Search

The West African coast is vulnerable to natural hazards and human interventions. Although various measures have been taken at different scales, mostly at the local level, there is a need to improve management at the regional level. We examine these actions and possible solutions from different perspectives and provide conclusions and recommendations on the integration of solutions to improve coastal management. From North West Mauritania to across the Gulf of Guinea a system of coastal zoning that can be managed holistically is encouraged. The development of holistic planning is seen as a sustainable approach to management that seeks to link users/processes together rather than focus on a single particular issue and solution. Strengthening, monitoring, promoting the observation network and generalising open data centralisation and exchange for a better understanding of coastal dynamics and pressures is encouraged. There is a need for capacity building, expertise and federative actions. Furthermore, the need to identify and involve not only stakeholders, but also communities and scientists with multilevel inputs. All must agree on coordinated plans to achieve stakeholder objectives, using an approach adapted to the multi-spatial scale (e.g at the scale of sediment cells, integrating from the sources of sediment in river basins to their redistribution along the coast, perturbed by climate changes and anthropic stresses), so that only regional solutions are appropriate and will be effective. These must follow sustainable strategies with a multi-temporal sequenced solution and anticipate changes, or adaptive solutions using solutions in synergy with different time frames as well as managing natural and human systems responsibly. A plan that considers changes in coastal systems and anticipates impacts and adapts plans accordingly will be key.

The objective of this work was to characterize autochthonous bacteriophages and to determine their lytic activity on Staphylococcus aureus. Six phages were isolated from dairy barn flush water through enrichment cultures with three S. aureus strains. All phages were characterized by DNA digestion by restriction enzymes and sequencing of the DNA fragment encoding endolysin. Each phage was tested against 100 S. aureus strains isolated from bovine mastitis and from dairy products using the lysis-plate method. The sequences of the endolysin gene were highly conserved, with nucleotide similarity higher than 99% among the isolated phages. Three domains involved in the recognition and lysis of the bacterial cell wall were identified. Two bacteriophages isolated from the dairy barns present high lytic activity on S. aureus, on a wide range of host strains, indicating their potential for studies on phage therapy in dairy cattle or as a biological control agent for dairy products. Resumo: O objetivo deste trabalho foi caracterizar bacteriófagos autóctones e determinar sua atividade lítica em Staphylococcus aureus. Seis fagos foram isolados de água de lavagem de pisos de estábulos por meio do enriquecimento de cultura com três estirpes de S. aureus. Todos os fagos foram caracterizados pela digestão do DNA com enzimas de restrição e pelo sequenciamento do fragmento de DNA que codifica a endolisina. Cada fago foi testado contra 100 estirpes de S. aureus isoladas de casos de mastite bovina e de produtos lácteos pelo método de lise em placa. Sequências do gene de endolisina apresentaram alta conservação, com mais de 99% de similaridade a nível do nucleotídeo entre os fagos isolados. Foram identificados três domínios envolvidos no reconhecimento e na lise da parede celular bacteriana. Dois bacteriófagos isolados de estábulos apresentam alta atividade lítica em S. aureus, em ampla gama de estirpes, o que indica seu potencial para estudos de fagoterapia em gado leiteiro ou como agente de controle biológico para produtos lácteos.

Increased body weight (BW) gain during the juvenile period leads to early maturation of the reproductive neuroendocrine system. We investigated whether a nutritional regimen that advances the onset of puberty leads to alterations in the hypothalamic neuropeptide Y (NPY) circuitry that are permissive for enhanced gonadotropin-releasing hormone (GnRH) secretion. It was hypothesized that NPY mRNA and NPY projections to GnRH and kisspeptin neurons are reduced in heifers that gain BW at an accelerated rate, compared with a lower one, during the juvenile period. Heifers were weaned at approximately 4 mo of age and fed diets to promote relatively low (0.5 kg/day; low gain [LG]) or high (1.0 kg/day; high gain [HG]) rates of BW gain until 8.5 mo of age. Heifers that gained BW at a higher rate exhibited greater circulating concentrations of leptin and reduced overall NPY expression in the arcuate nucleus. The proportion of GnRH neurons in close apposition to NPY fibers and the magnitude of NPY projections to GnRH neurons located in the mediobasal hypothalamus were reduced in HG heifers. However, no differences in NPY projections to kisspeptin neurons in the arcuate nucleus were detected between HG and LG heifers. Results indicate that a reduction in NPY innervation of GnRH neurons, particularly at the level of the mediobasal hypothalamus, occurs in response to elevated BW gain during the juvenile period. This functional plasticity may facilitate early onset of puberty in heifers.

International audience