bluuebunny/crossref_metadata_2025 huggingface dataset:
Exact two-component Hamiltonians revisited
Authors: Liu Wenjian , Peng Daoling
Published: July 2009

Two routes for deriving the exact two-component Hamiltonians are compared. In the first case, as already known, we start directly from the matrix representation of the Dirac operator in a restricted kinetically balanced basis and make a single block diagonalization. In the second case, not considered before, we start instead from the Foldy–Wouthuysen operator and make proper use of resolutions of the identity. The expressions are surprisingly different. It turns out that a mistake was made in the former formulation when going from the Dirac to the Schrödinger picture. The two formulations become equivalent after the mistake is corrected.
The rotational spectrum of the NH+ radical in its X 2Π and a Σ4− states
Authors: Hübers Heinz-Wilhelm , Evenson Kenneth M. , Hill Christian , Brown John M.
Published: July 2009

Transitions between the spin-rotational levels of the N14H+ radical in the v=0 levels of its X 2Π and a Σ4− states have been studied by the technique of laser magnetic resonance at far-infrared wavelengths. The data have been combined with a previous zero-field measurement of the J=112−12 transition frequencies at 1.01 THz to determine a much improved set of molecular parameters for NH+ in the X 2Π state; the major parameters for the a Σ4− state have also been determined. A full determination of the hyperfine parameters for both N14 and H1 nuclei has been achieved for the first time. Accurate predictions of the transition frequencies between the low-lying levels of the radical in the absence of a magnetic field have also been made, including lambda-doubling frequencies for use by radio astronomers.
Theoretical studies of the interactions of ethylene and formaldehyde with gold clusters
Authors: Kang Guo-Jun , Chen Zhao-Xu , Li Zhe
Published: July 2009

We studied the adsorption of C2H4 and CH2O on the gold clusters Aun (n=1–5) in various adsorption modes using density functional theory PW91 functional. We found that the binding energies of π-C2H4 and π and O-σ modes of CH2O increase first and then decrease with the cluster size. Natural bonding orbital (NBO) analyses reveal that the donor-acceptor interaction plays an important role in these adsorption complexes and there is a nice linear relationship between the calculated binding energy and the stabilization energy estimated with second-order perturbation theory in the framework of NBO analysis. It is demonstrated that the bonding interaction between adsorbates and clusters follows the di-σ>π>O-σ mode. However, due to adsorption induced structural deformation of adsorbates and clusters, the binding energies of different adsorption modes are comparable. It is shown that C2H4 interacts more strongly with the clusters than CH2O does and that the previously assigned adsorption mode of C2H4 on Au/MgO may not be the π modes, but the C-σ configuration.
A high-throughput reaction system to measure the gas-phase photocatalytic oxidation activity of TiO2 nanotubes
Authors: Grasser Jordan A. , Muggli Darrin S.
Published: July 2009

A sixteen-channel, high-throughput system was designed and built to test the activity of catalysts for gas-phase photocatalytic oxidation of methanol. The system utilizes granular catalyst films to model relevant applications and allow for rapid processing. It is capable of 48 catalyst tests per day using the procedure described herein. Several experiments were performed to minimize both the within-node and between-node variances of the system. Utilizing the high-throughput system, the significance of preparation methods on the photocatalytic activity of TiO2 nanotubes was investigated. A one-half fractional factorial experiment identified the factors that significantly impact catalyst activity as the following: precursor type (Degussa P-25, or nanotubes), platinum loading, the interaction between precursor and dope time, and the interaction between the precursor and calcination temperature. Based on experimental results, catalyst activity is optimized by doping TiO2 nanotubes directly (rather than doping P-25 prior to nanotube formation), a low platinum loading (0.01 wt %), and using a dope time of 30 min followed by calcination at 773 K. The optimum catalyst preparation conditions produced a catalyst that was three times more active than the starting P-25 material.
Treatment of nonlinear optical properties due to large amplitude anharmonic vibrational motions: Umbrella motion in NH3
Authors: Luis Josep M. , Reis Heribert , Papadopoulos Manthos , Kirtman Bernard
Published: July 2009

A general reduced dimensionality finite field nuclear relaxation method for calculating vibrational nonlinear optical properties of molecules with large contributions due to anharmonic motions is introduced. In an initial application to the umbrella (inversion) motion of NH3 it is found that difficulties associated with a conventional single well treatment are overcome and that the particular definition of the inversion coordinate is not important. Future applications are described.
Double-absorption ferromagnetic resonance in biphase magnetic microwires
Authors: Torrejón J. , Badini-Confalonieri G. A. , Vázquez M.
Published: July 2009

We report a ferromagnetic resonance study of biphase magnetic microwires consisting of soft amorphous nucleus, intermediate nonmagnetic layers, and harder outer crystalline shell. Real and imaginary impedance components are investigated under increasing static axial magnetic field with a network analyzer in the microwave frequency range for selected microwires with different soft nuclei. Natural ferromagnetic resonance is even observed for particular microwires with strong axial anisotropy. The presence of a hard phase induces a second absorption peak at frequencies lower than those of the soft phase. Moreover, magnetic anisotropy of different soft phases is deduced from the evolution of resonance frequency with applied field.
Anomalous Hall effect in quarternary Heusler-type Ni50Mn17Fe8Ga25 melt-spun ribbons
Authors: Zhu Zhiyong , Or Siu Wing , Wu Guangheng
Published: July 2009

The anomalous Hall effect (AHE) in quarternary Heusler-type Ni50Mn17Fe8Ga25 melt-spun ribbons is investigated. Experimental correlation between saturated anomalous Hall resistivity (ρAMS) and longitudinal resistivity (ρxx) is achieved for the low-temperature martensitic phase and the high-temperature austenitic phase as ρAMS∞ρxxn=4.2 and ρAMS∞ρxxn=2.1, respectively. The unexpectedly large exponent of n=4.2 in the martensitic phase is found to contradict the traditional theory of AHE with n=1–2, but it can be explained by a side-jump model beyond the short-range limit as a result of the intermediate-range spin-dependent electron scattering by relatively large Mn-rich clusters instead. The restoration of the exponent back to a normal value of n=2.1 in the austenitic phase is ascribed to the domination of the electron scattering by phonons, compared to that by the Mn-rich clusters, at elevated temperatures and with phonon softening in the transverse-acoustic TA2 mode.
Magnetic coupling properties of rare-earth metals (Gd, Nd) doped ZnO: First-principles calculations
Authors: Shi Hongliang , Zhang Ping , Li Shu-Shen , Xia Jian-Bai
Published: July 2009

The electronic structure and magnetic coupling properties of rare-earth metals (Gd, Nd) doped ZnO have been investigated using first-principles methods. We show that the magnetic coupling between Gd or Nd ions in the nearest neighbor sites is ferromagnetic. The stability of the ferromagnetic coupling between Gd ions can be enhanced by appropriate electron doping into ZnO:Gd system and the room-temperature ferromagnetism can be achieved. However, for ZnO:Nd system, the ferromagnetism between Nd ions can be enhanced by appropriate holes doping into the sample. The room-temperature ferromagnetism can also be achieved in the n-conducting ZnO:Nd sample. Our calculated results are in good agreement with the conclusions of the recent experiments. The effect of native defects (VZn,VO) on the ferromagnetism is also discussed.
The effect of surface roughness scattering on hole mobility in double gate silicon-on-insulator devices
Authors: Donetti Luca , Gámiz Francisco , Rodriguez Noel , Godoy Andres , Sampedro Carlos
Published: July 2009

The effect of surface roughness of the Si/SiO2 interfaces on hole mobility in double gate silicon-on-insulator p-channel devices is studied. Wave functions and dispersion relationships of the hole subbands were computed self-consistently with the potential profile, employing a 6×6 k⋅p model. The roughness of both silicon-oxide interfaces was thoroughly taken into account as a scattering mechanism by extending a model previously developed for n-channel double gate devices and adapting it to the requirements of the k⋅p calculation. Hole mobility was computed using the Kubo–Greenwood formula and the impact of surface roughness was discussed. Volume inversion (mobility increase with regard to conventional bulk channel mobility in a range of silicon layer thicknesses) was observed to have a significant effect, as in n-channel devices.
Energy-gap dependence on the Mn mole fraction and temperature in CdMnTe crystal
Authors: Kim K. H. , Bolotnikov A. E. , Camarda G. S. , Yang G. , Hossain A. , Cui Y. , James R. B. , Hong J. , Kim S. U.
Published: July 2009

We measured the dependence of the energy gap in Bridgman-grown Cd1−xMnxTe crystals, 0≤x≤0.25, on the Mn mole fraction and temperatures from 40 to 300 K. We determined the Mn mole fraction and energy gap, respectively, from electron probe microanalysis and near-infrared Fourier-transform infrared transmission spectra. The energy gap increased linearly with an increase in the Mn content in the crystal and with a decrease in temperature. We formulated new equations from these experimental results, wherein we expressed the energy gap as a function of Mn mole fraction and temperature. Also, we compare our findings with published results.
Charge-transfer character of excitons in poly[2,7-(9,9-di-n-octylfluorene)(1−x)-co-4,7-(2,1,3-benzothiadiazole)(x)]
Authors: Winfield Jessica M. , Van Vooren Antoine , Park Moo-Jin , Hwang Do-Hoon , Cornil Jérôme , Kim Ji-Seon , Friend Richard H.
Published: July 2009

Quantum-chemical calculations performed on poly[2,7-(9,9-di-n-octylfluorene)(1−x)-co-4,7-(2,1,3-benzothiadiazole)(x)] copolymers (0≤x≤0.5) show that the lowest unoccupied molecular orbital is always highly localized on the benzothiadiazole (BT) units while the highest occupied molecular orbital is delocalized over the whole chain. Chains with a low BT content are characterized by a reduced oscillator strength of the lowest optical transition and by an increased charge-transfer character of the exciton. These results are supported experimentally by a blueshift of the lowest energy absorption band upon reduction in the BT ratio, lower photoluminescence efficiency, longer excited state lifetimes, and greater solvent dependence of the emission properties.
Multiferroic behavior observed in highly orientated Mn-doped BaTiO3 thin films
Authors: Lin Yuan-Hua , Yuan Jiancong , Zhang Songyin , Zhang Yi , Liu Jing , Wang Yao , Nan Ce-Wen
Published: July 2009

Highly orientated Mn-doped BaTiO3 thin films have been prepared on Nb-doped SrTiO3 substrate by pulsed laser deposition. Structural and electrical studies indicate that pure and Mn-doped BaTiO3 thin films show single phase character and good ferroelectric performance. All of the Mn-doped BaTiO3 thin films show obvious room-temperature ferromagnetism and the magnetization increases with the growing concentration of doped Mn. A bound magnetic polaron model was proposed to understand the observed ferromagnetic behavior of resistive Mn-doped BaTiO3 thin films. Our results demonstrate that ferromagnetism can be induced in the ferroelectric BaTiO3 film, which makes it a promising single-phase multiferroic.
High sensitivity nuclear magnetic resonance probe for anvil cell pressure experiments
Authors: Haase Jürgen , Goh Swee K. , Meissner Thomas , Alireza Patricia L. , Rybicki Damian
Published: July 2009

While the highest pressures can be achieved with diamond anvil cells, limited sample size and anvil geometry have hampered their application in nuclear magnetic resonance (NMR) experiments due to weak signal-to-noise. Here we report a new probe design that is based on having the resonant radio frequency coil that encloses the sample within the anvil cell inside the gasket hole. This increases the filling factor tremendously and results in greatly enhanced NMR sensitivity. The setup is described together with room temperature Na and Al NMR experiments.
Thermal rectification in asymmetric graphene ribbons
Authors: Yang Nuo , Zhang Gang , Li Baowen
Published: July 2009

In this paper, heat flux in graphene nanoribbons has been studied by using molecular dynamics simulations. It is found that the heat flux runs preferentially along the direction of decreasing width, which demonstrates significant thermal rectification effect in the asymmetric graphene ribbons. The dependence of rectification ratio on the vertex angle and the length are also discussed. Compared to the carbon nanotube based one-dimensional thermal rectifier, graphene nanoribbons have much higher rectification ratio even in large scale. Our results demonstrate that asymmetric graphene ribbon might be a promising structure for practical thermal (phononics) device.
Sn
12
Sb
88
material for phase change memory
Authors: Rao Feng , Song Zhitang , Ren Kun , Li Xuelai , Wu Liangcai , Xi Wei , Liu Bo
Published: July 2009

Phase change memory cell based on Sn12Sb88 film shows reversible phase change abilities between high and low resistance states. We calculate the resonance character of crystalline SnSb material, which proves that SnSb is a potential phase change candidate. Sn12Sb88 is the suitable composition that has faster crystallization speed, higher crystallization temperature, and larger crystallization activation energy but lower melting point than those of Ge2Sb2Te5 material. Hence, phase change memory cell using this composition is able to show quicker set operation speed, better data retention ability, and lower reset power consumption than those of the Ge2Sb2Te5 based cell.
Lattice polarity detection of InN by circular photogalvanic effect
Authors: Zhang Q. , Wang X. Q. , He X. W. , Yin C. M. , Xu F. J. , Shen B. , Chen Y. H. , Wang Z. G. , Ishitani Y. , Yoshikawa A.
Published: July 2009

We report an effective and nondestructive method based on circular photogalvanic effect (CPGE) to detect the lattice polarity of InN. Because of the lattice inversion between In- and N-polar InN, the energy band spin splitting is opposite for InN films with different polarities. Consequently under light irradiation with the same helicity, CPGE photocurrents in In- and N-polar layers will have opposite directions, thus the polarity can be detected. This method is demonstrated by our CPGE measurements in both n- and p-type InN films.
Electromechanical instability in semicrystalline polymers
Authors: Zhao Xuanhe , Suo Zhigang
Published: July 2009

When a layer of a semicrystalline polymer is subject to a tensile force in its plane and a voltage through its thickness, the deformation of the layer is initially homogeneous, but it then localizes. The electromechanical instability sets in when the force and the voltage reach critical conditions. The critical conditions are determined in this paper and are related to the following two special cases: the Considère condition for the necking instability and the Stark–Garton condition for the pull-in instability. The general critical conditions show that a tensile force can markedly reduce the critical voltage.
Effects of highway traffic on diurnal activity of the critically endangered Przewalski's gazelle
Authors: Li Chunwang , Jiang Zhigang , Feng Zuojian , Yang Xiaobo , Yang Ji , Chen Liwei
Published: July 2009

Highway traffic is considered to be one of the factors that influence survival of wildlife. Przewalski’s gazelle is a critically endangered species that lives in the Qinghai Lake watershed of western China. To learn the impacts of traffic on activity patterns of Przewalski’s gazelle, we investigated the relationship between traffic flow and diurnal behaviours of the gazelle on the eastern shore of Qinghai Lake, where a highway was built in 2002. During the summers of 2005 and 2006, we collected traffic data on the highway and observed the activity of the Przewalski’s gazelle population in the area. The results of statistical analysis showed the following: (1) frequency of behaviours such as standing, locomotion, foraging and resting differed among the 15 1-h sampling periods (daytime); (2) numbers of total vehicles, heavy vehicles and light vehicles were significantly different among the daytime hours; (3) there was a positive correlation between the frequency of resting of the gazelles and the number of passing vehicles, and a negative correlation between the frequencies of foraging and alert responses and the number of passing vehicles; (4) by comparing our results with those of a previous study on the gazelles at this site, before the construction of the highway, we found that the diurnal rhythms of foraging, standing and resting have changed markedly (e.g. the three peaks of foraging at 1300, 1600 and 1800 hours in 1996 changed to two peaks of foraging at 0600 and 2000 hours). Our results suggest that the highway traffic may have caused a change in diurnal activity of Przewalski’s gazelle, with the animals tending to keep away from the highway when the traffic flow is high. We suggest traffic-control measures to reduce disturbance to, and thus enhance conservation of, this highly threatened species.
When old and frail is not the same: Dissociating category and stimulus effects in four implicit attitude measurement methods
Authors: Gast Anne , Rothermund Klaus
Published: July 2009

It is not always clear whether implicit attitude measures assess the attitude towards single stimuli or the attitude towards categories. Nevertheless, this is important to know—both for interpreting implicit attitude effects and for selecting the test that is most appropriate for individual research aims. We investigated this for four implicit measures: the standard Implicit Association Test (IAT), the IAT-recoding free (IAT-RF), and two versions of the Extrinsic Affective Simon Task (EAST, identification (ID)-EAST). Effects in the standard IAT reflect evaluations of categories and single stimuli, whereas the IAT-RF measures attitudes towards categories only. Both versions of the EAST measure evaluations of single stimuli independently from the evaluation of categories. Three different effect sources are distinguished: attitudes towards single stimuli (IAT; EAST and ID-EAST), attitudes towards target categories (IAT and IAT-RF), and processes of recoding (IAT), which do not necessarily reflect attitudes.
The CENP-S complex is essential for the stable assembly of outer kinetochore structure
Authors: Amano Miho , Suzuki Aussie , Hori Tetsuya , Backer Chelsea , Okawa Katsuya , Cheeseman Iain M. , Fukagawa Tatsuo
Published: July 2009

The constitutive centromere-associated network (CCAN) proteins are central to kinetochore assembly. To define the molecular architecture of this critical kinetochore network, we sought to determine the full complement of CCAN components and to define their relationships. This work identified a centromere protein S (CENP-S)–containing subcomplex that includes the new constitutive kinetochore protein CENP-X. Both CENP-S– and CENP-X–deficient chicken DT40 cells are viable but show abnormal mitotic behavior based on live cell analysis. Human HeLa cells depleted for CENP-X also showed mitotic errors. The kinetochore localization of CENP-S and -X is abolished in CENP-T– or CENP-K–deficient cells, but reciprocal experiments using CENP-S–deficient cells did not reveal defects in the localization of CCAN components. However, CENP-S– and CENP-X–deficient cells show a significant reduction in the size of the kinetochore outer plate. In addition, we found that intrakinetochore distance was increased in CENP-S– and CENP-X–deficient cells. These results suggest that the CENP-S complex is essential for the stable assembly of the outer kinetochore.
Development of a drug–disease simulation model for rituximab in follicular non‐Hodgkin's lymphoma
Authors: Ternant David , Hénin Emilie , Cartron Guillaume , Tod Michel , Paintaud Gilles , Girard Pascal
Published: July 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Serum concentrations of rituximab influence its clinical efficacy in follicular lymphoma (FL), but its concentration–effect relationship has not been described by pharmacokinetic–pharmacodynamic (PK–PD) modelling.

• The genetic polymorphism of FCGR3A influences rituximab efficacy and its in vitro concentration–effect relationship.

• Increasing rituximab dose and/or number of infusions may lead to a better clinical response in FL.

WHAT THIS PAPER ADDS

• This study is the first to describe the concentration–effect relationship of rituximab in populations of FL patients.

• This PK–PD model relates progression‐free survival with rituximab concentrations and takes into account the influence of FCGR3A polymorphism.

• Clinical trials testing new dosing regimens of rituximab can be designed using this PK–PD model.

AIM

Rituximab has dramatically improved the survival of patients with non‐Hodgkin's lymphomas (NHL), but the dosing regimen currently used should be optimized. However, the concentration–effect relationship of rituximab has never been described by pharmacokinetic–pharmacodynamic (PK–PD) modelling, precluding the simulation of new dosing regimens. The aim of this study was to develop a PK–PD model of rituximab in relapsed/resistant follicular NHL (FL).

METHODS

A model describing the relationship between rituximab concentrations and progression‐free survival (PFS) was developed using data extracted from the pivotal study, which evaluated 151 relapsed/resistant FL patients. The influence of FCGR3A genetic polymorphism on the efficacy of rituximab was quantified using data from 87 relapsed/resistant FL patients. The predictive performance of the model was analysed using two independent datasets: a study that evaluated rituximab combined with chemotherapy [rituximab, cyclophosphamide, vincristine, adriamycin and prednisone (R‐CHOP)] in 334 relapsed/resistant FL patients and a study that evaluated rituximab monotherapy in 47 asymptomatic FL patients with known FCGR3A genotype.

RESULTS

For R‐CHOP, observed and model‐predicted PFS (90% confidence interval) at 24 months were 0.50 and 0.48 (0.40, 0.56), respectively, for the observation arm, and 0.62 and 0.59 (0.50, 0.65), respectively, for the rituximab maintenance arm. For rituximab monotherapy, observed and predicted PFS at 24 months were 0.67 and 0.63, respectively, for FCGR3A‐V/V patients, and 0.41 and 0.36 (0.25, 0.49), respectively, for FCGR3A‐F carriers.

CONCLUSIONS

Our model provides a satisfactory prediction of PFS at 24 months. It can be used to simulate new dosing regimens of rituximab in populations of FL patients and should improve the design of future clinical trials.
Sudden death in patients receiving drugs tending to prolong the QT interval
Authors: Jolly Kate , Gammage Michael D. , Cheng Kar Keung , Bradburn Peter , Banting Miriam V. , Langman Michael J. S.
Published: July 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Drugs slowing electocardiographic QT conduction can cause tachyarrhythmias, torsades de pointes (TdP) and cardiac arrest.

• Associated risks of sudden death have been consistently found for older, typical, antipsychotic drugs, but epidemiological evidence of risks for other drugs are poorly defined.

WHAT THIS STUDY ADDS

• In a population‐based study risk of sudden death with noncardiac drug treatment was mainly posed by antipsychotics both typical and atypical, and by antidepressants, particularly selective serotonin reuptake inhibitors.

• Results could not be accounted for by confounding.

• No significant risk was associated with use of other noncardiac or psychiatric drugs.

• A published general categorization of risk of drug‐induced TdP corresponded poorly with these findings.

AIMS

To examine risks of sudden death in the community associated with drugs grouped by their risk of causing torsades de pointes (TdP) and to explore the risks for individual drugs.

METHODS

Case–control study comparing prior drug intakes and morbidities, using the Arizona classification of drugs causing TdP. Participants included 1010 patients dying suddenly where post‐mortem examination did not identify a clear cause of death, and 3030 matched living controls from primary care.

RESULTS

Noncardiac drug risk was posed by antipsychotics and antidepressants. Significantly raised odds ratios (ORs) were found for takers of typical and atypical antipsychotics, ORs [95% confidence interval] 3.94 (2.05, 7.55) and 4.36 (2.54, 7.51), and of selective serotonin reuptake inhibitors [SSRIs] rather than tricyclic antidepressants, ORs 2.21 (1.61, 3.05) and 1.44 (0.96, 2.13). No significant risk was associated with other, noncardiac or psychiatric drugs, OR 1.09 (0.85, 1.41). Arizona classified drugs considered to raise risk of TdP were associated with raised risk of sudden death, as were those only weakly associated with TdP and not considered to pose a risk in normal use, ORs 2.08 (1.45, 3.00) and 1.74 (1.33, 2.28), respectively.

CONCLUSIONS

Atypical and typical antipsychotic drug use were both strongly associated with raised risks, as were SSRIs. Tricyclic antidepressants were not associated with raised risks. The Arizona classification of risk of TdP was a poor predictor of likelihood of noncardiac drug‐associated sudden death.
Effects of an experimental drought on the functioning of a cacao agroforestry system, Sulawesi, Indonesia
Authors: SCHWENDENMANN LUITGARD , VELDKAMP EDZO , MOSER GERALD , HÖLSCHER DIRK , KÖHLER MICHAEL , CLOUGH YANN , ANAS ISWANDI , DJAJAKIRANA GUNAWAN , ERASMI STEFAN , HERTEL DIETRICH , LEITNER DANIELA , LEUSCHNER CHRISTOPH , MICHALZIK BEATE , PROPASTIN PAVEL , TJOA AIYEN , TSCHARNTKE TEJA , Van STRAATEN OLIVER
Published: July 2009

Agroforestry systems may play a critical role in reducing the vulnerability of farmers' livelihood to droughts as tree‐based systems provide several mechanisms that can mitigate the impacts from extreme weather events. Here, we use a replicated throughfall reduction experiment to study the drought response of a cacao/Gliricidia stand over a 13‐month period. Soil water content was successfully reduced down to a soil depth of at least 2.5 m. Contrary to our expectations we measured only relatively small nonsignificant changes in cacao (−11%) and Gliricidia (−12%) sap flux densities, cacao leaf litterfall (+8%), Gliricidia leaf litterfall (−2%), soil carbon dioxide efflux (−14%), and cacao yield (−10%) during roof closure. However, cacao bean yield in roof plots was substantially lower (−45%) compared with control plots during the main harvest following the period when soil water content was lowest. This indicates that cacao bean yield was more sensitive to drought than other ecosystem functions. We found evidence in this agroforest that there is complementary use of soil water resources through vertical partitioning of water uptake between cacao and Gliricidia. This, in combination with acclimation may have helped cacao trees to cope with the induced drought. Cacao agroforests may thus play an important role as a drought‐tolerant land use in those (sub‐) tropical regions where the frequency and severity of droughts is projected to increase.
Host–parasite interactions and vectors in the barn swallow in relation to climate change
Authors: MØLLER A. P.
Published: July 2009

Recent climate change has affected the phenology of numerous species, and such differential changes may affect host–parasite interactions. Using information on vectors (louseflies, mosquitoes, blackflies) and parasites (tropical fowl miteOrnithonyssus bursa, the louseflyOrnithomyia avicularia, a chewing louseBrueeliasp., two species of feather mitesTrouessartia cruciferaandTrouessartia appendiculata, and two species of blood parasitesLeucozytozoon whitworthiandHaemoproteus prognei) of the barn swallowHirundo rusticacollected during 1971–2008, I analyzed temporal changes in emergence and abundance, relationships with climatic conditions, and changes in the fitness impact of parasites on their hosts. Temperature and rainfall during the summer breeding season of the host increased during the study. The intensity of infestation by mites decreased, but increased for the lousefly during 1982–2008. The prevalence of two species of blood parasites increased during 1988–2008. The timing of first mass emergence of mosquitoes and blackflies advanced. These temporal changes in phenology and abundance of parasites and vectors could be linked to changes in temperature, but less so to changes in precipitation. Parasites had fitness consequences for hosts because intensity of the mite and the chewing louse was significantly associated with delayed breeding of the host, while a greater abundance of feather mites was associated with earlier breeding. Reproductive success of the host decreased with increasing abundance of the chewing louse. The temporal decrease in mite abundance was associated with advanced breeding of the host, while the increase in abundance of the lousefly was associated with earlier breeding. Virulence by the tropical fowl mite decreased with increasing temperature, independent of confounding factors. These findings suggest that climate change affects parasite species differently, hence altering the composition of the parasite community, and that climate change causes changes in the virulence of parasites. Because the changing phenology of different species of parasites had both positive and negative effects on their hosts, and because the abundance of some parasites increased, while that of other decreased, there was no consistent temporal change in host fitness during 1971–2008.
Neuropeptide W has Cell Phenotype‐Specific Effects on the Excitability of Different Subpopulations of Paraventricular Nucleus Neurones
Authors: Price C. J. , Samson W. K. , Ferguson A. V.
Published: July 2009

The administration of the neuropeptide W (NPW) and neuropeptide B (NPB) in rodents has been shown to influence the activity of a variety of autonomic and neuroendocrine systems. The paraventricular nucleus (PVN) is a major autonomic and neuroendocrine integration site in the hypothalamus, and neurones within this nucleus express the receptor for these ligands, NPB/W receptor 1 (NPBWR1). In the present study, we used whole cell patch clamp recordings coupled with single‐cell reverse transcriptase‐polymerase chain reaction to examine the effects of neuropeptide W‐23 (NPW‐23) on the excitability of identified PVN neurones. Oxytocin, vasopressin and thyrotrophin‐releasing hormone neurones were all found to be responsive to 10 nm NPW‐23, although both depolarising and hyperpolarising effects were observed in each of these cell groups. By contrast, corticotrophin‐releasing hormone cells were unaffected. Further subdivision of chemically phenotyped cell groups into magnocellular, neuroendocrine or pre‐autonomic neurones, using their electrophysiological fingerprints, revealed that neurones projecting to medullary and spinal targets were predominantly inhibited by NPW‐23, whereas those that projected to median eminence or neural lobe showed almost equivalent numbers of depolarising and hyperpolarising cells. The demonstration of particular phenotypic populations of PVN neurones showing NPW‐induced effects on excitability reinforces the importance of the NPB/NPW neuropeptide system as a regulator of autonomic function.
At work or play: A comparison of private property vehicle crashes with those occurring on public roads in north Queensland
Authors: Blackman Ross , Cheffins Tracy , Veitch Craig , O'Connor Teresa
Published: July 2009

Objective:  To define characteristics of vehicle crashes occurring on rural private property in north Queensland with an exploration of associated risk factors.

Design:  Descriptive analysis of private property crash data collected by the Rural and Remote Road Safety Study.

Setting:  Rural and remote north Queensland.

Participants:  A total of 305 vehicle controllers aged 16 years or over hospitalised at Atherton, Cairns, Mount Isa or Townsville for at least 24 hours as a result of a vehicle crash.

Main outcome measure:  A structured questionnaire completed by participants covering crash details, lifestyle and demographic characteristics, driving history, medical history, alcohol and drug use and attitudes to road use.

Results:  Overall, 27.9% of interviewees crashed on private property, with the highest proportion of private road crashes occurring in the North West Statistical Division (45%). Risk factors shown to be associated with private property crashes included male sex, riding off‐road motorcycle or all‐terrain vehicle, first‐time driving at that site, lack of licence for vehicle type, recreational use and not wearing a helmet or seatbelt.

Conclusions:  Considerable trauma results from vehicle crashes on rural private property. These crashes are not included in most crash data sets, which are limited to public road crashes. Legislation and regulations applicable to private property vehicle use are largely focused on workplace health and safety, yet work‐related crashes represent a minority of private property crashes in north Queensland.
Otitis media in Aboriginal children: The discordance between burden of illness and access to services in rural/remote and urban Australia
Authors: Gunasekera Hasantha , Morris Peter S , Daniels John , Couzos Sophie , Craig Jonathan C
Published: July 2009

Objective:  To compare the burden of otitis media (OM) managed by Aboriginal Medical Service (AMS) practitioners and the availability of specialist ear health services in rural/remote versus urban Australian settings.

Design, Setting and Participants:  We mailed questionnaires to all Australian AMS medical practitioners managing children in December 2006. Questions addressed the frequency of childhood OM cases seen, and the availability and waiting times for audiology; ear, nose and throat (ENT); and hearing‐aid services. We compared rural/remote and urban practitioner's responses using the χ2 test with clustering adjustments.

Results:  Questionnaires were returned by 63/87 (72%) AMSs and by 131/238 (55%) eligible practitioners. Rural/Remote practitioners reported managing a greater number of children with OM per week than urban practitioners (1 df, P= 0.02) and a larger proportion of the children they managed having OM (1 df, P= 0.009). More rural/remote than urban practitioners reported relevant services were not available locally: audiology (11.1 vs. 0%, P= 0.038), ENT (33.3 vs. 3.9%, P= 0.0004) and hearing‐aid provision (37.7 vs. 1.9%, P < 0.0001). More rural/remote practitioners reported audiology waiting times longer than the recommended 3 months (18.3 vs. 1.9%, P= 0.007). Equal proportions reported ENT waiting times longer than the recommended 6 months (13.9 vs. 11.3%, P= 0.7).

Conclusions:  Rural/Remote AMS practitioners manage a greater OM burden than urban AMS practitioners, but affected children have less access to specialist ear health services and longer waiting times. One in five rural/remote Aboriginal children wait longer than recommended for audiology testing, and one in eight Aboriginal children nationwide wait longer than recommended for ENT services.
Assessment of the burden of paediatric empyema in Australia
Authors: Strachan Roxanne , Jaffé Adam
Published: July 2009

Aims:  To investigate the change in incidence of childhood empyema and pneumonia in Australia, and ascertain the management trends in all hospitals caring for children with empyema.

Methods:  The incidences of empyema and pneumonia were calculated for each year between 1993/1994 and 2004/2005 using retrospective primary diagnostic coding from ICD‐9 and 10 comprising the Australian National Hospital Morbidity Database for five age groups in patients less than 20 years of age. Hospitals with allocated paediatric beds were surveyed on referral pattern and treatment preferences.

Results:  In this study, 145 562 patients with pneumonia were admitted with a mean (range) incidence of 2306 (1846–2652) per million. The trend towards an overall increase was not statistically significant. Only the 1–4 years old age group demonstrated a significant increase (P < 0.01, r2= 0.61). A total of 469 cases of empyema were identified with a mean incidence of 7.35 (4–10.2) per million. There was an overall increase in incidence (P < 0.05, r2= 0.51) reflecting an increase in the 1‐ to 4‐year‐olds (P < 0.005, r2= 0.60) and 15‐ to 19‐year‐olds (P < 0.05, r2= 0.37). The overall percentage of empyema as a proportion of pneumonia increased from 0.27 to 0.70% (0.48% (0.27–0.70%), P < 0.05, r2= 0.38). The survey response rate was 75%. Ninety‐nine of 121 (82%) hospitals referred children with empyema to a more appropriate centre with wide variations in treatments provided.

Conclusions:  The rise in incidence of empyema reflects that seen in other countries. Furthermore, there are diverse management practices suggesting a clear need for national guidelines.
Emergency management of paediatric status epilepticus in Australia and New Zealand: Practice patterns in the context of clinical practice guidelines
Authors: Babl Franz E , Sheriff Nisa , Borland Meredith , Acworth Jason , Neutze Jocelyn , Krieser David , Ngo Peter , Schutz Jacquie , Thomson Fiona , Cotterell Elizabeth , Jamison Sarah , Francis Peter
Published: July 2009

Aims:  To establish current acute seizure management through a review of clinical practice guidelines (CPGs) and reported physician management in the 11 largest paediatric emergency departments in Australia (n= 9) and New Zealand (n= 2) within the Paediatric Research in Emergency Departments International Collaborative (PREDICT) network, and to compare this with Advanced Paediatric Life Support (APLS) guidelines and existing evidence.

Methods:  (i) Review of CPGs for acute seizure management at PREDICT sites. (ii) A standardised anonymous survey of senior emergency doctors at PREDICT sites investigating management of status epilepticus (SE).

Results:  Ten sites used seven different seizure CPGs. One site had no seizure CPG. First line management was with benzodiazepines (10 sites). Second line and subsequent management included phenytoin (10), phenobarbitone (10), thiopentone (9), paraldehyde (6) and midazolam infusion (5). Of 83 available consultants, 78 (94%) responded. First line management of SE without intravenous (IV) access included diazepam per rectum (PR) (49%), and midazolam intramuscular (41%) and via the buccal route (9%). First line management of SE with IV access included midazolam IV (50%) and diazepam IV (44%). The second line agent was phenytoin (88%); third line agents were phenobarbitone (33%), thiopentone and intubation (32%), paraldehyde PR (22%) and midazolam infusion (6%). Fourth line agents were thiopentone and intubation (60%), phenobarbitone (16%), midazolam infusion (13%) and paraldehyde (9%).

Conclusions:  Initial seizure management by CPG recommendations and reported physician practice was broadly similar across PREDICT sites and consistent with APLS guidelines. Practice was variable for second/third line SE management. Areas of controversy would benefit from multi‐centred trials.
The web‐building spider Theridion impressum (Araneae: Theridiidae) is not adversely affected by Bt maize resistant to corn rootworms
Authors: Meissle Michael , Romeis Jörg
Published: July 2009

The growth of genetically engineered maize that produces the insecticidal protein Cry3Bb1 from Bacillus thuringiensis (Bt) is an effective method to control corn rootworms (Diabrotica spp.), which are threatening maize production in North America and Europe. In this study, the risk of Cry3Bb1‐expressing maize for the predatory spider Theridion impressum, a common species in European maize fields, was assessed. Quantification of Cry3Bb1 in potential prey species collected in Bt maize plots and prey spectrum analysis revealed that T. impressum ingests Cry3Bb1 in the field. Exposure to the Bt protein, however, was highly variable because some potential prey species, such as phloem‐feeding herbivores and predators, contained little or no Cry3Bb1, whereas leaf‐feeding herbivores contained high concentrations. Adult and juvenile T. impressum spiders were fed with Cry3Bb1‐containing food (prey or maize pollen) for 8 weeks in the laboratory to examine the toxicity of the Bt protein. No differences in mortality, weight development or offspring production were observed between spiders provided with food containing or not containing Cry3Bb1. Retrospective power analysis indicated that the bioassays were sufficiently sensitive to detect meaningful differences if present. Although Cry3Bb1 is ingested by the spider in the field, our data provide no evidence for toxicity. Consequently, the growth of corn rootworm‐resistant Bt maize appears to pose no risk for T. impressum.
Ancient DNA perspective on the failed introduction of mongooses in Italy during the XXth century
Authors: Gaubert P. , Zenatello M.
Published: July 2009

We used ancient DNA techniques to amplify mitochondrial DNA fragments [cytochrome b (cyt b) and control region (CR)] from four museum specimens that represent, to our knowledge, the last testimony of the introduction of – now extinct – mongooses in Italy. We assessed the identity, origin and genetic variability of Italian mongooses using a species‐level assignation Bayesian approach and haplotype network analysis. The genetic diversity (cyt b and CR) among Italian individuals was null. The cyt b sequences from the four museum specimens clearly established the Indian grey mongoose Herpestes edwardsii as the species having been introduced in Italy in the mid‐XXth century. The latter had at least been released twice within a period of 10 years (Circeo NP and Capalbio, c. 200 km northward), probably from the same captive stock of the Giardino Zoologico di Roma. Assessment of genetic variability and haplotype network including native representatives of H. edwardsii suggested that the introduced pool likely originated from Pakistan or India. It appears that a combination of deleterious factors including low genetic diversity, restricted range and nonadaptation to western Palaearctic winter conditions is responsible for the extinction of the species in Italy. However, the lack of knowledge on the life‐history traits and population dynamics of H. edwardsii prevents from further discussion of the factors that likely promoted its extinction process.
Bridging East and West: Muslim‐identified activists and organisations in the UK anti‐war movements
Authors: Phillips Richard
Published: July 2009

Divisive Orientalist discourses and practices, mobilised in the ‘war on terror’, have been resisted through collaborative political projects designed to contest and close gaps between East and West, Muslim and non‐Muslim. Through interviews with Muslim‐identified and other British anti‐war activists, this paper traces the making of a ‘new bridge between the East and the West’. It then goes on to examine the limitations of this political model and describe the search for political relationships that would mobilise Muslim identities in more subtle ways and speak past rather than against contemporary Orientalism.
Estimating the Quantity and Economic Value of Family Caregiving for Community‐Dwelling Older Persons in the Last Year of Life
Authors: Rhee YongJoo , Degenholtz Howard B. , Lo Sasso Anthony T. , Emanuel Linda L.
Published: July 2009

OBJECTIVES: To estimate the quantity and economic value of informal care provided to older persons during their final year of life in the community.

DESIGN: Retrospective analysis of publicly available nationally representative survey data.

SETTING: This retrospective study used data from the Health and Retirement Study, a nationally representative, longitudinal study of community‐dwelling older people.

PARTICIPANTS: Older people who died between 2000 and 2002.

MEASUREMENTS: Data were extracted from the 2002 “exit survey” and linked with characteristics of caregivers from the helper file. Ordinary least squares regression was used to estimate hours of informal caregiving for community‐dwelling older people (N=990). Adjusted hours were multiplied by the 2002 national average home aide wage ($9.16 per hour). Sensitivity tests were performed using the 10th percentile wage rate ($6.56) and 90th percentile wage rate ($12.34).

RESULTS: Older people who died in the community received on average 65.8 hours per week of informal care in the last year of life. The estimated economic value ranges from $22,514 to $42,351, which is equivalent to the annual direct replacement cost with a home aide in 2002.

CONCLUSION: Family members provide substantial assistance during the last year of life for older people who die in the community. If the informal care provided in the last year of life is replaced with a home aide, the total economic value for the United States would be approximately $1.4 billion (in 2002).
Positron Lifetime Study of the Crystal Evolution and Defect Formation Processes in a Scintillating Glass
Authors: Nie Jiaxiang , Yu Runsheng , Wang Baoyi , Ou Yuwen , Zhong Yurong , Li Zhuoxin , Xia Fang , Chen Guorong
Published: July 2009

The crystal evolution and defect formation in scintillating glasses as a consequence of thermal annealing were studied by annihilation lifetime spectroscopy and UV‐Vis absorption spectroscopy. The annihilation lifetime spectra and UV‐Vis spectra were recorded on glass 50SiO2–45ZnO–5BaF2 before and after annealing at 580°C for 16, 32, and 48 h, respectively. The results show that the three lifetime components (τ1, τ2, and τ3) and the corresponding intensities (I1, I2, and I3) change systematically with increasing annealing time. This reflects the crystal evolution and defect formation in the glass matrix. The continued crystal evolution was also revealed by the UV‐Vis spectra, as the absorption edge of the material shifted to a lower energy with prolonged annealing.
Structure and Microwave Dielectric Characteristics of Ca1+xNd1−xAl1−xTixO4 Ceramics
Authors: Yuan Hong Xia , Chen Xiang Ming , Mao Min Min
Published: July 2009

CaNdAlO4 microwave dielectric ceramics were modified by Ca/Ti co‐substitution, and their dielectric characteristics were evaluated along with their structure and microstructures. Ca1+xNd1−xAl1−xTixO4 (x=0, 0.025, 0.05, 0.10, 0.15, 0.20) ceramics with the relative density of over 95% theoretical density were obtained by sintering at 1400°–1450°C in air for 3 h, where the K2NiF4‐type solid solution single phase was determined from the compositions of x<0.20, while a small amount of CaTiO3 secondary phase was detected for x=0.20. With Ca/Ti co‐substitution in CaNdAlO4 ceramics, the dielectric constant (ɛr) increased with increasing x, and the temperature coefficient of resonant frequency (τf) was adjusted from negative to positive, while the Q×f0 value increased significantly at first and reached an extreme value at x=0.025 and the maximum at x=0.15. The best combination of microwave dielectric characteristics were achieved at x=0.15 (ɛr=19.5, Q×f0=93 400 GHz, τf=−2 ppm/°C). The improvement of the Q×f0 value primarily originated from the reduced interlayer polarization with Ca/Ti co‐substitution, while the decreased tolerance factor, the subsequent increased interlayer stress, and the appearance of CaTiO3 secondary phase brought negative effects upon the Q×f0 value.