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Selected AbstractsBursaphelenchus species in conifers in Europe: distribution and morphological relationshipsEPPO BULLETIN, Issue 2 2001H. Braasch The morphological relationship between European Bursaphelenchus species living in conifers was studied in order to provide key characters for their taxonomic identification. Several species have been newly described or recorded in Europe during the past few years and were morphologically investigated. Among the 28 conifer-inhabiting European species, four groups can be distinguished from each other by the number of lateral incisures, number and position of anal papillae of males and presence and size of a vulval flap of females. Two groups, each containing just one species show two and six lateral lines, respectively, whereas most Bursaphelenchus species belong to two groups, possessing either three or four incisures. Each of the last two groups can be divided into three subgroups, which can be differentiated by spicule shape, number and position of caudal papillae, presence and size of a vulval flap and some other features. A fifth group includes species with unclear group affiliation due to insufficient knowledge of their morphology. The B. xylophilus group (B. xylophilus, B. mucronatus, B. fraudulentus) with four lateral lines, unique spicule shape and characteristic position of the caudal papillae can clearly be differentiated from all other groups by morphology, also using only light microscopy. Within this group, B. xylophilus can clearly be differentiated morphologically from the other species, provided that adult specimens of both sexes are found and also provided that the round-tailed form of the species remains the only form present, as in Europe. Figures showing the important identification features of spicule shape and female tail shape are given for 28 species. A table shows the complete range of the most important morphometric measurements of these species. Data on the occurrence, host range and, as far as known, the vectors of these species were collected throughout Europe and references are given for each record. [source] Somatic and visceral afferents to the ,vasodepressor region' of the caudal midline medulla in the ratEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2003Jason R. Potas Abstract Previous research has found that the integrity of a restricted region of the caudal midline medulla (including caudal portions of nucleus raphé obscurus and nucleus raphé pallidus) was critical for vasodepression (hypotension, bradycardia, decreased cardiac contractility) evoked either by haemorrhage or deep pain. In this anatomical tracing study we found that the vasodepressor part of the caudal midline medulla (CMM) receives inputs arising from spinal cord, spinal trigeminal nucleus (SpV) and nucleus of the solitary tract (NTS). Specifically: (i) a spinal,CMM projection arises from neurons of the deep dorsal horn, medial ventral horn and lamina X at all spinal segmental levels, with approximately 60% of the projection originating from the upper cervical spinal cord (C1,C4); (ii) a SpV,CMM projection arises primarily from neurons at the transition between subnucleus caudalis and subnucleus interpolaris; (iii) a NTS,CMM projection arises primarily from neurons in ventrolateral and medial subnuclei. In combination, the specific spinal, SpV and NTS regions which project to the CMM receive the complete range of somatic and visceral afferents known to trigger vasodepression. The role(s) of each specific projection is discussed. [source] On the Ekberg, Kabo and Andersson calculation of the Dang Van high cycle fatigue limit for rolling contact fatigueFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 6 2004M. CIAVARELLA ABSTRACT Recently, various methods have been proposed to assess the risk of rolling contact fatigue failure by Ekberg, Kabo and Andersson, and in particular, the Dang Van multiaxial fatigue criterion has been suggested in a simple approximate formulation. In this note, it is found that the approximation implied can be very significant; the calculation is improved and corrected, and focused on the study of plane problems but for a complete range of possible friction coefficients. It is found that predicted fatigue limit could be much higher than that under standard uniaxial tension/compression for ,hard materials' than for ,ductile materials.' This is in qualitative agreement, for example, with gears' design standards, but in quantitative terms, particularly for frictionless condition, the predicted limit seems possibly too high, indicating the need for careful comparison with experimental results. Some comments are devoted to the interplay of shakedown and fatigue. [source] Implementation of the symmetric doped double-gate MOSFET model in Verilog-A for circuit simulationINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 2 2010Joaquín Alvarado Abstract Recently we developed a model for symmetric double-gate MOSFETs (SDDGM) that, for the first time, considers the doping concentration in the Si film in the complete range from 1×1014 to 3×1018,cm,3. The model covers a wide range of technological parameters and includes short channel effects. It was validated for different devices using data from simulations, as well as measured in real devices. In this paper, we present the implementation in Verilog-A code of this model, which allows its introduction in commercial simulators. The Verilog-A implementation was optimized to achieve reduction in computational time, as well as good accuracy. Results are compared with data from 2D simulations, showing a very good agreement in all transistor operation regions. Copyright © 2009 John Wiley & Sons, Ltd. [source] Distinguishing between task and contextual performance for nurses: development of a job performance scaleJOURNAL OF ADVANCED NURSING, Issue 6 2007Jaimi H. Greenslade Abstract Title.,Distinguishing between task and contextual performance for nurses: development of a job performance scale Aim., This paper is a report of a development and validation of a new job performance scale based on an established job performance model. Background., Previous measures of nursing quality are atheoretical and fail to incorporate the complete range of behaviours performed. Thus, an up-to-date measure of job performance is required for assessing nursing quality. Methods., Test construction involved systematic generation of test items using focus groups, a literature review, and an expert review of test items. A pilot study was conducted to determine the multidimensional nature of the taxonomy and its psychometric properties. All data were collected in 2005. Findings., The final version of the nursing performance taxonomy included 41 behaviours across eight dimensions of job performance. Results from preliminary psychometric investigations suggest that the nursing performance scale has good internal consistency, good convergent validity and good criterion validity. Conclusion., The findings give preliminary support for a new job performance scale as a reliable and valid tool for assessing nursing quality. However, further research using a larger sample and nurses from a broader geographical region is required to cross-validate the measure. This scale may be used to guide hospital managers regarding the quality of nursing care within units and to guide future research in the area. [source] Thermodynamic Properties and Phase Diagram for the System MoO2,TiO2JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2008K. Thomas Jacob The activity of molybdenum dioxide (MoO2) in the MoO2,TiO2 solid solutions was measured at 1600 K using a solid-state cell incorporating yttria-doped thoria as the electrolyte. For two compositions, the emf was also measured as a function of temperature. The cell was designed such that the emf is directly related to the activity of MoO2 in the solid solution. The results show monotonic variation of activity with composition, suggesting a complete range of solid solutions between the end members and the occurrence of MoO2 with a tetragonal structure at 1600 K. A large positive deviation from Raoult's law was found. Excess Gibbs energy of mixing is an asymmetric function of composition and can be represented by the subregular solution model of Hardy as follows The temperature dependence of the emf for two compositions is reasonably consistent with ideal entropy of mixing. A miscibility gap is indicated at a lower temperature with the critical point characterized by Tc (K)=1560 and. Recent studies indicate that MoO2 undergoes a transition from a monoclinic to tetragonal structure at 1533 K with a transition entropy of 9.91 J·(mol·K),1. The solid solubility of TiO2 with rutile structure in MoO2 with a monoclinic structure is negligible. These features give rise to a eutectoid reaction at 1412 K. The topology of the computed phase diagram differs significantly from that suggested by Pejryd. [source] Simulations of instability in fiber spinning of polymersPOLYMER ENGINEERING & SCIENCE, Issue 7 2010Atanas Gagov This work determines the critical regimes beyond which the melt fiber spinning for noncrystallizable polymeric liquids becomes unstable. The critical draw ratio of the process is established using linear stability analysis for both isothermal and nonisothermal fiber spinning regimes. In addition, nonlinear isothermal analysis describes the complete range of the stable and unstable conditions for fiber spinning. Unlike previous studies, this research uses quite realistic viscoelastic constitutive equations extensively tested for five polymer liquids, which provides a good comparison of our calculations with available experimental data. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers [source] Time-cure-temperature superposition for the prediction of instantaneous viscoelastic properties during curePOLYMER ENGINEERING & SCIENCE, Issue 6 2000Yongsung Eom The relative sequence of shrinkage and evolution of modulus of a thermoset resin during cure leads to the build-up of internal stresses, especially if the resin is constrained by the presence of other materials in the form of a substrate or reinforcing fibers. To enable prediction of the levels of internal stress generated during processing and to determine appropriate processing windows, the evolution of the modulus of an epoxy-amine system during cure has been characterized and described with a phenomenological model. A combined reaction kinetics model is used to determine the degree of conversion of the epoxy over any complete range of cure. The chemorheological properties of the resin are measured as a function of curing temperature with a torsional parallel plate rheometer. A new phenomenological approach for time-cure-temperature superposition is proposed for predicting the relaxation modulus at any moment during cure and at any cure temperature. The combination of these two models provides a full description of the instantaneous viscoelastic properties during cure. This approach, which can be adapted to any curing resin, provides suitable tools for the analysis of viscoelastic stress build-up following any industrially relevant cure cycle. [source] Habitat indices for rivers: derivation and applicationsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010Ian P. Vaughan Abstract 1.River Habitat Survey (RHS) is the standard riverine hydromorphology survey in the UK and modified versions have been adopted in several other European Countries. It aims to broadly characterize physical features over 500,m reaches, but in so doing records more than 100 variables, often making interpretation and data analysis challenging. In such instances, synoptic treatment of the data, creating simple indices such as Habitat Modification and Habitat Quality Assessment scores, can prove beneficial. 2.The derivation of seven new indices is described, summarizing nearly half of the variables used by RHS and providing a quantitative overall summary of river reaches. 3.Derived using an objective analysis of the RHS database (cf expert judgement), one index describes bedrock/boulder channels, two indices describe bank and riparian vegetation and a further two describe aspects of sediment transport and deposition. Two distinct types of modification,,,bank reinforcement and channel re-sectioning,,,are also quantified. 4.Rigorous testing indicates that the indices are reliable across the complete range of conditions and countries in the UK. 5.The new indices are readily interpreted and while providing a simple overview of a river reach, they are objective and quantitative, lending themselves to a range of management and research applications. They have already been used successfully in quantifying riverine bird habitats and this, along with other applications, is discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||