264 results on '"Jiří F"'
Search Results
152. Carbon isotope chemostratigraphy of the Llandovery in northern peri-Gondwana: new data from the Barrandian area, Czech Republic
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Jiří Frýda and Petr Štorch
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carbon isotope chemostratigraphy ,Llandovery ,Barrandian area ,northern peri-Gondwana ,Czech Republic. ,Geology ,QE1-996.5 - Abstract
The first complete δ13Corg record of the uppermost Hirnantian to lower Telychian strata of the Barrandian area (northern peri-Gondwana) is presented based on 168 new samples. The new data from the study area reveal that the evolution of the Llandoverian organic carbon isotope reservoir was similar to that on other palaeoplates, but it differs from the development of the coeval carbonate carbon isotope reservoir in the absence of two δ13C excursions (i.e. the early Aeronian positive excursion in the upper part of the Demirastrites triangulatus graptolite Biozone and a negative excursion occurring close to the boundary between the Cystograptus vesiculosus and Coronograptus cyphus graptolite biozones).
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- 2014
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153. Digestate from Biogas Plants is an Attractive Alternative to Mineral Fertilisation of Kohlrabi
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Tomas Losak, Jaroslav Hlusek, Andrea Zatloukalova, Ludmila Musilova, Monika Vitezova, Petr Skarpa, Tereza Zlamalova, Jiri Fryc, Tomas Vitez, Jan Marecek, and Anna Martensson
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Biogas plant ,Digestate ,Fertilisation ,Soil ,Kohlrabi ,Yields ,Quality. ,Technology ,Economic growth, development, planning ,HD72-88 - Abstract
This study examined the potential for the use of digestate from biogas plants for the fertilisation of kohlrabi. Kohlrabi was grown in two pot experiments in consecutive years using digestate, mineral fertiliser (urea) with a nitrogen (N) content equivalent to that in the digestate, mineral fertiliser with N, phosphate (P), potassium (K) and magnesium (Mg) contents equivalent to the digestate, and an unfertilised control. At harvest, the soil receiving the digestate application had higher P, K and Mg contents than the control and the urea treatment. The soil Nmin content was balanced in all fertilised treatments. Soil pH was unaffected by all treatments. Kohlrabi bulbs from the unfertilised control had the lowest weight, nitrate content and ascorbic acid content. Digestate and NPKMg fertiliser treatments increased bulb weight compared with the N-only urea treatment. Ascorbic acid content did not differ between fertilised treatments. There were no differences in bulb nitrate content between the mineral fertiliser treatments, but digestate application gave a low nitrate content. Bulb macroelement contents varied irregularly among treatments.
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- 2014
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154. Sexual Life of Women With Mayer-Rokitansky-Küster-Hauser Syndrome After Laparoscopic Vecchietti Vaginoplasty
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Zlatko Pastor, MD, PhD, Jiří Froněk, MD, PhD, Marta Nováčková, MD, PhD, and Roman Chmel, MD, PhD
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Mayer-Rokitansky-Küster-Hauser Syndrome ,Vecchietti Vaginoplasty ,Neovagina ,Female Sexual Dysfunction ,Medicine - Abstract
Introduction: Adequate anatomic and physiologic functions of the genitalia are fundamental prerequisites for sexual well-being and reproduction. Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) compromises female sexual life and makes reproduction impossible. Aim: To assess the psychosexual effect of vaginal reconstruction using the laparoscopic Vecchietti technique in patients with MRKHS. Methods: Forty-two patients with MRKHS who underwent laparoscopic Vecchietti vaginoplasty were included. Their partners also were interviewed. A control group of 45 age-matched, childless, sexually active women were examined during the same period. Main Outcome Measures: A gynecologic examination was performed to determine the anatomic outcome. Psychosexual function was evaluated with the Female Sexual Distress Scale–Revised (FSDS-R), the Female Sexual Function Index (FSFI), and a semistructured interview. Genital self-image was evaluated using the Female Genital Self-Image Scale (FGSIS). Results: Average neovagina length (7.0 ± 9.6 cm) in the MRKHS group was significantly shorter than the vaginal length in the control group (9.3 ± 2.5 cm). Women with a neovagina reported satisfactory sexual function (FSFI score = 29 ± 2.7) that was not significantly different from the control group (P < .05); however, they also had significantly higher levels of distress (FSDS-R score = 14.5 ± 6.5) and were not satisfied with their genitals (FGSIS score = 22.0 ± 2.4) compared with the control group. Conclusion: Sexual function in women with MRKHS can be restored successfully by vaginoplasty; however, they have higher rates of distress and are less satisfied with their genitals. Pastor Z, Fronĕk J, Nováčková M, Chmel R. Sexual Life of Women With Mayer-Rokitansky-Küster-Hauser Syndrome After Laparoscopic Vecchietti Vaginoplasty. Sex Med 2017;5:e106–e113.
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- 2017
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155. Live tracking of moving samples in confocal microscopy for vertically grown roots
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Daniel von Wangenheim, Robert Hauschild, Matyáš Fendrych, Vanessa Barone, Eva Benková, and Jiří Friml
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confocal microscopy ,tracking ,gravitropism ,root ,time-lapse ,gravistimulation ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Roots navigate through soil integrating environmental signals to orient their growth. The Arabidopsis root is a widely used model for developmental, physiological and cell biological studies. Live imaging greatly aids these efforts, but the horizontal sample position and continuous root tip displacement present significant difficulties. Here, we develop a confocal microscope setup for vertical sample mounting and integrated directional illumination. We present TipTracker – a custom software for automatic tracking of diverse moving objects usable on various microscope setups. Combined, this enables observation of root tips growing along the natural gravity vector over prolonged periods of time, as well as the ability to induce rapid gravity or light stimulation. We also track migrating cells in the developing zebrafish embryo, demonstrating the utility of this system in the acquisition of high-resolution data sets of dynamic samples. We provide detailed descriptions of the tools enabling the easy implementation on other microscopes.
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- 2017
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156. Simultaneous liver kidney transplantation and (bilateral) nephrectomy through a midline is feasible and safe in polycystic disease.
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Ina Jochmans, Diethard Monbaliu, Laurens J Ceulemans, Jacques Pirenne, and Jiri Fronek
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Medicine ,Science - Abstract
In Eurotransplant, 50% of simultaneous liver kidney transplantations (SLK) are performed for polycystic disease. Classically, liver and kidney are transplanted in two steps: liver through a subcostal incision, kidney through a separate oblique incision. Liver and kidney volume can make this 'two-step' procedure challenging, especially if simultaneous native nephrectomy is indicated. A 'one-step' SLK through a xiphopubic laparotomy might be a safe alternative, facilitating mobilization of the voluminous polycystic liver and native nephrectomy whilst offering access to iliac fossae for kidney transplantation. One-step SLK procedures for polycystic disease were introduced in 08/2013 at IKEM Prague (n = 6) and 11/2014 at University Hospitals Leuven (n = 6). Feasibility and safety of the one-step technique were investigated. We compared surgical data and outcomes obtained with the one-step technique to all consecutive two-step procedures performed for polycystic disease at the University Hospitals Leuven between 2008-2014 (n = 23). Median (interquartile range) are given. One-step SLK offered broad and adequate exposure for the hepatectomy, nephrectomies and transplantations, which were all uneventful. Morbidity, patient (100% vs 91%, p = 0.53) and graft survival (100% graft survival for liver and kidney in both groups) were comparable between one-step and two-step SLK. Liver cold ischaemia time was comparable [6.0 (4.4-7.6) vs. 7.1 (3.9-7.3), p = 0.077], kidney cold ischaemia time was shorter in one-step compared to two-step SLK [8.1 (6.4-9.3) vs. 11.7 (10.0-14.0), p
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- 2017
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157. Rapid Material Appearance Acquisition Using Consumer Hardware
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Jiří Filip, Radomír Vávra, and Mikuláš Krupička
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measurement setup ,material appearance ,BTF ,ABRDF ,visual psychophysics ,Chemical technology ,TP1-1185 - Abstract
A photo-realistic representation of material appearance can be achieved by means of bidirectional texture function (BTF) capturing a material’s appearance for varying illumination, viewing directions, and spatial pixel coordinates. BTF captures many non-local effects in material structure such as inter-reflections, occlusions, shadowing, or scattering. The acquisition of BTF data is usually time and resource-intensive due to the high dimensionality of BTF data. This results in expensive, complex measurement setups and/or excessively long measurement times. We propose an approximate BTF acquisition setup based on a simple, affordable mechanical gantry containing a consumer camera and two LED lights. It captures a very limited subset of material surface images by shooting several video sequences. A psychophysical study comparing captured and reconstructed data with the reference BTFs of seven tested materials revealed that results of our method show a promising visual quality. Speed of the setup has been demonstrated on measurement of human skin and measurement and modeling of a glue dessication time-varying process. As it allows for fast, inexpensive, acquisition of approximate BTFs, this method can be beneficial to visualization applications demanding less accuracy, where BTF utilization has previously been limited.
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- 2014
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158. Measurement of Heat Losses on The Milking Machine Electric Motor at Various Regulations of Vacuum Using Methods of Thermal Imagery
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Jan Kudělka, Jiří Fryč, and Petr Trávníček
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milking machine ,rotary vacuum pump ,electric motor ,control valve ,frequency converter ,thermal camera ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
To ensure the desirable vacuum in the milking machines, use is currently made predominantly of rotary vacuum pumps. These vacuum pumps are driven by a squirrel-cage induction motor. Until recently, the vacuum in the system to achieve the required value was controlled by a main control valve sucking in ambient air into the system. During the milking process itself and during other activities (flushing, sanitation), this control method consumed a large amount of electricity. The technical solution to electricity demand reduction was introduced with the emergence and development of frequency converters. The frequency converters control the operation of the asynchronous electric motor so that the actual delivery of the vacuum pumps equals the volume of air sucked into the vacuum pipe. The motor supply by the frequency converter brings about a host of adverse phenomena. This paper is dedicated to motor heating and heat losses on the surface of the electric motor at different regulations of vacuum in milking machines. The objective of the paper is to determine the immediate specific heat flows along the surface of the electric motor of the milking machine during milking using a control valve regulation and a control using the frequency converter, and compare the resulting value. The specific heat flows were determined by means of a non-traditional method of temperature field measurement using a system of thermal imagery. The calculated and measured data obtained from both these systems were statistically evaluated and compared. Use was made of a milking machine located in the cooperative Hospodářské obchodní družstvo (HOD) Jabloňov.
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- 2014
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159. The Influence of Digestate and Mineral Fertilisers on Yields and Content of Nitrates and Ascorbic Acid in Kohlrabi Bulbs
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Tomáš Lošák, Tereza Zlámalová, Monika Vítězová, Jaroslav Hlušek, Petr Škarpa, Jiří Fryč, Tomáš Vítěz, and Jan Mareček
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digestate ,urea ,mineral fertilisers ,kohlrabi ,yields ,ascorbic acid ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
In a one-year vegetation pot experiment we compared the effect of the digestate from a biogas plant and mineral fertilisers on yield and quality parameters of kohlrabi, variety Moravia. Four treatments were used in the trial: 1) untreated control, 2) urea, 3) digestate, 4) urea, triple super phosphate, KCl, MgSO4. The rate of N was the same in treatments 2–4, i.e. 1.5 g N/pot. In treatment 4 the rate of P, K and Mg corresponded with the rate of these nutrients in the digestate treatment (3). The inhibited growth of kohlrabi after the application of NPKMg (4) was obviously the consequence of early planting after the application of fertilisers (5 days) and of the salinity of the small content of soil in the pot and resulted in the lowest weight of single bulbs (69 g), followed by the unfertilised control treatment (75 g). After the application of the digestate (treatment 3) the weight of single bulbs significantly increased (126 g) compared to the urea treatment (101 g) and all the other treatments. The content of ascorbic acid in the fertilised treatments did not differ (441–458 mg/kg) but it increased significantly compared to the unfertilised treatment (398 mg/kg). There were significant differences among all the fertilised treatments (1–2–3–4) in the bulb nitrate content (346–1,147–815–1,091 mg NO3−/kg fresh matter, respectively). After digestate application their content decreased significantly to 815 mg NO3−/kg fresh matter. Digestate treatment resulted in comparable or better yields and qualitative parameters compared to all the other treatments.
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- 2014
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160. Measurements of Flat-Plate Milk Coolers
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Vlastimil Nejtek, Jiří Fryč, and Josef Los
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plate cooler ,milk cooling ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
Measuring in laboratory conditions was performed with the aim to collect a sufficient quantity of measured data for the qualified application of flat-plate coolers in measuring under real operating conditions. The cooling water tank was filled with tap water; the second tank was filled with water at a temperature equivalent to freshly milked milk. At the same time, pumps were activated that delivered the liquids into the flat-plate cooler where heat energy was exchanged between the two media. Two containers for receiving the run-out liquid were placed on the outputs from the cooler; here, temperature was measured with electronic thermometer and volume was measured with calibrated graduated cylinder. Flow rate was regulated both on the side of the cooling fluid and on the side of the cooled liquid by means of a throttle valve. The measurements of regulated flow-rates were repeated several times and the final values were calculated using arithmetic average. To calculate the temperature coefficient and the amount of brought-in and let-out heat, the volume measured in litres was converted to weight unit. The measured values show that the volume of exchanged heat per weight unit increases with the decreasing flow-rate. With the increasing flow-rate on the throttled side, the flow-rate increases on the side without the throttle valve. This phenomenon is caused by pressure increase during throttling and by the consequent increase of the diameter of channels in the cooler at the expense of the opposite channels of the non-throttled part of the circuit. If the pressure is reduced, there is a pressure decrease on the external walls of opposite channels and the flow-rate increases again. This feature could be utilised in practice: a pressure regulator on one side could regulate the flow-rate on the other side. The operating measurement was carried out on the basis of the results of laboratory measurements. The objective was to determine to what extent the use of flat-plate coolers under specific conditions results in cost reduction and improved milk cooling process. The measurement was performed in several cycles. The first measurement took place in the existing system without the use of the flat-plate cooler. The volume of drawn milk was monitored throughout the milking process along with its temperature, temperature in the tank and electricity consumption of the cooling system. At the second stage, the flat-plate cooler was introduced into the cooling process, which was followed by monitoring the milk and cooling water volume, their temperature, temperature in the tank and electricity consumption of the cooling system. The measured data indicate considerable power cost reduction if upstream flat-plate coolers are applied.
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- 2014
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161. Different Modes of Action of Genetic and Chemical Downregulation of Histone Deacetylases with Respect to Plant Development and Histone Modifications
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Gabriela Lochmanová, Ivana Ihnatová, Hana Kuchaříková, Sylva Brabencová, Dagmar Zachová, Jiří Fajkus, Zbyněk Zdráhal, and Miloslava Fojtová
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arabidopsis thaliana ,epigenetics ,histone ,mass spectrometry ,post-translational modifications ,sodium butyrate ,trichostatin a ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
A high degree of developmental plasticity enables plants to adapt to continuous, often unfavorable and unpredictable changes in their environment. At the molecular level, adaptive advantages for plants are primarily provided by epigenetic machinery including DNA methylation, histone modifications, and the activity of noncoding RNA molecules. Using a mass spectrometry-based proteomic approach, we examined the levels of acetylated histone peptide forms in Arabidopsis plants with a loss of function of histone deacetylase 6 (HDA6), and in plants germinated in the presence of HDA inhibitors trichostatin A (TSA) and sodium butyrate (NaB). Our analyses revealed particular lysine sites at histone sequences targeted by the HDA6 enzyme, and by TSA- and NaB-sensitive HDAs. Compared with plants exposed to drugs, more dramatic changes in the overall profiles of histone post-translational modifications were identified in hda6 mutants. However, loss of HDA6 was not sufficient by itself to induce hyperacetylation to the maximum degree, implying complementary activities of other HDAs. In contrast to hda6 mutants that did not exhibit any obvious phenotypic defects, the phenotypes of seedlings exposed to HDA inhibitors were markedly affected, showing that the effect of these drugs on early plant development is not limited to the modulation of histone acetylation levels.
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- 2019
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162. Turbine Cascades of Last Stage Blades for Wide Range of Operating Conditions
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Ondrej Novak, Marek Bobcik, Martin Luxa, Jaroslav Fort, Bartolomej Rudas, Jaroslav Synac, David Simurda, Jiri Furst, Jan Halama, Vladimir Hric, Jaromir Prihoda, and Zdenek Simka
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turbine ,cascade ,last stage blade ,CFD ,experimental validation ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Recent trends in the electric energy market such as biomass, waste incineration or combined cycle power plants require innovative solutions in steam turbine design. Variable operating conditions cause significant changes in flow field surrounding the steam turbine last stage blades. Therefore, the enlargement of operating range for last stage blades presents new challenges in design of turbine cascades. Several turbine cascades were designed and analyzed by commercial and in-house software of CTU Prague. Selected profiles were experimentally validated in the high-speed wind tunnel for 2D cascade measurements of the Institute of Thermomechanics of the Czech Academy of Sciences which is equipped by an adjustable supersonic inlet nozzle, perforated inserts at side walls and adjustable perforated tailboard. Comparisons are presented of numerical results with optical and pneumatic measurements for a wide range of inlet and outlet Mach numbers for optimized hub and tip profile cascades.
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- 2019
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163. Reorientation of Cortical Microtubule Arrays in the Hypocotyl of Arabidopsis thaliana Is Induced by the Cell Growth Process and Independent of Auxin Signaling
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Maciek Adamowski, Lanxin Li, and Jiří Friml
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microtubules ,cortical microtubule arrays ,cortical microtubule array reorientation ,auxin ,cell growth ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Cortical microtubule arrays in elongating epidermal cells in both the root and stem of plants have the propensity of dynamic reorientations that are correlated with the activation or inhibition of growth. Factors regulating plant growth, among them the hormone auxin, have been recognized as regulators of microtubule array orientations. Some previous work in the field has aimed at elucidating the causal relationship between cell growth, the signaling of auxin or other growth-regulating factors, and microtubule array reorientations, with various conclusions. Here, we revisit this problem of causality with a comprehensive set of experiments in Arabidopsis thaliana, using the now available pharmacological and genetic tools. We use isolated, auxin-depleted hypocotyls, an experimental system allowing for full control of both growth and auxin signaling. We demonstrate that reorientation of microtubules is not directly triggered by an auxin signal during growth activation. Instead, reorientation is triggered by the activation of the growth process itself and is auxin-independent in its nature. We discuss these findings in the context of previous relevant work, including that on the mechanical regulation of microtubule array orientation.
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- 2019
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164. PIN2 Polarity Establishment in Arabidopsis in the Absence of an Intact Cytoskeleton
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Matouš Glanc, Matyáš Fendrych, and Jiří Friml
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cell polarity ,polarity establishment ,PIN auxin efflux carriers ,cytoskeleton ,actin ,microtubules ,live-cell imaging ,Microbiology ,QR1-502 - Abstract
Cell polarity is crucial for the coordinated development of all multicellular organisms. In plants, this is exemplified by the PIN-FORMED (PIN) efflux carriers of the phytohormone auxin: The polar subcellular localization of the PINs is instructive to the directional intercellular auxin transport, and thus to a plethora of auxin-regulated growth and developmental processes. Despite its importance, the regulation of PIN polar subcellular localization remains poorly understood. Here, we have employed advanced live-cell imaging techniques to study the roles of microtubules and actin microfilaments in the establishment of apical polar localization of PIN2 in the epidermis of the Arabidopsis root meristem. We report that apical PIN2 polarity requires neither intact actin microfilaments nor microtubules, suggesting that the primary spatial cue for polar PIN distribution is likely independent of cytoskeleton-guided endomembrane trafficking.
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- 2019
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165. Efficient Modulation and Processing Method for Closed-Loop Fiber Optic Gyroscope with Piezoelectric Modulator
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Michal Skalský, Zdeněk Havránek, and Jiří Fialka
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fiber-optic gyroscope ,Sagnac interferometer ,piezoelectric phase modulator ,closed-loop configuration ,all-fiber ,single mode ,Chemical technology ,TP1-1185 - Abstract
This paper presents a simple method for compensating the Sagnac phase shift in an interferometric fiber-optic gyroscope (I-FOG) with a piezoelectric modulator. The common advantages of I-FOGs with closed-loop compensation are linearized output characteristics and insensitivity to the light source power, including its time and thermal-induced fluctuations. Whereas closed-loop operation is normally achieved via ramp modulation requiring an electro-optic modulator, all-fiber architectures with a piezoelectric modulator are mostly limited to open loop. Nevertheless, such setups can more conveniently utilize a less expensive single-mode fiber with depolarized light and do not require any custom-made components. The proposed method allows us to combine the advantages of both approaches. Closed-loop compensation is ensured by adding further sinusoidal modulation to the common biasing modulation, such that the Sagnac phase shift is compensated solely at the sampling instants. We describe and experimentally demonstrate the proposed approach, utilizing a test setup to compare our closed-loop solution with open-loop operation. The results denote that the method provides a cost-efficient manner of performance improvement compared to the open-loop I-FOGs based on a piezoelectric modulator.
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- 2019
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166. Diagnosis of Intermittently Faulty Units at System Level
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Viktor Mashkov, Jirí Fiser, Volodymyr Lytvynenko, and Maria Voronenko
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complex systems ,self-diagnosis ,intermittent fault ,diagnosis procedure ,Bibliography. Library science. Information resources - Abstract
Mostly, diagnosis at a system level intends to identify only permanently faulty units. In the paper, we consider the case when both permanently and intermittently faulty units can occur in the system. Identification of intermittently faulty units has some specifics which we have considered in this paper. We also suggest the method which allows for distinguishing among different types of intermittent faults. A diagnosis procedure was suggested for each type of intermittent fault.
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- 2019
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167. Comparative Dissection of Three Giant Genomes: Allium cepa, Allium sativum, and Allium ursinum
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Vratislav Peška, Terezie Mandáková, Veronika Ihradská, and Jiří Fajkus
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Allium ,plant genome ,repeats ,retrotransposon ,satellite ,telomere ,rDNA ,RepeatExplorer ,TAREAN ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Knowledge of the fascinating world of DNA repeats is continuously being enriched by newly identified elements and their hypothetical or well-established biological relevance. Genomic approaches can be used for comparative studies of major repeats in any group of genomes, regardless of their size and complexity. Such studies are particularly fruitful in large genomes, and useful mainly in crop plants where they provide a rich source of molecular markers or information on indispensable genomic components (e.g., telomeres, centromeres, or ribosomal RNA genes). Surprisingly, in Allium species, a comprehensive comparative study of repeats is lacking. Here we provide such a study of two economically important species, Allium cepa (onion), and A. sativum (garlic), and their distantly related A. ursinum (wild garlic). We present an overview and classification of major repeats in these species and have paid specific attention to sequence conservation and copy numbers of major representatives in each type of repeat, including retrotransposons, rDNA, or newly identified satellite sequences. Prevailing repeats in all three studied species belonged to Ty3/gypsy elements, however they significantly diverged and we did not detect them in common clusters in comparative analysis. Actually, only a low number of clusters was shared by all three species. Such conserved repeats were for example 5S and 45S rDNA genes and surprisingly a specific and quite rare Ty1/copia lineage. Species-specific long satellites were found mainly in A. cepa and A. sativum. We also show in situ localization of selected repeats that could potentially be applicable as chromosomal markers, e.g., in interspecific breeding.
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- 2019
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168. Telomeres in Plants and Humans: Not So Different, Not So Similar
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Petra Procházková Schrumpfová, Miloslava Fojtová, and Jiří Fajkus
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telomere ,telomerase ,human ,Arabidopsis ,aging ,chromatin ,epigenetics ,review ,Cytology ,QH573-671 - Abstract
Parallel research on multiple model organisms shows that while some principles of telomere biology are conserved among all eukaryotic kingdoms, we also find some deviations that reflect different evolutionary paths and life strategies, which may have diversified after the establishment of telomerase as a primary mechanism for telomere maintenance. Much more than animals, plants have to cope with environmental stressors, including genotoxic factors, due to their sessile lifestyle. This is, in principle, made possible by an increased capacity and efficiency of the molecular systems ensuring maintenance of genome stability, as well as a higher tolerance to genome instability. Furthermore, plant ontogenesis differs from that of animals in which tissue differentiation and telomerase silencing occur during early embryonic development, and the “telomere clock” in somatic cells may act as a preventive measure against carcinogenesis. This does not happen in plants, where growth and ontogenesis occur through the serial division of apical meristems consisting of a small group of stem cells that generate a linear series of cells, which differentiate into an array of cell types that make a shoot and root. Flowers, as generative plant organs, initiate from the shoot apical meristem in mature plants which is incompatible with the human-like developmental telomere shortening. In this review, we discuss differences between human and plant telomere biology and the implications for aging, genome stability, and cell and organism survival. In particular, we provide a comprehensive comparative overview of telomere proteins acting in humans and in Arabidopsis thaliana model plant, and discuss distinct epigenetic features of telomeric chromatin in these species.
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- 2019
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169. Relative Contribution of PIN-Containing Secretory Vesicles and Plasma Membrane PINs to the Directed Auxin Transport: Theoretical Estimation
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Sander Hille, Maria Akhmanova, Matouš Glanc, Alexander Johnson, and Jiří Friml
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auxin ,polar auxin transport ,PIN transporters ,secretion ,3D-SIM microscopy ,mathematical modeling ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The intercellular transport of auxin is driven by PIN-formed (PIN) auxin efflux carriers. PINs are localized at the plasma membrane (PM) and on constitutively recycling endomembrane vesicles. Therefore, PINs can mediate auxin transport either by direct translocation across the PM or by pumping auxin into secretory vesicles (SVs), leading to its secretory release upon fusion with the PM. Which of these two mechanisms dominates is a matter of debate. Here, we addressed the issue with a mathematical modeling approach. We demonstrate that the efficiency of secretory transport depends on SV size, half-life of PINs on the PM, pH, exocytosis frequency and PIN density. 3D structured illumination microscopy (SIM) was used to determine PIN density on the PM. Combining this data with published values of the other parameters, we show that the transport activity of PINs in SVs would have to be at least 1000× greater than on the PM in order to produce a comparable macroscopic auxin transport. If both transport mechanisms operated simultaneously and PINs were equally active on SVs and PM, the contribution of secretion to the total auxin flux would be negligible. In conclusion, while secretory vesicle-mediated transport of auxin is an intriguing and theoretically possible model, it is unlikely to be a major mechanism of auxin transport in planta.
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- 2018
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170. Calcium: The Missing Link in Auxin Action
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Steffen Vanneste and Jiří Friml
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auxin ,calcium ,signal transduction ,auxin transport ,Botany ,QK1-989 - Abstract
Due to their sessile lifestyles, plants need to deal with the limitations and stresses imposed by the changing environment. Plants cope with these by a remarkable developmental flexibility, which is embedded in their strategy to survive. Plants can adjust their size, shape and number of organs, bend according to gravity and light, and regenerate tissues that were damaged, utilizing a coordinating, intercellular signal, the plant hormone, auxin. Another versatile signal is the cation, Ca2+, which is a crucial second messenger for many rapid cellular processes during responses to a wide range of endogenous and environmental signals, such as hormones, light, drought stress and others. Auxin is a good candidate for one of these Ca2+-activating signals. However, the role of auxin-induced Ca2+ signaling is poorly understood. Here, we will provide an overview of possible developmental and physiological roles, as well as mechanisms underlying the interconnection of Ca2+ and auxin signaling.
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- 2013
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171. Beyond dead trees: integrating the scientific process in the Biodiversity Data Journal
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Vincent Smith, Teodor Georgiev, Pavel Stoev, Jordan Biserkov, Jeremy Miller, Laurence Livermore, Edward Baker, Daniel Mietchen, Thomas Couvreur, Gregory Mueller, Torsten Dikow, Kristofer M. Helgen, Jiři Frank, Donat Agosti, David Roberts, and Lyubomir Penev
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Biology (General) ,QH301-705.5 - Published
- 2013
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172. Evaluating the parameters of a mobile maize dryer in practice
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Josef Los, Jiří Fryč, and Zdeněk Konrád
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drying ,maize ,quality ,energy intensiveness ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
The method of drying maize for grain has been recently employed on a large scale in the Czech Republic not only thanks to new maize hybrids but also thanks to the existence of new models of drying plants. One of the new post-harvest lines is a plant in Lipoltice (mobile dryer installed in 2010, storage base in 2012) where basic operational measurements were made of the energy intensiveness of drying and operating parameters of the maize dryer were evaluated. The process of maize drying had two stages, i.e. pre-drying from the initial average grain humidity of 28.55% to 19.6% in the first stage, and the additional drying from 16.7% to a final storage grain humidity of 13.7%. Mean volumes of natural gas consumed per 1 t% for drying in the first and second stage amounted to 1.275 m3 and 1.56 m3, respectively. The total mean consumption of electric energy per 1 t% was calculated to be 1.372 kWh for the given configuration of the post-harvest line.
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- 2013
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173. Modelling the moisture sorption isotherms of Roselle (Hibiscus sabdariffa L.) in the temperature range of 5–35 °C
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Jitka Langová, Donludee Jaisut, Ratiya Thuwapanichayanan, Charotorn Phowong, Jiří Štencl, Danijela Jovanovic, Jiří Fryč, and Václav Vlášek
- Subjects
water activity ,equilibrium moisture content ,hysteresis ,prediction ,grow of microorganisms ,glass transition ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
Water sorption tests of Roselle (Hibiscus sabdariffa L.) carried out under laboratory conditions are presented together with mathematical analyses of the moisture sorption isotherms (MSI’s). Moisture equilibrium data for adsorption and desorption of water from Roselle powder were investigated at near ambient air temperatures in the range of 5 and 35 °C and water activity (Aw) ranging from 0.11 to 0.97. The manometric method has been used for water sorption tests. Models for MSI’s are exponential equations. Coefficients of determination are 0.998 and 0.996 (for adsorption and desorption at 5 °C, respectively), 0.998 and 0.999 (for adsorption and desorption at 20 °C, respectively), and 0.998 and 0.999 (for adsorption and desorption at 35 °C, respectively). The equilibrium moisture content (EMC) of Roselle samples increased with an increase of Aw at a constant temperature both for adsorption and desorption. Adsorption curve equates to desorption curve at higher temperatures of tests carried out. Critical values of EMC of samples tested corresponding to the Aw equal to 0.6 were between 13.401% moisture content wet basis (MC w.b.) and 15.934% MC (w.b.) for moisture adsorption and desorption, respectively. These values are useful for storing conditions optimisation from point of view microorganisms grow and structural changes analyses. Crystal structure changes were observed during adsorption and desorption in the microscope, too. It was found out glass transition in dependence on the water content of samples tested.
- Published
- 2013
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174. Analysis of sound data streamed over the network
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Jiří Fejfar, Jiří Šťastný, Martin Pokorný, Jiří Balej, and Petr Zach
- Subjects
Dynamic Time Warping ,sound signal processing ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
In this paper we inspect a difference between original sound recording and signal captured after streaming this original recording over a network loaded with a heavy traffic. There are several kinds of failures occurring in the captured recording caused by network congestion. We try to find a method how to evaluate correctness of streamed audio. Usually there are metrics based on a human perception of a signal such as “signal is clear, without audible failures”, “signal is having some failures but it is understandable”, or “signal is inarticulate”. These approaches need to be statistically evaluated on a broad set of respondents, which is time and resource consuming. We try to propose some metrics based on signal properties allowing us to compare the original and captured recording. We use algorithm called Dynamic Time Warping (Müller, 2007) commonly used for time series comparison in this paper. Some other time series exploration approaches can be found in (Fejfar, 2011) and (Fejfar, 2012). The data was acquired in our network laboratory simulating network traffic by downloading files, streaming audio and video simultaneously. Our former experiment inspected Quality of Service (QoS) and its impact on failures of received audio data stream. This experiment is focused on the comparison of sound recordings rather than network mechanism.We focus, in this paper, on a real time audio stream such as a telephone call, where it is not possible to stream audio in advance to a “pool”. Instead it is necessary to achieve as small delay as possible (between speaker voice recording and listener voice replay). We are using RTP protocol for streaming audio.
- Published
- 2013
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175. Current state of the employee performance appraisal system in agricultural organizations in the Czech Republic
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Kateřina Venclová, Martina Königová, and Jiří Fejfar
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agriculture ,agricultural organizations ,employee performance appraisal ,human resources ,performance ,survey ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
Employee performance appraisal is one of the most important human resource management tools. The first part of the article concentrates on the theoretical background. The second part evaluates the results of the quantitative survey. The aim of the article is to evaluate the use of formal appraisal of employees in agricultural organizations in the Czech Republic and to test dependencies between selected qualitative characteristics. The results of the survey show that only 12.3% of agricultural organizations (n = 332) use formal appraisal of employees. They also confirm that the application of the formal appraisal of employees in agricultural organizations depends on the size of the agricultural organization (p-value 0.006, Phi coefficient 0.151) and the existence of a personnel department (p-value 0.000, Phi coefficient 0.210). 49.1% of agricultural organizations did not consider formal appraisal important. Only 5.8% of agricultural organizations that do not use any system of formal employee performance appraisal plan its implementation, despite the fact that currently people are considered to be the most important strategic asset of any organization for achieving a competitive advantage.
- Published
- 2013
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176. Will we think in programming languages?
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Jiří Fišer
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Programming languages ,Domain-specific languages ,Metaprogramming ,Python ,F# ,Boo ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Modern science commonly uses computer modelling. Thousands of scientific model are daily transformed to computers programs and tested. The transformation must overcome the gap between abstract human formal notation and low level semantics of contemporary programming languages. The simultaneous knowledge of specific scientific models and programming languages is an unpleasant necessity for a significant proportion of scientists and practitioners (engineers, economist, etc.). But a solution exists — accommodation of programming languages to mental models of their users. The article discuss one partial solution — implementation of domain specific languages in the heart of existing universal languages by mechanisms of metaprogramming. This mechanism overcomes limitations of classical programming languages and complexity of creation new languages from scratch. However, the support of metaprogramming in contemporary languages is limited to isolated and peripheral constructs in very few languages. These constructs are demonstrated by simplified but real examples (metaobject system of Python, monads in F# and macro-based metaprogramming of Boo language) together with discussion of their advantages and disadvantages. The discussion of examples is aimed to finding requirements for new languages and their implementation in a original (parent) language.
- Published
- 2012
177. High-throughput non-destructive phenotyping of traits that contribute to salinity tolerance in Arabidopsis thaliana
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Mariam Awlia, Arianna Nigro, Jiri Fajkus, Sandra Schmockel, Sonia Negrao, Diana Santelia, Martin Trtilek, Mark Tester, Magdalena Maria Julkowska, and Klara Panzarova
- Subjects
Arabidopsis thaliana ,salt stress ,high-throughput phenotyping ,Color segmentation ,shoot-ion independent tolerance ,kinetic chlorophyll fluorescence imaging ,Plant culture ,SB1-1110 - Abstract
Reproducible and efficient high-throughput phenotyping approaches, combined with advances in genome sequencing, are facilitating the discovery of genes affecting plant performance. Salinity tolerance is a desirable trait that can be achieved through breeding, where most have aimed at selecting for plants that perform effective ion exclusion from the shoots. To determine overall plant performance under salt stress, it is helpful to investigate several plant traits collectively in one experimental setup. Hence, we developed a quantitative phenotyping protocol using a high-throughput phenotyping system, with RGB and chlorophyll fluorescence imaging, which captures the growth, morphology, color and photosynthetic performance of Arabidopsis thaliana plants in response to salt stress. We optimized our salt treatment by controlling the soil-water content prior to introducing salt stress. We investigated these traits over time in two accessions in soil at 150, 100 or 50 mM NaCl to find that the plants subjected to 100 mM NaCl showed the most prominent responses in the absence of symptoms of severe stress. In these plants, salt stress induced significant changes in rosette area and morphology, but less prominent changes in rosette coloring and photosystem II efficiency. Clustering of chlorophyll fluorescence traits with plant growth of nine accessions maintained at 100 mM NaCl revealed that in the early stage of salt stress, salinity tolerance correlated with non-photochemical quenching processes and during the later stage, plant performance correlated with quantum yield. This integrative approach allows the simultaneous analysis of several phenotypic traits. In combination with various genetic resources, the phenotyping protocol described here is expected to increase our understanding of plant performance and stress responses, ultimately identifying genes that improve plant performance in salt stress conditions.
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- 2016
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178. TIR1/AFB-Aux/IAA auxin perception mediates rapid cell wall acidification and growth of Arabidopsis hypocotyls
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Matyáš Fendrych, Jeffrey Leung, and Jiří Friml
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auxin ,growth ,cell wall ,hypocotyl ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Despite being composed of immobile cells, plants reorient along directional stimuli. The hormone auxin is redistributed in stimulated organs leading to differential growth and bending. Auxin application triggers rapid cell wall acidification and elongation of aerial organs of plants, but the molecular players mediating these effects are still controversial. Here we use genetically-encoded pH and auxin signaling sensors, pharmacological and genetic manipulations available for Arabidopsis etiolated hypocotyls to clarify how auxin is perceived and the downstream growth executed. We show that auxin-induced acidification occurs by local activation of H+-ATPases, which in the context of gravity response is restricted to the lower organ side. This auxin-stimulated acidification and growth require TIR1/AFB-Aux/IAA nuclear auxin perception. In addition, auxin-induced gene transcription and specifically SAUR proteins are crucial downstream mediators of this growth. Our study provides strong experimental support for the acid growth theory and clarified the contribution of the upstream auxin perception mechanisms.
- Published
- 2016
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179. Hybrid Sterility Locus on Chromosome X Controls Meiotic Recombination Rate in Mouse.
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Maria Balcova, Barbora Faltusova, Vaclav Gergelits, Tanmoy Bhattacharyya, Ondrej Mihola, Zdenek Trachtulec, Corinna Knopf, Vladana Fotopulosova, Irena Chvatalova, Sona Gregorova, and Jiri Forejt
- Subjects
Genetics ,QH426-470 - Abstract
Meiotic recombination safeguards proper segregation of homologous chromosomes into gametes, affects genetic variation within species, and contributes to meiotic chromosome recognition, pairing and synapsis. The Prdm9 gene has a dual role, it controls meiotic recombination by determining the genomic position of crossover hotspots and, in infertile hybrids of house mouse subspecies Mus m. musculus (Mmm) and Mus m. domesticus (Mmd), it further functions as the major hybrid sterility gene. In the latter role Prdm9 interacts with the hybrid sterility X 2 (Hstx2) genomic locus on Chromosome X (Chr X) by a still unknown mechanism. Here we investigated the meiotic recombination rate at the genome-wide level and its possible relation to hybrid sterility. Using immunofluorescence microscopy we quantified the foci of MLH1 DNA mismatch repair protein, the cytological counterparts of reciprocal crossovers, in a panel of inter-subspecific chromosome substitution strains. Two autosomes, Chr 7 and Chr 11, significantly modified the meiotic recombination rate, yet the strongest modifier, designated meiotic recombination 1, Meir1, emerged in the 4.7 Mb Hstx2 genomic locus on Chr X. The male-limited transgressive effect of Meir1 on recombination rate parallels the male-limited transgressive role of Hstx2 in hybrid male sterility. Thus, both genetic factors, the Prdm9 gene and the Hstx2/Meir1 genomic locus, indicate a link between meiotic recombination and hybrid sterility. A strong female-specific modifier of meiotic recombination rate with the effect opposite to Meir1 was localized on Chr X, distally to Meir1. Mapping Meir1 to a narrow candidate interval on Chr X is an important first step towards positional cloning of the respective gene(s) responsible for variation in the global recombination rate between closely related mouse subspecies.
- Published
- 2016
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180. Strong morphological defects in conditional Arabidopsis abp1 knock-down mutants generated in absence of functional ABP1 protein [version 1; referees: 1 approved, 2 approved with reservations]
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Jaroslav Michalko, Matouš Glanc, Catherine Perrot-Rechenmann, and Jiří Friml
- Subjects
Genomics ,Plant Genetics & Gene Expression ,Medicine ,Science - Abstract
The Auxin Binding Protein 1 (ABP1) is one of the most studied proteins in plants. Since decades ago, it has been the prime receptor candidate for the plant hormone auxin with a plethora of described functions in auxin signaling and development. The developmental importance of ABP1 has recently been questioned by identification of Arabidopsis thaliana abp1 knock-out alleles that show no obvious phenotypes under normal growth conditions. In this study, we examined the contradiction between the normal growth and development of the abp1 knock-outs and the strong morphological defects observed in three different ethanol-inducible abp1 knock-down mutants (abp1-AS, SS12K, SS12S). By analyzing segregating populations of abp1 knock-out vs. abp1 knock-down crosses we show that the strong morphological defects that were believed to be the result of conditional down-regulation of ABP1 can be reproduced also in the absence of the functional ABP1 protein. This data suggests that the phenotypes in abp1 knock-down lines are due to the off-target effects and asks for further reflections on the biological function of ABP1 or alternative explanations for the missing phenotypic defects in the abp1 loss-of-function alleles.
- Published
- 2016
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181. The Contemporary Prospects Of The Text Analysis And Editing Of Silesian Songs By Petr Bezruč
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Michal Kosák and Jiří Flaišman
- Subjects
text analysis ,petr bezruč ,silesian songs ,editorial practice ,censorship ,self censorship ,miroslav červenka ,břetislav štorek ,Literature (General) ,PN1-6790 - Abstract
The authors in their study, which is a kind of introduction to the subject, recap on the current state of knowledge and define the basic editing and text analysis issues of Slezské písne /Silesian Songs/ by Peter Bezruč. They use the actual Bezruč´s text material and confrontation of the edition solutions to date, as established in the works of Oldřich Králík, Viktor Fick, Miroslav Červenka a Břetislav Štork, to come to terms with some aspects of the domestic editorial practice and text analysis tradition. The centre of their attention is how M. Červenka and B. Štorek assess the acts of censorship and self censorship and corruptions in their edition of Silesian Songs (1967), how the original text i.e. the canonical text is established, also the way they verify the applicability of and the method of applying the terms such as historical identity or authorization. What is also commented on is the competitor´s edition of Silesian Songs by O. Králík, V. Fick a G. Palas subtitled Historický vývoj /Historical Development/ (1967). The last but not the least the authors draw attention to the possibilities arising from the wider scope of relevant editions of the collection, which should be the base of a new examination of the text history (stemma). Beside the internationalist text analysis approach to the material, the authors suggest that an approach focusing on the social layers of the text should be used, they outline possibilities arising from the otherwise defined concept of so called external interventions into the text related to censorship and editorial practice.
- Published
- 2012
182. Operating tests analysis of liquid biologically degradable waste processing by anaerobic fermentation
- Author
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Jiří Fryč, Tomáš Vítěz, and Tomáš Lošák
- Subjects
biogas ,anaerobic fermentation ,biologically degradable waste ,biogas station ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
This study concerns the analysis of operating anaerobic fermentation systems of agricultural biogas station and implementing a suitable system enabling the use of liquid biowaste. Based on the comparison of the technological solutions and operating parameters of specific equipment a system enabling the utilisation of biowaste has been designed. The tests made use of liquid substrates commercially offered to biogas station operators. The study evaluates practical measurements at an agricultural biogas station in order to evaluate the biogas production from these substrates and the efficiency of transforming input material to usable energy. The use of such treated substrates for the anaerobic fermentation technology may have a substantial influence on the volume of dosed energy crops. The mixture of input substrates consisting of liquid cattle excrements, silage corn, liquid food-processing waste, animal waste and glycerine water was experimentally validated. This mixture was compared with the operation using liquid cattle excrements and silage corn. It was concluded that the proposed composition of input raw materials makes it possible to increase the production of biogas and el. power. On the other hand, it was identified that the energy content of the input raw materials is not optimally transformed into usable energy. Therefore, the proposed mixture of input materials with biowaste is not recommended for use.
- Published
- 2012
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183. Analysis of production tests in processing the mixture of solid and liquid biologically degradable wastes by anaerobic fermentation
- Author
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Jiří Fryč, Josef Los, and Tomáš Lošák
- Subjects
biogas ,anaerobic fermentation ,biologically degradable waste ,biogas station ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
This study concerns the analysis of operating anaerobic fermentation systems of agricultural biogas station and implementing a suitable system enabling the use of a mixture of solid and liquid biowaste. The tests made use of liquid substrates commercially offered to biogas station operators. The study evaluates practical measurements at an agricultural biogas station in order to evaluate the biogas production from these substrates and the efficiency of transforming input material to usable energy. The use of such treated substrates for the anaerobic fermentation technology may have a substantial influence on the volume of dosed energy crops. The mixture of input substrates consisting of liquid cattle excrements, silage corn, solid and liquid waste from food processing, animal waste and glycerine water was experimentally validated. This mixture was compared with the operation using liquid cattle excrements and silage corn. It was concluded that the proposed composition of input raw materials makes it possible to increase the production of biogas and el. power. On the other hand, it was identified that the energy content of the input raw materials is not optimally transformed into usable energy. This is why the proposed mixture of input materials with biowaste is not recommended for use at the used proportion.
- Published
- 2012
- Full Text
- View/download PDF
184. Time series classification using k-Nearest neighbours, Multilayer Perceptron and Learning Vector Quantization algorithms
- Author
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Jiří Fejfar, Jiří Šťastný, and Miroslav Cepl
- Subjects
classification ,k-Nearest Neighbours ,Multilayer Perceptron ,Learning Vector Quantization ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
We are presenting results comparison of three artificial intelligence algorithms in a classification of time series derived from musical excerpts in this paper. Algorithms were chosen to represent different principles of classification – statistic approach, neural networks and competitive learning. The first algorithm is a classical k-Nearest neighbours algorithm, the second algorithm is Multilayer Perceptron (MPL), an example of artificial neural network and the third one is a Learning Vector Quantization (LVQ) algorithm representing supervised counterpart to unsupervised Self Organizing Map (SOM).After our own former experiments with unlabelled data we moved forward to the data labels utilization, which generally led to a better accuracy of classification results. As we need huge data set of labelled time series (a priori knowledge of correct class which each time series instance belongs to), we used, with a good experience in former studies, musical excerpts as a source of real-world time series. We are using standard deviation of the sound signal as a descriptor of a musical excerpts volume level.We are describing principle of each algorithm as well as its implementation briefly, giving links for further research. Classification results of each algorithm are presented in a confusion matrix showing numbers of misclassifications and allowing to evaluate overall accuracy of the algorithm. Results are compared and particular misclassifications are discussed for each algorithm. Finally the best solution is chosen and further research goals are given.
- Published
- 2012
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185. Beetles (Coleoptera) of selected families of the slopes of Macošská and Vilémovická stráň (Moravský kras Protected landscape area, Czech Republic)
- Author
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Jana Niedobová, Vladimír Hula, Pavla Šťastná, Jan Bezděk, Jiří Foit, and Robert Stejskal
- Subjects
Coleoptera ,Moravský kras PLA ,xerothermic habitats ,faunistics ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
Two xerothermic localities in Moravský kras were investigated from March to November 2008. Altogether 183 species of beetles from 13 families (except Carabidae published separately) were collected in Macošská and Vilémovická stráň slopes using several collecting methods: pitfall traps, sweeping of vegetation and Möricke traps. Both slopes are located in the northern part of the Moravský kras and are influenced by pasture management. Altogether we found 21 species listed under Red list of threatened species in the Czech Republic, it is approximately 11.5% of all collected species. The most important species (two critically endangered – CR: Eumolpus asclepiadeus (Pallas, 1776), Sphaeroderma rubidium (Graëlls, 1853) and six endangered – EN) belong to family Chrysomelidae. Another endangered collected species belong to families Curculionidae and Staphylinidae.
- Published
- 2012
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186. Digestate is equal or a better alternative to mineral fertilization of kohlrabi
- Author
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Tomáš Lošák, Ludmila Musilová, Andrea Zatloukalová, Monika Szostková, Jaroslav Hlušek, Jiří Fryč, Tomáš Vítěz, Martin Haitl, Eduardo von Bennewitz, and Anna Martensson
- Subjects
ascorbic acid ,mineral fertilizers ,mineral nitrogen ,nitrate ,yields ,urea ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
In a one-year vegetation pot experiment, we compared the effect of digestate from a biogas station and mineral fertilisers on yield and quality parameters of kohlrabi, variety Segura F1. Four treatments were used in the trial: 1) untreated control, 2) urea, 3) digestate, 4) urea, triple super phosphate, KCl, MgSO4. The N dose was the same in treatments 2–4, 1.5 g N/pot. In treatment 4 the P, K and Mg doses corresponded to those supplied in the digestate treatment (3). The weight of single kohlrabi bulbs in the unfertilised control was significantly lower (36.2%) than in the urea treatment (100%) and the other fertilised treatments. After application of digestate (treatment 3) and mineral fertilisers (treatment 4), the weight of single bulbs significantly increased by 36.2 and 33.6%, respectively, compared with the urea treatment (2). The content of ascorbic acid did not differ between the fertilised treatments (282–301 mg/kg), but was significantly lower than in the unfertilised control (334 mg/kg). There were significant differences between all fertilised treatments (2, 3, 4) in bulb nitrate content (745, 187, 462 mg NO3−/kg fresh matter, respectively). After digestate application the content decreased significantly, to 187 mg NO3−/kg fresh matter. The soil Nmin content after harvest varied between 4.19–5.79 mg/kg in all fertilised treatments and the N-NH4+ form prevailed over N-NO3− only in the digestate treatment (3.45/2.34 mg/kg). We recommend the use of digestate to kohlrabi as it results in comparable or better yield and qualitative parameters of kohlrabi compared with mineral fertilizers.
- Published
- 2012
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187. Terminal Restriction Fragments (TRF) Method to Analyze Telomere Lengths
- Author
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Miloslava Fojtová, Petr Fajkus, Pavla Polanská, and Jiří Fajkus
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Chromosome ends - telomeres - are a focus of intensive research due to their importance for the maintenance of chromosome stability. Their shortening due to incomplete replication functions as a molecular clock counting the number of cell divisions, and ultimately results in cell-cycle arrest and cellular senescence. Determination of telomere lengths is an essential approach in telomere biology for research and diagnostic applications. Terminal Restriction Fragments (TRF) analysis is the oldest approach to analyze telomere lengths and remains the “gold standard” even in current studies. This technique relies on the fact that repeated minisatellite telomeric units do not contain target sites for restriction enzymes. Consequently, telomeres remain in relatively long fragments (TRF), whereas the genomic DNA is digested into short pieces. Fragments of telomeric DNA are then visualized by hybridization with radioactively labeled telomeric probe. As TRF include besides telomeres also a short region of telomere-associated DNA up to the first restriction site, results are slightly shifted towards higher TRFs values. Therefore, the use of frequent cutters or their mixtures is recommended to minimize this difference. Moreover, by using TRF analysis it is possible to distinguish genuine (terminal) telomeres from interstitial telomeric repeats (ITR) (Richards and Ausubel, 1988). In this approach, BAL31 digestion is first applied on high molecular weight DNA. The enzyme progressively degrades linear DNA from its ends. The degraded DNA is then digested with one or more restriction enzymes and fragments are separated by gel electrophoresis. After blotting, membranes are probed with either a terminal marker sequence or telomeric sequence. Genuine TRF can be distinguished from ITR due to their progressive shortening with increasing BAL31 digestion time, while ITR are BAL31-resistant. The TRF BAL31 digestion pattern at the time zero indicates the approximate telomere lengths (Fajkus et al., 2005).
- Published
- 2015
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188. Torsional Moment Measurement on Bucket Wheel Shaft of Giant Machine
- Author
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Jiří FRIES, František HELEBRANT, and Petr KLOUDA
- Subjects
wheel schaft ,torsional moment ,machine ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Bucket wheel loading at the present time (torsional moment on wheel shaft, peripheral cutting force) is determined from electromotor incoming power or reaction force measured on gearbox hinge. Both methods together are weighted by steel construction absorption of driving units and by inertial forces of motor rotating parts. In the article is described direct method of the torsional moment measurement, which eliminates mentioned unfavourable impacts except absorption of steel construction of bucket wheel itself.
- Published
- 2011
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189. Influence of Machined Material Type to the Surface Roughness When Using Wire Electrical Discharge Machining
- Author
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Ján ŽITŇANSKÝ, Jozef ŽARNOVSKÝ, Róbert DRLIČKA, Miroslav MÜLLER, and Jiří FRIES
- Subjects
material ,surface ,steel ,machining ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
In the manufacturing process of complex components we use unconventional or progressive machining methods which can efficiently and with great precision achieve the desired result. We are talking about electro discharge/erosive machining. From an economic perspective, these technologies are used in manufacturing of high precision and complex parts, where it is necessary to achieve accuracy to the thousandth of a millimetre with the machined surface roughness Ra = 0.1 m. These technologies can be used to machine all conductive materials and materials that are difficult to machine by conventional methods, such as sintered carbide and hardened steel. Most commonly used progressive machining methods are sinker EDM and wire EDM. [2]
- Published
- 2011
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190. Overlapping Length and Lifetime Influence on Load of Simple Over-lapped Adhesive Bond
- Author
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Miroslav MÜLLER, Josef ŽARNOVSKÝ, and Jiří FRIES
- Subjects
adhesive ,material ,lifetime ,bond ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
A production process is various in single industrial branches; it usually has one common element – bonding pieces of material. We can say on the base of the production sphere analysis that simple overlapped adhesive bonds are the most common adhesive bonding technology application. The research publicated in this paper deals with then too. The Influence of an overlap length and lifetime of the adhesive bond were evaluated during the time interval 1000 days. Results set an optimum criterion of the adhesive bond constructional shape i. e. the influence of the overlap length, and unit costs related to acquiring the adhesive
- Published
- 2011
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191. Point irrigation design for experimental field in northern part of Gobi desert in Mongolia
- Author
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Pavel SPITZ, Jiří FILIP, and Milada ŠŤASTNÁ
- Subjects
bilateral project ,desert ,discharge distribution uniformity ,excel ,hybozam ,hydraulics ,pc program ,subsurface point irrigation ,surface point irrigation ,underground water ,Agriculture - Abstract
The present paper focuses on the point irrigation design for crops and growing vegetables on an experimental area 2432 m2 at Buchel locality, Northern part of Gobi desert in Mongolia. An underground water source (drill hole - well capacity 2 l/s with water temperature 10°C) and electricity were available in the locality of the selected area of 1 ha and 0.2% grade of slope (no map was available). The design of the surface and subsurface point irrigation for an area of 128 m2 is shown together with a brief description of the hydraulic materials used for the development of the original HYBOZAM program, which was programmed in Microsoft Excel editor, especially to design the pipe dimensions of the point irrigation. A combination of two plastic pipes (with diameters 35.4/40 mm and 28.2/32 mm and 20 m lengths each) was used to provide suitable irrigation uniformity from the orifices on the laterals. HYBOZAM program provides a visual evaluation of the discharge distribution uniformity from the orifices on the laterals by its graphical output. An example of Z1 lateral for surface point irrigation (variant 2) is presented. The final result of the design calculation is given in the table presenting the most important outputs, including statistic evaluation of the discharge distribution uniformity. A table is presented for surface point irrigation - variant 2. From the table is it clear that hydraulic requirements as well as discharge distribution uniformity from the orifices on the laterals have been fulfilled.
- Published
- 2011
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192. Cholesterol esterification and atherogenic index of plasma correlate with lipoprotein size and findings on coronary angiography
- Author
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Milada Dobiášová, Jiri Frohlich, Michaela Šedová, Marian C. Cheung, and B. Greg Brown
- Subjects
fractional esterification rate (FER HDL) ,log (TG/HDL-cholesterol) ,AIP ,biomarkers of cardiovascular risk ,lipoprotein particle size ,HDL-Atherosclerosis Treatment Study (HATS) ,Biochemistry ,QD415-436 - Abstract
We examined the association between rate of cholesterol esterification in plasma depleted of apolipoprotein B-containing lipoproteins (FERHDL), atherogenic index of plasma (AIP) [(log (TG/HDL-C)], concentrations, and size of lipoproteins and changes in coronary artery stenosis in participants in the HDL-Atherosclerosis Treatment Study. A total of 160 patients was treated with simvastatin (S), niacin (N), antioxidants (A) and placebo (P) in four regimens. FERHDL was measured using a radioassay; the size and concentration of lipoprotein subclasses were determined by nuclear magnetic resonance spectroscopy. The S+N and S+N+A therapy decreased AIP and FERHDL, reduced total VLDL (mostly the large and medium size particles), decreased total LDL particles (mostly the small size), and increased total HDL particles (mostly the large size). FERHDL and AIP correlated negatively with particle sizes of HDL and LDL, positively with VLDL particle size, and closely with each other (r = 0.729). Changes in the proportions of small and large lipoprotein particles, which were reflected by FERHDL and AIP, corresponded with findings on coronary angiography. Logistic regression analysis of the changes in the coronary stenosis showed that probability of progression was best explained by FERHDL (P = 0.005). FERHDL and AIP reflect the actual composition of the lipoprotein spectrum and thus predict both the cardiovascular risk and effectiveness of therapy. AIP is already available for use in clinical practice as it can be readily calculated from the routine lipid profile.
- Published
- 2011
- Full Text
- View/download PDF
193. Time series clustering in large data sets
- Author
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Jiří Fejfar and Jiří Šťastný
- Subjects
time series ,self-organizing map ,clustering ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
The clustering of time series is a widely researched area. There are many methods for dealing with this task. We are actually using the Self-organizing map (SOM) with the unsupervised learning algorithm for clustering of time series. After the first experiment (Fejfar, Weinlichová, Šťastný, 2009) it seems that the whole concept of the clustering algorithm is correct but that we have to perform time series clustering on much larger dataset to obtain more accurate results and to find the correlation between configured parameters and results more precisely. The second requirement arose in a need for a well-defined evaluation of results. It seems useful to use sound recordings as instances of time series again. There are many recordings to use in digital libraries, many interesting features and patterns can be found in this area. We are searching for recordings with the similar development of information density in this experiment. It can be used for musical form investigation, cover songs detection and many others applications.The objective of the presented paper is to compare clustering results made with different parameters of feature vectors and the SOM itself. We are describing time series in a simplistic way evaluating standard deviations for separated parts of recordings. The resulting feature vectors are clustered with the SOM in batch training mode with different topologies varying from few neurons to large maps.There are other algorithms discussed, usable for finding similarities between time series and finally conclusions for further research are presented. We also present an overview of the related actual literature and projects.
- Published
- 2011
- Full Text
- View/download PDF
194. Usage and support of geoinformation technologies in analysing the potential of compostable biomass in the Czech Republic
- Author
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Jiří Fryč and Rudolf Rybář
- Subjects
Agriculture ,Biology (General) ,QH301-705.5 - Abstract
In the current society there is more and more effort to introduce, to make use of, and also to develop different information systems (IS). Nowadays it is already impossible to work without support of these systems for most institution of administration, private companies and single businessmen – if they want to be successful in their activities. So implementing and using of this IS become matter of fact. Waste management is one of sections, where these technologies are starting to influence as well. There is a development and implementation of the first IS in the level of single waste generators, regions and national administration as well. It happens to gradual data standardization presently because of unification and compatibility of single systems at all levels. The same situation is in section of Geographic information systems (GIS) as a one of parts of IS-subgroup. First nationwide projects, which can be also used in waste management, are starting to rise in GIS. Also this work is example of connection of GIS with one of waste management section – composting – and it shows possible practical usage on concrete examples.
- Published
- 2011
- Full Text
- View/download PDF
195. Comparison of the effectiveness of digestate and mineral fertilisers on yields and quality of kohlrabi (Brassica oleracea, L.)
- Author
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Tomáš Lošák, Andrea Zatloukalová, Monika Szostková, Jaroslav Hlušek, Jiří Fryč, and Tomáš Vítěz
- Subjects
digestate ,urea ,mineral fertilisers ,kohlrabi ,yields ,ascorbic acid ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
In a one-year vegetation pot experiment we compared the effect of the digestate from a biogas station and mineral fertilisers on yield and quality parameters of kohlrabi, variety Seguza. Four treatments were used in the trial: 1) untreated control, 2) urea, 3) digestate, 4) urea, triple super phosphate, KCl, MgSO4. The rate of N was the same in treatments 2–4, 1.5 g N/pot. In treatment 4 the rate of P, K and Mg corresponded with the rate of these nutrients in the digestate treatment (3). The weight of single bulbs of the control unfertilised treatment were significantly the lowest (22.9%), as well as the nitrate (6.0%) and ascorbic acid content (66.2%) compared to the urea treatment (100%) and the other fertilised treatments. After the application of the digestate (treatment 3) and mineral fertilisers (treatment 4) the weight of single bulbs significantly increased by 27.9 and 29.2%, respectively, compared to the urea treatment (2). The content of ascorbic acid in the fertilised treatments did not differ (772–789 mg/kg) but it increased significantly compared to the unfertilised treatment (511 mg/kg). There were no significant differences between the two treatments fertilised with mineral fertilisers in the bulb nitrate content (678 and 641 mg NO3−/kg fresh matter, respectively). After digestate application their contents decreased significantly to 228 mg NO3−/kg fresh matter. Digestate treatment resulted in comparable or better yield and qualitative parameters compared to treatment with mineral fertilisers.
- Published
- 2011
- Full Text
- View/download PDF
196. Managerial decision making - importance of intuition in the rational process
- Author
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Ivana TICHÁ, Jan HRON, and Jiří FIEDLER
- Subjects
decision making ,intuition ,survey ,comparison ,Agriculture - Abstract
The article contributes to the debate over the use of intuition in the managerial decision making. A brief overview of the debate is further elaborated with the comparison of findings brought about by two surveys conducted in the field settings. The comparison shows some similarities - for instance, the number of respondents admitting their reliance on intuition in decision making, but also some major differences.
- Published
- 2010
- Full Text
- View/download PDF
197. Analysis of the composition and formation of biogas produced during the processing of biological waste by anaerobic digestion technologies
- Author
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Lubomír Hnilica, Jiří Fryč, and Bořivoj Groda
- Subjects
biogas ,anaerobic decomposition ,biological waste ,treatment and utilization of waste ,anaerobic digestive systems ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
This work compares the operating system of anaerobic fermentation of agricultural biogas plants with realization using biowaste. It deals with the operation system of anaerobic fermentation of agricultural biogas plants and implement an appropriate system to enable the use of biowaste. Based on the comparison of technological solutions and operational parameters of specific sites has been designed to allow the system biowaste were made a practical experiment to verify the assumption of increased biogas production. In experiments used substrates, which are industrially produced from the available bio-wastes, treated and then provide to operator of biogas plants. The work was carried out practical measurements to verify the production of biogas from different substrates. Utilize of nominal electric power using biowaste amounted up to 97.66%. Processing of such modified substrates in anaerobic digestion technology can greatly affect the amount of energy crops. Benefit of waste is governed primarily by such projects, where is the problem of ensuring sufficient energy crops. The proposed composition of raw materials also allows the implementation of the existing operation of anaerobic digestion. Operational data on real operations demonstrate the real possibility of further development of the area and secondly the use of biogas plants as well as in the preparation of suitably prepared substrates for the operators. The entire data set underwent a complete statistical analysis. Differences between variants were statistically significant.
- Published
- 2010
- Full Text
- View/download PDF
198. Usage of self-organizing neural networks in evaluation of consumer behaviour
- Author
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Jana Weinlichová and Jiří Fejfar
- Subjects
behaviour of consumers ,Neural networks ,Kohonen map ,semi-supervised learning ,label propagation ,self-training ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
This article deals with evaluation of consumer data by Artificial Intelligence methods. In methodical part there are described learning algorithms for Kohonen maps on the principle of supervised learning, unsupervised learning and semi-supervised learning. The principles of supervised learning and unsupervised learning are compared. On base of binding conditions of these principles there is pointed out an advantage of semi-supervised learning. Three algorithms are described for the semi-supervised learning: label propagation, self-training and co-training. Especially usage of co-training in Kohonen map learning seems to be promising point of other research. In concrete application of Kohonen neural network on consumer’s expense the unsupervised learning method has been chosen – the self-organization. So the features of data are evaluated by clustering method called Kohonen maps. These input data represents consumer expenses of households in countries of European union and are characterised by 12-dimension vector according to commodity classification. The data are evaluated in several years, so we can see their distribution, similarity or dissimilarity and also their evolution. In the article we discus other usage of this method for this type of data and also comparison of our results with results reached by hierarchical cluster analysis.
- Published
- 2010
- Full Text
- View/download PDF
199. Point irrigation for locality Buchel in the north desert Gobi in Mongolia
- Author
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Pavel Spitz and Jiří Filip
- Subjects
desert ,bilateral project ,surface point irrigation ,subsurface point irrigation ,underground water ,hydraulics ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
The design of point irrigation, created by Filip et al. (2007), was worked up as the bilateral projekt in the frame of abroad developing cooperation between the Czech Republic and Mongolia „Rehabilitation of plant production in semiarid territories of northern Gobi”. The period of project realization are years 2006–2009. The responsible institution for the project is Ministery of Agriculture of the Czech Republic and with the realization of the project was encharged Mendel University of Agriculture and Forestry in Brno. The task was work irrigation design for experimental plants and vegetables on the choosen land in Gobi desert in Mongolia. To disposition was underground water source – bore with capacity about 2 l / s and temperature about 10 °C, electric power and land about area cca 1 ha. The condition was use simple irrigation equipment. The fundamental limitation was impossibility using technically more complex and more sophisticated equipment e.g. drip irrigation. The map was not to the disposition, only a judgment of slope 0,2 % in flat terrain. The technical design of surface and subsurface point irrigation are introduced, shortly described are hydrotechnical basis used to created and described the original PC program HYBOZAM (hydraulics of point irrigation for Mongolia) developed in table editor of Microsoft Excel for pipe dimensions of point irrigation design. Part of the program is also evaluation of the irrigation uniformity from outflows on irrigation line.
- Published
- 2009
- Full Text
- View/download PDF
200. Influence of Electric Discharges on Bearings of Electric Machina
- Author
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Jiri Foldyna, Karel Chmelik, and Stanislav Misak
- Subjects
capacity ,lubricators ,strength. ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Bearing currents are one of cause’s bearings faults. The character of a lubricator belongs to main factor influencing an inception of bearing currents. We have analyzed the electric character variety kind of lubricators; the influence of lubricators on a bearing current was analyzed too. Some results from the mentioned research are introduced within this paper.
- Published
- 2008
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