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

General overview of genetic research and experimentation on coconut varieties tolerant/resistant to lethal yellowing

The Lethal Yellowing (LY) disease is one of the main threats to coconut industry in many parts of Africa and the Caribbean. Planting resistant varieties has long been recognized as one of the most promising ways of controlling the disease. Considerable efforts have been devoted throughout the world to screening suitable varieties and have often involved international cooperation. It has proven to be a lengthy and difficult task. We present an overview of these efforts with special mention to Ghana, Jamaica and Mexico. Although no variety so far has been proven fully and permanently resistant, treating resistance level as a threshold trait makes it possible to demonstrate significant differences among varieties, which can be exploited effectively to make genetic improvement a component of an integrated control strategy. Based on past experience, we make a few suggestions to increase the diversity of resistance sources and increase the level and the sustainability of resistance to LY in coconut. (Résumé d'auteur

General methodology for exergy balance in ProSimPlus® process simulator

This paper presents a general methodology for exergy balance in chemical and thermal processes integrated in ProSimPlus® as a well-adopted process simulator for energy efficiency analysis. In this work, as well as using the general expressions for heat and work streams, all of exergy balance is presented within only one software in order to fully automate exergy analysis. In addition, after exergy balance, the essential elements such as source of irreversibility for exergy analysis are presented to help the user for modifications on either process or utility system. The applicability of the proposed methodology in ProSimPlus® is shown through a simple scheme of Natural Gas Liquids (NGL) recovery process and its steam utility system. The methodology does not only provide the user with necessary exergetic criteria to pinpoint the source of exergy losses, it also helps the user to find the way to reduce the exergy losses. These features of the proposed exergy calculator make it preferable for its implementation in ProSimPlus® to define the most realistic and profitable retrofit projects on the existing chemical and thermal plants

“Give Every Listener What He Wants and Even a Little More”

Walter Benjamin seems to be one of the few philosophers to have theorised on the radio, and probably the only one to have produced such a variety of experiments on air. Between 1929 and 1933, he realised more than 95 radio programmes: lectures, readings, radio plays, interviews and radio stories for children. These different radio works allow Benjamin to relate to a new audience who has no prior knowledge of his essays. His radio thoughts and practices give listeners the means to change the way they use the media and the radio in particularWalter Benjamin semble être l’un des rares philosophes à avoir tenté de théoriser la radio et probablement le seul qui ait produit et expérimenté de manière aussi intensive et créative ce médium. Entre 1929 et 1933, il réalise près de quatre-vingt quinze émissions: conférences, lectures, Hörspiele, entretiens et contes radiophoniques pour enfants. Ces différents travaux pour la radio offre à Benjamin la possibilité de se confronter à un public inédit qui ne connaît pas ses essais. Penser et pratiquer la radio pour donner aux auditeurs les moyens de changer leur propre usage des media et en particulier de la radio.Walter Benjamin parece ser uno de los pocos filósofos en formular ideas sobre la radio y, probablemente, el único que haya hecho variados experimentos en este medio. Entre 1929 y 1933, Benjamin realiza más de 95 programas de radio: conferencias, lecturas, radioteatro, entrevistas y cuentos radiofónicos para niños. Esta diversidad de trabajos radiales le permite confrontarse a una audiencia inédita que desconoce sus ensayos. Se trata de un pensamiento y una práctica de la radio que ofrece a los oyentes diferentes posibilidades sobre cómo usar los medios de comunicación

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