bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting peak oxygen uptake from submaximal exercise after spinal cord injury
Authors: Totosy de Zepetnek Julia O. , Au Jason S. , Hol Adrienne T. , Eng Janice J. , MacDonald Maureen J.
Published: March 2016

The purpose of this study was to determine the validity of the 6-min arm ergometry test (6MAT) in predicting peak oxygen consumption (V̇O2peak) in individuals with chronic spinal cord injury (SCI). Fifty-two individuals with chronic SCI (age, 38 ± 10 years; American Spinal Injury Association Impairment Scale (AIS), A-D; neurological level of injury (NLI), C1-L2; years post-injury (YPI), 13 ± 10 years) completed an incremental arm ergometry V̇O2peak test and a submaximal 6MAT. Oxygen consumption (V̇O2) data from both tests were used to create a predictive equation with regression analysis. Subsequently, a cross-validation group comprising an additional 10 individuals with SCI (age, 39 ± 13 years; AIS, A-D; NLI, C3-L3; YPI, 9 ± 9 years) were used to determine the predictive power of the equation. All participants were able to complete both the V̇O2peak and 6MAT assessments. Regression analysis yielded the following equation to predict V̇O2peak from end-stage 6MAT V̇O2: V̇O2peak (mL·kg−1·min−1) = 1.501(6MAT V̇O2) – 0.940. Correlation between measured and predicted V̇O2peak was excellent (r = 0.89). No significant difference was found between measured (17.41 ± 7.44 mL·kg−1·min−1) and predicted (17.42 ± 6.61 mL·kg−1·min−1) V̇O2peak (p = 0.97). When cross-validated with a sample of 10 individuals with SCI, correlation between measured and predicted V̇O2peak remained high (r = 0.89), with no differences between measured (18.81 ± 8.35 mL·kg−1·min−1) and predicted (18.73 ± 7.27 mL·kg−1·min−1) V̇O2peak (p = 0.75). Results suggest that 6MAT V̇O2 can be used to predict V̇O2peak among individuals with chronic SCI. The 6MAT should be used as a clinical tool for assessing aerobic capacity when peak exercise testing is not feasible.
Unimodality of Betti numbers for Hamiltonian circle actions with index-increasing moment Maps
Authors: Cho Yunhyung
Published: March 2016

The unimodality conjecture posed by Tolman in [L. Jeffrey, T. Holm, Y. Karshon, E. Lerman and E. Meinrenken, Moment maps in various geometries, http://www.birs.ca/workshops/2005/05w5072/report05w5072.pdf ] states that if [Formula: see text] is a [Formula: see text]-dimensional smooth compact symplectic manifold equipped with a Hamiltonian circle action with only isolated fixed points, then the sequence of Betti numbers [Formula: see text] is unimodal, i.e. [Formula: see text] for every [Formula: see text]. Recently, the author and Kim [Y. Cho and M. Kim, Unimodality of the Betti numbers for Hamiltonian circle action with isolated fixed points, Math. Res. Lett. 21(4) (2014) 691–696] proved that the unimodality holds in eight-dimensional case by using equivariant cohomology theory. In this paper, we generalize the idea in [Y. Cho and M. Kim, Unimodality of the Betti numbers for Hamiltonian circle action with isolated fixed points, Math. Res. Lett. 21(4) (2014) 691–696] to an arbitrary dimensional case. We prove the conjecture in arbitrary dimension under the assumption that the moment map [Formula: see text] is index-increasing, which means that [Formula: see text] implies [Formula: see text] for every pair of critical points [Formula: see text] and [Formula: see text] of [Formula: see text], where [Formula: see text] is the Morse index of [Formula: see text] with respect to [Formula: see text].
A new structure entropy of complex networks based on nonextensive statistical mechanics
Authors: Zhang Qi , Li Meizhu , Deng Yong
Published: March 2016

The quantification of the complexity of network is a fundamental problem in the research of complex networks. There are many methods that have been proposed to solve this problem. Most of the existing methods are based on the Shannon entropy. In this paper, a new method which is based on the nonextensive statistical mechanics is proposed to quantify the complexity of complex network. On the other hand, most of the existing methods are based on a single structure factor, such as the degree of each node or the betweenness of each node. In the proposed method, both of the influence of the degree and betweenness are quantified. In the new method, the degree of each node is used as the constitution of the discrete probability distribution. The betweenness centrality is used as the entropic index q. The nodes which have big value of degree and betweenness will be have big influence on the quantification of network’s structure complexity. In order to describe the relationship between the nodes and the whole network more reasonable, a entropy index set is defined in this new method. Therefore, every node’s influence on the network structure will be quantified. When the value of all the elements in the entropic index set is equal to 1, the new structure entropy is degenerated to the degree entropy. It means that the betweenness of each node in the network is equal to each other. And the structure complexity of the network is determined by the node’s degree distribution. In other words, the new structure entropy is a generalization of the existing degree structure entropy of complex networks. The new structure entropy can be used to quantify the complexity of complex networks, especially for the networks which have a special structure.
A Novel Frame Rate Up-Conversion Algorithm Based on Soft Threshold Bandelet Transform
Authors: Deng Mingjun , Tian Fengchun , Ran Jian , Shi Zhiyong , Zhang Li
Published: March 2016

The most important part of frame rate up-conversion (FRUC) is block matching. The geometric properties of the image were not taken into consideration in traditional block matching algorithm, so the matching result of motion estimation cannot reach the optimal. A novel FRUC algorithm based on Bandelet was proposed in this paper. The algorithm includes: Firstly, a soft threshold Bandelet transform of matching block was performed. The optimal matching block was determined through detection of direction similarity and Bandelet coefficient similarity; secondly, vector median filtering (VMF) and overlapped block motion compensation (OBMC) were carried out by adopting motion vector to realize interpolated frame algorithm. Experimental results show that the FRUC algorithm based on Bandelet can further promote the quality of FRUC.
Artistic Coloring: Color Transfer from Painting
Authors: Wang Xiaohui , Qin Jingyan , Gao Yujiao
Published: March 2016

Color transfer is to alter an image’s color composition by reference to the color characteristics of another image. In this paper, we build a system called artistic coloring that realizes automatic color transfer from famous paintings. It properly extracts the wonderful color characteristics of famous paintings and applies them to color transfer. Specially, we investigate the traditional color theme extraction methods and find their deficiencies. Based on this, we quantify the processing of human painting to find the main colors in the color palette and propose an artistic balanced color theme extraction algorithm aimed specially at paintings. In the experiments, a user study is carried out to evaluate the artistic balanced extraction method. Our proposed method achieves the highest score 3.98 in a 5-point evaluation, which is 41% higher than traditional methods at most. We have successfully tested the artistic coloring system on lots of images with different painting styles. The results are natural and have the similar color characteristics with their corresponding reference paintings.
Vertex-colored graphs, bicycle spaces and Mahler measure
Authors: Lamey Kalyn R. , Silver Daniel S. , Williams Susan G.
Published: March 2016

The space [Formula: see text] of conservative vertex colorings (over a field [Formula: see text]) of a countable, locally finite graph [Formula: see text] is introduced. When [Formula: see text] is connected, the subspace [Formula: see text] of based colorings is shown to be isomorphic to the bicycle space of the graph. For graphs [Formula: see text] with a cofinite free [Formula: see text]-action by automorphisms, [Formula: see text] is dual to a finitely generated module over the polynomial ring [Formula: see text]. Polynomial invariants for this module, the Laplacian polynomials [Formula: see text], are defined, and their properties are discussed. The logarithmic Mahler measure of [Formula: see text] is characterized in terms of the growth of spanning trees.
Estimation of Change Point in Two-Stage Processes Subject to Step Change and Linear Trend
Authors: Amiri Amirhossein , Zolfaghari Samaneh
Published: March 2016

When a control chart signals, it shows the process parameters have changed due to assignable cause(s). However, control chart signal is not the real time of a change in the process. Knowing the real time of change would simplify the detection and elimination of the assignable causes of variation. In this paper, a two-stage process is considered when the mean values of quality characteristics are changed under step shift and linear drift. First, a control chart based on the discriminant analysis (DA) is utilized to monitor the process. Then, when the out-of-control signal is received, the maximum likelihood estimator (MLE) based on the DA statistics, and clustering approach based on Mahalanobis distance of residuals are developed to estimate the real time of the change. The performances of the proposed estimators under different shifts are evaluated through numerical examples and a real case. The results indicate the better performance of the clustering approach rather than the MLE in most cases under both step shift and drift.
MICROSTRUCTURE EVOLUTION AND CORROSION PROPERTY OF MEDIUM-CARBON ALLOY STEEL AFTER HIGH-TEMPERATURE CARBURIZATION PROCESS
Authors: DEWEI DENG , TINGTING NIU , HAIYING LIU , LIN ZHANG , QI SUN
Published: March 2016

In the present study, the effects of carburization treatment on the microstructure and corrosion property of medium-carbon steels (40Cr) were investigated by means of X-ray diffraction (XRD), electron microprobe analyzer (EMPA), optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and electrochemical corrosion, respectively. It was found that the microstructures beneath the surface were refined and a smooth transition microstructure from the surface to the core was observed in carburized samples. The fine plate-like but not granular carbide precipitation (Cr7C3) was observed in carburized sample by heat-treatment. The carburized specimens exhibited some effectiveness in the improvement of hardness and a smooth transition hardness profile. Corrosion resistance of 40Cr was improved by carburization treatment, resulting in the higher self-corrosion potential and the lower self-corrosion current density.
Linear diquasigroups
Authors: Im Bokhee , Matczak K. , Smith J. D. H.
Published: March 2016

Following the prototype of dimonoids, diquasigroups are directed versions of quasigroups, where the structure is split into left and right quasigroups on the same set. The linear and affine diquasigroups that form the topic of this paper are built on the foundation of a module. In this context, various issues that may be difficult to handle in the general case, for example identification of the largest two-sided quasigroup image, become more tractable. An appropriate universal algebraic language for affine diquasigroups is established, and the entropic models of this language are characterized. Various interesting classes of linear and affine diquasigroups are singled out for special attention, such as internally associative, Bol, and symmetric diquasigroups. The problem of determining which linear diquasigroups have an abelian group as their undirected replica is raised. One sufficient condition is provided, formulated in terms of a differential calculus for one-sided quasigroup words.
Gene-set activity toolbox (GAT): A platform for microarray-based cancer diagnosis using an integrative gene-set analysis approach
Authors: Engchuan Worrawat , Meechai Asawin , Tongsima Sissades , Doungpan Narumol , Chan Jonathan H.
Published: March 2016

Cancer is a complex disease that cannot be diagnosed reliably using only single gene expression analysis. Using gene-set analysis on high throughput gene expression profiling controlled by various environmental factors is a commonly adopted technique used by the cancer research community. This work develops a comprehensive gene expression analysis tool (gene-set activity toolbox: (GAT)) that is implemented with data retriever, traditional data pre-processing, several gene-set analysis methods, network visualization and data mining tools. The gene-set analysis methods are used to identify subsets of phenotype-relevant genes that will be used to build a classification model. To evaluate GAT performance, we performed a cross-dataset validation study on three common cancers namely colorectal, breast and lung cancers. The results show that GAT can be used to build a reasonable disease diagnostic model and the predicted markers have biological relevance. GAT can be accessed from http://gat.sit.kmutt.ac.th where GAT’s java library for gene-set analysis, simple classification and a database with three cancer benchmark datasets can be downloaded.
Dynamic Analysis of Partially Filled Non-circular Cylindrical Shells with Liquid Sloshing
Authors: Bochkarev Sergey A. , Lekomtsev Sergey V. , Matveenko Valery P.
Published: March 2016

The paper investigates the dynamic behavior of thin-walled reservoirs containing an ideal liquid taking into account the effects of hydroelastic interaction and sloshing. A mathematical statement of the problem is based on the principle of virtual displacements, which accounts for the pre-stressed non-deformed state of the shell caused by various force factors. The behavior of compressible liquid is described by linearized Euler equations, which are transformed by the Bubnov–Galerkin method. The dynamics of partially filled circular and elliptical cylindrical reservoirs are investigated numerically using a finite element procedure. It has been shown that allowing for sloshing considerably reduces eigenfrequencies of vibrations of the examined systems but has inessential effect on the displacements of the structure under non-stationary loads. Based on the modal analysis we present a classification of eigenmodes of free surface oscillations of a liquid in vertical tanks. It has been found that due to consideration of the sloshing effect, the frequency spectrum of the system can split into two parts in the case when the vibration frequencies of liquid differ from the vibration frequencies of an empty shell. Moreover, under harmonic excitation consideration of liquid sloshing leads to a more complicated amplitude-frequency curve characterized by displacement jumps.
Weighted Reproducing Kernel Collocation Method and Error Analysis for Inverse Cauchy Problems
Authors: Yang Judy P. , Guan Pai-Chen , Fan Chia-Ming
Published: March 2016

In this work, the weighted reproducing kernel collocation method (weighted RKCM) is introduced to solve the inverse Cauchy problems governed by both homogeneous and inhomogeneous second-order linear partial differential equations. As the inverse Cauchy problem is known for the incomplete boundary conditions, how to numerically obtain an accurate solution to the problem is a challenging task. We first show that the weighted RKCM for solving the inverse Cauchy problems considered is formulated in the least-squares sense. Then, we provide the corresponding error analysis to show how the errors in the domain and on the boundary can be balanced with proper weights. The numerical examples demonstrate that the weighted discrete systems improve the accuracy of solutions and exhibit optimal convergence rates in comparison with those obtained by the traditional direct collocation method. It is shown that neither implementation of regularization nor implementation of iteration is needed to reach the desired accuracy. Further, the locality of reproducing kernel approximation gets rid of the ill-conditioned system.
Lateral Crushing of Circular Rings Under Wedge Impact
Authors: Wang Hai-Bo , Yang Jia-Ling , Liu Hua
Published: March 2016

The present work is concerned with the dynamic behavior of a circular ring loaded between a wedge-shaped indenter and a rigid plate. First, an analytical model using the rigid-plastic theory is established. The effects of strain-hardening and strain-rate are incorporated. The history of displacement, velocity and reaction force of the wedge-shaped indenter and energy absorbed by the circular ring are obtained. Further, to verify the proposed analytical model, numerical simulations and experiments are performed and compared with the analytical predictions. It is found that the analytical solutions compare well with the numerical simulations and experiments. This study provides a better understanding of the energy dissipation behavior of circular rings.
Torsional Vibrations of Fluid-Filled Multilayered Transversely Isotropic Finite Circular Cylinder
Authors: Abassi Wafik , El Baroudi Adil , Razafimahery Fulgence
Published: March 2016

An analytical and numerical study for the torsional vibrations of viscous fluid-filled three-layer transversely isotropic cylinder is presented in this paper. The equations of motion of solid and fluid are respectively formulated using the constitutive equations of a transversely isotropic cylinder and the constitutive equations of a viscous fluid. The analytical solution of the frequency equation is obtained using the boundary conditions at the free surface of the solid layer and the boundary conditions at the fluid–solid interface. The frequency equation is deduced and analytically solved using the symbolic Software Mathematica. The finite element method using Comsol Multiphysics Software results are compared with present method for validation and an acceptable match between them were obtained. It is shown that the results from the proposed method are in good agreement with numerical solutions. The influence of fluid dynamic viscosity is thoroughly analyzed and the effect of the isotropic properties on the natural frequencies is also investigated.
An Efficient Finite Element Algorithm in Elastography
Authors: Li Eric , Liao W. H.
Published: March 2016

Elastography is an imaging approach to measure the stiffness of tissues to provide diagnostic information. Currently, finite element method (FEM) has been widely used in elastography. However, FEM tends to an overly stiff model that sometimes gives unsatisfactory accuracy, particularly using triangular elements in 2D or tetrahedral elements in 3D. In general, it is difficult or even impossible to generate quadrilateral or brick elements to precisely capture the anatomic details for mechanobiologic modeling as the biologic system can be rather sophisticated. In addition, biologic soft tissues are often considered as “incompressible” materials, where conventional FEM could suffer from volumetric locking in numerical solution. On the other hand, linear triangular and tetrahedral mesh can be automatically generated for complicated geometry, which significantly saves the time for the creation of model. With these reasons, for the first time, smoothed finite element method (SFEM) is developed to analyze elastography problems. A range of numerical examples, including static, dynamic, viscoelastic and time harmonic cases have exemplified herein to validate that SFEM is able to provide more accurate and stable solutions using the same set of mesh compared with the standard FEM. Furthermore, SFEM is also effective to inversely compute the mechanical properties of abnormal tissue.
Biointerfaces Mediated by Molecular Bonds: Cohesive Behaviors
Authors: Lin Ji , Qian Jin , Yin Jun , Lin Yuan
Published: March 2016

We investigate the cohesive response of biointerfaces mediated by noncovalent receptor–ligand bonding under monotonic, cyclic or other types of loading. By examining the spatiotemporal evolution of the state probability distribution that describes the collective association and dissociation kinetics of interfacial bonds, we show that such interfaces resist the imposed surface separation in a strongly rate-dependent manner. Remarkable hysteresis is exhibited when the interfaces are exposed to single stretching and relaxation cycles at high loading rates, and this hysteretic response shifts in consecutive multiple cycles. There generally exists an optimal ramping velocity that gives rise to the maximum energy dissipation at the interfaces. These results should be useful in understanding the cell-matrix adhesion and de-adhesion phenomena under dynamic and repetitive forces, as well as the adhesion-mediated cellular behaviors such as migration and reorientation.
Hybrid Docking-Nano-QSPR: An Alternative Approach for Prediction of Chemicals Adsorption on Nanoparticles
Authors: Heidari Afsane , Fatemi Mohammad H.
Published: March 2016

In this study, a new hybrid docking-quantitative structure–property relationship (QSPR) methodology was used to model and predict the adsorption coefficients of some small organic compounds on pristine multiwall carbon nanotube (MWCNT). In this method, descriptors are calculated from the reproduced experimental conformations by molecular docking to develop predictive QSPR models. Three MLR models with squared correlation coefficient ([Formula: see text] values of 0.93, 0.94 and 0.95 were selected. The prediction power of models was evaluated on 12-member test set, which was not used during the modeling and led to [Formula: see text] values of 0.88, 0.85 and 0.93. This methodology gives new insight into factors influenced on the adsorption of nanoparticles.
Some properties of power graphs in finite group
Authors: Jafari S. H.
Published: March 2016

The power graph of a group is the graph whose vertex set is the set of nontrivial elements of group, two elements being adjacent if one is a power of the other. We prove some beautiful results in power graphs of finite groups. Then we conclude two finite groups with isomorphic power graphs have the same number of elements of each order from the different way of [P. J. Cameron, The power graph of a finite group II, J. Group Theory 13 (2010) 779–783].
Casimir effect in Podolsky electrodynamics: A functional approach
Authors: Barone F. A. , Nogueira A. A.
Published: March 2016

In this work we study the Podolsky electrodynamics in the presence of conducting surfaces. We calculate the classical interaction between one perfect conducting plate and one point charge. We also consider the interaction between two parallel conducting plates.
Quantum origin of suppression for vacuum fluctuations
Authors: Balitsky Ja. V. , Kiselev V. V.
Published: March 2016

By example of a model with a spatially global scalar field, we show that the energy density of zero-point modes is exponentially suppressed by an average number of field quanta in a finite volume with respect to the energy density in the stationary state of minimal energy. We describe cosmological implications of mechanism.
Dipole-dipole interaction between nanolaser and external atom
Authors: Larionov N. V.
Published: March 2016

We consider the single-emitter nanolaser coupled through dipole-dipole interaction with the external atom placed into the coherent pump field. We show that varying of the coherent pump parameters allows to control the quantum fluctuations of the laser field.
Successful Management of Sequential Pulmonary Infections in a Cardiac Transplant Recipient
Authors: Galbraith John , Preiksaitis Jutta K , Czekanski Sandra , Poznansky Mark J , Hirji Mohamed
Published: March 2016

A case of a cardiac allograft recipient who had an initial combined pulmonary infection with cytomegalovirus, Aspergillus fumigatus and Nocardia asteroides, successfully treated with liposomal amphotericin B and sulfisoxazole and followed by an episode of respiratory syncytial virus pneumonitis, is presented. This case illustrates the role of computed tomographic imaging in the recognition, diagnosis and monitoring of complex opportunistic pulmonary infections and the benefits of liposomal amphotericin B in the treatment of aspergillosis.
A Multistrain Cluster of Methicillin‐Resistant Staphylococcus aureus Based in a Native Community
Authors: Taylor Geoffrey , Kirkland Terri , Kowalewska-Grochowska Kinga , Wang Ying
Published: March 2016

Since 1986 the authors’ hospital has experienced increased numbers of methicillin‐resistant Staphylococcus aureus (MRSA) isolates linked to residents of a native Indian community infected or colonized on admission. A survey of 422 consecutive persons from that community admitted to hospital over a three year period identified 21 (4.9%) carrying MRSA. In a case control study of 34 carriers compared to noncarriers from the community, only prior hospitalization within the past 12 months was identified as being significantly associated with the carrier state, but a specific hospital associated with this risk was not identified. A study of subsets of MRSA isolates in these patients revealed multiple strains present, identified by antibiograms, phage typing profiles and plasmid analysis. Community‐based clusters of MRSA have only rarely been previously identified.
Erythromycin‐Resistant Group G Streptococci in an Isolated Northern Canadian Community
Authors: Nicolle Lindsay , Postl Brian , Urias Barbara , Law Barbara , Ling Norma , Efstratiou Androulla
Published: March 2016

The susceptibility of groups A, C, and G streptococci isolated from pharynx or skin in two northern Canadian native communities during a one year study of the epidemiology of streptococcal infection was determined for penicillin, erythromycin and clindamycin using an agar dilution method. Organisms studied included 725 group A, 82 group C, and 184 group G streptococci. All organisms were susceptible to penicillin (minimum inhibitory concentration [MIC] range less than 0.004 to 0.015 μg/mL; MIC90 0.015 μg/mL) and clindamycin (range 0.007 to 0.06 μg/mL; MIC90 0.06 μg/mL) with no differences observed between streptococcal groups. For erythromycin, groups A and C were generally susceptible (range less than 0.007 to 0.030 μg/mL; MIC90 0.03 μg/mL; and range 0.007 to 1.0 μg/mL; MIC90 0.06 μg/mL, respectively). Group G was less susceptible (range 0.007 to greater than 2.0 μg/mL; MIC90 greater than 2.0 μg/mL) with 38% of all isolates having an MIC greater than or equal to 1 μg/mL. On review of group G isolates, 100 of 100 from one community were susceptible (MIC less than 0.007 to 0.03 μg/mL) and 73 (87%) of 84 from the second community were resistant. All resistant strains tested were type T16. These data suggest that erythromycin‐resistant group G streptococci may occur with high prevalence in certain populations and that patterns of antimicrobial susceptibility in isolated communities may be highly community‐specific.
Heterosexual Transmission of Human Immunodeficiency Virus Infection – Strategies for Prevention
Authors: Conway Brian , Cameron D William , Plummer Francis A , Ronald Allan R
Published: March 2016

In Canada, over 90% of the acquired immune deficiency syndrome cases diagnosed so far have been acquired sexually, with an increasing proportion made up of heterosexual contacts of high risk individuals. In multiple studies, the transmission rate among steady heterosexual partners of infected individuals has been variable. It is likely that complex biological and epidemiological interactions exist between human immunodeficiency virus (HIV) and sexually transmitted diseases with respect to transmission and disease. Other important determinants in transmission of infection may relate to the virus itself. The importance of sexual practices other than vaginal intercourse (such as anal intercourse) in the heterosexual transmission of HIV has not been well studied. The major approach to the control of HIV‐associated disease remains the control of primary infection. Sexual practices which are the major epidemiological determinants of HIV transmission can be successfully modified by appropriate educational interventions. The promotion of condom use must form a special part of these interventions. Results of ongoing trials should be available prior to the formulation of recommendations for the use of spermicides. Targeted education programs may allow us to make better use of our resources in a more efficient way. In Canada, groups that could be reached by such programs include: prostitutes and their clients; men and women attending sexually transmitted disease clinics; sexually active women attending family planning clinics; and children and adolescents who are becoming sexually active.
An Epidemic of Primary Tuberculosis in a Canadian Aboriginal Community
Authors: Mah Manuel W , Fanning Elizabeth Anne
Published: March 2016

In 1987, an outbreak of primary tuberculosis occurred in a Canadian aboriginal community of 350 people. The source case was a young woman who had been symptomatic for four months with smear positive cavitary pulmonary tuberculosis. Her 17 siblings and their families were frequent close contacts. Among the 626 persons surveyed in the community and environs, 35 additional active cases of tuberculosis were identified. The mean age of cases was 13 years and the median age 10 years. The method of diagnosis was bacteriological in 20 and radiological in 16. There were 257 positive tuberculin reactors of whom 120 had no previous record of a positive skin test. Isoniazid prophylaxis was recommended to all new reactors, close household contacts, reactors under the age of 35 years and reactors with lung scars. One late case was identified at one year of follow‐up in a contact who had refused prophylaxis. The rates of infection and disease were higher in the family (65% and 46%, respectively) than in the community and environs (19% and 5.6%, respectively). This report illustrates the nature of a point source epidemic of primary tuberculosis in a susceptible community with a predictable reservoir of infection. The delay in diagnosis of the source case allowed numerous new infections to occur. However, prompt aggressive contact follow‐up was successful in containing the epidemic. To prevent future outbreaks, the reservoir of infected persons must be identified and administered chemoprophylaxis.
Effectiveness and Cost‐Benefit of an Influenza Vaccination Program for Health Care Workers
Authors: Yassi Annalee , Kettner Joel , Hammond Greg , Cheang Mary , McGill Myrna
Published: March 2016

This study retrospectively reviewed the effectiveness of a vaccination program for hospital workers in a large tertiary care hospital, quantified influenza‐induced absenteeism, and examined the factors determining the costs and benefits of this program. Absenteeism among high risk hospital workers was increased by 35% (P=0.001) during the virulent influenza epidemic of 1987–88. Benefits, measured as the value of sick time avoided, compared with costs, including materials, occupational nursing staff time, employee time during vaccination, and time lost due to adverse reactions, revealed a net benefit of $39.23 per vaccinated employee. Sensitivity analyses highlighted vaccine efficacy and absenteeism due to influenza and adverse reactions to vaccination as the most important factors; with time lost due to adverse reactions as much as 0.013 days per vaccinated employee and a vaccine efficacy of 70%, net positive benefits could be achieved if influenza‐induced absenteeism is 0.5% or greater of paid employee time during the epidemic season. The results suggested that the net cost‐benefit of a hospital employee vaccination program to decrease both employee morbidity and nosocomial influenza among patients, would be increased by active promotion of the vaccination program, especially for employees in high risk areas.
Mycobacterial Infections in AIDS
Authors: Hill A Ross
Published: March 2016

Tuberculosis (TB) remains uniquely important among acquired immune deficiency syndrome (AIDS)‐associated opportunistic infections: it presents the greatest public health hazard worldwide, is the most readily curable, and is largely preventable with existing means. Given the expanding pool of human immunodeficiency virus (HIV) seropositive persons, particularly in developing nations where Mycobacterium tuberculosis remains a leading health problem, one can expect a continued rise in TB cases during the 1990s. Global efforts to eliminate TB are now inextricably entwined with the effectiveness of measures to curtail the HIV epidemic. Mycobacterium avium complex infection, currently an intractable late complication of aids, may increase in clinical importance as success in managing other opportunistic infections and HIV disease itself improves. Understanding of the pathogenesis and management of mycobacterial diseases should increase rapidly given the renewed research spurred on by the advent of HIV.
Anti‐Retroviral Strategies for AIDS and Related Diseases
Authors: Wainberg Mark A , Dascal Andre , Mendelson Jack
Published: March 2016

The replication cycle of human immunodeficiency virus type 1 (HIV‐1) and other retroviruses consists of four stages: attachment of the virus to specific receptors on the cell surface; uncoating of the viral nucleic acid and conversion to DNA; production of viral RNA and proteins; and assembly and liberation of progeny virus from the cell. Each of these steps represents a potential target for antiviral chemotherapy. Combinations of drugs which act against different steps in the viral replication cycle might be expected to have synergistic potential. Zidovudine (AZT) is the most widely used drug to date for impeding the replication of HIV‐1. Although AZT therapy has been reasonably successful, it has not been free from toxicity. In addition, there have been several reports of isolation of AZT‐resistant variants of HIV‐1.
Prevalence of Antibody to Hepatitis C Virus in an Isolated Canadian Inuit Settlement
Authors: Minuk GY , Nicolle LE , Gauthier T , Brunka J
Published: March 2016

Sera from 720 inhabitants of Baker Lake, Northwest Territories, a community with high rates of hepatitis A and B infection, were tested for antibody to hepatitis C virus by commercial enzyme‐linked immunosorbent assay. Only two individuals (0.3%) were positive, a 63‐year‐old female and an unrelated 10‐year‐old male. Neither individual was at increased risk of hepatitis C virus exposure. The results of this study indicate that hepatitis C virus infection is no more common in this northern Canadian Inuit settlement than it is in the blood donor population of southern Canada.
The Diagnosis of Epstein‐Barr Virus‐Associated Polymorphic B Cell Lymphoma in Immunocompromised Patients: Review of Methods
Authors: Beauparlant Pierre , Alfieri Caroline , Joncas Jean-Harry
Published: March 2016

Polymorphic B cell lymphoma and diffuse B cell lymphoproliferation associated with Epstein‐Barr virus infection is increasingly reported in immunodeficient patients. Accurate diagnosis of these pathologies is essential because the appropriate treatment regimens for the patients in question differ from those for patients with other lymphoproliferative diseases. Two complementary techniques are currently used in the diagnosis and characterization of Epstein‐Barr virus‐associated B cell lymphomas and diffuse B cell lymphoproliferation. Immunofluorescence allows specific detection of Epstein‐Barr nuclear antigens in lymphomatous tissue. Molecular hybridization with the Bam H1‐W and/or Bam H1‐NJ probes confirms the presence of the Epstein‐Barr virus genome in tumour cells. The Bam H1‐NJ probe is also useful in determining the clonality of the tumour and the replication mode, episomal or linear, of the viral genome. The polymerase chain reaction method allows detection of the Epstein‐Barr virus genome within 24 h in these tumours and is more sensitive.
Cotrimoxazole‐Resistant Escherichia coli Bacteremia in Neutropenic Patients at a Regional Oncology Hospital
Authors: Gregson Daniel B , Matlow Anne G , Simor Andrew E , Tuffnell Peter G , Low Donald E , Feld Ronald , Brunton James E
Published: March 2016

In a regional oncology hospital using cotrimoxazole (trimethoprim‐sulphamethoxazole) prophylaxis during chemotherapy‐induced neutropenia, a single strain of Escherichia coli (indole negative) caused 15 of 27 episodes of Gram‐negative rod bacteremia in 1987, and four of 32 such episodes in 1988. This biotype had not been recovered in 1986. Investigations during this ‘outbreak’ of bacteremias revealed enteric colonization with this strain of E coli in 37% of patients on leukemia or bone marrow transplant wards and in several staff members in July 1987. In 1988, 11 of 32 Gram‐negative rod bacteremias were secondary to other strains of indole positive E coli of several different biotypes and plasmid profiles. Indole negative strains all exhibited low level trimethoprim resistance, whereas indole positive strains which subsequently appeared exhibited high level trimethoprim resistance. Failure of cotrimoxazole prophylaxis was initially due to the clonal dissemination of a single strain of E coli within the institution, with the subsequent appearance of multiple E coli strains with probable differing genetic bases for their resistance.
The Epidemiology of Immune Thrombocytopenia
Authors: Schlech Walter F , Nesdoly Christine , Meagher Nancy , Turner Janet , Dickey Donalda
Published: March 2016

Three cases of immune thrombocytopenia (ITP) associated with human immunodeficiency virus (HIV) infection prompted a review of community‐acquired thrombocytopenia in Nova Scotia from January 1980 to December 1987. Two hundred and seven patients meeting the case definition of ITP were identified. The incidence of ITP rose from 2.0×105 in 1980 to 3.3×105 in 1987. More cases of ITP in the sexually active population occurred between 1984 and 1987 than in the previous four years (P=0.034). All three cases of known HIV associated ITP were captured in the retrospective surveillance system. The study concluded that increases in community‐acquired ITP in a sexually active population may be a surrogate marker of the HIV epidemic, even in geographic areas with a low seroprevalence for HIV. Serological tests for HIV infection should be a routine part of the diagnostic investigation of ITP in all sexually active patients or those with other potential risk factors for HIV infection.
Comparative Activity of Daptomycin and Teicoplanin against Enterococci Isolated from Blood and Urine
Authors: Forward Kevin R , DeGagne Patricia , Bartlett Kathryn R , Harding Godfrey K
Published: March 2016

The authors compared the activity of daptomycin with that of ampicillin, penicillin, teicoplanin and vancomycin against 304 strains of Enterococcus species isolated from blood and urine. Daptomycin was as active as penicillin against Enterococcus faecalis: 90% of strains were inhibited by 2 mg/L. Daptomycin was more active than vancomycin (90% minimal inhibitory concentration [MIC90] 2 mg/L; 90% minimal bactericidal concentration [MBC90] 8 mg/L) but was less active than teicoplanin (MIC50 0.25; MBC90 8 mg/L) or ampicillin (MIC90 1 mg/L; MBC90 2 mg/L) against E faecalis. In time‐kill studies daptomycin was not more rapidly bactericidal than ampicillin or penicillin but was significantly more rapidly bactericidal than either teicoplanin or vancomycin. In combination with gentamicin, daptomycin has activity similar to that of penicillin, vancomycin and teicoplanin. Daptomycin may be a suitable alternative to penicillin in patients allergic to penicillins or for the treatment of enterococcal infections caused by beta‐lactamase‐producing enterococci.
Comparative Antifungal Activity of Cilofungin (LY121019) against Candida Species, Including Evaluation of Susceptibility Testing Method
Authors: Chagla Abdul H , Hii John H , Hoban Daryl J , Simor Andrew E , Ferro Santiago , Witwicki Evelyn , Poon Ruby , Low Donald E
Published: March 2016

The in vitro activity of cilofungin against 100 Candida species was compared with 5‐flucytosine. amphotericin B and ketoconazole by two laboratories independently and in a blinded fashion using a macrotitre dilution broth method in saam-f medium. Cilofungin showed good in vitro activity against Candida albicans. Candida tropicalis and Candida glabrata (90% minimal inhibitory concentration [MIC] 3.2 μg/mL) but was inactive against other Candida species. When testing the susceptibility of cilofungin, 5‐flucytosine and amphotericin B at the two centres, approximately 90% of the Candida strains had MICs differing by fourfold or less. However, when testing susceptibility of ketoconazole, only 51% of the Candida strains had MIC differences fourfold or less. MIC susceptibility testing with cilofungin, 5‐flucytosine and amphotericin B in saam-f medium is reproducible.
Reduction in Clinical Response to Empiric Antimicrobial Therapy of Febrile Granulocytopenic Patients Receiving TMP/SMX Infection Prophylaxis
Authors: Bow Eric J , Pater Joseph L , Louie Thomas J , Feld Ronald , Mandell Lionel , Robson Hugh G , Chow Anthony , Belch Andrew , Miedzinski Lilly , Paul Nancy , Elliott Catherine R , Willan Andrew R
Published: March 2016

In the course of a multicentre clinical trial evaluating two antibacterial regimens for the empiric treatment of suspected infection in febrile neutropenic cancer patients, a suboptimal response was noted among recipients of antibacterial prophylaxis with trimethoprim/sulphamethoxazole (TMP/SMX). Multivariate analysis identified TMP/SMX prophylaxis as a predictor of poor outcome independent of other variables such as classification of infection, marrow recovery, neutrophil count at first fever, indwelling central venous catheter use, and underlying disease. This effect appeared to be restricted to recipients of tobramycin plus ticarcillin (TT). TMP/SMX suppresses potentially pathogenic aerobic Gram‐negative bacilli and allows colonization and subsequent infection by Gram‐positive microorganisms against which TT‐like regimens have limited activity. Recognition of this phenomenon may permit a more appropriate selection of antibacterial agents for the therapy of suspected infection in the neutropenic patient.
Sexually Transmitted Diseases: A Significant Complication of Childhood Sexual Abuse
Authors: Lindsay Deborah , Embree Joanne
Published: March 2016

The acquisition of one or more sexually transmitted diseases (STD) is a significant complication of sexual assault of children. The risk of infection by pathogens varies from less than 1 to 50% depending on the nature of the assault, the organism studied and the background prevalence of STD in the general community. The correct diagnosis of STD in children depends upon optimal collection and appropriate laboratory testing of clinical specimens. Diagnosing STD will allow for treatment and follow‐up to ensure cure of these infections as well as to monitor for re‐infection. It will also help confirm
that sexual activity involving the child has occurred. This can be exi.remely important, particularly when there are minimal other physical findings of abuse or if the child has limited verbal skills and thus cannot
provide a complete disclosure. All physicians who care for children should be knowledgeable about the methods of STD diagnosis and the currently recommended treatment regimens.
Molecular Epidemiological Characterization of Respiratory Isolates of Moraxella catarrhalis in a Pediatric Intensive Care Unit
Authors: Matlow Anne G , Low Donald E , Paret Gideon , Jarrett Scott , Bohn Desmond , Barker Geoffrey , Boulanger Jean , Ford-Jones E Lee
Published: March 2016

A perceived increase in the number of isolates of Moraxella catarrhalis from the respiratory secretions of patients intubated in the pediatric intensive care unit prompted a review of the clinical profiles of such patients and restriction enzyme analysis of the strains involved. Over two months, of 192 patients admitted to the unit, 154 were intubated. Of the 46 for whom endotracheal tube specimens were submitted to the laboratory, M catarrhalis was isolated in 12. M catarrhalis was not felt to be a significant respiratory pathogen by the attending medical staff in any of the patients from whom it was isolated. In only two patients (17%) could nosocomial acquisition be firmly invoked. Restriction enzyme analysis of the 12 strains ruled out the presence of an epidemic strain. Isolation of M catarrhalis from intubated children does not necessarily imply pathogenicity nor an outbreak situation.
Effect of Ribavirin on Hepatitis A Virus Replication In Vitro
Authors: Chaudhary Rabindra K , Andonov Anton P
Published: March 2016

The effect of ribavirin on fetal Rhesus monkey kidney cells (FRhK‐4) acutely or chronically infected with hepatitis A virus was studied. The effect of ribavirin on hepatitis A virus yield as detected by radioimmunoassay in acutely infected FRhK‐4 cells was dependent on hepatitis A virus inoculum dose. Treatment with 100 μg/mL ribavirin completely inhibited hepatitis A virus growth in cultures infected with 100 to 800 tissue culture infectious dose 50 (TCID50) hepatitis A virus, but inocula of 800 to 1600 TCID50 resulted in limited production of virus. The effect was time dependent and required more than 96 h of treatment to inhibit the virus completely. Ribavirin was less effective in treating cells persistently infected with hepatitis A virus, although there was significant inhibition of hepatitis A virus (82%) in persistently infected cells as well. Ribavirin had some inhibitory effect on cell growth; treatment with 25, 50 or 100 μg/mL ribavirin reduced cell growth by approximately 0, 20 and 40%, respectively.
Group C Streptococcal Endocarditis Presenting as Clinical Meningitis: Report of a Case and Review of the Literature
Authors: Huang Allen R , Briedis Dalius J
Published: March 2016

Lancefield group C streptococci are known to be pathogenic in a number of animal species, but cause human disease much less commonly than do streptococci of scrogroups A or B. Reported cases of bacteremic infection, pneumonia or meningitis in humans have been very severe with a grave prognosis. The authors describe a patient who presented with classic clinical and laboratory evidence of bacterial meningitis which proved to be a complication of endocarditis caused by a group C streptococcus. This is the first reported case in which meningitis was the presenting manifestation of group C streptococcal endocarditis and is only the second case in which group C streptococcal meningitis and endocarditis have been associated in the same patient. A total of 13 cases of group C streptococcal meningitis have now been reported in the medical literature. Five of these patients died, and four others recovered only to be left with neurological sequelae. The current case confirms the seriousness of group C streptococcal infections in humans. Such infections are associated with a poor prognosis despite apparently adequate antimicrobial therapy.
De Novo Subgaleal Abscess
Authors: Schaefer JP , Clein LJ , Conly JM
Published: March 2016

The authors report a case of spontaneous subgaleal abscess formation in a 62‐year‐old woman without antecedent trauma or injury. She presented with occipital scalp pain and swelling which rapidly became generalized two days following recovery from an upper respiratory infection. Diagnosis was based on radiological examination and aspiration of the subgaleal space, which yielded a purulent exudate with a pure growth of Streptococcus pyogenes. Initial management with incision, drainage and parenteral antimicrobial therapy was not successful. Operative exploration of the subgaleal space revealed extensive necrosis of the galea aponeurotica, and bone curettings revealed microscopic evidence compatible with osteomyelitis. Management with debridement and excision of all necrotic tissue plus prolonged parenteral antimicrobials was successful. Subgaleal abscess formation without an overlying wound or previous trauma has not been reported previously.