Search for transient ultralight dark matter signatures with networks of precision measurement devices using a Bayesian statistics method

We analyze the prospects of employing a distributed global network of precision measurement devices as a dark matter and exotic physics observatory. In particular, we consider the atomic clocks of the Global Positioning System (GPS), consisting of a constellation of 32 medium-Earth orbit satellites equipped with either Cs or Rb microwave clocks and a number of Earth-based receiver stations, some of which employ highly-stable H-maser atomic clocks. High-accuracy timing data is available for almost two decades. By analyzing the satellite and terrestrial atomic clock data, it is possible to search for transient signatures of exotic physics, such as "clumpy" dark matter and dark energy, effectively transforming the GPS constellation into a 50,000km aperture sensor array. Here we characterize the noise of the GPS satellite atomic clocks, describe the search method based on Bayesian statistics, and test the method using simulated clock data. We present the projected discovery reach using our method, and demonstrate that it can surpass the existing constrains by several order of magnitude for certain models. Our method is not limited in scope to GPS or atomic clock networks, and can also be applied to other networks of precision measurement devices.Comment: See also Supplementary Information located in ancillary file

An experimental investigation of internal area ruling for transonic and supersonic channel flow

A simulated transonic rotor channel model was examined experimentally to verify the flow physics of internal area ruling. Pressure measurements were performed in the high speed wind tunnel at transonic speeds with Mach 1.5 and Mach 2 nozzle blocks to get an indication of the approximate shock losses. The results showed a reduction in losses due to internal area ruling with the Mach 1.5 nozzle blocks. The reduction in total loss coefficient was of the order of 17 percent for a high blockage model and 7 percent for a cut-down model

Fast-food offerings in the United States in 1986, 1991, and 2016 show large increases in food variety, portion size, dietary energy, and selected micronutrients

BACKGROUND US national survey data shows fast food accounted for 11% of daily caloric intake in 2007-2010. OBJECTIVE To provide a detailed assessment of changes over time in fast-food menu offerings over 30 years, including food variety (number of items as a proxy), portion size, energy, energy density, and selected micronutrients (sodium, calcium, and iron as percent daily value [%DV]), and to compare changes over time across menu categories (entrées, sides, and desserts). DESIGN Fast-food entrées, sides, and dessert menu item data for 1986, 1991, and 2016 were compiled from primary and secondary sources for 10 popular fast-food restaurants. STATISTICAL ANALYSIS Descriptive statistics were calculated. Linear mixed-effects analysis of variance was performed to examine changes over time by menu category. RESULTS From 1986 to 2016, the number of entrées, sides, and desserts for all restaurants combined increased by 226%. Portion sizes of entrées (13 g/decade) and desserts (24 g/decade), but not sides, increased significantly, and the energy (kilocalories) and sodium of items in all three menu categories increased significantly. Desserts showed the largest increase in energy (62 kcal/decade), and entrées had the largest increase in sodium (4.6% DV/decade). Calcium increased significantly in entrées (1.2%DV/decade) and to a greater extent in desserts (3.9% DV/decade), but not sides, and iron increased significantly only in desserts (1.4% DV/decade). CONCLUSIONS These results demonstrate broadly detrimental changes in fast-food restaurant offerings over a 30-year span including increasing variety, portion size, energy, and sodium content. Research is needed to identify effective strategies that may help consumers reduce energy intake from fast-food restaurants as part of measures to improve dietary-related health issues in the United States.Accepted manuscrip

Searching for physics beyond the Standard Model through the dipole interaction

The magnetic dipole interaction played a central role in the development of QED, and continued in that role for the Standard Model. The muon anomalous magnetic moment has served as a benchmark for models of new physics, and the present experimental value is larger than the standard-model value by more than three standard deviations. The electric dipole moment (EDM) violates parity ({$P$}) and time-reversal ({$T$}) symmetries, and in the context of the $CPT$ theorem, the combination of charge conjugation and parity ($CP$). Since a new source of {$CP$} violation outside of that observed in the $K$ and $B$ meson systems is needed to help explain the baryon asymmetry of the universe, searches for EDMs are being carried out worldwide on a number of systems. The standard-model value of the EDM is immeasurably small, so any evidence for an EDM would signify the observation of new physics. Unique opportunities exist for EDM searches using polarized proton, deuteron or muon beams in storage rings. This talk will provide an overview of the theory of dipole moments, and the relevant experiments. The connection to the transition dipole moment that could produce lepton flavor violating interactions such as $\mu^+ \rightarrow e^+ \gamma$ is also mentioned.Comment: Invited Plenary talk at the 19th International Spin Physics Symposium, Juelic

Fibrocystic Disease of the Pancreas: A Histological Study of the Pancreas in Childhood with a Survey of the Clinical, Epidemiological, and Genetic Features of the Disease

Abstract Not Provided

Casimir-like force arising from quantum fluctuations in a slow-moving dilute Bose-Einstein condensate

We calculate a force due to zero-temperature quantum fluctuations on a stationary object in a moving superfluid flow. We model the object by a localized potential varying only in the flow direction and model the flow by a three-dimensional weakly interacting Bose-Einstein condensate at zero temperature. We show that this force exists for any arbitrarily small flow velocity and discuss the implications for the stability of superfluid flow.Comment: v3: revised discussion of toroidal geometry; replotted figure; minor editorial changes; quantitative and qualitative conclusions remain unchange

First Record and Notes on the Ecology of the Boreal Chorus Frog (Pseudacris maculata) in Arkansas

We report a new state record for Pseudacris maculata from Arkansas. Furthermore, we conducted an ecological study from this population of P. maculata from Benton County. We found this population was primarily breeding during February and March. We also report limited findings on their reproduction, diet, and parasites

On Distribution Functions for Partons in Nuclei

We suggest that a previously conjectured relation between Structure Functions (SF) for nuclei and nucleons also links distribution functions (df) for partons in a nucleus and in nucleons. The above suggestion ensures in principle identical results for SF $F_2^A$, whether computed with hadronic or partonic degrees of freedom. In practice there are differences, due to different $F_2^n$ input. We show that the thus defined nuclear parton distribution functions (pdf) respect standard sumrules. In addition we numerically compare some moments of nuclear SF, and find agreement between results, using hadronic and partonic descriptions. We present computations of EMC ratios for both, and compare those with hadronic predictions and data. In spite of substantial differences in the participating SF, the two representations produce approximately the same EMC ratios. The apparent correlation between the above deviations is ascribed to a sumrule for $F_2^A$. We conclude with a discussion of alternative approaches to nuclear pdf.Comment: 14 pages, 4 figure