Automated Cytogenetic Biodosimetry at Population-Scale

The dicentric chromosome (DC) assay accurately quantifies exposure to radiation; however, manual and semi-automated assignment of DCs has limited its use for a potential large-scale radiation incident. The Automated Dicentric Chromosome Identifier and Dose Estimator (ADCI) software automates unattended DC detection and determines radiation exposures, fulfilling IAEA criteria for triage biodosimetry. This study evaluates the throughput of high-performance ADCI (ADCI-HT) to stratify exposures of populations in 15 simulated population scale radiation exposures. ADCI-HT streamlines dose estimation using a supercomputer by optimal hierarchical scheduling of DC detection for varying numbers of samples and metaphase cell images in parallel on multiple processors. We evaluated processing times and accuracy of estimated exposures across census-defined populations. Image processing of 1744 samples on 16,384 CPUs required 1 h 11 min 23 s and radiation dose estimation based on DC frequencies required 32 sec. Processing of 40,000 samples at 10 exposures from five laboratories required 25 h and met IAEA criteria (dose estimates were within 0.5 Gy; median = 0.07). Geostatistically interpolated radiation exposure contours of simulated nuclear incidents were defined by samples exposed to clinically relevant exposure levels (1 and 2 Gy). Analysis of all exposed individuals with ADCI-HT required 0.6–7.4 days, depending on the population density of the simulation.

Modeling Habitat Suitability and Management Options for Maintaining Round Whitefish (Prosopium cylindraceum) in Adirondack Ponds

Habitat loss, acid precipitation, and nonnative species have drastically reduced the number of Adirondack waterbodies occupied by round whitefish (Prosopium cylindraceum). The goal of this study was to 1) increase the probability of reintroduction success by modeling the suitability of ponds for reintroduction and 2) better understand the effects of different rates of pond reclamation. We created a species distribution model that identified 70 waterbodies that were physically similar to occupied ponds. The most influential variables for describing round whitefish habitat included trophic, temperature, and alkalinity classes; waterbody maximum depth; maximum air temperature; and surrounding soil texture and impervious surface. Next, we simulated population dynamics under a variety of treatment scenarios and compared the probability of complete extirpation using a modified Markov model. Under almost all management strategies, and under pressure from nonnative competitors like that observed in the past 30 years, the number of occupied ponds will decline over the next 100 years. However, restoring one pond every 3 years would result in a 99% chance of round whitefish persistence after 100 years.

Ground-based visible spectroscopy of asteroids to support the development of an unsupervised Gaia asteroid taxonomy

Context. The Gaia mission of the European Space Agency is measuring reflectance spectra of a number to the order of 105 small Solar System objects. A first sample will be published in the Gaia Data Release scheduled for 2021. Aims. The aim of our work was to test the procedure developed to obtain taxonomic classifications for asteroids based only on Gaia spectroscopic data. Methods. We used asteroid spectra obtained using the DOLORES (Device Optimised for the LOw RESolution) instrument, a low-resolution spectrograph and camera installed at the Nasmyth B focus of the Telescopio Nazionale Galileo. Because these spectra have a higher spectral resolution than that typical of the Gaia spectra, we resampled them to more closely match the expected Gaia spectral resolution. We then developed a cloning algorithm to build a database of asteroid spectra belonging to a variety of taxonomic classes, starting from a set of 33 prototypes chosen from the 50 asteroids in our observing campaign. We used them to generate a simulated population of 10 000 representative asteroid spectra and employed them as the input to the algorithm for taxonomic classification developed to analyze Gaia asteroid spectra. Results. Using the simulated population of 10 000 representative asteroid spectra in the algorithm to be used to produce the Gaia asteroid taxonomy at the end of the mission, we found 12 distinct taxonomic classes. Two of them, with 53% of the sample, are dominant. At the other extreme are three classes each with <1% of the sample, and these consist of the previously known rare classes A, D/Ld, and V; 99.1% of the simulated population fall into a single class. Conclusions. We demonstrated the robustness of our algorithm for taxonomic classification by using a sample of simulated asteroid spectra fully representative of what is expected to be in the Gaia spectroscopic data catalogue for asteroids. Increasingly larger data sets will become available as soon as they are published in the future Gaia data releases, with the next one coming in 2021. This will be exploited to develop a correspondingly improved taxonomy, likely with minor tweaks to the algorithm described here, as suggested by the results of this preliminary analysis.

Projecting population distribution under depopulation conditions in Japan: scenario analysis for future socio-ecological systems

This study develops a projection model of future population distribution on the basis of Japan’s current depopulation trend and applies this model to scenario analyses that assume population compactification and dispersion. The model enables a description of population migration at two levels. First, municipal populations are projected using the cohort-component method, and second, the spatial distribution of populations within municipalities is projected at a 500 m grid resolution with the use of the gravity model. Based on the Japanese depopulation context and the country’s National Spatial Strategy, the compact scenario predicts the formation of medium-scale regional urban areas (population centers located across Japan) and the concentration of people on high-density population areas within municipalities. Meanwhile, the dispersed scenario predicts the formation of more but smaller regional urban areas and the dispersion of the population to low-density areas. The simulated population distribution for 2050 reveals spatial change in population density and age structure, as well as an abundance of areas that were inhabited in 2015 but will be zero population areas by 2050. Overlay analysis of future land use maps and the simulated population distribution maps can contribute toward identifying areas where natural capital such as farmland and forest plantation should be managed but where there will be significant population loss by 2050.

Mate selection provides similar genetic progress and average inbreeding than optimum contribution selection in the long-term

Optimum contribution selection (OCS) and mate selection (MS) are alternative strategies to maximize genetic gain under controlled rates of inbreeding. There is evidence in the literature that MS outperforms OCS in controlling inbreeding under the same expected genetic gain in the short-term. It is unclear, however, if the same would occur in the long-term. This study aimed to compare OCS and MS regarding short and long-term genetic progress and inbreeding, using simulated data. The structure of the simulated population aimed to mimic an aquaculture breeding program. Twenty discrete generations were simulated, considering 50 families and 2,000 offspring per generation, and a trait with a heritability of 0.3. OCS and MS were applied using a differential evolution (DE) algorithm, under an objective function that accounted for genetic merit, inbreeding of the future progeny and coancestry among selection candidates. For OCS, the optimization process consisted of selection based on optimum contribution followed by minimum inbreeding mating. Objective functions using different weights on coancestry were tested. For each application, 20 replicates were simulated and the results were compared based on their average. Both strategies, OCS and MS, were very effective in controlling inbreeding over the generations. In the short-term, MS was more efficient than OCS in controlling inbreeding under the same genetic gain. In the long-term, OCS and MS resulted in similar genetic progress and average inbreeding, under the same penalty on coancestry.

BDI vs FSM Agents in Social Simulations for Raising Awareness in Disasters

Each summer in Australia, bushfires burn many hectares of forest, causing deaths, injuries, and destroying property. Agent-based simulation is a powerful tool to test various management strategies on a simulated population, and to raise awareness of the actual population behaviour. But valid results depend on realistic underlying models. This article describes two simulations of the Australian population's behaviour during bushfires designed in previous work, one based on a finite-state machine architecture, the other based on a belief-desire-intention agent architecture. It then proposes several contributions towards more realistic agent-based models of human behaviour: a methodology and tool for easily designing BDI models; a number of objective and subjective criteria for comparing agent-based models; a comparison of our two models along these criteria, showing that BDI provides better explanability and understandability of behaviour, makes models easier to extend, and is therefore best adapted; and a discussion of possible extensions of BDI models to further improve their realism.

User Extreme Conditions to Enhance Designer Empathy and Creativity: Applications Using Visual Impairment

Designers often design for people unlike themselves. Many design tools and methods have been developed to support the designers in this task. One area is empathic design, where, simulated scenarios allow the designers to experience a situation that is less likely to be accessed otherwise. These simulated scenarios are widely used and past studies have shown these methods enhance designer creativity or evoke designer empathy. In this paper we investigate to what extent these simulated scenarios help increase designer empathy and creativity and how it compares to only being briefed about the target population. In this study 36 subjects took part in a workshop that included a briefing about the life of people with visual impairments as well as a simulation of such scenarios. Participants’ levels of creativity and empathy were assessed at three different stages during the workshop: (i) Pre-workshop, (ii) Post-briefing and (iii) Post-simulation. The results show that, the participants’ creativity in terms of novelty, quantity and breadth of the ideas was significantly high after the simulation when compared to only being briefed about the situation. There were no differences in the idea feasibility. All ideas were technically feasible. Also participant empathy increased significantly from before the workshop to post-simulation. A further comparison of the workshop reflections from both participants and volunteers with visual impairments were used to understand the extent to which the participants were able to empathize with people with visual impairments. We find the simulated scenario improved the participants’ ability to understand the simulated population compared to the before workshop state, but nevertheless, the participants were unable to match the level of detail given by the people with actual visual impairments.