14,391 research outputs found
Bioremediation and biovalorisation of olive-mill wastes
Olive-mill wastes are produced by the industry of olive oil production, which is a very important economic activity, particularly for Spain, Italy and Greece, leading to a large environmental problem of current concern in the Mediterranean basin. There is as yet no accepted treatment method for all the wastes generated during olive oil production, mainly due to technical and economical limitations but also the scattered nature of olive mills across the Mediterranean basin. The production of virgin olive oil is expanding worldwide, which will lead to even larger amounts of olive-mill waste, unless new treatment and valorisation technologies are devised. These are encouraged by the trend of current environmental policies, which favour protocols that include valorisation of the waste. This makes biological treatments of particular interest. Thus, research into different biodegradation options for olive-mill wastes and the development of new bioremediation technologies and/or strategies, as well as the valorisation of microbial biotechnology, are all currently needed. This review, whilst presenting a general overview, focus critically on the most significant recent advances in the various types of biological treatments, the bioremediation technology most commonly applied and the valorisation options, which together will form the pillar for future developments within this fiel
Is emamectin benzoate effective against the different stages of Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae)?
peer-reviewedThis work was partially supported by the Spanish Ministry of Science and Innovation (project AGL 2007-66130-C03-02 to P. Medina). F. Amor and P. Bengochea acknowledge the ministry of Education
and Culture and the Technical University of Madrid (UPM) for the doctoral fellowships. Special thanks to Syngenta Agro S.A. for their support.The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae), is a major
polyphagous pest in greenhouses and open fields worldwide and also a main problem
in sweet pepper greenhouses. The effectiveness of the pesticide emamectin benzoate was tested in the laboratory on different stages of S. exigua using different concentrations and uptake routes. After dipping young (48-h-old) S. exigua eggs in emamectin benzoate at 0.5, 1 and 1.5 mg/L a.i. the chemical did not exhibit any ovicidal activity. There was, however, progressive neonate mortality at all concentrations,
culminating at 72 hours after hatching, when 100% of the larvae from the treated young
eggs died. Second and fourth instar S. exigua larvae did not exhibit significant mortality when exposed to the inert surfaces which were treated. In contrast, ingesting a diet contaminated with 0.5 mg/L a.i. of emamectin benzoate caused 100% mortality in L2 and L4 larvae 24 and 72 hours after ingestion, respectively. The LC50 value of the compound against L4 larvae that fed on sprayed sweet pepper leaves for 24 hours was 0.81 mg/L a.i..
When adults were fed on a solution of 0.5 mg/L a.i., there was a reduction in the female and male lifespan of 29.3% and 55.3%, respectively. Fecundity was reduced by more than 99%. These data suggest that emamectin benzoate is not only a useful insecticide when ingested by beet armyworm larvae but it also has ovolarvicidal and adult activity.Spanish Ministry of Science and Innovatio
Bayesian Inversion of Stokes Profiles
[abridged] Inversion techniques are the most powerful methods to obtain
information about the thermodynamical and magnetic properties of solar and
stellar atmospheres. In the last years, we have witnessed the development of
highly sophisticated inversion codes that are now widely applied to
spectro-polarimetric observations. The majority of these inversion codes are
based on the optimization of a complicated non-linear merit function. However,
no reliable and statistically well-defined confidence intervals can be obtained
for the parameters inferred from the inversions. A correct estimation of the
confidence intervals for all the parameters that describe the model is
mandatory. Additionally, it is fundamental to apply efficient techniques to
assess the ability of models to reproduce the observations and to what extent
the models have to be refined or can be simplified. Bayesian techniques are
applied to analyze the performance of the model to fit a given observed Stokes
vector. The posterior distribution, is efficiently sampled using a Markov Chain
Monte Carlo method. For simplicity, we focus on the Milne-Eddington approximate
solution of the radiative transfer equation and we only take into account the
generation of polarization through the Zeeman effect. However, the method is
extremely general and other more complex forward models can be applied. We
illustrate the ability of the method with the aid of academic and realistic
examples. We show that the information provided by the posterior distribution
turns out to be fundamental to understand and determine the amount of
information available in the Stokes profiles in these particular cases.Comment: 15 pages, 12 figures, accepted for publication in A&
Aplicação dos Isótopos Radioactivos 210Pb e 137Cs na Avaliação de Taxas de Sedimentação em Planícies aluviais: o caso da Lezíria do Tejo
Este artigo visa divulgar os primeiros resultados obtidos na definição das taxas de sedimentação, no último século, numa área-amostra da planície aluvial do Tejo, com o recurso a métodos de datação radiométricos adequados a esta escala temporal (210Pb e 137Cs).
O estudo baseou-se na sondagem SEV, efectuada numa área deprimida da planície aluvial, a 2,5km da margem direita do rio, a norte de Santarém, no âmbito do projecto GEOTARIF (Geology and Archaeology of the Tagus River Floodplain over Time, POCTI/CTA/39427/2001). Foram seleccionados apenas os 1,09m superficiais da sondagem, os quais foram seccionados em amostras de 1cm de espessura. A metodologia seguida para o tratamento das 109 amostras e para a análise do 210Pb seguiu o método de Sanchez-Cabeza et al (1998) e a cronologia da sedimentação foi obtida através do modelo CRS (Appleby & Oldfield, 1978; Sanchez-Cabeza et al, 2000).
A taxa de sedimentação média para o século XX, obtida a partir do 210Pb (em excesso), foi de 8,8mm/ano, mas os dois aspectos essenciais são: (i) a grande variação na deposição de sedimentos ao longo do último século; (ii) a clara tendência do aumento das taxas de sedimentação, nesta área da planície aluvial, em especial a partir dos anos 60.
Os dados obtidos para a deposição do 137Cs na planície aluvial do Tejo, entre 1954 e 1988, mostram uma maior contaminação dos sedimentos aluviais por este radionuclídeo, a partir da entrada em funcionamento da Central nuclear de Almaraz.info:eu-repo/semantics/publishedVersio
Spectral distortions from promising single and multifield inflationary models
Forthcoming missions probing the absolute intensity of the CMB are expected
to be able to measure spectral distortions, which are deviations from its
blackbody distribution. As cosmic inflation can induce spectral distortions,
these experiments offer a possibility to further test the various promising
inflationary proposals, whose predictions need to be carefully determined.
After numerically fitting all inflationary observables to match current
observations, we compute the predicted spectral distortions of various
promising single and multifield inflationary models. The predictions of
single-field inflationary models display deviations between 1% and 20% with
respect to the standard cosmological model in the observable window, where
multi-natural and axion-monodromy inflation stand out in this respect. In the
case of multifield inflation, we observe a richer structure of the power
spectrum, which, in the case of so-called hybrid attractors, yields spectral
distortions about 100 times more intense than the standard signal. These
observations open up questions about the relation among our results and other
cosmological observables that are also to be probed soon.Comment: 30 pages + references, 17 figures, 6 table
G-band Spectral Synthesis in Solar Magnetic Concentrations
Narrow band imaging in the G-band is commonly used to trace the small
magnetic field concentrations of the Sun, although the mechanism that makes
them bright has remained unclear. We carry out LTE syntheses of the G-band in
an assorted set of semi-empirical model magnetic concentrations. The syntheses
include all CH lines as well as the main atomic lines within the band-pass. The
model atmospheres produce bright G-band spectra having many properties in
common with the observed G-band bright points. In particular, the contrast
referred to the quiet Sun is about twice the contrast in continuum wavelengths.
The agreement with observations does not depend on the specificities of the
model atmosphere, rather it holds from single fluxtubes to MIcro-Structured
Magnetic Atmospheres. However, the agreement requires that the real G-band
bright points are not spatially resolved, even in the best observations. Since
the predicted G-band intensities exceed by far the observed values, we foresee
a notable increase of contrast of the G-band images upon improvement of the
angular resolution. According to the LTE modeling, the G-band spectrum emerges
from the deep photosphere that produces the continuum. Our syntheses also
predict solar magnetic concentrations showing up in continuum images but not in
the G-band . Finally, we have examined the importance of the CH
photo-dissociation in setting the amount of G-band absorption. It turns out to
play a minor role.Comment: To appear in ApJ, 554 n2 Jun 20, 33 pages and 9 figure
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