Pollen-ovule ratio,pollen size,and breeding system in Astragalus (Fabaceae) subgenus Epiglottis: a pollen and seed allocation approach

The correlation between pollen/ovule (P/O) ratio and breeding system has generally been accounted for either on the basis that P/O reflects pollination efficiency, or in terms of the sex allocation theory. The following were assessed for taxa belonging to genus Astragalus subgenus Epiglottis: 1) Degree of correlation between P/O and the breeding system, measured by means of autofertility; 2) The absence or existence of correlation between P/O and pollen grain size; and 3) The ability of various theories to account for the results obtained. Results showed a minimal correlation between P/O and autofertility, and between P/O and pollen grain size in the taxa studied. Analysis of these results in terms of the sex allocation theory enabled this correlation to be explained as a function of the variation existing between taxa with respect to the resources invested in each pollen grain and in each ovule. The predictive capacity of this theory, which has moreover proven valuable in explaining the structural peculiarities of the androecium in these taxa, was also highlighted. The type of self-pollination applicable was also discussed, as was the phenotypic model of selection of self-fertilization considered most plausible for these taxa.     

Evaluation of Probiotic Properties of Novel Brazilian Lactiplantibacillus plantarum Strains

Probiotics and Antimicrobial Proteins - Beneficial effects of Lactiplantibacillus plantarum strains have been widely reported. Knowing that the effects of probiotic bacteria are strain-dependent,...     

Androgen receptors in the rat epididymis and their hormonal control.

The concentrations of cytoplasmic receptor sites for androgens in the caput, corpus and cauda epididymidis, and the effect of ligation of the efferent ducts and testosterone treatment after bilateral castration on the concentration of receptors in the caput have been measured. Androgen receptors in the ventral prostate have been measured in the same animals for comparison. The caput has the highest concentration of receptor sites, the corpus the lowest. The ligation of the efferent ducts has no effect on this concentration which is dependent on testicular androgens. The present data do not yet allow explanation of the differential response of the different regions of the epididymis and of the other accessory glands to the administration of androgens.     

Effects of lesions in the pontine tegmentum on the sleep stages in the rat]

1. Limited coagulations of the locus coeruleus and subcoeruleus nuclei have been performed in rats and the sleep-waking cycle was continuously monitored during 9 days. The cortical and diencephalic noradrenaline content was mesured at the termination of the experiment, on the 10th post lesion day. 2. The bilateral destruction of the locus coeruleus is followed by the appearance of a uro-genital syndrome consisting of hema turia, bladder distension and penile erection. The states of sleep are disturbed during the first two days (increase of slow-wave sleep and decrease of paradoxical sleep times) and thereafter return to normal. Additionally, an hyperthermia appears during the third experimental day. The cortical and diencephalic noradrenaline content decrease to 70%. 3. The simultaneous lesion of both locus coeruleus and subcoeruleus nuclei is followed by the appearance of an aphagia adipsia syndrome in addition to the uro-genital syndrome. After these lesions, it is no long possible to find paradoxical sleep episodes in polygraphic recordings while the amount of slow wave sleep is normal. Cortical and diencephalic noradrenaline content decrease more than 50%. 4. In normal rats direct injection of 6 hydroxydopamine directly in both locus coeruleus and nuclei subcoeruleus had no discernable effects either on the behaviour or on the states of sleep. The cortical noradrenaline content decreased 30% below control values. 5. These results are consistent with but do not prove the hypothesis that part of the pontine tegmentum might play an important role in triggering paradoxical sleep episodes. The role of these regions in the regulation of internal temperature, food consumption and bladder motricity is also discussed.     

Development of a bioadhesive nanoformulation with Glycyrrhiza glabra L. extract against Candida albicans

Abstract

Glycyrrhiza glabra L. is considered an important source of bioactive compounds. This study aimed at the development of an efficient solution for the treatment of oral candidiasis. Several extracts of Glycyrrhiza glabra L. were prepared using different solvents and their potential in vitro antifungal activity was assessed. Ethanolic extracts showed the most promising results against C. albicans. This extract was incorporated into mucoadhesive nanoparticles (PLA, PLGA and alginate), which were further included in an oral gel, an oral film and a toothpaste, respectively. The results showed that nanoparticles were successfully produced, presenting a mean size among 100–900?nm with high encapsulation efficiency. In vitro studies showed that the most bioadhesive formulation was the oral film with extract-loaded PLGA nanoparticles, followed by the toothpaste with extract-loaded alginate nanoparticles and the oral gel with extract-loaded PLA nanoparticles.     

Maternal-Fetal Distribution of Calcium,Iron, Copper,and Zinc in Pregnant Teenagers and Adults

Adolescence is marked by intensive growth and development. When pregnancy occurs during this period of the mother’s growth, there is an increase in her nutritional needs. The aim of this study was to determine the levels of calcium, iron, copper, and zinc in maternal plasma, the placenta, and in the cord plasma of pregnant teenagers and adults. A total of 80 sets of maternal plasma, placentas, and cord plasma (40 from teenagers and 40 from adults) were analyzed using synchrotron radiation total reflection X-ray fluorescence. The levels of calcium, copper, and zinc in the maternal and cord plasma from teenagers were not significantly different than those from adults. Iron levels in the teenagers maternal and cord plasma were higher than in the adults. All of the minerals analyzed were present at higher levels in the placentas from adults than those from teenagers. However, the low quantities of placental calcium, iron, copper, and zinc in the teenagers do not compromise the levels of these minerals in the cord plasma. Future research regarding the placental transport of these minerals is recommended to investigate the efficiency of mechanisms of transfer of these minerals in pregnant teenagers.