In the present study, the effect of phonological and working memory mechanisms involved in spelling Italian single words was explored in two groups of children matched for grade level: a group of ...normally hearing children and a group of pre-verbally deaf children, with severe-to-profound hearing loss. Three-syllable and four-syllable familiar words were presented to the two groups for spelling to dictation. Three conditions were used: simple spelling, concurrent articulation, and foot tapping. Verbal digit span was also assessed. Overall, the performance of deaf children tended to be lower compared to hearing children, but not significantly so. Concurrent articulation produced more errors than tapping in both groups. Regression analyses showed that the main predictor in all three tasks was school level, however the proportion of variance explained by this factor was much greater in the dual tasks, in particular in concurrent articulation. Qualitative analyses of errors showed a worse performance of deaf children, with a greater proportion of mixed errors compared to hearing children. They also showed a greater proportion of phonologically plausible errors compared to hearing children, presumably due to their deprived auditory representation, and/or to phonological representations that rely to a large extent on lip reading and kinesthetic and visual perception of articulatory gestures.
BACKGROUND: MADS-domain transcription factors play important roles during plant development. The Arabidopsis MADS-box gene SHORT VEGETATIVE PHASE (SVP) is a key regulator of two developmental phases. ...It functions as a repressor of the floral transition during the vegetative phase and later it contributes to the specification of floral meristems. How these distinct activities are conferred by a single transcription factor is unclear, but interactions with other MADS domain proteins which specify binding to different genomic regions is likely one mechanism. RESULTS: To compare the genome-wide DNA binding profile of SVP during vegetative and reproductive development we performed ChIP-seq analyses. These ChIP-seq data were combined with tiling array expression analysis, induction experiments and qRT-PCR to identify biologically relevant binding sites. In addition, we compared genome-wide target genes of SVP with those published for the MADS domain transcription factors FLC and AP1, which interact with SVP during the vegetative and reproductive phases, respectively. CONCLUSIONS: Our analyses resulted in the identification of pathways that are regulated by SVP including those controlling meristem development during vegetative growth and flower development whereas floral transition pathways and hormonal signaling were regulated predominantly during the vegetative phase. Thus, SVP regulates many developmental pathways, some of which are common to both of its developmental roles whereas others are specific to only one of them.
The goal of the present study was to investigate the time-course of suprasegmental information in visual word recognition. To this aim we measured event-related brain potentials (ERPs) during a ...simple lexical decision task in Italian. Two factors were manipulated: Stress dominance (the most frequent stress type) and stress neighborhood consistency (the proportion and number of existent words sharing orthographic ending and stress pattern). Participants were presented with target words either bearing dominant (on the penultimate syllable; 'graNIta,' 'seNIle,' slush, senile) or non-dominant stress (on the antepenultimate syllable; 'MISsile,' 'BIbita,' missile, drink), and either having a consistent (graNIta, MISsile) or an inconsistent stress neighborhood (seNIle, BIbita). Our results showed in the initial stages of processing an effect that we interpreted as an early orthographic marker of stress neighborhood in interaction with dominance. Later, from 250 ms after target onset, a marker of the lexical stress difference also emerged. The role of stress assignment in word recognition is discussed.
Auxin and Flower Development: A Blossoming Field Cucinotta, Mara; Cavalleri, Alex; Chandler, John William ...
Cold Spring Harbor perspectives in biology,
02/2021, Letnik:
13, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The establishment of the species-specific floral organ body plan involves many coordinated spatiotemporal processes, which include the perception of positional information that specifies floral ...meristem and floral organ founder cells, coordinated organ outgrowth coupled with the generation and maintenance of inter-organ and inter-whorl boundaries, and the termination of meristem activity. Auxin is integrated within the gene regulatory networks that control these processes and plays instructive roles at the level of tissue-specific biosynthesis and polar transport to generate local maxima, perception, and signaling. Key features of auxin function in several floral contexts include cell nonautonomy, interaction with cytokinin gradients, and the central role of MONOPTEROS and ETTIN to regulate canonical and noncanonical auxin response pathways, respectively.
flowers are not representative of the enormous angiosperm floral diversity; therefore, comparative studies are required to understand how auxin underlies these developmental differences. It will be of great interest to compare the conservation of auxin pathways among flowering plants and to discuss the evolutionary role of auxin in floral development.
Societal Impact Statement
Domesticated plants are essential for agriculture and human societies. Hence, understanding the processes of domestication will be crucial as we strive for more efficient ...crops and improvements to plants that benefit humankind in other ways. Here, we study the ornamental plant Sinningia speciosa, and reveal that despite the incredible variety found in domesticated varieties (e.g., in flower colour and form), they are all derived from a single founder population near Rio de Janeiro, Brazil. Knowledge of the domestication of horticultural plants is scarce and given its small, low‐complexity genome, and ease of cultivation, we suggest that S. speciosa is a good model for studying genomic variation during domestication.
Summary
The process of domestication often involves a complex genetic structure with contributions from multiple founder populations, interspecific hybridization, chromosomal introgressions, and polyploidization events that occurred hundreds to thousands of years earlier. These complex origins complicate the systematic study of the sources of phenotypic variation. The Florist's Gloxinia, Sinningia speciosa (Lodd.) Hiern, was introduced into cultivation in England two hundred years ago from botanical expeditions that began in the 18th century. Since that time, amateur plant breeders and small horticultural companies have developed hundreds of cultivars with a wide range of flower colors and shapes.
In our genetic study of S. speciosa, we examined an extensive diversity panel consisting of 115 individuals that included different species, wild representatives, and cultivated accessions.
Our analysis revealed that all of the domesticated varieties are derived from a single founder population that originated in or near the city of Rio de Janeiro in Brazil. We did not detect any major hybridization or polyploidization events that could have contributed to the rapid increase in phenotypic diversity.
Our findings, in conjunction with other features such as a small, low‐complexity genome, ease of cultivation, and rapid generation time, makes this species an attractive model for the study of genomic variation under domestication.
Domesticated plants are essential for agriculture and human societies. Hence, understanding the processes of domestication will be crucial as we strive for more efficient crops and improvements to plants that benefit humankind in other ways. Here, we study the ornamental plant Sinningia speciosa, and reveal that despite the incredible variety found in domesticated varieties (e.g., in flower colour and form), they are all derived from a single founder population near Rio de Janeiro, Brazil. Knowledge of the domestication of horticultural plants is scarce and given its small, low‐complexity genome, and ease of cultivation, we suggest that S. speciosa is a good model for studying genomic variation during domestication.
Italian vowels have a shorter duration before a geminate than before a singleton consonant, but a longer duration in syllables carrying stress. We asked whether children can produce the ...differentiation in vowel duration in singleton/geminate contexts reported for adults and whether their production changes depending on position of primary stress. Italian children (three-to-six-year-olds) and adults performed a nonword repetition. Each nonword appeared in four contexts, with the stressed/unstressed vowel preceding/following the singleton/geminate: /pa'paso/, /pap'paso/, 'papaso/, /'pappaso/. Acoustic analyses on the duration of the vowel preceding (V1) and following (V2) the medial consonant showed a type of consonant by age group interaction: the difference in vowel duration between children and adults was greater for geminate than singleton contexts, and was greater when the vowel carried stress. When V1 carried stress, its duration was shorter in the geminate than in the singleton in adults and older children, not in younger children.
Three lexical decision experiments were carried out in Italian, in order to verify if stress dominance (the most frequent stress type) and consistency (the proportion and number of existent words ...sharing orthographic ending and stress pattern) had an effect on polysyllabic word recognition. Two factors were manipulated: whether the target word carried stress on the penultimate (dominant; “graNIta,” “seNIle”—s
lush
,
senile
) or on the antepenultimate (non-dominant) syllable (“MISsile,” “BIbita”—
missile
,
drink
), and whether the stress neighborhood was consistent (graNIta, MISsile) or inconsistent (seNIle, BIbita) with the word’s stress pattern. In Experiment
1
, words were mixed with nonwords sharing the word endings, which made words and nonwords more similar to each other. In Experiment
2
, words and nonwords were presented in lists blocked for stress pattern. In Experiment
3
, we used a new set of nonwords, which included endings with (stress) ambiguous neighborhoods and/or with a low number of neighbors, and which were overall less similar to words. In all three experiments, there was an advantage for words with penultimate (dominant) stress and no main effect of stress neighborhood. However, the dominant stress advantage decreased in Experiments
2
and
3
. Finally, in Experiment
4
, the same materials used in Experiment
1
were also used in a reading-aloud task, showing a significant consistency effect but no dominant stress advantage. The influence of stress information in Italian word recognition is discussed.
•We examined whether Italian children exhibit adult-like stress contrastivity in their production of polysyllabic words.•Most of our normalised acoustic measures of vowel duration, intensity, and ...fundamental frequency showed that children's stress contrastivity was adult-like.•However, for trisyllabic words beginning with a weak–strong pattern children exhibited less stress contrastivity than adults in terms of vowel duration.•Differences in gemination between children and adults may affect contrastivity for words beginning with a weak–strong pattern.•Results discussed as language-specific versus physiological motor-speech constraints.
We examined whether typically developing Italian children exhibit adult-like stress contrastivity for word productions elicited via a picture naming task (n=25 children aged 3–5 years and 27 adults). Stimuli were 10 trisyllabic Italian words; half began with a weak–strong (WS) pattern of lexical stress across the initial 2 syllables, as in patata, while the other half began with a strong–weak (SW) pattern, as in gomito. Word productions that were identified as correct via perceptual judgement were analysed acoustically. The initial 2 syllables of each correct word production were analysed in terms of the duration, peak intensity, and peak fundamental frequency of the vowels using a relative measure of contrast—the normalised pairwise variability index (PVI). Results across the majority of measures showed that children's stress contrastivity was adult-like. However, the data revealed that children's contrastivity for trisyllabic words beginning with a WS pattern was not adult-like regarding the PVI for vowel duration: children showed less contrastivity than adults. This effect appeared to be driven by differences in word-medial gemination between children and adults. Results are compared with data from a recent acoustic study of stress contrastivity in English speaking children and adults and discussed in relation to language-specific and physiological motor-speech constraints on production.
•Lexical stress position is unpredictable in languages such as English or Italian.•A corpus analysis revealed the existence of sublexical cues to stress in Italian.•Results from a megastudy show ...Italian readers use those cues and lexical ones.•Our results can serve as benchmark for computational models of reading.•Our study provides a large database of stimuli and responses.
When reading polysyllabic words, assignment of lexical stress is a challenge for readers, especially in languages, such as English or Italian, in which stress position is not strictly determined even though words as well as nonwords typically contain several sublexical cues to stress that readers might use. Here, we attempted to identify such cues using a corpus analysis and to examine their impact on human performance in a megastudy in which participants (N = 45) assigned stress to nonwords (N = 800), stimuli particularly revealing of stress cue use because they have no predefined stress pattern. Hierarchical regression results confirmed an impact of sublexical cues examined in former studies and revealed a role for cues not previously examined, including similarity to real words. These results are informative for computational models of reading as they indicate that readers assign stress to nonwords based on not only sublexical but also lexical information.
In this study, stress diacritics were used to investigate the processing of stress information in lexical decision. We ran two experiments in Italian, a language in which stress position is not ...predictable by rule and only final stress—that is, the less common pattern—is orthographically marked with a diacritic. In Experiment 1, a lexical decision task, two factors were manipulated: the stress pattern of words—antepenultimate (nondominant) and penultimate (dominant)—and the presence/absence of the diacritics, signalling the stress position. Participants were faster to categorise stimuli as words when they bear dominant than nondominant stress. However, the advantage disappeared when the diacritic was used. In Experiment 2, a same-different verification task was used in which participants had to decide if a referent word and a target were same (carota-CAROTA, /ka’rɔta/; tavolo-TAVOLO, /’tavolo/) or different. We compared two conditions requiring a “different” response, in which referent and target with dominant and nondominant stress were congruent (caròta-CAROTA; tàvolo-TAVOLO) or incongruent (càrota-CAROTA; tavòlo-TAVOLO) with the word’s stress. For words with dominant stress, “different” responses were faster in the incongruent condition than the congruent condition. This congruency effect was not observed for words with nondominant stress pattern. Overall, the data suggest that stress information is based on lexical phonology, and the stress dominance effect has a lexical base in word recognition.
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