scholarly journals Combined exposure to sublethal concentrations of an insecticide and a fungicide affect feeding, ovary development and longevity in a solitary bee

2018 ◽  
Vol 285 (1885) ◽  
pp. 20180887 ◽  
Author(s):  
Fabio Sgolastra ◽  
Xavier Arnan ◽  
Riccardo Cabbri ◽  
Gloria Isani ◽  
Piotr Medrzycki ◽  
...  
Keyword(s):  
Physiological Condition ◽  
Premature Death ◽  
Ovary Development ◽  
Solitary Bee ◽  
Pesticide Mixture ◽  
Low Concentrations ◽  
Chemical Residues ◽  
Neonicotinoid Insecticide ◽  
Highly Correlated ◽  
Ovary Maturation

Pollinators in agroecosystems are often exposed to pesticide mixtures. Even at low concentrations, the effects of these mixtures on bee populations are difficult to predict due to potential synergistic interactions. In this paper, we orally exposed newly emerged females of the solitary bee Osmia bicornis to environmentally realistic levels of clothianidin (neonicotinoid insecticide) and propiconazole (fungicide), singly and in combination. The amount of feeding solution consumed was highest in bees exposed to the neonicotinoid, and lowest in bees exposed to the pesticide mixture. Ovary maturation and longevity of bees of the neonicotinoid and the fungicide treatments did not differ from those of control bees. By contrast, bees exposed to the pesticide mixture showed slow ovary maturation and decreased longevity. We found a synergistic interaction between the neonicotinoid and the fungicide on survival probability. We also found an interaction between treatment and emergence time (an indicator of physiological condition) on longevity. Longevity was negatively correlated to physiological condition only in the fungicide and the mixture treatments. Delayed ovary maturation and premature death imply a shortened nesting period (highly correlated to fecundity in Osmia ). Our findings provide a mechanism to explain the observed dynamics of solitary bee populations exposed to multiple chemical residues in agricultural environments.

Measurement of gonadotropins in dried blood spots

1994 ◽  
Vol 40 (3) ◽  
pp. 448-453 ◽  
Author(s):  
C M Worthman ◽  
J F Stallings
Keyword(s):  
Luteinizing Hormone ◽  
Filter Paper ◽  
Clinical Studies ◽  
Follicle Stimulating Hormone ◽  
Dried Blood Spots ◽  
Blood Spots ◽  
Low Concentrations ◽  
Serial Sampling ◽  
Highly Correlated ◽  
Blood Spot

Abstract We describe direct immunofluorometric assays for luteinizing hormone (hLH) and follicle-stimulating hormone (hFSH) in fingerstick blood spots dried on filter paper, based on modifications of commercially available kits. Determinations are made from 2.5-mm-diameter discs (3 microL of dried blood) punched out from blood spot standards and samples. Sample dose detection limits of the assays (IU/L) are 0.26 for LH and 0.13 for FSH, with mean interassay CVs of 11.6% (LH) and 7.8% (FSH) at low concentrations. Analytical recoveries of added hormone averaged 100% for LH and 95% for FSH. Clinical studies showed that values for blood spots (x) and directly assayed plasma (y) are highly correlated, so that results from blood spots can be converted directly to plasma equivalents, as follows: yLH = 0.07 + 1.90 xLH, and yFSH = 0.424 + 2.207 xFSH. These gonadotropins are stable in blood spots for at least a year under refrigeration; LH for at least 8 weeks and FSH 6 weeks at 22 degrees C; and both hormones for a week at 37 degrees C. These methods thus allow self-sampling, serial sampling, and mailing of specimens.

Results compared for tricyclic antidepressants as assayed by liquid chromatography and enzyme immunoassay.

1988 ◽  
Vol 34 (11) ◽  
pp. 2348-2351 ◽  
Author(s):  
R C Dorey ◽  
S H Preskorn ◽  
P K Widener
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Dose Adjustment ◽  
Tricyclic Antidepressants ◽  
Therapeutic Drug ◽  
Low Concentrations ◽  
High Detection ◽  
High Detection Limit ◽  
Highly Correlated

Abstract The tricyclic antidepressants amitriptyline, nortriptyline, imipramine, and desipramine in serum of patients taking one of the drugs were quantified in two laboratories by high-performance liquid chromatography (HPLC) and enzyme-multiplied immunoassay (EMIT; Syva). Results for split samples were highly correlated, but EMIT gave higher results in most cases, and the slopes of the correlation lines for each analyte were greater than 1. Detection limits for the two procedures were such that 18% of the EMIT results for the drug(s) were considered negative, as compared with 4% of the HPLC results. Additional assay of desmethyl or hydroxy antidepressant metabolites by HPLC did not explain the higher EMIT results. The relatively high detection limit for EMIT greatly limits its use in therapeutic drug monitoring, where low concentrations of tricyclic antidepressants are as important as high ones for dose adjustment or determination of compliance. Other problems with EMIT measurement of tricyclic antidepressants are discussed.

scholarly journals Nontransferrin-bound iron in plasma from hemochromatosis patients: effect of phlebotomy therapy

Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1416-1419 ◽  
Author(s):  
OI Aruoma ◽  
A Bomford ◽  
RJ Polson ◽  
B Halliwell
Keyword(s):  
Iron Overload ◽  
Binding Capacity ◽  
Radical Reactions ◽  
Iron Binding ◽  
Total Plasma ◽  
Free Radical Reactions ◽  
Low Concentrations ◽  
Idiopathic Hemochromatosis ◽  
Highly Correlated ◽  
Iron Binding Capacity

Abstract Plasma from patients with iron overload resulting from idiopathic hemochromatosis contains nontransferrin-bound iron, measurable by the bleomycin, assay. During venesection therapy, the concentration of bleomycin iron declines in a way highly correlated with plasma ferritin concentrations. Even when patients had been venesected to give very low total plasma iron concentrations and high transferrin iron-binding capacity, bleomycin-detectable iron was still present at low concentrations. Bleomycin-detectable iron can stimulate damaging free radical reactions, and its persistence in plasma even after prolonged venesection might contribute to the tissue damage that results from iron overload.

scholarly journals Organic nitrate and secondary organic aerosol yield from NO<sub>3</sub> oxidation of β-pinene evaluated using a gas-phase kinetics/aerosol partitioning model

2009 ◽  
Vol 9 (4) ◽  
pp. 1431-1449 ◽  
Author(s):  
J. L. Fry ◽  
A. Kiendler-Scharr ◽  
A. W. Rollins ◽  
P. J. Wooldridge ◽  
S. S. Brown ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Oxidation Mechanism ◽  
Organic Aerosol ◽  
Anthropogenic Source ◽  
Organic Nitrate ◽  
Organic Nitrates ◽  
Gas Phase Kinetics ◽  
Low Concentrations ◽  
Dry Conditions ◽  
Highly Correlated

Abstract. The yields of organic nitrates and of secondary organic aerosol (SOA) particle formation were measured for the reaction NO3+β-pinene under dry and humid conditions in the atmosphere simulation chamber SAPHIR at Research Center Jülich. These experiments were conducted at low concentrations of NO3 (NO3+N2O5<10 ppb) and β-pinene (peak~15 ppb), with no seed aerosol. SOA formation was observed to be prompt and substantial (~50% mass yield under both dry conditions and at 60% RH), and highly correlated with organic nitrate formation. The observed gas/aerosol partitioning of organic nitrates can be simulated using an absorptive partitioning model to derive an estimated vapor pressure of the condensing nitrate species of pvap~5×10−6 Torr (6.67×10−4 Pa), which constrains speculation about the oxidation mechanism and chemical identity of the organic nitrate. Once formed the SOA in this system continues to evolve, resulting in measurable aerosol volume decrease with time. The observations of high aerosol yield from NOx-dependent oxidation of monoterpenes provide an example of a significant anthropogenic source of SOA from biogenic hydrocarbon precursors. Estimates of the NO3+β-pinene SOA source strength for California and the globe indicate that NO3 reactions with monoterpenes are likely an important source (0.5–8% of the global total) of organic aerosol on regional and global scales.

Do capital breeders like Atlantic herring (Clupea harengus) exhibit sensitive periods of nutritional control on ovary development and fecundity regulation?

2010 ◽  
Vol 67 (1) ◽  
pp. 16-27 ◽  
Author(s):  
James Kennedy ◽  
Jon Egil Skjæraasen ◽  
Richard D.M. Nash ◽  
Anders Thorsen ◽  
Aril Slotte ◽  
...  
Keyword(s):  
Food Availability ◽  
Clupea Harengus ◽  
Sensitive Period ◽  
Ovary Development ◽  
Atlantic Herring ◽  
Energy Reserves ◽  
Skipped Spawning ◽  
Capital Breeder ◽  
Low K ◽  
Ovary Maturation

A laboratory study was undertaken to investigate whether Northeast Atlantic herring ( Clupea harengus ), i.e., Norwegian spring-spawning herring, exhibit a “sensitive period” during the feeding season in which ovary development is particularly susceptible to food availability and (or) energy reserves. Groups of herring received similar amounts of food over the restricted summer – early autumn feeding season but the food availability was varied temporally between groups. The herring, an extreme capital breeder, did not exhibit a sensitive period, as there was no difference in fecundity or ovary maturation between groups. However, individuals that did not reach a Fulton’s condition factor (K) above 0.70 during the feeding season were less likely to begin ovary maturation. Those below this threshold showing ovary development began later and had a higher intensity of atresia than fish in better condition. To maximize fecundity, females recruited significantly more oocytes than they could support through to spawning, thus the oocytes were subsequently down-regulated. Some would have skipped spawning in the coming spawning season; these fish had a very low K. Taken together, this study demonstrates that this capital breeder has developed a suite of reproductive strategies to synchronize the production of the highest number of eggs energetically possible.

Response of yellow poplar (Liriodendrontulipifera L.) seedling shoot growth to low concentrations of O3, SO2, and NO2

1984 ◽  
Vol 14 (1) ◽  
pp. 150-153 ◽  
Author(s):  
M. J. Mahoney ◽  
J. M. Skelly ◽  
B. I. Chevone ◽  
L. D. Moore
Keyword(s):  
Shoot Growth ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Height Growth ◽  
Yellow Poplar ◽  
Shoot Height ◽  
Low Concentrations ◽  
Highly Correlated

Six-week-old yellow poplar (Liriodendrontulipifera L.) seedlings from one half-sib family were exposed to various combinations of 0.07 ppm O3, 0.06 ppm SO2, and 0.10 ppm NO2 6 h daily for 35 consecutive days. Ozone and SO2 alone did not suppress total shoot elongation compared with control seedlings after the 5-week fumigation period, whereas the combinations of O3 + SO2, SO2 + NO2, or O3 + SO2 + NO2 significantly reduced total shoot height 51, 64, and 51%, respectively. Of the pollutant combinations, SO2 + NO2 most severely inhibited the rate of height growth with this effect initially occurring after only 2 weeks of fumigation. The dry weight of seedlings exposed to O3 + SO2, SO2 + NO2, or O3 + SO2 + NO2 were significantly less than plants exposed to no pollutants, O3, or SO2. Total shoot height growth was highly correlated with seedling dry weight (r = 0.97)

scholarly journals Organic nitrate and secondary organic aerosol yield from NO<sub>3</sub> oxidation of <i>β</i>-pinene evaluated using a gas-phase kinetics/aerosol partitioning model

2008 ◽  
Vol 8 (5) ◽  
pp. 18039-18089 ◽  
Author(s):  
J. L. Fry ◽  
A. Kiendler-Scharr ◽  
A. W. Rollins ◽  
P. J. Wooldridge ◽  
S. S. Brown ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Oxidation Mechanism ◽  
Organic Aerosol ◽  
Anthropogenic Source ◽  
Organic Nitrate ◽  
Organic Nitrates ◽  
Gas Phase Kinetics ◽  
Low Concentrations ◽  
Dry Conditions ◽  
Highly Correlated

Abstract. The yields of organic nitrates and of secondary organic aerosol (SOA) particle formation were measured for the reaction NO3+β-pinene under dry and humid conditions in the atmosphere simulation chamber SAPHIR at Research Center Jülich. These experiments were conducted at low concentrations of NO3 (NO3+N2O5<10 ppb) and β-pinene (peak~15 ppb), with no seed aerosol. SOA formation was observed to be prompt and substantial (~50% mass yield under both dry conditions and at 60% RH), and highly correlated with organic nitrate formation. The observed gas/aerosol partitioning of organic nitrates can be simulated using an absorptive partitioning model to derive an estimated vapor pressure of the condensing nitrate species of pvap~5×10−6 Torr (6.67×10−4 Pa), which constrains speculation about the oxidation mechanism and chemical identity of the organic nitrate. Once formed the SOA in this system continues to evolve, resulting in measurable aerosol volume decrease with time. The observations of high aerosol yield from NOx-dependent oxidation of monoterpenes provide an example of a significant anthropogenic source of SOA from biogenic hydrocarbon precursors. Estimates of the NO3+β-pinene SOA source strength for California and the globe indicate that NO3 reactions with monoterpenes are likely an important source (0.5–8% of the global total) of organic aerosol on regional and global scales.

Sensitive salivary estradiol assay for monitoring ovarian function

1990 ◽  
Vol 36 (10) ◽  
pp. 1769-1773 ◽  
Author(s):  
C M Worthman ◽  
J F Stallings ◽  
L F Hofman
Keyword(s):  
Ovarian Function ◽  
Clinical Applications ◽  
Serum Estradiol ◽  
Assay Sensitivity ◽  
Sample Concentration ◽  
Low Concentrations ◽  
Reliable Detection ◽  
Highly Correlated ◽  
Serial Samples ◽  
Free Estradiol

Abstract Measurement of steroids in saliva has excited interest because of the numerous potential clinical applications; noninvasive, convenient sampling; and apparently accurate reflection of the concentrations of physiologically active unbound steroid in the circulation. Although assays of saliva for several steroid hormones are available and widely used, assays for salivary estradiol are not, primarily because of methodological limitations. By modifying a commercially available kit for serum estradiol, our laboratory has developed a procedure that is sensitive, highly specific, and reliable for measuring salivary estradiol. Assay sensitivity is 0.5 fmol (0.14 pg; sample concentration 1.3 pmol/L) with a mean interassay CV of 10.8% at low concentrations. Clinical studies showed that values for serum and saliva are highly correlated (P less than 0.001), and demonstrated reliable detection of estradiol peaks during normal ovulatory cycles in serial samples from 15 women. Salivary estradiol peaked at 5.4 (SD 1.9) pmol/L on cycle day 14.4 (SD 3.2), 1.2 (SD 0.8) days before ovulation detected by ultrasound. This assay may be particularly helpful in investigating ovarian function and free estradiol in women at various stages of the reproductive cycle.

scholarly journals Chronic oral exposure to field-realistic pesticide combinations via pollen and nectar: effects on feeding and thermal performance in a solitary bee

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Celeste Azpiazu ◽  
Jordi Bosch ◽  
Elisa Viñuela ◽  
Piotr Medrzycki ◽  
Dariusz Teper ◽  
...  
Keyword(s):  
Pesticide Exposure ◽  
Sublethal Effects ◽  
Synergistic Effects ◽  
Oral Exposure ◽  
Solitary Bee ◽  
Laboratory Studies ◽  
Sugar Syrup ◽  
Pesticide Regulation ◽  
Ovary Maturation ◽  
Pollinator Declines

Abstract Pesticide use is one of the main causes of pollinator declines in agricultural ecosystems. Traditionally, most laboratory studies on bee ecotoxicology test acute exposure to single compounds. However, under field conditions, bees are often chronically exposed to a variety of chemicals, with potential synergistic effects. We studied the effects of field-realistic concentrations of three pesticides measured in pollen and nectar of commercial melon fields on the solitary bee Osmia bicornis L. We orally exposed females of this species throughout their life span to 8 treatments combining two neonicotinoid insecticides (acetamiprid, imidacloprid) and a triazole fungicide (myclobutanil) via pollen and sugar syrup. We measured pollen and syrup consumption, longevity, ovary maturation and thermogenesis. Pesticide intake was three orders of magnitude higher via syrup than pollen. At the tested concentrations, no synergistic effects emerged, and we found no effects on longevity and ovary maturation. However, all treatments containing imidacloprid resulted in suppressed syrup consumption and drastic decreases in thoracic temperature and bee activity. Our results have important implications for pesticide regulation. If we had measured only lethal effects we would have wrongly concluded that the pesticide combinations containing imidacloprid were safe to O. bicornis. The incorporation of tests specifically intended to detect sublethal effects in bee risk assessment schemes should be an urgent priority. In this way, the effects of pesticide exposure on the dynamics of bee populations in agroecosystems will be better assessed.

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