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1.
Non-selected and Na2SO-, K2SO4- or KCl-selected callus culturesof Vaccinium corymbosum L. cv. Blue Crop were grown on mediasupplemented with 0, 25 and 50 mM Na2SO4 (non-selected and Na2SO(-selectedonly), 0, 25 and 50mMK2SO4 (non-selected and K2SO4-selectedonly) or 0, 50 and 100 mM KCl (non-selected and KCl-selectedonly). On all media, growth of selected callus (on a fresh-weightor dry-weight basis) was greater than that of non-selected callus,and selected callus grew optimally on the level and type ofsalt on which it was selected. Selected callus was friable andmaintained a higher f. wt:d. wt ratio. Tissue water potentialin selected callus was more negative than in non-selected callus. Flame photometry and chloridometry showed Na+, K+ and Claccumulated in callus to concentrations equal to or greaterthan the initial concentration in the medium. Turbidometry showedthat tissue SO42- concentration was lower than the concentrationin the medium. In most cases selected callus accumulated moreNa+, Ksup, SO42– or Cl than non-selected callus.Vacuolar ion concentration was measured by electronprobe X-raymicroanalysis, and on most media selected callus had highervacuolar ion concentrations than non-selected callus. SO42–and Cl were accumulated in the vacuoles at concentrationshigher than the external medium, but vacuolar Na+ concentrationdid not reach external concentration on Na2SO4 and on potassiumsalts was maintained between 12 and 17 mM. Vacuolar K+ concentration(approx. 142–191 mM on no salt) decreased on Na2SO4 andincreased on K2SO4 and KCl. There was no precise correlation between total or specific ionaccumulation (Na+, K+, SO42– and Cl and fresh-weightyield. Results suggest that selection results in adaptationin response to decreased water potential of the medium. Vaccinium corymbosum, blueberry, electronprobe X-ray microanalysis, callus, in vitro selection, salt tolerance, KCl, K2SO4, Na2SO4  相似文献   
2.
The effect of pH on host plant ‘preference’ for strains of R. trifolii was studied using the fluorescent ELISA technique. Four white clover cultivars were compared growing at pH 5, 6 and 7 inoculated with 1:1 mixtures of two strains of R. trifolii, CP3B and R4. The growth of these two bacterial strains was also studied at the same pH levels in pure culture. At pH 5, in pure culture, CP3B grew very well but R4 failed to reach the log phase. CP3B also produced the majority of nodules at this pH (86%). At pH 7, in pure culture, R4 grew better than CP3B and also produced 66% of the nodules in the nodulation experiment. However, there was good evidence of host cultivar ‘preference’ with cv. Milkanova having no nodules inhabited by CP3B at pH 7 but cv. S100 having 32%. The results are discussed from the point of view of the establishment of white clover in acid soils and the usefulness of the fluorescent ELISA technique for Rhizobium strain identification is also emphasised.  相似文献   
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4.
One of the most complex issues in the cloud computing environment is the problem of resource allocation so that, on one hand, the cloud provider expects the most profitability and, on the other hand, users also expect to have the best resources at their disposal considering the budget constraints and time. In most previous work conducted, heuristic and evolutionary approaches have been used to solve this problem. Nevertheless, since the nature of this environment is based on economic methods, using such methods can decrease response time and reducing the complexity of the problem. In this paper, an auction-based method is proposed which determines the auction winner by applying game theory mechanism and holding a repetitive game with incomplete information in a non-cooperative environment. In this method, users calculate suitable price bid with their objective function during several round and repetitions and send it to the auctioneer; and the auctioneer chooses the winning player based the suggested utility function. In the proposed method, the end point of the game is the Nash equilibrium point where players are no longer inclined to alter their bid for that resource and the final bid also satisfies the auctioneer’s utility function. To prove the response space convexity, the Lagrange method is used and the proposed model is simulated in the cloudsim and the results are compared with previous work. At the end, it is concluded that this method converges to a response in a shorter time, provides the lowest service level agreement violations and the most utility to the provider.  相似文献   
5.

Background  

Parkinson's disease (PD) is the second most common neurodegenerative disorder. As there is no definitive diagnostic test, its diagnosis is based on clinical criteria. Recently transcranial duplex scanning (TCD) of the substantia nigra in the brainstem has been proposed as an instrument to diagnose PD. We and others have found that TCD scanning of substantia nigra duplex is a relatively accurate diagnostic instrument in patients with parkinsonian symptoms. However, all studies on TCD so far have involved well-defined, later-stage PD patients, which will obviously lead to an overestimate of the diagnostic accuracy of TCD.  相似文献   
6.

Background

Neuropathic pain must be correctly diagnosed for optimal treatment. The questionnaire named Neuropathic Pain Symptom Inventory (NPSI) was developed in its original French version to evaluate the different symptoms of neuropathic pain. We hypothesized that the NPSI might also be used to differentiate neuropathic from non-neuropathic pain.

Methods

We translated the NPSI into German using a standard forward-backward translation and administered it in a case-control design to patients with neuropathic (n = 68) and non-neuropathic pain (headache and osteoarthritis, n = 169) to validate it and to analyze its discriminant properties, its sensitivity to change, and to detect neuropathic pain subgroups with distinct profiles.

Results

Using a sum score (the NPSI-G score), we found sensitivity to change (r between 0.37 and 0.5 for pain items of the graded chronic pain scale) and could distinguish between neuropathic and other pain on a group basis, but not for individual patients. Post hoc development of a discriminant score with optimized diagnostic properties to distinguish neuropathic pain from non-neuropathic pain resulted in an instrument with high sensitivity (91%) and acceptable specificity (70%). We detected six different pain profiles in the patient group with neuropathic pain; three profiles were found to be distinct.

Conclusions

The NPSI-G potentially combines the properties of a diagnostic tool and an instrument to identify subtypes of neuropathic pain.  相似文献   
7.

Background  

The zebrafish, Danio rerio, is used as a model organism to study vertebrate genetics and development. An effective enhancer trap (ET) in zebrafish using the Tol2 transposon has been demonstrated. This approach could be used to study embryogenesis of a vertebrate species in real time and with high resolution.  相似文献   
8.
Several areas of the Massachusetts Military Reservation (MMR) have soils with significant levels of high explosives (HE) contamination because of a long history of training and range activities (such as open burning, open detonation, disposal, and artillery and mortar firing). Site-specific transport and attenuation mechanisms were assessed in sandy soils for three contaminants of concern: the nitramine hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and the nitroaromatics 2,4-dinitrotolune (2,4-DNT) and 2,4,6-trinitrotoluene (TNT). For all three contaminants, linear distribution coefficients (Kd) were dependent on the fraction of organic carbon in soil. The nitroaromatics sorbed much more strongly than RDX in both soils. Over 120 hours, the desorption rate of RDX from field contaminated surface soil was much slower than its sorption rate, with the desorption Kd (1.5 L/kg) much higher than Kd for sorption (0.37 L/kg). Desorption of 2,4-DNT was negligible over 120 hours. Thus, applying sorption-derived Kd values for transport modeling may significantly overestimate the flux of explosives from MMR soils. Based on multiple component column transport tests, RDX will be the most mobile of these contaminants in MMR soils. In saturated columns packed with uncontaminated soil, RDX broke through rapidly, whereas the nitroaromatics were significantly attenuated by irreversible sorption or abiotic transformations.  相似文献   
9.
Sherk's cytogenetic findings are outlined, as far as they relate to the possible hybrid origin of Columnea querceti Oersted. Morphological evidence is provided to show that a hybrid origin is not impossible because there is a precedent for natural hybridization within the genus.  相似文献   
10.
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