bluuebunny/crossref_metadata_2025 huggingface dataset:
A set of metrics to assess stakeholder engagement and social legitimacy on a corporate Facebook page
Authors: Bonsón Enrique , Ratkai Melinda
Published: September 2013

Purpose

– This study aims to propose a set of metrics in order to assess reactivity, dialogic communication and stakeholder engagement (popularity, commitment and virality): stakeholders' mood and social legitimacy on corporate Facebook pages. These metrics can offer a better understanding and measurability of this social media/social network/online communication management tool.

Design/methodology/approach

– Three theories (dialogic, stakeholders and legitimacy) were considered in the development of these metrics. Empirical evidence was collected from a sample of 314 European companies. Then ten active companies were used to validate the proposed metrics on Facebook.

Findings

– The constructed set of metrics was found to be valid and efficiently usable according to the principles of the applied theories. Moreover all the proposed metrics could be adapted for such sites as Google+.

Research limitations/implications

– Limitations can only be identified within the validation process as the metrics were only applied to ten representative companies from the Eurozone.

Practical implications

– The proposed metrics will help users, marketing/PR/communication professionals and company managers to measure their and their competitors' popularity, commitment, virality (metrics which reflect stakeholder engagement), and the mood of stakeholders, and use content analysis in order to measure social legitimacy via CSR information disclosure on Facebook. Thus the online reputation of a company can be practically measured.

Originality/value

– This paper is the first proposing metrics to assess stakeholder engagement and social legitimacy on a corporate Facebook page that can be used in both academic and professional circles to a gain a better understanding of corporate online communication via Facebook.
Exploring user contributed information in social computing systems: quantity versus quality
Authors: Ye Chen , Nov Oded
Published: September 2013

Purpose

– The objective of this paper is to explore empirically the relationship between quantity and quality of user contributed information in online social computing systems, and how these two performance outcomes are associated with user factors.

Design/methodology/approach

– Drawing from prior research, the paper presents a conceptual model hypothesizing a tradeoff between quality and quantity of user contributed information. In addition quality and quantity are associated with a set of motivational, cognitive, and social factors. The model was tested using data obtained through a web-based survey of 345 users of the Flickr online photo sharing community.

Findings

– The empirical results support the hypothesized inverse relationship between quantity and quality of user contributed information, moderated by user's tenure in the community. The findings also suggest that a user's quantity of contribution is positively associated with the intrinsic motivation of commitment to the community, whereas quality of contribution is positively associated with the extrinsic motivation of self-development. While users’ social embeddedness is associated with quality and quantity of contribution, virtualness of social ties is only associated with quality of contribution.

Practical implications

– The findings of this study can inform the design and management of online communities, and promote sustained contributions from individual users.

Originality/value

– This study extends our knowledge of the quality and quantity of user contributed online information by demonstrating the inverse relationship between these two performance outcomes, and that they could be motivated by different user factors.
User satisfaction with portals: testing for factorial validity and invariance across age groups
Authors: Heo Misook
Published: September 2013

Purpose

– The goals of this study are to evaluate the factorial validity of a measurement model of cultural heritage portals and to test the model's invariance as it relates to user satisfaction.

Design/methodology/approach

– A measurement model was created by adapting multiple existing scales with the hypothesis that overall user satisfaction with a cultural heritage portal consists of satisfaction with data quality, satisfaction with service quality and users' technology acceptance. The validity of the indicator variables of each of the adapted scales was tested, then a combined measurement model was tested, via confirmatory factor analysis. The re-specified measurement model was then tested for invariance between two age groups with increasingly stringent criteria.

Findings

– The analyses indicated that the three frameworks complement each other in assessing the factors influencing user satisfaction, especially in cultural heritage portals, and that the factor structure is the same across age groups, confirming the findings of the recent online trend: some of the key internet activities such as information consumption are becoming uniformly popular across different age groups.

Originality/value

– Considering that it is not usual for non-profit organisations to assess customer satisfaction, and there exists limited literature examining factors influencing user satisfaction with cultural heritage portals, especially with different age populations, the findings of the current study provide a valuable contribution to the literature. The study also benefits practitioners in the field by providing a framework to assess user satisfaction with existing cultural heritage portals and/or to build cultural heritage portals in a way that increases users' satisfaction, regardless of age group.
Prioritizing global marine mammal habitats using density maps in place of range maps
Authors: Williams Rob , Grand Joanna , Hooker Sascha K. , Buckland Stephen T. , Reeves Randall R. , Rojas‐Bracho Lorenzo , Sandilands Doug , Kaschner Kristin
Published: September 2013

Despite lessons from terrestrial systems, conservation efforts in marine systems continue to focus on identifying priority sites for protection based on high species richness inferred from range maps. Range maps oversimplify spatial variability in animal distributions by assuming uniform distribution within range and de facto giving equal weight to critical and marginal habitats. We used Marxan ver. 2.43 to compare species richness‐based systematic reserve network solutions using information about marine mammal range and relative abundance. At a global scale, reserve network solutions were strongly sensitive to model inputs and assumptions. Solutions based on different input data overlapped by a third at most, with agreement as low as 10% in some cases. At a regional scale, species richness was inversely related to density, such that species richness hotspots excluded highest‐density areas for all species. Based on these findings, we caution that species‐richness estimates derived from range maps and used as input in conservation planning exercises may inadvertently lead to protection of largely marginal habitat.
Does Experience Facilitate Entry into New Export Destinations?
Authors: Wang Lili , Zhao Yong
Published: September 2013

Using a large panel dataset that covers 116 countries and 5013 products over the period 1998–2010, this study evaluates the effects of export experience on the geographic expansion of China's exports. The results suggest that past export experience in geographically close and culturally similar markets plays a crucial role in facilitating new market entry, and the positive spillover effects are more pronounced for incumbent and successful products. The results also indicate that spillovers from export experience are market‐specific and product‐specific, and they are limited to within the same product class and the same market, with little cross‐group effects. Finally, there is no strong evidence that export experience is more important for differentiated products than for homogeneous products, and the positive spillover effects are remarkable for both categories of products.
Population Aging and Housing Consumption: A Nonlinear Relationship in China
Authors: Li Meng , Shen Kunrong
Published: September 2013

Mass migration of rural workers to cities will inevitably increase urban housing demand. However, the scale of vacant urban housing will increase in future as a result of the population aging and the rising number of empty nesters. Therefore, demographic transition may not only increase housing demand, but also increase housing supply. Using an overlapping generations model, the present paper investigates the impact of demographic transition on housing consumption. We find that there is a nonlinear relationship between the elderly dependency ratio and housing consumption in China. With the deepening of population aging, housing consumption will increase; when the elderly dependency ratio reaches a turning point, housing consumption will decrease. The turning point of the nonlinear curve also depends on population mobility. A greater degree of population mobility will result in a delayed turning point. Furthermore, the turning point of the nonlinear curve will emerge when China's elderly dependency ratio reaches a value of 32 percent in 2025. This means that over the next decade, China should continue to increase the level of housing supply.
Emerging Geography of Creativity and Labor Productivity Effects in China
Authors: Yu Wentao , Hong Jin , Wu Yanrui , Zhao Dingtao
Published: September 2013

The paper presents an alternative approach to explain why regional productivity is different across regions by utilizing the creative class approach in China. First, we analyze the extent of spatial agglomeration of the creative class across regions in China. Second, we develop a model with spatial externalities to investigate how the concentration of the creative class can promote regional productivity. Our analysis confirms the importance of spatial agglomeration of the creative class in stimulating regional productivity. The results also imply that regional productivity is greater in markets with higher levels of innovation, capital stock, manufacturing and urbanization. In light of the results of our analysis, we discuss a number of policy implications.
Giving Peace a Chance: National Reconciliation and a Neutral South Vietnam, 1954–1964
Authors: Quinn‐Judge Sophie
Published: September 2013

Early discussions of establishing a neutral South Vietnam started during the Geneva Conference in 1954. Vietnamese negotiator Phạm Văn Đồng met southern leaders, including Bảo Đại's former prime minister Trần Văn Hửu and the Cao Đài leader Phạm Công Tắc, who hoped to form such a government with French backing. These southerners pledged to open relations with the DRV, but they were pushed out of the picture by Ngô Đình Diệm, who with U.S. support became the southern prime minister and then president. Although these early efforts to create a neutral South Vietnam and promote national unity failed, the southern communists’ 1956 “Theses on the Path to Revolution” supported peaceful political struggle to unify Vietnam. Ideas of neutralism were viewed as communist propaganda by most U.S. statesmen and their allies in South Vietnam. Yet there were large numbers of native southerners who viewed the creation of a civilian coalition government as a desirable step, to avoid an American‐sponsored war on their soil. In this article, I show how these various neutralist groups, later known as the “Third Segment,” attempted to avoid a civil war that would entangle them in the Cold War.
The Question of Reconciliation in Vietnam: A Relevant Social Issue
Authors: Quang Trần Hũu
Published: September 2013

The aim of this paper is to try to identify some main types of polarization in the social consciousness of postwar Vietnam and to put forth some ideas about the necessity to further the reconciliation process in hopes of providing the groundwork for a modern state and a modern society.
Military Victory and the Difficult Tasks of Reconciliation in Vietnam: A Cautionary Tale
Authors: Long Ngô Vĩnh
Published: September 2013

The problems of reconciliation and accommodation following the Vietnam War are still extremely pronounced. Polarization in social, economic, and ideological terms created by the long war is still evident. Repression of civil society during the war and military “victory” created difficulties for national reconciliation, integration, and development.
Field‐based experimental evolution of three cereal pathogens using a mark–release–recapture strategy
Authors: Zhan J. , McDonald B. A.
Published: September 2013

Field‐based experimental evolution is a research approach in which study species are allowed to evolve across several generations under well‐defined field conditions. Field‐based experiments in pathogen evolution became feasible with advances in molecular markers and computing technologies. Critical to success of these experiments is the choice of parental genotypes, molecular markers, experimental sites and field plot design. The current study used field‐based experimental evolution based on a mark–release–recapture strategy to analyse the dynamics of interstrain competition and host specialization in the cereal pathogens Zymoseptoria tritici, Phaeosphaeria nodorum and Rhynchosporium commune. In all three pathogen–plant interactions, compelling evidence was found indicating that increasing host heterogeneity by growing cultivar mixtures slowed down the evolution of the corresponding pathogen populations. Evidence for differential selection between parasitic and saprophytic phases of the life cycle in P. nodorum and R. commune was also found. The effect of partial resistance on the evolution of the experimental pathogen populations was mixed. A decreased rate of evolution was found in the pathogen populations sampled from partially resistant hosts in Z. tritici and P. nodorum but not R. commune. The findings indicate that field‐based experimental evolution offers a powerful approach to test hypotheses associated with the evolution of plant pathogens.
Higher torsion in the Abelianization of the full Bianchi groups
Authors: Rahm Alexander D.
Published: September 2013

Denote by $ \mathbb{Q} ( \sqrt{- m} )$, with $m$ a square-free positive integer, an imaginary quadratic number field, and by ${ \mathcal{O} }_{- m} $ its ring of integers. The Bianchi groups are the groups ${\mathrm{SL} }_{2} ({ \mathcal{O} }_{- m} )$. In the literature, so far there have been no examples of $p$-torsion in the integral homology of the full Bianchi groups, for $p$ a prime greater than the order of elements of finite order in the Bianchi group, which is at most 6. However, extending the scope of the computations, we can observe examples of torsion in the integral homology of the quotient space, at prime numbers as high as for instance $p= 80\hspace{0.167em} 737$ at the discriminant $- 1747$.

Supplementary materials are available with this article.
Evaluation of Feedback Enabled Active Colonoscopy Training Model
Authors: Kale Ravindra , Koonce David , Drozek David , Choi JungHun
Published: September 2013

The objective of this research is to evaluate the efficacy of an active colonoscopy training model (ACTM). Colonoscopy is a widely utilized procedure for diagnosing diseases of the lower gastrointestinal tract. Since colonoscopy is a difficult procedure to teach, as well as learn, simulators are often used to teach and practice the procedure. To make learning and assessing the procedural skills easy and interactive, an active training model was developed and evaluated. To measure the applied force and the time to complete the procedure, load cells and light detecting sensors were installed in the training model and were interfaced with a data acquisition system. The user interface was programmed in LabVIEW to record the force data and time taken to complete the procedure. Thirty medical students were recruited to perform a series of three colonoscopies on the ACTM. These students were instructed how to handle the equipment and perform the colonoscopy. The procedure was also performed by experienced endoscopists to establish a benchmark. The collected data were analyzed to determine the effectiveness of the device to (1) distinguish between the participants based on their level of expertise, and (2) to detect improvement in skill of the students with repetitive sessions with the device. The results of this research may be useful to show that the ACTM may be an effective tool to integrate in to the medical training program of medical studies. It can be possibly used for evaluating the skill sets, as well as practicing the procedure before a novice surgeon performs the procedure on a patient.
Design of a Nasal Septum Measurement Device
Authors: Sooklal Valmiki K. , Hooper Luke , Larson Michael C.
Published: September 2013

Nasal septal deviation occurs in approximately 20% of the population (Blaugrand, S., 1989, “The Nasal Septum and Concha Bullosa,” Otolaryngol. Clin. North Am., 22, pp. 291–306). Depending on the severity of the deviation, the natural flow of air through the nasal passages can be obstructed, possibly leading to more advanced complications such as epistaxis, rhinorrhoea, postnasal drip, recurrent sinus pain, chronic nasal obstruction, obstructive sleep apnea, and increased risk of viral or bacterial infections. Numerous measurement techniques exist to assess nasal patency and identify any nasal occlusion including deviated septums such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans. However, there is no cost effective, user friendly method that attempts to measure the thickness of the septum. The design, fabrication, and operation of an easy-to-use and inexpensive device, which can be used quickly to measure nasal septal thickness post surgery and in follow up appointments is described. The device enables physicians to efficiently build a database of measures that can yield a new understanding of surgery effects. Measurements obtained using the new device are presented for five patients undergoing septoplasty surgery. It proved to be a fast and economical way to determine septal thickness. Initial results taken in pre, intra, and post surgery yielded results confirming the efficacy of the device as an efficient evaluation tool capable of giving instantaneous results of nasal septum geometry. The device achieves its intended function while keeping the product cost low. Early results also showed the efficacy in obtaining data on septoplasty surgery efficacy and septal swelling as a result of external factors such as histamines.
Tissue Translocation Device for Surgical Correction of Age-Related Macular Degeneration
Authors: Mathai George , Rosen David , Melkote Shreyes , Olsen Timothy
Published: September 2013

Age-related macular degeneration (AMD) is the leading cause of blindness in the western world in those over age 60. While this disorder is complex, the origin of injury appears to be at the level of the retinal pigment epithelium (RPE), Bruchs membrane, and inner choroid. A potential method to replace damaged tissue in AMD is to harvest healthy donor tissue (RPE-Bruchs-Choroid) from an eye and translocate it to the injured subretinal region. Such an autograft avoids immune mediated rejection and can theoretically restore function to the neurosensory retina (light sensitive part of the retina) by restoring the damaged tissue. Such a procedure requires the design of a device that mechanically supports the integrity of the graft while inside the eye, without injuring or disrupting the tissue. This paper presents the systematic design and manufacture of a thin shape memory foil-based tissue translocation device. The selected embodiment of the design uses thermal adhesion of the tissue to the foil surfaces for tissue support. The shape memory effect enables insertion of the device into the eye via a small incision. The device is manufactured using micromachining techniques and has been tested both ex vivo and in vivo with acceptable anatomic results.
Application of a Maneuvering Propulsor Technology to Undersea Vehicles
Authors: Huyer Stephen A.
Published: September 2013

Previous computational and experimental studies that have demonstrated a method to generate vehicle maneuvering forces from a propulsor alone have been applied to a generic undersea vehicle. An open, preswirl propulsor was configured with an upstream stator row and downstream rotor. During normal operation, the upstream stator blades are all situated at the same pitch angle and preswirl the flow into the propulsor while generating a roll moment to counter the torque produced by the rotor. By varying the pitch angles of the stator blade about the circumference, it is possible to generate a mean stator side force that can be used to maneuver the vehicle. The stator wake axial velocity and swirl that is ingested into the rotor produces a counter-force by the rotor. Optimal design of the rotor minimizes the unsteady force and redirects the rotor force vector in an orthogonal direction to minimize the counter force. The viscous, 3D Reynolds-averaged Navier–Stokes (RANS) commercial code FLUENT® was used to predict the stator forces, velocity fields, and rotor response. Radiated noise was computed for the rotor separately and the entire geometry utilizing the Ffowcs Williams–Hawkings module available in FLUENT. Two separate geometries were studied—the first with a maximum stator blade row diameter contained within the body diameter and a second that was allowed to exceed the body diameter. Side force coefficients were computed for the two maneuvering propulsor configurations and compared with currently used control surface forces. Computations predicted that the maneuvering propulsor generated side forces equivalent to those produced by conventional control surfaces with side force coefficients on the order of 0.3. This translates to 50% larger forces than can be generated by conventional control surfaces on 21 in. unmanned undersea vehicles. Radiated noise calculations in air demonstrated that the total sound pressure levels produced by the maneuvering propulsor were on the order of 5 dB lower than the control fin test cases.
A New Approach for the Stability Analysis of Rotors Supported by Gas Bearings
Authors: Hassini Mohamed Amine , Arghir Mihai
Published: September 2013

A simplified nonlinear transient analysis method for gas bearings was recently published by the authors (Hassini, M. A., and Arghir, M., 2012, “Simplified Nonlinear Transient Analysis Method for Gas Bearings,” J. Tribol., 134(1), 011704). The method uses the fact that linearized dynamic characteristics of gas bearings, namely the impedances, can be approximated by rational transfer functions. The method gave good results if the rational transfer function approach approximated the linearized dynamic characteristics well. Indeed, each of the four complex impedances Zαβ,α,β={x,y} had one or two poles depending on the order of the rational function that were used. These poles appear as supplementary eigenvalues of the extended matrix of the homogeneous system of first order differential equations describing the model of the rotor. They govern the stability of the dynamic model in the same way as the original eigenvalues do and therefore they impose non-negligible constraints on the rational function approximation of the impedances of gas bearings. The present improvement of the method overrides this problem. The basic idea is to impose the same set of poles for Zxx, Zxy, Zyx, and Zyy. By imposing this constraint, the poles are stable and the introduction of artificial instability or erratic eigenvalues is avoided. Campbell and stability diagrams naturally taking into account the variation of the dynamic coefficients with the excitation frequency can now be easily plotted. For example, the method is used for analyzing the stability of rigid and flexible rotors supported by two identical gas bearings modeled with second order rational transfer functions. The method can be applied to any bearing or seal whose impedance is approximated by rational transfer functions.
Alternative Convolution Approach to Friction in Unsteady Pipe Flow
Authors: Szymkiewicz Romuald , Mitosek Marek
Published: September 2013

In this paper some aspects of the unsteady friction in pipe flow expressed by the convolution are analyzed. This additional term introduced into the motion equation involves the accelerations of fluid occurring in the past and a weighting function. The essence of such approach is to assume the appropriate form of weighting function. However, until now, no fully reliable formula for this function has been found. To avoid some inconveniences typical for the commonly used weighting functions, an alternative form of the convolution is proposed. Instead of a weighting function an impulse response function in a general form is introduced. This function, defined in the real time domain, having clear physical interpretation and some useful properties is not related to the usually assumed viscosity distribution over the pipe's cross section. The proposed approach involves two parameters. The convergence of the impulse response function, characterized by the flow memory, is determined by a parameter which can be related to the pressure wave frequency. The second parameter determines the magnitude of the unsteady friction force. The proposed alternative convolution approach was tested basing on the laboratory measurements for a water hammer event initiated by turbulent flow in pipes made of steel. Although the alternative convolution approach causes a very good damping of the pressure wave amplitude, it appears to be unable to ensure appropriate smoothing of the pressure heads. This is because it acts in the dynamic equation as a source/sink term. To ensure the required smoothing of the pressure wave the diffusive term was included into the dynamic equation.
Economic Optimization of a Concentrating Solar Power Plant With Molten-Salt Thermocline Storage
Authors: Flueckiger Scott M. , Iverson Brian D. , Garimella Suresh V.
Published: September 2013

System-level simulation of a molten-salt thermocline tank is undertaken in response to year-long historical weather data and corresponding plant control. Such a simulation is enabled by combining a finite-volume model of the tank that includes a sufficiently faithful representation at low computation cost with a system-level power tower plant model. Annual plant performance of a 100 MWe molten-salt power tower plant is optimized as a function of the thermocline tank size and the plant solar multiple (SM). The effectiveness of the thermocline tank in storing and supplying hot molten salt to the power plant is found to exceed 99% over a year of operation, independent of tank size. The electrical output of the plant is characterized by its capacity factor (CF) over the year, which increases with solar multiple and thermocline tank size albeit with diminishing returns. The economic performance of the plant is characterized with a levelized cost of electricity (LCOE) metric. A previous study conducted by the authors applied a simplified cost metric for plant performance. The current study applies a more comprehensive financial approach and observes a minimum cost of 12.2 ¢/kWhe with a solar multiple of 3 and a thermocline tank storage capacity of 16 h. While the thermocline tank concept is viable and economically feasible, additional plant improvements beyond those pertaining to storage are necessary to achieve grid parity with fossil fuels.
1-Hexanol Based Catalyst Inks for Catalyst Layer Preparation for a
DMFC
Authors: Hürter S. , Wannek C. , Müller M. , Stolten D.
Published: September 2013

The catalyst ink preparation for a catalyst layer production by screen printing for a direct methanol fuel cell (DMFC) is evaluated. Among a large variety of solvents 1-hexanol was chosen for the preparation due to its properties fitting the requirements for the ink preparation. 1-hexanol based catalyst inks lead to thicker catalyst layers compared to isopropyl-/propylalcohol based catalyst inks, currently used in-house. Despite showing different layer properties, MEAs based on 1-hexanol or isopropyl-/propylalcohol based catalyst layers show comparable electrochemical performances. When using 1-hexanol based catalyst inks the dispersion procedure shows great influence on the outcoming catalyst layer. Long dispersion periods and a medium power output of ultrasonication of the catalyst dispersion are beneficial and lead to good coating qualities of the catalyst layer and therefore to high electrochemical performances.
Microscale Drilling of Bulk Metallic Glass
Authors: Zhu James , Kim Hyun Jin , Kapoor Shiv G.
Published: September 2013

The microscale drilling performance of a Zr-based bulk metallic glass (BMG) is investigated in this paper. Crystallization, drill temperature, axial force, spindle load (SL), acoustic emissions (AE), chip morphology, hole diameter, and entry burr height are measured and analyzed with varying cutting speed and chip load. The progression of tool wear is assessed using stereo-microscopy techniques. At small chip loads, minimum chip thickness (MCT) is observed to shift cutting mechanics from a shear-dominated to a ploughing-dominated regime. Consequently, evidence of drill instability and larger burr height are observed. As drilling temperatures rise above the glass transition temperature, the BMG thermally softens due to the transition to a super-cooled liquid state and begins to exhibit viscous characteristics. In the tool wear study using tungsten carbide microdrills, rake wear is found to dominate compared to flank wear. This is attributed to a combination of a high rate of diffusion wear on the rake face as well as lower abrasion on the flank due to the decreased hardness from thermal softening-induced viscous flow of BMG.
Validation of mathematical models for the prediction of organs‐at‐risk dosimetric metrics in high‐dose‐rate gynecologic interstitial brachytherapy
Authors: Damato Antonio L. , Viswanathan Akila N. , Cormack Robert A.
Published: September 2013

Purpose:

Given the complicated nature of an interstitial gynecologic brachytherapy treatment plan, the use of a quantitative tool to evaluate the quality of the achieved metrics compared to clinical practice would be advantageous. For this purpose, predictive mathematical models to predict the D2cc of rectum and bladder in interstitial gynecologic brachytherapy are discussed and validated.

Methods:

Previous plans were used to establish the relationship between D2cc and the overlapping volume of the organ at risk with the targeted area (C0) or a 1‐cm expansion of the target area (C1). Three mathematical models were evaluated: D2cc = α*C1 + β (LIN); D2cc = α – exp(–β*C0) (EXP); and a mixed approach (MIX), where both C0 and C1 were inputs of the model. The parameters of the models were optimized on a training set of patient data, and the predictive error of each model (predicted D2cc − real D2cc) was calculated on a validation set of patient data. The data of 20 patients were used to perform a K‐fold cross validation analysis, with K = 2, 4, 6, 8, 10, and 20.

Results:

MIX was associated with the smallest mean prediction error <6.4% for an 18‐patient training set; LIN had an error <8.5%; EXP had an error <8.3%. Best case scenario analysis shows that an error ≤5% can be achieved for a ten‐patient training set with MIX, an error ≤7.4% for LIN, and an error ≤6.9% for EXP. The error decreases with the increase in training set size, with the most marked decrease observed for MIX.

Conclusions:

The MIX model can predict the D2cc of the organs at risk with an error lower than 5% with a training set of ten patients or greater. The model can be used in the development of quality assurance tools to identify treatment plans with suboptimal sparing of the organs at risk. It can also be used to improve preplanning and in the development of real‐time intraoperative planning tools.
Science Signaling
Podcast: 24 September 2013
Authors: Miller Martin L. , Sander Chris , VanHook Annalisa M.
Published: September 2013

Drug screening and network modeling suggest a combination therapy for liposarcoma.
Pain and Dependence
Authors: Stern Peter R.
Published: September 2013

Transient inflammation can lead to prolonged activation of pain-relieving opioid receptors in the spinal cord.
Combining Anti-Inflammatory and Anti-Angiogenic Therapy
Authors: Wong Wei
Published: September 2013

Targeting the cytokine IL-17 could attenuate the resistance that tumors develop to therapies that block angiogenesis.
Identification of MMV Malaria Box Inhibitors of Plasmodium falciparum Early-Stage Gametocytes Using a Luciferase-Based High-Throughput Assay
Authors: Lucantoni Leonardo , Duffy Sandra , Adjalley Sophie H. , Fidock David A. , Avery Vicky M.
Published: September 2013

The design of new antimalarial combinations to treat
Plasmodium falciparum
infections requires drugs that, in addition to resolving disease symptoms caused by asexual blood stage parasites, can also interrupt transmission to the mosquito vector. Gametocytes, which are essential for transmission, develop as sexual blood stage parasites in the human host over 8 to 12 days and are the most accessible developmental stage for transmission-blocking drugs. Considerable effort is currently being devoted to identifying compounds active against mature gametocytes. However, investigations on the drug sensitivity of developing gametocytes, as well as screening methods for identifying inhibitors of early gametocytogenesis, remain scarce. We have developed a luciferase-based high-throughput screening (HTS) assay using tightly synchronous stage I to III gametocytes from a recombinant
P. falciparum
line expressing green fluorescent protein (GFP)-luciferase. The assay has been used to evaluate the early-stage gametocytocidal activity of the MMV Malaria Box, a collection of 400 compounds with known antimalarial (asexual blood stage) activity. Screening this collection against early-stage (I to III) gametocytes yielded 64 gametocytocidal compounds with 50% inhibitory concentrations (IC
50
s) below 2.5 μM. This assay is reproducible and suitable for the screening of large compound libraries, with an average percent coefficient of variance (%CV) of ≤5%, an average signal-to-noise ratio (S:N) of >30, and a Z′ of ∼0.8. Our findings highlight the need for screening efforts directed specifically against early gametocytogenesis and indicate the importance of experimental verification of early-stage gametocytocidal activity in the development of new antimalarial candidates for combination therapy.
Activity of Tigecycline in Combination with Colistin, Meropenem, Rifampin, or Gentamicin against KPC-Producing Enterobacteriaceae in a Murine Thigh Infection Model
Authors: Michail George , Labrou Maria , Pitiriga Vassiliki , Manousaka Styliani , Sakellaridis Nikolaos , Tsakris Athanasios , Pournaras Spyros
Published: September 2013

Limited antimicrobials remain active for treating severe infections due to KPC-producing pathogens, and optimal regimens have not been established. In murine thigh infections caused by nine KPC-producing clinical strains of
Enterobacteriaceae
(meropenem MICs, 1 to 4 μg/ml), we evaluated the activities of tigecycline, colistin, meropenem, rifampin, and gentamicin in single and combination regimens lasting for 24 h and 48 h. Rifampin, tigecycline, and gentamicin were the most effective monotherapies, reducing significantly the CFU counts yielded from thighs infected by 88.9 to 100%, 77.8 to 88.9%, and 66.7 to 88.9% of strains, respectively; meropenem and colistin alone exhibited considerably lower performance (significant CFU reduction in 33.3% and 22.2 to 33.3% of the strains, respectively). The addition of rifampin or gentamicin to tigecycline produced synergistic effect in most strains, while antagonism was observed in 33.3 to 44.4% of the strains when colistin was added to tigecycline and in 44.4 to 55.5% of the strains for meropenem combination with tigecycline. Tigecycline combinations with gentamicin or with rifampin caused higher CFU reductions than did tigecycline plus colistin or plus meropenem with almost all strains. Furthermore, tigecycline plus gentamicin was significantly more effective than tigecycline plus colistin or tigecycline plus meropenem in 33.3 to 44.4% and 55.5 to 66.7% of the strains, respectively, while tigecycline plus rifampin significantly outperformed tigecycline plus colistin and tigecycline plus meropenem in 33.3% and 66.7 to 77.8% of the strains, respectively. Overall, our
in vivo
study showed that tigecycline plus rifampin or plus gentamicin is a robust regimen against soft tissue infections caused by KPC-producing strains. The combinations of tigecycline with colistin or meropenem should be considered with caution in clinical practice.
Whole-Cell Screening-Based Identification of Inhibitors against the Intraphagosomal Survival of Mycobacterium tuberculosis
Authors: Khare Garima , Kumar Praveen , Tyagi Anil K.
Published: September 2013

We describe here an efficient strategy that employs whole-cell-based screening and further short listing of the compounds by cytotoxicity- and fluorescence-based intracellular assays, resulting in potential bactericidal hits against the growth of
Mycobacterium tuberculosis
in broth culture as well as in phagosomes. These compounds also inhibited multidrug-resistant strains of
M. tuberculosis
but showed no or poor inhibition of nonpathogenic mycobacteria or other bacterial species such as
Escherichia coli
.
Gallium Nitrate Is Efficacious in Murine Models of Tuberculosis and Inhibits Key Bacterial Fe-Dependent Enzymes
Authors: Olakanmi Oyebode , Kesavalu Banurekha , Pasula Rajamouli , Abdalla Maher Y. , Schlesinger Larry S. , Britigan Bradley E.
Published: September 2013

Acquiring iron (Fe) is critical to the metabolism and growth ofMycobacterium tuberculosis. Disruption of Fe metabolism is a potential approach for novel antituberculous therapy. Gallium (Ga) has many similarities to Fe. Biological systems are often unable to distinguish Ga3+from Fe3+. Unlike Fe3+, Ga3+cannot be physiologically reduced to Ga2+. Thus, substituting Ga for Fe in the active site of enzymes may render them nonfunctional. We previously showed that Ga inhibits growth ofM. tuberculosisin broth and within cultured human macrophages. We now report that Ga(NO3)3shows efficacy in murine tuberculosis models. BALB/c SCID mice were infected intratracheally withM. tuberculosis, following which they received daily intraperitoneal saline, Ga(NO3)3, or NaNO3. All mice receiving saline or NaNO3died. All Ga(NO3)3-treated mice survived.M. tuberculosisCFU in the lungs, liver, and spleen of the NaNO3-treated or saline-treated mice were significantly higher than those in Ga-treated mice. When BALB/c mice were substituted for BALB/c SCID mice as a chronic (nonlethal) infection model, Ga(NO3)3treatment significantly decreased lung CFU. To assess the mechanism(s) whereby Ga inhibits bacterial growth, the effect of Ga onM. tuberculosisribonucleotide reductase (RR) (a key enzyme in DNA replication) and aconitase activities was assessed. Ga decreasedM. tuberculosisRR activity by 50 to 60%, but no additional decrease in RR activity was seen at Ga concentrations that completely inhibited mycobacterial growth. Ga decreased aconitase activity by 90%. Ga(NO3)3shows efficacy in murineM. tuberculosisinfection and leads to a decrease in activity of Fe-dependent enzymes. Additional work is warranted to further define Ga's mechanism of action and to optimize delivery forms for possible therapeutic uses in humans.
Characterization of a Novel Fusion Protein from IpaB and IpaD of Shigella spp. and Its Potential as a Pan-Shigella Vaccine
Authors: Martinez-Becerra Francisco J. , Chen Xiaotong , Dickenson Nicholas E. , Choudhari Shyamal P. , Harrison Kelly , Clements John D. , Picking William D. , Van De Verg Lillian L. , Walker Richard I. , Picking Wendy L.
Published: September 2013

Shigellosis is an important disease in the developing world, where about 90 million people become infected with
Shigella
spp. each year. We previously demonstrated that the type three secretion apparatus (T3SA) proteins IpaB and IpaD are protective antigens in the mouse lethal pulmonary model. In order to simplify vaccine formulation and process development, we have evaluated a vaccine design that incorporates both of these previously tested
Shigella
antigens into a single polypeptide chain. To determine if this fusion protein (DB fusion) retains the antigenic and protective capacities of IpaB and IpaD, we immunized mice with the DB fusion and compared the immune response to that elicited by the IpaB/IpaD combination vaccine. Purification of the DB fusion required coexpression with IpgC, the IpaB chaperone, and after purification it maintained the highly α-helical characteristics of IpaB and IpaD. The DB fusion also induced comparable immune responses and retained the ability to protect mice against
Shigella flexneri
and
S. sonnei
in the lethal pulmonary challenge. It also offered limited protection against
S. dysenteriae
challenge. Our results show the feasibility of generating a protective
Shigella
vaccine comprised of the DB fusion.
Substrate Specificity and Function of the Pheromone Receptor AinR in Vibrio fischeri ES114
Authors: Kimbrough John H. , Stabb Eric V.
Published: September 2013

Two distinct but interrelated pheromone-signaling systems, LuxI/LuxR and AinS/AinR, positively control bioluminescence in
Vibrio fischeri
. Although each system generates an acyl-homoserine lactone (AHL) signal, the protein sequences of LuxI/LuxR and AinS/AinR are unrelated. AinS and LuxI generate the pheromones
N
-octanoyl-AHL (C
8
-AHL) and
N
-3-oxo-hexanoyl-AHL (3OC
6
-AHL), respectively. LuxR is a transcriptional activator that responds to 3OC
6
-AHL, and to a lesser extent to C
8
-AHL. AinR is hypothesized to respond to C
8
-AHL and, based on homology to
Vibrio harveyi
LuxN, to mediate the repression of a Qrr regulatory RNA. However, a Δ
ainR
mutation decreased luminescence, which was not predicted based on
V. harveyi
LuxN, raising the possibility of a distinct regulatory mechanism for AinR. Here we show that
ainR
can complement a
luxN
mutant, suggesting functional similarity. Moreover, in
V. fischeri
, we observed
ainR
-dependent repression of a P

qrr

-
lacZ
transcriptional reporter in the presence of C
8
-AHL, consistent with its hypothesized regulatory role. The system appears quite sensitive, with a half-maximal effect on a P

qrr

reporter at 140 pM C
8
-AHL. Several other AHLs with substituted and unsubstituted acyl chains between 6 and 10 carbons also displayed an AinR-dependent effect on P

qrr

-
lacZ
; however, AHLs with acyl chains of four carbons or 12 or more carbons lacked activity. Interestingly, 3OC
6
-AHL also affected expression from the
qrr
promoter, but this effect was largely
luxR
dependent, indicating a previously unknown connection between these systems. Finally, we propose a preliminary explanation for the unexpected luminescence phenotype of the Δ
ainR
mutant.
Facial and neck hematoma after carotid artery stenting: an uncommon misadventure in endovascular carotid revascularization
Authors: Grandhi Ramesh , Gande Abhiram , Zwagerman Nathan Thomas , Jankowitz Brian Thomas
Published: September 2013

The complication rates of carotid artery stenting (CAS) vary from 3.0% to 4.4%, and most commonly include ischemic stroke, intracranial hemorrhage, or groin complications. We present the rare complication of a patient who underwent CAS for a symptomatic 90% left internal carotid artery stenosis and developed an expanding cervical hematoma after the procedure with imminent respiratory compromise. After intubation, an arteriogram revealed perforation of the external carotid artery trunk, proximal to the origin of the internal maxillary artery. The artery was subsequently embolized and the hematoma resolved without further intervention. We present a potential catastrophic complication and suggest potential causes and treatment options available.
Evidence for cytomegalovirus-induced haemophagocytic syndrome in a young patient with AIDS
Authors: Ohkuma Kosuke , Saraya Takeshi , Sada Mitsuru , Kawai Shin
Published: September 2013

A 29-year-old man with HIV infection was referred to our department because of a 1-month history of low-grade fever and fatigue. Bone marrow aspiration and biopsy showed findings consistent with haemophagocytic syndrome (HPS), and immunohistochemical assessment showed cytomegalovirus (CMV) infection. HIV-associated HPS can occur at any stages of HIV disease and requires diverse differential diagnosis. CMV-associated HPS (CMV-HPS) in patients with HIV infection is relatively rare, but the present case showed that the clinicians should consider the possibility of CMV-HPS as a clinical feature of CMV infection.
A qualitative study examining the influences on situation awareness and the identification, mitigation and escalation of recognised patient risk
Authors: Brady Patrick W , Goldenhar Linda M
Published: September 2013

Background

Situation awareness (SA)—the perception of data elements, comprehension of their meaning and projection of their status in the near future—has been associated with human performance in high-risk environments, including aviation and the operating room. The influences on SA in inpatient medicine are unknown.

Methods

We conducted seven focus groups with nurses, respiratory therapists and resident physicians using a standardised semistructured focus group guide to promote discussion. Recordings of the focus groups were transcribed verbatim, and transcripts were qualitatively analysed by two independent reviewers to identify convergent and divergent themes.

Results

Three themes emerged: (1) team-based care, (2) availability of standardised data and (3) standardised processes and procedures. We categorised these into social, technological and organisational influences on SA. Subthemes that emerged from each focus group were shared language to describe at-risk patients, provider experience in critical care/deterioration and interdisciplinary huddles to identify and plan for at-risk patients. An objective early warning score, proactive assessment and planning, adequate clinician staffing and tools for entering, displaying and monitoring data trends were identified by six of seven groups. Our data better reflected the concepts of team SA and shared SA than individual SA.

Conclusions

Team-based care and standardisation support SA and the identification and treatment of patient risk in the complex environment of inpatient care. These findings can be used to guide the development and implementation of targeted interventions such as huddles to proactively scan for risk and electronic health record displays of data trends.
Epithelial–mesenchymal transition phenotypes are associated with patient survival in intrahepatic cholangiocarcinoma
Authors: Gu Mi Jin , Choi Joon Hyuk
Published: September 2013

Background

The aim of this study was to evaluate the epithelial–mesenchymal transition (EMT) and to assess its prognostic significance in intrahepatic cholangiocarcinoma.

Methods

We performed immunohistochemical stainings for E-cadherin, β-catenin, vimentin and fibronectin in a total of 85 cases.

Results

Expression of vimentin and reduced expression of E-cadherin were found to show correlation with poor differentiation (p=0.017, p=0.010). Reduced expression of β-catenin showed significant association with poor differentiation (p=0.023), tumour size (p=0.028) and lymph node metastasis (p=0.011). According to the expression pattern of E-cadherin, β-catenin, vimentin and fibronectin we categorised four phenotypes: complete type, hybrid type, null type and wild type. The complete type of β-catenin with vimentin or fibronectin was found to show an association with lymph node metastasis (p=0.048, p=0.012). Significantly worse overall survival (OS) and disease-free survival (DFS) was observed for the complete type, and the best OS and DFS were observed for the wild type.

Conclusions

EMT phenotypes can be useful markers for prediction of patient outcomes.