bluuebunny/crossref_metadata_2025 huggingface dataset:
Does ondansetron have an effect on intramuscular ketamine‐associated vomiting in children? A prospective, randomised, open, controlled study
Authors: Lee Ji Sook , Jeon Woo Chan , Park Eun Jung , Min Young Gi , Kim Gi Woon , Jung Yoon Seok , Choi Sang Cheon
Published: February 2014

Aim

Ketamine is one of the most commonly used sedatives for facilitating painful procedures for paediatric patients in the emergency department (ED). However, the use of ketamine is associated with a common, though not serious, adverse event usually called ketamine‐associated vomiting (KAV). The purpose of this study is to evaluate the anti‐emetic effect of adjunctive ondansetron in paediatric patients receiving ketamine sedation in the ED.

Methods

We conducted a prospective, randomised, open, controlled study in children from 1 to 18 years of age who had undergone intramuscular ketamine sedation in the ED. The patients were randomised into two groups: a ketamine‐only group and a ketamine/ondansetron group. The patients in the first group received ketamine alone, while those in the second group received ketamine with oral ondansetron. The incidence of KAV was estimated in the ED and after discharge, and the time to resumption of a normal diet was measured after sedation.

Results

A total of 237 patients were analysed. The incidence of KAV was 29.7% in the ketamine‐only group and 25.2% in the ketamine/ondansetron group (P = 0.47). After administration of ketamine, the mean time to resumption of a normal diet was 8 h 54 min in the ketamine‐only group and 8 h 39 min in the ketamine/ondansetron group (P = 0.67).

Conclusions

A relatively high rate of KAV (29.7%) was observed, and the time to resumption of a normal diet after ketamine sedation was rather long. It turned out that, however, the adjunctive administration of ondansetron did not effectively reduce the incidence of KAV.
The relationship between procrastination, delay of gratification, and job satisfaction among high school teachers
Authors: Mohsin Falak Zehra , Ayub Nadia
Published: February 2014

The present study aimed at determining whether a significant relationship exists between procrastination, delay of gratification, and job satisfaction, with work‐related stress as an intervening variable among high school teachers. The sample consisted of 150 high school teachers from Karachi, Pakistan. The analysis showed a negative correlation between procrastination and job satisfaction, and a positive correlation between delay of gratification and job satisfaction. Also, procrastination and delay of gratification were significant predictors of work‐related stress, and work‐related stress was also a significant predictor of job satisfaction. In conclusion, when the teachers are not procrastinating on their job and score high on delay of gratification they will be more satisfied with their job and feel less stressed.
Effects of emotional response on the Stroop‐like task in preschool children and young adults
Authors: Ikeda Yoshifumi , Okuzumi Hideyuki , Kokubun Mitsuru
Published: February 2014

This study investigated the effects of emotional response on an inhibitory task, the Stroop‐like day‐night task, in which participants are presented with two pictures. They are then requested to inhibit naming what the card shown to them represents and instead state what the other card represents. Specifically, 35 4‐ to 6‐year‐old children and 15 young adults were administered the emotion‐related happy‐sad task and the emotion‐unrelated up‐down task using the same stimulus set (happy and sad cartoon faces). The results suggested that vulnerability to errors in the happy‐sad task was not derived from increased inhibitory demand. The results also suggested that the happy‐sad task is more inhibitory‐demanding in terms of response time. These results suggested that the happy‐sad task elicits interference more than other variants of this task, not because the task involves emotional stimuli per se but because the task involves both emotional stimuli and emotional responses.
Latent variable models for analyzing children's processing ability
Authors: Xing Yanchun , Ma Wenqing , Shi Ningzhong , Wang Yuan
Published: February 2014

In this paper, we develop a latent processing ability model to analyze the speed of processing ability data. Our approach can not only effectively evaluate the effects of covariates on the latent processing ability, but also estimate the latent trait of each child by calculating its posterior mean. In addition, we derive the correlations structure of latent traits among different age groups. Simulations are conducted to evaluate the performance of our proposed model. The results indicated that the estimation of model parameters is satisfactory overall. The method is evaluated using real data from children aged 4–7 years inChangchun,China.
“Granny dumping”: Acceptability of sacrificing the elderly in a simulated moral dilemma
Authors: Kawai Nobuyuki , Kubo Kenta , Kubo‐Kawai Namiko
Published: February 2014

In a simulated moral dilemma, most people would be willing to endorse killing a single individual to save five others, but do people show the same degree of resistance to sacrificing people of different ages? In the present study, participants were asked to choose how acceptable it was to sacrifice one individual from a number of different age groups in order to save five others in a trolley problem. The sacrificial targets were a 70‐year‐old male stranger, a 20‐year‐old male stranger, a 5‐year‐old male stranger, or a 20‐year‐old male disabled stranger. Our results indicated that more participants accepted sacrificing the elderly stranger than the other three targets; sacrificing the child was the least accepted option. These results indicate that the decision‐making process in a moral dilemma involves weighing others' lives according to their age and implicitly predicting their life span.
Modeling of phonological encoding in spoken word production: FromGermanic languages toMandarinChinese andJapanese
Authors: Roelofs Ardi
Published: February 2014

It is widely assumed that spoken word production inGermanic languages likeDutch andEnglish involves a parallel activation of phonemic segments and metrical frames in memory, followed by a serial association of segments to the frame, as implemented in theWEAVER++ model (Levelt,Roelofs, &Meyer, 1999). However, for Oriental languages likeMandarinChinese and Japanese, researchers have suggested that the serial association concerns atonal phonological syllables (MandarinChinese) or moras (Japanese) to tonal frames. Here, the utility of these theoretical suggestions is demonstrated by computer simulations of key empirical findings using versions ofWEAVER++ forEnglish,MandarinChinese (纺 织 者++), andJapanese (). The simulation outcomes suggest that, although languages may differ in the phonological structure of their words, the principles underlying phonological encoding are similar across languages.
Sexual biofilm formation in Candida tropicalis opaque cells
Authors: Jones Stephen K. , Hirakawa Matthew P. , Bennett Richard J.
Published: February 2014

Candida albicans and Candida tropicalis are opportunistic fungal pathogens that can transition between white and opaque phenotypic states. White and opaque cells differ both morphologically and in their responses to environmental signals. In C. albicans, opaque cells respond to sexual pheromones by undergoing conjugation, while white cells are induced by pheromones to form sexual biofilms. Here, we show that sexual biofilm formation also occurs in C. tropicalis but, unlike C. albicans, biofilms are formed exclusively by opaque cells. C. tropicalis biofilm formation was dependent on the pheromone receptors Ste2 and Ste3, confirming the role of pheromone signalling in sexual biofilm development. Structural analysis of C. tropicalis sexual biofilms revealed stratified communities consisting of a basal layer of yeast cells and an upper layer of filamentous cells, together with an extracellular matrix. Transcriptional profiling showed that genes involved in pheromone signalling and conjugation were upregulated in sexual biofilms. Furthermore, FGR23, which encodes an agglutinin‐like protein, was found to enhance both mating and sexual biofilm formation. Together, these studies reveal that C. tropicalis opaque cells form sexual biofilms with a complex architecture, and suggest a conserved role for sexual agglutinins in mediating mating, cell cohesion and biofilm formation.
Phenazine redox cycling enhances anaerobic survival in Pseudomonas aeruginosa by facilitating generation of ATP and a proton‐motive force
Authors: Glasser Nathaniel R. , Kern Suzanne E. , Newman Dianne K.
Published: February 2014

While many studies have explored the growth of Pseudomonas aeruginosa, comparatively few have focused on its survival. Previously, we reported that endogenous phenazines support the anaerobic survival of P. aeruginosa, yet the physiological mechanism underpinning survival was unknown. Here, we demonstrate that phenazine redox cycling enables P. aeruginosa to oxidize glucose and pyruvate into acetate, which promotes survival by coupling acetate and ATP synthesis through the activity of acetate kinase. By measuring intracellular NAD(H) and ATP concentrations, we show that survival is correlated with ATP synthesis, which is tightly coupled to redox homeostasis during pyruvate fermentation but not during arginine fermentation. We also show that ATP hydrolysis is required to generate a proton‐motive force using the ATP synthase complex during fermentation. Together, our results suggest that phenazines enable maintenance of the proton‐motive force by promoting redox homeostasis and ATP synthesis. This work demonstrates the more general principle that extracellular redox‐active molecules, such as phenazines, can broaden the metabolic versatility of microorganisms by facilitating energy generation.
CO2 enrichment alters diurnal stem radius fluctuations of 36‐yr‐old Larix decidua growing at the alpine tree line
Authors: Dawes Melissa A. , Zweifel Roman , Dawes Nicholas , Rixen Christian , Hagedorn Frank
Published: February 2014

To understand how trees at high elevations might use water differently in the future, we investigated the effects of CO2 enrichment and soil warming (separately and combined) on the water relations of Larix decidua growing at the tree line in the Swiss Alps.

We assessed diurnal stem radius fluctuations using point dendrometers and applied a hydraulic plant model using microclimate and soil water potential data as inputs.

Trees exposed to CO2 enrichment for 9 yr showed smaller diurnal stem radius contractions (by 46 ± 16%) and expansions (42 ± 16%) compared with trees exposed to ambient CO2. Additionally, there was a delay in the timing of daily maximum (40 ± 12 min) and minimum (63 ± 14 min) radius values for trees growing under elevated CO2. Parameters optimized with the hydraulic model suggested that CO2‐enriched trees had an increased flow resistance between the xylem and bark, representing a more buffered water supply system. Soil warming did not alter diurnal fluctuation dynamics or the CO2 response.

Elevated CO2 altered the hydraulic water flow and storage system within L. decidua trees, which might have contributed to enhanced growth during 9 yr of CO2 enrichment and could ultimately influence the future competitive ability of this key tree‐line species.
Importance, but not intensity of plant interactions relates to species diversity under the interplay of stress and disturbance
Authors: Le Bagousse‐Pinguet Yoann , Maalouf Jean‐Paul , Touzard Blaise , Michalet Richard
Published: February 2014

The lack of clarity on how the intensity and importance of plant interactions change under the co‐occurrence of stress and disturbance strongly impedes assessing the relative importance of plant interactions for species diversity. We addressed this issue in subalpine grasslands of the French Pyrenees. A natural soil moisture gradient further experimentally stretched at both ends was used and a mowing disturbance treatment was applied at each position along the soil moisture gradient. Changes in intensity and importance of plant interactions were assessed by a neighbour removal experiment using four target ecotypes. A structural equation modelling approach was used to assess the relative impact of stress, disturbance, the intensity and importance of plant interactions on diversity at both the neighbourhood and community scales. Without mowing, changes in intensity and importance of plant interactions only diverged in the dry part of the soil moisture gradient. The intensity of plant interactions linearly shifted from competition to facilitation with increasing stress, while the importance followed a hump‐shaped relationship. Species diversity components were tightly related to the importance of plant interactions only, both the neighbourhood and community scales. Mowing disturbance strongly reduced the importance of facilitation along the soil moisture gradient, and suppressed the relationship between the importance of plant interactions and diversity components. Together, our results highlight that 1) the importance is the best predictor of variations in species diversity in this subalpine herbaceous system, and 2) that fine‐scale processes such as plant interactions can affect the entire plant communities. Finally, our results suggest that high level of constraints due to co‐occurring stress and disturbance can inhibit the effects of plant interactions on species diversity, highlighting their potential role in regulating diversity and the maintenance/extinction of plant communities.

Synthesis

How plant interactions change along environmental gradients is an unsolved debate, particularly when both stress and disturbance interact. This lack of clarity explains why the relative impact of plant interactions (intensity and importance) on species diversity has been rarely assessed. Using an experimental approach, we found that the importance of plant interactions highly contributed to variation in species diversity, confirming that neighbourhood scale processes such as plant interactions can affect the entire plant communities. The co‐occurrence of stress and disturbance inhibited the effects of plant interactions, highlighting that plant interactions may regulate drops of diversity and the maintenance/extinction of plant communities.
Habitat‐specific positive and negative effects of soil biota on seedling growth in a fragmented tropical montane landscape
Authors: Pizano Camila , Mangan Scott A. , Graham James H. , Kitajima Kaoru
Published: February 2014

Soil biota, in particular fungi and other microbes, are known to interactively influence plant community structure. However, soil biota effects that can be isolated in a greenhouse experiment may be overridden by other biotic and abiotic factors in the field. Here we conducted parallel greenhouse and field experiments and quantified how soil biota sampled at the habitat level affect the performance of potential host plants within and across neighboring habitat types (pastures, coffee plantations and forest fragments) in a montane region in Colombia. We hypothesized that the direction and strength of soil‐biota effects depend on the habitat where soil is sampled, focal plant's life history, and field environmental characteristics (soil nutrients, light). In a greenhouse experiment, we compared growth of 10 plant species with soil from home (where species typically occur) and foreign (where conspecific adults rarely occur) habitats, with or without soil sterilization. In the field, we conducted a reciprocal transplant experiment in which we suppressed soil fungi with the application of fungicide. In the greenhouse experiment, fast‐growing pasture grass and pioneer trees performed less well with live soil from their home, compared to foreign habitats, and such home disadvantage was reduced following soil sterilization. Home disadvantage associated with live soil biota was also detectable in the field experiment, although light conditions of grasslands and coffee plantations benefited growth of these fast‐growing species. In contrast, coffee and shade‐tolerant trees performed similarly or better with their home soils, and showed no response to soil biota suppression. Overall, the species‐and‐habitat specific soil biota effects detectable in the field experiment were similar in direction and relative strength to those from the greenhouse experiments. Our findings highlight the importance of habitat‐level plant–soil interactions and plant life history for the regeneration of natural forests and agricultural production in human‐modified landscapes.
Mapping seedling resistance to net form of net blotch (Pyrenophora teres f. teres) in barley using detached leaf assay
Authors: König Janine , Perovic Dragan , Kopahnke Doris , Ordon Frank
Published: February 2014

To develop molecular markers against Pyrenophora teres f. teres in barley, a detached leaf assay was conducted on two DH populations with a set of 11 single conidial lines (SCLs). Out of these, three showed different reactions in the DH population ‘Uschi × HHOR3073’ and two in ‘(P x V) × HHOR9484’. For SCL ‘QLB’, a 1r : 1s (χ² = 2.78) segregation was observed in the population ‘Uschi × HHOR3073’. In contrast to this, a continuous variation was observed for the SCL ‘WvB’ and ‘d8_4’ in the DH population ‘Uschi × HHOR3073’ and for ‘AR’ and ‘net1840’ in ‘(P × V) × HHOR9484’. With respect to resistance to the SCL ‘QLB’, a single major gene was located on chromosome 7H, and for resistance against SCL ‘WvB’, two QTLs were detected on chromosome 3H and 7H, and against SCL ‘d8_4’, two loci were mapped on chromosome 3HS in ‘Uschi × HHOR3073’. In the DH population ‘(P x V) × HHOR9484’, one locus conferring resistance to the SCL ‘AR’ was located on chromosome 3H. For resistance to SCL ‘net1840’, two QTLs were mapped on chromosome 4H and 5H.
Turnover time of the non‐structural carbohydrate pool influences δ18O of leaf cellulose
Authors: SONG XIN , FARQUHAR GRAHAM D. , GESSLER ARTHUR , BARBOUR MARGARET M.
Published: February 2014

Certainty regarding the degree to which organic molecules exchange oxygen with local water during plant cellulose synthesis (pex) is necessary for cellulose oxygen isotope (δ18Ocell)‐based applications in environmental and ecological studies. However, the currently accepted notion that pex is a constant of ca. 0.42 appears inconsistent with biochemical theory, which predicts that marked variation may be present in pex, in relation to variation in the turnover time (τ) of the carbohydrate pool available for cellulose synthesis. The above prediction was tested in the present study with the analysis of data collected from leaves of Ricinus communis grown in controlled environmental conditions that varied in light intensity and vapour pressure deficit. The results revealed the existence of considerable variation in both pex and τ across plants in the various growth environments. Moreover, despite uncertainties in estimates of the proportion of source water in the synthesis water (px) and of the biochemical fractionation factor (εo), our experiment yielded strong evidence that pex exhibits a significant, positive relationship with τ, consistent with biochemical theory. The observed variation in pex in association with τ has important implications for the interpretation of δ18Ocell data in environmental/ecological studies.
Assessment of the oral health condition of nursing home residents by primary care nurses
Authors: Gerritsen P.F.M. , Schrijvers A.J.P. , Cune M.S. , van der Bilt A. , de Putter C.
Published: February 2014

We interviewed 36 primary care nurses in three Dutch nursing homes regarding the functional oral health and dental treatment needs of 331 care‐dependent residents (average age 77.8 years). The nurses assessed the residents’ oral health condition as good (8.3 on a scale of 0 to 10). Edentulous residents wearing dentures were considered to have better functional oral health than dentate residents wearing partial dentures and edentulous residents not wearing dentures. According to the nurses, only 9% of the residents required dental treatment. This finding is in contrast with an intraoral study of the same population, in which dentists determined that 73% of the residents needed dental treatment.
Chlorhexidine spray as an adjunct in the control of dental biofilm in children with special needs
Authors: Viana Gilberg Resende , Teiltelbaum Ana Paula , dos Santos Fábio André , Sabbagh‐Haddad Aida , Guaré Renata Oliveira
Published: February 2014

The aim of this study was to evaluate the clinical effectiveness of .12% chlorhexidine applied via spray and the acceptance. A total of 26 individuals with mental health issues, aged 7–14, were included into two groups: placebo (control, n = 13) and chlorhexidine (experimental, n = 13). Both groups received two daily applications of spray during 2 months. The periodontal conditions were evaluated by the simplified oral hygiene index (OHI‐S) and gingival index (GI). The evaluation of acceptance of the application method (spray) was assessed by questionnaire. Data were analyzed with nonparametric tests, with a significance level of 5%. Regarding the OHI‐S index, only the experimental group showed significant change during the evaluations (p < 0.001). Regarding the GI, both groups showed significant changes during the evaluations. The method of application was well accepted by patients and caregivers, and .12% chlorhexidine solution applied via spray significantly reduced the rates of dental and gingival biofilm.
A ‘calcium capacitor’ shapes cholinergic inhibition of cochlear hair cells
Authors: Fuchs Paul Albert
Published: February 2014

Efferent cholinergic neurons project from the brainstem to inhibit sensory hair cells of the vertebrate inner ear. This inhibitory synapse combines the activity of an unusual class of ionotropic cholinergic receptor with that of nearby calcium‐dependent potassium channels to shunt and hyperpolarize the hair cell. Postsynaptic calcium signalling is constrained by a thin near‐membrane cistern that is co‐extensive with the efferent terminal contacts. The postsynaptic cistern may play an essential role in calcium homeostasis, serving as sink or source, depending on ongoing activity and the degree of buffer saturation. Release of calcium from postsynaptic stores leads to a process of retrograde facilitation via the synthesis of nitric oxide in the hair cell. Activity‐dependent synaptic modification may contribute to changes in hair cell innervation that occur during development, and in the aged or damaged cochlea.
Interfacial Strength Between Single Wall Carbon Nanotubes and Copper Material: Molecular Dynamics Simulation
Authors: Awad Ibrahim , Ladani Leila
Published: February 2014

Due to their promising mechanical and electrical properties, carbon nanotubes (CNTs) have the potential to be employed in many nano/microelectronic applications e.g., through silicon vias (TSVs), interconnects, transistors, etc. In particular, use of CNT bundles inside annular cylinders of copper (Cu) as TSV is proposed in this study. To evaluate mechanical integrity of CNT-Cu composite material, a molecular dynamics (MD) simulation of the interface between CNT and Cu is conducted. Different arrangements of single wall carbon nanotubes (SWCNTs) have been studied at interface of a Cu slab. Pullout forces have been applied to a SWCNT while Cu is spatially fixed. This study is repeated for several different cases where multiple CNT strands are interfaced with Cu slab. The results show similar behavior of the pull-out-displacement curves. After pull-out force reaches a maximum value, it oscillates around an average force with descending amplitude until the strand/s is/are completely pulled-out. A linear relationship between pull-out forces and the number of CNT strands was observed. Second order interaction effect was found to be negligible when multiple layers of CNTs were studied at the interface of Cu. C–Cu van der Waals (vdW) interaction was found to be much stronger than C–C vdW's interactions. Embedded length has no significance on the average pull-out force. However, the amplitude of oscillations increases as the length of CNTs increases. As expected when one end of CNT strand was fixed, owing to its extraordinary strength, large amount of force was required to pull it out. Finally, an analytical relationship is proposed to determine the interfacial shear strength between Cu and CNT bundle.
Self-Lubricating and Wear Resistant Epoxy Composites Incorporated With Microencapsulated Wax
Authors: Khun N. W. , Zhang H. , Yue C. Y. , Yang J. L.
Published: February 2014

Self-lubricating and wear resistant epoxy composites were developed via incorporation of wax-containing microcapsules. The effects of microcapsule size and content and working parameters on the tribological properties of epoxy composites were systematically investigated. The incorporation of microcapsules dramatically decreased the friction and wear of the composites from those of the epoxy. The increased microcapsule content or the incorporation of larger microcapsules decreased the friction and wear of the epoxy composites due to the larger amount of released wax lubricant via the rupture of microcapsules during the wear test. The friction of the composites decreased with increased normal load as a result of the promoted wear of the composites and the increased release of the wax lubricant.
Heat Transfer Measurements in Rotating Blade–Shape Serpentine Coolant Passage With Ribbed Walls at High Reynolds Numbers
Authors: Rallabandi Akhilesh , Lei Jiang , Han Je-Chin , Azad Salam , Lee Ching-Pang
Published: February 2014

Flow in the internal three-pass serpentine rib turbulated passages of an advanced high pressure rotor blade is simulated on a 1:1 scale in the laboratory. Tests to measure the effect of rotation on the Nusselt number are conducted at rotation numbers up to 0.4 and Reynolds numbers from 75,000 to 165,000. To achieve this similitude, pressurized Freon R134a vapor is utilized as the working fluid. Experimental heat transfer coefficient measurements are made using the copper-plate regional average method. Regional heat transfer coefficients are correlated with rotation numbers. An increase in heat transfer rates due to rotation is observed in radially outward passes; a reduction in heat transfer rate is observed in the radially inward pass. Strikingly, a significant deterioration in heat transfer is noticed in the “hub” region—between the radially inward second pass and the radially outward third pass. This heat transfer reduction is critical for turbine cooling designs.
Extracting Rolling Element Bearing Faults From Noisy Vibration Signal Using Kalman Filter
Authors: Khanam Sidra , Dutt J. K. , Tandon N.
Published: February 2014

Vibration analysis has been widely accepted as a common and reliable method for bearing fault identification, however, the presence of noise in the measured signal poses the maximum amount of difficulty. Therefore, for the clearer detection of defect frequencies related to bearing faults, a denoising technique based on the Kalman filtering algorithm is presented in this paper. The Kalman filter yields a linear, unbiased, and minimum mean error variance recursive algorithm to optimally estimate the unknown states of a dynamic system from noisy data taken at discrete real time intervals. The dynamics of a rotor bearing system is presented through a linear model, where displacement and velocity vectors are chosen as states of the system. Process noise and measurement noise in the equations of motion take into account the modeling inaccuracies and vibration from other sources, respectively. The covariance matrix of the process noise has been obtained through the transfer function approach. The efficiency of the proposed technique is validated through experiments. Periodic noise and random noises obeying the white Gaussian, colored Gaussian and non-Gaussian distribution have been simulated and mixed with a clean experimental signal in order to study the efficiency of the standard Kalman filter under various noisy environments. Additionally, external vibrations to the test rig have been imparted through an electromechanical shaker. The results indicate an improvement in the signal to noise ratio, resulting in the clear identification of characteristic defect frequencies after passing the signal through the Kalman filter. The authors find that there is sufficient potential in using the Kalman filter as an effective tool to denoise the bearing vibration signal.
Actuator Disk Theory—Steady and Unsteady Models
Authors: Chattot Jean-Jacques
Published: February 2014

In this paper, the classical work on steady actuator disk theory is recalled and the interpretation of the flow as the continuous shedding of vortex rings of constant strength that causes the slip stream is shown to be consistent with the classical model, yet offers a different approach that provides more flexibility for the extension to unsteady flow. The ring model is in agreement with the conservation law theorems which indicate that the axial inductance inside the streamtube, far downstream, is twice that at the rotor disk. The actuator disk relationship between the power and the axial inductance at the rotor plane has been used previously to construct the prescribed wake in the 3D vortex line model (VLM) of the author. The local pitch of the vortex sheet helices is based on the axial inductance along the streamtube, therefore, it is important to be able to calculate the axial inductance in all cases. In unsteady flow, the strength of the shed rings varies with power absorbed by the rotor and a new relationship between the two is derived to first-order, using the unsteady Bernoulli equation, which allows to calculate the inductance at the rotor and in the wake with the Biot-Savart law, even in cases where the Betz limit is exceeded. This more rigorous model can replace the semi empirical models such as dynamic stall and dynamic inflow used in the blade element method (BEM). The proposed new model has been incorporated in the VLM and applied to two sets of experiments, the Tjaereborg in-field tests and the NREL wind tunnel campaign, for which test data has been collected and serves for the comparison. The simulations show an overall good agreement with the experimental data. In some tests, the power coefficient exceeds the Betz limit, in which cases there are no solutions to the steady actuator disk theory, but the new model provides a solution for the inductance even in this case.
Active/Passive Hybrid Control System for Compressor Surge Based on Fuzzy Logic
Authors: Sheng Hanlin , Huang Wei , Zhang Tianhong , Huang Xianghua
Published: February 2014

A hybrid control system has been proposed for compressor surge, which combines the active method with the passive method. A bleed valve was selected as the actuator in the proposed system. As a submode of the hybrid system, a fuzzy logic based active controller was designed to extend the stability operating range of the compressor. Meanwhile, a surge avoidance controller was used as a backup-mode to improve the safety performance of the system. The simulation results showed that the compressor can operate steadily outside the surge line under active control mode and can be dragged back to inside the surge line by the passive control mode when the alternative fails. One advantage of the proposed control system is that it does not need a model of the compressor, and it works on any compression system. Passive surge control is a reliable and widely applied method in industrial compressors. The hybrid system makes the active control approach closer to the industrial implementation.
Synchrotron radiation imaging is a powerful tool to image brain microvasculature
Authors: Zhang Mengqi , Peng Guanyun , Sun Danni , Xie Yuanyuan , Xia Jian , Long Hongyu , Hu Kai , Xiao Bo
Published: February 2014

Synchrotron radiation (SR) imaging is a powerful experimental tool for micrometer‐scale imaging of microcirculation in vivo. This review discusses recent methodological advances and findings from morphological investigations of cerebral vascular networks during several neurovascular pathologies. In particular, it describes recent developments in SR microangiography for real‐time assessment of the brain microvasculature under various pathological conditions in small animal models. It also covers studies that employed SR‐based phase‐contrast imaging to acquire 3D brain images and provide detailed maps of brain vasculature. In addition, a brief introduction of SR technology and current limitations of SR sources are described in this review. In the near future, SR imaging could transform into a common and informative imaging modality to resolve subtle details of cerebrovascular function.
Effect of Recovery Interventions on Cycling Performance and Pacing Strategy in the Heat
Authors: De Pauw Kevin , Roelands Bart , Vanparijs Jef , Meeusen Romain
Published: February 2014

Purpose:

To determine the effect of active recovery (AR), passive rest (PR), and cold-water immersion (CWI) after 90 min of intensive cycling on a subsequent 12-min time trial (TT2) and the applied pacing strategy in TT2.

Methods:

After a maximal test and familiarization trial, 9 trained male subjects (age 22 ± 3 y, VO2max62.1 ± 5.3 mL · min−1· kg−1) performed 3 experimental trials in the heat (30°C). Each trial consisted of 2 exercise tasks separated by 1 h. The first was a 60-min constant-load trial at 55% of the maximal power output followed by a 30-min time trial (TT1). The second comprised a 12-min simulated time trial (TT2). After TT1, AR, PR, or CWI was applied for 15 min.

Results:

No significant TT2 performance differences were observed, but a 1-samplettest (within each condition) revealed different pacing strategies during TT2. CWI resulted in an even pacing strategy, while AR and PR resulted in a gradual decline of power output after the onset of TT2 (P≤ .046). During recovery, AR and CWI showed a trend toward faster blood lactate ([BLa]) removal, but during TT2 significantly higher [BLa] was only observed after CWI compared with PR (P= .011).

Conclusion:

The pacing strategy during subsequent cycling performance in the heat is influenced by the application of different postexercise recovery interventions. Although power was not significantly altered between groups, CWI enabled a differently shaped power profile, likely due to decreased thermal strain.
Yeast Osmosensors Hkr1 and Msb2 Activate the Hog1 MAPK Cascade by Different Mechanisms
Authors: Tanaka Keiichiro , Tatebayashi Kazuo , Nishimura Akiko , Yamamoto Katsuyoshi , Yang Hui-Yu , Saito Haruo
Published: February 2014

Apparent redundancy in two yeast osmosensors instead confers specificity in coupling internal and external signals.
First Report of KPC-2 Carbapenemase-Producing Klebsiella pneumoniae in Japan
Authors: Saito Ryoichi , Takahashi Rieko , Sawabe Etsuko , Koyano Saho , Takahashi Yutaka , Shima Mari , Ushizawa Hiroto , Fujie Toshihide , Tosaka Naoki , Kato Yuko , Moriya Kyoji , Tohda Shuji , Tojo Naoko , Koike Ryuji , Kubota Tetsuo
Published: February 2014

We investigated a novel Japanese isolate of sequence type 11 (ST11), the
Klebsiella pneumoniae
carbapenemase-2 (KPC-2)-producing
K. pneumoniae
strain Kp3018, which was previously obtained from a patient treated at a Brazilian hospital. This strain was resistant to various antibiotic classes, including carbapenems, and harbored the gene
bla
KPC-2
, which was present on the transferable plasmid of ca. 190 kb, in addition to the
bla
CTX-M-15
gene. Furthermore, the ca. 2.3-kb sequences (IS
Kpn8-bla
KPC-2
–IS
Kpn6
-like), encompassing
bla
KPC-2
, were found to be similar to those of
K. pneumoniae
strains from China.
The Emergence of Linezolid Resistance among Enterococci in Intestinal Microbiota of Treated Patients Is Unrelated to Individual Pharmacokinetic Characteristics
Authors: Bourgeois-Nicolaos N. , Nguyen T. T. , Defrance G. , Massias L. , Alavoine L. , Lefort A , Noel V. , Senneville E. , Doucet-Populaire F. , Mentré F. , Andremont A. , Duval X.
Published: February 2014

Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. We assessed the impact of linezolid on the microbiota and the emergence of resistance and investigated its relationship with plasma pharmacokinetics of the antibiotic. Twenty-eight patients were treated for the first time with linezolid administered orally (
n
= 17) or parenterally (
n
= 11) at 600 mg twice a day. Linezolid plasma pharmacokinetic analysis was performed on day 7. Colonization by fecal enterococci, pharyngeal streptococci, and nasal staphylococci were assessed using selective media with or without supplemental linezolid. The resistance to linezolid was characterized. The treatment led to a decrease of enterococci, staphylococci, and streptococci in the fecal (
P
= 0.03), nasal, and pharyngeal (
P
< 0.01) microbiotas. The appearance of resistant strains was observed only in enterococci from the fecal microbiota between the 7th and 21st days of treatment in four patients (14.3%). The resistance was mainly due for the first time to the mutation G2447T in the 23S rRNA gene. No pharmacokinetic parameters were significantly different between the patients, regardless of the appearance of resistance. The emergence of linezolid resistance during treatment was observed only in the intestinal microbiota and unrelated to pharmacokinetic parameters. However, colonization by Gram-positive bacteria was reduced as a result of treatment in all microbiotas.
Activity of Host Antimicrobials against Multidrug-Resistant Acinetobacter baumannii Acquiring Colistin Resistance through Loss of Lipopolysaccharide
Authors: García-Quintanilla Meritxell , Pulido Marina R. , Moreno-Martínez Patricia , Martín-Peña Reyes , López-Rojas Rafael , Pachón Jerónimo , McConnell Michael J.
Published: February 2014

Acinetobacter baumannii
can acquire resistance to the cationic peptide antibiotic colistin through complete loss of lipopolysaccharide (LPS) expression. The activities of the host cationic antimicrobials LL-37 and human lysozyme against multidrug-resistant clinical isolates of
A. baumannii
that acquired colistin resistance through lipopolysaccharide loss were characterized. We demonstrate that LL-37 has activity against strains lacking lipopolysaccharide that is similar to that of their colistin-sensitive parent strains, whereas human lysozyme has increased activity against colistin-resistant strains lacking LPS.
Neurons Are Host Cells for Mycobacterium tuberculosis
Authors: Randall Philippa J. , Hsu Nai-Jen , Lang Dirk , Cooper Susan , Sebesho Boipelo , Allie Nasiema , Keeton Roanne , Francisco Ngiambudulu M. , Salie Sumayah , Labuschagné Antoinette , Quesniaux Valerie , Ryffel Bernhard , Kellaway Lauriston , Jacobs Muazzam
Published: February 2014

Mycobacterium tuberculosisinfection of the central nervous system is thought to be initiated once the bacilli have breached the blood brain barrier and are phagocytosed, primarily by microglial cells. In this study, the interactions ofM. tuberculosiswith neuronsin vitroandin vivowere investigated. The data obtained demonstrate that neurons can act as host cells forM. tuberculosis.M. tuberculosisbacilli were internalized by murine neuronal cultured cells in a time-dependent manner after exposure, with superior uptake by HT22 cells compared to Neuro-2a cells (17.7% versus 9.8%). Internalization ofM. tuberculosisbacilli by human SK-N-SH cultured neurons suggested the clinical relevance of the findings. Moreover, primary murine hippocampus-derived neuronal cultures could similarly internalizeM. tuberculosis. InternalizedM. tuberculosisbacilli represented a productive infection with retention of bacterial viability and replicative potential, increasing 2- to 4-fold within 48 h.M. tuberculosisbacillus infection of neurons was confirmedin vivoin the brains of C57BL/6 mice after intracerebral challenge. This study, therefore, demonstrates neurons as potential new target cells forM. tuberculosiswithin the central nervous system.
Diverse Toll-Like Receptors Mediate Cytokine Production by Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans in Macrophages
Authors: Park Se-Ra , Kim Dong-Jae , Han Seung-Hyun , Kang Min-Jung , Lee Jun-Young , Jeong Yu-Jin , Lee Sang-Jin , Kim Tae-Hyoun , Ahn Sang-Gun , Yoon Jung-Hoon , Park Jong-Hwan
Published: February 2014

Toll-like receptors (TLRs) orchestrate a repertoire of immune responses in macrophages against various pathogens.Fusobacterium nucleatumandAggregatibacter actinomycetemcomitansare two important periodontal pathogens. In the present study, we investigated TLR signaling regulating cytokine production of macrophages in response toF. nucleatumandA. actinomycetemcomitans. TLR2 and TLR4 are redundant in the production of cytokines (interleukin-6 [IL-6] and tumor necrosis factor alpha [TNF-α]) inF. nucleatum- andA. actinomycetemcomitans-infected macrophages. The production of cytokines by macrophages in response toF. nucleatumandA. actinomycetemcomitansinfection was impaired in MyD88-deficient macrophages. Moreover, cytokine concentrations were lower in MyD88-deficient macrophages than in TLR2/TLR4 (TLR2/4) double-deficient cells. An endosomal TLR inhibitor, chloroquine, reduced cytokine production in TLR2/4-deficient macrophages in response toF. nucleatumandA. actinomycetemcomitans, and DNA fromF. nucleatumorA. actinomycetemcomitansinduced IL-6 production in bone marrow-derived macrophages (BMDMs), which was abolished by chloroquine. Western blot analysis revealed that TLR2/4 and MyD88 were required for optimal activation of NF-κB and mitogen-activated protein kinases (MAPKs) in macrophages in response toF. nucleatumandA. actinomycetemcomitans, with different kinetics. An inhibitor assay showed that NF-κB and all MAPKs (p38, extracellular signal-regulated kinase [ERK], and Jun N-terminal protein kinase [JNK]) mediateF. nucleatum-induced production of cytokines in macrophages, whereas NF-κB and p38, but not ERK and JNK, are involved inA. actinomycetemcomitans-mediated cytokine production. These findings suggest that multiple TLRs may participate in the cytokine production of macrophages against periodontal bacteria.
Escherichia coli Pathotypes Occupy Distinct Niches in the Mouse Intestine
Authors: Meador Jessica P. , Caldwell Matthew E. , Cohen Paul S. , Conway Tyrrell
Published: February 2014

Since the first step of the infection process is colonization of the host, it is important to understand how
Escherichia coli
pathogens successfully colonize the intestine. We previously showed that enterohemorrhagic O157:H7 strain
E. coli
EDL933 colonizes a niche in the streptomycin-treated mouse intestine that is distinct from that of human commensal strains, which explains how
E. coli
EDL933 overcomes colonization resistance imparted by some, but not all, commensal
E. coli
strains. Here we sought to determine if other
E. coli
pathogens use a similar strategy. We found that uropathogenic
E. coli
CFT073 and enteropathogenic
E. coli
E2348/69 occupy intestinal niches that are distinct from that of
E. coli
EDL933. In contrast, two enterohemorrhagic strains,
E. coli
EDL933 and
E. coli
Sakai, occupy the same niche, suggesting that strategies to prevent colonization by a given pathotype should be effective against other strains of the same pathotype. However, we found that a combination of commensal
E. coli
strains that can prevent colonization by
E. coli
EDL933 did not prevent colonization by
E. coli
CFT073 or
E. coli
E2348/69. Our results indicate that development of probiotics to target multiple
E. coli
pathotypes will be problematic, as the factors that govern niche occupation and hence stable colonization vary significantly among strains.
B-Cell Responses to Pregnancy-Restricted and -Unrestricted Plasmodium falciparum Erythrocyte Membrane Protein 1 Antigens in Ghanaian Women Naturally Exposed to Malaria Parasites
Authors: Ampomah Paulina , Stevenson Liz , Ofori Michael F. , Barfod Lea , Hviid Lars
Published: February 2014

Protective immunity toPlasmodium falciparummalaria acquired after natural exposure is largely antibody mediated. IgG-specificP. falciparumEMP1 (PfEMP1) proteins on the infected erythrocyte surface are particularly important. The transient antibody responses and the slowly acquired protective immunity probably reflect the clonal antigenic variation and allelic polymorphism of PfEMP1. However, it is likely that other immune-evasive mechanisms are also involved, such as interference with formation and maintenance of immunological memory. We measured PfEMP1-specific antibody levels by enzyme-linked immunosorbent assay (ELISA) and memory B-cell frequencies by enzyme-linked immunosorbent spot (ELISPOT) assay in a cohort ofP. falciparum-exposed nonpregnant Ghanaian women. The antigens used were a VAR2CSA-type PfEMP1 (IT4VAR04) with expression restricted to parasites infecting the placenta, as well as two commonly recognized PfEMP1 proteins (HB3VAR06 and IT4VAR60) implicated in rosetting and not pregnancy restricted. This enabled, for the first time, a direct comparison in the same individuals of immune responses specific for a clinically important parasite antigen expressed only during well-defined periods (pregnancy) to responses specific for comparable antigens expressed independent of pregnancy. Our data indicate that PfEMP1-specific B-cell memory is adequately acquired even when antigen exposure is infrequent (e.g., VAR2CSA-type PfEMP1). Furthermore, immunological memory specific for VAR2CSA-type PfEMP1 can be maintained for many years without antigen reexposure and after circulating antigen-specific IgG has disappeared. The study provides evidence that natural exposure toP. falciparumleads to formation of durable B-cell immunity to clinically important PfEMP1 antigens. This has encouraging implications for current efforts to develop PfEMP1-based vaccines.
Host Inflammatory Response Inhibits Escherichia coli O157:H7 Adhesion to Gut Epithelium through Augmentation of Mucin Expression
Authors: Xue Yansong , Zhang Hanying , Wang Hui , Hu Jia , Du Min , Zhu Mei-Jun
Published: February 2014

Escherichia coli
O157:H7, a major Shiga toxin-producing pathogen, has a low infectious dose and causes serious illness in humans. The gastrointestinal tract of cattle is the primary reservoir of
E. coli
O157:H7, and thus, it is critical to eliminate or reduce
E. coli
O157:H7 gut colonization. Given that
E. coli
O157:H7 produces effectors that attenuate inflammatory signaling, we hypothesized that the host inflammatory response acts to perturb
E. coli
O157:H7 intestinal colonization. Tumor necrosis factor alpha (TNF-α) treatment of HT-29 cells resulted in increased expression of inflammatory cytokine interleukin 1β (IL-1β), IL-8, and TNF-α genes and increased IL-8 protein and resulted in decreased adhesion of
E. coli
O157:H7. Similarly,
E. coli
O157:H7 adhesion to cattle colonic explants was reduced by TNF-α treatment. Irrespective of the presence of
E. coli
O157:H7, TNF-α enhanced activation of p65, the key mediator of NF-κB inflammatory signaling, whereas
E. coli
O157:H7 infection suppressed this pathway by inhibiting p65 activation in HT-29 cells. To further explore the mechanisms linking the inflammatory response to attenuated
E. coli
O157:H7 adhesion, mucin 2 (MUC2) expression was analyzed, considering that the intestinal mucus layer is the first defense against enteric pathogens and MUC2 is the major secretory mucin in the intestine. MUC2 expression in HT-29 cells was increased by TNF-α treatment and by
E. coli
O157:H7 infection. However, reducing mucin expression by blocking mitogen-activated protein kinase (MAPK) extracellular signal-regulated protein kinases 1/2 (ERK1/2) and/or phosphatidylinositol 3-kinase (PI3K)/Akt signaling increased
E. coli
O157:H7 adherence to HT-29 cells. These data suggest that the inflammatory cytokine response acts to protect host epithelial cells against
E. coli
O157:H7 colonization, at least in part, by promoting mucin production.