Mapping Dark Matter in the Milky Way using Normalizing Flows and Gaia DR3

We present a novel, data-driven analysis of Galactic dynamics, using unsupervised machine learning -- in the form of density estimation with normalizing flows -- to learn the underlying phase space distribution of 6 million nearby stars from the Gaia DR3 catalog. Solving the collisionless Boltzmann equation with the assumption of approximate equilibrium, we calculate -- for the first time ever -- a model-free, unbinned, fully 3D map of the local acceleration and mass density fields within a 3 kpc sphere around the Sun. As our approach makes no assumptions about symmetries, we can test for signs of disequilibrium in our results. We find our results are consistent with equilibrium at the 10% level, limited by the current precision of the normalizing flows. After subtracting the known contribution of stars and gas from the calculated mass density, we find clear evidence for dark matter throughout the analyzed volume. Assuming spherical symmetry and averaging mass density measurements, we find a local dark matter density of $0.47\pm 0.05\;\mathrm{GeV/cm}^3$. We fit our results to a generalized NFW, and find a profile broadly consistent with other recent analyses.Comment: 19 pages, 13 figures, 3 table

Assessing the Sociology of Sport on Changing Masculinities and Homophobia

Sport sociology has been intricately tied with the \ud study of masculinities since the early 1990s \ud in the West. The field was first established in exa\ud mining white male athlete’s masculinity, \ud particularly noting its root in homophobia in the f\ud orging of a hegemonic form of masculinity. \ud However, contemporary masculinity scholarship shows\ud a changed relationship between \ud men’s masculinity and hegemonic dominance. Current \ud research examines men’s \ud masculinities in an era of decreased homohysteria, \ud finding teamsport athletes inclusive of \ud homosexuality. This simultaneously permits heterose\ud xual men to live within greatly \ud expanded gender terrains. The challenge for sport s\ud ociologist concerned with masculinities \ud today, is to expand the locus of investigation to t\ud he intersectional demographics of varying \ud races, geographical locations, religious beliefs, a\ud ge and other important demographics

Acidosis Decreases c-Myc Oncogene Expression in Human Lymphoma Cells: A Role for the Proton-Sensing G Protein-Coupled Receptor TDAG8

Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65) is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs). Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression

Control of Positronium Excitation Laser for the Production of Positive Antihydrogen in GBAR

This summer I assisted the GBAR experiment with several aspects of the laser system used for the excitation of positronium. GBAR (Gravitational Behavior of Antihydrogen at Rest) aims precisely determine how antimatter moves due to the Earth's gravity. At it's core, the premise of this measurement is simple enough that it be described by basic kinematics: A neutral anti-particle is dropped from a known height into free fall, after some known time a signal is detected when it annihilates at one end of a free fall chamber. You may then ask what the gravitational strength of the pull on that particle must have been to have seen a signal at that time. Producing antihydrogen is dicult, generating positive antihydrogen has not been done. Once positive antihydrogen is produced, getting enough events to make a statistically signicant conclusion is a challenge itself. This experiment will test CPT, the weak equivalence principle for antimatter, and could conrm or deny the existence of repulsive gravity (anti-gravity) while developing novel techniques for probing antimatter. Overcoming these challenges opens new doors in antimatter physics and will directly conrm or deny fundamental principles of physics

Measuring Galactic Dark Matter through Unsupervised Machine Learning

Measuring the density profile of dark matter in the Solar neighborhood has important implications for both dark matter theory and experiment. In this work, we apply autoregressive flows to stars from a realistic simulation of a Milky Way-type galaxy to learn -- in an unsupervised way -- the stellar phase space density and its derivatives. With these as inputs, and under the assumption of dynamic equilibrium, the gravitational acceleration field and mass density can be calculated directly from the Boltzmann Equation without the need to assume either cylindrical symmetry or specific functional forms for the galaxy's mass density. We demonstrate our approach can accurately reconstruct the mass density and acceleration profiles of the simulated galaxy, even in the presence of Gaia-like errors in the kinematic measurements.Comment: 23 pages, 9 figure

A key role of TRPC channels in the regulation of electromechanical activity of the developing heart.

Aims It is well established that dysfunction of voltage-dependent ion channels results in arrhythmias and conduction disturbances in the foetal and adult heart. However, the involvement of voltage-insensitive cationic TRPC (transient receptor potential canonical) channels remains unclear. We assessed the hypothesis that TRPC channels play a crucial role in the spontaneous activity of the developing heart.Methods and results TRPC isoforms were investigated in isolated hearts obtained from 4-day-old chick embryos. Using RT-PCR, western blotting and co-immunoprecipitation, we report for the first time that TRPC1, 3, 4, 5, 6, and 7 isoforms are expressed at the mRNA and protein levels and that they can form a macromolecular complex with the alpha 1C subunit of the L-type voltage-gated calcium channel (Cav1.2) in atria and ventricle. Using ex vivo electrocardiograms, electrograms of isolated atria and ventricle and ventricular mechanograms, we found that inhibition of TRPC channels by SKF-96365 leads to negative chrono-, dromo-, and inotropic effects, prolongs the QT interval, and provokes first-and second-degree atrioventricular blocks. Pyr3, a specific antagonist of TRPC3, affected essentially atrioventricular conduction. On the other hand, specific blockade of the L-type calcium channel with nifedipine rapidly stopped ventricular contractile activity without affecting rhythmic electrical activity.Conclusions These results give new insights into the key role that TRPC channels, via interaction with the Cav1.2 channel, play in regulation of cardiac pacemaking, conduction, ventricular activity, and contractility during cardiogenesis