202 research outputs found

    Magnetomotive drive and detection of clamped-clamped mechanical resonators in water

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    We demonstrate magnetomotive drive and detection of doubly clamped string resonators in water. A compact 1.9 T permanent magnet is used to detect the fundamental and higher flexural modes of 200μm\mathrm{200 \mu m} long resonators. Good agreement is found between the magnetomotive measurements and optical measurements performed on the same resonator. The magnetomotive detection scheme can be used to simultaneously drive and detect multiple sensors or scanning probes in viscous fluids without alignment of detector beams.Comment: 4 pages, 3 figure

    Lateral hypothalamus is required for context-induced reinstatement of extinguished reward seeking

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    We studied the role of lateral hypothalamus (LH) in context-induced reinstatement (renewal) of reward seeking. Rats were trained to respond for 4% (v/v) alcoholic beer or 10% (w/v) sucrose reward in one context (Context A) before extinction training in a second context (Context B). On test, rats were returned to the training context, A (ABA), or the extinction context, B (ABB). Return to the training context (ABA) produced robust reinstatement. Reversible inactivation of LH via baclofen/muscimol infusion prevented context-induced reinstatement of beer and sucrose seeking. This prevention was specific to bilateral infusions into LH. We then used the retrograde neuronal tracer cholera toxin b subunit (CTb) combined with detection of the c-Fos protein to identify activated afferents to LH during context-induced reinstatement of beer seeking. Double labeling for c-Fos and CTb revealed a significant recruitment of LH-projecting neurons in nucleus accumbens shell (AcbSh) during reinstatement. These afferents could be classified into two anatomically and functionally distinct groups. First, afferents in the ventral AcbSh projecting to LH were activated during reinstatement. Second, afferents in the dorsomedial AcbSh projecting to LH were activated during test in the extinction context. These recruitments were specific to an AcbSh–LH pathway because they were not observed following CTb injection into the immediately adjacent perifornical hypothalamus. These results show that LH is critical for context-induced reinstatement of reward seeking and that parallel striatal-hypothalamic pathways are recruited following return to the training versus extinction contexts

    Tropical cyclones and the ecohydrology of Australia's recent continental-scale drought

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    The Big Dry, a recent drought over southeast Australia, began around 1997 and continued until 2011. We show that between 2002-2010, instead of a localized drought, there was a continent-wide reduction in water storage, vegetation and rainfall, spanning the northwest to the southeast of Australia. Trends in water storage and vegetation were assessed using Gravity Recovery and Climate Experiment (GRACE) and Normalized Difference Vegetation Index (NDVI) data. Water storage and NDVI are shown to be significantly correlated across the continent and the greatest losses of water storage occurred over northwest Australia. The frequency of tropical cyclones over northwest Australia peaked just prior to the launch of the GRACE mission in 2002. Indeed, since 1981, decade-scale fluctuations in tropical cyclone numbers coincide with similar variation in rainfall and vegetation over northwest Australia. Rainfall and vegetation in southeast Australia trended oppositely to the northwest prior to 2001. Despite differences between the northwest and southeast droughts, there is reason to believe that continental droughts may occur when the respective climate drivers align

    Drink driving among Aboriginal and Torres Strait Islander Australians: what has been done and where to next?

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    The Australian Government will set the direction for addressing road safety over the next decade with its 2021–2030 National Road Safety Strategy. This road map will detail objectives and goals agreed upon by all Australian states and territories. Similar to previous national strategies, Aboriginal and Torres Strait Islander (Indigenous) Australians are a high priority population. Indigenous Australians are over-represented in serious injury and fatal road crashes, with alcohol a leading factor. Therapeutic and educational programs are a major strategy among the suite of measures designed to reduce and prevent drink driving in Australia. The release of this new strategy provides a timely opportunity to reflect on what is known about drink driving among Indigenous Australians and to consider the suitability of existing therapeutic and educational drink driving programs for Indigenous Australian contexts. Here, we summarise factors that contribute to drink driving in this population and identify outstanding knowledge gaps. Then, we present an overview of drink driving programs available for Indigenous Australians along with suggestions for why tailored programs are needed to suit local contexts. The response to address drink driving among Indigenous Australians has been fragmented Australia-wide. A coordinated national response, with ongoing monitoring and evaluation, would improve policy effectiveness and inform more efficient allocation of resources. Together this information can help create suitable and effective drink driving programs for Indigenous drivers and communities Australia-wide

    After the Left–Right (Dis)continuum: Globalization and the Remaking of Europe’s Ideological Geography

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    This article examines the status of globalization as a causal factor in political mobilization and proposes a research agenda for diagnosing the impact of global socio-economic dynamics on ideological orientation in national polities. Focusing on Europe’s established democracies, the article outlines recent shifts in Europe’s ideological landscape and explores the mechanisms generating a new pattern of political conflict and electoral competition. It advances the hypothesis that the knowledge economy of open borders has brought about a political cleavage inti- mately linked to citizens’ perceptions of the social impact of global eco- nomic integration. In this context, the polarization of life chances is determined by institutionally mediated exposure to both the economic opportunities and the hazards of globalization. Fostered by the increas- ing relevance of the international for state-bound publics, new fault-lines of social conflict are emerging, giving shape to a new, ‘‘opportunity- risk,’’ axis of political competition. As the novel political cleavage challenges the conventional left–right divide, it is likely to radically alter Europe’s ideological geography

    Fabrication and characterisation of nanocrystalline graphite MEMS resonators using a geometric design to control buckling

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    The simulation, fabrication and characterisation of nanographite MEMS resonators is reported in this paper. The deposition of nanographite is achieved using plasma-enhanced chemical vapour deposition directly onto numerous substrates such as commercial silicon wafers. As a result, many of the reliability issues of devices based on transferred graphene are avoided. The fabrication of the resonators is presented along with a simple undercutting method to overcome buckling, by changing the effective stress of the structure from 436 MPa compressive, to 13 MPa tensile. The characterisation of the resonators using electrostatic actuation and laser Doppler vibrometry is reported, demonstrating resonator frequencies from 5–640 kHz and quality factor above 1819 in vacuum obtained

    Vertical flight training: An overview of training and flight simulator technology with emphasis on rotary-wing requirements

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    The principal purpose of this publication is to provide a broad overview of the technology that is relevant to the design of aviation training systems and of the techniques applicable to the development, use, and evaluation of those systems. The issues addressed in our 11 chapters are, for the most part, those that would be expected to surface in any informed discussion of the major characterizing elements of aviation training systems. Indeed, many of the same facets of vertical-flight training discussed were recognized and, to some extent, dealt with at the 1991 NASA/FAA Helicopter Simulator Workshop. These generic topics are essential to a sound understanding of training and training systems, and they quite properly form the basis of any attempt to systematize the development and evaluation of more effective, more efficient, more productive, and more economical approaches to aircrew training. Individual chapters address the following topics: an overview of the vertical flight industry: the source of training requirements; training and training schools: meeting current requirements; training systems design and development; transfer of training and cost-effectiveness; the military quest for flight training effectiveness; alternative training systems; training device manufacturing; simulator aero model implementation; simulation validation in the frequency domain; cockpit motion in helicopter simulation; and visual space perception in flight simulators

    The Type III Effectors NleE and NleB from Enteropathogenic E. coli and OspZ from Shigella Block Nuclear Translocation of NF-κB p65

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    Many bacterial pathogens utilize a type III secretion system to deliver multiple effector proteins into host cells. Here we found that the type III effectors, NleE from enteropathogenic E. coli (EPEC) and OspZ from Shigella, blocked translocation of the p65 subunit of the transcription factor, NF-κB, to the host cell nucleus. NF-κB inhibition by NleE was associated with decreased IL-8 expression in EPEC-infected intestinal epithelial cells. Ectopically expressed NleE also blocked nuclear translocation of p65 and c-Rel, but not p50 or STAT1/2. NleE homologues from other attaching and effacing pathogens as well OspZ from Shigella flexneri 6 and Shigella boydii, also inhibited NF-κB activation and p65 nuclear import; however, a truncated form of OspZ from S. flexneri 2a that carries a 36 amino acid deletion at the C-terminus had no inhibitory activity. We determined that the C-termini of NleE and full length OspZ were functionally interchangeable and identified a six amino acid motif, IDSY(M/I)K, that was important for both NleE- and OspZ-mediated inhibition of NF-κB activity. We also established that NleB, encoded directly upstream from NleE, suppressed NF-κB activation. Whereas NleE inhibited both TNFα and IL-1β stimulated p65 nuclear translocation and IκB degradation, NleB inhibited the TNFα pathway only. Neither NleE nor NleB inhibited AP-1 activation, suggesting that the modulatory activity of the effectors was specific for NF-κB signaling. Overall our data show that EPEC and Shigella have evolved similar T3SS-dependent means to manipulate host inflammatory pathways by interfering with the activation of selected host transcriptional regulators

    Going it alone? North Korea’s adaptability as a small power in a changing world

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    This article uses small states scholarship to map North Korea’s evolution from a post-colonial small state to a system-influencing state due to its nuclear weapons programme. The framework allows for contributions to: (1) The DPRK literature which in some parts has suggested the future collapse of the state, (2) The small states literature that suggests they can only survive if they integrate larger political and/or economic units, (3) The mainstream IR literature and its dominant realist streak that considers great powers and their will as the main drivers in contemporary world politics
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