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A national need is to prepare for and respond to accidental or intentional disasters categorized as chemical, biological, radiological, nuclear, or explosive (CBRNE). These incidents require specific subject-matter expertise, yet have commonalities. We identify 7 core elements comprising CBRNE science that require integration for effective preparedness planning and public health and medical response and recovery. These core elements are (1) basic and clinical sciences, (2) modeling and systems management, (3) planning, (4) response and incident management, (5) recovery and resilience, (6) lessons learned, and (7) continuous improvement. A key feature is the ability of relevant subject matter experts to integrate information into response operations. We propose the CBRNE medical operations science support expert as a professional who (1) understands that CBRNE incidents require an integrated systems approach, (2) understands the key functions and contributions of CBRNE science practitioners, (3) helps direct strategic and tactical CBRNE planning and responses through first-hand experience, and (4) provides advice to senior decision-makers managing response activities. Recognition of both CBRNE science as a distinct competency and the establishment of the CBRNE medical operations science support expert informs the public of the enormous progress made, broadcasts opportunities for new talent, and enhances the sophistication and analytic expertise of senior managers planning for and responding to CBRNE incidents.
A numerical nanoindentation model was developed using the Material Point Method (MPM), which was chosen because it can handle both large deformations and dynamic contact under the indenter. Because of the importance of contact, prior MPM contact methods were enhanced to improve their accuracy for contact detection. Axisymmetric and full 3D simulations investigated the effects of hardening, strain-rate dependent yield properties, and local structure under the indenter. Convergence of load–displacement curves required small cells under the indenter. To reduce computation time, we used an effective nonregular grid, called a tartan grid and describe its implementation. Tartan grids reduced simulation times by an order of magnitude. A series of simulated load–displacement curves were analyzed as “virtual experiments” by standard Oliver–Pharr methods to extract effective modulus and hardness of the indented material. We found that standard analysis methods give results that are affected by hardening parameters and strain-rate dependence of plasticity. Because these parameters are not known during experiments, extracted properties will always have limited accuracy. We describe an approach for extracting more properties and more accurate properties by combining MPM simulations with inverse methods to fit simulation results to entire load–displacement curves.
Recent studies have highlighted the threat that climate change poses to species, as areas of climatic suitability contract or shift across the landscape. North American Neotropical long-distant migrant bird species present a unique problem compared to sedentary species because climate change may differ significantly across their breeding and wintering grounds. Studying the potential future distributions of these birds is challenging on many levels, including the fact that our understanding of the wintering grounds of these species is quite poor. To address this issue, we analyse available eBird data during the winter season in the Western Hemisphere in an effort to further promote and direct citizen science efforts to focus on areas that are climatically undersampled. We used Mobility-Oriented Parity (MOP) to understand the areas where climates are most dissimilar from climates sampled by existing eBird checklists, creating a map that ranks the western hemisphere at a 10 km resolution for climatic sampling during the winter season. We found that parts of Mexico and Central America, areas of Colombia, almost the entire Amazon Basin, coastal Peru and Chile, and northern Argentina are climatically undersampled. As a test case, we then used the map of survey priorities to simulate additional sampling in Colombia and recalculated the rankings. Guiding additional sampling with the priorities reduced climate dissimilarities between sampled and unsampled grid cells more than when additional sampling expanded in proportion to current sampling efforts or based on geographic undersampling. Analyses of sampling coverage in environmental space, such as this, will be a useful tool for targeting monitoring effort for bird species.
Windpumping has been identified as a process that could potentially enhance sublimation of surface snow at high forcing frequency and spawn air movement deeper in firn at lower frequencies. We performed an experiment to examine the relationship between high-frequency wind and pressure measurements within the top meter of an alpine snowpack and compared experimental results with two theoretical predictions. We find that both theoretical predictions underestimate high-frequency perturbation pressure attenuation with depth in the near-surface snowpack and the discrepancy between theory and measurement increases with perturbation pressure frequency. The impact of this result for near-surface snow is that potential enhanced sublimation will occur over a shallower snow depth than these two theories predict. Correspondingly, interstitial air mixing at depth in firn will be driven by lower frequencies than these two theories predict. While direct measurement of these energy-rich lower frequencies is beyond the scope of this paper, stationary pressure measurements validate the presence of a pressure field that could drive near-surface circulation.
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ14CO2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ14CO2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participated in at least 1 round of the intercomparison, which has so far included 3 rounds of air distribution between 2007 and 2010. The comparison is intended to be ongoing, so that: a) the community obtains a regular assessment of differences between laboratories; and b) individual laboratories can begin to assess the long-term repeatability of their measurements of the same source air. Air used in the intercomparison was compressed into 2 high-pressure cylinders in 2005 and 2006 at Niwot Ridge, Colorado (USA), with one of the tanks “spiked” with fossil CO2, so that the 2 tanks span the range of Δ14CO2 typically encountered when measuring air from both remote background locations and polluted urban ones. Three groups show interlaboratory comparability within l% for ambient level Δ14CO2. For high CO2/low Δ14CO2 air, 4 laboratories showed comparability within 2%. This approaches the goals set out by the World Meteorological Organization (WMO) CO2 Measurements Experts Group in 2005. One important observation is that single-sample precisions typically reported by the AMS community cannot always explain the observed differences within and between laboratories. This emphasizes the need to use long-term repeatability as a metric for measurement precision, especially in the context of long-term atmospheric monitoring.
The radiocarbon content of whole air provides a theoretically ideal and now observationally proven tracer for recently added fossil-fuel-derived CO2 in the atmosphere (Cff). Over large industrialized land areas, determination of Cff also constrains the change in CO2 due to uptake and release by the terrestrial biosphere. Here, we review the development of a Δ14CO2 measurement program and its implementation within the US portion of the NOAA Global Monitoring Division's air sampling network. The Δ14CO2 measurement repeatability is evaluated based on surveillance cylinders of whole air and equates to a Cff detection limit of <0.9 ppm from measurement uncertainties alone. We also attempt to quantify additional sources of uncertainty arising from non-fossil terms in the atmospheric 14CO2 budget and from uncertainties in the composition of “background” air against which Cff enhancements occur. As an example of how we apply the measurements, we present estimates of the boundary layer enhancements of Cff and Cbio using observations obtained from vertical airborne sampling profiles off of the northeastern US. We also present an updated time series of measurements from NOAA GMD's Niwot Ridge site at 3475 m asl in Colorado in order to characterize recent Δ14CO2 variability in the well-mixed free troposphere.
This study identified factors that influenced physical activity (PA) participation among older adults from rural settings in Nova Scotia Canada and explored how the rural context may influence PA participation and promotion. Data were collected via individual semistructured interviews with 20 older adults (Mage = 77.5 years) from rural areas of Cape Breton and subjected to thematic analysis procedures (Braun & Clarke, 2006). Four themes representing factors that influence the prioritization of PA were identified: (1) historical context of activity, work, and productivity; (2) already busy with day-to-day activities; (3) being/staying on the go; and (4) cautionary approach. These findings suggest that PA promotion should be contextually salient, and highlight the need for a shared understanding between rural older adults and PA promoters regarding what constitutes being “physically active”. Effective promotion of PA among rural older adults may require a shift away from contemporary methods of PA promotion.
This study examined the psychometric properties of the DSM-oriented scales of the Child Behavior Checklist (Achenbach, Dumenci, & Rescorla, 2003) using confirmatory factor analysis to compare the six-factor structure of the DSM-oriented scales to competing models consistent with developmental theories of symptom differentiation. We tested these models on both clinic-referred (N = 757) and school-based, nonreferred (N = 713) samples of youths in order to assess the generalizability of the factorial structures. Although previous research has supported the fit of the six-factor DSM-oriented structure in a normative sample of youths ages 7 to 18 (Achenbach & Rescorla, 2001), tripartite model research indicates that anxiety and depressive symptomology are less differentiated among children compared to adolescents (Jacques & Mash, 2004). We thus examined the relative fit of a six- and a five-factor model (collapsing anxiety and depression) with younger (ages 7–10) and older (ages 11–18) youth subsamples. The results revealed that the six-factor model fit the best in all samples except among younger nonclinical children. The results extended the generalizability of the rationally derived six-factor structure of the DSM-oriented scales to clinic-referred youths and provided further support to the notion that younger children in nonclinical samples exhibit less differentiated symptoms of anxiety and depression.
Climate change during the so-called Little Ice Age (LIA) of the 15th to 19th centuries was once thought to be limited to the high northern latitudes, but increasing evidence reflects significant climate change in the tropics. One of the hypothesized features of LIA climate in the low latitudes is a more southerly mean annual position of the Intertropical Convergence Zone (ITCZ), which produced more arid conditions through much of the northern tropics. High-resolution stable oxygen isotope data and other sedimentary evidence from Laguna de Felipe, located on the Caribbean slope of the Cordillera Central of the Dominican Republic, support the hypothesis that the mean annual position of the ITCZ was displaced significantly southward during much of the LIA. Placed within the context of regional paleoclimate and paleoceanographic records, and reconstructions of global LIA climate, this shift in mean annual ITCZ position appears to have been induced by lower solar insolation and internal dynamical responses of the global climate system. Our results from Hispaniola further emphasize the global nature of LIA climate change and the sensitivity of circum-Caribbean climate conditions to what are hypothesized to be relatively small variations in global energy budgets.
The purpose of this article is to set the context for this special issue of Disaster Medicine and Public Health Preparedness on the allocation of scarce resources in an improvised nuclear device incident. A nuclear detonation occurs when a sufficient amount of fissile material is brought suddenly together to reach critical mass and cause an explosion. Although the chance of a nuclear detonation is thought to be small, the consequences are potentially catastrophic, so planning for an effective medical response is necessary, albeit complex. A substantial nuclear detonation will result in physical effects and a great number of casualties that will require an organized medical response to save lives. With this type of incident, the demand for resources to treat casualties will far exceed what is available. To meet the goal of providing medical care (including symptomatic/palliative care) with fairness as the underlying ethical principle, planning for allocation of scarce resources among all involved sectors needs to be integrated and practiced. With thoughtful and realistic planning, the medical response in the chaotic environment may be made more effective and efficient for both victims and medical responders.
(Disaster Med Public Health Preparedness. 2011;5:S20-S31)
Cholestyramine, the first bile acid sequestrant to be marketed, has been in use for over 20 years. Despite its low potency, requiring 16-24 g of polymer to achieve 20% LDL cholesterol reduction in hypercholesterolemic individuals, only one other sequestrant, colestipol, has come to market in the ensuing period. GelTex Pharmaceuticals has been involved for over six years in the discovery and development of new, more potent polymeric sequestrants. Two binding mechanisms are presented — one that operates via an aggregate binding structure and one that is effective via a defined site binding structure. These two binding mechanisms are compared and contrasted through bile acid binding isotherms. The best of these new sequestrants bind bile acids through a combination of hydrophobicity and ion exchange. Optimization and balancing of each of these interactions led us to more potent materials. The first of these, colesevelam hydrochloride is expected to be three to four times more potent than cholestyramine. A third generation product is still in research at GelTex. With another twofold increase in potency possible, single tablet therapy may become a reality.
AC Coupled Interconnection (ACCI), in conjunction with buried solder bump technology, provides a method to achieve signal I/O pitches of less than 75 μm and signaling rates greater than 5 Gbps per I/O on integrated circuits, while preserving excellent signal integrity. This paper presents a summary of approaches, status, and discusses material issues important to performance.
Metal patterned lines on a substrate have been annealed and broken down into isolated linear arrays of alloyed metal nanoscale droplets. These droplets are selectively fabricated across large-scale areas by controlling the location metal is present on a substrate. The metal instability and formation into nanoscale particles forms similar to studies in Rayleigh Instability of metal at an elevated temperature. Experimental results discussed here show a change in droplet diameter and formation by controlling the metal width.
Characterization of molecular scale electronic devices generally involves deposition of a metal top electrode onto an organic film. During the evaporation process, high energetic granules of metals may lead to unwanted reactions between the organic molecules and deposited top electrodes. This can cause, as commonly reported, lasting damage which leaves most junctions either short or open. To overcome this important issue of physical damage to the molecules, we developed a novel technique of interfacing molecules by laying prefabricated metallic electrodes on top of a monolayer of molecules. For the bottom electrode a monolayer of cadmium stearate ((C17H35COO)2Cd) was deposited, using the Langmuir-Blodgett technique, onto platinum (Pt) electrodes which further rested on 200nm of oxide used for isolation. A separate set of Aluminum (Al) electrodes were fabricated on a different oxide free, highly doped substrate and was gently placed on the cadmium stearate monolayer in room ambient. Conduction to the top electrode was accomplished by probing the backside of the highly doped wafer whereas the bottom electrodes were individually addressed. Pressure was applied to ensure firm contact between the molecules and the top electrodes. Preliminary results showed an observed switching voltage of 3.5V. Most of the devices with Al as the top electrodes exhibited a gradual progression from switching on the positive side, closing, and then switching towards the negative side.