997 resultados para Early maps.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

GERMINATION transfers a metabolically inert embryo into an active state of growth and development. The presence of conserved mRNAs has been demonstrated in different species of eggs and seeds1–4. In rice embryos, germination was shown to be independent of the synthesis of RNA up to 18–24 h after the start of imbibition5, although RNA synthesis was detected as early as 9 h after the start of imbibition. In this report, the sequence of the transcriptional events taking place during the early phase of the germination of rice embryos are presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In a study undertaken in Queensland, Australia, analysis of a survey that included both qualitative and quantitative questions revealed that, like their Japanese counterparts, early childhood teachers do not have well-developed ideas and practices in education for sustainability (EfS). Instead, they mainly practise traditional nature-based activities, such as gardening or playing outdoors, and teaching about resource conservation through books, posters or fact sheets. Teachers’ understandings of nature education, environmental education, and education for sustainability seem to influence their educational practices. Deeper understandings about sustainability are necessary to extend beyond such traditional practices. Even though national curriculum frameworks and guidelines point to the importance of sustainability within early childhood curriculum, these appear to be insufficient in strengthening early childhood teachers’ ideas of sustainability and how to practise it effectively. We suggest that it would be beneficial for early childhood teachers, both preservice and inservice, to have professional development opportunities that build deeper understandings of sustainability and its implementation in their settings.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The professionalism of early childhood teachers has been the subject of increasing attention globally for over a decade (Moss, 2006; Osgood, 2012; Urban, 2010. In order to understand ways pre-service early childhood teachers make sense of professionalism, this chapter examines some of the discourses of early childhood teacher professionalism, and focuses on qualifications as one way in which being professional is discursively produced. In particular, the chapter makes visible some of the discursive tensions involved in student intentions to pursue careers in primary school teaching/specialist early childhood teacher in primary school, rather than in the child care sector. In doing so, it makes visible some of the effects of particular discourses of professionalism and the ways they may be taken up by students as they make important career decisions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Despite considerable research on the impact of early childhood education (ECE), there is little empirical evidence about what the everyday work of educators entails. This paper reports on the development of a tool to capture generalisable data on the everyday work of educators so as to inform effective workforce policy. This tool—a taxonomy of early childhood educators’ work—was developed by drawing on the expertise of six early years’ experts from Australia and the United States of America (USA) and includes time-use diaries, focus groups and interviews with 21 early childhood educators working in long day care and preschool services. The taxonomy, which we present here, consists of 10 domains, each with a number of sub-classes. We propose that this taxonomy is a useful codification system for ascertaining the everyday work tasks, activities and actions of early childhood educators in diverse early years’ settings. It is anticipated that the taxonomy will prove a valuable tool for subsequent research investigating the early childhood workforce.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Most early career researchers in the first five years following doctoral qualification are faced with research challenges and opportunities, which necessitate the ability to navigate and overcome barriers, and to identify and benefit from possibilities. In this chapter, the authors outline an intentional mentoring initiative aimed at building the capacity of early career researchers within the Excellence in Research in Early Years Education Collaborative Research Network (CRN) in Australia. The initiative involved partnering early career researchers with experienced researchers and the inclusion of an early career representative on the network planning committee. The chapter discusses the many benefits for the mentee arising from the initiative including increased publication, momentum and confidence, as well as exposure to new methodologies, theoretical frameworks, and productive collaborative partnerships. It is hoped, however, that the findings will be of relevance to similar and diverse (funded/unfunded) research programs and collaborative networks wherever mentoring is applied as a capacity building strategy to assist researchers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The diversity of functions of eukaryotic cells is preserved by enclosing different enzymatic activities into membrane-bound organelles. Separation of exocytic proteins from those which remain in the endoplasmic reticulum (ER) casts the foundation for correct compartmentalization. The secretory pathway, starting from the ER membrane, operates by the aid of cytosolic coat proteins (COPs). In anterograde transport, polymerization of the COPII coat on the ER membrane is essential for the ER exit of proteins. Polymerization of the COPI coatomer on the cis-Golgi membrane functions for the retrieval of proteins from the Golgi for repeated use in the ER. The COPII coat is formed by essential proteins; Sec13/31p and Sec23/24p have been thought to be indispensable for the ER exit of all exocytic proteins. However, we found that functional Sec13p was not required for the ER exit of yeast endogenous glycoprotein Hsp150 in the yeast Saccharomyces cerevisiae. Hsp150 turned out to be an ATP phosphatase. ATP hydrolysis by a Walker motif located in the C-terminal domain of Hsp150 was an active mediator for the Sec13p and Sec24p independent ER exit. Our results suggest that in yeast cells a fast track transport route operates in parallel with the previously described cisternal maturation route of the Golgi. The fast track is used by Hsp150 with the aid of its C-terminal ATPase activity at the ER-exit. Hsp150 is matured with a half time of less than one minute. The cisternal maturation track is several-fold slower and used by other exocytic proteins studied so far. Operative COPI coat is needed for ER exit by a subset of proteins but not by Hsp150. We located a second active determinant to the Hsp150 polypeptide s N-terminal portion that guided also heterologous fusion proteins out of the ER in COPII coated vesicles under non-functional COPI conditions for several hours. Our data indicate that ER exit is a selective, receptor-mediated event, not a bulk flow. Furthermore, it suggests the existence of another retrieval pathway for essential reusable components, besides the COPI-operated retrotransport route. Additional experiments suggest that activation of the COPI primer, ADP ribosylation factor (ARF), is essential also for Hsp150 transport. Moreover, it seemed that a subset of proteins directly needed activated ARF in the anterograde transport to complete the ER exit. Our results indicate that coat structures and transport routes are more variable than it has been imagined.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Habitat requirements of fish are most strict during the early life stages, and the quality and quantity of reproduction habitats lays the basis for fish production. A considerable number of fish species in the northern Baltic Sea reproduce in the shallow coastal areas, which are also the most heavily exploited parts of the brackish marine area. However, the coastal fish reproduction habitats in the northern Baltic Sea are poorly known. The studies presented in this thesis focused on the influence of environmental conditions on the distribution of coastal reproduction habitats of freshwater fish. They were conducted in vegetated littoral zone along an exposure and salinity gradient extending from the innermost bays to the outer archipelago on the south-western and southern coasts of Finland, in the northern Baltic Sea. Special emphasis was placed on reed-covered Phragmites australis shores, which form a dominant vegetation type in several coastal archipelago areas. The main aims of this research were to (1) develop and test new survey and mapping methods, (2) investigate the environmental requirements that govern the reproduction of freshwater fish in the coastal area and (3) survey, map and model the distribution of the reproduction habitats of pike (Esox lucius) and roach (Rutilus rutilus). The white plate and scoop method with a standardized sampling time and effort was demonstrated to be a functional method for sampling the early life stages of fish in dense vegetation and shallow water. Reed-covered shores were shown to form especially important reproduction habitats for several freshwater fish species, such as pike, roach, other cyprinids and burbot, in the northern Baltic Sea. The reproduction habitats of pike were limited to sheltered reed- and moss-covered shores of the inner and middle archipelago, where suitable zooplankton prey were available and the influence of the open sea was low. The reproduction habitats of roach were even more limited and roach reproduction was successful only in the very sheltered reed-covered shores of the innermost bay areas, where salinity remained low (< 4‰) during the spawning season due to freshwater inflow. After identifying the critical factors restricting the reproduction of pike and roach, the spatial distribution of their reproduction habitats was successfully mapped and modelled along the environmental gradients using only a few environmental predictor variables. Reproduction habitat maps are a valuable tool promoting the sustainable use and management of exploited coastal areas and helping to maintain the sustainability of fish populations. However, the large environmental gradients and the extensiveness of the archipelago zone in the northern Baltic Sea demand an especially high spatial resolution of the coastal predictor variables. Therefore, the current lack of accurate large-scale, high-resolution spatial data gathered at exactly the right time is a considerable limitation for predictive modelling of shallow coastal waters.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

At 2-3 h after phenobaribtal administration, the drug has no effect on nucleoplasmic RNA synthesis and decreases nucleolar RNA synthesis. However, at this time there is an increase in the labelling of cytoplasmic poly(A)-containing RNA, even though there is decreased labelling of total polyribosomal RNA. The decrease in labelling of nucleolar and total polyribosomal RNA owing to phenobarbital is a transient phenomenon. Under similar conditions, 3-methylcholanthrene has no effect on nucleolar RNA synthesis, but leads to an increase in synthesis of nucleoplasmic and cytoplasmic poly(A)-containing RNA. Cytosol isolated from phenobarbital-treated, but not from 3-methyl-cholanthrene-treated, animals facilitates an enhanced transport of RNA from nuclei. At the time points investigated, 3-methylcholanthrene or its metabolite shows a 10-15-fold higher concentration in the chromatin than that of phenobarbital or its metabolite. It is suggested that the primary effect of phenobarbital is at the cytoplasmic level, promoting the transport of RNA from the nuclei, which can act as a trigger for enhanced transcription at later periods. 3-Methylcholanthrene or its metabolite directly binds to the chromatin and evokes a selective transcriptional response.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The PRP17 gene product is required for the second step of pre-mRNA splicing reactions. The C-terminal half of this protein bears four repeat units with homology to the beta transducin repeat. Missense mutations in three temperature-sensitive prp17 mutants map to a region in the N-terminal half of the protein. We have generated, in vitro, 11 missense alleles at the beta transducin repeat units and find that only one affects function in vivo. A phenotypically silent missense allele at the fourth repeat unit enhances the slow-growing phenotype conferred by an allele at the third repeat, suggesting an interaction between these domains. Although many missense mutations in highly conserved amino acids lack phenotypic effects, deletion analysis suggests an essential role for these units. Only mutations in the N-terminal nonconserved domain of PRP17 are synthetically lethal in combination with mutations in PRP16 and PRP18, two other gene products required for the second splicing reaction. A mutually allele-specific interaction between Prp17 and snr7, with mutations in U5 snRNA, was observed. We therefore suggest that the functional region of Prp17p that interacts with Prp18p, Prp16p, and U5 snRNA is the N terminal region of the protein.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In [8], we recently presented two computationally efficient algorithms named B-RED and P-RED for random early detection. In this letter, we present the mathematical proof of convergence of these algorithms under general conditions to local minima.