996 resultados para Brown, Thomas, 1778-1820.
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Cover title: The engraved portraits & fancy subjects painted by Thomas Gainsborough, R.A., and George Romney.
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Mode of access: Internet.
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The common brown leafhopper, Orosius orientalis (Matsumura) (Homoptera: Cicadellidae), previously described as Orosius argentatus (Evans), is an important vector of several viruses and phytoplasmas worldwide. In Australia, phytoplasmas vectored by O. orientalis cause a range of economically important diseases, including legume little leaf (Hutton & Grylls, 1956), tomato big bud (Osmelak, 1986), lucerne witches broom (Helson, 1951), potato purple top wilt (Harding & Teakle, 1985), and Australian lucerne yellows (Pilkington et al., 2004). Orosius orientalis also transmits Tobacco yellow dwarf virus (TYDV; genus Mastrevirus, family Geminiviridae) to beans, causing bean summer death disease (Ballantyne, 1968), and to tobacco, causing tobacco yellow dwarf disease (Hill, 1937, 1941). TYDV has only been recorded in Australia to date. Both diseases result in significant production and quality losses (Ballantyne, 1968; Thomas, 1979; Moran & Rodoni, 1999). Although direct damage caused by leafhopper feeding has been observed, it is relatively minor compared to the losses resulting from disease (P Tr E bicki, unpubl.).
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A density prediction model for juvenile brown shrimp (Farfantepenaeus aztecus) was developed by using three bottom types, five salinity zones, and four seasons to quantify patterns of habitat use in Galveston Bay, Texas. Sixteen years of quantitative density data were used. Bottom types were vegetated marsh edge, submerged aquatic vegetation, and shallow nonvegetated bottom. Multiple regression was used to develop density estimates, and the resultant formula was then coupled with a geographical information system (GIS) to provide a spatial mosaic (map) of predicted habitat use. Results indicated that juvenile brown shrimp (<100 mm) selected vegetated habitats in salinities of 15−25 ppt and that seagrasses were selected over marsh edge where they co-occurred. Our results provide a spatially resolved estimate of high-density areas that will help designate essential fish habitat (EFH) in Galveston Bay. In addition, using this modeling technique, we were able to provide an estimate of the overall population of juvenile brown shrimp (<100 mm) in shallow water habitats within the bay of approximately 1.3 billion. Furthermore, the geographic range of the model was assessed by plotting observed (actual) versus expected (model) brown shrimp densities in three other Texas bays. Similar habitat-use patterns were observed in all three bays—each having a coefficient of determination >0.50. These results indicate that this model may have a broader geographic application and is a plausible approach in refining current EFH designations for all Gulf of Mexico estuaries with similar geomorphological and hydrological characteristics.
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Polymorphic microsatellite DNA loci were used here in three studies, one on Salmo salar and two on S. trutta. In the case of S. salar, the survival of native fish and non-natives from a nearby catchment, and their hybrids, were compared in a freshwater common garden experiment and subsequently in ocean ranching, with parental assignment utilising microsatellites. Overall survival of non-natives was 35% of natives. This differential survival was mainly in the oceanic phase. These results imply a genetic basis and suggest local adaptation can occur in salmonids across relatively small geographic distances which may have important implications for the management of salmon populations. In the first case study with S trutta, the species was investigated throughout its spread as an invasive in Newfoundland, eastern Canada. Genetic investigation confirmed historical records that the majority of introductions were from a Scottish hatchery and provided a clear example of the structure of two expanding waves of spread along coasts, probably by natural straying of anadromous individuals, to the north and south of the point of human introduction. This study showed a clearer example of the genetic anatomy of an invasion than in previous studies with brown trout, and may have implications for the management of invasive species in general. Finally, the genetics of anadromous S. trutta from the Waterville catchment in south western Ireland were studied. Two significantly different population groupings, from tributaries in geographically distinct locations entering the largest lake in the catchment, were identified. These results were then used to assign very large rod caught sea trout individuals (so called “specimen” sea trout) back to region of origin, in a Genetic Stock Identification exercise. This suggested that the majority of these large sea trout originated from one of the two tributary groups. These results are relevant for the understanding of sea trout population dynamics and for the future management of this and other sea trout producing catchments. This thesis has demonstrated new insights into the population structuring of salmonids both between and within catchments. While these chapters look at the existence and scale of genetic variation from different angles, it might be concluded that the overarching message from this thesis should be to highlight the importance of maintaining genetic diversity in salmonid populations as vital for their long-term productivity and resilience.
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This article aims to reassess F. Scott Fitzgerald’s classic The Great Gatsby (1925), taking into consideration the myth-critical hypotheses of philosopher René Girard. Specifically, this essay will analyse the concepts of mimetic desire, resentment and reprisal violence as emotional components of myth, paying close attention to how the reinterpreted mythical pattern of the novel influences the depiction of such emotions as social traits of corruption. Finally, this article will challenge interpretations that have regarded Gatsby as a successful scapegoat-figure, examining instead how the mythical meanings and structures of the text stage an emotional crisis of frustrated desire and antagonism that ultimately offers no hope of communal restoration.
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The marine brown alga Halidrys siliquosa is known to produce compounds with antifouling activity against several marine bacteria. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of organic extracts obtained from the marine brown alga H. siliquosa against a focused panel of clinically relevant human pathogens commonly associated with biofilm-related infections. The partially fractionated methanolic extract obtained from H. siliquosa collected along the shores of Co. Donegal; Ireland; displayed antimicrobial activity against bacteria of the genus Staphylococcus; Streptococcus; Enterococcus; Pseudomonas; Stenotrophomonas; and Chromobacterium with MIC and MBC values ranging from 0.0391 to 5 mg/mL. Biofilms of S. aureus MRSA were found to be susceptible to the algal methanolic extract with MBEC values ranging from 1.25 mg/mL to 5 mg/mL respectively. Confocal laser scanning microscopy using LIVE/DEAD staining confirmed the antimicrobial nature of the antibiofilm activity observed using the MBEC assay. A bioassay-guided fractionation method was developed yielding 10 active fractions from which to perform purification and structural elucidation of clinically-relevant antibiofilm compounds.
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In 1858, a volume entitled Midnight Scenes and Social Photographs – being sketches of life in the streets, wynds and dens of the city of Glasgow was published under the pseudonym of ‘Shadow’ by Alexander Brown, a Glaswegian flâneur and reformer. Its frontispiece is an etching which depicts a theatre-like proscenium arch whose curtains have been withdrawn to reveal to the audience all the poverty, destitution and disorder that one was likely to find after dark in the insalubrious quarters of the city. At the extreme left-hand side, partly obscured by the curtain a silhouetted figure stands behind an unwieldy camera perched on a tripod. Distinctly unaffected by the mêlée, an arm is calmly raised and a finger precisely arched in the moment before the shutter is clicked and the scene committed to record. The volume, however, relies exclusively on textual descriptions to evoke the underside of the city and contains no photographs at all. Instead, the use of the word photograph in the title can be understood as a metaphor for detached scientific objectivity, a quality much celebrated by nineteenth-century reformers and investigators of social ills. As it happened, a decade after Shadow disappeared into the labyrinthine back-lands of Old Town Glasgow, he was followed there by a real photographer. In 1868, Thomas Annan was commissioned by the City Improvements Trust to take photographs of the Old Town in its last moments of existence before it was pulled down under a series of legislative acts. But perhaps paradoxically, given Shadow’s faith in the analytical properties of photography, Annan’s work seems to refute much of the material contained in Midnight Scenes and other similar tracts. Instead of the dens, shebeens, labyrinths and rowdy crowds described by Shadow, Annan’s depictions of the Old Town convey a static, calm environment, one which is often sparsely inhabited by a curious but apparently orderly population.
Taking account of the sensational tendencies of many reformists’ texts, this paper investigates the discrepancies between the two representations, focussing in particular on the constraints which operated on Annan during his commission. It argues that Annan’s compositions – which became very influential on other 19th century photographers of everyday life such as John Thomson or Jacob Riis – far from being dispassionate analytical works, emerged as a result of a matrix of factors which included: photographic and artistic precedents; Annan’s own predilections as a photographer; technological limitations; the nature of the commission from the City Improvements Trust and political climate in which it was given; the medieval urban fabric in which he had to operate; and, perhaps, most importantly, the identity of the Old Towns inhabitants themselves.
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Indenture regarding land sold by David Secord of St. Davids to George Shaw, Richard Woodruff, Timothy Street and Josiah Brown, all of Niagara Township and Reverend Henry Pope of York. The land includes part of Lot no. 90 in the Township of Niagara. September 5, 1820.
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UANL
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Este trabajo desarrolla un modelo de generaciones traslapadas con expectativa de vida endógena y capital humano. Recoge parte de la evidencia empírica acerca de la transición demográfica explicada por Notestein en 1945, donde variaciones en la longevidad de los individuos afectan positivamente el crecimiento económico de un país. El modelo establece que la falta de incentivos para invertir en salud estanca a una economía en una trampa de pobreza y muestra que incrementos en la productividad en el sector de producción de capital humano, al igual que cambios tecnológicos sesgados al uso intensivo del mismo, incrementan el producto de estado estacionario y pueden sacar a una economía de una trampa de pobreza.