No description available.

All complex organisms possess a nervous system which they use to monitor environmental and internal stimuli. In higher vertebrates, the nervous system is comprised of billions of cells which form highly plastic neural networks from their synapses. These large neural circuits modulate complex behaviors. The nematode roundworm Caenorhabditis elegans uses a small but highly-interconnected nervous system to carry out complex behaviors. The nervous system of C. elegans is a tractable model to determine the effects of changes on a nervous system at the systemic, cellular, genetic, and molecular levels. The C. elegans male’s nervous system detects environmental conditions, mating cues, attractants, repellents, and the location and composition of possible food sources and integrates these inputs to compute the decision of whether or not to mate. Mating behavior in the C. elegans male is regulated at a number of steps by cholinergic signaling from various sensory and sensory-motor neurons, but a comprehensive model of how cholinergic signaling controls this circuit has not yet been elucidated. Previous studies have thoroughly dissected the cellular structure, neural connectivity, and signaling pathways of the male’s peripheral circuits located in the genital regions of the animal’s tail. However, no studies have been conducted to determine what role the cephalic cholinergic neurons have in regulating mating behavior. I hypothesized that cephalic cholinergic neurons exert regulatory control over the male-specific mating circuit. I inserted the transmembrane light-activated ion pore Channelrhodopsin-2 fused to YFP and expressed from the Punc-17small promoter into these neurons and selectively stimulated them using high-intensity blue light. Stimulation induced mating-like behaviors in the male tail consistent with behaviors seen during copulation with a hermaphrodite. Using behavioral assays, I demonstrated that these behaviors were male-specific and only occurred after direct stimulation in the absence of a hermaphrodite. Incidence of mating-like behaviors increased significantly as the worm aged, and the mating circuit retained a memory of the stimulus, indicated by the latency between stimulation and onset of mating-like behaviors. Brief food deprivation, which normally downregulates excitability of the mating circuit via UNC-103 ERG-like K+ channels, caused an unexpected increase in the number of blue light-stimulated behaviors displayed. Pharmacological assays using acetylcholine (ACh) agonists showed that stimulation of the cephalic cholinergic neurons increased propensity for spicule protraction in the presence of an ACh agonist, and partially restored the decline in spicule protraction associated with temporary food deprivation. I sought to identify the cephalic cholinergic neuron or neurons responsible for regulating mating-like behavior in the tail circuits. I looked for a reduction in mating-like behaviors after stimulation after removal of a cephalic cholinergic neuron pair via laser micro-ablation. Two cholinergic and chemosensory neuron pairs in the inner labial sensilla (IL2L/R and IL2VL/R) appear to generate and/or relay the signal that induces mating-like behaviors in the tail. I hypothesize that these neurons sense environmental cues before the male contacts a mate, and modulate lasting motivational changes within the male mating circuit.

No description available.

Thesis (MMed)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: AIM: Review outcome of pregnancies following successful external cephalic version (ECV) for breech presentation at term, particularly the caesarian section (CS) rate. ECV is a safe procedure with a minimal cost implication that can reduce non-cephalic presentation at onset of labour at term. The outcome of pregnancies following successful ECV is certainly of interest. A meta analysis of studies done between 1997 and 2004, found that pregnancies after successful ECV at term were not the same as those with spontaneous cephalic presentations and was associated with a CS rate twice that in pregnancies with spontaneous cephalic presentations. The conclusion was that pregnancies after successful ECV should not be considered the same as normal pregnancies. In a matched retrospective analysis of CS risk after successful ECV, done in the USA, it was concluded that CS delivery and operative vaginal delivery rates following successful ECV, were not increased. To date there are no such studies in South Africa. METHODOLGY: A retrospective descriptive study was done to audit all successful ECV’s done at the Fetal Evaluation Clinic (FEC) of Tygerberg Academic Hospital. The electronic data from the FEC was searched for successful ECV patients. The facilities where these patients delivered were identified. The outcome of the pregnancies was determined from patient files and/or the labor registers. The relevant information of each patient was captured. All file reviews and data capturing was done by the principal investigator. RESULTS: A total of 78 patients were included in the study. The median age was 28.7 years with a range from 17 to 40 years, the median parity 1 and the range 0 to 6 and the median body mass index 27.2 and the range 18.2 to 45.0. The method of determining gestational age is known in 71 (91%) patients of whom 37 (52%) had an early ultrasound examination. The median gestational age at ECV was 37 weeks with the inter quartile range 36 to 38 weeks. The median ECV to delivery time was 2 weeks with the inter quartile range 1 to 4 weeks. Higher levels of care were required at time of delivery by 47 (60.3%) patients. Vaginal deliveries occurred in 49 patients and 29 (37.2%) had CS. The most common indications for CS were cephalo pelvic disproportion 8, fetal distress 6, reversion back to breech presentations 4 and other abnormal presentations 4 (2 face presentations and 2 transverse lies). The mean birth weight of the babies was 3360g and the range 2100 to 4655g. On comparing the groups that had vaginal deliveries and CS, only nulliparous patients had a significantly (p=0.02) higher risk for CS. CONCLUSIONS: Following successful ECV all patients need to be carefully followed up for possible reversion to breech presentation or transverse lie. Nulliparous and gravid 2 para 1 patients with a previous CS need to be delivered in hospitals with CS facilities. Further studies are required to assess whether successful ECV results in more face presentations. / AFRIKAANSE OPSOMMING: DOELWIT: Om die uitkoms van swangerskappe na suksesvolle eksterne kefaliese kerings (EKK) vir stuit presentasies op voltyd, spesifiek die keisersnit (KS) insidensie te bepaal. EKK is ‘n veilige prosedure wat teen minimale koste die nie-kefaliese presentasies op voltyd kan verminder. Die uitkoms van swangerskappe na suksesvolle EKK is van belang. ‘n Meta-analise van studies gedoen tussen 1997 en 2004 vind dat swangerskappe na suksesvolle EKK op voltyd nie dieselfde is vergeleke met spontane kefaliese presentasies nie en gepaard gaan met ‘n KS koers tweekeer hoër as dié met spontane kefaliese presentasies op voltyd. Die gevolgtrekking was dat swangerskappe na suksesvolle EKK nie as normale swangerskappe beskou moet word nie. In ‘n gepaarde retrospektiewe ontleding van die KS risiko wat in die VSA gedoen is, word gevind dat die KS en operatiewe vaginale verlossing koerse na suksesvolle EKK, nie verhoog is nie. Tot op hede is daar geen studies hieroor in Suid-Afrika gedoen nie. METODE: ’n Retrospektiewe beskrywende studie is gedoen om all suksesvolle EKK wat by die Fetale Evaluasie Kliniek (FEK) gedoen is te oudit. ‘n Elektroniese data soektog van suksesvolle EKK by die FEK is gedoen. Die instellings waar die pasiënte verlos is, is vasgestel. Die uitkoms van die swangerskappe is bepaal deur pasiënt lêers en/of die kraamregisters na te gaan. Die relevant inligting oor elke pasiënt is versamel. RESULTATE: ‘n Totaal van 78 pasiënte is by die studie ingesluit. Die mediane ouderdom was 28.7 jaar met ‘n reikwydte van 17 tot 40 jaar, die mediane pariteit was 1 met ‘n reikwydte van 0 tot 6 en die mediane liggaamsmassa indeks 27.2 met ‘n reikwydte van 18.2 tot 45.0. Die metode waavolgens swangerskapsduurte bepaal is, was bekend in 71 (91%) van pasiënte, waarvan 37 (52%) vroeë ultraklank ondersoeke gehad het. Die mediane swangerskapsduurte tydens die EKK was 37 weke met die interkwartiele interval 36 tot 38 weke. Die mediane EKK tot verlossing tydsverloop was 2 weke met die interkwartiele interval 1 tot 4 weke. Hoër vlakke van sorg was nodig ten tye van die verlossing by 47 (60.3%) van pasiënte. Van die pasiënte het 49 vaginale verlossings en 29 (37.2%) KS gehad. Die mees algemene indikasies vir KS was skedel-bekken disproporsie 8, fetale nood 6, terugkeer na stuitpresentasie 4 en abnormale presentasies 4 (2 aangesigsliggings en 2 transversliggings). Die gemiddelde geboorte gewig van die babas was 3360g en die reikwydte 2100 tot 4655g. Wanneer die groep wat vaginale verlossing en KS gehad het vergelyk word, het slegs nullipareuse pasiënte ‘n betekenisvolle (p=0.02) hoër risiko vir KS gehad. GEVOLTREKKING: Na suksesvolle EKK moet alle pasiënte noukeurig opgevolg word vir terugkeer na ‘n stuit presentasie of transversligging. Nullipareuse en gravida 2 para 1 pasiënte met ‘n vorige KS moet in hospitale met KS fasiliteite verlos word. Verdere studies is nodig om te bepaal of suksesvolle EKK meer aangesig presentasies tot gevolg het.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / A fase cefálica de secreção de insulina (FCSI) ocorre dentro da fase cefálica da digestão, em aproximadamente dez minutos entre a estimulação oro-sensorial pelo alimento e o início da absorção deste e determina um incremento rápido dos níveis basais de insulina. A FCSI parece ser importante para a tolerância normal à glicose. A hipótese deste estudo é de que a insulina secretada na fase cefálica da digestão teria ações direcionadas para o tecido microvascular, com conseqüente recrutamento capilar. Estudos recentes com indivíduos sadios têm mostrado a associação entre função microvascular e componentes dietéticos. Padrões alimentares saudáveis e intervenções nutricionais com alimentos específicos representam estratégias preventivas e terapêuticas não-farmacológicas para redução da inflamação e do risco metabólico e cardiovascular associados. O estudo de consumo alimentar inserido nesta pesquisa objetivou identificar associações entre componentes dietéticos e a função microvascular em indivíduos saudáveis. Após avaliação clínica e laboratorial, 39 voluntários saudáveis foram submetidos a dois exames de videocapilaroscopia do leito ungueal, com um intervalo de dez minutos entre os mesmos. Neste intervalo, conforme randomização, uma refeição com ótima apresentação e aroma foi apresentada (estímulo sensorial) ou não (controle). Coletas sangüíneas foram realizadas aos 3, 9 e 15 minutos após a apresentação do estimulo, para avaliação dos níveis de insulina e polipeptídeo pancreático (PP), marcadores bioquímicos da fase cefálica da digestão. Durante todo o exame medidas de fluxo e vasomotricidade foram realizadas pela técnica de laser-Doppler fluxometria. Após o exame, foi realizada iontoforese transdérmica de insulina. Todos os participantes responderam a um questionário de freqüência alimentar (QFA), relativo ao hábito de consumo dietético dos últimos 12 meses. O estudo da resposta microvascular à fase cefálica comparou as diferenças de densidade capilar funcional e fluxo capilar nos grupos experimental e controle, antes e após o estímulo sensorial, e sua correlação com a variação de insulina e PP. O estudo de consumo alimentar avaliou correlações entre componentes dietéticos e recrutamento capilar no exame basal (antes do estímulo) em toda amostra. Após o intervalo, o grupo que recebeu o estímulo sensorial teve sua densidade capilar funcional (DCF) aumentada. A variação de insulina não diferiu entre os grupos e a de PP foi maior no grupo estimulado, sendo também correlacionada positivamente como aumento na DCF. A velocidade máxima de perfusão pósisquemia também aumentou no grupo estimulado, enquanto o tempo para alcançar esta velocidade máxima diminuiu. O estudo do consumo alimentar revelou associações positivas entre o consumo de cálcio, selênio e laticínios e recrutamento capilar na amostra total. Em conclusão, o consumo alimentar de cálcio, selênio e laticínios foi associado com maior recrutamento capilar em indivíduos sadios. Nestes indivíduos a microcirculação cutânea respondeu ao estímulo da fase cefálica da digestão com recrutamento capilar e aumento de fluxo sanguíneo microvascular. / The cephalic phase of insulin secretion (CPIS) occurs within the cephalic phase of digestion, in approximately ten minutes between the oral-sensorial stimulation elicited by the food to be consumed and the beginning of its absorption. It determines a rapid increase in insulin levels. The CPIS is believed to be important for normal glucose tolerance. The hypothesis of this study is that insulin secreted during cephalic phase would also have actions targeting microvascular tissue, with resulting capillary recruitment. Recent studies with healthy subjects have shown an association between microvascular function and dietary factors. Healthy eating patterns and nutritional interventions with specific food items represent non-pharmacological preventive and therapeutic strategies for reducing inflammation and cardio-metabolic associated risk factors. The study of food intake included in this research aimed to identify associations between dietary intake and microvascular function in healthy subjects. After clinical and laboratorial assessment, 39 healthy men underwent two nailfold videocapillaroscopies, with an interval of 10 minutes between them. In this interval, according to randomization, they were subjected to a great-looking breakfast tray (CPIS group) or to nothing (control group). Blood samples were drawn at 3, 9 and 15 minutes after the stimulus presentation to assess insulin and pancreatic polypeptide (PP) levels, which are markers of cephalic phae of digestion. Throughout the exam, microflow and vasomotion were measured by laser-Doppler flowmetry. After the exam insulin iontophoresis was performed. All participants answered a food-frequency questionnaire (FFQ) regarding their dietary intake in the last 12 months. The assessment of microvascular response to CPIS compared differences in functional capillary density (FCD) and microflow in the CPIS and control groups, pre- and post-stimulus and their correlations with changes in insulin and PP. The study of food intake attempted to identify correlations between dietary factors and functional capillary recruitment pre-stimulus in the total sample. After the interval, the CPIS group had significantly increased basal and peak FCD. Insulin variation was not different between groups. PP was significantly increased in the CPIS group and its variation was positively correlated with FCD increase. Resting red blood cell velocity (RBCV) and peak RBCV were also significantly increased and time taken to reach peak RBCV, decreased. The study of food intake revealed positive associations between calcium, selenium and dairy intakes and functional capillary recruitment in the total sample. In conclusion, skin microcirculation is activated during cephalic phase of digestion. Selenium, calcium and dairy intakes are positively associated with capillary recruitment in healthy men.

Submitted by SILVANA ROCHA DA SILVEIRA null (silvana.silveira@anhanguera.com) on 2017-11-29T13:04:22Z No. of bitstreams: 1 Análise do comportamento do centro de pressão (CoP) na posição ereta quieta em situação de aclive, declive e horizontal diante da movimentação cefálica..pdf: 2182243 bytes, checksum: fd39ef1b65f1cbb09db1e3c1d618854b (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2017-11-29T14:23:36Z (GMT) No. of bitstreams: 1 silveira_sr_dr_guara.pdf: 2182243 bytes, checksum: fd39ef1b65f1cbb09db1e3c1d618854b (MD5) / Made available in DSpace on 2017-11-29T14:23:36Z (GMT). No. of bitstreams: 1 silveira_sr_dr_guara.pdf: 2182243 bytes, checksum: fd39ef1b65f1cbb09db1e3c1d618854b (MD5) Previous issue date: 2017-09-29 / O controle postural é um requisito imprescindível para a execução das habilidades motoras durante as tarefas das atividades de vida diária, logo, há a necessidade constante de ajuste dos segmentos corporais para garantir a autonomia e independência da mobilidade humana, dentro da conjuntura da acessibilidade. Os ajustes posturais são resultantes da interação do sistema sensório–motor e da sua correlação com o meio ambiente, produzindo orientação e estabilidade postural esperada durante a execução das atividades diárias, sendo ela estática ou dinâmica. Deste modo, o objetivo do estudo foi analisar e comparar o comportamento do centro de pressão na posição ereta quieta em situação de aclive, declive e horizontal diante da movimentação cefálica, entre três grupos com faixas etárias diferentes. O estudo transversal foi composto de 28 indivíduos, de ambos os gêneros, divididos em três grupos por faixas etárias (20 a 29 anos, 30 a 59 anos e acima de 60 anos), de acordo com os critérios de inclusão. O instrumento de avaliação constituiu-se por uma plataforma de força acoplada numa rampa com 15° e em um platô horizontal. A coleta dos dados seguiu um protocolo pré-determinado, envolvendo a posição ereta quieta com olhos abertos (OA), em quatro condições cefálicas, em três situações: aclive, declive e horizontal. Os dados obtidos foram trabalhados por meio do programa Matlab® e para a análise estatística foi aplicado o programa Action Start, utilizando a análise descritiva dos dados e o Teste Anova: fator único, Teste-t: duas amostras em par para média e Teste-t: duas amostras presumindo variâncias diferentes. Os resultados do presente estudo apontaram que a oscilação do CoP na posição ereta quieta com olhos abertos, se alteram diante das condições em que o segmento cefálico encontra – se em movimento, independente das situações de aclive, declive e horizontal, principalmente nos grupos com faixa etária igual ou superior a 60 anos / Postural control is an essential requirement for the performance of motor skills during daily activities, so there is a constant need to adjust the body segments to ensure the autonomy and independence of human mobility, within the context of accessibility. Postural adjustments result from the interaction of the sensor - motor system and its correlation with the environment, producing orientation and postural stability expected during the execution of daily activities, being static or dynamic. Thus, the objective of the study was to analyze and compare the behavior of the pressure center in the standing upright position in slope, slope and horizontal situation in front of the head movement, between three groups with different age groups. The cross-sectional study consisted of 28 individuals of both genders, divided into three groups by age group (20 to 29 years, 30 to 59 years and above 60 years), according to the inclusion criteria. The evaluation instrument consisted of a force platform coupled on a ramp with 15 ° and a horizontal plateau. Data collection followed a predetermined protocol, involving the standing upright position with open eyes (OA), in four cephalic conditions, in three situations - slope, slope and horizontal. The data obtained were worked through the Matlab® program and for the statistical analysis the Action program was applied using descriptive data analysis and the Anova test: single factor, t-test: two samples in pairs for mean and t-test: Two samples assuming different variances. The results of the present study pointed out that the oscillation of the CoP in the quiet standing position with open eyes, are altered by the conditions in which the cephalic segment is in motion, independent of slope, slope and horizontal situations, Aged 60 years or over

Conselho Nacional de Desenvolvimento Científico e Tecnológico / A fase cefálica de secreção de insulina (FCSI) ocorre dentro da fase cefálica da digestão, em aproximadamente dez minutos entre a estimulação oro-sensorial pelo alimento e o início da absorção deste e determina um incremento rápido dos níveis basais de insulina. A FCSI parece ser importante para a tolerância normal à glicose. A hipótese deste estudo é de que a insulina secretada na fase cefálica da digestão teria ações direcionadas para o tecido microvascular, com conseqüente recrutamento capilar. Estudos recentes com indivíduos sadios têm mostrado a associação entre função microvascular e componentes dietéticos. Padrões alimentares saudáveis e intervenções nutricionais com alimentos específicos representam estratégias preventivas e terapêuticas não-farmacológicas para redução da inflamação e do risco metabólico e cardiovascular associados. O estudo de consumo alimentar inserido nesta pesquisa objetivou identificar associações entre componentes dietéticos e a função microvascular em indivíduos saudáveis. Após avaliação clínica e laboratorial, 39 voluntários saudáveis foram submetidos a dois exames de videocapilaroscopia do leito ungueal, com um intervalo de dez minutos entre os mesmos. Neste intervalo, conforme randomização, uma refeição com ótima apresentação e aroma foi apresentada (estímulo sensorial) ou não (controle). Coletas sangüíneas foram realizadas aos 3, 9 e 15 minutos após a apresentação do estimulo, para avaliação dos níveis de insulina e polipeptídeo pancreático (PP), marcadores bioquímicos da fase cefálica da digestão. Durante todo o exame medidas de fluxo e vasomotricidade foram realizadas pela técnica de laser-Doppler fluxometria. Após o exame, foi realizada iontoforese transdérmica de insulina. Todos os participantes responderam a um questionário de freqüência alimentar (QFA), relativo ao hábito de consumo dietético dos últimos 12 meses. O estudo da resposta microvascular à fase cefálica comparou as diferenças de densidade capilar funcional e fluxo capilar nos grupos experimental e controle, antes e após o estímulo sensorial, e sua correlação com a variação de insulina e PP. O estudo de consumo alimentar avaliou correlações entre componentes dietéticos e recrutamento capilar no exame basal (antes do estímulo) em toda amostra. Após o intervalo, o grupo que recebeu o estímulo sensorial teve sua densidade capilar funcional (DCF) aumentada. A variação de insulina não diferiu entre os grupos e a de PP foi maior no grupo estimulado, sendo também correlacionada positivamente como aumento na DCF. A velocidade máxima de perfusão pósisquemia também aumentou no grupo estimulado, enquanto o tempo para alcançar esta velocidade máxima diminuiu. O estudo do consumo alimentar revelou associações positivas entre o consumo de cálcio, selênio e laticínios e recrutamento capilar na amostra total. Em conclusão, o consumo alimentar de cálcio, selênio e laticínios foi associado com maior recrutamento capilar em indivíduos sadios. Nestes indivíduos a microcirculação cutânea respondeu ao estímulo da fase cefálica da digestão com recrutamento capilar e aumento de fluxo sanguíneo microvascular. / The cephalic phase of insulin secretion (CPIS) occurs within the cephalic phase of digestion, in approximately ten minutes between the oral-sensorial stimulation elicited by the food to be consumed and the beginning of its absorption. It determines a rapid increase in insulin levels. The CPIS is believed to be important for normal glucose tolerance. The hypothesis of this study is that insulin secreted during cephalic phase would also have actions targeting microvascular tissue, with resulting capillary recruitment. Recent studies with healthy subjects have shown an association between microvascular function and dietary factors. Healthy eating patterns and nutritional interventions with specific food items represent non-pharmacological preventive and therapeutic strategies for reducing inflammation and cardio-metabolic associated risk factors. The study of food intake included in this research aimed to identify associations between dietary intake and microvascular function in healthy subjects. After clinical and laboratorial assessment, 39 healthy men underwent two nailfold videocapillaroscopies, with an interval of 10 minutes between them. In this interval, according to randomization, they were subjected to a great-looking breakfast tray (CPIS group) or to nothing (control group). Blood samples were drawn at 3, 9 and 15 minutes after the stimulus presentation to assess insulin and pancreatic polypeptide (PP) levels, which are markers of cephalic phae of digestion. Throughout the exam, microflow and vasomotion were measured by laser-Doppler flowmetry. After the exam insulin iontophoresis was performed. All participants answered a food-frequency questionnaire (FFQ) regarding their dietary intake in the last 12 months. The assessment of microvascular response to CPIS compared differences in functional capillary density (FCD) and microflow in the CPIS and control groups, pre- and post-stimulus and their correlations with changes in insulin and PP. The study of food intake attempted to identify correlations between dietary factors and functional capillary recruitment pre-stimulus in the total sample. After the interval, the CPIS group had significantly increased basal and peak FCD. Insulin variation was not different between groups. PP was significantly increased in the CPIS group and its variation was positively correlated with FCD increase. Resting red blood cell velocity (RBCV) and peak RBCV were also significantly increased and time taken to reach peak RBCV, decreased. The study of food intake revealed positive associations between calcium, selenium and dairy intakes and functional capillary recruitment in the total sample. In conclusion, skin microcirculation is activated during cephalic phase of digestion. Selenium, calcium and dairy intakes are positively associated with capillary recruitment in healthy men.

<p><strong>Background </strong>External cephalic version (ECV) is an effective intervention to reduce breech presentation and the corresponding Caesarean section (CS) rate. The Early ECV (EECV) trials were international multicentre randomized controlled trials that compared the timing of ECV (early or delayed) on obstetric and neonatal outcomes. In consideration of current recommendations that multicentre trials should account for centre effects in their analysis, a secondary analysis of the EECV trials was undertaken.</p> <p><strong>Purpose</strong> To analyse the EECV Trial data using statistical methods that account for centre effect and compare the results to standard analysis.<strong></strong></p> <p><strong>Methods </strong>Fisher’s exact test was used to provide overall results unadjusted for centre effects. The outcomes of interest were CS, preterm birth, and non-cephalic presentation at birth.</p> <p>Seven statistical models that accounted for centre effects were applied to the data: i) Mantel-Haenzsel test, ii) fixed effects regression, iii) fixed effects regression with a treatment-by-centre interaction term (weighted and iv) un-weighted by centre size), v) random intercept model, vi) random intercept and random slope model, and vii) generalized estimating equations.</p> <p><strong>Results </strong>Accounting for centre effects showed strengthened statistical associations with point estimates moving away from the null value.</p> <p><strong>Conclusion </strong>Effect estimates and confidence intervals changed for the three selected outcomes after accounting for centre effects, but the overall conclusions of the trial did not change. For this application, the Mantel-Haenzsel test and the random effects regressions performed the best. This study provides empirical evidence to support recommendations that multicentre trials account for centre in both design and analysis.</p> / Master of Health Sciences (MSc)

Arapaima gigas is the largest scaled freshwater fish in the world reaching over 250 kg. With growth rates of 10 kg+ within 12 months, A. gigas is considered as a promising candidate species for aquaculture development in South America. However, the lack of reproductive control in captivity is hindering the industry expansion. The work carried out in this doctoral thesis therefore aimed to better understand the species’ reproductive physiology, develop tools to identify gender and monitor gonad development, test hormonal therapies to induce ovulation and spawning and characterise the cephalic secretion for its potential roles in pheromone release and during parental care. Initially, a genomic study investigated the overall extent of polymorphism in A. gigas, which was found to be surprisingly low, with only 2.3 % of identified RAD-tags (135 bases long) containing SNPs. Then, a panel with 293 single nucleotide polymorphism (SNP) was used to characterise the genetic diversity and structure of a range of Amazon populations. Results revealed populations from the Amazon and Solimões appeared to be genetically different from the Araguaia population, while Tocantins population comprised individuals from both stocks. This data provided a tool for broodstock identification and future management. The PhD then aimed to evaluate the effects of slow-release mGnRH implants and different broodstock size pairings on maturation and spawning. Results showed that the implants stimulated the brain-pituitary-gonad axis resulting in increased plasma levels of testosterone (females) and 11-ketotestosterone in males, respectively regardless of pairing sizes. However, no spawning was observed. Results also showed the release of sex steroids with potential pheromonal action through the cephalic secretion, a biological fluid released from the adult head along the reproductive period. Thereafter, a non-surgical field endoscopy method was developed and validated for ovarian assessment and gender identification. The method was then used to describe the female gonopore and obtain biopsy of the ovary through cannulation which allowed the description of oogenesis in A. gigas. Importantly, oocytes obtained by cannulation confirmed that adult females under investigation were maturing with oocytes in final maturation stage but failed to ovulate/spawn. Another hormonal induction trial was therefore performed in which a combination of GnRHa (mGnRHa/sGnRHa) was used by injection to induce ovulation and spawning in selected maturing females with effects on oocyte maturation monitored post-induction through biopsy. However, this trial appeared to not be successful at inducing ovulation or spawning. Finally, the peptidome and proteome of the cephalic secretion was further characterised through the comparison between parental and non-parental fish. Results highlighted the complex role of this biological fluid including potential roles on the developing offspring during the parental care period. Overall, this doctoral thesis provided new basic and applied data on A. gigas reproduction and tools that can be used in future studies to better understand the environmental and hormonal control of oogenesis and spawning.

De fato, por não existir um levantamento antropométrico de crianças com síndrome de Down no Brasil, foi realizado em São Paulo um estudo biométrico prospectivo que permitiu a elaboração de curvas antropométricas avaliando taxas de peso, estatura e perímetro cefálico elaboradas por tabelas e gráficos com valores lapidados de 4 percentis de dois grupos etários de ambos os sexos divididos de 0-24 meses e de 2-8 anos respectivamente.o estudo considerou e excluiu, quando pertinente, fatores ambientais ou genéticos paralelos que eventualmente pudessem interferir nas variáveis avaliadas. A ampla revisão bibliográfica e a comparação dos dados antropométricos permitiram enfatizar a importância de curvas padrões nacionais para estatura, peso e perímetro cefálico de crianças com síndrome de Down, facilitando o diagnóstico diferencial entre outros comprometimentos clínicos, auxiliando na intervenção clínico-Iaboratorial, na prevenção e acompanhamento médico. / Considerint that there is any anthropometrical evaluation in children with Down\'s syndrome in Brazil, the objective of this prospective biometric investigation was to construct anthropometrical curves for weight, stature and cephalic perimeter in children with Down\' s syndrome living in São Paulo urban area. Ali measurements were obtained from January 1980 to December 1999. Ali height or cephalic perimeter values 10% below or above and weight values 16% below or above of the 1st and 3rd quartile were excluded. Tables for each sex during 0-24 months and 2-8 years were presented in mean, standard deviations, percentiles and quartiles and graphics were presented in percitiles. Environmental and genetic factors associated that could interfere in development were identified and the proband excluded from the sample. The employing of a national pattem curve of stature, weight and cephalic perimeter for individuaIs with Down\' s syndrome would be useful in differential diagnosis among other clinical disorders associated to this genetic malformation providing better clinical intervention and prevention of comorbidity.