A modelling perspective on precipitationin the Indus River Basin: from synopticto Holocene variability

The Indus River civilisation was the first urban society in South Asia. Its demise, ca. 4000 years ago, might have been caused by environmental factors, such as recurrent drought conditions. Yet, palaeoclimate archives present a fragmented picture of the climate at that time. This thesis explores the potential value of global climate models to further interpret the archaeological context. Precipitation variability is investigated at various timescales due to their different impact on human societies and their importance in the climate system: the synoptic scale, the seasonal cycle, the inter-annual to multi-decadal variability, and the multi-millennial Holocene trends. The precipitation from several climate model simulations is evaluated at each of these timescales. Indus River Basin precipitation is first explored in observational datasets. This study highlights the quality of ERA5 reanalysis, which is used as a reference in the subsequent chapters. Statistical tools show that more than 80\% of the precipitation in the Upper Indus Basin is related to cross-barrier moisture transport along the Himalayan foothills. The climate models analysed (IPSL-CM6-A, MRI-ESM2-0 and GISS-E2-1-G) generally reproduce this process well, but the seasonality of cross-barrier moisture transport is biased, resulting in precipitation biases: the main wet season, the summer monsoon, is shorter and significantly dryer, while the second wet season, in winter, is longer and more active. The link between winter precipitation, cross-barrier moisture transport and Western Disturbances is further explored, first in ERA5 and then compared to IPSL-CM6-A model output. Sub-daily resolution is needed to determine the origin of the positive precipitation bias in winter. This bias is related to differences in the atmospheric circulation associated with Western Disturbances. The stronger Subtropical Westerly Jet is also key to understand the precipitation overestimation. Centennial to millennial-scale precipitation variability is more difficult to evaluate due to the short length of observations and the paucity of climate records, but the results suggest that inter-annual variability in the IPSL climate model family is overly dominated by atmosphere-only processes, with a potentially large impact of the precipitation response to external forcings. In addition to biases in the representation of mean precipitation and synoptic to inter-annual variability, climate models are also limited by the representation of other internal processes such as ocean circulation, and vegetation-dust aerosols, as well as by the uncertainty in some external forcings such as volcanic eruptions and the solar activity. Hence, at the present state, past-climate simulations do not provide the nuanced information of precipitation changes and variability that is needed to understand impact of precipitation variability on archaeological contexts, and will not do so until significant breakthroughs are achieved. Nevertheless, climate models remain a powerful tool for climatologists to investigate large-scale processes that can eventually better characterise climate variability.This research was carried out as part of the TwoRains project, which is supported by funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant 648609)

THE STANFORD HEART DISEASE PREVENTION PROGRAM

This afternoon I want to tell you about the results of a major study we have been doing as a part of the Stanford Heart Disease Prevention Program. The Stanford Heart Disease Prevention Program is an interdisciplinary project directed by Dr. John W. Farquhar, Professor of Medicine at Stanford University and I am co-director. This paper was really co-authored by fifteen people as part of an interdisciplinary team. With a group of different people like this, we had to spend a significant amount of time trying to teach each other our respective professional languages. Initially, communication within our group was a terrible problem. We have worked through this stage and now we have, among other things, a post doctoral training program in which both young M.D.\u27s or young Ph.D.\u27s can become involved in cardiovascular work in its various aspects. This project has a psychlogical component, a pathological component, a biochemical component, a behavioral component and a communications component. This afternoon I want to talk about our major community study. The gradual rise in age-adjusted cardiovascular disease mortality in industrialized countries has considerably diminished what would otherwise be seen as striking gains in health in the last 75 years. These gains, due primarily to increased and improved practices in modern medicine, have occurred mainly in the prevention of infant and early childhood mortality and in the improvement in crisis intervention techniques after the onset of disease symptoms. Unfortunately, much cardiovascular disease is apparently unresponsive to anything but pre-crisis preventive intervention. The U.S. male who has survived to age 45 now has only a slightly greater life expectancy than did his forebear in 1900. Table I shows comparative rates of coronary heart disease, treating the U.S. rate as base 100. That is not the actual figure but shows, by comparison, for example, that Japan and Greece and Yugoslavia have considerably lower rates and that only Finland is worse off than we are

Impact of reanalysis boundary conditions on downscaled Atlantic hurricane activity

Climate models are capable of producing features similar to tropical cyclones, but typically display strong biases for many of the storm physical characteristics due to their relatively coarse resolution compared to the size of the storms themselves. One strategy that has been adopted to circumvent this limitation is through the use of a hybrid downscaling technique, wherein a large set of synthetic tracks are created by seeding disturbances in the large-scale environment. Here, we evaluate the ability of this technique at reproducing many of the characteristics of the recent North Atlantic hurricane activity as well as its sensitivity to the choice of the reanalysis dataset used as boundary conditions. In particular, we show that the geographical and intensity distributions are well reproduced, but that the technique has difficulty capturing the large difference in activity observed between the most recent active and quiescent phase. Although the signal is somewhat reduced compared to observation, the technique also detects a significant decrease in the intensification rate of hurricanes near the coastal US during the active phase compared to the quiescent phase. Finally, the influence of the El Niño Southern Oscillation on hurricane activity is generally well captured as well, but the technique fails to reproduce the increase in activity over the western part of the basin during Modoki El Niños.We would like to thank NOAA’s National Centers for Environmental Information for making the IBTrACS data available. JPB and LPC would like to acknowledge the financial support from the Ministerio de Economa y Competitividad (MINECO; Project GL2014-55764-R). LPC’s contract is co-financed by the MINECO under Juan de la Cierva Incorporacin postdoctoral fellowship number IJCI-2015-23367. MB would like to acknowledge financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada. Finally, we are grateful to Kerry Emanuel for providing the data as well as some useful feedback, and two anonymous reviewers for their helpful comments.Peer ReviewedPostprint (published version

HIx system thermodynamic model for hydrogen production by the sulfur-iodine cycle

The HIx ternary system (H2O – HI – I2) is the latent source of hydrogen for the Sulfur – Iodine thermo-chemical cycle. After analysis of the literature data and models, a homogeneous approach with the Peng-Robinson equation of state used for both the vapor and liquid phase fugacity calculations is proposed for the first time to describe the phase equilibrium of this system. The MHV2 mixing rule is used, with UNIQUAC activity coefficient model combined with of hydrogen iodide solvation by water. This approach is theoretically consistent for HIx separation processes operating above HI critical temperature. Model estimation is done on selected literature vapor – liquid, liquid – liquid, vapor – liquid – liquid and solid – liquid equilibrium data for the ternary system and the three binaries subsystems. Validation is done on the remaining literature data. Results agree well with the published data, but more experimental effort is needed to improve modeling of the HIx system

Bunsen section thermodynamic model for hydrogen production by the sulfur-Iodine cycle

A model for the Bunsen section of the Sulfur – Iodine thermo-chemical cycle is proposed, where sulfur dioxide reacts with excess water and iodine to produce two demixing liquid aqueous phases (H2SO4 rich and HI rich) in equilibrium. Considering the mild temperature and pressure conditions, the UNIQUAC activity coefficient model combined with Engels’ solvation model is used. The complete model is discussed, with HI solvation by water and by iodine as well as H2SO4 solvation by water, leading to a very high complexity with almost hundred parameters to be estimated from experimental data. Taking into account the water excess, a successful reduced model with only 15 parameters is proposed after defining new apparent species. Acids total dissociation and total H+ solvation by water are the main assumptions. Results show a good agreement with published experimental data between 25 °C and 120 °C

Thermodynamic modeling of the condensable fraction of a gaseous effluent from lignocellulosic biomass torrefaction

The condensable fraction of the gaseous effluent from the torrefaction process of wood is a complex mixture of more than one hundred oxygenated species (alcohols, acids, aldehydes, ketones, furans, phenolic, gaïacols and sugars) diluted in water where some of them are likely to react. This effluent is currently burnt to provide energy but it could be valorized as bio-sourced chemicals. To recover target products like acetic acid, glycolaldehyde, furfural and eugenol a first step of thermodynamic modeling of this complex mixture is required to be able to propose different strategies of separation-purification. This was done here by coupling the UNIQUAC model with chemical equilibria involved in the reactive mixture. Binary interaction parameters were identified using vapor–liquid equilibria data from the literature. The predicted results are in good agreement with the experimental data of systems containing water, methanol, formaldehyde, acetic acid, formic acid, propionic acid, furfural and furfuryl alcohol, main components of the considered mixture and their associated reaction products

modulation of inflammation related genes in the cornea of a mouse model of dry eye upon treatment with cyclosporine eye drops

ABSTRACTPurpose/Aim: Inflammation is recognized as playing an etiological role in dry eye disease. This study aimed to assess the efficacy of various topical cyclosporine A (CsA) formulations on co..