Intrinsic symmetry groups of links with 8 and fewer crossings

We present an elementary derivation of the "intrinsic" symmetry groups for knots and links of 8 or fewer crossings. The standard symmetry group for a link is the mapping class group \MCG(S^3,L) or \Sym(L) of the pair $(S^3,L)$. Elements in this symmetry group can (and often do) fix the link and act nontrivially only on its complement. We ignore such elements and focus on the "intrinsic" symmetry group of a link, defined to be the image $\Sigma(L)$ of the natural homomorphism \MCG(S^3,L) \rightarrow \MCG(S^3) \cross \MCG(L). This different symmetry group, first defined by Whitten in 1969, records directly whether $L$ is isotopic to a link $L'$ obtained from $L$ by permuting components or reversing orientations. For hyperbolic links both \Sym(L) and $\Sigma(L)$ can be obtained using the output of \texttt{SnapPea}, but this proof does not give any hints about how to actually construct isotopies realizing $\Sigma(L)$. We show that standard invariants are enough to rule out all the isotopies outside $\Sigma(L)$ for all links except $7^2_6$, $8^2_{13}$ and $8^3_5$ where an additional construction is needed to use the Jones polynomial to rule out "component exchange" symmetries. On the other hand, we present explicit isotopies starting with the positions in Cerf's table of oriented links which generate $\Sigma(L)$ for each link in our table. Our approach gives a constructive proof of the $\Sigma(L)$ groups.Comment: 72 pages, 66 figures. This version expands the original introduction into three sections; other minor changes made for improved readabilit

Jack Voltaic 3.0 Cyber Research Report Executive Summary

This condensed Executive summary provides an overview of the information contained in the full JV 3.0 Cyber Research Report

The physiological stress response to anaerobic exercise is altered following sodium bicarbonate supplementation

Sodium bicarbonate (NaHCO3) is a nutritional aid that is proposed to enhance performance by reducing the state of exercise induced acidosis, however research is currently equivocal. Despite this, most research still focuses on its effects upon performance, and not whether the reduced acidosis impacts upon any other factors related to exercise. There is some research to suggest that such a reduction in [H+] can attenuate a number of physiological stress pathways such as stress hormones (1, 4), heat shock protein 72 (HSP72) and oxidative stress (3), suggesting a potential role in exercise recovery. However there are some limitations with this previous research as work intensities were not controlled for, hence making comparisons between treatments difficult. Also limited markers of stress were measured despite the physiological stress response being multi-faceted. The aim of this study was to examine whether the ingestion of NaHCO3 would influence the expression of several markers of stress measured simultaneously, following a work controlled anaerobic exercise

Jack Voltaic 3.0 Cyber Research Report

The Jack Voltaic (JV) Cyber Research project is an innovative, bottom-up approach to critical infrastructure resilience that informs our understanding of existing cybersecurity capabilities and identifies gaps. JV 3.0 contributed to a repeatable framework cities and municipalities nationwide can use to prepare. This report on JV 3.0 provides findings and recommendations for the military, federal agencies, and policy makers

Cardiovascular Fitness and Creativity in Children

Creativity permeates virtually all aspects of humanity, as human-made creations and connections are all around us. Another common human phenomenon is aerobic exercise, and its corresponding, longer-term condition, cardiovascular fitness. Multiple studies support cardiovascular fitness as a positive correlate of, and aerobic exercise as an inducer of, cognitive benefits and both structural and functional brain changes, across ages and species. From an understanding of the relationships between aerobic exercise/cardiovascular fitness and certain neurocognitive changes, along with an understanding of the neural processes underlying creativity, a theoretical psychophysiological relationship between aerobic exercise/cardiovascular fitness and creativity appears. There is indirect support that neural and behavioral changes induced by exercise, or consistent with high cardiovascular fitness, may result in improved creativity. However, there is currently little research examining this relationship. Additionally, the relationship of aerobic exercise/cardiovascular fitness and creativity has seemingly been unexamined in children. In this study, cardiovascular fitness levels of eight 9-11 year olds, as determined by a maximal oxygen consumption test, were related to both the number and uniqueness of appropriate responses in creativity tasks. There were no significant correlations between cardiovascular fitness and these creativity measures. The limited sample size hindered the ability to ascertain a more complete analysis of these relationships. Future research should include a larger sample size, take into consideration factors such as motivation, sleep, and stress, and perform neuroimaging. These would allow a more comprehensive understanding of the relationship between cardiovascular fitness and creativity.Ope

Resting state functional connectivity provides mechanistic predictions of future changes in sedentary behavior

Sedentary behaviors are increasing at the cost of millions of dollars spent in health care and productivity losses due to physical inactivity-related deaths worldwide. Understanding the mechanistic predictors of sedentary behaviors will improve future intervention development and precision medicine approaches. It has been posited that humans have an innate attraction towards effort minimization and that inhibitory control is required to overcome this prepotent disposition. Consequently, we hypothesized that individual differences in the functional connectivity of brain regions implicated in inhibitory control and physical effort decision making at the beginning of an exercise intervention in older adults would predict the change in time spent sedentary over the course of that intervention. In 143 healthy, low-active older adults participating in a 6-month aerobic exercise intervention (with three conditions: walking, dance, stretching), we aimed to use baseline neuroimaging (resting state functional connectivity of two a priori defined seed regions), and baseline accelerometer measures of time spent sedentary to predict future pre-post changes in objectively measured time spent sedentary in daily life over the 6-month intervention. Our results demonstrated that functional connectivity between (1) the anterior cingulate cortex and the supplementary motor area and (2) the right anterior insula and the left temporoparietal/temporooccipital junction, predicted changes in time spent sedentary in the walking group. Functional connectivity of these brain regions did not predict changes in time spent sedentary in the dance nor stretch and tone conditions, but baseline time spent sedentary was predictive in these conditions. Our results add important knowledge toward understanding mechanistic associations underlying complex out-of-session sedentary behaviors within a walking intervention setting in older adults

Francisella tularensis in the United States

Subpopulations A.I and A.II. of Francisella tularensis subsp. tularensis are associated with unique biotic and abiotic factors that maintain disease foci

Vortex Fiber Nulling for Exoplanet Observations: Implementation and First Light

Vortex fiber nulling (VFN) is a single-aperture interferometric technique for detecting and characterizing exoplanets separated from their host star by less than a diffracted beam width. VFN uses a vortex mask and single mode fiber to selectively reject starlight while coupling off-axis planet light with a simple optical design that can be readily implemented on existing direct imaging instruments that can feed light to an optical fiber. With its axially symmetric coupling region peaking within the inner working angle of conventional coronagraphs, VFN is more efficient at detecting new companions at small separations than conventional direct imaging, thereby increasing the yield of on-going exoplanet search campaigns. We deployed a VFN mode operating in K band ($2.0{-}2.5~\mu$m) on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck II Telescope. In this paper we present the instrument design of this first on-sky demonstration of VFN and the results from on-sky commissioning, including planet and star throughput measurements and predicted flux-ratio detection limits for close-in companions. The instrument performance is shown to be sufficient for detecting a companion $10^3$ times fainter than a $5^{\mathrm{th}}$ magnitude host star in 1 hour at a separation of 50 mas (1.1$\lambda/D$). This makes the instrument capable of efficiently detecting substellar companions around young stars. We also discuss several routes for improvement that will reduce the required integration time for a detection by a factor ${>}$3.Comment: 26 pages, 5 figures; Accepted to JATI