Thesis advisor: Rebekah L. Coley / Children moving from early education programs into elementary schools face a critical transition, making it important for both systems to coordinate to better serve our youngest children. Yet, there is limited research on coordination around the transition to school. The objectives of this dissertation were to: 1) describe the coordination efforts used by Head Start programs to smooth children’s transitions to kindergarten, 2) examine the association between coordination and children’s outcomes in kindergarten, 3) test whether there is an interaction between Head Start coordination efforts and elementary school-based transition practices, 4) test interactions between coordination and child/family characteristics, and 5) understand the benefits and challenges to coordinating across systems. This study included two phases. Phase I examined coordination efforts between Head Start programs and elementary schools in a nationally representative sample of Head Start children (N=2,019). Findings suggest that Head Start programs are engaging in a variety of activities to coordinate with elementary schools. Results of regression analyses found that coordination was positively related to children’s language and mathematics skills in kindergarten for children enrolled in elementary schools engaging in limited activities to support the transition to school. Phase II involved interviews with sixteen Head Start directors. Results showed multiple ways they coordinate with elementary schools to share information about individual children and general program practices, as well as the ways they serve as a bridge between families and elementary schools. Findings suggest that coordination may benefit children through improved practices by Head Start and elementary schools, as well as increases in parental readiness and involvement.Overall this study shows that Head Start programs are engaging in multiple activities to coordinate with elementary schools. Although direct relationships between coordination practices and child outcomes were limited, interviews with Head Start directors pointed to indirect pathways by which coordination efforts may benefit children. These findings suggest the importance of coordination practices, and stress the need for additional research to explore these pathways. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Lynch School of Education. / Discipline: Counseling, Developmental and Educational Psychology.

Thesis advisor: Mariela Páez / Across preschool classrooms in the United States, free play comprises the largest percentage of children’s daily activity time (Chien et al., 2010; Fuligini et al., 2012). During free play, preschoolers may frequently engage in sociodramatic play (SDP), or pretend play where groups of children take on assigned roles with implicit rules (Smilansky & Shefatya, 1990). Research has demonstrated the academic and social benefits of SDP engagement (e.g., Diamond et al., 2007); however, much of this work has addressed SDP in curricular and intervention contexts, in which teachers play a large role in facilitating the play. Fewer studies have explored SDP in free play contexts with minimal teacher scaffolding, and even fewer have studied this play in classrooms comprised of cognitively, culturally, and linguistically diverse students, such as those participating in Head Start programs. This study investigated individual and peer factors that relate to SDP occurring in the context of free play among children (n=50) in five diverse mixed-age Head Start classrooms. A mixed methods approach was used to examine relations between children’s individual characteristics and abilities, classroom peer networks, and SDP outcomes. Sources of data included: 1) naturalistic observations of children’s free play, 2) assessments and demographic surveys of individual children, and 3) sociometric and semi-structured interviews with child participants. Results from multiple regression and hierarchical cluster analyses were merged with case studies of children who engage in exemplary amounts of SDP to enhance the understanding of individual and peer factors related to sociodramatic play. Findings indicated that narrative skills, home language background, gender, membership in a cohesive peer subgroup, and teacher presence were related to high amounts of SDP engagement. Implications for future research and for preschool practitioners are discussed. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.

As perdas localizadas de carga são elementos frequentemente negligenciados em dimensionamento de sistemas de irrigação, afetando a uniformidade de aplicação de água. Algumas peças acessórias não possuem equações que estimem estas perdas de forma simples e eficiente. Este trabalho foi desenvolvido com o objetivo de ajustar uma equação que estime a perda localizada de carga na passagem lateral em conectores. Foram testados 11 modelos de conectores em 12 diferentes diâmetros de tubos formando 15 conjuntos de tubo/conector. Os conectores foram caracterizados quanto aos diâmetros internos e dimensões. A perda localizada de carga foi obtida por diferença entre perda de carga distribuída no tubo mais conector e perda de carga no tubo. Os parâmetros responsáveis pela perda localizada de carga foram organizados em termos adimensionais utilizando o teorema de Buckingham. Um modelo matemático foi desenvolvido e apresentou um coeficiente de determinação de 93,31%. Elementos como diâmetro interno do conector e do tubo, comprimento do conector, velocidade de escoamento da água, número de Reynolds e número de Froude influenciaram na perda localizada de carga nos conectores. O modelo foi comparado com os dados observados e apresentou um desempenho classificado como ótimo, podendo ser empregado no cálculo da perda localizada de carga na passagem lateral em conectores. / Local losses are often neglected in design of irrigation systems affecting the uniformity of water application. Some accessories have no simple and efficient equations to estimate these losses. The main objective of this work was to develop an equation to estimate the local head loss in the lateral passage connectors. 11 models of connectors in 12 different diameters of pipes were tested forming 15 groups of pipe/connector. The connectors were characterized by its internal diameters and dimensions. The local head loss was determined by subtracting the head loss on the connector and pipe from the head loss on the pipe. The parameters affecting the local head loss were defined as dimensionless terms using Buckingham\'s theorem. A mathematical model was developed and presented a determination coefficient of 93.31%. Elements such as inner diameter of the connector and pipe length, connector, water flow velocity, Reynolds number and Froude number influenced the local head loss in the connectors. The model was compared with the observed data and presented a performance classified as excellent and can be used in calculating of the local head loss in the lateral passage connectors.

Introdução: O câncer é um processo de crescimento e disseminação celular descontrolado que pode acontecer em qualquer lugar do corpo, produzindo alterações fisiológicas e emocionais. Existem vários fatores de risco desta doença como o consumo de álcool, cigarro, alguns hábitos de alimentação, exposição crônica a fatores de risco devido a profissão e até alguns comportamentos sexuais. O tratamento depende do tipo e localização anatômica do câncer, podendo receber radioterapia, quimioterapia, extirpação cirúrgica, ou uma combinação das três terapias em fases avançadas da doença. Objetivo: Determinar a prevalência do câncer da cabeça e pescoço (CCP) dos pacientes atendidos no Serviço de Oncologia do Hospital de Especialidades \"Eugenio Espejo\", no período de 2002 a 2015. Métodos: O trabalho é um estudo descritivo, retrospectivo e transversal com a finalidade de determinar a prevalência do câncer da cabeça e pescoço nos pacientes atendidos no Serviço de Oncologia do Hospital de Especialidades \"Eugenio Espejo\" localizado em Quito - Equador, no período de 2002 a 2015. Os dados foram retirados das fichas clínicas hospitalares. O principal argumento apresentado que levou a está pesquisa é a ausência de dados deste porte no Equador. Foram estudadas variáveis relacionadas às condições demográficas, tipo e sítio anatômico, tipo de tratamento recebido e evolução. A informação foi coletada numa ficha de dados elaborada em Excel, com idade, sexo, ocupação, tipo, localização, diagnóstico e tipo de tratamento, tempo e evolução do tratamento. Os dados foram codificados e analisados no pacote estatístico STATA versão 14.0. Análise estatística descritiva foi realizada para as frequências absolutas e relativas. Os testes Qui-quadrado e de Poisson foram utilizados com nível significância de 95% e alfa de 0,05%. Resultados: Câncer de cabeça e pescoço ocorreu principalmente no sexo feminino com 50,7%, na faixa etária de 50-60 anos (20,3%), e com baixo nível de escolaridade (90,5%). O local de residência mais frequente foi Serra, com 76,7%. O pacientes apresentaram ocupações domésticas em 38,4% dos casos, a região anatômica mais prevalente foi a cavidade bucal com 36,4%, sendo que a localização mais afetada foi a língua (C01-C02). O tratamento que prevaleceu foi o tratamento cirúrgico em 38,9% dos casos. O tempo de tratamento variou entre 1 e 180 dias em 44,5%, e 31,8% finalizaram o tratamento. Não foi observada associação entre o câncer de cabeça e pescoço (CCP) e variáveis sociodemográficas ou clínicas, salvo o local de residência, para o qual se encontrou relação significativa em relação aos tipos de câncer. / Introduction: Cancer is a process of uncontrolled cell growth and dissemination that can occur anywhere in the body, producing physiological and emotional alterations. There are several etiological factors of this disease such as alcohol consumption, smoking, eating habits, chronic exposure to risk factors due to profession and even some sexual behaviors. Treatment depends on the type and anatomical location of the cancer, patients may receive radiation therapy, chemotherapy, surgical excision, or a combination of these therapies in advanced stages of the disease. Objective: To determine the prevalence of head and neck cancer (H&NC) among patients treated at the Oncology Service of \"Eugenio Espejo\" Hospital Quito-Equador, from 2002 to 2015. Methods: This is a descriptive, retrospective and cross-sectional study. Data were obtained from the medical records of patients treated with a diagnosis of CCP, at the Oncology Service of the Hospital \"Eugenio Espejo\". The variables to be considered were demographic data, etiological factors, type of cancer, anatomical location, treatment received and treatment evolution time. The information was collected in a datasheet elaborated in Excel, variables such as age, sex, occupation, etiological factors, stage, type, location, diagnosis and type of treatment, time and treatment evolution were retrieved. The data were coded and analyzed in the statistical package STATA version 14.0. An analysis of descriptive statistics was performed for absolute and relative frequencies. The Chi-square and Poisson tests were used with a confidence level of 95% and assumed alpha of 0.05%. Results: In those patients with H&NC, women predominated with 50.7%, the prevalent age group was 50-60 years with 20.3%, low level of education prevailed with 90.5%, the place of residence (Highlands) with 76.7%, domestic occupations were observed in 38.4% of the cases, the most prevalent anatomical region was the oral cavity with 36.4%, and the most affected location being the tongue (C01-C02), the treatment that prevailed was is the surgical treatment with 38.9% of the cases, treatment time ranged from 1 to 180 days with 44.55% and 31.8% of patients concluded the treatment. There has been no association between H&NC and socio-demographic or clinical variables, except the place of residence, for which a significant relation was found in relation to the types of cancer.

Os microRNAs (miRNAs, miRs) são pequenos RNAs não codificadores presentes em diferentes organismos. Esses RNAs regulam a tradução de genes alvos por meio de ligação seqüência-específica a RNAs mensageiros (mRNAs). Dependendo do grau de complementaridade, podem inibir a tradução e/ou induzir a degradação desses mRNAs. No presente estudo, foi investigado por PCR em tempo real o padrão de expressão de quatro microRNAs (miR-21, -205, -342 e let-7a ) em quatro linhagens celulares derivadas de tumores da cavidade oral e da faringe (FaDu, Hep-2, SCC9 e UM-SCC-38), em queratinócitos orais normais e em amostras de tumor e margens cirúrgicas pareadas de 34 pacientes com carcinomas epidermóides de cabeça e pescoço (CECP). Foi também investigada a correlação da expressão dos MiRs de interesse com as características clinicopatológicas de pacientes com CECP. Nas linhagens celulares, os níveis dos miRs foram similares ou mais baixos que os de queratinócitos normais, ou os miRs não se expressaram. Somente o miR-342 mostrou níveis elevados na linhagem FaDu. Em células Hep-2 tratadas com estradiol, a expressão de miR-let-7a mostrou-se reduzida. Em tumores primários, níveis baixos de miR-let-7a foram observados em carcinomas de soalho de boca e laringe. A expressão de miR-21, -205 e -342 mostrou grande variabilidade entre as amostras e foi reduzida em um dos sítios anatômicos. Não foi observada correlação entre a expressão dos miRs e as características clinicopatológicas dos pacientes com CECP. A análise de três genes alvo candidatos (LYZ, MGLL e SPRR3) mostrou, em carcinomas de soalho de boca e laringe, associação positiva entre a expressão de miR-let-7a e de seu alvo predito MGLL, uma lipase que pode favorecer o fenótipo maligno aumentando os níveis de ácidos graxos livres e sinais lipídicos oncogênicos. O significado dessa associação não pode ser deduzida dos experimentos realizados pelo presente trabalho. / MicroRNAs (miRNAs, miRs) are small, non-coding RNAs present in different organisms. They regulate the translation of target genes through sequence specific binding to mRNA. Depending on the degree of sequence complimentary, they can inhibit translation and/or degradation of target mRNAs In the present study, we used real time PCR to investigate the expression pattern of four microRNAs (miR-21, -205, -342 e let-7a ) in four cell lines derived from tumors of oral cavity and pharinx (FaDu, Hep-2, SCC9 e UM-SCC-38), in normal oral keratinocytes and in matched tumor / surgical margin samples from 34 patients with head and neck squamous cell carcinomas (HNSCC). We also aimed to correlate the miR expression with the clinicopathological features in HNSCC. In cell lines, the miR levels were similar or lower than those in normal keratinocytes, or even absent. Only miR-342 showed high levels in FaDu cell line. In Hep-2 cells treated with estradiol, miR-let-7a expression was reduced. In primary tumors, low miR-let-7a levels were observed in floor of the mouth and larynx carcinomas. The expression of miR-21, -205 and -342 showed high variability between samples and was reduced in one anatomical site. No correlation was observed between miR expression and clinopathological features of head and neck cancer patients. The analysis of three potential target genes (LYZ, MGLL e SPRR3) showed, in floor of the mouth and larynx carcinomas, a positive correlation between the expression of miR-let-7a and its predicted target gene MGLL, a lipase that may support the malignant phenotype by increasing levels of free fatty acids and oncogenic lipid signals. The meaning of such association was not clear from our data.

by Hon-wing Tsui. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves 151-203.

by Shik Yuen Lo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 102-124). / Abstract / List of Illustrations / List of Tables / Acknowledgements / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Literature Review / Chapter 2.1 --- Anatomy of the Human Nasopharynx --- p.4 / Chapter 2.2 --- Histology of the Human Nasopharynx --- p.6 / Chapter 2.3 --- Intra-epithelial Lesions of the Nasopharyngeal Epithelium --- p.10 / Chapter A. --- Hyperplasia / Chapter B. --- Metaplasia / Chapter C. --- Koilocytes / Chapter D. --- Nasopharyngeal intra-epithelial neoplasia / Chapter 2.4 --- Nasopharyngeal Carcinoma --- p.19 / Chapter A. --- Histopathological classification of NPG / Chapter B. --- Epidemiology / Chapter C. --- Etiological factors / Chapter 2.5 --- Epstein-Barr Virus and Nasopharyngeal Carcinoma --- p.27 / Chapter A. --- Serological / Chapter B. --- EBV genome in NPC / Chapter C. --- EBV encoded latent gene products / Chapter 2.6 --- Cancer Genes in Nasopharyngeal Carcinoma --- p.28 / Chapter A. --- "Tumours suppressor Gene, p53" / Chapter B. --- "Oncogenes, c-myc, ras and bcl-2" / Chapter 2.7 --- Immunohistochemical methods --- p.33 / Chapter A. --- Avidin-Biotin Complex method (ABC) / Chapter B. --- Alkaline phosphotase Anti-alkaline phosphotase method (APAAP) / Chapter C. --- Unmasking of antigens / Chapter 2.8 --- Techniques in ISH --- p.40 / Chapter 3. --- Material and Methods --- p.42 / Chapter 3.1 --- Tissue Samples --- p.42 / Chapter A. --- "Samples for ras, c-myc and p53 studies" / Chapter B. --- Samples for LMP-1 study / Chapter C. --- Samples for bcl-2 study / Chapter D. --- Samples for EBER-RNAs study / Chapter 3.2 --- Monoclonal Antibodies --- p.47 / Chapter 3.3 --- Tissue Processing --- p.49 / Chapter A. --- Tissue processing for formalin fixed tissue / Chapter B. --- Tissue processing for frozen section / Chapter 3.4 --- IHC Techniques --- p.50 / Chapter A. --- Pretreatment of Laboratory Wares / Chapter B. --- Determination of optimum dilution and incubation time for p53antibody / Chapter C. --- Determination of optimum dilution and incubation time for bcl-2 and LMP-1 antibodies / Chapter D. --- Determination of optimum dilution and incubation time for c-myc and ras / Chapter E. --- "Detection of p53, c-myc and ras by ABC method" / Chapter F. --- Detection of bcl-2 and LMP-1 by APAAP method / Chapter 3.6 --- ISH --- p.57 / Chapter A. --- Pretreatment of laboratory wares / Chapter B. --- FITC conjugated EBER oligonucleotide probe / Chapter C. --- Determination of PK dilution for paraffin section / Chapter D. --- Determination of PK dilution for frozen section / Chapter E. --- Determination of the choice of fixative for frozen section / Chapter F. --- Detection of EBER-RNAs by ISH method / Chapter 3.7 --- Statistical analysis --- p.62 / Chapter A. --- p53 / Chapter B. --- c-myc and ras / Chapter 4. --- Results --- p.63 / Chapter A. --- ras / Chapter B. --- c-myc / Chapter C. --- p53 / Chapter D. --- LMP-1 / Chapter E. --- Bcl-2 / Chapter F. --- EBER-RNAs / Chapter 5. --- Discussion --- p.86 / Chapter 6. --- Conclusion and Summary --- p.97 / Appendix --- p.99 / Reference --- p.102

Design This is a cross-sectional study involving quantitative measures and qualitative interviews. Participants Sixteen brain injured men and four brain injured women participated. Eighteen of these had a close relative who also took part. Measures In addition to being interviewed, brain injured participants completed questionnaires on mood symptoms and fatigue, and a speed of information processing task. Relatives of brain injured people were interviewed and completed the symptom checklist. Correlational analysis was applied to the quantitative measures and- qualitative analysis was informed by the grounded theory approach. Results Quantitative measures suggest significant association of subjective perception of fatigue severity with mood and brain injury related symptoms. Relatives' objective perceptions of brain injured relatives' symptoms correlated significantly with subjective views. Subjective perception of fatigue did not correlate significantly with severity of brain injury or information processing speed. Qualitative analysis identified fatigue as a major problem for some people. Descriptions noting the impact of fatigue following injury included increased slowness, decreased energy, and lack of control. Fatigue was commonly considered to be more mental than physical, and was often linked with short temper. Conclusions Findings suggest that fatigue was related less to severity of injury than to psychological and emotional factors. The multidimensional nature of fatigue was confirmed. Links were made with low-mood, anxiety, lack of motivation, boredom, and having to cope with 'normal life' following brain injury. The possibility that 'fatigue' is an umbrella term used by some to describe a range of symptoms following brain injury was considered.

La crête neurale crâniale (CNC) est une structure transitoire et pluripotente de l’embryon des Vertébrés qui génère la totalité du squelette de la face et de la voûte crânienne et fournit les méninges et une vascularisation fonctionnelle au cerveau antérieur. Précocement, la CNC contrôle également la croissance du cerveau. Pour identifier les mécanismes par lesquels la CNC exerce son rôle trophique sur le cerveau, nous nous sommes intéressés à l’expression du gène Smad1, qui transduit divers voies de signalisation, et est massivement exprimé par les cellules de la CNC juste avant leur migration. L’inactivation de Smad1 par l'interférence ARN dans les CCN conduit à une microcéphalie sévère et une holoprosencéphalie partielle, qui résulte de la perte de l’expression de Fgf8 et Foxg1. Les expériences de sauvetage montrent que les cellules de la CNC régulent positivement Foxg1 indépendamment de Fgf8. De plus, nous montrons que la perte de fonction de Foxg1 dans le télencéphale affecte le développement du thalamus et du toit optique en dérégulant l’expression de Otx2 et de Foxa2 à leur niveau. Nous avons identifié les molécules médiatrices produites par les cellules de la CNC nécessaire au contrôle de l’expression de Foxg1. Nous montrons que les antagonsites de Bmp and Wnt, Noggin, Gremlin et Dkk1 sont indispensable pour initier la spécification du télencéphale. De plus, la régionalisation moléculaire des territoires télencephalique et di/mésencéphalique, requiert l’activité conjointe de Sfrp1 et Sfrp2, d’une part, et de Cerberus, d’autre part. L’ensemble des données acquises au cours de ces travaux documente les mécanismes moléculaires par lesquels la CNC participe de façon essentielle à la régionalisation moléculaire du cerveau des Vertébrés. / The cranial NC (CNC) is a transient structure of the vertebrate embryo, which is essential for brain ontogenesis and provides the developing brain with a skeletal and meningeal protection and functional vasculature. Early in development, CNC cells also control morphogenetic activities of brain organizers and stimulate the growth of prosencephalic alar plate. To understand how CNC conveys its trophic effect on the telencephalon, we have silenced the gene encoding for Smad1, a transcription factor expressed in the CNC cells, which transduces diverse morphogenetic pathways. Smad1 silencing results in microcephaly and partial holoprosencephaly, which early coincide with the loss of Fgf8 and Foxg1 in the telencephalon. Rescue experiments show that CNC cells can positively regulate Foxg1 expression independently of Fgf8 activity in the prosencephalic organizer. Furthermore, the depletion of Foxg1 activity in the telencephalon alters Otx2 and Foxa2 expression in the thalamus and tectum. We have identified the mediators produced by the CNC to control Foxg1 activity and showed that Bmp and Wnt antagonists, Noggin, Gremlin and Dkk1 initiate the specification of the telencephalon. Additionally, the molecular patterning of the telencephalic and di/mesencephalic compartments requires the activity of Sfrp1 and Sfrp2, and Cerberus, respectively. Altogether, we show that CNC cells controls brain patterning by regulating Foxg1 expression through a network of morphogen modulators controlled by Smad1 activity. / A crista neural cranial (CNC) é uma estrutura transiente em embriões de vertebrado, que possui um papel crucial no desenvolvimento da cabeça. A CNC é uma importante fonte de derivados mesenquimais. Recentes descobertas mostraram que as células da CNC possuem uma atividade trófica no desenvolvimento do tubo neural anterior, estimulando e organizando o desenvolvimento prosencefálico em oposição à sinalização Bmp presente nos tecidos adjacentes. Com o objetivo de entender como as células da CNC controlam a atividade de morfógenos durante o desenvolvimento do cérebro. Nós focamos nossos estudos no fator de transcrição Smad1, expresso pelas células da CNC, que controla a transcrição de Noggin. Noggin é um antagonista de Bmp que por sua vez controla a atividade de sua via de sinalização. Além disso, Smad1 interage com outras vias de sinalização com Fgf8 e Wnt. Para testar o papel de Smad1 nas células da CNC, nós eletroporamos o RNA dupla fita de Smad1 (dsSmad1) nas células da CNC em embriões de galinha no estágio de 4 somitos com a finalidade de bloquear sua tradução. Estes espécimes foram analisados em estágio mais avançados do desenvolvimento embrionário. A perda de função de Smad1 compromete o desenvolvimento das vesículas cefálicas, nos estágios de 26 somitos, E4, E6 e E8. Em cortes histológicos em E8, observou-se o aumento do volume ventral do cérebro destes embriões. Com o objetivo de entender como Smad1 controla o desenvolvimento das vesículas cefálicas, embriões no estágio de 26ss foram analisado por hibridização in situ. Nós observamos em embriões dsSmad1 a diminuição da expressão de Fgf8 na borda neural anterior e a completa ausência de expressão de Foxg1 no neuroectoderma prosencéfalico. A falta de Smad1, também gera a diminuição da expressão de Otx2 nos limites ventrais e laterais do telencéfalo, diencéfalo e mesencéfalo. Em contrapartida, nestes embriões observa-se o aumento da zona de expressão de Foxa2 na porção ventral do diencéfalo e mesencéfalo. O bloqueio de Smad1 também acarreta no aumento dos níveis de Dkk1, que é um importante inibidor da via de sinalização Wnt. Com o intuito de entender o mecanismo sobre o controle de Smad1, nós aumentamos os níveis de transcritos nas células da CNC de Dkk1. Como resultado deste aumento, observamos as mesmas modificações nos níveis dos transcritos de Fgf8, Foxg1, Otx2 e Foxa2. Interessantemente os efeitos do excesso de Dkk1 podem ser revertidos com a co-eletroporação do Smad1 constitutivamente fosforilada. Nós também analisamos a expressão de Foxg1 e Otx2 em embriões privados de Cubilin nas células da CNC. Estes embriões apresentam o mesmo padrão de expressão encontrados nos embriões dsSmad1. Interessantemente os nocautes para Cubilin apresentam diminuição da fosforilação de Smad1. Nossos resultados mostram que a presença de Smad1 nas células da CNC é extremamente importante para padronização e desenvolvimento do cérebro. Smad1 nas células da CNC funciona como um regulador da via de Bmp, através do controle transcricional de Noggin impedindo que o excesso de Bmp chegue até o tubo neural. Sendo assim, Smad1 controla o excesso de Bmp permitindo a indução e o desenvolvimento da região anterior por Fgf8.

This study focuses on the career paths and career projections of teacher professionals who are at a stage in their professional roles where they have not embarked upon senior leadership positions in the schools in which they work. Often research has focused retrospectively on the career paths of those already in leadership posts rather than those who are expected to be aspiring to leadership, have discounted this option or are yet to make a decision. Increasing numbers of re-advertisements for headship posts indicates a lack of willing or suitable candidates applying. Changes to school staffing structures and the role of headteachers in recent years have resulted in greater responsibilities including financial matters and the maintenance of premises. Government policies in favour of schools becoming academies has removed local authority support and placed increased pressure on individual school leaders. These factors coupled with the external inspection system and the media focus on so called failing schools has led to the role of head becoming unattractive to many and this study aims to collect the views of a sample of teachers regarding this role. Six schools of similar type were selected from within one local authority and a survey was utilised in order to collect data. This was initially in the form of a questionnaire completed by seventy nine teachers from which twelve participants took part in two interviews each. Teachers were subsequently organised into one of four career categories; 'careerist', 'serendipity', 'active choice' and 'stuck'. Analysis of the data indicates that many teacher professionals do not plan to become senior leaders or heads. This is in agreement with many serving heads who in existing research claim not to have planned their routes to headship. However, the majority of the sample in this study have already ruled out the role of head, finding the pressures and perceived stress of the role unappealing and not wishing to lose their identity as classroom teachers. The underrepresentation of women in headteacher posts does not look likely to be addressed in the near future as females in the study are more likely to feel unable to pursue leadership roles often due to family commitments. A larger proportion of females have made the choice not to pursue leadership roles than males, even when those females did not necessarily have the pressures of home responsibilities. For many females future decisions regarding starting families and seeking promotions produced dilemmas that men did not appear to have to confront. These factors look likely to lead to continued headteacher shortages in the short term with no real incentives to encourage females to pursue such posts now or in the future.