A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL) and Blood Oxygenation Level Dependent (BOLD) imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO(2)) that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP) estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged

Visual search in ecological and non-ecological displays: Evidence for a non-monotonic effect of complexity on performance

Copyright @ 2013 PLoSThis article has been made available through the Brunel Open Access Publishing Fund.Considerable research has been carried out on visual search, with single or multiple targets. However, most studies have used artificial stimuli with low ecological validity. In addition, little is known about the effects of target complexity and expertise in visual search. Here, we investigate visual search in three conditions of complexity (detecting a king, detecting a check, and detecting a checkmate) with chess players of two levels of expertise (novices and club players). Results show that the influence of target complexity depends on level of structure of the visual display. Different functional relationships were found between artificial (random chess positions) and ecologically valid (game positions) stimuli: With artificial, but not with ecologically valid stimuli, a “pop out” effect was present when a target was visually more complex than distractors but could be captured by a memory chunk. This suggests that caution should be exercised when generalising from experiments using artificial stimuli with low ecological validity to real-life stimuli.This study is funded by Brunel University and the article is made available through the Brunel Open Access Publishing Fund

How does uncertainty shape patient experience in advanced illness? A secondary analysis of qualitative data.

BACKGROUND: Uncertainty is common in advanced illness but is infrequently studied in this context. If poorly addressed, uncertainty can lead to adverse patient outcomes. AIM: We aimed to understand patient experiences of uncertainty in advanced illness and develop a typology of patients' responses and preferences to inform practice. DESIGN: Secondary analysis of qualitative interview transcripts. Studies were assessed for inclusion and interviews were sampled using maximum-variation sampling. Analysis used a thematic approach with 10% of coding cross-checked to enhance reliability. SETTING/PARTICIPANTS: Qualitative interviews from six studies including patients with heart failure, chronic obstructive pulmonary disease, renal disease, cancer and liver failure. RESULTS: A total of 30 transcripts were analysed. Median age was 75 (range, 43-95), 12 patients were women. The impact of uncertainty was frequently discussed: the main related themes were engagement with illness, information needs, patient priorities and the period of time that patients mainly focused their attention on (temporal focus). A typology of patient responses to uncertainty was developed from these themes. CONCLUSION: Uncertainty influences patient experience in advanced illness through affecting patients' information needs, preferences and future priorities for care. Our typology aids understanding of how patients with advanced illness respond to uncertainty. Assessment of these three factors may be a useful starting point to guide clinical assessment and shared decision making.Simon Noah Etkind is funded as an Academic Clinical Fellow by the National Institute for Health Research. This article presents independent research funded by the National Institute for Health Research (NIHR) under the Programme Grants for Applied Research programme (RP-PG-1210-12015 – C-CHANGE: Delivering high quality and cost-effective care across the range of complexity for those with advanced conditions in the last year of life). Further information is available at http://www.csi.kcl.ac.uk/c-change1.html. The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, MRC, CCF, NETSCC, the NIHR Programme Grants for Applied Research or the Department of Health

Elevated pulse pressure is associated with hemolysis, proteinuria and chronic kidney disease in sickle cell disease

A seeming paradox of sickle cell disease is that patients do not suffer from a high prevalence of systemic hypertension in spite of endothelial dysfunction, chronic inflammation and vasculopathy. However, some patients do develop systolic hypertension and increased pulse pressure, an increasingly recognized major cardiovascular risk factor in other populations. Hence, we hypothesized that pulse pressure, unlike other blood pressure parameters, is independently associated with markers of hemolytic anemia and cardiovascular risk in sickle cell disease. We analyzed the correlates of pulse pressure in patients (n 5 661) enrolled in a multicenter international sickle cell trial. Markers of hemolysis were analyzed as independent variables and as a previously validated hemolytic index that includes multiple variables. We found that pulse pressure, not systolic, diastolic or mean arterial pressure, independently correlated with high reticulocyte count (beta 5 2.37, p 5 0.02) and high hemolytic index (beta 5 1.53, p50.002) in patients with homozygous sickle cell disease in two multiple linear regression models which include the markers of hemolysis as independent variables or the hemolytic index, respectively. Pulse pressure was also independently associated with elevated serum creatinine (beta 5 3.21, p 5 0.02), and with proteinuria (beta 5 2.52, p 5 0.04). These results from the largest sickle cell disease cohort to date since the Cooperative Study of Sickle Cell Disease show that pulse pressure is independently associated with hemolysis, proteinuria and chronic kidney disease. We propose that high pulse pressure may be a risk factor for clinical complications of vascular dysfunction in sickle cell disease. Longitudinal and mechanistic studies should be conducted to confirm these hypotheses

Hepatoprotective Effect Of Cymbopogon Citratus Aqueous Extract Against Hydrogen Peroxide-Induced Liver Injury In Male Rats

Background: Cymbopogon citratus (Poaceae) a tropical perennial herb plant that is widely cultivated to be eaten either fresh with food or dried in tea or soft drink has been reported to possess a number of medicinal and aromatic properties. This study aimed at evaluating the protective effects of C. citratus aqueous extract against liver injury induced by hydrogen peroxide (H2O2), in male rats.Materials and Methods: Twenty-five rats were randomly divided into five different groups of five animals in each group; (1) Control. (2) Received H2O2 (0.5%) with drinking water. (3), and (4) received H2O2 and C. citratus (100 mg·kg-1 b wt), vitamin C (250 mg·kg-1 b wt) respectively. (5), was given C. citratus alone. The treatments were administered for 30 days. Blood samples were collected and serum was used for biochemical assay including liver enzymes activities, total protein, total bilirubin and malonaldehyde, glutathione in serum and liver homogenates. Liver was excised and routinely processed for histological examinations.Results: C. citratus attenuated liver damage due to H2O2 administration as indicated by the significant reduction (p<0.05), in the elevated levels of ALT, AST, ALP, LDH, TB, and MDA in serum and liver homogenates; increase in TP and GSH levels in serum and liver homogenates; and improvement of liver histo-pathological changes. These effects of the extract were similar to that of vitamin C which used as antioxidant reference.Conclusion: C. citratus could effectively ameliorate H2O2-induced oxidative stress and prevent liver injury in male rats.Key Words: Cymbopogon citratus, Vitamin C, Hydrogen peroxide, Rat, Liver enzymes, Serum proteins, Histopathology

Finding a 'new normal' following acute illness: A qualitative study of influences on frail older people's care preferences.

BACKGROUND:: The frail older population is growing, and many frail older people have episodes of acute illness. Patient preferences are increasingly considered important in the delivery of person-centred care and may change following acute illness. AIM:: To explore influences on the care preferences of frail older people with recent acute illness. DESIGN:: Qualitative in-depth individual interviews, with thematic analysis. SETTING/PARTICIPANTS:: Maximum variation sample of 18 patients and 7 nominated family carers from a prospective cohort study of people aged over 65, scoring ⩾5 on the Clinical Frailty Scale, and with recent acute illness, who were not receiving specialist palliative care. Median patient age was 84 (inter-quartile range 81–87), 53% female. Median frailty score 6 (inter-quartile range 5–7). RESULTS:: Key influences on preferences were illness and care context, particularly hospital care; adaptation to changing health; achieving normality and social context. Participants focused on the outcomes of their care; hence, whether care was likely to help them ‘get back to normal’, or alternatively ‘find a new normal’ influenced preferences. For some, acute illness inhibited preference formation. Participants’ social context and the people available to provide support influenced place of care preferences. We combined these findings to model influences on preferences. CONCLUSION:: ‘Getting back to normal’ or ‘finding a new normal’ are key focuses for frail older people when considering their preferences. Following acute illness, clinicians should discuss preferences and care planning in terms of an achievable normal, and carefully consider the social context. Longitudinal research is needed to explore the influences on preferences over time.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was independent research funded by Cicely Saunders International and the Atlantic Philanthropies (grant 24610). The sponsor had no role in the design, methods, subject recruitment, data collection, analysis or preparation of this article. This research was supported by the collaboration for Leadership in Applied Health Research and Care, South London, which is part of the National Institute for Health Research (NIHR), and is a partnership between King’s Health Partners, St. George’s University London, and St George’s Healthcare National Health Service (NHS) Trust. I.J.H. is an Emeritus NIHR Senior Investigator. The views expressed in this publication are those of the authors and not necessarily those of the NHS, NIHR, or the Department of Health and Social Care

What is the impact of population ageing on the future provision of end-of-life care? Population-based projections of place of death.

BACKGROUND: Population ageing represents a global challenge for future end-of-life care. Given new trends in place of death, it is vital to examine where the rising number of deaths will occur in future years and implications for health and social care. AIM: To project where people will die from 2015 to 2040 across all care settings in England and Wales. DESIGN: Population-based trend analysis and projections using simple linear modelling. Age- and gender-specific proportions of deaths in hospital, care home, home, hospice and 'other' were applied to numbers of expected future deaths. Setting/population: All deaths (2004-2014) from death registration data and predicted deaths (2015-2040) from official population forecasts in England and Wales. RESULTS: Annual deaths are projected to increase from 501,424 in 2014 (38.8% aged 85 years and over) to 635,814 in 2040 (53.6% aged 85 years and over). Between 2004 and 2014, proportions of home and care home deaths increased (18.3%-22.9% and 16.7%- 21.2%) while hospital deaths declined (57.9%-48.1%). If current trends continue, numbers of deaths in care homes and homes will increase by 108.1% and 88.6%, with care home the most common place of death by 2040. If care home capacity does not expand and additional deaths occur in hospital, hospital deaths will start rising by 2023. CONCLUSION: To sustain current trends, end-of-life care provision in care homes and the community needs to double by 2040. An infrastructure across care settings that supports rising annual deaths is urgently needed; otherwise, hospital deaths will increase.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work is independent research funded by Cicely Saunders International and The Atlantic Philanthropies (grant number 24610). This research was supported by the Collaboration for Leadership in Applied Health Research and Care (CLAHRC) South London, which is part of the National Institute for Health Research (NIHR), and is a partnership between King’s Health Partners, St. George’s, University London and St George’s Healthcare NHS Trust. I.J.H. is an NIHR Senior Investigator. C.J.E. is funded by a Health Education England (HEE)/NIHR Senior Clinical Lectureship. B.G. is funded by the Calouste Gulbenkian Foundation. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health

Analysis of the giant genomes of Fritillaria (Liliaceae) indicates that a lack of DNA removal characterizes extreme expansions in genome size.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Plants exhibit an extraordinary range of genome sizes, varying by > 2000-fold between the smallest and largest recorded values. In the absence of polyploidy, changes in the amount of repetitive DNA (transposable elements and tandem repeats) are primarily responsible for genome size differences between species. However, there is ongoing debate regarding the relative importance of amplification of repetitive DNA versus its deletion in governing genome size. Using data from 454 sequencing, we analysed the most repetitive fraction of some of the largest known genomes for diploid plant species, from members of Fritillaria. We revealed that genomic expansion has not resulted from the recent massive amplification of just a handful of repeat families, as shown in species with smaller genomes. Instead, the bulk of these immense genomes is composed of highly heterogeneous, relatively low-abundance repeat-derived DNA, supporting a scenario where amplified repeats continually accumulate due to infrequent DNA removal. Our results indicate that a lack of deletion and low turnover of repetitive DNA are major contributors to the evolution of extremely large genomes and show that their size cannot simply be accounted for by the activity of a small number of high-abundance repeat families.Thiswork was supported by the Natural Environment ResearchCouncil (grant no. NE/G017 24/1), the Czech Science Fou nda-tion (grant no. P501/12/G090), the AVCR (grant no.RVO:60077344) and a Beatriu de Pinos postdoctoral fellowshipto J.P. (grant no. 2011-A-00292; Catalan Government-E.U. 7thF.P.)

Ovarian cancer symptom awareness and anticipated delayed presentation in a population sample

Background: While ovarian cancer is recognised as having identifiable early symptoms, understanding of the key determinants of symptom awareness and early presentation is limited. A population-based survey of ovarian cancer awareness and anticipated delayed presentation with symptoms was conducted as part of the International Cancer Benchmarking Partnership (ICBP). Methods: Women aged over 50 years were recruited using random probability sampling (n = 1043). Computer-assisted telephone interviews were used to administer measures including ovarian cancer symptom recognition, anticipated time to presentation with ovarian symptoms, health beliefs (perceived risk, perceived benefits/barriers to early presentation, confidence in symptom detection, ovarian cancer worry), and demographic variables. Logistic regression analysis was used to identify the contribution of independent variables to anticipated presentation (categorised as < 3 weeks or ≥ 3 weeks). Results: The most well-recognised symptoms of ovarian cancer were post-menopausal bleeding (87.4%), and persistent pelvic (79.0%) and abdominal (85.0%) pain. Symptoms associated with eating difficulties and changes in bladder/bowel habits were recognised by less than half the sample. Lower symptom awareness was significantly associated with older age (p ≤ 0.001), being single (p ≤ 0.001), lower education (p ≤ 0.01), and lack of personal experience of ovarian cancer (p ≤ 0.01). The odds of anticipating a delay in time to presentation of ≥ 3 weeks were significantly increased in women educated to degree level (OR = 2.64, 95% CI 1.61 – 4.33, p ≤ 0.001), women who reported more practical barriers (OR = 1.60, 95% CI 1.34 – 1.91, p ≤ 0.001) and more emotional barriers (OR = 1.21, 95% CI 1.06 – 1.40, p ≤ 0.01), and those less confident in symptom detection (OR = 0.56, 95% CI 0.42 – 0.73, p ≤ 0.001), but not in those who reported lower symptom awareness (OR = 0.99, 95% CI 0.91 – 1.07, p = 0.74). Conclusions: Many symptoms of ovarian cancer are not well-recognised by women in the general population. Evidence-based interventions are needed not only to improve public awareness but also to overcome the barriers to recognising and acting on ovarian symptoms, if delays in presentation are to be minimised

Information-theoretic postulates for quantum theory

Why are the laws of physics formulated in terms of complex Hilbert spaces? Are there natural and consistent modifications of quantum theory that could be tested experimentally? This book chapter gives a self-contained and accessible summary of our paper [New J. Phys. 13, 063001, 2011] addressing these questions, presenting the main ideas, but dropping many technical details. We show that the formalism of quantum theory can be reconstructed from four natural postulates, which do not refer to the mathematical formalism, but only to the information-theoretic content of the physical theory. Our starting point is to assume that there exist physical events (such as measurement outcomes) that happen probabilistically, yielding the mathematical framework of "convex state spaces". Then, quantum theory can be reconstructed by assuming that (i) global states are determined by correlations between local measurements, (ii) systems that carry the same amount of information have equivalent state spaces, (iii) reversible time evolution can map every pure state to every other, and (iv) positivity of probabilities is the only restriction on the possible measurements.Comment: 17 pages, 3 figures. v3: some typos corrected and references updated. Summarizes the argumentation and results of arXiv:1004.1483. Contribution to the book "Quantum Theory: Informational Foundations and Foils", Springer Verlag (http://www.springer.com/us/book/9789401773027), 201