The aim of this article is to inform reader about the development steps which are used during the development of a critical control algorithm in aerospace industry. An article describes the motivation for use of automatic code generators for the development of critical control applications. A V-cycle model based design is introduced and its advantages and development practices that lead from design of a MATLAB/Simulink models to a real target application are depicted. and Obsahuje seznam literatury
Characteristics of in vivo nitráte reductase (NR, EC 1.6.6.1) activity in leaf tissue of the crassulacean acid metabolism (CAM) plant Notonia grandiflora DC. were determined. The pH optimum for the enzyme was 7.0. Among the five low molecular mass solvents tested, n-propanol was more effective in promoting NR activity. Supply of 1.0 % (v/v) M-propanol along with 0.5 % Triton X-100 was the most appropriate assay condition to bring about maximum NR activity (NRA), that was proportionally enhanced with duration of the incubation and mass of the leaf tissue. Leaf fragments of 2 to 4 mm slice width had maximal NRA. The highest NRA was obtained with 200 mM of nitráte supplied in the infiltration medium. NRA was higher in fully expanded, mature leaves than in tender and senescing leaves. The cellular nitráte content was strongly positively correlated with NRA in leaves of various physiological ages. The NRA/N03’ content ratio (index of nitráte utilization efQciency) was the highest for the tender leaves and the lowest for the senescing leaves. However, maximum total titratable acidity (malate production) was obtained for the fully expanded mature leaves in comparison with the other leaves. A positive and significant correlation (r = 0.92) was obtained between nitráte reduction and titratable acid content. The results are indicative of a possible role of nitráte reduction in the regulation of noctumal acid production in the CAM plants.
Chronic stress is a crucial public issue that occurs when a person
is repetitively stimulated by various stressors. Previous
researches have reported that chronic stress induces
spermatogenesis dysfunction in the reproductive system, but its
molecular mechanisms remain unclear. The nectin protein family,
including nectin-1 to nectin-4, is Ca2+-independent
immunoglobulin-like cell adhesion molecules, that are widely
expressed in the hippocampus, testicular tissue, epithelial cells
and other sites. Nectin-3 contributes to the sperm development
at the late stage, and the abnormal expression of nectin-3
impairs spermatogenesis. Some recent studies have
demonstrated that stress induces a decrease in nectin-3
expression in the hippocampus via corticotropin-releasing
hormone (CRH) to corticotropin-releasing hormone receptor 1
(CRHR1) pathway. Here, we tested whether chronic stress also
caused a reduction in nectin-3 expression in the testis. We
established a chronic social defeat stress paradigm, which
provides naturalistic and complex chronic stress in male C57BL/6
mice. After 25 days of chronic social defeat stress, the mice
showed weight loss, thymic atrophy and some other typical
symptoms of chronic stress (e.g. anxiety-like behavior and social
avoidance behavior). We found gonad atrophy, testicular
histological structure changes and semen quality reductions in
the stressed mice. The stressed male mice significantly spent
more time to impregnate the female mice than the control male
mice. Moreover, nectin-3 protein levels in stressed mice were
significantly decreased in the testes compared with those in
control mice. In addition, we found that the CRHR1 expression
level was increased in the testes of stressed mice. Therefore, we
demonstrated a decreased level of nectin-3 expression and
an increase in CRHR1 expression in the testis after exposure to
chronic stress, which may provide a potential therapeutic target
for the spermatogenesis dysfunction induced by chronic stress.
For assessment of safety and durability of any large-scale concrete structure, prediction of the behaviour of the structure under various service and extreme conditions is crucial. To perform reliable analysis of the complete structure, a sufficiently realistic but still feasible numerical model must be used, in which the relevant physical phenomena are reflected. Therefore, a constitutive model for concrete including effects on moisture and heat transfer, cement hydration, creep, shrinkage and optionally microcracking of concrete should be chosen.
The present paper focuses on the simulation of the service life of a NPP containment, aiming to determine the material and model parameters to enable reliable prediction of durability and structural behaviour under various conditions. The purpose of the work is to provide a numerical model calibrated using existing measurements to predict the long-term behaviour reliably. Extensive in situ measurements are used to calibrate the model and to check the validity of model hypotheses. Moreover, the material model parameters are systematically re-calibrated based on continuous monitoring of the structure. The structural integrity test is reanalysed numerically to show the model capability of predicting behaviour of the structure under given loading and climate conditions. and Obsahuje seznam literatury