UDC 547

Abstract Known laboratory-scale and industrial methods are reviewed therein concerning the production of one of the most important vulcanization accelerators such as kaptax (2-mercaptobenzothiazol) those are based on modifying the substituents in the thiazol ring and synthesizing from acyclic precursors. The latter include also the main industrial method of obtaining kaptax based on the reaction between aniline, sulphur and carbon disulphide dangerous from the environmental point of view. Potentialities are demonstrated concerning the development of methods for producing kaptax without using carbon disulphide, which would significantly improve the environment safety of the process

Immunobiological Characteristics of the Attenuated African Swine Fever Virus Strain Katanga-350

The African swine fever virus (ASFV) is the cause of a recent pandemic that is threatening the global pig industry. The virus infects domestic and wild pigs and manifests with a variety of clinical symptoms, depending on the strain. No commercial vaccine is currently available to protect animals from this virus, but some attenuated and recombinant live vaccine candidates might be effective against the disease. This article describes the immunobiological characteristics of one such candidate—the laboratory-attenuated ASFV strain, Katanga-350—which belongs to genotype I. In this study, we assessed clinical signs and post-mortem changes, the levels of viremia and the presence of viral DNA caused by injection of ASF virus strains Katanga-350, Lisbon-57, and Stavropol 08/01. Intramuscular injection of this strain protected 80% of pigs from a virulent strain of the same genotype and seroimmunotype (Lisbon-57). At least 50% of the surviving pigs received protection from subsequent intramuscular infection with a heterologous (genotype II, seroimmunotype VIII) virulent strain (Stavropol 08/01). Virus-specific antibodies were detectable in serum and saliva samples between 8–78 days after the first inoculation of the Katanga-350 strain (the observational period). The results suggested that this strain could serve as a basis for the development of a recombinant vaccine against ASF viruses belonging to seroimmunotype I

An Assessment of Diagnostic Assays and Sample Types in the Detection of an Attenuated Genotype 5 African Swine Fever Virus in European Pigs over a 3-Month Period

African swine fever virus causes hemorrhagic disease in swine. Attenuated strains are reported in Africa, Europe, and Asia. Few studies on the diagnostic detection of attenuated ASF viruses are available. Two groups of pigs were inoculated with an attenuated ASFV. Group 2 was also vaccinated with an attenuated porcine reproductive and respiratory syndrome virus vaccine. Commercially available ELISA, as well as extraction and qPCR assays, were used to detect antibodies in serum and oral fluids (OF) and nucleic acid in buccal swabs, tonsillar scrapings, OF, and blood samples collected over 93 days, respectively. After 12 dpi, serum (88.9% to 90.9%) in Group 1 was significantly better for antibody detection than OF (0.7% to 68.4%). Group 1′s overall qPCR detection was highest in blood (48.7%) and OF (44.2%), with the highest detection in blood (85.2%) from 8 to 21 days post inoculation (dpi) and in OF (83.3%) from 1 to 7 dpi. Group 2′s results were not significantly different from Group 1, but detection rates were lower overall. Early detection of attenuated ASFV variants requires active surveillance in apparently healthy animals and is only reliable at the herd level. Likewise, antibody testing will be needed to prove freedom from disease

Virulence of Hymenoscyphus albidus and H. fraxineus on Fraxinus excelsior and F. pennsylvanica

European ash (Fraxinus excelsior) is currently battling an onslaught of ash dieback, a disease emerging in the greater part of its native area, brought about by the introduction of the ascomycete Hymenoscyphus fraxineus (= Hymenoscyphus pseudoalbidus). The closely-related fungus Hymenoscyphus albidus, which is indigenous to Europe, is non-pathogenic when in contact with F. excelsior, but could pose a potential risk to exotic Fraxinus species. The North American green ash (Fraxinus pennsylvanica) is planted widely throughout Europe and regenerates naturally within this environment but little is known about the susceptibility of this species to ash dieback. We performed wound inoculations with both fungi (nine strains of H. fraxineus and three strains of H. albidus) on rachises and stems of F. excelsior and F. pennsylvanica under field conditions in Southern Poland. Necrosis formation was evaluated after two months on the rachises and after 12 months on the stems. After inoculation of H. albidus, only small lesions (of up to 1.3 cm in length) developed on the F. excelsior and F. pennsylvanica rachises, but with no significant distinction from the controls. Hymenoscyphus albidus did not cause necrotic lesions on the stems of either Fraxinus species. In contrast, H. fraxineus induced necroses on all inoculated rachises of both ash species with mean lengths of 8.4 cm (F. excelsior) and 1.9 cm (F. pennsylvanica). Necroses also developed on all of the inoculated F. excelsior stems (mean length 18.0 cm), whereas on F. pennsylvanica such lesions only occurred on about 5% of the stems (mean length 1.9 cm). The differences between strains were negligible. No necroses were observed on the control plants. Reisolations of H. albidus were only successful in around 8–11% of the cases, while H. fraxineus was reisolated from 50–70% of the inoculated organs showing necrotic lesions. None of the Hymenoscyphus species were isolated from the control plants. Our data confirm H. fraxineus’ high virulence with regards to F. excelsior and demonstrate a low virulence in relation to F. pennsylvanica under field conditions in Poland. Hymenoscyphus albidus did not express any perceivable pathogenicity on both host species

Late Ordovician trilobites from the Taimyr Peninsula, Arctic Russia

Ordovician trilobites from the important sequences of the Taimyr Peninsula, Arctic Russia have been poorly studied since the work by Balashova (1959, 1960). Newly collected and well-preserved specimens from Late Ordovician sections, along with the original collections of Balashova, form the basis of a reappraisal of 56 Upper Ordovician (Sandbian-Katian) trilobites. New species include Bronteopsis tenuirhachis, Dionide trigintasegmentata, Failleana superba, Pararemopleurides ornatissimus, Raymondella plastron, Robergia subtilis and R. nikolaiseni. Probable new species include: Stenopareia sp. aff. S. glaber, and Stygina sp. aff. S. latifrons. A new subgenus Bilobaspis of the monorakine genus Evenkaspis, and a new species, Evenkaspis (Bilobaspis) mirabilis, are proposed. Thoracic segments and pygidium are correctly associated for the first time with cephala of the hitherto poorly understood Taimyraspis. The genera Effnaspis and Yumenaspis are likely junior synonyms of Taimyraspis. A placement within the Ityophoridae is suggested for Taimyraspis, together with the closely related genera Ityophorus and Frognaspis. Comparison of Goldillaenoides taimyricus with Failleana suggests that these are also closely related. A provisional placement of the former in the Styginidae is adopted. Bronteopsis nannus Balashova could be a juvenile B. tenuirhachis, and is regarded as a nomen dubium. The genus Ceratevenkaspis dominates among the monorakines on Taimyr, while Monorakos itself has not been collected. Robergia nikolaiseni has a narrow cranidial border, which is also present in the type species of Robergia. Two biofacies are identified in the current collections. The first, the raphiophorid association, is widespread around low latitude Ordovician palaeocontinents, identifying marginal shelf sites; the association is not critical in defining palaeocontinents themselves. Inner shelf faunas of the monorakine-cheirurid-illaenid association have taxa that comprise a distinctive group with a strong link between Taimyr and the Ordovician Siberian craton. The trilobites described herein support reconstructions showing Taimyr peripheral to the Siberian craton during the Ordovician.