bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer‐aided detection of lung nodules via 3D fast radial transform, scale space representation, and Zernike MIP classification
Authors: Riccardi Alessandro , Petkov Todor Sergueev , Ferri Gianluca , Masotti Matteo , Campanini Renato
Published: April 2011

Purpose:

The authors presented a novel system for automated nodule detection in lung CT exams.

Methods:

The approach is based on (1) a lung tissue segmentation preprocessing step, composed of histogram thresholding, seeded region growing, and mathematical morphology; (2) a filtering step, whose aim is the preliminary detection of candidate nodules (via 3D fast radial filtering) and estimation of their geometrical features (via scale space analysis); and (3) a false positive reduction (FPR) step, comprising a heuristic FPR, which applies thresholds based on geometrical features, and a supervised FPR, which is based on support vector machines classification, which in turn, is enhanced by a feature extraction algorithm based on maximum intensity projection processing and Zernike moments.

Results:

The system was validated on 154 chest axial CT exams provided by the lung image database consortium public database. The authors obtained correct detection of 71% of nodules marked by all radiologists, with a false positive rate of 6.5 false positives per patient (FP/patient). A higher specificity of 2.5 FP/patient was reached with a sensitivity of 60%. An independent test on the ANODE09 competition database obtained an overall score of 0.310.

Conclusions:

The system shows a novel approach to the problem of lung nodule detection in CT scans: It relies on filtering techniques, image transforms, and descriptors rather than region growing and nodule segmentation, and the results are comparable to those of other recent systems in literature and show little dependency on the different types of nodules, which is a good sign of robustness.
Evaluation of intersession 3D‐TRUS to 3D‐TRUS image registration for repeat prostate biopsies
Authors: Karnik V. V. , Fenster A. , Bax J. , Romagnoli C. , Ward A. D.
Published: April 2011

Purpose:

3D‐TRUS‐guided prostate biopsy permits a 3D record of biopsy cores, supporting the planning of targets to resample or avoid during repeat biopsy sessions. Image registration is required in order to map biopsy targets planned on a previous session's 3D‐TRUS image into the context of the current session. The authors evaluated the performance of surface‐ and intensity‐based rigid and nonrigid registration algorithms for this task using a clinically motivated success criterion of a maximum 2.5 mm target registration error (TRE).

Methods:

The authors collected two 3D‐TRUS images for each of 13 patients, where each image was collected in a separate biopsy session, and the sessions were 1 week apart. The authors tested the iterative closest point and thin‐plate spline surface‐based registration methods, and the block matching and B‐spline intensity‐based methods. Manually marked intrinsic fiducials (calcifications) were used to calculate a TRE for each of the tested methods. In addition, error ellipsoids, anisotropy, and variability due to image segmentation were analyzed. All analysis was performed separately for the peripheral zone since this area harbors up to 80% of all prostate cancer.

Results:

Only the intensity‐based nonrigid registration method met the success criterion for both the whole gland and the peripheral zone. Segmentation was a substantial contributor to registration error variability for the surface‐based methods, and the surface‐based methods resulted in greater error volumes and anisotropy.

Conclusions:

Intensity‐based rigid registration is clinically sufficient to register regions outside the peripheral zone, but nonrigid registration is required in order to register the peripheral zone with clinically needed accuracy. The clinical advantage of using nonrigid registration is questionable since the difference between the RMS TREs for rigid and nonrigid intensity‐based registration could be considered to be small (0.3 mm) and is statistically significant. If the added clinical value in performing a nonrigid registration is insufficient given the additional time required for this computation, rigid registration alone may be suitable.
Development and evaluation of a computer‐aided diagnostic scheme for lung nodule detection in chest radiographs by means of two‐stage nodule enhancement with support vector classification
Authors: Chen Sheng , Suzuki Kenji , MacMahon Heber
Published: April 2011

Purpose:

To develop a computer‐aided detection (CADe) scheme for nodules in chest radiographs (CXRs) with a high sensitivity and a low false‐positive (FP) rate.

Methods:

The authors developed a CADe scheme consisting of five major steps, which were developed for improving the overall performance of CADe schemes. First, to segment the lung fields accurately, the authors developed a multisegment active shape model. Then, a two‐stage nodule‐enhancement technique was developed for improving the conspicuity of nodules. Initial nodule candidates were detected and segmented by using the clustering watershed algorithm. Thirty‐one shape‐, gray‐level‐, surface‐, and gradient‐based features were extracted from each segmented candidate for determining the feature space, including one of the new features based on the Canny edge detector to eliminate a major FP source caused by rib crossings. Finally, a nonlinear support vector machine (SVM) with a Gaussian kernel was employed for classification of the nodule candidates.

Results:

To evaluate and compare the scheme to other published CADe schemes, the authors used a publicly available database containing 140 nodules in 140 CXRs and 93 normal CXRs. The CADe scheme based on the SVM classifier achieved sensitivities of 78.6% (110/140) and 71.4% (100/140) with averages of 5.0 (1165/233) FPs/image and 2.0 (466/233) FPs/image, respectively, in a leave‐one‐out cross‐validation test, whereas the CADe scheme based on a linear discriminant analysis classifier had a sensitivity of 60.7% (85/140) at an FP rate of 5.0 FPs/image. For nodules classified as “very subtle” and “extremely subtle,” a sensitivity of 57.1% (24/42) was achieved at an FP rate of 5.0 FPs/image. When the authors used a database developed at the University of Chicago, the sensitivities was 83.3% (40/48) and 77.1% (37/48) at an FP rate of 5.0 (240/48) FPs/image and 2.0 (96/48) FPs /image, respectively.

Conclusions:

These results compare favorably to those described for other commercial and noncommercial CADe nodule detection systems.
Characterization of lamina propria and vocal muscle in human vocal fold tissue by ultrasound Nakagami imaging
Authors: Tsui Po‐Hsiang , Huang Chih‐Chung , Sun Lei , Dailey Seth H. , Shung K. Kirk
Published: April 2011

Purpose:

A number of ultrasound techniques have been applied to identify the biomechanical properties of the vocal folds. These conventional ultrasound methods, however, are not capable of visually mapping the concentration of collagen and elastic fibers in the vocal folds in the form of a parametric image. This study proposes to use a statistical parameter, the Nakagami factor estimated from the statistical distribution of the ultrasonic signals backscattered from tissues, as a means for parametric imaging of the biomechanical properties of the vocal folds.

Methods:

The ultrasonic backscattered signals were acquired from four larynges (eight vocal folds) obtained from individuals without vocal fold pathology for constructing the Nakagami images. The textures of the Nakagami image in the lamina propria (LP) and the vocal muscle (VM) were observed and compared. The average and standard deviation of the Nakagami parameter for the LP and the VM were also calculated.

Results:

The results showed that the Nakagami parameter of the LP is larger than that of the VM. Moreover, the LP and the VM have different shading features in the Nakagami images. It was found that the Nakagami parameter may depend on the concentration of collagen and elastic fibers, demonstrating that the Nakagami imaging may allow visual differentiation between the LP and the VM in the vocal folds.

Conclusions:

Current preliminary results suggested that the high‐frequency Nakagami imaging may allow real‐time visual characterization of the vocal fold tissues in clinical routine examinations.
Comparative performance of multiview stereoscopic and mammographic display modalities for breast lesion detection
Authors: Webb Lincoln J. , Samei Ehsan , Lo Joseph Y. , Baker Jay A. , Ghate Sujata V. , Kim Connie , Soo Mary Scott , Walsh Ruth
Published: April 2011

Purpose:

Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true lesion and the inability to derive volumetric information. It has been shown that stereomammography can overcome these deficiencies by showing that layers of normal tissue lay at different depths. If standard stereomammography (i.e., a single stereoscopic pair consisting of two projection images) can significantly improve lesion detection, how will multiview stereoscopy (MVS), where many projection images are used, compare to mammography? The aim of this study was to assess the relative performance of MVS compared to mammography for breast mass detection.

Methods:

The MVS image sets consisted of the 25 raw projection images acquired over an arc of approximately 45° using a Siemens prototype breast tomosynthesis system. The mammograms were acquired using a commercial Siemens FFDM system. The raw data were taken from both of these systems for 27 cases and realistic simulated mass lesions were added to duplicates of the 27 images at the same local contrast. The images with lesions (27 mammography and 27 MVS) and the images without lesions (27 mammography and 27 MVS) were then postprocessed to provide comparable and representative image appearance across the two modalities. All 108 image sets were shown to five full‐time breast imaging radiologists in random order on a state‐of‐the‐art stereoscopic display. The observers were asked to give a confidence rating for each image (0 for lesion definitely not present, 100 for lesion definitely present). The ratings were then compiled and processed using ROC and variance analysis.

Results:

The mean AUC for the five observers was for mammography and for multiview stereoscopy. The difference of was statistically significant with a ‐value of 0.0148.

Conclusions:

The differences in the AUCs and the ‐value suggest that multiview stereoscopy has a statistically significant advantage over mammography in the detection of simulated breast masses. This highlights the dominance of anatomical noise compared to quantum noise for breast mass detection. It also shows that significant lesion detection can be achieved with MVS without any of the artifacts associated with tomosynthesis.
Water equivalent path length measurement in proton radiotherapy using time resolved diode dosimetry
Authors: Gottschalk B. , Tang S. , Bentefour E. H. , Cascio E. W. , Prieels D. , Lu H.‐M.
Published: April 2011

Purpose:

To verify water equivalent path length (WEPL) before treatment in proton radiotherapy using time resolvedin vivo diode dosimetry.

Methods:

Using a passively scattered range modulated proton beam, the output of a diode driving a fast current‐to‐voltage amplifier is recorded at a number of depths in a water tank. At each depth, a burst of overlapping single proton pulses is observed. The rms duration of the burst is computed and the resulting data set is fitted with a cubic polynomial.

Results:

When the diode is subsequently set to an arbitrary depth and the polynomial is used as a calibration curve, the “unknown” depth is determined within 0.3 mm rms.

Conclusions:

A diode or a diode array, placed (for instance) in the rectum in conjunction with a rectal balloon, can potentially determine the WEPL at that point, just prior to treatment, with submillimeter accuracy, allowing the beam energy to be adjusted. The associated unwanted dose is about 0.2% of a typical single fraction treatment dose.
Method for measuring the focal spot size of an x‐ray tube using a coded aperture mask and a digital detector
Authors: Russo Paolo , Mettivier Giovanni
Published: April 2011

Purpose:

The goal of this study is to evaluate a new method based on a coded aperture mask combined with a digital x‐ray imaging detector for measurements of the focal spot sizes of diagnostic x‐ray tubes. Common techniques for focal spot size measurements employ a pinhole camera, a slit camera, or a star resolution pattern. The coded aperture mask is a radiation collimator consisting of a large number of apertures disposed on a predetermined grid in an array, through which the radiation source is imaged onto a digital x‐ray detector. The method of the coded mask camera allows one to obtain a one‐shot accurate and direct measurement of the two dimensions of the focal spot (like that for a pinhole camera) but at a low tube loading (like that for a slit camera). A large number of small apertures in the coded mask operate as a “multipinhole” with greater efficiency than a single pinhole, but keeping the resolution of a single pinhole.

Methods:

X‐ray images result from the multiplexed output on the detector image plane of such a multiple aperture array, and the image of the source is digitally reconstructed with a deconvolution algorithm. Images of the focal spot of a laboratory x‐ray tube (W anode: 35–80 kVp; focal spot size of 0.04 mm) were acquired at different geometrical magnifications with two different types of digital detector (a photon counting hybrid silicon pixel detector with 0.055 mm pitch and a flat panel CMOS digital detector with 0.05 mm pitch) using a high resolution coded mask (type no‐two‐holes‐touching modified uniformly redundant array) with 480 0.07 mm apertures, designed for imaging at energies below 35 keV. Measurements with a slit camera were performed for comparison. A test with a pinhole camera and with the coded mask on a computed radiography mammography unit with 0.3 mm focal spot was also carried out.

Results:

The full width at half maximum focal spot sizes were obtained from the line profiles of the decoded images, showing a focal spot of at 35 kVp and , with a detector entrance exposure as low as 1.82 mR (0.125 mA s tube load). The slit camera indicated a focal spot of at 35 kVp and , with an exposure at the detector of 72 mR. Focal spot measurements with the coded mask could be performed up to 80 kVp. Tolerance to angular misalignment with the reference beam up to 7° in in‐plane rotations and 1° deg in out‐of‐plane rotations was observed. The axial distance of the focal spot from the coded mask could also be determined. It is possible to determine the beam intensity via measurement of the intensity of the decoded image of the focal spot and via a calibration procedure.

Conclusions:

Coded aperture masks coupled to a digital area detector produce precise determinations of the focal spot of an x‐ray tube with reduced tube loading and measurement time, coupled to a large tolerance in the alignment of the mask.
Commissioning of output factors for uniform scanning proton beams
Authors: Zheng Yuanshui , Ramirez Eric , Mascia Anthony , Ding Xiaoning , Okoth Benny , Zeidan Omar , Hsi Wen , Harris Ben , Schreuder Andries N. , Keole Sameer
Published: April 2011

Purpose:

Current commercial treatment planning systems are not able to accurately predict output factors and calculate monitor units for proton fields. Patient‐specific field output factors are thus determined by either measurements or empirical modeling based on commissioning data. The objective of this study is to commission output factors for uniform scanning beams utilized at the ProCure proton therapy centers.

Methods:

Using water phantoms and a plane parallel ionization chamber, the authors first measured output factors with a fixed 10 cm diameter aperture as a function of proton range and modulation width for clinically available proton beams with ranges between 4 and 31.5 cm and modulation widths between 2 and 15 cm. The authors then measured the output factor as a function of collimated field size at various calibration depths for proton beams of various ranges and modulation widths. The authors further examined the dependence of the output factor on the scanning area (i.e., uncollimated proton field), snout position, and phantom material. An empirical model was developed to calculate the output factor for patient‐specific fields and the model‐predicted output factors were compared to measurements.

Results:

The output factor increased with proton range and field size, and decreased with modulation width. The scanning area and snout position have a small but non‐negligible effect on the output factors. The predicted output factors based on the empirical modeling agreed within 2% of measurements for all prostate treatment fields and within 3% for 98.5% of all treatment fields.

Conclusions:

Comprehensive measurements at a large subset of available beam conditions are needed to commission output factors for proton therapy beams. The empirical modeling agrees well with the measured output factor data. This investigation indicates that it is possible to accurately predict output factors and thus eliminate or reduce time‐consuming patient‐specific output measurements for proton treatments.
Differences in Thermal Tolerance Among Sockeye Salmon Populations
Authors: Eliason Erika J. , Clark Timothy D. , Hague Merran J. , Hanson Linda M. , Gallagher Zoë S. , Jeffries Ken M. , Gale Marika K. , Patterson David A. , Hinch Scott G. , Farrell Anthony P.
Published: March 2011

Environmental conditions encountered during migration shape cardiorespiratory physiology in sockeye salmon.
Perception of UV-B by the
Arabidopsis
UVR8 Protein
Authors: Rizzini Luca , Favory Jean-Jacques , Cloix Catherine , Faggionato Davide , O’Hara Andrew , Kaiserli Eirini , Baumeister Ralf , Schäfer Eberhard , Nagy Ferenc , Jenkins Gareth I. , Ulm Roman
Published: March 2011

A plant ultraviolet-B photoreceptor uses a tryptophan-based chromophore.
Economic Importance of Bats in Agriculture
Authors: Boyles Justin G. , Cryan Paul M. , McCracken Gary F. , Kunz Thomas H.
Published: March 2011

Insectivorous bat populations, adversely impacted by white-nose syndrome and wind turbines, may be worth billions of dollars to North American agriculture.
Microtomography of Partially Molten Rocks: Three-Dimensional Melt Distribution in Mantle Peridotite
Authors: Zhu Wenlu , Gaetani Glenn A. , Fusseis Florian , Montési Laurent G. J. , De Carlo Francesco
Published: March 2011

As mantle rocks melt, an interconnected network of liquid drives the ascent of magma to the sea floor.
Electrochemically Mediated Atom Transfer Radical Polymerization
Authors: Magenau Andrew J. D. , Strandwitz Nicholas C. , Gennaro Armando , Matyjaszewski Krzysztof
Published: March 2011

The structure of a polymer can be fine-tuned by rapidly starting and stopping its synthesis.
Protective Immunity against Experimental Pulmonary Cryptococcosis in T Cell-Depleted Mice
Authors: Wozniak Karen L. , Young Mattie L. , Wormley Floyd L.
Published: March 2011

Individuals with defects in T cell-mediated immunity (CMI) are highly susceptible to infection withCryptococcus neoformans. The purpose of these studies was to determine if protection against experimental pulmonary cryptococcosis can be generated in T cell-deficient hosts. BALB/c mice were depleted of CD4+and/or CD8+T cells or given an isotype control antibody prior to vaccination with aC. neoformansstrain, designated H99γ, previously shown to induce protection againstC. neoformansinfection in immunocompetent mice. Mice depleted of CD4+or CD8+T cells, but not both subsets, survived an acute pulmonary infection withC. neoformansstrain H99γ and a subsequent second challenge with wild-typeC. neoformansstrain H99. We observed a significant increase in the percentage of CD4+and CD8+T cells expressing the activation marker CD69 in the lungs of mice immunized withC. neoformansstrain H99γ prior to a secondary challenge with wild-type cryptococci. CD4+T cells within the lungs of immunized mice also appeared to acquire a predominantly activated effector memory cell phenotype (CD69+CD44+CCR7−CD45RB−CD62L−) following a second pulmonary challenge with wild-typeC. neoformans, compared to CD4+T cells from naïve mice. Lastly, immunization of immunocompetent mice withC. neoformansstrain H99γ prior to depletion of CD4+and/or CD8+T cells resulted in significant protection against a second challenge with wild-typeC. neoformans. Our studies demonstrate that protective immunity against pulmonary cryptococcosis can be generated in immunosuppressed hosts, thus supporting the development of cryptococcal vaccines.
Characterization of Invasive Pneumococci of Serogroup 6 from Adults in Barcelona, Spain, in 1994 to 2008
Authors: Rolo Dora , Ardanuy Carmen , Calatayud Laura , Pallares Román , Grau Immaculada , García Ernesto , Fenoll Asunción , Martín Rogelio , Liñares Josefina
Published: March 2011

A total of 91 of 1,480 invasive isolates (6.1%) collected from adults in Barcelona, Spain, in the period of 1994 to 2008 were of serogroup 6 (6B, 47 isolates; 6A, 28; and 6C, 16). Throughout this period, serotype 6B (Spain
6B
-ST90) decreased, and serotype 6A remained stable. An increase in serotype 6C (ST224) in the 2004-2008 period was observed.
Web-Accessible Database of
hsp65
Sequences from Mycobacterium Reference Strains
Authors: Dai Jianli , Chen Yuansha , Lauzardo Michael
Published: March 2011

Mycobacteria include a large number of pathogens. Identification to species level is important for diagnoses and treatments. Here, we report the development of a Web-accessible database of the
hsp65
locus sequences (
http://msis.mycobacteria.info
) from 149 out of 150
Mycobacterium
species/subspecies. This database can serve as a reference for identifying
Mycobacterium
species.
Antibody-Dependent Cell-Mediated Viral Inhibition Emerges after Simian Immunodeficiency Virus SIVmac251 Infection of Rhesus Monkeys Coincident with gp140-Binding Antibodies and Is Effective against Neutralization-Resistant Viruses
Authors: Asmal Mohammed , Sun Yue , Lane Sophie , Yeh Wendy , Schmidt Stephen D. , Mascola John R. , Letvin Norman L.
Published: March 2011

Antibody-dependent cell-mediated viral inhibition (ADCVI) is an attractive target for vaccination because it takes advantage of both the anamnestic properties of an adaptive immune response and the rapid early response characteristics of an innate immune response. Effective utilization of ADCVI in vaccine strategies will depend on an understanding of the natural history of ADCVI during acute and chronic human immunodeficiency virus type 1 (HIV-1) infection. We used the simian immunodeficiency virus (SIV)-infected rhesus monkey as a model to study the kinetics of ADCVI in early infection, the durability of ADCVI through the course of infection, and the effectiveness of ADCVI against viruses with envelope mutations that are known to confer escape from antibody neutralization. We demonstrate the development of ADCVI, capable of inhibiting viral replication 100-fold, within 3 weeks of infection, preceding the development of a comparable-titer neutralizing antibody response by weeks to months. The emergence of ADCVI was temporally associated with the emergence of gp140-binding antibodies, and in most animals, ADCVI persisted through the course of infection. Highly evolved viral envelopes from viruses isolated at late time points following infection that were resistant to plasma neutralization remained susceptible to ADCVI, suggesting that the epitope determinants of neutralization escape are not shared by antibodies that mediate ADCVI. These findings suggest that despite the ability of SIV to mutate and adapt to multiple immunologic pressures during the course of infection, SIV envelope may not escape the binding of autologous antibodies that mediate ADCVI.
The Cellular Factors Vps18 and Mon2 Are Required for Efficient Production of Infectious HIV-1 Particles
Authors: Tomita Yuriko , Noda Takeshi , Fujii Ken , Watanabe Tokiko , Morikawa Yuko , Kawaoka Yoshihiro
Published: March 2011

Like all viruses, HIV-1 requires cellular host factors for replication. The mechanisms for production of progeny virions involving these host factors, however, are not fully understood. To better understand these mechanisms, we used a yeast (
Saccharomyces cerevisiae
) genetic screen to identify mutant strains in which HIV-1 Gag targeting to the plasma membrane was aberrant. Of the 917 mutants identified, we selected 14 mutants whose missing genes had single orthologous counterparts in human and tested them for Gag-induced viruslike particle (VLP) release in yeast cells. We found that the Vps18 and Mon2 proteins were important for HIV-1 Gag-induced VLP release in yeast. In eukaryote cells, these host proteins are highly conserved and function in protein trafficking. Depletion of hVps18 or hMon2 reduced the efficient production of infectious HIV-1 virions in human cells. Our data suggest that these cellular factors play an important role in the efficient production of infectious HIV-1 virion particles.
Adaptation of an ICAM-1-Tropic Enterovirus to the Mouse Respiratory Tract
Authors: Wang Eric S. , Dobrikova Elena , Goetz Christian , Dufresne Andrew T. , Gromeier Matthias
Published: March 2011

Respiratory tract (RT) infections by members of the enterovirus (EV) genus of the
Picornaviridae
family are the most frequent cause for the common cold and a major factor in the exacerbation of chronic pulmonary diseases. The lack of a practical small-animal model for these infections has obstructed insight into pathogenic mechanisms of the common cold and their role in chronic RT illness and has hampered preclinical evaluation of antiviral strategies. Despite significant efforts, it has been difficult to devise rodent models that exhibit viral replication in the RT. This is due mainly to well-known intracellular host restrictions of EVs with RT tropism in rodent cells. We report the evolution of variants of the common-cold-causing coxsackievirus A21, an EV with tropism for the human intercellular adhesion molecule 1 (hICAM-1), through serial passage in the lungs of mice transgenic for the
hICAM-1
gene. This process was accompanied by multiple changes in the viral genome, suggesting exquisite adaptation of hICAM-1-tropic enteroviruses to the specific growth conditions within the RT.
In vivo
mouse RT-adapted, variant coxsackievirus A21 exhibited replication competence in the lungs of
hICAM-1
transgenic mice, providing a basis for unraveling EV-host interactions in the mouse RT.
Three Amino Acid Mutations (F51L, T59A, and S390L) in the Capsid Protein of the Hepatitis E Virus Collectively Contribute to Virus Attenuation
Authors: Córdoba Laura , Huang Yao-Wei , Opriessnig Tanja , Harral Kylie K. , Beach Nathan M. , Finkielstein Carla V. , Emerson Suzanne U. , Meng Xiang-Jin
Published: March 2011

Hepatitis E virus (HEV) is an important but extremely understudied human pathogen, and the mechanisms of HEV replication and pathogenesis are largely unknown. We previously identified an attenuated genotype 3 HEV mutant (pSHEV-1) containing three unique amino acid mutations (F51L, T59A, and S390L) in the capsid protein. To determine the role of each of these mutations, we constructed three HEV single mutants (rF51L, rT59A, and rS390L) which were all found to be replication competent in Huh7 liver cells. To determine the pathogenicities of the mutants, we utilized the specific-pathogen-free (SPF) pig model for HEV and a unique inoculation procedure that bypasses the need for propagating infectious HEV
in vitro
. A total of 60 pigs were intrahepatically inoculated, via an ultrasound-guided technique, with
in vitro
-transcribed full-length capped RNA transcripts from the infectious clones of each single mutant, the pSHEV-1 triple mutant, wild-type pSHEV-3, or phosphate-buffered saline (PBS) buffer (
n
= 10). The results showed that the F51L mutation partially contributed to virus attenuation, whereas the T59A and S390L mutations resulted in more drastic attenuation of HEV in pigs, as evidenced by a significantly lower incidence of viremia, a delayed appearance and shorter duration of fecal virus shedding and viremia, and lower viral loads in liver, bile, and intestinal content collected at three different necropsy times. The results indicate that the three mutations in the capsid protein collectively contribute to HEV attenuation. This study has important implications for developing a modified live-attenuated vaccine against HEV.
Oncolytic Vesicular Stomatitis Virus Induces Apoptosis in U87 Glioblastoma Cells by a Type II Death Receptor Mechanism and Induces Cell Death and Tumor Clearance In Vivo
Authors: Cary Zachary D. , Willingham Mark C. , Lyles Douglas S.
Published: March 2011

Vesicular stomatitis virus (VSV) is a potential oncolytic virus for treating glioblastoma multiforme (GBM), an aggressive brain tumor. Matrix (M) protein mutants of VSV have shown greater selectivity for killing GBM cells versus normal brain cells than VSV with wild-type M protein. The goal of this research was to determine the contribution of death receptor and mitochondrial pathways to apoptosis induced by an M protein mutant (M51R) VSV in U87 human GBM tumor cells. Compared to controls, U87 cells expressing a dominant negative form of Fas (dnFas) or overexpressing Bcl-X
L
had reduced caspase-3 activation following infection with M51R VSV, indicating that both the death receptor pathway and mitochondrial pathways are important for M51R VSV-induced apoptosis. Death receptor signaling has been classified as type I or type II, depending on whether signaling is independent (type I) or dependent on the mitochondrial pathway (type II). Bcl-X
L
overexpression inhibited caspase activation in response to a Fas-inducing antibody, similar to the inhibition in response to M51R VSV infection, indicating that U87 cells behave as type II cells. Inhibition of apoptosis
in vitro
delayed, but did not prevent, virus-induced cell death. Murine xenografts of U87 cells that overexpress Bcl-X
L
regressed with a time course similar to that of control cells following treatment with M51R VSV, and tumors were not detectable at 21 days postinoculation. Immunohistochemical analysis demonstrated similar levels of viral antigen expression but reduced activation of caspase-3 following virus treatment of Bcl-X
L
-overexpressing tumors compared to controls. Further, the pathological changes in tumors following treatment with virus were quite different in the presence versus the absence of Bcl-X
L
overexpression. These results demonstrate that M51R VSV efficiently induces oncolysis in GBM tumor cells despite deregulation of apoptotic pathways, underscoring its potential use as a treatment for GBM.
Pivotal Role of Antibody and Subsidiary Contribution of CD8+T Cells to Recovery from Infection in a Murine Model of Japanese Encephalitis
Authors: Larena Maximilian , Regner Matthias , Lee Eva , Lobigs Mario
Published: March 2011

The immunological correlates for recovery from primary Japanese encephalitis virus (JEV) infection in humans and experimental animals remain poorly defined. To investigate the relative importance of the adaptive immune responses, we have established a mouse model for Japanese encephalitis in which a low-dose virus inoculum was administered into the footpads of adult C57BL/6 mice. In this model, ∼60% of the mice developed a fatal encephalitis and a virus burden in the central nervous system (CNS). Using mice lacking B cells (μMT−/−mice) and immune B cell transfer to wild-type mice, we show a critically important role for humoral immunity in preventing virus spread to the CNS. T cell help played an essential part in the maintenance of an effective antibody response necessary to combat the infection, since mice lacking major histocompatibility complex class II showed truncated IgM and blunted IgG responses and uniformly high lethality. JEV infection resulted in extensive CD8+T cell activation, judged by upregulation of surface markers CD69 and CD25 and cytokine production after stimulation with a JEV NS4B protein-derived H-2Db-binding peptide and trafficking of virus-immune CD8+T cells into the CNS. However, no significant effect of CD8+T cells on the survival phenotype was found, which was corroborated in knockout mice lacking key effector molecules (Fas receptor, perforin, or granzymes) of cytolytic pathways triggered by T lymphocytes. Accordingly, CD8+T cells are mostly dispensable for recovery from infection with JEV. This finding highlights the conflicting role that CD8+T cells play in the pathogenesis of JEV and closely related encephalitic flaviviruses such as West Nile virus.
Social media menace?
Authors: Fawcett Anne , Baguley John
Published: April 2011

A vet in general practice performs an enterotomy on a bulldog to remove a foreign body. The dog is presented to an emergency centre 24 hours later for wound dehiscence secondary to self trauma, which is treated successfully at cost to the client. A vet student completing extramural studies at the centre posts a photo of himself with the dog in recovery from anaesthesia on his Facebook page, with a caption, ‘Me with a dog recovering from a botched operation.’ The client, who is a Facebook ‘friend’ of the student, recognises her dog in the photo and demands a refund for the initial surgery because it was ‘botched’. Should the original vet provide a refund and what should happen to the student?
Diagnosis and treatment of equine pleuropneumonia
Authors: Copas Victoria
Published: April 2011

Pleuropneumonia has been reported in horses since the early 20th century. The predominant risk factor is transportation, which compromises lower respiratory tract defences. Hence, competition horses and racing thoroughbreds are predisposed to the condition. The highest survival rates for equine pleuropneumonia are achieved following prompt recognition and rapid initiation of treatment. With appropriate medical and surgical therapy, the prognosis for horses with pleuropneumonia is favourable, with reported survival rates ranging from between 43 and 76 per cent. Many thoroughbreds that recover return to racing, and a large proportion go on to win at least one race. This article describes the diagnosis and treatment of equine pleuropneumonia, and highlights how to deal with some specific complications that might arise in rare cases.
Management of husbandry‐related problems in guinea pigs
Authors: Fawcett Anne
Published: April 2011

Poor husbandry is a leading cause of morbidity and mortality in guinea pigs. Subtle signs of illness in guinea pigs are also easily overlooked by owners, which means that many guinea pigs are often presented to the veterinary surgeon in a critical condition. By this stage, treatment, no matter how aggressive, may be unrewarding. This article discusses the common conditions affecting pet guinea pigs and the role of husbandry and diet in the aetiology and prevention of these diseases. In addition, it highlights the importance of educating clients to ensure they seek veterinary attention as soon as possible if their guinea pigs display signs of illness.
Missing opportunities for preventing unwanted pregnancy: a qualitative study of emergency contraception
Authors: Maharaj Pranitha , Rogan Michael
Published: March 2011

Background and methodology

High levels of unplanned pregnancy among young people are a huge public health problem in South Africa. However, use of emergency contraception (EC) remains low. Studies suggest that providers constitute an important link to increasing access to EC use. The aim of the study was to provide greater insights into the attitudes of providers towards EC in order to better understand factors influencing uptake. The study drew upon 30 in-depth interviews with providers at private and public health facilities in Durban, South Africa.

Results

The results of the study highlight several barriers to the provision of EC in both public and private health facilities. The cost of EC products in commercial pharmacies is likely to be a major barrier to use for many women. In addition, providers in both public and private facilities are often reluctant to provide EC over the counter because they feel that the use of EC is likely to discourage regular use of contraception and increase the risk of unprotected sexual intercourse and, as a result, contribute to the spread of HIV/AIDS in South Africa. In addition, they reported that they do not have an opportunity to counsel women about EC because of time constraints. Providers in both the public and private sectors also demonstrated a level of uncertainty about the clinical effects of EC pills and on the regulations surrounding their provision.

Discussion and conclusions

Despite relatively progressive legislation on EC provision and the widespread availability of EC products in South Africa, providers in pharmacies, family planning clinics and public health clinics need more training on EC provision. Interventions should aim to educate health providers on both the clinical and social aspects of EC provision.
Teenage pregnancies that end in abortion: what can they tell us about contraceptive risk-taking?
Authors: Hoggart Lesley , Phillips Joan
Published: March 2011

Background and methodology

In 1999, the Government set the ambitious target of halving the number of under-18 conceptions by 2010. It is now clear that this target will not be met. Much media and policy attention has been paid to teenage mothers, and yet approximately 50% of teenage conceptions end in abortion not motherhood. In London, where the present research was based, the percentage is significantly higher. The research into teenage abortion and repeat abortion, though based in London, generated insights that could potentially help different areas reduce the number of under-18 conceptions ending in abortion. A qualitative research methodology was adopted and a wide range of interviews were conducted with young women, and professionals, in 10 London primary care trusts.

Results

Our analysis adds to a substantial body of qualitative research that points to the complexity of sexual decision-making for young women. Contraceptive risk-taking was evident as some young women spoke of the difficulties they experienced with user-dependent methods (primarily the condom and the pill) in often unplanned, sexual encounters. They were also generally poorly informed about different contraceptive methods. Misunderstandings about fertility also emerged as an important issue that can lead young women to draw the wrong conclusions if they do not become pregnant following unprotected sex.

Conclusions

Young people need improved access to, and informed understanding of, the full range of contraceptive methods available to them. In addition, efforts should be made to enable young women to have a better understanding of their own likely fertility.
Intentions in critical clinical settings: a study of medical students' perceptions
Authors: Juth Niklas , Tillberg Therése , Lynöe Niels
Published: March 2011

The aim of this pilot study was to develop a realistic clinical case for identifying Knobe's asymmetric effect, ie, the tendency to ascribe intentions to a larger extent when an act is considered wrong, as well as to compare medical students at the beginning and end of their curriculum. A vignette about a critically ill 72-year-old patient in need of an operation was used, with two different outcomes: the patient dies or the patient recovers. Approximately half of the students received the ‘recovery case’ and half the ‘death case’. The questions asked were whether it was right to perform the risky operation and whether the head of the clinic brought about the patient's death/recovery intentionally. Among students in their first term an asymmetry in response pattern was identified. This asymmetry was not found among students in their final term. The difference between term 1 and term 11 students is believed to be due to the socialisation of medical students towards clinical reasoning regarding the moral role of intentions. Although no Knobe effect could be detected among term 11 students, a related adaptation effect was detected, indicating that students at the end of their medical school also tend to adapt their ascription of intentions to their moral evaluation of the act. By using clinically relevant cases a new effect has thus been identified that might be useful when investigating experienced clinicians and their views on intentions. The cases and effect merit further investigation.
Vertebral artery stenting in a patient with reversed flow in the anterior spinal artery
Authors: Dubow Jordan , Riina Howard , Patsalides Athos
Published: April 2011

We present neuroimages for a patient in a locked-in state with reversed flow in the anterior spinal artery as a result of bilateral distal vertebral artery occlusion. Following vertebral artery stenting, there is markedly improved flow in the posterior circulation and significant neurological recovery.
Prevalence of mixed trematode infections in an abattoir receiving cattle from northern Portugal and north‐west Spain
Authors: Arias M. , Lomba C. , Dacal V. , Vázquez L. , Pedreira J. , Francisco I. , Piñeiro P. , Cazapal‐Monteiro C. , Suárez J. L. , Díez‐Baños P. , Morrondo P. , Sánchez‐Andrade R. , Paz‐Silva A.
Published: April 2011

Between February 2007 and January 2009, a total of 776 slaughtered animals were examined for the presence of Trematoda in the liver, gall bladder, oesophagus and stomach (rumen and reticulum). Data collected were analysed by the age and breed of the animals. The percentage of cattle from which Trematoda were found was 38 per cent (95 per cent confidence interval [CI] 35 to 41 per cent); 28 per cent (95 per cent CI 25 to 31 per cent) had Fasciola hepatica, 12 per cent (95 per cent CI 10 to 14 per cent) Calicophoron daubneyi and 6 per cent (95 per cent CI 4 to 8 per cent) Dicrocoelium species. A significantly high prevalence of fasciolosis and dicrocoeliosis was observed in cattle over 10 years of age. Autochthonous Rubia Gallega cattle had the highest prevalence of fasciolosis and crossbred cattle had the highest prevalence of dicrocoeliosis (P<0.05). Twenty per cent (95 per cent CI 15 to 25 per cent) of the cattle positive for Fasciola also had Calicophoron species; 10 per cent (95 per cent CI 6 to 14 per cent) also had small liver flukes (Dicrocoelium species).
PERSONAL HISTORY OF MY ENGAGEMENT WITH CUPRATE SUPERCONDUCTIVITY, 1986–2010
Authors: ANDERSON PHILIP W.
Published: April 2011

Six months ago, I was asked to write a personal history of my engagement with the high-Tc problem of the cuprate superconductors, in a rather informal and autobiographical style. As the work proceeded, I realized that it was impossible and would have been dishonest to separate out my rather amusing but seminal early fumblings from the complete restructuring of the problem which I have achieved during the past decade. But the result became considerably too long, by over half, for its intended recipient. The assignment had left me with no obligation to deal with all the fascinating but irrelevant phenomenology which I had more or less instinctively ignored on my way, but that feature also fails to endear the article to any conceivable editorial board containing knowledgeable experts on the subject. Also, their purpose was for it to serve as an "introduction to the more technical debates", but its message is that almost all of these are not relevant. They are not, on the whole, focused on achieving understanding of the crucial experimental anomalies, many, if not most, of which are now understood. The key to the problem is a new method of dealing with the constrained Hilbert space which follows from the necessity of Gutzwiller projection.
THE METHOD OF MULTISCALE ASYMPTOTIC EXPANSIONS FOR THE PROBLEM OF HEAT EXCHANGE IN COMPOSITE PLANE WALL WITH STATIONARY RANDOM FIELDS
Authors: HE WEN-MING , GUAN XIAO-FEI , ZHANG XIN-JUN
Published: April 2011

In this paper, we discuss the problem of heat exchange in a composite plane wall whose heat transmitting coefficient is a stationary random field. We present a method of multiscale asymptotic expansions and the corresponding finite element method to solve the problem.
GIANT MAGNETO-IMPEDANCE EFFECTS AND MAGNETIC PERMEABILITY IN CuBe/INSULATOR/CoNiP ELECTROLESS DEPOSITED COMPOSITE WIRES
Authors: CHENG J. K. , ZHAO Z. J. , XIN H. L. , WU Z. M. , YANG X. L. , YUAN W. Z.
Published: April 2011

Giant magneto-impedance (GMI) effects were investigated in CuBe / CoNiP and CuBe /Insulator/ CoNiP composite wires prepared by electroless deposition on pure or insulated CuBe wires. Experimental results show that the maximal GMI ratio and the field sensitivity of the composite wires are further improved by adding an insulator layer between the CuBe core and ferromagnetic layer. A distinct MI effect was observed in the composite wires with insulator even at low frequencies. MI ratio is about 18% at 20 kHz and 239% at 600 kHz. The maximal field sensitivity is 34%/Oe at 600 kHz. The properties of GMI in these composite wires are analyzed via complex permeability.
MOLECULAR DYNAMICS SIMULATION OF UO2: AN ALTERNATIVE RIGID ION MODEL POTENTIAL
Authors: GÜNAY S. D. , AKDERE Ü. , KAVANOZ H. B. , TAŞSEVEN Ç.
Published: April 2011

A semi-empirical effective interionic potential model has been parameterized to investigate UO 2 by molecular dynamics simulation technique. The simulations were performed in the constant pressure–temperature ensemble between 300 K–3200 K at 100 K intervals. The pair distribution functions and coordination numbers signal the onset of structural changes at temperatures in accord with the Bredig transition and melting. The oxygen ion diffusion coefficients calculated from the mean square displacements markedly increase the liquid like value at T > 2100 K . The transition to the superionic state and melting are well reproduced within the limitations of a rigid ion potential.
THEORETICAL PREDICTION OF DEBYE TEMPERATURE FOR MANTLE MINERALS AT HIGH TEMPERATURES
Authors: PANDEY ANJANI K. , SRIVASTAVA ABHAY P.
Published: April 2011

The seismic properties of a material depend on composition, crystal structure, temperature, pressure and in some cases defect concentrations. Most of the earth is made up of crystals. The elastic properties of crystals depend on orientation and frequency. Thus, the interpretation of seismic data or the extrapolation of laboratory data requires knowledge of crystal or mineral physics, elasticity and thermodynamics. In the present work, we calculated the shear modulus, seismic velocities and Debye temperatures at different high temperature ranges. The temperature dependence of elastic properties such as shear modulus, seismic velocities and Debye temperatures has been measured using Hill's averaging method and other thermodynamic methods for five silicate mantle minerals viz. MgAl2O4, Mg2SiO4, Fe2SiO4, Mn2SiO4, and Co2SiO4. The results are found to be in good agreement with experimental values.
DETERMINISTIC COLLECTIVE DIRECTIONAL TRANSPORT IN ONE-DIMENSIONAL FLASHING RATCHET POTENTIALS
Authors: CHEN HONGBIN , ZHENG ZHIGANG
Published: March 2011

In the absence of thermal fluctuations and other external forces, a single particle will be pinned at the bottom of a flashing ratchet potential under the overdamped condition. Unidirectional motion becomes possible if there exist interactions among particles. In this paper, the overdamped directed motion of a dimer with two heads in a flashing ratchet potential is investigated. We propose the mechanism to reveal how two heads of the dimer cooperate and help each other to move processively. The necessary condition of directed motion is analytically given, which is in good agreement with numerical simulation results. Furthermore, the resonant steps of the current are observed and discussed. The scenario and the results proposed in this paper may shed light on the elaborations of artificial molecular motors.