Seasonal and diel modulation of DOM in a mangrove-dominated estuary.

Rivers and estuaries are the main links between continents and oceans. The Paraíba do Sul River is among the most important rivers of the southeastern Brazilian region, carrying an average of 0.08 Tg of dissolved organic matter (DOM) to the ocean but has been facing significant changes in river discharge. In this study, we aimed to provide insights into the sources and transformations of chromophoric dissolved organic matter (CDOM) and fluorescent dissolved organic matter (FDOM) sources across a salinity gradient under changing river discharge scenarios. Three spatial surveys were performed covering the entire salinity gradient of the main estuarine channel and surrounding mangrove waters under contrasting river discharge (178 to 1240 m3 s-1), and diel sampling was conducted in the mangrove tidal creek. The characterization of DOM through the parallel factor analysis (PARAFAC) model identified six components across the river-ocean gradient and mangrove creek: terrestrial origin (C1 - fulvic acid and C2 and C3 - humic-like), protein-like (C4), tryptophan-like (C5), and tyrosine-like (C6). Our results showed a shift in DOM composition and contribution along the salinity gradient, from terrestrial (C3) to autochthonous (C5 and C6) signatures. The October-17 dry campaign was characterized by a higher proportion of microbial protein-like component C4 and a lower contribution of humic-like components compared to February-17 and March-18 across the salinity gradient with an increase in the mixing zone. The DOM compositions of the February 17 dry and March 18 wet campaigns were similar. Additionally, the March-18 wet campaign, marked by the highest river discharge, showed higher inputs of terrestrial DOM (C1-C3 components) compared to February-17 in the estuary, which allowed DOM to be transported rather than transformed. The mangrove diel study showed that tidal fluctuations are also an important driver of carbon input to the mangrove creek with a possible impact on DOM composition in estuarine waters.

[Severity and epidemiology of myoclonic epilepsy]. / Importancia y epidemiología de las epilepsias mioclónicas.

The author first reviews the definition of myoclonia as an epileptic crisis differentiated from tonic crises and infantile spasms. He reviews the prevalence and incidence found in bibliographic data, under the following headings 1. Early myoclonic encephalopathy or neonatal myoclonic encephalopathy 2. Early epileptic syndrome with bursts of suppression or Otahara's syndrome. 3. West's syndrome. 4. The benign myoclonic epilepsy syndrome of children. 6. Syndrome of myoclonic epilepsy in non-progressive encephalopathy. 7. Early myoclonic epilepsy of children or Dose's syndrome. 8. Lennox-Gastaut syndrome. 9. Syndrome of epilepsy with absences in children. 10. Myoclonic absence epilepsy syndrome. 11. Landau-Kleffner syndrome and the syndrome of continuous slow spike-and-wave epilepsy during slow sleep. 12. Photosensitive epilepsy. 13. Absence epilepsy in young patients. 14. Juvenile myoclonic epilepsy. 15. Syndrome of gran mal epilepsy on waking. 16. Progressive myoclonic epilepsies. The author reviews 6,450 cases, 408 patients who had myoclonic crises, that is 6.3%. The differences seen in this total group of patients were: the myoclonic crises which presented alone, myoclonic crises accompanied by simple typical absences, those initially accompanied by generalized tonic-clonic crises and those presenting typical absences, tonic-clonic generalized crises and myoclonus simultaneously. The course of the different groups is analyzed.