Genetic variation at allozyme and RAPD loci in sessile oak Quercus petraea (Matt.) Liebl.: the role of history and geography

1997 ◽  
Vol 6 (6) ◽  
pp. 519-529 ◽  
Author(s):  
V. Le Corre ◽  
S. Dumolin‐Lapègue ◽  
A. Kremer
Keyword(s):  
Genetic Variation ◽  
Quercus Petraea ◽  
Sessile Oak

Intra- and Inter-Tree Variability of Moisture Content in Standing Sessile Oak (Quercus petraea Liebl.)

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 117-124 ◽  
Author(s):  
T. Constant ◽  
G. Nepveu ◽  
F. Huber
Keyword(s):  
Moisture Content ◽  
Stand Structure ◽  
Tree Height ◽  
Quercus Petraea ◽  
Site Quality ◽  
Average Moisture Content ◽  
Sessile Oak ◽  
Tree Effect ◽  
The Individual

Summary Knowledge about the moisture content of trees in the forest or wood yard is scarce. The variation of moisture content within and between 20 boles of sessile oak was investigated using 1543 measurements performed at three heights in each tree and along 4 radii. Five radial positions were defined: sapwood, outer, intermediate and inner heartwood, and the core piece including the pith. Results show that the average moisture content is highly dependent on the individual. The average moisture content was around 80%(oven-dried basis), but it ranges from 65% to 100%depending on the tree. This “tree” effect is discussed and examined using some general characteristics of the trees (region, stand structure, site quality, dendrometric and densitometric traits). Apart from age counted from pith, and the ratio of tree height vs. diameter, no strong correlation appears. Moderate variations in moisture content with radial position and height are also brought to the fore. The specific role of sapwood, which exhibits a more variable moisture content is discussed.

Genetic background of cholesterol absorption efficacy. The role of Niemann–Pick C1-like 1 receptor and its genetic variation in lipid metabolism

2010 ◽  
Vol 151 (34) ◽  
pp. 1376-1383 ◽  
Author(s):  
Mariann Harangi ◽  
István Balogh ◽  
János Harangi ◽  
György Paragh
Keyword(s):  
Genetic Variation ◽  
Lipid Metabolism ◽  
Genetic Background ◽  
Cholesterol Absorption ◽  
Niemann Pick

A Niemann–Pick C1-like-1 egy szterolfelismerő domént tartalmazó membránfehérje, amelyet nagy számban expresszálnak csúcsi felszínükön a bélhámsejtek. Az utóbbi évek vizsgálatai azt igazolták, hogy ez a fehérje szükséges a szabad koleszterin bejutásához a bélhámsejtekbe a bél lumenéből. Biokémiai vizsgálatok azt igazolták, hogy a Niemann–Pick C1-like-1-hez kötődik az ezetimib, amely egy hatékony koleszterinfelszívódást gátló szer. A bélből történő koleszterinfelszívódás ütemében és az ezetimibkezelés hatékonyságában tapasztalt egyéni eltérések hátterében felmerült néhány Niemann–Pick C1-like-1 génvariáció oki szerepe.

Variation in the morphology and flowering time of cluster clover (Trifolium glomeratum L.) and its relationship to distribution in southern Australia

1995 ◽  
Vol 46 (5) ◽  
pp. 1027 ◽  
Author(s):  
FP Smith ◽  
PS Cocks ◽  
MA Ewing
Keyword(s):  
Genetic Variation ◽  
Flowering Time ◽  
Seed Mass ◽  
Annual Rainfall ◽  
Strongly Correlated ◽  
Summer Maximum ◽  
Maximum Temperatures ◽  
Pattern Of Variation ◽  
Growth Habits

Cluster clover is a widely distributed and ecologically successful introduced legume in southern Australia. In an attempt to understand the role of genetic variation in this success, morphological and physiological traits were measured in 94 accessions from southern Australia and 6 from the Mediterranean basin. Flowering time ranged from 105 to 185 days after sowing, but was not strongly correlated with annual rainfall or length of growing season at the site of collection. Variation in other traits partitioned the populations into two morphs which, apart from flowering time and leaf marker, were largely homogeneous. The morphs differed significantly in floret number per inflorescence (22 v. 32-37) and seed mass (379 8g v. 523 8g), had different growth habits and strong within-morph associations between leaf markers and stipule and petal coloration. The morphs differed in their distributions within southern Australia and the pattern of distribution was related to summer maximum temperatures, winter minimum temperatures and spring rainfall. These results demonstrate that genetic variation has been important to the success of cluster clover and suggests that the variation is organized. The pattern of variation observed and its relationship to ecogeography is consistent with findings for other highly inbreeding species. A map of the species distribution in Western Australia is presented.

Influence de la densité du couvert forestier sur le développement architectural de jeunes chênes sessiles, Quercus petraea (Matt.) Liebl. (Fagaceae), en régénération forestière

2000 ◽  
Vol 78 (12) ◽  
pp. 1531-1544 ◽  
Author(s):  
Eric Nicolini ◽  
Daniel Barthélémy ◽  
Patrick Heuret
Keyword(s):  
Quercus Petraea ◽  
Growth Unit ◽  
Growth Morphology ◽  
Basal Diameter ◽  
Canopy Density ◽  
Sessile Oak ◽  
The North ◽  
Oak Trees ◽  
Branching Patterns ◽  
Number Of Branches

The growth and branching patterns of the main axis of 6-year-old sessile oak, growing in a natural regeneration in the north of France, were analysed each year retrospectively according to three increasing canopy density conditions: large gap, small gap, and dense canopy. Increasing gap size is associated with an increase in the total height, basal diameter, branching probability, and global polycyclism rate of the trees. At the growth unit or annual shoot level, from dense canopy to large gaps these botanical entities also show an increase in their total length, number of nodes, polycyclism, and branching rate as well as mean number of branches and mean internode length. A discussion of our results revealed some endogenous features of growth and branching patterns in young sessile oak trees. It is also shown that increasing canopy density generally tends to reduce the expression of the endogenous architectural sequence of differentiation of young sessile oak trees. Young trees growing below dense canopy thus seem to be "delayed" in their sequence of differentiation and appear to be in a "waiting" status, whereas young trees growing in large gaps exhibit an architecture very similar to trees growing in nurseries under nonlimiting growth conditions.Key words: architecture, Quercus petraea, growth, morphology, canopy density.

Genetic Variation of Serotonin Function and Cognitive Control

2007 ◽  
Vol 19 (12) ◽  
pp. 1923-1931 ◽  
Author(s):  
Alexander Strobel ◽  
Gesine Dreisbach ◽  
Johannes Müller ◽  
Thomas Goschke ◽  
Burkhard Brocke ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Cognitive Control ◽  
Personality Traits ◽  
Anxiety And Depression ◽  
Continuous Performance ◽  
Continuous Performance Task ◽  
Performance Task ◽  
The Impact ◽  
Related Personality

Although it is widely accepted that serotonin plays a pivotal role in the modulation of anxiety- and depression-related personality traits as well as in the pathogenesis of anxiety disorders and depression, the role of serotonin in cognition is less clear. In the present study, we investigated the involvement of serotonin in cognitive behaviors by examining the impact of genetic variation in key regulators of serotonergic neurotransmission on behavioral measures in a cognitive control task. Eighty-five healthy participants performed a cued continuous performance task (the AX Continuous Performance Task [AXCPT]) and were genotyped for polymorphisms in the transcriptional control regions of the tryptophan hydroxylase 2 gene (TPH2 G-703T; rs4570625) and the serotonin transporter gene (5-HTTLPR). The core result was that individuals lacking the rare TPH2 T allele were not faster than T allele carriers, but committed fewer errors and were less variable in responding. These findings parallel those of a recent study where an enhancement of executive control in individuals without the rare TPH2 T/T genotype was observed. Together with recent evidence that individuals without the T allele exhibit higher scores in anxiety- and depression-related personality traits, our results underscore the role of the TPH2 G-703T polymorphism in the modulation of behavior and raise the intriguing possibility that genetic variants associated with higher negative emotionality may have beneficial effects on some cognitive functions.

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