The Problem of Underdetermination in Model Selection

2018 ◽  
Vol 48 (1) ◽  
pp. 52-87
Author(s):  
Michael Schultz
Keyword(s):  
Lower Bound ◽  
Model Selection ◽  
Philosophy Of Science ◽  
Model Fit ◽  
New Paradigm ◽  
Conventional Model ◽  
Trade Off ◽  
Nested Models ◽  
Network Composition ◽  
The Relationship

Conventional model selection evaluates models on their ability to represent data accurately, ignoring their dependence on theoretical and methodological assumptions. Drawing on the concept of underdetermination from the philosophy of science, the author argues that uncritical use of methodological assumptions can pose a problem for effective inference. By ignoring the plausibility of assumptions, existing techniques select models that are poor representations of theory and are thus suboptimal for inference. To address this problem, the author proposes a new paradigm for inference-oriented model selection that evaluates models on the basis of a trade-off between model fit and model plausibility. By comparing the fits of sequentially nested models, it is possible to derive an empirical lower bound for the subjective plausibility of assumptions. To demonstrate the effectiveness of this approach, the method is applied to models of the relationship between cultural tastes and network composition.

KEUNTUNGAN DAN RISIKO USAHA MINI PURSE SEINE DI DESA SATHEAN

2017 ◽  
Vol 1 (2) ◽  
pp. 49-57
Author(s):  
Frischilla Pentury ◽  
Eygner Gerald Talakua ◽  
Tati Ngangun
Keyword(s):  
Business Owners ◽  
Purse Seine ◽  
Primary Data ◽  
Business Risk ◽  
New Paradigm ◽  
Risk Calculation ◽  
Business Sustainability ◽  
Profit Analysis ◽  
Business Profit ◽  
The Relationship

The low profits of mini purse seine in Sathean Village will have an impact on the business risks being carried out. The new paradigm states that the relationship between risk and profit levels is quadratic; too much risk can lead to the loss and even destruction of a business. Thus, the fisherman of mini purse seine business owners in Sathean Village needs to manage their business risk well to achieve optimum profit for business sustainability. This study aims to assess business profits and business risks. Primary data was collected on 6 fisherman owners of mini purse seine business owners in Sathean Village as respondents, conducted business profit analysis and business risk calculation based on probability density. The results showed that the business profit was Rp 241,608,203/year or Rp 196,551,994 in the peak season, Rp 41.828.721 in the medium season and Rp 3.2227.488 in the less season.In peak and less seasons, these businesses are at risk or have the opportunity to lose, while in the medium season is not risky.

scholarly journals Geocomputing, New Technologies and Historical Analysis: Tools for a Changing Planet

Proceedings ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 9
Author(s):  
Sebastiano Trevisani
Keyword(s):  
Quantitative Analysis ◽  
Philosophy Of Science ◽  
New Technologies ◽  
Historical Analysis ◽  
Holistic Approach ◽  
Research Topic ◽  
The Other ◽  
Historical Records ◽  
The Earth ◽  
The Relationship

Modern Earth Scientists need also to interact with other disciplines, apparently far from the Earth Sciences and Engineering. Disciplines related to history and philosophy of science are emblematic from this perspective. From one side, the quantitative analysis of information extracted from historical records (documents, maps, paintings, etc.) represents an exciting research topic, requiring a truly holistic approach. On the other side, epistemological and philosophy of science considerations on the relationship between geoscience and society in history are of fundamental importance for understanding past, present and future geosphere-anthroposphere interlinked dynamics.

scholarly journals A New Paradigm in the Relationship between Melatonin and Breast Cancer: Gut Microbiota Identified as a Potential Regulatory Agent

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3141
Author(s):  
Aurora Laborda-Illanes ◽  
Lidia Sánchez-Alcoholado ◽  
Soukaina Boutriq ◽  
Isaac Plaza-Andrades ◽  
Jesús Peralta-Linero ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gut Microbiota ◽  
Bacterial Population ◽  
Kynurenine Pathway ◽  
New Paradigm ◽  
Bacterial Composition ◽  
Glucuronidase Activity ◽  
The One ◽  
The Relationship ◽  
Melatonin Production

In this review we summarize a possible connection between gut microbiota, melatonin production, and breast cancer. An imbalance in gut bacterial population composition (dysbiosis), or changes in the production of melatonin (circadian disruption) alters estrogen levels. On the one hand, this may be due to the bacterial composition of estrobolome, since bacteria with β-glucuronidase activity favour estrogens in a deconjugated state, which may ultimately lead to pathologies, including breast cancer. On the other hand, it has been shown that these changes in intestinal microbiota stimulate the kynurenine pathway, moving tryptophan away from the melatonergic pathway, thereby reducing circulating melatonin levels. Due to the fact that melatonin has antiestrogenic properties, it affects active and inactive estrogen levels. These changes increase the risk of developing breast cancer. Additionally, melatonin stimulates the differentiation of preadipocytes into adipocytes, which have low estrogen levels due to the fact that adipocytes do not express aromatase. Consequently, melatonin also reduces the risk of breast cancer. However, more studies are needed to determine the relationship between microbiota, melatonin, and breast cancer, in addition to clinical trials to confirm the sensitizing effects of melatonin to chemotherapy and radiotherapy, and its ability to ameliorate or prevent the side effects of these therapies.

scholarly journals Ethical Issues in Consent for the Reuse of Data in Health Data Platforms

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Alex McKeown ◽  
Miranda Mourby ◽  
Paul Harrison ◽  
Sophie Walker ◽  
Mark Sheehan ◽  
...  
Keyword(s):  
Social Contract ◽  
Ethical Issues ◽  
Personalised Medicine ◽  
Data Reuse ◽  
Remote Access ◽  
Risk Indicators ◽  
New Paradigm ◽  
The Social ◽  
New Thinking ◽  
The Relationship

AbstractData platforms represent a new paradigm for carrying out health research. In the platform model, datasets are pooled for remote access and analysis, so novel insights for developing better stratified and/or personalised medicine approaches can be derived from their integration. If the integration of diverse datasets enables development of more accurate risk indicators, prognostic factors, or better treatments and interventions, this obviates the need for the sharing and reuse of data; and a platform-based approach is an appropriate model for facilitating this. Platform-based approaches thus require new thinking about consent. Here we defend an approach to meeting this challenge within the data platform model, grounded in: the notion of ‘reasonable expectations’ for the reuse of data; Waldron’s account of ‘integrity’ as a heuristic for managing disagreement about the ethical permissibility of the approach; and the element of the social contract that emphasises the importance of public engagement in embedding new norms of research consistent with changing technological realities. While a social contract approach may sound appealing, however, it is incoherent in the context at hand. We defend a way forward guided by that part of the social contract which requires public approval for the proposal and argue that we have moral reasons to endorse a wider presumption of data reuse. However, we show that the relationship in question is not recognisably contractual and that the social contract approach is therefore misleading in this context. We conclude stating four requirements on which the legitimacy of our proposal rests.

scholarly journals Noni fruit’s water spot appearance on the second day of harvest: a trade-off between resistance and energy

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tian Wu ◽  
Danyan Hu ◽  
Qingfen Wang
Keyword(s):  
Statistical Analysis ◽  
Molecular Level ◽  
Morinda Citrifolia ◽  
Transcriptome Data ◽  
Trade Off ◽  
Kegg Pathways ◽  
Available Energy ◽  
Climacteric Fruit ◽  
The Relationship ◽  
Insight Into

Abstract Background Noni (Morinda citrifolia Linn.) is a tropical tree that bears climacteric fruit. Previous observations and research have shown that the second day (2 d) after harvest is the most important demarcation point when the fruit has the same appearance as the freshly picked fruit (0 d); however, they are beginning to become water spot appearance. We performed a conjoint analysis of metabolome and transcriptome data for noni fruit of 0 d and 2 d to reveal what happened to the fruit at the molecular level. Genes and metabolites were annotated to KEGG pathways and the co-annotated KEGG pathways were used as a statistical analysis. Results We found 25 pathways that were significantly altered at both metabolic and transcriptional levels, including a total of 285 differentially expressed genes (DEGs) and 11 differential metabolites through an integrative analysis of transcriptomics and metabolomics. The energy metabolism and pathways originating from phenylalanine were disturbed the most. The upregulated resistance metabolites and genes implied the increase of resistance and energy consumption in the postharvest noni fruit. Most genes involved in glycolysis were downregulated, further limiting the available energy. This lack of energy led noni fruit to water spot appearance, a prelude to softening. The metabolites and genes related to the resistance and energy interacted and restricted each other to keep noni fruit seemingly hard within two days after harvest, but actually the softening was already unstoppable. Conclusions This study provides a new insight into the relationship between the metabolites and genes of noni fruit, as well as a foundation for further clarification of the post-ripening mechanism in noni fruit.

scholarly journals Optimizing Consistency and Coverage in Configurational Causal Modeling

2021 ◽  
pp. 004912412199555
Author(s):  
Michael Baumgartner ◽  
Mathias Ambühl
Keyword(s):  
Model Selection ◽  
Causal Inference ◽  
Comparative Methods ◽  
Causal Models ◽  
Causal Modeling ◽  
Model Fit

Consistency and coverage are two core parameters of model fit used by configurational comparative methods (CCMs) of causal inference. Among causal models that perform equally well in other respects (e.g., robustness or compliance with background theories), those with higher consistency and coverage are typically considered preferable. Finding the optimally obtainable consistency and coverage scores for data [Formula: see text], so far, is a matter of repeatedly applying CCMs to [Formula: see text] while varying threshold settings. This article introduces a procedure called ConCovOpt that calculates, prior to actual CCM analyses, the consistency and coverage scores that can optimally be obtained by models inferred from [Formula: see text]. Moreover, we show how models reaching optimal scores can be methodically built in case of crisp-set and multi-value data. ConCovOpt is a tool, not for blindly maximizing model fit, but for rendering transparent the space of viable models at optimal fit scores in order to facilitate informed model selection—which, as we demonstrate by various data examples, may have substantive modeling implications.

Effects of light, temperature and population variability on the germination of seven Spanish pines

2002 ◽  
Vol 12 (4) ◽  
pp. 261-271 ◽  
Author(s):  
A. Escudero ◽  
F. Pérez-García ◽  
A. L. Luzuriaga
Keyword(s):  
Habitat Preferences ◽  
Population Variability ◽  
Nested Models ◽  
Germination Response ◽  
Germination Characteristics ◽  
Different Populations ◽  
Effects Of Temperature ◽  
Germination Traits ◽  
The Relationship ◽  
Pine Species

AbstractMost Pinus species are obligate seeders. Thus, knowledge of germination characteristics can help in the understanding, prediction and manipulation of the regeneration and dynamics of pine forests. Seven pine species with contrasting habitat preferences and different genetic pairwise distances are present in the Iberian Peninsula and the Canary Islands: P. halepensis, P. nigra, P. pinaster, P. pinea, P. sylvestris, P. uncinata and P. canariensis. These seven pine species comprise an exceptional experimental set to test some questions related to germination traits, such as: (1) What are the effects of light and temperature on germination, taking into account interpopulation variability? (2) Is there any association of germination traits with habitat (montane versus lowland) preferences? and (3) What is the relationship between germination traits and the genetic distance between pine species? P. nigra, P. sylvestris and P. uncinata seeds showed faster germination rates. Seeds of P. nigra and P. sylvestris reached high total germination percentages in every temperature and light treatment, suggesting an opportunistic germination strategy. Unlike montane pines, lowland pines did show significant effects of temperature on germination response: final germination was higher between 15°C and 20°C than at warmer and alternating temperatures. Relatively low temperatures associated with the winter rainy season would favour germination of most of these species. Nested models showed that population variability was the main source of variation in germination response. Thus, there is no phylogenetic control of the germination response and, surprisingly, germination traits were not related to habitat preferences. As a consequence, we believe that studies of the germination characteristics of a pine species should consider different populations.

scholarly journals Scientific Practice and the Epistemology of Governing Laws

2019 ◽  
Vol 5 (2) ◽  
pp. 174-188 ◽  
Author(s):  
TYLER HILDEBRAND
Keyword(s):  
British Journal ◽  
Philosophy Of Science ◽  
Scientific Practice ◽  
Laws Of Nature ◽  
General Interest ◽  
Natural Properties ◽  
Fundamental Properties ◽  
Epistemic Access ◽  
The Relationship

AbstractThis article is concerned with the relationship between scientific practice and the metaphysics of laws of nature and natural properties. I begin by examining an argument by Michael Townsen Hicks and Jonathan Schaffer (‘Derivative Properties in Fundamental Laws,’ British Journal for the Philosophy of Science 2017) that an important feature of scientific practice—namely, that scientists sometimes invoke non-fundamental properties in fundamental laws—is incompatible with metaphysical theories according to which laws govern. I respond to their argument by developing an epistemology for governing laws that is grounded in scientific practice. This epistemology is of general interest for non-Humean theories of laws, for it helps to explain our epistemic access to non-Humean theoretical entities such as governing laws or fundamental powers.

scholarly journals Teleworking in Times of COVID-19: Effects on the Acquisition of Personal Resources

2021 ◽  
Vol 12 ◽  
Author(s):  
Manuel Pulido-Martos ◽  
Daniel Cortés-Denia ◽  
Esther Lopez-Zafra
Keyword(s):  
Social Support ◽  
Model Fit ◽  
Personal Resources ◽  
Psychosocial Work ◽  
Online Questionnaire ◽  
Personal Resource ◽  
Face To Face ◽  
The Face ◽  
Labor Resources ◽  
The Relationship

The COVID-19 pandemic has forced many employees to introduce different degrees of teleworking, leading to a transformation of the psychosocial work environment. In this study, we analyzed whether the relationship between a labor resource, social support, and a personal resource, vigor at work, is affected by the work modality (face-to-face, hybrid that includes face-to-face work and telework time, and telework caused by the current pandemic situation). Five hundred and forty-three employees answered an online questionnaire about their perceptions of the levels of social support, vigor experienced in the last month, and work modality. Seniority in the organization and the gender of the employees were controlled for. The model fit was significant [F(7, 535) = 20.816, p < 0.001], accounting for 21% of the variation in vigor (R2 = 0.21). The interaction was also significant [F(2, 535) = 4.13, p < 0.05], with an increase of 1% in the explanation of the variance in vigor at work (ΔR2 = 0.01). Differences were found in the positive relationship between levels of social support and vigor at work, among the face-to-face and telework modalities (hybrid and telework), but not between teleworking modalities. As a result, we posit that the different forms of telework moderate (buffer) the relationship experienced between labor resources (social support) and personal resources (vigor at work). This implies that, for the design of teleworking conditions, it is necessary to provide work resources similar to those in face-to-face settings, such as social support.

scholarly journals Body Mass Index Moderates Brain Dynamics and Executive Function: A Structural Equation Modeling Approach

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Lauren Kupis ◽  
Zachary T. Goodman ◽  
Salome Kornfeld ◽  
Celia Romero ◽  
Bryce Dirks ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Executive Function ◽  
Body Mass ◽  
Structural Equation ◽  
Model Fit ◽  
Equation Modeling ◽  
Brain Dynamics ◽  
Latent Factors ◽  
The Impact ◽  
The Relationship

Obesity is associated with negative physical and mental health outcomes. Being overweight/obese is also associated with executive functioning impairments and structural changes in the brain. However, the impact of body mass index (BMI) on the relationship between brain dynamics and executive function (EF) is unknown. The goal of the study was to assess the modulatory effects of BMI on brain dynamics and EF. A large sample of publicly available neuroimaging and neuropsychological assessment data collected from 253 adults (18–45 years; mean BMI 26.95 kg/m2 ± 5.90 SD) from the Nathan Kline Institute (NKI) were included (http://fcon_1000.projects.nitrc.org/indi/enhanced/). Participants underwent resting-state functional MRI and completed the Delis-Kaplan Executive Function System (D-KEFS) test battery (1). Time series were extracted from 400 brain nodes and used in a co-activation pattern (CAP) analysis. Dynamic CAP metrics including dwell time (DT), frequency of occurrence, and transitions were computed. Multiple measurement models were compared based on model fit with indicators from the D-KEFS assigned a priori (shifting, inhibition, and fluency). Multiple structural equation models were computed with interactions between BMI and the dynamic CAP metrics predicting the three latent factors of shifting, inhibition, and fluency while controlling for age, sex, and head motion. Models were assessed for the main effects of BMI and CAP metrics predicting the latent factors. A three-factor model (shifting, inhibition, and fluency) resulted in the best model fit. Significant interactions were present between BMI and CAP 2 (lateral frontoparietal (L-FPN), medial frontoparietal (M-FPN), and limbic nodes) and CAP 5 (dorsal frontoparietal (D-FPN), midcingulo-insular (M-CIN), somatosensory motor, and visual network nodes) DTs associated with shifting. A higher BMI was associated with a positive relationship between CAP DTs and shifting. Conversely, in average and low BMI participants, a negative relationship was seen between CAP DTs and shifting. Our findings indicate that BMI moderates the relationship between brain dynamics of networks important for cognitive control and shifting, an index of cognitive flexibility. Furthermore, higher BMI is linked with altered brain dynamic patterns associated with shifting.

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