Rapid detection of Marek's disease virus in feather follicles by loop-mediated amplification

Marek's disease (MD) remains a serious problem in the production of poultry. The disease is caused by Marek's disease virus (MDV), and despite the ubiquitous use of vaccination to control losses, MD still affects poultry farming worldwide. The aim of this study was to develop a loop-mediated isothermal amplification (LAMP) method for the simple and inexpensive detection of MDV in feather tips of chickens. Two pairs of specific primers complementary to the meq oncogene of MDV were designed, targeting the sequence of the very virulent MDV strain, RB1B. Bst polymerase was used for the isothermal amplification of viral DNA at 65 C for 90 min in a water bath. The fluorescence signal was identified in MDV-positive samples after the addition of SYBR Green and ultraviolet (UV) illumination. The sensitivity of LAMP was 2 log 10 plaque-forming units (PFU)/ml of HPRS16 and 10(3) copies/il of plasmid containing the target gene (meq) and was equal in sensitivity to PCR amplification. Due to the use of three sets of primers, LAMP was highly specific for MDV-1 DNA. The developed LAMP technique is a rapid and simple tool for the specific detection of MDV in samples of feathers taken from live chickens. Since the use of thermocyclers is not necessary for LAMP assay, it can be conducted by small laboratories and even field veterinarians.     

Ubiquitin-binding domains in Y-family polymerases regulate translesion synthesis

Translesion synthesis (TLS) is the major pathway by which mammalian cells replicate across DNA lesions. Upon DNA damage, ubiquitination of proliferating cell nuclear antigen (PCNA) induces bypass of the lesion by directing the replication machinery into the TLS pathway. Yet, how this modification is recognized and interpreted in the cell remains unclear. Here we describe the identification of two ubiquitin (Ub)-binding domains (UBM and UBZ), which are evolutionarily conserved in all Y-family TLS polymerases (pols). These domains are required for binding of poleta and poliota to ubiquitin, their accumulation in replication factories, and their interaction with monoubiquitinated PCNA. Moreover, the UBZ domain of poleta is essential to efficiently restore a normal response to ultraviolet irradiation in xeroderma pigmentosum variant (XP-V) fibroblasts. Our results indicate that Ub-binding domains of Y-family polymerases play crucial regulatory roles in TLS.     

Ovarian fluid pH enhances motility parameters of rainbow trout (Oncorhynchus mykiss) spermatozoa

All evidence to date suggest that sperm motility is the primary determinant of fertilization success in externally fertilizing fish species. Ovarian fluid, which comprises 10–30% of the total egg volume in salmonids, enhances sperm motility with respect to swimming speed, trajectory and the duration of movement. It was recently demonstrated that there is individual variability in sperm motility enhancing potential of ovarian fluid of particular females. In the present study we examined the effect of particular ovarian fluids collected from 31 females on the sperm motility parameters of one male of rainbow trout (Oncorhynchus mykiss) using computer-assisted sperm analysis (CASA). During our experiment we also monitored the pH of ovarian fluid. We found that particular fluids differed in the ability to activate spermatozoa; sperm remained immotile in four fluids and exhibited 50–100% motility in 27 samples. The percentage of motile sperm, velocity and duration of movement positively correlated with ovarian fluid pH (r² = 0.34–0.62). These data strongly suggest that the pH of the ovarian fluid is the primary determinant of sperm motility in rainbow trout under natural conditions of fertilization.     

Exposure to non‐ionizing electromagnetic radiation of public risk prevention instruments threatens the quality of spermatozoids

The use of artificial insemination in cattle breeding has evolved to global extent, and insemination doses are often shipped via air transport which requires strict radiation‐based examinations. For the determination of effect of non‐ionizing radiation (NIR), to which are beings frequently exposed due to protection of airport or cultural event security, freshly ejaculated and cryopreserved bovine spermatozoa were used as experimental model. Following radiation with hand‐held metal detector in various exposition times (0, 10 s, 15, 30 and 60 min—groups FR, FR10, FR15, FR30 and FR60) the spermatozoa underwent motility and DNA fragmentation analyses. Study on cryoconserved semen treated with NIR was performed in time intervals 0, 10 s, 1 and 5 min (insemination doses radiated before cryoconservation—CB, CB10, CB1, CB5; samples radiated after freezing—CA, CA10, CA1 and CA5). Fresh semen and insemination doses radiated after cryoconservation showed significantly lower total and progressive motility. No effect on motility parameters was detected in semen extended with cryopreservative medium and radiated prior to freezing. Surprisingly, NIR showed a potential to stimulate spermatozoa velocity; however, the effect was modulated throughout the post‐thawing incubation. Based on the DNA fragmentation assay, sperm DNA stayed intact. Present study underlines the potential harm of NIR, which is frequently used in everyday life, with overall adverse impact on human and animal reproduction. Current study also points out on interesting short‐term spermatozoa stimulation induced by NIR.     

The identification of fracture in dried wood based on theoretical modelling and acoustic emission

Physical interpretation of the three characteristic groups of acoustic signals emitted during convective drying of wood is the main subject of this paper. The acoustic emission (AE) was to evidence the fracture intensity during drying of a birch wood sample of cylindrical shape. To explain the three characteristic groups of acoustic signals, and particularly the last one, a mechanistic model of drying was applied to analyse the drying induced stresses in the tested sample. One can conclude from this analysis that the third group of acoustic signals arises when the surface stop to shrink and the wet core (initially in compression) begins to dry. The shrinkage of the core causes compression of the boundary layer and tension of the core. Thus, the reverse of the stress signs in the cylinder cross-section takes place and this possibly involves the destruction of wood structure in the tensed core.     

Effects of helical angle of router bit on acoustic emission

The purpose of this study was to investigate the effects of changes in the helical angle of the router bit on the acoustic emission (AE) signal for various workpiece grain angles. The helical angle varied from 0° to 50° at 10° increments. The workpiece grains were oriented from 0 degrees (cutting parallel to the grain), through 90° (cutting end of the grain), to 165° at 15° increments. The AE signals and machined surface roughness were measured in an attempt to clarify the relations between them. The results were summarized as follows: (1) The AE signals were lowest in the with the grain cutting zones and slightly increased in the against the grain cutting zones; they rapidly reached the highest values at the 135°–165° grain angles. The greater the helical angle of the router bit, the smaller were the AE count rates for each grain angle investigated. There was no significant change in AE generation for helical angles of 0° and 10°. Moreover, the greater the feed rate, the greater was the AE count rate for every cutting condition investigated. (2) The surface roughness, similar to the AE count rate, had the lowest values in the with the grain cutting zones, slightly increased until the 120° grain angle, and then rapidly become extremely rough, reaching a maximum at the grain angles of 135°–150°. There was no remarkable change in the machined surface roughness while routing with the grain using the router bit of greater helical angle. However, when routing against the grain, the greater the helical angle the smoother was the machined surface. (3) There were correlations between the AE count rate and the machined surface roughness for each helical angle investigated. Therefore, acoustic emission has shown promise for monitoring and controlling the routing operation, including various grain angles and helical angles of the router bit.     

Changes of surface, fine pore and variable charge properties of a brown forest soil under various tillage practices

Effects of 6 years no-tillage (NT), ploughing, disking and the two last treatments combined with loosening on surface area, water vapor adsorption energy, variable charge and fine pore properties of a brown forest soils were studied using water vapor adsorption–desorption, back-titration and mercury intrusion measurements. The studied soil properties altered markedly under mechanical tillage treatment as compared to NT soil. The radii and the volumes of cryptopores (sizes from 1 to a few tens of nanometers) decreased and the opposite was found for ultramicropores (sizes from a few tens of nanometers to around 10 μm). However, fractal dimension of cryptopores and ultramicropores had changed very slightly, indicating that general geometrical structure of the fine pore system in the studied range (ca 1 nm–10 μm) remained unaltered despite pore size-shift. Surface areas and the amount of variable surface charge were markedly lower in mechanically tilled soil. A decrease of organic matter content was observed as well. Decrease of water vapor adsorption energy and increase of the fraction of strongly acidic surface functional groups accompanied mechanical tillage treatments.     

Assessing genetic diversity of Polish wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis>) varieties using microsatellite markers

Fifty-three wheat cultivars have been genotyped using 24 SSR (simple sequence repeat) markers in order to evaluate genetic similarities among Polish wheats, i.e. 53 spring and winter cultivars; ‘Chinese Spring’ was taken as reference. ll but one SSR marker allowed to identify DNA polymorphisms, giving in total 166 alleles (including nulls), from 3 to 13 alleles per marker with mean of 7.22. Based on marker data, genetic similarities were calculated and a dendrogram was created. ‘Spring’ cultivars were less diverse than winter ones, showing the biggest similarity to ‘Chinese Spring’. Four sister cultivars (Nutka, Tonacja, Zyta and Sukces), formed a cluster of very similar materials, of which Zyta and Sukces had the highest similarity indices. Parental lines Jubilatka and SMH 2182 were more distant from each other (genetic similarity of 0.227). It was possible to differentiate all the wheats using only four SSR markers: Xgwm186, Xgwm389, Xgwm459 and Xgwm577.     

Biochemical and genetical analysis reveal a new clade of biovar 3 <Emphasis Type="Italic">Dickeya</Emphasis> spp. strains isolated from potato in Europe

Sixty-five potato strains of the soft rot-causing plant pathogenic bacterium Dickeya spp., and two strains from hyacinth, were characterised using biochemical assays, REP-PCR genomic finger printing, 16S rDNA and dnaX sequence analysis. These methods were compared with nineteen strains representing six Dickeya species which included the type strains. A group of twenty-two potato strains isolated between 2005-2007 in the Netherlands, Poland, Finland and Israel were characterised as belonging to biovar 3. They were 100% identical in REP-PCR, dnaX and 16S rDNA sequence analysis. In a polyphasic analysis they formed a new clade different from the six Dickeya species previously described, and may therefore constitute a new species. The strains were very similar to a Dutch strain from hyacinth. On the basis of dnaX sequences and biochemical assays, all other potato strains isolated in Europe between 1979 and 1994 were identified as D. dianthicola (biovar 1 and 7), with the exception of two German strains classified as D. dieffenbachia (biovar 2) and D. dadantii (biovar 3), respectively. Potato strains from Peru were classified as D. dadantii, from Australia as D. zeae and from Taiwan as D. chrysanthemi bv. parthenii, indicating that different Dickeya species are found in association with potato.