Positive Drift Research Articles

Time trends in anxiety disorders incidence across the BRICS: an age-period-cohort analysis for the GBD 2021.

Anxiety disorders are a significant global mental health concern, contributing to substantial disability-adjusted life years (DALYs) and imposing considerable social and economic burdens. Understanding the epidemiology of anxiety disorders within the BRICS nations (Brazil, Russian Federation, India, China, and South Africa) is essential due to their unique socio-economic landscapes and ongoing transformations. This study utilized data from the Global Burden of Disease (GBD) 2021 database to evaluate anxiety disorder incidence trends in BRICS countries from 1992 to 2021. The Age-Period-Cohort (APC) model with an intrinsic estimator (IE) algorithm was employed to disentangle the effects of age, period, and cohort on incidence rates. Data were categorized into 5-year age groups, and 95% uncertainty intervals (UIs) were calculated to account for data variability. From 1992 to 2021, the global number of anxiety disorders cases increased by 73.44%, with age-standardized incidence rates rising by 21.17%. Among BRICS nations, India experienced the largest increase in cases (113.30%), while China had the smallest increase (2.79%). Globally, young (15-49 years) and oldest (80-94 years) age groups showed predominantly positive local drift values, indicating rising incidence rates. Brazil and India mirrored this trend, while China and South Africa mostly exhibited negative local drift values. Russia Federation had mixed trends with younger groups showing negative and older groups positive local drift values. The incidence of anxiety disorders exhibited an "M-shaped" age pattern with peaks at 10-14 and 35-39 years. Period effects were stable globally but varied in BRICS countries, with Brazil showing a decline and India an increase. Cohort effects were stable globally but showed increasing trends in Brazil and India post-1955-1959 cohort. This study highlights a significant increase in anxiety disorders incidence globally and within BRICS nations over the past three decades, with marked variations across countries. The distinct trends observed in age, period, and cohort effects call for age-specific and gender-sensitive mental health policies. Continuous monitoring, research, and tailored public health strategies are essential to address the rising burden of anxiety disorders and improve mental health outcomes in these rapidly evolving regions.

Research of scale effect on propeller bearing force of a four-screw ship in oblique flow

To study the scale effect on propeller bearing forces in oblique flow, the propeller bearing forces of a fully appended four-screw ship that refers to a vessel propelled by four propellers are calculated and investigated. The findings reveal that scale effects in wake fields lead to an increase in the axial velocity of the propeller disk in the full-scale ship compared to the model, influenced by boundary layer flow. Moreover, asymmetric differences in the impact of oblique flow on the leeward and windward sides result in varied effects of positive and negative drift angles on the wakefield. The disparity in wake fields between inside and outside disks exacerbates unbalanced load distribution, with time-averaged loads showing an increase with drift angle for both propellers at full scale. Additionally, pronounced scale effects lead to variations in blade loads between model and full scale, with drift angles shifting the locations of single-blade load extremums. Unsteady bearing force components exhibit periodic fluctuations, with larger amplitudes at the blade passage frequency for the model scale propeller compared to the full scale, particularly evident under negative drift angles. The aforementioned findings can provide theoretical guidance for load balancing and vibration reduction of the four-screw ships.

Characterisation of an LED-based integrating sphere source for detection of changes of AERONET Europe radiometers

Abstract Within the framework of the EMPIR project 19ENV04 MAPP “Metrology for aerosol optical properties” an LED-based source was built for monitoring responsivity changes of Cimel filter radiometers from the AERONET Europe network. The developed LED device was flanged to integrating spheres to fill the field of view of the radiometers. Here we present the characterisation results of the LED-based integrating sphere source. The spectra of the radiant flux leaving a BaSO4-based integrating sphere showed positive wavelength dependent drift, which had not been reported in literature yet and did not appear by using incandescent lamps with the integrating spheres. This report shows approaches to reduce such drifts and an alternative using a PTFE-based integrating sphere, which was also tested for stability, reproducibility and homogeneity.

Tectono-sedimentary evolution and oil-gas geological significance of first to third member of Ordovician Majiagou Formation in Ordos Basin, NW China

Based on logging, core, thin section and geochemical analysis, the tectonic-lithofacies paleogeographic pattern of first member to third member of Ordovician Majiagou Formation (O1m1–O1m3 for short) in Ordos Basin is reconstructed, and the tectono-sedimentary evolution characteristics and oil-gas geological significance are discussed. The results are obtained in four aspects. First, a set of marginal argillaceous dolomites with high gamma ray value developed steadily and diachronously at the bottom of Majiagou Formation, which distributed over the Huaiyuan Movement unconformity, with δ13C values positive drift characteristics comparable to global transgression of the Early Ordovician Floplian. Second, the global sea level rose and the ancient land was submerged into the underwater uplift in O1m1 to O1m2, and the central uplift was deposited for the first time in the Ordovician, forming a tectonic pattern of “one uplift and two depressions”. Subsequently, the subduction and extrusion outside the basin and the differentiation of uplift and depression in the basin of O1m3 resulted in the activation of the Wushenqi–Jingbian bulge. Third, the evolution of the tectonic pattern had a significant impact on the sedimentary paleoenvironment. The O1m1 overlaps westward, and saline lagoon is formed in eastern depression and influenced by the transgression. The transgression continued in O1m2 and resulted in communication with the wide sea, and the large-scale grain shoal developed around eastern depression, and the late dry shrinkage formed a small scale evaporite lagoon in upper part. Under the influence of highland sealing in O1m3, the water body gradually differentiated into dolomitic gypsum and saline lagoons to the east, and the grain shoal spread along the highs around sag. Fourth, the source rocks developed diachronously at the bottom of Majiagou Formation form a favorable source-reservoir assemblage with the shoal facies reservoir distributed around the slope of O1m2–O1m3, and they have certain exploration potential for natural gas.

Global temporal trends and projections of acute hepatitis E incidence among women of childbearing age: Age-period-cohort analysis 2021

Acute Hepatitis E (AHE) poses a significant threat to global public health, particularly among women of childbearing age (WCBA), who are at heightened risk for severe pregnancy-related complications. This study aimed to delineate the temporal trends and project future incidence of AHE in WCBA, providing insights crucial for targeted prevention and control strategies. Data on AHE incidence from the Global Health data 2021. The Age-Period-Cohort (APC) model was applied to analyze trends across different age groups, periods, and birth cohorts, and the Bayesian APC model was utilized for forecasting future epidemiological trajectories. Globally, AHE incidence numbers among WCBA rose from 2,831,075 in 1992 to 3,420,786 in 2021, while the age-standardized incidence rate (ASIR) declined from 194.66 to 179.54 per 100,000 with a global net drift of -0.28%. However, high SDI regions showed a contrasting trend with a positive net drift of 0.02%. The age effect was consistent across SDI regions and global, showing a decrease with advancing age, while unfavorable period and cohort effects were exhibited in high-SDI region. At the national level, locations exhibited varying trends of change. The BAPC model predicted a total of 3,759,384 AHE global cases in WCBA by 2030, with an expected mild increase in the ASIR. The outlook for the management and containment of AHE is grim in certain countries, including India. The study revealed a complex epidemiological landscape of AHE in WCBA, with increasing global incidence numbers juxtaposed against a declining ASIR. The AHE burden by 2030 remain severe among WCBA. Young WCBA and high SDI region merit particular attention. The findings underscore the need for region-specific strategies to curb the projected rise in AHE incidence and align with the 2030 WHO goals.

Cyclic performance of precast hollow core slab to beam connections using innovative assembling technique

This study emphasizes the performance of novel assembling technique using anchored continuity bars as a connection detail between precast hollow core slab and beam, aiming to achieve faster assembly and increased efficiency. The study further conducts a detailed analysis of core rebar impact on the hollow core slab to beam connection, examining both the assembly technique and core rebar influence. Effectiveness assessment of newly introduced anchored continuity bars and core rebars utilized five full scale half span prototypes under reverse cyclic loading. Findings indicate that connections incorporating anchored continuity and core rebar exhibit high strength, less stiffness deterioration, high ductility, and substantial energy dissipation, thereby meeting seismic load requirements. All connections met ACI 374.1–05 criteria, demonstrating satisfactory performance in seismic tests concerning relative energy dissipation ratio and stiffness ratio criteria. Notably, the continuity bar anchored to beam reinforcement-core reinforcement anchored to beam with ties connection surpasses the continuity bar anchored to beam reinforcement connection, demonstrates a superior average peak load carrying capacity of 149.8 % and cumulative energy dissipation of 288.78 %. The study concluded that the innovative assembly using anchored continuity bar with the inclusion of core rebar in the voids contributes to the improvement of connection performance under positive drift moment capacity and partly enhances negative drift moment capacity, thereby enhancing the overall stability of floor units in the event of seat loss.

Weathering, redox proxies and carbon isotope data from the Maokou Formation, Upper Yangtze, South China: Implications for the Guadalupian P3 glaciation of the Late Paleozoic Ice Age

Late Paleozoic Ice Age (LPIA) was a key climate event of the deep-time earth evolution system. Although the sedimentary successions from eastern Australia have well constrained the timeframe of the glacial-nonglacial intervals, the link between these glaciations and coeval geological events is still being explored. The Guadalupian (Middle Permian) P3 glaciation was the prelude to the upcoming end of LPIA, which is a key window to examine the uncertainty of the climatic transition from icehouse to greenhouse and linkages with the geological and biological events. This study focuses on the marine sedimentary succession of the Shangsi outcrop located in the low-latitude Yangtze block, investigating the carbon/strontium isotopes, redox proxy, and chemical index of alteration (CIA). Multiple weathering indices revealed climatic fluctuations during the Guadalupian, corresponding to the onset and demise of the high-latitude P3 glaciation. The high level of CIA following the Kungurian-age Large Igneous Provinces (LIPs) event indicates that the weathering of basic rocks caused the positive 13C drift, which was the main factor for the onset of the P3 glaciation. Then the breakup of Pangea, enhanced ocean oxidation, and a series of volcanic activities including Emeishan LIP could contribute to the accumulation of CO2 and consequently cause the demise of the P3 glaciation in middle Capitanian. Enhanced continental weathering was synchronous with the eruption surge of the volcanic activities, indicating a following global warming event, which may play a crucial role in triggering the Mid-Capitanian extinction event.

Superdiffusive planar random walks with polynomial space–time drifts

We quantify superdiffusive transience for a two-dimensional random walk in which the vertical coordinate is a martingale and the horizontal coordinate has a positive drift that is a polynomial function of the individual coordinates and of the present time. We describe how the model was motivated through an heuristic connection to a self-interacting, planar random walk which interacts with its own centre of mass via an excluded-volume mechanism, and is conjectured to be superdiffusive with a scale exponent 3/4. The self-interacting process originated in discussions with Francis Comets.

A controller-stopper-game with hidden controller type

We consider a continuous time stochastic dynamic game between a stopper (the owner of an asset) and a controller (the manager) who is either effective or non-effective. An effective manager can exert high or low effort which corresponds to a high or a low positive drift for the accumulated income of the owner with random noise in terms of Brownian motion. The manager earns a salary until the owner stops the game. A non-effective manager cannot act but receives a salary. We find a threshold (Nash) equilibrium using stochastic filtering methods in a weak formulation.

Imaging a Large Coronal Loop Using Type U Solar Radio Burst Interferometry

Solar radio U-bursts are generated by electron beams traveling along closed magnetic loops in the solar corona. Low-frequency (<100 MHz) U-bursts serve as powerful diagnostic tools for studying large-sized coronal loops that extend into the middle corona. However, the positive frequency drift component (descending leg) of U-bursts has received less attention in previous studies, as the descending radio flux is weak. In this study, we utilized LOFAR interferometric solar imaging data from a U-burst that has a significant descending leg component, observed between 10 and 90 MHz on 2020 June 5th. By analyzing the radio source centroid positions, we determined the beam velocities and physical parameters of a large coronal magnetic loop that reached just about 1.3 R ⊙ in altitude. At this altitude, we found the plasma temperature to be around 1.1 MK, the plasma pressure around 0.20 mdyn, cm−2, and the minimum magnetic field strength around 0.07 G. The similarity in physical properties determined from the image suggests a symmetric loop. The average electron beam velocity on the ascending leg was found to be 0.21c, while it was 0.14c on the descending leg. This apparent deceleration is attributed to a decrease in the range of electron energies that resonate with Langmuir waves, likely due to the positive background plasma density gradient along the downward loop leg.

Trial- vs. cycle-level detrending in the analysis of cyclical biomechanical data

Biomechanical time series may contain low-frequency trends due to factors like electromechanical drift, attentional drift and fatigue. Existing detrending procedures are predominantly conducted at the trial level, removing trends that exist over finite, adjacent time windows, but this fails to consider what we term ‘cycle-level trends’: trends that occur in cyclical movements like gait and that vary across the movement cycle, for example: positive and negative drifts in early and late gait phases, respectively. The purposes of this study were to describe cycle-level detrending and to investigate the frequencies with which cycle-level trends (i) exist, and (ii) statistically affect results. Anterioposterior ground reaction forces (GRF) from the 41-subject, 8-speed, open treadmill walking dataset of Fukuchi (2018) were analyzed. Of a total of 552 analyzed trials, significant cycle-level trends were found approximately three times more frequently (21.1%) than significant trial-level trends (7.4%). In statistical comparisons of adjacent walking speeds (i.e., speed 1 vs. 2, 2 vs. 3, etc.) just 3.3% of trials exhibited cycle-level trends that changed the null hypothesis rejection decision. However 17.6% of trials exhibited cycle-level trends that qualitatively changed the stance phase regions identified as significant. Although these results are preliminary and derived from just one dataset, results suggest that cycle-level trends can contribute to analysis bias, and therefore that cycle-level trends should be considered and/or removed where possible. Software implementing the proposed cycle-level detrending is available at https://github.com/0todd0000/detrend1d.

Why is summertime Arctic sea ice drift speed projected to decrease?

Abstract. Alongside declining Arctic sea ice cover during the satellite era, there have also been positive trends in sea ice Arctic average drift speed (AADS) during both winter and summer. This increasing sea ice motion is an important consideration for marine transportation as well as a potential feedback on the rate of sea ice area decline. Earlier studies have shown that nearly all modern global climate models (GCMs) produce positive March (winter) AADS trends for both the historical period and future warming scenarios. However, most GCMs do not produce positive September (summer) AADS trends during the historical period, and nearly all GCMs project decreases in September AADS with future warming. This study seeks to understand the mechanisms driving these projected summertime AADS decreases using output from 17 models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6) along with 10 runs of the Community Earth System Model version 2 Large Ensemble (CESM2-LE). The CESM2-LE analysis reveals that the projected summertime AADS decreases are due to changes in sea surface height (SSH) and wind stress which act to reduce sea ice motion in the Beaufort Gyre and Transpolar Drift. During March, changes in internal stress and wind stress counteract tilt force changes and produce positive drift speed trends. The simulated wintertime mechanisms are supported by earlier observational studies, which gives confidence that the mechanisms driving summertime projections are likely also at work in the real world. However, the precise strength of these mechanisms is likely not realistic during summer, and additional research is needed to assess whether the simulated summertime internal stress changes are too weak compared to changes in other forces. The projected summertime wind stress changes are associated with reduced sea level pressure north of Greenland, which is expected with the northward shift of the jet streams. The projected summertime SSH changes are primarily due to freshening of the Arctic Ocean (i.e., halosteric expansion), with thermal expansion acting as a secondary contribution. The associated ocean circulation changes lead to additional piling up of water in the Russian shelf regions, which further reinforces the SSH increase. Analysis of CMIP6 output provides preliminary evidence that some combination of wind stress and SSH changes is also responsible for projected AADS decreases in other models, but more work is needed to assess mechanisms in more detail. Altogether, our results motivate additional studies to understand the roles of SSH and wind stress in driving changes in Arctic sea ice motion.

Let me sleep on it: sleep and investor reactions to earnings surprises

We explore if sleep deprivation affects how investors react to relevant news. Using the transition to Daylight Saving Time (DST) in spring as a disruption to sleeping patterns, we show that investors underreact to a firm’s earnings surprise in the days after the transition to DST. Further, an earnings surprise in the days after the transition to DST is associated with a positive drift in the post-announcement period. Our findings are consistent with sleep-deprived investors mispricing and subsequently revisiting relevant information. Overall, our results highlight the importance of investors’ cognitive ability for efficient market pricing.

Excitation characterization of whistler waves and electrostatic oscillation in asymmetric magnetic reconnection

Utilizing the 2.5D Particle-in-Cell (PIC) method, we observe that large-amplitude whistler waves are present near the separatrix on the magnetospheric side and in the outflow region during asymmetric magnetic reconnection. Minimum variance analyses confirm their quasi-parallel and anti-parallel propagation to the background magnetic field, respectively, and their accuracy is validated through parallel Poynting fluxes (S∥). The excited whistler waves have intermittent property due to the evolution and movement of the reconnection layer. Wave-Particle Interaction Analysis (WPIA) reveals a pronounced energy conversion between the waves and electrons. Our simulation results demonstrate that whistler waves near the separatrix are excited by the cyclotron resonance duo to the instability of electron beam by analyzing the electron velocity distribution functions (VDFs). Meanwhile, the electrostatic oscillation is generated by the positive parallel drift of electron beam. However, the whistler waves in the outflow region are excited by the Landau resonance duo to anisotropic instability distributions of electron beam-mode.

Deaeration of incubation buffer to minimize electrochemical impedance spectroscopy signal drift on screen-printed gold electrodes and its use for label-free detection of vancomycin

Disposable screen-printed gold electrodes (SPAuEs) are used for the development of numerous immunosensors owing to their ease of modification with biorecognition molecules. A major limitation in the development of SPAuEs based biosensors is the single-use of the electrodes leading to higher costs for sensor development, whereas multiple measurements can affect the sensor stability and reproducibility. Especially, label-free electrochemical impedance spectroscopy (EIS) based SPAuEs sensors are prone to signal drift resulting in false-positive or false-negative data questioning the reliability of the assay. We found that repeated EIS measurements on SPAuEs in ferri- and ferrocyanide solution yielded a significant increase in resistance to charge transfer (Rct) value (positive signal drift) even in a control solution (without the target analyte). The positive signal drift follows the typical pattern of a concentration-dependent calibration curve, rendering repeated measurement error-prone for sensing purposes. In this study, it is shown that the incubation of the SPAuEs in nitrogen purged deaerated phosphate buffered saline (N-PBS) minimized this signal drift in repeated/multiple EIS measurements. This method was then used to develop a peptide-based EIS biosensor for the detection of Vancomycin, a last-line antibiotic used for the treatment of severe multidrug-resistant bacterial infection. This protocol can be followed for the biosensing of other clinically important biomarkers.

Features of the Dynamic Spectrum of Signals Generated by a Wide-Aperture Electron Beam in a Large-Scale Magnetized Plasma

Electromagnetic signals generated by a wide-aperture electron beam in the laboratory plasma under conditions limitedly modeling the interaction between waves and particles in the near-Earth plasma have been studied at the large-scale Krot device. The spectrum of electromagnetic radiation includes whistler noise, which is presumably due to the current instability, and discrete (narrowband) signals near harmonics of the electron cyclotron and plasma frequencies. It has been shown that narrowband signals with a positive frequency drift that are observed at the injection of the electron beam are caused by nonstationary variations of the plasma density due to an additional ionization of a neutral gas by accelerated electrons. These effects should be taken into account to interpret nonconventional forms of the dynamic spectrum in various laboratory experiments simulating processes in the Earth’s ionosphere and magnetosphere.

Effect of variable axial load with different amplitude, frequency and phase on seismic behavior of RC columns: Experimental study and numerical simulation

The aim of this study is to investigate the effects of variable axial loads caused by horizontal and vertical ground motions on the seismic performance of reinforced concrete columns. First, three groups of cyclic loading tests were conducted. Further, the effects of constant axial load, axial load amplitude variation and frequency variation on the seismic performance indicators of the specimens, such as the failure mode, hysteresis curve, skeleton curve, stiffness degradation, ductility and energy dissipation, were studied. Subsequently, numerical analysis models were established using fiber finite elements, and verified their accuracies using experimental data. Finally, parametric analyses were conducted based on the verified numerical models to examine the effects of variable axial loads with different amplitudes, frequencies and phases on the columns. The results indicate that the axial load ratio of the columns changes constantly under the variable axial load, which results in readily apparent asymmetry in the hysteresis curve, ductility, and ultimate load. The hysteresis behavior of columns under variable axial load mainly depends on the axial load ratio corresponding to the positive and negative peak lateral drifts of each cycle. An equivalent axial load ratio method is proposed to determine the hysteresis model of columns under variable axial loads accurately.

Sorting of persistent morphological polymorphisms links paleobiological pattern to population process

AbstractBiological variation fuels evolutionary change. Across longer timescales, however, polymorphisms at both the genomic and phenotypic levels often persist longer than would be expected under standard population genetic models such as positive selection or genetic drift. Explaining the maintenance of this variation within populations across long time spans via balancing selection has been a major triumph of theoretical population genetics and ecology. Although persistent polymorphisms can often be traced in fossil lineages over long periods through the rock record, paleobiology has had little to say about either the long-term maintenance of phenotypic variation or its macroevolutionary consequences. I explore the dynamics that occur when persistent polymorphisms maintained over long lineage durations are filtered into descendant lineages during periods of demographic upheaval that occur at speciation. I evaluate these patterns in two lineages: Ectocion, a genus of Eocene mammals, and botryocrinids, a Mississippian cladid crinoid family. Following origination, descendants are less variable than their ancestors. The patterns by which ancestral variation is sorted cannot be distinguished from drift. Maintained and accumulated polymorphisms in highly variable ancestral lineages such as Barycrinus rhombiferus Owen and Shumard, 1852 may fuel radiations as character states are sorted into multiple descendant lineages. Interrogating the conditions under which trans-specific polymorphism is either maintained or lost during periods of demographic and ecological upheaval can explain how population-level processes contribute to the emergent macroevolutionary dynamics that shape the history of life as preserved in the fossil record.

On the Kolmogorov Distance for the Maximum Likelihood Estimator in the Explosive Ornstein-Uhlenbeck Process

The paper estimates the Kolmogorov distance between the distribution of the normalized maximum likelihood estimator of the positive drift parameter in the nonergodic Ornstein-Uhlenbeck process and the standard Cauchy distribution and shows exponential error rate for large time limit.

Transition from retrograde to prograde drift instabilities in a magnetron microdischarge

Rotating plasma structures, or “spokes,” in magnetized discharges characterized by perpendicular electric and magnetic fields have been seen in a growing number of studies and are believed to be the result of gradient-driven drift instabilities. Under certain conditions, we have shown [Ito and Cappelli, Appl. Phys. Lett. 94, 211501 (2009)] the spoke’s rotation to be opposite to the E × B direction, i.e., retrograde in its expected direction. Recently [Marcovati et al., J. Appl. Phys. 127, 223301 (2020)], we have linked such counter-intuitive rotation to a local inversion of the electric field. Here, we give further experimental evidence for this inversion and attempt to provide an explanation for a relatively distinct transition seen between retrograde and positive (prograde) drift. In the experiments, a partially magnetized plasma forms inside a magnetron device of ≈10 mm radius operated with argon. Discharge current–voltage measurements are acquired for a range of argon fill pressure and inter-electrode spacing. We find two branches of operation—a low current branch of negative resistance, coinciding with the retrograde spoke rotation, and a higher current branch of positive resistance, coincident with prograde spoke rotation. We postulate that at low discharge currents, high magnetic field confinement leads to a large density gradient, causing more electron transport to the anode than that demanded by the external circuit. At higher currents, anomalous axial electron transport (across the magnetic field lines) becomes dominant, eliminating the conditions for field inversion. The current thresholds for the field inversion are found to be sensitive to the argon pressure and inter-electrode spacing.