2,160 research outputs found
The known unknowns of governance
Empirical researchers interested in how governance shapes various aspects of economic development frequently use the Worldwide Governance indicators (WGI). These variables come in the form of an estimate along with a standard error reflecting the uncertainty of this estimate. Existing empirical work simply uses the estimates as an explanatory variable and discards the information provided by the standard errors. In this paper, we argue that the appropriate practice should be to take into account the uncertainty around the WGI estimates through the use of multiple imputation. We investigate the importance of our proposed approach by revisiting in three applications the results of recently published studies. These applications cover the impact of governance on (i) capital flows; (ii) international trade; (iii) income levels around the world. We generally find that the estimated effects of governance are highly sensitive to the use of multiple imputation. We also show that model misspecification is a concern for the results of our reference studies. We conclude that the effects of governance are hard to establish once we take into account uncertainty around both the WGI estimates and the correct model specification
The Impact of Competition Policy: What are the Known Unknowns?
Evaluations of competition policy are increasingly common and typically establish that consumer bene.ts from detected cases easily outweigh the costs of competition authorities (CA). However, such assessments are often driven by data availability and only capture a small part of the total impact because they sidestep the difficult issue of how to evaluate deterrence. Similarly, they ignore the fact that policy does not root out all anti-competitive cases. This paper suggests a broader framework for evaluation which encompasses these unobserved impacts. Calibration is difficult precisely because we cannot rely on empirical observations on cases which have been observed to make deductions about cases which have not (because they are deterred or undetected). It thereby confronts the classic sample selection problem which is endemic in all studies based on data from CA decisions. Drawing on insights from economic theory, it argues that selection bias is likely to be substantial because the unobserved cases could well be those which are most harmful. If so, the deterrence of anti-competitive mergers may have a much greater positive impact, but the effects of non-detected cartels may be more serious than is usually supposed
The known unknowns of hydraulic engineering
Hydraulic engineers and researchers deal with scientific challenges involving turbulent flow motion and its interactions with the surroundings. Turbulent flows are characterised by unpredictable behaviour, and little systematic research has yet been conducted in natural systems. This paper discusses the implications of recent developments in affordable instrumentation previously characterised by intrinsic weaknesses that adversely affect the quality of the signal outputs. A challenging application is the unsteady turbulence field in tidal bores. The interactions between open channel flows and movable boundaries and atmosphere illustrate another aspect of our limited knowledge. Rapid siltation of reservoirs and air entrainment in turbulent free-surface flows are discussed. In both applications, hydraulic engineers require some broad-based expertise. In turn the education of future hydraulic engineers is of vital importance
The known unknowns of the Hsp90 chaperone
Molecular chaperones are vital proteins that maintain protein homeostasis by
assisting in protein folding, activation, degradation, and stress protection.
Among them, heat-shock protein 90 (Hsp90) stands out as an essential
proteostasis hub in eukaryotes, chaperoning hundreds of "clients" (substrates).
After decades of research, several "known unknowns" about the molecular
function of Hsp90 remain unanswered, hampering rational drug design for the
treatment of cancers, neurodegenerative and other diseases. We highlight three
fundamental open questions, reviewing the current state of the field for each,
and discuss new opportunities, including single-molecule technologies, to
answer the known unknowns of the Hsp90 chaperone.Comment: 29 pages, 4 figure
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The known unknowns of equine mammary neoplasia
Primary equine mammary tumours are rare entities that are considered to have a poor prognosis (Shank, 2009). In the case report associated with this clinical commentary, the authors describe the clinical presentation, management, and histopathological assessment of a comedocarcinoma arising in the mammary gland of a 20 year-old Arabian mare (Sabiza et al., In press). In their article, the authors allude to some of the challenges of diagnosis and prognostication in cases of equine mammary neoplasia. In spite of a number of detailed descriptions of individual cases or case series of equine mammary tumours, there are numerous unanswered questions regarding carcinomas arising in the equine mammary gland, and the concept of ‘known unknowns’ springs to mind. This clinical commentary will consider a selection of interesting and challenging ‘known unknowns’ relating to the pathogenesis, diagnosis, and prognosis of equine mammary tumours.The Pathological Society of Great Britain and Ireland (ICA 1019 02
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Nutrition epidemiology of flavan-3-ols: the known unknowns
Nutritional epidemiology has an important role, as it can provide long-term data from large populations and does not rely on surrogate markers for morbidity/mortality. Meaningful interpretation and applications of outcomes from epidemiological studies depend on the accurate assessment of dietary intake, which is currently mainly based on a combination of self-reporting and food composition data. Flavan-3-ols are a group of bioactives (non-essential dietary components with significant impact on health) that is a possible candidate for the development of dietary recommendations. The breadth of data available on their effect on health also provides the basis for investigating the suitability of the methods currently used in nutritional epidemiology to assess the health effects of bioactives. The outcomes of this assessment demonstrate that the limitations of currently used methods make it virtually impossible to estimate intake accurately from self-reported dietary data. This is due to the limitations of self-reporting, especially from food-frequency questionnaires, and the inability of currently used methods to deal with the high variability of food composition. Indeed, the estimated intake of flavan-3-ols, can only be interpreted as a marker of specific dietary patterns, but not as the actual intake amount. The interpretation of results from such studies are fraught with serious limitations, especially for establishing associations between intake and health and the development of dietary recommendations. Alternative assessment not affected by these limitations, such as biomarkers, are required to overcome these limitations. The development of nutritional biomarkers is therefore crucial to investigate the health effect of bioactives
The known unknowns of anomalous trichromacy
Anomalous trichromacy is the most common minority color vision phenotype, yet the category label obscures a large range of individual differences both in the underlying genetics and in color perception. This review explores both, particularly considering possible reasons for the smaller than expected observed relationship between the spectral sensitivities of anomalous cones and color discrimination. Also considered is the putative process of postreceptoral compensation, where anomalous trichromats may amplify the reduced color signals they receive from their cones to relatively normalize their color vision postreceptorally
The Known Unknowns of Diversity & Inclusion: Supporting Individuals with Hidden & Transitioning Identities
The goal of this workshop is to create a safe and open space for people to learn about individuals with hidden and transitioning identities and ways to support them as community members and allies
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Lock and Dam #1, Asian carp barrier alternatives analysis; the known unknowns
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