Soil organic carbon–stock changes in Flemish grassland soils from 1990 to 2000

Total soil organic‐carbon (SOC) stocks for grassland soils in Flanders (N Belgium) were determined for the Kyoto Protocol reference year 1990 and 2000 in order to investigate whether these soils have been CO₂ sinks or sources during that period. The stocks were calculated by means of detailed SOC datasets, which were available at the community scale for the whole of Flanders. The total SOC stocks for Flemish grassland soils (1 m depth) were estimated at 38 Mt SOC in 1990 and 34 Mt SOC in 2000. The loss of SOC resulted from a decrease in the SOC content of grassland soils (71%) and could also partly (29%) be explained by a decline in grassland area. Significant decreases in %SOC for the 0–6 cm depth layer were found for the 1990s for the coarser‐textured soils with SOC losses ranging between –0.3% and –0.5% over the 10 y period. Specific management practices that disturb the SOC balance such as conversion to temporary grassland and a reduction of animal‐manure application are hypothesized to have contributed to the observed loss of SOC stocks. We furthermore conducted an analysis of uncertainty of the 1990 and 2000 grassland SOC–stocks calculation using Monte Carlo analysis. Probability‐distribution functions were determined for each of the inputs of the SOC‐stock calculation, enabling us to assess the uncertainty on the 1990 and 2000 SOC stocks. The frequency distributions of these simulated stocks both closely approached lognormal distributions, and their 95%‐confidence intervals ranged between 150% and 50% of the calculated mean SOC stock. The standard error on the measured decrease in SOC stocks in Flemish grassland soils during the 1990s was calculated to be 7–8 Tg SOC, which is equivalent to twice this decrease. This clearly shows that large‐scale changes in SOC stocks are uncertainty‐ridden, even when they are based on detailed datasets.     

Effect of decontamination agents on the microbial population, sensorial quality, and nutrient content of grated carrots (Daucus carota L.)

Several decontamination agents including water, sodium hypochlorite, peroxyacetic acid, neutral electrolyzed oxidizing water, and chlorine dioxide gas were tested for their effectiveness to reduce the natural microflora on grated carrots. Microbial reductions of the total aerobic count obtained after the different treatments varied between 0.11 and 3.29 log colony-forming units (cfu)/g. Whether or not a decontamination step induced significant changes in the sensory attributes of grated carrots is highly dependent on the type and concentration of disinfectant. To maintain the nutritional value, the influence of the decontamination agents on carotenoid content, alpha-tocopherol content, total phenols, and antioxidant capacity was studied. Besides the part of the nutrients that was leached away from the cutting areas by water, the nutrient losses caused by adding sanitizers were rather limited. Compared with the untreated carrots alpha-tocopherol content was, however, significantly reduced when 250 ppm of peroxyacetic acid (-80%) or 200 ppm of sodium hypochlorite (-59%) was used. Additional losses in carotenoid content were caused by contact with chlorine dioxide gas (-9%). On the condition of an optimized decontamination process toward time and concentration, the microbial quality of fresh-cut carrots could be improved without negatively influencing their sensory quality and nutrient content.     

Controlling horse heart rate as a basis for training improvement

Equine training methods, and consequently, performance times have improved little since the last decades. With advances in measuring signals on-line by means of several new technologies and analytical procedures, and processing these signals immediately with strong and compact processors, it may be possible to develop new training methods. In this research, the objective was to explore the possibilities of using modern model-based algorithms to control the heart rate of horses (bpm) on-line by means of the control input running speed (km/h). Forty-five experiments with five horses and four riders were carried out to generate measurements of physiological status during running. The dynamical characteristics of each horse were quantified using linear discrete transfer function models. The dynamic response of heart rate to step changes in running speed were accurately described. In 90% of the cases, a first-order model gave the best fit. For 69% of the models, the r² was higher than 0.90 and for 34% of the models, the r² was even higher than 0.95. In a next step, the model-based algorithm was evaluated by controlling cardiac responses of two horses (horses 2 and 4) to a pre-defined trajectory. The model parameters were kept constant. On average, the error between the defined target trajectory in heart rate and the actual controlled heart rate ranged between 0.2 and 1.4 bpm for the whole target heart rate trajectory. During the steady-state part of the trajectory the average error was maximum 1.1 bpm. In the transient from one steady-state heart rate to another level, the error could increase on average up to 5 bpm. In the future, the combination of on-line measured bioresponses with real-time analysis can be used for adjusting the work load of the horse, during training, directly to the immediate needs of horse (welfare) and trainer (performance).     

ACE inhibitory peptides derived from enzymatic hydrolysates of animal muscle protein: a review

Naturally occurring ACE (angiotensin converting enzyme) inhibitory peptides have a potential as antihypertensive components in functional foods or nutraceuticals. These peptides have been discovered in various food sources from plant and animal protein origin. In this paper an overview is presented of the ACE inhibitory peptides obtained by enzymatic hydrolysis of muscle protein of meat, fish, and invertebrates. Some of these peptides do not only show in vitro ACE inhibitory activity but also in vivo antihypertensive activity in spontaneously hypertensive rats. To focus on new sources of ACE inhibitory peptides, more specifically insects and other invertebrates, we compared the vertebrate and invertebrate musculature and analyzed phylogenetic relationships.     

Primary ovarian adenocarcinoma associated with teratomatous elements in a mare

An ovarian adenocarcinoma with teratomatous elements was removed from a 9-year-old mare. Although no other lesions were detected at ovariectomy, multifocal metastatic masses led to cachexia and euthanasia 2 months later. This case reaffirms the need to exercise caution when removing ovarian masses to prevent seeding of the abdomen. This report includes discussion of the WHO system of classification of ovarian tumors.     

Comparison of Virulence Factors and Antibiotic Resistance Profiles of Escherichia coli Strains From Humans and Dogs With Urinary Tract Infections

The purpose of this study was to compare virulence factors and antibiotic resistance profiles of Escherichia coli strains isolated from dogs and humans with urinary tract infections. Factors studied included resistance to antibiotics and the transferability of R-plasmids to a recipient E. coli; production of colicins, hemolysins, beta-lactamase, and urease; hemagglutination of erythrocytes; and fermentation of dulcitol. The canine E. coli isolates had a wider range of antibiotic resistance and a higher R-plasmid transmissibility rate. A higher percentage of the canine isolates produced colicins (40% vs. 24%), hemolysins (44% vs. 16%), beta-lactamase (52% vs. 4%), and fermented dulcitol (84% vs. 80%) as compared with the human isolates. The human isolates had a greater ability to hemagglutinate erythrocytes as compared with the canine isolates (24% vs. 8%). None of the isolates produced urease.