106 research outputs found
INTERDEPENDENT INFRASTRUCTURE RESILIENCE IN THE U.S. VIRGIN ISLANDS: PRELIMINARY ASSESSMENT
Prepared for: Federal Emergency Management AgencyThe U.S. Virgin Islands (USVI) is a territory comprised of three main islands—Saint Croix, Saint John, and Saint Thomas—and a
number of smaller surrounding islands, located in the Leeward Islands of the Lesser Antilles approximately 40 miles east of Puerto
Rico and over 1,100 miles from Miami, Florida. In September 2017, two Category-5 hurricanes made landfall within a two-week
period and collectively devastated the homes, businesses, and infrastructure throughout the Territory.This technical report (1) explains
the structure, function, and tensions associated with energy, water, transportation, and communication infrastructure that were chronic
problems prior to the hurricanes; (2) documents hurricane response, recovery, and mitigation activities for these infrastructure systems
after the hurricanes; and (3) provides concrete approaches to overcome potential barriers to resilience (where they exist) and open
questions for research (where they do not yet exist).Federal Emergency Management AgencyFederal Emergency Management AgencyApproved for public release; distribution is unlimited
Multiscale modeling for fluid transport in nanosystems.
Atomistic-scale behavior drives performance in many micro- and nano-fluidic systems, such as mircrofludic mixers and electrical energy storage devices. Bringing this information into the traditionally continuum models used for engineering analysis has proved challenging. This work describes one such approach to address this issue by developing atomistic-to-continuum multi scale and multi physics methods to enable molecular dynamics (MD) representations of atoms to incorporated into continuum simulations. Coupling is achieved by imposing constraints based on fluxes of conserved quantities between the two regions described by one of these models. The impact of electric fields and surface charges are also critical, hence, methodologies to extend finite-element (FE) MD electric field solvers have been derived to account for these effects. Finally, the continuum description can have inconsistencies with the coarse-grained MD dynamics, so FE equations based on MD statistics were derived to facilitate the multi scale coupling. Examples are shown relevant to nanofluidic systems, such as pore flow, Couette flow, and electric double layer
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Enhanced molecular dynamics for simulating porous interphase layers in batteries.
Understanding charge transport processes at a molecular level using computational techniques is currently hindered by a lack of appropriate models for incorporating anistropic electric fields in molecular dynamics (MD) simulations. An important technological example is ion transport through solid-electrolyte interphase (SEI) layers that form in many common types of batteries. These layers regulate the rate at which electro-chemical reactions occur, affecting power, safety, and reliability. In this work, we develop a model for incorporating electric fields in MD using an atomistic-to-continuum framework. This framework provides the mathematical and algorithmic infrastructure to couple finite element (FE) representations of continuous data with atomic data. In this application, the electric potential is represented on a FE mesh and is calculated from a Poisson equation with source terms determined by the distribution of the atomic charges. Boundary conditions can be imposed naturally using the FE description of the potential, which then propagates to each atom through modified forces. The method is verified using simulations where analytical or theoretical solutions are known. Calculations of salt water solutions in complex domains are performed to understand how ions are attracted to charged surfaces in the presence of electric fields and interfering media
Combining Phylogeography with Distribution Modeling: Multiple Pleistocene Range Expansions in a Parthenogenetic Gecko from the Australian Arid Zone
Phylogenetic and geographic evidence suggest that many parthenogenetic organisms have evolved recently and have spread rapidly. These patterns play a critical role in our understanding of the relative merits of sexual versus asexual reproductive modes, yet their interpretation is often hampered by a lack of detail. Here we present a detailed phylogeographic study of a vertebrate parthenogen, the Australian gecko Heteronotia binoei, in combination with statistical and biophysical modeling of its distribution during the last glacial maximum. Parthenogenetic H. binoei occur in the Australian arid zone and have the widest range of any known vertebrate parthenogen. They are broadly sympatric with their sexual counterparts, from which they arose via hybridization. We have applied nested clade phylogeographic, effective migration, and mismatch distribution analyses to mitochondrial DNA (mtDNA) sequences obtained for 319 individuals sampled throughout the known geographic ranges of two parthenogenetic mitochondrial lineages. These analyses provide strong evidence for past range expansion events from west to east across the arid zone, and for continuing eastward range expansion. Parthenogen formation and range expansion events date to the late Pleistocene, with one lineage expanding from the northwest of its present range around 240,000 years ago and the second lineage expanding from the far west around 70,000 years ago. Statistical and biophysical distribution models support these inferences of recent range expansion, with suitable climatic conditions during the last glacial maximum most likely limited to parts of the arid zone north and west of much of the current ranges of these lineages. Combination of phylogeographic analyses and distribution modeling allowed considerably stronger inferences of the history of this complex than either would in isolation, illustrating the power of combining complementary analytical approaches
Structural epitope profiling identifies antibodies associated with critical COVID-19 and long COVID
Even within a single protein, antibody binding can have beneficial, neutral, or harmful effects during the response to infection. Resolving a polyclonal antibody repertoire across a pathogen’s proteome to specific epitopes may therefore explain much of the heterogeneity in susceptibility to infectious disease. However, the three-dimensional nature of antibody-epitope interactions makes the discovery of non-obvious targets challenging. We implemented a novel computational method and synthetic biology pipeline for identifying epitopes that are functionally important in the SARS-CoV-2 proteome and identified an IgM-dominant response to an exposed Membrane protein epitope which to our knowledge is the strongest correlate of severe disease identified to date (adjusted OR 72.14, 95% CI: 9.71 – 1300.15), stronger even than the exponential association of severe disease with age. We also identify persistence (> 2 years) of this IgM response in individuals with longCOVID, and a correlation with fatigue and depression symptom burden. The repetitive arrangement of this epitope and the pattern of isotype class switching is consistent with this being a previously unrecognized T independent antigen. These findings point to a coronavirus host-pathogen interaction characteristic of severe virus driven immune pathology. This epitope is a promising vaccine and therapeutic target as it is highly conserved through SARS-CoV-2 variant evolution in humans to date and in related coronaviruses (e.g. SARS-CoV), showing far less evolutionary plasticity than targets on the Spike protein. This provides a promising biomarker for longCOVID and a target to complement Spike-directed vaccination which could broaden humoral protection from severe or persistent disease or novel coronavirus spillovers
Progress report no. 3
Statement of responsibility on title-page reads: editors: M.J. Driscoll, D.D. Lanning, I. Kaplan; contributors: S. T. Brewer, G.J. Brown, P. Delaquil, M.J. Driscoll, G.A. Ducat, I.A. Forbes, M. V. Gregory, S.Y. Ho, M.S. Kalra, C.S. Kang, L.T. Kim, D.D. Lanning, J.L. Lazewatsky, T.C. Leung, E.A. Mason, N.R. Ortiz, N.C. Rasmussen, I.C. Rickard, K.D. Roberson, A.T. Supple, A.M. Thompson, and C.P. TzanosIncludes bibliographical referencesProgress report ; June 30, 1972U.S. Atomic Energy Commission contracts: AT(11-1)306
Progress report no. 2
Statement of responsibility on title-page reads: Editors: I.A. Forbes, M.J. Driscoll, N.C. Rasmussen, D.D. Lanning and I. Kaplan; Contributors: S.T. Brewer, G.J. Brown, P.DeLaquil, III, M.J. Driscoll, I.A. Forbes, C.W. Forsberg, E.P. Gyftopoulos, P.L. Hendrick, C.S. Kang, I. Kaplan, J.L. Klucar, D.D. Lanning, T.C. Leung, E.A. Mason, N.R. Ortiz, N.A. Passman, N.C. Rasmussen, I.C. Rickard, V.C. Rogers, G.E. Sullivan, A.T. Supple, and C. P. TzanosIncludes bibliographical referencesProgress report; June 30, 1971U.S. Atomic Energy Commission contract AT(11-1)306
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A Review of Interventions to Reduce Mechanical Restraint and Seclusion among Adult Psychiatric Inpatients
Objective: This review examines nature and effectiveness of interventions to reduce the use of mechanical restraint and seclusion among adult psychiatric inpatients.
Method: Electronic searches were conducted to locate post-1960 empirical studies of restraint and seclusion reduction in English. A total of 36 studies were identified, mostly from the USA. Analysis was conducted using a structured data extraction tool.
Results: The majority of studies reported reduced levels or mechanical restraint and/or seclusion, but the standard of evidence was poor. There were no randomised trials. Most were retrospective studies of official records before and after the intervention was introduced, with varying follow-up periods. The interventions were diverse, but tended to include one or more of the following: new restraint and/or seclusion policies, staffing changes, staff training, review procedures and crisis management initiatives. The research was unable to address which of these elements was most effective. There was also evidence that some improved outcomes were achieved by substituting restraint or seclusion for each other or for alternatives forms of containment (medication in particular). Nurses’ attitudes, skills and approach to patient care were absent from the literature.
Conclusions: Interventions probably can reduce the use of restraint and seclusion, but better designed research is required to demonstrate their effectiveness conclusively. More attention should also be paid to understanding how interventions work, particularly from the perspective of nursing staff. This is essential to the successful implementation of restraint and seclusion interventions across different psychiatric settings and treatment populations
The Druze: A Population Genetic Refugium of the Near East
BACKGROUND: Phylogenetic mitochondrial DNA haplogroups are highly partitioned across global geographic regions. A unique exception is the X haplogroup, which has a widespread global distribution without major regions of distinct localization. PRINCIPAL FINDINGS: We have examined mitochondrial DNA sequence variation together with Y-chromosome-based haplogroup structure among the Druze, a religious minority with a unique socio-demographic history residing in the Near East. We observed a striking overall pattern of heterogeneous parental origins, consistent with Druze oral tradition, together with both a high frequency and a high diversity of the mitochondrial DNA (mtDNA) X haplogroup within a confined regional subpopulation. Furthermore demographic modeling indicated low migration rates with nearby populations. CONCLUSIONS: These findings were enabled through the use of a paternal kindred based sampling approach, and suggest that the Galilee Druze represent a population isolate, and that the combination of a high frequency and diversity of the mtDNA X haplogroup signifies a phylogenetic refugium, providing a sample snapshot of the genetic landscape of the Near East prior to the modern age
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