306 research outputs found
EVALUATING THE ROLE OF LATINIDAD AND THE LATINO THREAT IN THE STATE OF MISSOURI
Growing Latino populations in midwestern cities of the United States are leading to the creation of contested ethnic spaces and urban landscapes. In this article we examine the historical, demographic, and social contexts associated with a growing sense of Latinidad and the countervailing Latino threat narrative in Kansas City and St. Louis, the two largest metropolitan areas in Missouri. Latinidad, or a notion of belonging based on ethnic identity in Missouri, is being challenged by nativist discourses that frame the growing Latino population as a threat. We highlight the different historical trajectories and geographical characteristics that have created distinct demographic profiles among the emerging Latino populations of Kansas City and St. Louis. These demographic profiles reflect the historical and geographic specificities of each city, but also highlight the ways that the Latino populations in two geographically proximate urban areas in the Midwest can have different trajectories. Finally, we outline three instances of Latino struggles for social and/or political recognition in Missouri, and suggest that the meaning of Latino population growth for both cities will be contested through the conflicting discourses of Latinidad and Latino threat
Tumour heterogeneity promotes collective invasion and cancer metastatic dissemination.
Heterogeneity within tumour cell populations is commonly observed in most cancers. However, its impact on metastatic dissemination, one of the primary determinants of the disease prognosis, remains poorly understood. Working with a simplified numerical model of tumour spheroids, we investigated the impact of mechanical heterogeneity on the onset of tumour invasion into surrounding tissues. Our work establishes a positive link between tumour heterogeneity and metastatic dissemination, and recapitulates a number of invasion patterns identified in vivo, such as multicellular finger-like protrusions. Two complementary mechanisms are at play in heterogeneous tumours. A small proportion of stronger cells are able to initiate and lead the escape of cells, while collective effects in the bulk of the tumour provide the coordination required to sustain the invasive process through multicellular streaming. This suggests that the multicellular dynamics observed during metastasis is a generic feature of mechanically heterogeneous cell populations and might rely on a limited and generic set of attributes
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A new computational model for multi-cellular biological systems
The early development of an animal results from a highly complex
sequence of interactions within and between cells to transform a fertilised egg into a functional embryo. A major challenge in the field
of morphogenesis is explaining how coordinated cell shape change,
growth and movement create the structures that we are familiar with,
and what drives the processes that pattern and control this behaviour.
Embryos are complicated mechanical systems for which we have a
wealth of morphological data about the shapes and movements of
cells but it is diffcult to understand how these movements emerge as
a result of force-generating mechanisms within the embryo.
A new, force-based modelling technique designed to test hypotheses
about dynamic processes within an embryo is presented. The model
focusses on how the mechanical properties of a cell and inter-cellular
forces affect the movements we see within a tissue. It is designed to
probe the relationships between cellular and tissue behaviours; such
as how forces propagate through a system or the response of a tissue
to applied forces.
The novel features of the model are discussed along with analysis of
tissue and cellular behaviours for different idealised systems, describing how the parameters of the model affect experimental observables.
The model is applied to two real world systems. Firstly examining the
role of boundary conditions on the patterning seen in the formation
of the zebrafish forebrain neural plate. Secondly, two proposed hypotheses for the formation of the primitive streak in the chick embryo
are investigated and compared. These applications demonstrate how
the model can be used to complement experimental studies and help
to tease out the mechanical processes driving morphogenesis.EPSRC/BBSR
Efficient Real-world Testing of Causal Decision Making via Bayesian Experimental Design for Contextual Optimisation
The real-world testing of decisions made using causal machine learning models
is an essential prerequisite for their successful application. We focus on
evaluating and improving contextual treatment assignment decisions: these are
personalised treatments applied to e.g. customers, each with their own
contextual information, with the aim of maximising a reward. In this paper we
introduce a model-agnostic framework for gathering data to evaluate and improve
contextual decision making through Bayesian Experimental Design. Specifically,
our method is used for the data-efficient evaluation of the regret of past
treatment assignments. Unlike approaches such as A/B testing, our method avoids
assigning treatments that are known to be highly sub-optimal, whilst engaging
in some exploration to gather pertinent information. We achieve this by
introducing an information-based design objective, which we optimise
end-to-end. Our method applies to discrete and continuous treatments. Comparing
our information-theoretic approach to baselines in several simulation studies
demonstrates the superior performance of our proposed approach.Comment: ICML 2022 Workshop on Adaptive Experimental Design and Active
Learning in the Real World. 16 pages, 5 figure
Doubly Illegal: Qualitative Accounts of Underage Alcohol Access Through Theft
This study investigated sources of alcohol for underage drinkers. In-depth, semi-structured interviews were individually conducted with 47 youths, ages 15-18, who reported drinking within the last 12 months, to explore alcohol access. Theft was one method that some youths reported using to obtain alcohol. In addition to 9% of respondents who reported stealing alcohol from commercial outlets themselves, a total of 26% respondents reported occasions when their close friends stole alcohol. Our findings unveiled that teens had a body of knowledge that some drew upon for stealing alcohol. Youths revealed detailed knowledge about store layout, theft protection devices and store policies. In particular, respondents disclosed knowledge about which aisles have blind spots, how to remove security tops on bottles, and nochase policies. Theft of alcohol from commercial sources may be reduced by examining the weaknesses of existing theft prevention practices, and revising store policies
Cancer Metastasis: Collective Invasion in Heterogeneous Multicellular Systems
These are supplementary files for the paper:
Cancer Metastasis: Collective Invasion in Heterogeneous Multicellular System
Test Plan for a Calibration Demonstration System for the Reflected Solar Instrument for the Climate Absolute Radiance and Refractivity Observatory
The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission addresses the need to observe high-accuracy, long-term climate change trends and to use decadal change observations as the most critical method to determine the accuracy of climate change. One of the major objectives of CLARREO is to advance the accuracy of SI traceable absolute calibration at infrared and reflected solar wavelengths. This advance is required to reach the on-orbit absolute accuracy required to allow climate change observations to survive data gaps while remaining sufficiently accurate to observe climate change to within the uncertainty of the limit of natural variability. While these capabilities exist at NIST in the laboratory, there is a need to demonstrate that it can move successfully from NIST to NASA and/or instrument vendor capabilities for future spaceborne instruments. The current work describes the test plan for the Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) which is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO. The goal of the CDS is to allow the testing and evaluation of calibration approaches , alternate design and/or implementation approaches and components for the CLARREO mission. SOLARIS also provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. The end result of efforts with the SOLARIS CDS will be an SI-traceable error budget for reflectance retrieval using solar irradiance as a reference and methods for laboratory-based, absolute calibration suitable for climate-quality data collections. The CLARREO mission addresses the need to observe high-accuracy, long-term climate change trends and advance the accuracy of SI traceable absolute calibration. The current work describes the test plan for the SOLARIS which is the calibration demonstration system for the reflected solar portion of CLARREO. SOLARIS provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. The end result will be an SI-traceable error budget for reflectance retrieval using solar irradiance as a reference and methods for laboratory-based, absolute calibration suitable for climate-quality data collections
Tariff agent: interacting with a future smart energy system at home
Smart systems are becoming increasingly ubiquitous and consequently transforming our lives. The level of system autonomy plays a vital role in the development of smart systems as it profoundly affects how people and these systems interact with each other. However, to date, there are very few studies on human interaction with such systems. This paper presents findings from two field studies where two different prototypes for automating energy tariff-switching were developed and evaluated in the wild. Both prototypes offer flexible autonomy by which users can shift the system's level of autonomy among three options: suggestion-only, semi-autonomy, and full autonomy, whenever they like. Our findings based on thematic analysis show that flexible autonomy is a promising way to sustain users' engagement with smart systems, despite their occasional mistakes. The findings also suggest that users take responsibility for the undesired outcomes of automated actions when delegation of autonomy can be adjusted flexibly
Social implications of agent-based planning support for human teams
We present a field trial of how instructions from an intelligent planning agent are dealt with by distributed human teams, in a time-critical task setting created through a mixed-reality game. We conduct interaction analysis to examine video recorded field observations and game log data. The findings highlight the social process by which players interpret and negotiate the agent guidance as well as how these are intertwined with social dynamics of the teams. The insights can be used to develop an understanding of interactional issues around automated team instructions and inform the design of human-centred planning support systems
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