Functional penetration of variability of motor neuron spike timing through a modulated neuromuscular system

Variability of the neuronal spike pattern is usually thought of in terms of the information that the different interspike intervals might be encoding. However, the very presence of the variability can have other kinds of functional significance. Here we consider the example of the B15/B16-ARC neuromuscular system of Aplysia, a model system for the study of neuromuscular modulation and control. We show that variability of motor neuron spike timing at the input to the system penetrates throughout the system, affecting all downstream variables including modulator release, modulator concentrations, modulatory actions, and the contraction of the muscle. Furthermore, not only does the variability penetrate through the system, but it is actually instrumental in maintaining its modulation and contractions at a robust, physiological level.     

Catalytic properties and electronic structure of copper ions in Cu-ZSM-5

The effect of ion exchange conditions, such as Si/Al ratio, precursor copper salt, pH and concentration of the solution, on the catalytic activity in SCR of NO by propane and on the electronic state of copper ions in Cu-ZSM-5 has been studied. The NO conversion in NO SCR by C₃H₈ has been found to reach a maximum value at Cu/Al ratio about 0.37–0.4 and remain constant at higher Cu/Al.

ESR and UV–vis DR spectroscopy have been used to elucidate stabilization conditions of copper ions in Cu-ZSM-5 zeolites as isolated Cu²⁺ ions, chain copper oxide structures and square-plain oxide clusters. The ability of copper ions for reduction and reoxidation in the chain structures may be responsible for the catalytic activity of Cu-ZSM-5. These transformations of copper ions are accompanied by the observation of intervalence transitions Cu²⁺–Cu⁺ and CTLM of the chain structures in the UV–vis spectra.     

Velocity Distribution in the Roughness Layer of Rough-Bed Flows

Several models for the vertical distribution of the double-averaged (in time and in the plane parallel to the mean bed) longitudinal velocity in the flow region between roughness troughs and roughness tops are suggested. We found that the same model for velocity distribution may be applicable to a range of flow conditions and roughness types, which share some common features. The suggested models for velocity distribution in the near-bed region are: (1) Constant velocity; (2) exponential velocity distribution; and (3) linear velocity distribution. The measured velocity distributions may be approximated by a single model or by a combination of models depending on roughness geometry and flow conditions. The validity of these models for velocity distribution is supported by laboratory data.     

Resonance phenomena of π-mode forming in multi-element gratings

An analysis of resonances of scattering from multi-element grating formed by a finite number of resonant elements is presented. It has been shown that gratings with three and more elements on its period can support the π-mode. The π-mode of a grating is characterized by the existence of the regions in the vicinity of the grating and along its period where the electromagnetic field has opposite phases. The existence and excitation of the π-mode in finite gratings with resonant cells formed by several scatterers having open cavities have been studied. The particular case of the grating with cells formed by three identical slotted cylinders has been considered in detail. An application of gratings which support the π-mode in electron-vacuum oscillators of millimeter waves for efficient deceleration of electrons and extracting energy from electron beam is discussed.     

Autodyne Effect in Weak-Resonant BWO with Chaotic Dynamics

An autodyne phenomenon in the O-type Weak-Resonant Backward Wave Oscillator of K _a-band working in chaotic oscillatory regime is under investigation. The main attention is paid to the studying of the action of decorrelated reflected signals on the modulation of the power spectral density of the chaotic oscillations. Physical mechanisms are revealed and phenomenological model is suggested to explain the strong PSD modulation observed under the affect of the small refelected signal. The PSD modulation index has been introduced and its anomalous increase with the enlargement of the distance to the load is revealed experimentally, as well as the physical explanation for that effect is presented. All physical results obtained are valid for the autodyne effect in any chaotic oscillator. The results obtained can be used for the design of different autodyne based devices for the remote sensing, microwave telemetry and control systems.     

Determination of PCBs in fatty tissues by means of several detection techniques

Difficulties with harmonization of analytical procedures and consequently poor comparability of generated data represent in the Czech Republic the main reason for the delay in issuing of updated legislation for polychlorobiphenyls (PCBs) in foodstuffs. This study draws attention to possible errors (overestimations) that can occur during routine determination of these residues in the fat portion of biotic matrices. We demonstrate the gas Chromatographic (GC) conditions under which interfering contaminants such as phthalates and/or chlorinated pesticides can be separated from analytes. Discussion is focused on the advantages and drawbacks of GC with an electron capture detector, GC mass spectrometry and GC with an atomic emission detector. Various approaches used for calculation of PCBs contents are compared.

---

Bestimmung der PCB in Fettgeweben mittels verschiedener Detektionstechniken

Zusammenfassung Das Problem mit der Harmonisierung der analytischen Verfahren und der geringen Vergleichbarkeit der Angaben ist ein Hauptgrund der Verspätung in der neuen Legislative für PCB in Lebensmitteln in der Tschechischen Republik. Die Arbeit beschreibt die möglichen Fehler (Falsch-positive Fehler), die durch die routinierte Bestimmung von PCB-Rückständen in Fettanteilen der biologischen Materialien auftreten können. Es werden die gaschromatographischen Bedingungen beschrieben, unter denen die Interferenzen, wie z. B. Phthalaten und chlorierten Pesticiden, von Stoffen abgetrennt werden können. Die Vorteile und Nachteile der Methoden GC-ECD, GC-MS und GC-AED werden diskutiert. Die verschiedenen für die Kalkulation des PCB-Gehaltes angewendeten Annäherungen werden miteinander verglichen.

     

Integrated Dual-Display-Based 3G Mobile Phone / Wireless Terminal

In this paper, we describe HW and SW features of the developed prototype of a hybrid 3G mobile phone and wireless terminal, which provides integral video projection onto two VGA/2 displays that, when put side-by-side, form the integrated display with the ratio of the overall width to its overall height, equal to 4:3, so providing the integral video VGA format and enabling visual presentation of standard full-size web pages, PC mainstream SW screens (such as e.g. the ones of e-mail clients), multi-media content etc. When not in use, the displays can be fold back one onto each other, so preserving the industry-standard dimensions of the device. The two displays that share the image provide it with overall resolution of 640 x 480 pixels per inch. The device is driven by Texas Instruments OMAP 2420 multimedia processor with ARM1136 core and Linux operating system. In addition, the device is equipped with specially developped prototypes of unique spring/microgenerator-based battery charger as well as with ultra-thin mountable foil-based QWERTY keyboard.     

用于物体探测与统计的电路设计

当物体是规律运动时,对它们作统计很简单,但当物体作振动,或必须手工移动物体时,统计就变得很困难。要解决这个问题,就需要一种可靠而无误差地探测物体的系统。此时,就无法采用光遮断开关、IR光栅,或其它传感器,因为物体穿过某个传感器的次数多于一次。     

Research on orotron oscillator with dispersive open resonant system

Theoretical and experimental results of an investigation into a new resonant system have been obtained. This system is named the sphere-corner-echelette open resonator (SCEOR) due to the employment of a mirror that was formed by two echelettes at the angles of 45° to the resonator axis. It turns ont that this resonator is excited on the specific modes not unique to others oscillating systems. There are presented the results of the experimental research of the orotron oscillator with the SCEOR. The spectrum of this device contains only the fundamental modes such as theT E M ₀₀₆,T E M ₀₀₇,T E M ₀₀₈. The efficiency of the orotron is improved, when all other factors are the same the orotron with a much used sphere-cylindrical open resonator.