Organic Haze as a Biosignature in Anoxic Earth-like Atmospheres

Early Earth may have hosted a biologically-mediated global organic haze during the Archean eon (3.8-2.5 billion years ago). This haze would have significantly impacted multiple aspects of our planet, including its potential for habitability and its spectral appearance. Here, we model worlds with Archean-like levels of carbon dioxide orbiting the ancient sun and an M4V dwarf (GJ 876) and show that organic haze formation requires methane fluxes consistent with estimated Earth-like biological production rates. On planets with high fluxes of biogenic organic sulfur gases (CS2, OCS, CH3SH, and CH3SCH3), photochemistry involving these gases can drive haze formation at lower CH4/CO2 ratios than methane photochemistry alone. For a planet orbiting the sun, at 30x the modern organic sulfur gas flux, haze forms at a CH4/CO2 ratio 20% lower than at 1x the modern organic sulfur flux. For a planet orbiting the M4V star, the impact of organic sulfur gases is more pronounced: at 1x the modern Earth organic sulfur flux, a substantial haze forms at CH4/CO2 ~ 0.2, but at 30x the organic sulfur flux, the CH4/CO2 ratio needed to form haze decreases by a full order of magnitude. Detection of haze at an anomalously low CH4/CO2 ratio could suggest the influence of these biogenic sulfur gases, and therefore imply biological activity on an exoplanet. When these organic sulfur gases are not readily detectable in the spectrum of an Earth-like exoplanet, the thick organic haze they can help produce creates a very strong absorption feature at UV-blue wavelengths detectable in reflected light at a spectral resolution as low as 10. In direct imaging, constraining CH4 and CO2 concentrations will require higher spectral resolution, and R > 170 is needed to accurately resolve the structure of the CO2 feature at 1.57 {\mu}m, likely, the most accessible CO2 feature on an Archean-like exoplanet.Comment: accepted for publication in Astrobiolog

European Union - Reforms - Hungarian interests. What kind of European Union would we like?

The lecture deals with broad topics. First, it addresses some questions related to the current state of the EU integration regarding institutions and common policies. Second, it discusses the continued importance, the main results and hindering factors related to the Lisbon Programme, with a special emphasis on the educational system in Europe and Hungary. Third, the lecture deals with some possibilities in changing the EU’s rather limited external relation models to more flexible instruments

Discrete Model of Ideological Struggle Accounting for Migration

A discrete in time model of ideological competition is formulated taking into account population migration. The model is based on interactions between global populations of non-believers and followers of different ideologies. The complex dynamics of the attracting manifolds is investigated. Conversion from one ideology to another by means of (i) mass media influence and (ii) interpersonal relations is considered. Moreover a different birth rate is assumed for different ideologies, the rate being assumed to be positive for the reference population, made of initially non-believers. Ideological competition can happen in one or several regions in space. In the latter case, migration of non-believers and adepts is allowed; this leads to an enrichment of the ideological dynamics. Finally, the current ideological situation in the Arab countries and China is commented upon from the point of view of the presently developed mathematical model. The massive forced conversion by Ottoman Turks in the Balkans is briefly discussed.Comment: 24 pages, with 5 figures and 52 refs.; prepared for a Special issue of Advances in Complex System

Identifying Planetary Biosignature Impostors: Spectral Features of CO and O4 Resulting from Abiotic O2/O3 Production

O2 and O3 have been long considered the most robust individual biosignature gases in a planetary atmosphere, yet multiple mechanisms that may produce them in the absence of life have been described. However, these abiotic planetary mechanisms modify the environment in potentially identifiable ways. Here we briefly discuss two of the most detectable spectral discriminants for abiotic O2/O3: CO and O4. We produce the first explicit self-consistent simulations of these spectral discriminants as they may be seen by JWST. If JWST-NIRISS and/or NIRSpec observe CO (2.35, 4.6 um) in conjunction with CO2 (1.6, 2.0, 4.3 um) in the transmission spectrum of a terrestrial planet it could indicate robust CO2 photolysis and suggest that a future detection of O2 or O3 might not be biogenic. Strong O4 bands seen in transmission at 1.06 and 1.27 um could be diagnostic of a post-runaway O2-dominated atmosphere from massive H-escape. We find that for these false positive scenarios, CO at 2.35 um, CO2 at 2.0 and 4.3 um, and O4 at 1.27 um are all stronger features in transmission than O2/O3 and could be detected with SNRs $\gtrsim$ 3 for an Earth-size planet orbiting a nearby M dwarf star with as few as 10 transits, assuming photon-limited noise. O4 bands could also be sought in UV/VIS/NIR reflected light (at 0.345, 0.36, 0.38, 0.445, 0.475, 0.53, 0.57, 0.63, 1.06, and 1.27 um) by a next generation direct-imaging telescope such as LUVOIR/HDST or HabEx and would indicate an oxygen atmosphere too massive to be biologically produced.Comment: 7 pages, 4 figures, accepted to the Astrophysical Journal Letter

Experience of Using Simulation Technology and Analytics During the Ebola Crisis to Empower Frontline Health Workers and Improve the Integrity of Public Health Systems

Humanitarian Technology: Science, Systems and Global Impact 2016, HumTech2016 keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytics keywords: Analytic

A Machine-Checked Formalization of the Generic Model and the Random Oracle Model

Most approaches to the formal analyses of cryptographic protocols make the perfect cryptography assumption, i.e. the hypothese that there is no way to obtain knowledge about the plaintext pertaining to a ciphertext without knowing the key. Ideally, one would prefer to rely on a weaker hypothesis on the computational cost of gaining information about the plaintext pertaining to a ciphertext without knowing the key. Such a view is permitted by the Generic Model and the Random Oracle Model which provide non-standard computational models in which one may reason about the computational cost of breaking a cryptographic scheme. Using the proof assistant Coq, we provide a machine-checked account of the Generic Model and the Random Oracle Mode

Attacking Group Protocols by Refuting Incorrect Inductive Conjectures

Automated tools for finding attacks on flawed security protocols often fail to deal adequately with group protocols. This is because the abstractions made to improve performance on fixed 2 or 3 party protocols either preclude the modelling of group protocols all together, or permit modelling only in a fixed scenario, which can prevent attacks from being discovered. This paper describes Coral, a tool for finding counterexamples to incorrect inductive conjectures, which we have used to model protocols for both group key agreement and group key management, without any restrictions on the scenario. We will show how we used Coral to discover 6 previously unknown attacks on 3 group protocols

Gender Discrimination and Ageist Perceptions:

This report presents the findings from an ESF Objective 3 Project “Gender Discrimination and Ageist Perceptions”. The project is based at Liverpool John Moores University, in the Faculty of Education, Community and Leisure. Context Older age groups have consistently been undervalued and often discarded by employers, for being too old. They are now being encouraged to re-enter the workplace through schemes such as New Deal 50 plus and Pathways to Work, or to take up volunteering through the promotion of “Active Citizenship”. In addition, the concept of lifelong learning has been advocated by New Labour as an attempt to move away from the traditional notions of education, towards a vision in which education forms a lifelong process, which can be accessed at any time during the life course. Yet, despite the lower labour market attachment of the over fifties, people of this age group in higher education account for only around 1% of the student population. There is a variety of ways in which people approaching their mid life would, on the face of it, be able to access work, education or volunteering experiences. However, past research and current data suggest that there appear to be barriers to the take up of such opportunities. The Aim This study set out to investigate the experiences and perceptions of women and men aged over fifty and the organisations which impact upon their lives, in an effort to understand more fully the potential barriers this age group may face when accessing opportunities, employment, training or education. Background Gender disadvantages in the world of work have been well documented. Increasingly, age perceptions are thought to be a factor in older peoples’ access to employment and training opportunities. Data shows that the and only a tenth of those are on employer and government training programmes (TAEN, 2006). The demographic change, with more people living longer, coupled with low birth rates, is creating an expanding older population and fuelling oncerns over labour shortages. There is, therefore, an economic imperative to draw workers back into work via a variety of avenues. Despite over 70% of women now participating in the workforce, the employment patterns of men and women show that only 21% of women over 40 are in full-time employment, compared with 46% of men. Women have not had the same opportunities as men to build a career or to earn the equivalent of males due to their child-rearing and caring responsibilities, with many continuing to be concentrated in traditionally low paid sectors. The pay gap between some men and women is widening,despite the long history of legislation on equal pay. To compound the situation, older women are now said to be facing a double jeopardy of age and gender discrimination. Tackling discrimination has been at the heart of equal opportunities legislation designed to prevent unequal treatment regardless of gender,race and disability. The Sex Discrimination Act (SDA) and Equal Pay Act (EPA) both came into force in 1975. Each Act attempted to redress the inequalities suffered by (mainly) women in terms of employment and education. The Bill to establish the Commission for Equality and Human Rights (CEHR) received Royal Assent on 16th February 2006 and will provide an integrated approach to all forms of discrimination including that on the grounds of age