Longitudinal Structure Research Articles

Studying dimensions of representation: introducing the Belgian RepResent panel (2019–2021)

This research note presents the RepResent Belgian Panel (RBP). The RBP is a voter panel survey consisting of four waves fielded to a sample of voters in Belgium around the May 2019 federal, regional, and European elections in Belgium. It provides unique data on about 250 variables for a quota sample of the same respondents, pre-2019 elections (N = 7351), post-2019 elections (N = 3909), one year after the elections (N = 1996), and 2 years after the elections (N = 1119). The RBP panel dataset was designed to analyse voters’ political attitudes and behaviours, notably on different dimensions of democratic representation, and with a specific focus on democratic resentment (e.g. citizens’ attitudes towards democracy such as distrust and alienation, but also behaviours such as abstention, protest, or voting for anti-establishment parties). Its longitudinal structure allows to explore the political dynamics at play in Belgium throughout the lengthy government formation process. Finally, the last two waves of the RBP were fielded during the Covid-19 pandemic, allowing to explore public opinion before and during this global crisis. The RBP should be of interest to scholars of public opinion and electoral studies.

Investigation of the Formation and Further Development of Longitudinal Disturbances and Their Secondary Instability on the Flying Wing Model

Detailed investigation of two-dimensional roughness element influence on the flow behind three-dimensional roughness element was carried out. For the first time studies were conducted on the windward side of the flying wing in the range of free-stream 7,2 – 20 m/s in the favourable gradient region behind roughness elements. Secondary instability mechanisms of disturbances leading to turbulence stage were investigated. It was shown that longitudinal structure forming behind three-dimensional roughness element grows downstream and has its trajectory slightly bend. The longitudinal structure consists of two stationary disturbances different in size. This can be explained by presence of cross flow and secondary disturbances leading to the transition. On the straight wing model, influence of the distributed suction on the stationary disturbance development was investigated and quantitatively determined. It was shown that suction is able to relaminarize the flow and eliminate the separation of the boundary layer.

Longitudinal Factor Structure of the Brief Psychiatric Rating Scale Among Incident Cases of Schizophrenia Attending a Nigerian Hospital.

Schizophrenia, from its early conceptualization, has been described in distinct clinical subtypes. However, these categories were found not to be stable phenotypes over time, hence the dimensional option, whereas at cross-sectional level, the dimensions of psychopathology have been replicated across studies; there is dearth of data on the longitudinal stability of the factor structure of the symptoms of schizophrenia in African populations. This study examined the longitudinal stability of the factor structure of the 18-item Brief Psychiatric Rating Scale (BPRS) across intervals of 16-week naturalistic treatment follow-up. Consecutive incident cases that fulfilled the criteria for schizophrenia were recruited into the study. After a baseline assessment, 160 incident cases of schizophrenia were followed up 4 weekly for indicators of symptomatic outcome for 16 weeks. The Brief Psychiatric Rating Scale (BPRS) assessments were conducted in clinical interviews and with the Scale for Assessment of Negative Symptoms (SANS). Five BPRS assessments were made across the monthly intervals of follow-up. Exploratory factor analyses (EFA) using maximum likelihood extraction and varimax rotation with Kaiser normalization was used to extract the factors. A four-factor structure was found at baseline, namely negative, positive, depressive/anxiety, and manic symptom dimensions. From week 4, the manic and anxiety/depression dimensions remained invariant over time, while negative and positive symptoms merged into a psychosis dimension that was invariant. The persistence of the mood dimensions supports the DSM-5 recommendation to include these dimensions in the assessment of schizophrenia psychopathology. The longitudinal emergence and invariance of the psychosis factor echo the idea of unitary psychosis and, along with the prominence of mood dimensions over time, reflect recent molecular genetic findings about the sharing of genes by schizophrenia and mood disorders.

A longitudinal gradient architecture achieves better tensile properties in Ti6242 alloy

Simultaneous increase in strength and ductility is obtained in Ti6242 alloys using a longitudinal gradient structure. Such architecture demonstrates strain hardening regarding the gradient layer's volume fraction (Vf). The maximum strain hardening is produced in the freestanding gradient layer (Vf = 100%). An extra strain hardening evidenced by the increased back stress occurs in gradient samples, which partly accounts for the concurrently improved properties. Additionally, more boundaries of the α/β plates in lamellar structure and increased dislocations in the primary α phase (αp) are responsible for the enhanced strength. In the gradient layer, such microstructural characteristics, including significant thinning of the β plates, the locally disappeared boundaries of αp and transformed β structure (βt), and the reduced property difference between deformed αp and βt, contribute as well on the ductility improvement. This work provides a guideline for manufacturing high-performance Ti alloys via microstructural regulation or gradient architecture.

The impact of patient safety incidents during hip and knee replacements on patients' health related quality of life: a before and after study using longitudinal data linked to patient-reported outcome measures.

The burden of patient safety incidents (PSIs) is often characterized by their impact on mortality, morbidity, and treatment costs. Few studies have attempted to estimate the impact of PSIs on patients' health-related quality of life (HRQoL) and the studies that have made such estimates primarily focus on a narrow set of incidents. The aim of this paper is to estimate the impact of PSIs on HRQoL of patients undergoing elective hip and knee surgery in England. A unique linked longitudinal data set consisting of patient-reported outcome measures for patients with hip and knee replacements linked to Hospital Episode Statistics (HES) collected between 2013/14 and 2016/17 was examined. Patients with any of nine US Agency for Healthcare Research and Quality (AHRQ) PSI indicators were identified. HRQoL was measured using the general EuroQol five dimensions questionnaire (EQ-5D) before and after surgery. Exploiting the longitudinal structure of the data, exact matching was combined with difference in differences to estimate the impact of experiencing a PSI on HRQoL and its individual dimensions, comparing HRQoL improvements after surgery in similar patients with and without a PSI in a retrospective cohort study. This design compares the change in HRQoL before and after surgery in patients who experience a PSI to those who do not. The sample comprised 190697 and 204649 observations for patients undergoing hip replacement and knee replacement respectively. For six out of nine PSIs, patients who experienced a PSI reported improvements in HRQoL that were 14-23% lower than those who did not experience a PSI during surgery. Those who experienced a PSI were also more likely to report worse health states after surgery than those without a PSI on all five dimensions of HRQoL. PSIs are associated with a substantial negative impact on patients' HRQoL.

Psychosocial safety climate: Measurement and relationship with well-being in a four-wave longitudinal study during remote work.

To create healthy workplaces, organizations need tools for assessing factors contributing to employee well-being. Psychosocial safety climate (PSC) refers to shared perceptions regarding the extent to which psychological health and safety are prioritized in organizations; it is operationalized in the PSC scale. We evaluated the factor structure of the Finnish version of the PSC-4 scale, its invariance across time and concurrent and predictive relationships with perceived stress, job exhaustion, and work engagement. Moreover, the mean-level changes in PSC and well-being during enforced remote work were studied. Participants were 442 higher education employees who completed a well-being survey four times between April 2020 and February 2021. The longitudinal factor structure of the PSC-4 and well-being indicators were investigated using confirmatory factor analysis and structural equation modeling. The statistical analyses supported the one-factor structure of the PSC-4 and its measurement invariance across time. PSC was negatively associated with concurrent stress and job exhaustion and positively associated with concurrent work engagement at each measurement. Moreover, PSC predicted subsequent stress between each time point. Cross-lagged effects were also evident for job exhaustion at T2-T3 and T3-T4 and for work engagement at T1-T2. The mean level of PSC decreased during enforced remote work. To conclude, the Finnish PSC-4 is a valid tool for evaluating perceived psychosocial safety climate in organizations. PSC predicted well-being over time and showed subsequent relationships with job exhaustion and work engagement, which is a new contribution to PSC theory and literature. Organizations need to design interventions to improve it, especially during stressful times.

Longitudinal structures of zonal wind in the thermosphere by the ICON/MIGHTI and the main wave sources

In this study, the neutral wind observations from the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument onboard Ionospheric CONnections (ICON) are used to investigate the longitudinal structure of zonal wind between 100 and 300 km during daytime. The four-peaked structure in the longitudinal distribution between June and August is visually clear in the whole altitudinal range. The longitudinal wavenumber 1–4 patterns (WN1–WN4) are extracted, and the altitude–month distributions of WN1–WN4 and their contributions to the longitudinal structure are compared. The amplitudes of WN3 and WN4 show seasonal dependence, and the amplitude of WN4 exhibits obvious vertical propagation from the mesosphere and lower thermosphere (MLT) to the upper thermosphere in summer and autumn. WN1 is an important contributor to the longitudinal structure, WN4 is the primary contributor in the lower altitude ranges in summer and autumn at three latitudes. The contributions of WN3 (WN1) increase holistically with latitude in summer (spring, autumn, and winter). And the main wave sources of WN1–WN4 are further investigated in the 100–106 km and 210–300 km altitude regions. The main wave sources of WN1 and WN2 have complex variations with altitude, latitude, and season, while WN3 (WN4) is clearly influenced by DE2 (DE3 and SE2).Graphical

Imaging an Enigmatic Paleovalley with Passive Seismic Methods (Unaweep Canyon, Colorado, United States)

Abstract High-resolution passive seismic imaging of shallow subsurface structures is often challenged by the scarcity of coherent body-wave energy in ambient noise recorded at surface stations. We show that the autocorrelation (AC) of teleseismic P-wave coda extracted from just one month of continuous recording at 5 Hz geophones can overcome this limitation. We apply this method to investigate the longitudinal subsurface bedrock structure of Unaweep Canyon—a paleovalley in western Colorado (United States) with complex evolution. Both fluvial and glacial processes have been proposed to explain the canyon’s genesis and morphology. The teleseismic P-wave coda AC retrieves zero-offset reflections from the shallow (200–500 m depth) basement interface at 120 stations along a 5 km long profile. In addition, we invert interferometrically retrieved surface-wave dispersion for the shear-wave structure of the sedimentary fill. Combined interpretation of these results and other geophysical and well data suggests an overdeepened basement geometry most consistent with glacial processes.

A dynamic perspective on the evolution of perceived stress levels in Switzerland: drivers before and during the COVID-19 pandemic.

As a major socio-historical event affecting different aspects of life, the COVID-19 pandemic presents a unique opportunity to study how different population groups adapt. We investigate the impact of this crisis on the evolution of perceived stress in the short and medium term in Switzerland, using data of the Swiss Household Panel from 2016 to early 2021, which include annual measures of perceived stress and a study between waves, conducted in May and June 2020 at the end of the first semi-lockdown. Using the longitudinal structure of the data with pre-crisis measurements, we estimate pooled OLS, fixed effects and first difference models, which include socio-demographic variables, life events, socio-economic status, work-related variables, stress-reducing resources and restrictions in place. Results for the overall population show a continuous increase in stress levels between 2016 and 2019 and a stress reduction right after the first semi-lockdown followed by a return to pre-pandemic levels. Privileged groups with higher levels of stress before the pandemic were most likely to reduce perceived stress. Characteristics related to more favourable trajectories include stable or improved financial situations and high levels of education (short-term effects), and high-pressure jobs and working hours (short- and medium-term effects). Our analyses reveal the importance of resources, such as social relations and work-life balance, to individuals' management of the effects of the pandemic. Our results show that the effects of the pandemic on perceived stress are context-specific. They underline the importance of longitudinal analyses to understand the complexity of vulnerability and adaptation processes.

Regulating the Electronic Structure of Metal Nanoclusters by Longitudinal Single-Dithiolate Substitution.

It is significant but challenging to understand the property evolution of metal nanoclusters by orientated regulation of the electronic structure. Previous research has demonstrated that the optical properties of metal nanoclusters with anisotropic structures are greatly impacted by their longitudinal electronic structure. However, the manipulation of optical properties of metal nanoclusters by regulating their electronic structure through longitudinal dithiolate substitutions has not yet been reported. In this study, we first achieved the longitudinal single-dithiolate replacement of metal nanoclusters and obtained two novel nanoclusters: Au28(SPh-tBu)18(SCH2SCH2S) and Au28(SPh-tBu)18(SCH2CH2CH2S). Both experimental and theoretical results demonstrated the regulation of the electronic structure (dipole moment) in the z (longitudinal) and x directions, resulting in absorption redshift and photoluminescence (polarity) enhancement. These findings not only deepen the understanding of the property-electronic structure correlation of metal nanoclusters but also provide guidance for their subtle property tuning.

Development of fishing boat collision models in extreme weather using computer simulation

The incidence of fishing boat accidents in Indonesia is very worrying, with 342 people dying during 2018–2020. Based on this, it is crucial to investigate the construction strength of fishing vessels against the possibility of a collision. In this study, the fishing boat due to the impact load was investigated in extreme weather conditions using Finite Element Method (FEM) analysis. Traditional fishing boat was constructed by measuring the thickness of the hull, deck, keel, frames, and longitudinal structure of the fishing boat. The collision model is carried out with an impactor in the form of a mooring pole during extreme weather with a wave height of 6 meters and wind speeds 30 knots. Variations in velocity and frame spacing as in actual conditions are modeled to obtain differences in deformation, absorption energy values, and plasticity of boat construction due to collisions. The collision speed of 30 and 20 knots are set on the extreme weather conditions, while the collision speed of 7 knots is set on operating speed. Frame spacing of 0.5 and 0.6 meters is built according to the boat's frame spacing in the field. Computer simulation is carried out using application software ANSYS Research License. The fishing boat material used is mahogany wood with tested by using impact test with a toughness value of 39.1 kJ/m2. Based on the simulations results, the impact velocity has an effect deformation wider crash area and hull stress value. The speed of the ship collision was 7 knots, the collision did not damage the hull, but the construction failed at speeds of 20 and 30 knots. The closer of frame spacing, the higher collision performance of structure to withstand impact are indicated by the higher energy absorption. At a ship collision speed of 30 knots, the absorption energy of the construction at 0.5-meter frame spacing is 49.8 kJ, greater than 0.6-meter frame spacing with a value of 29.6 kJ

Longitudinal structure of Earth’s magnetic field controlled by lower mantle heat flow

Longitudinal structure of Earth’s magnetic field controlled by lower mantle heat flow

Moments and power corrections of longitudinal and transverse proton structure functions from lattice QCD

We present a simultaneous extraction of the moments of ${F}_{2}$ and ${F}_{L}$ structure functions of the proton for a range of photon virtuality, ${Q}^{2}$. This is achieved by computing the forward Compton amplitude on the lattice utilizing the second-order Feynman-Hellmann theorem. Our calculations are performed on configurations with two different lattice spacings and volumes, all at the $SU(3)$ symmetric point. We find the moments of ${F}_{2}$ and ${F}_{L}$ in good agreement with experiment. Power corrections turn out to be significant. This is the first time the ${Q}^{2}$ dependence of the lowest moment of ${F}_{2}$ has been quantified.

Numerical evaluation of the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu evolution equations for nuclear parton distribution functions

We numerically study for the first time the nonlinear GLR-MQ evolution equations for nuclear parton distribution function (nPDFs) to next-to-leading order accuracy and quantify the impact of gluon recombination at small $x$. Using the nCTEQ15 nPDFs as input, we confirm the importance of the nonlinear corrections for small $x \lesssim 10^{-3}$, whose magnitude increases with a decrease of $x$ and an increase of the atomic number $A$. We find that at $x=10^{-5}$ and for heavy nuclei, after the upward evolution from $Q_0=2$ GeV to $Q=10$ GeV, the quark singlet $\Omega(x,Q^2)$ and the gluon $G(x,Q^2)$ distributions become reduced by $9-15$%, respectively. The relative effect is much stronger for the downward evolution from $Q_0=10$ GeV to $Q=2$ GeV, where we find that $\Omega(x,Q^2)$ is suppressed by 40%, while $G(x, Q^2)$ is enhanced by 140%. These trends propagate into the $F_2^A(x,Q^2)$ nuclear structure function and the $F_L^A(x,Q^2)$ longitudinal structure function, which after the downward evolution become reduced by 45% and enhanced by 80%, respectively. Our analysis indicates that the nonlinear effects are most pronounced in $F_L^A(x,Q^2)$ and are already quite sizable at $x \sim 10^{-3}$ for heavy nuclei. We have checked that our conclusions very weakly depend on the choice of input nPDFs. In particular, using the EPPS21 nPDFs as input, we obtain quantitatively similar results.

Polarization and phase control of electron injection and acceleration in the plasma by a self-steepening laser pulse

We describe an interplay between two injection mechanism of background electrons into an evolving plasma bubble behind an intense laser pulse: one due to the overall bubble expansion, and another due to its periodic undulation. The two mechanisms occur simultaneously when an intense laser pulse propagating inside a plasma forms a shock-like steepened front. Periodic undulations of the plasma bubble along the laser propagation path can either inhibit or conspire with electron injection due to bubble expansion. We show that carrier-envelope-phase (CEP) controlled plasma bubble undulation induced by the self-steepening laser pulse produces a unique electron injector—expanding phase-controlled undulating bubble (EPUB). The longitudinal structure of the electron bunch injected by the EPUB can be controlled by laser polarization and power, resulting in high-charge (multiple nano-Coulombs) high-current (tens of kilo-amperes) electron beams with ultra-short (femtosecond-scale) temporal structure. Generation of high-energy betatron radiation with polarization- and CEP-controlled energy spectrum and angular distribution is analyzed as a promising application of EPUB-produced beams.

Higher twists effects in DIS on nuclei at the EIC and LHeC: a phenomenological analysis

In this paper we investigate the impact of the higher - twist effects, resummed by the non - linear approaches for the QCD dynamics, on the inclusive observables that will be measured in future electron - ion colliders. We assume a phenomenological model for the dipole - nucleus scattering amplitude which takes into account the non - linear corrections and estimate the contribution of the different twists for $F_2^A(x,Q^2)$, $F_L^A(x,Q^2)$ and $\partial F_2^A /\partial ln Q^2$ considering different values of the Bjorken - $x$ variable, photon virtuality $Q^2$ and atomic number $A$. A comparison with the full predictions is performed and the impact of the distinct twists is estimated. Our results indicate that a future analysis of the logarithmic $Q^2$ slope and longitudinal structure function will allow us to probe the presence of the non - linear effects on the QCD dynamics.

Visualizing Collagen Fibrils in the Cochlea's Tectorial and Basilar Membranes Using a Fluorescently Labeled Collagen-Binding Protein Fragment.

A probe that binds to unfixed collagen fibrils was used to image the shapes and fibrous properties of the TM and BM. The probe (CNA35) is derived from the bacterial adhesion protein CNA. We present confocal images of hydrated gerbil TM, BM, and other cochlear structures stained with fluorescently labeled CNA35. A primary purpose of this article is to describe the use of the CNA35 collagen probe in the cochlea. Recombinant poly-histidine-tagged CNA35 was expressed in Escherichia coli, purified by cobalt-affinity chromatography, fluorescence labeled, and further purified by gel filtration chromatography. Cochleae from freshly harvested gerbil bullae were irrigated with and then incubated in CNA35 for periods ranging from 2h - overnight. The cochleae were fixed, decalcified, and dissected. Isolated cochlear turns were imaged by confocal microscopy. The CNA35 probe stained the BM and TM, and volumetric imaging revealed the shape of these structures and the collagen fibrils within them. The limbal zone of the TM stained intensely. In samples from the cochlear base, intense staining was detected on the side of the TM that faces hair cells. In the BM pectinate zone, staining was intense at the upper and lower boundaries. The BM arcuate zone was characterized by a prominent longitudinal collagenous structure. The spiral ligament, limbus and lamina stained for collagen, and within the spiral limbus the habenula perforata were outlined with intense staining. The CNA35 probe provides a unique and useful view of collagenous structures in the cochlea.

Simple model for the bottleneck effect in isotropic turbulence based on Kolmogorov's hypotheses

We propose a simple model for the bottleneck effect in isotropic turbulence based on Kolmogorov's hypotheses. The model of the longitudinal structure function consists of two quadratic functions representing large- and small-scale motions, with parameters derived from asymptotic behaviors of the structure function. The model shows a decaying power law for the bump height in the compensated spectrum, which agrees with the result of direct numerical simulations at a range of Reynolds numbers.

Numerical investigation of azimuthal thermoacoustic instability in a gas turbine model combustor

Self-excited spinning mode azimuthal instability in an annular combustor with non-swirling flow is investigated using large eddy simulation (LES). Compressible Navier–Stokes equations are solved with a flamelet combustion model to describe the subgrid chemistry-turbulence interactions. Two flamelet models, with and without heat loss effects, are compared to elucidate the non-adiabatic wall effects on the thermoacoustic instability. The azimuthal modes are captured well by both models with only marginal differences in the computed frequencies and amplitudes. By comparing with the experimental measurements, the frequencies given by the LES are approximately 10% higher and the amplitudes are well predicted. Further analysis of the experimental and LES data shows a similar dominant anti-clockwise spinning mode, under which a good agreement is observed for the phase-averaged heat release rate fluctuations. Dynamic mode decomposition (DMD) is applied to shed more light on this spinning mode. The LES and experimental DMD modes reconstructed for their azimuthal mode frequencies agree very well for the heat release fluctuations. The DMD mode structure for the acoustic pressure from the LES shows a considerable non-zero profile at the combustor outlet, which could be essential for azimuthal modes to establish in this annular combustor. Finally, a low-order modelling study was conducted using an acoustic network combined with the flame transfer function extracted from LES. The results show that the dominant mode is associated with the plenum showing a first longitudinal and azimuthal mixed mode structure. By tuning the plenum length to match the effective volume, the predicted frequency becomes very close to the measured value.

Psychopathological networks in psychosis: Changes over time and clinical relevance. A long-term cohort study of first-episode psychosis

BackgroundFirst-episode psychosis is a critical period for early interventions to reduce the risk of poor outcomes and relapse as much as possible. However, uncertainties about the long-term outcomes of symptomatology remain to be ascertained. MethodsThe aim of the present study was to use network analysis to investigate first-episode and long-term stages of psychosis at three levels of analysis: micro, meso and macro. The sample was a cohort of 510 patients with first-episode psychoses from the SEGPEP study, who were reassessed at the long-term follow-up (n = 243). We used the Comprehensive Assessment of Symptoms and History for their assessments and lifetime outcome variables of clinical relevance. ResultsOur results showed a similar pattern of clustering between first episodes and long-term follow-up in seven psychopathological dimensions at the micro level, 3 and 4 dimensions at the meso level, and one at the macro level. They also revealed significant differences between first-episode and long-term network structure and centrality measures at the three levels, showing that disorganization symptoms have more influence in long-term stabilized patients. ConclusionsOur findings suggest a relative clustering invariance at all levels, with the presence of two domains of disorganization as the most notorious difference over time at micro level. The severity of disorganization at the follow-up was associated with a more severe course of the psychosis. Moreover, a relative stability in global strength of the interconnections was found, even though the network structure varied significantly in the long-term follow-up. The macro level was helpful in the integration of all dimensions into a common psychopathology factor, and in unveiling the strong relationships of psychopathological dimensions with lifetime outcomes, such as negative with poor functioning, disorganization with high antipsychotic dose-years, and delusions with poor adherence to treatment. These results add evidence to the hierarchical, dimensional and longitudinal structure of psychopathological symptoms and their clinical relevance in first-episode psychoses.