Analyzes Mississippian daily life at Cahokia’s environs during wartime
In Life in a Mississippian Warscape: Common Field, Cahokia, and the Effects of Warfare Meghan E. Buchanan posits that to ...understand the big histories of warfare, political fragmentation, and resilience in the past archaeologists must also analyze and interpret the microscale actions of the past. These are the daily activities of people before, during, and after historical events. Within warscapes, battles take place in peoples’ front yards, family members die, and the impacts of violence in near and distant places are experienced on a daily basis. This book explores the microscale of daily lives of people living at Common Field, a large, palisaded mound center, during the period of Cahokia’s abandonment and the spread of violence and warfare throughout the Southeast.
Linking together ethnographic, historic, and archaeological sources, Buchanan discusses the evidence that the people of Common Field engaged in novel and hybrid practices in these dangerous times. At the microscale, they adopted new ceramic tempering techniques, produced large numbers of serving vessels decorated with warfare-related imagery, adapted their food practices, and erected a substantial palisade with specially prepared deposits. The overall picture that emerges at Common Field is of a people who engaged in risk-averse practices that minimized their exposure to outside of the palisade and attempted to seek intercession from otherworldly realms through public ceremonies involving warfare-related iconography.
Three longitudinal studies examine a fundamental question regarding adjustment of personal values to self-chosen life transitions: Do values fit the new life setting already at its onset, implying ...value-based self-selection? Or do values change to better fit the appropriate and desirable values in the setting, implying value socialization? As people are likely to choose a life transition partly based on their values, their values may fit the new life situation already at its onset, leaving little need for value socialization. However, we propose that this may vary as a function of the extent of change the life transition entails, with greater change requiring more value socialization. To enable generalization, we used 3 longitudinal studies spanning 3 different life transitions and different extents of life changes: vocational training (of new police recruits), education (psychology vs. business students), and migration (from Poland to Britain). Although each life transition involved different key values and different populations, across all 3 studies we found value fit to the life situation already early in the transition. Value socialization became more evident the more aspects of life changed as part of the transition, that is, in the migration transition. The discussion focuses on the implications of these findings for research on values and personality change, as well as limitations and future directions for research.
Urea/water is an archetypical “biological” mixture and is especially well-known for its relevance to protein thermodynamics as urea acts as a protein denaturant at high concentration. This behavior ...has given rise to an extended debate concerning urea’s influence on water structure. On the basis of a variety of methods and of definitions of the water structure, urea has been variously described as a structure-breaker, a structure-maker, or as remarkably neutral toward water. Because of its sensitivity to microscopic structure and dynamics, vibrational spectroscopy can help resolve these debates. We report experimental and theoretical spectroscopic results for the OD stretch of HOD/H2O/urea mixtures (linear IR, 2DIR, and pump–probe anisotropy decay) and for the CO stretch of urea-D4/D2O mixtures (linear IR only). Theoretical results are obtained using existing approaches for water and a modification of a frequency map developed for acetamide. All absorption spectra are remarkably insensitive to urea concentration, consistent with the idea that urea only very weakly perturbs the water structure. Both this work and experiments by Rezus and Bakker, however, show that water’s rotational dynamics are slowed down by urea. Analysis of the simulations casts doubt on the suggestion that urea immobilizes particular doubly hydrogen bonded water molecules.
A technology that simultaneously records membrane potential from multiple neurons in behaving animals will have a transformative effect on neuroscience research
. Genetically encoded voltage ...indicators are a promising tool for these purposes; however, these have so far been limited to single-cell recordings with a marginal signal-to-noise ratio in vivo
. Here we developed improved near-infrared voltage indicators, high-speed microscopes and targeted gene expression schemes that enabled simultaneous in vivo recordings of supra- and subthreshold voltage dynamics in multiple neurons in the hippocampus of behaving mice. The reporters revealed subcellular details of back-propagating action potentials and correlations in subthreshold voltage between multiple cells. In combination with stimulation using optogenetics, the reporters revealed changes in neuronal excitability that were dependent on the behavioural state, reflecting the interplay of excitatory and inhibitory synaptic inputs. These tools open the possibility for detailed explorations of network dynamics in the context of behaviour. Fig. 1 PHOTOACTIVATED QUASAR3 (PAQUASAR3) REPORTS NEURONAL ACTIVITY IN VIVO.: a, Schematic of the paQuasAr3 construct. b, Photoactivation by blue light enhanced voltage signals excited by red light in cultured neurons that expressed paQuasAr3 (representative example of n = 4 cells). c, Model of the photocycle of paQuasAr3. d, Confocal images of sparsely expressed paQuasAr3 in brain slices. Scale bars, 50 μm. Representative images, experiments were repeated in n = 3 mice. e, Simultaneous fluorescence and patch-clamp recordings from a neuron expressing paQuasAr3 in acute brain slice. Top, magnification of boxed regions. Schematic shows brain slice, patch pipette and microscope objective. f, Simultaneous fluorescence and patch-clamp recordings of inhibitory post synaptic potentials in an L2-3 neuron induced by electrical stimulation of L5-6 in acute slice. g, Normalized change in fluorescence (ΔF/F) and SNR of optically recorded post-synaptic potentials (PSPs) as a function of the amplitude of the post-synaptic potentials. The voltage sensitivity was ΔF/F = 40 ± 1.7% per 100 mV. The SNR was 0.93 ± 0.07 per 1 mV in a 1-kHz bandwidth (n = 42 post-synaptic potentials from 5 cells, data are mean ± s.d.). Schematic shows brain slice, patch pipette, field stimulation electrodes and microscope objective. h, Optical measurements of paQuasAr3 fluorescence in the CA1 region of the hippocampus (top) and glomerular layer of the olfactory bulb (bottom) of anaesthetized mice (representative traces from n = 7 CA1 cells and n = 13 olfactory bulb cells, n = 3 mice). Schematics show microscope objective and the imaged brain region. i, STA fluorescence from 88 spikes in a CA1 oriens neuron. j, Frames from the STA video showing the delay in the back-propagating action potential in the dendrites relative to the soma. k, Sub-Nyquist fitting of the action potential delay and width shows electrical compartmentalization in the dendrites. Experiments in k-m were repeated in n = 2 cells from n = 2 mice.
Who should decide how limited resources are prioritized? We ask this question in a healthcare context where patients must be prioritized according to their need and where advances in autonomous ...artificial intelligence-based technology offer a compelling alternative to decisions by humans. Qualitative (Study 1a; N = 50) and quantitative (Study 1b; N = 800) analysis identified agency, emotional experience, bias-free, and error-free as four main qualities describing people's perceptions of autonomous computer programs (ACPs) and human staff members (HSMs). Yet, the qualities were not perceived to be possessed equally by HSMs and ACPs. HSMs were endorsed with human qualities of agency and emotional experience, whereas ACPs were perceived as more capable than HSMs of bias- and error-free decision-making. Consequently, better than average (Study 2; N = 371), or relatively better (Studies 3, N = 181; & 4, N = 378), ACP performance, especially on qualities characteristic of ACPs, was sufficient to reverse preferences to favor ACPs over HSMs as the decision makers for how limited healthcare resources should be prioritized. Our findings serve a practical purpose regarding potential barriers to public acceptance of technology, and have theoretical value for our understanding of perceptions of autonomous technologies.
Amyloid formation is implicated in more than 20 human diseases, yet the mechanism by which fibrils form is not well understood. We use 2D infrared spectroscopy and isotope labeling to monitor the ...kinetics of fibril formation by human islet amyloid polypeptide (hIAPP or amylin) that is associated with type 2 diabetes. We find that an oligomeric intermediate forms during the lag phase with parallel β-sheet structure in a region that is ultimately a partially disordered loop in the fibril. We confirm the presence of this intermediate, using a set of homologous macrocyclic peptides designed to recognize β-sheets. Mutations and molecular dynamics simulations indicate that the intermediate is on pathway. Disrupting the oligomeric β-sheet to form the partially disordered loop of the fibrils creates a free energy barrier that is the origin of the lag phase during aggregation. These results help rationalize a wide range of previous fragment and mutation studies including mutations in other species that prevent the formation of amyloid plaques.
Recent neuroscience studies demonstrate that a deeper understanding of brain function requires a deeper understanding of behavior. Detailed behavioral measurements are now often collected using video ...cameras, resulting in an increased need for computer vision algorithms that extract useful information from video data. Here we introduce a new video analysis tool that combines the output of supervised pose estimation algorithms (e.g. DeepLabCut) with unsupervised dimensionality reduction methods to produce interpretable, low-dimensional representations of behavioral videos that extract more information than pose estimates alone. We demonstrate this tool by extracting interpretable behavioral features from videos of three different head-fixed mouse preparations, as well as a freely moving mouse in an open field arena, and show how these interpretable features can facilitate downstream behavioral and neural analyses. We also show how the behavioral features produced by our model improve the precision and interpretation of these downstream analyses compared to using the outputs of either fully supervised or fully unsupervised methods alone.
The present experiment was designed to establish the effects of acts of kindness and acts of novelty on life satisfaction. Participants aged 18-60 took part on a voluntary basis. They were randomly ...assigned to perform either acts of kindness, acts of novelty, or no acts on a daily basis for 10 days. Their life satisfaction was measured before and after the 10-day experiment. As expected, performing acts of kindness or acts of novelty resulted in an increase in life satisfaction.
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