Spatiotemporal optical dark X solitary waves.

We introduce spatiotemporal optical dark X solitary waves of the (2+1)D hyperbolic nonlinear Schrödinger equation (NLSE), which rules wave propagation in a self-focusing and normally dispersive medium. These analytical solutions are derived by exploiting the connection between the NLSE and a well-known equation of hydrodynamics, namely the type II Kadomtsev-Petviashvili (KP-II) equation. As a result, families of shallow water X soliton solutions of the KP-II equation are mapped into optical dark X solitary wave solutions of the NLSE. Numerical simulations show that optical dark X solitary waves may propagate for long distances (tens of nonlinear lengths) before they eventually break up, owing to the modulation instability of the continuous wave background. This finding opens a novel path for the excitation and control of X solitary waves in nonlinear optics.

Optical Kerr Spatiotemporal Dark-Lump Dynamics of Hydrodynamic Origin.

There is considerable fundamental and applicative interest in obtaining nondiffractive and nondispersive spatiotemporal localized wave packets propagating in optical cubic nonlinear or Kerr media. Here, we analytically predict the existence of a novel family of spatiotemporal dark lump solitary wave solutions of the (2+1)D nonlinear Schrödinger equation. Dark lumps represent multidimensional holes of light on a continuous wave background. We analytically derive the dark lumps from the hydrodynamic exact soliton solutions of the (2+1)D shallow water Kadomtsev-Petviashvili model, inheriting their complex interaction properties. This finding opens a novel path for the excitation and control of optical spatiotemporal waveforms of hydrodynamic footprint and multidimensional optical extreme wave phenomena.

Cerebral and spinal cord tanycytic ependymomas in a young adult with a mutation in the NF2 gene.

We studied one frontal lobe tumor and multiple spinal cord tumors (one in an extramedullary location) that had been resected from a 24-year-old man. The frontal lobe tumor was well demarcated and non-infiltrating, and consisted of eosinophilic, elongated fibrillary cells arranged in a fascicular pattern. A similar histology was reproduced in the spinal cord tumors, with additional areas showing standard features of ependymoma. Immunohistochemical and ultrastructural observations revealed that all the tumors were ependymal in nature with positivity for GFAP and epithelial membrane antigen and negativity for oligodendrocyte transcription factor 2, showing intra- and intercellular microrosettes, leading us to a diagnosis of tanycytic ependymoma for the frontal lobe tumor and tanycytic ependymoma with ordinary ependymomatous component for the spinal cord tumors. The spinal extramedullary tumor was a schwannoma. Importantly, a heterozygous truncating mutation in the NF2 gene was identified in the blood lymphocytes from the patient. It is known that multiple nervous system tumors can occur in neurofibromatosis type 2 (NF2), which is caused by mutation in the NF2 gene, and that occurrence of ependymoma, including the tanycytic variant, can be associated with this genetic condition. The present case provides further information about the clinicopathology of tanycytic ependymoma with details of the immunohistochemical, ultrastructural and genetic features.

KP solitons, total positivity, and cluster algebras.

Soliton solutions of the KP equation have been studied since 1970, when Kadomtsev and Petviashvili [Kadomtsev BB, Petviashvili VI (1970) Sov Phys Dokl 15:539-541] proposed a two-dimensional nonlinear dispersive wave equation now known as the KP equation. It is well-known that the Wronskian approach to the KP equation provides a method to construct soliton solutions. The regular soliton solutions that one obtains in this way come from points of the totally nonnegative part of the Grassmannian. In this paper we explain how the theory of total positivity and cluster algebras provides a framework for understanding these soliton solutions to the KP equation. We then use this framework to give an explicit construction of certain soliton contour graphs and solve the inverse problem for soliton solutions coming from the totally positive part of the Grassmannian.

Relationship between Perceived Leg Length Discrepancy at One Month and Preoperative Hip Abductor Muscle Elasticity in Patients after Total Hip Arthroplasty.

OBJECTIVE: Preoperative factors related to perceived leg length discrepancy (PLLD) after total hip arthroplasty (THA) are not well studied. This study aimed to examine the preoperative factors, including hip abductor modulus, related to PLLD one month after THA. METHODS: The study included 73 patients diagnosed with osteoarthritis secondary to developmental dysplasia of the hip and a posterior approach to surgery. Multiple logistic regression analysis was performed using the presence or absence of PLLD as the dependent variable and preoperative hip abductor's modulus of elasticity, pain, hip abduction range of motion, hip abductor muscle strength and pelvic obliquity as the independent variable. Additionally, receiver operating characteristic curves were used for the extracted variables for calculating the cutoffs, sensitivity, specificity and area under the curve (AUC) to determine the presence or absence of PLLD. The significance level was set at p<0.05. RESULTS: The hip abductor modulus (odds ratio=1.13; 95% confidence interval=1.06-1.21; p<0.001) was selected as a preoperative factor. The cutoff value to determine the presence or absence of a PLLD was 16.32 kPa. The sensitivity and specificity were 81.8% and 72.5%, respectively, and the AUC was 0.8137. CONCLUSION: The hip abductor muscle elastic modulus affected PLLD one month after THA. If the preoperative hip abductor elastic modulus is higher than the cutoff value, it may affect the appearance of PLLD at one month postoperatively.

Retrieval of snow physical parameters using a ground-based spectral radiometer.

A ground-based spectral radiometer system for albedo and flux (GSAF) was developed to retrieve a mass concentration of snow impurities and effective snow grain size automatically. The GSAF measures spectral albedo and diffuse fraction with a single sensor to omit a radiometric calibration. The deviation from an ideal cosine response of the sensor to insolation is precisely corrected. The snow physical parameters can be retrieved with the GSAF even under cloudy conditions, because the effect of illumination conditions on albedo is considered in a retrieval algorithm. Continuous measurements with the GSAF at two snowfields in Hokkaido, Japan, showed the correlations between the retrieved parameters and in situ measurements (R=0.595 to 0.940).

Diagnosing intra-cranial and cervical artery dissection using MRI as the initial modality.

Dissection of cranial and cervical arteries is a relatively frequent clinical condition. However, it is difficult to diagnose a dissection when patients present with relatively mild symptoms. Various radiological techniques are used as diagnostic tools. This study analyzed retrospectively the characteristics of cranial and cervical artery dissections using "MR first concept", with MRI as the first-choice diagnostic modality for all new patients with neurological symptoms. The patients who were admitted in Ohnishi neurological center between January 2001 and December 2014 were included. MRI was used as the initial investigation for all new patients, including those with mild symptoms such as headache or vertigo only. The patients were divided into carotid group and vertebral group. The statistical comparison was performed between these two groups. A total of 164 patient cases were analyzed. In 44 (26.8%) and 120 (73.2%) patients, dissection occurred in the carotid group and vertebral group, respectively. Concerning the type of onset, 52 patients presented with only subjective symptoms accompanied with ischemic or hemorrhagic lesions, 97 patients with ischemic symptoms and 15 patients with subarachnoid hemorrhage. There were statistically significant differences between the carotid and vertebral groups in terms of hemiparesis, aphasia, history of trauma, headache and vertigo. Patients with only a headache and those with no ischemic features had no worsening symptoms. The symptom of headache or neck pain only is more frequent than previously reported. The "MR first concept" would prove useful for early diagnosis of dissections and early treatment.

Estrogen blocks 3-nitropropionic acid-induced Ca2+i increase and cell damage in cultured rat cerebral endothelial cells.

Systemic administration of 3-nitropropionic acid (3-NPA, a mycotoxin) induces brain damage accompanied by disturbance in the blood-brain barrier (BBB). Since the endothelial cells are important components of the BBB and the first target of a systemic intoxication, in the present study, the effect of 3-NPA on primary cultured rat brain endothelial cells (rBECs) was examined by studying intracellular Ca(2+) ([Ca(2+)](i)) response using imaging techniques with fura-2. rBECs were prepared using a method of Kis et al. [Eur. J. Pharmacol. 368 (1999) 35-42] and Szabo et al. [Neurobiology 5 (1997) 1-16]. Almost all cells were immunoreactive to antibody against the factor VIII-related antigen (von-Willebrand factor). They showed a typical dose-dependent increase of [Ca(2+)](i) in response to ATP or bradykinin. Low concentrations of 3-NPA (1.7 mM, 3.4 mM) caused no changes, and a medium concentration (6.8 mM) increased the [Ca(2+)](i) gradually and progressively, and the increase was reversed incompletely back to the resting level after washing. A high concentration (13.6 mM) increased the [Ca(2+)](i) irreversibly. These elevations of [Ca(2+)](i) were absent in a Ca(2+)-free medium. In endothelial cells treated with 17beta-estradiol (above 10(-5) M) or with a selective estrogen receptor modulator, tamoxifen (5 x 10(-7) M), no elevation of [Ca(2+)](i) was observed with 3-NPA treatment. The response to ATP was impaired after application of 3-NPA, but it was preserved by cotreatment with 17beta-estradiol or tamoxifen. An estrogen receptor antagonist ICI 182,780 inhibited these effects by 17beta-estradiol or tamoxifen. Lysosomal neutral red uptake and TUNEL experiments revealed the necrotic but not apoptotic cell death at least in this acute stage. Data indicate that a medium to high concentration of 3-NPA induces damage on rBECs as revealed by an accumulation of [Ca(2+)](i), but the damage was protected by cotreatment with 17beta-estradiol or tamoxifen, suggesting that estrogen may be protective for the brain vascular damage via estrogen receptor.

On the dispersion managed soliton.

We review various methods used to study the dispersion managed soliton for nonlinear return-to-zero pulse propagation in optical fibers. A numerical averaging method, the guiding center soliton, the variational method both with a simple and with an extended ansatz, as well as the multiscale theory are discussed and numerically compared, allowing us to show their domains of applicability. Their relative merits and demerits are then exposed. (c) 2000 American Institute of Physics.

High titer retroviral gene transduction to neural progenitor cells for establishment of donor cells for neural transplantation to parkinsonian model rats.

Neural progenitor cells (NPCs) are expected to be useful donor sources for cell transplantation therapy in Parkinson's disease. However, control of the differentiational lineage, especially into dopaminergic neurons, is still difficult. Thus, genetic modification of NPCs to produce l-dopa is potentially useful. The present study prepared high titer retrovirus carrying human tyrosine hydroxylase-1 (HTH-1) gene. HTH-1 gene could be efficiently transduced into NPCs obtained from the E12.5 rat mesencephalon. This retroviral gene transduction caused no apparent changes in survival, proliferation, or differentiation. In vitro, HTH-1 gene-transduced NPCs released little l-dopa and addition of tetrahydrobiopterin, the cofactor of tyrosine hydroxylase, was required for production of l-dopa. In vivo, three of seven hemi-parkinsonian model rats that received HTH-1 gene-transduced donor NPCs achieved functional recovery. High titer retroviral vector for gene transduction could be used to prepare NPCs for transplantation to hemi-parkinsonian model rats. However, functional recovery after transplantation of HTH-1 gene-transduced NPCs was incomplete.

Classification of the superior petrosal veins and sinus based on drainage pattern.

BACKGROUND: The increasing number of reports of complications after sacrificing the superior petrosal veins, the largest veins in the posterior fossa, has led to a need for an increased understanding of the anatomy of these veins and the superior petrosal sinus into which they empty. OBJECTIVE: To examine the anatomy of the superior petrosal veins and their size, draining area, and tributaries, as well as the anatomic variations of the superior petrosal sinus. METHOD: Injected cadaveric cerebellopontine angles and 3-dimensional multifusion angiography images were examined. RESULTS: The 4 groups of the superior petrosal veins based on their tributaries, course, and draining areas are the petrosal, posterior mesencephalic, anterior pontomesencephalic, and tentorial groups. The largest group was the petrosal group. Its largest tributary, the vein of the cerebellopontine fissure, was usually identifiable in the suprafloccular cistern located above the flocculus on the lateral surface of the middle cerebellar peduncle. The medial or lateral segment of the superior petrosal sinus was absent in 40% of cerebellopontine angles studied with venography. CONCLUSION: The superior petrosal veins and their largest tributaries, especially the vein of the cerebellopontine fissure, should be preserved if possible. Obliteration of superior petrosal sinuses in which either the lateral or medial portion is absent may result in loss of the drainage pathway of the superior petrosal veins. Preoperative assessment of the superior petrosal sinus should be considered before transpetrosal surgery in which the superior petrosal sinus may be obliterated.

Pleiotrophin exhibits a trophic effect on survival of dopaminergic neurons in vitro.

To understand what kind of trophic factors are up-regulated in dopamine (DA)-depleted striatum, we first analysed the up-regulation of mRNAs using a DNA microarray in DA-depleted striatum where DAergic inputs were denervated by 6-OHDA. We then investigated whether or not such trophic factors had an effect on cultured dopaminergic neurons. The microarray analysis revealed that pleiotrophin (PTN), glial-derived neurotopic factor (GDNF) and others were up-regulated in DA-depleted striatum. As PTN has been reported to have a wide range of trophic effects on neurons, we focused on the functional role of PTN in the present study. The increase in PTN mRNA was confirmed by Northern blotting at 1-3 weeks after the lesion, reaching a peak at 1 week. In embryonic day 15 mesencephalic neuron culture, PTN increased the number of tyrosine hydroxylase (TH) -positive neurons in a dose-dependent manner (125.2 +/- 2.0% of the control at 50 ng/mL), while a family protein, midkine (10 ng/mL) did not show any trophic effect (99.3 +/- 0.7%). In addition, the PTN effect on DAergic neurons was additive to the GDNF effect. As PTN did not increase the number of microtubule-associated protein-2 (MAP 2)-positive neurons or promote the proliferation of dopaminergic progenitors in a bromodeoxyuridine (BrdU) labelling study, the effect appeared to enhance the specific survival of dopaminergic neurons. Expression of PTN receptors (syndecan-3, PTP-zeta) was detected on the cultured mesencephalic neurons, and also up-regulated in DA-depleted striatum. The data indicate that PTN is up-regulated in DA-depleted striatum and exhibits a trophic effect specifically on the survival of cultured dopaminergic neurons.