MgII absorption systems with W_0 > 0.1 \AA for a radio selected sample of 77 QSOs and their associated magnetic fields at high redshifts

We present a catalogue of MgII absorption systems obtained from high resolution UVES/VLT data of 77 QSOs in the redshift range 0.6 < z < 2.0, and down to an equivalent width W_0 > 0.1 \AA. The statistical properties of our sample are found to be in agreement with those from previous work in the literature. However, we point out that the previously observed increase with redshift of dN/dz for weak absorbers, pertains exclusively to very weak absorbers with W_0 < 0.1 \AA. Instead, dN/dz for absorbers with W_0 in the range 0.1-0.3 \AA actually decreases with redshift, similarly to the case of strong absorbers. We then use this catalogue to extend our earlier analysis of the links between the Faraday Rotation Measure of the quasars and the presence of intervening MgII absorbing systems in their spectra. In contrast to the case with strong MgII absorption systems W_0 > 0.3 \AA, the weaker systems do not contribute significantly to the observed Rotation Measure of the background quasars. This is possibly due to the higher impact parameters of the weak systems compared to strong ones, suggesting that the high column density magnetized material that is responsible for the Faraday Rotation is located within about 50 kpc of the galaxies. Finally, we show that this result also rules out the possibility that some unexpected secondary correlation between the quasar redshift and its intrinsic Rotation Measure is responsible for the association of high Rotation Measure and strong intervening MgII absorption that we have presented elsewhere, since this would have produced an equal effect for the weak absorption line systems, which exhibit a very similar distribution of quasar redshifts.Comment: Accepted for publication in ApJ. 12 pages, 8 figure

Immigration and Support for Anti-Immigrant Parties in Costa Rica

The central research question of this work is whether large or growing immigration populations cause a rise in support for political parties espousing anti-immigration positions. Virtually all of the research on this topic has been focused on the United States and Western Europe. This study, by contrast, looks at the impact of Nicaraguan immigration into neighboring Costa Rica on support for anti-immigration parties in that country. Existing research has found links between such support and immigration levels, as well as other variables such as education, unemployment and ethnic diversity. After reviewing the literature, I generate a series of hypotheses based on previous findings. I also introduce a novel hypothesis which suggests that the relationship between immigration levels and anti-immigration party support may not be linear; as assumed in the literature, but rather curvilinear. Using local level data on immigration levels, socioeconomic characteristics and electoral results from the 2006 national elections, I first used regression analysis to test my hypotheses. In many cases, my findings from this analysis were inconsistent with or even contradictory to the existing literature. A second set of analyses provided preliminary support for the hypothesized curvilinear relationship. This work is designed to contribute to the literature in several areas. First, it marks one oft he first efforts to analyze the dynamics of anti-immigration support in a developing rather than developed country. Second, it represents one of the relatively few attempts to explore the topic at the subnational rather than national level. Finally, it suggests the possibility of an entirely different type of relationship between immigration levels and anti-immigration voting than that assumed in the existing literature

La Picciola : Schottische

https://digitalcommons.library.umaine.edu/mmb-ps/2229/thumbnail.jp

The Effect of Prostaglandin F2-alpha on Synchronizing Estrus in the Ewe

Synchronization of estrus has been attempted by using hormone or hormone-like substances to bring females into estrus simultaneously. The objective of a synchronization program is to manipulate the reproductive process so that all females may be bred during a short pre-defined interval with normal fertility at this breeding. The concept of estrus control and synchronization is intriguing, offering the possibility of more uniform offspring, better use of facilities and labor, concentration of parturition and, in particular, the better utilization of outstanding sires through artificial insemination. The breeding season is the period during which ewes come into heat and will receive the ram. The length of the breeding season varies with the breed of sheep. Some breeds of sheep mate only during a short period in the fall and not any other time of year. Others may come into heat more or less throughout the year at 16- to 17-day intervals but usually miss one or more heat cycles in the spring. During the normal breeding season, ewes come into heat on different days, conceive on different days and, consequently, the lambing period is quite lengthy, with some lambs being dropped almost daily during the entire period. This study was centered around the relative merits of prostaglandin for estrous synchronization of sheep. This review will examine some of the techniques and problems associated with controlling estrus using various regimes of hormones and methods of administration

The Last Eight-Billion Years of Intergalactic CIV Evolution

We surveyed the HST UV spectra of 49 low-redshift quasars for z < 1 CIV candidates, relying solely on the characteristic wavelength separation of the doublet. After consideration of the defining traits of CIV doublets (e.g., consistent line profiles, other associated transitions, etc.), we defined a sample of 38 definite (group G = 1) and five likely (G = 2) doublets with rest equivalent widths W_r for both lines detected at >= 3 sigma. We conducted Monte-Carlo completeness tests to measure the unblocked redshift (dz) and co-moving pathlength (dX) over which we were sensitive to CIV doublets of a range of equivalent widths and column densities. The absorber line density of (G = 1+2) doublets is dN/dX = 4.1+0.7/-0.6 for log N(C^+3) >= 13.2, and dN/dX has not evolved significantly since z = 5. The best-fit power-law to the G = 1 frequency distribution of column densities f(N(C^+3)) = k(N(C^+3)/N_0)^alpha_N has coefficient k = (0.67+0.18/-0.16) x 10^-14 cm^2 and exponent alpha_N = -1.50+0.17/-0.19, where N_0 = 10^14 cm^-2. Using the power-law model of f(N(C^+3)), we measured the C^+3 mass density relative to the critical density: Omega(C^+3) = (6.20+1.82/-1.52) x 10^-8 for 13 <= log N(C^+3) <= 15. This value is a 2.8+/-0.7 increase in Omega(C^+3) compared to the error-weighted mean from several 1 < z < 5 surveys for CIV absorbers. A simple linear regression to Omega(C^+3) over the age of the Universe indicates that Omega(C^+3) has slowly but steadily increased from z = 5 --> 0, with dOmega(C^+3)/dt_age = (0.42+/-0.2) x 10^-8 Gyr^-1.Comment: 61 pages; accepted by ApJ; includes changes based on referee repor

Kinematics of Circumgalactic Gas: Feeding Galaxies and Feedback

We present observations of 50 pairs of redshift z ~ 0.2 star-forming galaxies and background quasars. These sightlines probe the circumgalactic medium (CGM) out to half the virial radius, and we describe the circumgalactic gas kinematics relative to the reference frame defined by the galactic disks. We detect halo gas in MgII absorption, measure the equivalent-width-weighted Doppler shifts relative to each galaxy, and find that the CGM has a component of angular momentum that is aligned with the galactic disk. No net counter-rotation of the CGM is detected within 45 degrees of the major axis at any impact parameter. The velocity offset of the circumgalactic gas correlates with the projected rotation speed in the disk plane out to disk radii of roughly 70 kpc. We confirm previous claims that the MgII absorption becomes stronger near the galactic minor axis and show that the equivalent width correlates with the velocity range of the absorption. We cannot directly measure the location of any absorber along the sightline, but we explore the hypothesis that individual velocity components can be associated with gas orbiting in the disk plane or flowing radially outward in a conical outflow. We conclude that centrifugal forces partially support the low-ionization gas and galactic outflows kinematically disturb the CGM producing excess absorption. Our results firmly rule out schema for the inner CGM that lack rotation and suggest that angular momentum as well as galactic winds should be included in any viable model for the low-redshift CGM.Comment: Accepted for publication in the Astrophysical Journa