‘Bare collapse’, the collapse of a bare stellar core to a neutron star with a very small mass ejection links two seemingly unrelated phenomena: the formation of binary neutron star (BNS) systems and the observations of fast and luminous optical transients. We carried out calculations of the collapse due to electron-capture of both evolutionary and synthetic isentropic bare stellar cores. We find that the collapse results in the formation of a light ∼1.3M⊙ neutron star and an ejection of ∼0.1M⊙ at ∼0.1c. The outer shell of the ejecta is composed of 56Ni that can power an ultra-stripped supernova. The models we explored can explain most of the observed fast optical flares but not the brightest ones. Collapse of cores surrounded by somewhat more massive envelopes can produce larger amounts of 56Ni and explain brighter flares. Alternatively, those events can arise due to interaction of the very energetic ejecta with winds that were ejected from the progenitor a few days before the collapse.

We give a finitary criterion for the convergence of measures on non-elementary geometrically finite hyperbolic orbifolds to the unique measure of maximal entropy. We give an entropy criterion controlling escape of mass to the cusps of the orbifold. Using this criterion, we prove new results on the distribution of collections of closed geodesics on such an orbifold, and as a corollary, we prove the equidistribution of closed geodesics up to a certain length in amenable regular covers of geometrically finite orbifolds.

We give a method to bound the entropy of measures on SLd(R)/ SLd(Z) which are invariant under a one parameter diagonal subgroup, in terms of entropy contributions from the regions of the cusp corresponding to different parabolic groups. These bounds depend on a linear functional on the Lie algebra of the Cartan group. In follow-up papers we will show how to optimize this functional to get good bounds on the cusp entropy and prove that in many cases these bounds are sharp.

Physical activity (PA) is an important recommendation for type 1 diabetes mellitus (T1DM) patients. However, it is commonly thought that higher intensities result in elevating the risk of hypoglycemia immediately after physical activity. We present a case report of a diabetes patient whose blood glucose levels dropped more immediately after low-level aerobic intensity yoga exercises compared with the level drop immediately after high-level aerobic intensity bicycling exercises. The results suggest that due to the difficulty in predicting the glycemic response to physical exercise it is important to better prepare T1DM patients when prescribing them with PA.

Physical activity (PA) is known to improve quality of life during pregnancy and prevent complications, associated with several chronic conditions. In this review, following a succinct summary of relevant physiological aspects of gestation and effort, we summarize recent literature on the effect of PA on fetal condition and newborn outcome as well as on future maternal well-being. Many women become aware of their health issues as they plan pregnancy or become pregnant turning the period of pregnancy into a window of opportunity to establish healthier routines of life for the future. It was found that physical activity leads to less weight gain during pregnancy, as well as lower weight retention. Active women experience improved course of labor as well as lower rates of post-partum depression. As the main concern of the pregnant woman is her future baby's condition, information regarding this is crucial for those practitioners wishing to help women establish new habits, the center of which is regularly scheduled physical activity. It was shown that newborns to active women are less likely to be either macrosomic or small for gestational age. Children of women who kept physically active during pregnancy had less autistic spectrum disorders and better brain growth, as well as less sleeping disorders.