bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron energy boosting in laser-wake-field acceleration with external magnetic field B∼1 T and laser prepulses
Authors: Hosokai Tomonao , Zhidkov Alexei , Yamazaki Atsushi , Mizuta Yoshio , Uesaka Mitsuru , Kodama Ryosuke
Published: March 2010

Hundred-mega-electron-volt electron beams with quasi-monoenergetic distribution, and a transverse geometrical emittance as small as ∼0.02 π mm mrad are generated by low power (7 TW, 45 fs) laser pulses tightly focused in helium gas jets in an external static magnetic field, B∼1 T. Generation of monoenergetic beams strongly correlates with appearance of a straight, at least 2 mm length plasma channel in a short time before the main laser pulse and with the energy of copropagating picosecond pedestal pulses (PPP). For a moderate energy PPP, the multiple or staged electron self-injection in the channel gives several narrow peaks in the electron energy distribution.
The role of stoichiometry of indium and oxygen on gas sensing properties of indium oxide nanostructures
Authors: Kumar Mukesh , Mehta B. R. , Singh V. N. , Chatterjee R. , Milikisiyants S. , Lakshmi K. V. , Singh J. P.
Published: March 2010

We report direct evidence of the role of stoichiometry of one-dimensional indium oxide (IO) nanostructures grown by vapor-phase evaporation method on the ethanol gas sensing properties. The stoichiometric crystalline In2O3 nanowires grown under oxidizing (water) ambient exhibit about two orders of magnitude higher sensor response value of 281 in comparison to nonstoichiometric (In/O ∼0.75) nanotubes grown under reducing (ethanol) ambient in presence of 1000 ppm ethanol gas at 300 °C. We propose that for a stoichiometric IO nanowire, Debye region completely depletes the nanowire from free charge carriers which results in a significant increase in the sensor response.
Enhanced electron capture and symmetrized carrier distribution in GaInN light-emitting diodes having tailored barrier doping
Authors: Zhu Di , Noemaun Ahmed N. , Schubert Martin F. , Cho Jaehee , Schubert E. Fred , Crawford Mary H. , Koleske Daniel D.
Published: March 2010

The confinement of electrons to the active region of GaInN light-emitting diodes (LEDs) is limited by the (i) inefficient electron capture into polar quantum wells, (ii) electron-attracting properties of electron-blocking layers (EBL), (iii) asymmetry in electron and hole transport, and (iv) unfavorable p-doping in the EBL for high Al content. To counteract these mechanisms, we employ tailored Si-doping in the quantum barriers (QBs). Experiments show a 37.5% enhancement in light-output power at high currents of one-QB-doped LEDs over all-QB-doped LEDs. These results are consistent with simulations showing that QB doping can be used to symmetrize the electron and hole distribution.
Dependence of persistent photocurrent on gate bias in inkjet printed organic thin-film transistor
Authors: Kim Chang Hyun , Choi Min Hee , Lee Sun Hee , Jang Jin , Kirchmeyer Stephan
Published: March 2010

We have studied the photocurrent decay under gate bias in organic thin-film transistor (OTFT) using inkjet printed α,ω-dihexylquarterthiophene layer. The OTFT shows high photocurrents under light illumination and very slow decay of photocurrents under positive gate voltage. This is due to the gate voltage-controlled trapping and detrapping of the electrons near the interface. With increasing exposure time, more electrons are trapped and thus make the photocurrent decay slower. It is found that there is a power-law dependence between light exposure time and decay time constant.
Coaxial atomic force microscope tweezers
Authors: Brown K. A. , Aguilar J. A. , Westervelt R. M.
Published: March 2010

We demonstrate coaxial atomic force microscope (AFM) tweezers that can trap and place small objects using dielectrophoresis (DEP). An attractive force is generated at the tip of a coaxial AFM probe by applying a radio frequency voltage between the center conductor and a grounded shield; the origin of the force is found to be DEP by measuring the pull-off force versus applied voltage. We show that the coaxial AFM tweezers can perform three-dimensional assembly by picking up a specified silica microsphere, imaging with the microsphere at the end of the tip, and placing it at a target destination.
Large-area InP-based crystalline nanomembrane flexible photodetectors
Authors: Yang Weiquan , Yang Hongjun , Qin Guoxuan , Ma Zhenqiang , Berggren Jesper , Hammar Mattias , Soref Richard , Zhou Weidong
Published: March 2010

Large-area (3×3 mm2) flexible photodetectors were realized, based on crystalline InP semiconductor nanomembranes transferred to flexible polyethylene terephthalate substrates. Very low dark current (a few microamperes) and high responsivity (0.12 A/W) were demonstrated for flexible InP p-i-n photodetectors. Bending characteristics were also investigated for this type of flexible crystalline semiconductor photodetector, and it was found that, whereas the dark current was independent of bending radii, the photocurrent degraded, depending on the bending radii.
Crystal structure and optical study of Tm:Sc2SiO5 single crystal
Authors: Zheng Lihe , Xu Jun , Su Liangbi , Li Hongjun , Ryba-Romanowski Witold , Lisiecki Radosław , Solarz Piotr
Published: March 2010

Sc 2 SiO 5 : 4   at .   % Tm crystal was obtained by the Czochralski method and the crystal cell parameters were calculated. Sixfold coordinated Sc-ions occupied two different crystallographic sites but the low temperature optical spectra only represented energy transitions originating from Tm ions residing in one site. Room temperature absorption spectrum was analyzed in the framework of Judd–Ofelt theory and the calculated absorption coefficient and cross section were 10.47 cm−1 and 5.55×10−21 cm2 at 791 nm respectively. Stimulated emission cross sections for the F34–H36 transition near 1900 nm were evaluated using the reciprocity method while the luminescence F34 lifetime was measured to be 1.14 ms. We conclude that Tm:Sc2SiO5 is promising for diode-pumped infrared lasers.
Backside-illuminated infrared photoluminescence and photoreflectance: Probe of vertical nonuniformity of HgCdTe on GaAs
Authors: Shao Jun , Chen Lu , Lu Wei , Lü Xiang , Zhu Liangqing , Guo Shaoling , He Li , Chu Junhao
Published: March 2010

Vertical uniformity of HgCdTe epilayer is a crucial parameter for infrared detector engineering. In this work, backside illuminated infrared photoluminescence (PL) and photoreflectance (PR) measurements are carried out on an arsenic-doped Hg1−xCdxTe layer molecular-beam epitaxially grown on GaAs substrate, and the alloy composition and impurity states of the HgCdTe near the substrate are evaluated. By comparing to frontside illuminated PL and PR data, the vertical nonuniformity of composition and impurity states are evidenced. The results indicate that backside illuminated PL and PR are good pathway for evaluating contactlessly the nonuniformity of alloy composition and impurity states along the growth direction.
Ecological Concepts and Strategies with Relevance to Energy-Conscious Spatial Planning and Design
Authors: Stremke Sven , Koh Jusuck
Published: March 2010

Sustainable systems utilise renewable energy sources and recycle materials effectively. In theory, solar radiation provides abundant energy to sustain humanity. Our capacity to utilise available sources, however, is limited and competition for resources is expected to increase in the future. Spatial organisation and design of the physical environment influences two aspects of sustainable energy transition: assimilation of renewables and energy consumption. How can spatial planning and design support the transition from fossil fuels to a sustainable energy regime? Natural ecosystems constitute one source of inspiration. They are described with the help of ecological concepts; some of which reveal how energy flow is optimised in nature. Ecological concepts and ecosystem strategies are not limited to the description of natural phenomena; they can also inform energy-conscious planning and design of neighborhoods, cities, and entire regions. We identify and discuss nine ecological concepts with relevance to energy-conscious spatial planning and design.
Competencies required by senior health executives in New South Wales, 1990 - 1999
Authors: Liang Zhanming , Howard Peter F.
Published: March 2010

It is accepted that health care reforms and restructuring lead to the change of the tasks and competencies required by senior health care managers. This paper examined the major tasks that senior health executives performed and the most essential competencies required in the NSW public health sector in the 1990s following the introduction of major structural reforms. Diverse changes, restructuring and reforms introduced and implemented in different health care sectors led to changes in the tasks performed by health care managers, and consequently changes in the competencies required. What is known about the topic?The literature confirms that health reform affects senior health care managers’ acquisition and demonstration of new skills and knowledge to meet new job demands. What does this paper add?This paper provides a detailed description of the competencies required for senior health care managers in New South Wales in the 1990s after the introduction of the area health management model, the senior executive service and performance agreements. It confirms that restructuring and reform in the health care sector will lead to changes of the tasks performed by health care managers and, consequently, changes in the competencies required. What are the implications for practitioners?The competencies required by health care managers are affected by distinct management levels, diverse health care sectors and different contexts in which health care systems operate. The competencies identified for senior health executives in this study could guide educational programs for senior health managers in the future.
The role of health professionals in health promotion: a case study of medical imaging technologists and alcohol
Authors: Boldy Duncan P. , Yates Caroline , Ong Teresa A.
Published: March 2010

This study aimed to determine the knowledge, attitudes and behaviour of medical imaging technologists (MITs) in Western Australia regarding alcohol. The WA population of 220 MIT members of the Australian Institute of Radiography was surveyed by mail in 2004. Specific questions were devised and piloted covering knowledge of alcohol, alcoholic content and drink size, and related personal behaviour. Responses were obtained from 91 MITs. Overall, they had a good knowledge of key facts related to alcohol. However, this did not always translate into appropriate attitudes and behaviour related to dealing with alcohol abuse. While statistically significant differences were not found according to sex, age group or location (metropolitan or rural), some trends were apparent. This study has found that MITs are not currently as equipped as they should be to be part of the health promotion model of education. What is known about the topic?Health professionals regularly see the results of accidents, injuries and disease from the abuse of alcohol, yet their role in relation to health promotion is under-researched. Little is known about the knowledge, attitudes and behaviour of medical imaging technologists in relation to alcohol and its abuse, and hence their preparedness to play a health promotion role. What does this paper add?While the respondents had good knowledge about alcohol this did not translate into appropriate behaviours. What are the implications for practitioners?Information is provided to guide a more vigorous approach towards educating health professionals about alcohol abuse for a more active role in health promotion.
Experiences of nursing in older care facilities in New Zealand
Authors: Carryer Jenny , Hansen Chiquita O. , Blakey Judy A.
Published: March 2010

To examine issues related to the working life of registered nurses in residential care for older people in New Zealand, 48 registered nurses completed surveys (n = 28) or participated in discussions (n = 26) regarding their work roles, continuing education and interactions with specialist nurse services when providing care for older people living with chronic illnesses. This nursing workforce is characterised by ageing, relative isolation, reduced confidence and few opportunities for induction of new graduates. Registered nurses reported their struggle to deliver the appropriate quality of care to residents as acuity increases, general practitioner availability decreases and the opportunities for increasing their knowledge and competence remain limited. The provision of nursing services in residential care for older people is an area of growing concern to many Western countries. Nurse practitioners offer opportunities to improve the quality of residential care.
What is known about the topic?The lack of registered nurses generally and the more critical shortage in residential care is well known.
What does this paper add?This paper explains the impact on the current and future viability and the quality of registered nurse services in an area of service where acuity continues to rise and the demand for nursing services is increasing.
What are the implications for practitioners?Nurses in older care settings often express a sense of isolation and note limited career development despite their passion for serving the frail older person. The establishment of nurse practitioner (gerontology) roles offers the potential for improved quality of clinical care for residents and clinical champions for development of nursing services.
Why did they leave and what can they tell us? Allied health professionals leaving rural settings
Authors: O'Toole Kevin , Schoo Adrian , Hernan Andrea
Published: March 2010

The aim of this paper is to explore the lack of retention of allied health professionals in rural areas in Victoria, Australia. A structured telephone interview was used to elicit responses from 32 allied health professionals from south-west, central-west and north-east Victoria about their working experiences and reasons for resignation. The data revealed that work experiences in rural areas can be summarised within three domains: organisational, professional and personal/community. Under the organisational domain the participants were mainly focussed on the way in which their work arrangements require them to be both more generalist in their approach to day-to-day work, and more expansive in shouldering management style functions in the workplace. Under the professional domain there were three major issues; clinical, career and education/training. The personal/community domain focussed on issues to do with their affinity for their workplace as well as their location in a rural place. The attempts by government to address some of the leading factors for retention of allied health professionals are perhaps too narrowly focussed on the public sector and could encompass a wider approach.
What is known about the topic?Although recruitment and retention of allied health professionals in rural areas is widely discussed, the professionals have not been interviewed about their experiences once they have left rural employment.
What does this paper add?This paper provides detailed insights into the reasons why allied health professionals leave their positions in rural areas and the positive and negative aspects of living and working in a rural area. The results of this study contribute to the development of better policy models for recruitment and retention of allied health professionals in rural areas.
What are the implications for practitioners?The factors that influence whether allied health professionals stay or leave rural areas is of concern for health policy makers at state and federal levels. This paper provides information for the extension and development of programs to attenuate rural leakage of professionals.
Adsorption and Dipole Surface Orientational Order at Liquid Surfaces
Authors: Law Bruce M. , Cho Jae-Hie , Carpenter John , Smith Dan
Published: March 2010

Adsorption at surfaces has been a topic of considerable interest since Gibbs introduced his famous adsorption equation in 1875. However, only in the past few years, has adsorption become quantitatively understood (at least in the vicinity of a critical point). Adsorption is far more complex than perhaps one might envision. At the liquid–vapour interface of a binary liquid mixture one can find: (i) strong adsorption (where one component completely saturates the surface); (ii) competitive adsorption (where the two species compete for surface sites); and (iii) dipole surface orientational order (due to dipole-image dipole interactions). In this paper we discuss these various modes of adsorption.
An Alternative Platform for the Assessment of Hückel and Möbius Transition States in Concerted Reactions
Authors: Hennigar Kurt H. R. , Langler Richard F.
Published: March 2010

A novel approach to the evaluation of Hückel and Möbius transition states is described. It employs incipient π-bond orders, opi,k and *pi,k. A complete analytical scheme is developed for monocyclic p-orbital arrays in both Hückel and Möbius transition states for both thermal and photochemical reactions. Assessment of monocyclic transition states does not require the calculation of explicit incipient π-bond orders. Transition states featuring polycyclic p-orbital arrays may be assessed by means of calculated opi,k and *pi,k values. A more detailed presentation is available in the Accessory Publication.
Interactions of Visinin-like Proteins with Phospho-inositides
Authors: Braunewell Karl-Heinz , Paul Blessy , Altarche-Xifro Wassim , Noack Cornelia , Lange Kristian , Hofmann Andreas
Published: March 2010

The subcellular membrane localization of neuronal calcium sensor (NCS) proteins in living cells, such as Visinin-like Proteins-1 (VILIP-1) and VILIP-3, differs substantially. We have followed the hypothesis that the differential localization may be due to the specific binding capabilities of individual VILIPs for phosphatidylinositol phosphates (PIPs). Several highly conserved lysine residues in the N-terminal region could provide favourable electrostatic interactions. Molecular modelling results support a binding site for phospho-inositides in the N-terminal area of VILIP-1, and the involvement of the conserved N-terminal lysine residues in binding the phospho-inositol head group. Experimentally, the binding of VILIP-1 to inositol derivatives was tested by a PIP strip assay, which showed the requirement of phosphorylation of the inositol group for the interaction of the protein with PIPs. Monolayer adsorption measurements showed a preference of VILIP-1 binding to PI(4,5)P2 over PI(3,4,5)P3. The co-localization of VILIP-1 with PI(4,5)P2 at the cell surface membrane in hippocampal neurons further supports the idea of direct interactions of VILIP-1 with PIPs in living cells.
Structure and Characterization of a Novel 3D Lead Phosphonate Metal - Organic Framework with Cationic Layer Based on Weak Pb - O(N) Contact
Authors: Ma Kui-Rong , Zhang Dao-Jun , Zhu Yu-Lan
Published: March 2010

A novel lead-phosphonate, [Pb2(HL)]·(NO3)·2(H2O) 1 (H4L = H2O3PCH2N(C4H8)NCH2PO3H2
N,N′-piperazinebis(methylenephosphonic acid), so HL = O3PCH2NH(C4H8)NCH2PO3), has been hydrothermally synthesized and characterized by elemental analysis, IR, TG-DTA, and X-ray single-crystal diffraction. Compound 1 possesses a 2D cationic layer structure built from inorganic chains with three types of eight-membered rings arranged in an ABAC manner. In 1, both crystallographic distinct Pb(II) ions adopt three-coordination geometry, and a counter anion NO3
– and two lattice water molecules occupy the voids between 2D layers. After the removal of solvent, the size of tunnel formed by 2D layers is 137.9 Å3 per unit cell, comprising 17.0% of the crystal volume based on the crystal structure. When the bond length of Pb–O(N) extended to 3.10 Å, a 3D metal–organic framework was constructed via long Pb–O(N) contacts, simultaneously accompanied by the hemi- to holo-directed transition in coordination geometry of Pb(II). Except for the long Pb–O contacts, a 3D supramolecular network is also formed by hydrogen bonds (N–H···O, O–H···O, and C–H···O), van der Waals forces as well as electrostatic interactions. The result of fluorescence measurements indicates that 1 shows a fluorescent emission band at 465 nm (λexcitation = 215 nm).
Structural Variation and Magneto-Structural Correlation in Two New Dinuclear Bis(µ2-Phenoxo)-Bridged CuII Schiff-Base Complexes: Catalytic Potential for the Peroxidative Oxidation of Cycloalkanes
Authors: Basak Subhra , Sen Soma , Roy Partha , Gómez-García Carlos J. , Hughes David L. , Butcher Ray J. , Garribba Eugenio , Mitra Samiran
Published: March 2010

Two new dinuclear bis(μ2-phenoxo)-bridged copper(ii) complexes [Cu(NCS)L1]2 (1) and [Cu(NCS)L2]2 (2) have been synthesized using two tridentate NNO-donor Schiff-base ligands, L1H (Me2N(CH2)3N=CHC6H3(OMe)(OH)) and L2H (Me2N(CH2)3N=C(CH3)C6H4(OH)), respectively. They have been characterized by elemental analyses, IR, UV-visible, and electron paramagnetic resonance (EPR) spectroscopy, cyclic voltammetry, and magnetic susceptibility measurements. X-Ray single-crystal structures reveal a central Cu2O2 core in each complex with an isothiocyanate ligand coordinated terminally to each metal centre. The coordination environments around the CuII ions in 1 and 2 are a distorted trigonal bipyramid and a quasi-regular square pyramid, respectively, with significant differences in the Cu–O–Cu bridging angles (100.22(5)° for 1 and 95.64(7)° for 2). Although both CuII dimers present intradimer antiferromagnetic exchange interactions, the magnitudes of the coupling constants in 1 and 2 (J = –119(1) and –0.361(3) cm–1, respectively) are quite different as a result of the different coordination geometries and Cu–O–Cu bridging angles. Both complexes act as promising catalysts or catalyst precursors for the efficient peroxidative oxidation of cycloalkanes (cyclohexane and cycloheptane) to the corresponding cyclic alcohols and ketones, with maximum overall yields of 53% and 56% for 1 and 2, respectively.
Coordination Polymers with a Bulky Perylene-Based Tetracarboxylate Ligand: Syntheses, Crystal Structures, and Luminescent Properties
Authors: Liu Chun-Sen , Hu Min , Ma Song-Tao , Zhang Qiang , Zhou Li-Ming , Gao Li-Jun , Fang Shao-Ming
Published: March 2010

To explore the coordination possibilities of perylene-based ligands with a larger conjugated π-system, four ZnII, MnII, and CoII coordination polymers with perylene-3,4,9,10-tetracarboxylate (ptc) and the chelating 1,10-phenanthroline (phen) ligands were synthesized and characterized: {[Zn2(ptc)(phen)2](H2O)10}∞ (1), {[Zn3(ptc)(OH)2(phen)2](H2O)3}∞ (2), {[Mn(ptc)0.5(phen)(H2O)2](H2O)1.5}∞ (3), and {[Co(ptc)0.5(phen)(H2O)2](H2O)2.5}∞ (4). Structural analysis reveals that complexes 1 and 2 both take one-dimensional polymeric chain structures with dinuclear and trinuclear units as nodes, respectively, which are further extended via the accessorial secondary interchain interactions, such as C–H···O H-bonding or aromatic π···π stacking interactions, to give rise to the relevant higher-dimensional frameworks. Compound 3 has a two-dimensional sheet structure that is further assembled to form a three-dimensional framework by interlayer π···π stacking interactions. Complex 4 is a one-dimensional ribbon-like array structure that is interlinked by the co-effects of intermolecular π···π stacking and C–H···π supramolecular interactions, resulting in a higher-dimensional framework from the different crystallographic directions. Moreover, complexes 1–4 exhibit strong solid-state luminescence emissions at room temperature, which mainly originate from intraligand π→π* transitions of ptc.
On the Solid-State Isomerization of Terpinolene Tetrabromide
Authors: Bernhardt Paul V. , Carman Raymond M. , Le Tri T.
Published: March 2010

The isomerization of terpinolene tetrabromide from the cis-2,4- (diaxial) dibromo isomer (A) to the more stable trans-2,4- (equatorial–axial) compound (B) has been investigated in the solid state. The progress of the solid-state reaction as a function of time was followed by solution NMR analysis, and, more effectively, by micropowder X-ray diffraction of the bulk material in situ. Characterization of the solid-state reaction mixture is facilitated by the existence of X-ray crystal structures of both compounds A (monoclinic) and B (reported previously) in addition to a new triclinic polymorph of compound A reported herein, all three forms being observed by powder X-ray diffraction.
Similar irradiance-elicited plasticity of leaf traits in saplings of 12 tropical rainforest tree species with highly different leaf masstoarea ratio
Authors: Coste Sabrina , Roggy Jean-Christophe , Sonnier Gregory , Dreyer Erwin
Published: March 2010

Leaf traits of tropical tree species display an important inter-specific diversity, as detected for instance in the large range of values of leaf mass : area ratio (LMA). They also demonstrate a large irradiance-elicited plasticity, but there is still debate whether this plasticity differs among species. To address this question, leaf traits were recorded on saplings from 12 rainforest tree species in French Guiana, grown under approximately 5, 10 and 20% relative irradiance. Fifteen structural and physiological leaf traits related to photosynthesis were measured. The irradiance-elicited plasticity was quantified using a relative distance plasticity index. A large inter-specific diversity was detected for all leaf traits. A principal component analysis opposed species with a large mass-based photosynthesis, respiration, N content and photosynthetic nitrogen use efficiency, to species with a large leaf mass : area ratio, LMA. The two pioneer species used in this study displayed the largest photosynthetic capacity (and lowest LMA) and ranked at one end of the species continuum. Relative irradiance affected almost all traits with the exception of mass-based photosynthesis. A weak interaction was found between species and relative irradiance and the species ranking was maintained among relative irradiance treatments for the majority of the traits. A principal component analysis of the values of relative-distance plasticity index failed to reveal any consistent patterns of traits or species. We concluded that irradiance-elicited plasticity of leaf traits was similar among species irrespective of LMA and successional status, despite the occurrence of a large inter-specific diversity for the investigated traits.
Incorrect report of cryptic species within Chrysomya rufifacies (Diptera:Calliphoridae)
Authors: Lessard B. D. , Wallman J. F. , Dowton M.
Published: March 2010

Chrysomya rufifacies is an ecologically and forensically important blowfly, widespread in Australasia, the Orient and the Americas. The recent molecular studies of Wallman et al. (2005) showed significant levels of nucleotide divergence between Australian populations of this species based on the cytochrome oxidase subunit two (COII) gene, suggesting that Ch. rufifacies is in fact two species. The present study used COII to verify the existence of these two putative species. A 642-bp fragment of COII was sequenced from 37 specimens sampled from 35 diverse Australian geographical locations and analysed using the Kimura-two-parameter distance model and Bayesian methods. Surprisingly, all Ch. rufifacies sequences demonstrated typical levels of mean intraspecific variation (mean = 0.042%, range = 0.000–0.315%, standard error = 0.003) and were resolved as a monophyletic group on the Bayesian tree. Reassessment of the original COII data of Wallman et al. (2005) showed that the high nucleotide divergence within Ch. rufifacies was attributed to two COII sequences actually derived from specimens of Lucilia porphyrina. Ultimately, this study does not support the hypothesis that Australian Ch. rufifacies comprises two cryptic species but instead confirms its existing status as a single taxon.
Neural imaging to track mental states while using an intelligent tutoring system
Authors: Anderson John R. , Betts Shawn , Ferris Jennifer L. , Fincham Jon M.
Published: March 2010

Hemodynamic measures of brain activity can be used to interpret a student's mental state when they are interacting with an intelligent tutoring system. Functional magnetic resonance imaging (fMRI) data were collected while students worked with a tutoring system that taught an algebra isomorph. A cognitive model predicted the distribution of solution times from measures of problem complexity. Separately, a linear discriminant analysis used fMRI data to predict whether or not students were engaged in problem solving. A hidden Markov algorithm merged these two sources of information to predict the mental states of students during problem-solving episodes. The algorithm was trained on data from 1 day of interaction and tested with data from a later day. In terms of predicting what state a student was in during a 2-s period, the algorithm achieved 87% accuracy on the training data and 83% accuracy on the test data. The results illustrate the importance of integrating the bottom-up information from imaging data with the top-down information from a cognitive model.
Failure to advance: resource logic for early venture failure
Authors: Saxton M.K. , Saxton T. , Steen J. , Verreynne M.
Published: March 2010

New ventures play an important role in economic growth. The resource logic underlying how these firms develop in the early stages, however, has not received adequate attention in the literature. This paper examines the launch trajectories of embryonic ventures. We propose a configurational model of these trajectories based on the resources and stages required to establish a viable commercial entity. Potential launching paths are identified, from the inception of a new product/service idea through to success outcomes, including rapid, independent sales growth, stabilized profit, acquisition or Initial Public Offering. We argue that embryonic firms must balance the development of product, financial and human resources through waves of resource accumulation as they move through different stages of development. We summarize our arguments in a model of venture evolution.
Not a Sure Thing: Fitness, Probability, and Causation
Authors: Walsh Denis M.
Published: March 2010

In evolutionary biology changes in population structure are explained by citing trait fitness distribution. I distinguish three interpretations of fitness explanations—the Two-Factor Model, the Single-Factor Model, and the Statistical Interpretation—and argue for the last of these. These interpretations differ in their degrees of causal commitment. The first two hold that trait fitness distribution causes population change. Trait fitness explanations, according to these interpretations, are causal explanations. The last maintains that trait fitness distribution correlates with population change but does not cause it. My defense of the Statistical Interpretation relies on a distinctive feature of causation. Causes conform to the Sure Thing Principle. Trait fitness distributions, I argue, do not.
Self‐citation in Chinese biomedical journals
Authors: Xue‐Li LIU , Mei‐Ying WANG
Published: March 2010

We investigated the self‐citation rates of 884 Chinese biomedical journals, including 185 general medicine journals, 96 preventive medicine journals, 103 Chinese traditional medicine journals, 66 basic medicine journals, 370 clinical medicine journals, and 64 pharmaceutical journals. The average self‐citation rates of these journals for the years 2005–2007 were 0.113 ± 0.124, 0.099 ± 0.098 and 0.092 ± 0.089, respectively, i.e. a downward trend year by year. The upper limits of normal values of self‐citation rates for the same period were 0.316, 0.260 and 0.238, respectively. A significant difference was found in self‐citation rate between biomedical journals of different subjects. 52 Chinese biomedical journals had no self‐citation in 2007. The total citation frequency and impact factor of these 52 biomedical journals were 263 and 0.206, respectively, which were very much lower than the average levels of all Chinese biomedical journals in 2007. A self‐citation rate higher than the upper limit was considered as excessive self‐citation: 62 (7.01%), 68 (7.69%) and 66 (7.47%) biomedical journals showed excessive self‐citation in the years 2005–2007, respectively. However, a certain amount of self‐citation is reasonable and necessary.
Open access publishing: a viable solution for society publishers
Authors: COONEY‐McQUAT Sarah , BUSCH Stefan , KAHN Deborah
Published: March 2010

The open access (OA) business model has established itself as a viable alternative to traditional subscription‐based publishing and is an option that societies should now realistically consider for their journals. This paper outlines how the OA model can work for societies, and presents a number of case studies that demonstrate how it is already working in practice.
Book Reviews
Authors: JUBB Michael
Published: March 2010

Open Access – What Are the Economic Benefits? A Comparison of the United Kingdom, Netherlands and Denmark John Houghton Knowledge Exchange, 2009, 22pp. Available from http://www.knowledge‐exchange.info/
Book Reviews
Authors: Roos Anna Marie
Published: March 2010

Getting Published: A Companion for the Humanities and Social Sciences Gerald Jackson and Marie Lenstrup Copenhagen, NIAS Press, 2009, 296 pp., illustrated ISBN 9788791114762, £30/$60, hbk ISBN 9788791114779, £13.99/$25, pbk
Book Reviews
Authors: McILROY Thad
Published: March 2010

Digitize This Book: The Politics of New Media or Why We Need Open Access Now Gary Hall Minneapolis, University of Minnesota Press, 2008, 312 pp. ISBN 978 0 8166 4871 9, $19.95, pbk
Book Reviews
Authors: McILROY Thad
Published: March 2010

The Brave New World of Publishing: The Symbiotic Relationship Between Printing and Book Publishing Manfred H. Breede Oxford, Chandos Publishing, 2008, 210 pp. ISBN 1 84334 439 4, £39.95 pbk, £59.95 hbk
Book Reviews
Authors: JUBB Michael
Published: March 2010

The Future of the Academic Journal Edited by Bill Cope and Angus Phillips Chandos Publishing, 2009, 391pp. ISBN 978 1 84334 416 2, £55.00/US$95.00/€70.00 paperback
Roles of the Mdm10, Tom7, Mdm12, and Mmm1 Proteins in the Assembly of Mitochondrial Outer Membrane Proteins in Neurospora crassa
Authors: Wideman Jeremy G. , Go Nancy E. , Klein Astrid , Redmond Erin , Lackey Sebastian W.K. , Tao Tan , Kalbacher Hubert , Rapaport Doron , Neupert Walter , Nargang Frank E.
Published: March 2010

The Mdm10, Mdm12, and Mmm1 proteins have been implicated in several mitochondrial functions including mitochondrial distribution and morphology, assembly of β-barrel proteins such as Tom40 and porin, association of mitochondria and endoplasmic reticulum, and maintaining lipid composition of mitochondrial membranes. Here we show that loss of any of these three proteins in Neurospora crassa results in the formation of large mitochondrial tubules and reduces the assembly of porin and Tom40 into the outer membrane. We have also investigated the relationship of Mdm10 and Tom7 in the biogenesis of β-barrel proteins. Previous work showed that mitochondria lacking Tom7 assemble Tom40 more efficiently, and porin less efficiently, than wild-type mitochondria. Analysis of mdm10 and tom7 single and double mutants, has demonstrated that the effects of the two mutations are additive. Loss of Tom7 partially compensates for the decrease in Tom40 assembly resulting from loss of Mdm10, whereas porin assembly is more severely reduced in the double mutant than in either single mutant. The additive effects observed in the double mutant suggest that different steps in β-barrel assembly are affected in the individual mutants. Many aspects of Tom7 and Mdm10 function in N. crassa are different from those of their homologues in Saccharomyces cerevisiae.
TopoGSA: network topological gene set analysis
Authors: Glaab Enrico , Baudot Anaïs , Krasnogor Natalio , Valencia Alfonso
Published: March 2010

Summary: TopoGSA (Topology-based Gene Set Analysis) is a web-application dedicated to the computation and visualization of network topological properties for gene and protein sets in molecular interaction networks. Different topological characteristics, such as the centrality of nodes in the network or their tendency to form clusters, can be computed and compared with those of known cellular pathways and processes.

Availability: Freely available at http://www.infobiotics.net/topogsa

Contact:  nxk@cs.nott.ac.uk; avalencia@cnio.es
Varicella Vaccination in Children With Inflammatory Bowel Disease Receiving Immunosuppressive Therapy
Authors: Lu Ying , Bousvaros Athos
Published: March 2010

Children with inflammatory bowel disease (IBD) are often receiving chronic immunosuppressive therapy to stay in clinical remission; however, these therapies also put patients at risk for infections. Therefore, it is important to immunize children to minimize vaccine‐preventable infections. However, there is a paucity of data on immune response to vaccines in patients with IBD. Current guidelines recommend that patients with IBD receive inactivated vaccines but suggest against immunizing immunosuppressed patients having IBD with live vaccines such as varicella. Unfortunately, the recommendation to not vaccinate with varicella was not based on any data. We present a case series of children with IBD receiving immunosuppressive therapy who tolerated and had a good immune response to varicella vaccine. We also review the literature and demonstrate that studies in other immunocompromised populations suggest that varicella vaccine is generally well tolerated and immunogenic. We also argue that it is important to weigh the benefits against risks with individual patients having IBD to decide whether varicella vaccination should be considered. Additional studies evaluating the safety and immunogenicity of varicella vaccine in patients with IBD are needed.
Indications to Upper Gastrointestinal Endoscopy in Children With Dyspepsia
Authors: Guariso G , Meneghel A , Pozza L Visonà Dalla , Romano C , Dall'Oglio L , Lombardi G , Conte S , Calacoci M , Campanozzi A , Nichetti C , Piovan S , Zancan L , Facchin P
Published: March 2010

Objectives:

The objective of the study was to ascertain the appropriateness of indications for upper gastrointestinal (UGI) endoscopy in children with dyspepsia.

Methods:

We used the RAND/University of California at Los Angeles method to investigate the appropriateness of the opinions of a panel of experts. The panel judged 2304 theoretical patient scenarios defined by a combination of demographic and clinical variables. Descriptive and multivariate logistic regression analyses were performed.

Results:

The panel rated UGI endoscopy as appropriate in 27.2% of cases, inappropriate in 14.3%, and dubious in 58.5%. Disagreement emerged for 21% of cases. UGI endoscopy was considered increasingly appropriate in cases with a positive family history of peptic ulcer and/or Helicobacter pylori infection (odds ratio [OR] 8.518, P < 0.0001), when dyspepsia interfered with activities of daily living (“sleep” OR 7.540, P < 0.0001; “normal activities” OR 5.725, P < 0.0001), and when patients were older than 10 years (“≤10 years” OR 0.310, P < 0.0001) the longer the duration (“0–2 months” OR 0.002, P < 0.0001; “3–5 months” OR 0.059, P < 0.0001; “6–11 months” OR 0.516, P = 0.0005) and the greater the severity (“mild” OR 0.002, P < 0.0001; “moderate” OR 0.013, P < 0.0001) of their dyspeptic symptoms.

Conclusions:

UGI endoscopy is not appropriate for all children with dyspeptic symptoms, but only for cases with a family history of peptic ulcer and/or Helicobacter pylori infection, older than 10 years of age, with symptoms persisting for more than 6 months and severe enough to affect activities of daily living.
Hearing is not necessarily believing in nocturnal anurans
Authors: Richardson Christina , Gomez Doris , Durieux Romain , Théry Marc , Joly Pierre , Léna Jean-Paul , Plénet Sandrine , Lengagne Thierry
Published: March 2010

The recent discovery of the use of visual cues for mate choice by nocturnal acoustic species raises the important, and to date unaddressed, question of how these signals affect the outcome of mate choice predicted by female preference for male calls. In order to address this question, we presented female
Hyla arborea
tree frogs with a series of choices between combinations of acoustic and visual cues of varying quality in nocturnal conditions. While females exhibited the expected preference for a combination of attractive values for visual and acoustic signals over combinations of unattractive values for both signals, when presented with conflicting acoustic and visual cues, they equally adopted one of two strategies, preferring either attractive calls or intense vocal sac coloration. This constitutes novel evidence that the outcome of mate choice, as predicted on the basis of male calling quality, can be drastically different when additional communication modalities—in this case vision—are taken into account. These results also highlight the possible existence of individual variation in female rules for cue prioritization. The implications of these results for the study of mate choice in nocturnal acoustic species are discussed.
Phenotypic plasticity in juvenile jellyfish medusae facilitates effective animal–fluid interaction
Authors: Nawroth J. C. , Feitl K. E. , Colin S. P. , Costello J. H. , Dabiri J. O.
Published: March 2010

Locomotion and feeding in marine animals are intimately linked to the flow dynamics created by specialized body parts. This interaction is of particular importance during ontogeny, when changes in behaviour and scale challenge the organism with shifts in fluid regimes and altered functionality. Previous studies have indicated that Scyphozoan jellyfish ontogeny accommodates the changes in fluid dynamics associated with increasing body dimensions and velocities during development. However, in addition to scale and behaviour that—to a certain degree—underlie the control of the animal, flow dynamics are also dependent on external factors such as temperature. Here, we show phenotypic plasticity in juvenileAurelia auritamedusae, where morphogenesis is adapted to altered fluid regimes imposed by changes in ambient temperature. In particular, differential proportional growth was found to compensate for temperature-dependent changes in viscous effects, enabling the animal to use adhering water boundary layers as ‘paddles’—and thus economize tissue—at low temperatures, while switching to tissue-dominated propulsion at higher temperatures where the boundary layer thickness is insufficient to serve for paddling. This effect was predicted by a model of animal–fluid interaction and confirmed empirically by flow-field visualization and assays of propulsion efficiency.
Bayesian island biogeography in a continental setting: the Rand Flora case
Authors: Sanmartín Isabel , Anderson Cajsa Lisa , Alarcon Marisa , Ronquist Fredrik , Aldasoro Juan José
Published: March 2010

We here explore the use of a Bayesian approach to island biogeography for disentangling the evolutionary origins of a continental-scale floristic pattern, the enigmatic ‘Rand Flora’. The existence of disjunct distributions across many plant lineages between Macaronesia–northwest Africa, Horn of Africa–southern Arabia and east–south Africa has long intrigued botanists, but only now can we start analysing it within a statistical framework.

Phylogenetic and distributional data from 13 plant lineages exhibiting this disjunct distribution were analysed to estimate area carrying capacities and historical rates of biotic exchange between areas. The results indicate that there has been little exchange between southern Africa and the northern African region, and that this exchange occurred via east Africa. Northwest Africa–Macaronesia shows the smallest carrying capacity but highest dispersal rate with other regions, suggesting that its flora was built up by immigration of lineages, probably from the Mediterranean region and western Asia. In contrast, southern Africa shows the highest carrying capacity and lowest dispersal rate, suggesting a flora formed by
in situ
diversification.

We discuss further improvements of the method for addressing more complex hypotheses, such as asymmetric dispersal between regions or repeated cyclical events.
Taste-rejection behaviour by predators can promote variability in prey defences
Authors: Halpin Christina G. , Rowe Candy
Published: March 2010

The evolution and maintenance of toxicity in a prey population is a challenge to evolutionary biologists if the investment in toxin does not benefit the individual. Recent experiments suggest that taste-rejection behaviour enables predators to selectively ingest less toxic individuals, which could stabilize investment in defences. However, we currently do not know if taste rejection of defended prey is accurate across different contexts, and that prey always benefit according to their investment. Using avian predators, we show that the rejection probability does not solely depend on the investment in defence by an individual, but also on the investment by other individuals in the same population. Therefore, taste rejection by predators could lead to destabilization in the investment in defences, and allow variability in prey defences to exist.
Hooke's figurations: a figural drawing attributed to Robert Hooke
Authors: Hunter Matthew C.
Published: March 2010

The experimental philosopher Robert Hooke (1635–1703) is known to have apprenticed to the leading painter Peter Lely on his first arrival in London in the late 1640s. Yet the relevance of Hooke's artistic training to his mature draughtsmanship and identity has remained unclear. Shedding light on that larger interpretive problem, this article argues for the attribution to Hooke of a figural drawing now in Tate Britain (T10678). This attributed drawing is especially interesting because it depicts human subjects and bears Hooke's name functioning as an artistic signature, both highly unusual features for his draughtsmanship. From evidence of how this drawing was collected and physically placed alongside images by leading artists in the early eighteenth century, I suggest how it can offer new insight into the reception of Hooke and his graphic work in the early Enlightenment.
Mating tactics determine patterns of condition dependence in a dimorphic horned beetle
Authors: Knell Robert J. , Simmons Leigh W.
Published: March 2010

The persistence of genetic variability in performance traits such as strength is surprising given the directional selection that such traits experience, which should cause the fixation of the best genetic variants. One possible explanation is ‘genic capture’ which is usually considered as a candidate mechanism for the maintenance of high genetic variability in sexual signalling traits. This states that if a trait is ‘condition dependent’, with expression being strongly influenced by the bearer's overall viability, then genetic variability can be maintained via mutation-selection balance. Using a species of dimorphic beetle with males that gain matings either by fighting or by ‘sneaking’, we tested the prediction of strong condition dependence for strength, walking speed and testes mass. Strength was strongly condition dependent only in those beetles that fight for access to females. Walking speed, with less of an obvious selective advantage, showed no condition dependence, and testes mass was more condition dependent in sneaks, which engage in higher levels of sperm competition. Within a species, therefore, condition dependent expression varies between morphs, and corresponds to the specific selection pressures experienced by that morph. These results support genic capture as a general explanation for the maintenance of genetic variability in traits under directional selection.