Ecophysiology of seed dormancy and the control of germination in early spring-flowering Galanthus nivalis and Narcissus pseudonarcissus (Amaryllidaceae)

Seed dormancy induction and alleviation in the winter-flowering moist temperate woodland species Galanthus nivalis and Narcissus pseudonarcissus are complex and poorly understood. Temperature, light and desiccation were investigated to elucidate their role in the germination ecophysiology of these species. Outdoor and laboratory experiments simulating different seasonal temperatures, seasonal durations, and temperature fluctuations; the presence of light during different seasons; and intermittent drying (during the summer period) over several ‘years’ investigated the importance of these factors in germination. Warm summer-like temperatures (20°C) were necessary for germination at subsequent cooler autumn-like temperatures (greatest at 15°C in G. nivalis and 10°C in N. pseudonarcissus). As the warm temperature duration increased so did germination at subsequent cooler temperatures; further germination occurred in subsequent ‘years’ at cooler temperatures following a second, and also third, warm period. Germination was significantly greater in darkness, particularly in G. nivalis. Dormancy increased with seed maturation period in G. nivalis, because seeds extracted from green capsules germinated more readily than those from yellow. Desiccation increased dormancy in an increasing proportion of N. pseudonarcissus seeds the later they were dried in ‘summer’. Seed viability was only slightly reduced by desiccation in N. pseudonarcissus but was poor and variable in G. nivalis. Shoot formation occurred both at the temperature at which germination was greatest and also if 5°C cooler. In summary, continuous hydration of seeds of both species during warm summer-like temperatures results in the gradual release of seed dormancy; thereafter, darkness and cooler temperatures promote germination. Cold temperatures, increased seed maturity (G. nivalis), and desiccation (N. pseudonarcissus) increase dormancy while light inhibits germination.

Early, late or very late? Timing acquisition and bilingualism

Research on child bilingualism accounts for differences in the course and the outcomes of monolingual and different types of bilingual language acquisition primarily from two perspectives: age of onset of exposure to the language(s) and the role of the input (Genesee, Paradis, & Crago, 2004; Meisel, 2009; Unsworth et al., 2014). Some findings suggest that early successive bilingual children may pattern similarly to simultaneous bilingual children, passing through different trajectories from child L2 learners due to a later age of onset in the latter group. Studies on bilingual development have also shown that input quantity in bilingual acquisition is considerably reduced, i.e., in each of their two languages, bilingual children are likely exposed to much less input than their monolingual peers (Paradis & Genesee, 1996; Unsworth, 2013b). At the same time, simultaneous bilingual children develop and attain competence in the two languages, sometimes without even an attested age delay compared to monolingual children (Paradis, Genesee & Crago, 2011). The implication is that even half of the input suffices for early language development, at least with respect to ‘core’ aspects of language, in whatever way ‘core’ is defined.My aim in this article is to consider how an additional, linguistic variable interacts with age of onset and input in bilingual development, namely, the timing in L1 development of the phenomena examined in bilingual children’s performance. Specifically, I will consider timing differences attested in the monolingual development of features and structures, distinguishing between early, late or ‘very late’ acquired phenomena. I will then argue that this three-way distinction reflects differences in the role of narrow syntax: early phenomena are core, parametric and narrowly syntactic, in contrast to late and very late phenomena, which involve syntax-external or even language-external resources too. I explore the consequences of these timing differences in monolingual development for bilingual development. I will review some findings from early (V2 in Germanic, grammatical gender in Greek), late (passives) and very late (grammatical gender in Dutch) phenomena in the bilingual literature and argue that early phenomena can differentiate between simultaneous and (early) successive bilingualism with an advantage for the former group, while the other two reveal similarly (high or low) performance across bilingual groups, differentiating them from monolinguals. The paper proposes that questions about the role of age of onset and language input in early bilingual development can only be meaningfully addressed when the properties and timing of the phenomena under investigation are taken into account.

Children's misconceptions and the teaching of early years science: a case study

The aim of this paper is to examine how teachers’ awareness of children’s misconceptions can affect children’s acquisition of scientific concepts. In other words, this paper is aimed at examining whether teaching is altered when teachers are aware of pupils’ misconceptions of a specific science concept. This paper details a case study focused on two kindergarten classes of five year-old children and their teachers and took place in Cyprus. Two lessons were observed and three children from each class were interviewed. Through the analysis of children’s responses it was possible to identify specific misconceptions related to the concept of rain. The results indicate that it is very important for teachers to be aware of what misconceptions children have, because this can help them plan lessons for children to overcome their misconceptions. It seems that it is more likely for children to overcome their misconceptions when teachers take these misconceptions into account as they plan and teach science lessons.

Long-term depression activates transcription of immediate early transcription factor genes: involvement of serum response factor/Elk-1

Long-term depression (LTD) is one of the paradigms used in vivo or ex vivo for studying memory formation. In order to identify genes with potential relevance for memory formation we used mouse organotypic hippocampal slice cultures in which chemical LTD was induced by applications of 3,5-dihydroxyphenylglycine (DHPG). The induction of chemical LTD was robust, as monitored electrophysiologically. Gene expression analysis after chemical LTD induction was performed using cDNA microarrays containing >7,000 probes. The DHPG-induced expression of immediate early genes (c-fos, junB, egr1 and nr4a1) was subsequently verified by TaqMan polymerase chain reaction. Bioinformatic analysis suggested a common regulator element [serum response factor (SRF)/Elk-1 binding sites] within the promoter region of these genes. Indeed, here we could show a DHPG-dependent binding of SRF at the SRF response element (SRE) site within the promoter region of c-fos and junB. However, SRF binding to egr1 promoter sites was constitutive. The phosphorylation of the ternary complex factor Elk-1 and its localization in the nucleus of hippocampal neurones after DHPG treatment was shown by immunofluorescence using a phosphospecific antibody. We suggest that LTD leads to SRF/Elk-1-regulated gene expression of immediate early transcription factors, which could in turn promote a second broader wave of gene expression.

Characterising the use of urban space: a geochemical case study from Calleva Atrebatum (Silchester, Hampshire, UK) Insula IX during the late first/early second century AD

The geochemical analysis of soil samples from the Roman town of Calleva Atrebatum (Silchester, Hampshire, UK) has been undertaken in order to enhance our understanding of urban occupation during the late first/early second century AD. Samples taken from a variety of occupation deposits within several, contemporary timber buildings, including associated hearths, have been analysed using laboratory-based x-ray fluorescence for a suite of elements (Cu, Zn, Pb, Sr, P and Ca). The patterns of elemental enrichment seen across the site have allowed us to compare and contrast the buildings that were occupied during this time in an attempt to distinguish different uses, such as between domestic and work-space. Two of the buildings stand out as having high concentrations of elements which suggest that they were dirtier work spaces, whilst other buildings appear to be have lower chemical loadings suggesting they were cleaner.

The aims of early years outdoor education in England: a conceptual and empirical investigation

This paper explores the place of aims in the early years foundation stage outdoor environment in England. Through examining the writing of academics, various themes are identified, and constructed into possible aims. These themes/aims are compared to an empirical study of early years teachers’ attitudes. Data was collected by questionnaire from schools within the University of Reading partnership. There was general agreement between experts and teachers as to the aims. While some respondents were able to explain what the aims of outdoor activity were, a significant number were unable to identify aims; further, a significant number did not distinguish between approach/practice and aims. A lack of understanding and agreement as to what the aims are may indicate teachers are unsure about the purpose of outdoor education for young children. A result of this study is to agree and make explicit the aims for outdoor education in the early years.

What is outside? The early years foundation stage in England: outdoor facilities, organisation and staff attitudes

The purpose of this paper is to report on the facilities available, organisation of, and staff attitudes to early years outdoor education from schools within the south east of England, focusing on provision for children aged three to five. One component of the successful education of the child involves providing an ‘environment for learning’, including the facilities, layout and routines. This paper presents findings concerning the type and variety of facilities available outside; the various styles of organisation of the space; staff attitudes about: their roles, their aims for the environment, children’s behaviour and learning, and perceived drawbacks to practice. This paper draws on empirical data collected from schools within the University of Reading partnership. The findings suggest that although all early years settings must adhere to the statutory framework there are a range of facilities available, and there are a number of ways this environment is organised. Further there appears to be uncertainty about the adult role outside and the aims for activities. The conclusions drawn indicate that staff do not appear to be linking their aims for outdoor education to the facilities provided or to their actions outside. This means there is not a clear link between what staff provide outside and the declared ambitions for learning. This study is important as all educators need to be certain about their aims for education to ensure best outcomes for children. The implications of these findings for early years teachers are that they need to be able to articulate their aims for outdoor education and to provide the correct facilities to achieve these aims. Finally this study was undertaken to raise debate, posit questions and to ascertain the parameters for further research about the early years outdoor environment.

Vegetation and soils feedbacks on the response of the African monsoon response to orbital forcing in early to middle Holocene

Fossil pollen, ancient lake sediments and archaeological evidence from Africa indicate that the Sahel and Sahara regions were considerably wetter than today during the early to middle Holocene period, about 12,000 to 5,000 years ago1–4. Vegetation associated with the modern Sahara/Sahel boundary was about 5° farther north, and there were more and larger lakes between 15 and 30° N. Simulations with climate models have shown that these wetter conditions were probably caused by changes in Earth's orbital parameters that increased the amplitude of the seasonal cycle of solar radiation in the Northern Hemisphere, enhanced the land-ocean temperature contrast, and thereby strengthened the African summer monsoon5–7. However, these simulations underestimated the consequent monsoon enhancement as inferred from palaeorecords4. Here we use a climate model to show that changes in vegetation and soil may have increased the climate response to orbital forcing. We find that replacing today's orbital forcing with that of the mid-Holocene increases summer precipitation by 12% between 15 and 22° N. Replacing desert with grassland, and desert soil with more loamy soil, further enhances the summer precipitation (by 6 and 10% respectively), giving a total precipitation increase of 28%. When the simulated climate changes are applied to a biome model, vegetation becomes established north of the current Sahara/Sahel boundary, thereby shrinking the area of the Sahara by 11% owing to orbital forcing alone, and by 20% owing to the combined influence of orbital forcing and the prescribed vegetation and soil changes. The inclusion of the vegetation and soil feedbacks thus brings the model simulations and palaeovegetation observations into closer agreement.