4,538 research outputs found
Carbon Free Boston: Offsets Technical Report
Part of a series of reports that includes:
Carbon Free Boston: Summary Report;
Carbon Free Boston: Social Equity Report;
Carbon Free Boston: Technical Summary;
Carbon Free Boston: Buildings Technical Report;
Carbon Free Boston: Transportation Technical Report;
Carbon Free Boston: Waste Technical Report;
Carbon Free Boston: Energy Technical Report;
Available at http://sites.bu.edu/cfb/OVERVIEW:
The U.S. Environmental Protection Agency defines offsets as a specific activity or set of activities
intended to reduce GHG emissions, increase the storage of carbon, or enhance GHG removals from the
atmosphere [1]. From a city perspective, they provide a mechanism to negate residual GHG emissions—
those the city is unable to reduce directly—by supporting projects that avoid or sequester them outside
of the city’s reporting boundary.
Offsetting GHG emissions is a controversial topic for cities, as the co-benefits of the investment are
typically not realized locally. For this reason, offsetting emissions is considered a last resort, a strategy
option available when the city has exhausted all others. However, offsets are likely to be a necessity to
achieve carbon neutrality by 2050 and promote emissions reductions in the near term. While public and
private sector partners pursue the more complex systems transformation, cities can utilize offsets to
support short-term and relatively cost-effective reductions in emissions. Offsets can be a relatively
simple, certain, and high-impact way to support the transition to a low-carbon world.
This report focuses on carbon offset certificates, more often referred to as offsets. Each offset
represents a metric ton of verified carbon dioxide (CO2) or equivalent emissions that is reduced,
avoided, or permanently removed from the atmosphere (“sequestered”) through an action taken by the
creator of the offset. The certificates can be traded and retiring (that is, not re-selling) offsets can be a
useful component of an overall voluntary emissions reduction strategy, alongside activities to lower an
organization’s direct and indirect emissions. In the Global Protocol for Community-Scale Greenhouse Gas
Emissions Inventories (GPC), the GHG accounting system used by the City of Boston, any carbon offset
certificates that the City has can be deducted from the City’s total GHG emissions.http://sites.bu.edu/cfb/files/2019/06/CFB_Offsets_Technical_Report_051619.pdfPublished versio
Carbon Free Boston: Energy Technical Report
Part of a series of reports that includes:
Carbon Free Boston: Summary Report;
Carbon Free Boston: Social Equity Report;
Carbon Free Boston: Technical Summary;
Carbon Free Boston: Buildings Technical Report;
Carbon Free Boston: Transportation Technical Report;
Carbon Free Boston: Waste Technical Report;
Carbon Free Boston: Offsets Technical Report;
Available at http://sites.bu.edu/cfb/INTRODUCTION:
The adoption of clean energy in Boston’s buildings and transportation systems will produce sweeping
changes in the quantity and composition of the city’s demand for fuel and electricity. The demand for
electricity is expected to increase by 2050, while the demand for petroleum-based liquid fuels and
natural gas within the city is projected to decline significantly. The city must meet future energy demand
with clean energy sources in order to meet its carbon mitigation targets. That clean energy must be
procured in a way that supports the City’s goals for economic development, social equity, environmental
sustainability, and overall quality of life. This chapter examines the strategies to accomplish these goals.
Improved energy efficiency, district energy, and in-boundary generation of clean energy (rooftop PV)
will reduce net electric power and natural gas demand substantially, but these measures will not
eliminate the need for electricity and gas (or its replacement fuel) delivered into Boston. Broadly
speaking, to achieve carbon neutrality by 2050, the city must therefore (1) reduce its use of fossil fuels
to heat and cool buildings through cost-effective energy efficiency measures and electrification of
building thermal services where feasible; and (2) over time, increase the amount of carbon-free
electricity delivered to the city. Reducing energy demand though cost effective energy conservation
measures will be necessary to reduce the challenges associated with expanding the electricity delivery
system and sustainably sourcing renewable fuels.Published versio
The Final (Oral Ebola) Vaccine Trial on Captive Chimpanzees?
Could new oral vaccine technologies protect endangered wildlife against a rising tide of infectious disease? We used captive chimpanzees to test oral delivery of a rabies virus (RABV) vectored vaccine against Ebola virus (EBOV), a major threat to wild chimpanzees and gorillas. EBOV GP and RABV GP-specific antibody titers increased exponentially during the trial, with rates of increase for six orally vaccinated chimpanzees very similar to four intramuscularly vaccinated controls. Chimpanzee sera also showed robust neutralizing activity against RABV and pseudo-typed EBOV. Vaccination did not induce serious health complications. Blood chemistry, hematologic, and body mass correlates of psychological stress suggested that, although sedation induced acute stress, experimental housing conditions did not induce traumatic levels of chronic stress. Acute behavioral and physiological responses to sedation were strongly correlated with immune responses to vaccination. These results suggest that oral vaccination holds great promise as a tool for the conservation of apes and other endangered tropical wildlife. They also imply that vaccine and drug trials on other captive species need to better account for the effects of stress on immune response
Composing Efficient, Robust Tests for Policy Selection
Modern reinforcement learning systems produce many high-quality policies
throughout the learning process. However, to choose which policy to actually
deploy in the real world, they must be tested under an intractable number of
environmental conditions. We introduce RPOSST, an algorithm to select a small
set of test cases from a larger pool based on a relatively small number of
sample evaluations. RPOSST treats the test case selection problem as a
two-player game and optimizes a solution with provable -of- robustness,
bounding the error relative to a test that used all the test cases in the pool.
Empirical results demonstrate that RPOSST finds a small set of test cases that
identify high quality policies in a toy one-shot game, poker datasets, and a
high-fidelity racing simulator.Comment: 26 pages, 13 figures. To appear in Proceedings of the Thirty-Ninth
Conference on Uncertainty in Artificial Intelligence (UAI 2023
Culture of airway epithelial cells from neonates sampled within 48-hours of birth
Peer reviewedPublisher PD
Microfluidics on standard Petri dishes for bioscientists
Few microfluidic devices are used in biomedical labs, despite the obvious potential; reasons given include the devices are rarely made with cell-friendly materials, and liquids are inaccessibly buried behind solid confining walls. An open microfluidic approach is reviewed in which aqueous circuits with almost any imaginable 2D shape are fabricated in minutes on standard polystyrene Petri dishes by reshaping two liquids (cell-culture media plus an immiscible and bioinert fluorocarbon, FC40). Then, the aqueous phase becomes confined by fluid FC40 walls firmly pinned to the dish by interfacial forces. Such walls can be pierced at any point with pipets and liquids added or removed through them, while flows can be driven actively using external pumps or passively by exploiting local differences in Laplace pressure. As walls are robust, permeable to O2 plus CO2, and transparent, cells are grown in incubators and monitored microscopically as usual. It is hoped that this simple, accessible, and affordable fluid-shaping technology provides bioscientists with an easy entrée into microfluidics
Transcriptional responses in the adaptation to ischaemia-reperfusion injury: a study of the effect of ischaemic preconditioning in total knee arthroplasty patients
<p>Abstract</p> <p>Background</p> <p>Ischaemic preconditioning (IPC) has emerged as a method of reducing ischaemia-reperfusion injury. However, the complex mechanism through which IPC elicits this protection is not fully understood. The aim of this study was to investigate the genomic response induced by IPC in muscle biopsies taken from the operative leg of total knee arthroplasty patients in order to gain insight into the IPC mechanism.</p> <p>Methods</p> <p>Twenty patients, undergoing primary total knee arthroplasty, were randomly assigned to IPC (n = 10) and control (n = 10) groups. Patients in the IPC group received ischaemic preconditioning immediately prior to surgery. IPC was induced by three five-minute cycles of tourniquet insufflation interrupted by five-minute cycles of reperfusion. A muscle biopsy was taken from the operative knee of control and IPC-treated patients at the onset of surgery and, again, at one hour into surgery. The gene expression profile of muscle biopsies was determined using the Affymetrix Human U113 2.0 microarray system and validated using real-time polymerase chain reaction (RT-PCR). Measurements of C-reactive protein (CRP), erythrocyte sedimentation (ESR), white cell count (WCC), cytokines and haemoglobin were also made pre- and post-operatively.</p> <p>Results</p> <p>Microarray analysis revealed a significant increase in the expression of important oxidative stress defence genes, immediate early response genes and mitochondrial genes. Upregulation of pro-survival genes was also observed and correlated with a downregulation of pro-apoptotic gene expression. CRP, ESR, WCC, cytokine and haemoglobin levels were not significantly different between control and IPC patients.</p> <p>Conclusions</p> <p>The findings of this study suggest that IPC of the lower limb in total knee arthroplasty patients induces a protective genomic response, which results in increased expression of immediate early response genes, oxidative stress defence genes and pro-survival genes. These findings indicate that ischaemic preconditioning may be of potential benefit in knee arthroplasty and other musculoskeletal conditions.</p
Unraveling the Helix Nebula: Its Structure and Knots
Through HST imaging of the inner part of the main-ring of the Helix Nebula
together with CTIO 4-m images of the fainter outer parts, we have an
unprecedented-quality view of the nearest bright planetary nebula. These images
have allowed determination that the main-ring of the nebula is composed of an
inner-disk of about 499\arcsec diameter (0.52 pc) surrounded by an outer-ring
(in reality a torus) of 742\arcsec diameter (0.77 pc) whose plane is highly
inclined to the plane of the disk. This outer-ring is surrounded by an
outermost-ring of 1500\arcsec (1.76 pc) diameter which is flattened on the side
colliding with the ambient interstellar medium. The inner-disk has an extended
distribution of low density gas along its rotational axis of symmetry and the
disk is optically thick to ionizing radiation, as is the outer-ring.
Published radial velocities of the knots provides support for the
two-component structure of the main-ring of the nebula and to the idea that the
knots found there are expanding along with the nebular material from which it
recently originated. There is a change in the morphology of the knots as a
function of the distance from the local ionization front. This supports a
scenario in which the knots are formed in or near the ionization front and are
then sculpted by the stellar radiation from the central star as the ionization
front advances beyond them.Comment: 30 pages, 20 figures, many figures have reduce fidelity for astroph
preprint. Note: URLs in preprint were change
Anthropological and socioeconomic factors contributing to global antimicrobial resistance: a univariate and multivariable analysis
Background
Understanding of the factors driving global antimicrobial resistance is limited. We analysed antimicrobial resistance and antibiotic consumption worldwide versus many potential contributing factors.
Methods
Using three sources of data (ResistanceMap, the WHO 2014 report on antimicrobial resistance, and contemporary publications), we created two global indices of antimicrobial resistance for 103 countries using data from 2008 to 2014: Escherichia coli resistance—the global average prevalence of E coli bacteria that were resistant to third-generation cephalosporins and fluoroquinolones, and aggregate resistance—the combined average prevalence of E coli and Klebsiella spp resistant to third-generation cephalosporins, fluoroquinolones, and carbapenems, and meticillin-resistant Staphylococcus aureus. Antibiotic consumption data were obtained from the IQVIA MIDAS database. The World Bank DataBank was used to obtain data for governance, education, gross domestic product (GDP) per capita, health-care spending, and community infrastructure (eg, sanitation). A corruption index was derived using data from Transparency International. We examined associations between antimicrobial resistance and potential contributing factors using simple correlation for a univariate analysis and a logistic regression model for a multivariable analysis.
Findings
In the univariate analysis, GDP per capita, education, infrastructure, public health-care spending, and antibiotic consumption were all inversely correlated with the two antimicrobial resistance indices, whereas higher temperatures, poorer governance, and the ratio of private to public health expenditure were positively correlated. In the multivariable regression analysis (confined to the 73 countries for which antibiotic consumption data were available) considering the effect of changes in indices on E coli resistance (R2 0·54) and aggregate resistance (R2 0·75), better infrastructure (p=0·014 and p=0·0052) and better governance (p=0·025 and p<0·0001) were associated with lower antimicrobial resistance indices. Antibiotic consumption was not significantly associated with either antimicrobial resistance index in the multivariable analysis (p=0·64 and p=0·070).
Interpretation
Reduction of antibiotic consumption will not be sufficient to control antimicrobial resistance because contagion—the spread of resistant strains and resistance genes—seems to be the dominant contributing factor. Improving sanitation, increasing access to clean water, and ensuring good governance, as well as increasing public health-care expenditure and better regulating the private health sector are all necessary to reduce global antimicrobial resistance
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