160 research outputs found

    Loading of a surface-electrode ion trap from a remote, precooled source

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    We demonstrate loading of ions into a surface-electrode trap (SET) from a remote, laser-cooled source of neutral atoms. We first cool and load \sim 10610^6 neutral 88^{88}Sr atoms into a magneto-optical trap from an oven that has no line of sight with the SET. The cold atoms are then pushed with a resonant laser into the trap region where they are subsequently photoionized and trapped in an SET operated at a cryogenic temperature of 4.6 K. We present studies of the loading process and show that our technique achieves ion loading into a shallow (15 meV depth) trap at rates as high as 125 ions/s while drastically reducing the amount of metal deposition on the trap surface as compared with direct loading from a hot vapor. Furthermore, we note that due to multiple stages of isotopic filtering in our loading process, this technique has the potential for enhanced isotopic selectivity over other loading methods. Rapid loading from a clean, isotopically pure, and precooled source may enable scalable quantum information processing with trapped ions in large, low-depth surface trap arrays that are not amenable to loading from a hot atomic beam

    Rural-urban differences and the break-up of Yugoslavia

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    There has been widespread debate over the possible causes of the break-up of the former Yugoslav federation : but relatively little attention has been paid to the importance of rural-urban differences in this process. The central claim of the article is that the economic, political and social exclusion which some specific segments of the Yugoslav rural population came to experience in relation to the urban-centred “system” can be regarded as having played an important contributory part in the genesis and course of the struggles surrounding the disintegration of Yugoslavia. This broad hypothesis is explored through brief discussions of two case-studies, the Serb krajina in Croatia, and “Herceg-Bosna”. While expressly rejecting single-factor explanations of change, the author argues that in looking for explanations of the phenomenon of secessionism in these cases we need to take into consideration the profound state of economic depression into which these areas had fallen

    Nurses' and student nurses' inferences of pain and psychological distress

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    Poor pain assessment contributes to inadequate postoperative pain relief. Studies in the US suggest that nurse education might make students less sensitive to patients' experience of pain. This research set out to examine this process in the United Kingdom and to explore the experience of the students during their common foundation programme (CFP). 217 students completed the Standard Measure of Inferences of Suffering Questionnaire (SMIS) before and after their CFP. Their inferences of psychological distress increased as studies in the US had found but unlike these studies no change was found in their inferences of pain. Inferences of pain and psychological distress were affected by the age of the cases, while gender affected only the latter. None of the characteristics of the students were related to their inferences Of 51 qualified nurses who completed the SMIS, 5 with high inferences and 5 with low inferences, rated patients for whom they were caring. Over half of their ratings were different from those of the patients' and there was no relationship between their SMIS scores and the tendency to over or under estimate patients' pain casting doubt on the validity of the SMIS. Interviews with 15 students following their CFP showed that they experienced a wide range of strong emotions when caring for patients in pain. Their relatively junior status in the wards seemed to place them in difficult positions and provided them with little support. Theories of desensitisation, cognitive dissonance and acculturation have been proposed to explain decreasing sensitivity to pain. The lack of a significant change in students' inferences of pain and the analysis of their interviews suggest that their experiences are more varied than these theories suggest. These findings have important implications for both nurse education and the mechanisms to support student nurses in clinical practice

    Ethno-geochemical and phytolith studies of activity related patterns: A case study from Al Ma'tan, Jordan

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    Understanding Neolithic sites in southwest Asia is often difficult because of the lack of preservation of organic remains and the effects of various taphonomic processes that alter the original record. Here, we use an ethnographic approach to test the potential of using plant phytoliths and geochemistry to aid our interpretation of southwest Asian Neolithic sites. Our study of a recently abandoned stone and mud constructed village in Jordan, shows that for certain activity types, phytoliths and geochemistry can help distinguish different construction methods and functions, particularly for burnt areas, animal use areas and where there has been the addition of a specific construction material. For features constructed from the same source materials distinctions are more problematic. Geochemical and phytolith proxies were individually effective in distinguishing activity areas and construction materials, but signals were diminished when the statistical analysis was run on both forms of evidence combined. It is therefore recommended that the data from plant phytolith and geochemical analyses are subject to separate statistical tests and that the two sets of results are used in combination to interpret archaeological sites and their uses

    The role of cation-dependent chloride transporters in neuropathic pain following spinal cord injury

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    <p>Abstract</p> <p>Background</p> <p>Altered Cl<sup>- </sup>homeostasis and GABAergic function are associated with nociceptive input hypersensitivity. This study investigated the role of two major intracellular Cl<sup>- </sup>regulatory proteins, Na<sup>+</sup>-K<sup>+</sup>-Cl<sup>- </sup>cotransporter 1 (NKCC1) and K<sup>+</sup>-Cl<sup>- </sup>cotransporter 2 (KCC2), in neuropathic pain following spinal cord injury (SCI).</p> <p>Results</p> <p>Sprague-Dawley rats underwent a contusive SCI at T9 using the MASCIS impactor. The rats developed hyperalgesia between days 21 and 42 post-SCI. Thermal hyperalgesia (TH) was determined by a decrease in hindpaw thermal withdrawal latency time (WLT) between days 21 and 42 post-SCI. Rats with TH were then treated with either vehicle (saline containing 0.25% NaOH) or NKCC1 inhibitor bumetanide (BU, 30 mg/kg, i.p.) in vehicle. TH was then re-measured at 1 h post-injection. Administration of BU significantly increased the mean WLT in rats (p < 0.05). The group administered with the vehicle alone showed no anti-hyperalgesic effects. Moreover, an increase in NKCC1 protein expression occurred in the lesion epicenter of the spinal cord during day 2–14 post-SCI and peaked on day 14 post-SCI (p < 0.05). Concurrently, a down-regulation of KCC2 protein was detected during day 2–14 post-SCI. The rats with TH exhibited a sustained loss of KCC2 protein during post-SCI days 21–42. No significant changes of these proteins were detected in the rostral region of the spinal cord.</p> <p>Conclusion</p> <p>Taken together, expression of NKCC1 and KCC2 proteins was differentially altered following SCI. The anti-hyperalgesic effect of NKCC1 inhibition suggests that normal or elevated NKCC1 function and loss of KCC2 function play a role in the development and maintenance of SCI-induced neuropathic pain.</p

    Australian bat lyssavirus infection in two horses

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    In May 2013, the first cases of Australian bat lyssavirus infections in domestic animals were identified in Australia. Two horses (filly-H1 and gelding-H2) were infected with the Yellow-bellied sheathtail bat (YBST) variant of Australian bat lyssavirus (ABLV). The horses presented with neurological signs, pyrexia and progressing ataxia. Intra-cytoplasmic inclusion bodies (Negri bodies) were detected in some Purkinje neurons in haematoxylin and eosin (H&amp;E) stained sections from the brain of one of the two infected horses (H2) by histological examination. A morphological diagnosis of sub-acute moderate non-suppurative, predominantly angiocentric, meningo-encephalomyelitis of viral aetiology was made. The presumptive diagnosis of ABLV infection was confirmed by the positive testing of the affected brain tissue from (H2) in a range of laboratory tests including fluorescent antibody test (FAT) and real-time PCR targeting the nucleocapsid (N) gene. Retrospective testing of the oral swab from (H1) in the real-time PCR also returned a positive result. The FAT and immunohistochemistry (IHC) revealed an abundance of ABLV antigen throughout the examined brain sections. ABLV was isolated from the brain (H2) and oral swab/saliva (H1) in the neuroblastoma cell line (MNA). Alignment of the genome sequence revealed a 97.7% identity with the YBST ABLV strain

    Multi-method approach shows stock structure in Loligo forbesii squid

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    Knowledge of stock structure is a priority for effective assessment of commercially-fished cephalopods. Loligo forbesii squid are thought to migrate inshore for breeding and offshore for feeding and long-range movements are implied from past studies showing genetic homogeneity in the entire neritic population. Only offshore populations (Faroe and Rockall Bank) were considered distinct. The present study applied mitchondrial and microsatellite markers (nine loci) to samples from Rockall Bank, north Scotland, North Sea, various shelf locations in Ireland, English Channel, northern Bay of Biscay, north Spain, and Bay of Cadiz. No statistically significant genetic sub-structure was found, although some non-significant trends involving Rockall were seen using microsatellite markers. Differences in L. forbesii statolith shape were apparent at a subset of locations, with most locations showing pairwise differences and statoliths from north Ireland being highly distinct. This suggests that (i) statolith shape is highly sensitive to local conditions and (ii) L. forbesii forms distinguishable groups (based on shape statistics), maintaining these groups over sufficiently long periods for local conditions to affect the shape of the statolith. Overall evidence suggests that L. forbesii forms separable (ecological) groups over short timescales with a semi-isolated breeding group at Rockall whose distinctiveness varies over time.Postprin
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