scholarly journals Assessment of Potentially Toxic Elements in Egbetua Stream Sediments, South-Western Nigeria

2021 ◽  
Vol 2 (6) ◽  
pp. 49-52
Author(s):  
S. O. Obaje
Keyword(s):  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Southwestern Nigeria ◽  
Low Concentrations ◽  
Edo State ◽  
Baseline Values ◽  
High Concentrations ◽  
Fluorescence Spectrometer ◽  
Very High ◽  
Urgent Action

The study area is located in Egbetua area in Akoko Edo Local Government Area of Edo State, southwestern Nigeria. the aim of the study is to assess the concentrations of potentially toxic elements in sediments from the study area. Ten samples collected from various locations in Egbetua stream were subjected to standard geochemical analysis using energy dispersive x-ray fluorescence spectrometer model “Minipal 4”. The average concentrations of six elements are V (26.89 ppm), Cr (32.33 ppm), Co (6.13 ppm), Ni (16.10 ppm), Au (21.13 ppm), and Zr (1,285.20 ppm) and they were compared to those of upper continental crust baseline values. V, Cr, Co, and Ni have extremely low concentrations, while Au and Zr have very high concentrations. Moreover, V, Cr, Co, and Ni have average enrichment ratios of 0.28, 0.35, 0.35 and 0.34, respectively, which are < 1 implying their depletion in relation to their average crustal baseline concentrations. On the other hand, Au and Zr are highly enriched in the study area. Au has average geoaccumulation index (Igeo) values of 4.40 indicative of strongly to extremely polluted, while Cr, Co, Ni and Zr have average Igeo values of 10.95, 6.14, 9.98 and 17.34, respectively, indicative of sediments that are extremely polluted. The potentially toxic elements pose very serious environmental geochemical pollution threat in the study area. It is recommended that urgent action should be taken to mitigate and clean the study area of these potentially toxic elements.

scholarly journals Potentially Toxic Elements (PTEs) in Soils and Bulbs of Elephant Garlic (Allium ampeloprasum L.) Grown in Valdichiana, a Traditional Cultivation Area of Tuscany, Italy

2021 ◽  
Vol 11 (15) ◽  
pp. 7023
Author(s):  
Vannini Andrea ◽  
Martina Grattacaso ◽  
Giulia Canali ◽  
Francesco Nannoni ◽  
Luigi Antonello Di Lella ◽  
...  
Keyword(s):  
Health Risk ◽  
Inductively Coupled Plasma ◽  
Toxic Elements ◽  
Daily Intake ◽  
Potentially Toxic Elements ◽  
Time Data ◽  
Allium Ampeloprasum ◽  
Inductively Coupled ◽  
Risk Indices ◽  
High Concentrations

The aim of this study was to provide, for the first time, data on the concentration of potentially toxic elements (PTEs) in soils and bulbs of elephant garlic (Allium ampeloprasum L.) cultivated in Valdichiana, a traditional agricultural area of Tuscany, Italy. Bulbs of elephant garlic and soil samples were collected in four cultivation fields and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) to determine the concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, Sb, Tl, U, V, Zn. The concentrations of these PTEs in bulbs and cultivation soils were used to calculate geochemical, ecological and health risk indices. The results of this study suggest that, although bulbs of elephant garlic from the Valdichiana area may present slightly high concentrations of Cd, Ni and Pb, the associated health risk based on the daily intake is absolutely negligible. Cultivation soils had somewhat high Cu concentrations probably due to the diffuse use of Cu-based products in agriculture, but showed overall a very low ecological risk.

scholarly journals Environmental Threats of Ancient Pb Mining and Metallurgical Activities in the Linares Mining District (Southern Spain)

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1459
Author(s):  
Carlos Boente ◽  
Carlos Sierra ◽  
Julián Martínez ◽  
Eduardo Rodríguez-Valdés ◽  
Elías Afif ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Mining District ◽  
Land Uses ◽  
Environmental Threats ◽  
Industrial Sites ◽  
High Concentrations ◽  
Insight Into ◽  
Metallurgical Activities

Former industrial sites are now dedicated to other land uses in the Linares mining district. Here we selected five residential/farming areas (squares of 1 km2 each) and sought to evaluate the levels of contamination by Potentially Toxic Elements (PTEs) of the soils, and also to offer an insight into the threat these pollutants may pose to human health or the environment by means of risk assessment. High concentrations especially of Pb, and also of As, Cd, Cu and Zn were found in quantities that are considerably bioavailable. Moreover, risk assessment revealed unacceptable concentrations for Pb and As in all the areas as well as for Cd and Cu in some squares.

scholarly journals Detection of endotoxins with the Limulus test in burned and unburned mice infected with different species of gramnegative bacteria

1975 ◽  
Vol 75 (1) ◽  
pp. 99-112 ◽  
Author(s):  
R. J. Jones ◽  
E. A. Roe ◽  
R. E. Dyster
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Low Concentrations ◽  
High Concentrations ◽  
Very High ◽  
Limulus Test

SUMMARYThe Limulus test detected endotoxins in the plasma of burned and unburned mice infected with different species of gram-negative bacteria. Individual strains of different species of gram-negative bacteria produced different amounts of endotoxin in the plasma of infected mice. Plasma from mice given lethal infections showed very high concentrations of endotoxin. Low concentrations of endotoxin in the plasma were tolerated by mice but high concentrations were invariably fatal. A polyvalent pseudomonas vaccine reduced endotoxin in the plasma of mice given lethal infections of Pseudomonas aeruginosa.

scholarly journals Spatial Mobility of U and Th in a U-enriched Area (Central Portugal)

2020 ◽  
Vol 10 (21) ◽  
pp. 7866
Author(s):  
Margarida Antunes ◽  
António Santos ◽  
Teresa Valente ◽  
Teresa Albuquerque
Keyword(s):  
Toxic Elements ◽  
Mine Drainage ◽  
Stream Sediments ◽  
Potentially Toxic Elements ◽  
Uranium Mine ◽  
Spatial Mobility ◽  
Contamination Index ◽  
Mine Dumps ◽  
Central Portugal ◽  
High Concentrations

Uranium and thorium are toxic in different environments. The exploitation of uranium mines and associated mine drainage leaching towards streams, sediments, and soils cause relevant pollution. The U-mine areas present high concentrations of potentially toxic elements with several consequences to ecosystems and human health. Physicochemical and potentially toxic elements of mine dumps, stream sediments, and soils from the Canto Lagar uranium mine area (Central Portugal) were analyzed. Stream sediments, soils, and mine dumps show a large range in the concentration values of Fe, U, As, Cu, Zn, Pb, and Th, suggesting geological and mine contributions. Most of the selected potential toxic elements from sediments present a low to moderate contamination degree, except for As, W, and U, which vary between high and very high contamination index. The soils must not be used in agricultural or residential activities due to contamination in As and U. This abandoned mine represents an environmental risk due to the spatial mobility and dispersion of potentially toxic elements from the dumps to the sediments and soils, as well as by surface runoff and wind.

Copper, nickel, and thallium uptake by the lichen Cladina rangiferina

1981 ◽  
Vol 59 (1) ◽  
pp. 91-100 ◽  
Author(s):  
M. A. S. Burton ◽  
P. LeSueur ◽  
K. J. Puckett
Keyword(s):  
Metal Uptake ◽  
Deionized Water ◽  
Metabolic Inhibitors ◽  
Temperature Dependent ◽  
Low Concentrations ◽  
Nickel Uptake ◽  
High Concentrations ◽  
Uptake Studies ◽  
Cladina Rangiferina ◽  
Very High

Metal uptake studies with Cladina rangiferina showed that the affinity for nickel was much lower than for copper or thallium. Nickel uptake was not decreased by the absence of light or oxygen or by pretreatment with metabolic inhibitors. Nickel uptake was not temperature dependent but was very dependent upon pH.Cation-exchange studies demonstrated that there was a stoichiometric exchange of Ni2+ for Sr2+, and Cu2+ for Sr2+. The exchange of Tl+ for Sr2+ was not stoichiometric, excess Tl+ was accumulated in relation to the Sr2+ released. The ratio of Sr2+:Tl+ exchange increased with increasing Tl+ availability from 1:9 (12.5 μmol Tl+ available/g of lichen) to 1:2 (500 μmol Tl+ available). Acid-treated lichen gave the expected exchange ratio of 1:2. Washing of the thalli with deionized water resulted in the continued loss of Tl+ from acid-treated and live C. rangiferina. Copper and nickel were not released in this manner.Increasing concentrations of copper and thallium produced a corresponding loss of potassium from the thallus. The potassium loss was initiated at low concentrations of copper and thallium whereas very high concentrations of manganese and nickel were required to bring about the same response.

scholarly journals Etude, dans le raisin, de l'activité β-glucosidase

OENO One ◽  
1988 ◽  
Vol 22 (2) ◽  
pp. 125
Author(s):  
C. Biron ◽  
Robert Cordonnier ◽  
Ollivier Glory ◽  
Ziya Günata ◽  
Jean-Claude Sapis
Keyword(s):  
Plant Material ◽  
Grape Berry ◽  
Cabernet Sauvignon ◽  
Mature Fruit ◽  
Glucosidase Activity ◽  
Low Concentrations ◽  
High Concentrations ◽  
Grape Leaf ◽  
Method Of Extraction ◽  
Very High

<p style="text-align: justify;">Dans ce travail, on étudie l'activité β-glucosidase du raisin. Une méthode d'extraction de l'enzyme à partir du matériel végétal a été mise au point et optimisée. L'activité enzymatique est mesurée spectrophotométriquement avec le paranitrophénylglucopyranoside comme substrat. Dans la baie de raisin, la β-glucosidase est concentrée dans les parties solides, pellicule et pulpe. Dans le jus, elle est en faible quantité. Dans la feuille de vigne, l'activité est élevée dans le limbe, faible dans le pétiole. Au cours de la maturation du raisin l'activité β-glucosidase augmente jusqu'à la maturité. Au-delà, jusqu'au stade de surmaturation, elle reste constante. Dans les raisins mars, la β-glucosidase est présente dans toutes les variétés étudiées, aussi bien dans les variétés aromatiques (Muscat d'Alexandrie, Muscat de Frontignan, Muscat de Hambourg) que dans celles non aromatiques (Carignan, Grenache, Cinsaut, Baroque, Cabernet-Sauvignon, Syrah, Merlot). Pour un millésime donné, l'activité β-glucosidase varie selon la variété. Les activités les plus élevées ont été rencontrées dans les Muscats, le Carignan, la Syrah et le Merlot. Elles sont environ 2,8 fois plus élevées que les activités les plus faibles. Pour une variété donnée, les niveaux d'activité varient fréquemment selon le millésime.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">β-glucosidase activity in grape was studied. A method of extraction of the enzyme from plant material was optimized and glucosidase activity measured spectrophotometrically using paranitrophenylglucopyranoside as substrate. High concentrations of β-glucosidase were found in grape berry solids (skin and pulp) and low concentrations in the juice. This distribution is similar to that of free terpenols in the same parts of the berry. The β-glucosidase content were very high in grape leaf blades and low in stems. Activity of the enzyme increased during maturation of the fruit. It was found in mature fruit of both aromatic (Muscat of Alexandria, Muscat of Frontignan, Muscat of Hamburg) and non-aromatic (Carignane, Grenache, Cinsaut, Baroque, Cabernet-Sauvignon, Sirah, Merlot) varieties. β-glucosidase activity varied according to variety for a given vintage. The highest activities (approximately 2.8 times higher than the lowest observed) were found in the differents Muscats and also in non-aromatic varieties such as Sirah, Merlot and Carignane. β-glucosidase activity in a given variety was frequently found to vary considerably from one vintage to another.</p>

Mitotic blocking agents for suspension cultures of maize 'Black Mexican Sweet' cell lines

Genome ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 475-478 ◽  
Author(s):  
J. Stadler ◽  
R. Phillips ◽  
M. Leonard
Keyword(s):  
Mitotic Index ◽  
Culture Medium ◽  
Colchicine Treatment ◽  
Mitotic Arrest ◽  
Suspension Cultures ◽  
Metaphase Arrest ◽  
Low Concentrations ◽  
High Concentrations ◽  
Very High ◽  
Black Mexican Sweet

Good metaphase arrest (25% mitotic index) in maize (Zea mays L.) 'Black Mexican Sweet' suspension cultures can be obtained with colchicine treatment alone, but only if very high concentrations (0.5%; 12.5 mM) are used. This colchicine concentration is 5- to 10-fold greater than that required for optimum mitotic arrest in cell cultures of other plant species. In contrast, we report that the herbicide amiprophos methyl (APM) is a much more efficient metaphase inhibitor for 'Black Mexican Sweet' suspension cultures than colchicine. Low concentrations (50 μm) of APM applied for 21–28 h produce a similar 25% mitotic index, and the growth-inhibiting effects of this treatment are undetectable 24 h after the removal of APM from the culture medium, APM, therefore, may be a useful agent for mitotic arrest in experiments which require survival of the treated cells. Another antitubulin herbicide, trifuralin, also was tested for ability to promote metaphase arrest in 'Black Mexican Sweet' cultures, but it proved to be ineffective.Key words: mitotic arrest, colchicine, phosphoric amide herbicide.

Yeast actin with a subdomain 4 mutation (A204C) exhibits increased pointed-end critical concentration

2007 ◽  
Vol 85 (3) ◽  
pp. 319-325 ◽  
Author(s):  
David J. Teal ◽  
John F. Dawson
Keyword(s):  
Actin Polymerization ◽  
Critical Concentration ◽  
Structural Studies ◽  
Wild Type ◽  
Low Concentrations ◽  
Engineering Strategy ◽  
High Concentrations ◽  
Pointed End ◽  
Very High

Characterizing mutants of actin that do not polymerize will advance our understanding of the mechanism of actin polymerization and will be invaluable for the production of short F-actin structures for structural studies. To circumvent the problem of expressing dominant lethal nonpolymerizing actin in yeast, we adopted a cysteine engineering strategy. Here we report the characterization of a mutant of yeast actin, AC-actin, possessing a single pointed-end mutation, A204C. Expression of this mutant in yeast results in actin-polymerization-deficient phenotypes. When copolymerized with wild-type actin, ATP–AC-actin is incorporated into filaments. ADP–AC-actin participates in the nucleation and elongation of wild-type filaments only at very high concentrations. At low concentrations, ADP–AC-actin appears to participate only in the nucleation of wild-type filaments, suggesting that Ala-204 is involved in modulating the critical concentration of the pointed end of actin.

Hormone-stimulated glycogenolysis in isolated goldfish hepatocytes

1976 ◽  
Vol 231 (1) ◽  
pp. 191-197 ◽  
Author(s):  
MJ Birnbaum ◽  
J Schultz ◽  
JN Fain
Keyword(s):  
Cyclic Amp ◽  
Blocking Agent ◽  
Ionophore A23187 ◽  
Bacterial Collagenase ◽  
Goldfish Carassius Auratus ◽  
Low Concentrations ◽  
Cyclic Amp Accumulation ◽  
The Common ◽  
High Concentrations ◽  
Very High

Hepatocytes isolated from the liver of the common goldfish Carassius auratus L. with crude bacterial collagenase maintained ATP levels for at least 2 h. Glycogenolysis was maximally activated by 1 X 10(-6) M epinephrine and 5.8 X 10(-9) M glucagon. In liver cells incubated in calcium-free buffer containing 1 mM ethylene glycol-bis-(beta-aminoethylether)-N,N'-tetraacetic acid, basal glycogenolysis was enhanced by the addition of 1-4 mM calcium but the elevation of cyclic AMP and glycogenolysis due to epinephrine was unaffected by calcium. The divalent cation ionophore A23187 did not alter basal or hormone-stimulated glycogenolysis. Isoproterenol was approximately as potent as epinephrine but phenylephrine was glycogenolytic only at very high concentrations. l-Propranolol competitively inhibited the increased glycogenolysis due to catecholamines but phentolamine was ineffective as a blocking agent. Isoproterenol and epinephrine stimulated glycogenolysis at lower concentrations than those required to elevate cyclic AMP accumulation. Phenylephrine was without effect on cyclic AMP. Propranolol competitively inhibited both epinephrine- and isoproterenol-stimulated cyclic AMP accumulation, but phentolamine did not block either response. Catecholamine-stimulated glycogenolysis in goldfish liver is apparently a beta-adrenergic effect. However, low concentrations of epinephrine enhance glycogenolysis without affecting total cyclic AMP.

scholarly journals Some properties of pyruvate and 2-oxoglutarate oxidation by blowfly flight-muscle mitochondria

1972 ◽  
Vol 127 (1) ◽  
pp. 271-283 ◽  
Author(s):  
R. G. Hansford
Keyword(s):  
Oxygen Uptake ◽  
Isocitrate Dehydrogenase ◽  
Adenine Nucleotides ◽  
Slight Reduction ◽  
Glycerol Phosphate ◽  
Pyruvate Oxidation ◽  
Low Concentrations ◽  
High Concentrations ◽  
Kinetics Of ◽  
Very High

1. High rates of state 3 pyruvate oxidation are dependent on high concentrations of inorganic phosphate and a predominance of ADP in the intramitochondrial pool of adenine nucleotides. The latter requirement is most marked at alkaline pH values, where ATP is profoundly inhibitory. 2. Addition of CaCl2 during state 4, state 3 (Chance & Williams, 1955) or uncoupled pyruvate oxidation causes a marked inhibition in the rate of oxygen uptake when low concentrations of mitochondria are employed, but may lead to an enhancement of state 4 oxygen uptake when very high concentrations of mitochondria are used. 3. These properties are consistent with the kinetics of the NAD-linked isocitrate dehydrogenase (EC 1.1.1.41) from this tissue, which is activated by isocitrate, citrate, ADP, phosphate and H+ ions, and inhibited by ATP, NADH and Ca2+. 4. Studies of the redox state of NAD and cytochrome c show that addition of ADP during pyruvate oxidation causes a slight reduction, whereas addition during glycerol phosphate oxidation causes a `classical' oxidation. Nevertheless, it is concluded that pyruvate oxidation is probably limited by the respiratory chain in state 4 and by the NAD-linked isocitrate dehydrogenase in state 3. 5. The oxidation of 2-oxoglutarate by swollen mitochondria is also stimulated by high concentrations of ADP and phosphate, and is not uncoupled by arsenate.

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