Variation of Organochlorine Residue Levels with Age in Gulf of St. Lawrence Harp Seals (Pagophilus groenlandicus)

1973 ◽  
Vol 30 (5) ◽  
pp. 595-600 ◽  
Author(s):  
R. F. Addison ◽  
S. R. Kerr ◽  
J. Dale ◽  
D. E. Sergeant
Keyword(s):  
Rank Correlation ◽  
Residue Level ◽  
Organochlorine Residue ◽  
Published Data ◽  
Age Changes ◽  
Pagophilus Groenlandicus ◽  
Proportional Increase ◽  
Residue Concentration ◽  
Residue Levels ◽  
Saguenay River

Blubber samples from 18 harp seals taken near the Saguenay River in the Gulf of St. Lawrence were analysed for DDT metabolites, PCBs, and dieldrin. The concentration of total DDT and metabolites [Formula: see text] ranged from 3.1 to 22.6 ppm, PCBs (as Aroclor® 1254) from 2 to 22 ppm, dieldrin from 0.1 to 0.3 ppm of blubber. Rank correlation of residue level and age indicated that significant portions of the [Formula: see text] and PCB variance could be assigned to increased residue levels with age. Within the [Formula: see text] group, DDE alone showed a strong proportional increase in concentration with age. Dieldrin concentration was not appreciably correlated with age. Among factors other than age, changes in blubber thickness did not account for any significant amount of the variance in blubber residue concentration. Examination of other published data suggested that parturition and/or lactation may cause reductions in blubber residue concentrations.

DDT Residues in Euphausiids in the Upper Estuary of the Gulf of St. Lawrence

1975 ◽  
Vol 32 (2) ◽  
pp. 310-314 ◽  
Author(s):  
D. D. Sameoto ◽  
D. C. Darrow ◽  
S. Guildford
Keyword(s):  
Significant Variation ◽  
Organochlorine Residue ◽  
Residue Levels ◽  
Meganyctiphanes Norvegica ◽  
Saguenay River ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

No significant variation was found in organochlorine residue levels between different stations in an area from the Saguenay River to the end of the Gaspé Peninsula in the Gulf of St. Lawrence for the euphausiids Thysanöessa raschii, T. inermis, and Meganyctiphanes norvegica. Significant differences were found between the concentration of organochlorine residues for M. norvegica and the Thysanöessa species, but there was no difference between the two Thysanöessa species.Significantly lower values for percent lipid were found in T. inermis and T. raschii between June 1973 and May 1974 samples, but the total amount of organochlorine residues did not change. This suggests that these species do not lose p,p′-DDT when they metabolize lipids for energy or the production of gonad material.

Comparison of organochlorine residue levels in the striped dolphin from western north Pacific, 1978–1979 and 1986

1990 ◽  
Vol 21 (9) ◽  
pp. 435-439 ◽  
Author(s):  
B.G. Loganathan ◽  
S. Tanabe ◽  
H. Tanaka ◽  
S. Watanabe ◽  
N. Miyazaki ◽  
...  
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Organochlorine Residue ◽  
Striped Dolphin ◽  
Residue Levels

Reproductive Rates of Harp Seals, Pagophilus groenlandicus (Erxleben)

1966 ◽  
Vol 23 (5) ◽  
pp. 757-766 ◽  
Author(s):  
D. E. Sergeant
Keyword(s):  
Sexual Maturity ◽  
Reproductive Rate ◽  
First Year ◽  
Published Data ◽  
Age Class ◽  
Adult Females ◽  
Pagophilus Groenlandicus ◽  
The Mean ◽  
Reproductive Rates ◽  
Lower Population

In less than a decade the mean age at sexual maturity of female harp seals of the Front, or northeastern Newfoundland population, decreased to 4 from [Formula: see text] years. Exploitation was heavy during this period and included a high proportion of seals older than 1 year. Females of the Gulf of St. Lawrence herd declined in mean age at sexual maturity over the same decade to 5 from nearly 6 years. Exploitation of this herd was lower, especially for animals older than their first year. Fertility of the adult females was likely higher in the more heavily exploited population. Published data on the White Sea population, which was reduced to low numbers, show reproduction at a lower mean age than for the present Front herd; for the Jan Mayen herd, of uncertain population status, about the same reproductive rate as the present Gulf herd. In most of the populations, samples of adult, whelped females showed the greatest number in the age-class about 1 year older than that first showing 100% of the females mature, as would be expected; however, samples from the Front herd showed dominance of an older age-class, suggesting that young adult females may to some extent segregate into separate groups. The immediate factors leading to increased reproductive rates at lower population densities were not elucidated.

scholarly journals Effects of maize residue and mineral nitrogen applications on maize yield in conservation-agriculture-based cropping systems of Southern Africa

2019 ◽  
Vol 35 (3) ◽  
pp. 322-335 ◽  
Author(s):  
W. Mupangwa ◽  
C. Thierfelder ◽  
S. Cheesman ◽  
I. Nyagumbo ◽  
T. Muoni ◽  
...  
Keyword(s):  
Grain Yield ◽  
Southern Africa ◽  
Cropping Systems ◽  
Conservation Agriculture ◽  
Maize Yield ◽  
Residue Level ◽  
N Fertilizer ◽  
Growing Seasons ◽  
Residue Biomass ◽  
Residue Levels

AbstractConservation agriculture (CA) and no-till (NT)-based cropping systems could address soil degradation and fertility decline in southern Africa. A multi-location and multi-year experiment was carried out between 2008 and 2014 to assess the effects of different levels of maize residue biomass (0, 2, 4, 6 and 8 t ha−1) and nitrogen (N) fertilizer (0, 30, 90 kg ha−1) on maize performance under no-tillage. In some sites, different (N) fertilizer levels were superimposed to test their effects on maize grain yield and leaf chlorophyll content under different maize residue biomass levels. The different residue levels had no significant effect on maize yield in most growing seasons. Maize residue cover increased grain yield in eight out of 39 site-years across the sites used. However, in some sites, maize yield decreased with increases in residue level in cropping seasons that had average to above average rainfall. At a few sites maize yield increased with increase in residue level. Seasonal rainfall pattern influenced the effect of different residue levels on grain yield at most sites. Nitrogen fertilizer increased maize yield regardless of the residue level applied. This study demonstrates that mulching with maize residues in CA/NT systems results in limited maize yield gains – at least within the first 6 years in different agro-ecological conditions of southern Africa.

Organochlorine residue levels in livers of birds of prey from Spain: Inter-species comparison in relation with diet and migratory patterns

2008 ◽  
Vol 153 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Barend van Drooge ◽  
Rafael Mateo ◽  
Íngrid Vives ◽  
Iris Cardiel ◽  
Raimon Guitart
Keyword(s):  
Organochlorine Residue ◽  
Birds Of Prey ◽  
Species Comparison ◽  
Residue Levels ◽  
Migratory Patterns

scholarly journals Molecular Testing for Plasmodium falciparum by Use of Serum or Plasma and Comparison with Microscopy and Rapid Diagnostic Testing in Febrile Nigerian Patients

2015 ◽  
Vol 53 (11) ◽  
pp. 3596-3600 ◽  
Author(s):  
Jesse J. Waggoner ◽  
Chika Okangba ◽  
Alisha Mohamed-Hadley ◽  
Martina I. Lefterova ◽  
Niaz Banaei ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Sensitivity And Specificity ◽  
Diagnostic Testing ◽  
Rank Correlation ◽  
Sample Volume ◽  
Nucleic Acid Amplification ◽  
Published Data ◽  
Molecular Testing ◽  
Content Type

Plasmodiumnucleic acids have been detected in serum and plasma, but there is little published data describing the diagnostic performance of malaria nucleic acid amplification tests (NAATs) using these specimen types. Previously, our group described a multiplex NAAT for the detection of dengue virus,Leptospira, andPlasmodiumspecies with a callout forP. falciparum(the DLM assay) that demonstrated sensitive detection ofP. falciparumfrom plasma samples during initial evaluation. In this study, we evaluated the sensitivity and specificity ofP. falciparumdetection in febrile Nigerian patients using the DLM assay, microscopy, and a rapid diagnostic test (BinaxNOW Malaria). Assay performances were compared using a composite reference, which was considered positive if malaria was detected by two or more methods. Serum (n= 182) or plasma (n= 148) from 317 patients was tested; the average sample volume was 70 μl (range, 5 to 300 μl). The sensitivity and specificity of the DLM assay were 97.1% and 93.5%, respectively. The sensitivity of the malaria rapid diagnostic test (98.1%) was similar to that of the DLM assay, and both proved significantly more sensitive than microscopy (79%;P< 0.0001). When analysis was limited to samples with ≥75 μl of serum or plasma, the sensitivity of the DLM assay improved to 99% and specificity was 97.5%. ForP. falciparumcases, cycle threshold values in the DLM assay correlated with the parasite density detected by microscopy (Spearman's rank correlation coefficient,P< 0.0001). In conclusion, malaria detection using the DLM assay on serum or plasma is more sensitive than and equal in specificity to microscopy in patients withP. falciparummalaria.

Organochlorine residue levels in human milk from Baghdad

1985 ◽  
Vol 35 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Muthanna A. Al-Omar ◽  
Samira J. Tawfiq ◽  
Nehla Al-Ogaily
Keyword(s):  
Human Milk ◽  
Organochlorine Residue ◽  
Residue Levels

scholarly journals Residues of streptomycin antibiotic in commercial layers in Abeokuta and Ibadan metropolis

2021 ◽  
Vol 31 (1) ◽  
pp. 130-134
Author(s):  
M. A. Dipeolu ◽  
A. J. Adebayo ◽  
O. M. Oke
Keyword(s):  
Human Consumption ◽  
Bacterial Diseases ◽  
Maximum Residue Level ◽  
Bacillus Subtilis Atcc ◽  
Liver And Kidney ◽  
Residue Concentration ◽  
Residue Levels ◽  
The Mean ◽  
Food Animals ◽  
Open Markets

Old layers sold for human consumption in six open markets in Abeokuta and Ibadan metropolis of Ogun and Oyo States of Nigeria were analyzed for the presence of residues of streptomycin antibiotic. One hundred and twenty samples comprising of muscle (thigh and breast), liver and kidney tissues were subjected to microbiological assay technique for the detection of residues of the antibiotic. The assay was done on antibiotic medium 5 agar with Bacillus subtilis (ATCC 6633) organism. Results showed that 34.17% of the sampled birds were positive for the presence of streptomycin antibiotic. The concentration of the residues ranged between 0.18µg/g and 0.91µg/g. The mean residue levels recorded among the organs are not significantly different (P>0.05). Some of the muscle samples recorded residue concentration levels higher than the W.H.O recommended maximum residue level for streptomycin antibiotic in muscle tissue of food animals. In view of the importance of antibiotics in the treatment of bacterial diseases in both human and animals, it is advocated that the use of these drugs in food animals be done judiciously.

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