Annual Wave in the world-wide F-Region Ionization

An analysis of squares of noon median F2 layer critical frequencies for a 3-year period has been made in order to derive the latitude variation of the annual effect in the electron densities and its relation to average F21ayer ionization. The results indicate that the annual component varies with the latitude in a manner very nearly similar to that of the steady ionization R0 and that for a given value of Ro for any latitude. R1 which can be derived approximately from a linear relationship of the type Rl = 0.3 Ro-4.5. A similar analysis of 9-year data, for precise phase and amplitude of the annual component for a pair of stations yields a value of Rl which is of the same order of magnitude as Ro and which attains a maximum around the epoch of minimum sun-earth distance.

Influence of genetic background, growth latitude and bagging treatment on phenolic compounds in fruits of commercial cultivars and wild types of apples (Malus sp.)

Phenolic compounds in apples 17 cultivars (Malus domestica Borkh.) and 3 wild forms (Malus sp.) were analyzed to study the impact of genetic background, growth site, and fruit bagging. The impact of altitude was studied in nine cultivars by analyzing fruits collected from orchards at three altitudes. Procyanidin B2 (71–628 μg/g fresh weight), ( −)-epicatechin (35–357 μg/g), and chlorogenic acid (28–563 μg/g) were always the three most abundant phenolic compounds in the apple samples studied, except for the cultivar ‘Qinguan’, which had a very low content of ( −)-epicatechin (13 μg/g) and procyanidin B2 (8 μg/g). The wild apples of M. prunifolia (Willd.) Borkh were 5-times richer in epicatechin (278 μg/g) and procyanidin B2 (628 μg/g) than the commercial cultivars of M. domestica Borkh (86 and 54, respectively). Among the commercial cultivars, ‘Qinguan’ had the highest level of chlorogenic acid but the lowest content of flavan-3-ols, whereas ‘Liuyuehong’ was characterized by the highest content of quercetin glycosides. Procyanidin B2, and ( −)-epicatechin correlated negatively, while other phenolics positively, with altitude. The response of phenolic compounds to altitude variation depended on latitude variation and genetic backgrounds. Bagging treatment reduced the contents of most phenolic compounds, with the impact of cultivars and length of re-exposure before harvest. This is also the first report on phenolic compounds in several important new cultivars, adding new knowledge on the compositional characteristics of global apple resources.

Latitude dependence of the solar granulation during the minimum of activity in 2009

Context. Knowledge of the latitude variation of the solar granulation properties (contrast and scale) is useful to better understand interactions between magnetic field, convection, differential rotation, and meridional circulation in the solar atmosphere. Aims. We investigated the latitude dependence of the contrast and scale of the solar granulation, with the help of HINODE/SOT blue continuum images taken in the frame of the HOP 79 program, along the central meridian and along the equator on a monthly basis in 2009 during the last solar minimum of activity. Methods. We selected the sharpest images in latitude and longitude intervals. The selected images in all the N-S and E-W scans taken in 2009 were combined to get statistically reliable results. Results. The contrast of the solar granulation decreases towards the poles and the scale increases, but not regularly since a perturbation occurs at around 60° where both quantities return close to their values at the disk center. Conclusions. Such a latitude variation in a period of minimum of activity (2009), is probably not due to magnetic field, neither the quiet magnetic field at the surface, nor the strong magnetic flux tubes associated with active regions, which could be embedded more or less deeply in the convection zone before they reach the surface. The decrease in contrast and increase in scale towards the pole seem to be related to the differential rotation and the perturbation around 60° to the meridional circulation.