bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying Equilibria Shifts due to Externalities
Authors: Corrigan Kiara , Shah Amip J.
Published: March 2012

As environmental sustainability becomes increasingly integrated into the mainstream values, previously ignored externalities may be expected to enter into the economic valuation process. This is already evident, as an illustration, in the price that several entities are beginning to attach to carbon (with examples including cap-and-trade, carbon taxes, etc). In this paper, we present a basic economic partial equilibrium model to evaluate such externalities within the context of a particular industry. We begin by discussing how economic values may be attached to different externalities, and focus our analysis on carbon as an example of an environmental impact which may need to get internalized within the cost structure of a given organization. With such a new cost structure in place, we use historical estimates of the elasticity of supply and demand within a given industry to evaluate how the costs may propagate up and down the value chain. For example, how much of the costs are likely to get absorbed internally within a supply chain? What fraction of costs might a manufacturer reasonably expect to pass along to downstream consumers? With such estimates in place, we then predict using microeconomic theory how the supply-demand equilibrium within a particular market may shift. We discuss how such a simple approach to evaluating externalities may be used to simulate the effects of different policy choices, and illustrate the approach through an example case study of the electric utility industry. We conclude with a discussion of future work that seeks to expand considerations beyond the electric utility industry and methods to extend this simplified modeling framework.
A New Modeling Approach to Forecast Building Energy Demands During Extreme Heat Events in Complex Cities
Authors: Gutie´rrez Estatio , Gonza´lez Jorge E. , Bornstein Robert , Arend Mark , Martilli Alberto
Published: March 2012

The thermal response of a large city including the energy production aspects of it are explored for a large and complex city using urbanized atmospheric mesoscale modeling. The Weather Research and Forecasting (WRF) mesocale model is coupled to a multi-layer urban canopy model that considers thermal and mechanical effects of the urban environment including a building scale energy model to account for anthropogenic heat contributions due to indoor-outdoor temperature differences. This new urban parameterization is used to evaluate the evolution and the resulting urban heat island formation associated to a 3-day heat wave in New York City (NYC) during the summer of 2010. High resolution (250 m.) urban canopy parameters (UCPs) from the National Urban Database were employed to initialize the multi-layer urban parameterization. The precision of the numerical simulations is evaluated using a range of observations. Data from a dense network of surface weather stations, wind profilers and Lidar measurements are compared to model outputs over Manhattan and its surroundings during the 3-days event. The thermal and drag effects of buildings represented in the multilayer urban canopy model improves simulations over urban regions giving better estimates of the surface temperature and wind speed. An accurate representation of the nocturnal urban heat island registered over NYC in the event was obtained from the improved model. The accuracy of the simulation is further assessed against more simplified urban parameterizations models with positive results with new approach. Results are further used to quantify the energy consumption of the buildings during the heat wave, and to explore alternatives to mitigate the intensity of the UHI during the extreme event.
Test Results of a Combined Storage System for Parabolic Trough Power Plants With Direct Steam Generation
Authors: Laing Doerte , Eickhoff Martin , Fiß Michael , Hempel Matthias , Meyer-Gru¨nefeldt Mirko , Bahl Carsten
Published: March 2012

For future parabolic trough plants direct steam generation in the absorber pipes is a promising option for reducing the costs of solar thermal energy. These new solar thermal power plants require innovative storage concepts, where the two phase heat transfer fluid poses a major challenge. A three-part storage system is proposed for the two phase fluid water/steam. Concrete storage is used for the process steps involving transfer of sensible heat — i.e. preheating of water and superheating of steam — while for the two-phase evaporation a phase change material (PCM) storage will be deployed. This technology is currently developed by DLR and Ed. Zu¨blin AG within the project ITES, funded partly by the German Ministry for the Environment, Nature Conservation and Nuclear Safety. A combined storage solution with a 22 m3 concrete storage test module for superheating of steam and a 8.5 m3 PCM-storage for evaporation of water was build in 2009 in a direct steam test loop, set up at the power plant Litoral of Endesa in Carboneras, Spain. This high temperature storage system has a total capacity of approx. 1000 kWh and it will be the first demonstration of such a combined storage system for the two phase heat transfer fluid water/steam. Commissioning was completed in 2010, implying first heating-up of the concrete storage to expel the excess water in the concrete, first heating-up of the PCM storage including final filling of the storage with salt. Cycling tests for each storage unit separately are in progress. Combined testing will start in 2011. Results on the commissioning and testing will be reported in the paper.
The Design Analysis of a Water Sourced District Heating and Cooling System for a Neighborhood Development Project
Authors: Yin Hongxi , Cai Yuefeng , Lv Hengxing , Qu Ming , Ao Guowei , Li Nianping
Published: March 2012

On the basis of the principles of Green Infrastructure and Building (GIB) in LEED for Green Neighborhood Development (LEED-ND), this paper studies the technical feasibility, economic soundness, and environmental effectiveness of a water-sourced energy system in a 6.5 million square feet mixed-use neighborhood development project in Changsha, Hunan Province, China. Two energy systems proposed for the project are compared in the study by using scientific fundamentals and engineering principle. The two energy systems are: • System One: Use Xiangjiang River as cooling water for absorption chillers to generate chilled water for all buildings. • System Two: Use traditional cooling towers providing cooling water for absorption chillers to generate chilled water for all buildings. The system performance analyses of study show that system one has better energy, environmental and economic performance than system two. Compared to system two, system one is predicted to have a saving of 32% in electricity, 11% in natural gas, and 675 ton/year in CO2 emission; and its system payback year is 8 years. This paper also investigated the impact of system one on the Xiangjiang River by using Fluent computational fluid dynamics (CFD). The results of the CFD simulation indicated that there no significant changes of river temperature over time.. Finally, some suggestions on design and operation have been provided for system one to be implemented.
Cumulative Frequency Distributions for Hourly Global Illuminance
Authors: Satyamurty V. V. , RaviKumar P.
Published: March 2012

In the present article, cumulative frequency distributions for hourly global horizontal illuminance based on the modeled data of 56 US locations have been presented. Measured illuminance information from other sources also has been utilized. Suitable normalized variables have been introduced to depict the generalized cumulative frequency distributions for hourly global illuminance. The cumulative distributions developed based on representative set locations have been shown to be applicable for another set of locations. In addition, the present article brings out, the major differences between daily and hourly cumulative frequency distributions and, a method to generate hourly (synthetic) global illuminance data from the frequency distributions.
Thermal and Mechanical Characterization of Contiguous Wall Systems for Energy Efficient Low Cost Housing
Authors: Mobasher Barzin , Minor Geoffrey , Zenouzi Mansour , Jalife Salvador L.
Published: March 2012

The interaction of alternative technologies for low cost housing using a fully integrated finite element thermal and structural model of the system. The such as matrix formulations, or different wall systems can be accomplished using. Multi-layer systems based on composite laminate theory are used as a substitution for both reinforcement and effective thermal barrier of structural walls and roof systems. Textile Reinforced Cement composites (TRCs) as thin sandwich skin elements are considered since they show improved tension capacity and ductility based a well-bonded and well-distributed reinforcement that minimizes the flaw sizes, leading to the increase in overall strength and ductility. A range of innovative materials are used in a transient thermal analysis of the composite wall system. Using both 2-D and 3-D finite element analysis, field data obtained from interior and exterior faces of three model construction systems are simulated for walls and roof members as a function of time. Using the exterior temperature as the imposed boundary condition, the interior temperatures were predicted and compared with the experimentally obtained results. Sensitivity of the model to changes in parameters is studied for various insulating materials.
Influence of process parameters on rolling-contact-fatigue life of ion plated nickel–copper–silver lubrication
Authors: Danyluk Mike , Dhingra Anoop
Published: March 2012

In this paper, we present a connection between argon ion flux, element-mixing, and rolling contact fatigue (RCF) life of a thin film nickel–copper–silver lubricant on ball bearings. The film is deposited on the balls using an ion plating process and tested for RCF in high vacuum. The ion flux is measured using a Langmuir probe and the plane stress within the film during deposition is calculated using a thin film model. Experiments reveal that there is an inverse relationship between ion flux and RCF life for most deposition voltage and pressure combinations tested, specifically, 15.5–18.5 mTorr and 1.5–3.5 kV. For voltages up to 2.5 kV, RCF life decreases as ion flux increases due to increased compressive stress within the film, reaching as high as 2.6 GPa. For voltages between 2.5 and 3.5 kV, interlayer mixing of nickel and copper with the silver layer reduces RCF life due to contamination, even as ion flux and corresponding film compressive stress are reduced. A Monte Carlo-based simulation tool, SRIM™ is used to track collision cascades of the argon ions and metal atoms within the coating layers. At process voltages above 2.5 kV we observe elemental mixing of copper and nickel with the silver layer using Auger electron spectroscopy of coated steel and Si3N4 balls. The authors conclude that an ion flux greater than 5.0 × 1014 cm−2 s−1 leads to reduced RCF life due to high film stress. In addition, process voltages greater than 2.5 kV also reduce RCF life due to contamination and interlayer mixing of nickel and copper within the silver layer.
Classroom measurements of sound speed in fresh/saline water
Authors: Carman Jessie C.
Published: March 2012

A tabletop apparatus permitting demonstrations and hands-on student exercises in the measurement of sound speed in water as a function of both temperature and salinity, at atmospheric pressure, is described. By measuring sound speed using a differential technique with a precisely measured path length difference Δx, errors due to uncertainty in original path length are minimized. The apparatus can be used to measure sound speed in freshwater baths of varying temperature and room temperature baths of varying salinities to provide the student a clear picture of sound speed variation along two axes.
A simple and inexpensive optical technique to help students visualize mode shapes
Authors: Moore Thomas R. , Cannaday Ashley E. , Zietlow Sarah A.
Published: March 2012

An imaging technique is introduced that is suitable for visualizing the mode shapes of vibrating structures in an educational setting. The method produces images similar to those obtained using electronic speckle pattern interferometry (ESPI), but it can be implemented for less than 1/10 the cost of a commercial ESPI system, and the apparatus is simple enough that it can be constructed by undergraduate students. This technique allows for real-time visualization of the normal modes and deflection shapes of harmonically vibrating structures, including those with shapes that make generating Chladni patterns with sand or powder impossible. The theory of operation and construction details are discussed.
How can humans, in air, hear sound generated underwater (and can goldfish hear their owners talking)?
Authors: Leighton T. G.
Published: March 2012

The air/water interface at the top of a body of water is often treated from below as a pressure release boundary, which it closely matches. The small discrepancy in that match, however, is enough to enable humans in air to hear sounds generated underwater, which would not be possible across a pressure release boundary. A discussion of this phenomenon, designed for teaching purposes and using no more acoustics than would be contained in a first-year undergraduate syllabus in acoustics, leads to a discussion of whether goldfish can hear their owners speaking. The analysis is then used to illustrate the care needed when comparing sound levels in air and water, a process which continues to lead to erroneous statements in the media and some academic articles.
Normal modes of the Indian elephant bell
Authors: Perrin Robert , Chalmers Luke , Elford Daniel P. , Swallowe Gerry M. , Moore Thomas R.
Published: March 2012

The geometrical structure of the Indian elephant bell is presented and the requirements on its normal modes from group representation theory are described. These are in good agreement with the results of a finite-element model (FEM) for a specific 16-tine case. The spectrum consists of a sequence of families of modes lying on saturation curves, completely different from those of conventional bells. Physical explanations for the occurrence of these families are presented in terms of the tines behaving as a closed loop of coupled cantilevers with constraints from the dome. Each family is found to consist of modes in one of two specific sequences of symmetry types. Experimental measurements of the modes of this same 16-tine bell, using electronic speckle pattern interferometry (ESPI), have been made and are compared with the FEM predictions. Although the interpretation of the interferograms is difficult in all but the simpler cases, agreement in terms of frequencies is surprisingly good for the first few family sequences. The ESPI study also showed up numerous harmonics and subharmonics of true normal modes, showing the system to be rather non-linear and making comparisons with the FEM results tricky.
Modeling three-dimensional propagation in a continental shelf environment
Authors: Ballard Megan S.
Published: March 2012

An acoustic propagation model is applied to predict measurements of three-dimensional (3-D) effects recorded off the southeast coast of Florida. The measured signal is produced by a low frequency source that is towed north parallel to the shelf from a fixed receiving array. The acoustic data show the direct path arrival at the bearing of the tow ship and a second refracted path arrival as much as 30° inshore of the direct arrival. Notably, the refracted arrival has a received level more than 25 dB greater than that of the direct arrival. A geoacoustic model of the environment is created to explain the data. It is shown that the topography of the seafloor plays the largest role in controlling horizontal refraction effects, whereas the range-dependent sediment properties have the most influence on the received level. The modeling approach is based on a 3-D adiabatic mode technique in which the horizontal refraction equation is solved using a parabolic equation in Cartesian coordinates. A modal decomposition of the field provides insight into the variability in the arrival angle and received level of the measured signal.
The effect of dissipation on the resistive admittance of an elastic medium
Authors: Photiadis Douglas M.
Published: March 2012

The effect of dissipation on the real part of the admittance of an elastic half-space is typically thought to be unimportant if the loss factor ζ of the elastic medium is small. However, dissipation induces losses in the near field of the source and, provided the size of the source is small enough, this phenomenon can be more important than elastic wave radiation. Such losses give rise to a fundamental limit in the quality factor of an oscillator attached to a substrate. Near field losses associated with strains in the elastic substrate can actually be larger than intrinsic losses in the oscillator itself if the internal friction of the substrate is larger than the internal friction of the oscillator. For a uniform stress applied to a disk of radius a, a monopole source, such phenomena become significant for kLa<ζ, while for higher order multipole sources of order l, near field losses are important for (kLa)l+1<ζ, a far less restrictive constraint.
On the study of the effects of sea views, greenery views and personal characteristics on noise annoyance perception at homes
Authors: Nang Li Hak , Kwan Chau Chi , Sze Tse Man , Tang Shiu Keung
Published: March 2012

Noise annoyance has caused significant adverse impacts on human beings and numerous efforts have been spent on mitigating annoyance problems. Natural greenery has been shown to be able to moderate annoyance problems at home but this conclusion was drawn without properly controlling the potential confounding factors. Furthermore, few have explored the moderation effect of a sea view. Accordingly, this study formulated a multivariate model to examine the impacts of natural views as well as personal characteristics on annoyance perception. A housing estate was selected in Hong Kong as the survey site for which some of the residents were exposed to greenery views, sea views, or both from their homes. Eight hundred and sixty-one responses were collected via questionnaire surveys and analyzed using an ordered logit model. The results suggest that both a greenery view and a sea view can moderate annoyance responses. Several individual’s personal characteristics are found to affect individuals’ annoyance perception. The duration of time spent daily at home is shown to have an influence on the moderation impact exerted by a greenery view, while the age of an individual is shown to have an influence on noise moderation effect exerted by a sea view.
Excitation mechanisms and dispersion characteristics of guided waves in multilayered cylindrical solid media
Authors: Cui Hanyin , Zhang Bixing , Johnstone Sherri , Trevelyan Jon
Published: March 2012

This paper first reviews a method of simulating the propagation characteristics of guided waves in multilayered coaxial cylindrical elastic solid media. Secondly, this method is used to investigate the properties of the guided waves for the ultrasonic long-range non-destructive evaluation techniques for rockbolts. To do so, the special case of non-leaky guided modes in open waveguides is considered. The method explains how the complex dispersion function is converted into a real function: hence the bisection technique can be employed to search for all the real roots. The model is used to (i) characterize the low dispersion range and anomalous dispersion of normal and Stoneley modes and (ii) analyze the excitation mechanisms of guided waves from axisymmetric and non-axisymmetric acoustic sources. The results are used to select suitable excitation frequency ranges associated with dominant modes with large amplitudes, low dispersion, and distinguishable propagation velocities to reduce signal distortion. The results suggest the lowest order flexural mode, excited by a radial force source, has potential to be used in practice. Also, the highly dispersive Stoneley mode propagating along a cylindrical interface is defined and distinguished from the normal mode using two properties, velocity high-frequency asymptotes and amplitude distributions along the radial direction.
Product directivity models for parametric loudspeakers
Authors: Shi Chuang , Gan Woon-Seng
Published: March 2012

In a recent work, the beamsteering characteristics of parametric loudspeakers were validated in an experiment. It was shown that based on the product directivity model, the locations and amplitudes of the mainlobe and grating lobes could be predicted within acceptable errors. However, the measured amplitudes of sidelobes have not been able to match the theoretical results accurately. In this paper, the original theories behind the product directivity model are revisited, and three modified product directivity models are proposed: (i) the advanced product directivity model, (ii) the exponential product directivity model, and (iii) the combined product directivity model. The proposed product directivity models take the radii of equivalent Gaussian sources into account and obtain better predictions of sidelobes for the difference frequency waves. From the comparison between measurement results and numerical solutions, all the proposed models outperform the original product directivity model in terms of selected sidelobe predictions by about 10 dB.
Evaluating acoustic speaker normalization algorithms: Evidence from longitudinal child data
Authors: Kohn Mary Elizabeth , Farrington Charlie
Published: March 2012

Speaker vowel formant normalization, a technique that controls for variation introduced by physical differences between speakers, is necessary in variationist studies to compare speakers of different ages, genders, and physiological makeup in order to understand non-physiological variation patterns within populations. Many algorithms have been established to reduce variation introduced into vocalic data from physiological sources. The lack of real-time studies tracking the effectiveness of these normalization algorithms from childhood through adolescence inhibits exploration of child participation in vowel shifts. This analysis compares normalization techniques applied to data collected from ten African American children across five time points. Linear regressions compare the reduction in variation attributable to age and gender for each speaker for the vowels BEET, BAT, BOT, BUT, and BOAR. A normalization technique is successful if it maintains variation attributable to a reference sociolinguistic variable, while reducing variation attributable to age. Results indicate that normalization techniques which rely on both a measure of central tendency and range of the vowel space perform best at reducing variation attributable to age, although some variation attributable to age persists after normalization for some sections of the vowel space.
Shear waves in viscoelastic wormlike micellar fluids over a broad concentration range
Authors: Gladden J. R. , Gamble A. M. , Skelton C. E. , Mobley J.
Published: March 2012

Low frequency (61 Hz) shear wave speeds have been measured in viscoelastic wormlike micellar (WM) fluids for a concentration range of 20/12-500/300 mM CTAB/NaSAL where CTAB is the surfactant and NaSAL is the salt and the concentration ratio was fixed at 0.6 for all experiments. The birefringent property of the WM fluids was exploited to visually track the the shear pulse using crossed optical polarizing filters and high speed video. Several scalings of shear wave speed as a function of concentration were discovered: cs ∼ C for 20–200 mM and cs ∼ C for higher concentrations, but with a break in the slope at 400 mM CTAB. Over this full concentration range, the shear wave speed varied from 0.08–0.7 m/s. The shear wave speed was also found to be sensitive to the time between fluid synthesis and measurement indicating a long equilibrium time. Further, comparison with elastic and loss moduli obtained from rheology data show that shear wave propagation is dominated by the elastic modulus for this frequency range. Also briefly discussed are potential applications of this fluid in elastography.
Characterization of circumferential guided waves in a cylindrical cortical bone-mimicking phantom
Authors: Nauleau Pierre , Cochard Etienne , Minonzio Jean-Gabriel , Grimal Quentin , Laugier Pascal , Prada Claire
Published: March 2012

The femoral neck cortical shell was recently demonstrated to act like a waveguide for circumferential waves. Femoral neck assessment with ultrasound could be enhanced by guided waves measurement. In this study, the decomposition of the time reversal operator (DORT) method is used to measure the phase velocities of circumferential guided modes in a circular tube with dimensions characteristic of femoral neck. The tube is made of a bone-mimicking material. Five guided modes are obtained and compared to theoretical predictions. The work substantiates the feasibility of measuring guided waves in a relatively thick tube of attenuating material with the DORT method.
High-frequency modulated signals of killer whales (Orcinus orca) in the North Pacific
Authors: Simonis Anne E. , Baumann-Pickering Simone , Oleson Erin , Melcón Mariana L. , Gassmann Martin , Wiggins Sean M. , Hildebrand John A.
Published: March 2012

Killer whales in the North Pacific, similar to Atlantic populations, produce high-frequency modulated signals, based on acoustic recordings from ship-based hydrophone arrays and autonomous recorders at multiple locations. The median peak frequency of these signals ranged from 19.6–36.1 kHz and median duration ranged from 50–163 ms. Source levels were 185–193 dB peak-to-peak re: 1 μPa at 1 m. These uniform, repetitive, down-swept signals are similar to bat echolocation signals and possibly could have echolocation functionality. A large geographic range of occurrence suggests that different killer whale ecotypes may utilize these signals.
Comment on “Widespread RNA and DNA Sequence Differences in the Human Transcriptome”
Authors: Lin Wei , Piskol Robert , Tan Meng How , Li Jin Billy
Published: March 2012

Li
et al
. (Research Articles, 1 July 2011, p. 53; published online 19 May 2011) reported widespread differences between the RNA and DNA sequences of the same human cells, including all 12 possible mismatch types. Before accepting such a fundamental claim, a deeper analysis of the sequencing data is required to discern true differences between RNA and DNA from potential artifacts.
Sexual Deprivation Increases Ethanol Intake in
Drosophila
Authors: Shohat-Ophir G. , Kaun K. R. , Azanchi R. , Mohammed H. , Heberlein U.
Published: March 2012

Toward Addiction

Addiction can result when substances, such as drugs or alcohol, co-opt the brain's natural reward system.

Shohat-Ophir
et al.

(p.
1351
; see the Perspective by

Zars

) explored this potential in
Drosophila
by examining the relationship between the natural reward stimulated by mating and the unnatural reward offered by ethanol consumption. Males deprived of mating increased consumption of ethanol, and, when permitted to mate following deprivation, their ethanol consumption decreased. At a mechanistic level, mating increased the neurotransmitter neuropeptide F (NPF), while mate deprivation decreased NPF levels.
Climatic Niche Shifts Are Rare Among Terrestrial Plant Invaders
Authors: Petitpierre Blaise , Kueffer Christoph , Broennimann Olivier , Randin Christophe , Daehler Curtis , Guisan Antoine
Published: March 2012

Invading a Place Like Home

Biological invasions can cause enormous economic problems but they also represent a biological experiment and provide insight into species distributions and range expansion or restriction. Most predictions about when and where species will invade rest on the assumption that invasive species will retain the same climatic niche in the invaded area. But is this assumption valid?

Petitpierre
et al.

(p.
1344
) studied a large data set on plant invasions between Eurasia, North America, and Australia and indeed found that fewer than 15% of the studied species occupied more than 10% of invaded distribution outside their native climatic niche, and only one species exhibited >50% climatic niche expansion in its invaded range. Thus, niche shifts are rather rare events in plant invasions.
Stunningly Successful Solutions
Nine Algorithms That Changed the Future
The Ingenious Ideas That Drive Today's Computers

by John MacCormick

Princeton University Press, Princeton, NJ, 2012. 231 pp. $27.95, £19.95. ISBN 9780691147147.
Authors: Curzon Paul
Published: March 2012

Writing for nonspecialists, MacCormick explains a selection of complex algorithms that we rely on daily for tasks such as determining the importance of Web pages.
She Said No, Pass Me a Beer
Authors: Zars Troy
Published: March 2012

Sexual rejection or deprivation is connected to ethanol consumption in
Drosophila
.
Key Neutrino Measurement Signals China's Rise
Authors: Cho Adrian
Published: March 2012

On 8 March, physicists working with China's Daya Bay Reactor Neutrino Experiment announced the measurement of a crucial parameter describing the behavior of neutrinos.
Trends and Characteristics of Culture-Confirmed Staphylococcus aureus Infections in a Large U.S. Integrated Health Care Organization
Authors: Ray G. Thomas , Suaya Jose A. , Baxter Roger
Published: March 2012

Infections due to
Staphylococcus aureus
present a significant health problem in the United States. Between 1990 and 2005, there was a dramatic increase in community-associated methicillin-resistant
S. aureus
(MRSA), but recent reports suggest that MRSA may be declining. We retrospectively identified
S. aureus
isolates (
n
= 133,450) that were obtained from patients in a large integrated health plan between 1 January 1998 and 31 December 2009. Trends over time in MRSA were analyzed, and demographic risk factors for MRSA versus methicillin-susceptible
S. aureus
(MSSA) were identified. The percentage of
S. aureus
isolates that were MRSA increased from 9% to 20% between 1998 and 2001 and from 25% to 49% between 2002 and 2005 and decreased from 49% to 43% between 2006 and 2009. The increase in MRSA was seen in blood and in other bacteriological specimens and occurred in all age and race/ethnicity groups, though it was most pronounced in persons aged 18 to <50 years and African-Americans. Hospital onset infections were the most likely to be MRSA (odds ratio [OR], 1.58; confidence interval [CI], 1.46 to 1.70, compared to community-associated cases), but the largest increase in MRSA was in community-associated infections. Isolates from African-Americans (OR, 1.73; CI, 1.64 to 1.82) and Hispanics (OR, 1.11; CI, 1.06 to 1.16) were more likely to be MRSA than those from whites. After substantial increases between 1998 and 2005 in the proportion of
S. aureus
isolates that were MRSA, the proportion decreased between 2006 and 2009. Hospital onset
S. aureus
infections are disproportionately MRSA, as are those among African-Americans.
Comparison of Seven Tests for High-Grade Cervical Intraepithelial Neoplasia in Women with Abnormal Smears: the Predictors 2 Study
Authors: Szarewski Anne , Mesher David , Cadman Louise , Austin Janet , Ashdown-Barr Lesley , Ho Linda , Terry George , Liddle Stuart , Young Martin , Stoler Mark , McCarthy Julie , Wright Corrina , Bergeron Christine , Soutter W. P , Lyons Deirdre , Cuzick Jack
Published: March 2012

High-risk human papillomavirus (HPV) DNA/RNA testing provides higher sensitivity but lower specificity than cytology for the identification of high-grade cervical intraepithelial neoplasia (CIN). Several new HPV tests are now available for this purpose, and a direct comparison of their properties is needed. Seven tests were evaluated with samples in liquid PreservCyt transport medium from 1,099 women referred for colposcopy: the Hybrid Capture 2 (Qiagen), Cobas (Roche), PreTect HPV-Proofer (NorChip), Aptima HPV (Gen-Probe), and Abbott RealTi
m
e assays, the BD HPV test, and CINtec p16
INK4a
cytology (mtm laboratories) immunocytochemistry. Sensitivity, specificity, and positive predictive value (PPV) were based on the worst histology found on either the biopsy or the treatment specimen after central review. Three hundred fifty-nine women (32.7%) had CIN grade 2+ (CIN2+), with 224 (20.4%) having CIN3+. For detection of CIN2+, Hybrid Capture 2 had 96.3% sensitivity, 19.5% specificity, and 37.4% PPV. Cobas had 95.2% sensitivity, 24.0% specificity, and 37.6% PPV. The BD HPV test had 95.0% sensitivity, 24.2% specificity, and 37.8% PPV. Abbott RealTi
m
e had 93.3% sensitivity, 27.3% specificity, and 38.2% PPV. Aptima had 95.3% sensitivity, 28.8% specificity, and 39.3% PPV. PreTect HPV-Proofer had 74.1% sensitivity, 70.8% specificity, and 55.4% PPV. CINtec p16
INK4a
cytology had 85.7% sensitivity, 54.7% specificity, and 49.1% PPV. Cytology of a specimen taken at colposcopy (mild dyskaryosis or worse) had 88.9% sensitivity, 58.1% specificity, and 50.7% PPV. Our study confirms that, in a referral setting, HPV testing by a number of different tests provides high sensitivity for high-grade disease. Further work is needed to confirm these findings in a routine screening setting.
Frequency of Microbiologically Correct Antibiotic Therapy Increased by Infectious Disease Consultations and Microbiological Results
Authors: Kerremans J. J. , Verbrugh H. A. , Vos M. C.
Published: March 2012

In a prospective observational study of bacteremic patients we ascertained the influence of different parts of culture results on the correctness of empirical antibiotic therapy. Ninety-three bacteremic patients requiring antibiotic treatment were included. Patients who had consultations with an infectious disease consultation service before they became bacteremic received microbiologically correct empirical antibiotic therapy more often than those who did not have such consultations (75% versus 53%;
P
= 0.03). As a direct result of Gram staining, 92% of all patients received microbiologically correct antibiotic therapy.
Simultaneous Identification of 29 Prevalent Invasive Pneumococcal Serotypes or Pairs of Serotypes by Hybridization-Ligation PCR
Authors: Ortega Doménech Montserrat , Tarragó Asensio David
Published: March 2012

A hybridization-ligation PCR assay was developed for the simultaneous detection and identification of 21 pneumococcal serotypes and 8 pairs of serotypes in the same serogroup: 1, 2, 3, 4, 5, 6A, 6B, 6C-6D, 7F-7A, 8, 9A-9V, 9N-9L, 11A, 14, 15B-15C, 16F, 17F, 18B-18C, 19A, 19F, 20, 21, 22A-22F, 23A, 23B, 23F, 28A-28F, 35B and 38. This novel assay was validated with 185 serotyped pneumococcal invasive clinical isolates and 57 culture-negative pleural fluids previously typed by real-time PCR.
ON THE "LSND ANOMALY"
Authors: DEDOVICH DMITRY , ZHEMCHUGOV ALEXEY
Published: March 2012

In the LSND experiment at the Los Alamos National Laboratory, a larger than expected [Formula: see text] signal was observed and interpreted as evidence of the oscillation [Formula: see text] with Δm2 in the range of 0.2–10 eV2. Since such a Δm2 range is incompatible with the widely accepted model of oscillations between three light neutrino species, and since there was no confirmation from other neutrino experiments, this finding became known as the "LSND anomaly". If true, it would require the existence of at least one "sterile" neutrino which calls the Standard Model of particle physics in a nontrivial way into question. This review discusses the current status of the "LSND anomaly", including the prospects of further experimental checks.
USING A VARIABLE WEIGHTING k-MEANS METHOD TO BUILD A DECISION CLUSTER CLASSIFICATION MODEL
Authors: LI YAN , HUNG EDWARD , CHUNG KORRIS , HUANG JOSHUA
Published: March 2012

In this paper, a new classification method (ADCC) for high-dimensional data is proposed. In this method, a decision cluster classification (DCC) model consists of a set of disjoint decision clusters, each labeled with a dominant class that determines the class of new objects falling in the cluster. A cluster tree is first generated from a training data set by recursively calling a variable weighting k-means algorithm. Then, the DCC model is extracted from the tree. Various tests including Anderson–Darling test are used to determine the stopping condition of the tree growing. A series of experiments on both synthetic and real data sets have been conducted. Their results show that the new classification method (ADCC) performed better in accuracy and scalability than existing methods like k-NN, decision tree and SVM. ADCC is particularly suitable for large, high-dimensional data with many classes.
IRIS RECOGNITION USING ADABOOST AND LEVENSHTEIN DISTANCES
Authors: CLIMENT JOAN , HEXSEL ROBERTO A.
Published: March 2012

This paper presents an efficient IrisCode classifier, built from phase features which uses AdaBoost for the selection of Gabor wavelets bandwidths. The final iris classifier consists of a weighted contribution of weak classifiers. As weak classifiers we use three-split decision trees that identify a candidate based on the Levenshtein distance between phase vectors of the respective iris images. Our experiments show that the Levenshtein distance has better discrimination in comparing IrisCodes than the Hamming distance. Our process also differs from existing methods because the wavelengths of the Gabor filters used, and their final weights in the decision function, are chosen from the robust final classifier, instead of being fixed and/or limited by the programmer, thus yielding higher iris recognition rates. A pyramidal strategy for cascading filters with increasing complexity makes the system suitable for real-time operation. We have designed a processor array to accelerate the computation of the Levenshtein distance. The processing elements are simple basic cells, interconnected by relatively short paths, which makes it suitable for a VLSI implementation.
The Group of Dyadic Unitary Matrices
Authors: De Vos Alexis , Van Laer Raphaël , Vandenbrande Steven
Published: March 2012

We introduce the group DU (m) of m × m dyadic unitary matrices, i.e. unitary matrices with all entries having a real and an imaginary part that are both rational numbers with denominator of the form 2p(with p a non-negative integer). We investigate in detail the finite groups DU(1) and DU(2) and the discrete, but infinite groups DU(3) and DU(4). We further introduce the subgroup XDU (m) of DU (m), consisting of those members of DU (m) that have constant line sum 1. The study of XDU(2) and XDU(4) leads to conclusions concerning the synthesis of quantum computers acting on one and two qubits, respectively.
Circulant States with Vanishing Quantum Discord
Authors: Bylicka Bogna , Chruściński Dariusz
Published: March 2012

We analyze a class of 2-qudit circulant states. They define a generalization of well-known 2-qubit X-states. We formulate necessary and sufficient criteria for vanishing of quantum discord. We illustrate our analysis by an important subclass of circulant states — the so-called Bell diagonal states.
Process Dimension of Classical and Non-Commutative Processes
Authors: Löhr Wolfgang , Szkoła Arleta , Ay Nihat
Published: March 2012

We treat observable operator models (OOM) and their non-commutative generalisation, which we call NC-OOMs. A natural characteristic of a stochastic process in the context of classical OOM theory is the process dimension. We investigate its properties within the more general formulation, which allows one to consider process dimension as a measure of complexity of non-commutative processes: We prove lower semi-continuity, and derive an ergodic decomposition formula. Further, we obtain results on the close relationship between the canonical OOM and the concept of causal states which underlies the definition of statistical complexity. In particular, the topological statistical complexity, i.e. the logarithm of the number of causal states, turns out to be an upper bound to the logarithm of process dimension.
Gating of connexin 43 gap junctions by a cytoplasmic loop calmodulin binding domain
Authors: Xu Qin , Kopp Richard F. , Chen Yanyi , Yang Jenny J. , Roe Michael W. , Veenstra Richard D.
Published: March 2012

Calmodulin (CaM) binding sites were recently identified on the cytoplasmic loop (CL) of at least three α-subfamily connexins (Cx43, Cx44, Cx50), while Cx40 does not have this putative CaM binding domain. The purpose of this study was to examine the functional relevance of the putative Cx43 CaM binding site on the Ca2+-dependent regulation of gap junction proteins formed by Cx43 and Cx40. Dual whole cell patch-clamp experiments were performed on stable murine Neuro-2a cells expressing Cx43 or Cx40. Addition of ionomycin to increase external Ca2+ influx reduced Cx43 gap junction conductance (Gj) by 95%, while increasing cytosolic Ca2+ concentration threefold. By contrast, Cx40 Gj declined by <20%. The Ca2+-induced decline in Cx43 Gj was prevented by pretreatment with calmidazolium or reversed by the addition of 10 mM EGTA to Ca2+-free extracellular solution, if Ca2+ chelation was commenced before complete uncoupling, after which gj was only 60% recoverable. The Cx43 CL136–158 mimetic peptide, but not the scrambled control peptide, or Ca2+/CaM-dependent kinase II 290–309 inhibitory peptide also prevented the Ca2+/CaM-dependent decline of Cx43 Gj. Cx43 gap junction channel open probability decreased to zero without reductions in the current amplitudes during external Ca2+/ionomycin perfusion. We conclude that Cx43 gap junctions are gated closed by a Ca2+/CaM-dependent mechanism involving the carboxyl-terminal quarter of the connexin CL domain. This study provides the first evidence of intrinsic differences in the Ca2+ regulatory properties of Cx43 and Cx40.
Motion clouds: model-based stimulus synthesis of natural-like random textures for the study of motion perception
Authors: Leon Paula Sanz , Vanzetta Ivo , Masson Guillaume S. , Perrinet Laurent U.
Published: March 2012

Choosing an appropriate set of stimuli is essential to characterize the response of a sensory system to a particular functional dimension, such as the eye movement following the motion of a visual scene. Here, we describe a framework to generate random texture movies with controlled information content, i.e., Motion Clouds. These stimuli are defined using a generative model that is based on controlled experimental parametrization. We show that Motion Clouds correspond to dense mixing of localized moving gratings with random positions. Their global envelope is similar to natural-like stimulation with an approximate full-field translation corresponding to a retinal slip. We describe the construction of these stimuli mathematically and propose an open-source Python-based implementation. Examples of the use of this framework are shown. We also propose extensions to other modalities such as color vision, touch, and audition.
Changes in interhemispheric inhibition from active to resting primary motor cortex during a fine-motor manipulation task
Authors: Morishita Takuya , Uehara Kazumasa , Funase Kozo
Published: March 2012

The effect of performance of a sensorimotor task on the interhemispheric inhibition (IHI) induced from the active primary motor cortex (M1) to the resting M1 was examined in 10 right-handed subjects. Transcranial magnetic stimulation (TMS) was performed to produce motor evoked potentials (MEP) in the resting right (Rt)-first dorsal interosseous (FDI). For the paired-TMS paradigm, a conditioning stimulus (CS) was delivered to the Rt-M1, and its intensity was adjusted from 0.6 to 1.4 times the resting motor threshold of the MEP in the left (Lt)-FDI in 0.2 steps. The test stimulus was delivered to the Lt-M1, and its intensity was adjusted to evoke similar MEP amplitudes in the Rt-FDI among the task conditions. The interstimulus interval was fixed at 10 ms. As a sensorimotor task, a fine-motor manipulation (FM) task (using chopsticks to pick up, transport, and release glass balls) was adopted. In addition, an isometric abduction (IA) task was also performed as a control task. These tasks were carried out with the left hand. The IHI from the active to the resting M1 observed during the FM task was markedly increased compared with that induced during the IA task, and this effect was not dependent on the MEP amplitude evoked in the active Lt-FDI by the CS. The present findings suggest that the increased IHI from the active to the resting M1 observed during the FM task was linked to reductions in the activity of the ipsilateral intracortical inhibitory circuit, as we reported previously.
Boron Particle Ignition in Secondary Chamber of Ducted Rocket
Authors: Hu J. X. , Xia Z. X. , Zhang W. H. , Fang Z. B. , Wang D. Q. , Huang L. Y.
Published: March 2012

In the secondary chamber of ducted rocket, there exists a relative speed between boron particles and air stream. Hence, the ignition laws under static conditions cannot be simply applied to represent the actual ignition process of boron particles, and it is required to study the effect of forced convective on the ignition of boron particles. Preheating of boron particles in gas generator makes it possible to utilize the velocity difference between gas and particles in secondary chamber for removal of the liquid oxide layer with the aid of Stoke's forces. An ignition model of boron particles is formulated for the oxide layer removal by considering that it results from a boundary layer stripping mechanism. The shearing action exerted by the high-speed flow causes a boundary layer to be formed in the surface of the liquid oxide layer, and the stripping away of this layer accounts for the accelerated ignition of boron particles. Compared with the King model, as the ignition model of boron particles is formulated for the oxide layer removal by considering that it results from a boundary layer stripping mechanism, the oxide layer thickness thins at all times during the particle ignition and lower the ignition time.
Crackle Pitch Rises Progressively during Inspiration in Pneumonia, CHF, and IPF Patients
Authors: Vyshedskiy Andrey , Murphy Raymond
Published: March 2012

Objective. It is generally accepted that crackles are due to sudden opening of airways and that larger airways produce crackles of lower pitch than smaller airways do. As larger airways are likely to open earlier in inspiration than smaller airways and the reverse is likely to be true in expiration, we studied crackle pitch as a function of crackle timing in inspiration and expiration. Our goal was to see if the measurement of crackle pitch was consistent with this theory.Methods. Patients with a significant number of crackles were examined using a multichannel lung sound analyzer. These patients included 34 with pneumonia, 38 with heart failure, and 28 with interstitial fibrosis.Results. Crackle pitch progressively increased during inspirations in 79% of all patients. In these patients crackle pitch increased by approximately 40 Hz from the early to midinspiration and by another 40 Hz from mid to late-inspiration. In 10% of patients, crackle pitch did not change and in 11% of patients crackle pitch decreased. During expiration crackle pitch progressively decreased in 72% of patients and did not change in 28% of patients.Conclusion. In the majority of patients, we observed progressive crackle pitch increase during inspiration and decrease during expiration. Increased crackle pitch at larger lung volumes is likely a result of recruitment of smaller diameter airways. An alternate explanation is that crackle pitch may be influenced by airway tension that increases at greater lung volume. In any case improved understanding of the mechanism of production of these common lung sounds may help improve our understanding of pathophysiology of these disorders.