bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of the COVID-19 pandemic on patient complaints within one Irish teaching hospital
Authors: O’Dowd Emily , Lydon Sinéad , Ward Marie E. , Kane Maria , Geary Una , Rudland Chris , O’Connor Paul
Published: February 2023

Background

The
coronavirus disease 2019 (COVID-19) pandemic dramatically impacted the delivery of hospital care in terms of quality and safety.

Objectives

To examine complaints from two time points, quarter 4 (Q4) 2019 (pre-pandemic) and Q4 2020 (second wave), and explore whether there was a difference in the frequency and/or content of complaints.

Methods

A retrospective analysis of complaints from one Irish hospital was conducted using the Healthcare Complaints Analysis Tool (HCAT). Within each complaint, the content, severity, harm reported by the patient, and stage of care were categorised. The complaints were analysed using descriptive statistics and chi-square tests of independence.

Results

There were 146 complaints received in Q4 2019 and 114 in Q4 2020. Complaint severity was significantly higher in Q4 2019 as compared to Q4 2020. However, there were no other significant differences. Institutional processes (e.g. staffing, resources) were the most common reason for complaints (30% in Q4 2019 and 36% in Q4 2020). The majority of complaints were concerned with care on the ward (23% in Q4 2019 and 31% in Q4 2020).

Conclusions

The severity of complaints was significantly higher in Q4 2019 than in Q4 2020, which requires further exploration as the reasons for this are unclear. The lack of a difference in the frequency and content of complaints during the two time periods was unexpected. However, this may be linked to a number of factors, including public support for the healthcare system, existing system-level issues in the hospital, or indeed increased staff collaboration in the context of the COVID-19 crisis.
A simple method to rapidly assess the tibial tuberosity—trochlear groove distance using computed tomography
Authors: Kneafsey Simone L. , Russell Shane P. , Power Fiachra R. , Heffernan Eric J. , Hurson Conor
Published: February 2023

Background

The tibial tuberosity–trochlear groove (TTTG) distance is used to assess patellofemoral instability (PFI) and the likelihood of the development of patellofemoral disorders. The current gold standard in the assessment of the TTTG is computed tomography (CT) or magnetic resonance imaging (MRI). The current image software used for viewing these CT images does not allow for easy assessment of the TTTG.

Aims

This study presents a simple method to measure the TTTG on any image software, utilizing easily available and affordable stationary.

Methods

Four consecutive patients with no known knee pathologies were selected from recent studies at our institution. Their TTTGs were measured using this study’s method and validated using the standard, freely available image analysis software Fiji. Pre-defined anatomical landmarks were located and marked using adhesive pieces of paper. The TTTG was defined as the distance between parallel lines through the apex of the tibial tuberosity and trough of the trochlear groove, where each of these lines is perpendicular to the Dorsal Condylar Line.

Results

The TTTG measured using this study’s method was found to be in agreement with the measurements made using Fiji software.

Conclusions

This study demonstrates that the TTTG can be simply and quickly assessed using readily available and affordable stationery, without the need for expensive or complex secondary analysis software. This could allow for the assessment of PFI in the outpatient clinic whilst the patient is present, offering valuable assistance to the orthopaedic surgeon in clinical decision making.
Acute Stress, Induced by IFNγ  + Aβ, and Chronic Stress, Induced by Age, Affect Microglia in a Sex-Specific Manner
Authors: Mela Virginia , Gaban Aline Sayd , Shatz Paul Marie , Guillot-Sestier Marie-Victoire , Lynch Marina A.
Published: February 2023

Microglial phenotype changes in the aged brain, and also in neurodegenerative diseases, and it is generally accepted that these changes at least contribute to the inflammation that can have detrimental effects on brain health. Accumulating data have determined that there are multiple microglial activation states with consistent findings indicating that with stressors including age, a switch towards an inflammatory phenotype occurs. Among the changes that accompany this is a change in metabolism, whereby glycolysis is increased in microglia. Here, we asked whether sex impacted on the response of microglia to two stressors, interferon-γ + amyloid-β (IFNγ  + Aβ) and age. The data show that IFNγ  + Aβ triggered cells from female mice to adopt a glycolytic phenotype. Metabolism was also altered with age; microglia from aged male mice responded by increasing oxidative phosphorylation, and microglial motility was preserved, contrasting with microglia from female mice where motility was compromised. We conclude that sex is a significant variable in the responses of microglia to stressors.
Plight or light? Elucidating the main and interacting effects of parenting styles and BIS/BAS profiles on left-behind youth’s self-esteem
Authors: Lan Xiaoyu
Published: February 2023

Today, many labor-aged adults worldwide work and live for a prolonged period outside of their places of origin in locations where the laborers’ school-aged children cannot migrate with their parents, creating a group known as left-behind youth. Empirical studies regarding the impact of parental migration (left-behind versus non-left-behind) on positive youth development, such as self-esteem, remain scarce, and the collective findings are divergent and controversial. Accordingly, the relational and individual correlates of self-esteem among those youth are largely underexplored. Two independent studies were conducted to fill these crucial knowledge gaps. In Study 1 (N = 738; Mage = 15.86; 54.6% girls), I compared the self-esteem of left-behind youth and their non-left-behind peers after adjusting for sociodemographic covariates and social desirability. In Study 2 (N = 1060; Mage = 13.05; 49.5% girls), I aimed to replicate the findings obtained from Study 1 but used a different measurement and another independent sample. Additionally, I extended Study 1 to investigate the main and interactive relationships between parenting styles (parental warmth and control) and the behavioral inhibition/activation system profiles with self-esteem. To clarify the commonality and specificity of these relationships, I also estimated the moderating role of left-behind status herein. Converging findings across both studies challenged the widely vulnerable image of left-behind youth and revealed that this group did not show significant differences in terms of self-esteem, as compared to non-left-behind peers. Interaction analyses also suggested that shy left-behind youth weaken the extent to which their self-esteem is detrimentally affected by low parental warmth/high parental control.
Shannon-Taylor technique for solving one-dimensional inverse heat conduction problem
Authors: Annaby M. H. , Al-Abdi I. A. , Ghaleb A. F. , Abou-Dina M. S.
Published: February 2023

The Shannon-Taylor interpolation technique was introduced by Butzer and Engels in 1983. In this work, the sinc-function is replaced by a Taylor approximation polynomial. In this work, we implement the Shannon-Taylor approximations to solve a one-dimensional heat conduction problem. One of the major advantages of this approach is that the resulting linear system of equations of the approximation procedure has an explicit coefficient matrix. This is not the case of the classical sinc methods due to finite integrals involving $$e^{-x^2}$$

e

-

x
2

. We establish rigorous error estimates involving an additional Taylor’s series tail. Numerical illustrations are depicted.
Evidence for an early green/red photocycle that precedes the diversification of GAF domain photoreceptor cyanobacteriochromes
Authors: Priyadarshini Nibedita , Steube Niklas , Wiens Dennis , Narikawa Rei , Wilde Annegret , Hochberg Georg K. A. , Enomoto Gen
Published: February 2023

Phytochromes are linear tetrapyrrole-binding photoreceptors in eukaryotes and bacteria, primarily responding to red and far-red light signals reversibly. Among the GAF domain-based phytochrome superfamily, cyanobacteria-specific cyanobacteriochromes show various optical properties covering the entire visible region. It is unknown what physiological demands drove the evolution of cyanobacteriochromes in cyanobacteria. Here, we utilize ancestral sequence reconstruction and biochemical verification to show that the resurrected ancestral cyanobacteriochrome proteins reversibly respond to green and red light signals. pH titration analyses indicate that the deprotonation of the bound phycocyanobilin chromophore is crucial to perceive green light. The ancestral cyanobacteriochromes show only modest thermal reversion to the green light-absorbing form, suggesting that they evolved to sense the incident green/red light ratio. Many cyanobacteria can utilize green light for photosynthesis using phycobilisome light-harvesting complexes. The green/red sensing cyanobacteriochromes may have allowed better acclimation to changing light environments by rearranging the absorption capacity of the phycobilisome through chromatic acclimation.

Graphical abstract
In silico anti-quorum sensing activities of phytocompounds of Psidium guajava in Salmonella enterica serovar Typhi
Authors: Olaniyi Temitope Deborah , Adetutu Adewale
Published: February 2023

Biofilm contributes hugely to the persistence of typhoid fever in human population and quorum sensing (QS) is an integral mechanism involved in biofilms. Interruption of the QS network has therefore been put forward as one of the important anti-virulence strategies. Methanol extract of Psidium guajava leaves has been confirmed to possess antibacterial and anti-biofilm activities against Salmonella Typhi. This study therefore aimed at investigating the interactions of phytocompounds previously identified in the extract with selected QS proteins of S. Typhi in silico. Appropriate formats of compounds were retrieved and translated using online web servers. Quantitative estimate of drug-likeness, as well as absorption, distribution, metabolism, excretion and toxicity profiles of the compounds, were assessed on ADMETlab 2.0. Three-dimensional structures of two QS proteins of S. Typhi were obtained from Protein Data Bank while others were modelled on SWISS-MODEL. Selected compounds (ligands) were docked with the four proteins via AutoDock 1.5.6 and analyzed on Discovery studio. Eight, out of the seventy-two, phyto-compounds of methanol extract of P. guajava possess desirable drug-likeness (QED > 0.67). Three of them have toxic characteristics and thus, were removed from further consideration. Molecular docking revealed that, of the 5 ligands docked against the proteins, only Benzeneethanamine, 4-methoxy- and Cyclopentadecanone, 2-hydroxy- had affinities for the proteins of interest. The affinity of Cyclopenftadecanone,2-hydroxy- for each of the proteins is higher than that of Benzeneethanamine,4-methoxy- with hydrogen bonds contributing significantly to the interactions. Benzeneethanamine, 4-methoxy- and Cyclopentadecanone,2-hydroxy- from Psidium guajava leaves possess inhibitory properties against QS proteins of S. Typhi.
RNA Methylome Reveals the m6A-Mediated Regulation of Flavor Metabolites in Tea Leaves under Solar-Withering
Authors: Zhu Chen , Zhang Shuting , Zhou Chengzhe , Tian Caiyun , Shi Biying , Xu Kai , Huang Linjie , Sun Yun , Lin Yuling , Lai Zhongxiong , Guo Yuqiong
Published: February 2023

The epitranscriptomic mark N  6-methyladenosine (m6A), which is the predominant internal modification in RNA, is important for plant responses to diverse stresses. Multiple environmental stresses caused by the tea-withering process can greatly influence the accumulation of specialized metabolites and the formation of tea flavor. However, the effects of the m6A-mediated regulatory mechanism on flavor-related metabolic pathways in tea leaves remain relatively uncharacterized. We performed an integrated RNA methylome and transcriptome analysis to explore the m6A-mediated regulatory mechanism and its effects on flavonoid and terpenoid metabolism in tea (Camellia sinensis) leaves under solar-withering conditions. Dynamic changes in global m6A level in tea leaves were mainly controlled by two m6A erasers (CsALKBH4A and CsALKBH4B) during solar-withering treatments. Differentially methylated peak-associated genes following solar-withering treatments with different shading rates were assigned to terpenoid biosynthesis and spliceosome pathways. Further analyses indicated that CsALKBH4-driven RNA demethylation can directly affect the accumulation of volatile terpenoids by mediating the stability and abundance of terpenoid biosynthesis-related transcripts and also indirectly influence the flavonoid, catechin, and theaflavin contents by triggering alternative splicing-mediated regulation. Our findings revealed a novel layer of epitranscriptomic gene regulation in tea flavor-related metabolic pathways and established a link between the m6A-mediated regulatory mechanism and the formation of tea flavor under solar-withering conditions.
Structure and Function
Authors: Novick Rose
Published: February 2023

The history of biology is mottled with disputes between two distinct approaches to the organic world: structuralism and functionalism. Their persistence across radical theory change makes them difficult to characterize: the characterization must be abstract enough to capture biologists with diverse theoretical commitments, yet not so abstract as to be vacuous. This Element develops a novel account of structuralism and functionalism in terms of explanatory strategies (Section 2). This reveals the possibility of integrating the two strategies; the explanatory successes of evolutionary-developmental biology essentially depend on such integration (Section 3). Neither explanatory strategy is universally subordinate to the other, though subordination with respect to particular explanatory tasks is possible (Section 4). Beyond structuralism and functionalism, philosophical analysis that centers explanatory strategies can illuminate conflicts within evolutionary theory more generally (Section 5).
Old Norse Women's Poetry
Authors: Straubhaar Sandra Ballif
Published: February 2023

Text, with English translation in two formats, of all the Old Norse poetry attributed to women - skáldkonur.
Gower's Vulgar Tongue
Authors: McCabe T. Matthew N.
Published: February 2023

Why did Gower choose to write his most famous poem in English? New insights into his purpose and the context and tradition of the poem are presented here.
Rulers and Ruled in Frontier Catalonia, 880-1010
Authors: Jarrett Jonathan
Published: February 2023

Skillful use of original sources teases out the networks of power and association in what was to become Catalonia.
The Cistercians in the Middle Ages
Authors: Burton Janet , Kerr Julie
Published: February 2023

A full and comprehensive survey of the development of the Cistercian Order which emerged from the tumultuous intellectual and religious fervour of the eleventh and twelfth centuries.
Atheism, Religion and Enlightenment in Pre-Revolutionary Europe
Authors: Curran Mark
Published: February 2023

An investigation into the influence of, and reaction to, the atheistic writings of the baron d'Holbach.
Conversations with GC Harcourt on Social Justice in the Face of Economic and Ecological Uncertainty
Authors: Harcourt Wendy
Published: February 2023

In this article, I share insights from the conversations I have enjoyed with my father GC Harcourt on gender, social justice, and economic policy in the last years of his long and fruitful life. Our conversations reflected our overlapping but at times divergent responses to the disruptions caused by environmental, climate, health, economic, and political crises. The article reflects on our conversations around population, alternatives, the pervasiveness of racism in Australia, and the recurring questions of how to bring about change and how to continue despite political disappointments. The article teases out in a gentle way how my perspective, as a feminist political ecologist, diverged from GC Harcourt’s views, and what our conversations together suggest as important challenges to overcome as we confront the current crises of modern capitalism.
Housing and Inequality in Australia
Authors: Morris Alan
Published: February 2023

In Australia and many other advanced economies, housing is playing a central role in accentuating and perpetuating inequality. This paper, drawing on primary and secondary data, discusses the various ways in which housing tenure in Australia contributes to wealth and income inequality. It argues that a neoliberal housing policy framework and accompanying financialisation of housing have facilitated a dramatic increase in house prices, the neglect of social housing, and a deepening wealth and income divide based on housing tenure. With respect to wealth, the key divide is between outright homeowners versus low-income private renters and low-income households in mortgage stress. The wealth of outright homeowners has grown substantially in recent decades and many have been able to acquire a holiday home and/or investment properties, thereby intensifying the wealth divide. Approximately a third of Australian households are now locked out of home ownership for an extended period or even lifelong. Housing tenure status also has an impact on the disposable income of households. For example, low-income outright homeowners are invariably in a far better position with respect to disposable income than their counterparts who have large mortgages or are private renters.
The COVID-19 pandemic and polarisation of income distribution in South Africa
Authors: Oyenubi Adeola
Published: February 2023

A number of reports have shown that workers with certain characteristics are disproportionately affected by the COVID-19 pandemic. Since these characteristics are associated with vulnerable workers, we hypothesise that the income distribution in the pandemic era will be polarised compared to the pre-pandemic period. This article compares the pre-COVID income distribution (February 2020) with the one that prevailed just after the hard lockdown (April 2020). Consistent with the hypothesis, the result shows evidence of polarisation. Disaggregating the analysis by worker characteristics, we find that the polarisation was stronger in vulnerable groups. Our decomposition result suggests that, apart from job losses, returns to gender and job characteristics explain the location and shape differences in the COVID-19 era income distribution. Although this analysis only looks at the short-term effect of the pandemic on income distribution, the result suggests that the structure of labour markets in developing countries is not conducive to a future of work where disruptions (or pandemics) may become more frequent.
Optimization and control of synchrotron emission in ultraintense laser–solid interactions using machine learning
Authors: Goodman J. , King M. , Dolier E. J. , Wilson R. , Gray R. J. , McKenna P.
Published: February 2023

The optimum parameters for the generation of synchrotron radiation in ultraintense laser pulse interactions with planar foils are investigated with the application of Bayesian optimization, via Gaussian process regression, to 2D particle-in-cell simulations. Individual properties of the synchrotron emission, such as the yield, are maximized, and simultaneous mitigation of bremsstrahlung emission is achieved with multi-variate objective functions. The angle-of-incidence of the laser pulse onto the target is shown to strongly influence the synchrotron yield and angular profile, with oblique incidence producing the optimal results. This is further explored in 3D simulations, in which additional control of the spatial profile of synchrotron emission is demonstrated by varying the polarization of the laser light. The results demonstrate the utility of applying a machine learning-based optimization approach and provide new insights into the physics of radiation generation in laser–foil interactions, which will inform the design of experiments in the quantum electrodynamics (QED)-plasma regime.
The high-Reynolds-number stratified wake of a slender body and its comparison with a bluff-body wake
Authors: Ortiz-Tarin Jose L. , Nidhan Sheel , Sarkar Sutanu
Published: February 2023

The high-Reynolds-number stratified wake of a slender body is studied using a high-resolution hybrid simulation. The wake generator is a 6 : 1 prolate spheroid with a tripped boundary layer, the diameter-based body Reynolds number is

${Re}= U_\infty D/\nu = 10^5$

, and the body Froude numbers are

${Fr}=U_\infty /ND=\{2,10,\infty \}$

. The wake defect velocity decays following three stages with different wake decay rates (Spedding, J. Fluid Mech., vol. 337, 1997, pp. 283–301) as for a bluff body. However, the transition points among stages do not follow the expected

$Nt = Nx/U_\infty$

values. Comparison with the wake of a circular disk in similar conditions (Chongsiripinyo & Sarkar, J. Fluid Mech., vol. 885, 2020) quantifies the influence of the wake generator – bluff versus slender – in stratified flow. The strongly stratified

${Fr}=2$

wake is in a resonant state. The steady lee waves strongly modulate the mean flow, and relative to the disk, the 6 : 1 spheroid (a high-aspect-ratio shape) wake at

${Fr}=2$

shows an earlier transition from the non-equilibrium (NEQ) stage to the quasi-two-dimensional (Q2D) stage. The NEQ–Q2D transition is followed by a sharp increase in the turbulent kinetic energy and horizontal wake meanders. At

${Fr}=10$

, the start of the NEQ stage is delayed for the spheroid. Transfers between kinetic energy and potential energy reservoirs (both mean and turbulence) are analysed, and the flows are compared in phase space (with local Froude and Reynolds numbers as coordinates). Overall, the results of this study point to the difficulty of finding a universal framework for stratified wake evolution, independent of the features of the body, and provide insights into how buoyancy effects depend on the wake generator.
Very long baseline interferometry observations of the high-redshift blazar candidate J0141–5427
Authors: Gabányi K. É. , Belladitta S. , Frey S. , Orosz G. , Gurvits L. I. , Rozgonyi K. , An T. , Cao H. , Paragi Z. , Perger K.
Published: February 2023

Active galactic nuclei (AGN) have been observed as far as redshift$z \sim 7$. They are crucial in investigating the early Universe as well as the growth of supermassive black holes at their centres. Radio-loud AGN with their jets seen at a small viewing angle are called blazars and show relativistic boosting of their emission. Thus, their apparently brighter jets are easier to detect in the high-redshift Universe. DES J014132.4–542749.9 is a radio-luminous but X-ray weak blazar candidate at$z = 5$. We conducted high-resolution radio interferometric observations of this source with the Australian Long Baseline Array at$1.7$and$8.5$GHz. A single, compact radio-emitting feature was detected at both frequencies with a flat radio spectrum. We derived the milliarcsecond-level accurate position of the object. The frequency dependence of its brightness temperature is similar to that of blazar sources observed at lower redshifts. Based on our observations, we can confirm its blazar nature. We compared its radio properties with those of two other similarly X-ray-weak and radio-bright AGN, and found that they show very different relativistic boosting characteristics.
An improved method for parameter selection in finite element model updating
Authors: Ratcliffe M. J. , Lieven N. A. J.
Published: February 2023

Conventional wisdom states that coordinate complete experimental response data are required to effect a successful model update. This paper examines the influence measured rotational degrees of freedom have on the behaviour of the frequency response function (FRF) sensitivity updating procedure. Three finite element (FE) model-based case studies are undertaken which suggest that very little improvement is afforded by the inclusion of measured rotations in the updating process.

Error-location strategies in the past have yielded little qualitative information about the optimum selection of updating parameters in the model updating procedure. Two further cases are investigated; these suggest that no amount of coordinate completeness will rectify the debilitating effects of an inadequate p-value choice. A method of selecting the number and location of updating parameters — based on the FRF sensitivity method — is presented. This method is shown to yield promising results.
Stability analysis for inverse simulation of aircraft
Authors: Yip K. M. , Leng G.
Published: February 2023

The integration inverse method has been extensively investigated in the past decade; however, none of the researches fully addresses the stability analysis of the method that is crucial to successful implementation. This paper presents a stability test to analyse the global stability of the integration inverse method for linear time-invariant systems. A stable solution may be obtained from careful selection of the discretisation interval using the proposed stability test. A discrete model is derived to approximate the Newton's scheme in the inverse method. With this approximate model, the stability of the inverse method can be examined. The stability test is exact for linear systems and can be extended to the inverse method for non-linear aircraft simulations by considering an equivalent linear model for each point of the flight envelopes. Guidelines for selection of appropriate reference points in the inverse simulation are given.
Experimental investigation of a loaded rotor blade's interaction with a single vortex
Authors: Masson C. A. , Green R. B. , Galbraith R. A. McD. , Coton F. N.
Published: February 2023

Presented in this paper are the preliminary results from a blade-vortex interaction (BVI) test series conducted in the University of Glasgow's 1·61m x 2·13m closed-return, low-speed windtunnel, in which a single vortex interaction with a rigid, loaded rotor blade was studied. This work is an extension of that by Horner and Galbraith, which describes the flow phenomena present during single vortex interaction with an unloaded blade. The paper presents blade surface pressure data recorded by 72 pressure transducers located in the outer regions of the blade during these interactions. Integrated Cn and Cm1/4 data are also presented to provide a detailed history of a BVI event. In addition, a method of isolating the bound circulation and vortex induced effects is presented, from which it is concluded that for a BVI event the vortex-induced effects are (to a first approximation) independent of rotor pitch setting.
Effect of cut-outs on underexpanded rectangular jets
Authors: Elangovan S. , Rathakrishnan E.
Published: February 2023

The flowfield characteristics of jets from plain and rectangular orifices with semi-circular cut-outs have been experimentally investigated for both sonic and underexpanded conditions. Detailed pitot pressure measurements revealed that the cut-outs had a strong influence on the emerging flowfield. The rectangular orifice with cut-outs at the minor axis ends showed more effective mixing with shorter core lengths and faster near field jet decay when compared with the plain rectangular and the rectangular orifice with cut-outs at the major axis ends. The general trend of variation of shock cell length with fully expanded Mach number was consistent with Tam's theory, but the shock cell length of orifice jets were less than that predicted by Tam.
Identification of non-linear derivative models from Bo 105 flight test data
Authors: Rohlfs M.
Published: February 2023

This paper describes the results of a study focusing on the possibility of identifying nonlinear helicopter models in the time domain. In recent years, identification techniques working mainly in the frequency domain were applied to estimate the parameters in helicopter models. Recently, the time domain identification method of the DLR was improved to allow the identification of fully nonlinear models. To investigate the applicability of this method to helicopters, a nonlinear derivative model with explicit equations for the individual blade flapping angles was formulated. In comparison to the linear derivative models nonlinear models are physically more realistic and are not restricted by small perturbation assumptions. Although a large number of unknowns had to be determined, a nonlinear model was successfully identified.
On the equations of motion for an aircraft with an internal moving load which is then dropped
Authors: Bernstein L.
Published: February 2023

Equations of motion have been developed for the situation in which a substantial load, carried internally by an aircraft, is drawn along a ramp by an extraction parachute and is then dropped. The motion of the load is assumed to remain in the plane of symmetry. The perturbations to the aircraft motion are assumed to be small so that the equations can be linearised following the representation of the aerodynamic out-of-balance forces using conventional aerodynamic derivatives. The resulting system of six ordinary differential equations consists of the four normally associated with the longitudinally-perturbed motion of the aircraft (slightly modified by the reaction forces due to the load), together with two describing the motion of the load.

Numerical solutions are presented for a generic aircraft, the investigation examining the effects of a number of different parameters such as the ratio of the mass of the load to that of the aircraft, the length and angle of the ramp, the friction between the load and the ramp and the direction of the parachute extraction force. In addition the effects of employing various control strategies to limit the disturbed motion have also been computed.

It was found that the acceleration of the load, relative to the aircraft, was sensibly constant. In the absence of any resetting of the controls (elevators and throttle), the disturbances computed exceeded those for which the linearisation is justified. When the controls were reset, either as the load began to move or as it was jettisoned, to the trim values appropriate to the unloaded aircraft flying at the same speed, the disturbances were reduced, but remained large, the phugoid mode being dominant. The incorporation of various kinds of feedback from the disturbance variables to the elevator was also investigated and a successful control strategy was identified, that limited the perturbations and minimised the steady-state errors in airspeed and angle of climb.
Combined effect of wall suction and riblets on a low Rθ turbulent boundary layer
Authors: Djenidi L. , Antonia R. A. , Hundseid J. , Krogstad P. A.
Published: February 2023

A low Reynolds number turbulent boundary layer is subjected to a relatively strong rate of suction, which is applied through a short porous strip. Downstream of the strip, the effectiveness of a riblet surface is assessed by comparison,to that of a smooth wall. Measured mean velocity and longitudinal turbulence intensity profiles indicate that the riblets do not hinder the action the suction can have on the flow.
A note on the Prandtl number effect on laminar heat transfer and recovery
Authors: van Oudheusden B. W.
Published: February 2023

A critical revision is made of the classic power-law expressions that describe the effect of the Prandtl number on laminar heat transfer and temperature recovery for Pr near one, by applying a perturbation analysis to the energy equation for constant-property flow. In this way, the Pr dependence is obtained as a systematic asymptotic expansion up to any desired order, which provides a more accurate and convenient procedure than classic curve-fitting methods. The effect of pressure gradient and flow sweep are examined for self-similar yawed wedge flows.
A methodology for the preliminary analysis and comparison of wing-tail and canard configurations
Authors: Lombardi G. , Mengali G.
Published: February 2023

A methodology for the analysis of the performance of different aircraft configurations in the conceptual design phase is addressed. A scalar objective function, takeoff weight, is minimised by means of a numerical optimisation technique which takes into account the high number of geometrical parameters and the flight mechanics requirements involved in the problem. The study is confined to the cruise segment of the mission, and results are shown both for tail-aft and canard configurations. The above technique produces “equally” optimised configurations, thus giving a meaningful means to compare tail-aft and canard configurations.
Close spacing of settling chamber screens
Authors: Hancock P. E. , Johnson A. E.
Published: February 2023

Screen separations as little as 0.02 chamber diameters do not adversely affect suppression of mean-flow non-uniformity provided the overall pressure drop coefficient, K, does not exceed about 3.5. At larger K a velocity overshoot develops near the wall boundary layers, which decreases only slowly with wider separation. A simple approximate extension can be made to the theory of Taylor and Batchelor for any number of closely-spaced screens. This shows good agreement with measurements and with low-drag screens predicts perfect attenuation when the overall pressure-drop coefficient is 3.2 or 7.6. Some inferences regarding the effect of close screens on turbulence suppression are also drawn.
Homogeneous wall boundary condition for oscillatory flow in slotted tunnels
Authors: Mabey D.G.
Published: February 2023

The aerodynamic interference between oscillating models and the walls of slotted windtunnels is controlled by the homogeneous wall boundary condition, which has hitherto been uncertain. In this report a new homogeneous boundary condition for slotted tunnels is suggested which incorporates the important effects of plenum chamber depth and slot parameter.

In particular, this new boundary condition controls the transverse resonance frequencies of the tunnel, which represent a severe form of wall interference. Hence a comparison of measured resonance frequencies with predictions based on such a boundary condition provides a good test of its correctness.

The new homogeneous boundary condition complements that obtained previously for a perforated tunnel and is essentially similar in character. The boundary condition is applicable to oscillatory flows at frequencies ranging from quasi-steady values to multiples of the first resonance frequency.
Measurements of velocities in the near field of a lobed forced mixer trailing edge
Authors: Yu S. C. M. , Yip T. H.
Published: February 2023

Previous experimental studies have shown that the development of flow behind the trailing edge of a lobed forced mixer is greatly influenced by the formation of large-scale streamwise vortices. The main objective of the present study is to establish quantitatively the presence and role of the streamwise vortices in the mixing layer in the near field of a lobed forced mixer trailing edge. The near field was defined as the region within five wavelengths (of the trailing edge profile) from the trailing edge. A two-stream mixing layer with a velocity ratio of 0.6 was generated with initially turbulent boundary layers and nominally two-dimensional flow. Mean flow and turbulence measurements were made on fine cross-plane grids across the wake region and at several streamwise locations using a two-component laser-doppler anemometer. Production of turbulent kinetic energy existed in most parts of the near field enhancing the overall mixing process. The streamwise vortex development underwent a three-step process by which it was formed, intensified and quickly dissipated towards the end of the near field. The distance between two rows of streamwise vortices of alternate signs within a lobe reduced with downstream distance causing the amalgamation and annihilation of the vortices. Analysing this movement of vortices, based on inviscid vortex dynamics, suggested that the normal vortices shed at the trailing edge had actually provided a squeezing (pinched off) effect to two adjacent rows of streamwise vortices within a lobe, forcing them to interact with each other.
Two-dimensional implicit flux split steady and unsteady Euler calculations using unstructured moving grids
Authors: Sinhamahapatra K. P. , Singh N.
Published: February 2023

Two-dimensional Euler equations are solved on unstructured triangular meshes using commonly available minicomputers. The driving algorithm is an upwind biased implicit cell-centred finite volume scheme. The spatial discretisation involves a naturally dissipative flux-split approach that sharply captures Shockwaves. The grid generation method uses a type of advancing front technique which triangulates a given set of points. To demonstrate the application, the steady flow results are presented for single and two component aerofoils. The unsteady results are obtained using a dynamic mesh algorithm for an aerofoil pitching harmonically about the quarter chord. The paper presents a description of the grid generation and movement algorithm and of the Euler solver, along with results and comparison that assess their capabilities.
Seeking Protection and Reconciliation: A Pashtun Legal Custom in Recorded Tribal Histories
Authors: Pelevin Mikhail
Published: February 2023

Available essays on Pashtunwali describe this system of customary laws and ethics for the most part as a static model of ideal conduct, without a diachronic perspective. Offering a historical approach to Pashtunwali, this article introduces and analyzes fragmentary data on the nənawāte custom from early modern Pashto sources—historiographical narratives of the Khatak chieftains in the Tarikh-i Murassaʿ (finished 1724) and the romantic poem Adam Khan aw Durkhaney (1706/7). Recorded cases of resorting to nənawāte, considered among the main pillars of Pashtunwali but still variously interpreted, prove that this is a complex legal custom based on the right to appeal for protection, mediation, and reconciliation. As a common means of dispute settlement, nənawāte originates with a binding request for help and favor in a conflict situation. The discussion of nənawāte is preceded by a brief overview of the existing scholarly definitions of Pashtunwali, underscoring its emic perception as an ethnic identity marker.
Escape from Zanzibar: Refugees, Documents, and the Indian Ocean Shipping Regime
Authors: Limbert Mandana E.
Published: February 2023

In January 1964, on the heels of its formal independence from Britain, the East African island of Zanzibar exploded in a violent uprising ousting the Al-Bu Saidi sultan—an Omani by descent—and his primarily “Arab” government. Though early reports of the revolution did not indicate targeted attacks against Arabs, it soon became clear that thousands of Arab-identified residents—settlers—were killed, mostly in rural areas.1 Others, including some families I came to know during my years in interior Oman, described being separated from their families or being captured and taken to detention camps, where they stayed a week or two before being reunited. Some found their way to these camps in search of relatives, shelter, and food.2 Decades later, the chaos and violence of that time was recounted to me with unnerving directness. Eventually, thousands of Arabs were deported or fled—to Kenya, Dubai and Abu Dhabi, Egypt, Saudi Arabia, and Muscat and Oman. Muscat, on the coast of Oman, was the seat of the other Al-Bu Saidi sultan—a cousin of the Zanzibar sultan—who had only recently taken control of “Oman proper,” the territory of the Imamate whose ruler was now in exile in Saudi Arabia having been defeated in a war with the Sultan of Muscat. In the meantime, those leaving Zanzibar required ships and documents.
One for All? State Violence and Insurgent Cohesion
Authors: Schubiger Livia Isabella
Published: February 2023

What effect does state violence have on the cohesiveness and fragmentation of insurgent organizations? This article develops a theory of how state violence against civilians affects insurgent cohesion and fragmentation in civil war. It argues that the state-led collective targeting of an armed group's alleged civilian constituency increases the probability of insurgent fragmentation, defined as the process through which insurgent organizations split into distinct entities, each with its own social composition, goals, and leadership. This effect is driven by the interaction of several mechanisms at the individual, group, and organizational levels: state-led collective targeting enlarges the supply of fresh recruits, strengthens the bonds between immediate group members (interpersonal cohesion), and disrupts intra-organizational coordination, strategic unity, and institutional arrangements that underpin the commitment of individual fighters to the organization as a whole (ideological cohesion). The implications of this argument are empirically tested in an analysis of armed groups fighting against their governments between 1946 and 2008. The results suggest that campaigns of massive state violence directed against the civilian constituency of rebel groups increase the overall risk of insurgent fragmentation, a finding that has important implications for the duration and escalation of civil wars.
Patent Trolls and the Market for Acquisitions
Authors: Dayani Arash
Published: February 2023

I study the effect of patent-infringement claims by patent trolls on acquisitions of small firms. Exploiting staggered adoption of state anti-patent troll laws, I find that the laws have two effects. First, the number of acquisitions of small firms declines after these laws are adopted. Second, the anti-troll laws increase the acquisition price for acquirers. The market reflects the increased cost of acquisition as measured by lower acquisition announcement returns. Large firms increase R&D after the adoption of state laws, replacing external innovation. Using a sample of acquisitions that are plausibly unaffected by the laws, I disentangle alternative explanations.
Improving adolescents' dietary behaviours in the school-setting: challenges and opportunities
Authors: Devine Lauren D. , Hill Alyson J. , Gallagher Alison M.
Published: February 2023

Adolescence is a critical time of physical, psychological and social development, and thus, optimal nutritional intakes are required during this life stage. Despite this, adolescence is recognised as a period of nutritional vulnerability, with many reportedly failing to meet current dietary guidelines. The school-setting presents a favourable environment to intervene and promote positive dietary behaviours and is also inclusive regardless of socio-economic status. However, a lack of consensus exists on how best to utilise schools to facilitate improvements in dietary behaviours among this age group. Whilst previous research has focused on identifying the factors motivating dietary choices within the school-setting, less is known on the optimum strategies to enhance these dietary choices which could positively contribute to the design of future interventions. It is reported that adolescents have good nutritional knowledge, although this does not appear to be a central consideration when making their dietary choices. Alternative factors at the individual (taste, visual appeal, familiarity, food quality, price, portion size, value for money, time/ convenience), social (peer influence), physical (product placement) and macro environment (food availability) levels have been frequently cited as important influences on adolescents' dietary choices in school. Although school-based interventions have shown potential in achieving positive dietary change among adolescents, more research is needed to determine the most effective methods in improving dietary behaviours in schools. This review summarises the key factors which influence adolescents' school-based dietary choices and the effectiveness of previously conducted interventions, identifying promising components for consideration when developing future dietary interventions within the school-setting.
Relative Richardson varieties
Authors: CHAN MELODY , PFLUEGER NATHAN
Published: February 2023

A Richardson variety in a flag variety is an intersection of two Schubert varieties defined by transverse flags. We define and study relative Richardson varieties, which are defined over a base scheme with a vector bundle and two flags. To do so, we generalise transversality of flags to a relative notion, versality, that allows the flags to be non-transverse over some fibers. Relative Richardson varieties share many of the geometric properties of Richardson varieties. We generalise several geometric and cohomological facts about Richardson varieties to relative Richardson varieties. We also prove that the local geometry of a relative Richardson variety is governed, in a precise sense, by the two intersecting Schubert varieties, giving a generalisation, in the flag variety case, of a theorem of Knutson–Woo–Yong; we also generalise this result to intersections of arbitrarily many relative Schubert varieties. We give an application to Brill–Noether varieties on elliptic curves, and a conjectural generalisation to higher genus curves.
Random feedback shift registers and the limit distribution for largest cycle lengths
Authors: Arratia Richard A. , Canfield E. Rodney , Hales Alfred W.
Published: February 2023

For a random binary noncoalescing feedback shift register of width$n$, with all$2^{2^{n-1}}$possible feedback functions$f$equally likely, the process of long cycle lengths, scaled by dividing by$N=2^n$, converges in distribution to the same Poisson–Dirichlet limit as holds for random permutations in$\mathcal{S}_N$, with all$N!$possible permutations equally likely. Such behaviour was conjectured by Golomb, Welch and Goldstein in 1959.
ADAM SMITH ON PUBLIC PROVISION OF EDUCATION
Authors: Otteson James R.
Published: February 2023

Most Adam Smith scholars hold that Smith endorsed public provision of education to offset deleterious consequences arising from the division of labor. Smith’s putative endorsement of publicly funded education is taken by some scholars as evidence that he tends more toward progressive than classical liberalism, or that this is a departure from, perhaps an inconsistency with, Smith’s otherwise strong presumption against government intervention in markets. This paper argues that these interpretations are flawed because Smith ultimately does not advocate public provision of education. He raises the idea and explores its potential benefits, but he ultimately does not endorse it. Smith also provides reason to be skeptical of public provision of education, which suggests that his final position may have inclined against it.
Energy and international business cycles
Authors: Kim Myunghyun
Published: February 2023

US output is more strongly correlated with the output of energy-exporting countries than with that of energy-importing countries. I first document this empirical finding, then construct a three-country model in which countries’ different energy production and trade structures are considered. The three countries are the USA (an energy importer), a non-US energy importer, and an energy exporter. Consistent with the empirical findings, the model produces a higher output correlation between the USA and the energy exporter than between the USA and the energy importer. A positive productivity shock in the USA, raising its output, leads to increases in energy prices and its import demand for energy. The increased energy prices adversely influence output in the energy importer, whereas the rise in US energy imports has positive effects on output in the energy exporter, enabling the correlation of US output with the exporter’s output to be higher.