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Dally flux density measurements of 36 extragalactic radio sources over a seven year period, obtained by the Green Bank interferometer, reveal several unusual minima in the light curves that do not follow typical source variations (Fiedler et al. 1987). The most significant departure from typical source variability occurred at both frequencies in the quasar 0954+658 between 1980.95 and 1981.3. Refractive focussing by small scale inhomogeneities in an ionized structure in the interstellar medium appears to be the most likely explanation.
Ray tracing numerical simulations of extreme scattering events result in light curves that display many of the qualitative features observed in such events. The apparent images of an affected source show strong and variable distortions, which could be readily discerned with VLBI observations.
Thrips palmi and Frankliniella occidentalis (order Thysanoptera) are thrips species that represent major plant pests. They are polyphagous insects capable of adversely affecting crop production. As such, in the European Union, these thrips species should be regulated as quarantine organisms. T. palmi and F. occidentalis can cause considerable damage to susceptible plants by feeding on them and transmitting several viruses responsible for serious plant diseases. Successful pest control strategies are based on an early, fast, and reliable diagnosis, which precedes the selection of appropriate steps to limit the effects of harmful organisms. We herein describe a novel diagnostic approach that enables the sensitive and species-specific detection (and differentiation) of these pests in a duplex polymerase chain reaction assay, which was adapted for both standard and real-time quantitative assays. Our method is based on the amplification of a 5.8S-internal transcribed spacer 2 ribosomal DNA fragment that is conserved between T. palmi and F. occidentalis.
Clinical practice guidelines are not easily implemented, leading to a gap between research synthesis and their use in routine care.
To summarise the evidence relating to the impact of guideline implementation on provider performance and patient outcomes in mental healthcare settings, and to explore the performance of different strategies for guideline implementation.
A systematic review of randomised controlled trials, controlled clinical trials and before-and-after studies comparing guideline implementation strategies v. usual care, and different guideline implementation strategies, in patients with severe mental illness.
In total, 19 studies met our inclusion criteria. The studies did not show a consistent positive effect of guideline implementation on provider performance, but a more consistent small to modest positive effect on patient outcomes.
Guideline implementation does not seem to have an impact on provider performance, nonetheless it may influence patient outcomes positively.
We report multifrequency observations of the γ-ray blazar 0528+134 with the Effelsberg 100-m telescope, the IRAM 30-m telescope at Pico Veleta and the NRL Green Bank Interferometer. The observing methods are described elsewhere (Reich et al., 1993; Pohl et al., 1995). The radio lightcurves are given in Fig.1 in comparison to the status of 0528+134 in the EGRET energy range. The uncertainties in the flux densities quoted there are less than 5% at 10.55 GHz and lower frequencies, while slightly exceeding this value at 32 GHz and 86 GHz.
Characteristic frequencies of some modes of radial pulsations and their relative displacements have been determined for a sequence of composite polytropic stellar models having an inner zone of index n = 1 and an envelope n = 5. It is demonstrated that vibrational stability increases with the degree of central condensation of the individual two zone models.
Expressions for the physical structure of a sequence of two zone polytropic stellar models, based on composite analytical solutions of the Lane-Emden equation with indices n = 1 and n = 5, hâve been determined. The coefficients of vibrational stability for radial oscillations of this sequence of models have also been calculated and it is found that increasing the extent of the n = 5 outer zone has a stabilizing effect.
Linear stability theory for Rayleigh-Benard convection shows that for a specified Rayleigh number, greater than some critical value, only a finite range of horizontal wave numbers support convective instability in a horizontal layer of fluid heated from below. However, it is not possible to predict the preferred horizontal scale of established motions from this approach although it is clear from observations, particularly of the solar surface, that a preferred cell size does prevail. In an endeavour to establish a preferred horizontal scale appropriate non-linear modal equations have been integrated forward in time, initially incorporating a discrete band of wave numbers equally spaced across the range that supports convection, for a specific Rayleigh number. The horizontal resolution was improved in subsequent integrations by first deleting modes that had substantially decayed and then introducing new modes on a finer horizontal mesh in the vicinity of what appeared to be the evolutionary dominant mode. Finally, the multimode integrations were continued in time until the evolution of a dominant horizontal mode from within the restricted range was evident. Both the model characteristics and numerical scheme adopted placed limits on the degree of horizontal refinement that could be undertaken with confidence.
The proposed Fast All Sky Telescope (FAST) is an interferometer which is intended to monitor the northern four-fifths of the celestial sphere every two days at 8.1 GHz and daily at 2.7 GHz. The design goal is to have a rms sensitivity of 10 mJy/beam at both frequencies. The array is planned to comprise 20 3-meter diameter antennas with a maximum baseline of 0.7 km. FAST will provide a valuable database that may be used to study time variability in a sensitivity limited sample of radio sources. This will significantly impact on the understanding of active Galactic and extragalactic radio sources, as well as on the understanding of radio wave scattering in the interstellar medium.
P/1996 N2 Elst-Pizarro was discovered with a tail of dust in July 1996 and was thus classified as periodic comet. From the orbit point of view it belongs to the outer asteroid belt and is very likely a member of the Themis family, a group of bodies originating from an asteroid collision.
The absence of a coma and the presence of the needle-like anti-tail in August 1996 did not exclude the possibility of a sudden emission event which could have been caused by the impact of another minor body on the object. However, with the development of a normal tail between September and November 1996 it became obvious that the dust emission episode continued at least for 2 months after perihelion, a scenario that is typical for gas-driven cometary activity. However, it is still possible that a collision triggered the event.
The paper summarizes the observational pro and cons for impact-induced activity in this object, possibly the first ever detected comet-asteroid of the solar system.
Lepidopteran caterpillars are typically classified as herbivorous insects. Other feeding associations have been known for a long time but are often neglected in the ecological literature. In samples from 194 shrubs belonging to 16 species of Piperaceae and Asteraceae, which were taken in a montane forest and succession habitats in southern Ecuador, caterpillar assemblages included an unexpectedly large fraction not feeding on the living biomass of their putative ‘host’. Feeding trials revealed them to instead feed on foliose lichens, dead leaves and epiphylls (lichen, algae, bryophytes). These ‘alternative feeders’ accounted for 22.5% of the whole dataset and up to 80% of the caterpillars on individual plant species. Densities of alternative feeders were very similar across shrub species within each plant family, but differed strongly between Asteraceae in succession and Piperaceae in forest habitats. Herbivore caterpillars showed the opposite pattern with strong differences between individual plant species, but overall similar densities on both plant families.
The prevalence of maternal anaemia remains unacceptably high in developing countries. At the same time, the percentage of women who consume one or more Fe+folic acid (IFA) tablets during pregnancy remains persistently low. The objective of the present study was to identify where, within antenatal care (ANC) programmes, pregnant women falter in obtaining and consuming an ideal minimum of 180 IFA tablets.
Data from Demographic and Health Surveys were used to develop a schematic which identifies four sequential ‘falter points’ to consuming 180 IFA tablets: ANC attendance, IFA receipt or purchase, IFA consumption and the number of tablets consumed.
Twenty-two countries with high burdens of undernutrition.
A sample of 162 958 women, 15 to 49 years of age, with a live birth in the past 5 years.
Across all countries, 83 % of all pregnant women had at least one ANC visit, 81 % of whom received IFA tablets. Of those receiving IFA tablets, 95 % consumed at least one. Overall adherence to the ideal supplementation regimen, however, was extremely low: only 8 % consumed 180 or more IFA tablets. There were only two countries in which the percentage of pregnant women consuming 180 or more tablets exceeded 30 %.
While most women receive and take some IFA tablets, few receive or take enough. The analysis identifies where ANC-based distribution of IFA falters in each country. It enables policy makers to design and prioritize follow-up activities to more precisely identify barriers, an essential next step to improving IFA distribution through ANC.
Predation pressure is essential in regulating population dynamics of herbivorous insects. We used artificial caterpillars (25 × 4 mm) made from brown-or green-coloured plasticine to compare predation pressure between countryside and near-natural rain-forest habitat in the Gulfo Dulce region (Costa Rica). Within each habitat, 162 caterpillars were placed randomly on different substrates along a 1200-m transect and at heights between 0.5 and 2.0 m. Artificial caterpillars were inspected at 24-h intervals for 3 consecutive days. Predation pressure was almost twice as high for countryside (mean attack frequency per capita: 1.11 ± 0.08 SE) compared with rain forest (0.66 ± 0.07 SE). In both habitats arthropods emerged as chief predator group, followed by birds. Attacks by non-volant mammals were very rare and restricted to rain-forest sites. In the countryside, bird attacks were more than four times as common as in forest, indicating a change in their relative importance across habitats.
Vitamin A deficiency is a serious health problem in Bangladesh. The 2011–12 Bangladesh Micronutrient Survey found 76·8 % of children of pre-school age were vitamin A deficient. In the absence of nationally representative, individual dietary assessment data, we use an alternative – household income and expenditure survey data – to estimate the potential impact of the introduction of vitamin A-fortified vegetable oil in Bangladesh.
Items in the household income and expenditure survey were matched to food composition tables to estimate households’ usual vitamin A intakes. Then, assuming (i) the intra-household distribution of food is in direct proportion to household members’ share of the household’s total adult male consumption equivalents, (ii) all vegetable oil that is made from other-than mustard seed and that is purchased is fortifiable and (iii) oil fortification standards are implemented, we modelled the additional vitamin A intake due to the new fortification initiative.
Nationwide in Bangladesh.
A weighted sample of 12240 households comprised of 55580 individuals.
Ninety-nine per cent of the Bangladesh population consumes vegetable oil. The quantities consumed are sufficiently large and, varying little by socio-economic status, are able to provide an important, large-scale impact. At full implementation, vegetable oil fortification will reduce the number of persons with inadequate vitamin A intake from 115 million to 86 million and decrease the prevalence of inadequate vitamin A intake from 80 % to 60 %.
Vegetable oil is an ideal fortification vehicle in Bangladesh. Its fortification with vitamin A is an important public health intervention.