The aim of this contribution is to present a basic survey of publications dealing with the means of vibration suppression in several kinds of self-excitation. The attention is given to passive and active means using parametric excitation. A special attention is given to the latter and the necessary steps for answering important questions are formulated to initiate further investigation and especially application to real systems. and Obsahuje seznam literatury
Smoking is the most important cardiovascular (CV) risk factor. Stopping smoking halves the CV risk. Every clinician should provide a brief intervention with smokers. Intensive treatment should be available to those who need it. There are 37 Centers for Tobacco Dependence in the Czech Republic, which offer treatment including a psychobehavioral intervention and pharmacotherapy (varenicline, nicotine, bupropion). Czech physicians, pharmacists and nurses are regularly educated about smoking cessation. We describe the results of intensive treatment offered by our centers. Treatment includes screening (1 h), an intervention (2 h), and follow-up visits during the next 12 months. Among 3532 patients, 34.3 % had CO-validated abstinence at 12-months (including 489 patients who attended the screening visit + only the 12-month follow up visit). Among patients who underwent the intervention, the abstinence rate was 38.2 %. The majority of patients who underwent the intervention (N=2470) used some form of pharmacotherapy. After one year, the abstinence rate was 43.4 %, compared to 15.9 % (N=573) without pharmacotherapy. Only 28 % of patients came on the recommendation of a physician. Despite the decrease in CV risk following smoking cessation and the effectiveness of treatment, centers are underutilized., E. Králíková, A. Kmeťová, L. Štěpánková, K. Zvolská, V. Felbrová, S. Kulovaná, Z. Bortlíček, M. Blaha, K. Fraser., and Obsahuje bibliografii
Growth of the tocopherol-deficient vte1 mutant and Col-0 wild type of Arabidopsis thaliana in a sunlit glasshouse revealed both similarities and differences between genotypes. Photosynthetic capacity and leaf mesophyll features did not differ between mutant and wild type. Likewise, the total volume of water conduits (tracheary elements, TEs), sugar conduits (sieve elements, SEs), and sugar-loading cells (companion and phloem parenchyma cells) on a leaf area basis were unaffected by tocopherol deficiency. However, tocopherol deficiency yielded smaller and more numerous minor veins with fewer phloem cells and smaller TEs, resulting in greater ratios of TEs to SEs. The smaller TEs in the vte1 mutant may present a decreased risk for cavitation under high evaporative demand or in response to freezing. In turn, compensation for fewer phloem cells and smaller TEs by more numerous veins may bolster resistance to cavitation at no cost to photosynthetic capacity., J. J. Stewart, W. W. Adams, C. M. Cohu, B. Demmig-Adams., and Obsahuje bibliografické odkazy
Cadmium is often detected in areas contaminated by heavy metals and the incidence of this element in dangerous concentrations has been increasing due to anthropogenic activities. The aim of this research was to determine Cd concentrations in tissues, quantify compounds, pigments and enzymes, and to evaluate the gas exchange. Our aim was also to identify components that can modify and contribute to tolerance of Cassia alata against Cd toxicity. We used five Cd concentrations (0, 22, 44, 88, and 132 μM) to validate our hypothesis. The Cd concentrations in tissues of C. alata plants increased significantly, compared with the control treatment, in the following graduated sequence: root > leaf > stem. Progressive enhancement in glutathione (GSH) was verified in plants treated with all Cd concentrations used, when compared with treatment without Cd. Antioxidant enzyme activities presented similar patterns with progressive enhancements, being a desirable characteristic for plants with a potential to hyperaccumulate Cd. Our results suggest that C. alata plants can be used for phytoremediation programs. Their defense mechanism is based on Cd accumulation in roots, coupled with increase in GSH and the efficient activity of antioxidant enzymes that contribute to minimize the oxidative stress and consequently improve the protection of the metabolic machinery., J. R. R. Silva, A. R. Fernandes, M. L. Silva Junior, C. R. C. Santos, A. K. S. Lobato., and Obsahuje bibliografii
Canola (Brassica napus) is cultivated for oil as a biofuel crop. Few quantitative data concerning its tolerance to abiotic stresses has been presented. We evaluated the tolerances of canola to drought and salinity stresses in terms of parameter values in a macroscopic root water uptake model. We conducted an experiment using nine columns with two plants in each: three columns were under drought stresses, another three were under saline stress and others provided potential transpiration. Two soil moisture and salinity probes were inserted into each of the six columns under stress to monitor water content and electrical conductivity. Weight of the columns was manually measured to obtain daily transpiration. Water uptake at each depth and time was calculated by substituting linearly interpolated matric and osmotic potentials into the stress response function. Determined stress response functions indicated that canola is more sensitive to drought compared to Jatropha. While, it was found to be as tolerant as Jatropha to salinity stress in terms of transpiration. Matric potential was more determining than osmotic potential to root water uptake of canola.
Increase in salinity is predicted to affect plant growth and survival in most arid and semiarid regions worldwide. Mitragyna parvifolia (Roxb.) Korth. is an important medicinal tree species distributed throughout the semiarid regions of India; however, it is facing a threat of its extinction in its natural habitat. We examined the effects of increasing NaCl salinity on two-month-old M. parvifolia seedlings grown in an environment-controlled chamber and exposed to soils of different electrical conductivity (EC) caused by NaCl [0-5 (control), 5-10, 10-15, 15-20, and 20-25 dS m-1)] for 85 days. Seedlings transferred to soil of EC >15 dS m-¹ did not survive beyond 1 week. Increase in the Na+ concentration negatively correlated with their height and positively correlated with their water-use efficiency (WUE). However, leaf area, net photosynthetic rate (PN), stomatal conductance, and transpiration rate showed varying correlations and an overall decrease in these parameters compared with the control. At EC of 10-15 dS m-1, the seedling height was reduced by 37% and PN was lowered by 50% compared with those of the control. An increase in the Na+/K+ ratio was observed with increasing salinity. The maximum quantum efficiency of PSII significantly decreased with increasing salinity compared with the control. Our results suggest that the increase in salinity reduced the overall performance of the M. parvifolia seedlings. However, the maintenance of WUE and maximum quantum efficiency of PSII might help M. parvifolia to tolerate NaCl salinity of 15 dS m-1., A. Bidalia, M. Hanief, K. S. Rao., and Obsahuje bibliografii
Fuzzy algebra is a special type of algebraic structure in which classical addition and multiplication are replaced by maximum and minimum (denoted ⊕ and ⊗ , respectively). The eigenproblem is the search for a vector x (an eigenvector) and a constant λ (an eigenvalue) such that A⊗x=λ⊗x , where A is a given matrix. This paper investigates a generalization of the eigenproblem in fuzzy algebra. We solve the equation A⊗x=λ⊗B⊗x with given matrices A,B and unknown constant λ and vector x . Generalized eigenvectors have interesting and useful properties in the various computational tasks with inexact (interval) matrix and vector inputs. This paper studies the properties of generalized interval eigenvectors of interval matrices. Three types of generalized interval eigenvectors: strongly tolerable generalized eigenvectors, tolerable generalized eigenvectors and weakly tolerable generalized eigenvectors are proposed and polynomial procedures for testing the obtained equivalent conditions are presented.