Ca(2+) sparks promote myogenic tone in retinal arterioles

Background and Purpose: Ca(2+) imaging reveals subcellular Ca(2+) sparks and global Ca(2+) waves/oscillations in vascular smooth muscle. It is well established that Ca(2+) sparks can relax arteries, but we have previously reported that sparks can summate to generate Ca(2+) waves/oscillations in unpressurized retinal arterioles, leading to constriction. We have extended these studies to test the functional significance of Ca(2+) sparks in the generation of myogenic tone in pressurized arterioles.

Experimental Approach: Isolated retinal arterioles (25-40 μm external diameter) were pressurized to 70 mmHg, leading to active constriction. Ca(2+) signals were imaged from arteriolar smooth muscle in the same vessels using Fluo4 and confocal laser microscopy.

Key Results: Tone development was associated with an increased frequency of Ca(2+) sparks and oscillations. Vasomotion was observed in 40% of arterioles and was associated with synchronization of Ca(2+) oscillations, quantifiable as an increased cross-correlation coefficient. Inhibition of Ca(2+) sparks with ryanodine, tetracaine, cyclopiazonic acid or nimodipine, or following removal of extracellular Ca(2+) , resulted in arteriolar relaxation. Cyclopiazonic acid-induced dilatation was associated with decreased Ca(2+) sparks and oscillations but with a sustained rise in the mean global cytoplasmic [Ca(2+) ] ([Ca(2+) ]c ), as measured using Fura2 and microfluorimetry.

Conclusions and Implications: This study provides direct evidence that Ca(2+) sparks can play an excitatory role in pressurized arterioles, promoting myogenic tone. This contrasts with the generally accepted model in which sparks promote relaxation of vascular smooth muscle. Changes in vessel tone in the presence of cyclopiazonic acid correlated more closely with changes in spark and oscillation frequency than global [Ca(2+) ]c , underlining the importance of frequency-modulated signalling in vascular smooth muscle.

From an American Plantation to Interwar Poland: How Uncle Remus Became Bam-Bo the Negro

The article opens with the introduction of Joel Chandler Harris and his literary output. As one of “local colourists,” Harris depicted American plantation life in 19th-century Georgia and included many cultural as well as folk elements in his works. The following analysis of his stories about Uncle Remus focuses on (1) the levels of narration; (2) the linguistic complexity of the text (the stories abound in slang and dialectal expressions); (3) the form; and (4) the folklore value. These four aspects guide the discussion of the only Polish translation of the Uncle Remus stories. Prepared by Wladyslawa Wielinska in 1929, it was addressed to children. Therefore, the article aims to determine the profile of the translation as a children’s book, to consider it in relation to the skopos of the source text and to establish the extent to which it preserved the peculiar character of the Uncle Remus stories.

Knowledge Formation and the Great Divergence between China and Europe: Manuscripts and Printed Books, ca. 581–1840

Literature dealing with the history of Chinese printed books and printing is voluminous. Yet studies of how knowledge in general and utilitarian forms of knowledge in particular were generated, accumulated and circulated by printed books and their relationship with the long-term socio-economic transformation of China are rare. This paper aims to open up the subject by examining the long-term trends in the production of manuscripts and books and focusing on the connections between the generation and dissemination of useful knowledge in China and the production and circulation of printed books over the centuries and dynasties from circa 581 to 1840 compared to Europe. It connects trends in this indicator for knowledge formation and diffusion to economic growth, urbanization, changes in higher forms of education, the rise of literacy, the development of printing technologies, and changes in perceptions of the natural world. It concludes that human capital formation in China probably proceeded at a slower rate,which is relevant for narratives of the “divergence” between China and Europe.

Eve and evolution: Christian responses to the first woman question, 1860-1900

Historians of encounters between evolutionary science and Christianity have long been aware of the significance placed upon debates about the applicability of evolution to Adam. It has not been widely noticed, however, that in more conservative circles the creation of Eve was frequently thought to be a more difficult problem to solve. This essay examines how, in distinctive ways, the creation of Eve became a point of contention among three communities of conservative Christian thinkers grappling with the implications of evolutionary theory in the period 1860-1900.

An analysis of the talent management challenges in a post-communist country: the case of Poland

There is a dearth of empirical studies on talent management (TM) in the emerging markets, and in particular a lack of research on TM in the countries of the Central and Eastern European (CEE) region. Our empirical study in 58 organisations in Poland, a major economy in the CEE region, is one of the first studies to examine TM in this context. Our study highlights the particular nature of the TM challenges facing organisations in Poland and shows that there is little evidence to suggest that Polish practice is converging with Western models. Our paper suggests that TM is likely to challenge many traditional management practices and attitudes which continue to dominate Polish culture in the period of transition to a market economy.

Switching between molecular switch types by module rearrangement:Ca -enabled, H-driven 'off-on-off', H-driven YES and PASS 0 as well as H, Ca-driven AND logic operations

Several logic gates and switches can be accessed from two different combinations of a single set of fluorophore, receptor and spacer components.

Tracking magnetic bright point motions through the solar atmosphere

High-cadence, multiwavelength observations and simulations are employed for the analysis of solar photospheric magnetic bright points (MBPs) in the quiet Sun. The observations were obtained with the Rapid Oscillations in the Solar Atmosphere (ROSA) imager and the Interferometric Bidimensional Spectrometer at the Dunn Solar Telescope. Our analysis reveals that photospheric MBPs have an average transverse velocity of approximately 1 km s-1, whereas their chromospheric counterparts have a slightly higher average velocity of 1.4 km s-1. Additionally, chromospheric MBPs were found to be around 63 per cent larger than the equivalent photospheric MBPs. These velocity values were compared with the output of numerical simulations generated using the muram code. The simulated results were similar, but slightly elevated, when compared to the observed data. An average velocity of 1.3 km s-1 was found in the simulated G-band images and an average of 1.8 km s-1 seen in the velocity domain at a height of 500 km above the continuum formation layer. Delays in the change of velocities were also analysed. Average delays of ˜4 s between layers of the simulated data set were established and values of ˜29 s observed between G-band and Ca ii K ROSA observations. The delays in the simulations are likely to be the result of oblique granular shock waves, whereas those found in the observations are possibly the result of a semi-rigid flux tube.

(Re)-Introducing Themes of Religion and Spirituality to Professional Social Work Training in the Land of ‘Saints and Scholars’.

This chapter begins by alluding to Ireland’s historical reputation as the land of “Saints and Scholars” and then briefly charts its demise from this position. A parallel process in relation to religiously motivated provision of health and social care is outlined. The inclusion of themes of religion and spirituality within the current professional social work codes in the USA and Britain and the framework for social work training in Northern Ireland is noted. In this context the lack of any substantive inclusion of themes of religion and/or spirituality within the Bachelor of Social Work (BSW) degree at Queens University Belfast will be situated. A series of intersecting reasons for this lack of inclusion are proposed in terms of the experience of living through the recent troubled history of Northern Ireland and a variety of biases in academic thought.
A rationale for the re-introduction of inputs on religion and spirituality is articulated in terms of the widespread resurgence of these themes within health and social care and psychotherapy literature and the new emphasis on practicing in culturally sensitive ways in Britain. The first steps to re-introduce these themes under the higher context marker of “culturally competent practice” are described and an analysis of data from the students’ feedback presented along with illustrative quotations. The dissonance between the initial misgivings of staff and the overwhelmingly positive responses of students are highlighted. The chapter concludes with a discussion of lessons learned through the process with an emphasis on how the inclusion of these themes can result in better practice for service users, including those impacted by “the Troubles” in Northern Ireland.

Electron excitation of Ca XVII

Electron-excitation collision strengths have been calculated for transitions between the ten lowest levels of Ca XVII (2sS, 2s2p P, 2s2p P, 2pP 2p D, 2pS ). At high impact energies, where all the channels are open, the calculation was carried out in the LS-coupling approximation by means of the R-matrix method. Transitions between the fine structure levels were then determined by application of a unitary transformation to the LS-coupled K-matrices. At low impact energies, where some of the channels may be closed, an extension of the R-matrix method was employed to take account of relativistic effects directly in the scattering equations. In general, results are in good agreement with recent distorted-wave calculations. Electron-excitation rates are given for a range of electron temperatures.