39 research outputs found
K vývoji a proměnám časopisu Pedagogická orientace v letech 1991–2004
K vývoji a proměnám časopisu Pedagogická orientace v letech 1991–200
The lattice of quasivarietes of modules over a Dedekind ring
In 1995 D. V. Belkin described the lattice of quasivarieties of modules over principal ideal domains [1]. The following paper provides a description of the lattice of subquasivarieties of the variety of modules over a given Dedekind ring. It also shows which subvarieties of these modules are deductive (a variety is deductive if every subquasivariety is a variety)
Metabolomic and transcriptomic data on major metabolic/biosynthetic pathways in workers and soldiers of the termite Prorhinotermes simplex (Isoptera: Rhinotermitidae) and chemical synthesis of intermediates of defensive (E)-nitropentadec-1-ene biosynthesis
Production of nitro compounds has only seldom been recorded in arthropods. The aliphatic nitroalkene (E)-nitropentadec-1-ene (NPD), identified in soldiers of the termite genus Prorhinotermes, was the first case documented in insects in early seventies. Yet, the biosynthetic origin of NPD has long remained unknown. We previously proposed that NPD arises through the condensation of amino acids glycine and/or l-serine with tetradecanoic acid along a biosynthetic pathway analogous to the formation of sphingolipids. Here, we provide a metabolomics and transcriptomic data of the Prorhinotermes simplex termite workers and soldiers. Data are related to NPD biosynthesis in P. simplex soldiers. Original metabolomics data were deposited in MetaboLights metabolomics database and are become publicly available after publishing the original article. Additionally, chemical synthesis of biosynthetic intermediates of NPD in nonlabeled and stable labeled forms are reported. Data extend our poor knowledge of arthropod metabolome and transcriptome and would be useful for comparative study in termites or other arthropods. The data were used for de-replication of NPD biosynthesis and published separately (Jirošová et al., 2017) [1]
Changes in communities of soil dwelling Coleoptera during secondary succession on abandoned fields a preliminary report
Summary
Oscillatory network activity arises from interactions between synaptic and intrinsic membrane properties of neurons. In this review, we summarize general mechanisms of synchronous neuronal oscillations. In addition, we focus on recent experimental and computational studies which suggest that activity-dependent changes of ionic environment can affect both the synaptic and intrinsic neuronal properties and influence the network behavior. GABAA receptor (GABAAR)mediated signaling, that is based on Cl – and HCO3 – permeability, is thought to be important for the oscillogenesis and synchronization in cortical networks. A remarkable feature of GABAergic synapses is that prolonged GABAAR activation may lead to switching from a hyperpolarizing to a depolarizing response. This is partly due to a positive shift of the GABAAR reversal potential (EGABA) that is generated by GABA-induced Cl – accumulation in neurons. Recent studies suggest that activity-dependent EGABA changes may have important implications for the mechanisms of gamma oscillations and seizure-like discharges. Thus, a better understanding of the impact of intracellular Cl – dynamics on network behavior may provide insights into the mechanisms of physiological and pathological brain rhythms. Combination of experiments and simulations is a promising approach for elucidating which properties of the timevarying ionic environment can shape the dynamics of a given circuit. Key words Neuronal oscillations • Synchrony • GABAergic transmission • Computational model • HCO3 – permeability • Cl- accumulation • Intrinsic current
Feedback Control of Laser Welding Based on Frequency Analysis of Light Emissions and Adaptive Beam Shaping
AbstractThis paper presents a novel method for optimization and feedback control of laser welding process. It is based on frequency analysis of the light emitted during the process and adaptive shaping of the laser beam achieved by an active optical element. Experimentally observed correlations between the focal properties of the laser beam, the weld depth and the frequency characteristics of the light emissions, which form the basis of the method, are discussed in detail. The functionality and the high efficiency of the method are demonstrated for a variety of welding parameters settings usually used in industrial practice
Data quality control and tools in passive seismic experiments exemplified on the Czech broadband seismic pool MOBNET in the AlpArray collaborative project
This paper focuses on major issues related to the data
reliability and network performance of 20 broadband (BB) stations of the
Czech (CZ) MOBNET (MOBile NETwork) seismic pool within the AlpArray seismic
experiments. Currently used high-resolution seismological applications
require high-quality data recorded for a sufficiently long time interval at
seismological observatories and during the entire time of operation of the
temporary stations. In this paper we present new hardware and software tools
we have been developing during the last two decades while analysing data from
several international passive experiments. The new tools help to assure the
high-quality standard of broadband seismic data and eliminate potential
errors before supplying data to seismological centres. Special attention is
paid to crucial issues like the detection of sensor misorientation, timing
problems, interchange of record components and/or their polarity reversal,
sensor mass centring, or anomalous channel amplitudes due to, for example,
imperfect gain. Thorough data quality control should represent an integral
constituent of seismic data recording, preprocessing, and archiving,
especially for data from temporary stations in passive seismic experiments.
Large international seismic experiments require enormous efforts from
scientists from different countries and institutions to gather hundreds of
stations to be deployed in the field during a limited time period. In this
paper, we demonstrate the beneficial effects of the procedures we have
developed for acquiring a reliable large set of high-quality data from each
group participating in field experiments. The presented tools can be applied
manually or automatically on data from any seismic network