Scientific discovery as a combinatorial optimisation problem: How best to navigate the landscape of possible experiments?

A considerable number of areas of bioscience, including gene and drug discovery, metabolic engineering for the biotechnological improvement of organisms, and the processes of natural and directed evolution, are best viewed in terms of a ‘landscape’ representing a large search space of possible solutions or experiments populated by a considerably smaller number of actual solutions that then emerge. This is what makes these problems ‘hard’, but as such these are to be seen as combinatorial optimisation problems that are best attacked by heuristic methods known from that field. Such landscapes, which may also represent or include multiple objectives, are effectively modelled in silico, with modern active learning algorithms such as those based on Darwinian evolution providing guidance, using existing knowledge, as to what is the ‘best’ experiment to do next. An awareness, and the application, of these methods can thereby enhance the scientific discovery process considerably. This analysis fits comfortably with an emerging epistemology that sees scientific reasoning, the search for solutions, and scientific discovery as Bayesian processes

Contrasting impacts of heat stress on violent and nonviolent robbery in Beijing, China

Previous studies investigating the relation between heat stress and crime incidents often focus on violent crimes. In this study, the impacts of heat stress on two types of robbery (violent and nonviolent) in China are compared using crime statistics collected in Beijing and heat stress indices that consider the combined effects of temperature and humidity. The results indicate that the abrupt change in the trend of robbery rates is affected by the 2008 Beijing Olympic Games. The nonviolent robbery rates have a more pronounced seasonality and are better correlated with heat stress at daily scales, especially during the period from 2009 to 2014 when no trend exists. The results also demonstrate that both violent and nonviolent robbery rates significantly increase with heat stress in spring. The nonviolent robbery rates also significantly increase with heat stress in summer. The influence of heat stress on violent robbery rate is more complicated and nonlinear

The international politics of geoengineering: The feasibility of Plan B for tackling climate change

Geoengineering technologies aim to make large-scale and deliberate interventions in the climate system possible. A typical framing is that researchers are exploring a ‘Plan B’ in case mitigation fails to avert dangerous climate change. Some options are thought to have the potential to alter the politics of climate change dramatically, yet in evaluating whether they might ultimately reduce climate risks, their political and security implications have so far not been given adequate prominence. This article puts forward what it calls the ‘security hazard’ and argues that this could be a crucial factor in determining whether a technology is able, ultimately, to reduce climate risks. Ideas about global governance of geoengineering rely on heroic assumptions about state rationality and a generally pacific international system. Moreover, if in a climate engineered world weather events become something certain states can be made directly responsible for, this may also negatively affect prospects for ‘Plan A’, i.e. an effective global agreement on mitigation

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

2012 BBESTs Rio Grande, Rio Grande estuary, and Lower Laguna Madre environmental flows recommendations reports

Section 11.02362(b)(3) of Senate Bill 3 (SB3) as enacted by the 80th Texas Legislature in 2007 identifies the river basin and bay system consisting of the Texas portions of the Rio Grande, the Rio Grande estuary, and the Lower Laguna Madre (collectively the Texas Rio Grande system) as a priority system for the purpose of developing environmental flow regime recommendations and adopting environmental flow standards. This report presents the findings and recommendations of the SB3 Rio Grande Basin and Bay Expert Science Team (BBEST) regarding these environmental flow requirements. Because of distinct differences in the aquatic environments across the Texas Rio Grande system, the associated different needs with regard to protecting environmental flows, and the unique water rights, water availability and institutional aspects of this system, this SB3 work has been conducted by two subgroups of the BBEST, a Lower Rio Grande BBEST and an Upper Rio Grande BBEST