bluuebunny/crossref_metadata_2025 huggingface dataset:
An integrative approach to detect subtle trophic niche differentiation in the sympatric trawling bat species Myotis dasycneme and Myotis daubentonii
Authors: Krüger F. , Clare E. L. , Greif S. , Siemers B. M. , Symondson W. O. C. , Sommer R. S.
Published: September 2013

Bats are well known for species richness and ecological diversity, and thus, they provide a good opportunity to study relationships and interaction between species. To assess interactions, we consider distinct traits that are probably to be triggered by niche shape and evolutionary processes. We present data on the trophic niche differentiation between two sympatric European trawling bat species, Myotis dasycneme and Myotis daubentonii, incorporating a wide spectrum of methodological approaches. We measure morphological traits involved in foraging and prey handling performance including bite force, weightlifting capacity and wing morphology. We then measure resulting prey consumption using both morphological and molecular diet analyses. These species closely resemble each other in morphological traits, however, subtle but significant differences were apparent in bite force and lift capacity, which are related to differences in basic body and head size. Both morphological and molecular diet analyses show strong niche overlap. We detected subtle differences in less frequent prey items, as well as differences in the exploitation of terrestrial and aquatic‐based prey groups. Myotis dasycneme feeds more on aquatic prey, like Chironomidae and their pupal stages, or on the aquatic moth Acentria ephemerella. Myotis daubentonii feeds more on terrestrial prey, like Brachycera, or Coleoptera. This suggests that these bats use different microhabitats within the habitat where they co‐occur.
Multilocus analyses reveal little evidence for lineage‐wide adaptive evolution within major clades of soft pines (Pinus subgenus Strobus)
Authors: Eckert Andrew J. , Bower Andrew D. , Jermstad Kathleen D. , Wegrzyn Jill L. , Knaus Brian J. , Syring John V. , Neale David B.
Published: September 2013

Estimates from molecular data for the fraction of new nonsynonymous mutations that are adaptive vary strongly across plant species. Much of this variation is due to differences in life history strategies as they influence the effective population size (Ne). Ample variation for these estimates, however, remains even when comparisons are made across species with similar values of Ne. An open question thus remains as to why the large disparity for estimates of adaptive evolution exists among plant species. Here, we have estimated the distribution of deleterious fitness effects (DFE) and the fraction of adaptive nonsynonymous substitutions (α) for 11 species of soft pines (subgenus Strobus) using DNA sequence data from 167 orthologous nuclear gene fragments. Most newly arising nonsynonymous mutations were inferred to be so strongly deleterious that they would rarely become fixed. Little evidence for long‐term adaptive evolution was detected, as all 11 estimates for α were not significantly different from zero. Nucleotide diversity at synonymous sites, moreover, was strongly correlated with attributes of the DFE across species, thus illustrating a strong consistency with the expectations from the Nearly Neutral Theory of molecular evolution. Application of these patterns to genome‐wide expectations for these species, however, was difficult as the loci chosen for the analysis were a biased set of conserved loci, which greatly influenced the estimates of the DFE and α. This implies that genome‐wide parameter estimates will need truly genome‐wide data, so that many of the existing patterns documented previously for forest trees (e.g. little evidence for signature of selection) may need revision.
Autecological traits determined two evolutionary strategies in Mediterranean plants during the Quaternary: low differentiation and range expansion versus geographical speciation in Linaria
Authors: Blanco‐Pastor J. L. , Vargas P.
Published: September 2013

The evolutionary patterns of the Mediterranean flora during the Quaternary have been relatively well documented based on phylogenetic and biogeographic analyses, but few studies have addressed the evolutionary traits that determined diversification and range expansion success during this period. We analysed previously published and newly generated sequences of three plastid noncoding regions (rpl32‐trnLUAG, trnS‐trnG and trnL‐trnF), the nuclear ribosomal internal transcribed spacer (ITS) and a low‐copy nuclear gene intron (AGT1) of Linaria sect. Supinae, a group of angiosperms that diversified in the Quaternary. The origin and recent colonization dynamics of closely related lineages were inferred by biogeographic reconstruction and phylogeographic analyses, while breeding system experiments coupled with ecological and morphological data were used to test association with range expansion and diversification. A combination of traits, including selfing, short lifespan and the ability to tolerate a wide variety of substrates, were key factors underlying range expansion after long‐distance dispersal throughout the Mediterranean basin. By contrast, self‐incompatibility may have promoted higher diversification rates in narrow ranges of the Iberian Peninsula. We argue that a few traits contributed to the adoption of two contrasting strategies that may have been predominant in the evolution of Mediterranean angiosperms.
Computational fluid dynamics analysis of salivary flow and its effect on sialolithogenesis
Authors: Zhu P , Lin Y , Lin H , Xu Y , Zheng QY , Han Y
Published: September 2013

Objective

Sialolithiasis is a common disease caused by intraductal stones, formed by reduction in salivary flow, salivary stagnation, and metabolic events. We used computational fluid dynamics to investigate changes in salivary flow field around parotid stones of different shapes.

Materials and Methods

Three‐dimensional configurations of the Stensen's duct were reconstructed from computed tomography sialographic images. Fluid dynamics modeling was used to analyze the salivary flow field around stones under unstimulated and stimulated conditions.

Results

The majority of sialoliths were oval‐shaped (59/98), followed by irregular (24/98) and round (15/98). Salivary velocity was significantly higher around streamlined stones, compared with round (P = 0.013) and oval (P = 0.025) types. Changes in salivary flow field around sialoliths were found to affect the pattern of mineral deposition in saliva. The area of low velocity around the round stone was double the size observed around the streamlined stone during the unstimulated state, whereas in the stimulated state, local vortexes were formed on the downstream side of round and oval stones.

Conclusions

Salivary flow field around sialoliths plays an important role in the progression of multicentric stones, and analysis of the salivary dynamics during sialolithiasis may provide deeper understandings of the condition and aid in developing successful treatment strategies.
Postoperative Pain after Major Abdominal Surgery: Is It Gender Related? An Observational Prospective Study
Authors: Theodoraki Kassiani , Staikou Chryssoula , Fassoulaki Argyro
Published: September 2013

Objectives

Gender may be associated with postoperative pain. This study aimed to assess pain intensity and postoperative analgesic requirements in female and male patients scheduled for major abdominal surgery.

Methods

Sixty‐five patients, 31 men and 34 women, scheduled for major abdominal surgery were recruited. Anesthesia and intraoperative analgesics were standardized in all patients. Postoperatively, all patients had access to a 60 mL PCA pump containing 1 mg/mL morphine and 50 μg/mL droperidol. Morphine consumption and VAS scores at rest and after cough were recorded 2, 4, 8, 24, and 48 hours postoperatively.

Results

Of the 65 patients recruited for the study, 30 women and 30 men aged 65 ± 8.9 and 66 ± 9.0 years, respectively, were included in the analysis. Morphine consumption was examined 2, 4, 8, 24, and 48 hours after surgery and did not differ in women vs. men (mean ± standard deviation, 4.4 ± 3.2 vs. 5 ± 4.8, 7.2 ± 4.8 vs. 8.7 ± 6.9, 10.4 ± 7.1, vs. 12.5 ± 8.5, 22.9 ± 11.6 vs. 25.6 ± 14.5, and 36.2 ± 15.7 vs. 39.7 ± 21.7 mg, P = 0.384). Cumulative morphine consumption was not significantly different in women vs. men when normalized for body mass index (mean ± standard deviation, 0.17 ± 0.13, 0.28 ± 0.20, 0.40 ± 0.30, 0.88 ± 0.46, and 1.38 ± 0.59 mg/kg/m2 in women and 0.18 ± 0.18, 0.31 ± 0.25, 0.46 ± 0.32, 0.95 ± 0.54, and 1.47 ± 0.81 mg/kg/m2 in men at 2, 4, 8, 24, and 48 hours postoperatively (P = 0.567). Both genders exhibited similar VAS pain scores (mm) at rest and after cough (P = 0.476, P = 0.378, respectively).

Conclusions

Postoperative morphine requirements did not differ between female and male patients undergoing major abdominal surgery. Pain intensity reported at rest and after cough did not differ between the 2 groups.
Altered relationship between R‐R interval and R‐R interval variability in endurance athletes with overtraining syndrome
Authors: Kiviniemi A. M. , Tulppo M. P. , Hautala A. J. , Vanninen E. , Uusitalo A. L. T.
Published: September 2013

Autonomic dysfunction decreases within‐subject correlation between R‐R interval length (RRi) and vagally mediated RRi variability in cardiac disease. We tested the hypothesis that overtraining syndrome (OTS) may also weaken this relationship. Nine OTS and 10 control endurance athletes underwent 24‐h electrocardiogram monitoring, which was repeated in eight OTS and nine control athletes after 6 months, when two OTS athletes still had symptoms of OTS. The power of high‐frequency (HF) oscillations of RRi was analyzed in 5‐min epochs over the whole recording. Quadratic regression was performed between 5‐min values of RRi and log‐transformed (ln) HF to obtain R2 for each recording. The relationship between RRi and HFln was higher in the OTS athletes than controls [R2: 0.87 (90% confidence interval, CI: 0.84–0.89) vs 0.78 (90% CI: 0.72–0.84); P = 0.034; effect size = 1.22]. Large decrease in R2 was observed in six recovered OTS athletes after 6 months follow‐up [ΔR2: −0.12 (90% CI: −0.25–0.01); P = 0.11; effect size = 1.44] with no changes in the controls. Mean values of RRi and its variability did not differ between the groups. The within‐subject correlation between RRi and vagally mediated RRi variability was stronger in endurance athletes with OTS compared with controls. The present findings may improve the detection of OTS and recovery from OTS in endurance athletes.
Temporal Accuracy in Urban Growth Forecasting: A Study Using the SLEUTH Model
Authors: Chaudhuri Gargi , Clarke Keith C.
Published: September 2013

This study attempts to establish multi‐temporal accuracy of the predicted maps produced by a land use change simulation model over time. Validation of the forecasted results is an essential part of predictive modeling and it becomes even more important when the models are used for decision making purposes. The present study uses a popular land use change model called SLEUTH to investigate the temporal trend of accuracy of the predicted maps. The study first investigates the trend of accuracy of the predicted maps from the immediate future to the distant future. Secondly, it investigates the impact of the prediction date range on the accuracy of the predicted maps. The objectives are tested for the city of Gorizia (Italy) using three sets of map comparison techniques, Kappa coefficients, Kappa Simulation and quantity disagreement and allocation disagreement. Results show that, in addition to the model's performance, the decrease in the accuracy of the predicted maps is dependent on factors such as urban history, uncertainty of input data and accuracy of reference maps.
Geocoding Large Population‐level Administrative Datasets at Highly Resolved Spatial Scales
Authors: Edwards Sharon E. , Strauss Benjamin , Miranda Marie Lynn
Published: September 2013

Using geographic information systems to link administrative databases with demographic, social, and environmental data allows researchers to use spatial approaches to explore relationships between exposures and health. Traditionally, spatial analysis in public health has focused on the county, ZIP code, or tract level because of limitations to geocoding at highly resolved scales. Using 2005 birth and death data from North Carolina, we examine our ability to geocode population‐level datasets at three spatial resolutions – zip code, street, and parcel. We achieve high geocoding rates at all three resolutions, with statewide street geocoding rates of 88.0% for births and 93.2% for deaths. We observe differences in geocoding rates across demographics and health outcomes, with lower geocoding rates in disadvantaged populations and the most dramatic differences occurring across the urban‐rural spectrum. Our results suggest that highly resolved spatial data architectures for population‐level datasets are viable through geocoding individual street addresses. We recommend routinely geocoding administrative datasets to the highest spatial resolution feasible, allowing public health researchers to choose the spatial resolution used in analysis based on an understanding of the spatial dimensions of the health outcomes and exposures being investigated. Such research, however, must acknowledge how disparate geocoding success across subpopulations may affect findings.
Neuropharmacological lesion localization in idiopathic Horner's syndrome in Golden Retrievers and dogs of other breeds
Authors: Simpson Katherine M. , Williams David L. , Cherubini Giunio B.
Published: September 2013

Objective

To investigate whether idiopathic Horner's syndrome (HS) in Golden Retrievers is an exclusively preganglionic disorder based on denervation hypersensitivity pharmacological testing with phenylephrine.

Animals Studied

Medical records of dogs presented with HS between 2000 and 2012. Dogs presented with additional ocular or systemic signs were excluded.

Procedures

Clinical data examined included age, sex, duration of clinical signs, ancillary diagnostic test results, and time to mydriasis on topical ocular application of 1% phenylephrine. Lesions were diagnosed as postganglionic (mydriasis within 20 min) or preganglionic (mydriasis between 20 and 45 min).

Results

Medical records of 21 dogs of nine different breeds were included. An etiopathogenesis for Horner's syndrome was determined in five dogs, none of which were Golden Retrievers. All diagnoses correlated with pharmacological lesion localization. Ten Golden Retrievers were included (eight male and two female) with a mean age of 8.5 years (range: 4–13). Lesion localization was diagnosed as postganglionic in eight (mean: 10 min [range: 6–18]) and preganglionic in two Golden Retrievers (20 and 24 min). All cases were unilateral and had completely resolved within 15 weeks (range: 11–20). Recurrence was not reported in any of the patients.

Conclusions

Idiopathic postganglionic HS was diagnosed in eight of 10 Golden Retrievers contradicting previous reports of a purely preganglionic localization. Etiopathogenesis of canine idiopathic HS remains to be determined; nevertheless, a vascular etiology cannot be excluded. Future studies using magnetic resonance angiography may aid in clarifying the pathogenesis.
Optimization of Geophone Array for Monitoring Geologic Carbon Sequestration Using Double-Difference Tomography
Authors: Fahrman Ben , Westman Erik , Karfakis Mario , Luxbacher Kray
Published: September 2013

Synthetic data were analyzed to determine the most cost-effective tomographic monitoring system for a geologic carbon sequestration injection site. Double-difference tomographic inversion was performed on 125 synthetic data sets: five stages of CO2 plume growth, five seismic event regions, and five geophone arrays. Each resulting velocity model was compared quantitatively to its respective synthetic velocity model to determine accuracy. The results were examined to determine a relationship between cost and accuracy in monitoring, verification, and accounting applications using double-difference-tomography. The geophone arrays with widely varying geophone locations, both laterally and vertically, performed best.
Experimental Study of Methane Fuel Oxycombustion in a Spark-Ignited Engine
Authors: Van Blarigan Andrew , Kozarac Darko , Seiser Reinhard , Cattolica Robert , Chen Jyh-Yuan , Dibble Robert
Published: September 2013

An experimental investigation of methane fuel oxycombustion in a variable compression ratio, spark-ignited piston engine has been carried out. Compression ratio, spark-timing, and oxygen concentration sweeps were performed to determine peak performance conditions for operation with both wet and dry exhaust gas recirculation (EGR). Results illustrate that when operating under oxycombustion conditions an optimum oxygen concentration exists at which fuel-conversion efficiency is maximized. Maximum conversion efficiency was achieved with approximately 29% oxygen by volume in the intake for wet EGR, and approximately 32.5% oxygen by volume in the intake for dry EGR. All test conditions, including air, were able to operate at the engine's maximum compression ratio of 17 to 1 without significant knock limitations. Peak fuel-conversion efficiency under oxycombustion conditions was significantly reduced relative to methane-in-air operation, with wet EGR achieving 23.6%, dry EGR achieving 24.2% and methane-in-air achieving 31.4%. The reduced fuel-conversion efficiency of oxycombustion conditions relative to air was primarily due to the reduced ratio of specific heats of the EGR working fluids relative to nitrogen (air) working fluid.
Modal Representation of Second Order Flexible Structures With Damped Boundaries
Authors: Sirota Lea , Halevi Yoram
Published: September 2013

The problem of obtaining a modal (i.e., infinite series) solution of second order flexible structures with viscous damping boundary conditions is considered. In conservative boundary systems, separation of variables is well established and there exist closed form modal solutions. However, no counterpart results exist for the damped boundary case and previous publications fall short of providing a complete solution for the series, in particular, its coefficients. The paper presents the free response of damped boundary structures to general initial conditions in the form of an infinite sum of products of spatial and time functions. The problem is attended via Laplace domain approach, and explicit expressions for the series components and coefficients are derived. The modal approach is useful in finite dimension modeling, since it provides a convenient framework for truncation. It is shown via examples that often few modes suffice for approximation with good accuracy.
An Efficient Branch-and-Bound Algorithm for Interface-Based Modular Product Design and Performance Evaluation
Authors: Jung-Woon Yoo John , Aryasomayajula Anirudh , Ki Moon Seung
Published: September 2013

In our earlier work, we have proposed a cyberinfrastructure-based collaboration system for modular product design. One of the main components of the system is a design repository to which suppliers can upload the descriptions of their components using machine-readable, interface-based component description language, so that manufacturers can refer to the descriptions during product design phases. In this paper, we propose an efficient algorithmic approach based on a branch-and-bound (BnB) algorithm to support product design using the interface-based component descriptions stored in the design repository. This product design problem is categorized into a planning problem, whose complexity is known as non-deterministic polynomial-time (NP) hard. For performance evaluation, we compare the performance of the branch-and-bound algorithm with that of a depth-first search (DFS) algorithm, which is an exhaustive search method. This paper describes the details of the proposed branch-and-bound algorithm using a case study and experimental results are discussed.
Development of an Integrated Approach to the Design of Reconfigurable Micro/Mesoscale CNC Machine Tools
Authors: Pérez Roberto , Molina Arturo , Ramírez-Cadena Miguel
Published: September 2013

In the present, the technology related to the micro/meso manufacturing is promising as a key enabling technology for maximizing high value manufacturing. This paper addresses a new methodology to design reconfigurable micro/mesoscale CNC machine tools in the integrated product, process, and manufacturing system development context. This is followed by a description of the design of a reconfigurable two-axis first-generation test bed CNC micromachine tool that was developed to assess the feasibility of the new design method. The test bed utilizes a high-speed miniature spindle that is required to obtain appropriate cutting velocities for the efficient cutting of metals, use micro-actuators for the axis movements and open-architecture controllers, in order to guarantee the reconfigurability properties of the micromachine. Results indicate the new methodology enhances the design of reconfigurable micro/mesoscale CNC machine tools in the integrated product, process, and manufacturing system development context, following the prescriptive models of design.
Multicriteria Decision Analysis for Wave Power Technology in Canada
Authors: Monds Joshua R.
Published: September 2013

Three individual wave power generation technologies were studied and evaluated using multicriteria decision analysis through the use of the PROMETHEE method. To evaluate the three technologies, data were collected from previously performed experimental testing on the performance of each wave power generation technology. These data were used to feed into seven different criteria; namely the capacity factor, rated power, capital cost, operation and maintenance (O&M) costs, cost of electricity (COE) for a 10 year payback, maturity, and survivability. The associated data and criteria were used to determine the optimal technology. The results from the Decision Lab modeling ranked the Wave Dragon, AquaBuOY, and Pelamis technologies as 1, 2, and 3, respectively, for all three locations: Tofino/Ucluelet, Hibernia Oil Platform, and St. John's, Newfoundland. A sensitivity analysis of the threshold values determined for the baseline modeling indicated that the original ranking was essentially unaffected when the threshold values were modified (increased and decreased). The weights of the criterion were individually adjusted to evaluate any change in ranking order. A sizable increase in weighting of greater than 40% of any one criterion (while the others were weighed equally) resulted in a change of the overall ranking order of the three technologies. Final weightings on each of the criterion were assigned with preference on rated power, COE, and maturity stage. All other criteria were weighted equally and like the baseline modeling output, the results of the model ranked Wave Dragon, AquaBuOY, and Pelamis from most favorable to least favorable for all three of the locations analyzed.
Evaluation of Reissner’s Equations of Finite Pure Bending of Curved Elastic Tubes
Authors: Levyakov S.V.
Published: September 2013

The paper discusses nonlinear equations of in-plane bending of curved tubes formulated by E. Reissner in terms of two unknown functions and two unknown parameters. To solve the equations, a numerical method based on the finite-difference approximations and Newton–Raphson iteration technique is proposed. Deformations and stresses in tubes of circular and noncircular cross sections are studied for a wide range of geometrical parameters. The accuracy of the equations is evaluated by comparing the numerical results with predictions obtained by a special shell finite element.
Potassium hydroxide polishing of nanoscale deep reactive-ion etched ultrahigh aspect ratio gratings
Authors: Bruccoleri Alexander , Guan Dong , Mukherjee Pran , Heilmann Ralf K. , Schattenburg Mark L. , Vargo Stephen
Published: September 2013

A fabrication process has been developed to chemically polish the sidewalls of 200 nm-pitch gratings via potassium hydroxide (KOH) etching following the Bosch deep reactive-ion etching (DRIE) process. Previous KOH polishing experiments focused on micron scale features. This work is the first reported combined DRIE-KOH etching process on the nanoscale for ultrahigh aspect ratio structures with feature sizes 30 times smaller than previously published work. The primary application of the gratings is x-ray spectroscopy and requires polished sidewalls for efficient x-ray reflection. Polishing is also critical for increasing the open area by narrowing the grating bars, which increases the throughput of x-rays. The increased open area is also valuable for other applications such as ultraviolet filtration, neutron spectroscopy and biofiltration. Advanced Bosch processes leave approximately 4 nm, root mean square (RMS), of roughness on the sidewalls. This roughness needs to be reduced to below 1 nm to efficiently reflect soft x-rays with wavelengths between 1 and 5 nm. Furthermore, high aspect ratio DRIE can result in bar width variations of approximately a factor of two from the top to the middle of the channel, commonly referred to as bowing. The polishing procedure presented here removes the roughness to below the resolution of the scanning electron microscope, and was measured via an atomic force microscope to be less than 1 nm RMS. The bowing has also been reduced by at least a factor of 3. The polishing process takes advantage of the anisotropy of KOH silicon etching. Specifically, the {111} silicon planes etch approximately 100 times slower than other crystal planes. This anisotropy allows the grating bars to be etched in 50% by weight KOH at room temperature for up to 60 min. Long etches have several key requirements, including 0.2 degree alignment of the grating with respect to the {111} planes, mask roughness below 40 nm and minimal defects in the silicon. If these requirements are not met, the grating will quickly be destroyed by the etch, which etches the non-{111} planes in excess of 1 μm per hour. The fabrication steps of this work are described in detail including a novel technique to align the 200 nm-pitch interference lithography image grating to the {111} planes of a ⟨110⟩ silicon wafer.
Integration of microwave tomography with magnetic resonance for improved breast imaging
Authors: Meaney Paul M. , Golnabi Amir H. , Epstein Neil R. , Geimer Shireen D. , Fanning Margaret W. , Weaver John B. , Paulsen Keith D.
Published: September 2013

Purpose:

Breast magnetic resonance imaging is highly sensitive but not very specific for the detection of breast cancer. Opportunities exist to supplement the image acquisition with a more specific modality provided the technical challenges of meeting space limitations inside the bore, restricted breast access, and electromagnetic compatibility requirements can be overcome. Magnetic resonance (MR) and microwave tomography (MT) are complementary and synergistic because the high resolution of MR is used to encode spatial priors on breast geometry and internal parenchymal features that have distinct electrical properties (i.e., fat vs fibroglandular tissue) for microwave tomography.

Methods:

The authors have overcome integration challenges associated with combining MT with MR to produce a new coregistered, multimodality breast imaging platform—magnetic resonance microwave tomography, including: substantial illumination tank size reduction specific to the confined MR bore diameter, minimization of metal content and composition, reduction of metal artifacts in the MR images, and suppression of unwanted MT multipath signals.

Results:

MR SNR exceeding 40 dB can be obtained. Proper filtering of MR signals reduces MT data degradation allowing MT SNR of 20 dB to be obtained, which is sufficient for image reconstruction. When MR spatial priors are incorporated into the recovery of MT property estimates, the errors between the recovered versus actual dielectric properties approach 5%.

Conclusions:

The phantom and human subject exams presented here are the first demonstration of combining MT with MR to improve the accuracy of the reconstructed MT images.
Vision 20/20: Single photon counting x‐ray detectors in medical imaging
Authors: Taguchi Katsuyuki , Iwanczyk Jan S.
Published: September 2013

Photon counting detectors (PCDs) with energy discrimination capabilities have been developed for medical x‐ray computed tomography (CT) and x‐ray (XR) imaging. Using detection mechanisms that are completely different from the current energy integrating detectors and measuring the material information of the object to be imaged, these PCDs have the potential not only to improve the current CT and XR images, such as dose reduction, but also to open revolutionary novel applications such as molecular CT and XR imaging. The performance of PCDs is not flawless, however, and it seems extremely challenging to develop PCDs with close to ideal characteristics. In this paper, the authors offer our vision for the future of PCD‐CT and PCD‐XR with the review of the current status and the prediction of (1) detector technologies, (2) imaging technologies, (3) system technologies, and (4) potential clinical benefits with PCDs.
Investigating the feasibility of photon‐counting K‐edge imaging at high x‐ray fluxes using nonlinearity corrections
Authors: Rink Kristian , Oelfke Uwe , Fiederle Michael , Zuber Marcus , Koenig Thomas
Published: September 2013

Purpose:

Pulse pileup occurring at high x‐ray fluxes can severely degrade the energy resolution provided by a photon counting detector, which can represent a problem in spectroscopic CT when performing quantitative material discrimination tasks. As the effects of pileup can be most easily seen as a degradation of a detectorˈs count rate linearity at high fluxes, it has been proposed previously to quantify and correct these nonlinearities. While this strategy has been applied successfully to materials without K‐edges, it is currently unknown if this still prevails when using medical contrast agents. The purpose of this study is to close this gap.

Methods:

A Medipix2MXR Hexa detector was employed, featuring a pixel pitch of 165µm and a 1 mm thick CdTe sensor. A phantom containing various concentrations of iodine and gadolinium contrast agents was subject to energy selective CT acquisitions, using a pulsable x‐ray source operated at 70 kVp. These acquisitions were obtained at low and high photon fluxes of 1.0 × 106 and 1.3 × 107 mm−2 s−1, respectively. Nonlinearity corrections were applied to the high‐flux projections and for each pixel separately. The results were compared to the results at low photon fluxes.

Results:

At high fluxes, a general reduction of the reconstructed attenuation coefficients was observed, which could be partially recovered using the correction strategy applied. The spectroscopic separation of iodine from the phantom material, however, degraded with increasing x‐ray flux. In contrast to this, gadolinium could still be discriminated almost as well as in the low flux case.

Conclusions:

Nonlinearity corrections applied to high flux measurements can help to recover attenuation coefficients normally obtained at low fluxes for low‐Z materials, which do not exhibit an absorption edge in the relevant energy range. However, as a result of a significant change of the x‐ray spectrum, the spectroscopic contrast normally observed for iodine was found to vanish with increasing x‐ray flux. In other words, the authorsˈ results indicate that nonlinearity corrections may be feasible only when the K‐edge of interest is sufficiently high compared to the mean photon energy, and that spectroscopic CT at high x‐ray fluxes may suffer from less limitations when using high‐Z materials as contrast agents. A future study should aim to confirm these findings under clinical conditions.
Piliation of Invasive Streptococcus pneumoniae Isolates in the Era before Pneumococcal Conjugate Vaccine Introduction in Malawi
Authors: Kulohoma Benard W. , Gray Katherine , Kamng'ona Arox , Cornick Jennifer , Bentley Stephen D. , Heyderman Robert S. , Everett Dean B.
Published: September 2013

The pneumococcal pilus has been shown to be an important determinant of adhesion and virulence in mouse models of colonization, pneumonia, and bacteremia. A pilus is capable of inducing protective immunity, supporting its inclusion in next-generation pneumococcal protein vaccine formulations. Whether this vaccine target is common among pneumococci in sub-Saharan Africa is uncertain. To define the prevalence and genetic diversity of type I and II pili among invasive pneumococci in Malawi prior to the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) into routine childhood immunization, we examined 188
Streptococcus pneumoniae
isolates collected between 2002 and 2008 (17% serotype 1). In this region of high disease burden, we found a low frequency of invasive piliated pneumococci (14%) and pilus gene sequence diversity similar to that seen previously in multiple global pneumococcal lineages. All common serotypes with pilus were covered by PCV13 and so we predict that pilus prevalence will be reduced in the Malawian pneumococcal population after PCV13 introduction.
Exercise and Sleep Deprivation Do Not Change Cytokine Expression Levels in Patients with Chronic Fatigue Syndrome
Authors: Nakamura Toru , Schwander Stephan , Donnelly Robert , Cook Dane B. , Ortega Felix , Togo Fumiharu , Yamamoto Yoshiharu , Cherniack Neil S. , Klapholz Marc , Rapoport David , Natelson Benjamin H.
Published: September 2013

A major hypothesis regarding the cause of chronic fatigue syndrome (CFS) is immune dysregulation, thought to be reflected in upregulated proinflammatory cytokines leading to the symptoms that are characteristic of this illness. Because the symptoms worsen with physical exertion or sleep loss, we hypothesized that we could use these stressors to magnify the underlying potential pathogenic abnormalities in the cytokine systems of people with CFS. We conducted repeat blood sampling for cytokine levels from healthy subjects and CFS patients during both postexercise and total sleep deprivation nights and assayed for protein levels in the blood samples, mRNA activity in peripheral blood lymphocytes (PBLs), and function in resting and stimulated PBLs. We found that these environmental manipulations did not produce clinically significant upregulation of proinflammatory cytokines. These data do not support an important role of immune dysregulation in the genesis of stress-induced worsening of CFS.
High Similarity of Novel Orthoreovirus Detected in a Child Hospitalized with Acute Gastroenteritis to Mammalian Orthoreoviruses Found in Bats in Europe
Authors: Steyer Andrej , Gutiérrez-Aguire Ion , Kolenc Marko , Koren Simon , Kutnjak Denis , Pokorn Marko , Poljšak-Prijatelj Mateja , Rački Nejc , Ravnikar Maja , Sagadin Martin , Fratnik Steyer Adela , Toplak Nataša
Published: September 2013

Mammalian orthoreoviruses (MRVs) are known to cause mild enteric and respiratory infections in humans. They are widespread and infect a broad spectrum of mammals. We report here the first case of an MRV detected in a child with acute gastroenteritis, which showed the highest similarity to an MRV reported recently in European bats. An examination of a stool sample from the child was negative for most common viral and bacterial pathogens. Reovirus particles were identified by electron microscopic examination of both the stool suspension and cell culture supernatant. The whole-genome sequence was obtained with the Ion Torrent next-generation sequencing platform. Prior to sequencing, the stool sample suspension and cell culture supernatant were pretreated with nucleases and/or the convective interaction medium (CIM) monolithic chromatographic method to purify and concentrate the target viral nucleic acid. Whole-genome sequence analysis revealed that the Slovenian SI-MRV01 isolate was most similar to an MRV found in a bat in Germany. High similarity was shared in all genome segments, with nucleotide and amino acid identities between 93.8 to 99.0% and 98.4 to 99.7%, respectively. It was shown that CIM monolithic chromatography alone is an efficient method for enriching the sample in viral particles before nucleic acid isolation and next-generation sequencing application.
Splenic Abscess Caused by Streptococcus gallolyticus subsp. pasteurianus as Presentation of a Pancreatic Cancer
Authors: Su Yanli , Miao Bin , Wang Hong , Wang Chao , Zhang Shuwen
Published: September 2013

Splenic abscesses caused by
Streptococcus bovis
are rarely reported in the literature and are mainly seen in patients with endocarditis and associated colonic neoplasia/carcinoma. We report the first case of splenic abscess caused by
Streptococcus gallolyticus
subsp.
pasteurianus
(
Streptococcus bovis
biotype II/2) as presentation of a pancreatic cancer.
Conjunctivitis Caused by Neisseria gonorrhoeae Isolates with Reduced Cephalosporin Susceptibility and Multidrug Resistance
Authors: Suzuki Takashi , Kitagawa Yutaka , Maruyama Yosuke , Yamaguchi Satoshi , Sakane Yuri , Miyamoto Hitoshi , Ohashi Yuichi
Published: September 2013

We report two cases of conjunctivitis caused by
Neisseria gonorrhoeae
with reduced cephalosporin susceptibility. Patients showed no response to cefmenoxime eye drops and intravenous ceftriaxone administration. The patients' condition improved after the addition of oral minocycline. The isolates contained the mosaic
penA
for reduction of β-lactam susceptibility.
Publisher's Expression of Concern: Geographical Differences Associated with SNPs in Nine Gene Targets among Resistant Clinical Isolates of Mycobacterium tuberculosis
Authors:   The American Society for Microbiology
Published: September 2013

The American Society for Microbiology (ASM) and the
Journal of Clinical Microbiology
(JCM) are issuing this Expression of Concern to alert readers to questions about the ownership of the data in the following publication:

IMPORTANCE
M. Hoshide, L. Qian, C. Rodrigues, R. Warren, T. Victor, H. B. Evasco II, T. Tupasi, V. Crudu, and J. T. Douglas. Geographic Differences Associated with SNPs in Nine Gene Targets among Resistant Clinical Isolates of
Mycobacterium tuberculosis
. J. Clin. Microbiol. doi:
10.1128/JCM.00857-13
.

IMPORTANCE
JCM has been notified that substantial portions of the data presented in the manuscript were derived from results of a multicenter study centered at the University of California in San Diego (UCSD) and funded by the National Institutes of Health, and that the manuscript by Hoshide et al. was submitted for publication without prior approval of the UCSD study center. This matter is now under discussion by the University of Hawaii, Dr. Douglas's institution, and UCSD. Pending resolution of the questions raised regarding the right of the authors to publish these data, JCM has placed publication of the final version of the manuscript on hold. It should be noted that, according to ASM policies prohibiting duplicate publication, while the Hoshide et al. manuscript remains published, JCM cannot consider papers from other participants in the multicenter study if they include essentially the same data.
Nucleolin Interacts with the Dengue Virus Capsid Protein and Plays a Role in Formation of Infectious Virus Particles
Authors: Balinsky Corey A. , Schmeisser Hana , Ganesan Sundar , Singh Kavita , Pierson Theodore C. , Zoon Kathryn C.
Published: September 2013

Dengue virus (DENV) is a mosquito-transmitted flavivirus that can cause severe disease in humans and is considered a reemerging pathogen of significant importance to public health. The DENV capsid (C) protein functions as a structural component of the infectious virion; however, it may have additional functions in the virus replicative cycle. Here, we show that the DENV C protein interacts and colocalizes with the multifunctional host protein nucleolin (NCL). Furthermore, we demonstrate that this interaction can be disrupted by the addition of an NCL binding aptamer (AS1411). Knockdown of NCL with small interfering RNA (siRNA) or treatment of cells with AS1411 results in a significant reduction of viral titers after DENV infection. Western blotting and quantitative RT-PCR (qRT-PCR) analysis revealed no differences in viral RNA or protein levels at early time points postinfection, suggesting a role for NCL in viral morphogenesis. We support this hypothesis by showing that treatment with AS1411 alters the migration characteristics of the viral capsid, as visualized by native electrophoresis. Here, we identify a critical interaction between DENV C protein and NCL that represents a potential new target for the development of antiviral therapeutics.
Differing Epidemiological Dynamics of Influenza B Virus Lineages in Guangzhou, Southern China, 2009-2010
Authors: Tan Yi , Guan Wenda , Lam Tommy Tsan-Yuk , Pan Sihua , Wu Shiguan , Zhan Yangqing , Viboud Cecile , Holmes Edward C. , Yang Zifeng
Published: September 2013

The epidemiological and evolutionary dynamics of the two cocirculating lineages of influenza B virus, Victoria and Yamagata, are poorly understood, especially in tropical or subtropical areas of Southeast Asia. We performed a phylogenetic analysis of the hemagglutinin (HA) and neuraminidase (NA) sequences of influenza B viruses isolated in Guangzhou, a southern Chinese city, during 2009 to 2010 and compared the demographic and clinical features of infected patients. We identified multiple viral introductions of Victoria strains from both Chinese and international sources, which formed two phylogenetically and antigenically distinct clades (Victoria 1 and 2), some of which persisted between seasons. We identified one dominant Yamagata introduction from outside China during 2009. Our phylogenetic analysis reveals the occurrence of reassortment events among the Victoria and Yamagata lineages and also within the Victoria lineage. We found no significant difference in clinical severity by influenza B lineage, with the exceptions that (i) the Yamagata lineage infected older people than either Victoria lineage and (ii) fewer upper respiratory tract infections were caused by the Victoria 2 than the Victoria 1 clade. Overall, our study reveals the complex epidemiological dynamics of different influenza B lineages within a single geographic locality and has implications for vaccination policy in southern China.
White Spot Syndrome Virus IE1 and WSV056 Modulate the G
1
/S Transition by Binding to the Host Retinoblastoma Protein
Authors: Ran Xiaozhuo , Bian Xiaofang , Ji Yongchang , Yan Xiumin , Yang Feng , Li Fang
Published: September 2013

DNA viruses often target cellular proteins to modulate host cell cycles and facilitate viral genome replication. However, whether proliferation of white spot syndrome virus (WSSV) requires regulation of the host cell cycle remains unclear. In the present study, we show that two WSSV paralogs, IE1 and WSV056, can interact with
Litopenaeus vannamei
retinoblastoma (Rb)-like protein (lv-RBL) through the conserved LxCxE motif. Further investigation revealed that IE1 and WSV056 could also bind to
Drosophila
retinoblastoma family protein 1 (RBF1) in a manner similar to how they bind to lv-RBL. Using the
Drosophila
RBF-E2F pathway as a model system, we demonstrated that both IE1 and WSV056 could sequester RBF1 from
Drosophila
E2F transcription factor 1 (E2F1) and subsequently activate E2F1 to stimulate the G
1
/S transition. Our findings provide the first evidence that WSSV may regulate cell cycle progression by targeting the Rb-E2F pathway.
Seminal Plasma and Semen Amyloids Enhance Cytomegalovirus Infection in Cell Culture
Authors: Tang Qiyi , Roan Nadia R. , Yamamura Yasuhiro
Published: September 2013

Among the modes of transmission available to the cytomegalovirus (CMV) is sexual transmission, primarily via semen. Both male-to-female (M-F) and male-to-male (M-M) sexual transmission significantly contribute toward the spread of CMV infections in the global population. Semen plays an important role in carrying the viral particle that invades the vaginal or rectal mucosa, thereby initiating viral replication. Both semen and seminal plasma (SP) can enhance HIV-1 infection in cell culture, and two amyloid fibrils, semen-derived enhancer of viral infection (SEVI) and amyloids derived from the semenogelins (SEM amyloids), have been identified as seminal factors sufficient to enhance HIV-1 infection (J. Munch et al., Cell131:1059–1071, 2007; N. R. Roan et al., Cell Host Microbe10:541–550, 2011; F. Arnold et al., J. Virol. 86:1244–1249, 2012). Whether SP, SEVI, or SEM amyloids can enhance other viral infections has not been extensively examined. In this study, we found that SP, SEVI, and SEM amyloids strongly enhance both human CMV (HCMV) and murine CMV infection in cell culture. SEVI and SEM amyloids increased infection rates by >10-fold, as determined by both flow cytometry and fluorescence microscopy. Viral replication was increased by 50- to 100-fold. Moreover, viral growth curve assays showed that SP, SEVI, and SEM amyloids sped up the kinetics of CMV replication such that the virus reached its replicative peak more quickly. Finally, we discovered that SEM amyloids and SEVI counteracted the effect of anti-gH in protecting against CMV infection. Collectively, the data suggest that semen enhances CMV infection through interactions between semen amyloid fibrils and viral particles, and these interactions may prevent HCMV from being neutralized by anti-gH antibody.
Human Astrocytic Cells Support Persistent Coxsackievirus B3 Infection
Authors: Zhang Xiaowei , Zheng Zhenhua , Shu Bo , Liu Xijuan , Zhang Zhenfeng , Liu Yan , Bai Bingke , Hu Qinxue , Mao Panyong , Wang Hanzhong
Published: September 2013

Enteroviruses can frequently target the human central nervous system to induce a variety of neurological diseases. Although enteroviruses are highly cytolytic, emerging evidence has shown that these viruses can establish persistent infections both
in vivo
and
in vitro
. Here, we investigated the susceptibility of three human brain cell lines, CCF-STTG1, T98G, and SK-N-SH, to infection with three enterovirus serotypes: coxsackievirus B3 (CVB3), enterovirus 71, and coxsackievirus A9. Persistent infection was observed in CVB3-infected CCF-STTG1 cells, as evidenced by prolonged detection of infectious virions, viral RNA, and viral antigens. Of note, infected CCF-STTG1 cells expressed the nonfunctional canonical viral receptors coxsackievirus-adenovirus receptor and decay-accelerating factor, while removal of cell surface chondroitin sulfate from CCF-STTG1 cells inhibited the replication of CVB3, suggesting that receptor usage was one of the major limiting factors in CVB3 persistence. In addition, CVB3 curtailed the induction of beta interferon in infected CCF-STTG1 cells, which likely contributed to the initiation of persistence. Furthermore, proinflammatory chemokines and cytokines, such as vascular cell adhesion molecule 1, interleukin-8 (IL-8), and IL-6, were upregulated in CVB3-infected CCF-STTG1 cells and human progenitor-derived astrocytes. Our data together demonstrate the potential of CCF-STTG1 cells to be a novel cell model for studying CVB3-central nervous system interactions, providing the basis toward a better understanding of CVB3-induced chronic neuropathogenesis.
A MicroRNA Encoded by Autographa californica Nucleopolyhedrovirus Regulates Expression of Viral Gene ODV-E25
Authors: Zhu Mengxiao , Wang Jinwen , Deng Riqiang , Xiong Peiwen , Liang Hai , Wang Xunzhang
Published: September 2013

Baculovirus-encoded microRNAs (miRNAs) have been described in
Bombyx mori
nucleopolyhedrovirus; however, most of their functions remain unclear. Here we report the identification and characterization of an miRNA encoded by
Autographa californica
nucleopolyhedrovirus. The identified miRNA, AcMNPV-miR-1, perfectly matched a segment in the coding sequence of the viral gene ODV-E25 and downregulated ODV-E25 mRNA expression, which likely resulted in a reduction of infectious budded virions and accelerated the formation of occlusion-derived virions.