Pertussis in Massachusetts, 1981-1991: incidence, serologic diagnosis, and vaccine effectiveness

Massachusetts provides diphtheria-tetanus toxoid-pertussis (DTP) vaccine, and since 1980 has monitored pertussis with a statewide diagnostic service. The incidence of bacteriologically confirmed pertussis was 104.5 per 100,000 person-years in 1-month-old infants and declined progressively thereafter. Infants < 6 months old experienced disproportionate morbidity: 44% of bacteriologically confirmed pertussis, 64% of hospitalizations, and 71% of hospital days. Most children with pertussis had received < 3 DTP doses during childhood, whereas 87% of adolescents with pertussis had received > or = 4 doses. Serodiagnosis by single serum anti-pertussis toxin antibody ELISA increased the incidence of confirmed pertussis in persons 11-19 years old from 3.0 to 12.9 per 100,000 and in persons > or = 20 years old from 0.16 to 0.56 per 100,000. Bacteriologic methods underestimate pertussis incidence, but a single serum anti-pertussis toxin antibody ELISA is a practical method for population-based diagnosis in adolescents and adults.     

The effect of 9-beta-D-arabinofuranosyl-2-fluoroadenine and 1-beta-D-arabinofuranosylcytosine on the cell cycle phase distribution, topoisomerase II level, mitoxantrone cytotoxicity, and DNA strand break production in K562 human leukemia cells

The UvrA and UvrB proteins form part of the UvrABc endonuclease, which is responsible for nucleotide excision repair in Escherichia coli. Using a mobility shift gel assay we have studied the binding of UvrA dimer, UvrB monomer and UvA(2)B trimer complexes with 40, 50 and 136 bp (32)P-end-labelled DNA fragments adducted with aflatoxin B(1). UvrA was shown to re-associate with adduct specific UvrB: DNA complexes, a phenomenon which could be reversed by the addition of 500 mM potassium chloride or anti-UvrA anti-sera. Re-association was shown to be UvrA concentration dependent. Re-association of UvrA(2)B to the UvrB:DNA complex was not seen. We have also shown that the UvrB:DNA complex, in the case of aflatoxin B(1), is extremely stable with a half-life excess of 400 min and that fragment termini are not a specific substrate for UvrA binding.     

Electroform replication used for multiple x-ray mirror production

Work done to produce x-ray mirrors via electroform replication is reported. Several advances have been made over previous work. We have produced lower grazing incidence angle (30 min) mirrors, obtained quantitative measurements up to higher energies (6.40 keV), produced about four times as many replicas from one mandrel, and obtained angular resolutions better than other work done with replicated metal mirrors.     

Activation analyses updating the ITER radioactive waste assessment

A study is reported which computes the radiation transport and activation response throughout the ITER machine and updates the ITER radioactive waste assessment using modern 3D models and up-to-date methods. The latest information on component design, maintenance, replacement schedules and materials is adopted. The radwaste classification is revised for all the major components of ITER, as well as several representative port plugs. Results include categorisation snapshots at different decay times, time histories of radiological quantities throughout the machine, and guidelines on interim decay times for components. All plasma-facing materials except tungsten are found to classify as type B due to the transmutation of their main constituents. Major contributors to the IRAS index of all materials are reported. Elemental concentration limits for type A classification of first wall and divertor materials are obtained; for the steels, only a reduction in service lifetime can reduce the waste class. Comparison of total waste amounts with earlier assessments is limited by the fact that analyses of some components are still preliminary; the trend, however, indicates a potential reduction in the total amount of waste if component segregation is demonstrated.     

Effects of recent energy system changes on CO<Subscript>2</Subscript> projections for the United States

Recent projections of future US carbon dioxide (CO₂) emissions are considerably lower than projections made just a decade ago. A myriad of factors have contributed to lower forecasts, including reductions in end-use energy service demands, improvements in energy efficiency, and technological innovations. Policies that have encouraged these changes include renewable portfolio standards, corporate vehicle efficiency standards, smart growth initiatives, revisions to building codes, and air and climate regulations. Understanding the effects of these and other factors can be advantageous as society evaluates opportunities for achieving additional CO₂ reductions. Energy system models provide a means to develop such insights. In this analysis, the MARKet ALlocation (MARKAL) model was applied to estimate the relative effects of various energy system changes that have happened since the year 2005 on CO₂ projections for the year 2025. The results indicate that transformations in the transportation and buildings sectors have played major roles in lowering projections. Particularly influential changes include improved vehicle efficiencies, reductions in projected travel demand, reductions in miscellaneous commercial electricity loads, and higher efficiency lighting. Electric sector changes have also contributed significantly to the lowered forecasts, driven by demand reductions, renewable portfolio standards, and air quality regulations.     

The impact of nuclear analysis on ITER design and licensing

The complexity of nuclear analysis on the design components of ITER is discussed. These analyses include the determination of several nuclear responses and it is shown that these results are not only relevant to the component under examination but have implications for the design of many other, often remote, systems. The contribution of nuclear analysis to the licensing process is discussed. An example is given of how this complexity means that the there is a large set of complementary analyses required to address the concerns of the licensing authorities. It also means that the nuclear analysis must be co-ordinated to ensure that the results are self-consistent and provide an integrated solution.     

An Integrated Assessment of the Impacts of Hydrogen Economy on Transportation, Energy Use, and Air Emissions

This paper presents an analysis of the potential system-wide energy and air emissions implications of hydrogen fuel cell vehicle (H ₂-FCV) penetration into the U.S. light duty vehicle (LDV) fleet. The analysis uses the U.S. EPA MARKet ALlocation (MARKAL) technology database and model to simultaneously consider competition among alternative technologies and fuels, with a focus on the transportation and the electric sectors. Our modeled reference case suggests that economics alone would not yield H₂-FCV penetration by 2030. A parametric sensitivity analysis shows that H₂-FCV can become economically viable through reductions in H ₂-FCV costs, increases in the costs of competing vehicle technologies, and increases in oil prices. Alternative scenarios leading to H₂-FCV penetration are shown to result in very different patterns of total system energy usage depending on the conditions driving H₂-FCV penetration. Overall, the model suggests that total CO₂ emissions changes are complex, but that CO₂ emission levels tend to decrease slightly with H₂-FCV penetration. While carbon capture and sequestration technologies with H ₂ production and renewable technologies for H₂ production have the potential to achieve greater CO₂ reductions, these technologies are not economically competitive within our modeling time frame without additional drivers     

Surface characterization of human hair by atomic force microscopy in the imaging and F-d modes

Surface structure and surface mechanical properties of human hair have been characterized by atomic force microscopy in the imaging mode and by force vs. distance, F-d, analysis. The effects of treatment by commercial conditioner/shampoo or by aqueous exposure have been investigated. The cuticular structure has been imaged at medium resolution; longitudinal striations with lateral spacings of 150-350 nm and vertical corrugations in the range 2-8 nm were observed at higher resolution. The features are similar to those observed for untreated wool fibre. Both adventitious debris/contamination and residues from cosmetic treatment can be imaged with resolution in the low-nanometre range. Removal of the cuticular surface layer from treatment with alkali solution, and subsequent imaging, revealed a fibrous substructure. F-d analysis of the surface is a rich source of spatially resolved mechanical and chemical information. Surface stiffness, and an equivalent Young's Modulus, E, can be inferred from the shape of the 'approach' tip-to-surface contact curve. A value of E of approximately 10 MPa was obtained for untreated hair. During aqueous exposure for 1 h the stiffness and modulus decreased by approximately a factor of 10. The discontinuity seen at 'lift-off' during the retract half-cycle of F-d analysis represents a measure of tip-to-surface adhesion. Adhesion decreased during aqueous exposure and was below the level of detectability after 1 h. Likewise, treatment by conditioner had the effect of lowering adhesion. High resolution F-d data revealed features that are consistent with the presence of a thin and readily compressible surface layer, probably analogous to the surface lipid layer on untreated wool fibre.     

Multiple window time-varying spectral analysis

A multiwindow method for generating a time-varying spectrum of nonstationary signals is presented The time-varying spectrum is computed from an optimally weighted average of multiple orthogonal windowed spectrograms. The weights are determined using linear least squares estimation with respect to a reference time-frequency distribution. Examples are provided, with performance criteria measures, to demonstrate and quantify the effectiveness of the method