Influence of a Hexachlorobiphenyl in Great Lakes Phytoplankton in Continuous Culture

1982 ◽  
Vol 39 (3) ◽  
pp. 388-394 ◽  
Author(s):  
Timoth C. Lederman ◽  
G-Yull Rhee
Keyword(s):  
Great Lakes ◽  
Continuous Culture ◽  
Dry Weight ◽  
Initial Response ◽  
Inhibitory Effect ◽  
Dose Response Relationship ◽  
Chl A ◽  
Ankistrodesmus Falcatus ◽  
Fragilaria Crotonensis ◽  
C Assimilation

The influence of 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCB) on the growth of Great Lakes phytoplankters Fragilaria crotonensis, Ankistrodesmus falcatus, and Microcystis sp. was investigated in continuous culture under nutrient-sufficient and phosphate (P) limited conditions. Growth rate (μ) was inhibited only in F. crotonensis at cellular HCB concentrations as low as 4 × 10−8 ng/cell (0.8 μg/g dry weight) in nutrient-sufficient cultures; there appeared to be a dose–response relationship between cellular HCB and μ. Microcystis sp. and A. falcatus showed no inhibitory effect at cellular HCB levels up to 5 × 10−8 ng/cell (3.6 μg/g dry weight) and 30 × 10−8 ng/cell (11.5 μg/g dry weight), respectively. Under P-limited conditions HCB also affected F. crotonensis but not A. falcatus. The initial response of F. crotonensis to HCB addition was a significant increase in μ, followed by a sharp decline. In both nutrient-rich and P-limited F. crotonensis the cellular chlorophyll a (chl a) concentration decreased with the accumulation of HCB, yet the 14C assimilation rate per unit chl a increased. Cellular P concentration in the P-limited cells also decreased with the accumulation of HCB. Such responses were not observed in the other species.Key words: polychlorinated biphenyls, hexachlorobiphenyl, bioconcentration. Great Lakes, algae, continuous culture

Bioconcentration of a Hexachlorobiphenyl in Great Lakes Planktonic Algae

1982 ◽  
Vol 39 (3) ◽  
pp. 380-387 ◽  
Author(s):  
Timoth C. Lederman ◽  
G-Yull Rhee
Keyword(s):  
Great Lakes ◽  
Bioconcentration Factor ◽  
Dry Weight ◽  
Cell Number ◽  
Cellular Lipid ◽  
Bioconcentration Factors ◽  
Planktonic Algae ◽  
Ankistrodesmus Falcatus ◽  
Fragilaria Crotonensis ◽  
Adsorption Desorption

The bioconcentration of 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCB) was examined in the Great Lakes algae Fragilaria crotonensis, Ankistrodesmus falcatus, and Microcystis sp. The bioconcentration factors varied from species to species, whether they were expressed in terms of cell number, dry weight, cellular carbon, or cellular lipid. The factors were in the range of 105–106 and increased with decreasing biomass. The existence of a mucilage layer in F. crotonensis was associated with a twofold increase in the bioconcentration factor. Surface adsorption appeared to contribute only slightly to the bioaccumulation of HCB. HCB desorbed from all species but at a much slower rate than its adsorption.Key words: bioconcentration, bioaccumulation, polychlorinated biphenyls, hexachlorobiphenyl, adsorption, desorption, algae

Zebra Mussels as Biomonitors for Organic Contaminants in the Lower Great Lakes

1996 ◽  
Vol 31 (2) ◽  
pp. 411-432 ◽  
Author(s):  
Michael E. Comba ◽  
Janice L. Metcalfe-Smith ◽  
Klaus L.E. Kaiser
Keyword(s):  
Great Lakes ◽  
Organic Contaminants ◽  
Lake Erie ◽  
Soft Tissues ◽  
Lake Ontario ◽  
Dry Weight ◽  
Zebra Mussels ◽  
Organic Contamination ◽  
Contamination Levels ◽  
St Lawrence River

Abstract Zebra mussels were collected from 24 sites in Lake Erie, Lake Ontario and the St. Lawrence River between 1990 and 1992. Composite samples of whole mussels (15 sites) or soft tissues (9 sites) were analyzed for residues of organochlo-rine pesticides and PCBs to evaluate zebra mussels as biomonitors for organic contaminants. Mussels from most sites contained measurable quantities of most of the analytes. Mean concentrations were (in ng/g, whole mussel dry weight basis) 154 ΣPCB, 8.4 ΣDDT, 3.5 Σchlordane, 3.4 Σaldrin, 1.4 ΣBHC, 1.0 Σendosulfan, 0.80 mirex and 0.40 Σchlorobenzene. Concentrations varied greatly between sites, i.e., from 22 to 497 ng/g for ΣPCB and from 0.08 to 11.6 ng/g for ΣBHC, an indication that mussels are sensitive to different levels of contamination. Levels of ΣPCB and Σendosulfan were highest in mussels from the St. Lawrence River, whereas mirex was highest in those from Lake Ontario. Overall, mussels from Lake Erie were the least contaminated. These observations agree well with the spatial contaminant trends shown by other biomoni-toring programs. PCB congener class profiles in zebra mussels are also typical for nearby industrial sources, e.g., mussels below an aluminum casting plant contained 55% di-, tri- and tetrachlorobiphenyls versus 31% in those upstream. We propose the use of zebra mussels as biomonitors of organic contamination in the Great Lakes.

Increased fecundity of the cladoceran Moinodaphnia macleayi on a diet supplemented with a green alga, and its use in uranium toxicity tests

1993 ◽  
Vol 44 (3) ◽  
pp. 389 ◽  
Author(s):  
RV Hyne ◽  
A Padovan ◽  
DL Parry ◽  
SM Renaud
Keyword(s):  
Unsaturated Fatty Acids ◽  
Lipid Fraction ◽  
Algal Species ◽  
Cichlid Fish ◽  
Dry Weight ◽  
Scenedesmus Quadricauda ◽  
Toxicity Tests ◽  
Ankistrodesmus Falcatus ◽  
Algal Diets ◽  
Chlamydomonas Sp

The effects of two synthetic diets and four algal diets on the survival and fecundity of Moinodaphnia macleayi for use in life-cycle toxicity tests were determined. The synthetic foods were a suspension of blended cichlid fish pellets with powdered alfalfa, either prepared fresh or fermented in natural water for 3 days. The algae, isolated from the habitat of M. rnacleayi in the Alligator Rivers Region, were Selenastrum sp., Ankistrodesmus (falcatus?), Scenedesmus quadricauda and a Chlamydomonas sp. Each alga was tested alone or as a supplement to the fermented synthetic food. The diet that supported the greatest number of young and the highest survival rate over a 5-day period was a combination of the fermented synthetic food and Chlamydomonas sp. Analysis of the fatty acid composition of the lipid fraction of the four algal species showed that Chlamydomonas sp., Selenastrum sp. and Scenedesmus quadricauda had significant concentrations of the highly unsaturated fatty acids 18 : 2(n-6), 18 : 3(n-6) and 18: 3(n-3). In terms of size and dry weight, Chlamydomonas sp. was the smallest of the algal cells studied. The toxicity of uranium to M. macleayi survival, determined under standard conditions, was a lowest-observed-effect concentration (LOEC) of 200 �g L-1 after 48 h and 25 �g L-1 after 5 days.

Inhibitory Effects of Indomethacin on Implantation and its Related Phenomena

1996 ◽  
Vol 24 (4) ◽  
pp. 358-362 ◽  
Author(s):  
K Kanayama ◽  
H Osada ◽  
K Nariai ◽  
T Endo
Keyword(s):  
Birth Rate ◽  
Inhibitory Effect ◽  
High Rate ◽  
Control Group ◽  
Corpora Lutea ◽  
Response Relationship ◽  
Inhibitory Effects ◽  
Dose Response Relationship ◽  
Dose Dependent ◽  
Implantation Period

The dose-response relationship for the inhibitory effect of indomethacin on implantation and continuance of pregnancy was examined in four groups of rabbits administered with indomethacin (2.5, 5.0, 7.5 and 10.0 mg/kg) during the implantation period and compared with a control group. Implanted fetuses and corpora lutea were counted by laparotomy, and the number of offspring born was noted. The inhibitory effect of indomethacin on implantation was found to be dose–dependent, and the birth rate decreased in the indomethacin groups compared with the control group. As a result, even where implantation had been achieved, death of the implanted fetuses occurred at a high rate in rabbits administered with indomethacin during the implantation period.

scholarly journals Effect of mint (Mentha piperita L.) and caraway (Carum carvi L.) on the growth of some toxigenic aspergillus species and aflatoxin B1 production

2009 ◽  
pp. 131-139 ◽  
Author(s):  
Marija Skrinjar ◽  
Anamarija Mandic ◽  
Aleksandra Misan ◽  
Marijana Sakac ◽  
Ljubisa Saric ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Aspergillus Species ◽  
Mentha Piperita ◽  
Ph Values ◽  
Carum Carvi ◽  
The Media ◽  
Total Dry Weight ◽  
Poor Concentration

An inhibitory effect of various concentrations (0.0, 0.5, 1.0, 1.5 and 2,0%) of mint (Mentha piperita L.) and caraway (Carvum carvi L.) on the growth of A. fumigatus, A. flavus and A. ochraceus was examined during 10 days of cultivation in YES medium at temperature of 25?C. Mint showed stronger inhibitory effect than caraway. Total dry weight (g/l) after 10 days of the growth of A. fumigatus in YES medium with 0.5% of mint decreased by about 95%, A. flavus by 97% and A. ochraceus by about 82%. Addition of higher concentrations of mint (1.0, 1.5 and 2.0%) reduced the growth of all tested species. It was poor and hardly visible. pH values of the media increased with the increase of mint concentrations. A. fumigatus showed the highest sensitivity towards caraway and A. flavus the lowest. Total dry weight (g/l) after 10 days of growth of A. fumigatus in medium with 0.5% of caraway decreased by about 72% in comparison to the control. In media with higher concentrations of caraway, its growth was found to be very poor. Concentration of 1.0% of caraway reduced A. flavus growth by 15% and of 1.5% by 92%, in regard to the control. In medium with 2.0% of caraway the growth of A. flavus was observed as poor and hardly visible. The growth of A. ochraceus in medium with 0.5% of caraway decreased by about 85% comparing with control and further decrease was noticed by the increase of concentrations. In medium with 1.5% of caraway a reduction of about 95% of growth was found and under 2.0% of caraway it was poor. pH of the media also increased with the increase of caraway concentrations. Applied concentrations of mint and caraway inhibited completely the production of AB1 by A. flavus.

scholarly journals ALLELOPATHIC POTENTIAL OF WEED SPEICES AGERATUM CONYZOIDES L. AND CLEOME VISCOSA L. ON GERMINATION AND GROWTH OF SESAMUM INDICUM L

2015 ◽  
Vol 2 (2) ◽  
pp. 114-117
Author(s):  
Anbarasan R ◽  
Prabhakaran J
Keyword(s):  
Growth Parameters ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Sesamum Indicum ◽  
Weed Species ◽  
Ageratum Conyzoides ◽  
Allelopathic Potential ◽  
Germination And Growth ◽  
Cleome Viscosa

Various concentrations (5%, 10%, 15% and 20%) of aqueous extracts prepared from two weed species namely Ageratum conyzoides L. and Cleome viscosa L. and used for the present experiments to determine their allelopathic potential on growth and developmental changes on sesame (Sesamum indicum L.). The weed extracts showed an inhibitory effect on germination percentage, root and shoot growth, and fresh and dry weight of sesame seedlings. The extracts of A.conyzoides had more inhibitory effect at 20%concentration,than that of C.viscosa on growth parameters of sesame.

scholarly journals Anti-fungal activities of constituents from Uvaria scheffleri and Artabotrys brachypetalus

2006 ◽  
Vol 51 (1) ◽  
pp. 79-86 ◽  
Author(s):  
A.C. Odebode ◽  
S.A. Jonker ◽  
C.C. Joseph ◽  
S.W. Wachira
Keyword(s):  
Fusarium Solani ◽  
Radial Growth ◽  
Fungal Pathogens ◽  
Dry Weight ◽  
Stem Bark ◽  
Inhibitory Effect ◽  
In Vitro Bioassay ◽  
Botryodiplodia Theobromae ◽  
Anti Fungal

The anti-fungal activity of schefflone, a mixture of dimmer, 3,5 dimethoxy carvacrol and annonaceous acetogenin, extracted from stem-bark and root of Uvaria scheffleri and Artabotrys bruchypetalus against Fusarium solani, Botryodiplodia theobromae, Asperillus niger and Aspergillus flavus was determined. An in-vitro bioassay showed that the minimum inhibitory effect of the compounds to the fungal pathogens occurred at 200 ppm in both radial growth and mycelia dry weight measurements. Acetogenin from A brachypetalus had a very strong anti-fungal effect on all the test fungi. The effects of the compounds were more pronounced on F solani than on the other. The bioassay methods also play a significant role in the sensitivity of the samples on the pathogens. .

scholarly journals Photosynthesis sensitivity to NH4+-N change with nitrogen fertilizer type

2014 ◽  
Vol 60 (No. 6) ◽  
pp. 274-279 ◽  
Author(s):  
A. Nasraoui-Hajaji ◽  
H. Gouia
Keyword(s):  
Net Photosynthesis ◽  
Dry Weight ◽  
N Fertilization ◽  
Photochemical Quenching ◽  
Negative Effects ◽  
Ps Ii ◽  
Chl A ◽  
Inhibitory Site ◽  
Tomato Growth ◽  
Non Photochemical Quenching

N-fertilization type affected differently tomato growth. In the field experiment, hydroponic cultures were conducted using NO<sub>3</sub>-N (5 mmol); mixture of KNO<sub>3</sub>-N (3 mmol) and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>-N (2 mmol); NH<sub>4</sub><sup>+</sup>-N (5 mmol) or urea&nbsp;(5 mmol) as nitrogen source. Compared to nitrate, ammonium and urea had negative effects on morphology and dry matter production. Effects of the different nitrogen forms were investigated by measuring several photosynthesis parameters and chl a fluorescence. Two different significant types of reaction were found. When nitrogen was added as ammonium or urea, dry weight, chlorophyll tenor, transpiration rate, stomatal conductance and photosynthetic activity were inhibited. Supply of ammonium or urea, reduced the ratio (F<sub>v</sub>/F<sub>m</sub>), photochemical quenching and enhanced the non photochemical quenching. These data suggest that the adverse decrease in tomato growth under ammonium or urea supply may be related principally to inhibition of net photosynthesis activity. The high non photochemical quenching shown in tomato fed with ammonium or urea indicated that PS II was the inhibitory site of NH<sub>4</sub><sup>+</sup>-N which was directly uptaken by roots, or librated via urea hydrolysis cycle.

scholarly journals Effect of photosensitisers on growth and morphology of Phytophthora citrophthora coupled with leaf bioassays in pear seedlings

2020 ◽  
Vol 56 (No. 2) ◽  
pp. 74-82 ◽  
Author(s):  
Antonios Zambounis ◽  
Oksana Sytar ◽  
Dimitris Valasiadis ◽  
Zoe Hilioti
Keyword(s):  
Mycelial Growth ◽  
Biological Effects ◽  
Dry Weight ◽  
Colony Growth ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Inhibitory Effects ◽  
Phytophthora Citrophthora ◽  
Irregular Shapes ◽  
Zoospore Production

The phytopathogenic oomycetes of the genus Phytophthora cause devastating economic losses worldwide.<br />Naphthodianthrone compounds, present in plant extracts of buckwheat and Saint John’s wort act as photosensitiser<br />agents and exhibit antimicrobial activity against a number of pathogens. In this study, we investigated the potential<br />inhibitory effects of fagopyrin and hypericin on Phytophthora citrophthora (R.E. Sm. &amp; E.H. Sm.) Leonian 1906, the<br />main causal agent of rot diseases in deciduous trees. Fagopyrin had the highest inhibitory effect in the colony growth<br />at a concentration of 2% of a stock solution (3 mg/mL), inducing clubbed hyphae with round tips. Notably, hypericin<br />also inhibited the radial colony growth and increased the hyphal branching at the subapical region, while also promoting<br />the formation of enlarged cells with irregular shapes growing collectively as biofilm-like structures. In terms of the<br />mycelial dry weight, although both photosensitisers had considerable inhibitory effects, the fagopyrin treatment was<br />most effective. Leaf bioassays showed that under dark conditions the photosensitiser pre-treated zoospores formed a<br />dense, but aberrant, mycelial growth with penetration defects. In contrast, when the zoospore production was performed<br />under light conditions, the zoospores failed to cause necrotic lesions and penetration events implying that their<br />virulence was impaired. These findings shed light on the biological effects of fagopyrin and hypericin in the regulation<br />of the mycelial growth, morphology and pathogenicity of P. citrophthora.

Dose-response study of alendronate sodium for the treatment of cancer-associated hypercalcemia.

1993 ◽  
Vol 11 (8) ◽  
pp. 1618-1623 ◽  
Author(s):  
S R Nussbaum ◽  
R P Warrell ◽  
R Rude ◽  
J Glusman ◽  
J P Bilezikian ◽  
...  
Keyword(s):  
Serum Calcium ◽  
Dose Response ◽  
Initial Response ◽  
Complete Response ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Alendronate Sodium ◽  
Double Blind ◽  
Days Of Therapy ◽  
Significant Difference

PURPOSE A randomized, double-blind, dose-ranging study of single-dose intravenous (IV) therapy with alendronate sodium (aminohydroxybutylidene bisphosphonate) was performed in patients with cancer-associated hypercalcemia. PATIENTS AND METHODS Patients with hypercalcemia who had not received antitumor therapy in the preceding 7 days were treated with 48 hours of IV hydration. Patients with persistent hypercalcemia (albumin-corrected serum calcium concentration [CSCC] > or = 11.5 mg/dL) were randomly assigned to receive 2.5, 5, 10, or 15 mg of alendronate infused over 2 hours, or 10 mg of alendronate infused over 24 hours. Fifty-nine patients were treated and 50 patients were assessable for the dose-response relationship. RESULTS Normalization of CSCC (< or = 10.5 mg/dL) was achieved in 22%, 82%, 75%, and 90% of assessable patients in the 2.5-, 5-, 10- (2- and 24-hour groups pooled), and 15-mg dose groups, respectively, within 8 days of therapy. Doses > or = 5 mg were significantly superior to the 2.5-mg dose level (P < .05). There was no significant difference in the minimum CSCC achieved between the 2- and 24-hour infusions of the 10-mg dose. Based on an intent-to-treat analysis of all randomized patients, the overall complete response rate was 74% for dose levels greater than 2.5 mg. For assessable patients who responded to > or = 5 mg of alendronate, the estimated median duration of normocalcemia was 10 days (range, 1 to 25). The estimated median time to relapse (CSCC > 11.5 mg/dL) was 15 days from initial treatment and 12 days from initial response, respectively. Adverse events included a transient febrile response in 34% of patients and eight episodes of reversible elevations in serum transaminase levels among treated patients. CONCLUSION While a statistically significant dose-response relationship was not clearly evident at doses greater than 5 mg, single doses of > or = 5 mg alendronate sodium effectively lowered serum calcium concentrations and were well tolerated in the treatment of cancer-associated hypercalcemia.

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