35 research outputs found
Recommended from our members
Increased and sex-selective avian predation of desert locusts Schistocerca gregaria treated with Metarhizium acridum
The entomopathogenic fungus Metarhizium acridum in oil-based formulations (Green Muscle® (GM)) is a biopesticide for locust control lacking side-effects on biodiversity, unlike chemical insecticides. Under controlled conditions, GM-treated locusts and grasshoppers attract predators, a complementary advantage in locust control. We assessed avian predation on a population of desert locusts in northern Niger aerially sprayed operationally with GM with 107 g viable conidia ha-1. Populations of adult locusts and birds and vegetation greenness were assessed simultaneously along two transects from 12 days before until 23 days after treatment. Common kestrels Falco tinnunculus and lanners F. biarmicus were the predominant avian predators. Regurgitated pellets and prey remains were collected daily beneath “plucking posts” of kestrels. Locusts started dying five days post-spray and GM had its maximum effect one-two weeks after the spray, with 80% efficacy at day 21. After spraying, bird numbers increased significantly (P<0.05) concurrent with decreasing desert locust densities. Locust numbers decreased significantly (P<0.001) with both time since spraying and decreasing greenness. Before spraying, kestrel food remains under plucking posts accounted for 34.3 ±13.4 prey items day-1, of which 31.0 ±11.9 were adult desert locusts (90.3%), reducing post-spray to 21.1 ±7.3 prey items day-1, of which19.5 ±6.7 were adult desert locusts (92.5%), attributable to decreased use of the plucking-posts by the kestrels rather than an effect of the spray. After spraying, kestrels took significantly (P<0.05) more larger female (75–80%) than smaller male (20–25%) locusts. Avian predation probably enhanced the impact of the GM on the desert locust population, especially by removing large adult females. No direct or indirect adverse side-effects were observed on non-target organisms including locust predators such as ants and birds. These substantial ecological advantages should also be considered when choosing between conventional chemical and biopesticide-based locust control
Differences in anti-malarial activity of 4-aminoalcohol quinoline enantiomers and investigation of the presumed underlying mechanism of action
International audienc
Breastmilk donations: Bacteriological assessment, analysis of causes of non-compliance and suggestions for improvement
International audienceA total of 1099 breastmilk donations received by the milk bank at the Amiens University Hospital from January to June 2016 were assessed for bacteriological contamination according to French regulations. This consisted in enumerating the total aerobic flora before and after heat treatment as well as the specific enumeration of coagulase-positive staphylococci. Results above the mandatory limits for at least one of these parameters were found in 25.9% of the donations, resulting in the destruction of approximately one-quarter of the volume of the donations (similar to 195 L). This is a huge loss in both economic and health-related terms for neonates, especially for pre-terms. To identify ways to improve the bacteriological assessment results and reduce the percentage of discarded milk, an analysis of the causes was conducted. The two main causes of non-compliance were the detection of a cultivable aerobic flora after heat treatment and the presence of coagulase-positive staphylococci above the mandatory limit (11.7% and 11.2% of the tested donations, respectively). Bacillus spp. were the leading cause of post-heat treatment non-compliance. Therefore, the implementation of better environmental control could help reduce this kind of contamination. As for samples harboring coagulase-positive staphylococci, a further detection of toxins using molecular biology techniques could help discriminate actual health-hazardous donations that have to be destroyed while enabling the use of toxin-negative donations. Nevertheless, the economic viability of this proposal needs to be further assessed because these techniques are costly. Finally, a change in breastmilk dilutions used to enumerate the total aerobic flora to better reflect the actual level of these bacteria in the milk was proposed. Indeed, the comparison of various combinations of milk dilutions led to the conclusion that the association of the 1/10 and 1/100 dilutions was the best compromise between technical ease of enumeration and ensuring the safety of the donations. Implementing these suggestions would help reduce the rate of non-compliance and give better access to safe breastmilk donations for neonates. (C) 2018 Elsevier Masson SAS. All rights reserved
The decline of an urban Hooded Vulture Necrosyrtes monachus population in Dakar, Senegal, over 50 years
As in many West African cities, in Dakar Hooded Vultures Necrosyrtes monachus have always been characteristic urban scavengers. The recent decline of Hooded Vultures in other parts of Africa, mainly eastern Africa, has been the reason in 2015 for up-listing of its status by the IUCN in the Red List of Threatened Species to Critically Endangered. As the Hooded Vulture is still common in the Lower Casamance, Senegal, in the Western Region of The Gambia and in Guinea-Bissau, without clear signs of a recent decrease, a survey of its current status in Dakar was undertaken and compared with historical data over the past 50 years. A strong decrease of >85% was noted from 3 000 individuals in 1969 to 400 in 2016. This decline is on the high end of the decline noticed over much of its range but in striking contrast with the apparently stable populations along the West African coast more to the south (The Gambia to Guinea). Likely causes are (1) exponential urbanisation resulting in loss of feeding sites and reduced food availability, (2) increased poisoning of feral dogs with strychnine sulphate due to an upsurge of rabies and (3) increased disappearance of suitable trees for nesting and roosting.Keywords: cutting of trees, Hooded Vulture, Necrosyrtes monachus, poisoning, population estimate, slaughterhouse sanitation, urban developmen
CRT device for the analysis of Mirabelle pictures
Outlines the software requirements that Mirabelle's CRT system must meet and discusses the set of FORT
New ferrocenic pyrrolo[1,2-a]quinoxaline derivatives: Synthesis, and in vitro antimalarial activity – Part II
International audienc