470 research outputs found
Interference, reduced action, and trajectories
Instead of investigating the interference between two stationary, rectilinear
wave functions in a trajectory representation by examining the two rectilinear
wave functions individually, we examine a dichromatic wave function that is
synthesized from the two interfering wave functions. The physics of
interference is contained in the reduced action for the dichromatic wave
function. As this reduced action is a generator of the motion for the
dichromatic wave function, it determines the dichromatic wave function's
trajectory. The quantum effective mass renders insight into the behavior of the
trajectory. The trajectory in turn renders insight into quantum nonlocality.Comment: 12 pages text, 5 figures. Typos corrected. Author's final submission.
A companion paper to "Welcher Weg? A trajectory representation of a quantum
Young's diffraction experiment", quant-ph/0605121. Keywords: interference,
nonlocality, trajectory representation, entanglement, dwell time, determinis
Investigating Strike-Slip Faulting Parallel to the Icelandic Plate Boundary Using Boundary Element Models
Most faults in Iceland strike roughly parallel to the divergent plate boundary, a part of the North American-Eurasian plate boundary, which would be expected to lead to primarily normal faulting. However, several studies have observed a significant component of rift-parallel strike-slip faulting in Iceland. To investigate these fault kinematics, we use the boundary element method to model fault slip and crustal stress patterns of the Icelandic tectonic system, including a spherical hotspot and uniaxial stress that represents rifting. On a network of faults, we estimate the slip required to relieve traction imposed by hotspot inflation and remote rifting stress and compare the model results with observed slip kinematics, crustal seismicity, and geodetic data. We note a good fit between model-predicted and observed deformation metrics, with both indicating significant components of normal and strike-slip faulting and consistency between recent data and longer-term records of geologic fault slip. Possible stress permutations between steeply plunging Ï1 and Ï2 axes are common in our models, suggesting that localized stress perturbations may impact strike-slip faulting. Some increases in model complexity, including older hotspot configurations and allowing fault opening to simulate dike intrusion, show improvement to model fit in select regions. This work provides new insight into the physical mechanisms driving faulting styles within Iceland away from the current active plate boundary, implying that a significant portion of observed strike-slip faulting is likely caused by the combined effects of tectonic rifting, hotspot impacts, and mechanical interactions across the fault network
ELECTROSTATIC BODY-MOTION REGISTRATION AND THE HUMAN ANTENNA-RECEIVER EFFECT: A NEW METHOD FOR INVESTIGATING INTERPERSONAL DYNAMICAL ENERGY SYSTEM INTERACTIONS
This paper documents that it is possible to measure electromagnetic fields created by physical movements of the human body-termed electrostatic body-motion effects-using readily available EEG amplifiers, and that it possible to measure the human body's capability to serve as an antenna and/or receiver for these electrostatic movements-termed the human antenna-receiver effect. Following the observation by Green et al (1991)1 that small body-motions could be detected by electrometers attached to copper walls, three experiments were conducted measuring the effects of hand-motions and foot-motions using DC amplifiers (the Synamps System by Neuroscan). Clear hand-motion and foot-motion effects could be recorded using a standard electrode box as an antenna. The electrostatic motion effect was attenuated as a function of distance of the motions from the electrode box, and by placing a wire mesh shield over the electrode box. The human body was discovered to funcrion as a strong antenna and/or receiver for electrostatic body-motions. The findings indicate that electrostatic body-motions and the human antenna-receiver effect are easily measurable, and may serve as a new method for investigating interpersonal dynamic energy system interactions in psychology, medicine and healing
Asymptotics of 4d spin foam models
We study the asymptotic properties of four-simplex amplitudes for various
four-dimensional spin foam models. We investigate the semi-classical limit of
the Ooguri, Euclidean and Lorentzian EPRL models using coherent states for the
boundary data. For some classes of geometrical boundary data, the asymptotic
formulae are given, in all three cases, by simple functions of the Regge action
for the four-simplex geometry.Comment: 10 pages, Proceedings for the 2nd Corfu summer school and workshop on
quantum gravity and quantum geometry, talk given by Winston J. Fairbair
Urodynamic evaluation of hypospadias repair
Purpose: We performed a cross-sectional evaluation of voiding in a population undergoing hypospadias repair to determine whether patients had urinary obstruction at various intervals of followup after the last operation. Materials and Methods: Of approximately 600 patients undergoing hypospadias repair at our department during a 30-year interval 175, 40 months to 66 years old were evaluated. Therefore, we created a cross-sectional study group for evaluation of voiding function. All patients had undergone the final operation for hypospadias at least 1 year previously and were toilet trained. Severity of the initial hypospadias was scored together with the operative technique. Parameters evaluated were medical history, physical examination and uroflowmetry using a rotating disk. Uroflowmetry data (maximum flow rate and voided volume) were plotted in age-related nomograms in 4 different age groups: less than 8 (28 patients), 9 to 14 (18), 15 to 21 (39) and more than 21 (91) years old. All flow charts were evaluated by 2 of us (J. F. A. v. d. W. and E. B.). Results: The severity of initial disease was grade 1 in 30% of the patients, grade 2 in 57%, grade 3 in 10%, grade 4 in 2% and unknown in 2%. The operative technique performed was a van der Meulen repair in 113 patients (65%), a combined Byars-Denis Browne repair in 56 (32%) and miscellaneous in 6 (3%). According to the uroflowmetry nomograms there was a tendency for an increased number of patients to have a normal maximum flow rate with increasing age. A total of 14 patients had a flow curve that suggested distal urethra obstruction and none was symptomatic. There was no difference in uroflowmetry characteristics regarding the operative technique. Conclusions: No difference in uroflowmetry could be established among the operations. There seemed to be a tendency towards improvement in uroflowmetry with increasing followup. There was no direct relationship between low maximum flow rates and clinical apparent obstruction
Would Functional Agricultural Foods Improve Human Health?
Concern over diet-health relationships has moved to the forefront of public health concerns in the UK and much of the developed world. It has been estimated, for example, that obesity costs the UK National Health Service up to ÂŁ6b per year (Rayner and Scarborough, 2005), but if all consumers were to follow recommended healthy eating guidelines there would be major implications for food consumption, land use and international trade (Srinivasan et al, 2006). This is unlikely to happen, at least in the short term, but it is realistic to anticipate some dietary adjustment toward the recommendations, resulting in an improvement in diet quality (Mazzocchi et al, 2007). Although consumers are reluctant to make major changes to their diets, they may be prepared to substitute existing foods for healthier alternatives. Three of the most prominent nutritional recommendations are to consume more fruit and vegetables, which contain phytochemicals beneficial to health, reduce consumption of saturated fatty acids (SFA) and increase intake of long-chain n-3 fatty acids (FA). In the first case, consumption of fruit and vegetables has been stable at around three 80 g portions per person per day according to the Health Survey for England. It is estimated that 42,200 deaths per year could be avoided in England and 411,000 Quality Adjusted Life Years (QALYs) could be saved if fruit and vegetable consumption were increased to the recommended 5 portions per day (Ofcom 2006). As well as continuing to encourage people to eat more, it could be desirable to âintensifyâ the beneficial phytochemical content of existing fruit and vegetables.Agribusiness, Agricultural and Food Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization,
Which Results to Return: Subjective Judgments in Selecting Medically Actionable Genes
Background: Advances in genomics have led to calls for returning information about medically actionable genes (MAGs) to patients, research subjects, biobank participants, and through screening programs, the general adult population. Which MAGs are returned affects the harms and benefits of every genetic testing endeavor. Despite published recommendations of selection criteria for MAGs to return, scant data exist regarding how decision makers actually apply such criteria
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