The economics of debt clearing mechanisms

We examine the evolution of decentralized clearinghouse mechanisms from the 13th to the 18th century; in particular, we explore the clearing of non- or limitedtradable debts like bills of exchange. We construct a theoretical model of these clearinghouse mechanisms, similar to the models in the theoretical matching literature, and show that specific decentralized multilateral clearing algorithms known as rescontre, skontrieren or virement des parties used by merchants were efficient in specific historical contexts. We can explain both the evolutionary self-organizing emergence of late medieval and early modern fairs, and its robustness during the 17th and 18th century

Should I Stay or Should I Go: Stellar Wind Retention and Expulsion in Massive Star Clusters

Mass and energy injection throughout the lifetime of a star cluster contributes to the gas reservoir available for subsequent episodes of star formation and the feedback energy budget responsible for ejecting material from the cluster. In addition, mass processed in stellar interiors and ejected as winds has the potential to augment the abundance ratios of currently forming stars, or stars which form at a later time from a retained gas reservoir. Here we present hydrodynamical simulations that explore a wide range of cluster masses, compactnesses, metallicities and stellar population age combinations in order to determine the range of parameter space conducive to stellar wind retention or wind powered gas expulsion in star clusters. We discuss the effects of the stellar wind prescription on retention and expulsion effectiveness, using MESA stellar evolutionary models as a test bed for exploring how the amounts of wind retention/expulsion depend upon the amount of mixing between the winds from stars of different masses and ages. We conclude by summarizing some implications for gas retention and expulsion in a variety of compact ($\sigma_v \gtrsim 20 \, {\rm km s^{-1}}$) star clusters including young massive star clusters ($10^5 \lesssim M/M_\odot \lesssim 10^7$, $age \lesssim 500$~Myrs), intermediate age clusters ($10^5 \lesssim M/M_\odot \lesssim 10^7$, $age \approx 1-4$~Gyrs), and globular clusters ($10^5 \lesssim M/M_\odot \lesssim 10^7$, $age \gtrsim 10$~Gyrs).Comment: 18 pages, 14 figures, version resubmitted to MNRAS after minor referee comment

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Fat mass accumulation during childhood determines insulin sensitivity in early adulthood

Background/Objectives: Low birth weight and postnatal catch-up growth have been associated with an increased risk for diabetes mellitus type II (DMII). We evaluated the contribution of birth and adult size, body composition, and waist-to-hip ratio to DMII risk factors in young adulthood. Methods: In a group of 136 young adults, aged 18-24 yr, insulin sensitivity and disposition index were determined by frequent sampling iv glucose tolerance test. The association of clinical parameters with these variables was analyzed with multiple regression modeling. In addition, differences in insulin sensitivity and disposition index, a measure for β-cell function, were analyzed in four subgroups, young adults either born small for gestational age SGA with short stature (n = 25) or SGA with catch-up growth (n = 23) or born appropriate for gestational age with idiopathic short stature (n = 23) or with normal stature (controls) (n = 26). Results: Fat mass was the only significant predictor of insulin sensitivity, whereas birth length and birth weight were not significant. After correction for age, gender, and adult body size, insulin sensitivity was significantly lower in subjects born SGA with catch-up growth compared with controls. None of the variables had a significant influence on disposition index, and there was no significant difference in disposition index between the subgroups. Conclusions: Our data show that a higher body fat mass at 21 yr is associated with reduced insulin sensitivity, independent of birth size. These findings have important implications for public health practice. Copyrigh