Factors Affecting Survival and Cation Concentration in the Blackflies Prosimulium fuscum/mixtum and the Mayfly Leptophlebia cupida during Spring Snowmelt

1988 ◽  
Vol 45 (12) ◽  
pp. 2123-2132 ◽  
Author(s):  
Ronald J. Hall ◽  
R. C. Bailey ◽  
Joseph Findeis
Keyword(s):  
Whole Body ◽  
Toxicity Tests ◽  
Transplant Experiment ◽  
Gut Content ◽  
Short Term ◽  
Factors Affecting ◽  
Ph Values ◽  
Zn Concentration ◽  
Spring Snowmelt

We used a transplant experiment to examine the effects of short-term pH depressions in spring on whole-body concentrations of nine metal cations (Ca, Mg, Na, Zn, Pb, Al, Mn, Cd, and Fe) and survival of two species of aquatic insects collected from two habitats with year-round differences in pH. Survival of Leptophlebia cupida and Prosimulium fuscum/mixtum was close to 100% in 4- and 10-d in situ toxicity tests prior to and during snowmelt at pH levels ranging from 6.5 to 4.2. Differences in metal concentrations (Zn, Cd, and Na) existed between mayflies collected from different streams with pH values of 6.2−5.6. Both species transplanted from pH 6.2 to 4.2 streamwater had significant decreases in whole-body concentrations of Ca, Al, and Mn. Additionally, mayflies had significant losses of Mg, Fe, and Pb, while blackflies decreased in whole-body Na and Zn concentration. Percentages of the whole-body Al concentration in the adsorbed, absorbed, and gut content fractions were 3.3, 31.7, and 65%, respectively, for L. cupida and 1.6, 56.4, and 42%, respectively, for P. fuscum/mixtum. The percent adsorbed doubled in transplanted (versus control) mayflies, but the overall whole-body Al concentration decreased.

scholarly journals Very short term dehydroepiandrosterone treatment in female adrenal failure: impact on carbohydrate, lipid and protein metabolism

2005 ◽  
Vol 152 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Jens Juel Christiansen ◽  
Claus Højbjerg Gravholt ◽  
Sanne Fisker ◽  
Niels Møller ◽  
Marianne Andersen ◽  
...  
Keyword(s):  
Adrenal Insufficiency ◽  
Whole Body ◽  
Acute Effects ◽  
Short Term ◽  
Double Blind ◽  
Substrate Metabolism ◽  
Dhea Treatment ◽  
Release Of Glycerol ◽  
Phenyl Alanine

Objective: In female adrenal insufficiency, dehydroepiandrosterone (DHEA) secretion is impaired and circulating androgen levels are severely reduced. We wanted to analyse the acute effects of physiological DHEA substitution on substrate metabolism. Design: We studied nine females with adrenal insufficiency after 9 days of oral DHEA replacement (50 mg/day) in a double-blind, placebo-controlled crossover study. Methods: Whole body and regional substrate metabolism was assayed in the basal state and during a euglycemic hyperinsulinemic glucose clamp by means of isotope dilution techniques (glucose, phenyl-alanine, tyrosine), indirect calorimetry and in situ lipolysis (microdialysis technique). Results: DHEA treatment normalized the levels of all androgens. Basal and insulin-stimulated total energy expenditure and rates of protein, lipid and glucose oxidation were unaffected by DHEA. Whole body turnover of glucose and protein were also unaffected by DHEA. Forearm breakdown of protein was reduced by insulin to the same extent after placebo and DHEA. Insulin sensitivity as expressed by the glucose infusion rate during the euglycemic clamp was similar after placebo and DHEA. Finally, the interstitial release of glycerol in adipose tissue was not significantly influenced by DHEA. Conclusions: Short-term oral DHEA replacement in women with adrenal insufficiency was not associated with measurable changes in total or regional substrate metabolism.

The Development of Ecotoxicological Criteria in Urban Catchments

1990 ◽  
Vol 22 (10-11) ◽  
pp. 173-179 ◽  
Author(s):  
A. D. Bascombe ◽  
J. B. Ellis ◽  
D. M. Revitt ◽  
R. B. E. Shutes
Keyword(s):  
Metal Uptake ◽  
Equilibrium Concentration ◽  
Mortality Rates ◽  
Toxicity Tests ◽  
Short Term ◽  
Test Conditions ◽  
Urban Catchments ◽  
Laboratory Bioassays ◽  
Concentration Levels

Metal uptake and mortality rates are determined for selected body areas of Gammarus pulex under both in-situ stream and laboratory test conditions. Metal equilibrium concentration levels are chieved in soft tissue within 5 to 6 weeks exposure in the field with four-to five-fold increases over background control levels noted for saturation levels in caged organisms at sites subject to sewer discharges. Laboratory bioassays yield short-term LC20 values in the order Pb>Cu>Zn, although there is little difference in metal toxicities over exposure periods of about one week. The controlled toxicity tests demonstrate a substantial short-term toxic enhancement over the in-situ field bioassays.

scholarly journals Analyzing Factors Affecting the Sustainability of Land Management Practices in Mecha Woreda, Northwestern Ethiopia

2021 ◽  
Vol 13 (13) ◽  
pp. 7007
Author(s):  
Habtamu Nebere ◽  
Degefa Tolossa ◽  
Amare Bantider
Keyword(s):  
Decision Making ◽  
Land Management ◽  
Land Degradation ◽  
Quantitative Data ◽  
Management Practices ◽  
Short Term ◽  
Factors Affecting ◽  
Decision Making Processes ◽  
Household Heads ◽  
The Impact

In Ethiopia, the practice of land management started three decades ago in order to address the problem of land degradation and to further boost agricultural production. However, the impact of land management practices in curbing land degradation problems and improving the productivity of the agricultural sector is insignificant. Various empirical works have previously identified the determinants of the adoption rate of land management practices. However, the sustainability of land management practices after adoption, and the various factors that control the sustainability of implemented land management practices, are not well addressed. This study analyzed the factors affecting the sustainability of land management practices after implementation in Mecha Woreda, northwestern Ethiopia. The study used 378 sample respondents, selected by a systematic random sampling technique. Binary logistic regression was used to analyze the quantitative data, while the qualitative data were qualitatively and concurrently analyzed with the quantitative data. The sustained supply of fodder from the implemented land management practices, as well as improved cattle breed, increases the sustainability of the implemented land management practices. While lack of agreement in the community, lack of enforcing community bylaws, open cattle grazing, lack of benefits of implemented land management practices, acting as barrier for farming practices, poor participation of household heads during planning and decision-making processes, as well as the lack of short-term benefits, reduce the sustainability of the implemented land management practices. Thus, it is better to allow for the full participation of household heads in planning and decision-making processes to bring practical and visible results in land management practices. In addition, recognizing short-term benefits to compensate the land lost in constructing land management structures must be the strategy in land management practices. Finally, reducing the number of cattle and practicing stall feeding is helpful both for the sustainability of land management practices and the productivity of cattle. In line with this, fast-growing fodder grass species have to be introduced for household heads to grow on land management structures and communal grazing fields for stall feeding.

scholarly journals Radioiodine in Differentiated Thyroid Carcinoma: Do We Need Diagnostic Pre-Ablation Iodine-123 Scintigraphy to Optimize Treatment?

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 553
Author(s):  
Elizabeth de Koster ◽  
Taban Sulaiman ◽  
Jaap Hamming ◽  
Abbey Schepers ◽  
Marieke Snel ◽  
...  
Keyword(s):  
Lymph Node ◽  
Lymph Node Metastasis ◽  
Thyroid Carcinoma ◽  
Treatment Success ◽  
Differentiated Thyroid Carcinoma ◽  
Whole Body ◽  
Thyroid Remnant ◽  
Node Metastasis ◽  
Unsuccessful Treatment

Changing insights regarding radioiodine (I-131) administration in differentiated thyroid carcinoma (DTC) stir up discussions on the utility of pre-ablation diagnostic scintigraphy (DxWBS). Our retrospective study qualitatively and semi-quantitatively assessed posttherapy I-131 whole-body scintigraphy (TxWBS) data for thyroid remnant size and metastasis. Findings were associated with initial treatment success after nine months, as well as clinical, histopathological, and surgical parameters. Possible management changes were addressed. A thyroid remnant was reported in 89 of 97 (92%) patients, suspicion of lymph node metastasis in 26 (27%) and distant metastasis in 6 (6%). Surgery with oncological intent and surgery by two dedicated thyroid surgeons were independently associated with a smaller remnant. Surgery at a community hospital, aggressive tumor histopathology, histopathological lymph node metastasis (pN1) and suspicion of new lymph node metastasis on TxWBS were independently associated with an unsuccessful treatment. Thyroid remnant size was unrelated to treatment success. All 13 pN1 patients with suspected in situ lymph node metastases on TxWBS had an unsuccessful treatment, opposite 19/31 (61%) pN1 patients without (p = 0.009). Pre-ablative knowledge of these TxWBS findings had likely influenced management in 48 (50%) patients. Additional pre-ablative diagnostics could optimize patient-tailored I-131 administration. DxWBS should be considered, especially in patients with pN1 stage or suspected in situ lymph node metastasis. Dependent on local surgical expertise, DxWBS is not recommended to evaluate thyroid remnant size.

scholarly journals Stimulation of mitochondrial calcium ion efflux by thiol-specific reagents and by thyroxine. The relationship to adenosine diphosphate retention and to mitochondrial permeability

1979 ◽  
Vol 182 (2) ◽  
pp. 455-464 ◽  
Author(s):  
E J Harris ◽  
M Al-Shaikhaly ◽  
H Baum
Keyword(s):  
Thyroid Hormones ◽  
Calcium Ion ◽  
Adenine Nucleotides ◽  
Adenosine Diphosphate ◽  
Ruthenium Red ◽  
Reduced Form ◽  
Factors Affecting ◽  
Ph Values ◽  
Rat Heart Mitochondria ◽  
The Relationship

Respiring rat heart mitochondria were loaded with Ca2+ and then treated with Ruthenium Red. The factors affecting the subsequent Ca2+-efflux were studied. Addition of rotenone or antimycin led to a decline of efflux except at pH values above 7.2, provided the load was less than about 80 nmol per mg of protein. Oligomycin reversed the effect of the respiratory inhibitors. Independently of respiration, efflux was stimulated by the uncoupler trifluoromethyltetrachlorbenzimadazole, by mersalyl and by thyroid hormones. The stimulated efflux could be diminished by ADP, with Mg2+ as cofactor if efflux was rapid. With respiration in progress, efflux could be stimulated by N-ethylmaleimide and 5,5′-dithiobis-(2-nitrobenzoate). The effects of mersalyl and of thyroid hormones could be diminished with dithiothreitol. In the absence of stimulating agents, the Ca2+ efflux was proportional to the load up to some critical amount, this critical amount was decreased by the agents. Thyroxine and mersalyl caused not only loss of Ca2+, but also simultaneous, but not necessarily proportional, loss of internal adenine nucleotides. Both efflux rates were kept at a low value by bongkrekic acid added before the stimulating agent. It is concluded that Ca2+ efflux is a measure of a permeability controlled by the binding of ADP (an Mg2+) to the inner membrane, and that this in turn depends on the maintenance of certain thiol gropus in a reduced form by a reaction that uses NADH and ATP and the energy-linked transhydrogenase.

Short-term Effects of Whole-Body Vibration on Functional Mobility and Flexibility in Healthy, Older Adults

2014 ◽  
Vol 37 (2) ◽  
pp. 58-64 ◽  
Author(s):  
Taishi Tsuji ◽  
Naruki Kitano ◽  
Kenji Tsunoda ◽  
Erika Himori ◽  
Tomohiro Okura ◽  
...  
Keyword(s):  
Older Adults ◽  
Whole Body Vibration ◽  
Functional Mobility ◽  
Whole Body ◽  
Short Term ◽  
Healthy Older Adults ◽  
Body Vibration ◽  
Short Term Effects

Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Adsorption Process ◽  
In Situ Polymerization ◽  
Selective Removal ◽  
Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

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