bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of neutral collision and radiative heat-loss function on self-gravitational instability of viscous thermally conducting partially-ionized plasma
Authors: Kaothekar Sachin , Soni Ghanshyam D. , Chhajlani Rajendra K.
Published: December 2012

The problem of thermal instability and gravitational instability is investigated for a partially ionized self-gravitating plasma which has connection in astrophysical condensations. We use normal mode analysis method in this problem. The general dispersion relation is derived using linearized perturbation equations of the problem. Effects of collisions with neutrals, radiative heat-loss function, viscosity, thermal conductivity and magnetic field strength, on the instability of the system are discussed. The conditions of instability are derived for a temperature-dependent and density-dependent heat-loss function with thermal conductivity. Numerical calculations have been performed to discuss the effect of various physical parameters on the growth rate of the gravitational instability. The temperature-dependent heat-loss function, thermal conductivity, viscosity, magnetic field and neutral collision have stabilizing effect, while density-dependent heat-loss function has a destabilizing effect on the growth rate of the gravitational instability. With the help of Routh-Hurwitz's criterion, the stability of the system is discussed.
Intramolecular arrangement of sensor and regulator overcomes relaxed specificity in hybrid two-component systems
Authors: Townsend Guy E. , Raghavan Varsha , Zwir Igor , Groisman Eduardo A.
Published: December 2012

Cellular processes require specific interactions between cognate protein partners and concomitant discrimination against noncognate partners. Signal transduction by classical two-component regulatory systems typically entails an intermolecular phosphoryl transfer between a sensor kinase (SK) and a cognate response regulator (RR). Interactions between noncognate partners are rare because SK/RR pairs coevolve unique interfaces that dictate phosphotransfer specificity. Here we report that the in vitro phosphotransfer specificity is relaxed in hybrid two-component systems (HTCSs) from the human gut symbiont
Bacteroides thetaiotaomicron
, which harbor both the SK and RR in a single polypeptide. In contrast, phosphotransfer specificity is retained in classical two-component regulatory systems from this organism. This relaxed specificity enabled us to rewire a HTCS successfully to transduce signals between noncognate SK/RR pairs. Despite the relaxed specificity between SK and RRs, HTCSs remained insulated from cross-talk with noncognate proteins in vivo. Our data suggest that the high local concentration of the SK and RR present in the same polypeptide maintains specificity while relaxing the constraints on coevolving unique contact interfaces.
How vision and movement combine in the hippocampal place code
Authors: Chen Guifen , King John A. , Burgess Neil , O'Keefe John
Published: December 2012

How do external environmental and internal movement-related information combine to tell us where we are? We examined the neural representation of environmental location provided by hippocampal place cells while mice navigated a virtual reality environment in which both types of information could be manipulated. Extracellular recordings were made from region CA1 of head-fixed mice navigating a virtual linear track and running in a similar real environment. Despite the absence of vestibular motion signals, normal place cell firing and theta rhythmicity were found. Visual information alone was sufficient for localized firing in 25% of place cells and to maintain a local field potential theta rhythm (but with significantly reduced power). Additional movement-related information was required for normally localized firing by the remaining 75% of place cells. Trials in which movement and visual information were put into conflict showed that they combined nonlinearly to control firing location, and that the relative influence of movement versus visual information varied widely across place cells. However, within this heterogeneity, the behavior of fully half of the place cells conformed to a model of path integration in which the presence of visual cues at the start of each run together with subsequent movement-related updating of position was sufficient to maintain normal fields.
The visual-gestural modality and beyond
Authors: Mohr Susanne
Published: December 2012

The article analyses cross-modal language contact between signed and spoken languages with special reference to the Irish Deaf community. This is exemplified by an examination of the phenomenon of mouthings in Irish Sign Language including its origins, dynamics, forms and functions. Initially, the setup of language contact with respect to Deaf communities and the sociolinguistics of the Irish Deaf community are discussed, and in the main part the article analyses elicited data in the form of personal stories by twelve native signers from the Republic of Ireland. The major aim of the investigation is to determine whether mouthings are yet fully integrated into ISL and if so, whether this integration has ultimately caused language change. Finally, it is asked whether traditional sociolinguistic frameworks of language contact can actually tackle issues of cross-modal language contact occurring between signed and spoken languages.
Parallelism revisited
Authors: Koulidobrova Helen
Published: December 2012

Previous research has argued that the null argument surfacing in ASL is comparable to its Spanish counterpart — agreement licensed pro (e.g. Rizzi 1986). This analysis has been applied to both subjects and objects of either all verb classes (Bahan et al. 2000) or agreeing verbs only (Lillo-Martin 1991). In this squib, I demonstrate that the nature of both the null subject and the null object in ASL does not neatly parallel that of Spanish, taken here to be a representative of consistent null subject languages (Biberauer et al. 2010).
The effect of morphological and functional variables on ranking position of professional junior Basque surfers
Authors: Fernández‐López Juan Ramón , Cámara Jesús , Maldonado Sara , Rosique‐Gracia Javier
Published: December 2012

The aim of this study was to analyse the association of morphology as well as functional outcomes during a paddling test with ranking position (RP) of competitive junior surfers. Ten male surfers (age, mean 17.60, s=2.06 years) performed a maximum incremental test on a modified ergometer (Ergo Vasa Swim, USA) to determine, per unit of weight, the relative heart rate at lactate threshold (RHRLT) and at onset of blood lactate accumulation (RHROBLA) and the relative power output at LT (RWLT) and at OBLA (RWOBLA). Anthropometrics were weight, height and sum of six skinfolds (subscapular, triceps, supraspinal, abdominal, anterior thigh and calf) and Heath‐Carter anthropometric somatotypes. A stepwise multiple regression was constructed to model and predict RP. Surfers shared a relative short stature and light weight, with a broader range of skinfold thickness (174.30, s=0.07 cm; 66.73, s=5.91 kg; 57.03, s=12.29 mm) and mean somatotype was ectomorphic‐mesomorph: 2.20–4.36–3.09 (Category 2). Two model equations were possible: (A) RP = − 244.550 RWOBLA+262.787; (B) RP = − 217.028·RWOBLA+31.21·endomorphy + 169.16 with 63.1% and 83% of variance explained, respectively. A hierarchical cluster analysis on the Euclidean distances of the variables in model B also distinguished between upper and lower ranking groups. RWOBLA was more useful than endomorphy, anthropometric measures and also than the other functional outcomes to predict RPs. RWOBLA and endomorphy should be considered important variables that may influence the success of these young competitive surfers.
Knee loading patterns in a simulated netball landing task
Authors: Stuelcken Max , Greene Andrew , Smith Richard , Vanwanseele Benedicte
Published: December 2012

The knee is a common site of injury in netball players. In this study, 10 high‐performance netball players underwent a biomechanical assessment of their single leg landing technique whilst receiving a pass. Three‐dimensional video and ground reaction force data were recorded using a motion analysis system. Net internal knee joint moments were calculated using a rigid body analysis and inverse dynamics. The kinematics of the support leg and front‐on video footage was used to investigate whether players adhered to guidelines on safe and effective landing strategies. Results indicated that for most players the internal valgus moment was the largest frontal plane knee moment during the landing phase. This may reflect a relatively greater need to resist varus knee excursion or may be related to the kinematics of the hip. For 6 of the 10 players the rapid change to an internal knee valgus moment coincided with hip adduction. Since an increase in the magnitude of the internal valgus moment may increase the compressive forces in the medial compartment of the knee, further work should be undertaken to determine if a neuromuscular training intervention to improve the strength of the hip musculature may be beneficial for these players. A large relative excursion of the knee compared to the hip may indicate that these players had a greater reliance on the more distal segments of the lower extremity for the attenuation of the ground reaction forces. This information may be used to better understand potential knee injury mechanisms in netball players.
Unnecessary Antimicrobial Use in Patients with Current or Recent Clostridium difficile Infection
Authors: Shaughnessy Megan K. , Amundson William H. , Kuskowski Michael A. , DeCarolis Douglas D. , Johnson James R. , Drekonja Dimitri M.
Published: December 2012

Objective.

To determine the fraction of unnecessary antimicrobial use among patients with current and/or recent Clostridium difficile infection (CDI).

Design.

Retrospective review from January 2004 through December 2006.

Setting.

Minneapolis Veterans Affairs Medical Center (MVAMC).

Participants.

Patients with new-onset CDI diagnosed at the MVAMC without another CDI diagnosis in the prior 30 days.

Methods.

Pharmacy and medical records were reviewed to identify incident CDI cases, non-CDI antimicrobial use during and up to 30 days after completion of CDI treatment, and patient characteristics. Two infectious disease physicians independently assessed non-CDI antimicrobial use, which was classified as unnecessary if not fully indicated. Factors associated with only unnecessary use were identified through univariable and multivariable analysis.

Results.

Of 246 patients with new-onset CDI, 141 (57%) received non-CDI antimicrobials during and/or after their CDI treatment, totaling 2,147 antimicrobial days and 445 antimicrobial courses. The two reviewers agreed regarding the necessity of antimicrobials in more than 99% of antimicrobial courses (85% initially, 14% after discussion). Seventy-seven percent of patients received at least 1 unnecessary antimicrobial dose, 26% of patients received only unnecessary antimicrobials, and 45% of total non-CDI antimicrobial days included unnecessary antimicrobials. The leading indications for unnecessary antimicrobial use were putative urinary tract infection and pneumonia. Drug classes frequently used unnecessarily were fluoroquinolones and β-lactams.

Conclusions.

Twenty-six percent of patients with recent CDI received only unnecessary (and therefore potentially avoidable) antimicrobials. Heightened awareness and caution are needed when antimicrobial therapy is contemplated for patients with recent CDI.
Log-concavity of asymptotic multigraded Hilbert series
Authors: McCabe Adam , Smith Gregory
Published: December 2012

We study the linear map sending the numerator of the rational function representing the Hilbert series of a module to that of its

r
r

-th Veronese submodule. We show that the asymptotic behaviour as

r
r

tends to infinity depends on the multidegree of the module and the underlying positively multigraded polynomial ring. More importantly, we give a polyhedral description for the asymptotic polynomial and prove that the coefficients are log-concave.
Pianos for the People: From Producer to Consumer in Britain, 1851–1914
Authors: Carnevali Francesca , Newton Lucy
Published: December 2012

During the second half of the nineteenth century, British society experienced a rise in real incomes and a change in its composition, with the expansion of the middle classes. These two factors led to a consumer revolution, with a growing, but still segmented, demand for household goods that could express status and aspiration. At the same time technological changes and new ways of marketing and selling goods made these goods more affordable. This paper analyzes these themes and the process of mediation that took place between producers, retailers, and consumers, by looking at the most culturally symbolic of nineteenth century consumer goods, the piano.
Two massive stars possibly ejected from NGC 3603 via a three-body encounter
Authors: Gvaramadze V. V. , Kniazev A. Y. , Chené A.-N. , Schnurr O.
Published: December 2012

We report the discovery of a bow-shock-producing star in the vicinity of the young massive star cluster NGC 3603 using archival data of the Spitzer Space Telescope. Follow-up optical spectroscopy of this star with Gemini-South led to its classification as O6 V. The orientation of the bow shock and the distance to the star (based on its spectral type) suggest that the star was expelled from the cluster, while the young age of the cluster (∼2 Myr) implies that the ejection was caused by a dynamical few-body encounter in the cluster’s core. The relative position on the sky of the O6 V star and a recently discovered O2 If*/WN6 star (located on the opposite side of NGC 3603) allows us to propose that both objects were ejected from the cluster via the same dynamical event – a three-body encounter between a single (O6 V) star and a massive binary (now the O2 If*/WN6 star). If our proposal is correct, then one can ‘weigh’ the O2 If*/WN6 star using the conservation of the linear momentum. Given a mass of the O6 V star of ≈30  M⊙, we found that at the moment of ejection the mass of the O2 If*/WN6 star was ≈175  M⊙. Moreover, the observed X-ray luminosity of the O2 If*/WN6 star (typical of a single star) suggests that the components of this originally binary system have merged (e.g., because of encounter hardening).
Adenosine A1 Receptors in Mouse Pontine Reticular Formation Depress Breathing, Increase Anesthesia Recovery Time, and Decrease Acetylcholine Release
Authors: Gettys George C. , Liu Fang , Kimlin Ed , Baghdoyan Helen A. , Lydic Ralph
Published: December 2012

Background:

Clinical and preclinical data demonstrate the analgesic actions of adenosine. Central administration of adenosine agonists, however, suppresses arousal and breathing by poorly understood mechanisms. This study tested the two-tailed hypothesis that adenosine A1 receptors in the pontine reticular formation (PRF) of C57BL/6J mice modulate breathing, behavioral arousal, and PRF acetylcholine release.

Methods:

Three sets of experiments used 51 mice. First, breathing was measured by plethysmography after PRF microinjection of the adenosine A1 receptor agonist N6-sulfophenyl adenosine (SPA) or saline. Second, mice were anesthetized with isoflurane and the time to recovery of righting response (RoRR) was quantified after a PRF microinjection of SPA or saline. Third, acetylcholine release in the PRF was measured before and during microdialysis delivery of SPA, the adenosine A1 receptor antagonist 1, 3-dipropyl-8-cyclopentylxanthine, or SPA and 1, 3-dipropyl-8-cyclopentylxanthine.

Results:

First, SPA significantly decreased respiratory rate (−18%), tidal volume (−12%), and minute ventilation (−16%). Second, SPA concentration accounted for 76% of the variance in RoRR. Third, SPA concentration accounted for a significant amount of the variance in acetylcholine release (52%), RoRR (98%), and breathing rate (86%). 1, 3-dipropyl-8-cyclopentylxanthine alone caused a concentration-dependent increase in acetylcholine, a decrease in RoRR, and a decrease in breathing rate. Coadministration of SPA and 1, 3-dipropyl-8-cyclopentylxanthine blocked the SPA-induced decrease in acetylcholine and increase in RoRR.

Conclusions:

Endogenous adenosine acting at adenosine A1 receptors in the PRF modulates breathing, behavioral arousal, and acetylcholine release. The results support the interpretation that an adenosinergic-cholinergic interaction within the PRF comprises one neurochemical mechanism underlying the wakefulness stimulus for breathing.
In vitro and in vivo replication of influenza A H1N1 WSN33 viruses with different M1 proteins
Authors: Ran Zhiguang , Chen Ying , Shen Huigang , Xiang Xiaoxiao , Liu Qinfang , Bawa Bhupinder , Qi Wenbao , Zhu Laihua , Young Alan , Richt Juergen , Ma Wenjun , Li Feng
Published: December 2012

The M1 protein is a major structural protein that has multiple functions in various steps within the life cycle of the influenza A virus (IAV). However, little is currently known about the role of M1 in IAV replication in vivo and the associated pathogenesis. In this study, six isogenic H1N1 WSN33 viruses, constructed to express unique M1 proteins derived from various strains, subtypes or WSN33 itself, were tested to determine in vitro and in vivo functional exchangeability of M1 proteins in the replication and pathogenesis of the WSN33 virus. Despite five chimeric M1 viruses replicating to levels similar to those of the parental WSN33 virus in cell cultures, all M1 chimeras exhibited improved replication and enhanced virulence in mice when compared with the WSN33 virus. Interestingly, M1 proteins derived from swine viruses caused more severe clinical diseases than those from human or quail. These data indicate that the M1 protein is an important determinant of viral replication and pathogenic properties in mice, although the functions of M1 observed in vivo are not adequately reflected in simple infections of cultured cells. Chimeric M1 viruses that are variable in their clinical manifestations described here will aid future understanding of the role of M1 in IAV pathogenesis.
Genomic characterization of lytic Staphylococcus aureus phage GH15: providing new clues to intron shift in phages
Authors: Gu Jingmin , Liu Xiaohe , Yang Mei , Li Yue , Sun Changjiang , Lu Rong , Song Jun , Zhang Qingming , Lei Liancheng , Feng Xin , Du Chongtao , Yu Hao , Yang Yongjun , Han Wenyu
Published: December 2012

Phage GH15 is a polyvalent phage that shows activity against a wide range of Staphylcoccus aureus strains. This study analysed the genome of GH15. The genome size of GH15 (139 806 bp) was found to be larger than that of the known staphylococcal phages, and the G+C content (30.23 mol%) of GH15 was lower than that of any other staphylococcal myovirus phages. By mass spectrometry, ten structural proteins were identified. Analysis revealed that GH15 was closely related to phages G1, ISP, A5W, Sb-1 and K, and was moderately related to Twort. In light of the variability in identity, coverage, G+C content and genome size, coupled with the large number of mosaicisms, there certainly were close evolutionary relationships from K to Sb-1, A5W, ISP, G1 and finally GH15. Interestingly, all the introns and inteins present in the above phages were absent in GH15 and there appeared to be intron loss in GH15 compared with the intron gain seen in other phages. A comparison of the intron- and intein-related genes demonstrated a clear distinction in the location of the insertion site between intron-containing and intron-free alleles, and this might lead to the establishment of a consensus sequence associated with the presence of an intron or intein. The comparative analysis of the GH15 genome sequence with other phages not only provides compelling evidence for the diversity of staphylococcal myovirus phages but also offers new clues to intron shift in phages.
Transport and stability of the vaccinia virus A34 protein is affected by the A33 protein
Authors: Breiman Adrien , Carpentier David C. J. , Ewles Helen A. , Smith Geoffrey L.
Published: December 2012

Vaccinia virus (VACV) has two infectious forms called intracellular mature virus and extracellular enveloped virus (EEV). Two of the seven viral proteins in the EEV outer envelope, A33 and A34, are type II membrane glycoproteins that each interact with another EEV protein called B5; however, evidence for direct A33–A34 interaction is lacking. The localization and stability of A34 is affected by B5 and here data are presented showing that A34 is also affected by A33. In the absence of A33, just as without B5, the level, localization and glycosylation profile of A34 was altered. However, the glycosylation profile of A34 without A33 is different to that observed in the absence of B5, and A34 accumulates in the Golgi apparatus rather than in the endoplasmic reticulum. Thus, A34 requires more than one other EEV protein for its processing and cellular transport.
On the gcd of local Rankin–Selberg integrals for even orthogonal groups
Authors: Kaplan Eyal
Published: December 2012

We study the Rankin–Selberg integral for a pair of representations of ${\rm SO}_{2l}\times {\rm GL}_{n}$, where ${\rm SO}_{2l}$ is defined over a local non-Archimedean field and is either split or quasi-split. The integrals span a fractional ideal, and its unique generator, which contains any pole which appears in the integrals, is called the greatest common divisor (gcd) of the integrals. We describe the properties of the gcd and establish upper and lower bounds for the poles. In the tempered case we can relate it to the $L$-function of the representations defined by Shahidi. Results of this work may lead to a gcd definition for the $L$-function.
The Effect of Determining Topography Parameters on Analyzing Elastic Contact Between Isotropic Rough Surfaces
Authors: Pawar Gorakh , Pawlus Pawel , Etsion Izhak , Raeymaekers Bart
Published: December 2012

The elastic contact between two computer generated isotropic rough surfaces is studied. First the surface topography parameters including the asperity density, mean summit radius, and standard deviation of asperity heights of the equivalent rough surface are determined using an 8-nearest neighbor summit identification scheme. Second, many cross sections of the equivalent rough surface are traced and their individual topography parameters are determined from their corresponding spectral moments. The topography parameters are also obtained from the average spectral moments of all cross sections. The asperity density is found to be the main difference between the summit identification scheme and the spectral moments method. The contact parameters such as the number of contacting asperities, real area of contact, and contact load for any given separation between the equivalent rough surface and a rigid flat are calculated by summing the contributions of all the contacting asperities using the summit identification model. These contact parameters are also obtained with the Greenwood-Williamson (GW) model using the topography parameters from each individual cross section and from the average spectral moments of all cross sections. Three different surfaces and three different sampling intervals were used to study how the method to determine topography parameters affects the resulting contact parameters. The contact parameters are found to vary significantly based on the method used to determine the topography parameters, and as a function of the autocorrelation length of the surface, as well as the sampling interval. Using a summit identification model or the GW model based on topography parameters obtained from a summit identification scheme is perhaps the most reliable approach.
Complete High Dimensional Inverse Characterization of Fractal Surfaces and Volumes
Authors: Michopoulos John G. , Iliopoulos Athanasios
Published: December 2012

In the present paper, we are describing a methodology for the determination of the complete set of parameters associated with the Weierstrass-Mandelbrot (W-M) function that can describe a fractal scalar field distribution defined by measured or computed data distributed on a surface or in a volume. Our effort is motivated not only by the need for accurate fractal surface and volume reconstruction but also by the need to be able to describe analytically a scalar field quantity distribution on a surface or in a volume that corresponds to various material properties distributions for engineering and science applications. Our method involves utilizing a refactoring of the W-M function that permits defining the characterization problem as a high dimensional inverse problem solved by singular value decomposition for the so-called phases of the function. Coupled with this process is a second level exhaustive search that enables the determination of the density of the frequencies involved in defining the trigonometric functions participating in the definition of the W-M function. Numerical applications of the proposed method on both synthetic and actual surface and volume data, validate the efficiency and the accuracy of the proposed approach. This approach constitutes a radical departure from the traditional fractal dimension characterization studies and opens the road for a very large number of applications.
Adaptive Finite-Time Synchronization of Non-Autonomous Chaotic Systems With Uncertainty
Authors: Pourmahmood Aghababa Mohammad , Pourmahmood Aghababa Hasan
Published: December 2012

Due to its useful applications in real world processes, synchronization of chaotic systems has attracted the attention of many researchers of mathematics, physics and engineering sciences. In practical situations, many chaotic systems are inevitably disturbed by model uncertainties and external disturbances. Furthermore, in practice, it is hard to determine the precise values of the chaotic systems’ parameters in advance. Besides, from a practical point of view, it is more desirable to achieve synchronization in a given finite time. In this paper, we investigate the problem of finite-time chaos synchronization between two different chaotic systems in the presence of model uncertainties, external disturbances and unknown parameters. Both autonomous and non-autonomous chaotic systems are taken into account. To tackle the unknown parameters, appropriate adaptation laws are proposed. Using the adaptation laws and finite-time control technique, an adaptive robust finite-time controller is designed to guarantee that the state trajectories slave system converge to the state trajectories of the master system in a given finite time. Some numerical simulations are presented to verify the robustness and usefulness of the proposed finite-time control technique.
On Fluid Compressibility in Switch-Mode Hydraulic Circuits—Part II: Experimental Results
Authors: Van de Ven James D.
Published: December 2012

In this paper, the author presents experimental work with a generic switch-mode hydraulic circuit that aims to validate a previously presented computational model, with primary focus on the energy loss due to fluid compressibility. While multiple previous papers have presented experimental works with switch-mode hydraulic circuits, the presented experimental system is unique due the capability of in-flow measurement of the entrained air in the hydraulic fluid. A designed experiment was run that varied the entrained air, system pressure, and volume of the fluid experiencing pressure fluctuations, defined as the switched volume. The calculated volumetric efficiency from these experiments ranged from to 61% to 75%, with efficiency increasing with decreased levels of entrained air, system pressure, and switched volume. These efficiency trends and the pressure profile in the switched volume agree well with the computational model presented in Part I of this two part set (Van de Ven, 2013, “On Fluid Compressibility in Switch-Mode Hydraulic Circuits—Part I: Modeling and Analysis,” ASME J. Dyn. Sys., Meas., Control, 135(2), p. 021013). Differences between the experimental results and the computational model include approximately 10% higher predicted efficiency and pressure oscillations found in the experimental work that were not predicted by the model.
A Study on the Tribological Characteristics of a Magneto-Rheological Elastomer
Authors: Lee Deuk-Won , Lee Kwanghee , Lee Chul-Hee , Kim Cheol-Hyun , Cho Won-Oh
Published: December 2012

Research on the applications of magneto-rheological (MR) elastomers in mechanical engineering has greatly expanded, whereas the performance of MR fluids in tribology has rarely been investigated. In this study, the tribological characteristics of an MR elastomer are identified in order to improve tribological performance with the activation of a magnetic field. Microscopic changes in the surface and in the MR particles are investigated. The friction and wear of an MR elastomer is measured using a pin-on-disc tester under applied and unapplied magnetic fields. In addition, the linear sliding friction of an MR elastomer with respect to different velocities and loads is measured using a linear sliding tester.
Nanoscale optical critical dimension measurement of a contact hole using deep ultraviolet spectroscopic ellipsometry
Authors: Chouaib Houssam , Zhao Qiang
Published: December 2012

Highly sensitive optical metrology techniques based on spectroscopic ellipsometry (SE) are required for three dimensional monitoring of line-profiles and critical-dimension (CD) of advanced design-rule devices. In this paper, theoretical and SE-based experimental techniques are used to study elliptical contact holes (CH) in a SiO2 layer. These structures were chosen because measuring their shapes is made difficult by the low optical contrast between air inside the holes and SiO2, as well as the strong coupling between critical shape parameters. Results showed that moving from conventional ultraviolet SE to deep ultraviolet SE (DUVSE) was a key to breaking the correlation between top and bottom CD and obtaining an accurate and physically realistic CH profile. The DUVSE-based CD results were validated using a scanning electron microscope.
Toward a streamlined projection of small device bias temperature instability lifetime distributions
Authors: Toledano-Luque María , Kaczer Ben , Grasser Tibor , Roussel Philippe J. , Franco Jacopo , Groeseneken Guido
Published: December 2012

As the CMOS device dimensions shrink to nanometer scale, the time-dependent VTH variability (heteroskedasticity) becomes evident due to the reduced number of stochastically behaving traps in the gate oxide. Consequently, the bias temperature instability (BTI) lifetime of nanometer-sized devices can only be correctly described in the form of time- (or workload-) dependent distributions. This paper discusses a streamlined procedure to obtain BTI lifetime projections for nanometer-scaled devices from the combination of measurements of a small sample set of nanoscaled devices and several large area test devices.
Electrical conductivity and photoresistance of atomic layer deposited Al-doped ZnO films
Authors: Mundle Rajeh M. , Terry Hampton S. , Santiago Kevin , Shaw Dante , Bahoura Messaoud , Pradhan Aswini K. , Dasari Kiran , Palai Ratnakar
Published: December 2012

Al-doped ZnO films were deposited by the atomic layer deposition (ALD) on both glass and sapphire (0001) substrates. The Al composition of the films was varied by controlling the Zn:Al pulse cycle ratios. The films were characterized by the atomic force microscopy, x-ray photoelectron spectroscopy, x-ray diffraction, and optical measurements. The Film resistivity was measured as a function of Zn:Al cycle ratios as well as temperature for films grown at various substrate temperature used for ALD deposition. The resistivity of the ALD grown films decreases significantly, and so as the increase in the carrier concentration as the cycle ratio increases. The systematic measurements of temperature dependence of resistivity of films at various cycle ratios clearly demonstrate the crossover of the metal–semiconductor–insulator phase with the function of temperature as well as the cycle ratios. The average transmission of all films is greater than 85% and the optical absorption increases significantly in the visible region as the cycle ratio increases. The authors observed a remarkable dependence of photoresistance on electrical conductivity for ALD-grown films with varying cycle ratios, which control the Al content in the film. Our results suggest that Al3+ ions are incorporated as substitutional or interstitial sites of the ZnO matrix. However, an addition of an excessive amount of Al content causes the formation of Al2O3 and related clusters as carrier traps opposed to electron donors, resulting in an increase in the resistivity and other associated phenomena.
Wetting transitions of polymers via thermal and plasma enhanced atomic layer depositions
Authors: Roy Amit K. , Deduytsche Davy , Detavernier Christophe
Published: December 2012

Polypropylene (PP) and a blend of poly(ethylene terephthalate)/cotton (PET/cotton) nonwoven fiber felts were modified using aluminum and zinc oxides via thermal and plasma enhanced atomic layer deposition (ALD and PEALD). Deposition of aluminum or zinc oxide on PP induced a wetting transition from the hydrophobic behavior characteristic of the untreated PP to a hydrophilic behavior for ALD coated PP. PEALD needed a fewer number of cycles to induce hydrophilic effect, compared to thermal ALD. This correlated with the observation of an initial nucleation delay for thermal ALD on PP, while PEALD resulted in deposition of oxide material from the initial cycles. The hydrophilic effect could be achieved for a wider range of deposition temperatures for PEALD as compared to thermal ALD. PEALD of aluminum and zinc oxides did not alter the surface properties of the PET/cotton felts, as they stayed hydrophilic even after 400 cycles of deposition, while thermal ALD of zinc oxide transformed hydrophilic PET/cotton felts to hydrophobic.
The Si3N4/TiN Interface: 2. Si3N4/TiN(001) Grown with a −7 V Substrate Bias and Analyzed In situ using Angle-resolved X-ray Photoelectron Spectroscopy
Authors: Haasch Richard T. , Patscheider Jörg , Hellgren Niklas , Petrov Ivan , Greene J. E.
Published: December 2012

Angle-resolved x-ray photoelectron spectroscopy (AR-XPS) was used to analyze Si3N4/TiN(001) bilayers grown by ultrahigh vacuum reactive magnetron sputter deposition onto MgO(001), with an electrically-floating substrate potential of −7 V, in mixed 1:1 Ar/N2 discharges maintained at a total pressure of 0.5 Pa (3.75 × 10−3 Torr). The TiN(001) films were grown at 600 °C and the 4-ML-thick Si3N4 overlayers at room temperature. AR-XPS spectra were obtained using incident monochromatic Al Kα x-radiation at 0.83401 nm. Si3N4/TiN(001) Ti 2p spectra reveal enhanced unscreened final-state satellite peaks, compared to Ti 2p spectra obtained from uncapped TiN(001), due to decreased electronic screening induced by Si3N4/TiN(001) bilayer interfacial polarization.
Low-frequency source for very long-range underwater communication
Authors: Mosca Frédéric , Matte Guillaume , Shimura Takuya
Published: December 2012

Very long-range underwater acoustic communication (UAC) is crucial for long cruising (>1000 km) autonomous underwater vehicles (AUVs). Very long-range UAC source for AUV must exhibit high electro-acoustic efficiency (>60%) and compactness. This paper describes the Janus-Hammer Bell (JHB) transducer that has been designed for this purpose and meets those requirements. The transducer works on the 450–550 Hz bandwidth and reaches source level above 200 dB (ref. 1 μPa at 1 m) with 1 kW excitation and full immersion capability. JHB source has been used for communication experiments by the Japanese institute for marine technology (Japan Agency for Marine-Earth Science and Technology) achieving a baud rate of 100 bits/s at 1000 km.
Reliability of human-supervised formant-trajectory measurement for forensic voice comparison
Authors: Zhang Cuiling , Morrison Geoffrey Stewart , Ochoa Felipe , Enzinger Ewald
Published: December 2012

Acoustic-phonetic approaches to forensic voice comparison often include human-supervised measurement of vowel formants, but the reliability of such measurements is a matter of concern. This study assesses the within- and between-supervisor variability of three sets of formant-trajectory measurements made by each of four human supervisors. It also assesses the validity and reliability of forensic-voice-comparison systems based on these measurements. Each supervisor's formant-trajectory system was fused with a baseline mel-frequency cepstral-coefficient system, and performance was assessed relative to the baseline system. Substantial improvements in validity were found for all supervisors' systems, but some supervisors' systems were more reliable than others.
Response to Comment on “The Local Structure of Amorphous Silicon”
Authors: Treacy M. M. J. , Borisenko K. B.
Published: December 2012

The averaged diffraction data alone cannot distinguish between models with different heterogeneous structures at length scales of about 2 nanometers, even when using high-resolution data. Although our approach to calculating diffraction intensities from the model differs from that of Roorda and Lewis, paracrystallinity in amorphous silicon is undeniably evident in the raw experimental fluctuation electron microscopy data.
The Evolutionary Landscape of Alternative Splicing in Vertebrate Species
Authors: Barbosa-Morais Nuno L. , Irimia Manuel , Pan Qun , Xiong Hui Y. , Gueroussov Serge , Lee Leo J. , Slobodeniuc Valentina , Kutter Claudia , Watt Stephen , Çolak Recep , Kim TaeHyung , Misquitta-Ali Christine M. , Wilson Michael D. , Kim Philip M. , Odom Duncan T. , Frey Brendan J. , Blencowe Benjamin J.
Published: December 2012

Whence Species Variation?

Vertebrates have widely varying phenotypes that are at odds with their much more limited proteincoding genotypes and conserved messenger RNA expression patterns. Genes with multiple exons and introns can undergo alternative splicing, potentially resulting in multiple protein isoforms (see the Perspective by

Papasaikas and Valcárcel

).

Barbosa-Morais
et al.

(p.
1587
) and

Merkin
et al.

(p.
1593
) analyzed alternative splicing across the genomes of a variety of vertebrates, including human, primates, rodents, opossum, platypus, chicken, lizard, and frog. The findings suggest that the evolution of alternative splicing has for the most part been very rapid and that alternative splicing patterns of most organs more strongly reflect the identity of the species rather than the organ type. Species-classifying alternative splicing can affect key regulators, often in disordered regions of proteins that may influence protein-protein interactions, or in regions involved in protein phosphorylation.
Tackling Meningitis in Africa
Authors: Thorsteinsdóttir Halla , Sáenz Tirso W.
Published: December 2012

How did two Latin American countries harness their scientific strengths to address a major medical problem in Africa?
Hepatitis B Virus Surface Antigen (HBsAg)-Positive and HBsAg-Negative Hepatitis B Virus Infection among Mother-Teenager Pairs 13 Years after Neonatal Hepatitis B Virus Vaccination
Authors: Yao Qing-Qing , Dong Xiao-Lian , Wang Xue-Cai , Ge Sheng-Xiang , Hu An-Qun , Liu Hai-Yan , Wang Yueping Alex , Yuan Quan , Zheng Ying-Jie
Published: December 2012

It is unclear whether a mother who is negative for hepatitis B virus surface antigen (HBsAg) but positive for hepatitis B virus (HBV) is at potential risk for mother-to-child transmission of HBV. This study, using a paired mother-teenager population, aimed to assess whether maternal HBsAg-negative HBV infection (
hn
HBI) is a significant source of child HBV infection (HBI). A follow-up study with blood collection has been conducted on the 93 mother-teenager pairs from the initial 135 pregnant woman-newborn pairs 13 years after neonatal HBV vaccination. Serological and viral markers of HBV have been tested, and phylogenetic analysis of HBV isolates has been done. The HBI prevalence was 1.9% (1
hn
HBI/53) for teenage children of non-HBI mothers, compared with 16.7% (1
hn
HBI/6) for those of
hn
HBI mothers and 2.9% (1 HBsAg-positive HBV infection [
hp
HBI]/34) for those of
hp
HBI mothers. Similar viral sequences have been found in one pair of whom both the mother and teenager have had
hn
HBI. In comparison with the
hp
HBI cases, those with
hn
HBI had a lower level of HBV load and a higher proportion of genotype-C strains, which were accompanied by differentiated mutations (Q129R, K141E, and Y161N) of the “a” determinant of the HBV surface gene. Our findings suggest that mother-to-teenager transmission of
hn
HBI can occur among those in the neonatal HBV vaccination program.
Investigation into Low-Level Anti-Rubella Virus IgG Results Reported by Commercial Immunoassays
Authors: Dimech Wayne , Arachchi Nilukshi , Cai Jingjing , Sahin Terri , Wilson Kim
Published: December 2012

Since the 1980s, commercial anti-rubella virus IgG assays have been calibrated against a WHO International Standard and results have been reported in international units per milliliter (IU/ml). Laboratories testing routine patients' samples collected 100 samples that gave anti-rubella virus IgG results of 40 IU/ml or less from each of five different commercial immunoassays (CIA). The total of 500 quantitative results obtained from 100 samples from each CIA were compared with results obtained from an in-house enzyme immunoassay (IH-EIA) calibrated using the WHO standard. All 500 samples were screened using a hemagglutination inhibition assay (HAI). Any sample having an HAI titer of 1:8 or less was assigned a negative anti-rubella virus antibody status. If the HAI titer was greater than 1:8, the sample was tested in an immunoblot (IB) assay. If the IB result was negative, the sample was assigned a negative anti-rubella virus IgG status; otherwise, the sample was assigned a positive status. Concordance between the CIA qualitative results and the assigned negative status ranged from 50.0 to 93.8% and 74.5 to 97.8% for the assigned positive status. Using a receiver operating characteristic analysis with the cutoff set at 10 IU/ml, the estimated sensitivity and specificity ranged from 70.2 to 91.2% and 65.9 to 100%, respectively. There was poor correlation between the quantitative CIA results and those obtained by the IH-EIA, with the coefficient of determination (
R
2
) ranging from 0.002 to 0.413. Although CIAs have been calibrated with the same international standard for more than 2 decades, the level of standardization continues to be poor. It may be time for the scientific community to reevaluate the relevance of quantification of anti-rubella virus IgG.
High Frequency and Diversity of Species C Enteroviruses in Cameroon and Neighboring Countries
Authors: Sadeuh-Mba Serge Alain , Bessaud Maël , Massenet Denis , Joffret Marie-Line , Endegue Marie-Claire , Njouom Richard , Reynes Jean-Marc , Rousset Dominique , Delpeyroux Francis
Published: December 2012

Human enteroviruses (HEVs) are endemic worldwide and among the most common viruses infecting humans. Nevertheless, there are very limited data on the circulation and genetic diversity of HEVs in developing countries and sub-Saharan Africa in particular. We investigated the circulation and genetic diversity of HEVs among 436 healthy children in a limited area of the far north region of Cameroon in 2008 and 2009. We also characterized the genetic biodiversity of 146 nonpolio enterovirus (NPEV) isolates obtained throughout the year 2008 from stool specimens of patients with acute flaccid paralysis (AFP) in Cameroon, Chad, and Gabon. We found a high rate of NPEV infections (36.9%) among healthy children in the far north region of Cameroon. Overall, 45 different HEV types were found among healthy children and AFP patients. Interestingly, this study uncovered a high rate of HEVs of species C (HEV-C) among all typed NPEVs: 63.1% (94/149) and 39.5% (49/124) in healthy children and AFP cases, respectively. Besides extensive circulation, the most prevalent HEV-C type, coxsackievirus A-13, featured a tremendous intratypic diversity. Africa-specific HEV lineages were discovered, including HEV-C lineages and the recently reported EV-A71 “genogroup E.” Virtually all pathogenic circulating vaccine-derived polioviruses (cVDPVs) that have been fully characterized were recombinants between oral poliovaccine (OPV) strains and cocirculating HEV-C strains. The extensive circulation of diverse HEV-C types and lineages in countries where OPV is massively used constitutes a major viral factor that could promote the emergence of recombinant cVDPVs in the Central African subregion.
Rapid Identification of Bacteria and Yeasts from Positive-Blood-Culture Bottles by Using a Lysis-Filtration Method and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrum Analysis with the SARAMIS Database
Authors: Fothergill Amy , Kasinathan Vyjayanti , Hyman Jay , Walsh John , Drake Tim , Wang Yun F. (Wayne)
Published: December 2012

Rapid identification of microorganisms causing bloodstream infections directly from a positive blood culture would decrease the time to directed antimicrobial therapy and greatly improve patient care. Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry (MS) is a fast and reliable method for identifying microorganisms from positive culture. This study evaluates the performance of a novel filtration-based method for processing positive-blood-culture broth for immediate identification of microorganisms by MALDI-TOF with a Vitek MS research-use-only system (VMS). BacT/Alert non-charcoal-based blood culture bottles that were flagged positive by the BacT/Alert 3D system were included. An aliquot of positive-blood-culture broth was incubated with lysis buffer for 2 to 4 min at room temperature, the resulting lysate was filtered through a membrane, and harvested microorganisms were identified by VMS. Of the 259 bottles included in the study, VMS identified the organisms in 189 (73%) cultures to the species level and 51 (19.7%) gave no identification (ID), while 6 (2.3%) gave identifications that were considered incorrect. Among 131 monomicrobic isolates from positive-blood-culture bottles with one spot having a score of 99.9%, the IDs for 131 (100%) were correct to the species level. In 202 bottles where VMS was able to generate an ID, the IDs for 189 (93.6%) were correct to the species level, whereas the IDs provided for 7 isolates (3.5%) were incorrect. In conclusion, this method does not require centrifugation and produces a clean spectrum for VMS analysis in less than 15 min. This study demonstrates the effectiveness of the new lysis-filtration method for identifying microorganisms directly from positive-blood-culture bottles in a clinical setting.