462 research outputs found

    Photon Redshift in a Magnetic field

    Full text link
    Previous results from the authors concerning the arising a tiny photon anomalous paramagnetic moment are also interpreted as a red-shift in analogy to the gravitational known effect. It is due to the photon interaction with the magnetized virtual electron-positron background which withdraw transverse momentum from photons and is polarization-dependent. If the photon frequency red-shift implies a change in time, a clock would go faster for increasing magnetic field intensity

    Ultrasonic-assisted extraction and natural deep eutectic solvents combination: A green strategy to improve the recovery of phenolic compounds from Lavandula Pedunculata subsp. Lusitanica (Chaytor) Franco

    Get PDF
    The present study aimed at evaluating the effectiveness of different natural deep eutectic solvents (NADES) on the extraction of phenolic compounds from Lavandula pedunculata subsp. lusitanica (Chaytor) Franco, on the antioxidant activity, and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (Tyr) inhibitory capacities. Ten different NADES were used in this research and compared with conventional solvents. Ultrasound-assisted extraction (UAE) for 60 min proved to be the best extraction condition, and proline:lactic acid (1:1) and choline chloride:urea (1:2) extracts showed the highest total phenolic contents (56.00 ± 0.77 mgGAE/gdw) and antioxidant activity [64.35 ± 1.74 mgTE/gdw and 72.13 ± 0.97 mgTE/gdw in 2.2-diphenyl-1- picrylhydrazyl (DPPH) and 2.20 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, respectively]. These extracts also exhibited enzymes inhibitory capacity particularly against Tyr and AChE. Even so, organic acid-based NADES showed to be the best extractants producing extracts with considerable ability to inhibit enzymes. Twenty-four phenolic compounds were identified by HPLC-HRMS, being rosmarinic acid, ferulic acid and salvianolic acid B the major compounds. The results confirmed that the combination of UAE and NADES provide an excellent alternative to organic solvents for sustainable and green extraction, and have huge potential for use in industrial applications involving the extraction of bioactive compounds from plants.Grant SFRH/BD/145243/2019, UIDB/05183/2020info:eu-repo/semantics/publishedVersio

    Seasonal variability of oceanographic conditions off NW Galician waters influencing the early life trophic ecology of European hake Merluccius merluccius by stable isotope analysis

    Get PDF
    Stable isotopes of nitrogen (δ15N) and carbón (δ13C) have been used as tracers for analyzing the trophic ecology of European hake larvae collected during the winter and summer of 2012 off NW Galicia. The sampling times correspond to periods of high and low hake spawning activity, respectively. Trophic enrichment was analyzed using as baseline two different plankton size fractions, corresponding to micro- (55-200μm) and mesozooplankton (>200μm). During both seasons, the δ15N signatures of hake larvae showed higher values than the zooplankton fractions. The first survey carried out in late February was characterized by a preceding marked upwelling, low geostrophic velocities in the hydrographic circulation and an intense mixing of the water column. This environmental scenario is hypothesizing that originated a great nutrient availability for primary consumers showed its effect in the low δ15N values observed in plankton and hake larvae. During July, the environmental setting corresponded to period where the water column was stratified, an anticyclonic gyre was formed in the center of the study area that concentrated particles and weak upwelling conditions and strong geostrophic currents where found. This scenario was characterized hypothetically by low nutrient availability in which production is mainly based on regenerated nutrients which would explain the higher δ15N values found during this period. On the other hand, the greater δ13C values observed in summer in comparison to winter suggest differences in the energetic sources of carbon (Fig. 1). The discussion of results is centered in how oceanographic variability conditions signatures of stable isotope fractionation in the early life trophic food web influencing the variable trophic pathways of larval hake subject to contrasting environmental conditions, thereby affecting their larval nutritional condition as estimated by RNA/DNA ratios and the Fulton index. This study was financed by the projects: CRAMER-CTM2010-21856-CO3 y ECOPREGA-10MMA602021P

    Examination of the Feynman-Hibbs Approach in the Study of NeN_N-Coronene Clusters at Low Temperatures

    Get PDF
    Feynman-Hibbs (FH) effective potentials constitute an appealing approach for investigations of many-body systems at thermal equilibrium since they allow us to easily include quantum corrections within standard classical simulations. In this work we apply the FH formulation to the study of NeN_N-coronene clusters (N=N= 1-4, 14) in the 2-14 K temperature range. Quadratic (FH2) and quartic (FH4) contributions to the effective potentials are built upon Ne-Ne and Ne-coronene analytical potentials. In particular, a new corrected expression for the FH4 effective potential is reported. FH2 and FH4 cluster energies and structures -obtained from energy optimization through a basin-hoping algorithm as well as classical Monte Carlo simulations- are reported and compared with reference path integral Monte Carlo calculations. For temperatures T>4T> 4 K, both FH2 and FH4 potentials are able to correct the purely classical calculations in a consistent way. However, the FH approach fails at lower temperatures, especially the quartic correction. It is thus crucial to assess the range of applicability of this formulation and, in particular, to apply the FH4 potentials with great caution. A simple model of NN isotropic harmonic oscillators allows us to propose a means of estimating the cut-off temperature for the validity of the method, which is found to increase with the number of atoms adsorbed on the coronene molecule

    A Comparative Analysis of Soil Loss Tolerance and Productivity of the Olive Groves in the Protected Designation of Origin(PDO) Areas Norte Alentejano (Portugal) and Estepa (Andalusia, Spain)

    Get PDF
    Olive groves are Mediterranean systems that occupy more than 2.5 M ha in Spain and 0.352 M ha in Portugal. Assuming the differences between both countries in terms of olive grove regulation and considering their multifunctionality, it is useful to implement agronomic indices to estimate their sustainability. The Soil Loss Tolerance Index (SLTI) and the Soil Productivity Index (SPI) are two such indices. We calculated both indices in the Protected Designation of Origin (PDO) Norte Alentejano (Portugal). The SLTI index was adapted considering specific variables of the analysed olive groves (i.e., SLTIog). The values obtained were compared with those previously estimated for PDO Estepa (Spain). The negative impacts of erosion and the underlying agricultural practices on the sustainability of olive groves became evident, resulting in decreased soil productivity at the regional level. The SLTIog index showed higher values for crops, being a more realistic tool to analyse sustainability. A higher soil loss tolerance was detected for integrated groves in the PDO Norte Alentejano than for PDO Estepa due to the shorter age of olive cultivation in Portugal, with incipient soil impacts. These indices provide information on the degree of soil erosion, allowing farmers and decision-makers to apply practices to maximise the sustainability of olive groves.To the University Complutense of Madrid, for awarding the lead author a short-term fellowship through which this research could be carried out. To MED-Universidade de Évora (Portugal), for providing to the main author with the opportunity to jointly perform field work and analytical tasks in Portugal. The time devoted by J.M.-R. and T.P.-C. to retrieve and treat the data and to write and revise the article has received partial funding from the following sources: (a) FCT—Foundation for Science and Technology (Portugal) under the Project UIDB/05183/2020; (b) SUSTAINOLIVE research project (https://sustainolive.eu/?lang=en [accessed on: 29 March 2021]), funded by the PRIMA EU program. Lastly, we thank María Aurora Rodríguez Sousa for her support and advice

    PGF2α (250 mcg d-cloprostenol) Effectiveness of two Schemes for Estrus Induction in Brahman Bovine Females with Lasting Anestrus.

    Get PDF
    The reproductive behavior of Brahman breeding cows subject to estrus induction was assessed, at the “Rancho Bonito Farm”, Gamelotal area, Lara State, Venezuela. The experiment lasted 90 days, and was based on two estrus induction schemes (Progesterone + Estradiol Benzoate and Progesterone + PMSG). Following 72 h of treatment, 62.5 % of the  cows that received  P4  + PMSG  were fertilized; whereas the P4  + BE treatment induced fertilization of 25 % (P < 0.05). During the 90 days,  93.7 % of the cows that received P4  + PMSG, and 75 %  under  the P4  + BE treatment, were fertilized, which demonstrated the effectiveness of the schemes

    Niveles de colinesterasa sérica en caficultores del Departamento de Caldas, Colombia

    Get PDF
    Objetivo Determinar niveles de colinesterasa sérica en caficultores del departamento de Caldas y su asociación con factores demográficos y ocupacionales.Metodología Se realizó un estudio descriptivo, muestra de 1 098 agricultores del Alto Oriente y Centro Sur del Departamento de Caldas, por medio de una encuesta en la que se analizaron características del trabajador agrícola de tipo: sociodemográfico, ocupacional, clínicos y concentración de colinesterasa determinada con el método de Ellman.Resultados A nivel ocupacional, el 90,8 % de los agriculto es refirió riesgo de exposición directa a plaguicidas. El 3,8 % de las determinaciones analíticas de colinesterasa fueron anormales, se relacionó que el 75,6 % de los agricultores preparan la mezcladel insecticida, el 22,2 % tienen una frecuencia de aplicación en el cultivo más de dos veces por semana, el 37,8 % no emplea ropa de protección durante la jornada de fumigación. El tiempo de la última aplicación fue dentro del rango de uno a diez días demostrando que a menor tiempo de aplicación del insecticida, se presenta mayorinhibición de la enzima. Los plaguicidas más reportados fueron los de tipo organofosforado (58,6 %).Conclusiones El control de la exposición a plaguicidas se torna difícil porque la mayoría de trabajadores son de tipo informal. Se requiere fortalecer los programas de capacitación y campañas de sensibilización sobre los efectos de los plaguicidas en la salud, las medidas de higiene y seguridad en el trabajo. Los niveles bajos de colinesterasa sérica indican la absorción de una cantidad mínima de insecticidas inhibidores de la colinesterasa.Objective To determine the levels of serum cholinesterase in coffee growers from the Caldas department and its association with demographic and labor factors.Methodology A descriptive study was carried out in a sample of 1 098 farmers from the Upper East and South Center of the Caldas department, through a survey that analyzed characteristics such as sociodemographic, labor, and clinical conditions, as well as cholinesterase levels, determined by Ellman's method.Results Regarding the occupational aspect, 90.8 % of farmers reported a risk of direct exposure to pesticides. 3.8 % of the analytical determinations of cholinesterase were abnormal, which was related to the fact that 75.6 % of the farmers themselves prepare the mixture of the insecticide, 22.2 % spread the insecticide over their crops more thantwice a week, and 37.8 % do not wear protective clothing during the fumigation. The last fumigation was within the range of one to ten days, revealing that the shorter the time of application of the insecticide, the greater the inhibition of the enzyme. The mostfrequent pesticides were organophosphates (58.6 %).ConclusionsControlling pesticide exposure is difficult because most workers are self-employed. It is necessary to strengthen training programs and awareness campaigns regarding the effect of pesticides on health, as well as health and safety measures at the workplace. Low levelsof serum cholinesterase indicate the bsorption of a minimal amount of cholinesterase inhibiting insecticides

    Winter Forage Yield of Signal Grass (\u3cem\u3eBrachiaria brizantha \u3c/em\u3e(Hochst. Ex. A. Rich) R.D. Webster) at Different Cutting Frequency and N Fertilization

    Get PDF
    Signal grass (Brachiaria brizantha (Hochst. Ex. A. Rich) R.D. Webster) is widely grown in sub-humid tropical environments. In winter, shorter photoperiod and lower rainfall and temperatures reduce grass forage yield. Cutting frequency and N fertilization might reduce this negative effect (Whitehead, 1995; Pereira et al., 2014). The objective of the study was to determine winter forage yield total and by components of Signal grass under different cutting frequency and N fertilization

    Genotoxicity by Electromagnetic Fields

    Get PDF
    Modern life implies a constant exposure of living organisms to many sources of radiation, especially electromagnetic fields (EMFs) generated by our technological devices. The question of whether or not EMFs in the non-ionizing extremely low frequency (ELF) range can induce genotoxic effects is currently a subject of interest. People of industrialized societies are commonly exposed to EMFs and waves in a very broad range of frequencies, including power lines, telecommunications, and domestic and industrial equipment. In this review, we present controversial evidence from our research group and others of genotoxicity induced by ELF-EMFs, since scientific community consider EMF devices produce marginal amounts of energy, which does not justify any DNA alterations, together with conflicting laboratory results and few epidemiological studies. However, in 2002 the International Agency for Research on Cancer (IARC) categorized ELF-EMFs as being potential carcinogenic and genotoxic agents to humans. The aim of the present chapter is to discuss the role of ELM-EMFs on human genotoxicity

    Dinámica del agua y fitoquímicos durante el secado de rodajas de chile habanero rojo (Capsicum chinense)

    Get PDF
    Habanero pepper (Capsicum chinense) is a source of phytochemicals or bioactive compounds that have shown benefits in human health. For phytochemicals extraction process, a prior drying is required. Therefore, the aim of this study was to evaluate the effect of drying temperature (30, 50 and 70 degrees C) on total capsaicinoids and total carotenoids, and the coefficients of water diffusivity during drying of sliced red habanero pepper. The results show that the bioactive compounds, present a major stability at high temperature (70 degrees C), the effective diffusivity increased with drying temperature and the activation energy of the process was calculated to 39.575 kJ mol(-1) K-1. Several theoretical aspects of average water diffusivity are discussed
    corecore