Tracing Methodology Research Articles

Association Between the Oxytocin Receptor Gene and Amygdalar Volume in Healthy Adults

Recent studies have suggested that oxytocin affects social cognition and behavior mediated by the oxytocin receptor (OXTR) in amygdala in humans as well as in experimental animals. Genetic studies have revealed a link between the OXTR gene and the susceptibility to autism spectrum disorders (ASD), especially in the social dysfunctional feature of ASD. We examined the relationship between amygdala volume measured with manual tracing methodology and seven single nucleotide polymorphisms and one haplotype-block in OXTR, which were previously reported to be associated with ASD, in 208 socially intact Japanese adults with no neuropsychiatric history or current diagnosis. The rs2254298A allele of OXTR was significantly associated with larger bilateral amygdala volume. The rs2254298A allele effect on amygdala volume varied in proportion to the dose of this allele. The larger the number of rs2254298A alleles an individual had, the larger their amygdala volume. Such an association was not observed with hippocampal volume or with global brain volumes, including whole gray, white matter, and cerebrospinal-fluid space. Furthermore, two three-single nucleotide polymorphism haplotypes, including rs2254298G allele, showed significant associations with the smaller bilateral amygdala volume. The present results suggest that OXTR might be associated with the susceptibility to ASD, especially in its aspects of social interaction and communication mediated by a modulation of amygdala development, one of the most distributed brain regions with high density of OXTR. Furthermore, amygdala volume measured with magnetic resonance imaging could be a useful intermediate phenotype to uncover the complex link between OXTR and social dysfunction in ASD.

Reduced Gray Matter Volume of Pars Opercularis Is Associated with Impaired Social Communication in High-Functioning Autism Spectrum Disorders

Recent literature suggests that the inferior frontal gyrus, especially its posterior portion, has an important role in imitation and social reciprocity and in the pathophysiology of their disturbance in autism spectrum disorders (ASD). However, the structural abnormality of this region has not fully been clarified in subjects with ASD. Here we obtained magnetic resonance images from 13 right-handed men with high-functioning ASD (Asperger disorder [n = 10] or autism [n = 3]) and from 11 age-, parental socioeconomic background-, and intelligence quotient-matched right-handed typical men. A reliable manual tracing methodology was employed to measure the gray matter volume of the pars opercularis, corresponding to Brodmann area 44, and the pars triangularis, corresponding to Brodmann area 45. A significant gray matter volume reduction of both the pars opercularis and triangularis was found bilaterally in the subjects with ASD compared with the typical control subjects. The effect size seemed to be larger for pars opercularis (1.25) than for pars triangularis (.90). The reduced volume of right as well as total pars opercularis showed a significant association with the increased severity of social communication problems in the ASD group. The current findings support an important role of pars opercularis, a center of the mirror neuron system, in the pathophysiology of ASD.

Electricity Tracing in Systems With and Without Circulating Flows: Physical Insights and Mathematical Proofs

This paper provides new insights into the electricity tracing methodology, by representing the inverted tracing upstream and downstream distribution matrices in the form of matrix power series and by applying linear algebra analysis. The <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> th matrix power represents the contribution of each node to power flows in the other nodes through paths of length exactly <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> in the digraph of flows. Such a representation proves the link between graph-based and linear equation-based approaches for electricity tracing. It also makes it possible to explain an earlier observation that circulating flows, which result in a cyclic directed graph of flows, can be detected by appearance of elements greater than one on the leading diagonal of the inverted tracing distribution matrices. Most importantly, for the first time a rigorous mathematical proof of the invertibility of the tracing distribution matrices is given, along with a proof of convergence for the matrix power series used in the paper; these proofs also allow an analysis of the conditioning of the tracing distribution matrices. Theoretical results are illustrated throughout using simple network examples.

Reduced gray matter volume of Brodmann’s Area 45 is associated with severe psychotic symptoms in patients with schizophrenia

Previous literature has suggested an important role of inferior frontal gyrus, which mainly consists of Brodmann's Area (BA) 44 and 45, in the pathophysiology of schizophrenia. While recent neuroimaging techniques have revealed differential functional correlates of BA 44 and 45 in healthy individuals, previous studies have not yet separately evaluated the gray matter volume reduction of BA 44 and 45 and their relationships to psychotic symptoms in patients with schizophrenia. In the present study, magnetic resonance images were obtained from 29 right-handed male patients with schizophrenia and from 29 age- and handedness-matched healthy male controls. The reliable manual tracing methodology was employed to measure the gray matter volume of BA 44 and BA 45. The severities of psychotic symptoms were evaluated using the five-factor model of positive and negative syndrome scale in the patient group. A significant gray matter volume reduction of both the BA 44 and BA 45 was found bilaterally in the patients with schizophrenia compared with the healthy controls. Among these inferior frontal sub-regions, reduced volume of right BA 45 revealed the largest effect size. In addition, the reduced volume of BA 45 in left hemisphere showed a significant association with the increased severity of delusional behavior, while the severity of disorganized and positive symptoms were correlated with the bilateral BA 45 volumes in the patient group. The findings support an important role of inferior frontal gyrus in the pathophysiology of schizophrenia. The present study further demonstrated that BA 45 might especially contribute to the production of psychotic symptoms in the patients with schizophrenia.

Dual transneuronal tracing in the rat entorhinal-hippocampal circuit by intracerebral injection of recombinant rabies virus vectors

Dual transneuronal tracing is a novel viral tracing methodology which employs two recombinant viruses, each expressing a different reporter protein. Peripheral injection of recombinant pseudorabies viruses has been used as a powerful method to define neurons that coordinate outputs to various peripheral targets of motor and autonomic systems. Here, we assessed the feasibility of recombinants of rabies virus (RV) vector for dual transneuronal tracing in the central nervous system. First, we examined whether two different RV-vectors can double label cells in vitro, and showed that efficient double labeling can be realized by infecting targeted cells with the two RV-vectors within a short time interval. The potential of dual transneuronal tracing was then examined in vivo in the entorhinal-hippocampal circuit, using the chain of projections from CA3 pyramidal cells to CA1 pyramidal cells and subsequently to entorhinal cortex. Six days after the injection of two RV-vectors into the left and right entorhinal cortex respectively, double-labeled neurons were observed in CA3 bilaterally. Some double-labeled neurons showed a Golgi-like labeling. Dual transneuronal tracing potentially provides a powerful and sensitive method to study issues such as the amount of convergence and divergence within and between circuits in the central nervous system. Using this sensitive technique, we established that single neurons in CA3 are connected to the entorhinal cortex bilaterally with only one synaptic relay.

Poster 41: The Influence of Lesion Tracing Methodology on Subtraction Lesion Analysis: Implications for Establishing Brain-Behavior Relationships After Stroke

Poster 41: The Influence of Lesion Tracing Methodology on Subtraction Lesion Analysis: Implications for Establishing Brain-Behavior Relationships After Stroke

General method for determining the sensor readings of motion measurement systems by using skew-ray tracing method

High-accuracy laser-based optoelectronic motion- and position-measuring systems typically utilize light rays that travel from one optical boundary surface to another to perform motion and/or position measurements. It is not a simple task to accurately determine the equations of these sensor readings in terms of positional/angular motions. This problem is addressed in this paper by application of the analytic skew-ray tracing methodology as computed by the finite-difference methodology. An illustrative example of a motion-measurement system and comparison of the position-sensing detector (PSD) readings are given to validate the proposed methodology. It is shown that the proposed methodology can provide accurate expressions of PSD readings. It is also shown that the performance of a corner-cube retro-reflector is better than a cat's eye retro-reflector in positional/angular motion measurement systems.

Design and analysis of an optoelectronic inclinometer for simultaneous measurement of inclinations along two orthogonal directions

Conventional inclination measurement systems such as precision vials and capacitance measuring systems can measure inclination in only one direction at a time. We present what is believed to be a new optoelectronic system that can measure inclination angles along two orthogonal directions simultaneously by using a simple pendulum, two mirrors, a 2D position-sensing detector (PSD), and a laser diode. The light ray from the laser is projected onto a mirror that is fixed to a pendulum whose relative angle modifies in response to inclination changes of the inclinometer's housing. The light ray reflected by the mirror is sensed by the PSD, after which the signal can be interpreted by a PSD signal processor, recorded, or output to a computer. This study uses skew-ray tracing methodology to obtain implicit nonlinear system equations to model the relations of the relative inclination angles of the various components, PSD position, and world frame. A first-order Taylor series expansion is used to obtain a linear form of the system equations. To validate the proposed methodology, an actual prototype system is built and experimental results show that the performance of this system is excellent.

Test Pattern and Drop Tracing for Nozzle Healthy Diagnostic

The Rayleigh instability dominates the behavior during the ink drop from jetting to forming. This paper developed a drop tracing methodology for observation the printing quality, identified the drop tail and its break-off period, satellite drop creation, drop volume variation, and jetting speed. After standard recovery cleaning process (spitting, suction, wiping, priming, etc.), the drop landing presentation and its remedy were characterized by a group of test patterns, and furthermore, to be analyzed the failure mode of the nozzles. The measurement method integrated the test pattern design, analysis algorithm and stroboscope scheme, it could automatically trace the historical changes of nozzles and the operation deterioration early warning is possible. Compare with some traditional inspection methods, like off-line auto optical inspection, high speed image capture, continuous tape-rolling dot analysis etc., this method can real-time operate and detect nozzle failure, help the operator revise processing procedure on-line.

Absolute measurement of [formula omitted] sources activities in the [formula omitted] cross-section determination—Improvement by simulation

A calibration system composed of a 4 π β - γ gas-flow proportional counter coupled to a pair of NaI(Tl) crystals operating in coincidence was used for absolute measurement of Am 242 g sources activities. The samples were produced by irradiating dried aliquots of 241Am solution with epithermal neutrons in a research reactor. Efficiency tracing methodology using 60Co as tracer was applied. Thick external absorbers were used to change the Am 242 g beta detection efficiency and to avoid counting alpha particles from the dominating activity of 241Am. The resulting complex behavior of the beta detection efficiency curve was simulated by the Monte Carlo method, and the Am 242 g activity was obtained by least-squares method fitting. The activity was determined with an uncertainty of about 1%.

Noise Propagation Issues in Wind Energy Applications

The prediction of noise emitted from operating wind turbines is important to planners in order to avoid the possibility of surpassing the allowable limits close to residential areas. To this end, the wave equation is solved, taking into account the atmospheric and ground characteristics that affect sound propagation. In the present paper, a ray tracing methodology capable of performing axisymmetric calculations of the sound field around an isolated source is used. The methodology simulates all the main physical mechanisms that influence sound propagation and performs calculations for the whole range of acoustic frequencies. In the case of more sources, a quasi-3D calculation is implemented, superposing the contributions from all sources. Application to single wind turbines is validated with available measurements. The effect of various parameters such as ground impedance, temperature, humidity, turbulence, and wind velocity is investigated for an isolated wind turbine as well as for wind parks. It is shown that ground and atmospheric absorption are important at the low and high frequency ranges, respectively. In flat terrain cases, simple propagation models may also give satisfactory predictions of the overall sound pressure levels. However, in complex terrain cases, the wind velocity and the relief of the topography can significantly affect noise propagation, suggesting the necessity for using sophisticated propagation models, such as the current one.

A Methodology for Allocating Transmission Losses Due to Cross-Border Trades

Transmission pricing of cross-border trades is often difficult since individual countries may use incompatible internal transmission pricing regimes, and they are usually unwilling to disclose any sensitive information about their own systems. In this paper, the use of a tracing methodology is proposed to overcome these problems using loss allocation problem as an example. Firstly, a modification of the tracing methodology is presented in which the loss is allocated in a direct way. Then a unifying tracing-based methodology of transmission pricing for cross-border trades is proposed. The only data required are the flows in the tie-lines and the charges to be applied to the border nodes in each country. No information is required about individual transactions, load/generation profiles or internal networks. The methodology is illustrated on the IEEE 118 node network divided into four areas, each with a different internal transmission pricing methodology. The proposed methodology is shown to be simple, transparent and very fast and it can deal effectively with cyclic flows.

Proportional sharing assumption in tracing methodology

In order to overcome problems related to the marginal pricing of transmission costs, tracing methodology has been proposed as an alternative, most notably for transmission pricing of cross-border trades in Europe. The tracing methodology is based on the assumption that, at any network node, the incoming flows are proportionally distributed among the outcoming flows. This assumption can be neither proved nor disproved physically and the authors aim to rationalise it. The analysis presented here is of the loss allocation problem. First it is shown that the proportionality assumption leads to the cost allocation which is aggregation invariant. Then the proportional sharing principle is rationalised using game theory and the information theory. We show that the Shapley value solution concept, which satisfies all properties one may demand of a loss allocation scheme, substantiates the proportional sharing rule. We have also shown that the rule can be derived from the maximum entropy principle.

03/02335 A proposal for annual power fee in Thailand based on electricity tracing methodology: Limpasuwan, T. et al. Electric Power Systems Research, 2003, 64 (3), 219–226

03/02335 A proposal for annual power fee in Thailand based on electricity tracing methodology: Limpasuwan, T. et al. Electric Power Systems Research, 2003, 64 (3), 219–226

A proposal for annual power fee in Thailand based on electricity tracing methodology

It is envisaged that by 2003 electrical energy in Thailand will be freely traded under the new electricity supply industry (ESI) structure. The transmission use of system charge will be based on the short run marginal cost (SRMC). The well-known issue with the SRMC is its inability to recover the embedded cost of the transmission system. To recover such cost, the Electricity Generating Authority of Thailand (EGAT) proposed an annual power fee based on the proportion of generation and demand in each zone. As such fee gives a crude signal towards investment in a particular zone, in this paper application of the electricity tracing methodology has been investigated. Tracing-based fee can be seen as a refinement of the crude fee based on the proportion of zonal generation and demand as it takes into account how the zonal imbalance of generation and demand loads up transmission facilities in other zones. In addition, the paper provides an alternative combined zonal and nodal annual power fee where the nodal component of the annual power fee provides an additional signal towards a balanced location of generation and demand within a zone. Analysis of the results for Thai system has confirmed that the proposed methodology provides intended signals.

The upper inflection point of the pressure-volume curve. Influence of methodology and of different modes of ventilation.

The pressure-volume (P/V) curve has been proposed as a tool to adjust the ventilatory settings in cases of acute respiratory distress syndrome (ARDS). The aim of this study was to test the influence of P/V tracing methodology on the presence and value of the upper inflection point (UIP). In 13 medical ARDS patients, the interruption and the automated low flow inflation methods were compared while the patients were ventilated at conventional (10-12 ml/kg) and at low (5-6 ml/kg) tidal volume (Vt). Two levels of inspiratory flow and insufflation time were used (3 and 6 s). No significant difference in UIP was found between the static and the dynamic methods, whatever the flow used. At Vt 10-12 ml/kg, the static and dynamic UIPs were 22.4 +/- 4.4 cmH(2)O and 22.1 +/- 4.5 cmH(2)O ( p = 0.86), respectively; at Vt of 5-6 ml/kg, the static and dynamic UIPs were 26.6 +/- 4.1 cmH(2)O and 25.5 +/- 5 cmH(2)O ( p = 0.34), respectively. Significant differences in UIP were found, in the static and dynamic conditions, between the two levels of Vt ( p < 0.005): it was lower with the higher Vt, suggesting that UIP is dependent on previous tidal alveolar recruitment. Interruption and continuous flow techniques gave similar results, but the previous Vt influences the pressure value of the UIP.

Tracing Windows95

Most published research on system behavior and workload characterization has been based on either Unix systems or large, usually IBM or IBM-compatible, mainframe systems. It is reasonable to believe that user behavior and workloads are different for PC systems. Further, the aspects of system design most needing study have changed from the mainframes dominant in the 1960s and 1970s, and the Unix systems that became so popular in the 1980s to the PCs that seem to be rapidly taking over many or most aspects of computing. Windows95, along with its very similar successor, Windows98, is currently the most widely used computer operating system. In this paper, we describe our tracer, which runs on Intel Pentium based PCs running the Microsoft Windows95 operating system. Following the discussion of our tracing methodology, Windows95 operating system, and a tracing tool we developed for Windows95, we give some descriptive and statistical results based on the traces collected from 36 PC users.

Detection of fault structure under a near-surface low velocity layer by seismic tomography: synthetics studies

We have developed a new method to detect a fault structure under a near-surface low velocity layer (LVL) by seismic tomography. The field study showed that the tomography image reconstructed using borehole-surface configuration had a different result from that of using a crosshole configuration. The image reconstructed by using a borehole-surface configuration showed a decrease in seismic velocities along boreholes, and also the tomogram result using both configurations can not detect the subsurface fault structure. These phenomena are caused by the low velocity layer (LVL) at the top of investigation area. The basic idea hard is based on a downward continuation principle. By knowing the thickness of the LVL and the top of bedrock enables us to place ‘virtual receiver’ and/or ‘virtual source’ below the LVL. In this way, we can reconstruct the image by various tomographic methodologies. As an advantage, this method is easy to be use with the aid of ray tracing methodology. It can also reduce the effect of the near-surface LVL and can maximize the reconstructed image. The final result of our synthetic images by ILST, SIRT, and modified SIRT shows high accuracy and resolution for detection of fault structure under the low velocity layer.

Verifying software requirements: a requirement tracing methodology and its software tool-RADIX

The waterfall-based software development methodology usually requires significant efforts and lengthy intervals to develop, review, inspect, and test very large and complex real-time software systems. Although the methodology itself is stable and mature, the quality of software products still largely depends on development efforts expended in testing, which is usually very costly and time consuming. The author describes the implementation of an integrated approach of software development, review, inspection, and testing based on well-identified software requirements. Due to the huge size and the complex feature interactions of the 5ESS Switch software, the process of review, inspection, and testing has been very important to the project. To enhance the quality of the products, it is necessary to ensure the feature requirements requested by customers, external and internal, are developed correctly. The requirement traceability procedure described in the paper is a systematic method to assist 5ESS Switch scientists and engineers to achieve the goal. The results of the implementation of the requirement traceability procedure and its RADIX tool are significant. >

Chicken oocyte growth: receptor-mediated yolk deposition

During the rapid final stage of growth, chicken oocytes take up massive amounts of plasma components and convert them to yolk. The oocyte expresses a receptor that binds both major yolk lipoprotein precursors, vitellogenin (VTG) and very low density lipoprotein (VLDL). In the present study, in vivo transport tracing methodology, isolation of coated vesicles, ligand- and immuno-blotting, and ultrastructural immunocytochemistry were used for the analysis of receptor-mediated yolk formation. The VTG/VLDL receptor was identified in coated profiles in the oocyte periphery, in isolated coated vesicles, and within vesicular compartments both outside and inside membrane-bounded yolk storage organelles (yolk spheres). VLDL particles colocalized with the receptor, as demonstrated by ultrastructural visualization of VLDL-gold following intravenous administration, as well as by immunocytochemical analysis with antibodies to VLDL. Lipoprotein particles were shown to reach the oocyte surface by passage across the basement membrane, which possibly plays an active and selective role in yolk precursor accessibility to the oocyte surface, and through gaps between the follicular granulosa cells. Following delivery of ligands from the plasma membrane into yolk spheres, proteolytic processing of VTG and VLDL by cathepsin D appears to correlate with segregation of receptors and ligands which enter disparate sub-compartments within the yolk spheres. In small, quiescent oocytes, the VTG/VLDL receptor was localized to the central portion of the cell. At onset of the rapid growth phase, it appears that this pre-existing pool of receptors redistributes to the peripheral region, thereby initiating yolk formation. Such a redistribution mechanism would obliterate the need for de novo synthesis of receptors when the oocyte's energy expenditure is to be utilized for plasma membrane synthesis, establishment and maintenance of intracellular topography and yolk formation, and preparation for ovulation.