2,245 research outputs found
Dispersal of _Aedes aegypti_: field study in temperate areas and statistical approach
We studied the dispersion of _Aedes aegypti_ during egg laying in natural conditions. Two independent experiments involving mosquitoes dispersing from urbanization towards adjacent un-urbanized areas were carried out and analyzed in statistical terms. We find relations between stochastic variables related to the egg laying mosquito activity (ELMA), useful to assess dispersion probabilities, despite the lack of knowledge of the total number of ovipositions in the zone. We propose to evaluate the activity as minus the logarithm of the fraction of negative ovitraps at different distances from buildings. We also estimate the average number of eggs laid per oviposition using a regression between the ELMA and the number of eggs found. Three zones with different oviposition activity were determined: a corridor surrounding the urbanized area, a second region between 10m and 25m and the third region extending from 30m to 45m from the urbanization. The landscape (plant cover) and the human activity in the area appear to have an influence in the dispersal of _Aedes aegypti_
Contamination
Soil contamination occurs when substances are added to soil, resulting in increases in concentrations
above background or reference levels. Pollution may follow from contamination when contaminants
are present in amounts that are detrimental to soil quality and become harmful to the environment or
human health. Contamination can occur via a range of pathways including direct application to land and
indirect application from atmospheric deposition.
Contamination was identified by SEPA (2001) as a significant threat to soil quality in many parts of
Scotland. Towers et al. (2006) identified four principal contamination threats to Scottish soils: acidification;
eutrophication; metals; and pesticides. The Scottish Soil Framework (Scottish Government, 2009) set out
the potential impact of these threats on the principal soil functions.
Severe contamination can lead to “contaminated land” [as defined under Part IIA of the Environmental
Protection Act (1990)]. This report does not consider the state and impacts of contaminated land on
the wider environment in detail. For further information on contaminated land, see ‘Dealing with Land
Contamination in Scotland’ (SEPA, 2009).
This chapter considers the causes of soil contamination and their environmental and socio-economic
impacts before going on to discuss the status of, and trends in, levels of contaminants in Scotland’s soils
Sources of semiochemicals mediating host finding in Callosobruchus chinensis (Coleoptera: Bruchidae)
Bruchid pests such as Callosobruchus chinensis (Linnaeus) endanger stored legume seeds throughout the tropical belt. The chemical composition of the headspace volatiles from healthy and fourth instar larvae-infested cowpea seeds were identified, characterized, and compared using gas chromatography-mass spectrometry. Y-tube olfactometer bioassays were performed to evaluate the effect of these chemicals on the orientation of conspecific adult females. Analysis of volatiles released from healthy and infested seeds revealed qualitative differences for three out of the 17 compounds identified. Dimethyl disulphide, isobutenyl methyl ketone and methyl trisulphide were found only in the blend emitted from infested but not from healthy seeds. Quantitative differences were apparent for tridecane which was released in larger amounts from infested seeds. While volatiles collected from healthy seeds were attractive to female bruchids, volatiles collected from infested seeds were repellent. To test the hypothesis that the qualitative differences in the chemical composition found may be due to insect-derived components, the volatiles from frass and fourth instar larvae combined were analysed. These volatiles contained both of the sulphides emitted from infested seed but not from healthy seeds. Although a limited induction of volatiles from cowpea seeds cannot be excluded, it is postulated that behavioural differences of the female weevils are largely due to insect-derived semiochemicals. The potential use of such semiochemicals as part of an integrated pest management strategy is discusse
Coordinate Singularities in Harmonically-sliced Cosmologies
Harmonic slicing has in recent years become a standard way of prescribing the
lapse function in numerical simulations of general relativity. However, as was
first noticed by Alcubierre (1997), numerical solutions generated using this
slicing condition can show pathological behaviour. In this paper, analytic and
numerical methods are used to examine harmonic slicings of Kasner and Gowdy
cosmological spacetimes. It is shown that in general the slicings are prevented
from covering the whole of the spacetimes by the appearance of coordinate
singularities. As well as limiting the maximum running times of numerical
simulations, the coordinate singularities can lead to features being produced
in numerically evolved solutions which must be distinguished from genuine
physical effects.Comment: 21 pages, REVTeX, 5 figure
A randomised trial evaluating Bevacizumab as adjuvant therapy following resection of AJCC stage IIB, IIC and III cutaneous melanoma : an update
At present, there are no standard therapies for the adjuvant treatment of malignant melanoma. Patients with primary tumours with a high-Breslow thickness (stages IIB and IIC) or with resected loco-regional nodal disease (stage III) are at high risk of developing metastasis and subsequent disease-related death. Given this, it is important that novel therapies are investigated in the adjuvant melanoma setting. Since angiogenesis is essential for primary tumour growth and the development of metastasis, anti-angiogenic agents are attractive potential therapeutic candidates for clinical trials in the adjuvant setting. Therefore, we initiated a phase II trial in resected high-risk cutaneous melanoma, assessing the efficacy of bevacizumab versus observation.
In the interim safety data analysis, we demonstrate that bevacizumab is a safe therapy in the adjuvant melanoma setting with no apparent increase in the surgical complication rate after either primary tumour resection and/or loco-regional lymphadenectomy
Relativistic effects in the processes of heavy quark fragmentation
In the framework based on the quasipotential method and relativistic quark
model a new covariant expression for the heavy quark fragmentation amplitude to
fragment into the pseudoscalar and vector S-wave heavy mesons is obtained. It
contains all possible relativistic corrections including the terms connected
with the transformation law of the bound state wave function to the reference
frame of the moving meson. Relativistic corrections of order {\bf p}^2/m^2 to
the heavy quark fragmentation distributions into (\bar c c), (\bar b c) and
(\bar b b) states are calculated as functions of the longitudinal momentum
fraction z and the transverse momentum p_T relative to the jet axis.Comment: 23 pages, 6 figure
New explicit spike solution -- non-local component of the generalized Mixmaster attractor
By applying a standard solution-generating transformation to an arbitrary
vacuum Bianchi type II solution, one generates a new solution with spikes
commonly observed in numerical simulations. It is conjectured that the spike
solution is part of the generalized Mixmaster attractor.Comment: Significantly revised. Colour figures simplified to accommodate
non-colour printin
El poder transformador del teatro en la expresi?n oral y corporal de los ni?os de grado primero del Colegio Americano de Pereira
229 p. Recurso Electr?nicoEl presente proyecto El poder transformador del teatro en la expresi?n oral y corporal de
los ni?os y ni?as del grado primero del colegio Americano de la ciudad de Pereira, toma
las artes como herramienta conductora y formadora, apoyando los diferentes procesos
acad?micos de la instituci?n en pro de una formaci?n integral en ellos y bas?ndose en
el teatro como eje articulador en la construcci?n de la personalidad, las cualidades y
aptitudes desde ?l mismo y hacia los dem?s.
El teatro es entonces el que permite influir en las diferentes expresiones del ni?o, por
medio de la implementaci?n de estrategias l?dicas a partir de la danza, la m?sica, la
poes?a, la literatura y las manualidades convirti?ndose estas en actividades integradoras
y fortalecedoras de las tem?ticas acad?micas y reflexivas de la instituci?n, innovando
permanentemente en la formaci?n integral de los estudiantes no solo del grado primero
sino tambi?n en estudiantes de otros grados, donde uno de los grandes prop?sitos es
fortalecer su desempe?o como ser social y lo haga participe activo de su propio
aprendizaje, a que disfrute de su ambiente escolar, a que se convierta en un ser cr?tico
activo y constructivo en el aula.
Palabras clave: herramienta, corporal, verbal, artes, formaci?n, teatro, estrategias,
danza, literatura, m?sica, articulador y construcci?n,This project called The power transformer theater in body and verbal expression of
children in the first grade of the College Americano in the city of Pereira, takes the arts
as conductive and forming tool, supporting different academic processes of the institution
pro a comprehensive education of them and based on the theater as the linchpin in
building the personality, qualities and skills from himself and toward others.
The theater is then, which allows to influence the different expressions of the child,
through the implementation of recreational activities from dance strategies, music, poetry,
literature and crafts becoming these in integrating and fortifying activities of the academic
and reflective thematic of the institution, constantly innovating in the integral formation of
students, not only the first grade but also students from other grades, where one of the
main purposes is to strengthen its performance as a social being and make him an active
participant in their own learning, to enjoy the school environment, to become an active
and constructive being in the classroom.
Key Words: tool, bodily, verbal, Arts, training, theater, strategies, dance, literature,
music, articulator and constructio
Response of female Cydia molesta (Lepidoptera: Tortricidae) to plant derived volatiles
Peach shoot volatiles were attractive to mated female oriental fruit moth, Cydia molesta (Busck), in a dual choice arena. No preference was observed between leaf odours from the principle host plant, peach, and the secondary host plant, apple. Twenty-two compounds were identified in headspace volatiles of peach shoots using gas chromatography-mass spectrometry. Green leaf volatiles accounted for more than 50% of the total emitted volatiles. A bioassay-assisted fractionation using different sorbent polymers indicated an attractant effect of compounds with a chain length of 6-8 carbon atoms. The major compounds of this fraction were tested either singly or in combinations for behavioural response of females. Significant bioactivity was found for a three-component mixture of (Z)-3-hexen-1-yl acetate, (Z)-3-hexen-1-ol and benzaldehyde in a 4:1:1 ratio. This synthetic mixture elicited a similar attractant effect as the full natural blend from peach shoots as well as the bioactive fractio
Manufacture of Gowdy spacetimes with spikes
In numerical studies of Gowdy spacetimes evidence has been found for the
development of localized features (spikes) involving large gradients near the
singularity. The rigorous mathematical results available up to now did not
cover this kind of situation. In this work we show the existence of large
classes of Gowdy spacetimes exhibiting features of the kind discovered
numerically. These spacetimes are constructed by applying certain
transformations to previously known spacetimes without spikes. It is possible
to control the behaviour of the Kretschmann scalar near the singularity in
detail. This curvature invariant is found to blow up in a way which is
non-uniform near the spike in some cases. When this happens it demonstrates
that the spike is a geometrically invariant feature and not an artefact of the
choice of variables used to parametrize the metric. We also identify another
class of spikes which are artefacts. The spikes produced by our method are
compared with the results of numerical and heuristic analyses of the same
situation.Comment: 25 page
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