Overconfidence in Photometric Redshift Estimation

We describe a new test of photometric redshift performance given a spectroscopic redshift sample. This test complements the traditional comparison of redshift {\it differences} by testing whether the probability density functions $p(z)$ have the correct {\it width}. We test two photometric redshift codes, BPZ and EAZY, on each of two data sets and find that BPZ is consistently overconfident (the $p(z)$ are too narrow) while EAZY produces approximately the correct level of confidence. We show that this is because EAZY models the uncertainty in its spectral energy distribution templates, and that post-hoc smoothing of the BPZ $p(z)$ provides a reasonable substitute for detailed modeling of template uncertainties. Either remedy still leaves a small surplus of galaxies with spectroscopic redshift very far from the peaks. Thus, better modeling of low-probability tails will be needed for high-precision work such as dark energy constraints with the Large Synoptic Survey Telescope and other large surveys.Comment: accepted to MNRA

Analysis of other transaction agreements to acquire innovative renewable energy solutions for the Department of the Navy

MBA Professional ReportThe purpose of this project is to use a case-study approach to analyze the effectiveness and efficiency of other transaction (OT) agreements and the OT Consortium Model to acquire innovative renewable energy solutions. OTs are typically used for prototypes; however, the fiscal year (FY) 2016 National Defense Authorization Act (NDAA) expands the use of OT authority per statute 10 U.S.C. § 2371. Our research includes interviews with Defense Innovative Unit–Experimental personnel to highlight their experience with innovative businesses previously reluctant to pursue federal contracts. Additionally, our research leverages best practices from the Army Contracting Command–New Jersey, as well as industry partners, such as the Consortium for Energy, Environment, and Demilitarization and the National Security Technology Accelerator consortium, to compile recommendations for the Department of the Navy's acquisition strategy for renewable energy. The results of this case study include recommendations on the best use of OT agreements to drive innovation into the procurement of renewable energy solutions in accordance with Better Buying Power 3.0 initiatives.http://archive.org/details/analysisofothert1094551627Lieutenant Commander, United States NavyLieutenant Commander, United States NavyLieutenant, United States NavyApproved for public release; distribution is unlimited

A strategy and support at school level

The need for strategies and supports at school level to facilitate implementation of curriculum innovation and change has long been recognised. Teachers need the opportunity to develop a clear understanding of the innovation, to be given time to become convinced of its value and of its potential to make a difference in terms of pupil learning. This paper outlines how teacher-researchers working within the Irish context carried out research into their own practice. In aiming to understand and inform their practice as teachers, action research was the preferred approach to enquiry in both schools. Bernie Tobin is an Assistant Principal in a primary school. Her research focuses on the implementation of the approach to writing outlined in the English Language Curriculum. Mairéad Ryan, at the time of the study was a classroom teacher but is now a school Principal. She investigates the use of games in a junior primary school. Margaret Farren is a teacher educator at Dublin City University. She explains the methods used to ensure the validity and rigour of the case studies. These include: Whitehead’s (1989, 2004) action research cycles; Habermas’ (1976) social validation and Winter’s (1989) criteria of rigour

Alterations to the Gastrointestinal Microbiome Associated with Methamphetamine Use among Young Men who have Sex with Men.

Methamphetamine (MA) use is a major public health problem in the United States, especially among people living with HIV (PLWH). Many MA-induced neurotoxic effects are mediated by inflammation and gut microbiota may play a role in this process, yet the effects of MA on the microbiome have not been adequately explored. Therefore, we performed 16S rRNA gene sequencing on rectal swab samples from 381 men who have sex with men, 48% of whom were PLWH and 41% of whom used MA. We compared microbiome composition between MA users and non-users while testing for potential interactions with HIV and controlling for numerous confounders using inverse probability of treatment weighting. We found that MA use explained significant variation in overall composition (R2 = 0.005, p = 0.008) and was associated with elevated Finegoldia, Parvimonas, Peptoniphilus, and Porphyromonas and reduced Butyricicoccus and Faecalibacterium, among others. Genera including Actinomyces and Streptobacillus interacted with HIV status, such that they were increased in HIV+ MA users. Finegoldia and Peptoniphilus increased with increasing frequency of MA use, among others. In summary, MA use was associated with a microbial imbalance favoring pro-inflammatory bacteria, including some with neuroactive potential and others that have previously been associated with poor HIV outcomes

Compiling Tree Transforms to Operate on Packed Representations

When written idiomatically in most programming languages, programs that traverse and construct trees operate over pointer-based data structures, using one heap object per-leaf and per-node. This representation is efficient for random access and shape-changing modifications, but for traversals, such as compiler passes, that process most or all of a tree in bulk, it can be inefficient. In this work we instead compile tree traversals to operate on pointer-free pre-order serializations of trees. On modern architectures such programs often run significantly faster than their pointer-based counterparts, and additionally are directly suited to storage and transmission without requiring marshaling. We present a prototype compiler, Gibbon, that compiles a small first-order, purely functional language sufficient for tree traversals. The compiler transforms this language into intermediate representation with explicit pointers into input and output buffers for packed data. The key compiler technologies include an effect system for capturing traversal behavior, combined with an algorithm to insert destination cursors. We evaluate our compiler on tree transformations over a real-world dataset of source-code syntax trees. For traversals touching the whole tree, such as maps and folds, packed data allows speedups of over 2x compared to a highly-optimized pointer-based baseline

Photometric variability of Sun-like stars in the old open cluster M67

Few physical processes can affect the earth\u27s climate on a global scale. The variability of the Sun is one such process. The Sun is known to vary by about 0.1% due to Sunspots and other surface activity. We do not yet know whether the Sun\u27s variability is normal. Using the well-known properties of the old open cluster M67, we look for variations in Sun-like stars.;In this thesis, we present the results of observation, calibration, correction and analysis of stars in M67. We focus on Sun-like stars and binary systems. We also determine the limits of observation using a small research-grade telescope.;We find several known variable stars with comparable amplitudes of variability. Our precision is as high as 10 millimagnitudes, ranging 10-20 for Sun-like stars. Variability is detected as low as 20 millimagnitudes in amplitude. Our current precision, however, fails to detect solar-like variations

Cancellous bone and theropod dinosaur locomotion. Part I—an examination of cancellous bone architecture in the hindlimb bones of theropods

This paper is the first of a three-part series that investigates the architecture of cancellous (‘spongy’) bone in the main hindlimb bones of theropod dinosaurs, and uses cancellous bone architectural patterns to infer locomotor biomechanics in extinct non-avian species. Cancellous bone is widely known to be highly sensitive to its mechanical environment, and has previously been used to infer locomotor biomechanics in extinct tetrapod vertebrates, especially primates. Despite great promise, cancellous bone architecture has remained little utilized for investigating locomotion in many other extinct vertebrate groups, such as dinosaurs. Documentation and quantification of architectural patterns across a whole bone, and across multiple bones, can provide much information on cancellous bone architectural patterns and variation across species. Additionally, this also lends itself to analysis of the musculoskeletal biomechanical factors involved in a direct, mechanistic fashion. On this premise, computed tomographic and image analysis techniques were used to describe and analyse the three-dimensional architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs for the first time. A comprehensive survey across many extant and extinct species is produced, identifying several patterns of similarity and contrast between groups. For instance, more stemward non-avian theropods (e.g. ceratosaurs and tyrannosaurids) exhibit cancellous bone architectures more comparable to that present in humans, whereas species more closely related to birds (e.g. paravians) exhibit architectural patterns bearing greater similarity to those of extant birds. Many of the observed patterns may be linked to particular aspects of locomotor biomechanics, such as the degree of hip or knee flexion during stance and gait. A further important observation is the abundance of markedly oblique trabeculae in the diaphyses of the femur and tibia of birds, which in large species produces spiralling patterns along the endosteal surface. Not only do these observations provide new insight into theropod anatomy and behaviour, they also provide the foundation for mechanistic testing of locomotor hypotheses via musculoskeletal biomechanical modelling

The Secret to Successful User Communities: An Analysis of Computer Associates’ User Groups

This paper provides the first large scale study that examines the impact of both individual- and group-specific factors on the benefits users obtain from their user communities. By empirically analysing 924 survey responses from individuals in 161 Computer Associates' user groups, this paper aims to identify the determinants of successful user communities. To measure success, the amount of time individual members save through having access to their user networks is used. As firms can significantly profit from successful user communities, this study proposes four key implications of the empirical results for the management of user communities

EFFECTS OF THE BENCH SHIRT ON SELECTED BENCH PRESS MECHANICS

Power lifting is an individual sport enjoyed by participants in over 78 countries. Participants compete in three separate lifts and the Iifter with the highest total is the winner. However. this study is concerned purely with the bench press. The "bench shirt" is a cotton/polyester. single-ply form-fitting shirt that is used by lifters to enhance performance during the bench press. Power lifters use these shirts in an attempt to Increase the load lifted in competition. However, it Is possible that these shirts, due to their extreme form fit to the body, could alter the natural motion of the bench press exercise. Researchers have investigated the mechanics of the bench press. and identified proper technique (Judge, 1998; Madsen & McLaughlin, 1984). Proper mechanics dictate that for any experienced lifter there exists a consistent order of bar velocity (increasing velocity off of the chest, decreasing velocity throug the "sticking region," increasing velocity after the sticking region. final decreasing velocity at the finish) (Madsen & McLaughlin, 1984). The bar path should be as indicated in Figure 1. However, no published studies have demonstrated the effect the bench shirt on bench press lifting technique. Therefore. the purpose of this study was to determine the changes in bar path and bar velocity when performing the bench press shirted versus raw (no bench shirt)

EFFECTS OF THE BENCH SHIRT ON SAGITTAL BAR PATH

Powerlifting, like many sports, uses performance-enhancing equipment. The purpose of this study was to explore whether wearing a bench shirt would alter the natural mechanics of the bench press. Participants (n=5) completed two bench press tests; the first was raw (no shirt), while the second utilized the bench shirt. Vertical bar path ranges were significantly smaller in the shirted condition compared to the raw condition. Significant differences were found between the optimal and observed values while benching during the raw condition, but no significant differences were found in the shirted condition. Assuming a straight line bar path is optimal, findings suggest the bench shirt may provide a more efficient bar path, improving load capability and decreasing the forces that act on the shoulder and thus the likelihood of injury