50 research outputs found
The molecular phylogeny of eph receptors and ephrin ligands
<p>Abstract</p> <p>Background</p> <p>The tissue distributions and functions of Eph receptors and their ephrin ligands have been well studied, however less is known about their evolutionary history. We have undertaken a phylogenetic analysis of Eph receptors and ephrins from a number of invertebrate and vertebrate species.</p> <p>Results</p> <p>Our findings indicate that Eph receptors form three major clades: one comprised of non-chordate and cephalochordate Eph receptors, a second comprised of urochordate Eph receptors, and a third comprised of vertebrate Eph receptors. Ephrins, on the other hand, fall into either a clade made up of the non-chordate and cephalochordate ephrins plus the urochordate and vertebrate ephrin-Bs or a clade made up of the urochordate and vertebrate ephrin-As.</p> <p>Conclusion</p> <p>We have concluded that Eph receptors and ephrins diverged into A and B-types at different points in their evolutionary history, such that primitive chordates likely possessed an ancestral ephrin-A and an ancestral ephrin-B, but only a single Eph receptor. Furthermore, ephrin-As appear to have arisen in the common ancestor of urochordates and vertebrates, whereas ephrin-Bs have a more ancient bilaterian origin. Ancestral ephrin-B-like ligands had transmembrane domains; as GPI anchors appear to have arisen or been lost at least 3 times.</p
Job Insecurity: Differential Effects of Subjective and Objective Measures on Life Satisfaction Trajectories of Workers Aged 27â30 in Germany
Job insecurity has become increasingly evident in European countries in recent years. In Germany, legislation has increased insecurity through erosion of the standard employment relationship. Fixed-term contracts are central to definitions of insecurity based on atypical or precarious work but there is still limited understanding of what creates insecurity and how it affects workers. Drawing on Bourdieuâs thesis that âinsecurity is everywhereâ, the relationships between subjective and objective measures of insecurity are examined for their impact on the 5-year trajectories of life satisfaction of men and women in the age group 27â30. Latent growth curve analysis of data from the German Socio-Economic Panel for 2010â2014 highlights the adverse and lasting effects of subjective concerns about job insecurity on life satisfaction trajectories. This association cuts across educational groups, with far reaching implications as subjective concerns about job security permeate young workerâs lives well beyond the objective condition of being employed on a fixed-term contract
Abundance and scarcity: classical theories of money, bank balance sheets and business models, and the British restriction of 1797â1818.
The thesis looks through the lens of bank balance sheet accounting to investigate the structural change in the British banking system between 1780 and 1832, and how classical quantity theorists of money attempted to respond to the ensuing financialisation of the wartime economy with its growing reliance on credit funded with paper-based instruments (the âVansittart systemâ of war finance).
The thesis combines contributions to three separate fields to construct a holistic historical example of the challenges faced by monetary economists when âmodellingâ financial innovation, credit growth, âfringeâ banking, and agent incentives â at a time of radical experimentation: the suspension of the 80-year-old gold standard (âthe Restrictionâ).
First, critical text analysis of the history of economics argues that the 1809-10 debate between Ricardo and Bosanquet at the peak of the credit boom, bifurcated classical theory into two timeless competing policy paradigms advocating the âScarcityâ or âAbundanceâ of money relative to exchange transactions. The competing hypotheses regarding the role of money and credit are identified and the rest of the thesis examines the archival evidence for each.
Second, the core of the thesis contributes to the historical literature on banking in relation to money by reconstructing a taxonomy of bank business models, their relationships with the London inter-bank settlement system, and their responses to the Restriction - drawing on some 17,000 mostly new data points collected from the financial records of London and Country banks.
The final section contributes to the economic history of money by constructing aggregated views of total bank liabilities from the firm-level data, scaled to recently available British GDP estimates. These are examined to establish (with hindsight) the relative merits and lacuna of the competing theoretical hypotheses postulated by political economists. It was the period of deleveraging after 1810 that revealed the lacuna of both paradigms
Dynamic PET imaging reveals heterogeneity of skeletal muscle insulin resistance.
PURPOSE: Skeletal muscle insulin resistance (IR) often precedes hyperglycemia and type 2 diabetes. However, variability exists within different skeletal muscle types and can be influenced by 3 primary steps of control: glucose delivery, transport, and phosphorylation. We performed dynamic positron emission tomography imaging studies to determine the extent to which heterogeneity in muscle type and control of insulin action contribute to IR.
METHODS:
Thirteen volunteers from normal weight to obese underwent dynamic positron emission tomography imaging of [15O]H2O, [11C]3-O-methylglucose, and [18F]fluorodeoxyglucose, measuring delivery, transport, and phosphorylation rates, respectively, in soleus and tibialis anterior muscle during a hyperinsulinemic-euglycemic clamp. Subjects were classified as insulin-sensitive (IS) or insulin-resistant (IR) based on the median systemic glucose infusion rate needed to maintain euglycemia
Hiperceratose focal acral associada Ă hipocromia de dermatĂłglifos Focal acral hyperkeratosis with hypochromic dermatoglyphics
Hiperceratose focal acral Ă© dermatose rara caracterizada por pĂĄpulas ceratĂłticas acrais que afetam preferencialmente as superfĂcies marginais das mĂŁos e dos pĂ©s, pertencendo ao grupo das hiperceratoses marginais. Apresentamos variante inĂ©dita de mulher de 45 anos de idade, branca, dona-de-casa, sem histĂłria familiar, com lesĂ”es ceratĂłticas papulosas localizadas nos pĂ©s e hipocromia de dermatĂłglifos na regiĂŁo afetada. Histologicamente apresentou hiperortoceratose, desnĂvel da epiderme (degrau), acantose e hipergranulose. Os tratamentos com ceratolĂticos tĂłpicos foram ineficientes, de forma semelhante aos casos descritos na literatura atual.<br>Focal acral hyperkeratosis is a rare condition, characterized by acral keratotic papules that preferably affect hand and foot surfaces, and are included in the spectrum of marginal papular keratodermas. We report an unpublished variant of this condition, the case of a 45-year-old Caucasian woman with acral keratotic papular lesions and hypochromic dermatoglyphics in the feet. Histological examination revealed orthohyperkeratosis, depression of the epidermis, acanthosis and hypergranulosis. Topical treatments with keratolytics were ineffective, similarly to previously described cases