scholarly journals The Habitat of the Neglected Independent Protonemal Stage of Buxbaumia viridis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 83
Author(s):  
Ameline Guillet ◽  
Vincent Hugonnot ◽  
Florine Pépin
Keyword(s):  
Species Range ◽  
Coniferous Forests ◽  
Decayed Wood ◽  
Explanatory Variables ◽  
Ecological Requirements ◽  
Recent Advances ◽  
Sporophyte Development

Buxbaumia viridis is a well-known species of decaying deadwood, which is protected in Europe. All previous studies dealing with the ecology of B. viridis rely on the sporophyte generation because the gametophyte generation is allegedly undetectable. Recent advances have shown that the protonemal stage, including gemmae, is recognizable in the field, thereby considerably modifying our perception of the species’ range and habitat. In France, we demonstrate the existence of independent protonemal populations, with the implication that the range of B. viridis is widely underestimated. Sporophytes and sterile protonema do not share the same ecological requirements. The sporophyte stage was found in montane zones, almost exclusively in coniferous forests, and on well-decayed wood. The sterile protonemal stage extends to lower elevations, in broad-leaved forests, and on wood in a less advanced state of decay. Our results suggest that the humidity could be one of the most relevant explanatory variables for the occurrence of sporophytes. Opening of the canopy seems to promote sporophyte development. Previous anomalous observations of B. viridis growing on humus or bark might be explained by the presence of a protonemal population that is able to produce sporophytes under rarely occurring but favorable climatic events.

scholarly journals Succession of ground beetle (Coleoptera: Carabidae) communities after windthrow disturbance in a montane Norway spruce forest in the Hrubý Jeseník Mts. (Czech Republic)

2017 ◽  
Vol 63 (4) ◽  
pp. 180-187 ◽  
Author(s):  
Josef Kašák ◽  
Jiří Foit ◽  
Marek Hučín
Keyword(s):  
Czech Republic ◽  
Norway Spruce ◽  
Ground Beetle ◽  
Ground Beetles ◽  
Coniferous Forests ◽  
Stand Age ◽  
Forest Species ◽  
Relict Species ◽  
Ecological Requirements ◽  
Intensively Managed

Abstract Wind disturbances are a key factor that is significantly involved in the life cycle of natural boreomontane coniferous forests. As most of these forests are currently intensively managed, we have limited knowledge on succession following natural disturbance. Succession in a Norway spruce stand after a windthrow event was studied using ground beetles as model bioindication taxa in the Hrubý Jeseník Mts. (Czech Republic). The study documented that the composition of ground beetle communities was significantly associated with stand age and its microclimatic parameters (particularly the minimal temperature and average and minimal humidity). Forest species including prey specialists, hygrophilous species, as well as habitat generalists were the most abundant in the mature stand, where the forest had the highest humidity and the least profound minimal temperatures. In contrast, open-habitat species, including euryoecious species and relict species of higher elevations, reached their highest abundances in clearing shortly after the windthrow. In clearing the humidity was lower and the temperature fluctuated significantly (the lowest minimal temperatures). Ground beetles, including forest species, were the least abundant in young stands (10 and 20 years after windthrow). We conclude that old stands are of particular importance because they harbour the highest abundance and diversity of ground beetles with various ecological requirements. Natural wind disturbances are important as well since they increase diversity by enabling the occurrence of many non-forest species. Hence, a mosaic of stands of different ages with a sufficient proportion of old stands should be maintained when managing montane coniferous forests.

Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Dispersion ◽  
Photographic Material ◽  
Recent Advances ◽  
Metal Abundances ◽  
Ccd Detectors ◽  
Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

Chelation-assisted transition metal-catalysed C–H chalcogenylations

2020 ◽  
Vol 7 (8) ◽  
pp. 1022-1060 ◽  
Author(s):  
Wenbo Ma ◽  
Nikolaos Kaplaneris ◽  
Xinyue Fang ◽  
Linghui Gu ◽  
Ruhuai Mei ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Advances ◽  
Site Selectivity ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

Nucleosome dynamics

2006 ◽  
Vol 73 ◽  
pp. 109-119 ◽  
Author(s):  
Chris Stockdale ◽  
Michael Bruno ◽  
Helder Ferreira ◽  
Elisa Garcia-Wilson ◽  
Nicola Wiechens ◽  
...  
Keyword(s):  
High Resolution ◽  
Chromatin Structure ◽  
Current Knowledge ◽  
Dynamic Properties ◽  
Structure And Dynamics ◽  
Nucleosome Dynamics ◽  
Sharp Focus ◽  
Recent Advances ◽  
Insight Into ◽  
Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

Recent Advances in the Treatment of Pulmonary Tuberculosis

1950 ◽  
Vol 34 (5) ◽  
pp. 1363-1380
Author(s):  
Theodore L. Badger ◽  
William E. Patton
Keyword(s):  
Pulmonary Tuberculosis ◽  
Recent Advances

Recent Advances in Thyroid Imaging

1990 ◽  
Vol 23 (2) ◽  
pp. 251-270
Author(s):  
Martin P. Sandler, MD ◽  
James A. Patton ◽  
Robert H. Ossoff
Keyword(s):  
Thyroid Imaging ◽  
Recent Advances

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.

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