1,220 research outputs found

    Kv7 and Kv11 channels in myometrial regulation.

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    Ion channels play a key role in defining myometrial contractility. Modulation of ion channel populations is proposed to underpin gestational changes in uterine contractility associated with the transition from uterine quiescence to active labour. Of the myriad ion channels present in the uterus, this article will focus upon potassium channels encoded by the KCNQ genes and ether-à-go-go-related (ERG) genes. Voltage-gated potassium channels encoded by KCNQ and ERG (termed Kv7 and Kv11, respectively) are accepted as major determinants of neuronal excitability and the duration of the cardiac action potential. However, there is now growing appreciation that these ion channels have a major functional impact in vascular and non-vascular smooth muscle. Moreover, Kv7 channels may be potential therapeutic targets for the treatment of preterm labour

    Mountaineer Jamboree: Country Music in West Virginia

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    Jamboree! To many country music fans the word conjures up memories of Saturday nights around the family radio listening to live broadcasts from that haven of hillbilly music, West Virginia. From 1926 through the 1950s, as Ivan Tribe shows in his lively history, country music radio programming made the Mountain State a mecca for country singers and instrumentalists from all over America. Wilma Lee and Stoney Cooper, Little Jimmy Dickens, Hawkshaw Hawkins, Red Sovine, Blaine Smith, Curly Ray Cline, Grandpa Jones, Cowboy Loye, Rex and Eleanor Parker, Lee Moore, Buddy Starcher, Doc and Chickie Williams, and Molly O\u27Day were among the many who came to prominence via West Virginia radio. Wheeling\u27s WWVA jamboree, first broadcast in 1933, attracted a wide audience, especially after 1942, when the station increased its power. The show\u27s success spawned numerous competitors, as new stations all over West Virginia followed WWVA\u27s lead in headlining country music. The state also played an important role in the early recording industry. The Tweedy Brothers, Frank Hutchison, Roy Harvey, Blind Alfred Reed, Frank Welling and John McGhee, Cap and Andy, and the Kessinger Brothers were among West Virginians whose waxings contributed to the state\u27s reputation for fine native musicianship. So too did those who sought out and recorded the Mountaineer folksong heritage. As Nashville\u27s dominance has grown since the 1960s, West Virginia\u27s leadership in country music has lessened. Young performers must now seek fame outside their native state. But, as Ivan Tribe demonstrates, the state\u27s numerous outdoor festivals continue to keep alive the heritage of country music\u27s mountain mama. Ivan Tribe is assistant professor of history at Rio Grande College in Ohio. What emerges is a much deeper understanding of how vital early commercial country music was in this area of Appalachia, serving both as a means of reinforcing local culture and tying it to the world outside the region, thanks to recordings and the broadcast media. -- 1998 Yearbook for Traditional Music No fan of country music can afford to be without this book. -- Huntington Herald-Dispatch Tribe writes with an insider’s knowledge, having grown up listening to many of these performers. -- Journal of Southern Historyhttps://uknowledge.uky.edu/upk_cultural_history/1010/thumbnail.jp

    Optimization of photomixers and antennas for continuous-wave terahertz emission

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    We have studied terahertz emission from interdigitated finger photomixers coupled to planar antenna structures. Using both pulsed and continuous-wave excitation, polarization measurements reveal that the antenna design dominates the properties of the radiated output at frequencies below 0.6 THz, while the efficiency at higher frequencies is additionally dependent on the design of the photomixer fingers. We have produced terahertz maps of the device, characterizing the photomixer by measuring the generated power as a function of the excitation position. Together, these measurements have allowed us to understand better the distinct roles of the photomixer and antenna in emission at different fre

    Temporal changes in the geographic distribution, elevation, and potential origin of the Martian outflow channels

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    Observational evidence of outflow channel activity on Mars suggests that water was abundant in the planet's early crust. However, with the decline in the planet's internal heat flow, a freezing front developed within the regolith that propagated downward with time and acted as a thermodynamic sink for crustal H2O. One result of this thermal evolution is that, if the initial inventory of water on Mars was small, the cryosphere may have grown to the point where all the available water was taken up as ground ice. Alternatively, if the inventory of H2O exceeds the current pore volume of the cryosphere, then Mars has always possessed extensive bodies of subpermafrost groundwater. We have investigated the relative age, geographic distribution, elevation, and geologic setting of the outflow channels in an effort to accomplish the following: (1) identify possible modes of origin and evolutionary trends in their formation; (2) gain evidence regarding the duration and spatial distribution of groundwater in the crust; and (3) better constraint estimates of the planetary inventory of H2O

    Effect of skin dielectric properties on the read range of epidermal ultra-high frequency radio-frequency identification tags

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    This Letter presents an investigation of the effect of human tissue conductivity and permittivity on the performance of epidermal transfer tattoo ultra-high frequency radio-frequency identification (RFID) tags. The measurements were carried out on 20 individuals and the variations in the measured dielectric properties correlate well with variations in the measured tag read range on the individuals and to a lesser extent with their body mass index values. Simulation results also showed the effects of permittivity and conductivity on the designed resonance frequency of the RFID tag

    The Geomorphology of Farewell Spit and Its Sensitivity to Sea-Level Rise

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    Sand-dominated barriers are highly sensitive coastal systems which alter their morphology in response to rising sea level, undergoing extensive sediment reworking as wave activity reaches further inland. Farewell Spit, South Island, New Zealand, is a sand-dominated barrier spit which extends 25kms eastward from the mainland, enclosing the northwestern corner of the macro-tidal Golden Bay. During spring tide cycles low-lying areas of the Spit become completely inundated. The aim of this study is to establish the morphological stability of Farewell Spit and its potential response to the latest IPCC projected eustatic sea-level rise of 0.48m (A1B scenario) by the end of this century. GIS analysis of aerial photographs and the identification of 137Cs signatures within the dunes have shown a high degree of mobility in the Spit's features over the past 55 years. Vegetation increased by 75%, mainly due to the introduction of A arenaria, which has also led to the development of foredunes prograding up to 142m over the tidal flats. Barchan dunes on the Spit are also highly mobile migrating at up to 30m/y. The high amount of sediment movement along the spit is reflected in the sedimentology of the tidal flats, which show layers of aeolian transported fine, well-sorted sand several centimetres thick. The predominance of medium sand shows that reworking appears to have occurred on these flats due to storm events in Golden Bay, and like the dunes, 14C dating indicates they are very young features Projected sea-level rise was modelled to assess the vulnerability of low-lying areas of the Spit to tidal flooding. Deeper water levels in the two tidal channels which currently flood across the Spit are expected and there is a risk of additional channels opening, one being very near to the contact between the Spit and mainland. The mobility of the dune systems may however buffer some of these processes by providing natural defences against the sea. Barrier roll over does not appear to be an important process as it appears to be too wide to allow for washover. It is concluded that under current sea-level rise predictions Farewell Spit will not transgress landward but will be subject to exacerbated erosion

    Realization of an Interacting Two-Valley AlAs Bilayer System

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    By using different widths for two AlAs quantum wells comprising a bilayer system, we force the X-point conduction-band electrons in the two layers to occupy valleys with different Fermi contours, electron effective masses, and g-factors. Since the occupied valleys are at different X-points of the Brillouin zone, the interlayer tunneling is negligibly small despite the close electron layer spacing. We demonstrate the realization of this system via magneto-transport measurements and the observation of a phase-coherent, bilayer ν\nu=1 quantum Hall state flanked by a reentrant insulating phase.Comment: 5 page

    Neonatal weight loss and gain patterns in caesarean section born infants : integrative systematic review

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    There is evidence that caesarean section delivery can impact on neonatal weight loss and weight gain patterns in the first 5 days of life. We conducted an integrative systematic review to examine the association of mode of delivery on early neonatal weight loss. Pubmed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Excerpta Medica dataBASE, and Medical Literature Analysis and Retrieval System Online were searched for relevant papers published before June 2019. Reference lists from the relevant papers were then backwards and forwards searched. As neonatal weight loss was reported in different formats, a meta‐analysis could not be carried out. Most studies did not distinguish between elective and emergency caesarean sections or instrumental and nonassisted vaginal deliveries. Seven papers were included. All papers except one found that caesarean section was associated with higher weight loss in the early days of life. Two papers presented data from studies on babies followed up to 1 month. One study found that on day 25, babies born by caesarean section had significantly higher weight gain than those born vaginally, while another found that by day 28, babies born vaginally gained more weight per day (11.9 g/kg/day) than those born by caesarean section (10.9 g/kg/day; p = .02). Overall, infants born by caesarean section lost more weight than those born vaginally, but due to the small number of studies included, more are needed to look at this difference and why it may occur. This discrepancy in weight between the two groups may be corrected over time, but future studies will need larger sample sizes and longer follow‐up periods to examine this
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