39 research outputs found

    A Review on Energy, Environmental, and Sustainability Implications of Connected and Automated Vehicles

    Full text link
    Connected and automated vehicles (CAVs) are poised to reshape transportation and mobility by replacing humans as the driver and service provider. While the primary stated motivation for vehicle automation is to improve safety and convenience of road mobility, this transformation also provides a valuable opportunity to improve vehicle energy efficiency and reduce emissions in the transportation sector. Progress in vehicle efficiency and functionality, however, does not necessarily translate to net positive environmental outcomes. Here, we examine the interactions between CAV technology and the environment at four levels of increasing complexity: vehicle, transportation system, urban system, and society. We find that environmental impacts come from CAV-facilitated transformations at all four levels, rather than from CAV technology directly. We anticipate net positive environmental impacts at the vehicle, transportation system, and urban system levels, but expect greater vehicle utilization and shifts in travel patterns at the society level to offset some of these benefits. Focusing on the vehicle-level improvements associated with CAV technology is likely to yield excessively optimistic estimates of environmental benefits. Future research and policy efforts should strive to clarify the extent and possible synergetic effects from a systems level to envisage and address concerns regarding the short- and long-term sustainable adoption of CAV technology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149443/1/EEICAV_Taiebat et al (2018)_Environmental Science & Technology.pdfDescription of EEICAV_Taiebat et al (2018)_Environmental Science & Technology.pdf : Main articl

    Mauritius since the last glacial:environmental and climatic reconstruction of the last 38 000 years from Kanaka Crater

    Get PDF
    A 10 m long peat core from the Kanaka Crater (20° 25′ S, 57° 31′ E), located at 560 m elevation in Mauritius, was analyzed for microfossils. Eight radiocarbon ages show the pollen record reflects environmental and climatic change of the last ca. 38 cal ka BP. The record shows that the island was continuously covered by forest with Erica heath (Philippia) in the uplands. Cyperaceous reedswamp with Pandanus trees was abundant in the coastal lowlands as well as locally in the waterlogged crater. The record shows changes in climatic humidity (wet from 38.0 to 22.7 cal ka BP, drier from 22.7 to 10.6 cal ka BP, and wetter again from 10.6 cal ka BP to recent) as the main response to climate change. A high turnover in montane forest species is evidenced at 22.7 cal ka BP and at the start of the Holocene. The limited altitudinal ranges in the mountains of Mauritius (maximum altitude 828 m), and changing humidity being more important than changing temperature, suggests that in response to climate change a reassortment in taxonomic composition of montane forests might be equally important as displacement of forest types to new altitudinal intervals. We found weak impact of the latitudinal migration of the Intertropical Convergence Zone and data suggest that the Indian Ocean Dipole is a more important driver for climatic change in the southwest Indian Ocean

    How many bird and mammal extinctions has recent conservation action prevented?

    Get PDF
    Aichi Target 12 of the Convention on Biological Diversity (CBD) aims to ‘prevent extinctions of known threatened species’. To measure its success, we used a Delphi expert elicitation method to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993 - 2020 (the lifetime of the CBD) and 2010 - 2020 (the timing of Aichi Target 12). We found that conservation prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and 2–7 mammal extinctions since 2010. Many remain highly threatened, and may still become extinct in the near future. Nonetheless, given that ten bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions

    How many bird and mammal extinctions has recent conservation action prevented?

    Get PDF
    Aichi Target 12 of the Convention on Biological Diversity (CBD) contains the aim to ‘prevent extinctions of known threatened species’. To measure the degree to which this was achieved, we used expert elicitation to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993–2020 (the lifetime of the CBD) and 2010–2020 (the timing of Aichi Target 12). We found that conservation action prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and two to seven mammal extinctions since 2010. Many remain highly threatened and may still become extinct. Considering that 10 bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions.https://wileyonlinelibrary.com/journal/conlMammal Research Institut

    Individual-Based Modeling of Collective Dynamics

    No full text
    Collective dynamics play an important role in facilitating group movement, decision-making, and other large-scale behaviors in a wide variety of biological systems. In recent years, technological advances have made it possible to probe deeper into the microscopic factors underlying these macroscopic phenomena using computer-assisted mathematical modeling and data analysis. In this thesis, I describe and validate a mathematical individual-based model of collective motion developed by Couzin et al. (2005). I demonstrate how diffusion mapping, a relatively new data-mining technique, can be used to systematically analyze simulation data generated by the Couzin model to identify microscopic influences that can cause a coherent group to break apart. I find that group breakups occur when the orientation of the group deviates from its coherent direction by approximately 90°, and that changes in the orientation of only a few members of the group may play a disproportionate role in initiating an irreversible change in the orientation of the group as a whole. I suggest that an understanding of the breakup mechanism could be used to inform improved methods of controlling harmful locust swarms, illustrating this potential application with two case studies: the 1986-1989 outbreak of desert locusts (Schistocerca gregaria) in the Sahel region of northern Africa, and the 2010-2011 outbreak of Australian plague locusts (Chortoicetes terminifera) in southeastern Australia

    Flow virometry for water-quality assessment: Protocol optimization for a model virus and automation of data analysis

    No full text
    Flow virometry (FVM) can support advanced water treatment and reuse by delivering near real-time information about viral water quality. But maximizing the potential of FVM in water treatment and reuse applications requires protocols to facilitate data validation and interlaboratory comparison—as well as approaches to protocol design to extend the suite of viruses that FVM can feasibly and efficiently monitor. In the npj Clean Water article "Flow virometry for water-quality assessment: Protocol optimization for a model virus and automation of data analysis," we address these needs by first optimizing a sample-preparation protocol for a model virus (T4 bacteriophage) using a fractional factorial experimental design. We then compare manual and algorithmic methods of analyzing complex FCM data collected by applying the optimized protocol to (i) a clean solution spiked with a variety of biological and non-biological viral surrogates [mixed-target experiment], and (ii) tertiary treated wastewater effluent spiked with T4 bacteriophage and two sizes of fluorescent polystyrene beads [environmental spike experiment]. This repository contains the FCM data used to develop the optimized protocol and to test the two analytical methods.For our analysis, we used the following tools: FlowJoTM 10 software (Becton Dixon & Company) to manually open and analyze the .fcs files, and to convert these files to .csv files where needed; Rstudio (version 2021.9.1.372) for downstream analysis of results and data obtained using FlowJo; MATLAB® software (version R2021a; MathWorks) to perform additional downstream analysis; and Excel (version 16.68; Microsoft) to manually inspect the .csv files. A list of free and open-source alternative programs that can be used to analyze the .fcs files contained in this repository can be found at https://floreada.io/flow-cytometry-software. A variety of free and open-source alternative programs (e.g., Google Sheets) exist to analyze the .csv files contained in this repository. For the optimization experiments, subsequent direct analysis of these data (manual gating and calculation of the number, mean fluorescence intensity, and coefficient of variation of all gated particles) was performed using FlowJoTM 10 software (Becton Dixon & Company). The FrF2 package in Rstudio (version 2021.9.1.372) was then used to quantify the main and two-way interaction effects of each factor tested in the optimization. Documentation for this package is available at https://www.rdocumentation.org/packages/FrF2/versions/2.1/topics/FrF2-package. For the mixed-target and environmental spike experiments, subsequent direct analysis of these data through manual gating was performed using the same FlowJo software. The FlowJo software was then used to export the gated data to .csv files, FlowJoTM 10 software. A log transformation was applied to these data, after which features were standardized by centering and rescaling to standard deviation 1. Rstudio (version 2021.9.1.372) was used to apply the OPTICS implementation available in the dbscan package (Hahsler et al. 2019). MATLAB® software (version R2021a; MathWorks) was then used to inspect reachability plots of the OPTICS-ordered data for manual extraction. Finally, we applied the opticskxi package available in R (Charlton 2019) for automated extraction, with parameters described in the companion article to this dataset.Funding provided by: Bureau of ReclamationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100006450Award Number: Award R18AC00106All data were collected by analyzing a 10-mL volume of the sample in question using the 488 nm (blue) solid-state laser, the lowest possible instrument flowrate (5 mL/min), and a FITC = 800 threshold on a NovoCyte 2070V Flow Cytometer coupled with a NovoSampler Pro autosampler (Agilent). Green fluorescence (FITC) intensity was collected at 530 ± 30 nm; forward and side scatter (FSC and SSC) intensities were collected as well. For the optimization experiments, 10 mL of an unstained control was run after each sample. The instrument was flushed in between each sample and control by running 150 mL of 1x NovoClean solution (Agilent) followed by 150 mL of MQ water through the SIP at the highest instrument flow rate (120 mL/min). Instrument performance was ensured by performing the instrument's built-in quality control (QC) test at least monthly. The FCM data were exported directly to .fcs (the standard format for flow cytometry/virometry data) files. All of the raw .fcs files used for the optimization experiments, mixed-target experiments, and environmental spike experiments are provided in this repository. For the mixed-target and environmental spike experiments, these .fcs files were then manually gated and exported to .csv files for use in downstream, algorithmically assisted analysis. Each of these .csv files is provided in this repository as well
    corecore