Types Of Trajectories Research Articles

Exploring social inequalities in healthcare trajectories following diagnosis of diabetes: a state sequence analysis of linked survey and administrative data

BackgroundSocial inequalities in complications associated with diabetes mellitus persist. As a primary care sensitive condition (PCSC), this association could be related to differential access to primary care. Our objectives are to establish a typology of care trajectories following a new diagnosis, and to explore social determinants of trajectories.MethodsWe used the TorSaDe (The Care Trajectories-Enriched Data) cohort, which links Canadian Community Health Survey respondents to health administrative data. Care trajectories were mapped over a two-year period following a new diagnosis and analysed using state sequence and clustering methods. Associations between individual and geographic characteristics with trajectory types were assessed with multinomial logistic regression.ResultsThree trajectories were identified: Regular Family Physician (FP) Predominant, Specialist Physician Predominant, and Few Services. With Regular FP as the reference, males had higher odds of experiencing the Few Services trajectory, higher education was associated with higher odds of both the Few Services and the Specialist trajectories, and immigrants had higher odds of the Specialist trajectory. Diagnoses in a physician’s office, as opposed to in hospital, were associated with higher odds of the Regular FP trajectory.ConclusionsThe Regular FP trajectory most closely aligns with the management principles of the PCSC approach. We did not find strong evidence of social status privileging access to this trajectory. However, the association with location of diagnosis suggests that efforts to ensure patients diagnosed in hospital are well linked to a regular family physician for follow up may help to reduce unnecessary specialist use and meet PCSC goals.

Internalized stigma and self-presentation strategies of persons with psychotic and psychiatric experiences.

Stigma is detrimental to persons experiencing mental distress, as it impacts on their social inclusion, quality of life, and recovery. In this article, we present the self-presentation strategies employed by persons with psychosis to manage internalized stigma. A study of the life trajectories of persons with psychosis analyzed 27 biographical interviews and identified five types of biographical trajectories. This article focuses on one biographical type, represented by six narratives. Participants placed in this biographical type struggle to portray a socially acceptable self through concealing experiences of distress and distancing the self from the psychiatric label they entail. This was achieved through several strategies, including the normalization of prior life, unwillingness to disclose psychotic experiences, unquestioning compliance with psychiatric medication, and presenting oneself as an ordinary person. Fostering more adaptive coping strategies to reduce internalized stigma may be a potential goal for psychosocial interventions.

Differentiating phonological delay from phonological disorder: Executive function performance in preschoolers.

The conversational speech of most children can be understood by people outside the family by the time they reach 4years. However, for some children, speech sound disorders (SSDs) persist into their early school years, and beyond, despite adequate hearing, oromotor function, and language learning opportunities. One explanation for children's SSDs are domain-general cognitive-linguistic deficits that impair the child's ability to correctly derive rules governing how speech sounds legally combine to form words in a specific language. To explore whether there are differences in performance on executive function tasks between children who make speech errors characteristic of phonological delay and those who make speech errors characteristic of phonological disorder. Twenty-six children aged from 3;6 to 5;2 (13 with phonological delay and 13 with phonological disorder), matched pairwise for age and sex (nine males), were assessed on tasks measuring cognitive flexibility (rule abstraction and cognitive shift) and phonological working memory. For the cognitive flexibility tasks, the performance of children with phonological delay was significantly better than that for children with phonological disorder, but there were no group differences for the phonological working memory task. Children with phonological disorders might benefit from intervention programmes that incorporate training in cognitive flexibility. Children with phonological delay and phonological disorder comprise the two largest SSD subgroups that present to speech-language therapy clinics. Evidence suggests domain-general cognitive processes (e.g., phonological working memory, ability to revise faulty underlying representations, rule abstraction, and cognitive shift) influence phonological development. Differences between the two subgroups in the types of speech errors, linguistic abilities, developmental trajectories, and responses to intervention have been reported, yet little is known about the underlying cognitive-linguistic deficits. The results of this study suggest that children with phonological delay and phonological disorder have distinct patterns of performance on executive function tasks: Children with phonological disorder showed deficits in domain general rule-abstraction and cognitive shift when compared to children with phonological delay. WHAT ARE THE POTENTIAL OR ACTUAL CLINICAL IMPLICATIONS OF THIS WORK?: The findings draw attention to: (1) the importance of differential diagnosis of phonological delay and phonological disorder; (2) the role of domain-general cognitive processes in explaining why children make particular types of errors; and (3) the need to develop innovative and tailored intervention techniques that target specific underlying deficits.

Machine learning classification of trajectories from molecular dynamics simulations of chromosome segregation.

In contrast to the well characterized mitotic machinery in eukaryotes it seems as if there is no universal mechanism organizing chromosome segregation in all bacteria. Apparently, some bacteria even use combinations of different segregation mechanisms such as protein machines or rely on physical forces. The identification of the relevant mechanisms is a difficult task. Here, we introduce a new machine learning approach to this problem. It is based on the analysis of trajectories of individual loci in the course of chromosomal segregation obtained by fluorescence microscopy. While machine learning approaches have already been applied successfully to trajectory classification in other areas, so far it has not been possible to use them to discriminate segregation mechanisms in bacteria. A main obstacle for this is the large number of trajectories required to train machine learning algorithms that we overcome here by using trajectories obtained from molecular dynamics simulations. We used these trajectories to train four different machine learning algorithms, two linear models and two tree-based classifiers, to discriminate segregation mechanisms and possible combinations of them. The classification was performed once using the complete trajectories as high-dimensional input vectors as well as on a set of features which were used to transform the trajectories into low-dimensional input vectors for the classifiers. Finally, we tested our classifiers on shorter trajectories with duration times comparable (or even shorter) than typical experimental trajectories and on trajectories measured with varying temporal resolutions. Our results demonstrate that machine learning algorithms are indeed capable of discriminating different segregation mechanisms in bacteria and to even resolve combinations of the mechanisms on rather short time scales.

Employment Trajectories Across the Life Course and Oral Health Among Older Persons in a Developing Country.

A significant research gap on socioeconomic determinants of oral health among older persons is that socioeconomic indicators, like employment status, have essentially been problematized and measured using a cross-sectional approach. Based on a life course approach, and using data from a population-representative, face-to-face and longitudinal-retrospective survey focused on older people in Chile (N = 802), we reconstructed representative types of individual employment trajectories and measured their association with different oral health indicators in old age. Our results show that employment trajectories characterized by continuous, formal, full-time employment have a protective effect for multiple oral health indicators among older people. Our study demonstrates the need for public policies on oral health in old age to incorporate a life course approach and to consider the negative impact of constantly working in informal employment or being out of the labor market permanently, particularly in countries like Chile where temporary and informal employment has risen steadily.

Gendered and Stratified Family Formation Trajectories in the Context of Latin American Migration, 1950 to 2000

The interdependence of migration and family formation has been studied extensively, but studies that consider the embeddedness of this interdependence within gender and class relations are less common. Most existing research on family and migration treats gender and social class as separate determinants of family events or transitions, instead of analyzing how the intersections of both shape full family formation trajectories, defined as all partnership and childbearing statuses throughout an individual life course. We overcome this gap by using an intersectionality framework to analyze trajectories of family formation and migration collected by the Mexican and Latin American Migration projects (1982–2016). Using retrospective information, we reconstruct full family formation and dissolution trajectories (i.e., individuals’ marital statuses and number of children born from ages 15 to 39) for 16,000 individuals and apply sequence and cluster analysis to define a six-category typology of ideal family formation trajectories. Next, we associate this typology with individuals’ sex, age at migration (domestic, international), and educational attainment as a way to measure individuals’ social class position. Our results suggest that the relationship between migration and typical family trajectories depends on the intersection of individuals’ social class and gender. Previous studies have neglected this intersection by overly focusing on the “average” migrant's experience. Migration research must acknowledge and account for migrants’ heterogenous experiences and pay more attention to how intersecting social categories mediate the relationship between migration and other demographic processes.

A Systematic Literature Review of Health Utility Values in Breast Cancer

BackgroundHealth utility values (HUVs) are important inputs to the cost-utility analysis of breast cancer interventions.PurposeProvide a catalog of breast cancer–related published HUVs across different stages of breast cancer and treatment interventions.Data SourcesSystematic searches of MEDLINE, MEDLINE In-Process, EMBASE, Web of Science, CINAHL, PsycINFO, EconLit, and Cochrane databases (2005–2017).Study SelectionStudies published in English that reported mean or median HUVs using direct or indirect methods of utility elicitation for breast cancer.Data ExtractionIndependent reviewers extracted data on a preestablished and piloted form; disagreements were resolved through discussion.Data AnalysisMixed-effects meta-regression using restricted maximum likelihood modeling was conducted for intervention type, stage of breast cancer, and typical clinical and treatment trajectory of breast cancer patients to assess the effect of study characteristics (i.e., sample size, utility elicitation method, and respondent type) on HUVs.Data SynthesisSeventy-nine studies were included in the review. Most articles (n = 52, 66%) derived HUVs using the EQ-5D. Patients with advanced-stage breast cancer (range, 0.08 to 0.82) reported lower HUVs as compared with patients with early-stage breast cancer (range, 0.58 to 0.99). The meta-regression analysis found that undergoing chemotherapy and surgery and radiation, being diagnosed with an advanced stage of breast cancer, and recurrent cancer were associated with lower HUVs. The members of the general public reported lower HUVs as compared with patients.LimitationsThere was considerable heterogeneity in the study population, health states assessed, and utility elicitation methods.ConclusionThis review provides a catalog of published HUVs related to breast cancer. The substantial heterogeneity in the health utility studies makes it challenging for researchers to choose which HUVs to use in cost-utility analyses for breast cancer interventions.

Shoreline migration paths and depositional architecture of early–mid Miocene deltaic clinoforms in response to sea‐level changes in the north‐eastern shelf margin, South China Sea

AbstractShoreline trajectory analysis improves the understanding of the correlation between clinoform architecture, shoreline and shelf‐edge development, and sea‐level changes. This study uses cores, well‐logs and seismic data to investigate the depositional architecture and shoreline migration paths of early−mid Miocene deltaic clinoforms in the northern Pearl River Mouth basin, South China Sea. Five clinoform types are observed, including sigmoidal, oblique, tangential oblique, parallel oblique and sigmoidal‐oblique clinoforms. Both the rollovers of deltaic clinoforms in seismic sections and the transitional points between delta plain and delta front deposits in well correlation cross‐sections can be used as the indicators for shoreline positions, provided that there are no significantly extended subaqueous deltas. This allows for the identification of three shoreline trajectory types from a single clinoform set and three major stages from the net shoreline trajectory for multiple clinoform sets. A landward‐directed net shoreline trajectory and ascending shoreline trajectories dominate in Stage 1 (23.8 to 17.5 Ma) with sigmoidal clinoforms transitioning into parallel oblique clinoforms, suggesting a rise in third and fourth‐order relative sea level. Stage 2 (17.5 to 13.8 Ma) displays flat or descending trajectories and an overall seaward‐directed net trajectory with a change from parallel to tangential oblique clinoform, indicating a relative sea‐level fall. The reoccurrence of sea‐level rise in Stage 3 (13.8 to 10.5 Ma) was inferred by a landward migration of parallel oblique clinoforms. This study shows that shoreline trajectory and net shoreline trajectory plotted from both seismic and well data is consistent with the regional sea‐level curves estimated from foraminiferal fossil records and the shelf‐edge development, which can be used to estimate the third and fourth‐order relative sea‐level changes in passive margins with wide, low‐gradient shelves. Furthermore, clinoform architecture and migration may have been controlled by the variations of subsidence/uplift and sediment supply produced by tectonic events.

Trajectories of Spatial Assimilation or Place Stratification? A Typology of Residence and Workplace Histories of Newly Arrived Migrants in Sweden

In most societies, resources and opportunities are concentrated in neighborhoods and workplaces occupied by the host population. The spatial assimilation and place stratification theories propose trajectories (the sequences of events) leading to minority and migrant access to or exclusion from these advantageous places. However, most previous research on these theories did not ask whether such theorized trajectories occur. We apply sequence analysis to decade-long residence and workplace histories of newly arrived migrants in Sweden to identify a typology of combined residence-work trajectories. The seven types of trajectories in our typology are characterized by varying degrees of proximity to the host population in residential neighborhoods and workplaces and by different patterns of change in such proximity over time. The pivotal role of socioeconomic gains in spatial assimilation, posited by the namesake theory, is not supported, as we do not find that migrant employment precedes residence alongside the host population. The importance of housing-market discrimination for migrants’ exclusion from host-dominated spaces, posited by place stratification theory, is only weakly supported, as we find that migrants from less affluent countries accumulate disadvantage over time, likely due to discrimination in both the labor and housing markets. Our findings also underscore the need for new theories explaining migrant residential outcomes which apply to contexts where migrant-dense neighborhoods are still forming.

Active Model-Based Hysteresis Compensation and Tracking Control of Pneumatic Artificial Muscle.

The hysteretic nonlinearity of pneumatic artificial muscle (PAM) is the main factor that degrades its tracking accuracy. This paper proposes an efficient hysteresis compensation method based on the active modeling control (AMC). Firstly, the Bouc–Wen model is adopted as the reference model to describe the hysteresis of the PAM. Secondly, the modeling errors are introduced into the reference model, and the unscented Kalman filter is used to estimate the state of the system and the modeling errors. Finally, a hysteresis compensation strategy is designed based on AMC. The compensation performances of the nominal controller with without AMC were experimentally tested on a PAM. The experimental results show that the proposed controller is more robust when tracking different types of trajectories. In the transient, both the overshoot and oscillation can be successfully attenuated, and fast convergence is achieved. In the steady-state, the proposed controller is more robust against external disturbances and measurement noise. The proposed controller is effective and robust in hysteresis compensation, thus improving the tracking performance of the PAM.

Educational and Career Trajectories of the Russian Youth in a Longitudinal Perspective: A Case of University Graduates

Education and labor market outcomes of the Russian graduates are vastly studied, including their employment status, salaries, types of universities and majors they study. However, there is a lack of research of the graduates’ typical paths in education and labor market, whether they fit the conventional trajectory high school–university–permanent employment. Another question is how social background and human capital differentiate trajectories and predict a path, which graduate opts to. In this article, we address both questions. Employing the longitudinal panel study “Trajectories in Education and Careers” we examine the nine-year trajectories of those who earned a university diploma by the age of 25. In our research, we use sequence analysis to identify trajectories and regression analysis to estimate the probability to follow each trajectory depending on individual characteristics–socio-economic status and human capital–while controlling for demographic variables.
 We identify nine typical trajectories, including several types of a linear path, various career-oriented trajectories, a reverse and a delayed path, unstable and nontraditional trajectories. This set of education-career paths largely corresponds to foreign studies, but the Russian graduates’ trajectories turn out to be smoother. At the same time, individual factors of human capital and socio-economic status moderate education-career paths. The probability of following trajectories with prolonged education (with a post-bachelor’s degree) is significantly higher for high achieving students. Entering early career trajectories is associated with a non–cognitive skill–openness to experience. Socio-economic status differentiates two early career trajectories: "accelerated adulthood" for those with low SES and "encouraged professionalization", which is associated with high SES. Following an unstable trajectory is not associated with either socio-economic status or academic performance (cognitive skills) but is associated with low awareness about the field of study when entering a university (ill-informed choice).

Optimization design method of infill well trajectory with bypassing obstacles in the fractured area of shale gas reservoir

In the design of infill well trajectory in fractured area of shale gas reservoir, it is necessary to consider the problem how to bypass the fractured influence area of the old shale gas wells, as well as the problem of mutual interference between the different fractured sections during production. In this paper, the geometric model of the obstacles in fractured area of shale gas reservoir, which considers the trajectory error and fracturing effect, is established by vector algebra method. The trajectory type is classified according to positional relations among the obstacle, the directional line of initial point and target point. The trajectory optimization model for bypassing obstacles takes the minimum total well length as objective function, the safety distance to obstacle as one of the constraints. In addition, the geometric check method for judging whether there is interference between the different fractured sections is proposed based on the geometric obstacle model. Case studies have been carried out according to the field data from Fuling, and the results indicate that the trajectory optimization model in this paper can obtain the optimum trajectory to meet the needs for bypassing obstacle, minimum trajectory length and avoiding trial calculation. Besides, if the fracturing effect is ignored, the size of the obstacle will be significantly underestimated in fractured area of shale gas reservoir, which will result in drilling accidents. In sum, the obstacle model in this paper is more consistent with the situation of field fractured area drilling practice than that of the published model. This study will provide a more safer and briefer design method for optimizing the infill well trajectory in fractured area of shale gas reservoir, which is of great significance to the shale gas drilling design and drilling safety.

Twin Delayed Deep Deterministic Policy Gradient-Based Target Tracking for Unmanned Aerial Vehicle With Achievement Rewarding and Multistage Training

Target tracking using an unmanned aerial vehicle (UAV) is a challenging robotic problem. It requires handling a high level of nonlinearity and dynamics. Model-free control effectively handles the uncertain nature of the problem, and reinforcement learning (RL)-based approaches are a good candidate for solving this problem. In this article, the Twin Delayed Deep Deterministic Policy Gradient Algorithm (TD3), as recent and composite architecture of RL, was explored as a tracking agent for the UAV-based target tracking problem. Several improvements on the original TD3 were also performed. First, the proportional-differential controller was used to boost the exploration of the TD3 in training. Second, a novel reward formulation for the UAV-based target tracking enabled a careful combination of the various dynamic variables in the reward functions. This was accomplished by incorporating two exponential functions to limit the effect of velocity and acceleration to prevent the deformation in the policy function approximation. In addition, the concept of multistage training based on the dynamic variables was proposed as an opposing concept to one-stage combinatory training. Third, an enhancement of the rewarding function by including piecewise decomposition was used to enable more stable learning behaviour of the policy and move out from the linear reward to the achievement formula. The training was conducted based on fixed target tracking followed by moving target tracking. The flight testing was conducted based on three types of target trajectories: fixed, square, and blinking. The multistage training achieved the best performance with both exponential and achievement rewarding for the fixed trained agent with the fixed and square moving target and for the combined agent with both exponential and achievement rewarding for a fixed trained agent in the case of a blinking target. With respect to the traditional proportional differential controller, the maximum error reduction rate is 86%. The developed achievement rewarding and the multistage training opens the door to various applications of RL in target tracking.

Labor multi-activity in agricultural production within Mexico’s less urbanized contexts: 1993 and 2003

An aspect continuously mentioned in research on rural contexts concerns the multi-activity of agricultural workers. Several studies analyze the various work combinations that may occur in a household in order to explain the different social and family reproduction patterns; while others studies approach the debate from the perspective of the different sources of income obtained by rural households. This paper explores the issue of multi-activity by analyzing the work itineraries an individual might undertake during a six-month period, while attempting to answer the question: ?what factors influence the type of labor trajectory of agricultural workers?

Stability of a vertical descent of a heavy finned body in resisting medium

A free descent of a finned body in resisting medium is studied. Fins are installed in such a way that there is a regime of a translational descent with a constant speed. Beforehand, a descent of a heavy body in an autorotation mode was studied. It exists when pitch angles of all fins are equal to each other. For a descent with autorotation, general properties and tendencies of motion were described depending on initial conditions and parameters. In the current paper, the descent of a body is discussed for the case when fins have equal absolute values of pitch angles, but signs of these angles alternate. Asymptotic stability of a translational descent with a constant speed is studied for such orientation of fins. Domains of stability are constructed in the plane of the following parameters: pitch angle of fins and displacement of the center of mass. Fins represented either by circle or rectangular blades are discussed. Domains of stability are compared with that for the autorotation mode descent. Trajectories of the center of mass are constructed. Varied types of such trajectories are obtained when parameters of the model correspond to the case of unstable translational descents with a constant speed.

Language, analogical reasoning, and working memory skills in emergent literacy period: Typical and DLD trajectories via Cluster Analyses

The aim of the present study was to compare emergent literacy profiles among Spanish-speaking preschoolers with and without developmental language disorders (DLD), based on phonological and lexical skills, working memory (WM), and analogical reasoning (AR, including verbal and nonverbal). The study sample was composed of 123 children aged 47- 62 months (age group 1 or G1:M = 55.09, SD = 4.52; 61 boys, 62 girls) and 115 children aged 63–78 months (age group 2 or G2:M = 69.27, SD = 4.16; 54 boys, 61 girls). We compared the performance by age group in all measures, after which hierarchical cluster analyses using emergent literacy scores were performed for each age group. The linguistic and cognitive factors of the resulting clusters were compared using the Kruskal-Wallis test and pairwise comparison. Cluster analysis yielded 3 clusters in each age group that significantly differed on linguistic and cognitive measures. The groups were identified as high, mid, and low performance. DLD groups were associated with low performance in listening comprehension, lexical decision, and syllabification in G1 and lexical repetition and final sound in G2. The high-performance groups were associated with higher performance in syllabification, initial sound, and lexical repetition in G1 and listening comprehension in G2. The main differences between age groups were observed in syllabification and lexical decision. Furthermore, the results suggest that verbal AR and WM are positive markers of linguistic profiles in the youngest group, while only verbal AR appears relevant in the oldest group. These findings highlight the heterogeneity of emergent literacy profiles and may enhance the understanding of language and literacy development in typical and DLD Spanish-speaking children.

Investigations of the algorithms linear properties for strapdown inertial navigation systems

The basic operation principles of the strapdown inertial navigation systems (SINS) without platform and models of the measuring sensors errors, including offsets of zero signals, errors of scale factors and cross-links connections, are considered. The influence of various components of these errors and their linear combinations on the numeration accuracy of coordinates, velocity and orientation angles is investigated by the method of mathematical modeling of the SINS operation at one and a half hour intervals. To assess the linear properties of SINS algorithms, a quantitative measure is introduced — the value of the numeration error deviation, caused by a linear combination of input errors, relative linear combination of errors caused by separate input errors, as a percentage is expressed. Numerical estimates for typical trajectories of a maneuverable aircraft are obtained for this value. The obtained results can serve as the basis for the formation of technical requirements, used at the design and testing of aviation navigation systems and complexes. Keywords strapdown inertial navigation system, potential of the gravity field, gravitational acceleration, apparent acceleration, numeration errors, math modeling

Interactive Simulation Program for Autonomous Vehicles

The paper presents an interactive simulation program dedicated to autonomous vehicles. The program, developed in the form of an app and written in the Matlab programming language, is a didactic tool, which aims to better understand the phenomena that occur during locomotion. To achieve this goal, the user can easily perform interactive simulations by changing the model parameters. In addition to the mentioned flexibility, the user can perform case studies and scenarios. The structure of the program is obtained by aggregating seven objects (modules), dedicated to studying the contributions of each to the simulation. These modules are for different types of trajectories, for controllers, three types of locomotion models, sensors, different filters, environment models, and for simultaneous localization and mapping. The connection between them is possible through a database. This framework ensures the continuity of the simulations. At the end of the interactive visual simulation, the user is obtaining a holistic report with the results.

Integrated Mobile Robotic Platform Model

Introduction. The “Smart Agroˮ committee of Research and Education Center “Engineering of the Future” has identified a number of tasks relevant for improving the efficiency of precision, soil-protecting and conservation agriculture. One of these tasks is the development of a digital multi-agent system, which provides a number of services for agricultural enterprises, developers and manufacturers of agricultural machinery. The purpose of the present study is to model an autonomous mobile robotic platform, including the development of software and hardware for trajectory control. Materials and Methods. To solve the problem, there are used modern CAx systems and their applications, the methods of 3D and full-body modeling, and the method of numerical solution of problems in solid mechanics. To expand and improve the standard functionality of CAx-systems (SolidWorks) in the software implementation of trajectory control algorithms, the methods and technologies of programming using API SolidWorks, VisualStudio C++ (MFC, ATL, COM) are used, and to build physical full-scale models ‒ Arduino and fischertechnik platforms. Results. The result of the study is a software and hardware module of trajectory control for an integrated (physical and virtual) model of a mobile robotic platform, which can be provided to the consumer as a service for technology autonomation. For the developed integrated model, control algorithms for various types of trajectories were tested. Discussion and Conclusion. The developed integrated software and hardware model of trajectory control can be used by developers and manufacturers of agricultural machinery, and directly by agro-enterprises for implementing typical technological processes. A feature of the implementation is an open hardware and software interface that provides the integration of mobile robotic platforms based on a digital multi-agent system.

Features of gas inflow to a horizontal wellbore at various trajectories

This article discusses the effect of wellbore trajectory on the flow performance of a horizontal cased and perforated gas well. We used a coupled well-reservoir flow model, taking into account the nature of the flow, and local hydraulic resistances of the wellbore, and thus determined the pressure and mass flow distribution along the horizontal wellbore for several types of trajectories, including undulated and toe-up trajectories. The simulation results showed the effect of horizontal gas well trajectory type on its flow rate and the importance of considering pressure distribution to optimize well design.