scholarly journals Past rainfall and trace element variations in a tropical speleothem from India

MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 307-316
Author(s):  
M. G. YADAVA ◽  
R. RAMESH

An actively growing stalagmite (cave deposit) was collected in 1996 from the Dandak cave in Madhya Pradesh. Trace elements Mg, Sr and Ba were measured in order to asses their palaeoclimatic significance. More than 100% variations in the concentrations of trace elements have been observed during the growth period. The chemical and physical properties of the trace elements along with the data of stable isotope ratios of exygen and carbon from our earlier work has been discussed in this paper. Ratio of Ba to Sr concentrations has remained constant suggesting that the soil layers and bedrock dissolution have contributed the same proporation of trace elements to the cave seepage water. Slowly varying components in the Mg, Sr and Ba concentrations and profiles show high degrees of correlations. It is found that changes in the trace elements are mainly driven by the varying intensity of past rainfall. Trace element variations of speleothems in tropical regions can be used as indicators of the past rainfall intensities. Different climatic intervals are characterised based on trace elements and stable isotoes. Period 3700 to 3350 yr BP was found to be arid. High rainfall was observed between 3350 to 3200 yr BP. After a hiatus period of 2000 yr due to non-climate dependent proceses, again a high rainfall phase between 1200 to 400 yr BP was observed with a peak level at ~200 yr BP and a short arid phase at ~90 yr BP was also observed.

2019 ◽  
Vol 446 (1-2) ◽  
pp. 543-561 ◽  
Author(s):  
Camilla Ruø Rasmussen ◽  
Kristian Thorup-Kristensen ◽  
Dorte Bodin Dresbøll

Abstract Aims We tested if chicory acquires nutrients from soil layers down to 3.5 m depth and whether the deep nutrient uptake increases as a result of drought or intercropping with ryegrass and black medic. We also tested whether application of the trace elements Cs, Li, Rb, Sr and Se, as tracers, result in similar uptake rates. Methods The methodological tests were carried out in a pilot experiment where the tracers were applied to 1 m depth in lucerne and red beet grown in tube rhizotrons. The dynamics of deep nutrient uptake in chicory was studied in large 4 m deep rhizoboxes. A drought was induced when roots had reached around 2 m depth. Results Chicory acquired 15N from 3.5 m depth and trace element tracers from 2.3 m depth. We found no compensatory tracer uptake with depth during drought. We found some indications of a compensatory tracer uptake from 2.3 and 2.9 m depth in intercropped chicory. Application of equimolar amounts of trace elements resulted in similar excess tracer concentrations within species. Conclusion Chicory demonstrates nutrient uptake from below 3 m but does not increase deep nutrient uptake as a response to limited topsoil nutrient availability induced by drought or intercropping.


Author(s):  
N.A. Cullen

During the past six years trials have been carried out at Invermay Research Station with the trace elements molybdenum, vanadium, boron, copper and cobalt.


2014 ◽  
Vol 8 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Emmanuel Wafo ◽  
Véronique Risoul ◽  
Thérèse Schembri ◽  
Véronique Lagadec ◽  
Frank Dhermain ◽  
...  

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast. The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle). Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant. The correlations between the concentrations of trace elements suggest the existence of detoxification processes. Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.


2020 ◽  
Vol 18 (1) ◽  
pp. 77-96
Author(s):  
Hameed Alsamadany ◽  
Hassan S. Al-Zahrani ◽  
El-Metwally M. Selim ◽  
Mohsen M. El-Sherbiny

AbstractTo assess trace element concentrations (Zn, Cu, Pb, Cr, Cd and Ni) in the mangrove swamps along the Saudi coast of the Arabian Gulf, thirteen samples of surface sediment and leaves of grey mangrove, Avicennia marina were collected and analyzed. The detected trace element contents (μg g-1) in surface sediments were in the following descending order according to their mean values; Cr (49.18) > Zn (48.48) > Cu (43.06) > Pb (26.61) > Ni (22.88) > Cd (3.21). The results showed that the average concentrations of Cd and Pb exceeded their world average concentration of shale. The geo-accumulation, potential ecological risk and toxicity response indices demonstrated that trace elements have posed a considerable ecological risk, especially Cd. The inter-relationships between physico-chemical characters and trace elements suggests that grained particles of mud represent a noteworthy character in the distribution of trace elements compared to organic materials. Moreover, the results revealed that Zn was clearly bioaccumulated in leaf tissues A. marina. Dredging, landfilling, sewage effluents and oil pollution can be the paramount sources of pollution in the area under investigation.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Prince Oteng ◽  
John K. Otchere ◽  
Stephen Adusei ◽  
Richard Q. Mensah ◽  
Emmanuel Tei-Mensah

Tetrapleura tetraptera is widely cherished in African traditional homes because of its alleged therapeutic and nutritional properties. This present study aimed at determining the levels of vitamin A, C, E, and beta-carotene and trace element (Fe, Cu, Mn, Co, Se, and Zn) concentrations and their extractabilities in the pulp, seeds, and whole fruit (mixture of pulp and seeds) of T. tetraptera. The total trace element concentration of Fe, Cu, Co, Mn, and Zn and their extractabilities (%) were determined using flame atomic absorption spectrometer (FAAS), whereas UV-VIS spectrophotometer was used to determine selenium concentration. The trace element content (mg/kg) based on dry weight in the pulp, seeds, and whole fruit was Fe (162.00 ± 7.14, 115.00 ± 12.00, and 154.00 ± 25.20, respectively), Zn (31.60 ± 4.77, 43.40 ± 5.29, and 41.50 ± 8.97, respectively), Cu (16.10 ± 4.98, 11.90 ± 8.40, and 17.20 ± 14.50, respectively), Mn (55.30 ± 2.41, 156.00 ± 10.20, and 122.00 ± 5.29, respectively), Co (38.10 ± 6.40, 21.10 ± 7.15, and 44.00 ± 14.90, respectively), and Se (1.49 ± 0.17, 2.43 ± 0.28, and 2.97 ± 0.27 μg/g, respectively). The mineral extractabilities (%) in the pulp, seeds, and whole fruit of T. tetraptera were established to be in the order Co > Zn > Fe > Cu > Se > Mn. Also, the chromatographic method (HPLC) was used to evaluate vitamin E concentration, and vitamin C and concentration of beta-carotene were calculated from the obtained concentration of vitamin A using a conversion factor by the titrimetric method. From the results of vitamin analysis, a significant difference (p<0.05) was observed among the pulp, seeds, and whole fruit for vitamin C and E. However, no significant difference (p>0.05) was perceived among these plant parts for vitamin A and beta-carotene. This study has therefore revealed that the pulp, seeds, and whole fruit of T. tetraptera contain varying concentrations of vitamins and trace elements and has given many vital insights on which part of T. tetraptera to consume, as concentrations of these nutrients differ in the discrete parts of the fruit.


2011 ◽  
Vol 286 (27) ◽  
pp. 23623-23629 ◽  
Author(s):  
Yan Zhang ◽  
Vadim N. Gladyshev

Biological trace elements are needed in small quantities but are used by all living organisms. A growing list of trace element-dependent proteins and trace element utilization pathways highlights the importance of these elements for life. In this minireview, we focus on recent advances in comparative genomics of trace elements and explore the evolutionary dynamics of the dependence of user proteins on these elements. Many zinc protein families evolved representatives that lack this metal, whereas selenocysteine in proteins is dynamically exchanged with cysteine. Several other elements, such as molybdenum and nickel, have a limited number of user protein families, but they are strictly dependent on these metals. Comparative genomics of trace elements provides a foundation for investigating the fundamental properties, functions, and evolutionary dynamics of trace element dependence in biology.


2021 ◽  
Vol 43 (4) ◽  
pp. 50-55
Author(s):  
L.V. SHUMLYANSKYY ◽  
V. KAMENETSKY ◽  
B.V. BORODYNYA

Results of a study of U-Pb and Hf isotope systematics and trace element concentrations in five zircon crystals separated from the Devonian Petrivske kimberlite are reported in the paper. Four zircons have yielded Paleoproterozoic and Archean ages, while one zircon grain gave a Devonian age of 383.6±4.4 Ma (weighted mean 206Pb/238U age). The Precambrian zircons have been derived from terrigenous rocks of the Mykolaivka Suite that is cut by kimberlite, or directly from the Precambrian rock complexes that constitute continental crust in the East Azov. The Devonian zircon crystal has the U-Pb age that corresponds to the age of kimberlite emplacement. It is 14 m.y. younger than zircon megacrysts found in the Novolaspa kimberlite pipe in the same area. In addition, Petrivske zircon is richer in trace elements than its counterparts from the Novolaspa pipe. Petrivske and Novolaspa zircons crystallized from two different proto-kimberlite melts, whereas the process of kimberlite formation was very complex and possibly included several episodes of formation of proto-kimberlite melts, separated by extended (over 10 M.y.) periods of time.


Author(s):  
P.A. Popov ◽  
◽  
V.S. Babunova ◽  

Hormones are an integral part of milk and throughout lactation, the content of certain hormones is unstable. Hormones regulate the process of starting lactation of animals, the lactation process itself, and also the other functions of the body. Milk is of great importance for the growth of young animals and the formation of immunity. Milk is a special product in the diet and is an important food and raw material for the production of dairy products for people. It contains a large amount of protein, fat, carbohydrates, vitamins and trace elements in biologically available form. But at the same time, over the past few years, more and more evidence has emerged that hormones in dairy products can impact on human health. Thus, some estrogens and insulin-like growth factor IGF-1 are involved in the initiation and provocation of breast, prostate and endometrial tumors. That’s why, it is necessary to normalize and control the content of certain hormones in milk with highly sensitive methods.


2007 ◽  
Vol 87 (Special Issue) ◽  
pp. 189-201 ◽  
Author(s):  
M I Sheppard ◽  
S C Sheppard ◽  
C A Grant

Canadian consumers are demanding a sustainable agricultural industry as well as products delivered under Best Management Practices (BMPs). Trace element accumulation in soils may influence crop productivity, food quality and ecosystem and human health. Canada’s feed and foodstuff export industry has already faced cases of penalties for high trace element content [cadmium (Cd) in durum wheat]. Thus, it is imperative to be able to estimate the accumulation and potential short- and long-term impacts of trace elements in soil. A national-level Trace Element Indicator (TEI) based on present loadings of trace elements to agricultural land is in progress. An Expert Panel including Canadian, American and Australian experts guided the assembly of a proposed methodology for this TEI. The proposed TEI, described briefly here, is a critical load approach with a single expression of the risk of impact from single or multiple trace elements from multiple sources (manures, biosolids, effluents and fertilizers and natural processes), invoked in a stochastic manner. Two key data requirements are the current background levels of trace elements in soil, and the leachability of these trace elements. A survey of total and soluble concentrations of 54 elements in up to 112 soils was completed. Although preliminary in scope, these represent key soil series in Canada. From this, a database of the solid/liquid partition coefficient, Kd, was computed. These Kd values will be used to characterize the leachability of the trace elements. Key words: Cadmium, copper, zinc, lead, nickel, uranium, metals, Kd, distribution coefficient


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