Investigations on the association of D-lactate blood concentrations with the outcome of therapy of acidosis, and with posture and demeanour in young calves with diarrhoea

The objective of this prospective study was to elucidate whether amounts of bicarbonate needed for correction of acidosis and normalization of clinical signs are influenced by blood D-lactate concentrations in calves with diarrhoea. In 73 calves up to 3 weeks old with acute diarrhoea and base excess values below -10 mmol/l correction of acidosis was carried out within 3.5-h by intravenous administration of an amount of sodium bicarbonate which was calculated using the formula: HCO (mmol) = body mass (kg) x base deficit (mmol/l) x 0.6 (l/kg). Clinical signs, venous base excess, and plasma D-lactate concentrations were monitored immediately following admission, following correction of acidosis at 4 h and 24 h after admission. The base excess and plasma D-lactate concentrations throughout the study were -17.8 +/- 4.0, -0.4 +/- 0.4, -3.0 +/- 5.5 mmol/l (base excess), and 10.0 +/- 4.9, 9.8 +/- 4.8, 5.4 +/- 3.4 mmol/l (D-lactate) for the three times of examination. Metabolic acidosis was not corrected in more than half of the calves (n = 43) by the calculated amount of bicarbonate, whereas the risk of failure to correct acidosis increases with D-lactate concentrations. The study shows that calves with elevated D-lactate concentrations do not need additional specific therapy, as D-lactate concentrations regularly fall following correction of acidosis and restitution of body fluid volume, for reasons that remain unclear. However, calves with distinct changes in posture and demeanour need higher doses of bicarbonate than calculated with the factor of 0.6 in the formula mentioned above probably because of D-hyperlactataemia.     

AAHA canine life stage guidelines

Guidelines are offered to guide the veterinary practitioner in designing a comprehensive, individualized wellness plan for each stage of a dog's life. Life stages are defined by both age and breed characteristics for practical purposes. Each patient visit should use an individualized approach to patient handling, preventive care, and early disease detection. Environment, behavior, nutrition, parasite control, vaccinations, dental care, zoonotic disease control, safety, and reproductive health should be addressed.     

Patterns of soil solution composition in acid forest soils: Differences between undisturbed and bulk samples

In acid forest soils pores draining under conditions of low water tension contain a solution usually differing in composition from the equilibrium solution of the bulk soil. For tree nutrition, the former was described as comparable to the bulk soil solution or less favourable. Our recent work on solution quality contradicted the universal validity of these findings. It turned out that the methods usually recommended tend to consistently reproduce the pattern of more advanced acidification of coarse pores. We applied our combination of methods to a range of soils to find out whether our previous finding of more favourable solution conditions in undisturbed soil samples as compared to the bulk soil is common or rather an exception. Undisturbed cores and bulk soil were sampled from four forested sites differing in pH and base saturation. We used an iterative procedure to adjust the equilibrium soil solution of disturbed soil and a water extraction with a soil:solution ratio of 1:2. To extract solution from undisturbed soil cores only small volumes of water were added, and we distinguished analytically between total (by ICP) and ionic (by CE) concentrations of cations. We calculated Ca/Al molar ratios and the fraction of (Al³⁺ + H⁺) on total cationic charge in solution as criteria for solution quality. Whereas with total concentrations, there always appeared to be less favourable conditions in the soil pore solution, free ionic concentrations allowed a differentiation between the soils. In view of plant nutrition, the quality of the soil solution from undisturbed samples was better, equal to, or worse than that of the bulk soil, suggesting that forest sites represent a continuum with respect to these chemical gradients. Even in soils where gradients are not observed it is not necessary to assume an equilibrium achieved by internal processes to exist between coarse pores and the bulk soil.     

Raf, a trans-acting locus, regulates the alpha-fetoprotein gene in a cell-autonomous manner

Genetic analysis provides an approach for identifying regulatory loci that govern the expression of specific genes within the context of the entire organism. Such analyses have defined two unlinked regulatory loci, termed raf and Rif, that modulate the levels of alpha-fetoprotein in liver. Of primary importance for the isolation and characterization of the raf product is to determine whether it is produced by the hepatocyte or whether it is produced by a different cell type. By means of analysis of alpha-fetoprotein expression in livers of embryo aggregation chimeras derived from mice of different raf genotypes it was possible to conclude that the product of the raf locus is expressed as a hepatocyte autonomous function that acts in trans to regulate the level of alpha-fetoprotein messenger RNA.     

Optical response of high-dielectric-constant perovskite-related oxide

Optical conductivity measurements on the perovskite-related oxide CaCu3Ti4O12 provide a hint of the physics underlying the observed giant dielectric effect in this material. A low-frequency vibration displays anomalous behavior, implying that there is a redistribution of charge within the unit cell at low temperature. At infrared frequencies (terahertz), the value for the dielectric constant is approximately 80 at room temperature, which is far smaller than the value of approximately 10(5) obtained at lower radio frequencies (kilohertz). This discrepancy implies the presence of a strong absorption at very low frequencies due to dipole relaxation. At room temperature, the characteristic relaxation times are fast (less than or approximately 500 nanoseconds) but increase dramatically at low temperature, suggesting that the large change in dielectric constant may be due to a relaxor-like dynamical slowing down of dipolar fluctuations in nanosize domains.     

AN EXPERIMENTAL METHOD TO TEST THE EFFECTS OF LOCAL EMISSION REDUCTIONS DURING SUMMERSMOG

A method is presented that makes it possible to eliminate some of the meteorological influence on the change in air pollutant concentrations (mainly NO_χ and ozone) when considering the effects of local emission reductions. The relation of measurements outside the test area to values inside the area for normal conditions (i.e. defined weather type, no emission reduction in the test area) allows prediction of the values for the test area during emission reductions, but only if this relation shows a good correlation. This prediction includes the influence of meteorological factors that are distributed more or less homogeneously within an area of about 100 km × 100 km, which includes a large part of the meteorological influence. The comparison of predicted and measured values in the test area shows the effect of emission reduction, with the uncertainty of remaining meteorological effects, of course. The method is applied to the Heilbronn ozone experiment in summer 1994. Most precise results are obtained for ozone, while conclusions for nitrogen oxides are more uncertain.     

Trends in Soil Water Composition at a Heavily Polluted Site - Effects of Decreased S-Deposition and Variations in Precipitation

Precipitation, soils and soil water in a forested catchment in western Poland have been studied during the period 1992 – 96 (see also Vogt et al., this conf.). The S-deposition in the area during the study period was 2 – 3g S m^?2 yr^?1. In spite of decreasing anthropogenic emissions the S-deposition in the area did not change much during the study period mainly because the first years were exceptionally dry. However, the S-deposition was considerably higher during the previous decade. Based on soil water sulphate concentration, pH, acid neutralising capacity and the ratio of Al³⁺/(Ca²⁺ + Mg²⁺), there is apparently an amelioration in the conditions. A study using inter alia principal component analysis, indicates that this improvement is mainly due to more precipitation in the later part of the study period. Variations in precipitation amount have a pronounced effect on the soil-water chemistry, which makes it difficult to establish trends caused by changes in anthropogenic deposition. Long time series are therefore necessary to establish recovery due to reduced S-emissions.     

Atmospheric deposition of trace elements in Norway: Temporal and spatial trends studied by moss analysis

The atmospheric deposition of sixteen trace elements, as inferred by their concentration in moss samples collected in 1985 from 500 sites in Norway, is compared with data from a similar survey in 1977. The deposition patterns of V, Zn, As, Se, Cd, Sb, and Pb are substantially influenced by long-range transport from other parts of Europe, but a general decline is evident from 1977 to 1985, most strongly for Pb. For Cr, Fe, Co, Ni, and Cu the deposition patterns are largely determined by contributions from point sources within Norway and on the Kola peninsula close to the Russian/ Norwegian border. The moss data for Br, I, and partly Se reflect airborne supply from the marine environment, whereas Al and Sc serve as indicators of contributions from soil dust. Contributions to the trace element concentrations in moss from sources other than atmospheric deposition are identified and discussed.