Step by step optimization of a sperm cryopreservation protocol for spotted wolffish (Anarhichas minor Olafsen, 1772)

Spotted wolffish Anarhichas minor reproduction in captivity is dependent on in vitro fertilization. However, low sperm volume with relatively low cell concentration and the lack of gametes synchronization (simultaneous availability of mature eggs and sperm) represent a challenge for the industry. Thus, the development of protocols for sperm storage are crucial. Four sequential experiments were conducted to optimize a sperm cryopreservation protocol for this species. First, three different cryoprotectants (DMSO; 1, 2-propanediol; and methanol) at different concentrations (5, 10, and 20%) were tested for their toxicity. No significant differences (p > 0.05) were detected between the control samples and cryoprotectants at concentration up to 10% DMSO, 10% propanediol, and 20% methanol in terms of motility parameters. Second, using the highest non-toxic concentrations of cryoprotectants, sperm was cryopreserved in 0.5 mL straws, at different distances from the liquid nitrogen (1.5, 2.5, 4.5, and 7.5 cm) that correspond to different freezing rates. Motility parameters after freezing/thawing decreased for all the cryoprotectants (p  0.05) between the two thawing rates. The best results were obtained using 10% DMSO. Finally, the fertilization capacity of cryopreserved sperm (10% DMSO and thawed at 5 °C for 1 min) was tested against fresh sperm using two spermatozoa:egg ratios and 4 h gametes contact time. The ratio of eggs with normal cell cleavage, abnormal cleavage or undeveloped were counted at the 2-4 cell stage. Cryopreserved sperm showed lower fertilization capacity at a concentration of 5 × 104 spermatozoa:egg compared with fresh sperm (p  0.05). To cryopreserve spotted wolffish sperm it is recommended to use 10% DMSO, loaded in 0.5 mL straws, freeze at a height between 4.5 (-14.05 °C/min) and 7.5 cm (-5.9 °C/min) from liquid nitrogen for 10 min and thaw for 1 min at 5 °C (177.9 °C/min). In vitro fertilization with cryopreserved sperm should be performed with a concentration of at least 5 × 105 spermatozoa per egg.WOLFSTORE project (AF0078) supported by the MABIT program from Norway. JS was supported by a Cost action FA1205 AQUAGAMETE and an ERASMUS grant.info:eu-repo/semantics/publishedVersio

Large-scale instabilities in a STOVL upwash fountain

The fountain flow created by two underexpanded axisymmetric, turbulent jets impinging on a ground plane was studied through the use of laser-based experimental techniques. Velocity and turbulence data were acquired in the jet and fountain flow regions using laser doppler velocimetry and particle image velocimetry. Profiles of mean and rms velocities along the jet centreline are presented for nozzle pressure ratios of two, three and four. The unsteady nature of the fountain flow was examined and the presence of large-scale coherent structures identified. A spectral analysis of the fountain flow data was performed using the Welch method. The results have relevance to ongoing studies of the fountain flow using large eddy simulation techniques

O desenvolvimento do raciocínio proporcional num ambiente dinâmico de geometria dinâmica: ressonância de um programa de formação contínua em matemática - m@c2

A frequência do m@c2 – Programa de Formação Continua em Matemática com professores do 2º Ciclo do Ensino Básico da Universidade de Aveiro – inspirou e motivou uma professora, em parceria com o ex-formador, a conceber e implementar uma experiência de aprendizagem que pudesse contribuir para um mais sólido desenvolvimento d o raciocínio proporcional e da representação gráfica das situações em causa, envolvendo o conceito de função linear. Para a sua avaliação, desenvolveu-se um estudo de caso que envolveu uma turma do 6º ano de escolaridade. A análise qualitativa dos dados recolhidos permitiu concluir que a exploração de um ambiente dinâmico de geometria dinâmica – GeoGebra – pode criar condições para o desenvolvimento de tal compreensão.The frequency of the m@c2 - In training Program in Mathematics with teachers in the of Elementary School of the University of Aveiro - inspired and motivated a female teacher, in partnership with former trainer, to design and implement a learning experience that could contribute to a stronger development of proportional reasoning and graphical representation of the situations in question, involving the concept of linear function. For its assessment, a study case was developed involving a group of 6th grade. Qualitative analysis of the data collected showed that the exploitation of a dynamic geometry dynamic - GeoGebra - can create conditions for the development of such understanding.La frecuencia de la m@c2 - Programa de Formación Continua en Matemáticas con los maestros de tercer ciclo de Educación Primaria de la Universidad de Aveiro - inspiró y motivó una maestra, en colaboración con su ex formador, a diseñar y implementar una experiencia de aprendizaje que podría contribuir a un mayor desarrollo del razonamiento proporcional y de la representación gráfica de las situaciones en cuestión, lo que implica el concepto de función lineal. Para su evaluación, se desarrolló un estudio de caso que involucra a un grupo de sexto. El análisis cualitativo de los datos recogidos ha mostrado que la explotación de un ambiente dinámico de geometría dinámica - GeoGebra - puede crear las condiciones para el desarrollo de esa comprensión

Synthesis of sub-5 nm Co-doped SnO2_2 nanoparticles and their structural, microstructural, optical and photocatalytic properties

A swift chemical route to synthesize Co-doped SnO$_2$ nanopowders is described. Pure and highly stable Sn$_{1-x}$Co$_x$O$_{2-\delta}$ (0 $\le$ x $\le$ 0.15) crystalline nanoparticles were synthesized, with mean grain sizes < 5 nm and the dopant element homogeneously distributed in substitutional sites of the SnO$_2$ matrix. The UV-visible diffuse reflectance spectra of the Sn$_{1-x}$Co$_x$O$_{2-\delta}$ samples reveal red shifts, the optical bandgap energies decreasing with increasing Co concentration. The Urbach energies of the samples were calculated and correlated with their bandgap energies. The photocatalytic activity of the Sn$_{1-x}$Co$_x$O$_{2-\delta}$ samples was investigated for the 4-hydroxylbenzoic acid (4-HBA) degradation process. A complete photodegradation of a 10 ppm 4-HBA solution was achieved using 0.02% (w/w) of Sn$_{0.95}$Co$_{0.05}$O$_{2-\delta}$ nanoparticles in 60 min of irradiation.Comment: 29 pages, 2 tables, 10 figure

Meningite Tuberculosa. Revisão de 7 Anos

A meningite tuberculosa é uma complicação grave da infecção pelo Mycobacterium tuberculosis. Entre 1 de Janeiro 1989 e 31 de Dezembro de 1995 foram internadas 14 crianças na Unidade de Doenças Infecciosas do Serviço 2 do Hospital D. Estefânia (HDE), por meningite tuberculosa, enquanto nos 6 anos anteriores, tinham sido admitidas 22 crianças, com a mesma patologia. A maioria das crianças tinha idade superior a 5 anos (64%). A fonte de contágio foi identificada em 35,7% dos casos e 79% tinham sido vacinadas com BCG. Em 78,5% foi detectado compromisso neurológico focal. Todas fizeram tratamento com 4 antibacilares. Houve necessidade de intervenção neurocirúrgica em 21% dos doentes. Em 57% dos casos persistiram sequelas neurológicas no final do tratamento. Não se registaram casos de morte

Dor em portadores de próteses totais primárias da anca: causas e avaliação clínica

Apesar da prótese total primária da anca ser referenciada como uma das endopróteses com maior sucesso em Ortopedia, uma pequena percentagem de doentes desenvolve um quadro doloroso localizado na anca num curto, médio ou a longo prazo, que pode ou não ser provocado pelo implante. A razão da persistência da dor após a implantação de uma prótese da anca pode ser sustentada por fatores intrínsecos, por fatores extrínsecos loco-regionais ou por outros fatores extrínsecos. O estudo das próteses da anca não pode ser feito isoladamente, deve estar integrado no complexo funcional vertebro-pélvico-femoral. Assim, tendinopatias dos músculos glúteos, do psoas-ilíaco, dos adutores, dos isquiotíbiais ou as afeções da coluna lombar, da articulação sacroilíaca ou do joelho homolateral e, ainda, afeções vasculares, nervosas e fatores psicológicos podem justificar a presença da dor. Neste contexto, o desprendimento assético e a infeção periprotética são dois importantes fatores que poderão estar na origem da dor na anca após uma prótese total da anca e devem, desde logo, ser excluídos antes de se considerarem outras causas menos comuns. Se não existir, aparentemente, uma razão que justifique a dor, o doente deve ser considerado como tendo uma infeção periprotética até prova do contrário. A anamnese e o exame físico, complementados por provas laboratoriais sanguíneas e do aspirado articular ou periarticular e, ainda, pelos exames imagiológicos, constituem os pilares sobre os quais assenta o diagnóstico das diferentes afeções que podem estar na génese da dor. Com efeito, o hemograma com fórmula leucocitária, a velocidade de sedimentação, a proteína C reativa, os exames radiográficos em diferentes incidências, a ecografia, a artrocentese com estudo citológico, microbiológico, cultura e antibiograma do aspirado articular, a tomografia axial computorizada quando indicada, são instrumentos valiosos para se conseguir alcançar um diagnóstico definitivo. Identificada a etiologia da dor, torna-se possível definir a estratégia terapêutica mais indicada, que é necessariamente diferente de um caso para outro. Constitui um princípio crucial só iniciar a terapêutica após o conhecimento do diagnóstico, quer se trate de uma abordagem conservadora ou, sobretudo, de uma intervenção cirúrgica. As dores inexplicáveis, de causa desconhecida, não encontram indicação para uma intervenção cirúrgica, assim como não é de aceitar a origem periarticular da dor sem terem sido eliminadas todas as causas de dor relacionadas com a prótese. A intervenção cirúrgica com a finalidade de se proceder a uma eventual recolocação artroplástica, sem prévio esclarecimento da etiologia da dor, não é uma boa prática produz, muitas vezes, um pobre resultado clínico

An introduction to the letters of Isaiah Moteka: The correspondence of a twentieth-century South African Zionist minister

ABSTRACTSouth African Zionism, one of the most popular Christian movements in modern South Africa, has frequently been interpreted in narrowly indigenous terms, as a local, black appropriation of Christianity, heavily invested in orality and ritual performance. The correspondence of the twentieth-century Zionist minister Isaiah Moteka tells a different story. Moteka honed the craft of letter-writing in order to build and sustain his relationship with Zion, Illinois, the headquarters of the worldwide Zionist church. Through the exchange of letters across the Atlantic, Moteka affirmed his own and his congregants’ place within a multiracial Zion diaspora. And through their complex invocation of overlapping local and global affiliations, Moteka's writings proclaimed his standing both as a regional clergyman and as a cosmopolitan internationalist. In particular, these ambiguous missives became the platform for Moteka's engagement with apartheid-era state officials. Seeking to persuade state officials that his organization fell under ‘white’ supervision, Moteka's letters proclaimed his accreditation by Zion, Illinois, thereby casting himself as a deputy of the worldwide movement. But these documents’ citation of transatlantic loyalties also suggests Moteka's own conflicted loyalties. His letters asserted loyalty to the nation state while they simultaneously subordinated earthly power to the Kingdom of God.This is the accepted version of an article originally published by Cambridge University Press in the journal Africa. The final version of record is available online at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9230222

Thermal restraint and fire resistance of columns

A proposal is made, based on the results of a series of tests and calculations, with the aim of being used as a simple method to correct the value of the critical temperature of steel columns free to elongate, in order to take into account the restraint effect of the structure to which they belong in a practical situation. To better illustrate the possible types of behaviour of heated steel columns with elastic restraint to the thermal elongation, and the reasons why the critical temperature of axially loaded slender steel columns with thermal restraint can sometimes be lower than the critical temperature of the same columns free to elongate, a simple model is presented and used in a qualitative analysis.http://www.sciencedirect.com/science/article/B6V37-46WW50B-1/1/139a30367738460772843d1279c4c32

Techniques of intestinal transplantation in rat

Two surgical models of intestinal transplantation in the rat are described. One is the implantation of fetal and newborn intestine as free grafts into the omentum of adult recipients, the other the adult intestine transplantation as an accessory graft using vascular anastomoses. A hundred and sixteen small-bowel transplantations were done; 36 of which were fetal intestine (group I), 40 of newborn intestine (group II), and 40 of adult intestine (group III). In the fetal and newborn intestinal transplantation, we emphasize the practices that allowed us to avoid ischemic and traumatic injury to the graft. In the adult intestine transplantation with vascular anastomoses, we heighten the modifications in the surgical technique that made the operation easier and the strategies used to prevent hypothermia and hypovolemic shock. Once experienced with the two chosen surgical techniques, transplantation using an avascular segment became much easier and quicker than transplantation with vascular anastomose