The Structure of Cold Dark Matter Halos: Recent Insights from High Resolution Simulations

We review results from recent high resolution cosmological structure formation simulations, namely the Via Lactea I & II and GHALO projects. These simulations study the formation of Milky Way sized objects within a cosmological framework. We discuss the general properties of cold dark matter halos at redshift z = 0 and focus on new insights into the structure of halos we got due to the unprecedented high resolution in these simulations.Comment: 16 pages, 5 figures, invited brief review for MPL

On Physical Scales of Dark Matter Halos

It is common practice to describe formal size and mass scales of dark matter halos as spherical overdensities with respect to an evolving density threshold. Here, we critically investigate the evolutionary effects of several such commonly used definitions and compare them to the halo evolution within fixed physical scales as well as to the evolution of other intrinsic physical properties of dark matter halos. It is shown that, in general, the traditional way of characterizing sizes and masses of halos dramatically overpredicts the degree of evolution in the last 10 Gyr, especially for low-mass halos. This pseudo-evolution leads to the illusion of growth even though there are no major changes within fixed physical scales. Such formal size definitions also serve as proxies for the virialized region of a halo in the literature. In general, those spherical overdensity scales do not coincide with the virialized region. A physically more precise nomenclature would be to simply characterize them by their very definition instead of calling such formal size and mass definitions 'virial'. In general, we find a discrepancy between the evolution of the underlying physical structure of dark matter halos seen in cosmological structure formation simulations and pseudo-evolving formal virial quantities. We question the importance of the role of formal virial quantities currently ubiquitously used in descriptions, models and relations that involve properties of dark matter structures. Concepts and relations based on pseudo-evolving formal virial quantities do not properly reflect the actual evolution of dark matter halos and lead to an inaccurate picture of the physical evolution of our universe.Comment: 17 pages, 14 figures, 1 table, ApJ accepte

Dramatizers in Purik and how they-smack!-evolved

Proceedings of the Workshop B of the 17th Himalayan Languages Symposium (Kobe, 6th-9th, September, 2011

Revisiting The First Galaxies: The effects of Population III stars on their host galaxies

We revisit the formation and evolution of the first galaxies using new hydrodynamic cosmological simulations with the ART code. Our simulations feature a recently developed model for H2 formation and dissociation, and a star formation recipe that is based on molecular rather than atomic gas. Here, we develop and implement a recipe for the formation of metal-free Population III stars in galaxy-scale simulations that resolve primordial clouds with sufficiently high density. We base our recipe on the results of prior zoom-in simulations that resolved the protostellar collapse in pre-galactic objects. We find the epoch during which Pop III stars dominated the energy and metal budget of the first galaxies to be short-lived. Galaxies which host Pop III stars do not retain dynamical signatures of their thermal and radiative feedback for more than 10^8 yr after the lives of the stars end in pair-instability supernovae, even when we consider the maximum reasonable efficiency of the feedback. Though metals ejected by the supernovae can travel well beyond the virial radius of the host galaxy, they typically begin to fall back quickly, and do not enrich a large fraction of the intergalactic medium. Galaxies with total mass in excess of 3 x 10^6 Msun re-accrete most of their baryons and transition to metal-enriched Pop II star formation.Comment: 13 pages, 9 figures, published in Ap

Revisiting The First Galaxies: The epoch of Population III stars

We investigate the transition from primordial Population III (Pop III) star formation to normal Pop II star formation in the first galaxies using new cosmological hydrodynamic simulations. We find that while the first stars seed their host galaxies with metals, they cannot sustain significant outflows to enrich the intergalactic medium, even assuming a top-heavy initial mass function. This means that Pop III star formation could potentially continue until z~6 in different unenriched regions of the universe, before being ultimately shut off by cosmic reionization. Within an individual galaxy, the metal production and stellar feedback from Pop II stars overtake Pop III stars in 20-200 Myr, depending on galaxy mass.Comment: 9 pages, 7 figures, published in Ap

Safe start at home : what parents of newborns need after early discharge from hospital - a focus group study

The length of postpartum hospital stay is decreasing internationally. Earlier hospital discharge of mothers and newborns decreases postnatal care or transfers it to the outpatient setting. This study aimed to investigate the experiences of new parents and examine their views on care following early hospital discharge.; Six focus group discussions with new parents (n = 24) were conducted. A stratified sampling scheme of German and Turkish-speaking groups was employed. A 'playful design' method was used to facilitate participants communication wherein they used blocks and figurines to visualize their perspectives on care models The visualized constructions of care models were photographed and discussions were audio-recorded and transcribed verbatim. Text and visual data was thematically analyzed by a multi-professional group and findings were validated by the focus group participants.; Following discharge, mothers reported feeling physically strained during recuperating from birth and initiating breastfeeding. The combined requirements of infant and self-care needs resulted in a significant need for practical and medical support. Families reported challenges in accessing postnatal care services and lacking inter-professional coordination. The visualized models of ideal care comprised access to a package of postnatal care including monitoring, treating and caring for the health of the mother and newborn. This included home visits from qualified midwives, access to a 24-h helpline, and domestic support for household tasks. Participants suggested that improving inter-professional networks, implementing supervisors or a centralized coordinating center could help to remedy the current fragmented care.; After hospital discharge, new parents need practical support, monitoring and care. Such support is important for the health and wellbeing of the mother and child. Integrated care services including professional home visits and a 24-hour help line may help meet the needs of new families

Prevalence and predictors of premenstrual syndrome and premenstrual dysphoric disorder in a population-based sample

The study aimed at assessing the prevalence of premenstrual symptoms and of premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) in a population-based sample of women of the entire reproductive age range, as well as to analyse predictors of PMS and PMDD in terms of socio-demographic, health status and health behavioural factors. A set of questions on PMS-based on the premenstrual syndrome screening tool developed by Steiner et al., translated into German and piloted—was integrated into the written questionnaire of the 2007 Swiss Health Survey. Weighted prevalence rates and multivariable regression analysis for the outcome variables PMS and PMDD were calculated. A total of 3,913 women aged 15 to 54years answered the questions on PMS symptoms, and 3,522 of them additionally answered the questions on interference of PMS with life. Ninety one percent of the participants reported at least one symptom, 10.3% had PMS and 3.1% fulfilled the criteria for PMDD. The prevalence of PMS was higher in non-married women, in women aged 35-44years and in women of the Italian-speaking region of Switzerland. Both PMS and PMDD were strongly associated with poor physical health and psychological distress. Socio-cultural factors seem to determine the prevalence, perception and handling of PMS. Considering the association with poor physical health and high psychological distress, a broader underlying vulnerability in women qualifying for PMDD must be assumed and should be taken into account in clinical management as well as in future research in this fiel

A performance analysis of participating life insurance contracts

Traditional life insurance products, in particular participating life insurance contracts, are often criticized. Their performance is often said to be poor compared to other investment alternatives. Interestingly, this perception appears to persist although very little research has been conducted into the performance of participating life insurance contracts. But are participating life insurance contracts actually bad for policyholders? We conduct a performance analysis based on contracts offered in the German market, in order to provide evidence to support decision making by policyholder

A three-state model for the regulation of telomerase by TERRA and hnRNPA1

Telomeres, the physical ends of eukaryotic chromosomes, are transcribed into telomeric repeat-containing RNA (TERRA), a large non-coding RNA, which forms an integral part of telomeric heterochromatin. In vitro, naked TERRA molecules are efficient inhibitors of human telomerase, base-pairing via their 5′-UUAGGG-3′ repeats with the template sequence of telomerase RNA, in addition to contacting the telomerase reverse transcriptase protein subunit. In vivo, however, TERRA-mediated inhibition of telomerase can be prevented by unknown mechanisms. Also, heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) has been implicated in telomere length control. In vivo, TERRA is partially associated with hnRNPA1, and hnRNPA1 is also detected at telomeres. We demonstrate that on binding of TERRA, hnRNPA1 can alleviate the TERRA-mediated inhibition of telomerase. However, when in excess over TERRA, hnRNPA1 becomes itself an inhibitor of telomere extension, on binding of the telomeric DNA substrate. Yet, hnRNPA1 has no notable direct effects on the telomerase catalysis. Our in vitro results suggest that TERRA-mediated telomerase inhibition may be prevented by hnRNPA1 in vivo. Telomere extension by telomerase may require balanced levels of TERRA and hnRNPA1 at telomeres. Thus, TERRA and hnRNPA1 can function as a bimolecular regulator to turn telomerase and the telomere on and of

Central City Exploitation by Urban Sprawl? Evidence from Swiss Local Communities

This paper investigates spatial spillovers in local spending decisions between the center and the surrounding local communities by using panel data of the canton of Lucerne during the 1990s. Due to the geographical fragmentation with a major central city and some 100 small suburban local communities within a distance from 4 to 55 kilometers to the center this area represents a particularly useful database in order to test the relevance of spatial interactions in a small metropolitan area. The empirical evidence confirms strategic interactions among suburban governments and the central city only for public education, health and environmental spending. There are no spatial interactions with the central city for overall government spending.spatial spillovers, strategic interaction, central city exploitation