The TOOT00 Redshift Survey of Radio Sources

We present first results from the study of the TOOT00 region consisting of 47 radio sources brighter than 100 mJy at 151 MHz. We have 81% spectroscopic redshift completeness. From the K-z diagram we deduce that the host galaxies are similar to ~3 L* passively evolved elliptical galaxies and thus estimate the redshifts of the 9 sources without a secure spectroscopic redshift yielding a median redshift of 1.287. Above the RLF break we have a quasar fraction f ~ 0.3 although the quasars appear reddened; below the RLF break f -> 0 if we exclude flat-spectrum radio sources. We present a histogram of the number of TOOT00 radio sources versus their redshift which looks broadly like the Willott et al. (2001) prediction for TOOT, although the observed ratio of high to low redshift objects is somewhat lower than the prediction.Comment: 4 pages, 5 figures, to be published in AN (proceedings of the Granada Workshop on High Redshift Radio Galaxies

The environments of double radiogalaxies

Discussed here are simple methods by which the densities and pressures of the gas confining double radiogalaxies can be estimated from optical and x ray data. By applying these methods to an unbiased sample of nearby (z less than 0.5) double radiogalaxies, the author quantifies the empirical relation between the external confining pressure and the internal pressure of the lobes as inferred from the minimum energy argument. This relation is explained by an analytic model in which the lobes are statically confined by ambient material pre-heated in the bow-shock of the advancing radiosource. Such a model allows one to estimate source expansion speeds from a combination of radio and environmental data, and estimate properties of the environment from radio data alone, providing expansion speeds can be estimated from multifrequency observations

The Cosmic Decline in the H2/HI-Ratio in Galaxies

We use a pressure-based model for splitting cold hydrogen into its atomic (HI) and molecular (H2)components to tackle the co-evolution of HI, H2, and star formation rates (SFR) in ~3e7 simulated galaxies in the Millennium simulation. The main prediction is that galaxies contained similar amounts of HI at redshift z=1-5 than today, but substantially more H2, in quantitative agreement with the strong molecular line emission already detected in a few high redshift galaxies and approximately consistent with inferences from studies of the damped Lyman-alpha absorbers seen in the spectra of quasars. The cosmic H2/HI-ratio is predicted to evolve monotonically as Omega(H2)/Omega(HI) (1+z)^1.6. This decline of the H2/HI-ratio as a function of cosmic time is driven by the growth of galactic disks and the progressive reduction of the mean cold gas pressure. Finally, a comparison between the evolutions of HI, H2, and SFRs reveals two distinct cosmic epochs of star formation: an early epoch (z>3), driven by the evolution of Omega(HI+H2), and a late epoch (z<3), driven by the evolution of Omega(H2)/Omega(HI).Comment: 4 pages, 3 figure

Car accidents and credit hire agreements

A motorist whose car is damaged by the negligence of another may recover for the loss suffered, but must take reasonable steps to mitigate that loss. Where a replacement car is hired the charges can be recovered, if the car is needed for use and is similar to the damaged vehicle. Real difficulties arise if the motorist hires on credit. The agreement must comply with regulations applicable to credit agreements and constitute an enforceable contract, and, even then, full recovery of the charges is possible only if the motorist is impecunious. In spite of attempts to calm conflict over these matters, credit hire has prompted a flood of litigation that has often confused issues and created difficult distinctions, which, in turn, have increased tensions in the industry and caused bafflement among motorists

High-z radio galaxies and the `Youth-Redshift Degeneracy'

We discuss a unifying explanation for many `trends with redshift' of radio galaxies which includes the relevance of their ages (time since their jet triggering event), and the marked dependence of their ages on redshift due to the selection effect of imposing a flux-limit. We briefly describe some important benefits which this `youth-redshift degeneracy' brings.Comment: to appear in `The Hy-redshift universe: galaxy formation and evolution at high redshift' eds A.J. Bunker and W.J.M. van Breuge

Gender control:(Re) framing bullying, harassment and gender regulation

In the last decade, discourses of bullying and harassment have featured prominently within educational policy and administration, academic research, popular media, and public dialogue. The ways in which these have been framed has generally been consistent with an individualistic, behavioural perspective that distinctly outlines a ‘bully’ and a ‘victim’- each with specific attributes and performances. This approach arguably simplifies and reduces complex socio-cultural aspects surrounding young people and the wider communities that they are situated within, while simultaneously preventing a deconstruction of gendered, classed and racialised meanings within ‘bullying’ frameworks. This chapter proposes utilising a post-structural feminist approach to re-frame ideas of bullying and harassment as only one indicator of a wider framework of gender regulation. The role of compulsory heterosexuality and the subsequent binary expectations of femininity and masculinity in the production of this regulation will be reviewed in consideration with wider literature. In consideration of these aspects, the concept of a gender regulation framework will be examined to allow more effective exploration of violence in schools

A new approach to social assistance : Latin America's experience with conditional cash transfer programs

Conditional cash transfers are a departure from more traditional approaches to social assistance, that represents an innovative, and increasingly popular channel for the delivery of social services. Conditional cash transfers provide money to poor families, contingent upon certain behavior, usually investments in human capital, such as sending children to school, or bringing them to health centers on a regular basis. They seek both to address traditional short-term income support objectives, as well as to promote the longer-term accumulation of human capital, by serving as a demand-side complement to the supply of health, and education services. Evaluation results from a first generation of programs reveal that this innovative design has been quite successful in addressing many of the criticisms of social assistance, such as poor poverty targeting, disincentive effects, and limited welfare impacts. There is clear evidence of success from programs in Brazil, Colombia, Mexico and Nicaragua in increasing enrollment rates, improving preventive health care and raising household consumption. Despite this promising evidence, many questions remain unanswered about conditional cash transfer programs, including the replicability of their success under different conditions, their role within a broader social protection system, and their long-term effectiveness in preventing the inter- generational transmission of poverty. One of the main challenges facing policymakers today is how to build off of the established success of conditional cash transfer programs, to tackle the more difficult issues of improving the quality of health, and education services, and providing a more holistic approach to both social protection, and chronic poverty.Poverty Assessment,Poverty Impact Evaluation,Health Monitoring&Evaluation,Services&Transfers to Poor,Rural Poverty Reduction

Observational constraints on the spin of the most massive black holes from radio observations

We use recent progress in simulating the production of magnetohydrodynamic jets around black holes to derive the cosmic spin history of the most massive black holes, with masses &gt;~10^8 Msol. Assuming the jet efficiency depends on spin a, we can approximately reproduce the observed `radio loudness' of quasars and the local radio luminosity function. Using the X-ray luminosity function and the local mass function of supermassive black holes, SMBHs we can reproduce the individual radio luminosity functions of radio sources showing high- and low-excitation narrow emission lines. The data favour spin distributions that are bimodal, with one component around spin zero and the other close to maximal spin. In the low-excitation galaxies, the two components have similar amplitudes. For the high-excitation galaxies, the amplitude of the high-spin peak is typically much smaller than that of the low-spin peak. A bimodality should be seen in the radio loudness of quasars. We predict that the low-excitation galaxies are dominated by SMBHs with masses &gt;~10^8 Msol, down to radio luminosity densities ~10^21 W Hz-1 sr-1 at 1.4~GHz. Our model is also able to predict the radio luminosity function at z=1, and predicts it to be dominated by high-excitation galaxies above luminosity densities &gt;~10^26 W Hz-1 sr-1, in full agreement with the observations. From our parametrisation and using the best fitting jet efficiencies there is marginal evidence for evolution in spin: the mean spin increases slightly from ~0.25 at z=1 to ~0.35 at z=0, and the fraction of SMBHs with a&gt;=0.5 increases from 0.16+-0.03 at z=1 to 0.24+-0.09 at z=0. Our results are in excellent agreement with the mean radiative efficiency of quasars, as well as recent cosmological simulations. We discuss the implications in terms of accretion and SMBH mergers, and galactic black holes (Abridged).</a