Derivation of Distances with the Tully-Fisher Relation: The Antlia Cluster

The Tully-Fisher relation is a correlation between the luminosity and the HI 21cm line width in spiral galaxies (LLW relation). It is used to derive galaxy distances in the interval 7 to 100 Mpc. Closer, the Cepheids, TRGB and Surface Brightness Fluctuation methods give a better accuracy. Further, the SNIa are luminous objects still available for distance measurement purposes, though with a dramatically lower density grid of measurements on the sky. Galaxies in clusters are all at the same distance from the observer. Thus the distance of the cluster derived from a large number of galaxies (N) has an error reduced according to the square root of N. However, not all galaxies in a cluster are suitable for the LLW measurement. The selection criteria we use are explained hereafter; the important point being to avoid Malmquist bias and to not introduce any systematics in the distance measurement.Comment: Moriond0

Earnings and Consumption Dynamics: A Nonlinear Panel Data Framework

We develop a new quantile‐based panel data framework to study the nature of income persistence and the transmission of income shocks to consumption. Log‐earnings are the sum of a general Markovian persistent component and a transitory innovation. The persistence of past shocks to earnings is allowed to vary according to the size and sign of the current shock. Consumption is modeled as an age‐dependent nonlinear function of assets, unobservable tastes, and the two earnings components. We establish the nonparametric identification of the nonlinear earnings process and of the consumption policy rule. Exploiting the enhanced consumption and asset data in recent waves of the Panel Study of Income Dynamics, we find that the earnings process features nonlinear persistence and conditional skewness. We confirm these results using population register data from Norway. We then show that the impact of earnings shocks varies substantially across earnings histories, and that this nonlinearity drives heterogeneous consumption responses. The framework provides new empirical measures of partial insurance in which the transmission of income shocks to consumption varies systematically with assets, the level of the shock, and the history of past shocks

Non-functional immunoglobulin G transcripts in a case of hyper-immunoglobulin M syndrome similar to type 4

86% of immunoglobulin G (IgG) heavy-chain gene transcripts were found to be non-functional in the peripheral blood B cells of a patient initially diagnosed with common variable immunodeficiency, who later developed raised IgM, whereas no non-functionally rearranged transcripts were found in the cells of seven healthy control subjects. All the patient's IgM heavy-chain and κ light-chain transcripts were functional, suggesting that either non-functional rearrangements were being selectively class-switched to IgG, or that receptor editing was rendering genes non-functional after class-switching. The functional γ-chain sequences showed a normal rate of somatic hypermutation while non-functional sequences contained few somatic mutations, suggesting that most came from cells that had no functional gene and therefore were not receiving signals for hypermutation. However, apoptosis of peripheral blood lymphocytes was not impaired. No defects have been found in any of the genes currently known to be responsible for hyper-IgM syndrome but the phenotype fits best to type 4

Elastic instability in stratified core annular flow

We study experimentally the interfacial instability between a layer of dilute polymer solution and water flowing in a thin capillary. The use of microfluidic devices allows us to observe and quantify in great detail the features of the flow. At low velocities, the flow takes the form of a straight jet, while at high velocities, steady or advected wavy jets are produced. We demonstrate that the transition between these flow regimes is purely elastic -- it is caused by viscoelasticity of the polymer solution only. The linear stability analysis of the flow in the short-wave approximation captures quantitatively the flow diagram. Surprisingly, unstable flows are observed for strong velocities, whereas convected flows are observed for low velocities. We demonstrate that this instability can be used to measure rheological properties of dilute polymer solutions that are difficult to assess otherwise.Comment: 4 pages, 4 figure

Species-wide distribution of highly polymorphic minisatellite markers suggests past and present genetic exchanges among house mouse subspecies

Global analysis of four minisatellite loci in House Mouse reveals unexpected long-range gene flow between populations and subspecies

An effect size statistical framework for investigating sexual dimorphism in non-avian dinosaurs and other extinct taxa

Despite reports of sexual dimorphism in extinct taxa, such claims in non-avian dinosaurs have been underrepresented recently (~the last decade) and often criticized. Since dimorphism is widespread in sexually reproducing organisms today, underrepresentation might suggest either methodological shortcomings or that this diverse group exhibited highly unusual reproductive biology. Univariate significance testing, especially for bimodality, is ineffective and prone to false negatives. Species recognition and mutual sexual selection hypotheses, therefore, may not be required to explain supposed absence of sexual dimorphism across the grade, likely a type II error. Instead, multiple lines of evidence support sexual selection and variation of structures consistent with secondary sexual characteristics, strongly suggesting sexual dimorphism in non-avian dinosaurs. We propose a framework for studying sexual dimorphism in fossils, focusing on likely secondarily sexual traits and testing against all alternate hypotheses for variation in them using multiple lines of evidence. We use effect size statistics appropriate for low sample sizes, rather than significance testing, to analyze potential divergence of growth curves in traits and constrain estimates for dimorphism magnitude. In many cases, estimates of sexual variation can be reasonably accurate, and further developments in methods to improve sex assignments and account for intrasexual variation (e.g., mixture modelling) will improve accuracy. It is better to compare estimates for the magnitude of and support for dimorphism between datasets than to dichotomously reject or fail to reject monomorphism in a single species, enabling the study of sexual selection across phylogenies and time. We defend our approach with simulated and empirical data, including dinosaur data, showing that even simple approaches can yield fairly accurate estimates of sexual variation in many cases, allowing for comparison of species with high and low support for sexual variation.Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: PLR 1341645 and FRES 192588

Large-scale signatures of unconsciousness are consistent with a departure from critical dynamics

Loss of cortical integration and changes in the dynamics of electrophysiological brain signals characterize the transition from wakefulness towards unconsciousness. The common mechanism underlying these observations remains unknown. In this study we arrive at a basic model, which explains these empirical observations based on the theory of phase transitions in complex systems. We studied the link between spatial and temporal correlations of large-scale brain activity recorded with functional magnetic resonance imaging during wakefulness, propofol-induced sedation and loss of consciousness, as well as during the subsequent recovery. We observed that during unconsciousness activity in frontal and thalamic regions exhibited a reduction of long-range temporal correlations and a departure of functional connectivity from the underlying anatomical constraints. These changes in dynamics and anatomy-function coupling were correlated across participants, suggesting that temporal complexity and an efficient exploration of anatomical connectivity are inter-related phenomena. A model of a system exhibiting a phase transition reproduced our findings, as well as the diminished sensitivity of the cortex to external perturbations during unconsciousness. This theoretical framework unifies different empirical observations about brain activity during unconsciousness and predicts that the principles we identified are universal and independent of the causes behind loss of awareness.Comment: to appear in Journal of the Royal Society Interfac