Multi-layer light-weight protective coating and method for application

A thin, light-weight, multi-layer coating is provided for protecting metals and their alloys from environmental attack at high temperatures. A reaction barrier is applied to the metal substrate and a diffusion barrier is then applied to the reaction barrier. A sealant layer may also be applied to the diffusion barrier if desired. The reaction barrier is either non-reactive or passivating with respect to the metal substrate and the diffusion barrier. The diffusion barrier is either non-reactive or passivating with respect to the reaction barrier and the sealant layer. The sealant layer is immiscible with the diffusion barrier and has a softening point below the expected use temperature of the metal

An X-Ray Spectroscopic Study of the SMC X-1/Sk 160 System

We have investigated the composition and distribution of the wind of Sk 160, the supergiant companion of the X-ray star SMC X-1, by comparing an X-ray spectrum of the source, obtained with the ASCA observatory, during an eclipse with the computed spectra of reprocessed radiation from circumstellar matter with various density distributions. We show that the metal abundance in the wind of Sk 160 is no greater than a few tenths of solar, as has been determined for other objects in the Magellanic Clouds. We also show that the observed X-ray spectrum is not consistent with the density distributions of circumstellar matter of the spherically symmetric form derived for line-driven winds, nor with the density distribution derived from a hydrodynamic simulation of the X-ray perturbed and line-driven wind by Blondin & Woo (1995).Comment: 35 pages including 16 figures, uses AASTeX v5.0.2, accepted to Ap

Performance Characteristics of Putative Tests for Subclinical Chorioamnionitis

Objective: To evaluate amniotic fluid glucose, matrix metalloproteinase (MMP)-9, interleukin (IL)-6, and IL-12 for diagnosing subclinical chorioamnionitis in women with preterm labor. Methods: Forty-four women in preterm labor at 22–35 weeks gestation with suspected subclinical chorioamnionitis underwentamniocentesis.Amniotic fluid analysis included Gram stain, culture, and determination of glucose, MMP-9, IL-6, and IL-12 concentrations. Median values of these analytes were compared using the Mann-Whitney U test. Sensitivity, specificity, and positive and negative predictive values were calculated for tests using a positive amniotic fluid culture or delivery within 24 hours as the key outcome variables Results: Amniotic fluid concentrations of glucose, MMP-9, and IL-6 correlated closely with positive culture or delivery within 24 hours. IL-12 concentrations did not correlate with either a positive culture or delivery within 24 hours. Conclusions: Amniotic fluid glucose, MMP-9, and IL-6 reliably predict microbial invasion of the amniotic cavity or imminent delivery. IL-12 values did not correlate with amniotic fluid culture results or imminent delivery

Why Do HIV-1 and HIV-2 Use Different Pathways to Develop AZT Resistance?

The human immunodeficiency virus type 1 (HIV-1) develops resistance to all available drugs, including the nucleoside analog reverse transcriptase inhibitors (NRTIs) such as AZT. ATP-mediated excision underlies the most common form of HIV-1 resistance to AZT. However, clinical data suggest that when HIV-2 is challenged with AZT, it usually accumulates resistance mutations that cause AZT resistance by reduced incorporation of AZTTP rather than selective excision of AZTMP. We compared the properties of HIV-1 and HIV-2 reverse transcriptase (RT) in vitro. Although both RTs have similar levels of polymerase activity, HIV-1 RT more readily incorporates, and is more susceptible to, inhibition by AZTTP than is HIV-2 RT. Differences in the region around the polymerase active site could explain why HIV-2 RT incorporates AZTTP less efficiently than HIV-1 RT. HIV-1 RT is markedly more efficient at carrying out the excision reaction with ATP as the pyrophosphate donor than is HIV-2 RT. This suggests that HIV-1 RT has a better nascent ATP binding site than HIV-2 RT, making it easier for HIV-1 RT to develop a more effective ATP binding site by mutation. A comparison of HIV-1 and HIV-2 RT shows that there are numerous differences in the putative ATP binding sites that could explain why HIV-1 RT binds ATP more effectively. HIV-1 RT incorporates AZTTP more efficiently than does HIV-2 RT. However, HIV-1 RT is more efficient at ATP-mediated excision of AZTMP than is HIV-2 RT. Mutations in HIV-1 RT conferring AZT resistance tend to increase the efficiency of the ATP-mediated excision pathway, while mutations in HIV-2 RT conferring AZT resistance tend to increase the level of AZTTP exclusion from the polymerase active site. Thus, each RT usually chooses the pathway best suited to extend the properties of the respective wild-type enzymes

Closing the gap in Australian Aboriginal infant immunisation rates - the development and review of a pre-call strategy

Background: Improving timely immunisation is key to closing the inequitable gap in immunisation rates between Aboriginal children and non-Indigenous children. Aboriginal Immunisation Officers were employed in Hunter New England Local Health District (HNELHD), New South Wales (NSW), Australia, to telephone the families of all Aboriginal infants prior to the due date for their first scheduled vaccination. Methods: Aboriginal Immunisation Officers contacted the families of Aboriginal children born in the Hunter New England Local Health District (HNELHD) by telephone before their due immunisation date (pre-call) to provide the rationale for timely immunisation, and to facilitate contact with culturally safe local immunisation services if this was required. The impact of this strategy on immunisation coverage rates is reviewed. Results: For the period March 2010 to September 2014 there was a significant increase in immunisation coverage rate for Aboriginal children at 12 months of age in HNELHD (p < 0.0001). The coverage in the rest of NSW Aboriginal children also increased but not significantly (p = 0.218). Over the full study period there was a significant decrease in the immunisation coverage gap between Aboriginal children and non-Indigenous children in HNELHD (p < 0.0001) and the rest of NSW (p = 0.004). The immunisation coverage gap between Aboriginal and non-Indigenous infants decreased at a significantly faster rate in HNELHD than the rest of NSW (p = 0.0001). By the end of the study period in 2014, immunisation coverage in HNELHD Aboriginal infants had surpassed that of non-Indigenous infants by 0.8 %. Conclusions: The employment of Aboriginal immunisation officers may be associated with closing of the gap between Aboriginal and non-Indigenous infants' immunisation coverage in HNELHD and NSW. The pre-call telephone strategy provided accelerated benefit in closing this gap in HNELHD

The Interannual variability of hurricane activity in the Atlantic and east pacific regions

The investigation of the interannual and interdecadal variations in hurricane activity has been an important topic of study lately, especially with regard to their implications for climate change issues. On the interannual time-scale, the El Niño and Southern Oscillation (ENSO) phase has been correlated with hurricane activity in the Atlantic and Eastern Pacific Ocean Basins. For example, various atmospheric and oceanic parameters that influence hurricane development become significantly altered during an El Niño event, leading to suppressed easterly wave development and growth in the Atlantic, but more activity in the Eastern Pacific Ocean Basin. This study examined the interannual variability of hurricane intensity (measured as wind speed and interpreted through the Saffir-Simpson Scale) from 1938 through 2007 in the Atlantic and 1970 through 2007 in the Pacific basins, respectively. These data were then compared with the occurrence of El Niño/La Niña events as defined using the Japan Meteorological Association (JMA) index. El Niño/La Niña variability superimposed on variability associated with the Pacific Decadal Oscillation (PDO) was also examined here. Not surprisingly, during an El Niño year the intensity of Atlantic hurricanes was found to be weaker than during a neutral year or a La Niña year, but these conclusions were opposite in the Eastern Pacific Ocean Basin. There were also significant differences found in hurricane intensity between El Niño and La Niña years when the PDO was in phase 1 (warm phase), rather than when the PDO was in phase 2 (cool phase). This study also examined the interannual variation in hurricane intensity by genesis region (i.e. Atlantic: the eastern and western Atlantic Ocean Basins, the Caribbean, and the Gulf of Mexico; Eastern Pacific: divided into quadrants using 20o N and 125o W as the quadrant intersection point). Finally, the utility of this information in a long-range forecast application is demonstrated