bluuebunny/crossref_metadata_2025 huggingface dataset:
A SiGe injection‐locked‐oscillator using HBT injector operated in saturation region
Authors: Liu Cheng‐Chen , Wang Cheng‐Cih , Jang Sheng‐Lyang , Juang Miin‐Horng
Published: February 2011

This letter proposes a wide‐locking range injection‐locked frequency oscillator (ILO) fabricated in the 0.35 μm SiGe 3P3M BiCMOS technology. The divider consists of a hetero‐junction bipolar transistor (HBT) cross‐coupled LC oscillator and two injection HBTs in series with the cross‐coupled HBTs. The HBT injectors and coupling transformers are regarded a voltage‐to‐voltage convection device to supply injection voltage to one port of mixer's input. At the supply voltage of 1.2 V, the free‐running frequency is from 6.8 to 7.43 GHz, the current and power consumption of the divider without buffers are 9.4 mA and 11.28 mW, respectively. At the incident power of 0 dBm, the total operational locking range of the ILO used as a divide‐by‐3 frequency divider is from the incident frequency 20.3 to 23.1 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:734–737, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25821
Miniature bandpass filter with wide stopband using open‐loop resonators
Authors: Feng Li‐Ying , Zheng Hong‐Xing , Sun Cheng‐Guang , Gao Feng‐You
Published: February 2011

To reduce the size and improve the performance, a miniature microstrip bandpass filter (BPF) is investigated in this article. On the basis of open‐loops, an interdigital capacitive load has been connected. The new design has advantages of a compact size and a large ratio of the first spurious resonant frequency to the fundamental frequency. A fabricated microstrip BPF has been validated design, and experiment results are shown in very good agreement with expectation. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:748–751, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25829
Prediction of glucose concentration based on probe wavelengths leading to a high correlation
Authors: Lim Seong‐Su , Son Geun‐Sik , Park Chang‐Hyun , Lee Sang‐Shin
Published: February 2011

A prediction scheme of the glucose level involving a set of probe wavelengths belonging to the visible and infrared bands is proposed and verified. These discrete wavelengths were selected because the correlation between the glucose level and the optical reflection or transmission for an aqueous glucose solution was sufficiently high. The glucose level was predicted by means of the partial least squares algorithm. The standard error of calibration and the standard error of prediction were tested to assess the proposed method. The demonstrated standard errors of prediction for the cases involving the reflection response for a set of probe wavelengths (410, 550, 780, 950, and 960 nm) and the transmission response for another set of probe wavelengths (960, 1060, 1150, 1330, 1630 nm) were 2.8 and 1.5, respectively, which were approximately comparable to those of the conventional case resorting to a continuous wide spectral band. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:719–723, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25830
Simple two‐strip monopole with a parasitic shorted strip for internal eight‐band LTE/WWAN laptop computer antenna
Authors: Kang Ting‐Wei , Wong Kin‐Lu
Published: February 2011

A dual‐wideband internal antenna formed by a simple two‐strip monopole (a longer strip and a shorter strip) and a parasitic shorted strip for eight‐band long tern evolution/wireless wide area network operation (698–960/1710–2690 MHz) in the laptop computer is presented.The parasitic shorted strip is excited capacitively by the shorter strip of the two‐strip monopole and contributes two resonant modes to the antenna, with one in the lower band and one in the upper band, thereby effectively widening the bandwidths of the antenna's two operating bands. Further, the parasitic strip short‐circuited to the top shielding metal wall of the display ground in the laptop computer is configured such that its end section with the shorting point is positioned at the side edge of the antenna. This configuration allows the antenna to be placed closely to a nearby grounded plate, with very small effects on the performances of the antenna. This is an advantage for the proposed antenna in practical applications since the antenna requires a very small isolation distance at its side edge to nearby metal objects (such as a metal screw at the top shielding metal wall to fix the display ground to the casing of the laptop computer). Hence, in addition to the small antenna volume of 4 × 12 × 70 mm3 at the top shielding metal wall, compact integration of the proposed antenna along the shielding metal wall of the display ground can also be obtained. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:706–712, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25836
Compact epsilon negative zeroth‐order resonator antenna with higher radiation efficiency
Authors: Huang Jian‐Quan , Chu Qing‐Xin
Published: February 2011

A novel zeroth‐order resonator (ZOR) antenna is presented, which comprises one unit cell of epsilon negative (ENG) structure.Its Q‐factor is decreased by introducing a series capacitor to the shunt branch of the unit cell and reducing the shunt capacitive effect of the ENG structure as well, thus higher radiation efficiency is obtained with very small size of only 9.8 mm × 14.75 mm (0.058λ0 × 0.087λ0 at 1.78 GHz). A prototype is fabricated and measured, and the experimental results show that the novel ZOR antenna can achieve a bandwidth of 25 MHz, monopole‐like radiation pattern, gain of 1.30 dBi, and efficiency up to 78%. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:897–900, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25857
Design and optimization of dual‐band Yagi‐Uda antenna for wireless communications
Authors: Xin Qi , Zhang Fu‐Shun , Sun Bao‐Hua , Zou Yan‐Lin , Liu Qi‐Zhong
Published: February 2011

A novel branch structure is proposed and optimized to design a Yagi‐Uda antenna with dual‐band (915–935 MHz and 1760–1805 MHz) performance. In the design, some parametric studies and computational experiments are made to investigate the variation of performance with some of the key parameters. The proposed antenna is optimized by using multiobjective differential evolution algorithm to obtain required performances of voltage standing wave ratio (VSWR), gain and front‐to‐back ratio (FBR) in the two bands. Prototype with optimal dimension is manufactured and measured, and the results are in good agreement with the simulated ones. In the two operating bands, the proposed antenna achieves directional radiation and the performances that VSWR < 2, gain 4.9–7.6 dBi and FBR 9.8–17.3 dB, making it suitable for the nonfixed base station backhaul in wireless communications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:892–896, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25858
Size‐independent zeroth order electric plasmonic cavity resonator
Authors: Couture S. , Parsa A. , Caloz C.
Published: February 2011

A size‐independent rectangular resonator supporting a mode with a uniform electromagnetic field is presented. This resonator uses a 2D array of metallic wires emulating an effective medium with zero permittivity at the resonance frequency. The field expressions for the resonator are derived and simulation results are presented and discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:927–932, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25864
Compact wide‐band millimeter‐wave LTCC filter using trapezoidal resonator with fractal‐shaped defection
Authors: Xiangjun Zhang , Xiaoping Ma
Published: February 2011

This article presents multilayer low temperature cofired ceramic (LTCC) millimeter wave filters using trapezoidal resonator with fractal‐shaped defection.Operation principle of the resonators is given in detail. The resonators exhibit good electrical performances, compact dimensions and high integration in multilayer dielectric. The LTCC filters implemented in a stripline configuration have a volume of 4.5 × 2.5 × 0.6 mm3. The performance of the filter is simulated by full‐wave electromagnetic simulator‐Ansoft HFSS. The proposed filter is fabricated on six layers of a 100‐μm LTCC substrate. A fabricated prototype bandpass filter achieves a center frequency of 34.7 GHz, a bandwidth of 26.3%, and an insertion loss of 3 dB that includes input and output transitions, the experimental and simulation results closely correspond to each other. The superior features of the proposed filter make it suitable for use in millimeter wave communication systems and other applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:890–892, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25865
Compact hybrid CPW‐FED slot antenna array with pattern diversity
Authors: Li Yue , Zhang Zhijun , Feng Zhenghe
Published: February 2011

In this paper, a compact hybrid coplanar waveguide (CPW) fed 1 × 2 slot antenna array with radiation pattern diversity is proposed for the wireless local area networks (WLAN) application.The antenna array consists of two rectangular slot radiation elements, two feed slots, a CPW and an open‐ended strip. The feed network provides out‐phase and in‐phase feed with high isolation in a relatively compact structure without any lossy circuits, and difference and sum radiation patterns are achieved in the azimuth plane with wide bandwidths of 480 MHz (20%) and 580 MHz (24.2%). The measured gains of dual‐pattern are better than 4.93 and 3.76 dBi in the WLAN band (2.4–2.484 GHz). The proposed dual‐port array can be used as pattern diversity in modern mobile system. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:884–888, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25879
A reflection‐type phase shifter controlled by a piezoelectric transducer
Authors: Kim Chan Ho , Chang Kai
Published: February 2011

A tunable reflection‐type phase shifter, which consists of a quadrature coupler and a piezoelectric transducer (PET), is presented. The proposed phase shifter shows double phase shifts of the conventional PET‐controlled phase shifter by calculation. Measured results of the phase shifter show a maximum phase shift of 132° with respect to the unperturbed condition at 9.7 GHz. An insertion loss (S21) and a return loss (S11) are better than 1.85 and 14.2 dB, respectively, and the insertion‐loss variation is within ±0.46 dB at 9.7 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:938–940, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25885
Further validation of the short form versions of the pelvic floor Distress Inventory (PFDI) and pelvic floor impact questionnaire (PFIQ)
Authors: Barber Matthew D. , Chen Zhen , Lukacz Emily , Markland Alayne , Wai Clifford , Brubaker Linda , Nygaard Ingrid , Weidner Alison , Janz Nancy K. , Spino Cathie
Published: February 2011

Aims

To evaluate validity and responsiveness of PFDI and PFIQ short forms across four multi‐center studies and develop conversion formulas between short and long versions.

Methods

1,006 participants in four prospective studies of pelvic floor disorders completed long versions of the PFDI, PFIQ, and SF‐36 (or SF‐12) at baseline and 3 and 12 months after treatment. Responses were used to calculate scores for the short versions. We calculated correlations between scale versions using Pearson's correlation coefficient and compared their relative responsiveness using the standardized response mean.

Results

PFDI and PFIQ short form scale scores demonstrated excellent correlations with long versions and similar responsiveness. Responsiveness was good to excellent for PFDI‐20 urinary and prolapse scales, moderate for PFDI‐20 colorectal scale and each of the PFIQ‐7 scales, and poor for SF‐36 (or SF‐12) summary scores. Conversion formulas demonstrated excellent goodness of fit.

Conclusions

The long and short forms of the PFDI and PFIQ correlate well and have similar overall responsiveness in participants from four different prospective multicenter studies consisting of diverse patient populations with a broad range of pelvic floor disorders. The short forms provide a reliable and valid alternative in situations where reduced response burden is desired. 30:541–546, 2011. © 2011 Wiley‐Liss, Inc.
Analytical methods for heavy metals in herbal medicines
Authors: Yuan Xudong , Chapman Robert L. , Wu Zhiqian
Published: February 2011

Introduction – It is estimated that about 70–80% of the world's population relies on non‐conventional medicine, mainly of herbal origin. However, owing to the nature and sources of herbal medicines, they are sometimes contaminated with toxic heavy metals such as lead, arsenic, mercury and cadmium, which impose serious health risks to consumers. It is critical to analyse source materials for heavy metals in order to ensure that their concentrations meet the related standards or regulations limiting their concentrations in herbal medicines. In this review, different analytical methods for analysis of heavy metals in herbal medicines are discussed.

Objective – To provide a comprehensive review of the current state of the art in analytical methods used to detect heavy metals in herbal medicines.

Methodology – We systematically searched and reviewed the research articles regarding analytical methods for heavy metals in herbal medicine from various databases, such as Medline/PubMed, ScienceDirect, SciFinder, Google Scholar, EBSCO, Gale InfoTrac, Ingenta, Ovid, ProQuest and ISI Web of Knowledge.

Results – In this review, we discuss in detail several commonly used and sensitive analytical techniques, including atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry or mass spectrometry, X‐ray fluorescence spectrometry, high‐performance liquid chromatography, differential pulse polarography, neutron activation analysis and anodic stripping voltammetry. We also provide some application examples of these analytical techniques for heavy metals in herbal medicines. Copyright © 2011 John Wiley & Sons, Ltd.
Development of a Structure for Blast Wave Mitigation
Authors: Kubota Shiro , Saburi Tei , Homae Tomotaka , Wada Yuji , Ogata Yuji , Iida Mitsuaki , Hamashima Hideki , Katoh Katsumi
Published: February 2011

The internal structure of a blast containment container has been developed and examined by experiments involving the explosion of a high explosive. A steel pipe was selected as an effective structure for blast mitigation, because it dramatically reduces the blast wave in the radial direction near the explosion source. To also reduce the blast wave in the axial direction, two types of model structures consisting of a steel pipe as the main part were examined by both high‐speed photography and pressure measurements of the blast waves. A 0.34‐scale internal structure was constructed by combining these structures. To induce a powerful mitigation effect, the internal structure was filled with a shock‐absorbing material. The peak pressures of C4 explosions in free air were obtained on the basis of the published blast wave data for TNT explosions in free air using an equivalent weight of 1.37. The peak pressures of the blast waves from the structures for all cases were compared with the blast wave data for C4 explosions in free air to estimate the blast mitigation effect. As a result it was estimated that the internal structure not only eliminates the blast pressure in the radial direction but also reduces the blast wave in the axial direction by 36 %. By combining the effects of the internal structure and the shock‐absorbing material, the structure can reduce the peak pressure by 75 %.
Structure and dynamics of cationic membrane peptides and proteins: Insights from solid‐state NMR
Authors: Hong Mei , Su Yongchao
Published: February 2011

Many membrane peptides and protein domains contain functionally important cationic Arg and Lys residues, whose insertion into the hydrophobic interior of the lipid bilayer encounters significant energy barriers. To understand how these cationic molecules overcome the free energy barrier to insert into the lipid membrane, we have used solid‐state NMR spectroscopy to determine the membrane‐bound topology of these peptides. A versatile array of solid‐state NMR experiments now readily yields the conformation, dynamics, orientation, depth of insertion, and site‐specific protein–lipid interactions of these molecules. We summarize key findings of several Arg‐rich membrane peptides, including β‐sheet antimicrobial peptides, unstructured cell‐penetrating peptides, and the voltage‐sensing helix of voltage‐gated potassium channels. Our results indicate the central role of guanidinium‐phosphate and guanidinium‐water interactions in dictating the structural topology of these cationic molecules in the lipid membrane, which in turn account for the mechanisms of this functionally diverse class of membrane peptides.
Estimating the dose–toxicity curve in completed phase I studies
Authors: Iasonos Alexia , Ostrovnaya Irina
Published: February 2011

While there is an extensive amount of literature covering prospective designs for phase I trials, the methodology for analyzing these data is limited. Prospective designs select the maximum tolerated dose (MTD) through a dose escalation scheme based on a model or on empirical rules. For example, the ‘3 + 3’ method (standard method: SM) assigns patients in cohorts of three and expands to six if one toxicity is observed. It has been shown previously that the MTD chosen by the SM may be low, possibly leading to a non‐efficacious dose. Additionally, when deviation from the original trial design occurs, the rules for determining MTD might not be applicable. We hypothesize that a retrospective analysis would suggest an MTD that is more accurate than the one obtained by the SM. A weighted Continual Reassessment Method (CRM‐w) has been suggested (Biometrics 2005; 61:749–756) for analyzing data obtained from designs other than the prospective Continual Reassessment Method (CRM). However, CRM‐w has not been evaluated in trials that follow the SM design. In this study, we propose a method to analyze completed phase I trials and possibly confirm or amend the recommended phase II dose, based on a constrained maximum likelihood estimation (CMLE). A comparison of CRM‐w, isotonic regression, and CMLE in analyzing simulated SM trials shows that CMLE more accurately selects the true MTD than SM, and is better or comparable to isotonic regression and CRM‐w. Confidence intervals around the toxicity probabilities at each dose level are estimated using the cumulative toxicity data. A programming code is included. Copyright © 2011 John Wiley & Sons, Ltd.
Structural and Electronic Properties of Fluorographene
Authors: Samarakoon Duminda K. , Chen Zhifan , Nicolas Chantel , Wang Xiao‐Qian
Published: February 2011

The structural and electronic characteristics of fluorinated graphene are investigated based on first‐principles density‐functional calculations. A detailed analysis of the energy order for stoichiometric fluorographene membranes indicates that there exists prominent chair and stirrup conformations, which correlate with the experimentally observed in‐plane lattice expansion contrary to a contraction in graphane. The optical response of fluorographene is investigated using the GW–Bethe–Salpeter equation approach. The results are in good conformity with the experimentally observed optical gap and reveal predominant charge‐transfer excitations arising from strong electron–hole interactions. The appearance of bounded excitons in the ultraviolet region can result in an excitonic Bose–Einstein condensate in fluorographene.
Deformation Behaviour and Microstructural Evolution During Hot Compression of AISI 904L
Authors: Bradaskja B. , Pirnar B. , Fazarinc M. , Fajfar P.
Published: February 2011

The hot deformation behaviour and microstructural evolution of AISI 904L super‐austenitic steel has been investigated by means of hot compression tests. The tests were carried out on a Gleeble 1500D thermo‐mechanical simulator in the temperature range from 850 °C to 1150 °C and at strain rates range from 0.001 s−1 to 5 s−1. The microstructure evolution was examined by means of light optical microscopy (LOM). The results show that after an initial deformation hardening, softening mechanisms occur. The peak stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zener–Hollomon parameter in the hyperbolic‐sine equation with the activation energy for deformation of 463 kJ/mol. The steady state was achieved at maximum strain of 0.9 only at the lower strain rates (under 1 s−1) and the higher temperatures (above 1100 °C). Microstructural analyses showed a gradual increase in the dynamically recrystallized area with an increase of the temperature and a decrease of the strain rate. The grain size did change, as expected, correlating to the deformation conditions.
Solubility of Two Disperse Dyes Derived from N‐Alkyl and N‐Carboxylic Acid Naphthalimides in the Presence of Gemini Cationic Surfactants
Authors: Gharanjig K. , Sadeghi‐Kiakhani M. , Tehrani‐Bagha A. R. , Khosravi A. , Menger F. M.
Published: February 2011

The solubility of naphthalimide‐based monoazo dyes containing N‐ethyl and N‐ethanoic acid groups was investigated in the presence of a conventional monomeric counterpart (DTAB) and two cationic gemini surfactants (12‐4‐12 or 14‐4‐14) individually. The effective parameters on dye solubility such as temperature, time and concentration of surfactants were investigated by UV–Visible spectrophotometry. The results demonstrate that the solubility of both dyes was considerably increased at concentrations above the surfactant CMC. The wavelength for the maximum absorbance of dyes in the aqueous solution shifts toward longer wavelengths with changes in the concentration of the cationic surfactants. A kinetic study of solubilization of dyes in cationic surfactants solution showed that the rate of solubilization follows the pseudo‐first‐order reactions. Rates of solubilization were in the range of 0.5 × 10−3 to 6.8 × 10−3 min−1 for both dyes. The disperse dye containing a carboxylic acid group (dye 2) has a higher solubility rate than the dye containing an alkyl group (dye 1). The type of surfactant has a very low effect on adsorption of dye 1 onto the polyester fibers, whereas changing the surfactant type from DTAB to 12‐4‐12 or 14‐4‐14 causes adsorption of dye 2 on polyester to decrease.
Toward a Mobilization Conception of Democratic Representation
Authors: DISCH LISA
Published: February 2011

This article analyzes what I term “the dilemma of democratic competence,” which emerges when researchers find their expectations regarding democratic responsiveness to be in conflict with their findings regarding the context dependency of individual preferences. I attribute this dilemma to scholars' normative expectations, rather than to deficiencies of mass democratic politics. I propose a mobilization conception of political representation and develop a systemic understanding of reflexivity as the measure of its legitimacy. This article thus contributes to the emergent normative argument that political representation is intrinsic to democratic government, and links that claim to empirical research on political preference formation.
Relationships of maternal zinc intake from animal foods with fetal growth
Authors: Lee Yo A. , Hwang Ji-Yun , Kim Hyesook , Ha Eun-Hee , Park Hyesook , Ha Mina , Kim Yangho , Hong Yun-Chul , Chang Namsoo
Published: February 2011

Zn is an essential element for human growth. The nutritional adequacy of dietary Zn depends not only on the total Zn intake, but also on the type of food source (i.e. of plant or animal origin). We investigated the association between maternal dietary Zn intake from animal and plant food sources and fetal growth. A total of 918 pregnant women at 12–28 weeks of gestation were selected from the Mothers and Children's Environmental Health study in Korea. Dietary intakes in mid-pregnancy were estimated by a 24 h recall method, and subsequent birth weight and height were obtained from medical records. Multiple regression analysis showed that maternal Zn intake from animal food sources and their proportions relative to total Zn intake were positively associated with birth weight (P = 0·034 and 0·045, respectively) and height (P = 0·020 and 0·032, respectively). Conversely, the percentage of Zn intake from plant food sources relative to total Zn intake was negatively associated with birth height (P = 0·026) after adjustment for covariates that may affect fetal growth. The molar ratio of phytate:Zn was negatively associated with birth weight (P = 0·037). In conclusion, we found that the absolute amounts of Zn from different food sources (e.g. animal or plant) and their proportions relative to total Zn intake were significantly associated with birth weight and height. A sufficient amount of Zn intake from animal food sources of a relatively higher Zn bioavailability is thus encouraged for women during pregnancy.
An experimental study of the effect of external turbulence on the decay of a single vortex and a vortex pair
Authors: van JAARSVELD J. P. J. , HOLTEN A. P. C. , ELSENAAR A. , TRIELING R. R. , van HEIJST G. J. F.
Published: February 2011

This study is concerned with the effect of external turbulence on the decay of vortices. Single vortices and vortex pairs were generated with wing(s) mounted in the sidewalls of a wind tunnel. The distance between the two vortices could be adjusted such that they just touched each other or overlapped. The intensity of the turbulence could be controlled with a turbulence grid. The development of the vortex was measured at a number of downstream stations with particle image velocimetry for a range of wing settings. The results indicate that the single vortex can be described by the ‘two length scales’ model of Jacquin, Fabre & Geffroy (AIAA, vol. 1038, 2001, p. 1). A vortex core, which decays like a Lamb–Oseen vortex, is embedded in a region with an almost constant radius and a much lower azimuthal velocity that obeys a ~r−β power law, with r being the radius measured from the vortex centre. For the turbulence levels and the test section length used in this study, the single-vortex behaviour is independent of the external turbulence and in contrast with the decay of the vortex pair that strongly depends on the external turbulence. In the initial stages of the vortex pair evolution, the vortices decay due to cancellation of vorticity at the symmetry plane. At a later stage, Crow oscillations are observed, followed by a breakdown of the vortices. This vortex breakdown might be due to direct turbulent action. The observed behaviour is in agreement with the theoretical model of Crow & Bate (J. Aircraft, vol. 13, 1976, p. 476).
Break-away separation for high turbulence intensity and large Reynolds number
Authors: SCHEICHL B. , KLUWICK A. , SMITH F. T.
Published: February 2011

Massive flow separation from the surface of a plane bluff obstacle in an incompressible uniform stream is addressed theoretically for large values of the global Reynolds numberRe. The analysis is motivated by a conclusion drawn from recent theoretical results which is corroborated by experimental findings but apparently contrasts with common reasoning: the attached boundary layer extending from the front stagnation point to the position of separation never attains a fully developed turbulent state, even for arbitrarily largeRe. Consequently, the boundary layer exhibits a certain level of turbulence intensity that is linked with the separation process, governed by local viscous–inviscid interaction. Eventually, the latter mechanism is expected to be associated with rapid change of the separating shear layer towards a fully developed turbulent one. A self-consistent flow description in the vicinity of separation is derived, where the present study includes the predominantly turbulent region. We establish a criterion that acts to select the position of separation. The basic analysis here, which appears physically feasible and rational, is carried out without needing to resort to a specific turbulence closure.
A dynamic multi-scale approach for turbulent inflow boundary conditions in spatially developing flows
Authors: ARAYA GUILLERMO , CASTILLO LUCIANO , MENEVEAU CHARLES , JANSEN KENNETH
Published: February 2011

A dynamic method for prescribing realistic inflow boundary conditions is presented for simulations of spatially developing turbulent boundary layers. The approach is based on the rescaling–recycling method proposed by Lund, Wu & Squires (J. Comput. Phys, vol. 140, 1998, pp. 233–258) and the multi-scale method developed by Araya, Jansen & Castillo (J. Turbul., vol. 10, no. 36, 2009, pp. 1–33). The rescaling process requires prior knowledge about how the velocity and length scales are related between the inlet and recycle stations. Here a dynamic approach is proposed in which such information is deduced dynamically by involving an additional plane, the so-called test plane located between the inlet and recycle stations. The approach distinguishes between the inner and outer regions of the boundary layer and enables the use of multiple velocity scales. This flexibility allows applications to boundary layer flows with pressure gradients and avoids the need to prescribe empirically the friction velocity and other flow parameters at the inlet of the domain. The dynamic method is tested in direct numerical simulations of zero, favourable and adverse pressure gradient flows. The dynamically obtained scaling exponents for the downstream evolution of boundary layer parameters are found to fluctuate in time, but on average they agree with the expected values for zero, favourable and adverse pressure gradient flows. Comparisons of the results with data from experiments, and from other direct numerical simulations that use much longer computational domains to capture laminar-to-turbulence transition, demonstrate the suitability of the proposed dynamic method.
Three-dimensional conditional structure of a high-Reynolds-number turbulent boundary layer
Authors: HUTCHINS N. , MONTY J. P. , GANAPATHISUBRAMANI B. , NG H. C. H. , MARUSIC I.
Published: February 2011

An array of surface hot-film shear-stress sensors together with a traversing hot-wire probe is used to identify the conditional structure associated with a large-scale skin-friction event in a high-Reynolds-number turbulent boundary layer. It is found that the large-scale skin-friction events convect at a velocity that is much faster than the local mean in the near-wall region (the convection velocity for large-scale skin-friction fluctuations is found to be close to the local mean at the midpoint of the logarithmic region). Instantaneous shear-stress data indicate the presence of large-scale structures at the wall that are comparable in scale and arrangement to the superstructure events that have been previously observed to populate the logarithmic regions of turbulent boundary layers. Conditional averages of streamwise velocity computed based on a low skin-friction footprint at the wall offer a wider three-dimensional view of the average superstructure event. These events consist of highly elongated forward-leaning low-speed structures, flanked on either side by high-speed events of similar general form. An analysis of small-scale energy associated with these large-scale events reveals that the small-scale velocity fluctuations are attenuated near the wall and upstream of a low skin-friction event, while downstream and above the low skin-friction event, the fluctuations are significantly amplified. In general, it is observed that the attenuation and amplification of the small-scale energy seems to approximately align with large-scale regions of streamwise acceleration and deceleration, respectively. Further conditional averaging based on streamwise skin-friction gradients confirms this observation. A conditioning scheme to detect the presence of meandering large-scale structures is also proposed. The large-scale meandering events are shown to be a possible source of the strong streamwise velocity gradients, and as such play a significant role in modulating the small-scale motions.
On the microhydrodynamics of superspreading
Authors: MALDARELLI C.
Published: February 2011

Droplets of an aqueous phase placed on a very hydrophobic, waxy surface bead-up rather than spread, forming a sessile drop with a relatively large contact angle at the edge of the drop. Surfactant molecules, when dissolved in the aqueous phase, can facilitate the wetting of an aqueous drop on a hydrophobic surface. One class of surfactants, superwetters, can cause aqueous droplets to move very rapidly over a hydrophobic surface, thereby completely wetting the surface (superspreading). A recent numerical study of the hydrodynamics of superspreading by Karapetsas, Craster & Matar (J. Fluid Mech., this issue, vol. 670, 2011, pp. 5–37) provides a clear explanation of how these surfactants cause such a dramatic change in wetting behaviour. The study shows that large spreading rates occur when the surfactant can transfer directly from the air/aqueous to the aqueous/hydrophobic solid interface at the contact line. This transfer reduces the concentration of surfactant on the fluid interface, which would otherwise be elevated due to the advection accompanying the drop spreading. The reduced concentration creates a Marangoni force along the fluid surface in the direction of spreading, and a concave rim in the vicinity of the contact line with a large dynamic contact angle. Both of these effects act to increase the spreading rate. The molecular structure of the superwetters allows them to assemble on a hydrophobic surface, enabling the direct transfer from the fluid to the solid surface at the contact line.
Influence of internal viscosity on the large deformation and buckling of a spherical capsule in a simple shear flow
Authors: FOESSEL É. , WALTER J. , SALSAC A.-V. , BARTHÈS-BIESEL D.
Published: February 2011

The motion and deformation of a spherical elastic capsule freely suspended in a simple shear flow is studied numerically, focusing on the effect of the internal-to-external viscosity ratio. The three-dimensional fluid–structure interactions are modelled coupling a boundary integral method (for the internal and external fluid motion) with a finite element method (for the membrane deformation). For low viscosity ratios, the internal viscosity affect the capsule deformation. Conversely, for large viscosity ratios, the slowing effect of the internal motion lowers the overall capsule deformation; the deformation is asymptotically independent of the flow strength and membrane behaviour. An important result is that increasing the internal viscosity leads to membrane compression and possibly buckling. Above a critical value of the viscosity ratio, compression zones are found on the capsule membrane for all flow strengths. This shows that very viscous capsules tend to buckle easily.
A randomized, double-blind, placebo-controlled trial on the efficacy and tolerability of sertraline in Iranian veterans with post-traumatic stress disorder
Authors: Panahi Y. , Moghaddam B. Rezazadeh , Sahebkar A. , Nazari M. Abbasi , Beiraghdar F. , Karami G. , Saadat A. R.
Published: February 2011

Background

Unlike civilian post-traumatic stress disorder (PTSD), the efficacy of sertraline for the treatment of combat-related PTSD has not yet been proven. The present study aimed to evaluate the clinical efficacy of sertraline against combat-related PTSD in a randomized, double-blind, placebo-controlled trial.

Method

Seventy Iranian veterans of the Iran–Iraq war who met the DSM-IV criteria for diagnosis of PTSD were randomized to receive either flexibly dosed sertraline (50–200 mg/day) (n=35, completers=32) or placebo (n=35, completers=30) for 10 weeks. Efficacy was evaluated by the Impact of Event Scale – Revised (IES-R) and the Clinical Global Impression scale – Severity (CGI-S) and Improvement (CGI-I) ratings. Responder criteria were defined as a ⩾30% reduction in the IES-R total score plus a CGI-I rating of ‘much’ or ‘very much’ improved.

Results

On both intention-to-treat (ITT) and per protocol (completer) methods of analysis, the mean reductions in the IES-R total and subscale (re-experiencing/intrusion, avoidance/numbing and hyperarousal) scores (p<0.001) and also in the CGI-S score (p<0.01) were significantly greater in the sertraline group than in the placebo group. For the CGI-I, the mean endpoint score was significantly lower in the sertraline group than in the placebo group (p⩽0.001). The number of responders in the sertraline group was significantly higher than in the placebo group (44% v. 3%, p⩽0.001). Sertraline was well tolerated, with a 6% discontinuation rate as a result of adverse reactions.

Conclusions

The results of this study suggest that sertraline can be an effective, safe and tolerable treatment for combat-related PTSD in Iranian veterans.
Meanings of television in older adults' lives: an analysis of change and continuity in television viewing
Authors: VAN DER GOOT MARGOT , BEENTJES JOHANNES W. J. , VAN SELM MARTINE
Published: February 2011

Television viewing is an important leisure activity for older adults. The aim of the current study is to provide insight into the meanings of television in older adults' lives, by analysing change and continuity in their television viewing. A qualitative study was conducted that included in-depth interviews on television viewing among a diverse sample of Dutch people aged 65 years and older (N=86). The interview study shows that television has a variety of meanings for older adults. The meanings of television viewing changed in response to changes in everyday life, but this did not happen unidirectionally. Retirement, physical changes and changes in household composition led to increases as well as decreases in television viewing. Watching more television was experienced in both positive and negative ways. After a loss in the interpersonal sphere, television viewing can play a valuable role in adaptation processes, but it was also experienced as an activity that needs to be avoided. With regard to television content we found that some programmes gained importance when people age, whereas other programmes became less important or attractive. These changes in television viewing occurred for only part of the sample and some interviewees experienced continuity in the status of viewing and in their content preferences. The results are discussed in the context of recent literature on leisure constraints, leisure as coping, and adaptation strategies.
Perceptions of trends in Seychelles artisanal trap fisheries: comparing catch monitoring, underwater visual census and fishers' knowledge
Authors: DAW TIM M. , ROBINSON JAN , GRAHAM NICHOLAS A. J.
Published: February 2011

Fisheries scientists and managers are increasingly engaging with fishers’ knowledge (FK) to provide novel information and improve the legitimacy of fisheries governance. Disputes between the perceptions of fishers and scientists can generate conflicts for governance, but can also be a source of new perspectives or understandings. This paper compares artisanal trap fishers’ reported current catch rates with landings data and underwater visual census (UVC). Fishers’ reports of contemporary ‘normal’ catch per day tended to be higher than recent median landings records. However, fishers’ reports of ‘normal’ catch per trap were not significantly different from the median CPUE calculated from landings data, and reports of ‘good’ and ‘poor’ catch rates were indicative of variability observed in landings data. FK, landings and UVC data all gave different perspectives of trends over a ten-year period. Fishers’ perceptions indicated greater declines than statistical models fitted to landings data, while UVC evidence for trends varied between sites and according to the fish assemblage considered. Divergence in trend perceptions may have resulted from differences in the spatial, temporal or taxonomic focus of each dataset. Fishers may have experienced and understood behavioural changes and increased fishing power, which may have obscured declines from landings data. Various psychological factors affect memory and recall, and may have affected these memory-based estimates of trends, while different assumptions underlying the analysis of both interview data and conventional scientific data could also have led to qualitatively different trend perceptions. Differing perspectives from these three data sources illustrate both the potential for ‘cognitive conflicts’ between stakeholders who do not rely on the same data sources, as well as the importance of multiple information sources to understand dynamics of fisheries. Collaborative investigation of such divergence may facilitate learning and improve fisheries governance.
Effectiveness of the geriatric day hospital – a realist review
Authors: Gunawardena Indunil
Published: February 2011

This research paper is a realist review on the effectiveness of medical care for older people in the geriatric day hospital (GDH), based on trial data from a Cochrane review published in 2008. The Cochrane review indicated no overall difference between GDH care and alternative services. However, health care management and policy interventions are quite complex and methodologically more diverse than clinical treatments. Hence a ‘realist review’ is a more suitable explanatory analysis, aimed at discerning what works for whom, in what circumstances, in what respect, and how. This realist review on GDH care provides an explanatory analysis and has aimed to identify where GDH care is and is not effective.
An overview of surgical interventions for the treatment of urinary incontinence
Authors: Maguire T , Tincello DG , Mistri A
Published: February 2011

Urinary incontinence remains a topic that both patients and clinicians find difficult to discuss and manage. Following the NICE guidance published in 2006, a well-defined structure for the management of urinary problems was outlined. Conservative measures are the mainstay for all patients, with anticholinergic drugs playing a major role in the management of over-active bladder and urge incontinence.

Surgical management is an area that continues to grow and develop. The types of procedures offered to patients have changed dramatically in the last 10–15 years, with the advent of tension-free vaginal tapes and more recently the use of botulinum toxin. It is important that health professionals encountering patients with incontinence are aware of the common urological/gynaecological operations available, the place of surgical options in the overall pathway, and the benefits as well as the risks associated with continence surgery. This article provides the non-specialist with an overview of the available surgical options for management of continence.
The Implementation of Computerized Cognitive Behavioural Therapies in a Service User-Led, Third Sector Self Help Clinic
Authors: Cavanagh Kate , Seccombe Nick , Lidbetter Nicky
Published: February 2011

Background and aims:The efficacy and effectiveness of a computerized cognitive behavioural therapy (CCBT) package,Beating the Blues, has been demonstrated in a large randomized controlled trial and several pragmatic studies in the National Health Service (NHS). The current study tests the generalizability of this finding to the implementation of CCBT in a service user-led, third sector Self Help Clinic.Method:510 referrals for theBeating the Bluesprogram were received over a 16 month period in routine care. The Patient Health Questionnaire Depression (PHQ-9) and Anxiety (GAD-7) Scales were administered pre-treatment and during each treatment session. The 10-item Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM), Work and Social Adjustment Scale and Patient Experience Questionnaire were also administered pre-treatment and immediately on completing treatment.Results:More than two-thirds of referrals were suitable for treatment and completed a baseline assessment; 84% of these started theBeating the Bluesprogram. Two-hundred and twenty-six people meeting caseness criteria at baseline completed at least two sessions of CCBT. Of these, 50% met recovery criteria at their final point of measurement. Completer and intention-to-treat analysis also demonstrated statistically and clinically significant improvements on key outcome measures.Conclusion:CCBT can be effectively implemented in a service user-led, third sector Self Help Clinic, increasing access to psychological therapies to meet local needs for tier two interventions for depression and anxiety.
Assessing factorial and convergent validity and reliability of a food behaviour checklist for Spanish-speaking participants in US Department of Agriculture nutrition education programmes
Authors: Banna Jinan C , Townsend Marilyn S
Published: February 2011

Objective

To assess convergent validity, factorial validity, test–retest reliability and internal consistency of a diet quality food behaviour checklist (FBC) for low-literate, low-income Spanish speakers.

Design

Participants (n90) completed three dietary recalls, the Spanish-language version of the US Department of Agriculture (USDA) Household Food Security Survey Module (HFSSM) and the Spanish-language FBC. Factor structure was examined using principal component analysis. Spearman correlation coefficients between FBC item responses and nutrient intakes from 24 h recalls were used to estimate convergent validity. Correlation coefficients were also calculated between FBC item responses at two time points in another group of participants (n71) to examine test–retest reliability. Cronbach'sαcoefficient was determined for items within each sub-scale.

Setting

Non-profit community agencies serving low-income clients, migrant farm worker camps and low-income housing sites in four California counties.

Subjects

Spanish-speaking women (n161) who met income eligibility for the SNAP-Ed (Supplemental Nutrition Assistance Program–Education).

Results

Factor analysis resulted in six sub-scales. Responses to nineteen food behaviour items were significantly correlated with hypothesized 24 h recall data (with a maximum correlation of 0·44 for drinking milk and calcium) or the USDA HFSSM (0·42 with the food security item). Coefficients for test–retest reliability ranged from 0·35 to 0·79. Cronbach'sαranged from 0·49 for the diet quality sub-scale to 0·80 for the fruit and vegetable sub-scale.

Conclusions

The twenty-two-item FBC and instruction guide will be used to evaluate USDA community nutrition education interventions with low-literate Spanish speakers. This research contributes to the body of knowledge about this at-risk population in California.
Introduction to the 24th international conference on logic programming special issue
Authors: DE LA BANDA MARIA GARCIA , PONTELLI ENRICO
Published: February 2011

The ICLP series of conferences provides a technical forum for presenting and disseminating innovative research in the field of logic programming. The 24th International Conference on Logic Programming took place from December 9–13, 2008 in the city of Udine, Italy. The conference attracted 177 submissions and featured a high-quality program focused on the foundations, developments, and applications of logic programming. Of particular significance was the special session celebrating the 20th anniversary of the seminal paper on the stable model semantics.