4,255 research outputs found
The ontology of causal process theories
There is a widespread belief that the so-called process theories of causation developed by Wesley Salmon and Phil Dowe have given us an original account of what causation really is. In this paper, I show that this is a misconception. The notion of "causal process" does not offer us a new ontological account of causation. I make this argument by explicating the implicit ontological commitments in Salmon and Dowe's theories. From this, it is clear that Salmon's Mark Transmission Theory collapses to a counterfactual theory of causation, while the Conserved Quantity Theory collapses to David Fair's phsyicalist reduction of causation
Surface compositional mapping by spectral ratioing of ERTS-1 MSS data in the Wind River Basin and Range, Wyoming
The author has identified the following significant results. ERTS data collected in August and October 1972 were processed on digital and special purpose analog recognition computers using ratio enhancement and pattern recognition. Ratios of band-averaged laboratory reflectances of some minerals and rock types known to be in the scene compared favorably with ratios derived from the data by ratio normalization procedures. A single ratio display and density slice of the visible channels of ERTS MSS data, Channel 5/Channel 4 (R5,4), separated the Triassic Chugwater formation (redbeds) from other formations present and may have enhanced iron oxide minerals present at the surface in abundance. Comparison of data sets collected over the same area at two different times of the year by digital processing indicated that spectral variation due to environmental factors was reduced by ratio processing
The PLATO End-to-End CCD Simulator -- Modelling space-based ultra-high precision CCD photometry for the assessment study of the PLATO Mission
The PLATO satellite mission project is a next generation ESA Cosmic Vision
satellite project dedicated to the detection of exo-planets and to
asteroseismology of their host-stars using ultra-high precision photometry. The
main goal of the PLATO mission is to provide a full statistical analysis of
exo-planetary systems around stars that are bright and close enough for
detailed follow-up studies. Many aspects concerning the design trade-off of a
space-based instrument and its performance can best be tackled through
realistic simulations of the expected observations. The complex interplay of
various noise sources in the course of the observations made such simulations
an indispensable part of the assessment study of the PLATO Payload Consortium.
We created an end-to-end CCD simulation software-tool, dubbed PLATOSim, which
simulates photometric time-series of CCD images by including realistic models
of the CCD and its electronics, the telescope optics, the stellar field, the
pointing uncertainty of the satellite (or Attitude Control System [ACS]
jitter), and all important natural noise sources. The main questions that were
addressed with this simulator were the noise properties of different
photometric algorithms, the selection of the optical design, the allowable
jitter amplitude, and the expected noise budget of light-curves as a function
of the stellar magnitude for different parameter conditions. The results of our
simulations showed that the proposed multi-telescope concept of PLATO can
fulfil the defined scientific goal of measuring more than 20000 cool dwarfs
brighter than mV =11 with a precision better than 27 ppm/h which is essential
for the study of earth-like exo-planetary systems using the transit method.Comment: 5 pages, submitted for the Proceedings of the 4th HELAS International
Conference: Seismological Challenges for Stellar Structur
Theurapeutic Effectiveness of Rat Bone Marrow Stem Cells in Poly Cystic Ovary Syndrome Mice Model on Folliculogenesis, TGF-β, GDF-9 Expression, and Estrogen, TNF- and Androgen Levels
Objectives: to identify therapeutic effectiveness of Rat Bone Marrow stem cell in PCOS rats model on folliculogenesis, TGF-beta and GDF-9 expression and on estrogen, TNF-a and androgen levels.Material and Methods: this study is a laboratory experimental research with using animal testing. PCOS was induced by the administration of testosterone propionate hormone into 30 mice. The subjects of this study are divided into 2 groups: stem cell group and control group. The mice were injected with testosterone then vaginal swab was performed to determine the mice cycle. After determining mice in anestrous cycle, stem cell was injected. TNF-a was measured with immunohistochemistry and androgen was examined using ELISA. The data was measured by student t-test.Result: The average number of TNF-a expression in control group was lower than stem cell group (5.35 vs 2.34; p= 0.0026). The average androgen level for stem cell group was lower than mean for control group (2.31 vs 0.40; p= 0.0026).Conclusion: In this study of polycystic model mice, stem cell decreased the expression of TNF-a and androgen leve
Model-based Cognitive Neuroscience: Multifield Mechanistic Integration in Practice
Autonomist accounts of cognitive science suggest that cognitive model building and theory construction (can or should) proceed independently of findings in neuroscience. Common functionalist justifications of autonomy rely on there being relatively few constraints between neural structure and cognitive function (e.g., Weiskopf, 2011). In contrast, an integrative mechanistic perspective stresses the mutual constraining of structure and function (e.g., Piccinini & Craver, 2011; Povich, 2015). In this paper, I show how model-based cognitive neuroscience (MBCN) epitomizes the integrative mechanistic perspective and concentrates the most revolutionary elements of the cognitive neuroscience revolution (Boone & Piccinini, 2016). I also show how the prominent subset account of functional realization supports the integrative mechanistic perspective I take on MBCN and use it to clarify the intralevel and interlevel components of integration
Visualizing elements of Sha[3] in genus 2 jacobians
Mazur proved that any element xi of order three in the Shafarevich-Tate group
of an elliptic curve E over a number field k can be made visible in an abelian
surface A in the sense that xi lies in the kernel of the natural homomorphism
between the cohomology groups H^1(k,E) -> H^1(k,A). However, the abelian
surface in Mazur's construction is almost never a jacobian of a genus 2 curve.
In this paper we show that any element of order three in the Shafarevich-Tate
group of an elliptic curve over a number field can be visualized in the
jacobians of a genus 2 curve. Moreover, we describe how to get explicit models
of the genus 2 curves involved.Comment: 12 page
Final report of the Committee on Depreciation; Dissenting opinion to the final report of the Committee on Depreciation
Losses of value which are complete, and fully demonstrated by proper abandonment or necessary replacement of the whole or a unit part of a property, are a matter of history and fact, and require only proper accounting to determine their occurrence and amount. Losses of value, which are partial or incomplete, always require prophecy as to future need, usefulness, and service, in order to properly divide that portion of the value which still exists from that which is lost. This function necessitates much more judgment than accounting. It requires the careful analysis of a broadly trained, experienced, and practical mind, thoroughly familiar with the business in question. Original item in Boxno. 0409
Airborne Particles in Museums
Presents one in a series of research activities aimed at a better understanding of the origin and fate of air pollution within the built environment
Do neuropsychological tests detect preclinical Alzheimer's disease: Individual-test versus cognitive-discrepancy score analyses.
Attempts to identify cognitive markers of a preclinical phase of Alzheimer’s disease (AD) have yielded inconsistent findings. The problem may stem in part from methodologies that are insensitive to potential subgroups within the at-risk, preclinical AD population (PCAD). The present study investigated the utility of asymmetric cognitive profiles in identifying individ-uals at risk for AD. Twenty elderly adults who were later diagnosed with AD (PCAD) and 20 matched control participants were compared on measures of cognitive asymmetry derived from difference scores on tests of verbal and visuospatial ability. Although both groups performed similarly on the individual tests, comparisons using difference scores revealed significantly larger discrepancies between naming and visuoconstruction skills in the PCAD group. The PCAD group also had a higher frequency of asymmetric cognitive profiles relative to a normative group. Subtle cognitive changes can precede the onset of Alz-heimer’s disease (AD) by as many as 7 to 10 years (Elias et al., 2000; Linn, Wolf, Bachman, & Knoefel, 1995). Find-ings of a long prodromal period have fostered new researc
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Motile Artificial Chromatophores: Light-Triggered Nanoparticles for Microdroplet Locomotion and Color Change
Gold nanoparticles coated with a poly(N-isopropylacrylamide) (pNIPAM) shell undergo reversible dis/assembly below and above the critical temperature of 32°C. Loading these particles into microdroplets at high density creates light-driven artificial chromatophores. Triggering the nanoparticle assembly gives dramatic color changes from nanoparticle localization at the base of the droplets, resembling zebrafish melanophores. These reversible chromatophore states can be switched by both bulk and optical heating, explored here in individual microdroplets and in large cm^2 areas of close-packed droplets. Illuminating chromatophores off-center with a tightly focused beam results in droplet locomotion via two separate mechanisms, Marangoni interfacial shear and gas bubble propulsion, depending on optical power.ER
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