Formula: see text]. The absorbance of films increases and the absorption edge shifts to longer wave length direction with increasing Co-doping concentration. The redshift of the band gap energy depends on the Co composition associating with the Urbach energy. Furthermore, the refractive index and dielectric constant increase with increasing Co-doping concentration. The dispersion parameters, such as dispersion energy ([Formula: see text]), oscillator energy ([Formula: see text]), static refractive index ([Formula: see text]), static dielectric constant ([Formula: see text]), interband transition strength moments ([Formula: see text] and [Formula: see text]), oscillator strength [Formula: see text] and oscillator wavelength [Formula: see text], have been analyzed by Wemple–DiDomenico single oscillator model. All these parameters were found to be dependent upon the Co-doping concentration in the Zn[Formula: see text]CoxS thin films.
GENERATION OF SURFACE COMPOSITES AND CORROSION CHARACTERIZATION OF Mg RZ 5 ALLOY CONTAINING RARE EARTH ELEMENTS
Authors: VEDABOURISWARAN G. , ARAVINDAN S. , SATHYA P.
Published: December 2019

Surface composites are developed on Mg RZ 5 alloy by friction stir processing. During FSP, hard reinforcements are introduced into the matrix of RZ 5 alloy and dispersed uniformly by mechanical stirring action. The reinforcements dispersed were boron carbide, carbon nanotubes (multi-walled) and an 80:20 mixture of zirconia and alumina particles. Dynamic recrystallization and grain boundary pinning action by reinforcement particles resulted in the generation of fine-grained surface composites. Corrosion characteristics of the base material and the surface composites are studied by potentiodynamic polarization technique. The corrosion rates estimated for the surface composites are found to be far lesser than the base material while their polarization resistances were higher than the base material. Among all surface composites, B4C particle reinforced surface composites exhibited the lowest corrosion rate of [Formula: see text]15 mpy. Reduction in the corrosion rate of the surface composites is influenced by fine-grained microstructure and presence of harder reinforcement particles.
GLOBALIZATION AND TERRORISM IN EAST EUROPE AND THE SUCCESSOR STATES OF THE SOVIET UNION
Authors: LUTZ BRENDA J. , LUTZ JAMES M.
Published: December 2019

Globalization has often been suggested as a phenomenon that leads to terrorism due to the disruptions it causes. In the case of the former centrally planned economies of East Europe and Eurasia, however, greater levels of globalization have led to less terrorist incidents and casualties rather than more. Further, the terrorist attacks that did occur did not deter foreign direct investment in the region.
Method summaries for JPF
Authors: Berglund Lasse , Artho Cyrille
Published: December 2019

Java Path nder (JPF) is a virtual machine executing Java byte- code that is able to perform model checking using backtracking execution. Due to backtracking, parts of a program may be ex- ecuted multiple times during model checking. Hence, we explore whether method summaries can be used to make JPF's model checking more efficient. We present the design and implementa- tion of dynamically generated summaries as an extension of JPF.

While our summaries incur an overhead that outweighs the bene- ts in most cases, the approach shows promise in certain cases, in particular when stateless model checking is used. We also provide some results related to cases when our summaries are applicable that could provide guidance for future work within this eld.
Safety Net Policies, Child Poverty, and Development Across the Lifespan
Authors: Dreyer Benard P.
Published: December 2019

The United States has developed an effective safety net of programs starting during the Great Depression, picking up steam in the War on Poverty of the 1960s, and continuing to this day. These efforts have been impactful. Child poverty rates tracked by the supplemental poverty measure have dropped by nearly 50% since the 1960s. Causal studies show that many of these programs improve child outcomes by alleviating income poverty. Some of the evidence shows that such impacts last into adulthood. Nevertheless, addressing child poverty is unfinished business for the United States. Children are still the poorest age group in our society. More robust versions of present safety net programs, as well as the possible introduction of child benefits/child allowances, which many other high-resource countries already provide to families, will need to be considered if we are going to make further progress in substantially reducing child poverty.
Childhood Adversity and Neural Development: A Systematic Review
Authors: McLaughlin Katie A. , Weissman David , Bitrán Debbie
Published: December 2019

An extensive literature on childhood adversity and neurodevelopment has emerged over the past decade. We evaluate two conceptual models of adversity and neurodevelopment—the dimensional model of adversity and stress acceleration model—in a systematic review of 109 studies using MRI-based measures of neural structure and function in children and adolescents. Consistent with the dimensional model, children exposed to threat had reduced amygdala, medial prefrontal cortex (mPFC), and hippocampal volume and heightened amygdala activation to threat in a majority of studies; these patterns were not observed consistently in children exposed to deprivation. In contrast, reduced volume and altered function in frontoparietal regions were observed consistently in children exposed to deprivation but not children exposed to threat. Evidence for accelerated development in amygdala-mPFC circuits was limited but emerged in other metrics of neurodevelopment. Progress in charting neurodevelopmental consequences of adversity requires larger samples, longitudinal designs, and more precise assessments of adversity.
Acupotomy Therapy for Shoulder Adhesive Capsulitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Authors: You Jianyu , Yang Fengyun , Liu Naigang , Tang Nana , Fang Ting , Liu Fushui , Liu Zhongyong , Xie Hongwu
Published: December 2019

Objective. Acupotomy therapy is widely used for pain management. However, the efficacy of acupotomy on shoulder adhesive capsulitis (SAC) is still uncertain. The aim of this study was to determine the effectiveness and safety of acupotomy therapy for SAC. Methods. We searched seven electronic databases to collect randomized controlled trials (RCTs) of acupotomy for SAC published before April 2019. A meta-analysis was performed according to the Cochrane systematic review method by using RevMan 5.3 software. Results. A total of eight RCTs involving 501 patients were enrolled. Meta-analysis showed that acupotomy was significantly better than the control group in debasing the Visual Analogue Scale (VAS) score (MD = −0.97, 95% CI = [−1.49, −0.45], P=0.0003) and improving the Constant–Murley Score (CMS) (MD = 8.46, 95% CI = [1.04, 15.87], P=0.03), and there was no significant difference in adverse events (OR = 1.24, 95% CI = [0.34, 4.52], P=0.74) between the two groups. Conclusion. Acupotomy therapy is an effective and safe treatment for SAC, and this treatment can be recommended for the management of SAC. Due to the low quality and small sample size of the included studies, more rigorously designed RCTs with high quality and large-scale are recommended in future.
miR-657 Promotes Macrophage Polarization toward M1 by Targeting FAM46C in Gestational Diabetes Mellitus
Authors: Wang Pingping , Wang Zengfang , Liu Guojie , Jin Chengwen , Zhang Quan , Man Shuhong , Wang Zengyan
Published: December 2019

MicroRNA (miRNA) has been widely suggested to play a vital role of in the pathogenesis of gestational diabetes mellitus (GDM). We have previously demonstrated that miR-657 can regulate macrophage inflammatory response in GDM. However, the role of miR-657 on M1/M2 macrophage polarization in GDM pathogenesis is not clear yet. This study is aimed at elucidating this issue and identifying novel potential GDM therapeutic targets based on miRNA network. miR-657 is found to be upregulated in placental macrophages demonstrated by real-time PCR, which can enhance macrophage proliferation and migration in vitro. Luciferase reporter assay shows the evidence that FAM46C is a target of miR-657. In addition, miR-657 can promote macrophage polarization toward the M1 phenotype by downregulating FAM46C in macrophages. The present study strongly suggests miR-657 is involved in GDM pathogenesis by regulating macrophage proliferation, migration, and polarization via targeting FAM46C. miR-657/FAM46C may serve as promising targets for GDM diagnosis and treatment.