Distributed agro-hydrological modeling with SWAP to improve water and salt management of the Voshmgir Irrigation and Drainage Network in Northern Iran

The agro-hydrological model SWAP was used in a distributed manner to quantify irrigation water management effects on the water and salt balances of the Voshmgir Network of North Iran during the agricultural year 2006-2007. Field experiments, satellite images and geographical data were processed into input data for 10 uniform simulation areas. As simulated mean annual drainage water (312 mm) of the entire area was only 14% smaller than measured (356 mm), its distribution over the drainage units was well reproduced, and simulated and measured groundwater levels agreed well. Currently, water management leads to excessive irrigation (621-1436 mm year⁻¹), and leaching as well as high salinity of shallow groundwater are responsible for large amounts of drainage water (25-59%) and salts (44-752 mg cm⁻²). Focused water management can decrease mean drainage water (22-48%) and salts (30-49%), compared with current water management without adverse effects on relative transpiration and root zone salinity.     

Relationship between esterase isozymes and some agronomic traits in F<Subscript>2</Subscript> populations derived from the crossing of Milyang 23 and Ashahi

Esterase isozymes in the leaf blade were observed in the F₂ populations derived from the cross combination between a japonicaindica hybrid rice variety with EIZ 1 (EST ₁ , EST ₂ ^S , EST ₃ ^F ) and a japonica rice variety with EIZ 6 (EST ₁ , EST ₂ ^O , EST ₃ ^S . The esterase isozyme of the 6A (EST ₂ ^S band was controlled by a dominant allele, while the esterase isozymes of 12A (EST ₃ ^S and 13A (EST ₃ ^F ) bands were controlled by codominant alleles. No linkage relation was indicated while between EST ₂ and EST ₃ . The presence of esterase isozyme of 13A (EST ₃ ^F ) band is related to the grain shedding habit and esterase isozyme of 13A (EST ₃ ^F ) band itself is somewhat related to the cracking characteristics of the abscission layer. The presence of esterase isozyme of 6A (EST ₂ ^S ) band is related the days to heading and it might due to the panicle length and ratio of fertility. There was no difference in the plant height, culm length, and number of tillers per hill between EIZ in the F₂ population. Therefore, there were the relationships between esterase isozymes and some agronomic traits in rice plants.     

Inheritance of grain shedding and abscission layers in the cross combination between rice varieties

Seed shattering is an undesirable characteristic of rice cultivars affecting the loss of grain yield before and during harvesting. These grain losses are influenced by varietal characteristics. The histological peculiarities of the abscission region obtained were different among rice varieties, and had a close relationship with grain shedding. In order to obtain information for the breeding of new persistent shedding varieties, this study was designed to clarify the inheritance of grain shedding habits in relation to the abscission layer. In the cross combination of two easily shedding varieties, Milyang 23, a japonica-indica hybrid rice with cracked abscission layers and Ashahi, a japonica-type rice with uncracked abscission layers, the cracking of parenchymatous cells in the abscission layer was controlled by a single dominant gene. The breaking tensile strength coincided well with cracked and uncracked abscission layers. In four crosses between a persistent shedding variety without abscission layers and two easily shedding varieties with cracked abscission layers, and two medium shedding varieties with uncracked abscission layers, respectively, the formation of the abscission layer was controlled by a single dominant gene. The easily shedding and persistent shedding habits coincided well when the abscission layers were both present and absent. The easily shedding characteristics were dominant in cross combination. The close negative correlations were recognized between degrees of grain shedding and breaking tensile strengths.     

Phosphorylated human lectin galectin-3: analysis of ligand binding by histochemical monitoring of normal/malignant squamous epithelia and by isothermal titration calorimetry

The human lectin galectin-3 is a multifunctional effector with special functions in regulation of adhesion and apoptosis. Its unique trimodular organization includes the 12-residue N-terminal sequence, a substrate for protein kinase CK1-dependent phosphorylation. As a step towards elucidating its significance, we prepared phosphorylated galectin-3, labelled it and used it as a tool in histochemistry. We monitored normal and malignant squamous epithelia. Binding was suprabasal with obvious positive correlation to the degree of differentiation and negative correlation to proliferation. The staining pattern resembled that obtained with the unmodified lectin. Basal cell carcinomas were invariably negative. The epidermal positivity profile was akin to distribution of the desmosomal protein desmoglein, as also seen with keratinocytes in vitro . In all cases, binding was inhibitable by the presence of lactose, prompting further investigation of the activity of the lectin site by a sensitive biochemical method, i.e. isothermal titration calorimetry. The overall affinity and the individual enthalpic and entropic contributions were determined. No effect of phosphorylation was revealed. This strategic combination of histo- and biochemical techniques applied to an endogenous effector after its processing by a protein kinase thus enabled a detailed monitoring of the binding properties of the post-translationally modified lectin. It underscores the value of using endogenous lectins as a histochemical tool. The documented approach has merit for applications beyond lectinology.     

Are cadmium, lead and mercury concentrations in mosses across Europe primarily determined by atmospheric deposition of these metals?

Purpose

This study aimed at investigating correlations between heavy metal concentrations in mosses and modelled deposition values as well as other site-specific and regional characteristics to determine which factors primarily affect cadmium, lead and mercury concentrations in mosses. The resulting relationships could potentially be used to enhance the spatial resolution of heavy metal deposition maps across Europe.

Materials and methods

Modelled heavy metal deposition data and data on the concentration of heavy metals in naturally growing mosses were integrated into a geographic information system and analysed by means of bivariate rank correlation analysis and multivariate decision trees. Modelled deposition data were validated annually with deposition measurements at up to 63 EMEP measurement stations within the European Monitoring and Evaluation Programme (EMEP), and mosses were collected at up to 7,000 sites at 5-year intervals between 1990 and 2005.

Results and discussion

Moderate to high correlations were found between cadmium and lead concentrations in mosses and modelled atmospheric deposition of these metals: Spearman rank correlation coefficients were between 0.62 and 0.67, and 0.67 and 0.73 for cadmium and lead, respectively (p?<?0.001). Multivariate decision tree analyses showed that cadmium and lead concentrations in mosses were primarily determined by the atmospheric deposition of these metals, followed by emissions of the metals. Low to very low correlations were observed between mercury concentrations in mosses and modelled atmospheric deposition of mercury. According to the multivariate analyses, spatial variations of the mercury concentration in mosses was primarily associated with the sampled moss species and not with the modelled deposition, but regional differences in the atmospheric chemistry of mercury and corresponding interactions with the moss may also be involved.

Conclusions

At least for cadmium and lead, concentrations in mosses are a valuable tool in determining and mapping the spatial variation in atmospheric deposition across Europe at a high spatial resolution. For mercury, more studies are needed to elucidate interactions of different chemical species with the moss.     

Acute changes in the concentrations of prostaglandin F2α (PGF) and cortisol in uterine and ovarian venous blood during PGF-induced luteolysis in cows

Prostaglandin F2α (PGF) is considered to be the main luteolysin in cattle. We have previously demonstrated that cortisol (Cr) suppresses PGF production in non-pregnant bovine endometrium. This study was carried out to test whether exogenous PGF increases ovarian and/or uterine PGF production and to determine the temporal relationship between PGF and Cr in ovarian and uterine circulations during PGF-induced luteolysis in cows. Catheters were inserted into the ovarian vein (OV), uterine vein (UV) and jugular vein (JV) of 10 cows on Day 9 of the oestrous cycle (Ovulation = Day 0) for frequent blood collection. On Day 10, the cows were divided randomly into two groups and treated with a luteolytic dose of a PGF analogue (cloprostenol) or saline solution. Blood samples were collected at -0.25, 0, 0.25, 0.5, 1 and 2 h and then at 2-h intervals until 12 h after treatment (0 h). The basal concentrations of PGF and Cr in OV and UV plasma were not significantly different. Injection of a PGF analogue induced more than twofold increases in the levels of PGF between 0.25 and 1 h in UV plasma, but not in OV plasma. PGF increased (p < 0.05) the concentrations of Cr in OV, UV and JV plasma between 0.5 and 1 h. The Cr levels in OV, UV and JV plasma were similar. The PGF levels in UV plasma decreased after Cr reached its highest levels. The overall results suggest that the uterus rather than the ovary increases PGF production in response to PGF injection. Based on the temporal changes of PGF and Cr in the ovarian and uterine circulations, Cr may act to reduce uterine PGF production in non-pregnant cows in vivo.     

Simulation of food and oxygen limitations on the growth of Nile tilapia, Oreochromis niloticus L., in fishponds

A model for dynamic simulation of the growth of the Nile tilapia, Oreochromis niloticus (L.), in relation to food amount and composition, temperature, and dissolved oxygen concentration was applied to tilapia ponds. To model food competition between stocked fish and fingerling recruits, a pond food module was added. Data for model calibration were from uniform experiments with all-male O niloticus ponds fertilized with inorganic fertilizers and chicken manure in Honduras, Rwanda and Thailand. Calibration consisted of iterative determination of two model parameters: (1) CONLEV, the consumption rate without food or oxygen limitations; and (2) TPFS, the total daily food supply by the pond. Calibration results showed that, in most ponds, final fish weight could be simulated with acceptable values for CONLEV and TPFS. Both CONLEV and TPFS were related to natural productivity indicators (net primary production and chlorophyll a concentration). For each pond, an estimate of the degree of food and/or oxygen limitation could be given. Validation of the model with independent data from Indonesia and Panama was unsuccessful. The relationships used to estimate values of CONLEV and TPFS from primary productivity measurements were not satisfactory. A more detailed approach to modeling food competition and oxygen limitation under these conditions is necessary. The model provides a conceptual framework for the analysis of fish growth in ponds, tying together effects of food quantity and composition, temperature, and dissolved oxygen concentration.     

Changing sediment dynamics due to natural reforestation in the Dragonja catchment,SW Slovenia

Under the influence of socio–economic changes in many regions in Europe, a trend of decreasing agricultural activity has been observed since the Second World War. The resulting reforestation profoundly changes water and sediment supply to river channels, deposition rates on the floodplains and erosion rates on the hillslopes. We studied these changes in the 91 km² Dragonja catchment in southwestern Slovenia.     

The impact of salinity on paddy production and possible varietal portfolio transition: a Vietnamese case study

Paddy and Water Environment - Increasing soil salinisation is an environmental stressor that causes significant reduction in crop productivity and increases the risk of farming and hence reduces...