109 research outputs found

    (Re)producing the ‘history problem’: memory, identity and the Japan-South Korea trade dispute

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    Japan-South Korea relations have consistently been presented by International Relations scholars as a puzzle that confounds mainstream rationalist theories, which struggle to explain the consistent acrimony associated with the so-called ‘history problem’. While many scholars have, therefore, adopted conventional constructivist approaches to incorporate history into their analyses, such literature often neglects the processes of (re)construction of this social reality, thereby implicitly treating these negative sentiments as essentialised elements of Korean and Japanese culture/identity which cause certain foreign policies. Using the recent Japan-South Korea trade dispute as a case study, this article instead draws on critical constructivist/poststructuralist theory and discourse analytical methods to examine how the ‘history problem’ is produced and reproduced. It argues that dominant discourses of remembering in South Korea, which represent Japan as an unrepentant colonial aggressor, and of forgetting in Japan, which represent South Korea as emotional and irrational for dwelling on the past, act to (re)produce identities that clash in their attitudes to difficult history. While such foreign policy practices (re)produce dominant national identities, these identities also shape the bounds of which foreign policies are legitimate or imaginable. This mutually constitutive relationship between identity and foreign policy continually reproduces the ‘history problem’ in Japan-South Korea relations

    Rapid and Accurate Measurement of Polarization and Fading of Weak VHF Signals Obliquely Reflected from Sporadic-E Layers

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    In the E-region of the ionosphere, at heights between 90 and 130 km, thin patches of enhanced ionization occur intermittently. The electron density in these sporadic-E (Es) clouds can sometimes be so high that radio waves with frequencies up to 150 MHz are obliquely reflected. While this phenomenon is well known, the reflection mechanism itself is not well understood. To investigate this question, an experimental system has been developed for accurate polarimetric and fading measurements of 50 MHz radio waves obliquely reflected by mid-latitude Es layers. The overall sensitivity of the system is optimized by reducing environmental electromagnetic noise, giving the ability to observe weak, short-lived 50 MHz Es propagation events. The effect of the ground reflection on observed polarization is analyzed and the induced amplitude and phase biases are compensated for. It is found that accurate measurements are only possible below the pseudo-Brewster angle. To demonstrate the effectiveness of the system, initial empirical results are presented which provide clear evidence of magneto-ionic double refraction

    Evidence for the Magnetoionic Nature of Oblique VHF Reflections from Midlatitude Sporadic-E Layers

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    Mid-latitude sporadic-E (Es) is an intermittent phenomenon of the lower E region of the ionosphere. Es clouds are thin, transient, and patchy layers of intense ionization, with ionization densities which can be much higher than in the background ionosphere. Oblique reflection of radio signals in the very high frequency (VHF) range is regularly supported, but the mechanism for it has never been clearly established—specular reflection, scattering, and magnetoionic double refraction have all been suggested. This article proposes using the polarization behaviour of signals reflected from intense midlatitude sporadic-E clouds as an indicator of the true reflection mechanism. Results are presented from a measurement campaign in the summer of 2018, which gathered a large amount of data at a receiving station in the UK using 50 MHz amateur radio beacons as signal sources. In all cases the signals received were elliptically polarized, despite being transmitted with linear polarization; there were also indications that polarization behaviour varied systematically with the orientation of the path to the geomagnetic field. This represents, for all the examples recorded, clear evidence that signals were reflected from midlatitude Es by magnetoionic double refraction

    Successful use of axonal transport for drug delivery by synthetic molecular vehicles

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    We report the use of axonal transport to achieve intraneural drug delivery. We constructed a novel tripartite complex of an axonal transport facilitator conjugated to a linker molecule bearing up to a hundred reversibly attached drug molecules. The complex efficiently enters nerve terminals after intramuscular or intradermal administration and travels within axonal processes to neuron cell bodies. The tripartite agent provided 100-fold amplification of saturable neural uptake events, delivering multiple drug molecules per complex. _In vivo_, analgesic drug delivery to systemic and to non-targeted neural tissues was greatly reduced compared to existing routes of administration, thus exemplifying the possibility of specific nerve root targeting and effectively increasing the potency of the candidate drug gabapentin 300-fold relative to oral administration

    Manual versus powered toothbrushes for oral health; an update

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    Background: Plaque removal is a cornerstone in the prevention and treatment of periodontal diseases. Powered toothbrushes have been devised to assist in plaque removal. An earlier Cochrane systematic review found that only powered toothbrushes with a rotation-oscillation action were more effective at removing plaque and reducing gingivitis. That review requires updating to include recent trials. Objective: To compare the effects of manual and powered toothbrushes on plaque removal and gingival health. Method: We searched the Cochrane Oral Health Group Trials Register, CENTRAL; MEDLINE, EMBASE and CINAHL to 9 March 2011. Manufacturers and authors were contacted for additional data. Trials were selected for random allocation of participants to use a manual or powered toothbrush. Participants were members of the public with uncompromised manual dexterity who brushed unsupervised for at least 4 weeks. There was no language restriction. Primary outcomes were plaque and gingivitis scores at the end of the trial. Assessment of methodological quality and data extraction were conducted in duplicate. Potential sources of heterogeneity were examined, along with sensitivity analyses for quality and publication bias. Results: Fifty trials, involving 4326 participants, provided data. Effect sizes, calculated as standardized mean difference (95% confidence intervals) for brushes with a rotation oscillation action were: 1 to 3 months >3 months Plaque -0.53 (-0.74 to -0.31) -0.66 (-1.28 to -0.03) Gingivitis -0.49 (-0.73 to -0.26) -0.34 (-0.56 to -0.11) This represents approximately 27% fewer sites with bleeding on probing in the long term. No other powered designs were consistently superior to manual toothbrushes. There was considerable heterogeneity between trials. Sensitivity analyses revealed the results to be robust when selecting trials of high quality. Conclusion: Rotation-oscillation powered toothbrushes remove plaque and reduce gingivitis more than manual brushes in the short and long term

    Renewing the link between cognitive archeology and cognitive science

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    In cognitive archeology, theories of cognition are used to guide interpretation of archeological evidence. This process provides useful feedback on the theories themselves. The attempt to accommodate archeological data helps shape ideas about how human cognition has evolved and thus—by extension—how the modern form functions. But the implications that archeology has for cognitive science particularly relate to traditional proposals from the field involving modular decomposition, symbolic thought and the mediating role of language. There is a need to make a connection with more recent approaches, which more strongly emphasize information, probabilistic reasoning and exploitation of embodiment. Proposals from cognitive archeology, in which evolution of cognition is seen to involve a transition to symbolic thought need to be realigned with theories from cognitive science that no longer give symbolic reasoning a central role. The present paper develops an informational approach, in which the transition is understood to involve cumulative development of information-rich generalizations

    Tri-partite complex for axonal transport drug delivery achieves pharmacological effect.

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    BACKGROUND: Targeted delivery of pharmaceutical agents into selected populations of CNS (Central Nervous System) neurons is an extremely compelling goal. Currently, systemic methods are generally used for delivery of pain medications, anti-virals for treatment of dermatomal infections, anti-spasmodics, and neuroprotectants. Systemic side effects or undesirable effects on parts of the CNS that are not involved in the pathology limit efficacy and limit clinical utility for many classes of pharmaceuticals. Axonal transport from the periphery offers a possible selective route, but there has been little progress towards design of agents that can accomplish targeted delivery via this intraneural route. To achieve this goal, we developed a tripartite molecular construction concept involving an axonal transport facilitator molecule, a polymer linker, and a large number of drug molecules conjugated to the linker, then sought to evaluate its neurobiology and pharmacological behavior. RESULTS: We developed chemical synthesis methodologies for assembling these tripartite complexes using a variety of axonal transport facilitators including nerve growth factor, wheat germ agglutinin, and synthetic facilitators derived from phage display work. Loading of up to 100 drug molecules per complex was achieved. Conjugation methods were used that allowed the drugs to be released in active form inside the cell body after transport. Intramuscular and intradermal injection proved effective for introducing pharmacologically effective doses into selected populations of CNS neurons. Pharmacological efficacy with gabapentin in a paw withdrawal latency model revealed a ten fold increase in half life and a 300 fold decrease in necessary dose relative to systemic administration for gabapentin when the drug was delivered by axonal transport using the tripartite vehicle. CONCLUSION: Specific targeting of selected subpopulations of CNS neurons for drug delivery by axonal transport holds great promise. The data shown here provide a basic framework for the intraneural pharmacology of this tripartite complex. The pharmacologically efficacious drug delivery demonstrated here verify the fundamental feasibility of using axonal transport for targeted drug delivery.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Getting into hot water:sick guppies frequent warmer thermal conditions

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    Ectotherms depend on the environmental temperature for thermoregulation and exploit thermal regimes that optimise physiological functioning. They may also frequent warmer conditions to up-regulate their immune response against parasite infection and/or impede parasite development. This adaptive response, known as ‘behavioural fever’, has been documented in various taxa including insects, reptiles and fish, but only in response to endoparasite infections. Here, a choice chamber experiment was used to investigate the thermal preferences of a tropical freshwater fish, the Trinidadian guppy (Poecilia reticulata), when infected with a common helminth ectoparasite Gyrodactylus turnbulli, in female-only and mixed-sex shoals. The temperature tolerance of G. turnbulli was also investigated by monitoring parasite population trajectories on guppies maintained at a continuous 18, 24 or 32 °C. Regardless of shoal composition, infected fish frequented the 32 °C choice chamber more often than when uninfected, significantly increasing their mean temperature preference. Parasites maintained continuously at 32 °C decreased to extinction within 3 days, whereas mean parasite abundance increased on hosts incubated at 18 and 24 °C. We show for the first time that gyrodactylid-infected fish have a preference for warmer waters and speculate that sick fish exploit the upper thermal tolerances of their parasites to self medicate
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