5,813 research outputs found
Novel use of stir bar sorptive extraction (SBSE) as a tool for isolation of oviposition site attractants for gravid Culex quinquefasciatus
Mosquitoes such as Culex quinquefasciatus Say (Diptera: Culicidae) are important vectors of organisms that cause disease in humans. Research into the development of effective standardized odour baits for blood-fed females (oviposition attractants), to enable entomological monitoring of vector populations, is hampered by complex protocols for extraction of physiologically active volatile chemicals from natural breeding site water samples, which have produced inconsistent results. Air entrainment and solvent extraction are technically demanding methods and are impractical for use in resource poor environments where mosquito-borne disease is most prevalent. This study reports the first use of a simple, robust extraction technique, stir bar sorptive extraction (SBSE), to extract behaviourally active small lipophilic molecules (SLMs) present in water samples collected from Cx. quinquefasciatus breeding sites in Tanzania. Extracts from a pit latrine and from a cess pool breeding site attracted more gravid Cx. quinquefasciatus in pair choice bioassays than control extracts, and coupled gas chromatography-electroantennography (GC-EAG) allowed tentative identification of 15 electrophysiologically active chemicals, including the known oviposition attractant, skatole (3-methylindole). Here, we have demonstrated, using simple pair choice bioassays in controlled laboratory conditions, that SBSE is effective for the extraction of behaviourally and electrophysiologically active semiochemicals from mosquito breeding site waters. Further research is required to confirm that SBSE is an appropriate technique for use in field surveys in the search for oviposition cues for Cx. quinquefasciatus
Zero mode quantization of multi-Skyrmions
A zero mode quantization of the minimal energy SU(2) Skyrmions for nucleon
numbers four to nine and seventeen is described. This involves quantizing the
rotational and isorotational modes of the configurations. For nucleon numbers
four, six and eight the ground states obtained are in agreement with the
observed nuclear states of Helium, Lithium and Beryllium. However, for nucleon
numbers five, seven, nine and seventeen the spins obtained conflict with the
observed isodoublet nuclear states.Comment: 37 pages, LaTeX, 4 figures. More careful treatment of double covers,
reference adde
D-Dimensional Radiative Plasma: A Kinetic Approach
The covariant kinetic approach for the radiative plasma, a mixture of a
relativistic moving gas plus radiation quanta (photons, neutrinos, or
gravitons) is generalized to D spatial dimensions. The operational and physical
meaning of Eckart's temperature is reexamined and the D-dimensional expressions
for the transport coefficients (heat conduction, bulk and shear viscosity) are
explicitly evaluated to first order in the mean free time of the radiation
quanta. Weinberg's conclusion that the mixture behaves like a relativistic
imperfect simple fluid (in Eckart's formulation) depends neither on the number
of spatial dimensions nor on the details of the collisional term. The case of
Thomson scaterring is studied in detail, and some consequences for higher
dimensional cosmologies are also discussed.Comment: 28 pages, 1 figure, uses REVTE
Operator Analysis for the Higgs Potential and Cosmological Bound on the Higgs-Boson Mass
Using effective lagrangian, we examine the impacts of new physics on the
electroweak baryogenesis. By analysing the high dimensional operators relevent
to the Higgs potential we point out that the Higgs mass bound required by
electroweak baryogenesis can be relaxed to the region allowed by experiments,
provided that new physics appears at the TeV scale.Comment: 10 Pages, Tex, UMDHEP 93-07
Low temperature spin fluctuations in geometrically frustrated Yb3Ga5O12
In the garnet structure compound Yb3Ga5O12, the Yb3+ ions (ground state
effective spin S' = 1/2) are situated on two interpenetrating corner sharing
triangular sublattices such that frustrated magnetic interactions are possible.
Previous specific heat measurements evidenced the development of short range
magnetic correlations below 0.5K and a lambda-transition at 54mK (Filippi et
al. J. Phys. C: Solid State Physics 13 (1980) 1277). From 170-Yb M"ossbauer
spectroscopy measurements down to 36mK, we find there is no static magnetic
order at temperatures below that of the lambda-transition. Below 0.3K, the
fluctuation frequency of the short range correlated Yb3+ moments progressively
slows down and as the temperature tends to 0, the frequency tends to a
quasi-saturated value of 3 x 10^9 s^-1. We also examined the Yb3+ paramagnetic
relaxation rates up to 300K using 172-Yb perturbed angular correlation
measurements: they evidence phonon driven processes.Comment: 6 pages, 5 figure
Exact solution (by algebraic methods) of the lattice Schwinger model in the strong-coupling regime
Using the monomer--dimer representation of the lattice Schwinger model, with
Wilson fermions in the strong--coupling regime (), we
evaluate its partition function, , exactly on finite lattices. By studying
the zeroes of in the complex plane for a large number of
small lattices, we find the zeroes closest to the real axis for infinite
stripes in temporal direction and spatial extent and 3. We find evidence
for the existence of a critical value for the hopping parameter in the
thermodynamic limit on the real axis at about . By looking at the behaviour of quantities, such as the chiral
condensate, the chiral susceptibility and the third derivative of with
respect to , close to the critical point , we find some indications
for a continuous phase transition.Comment: 22 pages (6 figures
Limits to Quantum Gravity Effects from Observations of TeV Flares in Active Galaxies
We have used data from the TeV gamma-ray flare associated with the active
galaxy Markarian 421 observed on 15 May 1996 to place bounds on the possible
energy-dependence of the speed of light in the context of an effective quantum
gravitational energy scale. The possibility of an observable time dispersion in
high energy radiation has recently received attention in the literature, with
some suggestions that the relevant energy scale could be less than the Planck
mass and perhaps as low as 10^16 GeV. The limits derived here indicate this
energy scale to be in excess of 4x10^16 GeV at the 95% confidence level. To the
best of our knowledge, this constitutes the first convincing limit on such
phenomena in this energy regime.Comment: 6 pages, including 2 figure
Dynamical Viscosity of Nucleating Bubbles
We study the viscosity corrections to the growth rate of nucleating bubbles
in a first order phase transition in scalar field theory. We obtain the
non-equilibrium equation of motion of the coordinate that describes small
departures from the critical bubble and extract the growth rate consistently in
weak coupling and in the thin wall limit. Viscosity effects arise from the
interaction of this coordinate with the stable quantum and thermal fluctuations
around a critical bubble. In the case of 1+1 dimensions we provide an estimate
for the growth rate that depends on the details of the free energy functional.
In 3+1 dimensions we recognize robust features that are a direct consequence of
the thin wall approximation and give the leading viscosity corrections.These
are long-wavelength hydrodynamic fluctuations that describe surface waves,
quasi-Goldstone modes which are related to ripples on interfaces in phase
ordered Ising-like systems. We discuss the applicability of our results to
describe the growth rate of hadron bubbles in a quark-hadron first order
transition.Comment: 40 pages, 4 figures, revtex, minor changes, to be published in Phys.
Rev.
Physio4FMD: protocol for a multicentre randomised controlled trial of specialist physiotherapy for functional motor disorder
Background
Patients with functional motor disorder (FMD) experience persistent and disabling neurological symptoms such as weakness, tremor, dystonia and disordered gait. Physiotherapy is usually considered an important part of treatment; however, sufficiently-powered controlled studies are lacking. Here we present the protocol of a randomised controlled trial (RCT) that aims to evaluate the clinical and cost effectiveness of a specialist physiotherapy programme for FMD.
Methods/design
The trial is a pragmatic, multicentre, single blind parallel arm randomised controlled trial (RCT). 264 Adults with a clinically definite diagnosis of FMD will be recruited from neurology clinics and randomised to receive either the trial intervention (a specialist physiotherapy protocol) or treatment as usual control (referral to a community physiotherapy service suitable for people with neurological symptoms). Participants will be followed up at 6 and 12âmonths. The primary outcome is the Physical Function domain of the Short Form 36 questionnaire at 12âmonths. Secondary domains of measurement will include participant perception of change, mobility, health-related quality of life, health service utilisation, anxiety and depression. Health economic analysis will evaluate the cost impact of trial and control interventions from a health and social care perspective as well as societal perspective.
Discussion
This trial will be the first adequately-powered RCT of physical-based rehabilitation for FMD.
Trial registration
International Standard Randomised Controlled Trials Number ISRCTN56136713. Registered 27 March 2018
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