Consciousness and biological evolution.

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Lindahl, B I

1997-08-21

It has been suggested that if the preservation and development of consciousness in the biological evolution is a result of natural selection, it is plausible that consciousness not only has been influenced by neural processes, but has had a survival value itself; and it could only have had this, if it had also been efficacious. This argument for mind-brain interaction is examined, both as the argument has been developed by William James and Karl Popper and as it has been discussed by C.D. Broad. The problem of identifying mental phenomena with certain neural phenomena is also addressed. The main conclusion of the analysis is that an explanation of the evolution of consciousness in Darwinian terms of natural selection does not rule out that consciousness may have evolved as a mere causally inert effect of the evolution of the nervous system, or that mental phenomena are identical with certain neural phenomena. However, the interactionistic theory still seems, more plausible and more fruitful for other reasons brought up in the discussion.

Hierarchy, causation and explanation: ubiquity, locality and pluralism

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Love, Alan C.

2012-01-01

The ubiquity of top-down causal explanations within and across the sciences is prima facie evidence for the existence of top-down causation. Much debate has been focused on whether top-down causation is coherent or in conflict with reductionism. Less attention has been given to the question of whether these representations of hierarchical relations pick out a single, common hierarchy. A negative answer to this question undermines a commonplace view that the world is divided into stratified ‘levels’ of organization and suggests that attributions of causal responsibility in different hierarchical representations may not have a meaningful basis for comparison. Representations used in top-down and bottom-up explanations are primarily ‘local’ and tied to distinct domains of science, illustrated here by protein structure and folding. This locality suggests that no single metaphysical account of hierarchy for causal relations to obtain within emerges from the epistemology of scientific explanation. Instead, a pluralist perspective is recommended—many different kinds of top-down causation (explanation) can exist alongside many different kinds of bottom-up causation (explanation). Pluralism makes plausible why different senses of top-down causation can be coherent and not in conflict with reductionism, thereby illustrating a productive interface between philosophical analysis and scientific inquiry. PMID:23386966

Antimicrobial resistance and biological governance: explanations for policy failure.

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Wallinga, D; Rayner, G; Lang, T

2015-10-01

The paper reviews the state of policy on antimicrobial use and the growth of antimicrobial resistance (AMR). AMR was anticipated at the time of the first use of antibiotics by their originators. For decades, reports and scientific papers have expressed concern about AMR at global and national policy levels, yet the problem, first exposed a half-century ago, worsened. The paper considers the explanations for this policy failure and the state of arguments about ways forward. These include: a deficit of economic incentivisation; complex interventions in behavioural dynamics; joint and separate shifts in medical and animal health regimes; consumerism; belief in technology; and a narrative that in a 'war on bugs' nature can be beaten by human ingenuity. The paper suggests that these narratives underplay the biological realities of the human-animal-biosphere being in constant flux, an understanding which requires an ecological public health analysis of AMR policy development and failure. The paper suggests that effective policy change requires simultaneous actions across policy levels. No single solution is possible, since AMR is the result of long-term human intervention which has accelerated certain trends in the evolution of a microbial ecosystem shared by humans, animals and other biological organisms inhabiting that ecosystem. Viewing the AMR crisis today through an ecological public health lens has the advantage of reuniting the social-ecological and bio-ecological perspectives which have been separated within public health. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Speech recognition employing biologically plausible receptive fields

DEFF Research Database (Denmark)

Fereczkowski, Michal; Bothe, Hans-Heinrich

2011-01-01

spectro-temporal receptive fields to auditory spectrogram input, motivated by the auditory pathway of humans, and ii) the adaptation or learning algorithms involved are biologically inspired. This is in contrast to state-of-the-art combinations of Mel-frequency cepstral coefficients and Hidden Markov...

Introductory biology students' conceptual models and explanations of the origin of variation.

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Speth, Elena Bray; Shaw, Neil; Momsen, Jennifer; Reinagel, Adam; Le, Paul; Taqieddin, Ranya; Long, Tammy

2014-01-01

Mutation is the key molecular mechanism generating phenotypic variation, which is the basis for evolution. In an introductory biology course, we used a model-based pedagogy that enabled students to integrate their understanding of genetics and evolution within multiple case studies. We used student-generated conceptual models to assess understanding of the origin of variation. By midterm, only a small percentage of students articulated complete and accurate representations of the origin of variation in their models. Targeted feedback was offered through activities requiring students to critically evaluate peers' models. At semester's end, a substantial proportion of students significantly improved their representation of how variation arises (though one-third still did not include mutation in their models). Students' written explanations of the origin of variation were mostly consistent with their models, although less effective than models in conveying mechanistic reasoning. This study contributes evidence that articulating the genetic origin of variation is particularly challenging for learners and may require multiple cycles of instruction, assessment, and feedback. To support meaningful learning of the origin of variation, we advocate instruction that explicitly integrates multiple scales of biological organization, assessment that promotes and reveals mechanistic and causal reasoning, and practice with explanatory models with formative feedback. © 2014 E. Bray Speth et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Asian Americans and European Americans' stigma levels in response to biological and social explanations of depression.

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Cheng, Zhen Hadassah

2015-05-01

Mental illness stigma is prevalent among Asian Americans, and it is a key barrier that prevents them from seeking psychological services. Limited studies have experimentally examined how Asian Americans respond to biological and social explanations of mental illness. Understanding how to educate and communicate about mental illness effectively is crucial in increasing service utilization among Asian Americans. To assess how genetic, neurobiological, and social explanations for the onset of depression affects Asian American and European American's mental illness stigma. 231 Asian Americans and 206 European Americans read about an individual with major depression and were randomly assigned to be informed that the cause was either genetic, neurobiological, social, or unknown. Various stigma outcomes, including social distance, fear, and depression duration were assessed. Consistent with prior research, Asian Americans had higher baseline levels of stigma compared to European Americans. Greater social essentialist beliefs predicted positive stigma outcomes for Asian Americans, such as a greater willingness to be near, help, and hire someone with depression, but genetic essentialist beliefs predicted negative stigma outcomes, such as fear. In addition, a social explanation for the etiology of depression led to lower stigma outcomes for Asian Americans; it decreased their fear of someone with depression and increased the perception that depression is treatable. For European Americans, both genetic and social essentialist beliefs predicted a greater perception of depression treatability. Although genetics do play a role in the development of depression, emphasizing a social explanation for the origin of depression may help reduce stigma for Asian Americans.

MRI Proton Density Fat Fraction Is Robust Across the Biologically Plausible Range of Triglyceride Spectra in Adults With Nonalcoholic Steatohepatitis

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Hong, Cheng William; Mamidipalli, Adrija; Hooker, Jonathan C.; Hamilton, Gavin; Wolfson, Tanya; Chen, Dennis H.; Dehkordy, Soudabeh Fazeli; Middleton, Michael S.; Reeder, Scott B.; Loomba, Rohit; Sirlin, Claude B.

2017-01-01

Background Proton density fat fraction (PDFF) estimation requires spectral modeling of the hepatic triglyceride (TG) signal. Deviations in the TG spectrum may occur, leading to bias in PDFF quantification. Purpose To investigate the effects of varying six-peak TG spectral models on PDFF estimation bias. Study Type Retrospective secondary analysis of prospectively acquired clinical research data. Population Forty-four adults with biopsy-confirmed nonalcoholic steatohepatitis. Field Strength/Sequence Confounder-corrected chemical-shift-encoded 3T MRI (using a 2D multiecho gradient-recalled echo technique with magnitude reconstruction) and MR spectroscopy. Assessment In each patient, 61 pairs of colocalized MRI-PDFF and MRS-PDFF values were estimated: one pair used the standard six-peak spectral model, the other 60 were six-peak variants calculated by adjusting spectral model parameters over their biologically plausible ranges. MRI-PDFF values calculated using each variant model and the standard model were compared, and the agreement between MRI-PDFF and MRS-PDFF was assessed. Statistical Tests MRS-PDFF and MRI-PDFF were summarized descriptively. Bland–Altman (BA) analyses were performed between PDFF values calculated using each variant model and the standard model. Linear regressions were performed between BA biases and mean PDFF values for each variant model, and between MRI-PDFF and MRS-PDFF. Results Using the standard model, mean MRS-PDFF of the study population was 17.9±8.0% (range: 4.1–34.3%). The difference between the highest and lowest mean variant MRI-PDFF values was 1.5%. Relative to the standard model, the model with the greatest absolute BA bias overestimated PDFF by 1.2%. Bias increased with increasing PDFF (P hepatic fat content, PDFF estimation is robust across the biologically plausible range of TG spectra. Although absolute estimation bias increased with higher PDFF, its magnitude was small and unlikely to be clinically meaningful. Level of

Generative models versus underlying symmetries to explain biological pattern.

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Frank, S A

2014-06-01

Mathematical models play an increasingly important role in the interpretation of biological experiments. Studies often present a model that generates the observations, connecting hypothesized process to an observed pattern. Such generative models confirm the plausibility of an explanation and make testable hypotheses for further experiments. However, studies rarely consider the broad family of alternative models that match the same observed pattern. The symmetries that define the broad class of matching models are in fact the only aspects of information truly revealed by observed pattern. Commonly observed patterns derive from simple underlying symmetries. This article illustrates the problem by showing the symmetry associated with the observed rate of increase in fitness in a constant environment. That underlying symmetry reveals how each particular generative model defines a single example within the broad class of matching models. Further progress on the relation between pattern and process requires deeper consideration of the underlying symmetries. © 2014 The Author. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Introductory Biology Students’ Conceptual Models and Explanations of the Origin of Variation

Science.gov (United States)

Shaw, Neil; Momsen, Jennifer; Reinagel, Adam; Le, Paul; Taqieddin, Ranya; Long, Tammy

2014-01-01

Mutation is the key molecular mechanism generating phenotypic variation, which is the basis for evolution. In an introductory biology course, we used a model-based pedagogy that enabled students to integrate their understanding of genetics and evolution within multiple case studies. We used student-generated conceptual models to assess understanding of the origin of variation. By midterm, only a small percentage of students articulated complete and accurate representations of the origin of variation in their models. Targeted feedback was offered through activities requiring students to critically evaluate peers’ models. At semester's end, a substantial proportion of students significantly improved their representation of how variation arises (though one-third still did not include mutation in their models). Students’ written explanations of the origin of variation were mostly consistent with their models, although less effective than models in conveying mechanistic reasoning. This study contributes evidence that articulating the genetic origin of variation is particularly challenging for learners and may require multiple cycles of instruction, assessment, and feedback. To support meaningful learning of the origin of variation, we advocate instruction that explicitly integrates multiple scales of biological organization, assessment that promotes and reveals mechanistic and causal reasoning, and practice with explanatory models with formative feedback. PMID:25185235

Students' reasons for preferring teleological explanations

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Trommler, Friederike; Gresch, Helge; Hammann, Marcus

2018-01-01

The teleological bias, a major learning obstacle, involves explaining biological phenomena in terms of purposes and goals. To probe the teleological bias, researchers have used acceptance judgement tasks and preference judgement tasks. In the present study, such tasks were used with German high school students (N = 353) for 10 phenomena from human biology, that were explained both teleologically and causally. A sub-sample (n = 26) was interviewed about the reasons for their preferences. The results showed that the students favoured teleological explanations over causal explanations. Although the students explained their preference judgements etiologically (i.e. teleologically and causally), they also referred to a wide range of non-etiological criteria (i.e. familiarity, complexity, relevance and five more criteria). When elaborating on their preference for causal explanations, the students often focused not on the causality of the phenomenon, but on mechanisms whose complexity they found attractive. When explaining their preference for teleological explanations, they often focused not teleologically on purposes and goals, but rather on functions, which they found familiar and relevant. Generally, students' preference judgements rarely allowed for making inferences about causal reasoning and teleological reasoning, an issue that is controversial in the literature. Given that students were largely unaware of causality and teleology, their attention must be directed towards distinguishing between etiological and non-etiological reasoning. Implications for educational practice as well as for future research are discussed.

Bisimulation for Single-Agent Plausibility Models

DEFF Research Database (Denmark)

Andersen, Mikkel Birkegaard; Bolander, Thomas; van Ditmarsch, H.

2013-01-01

define a proper notion of bisimulation, and prove that bisimulation corresponds to logical equivalence on image-finite models. We relate our results to other epistemic notions, such as safe belief and degrees of belief. Our results imply that there are only finitely many non-bisimilar single......-agent epistemic plausibility models on a finite set of propositions. This gives decidability for single-agent epistemic plausibility planning....

Transforming Biology Assessment with Machine Learning: Automated Scoring of Written Evolutionary Explanations

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Nehm, Ross H.; Ha, Minsu; Mayfield, Elijah

2012-01-01

This study explored the use of machine learning to automatically evaluate the accuracy of students' written explanations of evolutionary change. Performance of the Summarization Integrated Development Environment (SIDE) program was compared to human expert scoring using a corpus of 2,260 evolutionary explanations written by 565 undergraduate…

Explanations - Styles of explanation in science

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Cornwell, John

2004-06-01

Our lives, states of health, relationships, behavior, experiences of the natural world, and the technologies that shape our contemporary existence are subject to a superfluity of competing, multi-faceted and sometimes incompatible explanations. Widespread confusion about the nature of "explanation" and its scope and limits pervades popular exposition of the natural sciences, popular history and philosophy of science. This fascinating book explores the way explanations work, why they vary between disciplines, periods, and cultures, and whether they have any necessary boundaries. In other words, Explanations aims to achieve a better understanding of explanation, both within the sciences and the humanities. It features contributions from expert writers from a wide range of disciplines, including science, philosophy, mathematics, and social anthropology.

Top-down models in biology: explanation and control of complex living systems above the molecular level.

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Pezzulo, Giovanni; Levin, Michael

2016-11-01

It is widely assumed in developmental biology and bioengineering that optimal understanding and control of complex living systems follows from models of molecular events. The success of reductionism has overshadowed attempts at top-down models and control policies in biological systems. However, other fields, including physics, engineering and neuroscience, have successfully used the explanations and models at higher levels of organization, including least-action principles in physics and control-theoretic models in computational neuroscience. Exploiting the dynamic regulation of pattern formation in embryogenesis and regeneration requires new approaches to understand how cells cooperate towards large-scale anatomical goal states. Here, we argue that top-down models of pattern homeostasis serve as proof of principle for extending the current paradigm beyond emergence and molecule-level rules. We define top-down control in a biological context, discuss the examples of how cognitive neuroscience and physics exploit these strategies, and illustrate areas in which they may offer significant advantages as complements to the mainstream paradigm. By targeting system controls at multiple levels of organization and demystifying goal-directed (cybernetic) processes, top-down strategies represent a roadmap for using the deep insights of other fields for transformative advances in regenerative medicine and systems bioengineering. © 2016 The Author(s).

Research traditions and evolutionary explanations in medicine.

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Méthot, Pierre-Olivier

2011-02-01

In this article, I argue that distinguishing 'evolutionary' from 'Darwinian' medicine will help us assess the variety of roles that evolutionary explanations can play in a number of medical contexts. Because the boundaries of evolutionary and Darwinian medicine overlap to some extent, however, they are best described as distinct 'research traditions' rather than as competing paradigms. But while evolutionary medicine does not stand out as a new scientific field of its own, Darwinian medicine is united by a number of distinctive theoretical and methodological claims. For example, evolutionary medicine and Darwinian medicine can be distinguished with respect to the styles of evolutionary explanations they employ. While the former primarily involves 'forward looking' explanations, the latter depends mostly on 'backward looking' explanations. A forward looking explanation tries to predict the effects of ongoing evolutionary processes on human health and disease in contemporary environments (e.g., hospitals). In contrast, a backward looking explanation typically applies evolutionary principles from the vantage point of humans' distant biological past in order to assess present states of health and disease. Both approaches, however, are concerned with the prevention and control of human diseases. In conclusion, I raise some concerns about the claim that 'nothing in medicine makes sense except in the light of evolution'.

What was historical about natural history? Contingency and explanation in the science of living things.

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Harrison, Peter

2016-08-01

There is a long-standing distinction in Western thought between scientific and historical modes of explanation. According to Aristotle's influential account of scientific knowledge there cannot be an explanatory science of what is contingent and accidental, such things being the purview of a descriptive history. This distinction between scientia and historia continued to inform assumptions about scientific explanation into the nineteenth century and is particularly significant when considering the emergence of biology and its displacement of the more traditional discipline of natural history. One of the consequences of this nineteenth-century transition was that while modern evolutionary theory retained significant, if often implicit, historical components, these were often overlooked as evolutionary biology sought to accommodate itself to a model of scientific explanation that involved appeals to laws of nature. These scientific aspirations of evolutionary biology sometimes sit uncomfortably with its historical dimension. This tension lies beneath recent philosophical critiques of evolutionary theory and its modes of explanation. Such critiques, however, overlook the fact that there are legitimate modes of historical explanation that do not require recourse to laws of nature. But responding to these criticisms calls for a more explicit recognition of the affinities between evolutionary biology and history. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Age and the Explanation of Crime, Revisited

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Sweeten, Gary; Piquero, Alex R.; Steinberg, Laurence

2013-01-01

Age is one of the most robust correlates of criminal behavior. Yet, explanations for this relationship are varied and conflicting. Developmental theories point to a multitude of sociological, psychological, and biological changes that occur during adolescence and adulthood. One prominent criminological perspective outlined by Gottfredson and…

A biologically plausible transform for visual recognition that is invariant to translation, scale and rotation

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Pavel eSountsov

2011-11-01

Full Text Available Visual object recognition occurs easily despite differences in position, size, and rotation of the object, but the neural mechanisms responsible for this invariance are not known. We have found a set of transforms that achieve invariance in a neurally plausible way. We find that a transform based on local spatial frequency analysis of oriented segments and on logarithmic mapping, when applied twice in an iterative fashion, produces an output image that is unique to the object and that remains constant as the input image is shifted, scaled or rotated.

A Biologically Plausible Transform for Visual Recognition that is Invariant to Translation, Scale, and Rotation.

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Sountsov, Pavel; Santucci, David M; Lisman, John E

2011-01-01

Visual object recognition occurs easily despite differences in position, size, and rotation of the object, but the neural mechanisms responsible for this invariance are not known. We have found a set of transforms that achieve invariance in a neurally plausible way. We find that a transform based on local spatial frequency analysis of oriented segments and on logarithmic mapping, when applied twice in an iterative fashion, produces an output image that is unique to the object and that remains constant as the input image is shifted, scaled, or rotated.

Pilgrims sailing the Titanic: plausibility effects on memory for misinformation.

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Hinze, Scott R; Slaten, Daniel G; Horton, William S; Jenkins, Ryan; Rapp, David N

2014-02-01

People rely on information they read even when it is inaccurate (Marsh, Meade, & Roediger, Journal of Memory and Language 49:519-536, 2003), but how ubiquitous is this phenomenon? In two experiments, we investigated whether this tendency to encode and rely on inaccuracies from text might be influenced by the plausibility of misinformation. In Experiment 1, we presented stories containing inaccurate plausible statements (e.g., "The Pilgrims' ship was the Godspeed"), inaccurate implausible statements (e.g., . . . the Titanic), or accurate statements (e.g., . . . the Mayflower). On a subsequent test of general knowledge, participants relied significantly less on implausible than on plausible inaccuracies from the texts but continued to rely on accurate information. In Experiment 2, we replicated these results with the addition of a think-aloud procedure to elicit information about readers' noticing and evaluative processes for plausible and implausible misinformation. Participants indicated more skepticism and less acceptance of implausible than of plausible inaccuracies. In contrast, they often failed to notice, completely ignored, and at times even explicitly accepted the misinformation provided by plausible lures. These results offer insight into the conditions under which reliance on inaccurate information occurs and suggest potential mechanisms that may underlie reported misinformation effects.

Eliciting explanations: Constraints on when self-explanation aids learning.

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Rittle-Johnson, Bethany; Loehr, Abbey M

2017-10-01

Generating explanations for oneself in an attempt to make sense of new information (i.e., self-explanation) is often a powerful learning technique. Despite its general effectiveness, in a growing number of studies, prompting for self-explanation improved some aspects of learning, but reduced learning of other aspects. Drawing on this recent research, as well as on research comparing self-explanation under different conditions, we propose four constraints on the effectiveness of self-explanation. First, self-explanation promotes attention to particular types of information, so it is better suited to promote particular learning outcomes in particular types of domains, such as transfer in domains guided by general principles or heuristics. Second, self-explaining a variety of types of information can improve learning, but explaining one's own solution methods or choices may reduce learning under certain conditions. Third, explanation prompts focus effort on particular aspects of the to-be-learned material, potentially drawing effort away from other important information. Explanation prompts must be carefully designed to align with target learning outcomes. Fourth, prompted self-explanation often promotes learning better than unguided studying, but alternative instructional techniques may be more effective under some conditions. Attention to these constraints should optimize the effectiveness of self-explanation as an instructional technique in future research and practice.

Constructing Scientific Explanations: a System of Analysis for Students' Explanations

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de Andrade, Vanessa; Freire, Sofia; Baptista, Mónica

2017-08-01

This article describes a system of analysis aimed at characterizing students' scientific explanations. Science education literature and reform documents have been highlighting the importance of scientific explanations for students' conceptual understanding and for their understanding of the nature of scientific knowledge. Nevertheless, and despite general agreement regarding the potential of having students construct their own explanations, a consensual notion of scientific explanation has still not been reached. As a result, within science education literature, there are several frameworks defining scientific explanations, with different foci as well as different notions of what accounts as a good explanation. Considering this, and based on a more ample project, we developed a system of analysis to characterize students' explanations. It was conceptualized and developed based on theories and models of scientific explanations, science education literature, and from examples of students' explanations collected by an open-ended questionnaire. With this paper, it is our goal to present the system of analysis, illustrating it with specific examples of students' collected explanations. In addition, we expect to point out its adequacy and utility for analyzing and characterizing students' scientific explanations as well as for tracing their progression.

Plausibility and evidence: the case of homeopathy.

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Rutten, Lex; Mathie, Robert T; Fisher, Peter; Goossens, Maria; van Wassenhoven, Michel

2013-08-01

Homeopathy is controversial and hotly debated. The conclusions of systematic reviews of randomised controlled trials of homeopathy vary from 'comparable to conventional medicine' to 'no evidence of effects beyond placebo'. It is claimed that homeopathy conflicts with scientific laws and that homoeopaths reject the naturalistic outlook, but no evidence has been cited. We are homeopathic physicians and researchers who do not reject the scientific outlook; we believe that examination of the prior beliefs underlying this enduring stand-off can advance the debate. We show that interpretations of the same set of evidence--for homeopathy and for conventional medicine--can diverge. Prior disbelief in homeopathy is rooted in the perceived implausibility of any conceivable mechanism of action. Using the 'crossword analogy', we demonstrate that plausibility bias impedes assessment of the clinical evidence. Sweeping statements about the scientific impossibility of homeopathy are themselves unscientific: scientific statements must be precise and testable. There is growing evidence that homeopathic preparations can exert biological effects; due consideration of such research would reduce the influence of prior beliefs on the assessment of systematic review evidence.

Heuristic Elements of Plausible Reasoning.

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Dudczak, Craig A.

At least some of the reasoning processes involved in argumentation rely on inferences which do not fit within the traditional categories of inductive or deductive reasoning. The reasoning processes involved in plausibility judgments have neither the formal certainty of deduction nor the imputed statistical probability of induction. When utilizing…

The use of theoretical and empirical knowledge in the production of explanations and arguments in an inquiry biology activity

Directory of Open Access Journals (Sweden)

Maíra Batistoni e Silva

2017-08-01

Full Text Available Agreeing with the scientific literacy as the purpose of science education and with the recent propositions that in order to achieve it we should favor the engagement of students in practices of scientific culture, this study intends to analyze the production of explanations and arguments in an inquiry based teaching activity in order to characterize students' mobilization of theoretical and empirical knowledge by engaging in these practices. Analyzing the scientific reports elaborated by the students (14-15 years old after the inquiry activity on population dynamics, we highlight the importance of empirical knowledge about the experimental context as a repertoire for construction of explanations, especially when students deal with anomalous data. This knowledge was also important for production of valid arguments, since most of the justifications were empirical, regardless of whether or not the data were in accordance with the explanatory model already known. These results reinforce the importance of students' engagement in inquiry activities, as already defended by different authors of this research area, and indicate that the inquiry practice allowed the engagement in epistemic practices, since the knowledge about the experimental conditions and the procedures of data collection provided a repertoire for the production of explanations and arguments. Finally, we discuss the relevance of this research to the field of biology teaching, seeking to defend the promotion of inquiry activities with an experimental approach as an opportunity to integrate conceptual and epistemic objectives and overcome the difficulties generated by the specificities of this area of knowledge in relation to the other disciplines in nature sciences.

Plausible values in statistical inference

NARCIS (Netherlands)

Marsman, M.

2014-01-01

In Chapter 2 it is shown that the marginal distribution of plausible values is a consistent estimator of the true latent variable distribution, and, furthermore, that convergence is monotone in an embedding in which the number of items tends to infinity. This result is used to clarify some of the

Pluralism, Pragmatism and Functional Explanations

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Shaw Jamie

2016-04-01

Full Text Available While many philosophers speak of ‘pluralism’ within philosophy of biology, there has been little said about what such pluralism amounts to or what its underlying assumptions are. This has provoked so me anxiety about whether pluralism is compatible with their commitment to naturalism (Cussins 1992. This paper surveys three prominent pluralist positions (Sandra Mitchell and Michael Dietrich’s (2006 ‘integrative pluralism’, and both Peter Godfrey-Smith’s (1993 and Beth Preston’s (1998 pluralist analyses of functional explanations in evolutionary biology and demonstrates how all three are committed to a form of pragmatism. This analysis both clarifies the justification and grounding of pluralism and allows these pluralisms to avoid the criticisms of Cussins. I close by making some more general points about pluralism and its relationship to history and integration.

Explanation and inference: Mechanistic and functional explanations guide property generalization

Directory of Open Access Journals (Sweden)

Tania eLombrozo

2014-09-01

Full Text Available The ability to generalize from the known to the unknown is central to learning and inference. Two experiments explore the relationship between how a property is explained and how that property is generalized to novel species and artifacts. The experiments contrast the consequences of explaining a property mechanistically, by appeal to parts and processes, with the consequences of explaining the property functionally, by appeal to functions and goals. The findings suggest that properties that are explained functionally are more likely to be generalized on the basis of shared functions, with a weaker relationship between mechanistic explanations and generalization on the basis of shared parts and processes. The influence of explanation type on generalization holds even though all participants are provided with the same mechanistic and functional information, and whether an explanation type is freely generated (Experiment 1, experimentally provided (Experiment 2, or experimentally induced (Experiment 2. The experiments also demonstrate that explanations and generalizations of a particular type (mechanistic or functional can be experimentally induced by providing sample explanations of that type, with a comparable effect when the sample explanations come from the same domain or from a different domains. These results suggest that explanations serve as a guide to generalization, and contribute to a growing body of work supporting the value of distinguishing mechanistic and functional explanations.

Explanation and inference: mechanistic and functional explanations guide property generalization.

Science.gov (United States)

Lombrozo, Tania; Gwynne, Nicholas Z

2014-01-01

The ability to generalize from the known to the unknown is central to learning and inference. Two experiments explore the relationship between how a property is explained and how that property is generalized to novel species and artifacts. The experiments contrast the consequences of explaining a property mechanistically, by appeal to parts and processes, with the consequences of explaining the property functionally, by appeal to functions and goals. The findings suggest that properties that are explained functionally are more likely to be generalized on the basis of shared functions, with a weaker relationship between mechanistic explanations and generalization on the basis of shared parts and processes. The influence of explanation type on generalization holds even though all participants are provided with the same mechanistic and functional information, and whether an explanation type is freely generated (Experiment 1), experimentally provided (Experiment 2), or experimentally induced (Experiment 2). The experiments also demonstrate that explanations and generalizations of a particular type (mechanistic or functional) can be experimentally induced by providing sample explanations of that type, with a comparable effect when the sample explanations come from the same domain or from a different domains. These results suggest that explanations serve as a guide to generalization, and contribute to a growing body of work supporting the value of distinguishing mechanistic and functional explanations.

Dual Causality and the Autonomy of Biology.

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Bock, Walter J

2017-03-01

Ernst Mayr's concept of dual causality in biology with the two forms of causes (proximate and ultimate) continues to provide an essential foundation for the philosophy of biology. They are equivalent to functional (=proximate) and evolutionary (=ultimate) causes with both required for full biological explanations. The natural sciences can be classified into nomological, historical nomological and historical dual causality, the last including only biology. Because evolutionary causality is unique to biology and must be included for all complete biological explanations, biology is autonomous from the physical sciences.

The coexistence of natural and supernatural explanations within and across domains and development.

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Busch, Justin T A; Watson-Jones, Rachel E; Legare, Cristine H

2017-03-01

People across highly diverse cultural contexts use both natural and supernatural explanations to explain questions of fundamental concern such as death, illness, and human origins. The present study examines the development of explanatory coexistence within and across domains of existential concern in individuals in Tanna, Vanuatu. We examined three age groups: 7- to 12-year-old children, 13- to 18-year-old adolescents, and 19- to 70-year-old adults (N = 72). Within the domain of death, biological and spontaneous explanations were most common across all ages. For illness, children showed the highest rates of explanatory coexistence, while adolescents and adults favoured biological explanations. Within the human origins domain, theistic explanations were most common across the age groups. Overall, these data show that coexistence reasoning in these domains is pervasive across cultures, yet at the same time it is deeply contextually specific, reflecting the nuanced differences in local ecologies and cultural beliefs. Statement of contribution What is already known on this subject? Individuals across highly diverse cultural contexts use both natural and supernatural explanations to understand the events that occur in their lives. Context and cultural input play a large role in determining when and how individuals incorporate natural and supernatural explanations. The development of explanatory coexistence has primarily studied explanations for isolated domains. What does this study add? We examined explanatory coexistence in a culture with recent conversion to Christianity and formal education. The current research examines how individuals reason within and across the domains of human origins, illness, and death. Developmental differences associated with explanatory coexistence are examined. © 2016 The British Psychological Society.

Anatomically Plausible Surface Alignment and Reconstruction

DEFF Research Database (Denmark)

Paulsen, Rasmus R.; Larsen, Rasmus

2010-01-01

With the increasing clinical use of 3D surface scanners, there is a need for accurate and reliable algorithms that can produce anatomically plausible surfaces. In this paper, a combined method for surface alignment and reconstruction is proposed. It is based on an implicit surface representation...

Stereotyping to infer group membership creates plausible deniability for prejudice-based aggression.

Science.gov (United States)

Cox, William T L; Devine, Patricia G

2014-02-01

In the present study, participants administered painful electric shocks to an unseen male opponent who was either explicitly labeled as gay or stereotypically implied to be gay. Identifying the opponent with a gay-stereotypic attribute produced a situation in which the target's group status was privately inferred but plausibly deniable to others. To test the plausible deniability hypothesis, we examined aggression levels as a function of internal (personal) and external (social) motivation to respond without prejudice. Whether plausible deniability was present or absent, participants high in internal motivation aggressed at low levels, and participants low in both internal and external motivation aggressed at high levels. The behavior of participants low in internal and high in external motivation, however, depended on experimental condition. They aggressed at low levels when observers could plausibly attribute their behavior to prejudice and aggressed at high levels when the situation granted plausible deniability. This work has implications for both obstacles to and potential avenues for prejudice-reduction efforts.

Application of plausible reasoning to AI-based control systems

Science.gov (United States)

Berenji, Hamid; Lum, Henry, Jr.

1987-01-01

Some current approaches to plausible reasoning in artificial intelligence are reviewed and discussed. Some of the most significant recent advances in plausible and approximate reasoning are examined. A synergism among the techniques of uncertainty management is advocated, and brief discussions on the certainty factor approach, probabilistic approach, Dempster-Shafer theory of evidence, possibility theory, linguistic variables, and fuzzy control are presented. Some extensions to these methods are described, and the applications of the methods are considered.

Credibility judgments of narratives: language, plausibility, and absorption.

Science.gov (United States)

Nahari, Galit; Glicksohn, Joseph; Nachson, Israel

2010-01-01

Two experiments were conducted in order to find out whether textual features of narratives differentially affect credibility judgments made by judges having different levels of absorption (a disposition associated with rich visual imagination). Participants in both experiments were exposed to a textual narrative and requested to judge whether the narrator actually experienced the event he described in his story. In Experiment 1, the narrative varied in terms of language (literal, figurative) and plausibility (ordinary, anomalous). In Experiment 2, the narrative varied in terms of language only. The participants' perceptions of the plausibility of the story described and the extent to which they were absorbed in reading were measured. The data from both experiments together suggest that the groups applied entirely different criteria in credibility judgments. For high-absorption individuals, their credibility judgment depends on the degree to which the text can be assimilated into their own vivid imagination, whereas for low-absorption individuals it depends mainly on plausibility. That is, high-absorption individuals applied an experiential mental set while judging the credibility of the narrator, whereas low-absorption individuals applied an instrumental mental set. Possible cognitive mechanisms and implications for credibility judgments are discussed.

Searching for Plausible N-k Contingencies Endangering Voltage Stability

DEFF Research Database (Denmark)

Weckesser, Johannes Tilman Gabriel; Van Cutsem, Thierry

2017-01-01

This paper presents a novel search algorithm using time-domain simulations to identify plausible N − k contingencies endangering voltage stability. Starting from an initial list of disturbances, progressively more severe contingencies are investigated. After simulation of a N − k contingency......, the simulation results are assessed. If the system response is unstable, a plausible harmful contingency sequence has been found. Otherwise, components affected by the contingencies are considered as candidate next event leading to N − (k + 1) contingencies. This implicitly takes into account hidden failures...

The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence From Word Segmentation.

Science.gov (United States)

Phillips, Lawrence; Pearl, Lisa

2015-11-01

The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's cognitive plausibility. We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition model can aim to be cognitively plausible in multiple ways. We discuss these cognitive plausibility checkpoints generally and then apply them to a case study in word segmentation, investigating a promising Bayesian segmentation strategy. We incorporate cognitive plausibility by using an age-appropriate unit of perceptual representation, evaluating the model output in terms of its utility, and incorporating cognitive constraints into the inference process. Our more cognitively plausible model shows a beneficial effect of cognitive constraints on segmentation performance. One interpretation of this effect is as a synergy between the naive theories of language structure that infants may have and the cognitive constraints that limit the fidelity of their inference processes, where less accurate inference approximations are better when the underlying assumptions about how words are generated are less accurate. More generally, these results highlight the utility of incorporating cognitive plausibility more fully into computational models of language acquisition. Copyright © 2015 Cognitive Science Society, Inc.

Transforming Biology Assessment with Machine Learning: Automated Scoring of Written Evolutionary Explanations

Science.gov (United States)

Nehm, Ross H.; Ha, Minsu; Mayfield, Elijah

2012-02-01

This study explored the use of machine learning to automatically evaluate the accuracy of students' written explanations of evolutionary change. Performance of the Summarization Integrated Development Environment (SIDE) program was compared to human expert scoring using a corpus of 2,260 evolutionary explanations written by 565 undergraduate students in response to two different evolution instruments (the EGALT-F and EGALT-P) that contained prompts that differed in various surface features (such as species and traits). We tested human-SIDE scoring correspondence under a series of different training and testing conditions, using Kappa inter-rater agreement values of greater than 0.80 as a performance benchmark. In addition, we examined the effects of response length on scoring success; that is, whether SIDE scoring models functioned with comparable success on short and long responses. We found that SIDE performance was most effective when scoring models were built and tested at the individual item level and that performance degraded when suites of items or entire instruments were used to build and test scoring models. Overall, SIDE was found to be a powerful and cost-effective tool for assessing student knowledge and performance in a complex science domain.

Experimental Philosophy of Explanation Rising: The Case for a Plurality of Concepts of Explanation.

Science.gov (United States)

Colombo, Matteo

2017-03-01

This paper brings together results from the philosophy and the psychology of explanation to argue that there are multiple concepts of explanation in human psychology. Specifically, it is shown that pluralism about explanation coheres with the multiplicity of models of explanation available in the philosophy of science, and it is supported by evidence from the psychology of explanatory judgment. Focusing on the case of a norm of explanatory power, the paper concludes by responding to the worry that if there is a plurality of concepts of explanation, one will not be able to normatively evaluate what counts as good explanation. Copyright © 2016 Cognitive Science Society, Inc.

Analogy, explanation, and proof

Science.gov (United States)

Hummel, John E.; Licato, John; Bringsjord, Selmer

2014-01-01

People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence. PMID:25414655

Analogy, Explanation, and Proof

Directory of Open Access Journals (Sweden)

John eHummel

2014-11-01

Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

Synthetic biology: a challenge to mechanical explanations in biology?

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Morange, Michel

2012-01-01

In their plans to modify organisms, synthetic biologists have contrasted engineering and tinkering. By drawing this contrast between their endeavors and what has happened during the evolution of organisms by natural selection, they underline the novelty of their projects and justify their ambitions. Synthetic biologists are at odds with a long tradition that has considered organisms as "perfect machines." This tradition had already been questioned by Stephen Jay Gould in the 1970s and received a major blow with the comparison made by François Jacob between organisms and the results of "bricolage" (tinkering). These contrasts between engineering and tinkering, synthetic biology and evolution, have no raison d'être. Machines built by humans are increasingly inspired by observations made on organisms. This is not a simple reversal of the previous trend-the mechanical conception of organisms-in which the characteristics of the latter were explained by comparison with human-built machines. Relations between organisms and machines have always been complex and ambiguous.

Evolutionary explanations in medical and health profession courses: are you answering your students' "why" questions?

Directory of Open Access Journals (Sweden)

Malyango Avelin A

2005-05-01

Full Text Available Abstract Background Medical and pre-professional health students ask questions about human health that can be answered in two ways, by giving proximate and evolutionary explanations. Proximate explanations, most common in textbooks and classes, describe the immediate scientifically known biological mechanisms of anatomical characteristics or physiological processes. These explanations are necessary but insufficient. They can be complemented with evolutionary explanations that describe the evolutionary processes and principles that have resulted in human biology we study today. The main goal of the science of Darwinian Medicine is to investigate human disease, disorders, and medical complications from an evolutionary perspective. Discussion This paper contrasts the differences between these two types of explanations by describing principles of natural selection that underlie medical questions. Thus, why is human birth complicated? Why does sickle cell anemia exist? Why do we show symptoms like fever, diarrhea, and coughing when we have infection? Why do we suffer from ubiquitous age-related diseases like arteriosclerosis, Alzheimer's and others? Why are chronic diseases like type II diabetes and obesity so prevalent in modern society? Why hasn't natural selection eliminated the genes that cause common genetic diseases like hemochromatosis, cystic fibrosis, Tay sachs, PKU and others? Summary In giving students evolutionary explanations professors should underscore principles of natural selection, since these can be generalized for the analysis of many medical questions. From a research perspective, natural selection seems central to leading hypotheses of obesity and type II diabetes and might very well explain the occurrence of certain common genetic diseases like cystic fibrosis, hemochromatosis, Tay sachs, Fragile X syndrome, G6PD and others because of their compensating advantages. Furthermore, armed with evolutionary explanations, health care

Creating visual explanations improves learning.

Science.gov (United States)

Bobek, Eliza; Tversky, Barbara

2016-01-01

Many topics in science are notoriously difficult for students to learn. Mechanisms and processes outside student experience present particular challenges. While instruction typically involves visualizations, students usually explain in words. Because visual explanations can show parts and processes of complex systems directly, creating them should have benefits beyond creating verbal explanations. We compared learning from creating visual or verbal explanations for two STEM domains, a mechanical system (bicycle pump) and a chemical system (bonding). Both kinds of explanations were analyzed for content and learning assess by a post-test. For the mechanical system, creating a visual explanation increased understanding particularly for participants of low spatial ability. For the chemical system, creating both visual and verbal explanations improved learning without new teaching. Creating a visual explanation was superior and benefitted participants of both high and low spatial ability. Visual explanations often included crucial yet invisible features. The greater effectiveness of visual explanations appears attributable to the checks they provide for completeness and coherence as well as to their roles as platforms for inference. The benefits should generalize to other domains like the social sciences, history, and archeology where important information can be visualized. Together, the findings provide support for the use of learner-generated visual explanations as a powerful learning tool.

Gut Microbiome and Obesity: A Plausible Explanation for Obesity.

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Sanmiguel, Claudia; Gupta, Arpana; Mayer, Emeran A

2015-06-01

Obesity is a multifactorial disorder that results in excessive accumulation of adipose tissue. Although obesity is caused by alterations in the energy consumption/expenditure balance, the factors promoting this disequilibrium are incompletely understood. The rapid development of new technologies and analysis strategies to decode the gut microbiota composition and metabolic pathways has opened a door into the complexity of the guest-host interactions between the gut microbiota and its human host in health and in disease. Pivotal studies have demonstrated that manipulation of the gut microbiota and its metabolic pathways can affect host's adiposity and metabolism. These observations have paved the way for further assessment of the mechanisms underlying these changes. In this review we summarize the current evidence for possible mechanisms underlying gut microbiota induced obesity. The review addresses some well-known effects of the gut microbiota on energy harvesting and changes in metabolic machinery, on metabolic and immune interactions and on possible changes in brain function and behavior. Although there is limited understanding on the symbiotic relationship between us and our gut microbiome, and how disturbances of this relationship affects our health, there is compelling evidence for an important role of the gut microbiota in the development and perpetuation of obesity.

Gut Microbiome and Obesity: A Plausible Explanation for Obesity

Science.gov (United States)

Sanmiguel, Claudia; Gupta, Arpana; Mayer, Emeran A.

2015-01-01

Obesity is a multifactorial disorder that results in excessive accumulation of adipose tissue. Although obesity is caused by alterations in the energy consumption/expenditure balance, the factors promoting this disequilibrium are incompletely understood. The rapid development of new technologies and analysis strategies to decode the gut microbiota composition and metabolic pathways has opened a door into the complexity of the guest-host interactions between the gut microbiota and its human host in health and in disease. Pivotal studies have demonstrated that manipulation of the gut microbiota and its metabolic pathways can affect host’s adiposity and metabolism. These observations have paved the way for further assessment of the mechanisms underlying these changes. In this review we summarize the current evidence for possible mechanisms underlying gut microbiota induced obesity. The review addresses some well-known effects of the gut microbiota on energy harvesting and changes in metabolic machinery, on metabolic and immune interactions and on possible changes in brain function and behavior. Although there is limited understanding on the symbiotic relationship between us and our gut microbiome, and how disturbances of this relationship affects our health, there is compelling evidence for an important role of the gut microbiota in the development and perpetuation of obesity. PMID:26029487

Endocrine distrupting chemicals and human health: The plausibility ...

African Journals Online (AJOL)

The plausibility of research results on DDT and reproductive health ... cals in the environment and that human health is inextri- cably linked to the health of .... periods of folliculo-genesis or embryo-genesis that increases risk for adverse effects.

Examining elementary teachers' knowledge and instruction of scientific explanations for fostering children's explanations in science

Science.gov (United States)

Wiebke, Heidi Lynn

This study employed an embedded mixed methods multi-case study design (Creswell, 2014) with six early childhood (grades K-2) teachers to examine a) what changes occurred to their subject matter knowledge (SMK) and pedagogical content knowledge (PCK) for teaching scientific explanations while participating in a professional development program, b) how they planned for and implemented scientific explanation instruction within a teacher developed unit on properties of matter, and c) what affordances their instruction of scientific explanations had on fostering their students' abilities to generate explanations in science. Several quantitative and qualitative measures were collected and analyzed in accordance to this studies conceptual framework, which consisted of ten instructional practices teachers should consider assimilating or accommodating into their knowledge base (i.e., SMK & PCK) for teaching scientific explanations. Results of this study indicate there was little to no positive change in the teachers' substantive and syntactic SMK. However, all six teachers did make significant changes to all five components of their PCK for teaching explanations in science. While planning for scientific explanation instruction, all six teachers' contributed some ideas for how to incorporate seven of the ten instructional practices for scientific explanations within the properties of matter unit they co-developed. When enacting the unit, the six teachers' employed seven to nine of the instructional practices to varying levels of effectiveness, as measured by researcher developed rubrics. Given the six teachers' scientific explanation instruction, many students did show improvement in their ability to formulate a scientific explanation, particularly their ability to provide multiple pieces of evidence. Implications for professional developers, teacher educators, researchers, policy makers, and elementary teachers regarding how to prepare teachers for and support students

The logic of counterfactual analysis in case-study explanation.

Science.gov (United States)

Mahoney, James; Barrenechea, Rodrigo

2017-12-19

In this paper, we develop a set-theoretic and possible worlds approach to counterfactual analysis in case-study explanation. Using this approach, we first consider four kinds of counterfactuals: necessary condition counterfactuals, SUIN condition counterfactuals, sufficient condition counterfactuals, and INUS condition counterfactuals. We explore the distinctive causal claims entailed in each, and conclude that necessary condition and SUIN condition counterfactuals are the most useful types for hypothesis assessment in case-study research. We then turn attention to the development of a rigorous understanding of the 'minimal-rewrite' rule, linking this rule to insights from set theory about the relative importance of necessary conditions. We show why, logically speaking, a comparative analysis of two necessary condition counterfactuals will tend to favour small events and contingent happenings. A third section then presents new tools for specifying the level of generality of the events in a counterfactual. We show why and how the goals of formulating empirically important versus empirically plausible counterfactuals stand in tension with one another. Finally, we use our framework to link counterfactual analysis to causal sequences, which in turn provides advantages for conducting counterfactual projections. © London School of Economics and Political Science 2017.

A Model of How Different Biology Experts Explain Molecular and Cellular Mechanisms

Science.gov (United States)

Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

2015-01-01

Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do explanations made by experts from different biology subdisciplines at a university support the validity of this model? Guided by the modeling framework of R. S. Justi and J. K. Gilbert, the validity of an initial model was tested by asking seven biologists to explain a molecular mechanism of their choice. Data were collected from interviews, artifacts, and drawings, and then subjected to thematic analysis. We found that biologists explained the specific activities and organization of entities of the mechanism. In addition, they contextualized explanations according to their biological and social significance; integrated explanations with methods, instruments, and measurements; and used analogies and narrated stories. The derived methods, analogies, context, and how themes informed the development of our final MACH model of mechanistic explanations. Future research will test the potential of the MACH model as a guiding framework for instruction to enhance the quality of student explanations. PMID:25999313

Evolutionary explanations in medicine: how do they differ and how to benefit from them.

Science.gov (United States)

Lozano, George A

2010-04-01

Evolutionary explanations, many of which have appeared on the pages of this journal, are becoming more pervasive and influential in medicine, so it is becoming more important to understand how these types of explanations differ from the proximate approach that is more common in medicine, and how the evolutionary approach can contribute to medicine. Understanding of any biological phenomenon can occur at four levels: (1) ontogeny (2) causation, (3) function and (4) evolution. These approaches are not mutually exclusive, and whereas the first two are more common in medical practice, a complete explanation requires all four levels of analysis. Two major differences among these approaches are the apparent degree of immediacy associated with them, and the extent to which they apply to individuals rather than populations. Criticisms of adaptive explanations often arise from a failure to understand the complementary nature of these four types of explanations. Other unwarranted criticisms result from a failure to appreciate that adaptive explanations often apply to populations, not individuals. A third type of criticism is driven by the mistaken belief that adaptive explanations somehow justify morally reprehensible behaviours. Finally, evolutionary explanations sometimes face the criticism of "personal incredulity". Adaptive explanations must be consistent with basic evolutionary concepts and must adhere to the physical reality of the phenomenon in question. Their value, however, comes not in devising a seemingly rational explanation, but in their predictions. Testable predictions must be explicitly stated and clearly articulated. They must differ from those of arising from other hypotheses and must not only be interesting to evolutionary biologists, but also useful to medical practitioners. Integration of the proximate and the ultimate approaches is possible and potentially beneficial to both evolutionists and physicians, but it requires some basic understanding of our

Kinds and problems of geomorphological explanation

Science.gov (United States)

Cox, Nicholas J.

2007-07-01

What characterises satisfactory explanations in geomorphology is a key methodological question deserving continued analysis. In turn it raises the issue of the role played by methodology within the science. At its best, methodology can provide helpful distinctions, identify key issues and yield guidance for researchers. The substantive context for debates on explanation is the apparent complexity and difficulty of geomorphology as a science, which is arguably no greater than that of other Earth or environmental sciences. The logical view of explanation dominant in the 1950s and 1960s still has value, but a broader view is needed of explanations, related to the questions geomorphologists (and others) ask and to the answers that they find interesting. Answers may be sought in terms of purpose, history, mechanisms and statistics. Arguments over what is supposed to be reductionism can be clarified by underlining that both micro- and macro-explanations may be helpful. Although many geomorphologists aspire to mechanistic explanations, they often stop short at statistical explanations, making use of convenient functional forms such as power laws. Explanations have both social and psychological dimensions, the former much stressed in history of science and recent science studies, the latter deserving greater emphasis at present. Complicated models raise the question of how far it can be said that geomorphologists understand them in totality. A bestiary of poor explanations is needed, so that geomorphologists are not seduced by weak arguments and because they often serve as steps towards better explanations. Circular arguments, ad hoc explanations, and mistaking the name of the problem for the solution are cases in point.

Contradictory or Complementary? Creationist and Evolutionist Explanations of the Origin(s) of Species

Science.gov (United States)

Evans, E. Margaret; Lane, Jonathan D.

2011-01-01

Almost half of the US public rejects the idea that humans originated via evolution rather than by supernatural design. Moreover, studies demonstrate that even biology teachers have difficulty teaching their students about evolution, often including creationist explanations as well. A typical response to such findings is the argument that greater…

Model-based explanation of plant knowledge

Energy Technology Data Exchange (ETDEWEB)

Huuskonen, P.J. [VTT Electronics, Oulu (Finland). Embedded Software

1997-12-31

This thesis deals with computer explanation of knowledge related to design and operation of industrial plants. The needs for explanation are motivated through case studies and literature reviews. A general framework for analysing plant explanations is presented. Prototypes demonstrate key mechanisms for implementing parts of the framework. Power plants, steel mills, paper factories, and high energy physics control systems are studied to set requirements for explanation. The main problems are seen to be either lack or abundance of information. Design knowledge in particular is found missing at plants. Support systems and automation should be enhanced with ways to explain plant knowledge to the plant staff. A framework is formulated for analysing explanations of plant knowledge. It consists of three parts: 1. a typology of explanation, organised by the class of knowledge (factual, functional, or strategic) and by the target of explanation (processes, automation, or support systems), 2. an identification of explanation tasks generic for the plant domain, and 3. an identification of essential model types for explanation (structural, behavioural, functional, and teleological). The tasks use the models to create the explanations of the given classes. Key mechanisms are discussed to implement the generic explanation tasks. Knowledge representations based on objects and their relations form a vocabulary to model and present plant knowledge. A particular class of models, means-end models, are used to explain plant knowledge. Explanations are generated through searches in the models. Hypertext is adopted to communicate explanations over dialogue based on context. The results are demonstrated in prototypes. The VICE prototype explains the reasoning of an expert system for diagnosis of rotating machines at power plants. The Justifier prototype explains design knowledge obtained from an object-oriented plant design tool. Enhanced access mechanisms into on-line documentation are

Model-based explanation of plant knowledge

Energy Technology Data Exchange (ETDEWEB)

Huuskonen, P J [VTT Electronics, Oulu (Finland). Embedded Software

1998-12-31

This thesis deals with computer explanation of knowledge related to design and operation of industrial plants. The needs for explanation are motivated through case studies and literature reviews. A general framework for analysing plant explanations is presented. Prototypes demonstrate key mechanisms for implementing parts of the framework. Power plants, steel mills, paper factories, and high energy physics control systems are studied to set requirements for explanation. The main problems are seen to be either lack or abundance of information. Design knowledge in particular is found missing at plants. Support systems and automation should be enhanced with ways to explain plant knowledge to the plant staff. A framework is formulated for analysing explanations of plant knowledge. It consists of three parts: 1. a typology of explanation, organised by the class of knowledge (factual, functional, or strategic) and by the target of explanation (processes, automation, or support systems), 2. an identification of explanation tasks generic for the plant domain, and 3. an identification of essential model types for explanation (structural, behavioural, functional, and teleological). The tasks use the models to create the explanations of the given classes. Key mechanisms are discussed to implement the generic explanation tasks. Knowledge representations based on objects and their relations form a vocabulary to model and present plant knowledge. A particular class of models, means-end models, are used to explain plant knowledge. Explanations are generated through searches in the models. Hypertext is adopted to communicate explanations over dialogue based on context. The results are demonstrated in prototypes. The VICE prototype explains the reasoning of an expert system for diagnosis of rotating machines at power plants. The Justifier prototype explains design knowledge obtained from an object-oriented plant design tool. Enhanced access mechanisms into on-line documentation are

Explanation components as interactive tools

Energy Technology Data Exchange (ETDEWEB)

Wahlster, W.

1983-01-01

The ability to explain itself is probably the most important criterion of the user-friendliness of interactive systems. Explanation aids in the form of simple help functions do not meet this criterion. The reasons for this are outlined. More promising is an explanation component which can give the user intelligible and context-oriented explanations. The essential requirement for this is the development of knowledge-based interactive systems using artificial intelligence methods and techniques. The authors report on experiences with the development of explanation components, in particular a number of examples from the HAM-ANS project. 12 references.

Evolutionary Explanations for Antibiotic Resistance in Daily Press, Online Websites and Biology Textbooks in Sweden

Science.gov (United States)

Bohlin, Gustav; Höst, Gunnar E.

2015-01-01

The present study explores the extent and precision of evolutionary explanations for antibiotic resistance in communication directed toward the Swedish public. Bacterial resistance develops through evolutionary mechanisms and knowledge of these helps to explain causes underlying the growing prevalence of resistant strains, as well as important…

Sequential and simultaneous multiple explanation

Directory of Open Access Journals (Sweden)

Robert Litchfield

2007-02-01

Full Text Available This paper reports two experiments comparing variants of multiple explanation applied in the early stages of a judgment task (a case involving employee theft where participants are not given a menu of response options. Because prior research has focused on situations where response options are provided to judges, we identify relevant dependent variables that an intervention might affect when such options are not given. We use these variables to build a causal model of intervention that illustrates both the intended effects of multiple explanation and some potentially competing processes that it may trigger. Although multiple explanation clearly conveys some benefits (e.g., willingness to delay action to engage in information search, increased detail, quality and confidence in alternative explanations in the present experiments, we also found evidence that it may initiate or enhance processes that attenuate its advantages (e.g., feelings that one does not need more data if one has multiple good explanations.

Biological insights from 108 schizophrenia-associated genetic loci

DEFF Research Database (Denmark)

Ripke, Stephan; Neale, Benjamin M.; Corvin, Aiden

2014-01-01

and 113,075 controls. We identify 128 independent associations spanning 108 conservatively defined loci that meet genome-wide significance, 83 of which have not been previously reported. Associations were enriched among genes expressed in brain, providing biological plausibility for the findings. Many...

Neural networks, nativism, and the plausibility of constructivism.

Science.gov (United States)

Quartz, S R

1993-09-01

Recent interest in PDP (parallel distributed processing) models is due in part to the widely held belief that they challenge many of the assumptions of classical cognitive science. In the domain of language acquisition, for example, there has been much interest in the claim that PDP models might undermine nativism. Related arguments based on PDP learning have also been given against Fodor's anti-constructivist position--a position that has contributed to the widespread dismissal of constructivism. A limitation of many of the claims regarding PDP learning, however, is that the principles underlying this learning have not been rigorously characterized. In this paper, I examine PDP models from within the framework of Valiant's PAC (probably approximately correct) model of learning, now the dominant model in machine learning, and which applies naturally to neural network learning. From this perspective, I evaluate the implications of PDP models for nativism and Fodor's influential anti-constructivist position. In particular, I demonstrate that, contrary to a number of claims, PDP models are nativist in a robust sense. I also demonstrate that PDP models actually serve as a good illustration of Fodor's anti-constructivist position. While these results may at first suggest that neural network models in general are incapable of the sort of concept acquisition that is required to refute Fodor's anti-constructivist position, I suggest that there is an alternative form of neural network learning that demonstrates the plausibility of constructivism. This alternative form of learning is a natural interpretation of the constructivist position in terms of neural network learning, as it employs learning algorithms that incorporate the addition of structure in addition to weight modification schemes. By demonstrating that there is a natural and plausible interpretation of constructivism in terms of neural network learning, the position that nativism is the only plausible model of

Mathematical biology

CERN Document Server

Murray, James D

1993-01-01

The book is a textbook (with many exercises) giving an in-depth account of the practical use of mathematical modelling in the biomedical sciences. The mathematical level required is generally not high and the emphasis is on what is required to solve the real biological problem. The subject matter is drawn, e.g. from population biology, reaction kinetics, biological oscillators and switches, Belousov-Zhabotinskii reaction, reaction-diffusion theory, biological wave phenomena, central pattern generators, neural models, spread of epidemics, mechanochemical theory of biological pattern formation and importance in evolution. Most of the models are based on real biological problems and the predictions and explanations offered as a direct result of mathematical analysis of the models are important aspects of the book. The aim is to provide a thorough training in practical mathematical biology and to show how exciting and novel mathematical challenges arise from a genuine interdisciplinary involvement with the biosci...

Relations between Intuitive Biological Thinking and Biological Misconceptions in Biology Majors and Nonmajors

Science.gov (United States)

Coley, John D.; Tanner, Kimberly

2015-01-01

Research and theory development in cognitive psychology and science education research remain largely isolated. Biology education researchers have documented persistent scientifically inaccurate ideas, often termed misconceptions, among biology students across biological domains. In parallel, cognitive and developmental psychologists have described intuitive conceptual systems—teleological, essentialist, and anthropocentric thinking—that humans use to reason about biology. We hypothesize that seemingly unrelated biological misconceptions may have common origins in these intuitive ways of knowing, termed cognitive construals. We presented 137 undergraduate biology majors and nonmajors with six biological misconceptions. They indicated their agreement with each statement, and explained their rationale for their response. Results indicate frequent agreement with misconceptions, and frequent use of construal-based reasoning among both biology majors and nonmajors in their written explanations. Moreover, results also show associations between specific construals and the misconceptions hypothesized to arise from those construals. Strikingly, such associations were stronger among biology majors than nonmajors. These results demonstrate important linkages between intuitive ways of thinking and misconceptions in discipline-based reasoning, and raise questions about the origins, persistence, and generality of relations between intuitive reasoning and biological misconceptions. PMID:25713093

Self-Explanation and Reading Strategy Training (SERT) Improves Low-Knowledge Students' Science Course Performance

Science.gov (United States)

McNamara, Danielle S.

2017-01-01

This study demonstrates the generalization of previous laboratory results showing the benefits of Self-Explanation Reading Training (SERT) to college students' course exam performance. The participants were 265 students enrolled in an Introductory Biology course, 59 of whom were provided with SERT. The results showed that SERT benefited students…

Generation of Plausible Hurricane Tracks for Preparedness Exercises

Science.gov (United States)

2017-04-25

product kernel. KDE with a beta kernel gene- rates maximum sustained winds, and linear regression simulates minimum central pressure. Maximum significant...the Storm level models the number of waypoints M , birth and death locations w1 and wM , and total number of steps L. The Stage level models the...MATLAB and leverages HURDAT2 to construct data-driven statistical models that can generate plausible yet never-before-seen storm behaviors. For a

Scientific explanation in school: An enactive view

Science.gov (United States)

Ibrahim-Didi, Khadeeja

This study explores explanation-in-action, a corollary to an enactive orientation to cognition. Explanation, understood this way is identified as a semiotic, perceptually driven activity, where the interactions that arise between students that enable the engagement to continue indicate a certain tentative coherence of meaning that is brought forth in interaction in a constraining environment. Challenging summary state views of explanation as statement, this study explores the evolution of scientific explanation in two Grade Eight Maldivian classrooms. Enactivism, understood across different embodied cognitive systems, reconfigures the discourse on explanation by re-orienting the form in which explanation is understood. The notion of explanation-in-action as a topological function implicates the boundary of the cognitive system in the action. Further, it also recognizes that embedding boundaries and the dynamics that create the boundaries can constrain the explanation that occurs in different domains. In effect, the study calls for reconfiguring validation as in-action---as the constraining dynamic feature that emerges in the ongoing explanation-in-action. In the study I pay attention to the different boundaries of some systemic configurations in the classroom. I consider how the boundary conditions create the possibility for signification, and therefore, explanation. This research suggests that in explaining-in-action students are able to draw on the enabling possibilities of personal boundaries and the constraining social boundaries to further structure their explaining in ways that are local to the task at hand.

Beyond Epistemological Deficits: Dynamic explanations of engineering students' difficulties with mathematical sense-making

Science.gov (United States)

Gupta, Ayush; Elby, Andrew

2011-12-01

Researchers have argued against deficit-based explanations of students' difficulties with mathematical sense-making, pointing instead to factors such as epistemology. Students' beliefs about knowledge and learning can hinder the activation and integration of productive knowledge they have. Such explanations, however, risk falling into a 'deficit trap'-substituting a concepts/skills deficit with an epistemological one. Our interview-based case study of a freshman engineering major, 'Jim,' explains his difficulty solving a physics problem (on hydrostatic pressure) in terms of his epistemology, but avoids a deficit trap by modeling the dynamics of his epistemological stabilities and shifts in terms of fine-grained cognitive elements that include the seeds of epistemological expertise. Specifically, during a problem-solving episode in the interview, Jim reaches and sticks with an incorrect answer that violates common sense. We show that Jim has all the mathematical skills and physics knowledge he would need to resolve the contradiction. We argue that his difficulty doing so stems in part from his epistemological views that (i) physics equations are much more trustworthy than everyday reasoning, and (ii) physics equations do not express meaning that tractably connects to common sense. For these reasons, he does not view reconciling between common sense and formalism as either necessary or plausible to accomplish. But Jim's in-the-moment shift to a more sophisticated epistemological stance highlights the seeds of epistemological expertise that were present all along: he does see common sense as connected to formalism (though not always tractably so), and in some circumstances, this connection is both salient and valued.

What causes addiction problems? Environmental, biological and constitutional explanations in press portrayals from four European welfare societies.

Science.gov (United States)

Hellman, Matilda; Majamäki, Maija; Rolando, Sara; Bujalski, Michał; Lemmens, Paul

2015-03-01

Press items (N = 1327) about addiction related problems were collected from politically independent daily newspapers in Finland, Italy, the Netherlands, and Poland from 1991, 1998, and 2011. A synchronized qualitative coding was performed for discerning the descriptions of the genesis to the problems in terms of described causes to and reasons for why they occur. Environmental explanations were by far the most common and they varied most between the materials. The analysis documents how the portrayals include traces of their contextual origin, relating to different media tasks and welfare cultural traditions. Meaning-based differences were also assigned to the kind of problems that held the most salience in the press reporting. A general worry over societal change is tied into the explanations of accumulating addiction problems and underpins the press reporting in all countries.

Theory-based explanation as intervention.

Science.gov (United States)

Weisman, Kara; Markman, Ellen M

2017-10-01

Cogent explanations are an indispensable means of providing new information and an essential component of effective education. Beyond this, we argue that there is tremendous untapped potential in using explanations to motivate behavior change. In this article we focus on health interventions. We review four case studies that used carefully tailored explanations to address gaps and misconceptions in people's intuitive theories, providing participants with a conceptual framework for understanding how and why some recommended behavior is an effective way of achieving a health goal. These case studies targeted a variety of health-promoting behaviors: (1) children washing their hands to prevent viral epidemics; (2) parents vaccinating their children to stem the resurgence of infectious diseases; (3) adults completing the full course of an antibiotic prescription to reduce antibiotic resistance; and (4) children eating a variety of healthy foods to improve unhealthy diets. Simply telling people to engage in these behaviors has been largely ineffective-if anything, concern about these issues is mounting. But in each case, teaching participants coherent explanatory frameworks for understanding health recommendations has shown great promise, with such theory-based explanations outperforming state-of-the-art interventions from national health authorities. We contrast theory-based explanations both with simply listing facts, information, and advice and with providing a full-blown educational curriculum, and argue for providing the minimum amount of information required to understand the causal link between a target behavior and a health outcome. We argue that such theory-based explanations lend people the motivation and confidence to act on their new understanding.

Great Explanations: Opinionated Explanations for Recommendation

OpenAIRE

Muhammad, Khalil; Lawlor, Aonghus; Rafter, Rachael; Smyth, Barry

2015-01-01

Explaining recommendations helps users to make better, more satisfying decisions. We describe a novel approach to explanation for recommender systems, one that drives the recommendation process, while at the same time providing the user with useful insights into the reason why items have been chosen and the trade-os they may need to consider when making their choice. We describe this approach in the context ofa case-based recommender system that harnesses opinions mined from user-generated re...

Consistent robustness analysis (CRA) identifies biologically relevant properties of regulatory network models.

Science.gov (United States)

Saithong, Treenut; Painter, Kevin J; Millar, Andrew J

2010-12-16

A number of studies have previously demonstrated that "goodness of fit" is insufficient in reliably classifying the credibility of a biological model. Robustness and/or sensitivity analysis is commonly employed as a secondary method for evaluating the suitability of a particular model. The results of such analyses invariably depend on the particular parameter set tested, yet many parameter values for biological models are uncertain. Here, we propose a novel robustness analysis that aims to determine the "common robustness" of the model with multiple, biologically plausible parameter sets, rather than the local robustness for a particular parameter set. Our method is applied to two published models of the Arabidopsis circadian clock (the one-loop [1] and two-loop [2] models). The results reinforce current findings suggesting the greater reliability of the two-loop model and pinpoint the crucial role of TOC1 in the circadian network. Consistent Robustness Analysis can indicate both the relative plausibility of different models and also the critical components and processes controlling each model.

Alternative explanations of the cosmic microwave background: A historical and an epistemological perspective

Science.gov (United States)

Ćirković, Milan M.; Perović, Slobodan

2018-05-01

We historically trace various non-conventional explanations for the origin of the cosmic microwave background and discuss their merit, while analyzing the dynamics of their rejection, as well as the relevant physical and methodological reasons for it. It turns out that there have been many such unorthodox interpretations; not only those developed in the context of theories rejecting the relativistic ("Big Bang") paradigm entirely (e.g., by Alfvén, Hoyle and Narlikar) but also those coming from the camp of original thinkers firmly entrenched in the relativistic milieu (e.g., by Rees, Ellis, Rowan-Robinson, Layzer and Hively). In fact, the orthodox interpretation has only incrementally won out against the alternatives over the course of the three decades of its multi-stage development. While on the whole, none of the alternatives to the hot Big Bang scenario is persuasive today, we discuss the epistemic ramifications of establishing orthodoxy and eliminating alternatives in science, an issue recently discussed by philosophers and historians of science for other areas of physics. Finally, we single out some plausible and possibly fruitful ideas offered by the alternatives.

A Model of How Different Biology Experts Explain Molecular and Cellular Mechanisms

Science.gov (United States)

Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

2015-01-01

Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do…

Automated Explanation for Educational Applications.

Science.gov (United States)

Suthers, Daniel D.

1991-01-01

Artificial intelligence techniques available for generating explanations for teaching purposes are surveyed, and the way in which they are combined in a computer program that provides explanations is described. The program responds to questions in the physical sciences. Potential contributions of this technology to computer-based education are…

Of paradox and plausibility: the dynamic of change in medical law.

Science.gov (United States)

Harrington, John

2014-01-01

This article develops a model of change in medical law. Drawing on systems theory, it argues that medical law participates in a dynamic of 'deparadoxification' and 'reparadoxification' whereby the underlying contingency of the law is variously concealed through plausible argumentation, or revealed by critical challenge. Medical law is, thus, thoroughly rhetorical. An examination of the development of the law on abortion and on the sterilization of incompetent adults shows that plausibility is achieved through the deployment of substantive common sense and formal stylistic devices. It is undermined where these elements are shown to be arbitrary and constructed. In conclusion, it is argued that the politics of medical law are constituted by this antagonistic process of establishing and challenging provisionally stable normative regimes. © The Author [2014]. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

Qualitative explanations for red giant formation

International Nuclear Information System (INIS)

Bhaskar, R.; Nigam, A.

1991-01-01

Recent research on giant formation has focused on the need for qualitative explanations. The explanations have the following general, qualitative form: the polytrope n assumes a certain value, that makes (d ln r)/(d ln z) take on a very large value; large increases in r can then be explained in terms of small changes in the variable z. This form is applicable to all the explanations current in the literature: they all have (1) either implicitly or explicitly, both a hydrostatic component and a luminosity-opacity component, and (2) a reliance on singular solutions. Dimensional analysis reveals that power laws that assume the polytrope n to 5 are identical in both the hydrostatic and luminosity-based explanations. 12 refs

An evolutionary explanation model on the transformation of culture by cultural genes*

OpenAIRE

Lee, Han

2009-01-01

This article seeks to explain how cultural transformation takes place through the evolution of cultural genes. This explanation posits that just as the evolution of an organism takes place at the genetic level, so also does the transformation of culture. As such, this paper must answer the four following questions: 1) Are there cultural genes that correspond to biological genes? 2) How can we prove that the fundamental characteristic of such cultural genes is to replicate themselves? 3) Will ...

Motivated Explanation

Directory of Open Access Journals (Sweden)

Richard ePatterson

2015-10-01

Full Text Available Although motivation is a well-established field of study in its own right, and has been fruitfully studied in connection with attribution theory and belief formation under the heading of motivated thinking, its powerful and pervasive influence on explanatory processes is less well explored. Where one has a strong motivation to understand some event correctly, one is thereby motivated to adhere as best one can to normative or epistemic criteria for correct or accurate explanation, even if one does not consciously formulate or apply such criteria. By contrast, many of our motivations to explain introduce bias into the processes involved in generating, evaluating, or giving of explanations. Non-epistemic explanatory motivations, or (following Kunda’s usage, directional motivations, include self-justification, resolution of cognitive dissonance, deliberate deception, teaching, and many more. Some of these motivations lead to the relaxation or violation of epistemic norms, combined with an effort to preserve the appearance of accuracy; others enhance epistemic motivation, so that one engages in more careful and thorough generational and evaluative processes. In short, real life explanatory processes are often constrained by multiple goals, epistemic and directional, where these goals may mutually reinforce one another or may conflict, and where our explanations emerge as a matter of weighing and satisfying those goals. Our proposals are largely programmatic, although we do review a good deal of relevant behavioral and neurological evidence. Specifically, we recognize five generative processes, some of which cover further sub-processes, and six evaluative processes. All of these are potential points of entry for the influence of motivation. We then suggest in some detail how specific sorts of explanatory motivation interact with specific explanatory processes.

A Stochastic Model of Plausibility in Live Virtual Constructive Environments

Science.gov (United States)

2017-09-14

from the model parameters that are inputs to the computer model ( mathematical model) but whose exact values are unknown to experimentalists and...Environments Jeremy R. Millar Follow this and additional works at: https://scholar.afit.edu/etd Part of the Computer Sciences Commons This Dissertation...25 3.3 Computing Plausibility Exceedance Probabilities . . . . . . . . . . . . . . . . . . . 28 IV

Depressive symptoms predict head and neck cancer survival: Examining plausible behavioral and biological pathways.

Science.gov (United States)

Zimmaro, Lauren A; Sephton, Sandra E; Siwik, Chelsea J; Phillips, Kala M; Rebholz, Whitney N; Kraemer, Helena C; Giese-Davis, Janine; Wilson, Liz; Bumpous, Jeffrey M; Cash, Elizabeth D

2018-03-01

Head and neck cancers are associated with high rates of depression, which may increase the risk for poorer immediate and long-term outcomes. Here it was hypothesized that greater depressive symptoms would predict earlier mortality, and behavioral (treatment interruption) and biological (treatment response) mediators were examined. Patients (n = 134) reported depressive symptomatology at treatment planning. Clinical data were reviewed at the 2-year follow-up. Greater depressive symptoms were associated with significantly shorter survival (hazard ratio, 0.868; 95% confidence interval [CI], 0.819-0.921; P ratio, 0.865; 95% CI, 0.774-0.966; P = .010), and poorer treatment response (odds ratio, 0.879; 95% CI, 0.803-0.963; P = .005). The poorer treatment response partially explained the depression-survival relation. Other known prognostic indicators did not challenge these results. Depressive symptoms at the time of treatment planning predict overall 2-year mortality. Effects are partly influenced by the treatment response. Depression screening and intervention may be beneficial. Future studies should examine parallel biological pathways linking depression to cancer survival, including endocrine disruption and inflammation. Cancer 2018;124:1053-60. © 2018 American Cancer Society. © 2018 American Cancer Society.

Trial-by-Trial Modulation of Associative Memory Formation by Reward Prediction Error and Reward Anticipation as Revealed by a Biologically Plausible Computational Model.

Science.gov (United States)

Aberg, Kristoffer C; Müller, Julia; Schwartz, Sophie

2017-01-01

Anticipation and delivery of rewards improves memory formation, but little effort has been made to disentangle their respective contributions to memory enhancement. Moreover, it has been suggested that the effects of reward on memory are mediated by dopaminergic influences on hippocampal plasticity. Yet, evidence linking memory improvements to actual reward computations reflected in the activity of the dopaminergic system, i.e., prediction errors and expected values, is scarce and inconclusive. For example, different previous studies reported that the magnitude of prediction errors during a reinforcement learning task was a positive, negative, or non-significant predictor of successfully encoding simultaneously presented images. Individual sensitivities to reward and punishment have been found to influence the activation of the dopaminergic reward system and could therefore help explain these seemingly discrepant results. Here, we used a novel associative memory task combined with computational modeling and showed independent effects of reward-delivery and reward-anticipation on memory. Strikingly, the computational approach revealed positive influences from both reward delivery, as mediated by prediction error magnitude, and reward anticipation, as mediated by magnitude of expected value, even in the absence of behavioral effects when analyzed using standard methods, i.e., by collapsing memory performance across trials within conditions. We additionally measured trait estimates of reward and punishment sensitivity and found that individuals with increased reward (vs. punishment) sensitivity had better memory for associations encoded during positive (vs. negative) prediction errors when tested after 20 min, but a negative trend when tested after 24 h. In conclusion, modeling trial-by-trial fluctuations in the magnitude of reward, as we did here for prediction errors and expected value computations, provides a comprehensive and biologically plausible description of

Biology meets Physics: Reductionism and Multi-scale Modeling of Morphogenesis

DEFF Research Database (Denmark)

Green, Sara; Batterman, Robert

2017-01-01

A common reductionist assumption is that macro-scale behaviors can be described "bottom-up" if only sufficient details about lower-scale processes are available. The view that an "ideal" or "fundamental" physics would be sufficient to explain all macro-scale phenomena has been met with criticism ...... modeling in developmental biology. In such contexts, the relation between models at different scales and from different disciplines is neither reductive nor completely autonomous, but interdependent....... from philosophers of biology. Specifically, scholars have pointed to the impossibility of deducing biological explanations from physical ones, and to the irreducible nature of distinctively biological processes such as gene regulation and evolution. This paper takes a step back in asking whether bottom......-up modeling is feasible even when modeling simple physical systems across scales. By comparing examples of multi-scale modeling in physics and biology, we argue that the “tyranny of scales” problem present a challenge to reductive explanations in both physics and biology. The problem refers to the scale...

Dimensions of integration in interdisciplinary explanations of the origin of evolutionary novelty.

Science.gov (United States)

Love, Alan C; Lugar, Gary L

2013-12-01

Many philosophers of biology have embraced a version of pluralism in response to the failure of theory reduction but overlook how concepts, methods, and explanatory resources are in fact coordinated, such as in interdisciplinary research where the aim is to integrate different strands into an articulated whole. This is observable for the origin of evolutionary novelty-a complex problem that requires a synthesis of intellectual resources from different fields to arrive at robust answers to multiple allied questions. It is an apt locus for exploring new dimensions of explanatory integration because it necessitates coordination among historical and experimental disciplines (e.g., geology and molecular biology). These coordination issues are widespread for the origin of novel morphologies observed in the Cambrian Explosion. Despite an explicit commitment to an integrated, interdisciplinary explanation, some potential disciplinary contributors are excluded. Notable among these exclusions is the physics of ontogeny. We argue that two different dimensions of integration-data and standards-have been insufficiently distinguished. This distinction accounts for why physics-based explanatory contributions to the origin of novelty have been resisted: they do not integrate certain types of data and differ in how they conceptualize the standard of uniformitarianism in historical, causal explanations. Our analysis of these different dimensions of integration contributes to the development of more adequate and integrated explanatory frameworks. Copyright © 2013 Elsevier Ltd. All rights reserved.

Toward Petascale Biologically Plausible Neural Networks

Science.gov (United States)

Long, Lyle

This talk will describe an approach to achieving petascale neural networks. Artificial intelligence has been oversold for many decades. Computers in the beginning could only do about 16,000 operations per second. Computer processing power, however, has been doubling every two years thanks to Moore's law, and growing even faster due to massively parallel architectures. Finally, 60 years after the first AI conference we have computers on the order of the performance of the human brain (1016 operations per second). The main issues now are algorithms, software, and learning. We have excellent models of neurons, such as the Hodgkin-Huxley model, but we do not know how the human neurons are wired together. With careful attention to efficient parallel computing, event-driven programming, table lookups, and memory minimization massive scale simulations can be performed. The code that will be described was written in C + + and uses the Message Passing Interface (MPI). It uses the full Hodgkin-Huxley neuron model, not a simplified model. It also allows arbitrary network structures (deep, recurrent, convolutional, all-to-all, etc.). The code is scalable, and has, so far, been tested on up to 2,048 processor cores using 107 neurons and 109 synapses.

A plausible neural circuit for decision making and its formation based on reinforcement learning.

Science.gov (United States)

Wei, Hui; Dai, Dawei; Bu, Yijie

2017-06-01

A human's, or lower insects', behavior is dominated by its nervous system. Each stable behavior has its own inner steps and control rules, and is regulated by a neural circuit. Understanding how the brain influences perception, thought, and behavior is a central mandate of neuroscience. The phototactic flight of insects is a widely observed deterministic behavior. Since its movement is not stochastic, the behavior should be dominated by a neural circuit. Based on the basic firing characteristics of biological neurons and the neural circuit's constitution, we designed a plausible neural circuit for this phototactic behavior from logic perspective. The circuit's output layer, which generates a stable spike firing rate to encode flight commands, controls the insect's angular velocity when flying. The firing pattern and connection type of excitatory and inhibitory neurons are considered in this computational model. We simulated the circuit's information processing using a distributed PC array, and used the real-time average firing rate of output neuron clusters to drive a flying behavior simulation. In this paper, we also explored how a correct neural decision circuit is generated from network flow view through a bee's behavior experiment based on the reward and punishment feedback mechanism. The significance of this study: firstly, we designed a neural circuit to achieve the behavioral logic rules by strictly following the electrophysiological characteristics of biological neurons and anatomical facts. Secondly, our circuit's generality permits the design and implementation of behavioral logic rules based on the most general information processing and activity mode of biological neurons. Thirdly, through computer simulation, we achieved new understanding about the cooperative condition upon which multi-neurons achieve some behavioral control. Fourthly, this study aims in understanding the information encoding mechanism and how neural circuits achieve behavior control

Increased scientific rigor will improve reliability of research and effectiveness of management

Science.gov (United States)

Sells, Sarah N.; Bassing, Sarah B.; Barker, Kristin J.; Forshee, Shannon C.; Keever, Allison; Goerz, James W.; Mitchell, Michael S.

2018-01-01

Rigorous science that produces reliable knowledge is critical to wildlife management because it increases accurate understanding of the natural world and informs management decisions effectively. Application of a rigorous scientific method based on hypothesis testing minimizes unreliable knowledge produced by research. To evaluate the prevalence of scientific rigor in wildlife research, we examined 24 issues of the Journal of Wildlife Management from August 2013 through July 2016. We found 43.9% of studies did not state or imply a priori hypotheses, which are necessary to produce reliable knowledge. We posit that this is due, at least in part, to a lack of common understanding of what rigorous science entails, how it produces more reliable knowledge than other forms of interpreting observations, and how research should be designed to maximize inferential strength and usefulness of application. Current primary literature does not provide succinct explanations of the logic behind a rigorous scientific method or readily applicable guidance for employing it, particularly in wildlife biology; we therefore synthesized an overview of the history, philosophy, and logic that define scientific rigor for biological studies. A rigorous scientific method includes 1) generating a research question from theory and prior observations, 2) developing hypotheses (i.e., plausible biological answers to the question), 3) formulating predictions (i.e., facts that must be true if the hypothesis is true), 4) designing and implementing research to collect data potentially consistent with predictions, 5) evaluating whether predictions are consistent with collected data, and 6) drawing inferences based on the evaluation. Explicitly testing a priori hypotheses reduces overall uncertainty by reducing the number of plausible biological explanations to only those that are logically well supported. Such research also draws inferences that are robust to idiosyncratic observations and

WPPSS debacle: explanations and lessons

International Nuclear Information System (INIS)

Meyer, M.B.

1984-01-01

Principal explanations for the WPPSS events to date can be more or less satisfactorily derived. Five explanations appear to dominate: (1) the long and previously successful history of public power in the Pacific Northwest; (2) overoptimism by architect/engineers and consulting engineers about construction costs and construction durations; (3) laxness by bond counsel in scrutinizing and disclosing potential legal impediments to the various transactions involved; (4) WPPSS easy access to capital markets, combined with naivete in those markets; and (5) the inability of WPPSS to manage and oversee the construction process. This paper explains the specific reasons for, and the importance of, each of these five explanations for the WPPSS debacle. It then develops lessons and conclusions for the future which can be derived from this debacle. 12 references

Scientific Explanations and Piagetian Operational Levels.

Science.gov (United States)

Bass, Joel E.; Maddux, Cleborne D.

1982-01-01

Examined effects of operational levels of ninth-grade (N=16) and college (N=40) students on causal explanations they recalled after instruction. Results indicate concrete/formal students recalled explanations requiring chaining of two implication statements while formal subjects outperformed concrete subjects in reconstruction of complex…

Synthetic biology and its alternatives. Descartes, Kant and the idea of engineering biological machines.

Science.gov (United States)

Kogge, Werner; Richter, Michael

2013-06-01

The engineering-based approach of synthetic biology is characterized by an assumption that 'engineering by design' enables the construction of 'living machines'. These 'machines', as biological machines, are expected to display certain properties of life, such as adapting to changing environments and acting in a situated way. This paper proposes that a tension exists between the expectations placed on biological artefacts and the notion of producing such systems by means of engineering; this tension makes it seem implausible that biological systems, especially those with properties characteristic of living beings, can in fact be produced using the specific methods of engineering. We do not claim that engineering techniques have nothing to contribute to the biotechnological construction of biological artefacts. However, drawing on Descartes's and Kant's thinking on the relationship between the organism and the machine, we show that it is considerably more plausible to assume that distinctively biological artefacts emerge within a paradigm different from the paradigm of the Cartesian machine that underlies the engineering approach. We close by calling for increased attention to be paid to approaches within molecular biology and chemistry that rest on conceptions different from those of synthetic biology's engineering paradigm. Copyright © 2013 Elsevier Ltd. All rights reserved.

Using Animals to Teach Children Biology: Exploring the Use of Biological Explanations in Children's Anthropomorphic Storybooks

Science.gov (United States)

Geerdts, Megan; Van De Walle, Gretchen; LoBue, Vanessa

2016-01-01

Research Findings: Anthropomorphism--the attribution of human characteristics to nonhuman entities--has long been a staple of children's media. However, children's experiences with anthropomorphic media may interfere with biological reasoning instead encouraging an anthropocentric view of the natural world. To date, little research has addressed…

Investigating Assessment Bias for Constructed Response Explanation Tasks: Implications for Evaluating Performance Expectations for Scientific Practice

Science.gov (United States)

Federer, Meghan Rector

Assessment is a key element in the process of science education teaching and research. Understanding sources of performance bias in science assessment is a major challenge for science education reforms. Prior research has documented several limitations of instrument types on the measurement of students' scientific knowledge (Liu et al., 2011; Messick, 1995; Popham, 2010). Furthermore, a large body of work has been devoted to reducing assessment biases that distort inferences about students' science understanding, particularly in multiple-choice [MC] instruments. Despite the above documented biases, much has yet to be determined for constructed response [CR] assessments in biology and their use for evaluating students' conceptual understanding of scientific practices (such as explanation). Understanding differences in science achievement provides important insights into whether science curricula and/or assessments are valid representations of student abilities. Using the integrative framework put forth by the National Research Council (2012), this dissertation aimed to explore whether assessment biases occur for assessment practices intended to measure students' conceptual understanding and proficiency in scientific practices. Using a large corpus of undergraduate biology students' explanations, three studies were conducted to examine whether known biases of MC instruments were also apparent in a CR instrument designed to assess students' explanatory practice and understanding of evolutionary change (ACORNS: Assessment of COntextual Reasoning about Natural Selection). The first study investigated the challenge of interpreting and scoring lexically ambiguous language in CR answers. The incorporation of 'multivalent' terms into scientific discourse practices often results in statements or explanations that are difficult to interpret and can produce faulty inferences about student knowledge. The results of this study indicate that many undergraduate biology majors

Representations of homosexuality and prejudice against homosexuals of college students in a course in biology education in Mozambique

OpenAIRE

Nota, Juvencio Manuel

2014-01-01

This article analyzes the representations (explanations) of future biology teachers about the nature of homosexuality and the type of prejudice expressed against homosexuals. For this we applied questionnaires to 127 students of both sexes from first to fourth year biology course in Pedagogical University in Maputo. The results showed a bipolar representation of homosexuality reasoned explanations psychosocial and biological, but also a widespread prejudice. The analysis of the type of anchor...

Teleology in biology, chemistry and physics education: what primary teachers should know

Directory of Open Access Journals (Sweden)

KOSTAS KAMPOURAKIS

2007-01-01

Full Text Available Recent research in cognitive psychology suggests that children develop intuitions that may clash with what is accepted by scientists, thus making certain scientific concepts difficult to understand. Children possess intuitions about design and purpose that make them provide teleological explanations to many different sorts of tasks. One possible explanation for the origin of the bias to view objects as made for something derives from an early sensitivity to intentional agents and to their behavior as intentional object users and object makers. What is important is that teleological explanations may not be exclusively restricted in biological phenomena, as commonly assumed. Consequently, primary school teachers should take that into account when teaching biology, chemistry or physics concepts and try to refrain from enforcing students’ teleological intuitions.

Probabilistic reasoning in intelligent systems networks of plausible inference

CERN Document Server

Pearl, Judea

1988-01-01

Probabilistic Reasoning in Intelligent Systems is a complete and accessible account of the theoretical foundations and computational methods that underlie plausible reasoning under uncertainty. The author provides a coherent explication of probability as a language for reasoning with partial belief and offers a unifying perspective on other AI approaches to uncertainty, such as the Dempster-Shafer formalism, truth maintenance systems, and nonmonotonic logic. The author distinguishes syntactic and semantic approaches to uncertainty--and offers techniques, based on belief networks, that provid

A Note on Unified Statistics Including Fermi-Dirac, Bose-Einstein, and Tsallis Statistics, and Plausible Extension to Anisotropic Effect

Directory of Open Access Journals (Sweden)

Christianto V.

2007-04-01

Full Text Available In the light of some recent hypotheses suggesting plausible unification of thermostatistics where Fermi-Dirac, Bose-Einstein and Tsallis statistics become its special subsets, we consider further plausible extension to include non-integer Hausdorff dimension, which becomes realization of fractal entropy concept. In the subsequent section, we also discuss plausible extension of this unified statistics to include anisotropic effect by using quaternion oscillator, which may be observed in the context of Cosmic Microwave Background Radiation. Further observation is of course recommended in order to refute or verify this proposition.

Evolution, Entropy, & Biological Information

Science.gov (United States)

Peterson, Jacob

2014-01-01

A logical question to be expected from students: "How could life develop, that is, change, evolve from simple, primitive organisms into the complex forms existing today, while at the same time there is a generally observed decline and disorganization--the second law of thermodynamics?" The explanations in biology textbooks relied upon by…

Semantics-based plausible reasoning to extend the knowledge coverage of medical knowledge bases for improved clinical decision support.

Science.gov (United States)

Mohammadhassanzadeh, Hossein; Van Woensel, William; Abidi, Samina Raza; Abidi, Syed Sibte Raza

2017-01-01

Capturing complete medical knowledge is challenging-often due to incomplete patient Electronic Health Records (EHR), but also because of valuable, tacit medical knowledge hidden away in physicians' experiences. To extend the coverage of incomplete medical knowledge-based systems beyond their deductive closure, and thus enhance their decision-support capabilities, we argue that innovative, multi-strategy reasoning approaches should be applied. In particular, plausible reasoning mechanisms apply patterns from human thought processes, such as generalization, similarity and interpolation, based on attributional, hierarchical, and relational knowledge. Plausible reasoning mechanisms include inductive reasoning , which generalizes the commonalities among the data to induce new rules, and analogical reasoning , which is guided by data similarities to infer new facts. By further leveraging rich, biomedical Semantic Web ontologies to represent medical knowledge, both known and tentative, we increase the accuracy and expressivity of plausible reasoning, and cope with issues such as data heterogeneity, inconsistency and interoperability. In this paper, we present a Semantic Web-based, multi-strategy reasoning approach, which integrates deductive and plausible reasoning and exploits Semantic Web technology to solve complex clinical decision support queries. We evaluated our system using a real-world medical dataset of patients with hepatitis, from which we randomly removed different percentages of data (5%, 10%, 15%, and 20%) to reflect scenarios with increasing amounts of incomplete medical knowledge. To increase the reliability of the results, we generated 5 independent datasets for each percentage of missing values, which resulted in 20 experimental datasets (in addition to the original dataset). The results show that plausibly inferred knowledge extends the coverage of the knowledge base by, on average, 2%, 7%, 12%, and 16% for datasets with, respectively, 5%, 10%, 15

Relations between intuitive biological thinking and biological misconceptions in biology majors and nonmajors.

Science.gov (United States)

Coley, John D; Tanner, Kimberly

2015-03-02

Research and theory development in cognitive psychology and science education research remain largely isolated. Biology education researchers have documented persistent scientifically inaccurate ideas, often termed misconceptions, among biology students across biological domains. In parallel, cognitive and developmental psychologists have described intuitive conceptual systems--teleological, essentialist, and anthropocentric thinking--that humans use to reason about biology. We hypothesize that seemingly unrelated biological misconceptions may have common origins in these intuitive ways of knowing, termed cognitive construals. We presented 137 undergraduate biology majors and nonmajors with six biological misconceptions. They indicated their agreement with each statement, and explained their rationale for their response. Results indicate frequent agreement with misconceptions, and frequent use of construal-based reasoning among both biology majors and nonmajors in their written explanations. Moreover, results also show associations between specific construals and the misconceptions hypothesized to arise from those construals. Strikingly, such associations were stronger among biology majors than nonmajors. These results demonstrate important linkages between intuitive ways of thinking and misconceptions in discipline-based reasoning, and raise questions about the origins, persistence, and generality of relations between intuitive reasoning and biological misconceptions. © 2015 J. D. Coley and K. Tanner. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Cross-Country Individual Participant Analysis of 4.1 Million Singleton Births in 5 Countries with Very High Human Development Index Confirms Known Associations but Provides No Biologic Explanation for 2/3 of All Preterm Births.

Science.gov (United States)

Ferrero, David M; Larson, Jim; Jacobsson, Bo; Di Renzo, Gian Carlo; Norman, Jane E; Martin, James N; D'Alton, Mary; Castelazo, Ernesto; Howson, Chris P; Sengpiel, Verena; Bottai, Matteo; Mayo, Jonathan A; Shaw, Gary M; Verdenik, Ivan; Tul, Nataša; Velebil, Petr; Cairns-Smith, Sarah; Rushwan, Hamid; Arulkumaran, Sabaratnam; Howse, Jennifer L; Simpson, Joe Leigh

2016-01-01

Preterm birth is the most common single cause of perinatal and infant mortality, affecting 15 million infants worldwide each year with global rates increasing. Understanding of risk factors remains poor, and preventive interventions have only limited benefit. Large differences exist in preterm birth rates across high income countries. We hypothesized that understanding the basis for these wide variations could lead to interventions that reduce preterm birth incidence in countries with high rates. We thus sought to assess the contributions of known risk factors for both spontaneous and provider-initiated preterm birth in selected high income countries, estimating also the potential impact of successful interventions due to advances in research, policy and public health, or clinical practice. We analyzed individual patient-level data on 4.1 million singleton pregnancies from four countries with very high human development index (Czech Republic, New Zealand, Slovenia, Sweden) and one comparator U.S. state (California) to determine the specific contribution (adjusting for confounding effects) of 21 factors. Both individual and population-attributable preterm birth risks were determined, as were contributors to cross-country differences. We also assessed the ability to predict preterm birth given various sets of known risk factors. Previous preterm birth and preeclampsia were the strongest individual risk factors of preterm birth in all datasets, with odds ratios of 4.6-6.0 and 2.8-5.7, respectively, for individual women having those characteristics. In contrast, on a population basis, nulliparity and male sex were the two risk factors with the highest impact on preterm birth rates, accounting for 25-50% and 11-16% of excess population attributable risk, respectively (pbirth within each country lacks a plausible biologic explanation, and 63% of difference between countries cannot be explained with known factors; thus, research is necessary to elucidate the underlying

Biological Evolution and the History of the Earth Are Foundations of Science

Science.gov (United States)

2008-01-01

AGU affirms the central importance of including scientific theories of Earth history and biological evolution in science education. Within the scientific community, the theory of biological evolution is not controversial, nor have ``alternative explanations'' been found. This is why no competing theories are required by the U.S. National Science Education Standards. Explanations of natural phenomena that appeal to the supernatural or are based on religious doctrine-and therefore cannot be tested through scientific inquiry-are not scientific, and have no place in the science classroom.

Theories and models on the biological of cells in space

Science.gov (United States)

Todd, P.; Klaus, D. M.

1996-01-01

A wide variety of observations on cells in space, admittedly made under constraining and unnatural conditions in may cases, have led to experimental results that were surprising or unexpected. Reproducibility, freedom from artifacts, and plausibility must be considered in all cases, even when results are not surprising. The papers in symposium on 'Theories and Models on the Biology of Cells in Space' are dedicated to the subject of the plausibility of cellular responses to gravity -- inertial accelerations between 0 and 9.8 m/sq s and higher. The mechanical phenomena inside the cell, the gravitactic locomotion of single eukaryotic and prokaryotic cells, and the effects of inertial unloading on cellular physiology are addressed in theoretical and experimental studies.

Is the bias for function-based explanations culturally universal? Children from China endorse teleological explanations of natural phenomena

Science.gov (United States)

Schachner, Adena; Zhu, Liqi; Li, Jing; Kelemen, Deborah

2017-01-01

Young children in Western cultures tend to endorse teleological (function-based) explanations broadly across many domains, even when scientifically unwarranted. For instance, in contrast to Western adults, they explicitly endorse the idea that mountains were created for climbing, just like hats were created for warmth. Is this bias a product of culture, or a product of universal aspects of human cognition? In two studies, we explored whether adults and children in Mainland China, a highly secular, non-Western culture, show a bias for teleological explanations. When explaining both object properties (Exp. 1) and origins (Exp. 2), we found evidence that they do. While Chinese adults restricted teleological explanations to scientifically warranted cases, Chinese children endorsed them more broadly, extending them across different kinds of natural phenomena. This bias decreased with rising grade level across first, second and fourth grade. Overall, these data provide evidence that children’s bias for teleological explanations is not solely a product of Western Abrahamic cultures. Instead, it extends to other cultures including the East Asian secular culture of modern-day China. This suggests that the bias for function-based explanations may be driven by universal aspects of human cognition. PMID:28110152

Axis: Generating Explanations at Scale with Learnersourcing and Machine Learning

Science.gov (United States)

Williams, Joseph Jay; Kim, Juho; Rafferty, Anna; Heffernan, Neil; Maldonado, Samuel; Gajos, Krzysztof Z.; Lasecki, Walter S.; Heffernan, Neil

2016-01-01

While explanations may help people learn by providing information about why an answer is correct, many problems on online platforms lack high-quality explanations. This paper presents AXIS (Adaptive eXplanation Improvement System), a system for obtaining explanations. AXIS asks learners to generate, revise, and evaluate explanations as they solve…

Economic explanations for concurrent sourcing

DEFF Research Database (Denmark)

Mols, Niels Peter

2010-01-01

Concurrent sourcing is a phenomenon where firms simultaneously make and buy the same good, i.e. they simultaneously use the governance modes of market and hierarchy. Though concurrent sourcing seems to be widespread, few studies of sourcing have focused on this phenomenon. This paper reviews...... different economic explanations for why firms use concurrent sourcing. The distinctive features of the explanations are compared, and it is discussed how they may serve as a springboard for research on concurrent sourcing. Managerial implications are also offered....

Consequentialism and the Synthetic Biology Problem.

Science.gov (United States)

Heavey, Patrick

2017-04-01

This article analyzes the ethics of synthetic biology (synbio) from a consequentialist perspective, examining potential effects on food and agriculture, and on medicine, fuel, and the advancement of science. The issues of biosafety and biosecurity are also examined. A consequentialist analysis offers an essential road map to policymakers and regulators as to how to deal with synbio. Additionally, the article discusses the limitations of consequentialism as a tool for analysing synbioethics. Is it possible to predict, with any degree of plausibility, what the consequences of synthetic biology will be in 50 years, or in 100, or in 500? Synbio may take humanity to a place of radical departure from what is known or knowable.

Evolutionary Explanations of Eating Disorders

Directory of Open Access Journals (Sweden)

Igor Kardum

2008-12-01

Full Text Available This article reviews several most important evolutionary mechanisms that underlie eating disorders. The first part clarifies evolutionary foundations of mental disorders and various mechanisms leading to their development. In the second part selective pressures and evolved adaptations causing contemporary epidemic of obesity as well as differences in dietary regimes and life-style between modern humans and their ancestors are described. Concerning eating disorders, a number of current evolutionary explanations of anorexia nervosa are presented together with their main weaknesses. Evolutionary explanations of eating disorders based on the reproductive suppression hypothesis and its variants derived from kin selection theory and the model of parental manipulation were elaborated. The sexual competition hypothesis of eating disorder, adapted to flee famine hypothesis as well as explanation based on the concept of social attention holding power and the need to belonging were also explained. The importance of evolutionary theory in modern conceptualization and research of eating disorders is emphasized.

The status of functional explanation in psychology: reduction and mechanistic explanation

NARCIS (Netherlands)

Gervais, H.; Looren De Jong, H.

2013-01-01

The validity of functional explanations as they are commonly used in psychology has recently come under attack. Kim's supervenience argument purports to prove that higher-level generalizations have no causal powers of their own, and hence are explanatorily irrelevant. In a nutshell, the

Changes in Students' Explanations for Gender Differences after Taking a Psychology of Women Class: More Constructionist and Less Essentialist

Science.gov (United States)

Yoder, Janice D.; Fischer, Ann R.; Kahn, Arnold S.; Groden, Jessica

2007-01-01

We explored how students' endorsements of essential (biological and personality) and constructed (socialization and contextual) explanations for gender differences changed from the start to the end of Psychology of Women (POW) classes along with their feminist attitudes. Results from surveys of 120 POW students from three universities indicated…

Application of E-infinity theory to biology

International Nuclear Information System (INIS)

He Jihuan

2006-01-01

Albert Einstein combined continuous space and time into his special relativity, El-Naschie discovered the transfinite discontinuity of space-time in his E-infinity theory where infinity of dimensions was created. We find a partner of both space-time and E-infinity in biology. In our theory, the number of cells in an organism endows an additional dimension in biology, leading to explanation of many complex phenomena

Unstable genes unstable mind: beyond the central dogma of molecular biology.

Science.gov (United States)

Hegde, Mahabaleshwar V; Saraph, Arundhati A

2011-08-01

Schizophrenia has a polygenic mode of inheritance and an estimated heritability of over 80%, but success in understanding its genetic underpinnings to date has been modest. Unlike in trinucleotide neurodegenerative disorders, the phenomenon of genetic anticipation observed in schizophrenia or bipolar disorder has not been explained. For the first time, we provide a plausible molecular explanation of genetic anticipation and pathophysiology of schizophrenia, at least in part, with supporting evidence. We postulate that abnormally increased numbers of CAG repeats in many genes being expressed in the brain, coding for glutamine, cumulatively press for higher demand of glutamine in the respective brain cells, resulting in a metabolic crisis and dysregulation of the glutamate-glutamine cycle. This can adversely affect the functioning of both glutamate and GABA receptors, which are known to be involved in psychosis, and may also affect glutathione levels, increasing oxidative stress. The resulting psychosis (gain in function), originating from unstable genes, is described as an effect "beyond the central dogma of molecular biology". The hypothesis explains genetic anticipation, as further expansions in subsequent generations may result in increased severity and earlier occurrence. Many other well described findings provide proof of concept. This is a testable hypothesis, does not deny any known facts and opens up new avenues of research. Copyright © 2011 Elsevier Ltd. All rights reserved.

From information processing to decisions: Formalizing and comparing psychologically plausible choice models.

Science.gov (United States)

Heck, Daniel W; Hilbig, Benjamin E; Moshagen, Morten

2017-08-01

Decision strategies explain how people integrate multiple sources of information to make probabilistic inferences. In the past decade, increasingly sophisticated methods have been developed to determine which strategy explains decision behavior best. We extend these efforts to test psychologically more plausible models (i.e., strategies), including a new, probabilistic version of the take-the-best (TTB) heuristic that implements a rank order of error probabilities based on sequential processing. Within a coherent statistical framework, deterministic and probabilistic versions of TTB and other strategies can directly be compared using model selection by minimum description length or the Bayes factor. In an experiment with inferences from given information, only three of 104 participants were best described by the psychologically plausible, probabilistic version of TTB. Similar as in previous studies, most participants were classified as users of weighted-additive, a strategy that integrates all available information and approximates rational decisions. Copyright © 2017 Elsevier Inc. All rights reserved.

L’Analyse du Risque Géopolitique: du Plausible au Probable

OpenAIRE

Adib Bencherif

2015-01-01

This paper is going to explore the logical process behind risk analysis, particularly in geopolitics. The main goal is to demonstrate the ambiguities behind risk calculation and to highlight the continuum between plausibility and probability in risk analysis. To demonstrate it, the author introduces two notions: the inference of abduction, often neglected in the social sciences literature, and the Bayesian calculation. Inspired by the works of Louise Amoore, this paper tries to go further by ...

The Radical Promise of Reformist Zeal: What Makes "Inquiry for Equity" Plausible?

Science.gov (United States)

Lashaw, Amanda

2010-01-01

Education reform movements often promise more than they deliver. Why are such promises plausible in light of seemingly perpetual education reform? Drawing on ethnographic fieldwork based in a nonprofit education reform organization, this article explores the appeal of popular notions about "using data to close the racial achievement…

Chemistry and biology by new multiple choice

International Nuclear Information System (INIS)

Seo, Hyeong Seok; Kim, Seong Hwan

2003-02-01

This book is divided into two parts, the first part is about chemistry, which deals with science of material, atom structure and periodic law, chemical combination and power between molecule, state of material and solution, chemical reaction and an organic compound. The second part give description of biology with molecule and cell, energy in cells and chemical synthesis, molecular biology and heredity, function on animal, function on plant and evolution and ecology. This book has explanation of chemistry and biology with new multiple choice.

Pupils' evaluation and generation of evidence and explanation in argumentation.

Science.gov (United States)

Glassner, Amnon; Weinstock, Michael; Neuman, Yair

2005-03-01

Studies on argument have found that participants tend to prefer explanations to evidence. This apparent bias toward explanation has been qualified recently by research that has found it to diminish with the availability of evidence. This study examines the use of explanation versus evidence in the context of argumentation with reference to the goals of particular argument situations. Seventy-nine eighth-grade pupils at a regular, urban middle school. The pupils read argumentation scenarios, each having the stated goal of either explaining or proving a claim. The pupils rated the degree to which each of two provided assertions (one a theoretical explanation, and the other evidence-based) helped achieve the goal of the argument. On a second task, the pupils chose which of the two assertions should be more effective in achieving the argument goal. On the third task, the pupils generated either an explanation or evidence for each of the argumentation scenarios. Pupils demonstrated sensitivity to the relative epistemic strength of explanation and evidence. They rated explanations as more advantageous in achieving the explanation goal, and evidence as more advantageous in achieving the proof goal. Conversely, however, when asked to generate or recall an explanation or evidence, pupils produced more explanations than evidence independent of the argumentation goal. The study refines the definition of argumentation context to include specific goals. Pupils were sensitive to the context of the argumentation situation (e.g.goals, availability of evidence). However, they appeared to have a disposition toward explanation when asked to produce an explanation or evidence-based justification.

Synthesis of nanoparticles and nanomaterials biological approaches

CERN Document Server

Abdullaeva, Zhypargul

2017-01-01

This book covers biological synthesis approaches for nanomaterials and nanoparticles, including introductory material on their structure, phase compositions and morphology, nanomaterials chemical, physical, and biological properties. The chapters of this book describe in sequence the synthesis of various nanoparticles by microorganisms, bacteria, yeast, algae, and actynomycetes; plant and plant extract-based synthesis; and green synthesis methods. Each chapter provides basic knowledge on the synthesis of nanomaterials, defines fundamental terms, and aims to build a solid foundation of knowledge, followed by explanations, examples, visual photographs, schemes, tables and illustrations. Each chapter also contains control questions, problem drills, as well as case studies that clarify theory and the explanations given in the text. This book is ideal for researchers and advanced graduate students in materials engineering, biotechnology, and nanotechnology fields. As a reference book this work is also appropriate ...

Explanation and Categorization: How "Why?" Informs "What?"

Science.gov (United States)

Lombrozo, Tania

2009-01-01

Recent theoretical and empirical work suggests that explanation and categorization are intimately related. This paper explores the hypothesis that explanations can help structure conceptual representations, and thereby influence the relative importance of features in categorization decisions. In particular, features may be differentially important…

Contrast normalization contributes to a biologically-plausible model of receptive-field development in primary visual cortex (V1)

Science.gov (United States)

Willmore, Ben D.B.; Bulstrode, Harry; Tolhurst, David J.

2012-01-01

Neuronal populations in the primary visual cortex (V1) of mammals exhibit contrast normalization. Neurons that respond strongly to simple visual stimuli – such as sinusoidal gratings – respond less well to the same stimuli when they are presented as part of a more complex stimulus which also excites other, neighboring neurons. This phenomenon is generally attributed to generalized patterns of inhibitory connections between nearby V1 neurons. The Bienenstock, Cooper and Munro (BCM) rule is a neural network learning rule that, when trained on natural images, produces model neurons which, individually, have many tuning properties in common with real V1 neurons. However, when viewed as a population, a BCM network is very different from V1 – each member of the BCM population tends to respond to the same dominant features of visual input, producing an incomplete, highly redundant code for visual information. Here, we demonstrate that, by adding contrast normalization into the BCM rule, we arrive at a neurally-plausible Hebbian learning rule that can learn an efficient sparse, overcomplete representation that is a better model for stimulus selectivity in V1. This suggests that one role of contrast normalization in V1 is to guide the neonatal development of receptive fields, so that neurons respond to different features of visual input. PMID:22230381

Generating Explanations for Internet-based Business Games

Directory of Open Access Journals (Sweden)

Martin Fischer

2007-06-01

Full Text Available It is widely established debriefing in business games is important and influences the students' learning performance. Most games only support game statistics instead of explaining solution paths. We suggest the automatic generation of explanations for internet-mediated business games to improve the debriefing quality. As a proof of concept we developed a prototype of an internet-based auction game embedding an open simulation model and an automatic explanation component helping students and teachers to analyse the decision making process. This paper describes the usefulness of automated explanations and the underlying generic software architecture.

Effects of a chemical imbalance causal explanation on individuals' perceptions of their depressive symptoms.

Science.gov (United States)

Kemp, Joshua J; Lickel, James J; Deacon, Brett J

2014-05-01

Although the chemical imbalance theory is the dominant causal explanation of depression in the United States, little is known about the effects of this explanation on depressed individuals. This experiment examined the impact of chemical imbalance test feedback on perceptions of stigma, prognosis, negative mood regulation expectancies, and treatment credibility and expectancy. Participants endorsing a past or current depressive episode received results of a bogus but credible biological test demonstrating their depressive symptoms to be caused, or not caused, by a chemical imbalance in the brain. Results showed that chemical imbalance test feedback failed to reduce self-blame, elicited worse prognostic pessimism and negative mood regulation expectancies, and led participants to view pharmacotherapy as more credible and effective than psychotherapy. The present findings add to a growing literature highlighting the unhelpful and potentially iatrogenic effects of attributing depressive symptoms to a chemical imbalance. Clinical and societal implications of these findings are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Generating explanations via analogical comparison.

Science.gov (United States)

Hoyos, Christian; Gentner, Dedre

2017-10-01

Generating explanations can be highly effective in promoting learning in both adults and children. Our interest is in the mechanisms that underlie this effect and in whether and how they operate in early learning. In adult reasoning, explanation may call on many subprocesses-including comparison, counterfactual reasoning, and reasoning by exclusion; but it is unlikely that all these processes are available to young children. We propose that one process that may serve both children and adults is comparison. In this study, we asked whether children would use the results of a comparison experience when asked to explain why a model skyscraper was stable. We focused on a challenging principle-that diagonal cross-bracing lends stability to physical structures (Gentner et al., Cognitive Science, 40, 224-240, 2016). Six-year-olds either received no training or interacted with model skyscrapers in one of three different conditions, designed to vary in their potential to invite and support comparison. In the Single Model condition, children interacted with a single braced model. In the comparison conditions (Low Alignability and High Alignability), children compared braced and unbraced models. Following experience with the models, children were asked to explain why the braced model was stable. They then received two transfer tasks. We found that children who received highly alignable pairs were most likely to (a) produce brace-based explanations and (b) transfer the brace principle to a dissimilar context. This provides evidence that children can benefit from analogical comparison in generating explanations and also suggests limitations on this ability.

5 CFR 1201.101 - Explanation and definitions.

Science.gov (United States)

2010-01-01

... definitions. (a) Explanation. An ex parte communication is an oral or written communication between a decision... outcome of a proceeding before the Board. (2) Decision-making official means any judge, officer or other... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Explanation and definitions. 1201.101...

Cognitive science as an interface between rational and mechanistic explanation.

Science.gov (United States)

Chater, Nick

2014-04-01

Cognitive science views thought as computation; and computation, by its very nature, can be understood in both rational and mechanistic terms. In rational terms, a computation solves some information processing problem (e.g., mapping sensory information into a description of the external world; parsing a sentence; selecting among a set of possible actions). In mechanistic terms, a computation corresponds to causal chain of events in a physical device (in engineering context, a silicon chip; in biological context, the nervous system). The discipline is thus at the interface between two very different styles of explanation--as the papers in the current special issue well illustrate, it explores the interplay of rational and mechanistic forces. Copyright © 2014 Cognitive Science Society, Inc.

The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence from Word Segmentation

Science.gov (United States)

Phillips, Lawrence; Pearl, Lisa

2015-01-01

The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's "cognitive plausibility." We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition…

Comparing early years and childhood experiences and outcomes in Scotland, England and three city-regions: a plausible explanation for Scottish 'excess' mortality?

Science.gov (United States)

Taulbut, Martin; Walsh, David; O'Dowd, John

2014-10-10

Negative early years and childhood experiences (EYCE), including socio-economic circumstances, parental health and parenting style, are associated with poor health outcomes both in childhood and adulthood. It has also been proposed that EYCE were historically worse in Scottish areas, especially Glasgow and the Clyde Valley, compared to elsewhere in the UK and that this variation can provide a partial explanation for the excess of ill health and mortality observed among those Scottish populations. Multiple logistic regression analysis was applied to two large, representative, British birth cohorts (the NCDS58 and the BCS70), to test the independent association of area of residence at ages 7 and 5 with risk of behavioural problems, respiratory problems and reading/vocabulary problems at the same age. Cohort members resident in Scotland were compared with those who were resident in England, while those resident in Glasgow and the Clyde Valley were compared with those resident in Merseyside and Greater Manchester. After adjustment for a range of relevant variables, the risk of adverse childhood outcomes was found to be either no different, or lower, in the Scottish areas. At a national level, the study reinforces the combined association of socio-economic circumstances, parental health (especially maternal mental health) and parenting with child health outcomes. Based on these samples, the study does not support the hypothesis that EYCE were worse in Scotland and Glasgow and the Clyde Valley. It seems, therefore (based on these data), less likely that the roots of the excess mortality observed in the Scottish areas can be explained by these factors.

Plausibility of stromal initiation of epithelial cancers without a mutation in the epithelium: a computer simulation of morphostats

Directory of Open Access Journals (Sweden)

Cappuccio Antonio

2009-03-01

Full Text Available Abstract Background There is experimental evidence from animal models favoring the notion that the disruption of interactions between stroma and epithelium plays an important role in the initiation of carcinogenesis. These disrupted interactions are hypothesized to be mediated by molecules, termed morphostats, which diffuse through the tissue to determine cell phenotype and maintain tissue architecture. Methods We developed a computer simulation based on simple properties of cell renewal and morphostats. Results Under the computer simulation, the disruption of the morphostat gradient in the stroma generated epithelial precursors of cancer without any mutation in the epithelium. Conclusion The model is consistent with the possibility that the accumulation of genetic and epigenetic changes found in tumors could arise after the formation of a founder population of aberrant cells, defined as cells that are created by low or insufficient morphostat levels and that no longer respond to morphostat concentrations. Because the model is biologically plausible, we hope that these results will stimulate further experiments.

Linguistic explanation and domain specialization: a case study in bound variable anaphora.

Science.gov (United States)

Adger, David; Svenonius, Peter

2015-01-01

The core question behind this Frontiers research topic is whether explaining linguistic phenomena requires appeal to properties of human cognition that are specialized to language. We argue here that investigating this issue requires taking linguistic research results seriously, and evaluating these for domain-specificity. We present a particular empirical phenomenon, bound variable interpretations of pronouns dependent on a quantifier phrase, and argue for a particular theory of this empirical domain that is couched at a level of theoretical depth which allows its principles to be evaluated for domain-specialization. We argue that the relevant principles are specialized when they apply in the domain of language, even if analogs of them are plausibly at work elsewhere in cognition or the natural world more generally. So certain principles may be specialized to language, though not, ultimately, unique to it. Such specialization is underpinned by ultimately biological factors, hence part of UG.

Reasoning in explanation-based decision making.

Science.gov (United States)

Pennington, N; Hastie, R

1993-01-01

A general theory of explanation-based decision making is outlined and the multiple roles of inference processes in the theory are indicated. A typology of formal and informal inference forms, originally proposed by Collins (1978a, 1978b), is introduced as an appropriate framework to represent inferences that occur in the overarching explanation-based process. Results from the analysis of verbal reports of decision processes are presented to demonstrate the centrality and systematic character of reasoning in a representative legal decision-making task.

A new explanation of the extinction paradox

International Nuclear Information System (INIS)

Berg, M.J.; Sorensen, C.M.; Chakrabarti, A.

2011-01-01

This work presents a new explanation for the extinction paradox and shows that the canonical explanations are incorrect. This paradox refers to the large size limit of a particle's extinction cross section. It is called a paradox because the geometrical optics approximation, which should be valid in this limit, predicts a cross section that is half of the true value. The new explanation is achieved by formulating the scattered wave in terms of an integral over the particle's surface where the seemingly unrelated Ewald-Oseen theorem appears in the formulation. By expressing the cross section in terms of this surface integral, the Ewald-Oseen theorem is analytically connected to the cross section. Several illustrations are used to reveal the significance of this connection: The paradox is seen to be a consequence of the requirement that the incident wave be canceled within the particle by secondary radiation from its own internal field. Following this, the canonical explanations are examined to reveal serious problems. In the process, the same asymptotic extinction behavior is shown to occur for small highly refractive dielectric particles, and thus is not just a large particle size or small wavelength effect as is often stated. The traditional explanations cannot account for this behavior while the new one actually predicts it. All in all, this work constitutes a fundamental reworking of 60 years of accepted understanding for the cause of the asymptotic behavior of the extinction cross section.

Re-orienting discussions of scientific explanation: A functional perspective.

Science.gov (United States)

Woody, Andrea I

2015-08-01

Philosophy of science offers a rich lineage of analysis concerning the nature of scientific explanation, but the vast majority of this work, aiming to provide an analysis of the relation that binds a given explanans to its corresponding explanandum, presumes the proper analytic focus rests at the level of individual explanations. There are, however, other questions we could ask about explanation in science, such as: What role(s) does explanatory practice play in science? Shifting focus away from explanations, as achievements, toward explaining, as a coordinated activity of communities, the functional perspective aims to reveal how the practice of explanatory discourse functions within scientific communities given their more comprehensive aims and practices. In this paper, I outline the functional perspective, argue that taking the functional perspective can reveal important methodological roles for explanation in science, and consequently, that beginning here provides resources for developing more adequate responses to traditional concerns. In particular, through an examination of the ideal gas law, I emphasize the normative status of explanations within scientific communities and discuss how such status underwrites a compelling rationale for explanatory power as a theoretical virtue. Copyright © 2015 Elsevier Ltd. All rights reserved.

Children's success at detecting circular explanations and their interest in future learning.

Science.gov (United States)

Mills, Candice M; Danovitch, Judith H; Rowles, Sydney P; Campbell, Ian L

2017-10-01

These studies explore elementary-school-aged children's ability to evaluate circular explanations and whether they respond to receiving weak explanations by expressing interest in additional learning. In the first study, 6-, 8-, and 10-year-olds (n = 53) heard why questions about unfamiliar animals. For each question, they rated the quality of single explanations and later selected the best explanation between pairs of circular and noncircular explanations. When judging single explanations, 8- and 10-year-olds, and to some extent 6-year-olds, provided higher ratings for noncircular explanations compared to circular ones. When selecting between pairs of explanations, all age groups preferred noncircular explanations to circular ones, but older children did so more consistently than 6-year-olds. Children who recognized the weakness of the single circular explanations were more interested in receiving additional information about the question topics. In Study 2, all three age groups (n = 87) provided higher ratings for noncircular explanations compared to circular ones when listening to responses to how questions, but older children showed a greater distinction in their ratings than 6-year-olds. Moreover, the link between recognizing circular explanations as weak and interest in future learning could not be accounted for solely by individual differences in verbal intelligence. These findings illustrate the developmental trajectory of explanation evaluation and support that recognition of weak explanations is linked to interest in future learning across the elementary years. Implications for education are discussed.

Down's syndrome in the Lothian region of Scotland - 1978 to 1989

International Nuclear Information System (INIS)

Ramsay, C.N.; Ellis, P.M.; Zealley, H.

1991-01-01

A study of Down's syndrome in Lothian for the years 1978-1989 revealed a significantly higher than expected incidence of cases in 1987. The increased incidence was particularly significant among women aged 35 years or more. The increase could not be attributed to demographic changes on birth rates or to the age distribution of the women concerned. A temporal association between the cluster of cases and the events at Chernobyl in April 1986 was demonstrated. However, according to current understanding, there is no biologically plausible explanation to link the 2 events, given the reported levels of radioactive fallout in the Lothian region, resulting from the Chernobyl disaster. An explanation for the increased incidence of Down's syndrome in 1987 remains outstanding

Social class, sense of control, and social explanation.

Science.gov (United States)

Kraus, Michael W; Piff, Paul K; Keltner, Dacher

2009-12-01

Lower social class is associated with diminished resources and perceived subordinate rank. On the basis of this analysis, the authors predicted that social class would be closely associated with a reduced sense of personal control and that this association would explain why lower class individuals favor contextual over dispositional explanations of social events. Across 4 studies, lower social class individuals, as measured by subjective socioeconomic status (SES), endorsed contextual explanations of economic trends, broad social outcomes, and emotion. Across studies, the sense of control mediated the relation between subjective SES and contextual explanations, and this association was independent of objective SES, ethnicity, political ideology, and self-serving biases. Finally, experimentally inducing a higher sense of control attenuated the tendency for lower subjective SES individuals to make more contextual explanations (Study 4). Implications for future research on social class as well as theoretical distinctions between objective SES and subjective SES are discussed.

Biological design in science classrooms

Science.gov (United States)

Scott, Eugenie C.; Matzke, Nicholas J.

2007-01-01

Although evolutionary biology is replete with explanations for complex biological structures, scientists concerned about evolution education have been forced to confront “intelligent design” (ID), which rejects a natural origin for biological complexity. The content of ID is a subset of the claims made by the older “creation science” movement. Both creationist views contend that highly complex biological adaptations and even organisms categorically cannot result from natural causes but require a supernatural creative agent. Historically, ID arose from efforts to produce a form of creationism that would be less vulnerable to legal challenges and that would not overtly rely upon biblical literalism. Scientists do not use ID to explain nature, but because it has support from outside the scientific community, ID is nonetheless contributing substantially to a long-standing assault on the integrity of science education. PMID:17494747

The relativity of biological function.

Science.gov (United States)

Laubichler, Manfred D; Stadler, Peter F; Prohaska, Sonja J; Nowick, Katja

2015-12-01

Function is a central concept in biological theories and explanations. Yet discussions about function are often based on a narrow understanding of biological systems and processes, such as idealized molecular systems or simple evolutionary, i.e., selective, dynamics. Conflicting conceptions of function continue to be used in the scientific literature to support certain claims, for instance about the fraction of "functional DNA" in the human genome. Here we argue that all biologically meaningful interpretations of function are necessarily context dependent. This implies that they derive their meaning as well as their range of applicability only within a specific theoretical and measurement context. We use this framework to shed light on the current debate about functional DNA and argue that without considering explicitly the theoretical and measurement contexts all attempts to integrate biological theories are prone to fail.

Is knowing believing? The role of event plausibility and background knowledge in planting false beliefs about the personal past.

Science.gov (United States)

Pezdek, Kathy; Blandon-Gitlin, Iris; Lam, Shirley; Hart, Rhiannon Ellis; Schooler, Jonathan W

2006-12-01

False memories are more likely to be planted for plausible than for implausible events, but does just knowing about an implausible event make individuals more likely to think that the event happened to them? Two experiments assessed the independent contributions o f plausibility a nd background knowledge to planting false beliefs. In Experiment 1, subjects rated 20 childhood events as to the likelihood of each event having happened to them. The list included the implausible target event "received an enema," a critical target event of Pezdek, Finger, and Hodge (1997). Two weeks later, subjects were presented with (1) information regarding the high prevalence rate of enemas; (2) background information on how to administer an enema; (3) neither type of information; or (4) both. Immediately or 2 weeks later, they rated the 20 childhood events again. Only plausibility significantly increased occurrence ratings. In Experiment 2, the target event was changed from "barium enema administered in a hospital" to "home enema for constipation"; significant effects of both plausibility and background knowledge resulted. The results suggest that providing background knowledge can increase beliefs about personal events, but that its impact is limited by the extent of the individual's familiarity with the context of the suggested target event.

Explanation and teleology in Aristotle's Philosophy of Nature

NARCIS (Netherlands)

Leunissen, Mariska Elisabeth Maria Philomena Johannes

2007-01-01

This dissertation explores Aristotle’s use of teleology as a principle of explanation, especially as it is used in the natural treatises. Its main purposes are, first, to determine the function, structure, and explanatory power of teleological explanations in four of Aristotle’s natural treatises,

The many roles of "explanation" in science education: a case study

Science.gov (United States)

Rocksén, Miranda

2016-12-01

In this paper the role of explanations is discussed in relation to possible consequences originating in the polysemy of the word explanation. The present study is a response to conceptual confusions that have arisen in the intersection between theory and practice, and between science education literature and communication in authentic science classroom settings. Science classroom communication is examined in terms of one teacher's word use during eleven lessons about evolution. The study contributes empirical examples of how disciplinary norms of valid explanations are manifested in science classroom communication. A dialogical analysis shows how the teacher provides three conversational structures: asking for acts of explanation, providing opportunities to talk about what explanations are in this context and providing opportunities to talk about explanations constructed by students. These three structures facilitate the process of learning how to evaluate and justify explanations. Three potential meanings of the word "explanation" are pointed to: an everyday meaning, a pedagogical-professional meaning and a scientific meaning of the word. It is suggested that the co-existence of these three potential meanings has communicative consequences in science education.

Investigating Lebanese Grade Seven Biology Teachers Mathematical Knowledge and Skills: A Case Study

Science.gov (United States)

Raad, Nawal Abou; Chatila, Hanadi

2016-01-01

This paper investigates Lebanese grade 7 biology teachers' mathematical knowledge and skills, by exploring how they explain a visual representation in an activity depending on the mathematical concept "Function". Twenty Lebanese in-service biology teachers participated in the study, and were interviewed about their explanation for the…

Teacher Explanation of Physics Concepts: A Video Study

Science.gov (United States)

Geelan, David

2013-01-01

Video recordings of Year 11 physics lessons were analyzed to identify key features of teacher explanations. Important features of the explanations used included teachers' ability to move between qualitative and quantitative modes of discussion, attention to what students require to succeed in high stakes examinations, thoughtful use of…

Promoting Vicarious Learning of Physics Using Deep Questions with Explanations

Science.gov (United States)

Craig, Scotty D.; Gholson, Barry; Brittingham, Joshua K.; Williams, Joah L.; Shubeck, Keith T.

2012-01-01

Two experiments explored the role of vicarious "self" explanations in facilitating student learning gains during computer-presented instruction. In Exp. 1, college students with low or high knowledge on Newton's laws were tested in four conditions: (a) monologue (M), (b) questions (Q), (c) explanation (E), and (d) question + explanation (Q + E).…

Simple explanations and reasoning: From philosophy of science to expert systems

Science.gov (United States)

Rochowiak, Daniel

1988-01-01

A preliminary prototype of a simple explanation system was constructed. Although the system, based on the idea of storytelling, did not incorporate all of the principles of simple explanation, it did demonstrate the potential of the approach. The system incorporated a hypertext system, an inference engine, and facilities for constructing contrast type explanations. The continued development of such a system should prove to be valuable. By extending the resources of the expert system paradigm, the knowledge engineer is not forced to learn a new set of skills, and the domain knowledge already acquired by him is not lost. Further, both the beginning user and the more advanced user can be accommodated. For the beginning user, corrective explanations and ES explanations provide facilities for more clearly understanding the way in which the system is functioning. For the more advanced user, the instance and state explanations allow him to focus on the issues at hand. The simple model of explanation attempts to exploit and show how the why and how facilities of the expert system paradigm can be extended by attending to the pragmatics of explanation and adding texture to the ordinary pattern of reasoning in a rule based system.

Algorithms and Their Explanations

NARCIS (Netherlands)

Benini, M.; Gobbo, F.; Beckmann, A.; Csuhaj-Varjú, E.; Meer, K.

2014-01-01

By analysing the explanation of the classical heapsort algorithm via the method of levels of abstraction mainly due to Floridi, we give a concrete and precise example of how to deal with algorithmic knowledge. To do so, we introduce a concept already implicit in the method, the ‘gradient of

Resolution of cosmological singularity and a plausible mechanism of the big bang

International Nuclear Information System (INIS)

Choudhury, D.C.

2002-01-01

The initial cosmological singularity in the framework of the general theory of relativity is resolved by introducing the effect of the uncertainty principle of quantum theory without violating conventional laws of physics. A plausible account of the mechanism of the big bang, analogous to that of a nuclear explosion, is given and the currently accepted Planck temperature of ≅10 32 K at the beginning of the big bang is predicted

Synthetic Biology: Engineering Living Systems from Biophysical Principles.

Science.gov (United States)

Bartley, Bryan A; Kim, Kyung; Medley, J Kyle; Sauro, Herbert M

2017-03-28

Synthetic biology was founded as a biophysical discipline that sought explanations for the origins of life from chemical and physical first principles. Modern synthetic biology has been reinvented as an engineering discipline to design new organisms as well as to better understand fundamental biological mechanisms. However, success is still largely limited to the laboratory and transformative applications of synthetic biology are still in their infancy. Here, we review six principles of living systems and how they compare and contrast with engineered systems. We cite specific examples from the synthetic biology literature that illustrate these principles and speculate on their implications for further study. To fully realize the promise of synthetic biology, we must be aware of life's unique properties. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Self-Explanation and Explanatory Feedback in Games: Individual Differences, Gameplay, and Learning

Science.gov (United States)

Killingsworth, Stephen S.; Clark, Douglas B.; Adams, Deanne M.

2015-01-01

Previous research has demonstrated the efficacy of two explanation-based approaches for increasing learning in educational games. The first involves asking students to explain their answers (self-explanation) and the second involves providing correct explanations (explanatory feedback). This study (1) compared self-explanation and explanatory…

Bothered by abstractness or engaged by cohesion? Experts' explanations enhance novices' deep-learning.

Science.gov (United States)

Lachner, Andreas; Nückles, Matthias

2015-03-01

Experts' explanations have been shown to better enhance novices' transfer as compared with advanced students' explanations. Based on research on expertise and text comprehension, we investigated whether the abstractness or the cohesion of experts' and intermediates' explanations accounted for novices' learning. In Study 1, we showed that the superior cohesion of experts' explanations accounted for most of novices' transfer, whereas the degree of abstractness did not impact novices' transfer performance. In Study 2, we investigated novices' processing while learning with experts' and intermediates' explanations. We found that novices studying experts' explanations actively self-regulated their processing of the explanations, as they showed mainly deep-processing activities, whereas novices learning with intermediates' explanations were mainly engaged in shallow-processing activities by paraphrasing the explanations. Thus, we concluded that subject-matter expertise is a crucial prerequisite for instructors. Despite the abstract character of experts' explanations, their subject-matter expertise enables them to generate highly cohesive explanations that serve as a valuable scaffold for students' construction of flexible knowledge by engaging them in deep-level processing. PsycINFO Database Record (c) 2015 APA, all rights reserved.

The Limits of Materialism: Auspicious for Teleological Explanation?

Science.gov (United States)

Athearn, Daniel

2012-09-01

The idea that scientific explanation runs up against certain inherent limits beyond which the field is open for other kinds of explanation is based on flawed assumptions. Modern physical knowledge, as I read it, does contain at least one important implication for theology having to do with how "Creation" is understood, if indeed the term remains usable and suitable.

Reasoning with alternative explanations in physics: The cognitive accessibility rule

Science.gov (United States)

Heckler, Andrew F.; Bogdan, Abigail M.

2018-06-01

A critical component of scientific reasoning is the consideration of alternative explanations. Recognizing that decades of cognitive psychology research have demonstrated that relative cognitive accessibility, or "what comes to mind," strongly affects how people reason in a given context, we articulate a simple "cognitive accessibility rule", namely that alternative explanations are considered less frequently when an explanation with relatively high accessibility is offered first. In a series of four experiments, we test the cognitive accessibility rule in the context of consideration of alternative explanations for six physical scenarios commonly found in introductory physics curricula. First, we administer free recall and recognition tasks to operationally establish and distinguish between the relative accessibility and availability of common explanations for the physical scenarios. Then, we offer either high or low accessibility explanations for the physical scenarios and determine the extent to which students consider alternatives to the given explanations. We find two main results consistent across algebra- and calculus-based university level introductory physics students for multiple answer formats. First, we find evidence that, at least for some contexts, most explanatory factors are cognitively available to students but not cognitively accessible. Second, we empirically verify the cognitive accessibility rule and demonstrate that the rule is strongly predictive, accounting for up to 70% of the variance of the average student consideration of alternative explanations across scenarios. Overall, we find that cognitive accessibility can help to explain biases in the consideration of alternatives in reasoning about simple physical scenarios, and these findings lend support to the growing number of science education studies demonstrating that tasks relevant to science education curricula often involve rapid, automatic, and potentially predictable processes and

Metastasis in renal cell carcinoma: Biology and implications for therapy

Directory of Open Access Journals (Sweden)

Jun Gong

2016-10-01

Full Text Available Although multiple advances have been made in systemic therapy for renal cell carcinoma (RCC, metastatic RCC remains incurable. In the current review, we focus on the underlying biology of RCC and plausible mechanisms of metastasis. We further outline evolving strategies to combat metastasis through adjuvant therapy. Finally, we discuss clinical patterns of metastasis in RCC and how distinct systemic therapy approaches may be considered based on the anatomic location of metastasis.

Explanation-based learning in infancy.

Science.gov (United States)

Baillargeon, Renée; DeJong, Gerald F

2017-10-01

In explanation-based learning (EBL), domain knowledge is leveraged in order to learn general rules from few examples. An explanation is constructed for initial exemplars and is then generalized into a candidate rule that uses only the relevant features specified in the explanation; if the rule proves accurate for a few additional exemplars, it is adopted. EBL is thus highly efficient because it combines both analytic and empirical evidence. EBL has been proposed as one of the mechanisms that help infants acquire and revise their physical rules. To evaluate this proposal, 11- and 12-month-olds (n = 260) were taught to replace their current support rule (that an object is stable when half or more of its bottom surface is supported) with a more sophisticated rule (that an object is stable when half or more of the entire object is supported). Infants saw teaching events in which asymmetrical objects were placed on a base, followed by static test displays involving a novel asymmetrical object and a novel base. When the teaching events were designed to facilitate EBL, infants learned the new rule with as few as two (12-month-olds) or three (11-month-olds) exemplars. When the teaching events were designed to impede EBL, however, infants failed to learn the rule. Together, these results demonstrate that even infants, with their limited knowledge about the world, benefit from the knowledge-based approach of EBL.

Why the Difference Between Explanation and Argument Matters to Science Education

Science.gov (United States)

Brigandt, Ingo

2016-05-01

Contributing to the recent debate on whether or not explanations ought to be differentiated from arguments, this article argues that the distinction matters to science education. I articulate the distinction in terms of explanations and arguments having to meet different standards of adequacy. Standards of explanatory adequacy are important because they correspond to what counts as a good explanation in a science classroom, whereas a focus on evidence-based argumentation can obscure such standards of what makes an explanation explanatory. I provide further reasons for the relevance of not conflating explanations with arguments (and having standards of explanatory adequacy in view). First, what guides the adoption of the particular standards of explanatory adequacy that are relevant in a scientific case is the explanatory aim pursued in this context. Apart from explanatory aims being an important aspect of the nature of science, including explanatory aims in classroom instruction also promotes students seeing explanations as more than facts, and engages them in developing explanations as responses to interesting explanatory problems. Second, it is of relevance to science curricula that science aims at intervening in natural processes, not only for technological applications, but also as part of experimental discovery. Not any argument enables intervention in nature, as successful intervention specifically presupposes causal explanations. Students can fruitfully explore in the classroom how an explanatory account suggests different options for intervention.

Reasoning through Instructional Analogies

Science.gov (United States)

Kapon, Shulamit; diSessa, Andrea A.

2012-01-01

This article aims to account for students' assessments of the plausibility and applicability of analogical explanations, and individual differences in these assessments, by analyzing properties of students' underlying knowledge systems. We developed a model of explanation and change in explanation focusing on knowledge elements that provide a…

Radiation biology and radiation therapy

International Nuclear Information System (INIS)

Wideroee, R.

1975-01-01

Radiation biology and radiation therapy can be compared with investigations in different layers of earth. Radiation biology works upwards from the elementary foundations, therapy works downwards with roots to secure and improve the clinical 'surface work'. The Ellis formula (Strandquist), which is a collection of clinical experience, is suited to form connections with radiobiology in the middle layers, and cooperation can give impulses for research. The structure and conditions of tumours and the complicated problems met with are discussed, based on the Carmel symposium of 1969. The oxygen problem in anoxic tumours is not yet solved. Experimental investigations of the effect itself give partly contradictory results. From a clinical viewpoint reoxygenation is of the utmost significance for obtaining control over the primary tumour, and advanced irradiation programmes will here give better results than the traditional ones. New chemicals, e.g. R 0 -07-0582, appear to reduce the OER value to 1.5, thereby making neutron therapy superfluous. Finally a problem from fundamental research is dealt with, wherein two hypotheses explaining the β-effect are described. The repair hypothesis gives a simple explanation but leaves many questions unanswered. The other hypothesis explains the β-effect as two neighbouring single breaks of the DNA molecule. It still presents difficulties, and is scarcely the correct explanation. (JIW)

Vulnerabilities to agricultural production shocks: An extreme, plausible scenario for assessment of risk for the insurance sector

Directory of Open Access Journals (Sweden)

Tobias Lunt

2016-01-01

Full Text Available Climate risks pose a threat to the function of the global food system and therefore also a hazard to the global financial sector, the stability of governments, and the food security and health of the world’s population. This paper presents a method to assess plausible impacts of an agricultural production shock and potential materiality for global insurers. A hypothetical, near-term, plausible, extreme scenario was developed based upon modules of historical agricultural production shocks, linked under a warm phase El Niño-Southern Oscillation (ENSO meteorological framework. The scenario included teleconnected floods and droughts in disparate agricultural production regions around the world, as well as plausible, extreme biotic shocks. In this scenario, global crop yield declines of 10% for maize, 11% for soy, 7% for wheat and 7% for rice result in quadrupled commodity prices and commodity stock fluctuations, civil unrest, significant negative humanitarian consequences and major financial losses worldwide. This work illustrates a need for the scientific community to partner across sectors and industries towards better-integrated global data, modeling and analytical capacities, to better respond to and prepare for concurrent agricultural failure. Governments, humanitarian organizations and the private sector collectively may recognize significant benefits from more systematic assessment of exposure to agricultural climate risk.

Scientific explanations in Greek upper secondary physics textbooks

Science.gov (United States)

Velentzas, Athanasios; Halkia, Krystallia

2018-01-01

In this study, an analysis of the structure of scientific explanations included in physics textbooks of upper secondary schools in Greece was completed. In scientific explanations for specific phenomena found in the sample textbooks, the explanandum is a logical consequence of the explanans, which in all cases include at least one scientific law (and/or principle, model or rule) previously presented, as well as statements concerning a specific case or specific conditions. The same structure is also followed in most of the cases in which the textbook authors explain regularities (i.e. laws, rules) as consequences of one or more general law or principle of physics. Finally, a number of the physics laws and principles presented in textbooks are not deduced as consequences from other, more general laws, but they are formulated axiomatically or inductively derived and the authors argue for their validity. Since, as it was found, the scientific explanations presented in the textbooks used in the study have similar structures to the explanations in internationally known textbooks, the findings of the present work may be of interest not only to science educators in Greece, but also to the community of science educators in other countries.

Explanation for the Mystical Practice III.

Directory of Open Access Journals (Sweden)

Květoslav Minařík

2016-11-01

Full Text Available Concentration on feet and legs as a whole, with a special focus on their flesh, has an effect on the development of the intellect and deepening of the sensory discernment, because right here, in the legs, in the flesh of the body, the basis of the inner life is situated. The same concentration with a special focus on their bones – and in particular to the bones of knees – eliminates the instability of the usual attention; it is used to stabilize the entire inner life. The current article is a continuation of Explanation for the Mystical Practice I. and Explanation for the Mystical Practice II., published in the previous editions of Spirituality Studies.

Sublime Views and Beautiful Explanations

DEFF Research Database (Denmark)

Barry, Daved; Meisiek, Stefan; Hatch, Mary Jo

To create a generative theory that provides beautiful explanations and sublime views requires both a crafts and an art approach to scientific theorizing. The search for generativity leads scholars to perform various theorizing moves between the confines of simple, yet eloquent beauty...

Morality Principles for Risk Modelling: Needs and Links with the Origins of Plausible Inference

Science.gov (United States)

Solana-Ortega, Alberto; Solana, Vicente

2009-12-01

In comparison with the foundations of probability calculus, the inescapable and controversial issue of how to assign probabilities has only recently become a matter of formal study. The introduction of information as a technical concept was a milestone, but the most promising entropic assignment methods still face unsolved difficulties, manifesting the incompleteness of plausible inference theory. In this paper we examine the situation faced by risk analysts in the critical field of extreme events modelling, where the former difficulties are especially visible, due to scarcity of observational data, the large impact of these phenomena and the obligation to assume professional responsibilities. To respond to the claim for a sound framework to deal with extremes, we propose a metafoundational approach to inference, based on a canon of extramathematical requirements. We highlight their strong moral content, and show how this emphasis in morality, far from being new, is connected with the historic origins of plausible inference. Special attention is paid to the contributions of Caramuel, a contemporary of Pascal, unfortunately ignored in the usual mathematical accounts of probability.

Plausible scenarios for the radiography profession in Sweden in 2025

International Nuclear Information System (INIS)

Björkman, B.; Fridell, K.; Tavakol Olofsson, P.

2017-01-01

Introduction: Radiography is a healthcare speciality with many technical challenges. Advances in engineering and information technology applications may continue to drive and be driven by radiographers. The world of diagnostic imaging is changing rapidly and radiographers must be proactive in order to survive. To ensure sustainable development, organisations have to identify future opportunities and threats in a timely manner and incorporate them into their strategic planning. Hence, the aim of this study was to analyse and describe plausible scenarios for the radiography profession in 2025. Method: The study has a qualitative design with an inductive approach based on focus group interviews. The interviews were inspired by the Scenario-Planning method. Results: Of the seven trends identified in a previous study, the radiographers considered two as the most uncertain scenarios that would have the greatest impact on the profession should they occur. These trends, labelled “Access to career advancement” and “A sufficient number of radiographers”, were inserted into the scenario cross. The resulting four plausible future scenarios were: The happy radiographer, the specialist radiographer, the dying profession and the assembly line. Conclusion: It is suggested that “The dying profession” scenario could probably be turned in the opposite direction by facilitating career development opportunities for radiographers within the profession. Changing the direction would probably lead to a profession composed of “happy radiographers” who are specialists, proud of their profession and competent to carry out advanced tasks, in contrast to being solely occupied by “the assembly line”. - Highlights: • The world of radiography is changing rapidly and radiographers must be proactive in order to survive. • Future opportunities and threats should be identified and incorporated into the strategic planning. • Appropriate actions can probably change the

Self-Explanation and Explanatory Feedback in Games: Individual Differences, Gameplay, and Learning

OpenAIRE

Killingsworth, Stephen; Clark, Douglas; Adams, Deanne

2015-01-01

Previous research has demonstrated the efficacy of two explanation-based approaches for increasing learning in educational games. The first involves asking students to explain their answers (self-explanation) and the second involves providing correct explanations (explanatory feedback). This study (1) compared self-explanation and explanatory feedback features embedded into a game designed to teach Newtonian dynamics and (2) investigated relationships between learning and individual differenc...

Ultimate and proximate explanations of strong reciprocity.

Science.gov (United States)

Vromen, Jack

2017-08-23

Strong reciprocity (SR) has recently been subject to heated debate. In this debate, the "West camp" (West et al. in Evol Hum Behav 32(4):231-262, 2011), which is critical of the case for SR, and the "Laland camp" (Laland et al. in Science, 334(6062):1512-1516, 2011, Biol Philos 28(5):719-745, 2013), which is sympathetic to the case of SR, seem to take diametrically opposed positions. The West camp criticizes advocates of SR for conflating proximate and ultimate causation. SR is said to be a proximate mechanism that is put forward by its advocates as an ultimate explanation of human cooperation. The West camp thus accuses advocates of SR for not heeding Mayr's original distinction between ultimate and proximate causation. The Laland camp praises advocates of SR for revising Mayr's distinction. Advocates of SR are said to replace Mayr's uni-directional view on the relation between ultimate and proximate causes by the bi-directional one of reciprocal causation. The paper argues that both the West camp and the Laland camp misrepresent what advocates of SR are up to. The West camp is right that SR is a proximate cause of human cooperation. But rather than putting forward SR as an ultimate explanation, as the West camp argues, advocates of SR believe that SR itself is in need of ultimate explanation. Advocates of SR tend to take gene-culture co-evolutionary theory as the correct meta-theoretical framework for advancing ultimate explanations of SR. Appearances notwithstanding, gene-culture coevolutionary theory does not imply Laland et al.'s notion of reciprocal causation. "Reciprocal causation" suggests that proximate and ultimate causes interact simultaneously, while advocates of SR assume that they interact sequentially. I end by arguing that the best way to understand the debate is by disambiguating Mayr's ultimate-proximate distinction. I propose to reserve "ultimate" and "proximate" for different sorts of explanations, and to use other terms for distinguishing

Resolution of Cosmological Singularity and a Plausible Mechanism of the Big Bang

OpenAIRE

Choudhury, D. C.

2001-01-01

The initial cosmological singularity in the framework of the general theory of relativity is resolved by introducing the effect of the uncertainty principle of quantum theory without violating conventional laws of physics. A plausible account of the mechanism of the big bang, analogous to that of a nuclear explosion, is given and the currently accepted Planck temperature of about 10^(32)K at the beginning of the big bang is predicted. Subj-class: cosmology: theory-pre-big bang; mechanism of t...

The metaphysical lessons of synthetic biology and neuroscience.

Science.gov (United States)

Baertschi, Bernard

2015-01-01

In this paper, I examine some important metaphysical lessons that are often presented as derived from two new scientific disciplines: synthetic biology and neuroscience. I analyse four of them: the nature of life, the existence of a soul (the mind-body problem), personhood, and free will. Many caveats are in order, and each 'advance' or each case should be assessed for itself. I conclude that a main lesson can nevertheless be learned: in conjunction with modern science, neuroscience and synthetic biology allow us to enrich old metaphysical debates, to deepen and even renew them. In particular, it becomes less and less plausible to consider life, mind, person, and agency as non-natural or non-physical entities. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Explanations and expectations

DEFF Research Database (Denmark)

Järvinen, Margaretha; Ravn, Signe

2015-01-01

drug use ‘aetiologies’ drawn upon by the interviewees. These cover childhood experiences, self-medication, the influence of friends and cannabis use as a specific lifestyle. A central argument of the article is that these explanations not only concern the past but also point towards the future......This article analyses how young people enrolled in drug addiction treatment in Copenhagen, Denmark, explain their cannabis careers and how they view their possibilities for quitting drug use again. Inspired by Mead and narrative studies of health and illness, the article identifies four different...

Mind the gap! Automated concept map feedback supports students in writing cohesive explanations.

Science.gov (United States)

Lachner, Andreas; Burkhart, Christian; Nückles, Matthias

2017-03-01

Many students are challenged with the demand of writing cohesive explanations. To support students in writing cohesive explanations, we developed a computer-based feedback tool that visualizes cohesion deficits of students' explanations in a concept map. We conducted three studies to investigate the effectiveness of such feedback as well as the underlying cognitive processes. In Study 1, we found that the concept map helped students identify potential cohesion gaps in their drafts and plan remedial revisions. In Study 2, students with concept map feedback conducted revisions that resulted in more locally and globally cohesive, and also more comprehensible, explanations than the explanations of students who revised without concept map feedback. In Study 3, we replicated the findings of Study 2 by and large. More importantly, students who had received concept map feedback on a training explanation 1 week later wrote a transfer explanation without feedback that was more cohesive than the explanation of students who had received no feedback on their training explanation. The automated concept map feedback appears to particularly support the evaluation phase of the revision process. Furthermore, the feedback enabled novice writers to acquire sustainable skills in writing cohesive explanations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cultural variances in composition of biological and supernatural concepts of death: a content analysis of children's literature.

Science.gov (United States)

Lee, Ji Seong; Kim, Eun Young; Choi, Younyoung; Koo, Ja Hyouk

2014-01-01

Children's reasoning about the afterlife emerges naturally as a developmental regularity. Although a biological understanding of death increases in accordance with cognitive development, biological and supernatural explanations of death may coexist in a complementary manner, being deeply imbedded in cultural contexts. This study conducted a content analysis of 40 children's death-themed picture books in Western Europe and East Asia. It can be inferred that causality and non-functionality are highly integrated with the naturalistic and supernatural understanding of death in Western Europe, whereas the literature in East Asia seems to rely on naturalistic aspects of death and focuses on causal explanations.

Towards an Explanation Generation System for Robots: Analysis and Recommendations

Directory of Open Access Journals (Sweden)

Ben Meadows

2016-10-01

Full Text Available A fundamental challenge in robotics is to reason with incomplete domain knowledge to explain unexpected observations and partial descriptions extracted from sensor observations. Existing explanation generation systems draw on ideas that can be mapped to a multidimensional space of system characteristics, defined by distinctions, such as how they represent knowledge and if and how they reason with heuristic guidance. Instances in this multidimensional space corresponding to existing systems do not support all of the desired explanation generation capabilities for robots. We seek to address this limitation by thoroughly understanding the range of explanation generation capabilities and the interplay between the distinctions that characterize them. Towards this objective, this paper first specifies three fundamental distinctions that can be used to characterize many existing explanation generation systems. We explore and understand the effects of these distinctions by comparing the capabilities of two systems that differ substantially along these axes, using execution scenarios involving a robot waiter assisting in seating people and delivering orders in a restaurant. The second part of the paper uses this study to argue that the desired explanation generation capabilities corresponding to these three distinctions can mostly be achieved by exploiting the complementary strengths of the two systems that were explored. This is followed by a discussion of the capabilities related to other major distinctions to provide detailed recommendations for developing an explanation generation system for robots.

High School Students' Evaluations, Plausibility (Re) Appraisals, and Knowledge about Topics in Earth Science

Science.gov (United States)

Lombardi, Doug; Bickel, Elliot S.; Bailey, Janelle M.; Burrell, Shondricka

2018-01-01

Evaluation is an important aspect of science and is receiving increasing attention in science education. The present study investigated (1) changes to plausibility judgments and knowledge as a result of a series of instructional scaffolds, called model-evidence link activities, that facilitated evaluation of scientific and alternative models in…

The Biology of Intron Gain and Loss

DEFF Research Database (Denmark)

Jeffares, Daniel C; Mourier, Tobias; Penny, David

2006-01-01

Intron density in eukaryote genomes varies by more than three orders of magnitude, so there must have been extensive intron gain and/or intron loss during evolution. A favored and partial explanation for this range of intron densities has been that introns have accumulated stochastically in large...... on introns depending on the biology of the organism and the gene involved....

Mind and Meaning: Piaget and Vygotsky on Causal Explanation.

Science.gov (United States)

Beilin, Harry

1996-01-01

Piaget's theory has been characterized as descriptive and not explanatory, not qualifying as causal explanation. Piaget was consistent in showing how his theory was both explanatory and causal. Vygotsky also endorsed causal-genetic explanation but, on the basis of knowledge of only Piaget's earliest works, he claimed that Piaget's theory was not…

How to Program a Domain Independent Tracer for Explanations

Science.gov (United States)

Ishizaka, Alessio; Lusti, Markus

2006-01-01

Explanations are essential in the teaching process. Tracers are one possibility to provide students with explanations in an intelligent tutoring system. Their development can be divided into four steps: (a) the definition of the trace model; (b) the extraction of the information from this model; (c) the analysis and abstraction of the extracted…

Particle physics explanations for ultra-high energy cosmic ray events

Indian Academy of Sciences (India)

this talk I briefly summarize several proposed particle physics explanations: a breakdown ... as primaries, and magnetic monopoles with mass below 1010 GeV as primaries. .... these monopoles would be the ultimate test of this explanation.

Neural correlates of early-closure garden-path processing: Effects of prosody and plausibility.

Science.gov (United States)

den Ouden, Dirk-Bart; Dickey, Michael Walsh; Anderson, Catherine; Christianson, Kiel

2016-01-01

Functional magnetic resonance imaging (fMRI) was used to investigate neural correlates of early-closure garden-path sentence processing and use of extrasyntactic information to resolve temporary syntactic ambiguities. Sixteen participants performed an auditory picture verification task on sentences presented with natural versus flat intonation. Stimuli included sentences in which the garden-path interpretation was plausible, implausible because of a late pragmatic cue, or implausible because of a semantic mismatch between an optionally transitive verb and the following noun. Natural sentence intonation was correlated with left-hemisphere temporal activation, but also with activation that suggests the allocation of more resources to interpretation when natural prosody is provided. Garden-path processing was associated with upregulation in bilateral inferior parietal and right-hemisphere dorsolateral prefrontal and inferior frontal cortex, while differences between the strength and type of plausibility cues were also reflected in activation patterns. Region of interest (ROI) analyses in regions associated with complex syntactic processing are consistent with a role for posterior temporal cortex supporting access to verb argument structure. Furthermore, ROI analyses within left-hemisphere inferior frontal gyrus suggest a division of labour, with the anterior-ventral part primarily involved in syntactic-semantic mismatch detection, the central part supporting structural reanalysis, and the posterior-dorsal part showing a general structural complexity effect.

Supernatural Explanations: Science or Not?

Science.gov (United States)

Eastwell, Peter

2011-01-01

Contrary to the advice of supposedly authoritative sources, the a priori exclusion of supernatural explanations or claims from scientific scrutiny is not appropriate. This paper shows how supernatural hypotheses or claims should be treated by science and, in the process, differentiates scientific and non-scientific hypotheses or claims.…

First-Year Biology Students' Understandings of Meiosis: An Investigation Using a Structural Theoretical Framework

Science.gov (United States)

Quinn, Frances; Pegg, John; Panizzon, Debra

2009-01-01

Meiosis is a biological concept that is both complex and important for students to learn. This study aims to explore first-year biology students' explanations of the process of meiosis, using an explicit theoretical framework provided by the Structure of the Observed Learning Outcome (SOLO) model. The research was based on responses of 334…

Systematic reviews need to consider applicability to disadvantaged populations: inter-rater agreement for a health equity plausibility algorithm.

Science.gov (United States)

Welch, Vivian; Brand, Kevin; Kristjansson, Elizabeth; Smylie, Janet; Wells, George; Tugwell, Peter

2012-12-19

Systematic reviews have been challenged to consider effects on disadvantaged groups. A priori specification of subgroup analyses is recommended to increase the credibility of these analyses. This study aimed to develop and assess inter-rater agreement for an algorithm for systematic review authors to predict whether differences in effect measures are likely for disadvantaged populations relative to advantaged populations (only relative effect measures were addressed). A health equity plausibility algorithm was developed using clinimetric methods with three items based on literature review, key informant interviews and methodology studies. The three items dealt with the plausibility of differences in relative effects across sex or socioeconomic status (SES) due to: 1) patient characteristics; 2) intervention delivery (i.e., implementation); and 3) comparators. Thirty-five respondents (consisting of clinicians, methodologists and research users) assessed the likelihood of differences across sex and SES for ten systematic reviews with these questions. We assessed inter-rater reliability using Fleiss multi-rater kappa. The proportion agreement was 66% for patient characteristics (95% confidence interval: 61%-71%), 67% for intervention delivery (95% confidence interval: 62% to 72%) and 55% for the comparator (95% confidence interval: 50% to 60%). Inter-rater kappa, assessed with Fleiss kappa, ranged from 0 to 0.199, representing very low agreement beyond chance. Users of systematic reviews rated that important differences in relative effects across sex and socioeconomic status were plausible for a range of individual and population-level interventions. However, there was very low inter-rater agreement for these assessments. There is an unmet need for discussion of plausibility of differential effects in systematic reviews. Increased consideration of external validity and applicability to different populations and settings is warranted in systematic reviews to meet this

Self-Explanation, An Instructional Strategy to Foster Clinical Reasoning in Medical Students

Directory of Open Access Journals (Sweden)

Martine Chamberland

2015-12-01

Full Text Available Clinical reasoning is a critical and complex skill that medical students have to develop in the course of their training. Although research on medical expertise has successfully examined the different components of that skill, designing educational interventions that support the development of clinical reasoning in students remains a challenge for medical educators. The theory of medical expertise describes how students׳ medical knowledge develops and is progressively restructured during their training and in particular through clinical exposure to patient problems. Instructional strategies to foster students’ learning from practice with clinical cases are scarce. This article describes the use of self-explanation as such a strategy. Self-explanation is an active learning technique of proven effectiveness in other domains which consists of having students explaining to themselves information on to-be-learned materials. The mechanisms through which self-explanation fosters learning are described. Self-explanation promotes knowledge development and revision of mental representations through elaboration on new information, organisation and integration of new knowledge into existing cognitive structures and monitoring of the learning process. Subsequently, the article shows how self-explanation has recently been investigated in medicine as an instructional strategy to support students׳ clinical reasoning. Available studies have demonstrated that students׳ diagnostic performance improves when they use self-explanation while solving clinical problems of a less familiar clinical topic. Unfamiliarity seems to trigger more self-explanations and to stimulate students to reactivate relevant biomedical knowledge, which could lead to the development of more coherent representations of diseases. The benefit of students׳ self-explanation is increased when it is combined with listening to residents׳ self-explanation examples and with prompts. The

Making context explicit for explanation and incremental knowledge acquisition

Energy Technology Data Exchange (ETDEWEB)

Brezillon, P. [Univ. Paris (France)

1996-12-31

Intelligent systems may be improved by making context explicit in problem solving. This is a lesson drawn from a study of the reasons why a number of knowledge-based systems (KBSs) failed. We discuss the interest to make context explicit in explanation generation and incremental knowledge acquisition, two important aspects of intelligent systems that aim to cooperate with users. We show how context can be used to better explain and incrementally acquire knowledge. The advantages of using context in explanation and incremental knowledge acquisition are discussed through SEPIT, an expert system for supporting diagnosis and explanation through simulation of power plants. We point out how the limitations of such systems may be overcome by making context explicit.

Is partial behaviour a plausible explanation for the unavailability of the ICMJE disclosure form of an author in a BMJ journal?

Directory of Open Access Journals (Sweden)

Klaas van Dijk

2017-11-01

Full Text Available This case study about the ethical behaviour in the field of scholarly publishing documents an exception on the rule for research articles in the medical journal BMJ Open that ICMJE disclosure forms of authors must be made available on request. The ICMJE, the International Committee of Medical Journal Editors, has developed these forms for the disclosure of conflicts of interest for authors of medical publications. The case refers to the form of the corresponding author of an article in BMJ Open on retraction notices (Moylan and Kowalczuk, 2016. The corresponding author is a member of the council of COPE, the Committee on Publication Ethics. I will argue that the unavailability of the form relates to personal conflicts of interest with the corresponding author about my efforts to retract a fatally flawed study on the breeding biology of the Basra Reed Warbler Acrocephalus griseldis. I describe my attempts to get the form and I will argue that its unavailability can be attributed to partial behaviour by BMJ, the publisher of BMJ Open. This study complements other sources reporting ethical issues at COPE.

Some Applications of Mathematics for the Biology Classroom

Science.gov (United States)

Horton, Robert M.; Leonard, William H.

2013-01-01

Biology and mathematics are inextricably linked. In this article, we show a few of the many areas in which this linkage might be made explicit. By doing so, teachers can deepen students' understanding and appreciation of both subjects. In this article, we explore some of these areas, providing brief explanations of the mathematics and some of the…

On the nature of explanation: A PDP approach

Science.gov (United States)

Churchland, Paul M.

1990-06-01

Neural network models of sensory processing and associative memory provide the resources for a new theory of what explanatory understanding consists in. That theory finds the theoretically important factors to reside not at the level of propositions and the relations between them, but at the level of the activation patterns across large populations of neurons. The theory portrays explanatory understanding, perceptual recognition, and abductive inference as being different instances of the same more general sort of cognitive achievement, viz. prototype activation. It thus effects a unification of the theories of explanation, perception, and ampliative inference. It also finds systematic unity in the wide diversity of types of explanation (causal, functional, mathematical, intentional, reductive, etc.), a chronic problem for theories of explanation in the logico-linguistic tradition. Finally, it is free of the many defects, both logical and psychological, that plague models in that older tradition.

Why Traditional Expository Teaching-Learning Approaches May Founder? An Experimental Examination of Neural Networks in Biology Learning

Science.gov (United States)

Lee, Jun-Ki; Kwon, Yong-Ju

2011-01-01

Using functional magnetic resonance imaging (fMRI), this study investigates and discusses neurological explanations for, and the educational implications of, the neural network activations involved in hypothesis-generating and hypothesis-understanding for biology education. Two sets of task paradigms about biological phenomena were designed:…

Role of working conditions in the explanation of occupational inequalities in work injury: findings from the national French SUMER survey.

Science.gov (United States)

Niedhammer, Isabelle; Lesuffleur, Thomas; Labarthe, Géraldine; Chastang, Jean-François

2018-03-12

Social inequalities in work injury have been observed but explanations are still missing. The objectives of this study were to evaluate the contribution of working conditions in the explanation of social inequalities in work injury in a national representative sample of employees. The study was based on the cross-sectional sample of the national French survey SUMER 2010 including 46,962 employees, 26,883 men and 20,079 women. The number of work injuries within the last 12 months was studied as the outcome. Occupation was used as a marker of social position. Psychosocial work factors included various variables related to the classical job strain model, psychological demands, decision latitude, social support, and other understudied variables related to reward, job insecurity, job promotion, esteem, working time and hours and workplace violence. Occupational exposures of chemical, biological, physical and biomechanical nature were also studied. Weighted age-adjusted Poisson regression analyses were performed. Occupational gradients were observed in the exposure of most psychosocial work factors and occupational exposures. Strong occupational differences in work injury were found, blue-collar workers being more likely to have work injury. Chemical, biological, physical and biomechanical exposures contributed to explain the occupational differences in work injury substantially. Noise, thermic constraints, manual materials handling, postural/articular constraints and vibrations had significant contributions. Psychosocial work factors also contributed to explain the differences especially among women. Prevention policies oriented toward chemical, biological, physical, biomechanical and psychosocial work exposures may contribute to reduce the magnitude of occupational differences in work injury.

[Medical and biological consequences of nuclear disasters].

Science.gov (United States)

Stalpers, Lukas J A; van Dullemen, Simon; Franken, N A P Klaas

2012-01-01

Medical risks of radiation exaggerated; psychological risks underestimated. The discussion about atomic energy has become topical again following the nuclear accident in Fukushima. There is some argument about the gravity of medical and biological consequences of prolonged exposure to radiation. The risk of cancer following a low dose of radiation is usually estimated by linear extrapolation of the incidence of cancer among survivors of the atomic bombs dropped on Hiroshima and Nagasaki in 1945. The radiobiological linear-quadratic model (LQ-model) gives a more accurate description of observed data, is radiobiologically more plausible and is better supported by experimental and clinical data. On the basis of this model there is less risk of cancer being induced following radiation exposure. The gravest consequence of Chernobyl and Fukushima is not the medical and biological damage, but the psychological and economical impact on rescue workers and former inhabitants.

System as metaphor in the psychology and biology of shame.

Science.gov (United States)

Maunder, R

1996-01-01

Biological theories of brain and psychological theories of mind are two systems of explanation that seem related to one another. The nature of the relationship is problematic and constitutes the age-old mind-body problem. The most prominent solutions currently are variations of materialism. While psychological theories can be consistent with materialism, there remains a difficulty in comprehending nonphysical (social, psychological) causes of physical effects. This difficulty is an obstacle to integration in psychiatry, where we routinely assume that illnesses that include or depend on biological dysfunction are caused multifactorially by causal agents such as perceived parental warmth, parental loss, stressful life events, genetics, and personality (Hammen et al. 1992; Kendler et al. 1993). Unity theory adopts the stance that neurobiological theories and psychological theories are essentially disparate explanations of the same psychobiological events; thus the relationship of mind to brain is one of shared reference (Goodman 1991; Maunder 1995). In Goodman's model the gap between biological and psychological systems is not bridgeable. Different conceptual categories refer to the same referents but cannot interact with each other. Stepping into the breach, systems theory has been presented as offering a language that can bridge the gap between psychological and biological theories of causation (Schwartz 1981; Weiner 1989). Thus, there is a controversy about the applicability of systems theory for integration in psychiatry.

Testing the Transivity Explanation of the Allais Paradox

DEFF Research Database (Denmark)

Groes, Ebbe; Jacobsen, Hans Jørgen; Sloth, Birgitte

1999-01-01

This paper uses a two-dimensional version of a standard common consequence experiment to test the intransitivity explanation of Allais-paradox-type violations of expected utility theory. We compare the common consequence effect of two choice problems differing only with respect to whether...... intransitivity as an explanation of the Allais Paradox. The question whether violations of expected utility are mainly due to intransitivity or to violation of independence is important since it is exactly on this issue the main new decision theories differ...

On the history of biological theories of homosexuality.

Science.gov (United States)

Herrn, R

1995-01-01

Biological theories of homosexuality fit into the discourse on reproduction and sexuality that began in the nineteenth century. They arose in the context of the early homosexual rights movement, with its claim for natural rights, and the psychiatric discussions about sexual perversions. With the classification of homosexuality as a distinct category, homosexuals were excluded from the "normal". Biological theories of homosexuality were attempts not only to explain its causes, but also to maintain the exclusion of homosexuals as the "other". Biological explanations can be categorized as genetic, constitutional, endocrinological, and ethological. On the one hand, biological theories were used in the struggle for homosexual rights. On the other hand, they were used to "cure"e homosexuals. Every theory led to a specific therapy. This paper points out the roots of this thinking, traces the development of various theories, and shows the utilization of biological theories in treating homosexuality.

Criteria for deciding what is the ’best’ scientific explanation

NARCIS (Netherlands)

Wagemans, J.H.M.; Mohammed, D.; Lewiński, M.

2016-01-01

In justifying their choice of the ‘best’ scientific explanation from a number of candidate explanations, scientists may employ specific theoretical virtues and other criteria for good scientific theories. This paper is aimed at providing an inventory of such criteria and at analyzing how they

Structural Equations and Causal Explanations: Some Challenges for Causal SEM

Science.gov (United States)

Markus, Keith A.

2010-01-01

One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

Learning from instructional explanations: effects of prompts based on the active-constructive-interactive framework.

Science.gov (United States)

Roelle, Julian; Müller, Claudia; Roelle, Detlev; Berthold, Kirsten

2015-01-01

Although instructional explanations are commonly provided when learners are introduced to new content, they often fail because they are not integrated into effective learning activities. The recently introduced active-constructive-interactive framework posits an effectiveness hierarchy in which interactive learning activities are at the top; these are then followed by constructive and active learning activities, respectively. Against this background, we combined instructional explanations with different types of prompts that were designed to elicit these learning activities and tested the central predictions of the active-constructive-interactive framework. In Experiment 1, N = 83 students were randomly assigned to one of four combinations of instructional explanations and prompts. To test the active learning hypothesis, the learners received either (1) complete explanations and engaging prompts designed to elicit active activities or (2) explanations that were reduced by inferences and inference prompts designed to engage learners in constructing the withheld information. Furthermore, in order to explore how interactive learning activities can be elicited, we gave the learners who had difficulties in constructing the prompted inferences adapted remedial explanations with either (3) unspecific engaging prompts or (4) revision prompts. In support of the active learning hypothesis, we found that the learners who received reduced explanations and inference prompts outperformed the learners who received complete explanations and engaging prompts. Moreover, revision prompts were more effective in eliciting interactive learning activities than engaging prompts. In Experiment 2, N = 40 students were randomly assigned to either (1) a reduced explanations and inference prompts or (2) a reduced explanations and inference prompts plus adapted remedial explanations and revision prompts condition. In support of the constructive learning hypothesis, the learners who received

Gender differences in attitudes toward nuclear power: a multivariate explanation

International Nuclear Information System (INIS)

Baxter, R.K.

1987-01-01

The purpose of this study was to examine gender differences in attitudes toward nuclear power and to discover what factors account for these differences. The marginality explanation for these differences suggest that women have less-favorable attitudes toward nuclear power because they are less concerned about energy supplies and economic growth and are less convinced of the benefits of nuclear power for society than are men. The irrationality explanation holds that women are less favorable toward nuclear power because they are less knowledgeable about this technology than are men. The lay-rationality explanation argues that people form attitudes toward nuclear power which are consistent with their relevant beliefs, attitudes and values; thus, this explanation suggests that women's unfavorable attitudes toward nuclear power stem from greater concern about environmental protection, exposing society to risk, and lower faith in science and technology. Data for this study were collected via a mail questionnaire administered to a state wide sample of Washington residents (n= 696)

Beyond Punnett squares: Student word association and explanations of phenotypic variation through an integrative quantitative genetics unit investigating anthocyanin inheritance and expression in Brassica rapa Fast plants.

Science.gov (United States)

Batzli, Janet M; Smith, Amber R; Williams, Paul H; McGee, Seth A; Dósa, Katalin; Pfammatter, Jesse

2014-01-01

Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question "What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev)," we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students' cognitive structures before and after the unit and explanations in students' final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on "variation" as a proposed threshold concept and primary goal for students' explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from "plug and play," this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics. © 2014 J. M. Batzli et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

"Ratio via Machina": Three Standards of Mechanistic Explanation in Sociology

Science.gov (United States)

Aviles, Natalie B.; Reed, Isaac Ariail

2017-01-01

Recently, sociologists have expended much effort in attempts to define social mechanisms. We intervene in these debates by proposing that sociologists in fact have a choice to make between three standards of what constitutes a good mechanistic explanation: substantial, formal, and metaphorical mechanistic explanation. All three standards are…

Bio-physically plausible visualization of highly scattering fluorescent neocortical models for in silico experimentation

KAUST Repository

Abdellah, Marwan

2017-02-15

Background We present a visualization pipeline capable of accurate rendering of highly scattering fluorescent neocortical neuronal models. The pipeline is mainly developed to serve the computational neurobiology community. It allows the scientists to visualize the results of their virtual experiments that are performed in computer simulations, or in silico. The impact of the presented pipeline opens novel avenues for assisting the neuroscientists to build biologically accurate models of the brain. These models result from computer simulations of physical experiments that use fluorescence imaging to understand the structural and functional aspects of the brain. Due to the limited capabilities of the current visualization workflows to handle fluorescent volumetric datasets, we propose a physically-based optical model that can accurately simulate light interaction with fluorescent-tagged scattering media based on the basic principles of geometric optics and Monte Carlo path tracing. We also develop an automated and efficient framework for generating dense fluorescent tissue blocks from a neocortical column model that is composed of approximately 31000 neurons. Results Our pipeline is used to visualize a virtual fluorescent tissue block of 50 μm3 that is reconstructed from the somatosensory cortex of juvenile rat. The fluorescence optical model is qualitatively analyzed and validated against experimental emission spectra of different fluorescent dyes from the Alexa Fluor family. Conclusion We discussed a scientific visualization pipeline for creating images of synthetic neocortical neuronal models that are tagged virtually with fluorescent labels on a physically-plausible basis. The pipeline is applied to analyze and validate simulation data generated from neuroscientific in silico experiments.

Dietary antioxidant synergy in chemical and biological systems.

Science.gov (United States)

Wang, Sunan; Zhu, Fan

2017-07-24

Antioxidant (AOX) synergies have been much reported in chemical ("test-tube" based assays focusing on pure chemicals), biological (tissue culture, animal and clinical models), and food systems during the past decade. Tentative synergies differ from each other due to the composition of AOX and the quantification methods. Regeneration mechanism responsible for synergy in chemical systems has been discussed. Solvent effects could contribute to the artifacts of synergy observed in the chemical models. Synergy in chemical models may hardly be relevant to biological systems that have been much less studied. Apparent discrepancies exist in understanding the molecular mechanisms in both chemical and biological systems. This review discusses diverse variables associated with AOX synergy and molecular scenarios for explanation. Future research to better utilize the synergy is suggested.

The ethical plausibility of the 'Right To Try' laws.

Science.gov (United States)

Carrieri, D; Peccatori, F A; Boniolo, G

2018-02-01

'Right To Try' (RTT) laws originated in the USA to allow terminally ill patients to request access to early stage experimental medical products directly from the producer, removing the oversight and approval of the Food and Drug Administration. These laws have received significant media attention and almost equally unanimous criticism by the bioethics, clinical and scientific communities. They touch indeed on complex issues such as the conflict between individual and public interest, and the public understanding of medical research and its regulation. The increased awareness around RTT laws means that healthcare providers directly involved in the management of patients with life-threatening conditions such as cancer, infective, or neurologic conditions will deal more frequently with patients' requests of access to experimental medical products. This paper aims to assess the ethical plausibility of the RTT laws, and to suggest some possible ethical tools and considerations to address the main issues they touch. Copyright © 2017 Elsevier B.V. All rights reserved.

Plausible inference: A multi-valued logic for problem solving

Science.gov (United States)

Friedman, L.

1979-01-01

A new logic is developed which permits continuously variable strength of belief in the truth of assertions. Four inference rules result, with formal logic as a limiting case. Quantification of belief is defined. Propagation of belief to linked assertions results from dependency-based techniques of truth maintenance so that local consistency is achieved or contradiction discovered in problem solving. Rules for combining, confirming, or disconfirming beliefs are given, and several heuristics are suggested that apply to revising already formed beliefs in the light of new evidence. The strength of belief that results in such revisions based on conflicting evidence are a highly subjective phenomenon. Certain quantification rules appear to reflect an orderliness in the subjectivity. Several examples of reasoning by plausible inference are given, including a legal example and one from robot learning. Propagation of belief takes place in directions forbidden in formal logic and this results in conclusions becoming possible for a given set of assertions that are not reachable by formal logic.

Competence Matching Tool - Explanations and Implementation

NARCIS (Netherlands)

Herder, Eelco; Kärger, Philipp

2010-01-01

Herder, E., Kärger, P. (2009) Competence Matching Tool - Explanations and Implementation. The document contains the technical specification of the competence matching tool. The tool can be found at http://tencompetence.cvs.sourceforge.net/viewvc/tencompetence/wp7/CompetenceMatcher/ and the location

Looking for a Location: Dissociated Effects of Event-Related Plausibility and Verb-Argument Information on Predictive Processing in Aphasia.

Science.gov (United States)

Hayes, Rebecca A; Dickey, Michael Walsh; Warren, Tessa

2016-12-01

This study examined the influence of verb-argument information and event-related plausibility on prediction of upcoming event locations in people with aphasia, as well as older and younger, neurotypical adults. It investigated how these types of information interact during anticipatory processing and how the ability to take advantage of the different types of information is affected by aphasia. This study used a modified visual-world task to examine eye movements and offline photo selection. Twelve adults with aphasia (aged 54-82 years) as well as 44 young adults (aged 18-31 years) and 18 older adults (aged 50-71 years) participated. Neurotypical adults used verb argument status and plausibility information to guide both eye gaze (a measure of anticipatory processing) and image selection (a measure of ultimate interpretation). Argument status did not affect the behavior of people with aphasia in either measure. There was only limited evidence of interaction between these 2 factors in eye gaze data. Both event-related plausibility and verb-based argument status contributed to anticipatory processing of upcoming event locations among younger and older neurotypical adults. However, event-related likelihood had a much larger role in the performance of people with aphasia than did verb-based knowledge regarding argument structure.

Looking for a Location: Dissociated Effects of Event-Related Plausibility and Verb–Argument Information on Predictive Processing in Aphasia

Science.gov (United States)

Dickey, Michael Walsh; Warren, Tessa

2016-01-01

Purpose This study examined the influence of verb–argument information and event-related plausibility on prediction of upcoming event locations in people with aphasia, as well as older and younger, neurotypical adults. It investigated how these types of information interact during anticipatory processing and how the ability to take advantage of the different types of information is affected by aphasia. Method This study used a modified visual-world task to examine eye movements and offline photo selection. Twelve adults with aphasia (aged 54–82 years) as well as 44 young adults (aged 18–31 years) and 18 older adults (aged 50–71 years) participated. Results Neurotypical adults used verb argument status and plausibility information to guide both eye gaze (a measure of anticipatory processing) and image selection (a measure of ultimate interpretation). Argument status did not affect the behavior of people with aphasia in either measure. There was only limited evidence of interaction between these 2 factors in eye gaze data. Conclusions Both event-related plausibility and verb-based argument status contributed to anticipatory processing of upcoming event locations among younger and older neurotypical adults. However, event-related likelihood had a much larger role in the performance of people with aphasia than did verb-based knowledge regarding argument structure. PMID:27997951

Separable explanations of neural network decisions

DEFF Research Database (Denmark)

Rieger, Laura

2017-01-01

Deep Taylor Decomposition is a method used to explain neural network decisions. When applying this method to non-dominant classifications, the resulting explanation does not reflect important features for the chosen classification. We propose that this is caused by the dense layers and propose...

Liderazgo preventivo para la universidad. Una experiencia plausible

Directory of Open Access Journals (Sweden)

Alejandro Rodríguez Rodríguez

2015-06-01

Full Text Available El desarrollo del liderazgo, en el ámbito educativo superior, busca soluciones de aplicación inmediata a contextos en que todo líder se desenvuelve, pero se diluye el sustento teórico-práctico en la formación del líder que posibilite entender los procesos intelectivos durante la toma de decisiones. El paradigma de convergencia entre el método antropológico lonerganiano, la comunidad de aprendizaje vygotskiana y una relectura del sistema preventivo salesiano se presentan como propuesta plausible de formación al liderazgo preventivo entre los diversos actores de una comunidad universitaria. Un estudio de caso de la Universidad Salesiana en México empleando un método mixto de investigación, facilita una relectura del liderazgo desde una óptica preventiva como posibilidad de convergencia en un diálogo interdisciplinar. Los resultados teórico-práctico propuestos y examinados se muestran como herramienta útil para evaluar, enriquecer y renovar la teoría sobre el líder y el desarrollo de liderazgo en las universidades frente a una sociedad globalizada.

Exploring Dominant Types of Explanations Built by General Chemistry Students

Science.gov (United States)

Talanquer, Vicente

2010-01-01

The central goal of our study was to explore the nature of the explanations generated by science and engineering majors with basic training in chemistry to account for the colligative properties of solutions. The work was motivated by our broader interest in the characterisation of the dominant types of explanations that science college students…

Auditory Verbal Hallucinations in Schizophrenia From a Levels of Explanation Perspective.

Science.gov (United States)

Hugdahl, Kenneth; Sommer, Iris E

2018-02-15

In the present article, we present a "Levels of Explanation" (LoE) approach to auditory verbal hallucinations (AVHs) in schizophrenia. Mental phenomena can be understood at different levels of explanation, including cultural, clinical, cognitive, brain imaging, cellular, and molecular levels. Current research on AVHs is characterized by accumulation of data at all levels, but with little or no interaction of findings between levels. A second advantage with a Levels of Explanation approach is that it fosters interdisciplinarity and collaboration across traditional borders, facilitating a real breakthrough in future research. We exemplify a Levels of Explanation approach with data from 3 levels where findings at 1 level provide predictions for another level. More specifically, we show how functional neuroimaging data at the brain level correspond with behavioral data at the cognitive level, and how data at these 2 levels correspond with recent findings of changes in neurotransmitter function at the cellular level. We further discuss implications for new therapeutic interventions, and the article is ended by suggestion how future research could incorporate genetic influences on AVHs at the molecular level of explanation by providing examples for animal work.

How perceptions of experience-based analysis influence explanations of work accidents.

Science.gov (United States)

Mbaye, Safiétou; Kouabenan, Dongo Rémi

2013-12-01

This article looks into how perceptions of experience-based analysis (EBA) influence causal explanations of accidents given by managers and workers in the chemical industry (n=409) and in the nuclear industry (n=222). The approach is based on the model of naive explanations of accidents (Kouabenan, 1999, 2006, 2009), which recommends taking into account explanations of accidents spontaneously given by individuals, including laypersons, not only to better understand why accidents occur but also to design and implement the most appropriate prevention measures. The study reported here describes the impact of perceptions about EBA (perceived effectiveness, personal commitment, and the feeling of being involved in EBA practices) on managers' and workers' explanations of accidents likely to occur at the workplace. The results indicated that both managers and workers made more internal explanations than external ones when they perceived EBA positively. Moreover, the more the participants felt involved in EBA, were committed to it, and judged it effective, the more they explained accidents in terms of factors internal to the workers. Recommendations are proposed for reducing defensive reactions, increasing personal commitment to EBA, and improving EBA effectiveness. © 2013.

Strategic Explanations for a Diagnostic Consultation System. Technical Report #8.

Science.gov (United States)

Hasling, Diane Warner; And Others

This paper examines the problem of automatic explanation of reasoning, or the ability of a program to discuss what it is doing in some understandable way, particularly as part of an expert system. An introduction presents a general framework in which to view explanation and reviews some of the research in this area. This is followed by a…

Mathematics, structuralism and biology.

Science.gov (United States)

Saunders, P T

1988-01-01

A new approach is gaining ground in biology, one that has much in common with the structuralist tradition in other fields. It is very much in the spirit of an earlier view of biology and indeed of science in general. It is also, though this is not generally recognized, in the spirit of twentieth century physics. As in modern physics, however, it is not a question of ignoring all the progress that has been made within the former paradigm. On the contrary, the aim is to use it as a basis for setting out in a somewhat different direction. Complex phenomena do not generally lend themselves to reductionist analyses which seek explanation only in terms of detailed mechanisms, but a proper scientific discussion of structure must make full use of what we have already learned - by whatever means - about the processes that underly the phenomena we are trying to understand.

Biphasic dose responses in biology, toxicology and medicine: Accounting for their generalizability and quantitative features

International Nuclear Information System (INIS)

Calabrese, Edward J.

2013-01-01

The most common quantitative feature of the hormetic-biphasic dose response is its modest stimulatory response which at maximum is only 30–60% greater than control values, an observation that is consistently independent of biological model, level of organization (i.e., cell, organ or individual), endpoint measured, chemical/physical agent studied, or mechanism. This quantitative feature suggests an underlying “upstream” mechanism common across biological systems, therefore basic and general. Hormetic dose response relationships represent an estimate of the peak performance of integrative biological processes that are allometrically based. Hormetic responses reflect both direct stimulatory or overcompensation responses to damage induced by relatively low doses of chemical or physical agents. The integration of the hormetic dose response within an allometric framework provides, for the first time, an explanation for both the generality and the quantitative features of the hormetic dose response. -- Highlights: •The hormetic stimulation is at maximum 30–60% greater than control responses. •Hormesis is a measure of biological performance and plasticity. •The hormetic response is evolutionary based and highly generalizable. -- This paper provides a biologically based explanation for the generalizability/quantitative features of the hormetic dose response, representing a fundamental contribution to the field

Enhancing human understanding through intelligent explanations

NARCIS (Netherlands)

Mioch, T.; Harbers, M.; Doesburg, W.A. van; Bosch, K. van den

2007-01-01

Ambient systems that explain their actions promote the user's understanding as they give the user more insight in the e®ects of their behavior on the environment. In order to provide individualized intelligent explanations, we need not only to evaluate a user's observable behavior, but we also need

Society by Numbers : Studies on Model-Based Explanations in the Social Sciences

OpenAIRE

Kuorikoski, Jaakko

2010-01-01

The aim of this dissertation is to provide conceptual tools for the social scientist for clarifying, evaluating and comparing explanations of social phenomena based on formal mathematical models. The focus is on relatively simple theoretical models and simulations, not statistical models. These studies apply a theory of explanation according to which explanation is about tracing objective relations of dependence, knowledge of which enables answers to contrastive why and how-questions. This th...

Bequest Motives and the Annuity Puzzle.

Science.gov (United States)

Lockwood, Lee M

2012-04-01

Few retirees annuitize any wealth, a fact that has so far defied explanation within the standard framework of forward-looking, expected utility-maximizing agents. Bequest motives seem a natural explanation. Yet the prevailing view is that people with plausible bequest motives should annuitize part of their wealth, and thus that bequest motives cannot explain why most people do not annuitize any wealth. I show, however, that people with plausible bequest motives are likely to be better off not annuitizing any wealth at available rates. The evidence suggests that bequest motives play a central role in limiting the demand for annuities.

Not just a theory--the utility of mathematical models in evolutionary biology.

Directory of Open Access Journals (Sweden)

Maria R Servedio

2014-12-01

Full Text Available Progress in science often begins with verbal hypotheses meant to explain why certain biological phenomena exist. An important purpose of mathematical models in evolutionary research, as in many other fields, is to act as “proof-of-concept” tests of the logic in verbal explanations, paralleling the way in which empirical data are used to test hypotheses. Because not all subfields of biology use mathematics for this purpose, misunderstandings of the function of proof-of-concept modeling are common. In the hope of facilitating communication, we discuss the role of proof-of-concept modeling in evolutionary biology.

Preview Effects of Plausibility and Character Order in Reading Chinese Transposed Words: Evidence from Eye Movements

Science.gov (United States)

Yang, Jinmian

2013-01-01

The current paper examined the role of plausibility information in the parafovea for Chinese readers by using two-character transposed words (in which the order of the component characters is reversed but are still words). In two eye-tracking experiments, readers received a preview of a target word that was (1) identical to the target word, (2) a…

Refining Students' Explanations of an Unfamiliar Physical Phenomenon-Microscopic Friction

Science.gov (United States)

Corpuz, Edgar De Guzman; Rebello, N. Sanjay

2017-08-01

The first phase of this multiphase study involves modeling of college students' thinking of friction at the microscopic level. Diagnostic interviews were conducted with 11 students with different levels of physics backgrounds. A phenomenographic approach of data analysis was used to generate categories of responses which subsequently were used to generate a model of explanation. Most of the students interviewed consistently used mechanical interactions in explaining microscopic friction. According to these students, friction is due to the interlocking or rubbing of atoms. Our data suggest that students' explanations of microscopic friction are predominantly influenced by their macroscopic experiences. In the second phase of the research, teaching experiment was conducted with 18 college students to investigate how students' explanations of microscopic friction can be refined by a series of model-building activities. Data were analyzed using Redish's two-level transfer framework. Our results show that through sequences of hands-on and minds-on activities, including cognitive dissonance and resolution, it is possible to facilitate the refinement of students' explanations of microscopic friction. The activities seemed to be productive in helping students activate associations that refine their ideas about microscopic friction.

Selective effects of explanation on learning during early childhood.

Science.gov (United States)

Legare, Cristine H; Lombrozo, Tania

2014-10-01

Two studies examined the specificity of effects of explanation on learning by prompting 3- to 6-year-old children to explain a mechanical toy and comparing what they learned about the toy's causal and non-causal properties with children who only observed the toy, both with and without accompanying verbalization. In Study 1, children were experimentally assigned to either explain or observe the mechanical toy. In Study 2, children were classified according to whether the content of their response to an undirected prompt involved explanation. Dependent measures included whether children understood the toy's functional-mechanical relationships, remembered perceptual features of the toy, effectively reconstructed the toy, and (for Study 2) generalized the function of the toy when constructing a new one. Results demonstrate that across age groups, explanation promotes causal learning and generalization but does not improve (and in younger children can even impair) memory for causally irrelevant perceptual details. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

The Coexistence of Natural and Supernatural Explanations across Cultures and Development

Science.gov (United States)

Legare, Cristine H.; Evans, E. Margaret; Rosengren, Karl S.; Harris, Paul L.

2012-01-01

Although often conceptualized in contradictory terms, the common assumption that natural and supernatural explanations are incompatible is psychologically inaccurate. Instead, there is considerable evidence that the same individuals use both natural and supernatural explanations to interpret the very same events and that there are multiple ways in…

Synthetic Biology and the Moral Significance of Artificial Life: A Reply to Douglas, Powell and Savulescu.

Science.gov (United States)

Christiansen, Andreas

2016-06-01

I discuss the moral significance of artificial life within synthetic biology via a discussion of Douglas, Powell and Savulescu's paper 'Is the creation of artificial life morally significant'. I argue that the definitions of 'artificial life' and of 'moral significance' are too narrow. Douglas, Powell and Savulescu's definition of artificial life does not capture all core projects of synthetic biology or the ethical concerns that have been voiced, and their definition of moral significance fails to take into account the possibility that creating artificial life is conditionally acceptable. Finally, I show how several important objections to synthetic biology are plausibly understood as arguing that creating artificial life in a wide sense is only conditionally acceptable. © 2016 John Wiley & Sons Ltd.

Biologi Komunikasi melalui Implementasi “Information Communications Technology”

OpenAIRE

Darmawan, Deni

2010-01-01

The Biological communication Behavior has been constructed through the explanation of  the phenomena of their specific part of activies encompassing: Prefrontal, Frontal, Parietal, Central, Occipital and Parasagital which have been significantly tested in terms of their impacts in learning acceleration starting from Elementary School to College level. This study is conducted by means of constructive approach, meaning that it employs both the Quantitative and Qualitative techniques.The study o...

Memory accessibility shapes explanation: Testing key claims of the inherence heuristic account.

Science.gov (United States)

Hussak, Larisa J; Cimpian, Andrei

2018-01-01

People understand the world by constructing explanations for what they observe. It is thus important to identify the cognitive processes underlying these judgments. According to a recent proposal, everyday explanations are often constructed heuristically: Because people need to generate explanations on a moment-by-moment basis, they cannot perform an exhaustive search through the space of possible reasons, but may instead use the information that is most easily accessible in memory (Cimpian & Salomon 2014a, b). In the present research, we tested two key claims of this proposal that have so far not been investigated. First, we tested whether-as previously hypothesized-the information about an entity that is most accessible in memory tends to consist of inherent or intrinsic facts about that entity, rather than extrinsic (contextual, historical, etc.) facts about it (Studies 1 and 2). Second, we tested the implications of this difference in the memory accessibility of inherent versus extrinsic facts for the process of generating explanations: Does the fact that inherent facts are more accessible than relevant extrinsic facts give rise to an inherence bias in the content of the explanations generated (Studies 3 and 4)? The findings supported the proposal that everyday explanations are generated in part via a heuristic process that relies on easily accessible-and often inherent-information from memory.

A Teaching Model for Scaffolding 4th Grade Students' Scientific Explanation Writing

Science.gov (United States)

Yang, Hsiu-Ting; Wang, Kuo-Hua

2014-08-01

Improving students scientific explanations is one major goal of science education. Both writing activities and concept mapping are reported as effective strategies for enhancing student learning of science. The purpose of this study was to examine the effect of a teaching model, named the DCI model, which integrates a Descriptive explanation writing activity, Concept mapping, and an Interpretive explanation writing activity, is introduced in a 4th grade science class to see if it would improve students' scientific explanations and understanding. A quasi-experimental design, including a non-randomized comparison group and a pre- and post-test design, was adopted for this study. An experimental group of 25 students were taught using the DCI teaching model, while a comparison group received a traditional lecture teaching. A rubric and content analysis was used to assess students' scientific explanations. The independent sample t test was used to measure difference in conceptual understanding between the two groups, before and after instruction. Then, the paired t test analysis was used to understand the promotion of the DCI teaching model. The results showed that students in the experimental group performed better than students in the comparison group, both in scientific concept understanding and explanation. Suggestions for using concept mapping and writing activities (the DCI teaching model) in science classes are provided in this study.

Biology, ideology, and epistemology: how do we know political attitudes are inherited and why should we care?

Science.gov (United States)

Smith, Kevin; Alford, John R; Hatemi, Peter K; Eaves, Lindon J; Funk, Carolyn; Hibbing, John R

2012-01-01

Evidence that political attitudes and behavior are in part biologically and even genetically instantiated is much discussed in political science of late. Yet the classic twin design, a primary source of evidence on this matter, has been criticized for being biased toward finding genetic influence. In this article, we employ a new data source to test empirically the alternative, exclusively environmental, explanations for ideological similarities between twins. We find little support for these explanations and argue that even if we treat them as wholly correct, they provide reasons for political science to pay more rather than less attention to the biological basis of attitudes and behaviors. Our analysis suggests that the mainstream socialization paradigm for explaining attitudes and behaviors is not necessarily incorrect but is substantively incomplete.

The role of biological fertility in predicting family size

DEFF Research Database (Denmark)

Joffe, M; Key, J; Best, N

2009-01-01

for the first child. CONCLUSIONS: Within the limits of the available data quality, family size appears to be predicted by biological fertility, even after adjustment for maternal age, if the woman was at least 20 years old when the couple's first attempt at conception started. The contribution of behavioural......BACKGROUND: It is plausible that a couple's ability to achieve the desired number of children is limited by biological fertility, especially if childbearing is postponed. Family size has declined and semen quality may have deteriorated in much of Europe, although studies have found an increase....... Potential confounders were maternal age when unprotected sex began prior to the first birth, and maternal smoking. Desired family size was available in only one of the datasets. RESULTS: Couples with a TTP of at least 12 months tended to have smaller families, with odds ratios for the risk of not having...

Quantum physics meets biology.

Science.gov (United States)

Arndt, Markus; Juffmann, Thomas; Vedral, Vlatko

2009-12-01

Quantum physics and biology have long been regarded as unrelated disciplines, describing nature at the inanimate microlevel on the one hand and living species on the other hand. Over the past decades the life sciences have succeeded in providing ever more and refined explanations of macroscopic phenomena that were based on an improved understanding of molecular structures and mechanisms. Simultaneously, quantum physics, originally rooted in a world-view of quantum coherences, entanglement, and other nonclassical effects, has been heading toward systems of increasing complexity. The present perspective article shall serve as a "pedestrian guide" to the growing interconnections between the two fields. We recapitulate the generic and sometimes unintuitive characteristics of quantum physics and point to a number of applications in the life sciences. We discuss our criteria for a future "quantum biology," its current status, recent experimental progress, and also the restrictions that nature imposes on bold extrapolations of quantum theory to macroscopic phenomena.

The Many Roles of "Explanation" in Science Education: A Case Study

Science.gov (United States)

Rocksén, Miranda

2016-01-01

In this paper the role of explanations is discussed in relation to possible consequences originating in the polysemy of the word explanation. The present study is a response to conceptual confusions that have arisen in the intersection between theory and practice, and between science education literature and communication in authentic science…

Synthesizing Proximate and Distal Levels of Explanation: Toward an Evolution-Informed Sociology

Directory of Open Access Journals (Sweden)

Lawrence H. Williams

2018-06-01

Full Text Available In this paper, we argue that despite the growing acceptance of psychological research by mainstream sociologists, the discipline of sociology remains largely averse to biology. This is because the kind of psychological research that sociologists now utilize tends to rely on the same assumptions of thought, action, and human behavior—broadly construed—that sociologists have on the whole tacitly endorsed since Durkheim's seminal criticism of Kantian categories in The Elementary Forms of Religious Life: Namely, that fundamental categories of perception, though naturally experienced, are socially constructed. This assumption is present in both psychological work on schemas and the dual-process model, which continue to be incorporated into sociological analysis at a growing pace. We further demonstrate how sociologists' overall positive reception of this kind of psychological research was facilitated by two factors: the rejection of biological explanations of human behavior and the tacit commitment to social causes by many sociologists in the field throughout the twentieth century. We demonstrate how synthesizing biological research with sociological research can extend existing sociological work by focusing on the study of parenting and crime and deviance. In these subfields, we believe sociologists can gain better understanding of their topics by moving from relatively proximate concerns to more distal ones. We conclude by asserting that seeing individuals' decision-making styles and capacities as a product of both evolved and social processes can lead to the development of more robust and yet parsimonious models of action in the discipline. Doing so need not make sociologists blindly endorse evolutionary approaches to human behavior, but start our theories with a view to both long and short history.

Inside case-based explanation

CERN Document Server

Schank, Roger C; Riesbeck, Christopher K

2014-01-01

This book is the third volume in a series that provides a hands-on perspective on the evolving theories associated with Roger Schank and his students. The primary focus of this volume is on constructing explanations. All of the chapters relate to the problem of building computer programs that can develop hypotheses about what might have caused an observed event. Because most researchers in natural language processing don't really want to work on inference, memory, and learning issues, most of their sample text fragments are chosen carefully to de-emphasize the need for non text-related reasoni

Uncertain socioeconomic projections used in travel demand and emissions models: could plausible errors result in air quality nonconformity?

International Nuclear Information System (INIS)

Rodier, C.J.; Johnston, R.A.

2002-01-01

A sensitivity analysis of plausible errors in population, employment, fuel price, and income projections is conducted using the travel demand and emissions models of the Sacramento, CA, USA, region for their transportation plan. The results of the analyses indicate that plausible error ranges for household income and fuel prices are not a significant source of uncertainty with respect to the region's travel demand and emissions projections. However, plausible errors in population and employment projections (within approximately one standard deviation) may result in the region's transportation plan not meeting the conformity test for nitrogens of oxides (NO x ) in the year 2005 (i.e., an approximately 16% probability). This outcome is also possible in the year 2015 but less likely (within approximately two standard deviations or a 2.5% probability). Errors in socioeconomic projections are only one of many sources of error in travel demand and emissions models. These results have several policy implications. First, regions like Sacramento that meet their conformity tests by a very small margin should rethink new highway investment and consider contingency transportation plans that incorporate more aggressive emissions reduction policies. Second, regional transportation planning agencies should conduct sensitivity analyses as part of their conformity analysis to make explicit significant uncertainties in the methods and to identify the probability of their transportation plan not conforming. Third, the US Environmental Protection Agency (EPA) should clarify the interpretation of ''demonstrate'' conformity of transportation plans; that is, specify the level of certainty that it considers a sufficient demonstration of conformity. (author)

A Biologically Plausible Action Selection System for Cognitive Architectures: Implications of Basal Ganglia Anatomy for Learning and Decision-Making Models

Science.gov (United States)

Stocco, Andrea

2018-01-01

Several attempts have been made previously to provide a biological grounding for cognitive architectures by relating their components to the computations of specific brain circuits. Often, the architecture's action selection system is identified with the basal ganglia. However, this identification overlooks one of the most important features of…

Towards to An Explanation for Conceptual Change: A Mechanistic Alternative

Science.gov (United States)

Rusanen, Anna-Mari

2014-07-01

Conceptual change is one of the most studied fields in science education and psychology of learning. However, there are still some foundational issues in conceptual change research on which no clear consensus has emerged. Firstly, there is no agreement on what changes in belief and concept systems constitute conceptual change and what changes do not. Secondly, there is no consensus on what the specific mechanisms of conceptual change are. Thirdly, there is no common explanatory framework of how to explain conceptual change. In this paper a sketch for explanations of conceptual change is outlined. According to this account, the explanation for conceptual change requires (1) a description for the information processing task and (2) a sufficiently accurate and detailed description of the cognitive mechanisms responsible for the task. The scope and limits of this type of explanation are discussed.

How delusion is formed?

Science.gov (United States)

Park, Jong Suk; Kang, Ung Gu

2016-02-01

Traditionally, delusions have been considered to be the products of misinterpretation and irrationality. However, some theorists have argued that delusions are normal or rational cognitive responses to abnormal experiences. That is, when a recently experienced peculiar event is more plausibly explained by an extraordinary hypothesis, confidence in the veracity of this extraordinary explanation is reinforced. As the number of such experiences, driven by the primary disease process in the perceptual domain, increases, this confidence builds and solidifies, forming a delusion. We tried to understand the formation of delusions using a simulation based on Bayesian inference. We found that (1) even if a delusional explanation is only marginally more plausible than a non-delusional one, the repetition of the same experience results in a firm belief in the delusion. (2) The same process explains the systematization of delusions. (3) If the perceived plausibility of the explanation is not consistent but varies over time, the development of a delusion is delayed. Additionally, this model may explain why delusions are not corrected by persuasion or rational explanation. This Bayesian inference perspective can be considered a way to understand delusions in terms of rational human heuristics. However, such experiences of "rationality" can lead to irrational conclusions, depending on the characteristics of the subject. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Evolution of Contractual Morality

Directory of Open Access Journals (Sweden)

Alejandro Rosas

2011-12-01

Full Text Available Evolutionary explanations of altruism and human cooperation, first set forth by pioneers such as Darwin, Hamilton and Trivers, suggest that biology might be capable of offering a plausible scientific explanation of the core of human morality. According to this project, morality and human cooperation arise when resourcesare scarce; they cannot be exploited by isolated individuals; and individuals cannot maintain a long-term position of domination over others in order to advance their selfish ends. An important philosophical question that arises with respect to this project has to do with the concepts of de morality and moral motivation that itpresupposes. The evolutionary project has not been clear in this respect. The article argues in favor of two theses: 1 evolutionary explanations of cooperation suggest a contractual type of morality, but they are ambiguous regarding the motivations favored by natural selection, thus reflecting, without resolving it, a traditionaldisagreement between Hobbes’s moral contractualism (selfish motivations and that of Kant (altruistic motivations; 2 in their current form, these explanations cannot resolve that disagreement, but a reflection on the role of the capacity to interpret the motivations and character of others in the evolution of morality could provide arguments in favor of Kantian contractualism.

Using Self-Explanations in the Laboratory to Connect Theory and Practice: The Decision/ Explanation/Observation/Inference Writing Method

Science.gov (United States)

Van Duzor, Andrea Gay

2016-01-01

While many faculty seek to use student-centered, inquiry-based approaches in teaching laboratories, transitioning from traditional to inquiry instruction can be logistically challenging. This paper outlines use of a laboratory notebook and report writing-to-learn method that emphasizes student self-explanations of procedures and outcomes,…

Analytic models of plausible gravitational lens potentials

International Nuclear Information System (INIS)

Baltz, Edward A.; Marshall, Phil; Oguri, Masamune

2009-01-01

Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sérsic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasising that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential. We also provide analytic formulae for the lens potentials of Sérsic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modelled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses

Biological formal counterparts of logical machines

Energy Technology Data Exchange (ETDEWEB)

Moreno-diaz, R; Hernandez Guarch, F

1983-01-01

The significance of the McCulloch-Pitts formal neural net theory (1943) is still nowadays frequently misunderstood, and their basic units are wrongly considered as factual models for neurons. As a consequence, the whole original theory and its later addenda are unreasonably criticized for their simplicity. But, as it was proved then and since, the theory is after the modular neurophysiological counterpart of logical machines, so that it actually provides biologically plausible models for automata, turing machines, etc., and not vice versa. In its true context, no theory has surpassed its proposals. In McCulloch and Pitts memoriam and for the sake of future theoretical research, the authors stress this important historical point, including also some recent results on the neurophysiological counterparts of modular arbitrary probabilistic automata. 16 references.

Dynamical explanation for the high water abundance detected in Orion

International Nuclear Information System (INIS)

Elitzur, M.

1979-01-01

Shock wave chemistry is suggested as the likely explanation for the high water abundance which has been recently detected in Orion by Phyllips et al. The existence of such a shock and its inferred properties are in agreement with other observations of Orion such as the broad velocity feature and H 2 vibration emission. Shock waves are proposed as the likely explanation for high water abundances observed in other sources such as the strong H 2 O masers

Theism and Inference to the Best Explanation

NARCIS (Netherlands)

Holten, W. van

2002-01-01

In this paper the author critically examines the explanatory role of theistic belief. Although talk of religious beliefs as explanations is commonly employed in the context of religious epistemology, it may also serve to simply characterise one of the functions of religious views of life. It is

Theism and inference to the Best Explanation

NARCIS (Netherlands)

Holten, Wilko van

2002-01-01

In this paper the author critically examines the explanatory role of theistic belief. Although talk of religious beliefs as explanations is commonly employed in the context of religious epistemology, it may also serve to simply characterise one of the functions of religious views of life. It is

Cultural border crossing: The interaction between fundamental Christian beliefs and scientific explanations

Science.gov (United States)

Elimbi, Celestine Nakeli

The purpose of this study is to investigate the interaction between people's fundamental Christian beliefs and scientific explanations. When people with fundamental Christian beliefs encounter scientific explanations, such explanations may interact with their deeply rooted beliefs in a way that is likely to produce tensions. It is expedient to understand the classroom/professional experiences of such individuals and how they manage these tensions. I will apply Jegede's collateral learning theory as a lens to look at how individuals manage the tensions between their religious and scientific worldviews. Gaining insight into people's experiences in the classroom/work place and how they manage these tensions will potentially inform classroom instruction and ways by which we can help students with fundamental Christian beliefs maintain their pursuit of science related careers by easing the nature of the borders they cross. Sources of data will include participant reported perspectives of how they manage the tensions and observations of real-time resolution of potentially conflicting explanations from their religious and scientific worldviews.

Chemical, Biological, and Radiological (CBR) Contamination Survivability: Large Item Interiors

Science.gov (United States)

2012-06-22

CWAs. May cause hardening or swelling of the sealant, which may weaken the seal. Rivet Stainless steel Not expected to have any effect. Not... Electromagnetic Pulse (EMP). TOP 08-2-509 22 June 2012 A-2 APPENDIX A. EXPLANATION OF TERMS. Combat Developer. A category of sponsor...Edgewood Chemical Biological Center EMP electromagnetic pulse FD/SC Failure Definition/Scoring Criteria FM Field Manual FP fluorescent particle

Exploring the MACH Model's Potential as a Metacognitive Tool to Help Undergraduate Students Monitor Their Explanations of Biological Mechanisms

Science.gov (United States)

Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

2016-01-01

When undergraduate biology students learn to explain biological mechanisms, they face many challenges and may overestimate their understanding of living systems. Previously, we developed the MACH model of four components used by expert biologists to explain mechanisms: Methods, Analogies, Context, and How. This study explores the implementation of…

Students' self-explanations while solving unfamiliar cases: the role of biomedical knowledge.

Science.gov (United States)

Chamberland, Martine; Mamede, Sílvia; St-Onge, Christina; Rivard, Marc-Antoine; Setrakian, Jean; Lévesque, Annie; Lanthier, Luc; Schmidt, Henk G; Rikers, Remy M J P

2013-11-01

General guidelines for teaching clinical reasoning have received much attention, despite a paucity of instructional approaches with demonstrated effectiveness. As suggested in a recent experimental study, self-explanation while solving clinical cases may be an effective strategy to foster reasoning in clinical clerks dealing with less familiar cases. However, the mechanisms that mediate this benefit have not been specifically investigated. The aim of this study was to explore the types of knowledge used by students when solving familiar and less familiar clinical cases with self-explanation. In a previous study, 36 third-year medical students diagnosed familiar and less familiar clinical cases either by engaging in self-explanation or not. Based on an analysis of previously collected data, the present study compared the content of self-explanation protocols generated by seven randomly selected students while solving four familiar and four less familiar cases. In total, 56 verbal protocols (28 familiar and 28 less familiar) were segmented and coded using the following categories: paraphrases, biomedical inferences, clinical inferences, monitoring statements and errors. Students provided more self-explanation segments from less familiar cases (M = 275.29) than from familiar cases (M = 248.71, p = 0.046). They provided significantly more paraphrases (p = 0.001) and made more errors (p = 0.008). A significant interaction was found between familiarity and the type of inferences (biomedical versus clinical, p = 0.016). When self-explaining less familiar cases, students provided significantly more biomedical inferences than familiar cases. Lack of familiarity with a case seems to stimulate medical students to engage in more extensive thinking during self-explanation. Less familiar cases seem to activate students' biomedical knowledge, which in turn helps them to create new links between biomedical and clinical knowledge, and eventually construct a more coherent mental

Students' explanations in complex learning of disciplinary programming

Science.gov (United States)

Vieira, Camilo

Computational Science and Engineering (CSE) has been denominated as the third pillar of science and as a set of important skills to solve the problems of a global society. Along with the theoretical and the experimental approaches, computation offers a third alternative to solve complex problems that require processing large amounts of data, or representing complex phenomena that are not easy to experiment with. Despite the relevance of CSE, current professionals and scientists are not well prepared to take advantage of this set of tools and methods. Computation is usually taught in an isolated way from engineering disciplines, and therefore, engineers do not know how to exploit CSE affordances. This dissertation intends to introduce computational tools and methods contextualized within the Materials Science and Engineering curriculum. Considering that learning how to program is a complex task, the dissertation explores effective pedagogical practices that can support student disciplinary and computational learning. Two case studies will be evaluated to identify the characteristics of effective worked examples in the context of CSE. Specifically, this dissertation explores students explanations of these worked examples in two engineering courses with different levels of transparency: a programming course in materials science and engineering glass box and a thermodynamics course involving computational representations black box. Results from this study suggest that students benefit in different ways from writing in-code comments. These benefits include but are not limited to: connecting xv individual lines of code to the overall problem, getting familiar with the syntax, learning effective algorithm design strategies, and connecting computation with their discipline. Students in the glass box context generate higher quality explanations than students in the black box context. These explanations are related to students prior experiences. Specifically, students with

Ontological Order in Scientific Explanation | Park | Philosophical ...

African Journals Online (AJOL)

A conceptually sound explanation, I claim, respects the ontological order between properties. A dependent property is to be explained in terms of its underlying property, not the other way around. The applicability of this point goes well beyond the realm of the debate between scientific realists and antirealists.

Analysis of undergraduate cell biology contents in Brazilian public universities.

Science.gov (United States)

Mermelstein, Claudia; Costa, Manoel Luis

2017-04-01

The enormous amount of information available in cell biology has created a challenge in selecting the core concepts we should be teaching our undergraduates. One way to define a set of essential core ideas in cell biology is to analyze what a specific cell biology community is teaching their students. Our main objective was to analyze the cell biology content currently being taught in Brazilian universities. We collected the syllabi of cell biology courses from public universities in Brazil and analyzed the frequency of cell biology topics in each course. We also compared the Brazilian data with the contents of a major cell biology textbook. Our analysis showed that while some cell biology topics such as plasma membrane and cytoskeleton was present in ∼100% of the Brazilian curricula analyzed others such as cell signaling and cell differentiation were present in only ∼35%. The average cell biology content taught in the Brazilian universities is quite different from what is presented in the textbook. We discuss several possible explanations for these observations. We also suggest a list with essential cell biology topics for any biological or biomedical undergraduate course. The comparative discussion of cell biology topics presented here could be valuable in other educational contexts. © 2017 The Authors. Cell Biology International Published by John Wiley & Sons Ltd on behalf of International Federation of Cell Biology.

Foreword: Surface Tensions: Between Explanation and Understanding.

Science.gov (United States)

Blauvelt, Andrew

1995-01-01

Introduces this issue of the journal, which is devoted to new perspectives on critical histories of graphic design. Notes that the essays in this issue offer examples of the variety of interpretative approaches available that serve to question both the previously unchallenged acceptance of historical explanations and the transcendent understanding…

Impact of Self-Explanation and Analogical Comparison Support on Learning Processes, Motivation, Metacognition, and Transfer

Science.gov (United States)

Richey, J. Elizabeth

Research examining analogical comparison and self-explanation has produced a robust set of findings about learning and transfer supported by each instructional technique. However, it is unclear how the types of knowledge generated through each technique differ, which has important implications for cognitive theory as well as instructional practice. I conducted a pair of experiments to directly compare the effects of instructional prompts supporting self-explanation, analogical comparison, and the study of instructional explanations across a number of fine-grained learning process, motivation, metacognition, and transfer measures. Experiment 1 explored these questions using sequence extrapolation problems, and results showed no differences between self-explanation and analogical comparison support conditions on any measure. Experiment 2 explored the same questions in a science domain. I evaluated condition effects on transfer outcomes; self-reported self-explanation, analogical comparison, and metacognitive processes; and achievement goals. I also examined relations between transfer and self-reported processes and goals. Receiving materials with analogical comparison support and reporting greater levels of analogical comparison were both associated with worse transfer performance, while reporting greater levels of self-explanation was associated with better performance. Learners' self-reports of self-explanation and analogical comparison were not related to condition assignment, suggesting that the questionnaires did not measure the same processes promoted by the intervention, or that individual differences in processing are robust even when learners are instructed to engage in self-explanation or analogical comparison.

David Hull's generalized natural selection as an explanation for scientific change

Science.gov (United States)

Little, Michelle Yvette

2001-10-01

Philosophers of science such as Karl Popper and Thomas Kuhn have employed evolutionary idiom in describing scientific change. In Science as a Process (1988) Hull makes evolutionary theory explanatorily applicable. He modifies key evolutionary terms in order that both biological evolution and scientific change are instances of a general selection process. According to Hull, because of naturally-existing competition for credit among researchers and the professional lineages they constitute, scientists are constrained to cooperate and collaborate. This process entails two important philosophical consequences. First, it allows for a natural justification of why the sciences can provide objective empirical knowledge. Second, appreciating its strength means that a philosophical analysis of scientific change is solidly difficult features to combine. I work on strengthening two weaknesses in Hull's arguments. First, operating in his analysis is an unexplicated notion of ``information'' running parallel to the equally opaque notion of genetic information. My third chapter provides a clear account of ``genetic information'' whose usefulness extends beyond the assistance it can render Hull as a clear concept is needed in biological contexts as well. The fourth and fifth chapters submit evidence of scientific change from radio astronomy. Hull insists on empirical backing for philosophical theses but his own book stands to suffer from selection effects as it offers cases drawn from a single subspecialty in the biological sciences. I found that in the main scientists and the change they propel accords well with Hull's explanation. However, instances of major change reveal credit- and resource-sharing to a degree contrary with what Hull would expect. My conclusion is that the naturalness of competition, instantiated during the course of standardized and relatively ``normal'' scientific research, is not the norm during periods of new research and its uncertain standards of

Phase space overpopulation at CERN and possible explanations

International Nuclear Information System (INIS)

Pratt, S.

1998-01-01

By combining information from correlations from Pb+Pb collisions at CERN, one comes to the conclusion that pionic phase space is significantly overpopulated compared to expectations based on chemical equilibrium. A variety of explanations will be addressed. (author)

The 'side effects' of medicalization: a meta-analytic review of how biogenetic explanations affect stigma.

Science.gov (United States)

Kvaale, Erlend P; Haslam, Nick; Gottdiener, William H

2013-08-01

Reducing stigma is crucial for facilitating recovery from psychological problems. Viewing these problems biomedically may reduce the tendency to blame affected persons, but critics have cautioned that it could also increase other facets of stigma. We report on the first meta-analytic review of the effects of biogenetic explanations on stigma. A comprehensive search yielded 28 eligible experimental studies. Four separate meta-analyses (Ns=1207-3469) assessed the effects of biogenetic explanations on blame, perceived dangerousness, social distance, and prognostic pessimism. We found that biogenetic explanations reduce blame (Hedges g=-0.324) but induce pessimism (Hedges g=0.263). We also found that biogenetic explanations increase endorsement of the stereotype that people with psychological problems are dangerous (Hedges g=0.198), although this result could reflect publication bias. Finally, we found that biogenetic explanations do not typically affect social distance. Promoting biogenetic explanations to alleviate blame may induce pessimism and set the stage for self-fulfilling prophecies that could hamper recovery from psychological problems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Folk-Psychological Interpretation of Human vs. Humanoid Robot Behavior: Exploring the Intentional Stance toward Robots.

Science.gov (United States)

Thellman, Sam; Silvervarg, Annika; Ziemke, Tom

2017-01-01

People rely on shared folk-psychological theories when judging behavior. These theories guide people's social interactions and therefore need to be taken into consideration in the design of robots and other autonomous systems expected to interact socially with people. It is, however, not yet clear to what degree the mechanisms that underlie people's judgments of robot behavior overlap or differ from the case of human or animal behavior. To explore this issue, participants ( N = 90) were exposed to images and verbal descriptions of eight different behaviors exhibited either by a person or a humanoid robot. Participants were asked to rate the intentionality, controllability and desirability of the behaviors, and to judge the plausibility of seven different types of explanations derived from a recently proposed psychological model of lay causal explanation of human behavior. Results indicate: substantially similar judgments of human and robot behavior, both in terms of (1a) ascriptions of intentionality/controllability/desirability and in terms of (1b) plausibility judgments of behavior explanations; (2a) high level of agreement in judgments of robot behavior - (2b) slightly lower but still largely similar to agreement over human behaviors; (3) systematic differences in judgments concerning the plausibility of goals and dispositions as explanations of human vs. humanoid behavior. Taken together, these results suggest that people's intentional stance toward the robot was in this case very similar to their stance toward the human.

What Do Students' Explanations Look Like When They Use Second-Hand Data?

Science.gov (United States)

Delen, Ibrahim; Krajcik, Joseph

2015-01-01

Explanation studies underlined the importance of using evidence in support of claims. However, few studies have focused on students' use of others' data (second-hand data) in this process. In this study, students collected data from a local water source and then took all the data back to the classroom to create scientific explanations by using…

More on Grandmother Cells and the Biological Implausibility of PDP Models of Cognition: A Reply to Plaut and McClelland (2010) and Quian Quiroga and Kreiman (2010)

Science.gov (United States)

Bowers, Jeffrey S.

2010-01-01

Plaut and McClelland (2010) and Quian Quiroga and Kreiman both challenged my characterization of localist and distributed representations. They also challenged the biological plausibility of grandmother cells on conceptual and empirical grounds. This reply addresses these issues in turn. The premise of my argument is that grandmother cells in…

75 FR 75453 - Proposed Information Collection; Comment Request; Technical Data Letter of Explanation

Science.gov (United States)

2010-12-03

... Request; Technical Data Letter of Explanation AGENCY: Bureau of Industry and Security. ACTION: Notice....gov . SUPPLEMENTARY INFORMATION: I. Abstract These technical data letters of explanation will assure the Bureau of Industry and Security that U.S.-origin technical data will be exported only for...

Problems in the radon versus lung cancer test of the linear no-threshold theory and a procedure for resolving them

International Nuclear Information System (INIS)

Cohen, B.L.

1996-01-01

It has been shown that lung cancer rates in U.S. counties, with or without correction for smoking, decrease with increasing radon exposure, in sharp contrast to the increase predicted by the linear-no-threshold (LNT) theory. The discrepancy is by 20 standard deviations, and very extensive efforts to explain it were not successful. Unless a plausible explanation for this discrepancy (or conflicting evidence) can be found, continued use of the LNT theory is a violation of open-quotes the scientific method.close quotes Nevertheless, LNT continues to be accepted and used by all official and governmental organizations, such as the International Commission on Radiological Protection, the National Council on Radiation Protection and Measurements, the Council on Radiation Protection and Measurements, the National Academy of Sciences - U.S. Nuclear Regulatory Commission Board of Radiation Effects Research, Environmental Protection Agency etc., and there has been no move by any of these bodies to discontinue or limit its use. Assuming that they rely on the scientific method, this clearly implies that they have a plausible explanation for the discrepancy. The author has made great efforts to discover these 'plausible explanations' by inquiries through various channels, and the purpose of this paper is to describe and discuss them

Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories.

Science.gov (United States)

Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

2016-09-01

Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance.

The United States and biological warfare: secrets from the early cold war and Korea.

Science.gov (United States)

Bruwer, A

2001-01-01

The United States and Biological Warfare is about accusations that the United States resorted to bacteriological warfare at a time of great military stress during the Korean War. In December 1951, the then US Secretary of Defense ordered early readiness for offensive use of biological weapons. Soon afterwards, the North Korean and Chinese armies accused the United States of starting a large-scale biological warfare experiment in Korea. The US State Department denied the accusation. Both parties to the dispute maintain their positions today. The authors spent 20 years researching the accusations in North America, Europe and Japan. They were the first foreigners to be given access to Chinese classified documents. The reader is also introduced to the concept of 'plausible denial', an official US policy which allowed responsible governmental representatives to deny knowledge of certain events. The authors hope that their work will contribute to the understanding of a time when modern war expanded into a new type of violence.

The Improvement of Simple Explanation and Inferencetion Skills with Problem Solving

OpenAIRE

Dewanti, Fransiska Olivia; Diawati, Chansyanah; Fadiawati, Noor

2013-01-01

The learning process is strongly influenced by the ability and accuracy of teachers in selecting and applying the learning model. The model can be applied to improve of  simple explanation and inferencetion skill is a model of problem solving. The purpose of this study was to describe the model of problem solving that are effective in improving simple explanation and inferencetion skills on the material electrolyte and non-electrolyte solution. This research use a quasi-experimental methods ...

32 CFR 516.3 - Explanation of abbreviations and terms.

Science.gov (United States)

2010-07-01

... Glossary contains explanations of abbreviations and terms. (b) The masculine gender has been used throughout this regulation for simplicity and consistency. Any reference to the masculine gender is intended...

Investigating Undergraduate Students’ Use of Intuitive Reasoning and Evolutionary Knowledge in Explanations of Antibiotic Resistance

Science.gov (United States)

Richard, Melissa; Coley, John D.; Tanner, Kimberly D.

2017-01-01

Natural selection is a central concept throughout biology; however, it is a process frequently misunderstood. Bacterial resistance to antibiotic medications provides a contextual example of the relevance of evolutionary theory and is also commonly misunderstood. While research has shed light on student misconceptions of natural selection, minimal study has focused on misconceptions of antibiotic resistance. Additionally, research has focused on the degree to which misconceptions may be based in the complexity of biological information or in pedagogical choices, rather than in deep-seated cognitive patterns. Cognitive psychology research has established that humans develop early intuitive assumptions to make sense of the world. In this study, we used a written assessment tool to investigate undergraduate students’ misconceptions of antibiotic resistance, use of intuitive reasoning, and application of evolutionary knowledge to antibiotic resistance. We found a majority of students produced and agreed with misconceptions, and intuitive reasoning was present in nearly all students’ written explanations. Acceptance of a misconception was significantly associated with production of a hypothesized form of intuitive thinking (all p ≤ 0.05). Intuitive reasoning may represent a subtle but innately appealing linguistic shorthand, and instructor awareness of intuitive reasoning’s relation to student misunderstandings has potential for addressing persistent misconceptions. PMID:28821540

Learning the Language of Evolution: Lexical Ambiguity and Word Meaning in Student Explanations

Science.gov (United States)

Rector, Meghan A.; Nehm, Ross H.; Pearl, Dennis

2013-01-01

Our study investigates the challenges introduced by students' use of lexically ambiguous language in evolutionary explanations. Specifically, we examined students' meaning of five key terms incorporated into their written evolutionary explanations: "pressure", "select", "adapt", "need", and "must". We utilized a new technological tool known as the…

Investigating the Development of Chinese Oral Explanation and Justification in Singapore Primary Students

Science.gov (United States)

Yan, Jing

2016-01-01

Explanation and justification require cognitive ability which selects and organises relevant information in a logical way, and linguistic ability which enables speakers to encode the information with linguistic knowledge. This study aims to investigate the development of Chinese oral explanation and justification in Singapore primary students. The…

Biology experiments at UNILAC. Reports from the biology user meeting, GSI, 3 October 1985

International Nuclear Information System (INIS)

1985-10-01

On 3 Oct 1985, an internal Biology User Meeting of the groups working at GSI was arranged for the purpose of exchanging information and having discussions. It was found that the experimental data obtained so far are quite complex, and that the attempts at a theoretical treatment are still in a very early stage. To keep the discussion going, this report therefore presents the contributions of the various groups as far as these have been available. Most of the information was not in finished reports but in the form of diagrams and tables with explanations, sometimes even in the form of handwritten notes or sketches. Separate records are available for 13 contributions. (orig./MG) [de

Phase space overpopulation at CERN and possible explanations

International Nuclear Information System (INIS)

Pratt, S.

1999-01-01

Complete text of publication follows. By combining information from correlations from Pb+Pb collisions at CERN, one comes to the conclusion that pionic phase space is significantly overpopulated compared to expectations based on chemical equilibrium. A variety of explanations will be addressed. (author)

Negotiating explanations: doctor-patient communication with patients with medically unexplained symptoms-a qualitative analysis.

Science.gov (United States)

den Boeft, Madelon; Huisman, Daniëlle; Morton, LaKrista; Lucassen, Peter; van der Wouden, Johannes C; Westerman, Marjan J; van der Horst, Henriëtte E; Burton, Christopher D

2017-02-01

Patients with medically unexplained physical symptoms (MUPS) seek explanations for their symptoms, but often find general practitioners (GPs) unable to deliver these. Different methods of explaining MUPS have been proposed. Little is known about how communication evolves around these explanations. To examine the dialogue between GPs and patients related to explanations in a community-based clinic for MUPS. We categorized dialogue types and dialogue outcomes. Patients were ≥18 years with inclusion criteria for moderate MUPS: ≥2 referrals to specialists, ≥1 functional syndrome/symptoms, ≥10 on the Patient Health Questionnaire-15 and GP's judgement that symptoms were unexplained. We analysed transcripts of 112 audio-recorded consultations (39 patients and 5 GPs) from two studies on the Symptoms Clinic Intervention, a consultation intervention for MUPS in primary care. We used constant comparative analysis to code and classify dialogue types and outcomes. We extracted 115 explanation sequences. We identified four dialogue types, differing in the extent to which the GP or patient controlled the dialogue. We categorized eight outcomes of the sequences, ranging from acceptance to rejection by the patient. The most common outcome was holding (conversation suspended in an unresolved state), followed by acceptance. Few explanations were rejected by the patient. Co-created explanations by patient and GP were most likely to be accepted. We developed a classification of dialogue types and outcomes in relation to explanations offered by GPs for MUPS patients. While it requires further validation, it provides a framework, which can be used for teaching, evaluation of practice and research. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Biological phosphorus uptake under anoxic and aerobic conditions

DEFF Research Database (Denmark)

Kerrn-Jespersen, Jens Peter; Henze, Mogens

1993-01-01

Biological phosphorus removal was investigated under anoxic and aerobic conditions. Tests were made to establish whether phosphorus accumulating bacteria can take up phosphate under anoxic conditions and thus utilise nitrate as oxidant. Furthermore, it was tested how the amount of organic matter...... as oxidant. The phosphorus uptake was more rapid under aerobic conditions than under anoxic conditions. The explanation of this is that all phosphorus accumulating bacteria take up phosphate under aerobic conditions, whereas only part of the phosphorus accumulating bacteria take up phosphate under anoxic...

Influence of biological, experiential and psychological factors in wine preference segmentation.

Science.gov (United States)

Pickering, Gary J; Hayes, John E

2017-06-01

We sought to determine the influence of selected biological, experiential and psychological variables on self-reported liking and consumption of wine in a sample of 329 Ontario wine consumers. Cluster analysis revealed three distinct groups, representing plausible market segments: wine lovers; dry table wine likers/sweet dislikers; and sweet wine likers/fortified dislikers. These groups differ in level of wine expertise, wine adventurousness, alcohol intake, bitterness from 6- n -propylthiouracil (PROP), and several demographic variables. PROP hypo-tasters ( n =113) and PROP hyper-tasters ( n =112) differed in liking scores for nine of the 11 wine styles [ANCOVA, P (F)branding and marketing strategies.

Sex Differences in Social Behavior: Are the Social Role and Evolutionary Explanations Compatible?

Science.gov (United States)

Archer, John

1996-01-01

Examines competing claims of two explanations of sex differences in social behavior, social role theory, and evolutionary psychology. Findings associated with social role theory are weighed against evolutionary explanations. It is suggested that evolutionary theory better accounts for the overall pattern of sex differences and for their origins.…

Quantum theory as plausible reasoning applied to data obtained by robust experiments.

Science.gov (United States)

De Raedt, H; Katsnelson, M I; Michielsen, K

2016-05-28

We review recent work that employs the framework of logical inference to establish a bridge between data gathered through experiments and their objective description in terms of human-made concepts. It is shown that logical inference applied to experiments for which the observed events are independent and for which the frequency distribution of these events is robust with respect to small changes of the conditions under which the experiments are carried out yields, without introducing any concept of quantum theory, the quantum theoretical description in terms of the Schrödinger or the Pauli equation, the Stern-Gerlach or Einstein-Podolsky-Rosen-Bohm experiments. The extraordinary descriptive power of quantum theory then follows from the fact that it is plausible reasoning, that is common sense, applied to reproducible and robust experimental data. © 2016 The Author(s).

A Self-Categorization Explanation for Opinion Consensus Perceptions

Science.gov (United States)

Zhang, Jinguang; Reid, Scott A.

2013-01-01

The public expression of opinions (and related communicative activities) hinges upon the perception of opinion consensus. Current explanations for opinion consensus perceptions typically focus on egocentric and other biases, rather than functional cognitions. Using self-categorization theory we showed that opinion consensus perceptions flow from…

Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories

Science.gov (United States)

Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

2016-01-01

ABSTRACT Background: Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Methods: Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. Findings: One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. Discussion: There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance. PMID:26854092

An ancient explanation of presbyopia based on binocular vision.

Science.gov (United States)

Barbero, Sergio

2014-06-01

Presbyopia, understood as the age-related loss of ability to clearly see near objects, was known to ancient Greeks. However, few references to it can be found in ancient manuscripts. A relevant discussion on presbyopia appears in a book called Symposiacs written by Lucius Mestrius Plutarchus around 100 A.C. In this work, Plutarch provided four explanations of presbyopia, associated with different theories of vision. One of the explanations is particularly interesting as it is based on a binocular theory of vision. In this theory, vision is produced when visual rays, emanating from the eyes, form visual cones that impinge on the objects to be seen. Visual rays coming from old people's eyes, it was supposed, are weaker than those from younger people's eyes; so the theory, to be logically coherent, implies that this effect is compensated by the increase in light intensity due to the overlapping, at a certain distance, of the visual cones coming from both eyes. Thus, it benefits the reader to move the reading text further away from the eyes in order to increase the fusion area of both visual cones. The historical hypothesis taking into consideration that the astronomer Hipparchus of Nicaea was the source of Plutarch's explanation of the theory is discussed. © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Structure before meaning: sentence processing, plausibility, and subcategorization.

Science.gov (United States)

Kizach, Johannes; Nyvad, Anne Mette; Christensen, Ken Ramshøj

2013-01-01

Natural language processing is a fast and automatized process. A crucial part of this process is parsing, the online incremental construction of a syntactic structure. The aim of this study was to test whether a wh-filler extracted from an embedded clause is initially attached as the object of the matrix verb with subsequent reanalysis, and if so, whether the plausibility of such an attachment has an effect on reaction time. Finally, we wanted to examine whether subcategorization plays a role. We used a method called G-Maze to measure response time in a self-paced reading design. The experiments confirmed that there is early attachment of fillers to the matrix verb. When this attachment is implausible, the off-line acceptability of the whole sentence is significantly reduced. The on-line results showed that G-Maze was highly suited for this type of experiment. In accordance with our predictions, the results suggest that the parser ignores (or has no access to information about) implausibility and attaches fillers as soon as possible to the matrix verb. However, the results also show that the parser uses the subcategorization frame of the matrix verb. In short, the parser ignores semantic information and allows implausible attachments but adheres to information about which type of object a verb can take, ensuring that the parser does not make impossible attachments. We argue that the evidence supports a syntactic parser informed by syntactic cues, rather than one guided by semantic cues or one that is blind, or completely autonomous.

Structure before meaning: sentence processing, plausibility, and subcategorization.

Directory of Open Access Journals (Sweden)

Johannes Kizach

Full Text Available Natural language processing is a fast and automatized process. A crucial part of this process is parsing, the online incremental construction of a syntactic structure. The aim of this study was to test whether a wh-filler extracted from an embedded clause is initially attached as the object of the matrix verb with subsequent reanalysis, and if so, whether the plausibility of such an attachment has an effect on reaction time. Finally, we wanted to examine whether subcategorization plays a role. We used a method called G-Maze to measure response time in a self-paced reading design. The experiments confirmed that there is early attachment of fillers to the matrix verb. When this attachment is implausible, the off-line acceptability of the whole sentence is significantly reduced. The on-line results showed that G-Maze was highly suited for this type of experiment. In accordance with our predictions, the results suggest that the parser ignores (or has no access to information about implausibility and attaches fillers as soon as possible to the matrix verb. However, the results also show that the parser uses the subcategorization frame of the matrix verb. In short, the parser ignores semantic information and allows implausible attachments but adheres to information about which type of object a verb can take, ensuring that the parser does not make impossible attachments. We argue that the evidence supports a syntactic parser informed by syntactic cues, rather than one guided by semantic cues or one that is blind, or completely autonomous.

Competing explanations for adopting energy innovations for new office buildings

International Nuclear Information System (INIS)

Vermeulen, Walter J.V.; Hovens, Jeroen

2006-01-01

An integrative model to explain potential adopters' decisions to adopt energy innovations was adapted and applied in the field of new office building construction. We tested the relative effects of competing theoretical explanations (derived from economics, innovation science and policy science) on the decision to adopt. The research covered 35 projects representing 9% of the total volume of new office construction in the Netherlands between 2000 and mid-2002. Two levels of explanations for adopting innovations were derived: (a) the potential adopter's weighed assessments of the innovations and his or her nature of decision making and (b) explanation of those first-level variables. Using multiple regression techniques, we determined the relative influence on innovation-adoption of variables covering economy and technology, government intervention, company characteristics, and influences from market and society. The decision to adopt 'mature' innovations, in contrast to 'young' innovations, is based more on routine procedures than project-specific considerations. Policies need to take this difference into consideration. We also show evidence that in promoting adoption of E-innovations for new office buildings the Dutch system of applying Energy Performance Standards and subsidies proofs to be effective

Infant Preferences for Attractive Faces: A Cognitive Explanation.

Science.gov (United States)

Rubenstein, Adam J.; Kalakanis, Lisa; Langlois, Judith H.

1999-01-01

Four studies assessed a cognitive explanation for development of infants' preference for attractive faces: cognitive averaging and preferences for mathematically averaged faces, or prototypes. Findings indicated that adults and 6-month olds prefer prototypical, mathematically averaged faces and that 6-month olds can abstract the central tendency…

Psychosocial explanations of complaints in Dutch general practice

NARCIS (Netherlands)

Joosten, A; Mazeland, H; Meyboom-de Jong, B

BACKGROUND: Dutch GPs are frequently consulted by patients presenting physical complaints which have a psychosocial cause. Until now, this type of complaint has often been the subject of study, but the way in which psychosocial explanations for complaints are broached and discussed has not yet been

A guide on instrument of biochemistry and molecular biology

International Nuclear Information System (INIS)

1995-10-01

This book is about instrument on biochemistry and molecular biology, which consists of six chapters. It deals with introduction of advanced bio-instrument, common utilization and maintain, explanation of each instrument like capillary electrophoresis, interactive laser cytometer, personal computer and software, an electron microscope and DNA/RNS synthesis instrument, large equipment and special system like information system and network, analysis system for genome and large spectro graph, outside donation, examples for common utilization and appendix on data like application form for use.

Nicotine dose-concentration relationship and pregnancy outcomes in rat: Biologic plausibility and implications for future research

International Nuclear Information System (INIS)

Hussein, Jabeen; Farkas, Svetlana; MacKinnon, Yolanda; Ariano, Robert E.; Sitar, Daniel S.; Hasan, Shabih U.

2007-01-01

Cigarette smoke (CS) exposure during pregnancy can lead to profound adverse effects on fetal development. Although CS contains several thousand chemicals, nicotine has been widely used as its surrogate as well as in its own right as a neuroteratogen. The justification for the route and dose of nicotine administration is largely based on inferential data suggesting that nicotine 6 mg/kg/day infused continuously via osmotic mini pumps (OMP) would mimic maternal CS exposure. We provide evidence that 6 mg/kg/day nicotine dose as commonly administered to pregnant rats leads to plasma nicotine concentrations that are 3-10-fold higher than those observed in moderate to heavy smokers and pregnant mothers, respectively. Furthermore, the cumulative daily nicotine dose exceeds by several hundred fold the amount consumed by human heavy smokers. Our study does not support the widely accepted notion that regardless of the nicotine dose, a linear nicotine dose-concentration relationship exists in a steady-state OMP model. We also show that total nicotine clearance increases with advancing pregnancy but no significant change is observed between the 2nd and 3rd trimester. Furthermore, nicotine infusion even at this extremely high dose has little effect on a number of maternal and fetal biologic variables and pregnancy outcome suggesting that CS constituents other than nicotine mediate the fetal growth restriction in infants born to smoking mothers. Our current study has major implications for translational research in developmental toxicology and pharmacotherapy using nicotine replacement treatment as an aid to cessation of cigarette smoking in pregnant mothers

A flat space-time relativistic explanation for the perihelion advance of Mercury

OpenAIRE

Behera, Harihar; Naik, P. C.

2003-01-01

Starting with the flat space-time relativistic versions of Maxwell-Heaviside's toy model vector theory of gravity and introducing the gravitational analogues for the electromagnetic Lienard-Wiechert potentials together with the notion of a gravitational Thomas Precession; the observed anomalous perihelion advance of Mercury's orbit is here explained as a relativistic effect in flat (Minkowski) space-time, unlike Einstein's curved space-time relativistic explanation. In this new explanation fo...

Influence of biological, experiential and psychological factors in wine preference segmentation

Science.gov (United States)

Pickering, Gary J; Hayes, John E

2016-01-01

Background and Aims We sought to determine the influence of selected biological, experiential and psychological variables on self-reported liking and consumption of wine in a sample of 329 Ontario wine consumers. Methods and Results Cluster analysis revealed three distinct groups, representing plausible market segments: wine lovers; dry table wine likers/sweet dislikers; and sweet wine likers/fortified dislikers. These groups differ in level of wine expertise, wine adventurousness, alcohol intake, bitterness from 6-n-propylthiouracil (PROP), and several demographic variables. PROP hypo-tasters (n=113) and PROP hyper-tasters (n=112) differed in liking scores for nine of the 11 wine styles [ANCOVA, P(F)variables examined. Taste phenotype also contributes significantly to variation in wine liking. Significance of the Study Ontario wine consumers fall into one of three wine liking clusters, which differ in experiential, biological, psychological and demographic features that can be targeted through branding and marketing strategies. PMID:28579910

Event-based plausibility immediately influences on-line language comprehension.

Science.gov (United States)

Matsuki, Kazunaga; Chow, Tracy; Hare, Mary; Elman, Jeffrey L; Scheepers, Christoph; McRae, Ken

2011-07-01

In some theories of sentence comprehension, linguistically relevant lexical knowledge, such as selectional restrictions, is privileged in terms of the time-course of its access and influence. We examined whether event knowledge computed by combining multiple concepts can rapidly influence language understanding even in the absence of selectional restriction violations. Specifically, we investigated whether instruments can combine with actions to influence comprehension of ensuing patients of (as in Rayner, Warren, Juhuasz, & Liversedge, 2004; Warren & McConnell, 2007). Instrument-verb-patient triplets were created in a norming study designed to tap directly into event knowledge. In self-paced reading (Experiment 1), participants were faster to read patient nouns, such as hair, when they were typical of the instrument-action pair (Donna used the shampoo to wash vs. the hose to wash). Experiment 2 showed that these results were not due to direct instrument-patient relations. Experiment 3 replicated Experiment 1 using eyetracking, with effects of event typicality observed in first fixation and gaze durations on the patient noun. This research demonstrates that conceptual event-based expectations are computed and used rapidly and dynamically during on-line language comprehension. We discuss relationships among plausibility and predictability, as well as their implications. We conclude that selectional restrictions may be best considered as event-based conceptual knowledge rather than lexical-grammatical knowledge.

Semantics-based plausible reasoning to extend the knowledge coverage of medical knowledge bases for improved clinical decision support

OpenAIRE

Mohammadhassanzadeh, Hossein; Van Woensel, William; Abidi, Samina Raza; Abidi, Syed Sibte Raza

2017-01-01

Background Capturing complete medical knowledge is challenging-often due to incomplete patient Electronic Health Records (EHR), but also because of valuable, tacit medical knowledge hidden away in physicians? experiences. To extend the coverage of incomplete medical knowledge-based systems beyond their deductive closure, and thus enhance their decision-support capabilities, we argue that innovative, multi-strategy reasoning approaches should be applied. In particular, plausible reasoning mech...

Prediction and explanation over DL-Lite data streams

CSIR Research Space (South Africa)

Klarman, S

2013-12-01

Full Text Available the popular DL-Lite family, and study the logic foundations of prediction and explanation over DL-Lite data streams, i.e., reasoning from finite segments of streaming data to conjectures about the content of the streams in the future or in the past. We propose...

Biogenetic explanations and stigma: a meta-analytic review of associations among laypeople.

Science.gov (United States)

Kvaale, Erlend P; Gottdiener, William H; Haslam, Nick

2013-11-01

The stigma and social rejection faced by people with a mental disorder constitute a major barrier to their well-being and recovery. Medicalization has been welcomed as a strategy to reduce blame and stigma, although critics have cautioned that attributing mental disorders to biogenetic causes may have unintended side effects that could exacerbate prejudice and rejection. The present study presents a quantitative synthesis of the literature on relationships between biogenetic explanations for mental disorders and three key elements of stigma, namely blame, perceptions of dangerousness, and social distance. A comprehensive search yielded 25 studies meeting the inclusion criteria. Separate meta-analyses (Ns = 4278-23,816) were conducted for the three stigma types, and assessed the consistency of effects across subgroups of studies involving different types of biogenetic explanations, mental disorders, and samples. We found that people who hold biogenetic explanations for mental disorders tend to blame affected persons less for their problems (r = -0.19), but perceive them as more dangerous (r = 0.09) and desire more distance from them (r = 0.05). The negative association with blame was significant for schizophrenia, belief in genetic causation, and in student samples. The positive association with dangerousness was significant for all disorders, belief in general biogenetic causation, and in community samples. The positive association with social distance was significant for schizophrenia, beliefs in neurochemical and general biogenetic causation, and in community samples. Nevertheless, across all analyses, biogenetic explanations were only weakly related to stigma. We conclude that biogenetic explanations for mental disorders confer mixed blessings for stigma. Copyright © 2013 Elsevier Ltd. All rights reserved.

Learning can be all Fun and Games: Constructing and Utilizing a Biology Taboo Wiktionary to Enhance Student Learning in an Introductory Biology Course

Directory of Open Access Journals (Sweden)

Jeffrey T. Olimpo

2010-10-01

Full Text Available Most introductory courses in the biological sciences are inherently content-dense and rich with jargon—jargon that is often confusing and nonsensical to novice students. These characteristics present an additional paradox to instructors, who strive to achieve a balance between simply promoting passive, rote memorization of facts and engaging students in developing true, concrete understanding of the terminology. To address these concerns, we developed and implemented a Biology Taboo Wiktionary that provided students with an interactive opportunity to review and describe concepts they had encountered during their first semester of introductory biology. However, much like the traditional Taboo game, the rules were such that students could not use obvious terms to detail the main term. It was our belief that if the student could synthesize a thoughtful, scientific explanation of the term under these conditions, he or she demonstrated a true understanding of the conceptual context and meaning of the term.

Causal explanations of distress and general practitioners' assessments of common mental disorder among punjabi and English attendees.

Science.gov (United States)

Bhui, Kamaldeep; Bhugra, Dinesh; Goldberg, David

2002-01-01

The literature on the primary care assessment of mental distress among Indian subcontinent origin patients suggests frequent presentations to general practitioner, but rarely for recognisable psychiatric disorders. This study investigates whether cultural variations in patients' causal explanatory models account for cultural variations in the assessment of non-psychotic mental disorders in primary care. In a two-phase survey, 272 Punjabi and 269 English subjects were screened. The second phase was completed by 209 and 180 subjects, respectively. Causal explanatory models were elicited as explanations of two vignette scenarios. One of these emphasised a somatic presentation and the other anxiety symptoms. Psychiatric disorder was assessed by GPs on a Likert scale and by a psychiatrist on the Clinical Interview Schedule. Punjabis more commonly expressed medical/somatic and religious beliefs. General practitioners were more likely to assess any subject giving psychological explanations to vignette A and English subjects giving religious explanations to vignette B as having a significant psychiatric disorder. Where medical/somatic explanations of distress were most prevalent in response to the somatic vignette, psychological, religious and work explanations were less prevalent among Punjabis but not among English subjects. Causal explanations did not fully explain cultural differences in assessments. General practitioners' assessments and causal explanations are related and influenced by culture, but causal explanations do not fully explain cultural differences in assessments.

On Matrix Sampling and Imputation of Context Questionnaires with Implications for the Generation of Plausible Values in Large-Scale Assessments

Science.gov (United States)

Kaplan, David; Su, Dan

2016-01-01

This article presents findings on the consequences of matrix sampling of context questionnaires for the generation of plausible values in large-scale assessments. Three studies are conducted. Study 1 uses data from PISA 2012 to examine several different forms of missing data imputation within the chained equations framework: predictive mean…

The Sarrazin effect: the presence of absurd statements in conspiracy theories makes canonical information less plausible.

Science.gov (United States)

Raab, Marius Hans; Auer, Nikolas; Ortlieb, Stefan A; Carbon, Claus-Christian

2013-01-01

Reptile prime ministers and flying Nazi saucers-extreme and sometimes off-wall conclusion are typical ingredients of conspiracy theories. While individual differences are a common research topic concerning conspiracy theories, the role of extreme statements in the process of acquiring and passing on conspiratorial stories has not been regarded in an experimental design so far. We identified six morphological components of conspiracy theories empirically. On the basis of these content categories a set of narrative elements for a 9/11 story was compiled. These elements varied systematically in terms of conspiratorial allegation, i.e., they contained official statements concerning the events of 9/11, statements alleging to a conspiracy limited in time and space as well as extreme statements indicating an all-encompassing cover-up. Using the method of narrative construction, 30 people were given a set of cards with these statements and asked to construct the course of events of 9/11 they deem most plausible. When extreme statements were present in the set, the resulting stories were more conspiratorial; the number of official statements included in the narrative dropped significantly, whereas the self-assessment of the story's plausibility did not differ between conditions. This indicates that blatant statements in a pool of information foster the synthesis of conspiracy theories on an individual level. By relating these findings to one of Germany's most successful (and controversial) non-fiction books, we refer to the real-world dangers of this effect.

The Effects of Two Reality Explanations on Children's Reactions to a Frightening Movie Scene.

Science.gov (United States)

Wilson, Barbara J.; Weiss, Audrey J.

1991-01-01

Assesses the effectiveness of two reality explanations on children's reactions to frightening programs. Shows that neither influenced younger children's emotional or cognitive reactions, whereas the special tricks explanation reduced older children's emotional responses with no impact on their interpretation. Shows that the real life explanation…

Older persons' definitions and explanations of elder abuse in the Netherlands.

Science.gov (United States)

Mysyuk, Yuliya; Westendorp, Rudi G J; Lindenberg, Jolanda

2016-01-01

In this article we explore older persons' definitions of and explanations for elder abuse in the Netherlands by means of interviews with older persons. A qualitative study was conducted based on semistructured interviews with 35 older persons who had no experience with abuse. Our findings show that older persons participating in our study define elder abuse foremost as physical violence that is performed intentionally. The study participants explain elder abuse as a result of the dependency and vulnerability of older persons, of changing norms and values, and of changes in the position of older persons in society, which result in disrespect toward older persons and a lack of social control and responsibility. The older persons' explanations for the occurrence of abuse mainly focus on societal changes; older persons seem to regard elder abuse primarily as a societal problem. This understanding of, and explanation for, elder abuse may influence their detection and reporting behavior, as they may tend to acknowledge only severe cases of intentional physical violence that leave clear and therefore physically detectable evidence.

Spectral Mixing in Nervous Systems: Experimental Evidenceand Biologically Plausible Circuits

Science.gov (United States)

Kleinfeld, D.; Mehta, S. B.

The ability to compute the difference frequency for two periodic signals depends on a nonlinear operation that mixes those signals. Behavioral and psychophysical evidence suggest that such mixing is likely to occur in the vertebrate nervous system as a means to compare rhythmic sensory signals, such as occurs in human audition, and as a means to lock an intrinsic rhythm to a sensory input. Electrophysiological data from electroreceptors in the immobilized electric fish and somatosensory cortex in the anesthetized rat yield direct evidence for such mixing, providing a neurological substrate for the modulation and demodulation of rhythmic neuronal signals. We consider an analytical model of spectral mixing that makes use of the threshold characteristics of neuronal firing and which has features consistent with the experimental observations. This model serves as a guide for constructing circuits that isolate given mixture components. In particular, such circuits can generate nearly pure difference tones from sinusoidal inputs without the use of band-pass filters, in analogy to an image-reject mixer in communications engineering. We speculate that such computations may play a role in coding of sensory input and feedback stabilization of motor output in nervous systems.

Why have socio-economic explanations between favoured over ...

African Journals Online (AJOL)

explanations trump cultural ones in the South African HIV aetiological literature? In this article, we explore how three factors (a belief in monogamy as a universal norm, HIV's emergence in a time of the construction of non-racialism, and a simplified understanding of HIV epidemiology) have intersected to produce this bias ...

An Explanation of Economic Change and Development

OpenAIRE

Fusari, Angelo

2014-01-01

The contribution to the explanation of economic change that this paper sets out is centered on a core of interconnected endogenous variables, mainly innovation, radical uncertainty and entrepreneurship, which current economic analyses consider only in part and separately, sometimes as endogenous but for the most as exogenous. The article (and the formalized model) suppose that the functioning of the economy is not disturbed by the operation of pathological factors mainly concer...

Superfluous neuroscience information makes explanations of psychological phenomena more appealing.

Science.gov (United States)

Fernandez-Duque, Diego; Evans, Jessica; Christian, Colton; Hodges, Sara D

2015-05-01

Does the presence of irrelevant neuroscience information make explanations of psychological phenomena more appealing? Do fMRI pictures further increase that allure? To help answer these questions, 385 college students in four experiments read brief descriptions of psychological phenomena, each one accompanied by an explanation of varying quality (good vs. circular) and followed by superfluous information of various types. Ancillary measures assessed participants' analytical thinking, beliefs on dualism and free will, and admiration for different sciences. In Experiment 1, superfluous neuroscience information increased the judged quality of the argument for both good and bad explanations, whereas accompanying fMRI pictures had no impact above and beyond the neuroscience text, suggesting a bias that is conceptual rather than pictorial. Superfluous neuroscience information was more alluring than social science information (Experiment 2) and more alluring than information from prestigious "hard sciences" (Experiments 3 and 4). Analytical thinking did not protect against the neuroscience bias, nor did a belief in dualism or free will. We conclude that the "allure of neuroscience" bias is conceptual, specific to neuroscience, and not easily accounted for by the prestige of the discipline. It may stem from the lay belief that the brain is the best explanans for mental phenomena.

A Bayesian explanation of the "Uncanny Valley" effect and related psychological phenomena

Science.gov (United States)

Moore, Roger K.

2012-11-01

There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the `uncanny valley' effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions.

Explanation and practice on ISO 9000

International Nuclear Information System (INIS)

Kwon, Dong Myeong

2001-01-01

This book reveals introduction on revision of ISO 9000:2000 with full account and contents of revision and change method change into ISO 9001:2000, the basic principle on ISO 9000:2000 and improvement and aim, definition on explanation, method for detail term, demand for ISO/KS A 9001:2000, quality management system development and transition way, standardization for quality management, manual of quality and making procedure and guide, case of quality manual and procedure and guide and ISO 9001:2000 / KS A 9001:2001 an English-Korean translation.

Theoretical vocabularies and styles of explanation of robot behaviours in children

Directory of Open Access Journals (Sweden)

Datteri Edoardo

2017-06-01

Full Text Available How do children describe and explain the behaviour of robotic systems? In this paper, some distinctions between different types of explanations, drawing from the philosophy of science literature, are proposed and exemplified by reference to an activity in which primary school children are asked to describe and explain the behaviour of a pre-programmed Braitenberg-like vehicle. The proposed distinctions are also discussed against other studies drawn from the related scientific literature. A qualitative study has provided insights to further refine the analysis described here, through the introduction of other sub-categories of explanation of robotic behaviours.

HIV in Japan: Epidemiologic puzzles and ethnographic explanations

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Anthony S. DiStefano

2016-12-01

Full Text Available Japan is widely perceived to have a low level of HIV occurrence; however, its HIV epidemics also have been the subject of considerable misunderstanding globally. I used a ground truthing conceptual framework to meet two aims: first, to determine how accurately official surveillance data represented Japan's two largest epidemics (urban Kansai and Tokyo as understood and experienced on the ground; and second, to identify explanations for why the HIV epidemics were unfolding as officially reported. I used primarily ethnographic methods while drawing upon epidemiology, and compared government surveillance data to observations at community and institutional sites (459 pages of field notes; 175 persons observed, qualitative interviews with stakeholders in local HIV epidemics (n = 32, and document research (n = 116. This revealed seven epidemiologic puzzles involving officially reported trends and conspicuously missing information. Ethnographically grounded explanations are presented for each. These included factors driving the epidemics, which ranged from waning government and public attention to HIV, to gaps in sex education and disruptive leadership changes in public institutions approximately every two years. Factors constraining the epidemics also contributed to explanations. These ranged from subsidized medical treatment for most people living with HIV, to strong partnerships between government and a well-developed, non-governmental sector of HIV interventionists, and protective norms and built environments in the sex industry. Local and regional HIV epidemics were experienced and understood as worse than government reports indicated, and ground-level data often contradicted official knowledge. Results thus call into question epidemiologic trends, including recent stabilization of the national epidemic, and suggest the need for revisions to the surveillance system and strategies that address factors driving and constraining the epidemics. Based

The Difficulties of Reductionistic Explanation of Moral Knowledge

Directory of Open Access Journals (Sweden)

SeyyedAli Asghari

2016-03-01

Full Text Available Moral reductionist believes that the reality of moral qualities are the same qualities which can be expressed with immoral words. Such an ontological view has an epistemological aspect which states our understanding of moral facts is either our understanding of immoral facts or our deductions of immoral understanding. From moral reductionists and especially the naturalists’ point of view, the ability to explain moral knowledge without resorting to some theories such as moral intuition is considered to be an important advantage and even a strong reason for their view. Therefore, the present paper is going to study the reductionistic explanations about moral knowledge and justifications of moral believes. We have come to the conclusion that among the explanations presented by the naturalists, analytic knowledge has the same problems which have discredited the theory of analytic reductionism. Also, deducing value from non-value is either facing the logical gap of is-must; or if there is a meaningful descriptive-valuable link, we can’t finally come to unconditional moral results.

Avoidance within a changing assessment paradigm for Mediterranean Hake stocks

Directory of Open Access Journals (Sweden)

S. RAGONESE

2009-06-01

Full Text Available The Mediterranean hake Merluccius merluccius L., 1758, is the emblem of the so-called Mediterranean demersal fisheries paradox, showing a persistent, although stable, status of growth overexploitation and an impressive gap between current and any biological reference point. Almost full avoidance capability of large size females to bottom trawls, higher overall growth rates than previously believed and higher natural mortality in juveniles than adult, were considered among the most plausible explanation factors of such persistence. In the present note, arguments are illustrated to raise some concern about avoidance and highlight the important role of the other factors in improving assessments and launching a short term recovery plan for Mediterranean Hake stocks which is more acceptable to fishermen.

ExplaNet: A Collaborative Learning Tool and Hybrid Recommender System for Student-Authored Explanations

Science.gov (United States)

Masters, Jessica; Madhyastha, Tara; Shakouri, Ali

2008-01-01

ExplaNet is a web-based, anonymous, asynchronous explanation-sharing network. Instructors post questions to the network and students submit explanatory answers. Students then view and rank the explanations submitted by their peers before optionally resubmitting a final and revised answer. Three classroom evaluations of ExplaNet showed that by…

Social selection is a powerful explanation for prosociality.

Science.gov (United States)

Nesse, Randolph M

2016-01-01

Cultural group selection helps explain human cooperation, but social selection offers a complementary, more powerful explanation. Just as sexual selection shapes extreme traits that increase matings, social selection shapes extreme traits that make individuals preferred social partners. Self-interested partner choices create strong and possibly runaway selection for prosocial traits, without requiring group selection, kin selection, or reciprocity.

Dynamical 3-Space: Alternative Explanation of the "Dark Matter Ring"

Directory of Open Access Journals (Sweden)

Cahill R. T.

2007-10-01

Full Text Available NASA has claimed the discovery of a “Ring of Dark Matter” in the galaxy cluster CL 0024 +17, see Jee M.J. et al. arXiv:0705.2171, based upon gravitational lensing data. Here we show that the lensing can be given an alternative explanation that does not involve “dark matter”. This explanation comes from the new dynamics of 3-space. This dynamics involves two constant G and alpha — the fine structure constant. This dynamics has explained the bore hole anomaly, spiral galaxy flat rotation speeds, the masses of black holes in spherical galaxies, gravitational light bending and lensing, all without invoking “dark matter”, and also the supernova redshift data without the need for “dark energy”.

Nursing Teaching Strategies by Encouraging Students’ Questioning, Argumentation and Explanation

Directory of Open Access Journals (Sweden)

Dayse Neri de Souza

2014-12-01

Full Text Available Nursing students need to develop competences in the field of explanation, argumentation and questioning as they are pivotal to foster a relationship with their patients and achieve a greater humanisation of care. The objective of this paper is to analyse the perception of 1st-year nursing students with regard to the humanisation of care provided to patients by encouraging them to discuss real-life episodes. The study is qualitative and content analysis used the students’ questions, explanations and argumentation as core discourses. Among other conclusions, results point towards the importance of promoting activities that encourage the different nursing students’ discourses and the ability to understand the humanisation and dehumanisation patterns arising from the real-life episodes used as case study.

An Explanation of the Missing Flux from Boyajian's Mysterious Star

Energy Technology Data Exchange (ETDEWEB)

Foukal, Peter [192 Willow Road, Nahant, MA 01908 (United States)

2017-06-10

A previously unremarkable star in the constellation Cygnus has, in the past year, become known as the most mysterious object in our Galaxy. Boyajian’s star exhibits puzzling episodes of sporadic, deep dimming discovered in photometry with the Kepler Mission. Proposed explanations have focused on its obscuration by colliding exoplanets, exocomets, and even intervention of alien intelligence. These hypotheses have considered only phenomena external to the star because the radiative flux missing in the dimmings was believed to exceed the star’s storage capacity. We point out that modeling of variations in solar luminosity indicates that convective stars can store the required fluxes. It also suggests explanations for (a) a reported time-profile asymmetry of the short, deep dimmings and (b) a slower, decadal scale dimming reported from archival and Kepler photometry. Our findings suggest a broader range of explanations of Boyajian’s star that may produce new insights into stellar magneto-convection.

Graphical explanation in an expert system for Space Station Freedom rack integration

Science.gov (United States)

Craig, F. G.; Cutts, D. E.; Fennel, T. R.; Purves, B.

1990-01-01

The rationale and methodology used to incorporate graphics into explanations provided by an expert system for Space Station Freedom rack integration is examined. The rack integration task is typical of a class of constraint satisfaction problems for large programs where expertise from several areas is required. Graphically oriented approaches are used to explain the conclusions made by the system, the knowledge base content, and even at more abstract levels the control strategies employed by the system. The implemented architecture combines hypermedia and inference engine capabilities. The advantages of this architecture include: closer integration of user interface, explanation system, and knowledge base; the ability to embed links to deeper knowledge underlying the compiled knowledge used in the knowledge base; and allowing for more direct control of explanation depth and duration by the user. The graphical techniques employed range from simple statis presentation of schematics to dynamic creation of a series of pictures presented motion picture style. User models control the type, amount, and order of information presented.

The Case for a Gaian Bottleneck: The Biology of Habitability.

Science.gov (United States)

Chopra, Aditya; Lineweaver, Charles H

2016-01-01

The prerequisites and ingredients for life seem to be abundantly available in the Universe. However, the Universe does not seem to be teeming with life. The most common explanation for this is a low probability for the emergence of life (an emergence bottleneck), notionally due to the intricacies of the molecular recipe. Here, we present an alternative Gaian bottleneck explanation: If life emerges on a planet, it only rarely evolves quickly enough to regulate greenhouse gases and albedo, thereby maintaining surface temperatures compatible with liquid water and habitability. Such a Gaian bottleneck suggests that (i) extinction is the cosmic default for most life that has ever emerged on the surfaces of wet rocky planets in the Universe and (ii) rocky planets need to be inhabited to remain habitable. In the Gaian bottleneck model, the maintenance of planetary habitability is a property more associated with an unusually rapid evolution of biological regulation of surface volatiles than with the luminosity and distance to the host star.

Interpreting Black-Box Classifiers Using Instance-Level Visual Explanations

Energy Technology Data Exchange (ETDEWEB)

Tamagnini, Paolo; Krause, Josua W.; Dasgupta, Aritra; Bertini, Enrico

2017-05-14

To realize the full potential of machine learning in diverse real- world domains, it is necessary for model predictions to be readily interpretable and actionable for the human in the loop. Analysts, who are the users but not the developers of machine learning models, often do not trust a model because of the lack of transparency in associating predictions with the underlying data space. To address this problem, we propose Rivelo, a visual analytic interface that enables analysts to understand the causes behind predictions of binary classifiers by interactively exploring a set of instance-level explanations. These explanations are model-agnostic, treating a model as a black box, and they help analysts in interactively probing the high-dimensional binary data space for detecting features relevant to predictions. We demonstrate the utility of the interface with a case study analyzing a random forest model on the sentiment of Yelp reviews about doctors.

Synergy and Students' Explanations: Exploring the Role of Generic and Content-Specific Scaffolds

Science.gov (United States)

Delen, Ibrahim; Krajcik, Joseph

2018-01-01

In this study, we explored how a teacher used a new mobile application that enables students to collect data inside and outside the classroom, and then use the data to create scientific explanations by using claim-evidence-reasoning framework. Previous technologies designed to support scientific explanations focused on how these programs improve…

Reaction of Elemol with Acetic acid –Perchloric acid: Characterization of a novel oxide and (+)-β-cyperone

Digital Repository Service at National Institute of Oceanography (India)

Wahidullah, S.; Govenkar, M.B.; Paknikar, S.K.

from elemol 1.(+)-b-cyperone (3), a known sesquiterpene, has also been identified as a minor product of the reaction. Plausible mechanistic explanation for the formation of elemoxide (2) and (+)-b-cyperone (3) presented....

Modes of risk explanation in telephone consultations between nurses and parents for a genetic condition

DEFF Research Database (Denmark)

Zayts, Olga; Sarangi, Srikant

2013-01-01

as warrants for advice-giving and providing reassurance. We then examine how the genetic nurses interactionally orient themselves to the parents’ existing knowledge regarding G6PD deficiency while delivering these risk explanations. The differences in explanation trajectories are linked to the presence...

Sixth Graders' Co-Construction of Explanations of a Disturbance in an Ecosystem: Exploring Relationships between Grouping, Reflective Scaffolding, and Evidence-Based Explanations

Science.gov (United States)

Kyza, Eleni A.; Constantinou, Costas P.; Spanoudis, George

2011-01-01

We report on a study investigating the relationship between cognitive ability grouping, reflective inquiry scaffolding, and students' collaborative explanations of an ecosystem disturbance which took place when a number of flamingo birds died in a salt lake because of nearby intensive human activities. Twenty-six pairs of students from two intact…

Synthetic constructs in/for the environment: managing the interplay between natural and engineered Biology.

Science.gov (United States)

Schmidt, Markus; de Lorenzo, Víctor

2012-07-16

The plausible release of deeply engineered or even entirely synthetic/artificial microorganisms raises the issue of their intentional (e.g. bioremediation) or accidental interaction with the Environment. Containment systems designed in the 1980s-1990s for limiting the spread of genetically engineered bacteria and their recombinant traits are still applicable to contemporary Synthetic Biology constructs. Yet, the ease of DNA synthesis and the uncertainty on how non-natural properties and strains could interplay with the existing biological word poses yet again the challenge of designing safe and efficacious firewalls to curtail possible interactions. Such barriers may include xeno-nucleic acids (XNAs) instead of DNA as information-bearing molecules, rewriting the genetic code to make it non-understandable by the existing gene expression machineries, and/or making growth dependent on xenobiotic chemicals. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

A “Pathology Explanation Clinic (PEC” for Patient-Centered Laboratory Medicine Test Results

Directory of Open Access Journals (Sweden)

Blake Gibson MD

2018-03-01

Full Text Available This concept paper addresses communication issues arising between physicians and their patients. To facilitate the communication of essential diagnostic pathology information to patients, and address their questions and concerns, we propose that “Pathology Explanation Clinics” be created. The Pathology Explanation Clinics would provide a channel for direct communications between pathologists and patients. Pathologists would receive special training as “Certified Pathologist Navigators” in preparation for this role. The goal of Pathology Explanation Clinics would be to help fill gaps in communication of information contained in laboratory reports to patients, further explain its relevance, and improve patient understanding of the meaning of such information and its impact on their health and health-care choices. Effort would be made to ensure that Certified Pathologist Navigators work within the overall coordination of care by the health-care team.

Theory of bending waves with applications to disk galaxies

International Nuclear Information System (INIS)

Mark, J.W.K.

1982-01-01

A theory of bending waves is surveyed which provides an explanation for the required amplification of the warp in the Milky Way. It also provides for self-generated warps in isolated external galaxies. The shape of observed warps and partly their existence in isolated galaxies are indicative of substantial spheroidal components. The theory also provides a plausible explanation for the bending of the inner disk (<2 kpc) of the Milky Way

Developmental vitamin D deficiency causes abnormal brain development.

Science.gov (United States)

Eyles, D W; Feron, F; Cui, X; Kesby, J P; Harms, L H; Ko, P; McGrath, J J; Burne, T H J

2009-12-01

There is now clear evidence that vitamin D is involved in brain development. Our group is interested in environmental factors that shape brain development and how this may be relevant to neuropsychiatric diseases including schizophrenia. The origins of schizophrenia are considered developmental. We hypothesised that developmental vitamin D (DVD) deficiency may be the plausible neurobiological explanation for several important epidemiological correlates of schizophrenia namely: (1) the excess winter/spring birth rate, (2) increased incidence of the disease in 2nd generation Afro-Caribbean migrants and (3) increased urban birth rate. Moreover we have published two pieces of direct epidemiological support for this hypothesis in patients. In order to establish the "Biological Plausibility" of this hypothesis we have developed an animal model to study the effect of DVD deficiency on brain development. We do this by removing vitamin D from the diet of female rats prior to breeding. At birth we return all dams to a vitamin D containing diet. Using this procedure we impose a transient, gestational vitamin D deficiency, while maintaining normal calcium levels throughout. The brains of offspring from DVD-deficient dams are characterised by (1) a mild distortion in brain shape, (2) increased lateral ventricle volumes, (3) reduced differentiation and (4) diminished expression of neurotrophic factors. As adults, the alterations in ventricular volume persist and alterations in brain gene and protein expression emerge. Adult DVD-deficient rats also display behavioural sensitivity to agents that induce psychosis (the NMDA antagonist MK-801) and have impairments in attentional processing. In this review we summarise the literature addressing the function of vitamin D on neuronal and non-neuronal cells as well as in vivo results from DVD-deficient animals. Our conclusions from these data are that vitamin D is a plausible biological risk factor for neuropsychiatric disorders and that

On the plausibility of socioeconomic mortality estimates derived from linked data: a demographic approach.

Science.gov (United States)

Lerch, Mathias; Spoerri, Adrian; Jasilionis, Domantas; Viciana Fernandèz, Francisco

2017-07-14

Reliable estimates of mortality according to socioeconomic status play a crucial role in informing the policy debate about social inequality, social cohesion, and exclusion as well as about the reform of pension systems. Linked mortality data have become a gold standard for monitoring socioeconomic differentials in survival. Several approaches have been proposed to assess the quality of the linkage, in order to avoid the misclassification of deaths according to socioeconomic status. However, the plausibility of mortality estimates has never been scrutinized from a demographic perspective, and the potential problems with the quality of the data on the at-risk populations have been overlooked. Using indirect demographic estimation (i.e., the synthetic extinct generation method), we analyze the plausibility of old-age mortality estimates according to educational attainment in four European data contexts with different quality issues: deterministic and probabilistic linkage of deaths, as well as differences in the methodology of the collection of educational data. We evaluate whether the at-risk population according to educational attainment is misclassified and/or misestimated, correct these biases, and estimate the education-specific linkage rates of deaths. The results confirm a good linkage of death records within different educational strata, even when probabilistic matching is used. The main biases in mortality estimates concern the classification and estimation of the person-years of exposure according to educational attainment. Changes in the census questions about educational attainment led to inconsistent information over time, which misclassified the at-risk population. Sample censuses also misestimated the at-risk populations according to educational attainment. The synthetic extinct generation method can be recommended for quality assessments of linked data because it is capable not only of quantifying linkage precision, but also of tracking problems in

Nitrogenous Derivatives of Phosphorus and the Origins of Life: Plausible Prebiotic Phosphorylating Agents in Water

Directory of Open Access Journals (Sweden)

Megha Karki

2017-07-01

Full Text Available Phosphorylation under plausible prebiotic conditions continues to be one of the defining issues for the role of phosphorus in the origins of life processes. In this review, we cover the reactions of alternative forms of phosphate, specifically the nitrogenous versions of phosphate (and other forms of reduced phosphorus species from a prebiotic, synthetic organic and biochemistry perspective. The ease with which such amidophosphates or phosphoramidate derivatives phosphorylate a wide variety of substrates suggests that alternative forms of phosphate could have played a role in overcoming the “phosphorylation in water problem”. We submit that serious consideration should be given to the search for primordial sources of nitrogenous versions of phosphate and other versions of phosphorus.

Information performances and illative sequences: Sequential organization of explanations of chemical phase equilibrium

Science.gov (United States)

Brown, Nathaniel James Swanton

While there is consensus that conceptual change is surprisingly difficult, many competing theories of conceptual change co-exist in the literature. This dissertation argues that this discord is partly the result of an inadequate account of the unwritten rules of human social interaction that underlie the field's preferred methodology---semi-structured interviewing. To better understand the contributions of interaction during explanations, I analyze eight undergraduate general chemistry students as they attempt to explain to various people, for various reasons, why phenomena involving chemical phase equilibrium occur. Using the methods of interaction analysis, I characterize the unwritten, but systematic, rules that these participants follow as they explain. The result is a description of the contributions of interaction to explaining. Each step in each explanation is a jointly performed expression of a subject-predicate relation, an interactive accomplishment I call an information performance (in-form, for short). Unlike clauses, in-forms need not have a coherent grammatical structure. Unlike speaker turns, in-forms have the clear function of expressing information. Unlike both clauses and speaker turns, in-forms are a co-construction, jointly performed by both the primary speaker and the other interlocutor. The other interlocutor strongly affects the form and content of each explanation by giving or withholding feedback at the end of each in-form, moments I call feedback-relevant places. While in-forms are the bricks out of which the explanation is constructed, they are secured by a series of inferential links I call an illative sequence. Illative sequences are forward-searching, starting with a remembered fact or observation and following a chain of inferences in the hope it leads to the target phenomenon. The participants treat an explanation as a success if the illative sequence generates an in-form that describes the phenomenon. If the illative sequence does

The Quality of Explanations for Deviation from Principles of Corporate Governance. An Introduction

Directory of Open Access Journals (Sweden)

Izabela Koładkiewicz

2017-11-01

Full Text Available Purpose: The purpose of this paper is to summarize studies aiming to define matters related to the quality of explanations found in corporate governance statements published by listed companies. Another important aspect of the conducted analysis is the identification of various dimensions of explanation quality. Methodology: The character of the conducted research is that of an overview of literature devoted to the subject. Apart from scientific articles, it covers European Union regulations, regulations characteristic of countries selected for the analysis (member states of the European Union, and applied solutions aimed at guaranteeing the desired quality of explanations for deviation included in corporate governance statements that are in the centre of attention. Findings: The conducted analysis organizes the current knowledge concerning actions aimed at improving the quality of explanations for deviation from principles of corporate governance. Without a doubt, the primary pillar consists of the level of information and its quality, as found in explanations for shareholders. It is this quality that determines if the shareholder understands the processes occurring in the realm of corporate governance in the company. Research limitations: The conducted analysis should be treated as an introduction to related research issues. It should be stressed that research into explanations provided by companies is still in the process of development, and the number of publications devoted to this topic is still modest. Practical implications: The study fits in the research into the phenomena of the “comply or explain” mechanism as applied in practice, which according of many researchers, continues to be poorly investigated. In terms of the directions for further research, there are promising topics including e.g. identification of factors that may translate into the quality of such statements (e.g. ownership structure, identity of shareholders, the

Coleridge: a computer tool for assisting musical reflection and self-explanation

Directory of Open Access Journals (Sweden)

John Cook

1998-12-01

Full Text Available Since the mid-1980s, there has been a movement away from knowledge supplied by the teacher and towards talking, reflecting and explaining as ways to learn. An example of this change in focus is provided by the self-explanation work of Chi et al (1994 who describe an approach to talking science rather than hearing science. According to Chi and coworkers, generating explanations to oneself (self-explanations facilitates the integration of new information into existing knowledge. Reflecting about one's own learning is the same as thinking about learning or metacognition. Metacognition can be defined as the understanding of knowledge, an understanding that can be reflected in either effective use or overt description of the knowledge in question (Brown, 1987. This definition of metacognition requires of a learner both internalized thinking about learning (that is, reflection, and externalized communication, through language or action, that indicates an understanding of knowledge (that is, a self-explanation. In the work described in this paper the overall pedagogical goal is to encourage creative reflection in learners. Creative reflection is defined as the ability of a learner to imagine musical opportunities in novel situations, and then to make accurate predictions (verbally about these opportunities. To succeed at creative reflection there should be a correspondence between what a learner predicts will happen and what actually happens. An example would be a learner first writing a musical phrase using musical notation, then predicting verbally how that phrase will sound, playing the phrase back on a piano, and finally evaluating if the prediction was accurate or not. Very little work has been done on how computers can be used to support talking, reflecting and explaining in the creative subject-area of musical composition. The rest of this paper addresses this issue.

Developing Explanations and Developing Understanding: Students Explain the Phases of the Moon Using Visual Representations

Science.gov (United States)

Parnafes, Orit

2012-01-01

This article presents a theoretical model of the process by which students construct and elaborate explanations of scientific phenomena using visual representations. The model describes progress in the underlying conceptual processes in students' explanations as a reorganization of fine-grained knowledge elements based on the Knowledge in Pieces…

A Reconfigurable and Biologically Inspired Paradigm for Computation Using Network-On-Chip and Spiking Neural Networks

Directory of Open Access Journals (Sweden)

Jim Harkin

2009-01-01

Full Text Available FPGA devices have emerged as a popular platform for the rapid prototyping of biological Spiking Neural Networks (SNNs applications, offering the key requirement of reconfigurability. However, FPGAs do not efficiently realise the biologically plausible neuron and synaptic models of SNNs, and current FPGA routing structures cannot accommodate the high levels of interneuron connectivity inherent in complex SNNs. This paper highlights and discusses the current challenges of implementing scalable SNNs on reconfigurable FPGAs. The paper proposes a novel field programmable neural network architecture (EMBRACE, incorporating low-power analogue spiking neurons, interconnected using a Network-on-Chip architecture. Results on the evaluation of the EMBRACE architecture using the XOR benchmark problem are presented, and the performance of the architecture is discussed. The paper also discusses the adaptability of the EMBRACE architecture in supporting fault tolerant computing.

Box-and-arrow explanations need not be more abstract than neuroscientific mechanism descriptions.

Science.gov (United States)

Datteri, Edoardo; Laudisa, Federico

2014-01-01

The nature of the relationship between box-and-arrow (BA) explanations and neuroscientific mechanism descriptions (NMDs) is a key foundational issue for cognitive science. In this article we attempt to identify the nature of the constraints imposed by BA explanations on the formulation of NMDs. On the basis of a case study about motor control, we argue that BA explanations and NMDs both identify regularities that hold in the system, and that these regularities place constraints on the formulation of NMDs from BA analyses, and vice versa. The regularities identified in the two kinds of explanation play a crucial role in reasoning about the relationship between them, and in justifying the use of neuroscientific experimental techniques for the empirical testing of BA analyses of behavior. In addition, we make claims concerning the similarities and differences between BA analyses and NMDs. First, we argue that both types of explanation describe mechanisms. Second, we propose that they differ in terms of the theoretical vocabulary used to denote the entities and properties involved in the mechanism and engaging in regular, mutual interactions. On the contrary, the notion of abstractness, defined as omission of detail, does not help to distinguish BA analyses from NMDs: there is a sense in which BA analyses are more detailed than NMDs. In relation to this, we also focus on the nature of the extra detail included in NMDs and missing from BA analyses, arguing that such detail does not always concern how the system works. Finally, we propose reasons for doubting that BA analyses, unlike NMDs, may be considered "mechanism sketches." We have developed these views by critically analyzing recent claims in the philosophical literature regarding the foundations of cognitive science.

Box-and-arrow explanations need not be more abstract than neuroscientific mechanism descriptions

Directory of Open Access Journals (Sweden)

Edoardo eDatteri

2014-05-01

Full Text Available The nature of the relationship between box-and-arrow (BA explanations and neuroscientific mechanism descriptions (NMDs is a key foundational issue for cognitive science. In this article we attempt to identify the nature of the constraints imposed by BA explanations on the formulation of NMDs. On the basis of a case study about motor control, we argue that BA explanations and NMDs both identify regularities that hold in the system, and that these regularities place constraints on the formulation of NMDs from BA analyses, and vice versa. The regularities identified in the two kinds of explanation play a crucial role in reasoning about the relationship between them, and in justifying the use of neuroscientific experimental techniques for the empirical testing of BA analyses of behavior. In addition, we make claims concerning the similarities and differences between BA analyses and NMDs. First, we argue that both types of explanation describe mechanisms. Second, we propose that they differ in terms of the theoretical vocabulary used to denote the entities and properties involved in the mechanism and engaging in regular, mutual interactions. On the contrary, the notion of abstractness, defined as omission of detail, does not help to distinguish BA analyses from NMDs: there is a sense in which BA analyses are more detailed than NMDs. In relation to this, we also focus on the nature of the extra detail included in NMDs and missing from BA analyses, arguing that such detail does not always concern how the system works. Finally, we propose reasons for doubting that BA analyses, unlike NMDs, may be considered mechanism sketches. We have developed these views by critically analyzing recent claims in the philosophical literature regarding the foundations of cognitive science.

The philosophy of modelling or does the philosophy of biology have any use?

Science.gov (United States)

Orzack, Steven Hecht

2012-01-19

Biologists in search of answers to real-world issues such as the ecological consequences of global warming, the design of species' conservation plans, understanding landscape dynamics and understanding gene expression make decisions constantly that are based on a 'philosophical' stance as to how to create and test explanations of an observed phenomenon. For better or for worse, some kind of philosophy is an integral part of the doing of biology. Given this, it is more important than ever to undertake a practical assessment of what philosophy does mean and should mean to biologists. Here, I address three questions: should biologists pay any attention to 'philosophy'; should biologists pay any attention to 'philosophy of biology'; and should biologists pay any attention to the philosophy of biology literature on modelling? I describe why the last question is easily answered affirmatively, with the proviso that the practical benefits to be gained by biologists from this literature will be directly proportional to the extent to which biologists understand 'philosophy' to be a part of biology, not apart from biology.

Education's impact on explanations of radical right-wing voting

NARCIS (Netherlands)

Lubbers, M.; Tolsma, J.

2011-01-01

One of the reactions to the large demographic changes in Europe due to migration has been the rise of radical right-wing parties. Previous research has shown that education is one of the most relevant explanations of this voting behaviour. By pooling the European Social Surveys from 2002, 2004, 2006

Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in Brassica rapa Fast Plants

Science.gov (United States)

Smith, Amber R.; Williams, Paul H.; McGee, Seth A.; Dósa, Katalin; Pfammatter, Jesse

2014-01-01

Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics. PMID:25185225

Experiences and Explanations of ADHD

DEFF Research Database (Denmark)

Nielsen, Mikka

Research on Attention Deficit Hyperactivity Disorder (ADHD) usually presents the disorder from either a neurobiological perspective, describing the disorder as an impairment in executive functions, or from a critical, sociological perspective, whereby ADHD is explained as a consequence...... of the medicalization of deviant behaviour. Neither of these perspectives tells us about the experience of living with ADHD, or explains how ADHD unfolds within specific contexts and relations. Experiences and Explanations of ADHD addresses this lacuna by exploring bodily experiences of ADHD and people’s experiences...... of obtaining a diagnosis. Drawing on in-depth interviews with adults diagnosed with ADHD, the book provides an examination of how the diagnosis is understood, used and acted upon by the people receiving the diagnosis. This book delves into the phenomenology of ADHD and uncovers the experiences of a highly...

Darwin's Difficulties and Students' Struggles with Trait Loss: Cognitive-Historical Parallelisms in Evolutionary Explanation

Science.gov (United States)

Ha, Minsu; Nehm, Ross H.

2014-05-01

Although historical changes in scientific ideas sometimes display striking similarities with students' conceptual progressions, some scholars have cautioned that such similarities lack meaningful commonalities. In the history of evolution, while Darwin and his contemporaries often used natural selection to explain evolutionary trait gain or increase, they struggled to use it to convincingly account for cases of trait loss or decrease. This study examines Darwin's evolutionary writings about trait gain and loss in the Origin of Species (On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. D. Appleton, New York, 1859) and compares them to written evolutionary explanations for trait gain and loss in a large (n > 500), cross-cultural and cross-sectional sample (novices and experts from the USA and Korea). Findings indicate that significantly more students and experts applied natural selection to cases of trait gain, but like Darwin and his contemporaries, they more often applied `use and disuse' and `inheritance of acquired characteristics' to episodes of trait loss. Although the parallelism between Darwin's difficulties and students' struggles with trait loss are striking, significant differences also characterize explanatory model structure. Overall, however, students and scientists struggles to explain trait loss—which is a very common phenomenon in the history of life—appear to transcend time, place, and level of biological expertise. The significance of these findings for evolution education are discussed; in particular, the situated nature of biological reasoning, and the important role that the history of science can play in understanding cognitive constraints on science learning.

A skin-picking disorder case report: a psychopathological explanation

Directory of Open Access Journals (Sweden)

Ângela Ribeiro

2015-06-01

Full Text Available We describe the case of a 44-year-old woman, without known previous psychiatric history, hospitalized after a significant hemorrhage caused by self-inflicted deep facial dermal lesions (with muscle exposition. Psychopathological possible explanations of this case, as in similar reviewed ones, are related to frustration, aggression, and impulsivity.

A Self-Categorization Explanation for the Third-Person Effect

Science.gov (United States)

Reid, Scott A.; Hogg, Michael A.

2005-01-01

Three studies tested a self-categorization theory explanation for the third-person effect. In Study 1 (N = 49) undergraduate students judged the influence of the "National Enquirer," "Wall Street Journal," and TV show "Friends" on themselves, relative to low- and high-status outgroup members, and other undergraduate students. The profile of first-…

Bifurcations of a class of singular biological economic models

International Nuclear Information System (INIS)

Zhang Xue; Zhang Qingling; Zhang Yue

2009-01-01

This paper studies systematically a prey-predator singular biological economic model with time delay. It shows that this model exhibits two bifurcation phenomena when the economic profit is zero. One is transcritical bifurcation which changes the stability of the system, and the other is singular induced bifurcation which indicates that zero economic profit brings impulse, i.e., rapid expansion of the population in biological explanation. On the other hand, if the economic profit is positive, at a critical value of bifurcation parameter, the system undergoes a Hopf bifurcation, i.e., the increase of delay destabilizes the system and bifurcates into small amplitude periodic solution. Finally, by using Matlab software, numerical simulations illustrate the effectiveness of the results obtained here. In addition, we study numerically that the system undergoes a saddle-node bifurcation when the bifurcation parameter goes through critical value of positive economic profit.

Generation of brake squeal. Fundamental vibration in brake system; Entstehungsmechanismus des Bremsenquietschens. Grundschwingung im Bremssystem

Energy Technology Data Exchange (ETDEWEB)

Shi Xiaoming; Mitschke, M.

1997-11-01

Reducing or preventing brake squealing is a prime goal of brake development. To provide constructional means of doing this the mechanism by which it occurs must first be understood. Research at the Technical University of Braunschweig now offers a plausible explanation. (orig.) [Deutsch] Die Verringerung oder Vermeidung des Bremsenquietschens ist ein wichtiges Ziel der Bremsenentwicklung. Um konstruktiv Abhilfe zu schaffen, muss zunaechst der Entstehungsmechanismus fuer dieses unerwuenschte Geraeusch geklaert werden. Forschung an der Technischen Universitaet Braunschweig ermoeglicht jetzt eine plausible Erklaerung. (orig.)

Effect of sub-pore scale morphology of biological deposits on porous media flow properties

Science.gov (United States)

Ghezzehei, T. A.

2012-12-01

Biological deposits often influence fluid flow by altering the pore space morphology and related hydrologic properties such as porosity, water retention characteristics, and permeability. In most coupled-processes models changes in porosity are inferred from biological process models using mass-balance. The corresponding evolution of permeability is estimated using (semi-) empirical porosity-permeability functions such as the Kozeny-Carman equation or power-law functions. These equations typically do not account for the heterogeneous spatial distribution and morphological irregularities of the deposits. As a result, predictions of permeability evolution are generally unsatisfactory. In this presentation, we demonstrate the significance of pore-scale deposit distribution on porosity-permeability relations using high resolution simulations of fluid flow through a single pore interspersed with deposits of varying morphologies. Based on these simulations, we present a modification to the Kozeny-Carman model that accounts for the shape of the deposits. Limited comparison with published experimental data suggests the plausibility of the proposed conceptual model.

Explanations of Freud's Psychoanalysis Theories on the Lives and ...

African Journals Online (AJOL)

This paper examines some of the various explanations of Freud's theories on a selected number of Western Artist and their works. It highlights the impact of his findings on the authenticity of the concept as regards, dreams, the Oedipus complex and imagery. Its objective is to prove that a number of Western European artist ...

Explaining the emergence of social trust

DEFF Research Database (Denmark)

Svendsen, Gunnar Lind Haase; Tinggaard Svendsen, Gert; Graeff, Peter

2012-01-01

How does social trust emerge in a country? By comparing the cases of Denmark and Germany through six historical phases, we suggest that a plausible explanation is long run political stability. In Denmark, social trust was arguably allowed to accumulate slowly over time and was probably not destro......How does social trust emerge in a country? By comparing the cases of Denmark and Germany through six historical phases, we suggest that a plausible explanation is long run political stability. In Denmark, social trust was arguably allowed to accumulate slowly over time and was probably...... not destroyed up till the universal welfare state of the 20th century. In Germany, however, political instability since the first German state building hampered the emergence and maintenance of social trust, which is why social trust was never allowed to grow in this country....

Signature of Plausible Accreting Supermassive Black Holes in Mrk 261/262 and Mrk 266

Directory of Open Access Journals (Sweden)

Gagik Ter-Kazarian

2013-01-01

Full Text Available We address the neutrino radiation of plausible accreting supermassive black holes closely linking to the 5 nuclear components of galaxy samples of Mrk 261/262 and Mrk 266. We predict a time delay before neutrino emission of the same scale as the age of the Universe. The ultrahigh energy neutrinos are produced in superdense protomatter medium via simple (quark or pionic reactions or modified URCA processes (G. Gamow was inspired to name the process URCA after the name of a casino in Rio de Janeiro. The resulting neutrino fluxes for quark reactions are ranging from to , where is the opening parameter. For pionic and modified URCA reactions, the fluxes are and , respectively. These fluxes are highly beamed along the plane of accretion disk, peaked at ultrahigh energies, and collimated in smaller opening angle .

An explanation of the Hiroshima activation dilemma

International Nuclear Information System (INIS)

Rhoades, W.A.; Barnes, J.M.; Santoro, R.T.

1994-01-01

A 1987 study of the radiation from the World War II nuclear weapons applied state-of-the-art data and computer techniques, providing an important advance in reliability of the results. Still, a disturbing disagreement remained between slow-neutron activation measurements and calculations for the Hiroshima event. Newer data have confirmed the validity of the discrepancy. This work examines various potential explanations. Of those examined, only an enhancement to the weapon neutron leakage spectrum in the vicinity of the 2.3 MeV oxygen cross section window can fit the data accurately

Assessment and comparison of culturally based explanations for mental disorder among Singaporean Chinese youth.

Science.gov (United States)

Mathews, Mathew

2011-01-01

Culture is important to how populations understand the cause of mental disorder, a variable that has implications for treatment-seeking behaviour. Asian populations underutilize professional mental health treatment partly because of their endorsement of supernatural causation models to explain mental disorders, beliefs that stem from their religious backgrounds. This study sought to understand the dimensions of explanatory models used by three groups of Singaporean Chinese youth (n = 842)--Christian, Chinese religionist, no religion--and examined their responses to an instrument that combined explanations from psychological and organic perspectives on mental disorder with approaches from Asian and Western religious traditions. Factor analysis revealed five factors. Two were psychological corresponding to the humanistic and cognitive-behavioural perspectives respectively. Another two, which were supernatural in nature, dealt with karmaic beliefs popular among Asian religionists and more classical religious explanations common in monotheistic religions. The remaining factor was deemed a physiological model although it incorporated an item that made it consistent with an Asian organic model. While groups differed in their endorsement of supernatural explanations, psychological perspectives had the strongest endorsement among this population. Regression analysis showed that individuals who endorsed supernatural explanations more strongly tended to have no exposure to psychology courses and heightened religiosity.

African Heath Sciences Vol 7 No 4.p65

African Journals Online (AJOL)

FOMCS2

urinary tract bacterial infections detected in urine samples at a hospital in ... be the result of anatomic abnormalities, but there is no plausible explanation in others2. ... preparation of fresh-centrifuged urine was made from each urine specimen ...

Using novel descriptor accounting for ligand-receptor interactions to define and visually explore biologically relevant chemical space.

Science.gov (United States)

Rabal, Obdulia; Oyarzabal, Julen

2012-05-25

The definition and pragmatic implementation of biologically relevant chemical space is critical in addressing navigation strategies in the overlapping regions where chemistry and therapeutically relevant targets reside and, therefore, also key to performing an efficient drug discovery project. Here, we describe the development and implementation of a simple and robust method for representing biologically relevant chemical space as a general reference according to current knowledge, independently of any reference space, and analyzing chemical structures accordingly. Underlying our method is the generation of a novel descriptor (LiRIf) that converts structural information into a one-dimensional string accounting for the plausible ligand-receptor interactions as well as for topological information. Capitalizing on ligand-receptor interactions as a descriptor enables the clustering, profiling, and comparison of libraries of compounds from a chemical biology and medicinal chemistry perspective. In addition, as a case study, R-groups analysis is performed to identify the most populated ligand-receptor interactions according to different target families (GPCR, kinases, etc.), as well as to evaluate the coverage of biologically relevant chemical space by structures annotated in different databases (ChEMBL, Glida, etc.).

Why Sketching May Aid Learning From Science Texts: Contrasting Sketching With Written Explanations.

Science.gov (United States)

Scheiter, Katharina; Schleinschok, Katrin; Ainsworth, Shaaron

2017-10-01

The goal of this study was to explore two accounts for why sketching during learning from text is helpful: (1) sketching acts like other constructive strategies such as self-explanation because it helps learners to identify relevant information and generate inferences; or (2) that in addition to these general effects, sketching has more specific benefits due to the pictorial representation that is constructed. Seventy-three seventh-graders (32 girls, M = 12.82 years) were first taught how to either create sketches or self-explain while studying science texts. During a subsequent learning phase, all students were asked to read an expository text about the greenhouse effect. Finally, they were asked to write down everything they remembered and then answer transfer questions. Strategy quality during learning was assessed as the number of key concepts that had either been sketched or mentioned in the self-explanations. The results showed that at an overall performance level there were only marginal group differences. However, a more in-depth analysis revealed that whereas no group differences emerged for students implementing either strategy poorly, the sketching group clearly outperformed the self-explanation group for students who applied the strategies with higher quality. Furthermore, higher sketching quality was strongly related to better learning outcomes. Thus, the study's results are more in line with the second account: Sketching can have a beneficial effect on learning above and beyond generating written explanations; at least, if well deployed. Copyright © 2017 Cognitive Science Society, Inc.

Indexing and Exploiting a Discourse History to Generate Context-Sensitive Explanations

National Research Council Canada - National Science Library

Moore, Johanna D

1993-01-01

... to their own previous explanations. Based on a study of human-human instructional inter- actions, we are categorizing the uses of previous discourse and are developing a computational model of this behavior...

Tutorial dialogues and gist explanations of genetic breast cancer risk.

Science.gov (United States)

Widmer, Colin L; Wolfe, Christopher R; Reyna, Valerie F; Cedillos-Whynott, Elizabeth M; Brust-Renck, Priscila G; Weil, Audrey M

2015-09-01

The intelligent tutoring system (ITS) BRCA Gist is a Web-based tutor developed using the Shareable Knowledge Objects (SKO) platform that uses latent semantic analysis to engage women in natural-language dialogues to teach about breast cancer risk. BRCA Gist appears to be the first ITS designed to assist patients' health decision making. Two studies provide fine-grained analyses of the verbal interactions between BRCA Gist and women responding to five questions pertaining to breast cancer and genetic risk. We examined how "gist explanations" generated by participants during natural-language dialogues related to outcomes. Using reliable rubrics, scripts of the participants' verbal interactions with BRCA Gist were rated for content and for the appropriateness of the tutor's responses. Human researchers' scores for the content covered by the participants were strongly correlated with the coverage scores generated by BRCA Gist, indicating that BRCA Gist accurately assesses the extent to which people respond appropriately. In Study 1, participants' performance during the dialogues was consistently associated with learning outcomes about breast cancer risk. Study 2 was a field study with a more diverse population. Participants with an undergraduate degree or less education who were randomly assigned to BRCA Gist scored higher on tests of knowledge than those assigned to the National Cancer Institute website or than a control group. We replicated findings that the more expected content that participants included in their gist explanations, the better they performed on outcome measures. As fuzzy-trace theory suggests, encouraging people to develop and elaborate upon gist explanations appears to improve learning, comprehension, and decision making.

Children balance theories and evidence in exploration, explanation, and learning

NARCIS (Netherlands)

Bonawitz, E.B.; van Schijndel, T.J.P.; Friel, D.; Schulz, L.

2012-01-01

We look at the effect of evidence and prior beliefs on exploration, explanation and learning. In Experiment 1, we tested children both with and without differential prior beliefs about balance relationships (Center Theorists, mean: 82 months; Mass Theorists, mean: 89 months; No Theory children,

The Importance of Qualitative Research for Causal Explanation in Education

Science.gov (United States)

Maxwell, Joseph A.

2012-01-01

The concept of causation has long been controversial in qualitative research, and many qualitative researchers have rejected causal explanation as incompatible with an interpretivist or constructivist approach. This rejection conflates causation with the positivist "theory" of causation, and ignores an alternative understanding of causation,…

Social class, psychosocial factors and disease : from deception towards explanation.

NARCIS (Netherlands)

Ranchor, Adelita Vijaynti

1994-01-01

This thesis deals with the question of the extent to which socioeconomic status (sas) is related to disease. The main focus is the explanation of this relation, applying a muitifactor approach aimed at the integration of socioeconomic, psychosocial factors and health-related behavior. ... Zie:

Generalizing the order and the parameters of macro-operators by explanation-based learning - Extension of Explanation-Based Learning on Partial Order

International Nuclear Information System (INIS)

Li, Huihua

1992-01-01

The traditional generalization methods such as FIKE's macro-operator learning and Explanation-Based Learning (EBL) deal with totally ordered plans. They generalize only the plan operators and the conditions under which the generalized plan can be applied in its initial total order, but not the partial order among operators in which the generalized plan can be successfully executed. In this paper, we extend the notion of the EBL on the partial order of plans. A new method is presented for learning, from a totally or partially ordered plan, partially ordered macro-operators (generalized plans) each of which requires a set of the weakest conditions for its reuse. It is also valuable for generalizing partially ordered plans. The operators are generalized in the FIKE's triangle table. We introduce the domain axioms to generate the constraints for the consistency of generalized states. After completing the triangle table with the information concerning the operator destructions (interactions), we obtain the global explanation of the partial order on the operators. Then, we represent all the necessary ordering relations by a directed graph. The exploitation of this graph permits to explicate the dependence between the partial orders and the constraints among the parameters of generalized operators, and allows all the solutions to be obtained. (author) [fr

Critical thinking skills profile of senior high school students in Biology learning

Science.gov (United States)

Saputri, A. C.; Sajidan; Rinanto, Y.

2018-04-01

Critical thinking is an important and necessary skill to confront the challenges of the 21st century. Critical thinking skills accommodate activities that can improve high-order thinking skills. This study aims to determine senior high school students' critical thinking skills in Biology learning. This research is descriptive research using instruments developed based on the core aspects of critical thinking skills according to Facione which include interpretation, analysis, evaluation, explanation, conclusion, and self-regulation. The subjects in this study were 297 students in grade 12 of a senior high school in Surakarta selected through purposive sampling technique. The results of this study showed that the students' critical thinking skills on evaluation and self-regulation are in good criterion with 78% and 66% acquisition while 52% interpretation, 56% analysis, 52% conclusion and 42% explanation indicate sufficient criteria. The conclusion from this research is that critical thinking skill of the students still was in enough category, so that needed a way to enhance it on some indicators.

Animation, audio, and spatial ability: Optimizing multimedia for scientific explanations

Science.gov (United States)

Koroghlanian, Carol May

This study investigated the effects of audio, animation and spatial ability in a computer based instructional program for biology. The program presented instructional material via text or audio with lean text and included eight instructional sequences presented either via static illustrations or animations. High school students enrolled in a biology course were blocked by spatial ability and randomly assigned to one of four treatments (Text-Static Illustration Audio-Static Illustration, Text-Animation, Audio-Animation). The study examined the effects of instructional mode (Text vs. Audio), illustration mode (Static Illustration vs. Animation) and spatial ability (Low vs. High) on practice and posttest achievement, attitude and time. Results for practice achievement indicated that high spatial ability participants achieved more than low spatial ability participants. Similar results for posttest achievement and spatial ability were not found. Participants in the Static Illustration treatments achieved the same as participants in the Animation treatments on both the practice and posttest. Likewise, participants in the Text treatments achieved the same as participants in the Audio treatments on both the practice and posttest. In terms of attitude, participants responded favorably to the computer based instructional program. They found the program interesting, felt the static illustrations or animations made the explanations easier to understand and concentrated on learning the material. Furthermore, participants in the Animation treatments felt the information was easier to understand than participants in the Static Illustration treatments. However, no difference for any attitude item was found for participants in the Text as compared to those in the Audio treatments. Significant differences were found by Spatial Ability for three attitude items concerning concentration and interest. In all three items, the low spatial ability participants responded more positively

Azimuthal instabilities of the Gribov-Levin-Ryskin equation

Energy Technology Data Exchange (ETDEWEB)

Gambini, Guillermo; Torrieri, Giorgio [State University of Campinas, IFGW, Campinas (Brazil)

2017-01-15

We introduce the phenomenology of elliptic flow in nuclear collisions, and argue that its scaling across energies, rapidities and system sizes could be suggestive of a QCD-based rather than a hydrodynamical explanation. As a hypothesis for such an explanation, we show that the GLR equation develops unstable modes when the parton distribution function is generalized to depend on azimuthal angle. This generally means that the structure function acquires an azimuthal dependence. We argue that this process is a plausible alternative explanation for the origin of elliptic flow, one that naturally respects the scaling experimentally observed. (orig.)

A case of collision tumor or transdifferentiation between malignant melanoma and leiomyosarcoma

DEFF Research Database (Denmark)

Ul-Mulk, Jamshaid; Rasmussen, Helle; Breiting, Line

2012-01-01

with a seborrheic keratosis. There have also been occasional reports of rhabdomyosarcomatous differentiation. However, mesenchymal differentiation, and in this case leiomysarcoma, with formation of heterologous elements in melanocytic tumor is very rare. Another plausible explanation may be that malignant melanoma...

46 CFR Appendix II to Part 150 - Explanation of Figure 1

Science.gov (United States)

2010-10-01

... COMPATIBILITY OF CARGOES Pt. 150, App. II Appendix II to Part 150—Explanation of Figure 1 Definition of a..., aromatic hydrocarbons or paraffins. Others will form hazardous combinations with many groups: For example...

A Physicist's Quest in Biology: Max Delbrück and "Complementarity".

Science.gov (United States)

Strauss, Bernard S

2017-06-01

Max Delbrück was trained as a physicist but made his major contribution in biology and ultimately shared a Nobel Prize in Physiology or Medicine. He was the acknowledged leader of the founders of molecular biology, yet he failed to achieve his key scientific goals. His ultimate scientific aim was to find evidence for physical laws unique to biology: so-called "complementarity." He never did. The specific problem he initially wanted to solve was the nature of biological replication but the discovery of the mechanism of replication was made by others, in large part because of his disdain for the details of biochemistry. His later career was spent investigating the effect of light on the fungus Phycomyces , a topic that turned out to be of limited general interest. He was known both for his informality but also for his legendary displays of devastating criticism. His life and that of some of his closest colleagues was acted out against a background of a world in conflict. This essay describes the man and his career and searches for an explanation of his profound influence. Copyright © 2017 by the Genetics Society of America.

Natural Selection in Cancer Biology: From Molecular Snowflakes to Trait Hallmarks

Science.gov (United States)

Fortunato, Angelo; Boddy, Amy; Mallo, Diego; Aktipis, Athena; Maley, Carlo C.; Pepper, John W.

2017-01-01

Evolution by natural selection is the conceptual foundation for nearly every branch of biology and increasingly also for biomedicine and medical research. In cancer biology, evolution explains how populations of cells in tumors change over time. It is a fundamental question whether this evolutionary process is driven primarily by natural selection and adaptation or by other evolutionary processes such as founder effects and drift. In cancer biology, as in organismal evolutionary biology, there is controversy about this question and also about the use of adaptation through natural selection as a guiding framework for research. In this review, we discuss the differences and similarities between evolution among somatic cells versus evolution among organisms. We review what is known about the parameters and rate of evolution in neoplasms, as well as evidence for adaptation. We conclude that adaptation is a useful framework that accurately explains the defining characteristics of cancer. Further, convergent evolution through natural selection provides the only satisfying explanation both for how a group of diverse pathologies have enough in common to usefully share the descriptive label of “cancer” and for why this convergent condition becomes life-threatening. PMID:28148564

Natural Selection in Cancer Biology: From Molecular Snowflakes to Trait Hallmarks.

Science.gov (United States)

Fortunato, Angelo; Boddy, Amy; Mallo, Diego; Aktipis, Athena; Maley, Carlo C; Pepper, John W

2017-02-01

Evolution by natural selection is the conceptual foundation for nearly every branch of biology and increasingly also for biomedicine and medical research. In cancer biology, evolution explains how populations of cells in tumors change over time. It is a fundamental question whether this evolutionary process is driven primarily by natural selection and adaptation or by other evolutionary processes such as founder effects and drift. In cancer biology, as in organismal evolutionary biology, there is controversy about this question and also about the use of adaptation through natural selection as a guiding framework for research. In this review, we discuss the differences and similarities between evolution among somatic cells versus evolution among organisms. We review what is known about the parameters and rate of evolution in neoplasms, as well as evidence for adaptation. We conclude that adaptation is a useful framework that accurately explains the defining characteristics of cancer. Further, convergent evolution through natural selection provides the only satisfying explanation both for how a group of diverse pathologies have enough in common to usefully share the descriptive label of "cancer" and for why this convergent condition becomes life-threatening. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Typology in pollination biology: Lessons from an historical critique

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Andreas Erhardt

2011-03-01

Full Text Available Typological schemes that describe putative floral adaptations for pollinators have played a central role in pollination biology. In 1882 the prominent German botanist and Darwinist Hermann Müller commented critically on a precursor of modern versions of such “pollination syndromes” that had been developed by his Italian colleague Federico Delpino. Delpino also was a self-proclaimed Darwinist, but in fact adhered to teleology—explanation beyond nature. As a consequence he viewed his typology as reflecting a deeper ideal and thus as rigidly true, and rejected as unimportant any visitors to flowers that it did not predict. Although Müller also classified flowers as to pollinators, he considered such schemes to be fallible, and pondered what diversity and variation in floral visitors might mean. Müller’s comments, which we translate here, are of interest given that appeals to teleology have resurfaced from time to time in discussions of pollination syndromes, and more importantly because his warning against taking typological schemes too literally remains valid. Typology is a useful tool in biology, including pollination biology, but care must be taken that it does not replace nature as perceived reality.

Investigating the origins of political views: biases in explanation predict conservative attitudes in children and adults.

Science.gov (United States)

Hussak, Larisa J; Cimpian, Andrei

2018-05-01

We tested the hypothesis that political attitudes are influenced by an information-processing factor - namely, a bias in the content of everyday explanations. Because many societal phenomena are enormously complex, people's understanding of them often relies on heuristic shortcuts. For instance, when generating explanations for such phenomena (e.g., why does this group have low status?), people often rely on facts that they can retrieve easily from memory - facts that are skewed toward inherent or intrinsic features (e.g., this group is unintelligent). We hypothesized that this bias in the content of heuristic explanations leads to a tendency to (1) view socioeconomic stratification as acceptable and (2) prefer current societal arrangements to alternative ones, two hallmarks of conservative ideology. Moreover, since the inherence bias in explanation is present across development, we expected it to shape children's proto-political judgments as well. Three studies with adults and 4- to 8-year-old children (N = 784) provided support for these predictions: Not only did individual differences in reliance on inherent explanations uniquely predict endorsement of conservative views (particularly the stratification-supporting component; Study 1), but manipulations of this explanatory bias also had downstream consequences for political attitudes in both children and adults (Studies 2 and 3). This work contributes to our understanding of the origins of political attitudes. © 2017 John Wiley & Sons Ltd.

A network-level explanation for the differences in HIV prevalence in ...

African Journals Online (AJOL)

A network-level explanation for the differences in HIV prevalence in South Africa's ... or ethnic groups may help explain the differential spread of HIV in South Africa. ... Keywords: concurrency, epidemiology, ethnicity, HIV/AIDS, race, social ...

Cannabis and psychosis: an update on course and biological plausible mechanisms

NARCIS (Netherlands)

Linszen, Don; van Amelsvoort, Therese

2007-01-01

PURPOSE OF REVIEW: Cannabis use is the most commonly abused illicit substance. Its relation with psychosis remains a topic of debate. Epidemiological studies suggest that cannabis is a component cause accounting for approximately 10% of cases. An increasing number of studies have been published on

Detection of Low-order Curves in Images using Biologically-plausible Hardware

Science.gov (United States)

2012-09-29

the intersections of iso-eccentricity and iso-polar contours were entered into the computer via a graphics tablet . In regions where there was...functional mri . Cerebral Cortex, 7:181 – 192, 1997. [25] Jacob Feldman. Bayesian contour integration. Perception and Psychophysics, 63:1171 – 1182, 2001. [26

The Different Effects of Family on Objective Career Success across Gender: A Test of Alternative Explanations

Science.gov (United States)

Kirchmeyer, Catherine

2006-01-01

Gender gaps in achieved rank and salary, common indicators of objective success, often are attributed to the different family roles and responsibilities of men and women. This study tested three explanations for the different effects of family on careers: that is, choice, performance, and signaling explanations. In a sample of American doctoral…

Designing Automated Guidance to Promote Productive Revision of Science Explanations

Science.gov (United States)

Tansomboon, Charissa; Gerard, Libby F.; Vitale, Jonathan M.; Linn, Marcia C.

2017-01-01

Supporting students to revise their written explanations in science can help students to integrate disparate ideas and develop a coherent, generative account of complex scientific topics. Using natural language processing to analyze student written work, we compare forms of automated guidance designed to motivate productive revision and help…

A hadronic explanation of the lepton anomaly

DEFF Research Database (Denmark)

Mertsch, Philipp; Sarkar, Subir

2014-01-01

The rise in the positron fraction, observed by PAMELA, Fermi-LAT and most recently by AMS-02, has created a lot of interest, fuelled by speculations about an origin in dark matter annihilation in the Galactic halo. However, other channels, e.g. antiprotons or gamma-rays, now severely constrain dark....... This mechanism is guaranteed if hadronic CRs are present and would also lead to observable signatures in other secondary channels like the boron-to-carbon or antiproton-to-proton ratios. If such features were borne out by upcoming AMS-02 data, this would rule out other explanations....

Flip-Floppers and Wafflers: Explanations and Repositioning

DEFF Research Database (Denmark)

Robison, Joshua

to this literature by showing that repositioning’s influence on evaluations depends on beliefs citizens make concerning why the policy switch occurred, beliefs that are, in turn, structured by the communication environment surrounding such switches. Specifically, I use two large national survey experiments to show...... that repositioning elites who provide a satisfactory explanation for their change in position escape evaluative harm from their actions and that this occurs even among individuals who lost proximity from the elite’s change in position and among those from a different party as the elite. This study thus has important...

A Critique of the Meta-theoretical Explanations and Analyses of the ...

African Journals Online (AJOL)

conditions for the Stimulation and Attraction of Foreign Direct Investments. ... these explanations and analyses are able to sufficiently account for, and capture the critical forces, processes and factors that tend to shape the movement of capital globally.

A Critical Analysis of the Established Explanations about the Nature of Ecotourism

Directory of Open Access Journals (Sweden)

Nazmiye Erdoğan

2012-12-01

Full Text Available This qualitative study questions the prevailing explanations about the nature of ecotourism. The major aims of the study are (a to point out that the widespread notions and theoretical attributions about the character of ecotourism should be reconsidered and (b to express the need for critical questioning and design in qualitative and quantitative academic studies in social, management, administrative and tourism sciences. The article explains, first, the basic rationale for legitimizing, market building, supporting, sustaining and expanding the capitalist market, including ecotourism practices, and connects the concept of environment with economy, and inclusion of tourism and ecotourism in sustainable development. Then, it discusses the nature of dominant explanations of ecotourism. The study concludes that widespread explanations of the nature, structure, activity and outcome of ecotourism rarely match the nature of daily ecotourism practices. Instead, they generally create, employ and sustain functional myths about industrial practices, relations, causes, effects and outcomes of ecotourism. They provide strategically prescriptive and normative ethics and principles that are mostly unattainable. They consciously or inadvertently ignore the fact that the notion of ecotourism is deeply embedded in the logics of ideological normalisation of corporate activities, commodity circulation, technological end-product distribution and use, and global governance of the economic, political and cultural market conditions.

On the electrodynamic explanation of the retrograde motion of the electric arc

International Nuclear Information System (INIS)

Hong, J.S.; Allen, J.E.

1992-01-01

The retrograde motion of the cathode spot in a transverse magnetic field is one of the more intriguing phenomena of the electric arc. Although the phenomenon has been known for nearly ninety years since its discovery by Stark and has stimulated numerous investigations which result in many models giving explanation from different points of view, there is still no theory that can account both qualitatively and quantitatively for all the observations. Most of the explanations of the retrograde motion involve the study of cathode processes to give the preferential formation of new cathode spots along the retrograde direction. One line of explanation, which is rather different from the others, is based on electrodynamics. In this approach the retrograde motion is treated as an electrodynamic event. The present paper develops the theory suggested by Robson and von Engel. A more complete model is proposed and studied in detail by means of electromagnetic field theory. The results obtained not only show that the retrograde motion can be explained by the electrodynamics, but also confirm that the average current density on the cathode spot must be around the order of 10 12 A/m 2 . Recent studies of spot current density have shown values of this order. (author) 22 refs., 4 figs., 1 tab

Misconceptions about optics: An effect of misleading explanations?

Science.gov (United States)

Favale, Fabrizio; Bondani, Maria

2014-07-01

During our activities of physics dissemination with High School students especially concerning optics, we are used to distribute a questionnaire about colors and image formation by mirrors and lenses. The answers to some questions clearly show misconceptions and naïve ideas about colors, ray tracing, image formation in reflection and refraction. These misconceptions are widespread and do not depend on the gender, the level, and the age of the students: they seem to depend on some wrong ideas and explanatory models that are not changed by the curricular studies at school. In fact, the same errors are present in groups of students before and after taking optics courses at High School. On the other hand we have also found some misleading explanations of the phenomena both in textbooks and websites. Most of the time, errors occur in the explanatory drawings accompanying the text, which are based on some hybrid description of the optical processes: sometimes the description of the path of the ray light is confused with the image reconstruction by the lenses. We think that to partially avoid some errors it is important to use a teaching path centered on the actual path of the rays and not on what eyes see (the vision). Here we present the results of data collected from more than 200 students and some considerations about figures and explanations found in textbooks.

An explanation of the mysterious quasars

International Nuclear Information System (INIS)

Borissov, O.

1977-01-01

The article presents details of a convincing new theory submitted by Russian scientists, concerning the physical nature of quasars. These were discovered in 1963 and for over ten years no satisfactory theory has been forthcoming to explain their seemingly incompatible properties or the associated phenomena. These very distant objects are believed to be sources of the most powerful electromagnetic emission. From the new theory expounded it is concluded that for the first time since their discovery a satisfactory explanation of their nature has been reached. From this it is hoped that the mechanism of energy generation by quasars may ultimately be understood and, though on a much reduced scale, contribute to the solution of energy problems on earth. (R.J.J.)

Biological implications of the Viking mission to Mars

International Nuclear Information System (INIS)

Mazur, P.; Barghoorn, E.S.; Jukes, T.H.; Margulis, L.

1978-01-01

A central purpose of Viking was to search for evidence that life exists on Mars or may have existed in the past. The missions carried three biology experiments the prime purpose of which was to seek for existing microbial life. They produced clear evidence of chemical reactivity in soil samples, but it is becoming increasingly clear that the chemical reactions were nonbiological in origin. The unexpected release of oxygen by soil moistened with water vapor in the Gas Exchange experiment together with the negative findings of the organic analysis experiment lead to the conclusion that the surface contains powerful oxidants. This conclusion is consistent with models of the atmosphere. The oxidants appear also to have been responsible for the decarboxylation of the organic nutrients that were introduced in the Label Release experiment. The major results of the GEX and LR experiments have been simulated at least qualitatively on Earth. The third, Pyrolytic Release, experiment obtained evidence for organic synthesis by soil samples. Although the mechanism of the synthesis is obscure, the thermal stability of the reaction makes a biological explanation most unlikely. Furthermore, the response of soil samples in all three experiments to the addition of water is not consistent with a biological interpretation. (Auth.)

Biological implications of the Viking mission to Mars

Energy Technology Data Exchange (ETDEWEB)

Mazur, P [Oak Ridge National Lab., TN (USA); Barghoorn, E S [Harvard Univ., Cambridge, MA (USA). Dept. of Biology; Halvorson, H O [Brandeis Univ., Waltham, MA (USA); Jukes, T H [California Univ., Berkeley (USA). Space Sciences Lab.; Kaplan, I R [California Univ., Los Angeles (USA); Margulis, L [Boston Univ., MA (USA)

1978-06-01

A central purpose of Viking was to search for evidence that life exists on Mars or may have existed in the past. The missions carried three biology experiments the prime purpose of which was to seek for existing microbial life. They produced clear evidence of chemical reactivity in soil samples, but it is becoming increasingly clear that the chemical reactions were nonbiological in origin. The unexpected release of oxygen by soil moistened with water vapor in the Gas Exchange experiment together with the negative findings of the organic analysis experiment lead to the conclusion that the surface contains powerful oxidants. This conclusion is consistent with models of the atmosphere. The oxidants appear also to have been responsible for the decarboxylation of the organic nutrients that were introduced in the Label Release experiment. The major results of the GEX and LR experiments have been simulated at least qualitatively on Earth. The third, Pyrolytic Release, experiment obtained evidence for organic synthesis by soil samples. Although the mechanism of the synthesis is obscure, the thermal stability of the reaction makes a biological explanation most unlikely. Furthermore, the response of soil samples in all three experiments to the addition of water is not consistent with a biological interpretation.

Supporting cognition in systems biology analysis: findings on users' processes and design implications.

Science.gov (United States)

Mirel, Barbara

2009-02-13

Current usability studies of bioinformatics tools suggest that tools for exploratory analysis support some tasks related to finding relationships of interest but not the deep causal insights necessary for formulating plausible and credible hypotheses. To better understand design requirements for gaining these causal insights in systems biology analyses a longitudinal field study of 15 biomedical researchers was conducted. Researchers interacted with the same protein-protein interaction tools to discover possible disease mechanisms for further experimentation. Findings reveal patterns in scientists' exploratory and explanatory analysis and reveal that tools positively supported a number of well-structured query and analysis tasks. But for several of scientists' more complex, higher order ways of knowing and reasoning the tools did not offer adequate support. Results show that for a better fit with scientists' cognition for exploratory analysis systems biology tools need to better match scientists' processes for validating, for making a transition from classification to model-based reasoning, and for engaging in causal mental modelling. As the next great frontier in bioinformatics usability, tool designs for exploratory systems biology analysis need to move beyond the successes already achieved in supporting formulaic query and analysis tasks and now reduce current mismatches with several of scientists' higher order analytical practices. The implications of results for tool designs are discussed.

Evaluation of the Teaching Methods Used in Secondary School Biology Lessons

Directory of Open Access Journals (Sweden)

Porozovs Juris

2015-06-01

Full Text Available The teacher’s skills in conducting the lesson and choice of teaching methods play an essential role in creating students’ interest in biology. The aim of the research was to study the opinion of secondary school students and biology teachers regarding the most successful teaching methods used in biology lessons and viable options to make biology lessons more interesting. The research comprised polling students and biology teachers from several schools, namely: 2 secondary schools in Jelgava, 2 in Riga and 1 in Vecumnieki. The responses revealed that 58% of students find biology lessons interesting. 56% of students indicated that their ability to focus attention during biology lessons depends on the task presented to them. Most of all they prefer watching the teacher’s presentations, listening to their teacher telling about the actual topic as well as performing laboratory work and group-work. Many students like participating in discussions, whereas a far smaller number would do various exercises, individual tasks, fill out worksheets or complete projects. Least of all students wish to work with the textbook. The methods most frequently applied by teachers are as follows: lecture, explanation, demonstration, and discussion. Teachers believe that their students prefer laboratory work and discussions as well as listening to their teacher and watching presentations or films. They also indicate at the necessity to link theory with practice and to involve information technologies. While teaching their subject biology teachers try to establish relationship between theory and real life in order to develop their students’ interest in natural processes.

China's meat and grain imports during 2000–2012 and beyond

DEFF Research Database (Denmark)

Yu, Wusheng; Cao, Lijuan

2015-01-01

projected shifts in consumption patterns driven by rapid per capita income growth. Several plausible explanations of this paradoxical trade pattern are offered, including mass imports of feed grains, persistent (but shrinking) gaps between Chinese and international meat prices, tariff barriers, and non-tariff...

Improving innovation strategic decision-making through the collaboration with design consultancies

NARCIS (Netherlands)

Calabretta, G.; Gemser, G.; Wijnberg, N.; Hekkert, P.P.M.

2012-01-01

Innovation and design literature have given limited consideration to the strategic role of design consultancies in the innovation processes of their clients. A plausible explanation is the difficulty to assess the quality of design consultancies’ output, given the intangibility of the output itself

Cognitive ability and self-control in relation to dietary habits, physical activity and bodyweight in adolescents

NARCIS (Netherlands)

Junger, Marianne; van Kampen, Margit

2010-01-01

Background Previous studies showed that cognitive ability is related to health and mortality. The cause of this relationship remains largely unknown. One plausible explanation is that cognitive ability is related to behaviours that affect health. This study investigates whether cognitive ability is

Older persons' definitions and explanations of elder abuse in the Netherlands

DEFF Research Database (Denmark)

Mysyuk, Yuliya; Westendorp, Rudi G J; Lindenberg, Jolanda

2016-01-01

persons in society, which result in disrespect toward older persons and a lack of social control and responsibility. The older persons' explanations for the occurrence of abuse mainly focus on societal changes; older persons seem to regard elder abuse primarily as a societal problem. This understanding of......In this article we explore older persons' definitions of and explanations for elder abuse in the Netherlands by means of interviews with older persons. A qualitative study was conducted based on semi-structured interviews with 35 older persons who had no experience with abuse. Our findings show...... that older persons participating in our study define elder abuse foremost as physical violence that is performed intentionally. The study participants explain elder abuse as a result of the dependency and vulnerability of older persons, of changing norms and values, and of changes in the position of older...

Atomistic explanation of brittle failure of thermoelectric skutterudite CoSb3

International Nuclear Information System (INIS)

Li, Guodong; An, Qi; Goddard, William A.; Hanus, Riley; Zhai, Pengcheng; Zhang, Qingjie; Snyder, G. Jeffrey

2016-01-01

CoSb 3 based skutterudite thermoelectric material has superior thermoelectric properties, but the low fracture toughness prevents its widespread commercial application. To determine the origin of its brittle failure, we examined the response of shear deformation in CoSb 3 along the most plausible slip system (010)/<100>, using large-scale molecular dynamics simulations. We find that the brittle failure of CoSb 3 arises from the formation of shear bands due to the destruction of Sb4-rings and the slippage of Co-octahedraes. This leads to the breakage of Co-octahedraes and cavitation, resulting in the crack opening and mechanical failure.

Phthalates impact human health: Epidemiological evidences and plausible mechanism of action.

Science.gov (United States)

Benjamin, Sailas; Masai, Eiji; Kamimura, Naofumi; Takahashi, Kenji; Anderson, Robin C; Faisal, Panichikkal Abdul

2017-10-15

Disregarding the rising alarm on the hazardous nature of various phthalates and their metabolites, ruthless usage of phthalates as plasticizer in plastics and as additives in innumerable consumer products continues due low their cost, attractive properties, and lack of suitable alternatives. Globally, in silico computational, in vitro mechanistic, in vivo preclinical and limited clinical or epidemiological human studies showed that over a dozen phthalates and their metabolites ingested passively by man from the general environment, foods, drinks, breathing air, and routine household products cause various dysfunctions. Thus, this review addresses the health hazards posed by phthalates on children and adolescents, epigenetic modulation, reproductive toxicity in women and men; insulin resistance and type II diabetes; overweight and obesity, skeletal anomalies, allergy and asthma, cancer, etc., coupled with the description of major phthalates and their general uses, phthalate exposure routes, biomonitoring and risk assessment, special account on endocrine disruption; and finally, a plausible molecular cross-talk with a unique mechanism of action. This clinically focused comprehensive review on the hazards of phthalates would benefit the general population, academia, scientists, clinicians, environmentalists, and law or policy makers to decide upon whether usage of phthalates to be continued swiftly without sufficient deceleration or regulated by law or to be phased out from earth forever. Copyright © 2017. Published by Elsevier B.V.

Biological Correlates of Empathy

Directory of Open Access Journals (Sweden)

E. Timucin Oral

2010-04-01

Full Text Available Empathy can be defined as the capacity to know emotionally what another is experiencing from within the frame of reference of that other person and the capacity to sample the feelings of another or it can be metaphorized as to put oneself in another’s shoes. Although the concept of empathy was firstly described in psychological theories, researches studying the biological correlates of psychological theories have been increasing recently. Not suprisingly, dinamically oriented psychotherapists Freud, Kohut, Basch and Fenichel had suggested theories about the biological correlates of empathy concept and established the basis of this modality decades ago. Some other theorists emphasized the importance of empathy in the early years of lifetime regarding mother-child attachment in terms of developmental psychology and investigated its role in explanation of psychopathology. The data coming from some of the recent brain imaging and animal model studies also seem to support these theories. Although increased activity in different brain regions was shown in many of the brain imaging studies, the role of cingulate cortex for understanding mother-child relationship was constantly emphasized in nearly all of the studies. In addition to these studies, a group of Italian scientists has defined a group of neurons as “mirror neurons” in their studies observing rhesus macaque monkeys. Later, they also defined mirror neurons in human studies, and suggested them as “empathy neurons”. After the discovery of mirror neurons, the hopes of finding the missing part of the puzzle for understanding the biological correlates of empathy raised again. Although the roles of different biological parameters such as skin conductance and pupil diameter for defining empathy have not been certain yet, they are going to give us the opportunity to revise the inconsistent basis of structural validity in psychiatry and to stabilize descriptive validity. In this review, the

The rebirth of the morphogenetic field as an explanatory tool in biology

Directory of Open Access Journals (Sweden)

Perović Slobodan

2013-01-01

Full Text Available I discuss two uses of the concept of the morphogenetic field, a tool of the 19th century biology motivated by particular ontological views of the time, which has been re-emerging and increasingly relevant in explaining microbiological phenomena. I also consider the relation of these uses to the Central Dogma of modern biology as well as Modern Synthesis of Darwinism and genetics. An induced morphogenetic field is determined by a physical (e.g., gravitational field, or it acquires a physical (e.g., visco-elastic field’s characteristics. Such a morphogenetic field presents only a weak challenge to the Central Dogma of Modern Synthesis by indirectly, albeit severely, constraining variability at the molecular level. I discuss explanations that introduce structural inheritance in ciliate protozoa, as well as the experimental evidence on which these arguments are based. The global cellular morphogenetic field is a unit of such inheritance. I discuss relevant cases of structural inheritance in ciliates that bring about internal cellular as well as functional changes and point out that DNA is absent in the cortex and that RNA controls neither intermediary nor the global level of the field. I go on to argue that utilizing knowledge of known physical fields may advance explanations and understanding of the morphogenetic field in ciliates as the unit of both development and inheritance. [Projekat Ministarstva nauke Republike Srbije, br. 179041: Dynamic Systems in nature and society: Philosophical and empirical aspects

Children Balance Theories and Evidence in Exploration, Explanation, and Learning

Science.gov (United States)

Bonawitz, Elizabeth Baraff; van Schijndel, Tessa J. P.; Friel, Daniel; Schulz, Laura

2012-01-01

We look at the effect of evidence and prior beliefs on exploration, explanation and learning. In Experiment 1, we tested children both with and without differential prior beliefs about balance relationships (Center Theorists, mean: 82 months; Mass Theorists, mean: 89 months; No Theory children, mean: 62 months). Center and Mass Theory children who…

Mindfulness and Cardiovascular Disease Risk: State of the Evidence, Plausible Mechanisms, and Theoretical Framework

Science.gov (United States)

Schuman-Olivier, Zev; Britton, Willoughby B.; Fresco, David M.; Desbordes, Gaelle; Brewer, Judson A.; Fulwiler, Carl

2016-01-01

The purpose of this review is to provide (1) a synopsis on relations of mindfulness with cardiovascular disease (CVD) and major CVD risk factors, and (2) an initial consensus-based overview of mechanisms and theoretical framework by which mindfulness might influence CVD. Initial evidence, often of limited methodological quality, suggests possible impacts of mindfulness on CVD risk factors including physical activity, smoking, diet, obesity, blood pressure, and diabetes regulation. Plausible mechanisms include (1) improved attention control (e.g., ability to hold attention on experiences related to CVD risk, such as smoking, diet, physical activity, and medication adherence), (2) emotion regulation (e.g., improved stress response, self-efficacy, and skills to manage craving for cigarettes, palatable foods, and sedentary activities), and (3) self-awareness (e.g., self-referential processing and awareness of physical sensations due to CVD risk factors). Understanding mechanisms and theoretical framework should improve etiologic knowledge, providing customized mindfulness intervention targets that could enable greater mindfulness intervention efficacy. PMID:26482755

Reciprocity-based reasons for benefiting research participants: most fail, the most plausible is problematic.

Science.gov (United States)

Sofaer, Neema

2014-11-01

A common reason for giving research participants post-trial access (PTA) to the trial intervention appeals to reciprocity, the principle, stated most generally, that if one person benefits a second, the second should reciprocate: benefit the first in return. Many authors consider it obvious that reciprocity supports PTA. Yet their reciprocity principles differ, with many authors apparently unaware of alternative versions. This article is the first to gather the range of reciprocity principles. It finds that: (1) most are false. (2) The most plausible principle, which is also problematic, applies only when participants experience significant net risks or burdens. (3) Seldom does reciprocity support PTA for participants or give researchers stronger reason to benefit participants than equally needy non-participants. (4) Reciprocity fails to explain the common view that it is bad when participants in a successful trial have benefited from the trial intervention but lack PTA to it. © 2013 John Wiley & Sons Ltd.

Style investing: behavioral explanations of stock market anomalies

OpenAIRE

Wouters, T.

2006-01-01

Abstract PhD-project The aim of this thesis is to explore the mechanisms of style investing. My project consists of two parts, each with an individual goal: 1. The first objective will be to analyze the implications of the dynamics of value and growth strategies for the US stock market. 2. The second objective will be to find explanations for stock returns by introducing the effects of collective preferences of investors into the dynamics of stock markets. We introduce style popularity as an ...

Empirical Phenomenon, Subjective Construction And Ontological Trught: (An Analysis of Problems of Scientific Explanation and Critical Realism Approach

Directory of Open Access Journals (Sweden)

Faramarz Taghilou

2014-12-01

Full Text Available Both the positivist and negativist frameworks of explanation are common in this naturalist proposition that unlike the metaphysical philosophy, reality is embedded only in experimental level. Therefore, the scientific explanation of natural and social phenomenon should refer to this experimental level in order to be called meaningful, verifiable and scientific. But, the problem was always that the principle of causality as a necessary condition for every kind of scientific explanation is not logically deductible from induction in experimental level and remains as a metaphysical principle. The principle of experimental objectivity as a condition for the verifiability clause of scientific explanations could not be defended, because the experimentation was always embedded in subjectivity and theory. The Kantian idealists, in contrast, considering the scientific explanation as a mere representation of reality in subjective categories, could not justify the experimental knowledge of reality and the rationality for comparison among theories and paradigms. Critical Realism as an important approach in philosophy of science that relates to the works and thoughts of Roy Bhaskar tries to solve these problems by resorting to its principles of ontological realism, epistemological relativism, and judgmental rationality. Considering and analyzing the scientific explanation’s issues, we have focused here on the answers of the Critical Realism in this case. We will argue that how the Critical Realist interpretation of scientific explanation, the experimental phenomenon, and the subjective construction and ontological reality all reach to a logical coherence with each other.

Explanation and observability of diffraction in time

International Nuclear Information System (INIS)

Torrontegui, E.; Muga, J. G.; Munoz, J.; Ban, Yue

2011-01-01

Diffraction in time (DIT) is a fundamental phenomenon in quantum dynamics due to time-dependent obstacles and slits. It is formally analogous to diffraction of light, and is expected to play an increasing role in the design of coherent matter wave sources, as in the atom laser, to analyze time-of-flight information and emission from ultrafast pulsed excitations, and in applications of coherent matter waves in integrated atom-optical circuits. We demonstrate that DIT emerges robustly in quantum waves emitted by an exponentially decaying source and provide a simple explanation of the phenomenon, as an interference of two characteristic velocities. This allows for its controllability and optimization.

A critique of the ontology of consumer enchantment

DEFF Research Database (Denmark)

Østergaard, Per; Fitchett, James; Jantzen, Christian

2013-01-01

The concept of enchantment offers a plausible explanation of the lures and thrills of consumer culture. We examine the theoretical foundation of the concept through a critique of Ritzer's enchantment thesis. We begin by assessing the enchantment/disenchantment discourse through a review of the main...

Corrosion in a STP Sump. (Subtitle: What Causes It and What Can Be Done About It?)

Science.gov (United States)

State regulators have noticed extensive corrosion in the sumps for the submersible turbine pump (STP) of an underground storage tanks storing gasoline and E85. Acetic acid produced by biodegradation of ethanol that found its way into the sump is one plausible explanation. Resea...

Exposures to airborne particulate matter and adverse perinatal outcomes: a biologically plausible mechanistic framework for exploring potential Exposição à matéria particulada aérea e efeitos perinatais adversos: referencial mecanístico biologicamente plausível para exploração de potenciais

Directory of Open Access Journals (Sweden)

Srimathi Kannan

2007-12-01

Full Text Available This article has three objectives: to describe the biologically plausible mechanistic pathways by which exposure to particulate matter (PM may lead to adverse perinatal outcomes of low birth weight (LBW, intrauterine growth retardation (IUGR, and preterm delivery (PTD; review evidence showing that nutrition affects biologic pathways; and explain mechanisms by which nutrition may modify the impact of PM exposure on perinatal outcomes. We propose an interdisciplinary framework that brings together maternal and infant nutrition, air pollution exposure assessment, and cardiopulmonary and perinatal epidemiology. Five possible biologic mechanisms have been put forth in the emerging environmental sciences literature and provide corollaries for the proposed framework. The literature indicates that the effects of PM on LBW, PTD, and IUGR may manifest through the cardiovascular mechanisms of oxidative stress, inflammation, coagulation, endothelial function, and hemodynamic responses. PM exposure studies relating mechanistic pathways to perinatal outcomes should consider the likelihood that biologic responses and adverse birth outcomes may be derived from both PM and non-PM sources. We present strategies for empirically testing the proposed model and developing future research efforts.São três os objetivos deste artigo: descrever rotas mecanísticas biologicamente plausíveis pelas quais a exposição à matéria particulada (MP pode levar a efeitos perinatais adversos, como baixo peso ao nascer (BPN, retardo do crescimento intra-uterino (RCIU e nascimentos pré-termo (NPT; fazer uma revisão de evidências mostrando que a nutrição afeta rotas biológicas; explicar os mecanismos através dos quais a nutrição pode modificar o impacto da exposição a MP nos efeitos perinatais adversos. Propomos um referencial interdisciplinar que aproxime nutrição materna e infantil, avaliação de poluição do ar e epidemiologia cardiopulmonar e perinatal

Non-specific effects of vaccines: plausible and potentially important, but implications uncertain.

Science.gov (United States)

Pollard, Andrew J; Finn, Adam; Curtis, Nigel

2017-11-01

Non-specific effects (NSE) or heterologous effects of vaccines are proposed to explain observations in some studies that certain vaccines have an impact beyond the direct protection against infection with the specific pathogen for which the vaccines were designed. The importance and implications of such effects remain controversial. There are several known immunological mechanisms which could lead to NSE, since it is widely recognised that the generation of specific immunity is initiated by non-specific innate immune mechanisms that may also have wider effects on adaptive immune function. However, there are no published studies that demonstrate a mechanistic link between such immunological phenomena and clinically relevant NSE in humans. While it is highly plausible that some vaccines do have NSE, their magnitude and duration, and thus importance, remain uncertain. Although the WHO recently concluded that current evidence does not justify changes to immunisation policy, further studies of sufficient size and quality are needed to assess the importance of NSE for all-cause mortality. This could provide insights into vaccine immunobiology with important implications for infant health and survival. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

An Explanation of Nakamoto's Analysis of Double-spend Attacks

OpenAIRE

Ozisik, A. Pinar; Levine, Brian Neil

2017-01-01

The fundamental attack against blockchain systems is the double-spend attack. In this tutorial, we provide a very detailed explanation of just one section of Satoshi Nakamoto's original paper where the attack's probability of success is stated. We show the derivation of the mathematics relied upon by Nakamoto to create a model of the attack. We also validate the model with a Monte Carlo simulation, and we determine which model component is not perfect.

How people explain their own and others’ behavior: A theory of lay causal explanations

Directory of Open Access Journals (Sweden)

Gisela eBöhm

2015-02-01

Full Text Available A theoretical model is proposed that speci¬fies lay causal theo¬ries of behavior; and supporting experimental evidence is presented. The model’s basic assumption is that diffe¬rent types of behavior trigger different hypotheses concerning the types of causes that may have brought about the behavior. Se¬ven categories are distinguished that are assumed to serve as both behavior types and explanation types: goals, disposi¬tions, tem¬po¬rary states such as emotions, intentional actions, outcomes, events, and sti¬mulus attributes. The mo¬del specifies inference rules that lay people use when explai¬ning beha¬vior (actions are caused by goals; goals are caused by higher order goals or temporary states; temporary states are caused by dispositions, stimulus attributes, or events; outcomes are caused by actions, temporary states, dispositions, stimulus attributes, or events; events are caused by dispositions or preceding events. Two experiments are reported. Experi¬ment 1 showed that free-response explanations followed the assumed inference rules. Expe¬ri¬ment 2 demonstrated that ex¬plana¬tions which match the inference rules are generated faster and more frequently than non-matching explanations. Together, the findings support models that incorporate knowledge-based aspects into the process of causal explanation. The results are discussed with respect to their implications for different stages of this process, such as the activation of causal hypotheses and their subsequent selection, as well as with respect to social influences on this process.

Causal learning is collaborative: Examining explanation and exploration in social contexts.

Science.gov (United States)

Legare, Cristine H; Sobel, David M; Callanan, Maureen

2017-10-01

Causal learning in childhood is a dynamic and collaborative process of explanation and exploration within complex physical and social environments. Understanding how children learn causal knowledge requires examining how they update beliefs about the world given novel information and studying the processes by which children learn in collaboration with caregivers, educators, and peers. The objective of this article is to review evidence for how children learn causal knowledge by explaining and exploring in collaboration with others. We review three examples of causal learning in social contexts, which elucidate how interaction with others influences causal learning. First, we consider children's explanation-seeking behaviors in the form of "why" questions. Second, we examine parents' elaboration of meaning about causal relations. Finally, we consider parents' interactive styles with children during free play, which constrains how children explore. We propose that the best way to understand children's causal learning in social context is to combine results from laboratory and natural interactive informal learning environments.

Atomistic fingerprint of hyaluronan-CD44 binding

DEFF Research Database (Denmark)

Vuorio, Joni; Vattulainen, Ilpo; Martinez-Seara, Hector

2017-01-01

that hyaluronan can bind CD44 with three topographically different binding modes that in unison define an interaction fingerprint, thus providing a plausible explanation for the disagreement between the earlier studies. Our results confirm that the known crystallographic mode is the strongest of the three binding...

The higher returns to formal education for entrepreneurs versus employees

NARCIS (Netherlands)

van Praag, M.; van Witteloostuijn, A.; van der Sluis, J.

2013-01-01

How valuable is formal education for entrepreneurs’ income relative to employees’? And if the income returns to formal education are different for entrepreneurs vis-à-vis employees, what might be a plausible explanation? To explore these questions, we analyze a large representative US panel. We show

Self-employment and Health: Barriers or Benefits?

NARCIS (Netherlands)

C.A. Rietveld (Niels); J.L.W. van Kippersluis (Hans); A.R. Thurik (Roy)

2013-01-01

textabstractThe self-employed are often reported to be healthier than wage workers; however, the cause of this health difference is largely unknown. The longitudinal nature of the US Health and Retirement Study allows us to gauge the plausibility of two competing explanations for this difference: a

Anticipating and Communicating Plausible Environmental and Health Concerns Associated with Future Disasters: The ShakeOut and ARkStorm Scenarios as Examples

Science.gov (United States)

Plumlee, G. S.; Morman, S. A.; Alpers, C. N.; Hoefen, T. M.; Meeker, G. P.

2010-12-01

Disasters commonly pose immediate threats to human safety, but can also produce hazardous materials (HM) that pose short- and long-term environmental-health threats. The U.S. Geological Survey (USGS) has helped assess potential environmental health characteristics of HM produced by various natural and anthropogenic disasters, such as the 2001 World Trade Center collapse, 2005 hurricanes Katrina and Rita, 2007-2009 southern California wildfires, various volcanic eruptions, and others. Building upon experience gained from these responses, we are now developing methods to anticipate plausible environmental and health implications of the 2008 Great Southern California ShakeOut scenario (which modeled the impacts of a 7.8 magnitude earthquake on the southern San Andreas fault, http://urbanearth.gps.caltech.edu/scenario08/), and the recent ARkStorm scenario (modeling the impacts of a major, weeks-long winter storm hitting nearly all of California, http://urbanearth.gps.caltech.edu/winter-storm/). Environmental-health impacts of various past earthquakes and extreme storms are first used to identify plausible impacts that could be associated with the disaster scenarios. Substantial insights can then be gleaned using a Geographic Information Systems (GIS) approach to link ShakeOut and ARkStorm effects maps with data extracted from diverse database sources containing geologic, hazards, and environmental information. This type of analysis helps constrain where potential geogenic (natural) and anthropogenic sources of HM (and their likely types of contaminants or pathogens) fall within areas of predicted ShakeOut-related shaking, firestorms, and landslides, and predicted ARkStorm-related precipitation, flooding, and winds. Because of uncertainties in the event models and many uncertainties in the databases used (e.g., incorrect location information, lack of detailed information on specific facilities, etc.) this approach should only be considered as the first of multiple steps

A Physicist’s Quest in Biology: Max Delbrück and “Complementarity”

Science.gov (United States)

Strauss, Bernard S.

2017-01-01

Max Delbrück was trained as a physicist but made his major contribution in biology and ultimately shared a Nobel Prize in Physiology or Medicine. He was the acknowledged leader of the founders of molecular biology, yet he failed to achieve his key scientific goals. His ultimate scientific aim was to find evidence for physical laws unique to biology: so-called “complementarity.” He never did. The specific problem he initially wanted to solve was the nature of biological replication but the discovery of the mechanism of replication was made by others, in large part because of his disdain for the details of biochemistry. His later career was spent investigating the effect of light on the fungus Phycomyces, a topic that turned out to be of limited general interest. He was known both for his informality but also for his legendary displays of devastating criticism. His life and that of some of his closest colleagues was acted out against a background of a world in conflict. This essay describes the man and his career and searches for an explanation of his profound influence. PMID:28592501

48 CFR 9903.302 - Definitions, explanations, and illustrations of the terms, “cost accounting practice” and “change...

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS CONTRACT COVERAGE CAS Rules and Regulations 9903.302 Definitions, explanations, and... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Definitions, explanations, and illustrations of the terms, âcost accounting practiceâ and âchange to a cost accounting practice.â...

Practicing Possibilities: Parents' Explanations of Unusual Events and Children's Possibility Thinking

Science.gov (United States)

Nolan-Reyes, Charlotte; Callanan, Maureen A.; Haigh, Kirsten A.

2016-01-01

Young children tend to judge improbable events to be impossible, yet there is variability across age and across individuals. Our study examined parent-child conversations about impossible and improbable events and links between parents' explanations about those events and children's possibility judgments in a reasoning task. Regression analyses…

Exploring the Great Schism in the Social Sciences: Confirmation Bias and the Interpretation of Results Relating to Biological Influences on Human Behavior and Psychology.

Science.gov (United States)

Winking, Jeffrey

2018-01-01

The nature-nurture debate is one that biologists often dismiss as a false dichotomy, as all phenotypic traits are the results of complex processes of gene and environment interactions. However, such dismissiveness belies the ongoing debate that is unmistakable throughout the biological and social sciences concerning the role of biological influences in the development of psychological and behavioral traits in humans. Many have proposed that this debate is due to ideologically driven biases in the interpretation of results. Those favoring biological approaches have been accused of a greater willingness to accept biological explanations so as to rationalize or justify the status quo of inequality. Those rejecting biological approaches have been accused of an unwillingness to accept biological explanations so as to attribute inequalities solely to social and institutional factors, ultimately allowing for the possibility of social equality. While it is important to continue to investigate this topic through further research and debate, another approach is to examine the degree to which the allegations of bias are indeed valid. To accomplish this, a convenience sample of individuals with relevant postgraduate degrees was recruited from Mechanical Turk and social media. Participants were asked to rate the inferential power of different research designs and of mock results that varied in the degree to which they supported different ideologies. Results were suggestive that researchers harbor sincere differences of opinion concerning the inferential value of relevant research. There was no suggestion that ideological confirmation biases drive these differences. However, challenges associated with recruiting a large enough sample of experts as well as identifying believable mock scenarios limit the study's inferential scope.

Acceleration of particles by black holes: Kinematic explanation

International Nuclear Information System (INIS)

Zaslavskii, O. B.

2011-01-01

A new simple and general explanation of the effect of acceleration of particles by black holes to infinite energies in the center of mass frame is suggested. It is based on kinematics of particles moving near the horizon. This effect arises when particles of two kinds collide near the horizon. For massive particles, the first kind represents a particle with the generic energy and angular momentum (I call them ''usual''). Near the horizon, such a particle has a velocity almost equal to that of light in the frame that corotates with a black hole (the frame is static if a black hole is static). The second kind (called ''critical'') consists of particles with the velocity v< c near the horizon due to special relationship between the energy and angular momentum (or charge). As a result, the relative velocity approaches the speed of light c, and the Lorentz factor grows unbound. This explanation applies both to generic rotating black holes and charged ones (even for radial motion of particles). If one of the colliding particles is massless (photon), the critical particle is distinguished by the fact that its frequency is finite near the horizon. The existence (or absence) of the effect is determined depending on competition of two factors--gravitational blue shift for a photon propagating towards a black hole and the Doppler effect due to transformation from the locally nonrotating frame to a comoving one. Classification of all possible types of collisions is suggested depending on whether massive or massless particle is critical or usual.

WomenÕs Advancement in the Accounting Profession: Consideration of Person-Centered and Organization-Centered Explanations

OpenAIRE

Janet S. Omundson; Richard G. Schroeder; Mary B. Stevens

1997-01-01

Today, communication skills are among the most popular content areas in employee training. This survey of training managers examined the status of communication training in businesDespite the entry of large numbers of women into the accounting profession over the last decade, few women have reached top management levels. Two alternative paradigms that attempt to explain this phenomenon are the person-centered explanation and the organization-centered explanation. This study explores the Type ...

Supporting students' scientific explanations: A case study investigating the synergy focusing on a teacher's practices when providing instruction and using mobile devices

Science.gov (United States)

Delen, Ibrahim

Engage students in constructing scientific practices is a critical component of science instruction. Therefore a number of researchers have developed software programs to help students and teachers in this hard task. The Zydeco group, designed a mobile application called Zydeco, which enables students to collect data inside and outside the classroom, and then use the data to create scientific explanations by using claim-evidence-reasoning framework. Previous technologies designed to support scientific explanations focused on how these programs improve students' scientific explanations, but these programs ignored how scientific explanation technologies can support teacher practices. Thus, to increase our knowledge how different scaffolds can work together, this study aimed to portray the synergy between a teacher's instructional practices (part 1) and using supports within a mobile devices (part 2) to support students in constructing explanations. Synergy can be thought of as generic and content-specific scaffolds working together to enable students to accomplish challenging tasks, such as creating explanations that they would not normally be able to do without the scaffolds working together. Providing instruction (part 1) focused on understanding how the teacher scaffolds students' initial understanding of the claim-evidence-reasoning (CER) framework. The second component of examining synergy (part 2: using mobile devices) investigated how this teacher used mobile devices to provide feedback when students created explanations. The synergy between providing instruction and using mobile devices was investigated by analyzing a middle school teacher's practices in two different units (plants and water quality). Next, this study focused on describing how the level of synergy influenced the quality of students' scientific explanations. Finally, I investigated the role of focused teaching intervention sessions to inform teacher in relation to students' performance. In

Quantitative global sensitivity analysis of a biologically based dose-response pregnancy model for the thyroid endocrine system.

Science.gov (United States)

Lumen, Annie; McNally, Kevin; George, Nysia; Fisher, Jeffrey W; Loizou, George D

2015-01-01

A deterministic biologically based dose-response model for the thyroidal system in a near-term pregnant woman and the fetus was recently developed to evaluate quantitatively thyroid hormone perturbations. The current work focuses on conducting a quantitative global sensitivity analysis on this complex model to identify and characterize the sources and contributions of uncertainties in the predicted model output. The workflow and methodologies suitable for computationally expensive models, such as the Morris screening method and Gaussian Emulation processes, were used for the implementation of the global sensitivity analysis. Sensitivity indices, such as main, total and interaction effects, were computed for a screened set of the total thyroidal system descriptive model input parameters. Furthermore, a narrower sub-set of the most influential parameters affecting the model output of maternal thyroid hormone levels were identified in addition to the characterization of their overall and pair-wise parameter interaction quotients. The characteristic trends of influence in model output for each of these individual model input parameters over their plausible ranges were elucidated using Gaussian Emulation processes. Through global sensitivity analysis we have gained a better understanding of the model behavior and performance beyond the domains of observation by the simultaneous variation in model inputs over their range of plausible uncertainties. The sensitivity analysis helped identify parameters that determine the driving mechanisms of the maternal and fetal iodide kinetics, thyroid function and their interactions, and contributed to an improved understanding of the system modeled. We have thus demonstrated the use and application of global sensitivity analysis for a biologically based dose-response model for sensitive life-stages such as pregnancy that provides richer information on the model and the thyroidal system modeled compared to local sensitivity analysis.

Quantitative global sensitivity analysis of a biologically based dose-response pregnancy model for the thyroid endocrine system

Directory of Open Access Journals (Sweden)

Annie eLumen

2015-05-01

Full Text Available A deterministic biologically based dose-response model for the thyroidal system in a near-term pregnant woman and the fetus was recently developed to evaluate quantitatively thyroid hormone perturbations. The current work focuses on conducting a quantitative global sensitivity analysis on this complex model to identify and characterize the sources and contributions of uncertainties in the predicted model output. The workflow and methodologies suitable for computationally expensive models, such as the Morris screening method and Gaussian Emulation processes, were used for the implementation of the global sensitivity analysis. Sensitivity indices, such as main, total and interaction effects, were computed for a screened set of the total thyroidal system descriptive model input parameters. Furthermore, a narrower sub-set of the most influential parameters affecting the model output of maternal thyroid hormone levels were identified in addition to the characterization of their overall and pair-wise parameter interaction quotients. The characteristic trends of influence in model output for each of these individual model input parameters over their plausible ranges were elucidated using Gaussian Emulation processes. Through global sensitivity analysis we have gained a better understanding of the model behavior and performance beyond the domains of observation by the simultaneous variation in model inputs over their range of plausible uncertainties. The sensitivity analysis helped identify parameters that determine the driving mechanisms of the maternal and fetal iodide kinetics, thyroid function and their interactions, and contributed to an improved understanding of the system modeled. We have thus demonstrated the use and application of global sensitivity analysis for a biologically based dose-response model for sensitive life-stages such as pregnancy that provides richer information on the model and the thyroidal system modeled compared to local

Radiometric method and abnormal explanation of landslide survey

International Nuclear Information System (INIS)

Ye Shulin; Sun Zhanxue; Luo Liangsheng

2003-01-01

Radioactivity exploration mechanism of landslide is researched. Radioactive measure technical and its anomaly explanation models of application is introduced. Test verification result of landslide body geological form (boundary and landslide body thickness) in the district of Wanzhou 233 of Chongqing city ancients landslide and the Yunyang new county Zhaiba landslide shows, it can be used in determining the body boundary (reason) line, investigating the underground current direction and landslide body moving direction, explaining that calculation of weathered zone thickness of landslide body. It can also increase the geological effect of landslide exploration in adaption with geology and drilling

The Roles of Competence Beliefs and Goal Orientations for Change in Intrinsic Motivation

Science.gov (United States)

Spinath, Birgit; Steinmayr, Ricarda

2012-01-01

The present study investigated 3 theoretically plausible explanations for changes in school-related intrinsic motivation. A sample of 348 German 11th-grade students was followed for 1 year. At 2 measurement occasions, students completed self-reports regarding their school-related intrinsic motivation, goal orientations, and competence beliefs. In…

Principles of Economics without the Prince of Denmark

Science.gov (United States)

Phipps, Barbara J.; Strom, Robert J.; Baumol, William J.

2012-01-01

In most introductory textbooks on principles of economics, discussion of the theory or practice of entrepreneurship is almost entirely absent. This omission is striking, given the important role in economic growth that economists assign to the entrepreneur. While there are plausible explanations for this omission, new research suggests the…

Commentary

African Journals Online (AJOL)

Ramakantb

is most likely a tip of iceberg, as several cases of stroke in Africa rarely get to hospital before death. Plausible explanations for this include poor transportation system, limited access to healthcare, limited neurodiagnostic facility, deficient acute interventional therapy, dearth of medical experts, poor recognition of symptoms of ...

What works with worked examples: Extending self-explanation and analogical comparison to synthesis problems

Science.gov (United States)

Badeau, Ryan; White, Daniel R.; Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.

2017-12-01

The ability to solve physics problems that require multiple concepts from across the physics curriculum—"synthesis" problems—is often a goal of physics instruction. Three experiments were designed to evaluate the effectiveness of two instructional methods employing worked examples on student performance with synthesis problems; these instructional techniques, analogical comparison and self-explanation, have previously been studied primarily in the context of single-concept problems. Across three experiments with students from introductory calculus-based physics courses, both self-explanation and certain kinds of analogical comparison of worked examples significantly improved student performance on a target synthesis problem, with distinct improvements in recognition of the relevant concepts. More specifically, analogical comparison significantly improved student performance when the comparisons were invoked between worked synthesis examples. In contrast, similar comparisons between corresponding pairs of worked single-concept examples did not significantly improve performance. On a more complicated synthesis problem, self-explanation was significantly more effective than analogical comparison, potentially due to differences in how successfully students encoded the full structure of the worked examples. Finally, we find that the two techniques can be combined for additional benefit, with the trade-off of slightly more time on task.

A plausible mechanism of biosorption in dual symbioses by vesicular-arbuscular mycorrhizal in plants.

Science.gov (United States)

Azmat, Rafia; Hamid, Neelofer

2015-03-01

Dual symbioses of vesicular-arbuscular mycorrhizal (VAM) fungi with growth of Momordica charantia were elucidated in terms of plausible mechanism of biosorption in this article. The experiment was conducted in green house and mixed inoculum of the VAM fungi was used in the three replicates. Results demonstrated that the starch contents were the main source of C for the VAM to builds their hyphae. The increased plant height and leaves surface area were explained in relation with an increase in the photosynthetic rates to produce rapid sugar contents for the survival of plants. A decreased in protein, and amino acid contents and increased proline and protease activity in VAM plants suggested that these contents were the main bio-indicators of the plants under biotic stress. The decline in protein may be due to the degradation of these contents, which later on converted into dextrose where it can easily be absorbed by for the period of symbioses. A mechanism of C chemisorption in relation with physiology and morphology of plant was discussed.

The Diboson Excess: Experimental Situation and Classification of Explanations; A Les Houches Pre-Proceeding

CERN Document Server

Brehmer, Johann; Cacciapaglia, Giacomo; Carmona, Adrian; Chivukula, R.Sekhar; Delgado, Antonio; Goertz, Florian; Hewett, JoAnne L.; Katz, Andrey; Kopp, Joachim; Lane, Kenneth; Martin, Adam; Mohan, Kirtimaan; Morse, David M.; Nardecchia, Marco; No, Jose Miguel; Oliveira, Alexandra; Pollard, Chris; Quiros, Mariano; Rizzo, Thomas G.; Santiago, Jose; Sanz, Veronica; Simmons, Elizabeth H.; Tattersall, Jamie

2015-01-01

We examine the `diboson' excess at $\\sim 2$ TeV seen by the LHC experiments in various channels. We provide a comparison of the excess significances as a function of the mass of the tentative resonance and give the signal cross sections needed to explain the excesses. We also present a survey of available theoretical explanations of the resonance, classified in three main approaches. Beyond that, we discuss methods to verify the anomaly, determining the major properties of the various surpluses and exploring how different models can be discriminated. Finally, we give a tabular summary of the numerous explanations, presenting their main phenomenological features.

Biological Small Angle Scattering: Techniques, Strategies and Tips

Energy Technology Data Exchange (ETDEWEB)

Chaudhuri, Barnali [University at Buffalo (SUNY); Muñoz, Inés G. [Centro Nacional de Investigaciones Oncológicas Madrid, Madrid, Spain; Urban, Volker S. [ORNL; Qian, Shuo [ORNL

2017-12-01

This book provides a clear, comprehensible and up-to-date description of how Small Angle Scattering (SAS) can help structural biology researchers. SAS is an efficient technique that offers structural information on how biological macromolecules behave in solution. SAS provides distinct and complementary data for integrative structural biology approaches in combination with other widely used probes, such as X-ray crystallography, Nuclear magnetic resonance, Mass spectrometry and Cryo-electron Microscopy. The development of brilliant synchrotron small-angle X-ray scattering (SAXS) beam lines has increased the number of researchers interested in solution scattering. SAS is especially useful for studying conformational changes in proteins, highly flexible proteins, and intrinsically disordered proteins. Small-angle neutron scattering (SANS) with neutron contrast variation is ideally suited for studying multi-component assemblies as well as membrane proteins that are stabilized in surfactant micelles or vesicles. SAS is also used for studying dynamic processes of protein fibrillation in amyloid diseases, and pharmaceutical drug delivery. The combination with size-exclusion chromatography further increases the range of SAS applications.The book is written by leading experts in solution SAS methodologies. The principles and theoretical background of various SAS techniques are included, along with practical aspects that range from sample preparation to data presentation for publication. Topics covered include techniques for improving data quality and analysis, as well as different scientific applications of SAS. With abundant illustrations and practical tips, we hope the clear explanations of the principles and the reviews on the latest progresses will serve as a guide through all aspects of biological solution SAS.The scope of this book is particularly relevant for structural biology researchers who are new to SAS. Advanced users of the technique will find it helpful for

The application of contrast explanation to energy policy research: UK nuclear energy policy 2002–2012

International Nuclear Information System (INIS)

Heffron, Raphael J.

2013-01-01

This paper advances the application of the methodology, contrast explanation, to energy policy research. Research in energy policy is complex and often involves inter-disciplinary work, which traditional economic methodologies fail to capture. Consequently, the more encompassing methodology of contrast explanation is assessed and its use in other social science disciplines explored in brief. It is then applied to an energy policy research topic—in this case, nuclear energy policy research in the UK. Contrast explanation facilitates research into policy and decision-making processes in energy studies and offers an alternative to the traditional economic methods used in energy research. Further, contrast explanation is extended by the addition of contested and uncontested hypotheses analyses. This research focuses on the methods employed to deliver the new nuclear programme of the UK government. In order to achieve a sustainable nuclear energy policy three issues are of major importance: (1) law, policy and development; (2) public administration; and (3) project management. Further, the research identifies that policy in the area remains to be resolved, in particular at an institutional and legal level. However, contrary to the literature, in some areas, the research identifies a change of course as the UK concentrates on delivering a long-term policy for the nuclear energy sector and the overall energy sector. - Highlights: ► Energy policy research is interdisciplinary and needs additional methodological approaches. ► New method of contrast explanation advanced for energy policy research. ► This methodology is based on dialectical learning which examines conflict between sources of data. ► Research example used here is of UK nuclear energy policy. ► Major issues in UK nuclear energy policy are planning law, public administration, and project management

Complexity and demographic explanations of cumulative culture.

Science.gov (United States)

Querbes, Adrien; Vaesen, Krist; Houkes, Wybo

2014-01-01

Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century) to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

Knowledge-fused differential dependency network models for detecting significant rewiring in biological networks.

Science.gov (United States)

Tian, Ye; Zhang, Bai; Hoffman, Eric P; Clarke, Robert; Zhang, Zhen; Shih, Ie-Ming; Xuan, Jianhua; Herrington, David M; Wang, Yue

2014-07-24

Modeling biological networks serves as both a major goal and an effective tool of systems biology in studying mechanisms that orchestrate the activities of gene products in cells. Biological networks are context-specific and dynamic in nature. To systematically characterize the selectively activated regulatory components and mechanisms, modeling tools must be able to effectively distinguish significant rewiring from random background fluctuations. While differential networks cannot be constructed by existing knowledge alone, novel incorporation of prior knowledge into data-driven approaches can improve the robustness and biological relevance of network inference. However, the major unresolved roadblocks include: big solution space but a small sample size; highly complex networks; imperfect prior knowledge; missing significance assessment; and heuristic structural parameter learning. To address these challenges, we formulated the inference of differential dependency networks that incorporate both conditional data and prior knowledge as a convex optimization problem, and developed an efficient learning algorithm to jointly infer the conserved biological network and the significant rewiring across different conditions. We used a novel sampling scheme to estimate the expected error rate due to "random" knowledge. Based on that scheme, we developed a strategy that fully exploits the benefit of this data-knowledge integrated approach. We demonstrated and validated the principle and performance of our method using synthetic datasets. We then applied our method to yeast cell line and breast cancer microarray data and obtained biologically plausible results. The open-source R software package and the experimental data are freely available at http://www.cbil.ece.vt.edu/software.htm. Experiments on both synthetic and real data demonstrate the effectiveness of the knowledge-fused differential dependency network in revealing the statistically significant rewiring in biological

SPIRIT 2013 explanation and elaboration: guidance for protocols of clinical trials.

Science.gov (United States)

Chan, An-Wen; Tetzlaff, Jennifer M; Gøtzsche, Peter C; Altman, Douglas G; Mann, Howard; Berlin, Jesse A; Dickersin, Kay; Hróbjartsson, Asbjørn; Schulz, Kenneth F; Parulekar, Wendy R; Krleza-Jeric, Karmela; Laupacis, Andreas; Moher, David

2013-01-08

High quality protocols facilitate proper conduct, reporting, and external review of clinical trials. However, the completeness of trial protocols is often inadequate. To help improve the content and quality of protocols, an international group of stakeholders developed the SPIRIT 2013 Statement (Standard Protocol Items: Recommendations for Interventional Trials). The SPIRIT Statement provides guidance in the form of a checklist of recommended items to include in a clinical trial protocol. This SPIRIT 2013 Explanation and Elaboration paper provides important information to promote full understanding of the checklist recommendations. For each checklist item, we provide a rationale and detailed description; a model example from an actual protocol; and relevant references supporting its importance. We strongly recommend that this explanatory paper be used in conjunction with the SPIRIT Statement. A website of resources is also available (www.spirit-statement.org). The SPIRIT 2013 Explanation and Elaboration paper, together with the Statement, should help with the drafting of trial protocols. Complete documentation of key trial elements can facilitate transparency and protocol review for the benefit of all stakeholders.

Study to paraphrase nuclear technical terms with clear and brief explanations

International Nuclear Information System (INIS)

Shobu, Nobuhiro; Takashita, Hirofumi; Horikoshi, Hidehiko; Osawa, Yukiko

2010-01-01

This report summarizes the review work to paraphrase nuclear technical terms with clear and brief explanations. Explanation with nuclear technical terms was not very acceptable to the public in a variety of contexts. The objective of this study is not to paraphrase with the expert's ideas but to paraphrase from the public point of view. Japan Atomic Energy Agency (hereafter abbreviated as 'JAEA') has conducted a survey on public attitudes toward fifty-nine nuclear technical terms by using an online questionnaire. Most of them were frequently used in the brochures of Nuclear fuel Cycle Engineering Laboratories of JAEA. The survey clarified the public awareness and comprehension of each term. Thirty-two terms, which was subject to paraphrase on a priority basis, were selected from fifty-nine nuclear technical terms based on our importance rating. At the work to paraphrase thirty-two terms, emphasis was placed more on clearness and briefness than on scientific/technical accuracy. They are reviewed through focus group interviews. This study brought results on recognizable style and thirty-two well-polished paraphrases. (author)

DEMAND FOR AND SUPPLY OF MARK-UP AND PLS FUNDS IN ISLAMIC BANKING: SOME ALTERNATIVE EXPLANATIONS

OpenAIRE

KHAN, TARIQULLAH

1995-01-01

Profit and loss-sharing (PLS) and bai’ al murabahah lil amir bil shira (mark-up) are the two parent principles of Islamic financing. The use of PLS is limited and that of mark-up overwhelming in the operations of the Islamic banks. Several studies provide different explanations for this phenomenon. The dominant among these is the moral hazard hypothesis. Some alternative explanations are given in the present paper. The discussion is based on both demand (user of funds) and supply (bank) side ...

Donald Redfield Griffin

Indian Academy of Sciences (India)

Internationally renowned for his work on animal behaviour, ... explain the bat's ability to avoid obstacles. At that time, this seemed to be a more plausible explanation and was accepted by zoologists for over a century and virtually no further experi- ments were .... In 1943, Sven Dijkgraaf of Holland independently discovered.

Instability in self-esteem and paranoia in a general population sample

OpenAIRE

Thewissen, Viviane; Myin-Germeys, Inez; Bentall, Richard; de Graaf, Ron; Vollebergh, Wilma; van Os, Jim

2007-01-01

Research on the association between paranoia and self-esteem has yielded inconsistent findings. Some studies have indicated an association between paranoia and low self-esteem, while other studies have shown an association with high self-esteem. A plausible explanation for these inconsistencies is that self-esteem is unstable in paranoid individuals.

The biological function of consciousness

Directory of Open Access Journals (Sweden)

Brian eEarl

2014-08-01

Full Text Available This research is an investigation of whether consciousness—one’s ongoing experience—influences one’s behavior and, if so, how. Analysis of the components, structure, properties, and temporal sequences of consciousness has established that, (1 contrary to one’s intuitive understanding, consciousness does not have an active, executive role in determining behavior; (2 consciousness does have a biological function; and (3 consciousness is solely information in various forms. Consciousness is associated with a flexible response mechanism (FRM for decision-making, planning, and generally responding in nonautomatic ways. The FRM generates responses by manipulating information and, to function effectively, its data input must be restricted to task-relevant information. The properties of consciousness correspond to the various input requirements of the FRM; and when important information is missing from consciousness, functions of the FRM are adversely affected; both of which indicate that consciousness is the input data to the FRM. Qualitative and quantitative information (shape, size, location, etc., is incorporated into the input data by a qualia array of colors, sounds, and so on, which makes the input conscious. This view of the biological function of consciousness provides an explanation why we have experiences; why we have emotional and other feelings, and why their loss is associated with poor decision-making; why blindsight patients do not spontaneously initiate responses to events in their blind field; why counter-habitual actions are only possible when the intended action is in mind; and the reason for inattentional blindness.

The geomagnetic field - An explanation for the microturbulence in coaxial gun plasmas

International Nuclear Information System (INIS)

Mather, J.W.; Ahluwalia, H.S.

1988-01-01

The authors describe the complexity introduced by the geomagnetic field in several regions of a coaxial gun plasma device. It is shown that the annihilation of the swept-up geomagnetic flux, trapped within the highly compressed turbulent plasma, provides an explanation for varied performance and experimental results

Cultural Explanations of Sleep Paralysis in Italy: The Pandafeche Attack and Associated Supernatural Beliefs.

Science.gov (United States)

Jalal, Baland; Romanelli, Andrea; Hinton, Devon E

2015-12-01

The current study examines cultural explanations regarding sleep paralysis (SP) in Italy. The study explores (1) whether the phenomenology of SP generates culturally specific interpretations and causal explanations and (2) what are the beliefs and local traditions associated with such cultural explanations. The participants were Italian nationals from the general population (n = 68) recruited in the region of Abruzzo, Italy. All participants had experienced at least one lifetime episode of SP. The sleep paralysis experiences and phenomenology questionnaire were orally administered to participants. We found a multilayered cultural interpretation of SP, namely the Pandafeche attack, associated with various supernatural beliefs. Thirty-eight percent of participants believed that this supernatural being, the Pandafeche-often referred to as an evil witch, sometimes as a ghost-like spirit or a terrifying humanoid cat-might have caused their SP. Twenty-four percent of all participants sensed the Pandafeche was present during their SP. Strategies to prevent Pandafeche attack included sleeping in supine position, placing a broom by the bedroom door, or putting a pile of sand by the bed. Case studies are presented to illustrate the study findings. The Pandafeche attack thus constitutes a culturally specific, supernatural interpretation of the phenomenology of SP in the Abruzzo region of Italy.

The biology of human psychosexual differentiation.

Science.gov (United States)

Gooren, Louis

2006-11-01

Most attempts to identify biological underpinnings of gender identity and sexual orientation in humans have investigated effects of sex steroids, so pivotal in the differentiation of the genitalia, showing strong parallels between animals and the human. The information on humans is derived from the so-called 'experiments of nature', clinical entities with a lesser-than-normal androgen exposure in XY subjects and a higher than normal androgen exposure in XX subjects. Prenatal androgenization appears to predispose to a male gender identity development, but apparently not decisively since 40-50% of 46,XY intersexed children with a history of prenatal androgen exposure do not develop a male gender identity. Obviously, male-to-female transsexuals, with a normal androgen exposure prenatally (there is no serious evidence to the contrary) develop a female gender identity, through unknown biological mechanisms apparently overriding the effects of prenatal androgens. The latest studies in 46, XX subjects exposed to prenatal androgens show that prenatal androgenization of 46,XX fetuses leads to marked masculinization of later gender-related behavior but does not lead to gender confusion/dysphoria. The example of female-to-male transsexuals, without evidence of prenatal androgen exposure, indicates that a male gender identity can develop without a significant androgen stimulus. So we are far away from any comprehensive understanding of hormonal imprinting on gender identity formation. Brain studies in homosexuals have not held up in replication studies or are in need of replication in transsexuals. Genetic studies and the fraternal birth order hypothesis provide indications of familial clustering of homosexuality but in many homosexuals these genetic patterns cannot be identified. The biological explanations advanced for the birth order hypothesis lack any experimental support.

Evaluation of Explanation Interfaces in Recommender Systems

Directory of Open Access Journals (Sweden)

Sergio Cleger-Tamayo

2017-05-01

Full Text Available Explaining interfaces become a useful tool in systems that have a lot of content to evaluate by users. The different interfaces represent a help for the undecided users or those who consider systems as boxed black smart. These systems present recommendations to users based on different learning models. In this paper, we present the different objectives of the explanation interfaces and some of the criteria that you can evaluate, as well as a proposal of metrics to obtain results in the experiments. Finally, we showed the main results of a study with real users and their interaction with e-commerce systems. Among the main results, highlight the positive impact in relation to the time of interaction with the applications and acceptance of the recommendations received.

Complexity and demographic explanations of cumulative culture.

Directory of Open Access Journals (Sweden)

Adrien Querbes

Full Text Available Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

Causation at Different Levels: Tracking the Commitments of Mechanistic Explanations

DEFF Research Database (Denmark)

Fazekas, Peter; Kertész, Gergely

2011-01-01

connections transparent. These general commitments get confronted with two claims made by certain proponents of the mechanistic approach: William Bechtel often argues that within the mechanistic framework it is possible to balance between reducing higher levels and maintaining their autonomy at the same time...... their autonomy at the same time than standard reductive accounts are, and that what mechanistic explanations are able to do at best is showing that downward causation does not exist....

Comment on McCall, Trombetta, and Gipe's 2004 proposed impression management explanation for the credit card effect.

Science.gov (United States)

Spangenberg, Eric R

2005-08-01

There is a dearth of empirically supported theoretical explanation since its introduction; Feinberg's 1986 credit card effect showed greater product valuations and donation intentions by experimental participants when asked to make such estimates in the presence of credit card stimuli. This comment on McCall, Trombetta, and Gipe (2004) notes potential flaws and adjudged over-interpretation of results in their attempt to replicate successfully and derive theoretical explanation for the credit card effect.

Coding Scheme for Assessment of Students’ Explanations and Predictions

Directory of Open Access Journals (Sweden)

Mihael Gojkošek

2017-04-01

Full Text Available In the process of analyzing students’ explanations and predictions for interaction between brightness enhancement film and beam of white light, a need for objective and reliable assessment instrumentarose. Consequently, we developed a codingscheme that was mostly inspired by the rubrics for self-assessment of scientific abilities. In the paper we present the grading categories that were integrated in the coding scheme, and descriptions of criteria used for evaluation of students work. We report the results of reliability analysis of new assessment tool and present some examples of its application.

Allometric Scaling in Biology

Science.gov (United States)

Banavar, Jayanth

2009-03-01

The unity of life is expressed not only in the universal basis of inheritance and energetics at the molecular level, but also in the pervasive scaling of traits with body size at the whole-organism level. More than 75 years ago, Kleiber and Brody and Proctor independently showed that the metabolic rates, B, of mammals and birds scale as the three-quarter power of their mass, M. Subsequent studies showed that most biological rates and times scale as M-1/4 and M^1/4 respectively, and that these so called quarter-power scaling relations hold for a variety of organisms, from unicellular prokaryotes and eukaryotes to trees and mammals. The wide applicability of Kleiber's law, across the 22 orders of magnitude of body mass from minute bacteria to giant whales and sequoias, raises the hope that there is some simple general explanation that underlies the incredible diversity of form and function. We will present a general theoretical framework for understanding the relationship between metabolic rate, B, and body mass, M. We show how the pervasive quarter-power biological scaling relations arise naturally from optimal directed resource supply systems. This framework robustly predicts that: 1) whole organism power and resource supply rate, B, scale as M^3/4; 2) most other rates, such as heart rate and maximal population growth rate scale as M-1/4; 3) most biological times, such as blood circulation time and lifespan, scale as M^1/4; and 4) the average velocity of flow through the network, v, such as the speed of blood and oxygen delivery, scales as M^1/12. Our framework is valid even when there is no underlying network. Our theory is applicable to unicellular organisms as well as to large animals and plants. This work was carried out in collaboration with Amos Maritan along with Jim Brown, John Damuth, Melanie Moses, Andrea Rinaldo, and Geoff West.

Using Discourse Analysis to Understand Variation in Students' Reasoning from Accepted Ways of Reasoning

Science.gov (United States)

Gruver, John

2017-01-01

In this study, I use a systemic functional linguistics approach to examine mathematics classroom discourse with the aim of providing a plausible explanation of how students could actively participate in productive classroom discussions without adopting ways of reasoning that were accepted in the classroom community. In this way, I work in the…

Tools for searching resonant moving groups in Galactic disc simulations

NARCIS (Netherlands)

Roca, S.; Romero-Gomez, M.; Antoja Castelltort, Teresa; Valenzuela, O.; Figuera, F.; Monguio, M.

One of the most plausible explanations for the origin of the moving groups is the orbital and resonant regions related to the large scale structure (bar and spiral arms) of the Milky Way (Antoja 2010). This study has been up to now restricted to the solar radius. Here we propose to investigate the

How to Do Things with Mouse Clicks: Applying Austin's Speech Act Theory to Explain Learning in Virtual Worlds

Science.gov (United States)

Loke, Swee-Kin; Golding, Clinton

2016-01-01

This article addresses learning in desktop virtual worlds where students role play for professional education. When students role play in such virtual worlds, they can learn some knowledge and skills that are useful in the physical world. However, existing learning theories do not provide a plausible explanation of how performing non-verbal…

Political Culture versus Socioeconomic Approaches to Predicting Police Strength in U.S. Police Agencies: Results of a Longitudinal Study, 1993 to 2003

Science.gov (United States)

Zhao, Jihong; Ren, Ling; Lovrich, Nicholas P.

2012-01-01

A variety of theories have emerged that offer plausible explanations, one from the political institutional perspective and others from sociological perspective. There has been renewed interest in the effect of local political structure on police strength in the policing literature. The purpose of this study, therefore, is to assess the two main…

Distinguishing the City, Neighbourhood and Individual Level in the Explanation of Youth Delinquency

NARCIS (Netherlands)

Weijters, Gijs; Scheepers, Peer; Gerris, Jan

2007-01-01

Previous research on intercity differences in crime rates neglects individual determinants of youth delinquency, whereas studies focusing on neighbourhoodand individual-level explanations of youth delinquency neglect higher-level, city characteristics. This raises the question of the extent to which

Bipolar disorder: idioms of susceptibility and disease and the role of 'genes' in illness explanations.

Science.gov (United States)

Baart, Ingrid; Widdershoven, Guy

2013-11-01

This qualitative study explores (1) how members of the Dutch Association for People with Bipolar Disorder explain the affliction of bipolar disorder; (2) the relationship between genetic, environmental and personal factors in these explanations and (3) the relationship between illness explanations, self-management and identity. A total of 40 participants took part in seven different focus group discussions. The results demonstrate that there are two different explanatory idioms, each one centred around an opposing concept, that is, susceptibility and disease. Individuals who construct explanations around the concept of 'disease' attach more importance to 'genes and chemicals' than to environmental components in the onset of the disorder, whereas individuals adhering to the central concept of 'susceptibility' tend to do this much less. Compared with individuals using the 'susceptibility' idiom, those who use a 'disease' idiom tend to observe fewer possibilities for self-management and are less inclined to construct normalcy through a quest for personal growth. Stories of suffering seem more integral to the 'disease' idiom than to the 'susceptibility' idiom. The 'disease' idiom seems less integrated in a contemporary surveillance psychiatric discourse than the 'susceptibility' idiom; however, both vocabularies can offer normative constraints.

The Perennial Debate: Nature, Nurture, or Choice? Black and White Americans' Explanations for Individual Differences

Science.gov (United States)

Jayaratne, Toby Epstein; Gelman, Susan A.; Feldbaum, Merle; Sheldon, Jane P.; Petty, Elizabeth M.; Kardia, Sharon L.R.

2009-01-01

This paper examines three common explanations for human characteristics: genes, the environment, and choice. Based on data from a representative sample of White and Black Americans, respondents indicated how much they believed each factor influenced individual differences in athleticism, nurturance, drive, math ability, violence, intelligence, and sexual orientation. Results show that across traits: 1) Black respondents generally favor choice and reject genetic explanations, whereas White respondents indicate less causal consistency; 2) although a sizeable subset of respondents endorse just one factor, most report multiple factors as at least partly influential; and 3) among White respondents greater endorsement of genetic explanations is associated with less acceptance of choice and the environment, although among Black respondents a negative relationship holds only between genes and choice. The social relevance of these findings is discussed within the context of the attribution, essentialism and lay theory literature. The results underscore the need to consider more complex and nuanced issues than are implied by the simplistic, unidimensional character of the nature/nurture and determinism/free will debates — perennial controversies that have significance in the current genomic era. PMID:20072661

Adaptive Problem Solving and Decision Making in Complex and Changing Environments: The Role of Understanding and Explanation

Science.gov (United States)

2010-02-28

34In the population as a whole, people tend to prefer Pepsi to Coke about as often as they prefer Coke to Pepsi . However, it turns out that ministers...tend to prefer Pepsi over Coke," and asked them to generate an explanation for this "fact". Their subjects had no difficulty doing so, and all their...explanations drew on multiple sources of knowledge, including knowledge about ministers, Coke and Pepsi both as products and corporations, and

How the explanation of LENR can be made consistent with observed behaviour and natural laws

International Nuclear Information System (INIS)

Storms, Edmund

2015-01-01

The phenomenon called 'cold fusion' or low energy nuclear reaction has been a challenge to accept and explain. The problem is compounded because an effective explanation must be consistent with the observed behaviour and natural laws. Hundreds of explanations have been published, but none was able to meet this expectation. Consequently, acceptance of the phenomenon by conventional science and application of the energy have been handicapped. The present article summarizes an effort to reduce this problem by identifying a few critical requirements and proposing a mechanism that is consistent with these requirements. This model can also predict many behaviours of importance to science and commercial applications. (author)

Data for the elaboration of the CIPROS checklist with items for a patient registry software system: Examples and explanations

Directory of Open Access Journals (Sweden)

Doris Lindoerfer

2017-10-01

The data presented per checklist item provide the relevant textual information (examples and a first qualitative summary (explanation. The examples and explanations provide the background information on CIPROS. They elucidate how to implement the checklist items in other projects. The literature list and the selected texts serve as a reference for scientists and system developers.

Diquarks as an explanation for psi's R, and everything else

Energy Technology Data Exchange (ETDEWEB)

Pavkovic, M [Stanford Univ., Calif. (USA). School of Medicine

1976-06-05

In order to overcome some contradictions and limitations in the charm model without introducing new quantum numbers, a new quark model is required. The letter presents a candidate for such a model. Some tests of the model are discussed including the explanation of the observed behaviour of R=sigma(e/sup +/e/sup -/..-->..hadrons)/sigma(e/sup +/e/sup -/ ..--> mu..sup(+)..mu..sup(-)) and the narrow width of psi's. Moreover some predictions of the model are illustrated.

Religiousness, well-being and ageing – selected explanations of positive relationships

Directory of Open Access Journals (Sweden)

Woźniak Barbara

2015-12-01

Full Text Available According to research that have been conducted in the field of gerontology, sociology and psychology of ageing, there is a relationship between the level of religious involvement and health status/ well-being/quality of life in older age. How does religiousness influence aging process and health status? The aim of the article is to review explanations of a positive relationship between religiousness and health that are discussed in the literature. Those explanations may be grouped in three broad categories reflecting three functions of religion that play a role for well-being in older age. Those functions are: (1 religiousness as a source of coherence and the role of religious coping and provision of meaning in dealing with stressful life events (including ageing losses (2 religiousness as a source of positive self-perception and a sense of personal control, (3 provision of social resources (i.e. social ties and social support within religious community and emphasis on interpersonal relations (with special focus on forgiveness as a norm in interpersonal relations. Those functions of religion are discussed in the context of their potential role in successful ageing, as determined by - among others - active engagement in life.

A flavor-safe composite explanation of $R_K$

CERN Document Server

Carmona, Adrian

2017-05-04

In these proceedings we discuss a flavor-safe explanation of the anomaly found in $R_K= {\\cal B}(B \\to K \\mu^+ \\mu^-)/{\\cal B}(B \\to K e^+ e^-)$ by LHCb, within the framework of composite Higgs models. We present a model featuring a non-negligible degree of compositeness for all three generations of right-handed leptons, which leads to a violation of lepton-flavor universality in neutral current interactions while other constraints from quark- and lepton-flavor physics are met. Moreoever, the particular embedding of the lepton sector considered in this setup provides a parametrically enhanded contribution to the Higgs mass that can weak considerably the need for ultra-light top partners.

The missing link between sleep disorders and age-related dementia: recent evidence and plausible mechanisms.

Science.gov (United States)

Zhang, Feng; Zhong, Rujia; Li, Song; Chang, Raymond Chuen-Chung; Le, Weidong

2017-05-01

Sleep disorders are among the most common clinical problems and possess a significant concern for the geriatric population. More importantly, while around 40% of elderly adults have sleep-related complaints, sleep disorders are more frequently associated with co-morbidities including age-related neurodegenerative diseases and mild cognitive impairment. Recently, increasing evidence has indicated that disturbed sleep may not only serve as the consequence of brain atrophy, but also contribute to the pathogenesis of dementia and, therefore, significantly increase dementia risk. Since the current therapeutic interventions lack efficacies to prevent, delay or reverse the pathological progress of dementia, a better understanding of underlying mechanisms by which sleep disorders interact with the pathogenesis of dementia will provide possible targets for the prevention and treatment of dementia. In this review, we briefly describe the physiological roles of sleep in learning/memory, and specifically update the recent research evidence demonstrating the association between sleep disorders and dementia. Plausible mechanisms are further discussed. Moreover, we also evaluate the possibility of sleep therapy as a potential intervention for dementia.

Towards an explanation for the success of Acinetobacter baumannii in the human host

NARCIS (Netherlands)

Breij, Anastasia (Anna)

2012-01-01

Acinetobacter baumannii is an important nosocomial pathogen responsible for outbreaks of infection worldwide. The studies presented in this thesis aimed to gain further insight into the bacterial and host factors associated with the pathogenesis of A. baumannii to seek an explanation for the

An Upsurge in early childhood mortality in Kenya: A search for ...

African Journals Online (AJOL)

This study seeks to document recent trends in early childhood mortality in the country and to offer some plausible explanations for the upsurge in the trends. Data and information from various sources are used in this paper to achieve this purpose. The results obtained show that infant, child and under-five mortality rates had ...

The Class Size Question: A Study at Different Levels of Analysis. ACER Research Monograph No. 26.

Science.gov (United States)

Larkin, Anthony I.; Keeves, John P.

The purpose of this investigation was to examine the ways in which class size affected other facets of the educational environment of the classroom. The study focused on the commonly found positive relationship between class size and achievement. The most plausible explanation of the evidence seems to involve the effects of grouping more able…

Teachers' Knowledge Indices as Predictors of Secondary School Students' Academic Achievement in Kwara State, Nigeria

Science.gov (United States)

Olasehinde-Williams, Felicia; Yahaya, Lasiele; Owolabi, Henry

2018-01-01

That less than 40% of candidates who took the Senior School Certificate Examinations in Nigeria between 2009 and 2015 had credits and above in English language and Mathematics has become a source of worry to all stakeholders. Results of research efforts to provide plausible explanations to the problem have been inconclusive. Also, not much had…

Considerations of Elder Sibling Closeness in Predicting Younger Sibling Substance Use: Social Learning versus Social Bonding Explanations

Science.gov (United States)

Samek, Diana R.; Rueter, Martha A.

2011-01-01

Adolescent siblings are often similar in a variety of adjustment outcomes, yet little is known about the processes that explain sibling influences during adolescence. Two alternative explanations were tested, attachment (based in social bonding theory) and anaclitic identification (based in social learning theory). Hypotheses were tested using a sample of 613 adolescent sibling pairs (206 non-adopted, 407 adopted; elder sibling Mage = 16.1, younger sibling Mage = 13.8) across three sibling contexts (gender composition, age difference, and genetic similarity). Attachment explanations were supported such that the greater the perceived sibling emotional and behavioral closeness, the lower the likelihood of substance use; however, there were considerable moderating effects of sibling gender composition. Anaclitic identification explanations were not supported; closeness and elder sibling substance use did not interact to predict younger sibling substance use. Overall, this research adds to a body of work demonstrating important sibling influences on adolescent substance use. PMID:21988080

Attraction Basins as Gauges of Robustness against Boundary Conditions in Biological Complex Systems

Science.gov (United States)

Demongeot, Jacques; Goles, Eric; Morvan, Michel; Noual, Mathilde; Sené, Sylvain

2010-01-01

One fundamental concept in the context of biological systems on which researches have flourished in the past decade is that of the apparent robustness of these systems, i.e., their ability to resist to perturbations or constraints induced by external or boundary elements such as electromagnetic fields acting on neural networks, micro-RNAs acting on genetic networks and even hormone flows acting both on neural and genetic networks. Recent studies have shown the importance of addressing the question of the environmental robustness of biological networks such as neural and genetic networks. In some cases, external regulatory elements can be given a relevant formal representation by assimilating them to or modeling them by boundary conditions. This article presents a generic mathematical approach to understand the influence of boundary elements on the dynamics of regulation networks, considering their attraction basins as gauges of their robustness. The application of this method on a real genetic regulation network will point out a mathematical explanation of a biological phenomenon which has only been observed experimentally until now, namely the necessity of the presence of gibberellin for the flower of the plant Arabidopsis thaliana to develop normally. PMID:20700525

Attraction basins as gauges of robustness against boundary conditions in biological complex systems.

Directory of Open Access Journals (Sweden)

Jacques Demongeot

Full Text Available One fundamental concept in the context of biological systems on which researches have flourished in the past decade is that of the apparent robustness of these systems, i.e., their ability to resist to perturbations or constraints induced by external or boundary elements such as electromagnetic fields acting on neural networks, micro-RNAs acting on genetic networks and even hormone flows acting both on neural and genetic networks. Recent studies have shown the importance of addressing the question of the environmental robustness of biological networks such as neural and genetic networks. In some cases, external regulatory elements can be given a relevant formal representation by assimilating them to or modeling them by boundary conditions. This article presents a generic mathematical approach to understand the influence of boundary elements on the dynamics of regulation networks, considering their attraction basins as gauges of their robustness. The application of this method on a real genetic regulation network will point out a mathematical explanation of a biological phenomenon which has only been observed experimentally until now, namely the necessity of the presence of gibberellin for the flower of the plant Arabidopsis thaliana to develop normally.

Mechanisms of cold fusion: comprehensive explanations by the Nattoh model

International Nuclear Information System (INIS)

Matsumoto, Takaaki

1995-01-01

The phenomena of cold fusion seem to be very complicated; inconsistent data between the production rates of heat, neutrons, tritiums and heliums. Our thoughts need to drastically change in order to appropriately understand the mechanisms of cold fusion. Here, a review is described for the Nattoh model, that has been developed extensively to provide comprehensive explanations for the mechanisms of cold fusion. Important experimental findings that prove the model are described. Furthermore several subjects including impacts on other fields are also discussed. (author)

Energy Drinks and Myocardial Ischemia: A Review of Case Reports.

Science.gov (United States)

Lippi, Giuseppe; Cervellin, Gianfranco; Sanchis-Gomar, Fabian

2016-07-01

The use and abuse of energy drinks (EDs) is constantly increasing worldwide. We performed a systematic search in Medline, Scopus and Web of Science to identify evidence about the potential link between these beverages and myocardial ischemia. Overall, 8 case reports could be detected, all of which described a realistic association between large intake of EDs and episodes of myocardial ischemia. Interestingly, no additional triggers of myocardial ischemia other than energy drinks could be identified in the vast majority of cases. Some plausible explanations can be brought in support of this association. Most of the biological effects of EDs are seemingly mediated by a positive inotropic effect on cardiac function, which entails increase in heart rate, cardiac output and contractility, stroke volume and arterial blood pressure. Additional biological abnormalities reported after EDs intake include increased platelet aggregation, endothelial dysfunction, hyperglycemia as well as an increase in total cholesterol, triglycerides and low-density lipoprotein cholesterol. Although a causal relationship between large consumption of EDs and myocardial ischemia cannot be definitely established so far, concerns about the cardiovascular risk of excessive consumption of these beverages are seemingly justified.

The matchmaking paradox: a statistical explanation

International Nuclear Information System (INIS)

Eliazar, Iddo I; Sokolov, Igor M

2010-01-01

Medical surveys regarding the number of heterosexual partners per person yield different female and male averages-a result which, from a physical standpoint, is impossible. In this paper we term this puzzle the 'matchmaking paradox', and establish a statistical model explaining it. We consider a bipartite graph with N male and N female nodes (N >> 1), and B bonds connecting them (B >> 1). Each node is associated a random 'attractiveness level', and the bonds connect to the nodes randomly-with probabilities which are proportionate to the nodes' attractiveness levels. The population's average bonds-per-nodes B/N is estimated via a sample average calculated from a survey of size n (n >> 1). A comprehensive statistical analysis of this model is carried out, asserting that (i) the sample average well estimates the population average if and only if the attractiveness levels possess a finite mean; (ii) if the attractiveness levels are governed by a 'fat-tailed' probability law then the sample average displays wild fluctuations and strong skew-thus providing a statistical explanation to the matchmaking paradox.

Biological substantiation of antipsychotic-associated pneumonia: Systematic literature review and computational analyses.

Science.gov (United States)

Sultana, Janet; Calabró, Marco; Garcia-Serna, Ricard; Ferrajolo, Carmen; Crisafulli, Concetta; Mestres, Jordi; Trifirò', Gianluca

2017-01-01

Antipsychotic (AP) safety has been widely investigated. However, mechanisms underlying AP-associated pneumonia are not well-defined. The aim of this study was to investigate the known mechanisms of AP-associated pneumonia through a systematic literature review, confirm these mechanisms using an independent data source on drug targets and attempt to identify novel AP drug targets potentially linked to pneumonia. A search was conducted in Medline and Web of Science to identify studies exploring the association between pneumonia and antipsychotic use, from which information on hypothesized mechanism of action was extracted. All studies had to be in English and had to concern AP use as an intervention in persons of any age and for any indication, provided that the outcome was pneumonia. Information on the study design, population, exposure, outcome, risk estimate and mechanism of action was tabulated. Public repositories of pharmacology and drug safety data were used to identify the receptor binding profile and AP safety events. Cytoscape was then used to map biological pathways that could link AP targets and off-targets to pneumonia. The literature search yielded 200 articles; 41 were included in the review. Thirty studies reported a hypothesized mechanism of action, most commonly activation/inhibition of cholinergic, histaminergic and dopaminergic receptors. In vitro pharmacology data confirmed receptor affinities identified in the literature review. Two targets, thromboxane A2 receptor (TBXA2R) and platelet activating factor receptor (PTAFR) were found to be novel AP target receptors potentially associated with pneumonia. Biological pathways constructed using Cytoscape identified plausible biological links potentially leading to pneumonia downstream of TBXA2R and PTAFR. Innovative approaches for biological substantiation of drug-adverse event associations may strengthen evidence on drug safety profiles and help to tailor pharmacological therapies to patient risk

An explanation for the shape of nanoindentation unloading curves based on finite element simulation

International Nuclear Information System (INIS)

Bolshakov, A.; Pharr, G.M.

1995-01-01

Current methods for measuring hardness and modulus from nanoindentation load-displacement data are based on Sneddon's equations for the indentation of an elastic half-space by an axially symmetric rigid punch. Recent experiments have shown that nanoindentation unloading data are distinctly curved in a manner which is not consistent with either the flat punch or the conical indenter geometries frequently used in modeling, but are more closely approximated by a parabola of revolution. Finite element simulations for conical indentation of an elastic-plastic material are presented which corroborate the experimental observations, and from which a simple explanation for the shape of the unloading curve is derived. The explanation is based on the concept of an effective indenter shape whose geometry is determined by the shape of the plastic hardness impression formed during indentation

Students' Affordance of Teleologic Explanations and Anthropomorphic Language in Eliciting Concepts in Physics

Science.gov (United States)

Bautista, Romiro G.

2015-01-01

This study ascertains that the students' affordance of teleologic explanations and anthropomorphic language in eliciting concepts in Physics is influenced by their age and learning exposure and experience. Using Explicative-Reductive Method of Descriptive Research, this study focused on the determinants of students' affordance of…

Function of dynamic models in systems biology: linking structure to behaviour.

Science.gov (United States)

Knüpfer, Christian; Beckstein, Clemens

2013-10-08

Dynamic models in Systems Biology are used in computational simulation experiments for addressing biological questions. The complexity of the modelled biological systems and the growing number and size of the models calls for computer support for modelling and simulation in Systems Biology. This computer support has to be based on formal representations of relevant knowledge fragments. In this paper we describe different functional aspects of dynamic models. This description is conceptually embedded in our "meaning facets" framework which systematises the interpretation of dynamic models in structural, functional and behavioural facets. Here we focus on how function links the structure and the behaviour of a model. Models play a specific role (teleological function) in the scientific process of finding explanations for dynamic phenomena. In order to fulfil this role a model has to be used in simulation experiments (pragmatical function). A simulation experiment always refers to a specific situation and a state of the model and the modelled system (conditional function). We claim that the function of dynamic models refers to both the simulation experiment executed by software (intrinsic function) and the biological experiment which produces the phenomena under investigation (extrinsic function). We use the presented conceptual framework for the function of dynamic models to review formal accounts for functional aspects of models in Systems Biology, such as checklists, ontologies, and formal languages. Furthermore, we identify missing formal accounts for some of the functional aspects. In order to fill one of these gaps we propose an ontology for the teleological function of models. We have thoroughly analysed the role and use of models in Systems Biology. The resulting conceptual framework for the function of models is an important first step towards a comprehensive formal representation of the functional knowledge involved in the modelling and simulation process

Developing computer-based training programs for basic mammalian histology: Didactic versus discovery-based design

Science.gov (United States)

Fabian, Henry Joel

Educators have long tried to understand what stimulates students to learn. The Swiss psychologist and zoologist, Jean Claude Piaget, suggested that students are stimulated to learn when they attempt to resolve confusion. He reasoned that students try to explain the world with the knowledge they have acquired in life. When they find their own explanations to be inadequate to explain phenomena, students find themselves in a temporary state of confusion. This prompts students to seek more plausible explanations. At this point, students are primed for learning (Piaget 1964). The Piagetian approach described above is called learning by discovery. To promote discovery learning, a teacher must first allow the student to recognize his misconception and then provide a plausible explanation to replace that misconception (Chinn and Brewer 1993). One application of this method is found in the various learning cycles, which have been demonstrated to be effective means for teaching science (Renner and Lawson 1973, Lawson 1986, Marek and Methven 1991, and Glasson & Lalik 1993). In contrast to the learning cycle, tutorial computer programs are generally not designed to correct student misconceptions, but rather follow a passive, didactic method of teaching. In the didactic or expositional method, the student is told about a phenomenon, but is neither encouraged to explore it, nor explain it in his own terms (Schneider and Renner 1980).

Polarization and Persuasion: Integrating the Elaboration Likelihood Model with Explanations of Group Polarization.

Science.gov (United States)

Mongeau, Paul A.

Interest has recently focused on group polarization as a function of attitude processes. Several recent reviewers have challenged polarization researchers to integrate the explanations of polarization to existing theories of attitude change. This review suggests that there exists a clear similarity between the social comparison and persuasive…

Bayesianism and inference to the best explanation

Directory of Open Access Journals (Sweden)

Valeriano IRANZO

2008-01-01

Full Text Available Bayesianism and Inference to the best explanation (IBE are two different models of inference. Recently there has been some debate about the possibility of “bayesianizing” IBE. Firstly I explore several alternatives to include explanatory considerations in Bayes’s Theorem. Then I distinguish two different interpretations of prior probabilities: “IBE-Bayesianism” (IBE-Bay and “frequentist-Bayesianism” (Freq-Bay. After detailing the content of the latter, I propose a rule for assessing the priors. I also argue that Freq-Bay: (i endorses a role for explanatory value in the assessment of scientific hypotheses; (ii avoids a purely subjectivist reading of prior probabilities; and (iii fits better than IBE-Bayesianism with two basic facts about science, i.e., the prominent role played by empirical testing and the existence of many scientific theories in the past that failed to fulfil their promises and were subsequently abandoned.

Understanding schizophrenia as a disorder of consciousness: biological correlates and translational implications from quantum theory perspectives.

Science.gov (United States)

Venkatasubramanian, Ganesan

2015-04-30

From neurophenomenological perspectives, schizophrenia has been conceptualized as "a disorder with heterogeneous manifestations that can be integrally understood to involve fundamental perturbations in consciousness". While these theoretical constructs based on consciousness facilitate understanding the 'gestalt' of schizophrenia, systematic research to unravel translational implications of these models is warranted. To address this, one needs to begin with exploration of plausible biological underpinnings of "perturbed consciousness" in schizophrenia. In this context, an attractive proposition to understand the biology of consciousness is "the orchestrated object reduction (Orch-OR) theory" which invokes quantum processes in the microtubules of neurons. The Orch-OR model is particularly important for understanding schizophrenia especially due to the shared 'scaffold' of microtubules. The initial sections of this review focus on the compelling evidence to support the view that "schizophrenia is a disorder of consciousness" through critical summary of the studies that have demonstrated self-abnormalities, aberrant time perception as well as dysfunctional intentional binding in this disorder. Subsequently, these findings are linked with 'Orch-OR theory' through the research evidence for aberrant neural oscillations as well as microtubule abnormalities observed in schizophrenia. Further sections emphasize the applicability and translational implications of Orch-OR theory in the context of schizophrenia and elucidate the relevance of quantum biology to understand the origins of this puzzling disorder as "fundamental disturbances in consciousness".

Large-scale association analyses identify new loci influencing glycemic traits and provide insight into the underlying biological pathways

Science.gov (United States)

Scott, Robert A; Lagou, Vasiliki; Welch, Ryan P; Wheeler, Eleanor; Montasser, May E; Luan, Jian’an; Mägi, Reedik; Strawbridge, Rona J; Rehnberg, Emil; Gustafsson, Stefan; Kanoni, Stavroula; Rasmussen-Torvik, Laura J; Yengo, Loïc; Lecoeur, Cecile; Shungin, Dmitry; Sanna, Serena; Sidore, Carlo; Johnson, Paul C D; Jukema, J Wouter; Johnson, Toby; Mahajan, Anubha; Verweij, Niek; Thorleifsson, Gudmar; Hottenga, Jouke-Jan; Shah, Sonia; Smith, Albert V; Sennblad, Bengt; Gieger, Christian; Salo, Perttu; Perola, Markus; Timpson, Nicholas J; Evans, David M; Pourcain, Beate St; Wu, Ying; Andrews, Jeanette S; Hui, Jennie; Bielak, Lawrence F; Zhao, Wei; Horikoshi, Momoko; Navarro, Pau; Isaacs, Aaron; O’Connell, Jeffrey R; Stirrups, Kathleen; Vitart, Veronique; Hayward, Caroline; Esko, Tönu; Mihailov, Evelin; Fraser, Ross M; Fall, Tove; Voight, Benjamin F; Raychaudhuri, Soumya; Chen, Han; Lindgren, Cecilia M; Morris, Andrew P; Rayner, Nigel W; Robertson, Neil; Rybin, Denis; Liu, Ching-Ti; Beckmann, Jacques S; Willems, Sara M; Chines, Peter S; Jackson, Anne U; Kang, Hyun Min; Stringham, Heather M; Song, Kijoung; Tanaka, Toshiko; Peden, John F; Goel, Anuj; Hicks, Andrew A; An, Ping; Müller-Nurasyid, Martina; Franco-Cereceda, Anders; Folkersen, Lasse; Marullo, Letizia; Jansen, Hanneke; Oldehinkel, Albertine J; Bruinenberg, Marcel; Pankow, James S; North, Kari E; Forouhi, Nita G; Loos, Ruth J F; Edkins, Sarah; Varga, Tibor V; Hallmans, Göran; Oksa, Heikki; Antonella, Mulas; Nagaraja, Ramaiah; Trompet, Stella; Ford, Ian; Bakker, Stephan J L; Kong, Augustine; Kumari, Meena; Gigante, Bruna; Herder, Christian; Munroe, Patricia B; Caulfield, Mark; Antti, Jula; Mangino, Massimo; Small, Kerrin; Miljkovic, Iva; Liu, Yongmei; Atalay, Mustafa; Kiess, Wieland; James, Alan L; Rivadeneira, Fernando; Uitterlinden, Andre G; Palmer, Colin N A; Doney, Alex S F; Willemsen, Gonneke; Smit, Johannes H; Campbell, Susan; Polasek, Ozren; Bonnycastle, Lori L; Hercberg, Serge; Dimitriou, Maria; Bolton, Jennifer L; Fowkes, Gerard R; Kovacs, Peter; Lindström, Jaana; Zemunik, Tatijana; Bandinelli, Stefania; Wild, Sarah H; Basart, Hanneke V; Rathmann, Wolfgang; Grallert, Harald; Maerz, Winfried; Kleber, Marcus E; Boehm, Bernhard O; Peters, Annette; Pramstaller, Peter P; Province, Michael A; Borecki, Ingrid B; Hastie, Nicholas D; Rudan, Igor; Campbell, Harry; Watkins, Hugh; Farrall, Martin; Stumvoll, Michael; Ferrucci, Luigi; Waterworth, Dawn M; Bergman, Richard N; Collins, Francis S; Tuomilehto, Jaakko; Watanabe, Richard M; de Geus, Eco J C; Penninx, Brenda W; Hofman, Albert; Oostra, Ben A; Psaty, Bruce M; Vollenweider, Peter; Wilson, James F; Wright, Alan F; Hovingh, G Kees; Metspalu, Andres; Uusitupa, Matti; Magnusson, Patrik K E; Kyvik, Kirsten O; Kaprio, Jaakko; Price, Jackie F; Dedoussis, George V; Deloukas, Panos; Meneton, Pierre; Lind, Lars; Boehnke, Michael; Shuldiner, Alan R; van Duijn, Cornelia M; Morris, Andrew D; Toenjes, Anke; Peyser, Patricia A; Beilby, John P; Körner, Antje; Kuusisto, Johanna; Laakso, Markku; Bornstein, Stefan R; Schwarz, Peter E H; Lakka, Timo A; Rauramaa, Rainer; Adair, Linda S; Smith, George Davey; Spector, Tim D; Illig, Thomas; de Faire, Ulf; Hamsten, Anders; Gudnason, Vilmundur; Kivimaki, Mika; Hingorani, Aroon; Keinanen-Kiukaanniemi, Sirkka M; Saaristo, Timo E; Boomsma, Dorret I; Stefansson, Kari; van der Harst, Pim; Dupuis, Josée; Pedersen, Nancy L; Sattar, Naveed; Harris, Tamara B; Cucca, Francesco; Ripatti, Samuli; Salomaa, Veikko; Mohlke, Karen L; Balkau, Beverley; Froguel, Philippe; Pouta, Anneli; Jarvelin, Marjo-Riitta; Wareham, Nicholas J; Bouatia-Naji, Nabila; McCarthy, Mark I; Franks, Paul W; Meigs, James B; Teslovich, Tanya M; Florez, Jose C; Langenberg, Claudia; Ingelsson, Erik; Prokopenko, Inga; Barroso, Inês

2012-01-01

Through genome-wide association meta-analyses of up to 133,010 individuals of European ancestry without diabetes, including individuals newly genotyped using the Metabochip, we have raised the number of confirmed loci influencing glycemic traits to 53, of which 33 also increase type 2 diabetes risk (q fasting insulin showed association with lipid levels and fat distribution, suggesting impact on insulin resistance. Gene-based analyses identified further biologically plausible loci, suggesting that additional loci beyond those reaching genome-wide significance are likely to represent real associations. This conclusion is supported by an excess of directionally consistent and nominally significant signals between discovery and follow-up studies. Functional follow-up of these newly discovered loci will further improve our understanding of glycemic control. PMID:22885924

The Linguistic Market for English in Bangladesh

Science.gov (United States)

Hamid, M. Obaidul

2016-01-01

A large body of work has investigated the presence of English and its teaching and learning in the developing world where English is used as a second/foreign language. While this work has provided plausible explanations for the global spread of English as well as its uptake by education policy-makers and communities, there has been limited…

Patterns of left ventricular geometry and the transition to congestive heart failure with preserved versus depressed ejection fraction (Patrones de geometría ventricular izquierda y la transición a la insuficiencia cardíaca congestiva con fracción de eyección conservada versus deprimida)

OpenAIRE

José H. Donis Hernández; Francisco Sanchez; Bárbara das Neves; Carmen A. Mazzei de Dávila, Lisett Aranguibel, Maite González; Lisett Aranguibel; Maite González

2014-01-01

Abstract (english) Analysis of cross-sectional and follow up clinical studies, of hypertensive patients with the different left ventricular geometric patterns, provide plausible explanations for the transition from hypertensive heart disease to the two distinct phenotypes of systolic and diastolic congestive heart failure. According to the LIFE study treated-uncomplicated patients, with normal ventricular geometry (12%), concentric remodeling ...

Does the inherence heuristic take us to psychological essentialism?

Science.gov (United States)

Marmodoro, Anna; Murphy, Robin A; Baker, A G

2014-10-01

We argue that the claim that essence-based causal explanations emerge, hydra-like, from an inherence heuristic is incomplete. No plausible mechanism for the transition from concrete properties, or cues, to essences is provided. Moreover, the fundamental shotgun and storytelling mechanisms of the inherence heuristic are not clearly enough specified to distinguish them, developmentally, from associative or causal networks.

Invisible-hand explanations: From blindness to lack of we-ness

OpenAIRE

Dayer-Tieffenbach, Emma

2013-01-01

The unintendedness of the phenomenon that is to be explained is a constraint visible in the various applications and clarifications of invisible hand explanations. The article casts doubt on such a requirement and proposes a revised account. To have a role in an invisible hand process it is argued agents may very well act with a view to contributing to the occurrence of the social outcome that is to be explained provided they see what they do as an aggregation of their individual actions rath...

Non-Western students' causal reasoning about biologically adaptive changes in humans, other animals and plants: instructional and curricular implications

Science.gov (United States)

Mbajiorgu, Ngozika; Anidu, Innocent

2017-06-01

Senior secondary school students (N = 360), 14- to 18-year-olds, from the Igbo culture of eastern Nigeria responded to a questionnaire requiring them to give causal explanations of biologically adaptive changes in humans, other animals and plants. A student subsample (n = 36) was, subsequently, selected for in-depth interviews. Significant differences were found between prompts within the prompt categories, suggesting item feature effects. However, the most coherent pattern was found within the plant category as patterns differed for the mechanistic proximate (MP) reasoning category only. Patterns also differed highly significantly between the prompt categories, with patterns for teleology, MP, mechanistic ultimate and don't know categories similar for plants and other animals but different for the human category. Both urban and rural students recognise commonalities in causality between the three prompt categories, in that their preferences for causal explanations were similar across four reasoning categories. The rural students, however, were more likely than their urban counterparts to give multiple causal explanations in the span of a single response and less likely to attribute causal agency to God. Two factors, religious belief and language, for all the students; and one factor, ecological closeness to nature, for rural students were suspected to have produced these patterns.

Examining explanations for fundamental frequency's contribution to speech intelligibility in noise

Science.gov (United States)

Schlauch, Robert S.; Miller, Sharon E.; Watson, Peter J.

2005-09-01

Laures and Weismer [JSLHR, 42, 1148 (1999)] reported that speech with natural variation in fundamental frequency (F0) is more intelligible in noise than speech with a flattened F0 contour. Cognitive-linguistic based explanations have been offered to account for this drop in intelligibility for the flattened condition, but a lower-level mechanism related to auditory streaming may be responsible. Numerous psychoacoustic studies have demonstrated that modulating a tone enables a listener to segregate it from background sounds. To test these rival hypotheses, speech recognition in noise was measured for sentences with six different F0 contours: unmodified, flattened at the mean, natural but exaggerated, reversed, and frequency modulated (rates of 2.5 and 5.0 Hz). The 180 stimulus sentences were produced by five talkers (30 sentences per condition). Speech recognition for fifteen listeners replicate earlier findings showing that flattening the F0 contour results in a roughly 10% reduction in recognition of key words compared with the natural condition. Although the exaggerated condition produced results comparable to those of the flattened condition, the other conditions with unnatural F0 contours all yielded significantly poorer performance than the flattened condition. These results support the cognitive, linguistic-based explanations for the reduction in performance.

Long-term biological effects induced by ionizing radiation--implications for dose mediated risk.

Science.gov (United States)

Miron, S D; Astărăstoae, V

2014-01-01

Ionizing radiations are considered to be risk agents that are responsible for the effects on interaction with living matter. The occurring biological effects are due to various factors such as: dose, type of radiation, exposure time, type of biological tissue, health condition and the age of the person exposed. The mechanisms involved in the direct modifications of nuclear DNA and mitochondrial DNA are reviewed. Classical target theory of energy deposition in the nucleus that causes DNA damages, in particular DNA double-strand breaks and that explanation of the biological consequences of ionizing radiation exposure is a paradigm in radiobiology. Recent experimental evidences have demonstrated the existence of a molecular mechanism that explains the non-targeted effects of ionizing radiation exposure. Among these novel data, genomic instability and a variety of bystander effects are discussed here. Those bystander effects of ionizing radiation are fulfilled by cellular communication systems that give rise to non-targeted effects in the neighboring non irradiated cells. This paper provides also a commentary on the synergistic effects induced by the co-exposures to ionizing radiation and various physical agents such as electromagnetic fields and the co-exposures to ionizing radiation and chemical environmental contaminants such as metals. The biological effects of multiple stressors on genomic instability and bystander effects are also discussed. Moreover, a brief presentation of the methods used to characterize cyto- and genotoxic damages is offered.

Examining the Effects of Two Computer Programming Learning Strategies: Self-Explanation versus Reading Questions and Answers

Directory of Open Access Journals (Sweden)

Nancy Lee

2017-08-01

Full Text Available The study described here explored the differential effects of two learning strategies, self-explanation and reading questions and answers, on learning the computer programming language JavaScript. Students’ test performance and perceptions of effectiveness toward the two strategies were examined. An online interactive tutorial instruction implementing worked-examples and multimedia learning principles was developed for this study. Participants were 147 high school students (ages 14 to 18 of a computer introductory course in six periods which were randomly divided into two groups (n = 78; n = 69 of three periods each. The two groups alternated learning strategies to learn five lessons. Students’ prerequisite knowledge of XHTML and motivation to learn computer programming languages were measured before starting the tutorial. Students largely expressed their preference toward self-explanation over reading questions and answers. They thought self-explanation incurred much more work yet was more effective. However, the two learning strategies did not have differential effects on students’ test performance. The seeming discrepancy arising from students’ preferred strategy and their test performance was discussed in the areas of familiar versus new strategy, difficulty of learning materials and testing method, and experimental duration.

14 CFR 221.200 - Content and explanation of abbreviations, reference marks and symbols.

Science.gov (United States)

2010-01-01

..., reference marks and symbols. 221.200 Section 221.200 Aeronautics and Space OFFICE OF THE SECRETARY... § 221.200 Content and explanation of abbreviations, reference marks and symbols. (a) Content. The format..., reference marks and symbols. Abbreviations, reference marks and symbols which are used in the tariff shall...

Institutional and Demographic Explanations of Women's Employment in 18 OECD Countries, 1975-1999

Science.gov (United States)

Nieuwenhuis, Rense; Need, Ariana; Van Der Kolk, Henk

2012-01-01

This study combined demographic and institutional explanations of women's employment, describing and explaining the degree to which mothers in industrialized societies are less likely to be employed than women without children. A large number of cross-sectional surveys were pooled, covering 18 Organisation for Economic Co-Operation and Development…

The evidence for biologic immunotherapy in Sarcoidosis: A systematic review

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Pooja Shah

2017-09-01

Full Text Available Background Sarcoidosis is a chronic inflammatory disease with a myriad of clinical manifestations. Treatment involves immunosuppression with corticosteroids or steroid-sparing agents. A proportion of patients does not respond to or are intolerant to therapy. Targeted immunotherapy with biologic agents has emerged as a novel approach with plausible mechanistic reasons to warrant study. Aims The aim of this review was to evaluate the evidence for the efficacy of biological therapy in sarcoidosis. Methods We conducted a systematic literature review and meta-analysis of all published randomised-controlled trials (RCT evaluating biological therapy in sarcoidosis, using MEDLINE and Embase databases, through to September 2017. The search terms included sarcoidosis, infliximab, adalimumab, etanercept, golimumab, certolizumab, rituximab, abatacept, tocilizumab, anakinra, ustekinumab, secukinumab. Only articles reporting RCTs were selected. Improvements in respiratory disease were assessed by changes in forced vital capacity (FVC by weighted mean difference (WMD. There were insufficient data on outcome measures in other organ systems to comparatively assess efficacy. Results The search identified 2,324 studies of which only 5 provided relevant and original data. This comprised a total of 364 patients, evaluating pulmonary, cutaneous and ocular sarcoidosis. One study in pulmonary disease and one study in cutaneous disease demonstrated improvements in the primary outcome. In pulmonary disease, meta-analysis of the treatment effect of anti-TNF therapy versus placebo on FVC revealed a WMD of 1.69 per cent (95 per cent confidence interval, 1.44–1.94. Conclusion There are insufficient data to suggest the long-term efficacy of anti-TNFα inhibitors in the treatment of sarcoidosis. This may be due to heterogeneity, small sample sizes and the lack of consistent reporting of outcome measures.

Using Variable Precision Rough Set for Selection and Classification of Biological Knowledge Integrated in DNA Gene Expression

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Calvo-Dmgz D.

2012-12-01

Full Text Available DNA microarrays have contributed to the exponential growth of genomic and experimental data in the last decade. This large amount of gene expression data has been used by researchers seeking diagnosis of diseases like cancer using machine learning methods. In turn, explicit biological knowledge about gene functions has also grown tremendously over the last decade. This work integrates explicit biological knowledge, provided as gene sets, into the classication process by means of Variable Precision Rough Set Theory (VPRS. The proposed model is able to highlight which part of the provided biological knowledge has been important for classification. This paper presents a novel model for microarray data classification which is able to incorporate prior biological knowledge in the form of gene sets. Based on this knowledge, we transform the input microarray data into supergenes, and then we apply rough set theory to select the most promising supergenes and to derive a set of easy interpretable classification rules. The proposed model is evaluated over three breast cancer microarrays datasets obtaining successful results compared to classical classification techniques. The experimental results shows that there are not significat differences between our model and classical techniques but it is able to provide a biological-interpretable explanation of how it classifies new samples.