scholarly journals Age and architecture of the largest African Baobabs from Mayotte, France

2020 ◽  
Vol 1 (1) ◽  
pp. 33-47 ◽  
Author(s):  
Adrian Patrut ◽  
Roxana T. Patrut ◽  
Laszlo Rakosy ◽  
Karl F. Von Reden
Keyword(s):  
Radiocarbon Dating ◽  
Cluster Structure ◽  
Radiocarbon Date ◽  
General State ◽  
Adansonia Digitata ◽  
Open Ring ◽  
The Indian Ocean ◽  
Paleoclimate Reconstructions ◽  
Ring Shaped Structure ◽  
Comoro Islands

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. Baobabs constitute a reliable archive for climate change and millennial specimens were recently used as proxies for paleoclimate reconstructions in southern Africa. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, corresponding to a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

Age and architecture of the largest African Baobabs from Mayotte, France

2020 ◽  
Author(s):  
Adrian Patrut ◽  
Roxana Patrut ◽  
Laszlo Rakosy ◽  
Karl von Reden
Keyword(s):  
Life Cycle ◽  
Radiocarbon Dating ◽  
Cluster Structure ◽  
Radiocarbon Date ◽  
General State ◽  
Adansonia Digitata ◽  
Open Ring ◽  
The Indian Ocean ◽  
Ring Shaped Structure ◽  
Comoro Islands

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, which translates into a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

scholarly journals Age, Growth and Death of a National Icon: The Historic Chapman Baobab of Botswana

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 983 ◽  
Author(s):  
Adrian Patrut ◽  
Stephan Woodborne ◽  
Roxana T. Patrut ◽  
Grant Hall ◽  
Laszlo Rakosy ◽  
...  
Keyword(s):  
Growth Rate ◽  
Radiocarbon Dating ◽  
Radiocarbon Date ◽  
Rate Variation ◽  
The Past ◽  
Open Ring ◽  
Climate Evolution ◽  
National Icon ◽  
Ring Shaped Structure ◽  
Past 1000 Years

The year 2016 witnessed the fall of a symbol of the botanical world: the historic Chapman baobab of Botswana. This article presents the results of our investigation of the standing and fallen tree. The Chapman baobab had an open ring-shaped structure composed of six partially fused stems. Several wood samples collected from the stems prior and after their collapse were analysed by using radiocarbon dating. The radiocarbon date of the oldest sample was 1381 ± 22 BP, which corresponds to a calibrated age of 1345 (+10, −15) calendar years. The dating results show that the six stems of the Chapman baobab belonged to three different generations, which were 1350–1400, 800–1000 and 500–600 years old. The growth rate variation of the largest and oldest stem is presented and correlated with the climate evolution in the area over the past 1000 years. The factors that determined the sudden fall and death of the Chapman baobab are also presented and discussed.

scholarly journals The γTuRC Revisited: A Comparative Analysis of Interphase and Mitotic Human γTuRC Redefines the Set of Core Components and Identifies the Novel Subunit GCP8

2010 ◽  
Vol 21 (22) ◽  
pp. 3963-3972 ◽  
Author(s):  
Neus Teixidó-Travesa ◽  
Judit Villén ◽  
Cristina Lacasa ◽  
Maria Teresa Bertran ◽  
Marco Archinti ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Comparative Analysis ◽  
Protein Complex ◽  
The Novel ◽  
Microtubule Network ◽  
Microtubule Polymerization ◽  
Open Ring ◽  
Core Components ◽  
Ring Complexes ◽  
Ring Shaped Structure

The γ-tubulin complex is a multi-subunit protein complex that nucleates microtubule polymerization. γ-Tubulin complexes are present in all eukaryotes, but size and subunit composition vary. In Drosophila, Xenopus, and humans large γ-tubulin ring complexes (γTuRCs) have been described, which have a characteristic open ring-shaped structure and are composed of a similar set of subunits, named γ-tubulin, GCPs 2-6, and GCP-WD in humans. Despite the identification of these proteins, γTuRC function and regulation remain poorly understood. Here we establish a new method for the purification of native human γTuRC. Using mass spectrometry of whole protein mixtures we compared the composition of γTuRCs from nonsynchronized and mitotic human cells. Based on our analysis we can define core subunits as well as more transient interactors such as the augmin complex, which associates specifically with mitotic γTuRCs. We also identified GCP8/MOZART2 as a novel core subunit that is present in both interphase and mitotic γTuRCs. GCP8 depletion does not affect γTuRC assembly but interferes with γTuRC recruitment and microtubule nucleation at interphase centrosomes without disrupting general centrosome structure. GCP8-depleted cells do not display any obvious mitotic defects, suggesting that GCP8 specifically affects the organization of the interphase microtubule network.

scholarly journals Combining Ancient DNA and Radiocarbon Dating Data to Increase Chronological Precision

2020 ◽  
Author(s):  
Jakob W. Sedig ◽  
Iñigo Olade ◽  
Nick Patterson ◽  
David Reich
Keyword(s):  
Ancient Dna ◽  
Radiocarbon Dating ◽  
Dna Analysis ◽  
Human Reproduction ◽  
Radiocarbon Date ◽  
The Past ◽  
Ancient Dna Analysis ◽  
Related Individuals ◽  
Adna Analysis

AbstractThis paper examines how ancient DNA data can enhance radiocarbon dating. Because there is a limit to the number of years that can separate the dates of death of related individuals, the ability to identify first-, second-, and third-degree relatives through aDNA analysis can serve as a constraint on radiocarbon date range estimates. To determine the number of years that can separate related individuals, we modeled maximums derived from biological extremes of human reproduction and death ages and compiled data from historic and genealogical death records. We used these estimates to evaluate the date ranges of a global dataset of individuals that have been radiocarbon dated and for which ancient DNA analysis identified at least one relative. We found that many of these individuals could have their date ranges reduced by building in date of death separation constraints. We examined possible reasons for date discrepancies of related individuals, such as dating of different skeletal elements or wiggles in the radiocarbon curve. Our research demonstrates that when combined, radiocarbon dating and ancient DNA analysis can provide a refined and richer view of the past.

scholarly journals Supplemental Material: A 1000-yr-old tsunami in the Indian Ocean points to greater risk for East Africa

2020 ◽  
Author(s):  
Vittorio Maselli
Keyword(s):  
Grain Size ◽  
Indian Ocean ◽  
Radiocarbon Dating ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Tsunami Modeling ◽  
Additional Information ◽  
The Indian Ocean ◽  
2004 Tsunami ◽  
Area Section

Additional information on the study area (Section S1), radiocarbon dating of the samples (Section S2), grain size analysis (Section S3), paleoenvironmental reconstructions (Section S4), tsunami modeling (Section S5), and eyewitnesses of the 2004 tsunami in Pangani (Section S6), and the Ethics statement (Section S7).<br>

scholarly journals Descriptive skeletal anatomy of Blommersia transmarina (Amphibia: Anura: Mantellidae) from the Comoro Islands

2019 ◽  
Vol 89 (1) ◽  
pp. 14-73 ◽  
Author(s):  
Javier H. Santos-Santos ◽  
Mireia Guinovart-Castán ◽  
David R. Vieites
Keyword(s):  
Phenotypic Variation ◽  
Morphological Analysis ◽  
Vomeronasal Organ ◽  
Species Dispersal ◽  
Geographic Ranges ◽  
Novel Structure ◽  
Internal Structures ◽  
The Indian Ocean ◽  
Non Destructive ◽  
Comoro Islands

Mantellid frogs present an extensive adaptive radiation endemic to Madagascar and Comoros, being the subfamily Mantellinae the most morphologically and ecologically diverse. The Mantellinae present key innovative evolutionary traits linked to their unique reproductive behavior, including the presence of femoral glands and a derived vomeronasal organ. In addition, previous studies pointed to size differentiation in playing an important role in species’ dispersal capacities and shaping of their geographic ranges. Despite the high phenotypic variation observed in this clade, to date an exhaustive morphological analysis of their anatomy has still not been performed, much less in relation to internal structures. Here, we present a comprehensive skeletal description of a mantellid species, Blommersia transmarina, from the island of Mayotte in the Indian Ocean, which has potentially undergone a process of moderate gigantism compared to other Blommersia species. We describe its intraspecific skeletal variation utilizing non-destructive volume renderings from μCT-scans, and characterize the presence of sexual dimorphism and size covariation in skeletal structures. Notably, we found numerous signs of hyperossification, a novel structure for mantellids: the clavicular process, and the presence of several appendicular sesamoids. Our findings suggest that skeletal phenotypic variation in this genus may be linked to biomechanical function for reproduction and locomotion.

scholarly journals Fire History of a Giant African Baobab Evinced by Radiocarbon Dating

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 717-726 ◽  
Author(s):  
Adrian Patrut ◽  
Diana H Mayne ◽  
Karl F von Reden ◽  
Daniel A Lowy ◽  
Robert van Pelt ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
South Africa ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Fire History ◽  
Adansonia Digitata ◽  
Entire Area ◽  
History Of

The article reports the first radiocarbon dating of a live African baobab (Adansonia digitata L.), by investigating wood samples collected from 2 inner cavities of the very large 2-stemmed Platland tree of South Africa. Some 16 segments extracted from determined positions of the samples, which correspond to a depth of up to 15–20 cm in the wood, were processed and analyzed by accelerator mass spectrometry (AMS). Calibrated ages of segments are not correlated with their positions in the stems of the tree. Dating results indicate that the segments originate from new growth layers, with a thickness of several centimeters, which cover the original old wood. Four new growth layers were dated before the reference year AD 1950 and 2 layers were dated post-AD 1950, in the post-bomb period. Formation of these layers was triggered by major damage inside the cavities. Fire episodes are the only possible explanation for such successive major wounds over large areas or over the entire area of the inner cavities of the Platland tree, able to trigger regrowth.

scholarly journals Age and Growth Rate Dynamics of an Old African Baobab Determined by Radiocarbon Dating

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 727-734 ◽  
Author(s):  
Adrian Patrut ◽  
Diana H Mayne ◽  
Karl F von Reden ◽  
Daniel A Lowy ◽  
Sarah Venter ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Growth Rate ◽  
Radiocarbon Dating ◽  
Age And Growth ◽  
Sectional Area ◽  
Adansonia Digitata ◽  
Cross Sectional ◽  
Volume Increase ◽  
The Past ◽  
Area Increase

In 2008, a large African baobab (Adansonia digitata L.) from Makulu Makete, South Africa, split vertically into 2 sections, revealing a large enclosed cavity. Several wood samples collected from the cavity were processed and radiocarbon dated by accelerator mass spectrometry (AMS) for determining the age and growth rate dynamics of the tree. The 14C date of the oldest sample was found to be of 1016 ± 22 BP, which corresponds to a calibrated age of 1000 ± 15 yr. Thus, the Makulu Makete tree, which eventually collapsed to the ground and died, becomes the second oldest African baobab dated accurately to at least 1000 yr. The conventional growth rate of the trunk, estimated by the radial increase, declined gradually over its life cycle. However, the growth rate expressed more adequately by the cross-sectional area increase and by the volume increase accelerated up to the age of 650 yr and remained almost constant over the past 450 yr.

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