51 research outputs found

    VIABILITY CHARACTERISTICS AND PHYSIOLOGICAL BEHAVIORS IN CABBAGE SEEDS IN DEPENDS ON STAGE OF MATURITY

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    The main purposes of the present study were to establish the changes during different stage of maturity and development of cabbage seed as well as earliest behaviors of viability and harvesting data. The experiments were carried out with two typical Bulgarian cultivars Balkan and Ditmarsko ranno. Samples of seeds in different days after fl owering – 30, 40, 50 and 60 days were analyzed. The physiological parameters and viability and vigor were investigated. The weight of one seeds was highest between 40 and 50 days. The primary germination was observed in seed harvested in 30 days, but the stability one was registered on 60 day. The intensity of respiration and activity of enzyme peroxides changed during seed development and maturity

    Fingerprints of extreme climate events in Pinus sylvestris tree rings from Bulgaria

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    Tree-ring studies may help better understand climate variability and extreme climate event frequency and are especially useful in regions where detailed meteorological records lack. We studied the effect of droughts and unusually cold periods on Pinus sylvestris tree-ring width and wood anatomy. Study sites were selected along an altitudinal gradient on Vitosha Mountain, Bulgaria. Drought conditions caused the formation of narrow tree rings or light rings if the drought occurred in July-August at the lower altitude sites. In years with droughts in June and the first half of July, followed by precipitation in the middle of July, intra-annual density fluctuations (IADFs) were formed. Trees in the zone with optimal growth conditions produced fewer light rings and narrow rings in years with either strongest droughts or unusually cold summers. At the timberline zone, low summer temperature triggered narrow tree rings and light rings. Frost rings were formed when there was a drop in temperatures below the freezing point in the second half of May or at the beginning of June. Our findings show that studies of tree-ring anatomy may contribute to obtain further knowledge about extreme climatic events in the Balkan Peninsula and in other regions where meteorological data lac

    In vitro скрининг Π·Π° Ρ…Π΅Ρ€Π±ΠΈΡ†ΠΈΠ΄Π½Π° сСлСктивност Π½Π° Π½ΠΎΠ²ΠΈ ΠΌΡƒΡ‚Π°Π½Ρ‚Π½ΠΈ Π³Π΅Π½ΠΎΡ‚ΠΈΠΏΠΎΠ²Π΅ ΠΏΠΈΠΏΠ΅Ρ€ с Ρ€Π°Π·Π»ΠΈΡ‡Π΅Π½ ΠΏΡ€ΠΎΠΈΠ·Ρ…ΠΎΠ΄ ΠΈ оцвСтяванС Π½Π° ΠΏΠ»ΠΎΠ΄Π°

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    The study presents an in vitro test development as a model for herbicide phytotoxicity. It provides reliable data on how the herbicide affects the seed germination and early growth stages, in dynamic, during the cultivation. The sensitivity of five mutant pepper genotypes with different origin and fruit colour to the herbicide napromamide (Devrinol 4F) was investigated. All studied herbicide doses, corresponding to 3, 4, and 5 L/ha, caused phytotoxicity expressed by decreased germination and growth inhibition. A strong genotype dependence was established – two breeding lines (18 and 85), originating from local populations, demonstrated a low sensitivity to the herbicide, additionally confirmed by higher plant survival and adaptability after transplanting to soil ex vitro.Π’ΠΎΠ²Π° ΠΏΡ€ΠΎΡƒΡ‡Π²Π°Π½Π΅ прСдставя Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚Π²Π°Π½Π΅Ρ‚ΠΎ Π½Π° in vitro ΠΏΡ€ΠΎΡ‚ΠΎΠΊΠΎΠ» ΠΊΠ°Ρ‚ΠΎ ΠΌΠΎΠ΄Π΅Π» Π·Π° Ρ…Π΅Ρ€Π±ΠΈΡ†ΠΈΠ΄Π½Π° фитотоксичност. Π§Ρ€Π΅Π· Π½Π΅Π³ΠΎ сС осигуряват Π½Π°Π΄Π΅ΠΆΠ΄Π½ΠΈ Π΄Π°Π½Π½ΠΈ Π·Π° Ρ‚ΠΎΠ²Π° ΠΊΠ°ΠΊ Ρ…Π΅Ρ€Π±ΠΈΡ†ΠΈΠ΄ΡŠΡ‚ влияС Π½Π° ΠΊΡŠΠ»Π½ΡΠ΅ΠΌΠΎΡΡ‚Ρ‚Π° ΠΈ Ρ€Π°Π½Π½ΠΈΡ‚Π΅ Ρ„Π°Π·ΠΈ Π½Π° растСТ, Π² Π΄ΠΈΠ½Π°ΠΌΠΈΠΊΠ° ΠΏΠΎ Π²Ρ€Π΅ΠΌΠ΅ Π½Π° ΠΊΡƒΠ»Ρ‚ΠΈΠ²ΠΈΡ€Π°Π½Π΅Ρ‚ΠΎ. ИзслСдвана Π΅ чувствитСлността Π½Π° ΠΏΠ΅Ρ‚ новосСлСктирани Π³Π΅Π½ΠΎΡ‚ΠΈΠΏΠΈ ΠΏΠΈΠΏΠ΅Ρ€ с Ρ€Π°Π·Π»ΠΈΡ‡Π΅Π½ ΠΏΡ€ΠΎΠΈΠ·Ρ…ΠΎΠ΄ ΠΈ цвят Π½Π° ΠΏΠ»ΠΎΠ΄Π° към Ρ…Π΅Ρ€Π±ΠΈΡ†ΠΈΠ΄Π° Π½Π°ΠΏΡ€ΠΎΠΌΠ°ΠΌΠΈΠ΄ (Devrinol 4F). Всички ΠΏΡ€ΠΈΠ»ΠΎΠΆΠ΅Π½ΠΈ Π΄ΠΎΠ·ΠΈ Π½Π° Ρ…Π΅Ρ€Π±ΠΈΡ†ΠΈΠ΄Π°, прСизчислСни към 3, 4 ΠΈ 5 L/ha, причиняват фитотоксичност, която сС проявява Ρ‡Ρ€Π΅Π· намаляванС ΠΊΡŠΠ»Π½ΡΠ΅ΠΌΠΎΡΡ‚Ρ‚Π° Π½Π° сСмСната ΠΈ ΠΈΠ½Ρ…ΠΈΠ±ΠΈΡ€Π°Π½Π΅ Π½Π° растСТа. УстановСна Π΅ силна Π³Π΅Π½ΠΎΡ‚ΠΈΠΏΠ½Π° зависимост - Π΄Π²Π΅ ΠΎΡ‚ Π»ΠΈΠ½ΠΈΠΈΡ‚Π΅ (18 ΠΈ 85), ΠΏΡ€ΠΎΠΈΠ·Ρ…ΠΎΠΆΠ΄Π°Ρ‰ΠΈ ΠΎΡ‚ мСстни ΠΏΠΎΠΏΡƒΠ»Π°Ρ†ΠΈΠΈ, дСмонстрират ΠΏΠΎ-ниска чувствитСлност към Ρ…Π΅Ρ€Π±ΠΈΡ†ΠΈΠ΄Π°, която Π΄ΠΎΠΏΡŠΠ»Π½ΠΈΡ‚Π΅Π»Π½ΠΎ сС ΠΏΠΎΡ‚Π²ΡŠΡ€ΠΆΠ΄Π°Π²Π° ΠΈ Ρ‡Ρ€Π΅Π· ΠΏΠΎ-високата прСТивяСмост Π½Π° растСнията ΠΈ адаптивност слСд засаТданС Π² ΠΏΠΎΡ‡Π²Π° ex vitro

    How does dialect exposure affect learning to read and spell? An artificial orthography study

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    Correlational studies have demonstrated detrimental effects of exposure to a mismatch between a non-standard dialect at home and a mainstream variety at school on children’s literacy skills. However, dialect exposure often is confounded with reduced home literacy, negative teacher expectation and more limited educational opportunities. To provide proof of concept for a possible causal relationship between variety mismatch and literacy skills, we taught adult learners to read and spell an artificial language with or without dialect variants using an artificial orthography. In three experiments, we confirmed earlier findings that reading is more error-prone for contrastive words, i.e. words for which different variants exist in the input, especially when learners also acquire the joint meanings of these competing variants. Despite this contrastive deficit, no detriment from variety mismatch emerged for reading and spelling of untrained words, a task equivalent to non-word reading tests routinely administered to young school children. With longer training, we even found a benefit from variety mismatch on reading and spelling of untrained words. We suggest that such a dialect benefit in literacy learning can arise when competition between different variants leads learners to favour phonologically mediated decoding. Our findings should help to assuage educators’ concerns about detrimental effects of linguistic diversity

    Exposure to dialect variation in an artificial language prior to literacy training impairs reading of words with competing variants but does not affect decoding skills

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    Many bidialectal children grow up speaking a variety (e.g. a regional dialect) that differs from the variety in which they subsequently acquire literacy. Previous computational simulations and artificial literacy learning experiments with adults demonstrated lower accuracy in reading contrastive words for which dialect variants exist compared to non-contrastive words without dialect variants. At the same time, exposure to multiple varieties did not affect learners’ ability to phonologically decode untrained words; in fact, longer literacy training resulted in a benefit from dialect exposure as competing variants in the input may have increased reliance on grapheme-phoneme conversion. However, these previous experiments interleaved word learning and reading/spelling training, yet children typically acquire substantial oral language knowledge prior to literacy training. Here we used artificial literacy learning with adults to examine whether the previous findings replicate in an ecologically more valid procedure where word learning precedes literacy training. We also manipulated training conditions to explore interventions thought to be beneficial for literacy acquisition, such as providing explicit social cues for variety use and literacy training in both varieties. Our findings replicated the reduced accuracy for reading contrastive words in those learners who had successfully acquired the dialect variants prior to literacy training. This effect was exacerbated when literacy training also included dialect variation. Crucially, although no benefits from the interventions were found, dialect exposure did not affect reading and spelling of untrained words suggesting that phonological decoding skills can remain unaffected by the existence of multiple word form variants in a learner’s lexicon

    Effect of different age of pepper seeds on the vegetative behaviors and physiological status of seedlings

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    The aim of the present study was to evaluate the influence of the different age of pepper seeds on the changes of vegetative development and physiological status of the grown seedlings. Experiments were carried out with two pepper cultivars. The seeds were stored for 120 months in ambient conditions. Through 12 mounts the sowing quality was established. The vegetative experiments were conducted. Morphological behaviors, an intensity of respiration and guaiacol peroxidase enzyme activity in seeds and the leaf gas-exchange were measured. Pepper seeds preserve normal sowing quality for up to 4 years. The length of root and stem decrease during storage. The leaf-gaze exchange was inhibited for seedlings of aged seeds

    Linking gameplay metrics to computational thinking

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    Computational thinking (CT) is considered to be a fundamental skill underlying not only programming ability, but also an entire array of computational problem-solving competencies in a data-driven world. The need for accessible and engaging educational tools for CT has recently been acknowledged as significant by educational authorities. Glitchspace is a firstperson puzzle game where the player has to manipulate objects in the game world through a visual programming interface in order to escape the cybermaze and win. The game received critical acclaim for its innovative and engaging gameplay, including a British Academy Scotland Award (BAFTA). However, the educational potential of Glitchspace in relation to CT ability has not been sufficiently explored. As success at playing the game relies on the players’ ability to program the game world to suit their goals, it is hypothesised that common measurements of CT will positively correlate with game ability (measured by game metrics, such as completion times and number of failed attempts of various sub-tasks). We propose to develop methodologies to explore the relationship between gameplay behaviour and computational problem-solving ability in the game Glitchspace. Such methodologies will allow researchers to investigate which game mechanics elicit and promote CT in a reliable and measurable way. The outcome of this research will be of great value to instructional designers seeking to leverage games for CT education, as well as learning game analysts seeking to map gameplay behaviour to learning outcomes

    Biological characterstics and productivity of cape gooseberry (physalis peruviana L.) plants according to different term of seedling sowing

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    The main aim of this study was to investigate the effect of different time of sowing of seedlings on the behaviors of morphological development and productivity of cape gooseberry. The experiments were carried out with varieties Plovdiv and Obrazec 1 with 15-day sowing intervals between 01.03, 15.03. and 30.03. Phenological observations were done. Main morphological characteristics of the plants, in stages of flower buds, flowering and fruiting were investigated. Contents of dry matter, total sugar, total acid, vitamin C and pectin were analyzed. The highest productivity was established on 15.03. as the sowing date for both varieties with 40.83% (Plovdiv) and 16.07% (Obrazec 1) above the variant with the lowest yield

    Effect of Different Age of Pepper Seeds on the Vegetative Behaviors and Physiological Status of Seedlings

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    The aim of the present study was to evaluate the influence of the different age of pepper seeds on the changes of vegetative development and physiological status of the grown seedlings. Experiments were carried out with two pepper cultivars. The seeds were stored for 120 months in ambient conditions. Through 12 mounts the sowing quality was established. The vegetative experiments were conducted. Morphological behaviors, an intensity of respiration and guaiacol peroxidase enzyme activity in seeds and the leaf gas-exchange were measured. Pepper seeds preserve normal sowing quality for up to 4 years. The length of root and stem decrease during storage. The leaf-gaze exchange was inhibited for seedlings of aged seeds

    Biological Characterstics and Productivity of Cape Gooseberry (Physalis peruviana L.) Plants According to Different Term of Seedling Sowing

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    The main aim of this study was to investigate the effect of different time of sowing of seedlings on the behaviors of morphological development and productivity of cape gooseberry. The experiments were carried out with varieties Plovdiv and Obrazec 1 with 15-day sowing intervals between 01.03, 15.03. and 30.03. Phenological observations were done. Main morphological characteristics of the plants, in stages of flower buds, flowering and fruiting were investigated. Contents of dry matter, total sugar, total acid, vitamin C and pectin were analyzed. The highest productivity was established on 15.03. as the sowing date for both varieties with 40.83% (Plovdiv) and 16.07% (Obrazec 1) above the variant with the lowest yield
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