Application of shallow water equations to analyze runoff processes in hilly farmlands

Analysis of runoff processes in farmlands during storm events in particular is an important engineering topic. The shallow water equations describing the physical conservation laws are attractive tools for understanding motion of surface water. A numerical model is developed to reproduce surface water flows during storm events, using the finite element method and the finite volume method applied to the one-dimensional shallow water equations. The numerical model has the advantage of dealing with transcritical flows, wet, and dry processes, irregular channel bed slopes, and channel junctions involving multiply connected networks. Standard numerical tests demonstrated some of these features. Runoff processes from farmlands in a Japanese hilly area is analyzed with the numerical model coupled with another runoff model of black-box type. Parameters of the models are calibrated and validated using observed series of rainfall and runoff discharge data. Simulated results included submergence of hydraulic jumps and flood storage in farming plots, which are very informative in terms of assessing diverse functions of the farmlands.     

Withdrawal strength of nailed joints with decay degradation of wood and nail corrosion

Nailed timber joints are widely used in timber structures, and their deterioration may cause significant damage. We investigated the withdrawal strength of joints using steel wire nails in specimens exposed to a brown-rot fungus. We also examined the effects of nail corrosion on withdrawal strength, because high humidity conditions accelerate not only wood decay but also the corrosion of nails. We found that nail corrosion increased the withdrawal strength. The ratios of withdrawal strength of nailed joints with rusted nails to that of joints with a minimally rusted nails were 1.47 and 1.56 in joints nailed in radial and tangential directions to annual rings, respectively. Withdrawal strength, excluding the effects of nail corrosion, had a negative correlation with mass loss and Pilodyn-pin-penetration-depth-ratio. We estimated the withdrawal strength of the nailed joint with decayed wood and rusted nails by multiplying the values from the empirical formula (obtained from mass loss and Pilodyn-pin-penetration-depth-ratio) by 1.47 and 1.56 for joints nailed in radial and tangential direction to annual rings, respectively.     

The assessment of biodiversity loss over time: wild legumes in Syria

The conservation community has been set a considerable challenge by way of the CBD (Convention on Biological Diversity) 2010 targets. This may not be achievable by 2010 as demanded by the CBD, but at least methodologies can be assessed with a view to their implementation, so that loss of biodiversity and its inherent genetic diversity can be reduced post 2010. There is therefore a need to develop and implement protocols to efficiently measure genetic erosion and to make the identification of the drivers of erosion clear enabling counter-measures to be taken. In this paper the applicability of the indirect genetic erosion threat assessment for wild populations of rare and endemic Vicia species has been investigated. The method applied was based on the scoring of 18 factors perceived to be threats in the 18 study sites in two regions of Syria. Both temporal and spatial patterns of genetic erosion were considered. The method clearly detected spatial patterns of threat, enabling discrimination between the study sites located in the two study regions. However, no significant variation among the sites within each region was detected, highlighting the restricted spatial resolution of the method. Most importantly the results were in agreement with population demographic change observed, confirmed by a highly significant correlation between the erosion threat score and the relative population size change over the last 20 years. The results confirm the great potential of indirect genetic erosion threat assessment in routine evidence-based wild plant conservation decision-making.     

Fecal progesterone analysis by time-resolved fluoroimmunoassay (TR-FIA) for monitoring of luteal function in the sika doe (Cervus nippon centralis)

Fecal progesterone content was measured by time-resolved fluoroimmunoassay (TR-FIA) in the sika doe (Cervus nippon). The total recovery rate of fecal progesterone by twice extraction with diethylether was about 60%. The displacement curve of TR-FIA with serial doses of fecal extract (0.156-5.0 mg feces) was closely parallel to that of the reference standard. Fecal progesterone content was correlated with that of plasma (r=0.829, n=16), but the values were 100-fold higher in feces than in plasma. Fecal progesterone content periodically changed during the breeding season suggesting the estrous cycle in the doe. The fecal progesterone content was higher between the estruses, and decreased after estrus. The time between the onset of estrous signs and the lowest fecal progesterone content was 1-2 days suggesting the time required for hepatic metabolism and intestinal passage. Fecal progesterone content was also decreased around the time of vaginal discharge. The discharge took place within a few days, suggesting a short luteal phase. Not of all decreases in fecal progesterone values were preceded by estrous behavior or vaginal discharge. Fecal progesterone content was further increased in pregnancy rather than in the preceding estrous cycle and the levels were maintained up to term. These results suggest that fecal progesterone measurement is a useful tool for non-invasive analysis of luteal function in the sika doe. The TR-FIA kit, designed for the human hospital market, was shown to be successfully utilized for fecal assay in the sika doe with minor modifications.     

Biocides, tributyltin and triphenyltin, as possible inhibitors of the human sulfotransferase involved in the estrogen homeostasis

This work using purified recombinant human estrogen sulfotransferase (hSULT1E1) aimed to investigate the mechanism of the inhibition of estrogen sulfation by organotin compounds. Tributyltin (TBT) inhibited the sulfation of estrone (E1) and 17 β-estradiol (E2) by hSULT1E1 competitively, with IC₅₀ values of, respectively, 3 and 12 μM. The sulfation of E1 and E2 was also inhibited competitively by triphenyltin (TPT), with IC₅₀ of, respectively, 10 and 5 μM. These data strongly suggested that His¹⁰⁷ residue might act as a ligand to establish a coordination bond with organotins at estrogen binding site in hSULT1E1. A more surprising finding was that TBT competed with 3′-phosphoadenosine 5′-phosphosulfate (PAPS), indicating that TBT may coordinate with certain amino acid residue such as Lys⁴⁷ at the PAPS binding site of hSULT1E1. Taken together, these data provided clear evidence that TBT and TPT have a capacity to disrupt endocrine-mediated events by inhibiting hSULT1E1 involved in the metabolism of sex steroids.     

Comparative analysis of mechanical stretch-induced activation activity of back and leg muscle satellite cells in vitro

It has previously been shown that mechanical stretch induces activation of cultured quiescent satellite cells by rapid release of hepatocyte growth factor (HGF) from its extracellular association with satellite cells and its subsequent presentation to the c‐met receptor. The present study provides evidence that the stretch activation activity varies according to the origin of satellite cells from back and leg skeletal muscles in vitro. Satellite cells were isolated from three muscle groups, back (BK), upper hind limb (UL) and lower hind limb (LL) muscles, of adult male rats and stretch activation activities were compared. In response to stretch, lower hind limb satellite cells showed significantly greater response than upper hind limb and back muscles (LL > UL > BK). Immunoblots of stretched culture media revealed a higher HGF‐releasing capacity of lower hind limb satellite cells than back muscle satellite cells. In addition, lower hind limb satellite cells exhibited a greater activation activity in response to exogenous HGF added to culture media than compared to satellite cells from back and upper hind limb (LL > UL > BK). The increased ability to release HGF and the increased cellular responsiveness might account for higher stretch activation activities of lower hind limb satellite cells. Electrophoretic analysis of myosin heavy chain isoforms verified a higher content of slow muscle fibers in lower limb muscles (LL > UL > BK), suggesting a difference in stretch‐induced activation activity between satellite cells associated with fast and slow muscle fibers.     

Mead acid supplementation does not rescue rats from cataract and retinal degeneration induced by N-methyl-N-nitrosourea

Fatty acids and their derivatives play a role in the response to ocular disease. Our current study investigated the effects of dietary mead acid (MA, 5,8,11-eicosatrienoic acid) supplementation on N-methyl-N-nitrosourea (MNU)-induced cataract and retinal degeneration in Sprague-Dawley rats. Experiment 1 was designed to inhibit cataract formation, with the dams fed a 2.4% MA or basal (<0.01% MA) diet during lactational periods. On postnatal day 7, male pups received a single intraperitoneal (ip) injection of 50 mg/kg MNU or vehicle. Lens opacity and morphology were examined 7 and 14 days after the MNU injection. Experiment 2 was designed to inhibit retinal degeneration and was performed with female postweaning rats. In this experiment, dams were fed the 2.4% MA or basal diet during the lactational periods. Thereafter, the female pups were continuously fed the same diets during their postweaning periods. On postnatal day 21 (at weaning), pups received a single ip injection of 50 mg/kg MNU. Retinal morphology was examined 7 days after the MNU injection. In experiment 3, six-week-old female rats were fed the 2.4% MA or basal diet starting at one week before the MNU injection and were then continuously fed the same diets until sacrifice. Rats at 7 weeks of age were given a single ip injection of 40 mg/kg MNU, and the retina was then examined morphologically one week after the MNU injection. In experiment 1, mature cataract was found in all of the MNU-treated groups, with or without MA supplementation. In experiments 2 and 3, atrophy of both the peripheral and central outer retina occurred in all rats exposed to MNU, with or without MA supplementation, respectively. The severities of the cataracts and retinal atrophy in the rats were similar regardless of MA supplementation. Dietary mead acid, which is used as a substitute in essential fatty acid deficiency in the body, does not modify MNU-induced cataract and retinal degeneration in rat models.     

A direct time-resolved fluoroimmunoassay (TR-FIA) for measuring plasma estradiol-17beta concentrations in cattle

A direct Time-Resolved Fluoroimmunoassay (TR-FIA) system for measuring estradiol-17beta (E(2)) in bovine plasma was developed and evaluated. A 100 microl sample of bovine plasma was used for a TR-FIA without prior extraction and purification. The dose-response curves of reference standards ranged from 0.0625 to 10 pg/well. The minimum detectable concentration of this assay system was 0.625 pg/ml, and 19 pg/ml of E(2) caused a 50% reduction of maximum binding. The intra- and inter-assay coefficients of variation were 10.2 and 17.4%, respectively. The plasma E(2) concentrations measured by direct TR-FIA correlated closely with those measured after extraction (r=0.939). The results in the present study indicate that the TR-FIA reagent for E(2), designed for human research can also be utilized, with some modification, for direct assaying in bovine plasma. This assay type seems to fulfill the requirements for safety, sensitivity, specificity, reproducibility and practical convenience.