Determination of iron absorption by rat bioassay. Evaluation of methods of dosing59Fe on radioiron absorption from plant diets

We studied the potential of an animal model to predict nonheme iron absorption in humans and tested a feasible and easy technique of dosing⁵⁹Fe to evaluate bioavailability of dietary nonheme iron. Plant diets containing about 20 ppm or 75 ppm iron were the nonheme iron sources with ferrous sulfate (75 ppm) as a reference. Radioiron was administered by (a) gavaging in water, 1 h after a meal; (b) mixing with the meal; and (c) making a slurry with the meal and gavaging. No significant differences were found (P0.05) in⁵⁹Fe absorption among the three methods of administering radioiron. Absorption of⁵⁹Fe was similar to apparent iron absorption for all diets tested, whether the animals consumed the same diet as that of the test meal or a different diet. A high correlation (r=0.88) obtained between the apparent iron absorption and⁵⁹Fe iron absorption for different dosing techniques, indicates that extrinsic iron tag administered by any of these methods is valid to measure nonheme iron absorption. Apparent iron absorption values determined by rats fed 20 ppm or 75 ppm dietary iron from plant sources were similar to reported values for humans. It is concluded that the normal adult rat is an appropriate model to study iron bioavailability of human foods when iron status, maturity, iron intake relative to requirement, and method of measurement are similar to the human situation.     

Hydraulic properties of Eucalyptus grandis in response to nitrate and phosphate deficiency and sudden changes in their availability

Some herbaceous plant species have been shown to dynamically alter the hydraulic properties of their roots in response to sudden changes in the concentrations of mobile nutrients. These hydraulic adaptations effectively allow plants to ‘chase' mobile nutrients across the rhizosphere. Trees, on the other hand, could mitigate effects of heterogeneous, dynamic soil environments with extensive root systems as such systems would effectively equalize nutrient availability. In addition, large dendritic root systems would reduce the effectiveness of rapid, localized, physiological hydraulic changes as these local changes might cancel each other at lower‐order root junctions. Thus, the aim of this study was to determine if trees (Eucalyptus grandis) employ short‐term (minutes to hours), physiological hydraulic changes or rely on long‐term (days), growth‐based hydraulic acclimations to enhance mobile nutrient uptake. We used two nutrients, nitrogen (N) and phosphorus (P), that are characterized by contrasting soil mobility: N being mobile and P immobile. Transpiration, whole‐plant hydraulic resistance (liquid phase), and the hydraulic resistance of single roots of E. grandis plants grown in high and low N combined with high and low P availability were measured. In general, plants grown with high N availability had lower whole‐plant hydraulic resistance than plants grown with low N availability. When N or P were in short supply, a sudden addition of N or P did not change either single‐root or whole‐plant hydraulic resistance at a given leaf water potential. However, addition of N reduced the transpiration rate, thus, enhancing plant water status, suggesting that E. grandis behavior prioritizes water conservation over N uptake in short‐term. Prolonged exposure to low nutrient availability resulted in high overall hydraulic resistance further suggesting prioritization of water conservation over N gain.     

The effect of feeding on morphological changes in intestine of pike-perch (Sander lucioperca L.)

The pike-perch (Sander lucioperca L) at the age of 18 days were fed for 21 days with three different diets: Aglo Norse (AN), casein-gelatin (Cas), cod meal with gelatin (Mac) and nauplius Artemia salina (Art—control diet). On the last day of the experiment, fish fed Art and AN diets had the statistically significant highest body mass, length, and survival. On the last day of the experiment, pikes fed Cas diet had the lowest folds of the anterior and posterior intestine. In the anterior intestine of fish fed Cas diet was found a statistically significant increase in the proliferation of the enterocytes as compared with fish from other feeding groups. The fish from Mac-feeding group had the largest statistically significant total area of enterocytes and the absorption area of posterior intestine. This was probably the effect of disorders in the intracellular digestion and the stoppage in transportation of the intracellular digestion products into the circulatory system. Moreover, there was found the intensive processes of apoptosis of enterocytes in the fish fed Mac. On the last day of the experiment, fish fed Art and AN had statistically significantly more cells secreting cholecystokinin and gastrin (Gas) as compared with fish from other feeding groups. Results indicate that juvenile pike-perch can be reared and fed commercial diet AN since its 18th day after hatching. Feeding pike-perch Cas and Mac diets did not satisfy nutritional needs of fish, resulting in low survival, growth rate, and pathological changes in the intestine.     

Cereal leaf beetles (Oulema spp., Coleoptera: Chrysomelidae) control following various dates of wheat sowing and insecticidal treatments

In this paper, we report the sowing date and intensity of chemical control on presence of the cereal leaf beetles (CLB) on spring wheat. The CLB monitoring (Oulema melanopus L. and Oulema gallaeciana Voet.) was conducted in May–June of each year, following the announcement of the IOR-PiB in Poznań (Institute of Plant Protection, National Research Institute), that economic threshold levels in Poland of this pest is observed. For the spring sowing dates between (20 March–20 April) and late autumn sowings (21 November–7 December) larger amounts of CLB adults (1.6–1.1) in comparison to early autumn sowings (25 October–02 November) were noticed (0.4). Following the insecticidal seed treatment with imidacloprid, the occurrence of adults was 0.2–0.7 individual per stem, while the use of fungicidal treatment with triadimenol–imazalil–fuberidazol resulted in average 1.1–2.2 individual per stem. The reduction in the number of larvae per stem was 7–10 fold larger following the foliar application (pirimicarb + dimethoate + cypermethrin) compared to the seed treatment with imidacloprid. The lowest grain yield (3.83 t ha^?1) from the spring crop without any insecticide was obtained. Foliar application with blend of pirimicarb + dimethoate + cypermethrin increased the yield crop by 0.41 t ha^?1 (10.7%) and additionally by 0.78 t ha^?1 (20.4%) to compare to the fungicidal control when imidacloprid was used. Wheat seed treatment with imidacloprid and sowing date in autumn showed to be suitable and economically efficient preventive strategies for controlling the pest population.     

Use of Ceramic Membranes in a Membrane Filtration Supported by Coagulation for the Treatment of Dairy Wastewater

Water, Air, & Soil Pollution - A novel adsorbent was prepared by introducing xanthate group onto pristine multi-walled carbon nanotubes (MWCNTs) for removing Pb (II) from aqueous solution. The...     

Effect of Diet Supplemented with Quinoa Seeds on Oxidative Status in Plasma and Selected Tissues of High Fructose-Fed Rats

Oxidative stress plays an important role as a mediator of damage produced by fructose metabolism. This work was designed to investigate the effect of diet supplemented with quinoa seeds on oxidative stress in plasma, heart, kidney, liver, spleen, lung, testis and pancreas of fructose administered rats. Fructose administration (310 g/kg fodder for 5 weeks) caused oxidative stress that was manifested by the increase in plasma malondialdehyde (MDA) (p<0.05), and by the non-significant changes in the enzymatic antioxidant potential in plasma and most of tissues. Co-administration of quinoa seeds (310 g/kg fodder) maintained normal activities of some enzymes. It also influenced the oxidative stress as was evidenced by decreasing MDA in plasma, and decreasing the activities of antioxidant enzymes (erythrocyte superoxide dismutase - eSOD, catalase -CAT, plasma glutathione peroxidase - pGPX). These findings demonstrate that quinoa seeds can act as a moderate protective agent against potential of fructose-induced changes in rats by reducing lipid peroxidation and by enhancing the antioxidant capacity of blood (plasma) and heart, kidney, testis, lung and pancreas.     

Scots pine (Pinus sylvestris L.) roots and soil moisture did not affect soil thermal sensitivity

Through their effects on microbial metabolism, temperature and moisture affect the rate of decomposition of soil organic matter. Plant roots play an important role in SOM mineralization and nutrient cycling. There are reports that rhizosphere soil exhibits higher sensitivity to temperature than root-free soil, and this can have implications for how soil CO₂ efflux may be affected in a warmer world. We tested the effects of 1-week incubation under different combinations of temperature (5, 15, 30 ^°C) and moisture (15, 50, 100% WHC) on the respiration rate of soil planted with Scots pine and of unplanted soil. Soil respiration in both soils was the highest at moderate moisture (p < 0.0001) and, increased with temperature (p < 0.0001). There was also marginally significant effect of soil kind on respiration rate (p < 0.055), but the significant interaction of temperature effect with soil kind effect, indicated, that soil respiration of planted soil was higher than unplanted soil only at 5 ^°C (p < 0.05). The soil kind effect was compared also as Q₁₀ coefficients for respiration rate, showing the relative change in microbial activity with increased temperature. However, there was no difference in the thermal sensitivity of soil respiration between planted and unplanted soils (p = 0.99), irrespective of the level of soil moisture. These findings were similar to the latest studies and confirmed, that in various models, being useful tools in studying of soil carbon cycling, there is no need to distinguish between planted and unplanted soil as different soil carbon pools.     

Influence of stocking density and type of feed on the rearing of crucian carp, <Emphasis Type="Italic">Carassius carassius</Emphasis> (L.), larvae under controlled conditions

Two experiments were conducted into the rearing of crucian carp larvae under controlled conditions in an experimental closed water system. In both cases, the rearing lasted 21 days. The first experiment concerned the initial stocking density (from 50 to 600 individuals per l), whilst the second one studied the first food offered (two types of Artemia nauplii, decapsulated Artemia cysts and three types of commercial feeds) which were applied at the moment of exogenous feeding commencement. The best results were obtained using 50 larvae per l, whilst there were no significant differences within the range 200–600 larvae per l. The application of dry feed had a negative influence on the survival and other parameters. The highest survival rate was found in the groups fed with freshly hatched Artemia naupli. The results obtained indicate that the rearing of crucian carp larvae may be successfully conducted in very high stocking densities. However, the very high sensitivity of crucian carp larvae to the type of food offered during the initial days of life should be taken into account. The data presented in this article could be very useful in crucian carp larviculture.     

Assessing water-related plant traits to explain slow-wilting in soybean PI 471938

Soybean [Glycine max (L.) Merr.] genotype PI 471938 expresses a slow-wilting phenotype in the field, and the progeny of this genotype have shown to have high yield under water deficit conditions. However, the physiological basis for the slow-wilting trait in PI 471938 remains unclear, and failure to understand the causal mechanism may limit future breeding efforts. This study investigated three primary hypotheses for trait expression that could explain slow-wilting trait in PI 471938: (1) a low osmotic potential in the leaves allowing greater water retention, (2) high elastic modulus of leaves resulting in delayed development of wilting, and (3) high hydraulic conductance allowing rapid water redistribution in the plants. Experiments included three other soybean genotypes as references for the results obtained with PI 471938. Surprisingly, the results for PI 471938 did not prove to be unique as compared to the other three tested genotypes for any of the three hypotheses. These negative results indicate that a hypothesis outside the usual candidates describing plant water transport, possibly anatomical features related to specific water transport properties, is required to explain slow-wilting in PI 471938.