Showing papers by "University of Portsmouth published in 2001"
TL;DR: Evidence is presented that implicates heat shock proteins 70 and 90, chemokine receptor 4 and growth differentiation factor 5 as the main mediators of activation by bacterial lipopolysaccharide.
Abstract: Bacterial lipopolysaccharide (LPS), the major structural component of the outer wall of Gram-negative bacteria, is a potent initiator of an inflammatory response and serves as an indicator of bacterial infection. Although CD14 has been identified as the main LPS receptor, accumulating evidence has suggested the possible existence of other functional receptor(s). In this study, using affinity chromatography, peptide mass fingerprinting and fluorescence resonance energy transfer, we have identified four new proteins that form an activation cluster after LPS ligation and are involved in LPS signal transduction. Here we present evidence that implicates heat shock proteins 70 and 90, chemokine receptor 4 and growth differentiation factor 5 as the main mediators of activation by bacterial lipopolysaccharide.
433 citations
TL;DR: In this article, it was shown that the exterior of a spherical star is not in general a Schwarzschild spacetime, but has radiative-type stresses induced by five-dimensional graviton effects.
Abstract: We show that, in a Randall-Sundrum II type braneworld, the vacuum exterior of a spherical star is not in general a Schwarzschild spacetime, but has radiative-type stresses induced by five-dimensional graviton effects. Standard matching conditions do not lead to a unique exterior on the brane because of these five-dimensional graviton effects. We find an exact uniform-density stellar solution on the brane, and show that the general relativity upper bound $GM/Rl\frac{4}{9}$ is reduced by five-dimensional high-energy effects. The existence of neutron stars leads to a constraint on the brane tension that is stronger than the big bang nucleosynthesis constraint, but weaker than the Newton-law experimental constraint. We present two different non-Schwarzschild exteriors that match the uniform-density star on the brane, and we give a uniqueness conjecture for the full five-dimensional problem.
297 citations
TL;DR: The results of the study suggest that low levels of cypermethrin in the aquatic environment may have a significant effect on Atlantic salmon populations through disruption of reproductive functions.
228 citations
01 Jan 2001
220 citations
TL;DR: In this paper, the authors discuss the behaviour of an actual suspect while he was interviewed by the police in a murder case, and expose 65 police officers to six fragments (three truthful and three deceptive) of the interview with the murderer and ask them to indicate after each fragment whether the man was lying or not.
Abstract: All deception studies published to date have been laboratory studies. In such studies people lied only for the sake of the experiment, consequently the stakes were usually low. Although research has shown that most spontaneous lies told in real life are trivial, such studies tell us little about lies where the stakes are high (such as police/suspect interviews). In Study 1, we discuss the behaviour of an actual suspect while he was interviewed by the police in a murder case. Although the man initially denied knowing and killing the victim, substantial evidence obtained by the police showed that he was lying. On the basis of this evidence, the man confessed to killing the victim and was later convicted for murder. To our knowledge there has been no other study published that has analysed the behaviour of a liar in such a high-stake realistic setting. The analysis revealed several cues to deception. In Study 2, we exposed 65 police officers to six fragments (three truthful and three deceptive) of the interview with the murderer and asked them to indicate after each fragment whether the man was lying or not. The findings revealed that the participants were better at detecting truths (70% accuracy) than lies (57% accuracy). We also found individual differences among observers, with those holding popular stereotypical views on deceptive behaviour, such as ‘liars look away’ and ‘liars fidget’ performing least effectively as lie catchers.
218 citations
TL;DR: In this paper, a simple dynamic model dealing with the management of a marine renewable resource is presented, where instead of studying the ecological and economic interactions in terms of equilibrium or optimal control, the authors pay much attention to the viability of the system or, in a symmetric way, to crisis situations.
204 citations
TL;DR: In this paper, the amplitude of curvature perturbations on superhorizon scales, relative to their amplitude at horizon crossing, has been investigated in single-field inflation models, where the condition for a significant effect is that the quantity $a\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{\ensuremath{\varphi}}/H$ become sufficiently small, as compared to its value at horizon-crossing, for some time interval during inflation.
Abstract: We show that there exists a simple mechanism which can enhance the amplitude of curvature perturbations on superhorizon scales, relative to their amplitude at horizon crossing, even in some single-field inflation models. We give a criterion for this enhancement in general single-field inflation models; the condition for a significant effect is that the quantity $a\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{\ensuremath{\varphi}}/H$ become sufficiently small, as compared to its value at horizon crossing, for some time interval during inflation.
201 citations
TL;DR: The functional play of children with autism was compared to that of developmentally matched children with Down syndrome and typical infants, and a closer analysis of the composition of this play did reveal striking, qualitative differences.
Abstract: Research evidence indicates that children with autism may experience problems with functional play, in addition to their well-documented deficits in symbolic play. However, as a result of the tendency of previous studies to group all functional play into a single category, the precise nature and extent of this deficit remains unclear. The present study undertook a more refined analysis of such play, subtyping the functional acts into various categories, in terms of the developmental progression suggested by research with typical infants. The functional play of children with autism was compared to that of developmentally matched children with Down syndrome and typical infants. Although there were no group differences in overall measures of the proportion of total play time spent in functional play and in the number of functional acts performed, a closer analysis of the composition of this play did reveal striking, qualitative differences. The functional play of the autism group was less elaborated, less varied, and less integrated than that of the controls. The implications of these findings are explored in relation to current theoretical models of autism and in relation to the role of other people in mediating the appropriate use of objects.
188 citations
TL;DR: In this paper, the authors explore the nature of conflict and how institutional failure may be a primary cause of conflict over natural resources and propose a typology specific to tropical fishery conflicts.
162 citations
TL;DR: In this article, the authors examined the ability of fifty-two uniformed police officers to detect deception in a high-stake lies scenario, where the judges were exposed to videotaped press conferences of people who were asking the general public for help in finding their relatives or the murderers of their relatives.
Abstract: The present experiment examined the ability of fifty-two uniformed police officers to detect deception. The experiment differed from previous experiments into detecting deceit because of its high stake lies scenario. The judges were exposed to videotaped press conferences of people who were asking the general public for help in finding their relatives or the murderers of their relatives. They all lied during these press conferences and they all have been found guilty of killing their own relatives. The judges did not perform better than could be expected by chance. Additional analyses showed that accuracy was unrelated to confidence, age, years of job experience in the police force, or level of experience in interviewing suspects. There was, however, a significant positive correlation between having experience in interviewing suspects and being confident in detecting deception. Finally, men were better at detecting deception than women.
147 citations
TL;DR: The authors argue that traditional interpretations of research tend to bifurcate research knowledge and practice knowledge, with knowledge derived from practice and direct interaction with patients being perceived as knowledge that is not formally admissible by the traditional scientific model.
Abstract: Traditional interpretations of research tend to bifurcate research knowledge and practice knowledge, with knowledge derived from practice and direct interaction with patients being perceived as knowledge that is not formally admissible by the traditional scientific model. This paper proposes a research method that legitimises practice as a source of knowledge. Building upon the concepts of situational understanding and contingent knowledge, we advocate an integral research methodology, one which draws on the notion of the researcher-practitioner.Beginning with an analysis of knowledge and power we explore the contribution of reflexivity to the development of a politically and ethically engaged research process in nursing. In discussing critical reflexivity as a research method, we will outline the focus of reflexive research and the role of the reflexive researcher.Arguing against the superiority of theoretical research over practitioner research, we present a challenge to technical rationality, suggestin...
TL;DR: A no-go theorem is proved: the exterior spacetime on the brane cannot be static, which is in stark contrast with general relativity.
Abstract: (Received 3 August 2001; published 13 November 2001)We investigate how braneworld gravity affects gravitational collapse and black hole formation bystudying Oppenheimer-Snyder–like collapse on a Randall-Sundrum–type brane. Without making anyassumptions about the bulk, we prove a no-go theorem: the exterior spacetime on the brane cannot bestatic, which is in stark contrast with general relativity. We also consider the role of Kaluza-Klein energydensity in collapse, using a toy model.
TL;DR: The targeted acetylation of histones H3 and H4 at the GAPDH andCA genes is consistent with a role in transcriptional initiation and implies that transcriptional elongation does not necessarily require hyperacetylation.
TL;DR: In this article, an integrated framework combining a set of analytical tools within a multi-disciplinary holistic approach was used to identify the biological, economic, and social mechanisms which govern the fishermen's effort allocation between the two targeted stocks.
Abstract: In this paper we analyze the fishing effort allocation of fishermen in the artisanal fisheries of the Turks and Caicos Islands (British West Indies). These fishermen use a free-diving technique to simultaneously exploit the local stocks of queen conch and spiny lobster. Using an integrated framework combining a set of analytical tools within a multi-disciplinary holistic approach, we attempt to identify the biological, economic, and social mechanisms which govern the fishermen's effort allocation between the two targeted stocks. The analysis shows that the seasonal dynamics of the whole system are essentially dictated by the very remunerative lobster fishery. Although this result tends to espouse the predictions of classical economic theory, a closer analysis reveals that the economic rationality approach does not entirely explain the observed fishermen behavior. Information from a series of socio-anthropological surveys shows that the fishermen's decision making is further influenced by collective and individual constraints related to the specific diving abilities required to operate in the two fisheries and by the socio-historico-cultural environment within which the fishing community has been evolving over the last century.
TL;DR: Headspace solid-phase microextraction with Carboxen-polydimethylsiloxane fibres and gas chromatography-mass spectrometry for profiling urinary volatile components can complement profiling of non-volatile compounds in metabolic investigations and could be a useful extension of the diagnostic repertoire.
TL;DR: The authors examined the impact of public self-consciousness and acting ability on processes and stereotypical responses during deception and found that lying was positively correlated with trying to control behavior but negatively correlated with RM scores.
Abstract: This experiment examined the impact of public self-consciousness and acting ability on processes and stereotypical responses during deception. Seventy-three nursing students were videotaped while (a) telling the truth and (b) lying about a theft they had observed. A variety of cues were coded, including criteria-based content analysis (CBCA) and reality monitoring (RM), in which high scores indicated honest responding. Compared with truth tellers, liars waited longer before giving an answer, spoke faster, made more speech hesitations, showed fewer illustrators, and showed lower CBCA and RM scores. Public self-consciousness was positively correlated with trying to control behavior but negatively correlated with RM scores. Ability to act was negatively correlated with RM scores, with showing stereotypical deceptive facial behavior (gaze aversion and smiling), with having to think hard while lying, and with being nervous while lying.
TL;DR: The behavior of an anisotropic brane-world in the presence of inflationary scalar fields was examined in this article. But it was shown that a large initial anisotropy introduces more damping into the scalar field equation of motion, resulting in greater inflation.
Abstract: We examine the behavior of an anisotropic brane-world in the presence of inflationary scalar fields. We show that, contrary to naive expectations, a large anisotropy does not adversely affect inflation. On the contrary, a large initial anisotropy introduces more damping into the scalar field equation of motion, resulting in greater inflation. The rapid decay of anisotropy in the brane-world significantly increases the class of initial conditions from which the observed universe could have originated. This generalizes a similar result in general relativity. A unique feature of Blanchi type I brane-world cosmology appears to be that for scalar fields with a large kinetic term the initial expansion of the Universe is quasi-isotropic. The Universe grows more anisotropic during an intermediate transient regime until anisotropy finally disappears during inflationary expansion. ©2001 The American Physical Society.
TL;DR: It was concluded that synthesising poly(acrylic acid)s with better defined physicochemical properties than commercially available polymers will advance the study of the phenomenon of rheological synergy.
TL;DR: Although enjoying a period of renewed government policy interest and favourable research funding, youth studies has recently come under considerable intellectual attack, much of it from within this article, much of which comes from within.
Abstract: Although enjoying a period of renewed government policy interest and favourable research funding, youth studies has recently come under considerable intellectual attack, much of it from within. A c...
TL;DR: In this paper, the microscale of people and the macroscale of places are confounded in analyses, and this situation is usually tolerable, since most census data are released for spatial aggregates.
Abstract: Since most census data are released for spatial aggregates, the microscale of people and the macroscale of places are confounded in analyses. Although regrettable, this situation is usually tolerat...
TL;DR: In this article, the role of fatigue and oxidation in crack growth has been investigated at 650°C under typical loading waveforms at selected loading frequencies, and the results show that mixed time and cycle dependent crack growth seems to be the predominant crack growth mode in the two PM nickel alloys studied.
TL;DR: The authors investigated the question of China's regional per capita income convergence and found that China's regions, especially the eastern and the western regions, have converged to their own specific steady states over the past 40 years.
TL;DR: It is concluded that the new genus and species of coelurosaurian theropod dinosaur from the Wessex Formation of the Isle of Wight is one of the earliest and (with the exception of some teeth and an isolated ilium from Portugal) the first from Europe.
TL;DR: In this article, the cosmological dynamics of brane-world cosmologies with the Weyl tensor were studied, where the five-dimensional Wey tensor has a non-vanishing projection onto the three-brane, where matter fields are confined.
Abstract: In this paper we deal with the cosmological dynamics of Randall-Sundrum brane-world type scenarios in which the five-dimensional Weyl tensor has a nonvanishing projection onto the three-brane, where matter fields are confined. Using dynamical systems techniques, we study how the state space of Friedmann-Lema\^{\i}tre-Robertson-Walker and Bianchi type I cosmological models is affected by the bulk Weyl tensor, focusing on the differences that appear with respect to general relativity and also Randall-Sundrum cosmological scenarios without the Weyl tensor contribution.
TL;DR: Evaluation of the haemoglobin concentration and red blood cell count of women from Canada, Central America, China, and the United States shows that this situation is widespread, and women worldwide are at risk of being in a negative iron balance.
Abstract: The need to transport oxygen and remove carbon dioxide from animal tissue is a fundamental requirement of life, independent of age or sex.1 The role of iron in humans and many other mammals is central to this process. 2 3 Haemoglobin concentration and red blood cell count are important diagnostic indicators for anaemia in humans and animals.
In prepubertal humans no major differences can be found between the sexes in red blood cell count or haemoglobin and serum ferritin concentrations.4 Only after the onset of menstruation does a difference emerge.4 Not until 10 years after the menopause does this situation revert in women, when the haemoglobin concentration becomes similar to that of aged matched men. 4 5 This situation is compounded by the fact that modern women have a different reproductive history from those in the past. They reach sexual maturity at an earlier age, have fewer pregnancies, and breast feed for shorter periods; as such they menstruate for more years than women in the past. Menstruation is the principal cause of iron loss in women.6–8 Furthermore, 90% of UK females of childbearing age do not achieve the recommended daily intake of elemental iron (14.8 mg) from their diet.9 Evaluation of the haemoglobin concentration and red blood cell count of women from Canada, Central America, China, and the United States shows that this situation is widespread. 4 10–14 Women worldwide are at risk of being in a negative iron balance, and by current criteria if their haemoglobin concentration is less than 115 g/l they are deemed to be anaemic, whereas in men the cut-off point is 130 g/l.15
As far as the authors are aware, of the primates only humans show a sex difference in haemoglobin concentration and red blood …
TL;DR: The data suggest that glucocorticoid hormone action in skeletal muscle is determined principally by autoregulation of GRalpha, GRbeta, and 11betaHSD1 expression by the ligand-binding GRalpha isoform, and insulin and insulin-like growth factor I regulation of 11beta HSD1 may represent a novel mechanism that maintains insulin sensitivity in skeletal Muscle tissue by diminishing glucoc Corticoid antagonism of insulin action.
Abstract: Glucocorticoid excess frequently results in obesity, insulin resistance, glucose intolerance, and hypertension and may be the product of altered glucocorticoid hormone action. Tissue sensitivity to glucocorticoid is regulated by the expression of glucocorticoid receptor isoforms (GRalpha and GRbeta) and 11beta-hydroxysteroid dehydrogenase type I (11betaHSD1)-mediated intracellular synthesis of active cortisol from inactive cortisone. We have analyzed the expression of GRalpha, GRbeta, and 11betaHSD1 and their hormonal regulation in skeletal myoblasts from men (n = 14) with contrasting levels of adiposity and insulin resistance. Immunohistochemical, Northern blot, and Western blot analysis indicated abundant expression of GRalpha and 11betaHSD1 under basal conditions. The apparent K(m) and maximum velocity for the conversion of cortisone to cortisol were 440 +/- 14 nmol/L and 75 +/- 7 pmol/mg protein.h and 437 +/- 16 nmol/L and 33 +/- 6 pmol/mg protein.h (mean +/- SEM; n = 4) in the presence and absence of 20% serum. Incubation of myoblasts with increasing concentrations of glucocorticoid (50-1000 nmol/L) resulted in a dose-dependent decline in GRalpha expression and a dose-dependent increase in GRbeta expression. 11betaHSD1 activity was sensitively up-regulated by increasing concentrations of glucocorticoid (50-1000 nmol/L: P < 0.05). Abolition of these effects by the GR antagonist, RU38486, indicates that regulation of GRalpha, GRbeta, and 11betaHSD1 expression is mediated exclusively by the GRalpha ligand-binding variant. In contrast, 11betaHSD1 was down-regulated by insulin (20-100 mU/mL: P < 0.01) in the presence of 20% serum, whereas incubation with insulin under serum-free conditions resulted in a dose-dependent increase in 11betaHSD1 activity (P < 0.05). Incubation with insulin-like growth factor I resulted in a similar pattern of 11betaHSD1 activity. Although neither testosterone nor androstenedione (5-200 nmol/L) affected 11betaHSD1 activity, incubation of myoblasts with dehydroepiandrosterone (500 nmol/L) resulted in a decline in 11betaHSD1 activity (P < 0.05). These data suggest that glucocorticoid hormone action in skeletal muscle is determined principally by autoregulation of GRalpha, GRbeta, and 11betaHSD1 expression by the ligand-binding GRalpha isoform. Additionally, insulin and insulin-like growth factor I regulation of 11betaHSD1 may represent a novel mechanism that maintains insulin sensitivity in skeletal muscle tissue by diminishing glucocorticoid antagonism of insulin action.
TL;DR: There is a lack of independent analysis of the factors affecting the production strategies of private firms in the shrimp industry, and it is in the long-run self-interest of shrimp producers to incorporate the external costs of production into planning decisions.
TL;DR: Hsps are implicated as mediators of the innate activation by bacteria after the diffusion coefficient of CD14 remains unaffected after LPS ligation and that the diffusion coefficients of FITC-LPS and FITc-LTA bound to cells differ from that ofCD14.
Abstract: Although CD14 has been implicated in the immune recognition of bacterial lipopolysaccharide (LPS) from Gram-negative bacteria and also peptidoglycan (PGN) and lipoteichoic acid (LTA) from the outer cell wall of Gram-positive bacteria, accumulating evidence has suggested the possible existence of other functional receptor(s) In this study, we have used fluorescence recovery after photobleaching (FRAP) in order to get the first dynamic picture of the innate recognition of bacteria We have found that the diffusion coefficient of CD14 remains unaffected after LPS ligation and that the diffusion coefficients of FITC-LPS and FITC-LTA bound to cells differ from that of CD14 Furthermore, FITC-LPS/LTA rapidly become immobile when bound to cells, suggesting that FITC-LPS/LTA must briefly associate with CD14 in the initial attachment process and rapidly move on to an immobile receptor or to a complex of receptors Further FRAP experiments revealed that heat shock protein 70 (hsp70) and hsp90 are immobile in cell membranes, and antibodies against them were found to block the transfer of LPS to the immobile receptor and to inhibit interleukin 6 production upon LPS stimulation These experiments indicated that LPS transfers from CD14 to hsp70 and hsp90, which may be part of an LPS/LTA multimeric receptor complex Thus, hsps are implicated as mediators of the innate activation by bacteria
TL;DR: In this paper, a total of 39 police officers watched a videotape of a number of truth tellers and liars being interviewed, and participants were asked whether each of the people they saw on the videotape was lying or not.
Abstract: Purpose. The main aim of the experiment was to examine whether participants would be more accurate at detecting lies while using an indirect measure (i.e. ‘Does the person have to think hard?’) than while using a direct measure (‘Is the person lying?’). Method. A total of 39 police officers watched a videotape of a number of truth tellers and liars being interviewed. Participating police officers were randomly allocated to one of two experimental groups. In one condition, participants were asked whether each of the people they saw on the videotape was lying; in the other condition they had to indicate for each person whether that person ‘had to think hard’. Data were analysed in two ways: (1) the extent police officers could recognize lies and truths by using the two detection methods; and (2) behavioural and verbal cues the observers were actually looking for when answering the questions. Results. The results revealed that police officers could distinguish between truths and lies, but only by using the indirect method. Moreover, it was found that only by using the indirect method did they pay attention to the cues that were actual indicators of deceit. Conclusions. The findings suggest that the use of indirect methods might be useful for police officers when they attempt to detect deceit.
TL;DR: In this paper, the primordial black hole (PBH) production in the two-field preheating model with quadratic inflaton potential was studied and it was shown that for many values of the inflaton mass m, and coupling g, small scale perturbations will be amplified sufficiently, before back reaction can shut off pre-heating, so that PBHs will be overproduced during the subsequent radiation dominated era.
Abstract: During the preheating process at the end of inflation the amplification of field fluctuations can lead to the amplification of curvature perturbations. If the curvature perturbations on small scales are sufficiently large, primordial black holes (PBHs) will be overproduced. In this paper we study PBH production in the two-field preheating model with quadratic inflaton potential. We show that for many values of the inflaton mass m, and coupling g, small scale perturbations will be amplified sufficiently, before back reaction can shut off preheating, so that PBHs will be overproduced during the subsequent radiation dominated era.