The Genetic Origins of Biosynthesis and Light-Responsive Control of the Chemical UV Screen of Land Plants

1994 ◽  
pp. 179-192 ◽  
Author(s):  
Richard Jorgensen
Keyword(s):  
Land Plants ◽  
Genetic Origins

Language in mental retardation: Individual and syndromic differences, and neurogenetic variation 1Based on a keynote presentation at the Third European Conference on Psychological Theory and Research in Mental Retardation, Geneva, September 1st, 2000.

2001 ◽  
Vol 60 (3) ◽  
pp. 161-178 ◽  
Author(s):  
Jean A. Rondal
Keyword(s):  
Mental Retardation ◽  
Language Development ◽  
Oral Language ◽  
Psychological Theory ◽  
Genetic Syndromes ◽  
Explanatory Variables ◽  
Keynote Presentation ◽  
Genetic Origins ◽  
The Sixties ◽  
The Individual

Predominantly non-etiological conceptions have dominated the field of mental retardation (MR) since the discovery of the genetic etiology of Down syndrome (DS) in the sixties. However, contemporary approaches are becoming more etiologically oriented. Important differences across MR syndromes of genetic origin are being documented, particularly in the cognition and language domains, differences not explicable in terms of psychometric level, motivation, or other dimensions. This paper highlights the major difficulties observed in the oral language development of individuals with genetic syndromes of mental retardation. The extent of inter- and within-syndrome variability are evaluated. Possible brain underpinnings of the behavioural differences are envisaged. Cases of atypically favourable language development in MR individuals are also summarized and explanatory variables discussed. It is suggested that differences in brain architectures, originating in neurological development and having genetic origins, may largely explain the syndromic as well as the individual within-syndrome variability documented. Lastly, the major implications of the above points for current debates about modularity and developmental connectionism are spelt out.

Iron content of selected water and land plants

1960 ◽  
Keyword(s):  
Iron Content ◽  
Land Plants

Status of Family Fissidentaceae in Gujarat

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar
Keyword(s):  
Distinct Species ◽  
The State ◽  
The Other ◽  
Land Plants ◽  
Reproductive Structures ◽  
The Family ◽  
The Status ◽  
Vegetative Characters ◽  
First Time ◽  
Different Parts

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.

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