A review of elliptical and disc galaxy structure, and modern scaling laws

A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

Evaluation of Oxfendazole, Praziquantel and Albendazole against Cystic Echinococcosis: A Randomized Clinical Trial in Naturally Infected Sheep

Cystic Echinococcosis (CE) is a near-cosmopolitan parasitic zoonosis that causes economic losses in many regions of the world. This parasitic infection can be regarded as an emerging or re-emerging disease causing considerable losses in livestock production. CE is produced by the larval cystic stage (hydatid) of the dog parasite Echinococcus granulosus. After infective eggs are ingested, cysts develop mainly in lungs and liver of humans and animals (sheep, cattle, pigs, horses, etc). Infected people may require surgery and/or Albendazole-based chemotherapy. In this study, we evaluated the effects of Oxfendazole alone (an antiparasitic drug used in animals), Oxfendazole plus Praziquantel, and Albendazole plus Praziquantel against hydatid cysts in sheep over 4 to 6 weeks of treatment. All of the treatments in this study were efficacious in killing the larval stages and, therefore, in minimizing the risk of a dog acquiring new infections (taenias). These treatment schemes can be added to control measures in animals and eventually could be used for the treatment of human infection. Further investigations on different schedules of monotherapy or combined chemotherapy are needed, as well as studies to evaluate the safety and efficacy of Oxfendazole in humans

Applying the multi-threat framework of stereotype threat in the context of digital gaming.

Females often report experiencing stigmatisation pertaining to their competency in digital gaming communities. Employing the principles of the multi-Threat framework of stereotype threat, the current research examined the impact of gender-related stereotypes on females' gaming performance and related self-perceptions. In Experiment 1, 90 females were assigned to one of three conditions in which they were primed that their performance would be either diagnostic of their personal (self-As-Target) or gender group's ability (group-As-Target) or would be non-diagnostic of gaming ability (control). In Experiment 2, 90 females were primed that their performance would be judged by a group of other females (in-group source) or males (out-group source), or would be non-diagnostic of ability (control). Participants then completed a casual gaming task, as well as measures of competence beliefs, self-efficacy and self-esteem. Findings from Experiment 1 indicate that neither a self-As-Target nor a group-As-Target stereotype affected significantly gaming performance, or gamerelated self-efficacy, self-esteem and competency beliefs. Findings from Experiment 2 reveal further that females' gaming performance and associated self-perceptions were not impacted significantly by an in-group or out-group source of stereotype threat. The discussion turns to potential explanations for these findings, proposing that females may not perceive negative gender-gaming stereotypes to be an accurate representation of their personal or social group's gaming ability. We also discuss the implications of the experimental design and difficulty, as well as the potential for domain identification to moderate performance outcomes under stereotype threat

Observations of Lyα\alpha Emitters at High Redshift

In this series of lectures, I review our observational understanding of high-$z$ Ly$\alpha$ emitters (LAEs) and relevant scientific topics. Since the discovery of LAEs in the late 1990s, more than ten (one) thousand(s) of LAEs have been identified photometrically (spectroscopically) at $z\sim 0$ to $z\sim 10$. These large samples of LAEs are useful to address two major astrophysical issues, galaxy formation and cosmic reionization. Statistical studies have revealed the general picture of LAEs' physical properties: young stellar populations, remarkable luminosity function evolutions, compact morphologies, highly ionized inter-stellar media (ISM) with low metal/dust contents, low masses of dark-matter halos. Typical LAEs represent low-mass high-$z$ galaxies, high-$z$ analogs of dwarf galaxies, some of which are thought to be candidates of population III galaxies. These observational studies have also pinpointed rare bright Ly$\alpha$ sources extended over $\sim 10-100$ kpc, dubbed Ly$\alpha$ blobs, whose physical origins are under debate. LAEs are used as probes of cosmic reionization history through the Ly$\alpha$ damping wing absorption given by the neutral hydrogen of the inter-galactic medium (IGM), which complement the cosmic microwave background radiation and 21cm observations. The low-mass and highly-ionized population of LAEs can be major sources of cosmic reionization. The budget of ionizing photons for cosmic reionization has been constrained, although there remain large observational uncertainties in the parameters. Beyond galaxy formation and cosmic reionization, several new usages of LAEs for science frontiers have been suggested such as the distribution of {\sc Hi} gas in the circum-galactic medium and filaments of large-scale structures. On-going programs and future telescope projects, such as JWST, ELTs, and SKA, will push the horizons of the science frontiers.Comment: Lecture notes for `Lyman-alpha as an Astrophysical and Cosmological Tool', Saas-Fee Advanced Course 46. Verhamme, A., North, P., Cantalupo, S., & Atek, H. (eds.) --- 147 pages, 103 figures. Abstract abridged. Link to the lecture program including the video recording and ppt files : https://obswww.unige.ch/Courses/saas-fee-2016/program.cg

Genetic and lifestyle risk factors for MRI-defined brain infarcts in a population-based setting

OBJECTIVE: To explore genetic and lifestyle risk factors of MRI-defined brain infarcts (BI) in large population-based cohorts.METHODS: We performed meta-analyses of genome-wide association studies (GWAS) and examined associations of vascular risk factors and their genetic risk scores (GRS) with MRI-defined BI and a subset of BI, namely, small subcortical BI (SSBI), in 18 population-based cohorts (n = 20,949) from 5 ethnicities (3,726 with BI, 2,021 with SSBI). Top loci were followed up in 7 population-based cohorts (n = 6,862; 1,483 with BI, 630 with SBBI), and we tested associations with related phenotypes including ischemic stroke and pathologically defined BI.RESULTS: The mean prevalence was 17.7% for BI and 10.5% for SSBI, steeply rising after age 65. Two loci showed genome-wide significant association with BI: FBN2, p = 1.77 × 10-8; and LINC00539/ZDHHC20, p = 5.82 × 10-9. Both have been associated with blood pressure (BP)-related phenotypes, but did not replicate in the smaller follow-up sample or show associations with related phenotypes. Age- and sex-adjusted associations with BI and SSBI were observed for BP traits (p value for BI, p [BI] = 9.38 × 10-25; p [SSBI] = 5.23 × 10-14 for hypertension), smoking (p [BI] = 4.4 × 10-10; p [SSBI] = 1.2 × 10-4), diabetes (p [BI] = 1.7 × 10-8; p [SSBI] = 2.8 × 10-3), previous cardiovascular disease (p [BI] = 1.0 × 10-18; p [SSBI] = 2.3 × 10-7), stroke (p [BI] = 3.9 × 10-69; p [SSBI] = 3.2 × 10-24), and MRI-defined white matter hyperintensity burden (p [BI] = 1.43 × 10-157; p [SSBI] = 3.16 × 10-106), but not with body mass index or cholesterol. GRS of BP traits were associated with BI and SSBI (p ≤ 0.0022), without indication of directional pleiotropy.CONCLUSION: In this multiethnic GWAS meta-analysis, including over 20,000 population-based participants, we identified genetic risk loci for BI requiring validation once additional large datasets become available. High BP, including genetically determined, was the most significant modifiable, causal risk factor for BI.</p

Nicotinamide's Ups and Downs:Consequences for Fertility, Development, Longevity and Diseases of Poverty and Affluence

Aims and Scope: To further explore the role of dietary nicotinamide in both brain development and diseases, particularly those of ageing. Articles cover neurodegenerative disease and cancer. Also discussed are the effects of nicotinamide, contained in meat and supplements and derived from symbionts, on the major transitions of disease and fertility from ancient times up to the present day. A key role for the tryptophan – NAD ‘de novo’ and immune tolerance pathway are discussed at length in the context of fertility and longevity and the transitions from immune paresis to Treg-mediated immune tolerance and then finally to intolerance and their associated diseases. Abstract: Nicotinamide in human evolution increased cognitive power in a positive feedback loop originally involving hunting. As the precursor to metabolic master molecule NAD it is, as vitamin B3, vital for health. Paradoxically, a lower dose on a diverse plant then cereal-based diet fuelled population booms from the Mesolithic onwards, by upping immune tolerance of the foetus. Increased tolerance of risky symbionts, whether in the gut or TB, that excrete nicotinamide co-evolved as buffers for when diet was inadequate. High biological fertility, despite disease trade-offs, avoided the extinction of Homo sapiens and heralded the dawn of a conscious, creative, and pro-fertility culture. Nicotinamide equity now would stabilise populations and prevent NAD-based diseases of poverty and affluence