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.     

Chylomicron and VLDL TAG structures and postprandial lipid response induced by lard and modified lard

Alterations in chylomicron and VLDL TAG and the magnitude of postprandial lipemia were studied in healthy volunteers after two meals of equal FA composition but different TAG-FA positional distribution. Molecular level information of individual lipoprotein TAG regioisomers was obtained with a tandem MS method. The incremental area under the response curve of VLDL TAG was large (P=0.021) after modified lard than after lard. In plasma TAG, the difference did not quite reach statistical significance (P=0.086). In general, there were less TAG with palmitic acid in the sn-2 position and more TAG with oleic acid in the sn-2 position in chylomicrons than in fat ingested. From 1.5 to 8 h postprandially, the proportion of individual chylomicron TAG was constant or influenced by TAG M.W. VLDL TAG regioisomerism was similar regardless of the positional distribution of fat ingested. Significant alterations were seen in VLDL TAG FA, in M.W. fractions, and in individual regioisomers with respect to time. The TAG sn-14∶0-18∶1-18∶1+sn-18∶1-18∶1-14∶0, sn-16∶0-16∶1-18∶1+sn-18∶1-16∶1-16∶0, and sn-16∶1-18∶1-18∶1+sn-18∶1-18∶1-16∶1 decreased (P<0.05); and sn-16∶0-16∶0-18∶2+sn-18∶2-16∶0-16∶0, sn-16∶0-16∶0-18∶1+sn-18∶1-16∶0-16∶0, sn-16∶0-18∶1-16∶0, and sn-16∶0-18∶1-18∶2+sn-18∶2-18∶1-16∶0 increased (P<0.05) after both meals. In conclusion, positional distribution of TAG FA was found to affect postprandial lipid metabolism in healthy normolipidemic subjects.     

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.     

Factors affecting the development of biodeterioration in wooden constructions

Water leakages are the general cause of moisture stress exceeding the moisture tolerances of constructions. Moisture stress causes biodeterioration (mould, rot and insect damage) in wooden constructions. The degree of damage is affected by the severity and duration of moisture exposure and temperature, together with the sensitivity of the wooden construction to environmental stress. The growth of mould fungi on wooden materials depends mainly on the air humidity, temperature and the surface quality of wood. Long term humidity conditions above a relative humidity (RH) of 80% are a risk for mould growth in pine and spruce sapwood when the temperature is between +5°C and +50°C. Between −5°C and +5°C the growth of mould fungi is slow, and possible only when the relative humidity is above 90%. High nutrient content of the surface can stimulate the mould growth. In fluctuating humidity conditions, the severity and cumulative time of conditions suitable for mould growth are critical factors for the development of mould fungi in constructions. Humidity conditions must be above RH 95% (around the fibre saturation point of wood, wood moisture content about 25–30%) for the spore germination and mycelium activation of brown rot fungi. Under unsuitable conditions, fungi are inactive, but they can become active quickly under suitable conditions. The degree of decay in wood depends on the total time the decay organism is active. The natural durability of wood varies with the environmental conditions, wood characteristics (wood species, sapwood or heartwood, etc.) and the decay organisms. The service time of wooden materials can be extended by modification of the wood.

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Resume Les eaux d'infiltration sont, en général, responsables de la contrainte due à l'humidité dépassant le seuil de tolérance des constructions en bois. Le degré de détérioration est affecté par la sévérité et la durée de l'exposition à l'humidité et la température, ainsi que par la sensibilité de la construction en bois à la contrainte ambiante. Le développment de moisissures sur des matériaux en bois dépend surtout de l'humidité de l'air, de la température et de la qualité de la surface. Dans des conditions d'humidité à long terme supérieure à une humidité relative de 80%, des moisissures risquent de se développer dans le pin et l'aubier de sapin quand la température se situe entre +5°C et +50°C. Entre −5°C et +5°C, la croissance de champignons est lente et possible seulement si l'humidité relative dépasse 90%. Une teneur importante d'éléments nutritifs à la surface peut stimuler le développement de moisissures. Dans des conditions d'humidité fluctuantes, la réunion et l'accumulation dans le temps de conditions favorables à la croissance de champignons constitute un facteur critique de développement de moisissures. Les conditions d'humidité doivent dépasser une humidité relative de 95% (autour du point de saturation de la fibre, une teneur en humidité d'environ 25 à 30%) pour la germination du spore et l'activation du mycélium de champignons brun rouge. Dans des conditions défavorables, les champignons sont inactifs mais ils peuvent devenir rapidement actifs dans des conditions favorables. Le degré de détérioration du bois dépend de la vie active totale de l'organisme de décomposition. La durabilité naturelle du bois varie avec les conditions ambiantes, les caractéristiques du bois (espèce, aubier ou coeur) et les organismes de décomposition. La durée de vie du bois peut être allongée en le traitant.

     

Food control officers perception of the challenges in implementing new food control requirements in Finland

In addition to the food control officers’ former tasks, new EU and Finnish legislations have established new obligations for them, such as building up a quality system, amending a control plan and expanding the collection of fees to cover all the control targets. In order to study the implementation of these new tasks, an electronic survey was sent to the local food control officials in Finland. Our study shows that there will be significant differences in implementing the new food control requirements in Finland by our local units when we take into consideration the time of implementation, the approach and content of control plans, and the quality systems or fees. Especially the risk-based estimation of the control objects seems to have created a challenge in both the quality systems and in the control plans; in only 16% of the municipalities, the risk estimations had been calculated for each control object and in most cases, this estimation was made and the control frequency was decided on solely by their own inspector of the object alone. Furthermore, the amount of the planned fees per hour varied from 21 Euros to 45 Euros. Several respondents also expressed that they had no knowledge of the grounds for the charges of future inspections or the amount of fees. What is apparent is that the new approach will be implemented relatively slowly in Finland and there is a risk of the different treatment of business operators depending on their geographical location.     

Microstructural and electrical properties of multicomponent varistor ceramics with PbO–ZnO–B2O3 glass addition

Zinc oxide based ceramics are widely used materials in varistors because of their excellent nonlinearity. Traditionally these ceramics are sintered at high temperatures (about 1,100–1,300°C). In this work a novel zinc oxide-based material with a low sintering temperature (900–1,000°C) was investigated. This material can be used in varistors consisting of several ceramic layers with embedded silver/palladium thick-film electrodes. This paper explains the research procedure employed with this novel varistor material, including the effect of sintering aid addition on the final electrical properties and fired microstructure. The electrical properties achieved are compared to the values measured from the original zinc oxide composition without sintering aid addition. Especially the I–V characteristics, nonlinearity coefficient α, breakdown voltage V _bk and leakage current density J _L are investigated. The sintering properties are also reported. It was found that by adding 10 wt.% of glass and using a 900 °C sintering temperature, the material had good varistor characteristics, as V _bk = 378 V/mm, α = 33 and J _L  = 15 μA/cm². The investigated varistor material can be applied to protect electrical circuits against surges.     

Raw and processed fish show identical Listeria monocytogenes genotypes with pulsed-field gel electrophoresis

A total of 257 raw fish samples at two different sites were examined for the presence of Listeria monocytogenes. The prevalence of L. monocytogenes was 4%. From 11 positive samples, nine different L. monocytogenes pulsed-field gel electrophoresis genotypes were recovered. From nine pulsotypes recovered from raw fish and 32 pulsotypes shown by 101 fish product isolates, two raw fish and fish product pulsotypes were indistinguishable from each other. Although the prevalence of L. monocytogenes in raw fish is low, the range of L. monocytogenes strains entering the processing plant in large amounts of raw material is wide. This indicates that the raw material is an important initial contamination source of L. monocytogenes in fish processing plants. This postulation is supported by the identical pulsotypes recovered from both raw and processed fish. Some L. monocytogenes strains entering a plant may thus contaminate and persist in the processing environment, causing recurrent contamination of the final products via processing machines.     

MROS-68K,a memory resident operating system,for MC68000

The operating system described has been designed and implemented for use in dedicated one-purpose applications, typically in real tihe. Specific attention has been paid to flexible intertask contkol. In the first installation the application system was the steering and controlling of large hydraulic devices. Typical subtasks involved were measuring, coordinate transformations, control, teaching and following robotic paths and evaluating daily material transfkrs. As a programming effort, developing the operating system was fairly reasonable being of the order of three or four months for one person, including design, coding, testing and documentation.