1,251 research outputs found
Research notes: Effects of light on soybean leaf chlorophyll content-- The role of the Y11 gene
Previous studies on the genetics of chlorophyll production have revealed the involvement of a gene Y11 , which is incompletely dominant. Thus, three phenotypes may be observed -- plants with leaves that are normally pigmented, light-green or yellow. The yellow is a lethal in nature; however, we have propagated them under laboratory conditions either by grafting the yellows to wild-type plants or growing them independently under constant low-level illumination with a short period of moderate (400 ft-c) illumination each day
Research notes: Photosynthetic activity in chlorophyll deficient soybean leaves carrying the Y11 mutant
In soybeans, the Y11 gene is involved in chlorophyll synthesis. Thus, in the.heterozygous condition Y11y11 , an intermediate or light-green leaf pigmentation results. Photosynthetic C02 assimilation in the light-green, on a surface area basis, has been reported to be as high or nearly as high as in the homozygous dominant, dark-green plant (Wolf, 1965; Keck et al., 1974; Cappy and Noble, 1974; Crang and Noble, 1978)
High temperature mobility of CdTe
The Hall mobility of electrons μH is measured in CdTe in the temperature interval 450-1050°C and defined Cd overpressure in near-intrinsic conditions. The strong decrease of μH above 600°C is reported. The effect is explained within a model of multivalley conduction where both electrons in �1c minimum and in L1c minima participate. The theoretical description is based on the solution of the Boltzmann transport equation within the relaxation time approximation including the polar and acoustic phonon intravalley and intervalley scatterings. The �1c to L1c separation �E=0.29 - 10-4T (eV) for the effective mass in the L valley mL=0.35m0 is found to best fit the experimental data. Such �E is about four times smaller than it is predicted by first-principle calculations. © 2001 American Institute of Physics
Analisis Nilai Ekonomi Museum T.B Silalahi Center di Kecamatan Balige, Kabupaten Toba Samosir dengan Menggunakan Pendekatan Metode Biaya Perjalanan
This research was carried out on the object Tourism of TB Silalahi Museum Centre in Toba Samosir regency of North Sumatra to determine the economic value of the environment and to look the influence of travel costs, income, and residence distance of respondents with the number of visitor who come to the TB Silalahi museum center. This research took a sample of 100 respondents of TB Silalahi Museum Center visitor. Data analysis methods that I used in this research were descriptive and quantitative methods. Quantitative analysis was performed by using multiple linear regression equation to the data collected in the form of numbers in tabulated form then discussed it with descriptive methods. In calculations, the economic value of TB Silalahi museum Center that based of approach travel cost is Rp 2,735,078,350. From the analysis, the rate coefficients of the variables that affect the number of visitor to the museum TB Silalahi Center are travel costs (X1) 0.0000142, income (X2) 0.00005032, and distance of residence of respondents to the tourist attractions (X3) -0.122. The results of testing research can also be known simultaneously (synchronously) showed significant effect in which the travel expenses, income and distance of the respondents. Travel expenses, income and distance respondents have significantly influence the number of museum TB Silalahi Center visitor. It is shown from the test results calculated that F (58,992)> F table (2.70). The partial test results showed only the income variable does not have significantly influence to the number of individual visitor who come to the TB Silalahi Museum Center.Keywords: TB Silalahi Museum Centre, Travel Cost Methode and Economic Valu
ChIPOTle: a user-friendly tool for the analysis of ChIP-chip data
ChIPOTle (Chromatin ImmunoPrecipitation On Tiled arrays) takes advantage of two unique properties of ChIP-chip data: the single-tailed nature of the data, caused by specific enrichment but not specific depletion of genomic fragments; and the predictable enrichment of DNA fragments adjacent to sites of direct protein-DNA interaction. Implemented as a Microsoft Excel macro written in Visual Basic, ChIPOTle uses a sliding window approach that yields improvements in the identification of bona fide sites of protein-DNA interaction
Detection of a Substantial Molecular Gas Reservoir in a brightest cluster galaxy at z = 1.7
We report the detection of CO(2-1) emission coincident with the brightest
cluster galaxy (BCG) of the high-redshift galaxy cluster SpARCS1049+56, with
the Redshift Search Receiver (RSR) on the Large Millimetre Telescope (LMT). We
confirm a spectroscopic redshift for the gas of z = 1.7091+/-0.0004, which is
consistent with the systemic redshift of the cluster galaxies of z = 1.709. The
line is well-fit by a single component Gaussian with a RSR resolution-corrected
FWHM of 569+/-63 km/s. We see no evidence for multiple velocity components in
the gas, as might be expected from the multiple image components seen in
near-infrared imaging with the Hubble Space Telescope. We measure the
integrated flux of the line to be 3.6+/-0.3 Jy km/s and, using alpha_CO = 0.8
Msun (K km s^-1 pc^2)^-1 we estimate a total molecular gas mass of
1.1+/-0.1x10^11 Msun and a M_H2/M_star ~ 0.4. This is the largest gas reservoir
detected in a BCG above z > 1 to date. Given the infrared-estimated star
formation rate of 860+/-130 Msun/yr, this corresponds to a gas depletion
timescale of ~0.1Gyr. We discuss several possible mechanisms for depositing
such a large gas reservoir to the cluster center -- e.g., a cooling flow, a
major galaxy-galaxy merger or the stripping of gas from several galaxies -- but
conclude that these LMT data are not sufficient to differentiate between them.Comment: accepted for publication in ApJ Letter
Derivation of a dynamic model of the kinetics of nitrogen uptake throughout the growth of lettuce : calibration and validation
A kinetic model of nitrogen (N) uptake throughout growth was developed for lettuce
cultivated in nutrient solution under varying natural light conditions. The model couples
nitrogen uptake with dry matter accumulation using a two-compartment mechanistic
approach, incorporating structural and non-structural pools. Maximum nitrogen uptake
rates are assumed to decline with shoot dry weight, to allow for the effects of plant
age. The model was parameterized using data from the literature, and calibrated for
differences in light intensity using an optimization algorithm utilizing data from three
experiments in different growing seasons. The calibrated model was validated against
the data from two independent experiments conducted under different light conditions.
Results showed that the model made good predictions of nitrogen uptake by plants from
seedlings to maturity under fluctuating light levels in a glasshouse. Plants grown at a
higher light intensity showed larger maximum nitrogen uptake rates, but the effect of
light intensity declined towards plant maturity
Lack of prophylaxis before the onset of acute venous thromboembolism among hospitalized cancer patients: the SWIss Venous ThromboEmbolism Registry (SWIVTER)
Background: Venous thromboembolism (VTE) prophylaxis remains underutilized, particularly in cancer patients. We explored clinical predictors of prophylaxis in hospitalized cancer patients before the onset of acute VTE. Methods: In the SWiss Venous ThromboEmbolism Registry, 257 cancer patients (61 ± 15 years) with acute VTE and prior hospitalization for acute medical illness or surgery within 30 days (91% were at high risk with Geneva VTE risk score ≥3) were enrolled. Results: Overall, 153 (60%) patients received prophylaxis (49% pharmacological and 21% mechanical) before the onset of acute VTE. Outpatient status at the time of VTE diagnosis [odds ratio (OR) 0.31, 95% confidence interval (CI) 0.18-0.53], ongoing chemotherapy (OR 0.51, 95% CI 0.31-0.85), and recent chemotherapy (OR 0.53, 95% CI 0.32-0.88) were univariately associated with the absence of VTE prophylaxis. In multivariate analysis, intensive care unit admission within 30 days (OR 7.02, 95% CI 2.38-20.64), prior deep vein thrombosis (OR 3.48, 95% CI 2.14-5.64), surgery within 30 days (OR 2.43, 95% CI 1.19-4.99), bed rest >3 days (OR 2.02, 95% CI 1.08-3.78), and outpatient status (OR 0.38, 95% CI 0.19-0.76) remained the only independent predictors of thromboprophylaxis. Conclusions: Although most hospitalized cancer patients were at high risk, 40% did not receive any prophylaxis before the onset of acute VTE. There is a need to improve thromboprophylaxis in cancer patients, particularly in the presence of recent or ongoing chemotherap
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