1,310 research outputs found
Some Aspects of Circulatory Stability
Based on a dissertation read before the Society on 11th February, 1966.The secrets of the circulatory system taxed the imaginations and resources of workers in every field of medicine long before even William Harvey produced his classical treatise in 1628 . Now , in 1966, the basic anatomy of the circulatory system is widely accepted but the relative importance of various homeostatic mechanisms in the patho-physiology of this system is still the subject of constant debate; this is no mere ‘academic exercise’, for the disorders of the circulatory system are becoming major problems throughout the world and they merit careful consideration. Nevertheless this dissertation is not a review. I attempt to outline a few aspects of the subject which are of particular interest, and so well accepted and established concepts are included along with some more recent work
A Multiwavelength Photometric Census of AGN and Star Formation Activity in the Brightest Cluster Galaxies of X-ray Selected Clusters
Despite their reputation as being ‘red and dead’, the unique environment inhabited by brightest cluster galaxies (BCGs) can often lead to a self-regulated feedback cycle between radiatively cooling intracluster gas and star formation and active galactic nucleus (AGN) activity in the BCG. However the prevalence of ‘active’ BCGs, and details of the feedback involved, are still uncertain. We have performed an optical, UV and mid-IR photometric analysis of the BCGs in 981 clusters at 0.03 < z < 0.5, selected from the ROSAT All Sky Survey. Using Pan-STARRS PS1 3π, GALEX and WISE survey data we look for BCGs with photometric colours which deviate from that of the bulk population of passive BCGs – indicative of AGN and/or star formation activity within the BCG. We find that whilst the majority of BCGs are consistent with being passive, at least 14 per cent of our BCGs show a significant colour offset from passivity in at least one colour index. And, where available, supplementary spectroscopy reveals the majority of these particular BCGs show strong optical emission lines. On comparing BCG ‘activity’ with the X-ray luminosity of the host cluster, we find that BCGs showing a colour offset are preferentially found in the more X-ray luminous clusters, indicative of the connection between BCG ‘activity’ and the intracluster medium
Oxygen adsorption on the Ru (10 bar 1 0) surface: Anomalous coverage dependence
Oxygen adsorption onto Ru (10 bar 1 0) results in the formation of two
ordered overlayers, i.e. a c(2 times 4)-2O and a (2 times 1)pg-2O phase, which
were analyzed by low-energy electron diffraction (LEED) and density functional
theory (DFT) calculation. In addition, the vibrational properties of these
overlayers were studied by high-resolution electron loss spectroscopy. In both
phases, oxygen occupies the threefold coordinated hcp site along the densely
packed rows on an otherwise unreconstructed surface, i.e. the O atoms are
attached to two atoms in the first Ru layer Ru(1) and to one Ru atom in the
second layer Ru(2), forming zigzag chains along the troughs. While in the
low-coverage c(2 times 4)-O phase, the bond lengths of O to Ru(1) and Ru(2) are
2.08 A and 2.03 A, respectively, corresponding bond lengths in the
high-coverage (2 times 1)-2O phase are 2.01 A and 2.04 A (LEED). Although the
adsorption energy decreases by 220 meV with O coverage (DFT calculations), we
observe experimentally a shortening of the Ru(1)-O bond length with O coverage.
This effect could not be reconciled with the present DFT-GGA calculations. The
nu(Ru-O) stretch mode is found at 67 meV [c(2 times 4)-2O] and 64 meV [(2 times
1)pg-2O].Comment: 10 pages, figures are available as hardcopies on request by mailing
[email protected], submitted to Phys. Rev. B (8. Aug. 97), other related
publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm
Explaining effervescence: Investigating the relationship between shared social identity and positive experience in crowds
We investigated the intensely positive emotional experiences arising from participation in a large-scale collective event. We predicted such experiences arise when those attending a collective event are (1) able to enact their valued collective identity and (2) experience close relations with other participants. In turn, we predicted both of these to be more likely when participants perceived crowd members to share a common collective identity. We investigated these predictions in a survey of pilgrims (N = 416) attending a month-long Hindu pilgrimage festival in north India. We found participants’ perceptions of a shared identity amongst crowd members had an indirect effect on their positive experience at the event through (1) increasing participants’ sense that they were able to enact their collective identity and (2) increasing the sense of intimacy with other crowd members. We discuss the implications of these data for how crowd emotion should be conceptualised
Pharmacokinetics of rifampicin in adult TB patients and healthy volunteers: a systematic review and meta-analysis
Objectives: The objectives of this study were to explore inter-study heterogeneity in the pharmacokinetics (PK)
of orally administered rifampicin, to derive summary estimates of rifampicin PK parameters at standard dosages
and to compare these with summary estimates for higher dosages.
Methods: A systematic search was performed for studies of rifampicin PK published in the English language up
to May 2017. Data describing the Cmax and AUC were extracted. Meta-analysis provided summary estimates
for PK parameter estimates at standard rifampicin dosages. Heterogeneity was assessed by estimation of the
I
2 statistic and visual inspection of forest plots. Summary AUC estimates at standard and higher dosages were
compared graphically and contextualized using preclinical pharmacodynamic (PD) data.
Results: Substantial heterogeneity in PK parameters was evident and upheld in meta-regression. Treatment
duration had a significant impact on the summary estimates for rifampicin PK parameters, with Cmax 8.98 mg/L
(SEM 2.19) after a single dose and 5.79 mg/L (SEM 2.14) at steady-state dosing, and AUC 72.56 mgh/L
(SEM 2.60) and 38.73 mgh/L (SEM 4.33) after single and steady-state dosing, respectively. Rifampicin dosages of
at least 25 mg/kg are required to achieve plasma PK/PD targets defined in preclinical studies.
Conclusions: Vast inter-study heterogeneity exists in rifampicin PK parameter estimates. This is not explained by
the available modifying variables. The recommended dosage of rifampicin should be increased to improve efficacy. This study provides an important point of reference for understanding rifampicin PK at standard dosages
as efforts to explore higher dosing strategies continue in this field
Effect of Thyroid Hormone Therapy on Fatigability in Older Adults with Subclinical Hypothyroidism: A Nested Study within a Randomized Placebo-Controlled Trial
Background: Fatigue often triggers screening for and treatment of subclinical hypothyroidism. However, data on the impact of levothyroxine on fatigue is limited and previous studies might not have captured all aspects of fatigue. Method: This study is nested within the randomized, placebo-controlled, multicenter TRUST trial, including community-dwelling participants aged =65 and older, with persistent subclinical hypothyroidism (TSH 4.60-19.99 mIU/L, normal free thyroxine levels) from Switzerland and Ireland. Interventions consisted of daily levothyroxine starting with 50 µg (25 µg if weight <50 kg or known coronary heart diseases) together with dose adjustments to achieve a normal TSH and mock titration in the placebo group. Main outcome was the change in physical and mental fatigability using the Pittsburgh Fatigability Scale over 1 year, assessed through multivariable linear regression with adjustment for country, sex, and levothyroxine starting dose. Results: Among 230 participants, the mean ± standard deviation (SD) TSH was 6.2 ± 1.9 mIU/L at baseline and decreased to 3.1 ± 1.3 with LT4 (n = 119) versus 5.3 ± 2.3 with placebo (n = 111, p <. 001) after 1 year. After adjustment we found no between-group difference at 1 year on perceived physical (0.2; 95% CI -1.8 to 2.1; p =. 88), or mental fatigability (-1.0; 95% CI -2.8 to 0.8; p =. 26). In participants with higher fatigability at baseline (=15 points for the physical score [n = 88] or =13 points for the mental score [n = 41]), the adjusted between-group differences at 1 year were 0.4 (95% CI -3.6 to 2.8, p =. 79) and -2.2 (95% CI -8.8 to 4.5, p =. 51). Conclusions: Levothyroxine in older adults with mild subclinical hypothyroidism provides no change in physical or mental fatigability
An Introduction to Gas Accretion onto Galaxies
Evidence for gas accretion onto galaxies can be found throughout the
universe. In this chapter, I summarize the direct and indirect signatures of
this process and discuss the primary sources. The evidence for gas accretion
includes the star formation rates and metallicities of galaxies, the evolution
of the cold gas content of the universe with time, numerous indirect indicators
for individual galaxies, and a few direct detections of inflow. The primary
sources of gas accretion are the intergalactic medium, satellite gas and
feedback material. There is support for each of these sources from observations
and simulations, but the methods with which the fuel ultimately settles in to
form stars remain murky.Comment: 14 pages, 5 figures, Invited review to appear in Gas Accretion onto
Galaxies, Astrophysics and Space Science Library, eds. A. J. Fox & R. Dav\'e,
to be published by Springe
Social representations and the politics of participation
Recent work has called for the integration of different perspectives into the field of political psychology (Haste, 2012). This chapter suggests that one possible direction that such efforts can take is studying the role that social representations theory (SRT) can play in understanding political participation and social change. Social representations are systems of common-sense knowledge and social practice; they provide the lens through which to view and create social and political realities, mediate people's relations with these sociopolitical worlds and defend cultural and political identities. Social representations are therefore key for conceptualising participation as the activity that locates individuals and social groups in their sociopolitical world. Political participation is generally seen as conditional to membership of sociopolitical groups and therefore is often linked to citizenship. To be a citizen of a society or a member of any social group one has to participate as such. Often political participation is defined as the ability to communicate one's views to the political elite or to the political establishment (Uhlaner, 2001), or simply explicit involvement in politics and electoral processes (Milbrath, 1965). However, following scholars on ideology (Eagleton, 1991; Thompson, 1990) and social knowledge (Jovchelovitch, 2007), we extend our understanding of political participation to all social relations and also develop a more agentic model where individuals and groups construct, develop and resist their own views, ideas and beliefs. We thus adopt a broader approach to participation in comparison to other political-psychological approaches, such as personality approaches (e.g. Mondak and Halperin, 2008) and cognitive approaches or, more recently, neuropsychological approaches (Hatemi and McDermott, 2012). We move away from a focus on the individual's political behaviour and its antecedents and outline an approach that focuses on the interaction between psychological and political phenomena (Deutsch and Kinnvall, 2002) through examining the politics of social knowledge
Towards a synthesized critique of neoliberal biodiversity conservation
During the last three decades, the arena of biodiversity conservation has largely aligned itself with the globally dominant political ideology of neoliberalism and associated governmentalities. Schemes such as payments for ecological services are promoted to reach the multiple ‘wins’ so desired: improved biodiversity conservation, economic development, (international) cooperation and poverty alleviation, amongst others. While critical scholarship with respect to understanding the linkages between neoliberalism, capitalism and the environment has a long tradition, a synthesized critique of neoliberal conservation - the ideology (and related practices) that the salvation of nature requires capitalist expansion - remains lacking. This paper aims to provide such a critique. We commence with the assertion that there has been a conflation between ‘economics’ and neoliberal ideology in conservation thinking and implementation. As a result, we argue, it becomes easier to distinguish the main problems that neoliberal win-win models pose for biodiversity conservation. These are framed around three points: the stimulation of contradictions; appropriation and misrepresentation and the disciplining of dissent. Inspired by Bruno Latour’s recent ‘compositionist manifesto’, the conclusion outlines some ideas for moving beyond critique
Accumulation of Self-Reactive Naive and Memory B Cell Reveals Sequential Defects in B Cell Tolerance Checkpoints in Sjogren's Syndrome
This work was funded by grants number 18237 and 20089 from Arthritis Research UK (http://www.arthritisresearchuk.org) to MB and the William Harvey Research Foundation. EC was recipient of short-term travel fellowships from EMBO (ASTF 318-2010) and EFIS-IL
- …