bluuebunny/crossref_metadata_2025 huggingface dataset:
Endogenous Energy Stores Maintain a High ATP Concentration for Hours in Glucose-Depleted Cultured Primary Rat Astrocytes
Authors: Harders Antonia Regina , Arend Christian , Denieffe Sadhbh Cynth , Berger Julius , Dringen Ralf
Published: March 2023

Adenosine triphosphate (ATP) is the central energy currency of all cells. Cultured primary rat astrocytes contain a specific cellular ATP content of 27.9 ± 4.7 nmol/mg. During incubation in a glucose- and amino acid-free incubation buffer, this high cellular ATP content was maintained for at least 6 h, while within 24 h the levels of ATP declined to around 30% of the initial value without compromising cell viability. In contrast, cells exposed to 1 mM and 5 mM glucose maintained the initial high cellular ATP content for 24 and 72 h, respectively. The loss in cellular ATP content observed during a 24 h glucose-deprivation was fully prevented by the presence of glucose, fructose or mannose as well as by the mitochondrial substrates lactate, pyruvate, β-hydroxybutyrate or acetate. The high initial specific ATP content in glucose-starved astrocytes, was almost completely abolished within 30 min after application of the respiratory chain inhibitor antimycin A or the mitochondrial uncoupler BAM-15, while these inhibitors lowered in glucose-fed cells the ATP content only to 60% (BAM-15) and 40% (antimycin A) within 5 h. Inhibition of the mitochondrial pyruvate carrier by UK5099 alone or of mitochondrial fatty acid uptake by etomoxir alone hardly affected the high ATP content of glucose-deprived astrocytes during an incubation for 8 h, while the co-application of both inhibitors depleted cellular ATP levels almost completely within 5 h. These data underline the importance of mitochondrial metabolism for the ATP regeneration of astrocytes and demonstrate that the mitochondrial oxidation of pyruvate and fatty acids strongly contributes to the maintenance of a high ATP concentration in glucose-deprived astrocytes.
Collective teacher culture and school goal structure: Associations with teacher self-efficacy and engagement
Authors: Skaalvik Einar M. , Skaalvik Sidsel
Published: March 2023

One purpose of this study was to test a model of a collective teacher culture (CTC) proposed by Skaalvik and Skaalvik (Skaalvik and Skaalvik, Social Psychology of Education 24:1389–1406, 2021). In this model, a second-order CTC variable was indicated by four first-order variables: positive and supportive social relations with colleagues, collective teacher efficacy, shared goals and values, and value consonance. A second purpose was to test how a CTC was associated with teachers’ perceptions of the school goal structure (learning and performance goal structures). A third purpose was to explore relations between the two dimensions of the school goal structure, CTC, teacher self-efficacy, and teacher engagement. Participants in the study were 1145 teachers in elementary school, middle school, and high school. The data were analyzed by means of confirmatory factor analyses and SEM analysis. The factor analyses supported the proposed model and revealed that a CTC was positively and strongly associated with a learning goal structure and positively and moderately associated with both teacher self-efficacy and teacher engagement. In contrast, a CTC was negatively associated with a performance goal structure. A learning goal structure was also positively associated with teacher self-efficacy and engagement. In the SEM model, CTC partly mediated the associations between a learning goal structure and teacher self-efficacy and engagement.
Temporary immersion bioreactors as a useful tool for obtaining high productivity of phenolic compounds with strong antioxidant properties from Pontechium maculatum
Authors: Makowski Wojciech , Królicka Aleksandra , Tokarz Barbara , Szopa Agnieszka , Ekiert Halina , Tokarz Krzysztof Michał
Published: March 2023

Pontechium maculatum (Russian bugloss) is a medical plant belonging to the family Boraginaceae. Although this species is known as a medical plant rich in biologically active secondary metabolites, biotechnological studies about this valuable plant is still missing. The scientific objectives of this study were to investigate the biomass production, synthesis, and productivity of various phenolic acids, flavonoids, and shikonin in P. maculatum cultivated in various breeding systems. Additionally, the antioxidant activity of plant-derived extracts was evaluated. Plants were cultivated in a traditional agar-solidified medium, a liquid medium with rotary shaking, and a temporary immersion bioreactors Plantform™ (TIB), as well as cultivated in soil (ex vitro conditions). Analyses of the growth index and dry weight accumulation were performed on the collected material. In the extracts obtained from examined plants, total phenolic content was estimated, and qualitative and quantitative analysis of phenolic derivatives using DAD-HPLC was conducted, simultaneously with an analysis of antioxidant capacity. TIB stimulated the highest synthesis of all examined phenolic acids and shikonin. In TIB-cultivated shoots level of rosmarinic acid obtained a concentration of 3160.76 mg × 100 g− 1 dry weight (DW), and shikonin obtained a concentration of 77.26 mg × 100 g− 1 DW. Furthermore, plants from TIB were characterized by the highest productivity of all studied phenolic derivatives, what makes it very effective platform for the synthesis of biologically active secondary metabolites in Russian bugloss. Moreover, this article shows that P. maculatum is a rich source of various phenolic derivatives with high antioxidant potential.
Recidivism of Individuals Who Completed Schedule I Drugs Deferred Prosecution Treatment: A Population-Based Follow-Up Study from 2008 to 2020 in Taiwan
Authors: Ku Yi-Chien , Chung Hung-Ping , Hsu Chia-Yu , Cheng Yuan-Hao , Hsu Freya In-Chu , Tsai Yi-Chia , Chao En , Lee Tony Szu-Hsien
Published: March 2023

Deferred Prosecution with Condition to Complete the Addiction Treatment (DPCCAT) is a judicial diversion program in Taiwan that shifts people who use drugs away from the label drug offender and toward the label patient. However, little is known about the effectiveness of completing a DPCCAT program on people who use drugs. Using a nationwide population-based retrospective panel data from 2008 to 2020, recidivism is defined as a person was caught urine positive and charged by a prosecutor after their completion of DPCCAT. After controlled gender, age, and region, comparisons of recidivism rates and time to relapse between Schedule I drug use only, Schedule I & II drug use, and heterogeneous group were examined. Of 24,248 participants with DPCCAT, 11,141 (46%) completed the one-year treatment program. Of completers, the five-year recidivism rates are significantly lower for the Schedule I drug use only (26%) than Schedule I & II drugs use (52%) and heterogeneous group (47%). Results from Cox regression indicated that the duration of recidivate to drug use is significantly longer for the Schedule I drug only than the other two groups after controlling for demographics. The main findings support that completion of a DPCCAT program only reduces the risk of recidivism for people who use Schedule I drug only and is less effective for polydrug users and heterogeneous group. We suggest that characteristics of people who use drugs and other criminal offenses should be taken into consideration for triage when DPCCAT is offered.
Position paper on CDK4/6 inhibitors in early breast cancer
Authors: Gnant Michael , Singer Christian F. , Rinnerthaler Gabriel , Pfeiler Georg , Egle Daniel , Balic Marija , Bartsch Rupert
Published: March 2023

Inhibitors of the cyclin-dependent kinases 4/6 (CDK4/6i) have been practice-changing and are now considered the standard of care in combination with endocrine therapy for the first- or second-line treatment in advanced hormone-receptor-positive, human epidermal growth factor receptor 2‑negative breast cancer. Recently, CDK4/6i have also emerged as an appealing targeted cancer therapy in early breast cancer, however results of large clinical trials are controversial. This position paper summarizes the evidence, and provides guidance for clinical practice.
Lower limit of effective reservoir physical properties and controlling factors of medium-deep clastic reservoirs: a case study of the Dawangzhuang area in Raoyang sag, Bohai Bay Basin
Authors: Zhai Chenyu , Lv Chuanbing , Gao Renan , Li Fengqun , Xie Jun , Yu Shanshan , Zhang Zhimin , Mou Yingshun , Wang Hongmei
Published: March 2023

With the continuous improvement of oil and gas exploration in the middle and shallow layers, the deep Paleogene in Raoyang sag has become an important exploration field of “increasing reserves and production” in North China. The recognition and control factors of deep effective reservoirs are unclear, which restricts the recognition effect of oil and gas exploration. The key to identify effective reservoirs is to determine the lower limit standard of reservoir physical properties. The single method for calculating the lower limit of physical properties has limitations. The lower limit of the effective reservoir physical properties of the Shahejie Formation in the Dawangzhuang area was obtained by comprehensively using physical property, well logging and oil test data. The data were analysed by oil testing method, metre oil production index test method and frequency curve intersection method. On this basis, combined with the cast thin-section observations, scanning electron microscopy and other test results, the comprehensive control of effective reservoir development of the Shahejie Formation in the Dawangzhuang area of the Raoyang sag was studied from various factors, such as formation pressure, sand body thickness and diagenesis. The results show that the lower limit of porosity was 9.73, 9.44 and 8.85% at depths of Es1, Es2 and Es3, respectively. The lower limit of permeability was 1.21 × 10–3, 1.18 × 10–3 and 0.59 × 10–3 μm2, respectively. Effective reservoirs are easier to form in areas with formation pressure coefficient greater than 1.2. Formation overpressure inhibits compaction and promotes dissolution. The proportion of effective reservoirs of sand bodies with thicknesses greater than 2 m can reach more than 75%. The influence of diagenesis on the reservoir is mainly manifested in compaction and cementation making the reservoir compact. The porosity reduction rate caused by compaction can reach 20–75%, while dissolution makes the reservoir form secondary pores. The average pore throat radius of secondary pores can reach 4 ~ 6.3 µm. This study makes use of the applicability of different methods, which is more instructive for predicting the effective reservoir of the Shahejie Formation in the study area. In addition, the research results provide a reference for the development mechanism of medium-deep clastic reservoirs.
Prediction of wing buffet pressure loads using a convolutional and recurrent neural network framework
Authors: Zahn R. , Weiner A. , Breitsamter C.
Published: March 2023

In the present study, a hybrid deep learning reduced-order model (ROM) is applied for the prediction of wing buffet pressure distributions on a civil aircraft configuration. The hybrid model is compound of a convolutional variational neural network autoencoder (CNN-VAR-AE) and a long short-term memory (LSTM) neural network. The CNN-VAR-AE is used for the reduction of the high-dimensional flow field data, whereas the LSTM is applied to predict the temporal evolution of the pressure distributions. For training the neural network, experimental buffet data obtained by unsteady pressure sensitive paint measurement (iPSP), is applied. As a test case, the Airbus XRF-1 configuration is selected, considering two different experimental setups. The first setup is defined by a wind tunnel model with a clean wing, whereas the second setup includes an ultra high bypass ratio engine nacelle on each wing. Both configurations have been tested in the European Transonic Windtunnel, considering several transonic buffet conditions. Finalizing the training of the hybrid neural networks, the trained models are applied for the prediction of buffet flow conditions which are not included in the training data set. A comparison of the experimental results and the pressure distributions predicted by the hybrid ROMs indicate a precise prediction performance. Considering both aircraft configurations, the main buffet flow features are captured by the hybrid ROMs.
Laser texturing of piston ring for tribological performance improvement
Authors: Ferreira Rita , Carvalho Óscar , Sobral Luís , Carvalho Sandra , Silva Filipe
Published: March 2023

The radial surface coating layer of compression piston rings is used to improve their wear resistance during the internal combustion engine operation. However, at top dead centers, the friction coefficient of the piston ring-cylinder liner pair is detrimental to the engine’s tribological performance. In this work, dimples with different texture dimensions and densities were tested in a home-developed tribometer. The friction coefficient was measured for all samples, and for those with the best results, their wear resistance was assessed. The texture with an aspect ratio of 0.25 and a density area of 15% reported the best tribological results.
Comparison of Pretreatment Methods for Organic-matter Removal and their Effects on the Hydrogen Isotope (δ2H) Composition of Kaolinite
Authors: Samanta Arpita , Bera M. K. , Sreenivasan Sruthi P. , Sarkar Anindya
Published: March 2023

The hydrogen isotopic composition (δ2H) of authigenic clay minerals has been used extensively in paleoclimate studies. The separation of clay minerals from sediments/soils, using various chemicals, is a prerequisite for isotope ratio measurements, where carbonate, Fe-(oxyhydr)oxides, and organic matter are removed successively from the sediments for a greater clay yield. The commonly adopted organic matter-removal method using hydrogen peroxide (H2O2) is thought to either alter directly the pristine δ2H values of the smectite clay minerals or to introduce organic hydrogen-bearing impurities through the ineffective removal of organic matter. The objective of the present study was to test whether H2O2 treatment can alter the δ2H values of kaolinite (Kln) by comparing two organic matter-removal methods, namely, H2O2 and disodium peroxodisulfate (Na2S2O8) combined with a neutral buffer. In doing so, kaolinite-rich, old (~56 Ma) sediment samples and pure kaolinite internal laboratory reference materials were used to understand the effectiveness and suitability of the above-mentioned methods in clay-sample preparation for δ2H measurements. The δ2H values of the H2O2-treated aliquots show smaller δ2H values than those for the Na2S2O8-treated aliquots. Estimated ambient water δ18O values (−4‰) from the Na2S2O8-treated aliquots agreed well with the bio-phosphate (fish vertebrae) based environmental water δ18O estimation (−3.3‰). The present study indicated, therefore, that δ2H values obtained after Na2S2O8 treatment are likely to be more realistic for paleoclimate reconstruction.
A forecasting method of multi-category product sales: analysis and application
Authors: Wang Jing , Luo Ling
Published: March 2023

To solve the problems of high prediction costs and difficult practices in multi-category product classification in the retail industry, optimize the inventory, and improve resilience, this work introduces a forecasting method for multi-category product sales. The forecasting method divides the data into a category set and a numerical set, uses the stacking strategy, and combines it with catboost, decision tree, and extreme gradient boosting. During the feature engineering process, the ratio and classification features are added to the category feature set; the sales attare used for training to obtain the prediction at (t + 1); and the features used in the prediction at time (t + 1) are generated by the prediction results att. The update processes of the two sets are combined to form a joint feature update mechanism, and multiple features ofkcategories are jointly updated. Using this method, data of all categories of retail stores can be linked so that historical data of different categories of goods can provide support for the prediction of each category of goods and solve the problem of insufficient product data and features. The method is verified on the retail sales data obtained from the Kaggle platform, and the mean absolute error and weighted mean absolute percentage error are adopted to analyze the performance of the model. The results reveal that the forecasting method can provide a useful reference to decision-makers.
Design and Implementation of Clinical LIS360 Laboratory Management System Based on AI Technology
Authors: Fu Qiang , Lai Jianfeng , Zhong Tingting , Ran Li
Published: March 2023

In order to realize the automation, standardization, and informatization of clinical laboratory work, this research topic develops and accomplishes a set of laboratory information systems (LISs). According to the design methods of software engineering, we first understand user’s demand and the current work situation of clinical laboratory and establish the system case model using Unified Modeling Language (UML) modeling technique. During the system design period, we explain the key technology theories, network structure, system security policy and the connection scheme with hospital information system (HIS). During the system function design period, the system was designed with 6 modules, they are daily inspection work, inquire and statistics, quality control, data dictionary, system configuration, and other tools. Through establishing database model, we accomplish the system database structure design. After the system design, we perform system implementation and test, to show the interface of system implementation and test plan accordingly. The development and application of LIS360 laboratory information management system can greatly improve the management level of laboratory and promote the standardization, modernization, and science of laboratory management. This system has solved the traditional mode of sending test report sheet manually for many years in the laboratory and won valuable time for clinicians to know the patient's condition in time.
A robust transfer deep stochastic configuration network for industrial data modeling
Authors: Guo Jingcheng , Yan Aijun , Tang Jian
Published: March 2023

A robust transfer deep stochastic configuration network for industrial data modeling is proposed to address challenging problems such as the presence of outliers (or noise) and conditional drift of the data model due to changes in working conditions. Assuming that outliers follow the t-distribution, the maximum a posteriori estimation is employed to evaluate the read-out weights, and the expectation maximization algorithm is used to iteratively optimize the hyperparameters of the distribution. Moreover, the knowledge contained in the data are expressed in the form of the model structure, connection weights and outlier distribution, and a knowledge-data-based robust transfer strategy is developed to offset the impact of insufficient training data on the learning performance of a deep stochastic configuration network with a new working condition. Comparative experiments are carried out using the historical furnace temperature data of a municipal solid waste incineration plant in China. The results show that the proposed method performs more favorably in robust data modeling and mitigates the impact of changes in working conditions on the applicability and accuracy.
On the robustness of vision transformers for in-flight monocular depth estimation
Authors: Ercolino Simone , Devoto Alessio , Monorchio Luca , Santini Matteo , Mazzaro Silvio , Scardapane Simone
Published: March 2023

Monocular depth estimation (MDE) has shown impressive performance recently, even in zero-shot or few-shot scenarios. In this paper, we consider the use of MDE on board low-altitude drone flights, which is required in a number of safety-critical and monitoring operations. In particular, we evaluate a state-of-the-art vision transformer (ViT) variant, pre-trained on a massive MDE dataset. We test it both in a zero-shot scenario and after fine-tuning on a dataset of flight records, and compare its performance to that of a classical fully convolutional network. In addition, we evaluate for the first time whether these models are susceptible to adversarial attacks, by optimizing a small adversarial patch that generalizes across scenarios. We investigate several variants of losses for this task, including weighted error losses in which we can customize the design of the patch to selectively decrease the performance of the model on a desired depth range. Overall, our results highlight that (a) ViTs can outperform convolutive models in this context after a proper fine-tuning, and (b) they appear to be more robust to adversarial attacks designed in the form of patches, which is a crucial property for this family of tasks.
Selenium intakes in the Irish adult population
Authors: Buffini Maria , Nugent Anne P. , Walton Janette , Flynn Albert , McNulty Breige A.
Published: March 2023

Selenium (Se) is an essential trace element which has an important role as a constituent of seleno-proteins involved in various physiological processes. Previous research in Irish adults suggests that intakes of this important nutrient are suboptimal. The aim of the present study was to estimate the current intakes and major food sources of Se by Irish adults. Mean daily intakes (MDIs) of Se were calculated using data from the National Adult Nutrition Survey which involved 1500 Irish adults aged 18–90 years. The Se content of foods and drinks consumed over a 4-d period was determined using data from the Irish Total Diet Study (TDS). Adequacy of Se intakes was assessed by calculating the proportion of the population with intakes below the adequate intake (AI) of 70 μg/d and lower reference nutrient intake of 40 μg/d (LRNI). The MDI of Se in the total population was 71⋅7 μg/d, with significantly higher intakes reported in men (80⋅2 μg/d) compared with women (63⋅4 μg/d, P < 0⋅01). Meat and meat products were the major contributing food group to Se intakes for both men (37 %) and women (31 %). Overall, 47 % of the population were not meeting the recommended AI, while 4 % of the total population were not meeting the LRNI. Although the average intake of Se is above the AI, a significant proportion of the population is not meeting this recommendation and continued monitoring of Se intakes is necessary, particularly by at-risk groups and also in the context of sustainability.
Long time series (1984–2020) of albedo variations on the Greenland ice sheet from harmonized Landsat and Sentinel 2 imagery
Authors: Feng Shunan , Cook Joseph Mitchell , Anesio Alexandre Magno , Benning Liane G. , Tranter Martyn
Published: March 2023

Albedo is a key factor in modulating the absorption of solar radiation on ice surfaces. Satellite measurements have shown a general reduction in albedo across the Greenland ice sheet over the past few decades, particularly along the western margin of the ice sheet, a region known as the Dark Zone (albedo < 0.45). Here we chose a combination of Landsat 4–8 and Sentinel 2 imagery to enable us to derive the longest record of albedo variations in the Dark Zone, running from 1984 to 2020. We developed a simple, pragmatic and efficient sensor transformation to provide a long time series of consistent, harmonized satellite imagery. Narrow to broadband conversion algorithms were developed from regression models of harmonized satellite data and in situ albedo from the Program for Monitoring of the Greenland Ice Sheet (PROMICE) automatic weather stations. The albedo derived from the harmonized Landsat and Sentinel 2 data shows that the maximum extent of the Dark Zone expanded rapidly between 2005 and 2007, increasing to ~280% of the average annual maximum extent of 2900 km2 to ~8000 km2 since. The Dark Zone is continuing to darken slowly, with the average annual minimum albedo decreasing at a rate of $\sim \!-0.0006 \pm 0.0004 \, {\rm a}^{-1}$ (p = 0.16, 2001–2020).
Buckling of circular cylinders due to transverse shear, axial compression and normal pressure
Authors: Meyer R. R.
Published: March 2023

Buckling equations for stiffened cylinders under the specified loading are formulated and solved by means of double Fourier series using the Galerkin process to reduce the solution to the standard algebraic eigen-value problem. Matrices of order 80 by 80 are required for convergence reflecting the complexity of the mode shape describing the buckling patterns.

Simple design curves are developed for determining buckling loads of monocoque cantilever loaded cylinders.

Excellent agreement with test values is demonstrated, indicating that the cylinders are not highly sensitive to imperfections, as is the case of the uniform, axially loaded cylinder. This also follows from the fact that considerable post buckling strength exists for the cantilever loading condition.
The prediction of separated flow using a viscous-inviscid interaction method
Authors: Williams B.R.
Published: March 2023

The separation of boundary-layer flow from a wing or in a diffuser usually defines the limit of efficient operation, so it is important that the onset and development of separated flow can be predicted. The calculation of the interaction of the shear layout close to an aerofoil with the external inviscid flow has offered an attractive alternative to solving the Reynoldsaveraged Navier Stokes equations for attached flow: the interaction method is much faster. In this paper it is shown how the interaction approach can be extended for use with separated flows and the development of a practical method is described. The calculation of the shear layer through the singularity at separation is accomplished by using an inverse mode. Beyond separation the empirical definition of a new family of velocity profiles allows an integral calculation of the shear layer to proceed up to the reattachment. The solutions for the shear layer close to the aerofoil are matched to the external inviscid flow by a ‘semi-inverse’ method. A careful examination of the stability of this method leads to rapid convergence for separated and attached flows. As an illustration the stall and post stall behaviour of a twodimensional aerofoil is predicted and compared with experimental results.
On the teaching of the principles of wing flexure-torsion flutter
Authors: Hancock G. J. , Wright J. R. , Simpson A.
Published: March 2023

This note attempts to clarify some basic ideas, and correct some common misunderstandings, on wing flexure-torsion flutter. Topics include:

(i) an understanding of the physics of wing flexure-torsion flutter through a number of specific examples,

(ii) an examination of the energy interpretation of the physics of flutter, indicating its limited usefulness,

(iii) a discussion of the significant differences between wing flexure-torsion flutter and the Duncan flutter engine,

(iv) a graphical representation to assess the contribution of various parameter to flutter onset,

(v) subcritical response below the critical flutter speed,

(vi) some practical wing flutter considerations.
An exact integral (field panel) method for the calculation of two-dimensional transonic potential flow around complex configurations
Authors: Sinclair P. M.
Published: March 2023

An exact integral formulation of the two-dimensional full potential equation is presented. The well developed standard surface panel method based on the linear Prandtl-Glauert equation is extended by means of sources in the field surrounding the configuration, allowing the calculation of transonic flows.

A major attraction of the Field Panel Method is that solutions can be obtained using standard surface panelling together with a field grid which has no special form. The surface panels are used to satisfy the boundary conditions so that the field grid does not have to be surface-fitted which is a requirement for existing field methods. Further, the grid need only be in a region close to the configuration where nonlinear compressibility effects are non-negligible and need not extend to the far field as generally required. Grid generation is therefore trivial allowing solutions for arbitrary configurations. Convergence, especially for flows with shock waves, is enhanced by use of a modified Approximate Factorisation scheme. Results for single aerofoils are compared with Garabedian-Korn solutions and show good agreement; and to demonstrate the ease of grid generation, results for multicomponent aerofoils are also presented. Finally, an outline is given of how the method can be extended to threedimensions.

The work was carried out in conjunction with the Department of Applied Mathematics, University of Leeds together with Procurement Executive, Ministry of Defence.
The fundamentals of body-freedom flutter
Authors: Niblett LL. T
Published: March 2023

The object of this paper is to uncover the nature of the destabilising coupling that is the major cause of body-freedom flutter and to see whether a simple cure for the flutter can be found. To do this frequency-coalesence theory is applied to a simple aircraft. It is shown that the aircraft is liable to flutter if it has a sweptforward wing and a positive ‘tail-off’ cg margin or a sweptback wing and a negative cg margin but a simple cure for the flutter does not appear to exist.
Upstream influence on turbulent jet flows from cruciform nozzles
Authors: Quinn W. R , Marsters G. F
Published: March 2023

The mixing of single or multiple jets is relevant in several engineering applications ranging from flame stabilisation in combustion to high lift devices for V/STOL aircraft. In some of these applications, expeditious manufacturing and ease of installation may dictate the use of sharp-edged slots in preference to nozzles with contoured upstream shaping.

It has been suggested that cruciform nozzle exit shapes may be suitable for improving mixing and thus thrust augmentation in STOL aircraft. The effects of nozzle geometry on the performance of an axisymmetric thrust augmentor have been investigated experimentally and a very slight improvement in the performance of the axisymmetric thrust augmentor was observed when cruciform nozzles were used after the tests had been performed with circular nozzles.
Spurious entropy production and very accurate solutions to the Euler equations
Authors: Rizzi Arthur
Published: March 2023

Since it is not assumed a priorito be constant, entropy can vary along streamlines in the numerical solution of the Euler equations, depending upon its accuracy, even if the flow is isentropic. The level of this spurious entropy (or equivalently loss in total pressure) produced in the solution has become a common measure for the accuracy of the solution. It was used in a recent exercise by the AGARD Working Group 07 as one of the primary criteria to judge the most accurate solutions of the Euler equations for a variety of different test problems. Of the four possible sources of this error: mesh spacing, convective difference scheme, artificial viscosity model, and boundary conditions, the latter two are found to contribute the most. The steps taken to limit the errors coming from each of these four areas are described in detail in the context of two AGARD test cases: NACA 0012 M∞, = 0·85 α= 1 deg, and NLR 7301 M∞ = 0·721 α=-0·194 deg. An accurate shock-free supercritical solution is presented for the latter case.
The interaction of a wake with a turbulent boundary layer
Authors: Zhou Ming De , Squire L.C.
Published: March 2023

In the flow over high-lift aerofoils there is a strong interaction between the wake from one element and the boundary layer on another element immediately downstream. A number of experimental investigation of these types of flow have been made but these studies do not allow the effects associated with the various parameters of the aerofoil to be seen easily. This paper presents the results of extensive measurements of mean and fluctuating quantities made in merging layers in zero and adverse pressure gradients downstream of aerofoils of various shapes. A general description of the emerging process is given and the effects of wake characteristics and pressure gradient are considered. The paper also contains a discussion of the modelling of the Reynolds shear stress in the merging layer.
On aircraft flight performance in a perturbed atmosphere
Authors: Campos L. M. B. C.
Published: March 2023

We consider the effect of atmospheric disturbances, such as wind, shears, turbulence, wakes and downflows, on aircraft performance (section 1), recalling the minimum of aerodynamics (section 2) necessary for the calculation of the effects on flight mechanics. For example, it is shown (section 3) that the relative lift change, due to wind, shear or both, coincides with the disturbance intensity G, defined as the instantaneous vertical acceleration, measured in g's, that an aircraft will experience as a consequence of atmospheric disturbances, assuming constant velocity and attitude. The disturbance intensity is a measure of the total force that the atmospheric disturbance can exert on the aircraft; this force may cause changes in normal acceleration, flight velocity and angle-of-attack, either isolated (section 5) or combined (section 6), in straight and level flight; in the case of a horizontal turn (section 7), the disturbance intensity specifies the changes in instantaneous turn rate, velocity, radius (section 8), acceleration and bank angle (section 9) due to atmospheric perturbations, and their cumulative effect over time in (section 10) deforming and displacing trajectories. These effects (section 11) are quantified by formulas and illustrated in graphics, and we indicate throughout the flight mechanical consequences of disturbances with the critical intensities G1 = — 0·17 and G2 = — 0·42; these are the disturbance intensities which, if uncompensated, would be just enough to cause an aircraft to stall (section 4) respectively at unstick on take-off and on approach to land. We conclude (section 12) with a discussion of the use of the disturbance intensity as a parameter in the reduction and analysis of flight data.
New rotary rig at RAE and experiments on HIRM
Authors: O’Leary C. O. , Rowthorn E. N.
Published: March 2023

A rig for measurement of forces and moments due to continuous rate of roll has been commissioned at RAE Bedford. Tests have been made on a High Incidence Research Model (HIRM) in two wind tunnels at M = 0·2, 0·4 and 0·7. At present models can be tested up to 40° angle of attack at rotational speeds up to 350 rpm.

Tests on HIRM included an investigation of configuration and Reynolds number effects. Results are compared with similar data from tests with another rolling rig and from small amplitude oscillatory tests.
Performance of the Wells self-rectifying air turbine
Authors: Raghunathan S. , Tan C. P. , Ombaka O. O.
Published: March 2023

Analytical and experimental studies of the effect of geometric and aerodynamic variables on the performance of the Wells self-rectifying air turbine are presented in this paper. Two approaches to the prediction of the Wells turbine performance are described, both of which are based on the two dimensional cascade theory and isolated aerofoil data. Experimental results are based on the investigations in Unidirectional and oscillating airflow rigs.

Comparisons are made on the analytical and experimental results.
Test cases for the plane potential flow past multi-element aerofoils
Authors: Suddhoo A. , Hall I. M.
Published: March 2023

The method of images is used to calculate the analytical solution for an inviscid incompressible flow past four arbitrary circles which are then conformally mapped onto aerofoil sections. The analytical solution of the corresponding flow past the system of aerofoils is obtained and the pressure distributions about a particular three-element and a particular fourelement aerofoil are presented. These results are intended to be used to assess the accuracy of numerical methods.
Impact of salinity on yield-related parameters in two contrasting cultivars ofOryza glaberrimaSteud. in Benin
Authors: Prodjinoto Hermann , Gandonou Christophe , Irakoze Willy , Lutts Stanley
Published: March 2023

Salinity is one of the major environmental stresses limiting growth and yield of rice. The objective of the present study was to analyze the impact of NaCl on yield-related parameters ofOryza glaberrima. Two contrasted cultivars ofOryza glaberrimapreviously tested for salt resistance at the vegetative stage [salt-resistant (TOG5307) and salt-sensitive (TOG5949)] were irrigated with a saline solution containing 30 mM NaCl (EC: 3 dS.m−1NaCl). After 6 months of treatments, mineral nutrient and yield-related parameters were assessed. Proline was quantified in the panicle leaf at the start of the grain filling stage. NaCl treatment affected most yield-related parameters: panicle length, panicle leaf dry weight, number of branches per panicle, panicle leaf length, days to 50% heading, straw fresh weight per plant, grain yield per plant, number of spikelets per panicle, and number of filled grains per panicle. The weight of 1,000 grains decreased in the salt-sensitive cultivar only, suggesting that grain filling processes were compromised. The salt-resistant cultivar TOG5307 was less affected than the salt-sensitive TOG5949 and accumulated lower amounts of Na+in the grains. For both cultivars, hulls contained higher concentration of Na+and K+than grains. TOG5307 also contained more proline in the panicle leaf than TOG5949, suggesting that TOG5307 can cope with the osmotic component of salt stress. The cultivar exhibiting the highest salt resistance at the vegetative stage also exhibited the highest resistance at the reproductive one.
Reimagining conservation practice: Indigenous self-determination and collaboration in Papua New Guinea
Authors: Aini John , West Paige , Amepou Yolarnie , Piskaut Michael Ladi , Gasot Cornelius , James Rachel S. , Roberts Jason Steadman , Nason Patrick , Brachey Anna Elyse
Published: March 2023

Here we describe a 14-year collaboration in New Ireland, Papua New Guinea, between an Indigenous NGO, Indigenous scientists and international researchers. New Ireland is a marine province in the Western Pacific region where most residents depend on fishing, marine gleaning and small-scale gardening for their livelihoods. Ailan Awareness is a locally founded and managed NGO that focuses on the strengthening of Indigenous sovereignty regarding biological, cultural and spiritual diversity as well as fostering Indigenous epistemology practices and strengthening biocultural diversity. In partnership with anthropological researchers, Ailan Awareness has designed an approach to marine conservation informed by the growing field of decolonial research practices. By working to empower coastal communities to make decisions about their marine and cultural resources using a mix of Indigenous, anthropological and scientific methods and giving primacy to strengthening Indigenous modes of knowledge production and the role of community Elders, Ailan Awareness addresses a major gap in the efforts of the national government and international NGOs: giving the people most directly affected by declining biodiversity and loss of tradition the support and tools required to design and carry out the strengthening of both biological diversity and traditional social practices. In this paper we describe the methodology used by Ailan Awareness and the history of collaboration that resulted in these methods.
Geographical variation in hepatitis C-related severe liver disease and patient risk factors: a multicentre cross-sectional study
Authors: Nickbakhsh Sema , McWilliam Leitch E. Carol , Smith Shanley , Davis Chris , Hutchinson Sharon , Irving William L. , McLauchlan John , Thomson Emma C.
Published: March 2023

Despite promising steps towards the elimination of hepatitis C virus (HCV) in the UK, several indicators provide a cause for concern for future disease burden. We aimed to improve understanding of geographical variation in HCV-related severe liver disease and historic risk factor prevalence among clinic attendees in England and Scotland. We used metadata from 3829 HCV-positive patients consecutively enrolled into HCV Research UK from 48 hospital centres in England and Scotland during 2012–2014. Employing mixed-effects statistical modelling, several independent risk factors were identified: age 46–59 y (ORadj 3.06) and ≥60 y (ORadj 5.64) relative to <46 y, male relative to female sex (ORadj 1.58), high BMI (ORadj 1.73) and obesity (ORadj 2.81) relative to normal BMI, diabetes relative to no diabetes (ORadj 2.75), infection with HCV genotype (GT)-3 relative to GT-1 (ORadj 1.75), route of infection through blood products relative to injecting drug use (ORadj 1.40), and lower odds were associated with black ethnicity (ORadj 0.31) relative to white ethnicity. A small proportion of unexplained variation was attributed to differences between hospital centres and local health authorities. Our study provides a baseline measure of historic risk factor prevalence and potential geographical variation in healthcare provision, to support ongoing monitoring of HCV-related disease burden and the design of risk prevention measures.
“An Isolating Experience Aggravated by COVID”: Exploring Disconnections Between Political Science PhD Candidates and Supervisors
Authors: Rutledge-Prior Serrin , Casey Daniel
Published: March 2023

To what extent did the COVID-19 pandemic impact PhD candidates in political science? To what extent were their supervisors aware of this impact? PhD candidates in political science are not strangers to the lack of available and stable academic employment and the potentially isolating experience of research. Our survey of Australian PhD candidates in political science and international relations (N = 109) confirms that the COVID-19 pandemic exacerbated these preexisting challenges. By comparing political science PhD candidates and their supervisors in relation to their experiences during the pandemic, our survey also reveals that there has been a disconnect between the two groups relative to the former’s experience of COVID-19. Although supervisors recognize the stressors that candidates have faced, they are more likely than candidates to report that department support relative to pandemic-related challenges was available, and they appear to be somewhat unaware of the impact that COVID-19 has had on candidates’ career plans. The survey also reveals substantial disagreement between candidates and supervisors about perceived career-mentoring styles. These points of disconnect must be addressed to ensure the success and well-being of current and future PhD candidates.
To protest or not to protest? Migrant workers’ participation in protests in China
Authors: Chen Yen-Hsin , Mason T. David
Published: March 2023

We present a theoretical explanation for why migrant workers in China should be less likely to participate in protests than other categories of workers. While grievance-based theories of protest would suggest that migrant workers have more incentive to protest than other categories of workers, resource mobilization theory suggests that their capacity to mobilize for collective action is impeded by the conditions of their work situation and their residence. Using survey data from CGSS 2010, we test propositions derived from this framework. We find that a greater sense of relative deprivation is associated with a greater likelihood of participating in protest across all categories of workers. However, we also find that migrant worker status functions as a moderator between grievances and protest participation: compared to urban registered workers, migrant workers are significantly less likely to take part in protest activities when both of them have high levels of perceived unfairness. These findings are robust across all models.
Planetary geodynamics and age constraints on circumstellar habitable zones around main sequence stars
Authors: Mello Fernando de Sousa , Friaça Amâncio César Santos
Published: March 2023

Planetary geodynamics may have an important influence over planetary habitability and the boundaries of the circumstellar habitable zone (CHZ) in space and time. To investigate this we use a minimal parameterized model of the co-evolution of the geosphere and atmosphere of Earth-like planets around F, G, K and M main sequence stars. We found the CHZ for the present Solar System located between 0.92 and 1.09 au for a 1.0 M$_{\oplus }$Earth-like planet, extendible to 1.36 au for a 4.0 M$_{\oplus }$planet. In the literature, the CHZ varies considerably in width and border location, but the outer edges tend to be more spread out than the inner edges, showing a higher difficulty in determining the outer edge. Planetary mass has a considerable effect on planetary geodynamics, with low-mass planets cooling down faster and being less capable of maintaining a rich carbon dioxide atmosphere for several billions of years. Age plays a particularly important role in the width of the CHZ as the CHZ contracts in both directions: from the inner edge (as stellar luminosity increases with time), and from the outer edge (as planetary heat flux and seafloor spreading rate decrease with time). This strongly affects long-lived habitability as the 5 Gyr continuous CHZ may be very narrow or even non-existent for low-mass planets (<0.5 M$_{\oplus }$) and fast-evolving high-mass stars (>1.1 M$_{\odot }$). Because of this, the mean age of habitable terrestrial planets in our Galaxy today may be younger than Earth's age. Our results suggest that the best targets for future surveys of biosphere signatures may be planets between 0.5 and 4.0 M$_{\oplus }$, in systems younger than the Solar System. These planets may present the widest and long-lived CHZ.
A Twenty Years’ Crisis? Rethinking the Cases for U.S. Economic Engagement with China
Authors: Kim Dong Jung
Published: March 2023

Structural realists accuse U.S. economic engagement with China as a mistake driven by liberal idealism and lack of realism. I suggest that this increasingly popular narrative reflecting the traditional idealism-realism distinction is misplaced. First, liberal approaches to international relations can clash with each other when a democratic state engages with an authoritarian state, and engagement is justified by one strand of liberalism—economic interdependence liberalism—whereas a different liberal perspective—democratic peace liberalism—opposes economic engagement with an oppressive regime. Second, realism—in particular, structural realism—posits that important state behaviors reflect the need to attain more relative power than others. Then, if economic engagement better serves a state’s relative capacity vis-à-vis other states, economic exchanges with a potential strategic contender would be an unavoidable choice. The liberal case for economic engagement is much more restrictive than it is often articulated, while a structural realist case for engagement can be convincingly made. For about two decades since the mid-1990s, U.S. administrations defended economic engagement with China not only with economic interdependence liberalism but also by utilizing an argument in line with the structural realist case for engagement. Blaming one foreign policy idea as responsible for today’s strategic difficulties is misleading.