The role of Mycoplasma bovis in bovine respiratory disease outbreaks in veal calf feedlots

To assess the prevalence and relative importance of Mycoplasma bovis among the pathological agents implicated in bovine respiratory disease (BRD), we surveyed 135 veal calves from nine feedlots in eastern France during naturally occurring outbreaks of respiratory disease. Occurrence of respiratory pathogens, M. bovis, bovine viral diarrhoea (BVD) virus, bovine respiratory syncytial (BRS) virus and parainfluenza-3 (PI3) virus was investigated by seroconversion and isolation of bacteria and viruses from broncho-alveolar fluids. M. bovis and pathogenic respiratory bacteria were isolated in eight of the nine feedlots, and from 106 and 32, respectively, of the 135 tested animals. Seroconversion to PI3 virus occurred in four lots. BVD and BRS viruses were detected in eight and one lot, respectively. M. bovis was the most frequently isolated aetiologic agent in these BRD outbreaks, spreading early and widely throughout the affected units (60-100% rate of isolation and seroconversion). These results stress the importance of M. bovis in the BRD complex.     

Frequency and distribution of foot lesions identified during cattle hoof trimming in the Province of Antioquia,Colombia (2011–2016)

Tropical Animal Health and Production - Lameness is a severe welfare problem in cattle and has a detrimental effect on longevity, productivity, and reproductive performance. This study aimed to...     

Non‐spherical pearl layers in the Polynesian ‘black‐lipped’ Pinctada margaritifera: The non‐nacreous deposits compared to microstructure of the shell growing edge

Cultivated pearls frequently exhibit morphological irregularities making obvious that mineral deposition was irregularly distributed onto nucleus surface. Taking advantage of experimental cultivations with short durations (from 10 days to few months), these irregular deposits predating occurrence of the nacre were investigated in Polynesian pearls by biochemical characterizations and a series of physical methods. Diversity in the resulting data suggests that various in‐depth alterations of the biomineralization mechanism may have occurred during the grafting process, leading to diversity in the biochemical pathways to nacreous deposition. This allows a precise discussion of current views about pearl formation. The “reversed shell theory” is formally disproved through point to point comparison with development of the shell growing edge. Similarity of pearl formation with “regeneration” or “shell repair” is also discussed, emphasizing the differences between these concepts.     

Determination of Mycoplasma bovis susceptibilities against six antimicrobial agents using the E test method

The objective of this study was to determine the susceptibility of Mycoplasma bovis against six antibiotics using the E test methodology. Fifty-eight isolates of M. bovis originating from 55 affected cattle were evaluated. Specimen originated from: lung tissue, synovial fluid, tracheo-bronchial wash, milk, and external or inner ear discharge. Antimicrobial agents tested were azythromycin, clindamycin, erythromycin, enrofloxacin, spectinomycin and tetracycline. The E test strips were placed on the surface of Hayflick plates on which organism suspension was spread. Plates were incubated at 35 degrees C in a candle jar for 72 h. MICs were then read by determining where the growth inhibition zone intersected with the MIC scale on the strip. M. bovis Donetta isolate was used as a control. All MICs were >256 microg/ml for erythromycin. MIC50 and MIC90 obtained for azythromycin were 3 and >256 microg/ml, respectively. MIC50 and MIC90 obtained for tetracycline were 4 and 8 microg/ml, respectively. MIC50 and MIC90 obtained for spectinomycin were 2 and >1021 microg/ml, respectively. MIC50 and MIC90 obtained for clindamycin were 0.19 and >256 microg/ml, respectively. MIC50 and MIC90 obtained for enrofloxacin were 0.19 and 0.25 microg/ml, respectively. Resistance was not associated with the specimen source except for azythromycin. M. bovis susceptibilities were easily determined by the E test which demonstrated the efficacy of enrofloxacin and the acquired resistance to tetracycline, spectinomycin, azythromycin and clindamycin.     

Correction to: Coupling landscape graph modeling and biological data: a review

Landscape Ecology - In the original publication of the article, the sixth author name has been misspelt. The correct name is given in this Correction. The original article has been corrected.     

Settlement behavior of American lobster (Homarus americanus): effect of female origin and developmental temperature

The benthic settlement success of American lobster (Homarus americanus) postlarvae is a key factor in population dynamics, with the temperature being a key factor. Given the spatial distribution of the species, its pelagic larvae probably encounter various thermal zones during development. Little information is available on the ability of lobster larvae to acclimate to temperature or if this ability varies among geographic areas. The main objectives of this study were to characterize (i) the settlement behavior of the postlarvae in relation to (a) temperature during larval development and (b) the geographic origin of the maternal parent and (ii) the behavioral response of postlarvae with different thermal histories in the presence/absence of a thermocline. Results did not support the hypothesis of thermal adaptation among local populations, as settlement behavior of postlarvae did not differ among females from different geographic regions. In contrast, larval survival and settlement behavior and postlarval energetic conditions varied with development temperature. Behavioral plasticity in the benthic settlement was observed in relation to temperature structure of the experimental water column. This study suggests that there may be links between development temperature and the natural variability in survival and settlement of American lobsters. Findings emphasize the need for an integrated approach in lobster recruitment studies with the inclusion of behavior in dispersion models.     

Trends and controls of Holocene floodplain sedimentation in the Rhine catchment

Holocene floodplain sedimentation in the Rhine catchment is controlled by human and climate impacts. Intricate river behaviour modifies the fluvial response to the external impacts making cause–effect analysis difficult, especially on large spatial scales. To better understand the relative importance and interdependencies of external and internal controls, temporally resolved floodplain sedimentation rates are established using three different methods: i) floodplain storage studies on the trunk stream, ii) depth/age-analysis of overbank deposits from different parts of the catchment and iii) cumulative frequency distributions of ¹⁴C-ages from floodplain deposits from various parts of the catchment. The applied methodology strongly differs with the available temporal resolution and the size of the corresponding catchment. All three methods show a strong increase in sedimentation rate for more recent periods that can be linked to increasing human impact. Evidences for climate impacts and intricate river behaviour are less clear and hindered by insufficient temporal resolution of the currently available data.     

Method for determining nitrogenous heterocycle compounds in wine

Qualitative and quantitative analyses of N-heterocycle compounds were conducted by using a liquid-liquid extraction followed by additional chemical silica gel purification and injection into a gas chromatographic (GC) column coupled to a nitrogen-phosphorus detector (NPD). The purified extract fraction was investigated by GC-NPD and by GC-mass spectrometry. The compounds identified and quantified in wines were 2,4,5-trimethyloxazole, 2,4-dimethylthiazole, and 4-methylthiazole by GC-NPD and both 2-acetylthiazole and 2-acetyl-2-thiazoline by GC-MS. The procedure was used to analyze different wines and gave reliable and reproducible results.