Paratuberculosis in farmed and free-living wild ruminants in the Czech Republic (1999-2001).

Due to the occurrence of the infection of Mycobacterium avium subspecies paratuberculosis among domestic ruminants and the rapid development of farmed deer industry and the market of cloven-hoofed game we have carried surveys of paratuberculosis, beginning in 1997, in the most common four species of wild ruminants in the Czech Republic [Pavlik et al., Vet. Microbiol. 77 (2000) 231-251]. From 1999 the prevalence of paratuberculosis has been slightly reduced in all three types of husbandry of wild ruminants. Nevertheless paratuberculosis has been diagnosed in wild ruminants in three districts, in four game parks and in five farms. M. a. paratuberculosis was isolated from 128 (5.3%) out of 2,403 wild ruminants of four animal species: 106 red deer, 2 roe deer, 4 fallow deer and 16 mouflons. In red deer farms, the highest number of clinical paratuberculosis cases was in yearling deer. RFLP type B-C1 of M. a. paratuberculosis predominated during the second period (1999-2001) in all types of husbandry with no relationship to wild ruminant species. New "cattle" RFLP types B-C5 and B-C16 of M. a. paratuberculosis were described in infected farmed red deer and one "intermediate" RFLP type R-I4 in fallow deer from one game park. The survival of M. a. paratuberculosis was found to be 4 months during winter in the pasture after destocking of all cattle infected with paratuberculosis. We found that non-vertebrates, wild ruminants or non-ruminant wildlife can be vectors and potentially become a risk factor in the spread of M. a. paratuberculosis infection.

INAA and PIXE of atmospheric and combustion aerosols.

Using instrumental neutron activation analyses and photon-induced x-ray emission techniques for analysis of size-fractionated atmospheric and combustion aerosols and other emission samples arising from fluidized-bed combustion of North Bohemian lignites up to 42 elements were determined in all samples types. This allowed the evaluation of element enrichment, time trends, and inter-element correlations and the performance of factor analysis of various fractions of atmospheric aerosols. The data obtained on mass and element size distributions of aerosols and emission samples obtained upon lignite combustion in an experimental scale atmospheric fluidized-bed combustor without and with added hydrated lime and limestone were used to elucidate the mechanism of abatement of toxic trace and matrix elements from flue gas.

Matrix effects in PIXE analysis of aerosols and ashes.

A comparison of instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE) results for size-fractionated atmospheric aerosols ("coarse" and "fine" fractions with an equivalent aerodynamic diameter of 2-10 microns and < 2 microns, respectively, or the PM10 fraction) showed that PIXE yielded significantly lower results for the PM10 and coarse fractions, especially for elements with a low Z resulting from a particle size effect. Somewhat lower PIXE results were also obtained for the fine fraction of atmospheric aerosols. A correction is also needed for irregularly shaped deposits of combustion aerosols collected by a cascade impactor in 11 size fractions ranging from 0.016 to 14.3 microns, as well as for thick samples of fly and bottom ashes. An equivalent layer thickness (ELT) model is proposed to correct the matrix effects in PIXE. The approaches for the calculation of ELT using a comparison of PIXE and INAA results or by comparing PIXE results obtained using two different incident proton beam energies (1.31 and 2.35 MeV) are described. The correction for the ash pellets and irregular deposits are also discussed.

Effect of Tylenchorhynchus robustoides on Growth of Buffalo Grass and Western Wheatgrass.

Tylenchorhynchus robustoides reduced (P = 0.05) growth of Agropyron smithii (western wheatgrass) at soil temperatures of 20, 25, 30, and 35 C. Growth reduction increased with increasing soil temperatures. Highest populations of T. robustoides were recovered at 25 and 30 C. Clipping weights of Buchloe dactyloides (buffalo grass) were reduced at 25 and 30 C; however, root/crown weights were reduced at 15, 20, 30, and 35 C in nematode infested vs. noninfested soil. Reproduction of T. robustoides was greater at 25, 30, and 35 C than at 20 C on B. dactyloides. In a greenhouse study, T. robustoides reduced clipping and root/crown weights of both grasses 24-64%.

Effect of Tylenchorhynchus nudus on Growth of Kentucky Bluegrass.

The effect of Tylenchorhynchus nudus on growth of Kentucky bluegrass was investigated under controlled environmental conditions in both a phytotron and a greenhouse. The nematode significantly reduced weights of clippings, crowns and roots. Pathogenicity was greater in sandy loam soil than in loam and was enhanced by submitting plants to nutrient and/or moisture stresses; soil nutrient level was most critical. The results suggest that T. nudus contributes significantly to summer decline of bluegrass lawns in South Dakota.

Reproduction of Pratylenchus hexincisus and P. scribneri in Corn Inbreds.

Population development of lesion nematodes was measured in 17 inbred lines of South Dakota and A619Ht dent corn. In two greenhouse groundbed tests, lines SD 101, SD 102, and SD 103 supported fewer than 1,000 Pratylenchus hexincisus per gram of dry root after 12 weeks. In an irrigated field test, inbred SD101 supported fewer than 1,000 P. scribneri per gram of dry root on each of two sampling dates, whereas line A619Ht supplied high populations of P. scribnerni on both dates. Inbreds SD45, 84742, and 84763 supported high populations of both P. hexincisus and P. scribneri.

Relationship of Yields and Pratylenchus spp. Population Densities in Dryland and Irrigated Corn.

Analyses of covariance were used to relate corn yields to population densities of Pratylenchus hexincisus in South Dakota dryland corn or P. scribneri in irrigated corn. The relationship for P. hexincisus was Y = 5,825 - 0.14X - 0.03X' where Y = yield (kg/ha), X = number of P. hexincisus per gram of dry root at midseason and X' = number at harvest. The relationship for P. scribneri was best described by Y = 7,400 - 0.06X' for nematode populations measured at harvest. Yield loss estimates indicated P. hexincisus was more damaging to dryland corn than was P. scribneri to irrigated corn.

Mass and chemically speciated size distribution of Prague aerosol using an aerosol dryer--the influence of air mass origin.

Ambient aerosol particles dried using a diffusional aerosol dryer were sampled using a 7-stage modified Berner low pressure impactor with a back-up filter during the heating and non-heating season campaigns in 2008. The samples were analyzed for water-soluble ions and water-soluble organic carbon. Because of the drying, the aerosol size distribution was not influenced by the daily variability of ambient relative humidity. The results summarize the observations from campaigns in both the heating (11 sampling days) and non-heating (10 sampling days) seasons. The aerosols sampled on individual days were classified based on the connected air mass back trajectories into three classes: sea-influenced aerosol (SIA), continental aerosol (CA) and mixed aerosol (MA) for samples of intermediate origin. The differences between CA and SIA were substantial both when looking at the normalized mass size distributions of the particulate matter (PM) and of the individual species and when taking into account the absolute concentrations in the fine and coarse size fractions. The main differences were found in the normalized mass size distributions of the PM and of the sea-salt related ions.

Comparison of particulate number concentrations in three Central European capital cities.

Number size distributions of atmospheric aerosol particles in the mobility diameter range from 10 to 1000 nm were determined in Budapest, Prague and Vienna for a one-year-long period. Particle number concentrations in various size fractions, their diurnal and seasonal variations, mean size distributions and some properties of new particle formation events were derived and compared. Yearly median particle number concentrations for Budapest, Prague and Vienna were 10.6×10(3), 7.3×10(3) and 8.0×10(3) cm(-3). Differences were linked to the different pollution levels of the cities, and to diverse measurement environments and local conditions. Mean contributions of ultrafine particles (particles with a mobility diameter <100 nm) to the total number concentration were 80%, 84% and 74% for Budapest, Prague and Vienna, thus these particles represent an overwhelming share of all particles in each city. Seasonal variation of particle number concentrations was not obvious. Diurnal variations of particles with a diameter between 100 and 1000 nm (N(100-1000)) exhibited similar shape for the cities, which was related to the time-activity pattern of inhabitants and regional influences. The structure of the diurnal variation for ultrafine particles was also similar. It contained a huge morning peak in each city which was explained by emissions from vehicular traffic. The second peak was shifted from afternoon rush hours to late evenings as a result of the daily cycling in meteorological parameters. The character of the measurement site also influenced the diurnal variation. Diurnal variation of the mean ratio of ultrafine particles to N(100-1000) clearly revealed the presence and importance of new particle formation and subsequent growth in urban environments. Nucleation frequencies in Budapest and Prague were 27% and 23%, respectively on a yearly time scale. They showed a minimum in winter for both places, while the largest nucleation activity was observed in spring for Budapest, and in summer for Prague.

The homogeneous nucleation of 1-pentanol in a laminar flow diffusion chamber: the effect of pressure and kind of carrier gas.

The influence of total pressure and kind of carrier gas on homogeneous nucleation rates of 1-pentanol was investigated using experimental method of laminar flow diffusion chamber in this study. Two different carrier gases (helium and argon) were used in the total pressure range from 50 to 400 kPa. Nucleation temperatures ranged from 265 to 290 K for 1-pentanol-helium and from 265 to 285 K for 1-pentanol-argon. Nucleation rates varied between 10(1) and 10(6) cm(-3) s(-1) for 1-pentanol-helium and between 10(2) and 10(5) cm(-3) s(-1) for 1-pentanol-argon. Both positive and slight negative pressure effects were observed depending on temperature and carrier gas. The trend of pressure effect was found similar for both carrier gases. Error analysis on thermodynamic properties was conducted, and the lowering of surface tension due to adsorption of argon on nucleated droplets was estimated. A quantitative overview of pressure effect is provided.

Physico-chemical characterization of indoor/outdoor particulate matter in two residential houses in Oslo, Norway: measurements overview and physical properties--URBAN-AEROSOL Project.

Indoor/outdoor measurements have been performed in the Oslo metropolitan area during summer and winter periods (2002-2003) at two different residential houses. The objective of the measurement study was to characterize, physically and chemically, the particulate matter (PM) and gaseous pollutants associated with actual human exposure in the selected places, and their indoor/outdoor relationship. In this paper, we focus on the PM measurements and examine the relationship between the indoor and outdoor PM concentrations taking into account the ventilation rate, indoor sources and meteorological conditions. The indoor/outdoor measurements indicate the important contribution of the outdoor air to the indoor air quality and the influence of specific indoor sources such as smoking and cooking to the concentration of PM inside houses. However, no specific correlation was found between the indoor/outdoor concentration ratio and the meteorological parameters. This study provides information on the physical characteristics and the relationship of indoor to outdoor concentration of particulate matter in residential houses. Moreover, the parameters that influence this relationship are discussed. The results presented here are specific to the sampled houses and conditions used and provide data on the actual human exposure characteristics which occur in the spatial and temporal scales of the present study.

Antimicrobial prophylaxis in head and neck surgery.

In this random study, 60 patients were given either cefotaxime, or ceftriaxone as a prophylactic measure in cervicofacial surgery. Each antibiotic was administered during a 48-hour period starting 1 h before the operation. Twenty-three patients underwent major cervicofacial surgery including opening of the pharynx or the buccal cavity by the cervical route. Only a single postoperative infection was observed as a result of a salivary fistula on the 2nd postoperative day. The two antibiotics have turned out to be very efficient as short-term prophylactic treatment in cervicofacial surgery. In other respects, the much longer half-life of ceftriaxone means that a single daily dose can be given. Finally, the cost of the prophylactic treatment is smaller using ceftriaxone than cefotaxime.