Schistosome-induced portacaval haemodynamic changes in Rattus rattus are associated with translocation of adult worms to the lungs

The presence of naturally portacaval shunts has been investigated in the vasculature of normal and Schistosoma mansoni-infected Rattus rattus. Using the technique of injecting Polystyrene microspheres in the superior mesenteric vein, we demonstrated that the presence of adult schistosomes in the lungs of R. rattus was not due to an innate anomaly of the rat vasculature but resulted from the formation of portacaval shunts during infection. In rats harbouring a bisexual infection, microspheres were only detected in the lungs from week 7. The development and increasing size of the shunts were maximal between weeks 7 and 10 and coincident with the translocation of adult worms from the portal tract to the lungs. At weeks 20–25, only 1–2% of the microspheres were recovered from the lungs, suggesting that the portacaval anastomoses have regressed due to reduction in portal hypertension after worm translocation. R. rattus with a male-only schistosome infection harboured adult worms in the lungs, indicating that the development of shunts does not solely depend upon egg deposition in the liver to generate hypertension. The relationships between the presence of the schistosomes in the lungs, the portacaval shunting and the resistance to reinfection is discussed

Active clearance control system for a turbomachine

An axial compressor is provided with a cooling air manifold surrounding a portion of the shroud, and means for bleeding air from the compressor to the manifold for selectively flowing it in a modulating manner axially along the outer side of the stator/shroud to cool and shrink it during steady state operating conditions so as to obtain minimum shroud/rotor clearance conditions. Provision is also made to selectively divert the flow of cooling air from the manifold during transient periods of operation so as to alter the thermal growth or shrink rate of the stator/shroud and result in adequate clearance with the compressor rotor

The relationship between alexithymia and self-harm: the mediating role of mindfulness

Objectives. Self-harm, defined as any act of self-injury, irrespective of motivation, is a phenomenon which can have serious consequences for the individual, as well as significant public health costs. Many correlational studies have established a significant association between self-harm and alexithymia, a cognitive deficit in emotion processing, characterised by a difficulty identifying and describing feelings and an externally orientated thinking style. The current study investigated whether this relationship is explained by low levels of dispositional mindfulness. Methods. An opportunity sample of 325 community-based adults completed an online survey measuring their history of self-harm, alexithymia (Toronto Alexithymia Scale) and mindfulness (Five Facets of Mindfulness Questionnaire). Results. Alexithymia was significantly higher among participants with a history of self-harm, compared with participants with no history of self-harm. All mindfulness facets were significantly lower among participants with a history of self-harm except the facet Observe which was significantly higher in that group. A multiple mediation analysis found that the mindfulness facets Non-judge and Non-react were positive, significant mediators of the relationship between alexithymia and self-harm, but the facet Observe suppressed the relationship. Conclusions. The relationship between alexithymia and self-harm can be explained in part by deficits in mindfulness skills, particularly the ability to accept emotional experience without judgment or reaction. Conversely, the external orientation of alexithymia may itself be protective against self-harm, through the avoidance of excessive introspection. Thus, merely learning to observe inner experience, without the ability to understand and accept that experience, may have adverse consequences

"My heart and my brain is what's bleeding, these are just cuts." An interpretative phenomenological analysis of young women's experiences of self-harm

Engagement in self-harm, defined as intentional self-poisoning or self-injury irrespective of the apparent purpose of the act, is increasing, particularly among girls and young women. Understanding the behavior from the perspective of those who self-harm is, therefore, vital in designing effective interventions and treatments. The current brief research report presents a key theme from an Interpretative Phenomenological Analysis of the experience of self-harm among eight young women, aged between 18 and 29. The theme Is Self-Harm Bad? concerns the way in which participants both acknowledged and resisted a negative conception of self-harm that was often constructed from other people's attitudes. Three subthemes explore the reasons why participants were reluctant to endorse self-harm as bad: Self-Harm is the Symptom, Self-Harm Works (Until it Doesn't) and Self-Harm is Part of Me. The findings highlight the disparity between the characterization of self-harm as a highly risky behavior and the lived experience of self-harm as a functional means of emotion regulation. From a clinical perspective, the findings explored in this brief report suggest that highlighting the risks of self-harm may not be a sufficient deterrent. The recently revised draft National Institute for Health and Care Excellence (NICE) guidance recommends that everyone presenting to hospital following self-harm should be given a comprehensive psychosocial assessment, of which the function is, in part, to understand why the person has self-harmed. The current study underlines the importance of seeing past the behavior to the underlying causes and exploring the meaning of self-harm to the individual in order to implement effective preventative interventions

“I can’t describe it and they can’t see the rain.” an interpretative phenomenological analysis of the experience of self-harm in young adults who report difficulties identifying and describing their feelings.

Self-harm is a serious and increasing public health concern. Self-harm is significantly associated with alexithymia, a trait characterised by a difficulty identifying and describing feelings. Alexithymia has been found to be a barrier to psychological treatment. This article explores the experiences of self-harm among eight young adults who reported difficulties identifying and describing their feelings. Semi-structured interviews were conducted, with the optional use of photographs as visual stimuli for discussion. Transcripts were analysed using Interpretative Phenomenological Analysis. Two themes are presented here: The Obscure Self describes participants’ struggle to grasp a coherent sense of self, and how self-harm provided a means of physically reconnecting with their bodies. Words Fail Me describes participants’ difficulties communicating their subjective experience, which increased feelings of isolation and recourse to self-harm. There were also tentative indications that participants were able to recognise their emotional experience when expressed by others. The lack of interpersonal connection, arising from difficulties understanding feelings and communicating them to others, may create or exacerbate the context for self-harm. The findings have relevance for the treatment of self-harm, given the high, but often unacknowledged, prevalence of alexithymia in clinical populations

Effects of mindfulness-based interventions on alexithymia: a systematic review

Question: Alexithymia has been found to be modifiable through treatment, with associated clinical benefits. Recent studies have begun to test the potential of mindfulness-based interventions to reduce alexithymia, using skills-based, group training to improve non-judgmental, present moment awareness. The objective of this review therefore was to conduct a systematic synthesis to assess the current state of knowledge about the effect of mindfulness-based interventions on alexithymia to inform clinical practice. Study Selection and Analysis: We carried out a systematic review of the literature and found four randomised controlled trials of the effect of mindfulness-based interventions on alexithymia, with a combined total of 460 participants. Findings: A random effects meta-analysis, combining study endpoint data, showed a statistically significant effect of mindfulness-based treatment on alexithymia, (Toronto Alexithymia Scale [TAS20]) compared with the control group (mean difference = -5.28, 95% CI -9.28 to -1.28, p=0.010). Subgroup analysis was conducted to investigate sources of heterogeneity (I2=52%). Heterogeneity was reduced when the meta-analysis was restricted to interventions of a similar duration (three months or less). Conclusions: Findings from our study should be replicated in further research with larger samples; however, the results indicate that mindfulness-based interventions may be an effective treatment in reducing alexithymia

The relationship between self-harm and alexithymia: a systematic review and meta-analysis

Self-harm, defined for the purpose of this review as any act of self-injury without explicit suicidal intent, is an increasing public health concern, with potential long-term implications for those who engage in it. Previous research has identified a correlational relationship between self-harm and alexithymia, an emotion processing deficit characterised by difficulties identifying and describing feelings, and an externally-orientated thinking style. Through a systematic search of the literature, the current review examines the association between alexithymia and self-harm. A meta-analysis based on 23 studies found a significant, positive relationship between self-harm and alexithymia, with a medium effect size (g = 0.57, 95% CI 0.45 to 0.71). All 23 studies used the Toronto Alexithymia Scale (TAS20) to measure alexithymia. The alexithymia subcomponents difficulty identifying feelings and difficulty describing feelings were significantly associated with self-harm, but there was no significant association between self-harm and externally-orientated thinking. The effect size of the relationship was significantly larger in adolescent samples compared with adult samples and in female compared with male samples. The definition of self-harm did not affect the effect size of the relationship between alexithymia and self-harm and the results are consistent with previous meta-analyses focused more narrowly on non-suicidal self-injury and, separately, suicidal behaviours. Heterogeneity between the included studies was high. The results support an affect regulation model of self-harm, in which self-harm is used to regulate an emotional experience that is poorly understood

Effect of quantum nuclear motion on hydrogen bonding

This work considers how the properties of hydrogen bonded complexes, D-H....A, are modified by the quantum motion of the shared proton. Using a simple two-diabatic state model Hamiltonian, the analysis of the symmetric case, where the donor (D) and acceptor (A) have the same proton affinity, is carried out. For quantitative comparisons, a parametrization specific to the O-H....O complexes is used. The vibrational energy levels of the one-dimensional ground state adiabatic potential of the model are used to make quantitative comparisons with a vast body of condensed phase data, spanning a donor-acceptor separation (R) range of about 2.4-3.0 A, i.e., from strong to weak bonds. The position of the proton and its longitudinal vibrational frequency, along with the isotope effects in both are discussed. An analysis of the secondary geometric isotope effects, using a simple extension of the two-state model, yields an improved agreement of the predicted variation with R of frequency isotope effects. The role of the bending modes in also considered: their quantum effects compete with those of the stretching mode for certain ranges of H-bond strengths. In spite of the economy in the parametrization of the model used, it offers key insights into the defining features of H-bonds, and semi-quantitatively captures several experimental trends.Comment: 12 pages, 8 figures. Notation clarified. Revised figure including the effect of bending vibrations on secondary geometric isotope effect. Final version, accepted for publication in Journal of Chemical Physic

Estimating the functional form for the density dependence from life history data

Two contrasting approaches to the analysis of population dynamics are currently popular: demographic approaches where the associations between demographic rates and statistics summarizing the population dynamics are identified; and time series approaches where the associations between population dynamics, population density, and environmental covariates are investigated. In this paper, we develop an approach to combine these methods and apply it to detailed data from Soay sheep (Ovis aries). We examine how density dependence and climate contribute to fluctuations in population size via age- and sex-specific demographic rates, and how fluctuations in demographic structure influence population dynamics. Density dependence contributes most, followed by climatic variation, age structure fluctuations and interactions between density and climate. We then simplify the density-dependent, stochastic, age-structured demographic model and derive a new phenomenological time series which captures the dynamics better than previously selected functions. The simple method we develop has potential to provide substantial insight into the relative contributions of population and individual-level processes to the dynamics of populations in stochastic environments

Effects of electromagnetic fields emitted by GSM phones on working memory: a meta-analysis

Background and Objective: Current treatments for Alzheimer's Disease (AD) do not affect the course of the illness and brain stimulation techniques are increasingly promoted as potential therapeutic inter-ventions for AD. This study reviews the effects of electromagnetic field (EMF) exposure versus sham exposure on working memory (WM) performance of healthy human participants. Method: Online literature databases and previous systematic reviews were searched for studies of EMF and WM in participants without reported memory problems. Two thousand eight hundred and fifty seven studies were identified, and 10 studies met the inclusion criteria. An assessment of study quality was completed, and separate, random effects meta-analyses were conducted for each of the three WM tasks included: n-back, substitution and digit span forward. Results: No differences were found between participants exposed to active EMF versus sham conditions in any of the three working memory tasks examined. Conclusion: Results indicate that EMF does not affect WM during the n-back, substitution and digit-span tasks. Future studies should focus on the possible effects of chronic exposure to EMF in older adults with AD using a battery of comparable WM and attention tasks, before EMF can be seriously considered as a potential modulator of WM in AD