On the dark matter profile in Sculptor: Breaking the β\beta degeneracy with Virial shape parameters

We present a new method for studying tracers in gravitational systems where higher moments of the line-of-sight velocity distribution are introduced via Virial equations rather than the Jeans equations. Unlike the fourth order Jeans equations, the fourth order Virial equations can simply be added to the standard second order Jeans equation without introducing a new anisotropy parameter $\beta^{\prime}$. We introduce two new global shape parameters $\zeta_A$ and $\zeta_B$ which replace the kurtosis as a more statistically robust measure of the shape of the line of sight velocity distribution. We show that in the case of stars in dwarf spheroidal galaxies these new parameters can significantly reduce the range of density profiles that are otherwise consistent with the observed stellar kinematics (a problem sometimes known as the $\beta$ degeneracy). Specifically, we find that $\zeta_A$ focuses tightly on a subset of solutions where cusped density profiles are degenerate with more concentrated cored dark matter halos. If the number density of stars $\nu(r)$ is fixed, then introducing $\zeta_B$ can further reduce the space of solutions by constraining the outer slope of the dark matter density profile. Assuming a Plummer profile for $\nu(r)$ we recover the surprising result that the dark matter in Sculptor may be cuspy after all, in contrast to the conclusions of other approaches.Comment: 19 pages, 15 figures. Matches version accepted in MNRAS. Minor additions to text. Conclusions unchange

Fundamentals of Teaching Vocal Music Performance

This study outlines the significance and sole purpose of developing fundamental techniques of student vocal music performances, using professional constructive evaluation that will improve their overall performance experience. One of the most practical ways to support vocalists is to provide a constructive evaluation of their performances. The implementation of constructive evaluation is to reflect upon what is being done well, discover areas of improvement or refinement, plan and facilitate important lessons, and apply the lessons to future performances. As a music teacher who is actively overseeing the development of students as performing or creating musicians, including constructive evaluation is a standard expectation. Methodical, thorough self-evaluations and peer evaluations are enormously valuable practices for young vocalists. In rehearsals, workshops, and other group situations, constructive evaluation from peers will also be very useful, but only if group members understand how to offer the evaluation. To give a high-quality performance, vocalists must get in the habit of evaluating themselves as often as possible. An evaluation that is offered sloppily or in the wrong spirit can be damaging to the student’s vocal development. This study will also include a plethora of techniques for creating positive, useful evaluations, including: Analyzing the Performance, Self & Peer-Evaluations, Glows and Grows, Use of Fundamental Elements of Music, Solutions Oriented Feedback, and helping students develop coping skills for performance anxiety. The principles and ideas offered for private instruction can also be quite valuable to choir and ensemble directors, praise and worship teams, group lessons, and music theatre singers

Crystallization of a Mos1 transposase-inverted-repeat DNA complex: biochemical and preliminary crystallographic analyses

A complex formed between Mos1 transposase and its inverted-repeat DNA has been crystallized. The crystals diffract to 3.25 Å resolution and exhibit monoclinic (P2(1)) symmetry, with unit-cell parameters a = 120.8, b = 85.1, c = 131.6 Å, β = 99.3°. The X-ray diffraction data display noncrystallographic twofold symmetry and characteristic dsDNA diffraction at ∼3.3 Å. Biochemical analyses confirmed the presence of DNA and full-length protein in the crystals. The relationship between the axis of noncrystallographic symmetry, the unit-cell axes and the DNA diffraction pattern are discussed. The data are consistent with the previously proposed model of the paired-ends complex containing a dimer of the transposase

Separating a wavefield by propagation direction

Determining the propagation direction of waves in a wavefield is important in several seismic imaging techniques and applications. This can be achieved using the Poynting vector method, but it performs poorly when waves overlap, returning incorrect wave amplitude and direction. An alternative, the local slowness method, is capable of separating overlapping waves, but suffers from low angular resolution. We describe modifications of these two approaches that improve the ability to extract the wave amplitude propagating in different directions. The primary modification is the addition of a wavefront orientation separation step. We evaluate the original and modified methods' ability to separate six overlapping waves in a constant velocity model and find that the modifications significantly improve the results

Biofilm-forming capability of highly virulent, multidrug-resistant Candida auris

The emerging multidrug-resistant yeast pathogen Candida auris has attracted considerable attention as a source of healthcare–associated infections. We report that this highly virulent yeast has the capacity to form antifungal resistant biofilms sensitive to the disinfectant chlorhexidine in vitro

Reverse Time Migration in the presence of known sharp interfaces

We propose using the forward propagated source wave to create synthetic receiver data on the surfaces of the computational domain where real receiver data is not available as a means of exploiting known information about reflector locations in Reverse Time Migration. The inclusion of synthetic boundary data can make true amplitude imaging possible, and reduce the artifacts associated with the inclusion of multiples. Here, we describe the new method, present synthetic examples, and propose an appropriate imaging condition

A multi-pass one way method to include turning waves and multiples

Conventional one way migration methods exclude turning waves and multiples. We propose an algorithm that uses multiple passes to extend the one way method to efficiently include these wavepaths. A comparison of the images produced by the regular one way algorithm, RTM, and the new method, shows that this new method can significantly improve the image in regions of interest, and in certain situations may even provide more useful information than RTM. The runtime is demonstrated to be in between that of regular one way and RTM, while the physical memory required is considerably lower than that of RTM