bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation efficiency of narrowband coherent thermal emitters
Authors: Gawarikar Anand S. , Shea Ryan P. , Talghader Joseph J.
Published: July 2012

The far field radiation efficiency achievable in narrowband thermal emitters is investigated, taking into account the full spatial and spectral variation of the emissivity. A coupled Fabry-Perot cavity model is used to develop an insight into the efficiency variation with cavity coherence and device temperature. It is found that the spatial variation of emissivity has to be explicitly included in the radiation power calculations to accurately estimate the achievable power efficiencies. The calculated radiation efficiencies of an ideal coherent cavity coupled emitter were found to vary from 0.1% to 9%, with a corresponding increase in the emission linewidth from 6.3 nm to 930 nm, and were much lower than that estimated without accounting for effects of spatial coherence. The analysis presented here can be used to determine the optimal operating temperature of a coherent thermal emitter once its emission characteristics and conduction losses are known and it is demonstrated that this optimum temperature is different from the temperature of peak blackbody emission at the resonant absorption wavelength.
Ab-initio calculations for a realistic sensor: A study of CO sensors based on nitrogen-rich carbon nanotubes
Authors: Souza A. M. , Rocha A. R. , Fazzio A. , da Silva A. J. R.
Published: July 2012

The use of nanoscale low-dimensional systems could boost the sensitivity of gas sensors. In this work we simulate a nanoscopic sensor based on carbon nanotubes with a large number of binding sites using ab initio density functional electronic structure calculations coupled to the Non-Equilibrium Green's Function formalism. We present a recipe where the adsorption process is studied followed by conductance calculations of a single defect system and of more realistic disordered system considering different coverages of molecules as one would expect experimentally. We found that the sensitivity of the disordered system is enhanced by a factor of 5 when compared to the single defect one. Finally, our results from the atomistic electronic transport are used as input to a simple model that connects them to experimental parameters such as temperature and partial gas pressure, providing a procedure for simulating a realistic nanoscopic gas sensor. Using this methodology we show that nitrogen-rich carbon nanotubes could work at room temperature with extremely high sensitivity.
The vacuolar Na+ - H+ antiport gene TaNHX2 confers salt tolerance on transgenic alfalfa (Medicago sativa)
Authors: Zhang Yan-Min , Liu Zi-Hui , Wen Zhi-Yu , Zhang Hong-Mei , Yang Fan , Guo Xiu-Lin
Published: July 2012

TaNHX2, a vacuolar Na+–H+ antiport gene from wheat (Triticum aestivum L.), was transformed into alfalfa (Medicago sativa L.) via Agrobacterium-mediated transformation to evaluate the role of vacuolar energy providers in plant salt stress responses. PCR and Southern blotting analysis showed that the target gene was integrated into the Medicago genome. Reverse transcription–PCR indicated that gene TaNHX2 was expressed at the transcriptional level. The relative electrical conductivity in the T2 transgenic plants was lower and the osmotic potential was higher compared to the wild-type plants under salt stress conditions. The tonoplast H+-ATPase, H+-pyrophosphatase (PPase) hydrolysis activities and ATP-dependent proton pump activities in transgenic plants were all higher than those of wild-type plants, and the enzyme activities could be induced by salt stress. The PPi-dependent proton pump activities decreased when NaCl concentrations increased from 100 mM to 200 mM, especially in transgenic plants. The vacuolar Na+–H+ antiport activities of transgenic plants were 2–3 times higher than those of the wild -type plants under 0 mM and 100 mM NaCl stress. Na+–H+ antiport activity was not detectable for wild-type plants under 200 mM NaCl, but for transgenic plants, it was further increased with an increment in salt stress intensity. These results demonstrated that expression of the foreign TaNHX2 gene enhanced salt tolerance in transgenic alfalfa.
Infrared optical actinometry to determine N- and H-atom density in a N2–H2 microwave discharge
Authors: Mavadat M , Turgeon S , Ricard A , Laroche G
Published: July 2012

Infrared (IR) emission spectroscopy was performed on N2 + H2 microwave discharges at pressures ranging between 300 and 3000 mTorr. The relative atomic density of N and H was measured by optical actinometry in the IR region at various total gas pressures. The effect of relative hydrogen partial pressure (between 10 and 90% in the discharge) on N and H relative density was also investigated. Although rarely studied, optical actinometry in the IR region has nevertheless provided numerous advantages over traditional techniques performed in the UV–visible (UV–VIS) spectral region. Results show that despite the decrease in the radiative state of the N and H atoms as a function of pressure, their ground state density increased. With increased relative hydrogen concentration under constant pressure, both the ground and the radiative state density of the H atoms increased similarly to that recorded by actinometry, whereas those of the N atoms decreased as expected. In comparing the results of the H-atom density measured in the well-documented UV–visible region and the IR region, optical actinometry confirms the accuracy of the IR method.
More and more generalists: two decades of changes in the European avifauna
Authors: Le Viol Isabelle , Jiguet Frédéric , Brotons Lluis , Herrando Sergi , Lindström Åke , Pearce-Higgins James W. , Reif Jiří , Van Turnhout Chris , Devictor Vincent
Published: July 2012

Biotic homogenization (BH) is a process whereby some species (losers) are systematically replaced by others (winners). While this process has been related to the effects of anthropogenic activities, whether and how BH is occurring across regions and the role of native species as a driver of BH has hardly been investigated. Here, we examine the trend in the community specialization index (CSI) for 234 native species of breeding birds at 10 111 sites in six European countries from 1990 to 2008. Unlike many BH studies, CSI uses abundance information to estimate the balance between generalist and specialist species in local assemblages. We show that bird communities are more and more composed of native generalist species across regions, revealing a strong, ongoing BH process. Our result suggests a rapid and non-random change in community composition at a continental scale is occurring, most likely driven by anthropogenic activities.
Do dolphins benefit from nonlinear mathematics when processing their sonar returns?
Authors: Leighton T. G. , Chua G. H. , White P. R.
Published: July 2012

Dolphins have been observed to blow bubble nets when hunting prey. Such bubble nets would confound the best man-made sonar because the strong scattering by the bubbles generates ‘clutter’ in the sonar image, which cannot be distinguished from the true target. The engineering specification of dolphin sonar is not superior to the best man-made sonar. A logical deduction from this is that, in blowing bubble nets, either dolphins are ‘blinding’ their echolocation sense when hunting or they have a facility absent in man-made sonar. Here we use nonlinear mathematical functions to process the echoes of dolphin-like pulses from targets immersed in bubble clouds. Dolphins emit sequences of clicks, and, within such a sequence, the amplitude of the clicks varies. Here such variation in amplitude between clicks is exploited to enhance sonar performance. While standard sonar processing is not able to distinguish the targets from the bubble clutter, this nonlinear processing can. Although this does not conclusively prove that dolphins do use such nonlinear processing, it demonstrates that humans can detect and classify targets in bubbly water using dolphin-like sonar pulses, raising intriguing possibilities for dolphin sonar when they make bubble nets.
Numerical Study of Models for Estimating Edge Heat Loss in Solar Absorbers
Authors: Nwosu P. N. , Onyegegbu S. O.
Published: July 2012

Absorbers are the prime heat transfer components of solar energy devices. The effects of variable edge loss coefficients on heat transfer performance of flat-plate solar absorbers are examined. From fundamental energy relations, an edge loss coefficient is obtained which embodies the geometric and ambient parameters for estimating the edge heat loss. This model is similar in form to that given by Kaligrou (2009, Solar Energy Engineering Processes and Systems, Elsevier, New York, pp. 156–163) but differs from that obtained by Duffie and Beckman (1991, Solar Engineering of Thermal Processes, Wiley & Sons, Inc., New York), which can be corrected by employing a correction factor given here. The results confirm that the edge loss can significantly affect the absorber performance depending on Ae/Ap ratios, and the prevailing ambient conditions. However, previous models neglect these effects. It is found that the model given by Duffie and Beckman erroneously exceeds the total energy input and overestimates the loss by as much as a factor of 6, which goes against the first law of thermodynamics. When the correction factor is applied, the model gives a better approximation.
An Improved Model of Asperity Interaction in Normal Contact of Rough Surfaces
Authors: Chandrasekar S. , Eriten M. , Polycarpou A. A.
Published: July 2012

Normal contact of nominally flat rough surfaces is studied with an improved analytical model of asperity interaction. A finite element model of a representative model rough surface is created, and normal contact of this model is simulated to provide a basis of validation for the developed model. The developed model is also compared to an existing model in the literature and shown to correlate better with the finite element model. Furthermore, asperity spacing (density) is shown to be an important roughness parameter in determining the effects of asperity interaction in the load-interference response of the rough contact.
The paradox of the floating candle that continues to burn
Authors: Theodorakis Stavros , Aristidou Charalambos
Published: July 2012

What happens after lighting a paraffin candle that is barely floating in water and kept upright with the aid of an appropriately weighted nail attached to its bottom? Presumably, it should sink because the buoyant force will decrease more than the weight. Surprisingly, the candle will continue to burn, rising slowly above the surface of the water. The reason for this is that the flame forms a well around the wick filled with molten paraffin, while the water keeps the outer walls of the candle cool and unscathed. Thus, the buoyancy hardly changes while the weight is reduced through burning, resulting in a floating candle that will rise above water. We present a quantitative model that describes the formation of the well and verify it experimentally, examining first the case of a candle in the air and then the case of a candle immersed in water.
Origin of the thermodynamic time arrow demonstrated in a realistic statistical system
Authors: Rȩbilas Krzysztof
Published: July 2012

This article derives and explains the emergence of one-time-direction macroscopic evolution of a classical system of two mixed gases having different temperatures. The analysis performed at the microscopic level, where the time-symmetric laws of mechanics govern the particle collisions, leads to a time-asymmetric macroscopic heat transfer equation and a theorem analogous to the Boltzmann H-theorem. The velocity distributions of the incoming and outgoing particles should satisfy some statistical symmetries. The time-reversed evolution is highly improbable because it would break these symmetries. Additionally, some remarks explaining implicit time-asymmetry of the Boltzmann Stosszahlansatz (collision number assumption) are made.
Analogy between the circular acoustic waveguide with axial temperature gradient and the electrical transmission line with source and loss
Authors: Zhao Bosen , Jebali Fathi , Francois Maurice X.
Published: July 2012

A current source introduced by an axial temperature gradient in a circular acoustic waveguide has been examined. It is shown that the effect of the axial temperature gradient is to amplify (or attenuate) the acoustic power in the waveguide where losses due to viscous effect and thermal effect are described, respectively, by a series impedance per unit length and a shunt admittance per unit length. This analogy is very useful for calculating transmissions for cases such as thermoacoustic machines, automotive mufflers, or pulse combustors. Examples of application for a thermoacoustic prime mover calculation and its experimental comparison are presented.
Harmonic alignment of impedance peaks in brass instruments
Authors: Ayers R. Dean
Published: July 2012

Given that a nearly harmonic alignment is a desirable condition, to what extent is it achieved in a particular brass instrument, and how do the bell and the input segment cooperate to bring it about? Answers to these questions that are easily read by human beings are not to be found in a plot of |Z|, or any aspect of the plane-wave reflection coefficient R at the input end of the air column. Instead, the bell and the input segment are each examined from inside the central segment and represented in terms of the effective length to a closed end, which has a simple relationship to the phase of the (internal) reflection coefficient. The sum of those two lengths should be essentially independent of frequency for harmonic alignment. This criterion is very easy to evaluate on a graph, and it applies simultaneously to all lengths of the central segment, hence all fingerings or slide positions. Minor perturbations on this relationship due to processing by the input segment and viscothermal effects on the speed of sound in the central segment will be discussed.
Overpressure reduces acceleration of thrombolysis due to ultrasound
Authors: Everbach E. Carr , White Janice , Francis Charles W.
Published: July 2012

It has been shown that application of cw ultrasound at 1–8-W/cm2 SATA intensities and megahertz frequencies can accelerate the dissolution of blood clots when a clot-lysing agent is present. To determine whether or not a cavitational mechanism is responsible for ultrasound accelerated thrombolysis (UAT), a hyperbaric chamber was constructed that can apply 10 atm of static air overpressure to an in vitro exposure apparatus. Five hundred μl fibrin clots overlaid with a clot-lysing agent were exposed to 4-W/cm2 SATA ultrasound at 1 MHz and lysis quantified via release of bound radiolabel as a function of overpressure. More than half the acceleration due to ultrasound was removed, suggesting a bubble mechanism is responsible at least in part for UAT. Transmission and reflection of 20-MHz tone bursts of 0.5 μs duration provide evidence that bubble activity was reduced concomitantly during overpressure. [Work supported by NIH.]
Wide-angle parabolic equation in moving inhomogeneous media
Authors: Ostashev V. E. , Blanc-Benon Philippe , Juvé Daniel
Published: July 2012

The wide-angle parabolic equation has been used widely to predict a sound field in an ocean with variations in the adiabatic sound speed c. The same equations with c replaced by the effective sound speed ceff=c+vx has recently been adopted for calculations of sound propagation in a stratified and/or turbulent atmosphere. Here, vx is the wind velocity component in the direction from a source to a receiver. However, as is shown in the presentation, such a replacement does not allow one to correctly take into account the effects of the medium velocity v on sound propagation and scattering in a wide-angle approximation. Furthermore, the effects of fluctuations in the density ρ on sound scattering are also omitted in this approach. In the presentation, a correct wide-angle parabolic equation in media with variations in c, ρ and v and its Padé (1,1) approximation are derived. The difference in numerical predictions of sound propagation in a stratified and turbulent atmosphere, based on the equation derived and that used previously, is demonstrated. [This material is based upon work supported in part by the U.S. Army Research Office under Contract No. DAAH04-95-1-0593.]
Detection of low-level broadband signals using adaptive matched-field processing with horizontal arrays
Authors: Booth Newell O. , Schey Phil W. , Hodgkiss W. S.
Published: July 2012

The detection performance of low spectral-level, broadband signals from a submerged acoustic source in the presence of surface interference is described and illustrated with examples obtained in the May 1996 Shallow Water evaluation cell Experiment (SWellEx-96). The experiment was carried out west of Point Loma in 200-m water of complex bathymetry. Adaptive broadband matched-field processing (MFP) was performed on a 240-m aperture horizontal line array. Detection and localization in range, depth, and azimuth is illustrated at all bearings except near the array broadside. The effects of horizontal aperture on MFP robustness and sidelobe levels are also discussed.
Paul S. Veneklasen, contributions to architectural acoustical design, 1960–1996
Authors: Christoff Jerry P. , Good James A.
Published: July 2012

Paul Veneklasen will be remembered most for his contributions to architectural acoustics, especially completed, highly acclaimed auditoriums, ranging from the Seattle Opera House and Los Angeles Music Center to Wolf Trap Farm Park to name a few. But he also left a legacy of hundreds of radio, television, and recording studios, and virtually every other building type from office buildings to convention centers and even jet engine test cells and noise suppressors. But less known are his development of orchestra enclosures, pit lifts, multilayer gypsum board construction, damped glass panels, floating floors, and sound doors incorporating magnetic seals and acoustical filters. His research extended from optimizing sight lines and seating arrangements in auditoriums, acoustical modeling, and theater chairs. Highlights of Paul Veneklasen’s well-known projects, developments, and research are presented.
Effects of high-intensity focused ultrasound on H22 liver tumor: An evaluation with different therapeutic programs
Authors: Wu Feng , Wang Zhi B. , Wang Zhi L.
Published: July 2012

Most research shows that high-intensity focused ultrasound (HIFU) offers an extracorporeal approach to local removal of tumors. In order to choose the optimal conditions for clinical trials, this study was to evaluate the effects of different therapeutic programs of HIFU with 1200 W/cm2 on H22 liver tumors. Seventy-three ICR tumor-bearing mice were divided into a control group and HIFU therapeutic groups. The therapy programs were defined by the numbers of pulses and pulse durations of HIFU with a 1.6-MHz focused transducer. The various parameters of tumor growth, x-ray, histology, electron microscopy, and mice nutritional state were used to assess the results of HIFU treatment. The data showed that HIFU had an inhibitory effect on H22 tumor growth in all therapeutic groups. With the same input power, the local effects of tumor removal were dependent upon the pulse durations and numbers of pulse. When the total number of pulses increased within a short time, the inhibitory effect was stronger. However, the nutritional state of animals in this group became worse. It implies that severe stress response and catabolism induced by an increase of HIFU pulse in a short time would occur.
The energy analysis of the piezoceramic bodies under nonuniform deformations
Authors: Aronov Boris , Brown David A.
Published: July 2012

One of the most powerful and clear methods of solving electromechanical transducer problems is an energy method based on the use of Lagrange equations. To apply this method to piezoceramic transducers one needs to have an expression for internal energy of a piezoceramic body in a convenient form. Such a general expression for energy under arbitrary nonuniform deformations is developed and discussed. It is shown that under certain conditions the electrical and mechanical variables in the expression for internal energy of a piezoceramic body can be separated. The underlying physics for this condition is illustrated with an example of piezoceramic rods with transverse and axial polarization. In the case of electrical and mechanical variables that are not separated, the contribution of mutual terms in the total internal energy is expressed analytically and can be easily treated.
Restricted Gene Flow among Hospital Subpopulations of Enterococcus faecium
Authors: Willems Rob J. L. , Top Janetta , van Schaik Willem , Leavis Helen , Bonten Marc , Sirén Jukka , Hanage William P. , Corander Jukka
Published: July 2012

Enterococcus faecium
has recently emerged as an important multiresistant nosocomial pathogen. Defining population structure in this species is required to provide insight into the existence, distribution, and dynamics of specific multiresistant or pathogenic lineages in particular environments, like the hospital. Here, we probe the population structure of
E. faecium
using Bayesian-based population genetic modeling implemented in Bayesian Analysis of Population Structure (BAPS) software. The analysis involved 1,720 isolates belonging to 519 sequence types (STs) (491 for
E. faecium
and 28 for
Enterococcus faecalis
).
E. faecium
isolates grouped into 13 BAPS (sub)groups, but the large majority (80%) of nosocomial isolates clustered in two subgroups (2-1 and 3-3). Phylogenetic and eBURST analysis of BAPS groups 2 and 3 confirmed the existence of three separate hospital lineages (17, 18, and 78), highlighting different evolutionary trajectories for BAPS 2-1 (lineage 78) and 3-3 (lineage 17 and lineage 18) isolates. Phylogenomic analysis of 29
E. faecium
isolates showed agreement between BAPS assignment of STs and their relative positions in the phylogenetic tree. Odds ratio calculation confirmed the significant association between hospital isolates with BAPS 3-3 and lineages 17, 18, and 78. Admixture analysis showed a scarce number of recombination events between the different BAPS groups. For the
E. faecium
hospital population, we propose an evolutionary model in which strains with a high propensity to colonize and infect hospitalized patients arise through horizontal gene transfer. Once adapted to the distinct hospital niche, this subpopulation becomes isolated, and recombination with other populations declines.

IMPORTANCE
Multiresistant
Enterococcus faecium
has become one of the most important nosocomial pathogens, causing increasing numbers of nosocomial infections worldwide. Here, we used Bayesian population genetic analysis to identify groups of related
E. faecium
strains and show a significant association of hospital and farm animal isolates to different genetic groups. We also found that hospital isolates could be divided into three lineages originating from sequence types (STs) 17, 18, and 78. We propose that, driven by the selective pressure in hospitals, the three hospital lineages have arisen through horizontal gene transfer, but once adapted to the distinct pathogenic niche, this population has become isolated and recombination with other populations declines. Elucidation of the population structure is a prerequisite for effective control of multiresistant
E. faecium
since it provides insight into the processes that have led to the progressive change of
E. faecium
from an innocent commensal to a multiresistant hospital-adapted pathogen.
Maternal note-taking and infant care: a pilot randomised controlled trial
Authors: Kistin Caroline J , Barrero-Castillero Alejandra , Lewis Sheilajane , Hoch Rachel , Philipp Barbara L , Bauchner Howard , Wang C Jason
Published: July 2012

Design

A pilot randomised controlled trial was conducted with postpartum mothers to assess the feasibility and impact of note-taking during newborn teaching. Controls received standard teaching; the intervention group received pen and paper to take notes. Subjects were called 2 days post-discharge to assess infant sleep position, breastfeeding, car seat use, satisfaction and information recall.

Results

126 mothers were randomised. There was a consistent trend that intervention subjects were more likely to report infant supine sleep position (88% vs 78%, relative risks (RR) 1.13; 95% CI 0.95 to 1.34), breastfeeding (96% vs 86%, RR 1.11; 95% CI 0.99 to 1.25) and correct car seat use (98% vs 87%, RR 1.12; 95% CI 1.00 to 1.25). Satisfaction and information recall did not differ. Among first-time mothers, intervention subjects were significantly more likely to report infant supine sleep position (95% vs 65%, RR 1.46; 95% CI 1.06 to 2.00).

Conclusions

Maternal note-taking is feasible and potentially efficacious in promoting desirable infant care.
The Relationship between Tuberculosis and Influenza Death during the Influenza (H1N1) Pandemic from 1918-19
Authors: Oei Welling , Nishiura Hiroshi
Published: July 2012

The epidemiological mechanisms behind the W-shaped age-specific influenza mortality during the Spanish influenza (H1N1) pandemic 1918-19 have yet to be fully clarified. The present study aimed to develop a formal hypothesis: tuberculosis (TB) was associated with the W-shaped influenza mortality from 1918-19. Three pieces of epidemiological information were assessed: (i) the epidemic records containing the age-specific numbers of cases and deaths of influenza from 1918-19, (ii) an outbreak record of influenza in a Swiss TB sanatorium during the pandemic, and (iii) the age-dependent TB mortality over time in the early 20th century. Analyzing the data (i), we found that the W-shaped pattern was not only seen in mortality but also in the age-specific case fatality ratio, suggesting the presence of underlying age-specific risk factor(s) of influenza death among young adults. From the data (ii), TB was shown to be associated with influenza death (P=0.09), and there was no influenza death among non-TB controls. The data (iii) were analyzed by employing the age-period-cohort model, revealing harvesting effect in the period function of TB mortality shortly after the 1918-19 pandemic. These findings suggest that it is worthwhile to further explore the role of TB in characterizing the age-specific risk of influenza death.
Targeted Antibiotic Prophylaxis for Lung Transplantation in Cystic Fibrosis Patients Colonised withPseudomonas aeruginosaUsing Multiple Combination Bactericidal Testing
Authors: Haja Mydin Helmy , Corris Paul A. , Nicholson Audrey , Perry John D. , Meachery Gerard , Marrs Emma C. L. , Peart Steven , Fagan Christine , Lordan James L. , Fisher Andrew J. , Gould Frances K.
Published: July 2012

Early infection is a recognised complication after lung transplantation in patients with cystic fibrosis (CF). Our centre uses multiple combination bactericidal testing (MCBT) when determining appropriate peritransplant prophylactic regimens. To evaluate our strategy, we compared the incidence of posttransplant infection in patients whose peritransplant antimicrobial regimens were determined using MCBT versus standard sensitivity testing. Patients with CF who were infected withPseudomonas aeruginosaand underwent lung transplantations between 2000 and 2010 were included. Data was collected from clinical records and our microbiology database. Microorganisms cultured were mapped against antibiotic resistance, method of sensitivity testing, and antibiotics administered peritransplant. 129 patients were identified (mean age 28, male : female, 63 : 66). Fifty patients (38.8%) had antibiotics determined by MCBT. Two patients in the MCBT group developed septicaemia, 13 in the conventional group (P≤0.05, 2-tailed Fisher's test). Sepsis was attributable toP. aeruginosain one patient from the MCBT group and seven patients in the conventional group (P=0.15).P. aeruginosawas recovered from the posttransplant pleural fluid of one patient who received MCBT-guided prophylaxis, six patients in the conventional group (P=0.25). Patients given antibiotics based on MCBT had significantly lower rates of septicaemia and lower rates of empyema.
Erythromelalgia: An Uncommon Presentation Precipitated by Aspirin Withdrawal
Authors: Khalid Fatima , Hassan Syed , Qureshi Sophia , Qureshi Waqas , Amer Syed
Published: July 2012

Erythromelalgia is a rare disorder frequently associated with myeloproliferative disorders. We describe a case of elderly patient diagnosed with myeloproliferative disorder in remission. The patient was on aspirin for secondary prevention of stroke and was taken off aspirin and developed erythromelalgia within two weeks of withdrawal of aspirin. After restarting aspirin, patient’s symptoms improved within 2 weeks.
Unphosphorylated STAT1 Promotes Sarcoma Development through Repressing Expression of Fas and Bad and Conferring Apoptotic Resistance
Authors: Zimmerman Mary A. , Rahman Nur-Taz , Yang Dafeng , Lahat Guy , Lazar Alexander J. , Pollock Raphael E. , Lev Dina , Liu Kebin
Published: July 2012

STAT1 exists in phosphorylated (pSTAT1) and unphosphorylated (uSTAT1) forms each regulated by IFN-γ. Although STAT1 is a key mediator of the IFN-γ signaling pathway, an essential component of the host cancer immunosurveillance system, STAT1 is also overexpressed in certain human cancers where the functions of pSTAT1 and uSTAT1 are ill defined. Using a murine model of soft tissue sarcoma (STS), we show that disruption of the IFN effector molecule IRF8 decreases pSTAT1 and increases uSTAT1 in STS cells, thereby increasing their metastatic potential. We determined that the IRF8 gene promoter was hypermethylated frequently in human STS. An analysis of 123 human STS specimens revealed that high uSTAT1 levels in tumor cells was correlated with a reduction in disease-specific survival (DSS), whereas high pSTAT1 levels in tumor cells were correlated with an increase in DSS. In addition, uSTAT1 levels were negatively correlated with pSTAT1 levels in these STS specimens. Mechanistic investigations revealed that IRF8 suppressed STAT1 transcription by binding the STAT1 promoter. RNAi-mediated silencing of STAT1 in STS cells was sufficient to increase expression of the apoptotic mediators Fas and Bad and to elevate the sensitivity of STS cells to Fas-mediated apoptosis. Together, our findings show how the phosphorylation status of pSTAT1 determines its function as a tumor suppressor, with uSTAT1 acting as a tumor promoter that acts by elevating resistance to Fas-mediated apoptosis to promote immune escape. Cancer Res; 72(18); 4724–32. ©2012 AACR.
Clinical Trial Results with the MED-EL Fine Structure Processing Coding Strategy in Experienced Cochlear Implant Users
Authors: Müller Joachim , Brill Stefan , Hagen Rudolf , Moeltner Alexander , Brockmeier Steffi-Johanna , Stark Thomas , Helbig Silke , Maurer Jan , Zahnert Thomas , Zierhofer Clemens , Nopp Peter , Anderson Ilona
Published: July 2012

Objectives: To assess the subjective and objective performance of the new fine structure processing strategy (FSP) compared to the previous generation coding strategies CIS+ and HDCIS. Methods: Forty-six adults with a minimum of 6 months of cochlear implant experience were included. CIS+, HDCIS and FSP were compared in speech perception tests in noise, pitch scaling and questionnaires. The randomized tests were performed acutely (interval 1) and again after 3 months of FSP experience (interval 3). The subjective evaluation included questionnaire 1 at intervals 1 and 3, and questionnaire 2 at interval 2, 1 month after interval 1. Results: Comparison between FSP and CIS+ showed that FSP performed at least as well as CIS+ in all speech perception tests, and outperformed CIS+ in vowel and monosyllabic word discrimination. Comparison between FSP and HDCIS showed that both performed equally well in all speech perception tests. Pitch scaling showed that FSP performed at least as well as HDCIS. With FSP, sound quality was at least as good and often better than with HDCIS. Conclusions: Results indicate that FSP performs better than CIS+ in vowel and monosyllabic word understanding. Subjective evaluation demonstrates strong user preferences for FSP when listening to speech and music.
Modelling and Prediction of 25-Hydroxyvitamin D Levels in Norwegian Relapsing-Remitting Multiple Sclerosis Patients
Authors: Šaltytė Benth J. , Myhr K.-M. , Løken-Amsrud K.I. , Beiske A.G. , Bjerve K.S. , Hovdal H. , Midgard R. , Holmøy T.
Published: July 2012

Background/Aim: 25-Hydroxyvitamin D (25(OH)D) levels are suggested to influence the susceptibility and risk of disease progression in multiple sclerosis (MS). Seasonal fluctuation of 25(OH)D levels may differ in magnitude between individuals. The purpose of this paper was to model the seasonal fluctuation of vitamin D in Norwegian MS patients and to examine to which extent one single 25(OH)D measurement predicts the level at other time points throughout the year. Methods: During December 2004 and July 2008, 762 serum samples were collected from 92 Norwegian relapsing-remitting MS patients. Time series analysis and multivariate modelling techniques were used to model seasonal fluctuations and intra- and inter-individual variations in 25(OH)D values. Results: Most patients reached their lowest 25(OH)D level in March/April and the highest in July/August. There were substantial intra-individual variations in the extent of seasonal fluctuation, with 36.6% of explainable variation in seasonally adjusted 25(OH)D levels (on a logarithmic scale) attributable to the patient level. The remaining 63.4% could be accounted for by sources of inter-individual variation. Both the total and inter-individual variabilities were lowest in February, and the prediction interval in this month was up to 26% narrower compared to other months. The prediction intervals would be at least 21% wider with only one observation available per patient. Conclusions: The seasonal fluctuations of 25(OH)D levels in Norwegian relapsing-remitting MS patients are subject to pronounced intra- and inter-individual variation. The most representative measurements of 25(OH)D levels are taken in February.
Oculopalpebral Dimensions of Adult Nigerians: Report from the Enugu Normative Ocular Anthropometry Study
Authors: Eze Boniface I. , Uche Judith N. , Shiweobi Jude O. , Mba Chibuike N.
Published: July 2012

Objective: To determine the normal oculopalpebral anthropometric measurements of a Nigerian adult population. Subjects andMethods: A population-based prospective observational random survey was conducted in Enugu, South-Eastern Nigeria between January and April 2010. The participants were healthy adults comprising 248 males and 252 females aged 18–76 years. One thousand eyes were examined. Demographic data, and bilateral direct manual millimetre measurements of the horizontal palpebral fissure (HPF), vertical palpebral fissure (VPF), upper lid crease (ULC), brow height (BH), and margin reflex distance (MRD) were obtained from all participants. Data were categorised by demographic variables and analysed to yield frequencies, percentages and proportions. Between-gender comparisons, using the independent t test, were considered significant at p < 0.05. Results: The mean age of the participants was 36.5 ± 14.6 years. There was no significant difference between the genders in mean age (men: 37.3 ± 15.7 vs. women: 35.8 ± 13.3, p = 0.2302). The mean values of the parameters were (male, female) HPF: 32.8 ± 2.0 vs. 32.6 ± 3.0; VPF: 10.6 ± 1.2 vs. 10.6 ± 1.2; ULC: 8.2 ± 2.5 vs. 7.9 ± 2.2; BH: 13.1 ± 2.4 vs. 13.6 ± 2.7; and MRD: 4.1 ± 0.5 vs. 4.2 ± 0.8. Significant between-gender difference was observed only in BH measurements (p = 0.029) and variable trends with age. Conclusion: Oculopalpebral measurements of normal adult Nigerians in Enugu showed variations by age and gender. This may have implications for clinical evaluation and surgical management of oculopalpebral disorders in adult South-Eastern Nigerians. Future longitudinal studies are needed.
Relationship between Changes in Plasma Adiponectin Concentration and Insulin Sensitivity after Niacin Therapy
Authors: Fraterrigo Gemma , Fabbrini Elisa , Mittendorfer Bettina , O’Rahilly Stephen , Scherer Philipp E. , Patterson Bruce W. , Klein Samuel
Published: July 2012

Background: Niaspan® (extended-release niacin) is a nicotinic acid formulation used to treat dyslipidemia in obese subjects. Niaspan binds to the GPR109A receptor in adipose tissue and stimulates adiponectin secretion, which should improve insulin sensitivity. However, Niaspan therapy often causes insulin resistance. The purpose of this study was to evaluate whether Niaspan-induced changes in plasma adiponectin concentration are associated with a blunting of Niaspan’s adverse effect on insulin action in obese subjects with non-alcoholic fatty liver disease (NAFLD). Methods: A hyperinsulinemic-euglycemic clamp procedure was used to assess muscle insulin sensitivity before and after 16 weeks of Niaspan therapy in 9 obese subjects with NAFLD [age 43 ± 5 years; BMI 35.1 ± 1.3 (means ± SEM)]. Results: Niaspan therapy did not affect body weight (99.1 ± 4.2 vs. 100 ± 4.4 kg) or percent body fat (37.8 ± 2.5 vs. 37.0 ± 2.5%). However, Niaspan therapy caused a 22% reduction in insulin-mediated glucose disposal (p < 0.05). The deterioration in glucose disposal was inversely correlated with the Niaspan-induced increase in plasma adiponectin concentration (r = 0.67, p = 0.05). Conclusions: These results demonstrate that Niaspan causes skeletal muscle insulin resistance, independent of changes in body weight or body fat, and the Niaspan-induced increase in plasma adiponectin concentration might partially ameliorate Niaspan’s adverse effect on insulin action in obese subjects with NAFLD.
Freeze the Stroke
Authors: Tedim Cruz Vítor , Araújo Isabel , Alves Ivânia , Magano Aldiro , Coutinho Paula
Published: July 2012

Background and Purpose—

The capacity of the general population to identify stroke signs is a major determinant for success of prehospital emergency pathways. Previous educational strategies using the media were usually short-lived and expensive. Tailoring information programs for special subgroups like acute stroke relatives may improve this situation.

Methods—

A poster was assembled that included a list of stroke signs and instructions to call 911. Consecutive admissions to the stroke unit were randomized. Intervention consisted of an educational session with relatives, in which a nurse delivered 5 posters and asked for their placement on the freezer door at the kitchen of the patient's house and each of 4 neighboring houses. One month later, a questionnaire was administered to both groups.

Results—

Sixty admissions were randomized (30 interventions), and 150 posters were distributed. One month after discharge, response rates were 81% for intervention group and 48% for control group. In the intervention arm, 64.5% had all the 4 answers correct, and 74.2% identified all first signs of stroke. For the control group, these values were 8% and 20%, respectively (
P
<0.001).

Conclusions—

This stroke unit–based information strategy improved awareness of relatives and neighbors when compared with the usual discharge plan. The program avoids the media and explores regional health care structure and family and social organizations, and it targets a subgroup keen to receive and spread information. The low cost, ease of use, and duration of the stimulus facilitate further testing and evaluation of impact on hospital presentation and thrombolytic treatment rates.
The Effects of Usury Laws: Evidence from the Online Loan Market
Authors: Rigbi Oren
Published: July 2012

Usury laws cap the interest rates that lenders can charge. Using data from Prosper.com, an online lending marketplace, I investigate the effects of these laws. The key to my empirical strategy is that there was initially substantial variability in states' interest rate caps, ranging from 6% to 36%. A behind-the-scenes change in loan origination, however, suddenly increased the cap to 36%. The main findings of the study are that higher interest rate caps increase the probability that a loan will be funded, especially if the borrower was previously just "outside the money." I do not find, however, changes in loan amounts and default probability. The interest rate paid rises slightly, probably because online lending is substantially, yet imperfectly, integrated with the general credit market.
Import Competition and Skill Content in U.S. Manufacturing Industries
Authors: Lu Yi , Ng Travis
Published: July 2012

Skill content varies enormously across industries and over time. This paper shows that import competition can explain a significant portion of the variation in various skill measures across manufacturing industries. Industries that face more intense import competition employ more nonroutine skill sets, including cognitive, interpersonal, and manual skills, and fewer cognitive routine skills. In addition, we find that the impact of import competition on skills is not driven by imports from low-wage countries or from China. A number of robustness checks also suggest that our results are unlikely to be driven by econometric problems.
An Application of Sequential Variational Method without Tangent Linear and Adjoint Model Integrations
Authors: Dobricic Srdjan
Published: July 2012

The sequential variational (SVAR) method minimizes the weakly constrained four-dimensional cost function by splitting it into a set of smaller cost functions. This study shows how it is possible to apply SVAR in practice by reducing the computational effort required by the algorithm. A major finding of the study is that, instead of using tangent linear and adjoint models, it is possible to estimate the largest eigenvalues and the corresponding eigenvectors of the evolution of the background error covariances only by applying successive nonlinear model integrations. Another major finding is that the impact of future observations on previous state estimates may be obtained in an accurate and numerically stable way by using suitably defined cost functions and control space transformations without any additional model integrations. The new method is applied in a realistic data assimilation experiment with a primitive equations ocean model.
Juvenile Nasopharyngeal Angiofibroma
Authors: Cloutier Tam , Pons Yoann , Blancal Jean‐Philippe , Sauvaget Elisabeth , Kania Romain , Bresson Damien , Herman Philippe
Published: July 2012

Objective

The aim of this study was to review recent management of juvenile nasopharyngeal angiofibroma (JNA) in our institution during the past 10 years and to analyze the shift in surgical paradigm based on the rate of endoscopic approach and Radkowski staging.

Study Design

Case series with chart review.

Setting

The study was conducted from April 2000 to August 2010 in a tertiary care university hospital (Lariboisière, Paris, France).

Subjects and Methods

All patients referred for a JNA were included in the study. Medical files and imaging data were retrospectively analyzed. Surgical management was then evaluated for 2 different periods (group 1, n = 31, consecutive patients operated on from April 2000 to June 2005, and group 2, n = 41, from July 2005 to August 2010).

Results

Seventy‐two patients were operated on, with a mean age of 16.25 years (range, 9‐33 years). The rate of the endoscopic approach was significantly higher in group 2 than in group 1 (82.9% vs 45%). Rates of recurrence and complications were similar. Recurrences (ie, residual disease growing and treated by redo) were noted in 6 cases or 8.3% (group 1, n = 3; group 2, n = 3; P >. 05).

Conclusion

Progress in skull base anatomy, instrumentation, cameras, and surgical strategy allows for expansion of the indications for endoscopic removal of JNA. This approach may have a better outcome in terms of blood loss, hospital stay, and local sequelae. Still, an external approach should be considered only for selected cases due to massive intracranial extension or optic nerve or internal carotid artery entrapment by the tumor.
Effect of hydration on the structures and properties of poly(p-phenylene benzobisoxazole)/poly(pyridobisimidazole) block copolymer fibers
Authors: Cao Kai-Kai , Zhong Yu-Jia , Guan Guo-Hu , Li Chun-Cheng , Zhu Wen-Xiang , Xiao Yao-Nan , Zhang Dong , Zheng Liu-Chun
Published: July 2012

A rigid-rod copolymer, poly( p-phenylene benzobisoxazole)-block-poly(pyridobisimidazole) (PBO-b-PIPD), was synthesized, and the effect of hydration on the structures and performance of the block copolymer fibers was evaluated. PBO and PBO-b-PIPD as-spun fibers (AS-fibers) were prepared by dry-jet wet spinning, and subsequent thermal treatment in a nitrogen atmosphere was performed. Fourier transform infrared and wide-angle X-ray diffraction were used to characterize the structures of the thermally treated fibers. Mechanical properties of both the AS-fibers and thermally treated fibers were tested, and scanning electronic microscopy was used to observe the fracture surfaces of the fibers from tensile testing. It has been revealed that heat treatment is an effective method to remove the absorbed water to improve the orderly arrangement of chains along the fiber direction, which resulted in enhancement of the tensile modulus of the block copolymer fibers.
A three-stacked patch antenna using high-dielectric ceramic material substrate
Authors: Ullah Mohammad H , Islam Mohammad T , Jit Mandeep S , Misran Norbahiah
Published: July 2012

The design and analysis of a new three-stacked patch antenna on aluminum oxide ceramic material substrate are presented in this article. Using high-dielectric material substrate, the overall size of the antenna is appreciably reduced without compromising the performance result of the antenna. The proposed antenna is designed and studied using commercially available finite element method–based high-frequency electromagnetic solver from ANSYS Corporation. From the result, it is observed that in the operating frequency range from 16.20 to 19.31 GHz (voltage standing wave ratio < 2), a wide range of bandwidth of 3.09 GHz and gain of 7.05 dBi at a resonant frequency of 17.20 GHz is achieved. It is also found that at the entire operating frequency band, the average gain is 3.5 dBi and the radiation efficiency is from 84% to 89%. The proposed antenna is fit for part of Ku-band and Ka-band applications.
Promoting Early Intervention Referral Through a Randomized Controlled Home-Visiting Program
Authors: Schwarz Donald F. , O’Sullivan Ann L. , Guinn Judith , Mautone Jennifer A. , Carlson Elyse C. , Zhao Huaqing , Zhang Xuemei , Esposito Tara L. , Askew Megan , Radcliffe Jerilynn
Published: July 2012

The MOM Program is a randomized, controlled trial of an intervention to promote mothers’ care for the health and development of their children, including accessing early intervention (EI) services. Study aims were to determine whether, relative to controls, this intervention increased receipt of and referral to EI services. Mothers ( N = 302) living in high-poverty regions were recruited after having given birth to healthy infants and were randomized to the intervention ( n = 152) or control ( n = 150) group. Those in the intervention group received up to 11 home visits to promote well-child visits and referral to EI. Children in the intervention group were referred to and received EI services significantly more often than those in the control group. Maternal depression and age of the mother were significantly associated with referral to, and receipt of, EI.