Quality of testicular semen of the African catfish Clarias gariepinus (Burchell, 1822) and its relationship with fertilization and hatching success

Quality differences of testicular semen of the African catfish, Clarias gariepinus, and their influence on fertilization and hatching success were investigated. In accordance with an earlier study, two semen types of the African catfish were distinguished according to testicular maturity stage. Semen type I derived from males with white mature testes whereas type II semen derived from males with grey, partly mature testes. Semen volume, sperm cell concentration and seminal plasma pH was significantly higher in type I semen than in type II semen, while sperm motility was similar. Similar fertilization percentages were obtained with semen type I and semen type II. However, the hatching percentage was higher and the percentage of deformed hatched larvae was lower for type I semen. There were significant (P<0.01) positive correlations between sperm motility and fertilization percentage, seminal plasma pH and hatching percentage and a negative correlation between seminal plasma pH and percentage of deformed larvae. Therefore seminal plasma pH and sperm motility are useful to predict semen quality of the African catfish.     

Theodor Hellbrügge: 85 years of age – Ad multos transannos, sanos, fortunatos et beatos

We honor Theo Hellbrügge's acclaimed endeavors in the rehabilitation, or rather the prehabilitation of handicapped children. So far, he has focused on obvious handicaps, and we trust that he will include concern for everybody's silent handicaps in the future by screening for abnormal variability inside the physiological range. Therein, we introduce cis- and trans-years, components of transdisciplinary spectra that are novel for biology and also in part for physics. These components have periods, respectively, shorter and longer than the calendar year, with a counterpart in magnetoperiodism. Transyears characterize indices of geomagnetic activity and the solar wind's speed and proton density. They are detected, alone or together with circannuals, in physiology as well as in pathology, as illustrated for sudden cardiac death and myocardial infarction, a finding calling for similar studies in sudden infant death syndrome (SIDS). As transyears can beat with circannuals, and depend on local factors, their systematic mapping in space and time by transdisciplinary chronomics may serve a better understanding of their putative influence upon the circadian system. Longitudinal monitoring of blood pressure and heart rate detects chronome alterations underlying cardiovascular disease risk, such as that of myocardial infarction and sudden cardiac death. The challenge is to intervene in a timely fashion, preferably at birth, an opportunity for pediatricians in Theo Hellbrügge's footsteps.     

Zur Kenntnis der Ätherischen öle von Petersilie II. Vergleichende Untersuchung des Frucht-, Blatt- und Wurzelöles Einiger Petersiliensorten

Comparative investigations showed that the essential oils of fruits, leaves and roots of parsley contain myristicin and apiole. The composition of fruit and leaf oils of one variety corresponds to a great extent, while in root oils apiole always dominates myristicin.      

Chum salmon (Oncorhynchus keta) growth and temperature indices as indicators of the year–class strength of age‐1 walleye pollock (Gadus chalcogrammus) in the eastern Bering Sea

Ecosystem‐based fisheries management requires the development of physical and biological time series that index ocean productivity for stock assessment and recruitment forecasts for commercially important species. As recruitment in marine fish is related to ocean condition, we developed proxies for ocean conditions based on sea surface temperature (SST) and biometric measurements of chum salmon (Oncorhynchus keta) captured in the walleye pollock (Gadus chalcogrammus) fishery in the eastern Bering Sea in three periods (July 16–30, September 1–15 and September 16–30). The main purpose of this paper was to evaluate Pacific salmon (Oncorhynchus spp.) growth as a possible indicator of ocean conditions that, in turn, may affect age‐1 walleye pollock recruitment. Marine growth rates of Pacific salmon are the result of a complex interplay of physical, biological and population‐based factors that fish experience as they range through oceanic habitats. These growth rates can, therefore, be viewed as indicators of recent ocean productivity. Thus, our hypothesis was that estimated intra‐annual growth in body weight of immature and maturing age‐4 male and female chum salmon may be used as a biological indicator of variations in rearing conditions also experienced by age‐0 walleye pollock; consequently, they may be used to predict the recruitment to age‐1 in walleye pollock. Summer SSTs and chum salmon growth at the end of July and September explained the largest amount of variability in walleye pollock recruitment indicating that physical and biological indices of ocean productivity can index fish recruitment.     

Epidemiologically non-feasible singleton reactors at the final stage of BoHV1 eradication: Serological evidence of BoHV2 cross-reactivity

A voluntary marker-independent Bovine Herpesvirus 1 (BoHV1) eradication program started in 1986; in 1998 it changed to a compulsory one. Certification of free regions in European member states is based on Article 10 of directive 64/432/EEC. According to this rule Bavaria is listed as free of BoHV1 since October 2011. Surveillance of BoHV1-free dairy cattle farms is currently performed with quarterly bulk-milk testing. Non-negative bulk-milk results must be confirmed by blood tests in cattle older than nine months. An increased regional rate of non-negative bulk-milk samples and the subsequent detection of epidemiologically non-feasible singleton BoHV1-reactors by analysis of blood were observed at the final stage of eradication in southwest Bavaria. Nineteen case farms (734 animals) defined by singleton reactors born at least two years after certification of the farms as BoHV1-free, 23 negative control (NC) farms (NC I: 321 animals) from the same region, 11 NC-farms (NC II: 423 animals) from an already-certified Article 10 region in northeast Bavaria and two BoHV1-infected farms (264 animals) were analysed using BoHV1-, BoHV2- and Feline Herpesvirus 1 (FeHV1)-neutralisation tests (NTs), and three commercially available ELISAs supplied by Idexx Laboratories, B.V., The Netherlands: the CHEKIT? Trachitest 2nd Gen. test for milk or serum (Trachitest), Herdchek? gB- (gB-ELISA) and Herdchek? gE-ELISA (gE-ELISA). Significantly increased levels of BoHV2 antibodies were observed on case farms compared to NC I or II farms. Additionally, reactivity by gB-ELISA and the Trachitest was significantly increased for animals with BoHV2 neutralising antibodies. Singleton BoHV1-reactors tested negative by gE-ELISA even if an elevated cut-off of 0.95±0.05 was applied. At this cut-off, the gE-ELISA was as sensitive and specific as the gB-ELISA. Comparative titration of milk samples from seropositive animals from a BoHV1-infected dairy cattle farm and from singleton BoHV1-reactors performed in CHEKIT? Trachitest 2nd Gen. Milk revealed that the slopes of both groups were distinct; therefore, optimised cut-offs for bulk-milk testing to exclude singleton BoHV1-reactors are proposed.     

Toxoplasma gondii sexual cross in a single naturally infected feline host: Generation of highly mouse-virulent and avirulent clones, genotypically different from clonal types I, II and III

ABSTRACT: Tachyzoite clones obtained from a single Toxoplasma gondii oocyst field sample were genotyped and characterized regarding mouse virulence. PCR-RFLP genotyping of tachyzoites initially isolated from interferon-γ-knockout (GKO) mice, BALB/c mice and VERO cell culture using the nine independent, unlinked genetic markers nSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico revealed mixed T. gondii infections showing combinations of type II and type III alleles at different loci. Forty-five individual clones were obtained from all mixed T. gondii tachyzoite cell cultures by limiting dilution. Sixteen T. gondii clones showed type III alleles at all loci and 29 clones displayed a combination of type II and type III alleles at different loci. Five clone groups were identified in total, four of which include T. gondii clones that showed a non-canonical allele pattern and have never been described in natural infections before. All tested clones, except two, were highly virulent in BALB/c mice. The isolation of different non-canonical T. gondii clones originating from an oocyst sample of a single naturally infected cat demonstrate that sexual recombination as well as re-assortment of chromosomes via a sexual cross of T. gondii occur under natural conditions and result in the emergence of clones with increased virulence in mice.     

New insights into the genetics of EBLV-1 from Germany

Previous epidemiological studies on EBLVs indicated a distinct geographical distribution of EBLV-1 in Germany. In this study, 48 isolates were selected to further investigate the spatial and temporal distribution of EBLV-1 variants in Germany. The nucleoprotein-gene (N), the nucleoprotein-phosphoprotein spanning untranslated region (NP-UTR) and the UTR between G- and L-gene of each isolate were sequenced using direct cycle sequencing. Results of the subsequent phylogenetic analysis of the N-gene confirmed previous studies on EBLVs, showing a high sequence identity among German EBLV-1a isolates, and a correlation between genetic and temporal and spatial distance, respectively, was shown. Our results indicate that the GL-UTR is not suitable for phylogenetic analyses. Interestingly, 6 nt insertions in two isolates as well as a single nucleotide insertion in a different isolate were detected in the N-P UTR. Within the UTR between G- and L-gene one isolate showed a 35 nt deletion. The effect of those changes on viral properties remains elusive as such mutations have not been described for lyssaviruses before.     

Geochemical monitoring of organic and inorganic pollutants in the sediment of the Eastern Posavina (Serbia)

Purpose

The aim of this study was to obtain a complete picture of the geochemical character of the sediment in the eastern Posavina region, Serbia, an area which has thus far not been systematically investigated. Geological mapping and impact assessment were thus carried out for this area.

Materials and methods

Sediments were sampled (from 0 to 0.5 m depth) in four locations in eastern Posavina between 2002 and 2014. Eight heavy metals (Ni, Zn, Cd, Cr, Cu, Pb, As and Hg) and a wide variety of organic parameters (16 EPA polycyclic aromatic hydrocarbons (PAHs), mineral oils, selected pesticides and polychlorinated biphenyls (PCBs)) were monitored. Metals were analysed by flame and graphite atomic absorption spectrometry, and gas chromatography with mass detection was used for the PAH analyses. The origins of the monitored substances were classified using geoaccumulation index (I _geo), ecological risk index (RI) and principal component analysis (PCA/FA).

Results and discussion

The sediments all contained higher heavy metals concentrations than the upper continental crust (UCC), suggesting dynamic natural and anthropogenic processes in this unique region. Significant variations (RSD values from 13 to 190) were observed for Cd (0.001–80.00 mg kg^?1), Hg (0.01–5.40 mg kg^?1), mineral oil (2.00–1851 mg kg^?1) and the sum of 16 EPA PAHs (0.003–5.57 mg kg^?1). The I _geo index classified the pollution risk due to Cr as strong, Cd, Zn and Hg as moderate to strong and Ni as moderate. Based on PCA/FA analysis, the parameters were grouped somewhat differently, with anthropogenic activity found to be responsible for much of the Hg, Cd and Cr pollution present in the sediments.

Conclusions

The analysis revealed eight heavy metals (Ni, Zn, Cd, Cr, Cu, Pb, As and Hg), the sum of 16 EPA PAHs and mineral oil as parameters of great interest for this unique region. These parameters must be the focus of future monitoring programs, in support of appropriate remediation techniques and/or dredging activities, which are required in order to comply with the new Serbian regulations and the relevant EU recommendations.

     

Concentrations of Some Metabolites Produced by Fungi of the Genus Fusarium and Selected Elements in Spring Spelt Grain

The aim of this study was to determine the content of selected elements and metabolites produced by fungi of the genus Fusarium in spelt (Triticum spelta L.) grain and husks and common wheat (T. aestivum L.) grain. Concentrations of trichothecenes, a volatile metabolite trichodiene (TRICH), as well as ergosterol (ERG) and adenosine 5′‐triphosphate (ATP) (a total microbial biomass indicator), were assessed. Toxin concentrations in spelt grain and husks harvested in 2003 and 2004 were comparable. Average deoxynivalenol concentrations reached 450 and 523 μg/kg in grain and 2,162 and 855 μg/kg in husks, respectively. Spelt grain, in comparison with common wheat grain, contained significantly higher concentrations of P, S, Mg, Zn, and Cu and a lower concentration of Al, whereas the concentrations of Ca, Fe, and Pb were significantly higher in the husks than in the grain of this cereal. A comparison of concentrations of Fusarium spp. metabolites in the grain of spelt and common wheat showed that the total concentration of mycotoxins and TRICH was slightly lower in T. spelta, whereas common wheat grain contained lower concentrations of ERG and ATP. The obtained results indicate that spelt husks contain considerable concentrations of trichothecenes.