12 research outputs found

    Radiocarbon investigation of the Superlative African Baobabs from Savé Valley Conservancy, Zimbabwe

    Get PDF
    Author Posting. © Studia Chemia, 2019. Studia Universitatis Babes-Bolyai Seria Chemia is an Open Access Journal (read, download, copy, distribute, print for research use, search, or link to the full texts of articles). The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia , 64(2), Tom II, (2019): 411-419, doi:10.24193/subbchem.2019.2.35.The article reports the radiocarbon investigation results of the superlative African baobabs from Savé Valley, Zimbabwe. Several wood samples collected from these baobab were analysed by AMS (accelerator mass spectrometry) radiocarbon dating. The radiocarbon dates of the oldest samples were 1529 ± 14 BP for Matendere Big baobab, 1179 ± 19 BP for Chishakwe Big tree and 1096 ± 35 BP for Mokore Giant baobab. The corresponding calibrated ages are 1430 ± 15, 1090 ± 40 and 1020 ± 25 calendar yr. The oldest tree from Savé Valley, which we described previously, is the Humani Bedford Old baobab. The radiocarbon date of its oldest sample, 1655 ± 14 BP, corresponds to a calibrated age of 1580 ± 30 calendar yr.Authors would like to acknowledge Léon and Judy Duplessis, the owners of the Matendere Rach, Lisa-Jane Campbell of Chishakwe Ranch, Roger Whittall, the owner of the Humani Ranch and his wife Anne Whittall, Greg and Melanie Duckworth of Mokore Ranch for granting access in the ranches and for authorising the investigation and sampling of the monumental baobabs. The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2016-0776, Nr. 90/2017

    Radiocarbon dating of a very large African baobab from Limpopo, South Africa : investigation of the Sagole Big Tree

    Get PDF
    Author Posting. © Studia Chemia, 2017. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 62, no. 2, Tom 2 (2017): 355-364, doi:10.24193/subbchem.2017.2.28.The article reports the AMS (accelerator mass spectrometry) radiocarbon dating results of Sagole Big tree, a giant African baobab from Limpopo, South Africa. Several wood samples were collected from the walls of its inner cavity and dated by radiocarbon. The age values along the cavity samples increase with the distance into the wood. This anomaly shows that the cavity is a false one. The oldest sample segment had a radiocarbon date of 781 ± 29 BP, which corresponds to a calibrated age of 740 ± 15 yr. We estimate that the oldest part of the Sagole baobab has an age of 800-900 yr. We determined that the tree has a closed ring-shaped structure, which consists of a large unit with six fused stems and of two additional leaning stems.The research was funded by the Romanian Ministry of Scientific Research CNCSUEFISCDI under grant PN-II-ID-PCE-2013-76

    Radiocarbon dating of a very old African baobab from Savé Valley, Zimbabwe

    Get PDF
    Author Posting. © Studia Chemia, 2016. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Chemia 2016, no. 4 (2016): 7-20.The article reports the radiocarbon investigation results of the Humani Bedford baobab, an old African baobab from Savé Valley, Zimbabwe. Two wood samples were collected from the large inner cavity. Several segments were extracted from these samples and analysed by AMS (accelerator mass spectrometry) radiocarbon dating. We found that the age values of segments increase with the distance into the wood. This major anomaly is characteristic to multi-stemmed baobabs with a closed ring-shaped structure and a false cavity inside. The investigation of the Humani Bedford baobab evinced that the baobab consists of three fused stems. The fourth stem of the ring is missing. The oldest dated segment was found to have a radiocarbon date of 1655 ± 14 BP, which corresponds to a calibrated age of 1575 ± 30 yr. The dating results show that the stems which build the ring stopped growing toward the false cavity more than 600 yr ago. By considering the position of the oldest segment in the investigated stem, we concluded that the Humani Bedford baobab is around 1800 yr old. According to our dating results, the Humani Bedford baobab becomes the oldest living African baobab.The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76

    Age and growth rate dynamics of an old African baobab determined by radiocarbon dating

    Get PDF
    Author Posting. © Arizona Board of Regents on behalf of the University of Arizona, 2010. This article is posted here by permission of Dept. of Geosciences, University of Arizona for personal use, not for redistribution. The definitive version was published in Radiocarbon 52 (2010): 727-734.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.This material is based on work supported by a grant from the Romanian National University Research Council (PN II - IDEI 2354 Nr. 1092) and by US National Science Foundation under Cooperative Agreement OCE-022828996

    Radiocarbon investigation of the pedunculate oak of Botosana, Romania

    Get PDF
    Author Posting. © Studia Chemia, 2018. Studia Universitatis Babes-Bolyai Chemia is an Open Access Journal (read, download, copy, distribute, print for research use, search, or link to the full texts of articles). The definitive version was published in Studia Universitatis Babes-Bolyai Chemia 63(4), (2018): 7-13, doi: 10.24193/subbchem.2018.4.01.The article discloses the AMS (accelerator mass spectrometry) radiocarbon dating results of the pedunculate oak of BotoƟana. Four wood samples were extracted from its trunk. Five segments extracted from these samples were analyzed by AMS radiocarbon. Their radiocarbon dates were found to be between 161 ± 21 BP and 260 ± 20 BP. These values correspond to calibrated ages of 235 – 365 years. The dating results extrapolated to the geometric center of the trunk indicate an age of 645 ± 50 years for the oak of BotoƟana.The research was funded by the Romanian Ministry of Research and Innovation CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2016-0776, Nr. 90/2017

    Radiocarbon dating of African baobabs with two false cavities : the investigation of Luna tree

    Get PDF
    The paper discloses the radiocarbon investigation results of the Luna tree, a representative African baobab from Venetia Limpopo Nature Reserve, South Africa. Several wood samples collected from deep incisions in the trunk were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. The age sequence of segments extracted from the oldest sample demonstrates that ages increase with the distance into the wood up to a point of maximum age, after which ages decrease toward the sample end. This anomaly is typical for multi-stemmed baobabs, having a closed ring-shaped structure with a false cavity inside. Dating results reveal that each of the two large fused units, which build the Luna tree, consist of such a closed ring. The two closed rings include two interconnected false inner cavities. False cavities are empty spaces between fused stems that were never filled with wood. We named this baobab architecture, which has a very high symmetry, double closed ring-shaped structure with two false cavities. The new architecture, which is very uncommon, enables baobabs to reach large sizes and very old ages. The radiocarbon date of the oldest sample segment was 1507 ± 22 BP, which corresponds to a calibrated age of 1405 ± 20 yr. We estimate that the oldest part of Luna tree has an age of 1600 ± 100 yr. By these results, the Luna tree becomes the fourth oldest African baobab with accurate dating results.The Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-IIID- PCE-2013-76.http://chem.ubbcluj.ro/~studiachemiaam2016Mammal Research InstituteZoology and Entomolog

    Tuberculosis impacts multiple aspects in quality of life in a Romanian cohort of drug‐susceptible and drug resistant patients: A patient‐reported outcome measures study

    Get PDF
    Background: Tuberculosis (TB), and especially its drug resistant forms, is responsible for not only significant mortality, but also considerable morbidity, still under‐quantified. This study used four Patient‐Reported Outcome Measures (PROMS) to assess the status of persons affected by drug‐susceptible and drug‐resistant TB during their TB treatment or after treatment completion, in Romania, the highest TB burden country in the EU. Methods: People affected by TB in two different regions in Romania were included during and after treatment, following a cross‐sectional design. PROMs used were SF‐36, EQ‐5D‐5L, WPAI and the app‐based audiometry screening tool ‘uHear.’ Descriptive statistics and relevant statistical tests were used to compare groups between themselves and with the general Romanian population. Results: Both patients with drug‐susceptible and drug‐resistant TB experience, with drug‐resistant patients experiencing statistically significantly more pain and hearing loss. PROMs show some improvement in the after‐treatment group; however, compared with the general Romanian population for which data were available, all groups scored lower on all outcome measures. Conclusion: PROMs offer the possibility of obtaining a more comprehensive view of patients' status, by involving them directly in the medical process and could guide a rehabilitation strategy

    The growth stop phenomenon of baobabs (Adansonia spp.) identified by radiocarbon dating

    Get PDF
    The article reports the growth stop phenomenon, which was documented only for baobabs, i.e. for trees belonging to the Adansonia genus. The identification of growth stop was enabled by radiocarbon dating, which allows a complex investigation of samples collected from the trunk/stems of baobabs. In several cases, the outermost rings of baobabs, which were close to the bark, were found to be old, with ages of several hundreds of years, instead of being very young. Dating results of samples collected from six baobabs are presented. For multistemmed baobabs, the growth stop may occur only for one or several stems. We identified four factors that may induce the growth stop: (i) stress determined by severe climate conditions, (ii) old age, (iii) the need to keep a stable internal architecture, and (iv) the collapse of stems that survive this trauma. Baobabs and their stems affected by growth stop may survive for several centuries, by continuing to produce leaves, flowers, and fruits. This phenomenon was associated with the capacity of baobabs to store large amounts of water in their trunks/stems in the rainy season. This reservoir of water is used during the dry season and allows the trees to survive prolonged drought periods.Selected papers from the 2015 Radiocarbon Conference, Dakar, Senegal, 16–20 November 2015https://www.cambridge.org/core/journals/radiocarbonhj2018Mammal Research Institut

    Ammonium salts of organophosphorus acids. Crystal and molecular structure of [Et3NH]+[(SPMe2)(SPPh2)N]- and [2-(O(CH2CH2)2N(H)CH2)C6H4]+[S2P(OPri)2]-

    Get PDF
    8 påginas, 4 figuras, 2 tablas, 1 esquema.The ammonium salts [Et3NH]+L- {L- = [(SPMe2)(SPPh2)N]- (1), Ph2PS2 - (2)} were obtained in the reaction between triethylamine and the corresponding organophosphorus acid in a 1:1 molar ratio, while [2-{O(CH2CH2)2N(H)CH2}C6H4]+[S2P(OPri)2]- (3) resulted as hydrolysis product in the process of growing crystals of [2-{O(CH2CH2)2N(H)CH2}C6H4SeS2P(OPri)2. Compounds 1 and 2 were characterized by 1H and 31P NMR spectroscopy. Single-crystal X-ray diffraction studies revealed the presence of short intermolecular S···H contacts which result in the formation of dimeric units in 1 and of a layered supramolecular structure in 3.This work was supported by the National University Research Council of Romania (CNCSIS, Research Project No. ID-2404/2008). A. M. P. thanks the European Social Fund for a Scholarship (Education and Training Program 2008-2013, POSDRU/6/1.5/S/3).Peer reviewe
    corecore