The nature and role of the basal pinacoderm of Corvomeyenia carolinensis Harrison (Porifera: Spongillidae) A histochemical and developmental study

Hydrobiologia ◽  
1972 ◽  
Vol 39 (4) ◽  
pp. 495-508 ◽  
Author(s):  
Frederick W. Harrison
Keyword(s):  
1983 ◽  
Vol 10 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Robyn Penman ◽  
Toni Cross ◽  
Jeannette Milgrom-Friedman ◽  
Russell Meares

ABSTRACTFunctional and referential changes in maternal speech were investigated in a developmental study of nineteen mother–infant dyads, using video recordings of their free play at three and six months. The role of the infant in influencing speech adjustments was investigated by analysing the relationships between different types of maternal speech and different infant behavioural modes. Three general modes were differentiated – Communicative, Praxic and Other – and, regardless of infant age, mothers were found to make some modifications to their speech style as a function of infant mode. Speech style also was found to change, at a pragmatic level, from three to six months. Both findings support the conclusion that maternal speech is influenced by non-linguistic behavioural ‘feedback’ from infants. However, a finding that affect-oriented speech is more sensitive to infant behaviour than informative speech supports Brown's (1977) contention that the maternal speech register is shaped by two relatively independent interpersonal functions – the affective and communicative components. It is argued that a fuller account of maternal conversational adjustments to prelingual infants requires both a dialogic and a monologic explanation.


2020 ◽  
Author(s):  
Kwi Shan Seah ◽  
Vinodkumar Saranathan

AbstractThe development of color patterning in lepidopteran wings is of fundamental interest in evolution and developmental biology. While significant advances have recently been made in unravelling the cell and molecular basis of lepidopteran pigmentary coloration, the morphogenesis of wing scales, often involved in structural color production, is not well understood. Contemporary research focuses almost exclusively on a few nymphalid model taxa (e.g., Bicyclus, Heliconius), despite an overwhelming diversity across lepidopteran families in the hierarchical nanostructural organization of the scale. Here, we present a time-resolved, comparative developmental study of hierarchical wing scale nanostructure in Parides eurimedes and other papilionid species. Our results uphold the putative conserved role of F-actin bundles in acting as spacers between developing ridges as previously documented in several nymphalid species. While ridges are developing, the plasma membrane manifests irregular crossribs, characteristic of Papilionidae, which delineate the accretion of cuticle into rows of planar disks in between ridges. Once ridges have grown, Arp2/3 appears to re-organize disintegrating F-actin bundles into a reticulate network that supports the extrusion of the membrane underlying the disks into honeycomb-like tubular lattices of air pores in cuticle. Our results uncover a previously undocumented role for F-actin in the morphogenesis of wing scale nanostructures prominently found in Papilionidae. They are also relevant to current challenges in engineering of mesophases, since understanding the diversity and biological basis of hierarchical morphogenesis may offer facile, biomimetic solutions.


Author(s):  
Kunyu Lian ◽  
Jie Ma ◽  
Feifei Liang ◽  
Ling Wei ◽  
Shuwei Zhang ◽  
...  

How frequently a character appears in a word (positional character frequency) is used as a cue in word segmentation when reading aloud in the Chinese language. In this study we created 176 sentences with a target word in the center of each. Participants were 76 college students (mature readers) and 76 third-grade students (beginner readers). Results show an interaction effect of age and positional frequency of the initial character in the word on gaze duration. Further analysis shows that the third-grade students’ gaze duration was significantly longer in high, relative to low, positional character frequency of the target words. This trend was consistent with refixation duration, and there was a marginally significant interaction between age and total fixation time. Overall, positional character frequency was an important cue for word segmentation in oral reading in the Chinese language, and third-grade students relied more heavily on this cue than did college students.


1974 ◽  
Vol 45 (1) ◽  
pp. 30 ◽  
Author(s):  
Stephen M. Kosslyn ◽  
Gordon H. Bower

2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Gaviria ◽  
Laura Quintanilla ◽  
María José Navas

Envy is the result of a social comparison that shows us a negative image of ourselves. The present study addresses the effect of the context of group comparison and group identification on children's expression of this emotion. Through different stories, participants aged between 6 and 11 years were exposed to four contexts of upward social comparison in which they had to adopt the role of the disadvantaged character. From their emotional responses and their decisions in a resource allocation task, three response profiles were created: malicious envy, benign envy, and non-envy. Although we found important differences between verbal and behavioral responses, the results showed greater envy, both malicious and benign, when the envied was an out-group. On the other hand, when the envied belonged to the in-group and competed with a member of the out-group, malicious but not benign envy practically disappeared. With age, envious responses decreased, and non-envious responses increased. The role of social identity in the promotion and inhibition of envy is discussed, as well as the acquisition of emotional display rules in the benign envy and non-envy profiles.


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