18,647 research outputs found
The Opioid Crisis in Rural and Small Town America
In this brief, authors Shannon Monnat and Khary Rigg examine rural versus urban differences in opioid mortality and identify challenges for dealing with the opioid crisis in rural areas. They report that, in 2016, opioid mortality rates were higher in urban than in rural counties, particularly in the Midwest, but rates have increased more in rural than in urban counties over the past two decades. Since 2010, the share of drug overdose deaths involving prescription opioids has declined, but the share of deaths involving heroin and synthetic opioids has spiked in both rural and urban areas. The most dramatic increases in opioid deaths were in the rural Midwest, where they were 16 times higher in 2016 than in 1999, and in the rural Northeast, where they were 11.4 times higher. Prescription opioids are involved in a larger share of rural than urban drug overdose deaths, whereas heroin and synthetic opioids (such as fentanyl) account for a larger share of urban deaths. Over half of drug overdose deaths involve multiple drugs. Policy initiatives to date have been largely ineffective at addressing the opioid crisis in many of the hardest-hit rural communities, and the recent surge in fentanyl overdoes in large urban areas may be a precursor of what to expect in at-risk rural communities in the coming years. Existing interventions are unlikely to be effective without addressing the underlying social and economic factors that are plaguing the hardest-hit areas
Genetic Diversity and Potential Function of Microbial Symbionts Associated with Newly Discovered Species of Osedax Polychaete Worms
We investigated the genetic diversity of symbiotic bacteria associated with two newly discovered species of Osedax from Monterey Canyon, CA, at 1,017-m (Osedax Monterey Bay sp. 3 "rosy" [Osedax sp. MB3]) and 381-m (Osedax Monterey Bay sp. 4 "yellow collar") depths. Quantitative PCR and clone libraries of 16S rRNA gene sequences identified differences in the compositions and abundances of bacterial phylotypes associated with the newly discovered host species and permitted comparisons between adult Osedax frankpressi and juveniles that had recently colonized whalebones implanted at 2,891 m. The newly discovered Osedax species hosted Oceanospirillales symbionts that are related to Gammaproteobacteria associated with the previously described O. frankpressi and Osedax rubiplumus (S. K. Goffredi, V. J. Orphan, G. W. Rouse, L. Jahnke, T. Embaye, K. Turk, R. Lee, and R. C. Vrijenhoek, Environ. Microbiol. 7:1369-1378, 2005). In addition, Osedax sp. MB3 hosts a diverse and abundant population of additional bacteria dominated by Epsilonproteobacteria. Ultrastructural analysis of symbiont-bearing root tissues verified the enhanced microbial diversity of Osedax sp. MB3. Root tissues from the newly described host species and O. frankpressi all exhibited collagenolytic enzyme activity, which covaried positively with the abundance of symbiont DNA and negatively with mean adult size of the host species. Members of this unusual genus of bone-eating worms may form variable associations with symbiotic bacteria that allow for the observed differences in colonization and success in whale fall environments throughout the world's oceans
CRLF2 rearrangement in Ph-like acute lymphoblastic leukemia predicts relative glucocorticoid resistance that is overcome with MEK or Akt inhibition.
Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a genetically heterogeneous subtype of B-cell ALL characterized by chromosomal rearrangements and mutations that result in aberrant cytokine receptor and kinase signaling. In particular, chromosomal rearrangements resulting in the overexpression of cytokine receptor-like factor 2 (CRLF2) occur in 50% of Ph-like ALL cases. CRLF2 overexpression is associated with particularly poor clinical outcomes, though the molecular basis for this is currently unknown. Glucocorticoids (GCs) are integral to the treatment of ALL and GC resistance at diagnosis is an important negative prognostic factor. Given the importance of GCs in ALL therapy and the poor outcomes for patients with CRLF2 overexpression, we hypothesized that the aberrant signal transduction associated with CRLF2 overexpression might mediate intrinsic GC insensitivity. To test this hypothesis, we exposed Ph-like ALL cells from patient-derived xenografts to GCs and found that CRLF2 rearranged (CRLF2R) leukemias uniformly demonstrated reduced GC sensitivity in vitro. Furthermore, targeted inhibition of signal transduction with the MEK inhibitor trametinib and the Akt inhibitor MK2206, but not the JAK inhibitor ruxolitinib, was sufficient to augment GC sensitivity. These data suggest that suboptimal GC responses may in part underlie the poor clinical outcomes for patients with CRLF2 overexpression and provide rationale for combination therapy involving GCs and signal transduction inhibitors as a means of enhancing GC efficacy
Configurational entropy of network-forming materials
We present a computationally efficient method to calculate the
configurational entropy of network-forming materials. The method requires only
the atomic coordinates and bonds of a single well-relaxed configuration. This
is in contrast to the multiple simulations that are required for other methods
to determine entropy, such as thermodynamic integration. We use our method to
obtain the configurational entropy of well-relaxed networks of amorphous
silicon and vitreous silica. For these materials we find configurational
entropies of 1.02 kb and 0.97 kb per silicon atom, respectively, with kb the
Boltzmann constant.Comment: 4 pages, 4 figure
Light Element Synthesis in High Entropy Relativistic Flows Associated with Gamma Ray Bursts
We calculate and discuss the light element freeze-out nucleosynthesis in high
entropy winds and fireballs for broad ranges of entropy-per-baryon, dynamic
timescales characterizing relativistic expansion, and neutron-to-proton ratios.
With conditions characteristic of Gamma Ray Bursts (GRBs) we find that
deuterium production can be prodigious, with final abundance values 2H/H
approximately 2%, depending on the fireball isospin, late time dynamics, and
the effects of neutron decoupling- induced high energy non-thermal nuclear
reactions. This implies that there potentially could be detectable local
enhancements in the deuterium abundance associated with GRB events.Comment: 14 pages 3 figure
Seeing the light : experimental signatures of emergent electromagnetism in a quantum spin ice
The "spin ice" state found in the rare earth pyrochlore magnets Ho2Ti2O7 and
Dy2Ti2O7 offers a beautiful realisation of classical magnetostatics, complete
with magnetic monopole excitations. It has been suggested that in "quantum spin
ice" materials, quantum-mechanical tunnelling between different ice
configurations could convert the magnetostatics of spin ice into a quantum spin
liquid which realises a fully dynamical, lattice-analogue of quantum
electromagnetism. Here we explore how such a state might manifest itself in
experiment, within the minimal microscopic model of a such a quantum spin ice.
We develop a lattice field theory for this model, and use this to make explicit
predictions for the dynamical structure factor which would be observed in
neutron scattering experiments on a quantum spin ice. We find that "pinch
points", seen in quasi-elastic scattering, which are the signal feature of a
classical spin ice, fade away as a quantum ice is cooled to its
zero-temperature ground state. We also make explicit predictions for the
ghostly, linearly dispersing magnetic excitations which are the "photons" of
this emergent electromagnetism. The predictions of this field theory are shown
to be in quantitative agreement with Quantum Monte Carlo simulations at zero
temperature.Comment: 26 pages, 18 figures, minor revision
Information preserving structures: A general framework for quantum zero-error information
Quantum systems carry information. Quantum theory supports at least two
distinct kinds of information (classical and quantum), and a variety of
different ways to encode and preserve information in physical systems. A
system's ability to carry information is constrained and defined by the noise
in its dynamics. This paper introduces an operational framework, using
information-preserving structures to classify all the kinds of information that
can be perfectly (i.e., with zero error) preserved by quantum dynamics. We
prove that every perfectly preserved code has the same structure as a matrix
algebra, and that preserved information can always be corrected. We also
classify distinct operational criteria for preservation (e.g., "noiseless",
"unitarily correctible", etc.) and introduce two new and natural criteria for
measurement-stabilized and unconditionally preserved codes. Finally, for
several of these operational critera, we present efficient (polynomial in the
state-space dimension) algorithms to find all of a channel's
information-preserving structures.Comment: 29 pages, 19 examples. Contains complete proofs for all the theorems
in arXiv:0705.428
Dirt in Your Soul: An Exhibit Plan
This project is based on the Vermont Folklife Center’s research documenting grassroots food and agriculture in Vermont. The Library of Congress Archie Green Fellowship generously funded this research. Over the course of approximately 18 months, the research team traveled across Vermont to conduct 22 qualitative interviews with a cross-section of Vermont’s food system stakeholders. Additionally, the team dedicated 6 site visits to capturing photographic, audio, and video content from a variety of food producers. The ultimate goal of this research is to create a traveling exhibit featuring the story of Vermont’s modern, changing food system.
This report is designed to help inform members of the Vermont Folklife Center and others involved in their work about the potential and recommended approaches to executing an exhibit for their Archie Green Fellowship project. The intention is for this report to become a resource for all involved with the Archie Green Project
Some Observations for Mean-Field Spin Glass Models
We obtain bounds to show that the pressure of a two-body, mean-field spin
glass is a Lipschitz function of the underlying distribution of the random
coupling constants, with respect to a particular semi-norm. This allows us to
re-derive a result of Carmona and Hu, on the universality of the SK model, by a
different proof, and to generalize this result to the Viana-Bray model. We also
prove another bound, suitable when the coupling constants are not independent,
which is what is necessary if one wants to consider ``canonical'' instead of
``grand canonical'' versions of the SK and Viana-Bray models. Finally, we
review Viana-Bray type models, using the language of L\'evy processes, which is
natural in this context.Comment: 15 pages, minor revision
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