This study presents the results of 32 laboratory experiments on local scour at a single pile and a 1 × 4 pile group for both uniform and non-uniform sediments under clear water conditions. The present study aims to evaluate the effects of different sediment beds made up of mixtures of sand and gravel (four-bed configurations) in d50 (1–3.5 mm) and gradation (1.4–3) ranges on scour depth for different flow discharges and flow depths. Further, the findings of the experiments are deployed to describe the effects of pile spacing and flow conditions on the local pier scour for both uniform and non-uniform bed granulometries. In addition, this study addresses the performance of some existing scourdepth predictors. Also, the corresponding results are suitable for validating the numerical models in local pier scour prediction importantly with non-uniform sediments. In summary, the results show that effects of sediment gradation dampen with increasing flow shallowness. Furthermore, the maximum scour depth at pile groups generally increases as pile spacing decreases for uniform sediments, whereas the mentioned trend was not observed for non-uniform sediments for the same flow and sediment conditions. Moreover, the experimental results revealed that bed sediment gradation is a controlling factor in the pile’s scour. Thus, the existing scour depth predictions could be highly improved by considering sediment gradation in the predictions. Finally, the conclusions drawn from this study provide crucial evidence for the protection of bridge foundations not only at the front pile but also at rear piles.
CO2 injection is a well-known Enhanced Oil Recovery (EOR) technique that has been used for years to improve oil extraction from carbonate rock and other oil reservoirs. Optimal functioning of CO2 injection requires a thorough understanding of how this method affects the petrophysical properties of the rocks. We evaluated pore-scale changes in these properties, notably porosity and absolute permeability, following injection of CO2-saturated water in two coquina outcrop samples from the Morro do Chaves Formation in Brazil. The coquinas are close analogues of Presalt oil reservoirs off the coast of southern Brazil. The effects of carbonated water injection were evaluated using a series of experimental and numerical steps before and after coreflooding: cleaning, basic petrophysics, microtomography (microCT) imaging, nuclear magnetic resonance (NMR) analyses, and pore network modeling (PNM). Our study was motivated by an earlier experiment which did not show the development of a wormhole in the center of the sample, with a concomitant increase in permeability of the coquina as often noted in the literature. We instead observed a substantial decrease in the absolute permeability (between 71 and 77%), but with little effect on the porosity and no wormhole formation. While all tests were carried out on both samples, here we present a comprehensive analysis for one of the samples to illustrate changes at the pore network level. Different techniques were used for the pore-scale analyses, including pore network modeling using PoreStudio, and software developed by the authors to enable a statistical analysis of the pore network. Results provided much insight in how injected carbonated water affects the pore network of carbonate rocks.
The frequent occurrence of monsoon winds usually leads to the formation of inverted soybean leaves. However, the effect of leaf inversion on photosynthetic capacity remains unclear. The responses of leaf anatomical traits, chlorophyll fluorescence induction kinetics parameters, photosynthetic capacity, and nonstructural carbohydrates of fully expanded leaves to inversion of leaves in two soybean cultivars were studied. Leaf inversion decreased the stomatal size and thickness of developed leaves. The net photosynthetic rate was significantly reduced under leaf inversion, which resulted from reduced excitation energy trapping and electron transport of PSII reaction center. Leaf inversion increased leaf temperature 10 d after leaf inversion but reduced the instantaneous water-use efficiency compared to normally oriented leaves. Due to the decreased light-saturated net photosynthetic rate, the soluble sugars of light-sensitive cultivar decreased significantly. In summary, leaf inversion deactivated the PSⅡ reaction centers, reduced photosynthesis and nonstructural carbohydrates in upper canopy soybean leaves.
The Tisza River Basin is an important area as it is a green corridor in which there are highly endangered habitats and a high level of biodiversity. The patterns in the species richness of invertebrates and the environmental conditions affecting these patterns are poorly studied in the grassy habitats in the lower reaches of the Tisza River Basin. The present study focuses on the effects of flooding, habitat and landscape features on the species richness of orthopterans at 24 grassland sites in two different landscapes. The relations between the explanatory variables and the pattern of diversity of orthopterans with different life-history traits were studied, using ordination and Generalized Linear Mixed Models. Although the influential factors for the different trait groups differed, we suggest that landscape features are the most important in shaping orthopteran assemblages, whereas habitat characteristics and flooding have comparatively little effect. Habitat characteristics affected only the non-xerophilous and Ensifera species and only the species richness of non-xerophilous orthopterans in flooded and non-flooded sites differed. We emphasize that even in countries where there are still considerable areas of high value natural grasslands, such as Hungary, non-protected meadows, linear grassy habitats (dikes, ditch banks, road verges, etc.) need more attention and should be given higher priority in the conservation of invertebrates., Attila Torma, Miklós Bozsó., and Obsahuje bibliografii
Respiration changes intrathoracic pressure and lung volumes in a cyclic manner, which affect cardiac function. Invasive ventricular pressure-volume (PV) loops can be recorded during ongoing mechanical ventilation or in transient apnea. No consensus exists considering ventilatory mode during PV loop recording. The objective of this study was to investigate the magnitude of any systematic difference of bi-ventricular PV loop variables recorded during mechanical ventilation versus apnea. PV loops were recorded simultaneously from the right ventricle and left ventricle in a closed chest porcine model during mechanical ventilation and in transient apnea (n=72). Variables were compared by regression analyses. Mechanical ventilation versus apnea affected regression coefficients for important PV variables including right ventricular stroke volume (1.22, 95% CI [1.08-1.36], p=0.003), right ventricular ejection fraction (0.90, 95% CI [0.81-1.00], p=0.043) and right ventricular arterial elastance (0.61, 95%CI [0.55-0.68], p<0.0001). Right ventricular pressures and volumes were parallelly shifted with Y-intercepts different from 0. Few left ventricular variables were affected, mainly first derivatives of pressure (dP/dt(max): 0.96, 95% CI [0.92-0.99], p=0.016, and dP/dt(min): 0.92, 95% CI [0.86-0.99], p=0.026), which might be due to decreased heart rate in apnea (Y-intercept -6.88, 95% CI [-12.22; -1.54], p=0.012). We conclude, that right ventricular stroke volume, ejection fraction and arterial elastance were mostly affected by apnea compared to mechanical ventilation. The results motivate future standardization of respiratory modality when measuring PV relationships.
Oral contraceptive pills (OCPs) have some strong advantages over more traditional types of contraception, including their consistently high contraceptive effect as well as multiple additional positive side effects. OCPs went through decades of intense pharmaceutical development and current formulas are well optimized – however, a handful of their negative side effects remain, including some that affect cardiovascular system, for example higher risk of hypertension, venous thromboembolism and increased arterial stiffness. The gold standard for arterial stiffness assessment is currently applanation tonometry, a method that relies on arterial pulse wave velocity measurement (PWV). Another possible method for arterial stiffness measurement is the use of the VaSera device, which measures cardio-ankle vascular index (CAVI). The aim of this study was to discover the effect of OCPs use on selected cardiovascular parameters related to arterial stiffness. We measured these cardiovascular parameters in the OCPs using group (OCP) and in the control group (CTRL) using applanation tonometer Sphygmocor and the VaSera device. Comparison of the data from both groups showed us significantly increased diastolic blood pressure (DBP) and carotid-radial pulse wave velocity (crPWV) as well as significantly lower subendocardial viability index (SVI) in the OCP. These results imply a negative effect of hormonal contraceptives on the cardiovascular system with most of the negative changes affecting the peripheral arteries. Despite this evidence supporting the hypothesis of OCPs having a negative effect on cardiovascular health, further research is necessary.
Trapped or residual air (or gas) is known to affect the multiphase hydraulic properties of both soils and rocks. Trapped air is known to impact many vadose zone hydrologic applications such as infiltration and flow in the capillary fringe, but is also a major issue affecting recoverable oil reserves. Although many studies have focused on the relationship between porosity and trapped gas saturation (Sgt) in sandstones, far fewer studies have been carried out for carbonate rocks. This work aims to analyze the influence of porous media properties on trapped gas saturation in carbonate rocks. For this we used thirteen Indiana Limestone and Silurian dolomite rock samples from the USA, and several coquinas from the Morro do Chaves formation in Brazil. Pore size distributions were obtained for all samples using Nuclear Magnetic Resonance (NMR), and Mercury Injection Capillary Pressure (MICP) data from three of the samples to determine their pore throat size distributions. Additionally, 3D microtomography (microCT) images were used to quantify macropore profiles and pore connectivities. Results indicate a lower capacity of gas trapping in carbonate rocks in which micro- and mesopores predominate. Results also indicate that in carbonate rocks, pore size exerts a greater influence on the ability of gas trapping compared to pore connectivity, so that rocks with a predominance of macropores have greater capacity for gas trapping, even when the macropores are well interconnected. These findings show that pore characteristics very much affect the processes governing gas trapping in carbonate rocks, and indirectly the multiphase hydraulic properties and recoverable oil reserves of carbonate rock reservoirs.
Objectives. At the beginning of the War in East-ern Ukraine, military personnel of the Armed Forces, National Guard of Ukraine (NGU), and soldiers of volunteer battalions, who had no combat experience for the first time faced the death of their comrades. This study aims to de-termine the effects of posttraumatic stress and combat losses on the mental health of combat-ants and to develop the typology of their resil-ience to extreme events.Sample and settings.N = 117 NGU male offic-ers (76% of contract military members and 24% of officers) participated in the study. These com-batants were withdrawn from the combat zone in June 2014 due to combat losses and the death of the unit commander.Hypothesis. After participating in hostilities, military personnel developed different types of personality resilience to the effects of traumatic stress.Statistical analyses. The participants’ typification of resilience and adaptation to extreme events was determined by hierarchical cluster analysis. The differences between groups in mean values were determined using Student’s t-test.Results. Four types of personality resilience to combat stressors were identified: “Those who predicted danger” (68.38%), “Those who were open to danger” (21.37%), “Those who identified themself with the role of the vic-tim” (6.83%), and “Those who hid their fear” (3.42%). The results showed that self-identifi-cation of a personality with symptoms of acute stress disorder affects the features of the imple-mentation of the anxiety buffer role. Limitations. The conclusions on the anxiety buffer role for the formation of PTSD require clarification and further studies. and Cíle. Na začátku války na východní Ukrajině vojáci ukrajinské armády (NGU – Národní gar-da Ukrajiny) a vojáci dobrovolnických praporů, kteří neměli bojové zkušenosti, se poprvé setka-li se smrtí svých spolubojovníků. Cílem tohoto výzkumu bylo zjistit dopady posttraumatického stresu a ztrát v boji na mentální zdraví vojáků a vytvořit typologii jejich resilience vůči extrém-ním událostem.Soubor. Výzkumu se zúčastnilo 117 mužů – dů-stojníků NGU (76 % smluvních vojáků a 24 % důstojníků z povolání). Tito vojáci byli staže-ni z bojové zóny v červnu 2014 kvůli ztrátám v boji a smrti velitele jednotky.Hypotéza. Po účasti v bojích si vojáci vyvinuli různé typy osobní resilience vůči dopadům trau-matického stresu.Statistická analýza. Typologizace resilience účastníků výzkumu a adaptace na extrémní události byla určena hierarchickou trsovou ana-lýzou. Získaná data byla popsána základními popisnými statistikami. Rozdíly mezi skupina-mi ve středních hodnotách byly zjištěny Studen-tovým t-testem.Výsledky. Byly vyčleněny čtyři typy resilience osobnosti vůči bojovým stresorům: „Ti, kdo predikovali nebezpečí“ (68,38 %), „Ti, kdo byli otevřeni nebezpečí“ (21,37 %), „Ti, kdo se identifikovali s rolí oběti“ (6,83 %), a „Ti, kdo skryli svůj strach“ (3,42 %). Výsledky ukázaly, že sebeidentifikace osoby se symptomy akutní stresové poruchy ovlivňuje prvky realizace ná-razníkové role úzkosti.Omezení studie. Závěry o nárazníkové roli úz-kosti pro utváření PTSD vyžadují objasnění a další výzkumy.
Secondary soil salinization causes plant stress, which can be relieved by different ratios of red to far-red light (R:FR). Our study aimed to elucidate the role of low R:FR ratios treatments on photosynthesis and growth of tomato seedlings in salinized soils. Tomato seedlings were treated under three R:FR ratios and calcium nitrate was applied simultaneously. The results showed that the treatments under low R:FR ratios stimulated growth parameters of tomato seedlings under calcium nitrate stress, the best impact being achieved at the R:FR ratio of 0.7 in this experiment. Low R:FR ratios treatments increased proline content as well as PSII maximum efficiency, actual electron transport operating efficiency, and photochemical quenching of tomato seedlings under calcium nitrate stress but decreased the value of nonphotochemical quenching. Moreover, low R:FR ratios treatments promoted net photosynthetic rate and increased the expression of a Rubisco gene. In conclusion, low R:FR ratios treatments could improve the salt resistance of greenhouse tomato plants.
Genetic predispositions may influence geographical and interethnic differences in COVID-19 prevalence and mortality in affected populations. Of the many genes implicated in COVID-19 progression, a substantial number have no direct functional link on virus transfer/viability or on the host immune system. To address this knowledge deficit, a large number of in silico studies have recently been published. However, the results of these studies often contradict the findings of studies involving real patients. For example, the ACE2 has been shown to play an important role in regulating coronavirus entry into cells, but none of its variations have been directly associated with COVID19 susceptibility or severity. Consistently was reported that increased risk of COVID-19 is associated with blood group A and with the APOE4 allele. Among other genes with potential impacts are the genes for CCR5, IL-10, CD14, TMPRSS2 and angiotensinconverting enzyme. Variants within the protein-coding genes OAS1 and LZTFL1 (transferred to the human genome from Neanderthals) are understood to be among the strongest predictors of disease severity. The intensive research efforts have helped to identify the genes and polymorphisms that contribute to SARS-CoV-2 infection and COVID-19 severity.