1,251 research outputs found

    KULTUR: showcasing art through institutional repositories

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    Showcasing work has always been at the heart of the arts community, whether it be through an exhibition, site-specific installation or performance. Representation of the original work has also been important and use of print-based options like exhibition catalogues is now complemented by websites and multi-media friendly services like Flickr and YouTube and Vimeo. These services also provide options for sharing born-digital material. For those working in higher education there is a need to profile both the personal and the institutional aspects of creative outputs. The KULTUR project created a model for arts-based institutional repositories and it is hoped that this approach will be useful for other arts institutions

    Perioperative use of oxygen: variabilities across age

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    Enormous interest has emerged in the perioperative use of high concentrations of inspired oxygen in an attempt to increase tissue oxygenation and thereby improve postoperative outcome. An extensive debate has arisen regarding the risk/benefit ratio of oxygen therapy, with some researchers advocating the benefits of perioperative hyperoxia, particularly with regard to surgical site infection, whereas others emphasize its detrimental consequences on multiple organs, particularly the lungs and the brain. As one aspect of this debate, there is increased awareness of effects of reactive oxygen metabolites, a feature that contributes to the complexity of achieving consensus regarding optimum oxygen concentration in the perioperative period. Many reviews have discussed the pros and cons in the use of perioperative oxygen supplementation, but the potential importance of age-related factors in hyperoxia has not been addressed. The present narrative review provides a comprehensive overview of the physiological mechanisms and clinical outcomes across the age range from neonates to the elderly. Risks greatly outweigh the benefits of hyperoxia both in the very young, where growth and development are the hallmarks, and in the elderly, where ageing increases sensitivity to oxidative stress. Conversely, in middle age, benefits of short-term administration of perioperative oxygen therapy exceed potential adverse change effects, and thus, oxygen supplementation can be considered an important therapy to improve anaesthesia managemen

    Perioperative factor concentrate therapy

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    Transfusion of allogeneic plasma has been a life-saving measure for decades in patients with severe trauma or suffering from major surgical blood loss. The safety of allogeneic blood components has improved in terms of pathogen transmission, but haemostatic efficacy of plasma is hindered by the large volume and time required for thawing and infusion. Several plasma-derived and recombinant factor concentrates are clinically available and indicated for targeted replacement of missing coagulation elements in hereditary disorders of thrombosis and haemostasis. When used appropriately, factor concentrate therapy can rapidly restore deficient factor(s) without causing volume overload. The haemostatic defect in perioperative patients is often multifactorial, and therefore careful clinical judgement and timely coagulation testing must be exercised before the administration of factor concentrates. In this review, the rationale for including factor concentrates in perioperative haemostatic management will be discussed in conjunction with the limitations of plasma transfusio

    Glycaemic control in the perioperative period

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    The prevalence of type 2 diabetes mellitus and the potential for perioperative dysglycaemia (hyperglycaemia, hypoglycaemia, stress-induced hyperglycaemia, or glucose variability) continue to increase dramatically. The majority of investigations on perioperative glycaemic control focused on critically ill patients and concentrated on goals of therapy, level of intensity of insulin infusion, feeding regimes, concerns over hypoglycaemia, and promulgation of recent guidelines calling for less strict glucose control. Areas of perioperative glycaemic control that deserve further investigation include preoperative identification of patients with undiagnosed type 2 diabetes and other forms of dysglycaemia, determination of appropriate intraoperative glucose goals, and establishment of the impact and natural history of perioperative abnormalities in glucose homeostasis. In the heterogeneous adult perioperative population, it is unlikely that one standard of perioperative glycaemic control is appropriate for all patients. This review presents recent evidence and expert guidance to aid preoperative assessment, intraoperative management, and postoperative care of the dysglycaemic adult patien

    General anaesthetics do not impair developmental expression of the KCC2 potassium-chloride cotransporter in neonatal rats during the brain growth spurt

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    Background The developmental transition from depolarizing to hyperpolarizing Ī³-aminobutyric acid-mediated neurotransmission is primarily mediated by an increase in the amount of the potassium-chloride cotransporter KCC2 during early postnatal life. However, it is not known whether early neuronal activity plays a modulatory role in the expression of total KCC2 mRNA and protein in the immature brain. As general anaesthetics are powerful modulators of neuronal activity, the purpose of this study was to explore how these drugs affect KCC2 expression during the brain growth spurt. Methods Wistar rat pups were exposed to either a single dose or 6 h of midazolam, propofol, or ketamine anaesthesia at postnatal days 0, 5, 10, or 15. KCC2 expression was assessed using immunoblotting, immunohistochemistry, or quantitative polymerase chain reaction analysis up to 3 days post-exposure in the medial prefrontal cortex. Results There was a progressive and steep increase in the expression of KCC2 between birth and 2 weeks of age. Exposure to midazolam, propofol, or ketamine up to 6 h at any investigated stages of the brain growth spurt did not influence the expression of this cotransporter protein. Conclusion I.V. general anaesthetics do not seem to influence developmental expression of KCC2 during the brain growth spur

    Sodium Channels as Targets for Volatile Anesthetics

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    The molecular mechanisms of modern inhaled anesthetics are still poorly understood although they are widely used in clinical settings. Considerable evidence supports effects on membrane proteins including ligand- and voltage-gated ion channels of excitable cells. Na+ channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetic effects on central nervous system depression. Inhibition of presynaptic Na+ channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic end points: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na+ currents by volatile anesthetics at high concentrations. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na+ channel isoforms implicated inhibition of presynaptic Na+ channels in anesthetic actions at clinical concentrations. Volatile anesthetics reduce peak Na+ current (INa) and shift the voltage of half-maximal steady-state inactivation (hāˆž) toward more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed, together with enhanced use-dependent block during pulse train protocols. These effects can depress presynaptic excitability, depolarization and Ca2+ entry, and ultimately reduce transmitter release. This reduction in transmitter release is more potent for glutamatergic compared to GABAergic terminals. Involvement of Na+ channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na+ channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na+ channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na+ channels by volatile anesthetics is involved in mediating some of their effects

    Long sperm fertilize more eggs in a bird

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    Sperm competition, in which the ejaculates of multiple males compete to fertilize a female's ova, results in strong selection on sperm traits. Although sperm size and swimming velocity are known to independently affect fertilization success in certain species, exploring the relationship between sperm length, swimming velocity and fertilization success still remains a challenge. Here, we use the zebra finch (Taeniopygia guttata), where sperm size influences sperm swimming velocity, to determine the effect of sperm total length on fertilization success. Sperm competition experiments, in which pairs of males whose sperm differed only in length and swimming speed, revealed that males producing long sperm were more successful in terms of (i) the number of sperm reaching the ova and (ii) fertilizing those ova. Our results reveal that although sperm length is the main factor determining the outcome of sperm competition, complex interactions between male and female reproductive traits may also be important. The mechanisms underlying these interactions are poorly understood, but we suggest that differences in sperm storage and utilization by females may contribute to the outcome of sperm competition

    ā€˜I donā€™t know what gender is, but I do, and I can, and we all doā€™: an interview with Clare Hemmings

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    What follows is an interview with Clare Hemmings, Professor of Feminist Theory and Head of the Department of Gender Studies at the London School of Economics. A leading figure in UK feminist theory, her research insists that we acknowledge matters of ambivalence and uncertainty in our history-making, storytelling and theorising. As such, it contributes to and has productively intervened in many fields, including feminist epistemology, affect theory, historiography and sexuality studies. Beginning with her first book, Bisexual Spaces: A Geography of Sexuality and Gender (2002), continuing in Why Stories Matter: The Political Grammar of Feminist Theory (2011), and most overtly in Considering Emma Goldman: Feminist Political Ambivalence and the Imaginative Archive (2018), Hemmings interrogates and challenges dominant modes and expressions of gender and sexuality from a feminist positionality that is itself under-theorised and rarely articulated: that of a feminine bisexual woman. As Hemmings notes, bisexual positionality encompasses the affective capacity for a ā€˜combination of heterosexual and homosexual desireā€™ (Hemmings, 2002a; 2002b: 17) and thus generates ā€˜radical reconfigurationsā€™ (Hemmings, 2002b: 197) of our understanding of the relations between gender, sex and desire. Yet bisexuality has been repeatedly reproduced, within both feminist and queer theory, ā€˜as an abstract and curiously lifeless middle. As a lesbian and feminist who has occupied that supposedly ā€˜lifeless middle groundā€™, albeit differently (I have had two long-term relationships, one with a man, one with a woman), I was interested in speaking with Clare about these issues, and was compelled to do so after I attended an event that she co-organised at the London School of Economics, a screening of Sylvie Tissotā€™s film about the French feminist Christine Delphy that included Delphy herself. As soon as Delphy entered the theatre and began walking down the stairs to the podium, the audience burst spontaneously into a standing ovation and long applause: '[T]his moment involved both a shared jouissance and the returning of haunting conflicts within feminism ā€“ conflicts that we wish had been resolved long ago ā€“because it entailed both exhilarating and dissonant affects, it became a sort of feminist moment par excellence, a moment where solidarity is never exempted from the (re)emergence of disagreements, and where the fantasy of a collective fusion becomes the condition for those conflicts to emerge' (Eloit in Delphy et al., 2016: 151). Delphyā€™s presence, and the film about her, reminded me that (1) feminist thinkers from the 1970s and 1980s were extraordinarily sophisticated in their understanding of how gender constitutes us as men and women; (2) this analysis is still mostly absent from public conversations; and (3) we still long for such conversations. My interview with Clare Hemmings is thus a continuation of this moment of shared jouissance and haunting. It was conducted informally, in 2017, in Clareā€™s office, in what was then the Gender Institute, in Columbia House at the LSE. For over 90 minutes during a grey afternoon in London, we spoke on a range of topics, from Clareā€™s intellectual history to her (then) forthcoming book on Emma Goldman. We discussed her background as a poststructuralist theorist who also carries out empirical research and the challenge of studying sexuality in the archive. In the portion of the interview that appears below, we talk in detail about Clareā€™s early work on bisexuality and how her thinking contributes to theorising gender in the present
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