390 research outputs found

    British Sikhs in complementary schooling: the role of heritage language proficiency and ‘culture learning’ in ethnic identity and bicultural adaptation

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    While the debate regarding bilingual benefits persists within the cognitive sciences, education research has documented various functions that heritage languages (HL) serve their speakers through bicultural adaptation. The present study adopted a mixed-methods approach to gauge HL proficiency and use, cultural participation and ethnic and mainstream identities, and to examine multiple perspectives on HL learning with complementary schooling (CS) among British Sikhs. Seventy-four 6- to 15-year-olds completed scales for perceived oral and literate abilities, language use across contexts, British and Sikh identifications, and participation in cultural activities. Children filled in open-ended items, while parents and teachers discussed in interviews and focus groups, their motivations for HL learning and CS experiences. The majority of children self-reported ‘good’ proficiency, which differed between generations as impacted by home use and was associated with cultural participation and Sikh identification. Most children referred to practical utility while most parents regarded culture retention as the dominant motivation for HL learning. Teachers discussed how teaching beyond the second generation and language shifts presented both challenges and opportunities. Still, all parties corroborated on the pertinence of HL maintenance as facilitated by CS through ‘culture learning’ towards a strong ethnic identity and bicultural adaptation

    Epidemiological Characteristics of Poliomyelitis During the 21st Century (2000-2013)

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    Poliovirus is the pathogenic agent of paralytic poliomyelitis that belongs to the picornaviridae family. Poliomyelitis has an extended history dating over to the Egyptian eighteenth dynasty. It was recognized as distinct disease in the late nineteenth century when the world was ravaged by large number of outbreaks and epidemics in many countries. Paralytic Polio, the rarest but the most severe form of the disease, is characterized by acute flaccid paralysis of any or rarely both of the limbs. Increasing epidemics during the late 19th and 20th centuries lead to the initiation of a worldwide global effort for polio eradication in 1988, super headed by WHO and various other organizations. The launch of Global Polio Eradication Initiative together with the introduction of two polio vaccines resulted in 99% reduction of wild poliovirus cases worldwide while the total number of polio-endemic countries dropped from 24 countries in the year 2000 to only three countries in 2012; Afghanistan, Nigeria and Pakistan. This review will focus on the general biology of poliovirus, some historic and geographic epidemiological aspects of poliomyelitis eradication during the year 2000-2012 and also on the major failing factors associated with the efficiency of the vaccines to eradicate polio in Pakistan

    Water use and water availability constraints to decarbonised electricity systems

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    Analysis of numerous low carbon electricity strategies have been shown to have very divergent water requirements, normally needed for cooling of thermoelectric power stations. Our regional river-basin scale analysis of water use for future UK electricity strategies shows that, whilst in the majority of cases freshwater use is expected to decline, pathways with high levels of carbon capture and storage (CCS) will result in significantly elevated and concentrated water demands in a few key river basins. Furthermore, these growing demands are compared to both current water availability, and our expected regional water availability under the impacts of climate change. We identify key freshwater constraints to electricity strategies with high levels of CCS and show how these risks may be mitigated with higher levels of hybrid cooling and alternative cooling water sources

    The implications of ambitious decarbonisation of heat and road transport for Britain’s net zero carbon energy systems

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    Decarbonisation of heating and road transport are regarded as necessary but very challenging steps on the pathway to net zero carbon emissions. Assessing the most efficient routes to decarbonise these sectors requires an integrated view of energy and road transport systems. Here we describe how a national gas and electricity transmission network model was extended to represent multiple local energy systems and coupled with a national energy demand and road transport model. The integrated models were applied to assess a range of technologies and policies for heating and transport where the UK’s 2050 net zero carbon emissions target is met. Overall, annual primary energy use is projected to reduce by between 25% and 50% by 2050 compared to 2015, due to ambitious efficiency improvements within homes and vehicles. However, both annual and peak electricity demands in 2050 are more than double compared with 2015. Managed electric vehicle charging could save 14TWh/year in gas-fired power generation at peak times, and associated emissions, whilst vehicle-to-grid services could provide 10GW of electricity supply during peak hours. Together, managed vehicle charging, and vehicle-to-grid supplies could result in a 16% reduction in total annual energy costs. The provision of fast public charging facilities could reduce peak electricity demand by 17GW and save an estimated £650 million annually. Although using hydrogen for heating and transport spreads the hydrogen network costs between homeowners and motorists, it is still estimated to be more costly overall compared to an all-electric scenario. Bio-energy electricity generation plants with carbon capture and storage are required to drive overall energy system emissions to net zero, utilisation of which is lowest when heating is electrified, and road transport consists of a mix of electric and hydrogen fuel-cell vehicles. The analysis demonstrates the need for an integrated systems approach to energy and transport policies and for coordination between national and local governments

    Vulnerability assessment of the European natural gas supply

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    As indigenous natural gas reserves within the European Union (EU) decline, higher gas imports are expected in order to meet future EU gas demand. Natural gas will be transported across considerable distances from regions of gas reserves to European consumers. This raises security of gas supply concerns especially for EU countries that depend heavily on a single supply source or major transit route. A linear programming model of the European gas supplies was developed and used to investigate the impact of loss of the Ukraine transit capacity on gas supply from Russia to Europe. Two demand scenarios – that is a reference case and a high demand case in the winter of 2014/2015 were investigated. The results have shown that gas flows on interconnectors and from storage and liquefied natural gas import terminals compensated for the supply shortfall. Furthermore, to mitigate the effect of the supply shortage, the impact of increasing the capacities of selected pipelines within the EU was compared against increasing the maximum storage withdrawal rates in southeast Europe. Higher storage withdrawal rates achieved lower demand curtailment than the additional interconnector capacity in both scenarios

    A case of serendipity*

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    An account is given of how a sensitive bioassay system for measurement of the neurotransmitter acetylcholine serendipitously led to the identification of adenosine triphosphate (ATP) released in vitro from active skeletal muscle. Subsequent application of the identification procedures to exercising human muscle in vivo, cardiac muscle cells in vitro, and human erythrocytes exposed to hypoxia gave rise to the general concept of ATP as a molecule that could influence cell function from the extracellular direction. Mechanisms of ATP release from cells in terms of “trigger” events such as mechanical distortion of the membrane, depolarization of the membrane, and exposure to hypoxia are discussed. Potential therapeutic uses of extracellular ATP in cancer therapy, radiation therapy, and a possible influence upon aging are discussed. Possible roles (distant and local) of extracellular ATP released from muscle during whole body exercise are discussed

    Correlations Between Life-Detection Techniques and Implications for Sampling Site Selection in Planetary Analog Missions

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    We conducted an analog sampling expedition under simulated mission constraints to areas dominated by basaltic tephra of the Eldfell and Fimmvorouhals lava fields (Iceland). Sites were selected to be homogeneous at a coarse remote sensing resolution (10-100m) in apparent color, morphology, moisture, and grain size, with best-effort realism in numbers of locations and replicates. Three different biomarker assays (counting of nucleic-acid-stained cells via fluorescent microscopy, a luciferin/luciferase assay for adenosine triphosphate, and quantitative polymerase chain reaction (qPCR) to detect DNA associated with bacteria, archaea, and fungi) were characterized at four nested spatial scales (1m, 10m, 100m, and >1km) by using five common metrics for sample site representativeness (sample mean variance, group F tests, pairwise t tests, and the distribution-free rank sum H and u tests). Correlations between all assays were characterized with Spearman's rank test. The bioluminescence assay showed the most variance across the sites, followed by qPCR for bacterial and archaeal DNA; these results could not be considered representative at the finest resolution tested (1m). Cell concentration and fungal DNA also had significant local variation, but they were homogeneous over scales of >1km. These results show that the selection of life detection assays and the number, distribution, and location of sampling sites in a low biomass environment with limited a priori characterization can yield both contrasting and complementary results, and that their interdependence must be given due consideration to maximize science return in future biomarker sampling expeditions. Key Words: AstrobiologyBiodiversityMicrobiologyIcelandPlanetary explorationMars mission simulationBiomarker. Astrobiology 17, 1009-1021

    A genome-wide expression analysis identifies a network of EpCAM-induced cell cycle regulators

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    Expression of the epithelial cell adhesion molecule EpCAM is upregulated in a variety of carcinomas. This antigen is therefore explored in tumour diagnosis, and clinical trials have been initiated to examine EpCAM-based therapies. Notably, the possible intracellular effects and signalling pathways triggered by EpCAM-specific antibodies are unknown. Here, we show treatment of the mouse lung carcinoma cell line A2C12, of the human lung carcinoma cell line A549 and the human colorectal cell line Caco-2 with the monoclonal EpCAM antibody G8.8 to cause dose dependently an increase in cell proliferation, as determined by the MTS and the 5′-bromo-2′-deoxyuridine (BrdU) labelling assay. Furthermore, a genome-wide approach identified networks of regulated genes, most notably cell cycle regulators, upon treatment with an EpCAM-specific antibody. Indeed, changes in the expression of cell cycle regulators agreed well with the BrdU labelling data, and an analysis of differentially expressed genes revealed the processes with the strongest over-representation of modulated genes, for example, cell cycle, cell death, cellular growth and proliferation, and cancer. These data suggest that EpCAM is involved in signal transduction triggering several intracellular signalling pathways. Knowing EpCAM signalling pathways might lead to a reassessment of EpCAM-based therapies
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