Development of a spot plow providing complete inversion for effective weed control

Tillage for the "complete inversion" of soil, that is, overturning soil slices 180° was proposed, a "spot plow" was developed and tested to accomplish the task, and a simulation model was evaluated to demonstrate the efficacy of the plow on weed control. A 360 mm wide spot plow was designed to operate at a speed of 1.9 m s⁻¹ for the spot plowing with the least possible lateral displacement of the soil slice by utilizing the inertia of the soil slice and securely rotating it. In field experiments, complete spot inversion required an operating speed of at least 1.6 m s⁻¹; at lower speeds, a portion of the soil block was left half-inverted and further lowering led to considerable lateral displacement. The displacement in the forward and lateral directions was minimal, implying that spot plowing is suitable for potential application to and verification of the weed population dynamics model in the field. A simple linear matrix model of the population dynamics of annual weeds was proposed, whereby four layers of soil were set to describe tillage and other ecological events. The effect of tillage on weed control was evaluated by the equilibrium reproduction rate allowed to sustain a stable population of weeds. The simulation model showed that alternately changing the depth of spot plowing had a significant effect on controlling weeds of low-survival-rate seeds, even when some incomplete inversion of the soil slice was taken into account.     

Antimicrobial activity of a bovine myeloid antimicrobial peptide (BMAP‐28) against methicillin‐susceptible and methicillin‐resistant Staphylococcus aureus

A bovine myeloid antimicrobial peptide (BMAP‐28) is a member of the cathelicidin family which is included in the innate immune system of mammals. Recently, there have been many studies about antimicrobial peptides. This study aims to clarify whether BMAP‐28 has bactericidal activity against methicillin‐resistant Staphylococcus aureus (MRSA) and compares its activity against methicillin‐susceptible S. aureus (MSSA) and MRSA. We found that the peptide was effective in killing MRSA (minimal inhibitory concentration (MIC) range; 5–20 µg/mL). It was also revealed that MSSA (MIC range; 1.25–20 µg/mL) had two levels of susceptibility to BMAP‐28. We also examined the effect of BMAP‐28 on bacterial shape to visually show its activity. After exposure to the peptide, both MSSA and MRSA cells showed the morphological changes on their surfaces. Our results indicate that BMAP‐28 is a promising candidate for medicine against drug‐resistant bacteria.     

Cytosolic glutamine synthetase is present in the phloem sap of rice (Oryza sativa L.)

The presence of glutamine synthetase (GS) in the rice sieve tube was examined. Proteins in the rice phloem sap from leaf sheaths were separated by sodium dodecylsulfate–polyacrylamide gel electrophoresis, transferred to polyvinylidine difluoride membranes and immunoblotted with anti-GS1 antibody. A cross-reacting band, thought to be GS1, was detected in the phloem sap. Moreover, the phloem sap contained a significant amount of GS transferase activity. Previous studies have shown that the concentrations of substrates and cofactors in the rice phloem sap are sufficient for cytosolic GS reaction. These data suggest that physiologically active GS1 is present in rice phloem sap, which might convert glutamate to glutamine in vivo .     

CHARACTERIZATION OF CANINE FOCAL LIVER LESIONS WITH CONTRAST-ENHANCED ULTRASOUND USING A NOVEL CONTRAST AGENT—SONAZOID

Contrast-enhanced ultrasound using Sonazoid, a novel contrast medium with a liver-specific Kupffer phase, was evaluated in canine focal liver lesions Twenty-five dogs with a liver mass were given intravenous Sonazoid, and the enhancement pattern in the arterial, portal, and parenchymal phase was characterized. An enhancement defect in the lesion in the parenchymal phase was observed in all malignant lesions, whereas only one of nine benign lesions had a filling defect. The diagnostic value of the presence of a filling defect for malignancy was statistically significant (100% sensitivity, 88.9% specificity, 94.1% positive predictive value, 100% negative predictive value), and was equal to that of hypoenhancement in the portal or delayed phase. The defect pattern (clear or irregular defect) was dependent ( P <0.05) on the types of malignancy (i.e., hepatocellular carcinoma and other types of malignancies). In the arterial phase, five of the six hepatocellular carcinomas had hypervascularity, whereas no other lesion was characterized by hypervascularity. In some dogs, additional lesions that could not be observed with conventional B-mode ultrasonography were detected in the parenchymal phase. The enhancement pattern of Sonazoid, especially in the parenchymal phase, has potential as a diagnostic tool for canine focal liver lesions.     

90Sr THERAPY FOR ORAL SQUAMOUS CELL CARCINOMA IN TWO CATS

Two cats with a superficial oral squamous cell carcinoma responded favorably to treatment using a ⁹⁰Sr probe. From one to six fields were applied per tumor, depending on tumor size. The surface dose per treatment ranged from 75 to 150 Gy and the total surface dose ranged from 200 to 500 Gy. Adverse effects were minimal. The cats survived 7 months and 5 years 9 months from the time of diagnosis. These data indicate that with careful patient selection ⁹⁰Sr may be useful for the treatment of feline oral squamous cell carcinoma in some patients.     

Role of prostaglandin in the control of ovulation in the Japaneseeel Anguilla japonica

ABSTRACT:   The in vitro effects of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and prostaglandins (PGE₁, PGE₂, PGF_1α,PGF_2α) on ovulation in the Japanese eel Anguillajaponica were examined. Oocytes with follicle layers at themigratory nucleus stage (approximately 850–900 µmdiameter) were removed using a polyethylene cannula from artificiallymatured fish. At concentrations of 10 and 100 ng/mL,DHP was found to induce both germinal vesicle breakdown and ovulation.The prostaglandins, except for PGE₁, effectively inducedovulation of previously matured oocytes by DHP treatment in vitro .Prostaglandin F_2α was the most effective. Asignificant increase in ovulation rate was observed even at a concentrationof 0.01 µg/mL PGF_2α.Indomethacin blocked the in vitro ovulation induced by DHPand addition of PGF_2α reversed indomethacin-blockedovulation. Actinomycin D and cycloheximide blocked DHP-induced ovulationand PGF_2α reversed the effects of both inhibitors. Theseresults indicate that DHP induces ovulation through endogenous prostaglandinsynthesis in the follicle layers of the Japanese eel.     

Canopy structure and productivity of Festuca avundinacea Schreb. swards during vegetative and reproductive growth

Canopy structure, productivity and their relationships were examined in 2-year-old swards of fourteen tall fescue ( Festuca arundinacea Schreb.) strains during the vegetative and reproductive growth stages. During the vegetative growth stage morphological characters, particularly tiller size, were closely associated with productivity. Swards with large tillers showed an effective distribution of the incoming light energy within the canopy and hence low extinction coefficient ( K ) value and high productivity at complete light interception. On the other hand, although there was no apparent correlation between K and the productivity or the whole crop during the reproductive growth stage, the productivities of the reproductive and vegetative tillers were positively and negatively related to K respectively. Leaf area index of the reproductive tillers and their position in the canopy had marked effects on the distribution of the incoming light energy within the canopy and on the productivity of both types of tillers. The productivity of the vegetative and the reproductive tillers is discussed in terms of the effect of the competition for incoming light energy between both types of tillers.