Effect of maternally derived antibodies on the clinical signs and immune response in pigs after primary and secondary infection with an influenza H1N1 virus

The aim of this study was to determine the role of maternally derived antibodies (MDA) against an influenza H1N1 virus in the clinical protection of piglets and especially their effect on the development of the active immunity after an infection with a homologous influenza H1N1 virus. Twenty piglets with MDA and 10 piglets without MDA were housed together and inoculated twice with influenza H1N1 virus, at 7 and 15 weeks of age. Nine piglets without MDA were added to these groups at 12 weeks of age to be inoculated at 15 weeks of age only. Clinical signs, body temperature, growth performance, virus excretion, antibody responses, and influenza-specific T-cell response were monitored. It was shown that MDA protect piglets against the clinical consequences of a primary influenza infection, but that this protection is not complete. A short but significant rise in body temperature was observed and growth seemed to be inhibited due to the infection. Piglets with MDA shed virus for a longer period after an infection than piglets without MDA. Piglets with and without MDA were protected against the clinical consequences of a secondary infection. However, both after primary and secondary infection significant differences in immune responses were observed that indicated that pigs with MDA developed a weaker immunity than pigs without MDA. Furthermore, overall growth performances from weaning to slaughter show a trend in favour of pigs without maternal antibodies, compared to pigs with maternal antibodies, mainly caused by a significant better performance in the second half of the finishing period. The results of this study provide us insight in the role of MDA in clinical protection and their influence on active immunity after an influenza virus infection of pigs. Furthermore, it leads us to the discussion about the profitability of massive sow herd vaccinations in an attempt to increase MDA levels in piglets, taking into account the overall performance of these piglets and the possible effects on antigenic drift.     

Recreational Angler Perspectives of Nonnative Fishes

Although fish invasions have implications for conservation and resource management, research on public attitudes toward nonnative fishes is lacking. We surveyed boat and canal bank recreational anglers in the Everglades to assess their awareness, preferences, and perspectives of native versus nonnative fishes. Our findings showed that 79% of anglers were aware of the presence of nonnative fishes, and overall awareness was positively affected by the frequency of fishing, and years of angler experience at study sites. Frequency of fishing had a stronger effect on canal bank anglers. Boat anglers had higher awareness of nonnatives, higher familiarity with “nonnative” terminology, and expressed greater preferences for native fish. Most anglers favored native species (72% preference), and targeted native fishes, particularly Florida Largemouth Bass (66%). Overall, findings show that despite the prevalence of nonnative species, anglers favored native fishes and supported native fish conservation.     

Needs of private forest owners in the context of changing political systems: Lithuania as a case study

During the first half of the 20^th century the Baltic States were independent democratic nations where private forest ownership was practiced. After annexation to the Soviet Union, individuals in the Baltic States lost their ownership rights and collective ownership was introduced. Currently, after the break-up of the Soviet Union, the land restitution process in the forest sector is coming to an end and the ownership pattern as well as tenure rights are settled. A survey was undertaken to investigate the current state of the private forest sector in general, and the needs and expectations of private forest owners (PFO). Results of the study indicated that for private forest owners their forests first of all provide aesthetic and environmental protection values. Lithuanian PFOs lack information of forests and forest management, face extensive bureaucracy and need help in protecting their forests from fires, diseases and timber thieves.     

Airborne transport of sulphur: Impacts on chemical composition of rivers on north shore of the St. Lawrence River (Québec)

The St. Lawrence North Shore region (Québec) is subject to acid precipitation entailing sulphate deposition (17 to 22 kg SO₄ ^2? ha^?1 yr^?1) which poses a threat to sensitive aquatic ecosystems. Physicochemical surveys conducted in 1982–1983 revealed the extreme sensitivity of the region owing to weak mineralization of the waters (mean alkalinity of 55 μeq L^?1 and conductivity of 17 μS cm^?1). Calculation of the annual loads of S discharged from 21 rivers throughout the region shows atmospheric deposition as the principal source of sulphate. A decreasing west-east gradient in the concentration is interpreted in terms of the impact of long-range airborne transport, although certain local sources of S emission are not to be overlooked. Analysis of the seasonal variation in the sulphate load balance, conducted in a small drainage basin (40 km²), revealed that the sulphate anion plays a part in lowering the water pH in spring. The spring pH depression is apparently intensified by an additional input of sulphate stemming from the release of this element subsequent to accumulation in the drainage basin during summer and fall. Organic acids play a measurable role in the chemical equilibrium of surface waters in the region, particularly in the eastern sector where there is less S fallout. Low pH levels in this sector (5.5 to 6.0) point to some degree of organic acidification.     

Experimental spin ratchet

Spintronics relies on the ability to transport and use the spin properties of an electron rather than its charge. We describe a spin ratchet at the single-electron level that produces spin currents with no net bias or charge transport. Our device is based on the ground-state energetics of a single-electron transistor comprising a superconducting island connected to normal leads via tunnel barriers with different resistances that break spatial symmetry. We demonstrate spin transport and quantify the spin ratchet efficiency by using ferromagnetic leads with known spin polarization. Our results are modeled theoretically and provide a robust route to the generation and manipulation of pure spin currents.     

Assessment of quality characteristics of new Vitis vinifera L. cultivars for temperate climate vineyards

Since quality requirements for table grapes are mainly related to their physico-chemical and mechanical features, the aim of this work was to provide useful data for grape producers and consumers concerning the quality characteristics of table grapes of five new Vitis vinifera L. cultivars created in Romania and tending to spread within the temperate climate vineyards. During grape maturation, sugar content increased in a lesser extent than the reducing of total acidity, a balanced taste of grapes was given by the decrease in total acidity rather than sugar accumulation. Grapes of analysed cultivars showed lower concentrations of ascorbic acid and a higher content of organic nitrogenous compound. Berries with higher weight and volume (Transilvania cv.) incurred a higher mechanical deformation, while long berries (Gelu cv.) showed higher resistance to detachment from the pedicel, indicating higher resistance of grapes to packing, transport and storage. Antioxidant activity of mature grapes was high, but involvement of nonflavonoids in increasing the antioxidant capacity was statistically non-significant. Seeded table grapes of new Vitis vinifera L. cultivars showed superior physico-chemical and mechanical characteristics, indicating their high quality in the conditions of temperate continental climate, and promoting the studied cultivars as important grapevine germplasm resources.     

Accurate single-tree positions from a harvester: a test of two global satellite-based positioning systems

Accurate positioning of single trees registered automatically during harvesting operations opens up new possibilities for reducing the field sampling effort in forest inventories utilising remotely sensed data. In the present study, we propose to use a harvester to collect single-tree data during regular harvest operations and use these data to substitute or supplement traditional measurements on sample plots. Today’s harvesters are capable of recording single-tree information such as species and diameter at breast height, and a cut-to-length harvester was equipped with an integrated accurate positioning system based on real-time kinematic global satellite positioning, as well as a low-cost global navigation satellite system (GNSS) receiver mounted directly on the harvester head. Positions from 73 trees were evaluated and compared to coordinates obtained using a total station. At the single-tree level, the mean error for the integrated positioning system was 0.94?m. The low-cost GNSS receiver mounted on the harvester head yielded a mean error of 7.00?m. The sub-meter accuracy obtained with the integrated system suggests that data acquired with a harvester using this positioning system may have a great potential as a method for single-tree field data acquisition.     

FDC-B1: a new monoclonal antibody directed against bovine follicular dendritic cells

Follicular dendritic cells (FDCs) are a unique population of accessory cells located in the light zone of the germinal centres of lymphoid follicles. Their involvement in the generation of humoral immune responses implies a potential role for these cells in many disorders. Indeed, in prion diseases, FDCs seem to be the major sites of extraneuronal cellular prion protein expression and the principal sites of the infectious agent accumulation in lymphoid organs. The identification of FDC is useful for the analysis of their distribution in reactive lymphoid tissue as well as in pathological conditions. The production and characterisation of a new mouse monoclonal antibody directed against bovine follicular dendritic cells (FDC-B1) is reported. The antigen detected by FDC-B1 is expressed exclusively on the surface of FDCs in ruminant lymphoid organs. The antigen has an approximate molecular weight of 28 kDa.     

Comparative serum pharmacokinetics of the fluoroquinolones enrofloxacin, difloxacin, marbofloxacin, and orbifloxacin in dogs after single oral administration

The pharmacokinetics after oral application of the fluoroquinolones (FQs), enrofloxacin, difloxacin, marbofloxacin and orbifloxacin were compared in independent crossover studies in Beagle dogs. Commercially available tablet formulations were given at common dosage recommended by the manufacturers which were 2.0 mg/kg body weight (bw) for marbofloxacin, 2.5 mg/kg bw for orbifloxacin and 5.0 mg/kg bw for enrofloxacin and difloxacin. Analysis was performed by an agar diffusion assay. Pharmacokinetic parameters were calculated by noncompartmental methods. All FQs were rapidly absorbed and achieved average peak serum concentrations of 1.41, 1.11, 1.47 and 1.37 mug/mL for enrofloxacin, difloxacin, marbofloxacin and orbifloxacin, respectively. Enrofloxacin was eliminated at a terminal half-life (t(1/2)) of 4.1 h, difloxacin at 6.9 h, orbifloxacin at 7.1 h and marbofloxacin at 9.1 h. While the area under the serum concentration-time curve of the 24-h dosing interval (AUC0--24) for marbofloxacin and orbifloxacin were similar (approximately 13 microg x h/mL), enrofloxacin attained an AUC(0-24) of 8.7 and difloxacin of 9.3 microg x h/mL. Because of its favourable pharmacokinetics combined with excellent in vitro activity, enrofloxacin exhibited superior pharmacodynamic predictors of in vivo antimicrobial activity as C(max)/MIC (maximum serum concentration/minimum inhibitory concentration) and AUC(0-24)/MIC (area under the 24-h serum concentration--time curve/minimum inhibitory concentration) compared with other FQs.