424 research outputs found

    Silk Genes Support the Single Origin of Orb Webs

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    Mitochondrial differentiation, introgression and phylogeny of species in the Tegenaria atrica group (Araneae, Agelenidae)

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    The relationships between the three members of the Tegenaria atrica group (T. atrica, T. saeva and T. gigantea) were examined with DNA sequence data from mitochondrial CO1, 16S rRNA, tRNAleu(CUN) and ND1 genes. Members of this group of large house spiders have overlapping distributions in western Europe and hybridize with each other to a variable degree. The close relatedness of all three species was supported by all analyses. T. saeva and T. gigantea are more closely affiliated than either is to T. atrica. Haplotypes clearly assignable to T. gigantea were also present in many specimens of T. saeva suggesting asymmetrical introgression of mtDNA from T. gigantea into T. saeva. Molecular clock calibrations (CO1) suggest that deeper divisions within the genus Tegenaria may be in excess of 10 million years old, and that the evolutionary history of the T. atrica group has been moulded by Quaternary glacial-interglacial cycles

    Books

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    Human neurology The Human Central Nervous System: A Synopsis and Atlas. 3rd revised ed. Ed. by R. Nieuwenhuys, J. Voogd, C. H. R. van Huijzen. Pp. xii + 437. Illustrated. DM 85. Berlin: SpringerVerlag. 1988.Paediatric respiratory disorders Kendig's Disorders of the Respiratory Tract in Children. 5th ed. Ed. by Victor Chernick. Consulting ed. Edwin L. Kendig, jun. Pp. xxi + 1055. Philadelphia: WB Saunders. 1990.Maxillofacial imaging Maxillofacial Imaging. Ed. by A. M. Delbalso. pp. Vlll + 799. Illustrated. Kent: Harcourt Brace Jovanovich. 1990.Introduction to philosophy of medicine Philosophy of Medicine: An Introduction. Ed. by H. R. Wulff, S. A. Pedersen and R. Rosenberg. pp. xv + 222. £14,95. Oxford: Blackwell. 1990.Cataract management Management of Cataract in Primary Health Care Services. Pp. vi + 43. Illustrated. SFr. 15. Geneva: WHO. 1990.Family practice-management Family Practice Management. Ed. by G. J. and C. M. 1. Pistorius. Pp. 587. Illustrated. R99,50. Parow: Haurn/De Jager. J99O.Obstetrics and gynaecology Essential Obstetrics and Gynaecology. By E. Malcolm Symonds. pp. vi + 266. Illustrated. Edinburgh: Maskew Miller Longman.Surgical memoirs Surgical Roots and Branches. Ed. by R. Murley. Pp. x + 341. Illustrated. £18,50. Hamilton: Libriger Book Distribution. 1990.Survival in a hostile environment Staying Alive. Ed. by Ron Reid-Daly. Pp. ix + 259. Illustrated. R49,95. Rivonia: Ashami. 1990.Urolithiasis Urolithiasis: Medical and Surgical Reference. Ed. by M. 1. Resnick and C. Y. C. Pak. Pp. x + 375. Illustrated. R53,50. Kent: Harcoun Brace Jovanovich. 1990.Mental health in primary health care The Introduction of a Mental Health Component into Primary Health Care. pp. 1-59. SFr. 11,50. Geneva: WHO. 1990Tuberculosis in South Africa White Plague, Black Labor: Tuberculosis and the Political Economy of Health and Disease in South Africa. Ed. by Randall M. Packard. pp. xxii + 389. Illustrated. 40(cloth)and40 (cloth) and 15,95 (paperback). California: University of California Press. 1989.Medical research Research in Medicine:"A Guide to Writing a Thesis in the Medical Sciences. Ed. by G. Murrell, C. Huang and H. Ellis. PP: xii + 105. Illustrated. £19,50 (hIb) £7,50 (Plb). Cambridge: Cambridge University Press. 1990

    The flesh of painting: Caillebotte’s Modern Olympia

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    The language of putrefaction, often applied through a culinary analogy, appeared consistently in the critical reception of modern-life and Impressionist painting. For example, two critics used the term faisandé, referring to well-hung meat, to describe Manet’s nude figure of Olympia in 1865. The analogies that they posed between morgue bodies, female figures, meat, and fleshy paint material became central modes of denigrating Impressionist paintings of women in the ensuing decades. Gustave Caillebotte’s Veal in a Butcher’s Shop (c. 1882), depicting anthropomorphized, gendered, and sexualized animal flesh, can be considered in this context. In my reading, the painting enacts the critical responses to his colleagues’ figures, foregrounding the violent operations through which bodies might be reduced to meat, whether literal or metaphorical. In their comparisons to rotting flesh, nineteenth-century critics expressed a visceral reaction to works of art that Veal in a Butcher’s Shop demands

    Conjunction and Disjunction in Infectious Logics

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    In this paper we discuss the extent to which conjunction and disjunction can be rightfully regarded as such, in the context of infectious logics. Infectious logics are peculiar many-valued logics whose underlying algebra has an absorbing or infectious element, which is assigned to a compound formula whenever it is assigned to one of its components. To discuss these matters, we review the philosophical motivations for infectious logics due to Bochvar, Halldén, Fitting, Ferguson and Beall, noticing that none of them discusses our main question. This is why we finally turn to the analysis of the truth-conditions for conjunction and disjunction in infectious logics, employing the framework of plurivalent logics, as discussed by Priest. In doing so, we arrive at the interesting conclusion that —in the context of infectious logics— conjunction is conjunction, whereas disjunction is not disjunction

    Structural and functional characterization of Sticholysin III: A newly discovered actinoporin within the venom of the sea anemone Stichodactyla helianthus.

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    Actinoporins are a family of pore-forming toxins produced by sea anemones as part of their venomous cocktail. These proteins remain soluble and stably folded in aqueous solution, but when interacting with sphingomyelin-containing lipid membranes, they become integral oligomeric membrane structures that form a pore permeable to cations, which leads to cell death by osmotic shock. Actinoporins appear as multigenic families within the genome of sea anemones: several genes encoding very similar actinoporins are detected within the same species. The Caribbean Sea anemone Stichodactyla helianthus produces three actinoporins (sticholysins I, II and III; StnI, StnII and StnIII) that differ in their toxic potency. For example, StnII is about four-fold more effective than StnI against sheep erythrocytes in causing hemolysis, and both show synergy. However, StnIII, recently discovered in the S. helianthus transcriptome, has not been characterized so far. Here we describe StnIII’s spectroscopic and functional properties and show its potential to interact with the other Stns. StnIII seems to maintain the well-preserved fold of all actinoporins, characterized by a high content of β-sheet, but it is significantly less thermostable. Its functional characterization shows that the critical concentration needed to form active pores is higher than for either StnI or StnII, suggesting differences in behavior when oligomerizing on membrane surfaces. Our results show that StnIII is an interesting and unexpected piece in the puzzle of how this Caribbean Sea anemone species modulates its venomous activity

    Dialetheism in Action: A New Strategy for Solving the Equal Validity Paradox

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    This paper starts from the Equal Validity Paradox, a paradoxical argument connected to the so-called phenomenon of faultless disagreement. It is argued that there are at least six strategies for solving the paradox. After presenting the first five strategies and their main problems, the paper focuses on the sixth strategy which rejects the assumption that every proposition cannot be both true a false. Dialetheism is the natural candidate for developing strategy six. After presenting strategy six in detail, we formulate a normative problem for the dialetheist and offer a tentative solution to it. We then elaborate further considerations connecting strategy six to pluralism about truth and logic. Even if strategy six is a hard path to take, its scrutiny highlights some important points on truth, logic and the norms for acceptance and rejection

    Gene content evolution in the arthropods

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    Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity
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