Temporal Phases Research Articles

Polarization anomaly in high harmonics in the crossover region between perturbative and extreme nonlinearity in GaAs

We investigate the characteristics of high harmonics (HHs) unique to the nonperturbative nonlinear regime. We show that the polarization state of HHs generated from GaAs changes drastically across the crossover from the weak-field perturbative regime to the strong-field extreme nonlinear regime, while the linearly polarized infrared excitation field $({E}_{\mathrm{exc}})$ is fixed to a particular crystal direction. The dependence on the ${E}_{\mathrm{exc}}$-field strength reveals that multiple emission processes with different nonlinear orders and temporal phases contribute to each order HH, and the interference among them plays a pivotal role. This interference manifests itself as a unique phenomenon: a large HH ellipticity emerges in the course of crossover, despite the fact that GaAs hosts no magnetization or linear birefringence. These results demonstrate that not only the material's symmetry but also the ultrafast nonlinear dynamics largely affects the HH polarization, and hence, HH polarization and its ${E}_{\mathrm{exc}}$-field dependence provide a useful experimental tool to probe ultrafast coherent dynamics in light-driven solid-state materials.

A hybrid job center. Composite client experiences with employment services between enforcement and care

ABSTRACT The present study introduces the concept of forms of hybridity as a tool to analyse welfare claimants’ composite experiences with public employment services. In such experiences, the job centre is depicted both as an enforcing and a caring institution. The present study demonstrates the usefulness of this conceptual tool by analysing qualitative interviews with Danish social assistance recipients. It shows how the employment system assumes several hybrid forms from the perspective of welfare claimants. The first, the actor − based hybrid form consists of numerous actors where care and enforcement stem from those who participate in the processing of cases. Second, the system/actor-based hybrid form, makes a distinction between an enforcing system and its more caring employees. In the third, a phase-based hybrid form, the participants differentiate between temporal phases of enforcement and phases of care. Our explication of hybrid forms complements the literature by providing a novel means to understand the lived experience of welfare recipients and adds nuance to discussions of social work in activation settings as either enforcing or caring.

Effects of competition reduction on intra-annual radial growth of European beech (Fagus sylvatica L.) at stem base and crown base

Key messageIn beech stands, thinning affects growth differently along tree stems, with higher and longer duration increment at stem base than at crown base while unmanaged stands depict opposite patterns.Forest management affects individual tree growth dynamics at different levels of the tree bole. Here, we assessed stem-growth patterns as a function of bole height (stem base and crown base) and competition reduction using high-resolution dendrometer records. We measured radial increments throughout the vegetation periods of 2015 and 2016 in two differently managed European beech (Fagus sylvatica L.) stands in central Germany. In one stand, trees had been repeatedly released from competition while the other had remained unmanaged for about 40 years. To assess different temporal phases of diameter increment, we fitted Weibull growth curves to dendrometer data. Stem basal area and crown base area increments of trees in the managed stand were always higher than in the unmanaged stand. In the managed stand, crown base and stem base monthly diameter increments were highly correlated until July when diameter increment at stem base surpassed the diameter increment at crown base. Conversely, in the unmanaged stand, monthly diameter increment at the stem base was often lower than at crown base. In both stands, diameter growth started earlier at crown base than at stem base. However, stem base growth in the managed stand began earlier and lasted longer than in the unmanaged stand. Our results confirm that competition reduction affects diameter increment along the stem differently than in unmanaged stands and increases growth duration. Future research is needed to test whether different growth patterns and tapers of residual trees in managed and unmanaged stands have implications for biomass and carbon storage modeling.

Coupled waveform patterns in the arterial and venous fontan circulation are related to parameters of pulmonary, lymphatic and cardiac function

The lack of a sub-pulmonary ventricle in patients with a Fontan circulation contributes to circulatory decline, largely related to increased central venous pressure. Our group has determined that single-site waveform analysis correlates with clinical features of Fontan patients. The goal of this study was to determine if multi-site waveform analysis yielded additional associations with functional status or cardiac performance. Patients with a Fontan circulation (N = 95) that underwent free-breathing cardiac MRI were included in this study. Volumetric flow rate curves were sampled in the ascending aorta, superior vena cava, inferior vena cava and left pulmonary artery. Flow curves were interpolated to equal temporal phases and were then used to create three data matrices of arterial and venous waveforms. Principal component analysis was performed on each matrix and principal components that accounted for >10% variance were correlated to traditional clinical indices. Results indicate correlation of inferior and superior vena cava waveform patterns to parameters of pulmonary (RV/TLC %, lowest SaO2%), lymphatic (cystatin-c, BUN, alkaline phosphatase) and to ventricular function (CI, EF, EDVi, ESVi and VVCR). This study demonstrates that coupled waveform analysis of arterial and venous vessels relays additional information about Fontan patient status.

Bubble dynamics and atomization in evaporating polymeric droplets

We investigate the interaction of an aqueous polymeric droplet with a tuneable continuous laser in an acoustically levitated environment. The effect of laser irradiation intensity and polymeric concentration on various spatio-temporal parameters is unearthed using high-speed shadowgraphy and theoretical scaling analysis. We observe four temporal phases: droplet evaporation, vapour bubble growth followed by membrane inflation, bubble/membrane rupture through hole nucleation and droplet breakup. During the initial droplet evaporation phase, concentration build-up at the droplet surface beyond a critical limit leads to the formation of a skin layer. It is revealed that, at a given location inside the droplet, hot spots occur, and the maximum temperature at the hot spots scales linearly with irradiation intensity until a bubble nucleates. The low-intensity laser interaction leads to symmetric membrane inflation that eventually forms holes at droplet poles and cracks on the shell surface. On the contrary, high intensity causes early bubble nucleation followed by asymmetric membrane inflation that eventually ruptures through multiple hole formation. Furthermore, the growth and rupture of the membrane is followed by a catastrophic breakup of the droplet. Two dominant atomization modes are reported at significantly high irradiation intensities: stable sheet collapse and unstable sheet breakup. The evolution of droplets into a stable/unstable sheet follows universally observed ligament and hole dynamics. A regime map is shown to describe the influence of polymer concentration and irradiation intensity on the strength and mode of droplet atomization.

Multivariate Statistical Analysis of Hydrochemical and Microbiological Natural Tracers as a Tool for Understanding Karst Hydrodynamics (The Unica Springs, SW Slovenia)

AbstractVarious multivariate statistical techniques (MST) can provide valuable insights into water quality variability. Despite numerous studies in which these methods have been used, their potential has not been fully exploited. This paper presents an improved approach to better understand the hydrodynamics of karst systems. The integrated application of hierarchical cluster and principal component analysis in combination with factor analysis allowed the construction of an advanced multivariate chemograph. The analytical procedure was applied in a binary karst aquifer known for its complex hydrodynamics and mixing of water with similar hydrochemical composition. In addition, the study area provides access to an integral groundwater flow system (ponor‐cave‐spring) and offers extensive prior hydrogeological knowledge. The approach allowed reduction and discrimination of the main parameters affecting water quality characteristics. Their identification enabled recognition of three predominant recharge components: (a) stored water impact with Cl and electrical conductivity, (b) sinking stream impact with turbidity and bacteria composition and (c) karst aquifer impact with Ca/Mg ratio as principal parameters. The results supported innovative characterization of the dominant processes and isolation of temporal hydrodynamic phases of individual monitoring points within the aquifer system. On this basis, a spatio‐temporal conceptual model was developed and the hydrodynamic behavior of the main springs was revealed. The applied methodology demonstrated to be useful in ascertaining functioning of a complex karst system under flood event conditions.

Activation of p53 and FOXO Transcription Tactors in Response to Oxidative Stress Occurs in Distinct Temporal Phases

Activation of p53 and FOXO Transcription Tactors in Response to Oxidative Stress Occurs in Distinct Temporal Phases

The Formation of Shapes: Interplay of Genes during Leaf Development Processes

Leaf shape, as one of the clearest manifestations of plant morphology, shows considerable variation owing to genetics and the environment. Leaf initiation occurs in the peripheral zone of the SAM and goes through the three overlapping phases of leaf primordium initiation, leaf dorsiventral development, and leaf marginal meristem establishment. Transcription factors, such as KNOX, WOX, and CUC; hormone-regulating genes, such as GA2ox, GA20ox, and PIN1; and miRNAs such as miR164/165 are tightly involved in leaf shaping through the generation of intricate cooperative networks in different temporal phases and specific tissue zones. Here, we briefly discuss the critical interplay occurring between certain genes and the pivotal role these play in the leaf developmental network and phytohormone regulation, including AS1/AS2–KNOX–GA20ox–GA, miR164–NAM/CUC–PIN1–auxin, and CUC–BAS1/CYP734A–BR, and we attempt to summarize several basic insights into the mechanisms of leaf shape regulation.

Laparoscopic Cholecystectomy in the Time of Coronavirus: A Level-1 Trauma Center's Experience.

Laparoscopic cholecystectomy (LC), one of the most common surgical procedures performed in the U.S., offers a window into the effects of the COVID-19 pandemic on routine surgical care. The purpose of our study was to analyze the effects of the COVID-19 pandemic at a Level-1 trauma center on the performance rate of non-elective LC over time. A retrospective chart review from July 2019 to December 2020 identified all non-elective LC cases performed at a level-1 trauma center. Patients were categorized into 4 temporal phases along the course of the pandemic based on statewide incidence data on COVID-19: pre-pandemic, peak 1, recovery, and peak 2. We compared the phases based on demographic information and outcomes. In total, 176 patients were reviewed. The performance rate in cases/day varied as follows: pre-pandemic .61, 1st peak .34, recovery .44, and 2nd peak .53. The complication rate was highest in the 2nd peak (16%) (P < .05). Compared to the pre-pandemic period, the intra-pandemic period had a higher incidence of complicated gallbladder disease (P < .05). In the non-elderly subgroup, complicated gallbladder disease was significantly more prevalent in the intra-pandemic period compared to the pre-pandemic period (25% vs 10%, P < .05). Our data suggests a learning curve throughout the course of the pandemic, reflecting a stepwise increase in the performance rate of LC. The higher incidence of complicated gallbladder disease in the intra-pandemic period may imply patient hesitancy to seek routine surgical care, especially among younger patients.

Systemic Approach to Universal Design of Urban Spaces - Case Study of Trbovlje, Slovenia.

The study consisted of examining universal design principles and applying selected interventions with the goal of solving accessibility issues in the settlement of Trbovlje. As a result of the investigative process and the layered spatial data concerning universal design theory, it was possible to propose the dynamics for the implementation of the design solutions. Deliberate selection of only specific universal design features as a pragmatic decision is what ensures the proposed solution's real-world application value. Subdividing a wholistic design into temporal phases secures a more feasible and pragmatic approach to reach the end goal while still preserving the full functionality of each individual phase immediately and thus its effectiveness. Such a systemic approach is proposed as a way of creating a more focused overview of the settlement, making a better design for the solution of specific issues, assessing these solutions, and implementing them in selected places. This approach and thinking present itself as a good method of granting universal accessibility that could be adopted as a mandatory part of any urban plan.

Change Detection over mining areas using Deep Neural Networks from Planetscope image time series

The processes of change detection (CD) in land use and land cover through satellite images acquired in different temporal phases represent a key process to monitor the land, the environment and evaluate disasters. Currently the methodologies used for CD based on pixels do not allow processing a large amount of images massively, so it is not possible to analyze all the available information. Main aim of this research is to evaluate the performance of Deep learning methods for CD, grouped in two approaches, across open mining areas from PlanetScope (PS) image time series of the Cerrejon mine in Colombia. Two approaches for change generation are proposed, one based on post-classification comparison in which two convolutional neural network (CNN) architectures are evaluated: U-Net and Feature Pyramidal Network (FPN) for the classification of mining areas along the time series, for this purpose different models with different hyperparameters were generated and trained to select the most suitable for such process and subsequently perform the difference between the periods of the series; and a second approach based on direct change detection in which a modified U-Net network was evaluated from pairs of images. For this purpose, different models were also trained selecting the most appropriate for the detection of changes for each period of the time series, obtaining a map of changes for each approach, each one the results were validated; the most appropriate approach was number 2 (Direct change detection), with kappa accuracies greater than 0.9 in each period of the time series.

The Variation in the Diastolic Period with Interventricular Septal Displacement and Its Relation to the Right Ventricular Function in Pulmonary Hypertension: A Preliminary Cardiac Magnetic Resonance Study.

Background: Pulmonary hypertension (PH) is known to alter the biventricular shape and temporal phases of the cardiac cycle. The presence of interventricular septal (IVS) displacement has been associated with the severity of PH. There has been limited cardiac magnetic resonance (CMR) data regarding the temporal parameters of the cardiac cycle in PH. This study aimed to quantify the temporal changes in the cardiac cycle derived from CMR in PH patients with and without IVS displacement and sought to understand the mechanism of cardiac dysfunction in the cardiac cycle. Methods: Patients with PH who had CMR and right heart catheterization (RHC) examinations were included retrospectively. Patients were divided into an IVS non-displacement (IVSND) group and an IVS displacement (IVSD) group according to IVS morphology, as observed on short-axis cine CMR images. Additionally, age-matched healthy volunteers were included as the health control (HC). Temporal parameters, IVS displacement, ventricular volume and functional parameters were obtained by CMR, and pulmonary hemodynamics were obtained by RHC. The risk stratification of the PH patients was also graded according to the guidelines. Results: A total of 70 subjects were included, consisting of 33 IVSD patients, 15 IVSND patients, and 22 HC patients. In the IVSND group, only the right ventricle ejection fraction (RVEF) was decreased in the ventricular function, and no temporal change in the cardiac cycle was found. A prolonged isovolumetric relaxation time (IRT) and shortened filling time (FT) in both ventricles, along with biventricular dysfunction, were detected in the IVSD group (p < 0.001). The IRT of the right ventricle (IRTRV) and FT of the right ventricle (FTRV) in the PH patients were associated with pulmonary vascular resistance, right cardiac index, and IVS curvature, and the IRTRV was also associated with the RVEF in a multivariate regression analysis. A total of 90% of the PH patients in the IVSD group were stratified into intermediate- and high-risk categories, and they showed a prolonged IRTRV and a shortened FTRV. The IRTRV was also the predictor of the major cardiovascular events. Conclusions: The temporal changes in the cardiac cycle were related to IVS displacement and mainly impacted the diastolic period of the two ventricles in the PH patients. The IRT and FT changes may provide useful pathophysiological information on the progression of PH.

Uncovering temporospatial sensitive TBI targeting strategies via in vivo phage display.

The heterogeneous pathophysiology of traumatic brain injury (TBI) is a barrier to advancing diagnostics and therapeutics, including targeted drug delivery. We used a unique discovery pipeline to identify novel targeting motifs that recognize specific temporal phases of TBI pathology. This pipeline combined in vivo biopanning with domain antibody (dAb) phage display, next-generation sequencing analysis, and peptide synthesis. We identified targeting motifs based on the complementarity-determining region 3 structure of dAbs for acute (1 day post-injury) and subacute (7 days post-injury) post-injury time points in a preclinical TBI model (controlled cortical impact). Bioreactivity and temporal sensitivity of the targeting motifs were validated via immunohistochemistry. Immunoprecipitation–mass spectrometry indicated that the acute TBI targeting motif recognized targets associated with metabolic and mitochondrial dysfunction, whereas the subacute TBI motif was largely associated with neurodegenerative processes. This pipeline successfully discovered temporally specific TBI targeting motif/epitope pairs that will serve as the foundation for the next-generation targeted TBI therapeutics and diagnostics.

The Interplay between Spatial Urban Expansion and Morphologic Landscapes East of Cairo, Egypt Using Time Series Satellite Imagery

This study aims to monitor the magnitudes, rates, and directions of spatial urban expansions east of Cairo and their interactions with the initial morphologic landscapes. The approach relies on using CORONA satellite images acquired in 1969 with fine spatial resolution and time series images of Landsat and ASTER from 1984 to 2020. The CORONA images enable retrieval of the initial morphologic components, whereas the Landsat and ASTER images enable the spatial urban expansions to be mapped. The magnitudes of spatial urban expansions have been massive, in the order of 165 km2. These expansions have occurred through four main temporal phases with different spatial extents, rates, and directions in response to common urban policies and socioeconomic settings. Assessing the interactions between urban expansions and the morphology of watersheds in the study area indicates that the directions of urban expansion have been opposite to the geospatial orientations of the watersheds. In addition, significant urban areas in the order of ~8 km2 are under the direct threat of flash floods because they are misplaced within the valley floors of the studied watersheds. The study concludes that successful spatial urban expansion should consider the morphologic characteristics of the initial landscape for the purpose of maximizing interests and avoiding or reducing potential hazards against urban settlements.

Evolution of the cavity in a particle dispersion triggered by laser-induced breakdown

Focusing a laser beam to a spot within a particle-laden air flow can cause laser-induced breakdown, which generates a spherically expanding shockwave and ensuing hot gas vortex (HGV). This can cause an initially uniform spatial distribution of static particles to be scattered non-homogeneously, creating a particle void region (or cavity). High-speed schlieren imaging has been applied to investigate the propagation of this shockwave and deformation of the HGV. Evolution of the particle distribution has been captured by a high-speed camera. It has been found that the cavity evolves over three temporal phases: expansion, distortion, and separation. The cavity is first created as the shockwave expels the particles in the radial direction. Next, the cavity is distorted by the HGV and then separates into smaller cavities before finally disappearing due to mixing from the HGV. The temporal and spatial characteristics of the cavity and the mechanism by which it changes in each phase are discussed. Experiments were conducted at three different breakdown energies of 15, 49, and 103 mJ. Propagation speed of the shockwave and the size and strength of the HGV are found to be the main factors controlling this phenomenon.

The Discovery of Aspect: A Heuristic Parallel Corpus Study of Ingressive, Continuative and Resumptive Viewpoint Aspect

Languages differ in how systematically and obligatorily they encode conceptual categories such as tense and aspect. By drawing on large parallel corpora, these differences can be exploited heuristically: expressive obligatoriness and the systematicity of a conceptual category in one language can function as a probe for other languages that do not (evidently) encode it. This study applies this method—called heuristic translation mining (HTM)—to viewpoint aspect in Mandarin (an aspect-oriented language) and Dutch (a non-aspect-oriented language). Specifically, it takes the Mandarin aspect markers 起来-qilai (“ingressive”) and 下去-xiaqu (“continuative”) and collects translation strategies for these markers from a corpus of five Mandarin novels and their Dutch translations. The outcomes are methodological, descriptive and theoretical in nature. Methodologically, it is shown how conceptual templates consisting of temporal boundaries and phases facilitate annotating specific types of viewpoint aspect consistently. Descriptively, the exercise indicates at which linguistic levels viewpoint aspect may be encoded in a non-aspect-oriented language. Theoretically, conducting an HTM analysis with several aspect markers at once makes it possible to quantify (non-)marking of conceptual content; it turns out that the types of viewpoint under study correspond to varying marking frequencies, which may correlate with conceptual complexity.

HEARTBEAT4D: An Open-source Toolbox for Turning 4D Cardiac CT into VR/AR.

Four-dimensional data sets are increasingly common in MRI and CT. While clinical visualization often focuses on individual temporal phases capturing the tissue(s) of interest, it may be possible to gain additional insight through exploring animated 3D reconstructions of physiological motion made possible by augmented or virtual reality representations of 4D patient imaging. Cardiac CT acquisitions can provide sufficient spatial resolution and temporal data to support advanced visualization, however, there are no open-source tools readily available to facilitate the transformation from raw medical images to dynamic and interactive augmented or virtual reality representations. To address this gap, we developed a workflow using free and open-source tools to process 4D cardiac CT imaging starting from raw DICOM data and ending with dynamic AR representations viewable on a phone, tablet, or computer. In addition to assembling the workflow using existing platforms (3D Slicer and Unity), we also contribute two new features: 1. custom software which can propagate a segmentation created for one cardiac phase to all others and export to surface files in a fully automated fashion, and 2. a user interface and linked code for the animation and interactive review of the surfaces in augmented reality. Validation of the surface-based areas demonstrated excellent correlation with radiologists' image-based areas (R > 0.99). While our tools were developed specifically for 4D cardiac CT, the open framework will allow it to serve as a blueprint for similar applications applied to 4D imaging of other tissues and using other modalities. We anticipate this and related workflows will be useful both clinically and for educational purposes.

The legacy of 1300 years of land use in Jamaica

Despite decades of archaeological research on Jamaica, little is known about how settlers influenced landscape change on the island over time. Here, we examine the impact of human occupation through a multi-proxy approach using phytolith, charcoal, and stratigraphic analyses. White Marl was a continuously inhabited village settlement (ca. 1050–450 cal yrs BP) with large mounded midden areas, precolonial house structures, and human landscape management practices. We have shown that the local vegetation at White Marl was directly affected by human settlement through the use of agroforestry and burning, and suggest that fire was used to modify vegetation. Manioc phytoliths were found throughout human occupation and are broadly associated with increases in evidence for burning, suggesting fire was used to modify the landscape and clear vegetation for crop cultivation. The phytolith assemblages relate to three distinct temporal vegetation phases: (1) the earliest occupation dominated by arboreal vegetation (pre-ca. 870 cal yrs BP); (2) a transition to palm-dominated vegetation (ca. 870–670 cal yrs BP); and (3) the latest occupation representing European colonization associated with a more open, grass-dominated landscape (after ca. 670 cal yrs BP). These transitions occur independent of changes in paleoclimate records, suggesting humans were the dominant driver of vegetation change.

The Need for Eccentric Speed: A Narrative Review of the Effects of Accelerated Eccentric Actions During Resistance-Based Training.

Eccentric training as a method to enhance athletic performance is a topic of increasing interest to both practitioners and researchers. However, data regarding the effects of performing the eccentric actions of an exercise at increased velocities are limited. This narrative review aimed to provide greater clarity for eccentric methods and classification with regard to temporal phases of exercises. Between March and April 2021, we used key terms to search the PubMed, SPORTDiscus, and Google Scholar databases within the years 1950-2021. Search terms included 'fast eccentric', 'fast velocity eccentric', 'dynamic eccentric', 'accentuated eccentric loading', and 'isokinetic eccentric', analysing both the acute and the chronic effects of accelerated eccentric training in human participants. Review of the 26 studies that met the inclusion criteria identified that completing eccentric tempos of < 2s increased subsequent concentric one repetition maximum performance, velocity, and power compared with > 4s tempos. Tempos of > 4s duration increased time under tension (TUT), whereas reduced tempos allowed for greater volume to be completed. Greater TUT led to larger accumulation of blood lactate, growth hormone, and testosterone when volume was matched to that of the reduced tempos. Overall, evidence supports eccentric actions of < 2s duration to improve subsequent concentric performance. There is no clear difference between using eccentric tempos of 2-6s if the aim is to increase hypertrophic response and strength. Future research should analyse the performance of eccentric actions at greater velocities or reduced time durations to determine more factors such as strength response. Tempo studies should aim to complete the same TUT for protocols to determine measures for hypertrophic response.

Extended criteria donors for robotic right hepatectomy: A propensity score matched analysis.

Robotic right donor hepatectomy (RDH) has been reported from experienced centers with reduced morbidity when compared to open RDH. However, outcomes in donors with large grafts/complex biliovascular anatomy are unknown. Out of 170 robotic RDH, 100 had one or more of the following: graft weight ≥800 g, type 2/3 portal vein, >1 bile duct or hepatic artery and inferior hepatic veins >5 mm requiring reconstruction (extended criteria donors [ExRDH]), while the remaining 70 had standard anatomy (SRDH). After propensity score matching, 66 ExRDH were compared with 66 SRDH. Additionally, all robotic RDH performed were analyzed in three temporal phases (60, 60, and 50). Peak AST and ALT were higher amongst donors and recipients in the ExRDH arm compared to SRDH. Other intraoperative parameters and postoperative complications were similar between the two groups. During the last phase, donors demonstrated reduction in duration of surgery, postoperative complications, and hospital stay while recipients showed decreased blood loss and hospital stay. Robotic right hepatectomy performed in donors with extended criteria have similar perioperative outcomes as standard donors. However, a significant learning curve needs to be traversed. Further studies are required before safely recommending robotic RDH for all donors.