Amplification of Cosmological Inhomogeneities by the QCD Transition

The cosmological QCD transition affects primordial density perturbations. If the QCD transition is first order, the sound speed vanishes during the transition and density perturbations fall freely. For scales below the Hubble radius at the transition the primordial Harrison-Zel'dovich spectrum of density fluctuations develops large peaks and dips. These peaks grow with wave number for both the hadron-photon-lepton fluid and for cold dark matter. At the horizon scale the enhancement is small. This by itself does not lead to the formation of black holes at the QCD transition. The peaks in the hadron-photon-lepton fluid are wiped out during neutrino decoupling. For cold dark matter that is kinetically decoupled at the QCD transition (e.g., axions or primordial black holes) these peaks lead to the formation of CDM clumps of masses $10^{-20} M_\odot< M_{\rm clump} < 10^{-10} M_\odot$.Comment: 39 pages, 10 figures, RevTeX; (1) ETH Zuerich, (2) Univ. Frankfurt; improved presentation of 'Introduction' and 'Collisional Damping at Neutrino Decoupling', results unchanged; accepted for publication in Phys. Rev.

"Cella promptuaria sive fossa nivalis"? Überlegungen zur Primärfunktion von Schacht MR 6/MR 32 in der Region 17C der Unterstadt von Augusta Raurica

Anlässlich der Lehrgrabung «Kaiseraugst-Auf der Wacht» in der westlichen Unterstadt von Augusta Raurica (Region 17C) wurden in den Jahren 2011–2013 mehrere, zum Teil über 4 m tiefe Schächte entdeckt – so unter anderem der im ausgehenden 1. oder frühen 2. Jahrhundert errichtete und um die Mitte des 2. Jahrhunderts wieder aufgegebene und mit Latrinensedimenten und anderen Abfällen verfüllte Schacht MR 6/MR 32. Im vorliegenden Aufsatz wird der Frage nach der primären Funktion des 4,2 m tiefen, trocken gemauerten Schachts nachgegangen, da sich diese im Rahmen der Auswertung der archäo(bio)logischen Quellen nicht mit hinreichender Sicherheit eruieren liess (vgl. Ammann/Schwarz 2017 [in diesem Band]). Denkbar ist einerseits eine Verwendung des Schachts als cella promptuaria, also zur Einlagerung von Flüssigkeiten und von feuchtigkeitsresistenten Lebensmitteln, namentlich von Obst und Gemüse. Analogien zu (früh-)neuzeitlichen Befun-den, die nach Aussage der zeitgenössischen Quellen nachweislich zur Bevorratung von Schnee und Eis gedient haben, lassen jedoch andererseits auch eine Nutzung des Schachts als fossa nivalis, also als Schnee- und/oder Eiskeller, als denkbar erscheinen. Gestützt wird diese Vermutung in erster Linie durch die antiken Schriftquellen. Obschon sich die antiken Testimonien zur Verwendung von Schnee und Eis mehrheitlich auf die ingeniosa luxuria (erfindungsreiche Genusssucht) der gesellschaftlichen und politischen Elite des imperium Romanum bzw. der urbs Roma beziehen, kann davon ausgegangen werden, dass Schnee und Eis auch hierzulande gezielt bevorratet und als Kühlmittel verwendet wurden. Die Analyse der antiken Textquellen sowie ethnografische Vergleiche zeigen jedenfalls, dass als Abnehmer nicht nur Liebhaber von gekühltem Wein oder von Eis- und Schneebädern infrage kommen, sondern beispielsweise auch Austernhändler, Käseproduzenten, Metzger und andere Lebensmittelproduzenten

Political Temporalities of Youth

Non

Intergenerational transmission of trajectories of suffering in precarious environments: researching the younger generations' strategies of reinterpretation

"This article discusses some pivotal questions regarding processes of the intergenerational transmission of trajectories of suffering in precarious places: to what extent can such processes provide resources that foster agency, and to what extent do they rather constitute barriers to living one's own life? How much do intergenerational relations allow for certain reinterpretations while discouraging or inhibiting others? Which reinterpretations of the older generations' experiences appear legitimate in certain contexts, and which are rebuked by one's social environment? In order to pursue these questions we present analyses of two very different cases that are based on two forms of data material - the life story of Emma, a woman in her 50s, and ethno-analytic group interviews with adolescents aged 14 to 20. Both cases are embedded in very different regional and political contexts: the former, in the French system of fostering institutions, and the latter a Palestinian refugee camp in the West Bank. Both constitute, however, cases of intergenerational transmission of trajectories of suffering. One objective of this article is to illustrate how the contrasting of such cases across different kinds of data and contexts can be heuristically useful for methodologically gauging the spectrum of the ubiquitous and sometimes paradoxical phenomena of intergenerational transmission, in order to further develop its conceptualization." (author's abstract

Osmotic diuresis due to urea as the cause of hypernatraemia in critically ill patients

Background. Hypernatraemia is common in critically ill patients and has been shown to be an independent predictor of mortality. Osmotic urea diuresis can cause hypernatraemia due to significant water losses but is often not diagnosed. Free water clearance (FWC) and electrolyte free water clearance (EFWC) were proposed to quantify renal water handling. We aimed to (i) identify patients with hypernatraemia due to osmotic urea diuresis and (ii) investigate whether FWC and EFWC are helpful in identifying renal loss of free water. Methods. In this retrospective study, we screened a registry for patients, who experienced intensive care unit (ICU)-acquired hypernatraemia. Among them, patients with hypernatraemia due to osmotic urea diuresis were detected by a case-by-case review. Total fluid and electrolyte balances together with FWC and EFWC were calculated for days of rising serum sodium and stable serum sodium. Results. We identified seven patients (10% of patients with ICU-acquired hypernatraemia) with osmotic diuresis due to urea. All patients were intubated during development of hypernatraemia and received enteral nutrition. The median highest serum sodium level of 153 mmol (Q1: 151-Q3: 155 mmol/L) was reached after a 5-day period of rise in serum sodium. During this period, FWC was −904 mL/day (Q1: −1574-Q3: −572), indicating renal water retention, while EFWC was 1419 mL/day (Q1: 1052-Q3: 1923), showing renal water loss. While FWC did not differ between time of stable serum sodium and development of hypernatraemia, EFWC was significantly higher during rise in serum sodium. Conclusion. Osmotic urea diuresis is a common cause of hypernatraemia in the ICU. EFWC was useful in the differential diagnosis of polyuria during rising serum sodium levels, while FWC was misleadin