581 research outputs found
Using Relational Frame Theory to Teach Nutritional Values
Obesity is a significant health concern people of all ages on a global level. There have many studies that addressed nutrition concepts, however, those results are inadequate to lead to long term improved health because the improvements were too weak, too short lived, or did not generalize to other environments. There is a need to enhance the educational component and one solution is to design the instructional component using a theory of language and cognition, Relational Frame Theory (RFT). This method not only has potential to help the student learn information about foods, but also learn how to make comparisons between foods. This study implemented a nutritional education program using a relational frame theory format to teach nutritional relations using the relational frame, âhealthier,â and assessed for derived relations. The first step involved teaching equivalence relations between nine foods categorized into three groups, maximum nutritional value, moderate nutritional value, and minimal nutritional value. After the initial equivalence training and remediation procedures all the participants demonstrated mastery on equivalence relations that were taught and derived. Next, participants were taught two comparison relations and assessed for comparison relations that were taught and derived. Of the comparison relations assessed, two of the participants improved their performance in the comparison relations that were taught
Frequency-Dependent Squeezing for Advanced LIGO
The first detection of gravitational waves by the Laser Interferometer
Gravitational-wave Observatory (LIGO) in 2015 launched the era of gravitational
wave astronomy. The quest for gravitational wave signals from objects that are
fainter or farther away impels technological advances to realize ever more
sensitive detectors. Since 2019, one advanced technique, the injection of
squeezed states of light is being used to improve the shot noise limit to the
sensitivity of the Advanced LIGO detectors, at frequencies above Hz.
Below this frequency, quantum back action, in the form of radiation pressure
induced motion of the mirrors, degrades the sensitivity. To simultaneously
reduce shot noise at high frequencies and quantum radiation pressure noise at
low frequencies requires a quantum noise filter cavity with low optical losses
to rotate the squeezed quadrature as a function of frequency. We report on the
observation of frequency-dependent squeezed quadrature rotation with rotation
frequency of 30Hz, using a 16m long filter cavity. A novel control scheme is
developed for this frequency-dependent squeezed vacuum source, and the results
presented here demonstrate that a low-loss filter cavity can achieve the
squeezed quadrature rotation necessary for the next planned upgrade to Advanced
LIGO, known as "A+."Comment: 6 pages, 2 figures, to be published in Phys. Rev. Let
Interferometric Constraints on Quantum Geometrical Shear Noise Correlations
Final measurements and analysis are reported from the first-generation
Holometer, the first instrument capable of measuring correlated variations in
space-time position at strain noise power spectral densities smaller than a
Planck time. The apparatus consists of two co-located, but independent and
isolated, 40 m power-recycled Michelson interferometers, whose outputs are
cross-correlated to 25 MHz. The data are sensitive to correlations of
differential position across the apparatus over a broad band of frequencies up
to and exceeding the inverse light crossing time, 7.6 MHz. By measuring with
Planck precision the correlation of position variations at spacelike
separations, the Holometer searches for faint, irreducible correlated position
noise backgrounds predicted by some models of quantum space-time geometry. The
first-generation optical layout is sensitive to quantum geometrical noise
correlations with shear symmetry---those that can be interpreted as a
fundamental noncommutativity of space-time position in orthogonal directions.
General experimental constraints are placed on parameters of a set of models of
spatial shear noise correlations, with a sensitivity that exceeds the
Planck-scale holographic information bound on position states by a large
factor. This result significantly extends the upper limits placed on models of
directional noncommutativity by currently operating gravitational wave
observatories.Comment: Matches the journal accepted versio
LIGOâs quantum response to squeezed states
Gravitational wave interferometers achieve their profound sensitivity by combining a Michelson interferometer with optical cavities, suspended masses, and now, squeezed quantum states of light. These states modify the measurement process of the LIGO, VIRGO and GEO600 interferometers to reduce the quantum noise that masks astrophysical signals; thus, improvements to squeezing are essential to further expand our gravitational view of the Universe. Further reducing quantum noise will require both lowering decoherence from losses as well more sophisticated manipulations to counter the quantum back-action from radiation pressure. Both tasks require fully understanding the physical interactions between squeezed light and the many components of km-scale interferometers. To this end, data from both LIGO observatories in observing run three are expressed using frequency-dependent metrics to analyze each detectorâs quantum response to squeezed states. The response metrics are derived and used to concisely describe physical mechanisms behind squeezingâs simultaneous interaction with transverse-mode selective optical cavities and the quantum radiation pressure noise of suspended mirrors. These metrics and related analysis are broadly applicable for cavity-enhanced optomechanics experiments that incorporate external squeezing, andâfor the first timeâgive physical descriptions of every feature so far observed in the quantum noise of the LIGO detectors
Obesity Contributes to an Attenuated Spontaneous Baroreflex Sensitivity in UCD-Type 2 Diabetic Rats
Previous studies suggest impaired baroreflex function in individuals with type 2 diabetes (T2D), which is critically important since it leads to an increased risk for adverse cardiovascular events. Currently, the underlying mechanisms remain poorly understood. The baroreflex, essential for maintaining blood pressure homeostasis, can also be influenced by several risk factors, one of which is obesity. Obesity has been shown to markedly decrease baroreflex sensitivity (BRS) in non-diabetic individuals, and given that the majority of T2D patients are obese, it is likely that impairment in baroreflex function in T2D is mainly driven by obesity. PURPOSE: To investigate the effects of obesity on baroreflex function in T2D rats at different phases of the disease. We hypothesized that BRS would be attenuated in T2D rats, and this would be associated with increased adiposity. METHODS: Experiments were performed on male University of California Davis (UCD)-T2D rats assigned to four experimental groups (n=6 in each group): prediabetic (PD), diabetes-onset (DO), 4 weeks after onset [recent-onset (RO)], and 12 weeks after onset [late-onset (LO)]. Age-matched healthy Sprague-Dawley rats were assigned to the same experimental groups as controls (n=6 in each). Rats were anesthetized and blood pressure was directly measured for 5 min. Hemodynamic variables were obtained on a beat-to-beat basis and spontaneous BRS was assessed using the sequence technique. Dual-energy X-ray absorptiometry (DEXA) was used to assess body composition and visceral fat was determined by identifying an abdominal region of interest. Data are presented as mean ± SD. RESULTS: Spontaneous BRS was significantly lower in T2D compared to control rats at DO (3.7 ± 3.2 ms/mmHg vs 16.1 ± 8.4 ms/mmHg; P=0.01). However, this difference was abolished by LO (13.4 ± 8.1 ms/mmHg vs 9.2 ± 6.0 ms/mmHg; P=0.16). T2D rats had the highest level of adiposity during the RO phase but it significantly decreased by LO (PD: 136 ± 14 g; DO: 175 ± 24 g; RO: 207 ± 44 g; LO: 163 ± 45 g; P=0.03). In addition, T2D rats had greater visceral fat compared to control rats regardless of the disease phase (P\u3c0.01). CONCLUSION: These findings suggest that obesity may contribute to an attenuated spontaneous BRS in T2D rats and suggests a link between metabolic and autonomic dysfunction in T2D
Frequency-Dependent Squeezing for Advanced LIGO
The first detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015 launched the era of gravitational-wave astronomy. The quest for gravitational-wave signals from objects that are fainter or farther away impels technological advances to realize ever more sensitive detectors. Since 2019, one advanced technique, the injection of squeezed states of light, is being used to improve the shot-noise limit to the sensitivity of the Advanced LIGO detectors, at frequencies above âŒ50Hz. Below this frequency, quantum backaction, in the form of radiation pressure induced motion of the mirrors, degrades the sensitivity. To simultaneously reduce shot noise at high frequencies and quantum radiation pressure noise at low frequencies requires a quantum noise filter cavity with low optical losses to rotate the squeezed quadrature as a function of frequency. We report on the observation of frequency-dependent squeezed quadrature rotation with rotation frequency of 30 Hz, using a 16-m-long filter cavity. A novel control scheme is developed for this frequency-dependent squeezed vacuum source, and the results presented here demonstrate that a low-loss filter cavity can achieve the squeezed quadrature rotation necessary for the next planned upgrade to Advanced LIGO, known as âA+.
MHz gravitational wave constraints with decameter Michelson interferometers
A new detector, the Fermilab Holometer, consists of separate yet identical 39-meter Michelson interferometers. Strain sensitivity achieved is better than 10[superscript -21]/âHz between 1 to 13 MHz from a 130-h data set. This measurement exceeds the sensitivity and frequency range made from previous high frequency gravitational wave experiments by many orders of magnitude. Constraints are placed on a stochastic background at 382 Hz resolution. The 3Ï upper limit on Ω[subscript GW], the gravitational wave energy density normalized to the closure density, ranges from 5.6Ă10[superscript 12] at 1 MHz to 8.4Ă10[superscript 15] at 13 MHz. Another result from the same data set is a search for nearby primordial black hole binaries (PBHB). There are no detectable monochromatic PBHBs in the mass range 0.83â3.5Ă10[superscript 21]ââg between the Earth and the Moon. Projections for a chirp search with the same data set increase the mass range to 0.59-2.5Ă10[superscript 25]ââg and distances out to Jupiter. This result presents a new method for placing limits on a poorly constrained mass range of primordial black holes. Additionally, solar system searches for PBHBs place limits on their contribution to the total dark matter fraction.United States. Dept. of Energy (Contract DE-AC02-07CH11359)United States. Dept. of Energy (Early Career Research Program FNAL FWP 11-03)Templeton FoundationNational Science Foundation (U.S.) (Grants PHY- 1205254 and DGE-1144082)National Aeronautics and Space Administration (Grant NNX09AR38G)Fermi Research AllianceUniversity of Chicago. Kavli Institute for Cosmological PhysicsUniversity of Chicago. Fermilab Strategic Collaborative InitiativesScience Support ConsortiumNational Science Foundation (U.S.). Graduate Research Fellowship Program (Grant DGE-0638477)Universities Research Association (U.S.). Visiting Scholars Progra
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