614 research outputs found

    Regulating pacific seasonal labour in Australia

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    In 2008 the Australian government announced a new labour mobility scheme for Pacific workers, with the objectives of meeting seasonal demand for low-skilled labour in the horticulture industry and promoting economic development in Pacific Island countries. Modelled on New Zealand's Recognized Seasonal Employer scheme, it is a significant departure from Australia's long-standing preference for permanent migration that is non-discriminatory with respect to the country of origin. Any temporary migration program that draws a workforce from developing countries has the potential to exploit vulnerable foreign workers, but if Australia's pilot program is to be a success in the long term, it is imperative that seasonal workers from the Pacific are not exposed to that danger. This article examines the many layers of regulation that have been introduced to protect Pacific workers from exploitation, including bilateral intergovernmental agreements, supervision by government departments and use of external advisory bodies. In addition, Australia's regulatory framework governing workplace relations imposes a range of worker protections through equality laws, occupational health and safety principles, dispute settlement procedures and trade union involvement. To date, the Australian scheme has provided very limited opportunities for Pacific workers. This raises concerns about the long-term viability of this highly regulated scheme and the capacity to move beyond a pilot program to provide sustained opportunities for both Pacific workers and the horticulture industry.23 page(s

    A secure fog-based platform for SCADA-based IoT critical infrastructure

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    © 2019 John Wiley & Sons, Ltd. The rapid proliferation of Internet of things (IoT) devices, such as smart meters and water valves, into industrial critical infrastructures and control systems has put stringent performance and scalability requirements on modern Supervisory Control and Data Acquisition (SCADA) systems. While cloud computing has enabled modern SCADA systems to cope with the increasing amount of data generated by sensors, actuators, and control devices, there has been a growing interest recently to deploy edge data centers in fog architectures to secure low-latency and enhanced security for mission-critical data. However, fog security and privacy for SCADA-based IoT critical infrastructures remains an under-researched area. To address this challenge, this contribution proposes a novel security “toolbox” to reinforce the integrity, security, and privacy of SCADA-based IoT critical infrastructure at the fog layer. The toolbox incorporates a key feature: a cryptographic-based access approach to the cloud services using identity-based cryptography and signature schemes at the fog layer. We present the implementation details of a prototype for our proposed secure fog-based platform and provide performance evaluation results to demonstrate the appropriateness of the proposed platform in a real-world scenario. These results can pave the way toward the development of a more secure and trusted SCADA-based IoT critical infrastructure, which is essential to counter cyber threats against next-generation critical infrastructure and industrial control systems. The results from the experiments demonstrate a superior performance of the secure fog-based platform, which is around 2.8 seconds when adding five virtual machines (VMs), 3.2 seconds when adding 10 VMs, and 112 seconds when adding 1000 VMs, compared to the multilevel user access control platform

    Astrocyte-mediated short-term synaptic depression in the rat hippocampal CA1 area: two modes of decreasing release probability

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    <p>Abstract</p> <p>Background</p> <p>Synaptic burst activation feeds back as a short-term depression of release probability at hippocampal CA3-CA1 synapses. This short-term synaptic plasticity requires functional astrocytes and it affects both the recently active (< 1 s) synapses (post-burst depression) as well as inactive neighboring synapses (transient heterosynaptic depression). The aim of this study was to investigate and compare the components contributing to the depression of release probability in these two different scenarios.</p> <p>Results</p> <p>When tested using paired-pulses, following a period of inactivity, the transient heterosynaptic depression was expressed as a reduction in the response to only the first pulse, whereas the response to the second pulse was unaffected. This selective depression of only the first response in a high-frequency burst was shared by the homosynaptic post-burst depression, but it was partially counteracted by augmentation at these recently active synapses. In addition, the expression of the homosynaptic post-burst depression included an astrocyte-mediated reduction of the pool of release-ready primed vesicles.</p> <p>Conclusions</p> <p>Our results suggest that activated astrocytes depress the release probability via two different mechanisms; by depression of vesicular release probability only at inactive synapses and by imposing a delay in the recovery of the primed pool of vesicles following depletion. These mechanisms restrict the expression of the astrocyte-mediated depression to temporal windows that are typical for synaptic burst activity.</p

    Aryl urea substituted fatty acids: a new class of protonophoric mitochondrial uncoupler that utilises a synthetic anion transporter

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    A new mitochondrial uncoupler that forms membrane permeable dimers through interactions of remote acidic and anion receptor groups.</p

    Regulation of human intestinal T-cell responses by type 1 interferon-STAT1 signaling is disrupted in inflammatory bowel disease

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    This work was supported by a research fellowship grant from the Crohn’s and Colitis in Childhood Research Association (CICRA) and a small project grant from Crohn’s and Colitis UK (CCUK). We would like to acknowledge Professor Ian Sanderson, who helped with the initial design of this work, and provided important support throughout. We would also like to thank Dr Gary Warne for his advice and assistance in the use of the sorting by flow cytometry. We would also like to thank Dr Raj Lahiri and Professor Graham Foster for the kind gift of the primers for the ISGs (2’5’ OAS and MxA)

    Holocene sea level fluctuations and coastal evolution in the central Algarve (southern Portugal)

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    In Armação de Pêra Bay, southern Portugal, environmental changes during the Holocene can be interpreted based on the morphological and sedimentological similarities between older geomorphic features (cemented beach and dune rocks) and present coastal features. Using knowledge of the present beach and dune processes, we propose a two-step model for the evolution of Armação de Pêra Bay. First, during the rapid sea level rise between about 8800 and 6600 yr cal BP, the bay changed from a positive to a negative budget littoral cell and transgressive dunes formed, favoured by drought conditions. At about 5000 yr cal BP, during a sea level maximum, beach width was less than the critical fetch and dunes stabilized and underwent cementation during the wetter Atlantic climatic event. The second phase of dune accumulation started at about 3200 yr cal BP, due to a regression of sea level during which the bay changed back to a positive budget littoral cell in which beach width was greater than the critical fetch. Currently, the beach width is less than the critical fetch, dunes are inactive, and the sedimentary budget is negative due to sediment storage in local river systems.Fundação para a Ciência e a Tecnologia. FEDER, and OE (Project POCTI/CTA/34162/2000

    Enhancement Effects of Martentoxin on Glioma BK Channel and BK Channel (α+β1) Subtypes

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    BACKGROUND: BK channels are usually activated by membrane depolarization and cytoplasmic Ca(2+). Especially,the activity of BK channel (α+β4) can be modulated by martentoxin, a 37 residues peptide, with Ca(2+)-dependent manner. gBK channel (glioma BK channel) and BK channel (α+β1) possessed higher Ca(2+) sensitivity than other known BK channel subtypes. METHODOLOGY AND PRINCIPAL FINDINGS: The present study investigated the modulatory characteristics of martentoxin on these two BK channel subtypes by electrophysiological recordings, cell proliferation and Ca(2+) imaging. In the presence of cytoplasmic Ca(2+), martentoxin could enhance the activities of both gBK and BK channel (α+β1) subtypes in dose-dependent manner with EC(50) of 46.7 nM and 495 nM respectively, while not shift the steady-state activation of these channels. The enhancement ratio of martentoxin on gBK and BK channel (α+β1) was unrelated to the quantitative change of cytoplasmic Ca(2+) concentrations though the interaction between martentoxin and BK channel (α+β1) was accelerated under higher cytoplasmic Ca(2+). The selective BK pore blocker iberiotoxin could fully abolish the enhancement of these two BK subtypes induced by martentoxin, suggesting that the auxiliary β subunit might contribute to the docking for martentoxin. However, in the absence of cytoplasmic Ca(2+), the activity of gBK channel would be surprisingly inhibited by martentoxin while BK channel (α+β1) couldn't be affected by the toxin. CONCLUSIONS AND SIGNIFICANCE: Thus, the results shown here provide the novel evidence that martentoxin could increase the two Ca(2+)-hypersensitive BK channel subtypes activities in a new manner and indicate that β subunit of these BK channels plays a vital role in this enhancement by martentoxin

    Phosphodiesterase Inhibition Increases CREB Phosphorylation and Restores Orientation Selectivity in a Model of Fetal Alcohol Spectrum Disorders

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    Background: Fetal alcohol spectrum disorders (FASD) are the leading cause of mental retardation in the western world and children with FASD present altered somatosensory, auditory and visual processing. There is growing evidence that some of these sensory processing problems may be related to altered cortical maps caused by impaired developmental neuronal plasticity. Methodology/Principal Findings: Here we show that the primary visual cortex of ferrets exposed to alcohol during the third trimester equivalent of human gestation have decreased CREB phosphorylation and poor orientation selectivity revealed by western blotting, optical imaging of intrinsic signals and single-unit extracellular recording techniques. Treating animals several days after the period of alcohol exposure with a phosphodiesterase type 1 inhibitor (Vinpocetine) increased CREB phosphorylation and restored orientation selectivity columns and neuronal orientation tuning. Conclusions/Significance: These findings suggest that CREB function is important for the maturation of orientation selectivity and that plasticity enhancement by vinpocetine may play a role in the treatment of sensory problems in FASD

    Measurement of energetic single-photon production at LEP

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