Ordinary Transmission Research Articles

Reduced hippocampal LTP in mice lacking a presynaptic protein: complexin II.

The SNAP receptor (SNARE) complex is a core complex specialized for synaptic vesicle exocytosis, and the binding of SNAPs to the complex is an essential step for neurotransmitter release. Complexin I and II have been identified as SNARE-complex-associated proteins. Importantly, complexins compete with alpha-SNAP for binding to the complex, suggesting that complexins may modulate neurotransmitter release process. To examine this possibility and to understand the physiological function of complexins, we generated complexin II knockout mice. The complexin-II-deficient mice (-/-) were viable and fertile, and appeared normal. Electrophysiological recordings in the mutant hippocampus showed that ordinary synaptic transmission and paired-pulse facilitation, a form of short-term synaptic plasticity, were normal. However, long-term potentiation (LTP) in both CA1 and CA3 regions was impaired, suggesting that complexin II may not be essential for synaptic vesicle exocytosis, but it does have a role in the establishment of hippocampal LTP.

New Experimental Model to Study the Bone Interface of Endosseous Implants

To set up a three-dimensional culture model of endosseous implant material-osteoblast, titanium (Ti) discs were placed onto confluent cellular layers of human fetal osteoblasts that were cultured in calcifying conditions. Follow-up observations of living cells with phase-contrast microscopy and histological observations of the cell-Ti disc interface with ordinary microscopy and transmission electron microscopy were used to monitor and verify the formation of three-dimensional cellular structures at the osteoblast-Ti disc interface. These methods were further used to study osteoblast cell behavior during the early stage of bone healing in this three-dimensional cellular model. The follow-up observation showed that, upon the placement of the Ti disc, cells migrated from the cellular layer and attached to the rim of the disc, forming cell bridges. Cells continued to attach and orient throughout the culture time. A cellular multilayer at the osteoblast-Ti interface was formed, which resulted in the three-dimensional model. Furthermore, transmission electron microscopy observation showed that there was a mineralizing process at the osteoblast-Ti disc interface just like bone, which confirms the reality of this model. Histological observations with conventional microscopy demonstrated the interfacial relation between biomaterial and cells. If osteoblasts were replaced by other types of cells, this model could be used to study the other kinds of interfaces.

Nuclear Resonant Scattering of Ferromagnetic Amorphous Ribbon

We performed 57Fe nuclear forward scattering experiments using a ferromagnetic (Co0.94Fe0.06)74.5Si13.5B12 amorphous ribbon at BL09XU of SPring-8. The observed NFS spectra of the amorphous ribbon show quantum beats that decay faster than the expected from the lifetime. This fast decay is due to the distribution of the hyperfine magnetic fields. Decay rate determined from NFS in the amorphous is about 2.5 times shorter than that of isolated 57Fe nuclei. This value is similar to one expected from the apparent peak width of the ordinary transmission Mössbauer spectra.

Fourier transform infrared linked analysis of conformational changes in annexin V upon membrane binding.

Annexins are ubiquitous cellular proteins of unknown primary function that bind to anionic phospholipid membranes in a calcium-dependent manner. Correlative studies involving X-ray crystallography and electron microscopy suggest that annexins undergo a structural change upon binding to supported lipid monolayer membranes. In this investigation, novel spectroscopic and analytical techniques have been applied to verify and characterize this change. Soluble annexin V was examined with ordinary transmission infrared spectroscopy, while membrane-bound annexin V was examined with both transmission and internal reflection infrared spectroscopy. Spectra were processed by linked analysis, whereby multiple spectra are fit simultaneously with component bands that are constrained to share common fitting parameters. This approach is shown to enhance the sensitivity and accuracy of the bandfitting procedure. Our results are consistent with the general mode of membrane binding inferred from electron microscopy studies, and they provide independent support for the conclusion that annexin V undergoes a conformational change upon binding to lipid monolayer membranes. Most likely, this change involves the formation of new beta structure in which interstrand hydrogen bonds orient parallel to the membrane surface.

Quantitative optical phase microscopy

We present a new method for the extraction of quantitative phase data from microscopic phase samples by use of partially coherent illumination and an ordinary transmission microscope. The technique produces quantitative images of the phase profile of the sample without phase unwrapping. The technique is able to recover phase even in the presence of amplitude modulation, making it significantly more powerful than existing methods of phase microscopy. We demonstrate the technique by providing quantitatively correct phase images of well-characterized test samples and show that the results obtained for more-complex samples correlate with structures observed with Nomarski differential interference contrast techniques.

Low Bit-Rate Image Coding for Facial Movement

A method of low bit-rate facial image coding specifically designed for the use in video telephone is presented. The basic principle for this facial image coding is to exploit the capabilities of 2D image warping techniques to generate the replica of the sender's facial expression merely by deforming a master face image, which is sent once at the beginning of the telephone call. Several parameters that describe facial expressions are monitored at the transmitter at the video frame rate of 30 frames/s, and then transmitted to the receiver using the in-band data channel. Since transmission of actual image data happens once or when another image is required, the bit-rate is much lower that that required by ordinary video image transmission. A fast bilinear mapping method for warped images, a grid mesh set over the facial image, various warping algorithms to realize head movement and facial motions with respect to eyes and mouth are discussed. This paper also compares the presented low bit-rate facial image coding to its competing methods such as MPEG and the method using a 3D facial model.

Phorbol ester effects at hippocampal synapses act independently of the gamma isoform of PKC.

Ca2+/phospholipid-dependent protein kinase has long been thought to play an important role in modulating synaptic efficacy. It has been shown previously that mice lacking the brain-specific gamma subtype of PKC display abnormal long-term potentiation (LTP), whereas ordinary synaptic transmission is unaffected by the mutation. We now examine the effects of phorbol esters, which are nonselective activators of PKC, on synaptic modulation in these mutant mice. In wild-type mice, phorbol esters produce marked enhancement of synaptic transmission that is largely presynaptic in origin, an effect that has been thought to share mechanisms with LTP. In mutant mice, phorbol ester-mediated potentiation is normal despite the absence of the major PKC isoform. As in wild-type mice, this synaptic enhancement is at least partly attributable to presynaptic changes. Our results demonstrate that the gamma isotype of PKC is not essential for phorbol ester-mediated synaptic facilitation, and place limitations on the possible roles of PKC in LTP.

N-methyl- d-aspartate receptor mediated component of field potentials evoked in horizontal pathways of rat motor cortex

To identify potential sites of synaptic modification of intrinsic cortical circuits, the contribution of the N-methyl- d-aspartate type of glutamate receptors to field potentials evoked in horizontal and oblique intracortical pathways was examined in rat motor cortex slice preparations. Presumably monosynaptic, short latency responses with a prominent negativity (−0.4 to −2.0 mV) were recorded in both superficial (across layer III) and deep (across layer V) horizontal pathways at a distance of ≅500 μm lateral to electrical stimulation sites and in the oblique V-III pathway (−0.3 to −1.6mV). Bath application of the N-methyl- d-aspartate receptor antagonist d,l-2-amino-5-phosphonovaleric acid (100 μM) reversibly decreased field potentials. Although decreases were observed in all components of the waveform, the most pronounced effect was on the late phase of the response. d,l-2-Amino-5-phosphonovaleric acid produced on average a 22% decrease in area, 12% in initial slope and 11% in peak amplitude of responses. Combined application of 100 μM d,l-2-amino-5-phosphonovaleric acic and a non- N-methyl- d-aspartate glutamate receptor antagonist, 6-cyano-7-nitro- or 6,7-dinitro-quinoxaline-2,3-dione (10–20 μM), eliminated all but a small, early and presumably non-synaptic response. In 18 of 23 cases, the relative contribution of the d,l-2-amino-5-phosphonovaleric acid-sensitive component was unrelated to field potential magnitude, suggesting that this component is present in all fiber classes. It is concluded that glutamate is the major transmitter of horizontal connections of layers II/III and layer V, as well as in the oblique V-III pathway. While most glutamatergic transmission is relayed by other glutamate receptor subtypes, N-methyl- d-aspartate receptor activation contributes a small but consistent part of ordinary transmission in each of these pathways in vitro. The results further suggest that a potential for N-methyl- d-aspartate receptor-mediated synaptic modification exists in intrinsic horizontal pathways of both superficial and deep layers of rat motor cortex.

Electron Holographic Observation of Thin Biological Filaments

A non-staining bacterial flagellum filament only 24 nm in diameter has been observed clearly by using a phase-shifting electron holographic technique. This method produces a sufficiently high contrast in-focus image that could never be obtained by ordinary transmission electron microscopic (TEM) methods.

The matrical fibrous structure in pleomorphic adenoma of the parotid gland--three dimensional visualization by the freeze-fracture deep-etch replica method

Three dimensional visualization of the matrical fibrous structure of pleomorphic adenomas of the parotid glands was performed by the freeze-fracture, deep-etch replica method(D-E). Three types of fine architecture, two in the myxoid area and one in the chondroid area, which could not be observed by ordinary transmission electron microscopy (TEM), were revealed. In addition, granular connections between the tumor cell membrane and matrical fibers, probably cell surface proteins, were visualized. In the myxoid area, one type of matrix which has a structure that cannot be identified on TEM, D-E demonstrated a uniform fine fibrous network consisting mainly of 7-10 nm diameter filaments and various architectures. These structural components were interlinked in a specific order and formed a basement membrane-like structure which contained the so-called 'hexagon-lattice structure' reported by Sawada. Another type which appears as an irregular spotty structure and a few collagen-bundles on TEM, was revealed by D-E to be composed of a fine fibrous network and collagen-bundles. The collagen-bundles and the network were also interconnected to form a more complicated network. In the chondroid area, the type of matrix appearing as a mottled amorphous area consisting of electron-dense and electron-lucent parts on TEM, was shown by D-E to be composed of mainly collagen-bundles and a less prominent fine fibrous network. As for the cell surface, there were numerous granular structures which were seen to be anchored within the membrane and rigidly connected with 7-10 nm diameter fibrils. However, direct connections between the cell membrane and collagen-bundles were unremarkable. No tumor cell basement membrane was observed. These findings indicate that, in constructing the tumor tissue and maintaining the tumor cells, the matrix could preserve suitable environment for these cells, and that the matrix and tumor cells may influence each other. To date, the matrix of this tumor has been regarded as a relatively uninteresting element. It was thought to lack any apparent structure and have little involvement in tumor biology. We, on the other hand, believe that this tumor matrix is an important component, and that future investigation of this matrix will provide new insights into the study of pleomorphic adenoma.

吸光感度増感型表面プラズモンセンサによる微量溶液中の吸収物質検出

We developed a sensor system to detect contamination in extremely small amount of liquid sample. Detection method is based on absorption measurement using surface plasmon sensor with enhanced absorptionsensitivity. Calculated result shows that the absorption-sensitivity of the sensor is -720 times higher than that of ordinary transmission method and-46 times higher than that of atteunated-total-reflection method. The minimum amount necessary for the absorption measurement is 2.4 pl from the calculation. We suc-cessfully detected methylene blue of 4.5 pg in 30μL water using this system. We expect that this sensor system can also be applied to qualitative analysis of other liquid samples having very small quantity together with reagent.

Performance analysis of wide zone AVI systems

The wide zone AVI system is an automatic vehicle identification system that can cope with more than one vehicle in the detection zone. Such a system includes a possibility of identification failure by the collision of ID packets, in addition to the ordinary transmission failure. A method to remedy this is to transmit the ID packet several times. This paper considers two methods of transmitting the ID packet from each vehicle. In the first, the packet transmission interval follows an exponential distribution, and in the second, a specified number of transmissions are made at random points which are distributed uniformly during the zone pass period. Using approximate analyses of the identification failure probability, the effects of the design parameters on the system performance are examined for each method. As a result, it is shown that the constant number transmission method has a better performance than the exponential transmission interval method, in terms of the probability of identification success, the number of ID packet transmissions, and other aspects.

Qualitative Analysis of Nanogram Samples with Fourier Transform Infrared Transmission Surface Electromagnetic Wave Spectroscopy

The intensity enhancement of infrared spectra with Ag island films in surface electromagnetic wave spectroscopy (SEWS), which is commonly associated with the ATR method, was observed with the use of an ordinary transmission configuration. We refer to this as “transmission SEWS” or “T-SEWS.” With 10 nm Ag, the magnitude of enhancement factor was about 200 for the NO2 symmetric stretching band at 1350 cm−1 with p-nitrobenzoic acid. In order to estimate its effectiveness as a qualitative analytical method, T-SEWS spectra were compared with normal transmission spectra with the use of several samples. The results showed that T-SEWS is useful in detecting and identifying nanogram amounts of substances which do not have reactive functional groups—e.g., triphenyl phosphate (TPP) or polydimethylsiloxane (PDMS), which do not have -COOH, -SO3H, -C=S, etc. A usable spectrum was observed from as little as 25 ng/cm2 of TPP with the use of a standard triglycine sulfate detector without a beam condenser. Combined with microspectroscopy, T-SEWS shows promise for picogram order analysis and chromatographic applications.

Modified TEM-STEM for magnetic imaging

An electron microscope for magnetic imaging (magnetic domain observation) is described. The microscope includes a magnetic-field-free objective lens and a large bulk specimen stage 30 × 50 mm 2 in size. Its resolution as an ordinary transmission electron microscope is 0.7 nm and it has three Lorentz microscopy modes for magnetic imaging: Lorentz TEM (transmission electron microscopy), DPC (differential phase contrast)-STEM (scanning transmission electron microscopy) and Type-2 magnetic contrast SEM (scanning electron microscopy). Resolution of the domain image is 20 nm in the DPC-STEM mode. The minimum magnification for Type-2 SEM is ×5 on a 15×20 mm 2 specimen area. Quantitative measurement of magnetization can be made in DOC and Type-2 imaging because the magnetic contrast is proportional to the magnetic induction.

The study on supported Fe and FeMo hydrotreating catalysts by combining Mössbauer spectroscopy and ordinary γ-ray transmission

From in-situ Mössbauer spectra recorded at room temperature it is concluded that the support material (carbon or alumina) influences the degree of sulfidation of Fe and FeMo hydrotreating catalysts. For the latter a Fe−Mo−S phase is observed. By combining Mössbauer spectroscopy and ordinary γ-ray spectroscopy the sulfur uptake by the catalyst has been studied.

Display of ordinary transmission holograms with a white light source

A method for displaying ordinary transmission holograms with a white light source is described, based on compensating the color dispersion in a broad band of the visible spectrum. Although some degree of image blur remains because of the size of the source, sharp and bright images at 30 cm from the hologram plane have been reconstructed.

Effective transmission of bulk power over short distances with double circuit transmission lines

This paper presents a mathematical analysis appropriate for the calculation of voltage and current in controlled double circuit type transmission lines. The active and reactive power at both ends of the controlled as well as the ordinary transmission lines are computed. The effect of the phase shift between the two voltage systems of the two circuits of the controlled line is considered in the investigation.

Efficient power transmission over short distance using controlled double-circuit lines

Abstract This paper presents a mathematical analysis which facilitates the calculation of voltages and currents in controlled double-circuit type transmission lines. In addition the active and reactive powers at both ends of the controlled as well as the ordinary transmission lines are computed. In the investigation the effect of the phase shift between the two voltage systems of the two circuits of the controlled line is considered.

Signal processing in optothermal spectroscopy

The usefulness of optothermal spectroscopy for quantitative analysis is discussed. It is shown theoretically and experimentally that optothermal spectroscopy is comparable to ordinary transmission spectroscopy for the determination of optical absorption coefficients.

Power transmission through ring transmission systems

Abstract Now that large blocks of power need to be transmitted to load centers, modifications to traditional transmission systems may be necessary. Although multi-phase (six-phase) systems have been suggested, new connections between the phases of double-circuit transmission lines might improve the transmission performance. This paper presents a mathematical analysis of the main parameters of multi-phase transmission lines. The mutual effect between the phase voltages is included. A ring-type transmission system is proposed for power transmission over lines of a network. Different configurations for such ring systems are investigated. The best connection diagram for this type of transmission is determined according to the condition of maximum transmitted power. The voltage distribution in ring transmission systems is compared with that of ordinary double-circuit transmission lines. The currents through both ring and ordinary lines are estimated. The circulating power during the no-load operation of ring transmission systems is evaluated. The transmitted power over both ordinary and ring double-circuit transmission lines is formulated and computed. Also, the transmission efficiency is calculated with respect to the transmission distance. The performance of ring transmission systems varies according to the angle between the voltages of both phases of the two circuits of double-circuit lines. Abnormal conditions are compared for three types of power transmission, namely, single, double and ring transmission lines. The proposed ring transmission system is recommended for networks with bad stability characteristics.