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OBJECTIVE: Vitamin D blood levels have been shown to be partially dependent upon season in temperate climates, however, this same evaluation has not yet been reported in fully tropical climates. Herein, we assessed the vitamin D levels in the blood of Rhesus monkeys housed at the Puerto Rico Caribbean Primate Research Center collected in the island's "summer"(May-October) and "winter" (November-April) months. MATERIALS AND METHODS: In 2006 through 2014, repeated measurements of blood samples were collected from 5 Rhesus monkeys (IACUC-approved) during "summer" and "winter" months to assess 25-OH vitamin D, determined via HPLC. UV-B and UV-A (KJ/m2/day) were measured using a ground based radiometer for these time periods. A paired t-test and a multilevel mixed- effect model approach was performed for data analysis. RESULTS: The difference of the mean serum values of 25-OH vitamin D between seasons showed lower levels during "winter" than "summer" months. About 23% of the variance in levels can be attributed to difference between the monkeys. The means of UV-B and UV-A, as a proxy for sunlight intensity, were greater (over the entire study interval) during the "summer" as opposed to "winter" months (p < 0.001). CONCLUSION: Vitamin D levels were substantially higher in the "summer" rather than the "winter" months. This observation implies that even in fully tropical regions, such as Puerto Rico, time of year can have an influence on vitamin D status. While comparable studies have not been undertaken in humans, it would not be unreasonable to suggest that similar results would be obtained should such a study be done.

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The effectiveness of management plans developed for responding to coral disease outbreaks is limited due to the lack of rapid methods of disease diagnosis. In order to fulfill current management guidelines for responding to coral disease outbreaks, alternative methods that significantly reduce response time must be developed. Hyperspectral sensing has been used by various groups to characterize the spectral signatures unique to asymptomatic and bleached corals. The 2010 combined bleaching and Caribbean yellow band disease outbreak in Puerto Rico provided a unique opportunity to investigate the spectral signatures associated with bleached and Caribbean yellow band-diseased colonies of Orbicella faveolata for the first time. Using derivative and cluster analyses of hyperspectral reflectance data, the present study demonstrates the proof of concept that spectral signatures can be used to differentiate between coral disease states. This method enhanced predominant visual methods of diagnosis by distinguishing between different asymptomatic conditions that are identical in field observations and photographic records. The ability to identify disease-affected tissue before lesions become visible could greatly reduce response times to coral disease outbreaks in monitoring efforts. Finally, spectral signatures associated with the poorly understood Caribbean yellow band disease are presented to guide future research on the role of pigments in the etiology.

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The effects of increased UV radiation (UV-B [280-320 nm] + UV-A [320-400 nm]; hereafter UVR) on the growth, production of photosynthetic pigments and photoprotective mycosporine-like amino acids (MAAs) were studied in the threatened Caribbean coral Acropora cervicornis transplanted from 20 to 1 m depth in La Parguera, Puerto Rico. The UVR exposure by the transplanted colonies was significantly higher than that at 20 m, while photosynthetically active radiation (PAR) only increased by 9%. Photosynthetic pigments, quantified with HPLC, as well as linear extension rates and skeletal densities, were significantly reduced 1 month after transplantation to 1 m depth, while MAAs increased significantly despite immediate paling experienced by transplanted colonies. While these colonies showed a significant reduction in photosynthetic pigments, there were no significant reductions in zooxanthellae densities suggesting photoacclimation of the coral's symbionts to the new radiation conditions. The results suggest that while corals might be able to survive sudden increases in UVR and PAR, their skeletal structure can be greatly debilitated due to a reduction in the photosynthetic capacity of their symbionts and a possible relocation of resources.

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La apoptosis involucra una serie de episodios altamente organizados y programados que tienen por objeto mantener la estabilidad genómica eliminando células huésped defectuosas. El propósito de este estudio fue determinar las dosis umbral y los tiempos de exposición a UV-A y UV-B medioambientales suficientes como para producir apoptosis y necrosis en la células normales de una línea celular de fobroblastos humanos. Se midieron dosis de UV-A y UV-B durante un período de seis años con un radiómetro UV de cuatro canales. Se irradiaron los fibroblastos una vez utilizando Simuladores Solar UV Oriel con seis dosis de UV basados en el medio ambiente. Las dosis correspondieron a 0, 11, 19, 23 y 45 minutos de radiación ambiental de UV-A y UV-B al sol del mediodía en Puerto Rico. Se utilizó en método de unión de la anexina-V para diferenciar entre los fibroblastos normales y fibroblastos apoptóticos o necróticos. La dosis umbral de la apoptosis a la necrosis se halló entre 24-28 KJ/m2, correspondiente a los 19 y 23 minutos de exposición ambiental a UV-A y UV-B. Este estudio proporciona los primeros datos que especifican las dosis de umbral medioambientales de UV-A y UV-B en las que los fibroblastos humanos experimentas apoptosis y necrosis. Estos resultados pueden proporcionar valiosos umbrales dosis-respuesta de apoptosis y necrosis para futuros estudios mecanicistas y datos de línea de base para programas de prevención de cáncer de piel.

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The error in irradiance measured with Sun-calibrated multichannel radiometers may be large when the solar zenith angle (SZA) increases. This could be particularly detrimental in radiometers installed at mid and high latitudes, where SZAs at noon are larger than 50 degrees during part of the year. When a multiregressive methodology, including the total ozone column and SZA, was applied in the calculation of the calibration constant, an important improvement was observed. By combining two different equations, an improvement was obtained at almost all the SZAs in the calibration. An independent test that compared the irradiance of a multichannel instrument and a spectroradiometer installed in Ushuaia, Argentina, was used to confirm the results.