To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
ABSTRACT IMPACT: Identifying factors associated with opioid overdoses will enable better resource allocation in communities most impacted by the overdose epidemic. OBJECTIVES/GOALS: Opioid overdoses often occur in hotspots identified by geographic and temporal trends. This study uses principles of community engaged research to identify neighborhood and community-level factors associated with opioid overdose within overdose hotspots which can be targets for novel intervention design. METHODS/STUDY POPULATION: We conducted an environmental scan in three overdose hotspots’‘ two in an urban center and one in a small city’‘ identified by the Rhode Island Department of Health as having the highest opioid overdose burden in Rhode Island. We engaged hotspot community stakeholders to identify neighborhood factors to map within each hotspot. Locations of addiction treatment, public transportation, harm reduction programs, public facilities (i.e., libraries, parks), first responders, and social services agencies were converted to latitude and longitude and mapped in ArcGIS. Using Esri Service Areas, we will evaluate the service areas of stationary services. We will overlay overdose events and use logistic regression identify neighborhood factors associated with overdose by comparing hotspot and non-hotspot neighborhoods. RESULTS/ANTICIPATED RESULTS: We anticipate that there will be differing neighborhood characteristics associated with overdose events in the densely populated urban area and those in the smaller city. The urban area hotspots will have overlapping social services, addiction treatment, and transportation service areas, while the small city will have fewer community resources without overlapping service areas and reduced public transportation access. We anticipate that overdoses will occur during times of the day when services are not available. Overall, overdose hotspots will be associated with increased census block level unemployment, homelessness, vacant housing, and low food security. DISCUSSION/SIGNIFICANCE OF FINDINGS: Identifying factors associated with opioid overdoses will enable better resource allocation in communities most impacted by the overdose epidemic. Study results will be used for novel intervention design to prevent opioid overdose deaths in communities with high burden of opioid overdose.
Nanocrystalline bulk silicon samples were fabricated using silicon nanoparticles from the gas phase, applying a spark-plasma sintering process. The mean diameter of the crystalline grains after sintering was 30 nm and smaller, the density above 97 % of that of crystalline silicon. Transmission electron microscopy showed a homogenous nanostructure. The thermal conductivity of such an n-type sample with a nominal doping level of 5×1020 cm-3 was around 11 Wm-1K-1 at room temperature. With Seebeck-coefficient α = -150 μV/K and specific conductivity σ = 290 S cm-1, the resulting efficiency ZT is approximately 0.02.
We prove convergence and quasi-optimal complexity of an adaptive finite element algorithm on triangular meshes with standard mesh refinement. Our algorithm is based on an adaptive marking strategy. In each iteration, a simple edge estimator is compared to an oscillation term and the marking of cells for refinement is done according to the dominant contribution only.
In addition, we introduce an adaptive stopping criterion for iterative solution which compares an estimator for the iteration error with the estimator for the discretization error.
Evidence and consensus on best practices on the management of human bite injuries is lacking. Our objective was to identify factors that are associated with delay to emergency department (ED) presentation, antibiotic usage and patient admission.
We present a retrospective chart review of adults treated for human bites. Multivariable logistic regression models used demographic characteristics and bite circumstances and characteristics as factors associated with ED presentation more than 24 hours after the bite, antibiotic usage and hospital admission.
Of the 388 patients evaluated for a human bite, 66.5% were bitten during an altercation; 23.8% presented more than 24 hours after the bite; 50.3% were bitten on the hands or fingers, 23.5% on an extremity and 17.8% on the head or neck. Only 7.7% of all patients sustained closed-fist injuries; the majority had occlusional or other kinds of bites. The majority of patients (77.3%) received antibiotics and 11.1% were admitted to hospital. Patients who had greater odds of presenting more than 24 hours after the bite were black (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.02–3.13), Hispanic (OR 2.68, 95% CI 1.22–5.89) and those who had a non-occupational bite (OR 3.87, 95% CI, 1.68–8.90). Patients had a greater chance of receiving antibiotics if they were bitten during an altercation (OR 1.87, 95% CI, 1.09–3.20) and were bitten on the hands or fingers (OR 2.23, 95% CI 1.31-3.80). Patients had a greater chance of being admitted to the hospital if they were bitten during an altercation (OR 4.91, 95% CI 1.65–14.64), bitten on the hands or fingers (OR 5.26, 95% CI, 1.74–15.87) and if they presented ≥ 24 hours after the bite.
Most patients presented to the ED within 24 hours of their injury and received antibiotics. The circumstances surrounding the bite appeared to be associated with delay to ED presentation, receipt of antibiotics and admission to the hospital. There are ethnic background differences in delay to ED presentation. ED clinicians in our study favour antibiotic usage and admission based on the body location of the bite, despite little evidence to support these practices.
The demography of healthcare workers (HCWs) and non- HCWs seeking medical care at emergency departments after a non-percutaneous potential exposure to human immunodeficiency virus (HIV) duringcardiopulmonary resuscitation (CPR), the types and body locations of their exposures, the time elapsed from exposure to emergency department presentation, and usage of HIV-post-exposure prophylaxis (PEP) for these exposures are described.
A retrospective study of emergency department patients who were exposed to blood or body fluids during CPR in Rhode Island from January 1995–June 2001 was performed.The demography, characteristics of the exposure, and HIV-PEP usage for these patients were compared, and the elapsed time from exposure to evaluation inthe emergency department was calculated.
Of the 39 patients exposed to non-percutaneous blood or body fluid during CPR, 22 were healthcareworkers (HCWs) and 17 were non-HCWs. Thirty-four patients sustained mucous membrane exposures. Most of the patients (69.2%) were exposed to saliva or sputum (p <0.001), experienced a mouth exposure (71.8%; p <0.0001) and presented to the emergency department within one day of their exposure (84.4%; p <0.0001).Three HCWs and no non-HCWs were offered HIV-PEP for their CPR exposure. Of the three HCWs offered PEP, two actually received it.
Nearly half of the patients who presented with non-percutaneous exposures acquired during CPR were not HCWs. Most of the exposures were to saliva or sputum and occurred on their mucous membranes. Continuing education programs on maintaining universal precautions to prevent blood or body fluid exposures and appreciating the benign nature of most non-percutaneous exposures possible during CPR are needed.
There are very few reference solutions in the literature on
non-Boussinesq natural convection flows. We propose here a test
case problem which extends the well-known De Vahl Davis
differentially heated square cavity problem to the case of large
temperature differences for which the Boussinesq approximation is
no longer valid. The paper is split in two parts: in this first
part, we propose as yet unpublished reference solutions for cases
characterized by a non-dimensional temperature difference of 0.6,
Ra = 106 (constant property and variable property cases) and
Ra = 107 (variable property case). These reference solutions were
produced after a first international workshop organized by CEA and
LIMSI in January 2000, in which the above authors volunteered to
produce accurate numerical solutions from which the present
reference solutions could be established.
In this note, we propose and analyse a method for handling
interfaces between non-matching grids based on an approach
suggested by Nitsche (1971) for the approximation of
Dirichlet boundary conditions. The exposition is limited to
self-adjoint elliptic problems, using Poisson's equation as a
model. A priori and a posteriori error estimates are given. Some
numerical results are included.
This article surveys a general approach to error control and adaptive mesh
design in Galerkin finite element methods that is based on duality principles
as used in optimal control. Most of the existing work on a posteriori error
analysis deals with error estimation in global norms like the ‘energy norm’
or the L2 norm, involving usually unknown ‘stability constants’. However, in
most applications, the error in a global norm does not provide useful bounds
for the errors in the quantities of real physical interest. Further, their sensitivity
to local error sources is not properly represented by global stability constants.
These deficiencies are overcome by employing duality techniques, as
is common in a priori error analysis of finite element methods, and replacing
the global stability constants by computationally obtained local sensitivity
factors. Combining this with Galerkin orthogonality, a posteriori estimates
can be derived directly for the error in the target quantity. In these estimates
local residuals of the computed solution are multiplied by weights which
measure the dependence of the error on the local residuals. Those, in turn,
can be controlled by locally refining or coarsening the computational mesh.
The weights are obtained by approximately solving a linear adjoint problem.
The resulting a posteriori error estimates provide the basis of a feedback process
for successively constructing economical meshes and corresponding error
bounds tailored to the particular goal of the computation. This approach,
called the ‘dual-weighted-residual method’, is introduced initially within an
abstract functional analytic setting, and is then developed in detail for several
model situations featuring the characteristic properties of elliptic, parabolic
and hyperbolic problems. After having discussed the basic properties
of duality-based adaptivity, we demonstrate the potential of this approach by
presenting a selection of results obtained for practical test cases. These include
problems from viscous fluid flow, chemically reactive flow, elasto-plasticity, radiative
transfer, and optimal control. Throughout the paper, open theoretical
and practical problems are stated together with references to the relevant literature.
Email your librarian or administrator to recommend adding this to your organisation's collection.