25 research outputs found
The Case for Climate Conscious, Low Carbon Federal Procurement
Purchasing practices are one of many contributors to the climate crisis. As the world’s largest purchaser of goods and services, the U.S. Federal Government is in a unique position to cut a significant portion of national emissions through the development of more responsible, sustainable, and—most importantly—climate-conscious supply chains. According to the Office of the Federal Chief Sustainability Officer, federal supply chain emissions associated with federal contracts are twice as high as Federal Scope 1 and Scope 2 emissions, combined. As such, reforming Federal procurement practices to limit direct emissions as well as emissions in supply chains can play a crucial role in reaching the goal of net-zero emissions by 2050.
The Biden Administration has taken a strong stance on climate change, initiating, reinstating, and further developing necessary policy adjustments such as transitioning the government fleet to electric vehicles, supporting energy efficiency in buildings, and the uptake in renewable energy generation, and drafting a new Federal Sustainability Plan. The RCRC Committee has prepared recommendations relevant to Federal procurement practices to help achieve maximum emissions reductions at both the government and national levels
Dark Matter in 3D
We discuss the relevance of directional detection experiments in the
post-discovery era and propose a method to extract the local dark matter phase
space distribution from directional data. The first feature of this method is a
parameterization of the dark matter distribution function in terms of integrals
of motion, which can be analytically extended to infer properties of the global
distribution if certain equilibrium conditions hold. The second feature of our
method is a decomposition of the distribution function in moments of a model
independent basis, with minimal reliance on the ansatz for its functional form.
We illustrate our method using the Via Lactea II N-body simulation as well as
an analytical model for the dark matter halo. We conclude that O(1000) events
are necessary to measure deviations from the Standard Halo Model and constrain
or measure the presence of anisotropies.Comment: 36 pages, 13 figure
The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2
Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701
Colonization of the Beaufort Coastal Plain by Beaver (Castor canadensis): A Response to Shrubification of the Tundra?
A consequence of rapid global warming has been the shrubification (increase in shrub abundance, cover, and biomass) of arctic and alpine tundra ecosystems. Shrubification is likely a key driver of predicted and observed changes in the biodiversity of the Arctic. The American Beaver (Castor canadensis) has a vast distributional range, covering most of north America below the tree line; however, it has not been recorded in tundra habitat of the Beaufort Coastal Plain of Yukon and Alaska. in 2015, we observed a beaver dam, lodge, and winter food cache on the Babbage River in Ivvavik National Park, Yukon, Canada. Local Inuvialuit hunters first observed beavers on two rivers immediately east of the Babbage River in 2008 and 2009. Together, these are the first observations of beavers on the Beaufort Coastal Plain and indicate initial attempts at colonization. Colonization of the Beaufort Coastal Plain by beavers may have been facilitated by shrubification of river valleys on the tundra of northern Yukon and adjacent Alaska, which is a consequence of rapid climate warming in the western Arctic
Reactivity of Electronically Excited SO<sub>2</sub> with Alkanes
We studied the reaction
of electronically excited sulfur dioxide
in the triplet state (3SO2) with a variety of
alkane species, including propane, n-butane, isobutane, n-pentane, n-hexane, cyclohexane, n-octane, and n-nonane. Reaction rate constants
for the photoinitiated reaction of SO2 with all of these
species were determined and found to be in the range from 3.7 Ă—
10–13 to 5.1 × 10–12 cm3molecule–1s–1. We found
that reaction proceeds via a hydrogen abstraction to form HOSO•
and organic radical (R•) species and that reactivity is correlated
with the energy required to break a C–H bond and the length
of the alkane chain. Abstraction rates were found to be fastest for
reaction with hydrogen on a tertiary carbon. Similarly, abstraction
from secondary carbons is found to be faster than from primary carbons.
The reactivity of 3SO2 with alkanes increases
with chain length as additional secondary carbons are added
Atmospheric Hydroxyl Radical Source: Reaction of Triplet SO<sub>2</sub> and Water
The
reaction of electronically excited triplet state sulfur dioxide
(<sup>3</sup>SO<sub>2</sub>) with water was investigated both theoretically
and experimentally. The quantum chemical calculations find that the
reaction leads to the formation of hydroxyl radical (OH) and hydroxysulfinyl
radical (HOSO) via a low energy barrier pathway. Experimentally the
formation of OH was monitored via its reaction with methane, which
itself is relatively unreactive with <sup>3</sup>SO<sub>2</sub>, making
it a suitable probe of OH production from the reaction of <sup>3</sup>SO<sub>2</sub> and water. This reaction has implications for the
formation of OH in environments that are assumed to be depleted in
OH, such as volcanic plumes. This reaction also provides a mechanism
for the formation of OH in planetary atmospheres with little or no
oxygen (O<sub>2</sub>) or ozone (O<sub>3</sub>) present
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teemi: An open-source literate programming approach for iterative design-build-test-learn cycles in bioengineering.
Synthetic biology dictates the data-driven engineering of biocatalysis, cellular functions, and organism behavior. Integral to synthetic biology is the aspiration to efficiently find, access, interoperate, and reuse high-quality data on genotype-phenotype relationships of native and engineered biosystems under FAIR principles, and from this facilitate forward-engineering strategies. However, biology is complex at the regulatory level, and noisy at the operational level, thus necessitating systematic and diligent data handling at all levels of the design, build, and test phases in order to maximize learning in the iterative design-build-test-learn engineering cycle. To enable user-friendly simulation, organization, and guidance for the engineering of biosystems, we have developed an open-source python-based computer-aided design and analysis platform operating under a literate programming user-interface hosted on Github. The platform is called teemi and is fully compliant with FAIR principles. In this study we apply teemi for i) designing and simulating bioengineering, ii) integrating and analyzing multivariate datasets, and iii) machine-learning for predictive engineering of metabolic pathway designs for production of a key precursor to medicinal alkaloids in yeast. The teemi platform is publicly available at PyPi and GitHub