35,339 research outputs found
Tools for Risk Analysis: Updating the 2006 WHO guidelines
This chapter reviews developments since the WHO Guidelines for the safe use of wastewater in agriculture were published in 2006. The six main developments are: the recognition that the tolerable additional disease burden may be too stringent for many developing countries; the benefits of focusing on single-event infection risks as a measure of outbreak potential when evaluating risk acceptability; a more rigorous method for estimating annual risks; the availability of dose-response data for norovirus; the use of QMRA to estimate Ascaris infection risks; and a detailed evaluation of pathogen reductions achieved by produce-washing and disinfection. Application of the developments results in more realistic estimates of the pathogen reductions required for the safe use of wastewater in agriculture and consequently permits the use of simpler wastewater treatment processes
Variational derivation of two-component Camassa-Holm shallow water system
By a variational approach in the Lagrangian formalism, we derive the
nonlinear integrable two-component Camassa-Holm system (1). We show that the
two-component Camassa-Holm system (1) with the plus sign arises as an
approximation to the Euler equations of hydrodynamics for propagation of
irrotational shallow water waves over a flat bed. The Lagrangian used in the
variational derivation is not a metric.Comment: to appear in Appl. Ana
Adaptive segmentation of textured images by using the coupled Markov random field model
Author name used in this publication: (David) Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
A knowledge-based image smoothing technique for dynamic PET studies
Author name used in this publication: Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information EngineeringRefereed conference paper2000-2001 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Morphology-based multifractal estimation for texture segmentation
Author name used in this publication: (David) Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Linear confinement without dilaton in bottom-up holography for walking technicolour
In PRD78(2008)055005 [arXiv:0805.1503 [hep-ph]] and PRD79(2009)075004
[arXiv:0809.1324 [hep-ph]], we constructed a holographic description of walking
technicolour theories using both a hard- and a soft-wall model. Here, we show
that the dilaton field becomes phenomenologically irrelevant for the spectrum
of spin-one resonances once a term is included in the Lagrangian that mixes the
Goldstone bosons and the longitudinal components of the axial vector mesons. We
show how this mixing affects our previous results and we make predictions about
how this description of technicolour can be tested.Comment: 7 pages, no figure
THE EFFECT OF THREE PRETREATMENTS ON BREAKING SEED DORMANCY OF BAOBAB (ADANSONIA DIGITATA L.)
Objective: Baobab (Adansonia digitata) is a native tree that is found in African savannas, it is a member of family ‘Malvaceae’. The tree is found in Nigeria, South Africa, Botswana, Namibia, Mozambique and in different regions of western Madagascar. Seed dormancy is the most limiting factor for some plants propagation. Dormancy allows seeds to separate from their mother plant and survive dispersal, over distance, and time before growth recommences. This study was aimed to determine the effect of three pre-treatments on breaking the seed dormancy of Adansonia digitata L., a multi-purpose and indigenously endangered tree.
Methods: The study was carried out in the greenhouse of the Department of Biological Sciences, Federal University Dutsin-Ma, Nigeria. The three pre-treatments are: Soaking in hot water (100°C) for 5, 10, 15, and 20 min; and soaking in sulfuric acid (H2SO4) and hydrochloric acid (HCL) concentrations (100%, 75%, 50%, and 25%) for 5, 10, 15, and 20 min. Untreated seeds served as control. These were laid out in a complete randomized design with three replications. Data were collected on germination percentage, germination rate, day of emergence, and the average seedlings height.
Results: The result showed that earliest mean days of emergence (7 days) were observed in seeds subjected to hot water treatment at 15 min. It also showed the highest rate of germination and percentage 6 (100%). On the other hand, the effect of acids (H2SO4 and HCL) pre-treatments on the seeds gave a fair result (16.66–33.33%), untreated seeds did not germinate.
Conclusion: All the pre-treatments used in the study were found to be effective. However, soaking of seeds in hot water (100°C) pre-treatment for 15 min is recommended for breaking the seed dormancy of A. digitata
Developing and evaluating a five minute phishing awareness video
Confidence tricksters have always defrauded the unwary. The computer era has merely extended their range and made it possible for them to target anyone in the world who has an email address. Nowadays, they send phishing messages that are specially crafted to deceive. Improving user awareness has the potential to reduce their effectiveness. We have previously developed and empirically-validated phishing awareness programmes. Our programmes are specifically designed to neutralize common phish-related misconceptions and teach people how to detect phishes. Many companies and individuals are already using our programmes, but a persistent niggle has been the amount of time required to complete the awareness programme. This paper reports on how we responded by developing and evaluating a condensed phishing awareness video that delivered phishing awareness more efficiently. Having watched our video, participants in our evaluation were able to detect phishing messages significantly more reliably right after watching the video (compared to before watching the video). This ability was also demonstrated after a retention period of eight weeks after first watching the video
Holographic Conformal Window - A Bottom Up Approach
We propose a five-dimensional framework for modeling the background geometry
associated to ordinary Yang-Mills (YM) as well as to nonsupersymmetric gauge
theories possessing an infrared fixed point with fermions in various
representations of the underlying gauge group. The model is based on the
improved holographic approach, on the string theory side, and on the
conjectured all-orders beta function for the gauge theory one. We first analyze
the YM gauge theory. We then investigate the effects of adding flavors and show
that, in the holographic description of the conformal window, the geometry
becomes AdS when approaching the ultraviolet and the infrared regimes. As the
number of flavors increases within the conformal window we observe that the
geometry becomes more and more of AdS type over the entire energy range.Comment: 20 Pages, 3 Figures. v2: references adde
A gauge invariant chiral unitary framework for kaon photo- and electroproduction on the proton
We present a gauge invariant approach to photoproduction of mesons on
nucleons within a chiral unitary framework. The interaction kernel for
meson-baryon scattering is derived from the chiral effective Lagrangian and
iterated in a Bethe-Salpeter equation. Within the leading order approximation
to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and
CBELSA/TAPS are analyzed in the threshold region. The importance of gauge
invariance and the precision of various approximations in the interaction
kernel utilized in earlier works are discussed.Comment: 23 pages, 13 figs, EPJ A styl
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