183 research outputs found
Spontaneous concentrations of solids through two-way drag forces between gas and sedimenting particles
No full textThe behaviour of sedimenting particles depends on the dust-to-gas ratio of the fluid. Linear stability analysis shows that solids settling in the Epstein drag regime would remain homogeneously distributed in non-rotating incompressible fluids, even when dust-to-gas ratios reach unity. However, the nonlinear evolution has not been probed before. Here, we present numerical calculations indicating that, in a particle-dense mixture, solids spontaneously mix out of the fluid and form swarms that are overdense in particles by at least a factor 10. The instability is caused by mass-loaded regions locally breaking the equilibrium background stratification. The driving mechanism depends on nonlinear perturbations of the background flow and shares some similarity to the streaming instability in accretion discs. The resulting particle-rich swarms may stimulate particle growth by coagulation. In the context of protoplanetary discs, the instability could be relevant for aiding small particles to settle to the midplane in the outer disc. Inside the gas envelopes of protoplanets, enhanced settling may lead to a reduced dust opacity, which facilitates the contraction of the envelope. We show that the relevant physical set up can be recreated in a laboratory setting. This will allow our numerical calculations to be investigated experimentally in the future
Negative polarization properties of regolith simulants
No full textContext. Polarization phase curves of asteroids and other small airless bodies are influenced by the compositional and physical properties of their regolith. The mixing of minerals composing the regolith influences the negative polarization at small phase angles because it changes the multiple scattering properties of the medium.
Aims. This work aims to demonstrate experimentally how the mixing effect influences the polarization phase curve at small phase angles for different mineralogies relevant for asteroids, and to determine how different aggregate sizes affect the negative polarization.
Methods. We prepared a set of binary and ternary mixtures with different common minerals on asteroids and one set of the same mixture with different aggregate sizes. We measured their reflected light at 530 nm with full Stokes polarimetry at phase angles ranging from 0.8° to 30°.
Results. The mixing effect of the mixtures with both bright and dark minerals significantly changes the behavior of the phase curves in terms of minimum polarization, phase angle of the minimum, and inversion angle with respect to the mineral components that are mixed together. The changes in phase curve could explain the polarization observation of particular classes of asteroids (F and L class) and other asteroids with peculiar polarization curves or photometric properties. Furthermore, we demonstrate that the negative polarization is invariant to the presence of dust aggregates up to centimeter sizes
Efecto de extractos de Schinus molle (L.) y Artemisia absinthium (L.), solos y en mezcla con Bacillus thuringiensis (Berliner), sobre Heliothis zea (Boddie)
No full textTesis presentada como parte de los requisitos para optar al Grado de Magíster en Ciencias
Agropecuarias, Mención Sanidad VegetalEn un ensayo de laboratorio se determinó el efecto antialimentario de extractos acuosos de
hojas de Schinus molle (L.) y Artemisia absinthium (L.) al 100 y 50% v/v de las
concentraciones máximas obtenidas, sobre larvas de tercer estadío de Heliothis zea
(Boddie), una plaga importante en maíz para consumo fresco en muchos países. También se
evaluó en laboratorio el efecto tóxico de ambos extractos al 100 y 50% v/v, solos y en
mezcla con Bacillus thuringiensis Berliner var. kurstaki (Btk) al 50% sobre las larvas.
Finalmente, las concentraciones de ambos extractos se aplicaron sobre estilos frescos en un
ensayo de campo, donde se evaluó el número de larvas de H. zea y el daño causado en
mazorcas frescas a la cosecha en el Cantón Chambo, Provincia de Chimborazo, Ecuador.
En los ensayos de laboratorio para los efectos antialimentario e insecticida se usó un diseño
aleatorizado, y en el de campo uno en bloques completamente aleatorizado; en este ensayo,
además de los tratamientos indicados arriba se usó un testigo sin tratar y un tratamiento
estándar (en Ecuador) con el insecticida comercial Nockeo® (tiametoxan +
lambdacialotrina). El extracto acuoso de S. molle al 100 y 50% v/v tuvo efecto
antialimentario de 45,2 y 48%, respectivamente y el de A. absinthium al 100 y 50% v/v
ningún efecto (0%). En el ensayo del efecto insecticida en laboratorio, los extractos de S.
molle al 100 y 50% v/v y S. molle en mezcla con Btk al 50% causaron mortalidad de 20, 28
y 44%, respectivamente, al igual que A. absinthium al 100 y 50% v/v y A. absinthium 100%
v/v en mezcla con Btk al 50% (24, 40 y 28% de mortalidad, respectivamente) a 15 dda. Los
extractos acuosos de hojas de S. molle y A. absinthium solos y en mezcla con Btk no
disminuyeron significativamente el daño causado por las larvas de H. zea, pero los
extractos de S. molle 100% v/v, S. molle 100% v/v en mezcla con Btk 50% y Btk 100% v/v
redujeron significativamente el número promedio de larvas detectadas a la cosecha en 20
mazorcas frescas en el campo, 3,4; 4,8 y 4,4, respectivamente. Estos resultados motivan,
previo a pruebas del efecto residual y fotodegradación, y mejoras en técnicas de aplicación
en el campo, a continuar con la evaluación de extractos botánicos en mezcla con Btk con el
fin de reducir el uso indiscriminado de insecticidas convencionales.The antifeeding effect of water extracts from Schinus molle (L.) y Artemisia absinthium
(L.) were determined in the laboratory at 100 and 50% of the maximum concentrations
obtained, on third stage Heliothis zea (Boddie) larvae, an important pest of fresh corn in
many countries. The toxic effect on those larvae of both extracts at 100 and 50%, alone and
mixed with Bacillus thuringiensis Berliner var. kurstaki (Btk) at 50% were also determined.
Finally, the concentrations of both extracts were applied to the fresh ear corn styles in a
field trial in Cantón Chambo, Provincia de Chimborazo, Ecuador, were the number of H.
zea larvae and the damage caused on fresh corn ears were determined at harvest. In the
laboratory test for the antifeeding and insecticide effects a random design was used, and a
completely random block design was used in the field trial, were besides the treatments
indicated above, an untreated control and a standard treatment (in Ecuador) with the
commercial insecticide Nockeo® (tiametoxan + lambdacyalotrin). The S. molle water
extract at 100 and 50% v/v had 45.2 and 48% antifeeding effect, respectively, and that from
A. absinthium at 100 and 50% v/v had no effect (0%). In the insecticide test in the
laboratory, 15 days after application, the water S. molle extracts at 100 and 50% v/v, and S.
molle mixed with Btk at 50% caused 20, 28, and 44% mortality, respectively, similarly to A.
absinthium at 100 and 50% v/v, and A. absinthium 100% v/v mixed with Btk at 50% (24,
40, and 28% mortality, respectively). The water extracts from S. molle and A. absinthium,
singly or mixed with Btk did not decrease significantly the damage caused by H. zea larvae,
but the S. molle extract at 100% v/v, and at 100% v/v mixed with Btk at 50% or 100% v/v
reduced significantly the average number of larvae detected at harvest on 20 fresh corn ears
in the field, 3.4, 4.8, and 4.4, respectively. These results prompt, after tests of residual
effect and light degradation, and improvements in the application techniques in the field, to
continue evaluating plant extracts mixed with Btk with the goal of reducing the
indiscriminate use of conventional insecticides
Normalization methods in mass spectrometry-based analytical proteomics: A case study based on renal cell carcinoma datasets
No full textNormalization is a crucial step in proteomics data analysis as it enables data adjustment and enhances comparability between datasets by minimizing multiple sources of variability, such as sampling, sample handling, storage, treatment, and mass spectrometry measurements. In this study, we investigated different normalization methods, including Z-score normalization, median divide normalization, and quantile normalization, to evaluate their performance using a case study based on renal cell carcinoma datasets. Our results demonstrate that when comparing datasets by pairs, both the Z-score and quantile normalization methods consistently provide better results in terms of the number of proteins identified and quantified as well as in identifying statistically significant up or down-regulated proteins. However, when three or more datasets are compared at the same time the differences are found to be negligible
Concentrations and correlations of disinfection by-products in municipal drinking water from an exposure assessment perspective (Erratum to: vol 114, pg 1, 2012)
No full textThe authors have discovered an inadvertent omission of a funding source, that should have been included: FIS PI09/00773.Villanueva, C.M., Castaño-Vinyals, G., Moreno, V., Carrasco-Turigas, G., Aragonés, N., Boldo, E., Ardanaz, E., Toledo, E., Altzibar, J.M., Zaldua, I., Azpiroz, L., Goñi, F., Tardón, A., Molina, A.J., Martín, V., López-Rojo, C., Jiménez-Moleón, J.J., Capelo, R., Gómez-Acebo, I., Peiró, R., Ripoll, M., Gracia-Lavedan, E., Nieuwenhujsen, M.J., Rantakokko, P., Goslan, E.H., Pollán, M., Kogevinas, M
Expositio magni prophete Abbatis Ioachim in Apocalipsim : opus illud celebre, aurea, v[erum], ac preceteris longe altior [et] profundior explanatio in Apocalipsim Abbatis Joachim de statu uniuersali reipublic[a]e christian[a]e, deq[ue] ecclesia carnali in proximo reformanda ... ; cui adiecta sunt eiusde[m] psalteriu[m] dece[m] corda[rum] opus [pro]pe diuinu[m]. Lectura ite[m] p[er] lucida in Apocalipsis Reruere[n]di magistri Philippi de Mantua Augustiniane ... famili[a]e ...
No full textDatos de publicación tomados del colofón en v. de h. DD4Sign.: A4, A-Z8, AA-NN8, OO4, aa-cc8Texto a dos col. con apost. y recl., L. gót., port. con orla xil. a dos tintas y con esc. xil. con capelo cardenalicio e iniciales F.E.Ex-libris ms. en port .del colegio de San Ambrosio de Valladolid, de su bibliotecaGuillotinado en un cambio de encuadernaciónEnc. en pasta española. Lomo con cuatro nervios perfilados, entrenervios decorados con adornos florales doradosAnt. sign.: 00491 en etiqueta impresa de la Biblioteca universitaria en contraguarda anterio
<em>N</em><sup>1</sup>-((1<em>H</em>-Indazol-5-yl)methylene)-<em>N</em><sup>2</sup>-(2-((2-((2-(((1<em>H</em>-indazol-6-yl)methylene)amino)ethyl)amino)ethyl)amino)ethyl)ethane-1,2-diamine
No full textOne novel molecular emissive probe <strong>L</strong> has been synthesized by classical Schiff-base reaction between 1H-indazole-6-carboxaldehyde<strong> </strong>and tetraethylenepentamine. The structure of compound <strong>L</strong> was confirmed by melting point, elemental analysis, ESI-MS spectrometry and by IR and <sup>13</sup>C-NMR and <sup>1</sup>H-NMR spectroscopy
Efecto del Resveratrol y L-carnitina suplementado al medio de maduración sobre la producción in vitro de embriones bovinos
No full textEl resveratrol (RES) y la L-carnitina (LC) son dos aditivos/antioxidantes eficaces para reducir
estrés oxidativo y estimular el metabolismo energético de las células. En este sentido, esta
investigación evaluó el efecto de la suplementación con LC (0,3 mg/ml), RES (1 μM) y su
combinación (RES+LC= 0,5 μM + 0,15 mg/ml) al medio MIV de ovocitos sobre la tasa de
maduración nuclear (M II) y la tasa de desarrollo embrionario (clivaje y blastocistos) posterior
a la fertilización in vitro (FIV). Un total de 1209 ovocitos fueron recuperados de ovarios
bovinos, y madurados in vitro en medio MIV suplementado con LC (n = 304), RES (n = 300),
LC+RES (n = 302) y control (n = 303). Después de 24 h de incubación, un lote de 100 ovocitos
de cada grupo fueron evaluados la maduración nuclear (MII), y el resto fueron fertilizados y
cultivados in vitro durante 7 días. Los resultados demostraron que no hubo diferencias
significativas en la tasa de MII (P>0,05). La tasa de clivaje fue mayor (P<0,05) en los ovocitos
madurados con LC comparados con el control. La tasa de blastocistos fue significativamente
mayor (P<0,05) en los ovocitos madurados con LC que aquellos madurados con LC+RES y
control (39,7 ± 3,43% vs. 27,2 ± 3,14% y 30,0 ± 3,23%, respectivamente). En conclusión, la
L-carnitina suplementada al medio de maduración de ovocitos bovinos produjo un mejor
desarrollo embrionario, mientras que el resveratrol, solo o combinado con L-carnitina, no tuvo
un efecto significativo en la producción in vitro de embriones bovinosResveratrol (RES) and L-carnitine (LC) are two effective additives/antioxidants for reducing
oxidative stress and stimulating cellular energy metabolism. Accordingly, this research
evaluated the effect of supplementing with LC (0.3 mg/ml), RES (1 μM), and their combination
(RES+LC= 0.5 μM + 0.15 mg/ml) to the MIV medium of oocytes on the rate of nuclear
maturation (MII) and the rate of embryonic development (cleavage and blastocysts) following
in vitro fertilization (IVF). A total of 1209 oocytes were recovered from bovine ovaries and
matured in vitro in MIV medium supplemented with LC (n = 304), RES (n = 300), LC+RES (n
= 302), and control (n = 303). After 24 hours of incubation, a batch of 100 oocytes from each
group was assessed for nuclear maturation (MII), and the remainder were fertilized and
cultured in vitro for 7 days. The results demonstrated no significant differences in the MII rate
(P>0.05). The cleavage rate was higher (P<0.05) in oocytes matured with LC compared to the
control. The blastocyst rate was significantly higher (P<0.05) in oocytes matured with LC than
those matured with LC+RES and control (39.7 ± 3.43% vs. 27.2 ± 3.14% and 30.0 ± 3.23%,
respectively). In conclusion, L-carnitine supplementation to the maturation medium of bovine
oocytes resulted in improved embryonic development, whereas resveratrol, either alone or
combined with L-carnitine, had no significant effect on the in vitro production of bovine
embryos0000-0002-0266-543
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