Radiatively-Driven Outflows and Avoidance of Common-Envelope Evolution in Close Binaries

Recent work on Cygnus X-2 suggests that neutron-star or black-hole binaries survive highly super-Eddington mass transfer rates without undergoing common-envelope evolution. We suggest here that the accretion flows in such cases are radiation pressure-dominated versions of the "ADIOS" picture proposed by Blandford and Begelman (1999), in which almost all the mass is expelled from large radii in the accretion disk. We estimate the maximum radius from which mass loss is likely to occur, and show that common-envelope evolution is probably avoided in any binary in which a main-sequence donor transfers mass on a thermal timescale to a neutron star or black hole, even though the mass transfer rate may reach values of 0.001 solar masses per year. This conclusion probably applies also to donors expanding across the Hertzsprung gap, provided that their envelopes are radiative. SS433 may be an example of a system in this state.Comment: 4 pages, submitted to Astrophysical Journal Letters, 26 March 199

Nutrition and indoor cycling : A cross-sectional analysis of carbohydrate intake for online racing and training

Cycling is a sport characterised by high training load, and adequate nutrition is essential for training and race performance. With the increased popularity of indoor trainers, cyclists have a unique opportunity to practice and implement key nutritional strategies. This study aimed to assess carbohydrate (CHO) intake of cyclists training or racing in this unique scenario for optimising exercise nutrition. A mixed-methods approach consisting of a multiple-pass self-report food recall and questionnaire was used to determine total CHO intake pre, during and post-training or racing using a stationary trainer and compared with current guidelines for endurance exercise. Sub-analyses were also made for higher ability cyclists (>4 W/kg functional threshold power), races v. non-races and ‘key’ training sessions. Mean CHO intake pre and post-ride was 0·7 (SD 0·6) and 1·0 (SD 0·8) g kg/BM and 39·3 (SD 27·5) g/h during training. CHO intake was not different for races (pre/during/post, P = 0·31, 0·23, 0·18, respectively), ‘key sessions’ (P = 0·26, 0·89, 0·98) or higher ability cyclists (P = 0·26, 0·76, 0·45). The total proportion of cyclists who failed to meet CHO recommendations was higher than those who met guidelines (pre = 79 %, during = 86 %, post = 89 %). Cyclists training or racing indoors do not meet current CHO recommendations for cycling performance. Due to the short and frequently high-intensity nature of some sessions, opportunity for during exercise feeding may be limited or unnecessary

Consumer Appeal of Injection IML Packaging vs. Similarly Decorated Glass Jars, Composite Cans, and Metal Cans Using Eye Tracking Technology

Customers shopped for a set of control packages (i.e. decorated composite cans, metal cans, and glass jars) vs. similarly decorated experimental packaging {i.e. injection in-mold labeled (IML) plastic containers} in CUShopTM. Sonoco Institute of Packaging Design and Graphics, Clemson University. The objective was to determine if IML decoration affected a shopper’s point of sale interest vs. non-IML methods of package decoration. Eighty-one volunteer participants wore eye tracking glasses and shopped for 5 products (3 of interest) over three days. Day one, control packaging data was collected; day two, IML packaging data was collected; day three, control and IML packaging positioned side-by-side data was collected. Quantitative analysis was completed for eye movements from each participant and in aggregate. Qualitative observations were recorded via a post experiment survey each day. Results showed that participants trended towards finding IML packaging faster than any of the controls; however, there were no statistically significant differences (P \u3c 0.05) between the IML decorated samples vs. the control decorated samples for the Time to First Fixation (TTFF) and Total Fixation Duration (TFD) metrics. Because a fundamental difference between control packages and IML containers was the decorating process, the many benefits of IML were not represented in this study. It was hypothesized that the IML containers would rank equal to or better than the control packages. From the perspective of the researchers, data is compelling because IML packaging is new to the tested categories; and it was compared against traditional packages and products. The use of eye tracking applied to injection IML packaging is also novel in this field

Inner and outer radial density functions in correlated two-electron systems

A method is presented for determining inner and outer one-electron radial density functions for two electron systems by partitioning the fully correlated two-electron radial density function. This is applied to the helium isolectronic series (Z=1 to 10 and 100) and the critical nuclear charge system, which has the minimum charge for which the atomic system has at least one bound state, to separate out the motions of the two electrons in both weakly and strongly correlated systems. It is found that the inner electron experiences an anti-shielding effect due to the perturbation by the other electron which increases with increasing Z. For the weakly bound systems the inner radial density distribution closely resembles that of a hydrogenic atom with the outer radial density distribution becoming very diffuse

Automated classification of three-dimensional reconstructions of coral reefs using convolutional neural networks

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hopkinson, B. M., King, A. C., Owen, D. P., Johnson-Roberson, M., Long, M. H., & Bhandarkar, S. M. Automated classification of three-dimensional reconstructions of coral reefs using convolutional neural networks. PLoS One, 15(3), (2020): e0230671, doi: 10.1371/journal.pone.0230671.Coral reefs are biologically diverse and structurally complex ecosystems, which have been severally affected by human actions. Consequently, there is a need for rapid ecological assessment of coral reefs, but current approaches require time consuming manual analysis, either during a dive survey or on images collected during a survey. Reef structural complexity is essential for ecological function but is challenging to measure and often relegated to simple metrics such as rugosity. Recent advances in computer vision and machine learning offer the potential to alleviate some of these limitations. We developed an approach to automatically classify 3D reconstructions of reef sections and assessed the accuracy of this approach. 3D reconstructions of reef sections were generated using commercial Structure-from-Motion software with images extracted from video surveys. To generate a 3D classified map, locations on the 3D reconstruction were mapped back into the original images to extract multiple views of the location. Several approaches were tested to merge information from multiple views of a point into a single classification, all of which used convolutional neural networks to classify or extract features from the images, but differ in the strategy employed for merging information. Approaches to merging information entailed voting, probability averaging, and a learned neural-network layer. All approaches performed similarly achieving overall classification accuracies of ~96% and >90% accuracy on most classes. With this high classification accuracy, these approaches are suitable for many ecological applications.This study was funded by grants from the Alfred P. Sloan Foundation (BMH, BR2014-049; https://sloan.org), and the National Science Foundation (MHL, OCE-1657727; https://www.nsf.gov). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

Sacral Neuromodulation in Children

Sacral neuromodulation (SNM) has emerged as a treatment option for refractory lower urinary tract and bowel dysfunction in children. SNM is typically reserved for a select population of children who have failed an extended period of behavioral modification, biofeedback, and pharmacologic therapy. The surgical techniques for SNM in children are analogous to those in adults and include both one- and two-stage procedures as well as a peripheral nerve evaluation with the InterStim® system (Medtronic, Minneapolis, MN). Most studies have observed not only an improvement in symptoms and quality of life in children undergoing SNM for non-neurogenic and neurogenic lower urinary tract dysfunction but also a much higher reoperative rate than in adults. Further high-quality research is necessary to corroborate the results of earlier studies and to better define the indications for SNM in children

What is on Tap? The Role of Spin in Compact Objects and Relativistic Jets

We examine the role of spin in launching jets from compact objects across the mass scale. Our work includes a total of 37 Seyferts, 11 stellar-mass black holes, and 13 neutron stars. We find that when the Seyfert reflection lines are modeled with Gaussian line features (a crude proxy for inner disk radius and therefore spin), only a slight inverse correlation is found between the Doppler-corrected radio luminosity at 5 GHz (a proxy for jet power) and line width. When the Seyfert reflection features are fit with relativistically-blurred disk reflection models that measure spin, there is a tentative positive correlation between the Doppler-corrected radio luminosity and the spin measurement. Further, when we include stellar-mass black holes in the sample, to examine the effects across the mass scale, we find a slightly stronger correlation with radio luminosity per unit mass and spin, at a marginal significance (2.3 sigma confidence level). Finally, when we include neutron stars, in order to probe lower spin values, we find a positive correlation (3.3 sigma confidence level) between radio luminosity per unit mass and spin. Although tentative, these results suggest that spin may have a role in determining the jet luminosity. In addition, we find a slightly more significant correlation (4.4 sigma confidence level) between radio luminosity per Bolometric luminosity and spin, using our entire sample of black holes and neutrons stars. Again, although tentative, these relations point to the possibility that the mass accretion rate, i.e. Bolometric luminosity, is also important in determining the jet luminosity, in addition to spin. Our analysis suggests that mass accretion rate and disk or coronal magnetic field strength may be the "throttle" in these compact systems, to which the Eddington limit and spin may set the maximum jet luminosity that can be achieved.Comment: 14 pages, 13 Figures, ApJ Accepte

Exact Performance of Concatenated Quantum Codes

When a logical qubit is protected using a quantum error-correcting code, the net effect of coding, decoherence (a physical channel acting on qubits in the codeword) and recovery can be represented exactly by an effective channel acting directly on the logical qubit. In this paper we describe a procedure for deriving the map between physical and effective channels that results from a given coding and recovery procedure. We show that the map for a concatenation of codes is given by the composition of the maps for the constituent codes. This perspective leads to an efficient means for calculating the exact performance of quantum codes with arbitrary levels of concatenation. We present explicit results for single-bit Pauli channels. For certain codes under the symmetric depolarizing channel, we use the coding maps to compute exact threshold error probabilities for achievability of perfect fidelity in the infinite concatenation limit.Comment: An expanded presentation of the analytic methods and results from quant-ph/0111003; 13 pages, 6 figure

Estimating Partisan Bias of the Electoral College Under Proposed Changes in Elector Apportionment

In the election for President of the United States, the Electoral College is the body whose members vote to elect the President directly. Each state sends a number of delegates equal to its total number of representatives and senators in Congress; all but two states (Nebraska and Maine) assign electors pledged to the candidate that wins the state’s plurality vote. We investigate the effect on presidential elections if states were to assign their electoral votes according to results in each congressional district, and conclude that the direct popular vote and the current electoral college are both substantially fairer compared to those alternatives where states would have divided their electoral votes by congressional district