WorldWideScience

Sample records for plausible biological explanations

  1. Turing patterns and biological explanation

    DEFF Research Database (Denmark)

    Serban, Maria

    2017-01-01

    , promoting theory exploration, and acting as constitutive parts of empirically adequate explanations of naturally occurring phenomena, such as biological pattern formation. Focusing on the roles that minimal model explanations play in science motivates the adoption of a broader diachronic view of scientific......Turing patterns are a class of minimal mathematical models that have been used to discover and conceptualize certain abstract features of early biological development. This paper examines a range of these minimal models in order to articulate and elaborate a philosophical analysis...

  2. 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...

  3. Evaporative water loss is a plausible explanation for mortality of bats from white-nose syndrome.

    Science.gov (United States)

    Willis, Craig K R; Menzies, Allyson K; Boyles, Justin G; Wojciechowski, Michal S

    2011-09-01

    White-nose syndrome (WNS) has caused alarming declines of North American bat populations in the 5 years since its discovery. Affected bats appear to starve during hibernation, possibly because of disruption of normal cycles of torpor and arousal. The importance of hydration state and evaporative water loss (EWL) for influencing the duration of torpor bouts in hibernating mammals recently led to "the dehydration hypothesis," that cutaneous infection of the wing membranes of bats with the fungus Geomyces destructans causes dehydration which in turn, increases arousal frequency during hibernation. This hypothesis predicts that uninfected individuals of species most susceptible to WNS, like little brown bats (Myotis lucifugus), exhibit high rates of EWL compared to less susceptible species. We tested the feasibility of this prediction using data from the literature and new data quantifying EWL in Natterer's bats (Myotis nattereri), a species that is, like other European bats, sympatric with G. destructans but does not appear to suffer significant mortality from WNS. We found that little brown bats exhibited significantly higher rates of normothermic EWL than did other bat species for which comparable EWL data are available. We also found that Natterer's bats exhibited significantly lower rates of EWL, in both wet and dry air, compared with values predicted for little brown bats exposed to identical relative humidity (RH). We used a population model to show that the increase in EWL required to cause the pattern of mortality observed for WNS-affected little brown bats was small, equivalent to a solitary bat hibernating exposed to RH of ∼95%, or clusters hibernating in ∼87% RH, as opposed to typical near-saturation conditions. Both of these results suggest the dehydration hypothesis is plausible and worth pursuing as a possible explanation for mortality of bats from WNS.

  4. On the biological plausibility of Wind Turbine Syndrome.

    Science.gov (United States)

    Harrison, Robert V

    2015-01-01

    An emerging environmental health issue relates to potential ill-effects of wind turbine noise. There have been numerous suggestions that the low-frequency acoustic components in wind turbine signals can cause symptoms associated with vestibular system disorders, namely vertigo, nausea, and nystagmus. This constellation of symptoms has been labeled as Wind Turbine Syndrome, and has been identified in case studies of individuals living close to wind farms. This review discusses whether it is biologically plausible for the turbine noise to stimulate the vestibular parts of the inner ear and, by extension, cause Wind Turbine Syndrome. We consider the sound levels that can activate the semicircular canals or otolith end organs in normal subjects, as well as in those with preexisting conditions known to lower vestibular threshold to sound stimulation.

  5. Generative Mechanistic Explanation Building in Undergraduate Molecular and Cellular Biology

    Science.gov (United States)

    Southard, Katelyn M.; Espindola, Melissa R.; Zaepfel, Samantha D.; Bolger, Molly S.

    2017-01-01

    When conducting scientific research, experts in molecular and cellular biology (MCB) use specific reasoning strategies to construct mechanistic explanations for the underlying causal features of molecular phenomena. We explored how undergraduate students applied this scientific practice in MCB. Drawing from studies of explanation building among…

  6. Epidemiologic studies of occupational pesticide exposure and cancer: regulatory risk assessments and biologic plausibility.

    Science.gov (United States)

    Acquavella, John; Doe, John; Tomenson, John; Chester, Graham; Cowell, John; Bloemen, Louis

    2003-01-01

    Epidemiologic studies frequently show associations between self-reported use of specific pesticides and human cancers. These findings have engendered debate largely on methodologic grounds. However, biologic plausibility is a more fundamental issue that has received only superficial attention. The purpose of this commentary is to review briefly the toxicology and exposure data that are developed as part of the pesticide regulatory process and to discuss the applicability of this data to epidemiologic research. The authors also provide a generic example of how worker pesticide exposures might be estimated and compared to relevant toxicologic dose levels. This example provides guidance for better characterization of exposure and for consideration of biologic plausibility in epidemiologic studies of pesticides.

  7. Generative mechanistic explanation building in undergraduate molecular and cellular biology

    Science.gov (United States)

    Southard, Katelyn M.; Espindola, Melissa R.; Zaepfel, Samantha D.; Bolger, Molly S.

    2017-09-01

    When conducting scientific research, experts in molecular and cellular biology (MCB) use specific reasoning strategies to construct mechanistic explanations for the underlying causal features of molecular phenomena. We explored how undergraduate students applied this scientific practice in MCB. Drawing from studies of explanation building among scientists, we created and applied a theoretical framework to explore the strategies students use to construct explanations for 'novel' biological phenomena. Specifically, we explored how students navigated the multi-level nature of complex biological systems using generative mechanistic reasoning. Interviews were conducted with introductory and upper-division biology students at a large public university in the United States. Results of qualitative coding revealed key features of students' explanation building. Students used modular thinking to consider the functional subdivisions of the system, which they 'filled in' to varying degrees with mechanistic elements. They also hypothesised the involvement of mechanistic entities and instantiated abstract schema to adapt their explanations to unfamiliar biological contexts. Finally, we explored the flexible thinking that students used to hypothesise the impact of mutations on multi-leveled biological systems. Results revealed a number of ways that students drew mechanistic connections between molecules, functional modules (sets of molecules with an emergent function), cells, tissues, organisms and populations.

  8. A swarm intelligence framework for reconstructing gene networks: searching for biologically plausible architectures.

    Science.gov (United States)

    Kentzoglanakis, Kyriakos; Poole, Matthew

    2012-01-01

    In this paper, we investigate the problem of reverse engineering the topology of gene regulatory networks from temporal gene expression data. We adopt a computational intelligence approach comprising swarm intelligence techniques, namely particle swarm optimization (PSO) and ant colony optimization (ACO). In addition, the recurrent neural network (RNN) formalism is employed for modeling the dynamical behavior of gene regulatory systems. More specifically, ACO is used for searching the discrete space of network architectures and PSO for searching the corresponding continuous space of RNN model parameters. We propose a novel solution construction process in the context of ACO for generating biologically plausible candidate architectures. The objective is to concentrate the search effort into areas of the structure space that contain architectures which are feasible in terms of their topological resemblance to real-world networks. The proposed framework is initially applied to the reconstruction of a small artificial network that has previously been studied in the context of gene network reverse engineering. Subsequently, we consider an artificial data set with added noise for reconstructing a subnetwork of the genetic interaction network of S. cerevisiae (yeast). Finally, the framework is applied to a real-world data set for reverse engineering the SOS response system of the bacterium Escherichia coli. Results demonstrate the relative advantage of utilizing problem-specific knowledge regarding biologically plausible structural properties of gene networks over conducting a problem-agnostic search in the vast space of network architectures.

  9. Particulate air pollution and increased mortality: Biological plausibility for causal relationship

    International Nuclear Information System (INIS)

    Henderson, R.F.

    1995-01-01

    Recently, a number of epidemiological studies have concluded that ambient particulate exposure is associated with increased mortality and morbidity at PM concentrations well below those previously thought to affect human health. These studies have been conducted in several different geographical locations and have involved a range of populations. While the consistency of the findings and the presence of an apparent concentration response relationship provide a strong argument for causality, epidemiological studies can only conclude this based upon inference from statistical associations. The biological plausibility of a causal relationship between low concentrations of PM and daily mortality and morbidity rates is neither intuitively obvious nor expected based on past experimental studies on the toxicity of inhaled particles. Chronic toxicity from inhaled, poorly soluble particles has been observed based on the slow accumulation of large lung burdens of particles, not on small daily fluctuations in PM levels. Acute toxicity from inhaled particles is associated mainly with acidic particles and is observed at much higher concentrations than those observed in the epidemiology studies reporting an association between PM concentrations and morbidity/mortality. To approach the difficult problem of determining if the association between PM concentrations and daily morbidity and mortality is biologically plausible and causal, one must consider (1) the chemical and physical characteristics of the particles in the inhaled atmospheres, (2) the characteristics of the morbidity/mortality observed and the people who are affected, and (3) potential mechanisms that might link the two

  10. Biologically plausible learning in neural networks: a lesson from bacterial chemotaxis.

    Science.gov (United States)

    Shimansky, Yury P

    2009-12-01

    Learning processes in the brain are usually associated with plastic changes made to optimize the strength of connections between neurons. Although many details related to biophysical mechanisms of synaptic plasticity have been discovered, it is unclear how the concurrent performance of adaptive modifications in a huge number of spatial locations is organized to minimize a given objective function. Since direct experimental observation of even a relatively small subset of such changes is not feasible, computational modeling is an indispensable investigation tool for solving this problem. However, the conventional method of error back-propagation (EBP) employed for optimizing synaptic weights in artificial neural networks is not biologically plausible. This study based on computational experiments demonstrated that such optimization can be performed rather efficiently using the same general method that bacteria employ for moving closer to an attractant or away from a repellent. With regard to neural network optimization, this method consists of regulating the probability of an abrupt change in the direction of synaptic weight modification according to the temporal gradient of the objective function. Neural networks utilizing this method (regulation of modification probability, RMP) can be viewed as analogous to swimming in the multidimensional space of their parameters in the flow of biochemical agents carrying information about the optimality criterion. The efficiency of RMP is comparable to that of EBP, while RMP has several important advantages. Since the biological plausibility of RMP is beyond a reasonable doubt, the RMP concept provides a constructive framework for the experimental analysis of learning in natural neural networks.

  11. Photoinduced catalytic synthesis of biologically important metabolites from formaldehyde and ammonia under plausible "prebiotic" conditions

    Science.gov (United States)

    Delidovich, I. V.; Taran, O. P.; Simonov, A. N.; Matvienko, L. G.; Parmon, V. N.

    2011-08-01

    The article analyzes new and previously reported data on several catalytic and photochemical processes yielding biologically important molecules. UV-irradiation of formaldehyde aqueous solution yields acetaldehyde, glyoxal, glycolaldehyde and glyceraldehyde, which can serve as precursors of more complex biochemically relevant compounds. Photolysis of aqueous solution of acetaldehyde and ammonium nitrate results in formation of alanine and pyruvic acid. Dehydration of glyceraldehyde catalyzed by zeolite HZSM-5-17 yields pyruvaldehyde. Monosaccharides are formed in the course of the phosphate-catalyzed aldol condensation reactions of glycolaldehyde, glyceraldehyde and formaldehyde. The possibility of the direct synthesis of tetroses, keto- and aldo-pentoses from pure formaldehyde due to the combination of the photochemical production of glycolahyde and phosphate-catalyzed carbohydrate chain growth is demonstrated. Erythrulose and 3-pentulose are the main products of such combined synthesis with selectivity up to 10%. Biologically relevant aldotetroses, aldo- and ketopentoses are more resistant to the photochemical destruction owing to the stabilization in hemiacetal cyclic forms. They are formed as products of isomerization of erythrulose and 3-pentulose. The conjugation of the concerned reactions results in a plausible route to the formation of sugars, amino and organic acids from formaldehyde and ammonia under presumed 'prebiotic' conditions.

  12. Synthetic biology: a challenge to mechanical explanations in biology?

    Science.gov (United States)

    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.

  13. Development of biological and nonbiological explanations for the Viking label release data. [hydrogen peroxide theory

    Science.gov (United States)

    1980-01-01

    The plausibility that hydrogen peroxide, widely distributed within the Mars surface material, was responsible for the evocative response obtained by the Viking Labeled Release (LR) experiment on Mars was investigated. Although a mixture of gamma Fe2O3 and silica sand stimulated the LR nutrient reaction with hydrogen peroxide and reduced the rate of hydrogen decomposition under various storage conditions, the Mars analog soil prepared by the Viking Inorganic Analysis Team to match the Mars analytical data does not cause such effects. Nor is adequate resistance to UV irradiation shown. On the basis of the results and consideration presented while the hydrogen peroxide theory remains the most, if not only, attractive chemical explanation of the LR data, it remains unconvincing on critical points. Until problems concerning the formation and stabilization of hydrogen peroxide on the surface of Mars can be overcome, adhere to the scientific evidence requires serious consideration of the biological theory.

  14. Antimicrobial resistance and biological governance: explanations for policy failure.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  17. Gene-ontology enrichment analysis in two independent family-based samples highlights biologically plausible processes for autism spectrum disorders.

    LENUS (Irish Health Repository)

    Anney, Richard J L

    2012-02-01

    Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biological pathways in the aetiology of autism. However, despite the strong influence of genetic factors, association studies have yet to identify statistically robust, replicated major effect genes or SNPs. We apply the principle of the SNP ratio test methodology described by O\\'Dushlaine et al to over 2100 families from the Autism Genome Project (AGP). Using a two-stage design we examine association enrichment in 5955 unique gene-ontology classifications across four groupings based on two phenotypic and two ancestral classifications. Based on estimates from simulation we identify excess of association enrichment across all analyses. We observe enrichment in association for sets of genes involved in diverse biological processes, including pyruvate metabolism, transcription factor activation, cell-signalling and cell-cycle regulation. Both genes and processes that show enrichment have previously been examined in autistic disorders and offer biologically plausibility to these findings.

  18. 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.

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

    Science.gov (United States)

    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

  20. 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.

  1. 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.

  2. Applying Computerized-Scoring Models of Written Biological Explanations across Courses and Colleges: Prospects and Limitations

    Science.gov (United States)

    Ha, Minsu; Nehm, Ross H.; Urban-Lurain, Mark; Merrill, John E.

    2011-01-01

    Our study explored the prospects and limitations of using machine-learning software to score introductory biology students' written explanations of evolutionary change. We investigated three research questions: 1) Do scoring models built using student responses at one university function effectively at another university? 2) How many human-scored…

  3. Developmental Origins of Biological Explanations: The case of infants' internal property bias.

    Science.gov (United States)

    Taborda-Osorio, Hernando; Cheries, Erik W

    2017-10-01

    People's explanations about the biological world are heavily biased toward internal, non-obvious properties. Adults and children as young as 5 years of age find internal properties more causally central than external features for explaining general biological processes and category membership. In this paper, we describe how this 'internal property bias' may be grounded in two different developmental precursors observed in studies with infants: (1) an early understanding of biological agency that is apparent in infants' reasoning about animals, and (2) the acquisition of kind-based representations that distinguish between essential and accidental properties, spanning from animals to artifacts. We argue that these precursors may support the progressive construction of the notion of biological kinds and explanations during childhood. Shortly after their first year of life, infants seem to represent the internal properties of animates as more central and identity-determining that external properties. Over time, this skeletal notion of biological kinds is integrated into diverse explanations about kind membership and biological processes, with an increasingly better understanding of the causal role of internal properties.

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

    Science.gov (United States)

    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.

  5. 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

  6. 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…

  7. Modeling systems-level dynamics: Understanding without mechanistic explanation in integrative systems biology.

    Science.gov (United States)

    MacLeod, Miles; Nersessian, Nancy J

    2015-02-01

    In this paper we draw upon rich ethnographic data of two systems biology labs to explore the roles of explanation and understanding in large-scale systems modeling. We illustrate practices that depart from the goal of dynamic mechanistic explanation for the sake of more limited modeling goals. These processes use abstract mathematical formulations of bio-molecular interactions and data fitting techniques which we call top-down abstraction to trade away accurate mechanistic accounts of large-scale systems for specific information about aspects of those systems. We characterize these practices as pragmatic responses to the constraints many modelers of large-scale systems face, which in turn generate more limited pragmatic non-mechanistic forms of understanding of systems. These forms aim at knowledge of how to predict system responses in order to manipulate and control some aspects of them. We propose that this analysis of understanding provides a way to interpret what many systems biologists are aiming for in practice when they talk about the objective of a "systems-level understanding." Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. 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

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

    Science.gov (United States)

    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).

  10. 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

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

    Science.gov (United States)

    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…

  12. 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

  13. 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…

  14. 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.

  15. 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.

  16. Gut Microbiome and Obesity: A Plausible Explanation for Obesity.

    Science.gov (United States)

    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.

  17. 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

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

    Science.gov (United States)

    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).

  19. 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…

  20. 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 the model in an undergraduate biology classroom as an educational tool to address some of the known challenges. To find out how well students’ written explanations represent components of the MACH model before and after they were taught about it and why students think the MACH model was useful, we conducted an exploratory multiple case study with four interview participants. We characterize how two students explained biological mechanisms before and after a teaching intervention that used the MACH components. Inductive analysis of written explanations and interviews showed that MACH acted as an effective metacognitive tool for all four students by helping them to monitor their understanding, communicate explanations, and identify explanatory gaps. Further research, though, is needed to more fully substantiate the general usefulness of MACH for promoting students’ metacognition about their understanding of biological mechanisms. PMID:27252295

  1. 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.

  2. Optimality and Plausibility in Language Design

    Directory of Open Access Journals (Sweden)

    Michael R. Levot

    2016-12-01

    Full Text Available The Minimalist Program in generative syntax has been the subject of much rancour, a good proportion of it stoked by Noam Chomsky’s suggestion that language may represent “a ‘perfect solution’ to minimal design specifications.” A particular flash point has been the application of Minimalist principles to speculations about how language evolved in the human species. This paper argues that Minimalism is well supported as a plausible approach to language evolution. It is claimed that an assumption of minimal design specifications like that employed in MP syntax satisfies three key desiderata of evolutionary and general scientific plausibility: Physical Optimism, Rational Optimism, and Darwin’s Problem. In support of this claim, the methodologies employed in MP to maximise parsimony are characterised through an analysis of recent theories in Minimalist syntax, and those methodologies are defended with reference to practices and arguments from evolutionary biology and other natural sciences.

  3. Heuristic Elements of Plausible Reasoning.

    Science.gov (United States)

    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…

  4. 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

  5. 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.

  6. 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…

  7. 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

  8. 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.

  9. Biology Teachers' Conceptions of the Diversity of Life and the Historical Development of Evolutionary Concepts

    Science.gov (United States)

    da Silva, Paloma Rodrigues; de Andrade, Mariana A. Bologna Soares; de Andrade Caldeira, Ana Maria

    2015-01-01

    Biology is a science that involves study of the diversity of living organisms. This diversity has always generated questions and has motivated cultures to seek plausible explanations for the differences and similarities between types of organisms. In biology teaching, these issues are addressed by adopting an evolutionary approach. The aim of this…

  10. Social Groups, Explanation and Ontological Holism | Sheehy ...

    African Journals Online (AJOL)

    The paper begins from the claim that ontological holism is given prima facie plausibility by the apparently ineliminable role of groups in some descriptions and explanations of the social domain. If the individualist accepts the link between indispensabilty and realism, then individualism must show that groups cannot play the ...

  11. Plausibility and evidence: the case of homeopathy.

    Science.gov (United States)

    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.

  12. 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....

  13. 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...

  14. Explanations - Styles of explanation in science

    Science.gov (United States)

    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.

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. 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

  20. Pluralism, Pragmatism and Functional Explanations

    Directory of Open Access Journals (Sweden)

    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.

  1. 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

  2. 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

  3. Age and the Explanation of Crime, Revisited

    Science.gov (United States)

    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…

  4. Research traditions and evolutionary explanations in medicine.

    Science.gov (United States)

    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'.

  5. 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...

  6. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Consciousness and biological evolution.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  11. Students' reasons for preferring teleological explanations

    Science.gov (United States)

    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.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Hierarchy, causation and explanation: ubiquity, locality and pluralism

    Science.gov (United States)

    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

  20. 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…

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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....

  8. 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.…

  9. 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...

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Promoting Scientific Thinking and Conceptual Change about Alternative Explanations of Climate Change and Other Controversial Socio-scientific Topics

    Science.gov (United States)

    Lombardi, D.; Sinatra, G. M.

    2013-12-01

    Critical evaluation and plausibility reappraisal of scientific explanations have been underemphasized in many science classrooms (NRC, 2012). Deep science learning demands that students increase their ability to critically evaluate the quality of scientific knowledge, weigh alternative explanations, and explicitly reappraise their plausibility judgments. Therefore, this lack of instruction about critical evaluation and plausibility reappraisal has, in part, contributed to diminished understanding about complex and controversial topics, such as global climate change. The Model-Evidence Link (MEL) diagram (originally developed by researchers at Rutgers University under an NSF-supported project; Chinn & Buckland, 2012) is an instructional scaffold that promotes students to critically evaluate alternative explanations. We recently developed a climate change MEL and found that the students who used the MEL experienced a significant shift in their plausibility judgments toward the scientifically accepted model of human-induced climate change. Using the MEL for instruction also resulted in conceptual change about the causes of global warming that reflected greater understanding of fundamental scientific principles. Furthermore, students sustained this conceptual change six months after MEL instruction (Lombardi, Sinatra, & Nussbaum, 2013). This presentation will discuss recent educational research that supports use of the MEL to promote critical evaluation, plausibility reappraisal, and conceptual change, and also, how the MEL may be particularly effective for learning about global climate change and other socio-scientific topics. Such instruction to develop these fundamental thinking skills (e.g., critical evaluation and plausibility reappraisal) is demanded by both the Next Generation Science Standards (Achieve, 2013) and the Common Core State Standards for English Language Arts and Mathematics (CCSS Initiative-ELA, 2010; CCSS Initiative-Math, 2010), as well as a

  20. 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...

  1. The Processing of Biologically Plausible and Implausible forms in American Sign Language: Evidence for Perceptual Tuning.

    Science.gov (United States)

    Almeida, Diogo; Poeppel, David; Corina, David

    The human auditory system distinguishes speech-like information from general auditory signals in a remarkably fast and efficient way. Combining psychophysics and neurophysiology (MEG), we demonstrate a similar result for the processing of visual information used for language communication in users of sign languages. We demonstrate that the earliest visual cortical responses in deaf signers viewing American Sign Language (ASL) signs show specific modulations to violations of anatomic constraints that would make the sign either possible or impossible to articulate. These neural data are accompanied with a significantly increased perceptual sensitivity to the anatomical incongruity. The differential effects in the early visual evoked potentials arguably reflect an expectation-driven assessment of somatic representational integrity, suggesting that language experience and/or auditory deprivation may shape the neuronal mechanisms underlying the analysis of complex human form. The data demonstrate that the perceptual tuning that underlies the discrimination of language and non-language information is not limited to spoken languages but extends to languages expressed in the visual modality.

  2. Protein Intake and Muscle Health in Old Age: From Biological Plausibility to Clinical Evidence

    Directory of Open Access Journals (Sweden)

    Francesco Landi

    2016-05-01

    Full Text Available The provision of sufficient amounts of dietary proteins is central to muscle health as it ensures the supply of essential amino acids and stimulates protein synthesis. Older persons, in particular, are at high risk of insufficient protein ingestion. Furthermore, the current recommended dietary allowance for protein (0.8 g/kg/day might be inadequate for maintaining muscle health in older adults, probably as a consequence of “anabolic resistance” in aged muscle. Older individuals therefore need to ingest a greater quantity of protein to maintain muscle function. The quality of protein ingested is also essential to promoting muscle health. Given the role of leucine as the master dietary regulator of muscle protein turnover, the ingestion of protein sources enriched with this essential amino acid, or its metabolite β-hydroxy β-methylbutyrate, is thought to offer the greatest benefit in terms of preservation of muscle mass and function in old age.

  3. On the Biological Plausibility of Grandmother Cells: Implications for Neural Network Theories in Psychology and Neuroscience

    Science.gov (United States)

    Bowers, Jeffrey S.

    2009-01-01

    A fundamental claim associated with parallel distributed processing (PDP) theories of cognition is that knowledge is coded in a distributed manner in mind and brain. This approach rejects the claim that knowledge is coded in a localist fashion, with words, objects, and simple concepts (e.g. "dog"), that is, coded with their own dedicated…

  4. 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

  5. Anticholinergic drugs and negative outcomes in the older population: from biological plausibility to clinical evidence.

    Science.gov (United States)

    Collamati, Agnese; Martone, Anna Maria; Poscia, Andrea; Brandi, Vincenzo; Celi, Michela; Marzetti, Emanuele; Cherubini, Antonio; Landi, Francesco

    2016-02-01

    The use of medication with anticholinergic properties is widespread among older subjects. Many drugs of common use such as antispasmodics, bronchodilators, antiarrhythmics, antihistamines, anti-hypertensive drugs, antiparkinson agents, skeletal muscle relaxants, and psychotropic drugs have been demonstrated to have an anticholinergic activity. The most frequent adverse effects are dry mouth, nausea, vomiting, constipation, abdominal pain, urinary retention, blurred vision, tachycardia and neurologic impairment such as confusion, agitation and coma. A growing evidence from experimental studies and clinical observations suggests that drugs with anticholinergic properties can cause physical and mental impairment in the elderly population. However, the morbidity and management issues associated with unwanted anticholinergic activity are underestimated and frequently overlooked. Moreover, their possible relation with specific negative outcome in the elderly population is still not firmly established. The aim of the present review was to evaluate the relationship between the use of drugs with anticholinergic activity and negative outcomes in older persons. We searched PubMed and Cochrane combining the search terms "anticholinergic", "delirium", "cognitive impairment", "falls", "mortality" and "discontinuation". Medicines with anticholinergic properties may increase the risks of functional and cognitive decline, morbidity, institutionalization and mortality in older people. However, such evidences are still not conclusive probably due to possible confounding factors. In particular, more studies are needed to investigate the effects of discontinuation of drug with anticholinergic properties. Overall, minimizing anticholinergic burden should always be encouraged in clinical practice to improve short-term memory, confusion and delirium, quality of life and daily functioning.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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...

  12. Mesopause Jumps: Observations and Explanation

    Science.gov (United States)

    Luebken, F. J.; Becker, E.; Höffner, J.; Viehl, T. P.; Latteck, R.

    2017-12-01

    Recent high resolution temperature measurements by resonance lidar at Davis (69°S) occasionally showed a sudden mesopause altitude increase by 5km and an associated mesopause temperature decrease by 10K. We present further observations which are closely related to this `mesopause jump', namely the increase of mean height of polar mesospheric summer echoes (PMSE) observed by a VHF radar, very strong westward winds in the upper mesosphere measured by an MF radar, and relatively large eastward winds in the stratosphere taken from reanalysis. We compare to similar observations in the Northern Hemisphere, namely at ALOMAR (69°N) where such mesopause jumps have never been observed. We present a detailed explanation of mesopause jumps. They occur only when stratospheric winds are moderately eastward and mesospheric winds are very large (westward). Under these conditions, gravity waves with comparatively large eastward phase speeds can pass the stratosphere and propagate to the lower thermosphere because their vertical wavelengths in the mesosphere are rather large which implies reduced dynamical stability. When finally breaking in the lower thermosphere, these waves drive an enhanced residual circulation that causes a cold and high-altitude mesopause. The conditions for a mesopause jump occur only in the Southern Hemisphere (SH) and are associated with the late breakdown of the polar vortex.Mesopause jumps are primarily, but not only, observed prior and close to solstice. We also show that during the onset of PMSE in the SH, stratospheric zonal winds are still eastward (up to 30m/s), and that the onset is not closely related to the transition of the stratospheric circulation.

  13. 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.

  14. 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.

  15. 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…

  16. 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…

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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…

  3. 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.

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

    Science.gov (United States)

    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.

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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.

  15. 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

  16. 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

  17. 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...

  18. 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

  19. 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

  20. Generative models versus underlying symmetries to explain biological pattern.

    Science.gov (United States)

    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.

  1. 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.

  2. 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…

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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 ...

  8. 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

  9. 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

  10. 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.

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

    Science.gov (United States)

    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.

  12. 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

  13. 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.

  14. Dual Causality and the Autonomy of Biology.

    Science.gov (United States)

    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.

  15. 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.

  16. 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....

  17. 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

  18. 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.

  19. Comprehensive analysis of schizophrenia-associated loci highlights ion channel pathways and biologically plausible candidate causal genes

    DEFF Research Database (Denmark)

    Pers, Tune H; Timshel, Pascal; Ripke, Stephan

    2016-01-01

    Over 100 associated genetic loci have been robustly associated with schizophrenia. Gene prioritization and pathway analysis have focused on a priori hypotheses and thus may have been unduly influenced by prior assumptions and missed important causal genes and pathways. Using a data-driven approac...

  20. 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...

  1. 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).…

  2. 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…

  3. 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

  4. 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.

  5. 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.)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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 .

  13. 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.

  14. 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).

  15. 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.

  16. 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 ...

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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…

  7. 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…

  8. 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.

  9. 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…

  10. 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…

  11. 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...

  12. 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…

  13. 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…

  14. 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,

  15. 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…

  16. 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…

  17. "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…

  18. 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

  19. An prediction and explanation of 'climatic swing

    Science.gov (United States)

    Barkin, Yury

    2010-05-01

    core-mantle system and their changes in the time have an important role and value for style and intensity of warming and cooling. References [1] Barkin Yu.V. (2002) An explanation of endogenous activity of planets and satellites and its cyclisity. Isvestia sekcii nauk o Zemle Rossiiskoi akademii ectestvennykh nauk. Vyp. 9, М., VINITI, pp. 45-97. In Russian. [2] Barkin Yu.V. (2004) Dynamics of the Earth shells and variations of paleoclimate. Proceedings of Milutin Milankovitch Anniversary Symposium "Paleoclimate and the Earth climate system" (Belgrade, Serbia, 30 August - 2 September, 2004). Belgrade, Serbian Academy of Sciences and Art, pp. 161-164. [3] Barkin Yu.V. (2007) Inversion of periodic and trend variations of climate in opposite hemispheres of the Earth and their mechanism. Proceedings of IUGG XXIV General Assembly, Perugia, Italy 2007: Earth: Our Changing Planet (Perugia, Italy, July 2-13, 2007) (P) - IAPSO, JPS001 "Interannual and Interdecadal Climate Variability", p. 1674. www. iugg2007perugia.it. [4] Barkin Yu.V. (2008) Secular polar drift of the core in present epoch: geodynamical and geophysical consequences and confirmations. General and regional problems of tectonics and geodynamics. Materials of XLI Tectonic Conference. V. 1. -M.:GEOS. p. 55-59. In Russian. [5] Barkin Yu.V. (2009) An explanation of secular variations of a gravity at stations Ny-Alesund, Medicine, Churchill and Syowa. Materials of the International Conference: «Yu.P. Bulashevich's fifth scientific readings. A deep structure. Geodynamics. A thermal field of the Earth. Interpretation of geophysical fields» (Ekaterinburg, 6 - 10 July, 2009). pp. 27-31. In Russian. [6] Barkin Yu.V. (2005) Oscillations of the Earth core, new oceanic tides and dynamical consequences. Materials of XI International Scientific Conference "Structure, geodynamics and mineral genetic processes in lithosphere" (September, 20-22 2005, Syktyvkar, Russia), Publisher of Geology Institute of Komi SC of Ural Section

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

    KAUST Repository

    Abdellah, Marwan; Bilgili, Ahmet; Eilemann, Stefan; Shillcock, Julian; Markram, Henry; Schü rmann, Felix

    2017-01-01

    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

  1. 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

  2. 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.

  3. 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.

  4. Climate change impacts on agriculture in 2050 under a range of plausible socioeconomic and emissions scenarios

    International Nuclear Information System (INIS)

    Wiebe, Keith; Islam, Shahnila; Mason-D’Croz, Daniel; Robertson, Richard; Robinson, Sherman; Lotze-Campen, Hermann; Biewald, Anne; Bodirsky, Benjamin; Müller, Christoph; Popp, Alexander; Sands, Ronald; Tabeau, Andrzej; Van Meijl, Hans; Van der Mensbrugghe, Dominique; Kavallari, Aikaterini; Willenbockel, Dirk

    2015-01-01

    Previous studies have combined climate, crop and economic models to examine the impact of climate change on agricultural production and food security, but results have varied widely due to differences in models, scenarios and input data. Recent work has examined (and narrowed) these differences through systematic model intercomparison using a high-emissions pathway to highlight the differences. This paper extends that analysis to explore a range of plausible socioeconomic scenarios and emission pathways. Results from multiple climate and economic models are combined to examine the global and regional impacts of climate change on agricultural yields, area, production, consumption, prices and trade for coarse grains, rice, wheat, oilseeds and sugar crops to 2050. We find that climate impacts on global average yields, area, production and consumption are similar across shared socioeconomic pathways (SSP 1, 2 and 3, as we implement them based on population, income and productivity drivers), except when changes in trade policies are included. Impacts on trade and prices are higher for SSP 3 than SSP 2, and higher for SSP 2 than for SSP 1. Climate impacts for all variables are similar across low to moderate emissions pathways (RCP 4.5 and RCP 6.0), but increase for a higher emissions pathway (RCP 8.5). It is important to note that these global averages may hide regional variations. Projected reductions in agricultural yields due to climate change by 2050 are larger for some crops than those estimated for the past half century, but smaller than projected increases to 2050 due to rising demand and intrinsic productivity growth. Results illustrate the sensitivity of climate change impacts to differences in socioeconomic and emissions pathways. Yield impacts increase at high emissions levels and vary with changes in population, income and technology, but are reduced in all cases by endogenous changes in prices and other variables. (paper)

  5. Flux-based transport enhancement as a plausible unifying mechanism for auxin transport in meristem development.

    Directory of Open Access Journals (Sweden)

    Szymon Stoma

    2008-10-01

    Full Text Available Plants continuously generate new organs through the activity of populations of stem cells called meristems. The shoot apical meristem initiates leaves, flowers, and lateral meristems in highly ordered, spiralled, or whorled patterns via a process called phyllotaxis. It is commonly accepted that the active transport of the plant hormone auxin plays a major role in this process. Current hypotheses propose that cellular hormone transporters of the PIN family would create local auxin maxima at precise positions, which in turn would lead to organ initiation. To explain how auxin transporters could create hormone fluxes to distinct regions within the plant, different concepts have been proposed. A major hypothesis, canalization, proposes that the auxin transporters act by amplifying and stabilizing existing fluxes, which could be initiated, for example, by local diffusion. This convincingly explains the organised auxin fluxes during vein formation, but for the shoot apical meristem a second hypothesis was proposed, where the hormone would be systematically transported towards the areas with the highest concentrations. This implies the coexistence of two radically different mechanisms for PIN allocation in the membrane, one based on flux sensing and the other on local concentration sensing. Because these patterning processes require the interaction of hundreds of cells, it is impossible to estimate on a purely intuitive basis if a particular scenario is plausible or not. Therefore, computational modelling provides a powerful means to test this type of complex hypothesis. Here, using a dedicated computer simulation tool, we show that a flux-based polarization hypothesis is able to explain auxin transport at the shoot meristem as well, thus providing a unifying concept for the control of auxin distribution in the plant. Further experiments are now required to distinguish between flux-based polarization and other hypotheses.

  6. A plausible (overlooked) super-luminous supernova in the Sloan digital sky survey stripe 82 data

    International Nuclear Information System (INIS)

    Kostrzewa-Rutkowska, Zuzanna; Kozłowski, Szymon; Wyrzykowski, Łukasz; Djorgovski, S. George; Mahabal, Ashish A.; Glikman, Eilat; Koposov, Sergey

    2013-01-01

    We present the discovery of a plausible super-luminous supernova (SLSN), found in the archival data of Sloan Digital Sky Survey (SDSS) Stripe 82, called PSN 000123+000504. The supernova (SN) peaked at m g < 19.4 mag in the second half of 2005 September, but was missed by the real-time SN hunt. The observed part of the light curve (17 epochs) showed that the rise to the maximum took over 30 days, while the decline time lasted at least 70 days (observed frame), closely resembling other SLSNe of SN 2007bi type. The spectrum of the host galaxy reveals a redshift of z = 0.281 and the distance modulus of μ = 40.77 mag. Combining this information with the SDSS photometry, we found the host galaxy to be an LMC-like irregular dwarf galaxy with an absolute magnitude of M B = –18.2 ± 0.2 mag and an oxygen abundance of 12+log [O/H]=8.3±0.2; hence, the SN peaked at M g < –21.3 mag. Our SLSN follows the relation for the most energetic/super-luminous SNe exploding in low-metallicity environments, but we found no clear evidence for SLSNe to explode in low-luminosity (dwarf) galaxies only. The available information on the PSN 000123+000504 light curve suggests the magnetar-powered model as a likely scenario of this event. This SLSN is a new addition to a quickly growing family of super-luminous SNe.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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)

  13. 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...

  14. 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)

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. Effective Teacher Practice on the Plausibility of Human-Induced Climate Change

    Science.gov (United States)

    Niepold, F.; Sinatra, G. M.; Lombardi, D.

    2013-12-01

    Climate change education programs in the United States seek to promote a deeper understanding of the science of climate change, behavior change and stewardship, and support informed decision making by individuals, organizations, and institutions--all of which are summarized under the term 'climate literacy.' The ultimate goal of climate literacy is to enable actors to address climate change, both in terms of stabilizing and reducing emissions of greenhouse gases, but also an increased capacity to prepare for the consequences and opportunities of climate change. However, the long-term nature of climate change and the required societal response involve the changing students' ideas about controversial scientific issues which presents unique challenges for educators (Lombardi & Sinatra, 2010; Sinatra & Mason, 2008). This session will explore how the United States educational efforts focus on three distinct, but related, areas: the science of climate change, the human-climate interaction, and using climate education to promote informed decision making. Each of these approaches are represented in the Atlas of Science Literacy (American Association for the Advancement of Science, 2007) and in the conceptual framework for science education developed at the National Research Council (NRC) in 2012. Instruction to develop these fundamental thinking skills (e.g., critical evaluation and plausibility reappraisal) has been called for by the Next Generation Science Standards (NGSS) (Achieve, 2013), an innovative and research based way to address climate change education within the decentralized U.S. education system. However, the promise of the NGSS is that students will have more time to build mastery on the subjects, but the form of that instructional practice has been show to be critical. Research has show that effective instructional activities that promote evaluation of evidence improve students' understanding and acceptance toward the scientifically accepted model of human

  1. 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...

  2. 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

  3. 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…

  4. 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)

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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,…

  13. 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 ...

  14. 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…

  15. 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…

  16. 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,

  17. 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 ...

  18. 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

  19. 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...

  20. 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.

  1. 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)

  2. 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.

  3. 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:

  4. 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.

  5. 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

  6. 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…

  7. 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…

  8. Sex ratio meiotic drive as a plausible evolutionary mechanism for hybrid male sterility.

    Directory of Open Access Journals (Sweden)

    Linbin Zhang

    2015-03-01

    Full Text Available Biological diversity on Earth depends on the multiplication of species or speciation, which is the evolution of reproductive isolation such as hybrid sterility between two new species. An unsolved puzzle is the exact mechanism(s that causes two genomes to diverge from their common ancestor so that some divergent genes no longer function properly in the hybrids. Here we report genetic analyses of divergent genes controlling male fertility and sex ratio in two very young fruitfly species, Drosophila albomicans and D. nasuta. A majority of the genetic divergence for both traits is mapped to the same regions by quantitative trait loci mappings. With introgressions, six major loci are found to contribute to both traits. This genetic colocalization implicates that genes for hybrid male sterility have evolved primarily for controlling sex ratio. We propose that genetic conflicts over sex ratio may operate as a perpetual dynamo for genome divergence. This particular evolutionary mechanism may largely contribute to the rapid evolution of hybrid male sterility and the disproportionate enrichment of its underlying genes on the X chromosome--two patterns widely observed across animals.

  9. Plausible Roles for RAGE in Conditions Exacerbated by Direct and Indirect (Secondhand) Smoke Exposure.

    Science.gov (United States)

    Lewis, Joshua B; Hirschi, Kelsey M; Arroyo, Juan A; Bikman, Benjamin T; Kooyman, David L; Reynolds, Paul R

    2017-03-17

    Approximately 1 billion people smoke worldwide, and the burden placed on society by primary and secondhand smokers is expected to increase. Smoking is the leading risk factor for myriad health complications stemming from diverse pathogenic programs. First- and second-hand cigarette smoke contains thousands of constituents, including several carcinogens and cytotoxic chemicals that orchestrate chronic inflammatory responses and destructive remodeling events. In the current review, we outline details related to compromised pulmonary and systemic conditions related to smoke exposure. Specifically, data are discussed relative to impaired lung physiology, cancer mechanisms, maternal-fetal complications, cardiometabolic, and joint disorders in the context of smoke exposure exacerbations. As a general unifying mechanism, the receptor for advanced glycation end-products (RAGE) and its signaling axis is increasingly considered central to smoke-related pathogenesis. RAGE is a multi-ligand cell surface receptor whose expression increases following cigarette smoke exposure. RAGE signaling participates in the underpinning of inflammatory mechanisms mediated by requisite cytokines, chemokines, and remodeling enzymes. Understanding the biological contributions of RAGE during cigarette smoke-induced inflammation may provide critically important insight into the pathology of lung disease and systemic complications that combine during the demise of those exposed.

  10. Nutritional links to plausible mechanisms underlying pancreatic cancer: a conference report.

    Science.gov (United States)

    Hine, R Jean; Srivastava, Sudhir; Milner, John A; Ross, Sharon A

    2003-11-01

    Adenocarcinoma of the pancreas is one of most catastrophic and least understood of cancers. Evidence from clinical studies indicates that the development of pancreas cancer progresses over many years before symptoms appear. Most people with pancreatic cancer die within six months of diagnosis. The lack of early disease markers, the paucity of direct subject/patient interview data and limited availability of high quality biological samples have slowed progress toward identifying environmental and genetic disease risk factors. Much remains to be learned about the development of pancreatic cancer and about potential interventions for disease prevention. Epidemiological and mechanistic studies examining risk factors for pancreatic cancer supply little consistent or strong evidence to provide a cohesive prevention strategy for this cancer, but offer clues for future research concerning the prevention and early detection of this devastating disease. This Executive Summary provides background discussion on pancreatic cancer and summaries of each of the topics discussed at the workshop, including 1) Molecular aspects, 2) Dietary and other risk factors for pancreatic cancer, 3) The metabolic hypothesis for pancreatic cancer, 4) Preclinical studies on pancreatic cancer, 5) Methylation, 6) Oxidative stress and 7) Biomarker Profiling. This document also contains a compilation of recommendations for future research, concluding remarks, a list of speakers and participants attending the workshop, and a selection of key references to aid future research into nutritional links to mechanisms underlying pancreas cancer. The recommendations section suggests gaps in current knowledge and articulates future directions for this area of investigation.

  11. Sex ratio meiotic drive as a plausible evolutionary mechanism for hybrid male sterility.

    Science.gov (United States)

    Zhang, Linbin; Sun, Tianai; Woldesellassie, Fitsum; Xiao, Hailian; Tao, Yun

    2015-03-01

    Biological diversity on Earth depends on the multiplication of species or speciation, which is the evolution of reproductive isolation such as hybrid sterility between two new species. An unsolved puzzle is the exact mechanism(s) that causes two genomes to diverge from their common ancestor so that some divergent genes no longer function properly in the hybrids. Here we report genetic analyses of divergent genes controlling male fertility and sex ratio in two very young fruitfly species, Drosophila albomicans and D. nasuta. A majority of the genetic divergence for both traits is mapped to the same regions by quantitative trait loci mappings. With introgressions, six major loci are found to contribute to both traits. This genetic colocalization implicates that genes for hybrid male sterility have evolved primarily for controlling sex ratio. We propose that genetic conflicts over sex ratio may operate as a perpetual dynamo for genome divergence. This particular evolutionary mechanism may largely contribute to the rapid evolution of hybrid male sterility and the disproportionate enrichment of its underlying genes on the X chromosome--two patterns widely observed across animals.

  12. The apoptotic effect and the plausible mechanism of microwave radiation on rat myocardial cells.

    Science.gov (United States)

    Zhu, Wenhe; Cui, Yan; Feng, Xianmin; Li, Yan; Zhang, Wei; Xu, Junjie; Wang, Huiyan; Lv, Shijie

    2016-08-01

    Microwaves may exert adverse biological effects on the cardiovascular system at the integrated system and cellular levels. However, the mechanism underlying such effects remains poorly understood. Here, we report a previously uncharacterized mechanism through which microwaves damage myocardial cells. Rats were treated with 2450 MHz microwave radiation at 50, 100, 150, or 200 mW/cm(2) for 6 min. Microwave treatment significantly enhanced the levels of various enzymes in serum. In addition, it increased the malondialdehyde content while decreasing the levels of antioxidative stress enzymes, activities of enzyme complexes I-IV, and ATP in myocardial tissues. Notably, irradiated myocardial cells exhibited structural damage and underwent apoptosis. Furthermore, Western blot analysis revealed significant changes in expression levels of proteins involved in oxidative stress regulation and apoptotic signaling pathways, indicating that microwave irradiation could induce myocardial cell apoptosis by interfering with oxidative stress and cardiac energy metabolism. Our findings provide useful insights into the mechanism of microwave-induced damage to the cardiovascular system.

  13. Virtual Neurorobotics (VNR) to Accelerate Development of Plausible Neuromorphic Brain Architectures.

    Science.gov (United States)

    Goodman, Philip H; Buntha, Sermsak; Zou, Quan; Dascalu, Sergiu-Mihai

    2007-01-01

    Traditional research in artificial intelligence and machine learning has viewed the brain as a specially adapted information-processing system. More recently the field of social robotics has been advanced to capture the important dynamics of human cognition and interaction. An overarching societal goal of this research is to incorporate the resultant knowledge about intelligence into technology for prosthetic, assistive, security, and decision support applications. However, despite many decades of investment in learning and classification systems, this paradigm has yet to yield truly "intelligent" systems. For this reason, many investigators are now attempting to incorporate more realistic neuromorphic properties into machine learning systems, encouraged by over two decades of neuroscience research that has provided parameters that characterize the brain's interdependent genomic, proteomic, metabolomic, anatomic, and electrophysiological networks. Given the complexity of neural systems, developing tenable models to capture the essence of natural intelligence for real-time application requires that we discriminate features underlying information processing and intrinsic motivation from those reflecting biological constraints (such as maintaining structural integrity and transporting metabolic products). We propose herein a conceptual framework and an iterative method of virtual neurorobotics (VNR) intended to rapidly forward-engineer and test progressively more complex putative neuromorphic brain prototypes for their ability to support intrinsically intelligent, intentional interaction with humans. The VNR system is based on the viewpoint that a truly intelligent system must be driven by emotion rather than programmed tasking, incorporating intrinsic motivation and intentionality. We report pilot results of a closed-loop, real-time interactive VNR system with a spiking neural brain, and provide a video demonstration as online supplemental material.

  14. Virtual neurorobotics (VNR to accelerate development of plausible neuromorphic brain architectures

    Directory of Open Access Journals (Sweden)

    Philip H Goodman

    2007-11-01

    Full Text Available Traditional research in artificial intelligence and machine learning has viewed the brain as a specially adapted information-processing system. More recently the field of social robotics has been advanced to capture the important dynamics of human cognition and interaction. An overarching societal goal of this research is to incorporate the resultant knowledge about intelligence into technology for prosthetic, assistive, security, and decision support applications. However, despite many decades of investment in learning and classification systems, this paradigm has yet to yield truly “intelligent” systems. For this reason, many investigators are now attempting to incorporate more realistic neuromorphic properties into machine learning systems, encouraged by over two decades of neuroscience research that has provided parameters that characterize the brain’s interdependent genomic, proteomic, metabolomic, anatomic, and electrophysiological networks. Given the complexity of neural systems, developing tenable models to capture the essence of natural intelligence for real-time application requires that we discriminate features underlying information processing and intrinsic motivation from those reflecting biological constraints (such as maintaining structural integrity and transporting metabolic products. We propose herein a conceptual framework and an iterative method of virtual neurorobotics (VNR intended to rapidly forward-engineer and test progressively more complex putative neuromorphic brain prototypes for their ability to support intrinsically intelligent, intentional interaction with humans. The VNR system is based on the viewpoint that a truly intelligent system must be driven by emotion rather than programmed tasking, incorporating intrinsic motivation and intentionality. We report pilot results of a closed-loop, real-time interactive VNR system with a spiking neural brain, and provide a video demonstration as online supplemental

  15. 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.

  16. Preschool Teachers' Explanations for Hygiene Habits and Young Children's Biological Awareness of Contamination

    Science.gov (United States)

    Toyama, Noriko

    2016-01-01

    Research Findings: Preschools have many norms and rules children are supposed to follow. Among them, behavioral norms associated with mealtime are of great consequence because eating is an essential life function. The present study examined young Japanese children's understanding of hygiene norms and rules at mealtime from the standpoint of their…

  17. A US-China Interview Study: Biology Students' Argumentation and Explanation about Energy Consumption Issues

    Science.gov (United States)

    Jin, Hui; Hokayem, Hayat; Wang, Sasha; Wei, Xin

    2016-01-01

    As China and the United States become the top two carbon emitters in the world, it is crucial for citizens in both countries to construct a sophisticated understanding of energy consumption issues. This interview study examines how U.S. and Chinese students compare in explaining and arguing about two critical energy consumption issues: burning…

  18. 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.

  19. 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,…

  20. 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…

  1. 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...

  2. 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”.

  3. 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.

  4. 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

  5. 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)

  6. 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....

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Biological Agents

    Science.gov (United States)

    ... E-Tools Safety and Health Topics / Biological Agents Biological Agents This page requires that javascript be enabled ... 202) 693-2300 if additional assistance is required. Biological Agents Menu Overview In Focus: Ebola Frederick A. ...

  16. 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.

  17. 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

  18. HIV in Japan: Epidemiologic puzzles and ethnographic explanations

    Directory of Open Access Journals (Sweden)

    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

  19. 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.

  20. 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 ...

  1. 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.

  2. 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

  3. 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...

  4. Pathways to plausibility

    DEFF Research Database (Denmark)

    Wahlberg, Ayo

    2008-01-01

    Herbal medicine has long been contrasted to modern medicine in terms of a holistic approach to healing, vitalistic theories of health and illness and an emphasis on the body’s innate self-healing capacities. At the same time, since the early 20th century, the cultivation, preparation and mass...... production of herbal medicines have become increasingly industrialised, scientificised and commercialised. What is more, phytochemical efforts to identify and isolate particular ‘active ingredients’ from whole-plant extracts have intensified, often in response to increasing regulatory scrutiny of the safety...... and quality of herbal medicinal products. In this paper, I examine whether describing these developments in terms of a biomedical ‘colonisation’ of herbal medicine, as has been common, allows us to sufficiently account for the mundane collaborative efforts of herbalists, botanists, phytochemists...

  5. Emerging role of Hippo signalling in pancreatic biology: YAP re-expression and plausible link to islet cell apoptosis and replication.

    Science.gov (United States)

    Sharma, Anjana; Yerra, Veera Ganesh; Kumar, Ashutosh

    2017-02-01

    Diabetes mellitus is an ailment that develops when the functional capacity of the pancreas does not meet the metabolic requirements of the whole body, either due to insulin insufficiency or resistance to insulin action. Current therapies that control glycaemia are limited by their unwanted effects or their inability to prevent the development of long-term complications. Regeneration and replacement of beta cell therapies are shaping the goals of future management of diabetes. The Hippo pathway, first discovered in Drosophila melanogaster, plays a vital role in controlling the organ size. Nuclear recruitment of YAP/TAZ (Yes-associated protein/transcriptional co-activator with PDZ-binding motif), a mammalian analogue of Yorkie protein found in Drosophila, activates cell proliferation and inhibits apoptosis. YAP was found to regulate early pancreatic development followed by downregulation during Ngn3-specific endocrine lineage maturation corresponding to their mitotic quiescence. Recent evidences have shown that optimum modulation of upstream kinases in the Hippo signalling pathway may lead to apoptosis inhibition and renewal of progenitor as well as stem cells in case of tissue or cell injury. This article reviews the evidences linking the role of various components of the Hippo pathway to pancreatic regeneration. In particular, the focus is on the beneficial role of induced YAP expression and its nuclear distribution on apoptosis and replication of adult pancreatic β islets. This approach may be of immense significance towards our fight against diabetes; thus, more insightful research is warranted in the area of Hippo signalling pathway and its involvement in pancreatic regeneration. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. A genome-wide association meta-analysis of diarrhoeal disease in young children identifies FUT2 locus and provides plausible biological pathways

    DEFF Research Database (Denmark)

    Bustamante, Mariona; Standl, Marie; Bassat, Quique

    2016-01-01

    implicated in the susceptibility to infections, including Rotavirus and Norovirus Gene-set enrichment analysis suggested pathways related to the histo-blood group antigen production, and the regulation of ion transport and blood pressure. Among others, the gastrointestinal tract, and the immune and neuro...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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....

  13. 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.

  14. 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...

  15. Self-focused and other-focused resiliency: Plausible mechanisms linking early family adversity to health problems in college women.

    Science.gov (United States)

    Coleman, Sulamunn R M; Zawadzki, Matthew J; Heron, Kristin E; Vartanian, Lenny R; Smyth, Joshua M

    2016-01-01

    This study examined whether self-focused and other-focused resiliency help explain how early family adversity relates to perceived stress, subjective health, and health behaviors in college women. Female students (N = 795) participated between October 2009 and May 2010. Participants completed self-report measures of early family adversity, self-focused (self-esteem, personal growth initiative) and other-focused (perceived social support, gratitude) resiliency, stress, subjective health, and health behaviors. Using structural equation modeling, self-focused resiliency associated with less stress, better subjective health, more sleep, less smoking, and less weekend alcohol consumption. Other-focused resiliency associated with more exercise, greater stress, and more weekend alcohol consumption. Early family adversity was indirectly related to all health outcomes, except smoking, via self-focused and other-focused resiliency. Self-focused and other-focused resiliency represent plausible mechanisms through which early family adversity relates to stress and health in college women. This highlights areas for future research in disease prevention and management.

  16. Synchronous volcanic eruptions and abrupt climate change ∼17.7 ka plausibly linked by stratospheric ozone depletion.

    Science.gov (United States)

    McConnell, Joseph R; Burke, Andrea; Dunbar, Nelia W; Köhler, Peter; Thomas, Jennie L; Arienzo, Monica M; Chellman, Nathan J; Maselli, Olivia J; Sigl, Michael; Adkins, Jess F; Baggenstos, Daniel; Burkhart, John F; Brook, Edward J; Buizert, Christo; Cole-Dai, Jihong; Fudge, T J; Knorr, Gregor; Graf, Hans-F; Grieman, Mackenzie M; Iverson, Nels; McGwire, Kenneth C; Mulvaney, Robert; Paris, Guillaume; Rhodes, Rachael H; Saltzman, Eric S; Severinghaus, Jeffrey P; Steffensen, Jørgen Peder; Taylor, Kendrick C; Winckler, Gisela

    2017-09-19

    Glacial-state greenhouse gas concentrations and Southern Hemisphere climate conditions persisted until ∼17.7 ka, when a nearly synchronous acceleration in deglaciation was recorded in paleoclimate proxies in large parts of the Southern Hemisphere, with many changes ascribed to a sudden poleward shift in the Southern Hemisphere westerlies and subsequent climate impacts. We used high-resolution chemical measurements in the West Antarctic Ice Sheet Divide, Byrd, and other ice cores to document a unique, ∼192-y series of halogen-rich volcanic eruptions exactly at the start of accelerated deglaciation, with tephra identifying the nearby Mount Takahe volcano as the source. Extensive fallout from these massive eruptions has been found >2,800 km from Mount Takahe. Sulfur isotope anomalies and marked decreases in ice core bromine consistent with increased surface UV radiation indicate that the eruptions led to stratospheric ozone depletion. Rather than a highly improbable coincidence, circulation and climate changes extending from the Antarctic Peninsula to the subtropics-similar to those associated with modern stratospheric ozone depletion over Antarctica-plausibly link the Mount Takahe eruptions to the onset of accelerated Southern Hemisphere deglaciation ∼17.7 ka.

  17. The Plausibility of Tonal Evolution in the Malay Dialect Spoken in Thailand: Evidence from an Acoustic Study

    Directory of Open Access Journals (Sweden)

    Phanintra Teeranon

    2007-12-01

    Full Text Available The F0 values of vowels following voiceless consonants are higher than those of vowels following voiced consonants; high vowels have a higher F0 than low vowels. It has also been found that when high vowels follow voiced consonants, the F0 values decrease. In contrast, low vowels following voiceless consonants show increasing F0 values. In other words, the voicing of initial consonants has been found to counterbalance the intrinsic F0 values of high and low vowels (House and Fairbanks 1953, Lehiste and Peterson 1961, Lehiste 1970, Laver 1994, Teeranon 2006. To test whether these three findings are applicable to a disyllabic language, the F0 values of high and low vowels following voiceless and voiced consonants were studied in a Malay dialect of the Austronesian language family spoken in Pathumthani Province, Thailand. The data was collected from three male informants, aged 30-35. The Praat program was used for acoustic analysis. The findings revealed the influence of the voicing of initial consonants on the F0 of vowels to be greater than that of the influence of vowel height. Evidence from this acoustic study shows the plausibility for the Malay dialect spoken in Pathumthani to become a tonal language by the influence of initial consonants rather by the influence of the high-low vowel dimension.

  18. Bilinguals' Plausibility Judgments for Phrases with a Literal vs. Non-literal Meaning: The Influence of Language Brokering Experience

    Directory of Open Access Journals (Sweden)

    Belem G. López

    2017-09-01

    Full Text Available Previous work has shown that prior experience in language brokering (informal translation may facilitate the processing of meaning within and across language boundaries. The present investigation examined the influence of brokering on bilinguals' processing of two word collocations with either a literal or a figurative meaning in each language. Proficient Spanish-English bilinguals classified as brokers or non-brokers were asked to judge if adjective+noun phrases presented in each language made sense or not. Phrases with a literal meaning (e.g., stinging insect were interspersed with phrases with a figurative meaning (e.g., stinging insult and non-sensical phrases (e.g., stinging picnic. It was hypothesized that plausibility judgments would be facilitated for literal relative to figurative meanings in each language but that experience in language brokering would be associated with a more equivalent pattern of responding across languages. These predictions were confirmed. The findings add to the body of empirical work on individual differences in language processing in bilinguals associated with prior language brokering experience.

  19. 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

  20. Causal explanation, intentionality, and prediction: Evaluating the Criticism of "Deductivism"

    DEFF Research Database (Denmark)

    Koch, Carsten Allan

    2001-01-01

    In a number of influential contributions, Tony Lawson has attacked a view of science that he refers to as deductivism, and criticized economists for implicitly using it in their research. Lawson argues that deductivism is simply the covering-law model, also known as the causal model of scientific...... critisizes the use of universal laws in social science, especially in economics. This view cannot be as easily dismissed as his general criticism of causal explanation. We argue that a number of arguments often used against the existence of (correct) universal laws in the social sciences can be put...... into question. First, it is argued that entities need not be identical, or even remotely alike, to be applicable to the same law. What is necessary is that they have common properties, e.g. mass in physics, and that the law relates to that property (section 6). Second, one might take the so-called model...

  1. 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.

  2. Disordered locality as an explanation for the dark energy

    International Nuclear Information System (INIS)

    Prescod-Weinstein, Chanda; Smolin, Lee

    2009-01-01

    We discuss a novel explanation of the dark energy as a manifestation of macroscopic nonlocality coming from quantum gravity, as proposed by Markopoulou [F. Markopoulou (private communication)]. It has been previously suggested that in a transition from an early quantum geometric phase of the Universe to a low temperature phase characterized by an emergent spacetime metric, locality might have been 'disordered'. This means that there is a mismatch of micro-locality, as determined by the microscopic quantum dynamics and macro-locality as determined by the classical metric that governs the emergent low energy physics. In this paper we discuss the consequences for cosmology by studying a simple extension of the standard cosmological models with disordered locality. We show that the consequences can include a naturally small vacuum energy.

  3. Explanation of significant differences for the TNX groundwater operable unit

    International Nuclear Information System (INIS)

    Palmer, E.R.

    1997-01-01

    This Explanation of Significant Differences (ESD) is being issued by the Department of Energy (DOE), the lead agency for the Savannah River Site (SRS), with concurrence by the Environmental Protection Agency-Region IV (EPA) and South Carolina Department of Health and Environmental Control (SCDHEC) to announce changes in the interim remediation strategy selected for the TNX Groundwater Operable Unit. The TNX Area is located adjacent to the Savannah River in the southwestern portion of SRS. The remedy selected in the Interim Record of Decision (IROD) to achieve the interim action goals was the Hybrid Groundwater Corrective Action (HGCA). The HGCA consisted of a recirculation well system and an air stripper with a series of groundwater extraction wells. The original remediation strategy needs to be modified because the recirculation well system was determined to be ineffective in this area due to geological factors and the nature of the contamination

  4. An Explanation of True Dreams: Aristotle and Jung

    Directory of Open Access Journals (Sweden)

    Ali Sanai

    2016-12-01

    Full Text Available The naturalistic explanation of realized dream (or dreams that come true means that this phenomen will be explained regardless of supernatural agents. Aristotle in Parva naturalia and Jung in his works explained dream visionary. In this article by scrutiny on these thinkers’ theory, we will indicate the naturalistic approach to dream that is far- fetched for followers of metaphysics. In spite of this fact that Aristotle and Jung both belongs to different historical contexts, they have common aspects in terms of naturalistic method; in the universal or broad sense of word, but in terms of content both explain the true dream by the term “coincidence” or accidental conformity between objective events and psychological affairs. It also seems that the notion of Neutral monism in Jung is adaptive to Hylomorphism in Aristotle psychology, and this, provides a path for naturalistic approach to dream as one forms of consciousness.

  5. Theories of International Relations and the Explanation of Foreign Aid

    Directory of Open Access Journals (Sweden)

    PAUSELLI, Gino

    2013-06-01

    Full Text Available 50 years after the publication of the first and influential article in international relations (IR analyzing foreign aid motivations, A theory of foreign aid, by Hans Morgenthau, IR scholarship has not yet accomplished a consistent theoretical body explaining international development cooperation. Most of the empirical studies on foreign aid have been contributions from other disciplines, especially economics. Research from the field of international relations has been mostly descriptive or poorly connected with IR paradigms.This article proposes to analyze motivations of foreign aid allocations decisions of donors. These motivations will be examined from the theoretical perspective of the international relations scholarship. In this way, it is sought to contribute, from the discipline of IR, to the explanation of the process in which developed countries make transfers of resources to developing countries.

  6. Rethinking the health selection explanation for health inequalities.

    Science.gov (United States)

    West, P

    1991-01-01

    As one of several explanations for class differentials in health, health selection has received remarkably little systematic attention in the inequalities debate. It is widely regarded as having (at best) a very minor role in the production of inequalities, and a theoretical debt to social Darwinism. This paper examines the validity of those assumptions in terms of the evidence which has emerged since the publication of the 'Black Report'. It is suggested that it is too easy to write off health selection as of little or no significance, and that reconceptualising the issue within a specifically sociological perspective owing much to labelling theory offers much greater potential for understanding the processes involved. From this perspective, health selection has many of the features of discrimination of the sort that characterises race and sex.

  7. Modern Biology

    OpenAIRE

    ALEKSIC, Branko

    2014-01-01

    The purpose of this course is to learn the philosophy, principles, and techniques of modern biology. The course is particularly designed for those who have not learned biology previously or whose major is other than biology, and who may think that they do not need to know any biology at all. The topics are covered in a rather general, overview manner, but certain level of diligence in grasping concepts and memorizing the terminology is expected.

  8. 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.

  9. 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.

  10. 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

  11. 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).

  12. The Mediterranean dietary pattern as the diet of choice for non-alcoholic fatty liver disease: Evidence and plausible mechanisms.

    Science.gov (United States)

    Zelber-Sagi, Shira; Salomone, Federico; Mlynarsky, Liat

    2017-07-01

    Non-alcoholic fatty liver disease (NAFLD) has become a major global health burden, leading to increased risk for cirrhosis, hepatocellular carcinoma, type-2 diabetes and cardiovascular disease. Lifestyle intervention aiming at weight reduction is the most established treatment. However, changing the dietary composition even without weight loss can also reduce steatosis and improve metabolic alterations as insulin resistance and lipid profile. The Mediterranean diet (MD) pattern has been proposed as appropriate for this goal, and was recommended as the diet of choice for the treatment of NAFLD by the EASL-EASD-EASO Clinical Practice Guidelines. The MD has an established superiority in long term weight reduction over low fat diet, but it improves metabolic status and steatosis even without it. However, the effect on liver inflammation and fibrosis was tested only in few observational studies with positive results. Furthermore, considering the strong association between NAFLD and diabetes and CVD, the MD has a highly established advantage in prevention of these diseases, demonstrated in randomized clinical trials. The individual components of the MD such as olive oil, fish, nuts, whole grains, fruits, and vegetables, have been shown to beneficially effect or negatively correlate with NAFLD, while consumption of components that characterize a Western dietary pattern as soft drinks, fructose, meat and saturated fatty acids have been shown to have detrimental association with NAFLD. In this review we will cover the epidemiological evidence and the plausible molecular mechanisms by which the MD as a whole and each of its components can be of benefit in NAFLD. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Developing spatially explicit footprints of plausible land-use scenarios in the Santa Cruz Watershed, Arizona and Sonora

    Science.gov (United States)

    Norman, Laura M.; Feller, Mark; Villarreal, Miguel L.

    2012-01-01

    The SLEUTH urban growth model is applied to a binational dryland watershed to envision and evaluate plausible future scenarios of land use change into the year 2050. Our objective was to create a suite of geospatial footprints portraying potential land use change that can be used to aid binational decision-makers in assessing the impacts relative to sustainability of natural resources and potential socio-ecological consequences of proposed land-use management. Three alternatives are designed to simulate different conditions: (i) a Current Trends Scenario of unmanaged exponential growth, (ii) a Conservation Scenario with managed growth to protect the environment, and (iii) a Megalopolis Scenario in which growth is accentuated around a defined international trade corridor. The model was calibrated with historical data extracted from a time series of satellite images. Model materials, methodology, and results are presented. Our Current Trends Scenario predicts the footprint of urban growth to approximately triple from 2009 to 2050, which is corroborated by local population estimates. The Conservation Scenario results in protecting 46% more of the Evergreen class (more than 150,000 acres) than the Current Trends Scenario and approximately 95,000 acres of Barren Land, Crops, Deciduous Forest (Mesquite Bosque), Grassland/Herbaceous, Urban/Recreational Grasses, and Wetlands classes combined. The Megalopolis Scenario results also depict the preservation of some of these land-use classes compared to the Current Trends Scenario, most notably in the environmentally important headwaters region. Connectivity and areal extent of land cover types that provide wildlife habitat were preserved under the alternative scenarios when compared to Current Trends.

  14. 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…

  15. The discourse of causal explanations in school science

    Science.gov (United States)

    Slater, Tammy Jayne Anne

    Researchers and educators working from a systemic functional linguistic perspective have provided a body of work on science discourse which offers an excellent starting point for examining the linguistic aspects of the development of causal discourse in school science, discourse which Derewianka (1995) claimed is critical to success in secondary school. No work has yet described the development of causal language by identifying the linguistic features present in oral discourse or by comparing the causal discourse of native and non-native (ESL) speakers of English. The current research responds to this gap by examining the oral discourse collected from ESL and non-ESL students at the primary and high school grades. Specifically, it asks the following questions: (1) How do the teachers and students in these four contexts develop causal explanations and their relevant taxonomies through classroom interactions? (2) What are the causal discourse features being used by the students in these four contexts to construct oral causal explanations? The findings of the social practice analysis showed that the teachers in the four contexts differed in their approaches to teaching, with the primary school mainstream teacher focusing largely on the hands-on practice , the primary school ESL teacher moving from practice to theory, the high school mainstream teacher moving from theory to practice, and the high school ESL teacher relying primarily on theory. The findings from the quantitative, small corpus approach suggest that the developmental path of cause which has been identified in the writing of experts shows up not only in written texts but also in the oral texts which learners construct. Moreover, this move appears when the discourse of high school ESL and non-ESL students is compared, suggesting a developmental progression in the acquisition of these features by these students. The findings also reveal that the knowledge constructed, as shown by the concept maps created

  16. Cognitive dissonance as an explanation of the genesis, evolution ...

    African Journals Online (AJOL)

    The steady erosion of support for this flagrant HIV denialism, together with the rise of neoliberal thinking in the ANC, would lead to the evolution of this biological denialism into a form of treatment denialism. This ideology argued against the widespread provision and use of antiretroviral treatment. Empirical evidence is ...

  17. 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.

  18. 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).

  19. 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

  20. Strategy in the 20th Century: Explanations from History

    Directory of Open Access Journals (Sweden)

    Leonardo Silveira Conke

    2013-12-01

    Full Text Available In this essay, we argue that an historical perspective helps to understand some of the strategic choices made by organizations. More specifically, the purpose here is to describe the great influence of historical events (related to economy, politics, technological advancement etc. on the creation, acceptance, spreading and / or establishment of the strategic theories and tools developed since the beginning of the 20th century. Texts that usually discuss management and history outline only the Industrial Revolution or the transition from feudalism to capitalism, underestimating other historical forces that offer additional explanations to the evolution of strategic thinking. As a result of an extensive bibliographical research, we were able to identify four periods where the strategic theories developed reveal suitable responses to the challenges created by the environment: in the first one (1900-1938, strategy is concerned with organization and control of business activities, resembling the ideas developed by Scientific Administration; in the second period (1939-1964, strategic planning is formalized and the area is broadly recognized; the next decades (1965-1989 are characterized by competition and uncertainty, making strategy focus on problems emerged from the outside; finally, on the turn of the century (1990-2010, the unlimited information availability enhances the need for strategists’ conceptual and practical knowledge. Also, as a final contribution, we suggest two possible trends to the future of strategy.

  1. Why did Kant reject physiological explanations in his anthropology?

    Science.gov (United States)

    Sturm, Thomas

    2008-12-01

    One of Kant's central tenets concerning the human sciences is the claim that one need not, and should not, use a physiological vocabulary if one studies human cognitions, feelings, desires, and actions from the point of view of his 'pragmatic' anthropology. The claim is well known, but the arguments Kant advances for it have not been closely discussed. I argue against misguided interpretations of the claim, and I present his actual reasons in favor of it. Contemporary critics of a 'physiological anthropology' reject physiological explanations of mental states as more or less epistemologically dubious. Kant does not favor such ignorance claims--and this is for the good, since none of these claims was sufficiently justified at that time. Instead, he develops an original irrelevance thesis concerning the empirical knowledge of the physiological basis of the mind. His arguments for this claim derive from his original and, up to now, little understood criticism of a certain conception of pragmatic history, related to his anthropological insights concerning our ability to create new rules of action, the social dynamics of human action, and the relative inconstancy of human nature. The irrelevance thesis also changes his views of the goal and methodology of anthropology. Kant thereby argues for a distinctive approach in quest for a general 'science of man'.

  2. Simultaneous explanation of the RK and R (D (*)) puzzles

    Science.gov (United States)

    Bhattacharya, Bhubanjyoti; Datta, Alakabha; London, David; Shivashankara, Shanmuka

    2015-03-01

    At present, there are several hints of lepton flavor non-universality. The LHCb Collaboration has measured RK ≡ B (B+ →K+μ+μ-) / B (B+ →K+e+e-), and the BaBar Collaboration has measured R (D (*)) ≡ B (B bar →D (*) +τ-νbarτ) / B (B bar →D (*) +ℓ-νbarℓ) (ℓ = e , μ). In all cases, the experimental results differ from the standard model predictions by 2- 3 σ. Recently, an explanation of the RK puzzle was proposed in which new physics (NP) generates a neutral-current operator involving only third-generation particles. Now, assuming the scale of NP is much larger than the weak scale, this NP operator must be made invariant under the full SU (3)C × SU (2)L × U(1)Y gauge group. In this Letter, we note that, when this is done, a new charged-current operator can appear, and this can explain the R (D (*)) puzzle. A more precise measurement of the double ratio R (D) / R (D*) can rule out this model.

  3. Method and metaphysics in Clements's and Gleason's ecological explanations.

    Science.gov (United States)

    Eliot, Christopher

    2007-03-01

    To generate explanatory theory, ecologists must wrestle with how to represent the extremely many, diverse causes behind phenomena in their domain. Early twentieth-century plant ecologists Frederic E. Clements and Henry A. Gleason provide a textbook example of different approaches to explaining vegetation, with Clements allegedly committed, despite abundant exceptions, to a law of vegetation, and Gleason denying the law in favor of less organized phenomena. However, examining Clements's approach to explanation reveals him not to be expressing a law, and instead to be developing an explanatory structure without laws, capable of progressively integrating causal complexity. Moreover, Clements and Gleason largely agree on the causes of vegetation; but, since causal understanding here underdetermines representation, they differ on how to integrate recognized causes into general theory--that is, in their methodologies. Observers of the case may have mistakenly assumed that scientific representation across the disciplines typically aims at laws like Newton's, and that representations always reveal scientists' metaphysical commitments. Ironically, in the present case, this assumption seems to have been made even by observers who regard Clements as nai ve for his alleged commitment to an ecological law.

  4. Vigorous convection as the explanation for Pluto's polygonal terrain.

    Science.gov (United States)

    Trowbridge, A J; Melosh, H J; Steckloff, J K; Freed, A M

    2016-06-02

    Pluto's surface is surprisingly young and geologically active. One of its youngest terrains is the near-equatorial region informally named Sputnik Planum, which is a topographic basin filled by nitrogen (N2) ice mixed with minor amounts of CH4 and CO ices. Nearly the entire surface of the region is divided into irregular polygons about 20-30 kilometres in diameter, whose centres rise tens of metres above their sides. The edges of this region exhibit bulk flow features without polygons. Both thermal contraction and convection have been proposed to explain this terrain, but polygons formed from thermal contraction (analogous to ice-wedges or mud-crack networks) of N2 are inconsistent with the observations on Pluto of non-brittle deformation within the N2-ice sheet. Here we report a parameterized convection model to compute the Rayleigh number of the N2 ice and show that it is vigorously convecting, making Rayleigh-Bénard convection the most likely explanation for these polygons. The diameter of Sputnik Planum's polygons and the dimensions of the 'floating mountains' (the hills of of water ice along the edges of the polygons) suggest that its N2 ice is about ten kilometres thick. The estimated convection velocity of 1.5 centimetres a year indicates a surface age of only around a million years.

  5. Biological therapeutics

    National Research Council Canada - National Science Library

    Greenstein, Ben; Brook, Daniel A

    2011-01-01

    This introductory textbook covers all the main categories of biological medicines, including vaccines, hormonal preparations, drugs for rheumatoid arthritis and other connective tissue diseases, drugs...

  6. 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

  7. 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...

  8. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  9. Global environmental change: local perceptions, understandings, and explanations

    Directory of Open Access Journals (Sweden)

    Aili Pyhälä

    2016-09-01

    Full Text Available Global environmental change (GEC is an increasingly discussed phenomenon in the scientific literature as evidence of its presence and impacts continues to grow. Yet, while the documentation of GEC is becoming more readily available, local perceptions of GEC - particularly in small-scale societies - and preferences about how to deal with it, are still largely overlooked. Local knowledge and perceptions of GEC are important in that agents make decisions (including on natural resource management based on individual perceptions. We carried out a systematic literature review that aims to provide an exhaustive state-of-the-art of the degree to and manner in which the study of local perceptions of change are being addressed in GEC research. We reviewed 126 articles found in peer-reviewed journals (between 1998 and 2014 that address local perceptions of GEC. We used three particular lenses of analysis that are known to influence local perceptions, namely (i cognition, (ii culture and knowledge, and (iii possibilities for adaptation.We present our findings on the geographical distribution of the current research, the most common changes reported, perceived drivers and impacts of change, and local explanations and evaluations of change and impacts. Overall, we found the studies to be geographically biased, lacking methodological reporting, mostly theory based with little primary data, and lacking of indepth analysis of the psychological and ontological influences in perception and implications for adaptation. We provide recommendations for future GEC research and propose the development of a "meta-language" around adaptation, perception, and mediation to encourage a greater appreciation and understanding of the diversity around these phenomena across multiple scales, and improved codesign and facilitation of locally relevant adaptation and mitigation strategies.

  10. 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...

  11. 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.

  12. Computational biology

    DEFF Research Database (Denmark)

    Hartmann, Lars Røeboe; Jones, Neil; Simonsen, Jakob Grue

    2011-01-01

    Computation via biological devices has been the subject of close scrutiny since von Neumann’s early work some 60 years ago. In spite of the many relevant works in this field, the notion of programming biological devices seems to be, at best, ill-defined. While many devices are claimed or proved t...

  13. Mesoscopic biology

    Indian Academy of Sciences (India)

    In this paper we present a qualitative outlook of mesoscopic biology where the typical length scale is of the order of nanometers and the energy scales comparable to thermal energy. Novel biomolecular machines, governed by coded information at the level of DNA and proteins, operate at these length scales in biological ...

  14. 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.

  15. 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.

  16. The SAFRR Tsunami Scenario: Improving Resilience for California from a Plausible M9 Earthquake near the Alaska Peninsula

    Science.gov (United States)

    Ross, S.; Jones, L.; Wilson, R. I.; Bahng, B.; Barberopoulou, A.; Borrero, J. C.; Brosnan, D.; Bwarie, J.; Geist, E. L.; Johnson, L.; Kirby, S. H.; Knight, W.; Long, K.; Lynett, P. J.; Miller, K.; Mortensen, C. E.; Nicolsky, D.; Oglesby, D. D.; Perry, S. C.; Plumlee, G. S.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Suleimani, E.; Thio, H. K.; Titov, V.; Wein, A. M.; Whitmore, P.; Wood, N. J.

    2013-12-01

    The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an Mw9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. We present the likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California associated with the tsunami scenario. The intended users are those who must make mitigation decisions before and rapid decisions during future tsunamis. Around a half million people would be present in the scenario's inundation area in residences, businesses, public venues, parks and beaches. Evacuation would likely be ordered for the State of California's maximum mapped tsunami inundation zone, evacuating an additional quarter million people from residences and businesses. Some island and peninsula communities would face particular evacuation challenges because of limited access options and short warning time, caused by the distance between Alaska and California. Evacuations may also be a challenge for certain dependent-care populations. One third of the boats in California's marinas could be damaged or sunk, costing at least 700 million in repairs to boats and docks, and potentially much more to address serious issues due to sediment transport and environmental contamination. Fires would likely start at many sites where fuel and petrochemicals are stored in ports and marinas. Tsunami surges and bores may travel several miles inland up coastal rivers. Debris clean-up and recovery of inundated and damaged areas will take days, months, or years depending on the severity of impacts and the available resources for recovery. The Ports of Los Angeles and Long Beach (POLA/LB) would be shut down for a miniμm of two days due to strong currents. Inundation of dry land in the ports would result in 100 million damages to cargo and additional

  17. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  18. 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

  19. 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.

  20. 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

  1. Biological desulfurisation

    Energy Technology Data Exchange (ETDEWEB)

    Arena, B.J. [UOP LLC (United States); Benschop, A.; Janssen, A. [Paques Natural Solutions (Netherlands); Kijlstra, S. [Shell Global Solutions (Netherlands)

    2001-03-01

    This article focuses on the biological THIOPAQ process for removing hydrogen sulphide from refinery gases and recovering elemental sulphur. Details are given of the process which absorbs hydrogen sulphide-containing gas in alkaline solution prior to oxidation of the dissolved sulphur to elemental sulphur in a THIOPAQ aerobic biological reactor, with regeneration of the caustic solution. Sulphur handling options including sulphur wash, the drying of the sulphur cake, and sulphur smelting by pressure liquefaction are described. Agricultural applications of the biologically recovered sulphur, and application of the THIOPAQ process to sulphur recovery are discussed.

  2. 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 ...

  3. Systems Biology

    Indian Academy of Sciences (India)

    IAS Admin

    study and understand the function of biological systems, particu- larly, the response of such .... understand the organisation and behaviour of prokaryotic sys- tems. ... relationship of the structure of a target molecule to its ability to bind a certain ...

  4. 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.

  5. 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…

  6. 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…

  7. 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…

  8. 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.…

  9. 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...

  10. 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…

  11. 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.

  12. 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.

  13. 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…

  14. 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…

  15. 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

  16. 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.

  17. 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…

  18. 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…

  19. 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…

  20. 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.

  1. 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...

  2. 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…

  3. 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)

  4. Quantum and Multidimensional Explanations in a Neurobiological Context of Mind.

    Science.gov (United States)

    Korf, Jakob

    2015-08-01

    This article examines the possible relevance of physical-mathematical multidimensional or quantum concepts aiming at understanding the (human) mind in a neurobiological context. Some typical features of the quantum and multidimensional concepts are briefly introduced, including entanglement, superposition, holonomic, and quantum field theories. Next, we consider neurobiological principles, such as the brain and its emerging (physical) mind, evolutionary and ontological origins, entropy, syntropy/neg-entropy, causation, and brain energy metabolism. In many biological processes, including biochemical conversions, protein folding, and sensory perception, the ubiquitous involvement of quantum mechanisms is well recognized. Quantum and multidimensional approaches might be expected to help describe and model both brain and mental processes, but an understanding of their direct involvement in mental activity, that is, without mediation by molecular processes, remains elusive. More work has to be done to bridge the gap between current neurobiological and physical-mathematical concepts with their associated quantum-mind theories. © The Author(s) 2014.

  5. Sustainable development in the EU: a political and economic explanation

    International Nuclear Information System (INIS)

    Creaco, Salvo

    2005-01-01

    envisaged when the recent European environmental policy was adopted. With the inevitable consequence that the most common environmental policy solution had frequently continued to be direct regulations. The scant progress in widening the range of instruments for control and behavioural change confirms the existence of a large disagreement between the normative prescriptions of economic theory and decisions effectively taken within the political process. If a large divergence between theory and practices often prevails, the relevant issue is then to understand why ED and Member States have failed to refer to the proposed wider box of instruments. In this direction, this paper points out the usefulness of the contribution that public choice theory can provide for understanding why particular environmental instruments are actually adopted and implemented. According to the individualistic approach of public choice, the paper deals with the issue concerning the choice and implementation of environmental policy tools through the analysis of the functioning of two strictly connected markets: the political market and the para-political market, and tries to give an explanation as to why in representative democracies, in which forces may be identified as demand and supply, an incentive-oriented environmental policy has many difficulties of being implemented [it

  6. 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.

  7. 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.

  8. [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.

  9. [Biological agents].

    Science.gov (United States)

    Amano, Koichi

    2009-03-01

    There are two types of biological agents for the treatment of rheumatoid arthritis (RA); monoclonal antibodies and recombinant proteins. Among the latter, etanercept, a recombinant fusion protein of soluble TNF receptor and IgG was approved in 2005 in Japan. The post-marketing surveillance of 13,894 RA patients revealed the efficacy and safety profiles of etanercept in the Japanese population, as well as overseas studies. Abatacept, a recombinant fusion protein of CTLA4 and IgG, is another biological agent for RA. Two clinical trials disclosed the efficacy of abatacept for difficult-to-treat patients: the AIM for MTX-resistant cases and the ATTAIN for patients who are resistant to anti-TNF. The ATTEST trial suggested abatacept might have more acceptable safety profile than infliximab. These biologics are also promising for the treatment of RA for not only relieving clinical symptoms and signs but retarding structural damage.

  10. Biological preconcentrator

    Science.gov (United States)

    Manginell, Ronald P [Albuquerque, NM; Bunker, Bruce C [Albuquerque, NM; Huber, Dale L [Albuquerque, NM

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  11. A physical explanation of the lognormality of pollutant concentrations

    International Nuclear Information System (INIS)

    Ott, W.R.

    1990-01-01

    Investigators in different environmental fields have reported that the concentrations of various measured substances have frequency distributions that are lognormal, or nearly so. That is, when the logarithms of the observed concentrations are plotted as a frequency distribution, the resulting distribution is approximately normal, or Gaussian, over much of the observed range. Examples include radionuclides in soil, pollutants in ambient air, indoor air quality, trace metals in streams, metals in biological tissue, calcium in human remains. The ubiquity of the lognormal distribution in environmental processes is surprising and has not been adequately explained, since common processes in nature (for example, computation of the mean and the analysis of error) usually give rise to distributions that are normal rather than lognormal. This paper takes the first step toward explaining why lognormal distributions can arise naturally from certain physical processes that are analogous to those found in the environment. In this paper, these processes are treated mathematically, and the results are illustrated in a laboratory beaker experiment that is simulated on the computer

  12. Psychogenic Explanations of Physical Illness: Time to Examine the Evidence.

    Science.gov (United States)

    Wilshire, Carolyn E; Ward, Tony

    2016-09-01

    In some patients with chronic physical complaints, detailed examination fails to reveal a well-recognized underlying disease process. In this situation, the physician may suspect a psychological cause. In this review, we critically evaluated the evidence for this causal claim, focusing on complaints presenting as neurological disorders. There were four main conclusions. First, patients with these complaints frequently exhibit psychopathology but not consistently more often than patients with a comparable "organic" diagnosis, so a causal role cannot be inferred. Second, these patients report a high incidence of adverse life experiences, but again, there is insufficient evidence to indicate a causal role for any particular type of experience. Third, although psychogenic illnesses are believed to be more responsive to psychological interventions than comparable "organic" illnesses, there is currently no evidence to support this claim. Finally, recent evidence suggests that biological and physical factors play a much greater causal role in these illnesses than previously believed. We conclude that there is currently little evidential support for psychogenic theories of illness in the neurological domain. In future research, researchers need to take a wider view concerning the etiology of these illnesses. © The Author(s) 2016.

  13. The Fragility of Individual-Based Explanations of Social Hierarchies: A Test Using Animal Pecking Orders

    Science.gov (United States)

    2016-01-01

    The standard approach in accounting for hierarchical differentiation in biology and the social sciences considers a hierarchy as a static distribution of individuals possessing differing amounts of some valued commodity, assumes that the hierarchy is generated by micro-level processes involving individuals, and attempts to reverse engineer the processes that produced the hierarchy. However, sufficient experimental and analytical results are available to evaluate this standard approach in the case of animal dominance hierarchies (pecking orders). Our evaluation using evidence from hierarchy formation in small groups of both hens and cichlid fish reveals significant deficiencies in the three tenets of the standard approach in accounting for the organization of dominance hierarchies. In consequence, we suggest that a new approach is needed to explain the organization of pecking orders and, very possibly, by implication, for other kinds of social hierarchies. We develop an example of such an approach that considers dominance hierarchies to be dynamic networks, uses dynamic sequences of interaction (dynamic network motifs) to explain the organization of dominance hierarchies, and derives these dynamic sequences directly from observation of hierarchy formation. We test this dynamical explanation using computer simulation and find a good fit with actual dynamics of hierarchy formation in small groups of hens. We hypothesize that the same dynamic sequences are used in small groups of many other animal species forming pecking orders, and we discuss the data required to evaluate our hypothesis. Finally, we briefly consider how our dynamic approach may be generalized to other kinds of social hierarchies using the example of the distribution of empty gastropod (snail) shells occupied in populations of hermit crabs. PMID:27410230

  14. Working conditions in the explanation of occupational inequalities in sickness absence in the French SUMER study.

    Science.gov (United States)

    Niedhammer, Isabelle; Lesuffleur, Thomas; Memmi, Sarah; Chastang, Jean-François

    2017-12-01

    Explanations of social inequalities in sickness absence are lacking in the literature. Our objectives were to evaluate the contribution of various occupational exposures in explaining these inequalities in a national representative sample of employees. The study was based on the cross-sectional sample of the SUMER 2010 survey that included 46 962 employees, 26 883 men and 20 079 women. Both sickness absence spells and days within the last 12 months, as health indicators, were studied. Occupation was used as a marker of social position. The study included both psychosocial work factors (variables related to the classical job strain model, psychological demands, decision latitude, social support and understudied variables related to reward, job insecurity, job promotion, esteem, working time/hours and workplace violence) and occupational exposures of chemical, biological, physical and biomechanical nature. Weighted age-adjusted Poisson and negative binomial regression analyses were performed. Strong occupational differences were found for sickness absence spells and days and for exposure to most work factors. Psychosocial work factors contributed to explain occupational differences in sickness absence spells, and the contributing factors were: decision latitude, social support, reward, shift work and workplace violence. Physical exposure, particularly noise, and biomechanical exposure were also found to be contributing factors. Almost no work factor was found to contribute to occupational differences in sickness absence days. Preventive measures at the workplace oriented towards low-skilled occupational groups and both psychosocial work factors and other occupational exposures may be beneficial to reduce sickness absence spells and occupational differences in this outcome. © The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  15. Neural nets for the plausibility check of measured values in the integrated measurement and information system for the surveillance of environmental radioactivity (IMIS)

    International Nuclear Information System (INIS)

    Haase, G.

    2003-01-01

    Neural nets to the plausibility check of measured values in the ''integrated measurement and information system for the surveillance of environmental radioactivity, IMIS'' is a research project supported by the Federal Minister for the Environment, Nature Conservation and Nuclear Safety. A goal of this project was the automatic recognition of implausible measured values in the data base ORACLE, which measured values from surveillance of environmental radioactivity of most diverse environmental media contained. The conversion of this project [ 1 ] was realized by institut of logic, complexity and deduction systems of the university Karlsruhe under the direction of Professor Dr. Menzel, Dr. Martin Riedmueller and Martin Lauer. (orig.)

  16. 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

  17. Life Sciences—Life Writing: PTSD as a Transdisciplinary Entity between Biomedical Explanation and Lived Experience

    Directory of Open Access Journals (Sweden)

    Norbert W. Paul

    2015-12-01

    Full Text Available Since the second half of the 20th century, the life sciences have become one of the dominant explanatory models for almost every aspect of human life. Hand in hand with biomedical developments and technologies, the life sciences are constantly shaping and reshaping human lives and changing human biographies in manifold ways. The orientation towards life sciences and biomedicine from the very beginning to the end of human life is driven by the utopian notion that all forms of contingency could be technologically and medically controlled. This paper addresses the interrelatedness of life sciences and human biographies in a field where contingency and risk become essential and existential parts of lived experience: post-traumatic stress disorder (PTSD. On the one hand, this diagnostic entity is related to (neuro-biological underpinnings of (a lack of psychic resilience as well as to those of contemporary pharmacotherapy. On the other hand, PTSD is also understood as based on a traumatic life event, which can be accessed through and addressed by talk therapy, particularly narrative exposure therapy (NET. We argue that a novel focus on concepts of narrativity will generate pathways for an interdisciplinary understanding of PTSD by linking biological underpinnings from neurobiological findings, to brain metabolism and pharmacotherapy via the interface of psychotherapy and the specific role of narratives to the lived experience of patients and vice versa. The goal of our study is to demonstrate why therapies such as psychotherapy or pharmacotherapy are successful in controlling the disease burden of PTSD to some extent, but the restitutio ad integrum, the reestablishing of the bodily and psychic integrity remains out of reach for most PTSD patients. As a test case, we discuss the complementary methods of Traditional Chinese Medicine (TCM and the established procedures of talk therapy (NET to show how a methodological focus on narratives enhanced by

  18. Environmental biology

    International Nuclear Information System (INIS)

    Tschumi, P.A.

    1981-01-01

    Environmental biology illustrates the functioning of ecosystems and the dynamics of populations with many examples from limnology and terrestrial ecology. On this basis, present environmental problems are analyzed. The present environmental crisis is seen as a result of the failure to observe ecological laws. (orig.) [de

  19. Biological timekeeping

    DEFF Research Database (Denmark)

    Lloyd, David

    2016-01-01

    , the networks that connect differenttime domains and the oscillations, rhythms and biological clocks that coordinate andsynchronise the complexity of the living state.“It is the pattern maintained by this homeostasis, which is the touchstone ofour personal identity. Our tissues change as we live: the food we...

  20. Scaffolded biology.

    Science.gov (United States)

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  1. Biological digestion

    International Nuclear Information System (INIS)

    Rosevear, A.

    1988-01-01

    This paper discusses the biological degradation of non-radioactive organic material occurring in radioactive wastes. The biochemical steps are often performed using microbes or isolated enzymes in combination with chemical steps and the aim is to oxidise the carbon, hydrogen, nitrogen and sulphur to their respective oxides. (U.K.)

  2. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  3. Cortically-controlled population stochastic facilitation as a plausible substrate for guiding sensory transfer across the thalamic gateway.

    Directory of Open Access Journals (Sweden)

    Sébastien Béhuret

    Full Text Available The thalamus is the primary gateway that relays sensory information to the cerebral cortex. While a single recipient cortical cell receives the convergence of many principal relay cells of the thalamus, each thalamic cell in turn integrates a dense and distributed synaptic feedback from the cortex. During sensory processing, the influence of this functional loop remains largely ignored. Using dynamic-clamp techniques in thalamic slices in vitro, we combined theoretical and experimental approaches to implement a realistic hybrid retino-thalamo-cortical pathway mixing biological cells and simulated circuits. The synaptic bombardment of cortical origin was mimicked through the injection of a stochastic mixture of excitatory and inhibitory conductances, resulting in a gradable correlation level of afferent activity shared by thalamic cells. The study of the impact of the simulated cortical input on the global retinocortical signal transfer efficiency revealed a novel control mechanism resulting from the collective resonance of all thalamic relay neurons. We show here that the transfer efficiency of sensory input transmission depends on three key features: i the number of thalamocortical cells involved in the many-to-one convergence from thalamus to cortex, ii the statistics of the corticothalamic synaptic bombardment and iii the level of correlation imposed between converging thalamic relay cells. In particular, our results demonstrate counterintuitively that the retinocortical signal transfer efficiency increases when the level of correlation across thalamic cells decreases. This suggests that the transfer efficiency of relay cells could be selectively amplified when they become simultaneously desynchronized by the cortical feedback. When applied to the intact brain, this network regulation mechanism could direct an attentional focus to specific thalamic subassemblies and select the appropriate input lines to the cortex according to the descending

  4. 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…

  5. 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.

  6. 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

  7. 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…

  8. 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 ...

  9. 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...

  10. 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...

  11. 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.

  12. 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 ...

  13. 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...

  14. Biological radioprotector

    International Nuclear Information System (INIS)

    Stefanescu, Ioan; Titescu, Gheorghe; Tamaian, Radu; Haulica, Ion; Bild, Walther

    2002-01-01

    According to the patent description, the biological radioprotector is deuterium depleted water, DDW, produced by vacuum distillation with an isotopic content lower than natural value. It appears as such or in a mixture with natural water and carbon dioxide. It can be used for preventing and reducing the ionizing radiation effects upon humans or animal organisms, exposed therapeutically, professionally or accidentally to radiation. The most significant advantage of using DDW as biological radioprotector results from its way of administration. Indeed no one of the radioprotectors currently used today can be orally administrated, what reduces the patients' compliance to prophylactic administrations. The biological radioprotector is an unnoxious product obtained from natural water, which can be administrated as food additive instead of drinking water. Dose modification factor is according to initial estimates around 1.9, what is a remarkable feature when one takes into account that the product is toxicity-free and side effect-free and can be administrated prophylactically as a food additive. A net radioprotective action of the deuterium depletion was evidenced experimentally in laboratory animals (rats) hydrated with DDW of 30 ppm D/(D+H) concentration as compared with normally hydrated control animals. Knowing the effects of irradiation and mechanisms of the acute radiation disease as well as the effects of administration of radiomimetic chemicals upon cellular lines of fast cell division, it appears that the effects of administrating DDW result from stimulation of the immunity system. In conclusion, the biological radioprotector DDW presents the following advantages: - it is obtained from natural products without toxicity; - it is easy to be administrated as a food additive, replacing the drinking water; - besides radioprotective effects, the product has also immunostimulative and antitumoral effects

  15. 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.

  16. 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.

  17. 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.

  18. Marine biology

    International Nuclear Information System (INIS)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  19. 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).

  20. Structural Biology Fact Sheet

    Science.gov (United States)

    ... NIGMS NIGMS Home > Science Education > Structural Biology Structural Biology Tagline (Optional) Middle/Main Content Area PDF Version (688 KB) Other Fact Sheets What is structural biology? Structural biology is the study of how biological ...

  1. 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…

  2. 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…

  3. 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

  4. 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

  5. Biology Branch

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, W F

    1974-12-31

    Progress is reported on the following studies in biochemistry and molecular biology: study of long pyrimidine polynucleotides in DNA; isolation of thymine dimers from Schizosaccharomyces pombe; thermal stability of high molecular weight RNA; nucleases of Micrococcus radiodurans; effect of ionizing radiation on M. radiodurans cell walls and cell membranes; chemical modification of nucleotides; exonucleases of M. radiodurans; and enzymatic basis of repair of radioinduced damage in M. radiodurans. Genetics, development, and population studies include repair pathways and mutation induction in yeast; induction of pure mutant clones in yeast; radiosensitivity of bacteriophage T4; polyacrylamide gel electrophoresis of bacteriophage T4; radiation genetics of Dahibominus; and radiation studies on bitting flies. (HLW)

  6. 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.

  7. 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.

  8. 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

  9. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Biological effects

    International Nuclear Information System (INIS)

    Trott, K.R.

    1973-01-01

    Following an introduction into the field of cellular radiation effect considering the most important experimental results, the biological significance of the colony formation ability is brought out. The inactivation concept of stem cells does not only prove to be good, according to the present results, in the interpretation of the pathogenesis of acute radiation effects on moult tissue, it also enables chronicle radiation injuries to be interpreted through changes in the fibrous part of the organs. Radiation therapy of tumours can also be explained to a large extent by the radiation effect on the unlimited reproductiveness of tumour cells. The more or less similar dose effect curves for healthy and tumour tissue in practice lead to intermittent irradiation. The dependence of the intermittent doses and intervals on factors such as Elkind recovery, synchronisation, redistribution, reoxygenation, repopulation and regeneration are reviewed. (ORU/LH) [de

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Creating biological nanomaterials using synthetic biology

    International Nuclear Information System (INIS)

    Rice, MaryJoe K; Ruder, Warren C

    2014-01-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems. (review)

  1. Creating biological nanomaterials using synthetic biology.

    Science.gov (United States)

    Rice, MaryJoe K; Ruder, Warren C

    2014-02-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. Plausibility Arguments and Universal Gravitation

    Science.gov (United States)

    Cunha, Ricardo F. F.; Tort, A. C.

    2017-01-01

    Newton's law of universal gravitation underpins our understanding of the dynamics of the Solar System and of a good portion of the observable universe. Generally, in the classroom or in textbooks, the law is presented initially in a qualitative way and at some point during the exposition its mathematical formulation is written on the blackboard…

  7. Towards a more plausible dragon

    Science.gov (United States)

    Efthimiou, Costas

    2014-08-01

    Wizards, mermaids, dragons and aliens. Walking, running, flying and space travel. A hi-tech elevator, a computer, a propulsion engine and a black hole. What do all of these things have in common? This might seem like a really hard brainteaser but the answer is simple: they all obey the fundamental laws of our universe.

  8. Plausibility orderings in dynamic games

    NARCIS (Netherlands)

    Perea ý Monsuwé, A.

    2014-01-01

    In this paper we explore game-theoretic reasoning in dynamic games within the framework of belief revision theory. More precisely, we focus on the forward induction concept of ‘common strong belief in rationality’ (Battigalli and Siniscalchi (2002) and the backward induction concept of ‘common

  9. A Brief Introduction to Chinese Biological Biological

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chinese Biological Abstracts sponsored by the Library, the Shanghai Institutes for Biological Sciences, the Biological Documentation and Information Network, all of the Chinese Academy of Sciences, commenced publication in 1987 and was initiated to provide access to the Chinese information in the field of biology.

  10. 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.

  11. Discovery Learning, Representation, and Explanation within a Computer-Based Simulation: Finding the Right Mix

    Science.gov (United States)

    Rieber, Lloyd P.; Tzeng, Shyh-Chii; Tribble, Kelly

    2004-01-01

    The purpose of this research was to explore how adult users interact and learn during an interactive computer-based simulation supplemented with brief multimedia explanations of the content. A total of 52 college students interacted with a computer-based simulation of Newton's laws of motion in which they had control over the motion of a simple…

  12. Social Facilitation Effects by Pedagogical Conversational Agent: Lexical Network Analysis in an Online Explanation Task

    Science.gov (United States)

    Hayashi, Yugo

    2015-01-01

    The present study investigates web-based learning activities of undergraduate students who generate explanations about a key concept taught in a large-scale classroom. The present study used an online system with Pedagogical Conversational Agent (PCA), asked to explain about the key concept from different points and provided suggestions and…

  13. The Interrelations between Diagrammatic Representations and Verbal Explanations in Learning from Social Science Texts.

    Science.gov (United States)

    Guri-Rozenblit, Sarah

    1988-01-01

    Describes study that examined the instructional effectiveness of abstract diagrams and verbal explanations in learning from social science texts. The control and treatment groups of adult learners at Everyman's University (Israel) are described, verbal and visual aptitude tests are explained, and results are analyzed. (25 references) (Author/LRW)

  14. 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.

  15. 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-…

  16. 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

  17. The Role of Social Capital in the Explanation of Educational Success and Educational Inequalities

    Science.gov (United States)

    Roth, Tobias

    2013-01-01

    This article examines the role that social capital plays in school success and in the explanation of social and ethnic inequalities in the German educational system. Based on Coleman's well-known concept of social capital, different aspects of social capital are distinguished, including social network composition, parent-school interaction and…

  18. 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…

  19. Tell Me Why! Content Knowledge Predicts Process-Orientation of Math Researchers' and Math Teachers' Explanations

    Science.gov (United States)

    Lachner, Andreas; Nückles, Matthias

    2016-01-01

    In two studies, we investigated the impact of instructors' different knowledge bases on the quality of their instructional explanations. In Study 1, we asked 20 mathematics teachers (with high pedagogical content knowledge, but lower content knowledge) and 15 mathematicians (with lower pedagogical content knowledge, but high content knowledge) to…

  20. Examining Alternative Explanations of the Covariation of ADHD and Anxiety Symptoms in Children: A Community Study

    Science.gov (United States)

    Baldwin, Jennifer S.; Dadds, Mark R.

    2008-01-01

    Attention-deficit hyperactivity disorder (ADHD) is comorbid with a range of other disorders, including anxiety disorders. The aim was to examine different explanations for the covariation of these symptom domains in children according to the framework provided by (Lilienfeld, S. O. Comorbidity between and within childhood externalizing and…

  1. 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.

  2. Students' Reasoning When Tackling Electric Field and Potential in Explanation of DC Resistive Circuits

    Science.gov (United States)

    Leniz, Ane; Zuza, Kristina; Guiasola, Jenaro

    2017-01-01

    This study examines the causal reasoning that university students use to explain how dc circuits work. We analyze how students use the concepts of electric field and potential difference in their explanatory models of dc circuits, and what kinds of reasoning they use at the macroscopic and microscopic levels in their explanations. This knowledge…

  3. Unraveling the Effects of Critical Thinking Instructions, Practice, and Self-Explanation on Students' Reasoning Performance

    Science.gov (United States)

    Heijltjes, Anita; van Gog, Tamara; Leppink, Jimmie; Paas, Fred

    2015-01-01

    Acquisition of critical thinking skills is considered an important goal in higher education, but it is still unclear which specific instructional techniques are effective for fostering it. The main aim of this study was to unravel the impact of critical thinking instructions, practice, and self-explanation prompts during practice, on students'…

  4. Rational Learning and Information Sampling: On the "Naivety" Assumption in Sampling Explanations of Judgment Biases

    Science.gov (United States)

    Le Mens, Gael; Denrell, Jerker

    2011-01-01

    Recent research has argued that several well-known judgment biases may be due to biases in the available information sample rather than to biased information processing. Most of these sample-based explanations assume that decision makers are "naive": They are not aware of the biases in the available information sample and do not correct for them.…

  5. Academic Performance Differences among Ethnic Groups: Do the Daily Use and Management of Time Offer Explanations?

    Science.gov (United States)

    Meeuwisse, Marieke; Born, Marise Ph.; Severiens, Sabine E.

    2013-01-01

    This explorative study describes time use and time management behaviour of ethnic minority and ethnic majority students as possible explanations for the poorer study results of ethnic minority students compared to those of majority students. We used a diary approach in a small sample to examine students' daily time use in both a lecture week…

  6. What determines the informativeness of firms' explanations for deviations from the Dutch corporate governance code?

    NARCIS (Netherlands)

    Hooghiemstra, R.B.H.

    2012-01-01

    The comply-or-explain principle is a common feature of corporate governance codes. While prior studies investigated compliance with corporate governance codes as well as the effects of compliance on firm behaviour and performance, explanations for deviations from a corporate governance code remain

  7. 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…

  8. 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...

  9. 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

  10. 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.

  11. Experience and Explanation: Using Videogames to Prepare Students for Formal Instruction in Statistics

    Science.gov (United States)

    Arena, Dylan A.; Schwartz, Daniel L.

    2014-01-01

    Well-designed digital games can deliver powerful experiences that are difficult to provide through traditional instruction, while traditional instruction can deliver formal explanations that are not a natural fit for gameplay. Combined, they can accomplish more than either can alone. An experiment tested this claim using the topic of statistics,…

  12. An Explanation of the Relationship between Instructor Humor and Student Learning: Instructional Humor Processing Theory

    Science.gov (United States)

    Wanzer, Melissa B.; Frymier, Ann B.; Irwin, Jeffrey

    2010-01-01

    This paper proposes the Instructional Humor Processing Theory (IHPT), a theory that incorporates elements of incongruity-resolution theory, disposition theory, and the elaboration likelihood model (ELM) of persuasion. IHPT is proposed and offered as an explanation for why some types of instructor-generated humor result in increased student…

  13. 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…

  14. Extending the Seductive Allure of Neuroscience Explanations Effect to Popular Articles about Educational Topics

    Science.gov (United States)

    Im, Soo-hyun; Varma, Keisha; Varma, Sashank

    2017-01-01

    Background: The "seductive allure of neuroscience explanations" (SANE) is the finding that people overweight psychological arguments when framed in terms of neuroscience findings. Aim: This study extended this finding to arguments concerning the application of psychological findings to educational topics. Sample Participants (n = 320)…

  15. 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

  16. The Effects of Self-Explanation and Reading Questions and Answers on Learning Computer Programming Language

    Science.gov (United States)

    Lee, Nancy

    2013-01-01

    The current study explored the differential effects of two learning strategies, self-explanation and reading questions and answers, on students' test performance in the computer programming language JavaScript. Students' perceptions toward the two strategies as to their effectiveness in learning JavaScript was also explored by examining students'…

  17. 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…

  18. Denomination, Religious Context, and Suicide : Neo-Durkheimian Multilevel Explanations Tested with Individual and Contextual Data

    NARCIS (Netherlands)

    Tubergen, Frank van; Grotenhuis, Manfred te; Ultee, Wout

    2005-01-01

    In Suicide, Durkheim found that involvement in religious communities is inversely related to suicide risk. In this article, two explanations for this relationship are examined. One is that religious networks provide support. The other is that religious communities prohibit suicide. To examine these

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. Bacterially-Associated Transcriptional Remodelling in a Distinct Genomic Subtype of Colorectal Cancer Provides a Plausible Molecular Basis for Disease Development.

    Directory of Open Access Journals (Sweden)

    Katie S Lennard

    Full Text Available The relevance of specific microbial colonisation to colorectal cancer (CRC disease pathogenesis is increasingly recognised, but our understanding of possible underlying molecular mechanisms that may link colonisation to disease in vivo remains limited. Here, we investigate the relationships between the most commonly studied CRC-associated bacteria (Enterotoxigenic Bacteroides fragilis, pks+ Escherichia coli, Fusobacterium spp., afaC+ E. coli, Enterococcus faecalis & Enteropathogenic E. coli and altered transcriptomic and methylation profiles of CRC patients, in order to gain insight into the potential contribution of these bacteria in the aetiopathogenesis of CRC. We show that colonisation by E. faecalis and high levels of Fusobacterium is associated with a specific transcriptomic subtype of CRC that is characterised by CpG island methylation, microsatellite instability and a significant increase in inflammatory and DNA damage pathways. Analysis of the significant, bacterially-associated changes in host gene expression, both at the level of individual genes as well as pathways, revealed a transcriptional remodeling that provides a plausible mechanistic link between specific bacterial colonisation and colorectal cancer disease development and progression in this subtype; these included upregulation of REG3A, REG1A and REG1P in the case of high-level colonization by Fusobacterium, and CXCL10 and BMI1 in the case of colonisation by E. faecalis. The enrichment of both E. faecalis and Fusobacterium in this CRC subtype suggests that polymicrobial colonisation of the colonic epithelium may well be an important aspect of colonic tumourigenesis.

  6. 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…

  7. 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.

  8. 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:…

  9. 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.

  10. 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

  11. 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

  12. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  13. 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

  14. 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...

  15. 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

  16. 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...

  17. Opportunities for Inquiry Science in Montessori Classrooms: Learning from a Culture of Interest, Communication, and Explanation

    Science.gov (United States)

    Rinke, Carol R.; Gimbel, Steven J.; Haskell, Sophie

    2013-08-01

    Although classroom inquiry is the primary pedagogy of science education, it has often been difficult to implement within conventional classroom cultures. This study turned to the alternatively structured Montessori learning environment to better understand the ways in which it fosters the essential elements of classroom inquiry, as defined by prominent policy documents. Specifically, we examined the opportunities present in Montessori classrooms for students to develop an interest in the natural world, generate explanations in science, and communicate about science. Using ethnographic research methods in four Montessori classrooms at the primary and elementary levels, this research captured a range of scientific learning opportunities. The study found that the Montessori learning environment provided opportunities for students to develop enduring interests in scientific topics and communicate about science in various ways. The data also indicated that explanation was largely teacher-driven in the Montessori classroom culture. This study offers lessons for both conventional and Montessori classrooms and suggests further research that bridges educational contexts.

  18. An exploration of students’ own explanations about dropout in vocational education in a danish context

    DEFF Research Database (Denmark)

    Tanggaard, Lene

    2013-01-01

    The present paper addresses the phenomenon of student dropout from vocational education in Denmark. It does so by addressing the need to critically discuss the term ‘drop-out’ taking the perspective of students’ own reflections on the topic. The empirical findings indicate that dropout...... is considered in terms of two very different, but intersecting broad explanations voiced by students themselves: (1) as something created in educational institutions in various situations, such as when teachers spend more time and resources on the more affluent, quick-witted and clever students or when...... there is a lack of trainee places and (2) an act resulting from individual initiative and or a lack of perseverance. Secondly, and as a result of analysing the possible interplay between and differences related to the above two broad explanations, the empirical material reveals alternatives to the dropout concept...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

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

    Science.gov (United States)

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

    1988-01-01

    The complexity introduced by the geomagnetic field in several regions of a coaxial gun plasma device is described. 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. The results indicate that the device should be aligned along the direction of the local geomagnetic field or enclosed in a mu-metal shield.

  4. Taste, Salt Consumption, and Local Explanations around Hypertension in a Rural Population in Northern Peru

    OpenAIRE

    Pesantes, M. Amalia; Diez-Canseco, Francisco; Bernab?-Ortiz, Antonio; Ponce-Lucero, Vilarmina; Miranda, J. Jaime

    2017-01-01

    Interventions to promote behaviors to reduce sodium intake require messages tailored to local understandings of the relationship between what we eat and our health. We studied local explanations about hypertension, the relationship between local diet, salt intake, and health status, and participants? opinions about changing food habits. This study provided inputs for a social marketing campaign in Peru promoting the use of a salt substitute containing less sodium than regular salt. Qualitativ...

  5. 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.

  6. Why do firms hold so much cash? A tax-based explanation

    OpenAIRE

    C. Fritz Foley; Jay C. Hartzell; Sheridan Titman; Garry Twite

    2006-01-01

    U.S. corporations hold significant amounts of cash on their balance sheets, and these cash holdings have been justified in the existing empirical literature by transaction costs and precautionary motives. An additional explanation, considered in this study, is that U.S. multinational firms hold cash in their foreign subsidiaries because of the tax costs associated with repatriating foreign income. Consistent with this hypothesis, firms that face higher repatriation tax burdens hold higher lev...

  7. Explanation for Cancer in Rats, Mice and Humans due to Cell Phone Radiofrequency Radiation

    OpenAIRE

    Feldman, Bernard J.

    2016-01-01

    Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radiofrequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. This paper proposes the following explanation for these results. The neurons around the rat's brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radiofrequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents...

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

    OpenAIRE

    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 a...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. The individual tolerance concept is not the sole explanation for the probit dose-effect model

    Energy Technology Data Exchange (ETDEWEB)

    Newman, M.C.; McCloskey, J.T.

    2000-02-01

    Predominant methods for analyzing dose- or concentration-effect data (i.e., probit analysis) are based on the concept of individual tolerance or individual effective dose (IED, the smallest characteristic dose needed to kill an individual). An alternative explanation (stochasticity hypothesis) is that individuals do not have unique tolerances: death results from stochastic processes occurring similarly in all individuals. These opposing hypotheses were tested with two types of experiments. First, time to stupefaction (TTS) was measured for zebra fish (Brachydanio rerio) exposed to benzocaine. The same 40 fish were exposed during five trials to test if the same order for TTS was maintained among trials. The IED hypothesis was supported with a minor stochastic component being present. Second, eastern mosquitofish (Gambusia holbrooki) were exposed to sublethal or lethal NaCl concentrations until a large portion of the lethally exposed fish died. After sufficient time for recovery, fish sublethally exposed and fish surviving lethal exposure were exposed simultaneously to lethal NaCl concentrations. No statistically significant effect was found of previous exposure on survival time but a large stochastic component to the survival dynamics was obvious. Repetition of this second type of test with pentachlorophenol also provided no support for the IED hypothesis. The authors conclude that neither hypothesis alone was the sole or dominant explanation for the lognormal (probit) model. Determination of the correct explanation (IED or stochastic) or the relative contributions of each is crucial to predicting consequences to populations after repeated or chronic exposures to any particular toxicant.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Explanations of sleep paralysis among Egyptian college students and the general population in Egypt and Denmark.

    Science.gov (United States)

    Jalal, Baland; Simons-Rudolph, Joseph; Jalal, Bamo; Hinton, Devon E

    2014-04-01

    This cross-cultural study compared explanations of sleep paralysis (SP) in two countries and two groups with different levels of education in one country. Comparisons were made between individuals having experienced SP at least once in a lifetime from Cairo, Egypt (n = 89), Copenhagen, Denmark (n = 59), and the American University in Cairo, Egypt (n = 44). As hypothesized, participants from the general Egyptian population were more likely to endorse supernatural causal explanation of their SP compared to participants from Denmark; participants from the American University in Cairo were less likely to endorse supernatural causes of their SP compared to participants from the general Egyptian population. Moreover, participants from the American University in Cairo were marginally significantly more likely to endorse supernatural causes of their SP compared to participants from Denmark. Additionally, we explored which culturally bound explanations and beliefs about SP existed in Egypt and Denmark. We found that nearly half (48%) of the participants from the general Egyptian population believed their SP to be caused by the Jinn, a spirit-like creature with roots in Islamic tradition, which constitutes a culturally bound interpretation of the phenomenology of SP in this region of the world. Case studies are presented to illustrate these findings.

  20. 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