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Raw materials used in feed manufacture are contaminated with high (>104 cfu/g) levels of enterobacteriaceae indicating the potential for contamination with pathogenic bacteria such as salmonella (Wood et al. 2001). There is urgent need to reduce the contamination of animal feed with zoonoses such as salmonella and campylobacter. During manufacture of feedingstuffs, heat and moisture are used to process and sterilise feed but this can also provide conditions for microbial growth. High temperature treatment used to sterilise feed will not protect feedingstuffs from recontamination, if residual microbial contamination remains in the feed mill. It is essential to understand the influence of feed processing and the feed mill environment on the microbial contamination of feed.
Bacteria belonging to the family Enterobacteriaceae enter the animal feed chain as normal contaminants of raw materials used in the manufacture of animal feeds. The family Enterobacteriaceae encompasses 30 established genera, including Salmonella spp, Escherichia spp, Shigella spp and Yersinia spp. Many of the genera exhibit pathogenicity towards man, animals, insects and plants and many of the pathogenic forms produce toxins. A number of the genera in this family occur regularly in association with animals; they are found as indigenous members of the gut microflora where they may either produce no harmful effects, or are capable of causing disease in both endothermic and ectothermic animals. There is a recognised association between the risk of isolation of salmonella and degree of Enterobacteriaceae contamination (Veldman et al. 1995). This has led to the consideration of recording Enterobacteriaceae contamination levels in feed stuffs as an indicator of feed hygiene and potential limits to the degree of contamination being set by the major retailers. This paper sets out data gathered from the routine analysis of feed raw materials examined for Enterobacteriaceae contamination.
The observational material for this study consists of a series of 19 I plates (IVN+RG715) of the southern half of the LMC taken by the UK Schmidt Telescope over a six year period from 1977–1983. A small region of size 28′x56′ centred on α(1950) = 5 28 50.7, δ(1950) = −69 31 56 was scanned on all plates with a PDS microdensitometer and magnitudes were derived for typically 14000 stars per scan area. All magnitudes were converted to a common system by comparison of magnitudes to a standard plate; this comparison showed the individual rms measurement error to be 0.13 mag. No photoelectric standard sequence exists in the region studied but the instrumental magnitudes have been converted to preliminary IK magnitudes by using the IK magnitudes given by Blanco, McCarthy and Blanco (1980) for some of the red stars in the field.
An 8-cm optical telescope is constructed for use at the south pole. It is designed to make photoelectric observations of selected stars continuously through an austral winter. The automated operation is controlled by a computer. The aim is to study the variability of the star γ2 Velorum as well as the condition of the polar sky and the performance of the instrument.
A legionellosis outbreak at an industrial site was investigated to identify and control the source. Cases were identified from disease notifications, workplace illness records, and from clinicians. Cases were interviewed for symptoms and risk factors and tested for legionellosis. Implicated environmental sources were sampled and tested for legionella. We identified six cases with Legionnaires’ disease and seven with Pontiac fever; all had been exposed to aerosols from the cooling towers on the site. Nine cases had evidence of infection with either Legionella pneumophila serogroup (sg) 1 or Legionella longbeachae sg1; these organisms were also isolated from the cooling towers. There was 100% DNA sequence homology between cooling tower and clinical isolates of L. pneumophila sg1 using sequence-based typing analysis; no clinical L. longbeachae isolates were available to compare with environmental isolates. Routine monitoring of the towers prior to the outbreak failed to detect any legionella. Data from this outbreak indicate that L. pneumophila sg1 transmission occurred from the cooling towers; in addition, L. longbeachae transmission was suggested but remains unproven. L. longbeachae detection in cooling towers has not been previously reported in association with legionellosis outbreaks. Waterborne transmission should not be discounted in investigations for the source of L. longbeachae infection.
A low-cost differential image motion monitor (DIMM), consisting of an 11-inch Celestron, an SBIG ST-4 autoguiding CCD camera and a PC, is described. Two such systems were used during June–July and November–December 1993 to make near-simultaneous seeing measurements at Freeling Heights in the Northern Flinders Ranges and at Siding Spring Observatory. The results of these campaigns show that the seeing-distribution is generally similar at both sites, with the most common seeing value being ~l·2″. Siding Spring does, however, have slightly more bad seeing (>2″) than Freeling Heights. Weather records from Arkaroola Resort (15 km south of Freeling Heights) indicate that there is ~15% less cloud cover at Freeling Heights than at Siding Spring. Episodes of rapid seeing deterioration at Siding Spring in winter are shown to coincide with warm air masses crossing the mountain.
The Report in the part dealing with the minor planets and satellites has been compiled at the Institute of Theoretical Astronomy in collaboration of S. G. Makover (minor planets) and V. A. Shor (satellites). Contributions to this report have been received from S. Arend, H. Debehogne, J. Dommanget, P. Herget, S. Herrick, G. M. Jannini, B. G. Marsden, V. V. Michkovitch, B. Milet, Z. M. Pereyra, B. Popovič, E. Rabe, E. Roemer, J. Schubart, W. Strobel, C. Torres, H. Wood. The part on comets has been prepared by E. Roemer.
The main feature of minor planet research during this triennium has been the further application of modern electronic computing machines to the practice of computing. The time has gone when the computations of orbits and ephemerides were performed with the aid of logarithmic tables or with desk calculators. Therefore it is no wonder that all computational work in the field of the motion of minor planets is nowadays concentrated in a limited number of institutions provided with powerful up-to-date computing techniques, like the following.
(1)Institute of Theoretical Astronomy, Leningrad has used till recently a computer BESM-2 and now has at its disposal a new more powerful computer BESM-4.
(2)The Observatory of Cincinnati has used till recently a powerful computer NORC. Unfortunately this machine has been nowadays dismantled, but the observatory can perform some kinds of computations with an IBM-360 computer.
(3)Latvian State University, Riga, has made a large amount of computations with the computer BESM-2.
(4)University of California, Los Angeles, makes a large amount of computations with its own computer.
There is a conspicuous gap in plans for X-ray timing after the X-ray Timing Explorer (XTE). Timing science has played a critical role in the development of X-ray astronomy. The need now is to move into a new domain of shorter timescales and weaker modulation, one that can be reached only with very large aperture instruments. XLA is an X-ray facility with an aperture substantially greater than 1 m2, nominally 100 m2. Most of this area is devoted to a large array of collimated proportional counters. There is also a ~ 1 m2 coded aperture. It extends observational parameter space by several orders of magnitude in timing resolution, sensitivity to variability, and angular resolution. This will lead to a qualitatively new kind of X-ray astrophysics that can be applied to the study of a broad range of astrophysical objects. XLA is thus both an advanced timing mission and a general purpose facility whose principal uses are in areas that are not well covered in other aspects of the planned High Energy Astrophysics program.
The variability of CD-24 7599 (V=11.48 mag) was discovered by JCC during observing run XCOV7 of the Whole Earth Telescope (WET, Nather et al. 1990) network in February, 1992. The star was observed as an additional target and 117 hours of high-quality temporal spectroscopic observations were obtained.
Our analysis of these data revealed the presence of 7 independent pulsation modes between 27.0 and 38.1 cycles per day (313 – 441 μHz) with semiamplitudes of 2.1 – 10.2 milli-modulation amplitudes (mma). We showed that peaks at linear combination frequencies detected in the power spectra were not due to eigenmodes excited to visible amplitude by resonant mode coupling.
Several outbreaks of hepatitis A in men who have sex with men (MSM) were reported in the 1980s and 1990s in Australia and other countries. An effective hepatitis A virus (HAV) vaccine has been available in Australia since 1994 and is recommended for high-risk groups including MSM. No outbreaks of hepatitis A in Australian MSM have been reported since 1996. In this study, we aimed to estimate HAV transmissibility in MSM populations in order to inform targets for vaccine coverage in such populations. We used mathematical models of HAV transmission in a MSM population to estimate the basic reproduction number (R0) and the probability of an HAV epidemic occurring as a function of the immune proportion. We estimated a plausible range for R0 of 1·71–3·67 for HAV in MSM and that sustained epidemics cannot occur once the proportion immune to HAV is greater than ~70%. To our knowledge this is the first estimate of R0 and the critical population immunity threshold for HAV transmission in MSM. As HAV is no longer endemic in Australia or in most other developed countries, vaccination is the only means of maintaining population immunity >70%. Our findings provide impetus to promote HAV vaccination in high-risk groups such as MSM.
Major depressive disorder (MDD) is a common and disabling condition with well-established heritability and environmental risk factors. Gene–environment interaction studies in MDD have typically investigated candidate genes, though the disorder is known to be highly polygenic. This study aims to test for interaction between polygenic risk and stressful life events (SLEs) or childhood trauma (CT) in the aetiology of MDD.
The RADIANT UK sample consists of 1605 MDD cases and 1064 controls with SLE data, and a subset of 240 cases and 272 controls with CT data. Polygenic risk scores (PRS) were constructed using results from a mega-analysis on MDD by the Psychiatric Genomics Consortium. PRS and environmental factors were tested for association with case/control status and for interaction between them.
PRS significantly predicted depression, explaining 1.1% of variance in phenotype (p = 1.9 × 10−6). SLEs and CT were also associated with MDD status (p = 2.19 × 10−4 and p = 5.12 × 10−20, respectively). No interactions were found between PRS and SLEs. Significant PRSxCT interactions were found (p = 0.002), but showed an inverse association with MDD status, as cases who experienced more severe CT tended to have a lower PRS than other cases or controls. This relationship between PRS and CT was not observed in independent replication samples.
CT is a strong risk factor for MDD but may have greater effect in individuals with lower genetic liability for the disorder. Including environmental risk along with genetics is important in studying the aetiology of MDD and PRS provide a useful approach to investigating gene–environment interactions in complex traits.
Los Alamos National Laboratory has calculated a new generation of radiative opacities (OPLIB data using the ATOMIC code) for elements with atomic number Z = 1-30 with improved physics input, updated atomic data, and finer temperature grid to replace the Los Alamos LEDCOP opacities released in the year 2000. We calculate the evolution of standard solar models including these new opacities, and compare with models evolved using the Lawrence Livermore National Laboratory OPAL opacities (Iglesias & Rogers 1996). We use the solar abundance mixture of Asplund et al. 2009. The Los Alamos ATOMIC opacities (Colgan et al. 2013a, 2013b, 2015) have steeper opacity derivatives than those of OPAL for temperatures and densities of the solar interior radiative zone. We compare the calculated nonadiabatic solar oscillation frequencies and solar interior sound speed to observed frequencies and helioseismic inferences. The calculated sound-speed profiles are similar for models evolved using either the updated Iben evolution code (see Guzik & Mussack 2010), or the MESA evolution code (Paxton et al. 2015). The LANL ATOMIC opacities partially mitigate the ‘solar abundance problem’.
Although risk for psychosis in velocardiofacial (22q11.2 deletion) syndrome (VCFS) is well established, the cognitive and familial factors that moderate that risk are poorly understood.
A total of 75 youth with VCFS were assessed at three time points, at 3-year intervals. Time 1 (T1) psychiatric risk was assessed with the Behavior Assessment System for Children (BASC). Data reduction of BASC scores yielded avoidance–anxiety and dysregulation factors. Time 2 (T2) neuropsychological and family function and time 3 (T3) prodromal/overt psychosis were assessed. Poisson regression models tested associations between T3 positive prodromal symptoms/overt psychosis and T1 psychiatric risk, T2 cognitive and familial factors, and their interactions.
T1 avoidance–anxiety ratings predicted T3 prodromal/overt psychosis. T2 verbal learning scores moderated this association, such that individuals with low avoidance–anxiety scores and stronger verbal learning skills were the least likely to demonstrate prodromal/overt psychosis at T3. Low scores on a T2 visual vigilance task also predicted T3 prodromal/overt psychosis, independently of the effect of T1 avoidance–anxiety scores. T1 dysregulation scores did not predict T3 prodromal/overt psychosis in a linear manner. Instead, the association between dysregulation and prodromal/overt psychosis was amplified by T2 levels of family organization, such that individuals with low dysregulation scores and low family organization scores were the most likely to exhibit T3 prodromal/overt psychosis.
Significant moderators of psychiatric risk in VCFS include verbal learning skills as well as levels of family organization, carrying implications for early identification and preventative treatment of youth with VCFS at highest risk for psychosis.