Volume phase holographic gratings for the Subaru Prime Focus Spectrograph: performance measurements of the prototype grating set

The Prime Focus Spectrograph (PFS) is a major instrument under development for the 8.2 m Subaru telescope. Four identical spectrograph modules are located in a room above one Nasmyth focus. A 55~m fiber optic cable feeds light to the spectrographs from a robotic positioner at the prime focus, behind the wide-field corrector developed for Hyper Suprime-Cam. The positioner contains 2400 fibers and covers a 1.3~degree hexagonal field of view. The spectrograph optical design consists of a Schmidt collimator, two dichroic beamsplitters to split the light into three channels, and for each channel a volume phase holographic (VPH) grating and a dual-corrector, modified Schmidt reimaging camera. This design provides a 275~mm collimated beam diameter, wide simultaneous wavelength coverage from 380~nm to 1.26~\textmu m, and good imaging performance at the fast f/1.05 focal ratio required from the cameras to avoid oversampling the fibers. The three channels are designated as the blue, red, and near-infrared (NIR), and cover the bandpasses 380--650~nm (blue), 630--970~nm (red), and 0.94--1.26~\textmu m (NIR). A mosaic of two Hamamatsu 2k$\times$4k, 15~\textmu m pixel CCDs records the spectra in the blue and red channels, while the NIR channel employs a 4k$\times$4k, substrate-removed HAWAII-4RG array from Teledyne, with 15~\textmu m pixels and a 1.7~\textmu m wavelength cutoff. VPH gratings were an obvious choice for PFS and a set of three prototype VPH gratings (one each of the blue, red, and NIR designs) was ordered and has been recently delivered. In this paper we present the design and specifications for the PFS gratings, the plan and setups used for testing both the prototype and final gratings, and results from recent optical testing of the prototype grating set.Comment: 18 pages, 20 figures SPIE Astronomical Telescopes and Instrumentation 2014, Montrea

Key pedagogic thinkers: Jean Baudrillard

Jean Baudrillard was born in Reims, France, in 1929, and completed his undergraduate work at the Sorbonne, taking a degree in German. Upon graduation, he taught high school. In the early 1960s, he began graduate studies at the University of Paris, Nanterre, earning his doctorate in sociology in 1966. Baudrillard published 30 books in which he examined various facets of modern society: gender, race, consumerism, politics, the media, and so forth. His focus was semiological—how objects and signs reflect the current human condition. Although Baudrillard did not write about education, his work is nevertheless relevant if we recognize that our educational system is a reflection of society. A Baudrillardian perspective raises the following question: What effect has consumerism had on education? To address this question, we offer some background information related to Baudrillard’s philosophical inquiries. This is followed by our brief analysis of how Baudrillard’s work may provide some potential answers to the above question and of how it can help us interpret the changes that have occurred in education during the modern period. We give special emphasis to The Consumer Society and Simulacra and Simulation

Corrigenda to and validation of Ozophora woodruffi Slater 2005 (Hemiptera: Lygaeidae)

Important missing specimen data are provided for the original description of Ozophora woodruffi Slater (2005: 245) (Hemiptera: Lygaeidae), along with additional comparative relationships. Because of the missing type information, according to ICZN rules (1999), the species became a nomen nudum. This paper now serves to validate the name, and authorship becomes Slater (2012)

Prediction of aeroelastic response of a model X-wing rotor

The rotorcraft dynamics analysis was used to predict the aeroelastic responses of a representative X-wing model with a 10 ft diameter rotor. The aeroelastic methodology used and the tests and assumptions involved are reviewed. Results are reported on the findings concerning control power and higher harmonic control in hover, transition flight, vibratory loads at forward speed, and responses in conversion. It is concluded that the analysis can give satisfactory predictions of X-wing behavior

The Impact of Driver Cell Phone Use on Accidents

Cell phone use is increasing worldwide, leading to a concern that cell phone use while driving increases accidents. We develop a new approach for estimating the relationship between cell phone use while driving and accidents, based on new survey data. We test for selection effects, such as whether drivers who use cell phones are inherently less safe drivers, even when not on the phone. The paper has two key findings. First, the impact of cell phone use on accidents varies across the population. This result implies that previous estimates of the impact of cell phone use on risk for the population, based on accident-only samples, may therefore be overstated by 36%. Second, once we correct for endogeneity, there is no significant effect of hands-free or hand-held cell phone use on accidents.cellular telephones and driving, safety regulation, selection effects

PSAgraphics: An R Package to Support Propensity Score Analysis

Propensity score analysis is a technique for adjusting for selection bias in observational data. Estimated propensity scores (probability of treatment given observed covariates) are used for stratification of observations. Within strata covariates should be more balanced between the two treatments than without the stratification. PSAgraphics is an R package that provides flexible graphical tools to assess within strata balance between treatment groups, as well as how covariate distributions differ across strata. Additional graphical tools facilitate estimation of treatment effects having adjusted for covariate differences. Several new and conventional numerical measures of balance are also provided.

The Impact of Driver Cell Phone Use on Accidents

Cell phone use is increasing worldwide, leading to a concern that cell phone use while driving increases accidents. Several countries, three states and Washington, D.C. have banned the use of hand-held cell phones while driving. In this paper, we develop a new approach for estimating the relationship between cell phone use while driving and accidents. Our approach is the first to allow for the direct estimation of the impact of a cell phone ban while driving. It is based on new survey data from over 7,000 individuals. This paper differs from previous research in two significant ways: first, we use a larger sample of individual-level data; and second, we test for selection effects, such as whether drivers who use cell phones are inherently less safe drivers, even when not on the phone. The paper has two key findings. First, the impact of cell phone use on accidents varies across the population. This result implies that previous estimates of the impact of cell phone use on risk for the population, based on accident-only samples, may be overstated by about one-third. Second, once we correct for endogeneity, there is no significant effect of hands-free or hand-held cell phone use on accidents.

OPPORTUNITIES FOR MARKETING FRESH PRODUCE TO THE INSTITUTIONAL SECTOR OF THE FOOD SERVICE INDUSTRY

The authors investigated the possible barriers to marketing fresh fruits and vegetables to the institutional sector of the food service industry.Agribusiness, Marketing,

Markets, Institutions and Family Size in Rural Philippine Households

This article has been presented at the Workshop on Methods for Agricultural Policy Analysis held at the UP Los Baños on August 13-14, 1985. It develops a framework for explaining the nonmarket to market transitions. In particular, this framework is used to generate specific hypotheses confronted with evidence from the Philippine rural households.health sector, agriculture sector, fertility, rural sector, econometric modeling