Shrimps can be used as indicators of the quality of aquatic systems exposed to a variety of pollutants. Chlorpyrifos is one of the most common pesticides found in environmental samples. In order to ...evaluate the effects of chlorpyrifos, adult organisms of Litopenaeus vannamei were exposed to two sublethal concentrations of the pesticide (0.7 and 1.3 μg/L) for four days. The LC50 (96-hours) value was determined and Lipid oxidation levels (LPO) and the activities of catalase (CAT), glutathion peroxidase (GPx), glutathion-S-transferase (GST) were assessed on the muscle, hepatopancreas and gills from the exposed organisms. In addition, inhibition of acetylcholinesterase (AChE) was determined in the brain. LC50 (96-hours) was 2.10 μg/L of chlorpyrifos. Catalase activity and LPO were elevated in the three tissues, whereas a decrease of AChE activities in the brain and an increase of GST activity in the hepatopancreas were observed.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Computational Fluid Dynamics (CFD) was used to simulate the mixing characteristics of four different circular anaerobic digester tanks (diameters of 13.7, 21.3, 30.5, and 33.5
m) equipped with single ...and multiple draft impeller tube mixers. Rates of mixing of step and slug injection of tracers were calculated from which digester volume turnover time (DVTT), mixture diffusion time (MDT), and hydraulic retention time (HRT) could be calculated. Washout characteristics were compared to analytic formulae to estimate any presence of partial mixing, dead volume, short-circuiting, or piston flow. CFD satisfactorily predicted performance of both model and full-scale circular tank configurations.
This paper is devoted to the study of the existence of positive solutions for a problem related to a higher order fractional differential equation involving a nonlinear term depending on a fractional ...differential operator, (−Δ)αu=λu+(−Δ)β|u|p−1uinΩ,(−Δ)ju=0on∂Ω,forj∈Z,0≤j<α,where Ω is a bounded domain in RN, 0<β<1, β<α<β+1 and λ>0. In particular, we study the fractional elliptic problem, (−Δ)α−βu=λ(−Δ)−βu+|u|p−1uinΩ,u=0on∂Ω,and we prove existence or nonexistence of positive solutions depending on the parameter λ>0, up to the critical value of the exponent p, i.e., for 1<p≤2μ∗−1 where μ≔α−β and 2μ∗=2NN−2μ is the critical exponent of the Sobolev embedding.
Resumen Antecedentes: la aplicación de mallas con fijación al ligamento sacroespinoso para corregir el prolapso apical de órganos pélvicos tiene tasas de éxito objetivo de 92%, con 2-12% de eventos ...adversos. Objetivo: evaluar los resultados clínicos posteriores a la aplicación de la malla UpholdTM en pacientes con prolapso apical, con o sin útero. Materiales y métodos: estudio retrospectivo y descriptivo efectuado en pacientes atendidas en la Clínica de Urología Ginecológica del Instituto Nacionalo de Perinatología Isidro Espinosa de los Reyes entre los meses de noviembre de 2013 a marzo de 2017 con prolapso de órganos pélvicos de la cúpula a quienes se aplicaron mallas que se fijaron al ligamento sacroespinoso. A las pacientes con incontinencia urinaria de esfuerzo se les colocó una cinta mediouretral. Resultados: se estudiaron 22 pacientes de las que 72% (n = 16) tenían histerectomía previa. El estadio del prolapso de órganos pélvicos fue II en 18% (n = 4), III en 41% (n = 9) y IV en 41% (n = 9). El compartimento anterior se encontró afectado en 41% (n = 9) y en 59% (n = 13) el apical. El 54% (n = 12) de las pacientes tenía incontinencia urinaria de esfuerzo. A 9% (n = 2) de las pacientes solo se les colocó la malla UpholdTM, a 45% (n = 10) se les practicó una cirugía concomitante para corrección del prolapso de órganos pélvicos (colpoplastia posterior n = 5, colpoperineoplastia n = 4 y 1 culdoplastia) y para incontinencia urinaria de esfuerzo a 68% (n = 15) se les colocó una cinta mediouretral. El 9% (n = 2) tuvieron lesión vesical, 40% (n = 9) retención urinaria, 4.5% (n = 1) exposición y 4.5% (n = 1) extrusión. El éxito subjetivo y objetivo fue de 100%. Conclusiones: la colocación de la malla Uphold con fines de corrección del prolapso apical tiene buenos resultados, con mínimos efectos adversos. El procedimiento antiincontinencia concomitante incrementa la retención urinaria.
Night Sky Brightness at San Pedro Martir Observatory Plauchu-Frayn, I.; Richer, M. G.; Colorado, E. ...
Publications of the Astronomical Society of the Pacific,
03/2017, Letnik:
129, Številka:
973
Journal Article
Recenzirano
Odprti dostop
We present optical UBVRI zenith night sky brightness measurements collected on 18 nights during 2013 to 2016 and SQM measurements obtained daily over 20 months during 2014 to 2016 at the Observatorio ...Astronómico Nacional on the Sierra San Pedro Mártir (OAN-SPM) in México. The UBVRI data is based upon CCD images obtained with the 0.84 m and 2.12 m telescopes, while the SQM data is obtained with a high-sensitivity, low-cost photometer. The typical moonless night sky brightness at zenith averaged over the whole period is U = 22.68, B = 23.10, V = 21.84, R = 21.04, I = 19.36, and SQM = 21.88 mag arcsec − 2 , once corrected for zodiacal light. We find no seasonal variation of the night sky brightness measured with the SQM. The typical night sky brightness values found at OAN-SPM are similar to those reported for other astronomical dark sites at a similar phase of the solar cycle. We find a trend of decreasing night sky brightness with decreasing solar activity during period of the observations. This trend implies that the sky has become darker by Δ U = 0.7, Δ B = 0.5, Δ V = 0.3, Δ R = 0.5 mag arcsec−2 since early 2014 due to the present solar cycle.
This paper is devoted to study a class of systems of nonlinear Schrodinger equations: $$\left\{\begin{array}{rcl} -\Delta u+u-u^{3}=\epsilon v, \\ -\Delta v+v-v^{3}=\epsilon u, \end{array}\right.$$ ...in $$\mathbb{R}^{n}$$ with dimension n = 1,2,3. Our main result states that if $$\mathcal{P}$$ denotes a regular polytope centered at the origin of $$\mathbb{R}^{n}$$ such that its side is greater than the radius, then there exists a solution with one multi-bump component having bumps located near the vertices of $$\xi\mathcal{P}$$, where $${\xi\sim \log(1/\varepsilon)}$$, while the other component has one negative peak. PUBLICATION ABSTRACT
The chemical composition of essential oils isolated from aerial parts of Triphasia trifolia (Burm. f.) P. Wilson was analyzed using hydrodistillation by GC–MS. The main constituents found were ...β-pinene (64.36%), (+)-sabinene (8.75%), hexadecanoic acid (6.03%), α-limonene (4.24%) and p-cymene (2.73%). The essential oil from T. trifolia shows high antioxidant potential (94.53%), an effect that is comparable with ascorbic acid (96.40%), used as standard. In addition, these oils had high repellent effects on the insect Tribolium castaneum Herbst (99% ± 1) at 0.2 μL/cm2 after 2 h of exposure.
Se realizó un estudio de los residuos de pesticidas organofosforados presentes en frutas de alto consumo en la zona tropical de Colombia, exactamente en la ciudad de Cartagena de indias, cuyas frutas ...provienen de distintos puntos de venta. las cuales fueron mango, guayaba y papaya, se cualificaron mediante cromatografía de gases acoplada a masas donde se confirmó la presencia de pesticidas organofosforados, encontrando: Clorpirifós, Disulfoton, Forato, Anzinfosmetil, Malation, Fenclorfos y Dementon--s-metilsulfon. Utilizando el método mencionado anteriormente se cuantificaron algunos de los pesticidas los cuales fueron: Disulfoton el cual arrojo para muestras de centros comerciales un intervalo de concentración de 0.19 ppm-5.19 ppm, para las de plazas de mercado 0.35ppm-6.27ppm, Clorpirifós se detectó solo en una muestra a 21.5 ppm y Anzinfosmetil se encuentra de 0.5 ppm-16.4 ppm para las muestras de centro comercial y para las de plaza de mercado 1.26 ppm-18.8 ppm. Palabras clave: frutas tropicales, organofosforado, cromatografía. A study of residues of organ phosphorus pesticides in high consumption fruits took place in the tropical zone of Colombia, exactly in the city of Cartagena de Indias, whose fruits come from different outlets. The fruits were mango, guava and papaya and they were qualified by gas chromatography coupled to mass where the presence of organophosphate pesticides was confirmed by finding chlorpyrifos, disulfoton, phorate, Anzinfosmetil, Malathion, and Dementon Fenchlorphos-s-metilsulfon. Using the above mentioned method some of the pesticides were quantified. They were: Disulfoton which had, for samples from malls, a concentration range of 0.19 ppm-5.19 ppm, for marketplaces of 6.27ppm-0.35ppm, Chlorpyrifos which was detected only in one sample to 21.5 ppm and Anzinfosmetil that was of 0.5 ppm-16.4 ppm for samples from mall and of 1.26 ppm-18.8 ppm in the ones from marketplace. Keywords: tropical fruits, organophosphate, chromatography.
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•Volatile composition of P. dilatatum, P. divaricatum, P. hispidum and P. sanctifelicis essential oils was studied.•Strong antifeedant effects were observed for all oils, being Piper ...dilatatum the most effective.•These essential oils showed strong herbicidal potential on Lolium perenne and Lactuca sativa.
The insect antifeedant and phytotoxic effects of the essential oils (EO) from four populations of Piper species (Piper dilatatum, Piper divaricatum, Piper aff. hispidum and Piper sanctifelicis) have been studied against pests of economic importance in agriculture (Spodoptera littoralis, Myzus persicae, and Rhopalosiphum padi) and mono and dicotyledoneous plant models (Lolium perenne and Lactuca sativa). The main components found in the essential oils (EOs) were eugenol (37.5%), methyl eugenol (36.3%), γ-elemene (10.7%) (P. divaricatum); apiol (79.0%), trans-caryophyllene (8.3%) (P. dilatatum); δ-3-carene (35.3%), limonene (27.1%), p-cymene (4.9%), β-pinene (6.9%) and nerolidol (5.8%) (P. sanctifelicis); limonene (17.2%), δ-3-carene (9.6%), p-cymene (10.9%), elemol (14.1%), and Spathulenol (6.1%) (P. aff. hispidum). Strong antifeedant and phytotoxic effects were observed for all these oils. P. dilatatum EO was the most effective antifeedant. P. dilatatum and P. divaricatum EOs showed strong herbicidal potential on L. perenne and P. aff hispidum reduced the root growth of L. sativa.
We obtain existence and multiplicity results for the solutions of a class of coupled semilinear bi-harmonic Schrödinger equations. Actually, using the classical Mountain Pass Theorem and minimization ...techniques, we prove the existence of critical points of the associated functional constrained on the Nehari manifold.
Furthermore, we show that using the so-called fibering method and the Lusternik–Schnirel’man theory there exist infinitely many solutions, actually a countable family of critical points, for such a semilinear bi-harmonic Schrödinger system under study in this work.
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