Bilateral Mixed Laryngoceles: Simultaneous Strobovideolaryngoscopy and External Video Examination

A music medicine practice affords a unique opportunity to diagnose and treat laryngeal music performers. Strobovideolaryngoscopic (SVL) and external video examination of the voice professional or brass instrument player may focus on the vocal folds, yet abnormalities of the supraglottis, neck, and thorax should be appreciated and documented. Laryngoceles are uncommon laryngeal disorders but may occur in up to 5% of benign laryngeal lesions. While many laryngoceles are asymptomatic, they may cause a cough, hoarseness, stridor, sore throat, pain, snoring, or globus sensation. In particular, musicians who play brass instruments are at high risk for laryngocele development. We highlight two patients with symptomatic laryngoceles to present anatomical, historical, classification, epidemiological, diagnostic, and management considerations.     

Role of attention in overshoot: frequency certainty versus uncertainty

Overshoot, the elevation in the threshold for a brief signal that comes on close to masker onset, was measured with signal frequency certain (same frequency on every trial) or uncertain (randomized over trials). In broadband noise, thresholds were higher 2 ms after masker onset than 200 ms later, by 9 dB with frequency certainty, by 6-7 dB with uncertainty. In narrowband noise centered on the signal frequency, thresholds at 2 ms were not elevated with certainty, but were elevated 4-5 dB with uncertainty. Thus, frequency uncertainty leads to less overshoot in broadband noise, to more overshoot in narrowband noise. Reduced overshoot in broadband noise may come about because the masker, given its many frequencies, disrupts focusing at onset as much under certainty as uncertainty. Once the initial disruption dissipates, threshold is lower with certainty so overshoot is greater. In contrast, a narrowband noise with frequencies only near the signal does not disrupt focusing when the signal frequency is known beforehand, so overshoot is absent. When frequency is uncertain, the narrowband noise serves to focus attention on the signal frequency; as this requires time, detection near noise onset is poorer than later on, so overshoot is present.     

Foliation-Preserving Maps Between Solvmanifolds

For i=1,2, let _i be a lattice in a simply connected, solvable Lie group G _i , and let X _i be a connected Lie subgroup of G _i . The double cosets _i g X _i provide a foliation _i of the homogeneous space _i \G _i . Let f be a continuous map from ₁\G ₁ to ₂\G ₂ whose restriction to each leaf of ₁ is a covering map onto a leaf of ₂. If we assume that ₁ has a dense leaf, and make certain technical assumptions on the lattices ₁ and ₂, then we show that f must be a composition of maps of two basic types: a homeomorphism of ₁\G ₁ that takes each leaf of ₁ to itself, and a map that results from twisting an affine map by a homomorphism into a compact group. We also prove a similar result for many cases where G ₁ and G ₂ are neither solvable nor semisimple.     

Chemisorption of nitric oxide by nickel

The adsorption of nitric oxide on clean and pre-oxidized nickel has been investigated by X-ray photoelectron spectroscopy. Three distinct states of chemisorption have been recognised at room temperature; one is dissociative while two involve molecularly adsorbed NO. Pre-exposing the nickel surface to oxygen enabled the activity of the surface to be controlled such that adsorption was confined to only one of the molecular states. The two molecular states are suggested to arise from “bent” and “linear” forms of NO.     

Reasons for and Consequences of the Mysterious Behaviour of Newly Prepared Hemipyridine Solvate of Bis(pyridine)silver(I) Permanganate,Agpy<Subscript>2</Subscript>MnO<Subscript>4</Subscript>*0.5py

Compositions and chemical identities of compounds formed in silver–permanganate–pyridine–water systems, as well as of their recrystallization products obtained from benzene–acetone solutions, have been elucidated. Three compounds: Agpy₂MnO₄ (1), 7Agpy₂MnO₄*Agpy₄MnO₄ (Agpy_2.25MnO₄) (2) and Agpy₂MnO₄ * 0.5py (Agpy_2.5MnO₄) (3) were isolated. The compositions of the products obtained by a method described previously [1] for the preparation of ‘Agpy₂MnO₄’ (1*) and ‘Agpy_2.5MnO₄’ (2*) were determined and the constituent compounds identified. It has been established that the instability of compound (3) is due to the presence of the benzene, substituting for pyridine at the solvate sites. The benzene, however, is released at room temperature, disrupting the crystal lattice of (3), and the whole process leads to the loss of the solvate pyridine and to the formation of (1).     

The effect of reduction and temperature on the electronic core levels of tungsten and molybdenum in WO3 and WxMo1−xO3—A photoelectron spectroscopic study

X-Ray photoelectron spectroscopy (XPS) has been applied to electrochromic, reduced WO₃ and W_xMo_1?xO₃ crystals. In metal-reduced phases containing crystallographic shear planes the formation of Mo⁵⁺ (preferentially) and W⁵⁺ is observed in addition to that of the six-valent states. W⁵⁺ and W⁶⁺ are also dominant in H⁺-bombarded WO₃ indicating the formation of bronzes H_xWO₃. Significant differences are observed between single-crystal and “amorphous” oxides. The five-valent state is interpreted as being due to electron trapping and polaron formation. Under Ar⁺ bombardment the crystallinity of the surface is destroyed and a continuous distribution of W⁰, W⁴⁺, W⁵⁺, and W⁶⁺ is found similar to that observed for amorphous thin films. At low temperatures the (?-δ) metal-insulator (M-I) transformation of H⁺:WO₃ is accompanied by a spontaneous change in the linewidth of W⁵⁺ core levels but not of W⁶⁺ states. This is in accordance with recent theoretical approaches to M-I transformations.     

Some applications of computer enhanced Raman spectroscopy

Intensity and wavenumber signals were transferred from a Cary 82 laser-Raman spectrometer to a Nicolet 1180 computer, enabling Raman spectra to be acquired in digital form. This has made it possible to store and process Raman spectra by means of computer. The paper discusses the hardware and software aspects of data collection, and briefly mentions some applications.     

An age-structured model for the spread of epidemic cholera: Analysis and simulation

Occasional outbreaks of cholera epidemics across the world demonstrate that the disease continues to pose a public health threat. Traditional models for the spread of infectious diseases are based on systems of ordinary differential equations. Since disease dynamics such as vaccine efficacy and the risk for contracting cholera depend on the age of the humans, an age-structured model offers additional insights and the possibility of studying the effects of treatment options. The model investigated is given as a system of hyperbolic (first-order) partial differential equations in combination with ordinary differential equations. First, using a representation from the method of characteristics and a fixed point argument, we prove the existence and uniqueness of a solution to our nonlinear system. Then we present a finite difference approximation to the model and study the effect of high and low rates of shedding of cholera vibrios on the dynamics of the spread of the disease. The simulations demonstrate the explosive nature of cholera outbreaks that is observed in reality. The contrast of results for high and low rates of shedding of vibrios suggest a possible underlying cause for this effect.     

A Network Analysis Model for Disambiguation of Names in Lists

In research and application, social networks are increasingly extracted from relationships inferred by name collocations in text-based documents. Despite the fact that names represent real entities, names are not unique identifiers and it is often unclear when two name observations correspond to the same underlying entity. One confounder stems from ambiguity, in which the same name correctly references multiple entities. Prior name disambiguation methods measured similarity between two names as a function of their respective documents. In this paper, we propose an alternative similarity metric based on the probability of walking from one ambiguous name to another in a random walk of the social network constructed from all documents. We experimentally validate our model on actor-actor relationships derived from the Internet Movie Database. Using a global similarity threshold, we demonstrate random walks achieve a significant increase in disambiguation capability in comparison to prior models. Bradley A. Malin is a Ph.D. candidate in the School of Computer Science at Carnegie Mellon University. He is an NSF IGERT fellow in the Center for Computational Analysis of Social and Organizational Systems (CASOS) and a researcher at the Laboratory for International Data Privacy. His research is interdisciplinary and combines aspects of bioinformatics, data forensics, data privacy and security, entity resolution, and public policy. He has developed learning algorithms for surveillance in distributed systems and designed formal models for the evaluation and the improvement of privacy enhancing technologies in real world environments, including healthcare and the Internet. His research on privacy in genomic databases has received several awards from the American Medical Informatics Association and has been cited in congressional briefings on health data privacy. He currently serves as managing editor of the Journal of Privacy Technology. Edoardo M. Airoldi is a Ph.D. student in the School of Computer Science at Carnegie Mellon University. Currently, he is a researcher in the CASOS group and at the Center for Automated Learning and Discovery. His methodology is based on probability theory, approximation theorems, discrete mathematics and their geometries. His research interests include data mining and machine learning techniques for temporal and relational data, data linkage and data privacy, with important applications to dynamic networks, biological sequences and large collections of texts. His research on dynamic network tomography is the state-of-the-art for recovering information about who is communicating to whom in a network, and was awarded honors from the ACM SIG-KDD community. Several companies focusing on information extraction have adopted his methodology for text analysis. He is currently investigating practical and theoretical aspects of hierarchical mixture models for temporal and relational data, and an abstract theory of data linkage. Kathleen M. Carley is a Professor of Computer Science in ISRI, School of Computer Science at Carnegie Mellon University. She received her Ph.D. from Harvard in Sociology. Her research combines cognitive science, social and dynamic networks, and computer science (particularly artificial intelligence and machine learning techniques) to address complex social and organizational problems. Her specific research areas are computational social and organization science, social adaptation and evolution, social and dynamic network analysis, and computational text analysis. Her models meld multi-agent technology with network dynamics and empirical data. Three of the large-scale tools she and the CASOS group have developed are: BioWar a city, scale model of weaponized biological attacks and response; Construct a models of the co-evolution of social and knowledge networks; and ORA a statistical toolkit for dynamic social Network data.     

Uniaxial extensional flow for a viscoelastic model that displays thixotropic yield stress behavior

Homogeneous uniaxial extensional flow of a viscoelastic fluid, namely, the partially extending strand convection model combined with a Newtonian solvent, is investigated for large relaxation time. Initial value problems are addressed, for prescribed constant tensile stress. The limit of large relaxation time introduces a slow time scale of evolution, in addition to a fast time scale for flow. Numerical solutions of the original equations show distinct stages of evolution, which are mathematically analyzed with asymptotic analyses for multiple time scales. We discuss the stages of evolution from equilibrium, as well as unloading the applied stress from a yielded solution. The overall picture which emerges captures a number of features which are usually associated with thixotropic yield stress fluids, such as delayed yielding, and hysteresis for up and down stress ramping. Even at large applied tensile stress, there is persistence of an interval of parameters where the deformation rate increases quickly, only after a delayed response.