1,830 research outputs found
An aesthetic challenge to manipulation : a study on the pragmatics of communication
In this thesis, it is my intent to argue that introducing John Dewey's aesthetic theory into Jürgen Habermas's pragmatics of communication will provide more evidence in opposition to the suggestion that manipulation can avert future legitimation crises. In developing this thesis, several steps will be taken. First, I will explicate Habermas's work on legitimation crises in order to explain what a legitimation crisis is and how such a crisis arises. I will then consider two potential remedies that might help avert a legitimation crisis: increasing material rewards or increasing ideology/manipulation. Next, I will provide some explanations concerning why Habermas's pragmatic theory needs to be reinforced in order to adequately oppose the recommendation to use manipulation to avert legitimation crises. By juxtaposing Dewey's aesthetic theory with Habermas's pragmatics of communication, I intend to align myself with Habermas, and oppose the suggestion that manipulation can permanently avert future legitimation crises. By considering Dewey alongside Habermas, I will problematize manipulation and argue that manipulation is an unstable remedial measure. In conclusion, I will suggest that more stable remedial measures need to be sought if society desires to permanently avert legitimation crise
Laser-induced fluorescence studies of HfF+ produced by autoionization
Autoionization of Rydberg states of HfF, prepared using the optical-optical
double resonance (OODR) technique, holds promise to create HfF+ in a particular
Zeeman level of a rovibronic state for an electron electric dipole moment
(eEDM) search. We characterize a vibronic band of Rydberg HfF at 54 cm-1 above
the lowest ionization threshold and directly probe the state of the ions formed
from this vibronic band by performing laser-induced fluorescence (LIF) on the
ions. The Rydberg HfF molecules show a propensity to decay into only a few ion
rotational states of a given parity and are found to preserve their orientation
qualitatively upon autoionization. We show empirically that we can create 30%
of the total ion yield in a particular |J+,M+> state and present a simplified
model describing autoionization from a given Rydberg state that assumes no
angular dynamics.Comment: 8 pages, 5 figure
Dynamical structure of the inner 100 AU of the deeply embedded protostar IRAS 16293-2422
A fundamental question about the early evolution of low-mass protostars is
when circumstellar disks may form. High angular resolution observations of
molecular transitions in the (sub)millimeter wavelength windows make it
possible to investigate the kinematics of the gas around newly-formed stars,
for example to identify the presence of rotation and infall. IRAS 16293-2422
was observed with the extended Submillimeter Array (eSMA) resulting in
subarcsecond resolution (0.46" x 0.29", i.e. 55 35~AU) images
of compact emission from the CO (3-2) and CS (7-6) transitions at
337~GHz (0.89~mm). To recover the more extended emission we have combined the
eSMA data with SMA observations of the same molecules. The emission of
CO (3-2) and CS (7-6) both show a velocity gradient oriented
along a northeast-southwest direction with respect to the continuum marking the
location of one of the components of the binary, IRAS16293A. Our combined eSMA
and SMA observations show that the velocity field on the 50--400~AU scales is
consistent with a rotating structure. It cannot be explained by simple
Keplerian rotation around a single point mass but rather needs to take into
account the enclosed envelope mass at the radii where the observed lines are
excited. We suggest that IRAS 16293-2422 could be among the best candidates to
observe a pseudo-disk with future high angular resolution observations.Comment: Accepted for publication in ApJ, 18 pages, 10 figure
Fabrication of low-cost, large-area prototype Si(Li) detectors for the GAPS experiment
A Si(Li) detector fabrication procedure has been developed with the aim of
satisfying the unique requirements of the GAPS (General Antiparticle
Spectrometer) experiment. Si(Li) detectors are particularly well-suited to the
GAPS detection scheme, in which several planes of detectors act as the target
to slow and capture an incoming antiparticle into an exotic atom, as well as
the spectrometer and tracker to measure the resulting decay X-rays and
annihilation products. These detectors must provide the absorption depth,
energy resolution, tracking efficiency, and active area necessary for this
technique, all within the significant temperature, power, and cost constraints
of an Antarctic long-duration balloon flight. We report here on the fabrication
and performance of prototype 2"-diameter, 1-1.25 mm-thick, single-strip Si(Li)
detectors that provide the necessary X-ray energy resolution of 4 keV for
a cost per unit area that is far below that of previously-acquired commercial
detectors. This fabrication procedure is currently being optimized for the
4"-diameter, 2.5 mm-thick, multi-strip geometry that will be used for the GAPS
flight detectors.Comment: Accepted for publication at Nuclear Instrumentation and Methods A, 12
pages, 11 figure
REMPI Spectroscopy of HfF
The spectrum of electronic states at 30000--33000 cm in hafnium
fluoride has been studied using (1+1) resonance-enhanced multi-photon
ionization (REMPI) and (1+1) REMPI. Six and ten
vibronic bands have been characterized. We report the molecular constants for
these bands and estimate the electronic energies of the excited states using a
correction derived from the observed isotope shifts. When either of two closely
spaced electronic states is used as an intermediate state to access
autoionizing Rydberg levels, qualitatively distinct autoionization spectra are
observed. The intermediate state-specificity of the autoionization spectra
bodes well for the possibility of using a selected state as an
intermediate state to create ionic HfF in various selected quantum states,
an important requirement for our electron electric dipole moment (eEDM) search
in HfF.Comment: 11 pages, 8 figures, 1 tabl
Measuring the spatial extent of texture pooling using reverse correlation
The local image representation produced by early stages of visual analysis is uninformative regarding spatially extensive textures and surfaces. We know little about the cortical algorithm used to combine local information over space, and still less about the area over which it can operate. But such operations are vital to support perception of real-world objects and scenes. Here, we deploy a novel reverse-correlation technique to measure the extent of spatial pooling for target regions of different areas placed either in the central visual field, or more peripherally. Stimuli were large arrays of micropatterns, with their contrasts perturbed individually on an interval-by-interval basis. By comparing trial-by-trial observer responses with the predictions of computational models, we show that substantial regions (up to 13 carrier cycles) of a stimulus can be monitored in parallel by summing contrast over area. This summing strategy is very different from the more widely assumed signal selection strategy (a MAX operation), and suggests that neural mechanisms representing extensive visual textures can be recruited by attention. We also demonstrate that template resolution is much less precise in the parafovea than in the fovea, consistent with recent accounts of crowding
Insulin resistance drives hepatic de novo lipogenesis in nonalcoholic fatty liver disease
BACKGROUNDAn increase in intrahepatic triglyceride (IHTG) is the hallmark feature of nonalcoholic fatty liver disease (NAFLD) and is decreased by weight loss. Hepatic de novo lipogenesis (DNL) contributes to steatosis in individuals with NAFLD. The physiological factors that stimulate hepatic DNL and the effect of weight loss on hepatic DNL are not clear.METHODSHepatic DNL, 24-hour integrated plasma insulin and glucose concentrations, and both liver and whole-body insulin sensitivity were determined in individuals who were lean (n = 14), obese with normal IHTG content (n = 26), or obese with NAFLD (n = 27). Hepatic DNL was assessed using the deuterated water method corrected for the potential confounding contribution of adipose tissue DNL. Liver and whole-body insulin sensitivity was assessed using the hyperinsulinemic-euglycemic clamp procedure in conjunction with glucose tracer infusion. Six subjects in the obese-NAFLD group were also evaluated before and after a diet-induced weight loss of 10%.RESULTSThe contribution of hepatic DNL to IHTG-palmitate was 11%, 19%, and 38% in the lean, obese, and obese-NAFLD groups, respectively. Hepatic DNL was inversely correlated with hepatic and whole-body insulin sensitivity, but directly correlated with 24-hour plasma glucose and insulin concentrations. Weight loss decreased IHTG content, in conjunction with a decrease in hepatic DNL and 24-hour plasma glucose and insulin concentrations.CONCLUSIONSThese data suggest hepatic DNL is an important regulator of IHTG content and that increases in circulating glucose and insulin stimulate hepatic DNL in individuals with NAFLD. Weight loss decreased IHTG content, at least in part, by decreasing hepatic DNL.TRIAL REGISTRATIONClinicalTrials.gov NCT02706262.FUNDINGThis study was supported by NIH grants DK56341 (Nutrition Obesity Research Center), DK20579 (Diabetes Research Center), DK52574 (Digestive Disease Research Center), and RR024992 (Clinical and Translational Science Award), and by grants from the Academy of Nutrition and Dietetics Foundation, the College of Natural Resources of UCB, and the Pershing Square Foundation
Large-area Si(Li) Detectors for X-ray Spectrometry and Particle Tracking for the GAPS Experiment
Large-area lithium-drifted silicon (Si(Li)) detectors, operable 150{\deg}C
above liquid nitrogen temperature, have been developed for the General
Antiparticle Spectrometer (GAPS) balloon mission and will form the first such
system to operate in space. These 10 cm-diameter, 2.5 mm-thick multi-strip
detectors have been verified in the lab to provide <4 keV FWHM energy
resolution for X-rays as well as tracking capability for charged particles,
while operating in conditions (~-40{\deg}C and ~1 Pa) achievable on a
long-duration balloon mission with a large detector payload. These
characteristics enable the GAPS silicon tracker system to identify cosmic
antinuclei via a novel technique based on exotic atom formation, de-excitation,
and annihilation. Production and large-scale calibration of ~1000 detectors has
begun for the first GAPS flight, scheduled for late 2021. The detectors
developed for GAPS may also have other applications, for example in heavy
nuclei identification
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