Minsky machines and algorithmic problems

This is a survey of using Minsky machines to study algorithmic problems in semigroups, groups and other algebraic systems.Comment: 19 page

Analysis of airplane boarding via space-time geometry and random matrix theory

We show that airplane boarding can be asymptotically modeled by 2-dimensional Lorentzian geometry. Boarding time is given by the maximal proper time among curves in the model. Discrepancies between the model and simulation results are closely related to random matrix theory. We then show how such models can be used to explain why some commonly practiced airline boarding policies are ineffective and even detrimental.Comment: 4 page

Conclusions

What is the function of parent–child argumentation? This chapter intends to answer the main research question that has guided the study presented in this volume and open a discussion for future research on this topic. In the first part, the chapter provides a detailed overview of the main findings of the analysis of parent–child argumentative discussions during mealtime. The role played by parents and children in the inception and development of argumentation, and the types of conclusions of their argumentative discussions are described. Subsequently, two educational targets achieved by parents and children through their argumentative interactions are presented and critically discussed. In the last part, new open questions that should guide future investigation to expand our knowledge of the role and function of argumentation between parents and children are proposed

How do I know if I’ve improved my continental scale flood early warning system?

Flood early warning systems mitigate damages and loss of life and are an economically efficient way of enhancing disaster resilience. The use of continental scale flood early warning systems is rapidly growing. The European Flood Awareness System (EFAS) is a pan-European flood early warning system forced by a multi-model ensemble of numerical weather predictions. Responses to scientific and technical changes can be complex in these computationally expensive continental scale systems, and improvements need to be tested by evaluating runs of the whole system. It is demonstrated here that forecast skill is not correlated with the value of warnings. In order to tell if the system has been improved an evaluation strategy is required that considers both forecast skill and warning value. The combination of a multi-forcing ensemble of EFAS flood forecasts is evaluated with a new skill-value strategy. The full multi-forcing ensemble is recommended for operational forecasting, but, there are spatial variations in the optimal forecast combination. Results indicate that optimizing forecasts based on value rather than skill alters the optimal forcing combination and the forecast performance. Also indicated is that model diversity and ensemble size are both important in achieving best overall performance. The use of several evaluation measures that consider both skill and value is strongly recommended when considering improvements to early warning systems

Вызовы новой инвестиционной политики: защита и поощрение капиталовложений

The study aims to analyze key aspects of the new emerging investment policy, which sets the priority for private investment protection and promotion. The relevance of the study is due to the search for new, nonbudget, funding sources for implementing large-scale national tasks and large infrastructure projects. Attracting private capital within changing global investment becomes an important task for national governments, and therefore requires a departure from investment protectionism to investment protection and promotion. Due to the methods of theoretical (analysis, synthesis, generalization, historical method) and empirical (comparison, measurement) research, the authors managed to reveal the main economic determinants and components of the national investment climate that contribute to attracting foreign capital; to systematize the key measures of investment policy; to identify trends in the dynamics of global flows of foreign direct investment. As a result, the authors established key principles and criteria for the new investment policy of sustainable development, as well as identified contemporary models of the new investment policy. These include a model for stimulating the development of individual priority economic activities; a model for improving the technological level of national industries; a model for creating new integrated meta-industries. The authors focus on reforming the investment regime in the Russian Federation. The new legislation provides for the possibility to conclude an investment protection and promotion agreement with private investors based on “a stabilization clause”. Thus, investors implementing large-scale investment projects will be subject to new rules that will establish the conditions at the time of the agreement, in particular, tax and customs policies. According to the authors, such agreements will improve the quality of the investment climate in the Russian Federation.Цель исследования состоит в анализе ключевых аспектов формирующейся новой инвестиционной политики, которая своей приоритетной задачей ставит защиту и поощрение частных инвестиций. Актуальность исследования обусловлена поиском новых, исключая бюджетные, источников финансирования реализации масштабных национальных задач и крупных инфраструктурных проектов. Привлечение частного капитала в условиях изменения глобального инвестиционного ландшафта становится важной задачей национальных правительств, в связи с чем необходим отход от инвестиционного протекционизма в сторону защиты и поощрения капиталовложений. Использование методов теоретического (анализ, синтез, обобщение, исторический метод) и эмпирического (сравнение, измерение) исследования позволило авторам раскрыть основные экономические детерминанты и составляющие национального инвестиционного климата, способствующие привлечению иностранного капитала; систематизировать основные меры инвестиционной политики; выявить тенденции в динамике глобальных потоков прямых иностранных инвестиций. В результате авторы установили ключевые принципы, критерии построения новой инвестиционной политики в целях устойчивого развития, а также выделили современные модели новой инвестиционной политики. К ним относятся: модель стимулирования развития отдельных приоритетных видов экономической деятельности; модель повышения технологического уровня отраслей национальной промышленности; модель создания новых комплексных метаотраслей. Акцент сделан на реформировании инвестиционного режима в Российской Федерации. Новое законодательство предусматривает возможность заключения соглашения с частными инвесторами о защите и поощрении капиталовложений, в основе которого лежит «стабилизационная оговорка». Таким образом, на инвесторов, реализующих крупные инвестиционные проекты, будут распространяться новые правила, которые позволят зафиксировать действующие на момент заключения соглашения условия, в частности, налоговой и таможенной политики. Заключение подобного рода соглашений поможет, по мнению авторов, повысить качество инвестиционного климата в Российской Федерации

Newly identified nematodes from Mono Lake exhibit extreme arsenic resistance

Extremophiles have much to reveal about the biology of resilience, yet their study is limited by sampling and culturing difficulties [1, 2, 3]. The broad success and small size of nematodes make them advantageous for tackling these problems [4, 5, 6]. We investigated the arsenic-rich, alkaline, and hypersaline Mono Lake (CA, US) [7, 8, 9] for extremophile nematodes. Though Mono Lake has previously been described to contain only two animal species (brine shrimp and alkali flies) in its water and sediments [10], we report the discovery of eight nematode species from the lake, including microbe grazers, parasites, and predators. Thus, nematodes are the dominant animals of Mono Lake in species richness. Phylogenetic analysis suggests that the nematodes originated from multiple colonization events, which is striking, given the young history of extreme conditions at Mono Lake [7, 11]. One species, Auanema sp., is new, culturable, and survives 500 times the human lethal dose of arsenic. Comparisons to two non-extremophile sister species [12] reveal that arsenic resistance is a common feature of the genus and a preadaptive trait that likely allowed Auanema to inhabit Mono Lake. This preadaptation may be partly explained by a variant in the gene dbt-1 shared with some Caenorhabditis elegans natural populations and known to confer arsenic resistance [13]. Our findings expand Mono Lake’s ecosystem from two known animal species to ten, and they provide a new system for studying arsenic resistance. The dominance of nematodes in Mono Lake and other extreme environments and our findings of preadaptation to arsenic raise the intriguing possibility that nematodes are widely pre-adapted to be extremophiles

Floral temperature and optimal foraging: is heat a feasible floral reward for pollinators?

As well as nutritional rewards, some plants also reward ectothermic pollinators with warmth. Bumble bees have some control over their temperature, but have been shown to forage at warmer flowers when given a choice, suggesting that there is some advantage to them of foraging at warm flowers (such as reducing the energy required to raise their body to flight temperature before leaving the flower). We describe a model that considers how a heat reward affects the foraging behaviour in a thermogenic central-place forager (such as a bumble bee). We show that although the pollinator should spend a longer time on individual flowers if they are warm, the increase in total visit time is likely to be small. The pollinator's net rate of energy gain will be increased by landing on warmer flowers. Therefore, if a plant provides a heat reward, it could reduce the amount of nectar it produces, whilst still providing its pollinator with the same net rate of gain. We suggest how heat rewards may link with plant life history strategies

Correlations and forecast of death tolls in the Syrian conflict

The Syrian armed conflict has been ongoing since 2011 and has already caused thousands of deaths. The analysis of death tolls helps to understand the dynamics of the conflict and to better allocate resources and aid to the affected areas. In this article, we use information on the daily number of deaths to study temporal and spatial correlations in the data, and exploit this information to forecast events of deaths. We found that the number of violent deaths per day in Syria varies more widely than that in England in which non-violent deaths dominate. We have identified strong positive auto-correlations in Syrian cities and non-trivial cross-correlations across some of them. The results indicate synchronization in the number of deaths at different times and locations, suggesting respectively that local attacks are followed by more attacks at subsequent days and that coordinated attacks may also take place across different locations. Thus the analysis of high temporal resolution data across multiple cities makes it possible to infer attack strategies, warn potential occurrence of future events, and hopefully avoid further deaths