1,850 research outputs found

    Trehalose Is A Chemical Attractant In The Establishment Of Coral Symbiosis

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    Coral reefs have evolved with a crucial symbiosis between photosynthetic dinoflagellates (genus Symbiodinium) and their cnidarian hosts (Scleractinians). Most coral larvae take up Symbiodinium from their environment; however, the earliest steps in this process have been elusive. Here we demonstrate that the disaccharide trehalose may be an important signal from the symbiont to potential larval hosts. Symbiodinium freshly isolated from Fungia scutaria corals constantly released trehalose (but not sucrose, maltose or glucose) into seawater, and released glycerol only in the presence of coral tissue. Spawning Fungia adults increased symbiont number in their immediate area by excreting pellets of Symbiodinium, and when these naturally discharged Symbiodinium were cultured, they also released trehalose. In Y-maze experiments, coral larvae demonstrated chemoattractant and feeding behaviors only towards a chamber with trehalose or glycerol. Concomitantly, coral larvae and adult tissue, but not symbionts, had significant trehalase enzymatic activities, suggesting the capacity to utilize trehalose. Trehalase activity was developmentally regulated in F. scutaria larvae, rising as the time for symbiont uptake occurs. Consistent with the enzymatic assays, gene finding demonstrated the presence of a trehalase enzyme in the genome of a related coral, Acropora digitifera, and a likely trehalase in the transcriptome of F. scutaria. Taken together, these data suggest that adult F. scutaria seed the reef with Symbiodinium during spawning and the exuded Symbiodinium release trehalose into the environment, which acts as a chemoattractant for F. scutaria larvae and as an initiator of feeding behavior- the first stages toward establishing the coral-Symbiodinium relationship. Because trehalose is a fixed carbon compound, this cue would accurately demonstrate to the cnidarian larvae the photosynthetic ability of the potential symbiont in the ambient environment. To our knowledge, this is the first report of a chemical cue attracting the motile coral larvae to the symbiont

    Establishing a Center to Support Faculty Research

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    This is the author's accepted manuscript. The original publication is available at http://dx.doi.org/10.1007/s10755-005-8347-z.This article describes the establishment in fall 2002 of a School of Education Research Center designed to support faculty in increasing productivity and quality in research. Details are provided about center goals, services, staffing, space, resources, and logistics during the first year of operation. In addition, data are shared about faculty usage of the Center, the level of faculty satisfaction with center services in the first year, and initial increases in faculty productivity. The article concludes with plans for continued data collection to monitor the impact of the Center, a discussion of lessons learned at this point in the Center's development, and possibilities for the evolution of the Center

    Is the observed high-frequency radio luminosity distribution of QSOs bimodal?

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    The distribution of QSO radio luminosities has long been debated in the literature. Some argue that it is a bimodal distribution, implying that there are two separate QSO populations (normally referred to as 'radio-loud' and 'radio-quiet'), while others claim it forms a more continuous distribution characteristic of a single population. We use deep observations at 20 GHz to investigate whether the distribution is bimodal at high radio frequencies. Carrying out this study at high radio frequencies has an advantage over previous studies as the radio emission comes predominantly from the core of the AGN, hence probes the most recent activity. Studies carried out at lower frequencies are dominated by the large scale lobes where the emission is built up over longer timescales (10^7-10^8 yrs), thereby confusing the sample. Our sample comprises 874 X-ray selected QSOs that were observed as part of the 6dF Galaxy Survey. Of these, 40% were detected down to a 3 sigma detection limit of 0.2-0.5 mJy. No evidence of bimodality is seen in either the 20 GHz luminosity distribution or in the distribution of the R_20 parameter: the ratio of the radio to optical luminosities traditionally used to classify objects as being either radio-loud or radio-quiet. Previous results have claimed that at low radio luminosities, star formation processes can dominate the radio emission observed in QSOs. We attempt to investigate these claims by stacking the undetected sources at 20 GHz and discuss the limitations in carrying out this analysis. However, if the radio emission was solely due to star formation processes, we calculate that this corresponds to star formation rates ranging from ~10 solar masses/yr to ~2300 solar masses/yr.Comment: 13 pages, 11 figures. Accepted for publication in Ap

    Learning about the complexity of humanised care: findings from a longitudinal study of nurse students’ perceptions

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    Background, including underpinning literature and, wherever possible, the international relevance of the research The rise in elderly populations with complex long-term conditions is a global phenomenon (World Health Organisation, 2011). However evidence has emerged internationally around concerns about quality of care, particularly for older people (Katz 2011; Organisation for Economic Cooperation and Development, 2013). It has been argued that in target-driven care environments, there is the potential for care professionals to lose sight of the person receiving the care and focuses on task-completion, resulting in dehumanising care cultures (Galvin and Todres 2013). Educating nurse students to effectively as well as compassionately deliver complex care to vulnerable people represents considerable challenges. Following a number of high profile examples of poor quality care in the United Kingdom (UK) (Francis 2013), health profession education providers now follow professional body guidelines that mandate that values for compassionate practice clearly underpin curricula. Limited evidence exists however, concerning the impact of this initiative over time. This paper reports on a study that evidences the impact on students of an education programme based on a humanising care philosophy in shaping the students’ value base as they progress through their education programmes. Aim(s) and/or research question(s)/research hypothesis(es) . This paper reports on a five-phase longitudinal study exploring the impact of an undergraduate-nursing curriculum based on a humanising care philosophy on the values of individual students. Research methodology/research design, any ethical issues, and methods of data collection and analysis The study uses a qualitative longitudinal approach to understanding the beliefs and values of student nurses from the day of entry, through their education programme to completion. Focusing on two cohorts of students one year apart, data were collected by individual interview at commencement and completion and by focus groups at the end of their first placement and at the end of their first and second years. This presentation reports up to the end of the programme for the first cohort and end of second year for the second cohort. Ethics approval was gained for the entire project. At each stage of the process, students were formally invited to participate and on-going individual consent was gained. The audio-recordings were transcribed verbatim and analysed thematically. Key findings and recommendations By the end of their first placement, both groups were very similar in the expression of their values and to some extent presented a rather negative view of their experiences. However students from both groups became more articulate in expressing their values particularly in relation to their placement experience, as they moved through their programme. Four on-going and developing themes emerged from the data: personal journey, impact of the curriculum, impact of practice and values development. Overall, although each cohort followed two distinct curricula, there were few differences between the groups at each stage. Reasons for this will be discussed. Both groups felt they had become less judgmental, that the curriculum had empowered them to challenge practice and enhanced their confidence. Students also reported that their mentors (placement supervisors) role modelled authentic compassionate care in practice. Over time students’ insight into the complexity of caring developed and their understanding of the importance of practice that respected patient individuality deepened. This study has evidenced the strong link between curriculum and its impact on the evolving values of nursing students. Whilst this paper reports on a local study from one university in the UK, transferability of findings to other settings can be judged; it is argued that the insights will have resonance for nurse educators more widely as well as other health professional disciplines. References Commissioning Board Chief Nursing Officer and Department of Health Chief Nurse Advisor (2012). Compassion in Practice: Nursing, Midwifery and Care Staff. Our vision and strategy. Retrieved 22nd January 2016 from: http://www.england.nhs.uk/wp-content/uploads/2012/12/compassion-in-practice.pdf Francis Inquiry, (2013). Report of the Mid Staffordshire NHS Foundation Trust Public Inquiry: Executive summary. Crown Copyright: London. Galvin, K., Todres, L. (2013). Caring and Well-Being: A Lifeworld Approach. Routledge: Abingdon, Oxon. Katz, P.R. (2011). An International Perspective on Long Term Care: Focus on Nursing Homes. Journal of American Medical Directors Association. 12 (7): 487-492 OECD (2013) OECD Reviews of Health Care Quality: Denmark. Retrieved 7th Retrieved 22nd January 2016 from: http://www.oecd.org/els/health-systems/ReviewofHealthCareQualityDENMARK_ExecutiveSummary.pdf WHO (2011) Global Health and Ageing. Retrieved 22nd January 2016 from: http://www.who.int/ageing/publications/global_health.pdf Key words: (5) ‱ Nurse education ‱ Professional values ‱ Humanising care ‱ Curriculum ‱ Longitudinal qualitative research 3 key points to indicate how your work contributes to knowledge development within the selected theme ‱ Nursing students were able to clearly articulate values that underpin humanised care ‱ This study provides evidence for the strong link between curriculum and its impact on the evolving values of nursing students ‱ The curriculum is one factor in embedding humanised values in nursing students; further research is required

    Theoretical studies of the historical development of the accounting discipline: a review and evidence

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    Many existing studies of the development of accounting thought have either been atheoretical or have adopted Kuhn's model of scientific growth. The limitations of this 35-year-old model are discussed. Four different general neo-Kuhnian models of scholarly knowledge development are reviewed and compared with reference to an analytical matrix. The models are found to be mutually consistent, with each focusing on a different aspect of development. A composite model is proposed. Based on a hand-crafted database, author co-citation analysis is used to map empirically the entire literature structure of the accounting discipline during two consecutive time periods, 1972–81 and 1982–90. The changing structure of the accounting literature is interpreted using the proposed composite model of scholarly knowledge development

    The effect of accent exposure on children’s sociolinguistic evaluation of peers

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    Language and accent strongly influence the formation of social groups. By five years of age, children already show strong social preferences for peers who speak their native language with a familiar accent (Kinzler, Shutts, DeJesus, & Spelke, 2009). However, little is known about the factors that modulate the strength and direction of children’s accent-based group preferences. In three experiments, we examine the development of accent-based friendship preferences in children growing up in Toronto, one of the world’s most linguistically and culturally diverse cities. We hypothesized that the speaker’s type of accent and the amount of accent exposure children experienced in their everyday lives would modulate their preferences in a friend selection task. Despite literature suggesting that exposure leads to greater acceptance (Allport, 1954), we find no evidence that routine exposure to different accents leads to greater acceptance of unfamiliarly accented speakers. Children still showed strong preferences for peers who spoke with the locally dominant accent, despite growing up in a linguistically diverse community. However, children’s preference for Canadian-accented in-group members was stronger when they were paired with non native (Korean-accented) speakers compared to when they were paired with regional (British-accented) speakers. We propose that children’s ability to perceptually distinguish between accents may have contributed to this difference. Children showed stronger preferences for in-group members when the difference between accents was easier to perceive. Overall, our findings suggest that although the strength of accent-based social preferences can be modulated by the type of accent, these preferences still persist in the face of significant diversity in children’s accent exposure

    The association between protease inhibitors and anal cancer outcomes in veterans living with HIV treated with definitive chemoradiation: a retrospective study

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    Background: The incidence of anal squamous cell carcinoma has been increasing, particularly in people living with HIV (PLWH). There is concern that radiosensitizing drugs, such as protease inhibitors, commonly used in the management of HIV, may increase toxicities in patients undergoing chemoradiation. This study examines treatment outcomes and toxicities in PLWH managed with and without protease inhibitors who are receiving chemoradiation for anal cancer. Methods: Patient demographic, HIV management, and cancer treatment information were extracted from multiple Veterans Affairs databases. Patients were also manually chart reviewed. Among PLWH undergoing chemoradiation for anal carcinoma, therapy outcomes and toxicities were compared between those treated with and without protease inhibitors at time of cancer treatment. Statistical analysis was performed using chi-square, Cox regression analysis, and logistic regression. Results: A total of 219 PLWH taking anti-retroviral therapy undergoing chemoradiation for anal cancer were identified and included in the final analysis. The use of protease inhibitors was not associated with any survival outcome including colostomy-free survival, progression-free survival, or overall survival (all adjusted hazard ratio p-values\u3e 0.05). Regarding toxicity, protease inhibitor use was not associated with an increased odds of hospitalizations or non-hematologic toxicities; however, protease inhibitor use was associated with increased hospitalizations for hematologic toxicities, including febrile neutropenia (p \u3c 0.01). Conclusion: The use of protease inhibitors during chemoradiation for anal carcinoma was not associated with any clinical outcome or increase in non-hematologic toxicity. Their use was associated with increased hospitalizations for hematologic toxicities. Further prospective research is needed to evaluate the safety and efficacy of protease inhibitors for patients undergoing chemoradiation

    Different methodological approaches to the assessment of in vivo efficacy of three artemisinin-based combination antimalarial treatments for the treatment of uncomplicated falciparum malaria in African children.

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    BACKGROUND: Use of different methods for assessing the efficacy of artemisinin-based combination antimalarial treatments (ACTs) will result in different estimates being reported, with implications for changes in treatment policy. METHODS: Data from different in vivo studies of ACT treatment of uncomplicated falciparum malaria were combined in a single database. Efficacy at day 28 corrected by PCR genotyping was estimated using four methods. In the first two methods, failure rates were calculated as proportions with either (1a) reinfections excluded from the analysis (standard WHO per-protocol analysis) or (1b) reinfections considered as treatment successes. In the second two methods, failure rates were estimated using the Kaplan-Meier product limit formula using either (2a) WHO (2001) definitions of failure, or (2b) failure defined using parasitological criteria only. RESULTS: Data analysed represented 2926 patients from 17 studies in nine African countries. Three ACTs were studied: artesunate-amodiaquine (AS+AQ, N = 1702), artesunate-sulphadoxine-pyrimethamine (AS+SP, N = 706) and artemether-lumefantrine (AL, N = 518).Using method (1a), the day 28 failure rates ranged from 0% to 39.3% for AS+AQ treatment, from 1.0% to 33.3% for AS+SP treatment and from 0% to 3.3% for AL treatment. The median [range] difference in point estimates between method 1a (reference) and the others were: (i) method 1b = 1.3% [0 to 24.8], (ii) method 2a = 1.1% [0 to 21.5], and (iii) method 2b = 0% [-38 to 19.3].The standard per-protocol method (1a) tended to overestimate the risk of failure when compared to alternative methods using the same endpoint definitions (methods 1b and 2a). It either overestimated or underestimated the risk when endpoints based on parasitological rather than clinical criteria were applied. The standard method was also associated with a 34% reduction in the number of patients evaluated compared to the number of patients enrolled. Only 2% of the sample size was lost when failures were classified on the first day of parasite recurrence and survival analytical methods were used. CONCLUSION: The primary purpose of an in vivo study should be to provide a precise estimate of the risk of antimalarial treatment failure due to drug resistance. Use of survival analysis is the most appropriate way to estimate failure rates with parasitological recurrence classified as treatment failure on the day it occurs

    Deficiency of the zinc finger protein ZFP106 causes motor and sensory neurodegeneration

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    Acknowledgements We are indebted to Jim Humphries, JennyCorrigan, LizDarley, Elizabeth Joynson, Natalie Walters, Sara Wells and the whole necropsy, histology, genotyping and MLC ward 6 teams at MRC Harwell for excellent technical assistance. We thank the staff of the WTSI Illumina Bespoke Team for the RNA-seq data, the Sanger Mouse Genetics Project for the initial mouse characterization and Dr David Adams for critical reading of the manuscript. We also thank KOMP for the mouse embryonic stem cells carrying the knockout first promoter-less allele (tm1a(KOMP)Wtsi) within Zfp016. Conflict of Interest statement. None declared. Funding This work was funded by the UK Medical Research Council (MRC) to A.A.-A. and a Motor Neurone Disease Association (MNDA) project grant to A.A.-A. and EMCF. D.L.H.B. is a Wellcome Trust Senior Clinical Scientist Fellow and P.F. is a MRC/MNDA Lady Edith Wolfson Clinician Scientist Fellow. Funding to pay the Open Access publication charges for this article was provided by the MRC grant number: MC_UP_A390_1106.Peer reviewedPublisher PD
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