Microbial contamination of food refrigeration equipment

Refrigeration systems in chilled rooms in 15 plants processing a variety of foods were studied. These included plants processing raw meat and salads, Chinese ready meals, dairy products, slicing and packing of cooked meats and catering establishments. An initial survey of total numbers of microbes at a total of 891 sites on evaporators, drip trays and chilled room walls was followed up with a more detailed examination of 336 sites with high counts, selecting for Listeria spp., coliforms, enterococci, Staphylococcus aureus and Bacillus cereus. Temperatures (particularly air on and air off, maximum and near defrost heaters) relative humidity, airflow, layout and cleaning regimes were surveyed. In general, no correlation could be found between any of the physical measurements and the numbers and types of bacteria detected. Maximum mean temperatures in the chilled rooms varied from -1 to +16.9 °C and few chilled units were regularly cleaned. Twenty five percent of sites examined had more than 105 colony-forming units per cm2, although, very few pathogens or faecal indicator bacteria were detected. Listeria spp. were not found and coliforms were found only once, in low numbers. Low numbers of S. aureus or B. cereus were present in 9 of the 15 plants, B. cereus was found on evaporators and associated drip trays in two catering plants and two plants processing cooked meat. Enterococci and S. aureus were found most frequently in a raw red meat slaughterhouse (always in low numbers). In general, microbial contamination was lower in rooms where wrapped rather than unwrapped products were stored. The type of product also affected the degree of contamination, with raw red meat and poultry or dry ingredients giving highest counts, and raw vegetables and cooked products lowest. The work demonstrated that bacteria were present on evaporator cooling coils in all factory cold rooms visited. Although evaporator-cleaning procedures were carried out in some factories as part of routine maintenance these were not shown to be effective at maintaining low levels of bacteria on evaporators. To maintain evaporator hygiene it is suggested that more regular cleaning procedures, possibly by means of automated cleansing systems, should be considered. © 2003 Elsevier Ltd. All rights reserved

Systematic Observations of the Availability and Use of Instructional Technology in Urban Middle School Classrooms

The present study uses systematic observations to investigate the availability and use of instructional technology in 64 middle school classrooms serving predominantly minority students from economically disadvantaged families. The T3 Overall Classroom Observation Measure, a high-inference walk-through instrument, was developed to examine: (a) types and use of technology present in the classroom, (b) teachers’ technology usage, (c) students’ technology usage, (d) teachers’ general instructional behaviors, and (e) students’ general behaviors. The results revealed that instructional technology was widely available in the classrooms, but most teachers and students were only using it to “some extent.

A Sr-Rich Star on the Main Sequence of Omega Centauri

Abundance ratios relative to iron for carbon, nitrogen, strontium and barium are presented for a metal-rich main sequence star ([Fe/H]=--0.74) in the globular cluster omega Centauri. This star, designated 2015448, shows depleted carbon and solar nitrogen, but more interestingly, shows an enhanced abundance ratio of strontium [Sr/Fe] ~ 1.6 dex, while the barium abundance ratio is [Ba/Fe]<0.6 dex. At this metallicity one usually sees strontium and barium abundance ratios that are roughly equal. Possible formation scenarios of this peculiar object are considered.Comment: 13 pages, 3 figures. Accepted to ApJ

Changes in the red giant and dusty environment of the recurrent nova RS Ophiuchi following the 2006 eruption

We present near-infrared spectroscopy of the recurrent nova RS Ophiuchi (RS Oph) obtained on several occasions after its latest outburst in 2006 February. The 1–5 μm spectra are dominated by the red giant, but the H i, He i and coronal lines present during the eruption are present in all our observations. From the fits of the computed infrared spectral energy distributions to the observed fluxes, we find Teff= 4200 ± 200 K for the red giant. The first overtone CO bands at 2.3 μm, formed in the atmosphere of the red giant, are variable. The spectra clearly exhibit an infrared excess due to dust emission longward of 5 μm; we estimate an effective temperature for the emitting dust shell of 500 K, and find that the dust emission is also variable, being beyond the limit of detection in 2007. Most likely, the secondary star in RS Oph is intrinsically variable

Black hole candidate XTE J1752-223: Swift observations of canonical states during outburst

We present Swift broadband observations of the recently discovered black hole candidate, X-ray transient, XTE J1752-223, obtained over the period of outburst from October 2009 to June 2010. From Swift-UVOT data we confirm the presence of an optical counterpart which displays variability correlated, in the soft state, to the X-ray emission observed by Swift-XRT. The optical counterpart also displays hysteretical behaviour between the states not normally observed in the optical bands, suggesting a possible contribution from a synchrotron emitting jet to the optical emission in the rising hard state. We offer a purely phenomenological treatment of the spectra as an indication of the canonical spectral state of the source during different periods of the outburst. We find that the high energy hardness-intensity diagrams over two separate bands follows the canonical behavior, confirming the spectral states. Our XRT timing analysis shows that in the hard state there is significant variability below 10Hz which is more pronounced at low energies, while during the soft state the level of variability is consistent with being minimal. These properties of XTE J1752-223 support its candidacy as a black hole in the Galactic centre region.Comment: 8 pages, 8 figures; MNRAS in pres

The expanding dusty bipolar nebula around the nova V1280 Sco

V1280 Sco is one of the slowest dust-forming nova ever historically observed. We performed multi-epoch high-spatial resolution observations of the circumstellar dusty environment of V1280 Sco to investigate the level of asymmetry of the ejecta We observed V1280 Sco in 2009, 2010 and 2011 using unprecedented high angular resolution techniques. We used the NACO/VLT adaptive optics system in the J, H and K bands, together with contemporaneous VISIR/VLT mid-IR imaging that resolved the dust envelope of V1280 Sco, and SINFONI/VLT observations secured in 2011. We report the discovery of a dusty hourglass-shaped bipolar nebula. The apparent size of the nebula increased from 0.30" x 0.17" in July 2009 to 0.64" x 0.42" in July 2011. The aspect ratio suggests that the source is seen at high inclination. The central source shines efficiently in the K band and represents more than 56+/-5% of the total flux in 2009, and 87+/-6% in 2011. A mean expansion rate of 0.39+/-0.03 mas per day is inferred from the VISIR observations in the direction of the major axis, which represents a projected upper limit. Assuming that the dust shell expands in that direction as fast as the low-excitation slow ejecta detected in spectroscopy, this yields a lower limit distance to V1280 Sco of 1kpc; however, the systematic errors remain large due to the complex shape and velocity field of the dusty ejecta. The dust seems to reside essentially in the polar caps and no infrared flux is detected in the equatorial regions in the latest dataset. This may imply that the mass-loss was dominantly polar

The role of children in their HIV-positive parents’ management of antiretroviral therapy in Uganda

Adjustment to life on antiretroviral therapy (ART) and living with HIV as a long-term chronic condition, pose significant medical, social and economic challenges. We investigated children’s role in supporting HIV-positive parents to self-manage life on ART. Between 2010 and 2012, we conducted a qualitative study using semi-structured interviews with 38 HIV-positive parents who had been on ART for over a year. They were randomly selected from people accessing ART from three delivery sites in Wakiso district, Uganda. Data were analysed thematically. Participants reported children between the ages of 1 and 47 years providing support. Children were a source of happiness, self-worth, encouragement, and comfort. Both younger and older children supported parents’ adherence to treatment through reminding them to take the drugs and honour clinic appointments. Older children provided money to buy medication, food and shelter. Parents reported that the encouragement they received after they disclosed to their children enhanced their survival. After HIV disclosure to their children many of their fears about the future were allayed. Thinking about their children’s future brought hope. However, looking after younger children while on ART could be burdensome since some parents could not work to their full capacity due to reduced physical health. Children are an important resource in their parents’ adjustment to living with HIV while taking ART. There is a need for children to be supported by appropriate policy and other social and health development structures

The Early Spectrophotometric Evolution of V1186 Scorpii (Nova Scorpii 2004 #1)

We report optical photometry and optical through mid-infrared spectroscopy of the classical nova V1186 Sco. This slowly developing nova had an complex light curve with multiple secondary peaks similar to those seen in PW Vul. The time to decline 2 magnitudes, t$_2$, was 20 days but the erratic nature of the light curve makes determination of intrinsic properties based on the decline time (e.g., luminosity) problematic, and the often cited MMRD relationship of Della Valle and Livio (1995) fails to yield a plausible distance. Spectra covering 0.35 to 35 $\mu$m were obtained in two separate epochs during the first year of outburst. The first set of spectra, taken about 2 months after visible maximum, are typical of a CO-type nova with narrow line emission from \ion{H}{1}, \ion{Fe}{2}, \ion{O}{1} and \ion{He}{1}. Later data, obtained between 260 and 380 days after maximum, reveal an emerging nebular spectrum. \textit{Spitzer} spectra show weakening hydrogen recombination emission with the emergence of [\ion{Ne}{2}] (12.81 $\mu$m) as the strongest line. Strong emission from [\ion{Ne}{3}] (15.56 $\mu$m) is also detected. Photoionization models with low effective temperature sources and only marginal neon enhancement (Ne $\sim$ 1.3 Ne$_{\odot}$) are consistent with these IR fine-structure neon lines indicating that V1186 Sco did not occur on a ONeMg white dwarf. In contrast, the slow and erratic light curve evolution, spectral development, and photoionization analysis of the ejecta imply the outburst occurred on a low mass CO white dwarf. We note that this is the first time strong [\ion{Ne}{2}] lines have been detected so early in the outburst of a CO nova and suggests that the presence of mid-infrared neon lines is not directly indicative of a ONeMg nova event.Comment: 7 figures, 37 pages. Astronimocal Journal accepte