Reconstructing Native American population history

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.     

Histone demethylase JHDM2A is critical for Tnp1 and Prm1 transcription and spermatogenesis

Recent studies indicate that, similar to other covalent modifications, histone lysine methylation is subject to enzyme-catalysed reversion. So far, LSD1 (also known as AOF2) and the jumonji C (JmjC)-domain-containing proteins have been shown to possess histone demethylase activity. LSD1 catalyses removal of H3K4me2/H3K4me1 through a flavin-adenine-dinucleotide-dependent oxidation reaction. In contrast, JmjC-domain-containing proteins remove methyl groups from histones through a hydroxylation reaction that requires alpha-ketoglutarate and Fe(II) as cofactors. Although an increasing number of histone demethylases have been identified and biochemically characterized, their biological functions, particularly in the context of an animal model, are poorly characterized. Here we use a loss-of-function approach to demonstrate that the mouse H3K9me2/1-specific demethylase JHDM2A (JmjC-domain-containing histone demethylase 2A, also known as JMJD1A) is essential for spermatogenesis. We show that Jhdm2a-deficient mice exhibit post-meiotic chromatin condensation defects, and that JHDM2A directly binds to and controls the expression of transition nuclear protein 1 (Tnp1) and protamine 1 (Prm1) genes, the products of which are required for packaging and condensation of sperm chromatin. Thus, our work uncovers a role for JHDM2A in spermatogenesis and reveals transition nuclear protein and protamine genes as direct targets of JHDM2A.     

Preface： Advanced Thin Film Developments and Nano Structures

In this special issue, we invited a few leading materials researchers to present topics in thin films, coatings, and nano structures. Readers will find most recent developments in topics, including recent advances in hard, tough, and low friction nanocomposite coatings; thin films for coating nanomaterials; electroless plating of silver thin films on porous Al2O3 substrate; CrN/Nano Cr interlayer coatings; nano-structured carbide derived carbon （CDC） films and their tribology; predicting interdiffusion in high-temperature coatings; gallium-catalyzed silica nanowire growth; and corrosion protection properties of organofunctional silanes. Authors are from both national laboratories and academia.     

Multiple ADH genes are associated with upper aerodigestive cancers

Alcohol is an important risk factor for upper aerodigestive cancers and is principally metabolized by alcohol dehydrogenase (ADH) enzymes. We have investigated six ADH genetic variants in over 3,800 aerodigestive cancer cases and 5,200 controls from three individual studies. Gene variants rs1229984 (ADH1B) and rs1573496 (ADH7) were significantly protective against aerodigestive cancer in each individual study and overall (P = 10(-10) and 10(-9), respectively). These effects became more apparent with increasing alcohol consumption (P for trend = 0.0002 and 0.065, respectively). Both gene effects were independent of each other, implying that multiple ADH genes may be involved in upper aerodigestive cancer etiology.     

Model selection and forecasting for long-range dependent processes

Fractionally integrated autoregressive moving-average (ARFIMA) models have proved useful tools in the analysis of time series with long-range dependence. However, little is known about various practical issues regarding model selection and estimation methods, and the impact of selection and estimation methods on forecasts. By means of a large-scale simulation study, we compare three different estimation procedures and three automatic model-selection criteria on the basis of their impact on forecast accuracy. Our results endorse the use of both the frequency-domain Whittle estimation procedure and the time-domain approximate MLE procedure of Haslett and Raftery in conjunction with the AIC and SIC selection criteria, but indicate that considerable care should be exercised when using ARFIMA models. In general, we find that simple ARMA models provide competitive forecasts. Only a large number of observations and a strongly persistent time series seem to justify the use of ARFIMA models for forecasting purposes.     

Critical methods and ideology: An international perspective

This article describes approaches to rhetorical criticism used in recent years, reviews the Critical Systems perspective, and examines the relevance of Critical Systems to rhetorical criticism. The argument is that rhetorical criticism must advance the position for improving the human condition, not simply advance our understanding of human communication.     

Antidiuretic hormone involvement in the release of α-melanocyte-stimulating hormone by hyperosmotic stimuli

Summary In the normal Wistar rat, the plasma -MSH level was raised by hypertonic saline injection (as compared with control rats injected with isotonic saline). No such rise in -MSH followed hypertonic saline administration in the Brattleboro (hereditary diabetes insipidus) animal (compared to isotonic saline injected controls). It is suggested that, in the rat, endogenous antidiuretic hormone is involved in the secretory response of the pars intermedia to osmotic stimuli.     

Algae of Devils Hole, Nevada, Death Valley National Park

We examined algal flora in the aquatic system of Devils Hole, Nevada. The water is seasonally warm, near neutral in pH, and rich in dissolved carbonate, indicative of deeply circulating groundwater flowing through carbonate rock. Most algae were benthic, with only a few planktonic representatives. Eighty-four terminal identifications in 44 genera were recorded, with diatoms and blue-green algae the most speciose groups. Diatoms were major contributors to the grazing food web. Large, mat-forming filamentous algae have an important influence on the physicochemical and general structure of the benthic substrates in Devils Hole.     

Production of pig iron from red mud waste fines using thermal plasma technology

Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite (fixed carbon, 99%) as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.