Freedom, Servitude and Voluntary Labor

We present an economic framework to revisit and reframe some important debates over the nature of free versus unfree labor and the economic consequences of emancipation. We use a simple general equilibrium model in which labor can be either free or coerced and where land and labor will be exchanged on markets that can be competitive or manipulated or via other non-market collusive arrangements. By working with variants of the same basic model under different assumptions about initial economy-wide factor endowments and asset ownership we can compare equilibrium distributional outcomes under different institutional and contractual arrangements including markets with free labor and free tenancy, slavery, and tenancy arrangements with tied labor-service obligations. Analysis of these different contractual and organizational forms yields insights that accord with common sense, but that are often overlooked or downplayed in academic debates, particularly amongst economists

A Genetically Encoded Tag for Correlated Light and Electron Microscopy of Intact Cells, Tissues, and Organisms

Electron microscopy (EM) achieves the highest spatial resolution in protein localization, but specific protein EM labeling has lacked generally applicable genetically encoded tags for in situ visualization in cells and tissues. Here we introduce “miniSOG” (for mini Singlet Oxygen Generator), a fluorescent flavoprotein engineered from Arabidopsis phototropin 2. MiniSOG contains 106 amino acids, less than half the size of Green Fluorescent Protein. Illumination of miniSOG generates sufficient singlet oxygen to locally catalyze the polymerization of diaminobenzidine into an osmiophilic reaction product resolvable by EM. MiniSOG fusions to many well-characterized proteins localize correctly in mammalian cells, intact nematodes, and rodents, enabling correlated fluorescence and EM from large volumes of tissue after strong aldehyde fixation, without the need for exogenous ligands, probes, or destructive permeabilizing detergents. MiniSOG permits high quality ultrastructural preservation and 3-dimensional protein localization via electron tomography or serial section block face scanning electron microscopy. EM shows that miniSOG-tagged SynCAM1 is presynaptic in cultured cortical neurons, whereas miniSOG-tagged SynCAM2 is postsynaptic in culture and in intact mice. Thus SynCAM1 and SynCAM2 could be heterophilic partners. MiniSOG may do for EM what Green Fluorescent Protein did for fluorescence microscopy

Features of urban green spaces associated with positive emotions, mindfulness and relaxation

Abstract There is an established consensus among researchers that contact with nature improves mental health, wellbeing, and quality of life in urbanised environments. Studies tend to examine the health impacts of nature without identifying specific physical and spatial landscape features that could guide health-promoting design of urban green spaces. A growing body of evidence suggests that landscape features described in the Contemplative Landscape Model (CLM) can be used to measure therapeutic value of urban landscapes. CLM assesses urban landscapes across seven sub-scales: Layers of the Landscape, Landform, Vegetation, Color and Light, Compatibility, Archetypal Elements and Character of Peace and Silence. We exposed 74 healthy adults to six urban landscapes in laboratory (video representations) and naturalistic outdoor settings. We explored the associations between the visual quality of urban landscapes annotated with CLM, with self-reported positive emotions and brain activity consistent with mindfulness (Theta waves), relaxation (Alpha waves) and attention restoration (Beta waves), and differences between laboratory and naturalistic setting. CLM scores predicted self-reported Valence and Arousal, and low frequency power bands: Alpha and Theta in the naturalistic setting. Landscape features showing the strongest associations were Character of Peace and Silence, Layers of the Landscape and Archetypal Elements. Alpha, Theta brain reactivity and Arousal scores, were significantly different between laboratory and naturalistic settings (p < 0.05), while Valence scores between those settings were statistically identical (p = 0.22). Self-reported Valence and Arousal, but not brain activity, were significantly associated with the majority of landscape features in the laboratory setting. The results of the study provide guidelines on the urban landscape features most beneficial for human health, to inform urban green space design

Preservation of Reduced Carbon on Mars: Implications for Understanding Habitability

Upcoming Mars missions (e.g., Mars Science Laboratory, ExoMars, Astrobiology Field Laboratory, and Mars Sample Return) will search for evidence of extant and fossil microbial habitats and the potential for future habitation. Understanding the distribution and composition of reduced carbon (or organic carbon) is critical for unraveling the Martian carbon cycle, potential for life, and possible biosignature record. Reduced carbon may be produced from biological, geochemical, or interstellar processes; however, evidence for reduced carbon on Mars is lacking with the exception of parts per billion of atmospheric methane. In contrast, abundant atmospheric carbon dioxide may reflect surface oxidation of reduced carbon and accumulation over geological timescales. This suggests that there is an undetected or lost pool of reduced carbon - a pool that may host molecular biosignatures, a characteristic of extant or extinct habitability. In this presentation, we will evaluate factors influencing the preservation potential for organic molecules in rocks on Earth and Martian. We,draw examples from organic molecules in sulfates, basalts, and ancient shales from Mars-analog settings to show how the distribution of organics and their structural patterns will aid Mars habitability studies

Nature-based activities improve the well-being of older adults (vol 10, 18178, 2020)

10.1038/s41598-021-96296-6SCIENTIFIC REPORTS11