Weak helix submanifolds of euclidean spaces

It is shown that there exist nonstrong weak 2-helix surfaces of R

Constant Angle Surfaces in \H^2\times \R

In this paper we classify constant angle surfaces in \H^2\times\R, where \H^2 is the hyperbolic plane.Comment: 9 Latex page

On certain surfaces in the Euclidean space E3{\mathbb{E}}^3

In the present paper we classify all surfaces in \E^3 with a canonical principal direction. Examples of these type of surfaces are constructed. We prove that the only minimal surface with a canonical principal direction in the Euclidean space ${\mathbb{E}}^3$ is the catenoid.Comment: 13 Latex page

Modeling the Background for Incremental and Weakly-Supervised Semantic Segmentation

Deep neural networks have enabled major progresses in semantic segmentation. However, even the most advanced neural architectures suffer from important limitations. First, they are vulnerable to catastrophic forgetting, i.e. they perform poorly when they are required to incrementally update their model as new classes are available. Second, they rely on large amount of pixel-level annotations to produce accurate segmentation maps. To tackle these issues, we introduce a novel incremental class learning approach for semantic segmentation taking into account a peculiar aspect of this task: since each training step provides annotation only for a subset of all possible classes, pixels of the background class exhibit a semantic shift. Therefore, we revisit the traditional distillation paradigm by designing novel loss terms which explicitly account for the background shift. Additionally, we introduce a novel strategy to initialize classifiers parameters at each step in order to prevent biased predictions toward the background class. Finally, we demonstrate that our approach can be extended to point- and scribble-based weakly supervised segmentation, modeling the partial annotations to create priors for unlabeled pixels. We demonstrate the effectiveness of our approach with an extensive evaluation on the Pascal-VOC, ADE20K, and Cityscapes datasets, significantly outperforming state-of-the-art methods

The developmentally regulated avian Ch21 lipocalin is an extracellular fatty acid-binding protein.

Ch21, a developmentally regulated extracellular protein expressed in chick embryos and in cultured chondrocytes, was expressed in the baculovirus system, and the recombinant protein was purified to homogeneity by gel-filtration chromatography. Separation of two isoforms was achieved on an ion-exchange column. Previous work had shown that Ch21 belongs to the superfamily of lipocalins, which are transport proteins for small hydrophobic molecules. Studies were performed to identify the Ch21 ligand. By analysis of recombinant Ch21 on native polyacrylamide gel electrophoresis and by Lipidex assay, the binding of fatty acid to the protein was shown and a preferential binding of long-chain unsaturated fatty acids was observed. Both isoforms had the same behavior. The binding was saturable. Stoichiometry was about 0.7 mol of ligand/mol of protein. The protein binds the ligand in its monomeric form. Calculated dissociation constants were 2 X 10(-7) M for unsaturated fatty acids and 5 X 10(-7) M for stearic acid. The binding was specific; other hydrophobic molecules, as retinoic acid, progesterone, prostaglandins, and long-chain alcohols and aldehydes did not bind to the protein. Short-chain fatty acids did not bind to the protein. Ch21, also present in chicken serum, represents the first extracellular protein able to selectively bind and transport fatty acid in extracellular fluids and serum. We propose to rename the Ch21 protein as extracellular fatty acid-binding protein (Ex-FABP)

The vasa regulatory region mediates germline expression and maternal transmission of proteins in the malaria mosquito Anopheles gambiae: a versatile tool for genetic control strategies

<p>Abstract</p> <p>Background</p> <p>Germline specific promoters are an essential component of potential vector control strategies which function by genetic drive, however suitable promoters are not currently available for the main human malaria vector <it>Anopheles gambiae</it>.</p> <p>Results</p> <p>We have identified the <it>Anopheles gambiae vasa</it>-like gene and found its expression to be specifically localized to both the male and female gonads in adult mosquitoes. We have functionally characterised using transgenic reporter lines the regulatory regions required for driving transgene expression in a pattern mirroring that of the endogenous <it>vasa </it>locus. Two reporter constructs indicate the existence of distinct <it>vasa </it>regulatory elements within the 5' untranslated regions responsible not only for the spatial and temporal but also for the sex specific germline expression. <it>vasa </it>driven eGFP expression in the ovary of heterozygous mosquitoes resulted in the progressive accumulation of maternal protein and transcript in developing oocytes that were then detectable in all embryos and neonatal larvae.</p> <p>Conclusion</p> <p>We have characterized the <it>vasa </it>regulatory regions that are not only suited to drive transgenes in the early germline of both sexes but could also be utilized to manipulate the zygotic genome of developing embryos via maternal deposition of active molecules. We have used computational models to show that a homing endonuclease-based gene drive system can function in the presence of maternal deposition and describe a novel non-invasive control strategy based on early <it>vasa </it>driven homing endonuclease expression.</p

On weak r-Helix submanifolds

In this paper, we investigate special curves on a weak r-helix submanifold in Euclidean n-space E^{n}. Also, we give the important relations between weak r-helix submanifolds and the special curves such as line of curvature, asymptotic curve and helix line.Comment: arXiv admin note: text overlap with arXiv:1203.160

Sexually Antagonistic Selection in Human Male Homosexuality

Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling ‘Darwinian paradox’. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness), accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait

A Modifier Screen for Bazooka/PAR-3 Interacting Genes in the Drosophila Embryo Epithelium

The development and homeostasis of multicellular organisms depends on sheets of epithelial cells. Bazooka (Baz; PAR-3) localizes to the apical circumference of epithelial cells and is a key hub in the protein interaction network regulating epithelial structure. We sought to identify additional proteins that function with Baz to regulate epithelial structure in the Drosophila embryo.The baz zygotic mutant cuticle phenotype could be dominantly enhanced by loss of known interaction partners. To identify additional enhancers, we screened molecularly defined chromosome 2 and 3 deficiencies. 37 deficiencies acted as strong dominant enhancers. Using deficiency mapping, bioinformatics, and available single gene mutations, we identified 17 interacting genes encoding known and predicted polarity, cytoskeletal, transmembrane, trafficking and signaling proteins. For each gene, their loss of function enhanced adherens junction defects in zygotic baz mutants during early embryogenesis. To further evaluate involvement in epithelial polarity, we generated GFP fusion proteins for 15 of the genes which had not been found to localize to the apical domain previously. We found that GFP fusion proteins for Drosophila ASAP, Arf79F, CG11210, Septin 5 and Sds22 could be recruited to the apical circumference of epithelial cells. Nine of the other proteins showed various intracellular distributions, and one was not detected.Our enhancer screen identified 17 genes that function with Baz to regulate epithelial structure in the Drosophila embryo. Our secondary localization screen indicated that some of the proteins may affect epithelial cell polarity by acting at the apical cell cortex while others may act through intracellular processes. For 13 of the 17 genes, this is the first report of a link to baz or the regulation of epithelial structure