Fate maps and gene expression in normal and abnormal facial primordia of chick embryos

This thesis investigates the cellular and molecular basis of shaping of facial primordia during normal and abnormal primary palate formation in chick embryos. DiI fate maps of facial primordia indicate that local differences in expansion between cell populations and directed expansion of cell populations shape the face and mediate outgrowth. Examination of patterns of cell proliferation, cell death and cell intercalation showed that these cell activities make important contributions to expansion. Application of retinoic acid to chick embryos results in primary palate clefting. Fate maps showed this is due to decreased expansion and proliferation in cell populations contributing directly to primary palate formation. However, other cell populations in the upper face expanded more uniformly, apparently due to loss of tension normally created by primary palate formation. Thus changes in behaviour in a few cell populations lead to global changes in facial shape. Cellular behaviour is coordinated by signalling molecules. Connexins 43 and 32, gap junction proteins mediating cell-cell signalling, were found to be expressed in regions of greatest mesenchymal expansion in the face. Retinoic acid treatment reduces expression of connexin 43 in cell populations forming the primary palate. Application of connexin 43 antisense oligodeoxynucleotides to the chick face results in facial clefting. Signalling via epithelial-mesenchymal interactions are also necessary for shaping. Removal of ectoderm from maxillary primordia in ovo resulted in reduced outgrowth. FGF, an ectodermal signal, rescues outgrowth, but does not maintain mesenchymal Msx-1 expression. BMP, another ectodermal signal, does not increase outgrowth but maintains Msx-1 expression. Eph4A, expressed in overlapping domains with Msx-1 in the face, is also dependent on an ectodermal signal, FGF, for maintained expression. These results are consistent with the idea that cell signalling via gap junctions and between epithelium and mesenchyme control cell behaviour that lead to primary palate formation

Like a hole in the head: Development, evolutionary implications and diseases of the cranial foramina

Cranial foramina are holes in the skull through which nerves and blood vessels pass to reach both deep and superficial tissues. They are often overlooked in the literature; however they are complex structures that form within the developing cranial bones during embryogenesis and then remain open throughout life, despite the bone surrounding them undergoing constant remodelling. They are invaluable in assigning phylogeny in the fossil record and their size has been used, by some, to imply function of the nerve and/or blood vessel that they contained. Despite this, there are very few studies investigating the development or normal function of the cranial foramina. In this review, we will discuss the development of the cranial foramina and their subsequent maintenance, highlighting key gaps in the knowledge. We consider whether functional interpretations can be made from fossil material given a lack of knowledge regarding their contents and maintenance. Finally, we examine the significant role of malformation of foramina in congenital diseases such as craniosynostosis

The Recruitment and Description of UniversityStudents who Self-Report Difficulty Acquiring Early Reading Skills

Self-report is a time- and cost-efficient screening measure that has the potential to be useful as a stand-alone means of recruiting adults for participation in reading research.We report on a sample of university students (N = 46) recruited using the Adult Reading History Questionnaire – Revised, half of whom reported early difficulty with reading acquisition. As a group, those reporting early difficulty with reading had poorer current reading skills than those who did not. Some (n = 13) of those who reported early reading difficulty appear to have compensated for this. We conclude that self-report has the potential to be used as an effective screening measure in research targeting adults with a history of early reading difficulties

Le français en république d’Irlande

En République d’Irlande, le français est en première position des langues étrangères étudiées, mais il est actuellement en recul, tandis que l’espagnol gagne en popularité dans les lycées irlandais. La langue française occupe pourtant de nos jours une place significative au sein du tissu social irlandais et c’est l’une des langues officielles des partenaires économiques non anglophones les plus importants de l’Irlande. La diminution actuelle de l’intérêt pour le français en Irlande peut s’expliquer par différents facteurs tels que le caractère facultatif de l’apprentissage des langues étrangères à l’école, les résultats relativement médiocres des candidats à l’épreuve de français du Leaving Certificate et le fait que l’Espagne soit une destination privilégiée des Irlandais. La défense du français en Irlande repose donc sur les organisations locales qui doivent notamment assurer son enseignement aux enfants et encourager les adultes à visiter des pays francophones.French is the most studied foreign language in the Republic of Ireland but its importance is currently declining, whereas Spanish is becoming more and more popular in Irish secondary schools. Yet, the French language still holds a significant position within Irish society and it is one of the official languages of the most important non-English-speaking economic partners of Ireland. The current decrease in the interest for French in Ireland can be accounted for by various factors such as the non-compulsory nature of foreign languages in schools, the relatively mediocre results of the candidates to the Leaving Certificate French examination, and the popularity of Spain as a destination for Irish people. The defense of the French language in Ireland rests therefore with the local organizations which must make sure that it is available at primary level and encourage adults to visit countries where French is spoken

Diriger les apprenants vers de nouvelles pratiques de la prononciation contextualisée à distance avec un blog audio

This article concerns the development of a hybrid learning system involving the use of a Voxopop audioblog at Alliance Française de Cork (Ireland) from September 2012 to May 2013 which aimed at better preparing teenage candidates to the French component of the Leaving Certificate national examination (estimated at level B1 of the Common European Framework of Reference). Pronunciation is of considerable importance, both in the oral examination (where it is not only assessed for itself but also affects the morphosyntactic and communicative performance of the candidate in the marking scheme) and also in a natural situation during exolingual interaction; we therefore used this Voxopop e-learning voice tool to improve the French pronunciation of the participants, especially as this aspect of the language seemed somewhat paradoxically neglected by most of our students’ post-primary teachers. The tasks that participants had to perform on the class blog consisted in recording their pre-corrected, individual presentations which were related to the topics of the aforementioned oral examination. Our evaluation of this experiment and the analysis of the data collected from students via two written questionnaires and two oral tests conducted before and after the use of the audioblog revealed that the new hybrid course enabled the extension of the oral preparation beyond the classroom, led participants to no longer neglect their phonemic and prosodic needs in French and made it possible for them to incorporate new and more appropriate ways of practicing pronunciation outside the classroom: the regular, monitored and more autonomous 'oralization' of their preparation, listening back to their own recordings, using lasting individualized corrective feedback and speaking online in a more authentic communicative environment with multiple potential listeners.

The role of embryo movement in the development of the furcula

The pectoral girdle is a complex structure which varies in its morphology between species. A major component in birds is the furcula, which can be considered equivalent to a fusion of the paired clavicles found in many mammals, and the single interclavicle found in many reptiles. These elements are a remnant of the dermal skeleton and the only intramembranous bones in the trunk. Postnatally, the furcula plays important mechanical roles by stabilising the shoulder joint and acting as a mechanical spring during flight. In line with its mechanical role, previous studies indicate that, unlike many other intramembranous bones, furcula growth during development can be influenced by mechanical stimuli. This study investigated the response of individual aspects of furcula growth to both embryo immobilisation and hypermotility in the embryonic chicken. The impact of altered incubation temperature, which influences embryo motility, on crocodilian interclavicle development was also explored. We employed whole‐mount bone and cartilage staining and 3D imaging by microCT to quantify the impact of rigid paralysis, flaccid paralysis and hypermobility on furcula growth in the chicken, and 3D microCT imaging to quantify the impact of reduced temperature (32–28 °C) and motility on interclavicle growth in the crocodile. This revealed that the growth rates of the clavicular and interclavicular components of the furcula differ during normal development. Total furcula area was reduced by total unloading produced by flaccid paralysis, but not by rigid paralysis which maintains static loading of embryonic bones. This suggests that dynamic loading, which is required for postnatal bone adaptation, is not a requirement for prenatal furcula growth. Embryo hypermotility also had no impact on furcula area or arm length. Furcula 3D shape did, however, differ between groups; this was marked in the interclavicular component of the furcula, the hypocleideum. Hypocleideum length was reduced by both methods of immobilisation, and interclavicle area was reduced in crocodile embryos incubated at 28 °C, which are less motile than embryos incubated at 32 °C. These data suggest that the clavicular and interclavicle components of the avian furcula respond differently to alterations in embryo movement, with the interclavicle requiring both the static and dynamic components of movement‐related loading for normal growth, while static loading preserved most aspects of clavicle growth. Our data suggest that embryo movement, and the mechanical loading this produces, is important in shaping these structures during development to suit their postnatal mechanical roles

Higher levels of CO2 during late incubation alter the hatch time of chicken embryos

status: publishe