Risks to bees from dusts emitted at sowing of coated seeds: concerns, risk assessment and risk management

contribution to session V Honey bee poisoning incidents and monitoring scheme

A shortcut method for sexing juvenile European sea bass, Dicentrarchus labrax L.

The objective of this study was to develop a rapid and effective method of sexing juvenile sea bass with minimum labour and material.To this end, the gonad squash mount technique was applied along with macroscopic techniques for sexing a large number of experimental fish at the age of 215-275 days post fertilization (p.f.). At this age, 90% of the 3894 fish could be unambiguously sexed by macroscopic examination of their gonads, whereas the remaining proportion was identified using squash mount preparations (10%). The accuracy of the observations was measured up to classical histology procedures. Undifferentiated gonads accounted for 0.1% of the total population only.The application of the squashmount technique holds out the prospect of considerable improvement in the efficiency and rapidity of current sexing techniques in sea bass

Technical and Environmental Performances of Wood Combustion in Domestic Turbo Boilers: Influence of Operating Parameters

International audienc

Modification of population sex ratios by domestication and artificial selection in the European sea bass (Dicentrarchus labrax L.)

absen

Can we obtain monosex sea bass populations through selective breeding?

absen

Quantitative genetic variation for post-stress cortisol and swimming performance in growth-selected and control populations of European sea bass (Dicentrarchus labrax)

Sea bass is a major species in Mediterranean aquaculture, and is now being subject to selective breeding programmes for faster growth. In terrestrial species, it was demonstrated that fast growth may be linked to a correlated degradation of fitness traits. In this experiment, we evaluated 600 young sea bass from a factorial mating of 76 sires and 13 dams. The sires were from four genetic groups, wild (W), domesticated (D), and selected for growth (2 groups, M and P). The 600 offspring were submitted to two acute confinement stress challenges at 6 weeks intervals, and plasma cortisol at one hour post stress was measured. The same fish were also submitted to two swimming challenges at a 5 days interval, where the maximum sustained swimming speed (Umax) of each fish was evaluated. Parentage was assessed by genotyping of 12 microsatellites. 554 fish had both valid parentage and phenotypes. Cortisol had a low repeatability (r = 0.30 between the two successive measurements) while repeatability was moderate for Umax (r = 0.62). However, genetic correlations between successive measurements were very high (> 0.96) for both traits, indicating that successive measurements were related to the same trait. Heritability was moderate for mean post-stress cortisol (h2 = 0.34 ± 0.09) and Umax (h2 = 0.48 ± 0.08). When Umax was expressed in m.s− 1, it was negatively correlated to cortisol (rA = − 0.48 ± 0.08) and weakly correlated to body weight (rA = 0.12 ± 0.16), but figures changed when it was expressed in Body Lengths.s− 1 (h2 = 0.55 ± 0.08, rA = − 0.10 ± 0.19 with cortisol and rA = − 0.64 ± 0.07 with body weight, respectively). Cortisol was moderately negatively correlated with body weight (rA = − 0.36 ± 0.18). The four lines did not differ for cortisol or Umax, but when Umax was expressed in BL.s− 1 it tended to be lower in the two selected lines — which were also significantly larger. However, this is likely due to a phenotypic decrease of relative Umax with increasing body size. We conclude that selection for growth and/or domestication should not impact maximum sustained swimming speed in the European sea bass, but may tend to favour animals with low cortisol responsiveness. These traits could be used to orientate functional capabilities other than productivity in sea bass.Statement of relevance: We estimate heritability of cortisol stress response and (for the first time) in European sea bass, as well as their correlations with growth. We show moderate correlations, and no correlated response to selection for growth. We also provide methods to evaluate these traits on large number of fishes. This can be useful to monitor and design breeding programmes

Longitudinal atrophy in early Braak regions in preclinical Alzheimer's disease

A major focus of Alzheimer's disease (AD) research has been finding sensitive outcome measures to disease progression in preclinical AD, as intervention studies begin to target this population. We hypothesize that tailored measures of longitudinal change of the medial temporal lobe (MTL) subregions (the sites of earliest cortical tangle pathology) are more sensitive to disease progression in preclinical AD compared to standard cognitive and plasma NfL measures. Longitudinal T1-weighted MRI of 337 participants were included, divided into amyloid-β negative (Aβ−) controls, cerebral spinal fluid p-tau positive (T+) and negative (T−) preclinical AD (Aβ+ controls), and early prodromal AD. Anterior/posterior hippocampus, entorhinal cortex, Brodmann areas (BA) 35 and 36, and parahippocampal cortex were segmented in baseline MRI using a novel pipeline. Unbiased change rates of subregions were estimated using MRI scans within a 2-year-follow-up period. Experimental results showed that longitudinal atrophy rates of all MTL subregions were significantly higher for T+ preclinical AD and early prodromal AD than controls, but not for T− preclinical AD. Posterior hippocampus and BA35 demonstrated the largest group differences among hippocampus and MTL cortex respectively. None of the cross-sectional MTL measures, longitudinal cognitive measures (PACC, ADAS-Cog) and cross-sectional or longitudinal plasma NfL reached significance in preclinical AD. In conclusion, longitudinal atrophy measurements reflect active neurodegeneration and thus are more directly linked to active disease progression than cross-sectional measurements. Moreover, accelerated atrophy in preclinical AD seems to occur only in the presence of concomitant tau pathology. The proposed longitudinal measurements may serve as efficient outcome measures in clinical trials