Effects of yeasts and bacteria on the levels of folates in rye sourdoughs

Fermentation of rye dough is often accompanied with an increase in folate content. In this study, three sourdough yeasts, Candida milleri CBS 8195, Saccharomyces cerevisiae TS 146, and Torulaspora delbrueckii TS 207; a control, baker's yeast S. cerevisiae ALKO 743; and four Lactobacillus spp., L. acidophilus TSB 262, L. brevis TSB 307, L. plantarum TSB 304, and L. sanfranciscensis TSB 299 originally isolated from rye sourdough were examined for their abilities to produce or consume folates. The microorganisms were grown in yeast extract-peptone-d-glucose medium as well as in small-scale fermentations that modelled the sourdough fermentation step used in rye baking. Total folate contents were determined using Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism. The microorganisms studied did not excrete folates into the media in significant amounts. Yeasts increased the folate contents of sterilised rye flour-water mixtures from 6.5 microg/100 g to between 15 and 23 microg/100 g after 19-h fermentation, whereas lactic acid bacteria decreased it to between 2.9 and 4.2 microg/100 g. Strains of Lactobacillus bulgaricus, L. casei, L. curvatus, L. fermentum, L. helveticus, Pediococcus spp., and Streptococcus thermophilus that were also tested gave folate contents after fermentation that varied between 2 and 10.4 microg/100 g. Although the four Lactobacillus spp. from sourdough consumed folates their effect on folate contents in co-cultivations was minimal. It was concluded that the increase of folate content during fermentation was mainly due to folate synthesis by yeasts. Fermentation of non-sterilised flour-water mixtures as such resulted in three-fold increases in the folate contents. Two folate producing bacteria were isolated from the non-sterilised flour and identified as Enterobacter cowanii and Pantoea agglomerans.     

The prevalence of Clostridium botulinum in European river lamprey (Lampetra fluviatilis) in Finland

The prevalence of Clostridium botulinum types A, B, E and F in river lampreys caught in Finnish rivers was determined for the first time using a quantitative PCR-MPN (most probable number) analysis. One of 67 raw whole lampreys (1.5%) was positive for the botulinum neurotoxin type E gene, with the estimated C. botulinum count being 100spores/kg. Two type E strains were isolated from the positive sample and confirmed as different genotypes by pulsed-field gel electrophoresis. Although the current procedure of bringing the charcoal-broiled lampreys to market has been without any further packaging or extended storage, interest towards increasing the shelf life of the product by vacuum-packaging is increasing. Our results demonstrate that C. botulinum type E may constitute a safety hazard in processed lampreys from the Baltic Sea area if packaging and extended shelf lives are to be used. To control the potential risk, a storage temperature of 3 degrees C or below should be recommended for these products.     

Prevalence and genetic characterization of Listeria monocytogenes in retail broiler meat in Estonia

The prevalence and genetic diversity of Listeria monocytogenes in raw broiler legs at the retail level in Estonia were studied. A total of 240 raw broiler legs (120 from Estonia and 120 of foreign origin, which had been imported to Estonia from Denmark, Finland, Hungary, Sweden, and the United States) from 12 retail stores in the two largest cities in Estonia (Tallinn and Tartu) were investigated from January to December 2002. Of these, 70% were positive for L. monocytogenes. The prevalence of L. monocytogenes in broiler legs of Estonian origin (88%) was significantly higher than in broiler legs of foreign origin (53%) (P < 0.001). Altogether, 169 (106 Estonian and 63 imported) L. monocytogenes isolates were characterized by pulsed-field gel electrophoresis (PFGE) typing after treatment with the restriction enzyme AscI. The isolates showed a wide genetic diversity, with 35 different PFGE types obtained. Of these, 11 PFGE types came only from isolates of broiler legs of Estonian origin, 4 of Danish origin, 2 of Finnish origin, and 4 of Hungarian origin. Fourteen PFGE types came from isolates of broiler legs that originated from various countries. The strains that shared the same PFGE types from isolates of Estonian origin were recovered from broiler legs that came from different stores over the course of several months. Seventy-one L. monocytogenes isolates, including all PFGE types, were serotyped, and three serotypes (1/2a, 1/2b, and 4b) were obtained. Serotype 1/2a accounted for 96% of the isolates.     

Indirect energy input of agricultural machinery in bioenergy production

Sustainability of bioenergy products should be evaluated by means of an energy analysis that takes into account all relevant direct and indirect energy inputs. Direct energy input is viewed as the major energy consuming factor, and is quite easy to measure. Indirect energy input, however, has received relatively scant attention, so it is likely to be insufficiently analysed and possibly underestimated. This paper reviews the data available and suggests the type of research that would be needed to get a better understanding of the indirect energy input. The analysis addresses questions about the use of energy to produce and maintain agricultural machinery, the allocation of energy to different bioenergy products, and the real use and lifetime of machinery.     

Heat stress and bulkiness of chemical protective clothing impair performance of medical personnel in basic lifesaving tasks

The study examined the impact of chemical protective (CP) clothing on the performance of lifesaving tasks in thermoneutral and cold conditions. Eleven males performed pre-exercise followed by lifesaving tasks wearing either field combat uniform at 21 degrees C (U) or CP clothing at 21 degrees C (CPN) and -5 degrees C (CPC). The tasks were ventilating a doll (VA) and connecting an intravenous line (IV). Mean skin temperature was significantly higher for CPN compared to U and CPC during pre-exercise, VA and IV. Changes in blood pressure were significantly greater with CP clothing than without during VA and IV. The number of breaths per min (in VA) and time needed for IV increased by 19% (p < 0.05) and 18%, respectively, for CPN compared to U. Due to the cold, the additional increment was 5% and 17%, respectively, for CPC. Wearing of CP clothing in thermoneutral or in cold conditions may not prevent but, especially in the cold, significantly impede the performance of basic medical tasks. The findings of this study showed that performing medical tasks while wearing nuclear, biological and chemical protective clothing is impaired due to significant changes in physiological strain. This suggests that realistic training in local conditions as well as in cold conditions is needed to realise the restrictions due to protective clothing.     

Complex-valued ICA based on a pair of generalized covariance matrices

It is shown that any pair of scatter and spatial scatter matrices yields an estimator of the separating matrix for complex-valued independent component analysis (ICA). Scatter (resp. spatial scatter) matrix is a generalized covariance matrix in the sense that it is a positive definite hermitian matrix functional that satisfies the same affine (resp. unitary) equivariance property as does the covariance matrix and possesses an additional IC-property, namely, it reduces to a diagonal matrix at distributions with independent marginals. Scatter matrix is used to decorrelate the data and the eigenvalue decomposition of the spatial scatter matrix is used to find the unitary mixing matrix of the uncorrelated data. The method is a generalization of the FOBI algorithm, where a conventional covariance matrix and a certain fourth-order moment matrix take the place of the scatter and spatial scatter matrices, respectively. Emphasis is put on estimators employing robust scatter and spatial scatter matrices. The proposed approach is one among the computationally most attractive ones, and a new efficient algorithm that avoids decorrelation of the data is also proposed. Moreover, the method does not rely upon the commonly made assumption of complex circularity of the sources. Simulations and examples are used to confirm the reliable performance of our method.     

Downstream Hydrological Impacts of Hydropower Development in the Upper Mekong Basin

The Mekong River Basin in Southeast Asia is experiencing extensive hydropower development. Concerns have been raised about the consequences of the development for the ecosystems, livelihoods and food security in the region. The largest planned hydropower dam cascade in the basin, the Lancang-Jiang cascade, is currently under construction and already partly built into the Upper Mekong Basin, China. In this paper we assess the impact of the Lancang-Jiang cascade on downstream hydrology by using a combination of a hydrological model and a reservoir cascade optimization model. The hydrological changes were quantified in detail at the Chiang Saen gauging station in Thailand, the first gauge station downstream from the cascade, and in lesser detail at four other downstream locations in the Mekong mainstream. We found that on average the Lancang-Jiang cascade increased the December?CMay discharge by 34?C155?% and decreased the July?CSeptember discharge by 29?C36?% at Chiang Saen. Furthermore, the Lancang-Jiang cascade reduced (increased) the range of hydrological variability during the wet season (dry season) months. The dry season hydrological changes were significant also in all downstream gauging stations, even as far as Kratie in Cambodia. Thus the Mekong??s hydrological regime has been significantly altered by the Lancang-Jiang cascade, but what the consequences are for ecosystems and livelihoods, needs further study.     

Unbalanced magnetic pull induced by arbitrary eccentric motion of cage rotor in transient operation. Part 1: Analytical model

Eccentric rotor motion of an electric motor induces an unbalanced magnetic pull. This eccentricity force may couple the electromagnetic system with the flexural vibration modes of the shaft. This paper presents an analytic model for this eccentricity force allowing an arbitrary rotor motion and transient operation. The general equations were simplified for the constant flux and steady-state operation. These simplified equations correspond well to the results presented earlier.     

Pleasantness in relation to difference threshold of NaCl in mashed potato

Difference threshold values for sodium chloride were determined to investigate to what extent just noticeable differences (jnd) affect preferences. Samples were unflavored, garlic-flavored and pepper-flavored mashed potato. At the reference concentration of 0.60% NaCl, the jnd value for unflavored and garlic-flavored samples was 0.07% NaCl, and for the pepper-flavored sample, 0.08% NaCl. The pleasantness of seven samples between ±9 jnds from the reference (0.60% NaCl), was rated on a graphic scale ranging from less pleasant to more pleasant (reference at the midpoint). Forty-one subjects participated in the test. For unflavored and garlic-flavored mashed potato, concentrations below 0.36% NaCl and above 0.82% NaCl, and for pepper-flavored, below 0.31% NaCl and above 0.83% NaCl, were required to obtain statistically significant differences in hedonic responses compared to the reference concentration.