Soil-to-plant transfer of 137Cs related to its geochemical partitioning in Oxisols of tropical areas

2005 ◽  
pp. 17-28
Author(s):  
Maria Angélica M. Wasserman
Keyword(s):  
Geochemical Partitioning ◽  
Plant Transfer ◽  
Tropical Areas

ANTICANCER EFFECT OF UVARIA GENUS

2014 ◽  
pp. 98-101
Author(s):  
Thi Bich Hien Le ◽  
Viet Duc Ho ◽  
Thi Hoai Nguyen
Keyword(s):  
Biological Activities ◽  
Current Trend ◽  
Healthcare Systems ◽  
Chemical Compositions ◽  
Cancer Therapies ◽  
Pharmacological Effects ◽  
Anticancer Effect ◽  
Anti Cancer ◽  
Tropical Areas ◽  
Cancer Activity

Nowadays, cancer treatment has been a big challenge to healthcare systems. Most of clinical anti-cancer therapies are toxic and cause adverse effects to human body. Therefore, current trend in science is seeking and screening of natural compounds which possess antineoplastic activities to utilize in treatment. Uvaria L. - Annonaceae includes approximately 175 species spreading over tropical areas of Asia, Australia, Africa and America. Studies on chemical compositions and pharmacological effects of Uvaria showed that several compound classes in this genus such as alkaloid, flavonoid, cyclohexen derivaties, acetogenin, steroid, terpenoid, etc. indicate considerable biological activities, for example anti-tumor, anti-cancer, antibacterial, antifungal, antioxidant, etc. Specifically, anti-cancer activity of fractions of extract and pure isolated compounds stands out for cytotoxicity against many cancer cell lines. This study provides an overview of anti-cancer activity of Uvaria and suggests a potential for further studies on seeking and developing novel anti-cancer compounds. Key words: Anti-cancer, Uvaria.

High variability in geochemical partitioning of iron, manganese and harmful trace metals in sediments of the mining port of Santa Rosalia, Baja California Sur, Mexico

2014 ◽  
Vol 145 ◽  
pp. 51-63 ◽  
Author(s):  
Miguel Angel Huerta-Diaz ◽  
Albino Muñoz-Barbosa ◽  
Xose Luis Otero ◽  
Jacob Valdivieso-Ojeda ◽  
Enrique Crisanto Amaro-Franco
Keyword(s):  
Trace Metals ◽  
Baja California ◽  
High Variability ◽  
Baja California Sur ◽  
Geochemical Partitioning ◽  
Santa Rosalia ◽  
Iron Manganese

scholarly journals Evaluating Carbon Monoxide and Aerosol Optical Depth Simulations from CAM-Chem Using Satellite Observations

2021 ◽  
Vol 13 (11) ◽  
pp. 2231
Author(s):  
Débora Souza Alvim ◽  
Júlio Barboza Chiquetto ◽  
Monica Tais Siqueira D’Amelio ◽  
Bushra Khalid ◽  
Dirceu Luis Herdies ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
South America ◽  
Aerosol Optical Depth ◽  
Tropical Forests ◽  
Optical Depth ◽  
Eastern China ◽  
Central Africa ◽  
Central China ◽  
Stratospheric Chemistry ◽  
Tropical Areas

The scope of this work was to evaluate simulated carbon monoxide (CO) and aerosol optical depth (AOD) from the CAM-chem model against observed satellite data and additionally explore the empirical relationship of CO, AOD and fire radiative power (FRP). The simulated seasonal global concentrations of CO and AOD were compared, respectively, with the Measurements of Pollution in the Troposphere (MOPITT) and the Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite products for the period 2010–2014. The CAM-chem simulations were performed with two configurations: (A) tropospheric-only; and (B) tropospheric with stratospheric chemistry. Our results show that the spatial and seasonal distributions of CO and AOD were reasonably reproduced in both model configurations, except over central China, central Africa and equatorial regions of the Atlantic and Western Pacific, where CO was overestimated by 10–50 ppb. In configuration B, the positive CO bias was significantly reduced due to the inclusion of dry deposition, which was not present in the model configuration A. There was greater CO loss due to the chemical reactions, and shorter lifetime of the species with stratospheric chemistry. In summary, the model has difficulty in capturing the exact location of the maxima of the seasonal AOD distributions in both configurations. The AOD was overestimated by 0.1 to 0.25 over desert regions of Africa, the Middle East and Asia in both configurations, but the positive bias was even higher in the version with added stratospheric chemistry. By contrast, the AOD was underestimated over regions associated with anthropogenic activity, such as eastern China and northern India. Concerning the correlations between CO, AOD and FRP, high CO is found during March–April–May (MAM) in the Northern Hemisphere, mainly in China. In the Southern Hemisphere, high CO, AOD, and FRP values were found during August–September–October (ASO) due to fires, mostly in South America and South Africa. In South America, high AOD levels were observed over subtropical Brazil, Paraguay and Bolivia. Sparsely urbanized regions showed higher correlations between CO and FRP (0.7–0.9), particularly in tropical areas, such as the western Amazon region. There was a high correlation between CO and aerosols from biomass burning at the transition between the forest and savanna environments over eastern and central Africa. It was also possible to observe the transport of these pollutants from the African continent to the Brazilian coast. High correlations between CO and AOD were found over southeastern Asian countries, and correlations between FRP and AOD (0.5–0.8) were found over higher latitude regions such as Canada and Siberia as well as in tropical areas. Higher correlations between CO and FRP are observed in Savanna and Tropical forests (South America, Central America, Africa, Australia, and Southeast Asia) than FRP x AOD. In contrast, boreal forests in Russia, particularly in Siberia, show a higher FRP x AOD correlation than FRP x CO. In tropical forests, CO production is likely favored over aerosol, while in temperate forests, aerosol production is more than CO compared to tropical forests. On the east coast of the United States, the eastern border of the USA with Canada, eastern China, on the border between China, Russia, and Mongolia, and the border between North India and China, there is a high correlation of CO x AOD and a low correlation between FRP with both CO and AOD. Therefore, such emissions in these regions are not generated by forest fires but by industries and vehicular emissions since these are densely populated regions.

Differential diagnoses of severe COVID‐19 in tropical areas: The experience of Reunion Island

2020 ◽  
Author(s):  
Pauline Krol ◽  
Nathalie Coolen‐Allou ◽  
Laura Teysseyre ◽  
Nicolas Traversier ◽  
Floryan Beasley ◽  
...  
Keyword(s):  
Differential Diagnoses ◽  
Reunion Island ◽  
Réunion Island ◽  
Tropical Areas

scholarly journals Traditional uses, phytochemistry, pharmacology and toxicity of Arisaema (Areaceae): a review

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Heena Ali ◽  
Ubaid Yaqoob
Keyword(s):  
Skin Irritation ◽  
Clinical Applications ◽  
Human Populations ◽  
Main Body ◽  
Anticancer Activities ◽  
Medicinal Uses ◽  
The World ◽  
Different Types ◽  
Tropical Areas ◽  
Medicinal Properties

Abstract Background The genus Arisaema (Areaceae), popularly known as cobra lilies and jack in pulpit is mainly found in temperate to tropical areas of all continents except South America, Europe and Australia and contain about more than 250 species. Arisaema genus is being used by the different folks of human populations for medicinal as well as food purposes. Arisaema plants are used for the treatment of different types of diseases. There have been several attempts to highlight different aspects of genus Arisaema by describing it in terms of phytochemistry and medicinal uses. The present study is, however, an attempt to put together all the former data available related to the phytochemistry and medicinal uses of genus Arisaema. Main body The phytochemicals of the plant include alkaloids, phenols, terpenes, flavonoids, lectins, saponins, glycosides, triterpenoids, stigmasterols, n-alkanes, n-alkanols sitosterols, campesterol, oxalates, coumarins, tannins etc. Moreover, the properties such as antioxidant, antifungal, antibacterial, insecticidal, antimicrobial, cytotoxic, nematocidal, antiallergic antitumour and anticancer activities are also shown by the plants belonging to genus Arisaema. Arisaema plants have been traditionally used to treat various ailments such as resolving phlegm, dampness, and to treat asthma, bronchitis, cold, cough, and laryngitis etc. It has been found that there are several species which are toxic by nature. The development of clinical applications of arisaematis rhizomes had been seriously constrained due to its toxic properties like, mouth and lingua pain, even respiration slowing and suffocation, mucous membrane and skin irritation etc. and this toxicity of arisaematis rhizomes is due to raphide components. Conclusions The collection of data available on the phytochemistry of genus Arisaema is not sufficient as further work is required to do on phytochemical and medicinal basis. The data available on phytochemistry and medicinal properties of the plants belonging to genus Arisaema throws light on various species of Arisaema which are medicinally important and have been exploited to treat different types of diseases in the world.

Environmental Availability of Potentially Toxic Elements in an Agricultural Mediterranean Site

2019 ◽  
Vol 25 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Dimitrios Alexakis ◽  
Dimitra Gamvroula ◽  
Eleni Theofili
Keyword(s):  
Sequential Extraction ◽  
Toxic Elements ◽  
Soil Depth ◽  
Extraction Procedure ◽  
Potential Ecological Risk ◽  
Potentially Toxic Elements ◽  
Geochemical Partitioning ◽  
Exchangeable Fraction ◽  
High Bioavailability

ABSTRACT Total contents of 36 potentially toxic elements are summarized for agricultural topsoil (n = 12; soil depth = 0–20 cm), subsoil (n = 12; soil depth = 20–40 cm), and representative rock samples collected from a Mediterranean site (Megara Plain, Greece). The five-stage sequential extraction procedure for the geochemical partitioning of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), and nickel (Ni), proposed by Tessier, was applied to topsoil and subsoil collected from the study area. Soil Cd was highly associated with exchangeable fraction, illustrating high bioavailability of this element. The order of mobility of the elements was as follows: Cd > Cu > Co > Zn > Ni > Cr > Mn. Results from sequential extraction experiments illustrated that the bioavailability of Cu, Co, and Zn is moderate, while Ni, Cr, and Mn presented low bioavailability, indicating that these elements could pose a limited threat to the quality of crops. Cadmium is the chief contamination controlling factor posing moderate potential ecological risk. The contamination sources of the examined elements are discussed.

Complementary Sensitivity Design of PID Controllers for Arbitrary-Order Transfer Functions With Time Delay

2008 ◽  
Author(s):  
Tooran Emami ◽  
John M. Watkins
Keyword(s):  
Time Delay ◽  
Transfer Functions ◽  
Linear Time ◽  
Order System ◽  
Pid Controllers ◽  
Single Input Single Output ◽  
Linear Time Invariant ◽  
Single Output ◽  
Plant Transfer ◽  
Time Invariant

A graphical technique for finding all proportional integral derivative (PID) controllers that stabilize a given single-input-single-output (SISO) linear time-invariant (LTI) system of any order system with time delay has been solved. In this paper a method is introduced that finds all PID controllers that also satisfy an H∞ complementary sensitivity constraint. This problem can be solved by finding all PID controllers that simultaneously stabilize the closed-loop characteristic polynomial and satisfy constraints defined by a set of related complex polynomials. A key advantage of this procedure is the fact that it does not require the plant transfer function, only its frequency response.

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