216 research outputs found
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The (ir)relevance of truth to rationality
It is possible to act for a reason. We do it all the time. You might have brought her medicine for the reason that she is ill. He might go to the store to get milk. Edmund might skate in the middle of the pond because the ice in the middle of the pond is thin. What must be true of us, and of the world, such that we can act for reasons?
In normal cases, when someone acts for the reason that (for example) the ice in the middle of the pond is thin, it really is the case that the ice in the middle is thin. This is mostly due to the fact that we are not often wrong about such mundane ways the world is. But what if one takes it that the ice is thin, and in fact it is not thin? Can one still act for the reason that the ice is thin?
In my efforts to give a sufficient answer to this question, I have been led to a package of views, the core tenets of which are at least the following five. First, it is possible to act in the light of a falsehood: a consideration that is not the case can be an agentâs reason for acting. Second, it is not possible to act in unbelief: in order for an agent to act for a reason, the agent must at least believe that reason to be the case. Third, the reasons for which agents act can play a role in explaining the actions done for those reasons ââ even when agents act in the light of falsehoods. Fourth, there are very few (if any) formal rules or principles constraining the explanatory role of reasons. Any action explanation that specifies the content of the reason for acting has reserved a legitimate explanatory role for the reason. Fifth, all of these claims apply equally to motivating and normative reasons, so-called practical and epistemic reasons, and reasons for action and reasons for belief.Philosoph
Methods and instruments for materials testing
Methods and instruments for characterizing a material, such as the properties of bone in a living human subject, using a test probe constructed for insertion into the material and a reference probe aligned with the test probe in a housing. The housing is hand held or placed so that the reference probe contacts the surface of the material under pressure applied either by hand or by the weight of the housing. The test probe is inserted into the material to indent the material while maintaining the reference probe substantially under the hand pressure or weight of the housing allowing evaluation of a property of the material related to indentation of the material by the probe. Force can be generated by a voice coil in a magnet structure to the end of which the test probe is connected and supported in the magnet structure by a flexure, opposing flexures, a linear translation stage, or a linear bearing. Optionally, a measurement unit containing the test probe and reference probe is connected to a base unit with a wireless connection, allowing in the field material testing
Understanding and Gathering Decision-Making Challenges in EU Agri-Food Systems with Uncertain Regulations. A MCDM-AHP analysis
The development of the Agri-Food sector in both the UK and EU is a government priority, especially in building more resilient and sustainable Agri-Food Supply Chains, which are also subject to a variety of local and global regulations, determined the Common Agricultural Policy or the World Trade Organisation. Understanding Agri-Food Supply Chains requires a detailed understanding of upstream and downstream relationships amongst suppliers and customers. However, considering the current regulation changes in EU, UK/EU Agri-Food decision-makers, are facing several market challenges, especially in adapting to the externalities they cannot control (technological innovation, new nutritional market demands, economy, political markets, food security and climate change). Based on the N8 SIMULAGRIT project, this research aims at identifying factors, both opportunities, and constraints, that currently influence Agri-Food Supply Chains performance once uncertainties in regulations are identified. Thus, and based on case studies from the UK, Spain, Italy, âand Chile, a compressive AHP study of alternatives Agri-Food strategies to deal with such uncertainties has been carried out. From this, it is depicted that key criteria are in the context of Finance, Supply Chain and Logistics, Human Resources and National/International trade. Thus, the research work has helped to identify and evaluate a set of strategies which may be used to support further policy-making processes and scenarios
Extensibility of Human Asteroid Mission to Mars and Other Destinations
This paper will describe the benefits of execution of the Asteroid Redirect Mission as an early mission in deep space, demonstrating solar electric propulsion, deep space robotics, ground and on-board navigation, docking, and EVA. The paper will also discuss how staging in trans-lunar space and the elements associated with this mission are excellent building blocks for subsequent deep space missions to Mars or other destinations
Transiting Exoplanet Studies and Community Targets for JWST's Early Release Science Program
The James Webb Space Telescope will revolutionize transiting exoplanet
atmospheric science due to its capability for continuous, long-duration
observations and its larger collecting area, spectral coverage, and spectral
resolution compared to existing space-based facilities. However, it is unclear
precisely how well JWST will perform and which of its myriad instruments and
observing modes will be best suited for transiting exoplanet studies. In this
article, we describe a prefatory JWST Early Release Science (ERS) program that
focuses on testing specific observing modes to quickly give the community the
data and experience it needs to plan more efficient and successful future
transiting exoplanet characterization programs. We propose a multi-pronged
approach wherein one aspect of the program focuses on observing transits of a
single target with all of the recommended observing modes to identify and
understand potential systematics, compare transmission spectra at overlapping
and neighboring wavelength regions, confirm throughputs, and determine overall
performances. In our search for transiting exoplanets that are well suited to
achieving these goals, we identify 12 objects (dubbed "community targets") that
meet our defined criteria. Currently, the most favorable target is WASP-62b
because of its large predicted signal size, relatively bright host star, and
location in JWST's continuous viewing zone. Since most of the community targets
do not have well-characterized atmospheres, we recommend initiating preparatory
observing programs to determine the presence of obscuring clouds/hazes within
their atmospheres. Measurable spectroscopic features are needed to establish
the optimal resolution and wavelength regions for exoplanet characterization.
Other initiatives from our proposed ERS program include testing the instrument
brightness limits and performing phase-curve observations.(Abridged)Comment: This is a white paper that originated from an open discussion at the
Enabling Transiting Exoplanet Science with JWST workshop held November 16 -
18, 2015 at STScI (http://www.stsci.edu/jwst/science/exoplanets). Accepted
for publication in PAS
Coordinating Tissue Regeneration Through Transforming Growth Factorâ Ă² Activated Kinase 1 Inactivation and Reactivation
Aberrant wound healing presents as inappropriate or insufficient tissue formation. Using a model of musculoskeletal injury, we demonstrate that loss of transforming growth factorâ Ă² activated kinase 1 (TAK1) signaling reduces inappropriate tissue formation (heterotopic ossification) through reduced cellular differentiation. Upon identifying increased proliferation with loss of TAK1 signaling, we considered a regenerative approach to address insufficient tissue production through coordinated inactivation of TAK1 to promote cellular proliferation, followed by reactivation to elicit differentiation and extracellular matrix production. Although the current regenerative medicine paradigm is centered on the effects of drug treatment (â drug onâ ), the impact of drug withdrawal (â drug offâ ) implicit in these regimens is unknown. Because current TAK1 inhibitors are unable to phenocopy genetic Tak1 loss, we introduce the dualâ inducible COmbinational Sequential Inversion ENgineering (COSIEN) mouse model. The COSIEN mouse model, which allows us to study the response to targeted drug treatment (â drug onâ ) and subsequent withdrawal (â drug offâ ) through genetic modification, was used here to inactivate and reactivate Tak1 with the purpose of augmenting tissue regeneration in a calvarial defect model. Our study reveals the importance of both the â drug onâ (Creâ mediated inactivation) and â drug offâ (Flpâ mediated reactivation) states during regenerative therapy using a mouse model with broad utility to study targeted therapies for disease. Stem Cells 2019;37:766â 778Manipulating transforming growth factor Ă²â activated kinase 1 for cell and scaffold free tissue regeneration using a dualâ inducible Combinational Sequential Inversion Engineering mouse model.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149573/1/stem2991_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149573/2/stem2991.pd
Exploring inequities in child welfare and child protection services: explaining the 'inverse intervention law'
Attempts to record, understand and respond to variations in child welfare and protection reporting, service patterns and outcomes are international, numerous and longstanding. Reframing such variations as an issue of inequity between children and between families opens the way to a new approach to explaining the profound difference in intervention rates between and within countries and administrative districts. Recent accounts of variation have frequently been based on the idea that there is a binary division between bias and risk (or need). Here we propose seeing supply (bias) and demand (risk) factors as two aspects of a single system, both framed, in part, by social structures. A recent finding from a study of intervention rates in England, the 'inverse intervention law', is used to illustrate the complex ways in which a range of factors interact to produce intervention rates. In turn, this analysis raises profound moral, policy, practice and research questions about current child welfare and child protection services
Hubble Space Telescope hot Jupiter transmission spectral survey: a detection of Na and strong optical absorption in HAT-P-1b
We present an optical to near-infrared transmission spectrum of the hot Jupiter HAT-P-1b, based on Hubble Space Telescope observations, covering the spectral regime from 0.29 to 1.027âÎźm with Space Telescope Imaging Spectrograph (STIS), which is coupled with a recent Wide Field Camera 3 (WFC3) transit (1.087 to 1.687âÎźm). We derive refined physical parameters of the HAT-P-1 system, including an improved orbital ephemeris. The transmission spectrum shows a strong absorption signature shortward of 0.55âÎźm, with a strong blueward slope into the near-ultraviolet. We detect atmospheric sodium absorption at a 3.3Ď significance level, but find no evidence for the potassium feature. The red data imply a marginally flat spectrum with a tentative absorption enhancement at wavelength longer than âź 0.85âÎźm. The STIS and WFC3 spectra differ significantly in absolute radius level (4.3 Âą 1.6 pressure scaleheights), implying strong optical absorption in the atmosphere of HAT-P-1b. The optical to near-infrared difference cannot be explained by stellar activity, as simultaneous stellar activity monitoring of the G0V HAT-P-1b host star and its identical companion show no significant activity that could explain the result. We compare the complete STIS and WFC3 transmission spectrum with theoretical atmospheric models which include haze, sodium and an extra optical absorber. We find that both an optical absorber and a supersolar sodium to water abundance ratio might be a scenario explaining the HAT-P-1b observations. Our results suggest that strong optical absorbers may be a dominant atmospheric feature in some hot Jupiter exoplanets
Genome-Wide Association Study of Non-Alcoholic Fatty Liver Disease using Electronic Health Records
Genomeâwide association studies (GWAS) have identified several risk loci for nonalcoholic fatty liver disease (NAFLD). Previous studies have largely relied on small sample sizes and have assessed quantitative traits. We performed a caseâcontrol GWAS in the UK Biobank using recorded diagnosis of NAFLD based on diagnostic codes recommended in recent consensus guidelines. We performed a GWAS of 4,761 cases of NAFLD and 373,227 healthy controls without evidence of NAFLD. Sensitivity analyses were performed excluding other coâexisting hepatic pathology, adjusting for body mass index (BMI) and adjusting for alcohol intake. A total of 9,723,654 variants were assessed by logistic regression adjusted for age, sex, genetic principal components, and genotyping batch. We performed a GWAS metaâanalysis using available summary association statistics. Six risk loci were identified (PÂ <Â 5*10(â8)) (apolipoprotein E [APOE], patatinâlike phospholipase domain containing 3 [PNPLA3, transmembrane 6 superfamily member 2 [TM6SF2], glucokinase regulator [GCKR], mitochondrial amidoxime reducing component 1 [MARC1], and tribbles pseudokinase 1 [TRIB1]). All loci retained significance in sensitivity analyses without coâexistent hepatic pathology and after adjustment for BMI. PNPLA3 and TM6SF2 remained significant after adjustment for alcohol (alcohol intake was known in only 158,388 individuals), with others demonstrating consistent direction and magnitude of effect. All six loci were significant on metaâanalysis. Rs429358 (PÂ =Â 2.17*10(â11)) is a missense variant within the APOE gene determining Ďľ4 versus Ďľ2/Ďľ3 alleles. The Ďľ4 allele of APOE offered protection against NAFLD (odds ratio for heterozygotes 0.84 [95% confidence interval 0.78â0.90] and homozygotes 0.64 [0.50â0.79]). Conclusion: This GWAS replicates six known NAFLDâsusceptibility loci and confirms that the Ďľ4 allele of APOE is associated with protection against NAFLD. The results are consistent with published GWAS using histological and radiological measures of NAFLD, confirming that NAFLD identified through diagnostic codes from consensus guidelines is a valid alternative to more invasive and costly approaches
The Need for Laboratory Measurements and Ab Initio Studies to Aid Understanding of Exoplanetary Atmospheres
We are now on a clear trajectory for improvements in exoplanet observations
that will revolutionize our ability to characterize their atmospheric
structure, composition, and circulation, from gas giants to rocky planets.
However, exoplanet atmospheric models capable of interpreting the upcoming
observations are often limited by insufficiencies in the laboratory and
theoretical data that serve as critical inputs to atmospheric physical and
chemical tools. Here we provide an up-to-date and condensed description of
areas where laboratory and/or ab initio investigations could fill critical gaps
in our ability to model exoplanet atmospheric opacities, clouds, and chemistry,
building off a larger 2016 white paper, and endorsed by the NAS Exoplanet
Science Strategy report. Now is the ideal time for progress in these areas, but
this progress requires better access to, understanding of, and training in the
production of spectroscopic data as well as a better insight into chemical
reaction kinetics both thermal and radiation-induced at a broad range of
temperatures. Given that most published efforts have emphasized relatively
Earth-like conditions, we can expect significant and enlightening discoveries
as emphasis moves to the exotic atmospheres of exoplanets.Comment: Submitted as an Astro2020 Science White Pape
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