Reading “On Time and Being” to Construct the ‘Missing’ Division III of Being and Time – or “time and Being” –

This paper will articulate the conditions of thinking about the transition of Division II in Heidegger’s Being and Time in order to imagine the architecture of the missing Division III, which never appeared in the published Part I of Being and Time. The paper explores questions of temporality, historical temporality, and Heidegger’s confrontation with Hegel at the end of Being and Time while enlisting the resources of his very late lecture of 1962 – “On Time and Being” – to lay down the conditions of possibility to reconstruct the missing Division III. The paper argues that this feat has yet to be adequately accomplished given 90 years that have elapsed since the publication of Being and Time

The Acute Responses of Different-sized Coronary Arteries to Testosterone

Coronary arteries supply blood to the myocardium. The blood flow within the coronary arteries is altered by various compounds produced within the body. Sex hormones such as testosterone are known to cause the relaxation of large coronary arteries. But the response to testosterone is greater in in vivo conditions compared to in vitro conditions. We hypothesize that the responses of LADs (left anterior descending arteries) and its side branches to testosterone are heterogeneous and testosterone-induced vasodilation is greater in its side branches. Therefore, our study was designed to determine the effect of testosterone in different-sized coronary arteries. LADs and one of its side branches were isolated from porcine hearts and mounted in organ baths to mimic in vivo conditions. The coronary arteries were then preconstricted with potassium chloride (KCl) and administered increasing concentrations of testosterone to determine if the responses to testosterone vary within different regions of the coronary circulation. The testosterone caused significant relaxation in both LADs and its side branches. However the side branches showed similar responses to testosterone as compared to the larger, upstream LADs. Further studies on androgen receptor expression using real time PCR indicated that androgen receptor expression was higher in LADs than its side branches. A third group of small coronary arteries exhibited greater androgen receptor expression than the LADs and its side branches. The enhanced testosterone-induced vascular reactivity exhibited in vivo may be at the level of the small coronary arteries, not the LAD and its side branches

Morphological response of the saltmarsh habitats of the Guadiana estuary due to flow regulation and sea-level rise

In the context of rapid sea-level rise in the 21st century, the reduction of fluvial sediment supply due to the regulation of river discharge represents a major challenge for the management of estuarine ecosystems. Therefore, the present study aims to assess the cumulative impacts of the reduction of river discharge and projected sea-level rise on the morphological evolution of the Guadiana estuary during the 21st century. The assessment was based on a set of analytical solutions to simplified equations of tidal wave propagation in shallow waters and empirical knowledge of the system. As methods applied to estimate environmental flows do not take into consideration the fluvial discharge required to maintain saltmarsh habitats and the impact of sea-level rise, simulations were carried out for ten cases in terms of base river flow and sea-level rise so as to understand their sensitivity on the deepening of saltmarsh platforms.Results suggest saltmarsh habitats may not be affected severely in response to lower limit scenarios of sea-level rise and sedimentation. A similar behaviour can be expected even due to the upper limit scenarios until 2050, but with a significant submergence afterwards. In the case of the upper limit scenarios under scrutiny, there was a net erosion of sediment from the estuary. Multiplications of amplitudes of the base flow function by factors 1.5, 2, and 5 result in reduction of the estimated net eroded sediment volume by 25, 40, and 80%, respectively, with respect to the net eroded volume for observed river discharge. The results also indicate that defining the minimum environmental flow as a percentage of dry season flow (as done presently) should be updated to include the full spectrum of natural flows, incorporating temporal variability to better anticipate scenarios of sea-level rise during this century. As permanent submergence of intertidal habitats can be significant after 2050, due to the projected 79 cm rise of sea-level by the year 2100, a multi-dimensional approach should be adopted to mitigate the consequences of sea-level rise and strong flow regulations on the ecosystem of the Guadiana Estuary. (C) 2016 Elsevier Ltd. All rights reserved

Towards realistic simulations of QED cascades: non-ideal laser and electron seeding effects

A number of analytical and numerical studies has been performed to investigate the onset and the development of QED cascades in the collision of two counterpropagating laser pulses as a function of the laser intensity. However, it has been recently demonstrated [M. Tamburini et al., Sci. Rep. 7, 5694 (2017)] that the onset of QED cascades is also strongly influenced by the structure of the laser pulses, such as the laser pulse waist radius. Here we investigate how QED cascades are affected by: (a) the laser pulse duration, (b) the presence of a relative delay for the peak of the laser pulses to reach the focus, (c) the existence of a mismatch between the laser focal axis of the two laser pulses. This is especially important as, in realistic laboratory conditions, fluctuations may arise in the temporal and point stability of the lasers.Comment: 10 pages, 5 figures, 2 tables. Accepted for publication in Physics of Plasma