1,438 research outputs found
Decay study of pesticide residues in apple samples
A method for monitoring pesticides in apple samples, including Soxhlet extraction, an evaporation step and capillary gas chromatography with nitrogen-phosphorus detection, is applied to a decay study of the carbamate pesticide ethiofencarb. The evaporation step is carried out by a surface nitrogen flow and the recoveries of ethiofencarb measured in standard solutions of ethyl acetate and apple extracts. The results of the decay studies show that ethiofencarb is degraded in the apple peel faster than in the interior of the fruit. The methodology is then applied to decay studies in the laboratory of the organophosphorus pesticides, diclofluanid, fenitrothion and malathion
Synchrotron emitting Komissarov torus around naked singularities
From a theoretical perspective, matter accretion processes around compact
objects are highly relevant as they serve as a natural laboratory to test
general relativity in the strong field regime. This enables us to validate
fundamental concepts such as the no-hair theorem, the cosmic censorship
hypothesis, and the existence of alternative solutions to Einstein's equations
that mimic the effects of black holes. In this study, we analyze the emission
spectra of geometrically thick accretion disks, referred to as Polish
doughnuts, around naked singularities described by the -metric. To begin, we
revisit the construction of equilibrium configurations of magnetized tori in
this spacetime and evaluate the role of the deformation parameter over these
configurations. Once we have systematically studied the disks in this
spacetime, we use the \texttt{OSIRIS} code to perform a backward ray-tracing
method, resulting in the first simulations of the intensity map and emission
profiles of magnetized tori within this metric. Furthermore, we validate the
effect of both the quadrupole moment and the angular momentum on observable
quantities such as flux and intensity for optically thin and thick disks, since
for values of , which correspond to objects with prolate deformation,
and which in turn, are constructed with higher values of angular momentum, the
emission spectrum exhibits higher intensity than that obtained for
Schwarzschild's spacetime. Hence, we find a first differential feature that
distinguishes tori formed around naked singularities from those around static
black holes.Comment: 27 pages, 9 figures. Accepted for publication in Classical and
Quantum Gravit
Phosphomannosylation and the functional analysis of the extended Candida albicans MNN4-like gene family
We thank Luz A. López-Ramírez (Universidad de Guanajuato) for technical assistance. This work was supported by Consejo Nacional de Ciencia y Tecnología (ref. CB2011/166860; PDCPN2014-247109, and FC 2015-02-834), Universidad de Guanajuato (ref. 000025/11; 0087/13; ref. 1025/2016; Convocatoria Institucional para Fortalecer la Excelencia Académica 2015; CIFOREA 89/2016), Programa de Mejoramiento de Profesorado (ref. UGTO-PTC-261), and Red Temática Glicociencia en Salud (CONACYT-México). NG acknowledges the Wellcome Trust (086827, 075470, 101873, and 200208) and MRC Centre for Medical Mycology for funding (N006364/1). KJ was supported by a research visitor grant to Aberdeen from China Scholarship Council (CSC No. 201406055024). The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2017.02156/full#supplementary-materialPeer reviewedPublisher PD
Contribución al conocimiento del género Anthyllis L. (Fabaceae) en la Peninsula Ibérica. A. plumosa sp. nov.
In this paper a morphological, palynologicaland caryologicalstudy of three species of Anthyllis (sect. Oreanthyllis)is included. As a consecuencea newspecies A.plumosa E. Domínguez from the dolomitics sands of Sierra de Almijara (Málaga) is described.Se realiza un estudio morfológico, palinológico y cariológico de tres especies del género Anthyllis (sect. Oreanthyllis), describiéndose una nueva especie, A. plumosa E. Domínguez procedente de las arenas dolomíticas de la Sierra de Almijara (Málaga)
Constraining the X-ray reflection in low accretion rate AGN using XMM-Newton, NuSTAR and Swift
An interesting feature in active galactic nuclei (AGN) accreting at low rate
is the weakness of the reflection features in their X-ray spectra, which can
result from the gradual disappearance of the torus with decreasing accretion
rates. It has been suggested that low luminosity AGN (LLAGN) would have a
different reflector configuration compared with high luminosity AGN, either
covering a smaller fraction of the sky or simply having less material.
Additionally, we note that the determination of the spectral index ()
and the cut-off energy of the primary power-law emission is affected by the
inclusion of reflection models, showing the importance of using them to study
the accretion mechanism, especially in the case of the LLAGN that have
previously shown a high dispersion on the relation between and the
accretion rate. Our purpose is to constrain the geometry and column density of
the reflector in a sample of LLAGN covering a broad X-ray range of energy
combining data from XMM-Newton + NuSTAR + Swift of a hard X-ray-flux limited
sample of 17 LLAGN from BASS/DR2 with accretion rates =L/L<10. We fit all spectra using the reflection model
for torus (borus02) and accretion disk (Xillver) reflectors. We found a
tentative correlation between the torus column density and the accretion rate,
LLAGN shows a lower column density compared with the high-luminosity objects.
We also confirm the relation between and , with a
smaller scatter than previously reported, thanks to the inclusion of
high-energy data and the reflection models. Our results are consistent with a
break at , suggestive of a different accretion
mechanism compared with higher accretion AGN.Comment: Accepted for publication in Astronomy & Astrophysic
Proteínas morfogenéticas óseas (BMPs): Efecto de la proteína osteogénica-1 (OP-l/BMP-7) en la condrogénesis y osteogenesis
En la actualidad, los estudios sobre biología molecular han facilitado el análisis de
ciertos factores de transformación del crecimiento tipo ß(TGF-ß)I, entre los que destaca una familia
de proteínas morfogenéticas óseas (BMPs). Las técnicas de ingeniería genética han permitido
replicar alguno de estos factores y localizar los genes que codifican dichas proteínas. La proteína
osteogenics-1 (OP-1) ha sido caracterizada y sintetizada in vitro y muestra un elevado potencial
osteogénico y condrogénico tanto in vivo como in vitro. Se presenta una revisión de los
últimos avances en la aplicación experimental de las BMPs, y especialmente de la OP-1, en el área
de la Cirugía Ortopédica y la TraumatologíaNowadays, molecular biology studies have promoted the bone morphogenetic
proteins (BMPs) analysis. These multifunctional proteins are structurally related to transforming
growth factor-6 (TGF-6). Genetic engineering techniques have allowed to sequence some of these
BMPs. It has been characterized the expression and processing of osteogenic protein-1 (OP-1),
a bone morphogenetic protein of the TGF-6 family. The OP-1 shows a high osteogenic and chondrogenic
potential. The aim of this paper is to review some updated advances of the BMPs experimental
applications, particularly OP-1, in relation to Orthopaedic Surgery and Traumatolog
A Bacia do Algarve: estratigrafia, paleogeografia e tectónica
A “Bacia do Algarve” corresponde, segundo a literatura científica tradicional, aos terrenos mesocenozóicos que orlam o Sul de Portugal, desde o Cabo de São Vicente ao rio Guadiana (~140km), penetrando irregularmente para o interior entre 3 km a 25 km, sobre terrenos de idade carbónica da Zona Sul Portuguesa. O hiato, de aproximadamente 70 milhões de anos, materializado pela discordância angular entre as rochas sedimentares de tipo flysch do Carbónico, metamorfizadas e deformadas durante a orogenia varisca, e as rochas sedimentares continentais do Triásico inferior provável, separa dois ciclos de Wilson. Os sedimentos carbónicos metamorfizados resultam do empilhamento orogénico de um possível prisma de acrecção associado à orogenia varisca e ao fecho de um oceano paleozóico e formação da Pangeia, enquanto que os sedimentos continentais triásicos resultam do fim do colapso e do arrasamento do orógeno varisco e início do estiramento continental que viriam a culminar com a separação das placas litosféricas África, Eurásia e América.Os sedimentos mais recentes do Mesozóico e os mais antigos bem datados do Cenozóico encontram-se separados por um outro hiato que ultrapassa ligeiramente os 70 milhões de anos na área emersa. Este hiato resulta duma alteração tectónica radical no contexto onde nessa época geológica se inseria a Bacia do Algarve. Esta mudança, que ocorreu no fim do Cenomaniano, resultou da rotação do vector de deslocamento da trajectória de África em relação à Eurásia, de aproximadamente NW-SE para SW-NE (segundo as coordenadas actuais, e.g. Dewey et al, 1989), poria termo ao regime distensivo e de bacia de tipo rifte na Bacia do Algarve, com o fim do regime transtensivo entre a região noroeste da placa África e sudoeste da placa Eurásia e início da colisão
Agroecosystem assessment for Latin America: agriculture extent, production systems and agrobiodiversity
- …