The Gauss-Kronecker curvature of minimal hypersurfaces in four-dimensional space forms

LetQ(4)( c) be a four-dimensional space form of constant curvature c. In this paper we show that the infimum of the absolute value of the Gauss-Kronecker curvature of a complete minimal hypersurface in Q(4)(c), c <= 0, whose Ricci curvature is bounded from below, is equal to zero. Further, we study the connected minimal hypersurfaces M(3) of a space form Q(4)( c) with constant Gauss-Kronecker curvature K. For the case c <= 0, we prove, by a local argument, that if K is constant, then K must be equal to zero. We also present a classification of complete minimal hypersurfaces of Q(4)( c) with K constant.

Minimal Lagrangian surfaces in the tangent bundle of a Riemannian surface

Given an oriented Riemannian surface (Sigma, g), its tangent bundle T Sigma enjoys a natural pseudo-Kahler structure, that is the combination of a complex structure 2, a pseudo-metric G with neutral signature and a symplectic structure Omega. We give a local classification of those surfaces of T Sigma which are both Lagrangian with respect to Omega and minimal with respect to G. We first show that if g is non-flat, the only such surfaces are affine normal bundles over geodesics. In the flat case there is, in contrast, a large set of Lagrangian minimal surfaces, which is described explicitly. As an application, we show that motions of surfaces in R(3) or R(1)(3) induce Hamiltonian motions of their normal congruences, which are Lagrangian surfaces in TS(2) or TH(2) respectively. We relate the area of the congruence to a second-order functional F = f root H(2) - K dA on the original surface. (C) 2010 Elsevier B.V. All rights reserved.

Lipid, fatty acid, protein, amino acid and ash contents in four Brazilian red algae species

Four species of marine benthic algae (Laurencia filiformis, L. intricata, Gracilaria domingensis and G. birdiae) that belong to the phylum Rhodophyta were collected in Espirito Santo State, Brazil and investigated concerning their biochemical composition (fatty acid, total lipid, soluble proteins, amino acid and ash). The total content of lipid (% dry weight) ranged from 1.1% to 6.2%: fatty acid from 0.7% to 1.0%: soluble protein from 4.6% to 18.3%, amino acid from 6.7% to 11.3% and ash from 22.5% to 38.4%. judging from their composition, the four species of algae appear to be potential sources of dietary proteins, amino acids, lipids and essential fatty acids for humans and animals. (C) 2009 Elsevier Ltd. All rights reserved.

A new member of the ribbon-helix-helix transcription factor superfamily from the plant pathogen Xanthomonas axonopodis pv. citri

XACb0070 is an uncharacterized protein coded by the two large plasmids isolated from Xanthomonas axonopodis pv. cirri, the agent of citrus canker and responsible for important economical losses in citrus world production. XACb0070 presents sequence homology only with other hypothetical proteins belonging to plant pathogens, none of which have their structure determined. The NMR-derived solution structure reveals this protein is a homodimer in which each monomer presents two domains with different structural and dynamic properties: a folded N-terminal domain with beta alpha alpha topology which mediates dimerization and a long disordered C-terminal tail. The folded domain shows high structural similarity to the ribbon-helix-helix transcriptional repressors, a family of DNA-binding proteins of conserved 3D fold but low sequence homology: indeed XACb0070 binds DNA. Primary sequence and fold comparison of XACb0070 with other proteins of the ribbon-helix-helix family together with examination of the genes in the vicinity of xacb0070 suggest the protein might be the component of a toxin-antitoxin system. (C) 2010 Elsevier Inc. All rights reserved.

Environmental formaldehyde analysis by active diffusive sampling with a bundle of polypropylene porous capillaries followed by capillary zone electrophoretic separation and contactless conductivity detection

Compared to other volatile carbonylic compounds present in outdoor air, formaldehyde (CH2O) is the most toxic, deserving more attention in terms of indoor and outdoor air quality legislation and control. The analytical determination of CH2O in air still presents challenges due to the low-level concentration (in the sub-ppb range) and its variation with sampling site and time. Of the many available analytical methods for carbonylic compounds, the most widespread one is the time consuming collection in cartridges impregnated with 2,4-dinitrophenylhydrazine followed by the analysis of the formed hydrazones by HPLC. The present work proposes the use of polypropylene hollow porous capillary fibers to achieve efficient CH2O collection. The Oxyphan (R) fiber (designed for blood oxygenation) was chosen for this purpose because it presents good mechanical resistance, high density of very fine pores and high ratio of collection area to volume of the acceptor fluid in the tube, all favorable for the development of air sampling apparatus. The collector device consists of a Teflon pipe inside of which a bundle of polypropylene microporous capillary membranes was introduced. While the acceptor passes at a low flow rate through the capillaries, the sampled air circulates around the fibers, impelled by a low flow membrane pump (of the type used for aquariums ventilation). The coupling of this sampling technique with the selective and quantitative determination of CH2O, in the form of hydroxymethanesulfonate (HMS) after derivatization with HSO3-, by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-(CD)-D-4) enabled the development of a complete analytical protocol for the CH2O evaluation in air. (C) 2008 Published by Elsevier B.V.

From Pettson and Findus to Festus and Mercury...and Back Again: A Comparison of Four Translations of Sven Nordqvist's Picture Books

In order to examine how children's literature might be translated, two different English translations of two Swedish picture books have been analyzed. The original Swedish books are Rävjakten and Pannkakstårtan by Sven Nordqvist. Rävjakten was translated as The Fox Hunt in 1988 and as The Fox Hunt in 2000. Pannkakstårtan was translated as Pancake Pie in 1985 and as The Birthday Cake in 1999. Literary translation in general, specific translation issues for children's literature, and trends in international English style have been considered. Analysis of the four texts has been made, with consideration given to the following areas: changes in illustrations, layout, or format; text changes; lexical choices; and retention, deletion, or modification of names and culturally specific references. The analysis revealed that the following tendencies were true for the later translations: foreignization of the text, word-for-word translation of the text, and a neutral international English variety.

"I'm not a box. There's more than four sides to me." : En kvalitativ textanalys av karaktären Kurt Hummel och den homosexuella stereotypen

Arbetet består av en närläsning av karaktären Kurt Hummel i tv-serien Glee med fokus på stereotyper för homosexuella män, och hur Kurt förhåller sig till dem stereotyperna. Studien är gjord utifrån ett queerteoretiskt perspektiv och visar att Kurt i viss mån framställs stereotypt i seriens tidigare avsnitt, men att han efter hand uppvisar ett djup och komplexitet som man inte ofta ser hos homosexuella karaktärer på tv.

Lifestyle and health status in a sample of Swedish women four years after pregnancy : a comparison of women with a history of normal pregnancy and women with a history of gestational diabetes mellitus

Background: Despite the recommendations to continue the regime of healthy food and physical activity (PA) postpartum for women with previous gestational diabetes mellitus (GDM), the scientific evidence reveals that these recommendations may not be complied to. This study compared lifestyle and health status in women whose pregnancy was complicated by GDM with women who had a normal pregnancy and delivery. Methods: The inclusion criteria were women with GDM (ICD-10: O24.4 A and O24.4B) and women with uncomplicated pregnancy and delivery in 2005 (ICD-10: O80.0). A random sample of women fulfilling the criteria (n = 882) were identified from the Swedish Medical Birth Register. A questionnaire was sent by mail to eligible women approximately four years after the pregnancy. A total of 444 women (50.8%) agreed to participate, 111 diagnosed with GDM in their pregnancy and 333 with normal pregnancy/ delivery. Results: Women with previous GDM were significantly older, reported higher body weight and less PA before the index pregnancy. No major differences between the groups were noticed regarding lifestyle at the follow-up. Overall, few participants fulfilled the national recommendations of PA and diet. At the follow-up, 19 participants had developed diabetes, all with previous GDM. Women with previous GDM reported significantly poorer self-rated health (SRH), higher level of sick-leave and more often using medication on regular basis. However, a history of GDM or having overt diabetes mellitus showed no association with poorer SRH in the multivariate analysis. Irregular eating habits, no regular PA, overweight/obesity, and regular use of medication were associated with poorer SRH in all participants. Conclusions: Suboptimal levels of PA, and fruit and vegetable consumption were found in a sample of women with a history of GDM as well as for women with normal pregnancy approximately four years after index pregnancy. Women with previous GDM seem to increase their PA after childbirth, but still they perform their PA at lower intensity than women with a history of normal pregnancy. Having GDM at index pregnancy or being diagnosed with overt diabetes mellitus at follow-up did not demonstrate associations with poorer SRH four years after delivery.