621 research outputs found
Environmental Litigation in Historical Perspective
During the past several decades, litigation has played a major role in the attempt by citizens to realize environmental objectives. Its impact has been elaborated extensively in the vast array of writing in law journals as well as in the cases themselves. Most analyses have focused on specialized subjects of either substantive policy or legal procedure. In this brief Essay I attempt a more comprehensive overview involving two background factors- the growth of environmental values since World War II and the response of governmental institutions to the resulting demands placed upon them. Among these institutions were the courts. Their role cannot be understood simply in terms of the evolution of judicial opinion, but more in terms of the response of judges and the legal profession to changing public attitudes, legislative policies, scientific knowledge, and technical capabilities
Synaptic motor adaptation: A three-factor learning rule for adaptive robotic control in spiking neural networks
Legged robots operating in real-world environments must possess the ability
to rapidly adapt to unexpected conditions, such as changing terrains and
varying payloads. This paper introduces the Synaptic Motor Adaptation (SMA)
algorithm, a novel approach to achieving real-time online adaptation in
quadruped robots through the utilization of neuroscience-derived rules of
synaptic plasticity with three-factor learning. To facilitate rapid adaptation,
we meta-optimize a three-factor learning rule via gradient descent to adapt to
uncertainty by approximating an embedding produced by privileged information
using only locally accessible onboard sensing data. Our algorithm performs
similarly to state-of-the-art motor adaptation algorithms and presents a clear
path toward achieving adaptive robotics with neuromorphic hardware
Remembering Harry Pratter (1917-2002)
At this year\u27s annual Alumni Weekend, colleagues, family, friends, and former students of the inimitable Professor Harry Pratter, who died in March 2002, gathered to share their recollections of his life and career.
Pratter, who was born in the Ukraine and emigrated to the United States as a child, began teaching at the Law School in 1950, after earning his JD from the University of Chicago. He taught many different subjects, including Commercial Law, Negotiable Instruments, Conflicts of Law, Contracts, Torts, and Family Law. But more fundamentally, he taught life, according to Professor Fred Aman, longtime dean of the school.
For Harry, says Aman, there was no such thing as just a legal problem. There were only human problems with which the law must deal. The following remembrances were presented by Pratter\u27s former students
Remembering Harry Pratter (1917-2002)
At this year\u27s annual Alumni Weekend, colleagues, family, friends, and former students of the inimitable Professor Harry Pratter, who died in March 2002, gathered to share their recollections of his life and career.
Pratter, who was born in the Ukraine and emigrated to the United States as a child, began teaching at the Law School in 1950, after earning his JD from the University of Chicago. He taught many different subjects, including Commercial Law, Negotiable Instruments, Conflicts of Law, Contracts, Torts, and Family Law. But more fundamentally, he taught life, according to Professor Fred Aman, longtime dean of the school.
For Harry, says Aman, there was no such thing as just a legal problem. There were only human problems with which the law must deal. The following remembrances were presented by Pratter\u27s former students
Bosonic Mott insulator in WSe2/WS2 moir\'e superlattice
A panoply of unconventional electronic states is recently observed in moir\'e
superlattices. On the other hand, similar opportunities to engineer bosonic
phases remain largely unexplored. Here we report the observation of a bosonic
Mott insulator in WSe2/WS2 moir\'e superlattices composed of excitons, i.e.,
tightly bound electron-hole pairs. Using a novel pump probe spectroscopy, we
find an exciton incompressible state at exciton filling v_ex = 1 and charge
neutrality, which we assign to a bosonic Mott insulator. When further varying
charge density, the bosonic Mott insulator continuously transitions into an
electron Mott insulator at charge filling v_e = 1, suggesting a mixed Mott
insulating state in between. Our observations are well captured by a mixed
Hubbard model involving both fermionic and bosonic components, from which we
extract the on-site Coulomb repulsion to be 15meV and 35meV for exciton-exciton
and electron-exciton interactions, respectively. Our studies establish
semiconducting moir\'e superlattices as intriguing platforms for engineering
novel bosonic phases.Comment: 25 pages, 4+10 figure
Harmonization-enriched domain adaptation with light fine-tuning for multiple sclerosis lesion segmentation
Deep learning algorithms utilizing magnetic resonance (MR) images have
demonstrated cutting-edge proficiency in autonomously segmenting multiple
sclerosis (MS) lesions. Despite their achievements, these algorithms may
struggle to extend their performance across various sites or scanners, leading
to domain generalization errors. While few-shot or one-shot domain adaptation
emerges as a potential solution to mitigate generalization errors, its efficacy
might be hindered by the scarcity of labeled data in the target domain. This
paper seeks to tackle this challenge by integrating one-shot adaptation data
with harmonized training data that incorporates labels. Our approach involves
synthesizing new training data with a contrast akin to that of the test domain,
a process we refer to as "contrast harmonization" in MRI. Our experiments
illustrate that the amalgamation of one-shot adaptation data with harmonized
training data surpasses the performance of utilizing either data source in
isolation. Notably, domain adaptation using exclusively harmonized training
data achieved comparable or even superior performance compared to one-shot
adaptation. Moreover, all adaptations required only minimal fine-tuning,
ranging from 2 to 5 epochs for convergence
A life in progress: motion and emotion in the autobiography of Robert M. La Follette
This article is a study of a La Follette’s Autobiography, the autobiography of the leading Wisconsin progressive Robert M. La Follette, which was published serially in 1911 and, in book form, in 1913. Rather than focusing, as have other historians, on which parts of La Follette’s account are accurate and can therefore be trusted, it explains instead why and how this major autobiography was conceived and written. The article shows that the autobiography was the product of a sustained, complex, and often fraught series of collaborations among La Follette’s family, friends, and political allies, and in the process illuminates the importance of affective ties as well as political ambition and commitment in bringing the project to fruition. In the world of progressive reform, it argues, personal and political experiences were inseparable
Structural basis for arginine glycosylation of host substrates by bacterial effector proteins
The bacterial effector proteins SseK and NleB glycosylate host proteins on arginine residues, leading to reduced NF-κB-dependent responses to infection. Salmonella SseK1 and SseK2 are E. coli NleB1 orthologs that behave as NleB1-like GTs, although they differ in protein substrate specificity. Here we report that these enzymes are retaining glycosyltransferases composed of a helix-loop-helix (HLH) domain, a lid domain, and a catalytic domain. A conserved HEN motif (His-Glu-Asn) in the active site is important for enzyme catalysis and bacterial virulence. We observe differences between SseK1 and SseK2 in interactions with substrates and identify substrate residues that are critical for enzyme recognition. Long Molecular Dynamics simulations suggest that the HLH domain determines substrate specificity and the lid-domain regulates the opening of the active site. Overall, our data suggest a front-face SNi mechanism, explain differences in activities among these effectors, and have implications for future drug development against enteric pathogens
A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope
Globular clusters with their large populations of millisecond pulsars (MSPs)
are believed to be potential emitters of high-energy gamma-ray emission. Our
goal is to constrain the millisecond pulsar populations in globular clusters
from analysis of gamma-ray observations. We use 546 days of continuous
sky-survey observations obtained with the Large Area Telescope aboard the Fermi
Gamma-ray Space Telescope to study the gamma-ray emission towards 13 globular
clusters. Steady point-like high-energy gamma-ray emission has been
significantly detected towards 8 globular clusters. Five of them (47 Tucanae,
Omega Cen, NGC 6388, Terzan 5, and M 28) show hard spectral power indices and clear evidence for an exponential cut-off in the range
1.0-2.6 GeV, which is the characteristic signature of magnetospheric emission
from MSPs. Three of them (M 62, NGC 6440 and NGC 6652) also show hard spectral
indices , however the presence of an exponential cut-off
can not be unambiguously established. Three of them (Omega Cen, NGC 6388, NGC
6652) have no known radio or X-ray MSPs yet still exhibit MSP spectral
properties. From the observed gamma-ray luminosities, we estimate the total
number of MSPs that is expected to be present in these globular clusters. We
show that our estimates of the MSP population correlate with the stellar
encounter rate and we estimate 2600-4700 MSPs in Galactic globular clusters,
commensurate with previous estimates. The observation of high-energy gamma-ray
emission from a globular cluster thus provides a reliable independent method to
assess their millisecond pulsar populations that can be used to make
constraints on the original neutron star X-ray binary population, essential for
understanding the importance of binary systems in slowing the inevitable core
collapse of globular clusters.Comment: Accepted for publication in A&A. Corresponding authors: J.
Kn\"odlseder, N. Webb, B. Pancraz
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