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61.
Summary The risk for a gene dispersal is reported for reciprocal crosses between a transgenic rapeseed variety resistant to the herbicide phosphinotricin and five related species. The first stages after pollination were cytologically observed and fertilized ovaries were established in in vitro culture for the production of interspecific hybrids. A similar classification was observed for the index of pollination compatibility and embryo yield. From the 243 embryos produced, 109 plantlets were obtained in a greenhouse. All the interspecific combinations tested were able to produce hybrid plants. A higher number of hybrids was obtained when rapeseed was used as the female parent. The hybrids had the expected triploid structure except for two amphidiploid, B. napus × B. oleracea, and one amphidiploid, B. napus × S. arvensis, plants with 56 chromosomes. The triploid hybrids were sterile or partially fertile but two of the amphidiploid plants, B. napus × B. oleracea, were fully fertile. The cytoplasm source did not seem to affect the fertility of the hybrids.  相似文献   
62.
63.
Precision irrigation systems can have inherent errors that affect the accuracy of variable water application rates controllers, as well as affect the controllers’ performance when evaluated on different continuous move irrigation systems configurations. The objective of this study was to assess the performance of a remote irrigation monitoring and control system (RIMCS) installed on two separate linear move (LM) irrigation systems. The RIMCS varies water application rates by pulsing nozzles controlled by solenoids connected via relays to a single board computer (SBC) with wireless Ethernet connection to a remote server. The system also monitors irrigation system flow, pressure, position and wireless field sensor networks. The system was installed on a LM irrigation system in Prosser, Washington, USA and on a LM in the Nesson Valley of North Dakota, USA. For the LM at Prosser, four pre-defined irrigation patterns were imposed and variable rates were applied as a percentage of the nozzle base application rate. Each nozzle was pulsed across the span length and along the LM travel direction. For the LM at the Nesson Valley, a quadratic pattern was imposed pulsing banks of nozzles along the LM travel direction. Standard catch can tests were performed and the system performance was evaluated by comparing measured catch can water depths with pre-determined target values. The RIMCS accuracy was found to be in the range of the LM uniform water depth application uniformity coefficients of 88–96%. The RIMCS was successfully transferred to another LM in North Dakota as indicated by the relatively low variable rate application errors of –8.8 ± 8.1% and −0.14 ± 6.7% for the two spans.  相似文献   
64.
We measure the impact that sanitary treatments that control ectoparasite Caligus rogercresseyi abundance have on unit production costs of Salmo salar farms in Chile. We follow complete production cycles for a sample of farms between 2009 and 2015. We estimate a simultaneous salmon biomass growth and Caligus abundance model. The statistical analysis determines the effect of antiparasitic treatments, location of farms, environmental conditions and Caligus abundance on the salmon growth profile. Using outside cost information, we simulate how unit production costs vary by treatment and farm characteristics. Our results suggest that unit production costs increase on average by $1.4?US/kg with Caligus and treatments. Treatment costs are compensated by higher harvesting levels, and unit production costs are invariant to the situation without treatment. All estimated effects differ depending on farm’s environmental and spatial conditions, suggesting that the design of cost-effective intervention calls for discriminatory regulation under heterogeneous conditions.  相似文献   
65.
Extract

In Dunedin, feline respiratory infections with a high morbidity, but a low mortality except in very young animals, commonly occur in epizootics and appear to be enzootic between these outbreaks. The affected animals develop a serous ocular discharge which later becomes mucoid, and a mucoid nasal discharge associated with sneezing especially after handling. While these signs of infection are present, the animals are anorexic and listless. The disease may last for two weeks or more and sometimes affected cats develop a chronic snuffle lasting for months despite treatment. The disease is usually referred to as “snuffles”, although it is probably identical with the syndrome called “rhinotracheitis”. In the summer time, it commonly occurs in boarding establishments where large numbers of pets collected from a wide area are left by summer vacationers. In breeding catteries, infections occur most often in the spring and especially at the time of the first warm weather. Young kittens about 5 to 10 days old are usually affected but kittens which escape infection at this stage not infrequently develop symptoms at about 6 weeks of age.  相似文献   
66.
Feed intake and diet composition appear to affect the body temperature of pigs. Two trials were conducted to analyse the effect of feed intake level and dietary protein content on the intestinal temperature (IT) of pigs housed under thermo neutral conditions. Ten pigs (64.1 ± 1.3 kg initial body weight) fitted with an ileal cannula were used. A thermometer set to register the IT at 5‐min intervals was implanted into the ileum through the cannula. In both trials, the ambient temperature ranged from 19.1 to 21.6°C and the pigs were fed at 07:00 and 19:00 hr (same amount each time). In trial 1, the pigs were fed daily 1.2 or 1.8 kg of a wheat–soybean meal diet. The IT followed a similar pattern along a 24‐hr period regardless the feed intake level. The IT rapidly increased up to 0.61 and 0.74°C after the morning meal and up to 0.53 and 0.47°C after the evening meal in pigs fed 1.2 and 1.8 kg/d respectively. The postprandial IT was higher in pigs fed 1.8 kg after each meal (p < .05). In trial 2, pigs were fed daily 1.8 kg of a low (11%) or a high (22%) crude protein diet. The IT followed a similar pattern along the 24‐hr period regardless the dietary protein level. The postprandial IT did not differ between pigs fed the low protein or the high protein (p > .10). The IT rapidly increased up to 0.66 and 0.62°C after the morning meal in pigs fed the high‐ and low‐protein diet (p < .05), but there was no change after the evening meal (p > .10). In conclusion, the feed intake level affected the IT of pigs housed under TN conditions, but the dietary protein content had no effect.  相似文献   
67.
The effect of Chenopodium quinoa seeds on lipid profile, glucose level, protein metabolism and selected essential elements (Na, K, Ca, Mg) level was determined in high—fructose fed male Wistar rats. Fructose decreased significantly LDL [42%, p < 0.01] and activity of alkaline phosphatase [20%, p < 0.05], and increased triglycerides level [86%, p < 0.01]. The analysis of blood of rats fed quinoa indicated, that these seeds effectively reduced serum total cholesterol [26%, p < 0.05], LDL [57%, p < 0.008] and triglycerides [11%, p < 0.05] when compared to the control group. Quinoa seeds also significantly reduced the level of glucose [10%, p < 0.01] and plasma total protein level [16%, p < 0.001]. Fructose significantly decreased HDL [15%, p < 0.05] level in control group but when the quinoa seeds were added into the diet the decrease of HDL level was inhibited. Quinoa seeds did not prevent any adverse effect of increasing triglyceride level caused by fructose. It was shown in this study that quinoa seeds can reduce most of the adverse effects exerted by fructose on lipid profile and glucose level.  相似文献   
68.
Toxic effects of aluminium (Al) on root tips are considered to decrease export of cytokinins to shoots, and deficiency of cytokinins has been made responsible for Al‐induced inhibition of shoot growth. But no experimental data on the influence of Al on endogenous cytokinin levels in higher plants have been reported. In this study, the endogenous levels of zeatin riboside (ZR) and dihydrozeatin riboside (DHZR) of roots, stems, and leaves of two bean cultivars (Phaseolus vulgaris L. cv Contender and cv Strike) exposed to Al in continuously flowing nutrient solution (pH 4.5) was analysed. The supply of a high Al concentration (sum of monomeric Al species, 127 μM) caused severe inhibition of root elongation in both cultivars. The cv Strike was more affected by both Al‐induced mineral nutrient disorders and Al‐induced alteration of leaf water relationships. In both cultivars Al‐supply significantly increased ZR and DHZR. Leaves of Al‐treated plants exhibited a more than three times higher concentration of ribosylated cytokinins than controls. Nevertheless, stomatal resistance was significantly increased by Al in both cultivars. Our results support the hypothesis that Al affects plants not by inducing deficiency of cytokinins but of some other factor necessary for the manifestation of cytokinin action.  相似文献   
69.
Magnetism has been predicted to occur in systems in which dipolar interactions dominate exchange. We present neutron scattering, specific heat, and magnetic susceptibility data for LiErF(4), establishing it as a model dipolar-coupled antiferromagnet with planar spin-anisotropy and a quantum phase transition in applied field H(c|| = 4.0 ± 0.1 kilo-oersteds. We discovered non-mean-field critical scaling for the classical phase transition at the antiferromagnetic transition temperature that is consistent with the two-dimensional XY/h(4) universality class; in accord with this, the quantum phase transition at H(c) exhibits three-dimensional classical behavior. The effective dimensional reduction may be a consequence of the intrinsic frustrated nature of the dipolar interaction, which strengthens the role of fluctuations.  相似文献   
70.
Strategies for reducing plasma cholesterol have been focused on reducing the absorption or synthesis of cholesterol. The aim of this study was to correlate the content of flavonoids and saponins in black bean (Phaseolus vulgaris L.) seed coats extracts with a potential effect in lowering cholesterol absorption by the inhibition of cholesterol micellar solubility. Extracts with different flavonoids and saponins concentration were obtained from a Box-Behnken design used to optimize extraction temperature, stirring time and solvent composition. Major flavonoids and saponins were quantified by HPLC-PDA-ELSD and confirmed through mass spectrometry. Contrary to the flavonoid content, saponins were correlated to the inhibitory effect of cholesterol micelle solubility as an approach to a potential reduction of cholesterol absorption. Extracts with the highest saponin content strongly inhibited cholesterol micellization with values of 55.4?±?1.9 %, while stigmasterol used as control, only reached 12?±?2.3 % at the same concentration (5 mg/ml). The optimal extracting conditions for saponins were 25 °C, during 3 h in 85 % aqueous-methanol. Correlations of inhibitory effect of cholesterol micellar solubility with the content of each identified saponin suggested that the reduction of cholesterol micellization depends on the C-22 substitution of saponins.  相似文献   
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