A new approach to modelling the dynamics of oospore germination in Plasmopara viticola

Oospores, the only overwintering structures of Plasmopara viticola, the causal agent of grapevine downy mildew, are the unique source of inoculum for primary infections in vineyards. We show that their germination dynamics depend on both climatic and endogenous factors. In particular, overwintering in controlled conditions suggests that low temperatures prolong the oospore germinability, while constant or gradually alternating water availability increases germination rates. However, wide fluctuations in germination percentage, observed both in naturally overwintered oospores, and under controlled conditions, indicate an important role for endogenous factors in the germination frequency. Ad hoc experimental assays and microscopic observations highlight an important role for calcium in the germination process. However, for a profound understanding of the biological mechanisms underlying oospore germination, mathematical models of the germination dynamics are needed. But, classical differential models of germination dynamics are, with current knowledge, prohibitive due both to the complexity of the underlying processes and knowledge incompleteness. Then, we propose a hybrid method derived from the integration of qualitative differential models and fuzzy systems.     

Serological prevalence of canine respiratory coronavirus in southern Italy and epidemiological relationship with canine enteric coronavirus.

Canine respiratory coronavirus (CRCoV) has been detected in dogs suffering from respiratory disease and is thought to be involved in canine infectious respiratory disease (CIRD) complex. Canine enteric coronavirus (CECoV) is a widespread pathogen of dogs, responsible for mild to severe diarrhea in pups. The purpose of this study was to establish the seroprevalence of CRCoV in Italy and its relationship to CECoV type II seroprevalence. The age and year of sample collection from seropositive dogs was also assessed. Of adult domestic dogs, 23.3% had antibodies to CRCoV, compared with 86.1% with antibodies to CECoV. Amongst a population of kenneled pups, 4.0% had antibodies to CRCoV, and 97.0% had antibodies to CECoV.     

Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions

In recent years, policy‐makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non‐target species that are unknowingly released alongside intentionally‐introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan‐continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.