408 research outputs found

    Water use in Florida: Examining Perceptions of Water use Based on Visual Images

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    Residents and decision makers often perceive information regarding water use differently. This is an issue in Florida where water quantity is a concern, and the distribution of accurate knowledge will be necessary to assist in effective conservation efforts. This study used two online surveys to gain insight into Florida residents’ and decision makers’ (county commissioners, county clerks and county managers) perceptions of water use based on visual images. Using non-probability opt-in sampling methods a total of 525 Florida residents’ responses were collected, and in a second survey 169 decision makers’ responses were collected. Respondents were asked to associate a specific water user, based on a visual, with high, moderate, or low water usage. A series of chi-square tests were used to compare and test for differences between Florida residents’ and decision makers’ perceptions, revealing that significant differences in perception did exist. The identification of these differences was used to develop recommendations for enhancing education and communication regarding water use

    Combining Computational Fluid Dynamics and Agent-Based Modeling: A New Approach to Evacuation Planning

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    We introduce a novel hybrid of two fields—Computational Fluid Dynamics (CFD) and Agent-Based Modeling (ABM)—as a powerful new technique for urban evacuation planning. CFD is a predominant technique for modeling airborne transport of contaminants, while ABM is a powerful approach for modeling social dynamics in populations of adaptive individuals. The hybrid CFD-ABM method is capable of simulating how large, spatially-distributed populations might respond to a physically realistic contaminant plume. We demonstrate the overall feasibility of CFD-ABM evacuation design, using the case of a hypothetical aerosol release in Los Angeles to explore potential effectiveness of various policy regimes. We conclude by arguing that this new approach can be powerfully applied to arbitrary population centers, offering an unprecedented preparedness and catastrophic event response tool

    Mutagen-induced diploid human lymphoblast variants containing altered hypoxanthine guanine phosphoribosyl transferase

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    The human lymphoblast line MGL8 was treated with HAT and subsequently “mutagenized” with EMS (200 μg/ml) to give 15% survival, and 6-thioguanine-resistant cells were selected by cloning in soft agarose containing the drug (1 μg/ml). Eighteen sublines of independently derived resistant clones were isolated and studied in detail. One subline had a low residual HGPRT activity of about 1% of the parental cells. The HGPRT of this subline had a higher K m for PRPP, was more sensitive to heat, and was degraded faster by trypsin than the enzyme in extracts of MGL8 cells. This resistant subline and three others contained CRM levels of 1-38%, compared to the wild-type, so they probably represent true structural mutants of the HGPRT gene. All the variants maintained the karyotype of the parental line (46, XY, 6p − ).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45551/1/11188_2005_Article_BF01551810.pd

    Analysis of HGPRT − CRM + human lymphoblast mutants

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    Three 6-thioguanine-resistant mutants of the human diploid lymphoblast line MGL-8 were studied. The inactivation by heat of both HGPRT activity and antigenicity of the HGPRT immunologically cross-reacting material of the A30 mutant cells were not protected by PRPP, indicating that the HGPRT in A30 cells has an altered PRPP binding site, leading to lack of stabilization and rapid degradation of the enzyme. Two dimensional separations of the immunoprecipitates from extracts of the parental and mutant cell lines showed that the A35 mutant CRM has a more acidic isoelectric pH, while the A30 CRM has a more basic isoelectric pH and that the A30 protein has a faster rate of degradation than the wild-type HGPRT. The A30 CRM also has a smaller molecular size than the wild-type enzyme .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45555/1/11188_2005_Article_BF01542643.pd

    Impact of sequencing depth in ChIP-seq experiments

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    In a chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) experiment, an important consideration in experimental design is the minimum number of sequenced reads required to obtain statistically significant results. We present an extensive evaluation of the impact of sequencing depth on identification of enriched regions for key histone modifications (H3K4me3, H3K36me3, H3K27me3 and H3K9me2/me3) using deep-sequenced datasets in human and fly. We propose to define sufficient sequencing depth as the number of reads at which detected enrichment regions increase <1% for an additional million reads. Although the required depth depends on the nature of the mark and the state of the cell in each experiment, we observe that sufficient depth is often reached at <20 million reads for fly. For human, there are no clear saturation points for the examined datasets, but our analysis suggests 40–50 million reads as a practical minimum for most marks. We also devise a mathematical model to estimate the sufficient depth and total genomic coverage of a mark. Lastly, we find that the five algorithms tested do not agree well for broad enrichment profiles, especially at lower depths. Our findings suggest that sufficient sequencing depth and an appropriate peak-calling algorithm are essential for ensuring robustness of conclusions derived from ChIP-seq data

    Unemployment expectations in an agent-based model with education

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    Why are unemployment expectations of the “man in the street” markedly different from professional forecasts? We present an agent-based model to explain this deep disconnection using boundedly rational agents with different levels of education. A good fit of empirical data is obtained under the assumptions that there is staggered update of information, agents update episodically their estimate and there is a fraction of households who always and stubbornly forecast that the unemployment is going to raise. The model also sheds light on the role of education and suggests that more educated agents update their information more often and less obstinately fixate on the worst possible forecast

    Comparisons of Aerosol Generation Across Different Musical Instruments and Loudness

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    Highlights•Aerosol number and mass concentrations measured during musical instrument playing.•A 1 dBA increase in sound pressure level yields ∼10% increase in number concentration.•Loudness of playing explains some but not all differences across instruments.•Musical instrument playing size distributions are consistent with those of breathing.•Simple songs sufficient to characterise aerosol emission during actual performance.AbstractRespiratory aerosols can serve as vectors for disease transmission, and aerosol emission is highly activity-dependent. COVID-19 severely impacted the performing arts due to concerns about disease spread by respiratory aerosols and droplets generated during singing and playing musical instruments. Aerosol generation from woodwind and brass performance is less understood compared to singing due to uncertainty about how the diverse range of musical instruments may impact respiratory aerosol concentrations and size distributions. Here, aerosol number and mass concentrations along with size distributions were measured for breathing, speaking, and playing four different woodwind and brass instruments by 23 professional instrumentalists. We find that a 1 dBA increase in sound pressure level corresponds to a ∼10% increase in aerosol number concentration. The aerosol size distribution is consistent with that of breathing. Differences in aerosol emission across musical instruments can be partly explained by the loudness of performance. Measuring aerosol generation from single notes or simple songs may be sufficient to characterise the aerosol emission range during actual performance, provided a range of loudnesses are accessed. These results provide insight into the factors contributing to aerosol emission during musical performance and facilitate risk assessments associated with infectious respiratory disease transmission in the performing arts

    Population growth and collapse in a multiagent model of the Kayenta Anasazi in Long House Valley

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    A s the only social science that has access to data of sufficient duration to reveal long-term changes in patterned human behavior, archaeology traditionally has been concerned with describing and explaining how societies adapt and evolve in response to changing conditions. A major impediment to rigorous investigation in archaeology-the inability to conduct reproducible experiments-is one shared with certain other sciences, such as astronomy, geophysics, and paleontology. Computational modeling is providing a way around these difficulties. k Within anthropology and archaeology there has been a rapidly growing interest in so-called agent-based computational model

    Population growth and collapse in a multiagent model of the Kayenta Anasazi in Long House Valley

    Get PDF
    A s the only social science that has access to data of sufficient duration to reveal long-term changes in patterned human behavior, archaeology traditionally has been concerned with describing and explaining how societies adapt and evolve in response to changing conditions. A major impediment to rigorous investigation in archaeology-the inability to conduct reproducible experiments-is one shared with certain other sciences, such as astronomy, geophysics, and paleontology. Computational modeling is providing a way around these difficulties. k Within anthropology and archaeology there has been a rapidly growing interest in so-called agent-based computational model
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