Future Developments in Geographical Agent‐Based Models: Challenges and Opportunities

Despite reaching a point of acceptance as a research tool across the geographical and social sciences, there remain significant methodological challenges for agent‐based models. These include recognizing and simulating emergent phenomena, agent representation, construction of behavioral rules, and calibration and validation. While advances in individual‐level data and computing power have opened up new research avenues, they have also brought with them a new set of challenges. This article reviews some of the challenges that the field has faced, the opportunities available to advance the state‐of‐the‐art, and the outlook for the field over the next decade. We argue that although agent‐based models continue to have enormous promise as a means of developing dynamic spatial simulations, the field needs to fully embrace the potential offered by approaches from machine learning to allow us to fully broaden and deepen our understanding of geographical systems

Association between individual level characteristics and take-up of a Minimum Income Guarantee for Pensioners: Panel Data Analysis using data from the British Household Panel survey 1999–2002

\ua9 2024 The AuthorsA Minimum Income Guarantee (MIG) ensures people have a minimum amount of income for essentials such as healthy food, housing, health care, social and digital networks to support health and well-being. MIGs could be a useful tool to reduce inequalities. A MIG will only be effective if those who are eligible take it up. The aim of this paper is to explore how individual characteristics were associated with take-up of a MIG for pensioners (aged 60+ for women and aged 65+ for men) in England. The data used is from the British Household Panel Survey including 9430 observations from 1893 people, from 1999 to 2002. We estimated a random effects logistic regression. Results show that women were less likely to claim than men (OR ranging from 0.17 [95% CI 0.10–0.29]-0.73 [95% CI 0.40–1.34]), and couples were less likely to claim (OR ranging from 0.04 [95% CI 0.03–0.06]-0.01 [95%CI 0.01–0.02]) than single person households. People with better mental health (OR 1.05 95% CI 1.02–1.08), older pensioners (75+) (OR ranging from 1.98 [95% CI 1.52–2.59]-2.81 [95%CI 2.16–3.67]), those who were registered disabled (OR 4.03 95% CI 2.50–6.52), and those with no formal qualification (OR ranging from 1.74 [95%CI 0.93–3.26]-2.07 [95% CI 1.22–3.51]) were more likely to claim. Understanding who is likely to claim MIGs is important to avoid social security policy inadvertently increasing inequalities

Transgenic mouse lines for non-invasive ratiometric monitoring of intracellular chloride

Chloride is the most abundant physiological anion and participates in a variety of cellular processes including trans-epithelial transport, cell volume regulation, and regulation of electrical excitability. The development of tools to monitor intracellular chloride concentration ([Cli]) is therefore important for the evaluation of cellular function in normal and pathological conditions. Recently, several Cl-sensitive genetically encoded probes have been described which allow for non-invasive monitoring of [Cli]. Here we describe two mouse lines expressing a CFP-YFP-based Cl probe called Cl-Sensor. First, we generated transgenic mice expressing Cl-Sensor under the control of the mouse Thy1 mini promoter. Cl-Sensor exhibited good expression from postnatal day two (P2) in neurons of the hippocampus and cortex, and its level increased strongly during development. Using simultaneous whole-cell monitoring of ionic currents and Cl-dependent fluorescence, we determined that the apparent EC50 for Cli was 46 mM, indicating that this line is appropriate for measuring neuronal [Cli] in postnatal mice. We also describe a transgenic mouse reporter line for Cre-dependent conditional expression of Cl-Sensor, which was targeted to the Rosa26 locus and by incorporating a strong exogenous promoter induced robust expression upon Cre-mediated recombination. We demonstrate high levels of tissue-specific expression in two different Cre-driver lines targeting cells of the myeloid lineage and peripheral sensory neurons. Using these mice the apparent EC50 for Cli was estimated to be 61 and 54 mM in macrophages and DRG, respectively. Our data suggest that these mouse lines will be useful models for ratiometric monitoring of Cli in specific cell types in vivo. © 2013 Batti, Mukhtarov, Audero, Ivanov, Paolicelli, Zurborg, Gross, Bregestovski and Heppenstall

A ligand-based system for receptor-specific delivery of proteins

Gene delivery using vector or viral-based methods is often limited by technical and safety barriers. A promising alternative that circumvents these shortcomings is the direct delivery of proteins into cells. Here we introduce a non-viral, ligand-mediated protein delivery system capable of selectively targeting primary skin cells in-vivo. Using orthologous self-labelling tags and chemical cross-linkers, we conjugate large proteins to ligands that bind their natural receptors on the surface of keratinocytes. Targeted CRE-mediated recombination was achieved by delivery of ligand cross-linked CRE protein to the skin of transgenic reporter mice, but was absent in mice lacking the ligand\u2019s cell surface receptor. We further show that ligands mediate the intracellular delivery of Cas9 allowing for CRISPR-mediated gene editing in the skin more efficiently than adeno-associated viral gene delivery. Thus, a ligand-based system enables the effective and receptor-specific delivery of large proteins and may be applied to the treatment of skin-related genetic diseases

Stability of cellulose lyotropic liquid crystal emulsions

We studied a new kind of W/O emulsions based on a lyotropic liquid crystal as the aqueous droplet phase. The cholesteric phase, a solution hydroxypropyl cellulose in water was dispersed in the continuous oil matrix, paraffin oil or heptane. We made a specific choice of surfactant in order to impose director anchoring conditions at the oil-water interface and orient the liquid crystal inside the droplet. The strong anchoring conditions resulted in a topological defect inside the droplets of size above the critical value R*. The defect elastic energy creates a barrier against droplet coalescence, the effect of topological size selection. We have studied the orientation of the director inside the droplets and their size distribution

Transgenic mouse lines for non-invasive ratiometric monitoring of intracellular chloride

Chloride is the most abundant physiological anion and participates in a variety of cellular processes including trans-epithelial transport, cell volume regulation, and regulation of electrical excitability. The development of tools to monitor intracellular chloride concentration ([Cli]) is therefore important for the evaluation of cellular function in normal and pathological conditions. Recently, several Cl-sensitive genetically encoded probes have been described which allow for non-invasive monitoring of [Cli]. Here we describe two mouse lines expressing a CFP-YFP-based Cl probe called Cl-Sensor. First, we generated transgenic mice expressing Cl-Sensor under the control of the mouse Thy1 mini promoter. Cl-Sensor exhibited good expression from postnatal day two (P2) in neurons of the hippocampus and cortex, and its level increased strongly during development. Using simultaneous whole-cell monitoring of ionic currents and Cl-dependent fluorescence, we determined that the apparent EC50 for Cli was 46 mM, indicating that this line is appropriate for measuring neuronal [Cli] in postnatal mice. We also describe a transgenic mouse reporter line for Cre-dependent conditional expression of Cl-Sensor, which was targeted to the Rosa26 locus and by incorporating a strong exogenous promoter induced robust expression upon Cre-mediated recombination. We demonstrate high levels of tissue-specific expression in two different Cre-driver lines targeting cells of the myeloid lineage and peripheral sensory neurons. Using these mice the apparent EC50 for Cli was estimated to be 61 and 54 mM in macrophages and DRG, respectively. Our data suggest that these mouse lines will be useful models for ratiometric monitoring of Cli in specific cell types in vivo. © 2013 Batti, Mukhtarov, Audero, Ivanov, Paolicelli, Zurborg, Gross, Bregestovski and Heppenstall