25 research outputs found
First assessment of the comparative toxicity of ivermectin and moxidectin in adult dung beetles: Sub-lethal symptoms and pre-lethal consequences
Among macrocyclic lactones (ML), ivermectin (IVM) and moxidectin (MOX) potentially affect all
Ecdysozoan species, with dung beetles being particularly sensitive. The comparative effects of IVM
and MOX on adult dung beetles were assessed for the first time to determine both the physiological
sub-lethal symptoms and pre-lethal consequences. Inhibition of antennal response and ataxia
were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed
effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from
concentration-response curves (IC50, as the concentration of each ML where the antennal response is
inhibited by half; and pLC50, as the quantity of ingested ML where partial paralysis was observed by half
of treated individuals) from concentration-response curves. Both sub-lethal and pre-lethal symptoms
obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles.
Values of LOEC, IC50 and pLC50 obtained for IVM and MOX evaluated in an environmental context
indicate that MOX, despite needing more time for its elimination in the faeces, would be half as harmful
to dung beetles as IVM. This approach will be valuable to clarify the real impact of MLs on dung beetle
health and to avoid the subsequent environmental consequences
Pyrethroid treatment of cattle for tsetse control: Reducing its impact on dung fauna
Background: African trypansomiases of humans and animals can be controlled by attacking the vectors,various species of tsetse fly. Treatment of cattle with pyrethroids to kill tsetse as they feed is the most cost-effective method. However, such treatments can contaminate cattle dung, thereby killing the fauna which disperse the dung and so play an important role in soil fertility. Hence there is a need to identify cost-effective methods of treating cattle with minimal impact on dung fauna.
Methodology/Principal Findings: We used dung beetles to field bioassay the levels of dung contamination following the use of spray and pour-on formulations of deltamethrin, applied to various parts of the body of cattle in Zimbabwe. Results suggested that dung was contaminated by contact with insecticide on the body surface as the cattle defecated, and by ingestion of insecticide as the cattle
licked themselves. Death of dung beetles was reduced to negligible levels by using only the spray and applying it to the legs and belly or legs alone, i.e., places where most tsetse feed.
Conclusion/Significance: The restricted applications suitable for minimising the impact on dung fauna have the collateral benefits of improving the economy and convenience of cattle treatments for tsetse control. The demonstration of collateral benefits is one of the surest ways of promoting environmentally friendly procedures
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Determination of the prebiotic activity of wheat arabinogalactan peptide (AGP) using batch culture fermentation
Purpose
To test the prebiotic activity of wheat arabinogalactan-peptide (AGP), which is a soluble dietary fibre composed of arabinogalactan polysaccharide linked to a 15-residue peptide, which accounts for up to 0.4% of the dry weight of wheat flour.
Methods
The prebiotic activity of AGP prepared from white wheat flour was tested using in-vitro fermentation by colonic bacteria in automated pH controlled anaerobic stirred batch cultures and compared to fructooligosaccharide (FOS) and wheat flour arabinoxylan (AX). Bacterial populations were measured using fluorescence in-situ hybridisation (flow-FISH) and short-chain fatty acid (SCFA) concentrations were measured using HPLC.
Results
Fermentation of AGP resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate after 24 h of fermentation.
Conclusions
These results were comparable to those obtained with AX and confirm the prebiotic potential of AGP. Furthermore, fermentation of a mixture of AGP and AX was faster compared to the single substrates and more similar to FOS, indicating that combinations of fermentable carbohydrates with different structures are potentially more effective as prebiotics than single substrates
Macrocheles species (Acari: Macrochelidae) associated with human corpses in Europe
The biology of macrochelid mites might offer new venues for the interpretation of the environmental conditions surrounding human death and decomposition. Three human corpses, one from Sweden and two from Spain, have been analysed for the occurrence of Macrochelidae species.
Macrocheles muscaedomesticae females were associated with a corpse that was found in a popular beach area of southeast Spain. Their arrival coincides with the occurrence of one of their major carrier species, the filth fly Fannia scalaris, the activity of which peaks during mid-summer. M. glaber specimens were collected from a corpse in a shallow grave in a forest in Sweden at the end of summer, concurrent with the arrival of beetles attracted by odours from the corpse. M. perglaber adults were sampled from a corpse found indoors in the rural surroundings of Granada city, Spain. The phoretic behaviour of this species is similar to that of M. glaber, but being more specific to Scarabaeidae and Geotrupidae dung beetles, most of which favour human faeces.
M. muscaedomesticae is known from urban and rural areas and poultry farms; M. glaber from outdoors, particularly the countryside; while M. perglaber from outdoor, rural, and remote, potentially mountainous locations.
M. muscaedomesticae and M. perglaber are reported for the first time from the Iberian Peninsula. This is the first record of M. perglaber from human remains
Macrocheles species (Acari: Macrochelidae) associated with human corpses in Europe
The biology of macrochelid mites might offer new venues for the interpretation of the environmental conditions surrounding human death and decomposition. Three human corpses, one from Sweden and two from Spain, have been analysed for the occurrence of Macrochelidae species.
Macrocheles muscaedomesticae females were associated with a corpse that was found in a popular beach area of southeast Spain. Their arrival coincides with the occurrence of one of their major carrier species, the filth fly Fannia scalaris, the activity of which peaks during mid-summer. M. glaber specimens were collected from a corpse in a shallow grave in a forest in Sweden at the end of summer, concurrent with the arrival of beetles attracted by odours from the corpse. M. perglaber adults were sampled from a corpse found indoors in the rural surroundings of Granada city, Spain. The phoretic behaviour of this species is similar to that of M. glaber, but being more specific to Scarabaeidae and Geotrupidae dung beetles, most of which favour human faeces.
M. muscaedomesticae is known from urban and rural areas and poultry farms; M. glaber from outdoors, particularly the countryside; while M. perglaber from outdoor, rural, and remote, potentially mountainous locations.
M. muscaedomesticae and M. perglaber are reported for the first time from the Iberian Peninsula. This is the first record of M. perglaber from human remains
The Selling of Primary Care 2015
The role of undergraduate medical education in creating, perpetuating, and potentially solving the physician shortage in adult primary care has been debated for years, but often the discussions revolve around overly simplistic notions of supply and demand. The supply is curtailed, it is said, because the work is hard and the pay is low relative to other career options. Missing is a recognition that medical schools make choices in developing primary care learning environments that profoundly affect student perceptions of this career. Emerging developments in healthcare, including the transformation of academic health centers into integrated health systems that enter into risk-based contracts, may provide an opportunity to re-direct discussions about primary care. More schools may begin to recognize that they can control the quality of primary care teaching environments, and that doing so will help them achieve excellence in education and compete in the new marketplace. The selling of primary care to medical schools may be the first step in primary care selling itself to medical students