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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.
To investigate an outbreak of Burkholderia cepacia complex and describe the measures that revealed the source.
A 629-bed, tertiary-care, pediatric hospital in Houston, Texas.
Pediatric patients without cystic fibrosis (CF) hospitalized in the pediatric and cardiovascular intensive care units.
We investigated an outbreak of B. cepacia complex from February through July 2016. Isolates were evaluated for molecular relatedness with repetitive extragenic palindromic polymerase chain reaction (rep-PCR); specific species identification and genotyping were performed at an independent laboratory. The investigation included a detailed review of all cases, direct observation of clinical practices, and respiratory surveillance cultures. Environmental and product cultures were performed at an accredited reference environmental microbiology laboratory.
Overall, 18 respiratory tract cultures, 5 blood cultures, 4 urine cultures, and 3 stool cultures were positive in 24 patients. Among the 24 patients, 17 had symptomatic infections and 7 were colonized. The median age of the patients was 22.5 months (range, 2–148 months). Rep-PCR typing showed that 21 of 24 cases represented the same strain, which was identified as a novel species within the B. cepacia complex. Product cultures of liquid docusate were positive with an identical strain of B. cepacia complex. Local and state health departments, as well as the CDC and FDA, were notified, prompting a multistate investigation.
Our investigation revealed an outbreak of a unique strain of B. cepacia complex isolated in clinical specimens from non-CF pediatric patients and from liquid docusate. This resulted in a national alert and voluntary recall by the manufacturer.
Medically unexplained symptoms (MUS) are not only common and distressing, but are also typically poorly managed in general medical settings. Those suffering from these problems tend to incur significantly higher health costs than the general population. There are many effective treatments for different MUS; these are almost entirely based on cognitive-behavioural approaches. However, the wide range of treatment protocols tend to be ‘syndrome specific’. As such, they do not generalise well in terms of training and application, making them expensive and difficult to disseminate, suggesting the desirability of developing a transdiagnostic approach. The general basis of such a CBT grounded transdiagnostic approach is considered, and the particular need to incorporate cognitive elements of both anxiety or health anxiety (threat) and depression (loss) is highlighted. Key empirically grounded and evidence-based processes (both specific and general) previously identified as underpinning the maintenance of MUS are delineated. The way in which these can be combined in a transdiagnostic model that accounts for most MUS presentations is presented and linked to a formulation-driven transdiagnostic treatment strategy, which is described. However, the need to take more syndrome-specific issues into account in treatment is identified, suggesting that the optimum treatment may be a hybrid transdiagnostic/specific approach with formulation, shared understanding, belief change strategies, and behavioural experiments at its heart. The generalisation of such approaches to psychological problems occurring in the context of ‘long-term conditions’ is identified as a further important development that is now within reach.
Variation in human cognitive ability is of consequence to a large number of health and social outcomes and is substantially heritable. Genetic linkage, genome-wide association, and copy number variant studies have investigated the contribution of genetic variation to individual differences in normal cognitive ability, but little research has considered the role of rare genetic variants. Exome sequencing studies have already met with success in discovering novel trait-gene associations for other complex traits. Here, we use exome sequencing to investigate the effects of rare variants on general cognitive ability. Unrelated Scottish individuals were selected for high scores on a general component of intelligence (g). The frequency of rare genetic variants (in n = 146) was compared with those from Scottish controls (total n = 486) who scored in the lower to middle range of the g distribution or on a proxy measure of g. Biological pathway analysis highlighted enrichment of the mitochondrial inner membrane component and apical part of cell gene ontology terms. Global burden analysis showed a greater total number of rare variants carried by high g cases versus controls, which is inconsistent with a mutation load hypothesis whereby mutations negatively affect g. The general finding of greater non-synonymous (vs. synonymous) variant effects is in line with evolutionary hypotheses for g. Given that this first sequencing study of high g was small, promising results were found, suggesting that the study of rare variants in larger samples would be worthwhile.
The future of centimetre and metre-wave astronomy lies with the Square Kilometre Array (SKA), a telescope under development by a consortium of 17 countries that will be 50 times more sensitive than any existing radio facility. Most of the key science for the SKA will be addressed through large-area imaging of the Universe at frequencies from a few hundred MHz to a few GHz. The Australian SKA Pathfinder (ASKAP) is a technology demonstrator aimed in the mid-frequency range, and achieves instantaneous wide-area imaging through the development and deployment of phased-array feed systems on parabolic reflectors. The large field-of-view makes ASKAP an unprecedented synoptic telescope that will make substantial advances in SKA key science. ASKAP will be located at the Murchison Radio Observatory in inland Western Australia, one of the most radio-quiet locations on the Earth and one of two sites selected by the international community as a potential location for the SKA. In this paper, we outline an ambitious science program for ASKAP, examining key science such as understanding the evolution, formation and population of galaxies including our own, understanding the magnetic Universe, revealing the transient radio sky and searching for gravitational waves.
Significant research effort is regularly applied to the goal of reducing the size of radio-frequency antennas while maintaining the entire set of positive attributes of proven but relatively large antennas. Such parameters as frequency response (multiple or single), bandwidth, and complexity of the antenna-driver balun structures require iterative optimization. The direct-write processes now available have enabled the insertion of reactive-loading elements as integral parts of the antenna structure, especially into new conformal designs. These reactive-loading elements were used in conjunction with modern design techniques to achieve antenna devices that were reduced in size to as much as half that of traditional counterparts. The performances of the miniaturized antennas constructed by direct-write methods were evaluated and compared to those of traditional antenna structures.
Against a backdrop of the latest ITRS predictions for CMOS junctions, we compare methods for dopant introduction and activation, methods for making contact to these regions, and methods for measurement of material and device properties. As activation without diffusion (sub-melt laser, capacitor discharge flash, or solid phase epitaxy) becomes more feasible, the burden on Xj, Rsh and abruptness falls on the implanters, and the process margin appears slim, opening the door for other methods of doping. For contact resistance, a major component of transistor parasitics, we find that either a move to a different substrate, or from a single midgap silicide to two band-edge metals/silicides can be quite beneficial. Through the use of simple test structures, we describe a means of extracting each component of the parasitic resistance, facilitating development of materials for CMOS junctions.
Irradiation of thin films and solar cells with 1.00 MeV protons has been investigated for a fluence of 5.0E14 cm−2. We have used photothermal deflection spectroscopy and light conductivity to characterize the effect of irradiation on thin films; current-voltage and quantum efficiency measurements have been used to determine the effects of irradiation on solar cells.
Irradiation introduces increases in the sub-band-gap optical absorption and decreases in the photoconductivity of thin films. The major effect on solar cells is to reduce the short-circuit current. The spectral dependence of the quantum efficiency is reduced in a somewhat uniform manner with irradiation and also recovers in a uniform manner with annealing. Investigations of the annealing behavior of both thin films and solar cells show similar behaviors in the measured properties. The properties of both the films and cells are essentially restored with a one-hour anneal at 200 °C. Attempts have been made to use simple models to calculate defect densities and carrier transport.
Preliminary results are presented for a new approach proposed by the present investigators to solve the problem of light-induced degradation in amorphous silicon semiconductors. The approach uses low-temperature metal-organic chemical vapor deposition (LTMOCVD) of tailored organometallic precursors. The precursors employed are non-toxic, non-hazardous and easy to handle. In the present paper, a-Si:H films were grown, using argon with various hydrogen concentrations as carrier gas, in a cold-wall CVD reactor at a reactor pressure of 1-10 torr and substrate temperature in the range 300–450°C. Characterization studies were performed using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and extended electron-energy-loss fine structure spectroscopy (EXELFS). The results of these studies showed that the films were uniform, continuous, adherent and highly pure--contaminant levels were below the detection limits of XPS. In addition, EXELFS results showed that short-range order (SRO), consisting of the same tetrahedral coordinated units found in crystalline silicon, does exist in all the amorphous samples, regardless of hydrogen concentration. However, the degree of stuctural disorder in the silicon local tetrahedral units decreased as hydrogen was added.
We present a study of depletion width effects on the photocarrier collection efficiency in reactive magnetron sputtered a-Si:H films. Results are presented for as-deposited and light soaked 1.75 eV optical gap samples, and an as-deposited 1.60 eV gap film. The depletion width behavior with reverse bias is inferred from capacitance measurements. Comparison with photocurrent collection versus reverse bias voltage suggests that space charge effects can have an important role in the interpretation of collection efficiency on Schottky barriers.
a-Si:H solar cells were irradiated with 1.00 MeV proton fluences in the range of 1.00E14 to 1.2 5E15 cm-2. Annealing of the short-circuit current density was studied at 0, 22, 50, 100 and 150 °C. Annealing times ranged from an hour to several days. The measurements confirmed that annealing occurs at O °C and the initial characteristics of the cells are restored by annealing at 200 °C. It is proposed that the degradation in the short-circuit current density with irradiation is due to carrier recombination through the fraction of D° states bounded by the guasi-Fermi energies. The time dependence of the rate of annealing in the short-circuit current density appears to be consistent with the interpretation that there is dispersive transport mechanism which leads to the annealing of the irradiation induced defects.
High quality metallic and metallic-glass microballoons (MMB and MGMB) are of considerable interest for fusion target applications on account of the intrinsic properties of these materials such as high density, high strength and high atomic number. We report the first successfully formed submillimeter and millimeter spherical shells of tin and of a gold-lead-antimony alloy by means of the hollow-jet instability technique developed by one of us (JMK). Examination of tin specimens by means of SEM has revealed that surface quality varied from poor to excellent. Whereas this metal has been employed only as a convenient and inexpensive material, the gold alloy is important because it is hard, has high atomic number, and may be solidified into the amorphous state through the provision of a modest cooling rate. We have produced AuPbSb spherules up to 1.5 mm in diameter using LN2 or chilled methanol as a coolant, and have found that these amorphous samples possess a superb surface smoothness compatible with fusion target requirements. Hollow spheres currently made of this alloy have an average O.D. of 2000 μm.
During the past few years we have been studying several of the physical processes relevant to the production of spherical shells for inertial confinement fusion targets, both in a microgravity environment and in a containerless environment. The work has led to the development of several experimental facilities. Those which are most unique are described here, and fall into three categories as follows: 1. Ones which provide an induced low- or microgravity containerless environment, such as a vertical drag-free wind tunnel, two differing low-pressure and/or high-temperature drop towers for processing metallic or metallic-glass specimens, and a neutral buoyancy tank, 2. Ones providing containerless processing capability, such as a focusing radiator and an electrostatic levitator and 3. Ones providing extended microgravity and containerless capabilities, such as the KC-135 aircraft and the Space Processing Application Rockets. The physical processes which we have been studying include, but are not limited to, those which establish the shell sphericity, concentricity, surface topology, material properties, coatings, heating and cooling requirements and the effects of gravity on fusion pellet fabrication processes.
This paper describes four key measurements of critical coating performance attributes which can affect coated optical fiber performance. The four measurement methods to be described are: 1) primary coating adhesion, 2) coating toughness, 3) primary coating equilibrium modulus, and 4) primary coating glass transition temperature.
Mercuric iodide (HgI2) is a semiconductor that has shown great promise for use in roomtemperature high-resolution x-ray and gamma-ray spectrometers. Its widespread usage has been limited, however, by low yield and long-term reliability problems. The processing of this material is still in its infancy compared to silicon, so research efforts continue to pursue the root causes of device failures. Two likely sources of performance limitations are impurities and poor contacts. Significant efforts have been expended in developing and using various purification schemes. However, quantitative chemical analyses have shown that several metallic impurities still exist at the high ppb level. In addition, it has not yet been definitively determined which impurities are most problematic and at what level they have a detrimental effect. Leakage currents and currentvoltage measurements have been used to study the movement of mobile impurity-related defect centers in the bulk mercuric iodide. In particular, this method has been used to quantify the drift of metallic impurities, such as Ag and Cu, which are known to or believed to degrade HgI2 detectors. Four-point-probe sheet resistance measurements have been used to study the stability of contacts and the formation of reaction layers. In particular, such measurements have revealed that the Pd contacts currently used for the highest quality detectors are not as stable as previously thought, as the films of Pd react with the HgI2 to form the amalgam PdHg.