Ionized Gas in Damped Lyman Alpha Protogalaxies: II. Comparison Between Models and the Kinematic Data

We test semi-analytic models for galaxy formation with accurate kinematic data of damped Lyman alpha protogalaxies (DLAs) presented in the companion paper I. The models envisage centrifugally supported exponential disks at the centers of dark matter halos which are filled with ionized gas undergoing radial infall to the disks. The halo masses are drawn from cross-section weighted mass distributions predicted by CDM cosmogonies, or by the null hypothesis (TF model) that the dark matter mass distribution has not evolved since z ~ 3. In our models, C IV absorption lines detected in DLAs arise in infalling ionized clouds while the low-ion absorption lines arise from neutral gas in the disks. Using Monte Carlo methods we find: (a) The CDM models are incompatible with the low-ion statistics at more than 99% confidence whereas some TF models cannot be excluded at more than 88% confidence. (b) Both CDM and TF models agree with the observed distribution of C IV velocity widths. (c) The CDM models generate differences between the mean velocities of C IV and low ion profiles in agreement with the data, while the TF model produces differences in the means that are too large. (d) Both CDM and TF models produce ratios of C IV to low-ion velocity widths that are too large. (e) Both CDM and TF models generate C IV versus low-ion cross-correlation functions incompatible with the data. While it is possible to select model parameters resulting in consistency with the data, the disk-halo configuration assumed in both cosmogonies still does not produce significant overlap in velocity space between C IV low-ion velocity profiles. We conjecture that including angular momentum of the infalling clouds will increase the overlap between C IV and low-ion profiles.Comment: 18 pages, 12 Figures, Accepted for publication in the Dec. 20 issue of the Astrophysical Journa

Internal Migration and Regional Population Dynamics in Europe: Norway Case Study

This paper reports on internal migration and regional population dynamics in Norway. It examines internal migration patterns and trends in two years, 1984 and 1994, and compares them. Norway's population maintains relatively high population growth by European standards, fuelled by continuing natural increase and net migration from outside the country. About half of Norway's municipalities lost population in aggregate over the 1984 to 1994. These municipalities are concentrated in the Centre-North and interior of southern Norway. There is evidence that communities with the lowest densities and least centrality are losing population through internal migration. Although the direction of migration is towards denser and more central places, this is a product mainly of the migration of young people when the migration streams are broken down by age, the resulting tales show that the largest urban areas are experiencing net losses from middle age and upwards. There is little direct evidence of net positive migration flows to rural remote areas for the population as a whole. Migration flows out of the Oslo region are to other municipalities within commuting range. This deconcentration should therefore be identified as extended suburanisation rather than counter-urbanisation. Throughout the current report the role of life course stage in influencing the direction of migration has been stressed. Most often the overall pattern of population shifts conceal very different flow structures for family migrants, young adults, older workers, retirees and the elderly. In this respect internal migration dynamics in Norway strongly resemble those in other West European countries. Economic factors have an important influence on migration patterns. Municipalities with an economic concentration in service industries attract internal migrants while those specialised in primary industry suffer migration outflows consequent on the decline of or productivity improvements in their economic activities. There is a strong gradient of increasing net outflows with increasing levels of unemployment

Analysis of pressure distortion testing

The development of a distortion methodology, method D, was documented, and its application to steady state and unsteady data was demonstrated. Three methodologies based upon DIDENT, a NASA-LeRC distortion methodology based upon the parallel compressor model, were investigated by applying them to a set of steady state data. The best formulation was then applied to an independent data set. The good correlation achieved with this data set showed that method E, one of the above methodologies, is a viable concept. Unsteady data were analyzed by using the method E methodology. This analysis pointed out that the method E sensitivities are functions of pressure defect level as well as corrected speed and pattern

Renal replacement therapies in neonates: Issues and ethics.

Chronic irreversible kidney disease requiring dialysis is rare in the neonate. Many such neonates are diagnosed following antenatal ultrasound with congenital abnormalities of the kidneys and urinary tract. There is an increased incidence of prematurity and infants that are small for gestational age. Given the natural improvement in renal function that occurs in the neonatal period, some with extremely poor renal function may, with careful management of fluid and electrolytes, be kept off dialysis until the creatinine reaches a nadir when a definitive plan can be made. There is a very high incidence of comorbidity and this affects survival, which for those on dialysis is about 80% at five years. The multiple and complex ethical issues surrounding the management of these very young children are discussed

Immunity and the infant GI-tract

No Abstract. South African Family Practice Vol. 47(5) 2005: 6

Protein energy wasting; what is it and what can we do to prevent it?

Some children with declining height and BMI SDS fail to respond to optimisation of nutritional intake. As well as poor growth, they have muscle wasting and relative preservation of body fat. This is termed protein energy wasting (PEW). The process results from an interaction of chronic inflammation alongside poor nutritional intake. This review discusses the causes and potential preventative therapies for PEW

Meson Synchrotron Emission from Central Engines of Gamma-Ray Bursts with Strong Magnetic Fields

Gamma-ray bursts (GRBs) are presumed to be powered by still unknown central engines for the timescales in the range $1ms \sim$ a few s. We propose that the GRB central engines would be a viable site for strong meson synchrotron emission if they were the compact astrophysical objects such as neutron stars or rotating black holes with extremely strong magnetic fields $H \sim10^{12} - 10^{17}G$ and if protons or heavy nuclei were accelerated to ultra-relativistic energies of order $\sim 10^{12}-10^{22}eV$. We show that the charged scalar mesons like $\pi^{\pm}$ and heavy vector mesons like $\rho$, which have several decay modes onto $\pi^{\pm}$, could be emitted with high intensity a thousand times larger than photons through strong couplings to ultra-relativistic nucleons. These meson synchrotron emission processes eventually produce a burst of very high-energy cosmic neutrinos with $10^{12} eV \leq E_{\nu}$. These neutrinos are to be detected during the early time duration of short GRBs.Comment: 12 pages, 4 figures. Accepted for publication in the Astrophysical Journal Letter

Developing a national dental education research strategy:priorities, barriers and enablers

Objectives: This study aimed to identify national dental education research (DER) priorities for the next 3-5 years and to identify barriers and enablers to DER. Setting: Scotland Participants: In this two-stage online questionnaire study we collected data with multiple dental professions (e.g. dentistry, dental nursing, dental hygiene) and stakeholder groups (e.g. learners, clinicians, educators, managers, researchers, academics). Eighty-five participants completed the Stage 1 qualitative questionnaire and 649 participants the Stage 2 quantitative questionnaire. Results: Eight themes were identified at Stage 1. Of the 24 DER priorities identified, the top three were: role of assessments in identifying competence; undergraduate curriculum prepares for practice; and promoting teamwork. Following exploratory factor analysis, the 24 items loaded onto four factors: teamwork and professionalism, measuring and enhancing performance, dental workforce issues, and curriculum integration and innovation. Barriers and enablers existed at multiple levels: individual, interpersonal, institutional structures and cultures, and technology. Conclusion: This priority setting exercise provides a necessary first step to developing a national DER strategy capturing multiple perspectives. Promoting DER requires improved resourcing alongside efforts to overcome peer stigma and lack of valuing and motivation