Mathematical Model of a Cell Size Checkpoint

How cells regulate their size from one generation to the next has remained an enigma for decades. Recently, a molecular mechanism that links cell size and cell cycle was proposed in fission yeast. This mechanism involves changes in the spatial cellular distribution of two proteins, Pom1 and Cdr2, as the cell grows. Pom1 inhibits Cdr2 while Cdr2 promotes the G2 → M transition. Cdr2 is localized in the middle cell region (midcell) whereas the concentration of Pom1 is highest at the cell tips and declines towards the midcell. In short cells, Pom1 efficiently inhibits Cdr2. However, as cells grow, the Pom1 concentration at midcell decreases such that Cdr2 becomes activated at some critical size. In this study, the chemistry of Pom1 and Cdr2 was modeled using a deterministic reaction-diffusion-convection system interacting with a deterministic model describing microtubule dynamics. Simulations mimicked experimental data from wild-type (WT) fission yeast growing at normal and reduced rates; they also mimicked the behavior of a Pom1 overexpression mutant and WT yeast exposed to a microtubule depolymerizing drug. A mechanism linking cell size and cell cycle, involving the downstream action of Cdr2 on Wee1 phosphorylation, is proposed

How to Be Fair in Prioritizing Support in the Aftermath of Disasters: Pakistan's Housing Reconstruction Challenges Following the 2010 Flood Disaster

In 2010, Pakistan was hit by the worst flood in the century. A total of 1.6 million homes were damaged and 0.9 million utterly destroyed or washed away (World Bank, 2010), meaning that more than 5 million people were left homeless. This is equivalent to a quarter of the Australian population. The task of rebuilding was, and always is, a formidable one for cash-constrained developing countries like Pakistan. This holds both for individual households who have lost their home and for the government that might wish to help them. Because resources and funding are limited, government must set priorities and often make hard choices. If help is to be offered to the victims, what is to be rebuilt first and what later? Who is to be helped first and whom later? Should the amount of help differ between victims and if so, how

Consumer Behavior in Building Energy Use

Economic theory of customer preference describes consumer behavior as a \u201cset of activities prospective customers undertake in searching, selecting, valuing, assessing, supplying and using of products and services in order to satisfy their needs and desires\u201d (\u10cavo\u161ki and Markov\uedc 2015). When it comes to research in the field of energy consumption and energy efficiency, there is a lack of common understanding of what consumer behavior is, since it is strongly related to the technical, economic, sociological, and psychological models applied to understand how and why people perform energy-related actions, and to the disciplines which investigate these actions. Hence, consumer behavior might be referred, among others, as occupant behavior and energy behavior. Occupant behavior has been referred as a set of \u201cobservable actions or reactions of a person in response to external or internal stimuli, or respectively actions or reactions of a person to adapt to ambient environmental conditions such as temperature, indoor air quality or sunlight\u201d (International Energy Agency EBCP 2013). However, this definition does not take into account individual attitudes and reasons which lead to a specific action, which instead have been intensively studied in social sciences. Energy behavior has been defined as \u201call human actions that affect the way that fuels (electricity, gas, petroleum, coal, etc.) are used to achieve desired services, including the acquisition or disposal of energy-related technologies and materials, the ways in which these are used, and the mental processes that relate to these actions\u201d (International Energy Agency DSM Energy Efficiency 2014). Energy behavior is the one leading to end-use energy consumption, incorporating two implicit dimensions: the behavior itself and the associated energy consumption (Lopes et al. 2012). Rather than agreeing on unique terms and definitions, this chapter aims at providing an overview of the scope, policy implications, and characteristics of the consumer behavior in building energy use, focusing in particular on the household behavior in the residential sector. To the purpose of this work, all the terms above are assumed to embed energy consumption as subject of investigation; therefore, consumer behavior, user behavior, and occupant behavior are used indifferently