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[en] The influence of enhanced UV-B radiation (approximating a 15% ozone layer reduction) on competitive interaction between spring wheat (Triticum aestivum) and wild oat (Avena fatua) was examined in the field. The density-dependent mortality of both wheat and wild oat did not exhibit a significant difference between control and UV-B treatment conditions. A relatively high degree of competitive stress enhanced the effects of UV-B stress on biomass reduction. The relative competitive status of wheat in terms of total biomass increased under UV-B enhancement while it decreased when based upon grain production. Shifts in competitive balance occurred with significant changes in total biomass, especially when plants grew at higher densities in monocultures and mixtures. The sensitivity of wild oat to intensification of UV-B radiation at higher densities in mixtures was greater than that at lower densities. At all densities examined, wheat grown in mixture was significantly less sensitive to UV-B radiation than that in monoculture, and just the opposite for wild oat. The density of monocultures did not alter the response index (RI) of wheat and wild oat to enhanced UV-B radiation. (author)
[en] This study investigated the effects of histamine H1 or H2 receptor antagonists on emotional memory consolidation in mice submitted to the elevated plus maze (EPM). The cerebellar vermis of male mice (Swiss albino) was implanted using a cannula guide. Three days after recovery, behavioral tests were performed in the EPM on 2 consecutive days (T1 and T2). Immediately after exposure to the EPM (T1), animals received a microinjection of saline (SAL) or the H1 antagonist chlorpheniramine (CPA; 0.016, 0.052, or 0.16 nmol/0.1 µL) in Experiment 1, and SAL or the H2 antagonist ranitidine (RA; 0.57, 2.85, or 5.7 nmol/0.1 µL) in Experiment 2. Twenty-four hours later, mice were reexposed to the EPM (T2) under the same experimental conditions but they did not receive any injection. Data were analyzed using one-way ANOVA and the Duncan test. In Experiment 1, mice microinjected with SAL and with CPA entered the open arms less often (%OAE) and spent less time in the open arms (%OAT) in T2, and there was no difference among groups. The results of Experiment 2 demonstrated that the values of %OAE and %OAT in T2 were lower compared to T1 for the groups that were microinjected with SAL and 2.85 nmol/0.1 µL RA. However, when animals were microinjected with 5.7 nmol/0.1 µL RA, they did not show a reduction in %OAE and %OAT. These results demonstrate that CPA did not affect behavior at the doses used in this study, while 5.7 nmol/0.1 µL RA induced impairment of memory consolidation in the EPM
[en] Biological spectral weighting functions (BSWF) play a key role in calculating the increase of biologically effective solar ultraviolet-B radiation (UV-BBE) due to ozone reduction, assessing current latitudinal gradients of UV-BBE. and comparing solar UV-BBE with that from lamps and filters in plant experiments. Plant UV action spectra (usually determined with monochromatic radiation in the laboratory with exposure periods on the order of hours) are often used as BSWF. The realism of such spectra for plants growing day after day in polychromatic solar radiation in the field is questionable. We tested the widely used generalized plant action spectrum since preliminary data from an action spectrum being developed with monochromatic radiation for a cultivated oat variety indicate reasonable agreement with the generalized spectrum. These tests involved exposing plants to polychromatic radiation either from a high-pressure xenon arc lamp in growth chambers or in the field under solar radiation with supplemental UV-B lamps. Different broad-spectrum combinations were achieved by truncating the spectrum at successively longer UV wavelengths with various filters. In the growth chamber experiments, the generalized plant spectrum appeared to predict plant growth responses at short (<310nm) wavelengths but not at longer wavelengths. The field experiment reinforced these conclusions, showing (in addition to the expected direct UV-B effects) both direct UV-A effects and UV-A mitigation of UV-B effects. (author)
[en] NARC Oat is high yielding fodder variety developed at Fodder Research Program, National Agricultural Research Centre (NARC), Islamabad, during 2011. It was selected from Canadian material (cv. Scott) and evaluated in different trials for six years (2002-03 to 2007-08) with the name of 'PIN-98'. NARC Oat produced averagely 27 percent more yield of green fodder than check 'S-2000' in preliminary, on-farm/adaptation and at farmers' fields trials. It was evaluated in the National Uniform Fodder Yield Trials (NUFYTs) for three years (2004-05 to 2006-07). It recorded average green-fodder yield of 64.56 t ha/sup -1/ against check variety 'S-2000' that produced 58.16 t ha/sup -1/ having 11% more yield across 33 locations of the country. The new oats variety 'NARC Oat' was approved by the Punjab Seed Council in its meeting held on January 12, 2011. (author)
[en] Neonatal Sprague-Dawley rats were randomly divided into normal control, mild hypoxia-ischemia (HI), and severe HI groups (N = 10 in each group at each time) on postnatal day 7 (P7) to study the effect of mild and severe HI on anxiety-like behavior and the expression of tyrosine hydroxylase (TH) in the substantia nigra (SN). The mild and severe HI groups were exposed to hypoxia (8% O_2/92% N_2) for 90 and 150 min, respectively. The elevated plus-maze (EPM) test was performed to assess anxiety-like behavior by measuring time spent in the open arms (OAT) and OAT%, and immunohistochemistry was used to determine the expression of TH in the SN at P14, P21, and P28. OAT and OAT% in the EPM were significantly increased in both the mild (1.88-, 1.99-, and 2.04-fold, and 1.94-, 1.51-, and 1.46-fold) and severe HI groups (1.69-, 1.68-, and 1.87-fold, and 1.83-, 1.43-, and 1.39-fold, respectively; P < 0.05). The percent of TH-positive cells occupying the SN area was significantly and similarly decreased in both the mild (17.7, 40.2, and 47.2%) and severe HI groups (16.3, 32.2, and 43.8%, respectively; P < 0.05). The decrease in the number of TH-positive cells in the SN and the level of protein expression were closely associated (Pearson correlation analysis: r = 0.991, P = 0.000 in the mild HI group and r = 0.974, P = 0.000 in the severe HI group) with the impaired anxiety-like behaviors. We conclude that neonatal HI results in decreased anxiety-like behavior during the juvenile period of Sprague-Dawley rats, which is associated with the decreased activity of TH in the SN. The impairment of anxiety and the expression of TH are not likely to be dependent on the severity of HI
[en] Research highlights: → MMP-9 plays a pivotal role in the invasion of MCF-7 breast cancer cells. → TPA stimulates MMP-9 expression through activation of MAPK/NF-κB and MAPK/AP-1 pathways. → Dihydroavenanthramide D suppresses MMP-9 expression via inhibition of TPA-induced MAPK/NF-κB and MAPK/AP-1 activations. → Dihydroavenanthramide D blocks cell invasion of MCF-7 breast cancer cells. -- Abstract: Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component of oat. Previous study demonstrates that DHAvD strongly inhibits activation of nuclear factor-kappa B (NF-κB), which is a major component in cancer cell invasion. The present study investigated whether DHAvD can modulate MMP-9 expression and cell invasion in MCF-7 human breast cancer cells. MMP-9 expression and cell invasion in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased, whereas these inductions were muted by DHAvD. DHAvD also suppressed activation of mitogen-activated protein kinase (MAPK), and MAPK-mediated nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activations in TPA-treated MCF-7 cells. The results indicate that DHAvD-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of the MAPK/NF-κB and MAPK/AP-1 pathways in MCF-7 cells. DHAvD may have potential value in breast cancer metastasis.
[en] The effect of twelve weeks of composting on the mobility and bioavailability of cadmium in six composts containing sewage sludge, wood chips and grass was studied, along with the cadmium immobilization capacity of compost. Two different soils were used and Cd accumulation measured in above-ground oat biomass (Avena sativa L.). Increasing pH appears to be an important cause of the observed decreases in available cadmium through the composting process. A pot experiment was performed with two different amounts of compost (9.6 and 28.8 g per kg of soil) added into Fluvisol with total Cd 0.255 mg kg-1, and contaminated Cambisol with total Cd 6.16 mg kg-1. Decrease of extractable Cd (0.01 mol l-1 CaCl2) was found in both soils after compost application. The higher amount of compost immobilized an exchangeable portion of Cd (0.11 mol l-1 CH3COOH extractable) in contaminated Cambisol unlike in light Fluvisol. The addition of a low amount of compost decreased the content of Cd in associated above-ground oat biomass grown in both soils, while a high amount of compost decreased the Cd content in oats only in the Cambisol.
[en] Phototransformation at 20C of the red-absorbing form of phytochrome (Pr) to the far-red-absorbing form (Pfr) was studied with both undegraded oat (Avena sativa L) and undergraded pea (Pisum sativum) phytochrome. Phototransformation was initiated by a 15-ns laser pulse with maximum emission near 600 nm. The first resolvable transformation intermediate exhibited relative to Pr a maximum absorbance increase near 700 nm and was fully present at 60 ns after the flash. This intermediate absorbance decayed by two reactions for oat phytochrome (half-lives of 11 and 140 μs assuming parallel reactions) and by three for pea phytochrome (half-lives of 14,280 and 1600 μs assuming parallel reactions). The appearance of the far-red-absorbing phytochrome, as monitored by absorbance increase at 720 nm, occurred by at least two reactions for both oat (half-lives of 47 and 250 ms assuming parallel reactions) and pea (half-lives of 170 and 770 ms assuming parallel reactions) phytochrome. Assays for possible proteolysis of the phytochrome samples studied indicated that the presence of degraded phytochrome could not account for the observed multiphasic kinetics except possibly for one phase of the triphasic intermediate decay seen with pea phytochrome. (author)
[en] The effects of different doses of sugarcane filter cake (SFC) on iron concentrations in the leaves of varying age of a potential fodder crop oat (Avena sativa L.) are reported in this study. Nine different treatments of SFC used were: 0 (control), 600, 900, 1200 and 1500 kg/ha applied to soil as full doses before sowing, and 600, 900, 1200, and 1500 applied as two equal splits, first before sowing and the second before flower initiation. Samples of soil were taken just after mixing the appropriate dose of SFC, whereas those of leaves were taken at the vegetative stage (45 days after sowing; hereafter they are referred as early leaves) and at the grain filling stage (hereafter referred to as late leaves). Iron (Fe) concentrations in soil and leaf samples (early and late) were determined unconnectedly. Soil Fe content increased significantly due to soil amendment with filter cake and it was well above the known critical level (2.5 mg/kg). In contrast, although soil amended with SFC improved the Fe content of both early and late leaves, their Fe content was well below the normal requirement of grazing animals. Thus, the ruminants feeding on this fodder species growing on soils amended with SFC are prone to experience Fe deficiency. Mineral supplementations containing reasonable amount of Fe sources are recommended to prevent complications caused by Fe deficiency as well as to achieve an optimal animal production of ruminants being reared on the pasture. (author)