Evaluation of nitrogen source, phosphorus rate and mixing depth for growth and establishment of Poa pratensis L. on sand-based systems

Nitrogen is a component of the proteins, enzymes, amino acids, and many other biochemicals in plants required to maintain color and density of grasses and for the restoration of healthy conditions following environmental stress. Phosphorus is an important element ofthe phospholipids that help form the plant cell membranes. The suitable formation of these membranes is dependent on a readily available source ofP to the plant. Mobility and availability of nutrients varies with several factors such as application frequency, placement in the soil, and the amount of irrigation or precipitation, especially in sand-based systems. Frequent applications ofN are used to reduce N loss by leaching because N may be easily leached from a sand-based system. Use of slow-release N sources has been promoted as a more efficient N fertilizer strategy. Phosphorus mobility and availability varies with several factors such as application frequency, placement in the soil, and the amount of irrigation or precipitation. The objectives of this study were to compare urea and methylene urea rate at 146 and 293 kg N•ha-1 at four mixing depths (0, 7.6, 15.2, and 22.9 em) in a sand-based system (Chapter. 2) and to evaluate Prate at 146 and 293 kg P•ha-1 at four mixing depths (0, 7.6, 15.2, and 22.9 em) in a sand-based system (Chapter. 3). Grass clipping samples were collected every two weeks, dried, and weighed. Root dry weight and root organic matter weight also were evaluated at the end of the study. Leachate was collected weekly and analyzed for nitrate-nitrogen (N03-N) and P concentrations. Split applications of urea on the surface produced the largest clipping yield and the best NUE for total mass yield, with the lowest N03-N loss due to leaching. Methylene urea at the 22.9 em mixing depth resulted in more grass growth, smaller N03-N losses, and better NUE for total mass than urea placed below the surface. Grass treated with 293 kg P·ha-1 produced 2-30% more Pin the tissue than treatments of 146 kg P·ha-1 , with the exception of the application at the 15.2 em mixing depth. No difference was found between applications made to the surface and those at the 7.6 em mixing depth. Surface application with 146 and 293 kg P·ha- 1 produced 8-10% and 16-20% more P in tissue than subsurface applications, respectively

Integrating Others: A Study of a Border Social System in the Thailand-Burma Borderland

Ph.DDOCTOR OF PHILOSOPH

Antioxidant effect of lidocaine and procaine on reactive oxygen species-induced endothelial dysfunction in the rabbit abdominal aorta

Background: Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in the endothelium. We tested the antioxidant effect of lidocaine and procaine on ROS-induced endothelial damage in the rabbit aorta. Methods: Aortic rings isolated from rabbits were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution bubbled with 5% CO2 and 95% O 2 at 37.5??C. After precontraction with phenylephrine (PE, 10 -6 M), changes in tension were recorded following a cumulative administration of acetylcholine (ACh 3 ?? 10-8 to 10 -6 M). Differences were measured as percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS as generated by electrolysis of the K-H solution. The aortic rings were pretreated with lidocaine or procaine (10-5 M to 3 ?? 10-3 M) to compare their effects, as well as ROS scavengers, catalase, mannitol, sodium salicylate, and deferoxamine, and a catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results: Lidocaine and procaine dose-dependently maintained endothelium-dependent relaxation induced by ACh despite ROS activity (P < 0.05 vs control value). The 3AT pretreated procaine (3 ?? 10-3 M) group decreased more significantly than the un-pretreated procaine group (P < 0.05). Conclusions: These findings suggest that lidocaine and procaine dose-dependently preserve endothelium-dependent vasorelaxation against ROS attack, potentially via hydrogen peroxide scavenging. Copyright ?? Korean Society of Anesthesiologists, 2010

Fractional exhaled nitric oxide measurements in rhinitis and asthma in children.

Exaled nitric oxide (FeNO) is considered a good noninvasive marker to assess airway inflammation in asthma and allergic rhinitis. In asthma, exhaled NO is very useful to verify adherence to therapy, and to predict upcoming asthma exacerbations. It has been also proposed that adjusting anti-inflammatory drugs guided by the monitoring of exhaled NO, could improve overall asthma control. Other studies showed increased FeNO levels in subjects with allergic rhinitis

Insecticidal activities of a Diospyros kaki root-isolated constituent and its derivatives against Nilaparvata lugens and Laodelphax striatellus

a b s t r a c t a r t i c l e i n f o Diospyros kaki root-derived materials were examined for insecticidal properties against Nilaparvata lugens and Laodelphax striatellus. Based on the LD 50 values, the chloroform fraction of D. kaki extracts showed the most activity against N. lugens (3.78 μg/female) and L. striatellus (7.32 μg/female). The active constituent of the chloroform fraction was isolated by various chromatographic methods and was identified as 5-hydroxy-2-methyl-1,4-naphthoquinone by spectroscopic analyses. To establish the structure-activity relationships, the insecticidal effects of 5-hydroxy-2-methyl-1,4-naphthoquinone and its derivatives against N. lugens and L. striatellus were determined using micro-topical application bioassays. On the basis of LD 50 values, 5-hydroxy-1,4-naphthoquinone was the most effective against N. lugens (0.072 μg/female) and L. striatellus (0.183 μg/ female). 2-Bromo-1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, and 5-hydroxy-2-methyl-1,4-naphthoquinone also had potent insecticidal activities against N. lugens and L. striatellus. In contrast, no insecticidal activity was observed with 2-methoxy-1,4-naphthoquinone or 2-methyl-1,4-naphthoquinone. These results indicate that the functional group (bromo-and hydroxyl-) at the C-2 position of the 1,4-naphthoquinone skeleton and the change in position of the hydroxyl group play important roles in insecticidal activity. Therefore, naturally occurring D. kaki root-derived 5-hydroxy-2-methyl-1,4-naphthoquinone and its derivatives may be suitable as insecticides

Aberrant brain stem morphometry associated with sleep disturbance in drug-naïve subjects with Alzheimer’s disease

OBJECTIVE: Among patients with Alzheimer’s disease (AD), sleep disturbances are common and serious noncognitive symptoms. Previous studies of AD patients have identified deformations in the brain stem, which may play an important role in the regulation of sleep. The aim of this study was to further investigate the relationship between sleep disturbances and alterations in brain stem morphology in AD. MATERIALS AND METHODS: In 44 patients with AD and 40 healthy elderly controls, sleep disturbances were measured using the Neuropsychiatry Inventory sleep subscale. We employed magnetic resonance imaging-based automated segmentation tools to examine the relationship between sleep disturbances and changes in brain stem morphology. RESULTS: Analyses of the data from AD subjects revealed significant correlations between the Neuropsychiatry Inventory sleep-subscale scores and structural alterations in the left posterior lateral region of the brain stem, as well as normalized brain stem volumes. In addition, significant group differences in posterior brain stem morphology were observed between the AD group and the control group. CONCLUSION: This study is the first to analyze an association between sleep disturbances and brain stem morphology in AD. In line with previous findings, this study lends support to the possibility that brain stem structural abnormalities might be important neurobiological mechanisms underlying sleep disturbances associated with AD. Further longitudinal research is needed to confirm these findings