bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization to reduce EDFA gain fluctuations for optical packet buffering
Authors: Thomas Djeisson Hoffmann , von der Weid Jean Pierre
Published: July 2007

In wavelength division multiplexing networks it is necessary to buffer incoming packets to resolve the contentions in any network node. We optimized the performance of an all‐optical ring‐laser gain‐clamped erbium‐doped fiber amplifier working in a delay line to store packets for a time as long as 2 ms with power penalty as small as 0.3 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2523–2526, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22741
Semiempirical model for admittance and scattering parameters of GaN MESFET for microwave circuit applications
Authors: Kabra Sneha , Kaur Harsupreet , Haldar Subhasis , Gupta Mridula , Gupta R. S.
Published: July 2007

A semiempirical model of GaN MESFET to evaluate admittance parameters, scattering parameters, maximum unilateral transducer power gain, and maximum stable gain is presented. Frequency dependence of the parasitic capacitances obtained by simulations has been utilized to develop the model. Results have been verified using ATLAS 2D device simulator and are also compared with parasitic element‐dependent model. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2446–2450, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22744
A diamond‐like vertical monopole antenna for ultra‐wideband communication
Authors: Khan Salman Naeem , Ti Ling , Hu Jun , He Sailing
Published: July 2007

A diamond monopole (DM) antenna is proposed for ultra‐wideband (UWB) communication. The impedance bandwidth is improved by cutting the two opposite vertexes of a square. The design parameters are analyzed and optimized to obtain a good performance. Comparison between the proposed DM and a conventional circular disk monopole (CDM) is also given. The proposed UWB antenna has advantages over a CDM in (for example) small size and omnidirectivity. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2443–2446, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22745
An efficient EYDFA with a 54 dB small signal gain
Authors: Muhd‐Yassin S. Z. , Harun S. W. , Abdul‐Rashid H. A. , Abd‐Rahman M. K. , Rahman F. Abd , Ahmad H.
Published: July 2007

An efficient erbium/ytterbium codoped fiber amplifier is demonstrated by using a dual‐stage configuration with a midway optical isolator and a band‐pass filter (BPF). The amplifier achieved a maximum low signal gain of 54 dB and a corresponding noise figure of 6.5 dB (1536 nm) using the input signal power and total pump power of −50 dBm and 140 mW, respectively. The gain obtained by the amplifier was about 12.5 dB higher than the gain of a conventional single‐stage amplifier whereas its noise figure was 3.5 dB lower. Both isolator and BPF contribute to gain and noise figure improvements by blocking backward and forward propagating amplified spontaneous emission. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2337–2339, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22750
Non surgical life saving diagnostic procedure using microwaves
Authors: Lonappan Anil , Thomas Vinu , Bindu G. , Jacob Joe , Rajasekaran C. , Mathew K. T.
Published: July 2007

The physiological changes of pregnancy can result in complications in the mother, which in turn may have fetal implications. There is a need to refine the risk stratification of women so that they can receive appropriate obstetrical counseling and care. The present communication presents the analysis of the amniotic fluid which is surrounded by the baby and helps to protect both the baby and the uterus. The in vitro measurements of amniotic fluid samples were carried out by cavity perturbation technique in the frequency range of 2–3 GHz of different samples as a function of gestation weeks and have observed a pronounced change of the conductivity at the end of normal pregnancies and consistent conductivity in complicated pregnancies. This indicates that microwave study is a life saving diagnostic procedure of the mother and baby can take proper care for those having complicated pregnancies. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2364–2368, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22753
Low‐phase noise 3 42 GHz signal generation using high‐order longitudinal modes of a coaxial loop cavity
Authors: Wang Xinyue , Wang Ziyu
Published: July 2007

This article demonstrates a novel coaxial loop cavity microwave/mm‐wave generator. Working at high‐order longitudinal modes, the generator has the single‐sideband phase noise of about −75 and −105 dBc/Hz at 10 and 100 kHz offset over the frequency band of 3–42 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2329–2331, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22754
New analog predistorer using mixing operation for independent control of IM3 components
Authors: Lee Yong‐Sub , Lee Mun‐Woo , Choi Gil‐bok , Jeong Yoon‐Ha
Published: July 2007

This article reports new predistorters using mixing operation. For compensate the memory effect of the power amplifier, the lower and upper third‐order intermodulation components in the PD are controlled independently. From the measured results for a two‐tone signal with 20‐MHz tone spacing, the significant IM3 cancellation over 40 dB is achieved over a whole output power range. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2552–2555, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22758
A low voltage highly linear 24‐GHz down conversion mixer in 0.18‐μm CMOS
Authors: Hossain Masum , Frank Brian M. , Antar Yahia M.
Published: July 2007

A K‐band low voltage, highly linear folded Gilbert cell mixer in 0.18‐μm CMOS is presented. An optimization technique been introduced which is particularly applicable to Gilbert cell type mixers. This technique has been experimentally verified with a down conversion mixer fabricated in a 0.18‐μm CMOS process. Utilizing PMOS devices in the transconductance stage and using a 2‐V supply voltage, the mixer can down convert from 24 GHz to 10 MHz with an input referred third order intercept of +20 dBm and a conversion gain of 2 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2547–2552, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22759
Improvement of antenna isolation in hand‐held devices using miniaturized electromagnetic band‐gap structures
Authors: Mäkinen Riku , Pynttäri Vesa , Heikkinen Jouko , Kivikoski Markku
Published: July 2007

Miniaturized electromagnetic band‐gap (EBG) structures suitable for hand‐held devices at 1.575 and 2.4 GHz frequency bands are presented. To miniaturize the structures, a ceramic substrate with relative permittivity of 82 is used to obtain a period of the order of 2.6–3.5 mm. Simulation results are presented for slotted‐patch and two‐dimensional (2‐D) fork EBGs at 1.575 GHz. Measured results are presented for spiral EBG at 2.4 GHz. Measured data with good isolation and radiation properties validates the concept of proposed EBG structures. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2508–2513, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22761
Small size stepped impedance low pass filters
Authors: Mohra Ashraf S. , Alkanhal Majeed A.
Published: July 2007

A reduction in the overall size of the stepped impedance low pass filter is proposed in this article. The high impedance line sections are converted to T‐sections and the low impedance line sections are converted to π‐sections. Analysis and design equations for such conversions are presented. This method accomplishes a prominent size reduction in sharp response filters with multi‐stepped impedance sections. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2398–2403, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22766
Theory of optical scattering by carbon nanotubes
Authors: Mikki Said M. , Kishk Ahmed A.
Published: July 2007

Here, a theory of optical scattering by single‐wall carbon nanotube using modal expansion of the scattered and transmitted fields is developed. The effective‐boundary condition, derived previously using accurate quantum‐mechanical one‐electron tight‐biding approach, is employed to obtain the unknown coefficients in the series expansion. The complete scattered field is then derived analytically and compared to Rayleigh spectroscopy experiments. Very good agreement with the empirical data is observed. The theory is shown to produce expressions for the dielectric function of carbon nanotubes that can be used for further study of the optical and electronic structure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2360–2364, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22768
Cross‐polarisation tracking errors of a radome covered monopulse radar
Authors: Arpin Frédéric , Ollevier Thomas
Published: July 2007

This paper examines the additional cross‐polarisation tracking errors generated because of the depolarisation effect of an ogive‐shaped radome. A comparison is made between the cross‐polarisation tracking errors of a linearly polarised monopulse radar in the presence and absence of an ogive‐shaped radome. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2354–2360, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22769
A simple dispersion relation of infinitely slotted rectangular waveguide
Authors: Lee Sung U. , Eom Hyo J.
Published: July 2007

A simple, accurate dispersion relation for an infinitely slotted rectangular waveguide is presented by using the mode‐matching technique. Computed results are in agreement with measured data. A solution based on the single‐mode approximation is valid for practical leaky‐wave antenna applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2322–2324, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22770
A 180–196 GHz image‐reject Schottky‐diode MMIC mixer
Authors: Archer John W. , Tello Juan
Published: July 2007

This article describes a novel single‐sideband, Schottky diode integrated circuit mixer. The subharmonically pumped mixer, operating on the 4th local oscillator (LO) harmonic, was developed for use in millimeter‐wave receiver and transmitter applications in the 180–196 GHz band. The gallium arsenide (GaAs) monolithic microwave integrated circuit (MMIC) was fabricated using a standard commercial process. This is the first time a fully integrated, 4th harmonic image reject mixer has been reported in this frequency range. The mixer operates with a fixed pump frequency of 47 GHz (corresponding to an LO of 188 GHz) and pump power level of +18.7 dBm. For RF signals in the range 180–196 GHz, the conversion loss is typically 21 dB over the 1–8 GHz IF corresponding to the desired sideband. Under these conditions, high rejection of the undesired sideband is achieved. The rejection is typically >15 dB, over the same IF frequency range, relative to the desired signal. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2319–2322, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22771
Multidomain pseudospectral time‐domain algorithm in curvilinear coordinates system
Authors: Shi Yan , Liang Chang‐Hong
Published: July 2007

Multidomain pseudospectral time‐domain (MPSTD) algorithm, previously proposed for a Cartesian coordinates system, is extended to Maxwell's equations in a curvilinear coordinates system and applied to electromagnetic wave problems. A novelty patching technique is derived to effectively implement the boundary conditions at the interface between two adjacent subdomains by using characteristic variables. A perfectly matched layer (PML) in a curvilinear coordinates system is constructed according to a well‐posed PML in a Cartesian coordinates system. Numerical results are presented to illustrate the efficiency and accuracy of the method. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2618–2624, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22772
Fully integrated frequency synthesizer design for wireless network application with digital programmability
Authors: Fu Jeffrey Shiang , Teo T. Hui , Tan Eng Leong
Published: July 2007

A 2.60‐GHz integer‐N frequency synthesizer was designed and implemented in SiGe BiCMOS technology. The single chip includes fully integrated VCO (voltage control oscillator) as well as LPF (loop‐filter). The synthesizer provides a wide frequency range of 300 MHz, which covers 2.59–2.66 and 2.8725–2.9025 GHz, with a single VCO. Digital technique is employed at VCO and charge‐pump to cover the frequency range and cater for process variation. Using reference frequency of 2.5 MHz, the fabricated prototype demonstrates a settling time of 32 μs, and reference spur below −56 dBc. The synthesizer's phase noise is −115 dBc/Hz at 1.0‐MHz offset frequency. It consumes approximately 42 mW power from a 3.0 V single supply, with a total active area of 2.34 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2579–2582, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22773
Fractal‐shaped Hi‐Lo microstrip low‐pass filters with high passband performance
Authors: Chen Wen‐Ling , Wang Guang‐Ming , Qi Yi‐Na
Published: July 2007

Hi‐Lo microstrip low‐pass filters using Koch fractal shapes are proposed for the first time. By constructing the low‐impedance sections in Koch‐shaped geometry, the passband performance of the Hi‐Lo microstrip low‐pass filter enhanced greatly. The excellent passband performance is mainly due to the gradual changes of the steps of the fractal‐shaped microstripline, thus to provide weak current discontinuities. To verify the proposed method, low‐pass filter prototypes of different iteration orders are designed, fabricated, and measured, and the measurement results show that the maximal sidelobe level of the passband return loss is reduced from −17.8 to −28.6 dB, and the other performances are not changed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2577–2579, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22774
Microwave analysis of a 70 nm InGaAs pHEMT on InP substrate for nanoscale digital IC application
Authors: Ahlawat Anil , Pandey Manoj , Pandey Sujata
Published: July 2007

A new charge‐control model for the microwave characteristics of an AlGaAs/InGaAs/InP HEMT of 70 nm gate length has been developed. The threshold voltage has been modified by the inclusion of mole fraction and thermal effects. The current voltage characteristics have been obtained and compared with the 70 nm gate length device. In order to avoid short‐channel effects, an aspect ratio (gate length to gate to channel distance) larger than 5 is maintained in the analysis. The small‐signal microwave parameters (gm, gd) have also been evaluated. 2‐D analysis has been carried out in the saturation region. The unity gain cut‐off frequency of the order of 220 GHz is obtained at a gate length of 70 nm. Device parameters so obtained were used to calculate the hemt Y‐parameters. The Y‐parameters hold from the threshold region to the edge of saturation. The unilateral gain so obtained from the Y‐parameters yield a closer fit to the numerical model. All the results have been compared with the experimental data and show a close agreement and the validity of our model. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2462–2470, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22779
An omnipotent Smith chart for lossy nonreciprocal transmission lines
Authors: Wu Yongle , Huang Haiyu , Liu Yuanan
Published: July 2007

The analysis of lossy nonreciprocal transmission line (LNTL in short), which is the most general case in transmission line problems, is presented in this article. By modifying the expression of input impedance, we get a novel graphical tool called omnipotent Smith chart (OSC) for solving LNTL problems. Including all the previous introduced Smith Charts such as the standard Smith chart, the generalized Smith chart for lossless nonreciprocal lines, the generalized Smith chart for lossy reciprocal lines, etc., OSC is omnipotent for different kinds of transmission lines. An OSC can be easily generated using Matlab or Java for applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2392–2395, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22783
Electromagnetic metamorphosis: Reshaping scatterers via conformal anisotropic metamaterial coatings
Authors: Ozgun Ozlem , Kuzuoglu Mustafa
Published: July 2007

We introduce a new technique (in the context of time‐harmonic electromagnetic scattering), which renders an object (or scatterer) to be perceived as if it has a different shape, irrespective of the location of the observer. This is achieved through the usage of an anisotropic metamaterial layer, which is designed as conformal to the surface of the scatterer by employing the concept of coordinate transformation. We report some numerical results for finite element simulations of two‐dimensional anisotropic metamaterial coatings. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2386–2392, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22784
Numerical aspects in the analysis of infinite regular and random helix arrays
Authors: Meiners Christian , Jacob Arne F.
Published: July 2007

This contribution focuses on a scattering description of infinite arrays of small metallic helices. The latter are assumed to scatter like dipoles. A numerical approach is extended to account for the influence of the lattice with more precision. This is done by a simple extrapolation scheme, which accelerates the convergence of the arising series. For regular arrays, a comparison with a commercial software tool reveals a good agreement, at least as long as the distance between the particles is large enough for the dipole assumption to be valid. This also applies at resonance, the most critical case. The effects on random arrays are also investigated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2609–2613, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22788
Nonsurgical method of detection of cancer using microwaves
Authors: Lonappan Anil , Bindu G. , Thomas Vinu , Jacob Joe , Rajasekaran C. , Mathew K. T.
Published: July 2007

This communication presents a novel method of detection of cancer cells in lymph based on the measurement of the dielectric properties at microwave frequencies. The microwave measurements were performed by rectangular cavity perturbation method in the S‐band of microwave frequency with the lymph samples from healthy persons as well as from cancerous patients. It is noticed that a remarkable change in the dielectric properties of cancerous samples with the normal healthy samples and these measurements were in good agreement with clinical analysis. This measurement technique is simple and the cannulation of lymph from persons is least painful and nonsurgical in nature. These results prove an alternative in‐vitro method of diagnosing onset cancer abnormalities using microwaves without surgical procedure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2559–2561, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22792
A 0.18 μm CMOS single‐balanced mixer with LO cancellation for MB‐OFDM UWB direct conversion receiver applications
Authors: Park Bonghyuk , Lee Seungsik , Hong Songcheol , Choi Sangsung
Published: July 2007

This article presents an effective methodology for designing a CMOS single‐balanced down conversion mixer with LO cancellation for MB‐OFDM UWB direct‐conversion receiver. The most crucial drawback of single‐balanced mixer; LO feedthrough is overcome by employing BPF technique for multi‐channel LO signal. The proposed single‐balanced mixer is implemented with 0.18 μm CMOS technology and it operates from 3 to 5 GHz frequency range. The measurement result shows that LO signal amplitude is less than IF signal, the IIP3 is 1 dBm at 4‐GHz band, and the current consumption is 6 mA. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2555–2558, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22793
RETRACTED: Planar rectangular split ring shape band‐pass structures
Authors: Tseng Jan‐Dong , Chang Wei‐Geo
Published: July 2007

A planar rectangular split ring shaped band‐pass structure is proposed and analyzed by coupled line equivalent circuit instead of commonly used LC resonator circuit. The derived results were then used to design two‐ and three‐cascaded rectangular split ring shape structures. Two prototypes were both designed at center frequency at 2.45 GHz, simulated by microwave simulators: IE3D and microwave office, and fabricated on FR‐4 substrate. The simulated and experimental results show good agreement within 0–10 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2520–2523, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22794
A noveltime‐domain technique for nonparaxial ultra short optical pulses
Authors: Masoudi Husain M.
Published: July 2007

A novel nonparaxial technique based on Pade approximant for modeling ultra short optical pulses has been discussed and verified. The characterization of the technique shows excellent performance in terms of accuracy, efficiency, and stability where the traditional paraxial time‐domain beam propagation method failed to achieve. The new method is very useful and efficient for modeling long optical pulse interaction when compared to the classical finite‐difference time‐domain. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2481–2486, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22796
Compact broadband dual‐frequency slot‐loaded rectangular microstrip antenna with ground plane meandering slots and stacking
Authors: K. Usha Kiran , Yadahalli R. M. , M. Vani R. , Farida Sara F. , Hunagund P. V.
Published: July 2007

In this article, compact broadband dual‐frequency slot‐loaded rectangular microstrip antenna with meandering slots in the ground plane and their stacking is presented. Here, first a single‐layer slot‐loaded rectangular microstrip antenna with three identical narrow meandering slots in the ground plane (SLRMSA‐MSGP) has been studied. By meandering slot‐loaded rectangular microstrip antenna with meandering slots in the ground plane, dual frequency compact broadband operation has been achieved. The antenna resonates for dual frequency with a size reduction of 50 and 30% having an enhanced bandwidth of 12 and 4.5%, respectively. Again to further enhance the bandwidth, a meandered rectangular patch (using three slits) is stacked on the single‐layer optimized SLRMSA‐MSGP with meandering slits of the top patch in opposite‐phase with the ground plane meandering slots. Here, the lower frequency of the antenna has been further slightly lowered with a significant enhancement in the bandwidth. Using this configuration, the antenna resonates for compact dual frequency with a size reduction of 54 and 32.3% having an enhanced bandwidth of 16.8% and 3% respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2477–2481, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22797
All optical linearization technique of DFB‐LD based on optical injection locking for RoF system
Authors: Hong Moon‐Ki , Han Sang‐Kook
Published: July 2007

A novel all optical linearization technique using optical injection locking is proposed for radio‐over‐fiber system. When slave laser diode (SLD) is operated under injection locking condition, the modulated optical signals from master laser diode (MLD) are suppressed by residual amplitude modulation suppression. However, these signals are not completely suppressed by imperfection of residual amplitude modulation suppression and remained in the cavity of SLD. By appropriately controlling the phase and amplitude of these signals to have out‐of phase and the same magnitude condition compared with those of direct modulated optical signals from SLD, the efficiency of linearization of DFB‐LD can be more enhanced by optical cancellation in the SLD. By using the proposed technique, 17 dB enhancement of carrier‐to‐interference ratio was experimentally achieved up to frequency response of DFB‐LD compared with that of free‐running case. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2403–2406, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22800
Dual wideband sleeve dipole type antenna for S‐DMB and 2.4/5 GHz WLAN
Authors: Kim S. M. , Yoon K. S. , Yang W. G.
Published: July 2007

A printed dual‐band antenna for S‐DMB and WLAN is proposed. The proposed antenna shows wide impedance bandwidths as well as good radiation patterns and high antenna gains, despite very small volume. The frequency ratio of 2 GHz frequency band and 5 GHz frequency band can be adjusted by variation of the center arm and side arms in the proposed antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2440–2443, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22802
Can end‐to‐side neurorrhaphy bridge large defects? An experimental study in rats
Authors: Lykissas Marios G. , Korompilias Anastasios V. , Batistatou Anna K. , Mitsionis Gregory I. , Beris Alexandros E.
Published: July 2007

This study was undertaken to evaluate collateral sprouting capability in an end‐to‐side repair model with long regenerative distance. Forty‐five rats were used and divided into four groups, according to the reparative procedure following peroneal nerve division: (A) “double” end‐to‐side neurorrhaphy with a regenerative distance of 0.6 cm; (B) “double” end‐to‐side neurorrhaphy with a regenerative distance of 1.2 cm; (C) end‐to‐end neurorrhaphy; and (D) nerve stumps buried into neighboring muscles. In all animals the contralateral healthy side served as a control. Functional assessment of nerve regeneration was performed at intervals up to 5 months using the Peroneal Function Index (PFI). Evaluation 150 days after surgery included peroneal and tibial nerve histologic and morphometric examination and wet weights of the tibialis anterior muscle. Functional evaluation and axonal counting data demonstrated that there was no statistically significant difference between groups A and B, or between groups A and C. There was no functional or histologic evidence of donor nerve deterioration. In conclusion, the present study confirms that “double” end‐to‐side neurorrhaphy may be useful for the repair of divided human nerves with long gaps. Muscle Nerve, 2007
How to toilet train healthy children? A review of the literature
Authors: Vermandel Alexandra , Van Kampen Marijke , Van Gorp Chris , Wyndaele Jean‐Jacques
Published: July 2007

Aims

To review the literature on toilet training (TT) in healthy children.

Methods

Through an extended literature search, all data on developmental signs of readiness for TT, TT methods, definitions of being toilet trained, TT problems, and predictive factors for success were reviewed.

Results

Specific studies on this topic are few. Two main methods for TT have been described so far in the last decades: the gradual child‐oriented training and the structured, endpoint‐oriented training. In the former method parents mainly respond to the child's signals of toileting “readiness”. The latter method consists of actively teaching several independent toileting behaviors. Data are too few to be able to compare the methods. Literature does not give a consensus about the optimal age for starting nor on the expected mean age of completing TT. Recent studies show most children to start training between 24 and 36 months of age with a current trend toward a later completion than in previous generations. The consequence of this can be stress for the parents and more use of diapers, with its negative effect on the environment.

Conclusion

There are as yet little data to be found on this important topic, only few studies have been published in peer‐reviewed journals. Standardization of terminology and critical evaluation of the described techniques in large sample sizes is needed. With this approach, general principles of training, evidence based and easy to use in the majority of children, may become available to parents. Neurourol. Urodynam. 27:162–166, 2008. © 2007 Wiley‐Liss, Inc.
Biochemical and body composition analysis of nocturia in the elderly
Authors: Sugaya Kimio , Nishijima Saori , Oda Masami , Owan Tomoko , Miyazato Minoru , Ogawa Yoshihide
Published: July 2007

Aims

Nocturia is a common symptom in the elderly, and various contributing factors have been suggested. Therefore, in order to investigate which factors are strongly related to occurrence of nocturia, we performed a suite of examinations.

Methods

One hundred eighty volunteers were divided into three groups: a young adult control group (60 healthy persons without nocturia), an elderly control group (60 healthy persons with a low mean frequency of nocturnal urination, i.e., <once per night), and an elderly nocturia group (60 healthy persons with a high mean frequency of nocturnal urination, i.e., more than twice per night). Biochemistry tests, measurement of the osmotic pressure of plasma and urine, and body composition analysis were performed in three groups during the daytime and nighttime. In the elderly control group and the elderly nocturia group, measurement of blood pressure and recording of urinary frequency–volume charts were performed.

Results

The features specific to the elderly nocturia group are as follows: (1) a decrease of the nighttime plasma melatonin level, (2) an increase of nighttime plasma catecholamine levels, (3) an increase of daytime and nighttime plasma natriuretic peptide levels, (4) an increase of blood pressure, (5) a decrease of daytime and nighttime urinary osmotic pressure, (6) an increase of total urine volume, and (7) an increase of the edema ratio before sleeping.

Conclusions

These results suggest that sleep disturbance, hypertension, and excessive fluid intake are major factors contributing to an increased frequency of nocturnal urination (>twice per night) in the elderly. Neurourol. Urodynam. 27:205–211, 2008. © 2007 Wiley‐Liss, Inc.
Political marketing in untraditional campaigns: the case of David Cameron's Conservative Party leadership victory
Authors: Ormrod Robert P. , Henneberg Stephan C. , Forward Nick , Miller James , Tymms Leigh
Published: July 2007

This study investigates the concept of political market orientation (PMO) in an untraditional setting, namely the 2005 contest for the leadership of the British Conservative Party. Based on a collective case‐study method, a content analysis of candidates' speeches and manifestos is provided. We operationalize four attitudinal constructs of a conceptual PMO model and adapt them to suit the novel campaign context. Our findings show further evidence for the existance of a ‘gravitational centre’ effect hypothesized in earlier studies. Furthermore, we qualify the concept of PMO through a long‐term focus and a context‐specific evaluation of the merits of alternative PMO profiles. Thus, the generic conceptual model of political market orientatation, which previously has only been used in the content of parties contesting a general election campaign, can be adapted to alternative campaign situations without a reduction in its explanatory power.

Copyright © 2007 John Wiley & Sons, Ltd.
Too much of a good thing: the ‘problem’ of political communications in a mass media democracy
Authors: Gaber Ivor
Published: July 2007

Francis Fukuyama asks: ‘… is liberal democracy prey to serious internal contradictions, contradictions so serious that they will eventually undermine it as a political system?’ This paper argues that one of these ‘internal contradictions’ is the political communications process and it can be sufficiently serious to undermine the democratic system—but such an undermining is not inevitable. The problem can be described as follows: Democratic systems require that citizens are kept fully informed by governments (and others) in the interests of transparency and ultimately accountability. Hence, all political communications have, as their final objective, the accountability of politicians at the ballot box. Thus all political communications have what can be described as ‘above’ and ‘below’ the line content. The above‐the‐line is the actual content of the message, the below‐the‐line is the implicit one of ‘think better of me and my colleagues think worse of my opponents’. Consequently, no matter how personally honest and open an individual politician might be, the democratic system requires her or him to be always thinking about securing a successful result at the ballot box. Thus we have the ‘political communications paradox’. Voters want politicians to be honest and accountable but this very demand means that politicians, implicitly, always have to have another agenda in operation when they are communicating with the public, i.e. securing their approval and then their support. As a result the trust which is a fundamental to the workings of a democratic system is constantly being undermined. This has two effects. First, that governments are obliged to make communications, rather than delivery, their real priority and second trust, not just in politicians but in the political system as a whole, tends to wane over time, which in turn endangers the very system it was designed to underpin. But this decline is not inevitable because the system has some in‐built self‐correcting mechanisms These include: the rise of new parties and/or leaders who portray themselves as ‘new’ and ‘untainted’—New Labour, New Conservatives, etc., an almost regular ‘re‐balancing’ of the power relationship that exists between politicians and the civil service, particularly in the communications field, the rise of new forms of communication that seek to by‐pass the institutional roadblocks that are perceived as being the cause of the problems and finally increased attention by journalists and academics to the process of political communications makes it more difficult for politicians to continue with ‘business as usual’ as far as their communication activities are concerned.

Copyright © 2007 John Wiley & Sons, Ltd.
Framing lobbying messages: defining and communicating political issues persuasively
Authors: McGrath Conor
Published: July 2007

The concept of product positioning is well established in the commercial communication sphere, as are the notions of issue definition and agenda setting in the field of political science. Less thoroughly researched, though, is an area which intersects these two fields—the way in which lobbyists use language in order to frame policy issues so as to position their organization and its policy preferences to greatest effect. Lobbyists consciously frame and define issues in an effort to encourage policy makers both to share the lobbyist's perspective on a given policy problem, and to suggest to those policy makers what policy solution ought to be adopted. In doing so, they explicitly draw upon ideas and practices more commonly associated with other forms of commercial communication such as advertising and marketing. This paper suggests that the use of language by lobbyists is a potentially fruitful field for both academics and practitioners interested in political communication broadly defined—indeed, lobbying is essentially a form of persuasive communication in the political arena. It is well understood that how political issues are presented is an important factor in the extent to which an issue will be supported; this paper focuses on how lobbyists make use of this understanding in their efforts to achieve a desired policy outcome.

Copyright © 2007 John Wiley & Sons, Ltd.
Developing the public affairs body of knowledge
Authors: Fleisher Craig S.
Published: July 2007

This paper examines the need for developing a public affairs body of knowledge (BOK). It examines the rationale for having a BOK within a larger context of professionalism in the field, identifies parallel developments in affiliated fields that may provide models for public affairs, and offers alternatives for stakeholders of the field to pursue this objective.

Copyright © 2007 John Wiley & Sons, Ltd.
Reigniting the fire: a contemporary research agenda for social, political and nonprofit marketing
Authors: Dann Stephen , Harris Phil , Mort Gillian Sullivan , Fry Marie‐Louise , Binney Wayne
Published: July 2007

The paper reports on the core challenges faced by the nonprofit, political and social marketing disciplinary areas and suggests a series of research agendas to develop theory and practice to meet these challenges.

Social marketing's research agenda involves the continued adaptation of the new developments in commercial marketing, whilst building a base of social marketing theory and best practice benchmarks that can be used to identify, clarify and classify the boundaries of social marketing against social change techniques.

Nonprofit marketing is pursuing the dual research agenda of developing the theory and practice of social entrepreneurship whilst seeking deeper consumer‐based research to understand motivations for charitable behaviour and gift giving.

Political Marketing's research agenda looks for an increase in the level of background research, core data and market research to use as a basis for developing more advanced theoretical and practical models. In addition, as political marketing is being transferred internationally between a range of political and electoral systems, there is a need for comparative research into both the relevance and effectiveness of these techniques to isolate nation independent and nation dependent political marketing strategies and campaigns.

Copyright © 2007 John Wiley & Sons, Ltd.
Were Bosnian policy research organisations more effective in 2006 than in 2003? Did technical assistance play a role?
Authors: Struyk Raymond J. , Kohagen Kelly , Miller Christopher
Published: July 2007

In 2003 the policy development process in Bosnia and Herzegovina was characterised by international community (IC) dominance. The IC provided the vast majority of the analysis of problems facing the country and drafted many of the laws. This article documents developments from fall 2003 to fall 2006 in the use of evidence and analysis in the policy development process and the role of local policy research organisations (PROs—often called think tanks) in it. The likely relation between these changes and the activities of a PRO mentoring project that operated over the same period is also assessed. Evidence comes as a series of interviews in both years with government officials and members of parliament, on the one hand, and leaders of PROs and advocacy NGOs on the other. The broad picture that emerges from the above review is of a substantial positive development in the policy development process in Bosnia and Herzegovina over the period. Factual evidence and analysis are playing a much greater role, and PROs have been a major provider of this information. The evidence indicates that PROs have been successful in convincing the policy community that they are purveyors of objective, disinterested advice and analysis. The improvements occurred in a conducive environment that steadily placed greater responsibility for policy formation on Bosnian officials. Copyright © 2007 John Wiley & Sons, Ltd.
Combined NMR, SERRS, and DFT study of photochemical and thermal reactions of acetylene‐ and thienylacetylene‐substituted chromenes
Authors: Maurel F. , Delbaere S. , Truong S. Lau , Couesnon T. , Dubest R. , Vermeersch G. , Aubard J.
Published: July 2007

Nuclear Magnetic Resonance (NMR), Surface‐Enhanced Resonance Raman Scattering (SERRS), and Density Functional Theory (DFT) were used to study 8‐substituted acetylene‐ and thienylacetylene‐diphenylnaphthopyran photochromic compounds. The purpose of this work is to determine the effect of the 8‐acetylene substituent on the photochromic equilibrium. NMR spectroscopy shows that photocoloration by UV irradiation at low temperature leads to a mixture of transoid isomers (TC and TT) and a small amount of an allenyl‐naphthol structure. The mixture is further enriched in this latter isomer by subsequent visible irradiation. Some photoproducts are identified by analysis of the changes in the SERRS spectra of an irradiated solution with time. To assist spectral assignment, the vibrational frequencies of compounds (1) and (2) and their photoproducts were computed at optimized geometries and compared with the observed Raman bands. Copyright © 2007 John Wiley & Sons, Ltd.
Photodimerization of soluble tetracene derivatives using visible light
Authors: Olive Alexandre G. L. , Del Guerzo André , Pozzo Jean‐Luc , Desvergne Jean‐Pierre , Reichwagen Jens , Hopf Henning
Published: July 2007

2,3‐Didecyloxytetracene (2,3‐DDOT) is a yellow‐orange soluble derivative that undergoes a strong de‐coloration upon irradiation with visible light (470 nm). This is due to a photoreaction (Φr = 5.9 × 10−3) that leads to the formation of four photodimers, involving only the two central rings of the tetracene core. Copyright © 2007 John Wiley & Sons, Ltd.
Tyrosinase inhibitory pentacyclic triterpenes and analgesic and spasmolytic activities of methanol extracts of Rhododendron collettianum
Authors: Ullah Farman , Hussain Hidayat , Hussain Javid , Bukhari Ishfaq A. , Khan Mahmud Tareq Hassan , Choudhary M. Iqbal , Gilani Anwar H. , Ahmad Viqar Uddin
Published: July 2007

During the course of screening of medicinal plants of Pakistan for the isolation and structure elucidation of bioactive natural products, it was found that the methanol extract of the Rhododendron collettianum showed analgesic and spasmolytic activities. The methanol extract was then extracted with chloroform. Nine pentacyclic triterpenes were isolated from the chloroform extract and their structures were elucidated as erythrodiol (1), betulinic acid (2), maslinic acid (3), 2α,3α,23‐trihydroxyolean‐12‐en‐28‐oic acid (4), bayogenin (5), arjunilic acid (6), methyl arjunolate (7), arjungenin (8) and 3β, 23, 24‐trihydroxyolean‐12‐en‐28‐oic acid (9). Among the triterpenes (1–9) tested, arjunilic acid (6) was found to be most potent. Their structure–activity relationship (SAR) showed that if the configuration of the –OH group at C‐2 is changed from α to β the potency is decreased. In most of the compounds the position and configuration of the –OH group was found to be important for the inhibitory potency against the enzyme tyrosinase. For the comparison, the standard tyrosinase inhibitors kojic acid (IC50 = 16.67 µm) and l‐mimosine (IC50 = 3.68 µm) were used as controls. Copyright © 2007 John Wiley & Sons, Ltd.
Hippomanin a from acetone extract of Phyllanthus urinaria inhibited HSV‐2 but not HSV‐1 infection in vitro
Authors: Yang Chien‐Min , Cheng Hua‐Yew , Lin Ta‐Chen , Chiang Lien‐Chai , Lin Chun‐Ching
Published: July 2007

Phyllanthus urinaria Linnea (Euphorbiaceae) is a commonly used traditional medicinal plant in oriental countries and has been reported to possess various biological activities. Previously, the acetone extract and some pure compounds from P. urinaria were found to suppress herpes simplex virus (HSV). In this study, another two pure compounds were isolated from acetone extract of P. urinaria and were tested for their in vitro anti‐HSV‐1 and HSV‐2 activities. The results showed that hippomanin A impeded HSV‐2 but not HSV‐1 infection. Corilagin, however, inhibited neither HSV‐1 nor HSV‐2 replication. The similarity between corilagin and hippomanin A in structure, but difference in antiviral activity, therefore, merit further investigation. Copyright © 2007 John Wiley & Sons, Ltd.
The detection of antibacterial actions of whole herb tinctures using luminescent Escherichia coli
Authors: Watt Kathryn , Christofi Nick , Young Rodney
Published: July 2007

Two whole cell Escherichia coli luminescent biosensors were used to determine the antibacterial actions of 16 herbal tinctures. These bioassays can detect genotoxic (strain DPD2794) and general oxidative stress (DE135) events when challenged with antibacterial substances. Many of the herbal tinctures were active against these Gram‐negative bacteria, affecting their metabolism without, in some cases, arresting cell growth or causing cell death. Antibacterial activity ranged from undetectable for Curcuma longa, Cinnamomum zeylanicum and Apium graveolens to highly effective against both E. coli strains in the case of Rosmarinus officinalis. Some of the results were unexpected. Althaea officinalis affected microbial metabolism in spite of the lack of literature precedent, and Cinnamomum zeylanicum did not appear to be antimicrobial, as claimed in some literature.

It is concluded that studies using luminescent bacterial biosensors can provide important new insights into the potency and modes of the lethal and sub‐lethal antibacterial action of whole herbs, and thereby provide crucial evidence for efficacy demanded by modern science and medicine. Copyright © 2007 John Wiley & Sons, Ltd.
Novel method for measurement of glutathione kinetics in neonates using liquid chromatography coupled to isotope ratio mass spectrometry
Authors: Schierbeek Henk , te Braake Frans , Godin Jean‐Philippe , Fay Laurent‐Bernard , van Goudoever Johannes B.
Published: July 2007

A novel analytical method using liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) was developed for measuring the fractional synthesis rate (FSR) of glutathione (GSH) in neonates after infusion of [1‐13C]‐glycine as a tracer. After transformation of GSH into GSSG, its dimeric form, the intra‐erythrocytic concentration and 13C‐isotopic enrichment of GSH were determined using 200 µL of blood. The results showed that, using LC/IRMS, the concentration (range of µmol/mL) was reliably measured using norvaline as internal standard with precision better than 0.1 µmol/mL. In addition, the 13C‐isotopic enrichment measured in the same run gave reliable values with excellent precision (with standard deviation (sd) lower than 0.3‰) and accuracy (measured between 0 and 2 Atom % Excess (APE)). The inter‐assay repeatability of δ13C of norvaline used as internal standard with in vivo samples was assessed at −26.07 ± 0.28‰ with coefficient of variance (CV) at 1.1%. The FSR calculated either with GSH or GSSG showed similar results with slightly higher values for GSSG (41.6 ± 4.7 and 46.5 ± 4.4, respectively). The slightly lower FSR of GSH is probably due to interfering compounds in the biological matrix. Successfully used in a clinical study, this rapid and reliable method opens up a variety of kinetic studies with relatively low administration of tracer infusates, reducing the total cost of the study design. The small volume of blood needed enables studies even in extremely small subjects, such as premature infants, as reported in this study. Copyright © 2007 John Wiley & Sons, Ltd.