Solar array study for solar electric propulsion spacecraft for the Encke rendezvous mission

The work is described which was performed on the design, analysis and performance of a 20 kW rollup solar array capable of meeting the design requirements of a solar electric spacecraft for the 1980 Encke rendezvous mission. To meet the high power requirements of the proposed electric propulsion mission, solar arrays on the order of 186.6 sq m were defined. Because of the large weights involved with arrays of this size, consideration of array configurations is limited to lightweight, large area concepts with maximum power-to-weight ratios. Items covered include solar array requirements and constraints, array concept selection and rationale, structural and electrical design considerations, and reliability considerations

On the Effect of Technological Progress on Pollution: a New Distortion in an Endogenous Growth Model

We derive a model of endogenous growth with physical capital, human capital and technological progress through quality-ladders. We introduce welfare-decreasing pollution in the model, which can be reduced through the development of cleaner technologies. From the quantitative analysis of the model we show clear evidence that the new externality from technological progress to pollution considered in this model is sufficiently strong to induce underinvestment in R&D as an outcome of the decentralized equilibrium. An important policy implication of the main result of this article is a justification to subsidize the research in cleaner technologies.Environmental Pollution, R&D, Social Capital, Human Capital, Economic Growth

Mariner 9 Solar Array Design, Manufacture, and Performance

The mission of Mariner 9, the first spacecraft to orbit another planet, was to make scientific observations of the surface of Mars. Throughout this unique mission, the Mariner 9 solar array successfully supported the power requirements of the spacecraft without experiencing anomalies. Basically, the design of the solar array was similar to those of Mariners 6 and 7; however, Mariner 9 had the additional flight operational requirement to perform in a Mars orbit environment mode. The array special tests provided information on the current-voltage characteristics and array space degradation. Tests indicated that total solar array current degradation was 3.5 percent, which could probably be attributed to the gradual degradation of the cover glass and/or the RTV 602 adhesive employed to cement the cover glass to the solar cell

Molybdenum Cofactor Deficiency. A Differential Diagnosis in a Newborn with Seizures

Descrevemos um lactente com doença neurológica grave caracterizada por convulsões mioclónicas e tónicas, com início no período neonatal, refractárias a vários anticonvulsivantes, assim como, tetraparésia espástica. A tomografia computorizada e a ressonância magnética cerebrais evidenciaram imagens de leucomalácia periventricular e, posteriormente, de atrofia cerebral progressiva e encefalomalácia quística. Os exames bioquímicos e o estudo da actividade enzimática permitiram o diagnóstico de défice do cofactor molibdénio. O défice do cofactor molibdénio é uma doença rara, autossómica recessiva, que se comporta como um défice combinado da sulfito oxidase e da xantina desidrogenase (ou xantina oxidase) alterando o metabolismo das purinas e da cisteína. A terapêutica é controversa e o prognóstico reservado. O nosso objectivo é relembrar esta patologia no diagnóstico diferencial das convulsões neonatais e da encefalopatia hipóxico- -isquémica, sobretudo quando os exames imagiológicos sugerem lesões de leucomalácia no recém-nascido de termo. Salientamos a importância deste diagnóstico diferencial, apesar do prognóstico pobre, devido à possibilidade de aconselhamento genético adequado e diagnóstico pré-natal

Establishing the zebrafish as a model to study the genetics of nociception

Pain is crucial for survival, and the ability to detect potentially harmful stimuli and respond accordingly is evolutionarily conserved. However, pain can also be undesirable in several situations, such as chronic pain. Pain management represents an unmet clinical need, with promising drugs identified in pre-clinical studies in rodents often failing to produce analgesia in clinical trials. This highlights the need for a better understanding of the mechanisms underlying the processing of noxious stimuli. The zebrafish has been increasingly used as an animal model in various fields. In this study, I aimed to establish the zebrafish as a model to study the genetics of nociception. I first established an infrared laser assay to deliver temporally precise noxious heat stimuli, and studied the behavioural responses of tethered zebrafish larvae upon stimulation. I found that there are two components in these responses, which are temporally separated, have different properties, and can be modulated using chemicals. Then, I generated zebrafish F0 knockouts of ngfb, ntrk1 and prdm12b, the zebrafish orthologs of three genes known to play a critical role in human pain, both physiologically and pathologically. I observed anatomical defects in a subset of ntrk1 and prdm12b mutants. ntrk1 mutants that lacked anatomical defects showed no changes in their response to noxious heat. However, I found that the fast component of the response to the laser was nearly completely abolished in ngfb mutants which were otherwise normal. A genetic approach to the study of zebrafish nociception can be used to gain a mechanistic understanding of the genes, cells and pathways involved in sensing noxious stimuli and generating protective behaviours, which may help the development of better drugs and treatments for pain

Aromatic L-Aminoacid Decarboxylase Deficiency A Defect of the Neurotransmitter Metabolism with Severe Neurological Impairment

A descarboxilase dos L-aminoácidos aromáticos, um enzima piridoxina dependente, é responsável pela conversão da L-dopa em dopamina e do 5 hidroxitriptofano em serotonina. A deficiência desse enzima, um erro inato do metabolismo dos neurotransmissores, resulta numa doença autossómica recessiva com manifestações neurológicas graves. Os dois casos apresentados de deficiência da descarboxilase dos L-aminoácidos aromáticos, entidade pela primeira vez descrita no nosso país, apresentam características clínicas semelhantes, resultantes da disfunção do metabolismo aminérgico: hipotonia, distonia, atraso no desenvolvimento psicomotor, episódios de movimentos oculógiros, irritabilidade e instabilidade vasomotora. A tomografia computadorizada e a ressonância magnética cerebrais foram normais em ambos os casos. Os exames bioquímicos e o estudo da actividade enzimática permitiram fazer o diagnóstico de deficiência da descarboxilase dos L-aminoácidos aromáticos. O nosso objectivo é chamar a atenção para a necessidade de investigar os defeitos do metabolismo dos neurotransmilissores na presença de Uma doença neurológica crónica sem etiologia conhecida. A importância de colocar este diagnóstico diferencial, o mais precocemente possível, advém das possibilidades de terapêutica, aconselhamento genético adequado e diagnóstico pré-natal, já hoje existentes

Primary Disorders of Neurotransmitter Metabolism: Experience of a Tertiary Center

Neurotransmitter diseases are a group of inherited disorders attributable to a disturbance of neurotransmitter metabolism. Biogenic amines are neurotransmitters with multiple roles including psychomotor function, hormone secretion, cardiovascular, respiratory and gastrointestinal control, sleep mechanisms, body temperature and pain. Given the multiple functions of monoamines, disorders of their metabolism comprise a wide spectrum of manifestations, with motor dysfunction being the most prominent clinical feature. Methods: Case review of 12 patients from 4 families, with primary disorders of biogenic amine metabolism. Results: Aromatic L-amino acid decarboxylase deficiency (4 patients from 2 families), and GTP-cyclohydrolase (8 patients from 2 families) were the two diseases identified. Age at first symptoms varied between 2 months and 6 years. Developmental delay was present in all cases except 2 patients with GTP cyclohydrolase deficiency. The combination of axial hypotonia and limb dystonia was also frequent. Children with aromatic L-amino acid decarboxylase deficiency exhibited temperature instability, oculogyric crisis and disturbances of sleep. The index case of one family with GTP cyclohydrolase deficiency presented with Parkinsonism (bradykinesia, rigidity and hypomimia). Analysis of neurotransmitters and their metabolites in CSF was crucial for the identification of index cases. Response to therapy was variable but in general unsatisfactory except in a family with GTP cyclohydrolase deficiency. Conclusions: These disorders should be considered in the differential diagnosis of paediatric neurodegenerative diseases, in order to allow an adequate therapeutic trial that can favor prognosis

I am Smart, Therefore I Can: Examining the Relationship between IQ and Self-efficacy across Cultures

The purpose of this article is to examine the relationship between intelligence (IQ) and self-efficacy in children and adolescents living in the United States and Nicaragua. The sample consisted of 90 (46 male, 44 female) students (mean age = 11.57 years, SD = 3.0 years) referred by school administrators and faculty. United States (US) participants (n = 27) resided in rural counties in the Northwest. The other group consisted of 63 students from Central America. A comparison between groups revealed that in the US, sample higher grades and IQ scores are typically associated with higher levels of self-efficacy. However in the Nicaraguan sample, both IQ scores and grades were not associated with self-efficacy, although age was correlated with self-efficacy. Results suggest that the construct of self-efficacy might change depending on whether one belongs to an individualistic or collectivistic society. Additionally, the effects of socioeconomic factors might influence perceived ability even more than intellectual abilities

Validação da FACES IV: o funcionamento da família em diferentes etapas do ciclo vital

Objetivos: 1) traduzir e validar a Escala de Avaliação da Flexibilidade e Coesão Familiar – Versão IV (FACES IV) para a população portuguesa; 2) analisar as diferenças na perceção dos sujeitos acerca do funcionamento da sua família, em cada uma das etapas do ciclo vital. Participantes: Trezentas e oitenta e sete (387) famílias, num total de 1089 sujeitos com idades superiores a 12 anos, recrutados por conveniência a partir do método de bola de neve. Instrumentos: Escala de Avaliação da Flexibilidade e Coesão Familiar – Versão IV (FACES IV), Escala Familiar de Autorresposta – Versão II (SFI), Escala de APGAR Familiar e a Escala de Ajustamento Diádico (RDAS). Resultados: A tradução da FACES IV apresentou uma boa capacidade de corretamente avaliar as famílias funcionais e uma mediana capacidade de avaliar as famílias disfuncionais, face à necessidade de uma mais completa e posterior adequação das subescalas Emaranhada e Rígida para a cultura portuguesa. Foram encontradas diferenças significativas no funcionamento das famílias em diferentes etapas do ciclo vital, nomeadamente nas dimensões da coesão familiar, liderança, saúde/competência, comunicação e expressividade emocional. A coesão nas famílias diminuía ao longo do ciclo vital, apresentando valores mais altos na etapa de família com filhos na escola e mais baixos na etapa de família com filhos adolescentes e família com filhos adultos. A liderança na etapa de formação do casal era significativamente mais baixa do que nas etapas de família com filhos na escola e família com filhos adolescentes. As famílias demonstraram possuir uma maior capacidade de competência e saúde na etapa de família com filhos na escola do que na etapa de formação do casal. A comunicação e expressividade emocional na família diminuíam ao longo do ciclo vital, com valores significativamente mais altos para a etapa de família com filhos na escola e mais baixos nas etapas de família com filhos adolescentes e família com filhos adultos. / Objectives: 1) translate and validate the Family Adaptability and Cohesion Evaluation Scale – version IV (FACES IV) for the Portuguese population. 2) analyse differences in individual’s perception of family functioning, in different stages of the family life cycle. Participants: Three hundred and eighty seven (387) families, in a total of 1089 individuals with ages higher than 12, recruited by convenience using the snowball method. Instruments: the Family Adaptability and Cohesion Evaluation Scale – version IV (FACES IV), Self-Report Family Inventory – Version II (SFI-II), Family APGAR and the Revised Dyadic Adjustment Scale (RDAS). Results: The FACES IV translation proved to be very capable of assessing functional families and somewhat capable of assessing dysfunctional families, giving the need of a further and more complete adaptation of the Enmeshed and Rigid subscales to Portuguese culture. Significant differences in family functioning, within different stages of the family life cycle, were found, namely in family cohesion, leadership, health/competence, communication and emotional expressiveness. Cohesion in families decreased along the family life cycle, showing higher values in the family with children in school stage and lower values in the family with adolescent children and family with adult children stages. Leadership proved to be significantly lower in the couple formation stage than the family with children and school and family with adolescent children stages. Families showed a higher competence and health when in the stage of family with children in school compared to the couple formation stage. Quality of communication and emotional expressiveness decreased along the family life cycle, with values significantly higher for families with children in school and lower for families with adolescent children and adult children

Variscan deformation of the Hesperian massif in the Lousã mountain range (central Portugal)

[Abstract] The occidental region of the Central-Iberian Zone of the Variscan Iberian massif, in the central part of Portugal (Lousã mountain range), has a Variscan tectonostructural organization as the one recognized in the occidental border of the massif, in the Porto-Coimbra-Tomar shear zone. In the Iberian massif we can observe neo-proterozoic metasediments of the “Complexo Xisto-Grauváquico”, and important metasedimentary outcrops of Late Palaeozoic (Ordovician, Silurian and lower Devonian) rocks. Both are affected by the first regional variscan deformation phase (FH1), and later refolded by the second variscan deformation phase (FH2). This second regional variscan phase has a penetrative effect in the massif and develops a dextral, north-south, strike-slip faulting, associated with transpressive kinematic deformation (like a Riedel model) similar to the Porto-Coimbra-Tomar shear zone. Some geological examples observed and studied in the Lousã region are showed and discussed