scholarly journals A novel framework for classification of selection processes in epidemiological research

2020 ◽  
Author(s):  
Jonas Bjork ◽  
Anton Nilsson ◽  
Carl Bonander ◽  
Ulf Strömberg
Keyword(s):  
Research Question ◽  
Population Level ◽  
Three Dimensions ◽  
Observational Research ◽  
Population Composition ◽  
Epidemiological Research ◽  
Selection Processes ◽  
Underlying Mechanisms ◽  
Case Basis

Abstract Background: Selection and selection bias are terms that lack consistent definitions and have varying meaning and usage across disciplines. There is also confusion in current definitions between underlying mechanisms that lead to selection and their consequences. Consequences of selection on study validity must be judged on a case-by-case basis depending on research question, study design and analytical decisions. The overall aim of the study was to develop a simple but general framework for classifying various types of selection processes of relevance for epidemiological research. Methods: Several original articles from the epidemiological literature and from related areas of observational research were reviewed in search of examples of selection processes, used terminology and description of the underlying mechanisms. Results: We classified the identified selection processes in three dimensions: i) selection level (selection at the population level vs. study-specific selection), ii) type of mechanism (selection in exposure vs. selection in population composition), iii) timing of the selection (at exposure entry, during exposure or post-outcome). Conclusions: Increased understanding of when, how, and why selection occur is an important step towards improved validity of epidemiological research.

scholarly journals A novel framework for classification of selection processes in epidemiological research

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jonas Björk ◽  
Anton Nilsson ◽  
Carl Bonander ◽  
Ulf Strömberg
Keyword(s):  
Research Question ◽  
Population Level ◽  
Three Dimensions ◽  
Observational Research ◽  
Epidemiological Research ◽  
Selection Processes ◽  
Underlying Mechanisms ◽  
Case Basis

Abstract Background Selection and selection bias are terms that lack consistent definitions and have varying meaning and usage across disciplines. There is also confusion in current definitions between underlying mechanisms that lead to selection and their consequences. Consequences of selection on study validity must be judged on a case-by-case basis depending on research question, study design and analytical decisions. The overall aim of the study was to develop a simple but general framework for classifying various types of selection processes of relevance for epidemiological research. Methods Several original articles from the epidemiological literature and from related areas of observational research were reviewed in search of examples of selection processes, used terminology and description of the underlying mechanisms. Results We classified the identified selection processes in three dimensions: i) selection level (selection at the population level vs. study-specific selection), ii) type of mechanism (selection in exposure vs. selection in population composition), iii) timing of the selection (at exposure entry, during exposure/follow-up or post-outcome). Conclusions Increased understanding of when, how, and why selection occur is an important step towards improved validity of epidemiological research.

scholarly journals A novel framework for classification of selection processes in epidemiological research

2020 ◽  
Author(s):  
Jonas Bjork ◽  
Anton Nilsson ◽  
Carl Bonander ◽  
Ulf Strömberg
Keyword(s):  
Research Question ◽  
Population Level ◽  
Three Dimensions ◽  
Observational Research ◽  
Epidemiological Research ◽  
Selection Processes ◽  
Underlying Mechanisms ◽  
Case Basis

Abstract Background: Selection and selection bias are terms that lack consistent definitions and have varying meaning and usage across disciplines. There is also confusion in current definitions between underlying mechanisms that lead to selection and their consequences. Consequences of selection on study validity must be judged on a case-by-case basis depending on research question, study design and analytical decisions. The overall aim of the study was to develop a simple but general framework for classifying various types of selection processes of relevance for epidemiological research. Methods: Several original articles from the epidemiological literature and from related areas of observational research were reviewed in search of examples of selection processes, used terminology and description of the underlying mechanisms. Results: We classified the identified selection processes in three dimensions: i) selection level (selection at the population level vs. study-specific selection), ii) type of mechanism (selection in exposure vs. selection in population composition), iii) timing of the selection (at exposure entry, during exposure/follow-up or post-outcome). Conclusions: Increased understanding of when, how, and why selection occur is an important step towards improved validity of epidemiological research.

scholarly journals A novel framework for classification of selection mechanisms in epidemiological research

2019 ◽  
Author(s):  
Jonas Bjork ◽  
Anton Nilsson ◽  
Carl Bonander ◽  
Ulf Strömberg
Keyword(s):  
General Framework ◽  
Empirical Studies ◽  
Population Level ◽  
Epidemiological Studies ◽  
Three Dimensions ◽  
Epidemiological Research ◽  
Selection Processes ◽  
Selection Mechanisms

Abstract Background: Non-participation, losses to follow up and other types of study-specific selection mechanisms can be serious concerns in epidemiological studies. There are also selection processes that result in non-random groupings and changes in the composition of populations. These are continuously on-going irrespectively of whether they are subject to sampling in empirical studies. Such population selections are often overlooked, but may lead to lack of comparability of exposed and unexposed populations or decrease study validity in other ways. The overall aim of this study was to develop a simple but general framework for classifying various types of selection mechanisms of relevance for epidemiological research. Methods: We classify selection mechanisms in three dimensions: i) selection at the population level vs. selection that is study-specific, ii) type of mechanism (selection causing exposure vs. selection in population at risk), iii) timing of the selection (pre-exposure, during exposure or post-outcome). Results: Examples from the epidemiological literature of selection mechanisms are discussed and classified according to the three dimensions of the proposed framework. Conclusions: Increased mechanistic understanding of when, how, and why confusion of effects can occur because of selection is an important step towards improved validity of epidemiological research.

scholarly journals Towards a contemporary approach for understanding personality pathology in developmental context: An integrative model

2021 ◽  
pp. 1-10
Author(s):  
Melody R. Altschuler ◽  
Robert F. Krueger
Keyword(s):  
Personality Disorders ◽  
Personality Pathology ◽  
Integrative Model ◽  
Research Domain Criteria ◽  
Developmental Context ◽  
Dimensional Classification ◽  
Developmental Theories ◽  
Underlying Mechanisms ◽  
Research Domain

Abstract Traditional categorical approaches to classifying personality disorders are limited in important ways, leading to a shift in the field to dimensional approaches to conceptualizing personality pathology. Different areas of psychology – personality, developmental, and psychopathology – can be leveraged to understand personality pathology by examining its structure, development, and underlying mechanisms. However, an integrative model that encompasses these distinct lines of inquiry has not yet been proposed. In order to address this gap, we review the latest evidence for dimensional classification of personality disorders based on structural models of maladaptive personality traits, provide an overview of developmental theories of pathological personality, and summarize the Research Domain Criteria (RDoC) initiative, which seeks to understand underlying mechanisms of psychopathology. We conclude by proposing an integrative model of personality pathology development that aims to elucidate the developmental pathways of personality pathology and its underlying mechanisms.

scholarly journals Hip Fracture Types in Canadian Men and Women Change Differently with Age: A Population-Level Analysis

2016 ◽  
Vol 9 ◽  
pp. CMAMD.S38531 ◽  
Author(s):  
Richard G. Crilly ◽  
Marita Kloseck ◽  
Selam Mequanint
Keyword(s):  
Hip Fracture ◽  
Relative Proportion ◽  
Local Population ◽  
Population Level ◽  
Community Dwelling ◽  
Administrative Database ◽  
Fracture Type ◽  
Discharge Abstract Database ◽  
Fracture Types

Background We have previously reported a gender difference in the occurrence of hip fracture type with age in our local population. In the current report, we have explored this phenomenon in a Canadian population using five years of data from a national administrative database. We have compared community-dwelling and institutionalized individuals to determine if frailty is important and has a differential effect on the type of hip fracture experienced. Methods Hospitalization records from 2005 to 2009, in which the most responsible diagnosis, that is the diagnosis causing the admission to hospital, was a hip fracture, were obtained from the Discharge Abstract Database of the Canadian Institute for Health Information. Hip fracture type was identified using the Canadian Classification of Health Interventions and the International Classification of Diseases 10th Revision, Canada (ICD-10-CA). Hip fracture proportions were calculated for the study period and stratified by age group and sex. Results The relative proportion of intertrochanteric fractures in women rose from 35% in the youngest group (55–59 years) to 51% in the oldest group (84+ years; P < 0.0001). In men, the proportions remain relatively stable (47% and 44%, respectively). Community and institutionalized patients showed the same pattern. Conclusions The change in the proportion of the two hip fracture types that occur in women but not men may point to differences in the etiology and consequently the approaches to prevention for the two fracture types. Level of frailty did not seem to be important.

Color naming, unique hues, and hue cancellation predicted from singularities in reflection properties

2006 ◽  
Vol 23 (3-4) ◽  
pp. 331-339 ◽  
Author(s):  
DAVID L. PHILIPONA ◽  
J. KEVIN O'REGAN
Keyword(s):  
Color Naming ◽  
Surface Reflection ◽  
Unique Hues ◽  
Neuronal Representation ◽  
Underlying Mechanisms ◽  
The One ◽  
Unique Green ◽  
Psychophysical Studies ◽  
Hue Cancellation

Psychophysical studies suggest that different colors have different perceptual status: red and blue for example are thought of as elementary sensations whereas yellowish green is not. The dominant account for such perceptual asymmetries attributes them to specificities of the neuronal representation of colors. Alternative accounts involve cultural or linguistic arguments. What these accounts have in common is the idea that there are no asymmetries in the physics of light and surfaces that could underlie the perceptual structure of colors, and this is why neuronal or cultural processes must be invoked as the essential underlying mechanisms that structure color perception. Here, we suggest a biological approach for surface reflection properties that takes into account only the information about light that is accessible to an organism given the photopigments it possesses, and we show that now asymmetries appear in the behavior of surfaces with respect to light. These asymmetries provide a classification of surface properties that turns out to be identical to the one observed in linguistic color categorization across numerous cultures, as pinned down by cross cultural studies. Further, we show that data from psychophysical studies about unique hues and hue cancellation are consistent with the viewpoint that stimuli reported by observers as special are those associated with this singularity-based categorization of surfaces under a standard illuminant. The approach predicts that unique blue and unique yellow should be aligned in chromatic space while unique red and unique green should not, a fact usually conjectured to result from nonlinearities in chromatic pathways.

scholarly journals Three-Dimensional Trajectory Construction and Observation of Group Behavior of Wild Bats During Cave Emergence

2021 ◽  
Vol 33 (3) ◽  
pp. 556-563
Author(s):  
Emyo Fujioka ◽  
Mika Fukushiro ◽  
Kazusa Ushio ◽  
Kyosuke Kohyama ◽  
Hitoshi Habe ◽  
...  
Keyword(s):  
Quantitative Estimation ◽  
Three Dimensional ◽  
Experimental System ◽  
High Sensitivity ◽  
Group Behavior ◽  
Three Dimensions ◽  
Detection And Tracking ◽  
External Objects ◽  
Behavioral Classification

Echolocating bats perceive the surrounding environment by processing echoes of their ultrasound emissions. Echolocation enables bats to avoid colliding with external objects in complete darkness. In this study, we sought to develop a method for measuring the collective behavior of echolocating bats (Miniopterus fuliginosus) emerging from their roost cave using high-sensitivity stereo-camera recording. First, we developed an experimental system to reconstruct the three-dimensional (3D) flight trajectories of bats emerging from the roost for nightly foraging. Next, we developed a method to automatically track the 3D flight paths of individual bats so that quantitative estimation of the population in proportion to the behavioral classification could be conducted. Because the classification of behavior and the estimation of population size are ecologically important indices, the method established in this study will enable quantitative investigation of how individual bats efficiently leave the roost while avoiding colliding with each other during group movement and how the group behavior of bats changes according to weather and environmental conditions. Such high-precision detection and tracking will contribute to the elucidation of the algorithm of group behavior control in creatures that move in groups together in three dimensions, such as birds.

Theoretical conceptions of intervention research addressing cancer control issues

2020 ◽  
Author(s):  
Cécile-Marie Dupin ◽  
Carla Estaquio ◽  
Hermann Nabi
Keyword(s):  
Methodological Approach ◽  
Health Sector ◽  
Cancer Control ◽  
Population Level ◽  
Intervention Research ◽  
Research Field ◽  
Population Health Intervention Research ◽  
Population Health Intervention ◽  
Underlying Mechanisms ◽  
New Research

Abstract Population health intervention research (PHIR) involves the use of scientific methods to produce knowledge about policy and program interventions that operate within or outside of the health sector and have the potential to impact health at the population level. PHIR is a relatively new research field that has gained momentum internationally. When developing PHIR, it is important to have a program theory with the potential to increase intervention success by identifying underlying mechanisms, areas of failure and unintended outcomes. Since 2010, the French National Cancer Institute (Institut National du Cancer—INCa) has supported a national, competitive, dedicated call for proposals in PHIR to tackle cancer control issues. After 5 years of activity, specific analysis of the proposals submitted for funding and/or funded (n = 63) from descriptive and analytic perspectives was called for. Analysis of the data revealed diversity in terms of targeted populations, partnerships engaged and methodological approaches. Projects were more likely to be funded (n = 15) if presented with a robust methodological approach and diversity in methodology, and/or with research objectives at different levels of action. The analysis also revealed that researchers do not explicitly describe theoretical constructs underpinning their interventions to combat cancer. PHIR still needs improvement to better incorporate social, institutional and policy approaches to cancer control. Researchers should apply a theory-driven approach to distinguish between ‘program failure’ and ‘theory failure’. Following up the funded projects will allow successes and failures to be evaluated with respect to the use (or non-use) of theory-driven approaches.

Plant Ecophysiology: Linking Pattern and Process—a Review

1997 ◽  
Vol 45 (2) ◽  
pp. 351
Author(s):  
Jann Williams ◽  
Derek Eamus
Keyword(s):  
Plant Ecophysiology ◽  
Elevated Atmospheric Co2 ◽  
Pattern And Process ◽  
Ecological Society ◽  
Technological Advances ◽  
Ecological Patterns ◽  
Underlying Mechanisms ◽  
Underlying Processes

Introduction The Symposium ‘Plant Ecophysiology: Linking Pattern and Process’ was held as part of the 1995 meeting of the Ecological Society of Australia (ESA). The aim of the Symposium was to highlight work that examined mechanisms underlying ecological patterns and linked them to ecological and/or evolutionary processes. Another aim was to expose ecologists to the methods available to examine the mechanistic and functional basis of the organisms and systems under study. Much early ecological research has been concerned with the description and classification of vegetation types, with relatively little effort devoted to understanding the underlying processes that determined distribution. A more quantitative approach based on knowledge of the underlying mechanisms can further improve understanding of systems. This was amply demonstrated in a Symposium on the effects of elevated atmospheric CO2 on vegetation dynamics, also held in conjunction with an ESA meeting (see papers in Australian Journal of Botany, Volume 40(2)). Recent technological advances have stimulated rapid progress in the field of ecophysiology and hence an increasing process-based understanding is developing. The 1995 Symposium was seen as an opportunity to highlight more recent work in what is a relatively new field in Australia (albeit a well-established field in Europe and America), especially in situ studies and research from relatively little studied areas like northern Australia. The response to the Symposium was encouraging, with 25 spoken papers and poster-papers presented. In this paper, some of the unifying aspects of the papers presented in the symposium are drawn together, and placed in the context of likely future developments in ecophysiology in Australia. Based on this analysis, future directions and gaps are identified.

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