Serodetection of Ehrlichia canis amongst dogs in central Namibia

Ehrlichia canis is a major pathogen in dogs throughout Africa, yet it has not been reported in Namibia. The aim of this study was to determine the seroprevalence of canine ehrlichiosis in central Namibia using the ImmunoComb assay (Biogal, Galed Laboratories). The study included 76 dogs that presented to the Rhino Park Veterinary Clinic in the north-western suburb of Khomasdal, Windhoek, Namibia, as well as 30 stray dogs from the Windhoek branch of the Society for the Prevention of Cruelty to Animals. Of the 106 dogs tested, 53.8% were seropositive at titres > 1:80. Dogs that presented with symptoms of E. canis infection had a significantly higher seroprevalence (86.6%) compared with apparently healthy dogs (41.6%) (P = 0.00). Location of habitation was significant (P < 0.017), with a high percentage of dogs exposed to E. canis living in the northern or north-western part of Windhoek. As the first study to serologically establish E. canis as a major pathogen in dogs in central Namibia, it is notable that the highest proportion of seropositive dogs came from low-income areas. Further investigation is necessary to describe the ecology of this important tick-borne pathogen of companion animals in Namibia.Peer reviewedEntomology and Plant Patholog

Model reactions and natural occurrence of furans from hypersaline environments

Volatile organic compounds like furan and its derivatives are important for atmospheric properties and reactions. In this work the known abiotic formation of furan from catechol under Fenton-like conditions with Fe3+ sulfate was revised by the use of a bispidine Fe2+ complex as a model compound for iron with well-known characteristics. While total yields were comparable to those with the Fe3+ salt, the bispidine Fe2+ complex is a better catalyst as the turnover numbers of the active iron species were higher. Additionally, the role of iron and pH is discussed in relation to furan formation from model compounds and in natural sediment and water samples collected from the Dead Sea and several salt lakes in Western Australia. Various alkylated furans and even traces of halogenated furans (3-chlorofuran and 3-bromofuran) were found in some Australian samples. 3-chlorofuran was found in three sediments and four water samples, whereas 3-bromofuran was detected in three water samples. Further, the emission of furans is compared to the abundance of several possible precursors such as isoprene and aromatic hydrocarbons as well as to the related thiophenes. It is deduced that the emissions of volatile organic compounds such as furans contribute to the formation of ultra-fine particles in the vicinity of salt lakes and are important for the local climate

Anatrichosoma sp. in the footpads of a cat: Diagnosis and pathology of Namibian case

Anatrichosoma species are an unusual group of zoonotic trichuroid nematodes. Due to limited knowledge of their life cycle and diagnostic challenges, anatrichosomiasis has been reported only 3 times in domestic animals. A short-haired cat from central Windhoek, Namibia, presented with ulceration, swelling, and sepsis on all four paws, a severe generalized lymphadenopathy and considerable invasive eosinophilia. Histological analysis revealed epidermal hyperplasia, with severe serocellular crusting on the skin surface. One specimen revealed a series of thick-walled eggs within nematode segments with a few sections containing eggs with bioperculate appearance which is compatible with the Aphasmid group of nematodes, more specifically, the genus Anatrichosoma. Ivermectin treatment completely cleared the condition. This is the first report of Anatrichosoma sp. in the Republic of Namibia, identified from a unique location in the capital, Windhoek.Peer reviewedEntomology and Plant Patholog

Data from: The fate of phosphorus fertilizer in Amazon soya bean fields

Fertilizer-intensive soya bean agriculture has recently expanded in southeastern Amazônia, and whereas intensive fertilizer use in the temperate zone has led to widespread eutrophication of freshwater ecosystems, the effects in tropical systems are less well understood. We examined the fate of fertilizer P by comparing P forms and budgets across a chronosequence of soya bean fields (converted to soya beans between 2003 and 2008) and forests on an 800 km2 soya bean farm in Mato Grosso, Brazil. Soya bean fields were fertilized with 50 kg P ha-1 yr-1 (30 kg P ha-1 y-1 above what is removed in crops). We used modified Hedley fractionation to quantify soil P pools and found increases in less-plant-available inorganic pools and decreases in organic pools in agricultural soils compared with forest. Fertilizer P did not move below 20 cm. Measurements of P sorption capacity suggest that while fertilizer inputs quench close to half of the sorption capacity of fast-reacting pools, most added P is bound in more slowly reacting pools. Our data suggest that this agricultural system currently has a low risk of P losses to waterways and that long time-scales are required to reach critical soil thresholds that would allow continued high yields with reduced fertilizer inputs

Spectroscopic monitoring of the jet in the symbiotic star MWC 560

We present the results of an intensive monitoring program of the jet absorptions in the symbiotic system MWC 560, obtained with the FEROS echelle spectrograph at the ESO 1.5 m Telescope. MWC 560 is a unique jet source because the line of sight lies practically parallel to the jet axis so that the outflowing gas is seen as absorption in the continuum of the accreting object, in the emission line spectrum of the accretion disk and temporary also in the spectrum of the red giant companion. Highly variable, blue-shifted jet absorption components, due to H

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