The 30 and 44GHz Back End Modules (BEM) for the Planck Low Frequency Instrument are broadband receivers (20% relative bandwidth) working at room temperature. The signals coming from the Front End Module are amplified, band pass filtered and finally converted to DC by a detector diode. Each receiver has two identical branches following the differential scheme of the Planck radiometers. The BEM design is based on MMIC Low Noise Amplifiers using GaAs P-HEMT devices, microstrip filters and Schottky diode detectors. Their manufacturing development has included elegant breadboard prototypes and finally qualification and flight model units. Electrical, mechanical and environmental tests were carried out for the characterization and verification of the manufactured BEMs. A description of the 30 and 44GHz Back End Modules of Planck-LFI radiometers is given, with details of the tests done to determine their electrical and environmental performances. The electrical performances of the 30 and 44GHz Back End Modules: frequency response, effective bandwidth, equivalent noise temperature, 1/f noise and linearity are presented.

OBJECTIVE:To identify virulence genes in enterotoxigenic E coli (ETEC) isolates associated with diarrhoea in neonatal, 1 to 3 week-old and weaned pigs in southeast Queensland.DESIGN:Multiplex PCR and serotyping were applied to E coli isolates obtained over a 5-year period (1998-2002) from cases diagnosed at Toowoomba Veterinary Laboratory.PROCEDURE:A total of 126 isolates from 25 different Queensland piggeries were tested for haemolytic activity on 5% sheep blood agar and by multiplex PCR for the presence of five commonly recognised fimbrial (F4, F5, F6, F41 and F18) and three enterotoxin genes (STa, STb, LT). A subset of 62 representative isolates were serotyped by slide agglutination. For comparative purposes, multiplex PCR was also performed on the DNA of 31 ETEC isolates from 9 serotypes originating from piggeries in southern New South Wales.RESULTS:A total of 113 (89.7%) of the isolates from Queensland possessed ETEC virulence genes, including 14 of 15 isolates from neonatal pigs (93.3%), 18 of 23 isolates from 1 to 3 week old pigs (78.3%) and 81 of 88 isolates from weaned pigs (92.1%). F4:STa:STb:LT (serotype O149) was the most prevalent pathotype in neonatal and 1-3 week old pigs and F4:STa:STb:LT (serotype O149) and F18:STa:STb:LT (serotype O141) were most prevalent in weaned pigs. In comparison, isolates obtained from neonatal pigs from New South Wales belonged to a more diverse range of pathotypes and serotypes.CONCLUSION:Multiplex PCR was a rapid and specific method for detecting the presence of ETEC virulence genes in porcine E coli isolates. For isolates obtained from cases of suspected colibacillosis in Queensland, growth of a heavy pure culture of haemolytic E coli was a sensitive prognostic indicator of the presence of ETEC virulence genes in the isolate. ETEC pathotypes and serotypes remained stable in Queensland piggeries over the five-year study period and appear to have changed little over the last three decades.

ObjectiveTo validate a polymerase chain reaction (PCR) based method, Enterobacterial Repetitive Intergenic Consensus‐PCR (ERIC‐PCR), for the fingerprinting ofHaemophilus parasuisstrains and to use that method to differentiate isolates from apparently related outbreaks of Glässers disease on three pig farms.DesignERIC‐PCR was evaluated by comparing 15 different strains that represented all 15 recognised serovars in the Kielstein‐Rapp‐Gabrielson (KRG) scheme for serotypingH parasuis. Next, ERIC‐PCR was used to examine 14 Australian field isolates ofH parasuis; 12 collected from three farms suffering apparently related outbreaks of Glässers disease and two from two other farms with no known connection.ResultsThe 15 serovar reference strains all gave unique, reproducible ERIC‐PCR fingerprints. The 12 isolates from the three apparently related outbreaks all gave a single fingerprint, which was distinct from any seen in the 15 serovar reference strains and the two other Australian field isolates in the studied farms. The confirmation that all 12 isolates were the same strain allowed the development of a prevention and control program that has prevented the emergence of any further outbreaks of Glässer disease on the three farms.ConclusionERIC‐PCR is a suitable technique for the differentiation of unrelated strains ofH parasuis. The finding that the 12 field isolates ofH parasuisall shared the same fingerprint is strong evidence that there was a common source of infection on all three farms. This study has shown, for the first time, that ERIC‐PCR is a suitable technique for the sub‐typing ofH parasuisand useful for studying the epidemiology of outbreaks of Glässers disease.

Biochemical profiles, restriction endonuclease analysis (REA) and ribotyping were used to investigate a total of 38 Pasteurella multocida isolates from four separate outbreaks of pasteurellosis in Australian piggeries. Six isolates were obtained from Outbreak 1, 16 from Outbreak 2 and eight each from outbreaks 3 and 4. Outbreaks 1 and 2 were cases of pneumonic pasteurellosis while outbreaks 3 and 4 involved systemic pasteurellosis. Biochemical characterisation established that a number of different types of P. multocida were present in outbreaks 1 and 3 while outbreaks 2 and 4 were associated with a single type of P. multocida. Outbreaks 1 and 3 yielded isolates of P. multocida that belonged to the subspecies multocida and gallicida, with the subspecies multocida isolates being identified as biovar 3 (6 in total) or 12 (1 in total) and the subspecies gallicida isolates (7 in total) being identified as biovar 8. All 24 isolates from outbreaks 2 and 4 belonged to the subspecies multocida and were all biovar 3. REA and ribotyping showed that, in outbreaks 1 and 3, there were three different types of P. multocida in each outbreak with no common strains between the outbreaks. The molecular methods showed that only a single strain of P. multocida was associated with outbreaks 2 and 4, although the outbreaks were associated with strains that differed in REA profiles but shared a ribotype profile. This study has shown that both, systemic and pneumonic pasteurellosis can be associated with either a single strain or multiple strains of P. multocida. The results also indicate that the molecular typing methods of REA and ribotyping are superior to biochemical characterisation for epidemiological investigation of porcine pasteurellosis.

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To determine the effect of respiratory infections on oxyhemoglobin saturation in a high-altitude population, we recorded clinical signs, oxyhemoglobin saturation determined by pulse oximetry, and findings on radiographs of the chest of 423 children with acute respiratory infections; the children were living at an altitude of 3750 m in the Peruvian Andes. We defined hypoxemia as an oxyhemoglobin saturation value greater than 2 SD below the mean value for 153 well children in this population. Eighty-three percent of children with clinical bronchopneumonia, but only 10% of children with upper respiratory tract infection, had hypoxemia (p < 0.001). Compared with previous studies of children living at lower altitudes, the presence of tachypnea was relatively nonspecific as a predictor of radiographically determined pneumonia or of hypoxemia, especially in infants. A history of rapid breathing was 74% sensitive and 64% specific in the prediction of hypoxemia, and performed as well as a standard World Health Organization case management algorithm in the prediction of radiographic pneumonia or hypoxemia. Radiographic pneumonia was not a sensitive predictor of hypoxemia or clinically severe illness. In contrast, the presence of hypoxemia was a useful predictor of radiographic pneumonia, with both sensitivity and specificity of 75% in infants. We conclude that acute lower respiratory tract infection in children living at high altitude is frequently associated with hypoxemia, and that oxygen should be administered to children with a diagnosis of pneumonia in these regions. Case management algorithms developed in low-altitude regions may have to be modified for high-altitude settings. In this setting, pulse oximetry is a good predictor of pneumonia. Because pulse oximetry is more objective and cheaper than radiography, its role as a clinical and investigative tool merits further exploration.

The influence of already formed polymer chains on the photopolymerization of the diacetylene crystal pTS has been studied using the holographic method. It is shown that, for wavelengths between 340 and 400 nm, photopolymerization occurs and is faster in more polymerized regions. This sensitized process does not involve polymer excited states, but most probably the monomer triplet. It is a two-quantum process. It is proposed that this “sensitization” is in fact due to the elastic effects of polymer chains into the surrounding monomer matrix.

Varying the ionic concentration of aqueous solutions bathing a liquid arti- ficial membrane (phospholipids dissolved in an organic solvent with a weak dielectric constant and impregnating a teflon millipore filter), lipid-ion interactions on phospholipid organization have been demonstrated inside the membranes.The conductance, g, has been measured.There was a close and significant correlation between the increase of g and the variation in ionic concentration ; g did not increase continuously but in sequential steps to reach a plateau at high concentrations, whatever phospholipid was used, mono- valent cation studied or pH chosen.This sequential step increase of g could be explained by the following hypothesis : inside and on the surface of the membrane, polar groups organized into three different types according to the ionic concentration of aqueous solu- tions ; if the organization remained the same, the energy environment changed under the influence of the surrounding medium.Introduction.