Carp oedema virus disease outbreaks in Czech and Slovak aquaculture

This work describes the first confirmed cases of carp oedema virus disease (CEVD) in Slovakia and the Czech Republic and the phylogenetic analysis of Czech and Slovak carp oedema virus (CEV) isolates. Four cases of disease outbreak in the Czech Republic are described, the oldest dating from mid-May 2013 and one case from Slovakia dating from May 2019. In all cases, virus presence was confirmed using nested PCR. PCR products were sequenced and compared with 357-bp nucleotide sequences encoding the CEV P4a protein in GenBank. In four cases of disease outbreak (three common carp breeding facilities and one koi garden pond), CEV detected belonged to genogroup I. In one case (koi garden pond), fish were confirmed as infected with CEV from genogroup II. This work complements data on CEV occurrence in European countries and contributes to a better understanding of the pathways leading to transmission of the virus throughout Europe.     

Quantitative analysis of polymeric procyanidins (Tannins) from grape (Vitis vinifera) seeds by reverse phase high-performance liquid chromatography

A reverse phase C(18) HPLC method with potential for high automated throughput has been developed for the quantitative analysis of polymeric procyanidins (tannins) in grape seed extracts. Chromatography gave rise to 13 distinct UV-absorbing peaks with good baseline separation. The UV-absorbing peak eluting last is distinct and therefore easily quantified. Biochemical analyses including ultrafiltration, protein precipitation, and Sephadex LH20 chromatography combined with electrospray mass spectrometric analyses establish that this peak predominantly contains polymeric procyanidins. The polymers, which appear to be galloylated to various degrees and seem to fragment in a characteristic manner during electrospray mass spectrometry, are well separated from catechins and procyanidin oligomers of up to 4 units. The recovery of polymeric grape seed tannins with this HPLC method was 86%, which is similar to the 89% recovery achieved with commercial quebracho tannins. The concentration of tannins in seeds from ripe Vitis vinifera cv. Shiraz grapes ranged from 1360 to 2830 mg/kg of berries.     

水牛慢性感染肝片吸虫后血液免疫功能指标及激素水平的动态变化

将８头经粪便检查和Ｄｏｔ－ＥＬＩＳＡ检测确认无肝片吸虫感染的雄性去势水牛随机分成感染组（ｎ＝５）和对照组（ｎ＝３）。感染组每天每头经口感染６０个囊蚴,连续２０ｄ。结果表明：水牛慢性感染肝片吸虫后,红细胞ＣＲ１花环率从感染后第２周即显著降低,而红细胞免疫复合物花环率则显著升高;白细胞数的总体水平在１９周前高于对照组,其中嗜酸性粒细胞显著增加,而淋巴细胞则有所下降;在淋巴细胞中可见Ｔ细胞比例显著下降,Ｂ细胞比例显著升高,并引起血清白细胞介素－２水平的降低和抗肝片吸虫的ＩｇＧ含量的显著升高。激素变化主要表现为皮质醇水平在感染初期升高,胰岛素在高于对照组的水平上波动,甲状腺激素Ｔ３、Ｔ４水平未见与对照组有明显差异。提示水牛在慢性感染肝片吸虫后,红细胞免疫功能下降,机体主要依靠嗜酸性粒细胞增加和产生特异性的ＩｇＧ抗感染,某些内分泌激素可能参与抗感染的调节机制。     

急性感染肝片吸虫水牛血中几种花生四烯酸代谢物及激素动态变化

选择12头健康、2～3岁、体重300～400kg雄性去势水牛，粪便检查和Dot—ELISA检测确认无肝片吸虫感染，随机分成感染组(n=9)和对照组(n=3)。感染组每头经口一次性感染1600个肝片吸虫囊蚴。研究了水牛急性感染肝片吸虫后血中几种花生四烯酸代谢物及激素动态变化。结果表明：水牛在急性感染肝片吸虫后整个实验期里没有明显的临床症状，具有较大的耐受力和抵抗力；水牛感染后，PGE2在16周前高于或明显高于对照组，以后两组相近；6—keto—PGF1α在整个实验期感染组与对照组无明显差异；TXB2在第1—10周低于或明显低于对照组。血浆Cort在第4—10周高于或明显高于对照组；T4在第4—22周总体水平高于或显著高于对照组；Ins和T3在整个实验期两组比较未见明显差异性变化。结果提示：水牛在急性感染肝片吸虫后，血中一些花生四烯酸代谢物变化明显，参与病理生理发生发展过程。     

High levels of genetic and genotypic diversity in field populations of the barley pathogen Ramularia collo-cygni

The ascomycete pathogen Ramularia collo-cygni causes Ramularia leaf spot (RLS) on barley. Although R. collo-cygni is considerd an emerging disease of barley, little is known about genetic diversity or population genetic structure of this pathogen. We applied a set of polymorphic AFLP (Amplified Fragment Length Polymorphism) markers to investigate population genetic structure in two Northern European populations of R. collo-cygni. The distribution of AFLP alleles revealed low levels of population subdivision and high levels of genetic diversity at both locations. Our analyses included 87 isolates and of these 84 showed a unique genotype pattern. The genetic structure of populations in Scotland and Denmark is highly similar and we find no evidence of population sub-division. An analysis of molecular variance was used to show that 86 % of the variance is attributable to within field genetic variance. In spite of the high levels of genetic and genotypic diversity in the R. collo-cygni populations, we find significant evidence of linkage disequilibrium among the AFLP alleles using a multilocus analysis. We propose that the high levels of genotypic diversity and the lack of population differentiation result from considerable levels of gene flow between populations most likely mediated by seed borne dispersal of inoculum.     

Prediction of Penicillium expansum spoilage and patulin concentration in apples used for apple juice production by electronic nose analysis

Classification models for Penicillium expansum spoilage of apples and prediction models for patulin concentration in apples usable for apple juice production were made on the basis of electronic nose (e-nose) analysis correlated to HPLC quantification of patulin. A total of 15 Golden Delicious and 4 Jonagold apples were surface sterilized and divided into three groups per variety. The Golden Delicious group consisted of five apples each. Group 1 was untreated control, group 2 was surface inoculated with P. expansum, and group 3 was inoculated in the core with P. expansum. The apples were incubated at 25 degrees C for 10 days. E-nose analysis was performed daily. At day 10 the Golden Delicious apples were individually processed for apple juice production. During apple juice production the mash and juice were analyzed by e-nose, and samples were taken for patulin analysis by HPLC. The volatile metabolite profile was obtained by collection of volatile metabolites, on tubes containing Tenax TA, overnight between the 9th and 10th days of incubation and subsequent analysis of the collected compounds by GC-MS. Prediction models using partial least-squares, with high correlation, for prediction of patulin concentration in shredded apples as well as apple juice were successfully created. It was also shown that it is possible to classify P. expansum spoilage in apples correctly on the basis of soft independent modeling of class analogy classification of e-nose analysis data. To the authors' knowledge this is the first report of a regression model between e-nose data and mycotoxin content in which actual concentrations are reported. This implies that it is possible to predict mycotoxin production and concentration by e-nose analysis.     

Study on Blood Cell Immune Response in Water Buffaloes Infected Acutely with F. hepatica

Action mechanism of blood cell immune response in water buffaloes against acute infection with F. Hepatica was studied. The results showed that after water buffaloes were infected, the total levels of WBC surpassed control group during whole infection period; Eosinophiles (%) of DC were higher than control group at the 2nd week until 19th week, and then dropped and was close to control group; Neutrophiles(%)was low or significantly lower than control group within the 5 - 16th weeks; The total levels of lymphocytes (%) was lower than control group during the whole infection period; T-lymphocytes (%) dropped significantly, but B-lymphocytes(%) had opposite changes from the first week of infection, and they were close to the control group after 11 weeks; RBC-CR1 and RBC-IC rosette rates dropped and rose during 2 - 16 and 2- 18 weeks, respectively, and then approached the same between both groups. It was suggested that the violent changes of specific and nonspecific immune responses in water buffaloes with acute F. hepatica infection are related with the mechanism against infection with F. hepatica together.     

Analysis of the acute phase responses of Serum Amyloid A, Haptoglobin and Type 1 Interferon in cattle experimentally infected with foot-and-mouth disease virus serotype O

ABSTRACT: A series of challenge experiments were performed in order to investigate the acute phase responses to foot-and-mouth disease virus (FMDV) infection in cattle and possible implications for the development of persistently infected "carriers". The host response to infection was investigated through measurements of the concentrations of the acute phase proteins (APPs) serum amyloid A (SAA) and haptoglobin (HP), as well as the bioactivity of type 1 interferon (IFN) in serum of infected animals. Results were based on measurements from a total of 36 infected animals of which 24 were kept for observational periods exceeding 28 days in order to determine the carrier-status of individual animals. The systemic host response to FMDV in infected animals was evaluated in comparison to similar measurements in sera from 6 mock-inoculated control animals.There was a significant increase in serum concentrations of both APPs and type 1 IFN in infected animals coinciding with the onset of viremia and clinical disease. The measured parameters declined to baseline levels within 21 days after inoculation, indicating that there was no systemically measurable inflammatory reaction related to the carrier state of FMD. There was a statistically significant difference in the HP response between carriers and non-carriers with a lower response in the animals that subsequently developed into FMDV carriers. It was concluded that the induction of SAA, HP and type 1 IFN in serum can be used as markers of acute infection by FMDV in cattle.     

Landscape connectivity and predator–prey population dynamics

Landscapes are increasingly fragmented, and conservation programs have started to look at network approaches for maintaining populations at a larger scale. We present an agent-based model of predator–prey dynamics where the agents (i.e. the individuals of either the predator or prey population) are able to move between different patches in a landscaped network. We then analyze population level and coexistence probability given node-centrality measures that characterize specific patches. We show that both predator and prey species benefit from living in globally well-connected patches (i.e. with high closeness centrality). However, the maximum number of prey species is reached, on average, at lower closeness centrality levels than for predator species. Hence, prey species benefit from constraints imposed on species movement in fragmented landscapes since they can reproduce with a lesser risk of predation, and their need for using anti-predatory strategies decreases.     

Large first hyperpolarizabilities in push-pull polyenes by tuning of the bond length alternation and aromaticity

Conjugated organic compounds with 3-phenyl-5-isoxazolone or N,N'-diethylthiobarbituric acid acceptors have large first molecular hyperpolarizabilities (beta) in comparison with compounds with 4-nitrophenyl acceptors. For example, julolidinyl-(CH=CH)(3)-CH=N,N'- diethylthiobarbituric acid, which has 12 atoms between the donor and acceptor, has a beta(0) of 911 x 10(-30) electrostatic units, whereas (CH(3))(2)NC(6)H(4),-(CH=CH)(4)-C(6)H(4)NO(2), with 16 atoms between its donor and acceptor, has a beta(0) of 133 x 10(-30) electrostatic units. The design strategies demonstrated here have resulted in chromophores that when incorporated into poled-polymer electrooptic modulators exhibited significant enhancements in electrooptic coefficients relative to polymers containing the commonly used dye Disperse Red-1. Poled polymer devices based on these or related chromophores may ultimately lead to high-speed electrooptic switching elements with low drive-power requirements, suitable for telecommunications applications.