bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenotypic Plasticity in Growth Habit in Plantago lanceolata: How Tight is a Suite of Correlated Characters?
Authors: VAN TIENDEREN PETER H. , VAN HINSBERG ARJEN 
Published: February 2005

Abstract The growth habit of the rosette plant Plantago lanceolata is highly variable, and many vegetative and reproductive traits co‐vary. At one end of the range plants have relatively few but long and erect leaves, form few daughter rosettes, and produce a limited number of large spikes, with relatively heavy seeds. Plants at the other end of the range have the opposite characteristics. This suite of characters was shown to correlate with the height of the vegetation in mid‐summer. The causes for this association between different traits were investigated in different experiments, with the following results:

Plants from two contrasting habitats both react strongly to light intensity and the red to far‐red (R/FR) ratio of the ambient light. Light intensity mainly affected plant size, whereas light quality affected the growth habit. Populations differ in their mean response rather than in the level of plasticity (i.e., slope of the reaction norms). Experiments show that genetic factors (population effects), R/FR ratio, and hormone treatments (GA or CCC) have similar effects on morphology, and are largely additive and interchangeable.
Ten different populations were grown in a common garden, so that the genetic (clonal) correlation within populations, and their bivariate phenotypic means could be compared. Trait combinations which deviated in the same direction (both higher of both lower than the mean over all populations) on average had positive clonal correlations within populations, whereas combinations which deviated in opposite directions had negative correlations.
Artificial selection on leaf length, performed under a high or a low R/FR ratio showed clear responses to selection, with heritabilities around 0.4. Correlated responses were found in many other traits, and genetic correlations were similar to the trait associations for the means of different natural populations. Correlated responses to selection depended on environmental circumstances. Under a high R/FR ratio (sun) evidence for a size/number trade‐off was found for leaf length and leaf number. Under a low R/FR ratio, however, a trade‐off between leaf length and leaf quality was found.
In conclusion, the trait associations that are so characteristic for the growth habit in Plantago lanceolata are probably due to differences in hormone levels or activities. Genes and environmental factors affect growth habit in similar ways, by tapping into this regulatory mechanism. In the field, selection can lead to concerted changes in the mean of different traits, but changes in plasticity will be slow.
Reversible posterior leukoencephalopathy syndrome: a misnomer reviewed
Authors: Stott V. L. , Hurrell M. A. , Anderson T. J. 
Published: February 2005

Abstract Reversible posterior leukoencephalopathy is a syndrome of headache, seizures and visual loss, often associated with an abrupt increase in blood pressure. Prompt diagnosis and therapy with antihypertensives, anticonvulsants, removal of any offending medication and treatment of associated disorders is essential since early treatment might prevent progression to irreversible brain damage. We present six illustrative cases presenting to Christchurch Hospital and review the condition. All were hypertensive, two were receiving immunosuppressant therapy after transplantation and one chemotherapy. Only three made a full recovery. The term reversible posterior leukoencephalopathy is a misnomer as the condition is not always reversible, is not necessarily confined to the posterior regions of the brain and can affect both white and grey matter. Magnetic resonance imaging findings of increased T2 and fluid attenuated inversion recovery signal predominantly involving the posterior regions of the cerebral hemispheres should alert the clinician to the possibility of this diagnosis. (Intern Med J 2005; 35: 83–90)
Fatigue crack propagation in Ti–6Al–4V subjected to high strain amplitudes
Authors: ANDERSSON M. , HANSSON T. , PERSSON C. , MELIN S. 
Published: February 2005

ABSTRACTFatigue crack propagation in circular Ti–6Al–4V specimens subjected to high strain amplitudes has been investigated. Crack closure was measured with an electrical potential‐drop technique. Closure was shown not to depend on strain ratio but to be a function of the applied strain range. At higher strain ranges, the crack was found to be closed for a smaller part of the load cycle than at lower strain ranges due to blunting of the crack tip. Furthermore, the use of a strain‐intensity approach to predict crack‐propagation rate was investigated, and it was found that for the upper parts of the da/dN curves the effective strain intensity yields good predictions. Also, the effective stress‐intensity factor was found to collapse the da/dN curves for different load ratios.
A probabilistic two‐scale model for high‐cycle fatigue life predictions
Authors: DOUDARD C. , CALLOCH S. , CUGY P. , GALTIER A. , HILD F. 
Published: February 2005

ABSTRACTIt is proposed to develop and identify a probabilistic two‐scale model for HCF that accounts for the failure of samples, but also for the thermal effects during cyclic loadings in a unified framework. The probabilistic model is based on a Poisson point process. Within the weakest link theory, the model corresponds to a Weibull law for the fatigue limits. The thermal effects can be described if one considers the same hypotheses apart from the weakest link assumption. A method of identification is proposed and uses temperature measurements to identify the scatter in an S/N curve. The validation of the model is obtained by predicting S/N curves for different effective volumes of a dual‐phase steel.
Fatigue as a process of cyclic brittle microfracture
Authors: SUNDER R. 
Published: February 2005

ABSTRACTWhile fatigue crack growth in vacuum may occur by slip alone, environmental fatigue including crack growth in air is strongly influenced by crack‐tip surface chemistry that adversely affects ductility. Cumulative diffusion, combined with adsorption and chemisorption in the loading half‐cycle may promote instantaneous crack extension by brittle microfracture (BMF). Unlike slip, the BMF component will be sensitive to parameters that affect near‐tip stresses, such as load history and constraint. BMF dominates near‐threshold environmental fatigue. Being a surface phenomenon, it loses its significance with increasing growth rate, as slip‐driven crack extension gains momentum and growth becomes less sensitive to environment. The BMF model provides for the first time, a scientific rationale for the residual stress effect as well as the related connection between stress–strain hysteresis and load‐sequence sensitivity of metal fatigue including notch response. Experimental evidence obtained on a variety of materials under different loading conditions in air and vacuum appears to support the proposed model and its implications.
Structural behaviour of aeronautical tungsten carbide/carbon‐coated titanium ball screws under space thermal‐vacuum conditions
Authors: CORRADI S. , MARCHETTI M. 
Published: February 2005

ABSTRACTIn view of the pressing need for improvements in space mechanisms and tribology research work, a thermal high‐vacuum mechanism test facility has been constructed at Rome ‘La Sapienza’ University. The purpose of this facility is to provide fundamental data on the performance of mechanical components and materials in high vacuum in order to test the validity of space mechanism designs. The facility also makes it possible to examine the behaviour of both mechanisms and materials under combined environmental factors, such as ultraviolet radiation, atomic oxygen and temperature. This paper reports on the behaviour of titanium recirculating ball screws provided by Umbra Cuscinetti SpA (Foligno, Italy) under thermal‐vacuum conditions. It is to be noted that these ball screws—well known in the aeronautical field—may be particularly attractive as a new generation of space mechanisms. A solid multilayer film of tungsten carbide/carbon (WC/C) was deposited on screw surfaces as a lubricant and was then compared with the case of no lubrication, which presently appears promising for many mechanisms. In order to compare experimental results, traditional stainless steel mechanisms were also tested and analysed. The requisites imposed by the space environment, as well as by contact mechanical stresses, have given useful information on a preliminary geometrical configuration and choice of materials, both of which are presented in this paper. Thermal‐vacuum effects on overall ball screw efficiency and on ball screw coating friction and wear are also reported and commented on herein as well as numerical contact simulations of crack mechanisms.
Identification and possible functions of ADAM33 as an asthma susceptibility gene
Authors: Holgate S. T. , Davies D. E. , Rorke S. , Cakebread J. , Murphy G. , Powell R. M. , Holloway J. W. 
Published: February 2005

SummaryAsthma is a disorder of the conducting airways in which Th‐2 mediated inflammation interacts with structural changes to cause variable airflow obstruction. Fundamental to disordered function is the concept of bronchial hyperresponsiveness (BHR), in which the airways construct too much and too easily. It has been stated that BHR represents the ‘Holy Grail’ of asthma, yet our understanding of its underlying causes(s) is poorly developed [1]. Measurement of BHR has found clinical utility as a diagnostic test to help differentiate asthma from other lung disorders, but unfortunately its specificity is low. However, it is the severity of BHR and its relative independence from measures of baseline airway calibre that differentiates BHR encountered in asthma from that of other diseases such as chronic obstructive pulmonary disease (COPD), sarcoidosis and heart failure.
Function of Siglec‐8 on human eosinophils
Authors: Nutku E. , Aizawa H. , Hudson S. , Bochner B. S. 
Published: February 2005

SummaryEosinophil recruitment and activation are regarded as central to the pathophysiology of allergic diseases, including asthma. An improved understanding of the mechanisms involved in these responses is therefore of great relevance to asthma pathogenesis and the development of new therapeutics. As part of ongoing efforts to discover novel eosinophil‐specific molecules, we recently cloned Siglec‐8 (formerly called sialoadhesin family member‐2) from a human eosinophil cDNA library. Siglecs (sialic acid binding Ig‐like lectins) are a family of transmembrane, I‐type lectins characterized by an N‐terminal V‐set Ig domain that binds sialic acid. We now know that Siglec‐8 is expressed only on human eosinophils, basophils and mast cells, giving it a unique expression pattern on effector cells of allergic disease. We have determined that in eosinophils, Siglec‐8 exists in two isoforms, one of which contains two putative cytoplasmic tyrosine‐based signalling motifs, including an ITIM (immunoreceptor tyrosine‐based inhibitory motif) sequence. Because of the ITIM sequence, we hypothesized that Siglec‐8 ligation would inhibit eosinophil functions. Initial studies found that incubation of eosinophils with Siglec‐8 binding monoclonal antibodies under cross‐linking conditions caused rapid and profound caspase‐dependent apoptosis, and this response could not be rescued by the survival‐promoting cytokine interleukin (IL)‐5. In fact, IL‐5 enhanced the ability of Siglec‐8 cross‐linking to induce eosinophil apoptosis. Activation via Siglec‐8 could potentially be used to inhibit eosinophil survival in vivo, providing a novel strategy for reducing or inhibiting these cells in allergic and other diseases.
Mast cell localization within the airway smooth muscle: relationship to airway hyperresponsiveness and other asthma phenotypes
Authors: Wardlaw A. J. , Bradding P. , Pavord I. D. , Brightling C. E. 
Published: February 2005

SummaryAsthma is a condition characterized by variable airflow obstruction, airway hyperresponsiveness (AHR) and airway inflammation which is usually, but not invariably, eosinophilic. Current thoughts on the pathogenesis of asthma are focused on the idea that it is caused by an inappropriate response of the specific immune system to harmless antigens, particularly allergens such as cat dander and house dust mite, that result in Th2‐mediated chronic inflammation. However, the relationship between inflammation and asthma is complex with no good correlation between the severity of inflammation, at least as measured by the number of eosinophils, and the severity of asthma. In addition there are a number of conditions such as eosinophilic bronchitis and allergic rhinitis in which there is a Th2‐mediated inflammatory response, but no asthma as measured by variable airflow obstruction or AHR. When we compared the immunopathology of eosinophilic bronchitis and asthma the only difference we observed was that in asthma the airway smooth muscle (ASM) was infiltrated by mast cells, suggesting that the airways obstruction and AHR was due to an ASM mast cell myositis. This observation emphasizes that the features that characterize asthma, as opposed to bronchitis, are due to abnormalities in smooth muscle responsiveness which could be intrinsic or acquired and that inflammation is only relevant in that it leads to those abnormalities. It also emphasizes the importance of microlocalization as an organizing principle in physiological responses to airway inflammation. The factors controlling the compartmentalization of leucocyte subsets within the bronchial mucosa are therefore of paramount importance and are discussed.
Dendritic cells in the pathogenesis of asthma
Authors: Lambrecht B. N. , Kuipers H. , Van Rijt L. , Hammad H. 
Published: February 2005

SummaryDendritic cells are mainly recognized for their potential to induce primary immune responses to foreign antigens. In allergic asthma, airway dendritic cells are at the very heart of the sensitization process, leading to stable Th2 immunity to commonly inhaled aeroallergens. Recently however, a role for dendritic cells beyond sensitization has been suggested. These studies show that airway DCs control the secondary immune response typical of late asthmatic reactions by recruiting and activating primed Th2 cells locally in the airways.
Generation of cytokines through the leucocyte immunoglobulin‐like receptors
Authors: Arm J. P. 
Published: February 2005

SummaryThe LIRs comprise a family of immunoregulatory receptors with activating and inhibitory members as well as soluble forms of the receptors. These receptors are part of the larger context of other families of activating and inhibitory receptors, some of which are closely related members of the immunoglobulin superfamily and others of which are C‐type lectin receptors. In vitro data have demonstrated the capacity of the inhibitory LIRs to regulate the threshold and amplitude of cellular responses to diverse agonists. The emerging data on the activating receptors indicate that they may elicit release of preformed, granule‐associated mediators, de novo lipid mediator generation and cytokine release either from preformed stores or by gene induction. The identification of ligands for the LIRs is limited currently to the recognition of a broad array of MHC class I molecules by LIR1 and LIR2 (and possibly LIR6). Gene disruption studies of the closest mouse homologues of the inhibitory LIRs support the hypothesis that the LIRs may regulate inflammatory responses, particularly those dependent on the mast cell and/or Th2 cell‐dependent humoral responses. The relative balance of inhibitory and activating LIRs expressed by a particular cell, the differential regulation of their putative ligands, whether endogenous host‐related or exogenous pathogen‐related, and the exposure of the LIRs to those ligands may play an important role in determining cellular activation responses and the development and resolution of tissue inflammation.
Epithelial responses in airway inflammation and immunity
Authors: Schleimer R. P. , Sha Q. , Vandermeer J. , Lane A. P. , Kim J. 
Published: February 2005

SummaryThe epithelium is thought to serve an important barrier function in the airways. However, growing evidence now supports the notion that the respiratory epithelium plays a key role in host responses to infectious and allergenic stimuli. The epithelium functions to produce a variety of proinflammatory cytokines during the inflammatory response. More recently, the epithelium has been shown to express a variety of receptors that can recognize microorganisms, such as toll‐like receptors (TLRs), as well as complement and acute phase proteins. Additionally, the cell surface of epithelial cells have also been shown to express a variety of costimulatory molecules which may be involved in regulating the activation of antigen‐specific T cells in the airways. This paper reviews the novel ways by which the epithelium may function in both the innate and adaptive immune responses of the airways.
Glucocorticoid‐resistant asthma
Authors: Corrigan C. J. , Hawrylowicz C. M. , Lavender P. , Lee T. H. 
Published: February 2005

SummaryIn the past decade it has become clear that asthmatic patients who are clinically unresponsive, or “resistant” to glucocorticoid therapy may have T cells which manifest resistance to glucocorticoid inhibition. This is shown by failure of glucocorticoid not only to repress the production of pro‐inflammatory, asthma‐relevant cytokines such as IL‐5, but also to induce the production of anti‐inflammatory cytokines, such as IL‐10. Molecular mechanisms underlying this resistance are beginning to be defined, and include inappropriate production of transcriptional regulatory proteins (which may bind to and inactivate the glucocorticoid receptor), cytokine‐induced modifications of the glucocorticoid receptor (such as phosphorylation), which alter its capacity to bind to ligand, and complex interactions which regulate histone acetylation status and the quaternary structure of DNA itself. Continued study of these phenomena will lead to a better understanding of the “normal” physiological mechanisms of glucocorticoid action, and may point to new, alternative avenues of therapy for glucocorticoid resistant asthmatics who suffer from severe disease, and for whom as yet no adequate therapy is available.
Management of fixed airflow limitation caused by asthma or chronic obstructive pulmonary disease
Authors: Romagnoli M. , Luppi F. , Corbetta L. , Papi A. , Fabbri L. M. 
Published: February 2005

SummaryPatients with fixed airflow limitation are often classified as chronic obstructive pulmonary disease (COPD), and some international guidelines recommend classifying asthma with fixed airflow limitation as COPD. Indeed, both COPD (induced by smoking or other noxious agents) and asthma may be associated with a decline of lung function that causes fixed airflow limitation. In the presence of fixed airflow limitation, patients are often diagnosed COPD, even if the differential diagnosis between asthma and COPD in these patients may be important as the natural history as well as the response to treatment are different, depending on whether fixed airflow limitation is due to asthma or COPD. The assessment of patients presenting with fixed airflow limitation has recently highlighted that airway inflammation is markedly different in asthma and COPD although characterized by the same degree of airflow limitation. Thus, asthma with fixed airflow limitation maintain the same pathological characteristics as asthma with completely reversible airflow limitation. In conclusion, subjects with fixed airflow limitation due to asthma have distinct characteristics compared with subjects with COPD, and they should be diagnosed and treated accordingly.
Leukotrienes and other mast cell mediators cause asthmatic airway obstruction
Authors: Dahlén S.‐E. , Sundström E. , Gulliksson M. , Gyllfors P. , Kumlin M. , Dahlén B. 
Published: February 2005

SummaryFrom an evolutionary perspective, bronchoconstriction is a highly conserved mechanism for defence against stimuli that are noxious for the lung and airways. The presence of mast cells in all layers of the airways makes them ideally situated to function as sensors of environmental changes that require such a host defence reaction. In addition to being activated by high affinity IgE receptors, many other trigger factors are known to activate signal transduction pathways leading to mast cell degranulation. This includes changes in the physical and chemical composition of the environment, exposure to endotoxin and other microbial factors acting on Toll‐like receptors [1], intake of certain drugs and in particular virtually all nonsteroidal anti‐inflammatory drugs (NSAIDs) in subjects with the peculiar syndrome aspirin‐intolerant asthma (AIA) [2]. Irrespective of the trigger, the consequence of mast cell activation is release of biologically active smooth muscle stimulating mediators as well as the secretion of cytokines, chemotactic factors and enzymes that are believed to trigger further cascades contributing to long‐term tissue remodelling and chronic airway inflammation.
Strategies for early prevention of asthma
Authors: De Benedictis Fernando Maria , Franceschini Fabrizio , Carnielli Virgilio , Tonietti Giorgio 
Published: February 2005

SummaryAsthma is the most commonly diagnosed chronic disease in childhood. Pathogenesis of the disease has received much attention lately as the last few decades have seen such a global rise in prevalence. There is hope to reverse this trend in prevalence by developing new preventive strategies.Here, we summarize the recent evidence for the role of early life events such as prenatal factors, infections, pollution, allergen exposure, nutrition, and discuss the implications for future strategies for asthma prevention.
Polymorphic microsatellite loci for the swarm‐founding wasp Polybia paulista (Hymenoptera: Vespidae)
Authors: KUDÔ Kazuyuki , ISHIGURO Norio , TSUCHIDA Koji , TSUJITA Sumiko , YAMANE Sôichi , ZUCCHI Ronaldo 
Published: February 2005

AbstractA polymorphic microsatellite locus was isolated and characterized from Polybia paulista, one of the most common polygynic, swarm‐founding social wasps in Brazil. Three other microsatellite loci for which the primer sets were originally developed in independent‐founding paper wasps also showed polymorphism in the size of amplification products in P. paulista.
A new species of Pulvinaria (Homoptera: Coccidae) and a new locality record of Pulvinaria neocellulosa
Authors: TANAKA Hirotaka , AMANO Hiroshi 
Published: February 2005

AbstractA new soft scale insect of the tribe Pulvinariini, Pulvinaria hakonensis sp. nov., is described from Japan based on several adult females. The lectotype of Pulvinaria neocellulosa Takahashi, 1940 is designated and the species is redescribed and recorded from Japan for the first time.
Taxonomic review of the genus Xenolecanium Takahashi and description of the new genus Takahashilecanium Kondo (Hemiptera: Coccidae; Coccinae, Paralecaniini)
Authors: KONDO Takumasa , WILLIAMS Michael L. , GULLAN Penny J. 
Published: February 2005

AbstractThe genus Xenolecanium Takahashi is reviewed and transferred from the subfamily Myzolecaniinae to the Coccinae (tribe Paralecaniini). The type species Xenolecanium mangiferae Takahashi is redescribed, and Xenolecanium takahashii Kondo sp. nov. from Indonesia is described based on the adult female and first instar nymph. A taxonomic key is provided to separate adult females of the two species of Xenolecanium. Xenolecanium rotundum Takahashi is transferred to become the type species of a new monotypic genus, Takahashilecanium Kondo, which is also placed in the Paralecaniini. The morphological justification for placing Xenolecanium and Takahashilecanium in the Paralecaniini is discussed, and we provide a taxonomic key for separating both genera from all other members of the Paralecaniini.