6,100 research outputs found
Effects of Propanidid and Thiopentone on the Acid-Base Status of Babies Delivered by Elective Caesarean Section
The effects of propanidid and thiopentone on the acidbase status of babies delivered by elective Caesarean section have been compared. The only significant difference between the 2 groups was the lower umbilical cord venous blood pCO) levels in the propanidid group. The acid-base status in both these groups of babies was not as good as in those delivered after induction delivery times of less than 6 minutes when thiopentone had been used as the induction agent. The clinical state of the babies in the propanidid group was superior to that in the thiopentone group, and at least equal to that of the group with the short induction-delivery interval.S. Afr. Med. J., 48, 1019 (1974
Bait uptake by wild badgers and its implications for oral vaccination against tuberculosis
This is the final version. Available from Public Library of Science via the DOI in this record.Data Availability: All relevant data are within the paper and its Supporting Information files.The deployment of baits containing vaccines or toxins has been used successfully in the management of wildlife populations, including for disease control. Optimisation of deployment strategies seeks to maximise uptake by the targeted population whilst ensuring cost-effectiveness. Tuberculosis (TB) caused by infection with Mycobacterium bovis affects a broad range of mammalian hosts across the globe, including cattle, wildlife and humans. The control of TB in cattle in the UK and Republic of Ireland is hampered by persistent infection in European badgers (Meles meles). The present study aimed to determine the best strategy for maximising uptake of an oral vaccine by wild badgers, using a surrogate novel bait deployed at 40 badger social groups. Baits contained a blood-borne biomarker (Iophenoxic Acid, IPA) in order to measure consumption in badgers subsequently cage trapped at targeted setts. Evidence for the consumption of bait was found in 83% (199/240) of captured badgers. The probability that badgers had consumed at least one bait (IPA >10 μg ml-1) was significantly higher following deployment in spring than in summer. Lower uptake amongst social groups where more badgers were captured, suggested competition for baits. The probability of bait consumption was significantly higher at groups where main and outlier setts were provided with baits than at those where outliers were present but not baited. Badgers captured 10–14 days post bait feeding had significantly higher levels of bait uptake compared to those caught 24–28 days later. Uptake rates did not vary significantly in relation to badger age and whether bait was placed above ground or down setts. This study suggests that high levels of bait uptake can be achieved in wild badger populations and identifies factors influencing the potential success of different deployment strategies. The implications for the development of an oral badger vaccine are discussed.Natural Environment Research Council (NERC)Animal and Plant Health Agency (APHA
The Vacuum in Light-Cone Field Theory
This is an overview of the problem of the vacuum in light-cone field theory,
stressing its close connection to other puzzles regarding light-cone
quantization. I explain the sense in which the light-cone vacuum is
``trivial,'' and describe a way of setting up a quantum field theory on null
planes so that it is equivalent to the usual equal-time formulation. This
construction is quite helpful in resolving the puzzling aspects of the
light-cone formalism. It furthermore allows the extraction of effective
Hamiltonians that incorporate vacuum physics, but that act in a Hilbert space
in which the vacuum state is simple. The discussion is fairly informal, and
focuses mainly on the conceptual issues. [Talk presented at {\sc Orbis
Scientiae 1996}, Miami Beach, FL, January 25--28, 1996. To appear in the
proceedings.]Comment: 20 pages, RevTeX, 4 Postscript figures. Minor typos correcte
A candidate redshift z ~ 10 galaxy and rapid changes in that population at an age of 500 Myr
Searches for very-high-redshift galaxies over the past decade have yielded a
large sample of more than 6,000 galaxies existing just 900-2,000 million years
(Myr) after the Big Bang (redshifts 6 > z > 3; ref. 1). The Hubble Ultra Deep
Field (HUDF09) data have yielded the first reliable detections of z ~ 8
galaxies that, together with reports of a gamma-ray burst at z ~ 8.2 (refs 10,
11), constitute the earliest objects reliably reported to date. Observations of
z ~ 7-8 galaxies suggest substantial star formation at z > 9-10. Here we use
the full two-year HUDF09 data to conduct an ultra-deep search for z ~ 10
galaxies in the heart of the reionization epoch, only 500 Myr after the Big
Bang. Not only do we find one possible z ~ 10 galaxy candidate, but we show
that, regardless of source detections, the star formation rate density is much
smaller (~10%) at this time than it is just ~200 Myr later at z ~ 8. This
demonstrates how rapid galaxy build-up was at z ~ 10, as galaxies increased in
both luminosity density and volume density from z ~ 8 to z ~ 10. The 100-200
Myr before z ~ 10 is clearly a crucial phase in the assembly of the earliest
galaxies.Comment: 41 pages, 14 figures, 2 tables, Nature, in pres
Impacts of removing badgers on localised counts of hedgehogs
This is the final version of the article. Available from Public Library of Science via the DOI in this record.Experimental evidence of the interactions among mammalian predators that eat or compete with one another is rare, due to the ethical and logistical challenges of managing wild populations in a controlled and replicated way. Here, we report on the opportunistic use of a replicated and controlled culling experiment (the Randomised Badger Culling Trial) to investigate the relationship between two sympatric predators: European badgers Meles meles and western European hedgehogs Erinaceus europaeus. In areas of preferred habitat (amenity grassland), counts of hedgehogs more than doubled over a 5-year period from the start of badger culling (from 0.9 ha-1 pre-cull to 2.4 ha-1 post-cull), whereas hedgehog counts did not change where there was no badger culling (0.3-0.3 hedgehogs ha-1). This trial provides experimental evidence for mesopredator release as an outcome of management of a top predator.The study was funded by the United Kingdom Government’s Department for Environment, Food and Rural Affairs (http://www.defra.gov.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Optimality program in segment and string graphs
Planar graphs are known to allow subexponential algorithms running in time
or for most of the paradigmatic
problems, while the brute-force time is very likely to be
asymptotically best on general graphs. Intrigued by an algorithm packing curves
in by Fox and Pach [SODA'11], we investigate which
problems have subexponential algorithms on the intersection graphs of curves
(string graphs) or segments (segment intersection graphs) and which problems
have no such algorithms under the ETH (Exponential Time Hypothesis). Among our
results, we show that, quite surprisingly, 3-Coloring can also be solved in
time on string graphs while an algorithm running
in time for 4-Coloring even on axis-parallel segments (of unbounded
length) would disprove the ETH. For 4-Coloring of unit segments, we show a
weaker ETH lower bound of which exploits the celebrated
Erd\H{o}s-Szekeres theorem. The subexponential running time also carries over
to Min Feedback Vertex Set but not to Min Dominating Set and Min Independent
Dominating Set.Comment: 19 pages, 15 figure
Piloting a parent and patient decision aid to support clinical trial decision making in childhood cancer
Objective: Families of a child with cancer can find the decision to enrol in a clinical trial challenging and often misunderstand key concepts that underpin trials. We pilot tested “Delta,” an online and booklet decision aid for parents with a child with cancer, and adolescents with cancer, deciding whether or not to enrol in a clinical trial. Methods: We developed Delta in accordance with the International Patient Decision Aid Standards. We conducted a pre-post pilot with parents with a child, and adolescents, who had enrolled in a paediatric phase III clinical trial for newly diagnosed acute lymphoblastic leukaemia. Parents (n = 37) and adolescents (n = 3) completed a questionnaire before and after using Delta (either the website or booklet, based on their preference). Results: Twenty-three parents (62.2%) and three adolescents (100%) reviewed the Delta website. Parents rated Delta as highly acceptable in regard to being clearly presented, informative, easy to read, useful, visually appealing, and easy to use. All participants reported that they would recommend Delta to others and that it would have been useful when making their decision. Parents' subjective (Mdiff=10.8, SDdiff = 15.69, P <.001) and objective (OR = 2.25, 95% CI, 1.66-3.04; P <.001) clinical trial knowledge increased significantly after reviewing Delta. Conclusions: To our knowledge, Delta is the first reported decision aid, available online and as a booklet, for parents and adolescents deciding whether or not to enrol in a paediatric oncology clinical trial. Our study suggests that Delta is acceptable, feasible, and potentially useful
The effects of seasonal changes on the dynamics of a fig tree's pollination
Fig trees and their pollinating wasps are mutually dependent on each other. Both partners' reproductive success is regulated by the capacity of fig wasps to enter receptive figs at an appropriate time for pollination and oviposition. Oviposition is dependent on successful female pollinator dispersal from one tree to another and although fig wasps are slow flyers and short-lived they can be carried long distances by the wind. The relative importance of local versus long-distance pollinator dispersal is unclear, as is how this may vary with season. In the highly seasonal environment of the Makana Botanical Gardens, Grahamstown, South Africa, we recorded fruiting phenologies of all the trees in a monoecious Ficus burtt-davyi Hutchinson population together with variation in the abundance of its pollinator Elisabethiella baijnathi Wiebes. By comparing captures of fig wasps flying in the air with the numbers that emerged locally, we also examined the independence of the fig tree population, which was separated from the nearest conspecifics by more than 1 km. The abundance of pollinators flying in the air and the number of fig wasps released by figs were correlated with temperature. During winter there were times when no pollinators were released locally; however, they were still caught in the traps, showing that the wasps had dispersed from elsewhere and that the population was not totally independent. These results highlight the ability of fig wasps to disperse between populations and the likely impact of seasonal fluctuations on fig tree gene flow
Testing special relativity with geodetic VLBI
Geodetic Very Long Baseline Interferometry (VLBI) measures the group delay in
the barycentric reference frame. As the Earth is orbiting around the Solar
system barycentre with the velocity of 30 km/s, VLBI proves to be a handy
tool to detect the subtle effects of the special and general relativity theory
with a magnitude of . The theoretical correction for the
second order terms reaches up to 300~ps, and it is implemented in the geodetic
VLBI group delay model. The total contribution of the second order terms splits
into two effects - the variation of the Earth scale, and the deflection of the
apparent position of the radio source. The Robertson-Mansouri-Sexl (RMS)
generalization of the Lorenz transformation is used for many modern tests of
the special relativity theory. We develop an alteration of the RMS formalism to
probe the Lorenz invariance with the geodetic VLBI data. The kinematic approach
implies three parameters (as a function of the moving reference frame velocity)
and the standard Einstein synchronisation. A generalised relativistic model of
geodetic VLBI data includes all three parameters that could be estimated.
Though, since the modern laboratory Michelson-Morley and Kennedy-Thorndike
experiments are more accurate than VLBI technique, the presented equations may
be used to test the VLBI group delay model itself.Comment: Proceedings of the IAG 2017 Scientific Meeting, Kobe, Japa
Bilateral posterior periventricular nodular heterotopia: a recognizable cortical malformation with a spectrum of associated brain abnormalities.
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