A mitochondrial species identification assay for Australian blacktip sharks (Carcharhinus tilstoni, C. limbatus and C. amblyrhynchoides) using real-time PCR and high-resolution melt analysis

Tropical Australian shark fisheries target two morphologically indistinguishable blacktip sharks, the Australian blacktip (Carcharhinus tilstoni) and the common blacktip (C. limbatus). Their relative contributions to northern and eastern Australian coastal fisheries are unclear because of species identification difficulties. The two species differ in their number of precaudal vertebrae, which is difficult and time consuming to obtain in the field. But, the two species can be distinguished genetically with diagnostic mutations in their mitochondrial DNA ND4 gene. A third closely related sister species, the graceful shark C. amblyrhynchoides, can also be distinguished by species-specific mutations in this gene. DNA sequencing is an effective diagnostic tool, but is relatively expensive and time consuming. In contrast, real-time high-resolution melt (HRM) PCR assays are rapid and relatively inexpensive. These assays amplify regions of DNA with species-specific genetic mutations that result in PCR products with unique melt profiles. A real-time HRM PCR species-diagnostic assay (RT-HRM-PCR) has been developed based on the mtDNA ND4 gene for rapid typing of C. tilstoni, C. limbatus and C. amblyrhynchoides. The assay was developed using ND4 sequences from 66 C. tilstoni, 33. C. limbatus and five C. amblyrhynchoides collected from Indonesia and Australian states and territories; Western Australia, the Northern Territory, Queensland and New South Wales. The assay was shown to be 100% accurate on 160 unknown blacktip shark tissue samples by full mtDNA ND4 sequencing.

LAS GRIETAS DE LA CIUDAD CAPITALISTA Entrevista con David Harvey

David Harvey es uno de los investigadores de la ciudad capitalista más renombrados de la actualidad. Geógrafo de formación, Harvey ha desarrollado el grueso de su carrera profesional en Estados Unidos, donde actualmente enseña Geografía y Estudios Urbanos en City University of New York tras haber sido durante más de treinta años profesor en la Johns Hopkins University de Baltimore. El principal e indiscutido mérito de la obra de Harvey reside en su fructífera fusión de geografía y marxismo con la que ha logrado ampliar, profundizar y enriquecer al mismo tiempo ambas disciplinas. En los últimos tiempos su atención se ha centrado en el estudio espacial de las nuevas formas de imperialismo.

A PRESENÇA DA SOCIOBIOLOGIA EM ESPAÇO DE ESPERANÇA, DE DAVID HARVEY

Este presente trabalho pretende estabelecer uma crítica as apropriações que o geógrafo inglês David Harvey faz da sociobiologia. Para tanto, opta-se por uma análise comparativa entre as propostas apresentadas pelo geógrafo e as resoluções apontadas por Marx sobre as especificidades do ser social. Em seu livro Espaço de Esperança (2004), Harvey expressa a importância de produção de uma base epistemológica que concilie o físico com o social, recorrendo a sociobiologia, de Edward Wilson, como modelo, muito controverso, para conceber uma “ciência única”. Para balizar os fundamentos e pressupostos de sua análise, Harvey estabelece um dialogo entre Wilson e Marx com a finalidade de demonstrar certos traços de evolucionismo no filosofo alemão. Nesse intuito, Harvey recai numa certa naturalização de relações, especificamente, sociais, obnubilando o salto ontológico entre o ser orgânico, da natureza, e o ser social. O geógrafo aposta, portanto, no caminho reverso do de Marx, que pretende demonstrar, ao longo de toda sua extensa obra, as especificidades do humano e do modo de produção e reprodução capitalista.

A PRESENÇA DA SOCIOBIOLOGIA EM ESPAÇO DE ESPERANÇA, DE DAVID HARVEY

Este presente trabalho pretende estabelecer uma crítica as apropriações que o geógrafo inglês David Harvey faz da sociobiologia. Para tanto, opta-se por uma análise comparativa entre as propostas apresentadas pelo geógrafo e as resoluções apontadas por Marx sobre as especificidades do ser social. Em seu livro Espaço de Esperança (2004), Harvey expressa a importância de produção de uma base epistemológica que concilie o físico com o social, recorrendo a sociobiologia, de Edward Wilson, como modelo, muito controverso, para conceber uma “ciência única”. Para balizar os fundamentos e pressupostos de sua análise, Harvey estabelece um dialogo entre Wilson e Marx com a finalidade de demonstrar certos traços de evolucionismo no filosofo alemão. Nesse intuito, Harvey recai numa certa naturalização de relações, especificamente, sociais, obnubilando o salto ontológico entre o ser orgânico, da natureza, e o ser social. O geógrafo aposta, portanto, no caminho reverso do de Marx, que pretende demonstrar, ao longo de toda sua extensa obra, as especificidades do humano e do modo de produção e reprodução capitalista.

The politics of literacy in David Almond and Dave McKean’s "The Savage" (2008)

Competency in language and literacy are central to contemporary debates about education in Anglophone nations around the world. This paper suggests that such debates are informing not just educational policy but children’s literature itself as can be seen in Almond and McKean’s The Savage. This hybrid text combines prose and graphic narrative and narration in order to tell the story of Blue, a young British boy negotiating his identity in the aftermath of his father's death. While foregrounding a narrative of ideal masculinity, The Savage enacts and privileges a formal and thematic ideal of literacy as index of individual agency and development. Almond and McKean produce a politicised understanding of language and literacy that simultaneously positions The Savage in a textual tradition of socio-culturally disenfranchised youth, and intervenes in that tradition to (perhaps ironically) affirm the very conditions previously critiqued by that very tradition. Where earlier authors such as Barry Hines sought to challenge normative accounts of language and literacy in order to indict educational policy and praxes, Almond and McKean work to naturalise the very logics of education and agency by which their protagonist has been disenfranchised. In doing so, The Savage exemplifies current approaches to education which claim to value social and cultural diversity while imposing national standardised testing predicated on assumptions about the legitimacy of uniform standards and definitions of literacy.

Influence of historic land use change on the biosphere-atmosphere-exchange of C and N trace gases in the humid, subtropical region of Queensland

Increases in atmospheric concentrations of the greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) due to human activities have been linked to climate change. GHG emissions from land use change and agriculture have been identified as significant contributors to both Australia’s and the global GHG budget. This is expected to increase over the coming decades as rates of agriculture intensification and land use change accelerate to support population growth and food production. Limited data exists on CO2, CH4 and N2O trace gas fluxes from subtropical or tropical soils and land uses. To develop effective mitigation strategies a full global warming potential (GWP) accounting methodology is required that includes emissions of the three primary greenhouse gases. Mitigation strategies that focus on one gas only can inadvertently increase emissions of another. For this reason, detailed inventories of GHGs from soils and vegetation under individual land uses are urgently required for subtropical Australia. This study aimed to quantify GHG emissions over two consecutive years from three major land uses; a well-established, unfertilized subtropical grass-legume pasture, a 30 year (lychee) orchard and a remnant subtropical Gallery rainforest, all located near Mooloolah, Queensland. GHG fluxes were measured using a combination of high resolution automated sampling, coarser spatial manual sampling and laboratory incubations. Comparison between the land uses revealed that land use change can have a substantial impact on the GWP on a landscape long after the deforestation event. The conversion of rainforest to agricultural land resulted in as much as a 17 fold increase in GWP, from 251 kg CO2 eq. ha-1 yr-1 in the rainforest to 889 kg CO2 eq. ha-1 yr-1 in the pasture to 2538 kg CO2 eq. ha-1 yr-1 in the lychee plantation. This increase resulted from altered N cycling and a reduction in the aerobic capacity of the soil in the pasture and lychee systems, enhancing denitrification and nitrification events, and reducing atmospheric CH4 uptake in the soil. High infiltration, drainage and subsequent soil aeration under the rainforest limited N2O loss, as well as promoting CH4 uptake of 11.2 g CH4-C ha-1 day-1. This was among the highest reported for rainforest systems, indicating that aerated subtropical rainforests can act as substantial sink of CH4. Interannual climatic variation resulted in significantly higher N2O emission from the pasture during 2008 (5.7 g N2O-N ha day) compared to 2007 (3.9 g N2O-N ha day), despite receiving nearly 500 mm less rainfall. Nitrous oxide emissions from the pasture were highest during the summer months and were highly episodic, related more to the magnitude and distribution of rain events rather than soil moisture alone. Mean N2O emissions from the lychee plantation increased from an average of 4.0 g N2O-N ha-1 day-1, to 19.8 g N2O-N ha-1 day-1 following a split application of N fertilizer (560 kg N ha-1, equivalent to 1 kg N tree-1). The timing of the split application was found to be critical to N2O emissions, with over twice as much lost following an application in spring (emission factor (EF): 1.79%) compared to autumn (EF: 0.91%). This was attributed to the hot and moist climatic conditions and a reduction in plant N uptake during the spring creating conditions conducive to N2O loss. These findings demonstrate that land use change in subtropical Australia can be a significant source of GHGs. Moreover, the study shows that modifying the timing of fertilizer application can be an efficient way of reducing GHG emissions from subtropical horticulture.