Crop photoperiodism model 2.0 for the flowering time of sorghum and rice that includes daily changes in sunrise and sunset times and temperature acclimation.

BACKGROUND AND AIMS: Daylength determines flowering dates. However, questions remain regarding flowering dates in the natural environment, such as the synchronous flowering of plants sown simultaneously at highly contrasting latitudes. The daily change in sunrise and sunset times is the cue for the flowering of trees and for the synchronization of moulting in birds at the equator. Sunrise and sunset also synchronize the cell circadian clock, which is involved in the regulation of flowering. The goal of this study was to update the photoperiodism model with knowledge acquired since its conception. METHODS: A large dataset was gathered, including four 2-year series of monthly sowings of 28 sorghum varieties in Mali and two 1-year series of monthly sowings of eight rice varieties in the Philippines to compare with previously published monthly sowings in Japan and Malaysia, and data from sorghum breeders in France, Nicaragua and Colombia. An additive linear model of the duration in days to panicle initiation (PI) and flowering time using daylength and daily changes in sunrise and sunset times was implemented. KEY RESULTS: Simultaneous with the phyllochron, the duration to PI of field crops acclimated to the mean temperature at seedling emergence within the usual range of mean cropping temperatures. A unique additive linear model combining daylength and daily changes in sunrise and sunset hours was accurately fitted for any type of response in the duration to PI to the sowing date without any temperature input. Once calibrated on a complete and an incomplete monthly sowing series at two tropical latitudes, the model accurately predicted the duration to PI of the concerned varieties from the equatorial to the temperate zone. CONCLUSIONS: Including the daily changes in sunrise and sunset times in the updated photoperiodism model largely improved its accuracy at the latitude of each experiment. More research is needed to ascertain its multi-latitudinal accuracy, especially at latitudes close to the equator.

[Melanoma of the penis]. / Melanoma de pene.

We present a case of penile malignant melanoma. Its rarity of less than 1% of masculine genital malignant neoplasms, the absence of standardised protocols as for other neoplasms, impel us to its publication.

Melanoma de pene / Melanoma of the penis

Presentamos un caso de melanoma maligno de pene. Su rareza inferior al 1 por ciento de las neoplasias malignas de genitales masculinos, la ausencia de protocolos estandarizados como para otras neoplasias, nos impulsan su publicación (AU)

Pirifibrate in the treatment of hyperlipoproteinemias: a multicenter study.

Pirifibrate, a new hypolipemic substance, was studied in a multicenter trial for three months in 151 patients diagnosed as having type IIa, IIb or IV hyperlipoproteinemia (HLP). The patients admitted into the study had not received any hypolipemic medication for four weeks immediately before the study. We observed falls of between 24.3% and 20.0% in the average levels of plasma cholesterol in types IIa and IIb HLP. The triglycerides showed a decrease in average values, which varied between 31.0% and 38.6% in types IIb and IV HLP. The alpha-lipoproteins always increased in three types of HLP studied, while the pre-beta-lipoproteins showed a fall in averages in types IIb and IV HLP. The beta-lipoprotein levels were reduced in type IIa HLP and reached statistical significance.