Conception d'un équipement de détection automatique du comportement d'oestrus des truies élevées en groupe

[Notes_IRSTEA]bibl. [Departement_IRSTEA]EAA [TR1_IRSTEA]EAA2-NOVAPROCESS, Conception de systèmes d'équipements complexes pour l'agro-industrieFor automatic oestrus detection, a computer registers the presence of sows near a boar pen. During the trials the value of the registration depends on animal and environment. To determine the oestrus with the registration, two methods of calculation were used. The results obtained with the neural network computation are significatively better and take in consideration animal effect end environment.La conception d'un équipement de détection automatique des oestrus de truies élevées en groupe est présentée. Le principe de base est l'analyse des fréquences de passage des truies à proximité du verrat. Les expérimentations ont été réalisées dans deux environnements physiques différents et ont permis la comparaison de deux méthodes de traitement de l'information "fréquence de passage". Les résultats mettent en évidence les avantages de la méthode à base de réseau de neurones, qui intègre dans la phase d'apprentissage les effets bande et environnement

Recent species in old Islands : the origin of introduced populations of Litoria aurea (Anura : Hylidae) in New Caledonia and Wallis

New Caledonia is a megadiverse tropical island in the southwest Pacific, however, inhabited by only one species of amphibian, Litoria aurea (Hylidae). We used both molecular (CO1 and ND4 gene sequencing) and morphometric data to explore its geographical origin and timing of colonisation. We tested whether this species arrived through transoceanic dispersal before human arrival in the island, or recently through anthropogenic introduction. We found a weak phylogeographical structure within this species, and lower haplotype diversity in New Zealand, New Caledonia and Wallis compared to Australia. No significant genetic differentiation was found between pairs of populations in New Caledonia and Wallis, or between pairs of population from these two islands. We observed a high level of morphometric differentiation between Australian and island populations, and a low level of morphometric differentiation between island populations. Our results support an Australian origin for insular frogs. The possibility of a trans-marine dispersal from Australia to New Caledonia and/or Wallis in-between the Eocene and the Pleistocene cannot be favoured, given the low level of genetic differentiation. Our results are consistent with a recent human introduction, most likely during European times. Our data support the historical absence of amphibians in the old island New Caledonia, and is consistent with the new biogeographical paradigm that this island was totally re-colonized after emergence in Eocene. More studies are necessary to explain the success of this frog in oceanic islands, where it is widespread and abundant, compared to Australia, where it is declining

A new insight into the dissociating effect of strontium on bone resorption and formation.

Calcium phosphates are widely used as biomaterials and strontium (Sr) is known to have the ability to modify the bone balance towards osteosynthesis. In the present study we investigated the capacity of Sr-substituted sol-gel calcium phosphate to modify the expression of genes and proteins involved in extracellular matrix synthesis by primary bone cells. We first determined the most effective concentration of strontium using human primary bone cells. Sol-gel biphasic calcium phosphate (BCP) powders were then synthesised to obtain release of the optimal concentration of strontium. Finally, human osteoblasts obtained from explant cultures were cultured in the presence of sol-gel BCP, Sr-substituted BCP (5% Sr-substituted BCP, corresponding to a release of 5 × 10−5 M [Sr2+] under the culture conditions (BCP5%)) and medium containing strontium chloride (SrCl2). Viability, proliferation, cell morphology, protein production and protein activity were studied. We demonstrated that 5 × 10−5 M SrCl2 and BCP5% increased the expression of type I collagen and SERPINH1 mRNA and reduced the production of matrix metalloproteinases (MMP-1 and MMP-2) without modifying the levels of the tissue inhibitors of MMPs (TIMPs). Thus strontium has a positive effect on bone formation

The effect of zinc on hydroxyapatite-mediated activation of human polymorphonuclear neutrophils and bone implant-associated acute inflammation

Hydroxyapatite (HA) is widely used as coating biomaterial for prosthesis metal parts and as bone substitute. The release of HA particles induces an inflammatory response and, if uncontrolled, could result in implant loss. At the inflamed site, the polymorphonuclear cells (PMNs) represent the earliest phagocytic cells that predominate the cellular infiltrate. We have recently proposed that HA wear debris activate polymorphonuclear cells (PMNs) initiating and/or amplifying thereby the acute inflammatory response. Previous studies have shown that activation of monocytes by HA could be modulated by supplementing this latter with the divalent cation, Zinc. The purpose of this work was to investigate the modulation of PMNs activation following exposure to zinc-substituted HA. Our study demonstrate that addition of zinc to HA particles resulted in decreased levels of the pro-inflammatory mediator interleukin-8 (IL-8) and the matrix metallo-proteinase-9. We also show that these changes involve IL-8 receptors (CXCR-1 and CXCR-2)