bluuebunny/crossref_metadata_2025 huggingface dataset:
Phylogenetic relatedness predicts priority effects in nectar yeast communities
Authors: Peay Kabir G. , Belisle Melinda , Fukami Tadashi
Published: July 2011

Priority effects, in which the outcome of species interactions depends on the order of their arrival, are a key component of many models of community assembly. Yet, much remains unknown about how priority effects vary in strength among species in a community and what factors explain this variation. We experimented with a model natural community in laboratory microcosms that allowed us to quantify the strength of priority effects for most of the yeast species found in the floral nectar of a hummingbird-pollinated shrub at a biological preserve in northern California. We found that priority effects were widespread, with late-arriving species experiencing strong negative effects from early-arriving species. However, the magnitude of priority effects varied across species pairs. This variation was phylogenetically non-random, with priority effects stronger between closer relatives. Analysis of carbon and amino acid consumption profiles indicated that competition between closer relatives was more intense owing to higher ecological similarity, consistent with Darwin's naturalization hypothesis. These results suggest that phylogenetic relatedness between potential colonists may explain the strength of priority effects and, as a consequence, the degree to which community assembly is historically contingent.
Faith healing in paediatrics: what do we know about its relevance to clinical practice?
Authors: Baverstock A. , Finlay F.
Published: July 2011

There is widespread use of complementary or alternative medicine among adults and children. Families may use faith healing alongside conventional medicine or as an alternative. In their clinical practice, professionals should be aware of this and need to consider asking patients and their families about complementary or alternative medicine use, including faith healing.
Immunoglobulin‐E‐binding epitopes of wheat allergens in patients with food allergy to wheat and in mice experimentally sensitized to wheat proteins
Authors: Denery‐Papini S. , Bodinier M. , Pineau F. , Triballeau S. , Tranquet O. , Adel‐Patient K. , Moneret‐Vautrin D.A. , Bakan B. , Marion D. , Mothes T. , Mameri H. , Kasarda D.
Published: July 2011

Background At present, B cell epitopes involved in food allergy to wheat are known only for a few allergens and a few categories of patients.

Objective To characterize the epitopes of different wheat kernel allergens: α‐, γ, ω2, and ω5‐gliadin, a low‐molecular‐weight (LMW) glutenin subunit, and a lipid transfer protein (LTP1) recognized by allergic patients and by sensitized mice and provide further understanding of the role of structure in determining allergic response.

Methods Sera were obtained from 39 patients suffering from food allergy to wheat. BALB/c mice were sensitized to gliadins or LTP1 by intraperitoneal immunizations. Continuous epitopes bound by IgE were delineated by the Pepscan technique. The response to reduced, alkylated LTP1 was compared with that of the native form to evaluate the importance of protein folding on IgE reactivity.

Results Few continuous epitopes of LTP1 reacted with IgE from allergic patients and mice, but one of them was common to several patients and sensitized mice. The unfolded protein was not recognized by either patient or mouse IgE, emphasizing the major role of LTP1 folding and discontinuous epitopes in IgE‐binding. In contrast, many continuous epitopes were detected by patient and mouse IgE especially for an ω5‐gliadin, which is an unstructured protein, and to a lesser extent, for the other gliadins and a LMW‐glutenin subunit.

Conclusion and Clinical Relevance The conformation of LTP1 appeared to have a strong impact on the type of IgE‐binding epitopes elicited by this protein in both man and mouse. The responses in mice sensitized to gliadins or LTP1 were sufficiently comparable with the human response in terms of IgE‐binding epitopes to provide support for the use of the mouse model in further investigations.

Cite this as: S. Denery‐Papini, M. Bodinier, F. Pineau, S. Triballeau, O. Tranquet, K. Adel‐Patient, D.A. Moneret‐Vautrin, B. Bakan, D. Marion, T. Mothes, H. Mameri and D. Kasarda, Clinical & Experimental Allergy, 2011 (41) 1478–1492.
Transformational leadership: effect on the job satisfaction of Registered Nurses in a hospital in China
Authors: Wang Xiaohui , Chontawan Ratanawadee , Nantsupawat Raymoul
Published: July 2011

wang x., chontawan r. & nantsupawat r. (2012) Transformational leadership: effect on the job satisfaction of Registered Nurses in a hospital in China.Journal of Advanced Nursing 68(2), 444–451.

Aim. The aim of this study was to describe the relationship between the transformational leadership of nurse managers and job satisfaction among clinical Registered Nurses at a tertiary care hospital in China.

Background. The healthcare system is changing rapidly. Research in Western countries has shown that transformational leadership affects job satisfaction. However, very little research related to this subject has been conducted in healthcare settings in China.

Methods. The sample consisted of 238 nurses who work at a tertiary care hospital in China. Data were collected from April to August 2006. Research instruments included a demographic data form, a Leadership Practice Inventory and a Job Satisfaction Scale for clinical registered nurses.

Findings. Both the transformational leadership of nurse managers and job satisfaction among clinical Registered Nurses were at a moderate level. There was a statistically significant positive correlation between the transformational leadership of nurse managers and job satisfaction (r = 0·556,P < 0·001).

Conclusion. The findings indicate that the transformational leadership of nurse managers could have an effect on the job satisfaction of clinical Registered Nurses.
Connectedness in the context of patient–provider relationships: a concept analysis
Authors: Phillips‐Salimi Celeste R. , Haase Joan E. , Kooken Wendy Carter
Published: July 2011

PHILLIPS‐SALIMI c.r., haase j.e. & kooken w.c. (2012) Connectedness in the context of patient–provider relationships: a concept analysis. Journal of Advanced Nursing68(1), 230–245.

Aim.  This paper is a report of an analysis of the concept of connectedness.

Background.  Previous attempts to conceptualize patient–provider relationships were limited in explaining how such relationships are fostered and maintained, and how they influence patient outcomes. Connectedness is a concept that may provide insights into the advantages of patient–provider relationships; however, the usefulness of this concept in health care is limited by its conceptual ambiguity. Although connectedness is widely used to describe other social relationships, little consistency exists among its definitions and measures.

Data sources.  Sources identified through CINAHL, OVID, PubMed and PsychINFO databases and references lists of selected articles between 1983 and 2010.

Review methods.  A hybrid concept analysis approach was used, involving a combination of traditional concept analysis strategies that included: describing historical conceptualizations, identifying attributes, critiquing existing definitions, examining boundaries and identifying antecedents and consequences.

Results.  Using five distinct historical perspectives, seven attributes of connectedness were identified: intimacy, sense of belonging, caring, empathy, respect, trust and reciprocity. A broad definition of connectedness, which can be used in the context of patient–provider relationships, was developed. A preliminary theoretical framework of connectedness was derived from the identified antecedents, attributes and consequences.

Conclusion.  Research efforts to advance the concept of connectedness in patient–provider relationships have been hampered by a lack of conceptual clarity. This concept analysis offers a clearer understanding of connectedness, provides recommendations for future research and suggests practice implications.
Feasibility of a closed‐system cell processor (ACP215) for automated preparation of washed platelet concentrates
Authors: Oikawa S. , Sasaki D. , Kikuchi M. , Sawamura Y. , Itoh T.
Published: July 2011

Background and Objectives  This study was aimed at evaluating the feasibility of the ACP215 closed‐system cell processor for preparing washed platelet concentrates.

Material and Methods  Platelet washing was performed with either the ACP215 system or the manual technique with M‐sol. Plasma protein removal and platelet recovery were estimated, and the washed platelet concentrates were stored for 5 days. Samples were collected after washing and on days 1, 3 and 5 of storage to determine the effects of the washing methods on the in vitro platelet qualities (platelet count, platelet volume, pH, glucose and lactate concentrations, hypotonic shock response, aggregation response and CD62P expression level).

Results  Platelet recovery was 86·9 ± 2·1% and 85·9 ± 1·9% (P = 0·305), and plasma protein removal was 95·8 ± 0·9% and 96·9 ± 0·7% (P = 0·016) after washing with the ACP215 system and manual technique, respectively. No statistically significant differences in the in vitro platelet qualities were observed between the washing methods.

Conclusion  The ACP215 system is a feasible alternative to manual, labour‐intensive, techniques for preparing washed platelet concentrates.
The sensitivity of fluorescent‐light cystoscopy for the detection of carcinoma in situ (CIS) of the bladder: a meta‐analysis with comments on gold standard
Authors: Isfoss Björn L.
Published: July 2011

What's known on the subject? and What does the study add?

Fluorescent‐light cystoscopy has a high sensitivity, relative to that of white light cystoscopy, for carcinoma in situ of the bladder. However, this systematic review reveals that the absolute sensitivity is unknown due to the absence of proper gold standard which is microscopic examination of whole bladders.

A literature search was conducted to identify peer‐reviewed study reports on the sensitivity of fluorescent‐light cystoscopy (FLC) for the detection of carcinoma in situ (CIS) of the bladder.

Data from 16 original studies comprising 1503 patients were pooled.

The claimed sensitivity of FLC for detecting patients with CIS using the most commonly reported intravesical agents 5‐aminolevulinic acid or hexaminolevulinic acid was 92.4%, while that of white‐light cystoscopy (WLC) was 60.5%. The two agents did not differ significantly for sensitivity.

It must be pointed out that a ‘gold standard’ is lacking in FLC studies.

The occurrence of CIS of the bladder can only be established by the pathological examination of whole bladders. The true sensitivities of various modes of cystoscopy for detecting CIS can be revealed if patients scheduled for cystectomy are first examined with WLC, FLC, and optionally random biopsies.

The absolute sensitivity of FLC for detecting CIS of the bladder is not yet known.
Informal Employment and the Role of Regional Governance
Authors: Jonasson Erik
Published: July 2011

The aim of this paper is to provide an explanation to why the degree of informal employment may vary substantially between different regions within a country. In Brazil, 45% of workers in the urban labor force are employed informally. The degree of informal employment, however, varies substantially across regions, with some cities having 20% and others having 80% or more of their labor force in the informal sector. The hypothesis assessed here is that the quality of local governance—or government effectiveness—affects the decisions of workers and businesses as to whether to participate in the formal or the informal sector. The empirical analysis, based on data from 5500 Brazilian municipalities, shows that informal employment is lower in regions with better governance, higher average education, and with a relatively large manufacturing sector. Endogeneity concerns are addressed as part of a series of robustness checks of the results.
Exploring the Links Between Corruption and Growth
Authors: Hodge Andrew , Shankar Sriram , Rao D. S. Prasada , Duhs Alan
Published: July 2011

This paper models the transmission channels through which corruption indirectly affects growth. Results suggest that corruption hinders growth through its adverse effects on investment, human capital, and political instability, while fostering growth by reducing government consumption and, less robustly, increasing trade openness. Overall, a total negative effect of corruption on growth is estimated from these channels. These effects are found to be robust to modifications in model specification, sample coverage, and estimation techniques as well as tests for model exhaustiveness. The negative effect of corruption on growth is found to diminish in economies with low governance levels or a high degree of regulation. No one‐size‐fits‐all policy response appears supportable.
Norbert Elias and Developmental Psychology
Authors: Gabriel Norman
Published: July 2011

This paper looks at the important similarities between Norbert Elias and two of the most well-known developmental psychologists of childhood, John Bowlby and Lev Vygotsky. After discussing some of the connections in their approach to the social learning of young children, it argues that Elias's perspective is more suitable for integrating the affective and cognitive aspects of early development and comparing the many different types of language that humanity has developed. Long-term research of parent–child relations in different cultures can also illuminate some of the ways in which our ancestors developed a range of caring and protective arrangements for the survival of their offspring.
Norbert Elias, the Civilizing Process and Penal Development in Modern Society
Authors: Pratt John
Published: July 2011

For much of the twentieth century the punishment of offenders in modern society came to be administered on a scientific, rational basis with policy driven largely by expert knowledge. The anonymity of the prison, as a place for reflection and rehabilitation, steadily replaced the pre-modern drama and spectacle of punishment to the human body. Recently, though, some modern societies (particularly those in the Anglophone world) have seen recourse to more expressive and severe penalties, driven more by public opinion than by expert knowledge. Other modern societies, however (particularly the Scandinavian countries) remain largely immune to these trends. This article outlines and explores these contrasting trends and developments and uses Norbert Elias's work on the civilizing process to explain them.
Le Carte Blanc or la Carte Blanche? Bilingual Children's Acquisition of French Adjective Agreement
Authors: Nicoladis Elena , Marchak Kristan
Published: July 2011

Because of less exposure to either language, bilingual children's language acquisition can be delayed relative to monolingual children in domains related to input frequency. This study predicted that the acquisition of gender agreement with adjectives in French would be delayed in bilingual children on a picture description task. The results showed that French‐English bilingual preschoolers were less accurate with feminine noun‐adjective agreement than monolinguals, a difference attributable to the differences in vocabulary scores, but not significantly less accurate with feminine determiner‐adjective agreement. The bilinguals were significantly less accurate with determiner‐noun agreement, a difference not attributable to vocabulary score differences. We argue that fewer input tokens lead to delayed gender agreement and fewer input types lead to delayed gender assignment.
Management of the airway without the use of neuromuscular blocking agents: the use of remifentanil
Authors: Fotopoulou Georgia , Theocharis Stamatios , Vasileiou Ioanna , Kouskouni Evangelia , Xanthos Theodoros
Published: July 2011

Remifentanil belongs to opioid drugs, and its pharmacokinetic characteristics make it unique in this class of drugs and appropriate for use during intubation without neuromuscular blockage. This up‐to‐date review aims to summarize the findings of recent studies regarding remifentanil and intubation. Remifentanil combined either with propofol or with inhaled anesthetic agents has been proved to provide acceptable intubating conditions. Regarding children patients, remifentanil can be used safely, and as far as intubating conditions are concerned, its effectiveness is as excellent as with neuromuscular blockage. Strong evidence exists that illuminates the usefulness of the drug in cases of difficult airway as well as in neuromuscular diseases. Beyond all these favorable characteristics, anesthesiologists must be conscious with the use of remifentanil.
Strategic voting and effective representation thresholds: Evidence from three Spanish general elections
Authors: VIÑUELA ENRIQUE GARCÍA , ARTÉS JOAQUÍN
Published: July 2011

The extent of strategic voting in the Spanish general elections of 2000, 2004 and 2008 is estimated using a new measure of strategic incentives suitable for proportional representation systems that avoids some of the problems associated with lagged variables. Strategic behaviour increased from 12 to 33 per cent of the electoral base of the United Left Party, the major victim of strategic defection. This estimate is a conservative one as elite mobilisation is controlled for in the constituencies, which is unusual in the literature on strategic voting that uses regression‐based methods.
An Overexpression Screen in Saccharomyces cerevisiae Identifies Novel Genes that Affect Endocytic Protein Trafficking
Authors: Arlt Henning , Perz Angela , Ungermann Christian
Published: July 2011

A large number of proteins involved in the biogenesis of yeast endosomes and vacuoles have been identified based on screens that scored for inactivation of proteins. Such screens may, however, miss important regulators of the pathway. Here, we present a visual screen in which we examined the effects on vacuole morphology if any of the 6153 yeast open reading frames was overexpressed. Using a progressive screening procedure, we could identify a total of 53 genes. Among the most striking endosomal proteins are the CORVET/HOPS subunits Vps3, Vps18 and Vps39 and the putative tethering inhibitor Ivy1. Furthermore, six endosomal sorting complex related to transport (ESCRT) proteins led to altered vacuole morphology if overproduced. Among the novel proteins, we identify Yer128w as an endosomal protein that interacts with the AAA‐ATPase Vps4, and therefore named it Vfa1 (Vps Four‐Associated 1). We present evidence on the possible role of these novel proteins in trafficking to the vacuole. Our data provide novel insights into the regulation of protein trafficking.
Extracorporeal Ultrafiltration vs Conventional Diuretic Therapy in Advanced Decompensated Heart Failure
Authors: Hanna Mazen A. , Wilson Tang W.H. , Teo Boon W. , O’Neill James O. , Weinstein David M. , Lau Sey M. , Van Lente Frederick , Starling Randall C. , Paganini Emil P. , Taylor David O.
Published: July 2011

Compared with conventional diuretic (CD) therapy, ultrafiltration (UF) is associated with greater weight loss and fewer re‐hospitalizations in patients admitted with decompensated heart failure (HF). Concerns have been raised regarding its safety and efficacy in patients with more advanced heart failure. The authors conducted a single‐center, prospective, randomized controlled trial in patients with advanced HF admitted to an intensive care unit for hemodynamically guided therapy, comparing UF (n=17) with CD (n=19) at admission. The primary end point was the time required for pulmonary capillary wedge pressure (PCWP) to be maintained at a value of ≤18 mm Hg for at least 4 consecutive hours. Secondary end points included levels of cytokines and neurohormones, as well as several clinical outcomes. In our study cohort, the time to achieve the primary end point was lower in the UF group but did not reach statistical significance (P = .08). UF resulted in greater weight reduction, higher total volume removed, and shorter hospital length of stay. There were no differences in kidney function, biomarkers, or adverse events. In patients with advanced HF under hemodynamically tailored therapy, UF can be safely performed to achieve higher average volume removed than CD therapy without leading to adverse outcomes. Congest Heart Fail. 2012;18:54–63. ©2011 Wiley Periodicals, Inc.
Residual Stresses in Roller Expanded Tube-Tubesheet Joints With Large Initial Clearance and Grooves
Authors: Shuaib A. N. , Duffuaa O. M. , Merah N. , Al-Nassar Y.
Published: July 2011

Heat exchanger tube rolling introduces tensile residual stresses in the expanded part of the tube and the transition zone between the expanded and unexpanded regions of the tube. These tensile residual stresses accelerate fatigue crack initiation and enhance small crack propagation and may cause stress corrosion cracking of the tube if it is exposed to a corrosive environment. In this paper, an axisymmetric finite element model has been used to evaluate the effect of large initial tube-tubesheet radial clearance and to evaluate the effects of grooves machined in the tubesheet hole on the distributions and magnitudes of the radial deformation of tube walls and the residual stresses along the expanded length of the tube and in the transition zone. The results have revealed the presence of tensile and compressive residual axial and hoop stresses in the inner and outer surfaces of the tubes with various degrees of severity.
Shakedown Limit Load Determination for a Kinematically Hardening 90 deg Pipe Bend Subjected to Steady Internal Pressures and Cyclic Bending Moments
Authors: Abdalla Hany F. , Younan Maher Y. A. , Megahed Mohammad M.
Published: July 2011

A simplified technique for determining the lower bound shakedown limit load of a structure, employing an elastic–perfectly plastic (EPP) material model, was previously developed and successfully applied to a long radius 90 deg pipe bend (Abdalla et al., 2006, “Determination of Shakedown Limit Load for a 90 Degree Pipe Bend Using a Simplified Technique,” ASME J. Pressure Vessel Technol., 128, pp. 618–624). The pipe bend is subjected to steady internal pressure magnitudes and cyclic bending moments. The cyclic bending includes three different loading patterns, namely, in-plane closing, in-plane opening, and out-of-plane bending moment loadings. The simplified technique utilizes the finite element (FE) method and employs a small displacement formulation to determine the shakedown limit load without performing lengthy time consuming full elastic-plastic (ELPL) cyclic loading FE simulations or conventional iterative elastic techniques. In the present research, the simplified technique is further modified to handle structures employing an elastic-linear strain hardening material model following Ziegler’s linear kinematic hardening (KH) rule. The shakedown limit load is determined through the calculation of residual stresses developed within the pipe bend structure accounting for the back stresses, determined from the KH shift tensor, responsible for the rigid translation of the yield surface. The outcomes of the simplified technique showed an excellent correlation with the results of full ELPL cyclic loading FE simulations. The shakedown limit moments output by the simplified technique are utilized to generate shakedown diagrams (Bree diagrams) of the pipe bend for a spectrum of steady internal pressure magnitudes. The generated Bree diagrams are compared with the ones previously generated employing the EPP material model. These indicated relatively conservative shakedown limit moments compared with the ones employing the KH rule.
Effects of Trenched Holes on Film Cooling of a Contoured Endwall Nozzle Vane
Authors: Barigozzi Giovanna , Franchini Giuseppe , Perdichizzi Antonio , Ravelli Silvia
Published: July 2011

The present paper investigates the effects of the application of trenched holes in the front part of a contoured film cooled endwall. Two trench configurations were tested, changing the trench depth. Tests have been carried out at low speed (M2is=0.2) and low inlet turbulence intensity level, with coolant mass flow rate ratio varied within the 0.5–2.5% range. Pressure probe traverses were performed downstream of the vane trailing edge to show the secondary flow field modifications and to evaluate trench additional losses. Endwall distributions of film cooling effectiveness have been obtained by the thermochromic liquid crystal (TLC) technique. For each injection condition, energy loss coefficient and film cooling effectiveness distributions were analyzed and compared with the ones obtained from rows of cylindrical holes. Laterally and area averaged effectiveness as well as pitch and mass averaged kinetic energy loss coefficients were computed to enlighten any change induced by the introduction of trenched holes. A uniform and high thermal coverage was obtained in the region just downstream of the trench, but it quickly decayed because of enforced mixing of coolant with main flow. Compared with the cylindrical hole configuration, trenches are able to provide a higher global cooling effectiveness, but a larger amount of coolant injection is required. The introduction of both trenches is responsible for a secondary thermodynamic loss increase of about 0.7% at low coolant injection rates. Increasing the blowing rates, the additional loss vanishes.
Direct-numerical simulation of the glottal jet and vocal-fold dynamics in a three-dimensional laryngeal model
Authors: Zheng X. , Mittal R. , Xue Q. , Bielamowicz S.
Published: July 2011

An immersed-boundary method based flow solver coupled with a finite-element solid dynamics solver is employed in order to conduct direct-numerical simulations of phonatory dynamics in a three-dimensional model of the human larynx. The computed features of the glottal flow including mean and peak flow rates, and the open and skewness quotients are found to be within the normal physiological range. The flow-induced vibration pattern shows the classical “convergent-divergent” glottal shape, and the vibration amplitude is also found to be typical for human phonation. The vocal fold motion is analyzed through the method of empirical eigenfunctions and this analysis indicates a 1:1 modal entrainment between the “adduction-abduction” mode and the “mucosal wave” mode. The glottal jet is found to exhibit noticeable cycle-to-cycle asymmetric deflections and the mechanism underlying this phenomenon is examined.
Active noise attenuation in ventilation windows
Authors: Huang Huahua , Qiu Xiaojun , Kang Jian
Published: July 2011

The feasibility of applying active noise control techniques to attenuate low frequency noise transmission through a natural ventilation window into a room is investigated analytically and experimentally. The window system is constructed by staggering the opening sashes of a spaced double glazing window to allow ventilation and natural light. An analytical model based on the modal expansion method is developed to calculate the low frequency sound field inside the window and the room and to be used in the active noise control simulations. The effectiveness of the proposed analytical model is validated by using the finite element method. The performance of the active control system for a window with different source and receiver configurations are compared, and it is found that the numerical and experimental results are in good agreement and the best result is achieved when the secondary sources are placed in the center at the bottom of the staggered window. The extra attenuation at the observation points in the optimized window system is almost equivalent to the noise reduction at the error sensor and the frequency range of effective control is up to 390 Hz in the case of a single channel active noise control system.
Noise-induced temporary threshold shift and recovery in Yangtze finless porpoises Neophocaena phocaenoides asiaeorientalis
Authors: Popov Vladimir V. , Supin Alexander Ya. , Wang Ding , Wang Kexiong , Dong Lijun , Wang Shiyong
Published: July 2011

In Yangtze finless porpoises Neophocaena phocaenoides asiaeorientalis, the effects of fatiguing noise on hearing thresholds at frequencies of 32, 45, 64, and 128 kHz were investigated. The noise parameters were: 0.5-oct bandwidth, −1 to +0.5 oct relative to the test frequency, 150 dB re 1 μPa (140–160 dB re 1 μPa in one measurement series), with 1–30 min exposure time. Thresholds were evaluated using the evoked-potential technique allowing the tracing of threshold variations with a temporal resolution better than 1 min. The most effective fatiguing noise was centered at 0.5 octave below the test frequency. The temporary threshold shift (TTS) depended on the frequencies of the fatiguing noise and test signal: The lower the frequencies, the bigger the noise effect. The time-to-level trade of the noise effect was incomplete: the change of noise level by 20 dB resulted in a change of TTS level by nearly 20 dB, whereas the tenfold change of noise duration resulted in a TTS increase by 3.8–5.8 dB.
Frequency response and design parameters for differential microbarometers
Authors: Mentink Johan H. , Evers Läslo G.
Published: July 2011

The study of infrasound is experiencing a renaissance since it was chosen as a verification technique for the Comprehensive Nuclear-Test-Ban Treaty. Source identification is one of the main topics of research which involves detailed knowledge on the source time function, the atmosphere as medium of propagation, and the measurement system. Applications are also foreseen in using infrasound as passive probe for the upper atmosphere, taking the field beyond its monitoring application. Infrasound can be conveniently measured with differential microbarometers. An accurate description of the instrument response is an essential need to be able to attribute the recorded infrasound to a certain source or atmospheric properties. In this article, a detailed treatment is given of the response of a differential microbarometer to acoustic signals. After an historical introduction, a basic model for the frequency response is derived with its corresponding poles and zeros. The results are explained using electric analogs. In addition, thermal conduction is added to the model in order to capture the transition between adiabatic and isothermal behavior. Also discussed are high-frequency effects and the effect of external temperature variations. Eventually, the design parameters for differential microbarometers are derived.
Optimization of pulsed focused ultrasound exposures for hyperthermia applications
Authors: Wang Shutao , Frenkel Victor , Zderic Vesna
Published: July 2011

Hyperthermic temperatures, with potential applications in drug/gene delivery and chemo/radio sensitization, may be generated in biological tissues by applying focused ultrasound (FUS) in pulsed mode. Here, a strategy for optimizing FUS exposures for hyperthermia applications is proposed based on theoretical simulations and in vitro experiments. Initial simulations were carried out for tissue-mimicking phantoms, and subsequent thermocouple measurements allowed for validation of the simulation results. Advanced simulations were then conducted for an ectopic, murine xenograft tumor model. The ultrasound exposure parameters investigated in this study included acoustic power (3–5 W), duty cycle (DC) (10%–50%), and pulse repetition frequency (PRF) (1–5 Hz), as well as effects of tissue perfusion. The thermocouple measurements agreed well with simulation outcomes, where differences between the two never exceeded 1.9%. Based on a desired temperature range of 39–44 °C, optimal tumor coverage (40.8% of the total tumor volume) by a single FUS exposure at 1 MHz was achieved with 4 W acoustic power, 50% DC, and 5 Hz PRF. Results of this study demonstrate the utility of a proposed strategy for optimizing pulsed-FUS induced hyperthermia. These strategies can help reduce the requirement for empirical animal experimentation, and facilitate the translation of pulsed-FUS applications to the clinic.
Influence of impression of vehicle styling on loudness of acceleration sounds in cabin
Authors: Yoshida Junji , Igata Takumi
Published: July 2011

The influence of participants’ impressions of vehicle styling on the loudness of acceleration sounds was investigated. A series of images of luxury or sporty vehicles was presented to the participants as acceleration sounds were being replayed. The results indicated that participants who were frequent drivers felt that the sound associated with luxury vehicles was louder than that associated with sporty vehicles. However, participants who rarely drove perceived almost no difference between the loudness of the two vehicles types. Thus, the loudness was shown to depend on both the participants’ impression of the vehicle and their driving frequency.
Estimation of pressure-particle velocity impedance measurement uncertainty using the Monte Carlo method
Authors: Brandão Eric , Flesch Rodolfo C. C. , Lenzi Arcanjo , Flesch Carlos A.
Published: July 2011

The pressure-particle velocity (PU) impedance measurement technique is an experimental method used to measure the surface impedance and the absorption coefficient of acoustic samples in situ or under free-field conditions. In this paper, the measurement uncertainty of the the absorption coefficient determined using the PU technique is explored applying the Monte Carlo method. It is shown that because of the uncertainty, it is particularly difficult to measure samples with low absorption and that difficulties associated with the localization of the acoustic centers of the sound source and the PU sensor affect the quality of the measurement roughly to the same extent as the errors in the transfer function between pressure and particle velocity do.
Gatekeepers of Science and Society
Authors: Mistry Helena , Toppin Philip
Published: July 2011

Cells and society rely on information gatekeepers to identify problems and direct an appropriate response.
Twists and Turns in Developing Tubes
Authors: VanHook Annalisa M.
Published: July 2011

Cell shape asymmetries and oriented cell divisions shape epithelial tubes during morphogenesis.
Orphan GPCRs, R-Spondins, and Wnt Signaling
Authors: Gough Nancy R.
Published: July 2011

R-spondins bind to the orphan GPCRs LGR4 and LGR5 to potentiate Wnt-β-catenin signaling.
Introducing Bacterial Electrophysiology
Authors: Hurtley Stella M.
Published: July 2011

An optical bioprobe reveals action potential–like electrical spikes in individual bacteria.
Defending Male Fertility
Authors: Rozen Steve
Published: July 2011

Evidence from functional studies and human genetics shows that a common variant in the
DEFB126
gene leads to reduced male fertility.
Structural Analysis and Direct Imaging of Rotational Stacking Faults in Few-Layer Graphene Synthesized from Solid Botanical Precursor
Authors: Kalita Golap , Wakita Koichi , Umeno Masayoshi
Published: July 2011

Here, we report the structural analysis and rotational stacking faults of few-layer graphene sheets derived by the controlled pyrolysis of the solid botanical derivative camphor (C10H16O). The second-order Raman spectra of the sheets show that the graphene layers are more than one single layer, and the numbers of layers can be controlled by adjusting the amount of camphor pyrolyzed. Transmission electron microscopy images show a minimum of 3 layers for thinner graphene sheets and a maximum of 12 layers for thicker graphene sheets. Low-voltage aberration-corrected high-resolution transmission electron microscopy is also carried out to gain insight into the hexagonal structure and stacking of graphene layers. The transmission electron microscopy study showed the presence of moiré patterns with a relative rotation between graphene layers.
Effect of “Mexican Hat” on Graphene Bilayer Field-Effect Transistor Characteristics
Authors: Svintsov Dmitry , Vyurkov Vladimir , Ryzhii Victor , Otsuji Taiichi
Published: July 2011

Ballistic model of a graphene bilayer field-effect transistor (GBL FET) was developed. It incorporates the exact graphene bilayer electronic spectrum reminding a “Mexican hat”. The isotropic minimum shifted from the center of a band results in a conductance step at low temperature which was so far known for one-dimensional conductors due to conductance quantization. At room temperature a GBL FET exhibits an extremely high transconductance in ON-state. It makes a GBL FET promising for high-frequency analog circuits. We also point out to possibility of electron localization inside the channel on the top of potential barrier.
Terahertz Amplifiers based on Multiple Graphene Layer with Field-Enhancement Effect
Authors: Takatsuka Yuya , Sano Eiichi , Ryzhii Victor , Otsuji Taiichi
Published: July 2011

Terahertz (THz) devices have been developed over the last decade to utilize THz waves for non-destructive sensing and high-speed wireless communications. Ryzhii et al. theoretically demonstrated the feasibility of THz lasing in optically pumped multiple graphene layer (MGL) structures and proposed THz laser structures [V. Ryzhii et al.: J. Appl. Phys. 106 (2009) 084507]. In addition, metallic sheets perforated with a periodic array of holes (metal mesh) have been used for band-pass filters with resonant transmittance of unity. In these periodic structures, induced surface plasmon polaritons (SPPs) enhance the electric field near the holes. We investigated THz amplifiers composed of MGL and metal mesh structures using finite difference time domain (FDTD) electromagnetic simulation. A remarkable increase in the transmittance for the metal mesh structure with MGL was observed.
Towards Graphene GHz/THz Nanosensor
Authors: Mahjoub Akram M. , Motooka Shoutaro , Aoki Nobuyuki , Song Jungwoo , Bird Jonathan P. , Kawano Yukio , Ferry David K. , Ishibashi Koji , Ochiai Yuichi
Published: July 2011

A quantum dot (QD) sensing device, fabricated from nanoscaled carbon material has been studied using of a bilayer graphene field effect transistor in order to enable its application to the detection of microwave (GHz) and/or terahertz (THz) radiation. Recently, it has been found that there exist several common features in low temperature quantum transport, found in experimental results of conductance quantization in a semiconductor QDs and the magnetoresistance of a graphene QDs. The applicability of a graphene field effect transistor at the GHz/THz range is discussed in terms of the microwave transconductance characteristics up to 40 GHz.
High-Density Poly(methyl methacrylate) Brushes as Anchoring Surfaces of Nematic Liquid Crystals
Authors: Tokita Masatoshi , Sato Osamu , Inagaki Yusuke , Nomura Akihiro , Tsujii Yoshinobu , Kang Sungmin , Fukuda Takeshi , Watanabe Junji
Published: July 2011

The orientation of a nematic liquid crystal (LC) on high-density poly(methyl methacrylate) (PMMA) brushes was examined. The nematic LC was injected into the cell consisting of two substrates on which PMMA chains were grafted with a density of 0.299 chains nm-2. It showed degenerate planar orientation, which became uniform on cooling from 120 °C at a magnetic field of 1 T. At ambient temperature, the aligned LC cell showed typical electro-optical properties when driven in the in-plane switching (IPS) mode, indicating that the LC molecules anchored to the brushes with the director parallel to the magnetic field direction. In contrast, at temperatures higher than 65 °C, the transmittance of the cell was time-dependent when driven over a prolonged period, suggesting that the anchoring direction rotated toward the electric field direction. Such temperature-dependent anchoring of the LC can be associated with the viscoelasticity of the PMMA brushes.
Variation in the Absolute Photonic Band Gap of Rods Ranging from Square to Octagonal in Square Lattices
Authors: Hu Chung-An , Chang Kuo-Pin , Yang Su-Lin , Shen Lin Fang , Wu Jin-Jei , Yang Tzong-Jer
Published: July 2011

The band structures and field patterns of dielectric rods in square lattices are calculated using the plane-wave method. The rods with various cross-sectional shapes from square to octagonal at a fixed filling-factor are constructed to assess the geometry effect of photonic crystals to their band gap properties. Analytical results indicate that the corner profiles of rods significantly affect the E- and H-polarization bands in resonance frequency and field distribution. The absolute photonic band gap is closed in the square lattice when square dielectric rods are replaced with octagonal dielectric rods.
Optical Properties of Staggered InGaN/InGaN/GaN Quantum-Well Structures with Ga- and N-Faces
Authors: Park Seoung-Hwan , Ahn Doyeol , Park Jongwoon , Lee Yong-Tak
Published: July 2011

Optical properties of staggered InGaN/InGaN/GaN quantum-well (QW) light-emitting diodes with Ga- and N-faces were investigated using the multiband effective mass theory. The staggered QW structure shows that the carrier density dependence of the transition wavelength is largely reduced compared to the conventional QW structure. On the other hand, the heavy-hole effective mass around the topmost valence band is almost unaffected by the polarity. The N-face staggered InGaN/InGaN/GaN QW structure has a greater spontaneous emission peak than the Ga-face staggered InGaN/InGaN/GaN QW structure because the former has a larger matrix element than the latter. We expect the N-face staggered InGaN/InGaN/GaN QW structure to have improved characteristics compared with the Ga-face staggered InGaN/InGaN/GaN QW structure.
Asymmetric Electrical Properties of Half Corbino Hydrogenated Amorphous Silicon Thin-Film Transistor and Its Applications to Flat Panel Displays
Authors: Lee Hojin , Liu Che-Hung , Kanicki Jerzy
Published: July 2011

The half-Corbino hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) were fabricated with a five-photomask process used in the processing of the active matrix liquid-crystal displays (AM-LCD). We showed that the a-Si:H half-Corbino TFTs have the asymmetric electrical characteristics under different drain-bias conditions. In comparison to half-Corbino TFT with unpatterned gate electrode, the device parasitic capacitance can be significantly reduced by patterning the gate electrode for same device dimension, while the sub-threshold swing and threshold voltage remain identical for same bias condition. The OFF-current remains below 0.1 pA for all device configurations. Finally, we discuss their potential applications as a driving or switching TFT to various flat panel displays.
Optimum Thickness of Al2O3Support Layer for Growth of Singlewalled Carbon Nanotubes
Authors: Kim Soo Youn , Song Wooseok , Kim Minkook , Jeon Cheolho , Jung Woosung , Choi Won Chel , Park Chong-Yun
Published: July 2011

An optimum thickness of Al2O3support layer (ASL) for growth of singlewalled carbon nanotubes (SWCNTs) was systematically established. Atomic force microscopy and scanning electron microscopy results clearly revealed that increasing ASL thickness (tASL) resulted in increased ASL grain diameter and root mean square roughness. This significantly affected the diameters of CNTs through the restricted formation of Fe nanoparticles. As a result, SWCNTs and multiwalled CNTs were simultaneously synthesized using ASLs withtASL= 5, 50, and 100 nm, which were confirmed using Raman spectroscopy and transmission electron microscopy. In contrast, ASLs withtASL= 10–30 nm, were suitable for predominant growth of SWCNTs, and ASL withtASL= 15 nm was especially effective for growing high-quality SWCNTs with a small diameter and narrow distribution, 1.1±0.15 nm.
Modulating the Residual Stress of Ion-Assisted TiO2Films during Annealing with Film Thickness and Substrate Temperature
Authors: Chen Hsi-Chao , Huang Chen-Yu
Published: July 2011

Titanium dioxide (TiO2) films were prepared using ion-beam-assisted deposition on glass substrates with different film thicknesses and substrate temperatures. The effects of thermal annealing temperatures ranging from 100 to 300 °C on the residual stress of these films were investigated. The residual stress in the as-deposited films can be changed from compression to tension stress simply by increasing film thickness when the substrate temperatures are 150 °C. However, the residual stress in the as-deposited films can vary from tension to compression stress by increasing the substrate temperature when the film thickness was 600 nm. The residual stress, optical properties, and X-ray diffraction were investigated for TiO2films during thermal annealing. The residual stress was gradient distribution in the film along the depth direction from the surface to the substrate. An annealing temperature of 200 °C is the key temperature when the TiO2thin films will have the lowest residual stresses and highest refractive indices. However, the deposition only modulated the proper conditions of film thickness, substrate temperature, and annealing temperature to obtain the low residual stress and high refractive index for the TiO2films.
Improved Output Power of GaN-Based Vertical Light Emitting Diodes Fabricated with Current Blocking Region Formed by O2Plasma Treatment
Authors: Lee Sang Youl , Choi Kwang Ki , Jeong Hwan Hee , Kim Eun Joo , Son Hyo Kun , Son Sung Jin , Song June O , Seong Tae-Yeon
Published: July 2011

We report on the formation of current blocking regions by O2plasma treatment to reduce current crowding at the active region above the p-type electrodes of GaN-based vertical light emitting diodes (LEDs). The forward voltage and reverse current (at -5 V) of the plasma-treated LEDs slightly increase with increasing aging time. The output power (at 350 mA) of the plasma-treated LEDs is enhanced by 26% as compared to that of reference LEDs and is comparable to that of LEDs with SiO2current blocking layers. It is shown that the output power (at 700 mA) of the plasma-treated LEDs is degraded by less than 2% of the initial value after 500 h.
Van der Pol-Type Self-Excited Microcantilever Probe for Atomic Force Microscopy
Authors: Yabuno Hiroshi , Kuroda Masaharu , Someya Takashi , Nishimura Kentaro , Hayashi Keiichi , Ashida Kiwamu
Published: July 2011

A control method is proposed in order to reduce the steady-state amplitude of a self-excited cantilever probe in atomic force microscopy. The control method induces van der Pol oscillation by applying both linear and nonlinear feedback. Oscillation of the controlled cantilever cannot easily be stopped, even with the modulation of the viscous damping effect in the measurement environment, because the self-excited oscillation is produced far from the Hopf bifurcation point by high-gain linear feedback. Also, high-gain nonlinear feedback realizes a low steady-state amplitude to enable noncontact measurement. Finally, the feasibility of the practical application of a van der Pol-type self-excited microcantilever probe to nanoscale imaging is examined.
Highly Stable Spatio-Temporal Mechanical Characterization of Nanocontact between Sharp Tips Using Electrostatic Microactuator inside Transmission Electron Microscope
Authors: Ishida Tadashi , Sato Takaaki , Nabeya Shinsuke , Kakushima Kuniyuki , Fujita Hiroyuki
Published: July 2011

A microelectromechanical systems-in-transmission electron microscope (MEMS-in-TEM) setup was established to characterize mechanical properties of a nanostructure captured or generated between tips, while observing its shape and deformation. This setup achieved a stable actuation for several tens of minutes with sub-nm accuracy, and a precise TEM observation of 0.2 nm in spatial resolution. The displacements of a tip-moving actuator with and without the nanostructure were measured from TEM images; the difference between them indicates a force applied to the nanostructure. The force was obtained by multiplying the displacement difference with a spring constant of supporting beams of the tip. Here, we performed an approach-formation-retraction-fracture experiment of a gold nanocontact between tips under TEM observation over 10 min at the actuation speed of 0.1 nm/s. The force during the retraction-fracture process was measured. The maximum force was 66 nN due to the work hardening by the existence of dislocations. This setup will be a powerful tool to examine the role of atomic scale structure for the mechanical characteristics and the extremely-low-speed kinetics.