Humidity and respiratory virus transmission in tropical and temperate settings

Influenza and respiratory syncytial virus (RSV) are similarly structured viruses with similar environmental survival, but different routes of transmission. While RSV is transmitted predominantly by direct and indirect contact, influenza is also transmitted by aerosol. The cold, dry conditions of temperate winters appear to encourage the transmission of both viruses, by increasing influenza virus survival in aerosols, and increasing influenza and RSV survival on surfaces. In contrast, the hot, wet conditions of tropical rainy seasons appear to discourage aerosol transmission of influenza, by reducing the amount of influenza virus that is aerosolized, and probably also by reducing influenza survival in aerosol. The wet conditions of tropical rainy seasons may, however, encourage contact transmission of both viruses, by increasing the amount of virus that is deposited on surfaces, and by increasing virus survival in droplets on surfaces. This evidence suggests that the increased incidence of influenza and RSV in tropical rainy seasons may be due to increased contact transmission. This hypothesis is consistent with the observation that tropical rainy seasons appear to encourage the transmission of RSV more than influenza. More research is required to examine the environmental survival of respiratory viruses in the high humidity and temperature of the tropics

Re-used Roman rubbish: a thousand years of recycling glass

The suitability of glass for re-melting and recycling was widely exploited in the past. This paper reviews the evidence, particularly for the 1st millennium AD, using examples from Western Europe. For much of this period glass was produced on a large-scale at a relatively small number of specialised glassmaking sites, which supplied numerous dispersed workshops where glass was modified and shaped. This is only part of the picture however, because the glassmakers, glassworkers and consumers were also linked by a complex, interdependent cycle of supply, use, discard, salvage and re-use, making recycling an essential part of interpreting archaeological glass

Clarity and brilliance: antimony in colourless natron glass explored using Roman glass found in Britain

This paper discusses the development of Roman antimony decolourised natron glass, its dominance, and subsequent decline, using new trace element data for colourless glass found in Britain. Experimental glasses are used to investigate the influence of different proportions of raw materials (particularly the ratio of natron to calcium carbonate) on the resulting transparency or opacity of glass when antimony is added. Focusing on the 1st to 3rd centuries AD, the study has found that (1) There are chronological differences in antimony colourless glass compositions including (a) some early vessels have abnormally low calcium, aluminium and barium levels; (b) 1st/mid-2nd-century AD vessels in Britain may also contain up to 0.6 wt% lead oxide whereas mid-2nd/3rd-century AD vessels contain less than 300 ppm, and (c) the antimony content tends to decline over time. (2) These developments can be linked to production and recycling practices; but trace elements suggest that all of these antimony colourless glasses share an origin, probably Egypt. (3) Crucially, production of experimental glasses illustrates the inherent suitability of a sodium-rich, calcium-poor base glass composition for making antimony colourless glass, as it readily dissolves added antimony; conversely lower-sodium, higher-calcium glasses start to form opacifying calcium-antimonate crystals with the same quantities of antimony. Thus, the sodium-rich, calcium-poor glass composition from Egypt was ideally suited for decolourising with antimony and formed a water-clear glass. The calcium-rich Syro-Palestine glasses were more easily opacified with antimony to make opaque glass, but were decolourised with manganese, not antimony

Moisture Meter Performance I. Corn Over Five Crop Years

The long-term accuracy of the 1981 Iowa-Illinois moisture-meter calibrations was evaluated by meter-to-oven comparisons on 2999 samples from the 1979-1983 crop years. Although the five-year average accuracy of the trade meters Steinlite SS250, Dickey-john GACII, and Motomco 919 was ±0.5 percentage point relative to the air-oven up to 25% moisture (wb), there was up to ± 0.7 point accuracy variation among crop years. A year-to-year component was added to the previously published variance model; this component represents about 35% of total variance of a meter test relative to an oven test

Investigating late Bronze Age glass beads from Stotfold, Bedfordshire, UK

A total of seventeen annular transparent blue glass beads and one cylindrical glass bead with opaque grey-white decoration were found at a site near Stotfold, in Bedfordshire, England. The beads were part of a cremation burial (without an urn), associated with small fragments of gold sheet and bone, and the latter were carbon dated to 1303-1052 calBC with 95% probability. Analysis (quantitative using SEM-EDS and qualitative using XRF) found that the beads are made from low magnesium, high potassium (LMHK) glass, of the type prevalent in Europe between around 1200 and 900 BC. The grey-white trail on the cylindrical bead is opacified in a novel way, as neither tin nor antimony colourants were used. These are only the second confirmed example of LMHK glass beads from England, and the earliest in date. They provide evidence of networks extending between this community and continental Europe in the Later Bronze Age, and the burial of a high-status individual at Stotfold. Experimental recreation is used to investigate the possible methods of making the glass, using plant ashes, copper oxide, and quartz sand. A multi-stage process is proposed, using a low temperature firing before the final high temperature melting and homogenising

Storage Device Sizing for a Hybrid Railway Traction System by Means of Bicausal Bond Graphs

In this paper, the application of bicausal bond graphs for system design in electrical engineering is emphasized. In particular, it is shown how this approach is very useful for model inversion and parameter dimensioning. To illustrate these issues, a hybrid railway traction device is considered as a case study. The synthesis of a storage device (a supercapacitor) included in this system is then discussed

Brief Report: An evaluation of an Australian autism-specific, early intervention programme

There is a relative paucity of evidence examining the effectiveness of early intervention for young children with Autism Spectrum Disorder, in particular those delivered through educationally-based programmes. This study aimed to evaluate the real world effectiveness of a community-based autism-specific early learning and intervention programme in Australia. Children enrolled between February 2010 and May 2013 who had a diagnosis of an Autism Spectrum Disorder was eligible to participate in the study. Fifty-nine children with a mean age of 3.98 years participated. Cognitive ability, language, autistic symptoms, and motor skills were assessed at baseline and follow up (12 months or at programme exit) using standardised measures. Pre- and post-measures were compared using paired sample t-tests. Significant improvements were found in receptive and expressive language, autism symptoms, and overall adaptive behaviour. No significant change was found in motor skills. Children with Autism Spectrum Disorder attending the community-based programme had significant gains particularly in domains of cognition and language. Study limitations are discussed

Superfluid Helium Tanker (SFHT) study

Replenishment of superfluid helium (SFHe) offers the potential of extending the on-orbit life of observatories, satellite instruments, sensors and laboratories which operate in the 2 K temperature regime. A reference set of resupply customers was identified as representing realistic helium servicing requirements and interfaces for the first 10 years of superfluid helium tanker (SFHT) operations. These included the Space Infrared Telescope Facility (SIRTF), the Advanced X-ray Astrophysics Facility (AXAF), the Particle Astrophysics Magnet Facility (Astromag), and the Microgravity and Materials Processing Sciences Facility (MMPS)/Critical Point Phenomena Facility (CPPF). A mixed-fleet approach to SFHT utilization was considered. The tanker permits servicing from the Shuttle cargo bay, in situ when attached to the OMV and carried to the user spacecraft, and as a depot at the Space Station. A SFHT Dewar ground servicing concept was developed which uses a dedicated ground cooling heat exchanger to convert all the liquid, after initial fill as normal fluid, to superfluid for launch. This concept permits the tanker to be filled to a near full condition, and then cooled without any loss of fluid. The final load condition can be saturated superfluid with any desired ullage volume, or the tank can be totally filed and pressurized. The SFHT Dewar and helium plumbing system design has sufficient component redundancy to meet fail-operational, fail-safe requirements, and is designed structurally to meet a 50 mission life usage requirement. Technology development recommendations were made for the selected SFHT concept, and a Program Plan and cost estimate prepared for a phase C/D program spanning 72 months from initiation through first launch in 1997