SEM evidence for existence of an apical disc on the scolex of Clestobothrium crassiceps (Rudolphi, 1819): comparative results of various fixation techniques

The scolex of the bothriocephalidean cestode Clestobothrium crassiceps was studied by means of scanning electron microscopy (SEM). The comparative results of various fixation procedures and techniques are presented. The scolex of C. crassiceps is oval to globular and exhibits two deep bothria which appear in the form of two lobes separated by a longitudinal groove. At the apex of the scolex, resembling a beret, an apical disc is present (oval, flattened and with a sinuous edge). Our results are compared with those previously reported in other species of Clestobothrium. This study represents the first report which highlights the presence of an apical disc in the scolex of C. crassiceps. It describes the effects of different procedures applied to our material during preparation and a comparative analysis results obtained using these various methods.

SEM evidence for existence of an apical disc on the scolex of Clestobothrium crassiceps (Rudolphi, 1819): comparative results of various fixation techniques

The scolex of the bothriocephalidean cestode Clestobothrium crassiceps was studied by means of scanning electron microscopy (SEM). The comparative results of various fixation procedures and techniques are presented. The scolex of C. crassiceps is oval to globular and exhibits two deep bothria which appear in the form of two lobes separated by a longitudinal groove. At the apex of the scolex, resembling a beret, an apical disc is present (oval, flattened and with a sinuous edge). Our results are compared with those previously reported in other species of Clestobothrium. This study represents the first report which highlights the presence of an apical disc in the scolex of C. crassiceps. It describes the effects of different procedures applied to our material during preparation and a comparative analysis results obtained using these various methods.

Las 'escuelas democráticas' de Michael W. Apple y James A. Beane en nuestro contexto

Ressenya de: Rafael Feito y Juan Ignacio López (eds.): Construyendo escuelas democráticas. Barcelona: Hipatia, 2008.

L'Intrusisme professional a principis del segle XX. El Dr. James M. Munyon.

RESUM: Presentem al Dr. James M. Munyon, qui a principis del segle passat es dedicà a la manufactura i patent de remeis homeopàtics. Va ser perseguit per frau en múltiples ocasions però la seva gran fortuna li va permetre estendre el seu negoci fins a casa nostra, arribant a assolir grans cotes de popularitat. La revista ¡Cu-Cut! li dedicà tres caricatures els anys 1902 i 1903. A través de l"estudi de les mateixes hem pogut conèixer el Dr. Munyon, un intrús professional de principis del segle XX.

First record of Trithemis kirbyi Sélys, 1891 in Catalonia (Odonata, Libellulidae)

Trithemis kirbyi Sélys, 1891 is a native species from Africa and southern Asia, typically found in arid areas.

Berättelse om Kejsar Alexanders färd från Nissilä gästgifveri till staden Kajana under Hans majestäts senaste resa uti Stor-Furstendömet Finland om sommarn år 1819

Nimeke muilla kielillä:

Описанiе путешетвиiя государя Императора Александра 1., изъ станцiи Ниссиле въ город Каяну во время послѣднаго вояжа Его величества въ Ведикое княжество Финляндское лѣтомъ 1819 года

Schilderung der Fahrt des Kejsers Alexander von der Station Nissilä nach der Stadt Kaiana auf der letzten Reise Seiner Majestät in dem Gross-Fürstenthume Finland während des Sommers 1819.

Relation du trajet de l’Empereur Alexandre de la station Nissilä à la ville de Kaïana duran le dernier voyage de sa majesté dans le Grand Duché de Finlande pendant l’été 1819.

História da química e da geologia: Joseph Black e James Hutton como referências para educação em ciências

The second half of eighteenth century is marked by the advancement of chemistry and geology. The first science acquired the law of conservation of mass and this science represented a important support to geology and mineralogy. We say that both became modern science that time. Our aim is to show up some interrelations between history of chemistry and history of geology by means of the study of Joseph Black's and James Hutton's works. We defend that it is positive to science education to understand and approach the relations among different and disciplinary areas of science.

Laboratório químico-prático do Rio de Janeiro: primeira tentativa de difusão da Química no Brasil (1812- 1819)

Until the present date, historians of science have described inaccurately the first laboratory created in Brazil for establishing and divulging Chemistry, namely the "Laboratório Químico-Prático do Rio de Janeiro". During recent research carried out in the Arquivo do Museu Imperial (Petrópolis, RJ), I localized a document entitled "Ensaio histórico analítico das operações do Laboratório Químico-Prático do Rio de Janeiro", which allowed me to gain the relevant information to correct some of the observations made in the first chronicles.

O Platonismo de Russell na metafísica e na matemática

Neste artigo, analiso o surgimento e a superação do Platonismo em B. Russell, tanto na sua filosofia da matemática como na sua metafísica. Começo por explicitar os argumentos que levaram Russell a aderir ao chamado "Platonismo Proposicional" - posição que será tecnicamente relevante na definição de números. Na seção seguinte, discutirei até que ponto a teoria das descrições definidas determina, necessariamente, uma adesão ao nominalismo, e as dificuldades que surgem para o logicismo conseqüentes do abandono do platonismo. Finalmente, mostrarei como a posição madura de Russell caracteriza-se mais como um reducionismo do que propriamente como um nominalismo, e como este é fundado no princípio do mínimo vocabulário.