Molecular heterogeneity of progenitors and radial migration in the developing cerebral cortex revealed by transgene expression.

We have analyzed the developmental pattern of beta-galactosidase (beta-gal) expression in the cerebral cortex of the beta 2nZ3'1 transgenic mouse line, which was generated using regulatory elements of the beta 2-microglobulin gene and shows ectopic expression in nervous tissue. From embryonic day 10 onward, beta-gal was expressed in the medial and dorsal cortices, including the hippocampal region, whereas lateral cortical areas were devoid of labeling. During the period of cortical neurogenesis (embryonic days 11-17), beta-gal was expressed by selective precursors in the proliferative ventricular zone of the neocortex and hippocampus, as well as by a number of migrating and postmigratory neurons arranged into narrow radial stripes above the labeled progenitors. Thus, the transgene labels a subset of cortical progenitors and their progeny. Postnatally, radial clusters of beta-gal-positive neurons were discernible until postpartum day 10. At this age, the clusters were 250 to 500 microns wide, composed of neurons spanning all the cortical layers and exhibiting several neuronal phenotypes. These data suggest molecular heterogeneity of cortical progenitors and of the cohorts of postmitotic neurons originating from them, which implies intrinsic molecular mosaicism in both cortical progenitors and developing neurons. Furthermore, the data show that neurons committed to the expression of the transgene migrate along very narrow, radial stripes.

Activin A inhibits Pax-6 expression and perturbs cell differentiation in the developing spinal cord in vitro.

We have developed an in vitro model of the isolated chicken neural plate. Here we demonstrate that even in the absence of notochord, the neural plate rapidly develops a typical dorsoventral patterning. This observation suggests that the ventral cell types are specified or at least predetermined prior to notochord formation and that permissive conditions are sufficient for differentiation of ventral structures. Treatment of the neural plate with activin A extinguishes Pax-6 gene expression, whereas the dorsal markers Pax-3 and Pax-7 are still expressed. The absence of Pax-6 transcripts can be correlated with an impeded differentiation of the motor neurons, whereas the floor plate seems to be enlarged. We propose that the region-specific expression of Pax-6 in the spinal cord is under the control of activin-like molecules.

Premature suture closure and ectopic cranial bone in mice expressing Msx2 transgenes in the developing skull.

The coordinate growth of the brain and skull is achieved through a series of interactions between the developing brain, the growing bones of the skull, and the fibrous joints, or sutures, that unite the bones. These interactions couple the expansion of the brain to the growth of the bony plates at the sutures. Craniosynostosis, the premature fusion of the bones of the skull, is a common birth defect (1 in 3000 live births) that disrupts coordinate growth and often results in profoundly abnormal skull shape. Individuals affected with Boston-type craniosynostosis, an autosomal dominant disorder, bear a mutated copy of MSX2, a homeobox gene thought to function in tissue interactions. Here we show that expression of the mouse counterpart of this mutant gene in the developing skulls of transgenic mice causes craniosynostosis and ectopic cranial bone. These mice provide a transgenic model of craniosynostosis as well as a point of entry into the molecular mechanisms that coordinate the growth of the brain and skull.

Primary structure of hepatocyte nuclear factor/forkhead homologue 4 and characterization of gene expression in the developing respiratory and reproductive epithelium.

Members of the winged helix/forkhead family of transcription factors are believed to play a role in cell-specific gene expression. A cDNA encoding a member of this family of proteins, termed hepatocyte nuclear factor/forkhead homologue 4 (HFH-4), has been isolated from rat lung and rat testis cDNA libraries. This cDNA contains an open reading frame of 421 amino acids with a conserved DNA binding domain and several potential transactivating regions. During murine lung development, a single species of HFH-4-specific transcript (2.4 kb long) is first detected precisely at the start of the late pseudoglandular stage (embryonic day 14.5) and, by in situ hybridization, is specifically localized to the proximal pulmonary epithelium. The unique temporal and spatial pattern of HFH-4 gene expression in the developing lung defines this protein as a marker for the initiation of bronchial epithelial cell differentiation and suggests that it may play an important role in cell fate determination during lung development. In addition to expression in the pulmonary epithelium, RNA blot analysis reveals 2.4-kb HFH-4 transcripts in the testis and oviduct. By using mice with genetic defects in spermatogenesis, HFH-4 expression in the testis is found to be associated with the appearance of haploid germ cells and in situ hybridization studies indicate that HFH-4 expression is confined to stages I-VII of spermatogenesis. This pattern of HFH-4 gene expression during the early stages of differentiation of haploid germ cells suggests that HFH-4 may play a role in regulating stage-specific gene expression and cell-fate determination during lung development and in spermatogenesis.

Land use practices near tributary rivers and their influence on duckweed (Lemna obscura) bloom in the southern part of Lake Maracaibo, Venezuela: Sustainable solutions to address the issue

This study examined the relationship between land-use practices near tributary rivers in South Lake Maracaibo and the appearance of duckweed (Lemna obscura) in the lake. Four rivers were studied: The Mucujepe, Capaz, Guamo and Frio. Eight factors were assessed: rivers, sediments, erosion, soils, fertilizers, water quality, land use activities and vegetation corridors. Satellite images, official cartography, field visits and observations, water samples and personal communication with organizations involved were held to get an accurate and current assessment of the conditions. The study revealed the land-use practices surrounding the Pan-American Zone Rivers contribute to the duckweed blooming in Lake Maracaibo.

Minority Coaches in the NFL: An Examination of Hiring Patterns as a Basis for Recommendations for Improved Employment Practices

Hiring minority coaches is a serious concern in the National Football League (NFL). The NFL's hiring practices are inconsistent, specifically for minority candidates. The author investigates why NFL teams underutilize minority coaches with research from Central Florida University and the University of Pennsylvania. Research findings suggest that minority hires positively affect the NFL, yet the hiring process remains weak. Case study examples show the poor decision-making trends of NFL personnel, implying that although minority coaches' success is better than non-minorities, the negative perception of minorities, as aspiring head coaches and leaders, is a barrier. As a result, the NFL has a unique opportunity to improve its hiring process by aligning its approach to hiring within the guidelines of federal law.

Looking inside for good practice in Deaf bilingual education: a participatory SWOT analysis

Presentation to the Disability Studies Conference, Lancaster University, September 7-9, 2010.

Assessment of Competences in the Physical Chemistry Area: Use of the Department Teaching Portfolio

Competences have become a standard learning outcome in present university education within the European Higher Education Area (EHEA). In this regard, updated tools for their assessment have turned out essential in this new teaching-learning paradigm. Among them, one of the most promising tools is the “learner´s portfolio”, which is based on the gathering and evaluation of a range of evidences from the student, which provides a wider and more realistic view of his/her competence acquisition. Its appropriate use as a formative (continuous) assessment instrument allows a deeper appraisal of student´s learning, provided it does not end up as another summative (final) evaluation tool. In this contribution we propose the use of the portfolio as a unifying assessment tool within a university department (Physical Chemistry), exemplifying how the portfolio could yield both personalized student reports and averaged area reports on competence acquisition. A proposed stepwise protocol is given to organize the individual competence reports and estimate the global competence level following a bottom-up approach (i.e. ranging from the class group, subject, grade, and academic course).

The regulation of professional advertising practices in Spain, 1988–2013

From the perspective of the sociology of professions, every professional activity should have its own clearly circumscribed and regulated sphere of action. Such an articulation facilitates the regulation of the production of a given profession as well as the way in which it is practiced. The purpose of the research reported here was to provide a comprehensive review and evaluation of the regulatory framework governing the advertising sector in Spain. To this end, the authors analysed external regulatory legislation and self-regulatory codes extracted from the data base of the Asociación para la Autoregulación de la Comunicación Comercial (Autocontrol) that had been enacted or adopted between 1988, the year that Law 11/1998 on General Telecommunications entered into force, and 2003 as well as other relevant documents retrieved from the Boletin Oficial del Estado (BOE) pertaining to the same period. Findings indicate that although there has been a groundswell of legislation governing advertising practices in Spain since 1988, especially at the regional level, lawmakers have focused on the content of advertising messages and shown very little interest in regulating the professions of advertising and public relations. Furthermore, Spanish legislation enacted in 2003 and EU policies appear to have encouraged the adoption of voluntary codes of ethics. Sectors traditionally subject to mandatory advertising regulation, either due to the vulnerability of their target audiences or the potential impact of their commercial messages on public health or the environment, are more likely to develop self-regulatory codes of conduct than others