Core-derived historical records of suspended sediment origin in a mesoscale mountainous catchment: the River Bléone, French Alps

Purpose

Quantifying suspended sediment fluxes and dynamics across mountains, and identifying the origin of sediment in severely eroded areas, are of primary importance for the management of water resources. This contribution aims to generalise previous results from suspended sediment fingerprinting obtained during 2007?C2009 in a mesoscale Alpine catchment (the Bléone River; 905?km²) in France, and to assess variability in sediment sources throughout the second half of the twentieth century.

Materials and methods

Sediment fingerprinting, based on elemental geochemistry and radionuclide measurements, was conducted on a sediment core collected in an alluvial floodplain at the basin outlet. This technique was combined with hydro-sedimentary time-series to reconstruct the origin of suspended sediment deposited at this location over the last 50?years.

Results and discussion

Interpretation of sedimentation based on historical hydrological databases corroborates core dating obtained with ¹³⁷Cs and ²¹⁰Pb_xs activity measurements. Black marls and (marly) limestone sources provided the main fraction of sediment throughout the sequence (40 and 22?%, respectively). However, we also found evidence for the occurrence of major floods carrying large quantities of sediment originating from Quaternary deposits and conglomerates (25 and 16?%, respectively). The variability of sediment sources throughout the sequence may reflect the spatial variability of rainfall within the catchment, which in turn reflects its origin. However, the relatively homogeneous sediment composition throughout the sequence confirms that core-derived information is representative of widespread flood events.

Conclusions

These results are consistent with those obtained in previous studies. They also outline the need to take into account the entire grain size range of fine sediment in order to provide an overall picture of sediment sources and transfers within highly erosive catchments. This study also emphasizes the importance of using archival data to validate the results of sediment fingerprinting studies conducted during short contemporary monitoring programmes, and to extend fingerprinting of sediment sources over longer time-scales which include large and widespread floods.     

No evidence of Bartonella quintana but detection of Acinetobacter baumannii in head lice from elementary schoolchildren in Paris

The human body louse is the only known vector of Bartonella quintana. However, the presence of this bacterium has recently been detected in the head lice of homeless individuals and Nepalese slum children. Previous studies have reported the isolation of Acinetobacter baumannii from the body lice of homeless individuals. An epidemiological survey including 74 schools was conducted between 2008 and 2009 in Paris. After a first visual examination, the hair of children with suspected pediculosis was combed with a fine-tooth comb to collect live adult head lice. Molecular studies were performed on randomly selected DNA samples to detect B. quintana and A. baumannii by specific quantitative real-time PCR. Among a collection of 288 DNA samples, B. quintana was not detected, but A. baumannii was detected in 95 DNA samples (33%). Further study is needed to determine the significance of the finding of A. baumannii in head lice.     

Laparoscopic-assisted colopexy and sterilization in male dogs: short-term results and physiologic consequences

Objective: To describe laparoscopic‐assisted colopexy and sterilization, and evaluate outcome and effects in healthy male dogs. Study Design: Experimental study. Animals: Male Beagle dogs (n=7). Methods: A laparoscopic‐assisted, extracorporeally sutured colopexy, and sterilization by ligation and section of the testicular vessels and ductus deferens were evaluated 11 weeks after surgery. Ex vivo tensile tests were performed on the colopexy sites and loss of testicular function was assessed by monitoring serum testosterone, and by ultrasonographic and histologic examinations of the testes. Systemic inflammation and potential iatrogenic colonic functional disorders were investigated by monitoring serum C‐reactive protein (CRP) in the perioperative period and from a sulfapyridine (SP) kinetic profile obtained before and 10 weeks after surgery. Results: No intraoperative complications were recorded and clinical outcome was considered fair in all dogs. A mean tensile force of 42 N was required to disrupt colopexies. No relevant postoperative increase in CRP concentrations or changes in SP kinetics were observed. Testicular function was lost. Conclusions: Laparoscopic‐assisted colopexy achieved adhesion of the colon to the abdominal wall and testicular endocrine function and spermatogenesis were eliminated by laparoscopic castration.     

Risk factors for Listeria monocytogenes contamination in French laying hens and broiler flocks

The objective of this study was to identify potential risk factors for Listeria monocytogenes contamination in French poultry production. Eighty-four flocks of layer hens kept in cages and 142 broiler flocks were included in this study. For each production type, a questionnaire was submitted to farmers and fecal samples were taken to assess the L. monocytogenes status of the flocks during a single visit to the farm. Two logistic regression models (specific to each production) were used to assess the association between management practices and the risk of L. monocytogenes contamination of the flock. The prevalence of L. monocytogenes-positive flocks was 30.9% (95% CI: 21.0; 40.9) and 31.7% (95% CI: 24.0; 39.4) for cage-layers and broiler flocks, respectively. For layer flocks, the risk of L. monocytogenes contamination was increased when pets were present on the production site. When droppings were evacuated by conveyor belt with deep pit storage, the risk of L. monocytogenes contamination decreased significantly. Feed meal was found to be associated with a higher risk of L. monocytogenes contamination than feed crumb. For broiler flocks, the risk of L. monocytogenes contamination was increased when farmers did not respect the principle of two areas (clean and dirty) at the poultry house entrance. A first disinfection by thermal fogging and the absence of pest control of the poultry house before the arrival of the next flock was found to increase the risk of contamination. When litter was not protected during storage and when farm staff also took care of other broiler chicken houses, the risk of L. monocytogenes contamination increased significantly. In the case of the watering system, nipples with cups were found to decrease the risk of contamination.     

Palatal sclerotherapy for the treatment of intermittent dorsal displacement of the soft palate in 51 standardbred racehorses

This retrospective study evaluated the efficacy and side effects of palatal sclerotherapy in standardbred racehorses suspected to have intermittent dorsal displacement of the soft palate (IDDSP). Fifty-one horses were treated with multiple endoscopically guided injections of 3% sodium tetradecyl sulfate in the soft palate. Two groups were identified: those that had respiratory noises during exercise (n = 27) and those that did not (n = 24). Treatment was well-tolerated. Furthermore, horses significantly reduced their racing times for the last 400 m compared with their times before treatment and even when their times were compared to the mean times for horses in the same race. In conclusion, palatal sclerotherapy appears to be a suitable alternative therapeutic option for horses suspected to have IDDSP.     

Mastocytaemia in cats: prevalence, detection and quantification methods, haematological associations and potential implications in 30 cats with mast cell tumours

The significance of mastocytaemia in cats is different from that in dogs because it appears exclusively associated with mast cell neoplasia. The prevalence of mastocytaemia was 0.05% of all feline submissions to a private laboratory and 43% in cats with mast cell neoplasia. None of 30 healthy cats had mastocytaemia. There was no sex bias or significant age difference between mastocytaemic and non-mastocytaemic cats with mast cell tumours (MCT). Buffy coat (BC) examination was the best screening method for detection of mastocytaemia but direct blood film examination was more accurate for quantifying degree of mastocytaemia. BC examination should be performed in all cases of suspected/known mast cell neoplasia as mastocytaemia was missed on nearly 30% of occasions when direct film examination only was used. Mastocytaemia was associated with decreased haematocrit (HCT) but not with other haematological parameters. Mastocytaemic cats can survive significant lengths of time (up to 27 months) even when splenectomy is not performed.     

Efficacy of fungicides with various modes of action in controlling the early stages of an Erysiphe necator-induced epidemic

BACKGROUND: Limiting the use of fungicides is due to become an important issue in managing Erysiphe necator (Schwein) Burrill infections in vineyards. The authors determined how three fungicides currently used by vine growers could be managed to control the early stages of an E. necator‐induced epidemic. RESULTS: Leaf‐disc bioassays and field experiments suggested that the protectant quinoxyfen induced minor disruption in E. necator development, but compounds with protectant and curative properties (tebuconazole and trifloxystrobin) caused significant, although different, disruption during E. necator‐induced epidemics. Bioassays showed that each of the antifungals were most effective at different stages of fungal development, tebuconazole before sporulation and trifloxystrobin after sporulation of the colonies. Results from the bioassay also highlighted likely occurrences in the field, where several stages of fungal development are encountered simultaneously. CONCLUSION: The present findings were complementary: leaf‐disc tests showed when the fungicides were most effective at inhibiting E. necator infection cycles; the field trial provided results in terms of incidence and severity of disease on bunches without reference to the pathogenic cycle development. A protection strategy combining the different types of fungicide under study is suggested. Copyright © 2010 Society of Chemical Industry