Substantial evidence shows that the frequency of hydrological extremes has been changing and is likely to continue to change in the near future. Non-stationary models for flood frequency analyses are one method of accounting for these changes in estimating design values. The objective of the present study is to compare four models in terms of goodness of fit, their uncertainties, the parameter estimation methods and the implications for estimating flood quantiles. Stationary and non-stationary models using the GEV distribution were considered, with parameters dependent on time and on annual precipitation. Furthermore, in order to study the influence of the parameter estimation approach on the results, the maximum likelihood (MLE) and Bayesian Monte Carlo Markov chain (MCMC) methods were compared. The methods were tested for two gauging stations in Slovenia that exhibit significantly increasing trends in annual maximum (AM) discharge series. The comparison of the models suggests that the stationary model tends to underestimate flood quantiles relative to the non-stationary models in recent years. The model with annual precipitation as a covariate exhibits the best goodness-of-fit performance. For a 10% increase in annual precipitation, the 10-year flood increases by 8%. Use of the model for design purposes requires scenarios of future annual precipitation. It is argued that these may be obtained more reliably than scenarios of extreme event precipitation which makes the proposed model more practically useful than alternative models.
Increased circulating adhesion molecules in patients with obesity play an important role in the development of endothelial dysfunction/atherosclerosis. The aim of this study was to assess the contribution of various fat depots to the production of adhesion molecules in obesity. 12 women with 1st and 2nd degree of obesity, 13 women with 3rd degree of obesity and 14 lean age-matched women were included into study. Circulating levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin were measured by Luminex kits. mRNA expression of ICAM-1, VCAM-1, E-selectin, monocyte chemoattractant protein-1 (MCP-1), and CD68 in subcutaneous (SAT) and visceral adipose tissue (VAT) was measured by RT-PCR; ICAM-1 and VCAM-1 protein levels by Luminex kits, normalized to protein content. Obesity increased ICAM-1 and VCAM-1 mRNA expression and protein levels and CD68 mRNA expression in VAT. Expression of E-selectin and MCP-1 did not significantly differ between groups. Expression of ICAM-1 and VCAM-1 positively correlated with expression of CD68 in both adipose depots. In VAT, ICAM-1 and VCAM-1 expression and protein levels positively correlated with BMI. Obesity was associated with increased adhesion molecules mRNA expression and protein levels in VAT, but not in SAT. Increased adhesion molecules production in visceral fat may provide a novel direct link between visceral adiposity and increased risk of cardiovascular complications., L. Bošanská ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Longwave radiation, as part of the radiation balance, is one of the factors needed to estimate potential evapotranspiration (PET). Since the longwave radiation balance is rarely measured, many computational methods have been designed. In this study, we report on the difference between the observed longwave radiation balance and modelling results obtained using the two main procedures outlined in FAO24 (relying on the measured sunshine duration) and FAO56 (based on the measured solar radiation) manuals. The performance of these equations was evaluated in the April–October period over eight years at the Liz experimental catchment and grass surface in the Bohemian Forest (Czech Republic). The coefficients of both methods, which describe the influence of cloudiness factor and atmospheric emissivity of the air, were calibrated. The Penman-Monteith method was used to calculate the PET. The use of default coefficient values gave errors of 40–100 mm (FAO56) and 0–20 mm (FAO24) for the seasonal PET estimates (the PET was usually overestimated). Parameter calibration decreased the FAO56 error to less than 20 mm per season (FAO24 remained unaffected by the calibration). The FAO56 approach with calibrated coefficients proved to be more suitable for estimation of the longwave radiation balance.
The decrease in inorganic phosphate (Pi) content of 10-d-old Phaseolus vulgaris L. plants did not affect rates of photosynthesis (PN) and respiration (RD), leaf growth, and adenylate concentration. Two weeks of phosphate starvation influenced the ATP content and leaf growth more than PN and RD. The ATP concentration in the leaves of 15- and 18-d-old phosphate deficient (-P) plants after a light or dark period was at least half of that in phosphate sufficient (+P, control) plants. Similar differences were found in fresh and dry matter of leaves. However, PN declined to 50 % of control in 18-d-old plants only. Though the RD of -P plants (determined as both CO2 evolution and O2 uptake) did not change, an increased resistance of respiration to KCN and higher inhibition by SHAM (salicylhydroxamic acid) suggested a higher engagement of alternative pathway in respiration and a lower ATP production. The lower demand for ATP connected with inhibition of leaf growth may influence the ATP producing processes and ATP concentration. Thus, the ATP concentration in the leaves depends stronger on Pi content than on PN and RD. and M. Mikulska, J.-L. Bomsel, A. M. Rychter.
Photosynthetic induction responses to a sudden increase in photosynthetic photon flux density (PPFD) from lower background PPFD (0, 25, 50, and 100 μmol m-2 s-1) to 1 000 μmol m-2 s-1 were measured in leaves of Fagus crenata, Acer rufinerve Siebold & Zucc., and Viburnum furcatum growing in a gap and understory of a F. crenata forest in the Naeba mountains. In the gap, A. rufinerve exhibited more than 1.2-fold higher maximum net photosynthetic rate (PNmax) than F. crenata and V. furcatum. Meanwhile, in the understory F. crenata exhibited the highest PNmax among the three species. The photosynthetic induction period required to reach PNmax was 3-41 min. The photosynthetic responses to increase in PPFD depended on the background PPFD before increase in PPFD. The induction period required to reach PNmax was 2.5-6.5-fold longer when PPFD increased from darkness than when PPFD increased from 100 μmol m-2 s-1. The induction period was correlated with initial PN and stomatal conductance (gs) relative to maximum values before increase in PPFD. The relationship was similar between the gap and the understory. As the background PPFD increased, the initial PN and gs increased, indicating that the degrees of biochemical and stomata limitations to dynamic photosynthetic performance decreased. Therefore, photosynthetic induction responses to increase in PPFD became faster with the increasing background PPFD. The differences in time required to reach induction between species, as well as between gap and understory, were mainly due to the varying of relative initial induction states in PN and gs at the same background PPFD. and M. Naramoto, Q. Han, Y. Kakubari.
The correlation between serum gastrin levels and gastric acid secretion during 4 weeks of cimetidine administration (once daily) was investigated. Serum gastrin levels and gastric acid secretion were estimated on the 7th, 14th, 21st and 28th day after cimetidine administration (25 mg.kg'1, intragastrically). At the mentioned time intervals gastric acid secretion stimulated by histamine and pentagastrin was also studied. It was found that on the 14th and 21th day after cimetidine administration serum gastrin levels were significantly elevated. Basal gastric acid secretion after cimetidine administration was significantly decreased at all the observed time intervals. Histamine-stimulated gastric acid secretion was increased on the 14th, 21st and 28th day after cimetidine administration Hypoacidity was not followed at all time intervals by hypergastrinaemia (only on day 14 and 21 after cimetidine).
Toxoplasma gondii, a parasite infecting 20-60% of humans in various countries, influences the behaviour of infected animal and human hosts. Infected human subjects have changes in several of Cattell's and Cloninger's personality factors. Recently, three independent studies have shown that Rh-positive subjects are protected against the T. gondii-induced changes of reaction times and increased risk of traffic accidents. Here we searched for evidence of similar effects of RhD phenotype on toxoplasmosis- or aging-associated changes in the personality profile of about 302 blood donors. We found that Rh-positive and Rh-negative subjects responded differently to toxoplasmosis. In addition to the already known effects of toxoplasmosis on novelty seeking, self transcendence, superego strength and protension, we also found effects of RhD phenotype on ego strength, protension, and praxernia, as well as opposite effects of toxoplasmosis on ego strength, praxernia, ergic tension and cooperativeness in Rh-positive and Rh-negative subjects. Moreover, our results indicate that RhD phenotype might influence not only the effect of toxoplasmosis but also the effect of aging on specific personality traits.
The use of environmentally-friendly materials in hydraulic engineering (e.g. the stone lining of weirs at levees) calls for the more accurate estimation of the discharge coefficient for broad-crested weirs with a rough crest surface. However, in the available literature sources the discharge coefficient of broad-crested weirs is usually expressed for a smooth crest. The authors of this paper have summarized the theoretical knowledge related to the effect of weir crest surface roughness on the discharge coefficient. The method of determination of the head-discharge relation for broad-crested weirs with a rough crest surface is proposed based on known discharge coefficient values for smooth surfaces and on the roughness parameters of the weir. For selected scenarios the theoretical results were compared with experimental research carried out at the Laboratory of Water Management Research, Faculty of Civil Engineering (FCE), Brno University of Technology (BUT). and Používání přírodě blízkých materiálů ve vodním hospodářství (např. kamenná opevnění povrchu přelivů v ochranných hrázích) vyvolává požadavek přesnějšího stanovení součinitele průtoku pro přelivy se širokou a hydraulicky drsnou korunou. V dostupných literárních pramenech je součinitel průtoku přelivů se širokou korunou obvykle vyjádřen pouze pro hladký povrch koruny přelivu. Autoři článku shrnuli teoretické poznatky týkající se vlivu drsnosti povrchu koruny přelivu na součinitel průtoku a navrhli metodu pro stanovení způsobu hydraulického výpočtu konzumční křivky přepadu přes přeliv se širokou a drsnou korunou. Postup vychází ze znalosti součinitele průtoku přelivu s hladkou korunou a charakteristik drsnosti. Pro vybrané scénáře byly teoreticky vypočítané hodnoty porovnány s výsledky experimentálního výzkumu uskutečněného v Laboratoři vodohospodářského výzkumu Ústavu vodních staveb, Fakulty stavební, Vysokého učení technického v Brně.
The correct determination of material properties of construction materials from experiments is important not only during their development, but also during final verification. Specimens for testing mechanical properties of fiber-reinforced composites with a quasi-brittle matrix are usuall prepared by casting into a sutable mold. But they can be also prepared by cutting to desired shape from large body of material. The method of preparation may affect the measured values of material characteristics. In the case of sawed specimens, the fibers in surface layer are damaged, while in the case of casted specimens, fibers in surface layer tended to align with mold surface. The purpose of this article is to clarify the influence of these phenomena using numerical simulations. and Obsahuje seznam literatury
The influence of hormonal superovulation preparations of FSH (450 IU) or PMSG (1500 IU), on the levels of catecholamines (dopamine, norepinephrine and epinephrine) was studied in the oestrus period using radioenzymatic methods. The administration of FSH caused a significant increase in the concentrations of norepinephrine (NE) and epinephrine (EPI) in eminentia mediana (EM) of sheep (p<0.001 and p<0.01, respectively). The pituitary gland exhibited an increase in the level of norepinephrine after administration PMSG while no marked changes were recorded for epinephrine and dopamine (DA). The administration of FSH affected the increase in pituitary epinephrine (p<0.01). The hormonal stimulation by FSH resulted in a marked decrease of dopamine (p<0.05) as well as in , a significant increase of norepinephrine (p<0.05) and epinephrine (p<0.05) in the epiphysis. The comparison of the effect of hormonal preparations on the changes in catecholamine levels showed that the effect of FSH was observed mostly in eminentia mediana and the pituitary gland while that of PMSG was recorded in the epiphysis.