1,590 research outputs found

    Hydrothermal Variations and Physio-Osmotic Conditioning E.ects on Five African Millet Varieties during Short Term Substrate Desiccation

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    Environmental factors di.erentially a.ect the germination of millet (Pennisetum americanum L.) and impact both the rate and extent of .eld emergence. The extent and uniformity of emergence depends on hydrothermal variations in both soil moisture and temperature levels. To determine the impact of these two factors and counteracting physiological and osmotic conditioning seed treatments, two growth chamber trials were conducted on African millet. Five genotypes responded to di.erences in temperature or osmotic seed conditioning. Seed conditioning with GA3, Kinetin, NaCl and KNO3 was tested. Increasing incubation temperature decreased the final proportion of seeds germinating and slowed germination for each of the five genotypes tested when exceeding a 29°C threshold. GA3 improved the performance of seed lots, while physio-osmotic conditioning and temperature interacted to affect the proportion of germinating millet seeds. These germination tests partially explain interspecific differences in the impact of timing of heat fluctuations in the field. Patterns of millet germination in response to temperature and rainfall fluctuations could be explained by its response to seed conditioning, temperature or moisture levels

    Time-Course Changes in High Temperature Stress and Water Deficit During the First Three Days After Sowing in Hydro-Primed Seed: Germinative Behaviour in Sorghum

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    Both drought and heat stresses substantially influence the germination pattern and subsequent establishment rates of sorghum. The timing of high temperature occuarrance, along with water deficit after seed sowing is investigated and methods for its alleviateion are evaluated. Two experiments were conducted on CSV 15 sorghum seeds after soaking treatments in 2, 4 or 6g NaCl l−1 solutions. Several high temperature stress scenarios of 45◦C were administered at various times during the second day after sowing, or at a fixed time during the first, second or third days after sowing. Results revealed that the 18th hour of the second day after sowing is more sensitive, in terms of the final germination percentage and germination index attained, than the 6th, 12th or 24th hour. Seed treatment with 2g NaCl l−1 was superior to untreated seeds in its response to high temperature stress, attaning more positive germinative characteristics. Heat shock on the first day after sowing had more negative impacts on germination than on the second or third days. It also caused an increase in radicle growth at the expense of plumule growth, thus decreasing the plumule:radicle ratio

    Influence of various composted organic amendments and their rates of application on nitrogen mineralization and soil productivity using chinese cabbage (Brassica rapa L. var. Chinensis) as an indicator crop

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    There is a diversity of locally available nitrogen (N)-rich organic materials in Samoa. However, none of them was evaluated for their N supplying capacity after composting in Samoan Inceptisols for vegetable cultivation. Thus, N-releasing capacity of five composted organic amendments (OAs) namely macuna, gliricidia, erythrina, lawn grass and giant taro, and their two application rates (10 and 20 t ha−1) were assessed through a laboratory incubation and a crop response study using Chinese cabbage as a test crop. Among the OAs, composted mucuna was characterized by a higher total N (2.91%), organic C (63.6%) and NO3−N content (341 mg N kg−1). A significant difference in N mineralization was observed among the OAs as well as application rates. The highest N mineralization was recorded in composted mucuna followed by gliricidia, erythrina, lawn grass, and giant taro. A crop response study also showed a similar trend. Mucuna treatment had the highest biomass yield and N uptake followed by gliricidia, erythrina, lawn grass, and giant taro. Leguminous composted OAs @ 20 t ha−1 performed substantially better in all the plant growth and yield parameters, and N uptake compared to 10 t ha−1 that was not the case for non-leguminous OAs. Thus, non-leguminous OAs should be applied at 10 t ha−1. All the composted leguminous OAs showed promising results while mucuna was the best in both the application rates. Therefore, mucuna can be promoted to supply N for crop cultivation in Samoa, other Pacific Islands and tropical countries where N fertilizer is costly and not easily available

    Comparison of two digital intraoral radiography imaging systems as a function of contrast resolution and exposure time

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    BACKGROUND To compare the image quality of two different digital imaging systems; one photostimulable phosphor plate system (PSP) and a direct digital radiography system with CMOS imaging sensor; via evaluating contrast resolution among four different exposure times. METHODS Endodontically treated incisor teeth embedded in paraffin blocks are aligned next to a 99.5% Al wedge and exposed for 0.8, 0.1,0.125 and 0.16 seconds using both the CMOS and PSP systems. Using ImageJ software, 5 isometric and isogridded ROI from each root filling area and isometric ROI from the Al stepwedge were calculated. RESULTS Evaluation of the total of 120 images displayed that PSP system produced significantly higher contrast resolution (P0.05). CONCLUSIONS The contrast resolution was higher using the PSP system. It can be estimated that, filling material will be more obvious under lower doses using PSP

    EFEKTIVITAS KINERJA PEGAWAI SEKRETARIAT KOMISI PEMILIHAN UMUM (KPU) KOTA BENGKULU DALAM PENYELENGGARAAN PEMILIHAN KEPALA DAERAH KOTA BENGKULU TAHUN 2018

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    This study aims to determine the Effectiveness of the Performance of secretariat commission for general election (KPU) Bengkulu City on the organization of the Election of Regional Heads (PILKADA) of Bengkulu City in 2018. The Data were collected by using in-depth interviews, observation and documentation. The obtained data were analyzed by means of data reduction, data presentation and conclusion. This is a qualitative-descriptive study which takes two groups as the informants.The informants are categorized as key informant and principal informants. Key informant in this study was the secretary of KPU Bengkulu City while the principal informants were the secretariat staff of KPU Bengkulu City. The researcher chose the secretary of KPU as the key informant because he knew and mastered the information needed by the researcher. Meanwhile, the secretariat staff of KPU Bengkulu City were selected as the principle informants because they can provide information about organizing the election. The result shows that the performance of the employees of the Secretariat of the General Election Commission (KPU) of Bengkulu City was quite effective in completing the Election of Regional Heads (PILKADA) in 2018.The election run successfully and on time as it is expected

    Day-case surgery for total hip and knee replacement: how safe and effective is it?

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    Multimodal protocols for pain control, blood loss management and thromboprophylaxis have been shown to benefit patients by being more effective and as safe (fewer iatrogenic complications) as conventional protocols. Proper patient selection and education, multimodal protocols and a well-defined clinical pathway are all key for successful day-case arthroplasty. By potentially being more effective, cheaper than and as safe as inpatient arthroplasty, day-case arthroplasty might be beneficial for patients and healthcare systems

    Experimental and Theoretical Studies on the Pharmacodynamics of Cisplatin in Jurkat Cells

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    For Jurkat cells in culture exposed to cisplatin (1), we measured the number of platinum adducts on DNA and showed that it is proportional to the AUC, the area under the concentration vs time curve, for cisplatin. The number of platinum-DNA adducts is measured immediately following exposure to drug. The AUC is calculated either as the product of the initial cisplatin concentration and the exposure time or as the integral under the concentration vs time curve for the unreacted dichloro species, which decreases exponentially. We also show that the number of adducts correlates with decreases in respiration, with the amount of DNA fragmentation, and with cell viability, all measured 24 h after exposure to the drug. To study the reactions of cisplatin at concentrations approaching clinical relevance (65 microM), we use two-dimensional [1H15N]HSQC NMR and the 15N-labeled form of the drug, cis-Pt(15NH3)2Cl2, 1. In the absence of cells, 1 reacts with components of the growth medium and also transforms slowly (k(h) = 0.205 h-1 at 37 degrees C) into the chloro-aquo species, cis-[Pt(15NH3)2Cl(H2O)]+ (2), which at the pH of the medium (pH 7.15), is mainly in the deprotonated chloro-hydroxy form, cis-Pt(15NH3)2Cl(OH) (4). The concentration of 2 (4), as measured by HSQC NMR, decreases due to reaction with components of the medium. In the presence of 5 million or more cells, the concentration of 1 decreases with time, but the NMR signal for 2 (4) is not seen because it is rapidly removed from solution by the cells, keeping its concentration very low. These experiments confirm that the species preferentially removed from the medium by cells is 2 (4) and not 1. Our findings are discussed in the context of a kinetic model for platination of nuclear DNA by cisplatin, which includes aquation of cisplatin outside the cell, passage of 2 (4) through the cell membrane, reaction of reactive platinum species (RPS) in the cytosol with thiols, formation of adducts between RPS and accessible sites on genomic DNA, and removal of platinum from DNA by repair. Some of the rate constants involved are measured, but others can only be estimated. Calculations with this model show that little of the platinum reacts with intracellular thiols before reaching the nuclear DNA, indicating that binding to thiols is not important in cisplatin resistance. The model also predicts the circumstances under which the amount of platination of nuclear DNA is proportional to AUC

    Effects of Cisplatin on Mitochondrial Function in Jurkat Cells

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    In this work, we measured the effects of pharmacological concentrations of cisplatin (cis-diaminedichloroplatinum II) on mitochondrial function, cell viability, and DNA fragmentation in Jurkat cells. The exposure of cells to 0-25 microM cisplatin for 3 h had no immediate effect on cellular mitochondrial oxygen consumption, measured using a palladium-porphyrin oxygen sensing phosphor. Similarly, the cell viability as measured by trypan blue staining was unchanged immediately following exposure to the drug, and no small DNA fragments, characteristic of drug-induced apoptosis, appeared. At 24 h after exposure to cisplatin, cellular respiration and viability decreased relative to controls and the amount of small DNA fragments, measured using quantitative agarose gel electrophoresis, was proportional to the concentration of cisplatin present during the drug exposure period. The small DNA fragments showed the banding pattern (with a spacing of approximately 300 bp) characteristic of drug-induced cell death by apoptosis. The changes in respiration and DNA fragmentation correlated linearly with the amount of platinum bound to DNA, determined by atomic absorption spectroscopy immediately following drug exposure. The oxygen consumption by beef heart mitochondria was not affected 0-24 h after exposure to 25 microM cisplatin or to solutions containing the monoaquated form of the drug, suggesting that the drug does not attack the mitochondrial respiratory chain directly. Cells exposed to the peptide benzyloxycarbonyl-val-ala-asp-fluoromethyl ketone, which blocks apoptosis by the caspase pathway, showed a decrease in cisplatin-induced DNA fragmentation but not in the impairment of cellular respiration. Thus, although apoptosis is caspase-dependent, the impairment of cellular respiration is independent of the caspase system. Collectively, these results suggest that alteration in mitochondrial function is a secondary effect of cisplatin cytotoxicity in Jurkat cells

    Engineering squeezed states in high-Q cavities

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    While it has been possible to build fields in high-Q cavities with a high degree of squeezing for some years, the engineering of arbitrary squeezed states in these cavities has only recently been addressed [Phys. Rev. A 68, 061801(R) (2003)]. The present work examines the question of how to squeeze any given cavity-field state and, particularly, how to generate the squeezed displaced number state and the squeezed macroscopic quantum superposition in a high-Q cavity
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