Simulation of runoff and phosphorus transport in a Carpathian catchment,Slovakia

A comprehensive, GIS‐based modelling approach is developed to estimate runoff and phosphorus transport within a watershed at a daily time step. The approach relies on the use of GIS data for deriving major critical model parameters that exhibit distinct spatial variability over the catchment. Surface runoff is calculated by a modified rational method, which depends upon rainfall intensity, soil moisture status, slope, land‐use and soil characteristics. Phosphorus loading is estimated as a function of the runoff volume and the event mean concentration for different land use categories. A diffusive approximation method is used to trace runoff and phosphorus transport to the basin outlet. The modelling approach is tested in the Margecany catchment, Hornad River basin, Slovakia, to simulate runoff, phosphorus loading, and its transport on a daily time scale using data observed between 1995 and 2000. Satisfactory results of the hydrographs and phosphorus concentration at the basin outlet are obtained, though more efforts regarding the phosphorus cycling and its biochemical reactions need to be clarified by further research. Copyright © 2006 John Wiley & Sons, Ltd.     

龙江县地下水水质评价

通过评价龙江县地下水的生活用水、工业用水、农田灌溉用水,提出了生活用水应采取除铁措施,氟离子含量过高造成的危害及治理措施,农田灌溉用水需作增温处理等措施与建议。     

Assessment of Informativeness of Groundwater Monitoring in Developing Regions (Gaza Strip Case Study)

Groundwater resource management and planning requires appropriate and accurate data. These data, which can be collected by monitoring networks, may contain too little, enough or redundant information. This study aims to evaluate the monitoring cycle in the Gaza Strip (a developing region) using the entropy theory. The approach employed in this study involves gathering data needs for groundwater resource management and planning in the Gaza Strip) through a questionnaire (survey). The questionnaire outlined the groundwater management and planning objectives, tasks and the data which had to be collected through monitoring activities in the Gaza Strip (monitoring cycle). This article also proposes a flowchart, which is used to evaluate the relation between the objectives, the tasks, the data and the monitoring activities using the entropy theory. The evaluation affirms the informativeness of the collected data when they contain enough, too little or redundant information. From this study it can be concluded that in the Gaza Strip the institutional set-up of the water sector needs to be strengthened, and more data should be collected and the existing monitoring networks should be redesigned for the informativeness of the data.     

Nitrate Accumulation and Other Components of the Groundwater in Relation to Cropping System in an Aquifer in Southwestern Spain

Inappropriate farming techniques and 4 years of drought (1992–1995) produced conditions for high nitrate concentration in an aquifer located in the Province of Seville (Southwest Spain). The objectives of this study were to study groundwater components and to determine the relationship between the cropping system and nitrate concentrations in groundwater. From October 1994 to May 1996, 16 groundwater samples were obtained from a network of 35 sample points. Groundwater concentrations were analysed by multivariate statistical techniques (factor and cluster analysis). Two factors were found: firstly, agricultural pollution and secondly, salinization (from natural mineralization of groundwater and from anthropogenic effects). High levels of NO_3– were closely associated with intensive cotton (Gossypium herbaceum L.) and potato production (Solanum tuberosum L.). The salinization factor includes electrical conductivity, Cl_–, Na₊, Ca_{2 +}, Mg_{2 +}, SO_{42 –} and HCO_3–. Our study permits the impact of crops on groundwater to be determined. In comparison to the other crops, cotton (Gossypium herbaceum L.) and potato (Solanum tuberosum L.) made the greatest contribution to nitrate pollution and salinization. Use of the groundwater for human consumption in drought periods could represent a public health risk. Alternative farming techniques for these crops such as monitored fractional fertilization and controlled irrigation are recommended.     

Phosphate inhibition on thermophilic acetoclastic methanogens: a warning.

The inhibitory effect of phosphate on acetoclastic-methanogens was investigated for three different thermophilic (55 degrees C) anaerobic consortia. When 70 mM of phosphate was tested, acetoclastic methanogens was completely inhibited in "Eerbeek" sludge which is dominated by Methanosaeta-like methanogens. For the "Hoogezand" sludge the specific methanogenic activity dropped by 79%, indicating that any of the acetate-consuming methanogens present in the sludge was more resistant to the phosphate applied. The results demonstrated that the inhibitory effect of phosphate may affect both methane production rate and final methane concentration and might also be time dependent. This study indicates that the degree of inhibition is species-dependent, and even more resistant species may be affected during long-term experiments. Such inhibition is a matter of concern for researchers since misleading conclusions might be taken from growth and specific methanogenic activity tests when considerable concentrations of phosphate buffer are used and no interference is expected.     

Limnology and culture-based fisheries in non-perennial reservoirs in Sri Lanka

This study was carried out to investigate the possibility of using the limnological characteristics of non‐perennial reservoirs in Sri Lanka for the future management of culture‐based fisheries. Forty‐five reservoirs were randomly selected to study their limnology, out of which 32 were stocked with fish fingerlings of Chinese and Indian carps, tilapia and freshwater prawn at stocking densities ranging from 218–4372 fingerlings ha^?1. Of these, 23 reservoirs were harvested at the end of the culture period (6–10 months). Thirteen limnological parameters were measured during the water retention period of each of the 45 reservoirs between November 2001 and January 2004. The mean values of the limnological parameters were used to ordinate the reservoirs through principal component analysis. Ordination showed a productivity gradient among reservoirs where Secchi disc depth, total phosphorus, chlorophyll‐a, inorganic turbidity and organic turbidity were identified as key factors. The total fish yield of culture‐based fisheries was positively correlated to the scores of the first principal component axis. This study reveals that it is possible to classify non‐perennial reservoirs in Sri Lanka based on the above limnological parameters in order to develop culture‐based fisheries and that they could be applicable in comparable water bodies elsewhere in the tropics.     

On the presence of Inulin and Oligofructose as natural ingredients in the western diet

The classic definitions of inulin and oligofructose are constructively criticized. It is observed that inulin cannot unequivocally be described as a polydisperse 1‐kestose‐based (GF_n) β(2 ? 1) linear fructan chain, but that inulin always contains small amounts of F_m and branched molecules. This review article describes the presence of inulin and oligofructose in common foodstuffs. Historical data on human consumption add an extra dimension.

Modern analytical techniques (HPLC, LGC, HPAEC‐PAD) are used to check the variety of data mentioned in the literature throughout the past century. Methods to determine inulin and oligofructose in natural foodstuffs (cereals, fruit, and vegetables) are optimized and used to determine the loss of inulin during storage and during preparation of the food.

These findings allow quantification of the amount of inulin and oligofructose in the average daily western diet. The daily per capita intake is estimated to range from 1 to 10 g, depending on geographic, demographic, and other related parameters (age, sex, season, etc.).

Inulin and oligofructose are not measured by classic methods of dietary fiber analysis and consequently are often not mentioned in food tables. Their significant contribution (1 to 10 g/d/per capita) to the dietary fiber fraction (recommended at 25 g/d/per capita) is not taken into account in any nutritional recommendations. In view of this, inulin and oligofructose deserve more attention, both in food composition tables and in diet or nutrition studies.     

In vitro kinetic analysis of carbohydrate and aromatic amino acid metabolism of different members of the human colon

The carbohydrate and aromatic amino acid metabolism of several species related to the human colon was investigated into more detail. Therefore, in vitro fermentations were performed, with different carbohydrate sources, during which several aromatic amino acids were added to the fermentation medium. Shifts in end-product formation in response to the available nutrients were observed for all strains tested. The major part of amino acid degradation occurred after depletion of the carbohydrates. Moreover, it was shown that Bifidobacterium strains are capable of degrading aromatic amino acids in the absence of carbohydrates. The excretion of certain intermediates of the aromatic amino acid metabolism was observed for a strain of Clostridium clostridioforme, after which they were metabolized again during a later stage of fermentation. This implies that cross-feeding on degradation products of aromatic amino acids, albeit within the same species, can occur in the human colon.     

Comparison of the compositional, microbiological, biochemical and volatile profile characteristics of three Italian PDO fermented sausages

Three Italian PDO fermented sausages, Varzi, Brianza and Piacentino, were compared for compositional, microbiological, biochemical and volatile profile characteristics. Mean values for the gross composition varied especially due to moisture, fat, total protein and nitrate concentration which reflected differences in the ingredients and some technological parameters. Cell numbers of the major microbial groups were almost similar among sausages. The major differences were found for Brochothrix thermosphacta, enterococci and moulds. Apart from their use as starters, Lactobacillus sakei and Lactobacillus curvatus were the dominant lactic acid bacteria and, as well as Staphylococcus xylosus, dominated the population of coagulase-negative staphylococci. Sausages differed for the hydrolysis of myofibrillar proteins and secondary proteolysis. Varzi, the sausage subjected to prolonged fermentation at 23–25 °C for 10 days before ripening, showed the highest degree of secondary proteolysis. Varzi and Brianza, the two fermented sausages manufactured by using microbial starters, showed the highest concentration and similar profiles of free amino acids. The peptidase activities contained in the aqueous extracts agreed with the above findings. A total of 52 volatile components, mainly alcohols, aldehydes and terpenes, were identified by solid-phase micro-extraction coupled with gas chromatography–mass spectrometry analysis. The volatile profiles of the three Italian PDO fermented sausages differed in part and, except for terpenes, the highest levels of the other chemical classes were found in Varzi and Brianza sausages. The composition of free fatty acids of the three Italian PDO sausages was rather similar. Monounsaturated fatty acids (MUFA) were found at the highest relative percentage followed by saturated (SFA) and polyunsaturated (PUFA) fatty acids. Oleic, palmitic, linoleic and stearic were the main free fatty acids found in all fermented sausages.