Exploring the impact of unstable terminals on branch support values in paleontological data

Paleobiology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Jorge R. Flores ◽  
Samuli Lehtonen ◽  
Jaakko Hyvönen
Keyword(s):  
Missing Data ◽  
Phylogenetic Inference ◽  
Future Research ◽  
Typical Problem ◽  
Long Branch Attraction ◽  
Paleontological Data ◽  
Root Node ◽  
Branch Support ◽  
The Many ◽  
The Impact

Abstract Recent studies have acknowledged the many benefits of including fossils in phylogenetic inference (e.g., reducing long-branch attraction). However, unstable taxa are known to be problematic, as they can reduce either the resolution of the strict consensus or branch support. In this study, we evaluate whether unstable taxa that reduce consensus resolution affect support values, and the extent of such impact, under equal and extended implied weighting. Two sets of analyses were conducted across 30 morphological datasets to evaluate complementary aspects. The first focused on the analytical conditions incrementing the terminal instability, while the second assessed whether pruning wildcards improves support. Changes in support were compared with the “number of nodes collapsed by unstable terminals,” their “distance to the root,” the “proportion of missing data in a dataset,” and the “proportion of sampled characters.” Our results indicate that the proportion of missing entries distributed among closely related taxa (for a given character) might be as detrimental for stability as those distributed among characters (for a given terminal). Unstable terminals that (1) collapse few nodes or (2) are closely located to the root node have more influence on the estimated support values. Weighting characters according to their extra steps while assuming that missing entries contribute to their homoplasy reduced the instability of wildcards. Our results suggest that increasing character sampling and using extended implied weighting decreases the impact of wildcard terminals. This study provides insights for designing future research dealing with unstable terminals, a typical problem of paleontological data.

Poverty Reduction Through Microfinance

2022 ◽  
pp. 187-216
Keyword(s):  
Rural Women ◽  
Poverty Reduction ◽  
Research Trends ◽  
Future Research ◽  
Poor People ◽  
African Countries ◽  
Extreme Poverty ◽  
The Many ◽  
The Impact ◽  
Essential Path

Microfinance is believed by many people in Africa to allow poor people to protect, diversify, and increase their sources of income, which is known to be the essential path out of poverty and hunger. This chapter examines whether microfinance can really help to reduce poverty. The enduring question is: Can microfinance be the game changer that will lift the many poor rural women and men in Africa out of the misery of extreme poverty? Is this strategy bliss or myth? First, the author provides a context and rationale for microfinance in African countries. Second, the chapter follows a brief overview of the literature on the impact of microfinance on women's empowerment and whether credit lending transactions benefit the intended recipients. Finally, the chapter reviews the arguments of both sides of the debate and draws out future research trends.

Health Misinformation

2021 ◽  
Author(s):  
Xiaoli Nan ◽  
Yuan Wang ◽  
Kathryn Thier
Keyword(s):  
Scientific Information ◽  
Conclusive Evidence ◽  
Future Research ◽  
Health Issues ◽  
The Many ◽  
Many Sources ◽  
Feature Negative ◽  
The Impact ◽  
And Diffusion ◽  
Harmful Effects

Research on health misinformation has grown rapidly as concerns about the potential harmful effects of health misinformation on individuals and society intensify amid a “post-truth” era. In this chapter, we provide a broad overview of current research and evidence concerning the many facets of health misinformation, including its sources, prevalence, characteristics (both content and diffusion features), impact, and mitigation. We conclude that health misinformation originates from many sources, most notably mass and social media; is fairly prevalent, both in interpersonal and mediated settings; and tends to feature negative sentiments, anecdotal evidence, and anti-science narratives. Although there is no conclusive evidence that health misinformation spreads more broadly than scientific information, health misinformation reliably leads to misperceptions on health issues. Efforts to mitigate the impact of health misinformation show early promise in correcting misperceptions. We offer several directions for future research.

scholarly journals Applying Many-Facet Rasch Modeling in the Assessment of Creativity

2018 ◽  
Author(s):  
Ricardo Primi ◽  
Paul Silvia ◽  
Mathias Benedek ◽  
Emanuel Jauk
Keyword(s):  
Missing Data ◽  
Measurement Error ◽  
Rasch Model ◽  
Reliability And Validity ◽  
Creativity Assessment ◽  
Creativity Research ◽  
Powerful Means ◽  
The Many ◽  
The Impact

Creativity assessment with open-ended production tasks relies heavily on scoring the quality of a subject’s ideas. This creates a faceted measurement structure involving persons, tasks (and ideas within tasks), and raters. Most studies, however, don’t model possible systematic differences among raters. The present study examines the impact of individual rater differences in the reliability and validity of creativity assessments. It applies the Many-Facet-Rasch-Model (MFRM) to model and correct for these differences. We reanalyzed data from two studies (Ns=132 and 298) where subjects produced metaphors, alternate uses for common objects, and creative instances. Each idea was scored by two to four raters. We simulated several conditions of reduced load on raters where they scored subsets of responses. We then compared the reliability and validity of IRT estimated scores (original versus IRT adjusted) on various conditions of missing data. Results show that (a) raters vary substantially on the lenient-severity dimension, so rater differences should be modeled; (b) when different combinations of raters assess different subsets of ideas, systematic rater differences confound subjects’ scores, increasing measurement error and lowering validity; and (c) MFRM adjustments effectively correct for rater effects, thus increasing validity. We conclude that MFRM is a powerful means to model rater differences and reduce rater load in creativity research.

scholarly journals Health Misinformation

2020 ◽  
Author(s):  
Xiaoli Nan ◽  
Yuan Wang ◽  
Kathryn Thier
Keyword(s):  
Scientific Information ◽  
Conclusive Evidence ◽  
Future Research ◽  
Health Issues ◽  
The Many ◽  
Many Sources ◽  
Feature Negative ◽  
The Impact ◽  
And Diffusion ◽  
Harmful Effects

Research on health misinformation has grown rapidly as concerns about the potential harmful effects of health misinformation on individuals and society intensify amid a “post-truth” era. In this chapter, we provide a broad overview of current research and evidence concerning the many facets of health misinformation, including its sources, prevalence, characteristics (both content and diffusion features), impact, and mitigation. We conclude that health misinformation originates from many sources, most notably mass and social media, is fairly prevalent, both in interpersonal and mediated settings, and tends to feature negative sentiments, anecdotal evidence, and anti-science narratives. While there is no conclusive evidence that health misinformation spreads more broadly than scientific information, health misinformation reliably leads to misperceptions on health issues. Efforts to mitigate the impact of health misinformation show early promise in correcting misperceptions. We offer several directions for future research, including a call for more investigations on the impact of health misinformation and correcting messages on actual behaviors.

scholarly journals What do we know about the impact of stress on foster carers and contributing factors?

2018 ◽  
Vol 42 (4) ◽  
pp. 338-353 ◽  
Author(s):  
Emma Adams ◽  
Alexander R Hassett ◽  
Virginia Lumsden
Keyword(s):  
Future Research ◽  
Inclusion Criteria ◽  
Contributing Factors ◽  
Effective Training ◽  
Children’S Behaviour ◽  
The Many ◽  
System Variables ◽  
Training And Support ◽  
The Impact ◽  
Service Framework

Research has highlighted the many challenges that foster carers face in caring for children who have experienced adversity and has charted a growing mismatch between the numbers of children needing placements and the availability of carers. This review synthesises and evaluates the current empirical evidence on the causes and consequences of stress experienced by foster carers and the factors that lessen or increase it. PsychINFO, ASSIA, Web of Science and Google Scholar were searched for relevant studies, 15 of which met the specific inclusion criteria. The factors identified included both system variables, such as working in a wider service framework, and individual ones, such as children’s behaviour. One consequence of this stress was reduced foster carer retention. Scrutiny of the papers also revealed methodological issues related to sampling, research design and cultural variability. Topics for future research were identified, especially an analysis of the perspectives of people involved in the system around foster carers, such as social workers and the carers’ birth children. Clinical implications were also highlighted, most notably the promotion and provision of effective training and support and the development of integrated ways of working with services and foster carers’ families.

scholarly journals Death is on Our Side: Paleontological Data Drastically Modify Phylogenetic Hypotheses

2020 ◽  
Vol 69 (6) ◽  
pp. 1052-1067 ◽  
Author(s):  
Nicolás Mongiardino Koch ◽  
Luke A Parry
Keyword(s):  
Empirical Studies ◽  
Phylogenetic Inference ◽  
Early Years ◽  
Total Evidence ◽  
Character State ◽  
Distinctive Character ◽  
Remarkable Effect ◽  
Paleontological Data ◽  
Phylogenetic Hypotheses ◽  
The Impact

Abstract Fossils are the only remaining evidence of the majority of species that have ever existed, providing a direct window into events in evolutionary history that shaped the diversification of life on Earth. Phylogenies underpin our ability to make sense of evolution but are routinely inferred using only data available from living organisms. Although extinct taxa have been shown to add crucial information for inferring macroevolutionary patterns and processes (such as ancestral states, paleobiogeography and diversification dynamics), the role fossils play in reconstructing phylogeny is controversial. Since the early years of phylogenetic systematics, different studies have dismissed the impact of fossils due to their incompleteness, championed their ability to overturn phylogenetic hypotheses or concluded that their behavior is indistinguishable from that of extant taxa. Based on taxon addition experiments on empirical data matrices, we show that the inclusion of paleontological data has a remarkable effect in phylogenetic inference. Incorporating fossils often (yet not always) induces stronger topological changes than increasing sampling of extant taxa. Fossils also produce unique topological rearrangements, allowing the exploration of regions of treespace that are never visited by analyses of only extant taxa. Previous studies have proposed a suite of explanations for the topological behavior of fossils, such as their retention of unique morphologies or their ability to break long branches. We develop predictive models that demonstrate that the possession of distinctive character state combinations is the primary predictor of the degree of induced topological change, and that the relative impact of taxa (fossil and extant) can be predicted to some extent before any phylogenetic analysis. Our results bolster the consensus of recent empirical studies by showing the unique role of paleontological data in phylogenetic inference, and provide the first quantitative assessment of its determinants, with broad consequences for the design of taxon sampling in both morphological and total-evidence analyses. [phylogeny, morphology, fossils, parsimony, Bayesian inference.]

scholarly journals Death is on Our Side: Paleontological Data Drastically Modify Phylogenetic Hypotheses

2019 ◽  
Author(s):  
Nicolás Mongiardino Koch ◽  
Luke A. Parry
Keyword(s):  
Empirical Studies ◽  
Phylogenetic Inference ◽  
Early Years ◽  
Total Evidence ◽  
Character State ◽  
Distinctive Character ◽  
Remarkable Effect ◽  
Paleontological Data ◽  
Phylogenetic Hypotheses ◽  
The Impact

ABSTRACTFossils are the only remaining evidence of the majority of species that have ever existed, providing a direct window into events in evolutionary history that shaped the diversification of life on Earth. Phylogenies underpin our ability to make sense of evolution but are routinely inferred only from data available from living organisms. Although extinct taxa have been shown to add crucial information for inferring macroevolutionary patterns and processes including ancestral states, paleobiogeography and diversification dynamics, the role that fossils play in inferring the tree of life itself is controversial. Since the early years of phylogenetic systematics, different studies have dismissed the impact of fossils due to their incompleteness, championed their ability to overturn phylogenetic hypotheses or concluded that their behavior is indistinguishable from that of extant taxa. Here we show paleontological data has a remarkable effect in phylogenetic inference. Fossils often have higher levels of topological influence than extant taxa, while inducing unique topological rearrangements. Previous studies have proposed a suite of explanations for the topological behavior of fossils, such as their retention of unique morphologies or their ability to break long branches. We develop predictive models that demonstrate that the possession of distinctive character state combinations is the primary predictor of the degree of induced topological change, and that the relative impact of taxa (fossil and extant) can be predicted to some extent before any analysis. Our results bolster the consensus of recent empirical studies by showing the unique role of paleontological data in phylogenetic inference, and provide the first quantitative assessment of its determinants, with broad consequences for the design of taxon sampling in both morphological and total-evidence analyses.

scholarly journals Health Misinformation

2021 ◽  
Author(s):  
Xiaoli Nan ◽  
Yuan Wang ◽  
Kathryn Thier
Keyword(s):  
Scientific Information ◽  
Conclusive Evidence ◽  
Future Research ◽  
Health Issues ◽  
The Many ◽  
Many Sources ◽  
Feature Negative ◽  
The Impact ◽  
And Diffusion ◽  
Harmful Effects

Research on health misinformation has grown rapidly as concerns about the potential harmful effects of health misinformation on individuals and society intensify amid a “post-truth” era. In this chapter, we provide a broad overview of current research and evidence concerning the many facets of health misinformation, including its sources, prevalence, characteristics (both content and diffusion features), impact, and mitigation. We conclude that health misinformation originates from many sources, most notably mass and social media; is fairly prevalent, both ininterpersonal and mediated settings; and tends to feature negative sentiments, anecdotal evidence, and anti-science narratives. Although there is no conclusive evidence that health misinformation spreads more broadly than scientific information, health misinformation reliably leads to misperceptions on health issues. Efforts to mitigate the impact of health misinformation show early promise in correcting misperceptions. We offer several directions for future research.

scholarly journals Impact of HR Practices on Employee Turnover and Job Satisfaction: Evidence from Pakistani Universities

2020 ◽  
Vol 6 (3) ◽  
pp. 607-624
Author(s):  
Shakeel Khan ◽  
Muhammad Hashim Khan ◽  
Ali Muhammad Mohmand ◽  
Syeda Misbah
Keyword(s):  
Job Satisfaction ◽  
Performance Appraisal ◽  
Employee Participation ◽  
Working Environment ◽  
Future Research ◽  
Hr Practices ◽  
And Performance ◽  
And Gender ◽  
The Many ◽  
The Impact

This research examines the impact of pertinent HR practices/policies upon a person’s job contentment and turnover in higher educational institutes. A special context of universities of KP have been chosen where numerous employees have developed job dissatisfaction and increased turnover because of deteriorating security conditions including but not limited to terrorism attacks, civil unrest, widespread diseases and unconducive working environment. This has ultimately compelled them to leave their jobs and flee to other cities such as Islamabad and Karachi.  More specifically, three HR policies i.e. employee participation, training and performance appraisal are analysed to affect job satisfaction and turnover. A quantitative survey was conducted to assess job outcomes of University teachers in multiple cities especially where living conditions have deteriorated in the recent past. Respondents were segregated on the basis of age, income per month, designation and gender basis. Frequency analysis and Mean Average Scores are reported for each construct. The regression results suggest a positive significant relation of employee participation and performance appraisal with that of job satisfaction while a significant negative relation is found with turnover ratio. The study concludes that universities should focus on implementing HR policies and practices effectively in workplace which will help retain employees and keep them motivated. This can be one of the many effective strategies to retain workforce and discourage brain-drain out of the country. The study ends with acknowledging limitations and offering future research directions.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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