298 research outputs found

    Some Phonetic Structures of Koasati

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    This paper presents results of the first quantitative phonetic study of Koasati, a Muskogean language spoken in Louisiana and Texas. We examine vowel quality, length contrasts in vowels and consonants, the limited system of lexical tone contrasts in nouns, and the grammatical system of tone in verbs. We also study the realization of several word-final consonant clusters (fn, tl, lw, etc.) that are absent in related languages and that are typologically unusual due to their sonority reversals. Finally, we examine the cognates in related languages of the tones we document in Koasati nouns and verbs

    Big Cwatsets and Hamming Code

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    In contrast to Lagrange\u27s Theorem in Finite Group Theory, we show that the ratio of the largest proper cwatset of degree d to the size of binary d-space approaches 1 as d approaches infinity. We show how to explicitly construct large cwatsets as cosets of Hamming Codes, and discuss many open questions that arise

    Managing multi-platform materials: selected case studies.

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    Mobile devices and Internet usage are now common in most parts of the world. Archives and other cultural agencies are challenged by the increasing amounts, and complexity, of digital content. New strategies are being developed and promoted to enable digital acquisition and preservation. The National Film and Sound Archive of Australia (NFSA) is examining and addressing acquisition and preservation challenges for a range of complex digital content, within available resources. This paper will discuss issues associated with a range of multi-platform content with reference to selected case studies

    Electrostatically Tunable Meta-Atoms Integrated With In Situ Fabricated MEMS Cantilever Beam Arrays

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    Two concentric split ring resonators (SRRs) or meta-atoms designed to have a resonant frequency of 14 GHz are integrated with microelectromechanical systems cantilever arrays to enable electrostatic tuning of the resonant frequency. The entire structure was fabricated monolithically to improve scalability and minimize losses from externally wire-bonded components. A cantilever array was fabricated in the gap of both the inner and outer SRRs and consisted of five evenly spaced beams with lengths ranging from 300 to 400 μm. The cantilevers pulled in between 15 and 24 V depending on the beam geometry. Each pulled-in beam increased the SRR gap capacitance resulting in an overall 1-GHz shift of the measured meta-atom resonant frequency

    An investigation of changes in children′s mental health in Wales between 2007/2008 and 2012/2013

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    Improving children’s mental well-being is a recognised public health priority, but evidence on recent trends is lacking. This study updates evidence on differences in child mental health since 2008 by comparing two nationally representative cohorts in Wales, UK. Parents of 4-12 year old children completed the Strength and Difficulties Questionnaire (SDQ). No significant differences were seen for younger girls between 2007/2008 and 2012/2013. There was a decrease in conduct, hyperactivity and total difficulties symptom scores and an increase in prosocial scores for boys’ and older girls. These findings suggest that rates of child mental health problems are stable or falling

    Temperature sensitivity of organic-matter decay in tidal marshes

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    Approximately half of marine carbon sequestration takes place in coastal wetlands, including tidal marshes, where organic matter contributes to soil elevation and ecosystem persistence in the face of sea-level rise. The long-term viability of marshes and their carbon pools depends, in part, on how the balance between productivity and decay responds to climate change. Here, we report the sensitivity of labile soil organic-matter decay in tidal marshes to seasonal and latitudinal variations in temperature measured over a 3-year period. We find a moderate increase in decay rate at warmer temperatures (3-6% per degrees C, Q(10) = 1.3-1.5). Despite the profound differences between microbial metabolism in wetlands and uplands, our results indicate a strong conservation of temperature sensitivity. Moreover, simple comparisons with organic-matter production suggest that elevated atmospheric CO2 and warmer temperatures will accelerate carbon accumulation in marsh soils, and potentially enhance their ability to survive sea-level rise

    The Effects of Prenatal Protein Restriction on β-Adrenergic Signalling of the Adult Rat Heart during Ischaemia Reperfusion

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    A maternal low-protein diet (MLP) fed during pregnancy leads to hypertension in adult rat offspring. Hypertension is a major risk factor for ischaemic heart disease. This study examined the capacity of hearts from MLP-exposed offspring to recover from myocardial ischaemia-reperfusion (IR) and related this to cardiac expression of β-adrenergic receptors (β-AR) and their associated G proteins. Pregnant rats were fed control (CON) or MLP diets (n = 12 each group) throughout pregnancy. When aged 6 months, hearts from offspring underwent Langendorff cannulation to assess contractile function during baseline perfusion, 30 min ischemia and 60 min reperfusion. CON male hearts demonstrated impaired recovery in left ventricular pressure (LVP) and dP/dtmax (P < 0.01) during reperfusion when compared to MLP male hearts. Maternal diet had no effect on female hearts to recover from IR. MLP males exhibited greater membrane expression of β2-AR following reperfusion and urinary excretion of noradrenaline and dopamine was lower in MLP and CON female rats versus CON males. In conclusion, the improved cardiac recovery in MLP male offspring following IR was attributed to greater membrane expression of β2-AR and reduced noradrenaline and dopamine levels. In contrast, females exhibiting both decreased membrane expression of β2-AR and catecholamine levels were protected from IR injury

    SRRs Embedded with MEMS Cantilevers to Enable Electrostatic Tuning of the Resonant Frequency

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    A microelectromechanical systems (MEMS) cantilever array was monolithically fabricated in the gap region of a split ring resonator (SRR) to enable electrostatic tuning of the resonant frequency. The design consisted of two concentric SRRs each with a set of cantilevers extending across the split region. The cantilever array consisted of five beams that varied in length from 300 to 400 μm, with each beam adding about 2 pF to the capacitance as it actuated. The entire structure was fabricated monolithically to reduce its size and minimize losses from externally wire bonded components. The beams actuate one at a time, longest to shortest with an applied voltage ranging from 30–60 V. The MEMS embedded SRRs displayed dual resonant frequencies at 7.3 and 14.2 GHz or 8.4 and 13.5 GHz depending on the design details. As the beams on the inner SRR actuated the 14.2 GHz resonance displayed tuning, while the cantilevers on the outer SRR tuned the 8.4 GHz resonance. The 14.2 GHz resonant frequency shifts 1.6 GHz to 12.6 GHz as all the cantilevers pulled-in. Only the first two beams on the outer cantilever array pulled-in, tuning the resonant frequency 0.4 GHz from 8.4 to 8.0 GHz
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