Brooding comatulids from the southwestern Atlantic, Argentina (Echinodermata: Crinoidea)

Isometra vivipara and Phrixometra nutrix are two brooding feather stars (order Comatulida) that are widely distributed along the southern tip of South America to the Antarctic. We examined 210 specimens of I. vivipara and 38 specimens of P.nutrix collected during five cruises in the southwestern Atlantic between 91 and 642 m depth. Specimens were analyzed and deposited in the National Invertebrate collection, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Isometravivipara reaches an arm length of 49 mm long and shows two stages of brooding: in the female genital pinnules and on the cirri of the mother. In this paper, we propose that spermatozoa reach the ovary via the ambulacral groove. By contrast, P. nutrix is smaller with a maximum recorded size of 26.8 mm, and brooding occurs only inside the female genital pinnules. Here, we record, for the first time for P.nutrix, spermatozoa shape and a cleaved egg attached externally to a genital pinnule of a female. The distributions of both species and their abundances in some areas could be related to their doliolaria larval stage. In addition, we extend the bathymetric range of P.nutrix to 512 m in Marine Protected Area Namuncurá/Burdwood Bank and distribution to the Mar del Plata Submarine Canyon area. We also propose mode of reproduction and developmental patterns as attributes for identification and possible explanations for their differences in distribution.Fil: Pertossi, Renata Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Penchazadeh, Pablo E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidad Simón Bolívar; VenezuelaFil: Martinez, Mariano Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Primary headaches in prescool age children: clinical study and follow-up in 163 patients.

Although headache frequency is increasing in preschool age children, an extensive evaluation of the clinical features in affected patients has yet to be achieved. This retrospective study examined 243 patients who were separately analysed in two distinct groups according to the age of onset and the age of first clinical evaluation. Group 1 included preschool age children, while Group 2 consisted of pubertal age patients. In all the patients the importance of a positive family history for headache as a risk factor was confirmed. In addition, when compared with Group 2, Group 1 showed greater male gender prevalence and earlier onset of the attacks. Regarding clinical features, in Group 1, compared with Group 2, the attack duration was shorter with lower symptom association such as photo- or phonophobia, nausea and no pain increase during physical activity. In the same group, tension-type headache was the predominant diagnosis, in contrast to the high migraine prevalence of Group 2. This study also showed that the International Headache Society 1988 classification criteria are not fully adequate for juvenile headaches. In fact, the headaches of more than 10% of patients in Group 1 still remained unclassifiable, while those of all the subjects in Group 2 were properly classifiable