3,875 research outputs found
Correlating the interstellar magnetic field with protostellar jets and its sources
This article combines new CCD polarimetric data with previous information
about protostellar objects in a search for correlations involving the
interstellar magnetic field. Specifically, we carried out an optical
polarimetric study of a sample of 28 fields of 10 X 10 arcmin^2 located in the
neighborhood of protostellar jets and randomly spread over the Galaxy. The
polarimetry of a large number of field stars is used to estimate both the
average and dispersion of the interstellar magnetic field (ISMF) direction in
each region. The results of the applied statistical tests are as follows.
Concerning the alignment between the jet direction and the interstellar
magnetic field, the whole sample does not show alignment. There is, however, a
statistically significant alignment for objects of Classes 0 and I. Regarding
the interstellar magnetic field dispersion, our sample presents values slightly
larger for regions containing T Tauri objects than for those harboring younger
protostars. Moreover the ISMF dispersion in regions containing high-mass
objects tends to be larger than in those including only low-mass protostars. In
our sample, the mean interstellar polarization as a function of the average
interstellar extinction in a region reaches a maximum value around 3% for A(V)
= 5, after which it decreases. Our data also show a clear correlation of the
mean value of the interstellar polarization with the dispersion of the
interstellar magnetic field: the larger the dispersion, the smaller the
polarization. Based on a comparison of our and previous results, we suggest
that the dispersion in regions forming stars is larger than in quiescent
regions.Comment: ApJ accepte
Gender asymmetries in Portuguese trade unions: the case of the CGTP-IN
Gender imbalances persist throughout the world, particularly at leadership level, and equally also visible in the case of trade unions. This article focuses on CGTP-IN, the largest Portuguese trade union confederation, and sets out analysis incorporating both figures from this organisation and accounts by female members of CGTP-IN unions. Results confirm the existence of gender asymmetries, especially at the highest leadership levels. Analysis of the discourses of these women leaders reveals some awareness of the influence of gender on professional relations, placing women at a disadvantage, especially where leadership is concerned. Furthermore, four reasons driving the persistence of these gender asymmetries in trade union leadership/decision-making roles were identified: family responsibilities, gendered professional segregation, masculine trade union cultures and traditional gender stereotypes. Nevertheless, the interviewees resist to means of affirmative action such as gender quotas, and instead prefer to prioritise education and raising awareness around gender equality.info:eu-repo/semantics/publishedVersio
The Copepod Acartia tonsa as live feed for fat snook (Centropomus parallelus) larvae from notochord flexion to advanced metamorphosis.
From early development until the completion of metamorphosis, fat snook (Centropomus parallelus) larvae are commonly fed the rotifers Brachionus spp. and Artemia spp. nauplii. In this study, cultivated copepods Acartia tonsa were evaluated as feed for 15-to 45-day-old larvae. Two experiments were performed using twelve 30-L tanks stocked with 3.3 fat snook larvae L-1. Their initial mean weight and length were 1.35 ± 0.01 mg (mean ± standard deviation) and 3.83 ± 0.33 mm for 15-day-old larvae and 2.79 ± 1.2 mg and 6.99 ± 0.88 mm for 31-day-old larvae. Three dietary treatments were carried out in four replicates, including Rotifer (R), Artemia (A) and/or Copepod (C). Experiment 1 included Diet RA (control), Diet RC and Diet RCA; while experiment 2 included Diet A (control), Diet C and Diet AC. The survival and growth of larvae fed the Diet RCA in experiment 1 were significantly higher than the others. In experiment 2, the inclusion of copepods in the diet did not improve survival and growth, however, larvae fed Diet C had the highest DHA/EPA ratio. We conclude that the copepod Acartia tonsa provides an important nutritional benefit to fat snook larvae undergoing metamorphosis
Seleção de híbridos de bananeira ornamental para uso como flor de corte.
A bananeira ornamental constitui-se numa alternativa promissora para o segmento das fruteiras ornamentais. No Brasil, alguns genótipos já são comercializados, como a M. coccinea, M. ornata e M. velutina, no entanto, seu uso ainda é discreto e pouco explorado. A geração de novas variedades torna-se relevante nesse aspecto, haja vista que o mercado de flores e plantas ornamentais demanda por materiais inovadores (SOUZA, 2010)
Observations on parasite fauna of centropomus undecimalis and C. parallelus (perciformes) bred in southern Brazil, and its possible influence on the welfare of fishes.
The metazoan parasite fauna of snooks, Centropomus parallelus and Centropomus undecimalis, cultured in southern Brazil and parasite?s influence on the relative condition factor (Kn), are investigated. Snooks were parasitized by two species of gill monogeneans belonging to Rhabdosynochus (Diplectanidae) genus and by one endoparasitic digenean species Acanthocollaritrema umbilicatum (Acanthocollaritrematidae). Centropomus parallelus and C. undecimalis showed similar prevalence rates of Rhabdosynochus spp., but greater mean intensity and abundance rates were found in C. parallelus. On the other hand, there was no significant difference on prevalence, mean intensity and abundance of A. umbilicatumfor both hosts. The mean abundance of Rhabdosynochusspp. decreased as the hosts´ length and weight increased. Since the most parasitized fish species, C. parallelus, had lower weight than expected (Kn<1.0), the fact suggested that gill monogeneans might alter fish welfare. Current analysis reports a new host and a new locality for A. umbilicatum
Human embryonic stem cell-derivatives in a hydrogel-based skin model
Cases of massive skin loss upon injury or disease still represent a serious healthcare challenge worldwide, and despite the many alternatives
available, results are not yet satisfactory. Skin Tissue Engineering, especially now combined with Stem Cell Research, holds great
expectation towards an efficient and high quality skin regeneration. Human embryonic stem cells (hESCs) are quite attractive for this
purpose, as they possess both immunoprevileged features and unique self-renewal and differentiation potency, being able to provide
unlimited biological material. In this specific work, an innovative hydrogel-based model, together with hESCs-derived epidermal cells is
proposed for skin regeneration. hESCs were moved from Mouse embryonic fibroblasts (MEFs), cultured in a feeder-free system comprising
Matrigel and mTeSR media, and characterized by immunocytochemistry for pluripotency markers. After expansion, hESCs were
differentiated towards the epidermal lineage,by culturing them in Collagen IV coated dishes, and upon supplementation of both Retinoic
acid and bone morphogenetic protein 4. Keratin 18/14 positive cells were obtained, confirming the success of the used protocol.
Differentiated epidermal cells were purified and cultured onto the hydrogel. Following several culture methodologies optimization, hESCsderived
epidermal cells were able to adhere, proliferate and form a stratified epidermis-like structure demonstrating the potential and
expectation for Skin Regeneration
Efeito das doses de chorume tratado por eletro-fenton na germinação de sementes de girassol olerífero var. brs. 321 (helianthus annus l.)
Abrindo a caixa de pandora: a participação política das mulheres, as desigualdades de género e a ação positiva
Uma década após a aprovação da Lei da Paridade em Portugal, tornou-se imperativo explorar os efeitos simbólicos da representação descritiva das mulheres políticas (i.e., em termos numéricos) sobre as atitudes políticas das/os cidadãs/os portuguesas/es. Com este objetivo, realizámos um estudo que envolveu um questionário online dirigido à população portuguesa com mais de 18 anos. São apresentados os resultados de uma análise realizada com 291 participantes (83% do sexo feminino e 17% do sexo masculino), com idades entre 18 e 70 anos, dividida em três partes centradas na participação política das mulheres; nos estereótipos de género e na cobertura noticiosa de políticas/os; na Lei da Paridade e noutras medidas promotoras da igualdade. Os resultados indicam mudanças e continuidades, estando as/os portuguesas/es mais conscientes das desigualdades de género no contexto político e da importância de medidas para além da Lei da Paridade, face à qual continuam, apesar de tudo a perceber-se algumas resistências.info:eu-repo/semantics/publishedVersio
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