bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a broadband power amplifier using an optimized feedback network
Authors: Kim K. , Seo M. , Jeon J. , Kim M. , Kim H. , Lim H. , Park C. , Yang Y.
Published: September 2011

This article presents a systematic design method for ultra broadband power amplifiers using an optimized feedback network. Based on the analysis using the network parameters for the open‐loop circuit and feedback network, a design and optimization procedure was established. To make the gain response as flat as possible throughout the broad operating frequency band, the optimized component values of the feedback network were found using an optimization program which was built based on the least‐mean‐square‐error algorithm in MATLAB. Single‐ended broadband power amplifiers were implemented to verify the optimization results for various target gains, as well as source and load impedance sets. One of the single‐ended amplifiers was selected for use as part of the push–pull power amplifier which includes broad‐band 1:1 transmission line transformers. For the operational bandwidth from 8 to 800 MHz, the ultra broad‐band push–pull power amplifier exhibited a flat gain response of ±0.331 dB from 17.2 dB, a P1dB of more than 40.5 dBm, and high PAE from 26.7 to 45 % at each P1dB point. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2846–2851, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26372
A novel microstrip band‐pass filter based on hole coupling structure
Authors: Yuan Yan , Xu Jun , Xu Yan‐Qing , Zhang Xiao‐Chuan
Published: September 2011

A novel C‐band hole‐coupled bandpass filter with metallized post (or via‐hole) arrays directly embedded in middle of the microstrip line is presented in this letter.The proposed filter removes via‐hole arrays embedded along waveguide section from the half‐mode substrate integrated waveguide filter, while the new concept simplifies the structure of previous filter. Simulated and experimental results show that the proposed filter of this paper has good performances of low insertion loss, return loss, and better rejection characteristics. The insertion loss of measured four‐pole filter is about 0.8 dB, and the return loss is better than −25 dB in the whole passband. Keeping the advantages of excellent performances, the proposed filter can be constructed more conveniently and is suitable for low‐cost planar circuit. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2811–2814, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26373
CMOS (2.28 mW, 67.28–80.78 GHz) divide‐by‐4 direct injection‐locked frequency divider using tunable LC source‐degeneration
Authors: Chen Chang‐Zhi , Wang Chien‐Chin , Lin Yo‐Sheng , Huang Guo‐Wei
Published: September 2011

A 67.28–80.78 GHz CMOS divide‐by‐4 direct injection‐locked frequency divider (DILFD4) using tunable LC source‐degeneration (TLCSD) for operation frequency and locking range (LR) enhancement is demonstrated.The TLCSD is made by adding two tunable LC tanks, where varactors are used as the required capacitors, to the source terminals of the cross‐coupled transistor pair of the DILFD4. Compared with the traditional cross‐coupled transistor pair, the proposed one significantly decreases the equivalent parallel capacitance (CEQ). This in turn results in the increase of both the operation frequency and the LR of the DILFD4. The DILFD4 dissipated 2.28 mW from a 1.2 V power supply and achieved a total LR of 18.24% (i.e., 13.5 GHz, from 67.28 to 80.78 GHz). Furthermore, the DILFD4 achieved excellent output phase‐noise of −137.14 dBc/Hz at 1 MHz offset when the input signal was locked at 68.116 GHz. The chip area was 1.025 × 0.765 mm2 excluding the test pads. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2776–2781, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26385
A transceiver with injection‐locked frequency multiplier for short‐range wireless applications
Authors: Chen Hsiao‐Chin , Kuo Chia‐Hao , Lee Wei‐Kan
Published: September 2011

A transceiver with injection‐locked frequency multiplier is presented in 0.18‐μm CMOS technology for short‐range wireless medical applications. The injection‐locked technique is applied to a frequency multiplier to synthesize the low‐phase‐noise RF carrier of the transmitter, where a crystal oscillator is used as the signal source for injection and an 888‐MHz carrier is synthesized from the 55.5‐MHz crystal by the frequency multiplier. At 888 MHz, the injection‐locked frequency multiplier exhibits low phase noise of −116 dBc/Hz within offset frequency range from 100 kHz to 1 MHz. In addition, a receiver is implemented by adopting envelope detection architecture. The transmitter delivers an output power of −14 dBm at 22.2 mW and the receiver achieves a sensitivity of −58 dBm at 4.1 mW. With off‐chip antennas, a wireless link can be established by the transmitter and the receiver at a distance of 30 cm. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2733–2737, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26387
Enhanced optical single sideband modulation based on fiber nonlinearity
Authors: Tsai W. S. , Lin Z.S. , Hsu C. H.
Published: September 2011

We propose an optical single sideband (OSSB) modulation scheme using stimulated Brillouin scattering (SBS) in fiber to achieve OSSB modulation. Drive with 10.87‐GHz radio frequency signal into Mach–Zehnder modulator (MZM). Because of the SBS effect, lower sideband of modulated signal is amplified and upper sideband is attenuated as well. By properly adjust the phase shifter for phase difference between the two paths of electrical signal. Output signal is OSSB format, after 25‐km SMF transmission, we can observe good system performances including sideband power ratio and phase noise using by an optical spectrum analyzer and an electrical spectrum analyzer. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2730–2733, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26388
All‐electronic terahertz spectrometer for biosensing
Authors: Debus Christian , Spickermann Gunnar , Nagel Michael , Bolívar Peter Haring
Published: September 2011

A compact and cost‐efficient all‐electronic terahertz (THz) system is presented for the spectroscopic read‐out of marker‐free THz biosensor chips. The table‐top system is based on only one oscillator for emitter and quasi‐heterodyne detector operation. Frequency mixing is applied to perform THz signal frequency sweeps from 220 to 320 GHz in less than 250 μs. The concept is explained and demonstrated at exemplary biochip measurements. Results and performance of the electronic system are compared with the laser‐based THz‐time‐domain spectroscopy. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2889–2902, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26392
HF Antenna design optimization for railway spot signalling systems
Authors: Sancho Juan Ignacio , Mendizábal Jaizki , Gurutzeaga Iñaki , Villaro Almir , Adin Iñigo , Bistue Guillermo
Published: September 2011

Transmitting antenna in a Railway Spot Signalling System needs to be optimized in order to ensure data transfer reliability and minimize the required power. This paper analyses the improvement of the HF transmitting antenna taking into account the size of the receiving antenna, the presence of metallic objects and the misalignment between transmitting and receiving antennas. A novel HF transmitting antenna structure is proposed and verified to improve the read range. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2742–2746, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26400
Design of MIMO antenna positions for mobile handset when considering nondeterministic channels
Authors: Uthansakul Peerapong , Assanuk Danai , Uthansakul Monthippa
Published: September 2011

The topic of practical implementation of multiple input multiple output (MIMO) systems for mobile communications has recently gained a lot of attention.Due to the area constraint on a mobile handset, the problem of how to design such a system in order to achieve the best benefit is still a huge challenge. Most researches in this area concern the algorithms to configure the best layout of multiple antennas while assume the wireless channel as the deterministic model. However, mobile users might roam from one channel condition to the others, which the benefit of deterministic antenna positions does no longer exist. In this article, the concern of channel variation has been included in the process of finding MIMO antenna positions. A genetic algorithm (GA) is employed to find the optimal antenna positions on mobile handset for 4 × 4 MIMO systems. The effects of mutual coupling based on Z‐parameter is the main factor to determine the MIMO capacity concerning as the objective function of GA search. The results suggest that the use of average positions among solutions obtained by various channels provide the most compromising benefits to practically design MIMO antenna positions on mobile handset. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2737–2742, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26402
Micromachinned monopole antenna by CMOS‐Compatible deep trench technology
Authors: Wang Tao , Lu Shey‐Shi
Published: September 2011

A monopole antenna fabricated by standard 0.18 μm CMOS technology is post‐IC processed by CMOS compatible inductively coupled plasma etching, which can remove the silicon substrate selectively under the metal strips. After substrate release, the resonance of the monopole antenna reveals owing to elimination of the energy confinement from the high‐dielectric media. Experimental results show an improvement of input return loss (S11) from −9 to –14.3 dB by such substrate release technique. The power transfer ratio also increases from 0.87 to 0.96 for better radiation efficiency. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2971–2973, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26403
Wideband planar slotted radiating ground plane antenna for portable devices
Authors: Sonkki Marko , Antonino‐Daviu Eva , Ferrando‐Bataller Miguel , Salonen Erkki T.
Published: September 2011

A method for exciting currents in a radiating ground plane over a wide frequency bandwidth is presented. Using a complementary slot in the ground plane excited by a closely spaced monopole (0.008–0.05λ) with 50 Ω input impedance, a wide frequency bandwidth can be achieved to cover multiple radio interfaces. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2854–2858, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26408
A CPW‐fed annular slot‐antenna with an L‐shaped strip
Authors: Chang The‐Nan
Published: September 2011

A slot‐ring with any type of asymmetry can support more than one mode. Based on this simple observation, a short coplanar waveguide (CPW)‐fed annular slot‐antenna backed by an L‐shaped strip is investigated in this article. On one hand, the annular slot‐ring with a backed L‐shaped strip and without the shorted stub is enough to generate a circularly polarized (CP) wave. On the other hand, the annular slot‐ring with a shorted stub and without the backed L‐shaped strip is enough to yield a broadband operation. In this article, we integrate both types of asymmetry in an annular slot‐ring. We can achieve 10 dB return loss bandwidth from 2.4 to 4.5 GHz. Within this wide band, a CP wave is observed at the 2.45 GHz band. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2821–2827, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26416
Ultra‐broad and multiband 3D‐monopole antennas
Authors: Elsheakh Dalia M. , Safwat Amr M. E.
Published: September 2011

Novel three‐dimensional antennas that provide either multibands or ultra‐broadband are presented. The proposed structures are based on monopole antennas loaded with meander lines. For operation of multibands, the monopole is loaded with different‐length meander lines connected in series. The proposed antenna has 55 × 66 × 130 mm3 volume and operates in the following bands: 200 MHz, 800 MHz, 1.1 GHz, 1.4 GHz, 2.45 GHz, 3 GHz, and 3.7 GHz. Ultra‐broadband is achieved by connecting four monopoles in parallel. Each monopole is loaded with two meander lines. The resulting bandwidth extends from 400 MHz to 3.5 GHz, which is suitable for digital video broadcasting‐T applications, and the size is 53 × 68 × 87 mm3. Both antennas have omnidirectional radiation patterns. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2843–2846, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26417
UMTS diplexer design using the antiparallel‐coupled lines loaded with a stepped impedance resonator
Authors: Ho Min‐Hua , Lin Wei‐Chen
Published: September 2011

We present a novel UMTS diplexer design using the filters of antiparallel‐coupled lines structure loaded with a stepped impedance microstrip resonator. The diplexer is composed of two filters. And a microstrip line of quarter‐wavelength is used to links each filter to the common port. The composing filters exhibit two tunable transmission zeros which are used to implement the mid‐passband zero implantation for improving the isolation between the transmitting (Tx) and the receiving (Rx) ports. A pair of spurlines is used in the coupled lines of the Tx‐filter to further increase the isolation. An experiment is conducted to assure the diplexer's performance and to verify the circuit design. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2988–2990, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26421
Frequency‐tunable terahertz electromagnetic‐pulses generation based on an optical Fabry–Perot microresonator with variable birefringence material
Authors: Chen Ming
Published: September 2011

A frequency‐tunable terahertz (THz)‐frequency electromagnetic‐pulses generation method is proposed based on an optical Fabry–Perot (FP) microresonator with variable birefringence materials. At the output FP microcavity, polarization mode beat with high‐frequency can be achieved due to the phase mismatch effect of the two polarization modes in the birefringence materials in the FP cavity. One can generate frequency‐tunable electromagnetic pulse radiation through changing the birefringence of the materials. When the birefringence changed from 3.7355 × 10−4 to 7.4710 × 10−2, electromagnetic‐pulses with frequencies from 0.05 to 10.0 THz can be obtained. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2879–2882, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26422
Optical millimeter‐wave generation based on an external modulator
Authors: Zhu Jia Hu , Huang Xu Guang
Published: September 2011

Optical millimeter‐wave (mm‐wave) generation based on an external modulator is proposed and simulately demonstrated.Both theoretical analysis and simulation results reveal that doubling‐frequency, quadrupling‐frequency, sextupling‐frequency, octupling‐frequency, decupling‐frequency, 12‐fold‐frequency, dual quadrupling‐frequency, or dual octupling‐frequency mm‐waves can be generated in this scheme. The frequency of local oscillator signal is largely reduced because frequency octupling, frequency decupling, or frequency 12‐fold mm‐wave is generated. The overall cost of the system is largely reduced. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2902–;2907, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26432
A dual‐band RF front end for DVB‐H direct conversion receiver
Authors: Jung Seung Hwan , Eo Yunseong
Published: September 2011

A dual‐band RF front end for the DVB‐H direct conversion receiver is implemented using 0.18‐μm CMOS technology. To achieve the low‐NF and high‐IIP3 performance, the LO stage of the passive mixer is optimized with respect to the transistor size and gate bias. The measured results show that the NF is below 4.8 dB and the IIP3 at low‐noise amplifier off state is above +3.5 dBm all over the bands. The chip size is 0.75 mm2 excluding pads and the current consumption is 5.6 and 6 mA at 1.8 V supply, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2796–2799, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26438
Allowing for missing outcome data and incomplete uptake of randomised interventions, with application to an Internet‐based alcohol trial
Authors: White Ian R. , Kalaitzaki Eleftheria , Thompson Simon G.
Published: September 2011

Missing outcome data and incomplete uptake of randomised interventions are common problems, which complicate the analysis and interpretation of randomised controlled trials, and are rarely addressed well in practice. To promote the implementation of recent methodological developments, we describe sequences of randomisation‐based analyses that can be used to explore both issues. We illustrate these in an Internet‐based trial evaluating the use of a new interactive website for those seeking help to reduce their alcohol consumption, in which the primary outcome was available for less than half of the participants and uptake of the intervention was limited.

For missing outcome data, we first employ data on intermediate outcomes and intervention use to make a missing at random assumption more plausible, with analyses based on general estimating equations, mixed models and multiple imputation. We then use data on the ease of obtaining outcome data and sensitivity analyses to explore departures from the missing at random assumption. For incomplete uptake of randomised interventions, we estimate structural mean models by using instrumental variable methods.

In the alcohol trial, there is no evidence of benefit unless rather extreme assumptions are made about the missing data nor an important benefit in more extensive users of the intervention. These findings considerably aid the interpretation of the trial's results. More generally, the analyses proposed are applicable to many trials with missing outcome data or incomplete intervention uptake. To facilitate use by others, Stata code is provided for all methods. Copyright © 2011 John Wiley & Sons, Ltd.
Locally Advanced Mid/Low Rectal Cancer with Synchronous Liver Metastases
Authors: Viganò Luca , Karoui Mehdi , Ferrero Alessandro , Tayar Claude , Cherqui Daniel , Capussotti Lorenzo
Published: September 2011

Background

Management of patients with T3/4 and/or N+ mid/low rectal cancer with synchronous liver metastases is not codified. The aim of this study was to analyze outcomes of our approach which consists of neoadjuvant chemotherapy or chemoradiotherapy, according to liver disease extension, followed by simultaneous rectal and liver resection.

Methods

Between 2000 and 2009, 354 patients underwent hepatectomy for synchronous metastases. Thirty‐six consecutive patients who underwent rectal and liver resection for metastatic T3/4 and/or N+ mid/low rectal cancer were analyzed.

Results

Liver metastases were multiple in 27 patients, bilobar in 22, and >5 cm in six. Up‐front treatment was chemotherapy in 15 patients, chemoradiotherapy in seven, chemotherapy followed by chemoradiotherapy in six, and surgery in eight (five symptomatic tumors). After chemotherapy alone (median number of cycles = 6), primary tumor response was observed in 11 patients (three complete responses). After chemoradiotherapy, only one patient had liver disease progression. Eighty‐nine percent of patients underwent simultaneous rectal and hepatic resection. Mortality and morbidity rates were 2.8% (one pulmonary embolism) and 36%, respectively. After a mean follow‐up of 39 months, 5‐year overall and disease‐free survival were 59.3 and 39.6%, respectively. Twenty‐one patients had recurrence, including three pelvic recurrences (8.3%). No pelvic recurrence occurred among patients who correctly completed treatment strategy. All patients who received neoadjuvant chemoradiotherapy were alive and disease‐free; 5‐year overall and disease‐free survival of patients receiving neoadjuvant chemotherapy were 59.3 and 25%, respectively.

Conclusions

For patients with metastatic T3/4 and/or N+ mid/low rectal cancer, the present strategy was safe and effective. Good disease control was achieved by neoadjuvant treatments, low morbidity rates were associated with simultaneous resection, and excellent long‐term outcomes with low local relapse rate were obtained.
Robotic Versus Open Pancreaticoduodenectomy: A Comparative Study at a Single Institution
Authors: Buchs Nicolas Christian , Addeo Pietro , Bianco Francesco Maria , Ayloo Subhashini , Benedetti Enrico , Giulianotti Pier Cristoforo
Published: September 2011

Background

Minimally invasive pancreaticoduodenectomy (PD) remains one of the most challenging abdominal procedures, and its application is poorly reported in the literature so far. To date, few data are available comparing a minimally invasive approach to open PD. The aim of the present study is to compare the robotic and open approaches for PD at a single institution.

Methods

Data from 83 consecutive PD procedures performed between January 2002 and May 2010 at a single institution were retrospectively reviewed. Patients were stratified into two groups: the open group (n = 39; 47%) and the robotic group (n = 44; 53%).

Results

Patients in the robotic group were statistically older (63 years of age versus 56 years; p = 0.04) and heavier (body mass index: 27.7 vs. 24.8; p = 0.01); and had a higher American Society of Anesthesiologists (ASA) score (2.5 vs. 2.15; p = 0.01) when compared to the open group. Indications for surgery were the same in both groups. The robotic group had a significantly shorter operative time (444 vs. 559 min; p = 0.0001), reduced blood loss (387 vs. 827 ml; p = 0.0001), and a higher number of lymph nodes harvested (16.8 vs. 11; p = 0.02) compared to the open group. There was no significant difference between the two groups in terms of complication rates, mortality rates, and hospital stay.

Conclusions

The authors present one of the first studies comparing open and robotic PD. While it is too early to draw definitive conclusions concerning the long‐term outcomes, short‐term results show a positive trend in favor of the robotic approach without compromising the oncological principles associated with the open approach.
The Whiter the Better? Racial Composition and Access to School Resources for Black Students
Authors: Diette Timothy M.
Published: September 2011

Rigorous courses are an important resource, distributed within schools, that merit attention as a central determinant of student achievement and future outcomes (Cook and Evans, J Labor Econ. 18(4):729–754, 2000; Rose and Betts, Rev Econ Stat. 86(2):497–513, 2004). Yet, black students are less likely to be enrolled in advanced courses in general (ex. Darity et al. 2001; Klopfenstein, Contemp Econ Pol. 23(3):416–28, 2005) and specifically Algebra 1 in middle school (Riley 1997). Debate exists around the potential benefits or drawbacks for black students attending highly integrated schools relative to highly segregated schools. This study examines which school characteristics are associated with large disparities in black student enrollment in Algebra 1 relative to white student enrollment in Algebra 1 in the same middle schools in North Carolina. Of particular interest is the relationship between access and the percentage of white students in a school. The study finds that: (1) black students are underrepresented in Algebra 1 in essentially all schools in North Carolina; (2) the largest disparities occur in schools that are highly integrated while the disparities are reduced in schools that are either large majority white or large majority non-white; (3) schools with a larger share of white teachers are related to larger disparities between black and white students; (4) the marginal effects of racial composition on the relative disparity in enrollment are significantly larger for black females than black males.
Value creation and pricing in buyouts: Empirical evidence from Europe and North America
Authors: Achleitner Ann‐Kristin , Braun Reiner , Engel Nico
Published: September 2011

Using a unique proprietary data set of 1980 realized and unrealized buyouts completed between 1986 and 2010, we examine entry and exit pricing in buyouts and its influence on private equity (PE) sponsors' returns. We find that besides leverage and operational improvements, EBITDA multiple expansion (i.e. the difference between entry and exit pricing) is a fundamental factor in explaining equity returns and the result of skill rather than pure luck. We also provide evidence that more experienced PE sponsors use more debt to finance a PE transaction and debt is positively related to entry buyout pricing. However, for a transaction with a given leverage level, more experienced PE sponsors are able to negotiate lower prices. In addition, our results show that deals conducted by first time funds which are realized in a later stage of a fund's life cycle are associated with lower exit prices which can be explained by the increased exit pressure for the PE sponsor.
Predictive validity of pharmacologic interventions in animal models of neuropathic pain
Authors: Honoré Per Hartvig , Basnet Anna , Kristensen Pernille , Andersen Lene Munkholm , Neustrup Signe , Møllgaard Pia , Eljaja Laila , Bjerrum Ole J.
Published: September 2011

Introduction

The pathophysiologic and neurochemical characteristics of neuropathic pain must be considered in the search for new treatment targets. Breakthroughs in the understanding of the structural and biochemical changes in neuropathy have opened up possibilities to explore new treatment paradigms. However, long term sequels from the damage are still difficult to treat.

Aim of the study

To examine the validity of pharmacological treatments in humans and animals for neuropathic pain.

Method

An overview from the literature and own experiences of pharmacological treatments employed to interfere in pain behavior in different animal models was performed.

Results

The treatment principles tested in animal models of neuropathic pain may have predictive validity for treatment of human neuropathies. Opioids, neurotransmitter blockers, drugs interfering with the prostaglandin syntheses as well as voltage gated sodium channel blockers and calcium channel blockers are treatment principles having efficacy and similar potency in humans and in animals. Alternative targets have been identified and have shown promising results in the validated animal models. Modulators of the glutamate system with an increased expression of glutamate re-uptake transporters, inhibition of pain promoters as nitric oxide and prostaglandins need further exploration. Modulation of cytokines and neurotrophins in neuropathic pain implies new targets for study. Further, a combination of different analgesic treatments may as well improve management of neuropathic pain, changing the benefit/risk ratio.

Implications

Not surprisingly most pharmacologic principles that are tested in animal models of neuropathic pain are also found to be active in humans. Whereas many candidate drugs that were promising in animal models of neuropathic pain turned out not to be effective or too toxic in humans, animal models for neuropathic pain are still the best tools available to learn more about mechanisms of neuropathic pain. Better understanding of pathogenesis is the most hopeful approach to improve treatment of neuropathic pain.
POWER-FREE VALUES OF THE POLYNOMIAL t1⋯tr−1
Authors: LE BOUDEC PIERRE
Published: September 2011

Let k,r≥2 be two integers. We prove an asymptotic formula for the number of k-free values of the r variables polynomial t1⋯tr−1 over [1,x]r∩ℤr.
Morning versus afternoon cutting time of Berseem clover (Trifolium alexandrinum L.) affects feed intake, milk yield and composition in Girgentana goats
Authors: Pagano Renato Italo , Valenti Bernardo , De Angelis Anna , Avondo Marcella , Pennisi Pietro
Published: September 2011

Twenty lactating Girgentana goats were used to evaluate the effect of morning v. afternoon cutting time of Berseem clover (Trifolium alexandrinum L.) on feed intake, milk yield and milk composition. Goats were randomly divided into two groups of ten animals, receiving 10 kg of fresh Berseem clover cut at 9.00 (AM group) or 16.00 (PM group), respectively; 500 g of concentrate was given individually to goats before offering forage. Feed intake increased (P<0·01) in the PM group (30·5 v. 25·3 g dry matter/kg body weight), associated with the different nutrient content of diets: lower crude protein but higher dry matter, neutral detergent fibre, water soluble carbohydrates (WSC) and total fatty acids in the PM-harvested forage. Milk production, protein and casein content were higher (P<0·05) in the PM group (1415 g/d, 3·25% and 2·42% v. 1277 g/d, 3·15% and 2·33%, respectively), whereas no differences between groups were detected for milk fat, lactose or urea content. Body weight slowly decreased from the start to the end of the experiment, without differences between groups. This study showed an important milk yield responses in Girgentana goats offered afternoon-cut compared with morning-cut Berseem clover, due to a marked increase in WSC in the afternoon-cut forage.
Chrysogorgiafrom the New England and Corner Seamounts: Atlantic–Pacific connections
Authors: Pante Eric , Watling Les
Published: September 2011

Recent exploration of the New England and Corner Seamounts revealed four new species ofChrysogorgia, described here using a combination of molecular and morphological data. These four species are characterized by a sinistral spiral, a character that, with one known exception, has only been reported for Pacific species. In addition, two species have a sclerite composition typical of the Pacific (‘squamosae typicae’). This faunal connection between the Atlantic and the Pacific is confirmed by analysis of the mitochondrialmsh1 gene. The exceptional preservation of specimens collected with remotely operated vehicles allows us to discuss the effect of growth on some morphological characters.
A novel triazolic naphthofuranquinone induces autophagy in reservosomes and impairment of mitosis in Trypanosoma cruzi
Authors: FERNANDES M. C. , DA SILVA E. N. , PINTO A. V. , DE CASTRO S. L. , MENNA-BARRETO R. F. S.
Published: September 2011

Chagas' disease, caused by the protozoan Trypanosoma cruzi, represents a serious health problem in Latin America, and the available chemotherapy, which is based on 2 nitro-derivatives, is not satisfactory. In folk medicine, natural products including naphthoquinones have been employed for the treatment of different parasitic diseases. In the pursuit of alternative drugs for Chagas' disease, we investigated the mechanism of action of the triazolic naphthoquinone (TN; 2,2-dimethyl-3-(4-phenyl-1H-1,2,3-triazol-1-yl)-2,3-dihydronaphtho[1,2-b]furan-4,5-dione), which is the most active compound against T. cruzi trypomastigotes among a series of naphthofuranquinones. TN was active against the 3 parasite forms producing a dose-dependent inhibitory effect. In epimastigotes, TN induced reservosome disruption, flagellar blebbing, Golgi disorganization, the presence of cytosolic concentric membrane structures and abnormal multiflagellar parasites. The treatment also led to the appearance of well-developed endoplasmic reticulum profiles surrounding organelles that associated with an increase in monodansylcadaverine labelling, suggesting autophagy as part of the TN mechanism of action. Interestingly, no ultrastructural damage was detected in the mitochondria of naphthoquinone-treated epimastigotes. Flow cytometric analysis demonstrated an impairment of mitosis, an increase in ROS production and the maintenance of mitochondrial membrane potential. TN could be a good starting point in the investigation of a chemotherapeutic approach for the treatment of Chagas' disease.
Effective elements of cognitive behaviour therapy for psychosis: results of a novel type of subgroup analysis based on principal stratification
Authors: Dunn G. , Fowler D. , Rollinson R. , Freeman D. , Kuipers E. , Smith B. , Steel C. , Onwumere J. , Jolley S. , Garety P. , Bebbington P.
Published: September 2011

Background

Meta-analyses show that cognitive behaviour therapy for psychosis (CBT-P) improves distressing positive symptoms. However, it is a complex intervention involving a range of techniques. No previous study has assessed the delivery of the different elements of treatment and their effect on outcome. Our aim was to assess the differential effect of type of treatment delivered on the effectiveness of CBT-P, using novel statistical methodology.

Method

The Psychological Prevention of Relapse in Psychosis (PRP) trial was a multi-centre randomized controlled trial (RCT) that compared CBT-P with treatment as usual (TAU). Therapy was manualized, and detailed evaluations of therapy delivery and client engagement were made. Follow-up assessments were made at 12 and 24 months. In a planned analysis, we applied principal stratification (involving structural equation modelling with finite mixtures) to estimate intention-to-treat (ITT) effects for subgroups of participants, defined by qualitative and quantitative differences in receipt of therapy, while maintaining the constraints of randomization.

Results

Consistent delivery of full therapy, including specific cognitive and behavioural techniques, was associated with clinically and statistically significant increases in months in remission, and decreases in psychotic and affective symptoms. Delivery of partial therapy involving engagement and assessment was not effective.

Conclusions

Our analyses suggest that CBT-P is of significant benefit on multiple outcomes to patients able to engage in the full range of therapy procedures. The novel statistical methods illustrated in this report have general application to the evaluation of heterogeneity in the effects of treatment.
Spatial receptive field properties of rat retinal ganglion cells
Authors: HEINE WALTER F. , PASSAGLIA CHRISTOPHER L.
Published: September 2011

The rat is a popular animal model for vision research, yet there is little quantitative information about the physiological properties of the cells that provide its brain with visual input, the retinal ganglion cells. It is not clear whether rats even possess the full complement of ganglion cell types found in other mammals. Since such information is important for evaluating rodent models of visual disease and elucidating the function of homologous and heterologous cells in different animals, we recorded from rat ganglion cells in vivo and systematically measured their spatial receptive field (RF) properties using spot, annulus, and grating patterns. Most of the recorded cells bore likeness to cat X and Y cells, exhibiting brisk responses, center-surround RFs, and linear or nonlinear spatial summation. The others resembled various types of mammalian W cell, including local-edge-detector cells, suppressed-by-contrast cells, and an unusual type with an ON–OFF surround. They generally exhibited sluggish responses, larger RFs, and lower responsiveness. The peak responsivity of brisk-nonlinear (Y-type) cells was around twice that of brisk-linear (X-type) cells and several fold that of sluggish cells. The RF size of brisk-linear and brisk-nonlinear cells was indistinguishable, with average center and surround diameters of 5.6 ± 1.3 and 26.4 ± 11.3 deg, respectively. In contrast, the center diameter of recorded sluggish cells averaged 12.8 ± 7.9 deg. The homogeneous RF size of rat brisk cells is unlike that of cat X and Y cells, and its implication regarding the putative roles of these two ganglion cell types in visual signaling is discussed.
Automatic scaling of polar ionograms
Authors: Scotto Carlo , Pezzopane Michael
Published: September 2011

The Istituto Nazionale di Geosifica e Vulcanologia (INGV) software for automatic scaling of ionograms (Autoscala) was improved by introducing a system to identify D region absorption events, spread-F condition (frequency spreading in the F region), and Z-ray propagation. The algorithm was applied to a series of ionograms recorded by the AIS-INGV (Advanced Ionospheric Sounder-INGV) ionosonde installed at the Mario Zucchelli Station (74.7°S, 164.1°E), Terra Nova Bay, Antarctica. Critical cases are shown to illustrate the behaviour of the software.
Density, body size and sex ratio of an indigenous spider along an altitudinal gradient in the sub-Antarctic
Authors: Lee Jennifer E. , Somers Michael J. , Chown Steven L.
Published: September 2011

Although spiders are a diverse and ecologically important group of predators across the sub-Antarctic islands, relatively little is known about their biology. Here we provide data on the abundance, body size variation and sex ratio of an indigenous spider,Myro kerguelenensis, across an altitudinal gradient on Marion Island. In so doing we test explicitly the hypotheses that density will decline with declining resource availability at higher elevations, and that a converse Bergmann body size cline will be found in this species. Density ofM. kerguelenensisdecreased with altitude and ranged from a mean density of 5.3 (SD 3.42) individuals per m2at 50 m a.s.l. to a mean density of 0.83 (SD 1.15) individuals per m2at 600 m a.s.l. Mean female sternum width was 1.39 mm (SD 0.44) and mean male sternum width was 1.40 mm (SD 0.22). No evidence for Bergmann or converse Bergmann clines was found. At increasing altitudes, sex ratios became increasingly female-biased with populations at 600 m a.s.l. comprising 0.87 (SD 0.28) females, on a proportional basis, possibly as a result of resource limitation and an increase in the prevalence of sexual cannibalism. The food web implications of this study are highlighted.
De Gaulle as a Father of Europe: The Unpredictability of the FTA's Failure and the EEC's Success (1956–58)
Authors: WARLOUZET LAURENT
Published: September 2011

The failure of the Free Trade Area (FTA), a British ‘Greater Europe’ free-market project, has often been contrasted with the European Economic Community (EEC)'s rapid success. However, this article claims that the EEC's success was neither logical nor automatic. The FTA project was not bound to failure, but could easily have become the principal institution for European co-operation. Moreover, the French leader, Charles de Gaulle, played such a prominent role in the EEC that he could be described as a new ‘Father of Europe’. Without the EEC, France would certainly have been forced to reach agreement on the FTA, but conversely, without de Gaulle, the EEC would probably have been diluted into a larger FTA.
Beyond War Crimes: Denazification, ‘Obnoxious’ Germans and US Policy in Franco's Spain after the Second World War
Authors: MESSENGER DAVID A.
Published: September 2011

This work links the western Allies’ policy of denazification in occupied Germany to efforts to repatriate German intelligence agents and Nazi Party officials – so-called ‘obnoxious’ Germans – from the neutral states of Europe after the Second World War. Once on German soil, these individuals would be subject to internment and investigation as outlined in occupation policy. Using the situation in Franco's Spain as a case study, the article argues that new ideas of neutrality following the war and a strong commitment to the concept of denazification led to the creation of the repatriation policy, especially within the United States. Repatriation was also a way to measure the extent to which Franco's Spain accepted the Allied victory and the defeat of Nazism and fascism. The US perception was that the continued presence of individual Nazis meant the continued influence of Nazism itself. Spain responded half-heartedly, at best. Despite the fact that in terms of numbers repatriated the policy was a failure, the Spanish example demonstrates that the attempted repatriation of ‘obnoxious’ Germans from neutral Europe, although overlooked, was significant not only as part of the immediate post-war settlement but also in its bearing on US ideas about Nazism, security and perceived collaboration of neutral states like Spain.
SEM Backscattered-Electron Images of Paint Cross Sections as Information Source for the Presence of the Lead White Pigment and Lead-Related Degradation and Migration Phenomena in Oil Paintings
Authors: Keune Katrien , van Loon Annelies , Boon Jaap J.
Published: September 2011

Scanning electron microscopy backscattered-electron images of paint cross sections show the compositional contrast within the paint system. They not only give valuable information about the pigment composition and layer structure but also about the aging processes in the paint. This article focuses on the reading of backscatter images of lead white-containing samples from traditional oil paintings (17th–19th centuries). In contrast to modern lead white, traditional stack process lead white is characterized by a wide particle size distribution. Changes in particle morphology and distribution are indications of chemical/physical reactivity in the paint. Lead white can be affected by free fatty acids to form lead soaps. The dissolution of lead white can be recognized in the backscatter image by gray (less scattering) peripheries around particles and gray amorphous areas as opposed to the well-defined, highly scattering intact lead white particles. The small particles react away first, while the larger particles/lumps can still be visible. Formed lead soaps appear to migrate or diffuse through the semipermeable paint system. Lead-rich bands around particles, at layer interfaces and in the paint medium, are indications of transport. The presence of lead-containing crystals at the paint surface or inside aggregates furthermore point to the migration and mineralization of lead soaps.
Die Bedeutung der Führungskräfte- Kategorisierung für Commitment, Arbeitszufriedenheit und Wohl- befinden unter Berücksichtigung der Geschlechterrollentheorie
Authors: Junker Nina Mareen , Schyns Birgit , Dick Rolf van , Scheurer Sandra
Published: September 2011

Studien zur Bedeutung einer Kategorisierung von Führungskräften hinsichtlich eines Führungsideals und eines Gegen-Ideals weisen bislang ungeklärte Inkonsistenzen vor allem bzgl. der empirischen Relevanz eines Gegen-Ideals auf. Ziel der vorliegenden Studie ist es, hierfür mögliche Erklärungen zu finden. In einer Feldstudie (N = 184) können wir die Relevanz impliziter Führungstheorien für Arbeitszufriedenheit, Commitment und Wohlbefinden der Mitarbeiter sowie eine mediierende Wirkung von Leader-Member Exchange auf diese Beziehungen aufzeigen. Weiterhin untersuchten wir den Einfluss der Geschlechterrolle auf diese Mediation. Der Fit der Führungskraft mit den impliziten Führungstheorien der Mitarbeiter beeinflusst die Arbeitszufriedenheit von Frauen stärker als die von Männern, nicht aber deren Commitment und Wohlbefinden. Die Relevanz der Ergebnisse für Forschung und Praxis wird diskutiert.
Telefonischer Einsatz von Coaching-Methoden zur Unterstützung von Führungskräfte-Workshops
Authors: Hammes Mike , Wieland Rainer , Rosen Patricia H.
Published: September 2011

In diesem Beitrag wird mit dem Mentoring-Assistenz-Programm (MAP) ein Interventionsinstrument zur Unterstützung von Führungskräfte-Workshops vorgestellt und evaluiert. Ziel des Mentoring-Assistenz-Programms ist es, Teilnehmende darin zu unterstützen, Probleme bei der Umsetzung gesundheitsförderlichen Führungsverhaltens in individuelle, praktikable Lösungsansätze zu überführen. Dies geschieht durch telefonische Beratung, die sich an Führungskräfte-Workshops anschließt. Ausgangspunkt ist dabei die Annahme, mithilfe von Coaching-Methoden ergebnisorientierte Problem- und Selbstreflexion anregen zu können. Daher werden hauptsächlich solche Methoden in den telefonischen Beratungen angewendet. Grundlage des vorliegenden Beitrags sind Erfahrungen mit dem Instrument im Rahmen eines Präventionsprogramms zur betrieblichen Gesundheitsförderung bezüglich Muskel-Skelett-Beschwerden. Zur Evaluation werden Ergebnisse einer qualitativen Inhaltsanalyse vorgestellt, in der 53 Gesprächsprotokolle berücksichtigt wurden. Ergebnisse eines Wissenstest zu gesundheitsförderlichem Führungsverhalten werden zur quantitativen Evaluation berichtet. Möglichkeiten zur Übertragung des Instruments auf weitere Einsatzfelder werden diskutiert.
Erfassung von Mentoring-Unterstützung
Authors: Schneider Paula B. , Witzki Alexander , Blickle Gerhard
Published: September 2011

Mentor-Protegé-Beziehungen haben in den vergangenen Jahren nicht nur in der internationalen Forschung, sondern auch in der betrieblichen Praxis in Deutschland große Beachtung gefunden. Für den deutschen Sprachraum liegt allerdings bisher noch kein validiertes Instrument zur Erfassung von Mentoring-Unterstützung am Arbeitsplatz vor. Im Rahmen der vorliegenden Arbeit wird über die Validierung des international weit verbreiteten Mentor Role Instruments ( Ragins & McFarlin, 1989 , 1990 ) berichtet. Die Studie hatte ein längsschnittliches Design mit drei Erhebungswellen. Befragt wurden Nachwuchskräfte mit wirtschaftlichen Hochschulabschlüssen (N = 338), ihre Mentoren (N = 264) und ihre Kollegen (N = 275). Im Rahmen des Validierungskonzeptes wurde die Binnenstruktur des Mentor Role Instruments, die Veränderung der mentoralen Unterstützung im Laufe der Beziehung und die Konvergenz von Protegé, Mentor und Kollege in Bezug auf das Ausmaß der Unterstützung überprüft. Die Ergebnisse stützen sowohl die differenziertere Elf-Faktoren-Struktur des Erhebungsinstrumentes als auch die zwei Dimension, karrierebezogene vs. psychosoziale Mentoring-Unterstützung, zweiter Ordnung sowie die Konstruktvalidität des Verfahrens. Das Instrument ist daher für den Einsatz in Wissenschaft und Praxis geeignet.
The Need Inventory of Sensation Seeking (NISS)
Authors: Roth Marcus , Hammelstein Philipp
Published: September 2011

Based on the conception of sensation seeking as a need rather than a temperamental trait ( Hammelstein, 2004 ), we present a new assessment method, the Need Inventory of Sensation Seeking (NISS), which is considered to assess a motivational disposition. Three studies are presented: The first examined the factorial structure and the reliability of the German versions of the NISS; the second study compared the German and the English versions of the NISS; and finally, the validity of the NISS was examined in a nonclinical study and compared to the validity of conventional methods of assessing sensation seeking (Sensation Seeking Scale – Form V; SSS-V). Compared to the SSS-V, the NISS shows better reliability and validity in addition to providing new research possibilities including application in experimental areas.
The Schoolwork Engagement Inventory
Authors: Salmela-Aro Katariina , Upadaya Katja
Published: September 2011

This study introduces the Schoolwork Engagement Inventory (EDA), which measures energy, dedication, and absorption with respect to schoolwork. Structural equation modeling was used to assess the validity and reliability of the inventory among students attending postcomprehensive schools. A total of 1,530 (769 girls, 761 boys) students from 13 institutions (six upper-secondary and seven vocational schools) completed the EDA 1 year apart. The results showed that a one-factor solution had the most reliability and fitted best among the younger students, whereas a three-factor solution was most reliable and fit best among the older students. In terms of concurrent validity, depressive symptoms and school burnout were inversely related, and self-esteem and academic achievement were positively associated with EDA. Boys and upper-secondary-school students experienced lower levels of schoolwork engagement than girls and vocational-school students.
Lineage commitments: emphasis on embryonic–extraembryonic interfaces
Authors: Downs Karen M
Published: September 2011

The EMBO Workshop on ‘Lineage Commitments: Emphasis on Embryonic–Extraembryonic Interfaces’, held in May 2011, demonstrated that embryonic and extraembryonic tissues play early and significant interacting roles that mutually promote each other's further and correct deployment within the mammalian conceptus.