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At least 541 records · Page 30Linked to original sources
PubMed1983

The totem pole rib graft reconstruction of the nose.

The totem pole rib bone graft for nasal reconstruction is presented as an effective way to prepare the donor bone for the correction of saddle-nose deformity. The article's title emanates from the fact that when the sculpturing of the rib is completed it has the appearance of a totem pole before the separate parts are disarticulated for insertion into the nose. The use of this technique permits an accurate, detailed sculpturing of the component parts of the subsequent reconstruction, permitting correction of each feature of the saddle-nose deformity. If these bony segments were dissected or sculptured separately, the smallness of each part would make it very difficult to carve the precise definition needed for a reconstruction that would give structural support and at the same time afford an aesthetically pleasing result. The rationale of the technique and representative cases are presented.

Adult↗
PubMed1992

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.

Animals↗
PubMed1995

Extreme hypotrophy of the lower body pole, extensive hypoplasia of the spinal column and multiple anomalies of abdominal organs: a maximal variant of the caudal regression sequence?

A newborn with extreme hypotrophy of the lower body pole and aplasia of the lower spinal column is reported. Additional anomalies of internal organs included absence of one kidney and ureter, a diaphragmatic hernia, and anal atresia. Part of the organs located in the lower body pole were necrotic. There were no excretory apertures, and external genitalia were absent. Chromosomal analysis revealed a 46,XY karyotype. The multiple anomalies seen in this newborn may be interpreted as a maximal variant of the caudal regression sequence.

Abnormalities, Multiple↗
PubMed2006

Characterization of neuronopathic Gaucher disease among ethnic Poles.

PURPOSE: Gaucher disease is a common lysosomal storage disease that results from inherited mutations in the gene (GBA) encoding acid beta-glucosidase (GCase). Here, the clinical and molecular findings of the subacute neuronopathic variant are delineated among ethnic Poles. METHODS: Longitudinal studies of visceral, bony, and central nervous system involvement are delineated clinically. Complete gene GBA sequencing was used to characterize the mutations and haplotypes in this population. RESULTS: A greater frequency of subacute neuronopathic Gaucher disease (type 3) is present among ethnic Poles compared with other European countries. Two type 3 phenotypes were found: The first was an early-onset variant with massive visceral disease, progressive kyphoscoliosis, mild cognitive deficits, and survival for three or more decades. This variant resembles the "Norrbottnian" Swedish phenotype. The other variant had more severe progressive central nervous system disease, milder visceral involvement, and absence of kyphoscoliosis. Myoclonus was present in some patients. Neither variant had bone crises and/or pain as major components. The L444P/L444P genotype was most common, but on several different haplotype backgrounds. Other alleles encoded D409H, V305L, and E326K/A446P on various haplotypes. CONCLUSIONS: These studies provide additional expansion of the type 3 genotypes with some commonalities with and differences from other reported variants. Also, such phenotypic expansion should be expected in the other variants of Gaucher disease as the spectrum of ethnic variation becomes more fully delineated.

Adolescent↗
PubMed2005

Posterior pole retinal thickness in ocular hypertension and glaucoma: early changes detected by hemispheric asymmetries.

PURPOSE: To evaluate retinal thickness at the posterior pole of the fundus in ocular hypertension (OHT) and open-angle glaucoma (OAG), and to correlate morphometric findings with visual sensitivity as determined by automated perimetry. METHODS: One randomly selected eye from 41 patients with clinical diagnosis of OHT (n = 25) or early to moderate OAG (n = 16) and 16 age-matched normal controls was examined. Retinal thickness was measured by Retinal Thickness Analyzer (RTA), acquiring 5 pre-defined scans covering the central 20 degrees of the fundus. RTA average thickness and thickness profile data, including hemispheric asymmetries calculated as relative (superior/inferior and nasal/temporal) or absolute (vertical and horizontal, ie, independent of which hemisphere was thinner) parameters, were calculated. For each eye, white-on-white Humphrey 30-2 visual field results were analyzed, in addition to standard global indices, by quantifying perimetric sensitivities for regions of the posterior pole corresponding to those sampled by the RTA. RESULTS: On average, central retinal thickness was reduced (P < 0.05) in OAG compared with OHT or normal control eyes. Vertical hemispheric absolute thickness asymmetry was increased (P < or = 0.01) in OAG eyes compared with the other groups. Horizontal hemispheric absolute thickness asymmetry was increased (P < 0.01) in both OHT and OAG eyes, compared with control eyes. At least one of the RTA parameters was altered in 13 of 25 OHT (52%) and 12 of 16 OAG eyes (75%), most frequently involving thickness asymmetries. In OAG, but not OHT eyes, superior/inferior asymmetry was positively (r = 0.69, P < 0.01) correlated with the corresponding asymmetry in perimetric sensitivity. CONCLUSIONS: The RTA can reveal increased hemispheric thickness asymmetries in both OHT and OAG eyes. In OAG eyes thickness asymmetries are associated with corresponding perimetric asymmetries. The findings in OHT eyes suggest that localized anatomic and functional damage to inner retina may not develop in parallel early in the disease process.

Adult↗
PubMed2001

Avian orientation at steep angles of inclination: experiments with migratory white-crowned sparrows at the magnetic North Pole.

The Earth's magnetic field and celestial cues provide animals with compass information during migration. Inherited magnetic compass courses are selected based on the angle of inclination, making it difficult to orient in the near vertical fields found at high geomagnetic latitudes. Orientation cage experiments were performed at different sites in high Arctic Canada with adult and young white-crowned sparrows (Zonotrichia leucophrys gambelii) in order to investigate birds' ability to use the Earth's magnetic field and celestial cues for orientation in naturally very steep magnetic fields at and close to the magnetic North Pole. Experiments were performed during the natural period of migration at night in the local geomagnetic field under natural clear skies and under simulated total overcast conditions. The experimental birds failed to select a meaningful magnetic compass course under overcast conditions at the magnetic North Pole, but could do so in geomagnetic fields deviating less than 3 degrees from the vertical. Migratory orientation was successful at all sites when celestial cues were available.

Animals↗
PubMed2003

The ch-TOG/XMAP215 protein is essential for spindle pole organization in human somatic cells.

The ch-TOG/XMAP215 family of proteins bind directly to microtubules and appear to play an essential role in stabilizing spindle microtubules. These proteins stabilize microtubules mainly by influencing microtubule plus-end dynamics, yet, in vivo, they are all strongly concentrated at spindle poles, where the minus ends of the microtubules are concentrated. In Drosophila embryos, the centrosomal protein D-TACC is required to efficiently recruit ch-TOG/Msps to centrosomes. In humans, ch-TOG and the three known TACC proteins have been implicated in cancer, but their functions are unknown. Here we extensively depleted TACC3 and ch-TOG from HeLa cells using RNA interference. In TACC3-depleted cells, spindles are well organized, but microtubules are partially destabilized and ch-TOG is no longer concentrated on spindle microtubules. In ch-TOG-depleted cells, relatively robust spindles form, but the spindles are highly disorganized. Thus, in human somatic cells, ch-TOG appears to play a major role in organizing spindle poles, and a more minor role in stabilizing spindle microtubules that is, at least in part, mediated via an interaction with TACC3.

Animals↗
PubMed1993

Spatial and temporal phosphorylation of a transcriptional activator regulates pole-specific gene expression in Caulobacter.

Polar localization of proteins in the Caulobacter predivisional cell results in the formation of two distinct progeny cells, a motile swarmer cell and a sessile stalked cell. The transcription of several flagellar promoters is localized to the swarmer pole of the predivisional cell. We present evidence that the product of the flbD gene is the transcriptional activator of these promoters. We show that FlbD is distributed in all cell types and in both poles of the predivisional cell. We also demonstrate that FlbD can be phosphorylated, and that a FlbD kinase activity is under cell cycle control. Cells expressing a FlbD mutant that should activate transcription in the absence of phosphorylation, exhibited an alteration in the temporal pattern of flagellin transcription. Furthermore, predivisional cells expressing the mutant FlbD failed to polarly localize flagellin synthesis. We propose that the phosphorylation of FlbD is restricted to the swarmer compartment of the predivisional cell, and serves as the control point for regulating the spatial transcription of flagellar promoters.

Amino Acid Sequence↗
PubMed2002

Pole topology of the structure functions of continuous systems.

We develop a theory of the pole topology of the Laplace transform of the structure functions of continuous N component systems based on the Wiener-Hopf technique. We classify systems according to the spectrum of the NxN matrix Q(t), with elements Q(ij)(t)=delta(ij)-2pi square root [rho(i)rho(j)]integrale(-tr)q(ij)(r)dr, associated with their factor functions q(ij)(r). For the simplest nontrivial class of systems--namely, that with only two eigenvalues of Q(t) different from one--a full and explicit analysis of the pole topology is possible. We illustrate the theory with exactly solvable examples, such as the Percus-Yevick equation for arbitrary mixtures of hard spheres (HS) and polydisperse HS and the mean spherical model for binary mixtures of adhesive spheres.

Journal Article↗
PubMed2003

Extension of the pole decomposition for the multidimensional Burgers equation.

It is shown that the generalizations to more than one space dimension of the pole decomposition for the Burgers equation with finite viscosity nu and no force are of the form u=-2nu inverted Delta ln P, where the P's are explicitly known algebraic (or trigonometric) polynomials in the space variables with polynomial (or exponential) dependence on time. Such solutions have pole singularities on the complex algebraic varieties.

Journal Article↗
PubMed2000

Photorefractive response of bulk periodically poled LiNbO3:Y:Fe at high and low spatial frequencies

Polydomain periodically poled samples of iron-doped lithium niobate allow for phase grating recording with the diffraction efficiency close to that ensured by a single-domain sample with identical thickness. At the same time the optical damage induced by a finite transverse size light beam is considerably reduced in the periodically poled sample as compared with single-domain material.

Journal Article↗
PubMed2005

Evidence for the two-pole structure of the lambda(1405) resonance.

The K- p --> pi0pi0sigma0 reaction is studied within a chiral unitary model. The distribution of pi0sigma0 states forming the lambda(1405) shows, in agreement with a recent experiment, a peak at 1420 MeV and a relatively narrow width of gamma = 38 MeV. The mechanism for the reaction is largely dominated by the emission of a pi0 prior to the K- p interaction leading to the lambda(1405). This ensures the coupling of the lambda(1405) to the K- p channel, thus maximizing the contribution of the second state found in chiral unitary theories, which is narrow and of higher energy than the nominal lambda(1405). This is unlike the pi- p --> K0pisigma reaction, which gives more weight to the pole at lower energy and with a larger width. The data of these two experiments, together with the present theoretical analysis, provide firm evidence of the two-pole structure of the lambda(1405).

Journal Article↗
PubMed2001

Structural modification on silica glass surface induced by thermal poling for second harmonic generation.

O-K edge XANES spectroscopy evidences structural modification induced by thermal poling treatment in surfaces of bulk Herasil silica glass presenting second harmonic generation. Considering model silicon dioxide clusters, calculations based on full multiple scattering approach have been performed in order to explain accurately the differences observed on XANES spectra at different stage of the poling treatment. These structural modifications on extreme surface affect both network and defects by breaking Si-O-Si bridging bonds. Despite of the formation of bridging bond occurring during the thermal depoling -which erases the SHG inside the glass-, the initial structure of the unpoled sample is not reproduced.

Journal Article↗
PubMed2004

Hinfinity fuzzy control design for nonlinear singularly perturbed systems with pole placement constraints: an LMI approach.

This paper considers the problem of designing an H infinity fuzzy controller with pole placement constraints for a class of nonlinear singularly perturbed systems. Based on a linear matrix inequality (LMI) approach, we develop an H infinity fuzzy controller that guarantees 1) the L2-gain of the mapping from the exogenous input noise to the regulated output to be less than some prescribed value, and 2) the closed-loop poles of each local system to be within a pre-specified LMI stability region. In order to alleviate the ill-conditioned LMIs resulting from the interaction of slow and fast dynamic modes, solutions to the problem are given in terms of linear matrix inequalities which are independent of the singular perturbation, epsilon. The proposed approach does not involve the separation of states into slow and fast ones and it can be applied not only to standard, but also to nonstandard singularly perturbed non-linear systems. A numerical example is provided to illustrate the design developed in this paper.

Journal Article↗
PubMed2005

Optimal static output feedback simultaneous regional pole placement.

The problem of optimal simultaneous regional pole placement for a collection of linear time-invariant systems via a single static output feedback controller is considered. The cost function to be minimized is a weighted sum of quadratic performance indices of the systems. The constrained region for each system can be the intersection of several open half-planes and/or open disks. This problem cannot be solved by the linear matrix inequality (LMI) approach since it is a nonconvex optimization problem. Based on the barrier method, we instead solve an auxiliary minimization problem to obtain an approximate solution to the original constrained optimization problem. Moreover, solution algorithms are provided for finding the optimal solution. Furthermore, a necessary and sufficient condition for the existence of admissible solutions to the simultaneous regional pole placement problem is derived. Finally, two examples are given for illustration.

Algorithms↗
PubMed2002

Characterization of all the elastic, dielectric, and piezoelectric constants of uniaxially oriented poled PVDF films.

Polyvinylidene fluoride (PVDF), a piezoelectric material, has many useful applications, for example, as sensors, transducers, and surface acoustic wave (SAW) devices. Models of performance of these devices would be useful engineering tools. However, the benefit of the model is only as accurate as the material properties used in the model. The purpose of this investigation is to measure the elastic, dielectric and piezoelectric properties over a frequency range, including the imaginary part (loss) of these properties. Measurements are difficult because poled material is available as thin films, and not all quantities can be measured in that form. All components of the elastic stiffness, dielectric tensor, and electromechanical coupling tensor are needed in the models. The material studied here is uniaxially oriented poled PVDF that has orthorhombic mm2 symmetry. Presented are the frequency dependence of all nine complex elastic constants, three complex dielectric constants, and five complex piezoelectric constants. The PVDF was produced at Raytheon Research Division, Lexington, MA. Measurements were made on thin films and on stacked, cubical samples. The elastic constants c44D and C55D, the dielectric constants epsilon11T and epsilon22T, as well as the piezoelectric constants g15 and g24 reported here have not been published before. The values were determined by ultrasonic measurements using an impedance analyzer and a least square data-fitting technique.

Journal Article↗
PubMed2005

High-density circumferential pulmonary vein mapping with a 20-pole expandable circular mapping catheter.

The differentiation of pulmonary vein (PV) electrograms from atrial far-field signals during PV isolation (PVI) for atrial fibrillation (AF) may be difficult. In addition, owing to highly variable PV ostial sizes, current fixed-diameter circular PV mapping catheters may not yield optimal electrograms. We evaluated an expandable, circular 15-25 mm diameter, 20-pole mapping catheter for PV mapping during sustained AF in 25 patients. After selective PV angiography to define the ostial position and size, the catheter was introduced into each PV and withdrawn to the most stable proximal position, with optimal wall contact ensured by progressive loop expansion. At each PV ostium, electrograms recorded at high resolution (HR) were compared with those recorded at a resolution similar to that of a standard 10-pole Lasso catheter. After PVI performed during ongoing AF, the presence of residual far-field potentials (FFP) under both set-ups was compared. We mapped 97 PV, including 4 pairs with common ostia. In the HR recordings, the PV potentials had greater amplitude (0.5 +/- 0.1 vs 0.3 +/- 0.1 mV, P = 0.001) and fragmentation, whereas left atrial FFP were minimized. After successful isolation of all PV, FFP were observed in 33% of left superior and 28% of left inferior PV on the HR recordings, compared to 66% and 61%, respectively under normal resolution. Catheter stability and optimal wall contact, in combination with HR electrograms can optimize circumferential PV mapping during AF and improve the discrimination of FFP postablation.

Atrial Fibrillation↗