bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes of 122 diverse adult and pediatric cord blood transplant recipients from a large cord blood bank
Authors: Ballen Karen K. , Haley N. Rebecca , Kurtzberg Joanne , Lane Thomas A. , Lindgren Bruce R. , Miller John P. , Newman Bruce , McCullough Jeff
Published: October 2006

BACKGROUND: Umbilical cord blood is a useful stem cell source for some patients. The American Red Cross Cord Blood Program was established as a national network of cord blood banks. Nine thousand cord blood units were cryopreserved for transplant use.

STUDY DESIGN AND METHODS: This report summarizes the experience with the first 125 cord blood units that have been distributed for transplant for 122 patients at 36 different transplant centers worldwide. Patients were treated with a variety of conditioning regimens.

RESULTS: Most patients had acute myelogeneous leukemia (21%), genetic disorders (22%), or acute lymphoblastic leukemia (18%). The median age of the patients was 11 years with a range of 2 months to 63 years. The patients ranged in size from 3 to 120 kg (median, 39 kg). The median number of days to neutrophil engraftment was 22, and the median number of days to platelet engraftment was 63. Thirty percent of patients experienced Grades III to IV acute graft‐versus‐host disease (GVHD). Survival at 1 year after transplant was 35 percent, with recurrent disease the major cause of death. In multivariate analysis, only age less than 18 years was a significant predictor for improved survival. Forty‐two percent of patients were non‐Caucasian. Engraftment, GVHD, survival, and disease‐free survival were similar among Caucasian and non‐Caucasian patients.

CONCLUSION: Umbilical cord blood serves as a satisfactory stem cell source for a diverse group of pediatric and adult patients.
A New Perspective on Ownership Identities in China's Listed Companies
Authors: Delios Andrew , Wu Zhi Jian , Zhou Nan
Published: October 2006

We introduce a new perspective on the conceptualization and measurement of ownership identities of China's listed companies. Previous work analyzing the strategy and performance implications of the ownership structure in Chinese firms has used the official categorization provided by state bodies in China. In this categorization, state shareholding, legal person shareholding and A-shares dominate. This official categorization, however, obscures the ultimate identity of a shareholder; this can confound conceptual and empirical work on die strategy and performance implications of ownership identity. We refine the existing classification by recategorizing shareholders into 16 types, which can then be regrouped into relevant categories of shareholders, such as government or private, to enable analysis of ownership identity and ownership concentration issues in China's listed companies. Our new classification can help provide consistency in the burgeoning research on the strategy and performance implications of the concentration and identity aspects of ownership structure in China's listed companies.
Organizational Culture in China: An Analysis of Culture Dimensions and Culture Types
Authors: Tsui Anne S. , Wang Hui , Xin Katherine R.
Published: October 2006

Abstradct

The economic and market reforms in China have given rise to firms with three distinct types of ownership: state-owned enterprises, private domestic enterprises, and foreign-invested firms. The three studies reported in this paper addressed the questions of whether organizational culture varies among firms with different ownership structures and whether it relates to firm performance or employee attitudes as it has been observed in US firms. The first study employed an inductive approach to identify culture dimensions and found five common dimensions across these different types of firms. In the second study, we derived an empirical taxonomy of four organizational culture types involving different configurations of the five organizational culture dimensions, and found a systematic relationship between these culture types and a measure of perceived firm performance. The third study confirmed the relationship between organizational culture types and middle manager attitudes. Suggestions are offered for future research building on the organizational culture dimensions and culture types introduced in these studies.
Approaches to Scale Development in Chinese Management Research
Authors: Farh Jiing-Lih , Cannella Albert A. , Lee Cynthia
Published: October 2006

We classify survey scales or measures currently used in Chinese management research along two dimensions - the source of the scale and expectations about its cultural specificity. Based on these two dimensions, we differentiate four approaches to scale development: translation, adaptation, de-contextualization, and contextualization. We describe the key assumptions, strengths and limitations of each approach and their roles in Chinese management research. We illustrate the four approaches by commenting on the five articles in this special issue.
A Conceptual Framework for a Psychometric Theory for Standard Setting with Examples of Its Use for Evaluating the Functioning of Two Standard Setting Methods
Authors: Reckase Mark D.
Published: October 2006

A conceptual framework is proposed for a psychometric theory of standard setting. The framework suggests that participants in a standard setting process (panelists) develop an internal, intended standard as a result of training and the participant's background. The goal of a standard setting process is to convert panelists' intended standards to points on a test's score scale. Psychometrics is involved in this process because the points on the score scale are estimated from ratings provided by participants. The conceptual framework is used to derive three criteria for evaluating standard setting processes. The use of these criteria is demonstrated by applying them to variations of bookmark and modified Angoff standard setting methods.
Rejoinder: A Further Discussion of Job Analysis and Use of KSAs in Developing Licensure and Certification Examinations: A Response to LaDuca
Authors: Wang Ning , Witt Elizabeth A. , Schnipke Deborah
Published: October 2006

In his commentary to our paper on the use of knowledge, skill, and ability statements in developing credentialing examinations (

Wang, Schnipke, & Witt, 2005
), Dr. LaDuca set forth his concerns while commending our paper for providing helpful insights into the importance of careful delineation of KSAs. We believe that there is little substantive disagreement between our position and Dr. LaDuca's. Based on the counterarguments offered in his commentary, we believe that some misunderstanding occurred regarding our main point. Our response here further clarifies our main point to address Dr. LaDuca's criticisms. Additional explanations are provided to indicate that our paper is intended to address job analysis issues over a broader and diverse array of professions/occupations/fields, and our perspective is not limited to the context of credentialing physicians. We recommend that, for such professions/occupations/fields for which task inventory constitutes an appropriate approach to job analysis, the use of KSAs should be considered to establish a linkage between the credentialing examination and the job tasks.
Nonlinear Modeling of Mechanical Gas Face Seal Systems Using Proper Orthogonal Decomposition
Authors: Zhang Haojiong , Miller Brad A. , Landers Robert G.
Published: October 2006

An approach based on proper orthogonal decomposition and Galerkin projection is presented for developing low-order nonlinear models of the gas film pressure within mechanical gas face seals. A technique is developed for determining an optimal set of global basis functions for the pressure field using data measured experimentally or obtained numerically from simulations of the seal motion. The reduced-order gas film models are shown to be computationally efficient compared to full-order models developed using the conventional semidiscretization methods. An example of a coned mechanical gas face seal in a flexibly mounted stator configuration is presented. Axial and tilt modes of stator motion are modeled, and simulation studies are conducted using different initial conditions and force inputs. The reduced-order models are shown to be applicable to seals operating within a wide range of compressibility numbers, and results are provided that demonstrate the global reduced-order model is capable of predicting the nonlinear gas film forces even with large deviations from the equilibrium clearance.
Generation of Composite Surfaces With Bimodal Distribution and Contact Analysis for Optimum Tribological Performance
Authors: Wan Kim Tae , Bhushan Bharat
Published: October 2006

Most contact analyses assume that the surface height distributions follow a single modal distribution. However, there are many surfaces with multi-modal roughness distributions, e.g., magnetic particulate tape, super alloys with precipitates, and hydrophobic leaves. In this study, an algorithm is developed to generate bimodal surfaces by superimposing particles with radii following a Gaussian distribution on a Gaussian rough surface. Two different cases are presented to produce composite surfaces with particles; the first case is particles sitting on a surface and the other case is particles sitting on the mean plane of a surface. Statistical analysis is carried out for the generated bimodal surfaces to study the effect of the bimodal roughness distributions on the surface’s probability density function shapes. Contact analysis is also conducted to identify optimum bimodal roughness distributions for low friction, stiction, and wear. It is assumed that particles and matrix have uniform elastic properties as it is a reasonable assumption in some applications such as magnetic tapes. Variation of fractional contact area, maximum contact pressure, and relative meniscus force as functions of relative mean radius and relative standard deviation of particles are studied for different values of particle densities. It is found that bimodal surfaces with lower particle density are beneficial to low friction and stiction, whereas those with higher particle density are beneficial to low wear. Relative mean radii of particles of 2–3 in bimodal surfaces with particles sitting on surface and 3–5 in bimodal surfaces with particles sitting on the mean plane of surface are desirable for low friction, stiction, and wear.
Influence of Microstructure in Partial-Slip Fretting Contacts Based Upon Two-Dimensional Crystal Plasticity Simulations
Authors: Goh C.-H. , McDowell D. L. , Neu R. W.
Published: October 2006

The role of microstructure is quite significant in fretting because the scale of plastic strain localization near the surface is on the order of key microstructure features. A dual-phase Ti-6Al-4V alloy that tends to be susceptible to fretting is considered as a model material. Fretting is simulated using a two-dimensional finite element analysis. A crystal plasticity theory with a two-dimensional planar triple slip idealization is employed to represent the hexagonal close packed structure of the α phase of Ti. Modifications of the slip system strengths enable multiple phases to be considered. In this study, the effects of grain orientation distribution, grain size and geometry, as well as the phase distribution and their arrangement, are considered in simulations. Implications of the results are discussed.
A Tribological Comparison of Pure and Boronized Chromium
Authors: Ribeiro R. , Ingole S. , Usta M. , Bindal C. , Ucisik A. H. , Liang H.
Published: October 2006

Boronized metals are potential candidate materials for various industrial applications as well as for joint arthroplasty. This is due to their high hardness and corrosion resistance. In the present research, we investigated the tribological performance of boronized chromium when worn against bearing steel E52100. Pure chromium was used as a control material and tested under similar conditions. Three test conditions were used—dry sliding, with water, and with simulated body fluid (SBF). The highest coefficient of friction obtained was for chromium boride under dry sliding conditions. Water and SBF acted as lubricants and lowered the coefficient of friction. The friction coefficient for Cr and chromium boride was lowest under SBF conditions. SEM analysis showed that the wear modes were different under different test conditions. TEM analysis showed a layered-like structure of debris that could have acted as a lubricant and caused a very low friction coefficient as the tests progressed.
Effect of Surface Radiation on Multiple Natural Convection Solutions in a Square Cavity Partially Heated from Below
Authors: Ridouane El Hassan , Hasnaoui Mohammed
Published: October 2006

A numerical study of natural convection with surface radiation in an air filled square enclosure with a centrally heated bottom wall and cooled upper wall is presented. The vertical walls and the rest of the bottom wall are assumed to be insulated. The problem is studied for Rayleigh numbers Ra, ranging from 103 to 4×106 and surfaces emissivity ε, varying from 0 to 1. The governing equations, written in terms of stream function-vorticity formulation, are solved using a finite difference approach. It is found that, under these heating/cooling conditions, three different steady-state solutions are possible in the ranges of the parameters considered. Results are presented detailing the occurrence of each steady-state solution and the effect of Ra and ε on its range of existence. It is found that the surface radiation alters significantly the existence ranges of the solutions. For each solution, convective and radiative contributions to the global heat transfer are also quantified for various Ra and ε. The influence of the heated surface dimension on the fluid flow and thermal patterns is also presented by comparing the present results against those obtained by the authors in an earlier study within a square cavity totally heated from below.
Metaheuristic Optimization of a Discrete Array of Radiant Heaters
Authors: Porter Jason M. , Larsen Marvin E. , Barnes J. Wesley , Howell John R.
Published: October 2006

The design of radiant enclosures is an active area of research in radiation heat transfer. When design variables are discrete such as for radiant heater arrays with on-off control of individual heaters, current methods of design optimization fail. This paper reports the development of a metaheuristic thermal radiation optimization approach. Two metaheuristic optimization methods are explored: simulated annealing and tabu search. Both approaches are applied to a combinatorial radiant enclosure design problem. Configuration factors are used to develop a dynamic neighborhood for the tabu search algorithm. Results are presented from the combinatorial optimization problem. Tabu search with a problem specific dynamic neighborhood definition is shown to find better solutions than the benchmark simulated annealing approach in less computation time.
Design Optimization of Size and Geometry of Vortex Promoter in a Two-Dimensional Channel
Authors: Icoz Tunc , Jaluria Yogesh
Published: October 2006

Thermal management of electronic equipment is one of the major technical problems in the development of electronic systems that would meet increasing future demands for speed and reliability. It is necessary to design cooling systems for removing the heat dissipated by the electronic components efficiently and with minimal cost. Vortex promoters have important implications in cooling systems for electronic devices, since these are used to enhance heat transfer from the heating elements. In this paper, an application of dynamic data driven optimization methodology, which employs concurrent use of simulation and experiment, is presented for the design of the vortex promoter to maximize the heat removal rate from multiple protruding heat sources located in a channel, while keeping the pressure drop within reasonable limits. Concurrent use of computer simulation and experiment in real time is shown to be an effective tool for efficient engineering design and optimization. Numerical simulation can effectively be used for low flow rates and low heat inputs. However, with transition to oscillatory and turbulent flows at large values of these quantities, the problem becomes more involved and computational cost increases dramatically. Under these circumstances, experimental systems are used to determine the component temperatures for varying heat input and flow conditions. The design variables are taken as the Reynolds number and the shape and size of the vortex promoter. The problem is a multiobjective design optimization problem, where the objectives are maximizing the total heat transfer rate Q and minimizing the pressure drop ΔP. This multiobjective problem is converted to a single-objective problem by combining the two objective functions in the form of weighted sums.
Characterization of Multiaxial Constitutive Properties of Rubbery Polymers
Authors: Chakkarapani V. , Ravi-Chandar K. , Liechti K. M.
Published: October 2006

Rubbery response of polyurea is examined under monotonic loading in the confined compression, composite compression, and Arcan shear configurations. For polyurea prepared by a casting process, it is shown that while the bulk response is significantly nonlinear, and well fitted by the Tait equation, the shear resistance is extremely small. In contrast, polyurea formed by a spray process shows significant compressibility, inelastic volumetric deformation, and significantly enhanced shear resistance.
Loading History Effects on the Creep and Relaxation Behavior of Thermoplastics
Authors: Khan Fazeel
Published: October 2006

Experimental investigations have been performed to understand the effects of prior loading on the creep and stress relaxation behavior of an amorphous polymer (polyphenylene oxide) and a semi-crystalline polymer (high density polyethylene) at room temperature. Of particular interest was the positioning of creep and relaxation tests on the unloading segment of stress-strain curves for tensile and compressive loading. The data was found to be quite unlike that obtained in typical tests performed on the loading segment; i.e., with no unloading history. Specifically, in relaxation tests, rather than registering a monotonic drop, the stress first increases then decreases. The rate of change of stress, therefore, is initially positive and then becomes negative. Similarly, in creep tests, the strain was found to decrease at first, and then began to increase. This has been labeled as rate-reversal in the context of relaxation and creep test data, and, furthermore, the test point has been found to influence the stress-time and strain-time data, respectively. In relaxation, for instance, at large strain values, the initial increase in stress is considerably smaller than the subsequent drop and the rate reversal occurs very rapidly. Conversely, at smaller strain values, the initial increase in stress dominates and the rate reversal may occur only after several hours. Analogous changes are observed during creep as tests are performed at lower stress values. Preliminary attempts at modeling the aforementioned creep and relaxation behavior have been made by modifying the existing formulation of the viscoplasticity theory based on overstress, which is a constitutive state-variable based model. A modified, single-element standard linear solid serves as a suitable descriptor of the model. Linking of two elements in series has shown some promise towards the modeling of the rate-reversal behavior. Experimental data and results of preliminary simulations are presented in this study.
A Battery-Powered Car Run Down
Authors: Kirsch David A.
Published: October 2006

Who Killed the Electric Car?
.
By Chris Paine
. Sony Pictures Classics, New York, 2006. 92 minutes.
www.sonyclassics.com/whokilledtheelectriccar/

The film chronicles the history of the General Motors EV1, exploring cultural, economic, business, and political aspects of its fate.
Dynamic Nuclear Actin Assembly by Arp2/3 Complex and a Baculovirus WASP-Like Protein
Authors: Goley Erin D. , Ohkawa Taro , Mancuso Joel , Woodruff Jeffrey B. , D'Alessio Joseph A. , Cande W. Zacheus , Volkman Loy E. , Welch Matthew D.
Published: October 2006

Diverse bacterial and viral pathogens induce actin polymerization in the cytoplasm of host cells to facilitate infection. Here, we describe a pathogenic mechanism for promoting dynamic actin assembly in the nucleus to enable viral replication. The baculovirus
Autographa californica
multiple nucleopolyhedrovirus induced nuclear actin polymerization by translocating the host actin-nucleating Arp2/3 complex into the nucleus, where it was activated by p78/83, a viral Wiskott-Aldrich syndrome protein (WASP)–like protein. Nuclear actin assembly by p78/83 and Arp2/3 complex was essential for viral progeny production. Recompartmentalizing dynamic host actin may represent a conserved mode of pathogenesis and reflect viral manipulation of normal functions of nuclear actin.
FLAT PASS-BANDS OF ONE-DIMENSIONAL PHOTONIC CRYSTALS COMPOSED OF MULTIPLE QUANTUM WELLS WITH GAUSSIAN-DISTRIBUTED REFRACTIVE INDICES
Authors: LIU CHUNG PING , WU CHIH JUNG , LIU KANG HUAI , HUANG GUO JANG , GU BEN YUAN
Published: October 2006

Transmissions of one-dimensional (1D) photonic crystals (PCs) containing multiple quantum wells with Gaussian-distributed refractive indices are calculated with the use of the transfer-matrix method. The transmission spectrum of this kind of structures exhibits flatted pass-bands. The resonant peaks in the transmission spectrum of the conventional 1D PCs have been significantly suppressed. It is expected that this kind of structures may favor the fabrication of optical filters in applications to micro-optical devices.
ATTACHMENT BONDS FOR HUMAN-LIKE ROBOTS
Authors: CAÑAMERO LOLA , BLANCHARD ARNAUD J. , NADEL JACQUELINE
Published: October 2006

If robots are to be truly integrated in humans' everyday environment, they cannot be simply (pre-)designed and directly taken "off the shelf" and embedded into a real-life setting. Also, technical excellence and human-like appearance and "superficial" traits of their behavior are not enough to make social robots trusted, believable, and accepted. Fuller and deeper integration into human environments would require that, like children, robots develop embedded in the social environment in which they will fulfill their roles. An important element to bootstrap and guide this integration is the establishment of affective bonds between the "infant" robot and the adults among whom it develops, from whom it learns, and who it will later have to look after. In this paper, we present a Perception–Action architecture and experiments to simulate imprinting — the establishment of strong attachment links with a "caregiver" — in a robot. Following recent theories, we do not consider imprinting as rigidly timed and irreversible, but as a more flexible phenomenon that allows for further adaptation as a result of reward-based learning through experience. After the initial imprinting, adaptation is achieved in the context of a history of "affective" interactions between the robot and a human, driven by "distress" and "comfort" responses in the robot.
REDUCING THE WAVELET RINGING ARTIFACTS IN A LOW-COMPLEXITY VIDEO CODEC
Authors: HADHOUD MOHIY M. , ISMAIL NABIL A. , TORKEY FAWZY A. , AHMAD MOSTAFA A.
Published: October 2006

A low-complexity wavelet-based video coding technique is proposed which adopts JPEG-2000 image coding. The wavelet transformation and subband quantization are developed and optimized in order to reduce the ringing artifacts especially at very low bit rate. The proposed coding technique reduces the coding complexity and performs well at average PSNR. As compared to other rival coding methods the proposed coding policy has a good compression ratio and an improved visual quality.
Life Among the Axons
Authors: Armstrong Clay M.
Published: October 2006

A blink in history's eye has brought us an understanding of electricity, and with it a revolution in human life. From the frog leg twitch experiments of Galvani and the batteries of Volta, we have progressed to telegraphs, motors, telephones, computers, and the Internet. In the same period, the ubiquitous role of electricity in animal and plant life has become clear. A great milestone in this journey was the elucidation of electrical signaling by Hodgkin & Huxley in 1952. This chapter gives a personal account of a small part of this story, the transformation of the rather abstract electrical conductances of Hodgkin & Huxley into the more tangible gated ion channel.
Not by Spikes Alone: Responses of Coordinating Neurons and the Swimmeret System to Local Differences in Excitation
Authors: Mulloney Brian , Hall Wendy M.
Published: October 2006

Swimmeret coordinating neurons in the crayfish CNS collectively encode a detailed cycle-by-cycle report on features of the motor output to each swimmeret. This information coordinates the motor output that drives swimmeret movements. To see how coordinating neurons responded to forced changes in intersegmental phase, we used a split-bath, repeated-measures experimental design to expose different regions of isolated abdominal nerve cords to different levels of excitation. We present a quantitative description of the firing of power-stroke (PS) motor units and two kinds of coordinating interneurons, ASCEand DSC, recorded simultaneously from each swimmeret ganglion under uniform and nonuniform excitation. When anterior and posterior ganglia were excited differently, several parameters of the swimmeret motor pattern were affected. Strengths of PS bursts in each ganglion were determined by local excitation. The phase of PS bursts in neighboring ganglia changed at the excitation boundary. Coordinating neurons from the two ganglia closest to the excitation boundary were most affected by nonuniform excitation. ASCEneurons tracked the timing and duration of each PS burst in their home ganglion, but did not follow changes in PS burst strength. DSC neurons changed the duration, phase, and number of spikes per burst. We propose two models to explain these results. First, the period expressed under nonuniform conditions is the sum of local intersegmental latencies and these latencies are determined by local excitation. Second, the phase change at the excitation boundary is determined by local modulation of the targets of the intersegmental coordinating neurons, not by modulation of the coordinating neurons themselves.
New Field With Tonotopic Organization in Guinea Pig Auditory Cortex
Authors: Nishimura Masataka , Shirasawa Hiroshi , Kaizo Hiroyuki , Song Wen-Jie
Published: October 2006

In guinea pig auditory cortex, two core areas, a primary area (AI) and a dorsocaudal field (DC), and two belt regions ventral to AI and DC (VRB and VCB) with an intermediate zone (T) in between, together with a small field (S) rostral to AI, have been reported in single-electrode studies although field S and zone T have not been observed in imaging studies. Using a high-resolution in vivo optical-imaging system with the voltage-sensitive dye RH-795, we report here the successful imaging of a rostral small field and zone T and a ventral-to-dorsal frequency gradient in zone T. Further, we found that VRB can be subdivided into two areas, a ventrorostral field (VR) with properties similar to those reported for VRB, and a ventrocaudal field (VC) with novel properties. With increasing stimulus tone frequency, activation in VR shifted caudally while activation in VC shifted rostrally. Thus we have newly identified field VC that has mirror-symmetric tonotopy to that of VR.
Malagasy Primate Origins: Phylogenies, Fossils, and Biogeographic Reconstructions
Authors: Stevens Nancy J. , Heesy Christopher P.
Published: October 2006

The geographic origin of Malagasy primates is a rich source of debate, providing a useful context for understanding effects of differing phylogenetic interpretations upon area of origin reconstructions. This study has evaluated the biogeographic implications of competing primate phylogenies in order to reconstruct the area of origin of Malagasy strepsirhines. The robusticity of biogeographic inference is examined based on sensitivity to tree topology. The results demonstrate extreme vulnerability to both out-group choice and internal tree topology, suggesting caution for area of origin interpretations from phylogenies that exclude fossil taxa. Moreover, even a single taxon can have a powerful effect upon biogeographic interpretations. Perhaps not surprisingly, it is only with greater phylogenetic resolution that a clearer understanding of the biogeographic origins of Malagasy primates will emerge.
Historical Biogeography of the Strepsirhine Primates of Madagascar
Authors: Tattersall Ian
Published: October 2006

Lying some 400 km off the coast of southeastern Africa, Madagascar is the world’s largest oceanic island. It has been in roughly the same position relative to its parent continent for 120 million years, and as a consequence its mammal fauna is unusual in composition, with a low number of major taxa but a high diversity at lower taxonomic levels. Among Madagascar’s native terrestrial mammals, only the orders Primates, Rodentia, Carnivora and Insectivora are represented (plus, until recently, the enigmatic and endemic Bibymalagasia, and Artiodactyla in the form of semiaquatic pygmy hippopotamuses). This reflects the fact that terrestrial mammals are notoriously poor over-water dispersers; yet at the same time the ancestors of all of Madagascar’s mammals had to have crossed a wide oceanic barrier to get to the island at various points during the Tertiary. Here I examine the palaeogeographic evidence for potential land bridge or ‘stepping-stone’ connections with adjacent continents from the Mesozoic through the Cenozoic, and review the fossil records and phylogenies of each of Madagascar’s mammalian groups in an attempt to estimate the minimum number of crossings necessary to produce the island’s current faunal composition. Probable monophyletic origins for each major group, and thus a smaller rather than a larger number of crossings of the Mozambique Channel, imply that this water barrier has acted as a powerful filter; so powerful that it is unclear whether any crossings would have been possible without some form of subaerial connection, however ephemeral, at least from time to time during the Tertiary. Clarification of how Madagascar’s terrestrial mammal fauna may have originated is thus as likely to emerge from the geology of the seafloor surrounding the island as it is to come from the fossil record or from the internal and external relationships of its various components.
Penetrating Head Injury from a Pedestal Fan Rotor Blade in a Child – An Unusual Case
Authors: Kumar Arun , Singh Hukum , Sharma Karam Chand
Published: October 2006

Penetrating head injuries in children constitute only a small part of the total number of traumatic head injuries seen in casualty. A number of household articles have been described to cause penetrating injuries, apart from gunshot and pellet injuries. We describe, for the first time, an unusual case of penetrating injury due to the rotor blade of pedestal fan used very commonly in the Indian subcontinent.
Psychiatric Disorders in Single and Multiple Sexual Murderers
Authors: Hill Andreas , Habermann Niels , Berner Wolfgang , Briken Peer
Published: October 2006

Background: Sexual homicides – and particularly offenders with multiple victims – receive much attention in the general public as well as among forensic experts. The aim of this study was to assess psychiatric disorders in a large sample of sexual murderers and to identify disorders related to multiple sexual homicides. Sampling and Methods: Psychiatric court reports from 20 German forensic psychiatrists on 166 men who had committed a sexual homicide were evaluated for psychiatric disorders according to DSM-IV, including standardized instruments for personality disorders (criteria from the Structured Clinical Interview) and psychopathy (Psychopathy Checklist-Revised). Offenders with a single sexual homicide victim (n = 130) were compared to those with multiple victims (n = 36). Results: High lifetime prevalence rates were found for substance abuse or dependence, paraphilias (especially sexual sadism), sexual dysfunctions and personality disorders (especially antisocial, borderline, sadistic and schizoid). In the multiple sexual murderer group sexual sadism, voyeurism, sadistic, antisocial and schizoid personality disorders were more frequent than in the single-victim group; none of the multiple offenders was diagnosed with a mood disorder. Conclusions and Limitations: Multiple sexual murderers are characterized by disorders in three major psychopathological domains: sexual as well as ‘character’ sadism, antisociality and schizoid personality. A thorough diagnostic evaluation of Axis I as well as Axis II disorders should be part of risk assessments in sexual homicide perpetrators. Although the study was a retrospective investigation on psychiatric court reports, the size of the sample and consistency with results from previous studies give confidence that the identified group differences are unlikely to be due to methodological limitations.
An Upper Bound on the Minimum Number of Monomials Required to Separate Dichotomies of {−1, 1}n
Authors: Oztop Erhan
Published: October 2006

It is known that any dichotomy of {−1, 1}n can be learned (separated) with a higher-order neuron (polynomial function) with 2n inputs (monomials). In general, less than 2n monomials are sufficient to solve a given dichotomy. In spite of the efforts to develop algorithms for finding solutions with fewer monomials, there have been relatively fewer studies investigating maximum density (II(n)), the minimum number of monomials that would suffice to separate an arbitrary dichotomy of {−1, 1}n . This article derives a theoretical (upper) bound for this quantity, superseding previously known bounds. The main theorem here states that for any binary classification problem in {−1, 1}n (n > 1), one can always find a polynomial function solution with 2n −2n/4 or fewer monomials. In particular, any dichotomy of {−1, 1}n can be learned by a higher-order neuron with a fan-in of 2n −2n/4 or less. With this result, for the first time, a deterministic ratio bound independent of n is established as II (n)/2n ≤ 0 75. The main theorem is constructive, so it provides a deterministic algorithm for achieving the theoretical result. The study presented provides the basic mathematical tools and forms the basis for further analyses that may have implications for neural computation mechanisms employed in the cerebral cortex.
The Caenorhabditis elegans P21-activated kinases are differentially required for UNC-6/netrin-mediated commissural motor axon guidance
Authors: Lucanic Mark , Kiley Maureen , Ashcroft Neville , L'Etoile Noelle , Cheng Hwai-Jong
Published: October 2006

P21 activated kinases (PAKs) are major downstream effectors of rac-related small GTPases that regulate various cellular processes. We have identified the new PAK gene max-2 in a screen for mutants disrupted in UNC-6/netrin-mediated commissural axon guidance. There are three Caenorhabditis elegans PAKs. We find that each C. elegansPAK represents a distinct group previously identified in other species. Here we examine their roles in the postembryonic migration of the P cell neuroblasts and the axon guidance of the ventral cord commissural motoneurons(VCCMNs). We find that the two PAKs, max-2 and pak-1, are redundantly required for P cell migration and function with UNC-73/Trio and the rac GTPases (CED-10 and MIG-2). During axon guidance of the VCCMNs, PAK-1 also acts with the rac GTPases, CED-10 and MIG-2, and is completely redundant with MAX-2. Interestingly, we find that unlike MAX-2 activity during P cell migration, for motoneuron axon guidance max-2 is also required in parallel to this PAK-1 pathway, independent of rac GTPase signaling. Finally,we provide evidence that MAX-2 functions downstream of the UNC-6/netrin receptor UNC-5 during axon repulsion and is an integral part of its signaling.
Acute management of laser‐ignited intratracheal explosion
Authors: Schramm Victor L. , Stool Sylvan E. , Mattox Douglas E.
Published: October 2006

The laser‐ignited airway explosion is a shocking emergency. Techniques available for prevention of an airway fire minimize the risk, but they are not applicable in all circumstances. The severity of the patient's injury depends on the duration and intensity of the burn. Prompt, appropriate management is facilitated if the operating team has previously discussed and “rehearsed” this potential disaster. The distal airway burn produced by an ignited endotracheal tube differs from an inhalation burn in character and severity. The anatomic and respiratory effects occurring subsequent to the laser‐induced burn are examined. Emergency care requires immediate elimination of the fire, removal of the tube and any foreign body or debris, and usually a tracheostomy. A program of medical and endoscopic management is suggested.
Aeration of the middle ear and mastoid in tympanoplasty
Authors: Wehrs Roger E.
Published: October 2006

In order to achieve a good hearing result following tympanoplasty it is necessary to maintain an aerated middle ear space. Poor Eustachian tube function is most commonly blamed in cases of failure to obtain an adequately aerated middle ear following tympanoplasty. Although this may be the true etiology in some cases, middle ear adhesions, loss of support of the posterior canal wall and inadvertent blockage of the Eustachian tube orifice by graft material may be contributing factors. Aeration of the mastoidectomy cavity is also important to prevent collapse of the posterior canal wall, retraction pockets and to insure an adequate air reserve.

Surgical techniques for prevention of these complications and a means of bypassing the totally blocked Eustachian tube are discussed.
The argon and CO2 lasers in otolaryngology: Which one, when and why?
Authors: DiBartolomeo Joseph R.
Published: October 2006

Electromagnetic energy in the visible and the infrared range has been recognized as a surgical adjunct for the past two decades. In otolaryngology, the CO2 and argon lasers are now being used in head and neck and otologic surgery. Thermal, non‐ionizing energy is produced by both of these lasers. When an appropriate medium absorbs the electromagnetic radiation carried by either beam, this energy is converted into heat.

Absorption is different for the two wavelengths. The infrared wavelength is efficiently absorbed by water, and since biologic tissue contains 80% water, it is an ideal medium for absorbing infrared radiation. The argon wavelength is in the visible blue‐green spectrum. It is preferentially absorbed by a red medium. When absorption of radiation in the infrared range (CO2) takes place within tissue, the primary effect is vaporization; that produced by the argon laser is photocoagulation.

Unlike any other surgical specialty, the discipline of otolaryngology involves surgery through more orifices, whether man‐made or natural, than any other surgical specialty. In such situations, illumination is frequently inadequate and conventional instruments further obstruct the surgeon's view of the specimen. The use of a “light scalpel” permits alteration of microscopic structures or removal of tissue under direct visualization, especially when the surgical approach is through a limited space. The CO2 laser is an ideal laser for incising, excising, vaporizing or debulking soft tissue masses with precision and good visibility. Because the argon wavelength (.488‐.515 μ) is shorter than that of the CO2 (16.6 μ), it is possible to generate a smaller spot with the argon under similar working conditions. As a visible beam, the argon wavelength is easily transportable by fiber optic light carriers. These two factors make the argon laser more suitable for precise otologic microsurgery. As a soft tissue laser the preferential absorption of Argon radiation by red tissue makes it possible for the first time to eliminate hemangiomatous lesions without physical contact and with minimal disturbance of the overlying skin.
Mutation analysis of CACNA1A and ATP1A2 genes in Brazilian FHM families
Authors: Lopes Luciana R. , Peres Mario Fernando Prieto , Vanmolkot Kaate R.J. , Tobo Patrícia R. , Zukerman Eliova , Frants Rune R. , van den Maagdenberg Arn M.J.M. , Moreira-Filho Carlos Alberto
Published: October 2006

Familial hemiplegic migraine (FHM) is a rare autosomal dominant form of migraine with aura. This disease has been associated with missense mutations in the CACNA1A and ATP1A2 genes. The aim of this study was to identify whether CACNA1A and ATP1A2 are or not related to Brazilian FHM. Here we screened four Brazilian FHM families (total of 26 individuals - 13 affected and 13 asymptomatic or normal) for mutations in both genes. We found an amino acid change in a member of family FHM-D (Arg2206Gly). However since this alteration is not present in all affected individuals and is present in one asymptomatic individual it should be considered a polymorphism. Further studies with additional families will be necessary to reveal the importance of both CACNA1A and ATP1A2 genes on the pathogeneses of FHM in Brazil and to test the third gene (SCN1A) in these FHM families.
CSF markers for diagnosis of bacterial meningitis in neurosurgical postoperative patients
Authors: Tavares Wagner Malagó , Machado Andre Guelman , Matushita Hamilton , Plese Jose Pindaro P.
Published: October 2006

OBJECTIVE: To evaluate the diagnostic usefulness of cerebral spinal fluid (CSF) cellularity, protein, neutrophils, glucose and lactate for detection of postoperative bacterial meningitis. METHOD: This prospective study was conducted in 28 postoperative neurosurgical patients from 2002 to 2005 at University of São Paulo. The CSF markers were plotted in a receiver operating characteristic (ROC) curve to evaluate their accuracy. RESULTS: Based on the area under ROC curve CSF glucose, cellularity, and lactate were considered good tests. Polymorphonuclear and protein did not achieve enough accuracy to be used clinically. CONCLUSION: The CSF glucose, lactate, and cellularity can be used for the diagnosis of bacterial meningitis. Moreover, it can be helpful to differentiate bacterial from aseptic meningitis.
Peripheral neuropathy in patients with hepatitis virus C infection in the Amazon region
Authors: Gomes Irenio , Nora Daniel Bocchese , Marquezini Nelson Cezar , Said Gerard , Melo Ailton
Published: October 2006

INTRODUCTION: Hepatitis virus C (HCV) infection is considered a health problem in the State of Acre localized in the Brazilian Amazon which has a prevalence rate of 5.9%. Peripheral neuropathy is a common extra-hepatic manifestation in patients with HCV. OBJECTIVE: To determine the prevalence of peripheral neuropathies using clinical and neurophysiological parameters. METHOD: A cross sectional study was performed in patients assisted by a specialized center of infectious diseases in the State of Acre. All patients completed a clinicoepidemiological questionnaire, physical examination and nerve conduction studies (NCS). RESULTS: We studied 78 patients with mean age 45.5 years (range from 10 to 76 years), two thirds were male, 51% had at least 8 years of formal education and 96% lived in the capital city of Acre State. Roughly 34% of patients complained about paresthesias mainly in upper limbs. The NCS diagnosed multiple mononeuropathy in 11 (14.1%; IC95% 7.6-23.2) patients and carpal tunnel syndrome in 4 (5.1%) patients. CONCLUSION: Subclinical involvement of peripheral nerves seems common in patients with HCV, with multiple mononeuropathy the main manifestation of nerve injury in this region as suggested by electrophysiological studies.
Isolated velopalatine paralysis associated with parvovirus B19 infection
Authors: Soares-Fernandes João P. , Maré Ricardo
Published: October 2006

A case of isolated velopalatine paralysis in an 8-year-old boy is presented. The symptoms were sudden-onset of nasal speech, regurgitation of liquids into the nose and dysphagia. Brain MRI and cerebrospinal fluid examination were normal. Infectious serologies disclosed an antibody arrangement towards parvovirus B19 that was typical of recent infection. In the absence of other positive data, the possibility of a correlation between the tenth nerve palsy and parvovirus infection is discussed.
Ganglioglioma: comparison with other low-grade brain tumors
Authors: Brainer-Lima Paulo Thadeu , Brainer-Lima Alessandra Mertens , Azevedo-Filho Hildo Rocha
Published: October 2006

METHOD: Forty-two patients with low-grade brain tumor and refractory epilepsy were studied. The mean age was 22.3 years. They were divided into two groups: Group A, patients with ganglioglioma (n=19) and group B, patients with other low-grade tumors (n=23) (14 astrocytoma, 6 oligodendroglioma, 2 dysembryoplastic neuroepithelial tumor, and 1 xanthoastrocytoma). RESULTS: Age at seizure’s onset was 7 years or less in 73% of the patients in group A and in 30.4% of the patients in group B (p=0.045). Complex partial occurred frequently in group A and B (94.7% versus 82%, respectively). Seizure’s frequency was higher in group B (p=0.002).Computerized tomography (CT) was normal in 36.8% of group A patients and abnormal in all group B patients. Magnetic resonance imaging (MRI) was abnormal in all patients. Surgical removal was complete in 89.5% of the patients in group A and in 78.2% of the patients in group B. CONCLUSION: The association of refractory epilepsy and complex partial seizures, at a relatively low frequency, in young patients potentially normal CT and a MRI hypointense temporal lobe lesion in T1-weighed slices were habitual image findings in ganglioglioma, rather than other low-grade tumor.
Abnormalities in auditory evoked potentials of 75 patients with Arnold-Chiari malformations types I and II
Authors: Henriques Filho Paulo Sergio A. , Pratesi Riccardo
Published: October 2006

OBJECTIVE: To evaluate the frequency and degree of severity of abnormalities in the auditory pathways in patients with Chiari malformations type I and II. METHOD: This is a series-of-case descriptive study in which the possible presence of auditory pathways abnormalities in 75 patients (48 children and 27 adults) with Chiari malformation types I and II were analyzed by means of auditory evoked potentials evaluation. The analysis was based on the determination of intervals among potentials peak values, absolute latency and amplitude ratio among potentials V and I. RESULTS: Among the 75 patients studied, 27 (36%) disclosed Arnold-Chiari malformations type I and 48 (64%) showed Arnold-Chiari malformations type II. Fifty-three (71%) of these patients showed some degree of auditory evoked potential abnormalities. Tests were normal in the remaining 22 (29%) patients. CONCLUSION: Auditory evoked potentials testing can be considered a valuable instrument for diagnosis and evaluation of brain stem functional abnormalities in patients with Arnold-Chiari malformations type I and II. The determination of the presence and degree of severity of these abnormalities can be contributory to the prevention of further handicaps in these patients either through physical therapy or by means of precocious corrective surgical intervention.