Synthesis and insecticidal activity of benzoheterocyclic analogues of N'-benzoyl-N-(tert-butyl)benzohydrazide: Part 3. Modification of N-tert-butylhydrazine moiety

Nineteen analogues were synthesized by modifying the tert-butylhydrazine moieties of N'-tert-butyl-N'-(3,5-dimethylbenzoyl)-5-methyl-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide and N'-tert-butyl-N'-(3,5-dimethylbenzoyl)-5-methylchromane-6-carbohydrazide (chromafenozide), and the synthesized analogues were evaluated for their insecticidal activity against Spodoptera litura F. While all of the synthesized analogues had insecticidal activity inferior to those of the lead compounds, several of the analogues nonetheless showed high insecticidal activity. Chromafenozide has shown very high selectivity toward lepidopteran species.     

Effects of milrinone on hemodynamics and regional blood flow in the hypoxic dog

Milrinone, a therapeutic agent for acute congestive heart failure, has both inotropic and vasodilatory effects, but investigations of these effects of milrinone were almost all conducted under normoxia, and few reports have investigated how milrinone affects the hemodynamics and redistribution of regional blood flow under severe hypoxia. By using colored microspheres, we investigated how milrinone affects hemodynamics and the redistribution of regional blood flow under severe hypoxia. Twelve healthy mongrel dogs were divided into 2 groups. The milrinone group was infused with milrinone cumulatively at 25, 75 and 250 microg/kg for 5 min each. The intact group was infused with saline instead of milrinone. We measured the hemodynamics and cerebrum, cerebellum and kidney blood flow in both groups. Both groups were inspired with 10% oxygen. Milrinone induced significant decrease in mean pulmonary artery and pulmonary vascular resistance, compared with the intact group. In both groups slight decreases in mean arterial pressure, systemic vascular resistance and double-product were seen. In regional blood flow, milrinone-induced increases in blood flow were seen in the cerebrum, cerebellum, and especially in the kidneys. Milrinone's vasodilatory effects were sufficient even under hypoxia. And milrinone increased regional blood flow slightly in the cerebrum and cerebellum, and significantly in the kidneys. These results suggested that milrinone protects against hypoxia-induced organ damage especially in the kidneys. In addition, milrinone is very potent in improving severe congested hemodynamics which complicates hypoxic pulmonary vasoconstriction.     

Effect of intravenous infusion of isotonic sodium bicarbonate solution on acidemic calves with diarrhea

The effect of 1.35% isotonic sodium bicarbonate solution (ISB) administered intravenously on acid-base equilibrium was examined in 18 acidemic Japanese black beef calves with spontaneous diarrhea. The infusion volumes of ISB were decided based on the first half volumes of base needed. In 72.2% (13/18) of calves, improvement of acidemia was detected. There was good correlation (r=0.693, p<0.01) between infused volume of ISB and changes in base excess (y=1.097x + 4.762). Infusion volumes of ISB were 7.5, 10.2, 12.9 and 15.7 ml/kg, respectively, enough to correcting the first half of 5, 10, 15 and 20 mEq/l of base deficit in acidemic calves. Our finding suggested that ISB could be used to correct metabolic acidosis without altering electrolyte concentrations in calves.     

Effects of amino nitrogen on fermentation parameters by mixed ruminal microbes when energy or nitrogen is limited

Ruminal microbes harvested from a ruminally fistulated cow were incubated in simple batch and semicontinuous cultures with NH₃‐N or amino‐N on nitrogen‐ or energy‐excess diets in quantity (HN and LN diets, respectively, consisting of timothy hay plus soybean meal, or corn grain), based on evaluation with the National Research Council and Cornell Net Carbohydrate and Protein System models. In a batch culture experiment, supplementation with amino‐N promoted digestion and fermentation in the course of incubation (4–24 h) on both diets, but these effects mostly disappeared when the diets were sufficiently digested (at 48 h). In a semicontinuous culture experiment using Rusitec, no effect of amino‐N was exhibited after sufficient fermentation and digestion, but significant promotion of digestion was shown in the course of incubation on the HN diet, while no such effect was detected on the LN diet. The microbial yield for 24 h did not show a significant difference between the N sources of either of the two diets. These results suggest that the stimulatory effects of amino‐N are diminished when the diets are sufficiently digested after a long retention and incubation, and also that the effectiveness of amino‐N does not require a quantitatively energy‐excess status.     

Optimal application timing of simeconazole granules for control of rice kernel smut and false smut

We investigated the optimal timing of simeconazole (RS-2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol) application for controlling rice kernel smut in field trials in Miyagi Prefecture, Japan, using formulations of simeconazole (1.5% granules). The field tests revealed that a submerged application of simeconazole granules (450–600 g ai/ha) at 1–5 weeks before heading was highly effective against kernel smut, with treatments 1–2 weeks before heading being the most effective. Submerged application of the fungicide at 2–5 weeks before heading was also highly effective against false smut, with treatment 3 weeks before heading being the most effective. These periods overlap the timing for optimal application of simeconazole to control rice sheath blight and ear blight. Consequently, we concluded that treatment with simeconazole 2–3 weeks before heading can be a useful tool for controlling all four diseases.     

Enhancement of photosynthesis and growth of tomato seedlings by forced ventilation within the canopy

A forced ventilation system that directs airflow upward or downward within a canopy was developed for plant culture in order to enhance photosynthesis and growth of the plant canopy. Tomato seedling canopies including the seedlings, growing medium, and a plastic tray were used for the experiments. In the upward and downward ventilation systems, air flows upward and downward, respectively, within the plant canopy; this is achieved by blowing and drawing air from holes (Ø 6 mm) made in plastic pipes positioned on the surface of the growing medium. A horizontal airflow system was used as a conventional system to compare the performance of the experimental ventilation systems. Using the upward and downward ventilation systems, the effects of air directions and air velocities on the CO₂ exchange rate of the tomato seedling canopy and the growth of the seedlings were compared with those observed using the conventional horizontal airflow system. The forced ventilation within the plant canopy enhanced the CO₂ exchange rate of the canopy and the dry masses of the seedlings by 1.4–1.5 and 1.2–1.3 times, respectively, as compared to the conventional horizontal airflow. When the leaf area index (LAI) increased from 1.2 to 2.4, there was only a 5% decrease in the CO₂ exchange rate per unit leaf area in the downward ventilation system, whereas there was a 20% decrease in the CO₂ exchange rate per leaf area in the horizontal airflow system. The coefficient of variation for the dry mass of the seedlings was higher in the downward system than in the other systems. These results demonstrate that forced ventilation within the canopy is an effective technique to enhance the gas exchange of the plant canopy and the consequent plant growth.     

Production of inter-section hybrids between Primula filchnerae and P. sinensis through ovule culture

Inter-section hybrids were obtained in the reciprocal crosses between Primula filchnerae (2n = 2x = 24) of Sect. Pinnatae and P. sinensis ‘Fanfare’ (2n = 2x = 24) of Sect. Auganthus by rescuing ovules on half-strength (1/2) Murashige and Skoog's (MS) medium supplemented with 50 g l⁻¹ sucrose, 2.5 g l⁻¹ gellan gum, 0.1 mg l⁻¹ α-naphthaleneacetic acid (NAA), 0.1 mg l⁻¹ 6-benzyladenine (BA) and 50 mg l⁻¹ gibberellic acid (GA₃). In ovule culture, germination occurred with radicle elongation but no plumule was observed. The radicle kept on the initial medium showed root proliferation with callus formation. When the calluses were transferred to (1/2)MS media containing 30 g l⁻¹ sucrose and 3 g l⁻¹ gellan gum, without plant growth regulators (PGRs) or with 1 mg l⁻¹ zeatin and 0.1 mg l⁻¹ NAA, plantlets were regenerated. The plants thus obtained were confirmed to be hybrids through flow cytometry (FCM) and random amplified polymorphic DNA (RAPD) analyses. The hybrid obtained when P. filchnerae was used as the maternal parent was diploid, whereas hexaploid hybrid was obtained when using P. sinensis as the maternal parent. The hexaploid hybrid might be produced through chromosome doubling of a triploid originated from the fertilization of P. sinensis with unreduced pollen of P. filchnerae.     

Experimental infections of a ciliate Tetrahymena pyriformis on ornamental fishes

SUMMARY: Experimental infection of Tetrahymena pyriformis was conducted on ornamental fishes with skin wounded by acetic acid treatment. Among fishes used in this experimental infection, guppy Poecilia reticulata , pristella Pristella maxillaris , neontetra Paracheirodon innesi and cherry barbs Puntius titteya proved to be sensitive to challenge, while medaka Oryzias latipes , dwarf gourami Colisa lalia , goldfish Carassius auratus , platy Xiphophorus maculatus and angelfish Pterophyllum scalare were resistant. In catfish Corydoras aeneus infection was unsuccessful. Exposure to Tetrahymena at ≥100 cells/mL at 25 to 30°C and at pH of 6.0 to 8.0 resulted in the successful infection of some sensitive fish species. Histological and bacteriological observations suggest that deeply destroyed skin tissues from the acid-treated method are the primary factors in successful infection.     

Larger body size with higher predation rate

Abstract –  Many studies have reported that prey fish increase in body size with an increase in piscivore abundance, and this change may be explained mainly by two processes: release from intraspecific competition because of a reduction in the prey fish population and size-dependent selection by the piscivore. However, the evolutionary mechanism is not yet fully understood. Here, we first show the body-size dynamics of the semelparous gobiid fish Gymnogobius isaza , which is one of the prey fishes of the introduced largemouth bass, Micropterus salmoides . The data show the possibility that the goby body size might have changed in parallel to the number of largemouth bass from 1975 to 2002, which may be one of the best examples of the positive relationship between body size and predation rate. Furthermore, we explored a mathematical model to consider a body-size change of semelparous fish from an evolutionary viewpoint. The model provided the following qualitative predictions: (1) the optimal assimilation rate increases with predation pressure; (2) a rapid large-scale increase in predation pressure may exterminate the prey fish because of delayed evolution of the assimilation rate; and (3) the optimal assimilation rate increases when the prey fish is more likely to die through predation than through natural mortality or when it is difficult to grow larger because of low resource availability or insufficient foraging efficiency. Moreover, we propose a theoretical framework to evaluate the relative effects of ecological and evolutionary processes over the long term.