Blueprint for a high-performance biomaterial: full-length spider dragline silk genes.

Spider dragline (major ampullate) silk outperforms virtually all other natural and manmade materials in terms of tensile strength and toughness. For this reason, the mass-production of artificial spider silks through transgenic technologies has been a major goal of biomimetics research. Although all known arthropod silk proteins are extremely large (>200 kiloDaltons), recombinant spider silks have been designed from short and incomplete cDNAs, the only available sequences. Here we describe the first full-length spider silk gene sequences and their flanking regions. These genes encode the MaSp1 and MaSp2 proteins that compose the black widow's high-performance dragline silk. Each gene includes a single enormous exon (>9000 base pairs) that translates into a highly repetitive polypeptide. Patterns of variation among sequence repeats at the amino acid and nucleotide levels indicate that the interaction of selection, intergenic recombination, and intragenic recombination governs the evolution of these highly unusual, modular proteins. Phylogenetic footprinting revealed putative regulatory elements in non-coding flanking sequences. Conservation of both upstream and downstream flanking sequences was especially striking between the two paralogous black widow major ampullate silk genes. Because these genes are co-expressed within the same silk gland, there may have been selection for similarity in regulatory regions. Our new data provide complete templates for synthesis of recombinant silk proteins that significantly improve the degree to which artificial silks mimic natural spider dragline fibers

Allergic fungal sinusitis secondary to Acremonium species causing unilateral visual loss

A wide range of fungi have been associated with Allergic Fungal Sinusitis (AFS) or Eosinophilic fungal rhinosinusitis ( EFRS) as it is known in some institutions. To our knowledge, this is the first reported case of aggressive, invasive AFS due to Acremonium species occurring in an immunocompetent patient and leading to unilateral visual loss. Literature on AFS is reviewed.Key words: Eosinophilic fungal rhinosinusitis, Allergic fungal sinusitis, Acremonium species, visual loss

Books

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) 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

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

Phylogeography of a successful aerial disperser: the golden orb spider Nephila on Indian Ocean islands

Abstract Background The origin and diversification patterns of lineages across the Indian Ocean islands are varied due to the interplay of the complex geographic and geologic island histories, the varying dispersal abilities of biotas, and the proximity to major continental landmasses. Our aim was to reconstruct phylogeographic history of the giant orbweaving spider (Nephila) on western Indian Ocean islands (Madagascar, Mayotte, Réunion, Mauritius, Rodrigues), to test its origin and route of dispersal, and to examine the consequences of good dispersal abilities for colonization and diversification, in comparison with related spiders (Nephilengys) inhabiting the same islands, and with other organisms known for over water dispersal. We used mitochondrial (COI) and nuclear (ITS2) markers to examine phylogenetic and population genetic patterns in Nephila populations and species. We employed Bayesian and parsimony methods to reconstruct phylogenies and haplotype networks, respectively, and calculated genetic distances, fixation indices, and estimated clade ages under a relaxed clock model. Results Our results suggest an African origin of Madagascar Nephila inaurata populations via Cenozoic dispersal, and the colonization of the Mascarene islands from Madagascar. We find evidence of gene flow across Madagascar and Comoros. The Mascarene islands share a common 'ancestral' COI haplotype closely related to those found on Madagascar, but itself absent, or as yet unsampled, from Madagascar. Each island has one or more unique haplotypes related to the ancestral Mascarene haplotype. The Indian Ocean N. inaurata are genetically distinct from the African populations. Conclusions Nephila spiders colonized Madagascar from Africa about 2.5 (0.6-5.3) Ma. Our results are consistent with subsequent, recent and rapid, colonization of all three Mascarene islands. On each island, however, we detected unique haplotypes, consistent with a limited gene flow among the islands subsequent to colonization, a scenario that might be referred to as speciation in progress. However, due to relatively small sample sizes, we cannot rule out that we simply failed to collect Mascarene haplotypes on Madagascar, a scenario that might imply human mediated dispersal. Nonetheless, the former interpretation better fits the available data and results in a pattern similar to the related Nephilengys. Nephilengys, however, shows higher genetic divergences with diversification on more remote islands. That the better disperser of the two lineages, Nephila, has colonized more islands but failed to diversify, demonstrates how dispersal ability can shape both the patterns of colonization and formation of species across archipelagos.</p

Conjunction and Disjunction in Infectious Logics

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

Gene content evolution in the arthropods

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

Conservation of a pH-sensitive structure in the C-terminal region of spider silk extends across the entire silk gene family

Spiders produce multiple silks with different physical properties that allow them to occupy a diverse range of ecological niches, including the underwater environment. Despite this functional diversity, past molecular analyses show a high degree of amino acid sequence similarity between C-terminal regions of silk genes that appear to be independent of the physical properties of the resulting silks; instead, this domain is crucial to the formation of silk fibres. Here we present an analysis of the C-terminal domain of all known types of spider silk and include silk sequences from the spider Argyroneta aquatica, which spins the majority of its silk underwater. Our work indicates that spiders have retained a highly conserved mechanism of silk assembly, despite the extraordinary diversification of species, silk types and applications of silk over 350 million years. Sequence analysis of the silk C-terminal domain across the entire gene family shows the conservation of two uncommon amino acids that are implicated in the formation of a salt bridge, a functional bond essential to protein assembly. This conservation extends to the novel sequences isolated from A. aquatica. This finding is relevant to research regarding the artificial synthesis of spider silk, suggesting that synthesis of all silk types will be possible using a single process

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

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

Structural Characterization of Minor Ampullate Spidroin Domains and Their Distinct Roles in Fibroin Solubility and Fiber Formation

10.1371/journal.pone.0056142PLoS ONE82