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International audience; Bimetallic Ni2xMn2−2xP2S6phases, where 2X= 0.4 (Ni0.4), 0.8 (Ni0.8) and 1.2 (Ni1.2), were synthesized by a microwave assisted method, starting from the corresponding potassium intercalates K0.8Mn1.6P2S6·2H2O, K0.8Ni0.4Mn1.2P2S6·2H2O, and K0.8Ni0.8Mn0.8P2S6·2H2O. The magnetic, optical, and electrical properties were recorded, in order to visualize the influence of the secondary nickel(ii) ions on the physical properties of the pristine Mn2P2S6phase. Both dc susceptibility and EPR data show that the antiferromagnetic interactions are attenuated in the layers of the bimetallic phases, while the critical temperature remains constant (ca.80 K) for all the bimetallic phases, similar to that of Mn2P2S6. Conversely, the absorption edge of the solid state UV-visible spectra shifted to lower energies as the percentage of nickel(ii) increased, tending to that of the band gap value of the pristine Ni2P2S6phase. Moreover, the electric conductivity ofNi0.4was similar to that of the pristine Mn2P2S6phase, while that ofNi0.8andNi1.2approached the values of the electric conductivity of the pristine Ni2P2S6phase. On the other hand, the potassium intercalates K0.8Mn1.6P2S6·2H2O and K0.8Ni0.4Mn1.2P2S6·2H2O showed magnetization at 16 K, the latter being much weaker as compared to the first. The detrimental effect of the secondary nickel(ii) ions in the layers of the bimetallic phases became evident for K0.8Ni0.8Mn0.8P2S6·2H2O, where the magnetization at low temperatures was not observed. The absorption edge shifted to higher energy values for K0.8Mn1.6P2S6·2H2O and K0.8Ni0.4Mn1.2P2S6·2H2O, as compared to Mn2P2S6andNi0.4, respectively, but the value remained close to that of Ni2P2S6for K0.8Ni0.8Mn0.8P2S6·2H2O. InNi0.8andNi0.4, the electrical conductivity at low frequencies stems from polarization processes such as Maxwell/Wagner/Sillars electrode polarization. Moreover, an additional polarization process is observed in the intercalates because K+ions in the interlayer act as charge transport carriers. Consequently, the interacalates present higher electrical conductivity compared with the pristine Mn2P2S6phase, by a factor ofca.102 © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021.

Problème: Pour des raisons principalement économiques et climatiques, la monoculture de maïs dans le Béarn est le système de référence depuis plus de 60 ans. Cependant, ce système se confronte à des limites techniques et réglementaires. Ce système de culture nécessite des apports azotés significatifs et peut souffrir de fortes pressions des adventices (telles que la sétaire, le datura, le liseron, etc.) ainsi que de dégâts causés par les bio-agresseurs (taupin, pyrale du maïs, sésamie, etc.). En outre, ce système doit également faire face à l'évolution de la réglementation de la PAC, qui demande à respecter une exigence de diversification de la rotation des cultures. Solution: Pour réduire ces pressions et faire face aux réglementations de la PAC, 8 systèmes de culture diversifiés et innovants ont été évalués ces 3 dernières années sur la plateforme expérimentale Syppre du Béarn. Le système innovant basé sur une rotation maïs-soja de 2 ans avec une culture intermédiaire d'avoine a donné des résultats tout à fait satisfaisants notamment d’un point de vue économique et envrionnemenal. L’introduction du soja dans la rotation permet d’avoir droit à l’aide couplée.

Resumen En el modelo de amortización de préstamos a interés simple con cuotas uniformes vencidas y periodos de cuota uniformes, pueden identificarse dos tipos: Tipo 1: Todas las cuotas del préstamo amortizan principal. Tipo 2: Préstamos con interés simple cuando el principal queda cancelado antes de la última cuota. Utiliza una ecuación de equivalencia financiera a interés simple, que toma como fecha focal el final del horizonte del préstamo y calcula en ese momento el importe de la cuota uniforme, luego se sistematiza en un algoritmo matemático y se resuelve con la construcción de una función personalizada denominada Rsim, que se incorpora como un complemento add-in en Excel y permite plantear modelos automatizados de amortización de préstamos con cuotas uniformes, en periodos uniformes y con interés simple. Este artículo es el producto de nuestro proyecto de investigación Matemática Financiera: anualidades y perpetuidades, sistematizado en la función Rsim de nuestra propiedad intelectual, realizado con el apoyo de la Universidad Nacional del Callao. El objetivo de la investigación es hallar una ecuación de equivalencia financiera a interés simple que se aplique indistintamente para cualquier tipo de amortización de préstamos con cuotas uniformes que devengan interés simple, y su propósito es desarrollar un algoritmo que sistematice la ecuación de equivalencia de modo que sea utilizado por académicos y especialistas en costos financieros. La metodología utilizada es inducción-deducción en las que se consideraron las fases de observación, deducción y experimentación. Para cualquier caso de préstamos que devengan interés simple, el estudio concluye que si se utiliza el algoritmo Rsim se obtiene la verdadera equivalencia financiera que evita el anatocismo, lo que se comprueba al formular la tabla de amortización del préstamo. Abstract In the amortization model of simple interest loans with uniform quotas due and uniform quota periods, two types, can be identified: Type 1: All loan installments repay principal. Type 2: Loans with simple interest when the principal is canceled before the last installment. It uses an equation of financial equivalence at simple interest, which takes as focal date the end of the horizon of the loan and calculates at that time the amount of the uniform fee, which is then systematized in a mathematical algorithm that is solved with the construction of a function Called, Rsim, which is incorporated as an add-in Excel add-in and allows to propose automated loan repayment models with uniform rates, in uniform periods and with simple interest. This article is the product of our research project Financial Mathematics: annuities and perpetuities, systematized in the Rsim function of our intellectual property, made with the support of the National University of Callao. The objective of the investigation is a simple financial debt consolidation method that applies indistinctly to any kind of loan repayment with uniform interest-bearing rates, and its objective is Develop an algorithm that systematizes the equivalence equation so that both academics and financial cost specialists use it. The methodology used is induction-deduction in which the phases of observation, deduction and experimentation we are observed. The study concludes that, for any case of simple interest loans, using the Rsim algorithm gives the true financial equivalence that avoids the anatocism, which verified when formulating the loan repayment table.

The study aimed to quantify the bias from parasite detection methods in the estimation of the prevalence of infection of Triatoma infestans by Trypanosoma cruzi, the agent of Chagas disease. Three common protocols that detect T. cruzi in a sample of 640 wild-caught T. infestans were compared: (1) the microscopic observation of insect fecal droplets, (2) a PCR protocol targeting mini-exon genes of T. cruzi (MeM-PCR), and (3) a PCR protocol targeting a satellite repeated unit of the parasite. Agreement among protocols was computed using Krippendorff K. The sensitivity (Se) and specificity (Sp) of each protocol was estimated using latent class models. The PCR protocols were more sensitive (Se > 0.97) than microscopy (Se = 0.53) giving a prevalence of infection of 17-18%, twice as high as microscopy. Microscopy may not be as specific as PCR if Trypanosomatid-like organisms make up a high proportion of the sample. For small T. infestans, microscopy is not efficient, giving a prevalence of 1.5% when PCR techniques gave 10.7%. The PCR techniques were in agreement (K = 0.94) but not with microscopy (K never significant with both PCR techniques). Among the PCR protocols, the MeM-PCR was the most efficient (Se=1; Sp=1).

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