Part Of Pole Research Articles

Acoustics and synthesis of nasalization

In this paper acoustics and synthesis of nasalization is studied based on a comprehensive computer model of the vocal tract: TRACTTALK. TRACTTALK simulates the vocal‐tract system in the frequency domain and derives the time‐domain equivalent to produce sound output. It incorporates all important components of the system and decomposes the transfer function into its zero and pole parts. Such a decomposition enables one to accurately estimate poles and zeros of a nasalized sound. First, temporal trajectories of poles/zeros are examined as a function of the velopharyngeal opening, the presence of the nasal sinuses, and other articulatory parameters. This is in follow‐up to previous work [Flanagan, AT&T Bell Labs. internal report (1983)]. The attempt is to systematically characterize the pole/zero pattern of nasalization for improving the performance of formant tracking and feature labeling algorithms. Secondly, synthesis of nasalization is described using TRACTTALK. Listening experiments are conducted to assess the relationships among perceived nasality, inclusion of the nasal sinuses, and the degree of the velopharyngeal opening. It is found, e.g., that inclusion of the nasal sinuses results in stronger perceived nasality. While the literature reports differing views on the role of sinuses in nasality, these results are consistent with the findings of Maeda [Proc. ICASSP 2, 911–914 (1982)]. Synthetic speech generated from the vocal‐tract system will be demonstrated.

The heavy fermion damping rate puzzle

: We examine again the problem of the damping rate of a moving heavy fermion in a hot plasma within the resummed perturbative theory of Pisarski and Braaten. The ansatz for its evaluation which relates it to the imaginary part of the fermion propagator pole in the framework of a self-consistent approach is critically analyzed. As already pointed out by various authors, the only way to define the rate is through additional implementation of magnetic screening. We show in detail how the ansatz works in this case and where we disagree with other authors. We conclude that the self-consistent approach is not satisfactory.

Specificity in the efferent projections of the nucleus accumbens in the rat: Comparison of the rostral pole projection patterns with those of the core and shell

The efferent connections of the rostral pole of the rat accumbens, where distinct core and shell subterritories can not be identified, were examined with the aid of the anterogradely transported plant lectin, Phaseolus vulgaris-leucoagglutinin (PHA-L), for comparison with the previously reported projection patterns of the accumbal core and shell. Injection sites and transported PHA-L were evaluated with the aid of reference to adjacent sections processed to display substance P or calbindin 28 kD immunoreactivities, i.e., markers that demonstrate the core and shell. Lateral parts of the rostral pole gave rise to a "core-like" projection system that involved the rostroventral globus pallidus, subcommissural ventral pallidum, entopeduncular nucleus and an adjacent part of the lateral hypothalamus, lateral ventral tegmental area, dorsal pars compacta, and structures in the lateral mesencephalic tegmentum and central grey. The medial part of the rostral pole gave rise to a "shell-like" innervation of the subcommissural ventral pallidum, lateral preoptic region, lateral hypothalamus, ventral tegmental area, dorsalmost pars compacta, retrorubral field, lateral midbrain tegmentum, and central grey. In contrast to the large numbers of axon varicosities observed through the entire length of lateral hypothalamus following shell injections, dense accumulations of axon collaterals and varicosities in hypothalamus were limited to the levels of origin of the stria medullaris bundle and entopeduncular nucleus and to the posterlateral region following medial injections. The medial part of the rostral pole contributed some projections to preoptic and sublenticular regions, but not to the bed nucleus of the stria terminalis. Noteworthy concentrations of calbindin immunoreactive cells observed in the lateral rostral pole correlate with the origin of the "basal ganglia-like" projection system, provoking the speculation that ventral striatal calbindin immunoreactive cells contribute principally to basal ganglia-like projections while cells lacking calbindin immunoreactivity contribute to the innervation of hypothalamus and midbrain tegmentum.

電子顕微鏡による薄膜磁気ヘッドの磁区観察

A magnetic domain was observed by using an image lock-in technique for backscattered electron contrast (Type II) with a JEOL 2000FX-II 200 kV electron microscope. A thin-film head without a protective layer was excited by applying a 10 mAp-p, 100 kHz drive current. Backscattered electron were synchronously detected by using a diode detector and a look-in amplifier, and images were acquired digitally by using a LINK eXL-II system. Backscattered electrons indicated a difference in the magnetic domain configurations in the upper and lower parts of the upper pole, changing the acceleration voltage. Since the location of a pair of black and white lines in a synchronous mode shows the maximum limit of domain wall movement in one drive current period, the observed difference must have been caused by the difference in domain wall movement, that is, the difference in magnetic flux flow. Conversion of the domain configuration from the upper part to the lower part was also observed. Such conversion is possibly one of the causes of noiseafter-write.

Oscillatory neuronal activity related to visual short-term memory in monkey temporal pole.

The activity of single neurons was recorded extracellularly from the temporal pole of monkeys while they were performing a visual short-term memory task. Neurons in the ventral part of the temporal pole showed sustained firing during the memorization delay period of the task when the monkey was remembering particular visual stimuli. The presence and absence of the firing were correlated with the correct and incorrect performance of the task, respectively. The sustained firing showed oscillation. The data suggest that visual information was stored as sustained firing among certain group of neurons producing oscillations.

Fatal intracranial embolisation of a wilms’ tumour in childhood

Death as a result of tumor embolisation is a rare event in childhood. In almost all reported cases the site of embolisation has been the lungs and in children with Wilms' tumour, emboli have been associated with propagation through the inferior vena cava into the right side of the heart. In paediatric patients with Wilms' tumour intracranial involvement occurring in the absence of lung metastases has only been previously described in infants. In these cases the tumours are assumed to have been present <i>in utero</i> - the pattern of fetal circulation providing an explanation for the distribution of metastases. The case reported demonstrates a rare alternative mechanism for cerebral embolisation in the older child. Case report: An 8-year-old boy with severe mental retardation and cardiac abnormalities, including a ventricular septal defect, presented to the AMCWC with a history of haematuria and weight loss. A Wilms' tumour which had replaced all but part of the lower pole of the right kidney could only be partially resected. Ninety minutes into the operation a transient episode of hypotension was recorded. Post-operatively the patient did not regain consciousness and death occurred 24 hours later. Post-mortem examination showed extensive infarction of the left cerebral hemisphere with tumour emboli in the left internal carotid artery extending into and obstructing the left anterior cerebral and left middle cerebral arteries. This report describes an unusual case of death secondary to intracerebral tumour embolism in which the presence of a ventricular septal defect provided a route for paradoxical embolism of tumour to the internal carotid artery.

Large-Q2 behavior of the Higgs mechanism as derived from one-loop diagrams and the renormalization-group equation.

The renormalization-group (RG) approach generalized by Lee and Weisberger to the case of gauge theories with spontaneous symmetry breaking is adopted in order to study the large-${Q}^{2}$ behavior of the Higgs mechanism. The approach amounts to a generalization of the well-known concept of "running coupling constants" to all the couplings involved in the theory. To simplify our consideration, we have considered scalar electrodynamics (QED) in which a U(1) gauge field interacts with both fermions and scalar fields (the latter responsible for spontaneous symmetry breaking). We first carry out a perturbative calculation including all one-loop diagrams with the explicit results on the various renormalization constants obtained by separating out pole parts ($\ensuremath{\propto}\frac{1}{\ensuremath{\epsilon}}$) of the various diagrams regulated in the dimensional-regularization scheme. Using the explicit results on the renormalization constants, we extract the $\ensuremath{\beta}$ and $\ensuremath{\gamma}$ functions which govern the behavior of the theory through the RG equation as ${Q}^{2}\ensuremath{\rightarrow}\ensuremath{\infty}$. We then solve explicitly the coupled RG equations, obtaining the result that the vacuum expectation value ${v}^{2}({Q}^{2})$ vanishes as ${Q}^{2}\ensuremath{\rightarrow}\ensuremath{\infty}$ (i.e., the broken symmetry is restored) but the gauge sector (consisting of the gauge field and fermions) does not decouple from the strongly self-interacting Higgs sector. In the case of non-Abelian gauge theories, we suggest looking for theories which allow for an eventual decoupling between the strongly interacting Higgs sector and the asymptotically free gauge sector.

Unique oscillatory activity related to visual processing in the temporal pole of monkeys

To examine the role of the temporal pole of monkeys in visual processing, the activity of single neurons was extracellularly recorded while the monkey performed a visual discrimination task. Various colored photographs were used as visual stimuli. We found neurons with oscillatory activity coupled to visual stimuli in the ventral part of the temporal pole. Oscillatory activity tended to be elicited by objects familiar to the monkey, such as familiar human faces, familiar foods and familiar non-food objects related to the experiment. The frequencies of oscillations changed depending upon the nature of the visual stimulus. The results suggest that oscillatory activity generated by the activation of a certain circuit is involved in the recognition of complex visual stimuli, leading to the production of certain psychological states.

Efferent projections of the subthalamic nucleus in the squirrel monkey as studied by the PHA‐L anterograde tracing method

The organization of the efferent connections of the subthalamic nucleus was studied in the squirrel monkey (Saimiri sciureus) by using the lectin Phaseolus vulgaris-leucoagglutinin (PHA-L) as an anterograde tracer. At the level of the basal forebrain, anterogradely labeled fibers and axon terminals were mostly found in the striatopallidal complex and the substantia innominata. In cases in which the PHA-L injection sites were placed in the central or the lateral third of the subthalamic nucleus, numerous anterogradely labeled fibers were seen to arise from the injection loci and innervate massively the globus pallidus. At pallidal levels the fibers formed bands lying parallel and adjacent to the medullary laminae. The number and the complexity of the topographical organization of these bands varied with the size and the location of the PHA-L injection site. When examined at a higher magnification, the bands of subthalamopallidal fibers appeared as rich plexuses of short axon collaterals with small bulbous enlargements that closely surrounded the cell bodies and primary dendrites of pallidal cells. In contrast, PHA-L injection involving the medial tip of the subthalamic nucleus did not produce bandlike fiber patterns in the globus pallidus. Instead, the labeled fibers formed a diffuse plexus occupying the ventral part of the rostral pole of the globus pallidus as well as the subcommissural pallidal region. The substantia innominata contained a moderate number of labeled fibers and axon terminals following injection of PHA-L in the medial tip of the subthalamic nucleus. A small to moderate number of anterogradely labeled fibers were seen in the putamen after all PHA-L injections. These subthalamostriatal fibers were long, linear, and branched infrequently. At midbrain level the substantia nigra contained a significant number of anterogradely labeled fibers and axon terminals following PHA-L injection in the subthalamic nucleus. The subthalamonigral fibers descended along the ventromedial part of the cerebral peduncle and swept laterally to reach their target. Most of these fibers formed small plexuses along the base of the pars reticulata, whereas a few others ascended along the cell columns of the pars compacta that impinged deeply within the pars reticulata. More caudally in the brainstem, a small number of fibers occurred in the area of the pedunculopontine nucleus and in the periaqueductal gray. These findings indicate that besides its well-known connection with the pallidum, the subthalamic nucleus gives rise to widespread projections to other components of the basal ganglia in primates.

ATMOSPHERIC TRANSMISSION IN THE FAR-INFRARED AT THE SOUTH POLE AND ASTRONOMICAL APPLICATIONS

ABSTRACT The combination of low atmospheric water vapor, high altitude, and low temperatures makes the South Pole and other high interior parts of the Antarctic continent particularly suitable locations for certain types of infrared or millimeter-wave astronomy. Information available on the atmospheric column density of water at the South Pole and at Vostok, the Soviet station, are surveyed. To illustrate the usefulness of these areas for infrared astronomy, important astronomical lines in the wavelength region 50 to 200 microns are listed. The atmospheric transmission in this wavelength region is also calculated and plotted for 0.1 mm and 0.3 mm of precipitable water along the line of sight through the atmosphere. Such low values of precipitable water occur frequently enough to allow practical astronomical observations from the ground and, for certain cases, this can provide advantages over observations from high-flying aircraft or satellites.

Taste-responsive neurons and their locations in the solitary nucleus of the hamster

The solitary nucleus ( nucleus tractus solitarii), the first central relay for taste in mammals, was studied anatomically and physiologically in the golden hamster ( Mesocricetus auratus). Activity of neurons to anterior tongue stimulation with sucrose, NaCl and KCl were extracellularly recorded. Electrolytic lesions or horseradish peroxidase deposits allowed subsequent localization of recording sites. Anterior tongue taste-responsive sites were restricted to a very small part of the rostral pole of the solitary nucleus, which is about 3% of the entire nucleus. Sites were confined to the rostral-central and rostral-lateral subdivisions of Whitehead, which contain a number of morphological cell types. Some chemotopic organization was seen with multi-unit recordings, with NaCl-selective sites concentrated rostrally and sucrose- and KCL-selective sites concentrated caudally. Sites with broad sensitivity were distributed throughout the gustatory region. Single neural units showing inhibition to taste stimuli, units highly reactive to all three stimuli, and units with high spontaneous rates were seen in the solitary nucleus, as well as units that responded very selectively and had low spontaneous rates. Single units with similar response profiles to sucrose, NaCl and KCl were not segregated to separate restricted locations within the taste-reactive region; their distributions overlapped. In the hamster, neurons in the anterior tongue taste region of the solitary nucleus process taste quality information in diverse ways. Highly reactive non-specific neurons, neurons that show inhibition, and neurons with high spontaneous rates are more frequently observed in the solitary nucleus than in the afferent input fibers of the chorda tympani nerve. The small region of the rostral pole enclosing taste-responsive neurons is complexly organized in relation to taste quality and contains a number of morphological cell types whose functional role in taste is not yet known.

Comparison among Several Numerical Integration Methods for Kramers-Kronig Transformation

Several numerical integration methods are compared in order to search out the most effective method for the Kramers-Kronig transformation, using the analytical formula of the Kramers-Kronig transformation of a Lorentzian function as a reference. The methods to be compared involve the use of (1) Maclaurin's formula, (2) trapezium formula, (3) Simpson's formula, and (4) successive double Fourier transform methods. It is found that Maclaurin's formula, in which no special approximation is necessary for the pole part of the integration, gives the most accurate results, and also that its computation time is short. Successive Fourier transform is less accurate than the other methods, but it takes the least time when used without zero-filling. These results have important relevance for programs used to obtain optical constant spectra and to analyze spectral data.

Pion-nucleon interaction model for the P 11 and P 33 channels and the unitary three-body calculation of nn scattering

We extend the isobar-dominated model for the πN P 33 channel in such a manner as to incorporate a background (non-pole) interaction. The pion-nucleon potential has two driving terms, a pole part generated by the πNΔ vertex and a background part. The πrN P 11 interaction is constructed in a similar way by including a pole part generated by the πNN vertex and a non-pole part. Motivated by a quark-model picture for baryons, we choose the common cut-off form factor for the πNN and πNΔ vertices. The parameters of the model are determined by the fit to the empirical πN phase shifts. Using this πN interaction model as an input, we calculate nucleon-nucleon elastic-scattering phase parameters based on a unitary, relativistic, pion-exchange model. We find that our model adequately reproduces the 1D 2 phase parameters as well as those of peripheral partial waves. We also find that the longitudinal total cross section difference Δσ L(pp → NNπ) comes closer to the data. We discuss the different choice of the irN relative momentum, the backward pion propagation, and the Pauli-principle violating states for the background P 11 interaction.

Neural inputs into the temporopolar cortex of the rhesus monkey.

Temporopolar cortex (TP) can be subdivided into agranular, dysgranular, and granular components. The telencephalic input into the temporopolar cortex arises from the orbitofrontal and medial frontal regions, modality-specific visual and auditory association areas, paralimbic regions, the piriform olfactory cortex, the hippocampus, the amygdala, the claustrum, and the basal forebrain. Afferents from limbic and paralimbic regions are directed mostly to the agranular and dysgranular sectors of the temporal pole, whereas afferents from isocortical association areas are distributed predominantly within the granular sector. The temporopolar cortex provides a site for the potential convergence of sensory and limbic inputs. Auditory inputs predominate in the dorsolateral part of the temporopolar cortex whereas visual inputs become prominent only in the ventral portions of this region. Olfactory inputs are directed mostly to the medial parts of the temporal pole. These medial parts also receive more extensive projections from the amygdaloid nuclei.

Redistribution of the nuclear mitotic apparatus protein (NuMA) during mitosis and nuclear assembly: Properties of purified NuMA protein

Monoclonal antibodies and human autoimmune sera specific for the nuclear mitotic apparatus protein (NuMA protein) were applied to study the structure of this protein and its intracellular distribution. The NuMA protein was purified using immuno-affinity columns. Studies on this large (250 kD) nuclear protein indicated that it is a highly asymmetric phosphoprotein. It is present in all mammalian cells examined and in those of some non-mammals. Immunofluorescence studies on fixed cells demonstrated that its intracellular distribution is essentially the same in all species at all stages of the cell cycle. Immunoblot (western blot) analysis showed that the size of the NuMA protein varies slightly in different species. At the onset of mitosis the NuMA protein redistributes from the nucleus to two centrosomal structures that later will become part of the mitotic spindle pole. This occurs at the time of nuclear breakdown and eventually leads to an accumulation of the NuMA protein at the polar region of the mitotic spindle. After anaphase the protein redistributes from the spindle polar region into the reforming nucleus and concentrates initially at the site where nuclear lamins and perichomatin have been reported to assemble. Living cells microinjected with fluorescent anti-NuMA antibodies were studied to examine parameters that effect the redistribution of the NuMA protein in vivo. These experiments indicate that microtubule assembly is essential for the NuMA protein to accumulate in the polar region.

Multi three-cluster coupling model of nuclear reactions

Two alternative versions of practicable connected kernel theories of nuclear reactions are proposed. The basic assumption is that the state of a many-body system can be approximated by a superposition of two- and three-cluster states corresponding to various possible reaction processes. The approach is based on the concept of transitions due to particle exchange as in the AmadoLovelace (AL) formalism. All important three-cluster partitions can be incorporated via multichannel couplings in two-cluster subsystems. The simpler of two models, which is called the multi three-cluster coupling (MTCC) model, is a direct extension of the AL formalism. Using the separable representation of two-cluster potentials, the AL type coupled equations among reaction amplitudes are postulated. The MTCC equation is shown to be reduced to the equation with the same structure as the Faddeev equation. Thus, while the MTCC model can treat a much wider class of nuclear reactions than the Faddeev approach, the calculation is no more complicated than that. The basic assumption in this model, as well as in the AL and AGS theories, is shown to contain some degree of inconsistency regarding the treatment of bound state pole parts of interacting pairs. This is remedied in the other model, which we call the multi two- and three-cluster coupling (MTTC) model. This is the most extended MTCC model that is possible within the two- and three-cluster coupling model. In the MTTC treatment, it is shown that sequential (multi-step) transfers can also be accommodated in addition to all various processes that are possible in the MTCC approach.

Positive bare action for φ4 theory in 2, 3, and 4 euclidean dimensions

By adding appropriate auxiliary fields we exhibit a positive definite bare action for φ 4 theory in 2, 3, and 4 dimensions. As the zeta function regulator is removed the auxiliary fields decouple, leaving a perturbation theory identically that of φ 4 theory renormalized by zeta function regularization with minimal prescription for removing pole parts. We expect this method may allow a rigorous, nonperturbative construction of various field theories.

Single sample modal identification of a nonstationary stochastic process

Gauss-Markov processes excited by nonstationary noises are encountered in the modeling of vibrating systems. We prove that the classical instrumental variable method, as well as the Ho-Kalman realization algorithm, for identifying the pole part (modal characteristics) of the model, are consistent when used on a single sample of the (nonstationary) signal.

Thalamic projections of nucleus reticularis thalami of cat: a study using retrograde transport of horseradish peroxidase and fluorescent tracers.

The retrograde transport of horseradish peroxidase (HRP) and fluorescent tracers after injections in various thalamic nuclei was used to investigate the relative density of retrogradely labeled cells in different districts of reticularis thalami (RE) nuclear complex of cat. The RE nucleus was left virtually free of labeling only after injections localized into the anterior nuclear group; in those experiments, heavy retrograde labeling was obtained in mammillary nuclei. The major targets of RE cells proved to be centralis lateralis-paracentralis (CL-PC) and centrum medianum-parafascicularis (CM-PF) intralaminar nuclei. The projections to various intralaminar nuclei mainly arise in the rostral pole and rostrolateral part of RE nucleus and are reciprocal to intralaminar-RE pathways disclosed by Jones ('75). The RE territories labeled following injections in relay and associational nuclei are more restricted and are located contiguously and slightly anteriorly to a given nucleus. There was a very small proportion of doubly labeled RE cells after injections with fluorescent tracers in different nuclei. This was not due to a technical failure since many double-labeled neurons were found in the same material in medial globus pallidum after thalamic and midbrain injections (see companion paper by Parent and Steriade, '84). We conclude that most individual RE axons arborize in only one thalamic nucleus or nuclear group. An additional finding was the existence of intralaminar-to-relay (CL-PC to VA-VL) projections.

Regge poles and optical-potential backward-angle excitation functions

The oscillatory behaviour of the backward-angle excitation functions, for two moderately absorbing optical potentials, is analysed by using the Regge-pole method. It is shown that the maxima appearing in the excitation functions do not arise from the crossing of the half-integer γ-values of the real part of a dominant Regge pole, but they reflect the enhancement of the contribution of different Regge poles at the energies at which the virtual states get out from the pocket of the corresponding effective potentials.