106 research outputs found

    [Photodissociation of Acetylene and Acetone using Step-Scan Time-Resolved FTIR Emission Spectroscopy]

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    The photodissociation of acetylene and acetone was investigated as a function of added quenching gas pressures using step-scan time-resolved FTIR emission spectroscopy. Its main components consist of Bruker IFS88, step-scan Fourier Transform Infrared (FTIR) spectrometer coupled to a flow cell equipped with Welsh collection optics. Vibrationally excited C2H radicals were produced from the photodissociation of acetylene in the unfocused experiments. The infrared (IR) emission from these excited C2H radicals was investigated as a function of added argon pressure. Argon quenching rate constants for all C2H emission bands are of the order of 10(exp -13)cc/molecule.sec. Quenching of these radicals by acetylene is efficient, with a rate constant in the range of 10(exp -11) cc/molecule.sec. The relative intensity of the different C2H emission bands did not change with the increasing argon or acetylene pressure. However, the overall IR emission intensity decreased, for example, by more than 50% when the argon partial pressure was raised from 0.2 to 2 Torr at fixed precursor pressure of 160mTorr. These observations provide evidence for the formation of a metastable C2H2 species, which are collisionally quenched by argon or acetylene. Problems encountered in the course of the experimental work are also described

    Banishing the control homunculi in studies of action control and behaviour change

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    types: ReviewDOI and citation will be added to the record once they are known.© 2014 Association for Psychological ScienceFor centuries, human self-control has fascinated scientists and nonscientists alike. Current theories often attribute it to an executive control system. But even though executive control receives a great deal of attention across disciplines, most aspects of it are still poorly understood. Many theories rely on an ill-defined set of ‘homunculi’ doing jobs like 'response inhibition' or ‘updating’ without explaining how they do so. Furthermore, it is not always appreciated that control takes place across different time-scales. These two issues hamper major advances. Here we focus on the mechanistic basis for the executive control of actions. We propose that at the most basic level, action control depends on three cognitive processes: signal detection, action selection, and action execution. These processes are modulated via error-correction or outcome-evaluation mechanisms, preparation, and task rules maintained in working- and long-term memory. We also consider how executive control of actions becomes automatised with practice, and how people develop a control network. Finally, we discuss how the application of this unified framework in clinical domains can increase our understanding of control deficits and provide a theoretical basis for the development of novel ‘behavioural change’ interventions

    Perceptual learning and inversion effects: Recognition of prototype-defined familiar checkerboards.

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    PublishedJournal ArticleResearch Support, Non-U.S. Gov'tThe face inversion effect is a defection in performance in recognizing inverted faces compared with faces presented in their usual upright orientation typically believed to be specific for facial stimuli. McLaren (1997) was able to demonstrate that (a) an inversion effect could be obtained with exemplars drawn from a familiar category, such that upright exemplars were better discriminated than inverted exemplars; and (b) that the inversion effect required that the familiar category be prototype-defined. In this article, we replicate and extend these findings. We show that the inversion effect can be obtained in a standard old/new recognition memory paradigm, demonstrate that it is contingent on familiarization with a prototype-defined category, and establish that the effect is made up of two components. We confirm the advantage for upright exemplars drawn from a familiar, prototype-defined category, and show that there is a disadvantage for inverted exemplars drawn from this category relative to suitable controls. We also provide evidence that there is an N170 event-related potential signature for this effect. These results allow us to integrate a theory of perceptual learning originally proposed by McLaren, Kaye, and Mackintosh (1989) with explanations of the face inversion effect, first reported by Yin.University of ExeterNational Key Fundamental Research (973) Progra

    How does response inhibition influence decision-making when gambling? (dataset)

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    Behavioural data, skin-conductance data, eye movement data, and R scripts (analyses) for eight behavioural experiments.Dataset relating to 'How does response inhibition influence decision-making when gambling?’research paper published in the Journal of Experimental Psychology: Applied. The paper is available in ORE: http://hdl.handle.net/10871/15841Behavioural data, skin-conductance data, eye movement data, and R scripts (analyses) for eight behavioural experiments. Experiment documentation is included as well.​ This data is related to the article 'How does response inhibition influence decision-making when gambling?' published in Journal of Experimental Psychology: Applied.Economic and Social Research Council (ESRC)European Research Council (ERC)Biotechnology and Biological Sciences Research Council (BBSRC)British Academy/Leverhulme Gran

    A core outcome set for localised prostate cancer effectiveness trials

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    Objective: To develop a core outcome set (COS) applicable for effectiveness trials of all interventions for localised prostate cancer. Background: Many treatments exist for localised prostate cancer, although it is unclear which offers the optimal therapeutic ratio. This is confounded by inconsistencies in the selection, definition, measurement and reporting of outcomes in clinical trials. Subjects and methods: A list of 79 outcomes was derived from a systematic review of published localised prostate cancer effectiveness studies and semi-structured interviews with 15 prostate cancer patients. A two-stage consensus process involving 118 patients and 56 international healthcare professionals (HCPs) (cancer specialist nurses, urological surgeons and oncologists) was undertaken, consisting of a three-round Delphi survey followed by a face-to-face consensus panel meeting of 13 HCPs and 8 patients. Results: The final COS included 19 outcomes. Twelve apply to all interventions: death from prostate cancer, death from any cause, local disease recurrence, distant disease recurrence/metastases, disease progression, need for salvage therapy, overall quality of life, stress urinary incontinence, urinary function, bowel function, faecal incontinence, sexual function. Seven were intervention-specific: perioperative deaths (surgery), positive surgical margin (surgery), thromboembolic disease (surgery), bothersome or symptomatic urethral or anastomotic stricture (surgery), need for curative treatment (active surveillance), treatment failure (ablative therapy), and side effects of hormonal therapy (hormone therapy). The UK-centric participants may limit the generalisability to other countries, but trialists should reason why the COS would not be applicable. The default position should not be that a COS developed in one country will automatically not be applicable elsewhere. Conclusion: We have established a COS for trials of effectiveness in localised prostate cancer, applicable across all interventions which should be measured in all localised prostate cancer effectiveness trials

    Histories of forced sex and health outcomes among Southern African lesbian and bisexual women: a cross-sectional study

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    BACKGROUND: Experiences of forced sex have been shown to be prevalent in Southern Africa. Negative outcomes of forced sex have been documented in general populations of women and men and include alcohol abuse, drug use, mental health problems, mental distress, sexual health problems and poor overall health. This study is the first to examine experiences of forced sex and associated health problems among lesbian and bisexual women in Southern Africa. METHODS: This study is based on data collected as part of a collaborative endeavor involving various Southern African community-based organizations. Lesbian and bisexual women in four Southern African countries participated in a cross-sectional survey, for a total study sample of 591. RESULTS: Nearly one-third of participants had been forced to have sex at some time in their lives. Thirty-one percent of all women reported to have experienced forced sex at least once in their life: 14.9% reported forced sex by men only; 6.6% reported forced sex by women only; 9.6% had had forced sexual experiences with both men and women. Participants experienced forced sex by men as more serious than forced sex by women; forced sex by women was more likely to involve intimate partners compared to forced sex by men. Participants who experienced forced sex by men were more likely to report drug problems, mental distress and lower sense of belonging. Forced sex by women was associated with drinking problems and mental distress. Having experienced forced sex by both men and women was associated with lower sense of belonging to the LGBT community, drug use problem and mental distress. CONCLUSIONS: The findings indicate that forced sex among Southern African women is a serious issue that needs further exploration. Clinicians should be made aware of the prevalence and possible consequences of forced sex among lesbian and bisexual women. Policies and community interventions should be designed to address this problem

    A double-blind, randomized, placebo-controlled trial of prostaglandin E 1 in liver transplantation

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    A double-blind placebo-controlled trial of intravenous prostaglandin PGE 1 (40 Μg/h) was conducted in adult orthotopic liver transplant recipients. Infusion was started intraoperatively and continued for up to 21 days. Patients were followed up for 180 days postoperatively. Among 172 patients eligible for treatment in the study, 160 could be evaluated (78 PGE 1 ; 82 placebo). Patient and graft survival were similar (PGE 1 : 16 deaths, 9 retransplantations [7 survivors]; controls: 15 deaths, 6 retransplantations [3 survivors]). In patients with surviving grafts, however, PGE 1 administration resulted in a 23% shorter mean duration of hospitalization following transplantation (PGE 1 : 24.4 days; controls: 31.8 days; P = .02) and 40% shorter length of time postoperatively in the intensive care unit (PGE 1 : 8.2 days; controls 13.7 days; P = .05). Reduced needs for renal support ( P = .03) or surgical intervention other than retransplantation ( P = .02) were also noted with PGE 1 use. Further, PGE 1 administration resulted in a trend toward improved survival rates in patients with mild renal impairment (preoperative serum creatinine 1.5 mg percent or greater; P = .08). Neither the incidence of acute cellular rejection nor of primary nonfunction was significantly different in the two groups. Phlebitis was the only complication that was more common during PGE 1 administration, (PGE 1 : 9; controls: 4). These results suggest that PGE 1 use in hepatic allograft recipients reduces morbidity and may result in sizable cost reductions. (H EPATOLOGY 1995;21:366–372.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38409/1/1840210216_ftp.pd

    Cyborgs in the everyday:Masculinity and biosensing prostate cancer

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    An in vivo biosensor is a technology in development that will assess the biological activity of cancers to individualise external beam radiotherapy. Inserting such technology into the human body creates cybernetic organisms; a cyborg that is a human–machine hybrid. There is a gap in knowledge relating to patient willingness to allow automated technology to be embedded and to become cyborg. There is little agreement around what makes a cyborg and less understanding of the variation in the cyborgisation process. Understanding the viewpoint of possible beneficiaries addresses such gaps. There are currently three versions of ‘cyborg’ in the literature (i) a critical feminist STS concept to destabilise power inherent in dualisms, (ii) an extreme version of the human/machine in science-fiction that emphasises the ‘man’ in human and (iii) a prediction of internal physiological adaptation required for future space exploration. Interview study findings with 12 men in remission from prostate cancer show a fourth version can be used to describe current and future sub-groups of the population; ‘everyday cyborgs'. For the everyday cyborg the masculine cyborg status found in the fictionalised human–machine related to issues of control of the cancer. This was preferred to the felt stigmatisation of being a ‘leaker and bleeder’. The willingness to become cyborg was matched with a having to get used to the everyday cyborg's technological adaptations and risks. It is crucial to explore the everyday cyborg's sometimes ambivalent viewpoint. The everyday cyborg thus adds the dimension of participant voice currently missing in existing cyborg literatures and imaginations

    Mutational processes molding the genomes of 21 breast cancers

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    All cancers carry somatic mutations. The patterns of mutation in cancer genomes reflect the DNA damage and repair processes to which cancer cells and their precursors have been exposed. To explore these mechanisms further, we generated catalogs of somatic mutation from 21 breast cancers and applied mathematical methods to extract mutational signatures of the underlying processes. Multiple distinct single- and double-nucleotide substitution signatures were discernible. Cancers with BRCA1 or BRCA2 mutations exhibited a characteristic combination of substitution mutation signatures and a distinctive profile of deletions. Complex relationships between somatic mutation prevalence and transcription were detected. A remarkable phenomenon of localized hypermutation, termed "kataegis," was observed. Regions of kataegis differed between cancers but usually colocalized with somatic rearrangements. Base substitutions in these regions were almost exclusively of cytosine at TpC dinucleotides. The mechanisms underlying most of these mutational signatures are unknown. However, a role for the APOBEC family of cytidine deaminases is proposed
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