bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase behavior of semiflexible polymer chains
Authors: Padmanabhan Venkat , Kumar Sanat K. , Yethiraj Arun
Published: April 2008

Monte Carlo simulations were performed on semiflexible polymer chains with the goal of delineating their isotropic-nematic (IN) and gas-liquid coexistence envelopes. The chain monomers are spherical beads that interact via a square-well potential with all other beads. Bonded beads are connected by strings chosen so that bond length varies between 1.01σ and 1.05σ (where σ is the hard sphere diameter). The stiffness of the molecules is controlled via a potential between beads separated by two bonds; this potential restricts the distance between these beads to be between 2.02σ and 2.1σ. The vapor-liquid coexistence and IN coexistence curves are obtained using computer simulations. An IN transition is found for 10⩽Nb<30. Both the density at which the IN transition occurs and the location of the gas-liquid coexistence go through a maximum with increasing Nb. For longer chains, behavior expected from theory is found and both of these coexisting densities decrease with increasing length.
A method to retrieve optical and geometrical characteristics of three layer waveguides from m-lines measurements
Authors: Schneider T. , Leduc D. , Lupi C. , Cardin J. , Gundel H. , Boisrobert C.
Published: April 2008

We consider three layer optical waveguides and present a method to measure simultaneously the refractive index and the thickness of each layer with m-lines spectroscopy. We establish the three layer waveguide modal dispersion equations and describe a numerical method to solve these equations. The accuracy of the method is evaluated by numerical simulations with noisy data and experimentally demonstrated using a PZT thin film placed between two ZnO layers.
Electron beam charging of insulators with surface layer and leakage currents
Authors: Cornet N. , Goeuriot D. , Guerret-Piécourt C. , Juvé D. , Tréheux D. , Touzin M. , Fitting H.-J.
Published: April 2008

The electron beam induced self-consistent charge transport in layered insulators (here, bulk alumina covered by a thin silica layer) is described by means of an electron-hole flight-drift model and an iterative computer simulation. Ballistic secondary electrons and holes, their attenuation and drift, as well as their recombination, trapping, and detrapping are included. Thermal and field-enhanced detrapping are described by the Poole–Frenkel effect. Furthermore, an additional surface layer with a modified electric surface conductivity is included which describes the surface leakage currents and will lead to particular charge incorporation at the interface between the surface layer and the bulk substrate. As a main result, the time-dependent secondary electron emission rate σ(t) and the spatial distributions of currents j(x,t), charges ρ(x,t), field F(x,t), and potential V(x,t) are obtained. For bulk full insulating samples, the time-dependent distributions approach the final stationary state with j(x,t)=const=0 and σ=1. In the case of a measurable surface leakage current, the steady stationary state is reached for σ<1. First measurements are extended to the sample current measurement including nonstationary components of charge incorporation and polarization as well as dc components of leakage currents.
Design of efficient focused surface acoustic wave devices for potential microfluidic applications
Authors: Sankaranarayanan Subramanian K. R. S. , Bhethanabotla Venkat R.
Published: April 2008

Focused interdigital transducers (F-IDTs) patterned on surfaces of piezoelectric substrates can be used to generate surface acoustic waves (SAW) with high intensity and high beam-width compression ratio. A three dimensional coupled field finite element model of a focused SAW (F-SAW) device with interdigital transducers shaped as concentric circular arcs based on a YZ LiNbO3 substrate is developed in this study. This model was utilized to investigate the effect of geometric shape of transducers on the focusing properties of F-IDTs to identify the optimal design for potential microfluidic applications. The transducer design parameters investigated in the current study include number of finger pairs, degree of arc, geometric focal length, and wavelength of F-SAW. The transient response of the device on application of impulse and ac electrical inputs at the transmitting FIDT fingers were utilized to deduce the device frequency response and propagation characteristics of F-SAWs, respectively. The influence of applied input voltage on the propagation characteristics is also investigated. The insertion loss calculated for the various F-IDT designs was used to identify the optimal transducer configuration for sensing and microfluidic applications. The focusing properties as well as the wave propagation characteristics for the various F-IDT designs were evaluated in terms of the amplitude field and displacement contours generated in regions close to and at the focal point. Comparison with a conventional SAW device operating at megahertz frequency range and uniform IDT design is also made. Our study indicates that the focusing property of the device is significantly influenced by the geometric shape of the F-IDTs. The streaming phenomenon induced by F-SAW propagation, when in contact with a fluid medium, is discussed in detail. The simulated amplitude fields generated using ac analysis for the various designs in conjunction with wave propagation parameters derived using perturbational techniques such as Campbell–Jones are utilized to calculate the streaming forces and velocities based on successive approximation technique applied to Navier–Stokes equation (Nyborg’s theory). The maximum streaming force and velocity are obtained at the focal point of the F-SAW device. The magnitude of the generated streaming force and induced streaming velocity are strongly influenced by the transducer configurations. Based on the simulation results of this study, we provide guidelines for designing various F-IDTs to suite desired applications. F-SAW devices operating with higher applied input voltages and at higher frequencies, with optimal geometric length and larger degree of arc, are best suited for actuation and fluid microtransport.
Maps on states preserving the relative entropy
Authors: Molnár Lajos
Published: April 2008

Let H be a finite dimensional Hilbert space. The aim of this short note is to prove that every bijective map on the space S(H) of all density operators on H which preserves the relative entropy is of the form ϕ(ρ)=UρU* with some unitary or antiunitary operator U on H.
Microwave, magnetic, and structural properties of nanocrystalline exchange-coupled Ni11Co11Fe66Zr7B4Cu1 films for high frequency applications
Authors: Yoon S. D. , Baraskar A. K. , Geiler A. , Yang A. , Pettiford C. , Sun N. X. , Goswami R. , Willard M. A. , Vittoria C. , Harris V. G.
Published: April 2008

Nanocrystalline structured films of the alloy Ni11Co11Fe66Zr7B4Cu1 were deposited by pulsed laser ablation deposition onto fused quartz substrates. A substrate temperature of 300°C was found to produce films consisting of body-centered-cubic (bcc) metallic grains suspended in an amorphous matrix. The bcc grain size ranged from 5–8nm for substrate temperatures up to 300°C. Measured values of coercivity were consistently below 4Oe for films having a saturation magnetization, as 4πMS, of ∼16kG with in-plane uniaxial anisotropy fields of 25to30Oe. The ferromagnetic resonance peak-to-peak derivative linewidth was measured to be 34Oe at a frequency of 9.61GHz. The zero magnetic field ferromagnetic resonance occurred at ∼2GHz. These films exhibit soft magnetic properties, high saturation induction, low microwave loss, and the structural stability desirable for thin film inductor applications.
Characterization of the electrosprays of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide in vacuum
Authors: Gamero-Castaño Manuel
Published: April 2008

The electrosprays of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide are composed of a complex mixture of ions and charged droplets, which can be analyzed to determine the structure of the beam and infer significant features of the electrohydrodynamic atomization. In particular, we use a combination of retarding potential and time of flight techniques to study these beams and are able to quantify the voltage drop along the cone jet, together with the velocity and diameter of the jet at the breakup location, confirm the strong influence of viscosity and electrification in the breakup, show that the electric field in and near the Taylor cone tip is insensitive to external electrostatic parameters, and study the spatial distribution of ions and droplets, whereby the paradoxical absence of ions in the outmost region of the beam is established. The research described in this article can be exploited in the modeling of capillary instability of charged jets: testing the results of these models is difficult, especially when nanojets are involved, and our findings and techniques provide the experimental support required by the theoretical activity. The present research is also applicable to the modeling of colloid thruster beams.
First-principles study of electronic and optical properties in wurtzite Zn1−xCdxO
Authors: Zhang X. D. , Guo M. L. , Li W. X. , Liu C. L.
Published: April 2008

We have performed a first-principles study to evaluate the electronic and optical properties of wurtzite Zn1−xCdxO up to x=0.25. We have employed the Perdew–Burke–Ernzerhof form of the generalized gradient approximation within the framework of density functional theory. Calculations have been carried out in different configurations. With increasing Cd concentrations, the band gap of Zn1−xCdxO is decreased due to the increase of s states in the conduction band. The results of the imaginary part of the dielectric function ε2(ω) indicate that the optical transition between O 2p states in the highest valence band and Zn 4s states in the lowest conduction band has shifted to the low energy range as the Cd concentrations increase. Besides, the optical band gap decreases from 3.2 to 2.84 eV with increasing Cd concentrations from 0 to 0.25. Meanwhile, the bowing parameter b, which has been obtained by fitting the results of the optical band gap, is about 1.21 eV. The optical constants of pure ZnO and Zn0.75Cd0.25O, such as optical conductivity, loss function, refractive index, and reflectivity, are discussed.
Low-temperature emission in dilute GaAsN alloys grown by metalorganic vapor phase epitaxy
Authors: Bentoumi G. , Yaïche Z. , Leonelli R. , Beaudry J.-N. , Desjardins P. , Masut R. A.
Published: April 2008

We have investigated the optical emission from GaAs1−xNx epilayers with 4.3×10−4<x<0.012. The samples were grown on GaAs(001) substrates by metal-organic vapor phase epitaxy using dimethylhydrazine as the nitrogen precursor. We find that the incorporation of nitrogen in GaAs generates deep radiative centers at around 250meV below the GaAsN band gap. The defects associated with these centers can be eliminated through an optimization of the growth temperature and reactor pressure, and by postgrowth annealing at 700°C. We also find that, contrary to what was suggested by Makimoto et al. [Appl. Phys. Lett. 70, 2984 (1997)], the near-gap emission located close to 25meV below the gap is not related to a free-to-bound transition even in the samples with the lowest nitrogen content. Rather, we associate this emission to excitons bound to overlapping nitrogen clusters.
The Thomson deflectometer: A novel use of the Thomson spectrometer as a transient field and plasma diagnostic
Authors: Ter–Avetisyan S. , Schnürer M. , Nickles P. V. , Sokollik T. , Risse E. , Kalashnikov M. , Sandner W. , Priebe G.
Published: April 2008

Laser accelerated proton beams have been used for field characterization in expanding plasmas. The Thomson parabola spectrometer, as a charged particles analyzer, also allows precise measurement of the charged particles’ trajectories. The proton’s deflections by fast changing plasma fields can be measured with the new design of the Thomson parabola spectrometer and, therefore, it can be applied for proton deflectometry. It is shown that from resulting spectrograms the plasma field dynamics can be reconstructed with high temporal resolution. In a proof-of-principle experiment, a weakly relativistic plasma expansion is studied as an example.
Survey of the potential of emerging wireless technologies to improve telecommunication services in remote Australian settlements
Authors: Abolhasan Mehran , Wright Alyson
Published: April 2008

Providing efficient yet cost effective telecommunication systems to Aboriginal people living in remote locations has proven to be a challenging task. This is primarily due to low population density and distance from major service centres. Extending high-capacity telecommunications infrastructure to these people would incur high costs of installation, maintenance and administration without significant financial returns. The cost of services such as cabled phone lines to all houses, satellite and wireless cellular networks are often unaffordable for people in remote settlements, and, as a result, the provision of telecommunication services is often subsidised by the government.
New wireless standards and products are being developed which could provide broadband-type network connections to large areas at an affordable price. This paper describes these new standards and products and their potential applications in rural and remote regions. There is also a comparison of their transmission requirements, cost, performance and coverage with several currently available technologies.
Fire and its management in central Australia
Authors: Edwards G. P. , Allan G. E. , Brock C. , Duguid A. , Gabrys K. , Vaarzon-Morel P.
Published: April 2008

Over the last 130 years, patterns of land use in central Australia have altered dramatically, and so too have fire regimes and fire management objectives. Although Aboriginal people still have tenure over large parts of the landscape, their lifestyles have changed. Most Aboriginal people now live in towns and settlements and, although fire management is still culturally important, the opportunities for getting out on country to burn are constrained. Large parts of the landscape are now used for pastoral production. Under this land use the management objective is often one of fire exclusion. The other large-scale land use is for conservation. Here, fire management has a greater focus on conserving biodiversity using various burning strategies. In this paper we explore contemporary fire regimes in central Australia. Widespread fire events are found to be associated with two or more consecutive years of above-average rainfall. Although most of the fires linked with these high rainfall periods occur during the warmer months, in recent times these fires have exhibited increased activity during the cooler months. There has been a concomitant increase in the number and size of these fires and in the number of fires associated with roads. We also explored current fire management issues on Aboriginal, pastoral and conservation lands. Current fire management goals are not being wholly met on any of these land tenures in central Australia and social conflict sometimes emerges as a result. There are overlaps in management aims, issues and the under-achievement of desired outcomes across the land tenures which lead us to five key recommendations for improving fire management outcomes in central Australia. We finish with some comments on associated opportunities for livelihood enhancement based on the management of fire.
Applying the sustainable livelihoods approach in Australian desert Aboriginal development
Authors: Davies Jocelyn , White Janelle , Wright Alyson , Maru Yiheyis , LaFlamme Michael
Published: April 2008

The sustainable livelihoods approach is widely used in rural development internationally but has been little applied in Australia. It is a framework for thinking and communicating about factors that impact on the livelihoods of individuals and families including their health, well being and income and the maintenance of natural resource condition. The approach aims to promote a systemic understanding of how multiple variables impact on local people’s livelihoods. Three case studies are outlined, that highlight its potential as a tool for collaborative engagement of researchers, local people and other stakeholders, to promote sustainability of Aboriginal livelihood systems in remote desert Australia and to contribute to improved understanding of the dynamics of regional socio-ecological systems.
The shape of Aboriginal learning and work opportunities in desert regions
Authors: Young Metta , Guenther John
Published: April 2008

Abstract Education is one of the most powerful instruments for reducing poverty and inequality, and lays a foundation for sustained economic growth. Aboriginal peoples of Australia experience ‘overwhelming’ disadvantages across every indicator of social and economic well being when compared with non-Aboriginal peoples. This disadvantage is experienced across all sectors of education, and although Aboriginal students are participating at high rates in vocational education and training, their pass rates and qualification outcomes remain well below those of non-Aboriginal Australians. This paper maps the participation and outcomes for Aboriginal desert dwellers in the vocational education and training sector and relates these to factors such as: (1) compulsory school access, (2) remote area labour markets, (3) the state of housing and infrastructure on discrete desert settlements, and (4) the policy and program initiatives influencing land tenure, income security and labour force status. The provision of education services across desert regions epitomises the tensions generated when the drivers of desert living – remoteness, dispersed sparse and mobile populations, variable climate, geography, cultures, languages and histories – interact with the differing factors that shape mainstream vocational education. Although innovations in program delivery more consistent with learner needs and aspirations can and do emerge, they are often framed as pilot projects or materialise in parallel program interventions such as youth work or land care. This paper explores the nature of these tensions and identifies the characteristics of educational interventions that can improve outcomes for Aboriginal desert dwellers no matter where they choose to live.
Linking desert businesses: the impetus, the practicalities, the emerging pay-offs, and building on the experiences
Authors: Taylor Joy , Ffowcs-Williams Ifor , Crowe Mike
Published: April 2008

Small businesses in desert Australia are disadvantaged by remoteness from suppliers and markets, workforce problems, and limited opportunities to explore alliances across the desert. This paper outlines an initiative to support and encourage capacity building in remote desert centres and to create networks to overcome the isolation experienced by desert-based small and medium-sized enterprises. Building on existing local initiatives and seizing the opportunities offered by a range of new information and communication technologies (ICT), businesses are linked together to explore the benefits of networking, to identify possible synergies and opportunities for collaboration, to gain practical ICT and networking skills and confidence in the processes, and create real outcomes for their business.
The initiative began with a pilot project focused on training and mentoring business owners and managers in business clustering. In addition to education and training outcomes, this pilot produced more outcomes for the participating businesses than had been anticipated. In the final year $7 million of new business was reported. Many businesses embraced this way of working together to improve competitiveness; as a consequence the networks have continued to operate beyond the life of the pilot project. Several case studies are presented to demonstrate how ICT has been used for the transfer of ideas and knowledge, for collaboration, and to open new commercial opportunities for businesses that arose as a direct result of their participation.
Proof of concept has been demonstrated in the value to businesses of this approach to long-distance inter-business cooperation and networking. The paper outlines key findings from the pilot project, including the needs for an appropriate pace of development, mix of technologies used, nurturing of business champions, flexibility, local facilitation, and real business outcomes, among others. These findings are being used to inform future developments in long-distance, cross-border business networking internationally and an expanded project involving nine regions of desert Australia.
Implementing risk management for water supplies: a catalyst and incentive for change
Authors: Grey-Gardner Robyn
Published: April 2008

Water management in small Aboriginal settlements in remote Australia is typified by technology-driven approaches where knowledge, decision-making and responsibility reside with organisations and agencies outside the settlement. This conventional approach has been a disincentive to active involvement by residents in managing the hazards and risks of their own water supply, despite the apparent presence of knowledge and skills at the settlement level.
This paper outlines lessons from the Desert Knowledge Cooperative Research Centre’s Remote Community Water Management Project. The aim of the 2-year project was to identify a replicable model and process for sustainable small scale water supply management in remote Aboriginal settlements. The approach was a practical departure from viewing water quality in isolation from the other water supply issues such as water quantity, affordability, additional resources and aspirations. The risk management model that was developed and utilised is presented and the significant factors that enabled a holistic approach to water supply management are discussed.
The dynamic combination of participatory processes and an iterative approach enabled effective project implementation, and created an environment of continual improvement. Critical elements of the project implementation are described, in particular, the sequencing of activities and the identification of incentives and drivers for increasing self reliance. The social capital within the case study settlements is explored as a critical attribute for a sustainable management program or change process.
The model developed during the project provides a structure for expanding the approach to, for example, a regional water management strategy. The opportunities for expansion are further enhanced by the practices of developing appropriate and transferable tools. The integration of livelihood aspirations within institutions of policy and water risk management practice is endorsed for effective and sustainable local water management.
Up-regulation of a cellular protein at the translational level by a retrovirus
Authors: Yoshimura Fayth K. , Luo Xixia , Zhao Xiaoqing , Gerard Herve C. , Hudson Alan P.
Published: April 2008

Mink cell focus-forming (MCF) murine leukemia viruses (MLVs) are the etiologic agent of thymic lymphoma in mice. We have observed previously that superinfection by MCF13 MLV of certain cell types, such as preleukemic thymic lymphocytes and cultured mink epithelial cells, results in the accumulation of the viral envelope precursor polyprotein, leading to the induction of endoplasmic reticulum (ER) stress. In this study, we demonstrate that the induction of ER stress by MCF13 MLV infection results in an increase in the phosphorylation of the α-subunit of eukaryotic initiation factor 2. In cells in which this occurs, we have detected an up-regulation of the cellular inhibitor of apoptosis protein 1 (c-IAP1). The results of real-time RT-PCR quantification of message levels and protein turnover assays indicate that up-regulation of c-IAP1 occurs at the translational level. Elevation of c-IAP1 levels at a posttranscriptional step was detectable in MCF13 MLV-induced thymic lymphomas and chronically infected mink epithelial cells. The ability of a simple retrovirus to regulate cellular gene expression at the translational level may be an important mechanism that contributes to pathogenesis.
Noninvasive molecular imaging of small living subjects using Raman spectroscopy
Authors: Keren S. , Zavaleta C. , Cheng Z. , de la Zerda A. , Gheysens O. , Gambhir S. S.
Published: April 2008

Molecular imaging of living subjects continues to rapidly evolve with bioluminescence and fluorescence strategies, in particular being frequently used for small-animal models. This article presents noninvasive deep-tissue molecular images in a living subject with the use of Raman spectroscopy. We describe a strategy for small-animal optical imaging based on Raman spectroscopy and Raman nanoparticles. Surface-enhanced Raman scattering nanoparticles and single-wall carbon nanotubes were used to demonstrate whole-body Raman imaging, nanoparticle pharmacokinetics, multiplexing, and
in vivo
tumor targeting, using an imaging system adapted for small-animal Raman imaging. The imaging modality reported here holds significant potential as a strategy for biomedical imaging of living subjects.
Four-thousand-year-old gold artifacts from the Lake Titicaca basin, southern Peru
Authors: Aldenderfer Mark , Craig Nathan M. , Speakman Robert J. , Popelka-Filcoff Rachel
Published: April 2008

Artifacts of cold-hammered native gold have been discovered in a secure and undisturbed Terminal Archaic burial context at Jiskairumoko, a multicomponent Late Archaic–Early Formative period site in the southwestern Lake Titicaca basin, Peru. The burial dates to 3776 to 3690 carbon-14 years before the present (2155 to 1936 calendar years B.C.), making this the earliest worked gold recovered to date not only from the Andes, but from the Americas as well. This discovery lends support to the hypothesis that the earliest metalworking in the Andes was experimentation with native gold. The presence of gold in a society of low-level food producers undergoing social and economic transformations coincident with the onset of sedentary life is an indicator of possible early social inequality and aggrandizing behavior and further shows that hereditary elites and a societal capacity to create significant agricultural surpluses are not requisite for the emergence of metalworking traditions.
Reproductive conflict and the separation of reproductive generations in humans
Authors: Cant Michael A. , Johnstone Rufus A.
Published: April 2008

An enduring puzzle of human life history is why women cease reproduction midway through life. Selection can favor postreproductive survival because older females can help their offspring to reproduce. But the kin-selected fitness gains of helping appear insufficient to outweigh the potential benefits of continued reproduction. Why then do women cease reproduction in the first place? Here, we suggest that early reproductive cessation in humans is the outcome of reproductive competition between generations, and we present a simple candidate model of how this competition will be resolved. We show that among primates exhibiting a postreproductive life span, humans exhibit an extraordinarily low degree of reproductive overlap between generations. The rapid senescence of the human female reproductive system coincides with the age at which, in natural fertility populations, women are expected to encounter reproductive competition from breeding females of the next generation. Several lines of evidence suggest that in ancestral hominids, this younger generation typically comprised immigrant females. In these circumstances, relatedness asymmetries within families are predicted to give younger females a decisive advantage in reproductive conflict with older females. A model incorporating both the costs of reproductive competition and the benefits of grandmothering can account for the timing of reproductive cessation in humans and so offers an improved understanding of the evolution of menopause.
Son-biased sex ratios in the 2000 United States Census
Authors: Almond Douglas , Edlund Lena
Published: April 2008

We document male-biased sex ratios among U.S.-born children of Chinese, Korean, and Asian Indian parents in the 2000 U.S. Census. This male bias is particularly evident for third children: If there was no previous son, sons outnumbered daughters by 50%. By contrast, the sex ratios of eldest and younger children with an older brother were both within the range of the biologically normal, as were White offspring sex ratios (irrespective of the elder siblings' sex). We interpret the found deviation in favor of sons to be evidence of sex selection, most likely at the prenatal stage.
Id1 cooperates with oncogenic Ras to induce metastatic mammary carcinoma by subversion of the cellular senescence response
Authors: Swarbrick Alexander , Roy Emie , Allen Thaddeus , Bishop J. Michael
Published: April 2008

Recent evidence demonstrates that senescence acts as a barrier to tumorigenesis in response to oncogene activation. Using a mouse model of breast cancer, we tested the importance of the senescence response in solid cancer and identified genetic pathways regulating this response. Mammary expression of activated Ras led to the formation of senescent cellular foci in a majority of mice. Deletion of the p19ARF, p53, or p21WAF1tumor suppressors but not p16INK4aprevented senescence and permitted tumorigenesis. Id1 has been implicated in the control of senescencein vitro, and elevated expression of Id1 is found in a number of solid cancers, so we tested whether overexpression of Id1 regulates senescencein vivo. Although overexpression of Id1 in the mammary epithelium was not sufficient for tumorigenesis, mice with expression of both Id1 and activated Ras developed metastatic cancer. These tumors expressed high levels of p19Arf, p53, and p21Waf1, demonstrating that Id1 acts to make cells refractory to p21Waf1-dependent cell cycle arrest. Inactivation of the conditional Id1 allele in established tumors led to widespread senescence within 10 days, tumor growth arrest, and tumor regression in 40% of mice. Mice in which Id1 expression was inactivated also exhibited greatly reduced pulmonary metastatic load. These data demonstrate that established tumors remain sensitive to senescence and that Id1 may be a valuable target for therapy.
Employing nifedipine as a tocolytic agent prior to external cephalic version
Authors: SALIM RAED , ZAFRAN NOAH , NACHUM ZOHAR , EDELSTEIN SHMUEL , SHALEV ELIEZER
Published: April 2008

Background. External cephalic version (ECV) is accepted as a means of reducing the rate of breech presentation at term. Routine use of tocolysis prior to an ECV has been described to increase its success rate. The study's objective was to evaluate the efficacy of oral nifedipine as a tocolytic agent prior to ECV, and to compare it with intravenous ritodrine (IR). Methods. Women with breech presentation at term considered suitable for ECV were given nifedipine prior to the procedure. The success rate was compared to a cohort of women who underwent an ECV attempt at our department during the years 1999–2002 using IR prior to the procedure. Power analysis indicated that 70 women were needed in each group to detect a difference of 25% from our baseline success rate of 50%. Results. Seventy‐six women receiving nifedipine before their ECV attempt were compared to 90 women who received IR. Age, parity, gestational age at ECV, type of breech, placental location, fetal weight, and gestational age at delivery were not different between the groups. The overall success rate was 54% and 50% in the nifedipine and ritodrine groups respectively (p = 0.6). The success rate among primiparous women was 35% and 29% respectively (p = 0.8). The success rate among multiparous women was 64% and 63% respectively (p = 1.0). The success rate was statistically different between primiparous and multiparous women in each group (p<0.05). Conclusion. Oral nifedipine may be as effective as IR when administered before ECV.
Attitudes towards cesarean section in a nationwide sample of obstetricians and gynecologists
Authors: GUNNERVIK CHRISTINA , SYDSJÖ GUNILLA , SYDSJÖ ADAM , EKHOLM SELLING KATARINA , JOSEFSSON ANN
Published: April 2008

Objective. The Swedish cesarean section (CS) rate has increased dramatically over the last decades, but remains relatively low compared to several other countries in the Western world. The reasons for this continuous increase are multifactorial and difficult to investigate. That pregnant women are demanding CS more frequently does not appear to be the major explanatory factor for the increasing CS rate. Since Swedish CS rates are relatively low, it is important to study attitudes to CS in a nationwide population of Swedish obstetricians and gynecologists in order to determine the possible concerns of this group. Methods. In 2006, a study‐specific questionnaire was created and posted to Swedish obstetricians and gynecologists. In total, 1,280 obstetricians and gynecologists received a questionnaire and replied with a response rate of 66%. Results. In general, older and longer work experience physicians had a more positive attitude towards providing CS on maternal request or elective CS for women who fear vaginal delivery. In addition, these colleagues were more positive in expressing their belief that elective CS is as safe as vaginal delivery for the mother and her child. The main difference between female and male physicians was that males were more positive toward providing CS on maternal request (p <0.001). Conclusion. We have shown that female physicians differ from their male colleagues in their attitudes toward providing CS on maternal request. Female physicians were more reluctant than males to provide CS on maternal request.
Early childhood development in Africa: Interrogating constraints of prevailing knowledge bases
Authors: Pence Alan R. , Marfo Kofi
Published: March 2008

The past two decades have been characterized by renewed attention to the importance of early childhood development (ECD) policies and services in the world's richest and most industrialized countries. During the same period, we have witnessed unprecedented efforts to place ECD policies on the national development planning agenda of the economically less advantaged countries of the Majority World. This paper is premised on the concern that the purposes that have led bilateral and multilateral international agencies to promote and support ECD services in Africa may also be paving the way for uncritical adoption of program and service delivery models grounded in value systems and knowledge bases that may not be appropriate for the continent. We present two critiques to highlight the dangers of ignoring the sociocultural contexts of the knowledge bases that inform ECD policies and practices. We describe one capacity‐building effort, under the auspices of the Early Childhood Development Virtual University (ECDVU), to promote culturally relevant knowledge and prepare leadership personnel for Africa's emerging ECD movement. Finally, based on an exercise designed for an ECDVU cohort to engage and reflect on critiques of mainstream research and theorizing on child development, we share insights that are suggestive of the ways in which African perspectives can contribute to and enrich a global knowledge base on child development.
Mapping an HIV/STD prevention curriculum for Zambian in‐school settings
Authors: Mpofu Elias , Lawrence Frank , Ngoma Mary Shilalukey , Siziya Seter , Malungo Jacob R. S.
Published: March 2008

HIV/AIDS poses grave risk to human development in sub‐Saharan Africa. Evidence‐based interventions that are rooted in local culture could help efforts to prevent threats to human development from HIV/AIDS. We used concept mapping (Concept System, 2006) to construct the components and content of a locally developed HIV/AIDS curriculum for use by secondary schools in Lusaka, Zambia. Participants were school counsellors (n = 14), youth health program officers (n = 7), and regular education teachers (n = 3) from the education, health, and youth development agencies in Lusaka, Zambia (males = 11; females = 13; mean age 38; SD = 15 years). Concept mapping yielded six statement clusters defining preliminary components of a locally grounded in‐school HIV/AIDS prevention curriculum and the content items that define these components: (1) life skills education (18 items), (2) sexuality and reproductive health (10 items), (3) treatment, care and support (13 items), (4) counselling (12 items), (5) basic facts about HIV/AIDS (11 items), and (6) dissemination of information about HIV/AIDS (11 items). Zambian locally constructed constructs for an HIV/STD prevention curriculum overlap those promoted by public health programs in the country and internationally.
Globalization and its discontents: Challenges to developmental theory and practice in Africa
Authors: Super Charles M. , Harkness Sara
Published: March 2008

The three contributions to this Special Section on Culture and Human Development are summarized and critiqued. In considering the nature of contemporary psychological science, as well as applications to early childhood care and development, education to prevent HIV/AIDS, and formal academic education, the various authors are in general agreement on the limitations of current knowledge as it applies to African populations. There is also a common focus on the promise of scientific procedures that take seriously the importance of local understandings, institutions, and social settings.
Psychology and modern life challenges: The 2nd Middle East and North Africa Regional Conference of Psychology, Amman, Jordan, 2007
Authors: Knowles Michael , Sabourin Michel
Published: March 2008

The Second Middle East and North Africa Regional Conference of Psychology was held in Amman from 27 April – 1 May 2007 under the Royal Patronage of Her Majesty Queen Rania Al‐Abdullah and the auspices of the International Union of Psychological Science, the International Association of Applied Psychology, and the International Association of Cross‐Cultural Psychology. It was hosted by the Jordanian Psychological Association whose President was Dr. Asaad Zuby. The President of the Conference and the Local Organizing Committee was Dr. Adnan Farah, the Chair of the Scientific Program Committee was Dr. Mohammad Rimawi, and the Chair of the Regional Advisory Committee was Dr. Marwan Dwairy. The Conference succeeded in attracting participants from 28 countries, including 15 from the Middle East and North Africa region. The Scientific Program explored ways and means to promote the role of psychology in meeting life challenges at regional and international levels. The Conference concluded with the signing of a formal Declaration which called upon governments, academic and professional institutions and organizations, non‐governmental organization and other civil society groups, and the United Nations, to work together and to make every possible effort individually and collectively to achieve these goals.
Explaining the Rise of ‘Human Rights’ in Analyses of Sino-African Relations
Authors: Breslin Shaun , Taylor Ian
Published: April 2008

Popular perceptions of China and its global role are often shaped by two words: ‘made in’. Yet this vision of China that focuses primarily on Beijing as a coming economic superpower is relatively new, and it is not that long ago that two other words tended to dominate debates on and discourses of China: ‘human rights’. To be sure, real interest in human rights in China was never the only issue in other states’ relations with China, nor consistently pursued throughout the years (Nathan, 1994). Nor did human rights totally subsequently disappear from the political agenda.
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Nevertheless, the rhetorical importance of human rights - perhaps best epitomised by the narrow defeat of resolutions condemning Chinese policy in 1995 at the Human Rights Council in Geneva - stands in stark contrast to the relative silence thereafter as the bottom line of most states’ relations with Beijing took on ever greater economic dimensions.
Myt1 protein kinase is essential for Golgi and ER assembly during mitotic exit
Authors: Nakajima Hiroyuki , Yonemura Shigenobu , Murata Masayuki , Nakamura Nobuhiro , Piwnica-Worms Helen , Nishida Eisuke
Published: April 2008

Myt1 was originally identified as an inhibitory kinase for Cdc2 (Cdk1), the master engine of mitosis, and has been thought to function, together with Wee1, as a negative regulator of mitotic entry. In this study, we report an unexpected finding that Myt1 is essential for Golgi and endoplasmic reticulum (ER) assembly during telophase in mammalian cells. Our analyses reveal that both cyclin B1 and cyclin B2 serve as targets of Myt1 for proper Golgi and ER assembly to occur. Thus, our results show that Myt1-mediated suppression of Cdc2 activity is not indispensable for the regulation of a broad range of mitotic events but is specifically required for the control of intracellular membrane dynamics during mitosis.
IL-9– and mast cell–mediated intestinal permeability predisposes to oral antigen hypersensitivity
Authors: Forbes Elizabeth E. , Groschwitz Katherine , Abonia J. Pablo , Brandt Eric B. , Cohen Elizabeth , Blanchard Carine , Ahrens Richard , Seidu Luqman , McKenzie Andrew , Strait Richard , Finkelman Fred D. , Foster Paul S. , Matthaei Klaus I. , Rothenberg Marc E. , Hogan Simon P.
Published: April 2008

Previous mouse and clinical studies demonstrate a link between Th2 intestinal inflammation and induction of the effector phase of food allergy. However, the mechanism by which sensitization and mast cell responses occurs is largely unknown. We demonstrate that interleukin (IL)-9 has an important role in this process. IL-9–deficient mice fail to develop experimental oral antigen–induced intestinal anaphylaxis, and intestinal IL-9 overexpression induces an intestinal anaphylaxis phenotype (intestinal mastocytosis, intestinal permeability, and intravascular leakage). In addition, intestinal IL-9 overexpression predisposes to oral antigen sensitization, which requires mast cells and increased intestinal permeability. These observations demonstrate a central role for IL-9 and mast cells in experimental intestinal permeability in oral antigen sensitization and suggest that IL-9–mediated mast cell responses have an important role in food allergy.
Visualization of unfavorable interactions in protein folds
Authors: Weichenberger Christian X. , Byzia Piotr , Sippl Manfred J.
Published: March 2008

Summary: Three dimensional structures of proteins contain errors which often originate from limitations of the experimental techniques employed. Such errors frequently result in unfavorable atomic interactions. Here we present a new web service, called Interaction Viewer, for the visualization and correction of such errors. We show how the Interaction Viewer is used in combination with the NQ-Flipper service to spot strained asparagine and glutamine rotamers and we emphasize the convenience of this service in correcting such errors.

Availability: The web service is integrated with the NQ-Flipper service and accessible at http://flipper.services.came.sbg.ac.at

Contact:  sippl@came.sbg.ac.at
An improved physico-chemical model of hybridization on high-density oligonucleotide microarrays
Authors: Ono Naoaki , Suzuki Shingo , Furusawa Chikara , Agata Tomoharu , Kashiwagi Akiko , Shimizu Hiroshi , Yomo Tetsuya
Published: April 2008

Motivation: High-density DNA microarrays provide useful tools to analyze gene expression comprehensively. However, it is still difficult to obtain accurate expression levels from the observed microarray data because the signal intensity is affected by complicated factors involving probe–target hybridization, such as non-linear behavior of hybridization, non-specific hybridization, and folding of probe and target oligonucleotides. Various methods for microarray data analysis have been proposed to address this problem. In our previous report, we presented a benchmark analysis of probe–target hybridization using artificially synthesized oligonucleotides as targets, in which the effect of non-specific hybridization was negligible. The results showed that the preceding models explained the behavior of probe–target hybridization only within a narrow range of target concentrations. More accurate models are required for quantitative expression analysis.

Results: The experiments showed that finiteness of both probe and target molecules should be considered to explain the hybridization behavior. In this article, we present an extension of the Langmuir model that reproduces the experimental results consistently. In this model, we introduced the effects of secondary structure formation, and dissociation of the probe–target duplex during washing after hybridization. The results will provide useful methods for the understanding and analysis of microarray experiments.

Availability: The method was implemented for the R software and can be downloaded from our website (http://www-shimizu.ist.osaka-u.ac.jp/shimizu_lab/FHarray/).

Contact:  furusawa@ist.osaka-u.ac.jp

Supplementary information: Supplementary data are available at Bioinformatics online.
Structure–system correlation identifies a gene regulatory Mediator submodule
Authors: Larivière Laurent , Seizl Martin , van Wageningen Sake , Röther Susanne , van de Pasch Loes , Feldmann Heidi , Sträßer Katja , Hahn Steve , Holstege Frank C.P. , Cramer Patrick
Published: April 2008

A combination of crystallography, biochemistry, and gene expression analysis identifies the coactivator subcomplex Med8C/18/20 as a functionally distinct submodule of the Mediator head module. Med8C forms a conserved α-helix that tethers Med18/20 to the Mediator. Deletion of Med8C in vivo results in dissociation of Med18/20 from Mediator and in loss of transcription activity of extracts. Deletion of med8C, med18, or med20 causes similar changes in the yeast transcriptome, establishing Med8C/18/20 as a predominantly positive, gene-specific submodule required for low transcription levels of nonactivated genes, including conjugation genes. The presented structure-based system perturbation is superior to gene deletion analysis of gene regulation.
Protein networks in disease
Authors: Ideker Trey , Sharan Roded
Published: April 2008

During a decade of proof-of-principle analysis in model organisms, protein networks have been used to further the study of molecular evolution, to gain insight into the robustness of cells to perturbation, and for assignment of new protein functions. Following these analyses, and with the recent rise of protein interaction measurements in mammals, protein networks are increasingly serving as tools to unravel the molecular basis of disease. We review promising applications of protein networks to disease in four major areas: identifying new disease genes; the study of their network properties; identifying disease-related subnetworks; and network-based disease classification. Applications in infectious disease, personalized medicine, and pharmacology are also forthcoming as the available protein network information improves in quality and coverage.
Dissection of Rat Brains
Authors: Paul Carol Ann , Beltz Barbara , Berger-Sweeney Joanne
Published: April 2008

INTRODUCTION

In this protocol, the perfused brain of a rat is separated from the surrounding tissue and post-fixed in a formalin/sucrose solution in preparation for freezing and sectioning. Dissection should be done as soon as possible after perfusion to prevent desiccation of the brain. This procedure can also be used to dissect fresh (non-perfused) brains, for example, for Golgi-Cox stain or neurochemical assays.