287 research outputs found
Building Environmentally Sustainable Communities: A Framework for Inclusivity
Reviews literature on past inequitable and unsustainable urban development and visions for linking sustainability, opportunity, and inclusion. Analyzes possible metrics for measuring sustainability and access as well as next steps for policy
Toward the automated generation of genome-scale metabolic networks in the SEED
<p>Abstract</p> <p>Background</p> <p>Current methods for the automated generation of genome-scale metabolic networks focus on genome annotation and preliminary biochemical reaction network assembly, but do not adequately address the process of identifying and filling gaps in the reaction network, and verifying that the network is suitable for systems level analysis. Thus, current methods are only sufficient for generating draft-quality networks, and refinement of the reaction network is still largely a manual, labor-intensive process.</p> <p>Results</p> <p>We have developed a method for generating genome-scale metabolic networks that produces substantially complete reaction networks, suitable for systems level analysis. Our method partitions the reaction space of central and intermediary metabolism into discrete, interconnected components that can be assembled and verified in isolation from each other, and then integrated and verified at the level of their interconnectivity. We have developed a database of components that are common across organisms, and have created tools for automatically assembling appropriate components for a particular organism based on the metabolic pathways encoded in the organism's genome. This focuses manual efforts on that portion of an organism's metabolism that is not yet represented in the database. We have demonstrated the efficacy of our method by reverse-engineering and automatically regenerating the reaction network from a published genome-scale metabolic model for <it>Staphylococcus aureus</it>. Additionally, we have verified that our method capitalizes on the database of common reaction network components created for <it>S. aureus</it>, by using these components to generate substantially complete reconstructions of the reaction networks from three other published metabolic models (<it>Escherichia coli</it>, <it>Helicobacter pylori</it>, and <it>Lactococcus lactis</it>). We have implemented our tools and database within the SEED, an open-source software environment for comparative genome annotation and analysis.</p> <p>Conclusion</p> <p>Our method sets the stage for the automated generation of substantially complete metabolic networks for over 400 complete genome sequences currently in the SEED. With each genome that is processed using our tools, the database of common components grows to cover more of the diversity of metabolic pathways. This increases the likelihood that components of reaction networks for subsequently processed genomes can be retrieved from the database, rather than assembled and verified manually.</p
MTORC1 signaling and regulation of pancreatic β-cell mass
The capacity of β cells to expand in response to insulin resistance is a critical factor in the development of type 2 diabetes. Proliferation of β cells is a major component for these adaptive responses in animal models. The extracellular signals responsible for β-cell expansion include growth factors, such as insulin, and nutrients, such as glucose and amino acids. AKT activation is one of the important components linking growth signals to the regulation of β-cell expansion. Downstream of AKT, tuberous sclerosis complex 1 and 2 (TSC1/2) and mechanistic target of rapamycin complex 1 (mTORC1) signaling have emerged as prime candidates in this process, because they integrate signals from growth factors and nutrients. Recent studies demonstrate the importance of mTORC1 signaling in β cells. This review will discuss recent advances in the understanding of how this pathway regulates β-cell mass and present data on the role of TSC1 in modulation of β-cell mass. Herein, we also demonstrate that deletion of Tsc1 in pancreatic β cells results in improved glucose tolerance, hyperinsulinemia and expansion of β-cell mass that persists with aging
Cost-effectiveness of Implementing Low-Tidal Volume Ventilation in Patients With Acute Lung Injury
Background: Despite widespread guidelines recommending the use of lung-protective ventilation (LPV) in patients with acute lung injury (ALI), many patients do not receive this lifesaving therapy. We sought to estimate the incremental clinical and economic outcomes associated with LPV and determined the maximum cost of a hypothetical intervention to improve adherence with LPV that remained cost-effective.
Methods: Adopting a societal perspective, we developed a theoretical decision model to determine the cost-effectiveness of LPV compared to non-LPV care. Model inputs were derived from the literature and a large population-based cohort of patients with ALI. Cost-effectiveness was determined as the cost per life saved and the cost per quality-adjusted life-years (QALYs) gained.
Results: Application of LPV resulted in an increase in QALYs gained by 15% (4.21 years for non-LPV vs 4.83 years for LPV), and an increase in lifetime costs of 99,588 for non-LPV vs 22,566 per life saved at hospital discharge and 9,482. Results were robust to a wide range of economic and patient parameter assumptions.
Conclusions: Even a costly intervention to improve adherence with low-tidal volume ventilation in patients with ALI reduces death and is cost-effective by current societal standards.NIH F32HL090220.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84154/1/Cooke - CEA LPV.pd
Topological band inversion in HgTe(001): surface and bulk signatures from photoemission
HgTe is a versatile topological material and has enabled the realization of a
variety of topological states, including two- and three-dimensional (3D)
topological insulators and topological semimetals. Nevertheless, a quantitative
understanding of its electronic structure remains challenging, in particular
due to coupling of the Te 5p-derived valence electrons to Hg 5d core states at
shallow binding energy. We present a joint experimental and theoretical study
of the electronic structure in strained HgTe(001) films in the 3D
topological-insulator regime, based on angle-resolved photoelectron
spectroscopy and density functional theory. The results establish detailed
agreement in terms of (i) electronic band dispersions and orbital symmetries,
(ii) surface and bulk contributions to the electronic structure, and (iii) the
importance of Hg 5d states in the valence-band formation. Supported by theory,
our experiments directly image the paradigmatic band inversion in HgTe,
underlying its non-trivial band topology
Audible Image Description as an Accommodation in Statewide Assessments for Students with Visual and Print Disabilities.
Introduction:Although image description has been identified as an accommodation for presentations conducted in the classroom, only a few U.S. states have approved it for use in high-stakes assessments. This study examined the use of audible image description as an assessment accommodation for students with visual and print disabilities by investigating student comprehension under multiple conditions. Methods: Students in three western states in grades three through eight who had visual (n= 117) or print (n= 178) disabilities participated in an abbreviated test constructed of retired assessment questions in English language arts, mathematics, and science, that were aligned with each state's instructional standards, under conditions with and without standardized description of graphic images. The study used a within-subjects block design to collect and compare comprehension data under conditions where audible image description was both used and not used in an abbreviated test. Results: Results indicated that students who read braille were more likely to
respond correctly under the audible image description condition, and students
with visual and print disabilities who used print were equally likely to respond
correctly regardless of condition. Discussion: Braille readers were more likely to
obtain a correct answer when audible image description accompanied the question.
Audible image description did not affect the likelihood of a correct response
from students with print disabilities or students with visual disabilities who read
print. Implications for practitioners: Audible image description is an accommodation
that may help braille readers perform better on tests. Although the
Partnership for Assessment of Readiness for College and Careers (PARCC) and
Smarter Balanced consortia are taking steps to include image (or picture) descriptions
in their assessment accommodations, teachers may want to develop a standard method for describing images and familiarize their braille readers to the strategy by
including it in instruction and in classroom tests. Readers are referred to the National
Center on Accessible Media’s online guidelines for image description
Partitioning of Minimotifs Based on Function with Improved Prediction Accuracy
Background: Minimotifs are short contiguous peptide sequences in proteins that are known to have a function in at least one other protein. One of the principal limitations in minimotif prediction is that false positives limit the usefulness of this approach. As a step toward resolving this problem we have built, implemented, and tested a new data-driven algorithm that reduces false-positive predictions. Methodology/Principal Findings: Certain domains and minimotifs are known to be strongly associated with a known cellular process or molecular function. Therefore, we hypothesized that by restricting minimotif predictions to those where the minimotif containing protein and target protein have a related cellular or molecular function, the prediction is more likely to be accurate. This filter was implemented in Minimotif Miner using function annotations from the Gene Ontology. We have also combined two filters that are based on entirely different principles and this combined filter has a better predictability than the individual components. Conclusions/Significance: Testing these functional filters on known and random minimotifs has revealed that they are capable of separating true motifs from false positives. In particular, for the cellular function filter, the percentage of known minimotifs that are not removed by the filter is,4.6 times that of random minimotifs. For the molecular function filter this ratio is,2.9. These results, together with the comparison with the published frequency score filter, strongly suggest tha
WHS Guidelines for the Treatment of Pressure Ulcers: 2023 Update
The major populations at risk for developing pressure ulcers are older adults who have multiple risk factors that increase their vulnerability, people who are critically ill and those with spinal cord injury/disease. The reported prevalence of pressure ulcers in the United States is 2.5 million. However, this estimate is derived from acute care facilities and does not include people who are living at home or in nursing facilities. Despite the implementation of hospital and facility-based preventive measures, the incidence of pressure ulcers has not decreased in decades. In addition to the burden of pain, infection and death, it is estimated that hospital-acquired pressure ulcers cost the health system $26.8 billion annually with over 50% of the cost attributed to treating Stage 3 and 4 pressure injuries. Thus, it is critical to examine the literature and develop guidelines that will improve the outcomes of this complex and costly condition. This guideline update is a compendium of the best available evidence for the treatment of Pressure Ulcers published since the last update in 2015 and includes a new section based on changing demographics entitled ‘Palliative wound care for seriously ill patients with pressure ulcers’. The overall goal of the Wound Healing Society Guideline project is to present clear, concise and commercial free guidelines that clinicians can use to guide care, that researchers can use to develop studies that will improve treatment and that both clinicians and researchers can use to understand the gaps in our knowledge base
- …