We present a discovery of a giant stellar halo in NGC 6822, a dwarf irregular galaxy in the Local Group. This halo is mostly made of old red giants, showing striking features: 1) it is several times larger than the main body of the galaxy seen in the optical images, and 2) it is elongated in the direction almost perpendicular to the HI disk of NGC 6822. The structure of this stellar halo looks ...

An expression for the radiation force from a cw-laser on a fluidfluid interface is derived that is able to model the giant deformations observed in modern experiments when the fluid system is close to the critical point implying that the surface tension is very small. The core of our argument is that the system is modelled as a step-index optical fiber. Then, observing that the dominant HE11 mo...

Abstract The axiom system ACP of [10] was extended to discrete time in [6]. Here, we proceed to define the silent step in this theory in branching bisimulation semantics [7, 15] rather than weak bisimulation semantics [11, 20]. The version using relative timing is discussed extensively, versions using absolute and parametric timing are presented in brief. A term model and a graph model are pres...

We propose a new method for constructing Turing ideals satisfying principles of reverse mathematics below the Chain-Antichain Principle (CAC). Using this method, we are able to prove several new separations in the presence of Weak König’s Lemma (WKL), including showing that CAC ` WKL does not imply the thin set theorem for pairs, and that the principle “the product of well-quasi-orders is a wel...

The dynamic assembly of microtubules is a key factor in many of their functions in the cell and recent experiments give new insight into this process at the molecular level.

In this work we demonstrate two potential dangers of multiple-time-step techniques for numerical integration of differential equations. This idea of using different time steps for different interactions was proposed in 1978 for molecular dynamics but undoubtedly has other useful applications. The use of multiple time stepping with the popular Verlet method was proposed in a 1991 paper. However,...

This paper presents a method for creating a robust system for modeling physical interactions between objects. The system avoids problems such as objects escaping or passing through each other due to undetected collisions caused by excessive velocities or insufficient time resolution.

Peripheral arterial disease (PAD) is a common disorder and a major cause of morbidity and mortality.1 The most severely affected patients, with rest pain, ulcerations, or gangrene, are given a diagnosis of critical limb ischemia (CLI). These patients have a particularly poor prognosis, with high rates of limb amputation and mortality. Despite improvements in medical therapy for atherosclerosis ...

Analog simulators typically use a dynamic, adaptive time step control strategy in order to minimize the calculations performed during inactive portions of a system’s operation, while maintaining adequate time resolution during active portions. Without this dynamic control of time steps, one could generate too few time steps to accurately render fast-edged events, or spend a large percentage of ...

We present a novel approach for terahertz time-domain spectroscopy of magneto-optic phenomena. The setup used in this work combines a tabletop pulsed magnet and a standard terahertz time-domain spectroscopy system. The approach is based on repetitive operation of the pulsed magnet and step-wise increment of the delay time of the time-domain spectroscopy system. The method is demonstrated by plo...