Prevalence of equine parvovirus-hepatitis in healthy broodmares in Ontario, Canada.

Equine parvovirus-hepatitis (EqPV-H) was first reported from the serum and liver tissue of a horse diagnosed with Theiler's disease in the United States in 2018. Theiler's disease, also known as equine serum hepatitis, is a severe hepatitis with fulminant hepatic necrosis. The disease has most frequently been reported following the administration of equine-origin biological products; however, it has also been reported in in-contact horses with no prior biologic administration. EqPV-H has been detected in clinically healthy horses in North America (USA, Canada), Europe (Germany, Austria, Slovenia), Asia (China, South Korea), and South America (Brazil). Previous prevalence studies conducted worldwide have shown the presence of EqPV-H DNA in serum or plasma ranging from 3.2 to 19.8%. This study investigated the prevalence of EqPV-H DNA in 170 healthy broodmares of various breeds located on 37 farms in southern Ontario, Canada. The occurrence of EqPV-H infection was determined by quantitative PCR for EqPV-H DNA in serum samples. The effects of age, breed, season, pregnancy status, and equine herpesvirus-1 (EHV-1) vaccination history on EqPV-H status were also investigated. There was a prevalence of 15.9% (27/170) with viral loads of EqPV-H ranging from detectable to 2900 copies/mL. Statistical analysis showed that increasing age was a significant factor in the detection of EqPV-H DNA. Neither breed, season, pregnancy status, nor EHV-1 vaccination history was significant in predicting EqPV-H infection status.

L'hépatite à parvovirus équin (EqPV-H) a été signalée pour la première fois à partir du sérum et du tissu hépatique d'un cheval diagnostiqué avec la maladie de Theiler aux États-Unis en 2018. La maladie de Theiler, également connue sous le nom d'hépatite sérique équine, est une hépatite sévère avec nécrose hépatique fulminante. La maladie a été le plus souvent rapportée à la suite de l'administration de produits biologiques d'origine équine; cependant, il a également été signalé chez des chevaux en contact sans administration préalable de produit biologique. EqPV-H a été détecté chez des chevaux cliniquement sains en Amérique du Nord (États-Unis, Canada), en Europe (Allemagne, Autriche, Slovénie), en Asie (Chine, Corée du Sud) et en Amérique du Sud (Brésil). Des études de prévalence antérieures menées dans le monde entier ont montré la présence d'ADN EqPV-H dans le sérum ou le plasma allant de 3,2 à 19,8 %. Cette étude a examiné la prévalence de l'ADN EqPV-H chez 170 poulinières en bonne santé de différentes races situées dans 37 fermes du sud de l'Ontario, au Canada. La survenue d'une infection par EqPV-H a été déterminée par PCR quantitative pour l'ADN d'EqPV-H dans des échantillons de sérum. Les effets de l'âge, de la race, de la saison, de l'état de grossesse et des antécédents de vaccination contre l'herpèsvirus équin-1 (EHV-1) sur le statut EqPV-H ont également été étudiés. Il y avait une prévalence de 15,9 % (27/170) avec des charges virales d'EqPV-H allant de détectable à 2900 copies/mL. L'analyse statistique a montré que l'augmentation de l'âge était un facteur significatif dans la détection de l'ADN EqPV-H. Ni la race, ni la saison, ni l'état de grossesse, ni les antécédents de vaccination contre l'EHV-1 n'étaient significatifs pour prédire l'état de l'infection par l'EqPV-H.(Traduit par Docteur Serge Messier).

Adaptation of Partial Mutual Information from Mixed Embedding to Discrete-Valued Time Series.

A causality analysis aims at estimating the interactions of the observed variables and subsequently the connectivity structure of the observed dynamical system or stochastic process. The partial mutual information from mixed embedding (PMIME) is found appropriate for the causality analysis of continuous-valued time series, even of high dimension, as it applies a dimension reduction by selecting the most relevant lag variables of all the observed variables to the response, using conditional mutual information (CMI). The presence of lag components of the driving variable in this vector implies a direct causal (driving-response) effect. In this study, the PMIME is appropriately adapted to discrete-valued multivariate time series, called the discrete PMIME (DPMIME). An appropriate estimation of the discrete probability distributions and CMI for discrete variables is implemented in the DPMIME. Further, the asymptotic distribution of the estimated CMI is derived, allowing for a parametric significance test for the CMI in the DPMIME, whereas for the PMIME, there is no parametric test for the CMI and the test is performed using resampling. Monte Carlo simulations are performed using different generating systems of discrete-valued time series. The simulation suggests that the parametric significance test for the CMI in the progressive algorithm of the DPMIME is compared favorably to the corresponding resampling significance test, and the accuracy of the DPMIME in the estimation of direct causality converges with the time-series length to the accuracy of the PMIME. Further, the DPMIME is used to investigate whether the global financial crisis has an effect on the causality network of the financial world market.

Trace elements in edible tissues of elasmobranchs from the North Aegean Sea (Eastern Mediterranean) and potential risks from consumption.

Trace elements have the potential to bioaccumulate in marine organisms and to biomagnify towards the upper levels of marine trophic webs, resulting in a range of negative effects on organisms. Elasmobranchs are highly susceptible to bioaccumulation of trace metals, while their consumption by humans is increasing worldwide. Therefore, it is important to monitor the trace metal content in the edible tissues of elasmobranchs. This work reveals the content of 12 trace metals in the edible tissues of 10 elasmobranch species caught in Greek waters. Levels above the permissible limits for Hg and Pb were found in some species, while analysis of the lifetime consumption risk for adults and children using the Target Hazard Quotient (THQ), revealed a high risk for two of the most toxic substances on the priority list for substances, namely As and Hg. These are preliminary results, and further research is required to understand better the issue.

Infection of young foals with Equine Parvovirus-Hepatitis following a fatal non-biologic case of Theiler's disease.

Theiler's disease (TD) is a (sub-)acute hepatitis in adult horses and one of the most common causes of acute hepatic failure. Recent findings indicate that equine parvovirus hepatitis (EqPV-H) likely causes TD and that its transmission occurs via iatrogenic and/or natural routes. Following the death of an EqPV-H positive mare with TD, close-contact mares and foals in the same paddock were monitored to evaluate if there was any evidence of EqPV-H. For this purpose, the serum of close contact horses was examined 6 and 42 days after the mare's death for the presence of EqPV-H DNA and changes in liver-associated serum biochemical parameters. The foals had higher EqPV-H viral loads than the mares. Apart from the mare that was euthanized, none of the horses included in this study showed signs of severe disease and nor did they have particularly elevated liver enzymes. Nucleotide sequence analysis revealed no major differences between the viral DNA detected in the serum of the dead mare and any of the in-contact horses. In conclusion, our data confirmed previous findings that horizontal transmission of EqPV-H may occur through close contact between horses.

Investigating long range correlation in DNA sequences using significance tests of conditional mutual information.

This study exploits the use of Markov chain order estimation from symbol sequences of systems exhibiting long memory or long range correlations (LRC), such as DNA sequences. In the presence of limited sequence length, LRC chain can be approximated by a high order Markov chain. For the order estimation, the parametric significance test of conditional mutual information IC(m) is applied, found in an earlier work to be suitable for high order estimation. Here, it is computationally optimized applying an iterative algorithm for calculating IC(m) at increasing order m, enabling the analysis of long symbol sequences of high Markov chain order or LRC. The simulation study shows that when the true order is reasonably small, the estimated order saturates at the true order with the increase of the symbol sequence length, while when the true order is very large or the chain has LRC, the estimated order increases logarithmically with the symbol sequence length. The order estimation shows a different dependence on the DNA sequence length for bacteria, the plant Arabidopsis thaliana and the human chromosome, indicating a different long memory structure in their DNA.