bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved electron density measurements at Jicamarca
Authors: Rodrigues F. S. , Nicolls M. J. , Hysell D. L.
Published: November 2007

Taking into account the effects of electron Coulomb collisions, incoherent scatter (IS) radar cross sections for probing angles close to perpendicular to the magnetic field have been calculated and used to correct backscattered power profiles measured with the Jicamarca incoherent scatter radar so that they accurately represent the height variation of the ionospheric electron density. The corrected power profiles are compared with simultaneous Faraday rotation measurements of electron density. The profiles agree within the measurements uncertainties. This result improves electron density measurements at Jicamarca, since power measurements are less sensitive to clutter and interference than Faraday rotation measurements. The results can be used to correct Jicamarca long‐term IS power measurements.
Very low frequency sferic bursts, sprites, and their association with lightning activity
Authors: Marshall R. A. , Inan U. S. , Lyons W. A.
Published: November 2007

Recent observations have revealed the occurrence of burst‐like VLF activity, lasting from tens of milliseconds up to a few seconds, associated with the onset of many sprites. These “sferic bursts” are thought to be due to the horizontal in‐cloud component of lightning activity, since they have been observed to propagate only short distances (a few hundred kilometers) in the Earth‐ionosphere waveguide and are generally not reported by lightning detection networks. The possible involvement of in‐cloud lightning in sprite production has been previously suggested on the basis of the observed long delays and spatial displacement between causative cloud‐to‐ground (CG) discharges and sprite events. In this work, we investigate the association between sprites and sferic bursts using VLF data and a large set of sprite observations between 1995 and 2000. We compare the occurrence of sferic bursts in association with sprites for thousands of observations through many different dates and thunderstorms. Results indicate that sprite‐causative CGs are more commonly found in association with bursts of sferic activity than those CG discharges without sprites and that, furthermore, the distribution of sferic burst VLF energy is significantly higher for sprite‐associated events. We further investigate the source of these bursts by comparing VLF data to Lightning Mapping Array (LMA) data of VHF pulses due to lightning. Such comparisons show that most sferic burst events can be explained as radiation from the horizonal in‐cloud components of +CG lightning, as detected by the LMA.
GPR119, a novel G protein‐coupled receptor target for the treatment of type 2 diabetes and obesity
Authors: Overton H A , Fyfe M C T , Reynet C
Published: November 2007

GPR119 is a G protein‐coupled receptor expressed predominantly in the pancreas (β‐cells) and gastrointestinal tract (enteroendocrine cells) in humans. De‐orphanization of GPR119 has revealed two classes of possible endogenous ligands, viz., phospholipids and fatty acid amides. Of these, oleoylethanolamide (OEA) is one of the most active ligands tested so far. This fatty acid ethanolamide is of particular interest because of its known effects of reducing food intake and body weight gain when administered to rodents. Agonists at the GPR119 receptor cause an increase in intracellular cAMP levels via Gαs coupling to adenylate cyclase. In vitro studies have indicated a role for GPR119 in the modulation of insulin release by pancreatic β‐cells and of GLP‐1 secretion by gut enteroendocrine cells. The effects of GPR119 agonists in animal models of diabetes and obesity are reviewed, and the potential value of such compounds in future therapies for these conditions is discussed.

British Journal of Pharmacology (2008) 153, S76–S81; doi:10.1038/sj.bjp.0707529; published online 26 November 2007
Effects of KP‐496, a novel dual antagonist at the cysteinyl leukotriene receptor 1 and the thromboxane A2 receptor, on airway obstruction in guinea pigs
Authors: Ishimura M , Suda M , Morizumi K , Kataoka S , Maeda T , Kurokawa S , Hiyama Y
Published: November 2007

Background and purpose:

KP‐496 is a novel dual antagonist for cysteinyl leukotriene receptor 1 (CysLT1) and thromboxane A2 (TXA2) receptor (TP). The aim of this study was to evaluate the pharmacological profile of inhaled KP‐496 and its effects on airway obstruction.

Experimental approach:

Antagonist activities of inhaled KP‐496 were investigated using bronchoconstriction induced in guinea pigs by LTD4 or U46619, a stable TXA2 mimetic. Guinea pigs sensitized with injections of ovalbumin were used to assess the effects of inhaled KP‐496 on bronchoconstriction induced by antigen (i.v.). Another set of guinea pigs were sensitized and challenged with ovalbumin by inhalation and the effects of inhaled KP‐496 on immediate and late airway responses and airway hyperresponsiveness were investigated.

Key results:

KP‐496 significantly inhibited LTD4‐ and U46619‐induced bronchoconstriction in a dose‐dependent manner. The inhibitory effects of KP‐496 (1%) were comparable to those of montelukast (a CysLT1 antagonist, p.o., 0.3 mg kg−1) or seratrodast (a TP antagonist, p.o., 3 mg kg−1). KP‐496 (1%) and oral co‐administration of montelukast (10 mg kg−1) and seratrodast (20 mg kg−1) significantly inhibited antigen‐induced bronchoconstriction, whereas administration of montelukast or seratrodast separately did not inhibit antigen‐induced bronchoconstriction. KP‐496 exhibited dose‐dependent and significant inhibitory effects on the immediate and late airway responses and airway hyperresponsiveness following antigen challenge.

Conclusions and implications:

KP‐496 exerts effects in guinea pigs which could be beneficial in asthma. These effects of KP‐496 were greater than those of a CysLT1 antagonist or a TP antagonist, in preventing antigen‐induced airway obstruction.

British Journal of Pharmacology (2008) 153, 669–675; doi:10.1038/sj.bjp.0707602; published online 26 November 2007
Effect of the Gouy phase on the coherent phase control of chemical reactions
Authors: Gordon Robert J. , Barge Vishal J.
Published: November 2007

We show how the spatial phase of a focused laser beam may be used as a tool for controlling the branching ratio of a chemical reaction. Guoy discovered [Acad. Sci., Paris, C. R. 110, 1250 (1890)] that when an electromagnetic wave passes through a focus its phase increases by π. In a coherent control scheme involving the absorption of n photons of frequency ωm and m photons of frequency ωn, the overall phase shift produced by the Gouy phase is (n−m)π. At any given point in space, this phase shift is identical for all reaction products. Nevertheless, if the yields for different reaction channels have different intensity dependencies, the Gouy phase produces a net phase lag between the products that varies with the axial coordinate of the laser focus. We obtain here analytical and numerical values of this phase as the laser focus is scanned across the diameter of the molecular beam, taking into account the Rayleigh range and astigmatism of the laser beam and saturation of the transition. We also show that the modulation depth of the interference pattern may be increased by optimizing the relative intensities of the two fields.
Infrared spectroscopy of physisorbed and chemisorbed N2 in the Pt(111)(3×3)N2 structure
Authors: Gustafsson K. , Karlberg G. S. , Andersson S.
Published: November 2007

Using infrared spectroscopy and low electron energy diffraction, we have investigated the adsorption of N2, at 30K, on the Pt(111) and the Pt(111)(1×1)H surfaces. At monolayer coverage, N2 orders in commensurate (3×3) structures on both surfaces, and we propose that the unit cells contain four molecules in each case. The infrared spectra reveal that N2 exclusively physisorbs on the Pt(111)(1×1)H surface, while both physisorbed and chemisorbed N2 is detected on the Pt(111) surface. Physisorbed N2 is the majority species in the latter case, and the two adsorption states show an almost identical uptake behavior, which indicates that they are intrinsic constituents of the growing (3×3) N2 islands. An analysis of the infrared absorbance data, based on a simple scaling concept suggested by density functional theory calculations, supports a model in which the (3×3) unit cell contains one chemisorbed molecule in end-on atop configuration and three physisorbed molecules. We note that a classic “pinwheel” structure on a hexagonal lattice, with the end-on chemisorbed N2 molecules acting as “pins,” is compatible with this composition.
Gallium-nitride-based microcavity light-emitting diodes with air-gap distributed Bragg reflectors
Authors: Sharma Rajat , Choi Yong-Seok , Wang Chiou-Fu , David Aurélien , Weisbuch Claude , Nakamura Shuji , Hu Evelyn L.
Published: November 2007

We report on the realization of highly efficient InGaN microcavity light-emitting diodes incorporating a high index contrast air-gap distributed Bragg reflector (DBR). Detailed analysis deduces an effective cavity length of ∼500nm and cavity mode orders of 5 and 6 for measured Fabry-Pérot fringes. A value reflectivity of ∼70% was determined for the 4.5 period air∕Al0.08Ga0.92N DBR through the analysis of cavity finesse based on the angle-resolved photoluminescence (PL) data. A fivefold improvement in light extraction efficiency was verified by electrical probing as well as angle-resolved PL measurements.
Stability of highly shifted equilibria in a large aspect ratio low-field tokamak
Authors: Gourdain P.-A. , Leboeuf J.-N. , Neches R. Y.
Published: November 2007

In the long run, the economics of fusion will dictate that reactors confine large plasma pressure rather efficiently. A possible route manifests itself as equilibria with large shift of the plasma magnetic axis. This shift compresses the flux surfaces on the outer part of the plasma, hereby increasing the allowable plasma pressure a machine can confine for a given toroidal magnetic field, which is the main cost of the device. As a first step toward a reactor, we propose investigating the stability of such configurations in a low magnetic field high aspect ratio machine. By focusing our arguments solely on the shape of the toroidal plasma current density profile we discuss the stability of highly shifted equilibria and their robustness to current profile variations that could occur in actual experiments. The evolution of the plasma parameters, as the beta poloidal is increased, is also examined to give a better understanding of the difference in performance between the various regimes.
Field effect white and tunable electroluminescence from ion beam synthesized Si- and C-rich SiO2 layers
Authors: Jambois O. , Carreras Josep , Pérez-Rodríguez A. , Garrido B. , Bonafos C. , Schamm S. , Assayag G. Ben
Published: November 2007

White and tunable electroluminescence has been obtained by field effect injection in 40nm thick Si- and C-rich SiO2 layers. The films, synthesized by ion implantation, contain Si and C-rich nanoparticles embedded in SiO2 which were formed by annealing at 1100°C. Shifting of the distribution of C-related centers toward the interface region with the substrate allows us to obtain a characteristic white electroluminescence emission under pulsed excitation conditions. Moreover, an evolution of the emission spectrum from white to red is observed by changing the frequency of the pulse. A power efficiency higher than 10−3% is estimated. This work opens interesting perspectives on color tunability of field effect electroluminescent devices.
Steady-state and transient photocurrents in rubrene single crystal free-space dielectric transistors
Authors: Mathews N. , Fichou D. , Menard E. , Podzorov V. , Mhaisalkar S. G.
Published: November 2007

We report results of photocurrent studies performed on rubrene single crystal transistors in the air-gap configuration under 405nm irradiation. The phototransistors show a strong photoresponse indicative of photoconduction. Under illumination, the phototransistors show an average threshold voltage shift of 22V and a maximum photosensistivity of 2.65×103. A small persistent photoconductivity effect is observed in the transistors tested under continuous illumination which is explained by delayed recombination aided by spatial separation of the photocarriers. Photocurrent transients measured by applying short pulses on the other hand show a complete recovery in the microsecond regime implying immediate recombination.
On generation of dark solitons by gravitational waves in a strongly magnetized pulsar plasma
Authors: Mofiz U. A.
Published: November 2007

In this paper, the propagation of gravitational wave perpendicular to a superstrong magnetic field immersed in an electron-positron pulsar plasma is considered. On the basis of the Einstein–Maxwell system of magnetohydrodynamic equations, both the linear and nonlinear interactions of the wave with plasma are investigated. In near-resonant interaction, a relation between gravitation perturbations to electromagnetic field perturbations shows that the field perturbations are directly proportional to the product of ambient magnetic field and the gravitational wave perturbation. Thus, a weak gravitational wave may resonate an effective field perturbation in the strongly magnetized plasma in an astrophysical context. A coupled system of equations describing the nonlinear interaction between gravitational wave and field perturbations in the magnetized plasma is obtained. The equations are solved in resonant approximation, and it is found that a linearly polarized electric field is generated with a frequency close to the plasma frequency. For nonresonant interaction, the solution shows that both electric and magnetic field perturbations in the plasma are produced. Density perturbation and field intensity variation in the plasma lead to a nonlinear frequency shift and the slowly varying field amplitude obeys the nonlinear Schrödinger equation. The solution of the equation is the dark soliton, the amplitude of which may be very significant in the case of a superstrong magnetic field in the pulsar plasma.
Simplified small-scale backlight unit tester
Authors: Tsai Ruei-Hung , Su Fang-Hsuan , Chen Jui-Pin , Tsay Ho-Lin , Wen Jen-Yu , Wei Tzu-Hsuan , Huang Ting-Ming , Liao Tai-Shan
Published: November 2007

A novel design is the concept of using charge coupled device camera embedded with calibrated image processing algorithm as a two-dimensional luminance meter to measure the luminance and uniformity of small-scale backlight of unit. A small-scale backlight unit tester was successfully realized and performed to verify this concept.
Stability analysis of a class of unsteady nonparallel incompressible flows via separation of variables
Authors: Burde Georgy I. , Nasibullayev Ildar Sh. , Zhalij Alexander
Published: November 2007

Stability of some unsteady three-dimensional flows (exact solutions of the viscous incompressible Navier–Stokes equations in cylindrical coordinates) is studied via separation of variables in the linearized equations for the flow perturbations. The flows in an expanding rotating porous cylinder and in a gap between two coaxial rotating cylinders are considered. Converting the stability equations to the new variables allows perturbation forms (counterparts of normal modes of the steady state parallel flow stability problem) such that the linear stability problems are exactly reduced to eigenvalue problems of ordinary differential equations. The eigenvalue problems are solved numerically with the help of the spectral collocation method based on Chebyshev polynomials. The results showing dependence of the stability threshold on the parameters of the problems and a spatial structure of the unstable perturbation modes are presented. For some classes of perturbations, exact analytical solutions of the eigenvalue problems are available. A combination of analytical and numerical solutions can provide useful testing for numerical methods used in the hydrodynamic stability studies. It may also provide a basis for a well-grounded discussion of some problematic points of (numerical) stability analysis. In particular, in the present paper, a problem of formulation of the boundary conditions for perturbations at the axis r=0 is discussed on the basis of the solutions obtained.
Iodine enhanced focused-ion-beam etching of silicon for photonic applications
Authors: Schrauwen Jonathan , Van Thourhout Dries , Baets Roel
Published: November 2007

Focused-ion-beam etching of silicon enables fast and versatile fabrication of micro- and nanophotonic devices. However, large optical losses due to crystal damage and ion implantation make the devices impractical when the optical mode is confined near the etched region. These losses are shown to be reduced by the local implantation and etching of silicon waveguides with iodine gas enhancement, followed by baking at 300 °C. The excess optical loss in the silicon waveguides drops from 3500 to 1700 dB/cm when iodine gas is used, and is further reduced to 200 dB/cm after baking at 300 °C. We present elemental and chemical surface analyses supporting that this is caused by the desorption of iodine from the silicon surface. Finally we present a model to extract the absorption coefficient from the measurements.
Negative permeability of magnetic nanocomposite films for designing left-handed metamaterials
Authors: Mitsumata Chiharu , Tomita Satoshi
Published: November 2007

We have theoretically evaluated magnetic permeability of Ni nanocomposite films, in which the dipolar interactions between the Ni particles are considered explicitly. A numerical model of the nanocomposite is constructed according to our recent experimental results and a micromagnetic calculation is conducted. We show that the value of permeability strongly depends on the volume fraction and randomness of the particles. Particularly, as the randomness of the particles increases, the negative value of permeability drastically shrinks. However, the region of applied field, where the permeability is negative, becomes broader. This is advantageous for the broadband left-handed metamaterials in microwave regions.
Role of Brownian motion on the thermal conductivity enhancement of nanofluids
Authors: Gupta Amit , Kumar Ranganathan
Published: November 2007

This study involves Brownian dynamics simulations of a real nanofluid system in which the interparticle potential is determined based on Debye length and surface interaction of the fluid and the solid. This paper shows that Brownian motion can increase the thermal conductivity of the nanofluid by 6% primarily due to “random walk” motion and not only through diffusion. This increase is limited by the maximum concentration for each particle size and is below that predicted by the effective medium theory. Beyond the maximum limit, particle aggregates begin to form. Brownian motion contribution stays as a constant beyond a certain particle diameter.
Cation ordering/disordering kinetics in Ba3CoNb2O9: Anin situstudy using synchrotron x-ray powder diffraction
Authors: Mallinson P. M. , Claridge J. B. , Rosseinsky M. J. , Ibberson R. M. , Wright J. P. , Fitch A. N. , Price T. , Iddles D. M.
Published: November 2007

In situ synchrotron x-ray powder diffraction has been used to study the kinetics of cation ordering and disordering in the microwave dielectric electroceramic Ba3CoNb2O9 with a time resolution of 15s. The method enables the order/disorder temperature (To∕d) in this material of 1430°C to be directly observed. The changes in the rate and degree of cation ordering and in the growth of ordered domains between samples ordered from standard precursor material and then subsequently reordered following an annealing period above To∕d show that small changes in precursor order state and phase assemblage strongly influence the final domain size.
Hole-mediated electric field tunable high Curie temperature in Mn-doped wurtzite ZnO nanowires
Authors: Zhang Xiu-Wen , Fan Wei-Jun , Li Shu-Shen , Xia Jian-Bai
Published: November 2007

The hole-mediated Curie temperature in Mn-doped wurtzite ZnO nanowires is investigated using the k∙p method and mean field model. The Curie temperature TC as a function of the hole density has many peaks for small Mn concentration (xeff) due to the density of states of one-dimensional quantum wires. The peaks of TC are merged by the carriers’ thermal distribution when xeff is large. High Curie temperature TC>400K is found in (Zn,Mn)O nanowires. A transverse electric field changes the Curie temperature a lot. (Zn,Mn)O nanowires can be tuned from ferromagnetic to paramagnetic by a transverse electric field at room temperature.
“Which Feels Heavier—A Pound of Lead or a Pound of Feathers?” A Potential Perceptual Basis of a Cognitive Riddle
Authors: Wagman Jeffrey B , Zimmerman Corinne , Sorric Christopher
Published: November 2007

“Which weighs more—a pound of lead or a pound of feathers?” The seemingly naive answer to the familiar riddle is the pound of lead. The correct answer, of course, is that they weigh the same amount. We investigated whether the naive answer to the riddle might have a basis in perception. When blindfolded participants hefted a pound of lead and a pound of feathers each contained in boxes of identical size, shape, and mass, they reported that the box containing the pound of lead felt heavier at a level above chance. Like the size—weight illusion, the naive answer to the riddle may reflect differences in how easily the objects can be controlled by muscular forces and not a perceptual or cognitive error.
Application of n-alkanes as diet composition markers in grazing/browsing goats and sheep: effect of using different faecal recovery corrections and plant species grouping approaches
Authors: Oliván M. , Ferreira L. M. M. , García U. , Celaya R. , Osoro K.
Published: November 2007

The present study aimed to test the effect of applying different sets of n-alkane faecal recoveries and different plant species grouping approaches on the estimates of the diet selected by goats and sheep when grazing/browsing complex vegetation communities composed of mosaics of heather-gorse vegetation interspersed with patches of perennial ryegrass. The use of different sets of n-alkane faecal recoveries significantly affected the estimated proportions of most vegetation components in both animal species. The diet estimates were also significantly affected by the calculation approach: A1 (using all individual plant species); A2 (grouping plant species with similar n-alkane profile, with equal weighting within the group); and A3 (grouping plant species with similar n-alkane profile, with different weighting according to the botanical composition of the plot). There was a significant interaction between calculation approach (A) and faecal recovery sets (FR) on the resulting estimates of the Ericaceae species in the diet of goats and of all diet components in sheep. When using A1 approach, the estimated proportion of Agrostis capillaris in the diets was high and seemed to be overestimated, compared with its low availability (1.1% of total cover) in the field. However, the application of calculation approaches A2 and A3 gave lower dietary proportions of component D2 (Agrostis capillaris and Ulex gallii) and higher proportions of components D1 (Lolium perenne and Pseudarrhenatherum longifolium), D3 (Erica umbellata, Erica cinerea, Erica australis, Calluna vulgaris) and Erica arborea. These results indicate that the application of the n-alkane technique for estimation of the diet composition in field with complex vegetation conditions is sensitive to the use of faecal recovery corrections and to the grouping of possible dietary components.
Canopy development and hydraulic function in Eucalyptus tereticornis grown in drought in CO2-enriched atmospheres
Authors: Atwell Brian J. , Henery Martin L. , Rogers Gordon S. , Seneweera Saman P. , Treadwell Marie , Conroy Jann P.
Published: November 2007

We report on the relationship between growth, partitioning of shoot biomass and hydraulic development of Eucalyptus tereticornis Sm. grown in glasshouses for six months. Close coordination of stem vascular capacity and shoot architecture is vital for survival of eucalypts, especially as developing trees are increasingly subjected to spasmodic droughts and rising atmospheric CO2 levels. Trees were exposed to constant soil moisture deficits in 45 L pots (30–50% below field capacity), while atmospheric CO2 was raised to 700 μL CO2 L–1 in matched glasshouses using a hierarchical, multi-factorial design. Enrichment with CO2 stimulated shoot growth rates for 12–15 weeks in well-watered trees but after six months of CO2 enrichment, shoot biomasses were not significantly heavier (30% stimulation) in ambient conditions. By contrast, constant drought arrested shoot growth after 20 weeks under ambient conditions, whereas elevated CO2 sustained growth in drought and ultimately doubled the shoot biomass relative to ambient conditions. These growth responses were achieved through an enhancement of lateral branching up to 8-fold due to CO2 enrichment. In spite of larger transpiring canopies, CO2 enrichment also improved the daytime water status of leaves of droughted trees. Stem xylem development was highly regulated, with vessels per unit area and cross sectional area of xylem vessels in stems correlated inversely across all treatments. Furthermore, vessel numbers related to the numbers of leaves on lateral branches, broadly supporting predictions arising from Pipe Model Theory that the area of conducting tissue should correlate with leaf area. Diminished water use of trees in drought coincided with a population of narrower xylem vessels, constraining hydraulic capacity of stems. Commensurate with the positive effects of elevated CO2 on growth, development and leaf water relations of droughted trees, the capacity for long-distance water transport also increased.
Oxidative stress does not influence carotenoid mobilization and plumage pigmentation
Authors: Isaksson Caroline , Andersson Staffan
Published: November 2007

Oxidative stress has been suggested to create a link between ‘good genes’ and carotenoid coloration via an allocation conflict between external pigmentation and internal antioxidant functions. However, although carotenoid displays have been extensively investigated, there are no experimental tests of the antioxidant efficiency of carotenoidsin vivo.We induced oxidative stress in a small passerine (the great tit,Parus major) under both carotenoid deprivation and supplementation, and investigated the effect on carotenoid mobilization (i.e. plasma) and allocation (i.e. deposition in feather incorporation and liver storage). We found no effects of the stressor on either mobilization or allocation of carotenoids. These results reject the previously suggested superior role of carotenoid's function as antioxidantin vivowith important implications for signal content and honesty.
Nurses and Internet health information: a questionnaire survey
Authors: Gilmour Jean A. , Scott Susan D. , Huntington Nicholas
Published: November 2007

Title.  Nurses and Internet health information: a questionnaire survey

Aim.  This paper is a report of a study to identify the extent of postgraduate nursing students’ information literacy skills in relation to electronic media and health information and barriers to accessing this information.

Background.  The Internet is a key source of information for a significant group of patients. However, there is evidence of quality issues with some Internet health information sites. Nurses need to be aware of the range and quality of online health information so as to assist patients and families to locate and evaluate relevant and current information.

Method.  A questionnaire designed to collect quantitative and qualitative data was posted to a convenience sample of all students enrolled in a postgraduate nursing programme in December 2005. The response rate was 55·1% or 123 responses.

Results.  Most respondents had Internet access at home and work and believed that access to online health information resources had improved their practice. However, some had difficulties in accessing computers at work and insufficient time to search for online health information. Concern was expressed about the quality of online information, but the majority of respondents did not assess patient use. Frequent users of online resources were more likely to assess patient use.

Conclusion.  The development of nursing competencies in accessing and using online resources is a key precursor to supporting patients and families’ use of the medium. Access to Internet resources at work, along with training and time for searching, is necessary for the development of skills enabling effective use of information technology.
A resource‐based perspective on retention strategies for nurse epidemiologists
Authors: Tsai Ming‐Tien , Ya‐Ti Hsu
Published: November 2007

Title.  A resource‐based perspective on retention strategies for nurse epidemiologists

Aim.  This paper is a report of a study to evaluate the intent of epidemiologists to remain in their chosen career and identify the variables that contributed to or predicted their intent to stay.

Background.  Recently, emerging new infections, such as severe acute respiratory syndrome or bird flu, have placed significant occupational and psychological stress on epidemiologists, especially in South‐East Asia, resulting in a high intent to change their career. In the light of possible staff shortages, retention strategies for epidemiologists have gained importance.

Methods.  A self‐administered questionnaire survey and stratified sampling were used to collect data from 351 epidemiologists including nurse epidemiologists in Taiwan in 2005; response rate was 70·6%. Correlation analysis and hierarchical multiple regression analysis were used to examine relationships among occupational stress, psychological stress, human resources and intent to stay in their career.

Results.  Occupational stress, psychological stress and human resources had an impact on epidemiologists’ intent to stay in their career. Results show that the relationship between occupational stress (operation and personal safety hazard) and intent to stay could be influenced by organizational capital, and the relationship between emotional distress and intent to stay could be influenced by a broad spectrum of human resources (organizational, social and human capital).

Conclusion.  The severe acute respiratory syndrome epidemic raised worldwide attention and challenged epidemiologists’ intent to stay. Results indicate that human resources play an important role in this issue. Managers should enhance human resources in organizations as much as possible to attenuate epidemiologists’ stress, which may, in turn, strengthen their intent to stay.
How reliable is the current evidence looking at the efficacy of harm reduction and motivational interviewing interventions in the treatment of patients with a dual diagnosis?
Authors: LAKER C. J.
Published: November 2007

Current policy from the Department of Health advocates for an integrated approach to treating patients with a dual diagnosis. However, pragmatic and clinically effective brief interventions that can be delivered by nurses across mental health settings remain underdeveloped. Motivational interviewing has had some successful exposure in the field of dual diagnosis; however, harm reduction remains unexplored both conceptually and in terms of clinical intervention. This literature review examines the notion of harm reduction as a method of identifying and reducing the harm associated with the misuse of drugs and alcohol in relation to mental health problems. Currently there is a paucity of good quality evidence for integrated interventions in the treatment of dually diagnosed patients. Therefore, the papers are analysed in respect of their methodological quality and contribution to the evidence base to inform both future research and mental health nursing practice.
Lifeworld, the arts and mental health nursing
Authors: BILEY F. C. , GALVIN K. T.
Published: November 2007

Various manifestations of the arts have been employed in mental health care as successful diversional and therapeutic interventions, and as an adjunct to mental healthcare professional education. There is now a current groundswell of the use of the arts and humanities in both the practice of research and the representation and dissemination of findings. Here, we first point to the potential ability of the arts that can be used to re‐humanize the world of health and social care and its underpinning sciences. Second, we highlight the nature and relevance of this more aesthetic movement and its potential to enable meaningful engagement with people in order to facilitate shared understandings of concretely lived experiences. Finally, we use a long‐standing philosophical framework, the ‘lifeworld’, as an exemplar to demonstrate how the wholeness and essence of human being can be revealed or shown through art. In doing so, we make the tentative suggestion that phenomenology and the lifeworld approach may be a useful philosophical framework for underpinning the use of arts in mental health nursing.
The trade‐off between vegetative and generative reproduction among angiosperms influences regional hydrochorous propagule pressure
Authors: Boedeltje Ger , Ozinga Wim A. , Prinzing Andreas
Published: November 2007

Aim Local communities are subject to spatiotemporal contingencies of landscape processes; community assembly is thus often considered to be unpredictable and idiosyncratic. However, evolved trade‐offs of species’ life histories may set distinct constraints on the assembly of species communities. In plants, the recruitment and invasion success of species into communities depend primarily on the number of propagules available and on their generative or vegetative character. Life‐history trade‐offs prevent individual plants from producing large numbers of both generative and vegetative propagules, but it is not clear whether this constrains their availability at the landscape scale. We thus tested whether: (1) the observed relationship between generative and vegetative propagules deviates from the null expectation stating that species contributing the bulk of generative propagules to the propagule rain should also contribute the bulk of vegetative propagules; and (2) whether vegetative and generative propagule pressures are negatively correlated once species abundance in the regional pool is accounted for.

Location A large riparian landscape in the Netherlands.

Methods Analyses were based on an extensive trapping of floating propagules (214,049 propagules of 47 species), and a rough proxy of species abundance across the entire pool. We used both species and phylogenetically independent contrasts as data points, and accounted for variation in size of generative propagules.

Results Both hypotheses were confirmed. Numbers of generative and vegetative propagules trapped per species were significantly negatively correlated (r = −0.33;t45 = −2.61,P = 0.006) and thus strongly deviated from the null expectation. This was confirmed by analyses accounting for variation in species abundance across the species pool, and in the size of generative propagules.

Main conclusions The results indicate that plant recruitment and community assembly across streams may be influenced by the way individual plants allocate their resources between competing life‐history functions. Life‐history evolution across angiosperms might thus have constrained the present‐day assembly of local communities.
What do measures of ‘oral health‐related quality of life’ measure?
Authors: Locker David , Allen Finbarr
Published: November 2007

The terms ‘health‐related quality of life’ and ‘quality of life’ are now in common use to describe the outcomes of oral health conditions and therapy for those conditions. In addition, there has been a proliferation of measures designed to quantify those outcomes. These measures, which were initially designated as socio‐dental indicators or subjective oral health indicators are now more usually referred to as measures of oral health‐related quality of life (OH‐QoL). This is based on the assumption that the functional and psychosocial impacts they document must, of necessity, affect the quality of life. While this assumption has been subject to critical scrutiny in medicine, this is not the case with dentistry. Consequently, exactly what is being measured by indexes of OH‐QoL is somewhat unclear. Based on the debate between Gill and Feinstein and Guyatt and Cook, we outline a number of criteria by means of which the construct addressed by measures of OH‐QoL may be assessed. These are concerned with how the measures were developed and validated. These criteria are then used to appraise five of the many measures that have been developed over the past 20 years – the GOHAI, OHIP, OIDP, COHQoL and OH‐QoL. The main conclusion is that while all document the frequency of the functional and psychosocial impacts that emanate from oral disorders they do not unequivocally establish the meaning and significance of those impacts. Consequently, the claim that oral disorders affect the quality of life has yet to be clearly demonstrated. Verifying this claim requires further qualitative studies of the outcomes of oral disorders as perceived by patients and persons, and the concurrent use of measures that more explicitly address the issue of quality of life.
Studies on the Stellaria longipes complex (Caryophyllaceae). VII. The seed proteins
Authors: Gifford David J. , Chinnappa C. C.
Published: November 2007

Seed proteins of Stellaria longipes s.l. 2n = 52, 78, and 104, have been characterized using sodium dodecyl sulphate – polyacrylamide gel electrophoresis. The same general pattern as regards the number of major protein components resolved was observed in all the genotypes and cytotypes studied. These included all the morphotypes that were described as distinct species. The present data do not contradict the conclusions drawn from cytogenetic studies that all the morphological types are closely related and are part of a polyploid species complex.
Assessing the diversity and composition of restored vegetation
Authors: Pielou E. C.
Published: November 2007

When surface-mined land is revegetated, the original vegetation should be restored in its full diversity. No quick, simple method exists for comparing the diversities of "old" and "new" plant communities. Current methods are laborious since they entail estimating diversity indices and their sampling variances. This paper gives a method for comparing the diversities of two communities directly, without estimating their diversity indices. It uses the fact that if one samples a community by listing the species at each of several sampling points, then, if community diversity is low, the several species lists will resemble one another closely, whereas if it is high, the lists will vary markedly among themselves. To compare diversities, one compares the pairwise resemblances between species lists within each community. If two communities are equally diverse, one wishes to know whether they have the same proportional species composition. If their diversities differ, one wishes to know whether the less diverse community is merely a subset of the more diverse. The data used for comparing diversities can be used to answer these questions also. Three examples illustrate application of the tests in comparing the vegetation on mined and restored land.
The supposed fern Onychiopsis psilotoides from the English Wealden (Lower Cretaceous) reinterpreted as a lycopod
Authors: Skog Judith E.
Published: November 2007

Specimens that had been previously considered to represent a fertile fern, Onychiopsis psilotoides (Stokes et Webb) Ward from the English Wealden, have been restudied and are here considered to represent a new genus (Tanydorus) in a new family within the Lycopodiales. Evidence for this new classification of the material includes the combination of a spiral (helical) arrangement of the leaves, presence of an elongated sporangium in the axil of a sporophyll, distinct strobilus borne on the sterile basal portions, and structure of the numerous homosporous spores. The combination of elongated sporangia and details of spore ultrastructure preclude placement in the only family currently assigned to this order, the Lycopodiaceae.
Histochemical evidence for the presence of a suberinlike compound in Rhizobium-induced nodules of the nonlegume Parasponia rigida
Authors: Smith Carol A. , Skvirsky Rachel C. , Hirsch Ann M.
Published: November 2007

Parasponia rigida (Ulmaceae) nodules, like nodules of pea and alfalfa, are elongate and cylindrical and of indeterminate morphology. However, unlike other indeterminate nodules, the Rhizobium (Rp501) endosymbiont is not released into the host cell cytoplasm and remains confined to threads. Two types of threads are found: invasive infection threads that traverse the nodule tissue intracellularly and intercellularly; and threads confined to the nodule cell, proliferating intracellularly, which are the presumed sites of nitrogen fixation. The thread walls contain pectic and cellulosic components as evidenced by periodic acid – Schiff’s staining and digestion with pectinase and cellulase. Using histochemical analyses coupled with enzymatic and chemical extraction, we determined that the walls of the intracellularly confined threads also contain a suberinlike compound. The thread walls stain positively with Sudan black B and other lipid stains. In contrast, the invasive infection threads appear to be lignified as well as suberized.
Conidial states of some species of Diatrypaceae and Xylariaceae
Authors: Glawe Dean A. , Rogers Jack D.
Published: November 2007

Anamorphs of Cryptosphaeria vicinula, Eutypella angulosa, Eutypa spinosa, Hypoxylon microplacum, and Graphostroma platystoma are described and illustrated. Percurrent proliferation of conidiogenous cells is reported in H. microplacum, the first association of this kind of proliferation with Hypoxylon. Taxonomic and phylogenetic implications of these findings are discussed.
Growth and reproduction of the red alga Rhodomela larix
Authors: D'Antonio Carla
Published: November 2007

Components of the growth and life history of the red alga Rhodomela larix (Turner) C. Agardh were studied during an 18-month period at a high intertidal and a low intertidal site on the central Oregon coast. Growth was measured by following (i) individually marked upright axes, (ii) clumps of axes thought to represent individual plants, and (iii) large patches of R. larix. Variation in size and growth was common among axes, and portions of some axes were clearly perennial. Plants grew most rapidly in the spring and summer (up to 1.2 mm/day) with a large amount of variation occurring between and within zones and among seasons. Overall, plants at the higher site were shorter and had fewer branches during most of the year than plants at the lower site. Gametophytes were more common in the higher site, while tetrasporophytes predominated at both sites. Reproductive axes were present throughout the observation period, although little recruitment of sexual propagules was seen, implying that populations may be maintained by vegetative perennation of individual plants.
Two new species of Phialocephala occurring on Picea and Alnus
Authors: Kowalski Tadeusz , Kehr Rolf D.
Published: November 2007

Two new species of Phialocephala were isolated from the periderm of living branches of forest trees in Germany. In culture, Phialocephala compacta Kowalski & Kehr sp.nov., found on Alnus, is characterized by crowded conidiogenous heads that become deeply pigmented with age. Phialocephala scopiformis Kowalski & Kehr sp.nov., isolated from Picea and other conifers, develops elongated, complex conidiogenous heads with up to 15 series of branches in culture. The taxonomic placement of both new species and their role in endophytism and in natural pruning of branches is discussed. Key words: Picea abies, Alnus glutinosa, Phialocephala compacta, Phialocephala scopiformis, branch pruning fungi.
Sublethal effects of the insecticide fenitrothion on freshwater phytopiankton
Authors: Kent Robert A. , Caux Pierre-Yves
Published: November 2007

The effects of the insecticide fenitrothion (O,O-dimethyl-O-(3-methyl-4-nitrophenyl)phosphorothioate) were investigated on the unicellular phytoplankton Ankistrodesmus falcatus, Chlamydomonas reinhardtii, Chlamydomonas segnis, Chlorella pyrenoidosa, Navicula sp., Scenedesmus obliquus, Selenastrum capricornutum, and Staurastrum sp. at concentrations of 0.1, 1.0, and 10 mg∙L−1. Following a 24-h exposure, total lipids, fatty acid profiles, and bioaccumulation of fenitrothion into algal cells were determined for the above species. Total lipids may play an important role in determining sensitivity of phytoplankton to fenitrothion stress over 96-h exposures. A saturation occurred in A. falcatus membranes represented by the 5.4 and 4.3% increases in palmitic (16:0) and oleic (18:1) acids, respectively, and 1.8 and 7.6% decreases in linoleic (18:2) and linolenic (18:3) acids, respectively. This resulted in a shift from a profile dominated by linolenic (18:3) acid to one dominated by the more saturated oleic (18:1) acid. Bioconcentration factors (BCF), or the ratio of the total radiocarbon associated with algae, calculated for viable Chlamydomonas reinhardtii and Chlamydomonas segnis cells were 293 and 124, respectively. BCFs for dead cells were 1261 and 1025 for the same species, respectively. These investigations showed differential insecticide bioaccumulation between species. This bioaccumulation was shown to be correlated with the total lipid content of algal cells. Key words: algae, fatty acids, fenitrothion, lipids, pesticide.
A new coprophilous species of Podosordaria from Venezuela
Authors: Krug J. C. , Jeng R. S.
Published: November 2007

Podosordaria venezuelensis (Ascomycotina, Xylariaceae) is described and illustrated. It is characterized by the long-stalked, glabrous stromata, ascospore shape and size, and germ slit length, differing from morphologically similar taxa in spore morphology and distribution. A key to all currently accepted species of this fungal genus is provided. Key words: Podosordaria, Xylariaceae, coprophilous, taxonomy, Venezuela.
The influence of fire onSpartina pectinatawetland communities in a northeastern Kansas tallgrass prairie
Authors: Johnson Stephen R. , Knapp Alan K.
Published: November 2007

Wetlands dominated by the C4grass Spartina pectinata were investigated to quantify differences in plant species composition and diversity in response to fire frequency. The study site was a tallgrass prairie in northeastern Kansas that included Spartina wetlands subjected to spring fires at 1-, 2-, 4-, 10-, and 20-year intervals. Because C3forbs in these wetlands responded strongly to different fire frequencies, the light environment and gas exchange responses of the ubiquitous forb Asclepias syriaca were also assessed. In general, species diversity was lower in annually burned wetlands because of lower forb diversity. Maximum H′ in annually burned sites was 1.64 versus 2.77 in 10- and 20-year burned sites. However, individual forb responses varied. Asclepias increased and Solidago canadensis and Galium aparine decreased in importance with increasing fire frequency. Canopy sunlight interception was greater in annually burned wetlands than in wetlands with lower burn frequencies. Despite reduced light availability, midseason photosynthetic rates of Asclepias were higher in annually burned sites. The results suggest that frequent fire in tallgrass prairie wetlands results in less diverse plant communities, similar to responses of upland prairie, and that the timing of fire, relative to life history and phenology of the subordinate species, strongly influences responses of individual forbs. Key words: wetlands, tallgrass prairie, Spartina pectinata communities, fire.