136 research outputs found
Photon-echo quantum memories in inhomogeneously broadened two-level atoms
No full textHere, we propose a solid-state quantum memory that does not require spectral holeburning, instead using strong rephasing pulses like traditional photon-echo techniques. The memory uses external broadening fields to reduce the optical depth and so switch off the collective atom-light interaction when desired. The proposed memory should allow operation with reasonable efficiency in a much broader range of material systems, for instance Er3+ doped crystals which have a transition at 1.5 μm. We present analytic theory supported by numerical calculations and initial experiments
Does looped nasogastric tube feeding improve nutritional delivery for patients with dysphagia after acute stroke? A randomised controlled trial
No full textBackground: nasogastric tube (NGT) feeding is commonly used after stroke, but its effectiveness is limited by frequent dislodgement.Objective: the objective of the study was to evaluate looped NGT feeding in acute stroke patients with dysphagia.Methods: this was a randomised controlled trial of 104 patients with acute stroke fed by NGT in three UK stroke units. NGT was secured using either a nasal loop (n = 51) or a conventional adhesive dressing (n = 53). The main outcome measure was the proportion of prescribed feed and fluids delivered via NGT in 2 weeks post-randomisation. Secondary outcomes were frequency of NGT insertions, treatment failure, tolerability, adverse events and costs at 2 weeks; mortality; length of hospital stay; residential status; and Barthel Index at 3 months.Results: participants assigned to looped NGT feeding received a mean 17% (95% confidence interval 5-28%) more volume of feed and fluids, required fewer NGTs (median 1 vs 4), and had fewer electrolyte abnormalities than controls. There was more minor nasal trauma in the loop group. There were no differences in outcomes at 3 months. Looped NGT feeding cost 88 pounds sterling more per patient over 2 weeks than controls.Conclusion: looped NGT feeding improves delivery of feed and fluids and reduces NGT reinsertion with little additional cost.</p
National infrastructure assessment: Analysis of options for infrastructure provision in Great Britain, Interim results
No full textDecisions about infrastructure are long term commitments: wrong choices now could lead to future failures, and/or lock-in for future generations to inappropriate infrastructure systems, with high debts and maintenance costs and could also have important implications for sustainability. Thus we need a long term approach to analysing the options for national infrastructure provision across a wide range of plausible futures. That, however, is a complex technical task – much easier said than done. It involves understanding the drivers of demand for infrastructure services in the future and the ways in which the different infrastructure networks might cope with, and respond to that demand. The aim of the Infrastructure Transitions Research Consortium (ITRC) programme is to deliver that modelling capability for the UK.The ITRC has now developed an integrated system-of-systems model (NISMOD) that can simulate the long term performance of infrastructure networks in Great Britain. This analysis capability has been used to compare alternative long term strategies for infrastructure provision. In total we have examined 17 different options for infrastructure provision, to be implemented over the coming decades, under a wide range of scenarios of future demographic change, economic growth and climate change. This report presents interim results from that new analysis, helping to evaluate and compare alternative strategies for national infrastructure provision. For the first time this report demonstrates how long term, cross-sectoral plans for infrastructure provision at a national scale can be mapped out and analysed.The results reported here are interim and subject to change. ITRC analysis of national infrastructure systems continues. A book with more complete description of the methodology and results reported here will be published by Cambridge University Press in 2014. In addition, further research to improve the NISMOD model and its application to Britain’s national infrastructure is planned for 2014–2015, thanks to support from the Engineering and Physical Sciences Research Counci
Changes in hot spring temperature and hydrogeology of the Alpine Fault hanging wall, New Zealand, induced by distal South Island earthquakes
No full textThermal springs in the Southern Alps, New Zealand, originate through penetration of fluids into a thermal anomaly generated by rapid uplift and exhumation on the Alpine Fault. Copland hot spring (43.629S, 169.946E) is one of the most vigorously flowing, hottest of the springs, discharging strongly effervescent CO2-rich 56–58°C water at 6 ± 1 litre sec-1. Shaking from the Mw7.8 Dusky Sound (Fiordland) 2009 and Mw7.1 Darfield (Canterbury) 2010 earthquakes, 350 and 180 km from the spring, respectively, resulted in a characteristic approximately 1°C delayed cooling over 5 days. A decrease in conductivity and increase in pH were measured following the Mw7.1 Darfield earthquake. Earthquake-induced decreases in Cl, Li, B, Na, K, Sr and Ba concentrations and an increase in SO4 concentration reflect higher proportions of shallow-circulating meteoric fluid mixing in the subsurface. Shaking at amplitudes of approximately 0.5% g Peak Ground Acceleration (PGA) and/or 0.05–0.10 MPa dynamic stress influences Copland hot spring temperature, which did not respond during the Mw6.3 Christchurch 2011 aftershock or other minor earthquakes. Such thresholds should be exceeded every 1–10 years in the central Southern Alps. The characteristic cooling response at low shaking intensities (MM III–IV) and seismic energy densities (approximately 10?1 J m?3) from intermediate-field distances was independent of variations in spectral frequency, without the need for post-seismic recovery. Observed temperature and fluid chemistry responses are inferred to reflect subtle changes in the fracture permeability of schist mountains adjacent to the spring. Permanent 10-7–10-6 strains recorded by cGPS reflect opening or generation of fractures, allowing greater quantities of relatively cool near-surface groundwater to mix with upwelling hot water. Active deformation, tectonic and topographic stress in the Alpine Fault hanging wall, where orographic rainfall, uplift and erosion are extreme, make the Southern Alps hydrothermal system particularly susceptible to earthquake-induced transient permeability
Fault Location and Slip Distribution of the 22 February 2011 Mw 6.2 Christchurch, New Zealand, Earthquake from Geodetic Data
No full textReconnecting whānau: Pathways to recovery for Māori with bipolar disorder
No full textWhile Māori are known to experience a higher burden of mental health and addiction problems compared to non-Māori (Baxter, 2008), little exploratory research has been conducted into Māori experiences of bipolar affective disorder. Bipolar disorder is at times regarded as a “life sentence”, with little hope of recovery. The recovery- focused mental health literature, however, argues wellness is achievable for even the most intractable conditions (Lapsley, Nikora, & Black, 2002; Mental Health Commission, 2001). The aim of this research was to gather information about the experiences of Māori who were diagnosed with bipolar affective disorder. Interviews were conducted with 22 Māori wāhine (women) and tāne (men), and using thematic analyses, themes relevant to their life stories were uncovered. This research sought to contribute to the realisation of Māori potential by explicitly shifting from deficit- focused frameworks to a focus on systemic factors that influenced Māori wellbeing. Highlights were that whānau (participants) who were connected with friends, partners and family were motivated to achieve wellness and to stay well
Validation of precipitable water from ECMWF model analyses with GPS and radiosonde data during the MAP SOP
No full textPrecipitable water vapour contents (PWCs) from European Centre for Medium-Range Weather Forecasts (ECMWF) analyses have been compared with observations from 21 ground-based Global Positioning System receiving stations (GPS) and 14 radiosonde stations (RS), covering central Europe, for the period of the Mesoscale Alpine Programme experiment special observing period (MAP SOP). Two model analyses are considered: one using only conventional data, serving as a control assimilation experiment, and one including additionally most of the non-operational MAP data. Overall, a dry bias of about −1 kg m−2 (−5.5% of total PWC), with a standard deviation of ∼2.6 kg m−2 (13% of total PWC), is diagnosed in both model analyses with respect to GPS. The bias at individual sites is quite variable: from −4 to ∼0 kg m−2. The largest differences are observed at stations located in mountainous areas and/or near the sea, which reveal differences in representativeness. Differences between the two model analyses, and between these analyses and GPS, are investigated in terms of usage and quality of RS data. Biases in RS data are found from comparisons with both model and GPS PWCs. They are confirmed from analysis feedback statistics available at ECMWF. An overall dry bias in RS PWC of 4.5% is found, compared to GPS. The detection of RS biases from comparisons both with the model and GPS indicates that data screening during assimilation was generally effective. However, some RS bias went into the model analyses. Inspection of the time evolution of PWC from the model analyses and GPS occasionally showed differences of up to 5–10 kg m−2. These were associated with severe weather events, with variations in the amount of RS data being assimilated, and with time lags in the PWCs from the two model analyses. Such large differences contribute strongly to the overall observed standard deviations. Good confidence in GPS PWC estimates is gained through this work, even during periods of heavy rain. These results support the future assimilation of GPS data, both for operational weather prediction and for mesoscale simulation studies
The dynamics of reactivated landslides: Utiku and Taihape, North Island, New Zealand
No full textThe primary aim of this research was to study the relationship between landslide motion and its causes, with reference to large, slow moving, reactivated translational rock slides. The movement of such slides has often been assumed to be uniform over time because poor temporal and spatial monitoring resolutions have not allowed the processes and mechanisms governing the velocity to be identified. The increased spatial and temporal resolution of the monitoring carried out for this research allows these processes to be better understood.
Two deep-seated, reactivated translational slides were selected to represent over 7,000 mapped landslides of this type in Tertiary-age sedimentary rocks of New Zealand. Each was closely monitored with an automated network of instruments to detect and measure the effects of rainfall, pore pressure, earthquakes and river stage on changing surface and subsurface movement patterns, with sufficient resolution to link periods of movement to their triggering factors. The dynamics and controls upon these landslides have been investigated by combining multiple interdisciplinary approaches including geology, geomorphology, geotechnics and geomatics. Without such an approach the mechanisms governing their motion could not have been adequately resolved.
The deformation behaviour at the two slides during the period of observation would best be described as episodic post-failure creep. The creep patterns observed typically comprised periods of accelerated-, slow- and vertical-creep, punctuated by intervals of rest, which recurred both seasonally and independent of season. Three systems were identified within the recorded unsteady, non-uniform motion: 1) basal sliding; 2) internal plastic deformation and basal sliding; and 3) seasonal surficial shrinkage and swelling unrelated to landsliding. Basal sliding by frictional slip along thin clay seams led to the largest horizontal displacements recorded at both landslides. However, once triggered by pore-pressure increase, accelerated-creep motion by basal sliding did not tend to arrest when basal pore pressure decreased. At both landslides slow horizontal- and vertical-creep occurred together over much of the monitoring period and was related to plastic deformation of the slide mass and basal sliding. This motion occurred at a constant velocity and did not vary with fluctuating pore pressure. Accelerated- and slow-creep motion was regulated by the geometrical complexity of the landslide mass rather than basal pore-pressure-induced increases in shear resistance, or rate-induced increases in material shear resistance
Yponomeuta alexi Agassiz 2019, sp. nov.
No full text10. Yponomeuta alexi sp. nov. Description of adult (Plate 2). Wingspan 15–18 mm. Head pale brown mixed whitish, labial palpus whitish, some brownish scales laterally, segment 3 slightly longer than segment 2; scape mixed pale brown and brown, flagellum indistinctly annulate pale fuscous and fuscous. Thorax brownish white with a blackish triangular central spot, tegula brownish-white, dark brown anteriorly. Forewing pale brown, white dorsally, whith a scattering of fuscous and pale fuscous scales, less in the terminal area; a blackish elongate spot in fold just before middle, a further blackish mark in apical fringe. Hindwing pale greyish-brown. Legs and abdomen greyish brown, sternums with a mixture of small spines and microtrichia. Male genitalia (Plate 9). Socius long, broadened before tapering to apex which has two small spines, uncus square, valva with costa straight, basal area spined, outer half covered with hairs, dorsum pointed with a cluster of small spines; saccus curved downwards with a slightly bulbous end. Aedeagus about twice length of valva, cornutus occupying ¾ of its length. Female genitalia (Plate 19). Lamella postvaginalis small with lobes close together, separated by a small Ushaped incision, ostium slightly bulbous, antrum straight and tapering, ductus bursae with a scobinate patch extending to ¼ of its length, corpus bursae ovoid without signum; bursae together about ¾ length of abdomen. Diagnosis. Differs from other species in having narrow forewing, paler in the dorsal half interrupted by a partial fascia; in the male genitalia by the valva having spines at the tornus. Biology. Not known, adults recorded in October and November. The larva is illustrated on Plate 28. Derivation of the name. Named after my grandson Alex. Distribution. Kenya, known only from the northern and western slopes of Mt Kenya. Type material. Holotype ♂ KENYA: Eastern, Lewa 2050 m, 0°8’24.5’’N 37°27’23.8’’E 1.xi.2013, Agassiz, Beavan, Heckford & Larsen. 11 paratypes: 3 ♂ 4 ♀ same data as holotype, including slides DA1328, 1330 and 1599; 2 ♀ same locality as holotype, 31.x.2013; 2 ♀ Naro Moru, 1960 m, 0°9’5’’S 37°0’36’’E 4.xi.2013 Agassiz, Beavan, Heckford, Larsen & Ngugi (DJLA).Published as part of Agassiz, David J. L., 2019, The Yponomeutidae of the Afrotropical region (Lepidoptera: Yponomeutoidea), pp. 1-69 in Zootaxa 4600 (1) on page 12, DOI: 10.11646/zootaxa.4600.1.1, http://zenodo.org/record/400039
Factors Influencing 14C Ages of the Pacific Rat Rattus exulans
No full textFrom the 16th International Radiocarbon Conference held in Gronigen, Netherlands, June 16-20, 1997.An isotopic database for the Pacific/Polynesian rat (Rattus exulans) and foods that it scavenges is used to examine diet-induced 14C age variation in omnivores. We discuss a suite of 26 Delta-14C determinations and 13C and 15N analysis for modern Pacific/Polynesian rat bone gelatin and available food items from Kapiti Island, New Zealand (40 degrees 51'S, 174 degrees 75'E). These analyses provide the first isotopic data for modern specimens of the species, collected as part of a larger project to determine potential sources of bias in unexpectedly old 14C age measurements on subfossil specimens of R. Exulans from New Zealand. Stable C, N and 14C isotopic and trapping data are used to trace carbon intake via the diet of the rats in each habitat. Data from specimens linked to five specific habitats on the island indicate that modern populations of R. Exulans are not in equilibrium with atmospheric values of Delta-14C, being either enriched or depleted relative to the atmospheric curve in 1996/97, the period of collection. The Delta-14C values recorded for R. Exulans are associated with diet, and result from variation in Delta-14C values found in animal-protein food items available to a scavenging omnivore. The titer of carbon deviating from atmospheric values is believed to be derived from the essential amino acids in the protein-rich foods of the rat diet. Present evidence suggests that the depletion required to affect 14C ages limits the possibility that diet introduces dramatic offsets from true ages. Marine diets, for example, would have a variable effect on ages for terrestrial omnivores, contraindicating the application of a standard marine correction for such specimens. We suggest that to identify the extent to which diet may influence the 14C age in a given specimen of terrestrial omnivore, the separation and dating of essential amino acids vs. A nonessential amino, such as glycine, be applied.This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
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