Fourth cranial nerve palsy and brown syndrome: two interrelated congenital cranial dysinnervation disorders?

Based on neuroimaging data showing absence of the trochlear nerve, congenital superior oblique palsy is now classified as a congenital cranial dysinnervation disorder. A similar absence of the abducens nerve is accompanied by misinnervation to the lateral rectus muscle from a branch of oculomotor nerve in the Duane retraction syndrome. This similarity raises the question of whether some cases of Brown syndrome could arise from a similar synkinesis between the inferior and superior oblique muscles in the setting of congenital superior oblique palsy. This hypothesis has gained support from the confluence of evidence from a number of independent studies. Using Duane syndrome as a model, we critically review the accumulating evidence that some cases of Brown syndrome are ultimately attributable to dysgenesis of the trochlear nerve.

Chef Charles Says..., November 2012

The Food Assistance Program provides nutrition assistance to people with low income. Food Assistance can help you buy nutritious foods for a better diet. Produced bye Iowa’s Food Assistance Program, Department of Human Services.

Chef Charles Says..., December 2012

The Food Assistance Program provides nutrition assistance to people with low income. Food Assistance can help you buy nutritious foods for a better diet. Produced bye Iowa’s Food Assistance Program, Department of Human Services.

Chef Charles Says..., January 2013

The Food Assistance Program provides nutrition assistance to people with low income. Food Assistance can help you buy nutritious foods for a better diet. Produced bye Iowa’s Food Assistance Program, Department of Human Services.

Chef Charles Says..., Instructors’ Guide, December 2012

The Food Assistance Program provides nutrition assistance to people with low income. Food Assistance can help you buy nutritious foods for a better diet. Produced bye Iowa’s Food Assistance Program, Department of Human Services.

Chef Charles Says..., Instructors’ Guide, November 2012

The Food Assistance Program provides nutrition assistance to people with low income. Food Assistance can help you buy nutritious foods for a better diet. Produced bye Iowa’s Food Assistance Program, Department of Human Services.

Chef Charles Says..., Leaders Guide, January 2013

The Food Assistance Program provides nutrition assistance to people with low income. Food Assistance can help you buy nutritious foods for a better diet. Produced bye Iowa’s Food Assistance Program, Department of Human Services.

Catalogue des livres manuscrits et imprimés composant la bibliothèque de M. Charles Sauvageot,... avec une notice biographique par M. Le Roux de Lincy. [Vente le 3 décembre 1860, maison Silvestre.]

[Vente (Livres). 1860-12-03. Paris]

Clinal variation in a brown lemur (Eulemur spp.) hybrid zone: Combining morphological, genetic and climatic data to examine stability.

Studies of hybrid zones can inform our understanding of reproductive isolation and speciation. Two species of brown lemur (Eulemur rufifrons and E. cinereiceps) form an apparently stable hybrid zone in the Andringitra region of south-eastern Madagascar. The aim of this study was to identify factors that contribute to this stability. We sampled animals at 11 sites along a 90-km transect through the hybrid zone and examined variation in 26 microsatellites, the D-loop region of mitochondrial DNA, six pelage and nine morphological traits; we also included samples collected in more distant allopatric sites. Clines in these traits were noncoincident, and there was no increase in either inbreeding coefficients or linkage disequilibrium at the centre of the zone. These results could suggest that the hybrid zone is maintained by weak selection against hybrids, conforming to either the tension zone or geographical selection-gradient model. However, a closer examination of clines in pelage and microsatellites indicates that these clines are not sigmoid or stepped in shape but instead plateau at their centre. Sites within the hybrid zone also occur in a distinct habitat, characterized by greater seasonality in precipitation and lower seasonality in temperature. Together, these findings suggest that the hybrid zone may follow the bounded superiority model, with exogenous selection favouring hybrids within the transitional zone. These findings are noteworthy, as examples supporting the bounded superiority model are rare and may indicate a process of ecologically driven speciation without geographical isolation.