Development and evaluation of infrared sensitive image sensors for space astronomy

The experimental development and evaluation of infrared vidicons for use in solving high precision high flux broadband astronomical problems are discussed. Data cover the EOS, silicon, and doped germanium vidicons. Results are graphed and problems encountered using the vidicons in electrical cameras are reported

Velocity dispersions in galaxies: 1: The SO galaxy NGC 7332

A Coude spectrum of the SO galaxy NGC 7332 with 0.9 A resolution from 4186 to 4364 A was obtained with the SEC vidicon television camera and the Hale telescope. Comparisons with spectra of G and K giant stars, numerically broadened for various Maxwellian velocity distributions, give a dispersion velocity in the line of sight of 160 + or - 20 km/sec with the best fit at G8III. The dispersion appears to be constant within + or - 35 km/sec out to 1.4 kpc (H = 100 km/sec/mpc). After correction for projection, the rotation curve has a slope of 0.16 km/sec/pc at the center and a velocity of 130 km/sec at 1.4 kpc where it is still increasing. For an estimated effective radius of 3.5 kpc enclosing half the light, the virial theorem gives a mass of 1.4 x 10 to the 11th power solar masses if the mass-to-light ratio is constant throughout the galaxy. The photographic luminosity is 8.3 x 10 to the 9th power solar luminosities so that the M/L ratio is 17

‘Maturing Out’ as dilemmatic: Transitions towards relatively light drinking practices among UK University students

Objectives University students in the UK engage in relatively high alcohol consumption levels, yet young adults, including students, now drink less than previously and abstain more. Against this cultural backdrop, our objective was to further understanding of ‘maturing out’ of excessive drinking practices among students by focusing on drinking transitions that had taken place during university years. Design A qualitative interview study. Methods Semi‐structured interviews were conducted with ten 18‐ to 27‐year‐old UK undergraduate university students who self‐identified as light or non‐drinkers. Interviews were audio‐recorded, and anonymized interview transcripts were subjected to an experience‐focused application of thematic analysis. Results Participants reported dilemmas involved in transitions from relatively high to low levels of alcohol consumption. One dilemma was characterized by managing to drink less (or nothing) without cutting off social options with university friends/peers. A second dilemma concerned not wishing to fully abandon the pleasures and increased social confidence that alcohol consumption could afford. Results also demonstrated that self‐reported drinking could contradict participants’ self‐defined ‘light drinker’ status. Conclusions This study reinforces the view that ‘maturing out’ involves more than simply having gained new responsibilities during young adulthood. Recognition of these dilemmatic features of drinking transitions could be drawn on in novel campus‐based interventions. Such interventions may help strengthen realistic and sustainable moderate drinking by guiding students to anticipate potential difficulties involved in planned reductions in personal drinking but may also help foster students’ ability to view drinking choices as in transition rather than as permanent and enduring

Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra

We present a technique to extract radial velocity measurements from echelle spectrograph observations of rapidly rotating stars ($V\sin{i} \gtrsim 50$ km s$^{-1}$). This type of measurement is difficult because the line widths of such stars are often comparable to the width of a single echelle order. To compensate for the scarcity of lines and Doppler information content, we have developed a process that forward-models the observations, fitting the radial velocity shift of the star for all echelle orders simultaneously with the echelle blaze function. We use our technique to extract radial velocity measurements from a sample of rapidly rotating A- and B-type stars used as calibrator stars observed by the California Planet Survey observations. We measure absolute radial velocities with a precision ranging from 0.5-2.0 km s$^{-1}$ per epoch for more than 100 A- and B-type stars. In our sample of 10 well-sampled stars with radial velocity scatter in excess of their measurement uncertainties, three of these are single-lined binaries with long observational baselines. From this subsample, we present detections of two previously unknown spectroscopic binaries and one known astrometric system. Our technique will be useful in measuring or placing upper limits on the masses of sub-stellar companions discovered by wide-field transit surveys, and conducting future spectroscopic binarity surveys and Galactic space-motion studies of massive and/or young, rapidly-rotating stars.Comment: Accepted to ApJ

Helium energy levels including mα6m \alpha^6 corrections

The $m \alpha^6$ correction to energy is expressed in terms of an effective Hamiltonian $H^{(6)}$ for an arbitrary state of helium. Numerical calculations are performed for $n=2$ levels, and the previous result for the $2^3P$ centroid is corrected. While the resulting theoretical predictions for the ionization energy are in moderate agreement with experimental values for $2^3S_1$, $2^3P$, and $2^1S_0$ states, they are in significant disagreement for the singlet state $2^1P_1$.Comment: 11 pages, with erratum submitted to Phys. Rev. A (2007

Choosing the lesser of two evils, the better of two goods: Specifying the roles of ventromedial prefrontal cortex and dorsal anterior cingulate in object choice

The ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortices (ACd) are considered important for reward-based decision making. However, work distinguishing their individual functional contributions has only begun. One aspect of decision making that has received little attention is that making the right choice often translates to making the better choice. Thus, response choice often occurs in situations where both options are desirable (e.g., choosing between mousse au chocolat or crème caramel cheesecake from a menu) or, alternatively, in situations where both options are undesirable. Moreover, response choice is easier when the reinforcements associated with the objects are far apart, rather than close together, in value. We used functional magnetic resonance imaging to delineate the functional roles of the vmPFC and ACd by investigating these two aspects of decision making: (1) decision form (i.e., choosing between two objects to gain the greater reward or the lesser punishment), and (2) between-object reinforcement distance (i.e., the difference in reinforcements associated with the two objects). Blood oxygen level-dependent (BOLD) responses within the ACd and vmPFC were both related to decision form but differentially. Whereas ACd showed greater responses when deciding between objects to gain the lesser punishment, vmPFC showed greater responses when deciding between objects to gain the greater reward. Moreover, vmPFC was sensitive to reinforcement expectations associated with both the chosen and the forgone choice. In contrast, BOLD responses within ACd, but not vmPFC, related to between-object reinforcement distance, increasing as the distance between the reinforcements of the two objects decreased. These data are interpreted with reference to models of ACd and vmPFC functioning

Epidural Analgesia Decreases Narcotic Requirements in Low Level Spina Bifida Patients Undergoing Urologic Laparotomy for Neurogenic Bladder and Bowel

Purpose Concern of anatomical anomalies and worsening neurologic symptoms has prevented widespread use of epidural catheters in patients with low level spina bifida (LLSB). We hypothesize that thoracic epidural placement in the T9-T10 interspace is safe and decreases narcotic requirements in LLSB patients following major open lower urinary tract reconstruction (LUTR). Materials and Methods We reviewed consecutive LLSB patients who had LUTR and epidurals for post-operative pain control. Controls were LLSB patients who received single shot transversus abdominis plane (TAP) blocks with similar procedures. Complications from epidural placement, including changes in motor and sensory status were recorded. Opioid consumption was calculated utilizing equivalent IV morphine doses. Mean and maximum pain scores on post-operative day (POD) 0-3 were calculated. Results 10 LLSB patients who had lower urinary tract reconstruction and epidurals were matched to 10 LLSB patients who had lower urinary tract reconstruction and transverse abdominis plane blocks. Groups were demographically similar. All had full abdominal sensation and functional levels at or below L3. No epidural complications or changes in neurological status were noted. The epidural group had decreased opioid consumption on POD 0-3 (0.75 mg/kg vs. 1.29 mg/kg, p=0.04). Pain scores were similar or improved in the epidural group. Conclusions Thoracic epidural analgesia appears to be a safe and effective opioid sparing option to assist with post-operative pain management following lower urinary tract reconstruction in LLSB patients

Interactions Between the Effects of Nitrogen, and Phosphorus, Potassium and Sulphur on Grass Production

The interactions between rates of nitrogen (N) and rates of phosphorus (P), potassium (K) or sulphur (S) on yield of ryegrass dominant swards were measured with no return of mown clippings in Southland, New Zealand. In the second year of the trial, the yield response to 176 kg N ha-1 compared with no N increased only slightly with increasing soil Olsen P from 8 to 91 µg g-1 soil. At 352 and 704 kg N ha-1 there was a large increase in the yield response (from 5 to 9.4 and 11 t DM ha-1 respectively) up to an Olsen P of 55 µg g-1 soil. At 176 kg N ha-1, there was a linear yield response (from 3.5 to 6.5 t DM ha-1) as ammonium acetate extracted soil K increased from 80 to 120 µg g-1 soil. A larger yield response to K (from 3.5 to 13.5 t DM ha-1) was measured up to but not above 240 µg K g-1 soil at 352 and 704 kg N ha-1. The yield response to 352 and 704 kg N ha-1 increased with soil S status (from 8.2 to 11.8 t DM ha-1) up to 15 µg calcium phosphate extractable S g-1 soil. These results demonstrated that yield responses to increasing rates of N do not increase above a threshold level of other soil nutrients

A multiplet table for neutral helium (4He I) with transition rates

This paper combines the precise determination of the energy levels of 4He I from calculations and experiments with theoretical transition probabilities to present multiplet tables and finding lists for the fine structure of the helium atom. The tabulated transition rates and oscillator strengths include corrections for singlet-triplet mixing and spin-orbit coupling, but not the higher order relativistic terms nor the finite nuclear mass, although the latter are tabulated for future use. The results are consistent with laboratory lifetimes and oscillator strengths, but very few measurements are accurate enough to be stringent tests. An Appendix discusses the corrections for finite nuclear mass. © 2007. The American Astronomical Society. All rights reserved

Spin-forbidden radiative decay rates from the 3′,3P 1,2 and 3′,1P 1 states of helium

We have calculated atomic helium spontaneous decay rates and absorption oscillator strengths for the spin-forbidden transitions from 3′,3P 1,2 and 3′,1P 1 to all lower 1S 0 and 3S 1 states. In particular we found A 10=44.33(4)′, s -1 for the E1 transition 3′,3P 1-1′,1S 0 and 0.1147(1) s -1 for the M2 transition 3′,3P 2-1′,1S 0. © 2011 American Physical Society