Alternative Fourier Expansions for Inverse Square Law Forces

Few-body problems involving Coulomb or gravitational interactions between pairs of particles, whether in classical or quantum physics, are generally handled through a standard multipole expansion of the two-body potentials. We discuss an alternative based on a compact, cylindrical Green's function expansion that should have wide applicability throughout physics. Two-electron "direct" and "exchange" integrals in many-electron quantum systems are evaluated to illustrate the procedure which is more compact than the standard one using Wigner coefficients and Slater integrals.Comment: 10 pages, latex/Revtex4, 1 figure

Cardiac rhythm device identification using neural networks

Background Medical staff often need to determine the model of a pacemaker or defibrillator (cardiac rhythm devices) quickly and accurately. Current approaches involve comparing a device’s X-ray appearance with a manual flow chart. We aimed to see whether a neural network could be trained to perform this task more accurately. Methods and Results We extracted X-ray images of 1676 devices, comprising 45 models from 5 manufacturers. We developed a convolutional neural network to classify the images, using a training set of 1451 images. The testing set was a further 225 images, consisting of 5 examples of each model. We compared the network’s ability to identify the manufacturer of a device with those of cardiologists using a published flow-chart. The neural network was 99.6% (95% CI 97.5 to 100) accurate in identifying the manufacturer of a device from an X-ray, and 96.4% (95% CI 93.1 to 98.5) accurate in identifying the model group. Amongst 5 cardiologists using the flow-chart, median manufacturer accuracy was 72.0% (range 62.2% to 88.9%), and model group identification was not possible. The network was significantly superior to all of the cardiologists in identifying the manufacturer (p < 0.0001 against the median human; p < 0.0001 against the best human). Conclusions A neural network can accurately identify the manufacturer and even model group of a cardiac rhythm device from an X-ray, and exceeds human performance. This system may speed up the diagnosis and treatment of patients with cardiac rhythm devices and it is publicly accessible online

Loss of the ciliary protein Chibby1 in mice leads to exocrine pancreatic degeneration and pancreatitis

Primary cilia protrude from the apical surface of many cell types and act as a sensory organelle that regulates diverse biological processes ranging from chemo- and mechanosensation to signaling. Ciliary dysfunction is associated with a wide array of genetic disorders, known as ciliopathies. Polycystic lesions are commonly found in the kidney, liver, and pancreas of ciliopathy patients and mouse models. However, the pathogenesis of the pancreatic phenotype remains poorly understood. Chibby1 (Cby1), a small conserved coiled-coil protein, localizes to the ciliary base and plays a crucial role in ciliogenesis. Here, we report that Cby1-knockout (KO) mice develop severe exocrine pancreatic atrophy with dilated ducts during early postnatal development. A significant reduction in the number and length of cilia was observed in Cby1-KO pancreta. In the adult Cby1-KO pancreas, inflammatory cell infiltration and fibrosis were noticeable. Intriguingly, Cby1-KO acinar cells showed an accumulation of zymogen granules (ZGs) with altered polarity. Moreover, isolated acini from Cby1-KO pancreas exhibited defective ZG secretion in vitro. Collectively, our results suggest that, upon loss of Cby1, concomitant with ciliary defects, acinar cells accumulate ZGs due to defective exocytosis, leading to cell death and progressive exocrine pancreatic degeneration after birth

The kinematics of coronal mass ejections using multiscale methods

The diffuse morphology and transient nature of coronal mass ejections (CMEs) make them difficult to identify and track using traditional image processing techniques. We apply multiscale methods to enhance the visibility of the faint CME front. This enables an ellipse characterisation to objectively study the changing morphology and kinematics of a sample of events imaged by the Large Angle Spectrometric Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO) and the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) onboard the Solar Terrestrial Relations Observatory (STEREO). The accuracy of these methods allows us to test the CMEs for non-constant acceleration and expansion. We exploit the multiscale nature of CMEs to extract structure with a multiscale decomposition, akin to a Canny edge detector. Spatio-temporal filtering highlights the CME front as it propagates in time. We apply an ellipse parameterisation of the front to extract the kinematics (height, velocity, acceleration) and changing morphology (width, orientation). The kinematic evolution of the CMEs discussed in this paper have been shown to differ from existing catalogues. These catalogues are based upon running-difference techniques that can lead to over-estimating CME heights. Our resulting kinematic curves are not well-fitted with the constant acceleration model. It is shown that some events have high acceleration below $\sim$5 R_{\sun}. Furthermore, we find that the CME angular widths measured by these catalogues are over-estimated, and indeed for some events our analysis shows non-constant CME expansion across the plane-of-sky.Comment: 10 pages, 13 figures, accepted for publicatio

The Vehicle, Fall 1994

Table of Contents Poetry Noah\u27s WifeJennifer Moropage 8-9 The Intensity of a BreathHeather Anne Winterspage 10-11 When I Was RainNicole Moonpage 11 Wreckage at Low Tide, After a Storm On Cape FearMatt Parkspage 12-14 two belowKeith Spearpage 16 HeatScott Langrenpage 17 Plastic Shard WordsMatthew J. Nelsonpage 18 Mr. Snowplow ManMartin Paul Brittpage 19 Carpe DiemMichael Lairpage 19 untitledWalt Howardpage 20 The GameKellie J. Olsenpage 21 AT PEACEJennifer Surmanpage 22 SawdustSue Songerpage 23 Photography Unbound RealitiesKris Quiriconipage 26 untitled Mark Porter page 27 untitled Mark Porter page 28 untitled Mark Porter page 29 Prose I am Here...RememberingJ. Dylan McNeillpage 32-34 RecognitionSue Songerpage 35-36 SACCADICSteve Beinpage 37-40 The BurnBryan Levekpage 41-45 Biographiespage 46-48https://thekeep.eiu.edu/vehicle/1063/thumbnail.jp

The Vehicle, Fall 1994

Table of Contents Poetry Noah\u27s WifeJennifer Moropage 8-9 The Intensity of a BreathHeather Anne Winterspage 10-11 When I Was RainNicole Moonpage 11 Wreckage at Low Tide, After a Storm On Cape FearMatt Parkspage 12-14 two belowKeith Spearpage 16 HeatScott Langrenpage 17 Plastic Shard WordsMatthew J. Nelsonpage 18 Mr. Snowplow ManMartin Paul Brittpage 19 Carpe DiemMichael Lairpage 19 untitledWalt Howardpage 20 The GameKellie J. Olsenpage 21 AT PEACEJennifer Surmanpage 22 SawdustSue Songerpage 23 Photography Unbound RealitiesKris Quiriconipage 26 untitled Mark Porter page 27 untitled Mark Porter page 28 untitled Mark Porter page 29 Prose I am Here...RememberingJ. Dylan McNeillpage 32-34 RecognitionSue Songerpage 35-36 SACCADICSteve Beinpage 37-40 The BurnBryan Levekpage 41-45 Biographiespage 46-48https://thekeep.eiu.edu/vehicle/1063/thumbnail.jp

Non-monotonic variation with salt concentration of the second virial coefficient in protein solutions

The osmotic virial coefficient $B_2$ of globular protein solutions is calculated as a function of added salt concentration at fixed pH by computer simulations of the ``primitive model''. The salt and counter-ions as well as a discrete charge pattern on the protein surface are explicitly incorporated. For parameters roughly corresponding to lysozyme, we find that $B_2$ first decreases with added salt concentration up to a threshold concentration, then increases to a maximum, and then decreases again upon further raising the ionic strength. Our studies demonstrate that the existence of a discrete charge pattern on the protein surface profoundly influences the effective interactions and that non-linear Poisson Boltzmann and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory fail for large ionic strength. The observed non-monotonicity of $B_2$ is compared to experiments. Implications for protein crystallization are discussed.Comment: 43 pages, including 17 figure

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described

National culture and tourist destination choice in the UK and Venezuela: an exploratory and preliminary study

National culture determines consumer attitudes and behaviour. While this holds true for tourism consumption, little research has sought to better understand the effect of culture on tourist destination choice. The geographical scope of analysis has also been restricted. This study employs the Hofstede’s cultural dimensions framework to conduct an exploratory, qualitative evaluation of the influence of the tourist cultural background on destination choice. It focuses on the UK and Venezuela, the two countries with significant cultural differences and forecast growth in outbound tourism. The study shows the distinct role of culture in tourist preferences for destination choice and structure of travel groups. The effect of culture is also recorded in how tourists research destinations prior to visit and perceive travel risks, thus ultimately influencing their motivation to travel. Recommendations are developed on how to integrate knowledge on the cultural background of tourists into tourism management and policy-making practices

Kernel Flow:a high channel count scalable time-domain functional near-infrared spectroscopy system

Significance: Time-domain functional near-infrared spectroscopy (TD-fNIRS) has been considered as the gold standard of noninvasive optical brain imaging devices. However, due to the high cost, complexity, and large form factor, it has not been as widely adopted as continuous wave NIRS systems. Aim: Kernel Flow is a TD-fNIRS system that has been designed to break through these limitations by maintaining the performance of a research grade TD-fNIRS system while integrating all of the components into a small modular device. Approach: The Kernel Flow modules are built around miniaturized laser drivers, custom integrated circuits, and specialized detectors. The modules can be assembled into a system with dense channel coverage over the entire head. Results: We show performance similar to benchtop systems with our miniaturized device as characterized by standardized tissue and optical phantom protocols for TD-fNIRS and human neuroscience results. Conclusions: The miniaturized design of the Kernel Flow system allows for broader applications of TD-fNIRS.</p