NISCAL: Near Infrared Spectroscopy Calibrator

Infrared spectroscopic observations are often accompanied by a comparison star (or “telluric”) to correct for rapidly varying atmospheric absorption that depend on observing conditions (eg. water vapor, temperature, air mass). Here we present NISCAL, a code that uses the spectrum of the observed star and a list of stellar spectra (synthetic or observed), to optimize the telluric correction and flux calibration, automating the search for the best fit, minimizing the contribution of the stellar spectrum to the transmission function, and following the errors to estimate the level of uncertainty in the final spectrum. NISCAL calculates the difference in radial velocity, searches for the spectrum that best fits the observed star, obtains the transmission function by removing the stellar spectrum, and applies the telluric correction to the science data. In addition, it offers a flux calibration with the magnitude of either the scientific source or the telluric star, or with data from a flux standard star, where all slit losses are considered based on the user-defined light profile. Its current version is for slit spectroscopy of point sources and is being developed for other spectroscopy modes. We present the effect of telluric correction and flux calibration on the signal-to-noise ratio of the final spectrum with observations of Flamingos-2 in Gemini South.Las observaciones espectroscópicas infrarrojas suelen ir acompañadas de una estrella de comparación (o "telúrica") para corregir la absorción atmosférica que varía rápidamente y depende de las condiciones de observación (por ejemplo, vapor de agua, temperatura, masa de aire). Aquí presentamos NISCAL, un código que utiliza el espectro de la estrella observada y una lista de espectros estelares (sintéticos u observados), para optimizar la corrección telúrica y la calibración del flujo, automatizando la búsqueda del mejor ajuste, minimizando el aporte de la estrella observada. espectro a la función de transmisión, y siguiendo los errores para estimar el nivel de incertidumbre en el espectro final. NISCAL calcula la diferencia de velocidad radial, busca el espectro que mejor se ajusta a la estrella observada, obtiene la función de transmisión eliminando el espectro estelar y aplica la corrección telúrica a los datos científicos. Además, ofrece una calibración de flujo con la magnitud de la fuente científica o de la estrella telúrica, o con datos de una estrella de flujo estándar, donde todas las pérdidas por rendija se consideran en función del perfil de luz definido por el usuario. Su versión actual es para espectroscopia de rendija de fuentes puntuales y se está desarrollando para otros modos de espectroscopia. Presentamos el efecto de la corrección telúrica y la calibración de flujo en la relación señal-ruido del espectro final con observaciones de Flamingos-2 en Gemini Sur.Fil: Diaz, Carlos Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Gaspar, G.. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Diaz, R. J.. Gemini Observatory; Estados Unido

NISCAL: Near Infrared Spectroscopy Calibrator

Infrared spectroscopic observations are often accompanied by a comparison star (or “telluric”) to correct for rapidly varying atmospheric absorption that depend on observing conditions (eg. water vapor, temperature, air mass). Here we present NISCAL, a code that uses the spectrum of the observed star and a list of stellar spectra (synthetic or observed), to optimize the telluric correction and flux calibration, automating the search for the best fit, minimizing the contribution of the stellar spectrum to the transmission function, and following the errors to estimate the level of uncertainty in the final spectrum. NISCAL calculates the difference in radial velocity, searches for the spectrum that best fits the observed star, obtains the transmission function by removing the stellar spectrum, and applies the telluric correction to the science data. In addition, it offers a flux calibration with the magnitude of either the scientific source or the telluric star, or with data from a flux standard star, where all slit losses are considered based on the user-defined light profile. Its current version is for slit spectroscopy of point sources and is being developed for other spectroscopy modes. We present the effect of telluric correction and flux calibration on the signal-to-noise ratio of the final spectrum with observations of Flamingos-2 in Gemini South.Las observaciones espectroscópicas infrarrojas suelen ir acompañadas de una estrella de comparación (o "telúrica") para corregir la absorción atmosférica que varía rápidamente y depende de las condiciones de observación (por ejemplo, vapor de agua, temperatura, masa de aire). Aquí presentamos NISCAL, un código que utiliza el espectro de la estrella observada y una lista de espectros estelares (sintéticos u observados), para optimizar la corrección telúrica y la calibración del flujo, automatizando la búsqueda del mejor ajuste, minimizando el aporte de la estrella observada. espectro a la función de transmisión, y siguiendo los errores para estimar el nivel de incertidumbre en el espectro final. NISCAL calcula la diferencia de velocidad radial, busca el espectro que mejor se ajusta a la estrella observada, obtiene la función de transmisión eliminando el espectro estelar y aplica la corrección telúrica a los datos científicos. Además, ofrece una calibración de flujo con la magnitud de la fuente científica o de la estrella telúrica, o con datos de una estrella de flujo estándar, donde todas las pérdidas por rendija se consideran en función del perfil de luz definido por el usuario. Su versión actual es para espectroscopia de rendija de fuentes puntuales y se está desarrollando para otros modos de espectroscopia. Presentamos el efecto de la corrección telúrica y la calibración de flujo en la relación señal-ruido del espectro final con observaciones de Flamingos-2 en Gemini Sur.Fil: Diaz, Carlos Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Gaspar, G.. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Diaz, R. J.. Gemini Observatory; Estados Unido

An approach to the construction of the carbon skeleton of marine nor-sesquiterpenes. Total synthesis of (±)-dehalo-napalilactone

We disclose herein a synthetic approach for the preparation of an unusual carbon skeleton, which was found in nor-sesquiterpenes isolated from marine corals. The main structural feature of this skeleton is the presence of two contiguous quaternary centers, one of them bears a spiro gamma-butyrolactone moiety. One of the quaternary centers was prepared with moderate stereoselectivity by the conjugate addition of lithium dimethylcuprate to 2-methylcyclohexenone, followed by the trapping of the intermediate enolate with allyl bromide to furnish trans-2-allyl-2,3-dimethylcyclohexan-2-one, as a major diastereoisomer. The preparation of the quaternary centers bearing the spiro gamma-butyrolactone moiety was secured by the addition of a suitably functionalized organolithium reagent on trans-2-allyl-2,3-dimetylcyclohexan-2-one, followed by separation of the isomers and two oxidation steps. This strategy has permitted us to report the racemic total synthesis of a non-natural nor-sesquiterpene derivative, in 6 steps and 16% overall yield, from 2-methylcyclohexenone.Nesse trabalho descrevemos uma abordagem sintética para a preparação de um esqueleto carbônico que tem dois centros quaternários vizinhos, um dos quais apresenta uma unidade espiro gama-butirolactona. Esse arranjo molecular é encontrado em nor-sesquiterpenos isolados de corais marinhos. A estratégia sintética utilizada se baseou no uso de uma reação de adição 1,4 do dimetilcuprato de lítio sobre a 2-metilcicloexenona, seguida da interceptação do enolato intermediário com brometo de alila, para obter a trans-2-alil-2,3-dimetilcicloexanona com moderada diastereosseletividade. Essa última já tem incorporada em sua estrutura um dos centros quaternários do esqueleto. O segundo centro quaternário, que porta a unidade espiro gama-butirolactona, foi preparado através de uma reação de adição de um reagente organolítio, seguido da separação dos isômeros e de etapas de oxidação. Essa estratégia permitiu obter o esqueleto carbônico dos sesquiterpenos e ao mesmo tempo relatar a síntese total de um derivado nor-sesquiterpênico não natural, em 6 etapas com um rendimento global de 16%, a partir da 2-metilcicloexenona.360367Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Antibacterial Chemical Constituent and Antiseptic Herbal Soap from Salvinia auriculata

The bioassay-guided isolation of the active extract of Salvinia auriculata Aubl. led to the separation of three main compounds, characterized as stigmasterone, stigmasterol, and friedelinol. The pure form of diketosteroid presented a potential antibacterial activity with a minimum inhibitory concentration (MIC) value of 0.01 mg mL−1 against Staphylococcus aureus isolated from animals with mastitis infections. The active extract also showed a similar result to that previously obtained with pure diketosteroid when tested with the same isolates. The present study’s results demonstrate the potential of this plant as an excipient for the production of antibacterial soaps aimed at controlling bovine mastitis infections, especially on small farms

Chemical constituents and an alternative medicinal veterinary herbal soap made from Senna macranthera

Upon undergoing biomonitoring, the most active dichloromethane extract retrieved from Senna macranthera roots led to the isolation of three main compounds: emodine, physione, and chrysophanol. In this sequence, these compounds revealed a potential antibacterial activity against Staphylococcus aureus strains isolated from animals with mastitis infections with minimum inhibitory concentration (MIC) values of 20, 90, and 90 μg mL−1, respectively. Therefore, an herbal soap was also produced from this same active extract. This soap was tested in vitro using gloves contaminated by animals with bovine mastitis that had been discarded after use by milkers and showed similar results to previously tested compounds. These results indicate the potential of this plant as an alternative veterinary medicine for the production of antibacterial soaps that aimed at controlling bovine mastitis infections in small Brazilian farms

A near-infrared view of Nearby Galaxies: The Case of NGC 6300

We present a near-infrared study of the Seyfert 2 galaxy NGC 6300, based on subarcsecond images and long slit spectroscopy obtained with Flamingos-2 at Gemini South. We have found that the peak of the nuclear continuum emission in the K s band and the surrounding nuclear disk are 25 pc off-center with respect to the center of symmetry of the larger scale circumnuclear disk, suggesting that this black hole is still not fixed in the galaxy potential well. The molecular gas radial velocity curve yields a central black hole upper mass estimation of . The Paβ emission line has a strongly asymmetric profile with a blueshifted broad component that we associate with a nuclear ionized gas outflow. We have found in the K s -band spectra that the slope of the continuum becomes steeper with increasing radii, which can be explained as the presence of large amounts of hot dust not only in the nucleus but also in the circumnuclear region up to r = 27 pc. In fact, the nuclear red excess obtained after subtracting the stellar contribution resembles to that of a blackbody with temperatures around 1200 K. This evidence supports the idea that absorbing material located around the nucleus, but not close enough to be the torus of the unified model, could be responsible for at least part of the nuclear obscuration in this Seyfert 2 nucleus.Fil: Gaspar, Gaia. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Diaz, Ruben Joaquin. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentina. Gemini Observatory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Observatorio Astronomico de la Universidad Nacional de Cordoba; ArgentinaFil: D'Ambra, A.. Observatorio Astronomico de la Universidad Nacional de Cordoba; ArgentinaFil: Agüero, Maria Paz. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gunthardt, Guillermo Ivan. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentin