Showing papers by "University of Leeds published in 1998"
TL;DR: In this article, the authors describe and review the theory of planned behavior (TPB) and present evidence supporting the further extension of the TPB in various ways, such as belief salience measures, past behavior, selfefficacy, moral norms, self-identity, and affective beliefs.
Abstract: This paper describes and reviews the theory of planned behavior (TPB). The focus is on evidence supporting the further extension of the TPB in various ways. Empirical and theoretical evidence to support the addition of 6 variables to the TPB is reviewed: belief salience measures, past behaviodhabit, perceived behavioral control (PBC) vs. selfefficacy, moral norms, self-identity, and affective beliefs. In each case there appears to be growing empirical evidence to support their addition to the TPB and some understanding of the processes by which they may be related to other TPB variables, intentions, and behavior. Two avenues for expansion of the TPB are presented. First, the possibility of incorporating the TPB into a dual-process model of attitude-behavior relationships is reviewed. Second, the expansion of the TPB to include consideration of the volitional processes determining how goal intentions may lead to goal achievement is discussed.
2,913 citations
TL;DR: It is shown that dispersal and interactions, which are important elements of population dynamics, must be included in predictions of biotic responses to climate change.
Abstract: Many attempts to predict the biotic responses to climate change rely on the 'climate envelope' approach, in which the current distribution of a species is mapped in climate-space and then, if the position of that climate-space changes, the distribution of the species is predicted to shift accordingly. The flaw in this approach is that distributions of species also reflect the influence of interactions with other species, so predictions based on climate envelopes may be very misleading if the interactions between species are altered by climate change. An additional problem is that current distributions may be the result of sources and sinks, in which species appear to thrive in places where they really persist only because individuals disperse into them from elsewhere. Here we use microcosm experiments on simple but realistic assemblages to show how misleading the climate envelope approach can be. We show that dispersal and interactions, which are important elements of population dynamics, must be included in predictions of biotic responses to climate change.
1,161 citations
TL;DR: A gradient from near-primary, through old-growth secondary and plantation forests to complete clearance, for eight animal groups in the Mbalmayo Forest Reserve, south-central Cameroon is examined, indicating the huge scale of the biological effort required to provide inventories of tropical diversity, and to measure the impacts of tropical forest modification and clearance.
Abstract: Despite concern about the effects of tropical forest disturbance and clearance on biodiversity1,2, data on impacts, particularly on invertebrates, remain scarce3,4,5,6,7,8. Here we report a taxonomically diverse inventory on the impacts of tropical forest modification at one locality. We examined a gradient from near-primary, through old-growth secondary and plantation forests to complete clearance, for eight animal groups (birds, butterflies, flying beetles, canopy beetles, canopy ants, leaf-litter ants, termites and soil nematodes) in the Mbalmayo Forest Reserve, south-central Cameroon. Although species richness generally declined with increasing disturbance, no one group serves as a good indicator taxon9,10,11,12 for changes in the species richness of other groups. Species replacement from site to site (turnover) along the gradient also differs between taxonomic groups. The proportion of ‘morphospecies’ that cannot be assigned to named species and the number of ‘scientist-hours’ required to process samples both increase dramatically for smaller-bodied taxa. Data from these eight groups indicate the huge scale of the biological effort required to provide inventories of tropical diversity, and to measure the impacts of tropical forest modification and clearance.
1,119 citations
TL;DR: The main focus of the Hymer-Kindleberger theory (Hymer, 1976; Kindleberger, 1969) and the product cycle theory (Vernon 1966) was exporting versus FDI as mentioned in this paper.
Abstract: Empirical studies of FDI have become much more ambitious in scope over the last 30 years. In the 1960s, the main focus of the Hymer-Kindleberger theory (Hymer, 1976; Kindleberger, 1969) and the product cycle theory (Vernon 1966) was exporting versus FDI. In the 1970s the internalisation approach identified licensing, franchising and subcontracting as other strategic options. The resurgence of mergers and acquisitions in the 1980s — often as a ‘quick fix’ route to globalisation — highlighted the choice between greenfield ventures and acquisitions. At the same time, the growing participation of US firms in IJVs drew attention to the role of cooperative arrangements.
885 citations
TL;DR: In this article, the authors compare various measures of sample skewness and kurtosis, focusing on bias and mean-squared error for normal samples, and presenting some comparisons from simulation results for non-normal samples.
Abstract: Over the years, various measures of sample skewness and kurtosis have been proposed. Comparisons are made between those measures adopted by well-known statistical computing packages, focusing on bias and mean-squared error for normal samples, and presenting some comparisons from simulation results for non-normal samples.
873 citations
TL;DR: Mortality rates due to colon cancer, all malignant disease, cardiovascular disease and overall mortality were increased with higher posttreatment GH leve...
Abstract: Patients with acromegaly have a reduced life expectancy, with the accepted causes for premature death being vascular and respiratory disease. Increased mortality from malignant disease has also been reported. We, therefore, performed a multicenter retrospective cohort study of 1362 patients with acromegaly and investigated the relationships of mortality and cancer incidence with GH levels, duration of disease, and age at diagnosis. The overall cancer incidence rate [standardized incidence ratio, 0.76; 95% confidence interval (CI), 0.60–0.95] was lower than that in the general population of the United Kingdom, and there was no significant increase in site-specific cancer incidence rates. The overall cancer mortality rate was not increased, but the colon cancer mortality rate (standardized mortality ratio, 2.47; 95% CI, 1.31–4.22) was higher than expected. Mortality rates due to colon cancer, all malignant disease, cardiovascular disease and overall mortality were increased with higher posttreatment GH leve...
854 citations
TL;DR: The current taxonomic status of S. maltophilia is reviewed, the epidemiology of the organism is considered with particular reference to nosocomial outbreaks, and the laboratory identification of the bacterium is discussed.
Abstract: The gram-negative bacterium Stenotrophomonas maltophilia is increasingly recognized as an important cause of nosocomial infection. Infection occurs principally, but not exclusively, in debilitated and immunosuppressed individuals. Management of S. maltophilia-associated infection is problematic because many strains of the bacterium manifest resistance to multiple antibiotics. These difficulties are compounded by methodological problems in in vitro susceptibility testing for which there are, as yet, no formal guidelines. Despite its acknowledged importance as a nosocomial pathogen, little is known of the epidemiology of S. maltophilia, and although it is considered an environmental bacterium, its sources and reservoirs are often not readily apparent. Molecular typing systems may contribute to our knowledge of the epidemiology of S. maltophilia infection, thus allowing the development of strategies to interrupt the transmission of the bacterium in the hospital setting. Even less is known of pathogenic mechanisms and putative virulence factors involved in the natural history of S. maltophilia infection and this, coupled with difficulties in distinguishing colonization from true infection, has fostered the view that the bacterium is essentially nonpathogenic. This article aims to review the current taxonomic status of S. maltophilia, and it discusses the laboratory identification of the bacterium. The epidemiology of the organism is considered with particular reference to nosocomial outbreaks, several of which have been investigated by molecular typing techniques. Risk factors for acquisition of the bacterium are also reviewed, and the ever-expanding spectrum of clinical syndromes associated with S. maltophilia is surveyed. Antimicrobial resistance mechanisms, pitfalls in in vitro susceptibility testing, and therapy of S. maltophilia infections are also discussed.
838 citations
TL;DR: In this article, a model of a single large plume impinging beneath the Ethiopian plateau is presented, which takes into account lateral flow and ponding of plume material in pre-existing zones of lithospheric thinning.
Abstract: The geology of northern and central Africa is characterized by broad plateaux, narrower swells and volcanism occurring from ∼45 Myr ago to the present. The greatest magma volumes occur on the >1,000-km-wide Ethiopian and east African plateaux, which are transected by the Red Sea, Gulf of Aden and east African rift systems, active since the late Oligocene epoch. Evidence for one or more mantle plumes having impinged beneath the plateaux comes from the dynamic compensation inferred from gravity studies, the generally small degrees of extension observed and the geochemistry of voluminous eruptive products1,2,3,4. Here we present a model of a single large plume impinging beneath the Ethiopian plateau that takes into account lateral flow and ponding of plume material in pre-existing zones of lithospheric thinning5. We show that this single plume can explain the distribution and timing of magmatism and uplift throughout east Africa. The thin lithosphere beneath the Mesozoic–Palaeogene rifts and passive margins of Africa and Arabia guides the lateral flow of plume material west to the Cameroon volcanic line and south to the Comoros Islands. Our results demonstrate the strong control that the lithosphere exerts on the spatial distribution of plume-related melting and magmatism.
763 citations
TL;DR: In this article, a molecular constitutive equation for an idealized polymer architecture, called a pom-pom, has been proposed, which predicts rheology in both shear and extension.
Abstract: Polymer melts with long-chain side branches and more than one junction point, such as commercial low density polyethylene (LDPE), have extensional rheology characterized by extreme strain hardening, while the shear rheology is very shear thinning, much like that of unbranched polymers. Working with the tube model for entangled polymer melts, we propose a molecular constitutive equation for an idealized polymer architecture, which, like LDPE, has multiple branch points per molecule. The idealized molecule, called a “pom-pom,” has a single backbone with multiple branches emerging from each end. Because these branches are entangled with the surrounding molecules, the backbone can readily be stretched in an extensional flow, producing strain hardening. In start-up of shear, however, the backbone stretches only temporarily, and eventually collapses as the molecule is aligned, producing strain softening. Here we develop a differential/integral constitutive equation for this architecture, and show that it predicts rheology in both shear and extension that is qualitatively like that of LDPE, much more so than is possible with, for example, the K-BKZ integral constitutive equation.
724 citations
TL;DR: In this article, the effects of the initial mixture temperature and pressure on these parameters also have been examined and data have been obtained for iso-octane-air mixtures at initial temperatures between 358 K and 450 K, at pressures between 1 and 10 bar, and equivalence ratios, φ, of 0.8 and 1.0.
664 citations
TL;DR: In this paper, the authors examined difficulties inherent in the analysis of oxo8dG, identified sources of artifacts, and provided solutions to some of the common methodological problems, concluding that phenol extraction of DNA contributes a real but minor increase in the measured level of oxoxo8DG when compared, under equivalent conditions, with a successful nonphenol method.
Abstract: Oxidative DNA damage is important in aging and the degenerative diseases of aging such as cancer. Estimates commonly rely on measurements of 8-oxo-2′-deoxyguanosine (oxo8dG), an adduct that occurs in DNA and is also excreted in urine after DNA repair. Here we examine difficulties inherent in the analysis of oxo8dG, identify sources of artifacts, and provide solutions to some of the common methodological problems. A frequent criticism has been that phenol in DNA extraction solutions artificially increases the measured level of oxo8dG. We found that phenol extraction of DNA contributes a real but minor increase in the level of oxo8dG when compared, under equivalent conditions, with a successful nonphenol method. A more significant reduction in the baseline level was achieved with a modification of the recently introduced chaotropic NaI method, reducing our estimate of the level of steady-state oxidative adducts by an order of magnitude to 24,000 adducts per cell in young rats and 66,000 adducts per cell in old rats. Of several alternative methods tested, the use of this chaotropic technique of DNA isolation by using NaI produced the lowest and least variable oxo8dG values. In further studies we show that human urinary 8-oxo-guanine (oxo8Gua) excretion is not affected by the administration of allopurinol, suggesting that, unlike some methylated adducts, oxo8Gua is not derived enzymatically from xanthine oxidase. Lastly, we discuss remaining uncertainties inherent both in steady-state oxo8dG measurements and in estimates of endogenous oxidation (“hit rates”) based on urinary excretion of oxo8dG and oxo8Gua.
TL;DR: The identification of two genes, WISP-1 and W ISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnnt-4 are reported, suggesting that the WISp genes may be downstream of WNT-1 signaling and that aberrant levels of WISPs expression in colon cancer may play a role in colon tumorigenesis.
Abstract: Wnt family members are critical to many developmental processes, and components of the Wnt signaling pathway have been linked to tumorigenesis in familial and sporadic colon carcinomas. Here we report the identification of two genes, WISP-1 and WISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnt-4. Together with a third related gene, WISP-3, these proteins define a subfamily of the connective tissue growth factor family. Two distinct systems demonstrated WISP induction to be associated with the expression of Wnt-1. These included (i) C57MG cells infected with a Wnt-1 retroviral vector or expressing Wnt-1 under the control of a tetracyline repressible promoter, and (ii) Wnt-1 transgenic mice. The WISP-1 gene was localized to human chromosome 8q24.1-8q24.3. WISP-1 genomic DNA was amplified in colon cancer cell lines and in human colon tumors and its RNA overexpressed (2- to >30-fold) in 84% of the tumors examined compared with patient-matched normal mucosa. WISP-3 mapped to chromosome 6q22-6q23 and also was overexpressed (4- to >40-fold) in 63% of the colon tumors analyzed. In contrast, WISP-2 mapped to human chromosome 20q12-20q13 and its DNA was amplified, but RNA expression was reduced (2- to >30-fold) in 79% of the tumors. These results suggest that the WISP genes may be downstream of Wnt-1 signaling and that aberrant levels of WISP expression in colon cancer may play a role in colon tumorigenesis.
TL;DR: Under-reporting of food intake is one of the fundamental obstacles preventing the collection of accurate habitual dietary intake data and requires a multidisciplinary approach (including psychology, sociology and physiology) to advance the understanding of under-reporting in dietary intake studies.
Abstract: Under-reporting of food intake is one of the fundamental obstacles preventing the collection of accurate habitual dietary intake data. The prevalence of under-reporting in large nutritional surveys ranges from 18 to 54% of the whole sample, but can be as high as 70% in particular subgroups. This wide variation between studies is partly due to different criteria used to identify under-reporters and also to non-uniformity of under-reporting across populations. The most consistent differences found are between men and women and between groups differing in body mass index. Women are more likely to under-report than men, and under-reporting is more common among overweight and obese individuals. Other associated characteristics, for which there is less consistent evidence, include age, smoking habits, level of education, social class, physical activity and dietary restraint. Determining whether under-reporting is specific to macronutrients or food is problematic, as most methods identify only low energy intakes. Studies that have attempted to measure under-reporting specific to macronutrients express nutrients as percentage of energy and have tended to find carbohydrate under-reported and protein over-reported. However, care must be taken when interpreting these results, especially when data are expressed as percentages. A logical conclusion is that food items with a negative health image (e.g. cakes, sweets, confectionery) are more likely to be under-reported, whereas those with a positive health image are more likely to be over-reported (e.g. fruits and vegetables). This also suggests that dietary fat is likely to be under-reported. However, it is necessary to distinguish between under-reporting and genuine under-eating for the duration of data collection. The key to understanding this problem, but one that has been widely neglected, concerns the processes that cause people to under-report their food intakes. The little work that has been done has simply confirmed the complexity of this issue. The importance of obtaining accurate estimates of habitual dietary intakes so as to assess health correlates of food consumption can be contrasted with the poor quality of data collected. This phenomenon should be considered a priority research area. Moreover, misreporting is not simply a nutritionist's problem, but requires a multidisciplinary approach (including psychology, sociology and physiology) to advance the understanding of under-reporting in dietary intake studies.
TL;DR: The authors found that an individual's current state of appetite has a significant effect on choices that apply to the future and that the preferences that should be relevant are those that will prevail when the consequences occur.
TL;DR: Particulate wear debris from total hip prosthetic components can stimulate macrophages to produce mediators of osteolysis which may cause aseptic implant loosening and particles in the phagocytosable size range of 0.3-10 microm appear to be the most biologically active.
TL;DR: The need for detailed categorization is emphasized, particularly for those interested in the development of this component of proficiency in a second language acquisition, in discussing the major approaches to the linguistic description of prefabricated language.
Abstract: It is now generally accepted that advanced learners of English need to have command of a wide range of complex lexical units, which are for a native speaker processed as prefabricated chunks, fixed, or semi-fixed expressions. However, although there has been an increasing amount written about the role of phraseology in second language acquisition, there remains a lack of detailed description of learners' phraseological performance as the basis for understanding how phraseological competence develops. This paper addresses certain current issues in the description of collocations in English, and, in discussing the major approaches to the linguistic description of prefabricated language, the need for detailed categorization is emphasized, particularly for those interested in the development of this component of proficiency in a second language. Data is presented from native speaker language use, illustrating what can be revealed by one such descriptive model. Finally, the findings of a number of studies of native and non-native academic writing in English are discussed
Book•
01 Dec 1998TL;DR: This chapter discusses the evolution of computer methods for the Handling of Spatial Data, and the role that modelling systems thinking and GIS have in this evolution.
Abstract: 1. What is GIS? 2. Concepts of Space 3. The Evolution of Computer Methods for the Handling of Spatial Data 4. Modelling Systems Thinking and GIS 5. Spatial Data Models 6. Attribute Data Management 7. Data Encoding and Manipulation 8. Data Analysis 9. Data Output 10. Data Quality Issues 11. Organisational Issues 12. Project Design
TL;DR: The appearance of a major work of survey and synthesis, which goes into successive editions (Caves, 1996) is a clear sign that a subject has reached maturity as mentioned in this paper, and so the question naturally arises as to whether stagnation has set in to international business research.
Abstract: The appearance of a major work of survey and synthesis, which goes into successive editions (Caves, 1996), is a clear sign that a subject has reached maturity. Maturity can sometimes indicate stagnation, however, and so the question naturally arises as to whether stagnation has set in to international business research. Caves’ second edition is an encyclopaedic work, but it is very much like the first edition in its general structure. Only the details have been modified in the light of recent research.
TL;DR: It is proposed that the synovitis of spondyloarthropathy is secondary to liberation of proinflammatory mediators from the enthesis, whereas the synvitis of rheumatoid arthritis is primary.
TL;DR: In this paper, the atmospheric degradation of 120 organic compounds and the associated regional scale ozone and PAN formation under conditions appropriate to the polluted boundary layer over northwest Europe were analyzed. And the robustness of these POCP values to changes in the NOx emission densities across Europe is tested and the values are compared with previous studies.
TL;DR: Antimicrobial susceptibility testing showed that A. baumannii outbreak strains were significantly more resistant to various broad-spectrum antimicrobial agents than sporadic strains, which may explain in part their propensity to cause prolonged outbreaks of nosocomial infection.
Abstract: Acinetobacter spp. are important nosocomial pathogens reported with increasing frequency in outbreaks of cross-infection during the past 2 decades. The majority of such outbreaks are caused by Acinetobacter baumannii. To investigate whether desiccation tolerance may be involved in the ability of certain strains of A. baumannii to cause hospital outbreaks, a blind study was carried out with 39 epidemiologically well-characterized clinical isolates of A. baumannii for which survival times were determined under simulated hospital conditions. The survival times on glass coverslips of 22 strains isolated from eight well-defined hospital outbreaks in a German metropolitan area were compared with the survival times of 17 sporadic strains not involved in outbreaks but rather isolated from inpatients in the same geographic area. All sporadic isolates have been shown by pulsed-field gel electrophoresis to represent different strain types. There was no statistically significant difference between the survival times of sporadic strains of A. baumannii and outbreak strains (27.2 versus 26.5 days, respectively; P ≤ 0.44) by the Wilcoxon-Mann-Whitney test. All investigated A. baumannii strains, irrespective of their areas of endemicity or epidemic occurrence, have the ability to survive for a long time on dry surfaces. Antimicrobial susceptibility testing showed that A. baumannii outbreak strains were significantly more resistant to various broad-spectrum antimicrobial agents than sporadic strains. Both desiccation tolerance and multidrug resistance may contribute to their maintenance in the hospital setting and may explain in part their propensity to cause prolonged outbreaks of nosocomial infection.
TL;DR: In this paper, an extensive qualitative case study of a “Big Six” firm is used to argue that being a professional in the firm is understood as being more to do with ways of conducting oneself than with possession of technical knowledge or being certified to practise.
Abstract: Material from an extensive qualitative case study of a “Big Six” firm is used to argue that being a professional in the firm is understood — by professionals themselves — as being more to do with ways of conducting oneself than with possession of technical knowledge or being certified to practise. Using documentary and interview materials, the complexities and tensions of these ways of conducting oneself are explored, as is their relationship to issues of fairness, physical appearance, gender, sexuality and hierarchy. The operation of concepts of the “firm type” and “the client” in mediating some of the tensions and paradoxes of being a professional are also explored.
TL;DR: Jacobson et al proposed a method of determining reliable and clinically significant change (RCSC) that summarises changes at the level of the individual in the context of observed changes for the whole sample.
Abstract: Where outcomes are unequivocal (life or death; being able to walk v being paralysed) clinicians, researchers, and patients find it easy to speak the same language in evaluating results. However, in much of mental health work initial states and outcomes of treatments are measured on continuous scales and the distribution of the “normal” often overlaps with the range of the “abnormal.” In this situation, clinicians and researchers often talk different languages about change data, and both are probably poor at conveying their thoughts to patients.
Researchers traditionally compare means between groups. Their statistical methods, using distributions of the scores before and after treatment to suggest whether change is a sampling artefact or a chance finding, have been known for many years.1 By contrast, clinicians are more often concerned with changes in particular individuals they are treating and often dichotomise outcome as “success” or “failure.” The number needed to treat (NNT) method of presenting results has gone some way to bridge this gap but often uses arbitrary criteria on which to dichotomise change into “success” and “failure.” A typical example is the criterion of a 50% drop on the Hamilton Depression Rating Scale score. A method bridging these approaches would assist the translation of research results into clinical practice.
Jacobson et al proposed a method of determining reliable and clinically significant change (RCSC) that summarises changes at the level of the individual in the context of observed changes for the whole sample.2, 3–5 Their methods are applicable, in one form or another, to the measurement of change on any continuous scale for any clinical problem, although they have been reported primarily in the psychotherapy research literature.
The broad concept of reliable and clinically significant change rests on 2 questions being addressed at the level of each …
TL;DR: The formation of iron biominerals is a two-step process: initially metals are electrostatically bound to the anionic surfaces of the cell wall and surrounding organic polymers, where they subsequently serve as nucleation sites for crystal growth as discussed by the authors.
TL;DR: In this article, an analytical theory of stress relaxation in monodisperse linear polymer melts that contains contributions from both reptation and contour-length fluctuations, modeled as in our previous work on arm retraction in star polymers, is presented.
Abstract: We present an analytical theory of stress relaxation in monodisperse linear polymer melts that contains contributions from both reptation and contour-length fluctuations, modeled as in our previous work on arm retraction in star polymers. Our approach resolves two long-standing problems with reptation theory: it predicts a zero-shear viscosity $\ensuremath{\eta}$ scaling as $\ensuremath{\eta}\ensuremath{\sim}{N}^{3.4}$ over a broad range in chain length $N$ before reaching an asymptotic ${N}^{3}$ dependence, and a power law ${\ensuremath{\omega}}^{\ensuremath{-}\ensuremath{\alpha}}$ in the dynamic loss modulus ${G}^{\ensuremath{'}\ensuremath{'}}(\ensuremath{\omega})$ with $0l\ensuremath{\alpha}l1/4$ depending on chain length, in agreement with experiment.
TL;DR: In this paper, a nitrogen purged static-bed batch reactor was used to pyrolyse 3 kg batches of shredded scrap tyres at temperatures between 450 and 600°C. The oils were trapped in a series of condensers and the derived gases analysed off-line by packed column gas chromatography.
TL;DR: In this article, the authors studied the factors affecting the nature and strength of electrostatic protein-polysaccharide interactions and proposed a method to predict how solution conditions such as pH and ionic strength influence food macromolecular functional properties.
Abstract: Proteins and polysaccharides are the two kinds of biopolymers used by food technologists to control structure, texture and stability. In any particular situation, the constituent protein molecules may be attracted towards the polysaccharide molecules (complexation) or repelled apart (segregation). The polyelectrolyte character of milk proteins and hydrocolloid stabilizers like carrageenan and pectin means that electrostatic interactions play an important role in determining mixed biopolymer behaviour. In order to be able to predict how solution conditions such as pH and ionic strength influence food macromolecular functional properties, we need to understand the factors affecting the nature and strength of electrostatic protein–polysaccharide interactions.
TL;DR: In this article, the authors considered the effect of multiple dissociation and recombination of the same pair of stickers and showed that this effect gives rise to an increase of the apparent activation energy which is predicted to be substantially larger than the priming activation energy for dissociation of two stickers.
Abstract: Viscoelastic properties of reversible networks formed in solutions of associating polymers are considered theoretically in the Rouse−Zimm (unentangled) regime. It is shown that the dynamics is governed primarily by the network strand size and by the effective lifetime of reversible junctions. Both frequency and concentration dependencies of viscosity and dynamical moduli are considered. A novel model taking into account the possibility of multiple dissociation and recombination of the same pair of stickers is developed. It is shown that this effect gives rise to an increase of the apparent activation energy which is predicted to be substantially larger than the priming activation energy for dissociation of two stickers.
TL;DR: A rat monoclonal antibody specific to a linear chain of (1→5)- α - l -arabinan which is a structural feature of the side chains of pectins will be useful for the localization of arabinans in plant tissue and will have uses in the analyses of pECTin structure.
TL;DR: In this paper, the coupling between density and chain conformation induces a liquid-liquid binodal within the equilibrium liquid-crystalline solid coexistence region, and several experimentally testable consequences are discussed.
Abstract: Recent experiments in some polymer melts quenched below the melting temperature have reported spinodal kinetics in small-angle x-ray scattering before the emergence of a crystalline structure. To explain these observations we propose that the coupling between density and chain conformation induces a liquid-liquid binodal within the equilibrium liquid-crystalline solid coexistence region. A simple phenomenological theory is developed to illustrate this idea, and several experimentally testable consequences are discussed. Shear is shown to enhance the kinetic role of the hidden binodal.