Spin dynamics and magnetic interactions of Mn dopants in the topological insulator Bi2_2Te3_3

The magnetic and electronic properties of the magnetically doped topological insulator Bi$_{\rm 2-x}$Mn$_{\rm x}$Te$_3$ were studied using electron spin resonance (ESR) and measurements of static magnetization and electrical transport. The investigated high quality single crystals of Bi$_{\rm 2-x}$Mn$_{\rm x}$Te$_3$ show a ferromagnetic phase transition for $x\geq 0.04$ at $T_{C}\approx 12$ K. The Hall measurements reveal a p-type finite charge-carrier density. Measurements of the temperature dependence of the ESR signal of Mn dopants for different orientations of the external magnetic field give evidence that the localized Mn moments interact with the mobile charge carriers leading to a Ruderman-Kittel-Kasuya-Yosida-type ferromagnetic coupling between the Mn spins of order 2-3 meV. Furthermore, ESR reveals a low-dimensional character of magnetic correlations that persist far above the ferromagnetic ordering temperature

Heritability of Body Mass Index: A comparison between the Netherlands and Spain.

A high body mass index (BMI) is commonly used as an index of overweight and obesity. There is persistent evidence of high heritability for variation in BMI, but the effects of common environment appear inconsistent across different European countries. Our objective was to compare genetic and environmental effects on BMI in a sample of twins from two different European countries with distinct population and cultural backgrounds. We analysed data of adult female twins from the Netherlands Twin Register (222 monozygotic [MZ] and 103 dizygotic [DZ] pairs) and the Murcia Twin Register (Spain; 202 MZ and 235 DZ pairs). BMI was based on self-reported weight and height. Dutch women were taller and heavier, but Spanish women had a significantly higher mean BMI. The age related weight increase was significantly stronger in the Spanish sample. Genetic analyses showed that genetic factors are the main contributors to variation in height, weight, and BMI, within both countries. For height and weight, estimates of genetic variances did not differ, but for height, the estimate for the environmental variance was significantly larger in Spanish women. For BMI, both the genetic and the environmental variance components were larger in Spanish than in Dutch women

On the Dynamics of the Evolution of the HIV Infection

We use a cellular automata model to study the evolution of HIV infection and the onset of AIDS. The model takes into account the global features of the immune response to any pathogen, the fast mutation rate of the HIV and a fair amount of spatial localization. Our results reproduce quite well the three-phase pattern observed in T cell and virus counts of infected patients, namely, the primary response, the clinical latency period and the onset of AIDS. We have also found that the infected cells may organize themselves into special spatial structures since the primary infection, leading to a decrease on the concentration of uninfected cells. Our results suggest that these cell aggregations, which can be associated to syncytia, leads to AIDS.Comment: 4 pages, 3 postscript figure

Evidence for the existence of powder sub-populations in micronized materials : Aerodynamic size-fractions of aerosolized powders possess distinct physicochemical properties

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Purpose: To investigate the agglomeration behaviour of the fine ( 12.8 µm) particle fractions of salmeterol xinafoate (SX) and fluticasone propionate (FP) by isolating aerodynamic size fractions and characterising their physicochemical and re-dispersal properties. Methods: Aerodynamic fractionation was conducted using the Next Generation Impactor (NGI). Re-crystallized control particles, unfractionated and fractionated materials were characterized for particle size, morphology, crystallinity and surface energy. Re-dispersal of the particles was assessed using dry dispersion laser diffraction and NGI analysis. Results: Aerosolized SX and FP particles deposited in the NGI as agglomerates of consistent particle/agglomerate morphology. SX particles depositing on Stages 3 and 5 had higher total surface energy than unfractionated SX, with Stage 5 particles showing the greatest surface energy heterogeneity. FP fractions had comparable surface energy distributions and bulk crystallinity but differences in surface chemistry. SX fractions demonstrated higher bulk disorder than unfractionated and re-crystallized particles. Upon aerosolization, the fractions differed in their intrinsic emission and dispersion into a fine particle fraction (< 5.0 µm). Conclusions: Micronized powders consisted of sub-populations of particles displaying distinct physicochemical and powder dispersal properties compared to the unfractionated bulk material. This may have implications for the efficiency of inhaled drug deliveryPeer reviewe

The geographic mosaic of herbicide resistance evolution in the common morning glory, Ipomoea purpurea: Evidence for resistance hotspots and low genetic differentiation across the landscape

Strong human‐mediated selection via herbicide application in agroecosystems has repeatedly led to the evolution of resistance in weedy plants. Although resistance can occur among separate populations of a species across the landscape, the spatial scale of resistance in many weeds is often left unexamined. We assessed the potential that resistance to the herbicide glyphosate in the agricultural weed Ipomoea purpurea has evolved independently multiple times across its North American range. We examined both adaptive and neutral genetic variations in 44 populations of I. purpurea by pairing a replicated dose–response greenhouse experiment with SSR genotyping of experimental individuals. We uncovered a mosaic pattern of resistance across the landscape, with some populations exhibiting high‐survival postherbicide and other populations showing high death. SSR genotyping revealed little evidence of isolation by distance and very little neutral genetic structure associated with geography. An approximate Bayesian computation (ABC) analysis uncovered evidence for migration and admixture among populations before the widespread use of glyphosate rather than the very recent contemporary gene flow. The pattern of adaptive and neutral genetic variations indicates that resistance in this mixed‐mating weed species appears to have evolved in independent hotspots rather than through transmission of resistance alleles across the landscape.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113156/1/eva12290_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113156/2/eva12290.pd

Stature and sibship: historical evidence

This paper examines historical evidence for a quality–quantity trade-off between sibship size and height as an indicator of health. The existing literature has focused more on education than on health and it has produced mixed results. Historical evidence is limited by the lack of household-level data with which to link an individual’s height with his or her childhood circumstances. Nevertheless a few recent studies have shed light on this issue. Evidence for children in interwar Britain and for soldiers born in the 1890s who enlisted in the British army at the time of World War I is reviewed in detail. Both studies support the idea of a significant trade-off, partly due to income dilution and partly because, in these settings, large families were a conduit for infection. Evidence from country-level time series is consistent with this view. The fertility decline that began in the late nineteenth century made a modest but nevertheless significant contribution to the overall increase in heights during the following half-century

Does the lateral intercondylar ridge disappear in ACL deficient patients?

The aim of this study was to determine whether there is a difference in the presence of the lateral intercondylar ridge and the lateral bifurcate ridge between patients with sub-acute and chronic ACL injuries. We hypothesized that the ridges would be present less often with chronic ACL deficiency. Twenty-five patients with a chronic ACL injury were matched for age and gender to 25 patients with a sub-acute ACL injury. The lateral intercondylar ridge and lateral bifurcate ridge were scored as either present, absent, or indeterminate due to insufficient visualization by three blinded observers. The kappa for the three observers was .61 for the lateral intercondylar ridge and .58 for the lateral bifurcate ridge. The lateral intercondylar ridge was present in 88% of the sub-acute patients and 88% of the chronic patients. The lateral bifurcate ridge was present in 48% of the sub-acute and 48% of the chronic patients. This matched-pairs case–control study was unable to show a difference in the presence of the femoral bony ridges between patients with acute and chronic ACL injuries. The authors would suggest looking for the ridges as a landmark of the native ACL insertion site during ACL reconstruction in both acute and chronic ACL injuries

Disturbances and noise: Defining furrow-form enamel hypoplasia

Objectives The investigation of the record of growth locked in dental enamel provides a unique opportunity to build a comprehensive picture of growth disruption episodes during childhood. This study presents a new methodological basis for the analysis of enamel growth disruptions (enamel hypoplasia) using incremental microstructures of enamel. Methods A three?dimensional technique based upon use of an Alicona 3D Infinite Focus imaging microscope and software is used to record developmental features in the enamel of human permanent mandibular lateral incisors of one individual from the Neolithic site of Çatalhöyük (Turkey). Using this new technique, perikymata are measured down the longitudinal axis of the crown from the incisal margin to the cervix and perikyma spacing profiles are constructed with this new technique. A mathematical basis for the detection of spacing anomalies, which serve as indicators of enamel hypoplasia is presented based upon these profiles. Results Three clearly delineated defects were identified visually, then matched and confirmed metrically using the enamel surface and perikyma spacing profiles. Discussion Human growth has often been used as an indicator of health in past societies because of developmental sensitivity to fluctuations in nutritional status and disease load. Hence, standardization of furrow?form defect identification is of crucial importance for reducing the amount of current subjectivity in the determination of a threshold for the identification of defects among individuals of past populations. The method presented here, which is based on microscopic images of the tooth crown as well as recorded measurements of incremental structures, represents a combined visual?metric approach using LOWESS residuals, and as such provides a substantial advancement to previous methods. It is therefore recommended that additional studies be carried out with this methodology to determine whether this method improves the reliability of enamel defect identification among individuals recovered from bioarchaeological contexts

Does Height Affect Labor Supply? Implications of Product Variety and Caloric Needs

The positive correlation between hourly wages and height, which results in higher labor supply of tall individuals, is well-documented in the literature. Accepting the utilitarian perspective and assuming that height does not affect utility implies that linking income taxes to height is welfare improving. This paper argues that height might not only affect an individual's income but also utility from consumption. Higher caloric needs of tall individuals should result in higher consumption expenditures for food to satisfy these needs. Size specific products should result in lower product variety for sizes where aggregate demand is low, typically sizes for individuals in the tails of the height distribution. Introducing these two channels into a household's maximization problem we derive a labor supply equation that allows for an empirical test for the relevance of these two channels. We use the German Socio-Economic Panel Study to estimate this labor supply equation. Caloric needs do not have a significant effect on labor supply. Product choice, on the other hand, does increase labor supply significantly. This implies that purely focusing on income might not be optimal under the utilitarian framework for tax analysis.Die positive Korrelation zwischen Stundenlöhnen und Körpergröße, welche in einem höheren Arbeitsangebot großer Individuen resultiert, ist in der einschlägigen Literatur hinreichend dokumentiert. Gegeben die utilitaristische Sichtweise und die Annahme, die Körpergröße habe keinen weiteren Einfluss auf den individuellen Nutzen, spräche dies für eine Ausrichtung der Einkommensteuer an der Körpergröße. In diesem Papier wird argumentiert, dass die Körpergröße jedoch nicht nur das Einkommen, sondern über weitere Kanäle auch den Nutzen eines Individuums beeinflusst. Ein höherer Kalorienverbrauch großer Individuen sollte in höheren Ausgaben für Nahrungsmittel resultieren. Größenspezifische Produkte sollten zu einer geringeren Produktauswahl für Größen mit geringerer Nachfrage führen, typischerweise für solche am Rand der Körpergrößenverteilung. Durch Einführung dieser beiden Kanäle in das Nutzenmaximierungskalkül von Haushalten leiten wir eine Arbeitsangebotsfunktion her, welche einen empirischen Test auf die Relevanz der beiden Kanäle erlaubt. Wir nutzen das Deutsche Sozioökonomische Panel, um die hergeleitete Arbeitsangebotsfunktion zu schätzen. Für Unterschiede beim Kalorienverbrauch finden wir keinen signifikanten Effekt auf das Arbeitsangebot. Eine höhere Produktauswahl steigert das Arbeitsangebot hingegen signifikant. Dies impliziert, dass im Rahmen der Steueranalyse nach utilitaristischer Sichtweise eine ausschließliche Fokussierung auf das Einkommen nicht optimal ist