Genetic sampling for estimating density of common species.

Understanding population dynamics requires reliable estimates of population density, yet this basic information is often surprisingly difficult to obtain. With rare or difficult-to-capture species, genetic surveys from noninvasive collection of hair or scat has proved cost-efficient for estimating densities. Here, we explored whether noninvasive genetic sampling (NGS) also offers promise for sampling a relatively common species, the snowshoe hare (Lepus americanus Erxleben, 1777), in comparison with traditional live trapping. We optimized a protocol for single-session NGS sampling of hares. We compared spatial capture-recapture population estimates from live trapping to estimates derived from NGS, and assessed NGS costs. NGS provided population estimates similar to those derived from live trapping, but a higher density of sampling plots was required for NGS. The optimal NGS protocol for our study entailed deploying 160 sampling plots for 4 days and genotyping one pellet per plot. NGS laboratory costs ranged from approximately $670 to$3000 USD per field site. While live trapping does not incur laboratory costs, its field costs can be considerably higher than for NGS, especially when study sites are difficult to access. We conclude that NGS can work for common species, but that it will require field and laboratory pilot testing to develop cost-effective sampling protocols

Reflections on Two Years of Manuscript Reviewing

College & Research Libraries receives a large number of manuscripts each year that have kept the two of us busy, as editorial assistants, with many of the initial reviews of submission for the journal during the last two years. In 2011 alone C&RL received 134 submissions, of which only 46 were finally selected for publication. This acceptance rate demonstrates the rigor of our review process, but it is coupled with our desire to help prospective authors succeed. There are insights we can offer from our editorial experience that help explain why manuscripts are rejected as well as advice on how to overcome typical problems and barriers we have observed. We would like to frame our insights around the editorial questions we are asked to answer in our initial evaluation of manuscripts

More than skin deep

Regular readers of the Australian Journal of Physiotherapy will have noticed a number of cosmetic changes made to the journal since it received its last major facelift at the beginning of 1999. Most of these changes have been designed to make the journal a more attractive “read”. But the real changes go more than skin deep. The Editorial Board has been implementing structural changes to the way that the journal is produced and disseminated, with the aim of ensuring that scientifically credible and clinically important information is delivered to as wide an audience as possible

Real-Time Monitoring of Aluminum Oxidation Through Wide Band Gap MgF2 Layers for Protection of Space Mirrors

Because of its extraordinary and broad reflectivity, aluminum is the only logical candidate for advanced space mirrors that operate deep into the UV. However, aluminum oxidizes rapidly in the air, and even a small amount of oxide (as little as a nanometer) can have a noticeable, detrimental impact on its reflectivity at short wavelengths. Thin films of wide band gap materials like MgF2 have previously been used to protect aluminum surfaces. Here we report the first real-time, spectroscopic ellipsometry (SE) study of aluminum oxidation as a function of MgF2 over layer thickness, which ranged from 0 – 6 nm. SE data analysis was performed vis-à-vis a multilayer optical model that included a thick silicon nitride layer. The optical constants for evaporated aluminum were initially determined using a multi-sample analysis (MSA) of SE data from MgF2 protected and bare Al surfaces. Two models were then considered for analyzing the real-time data obtained from Al/MgF2 stacks. The first used the optical constants of aluminum obtained in the MSA with two adjustable parameters: the thicknesses of the aluminum and aluminum oxide layers. The thicknesses obtained from this model showed the expected trends (increasing Al2O3 layer thickness and decreasing Al layer thickness with time), but some of the Al2O3 thicknesses were unphysical (negative). Because the optical constants of very thin metals films depend strongly on their structures and deposition conditions, a second, more advanced model was employed that fit the optical constants for Al, and also the Al and Al2O3 thicknesses, for each data set. In particular, the Al and Al2O3 thicknesses and optical constants of Al were determined in an MSA for each of 50 evenly spaced analyses in each four-hour dynamic run performed. The resulting optical constants for Al were then fixed for that sample and the thicknesses of the Al and Al2O3 layers were determined. While the first and second models yielded similar Al and Al2O3 thickness vs. time trends, the film thicknesses obtained in this manner were more physically reasonable. Thicker MgF2 layers slow the oxidation rate of aluminum. The results from this work should prove useful in protecting space mirrors prior to launch

Supermassive Black Hole Feedback

Understanding the processes that drive galaxy formation and shape the observed properties of galaxies is one of the most interesting and challenging frontier problems of modern astrophysics. We now know that the evolution of galaxies is critically shaped by the energy injection from accreting supermassive black holes (SMBHs). However, it is unclear how exactly the physics of this feedback process affects galaxy formation and evolution. In particular, a major challenge is unraveling how the energy released near the SMBHs is distributed over nine orders of magnitude in distance throughout galaxies and their immediate environments. The best place to study the impact of SMBH feedback is in the hot atmospheres of massive galaxies, groups, and galaxy clusters, which host the most massive black holes in the Universe, and where we can directly image the impact of black holes on their surroundings. We identify critical questions and potential measurements that will likely transform our understanding of the physics of SMBH feedback and how it shapes galaxies, through detailed measurements of (i) the thermodynamic and velocity fluctuations in the intracluster medium (ICM) as well as (ii) the composition of the bubbles inflated by SMBHs in the centers of galaxy clusters, and their influence on the cluster gas and galaxy growth, using the next generation of high spectral and spatial resolution X-ray and microwave telescopes.Comment: 10 pages, submitted to the Astro2020 decada

Summary of NDE of Additive Manufacturing Efforts in NASA

(1) General Rationale for Additive Manufacturing (AM): (a) Operate under a 'design-to-constraint' paradigm, make parts too complicated to fabricate otherwise, (b) Reduce weight by 20 percent with monolithic parts, (c) Reduce waste (green manufacturing), (e) Eliminate reliance on Original Equipment Manufacturers for critical spares, and (f) Extend life of in-service parts by innovative repair methods; (2) NASA OSMA NDE of AM State-of-the-Discipline Report; (3) Overview of NASA AM Efforts at Various Centers: (a) Analytical Tools, (b) Ground-Based Fabrication (c) Space-Based Fabrication; and (d) Center Activity Summaries; (4) Overview of NASA NDE data to date on AM parts; and (5) Gap Analysis/Recommendations for NDE of AM

The nuclear structural protein NuMA is a negative regulator of 53BP1 in DNA double-strand break repair

P53-binding protein 1 (53BP1) mediates DNA repair pathway choice and promotes checkpoint activation. Chromatin marks induced by DNA double-strand breaks and recognized by 53BP1 enable focal accumulation of this multifunctional repair factor at damaged chromatin. Here, we unveil an additional level of regulation of 53BP1 outside repair foci. 53BP1 movements are constrained throughout the nucleoplasm and increase in response to DNA damage. 53BP1 interacts with the structural protein NuMA, which controls 53BP1 diffusion. This interaction, and colocalization between the two proteins in vitro and in breast tissues, is reduced after DNA damage. In cell lines and breast carcinoma NuMA prevents 53BP1 accumulation at DNA breaks, and high NuMA expression predicts better patient outcomes. Manipulating NuMA expression alters PARP inhibitor sensitivity of BRCA1-null cells, end-joining activity, and immunoglobulin class switching that rely on 53BP1. We propose a mechanism involving the sequestration of 53BP1 by NuMA in the absence of DNA damage. Such a mechanism may have evolved to disable repair functions and may be a decisive factor for tumor responses to genotoxic treatments