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The objective of this study was to determine effects of room temperature and drinker design on growth and water disappearance of growing-finishing pigs (26.9 ± 3.67 to 130.9 ± 5.10 kg live body weight). A split-plot design was used with a 2 × 2 factorial arrangement of treatments: Room Temperature (RT) [Thermoneutral (TN) vs. High (HI); main plot], Drinker Design (DD; Nipple vs. Cup; sub-plot). A total of 316 pigs were used, housed in 32 pens in 4 rooms (8 pens/room; 7 pens of 10 pigs and 1 pen of 9 pigs). Two rooms were on each RT treatment. Room temperature for the TN treatment was constant throughout each day but decreased from 24°C at the start to 20°C and 18°C on d 14 and 45 of the study period, respectively. For the HI treatment, a single, cyclic RT protocol was used throughout the study (30°C from 08:00 to 19:00 h and 20°C from 20:00 to 07:00 h, with 1-h transition periods). Pens had fully-slatted concrete floors and 1 feeder and drinker (either nipple or cup); floor space was 0.67 m2/pig. Pigs had ad libitum access to standard corn-soybean diets, formulated to meet or exceed NRC (2012) nutrient requirements. Water disappearance was measured using a meter fitted to the water line supplying each drinker. There were no interactions (P > 0.05) between RT and DD treatments. Drinker Design did not affect (P > 0.05) growth performance; water disappearance was 7.3% greater (P ≤ 0.05) for Nipple than Cup drinkers. Compared to the TN treatment, the HI treatment had no effect (P > 0.05) on gain:feed ratio, but resulted in lower (P ≤ 0.05) average daily gain (6.5%) and average daily feed intake (5.5%) and greater (P ≤ 0.05) average daily water disappearance (16.8%). These results suggest that both drinker design and RT can affect water disappearance, and that the high, cyclic RT regime used reduced growth performance of growing-finishing pigs. Further research is needed to determine the contribution of water intake and wastage to treatment differences in water disappearance.

This study was conducted to evaluate the water disappearance of nursery pigs (from weaning to 6 wk post-weaning; 6.4 ± 1.07 to 22.0 ± 3.39 kg live body weight) using a randomized complete block design to compare two Drinker Type treatments: Nipple vs. Cup. A total of 336 pigs housed in 16 pens with 21 pigs per pen in 2 rooms (8 pens per room) were used. Pens had fully-slatted concrete floors; floor space was 0.32 m2/pig and there was one feeder and one drinker per pen. Pigs were fed corn-soybean–based diets formulated to meet or exceed nutrient requirements. Pigs and feeders were weighed at the start and end of the study. Water disappearance was measured using a water-flow meter fitted to the water pipeline supplying the drinker in each pen. For the overall study period, Drinker Type did not affect (P > 0.05) growth performance; however, average daily water disappearance was greater (P

Summary The distribution and type of solid bitumen at different thermal maturities is characterized by a combined approach of organic geochemical and petrographic investigations. Different maturities are present as both naturally achieved as well as by open system pyrolysis of small rock pieces placed into Rock-Eval crucibles. Our first results show, that a certain fraction of the bitumen has a high thermal stability and is detected as the S2 peak rather than S1. Further, the isothermal temperature of 300°C for 3 minutes is not able to fully extract the observable solid bitumen from the rock pieces. In contrast, the amount of solid bitumen in pores increases as well as its reflectivity, indicating remigration from the inner part of the rock towards its surface. Pyrolysis at higher temperatures also creates new solid bitumen filling pores that have been empty in the initial state.

Mixed-refrigerant cycles (MRC) are state-of-the-art for efficient LNG production. The development of cryogenic mixed-refrigerant cycles (CMRC) at temperatures below 100 K relies on physical property data of cryogenic mixtures such as vapor-liquid equilibria and enthalpies. This data is insufficient for some binary mixtures and unavailable for most multi-component systems. The cryogenic phase equilibria test stand CryoPHAEQTS provides precise physical property data of cryogenic fluid mixtures at temperatures from 15 K to 300K and at pressures up to 150 bar. Contrary to previous apparatus in the literature, CryoPHAEQTS uses cooling of the equilibrium cell by a pulse-tube cryocooler. Temperature is measured by two CERNOX® sensors directly immersed in the liquid/vapor phase. Pressure is measured through a capillary and a differential pressure sensor connected to a secondary system containing three high precision sensors. Up to three occurring phases can be sampled directly from the cell and analyzed by gas chromatography. Measurement uncertainties are ±13mK in temperature, ±1 mbar in pressure and ±1% in composition. Prior to publishing new phase equilibrium data, the test stand is benchmarked against available vapor-liquid equilibrium data of the widely investigated nitrogen-argon system. In this paper, we report on the first measurement results of cryogenic mixtures in CryoPHAEQTS and compare them against the literature data.

The purpose of this study is to compare possible superconducting 380-kV cables with existing overhead lines and underground cables. The study compares the required corridors and energy losses of different versions of a 1.7-km transmission system with a power of 6.6 GVA. Comparison covers the following setups: 4 × 380 kV high-voltage overhead lines, 8 × 380 kV conventional cables, 2 × 380 kV and 4 × 380kV superconducting cables with warm and cold dielectrics. The paper will present the description of the different setups as well as the calculation of energy losses. The required widths of the underground cable corridors are also considered in this study. Finally, the temperature profile and pressure drop of the superconducting cables are investigated. The main results can be summarized as follows. 1) For the assumed voltage level and power, overhead lines require a corridor width of 70 m, whereas a corridor of less than 7.7 m in width is necessary for superconducting 380 kV cables. 2) The 380-kV superconducting cable reduces the energy loss by approximately 8100 MWh per year in comparison to the conventional overhead lines. This yields a feasible energy loss reduction of up to 75%.

Thermal joining of materials with dissimilar thermo-physical properties requires an efficient and adaptable energy input that does not lead to thermal damage of the joining partners. Reactive particles provide a promising solution for this purpose as they represent a tailorable heat source by being able to undergo an exothermic, self-sustaining reaction. A sophisticated method of initiating the reaction is the use of microwaves, since they allow high heating rates, volumetric heating, and may influence the reaction even after the activation. In this way, particles consisting of nickel and aluminium can generate temperatures up to 1550 K within a few hundred milliseconds. However, high reaction rates, elevated temperatures, and still not fully understood microwave-specific phenomena complicate the derivation of cause-effect relationships. Therefore, an experimental set-up was developed, in which the reactive particles can be activated either in the predominant magnetic or electric field due to a customised resonant cavity. Elaborate high-temperature and several power measurement methods were implemented to characterise the activation and reaction behaviour of particles with a lamellar intrinsic structure. Both the electromagnetic field and the particle size influenced the resulting temperature-time profiles and arcing phenomena. In order to demonstrate the potential of reactive particles, they were also used as a new heat source in microwave-assisted adhesive bonding. An empirical study showed that microwaves and reactive particles interacted in an advantageous way with epoxy resins, promoted the cross-linking of the polymers, and allowed the fabrication of polypropylene joints in the microwave cavity.

The features of severe ischemic brain damage after strangulation by the owner of a 1-year-old German shepherd dog are described. The dog was disciplined by the owner during training by holding the dog off the ground by his choke chain collar. At first, the dog behaved normally, but he became increasingly ataxic and started circling to the left and showed reduced consciousness. The neurological examination revealed severe disorientation, left lateral pleurothotonus, and circling. The neurological findings were consistent with a multifocal brain lesion. A magnetic resonance imaging scan was performed and showed changes in the T2- and diffusion-weighted images, consistent with severe cerebral edema resulting from ischemia. Because of the severity of the clinical features, the dog was later euthanized. To the author's knowledge, this is the first report of a severe brain ischemia after strangulation in a dog.

The objective was to determine the predictive ability of carcass length for the number of equal-thickness chops obtained from a boneless pork loin. Longer pork carcasses are assumed to yield longer loins and, therefore, an increased number of chops. Loins were collected from pigs (1,238 total) raised under commercial conditions and marketed when the mean pig weight in a pen reached 138 kg. Pigs were slaughtered over 7 wk in a commercial facility. Carcass length was measured at 1 d postmortem on the left side of each carcass from the anterior edge of the symphysis pubis bone to the anterior edge of the first rib. Carcasses were fabricated, and boneless loins (North American Meat Processors number 414) were vacuum packaged and transported to the University of Illinois Meat Science Laboratory. Loins were stored at 4°C for 14 d. At the end of the aging period, loins were weighed, measured for stretched length (stretched to maximum length without distortion) and compressed length (compressed to minimum length without distortion), and sliced into 2.54-cm-thick chops. Boneless chops were counted and weighed. Carcass length ranged from a minimum of 78.2 cm to a maximum of 96.5 cm and the number of boneless chops ranged from a minimum of 13 to a maximum of 20 chops. Data were analyzed using the regression procedure of SAS. The dependent variable was the number of boneless chops. Coefficient of determination () was calculated for carcass length, boneless loin weight, compressed loin length, and stretched loin length. Carcass length explained 15% ( < 0.0001) of the variation in the number of loin chops. Loin weight explained 33% ( < 0.0001) of the variation in the number of loin chops. Compressed loin length and stretched loin length explained 28 and 8% ( < 0.0001), respectively, of the variation in the number of loin chops. Multiple linear regression was used to determine a predictive equation for the number of loin chops using the stepwise selection option of all independent variables. The combination of boneless loin weight, compressed loin length, 10th-rib carcass fat depth, and carcass length explained 45% of the variation ( < 0.0001; C(p) = 16.76) in the number of loin chops using a required statistic at the SLENTRY and SLSTAY level = 0.15. Overall, carcass length is a poor predictor of the number of equal-thickness loin chops that can be derived from a boneless pork loin.

The Karlsruhe Tritium Neutrino Experiment (KATRIN) will measure the mass of the electron antineutrino with a sensitivity of 0.2 eV / c 2 , based on the precise measurement of the T 2 β spectrum in a region close to the endpoint. This requires a T 2 source, which can provide 10 11 β decay electrons per second. The KATRIN source cryostat consists in its centre of a 10 m long beam tube of 90 mm inner diameter, operated at 30 K. Molecular T 2 is injected in the beam tube through a central injection chamber and pumped at either tube end. The T 2 density profile must have a stability of 10 - 3 in order to limit the systematic errors, yielding stringent requirements on the beam tube temperature homogeneity and stability of ± 30 mK . This shall be achieved with a design, where the thermal radiation from the vacuum pumps is almost entirely absorbed by LN 2 and He heat exchangers on the pump ports. The beam tube itself is cooled with two-phase tubes that are part of a Ne thermosiphon. After describing the thermal environment of the beam tube, the design parameters and the operational limits of the thermosiphon will be discussed. This is followed by a detailed analysis of its dynamic behaviour, based on experimental data taken in the primary He cooling system. A “tailor-made” Ne condenser design is presented, enabling the suppression of the primary He temperature variations by two orders of magnitude, from c. ± 0.3 K to below ± 3 mK .

We are studying the operation of silicon microstrip detector with readout electronics in the temperature range from 90 to 130 K. The sensor can be operated in the current-injection mode which significantly improves its radiation hardness. A first module prototype has been built, with APV25 readout chips and an embedded microtube, providing efficient low-mass cooling of the whole module with a two-phase flow of N 2 or Ar. First pedestal and pulse shape temperature dependencies are presented for this module. We have also built an edgeless test module with two pairs of laser cut sensors, with both angular and parallel cuts with respect to the strips (at 120 μ m pitch). We are studying the efficiency of the microstrip sensors very close ( 200 μ m ) to the physical border of the cut silicon crystal and present here some electrical characteristics.

Defensins are antibiotic peptides that are involved in host defence at epithelial and mesenchymal surfaces. Previous studies have shown the induction of human beta-defensin-3 (HBD-3) in osteoarthritic joints, suggesting that these molecules have functions in addition to their ability to kill microbes. The aim of this study was to investigate the production of a further human beta-defensin, named HBD-2, in osteoarthritis (OA) and to determine its regulation by inflammatory cytokines. Healthy and osteoarthritic cartilage was assessed for HBD-2 expression by RT-PCR, immunohistochemistry, and ELISA. C28/I2 chondrocytes, primary chondrocytes, and cartilage explants were cultured for in vitro studies. After 24 h of stimulation with tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) or IL-6, real-time RT-PCR and ELISA experiments were performed to evaluate the effect of these cytokines on the production of HBD-2. In contrast to healthy cartilage, HBD-2 expression was identified in most of the OA samples examined (eight of ten). Cytokines that are potentially involved in the pathogenesis of OA, namely TNF-alpha, IL-1, and IL-6, were transcriptional inducers of HBD-2 in cultured chondrocytes and cartilage explants in vitro, as measured by real-time RT-PCR and ELISA. These results illustrate the induction of HBD-2 in osteoarthritic cartilage and suggest that it is a further factor in the pathogenesis of OA. However, further studies are required to elucidate the role played by HBD-2 in osteoarthritic cartilage.

This paper presents an experimental technique and experimental results of heat transfer measurements in microtubes of 250 and 500 μm diameter. The data obtained with single-phase argon show no physical difference of heat transfer mechanisms between micro- and macrotubes. The enhancement of heat transfer compared to conventional correlations is explained with the increased influence of roughness, and modeled with a new relative roughness parameter. In two-phase flow, nucleate boiling heat transfer coefficients are lower than in macrotubes. An extension of the diameter dependence in the VDI Warmeatlas correlation is proposed, and the conditions for stable flow-boiling are discussed.

This article presents the development of a miniaturized cryogenic fluid circuit for distributed cooling of low-temperature tracking detectors in high-energy physics (HEP). The heart of the circuit is a prototype cryogenic micropump. This volumetric pump is compatible with cooling powers of about 10-100 W, and capable of producing pressure heads of up to around 0.3 MPa. Besides detector and electronics cooling in HEP, potential applications are found in the field of superconductor technology.

RD39 collaboration develops new detector techniques for particle trackers, which have to withstand fluences up to 10 16 cm −2 of high-energy particles. The work focuses on the optimization of silicon detectors and their readout electronics while keeping the temperature as a free parameter. Our results so far suggest that the best operating temperature is around 130 K . We shall also describe in this paper how the current-injected mode of operation reduces the polarization of the bulk silicon at low temperatures, and how the engineering and materials problems related with vacuum and low temperature can be solved.

Tumor cell metaphases of classical Hodgkin's lymphoma (cHL) characteristically display highly rearranged karyotypes with chromosome numbers in the hyperploid range and marked intraclonal variability. The causes of this cytogenetic pattern remain largely unknown. An unusual type of chromosomal abnormality coined as segmental chromosomal aberration (SCA) has been recurrently observed in HL cell lines and was suggested to be associated with ribosomal DNA (rDNA) rearrangements. Moreover, centrosome abnormalities provoking deficient chromosome segregation have been reported in many solid tumors and also in cHL cell lines. Whether SCA, rDNA rearrangements or centrosome abnormalities also occur in primary cHL is not yet known. Thus, we performed extensive molecular cytogenetic and immunohistological studies in two cHL cases. Both cases presented SCA associated with genomic gains of the REL and JAK2 loci, respectively. The SCA involving JAK2 was associated with rDNA rearrangements. The absolute centrosome size of HRS cells in both cases was significantly larger than in non-HRS cells, but the relative centrosome size of HRS cells corrected for nuclear size was in the same range as that of the non-neoplastic cells. These findings demonstrate that the various mechanisms associated with chromosomal instability warrant a more detailed characterization in cHL.

The CERN RD39 Collaboration studies the possibility to extend the detector lifetime in a hostile radiation environment by operating them at low temperatures. The outstanding illustration is the Lazarus effect, which showed a broad operational temperature range around 130 K for neutron irradiated silicon detectors.

Though several studies have proved the radiation tolerance of silicon detectors at cryogenic temperatures, following room temperature irradiation, no previous investigation has studied the behaviour of detectors irradiated ‘‘in situ’’ at low temperatures. In this work, effects of irradiation of 450 GeV protons at 83 K will be presented, showing that after a dose of 1.2 � 10 15 pc m � 2 a charge collection efficiency (CCE) of 55% is reached at 200 V before the annealing. The same results were found at the end of the irradiation, after the sample has spent more then one year at room temperature. This shows that the CCE recovery by low temperature operation is not affected by the temperature of irradiation and by the reverse annealing. r 2002 Elsevier Science B.V. All rights reserved.

Background Diarrhea occurs frequently among persons with the acquired immunodeficiency syndrome, but the cause often remains unknown. We used a group of diagnostic assays to determine which viruses were etiologic agents of diarrhea in a group of persons infected with the human immunodeficiency virus (HIV). Methods Stool and serum specimens were obtained from HIV-infected patients enrolled in a longitudinal study in Atlanta. Fecal specimens from patients with diarrhea and from control patients without diarrhea were screened by electron microscopy, polyacrylamide-gel electrophoresis, and enzyme immunoassays for rotaviruses, enteric adenoviruses, caliciviruses, picobirnaviruses, and astroviruses. Paired serum samples were tested for antibody responses to Norwalk virus and picobirnavirus. Results Viruses were detected in 35 percent of 109 fecal specimens from patients with diarrhea but in only 12 percent of 113 specimens from those without diarrhea (P

Two prospective studies on the occurrence of human viruses in samples of coastal & river origin have been undertaken since September 1989. Viruses were detected using concentration methods & cell culture techniques. Water samples (100L) were reduced to 1L using hollow fibre ultrafiltration and then treated with PEG. Sewage and sediment samples were treated with PEG only. Over a two year period, viruses were detected in 24/202 (12%) of water samples and 29/60 effluents from the river system. Coastal waters have been contaminated by cliff edge discharge of sewage for at least the last 70 years. Recently, deepwater ocean outfalls have been installed to discharge effluent some 3 km away from the coast. Prior to the installation of deepwater ocean outfalls viruses were detected in 28% of water samples compared to 9% post installation. In sediment samples viruses were isolated in 87/260 (34%) samples, the discharge via the new outfalls having no effect on the isolation rate. The data points to long term survival of viruses sediments and/or contamination from other sources such as storm water discharge: 10-25% of storm water drains were also found to be positive for viruses. The viruses isolated were enteroviruses, adenoviruses & reoviruses. Although viruses were consistently isolated with some seasonal trends, comparisons between the detection of viruses in clinical and environmental samples over this two year period were inconclusive.

A low-mass cryogenic cooling technique for silicon sensor modules has been developed in the framework of the RD39 Collaboration at CERN. A prototype low-mass beam tracker cryostat has been designed, constructed and tested for applications in fixed target experiments. We shall report here briefly the main features and results of the system.

The cryogenic transfer line for KATRIN connects 3 large superconducting magnet systems in the Tritium Laboratory Karlsruhe (TLK) with a He refrigerator installed in an external machine building. The vacuum‐insulated transfer line comprises 1 N2 and 5 He process lines that are surrounded by a LN2‐cooled radiation shield. Covering a distance of 40 m, the transfer line includes 4 valve boxes, 1 T‐junction, 1 vertical and 3 horizontal line sections. After the introductory system description, an overview is given on project coordination and quality assurance, together with results of leak testing during pre‐acceptance and commissioning. The method and results of thermal loss measurements in the He system are explained, reaching an accuracy of ±30% with standard process instrumentation. Potential improvements in the MLI insulation scheme are revealed, based on both the measurements and theoretical considerations. The experimental results are finally compared with data of large cryogenic transfer systems.

A study was conducted to investigate the use of an advanced membrane microfiltration system to disinfect and clarify secondary and primary treated sewage. The membrane microfiltration system tested incorporated a patented gas backwashing technique which significantly reduces fouling. A comprehensive microbiological testing program established that all indicator bacteria and viruses were removed by this system. Testing for chemical quality showed significant reductions in BOD, suspended solids, turbidity, phosphorus, oil/grease and heavy metals. Consistent filtration rates over several months were achieved without significant biological fouling. The study conclusively showed the capability of the microfiltration system to disinfect and clarify treated sewage.

The KATRIN experiment will measure the mass of electron antineutrinos with a sensitivity of 0.2 eV/c2 by the precise measurement of the tritium β spectrum. A key component is the Windowless Gaseous Tritium Source (WGTS), which will deliver 1011 β decay electrons per second. The WGTS consists in its centre of a 10 m long beam tube operated at 30 K, which is surrounded by a series of superconducting solenoids. Molecular tritium is injected through a central injection chamber and pumped at either beam tube end. The tritium density profile must have a stability of 10−3 to limit systematic errors, yielding stringent requirements on the beam tube temperature homogeneity (±30 mK) and stability (±30 mK/h). This shall be achieved with a design, where the thermal radiation heat from the vacuum pumps is almost entirely absorbed by LN2 and He coolers on the pump ports, while the beam tube temperature is stabilized with saturated Ne in a thermosiphon. Starting from a functional description, we explain the cryogenic de...

The CERN RD39 Collaboration is developing super-radiation hard cryogenic Si detectors for applications in experiments of the LHC and the future LHC Upgrade. Radiation hardness up to the fluence of 10 16 n eq /cm 2 is required in the future experiments. Significant improvement in the radiation hardness of silicon sensors has taken place during the past years. However, 10 16 n eq /cm 2 is well beyond the radiation tolerance of even the most advanced semiconductor detectors made by commonly adopted technologies. Furthermore, at this radiation load the carrier trapping will limit the charge collection depth to the range of 20–30 μm regardless of the depletion depth. The key of our approach is freezing the trapping that affects Charge Collection Efficiency (CCE).

The recovery of the charge collection efficiency (CCE) at low temperatures, the so-called ”Lazarus effect”, was studied in Si detectors irradiated by fast reactor neutrons, by protons of medium and high energy, by pions and by gamma-rays. The experimental results show that the Lazarus effect is observed: (a) after all types of irradiation; (b) before and after space charge sign inversion; (c) only in detectors that are biased at voltages resulting in partial depletion at room temperature. The experimental temperature dependence of the CCE for proton-irradiated detectors shows non-monotonic behaviour with a maximum at a temperature defined as the CCE recovery temperature. The model of the effect for proton-irradiated detectors agrees well with that developed earlier for detectors irradiated by neutrons. The same midgap acceptor-type and donor-type levels are responsible for the Lazarus effect in detectors irradiated by neutrons and by protons. A new, abnormal “zigzag”-shaped temperature dependence of the CCE was observed for detectors irradiated by all particles (neutrons, protons and pions) and by an ultra-high dose of γ-rays, when operating at low bias voltages. This effect is explained in the framework of the double-peak electric field distribution model for heavily irradiated detectors. The redistribution of the space charge region depth between the depleted regions adjacent to p+ and n+ contacts is responsible for the “zigzag”- shaped curves. It is shown that the CCE recovery temperature increases with reverse bias in all detectors, regardless of the type of radiation.

We shall review test results which show that silicon detectors can withstand at 130 K temperature a fluence of 2×10 15 cm –2 of 1 MeV neutrons, which is about 10 times higher than the fluence tolerated by the best detectors operated close to room temperature. The tests were carried out on simple pad devices and on microstrip detectors of different types. The devices were irradiated at room temperature using reactor neutrons, and in situ at low temperatures using high-energy protons and lead ions. No substantial difference was observed between samples irradiated at low temperature and those irradiated at room temperature, after beneficial annealing. The design of low-mass modules for low-temperature trackers is discussed briefly, together with the cooling circuits for small and large systems.

In June 1991, a large outbreak of acute nonbacterial gastroenteritis occurred among students and teachers at 10 primary and 4 junior high schools in Katano City, Osaka, Japan. The outbreak affected > 4700 persons, lasted 5 days, and was believed to have been linked to contaminated food from a common supplier. Astrovirus, identified as the etiologic agent, was detected by direct electron microscopy in 10 of 38 fecal samples obtained from patients with diarrhea. Detection was confirmed by solid-phase immune electron microscopy (IEM), EIA, reverse transcription-polymerase chain reaction, and virus isolation in CaCo-2 cells. Several patients who had astrovirus in their stool also demonstrated a significant antibody response to a reference strain of astrovirus by IEM and EIA and to their own isolate by IEM. Astrovirus can be an important agent of epidemic acute nonbacterial gastroenteritis in school-aged children and adults in Japan.

Diarrhea occurs frequently among persons with the acquired immunodeficiency syndrome, but the cause often remains unknown. We used a group of diagnostic assays to determine which viruses were etiologic agents of diarrhea in a group of persons infected with the human immunodeficiency virus (HIV).Stool and serum specimens were obtained from HIV-infected patients enrolled in a longitudinal study in Atlanta. Fecal specimens from patients with diarrhea and from control patients without diarrhea were screened by electron microscopy, polyacrylamide-gel electrophoresis, and enzyme immunoassays for rotaviruses, enteric adenoviruses, caliciviruses, picobirnaviruses, and astroviruses. Paired serum samples were tested for antibody responses to Norwalk virus and picobirnavirus.Viruses were detected in 35 percent of 109 fecal specimens from patients with diarrhea but in only 12 percent of 113 specimens from those without diarrhea (P0.001). Specimens from patients with diarrhea were more likely than those from patients without diarrhea to have astrovirus (12 percent vs. 2 percent, P = 0.003); picobirnavirus (9 percent vs. 2 percent, P = 0.017); caliciviruses, including small round structured viruses (6 percent vs. 1 percent, P = 0.062); and adenoviruses (9 percent vs. 3 percent, P = 0.047). They were also more likely to have a mixed viral infection (6 percent vs. 0 percent, P = 0.006). With the use of polyacrylamide-gel electrophoresis to analyze concentrated RNA extracts from stool, picobirnavirus was detected in fecal specimens from 6 of the 65 patients with diarrhea and was associated with prolonged viral shedding and chronic diarrhea. No rotaviruses, enteric adenoviruses, or instances of seroconversion to positivity for Norwalk virus were observed.Novel enteric viruses such as astrovirus and picobirnavirus may be more important etiologic agents of diarrhea in HIV-infected patients than previously recognized and may be more common than either bacterial or parasitic enteropathogens.

The evolution-optimized leaves of Colocasia esculenta (taro) and Nelumbo nucifera (lotus) are the best optimized self-cleaning surfaces known to date. Using an atomic force microscope device equipped with a piezodriven sample stage which enables a z-range of 100 μm we measured the surface morphology of dried and undried leaves of Colocasia esculenta. Thermodynamic calculations were done to investigate the interaction strength of a water droplet with the surfaces of the morphology shown in the images. The results show that the hierarchical structure produces a stable superhydrophobic state with optimal self-cleaning properties.

A prospective study of 74 adults with acute diarrhoea was carried out in Sydney in 1984-1985 to determine the infective agents that were involved and their relationship to clinical, epidemiological and laboratory features. Thirty-four potential pathogens were identified in 32 (43.2%) patients. These included, in order of frequency: Campylobacter spp., rotavirus, Clostridium difficile, Salmonella enteritidis, Aeromonas hydrophila, Vibrio parahaemolyticus, adenovirus, a small round virus and Giardia lamblia. A seasonal trend was noted; the majority of Campylobacter isolations occurred in summer. The patients with Cl. difficile infection formed a distinct group, and experienced a subacute onset of diarrhoea after antibiotic administration, with few systemic symptoms. Except in these patients, the clinical and epidemiological features, together with results of faecal microscopy, were not a reliable predictor of the nature of the pathogens that were identified. While most patients with diarrhoea can be treated supportively, stool culture is an important procedure in patients with severe or protracted illness when specific antimicrobial therapy is contemplated.

An outbreak of acute gastroenteritis occurred in a primary school southwest of Sydney in August, 1977. Two hundred and eight pupils and nine teachers were affected over a one-month period. Electron microscopy revealed parvovirus-like particles in faecal extracts of 14 of 23 persons tested during the acute phase of illness. The virus was still present in the faeces of four individuals six weeks later. The appearance of specific antibodies was demonstrated by immune electron microscopy in five persons. No other cause for the outbreak could be found despite exhaustive investigations.

A pilot study was conducted between February and April, 1989, on the occurrence of sewage-derived viruses and bacteria in the beach and nearshore waters off Bondi, Sydney. Enteroviruses were isolated from 41% of a total of 66 sewage, sea-water, grease and sediment samples. Poliovirus vaccine strains accounted for 78% of the isolates. Adenoviruses were isolated four times and coxsackievirus B was isolated twice in samples that were collected away from the bathing area. Rotavirus and hepatitis A virus were not detected. The number of faecal coliforms, faecal streptococci, Aeromonas hydrophila and Clostridium perfringens in the sewage ranged from 10(4) to 10(7) cfu/100 mL. An initial reduction of 10(2)-10(3) in bacterial counts was observed in the plume (the effluent's initial dilution zone) and a further reduction of 10(2)-10(4) in counts in samples that were collected away from the plume. Salmonella spp. were detected in one-third of the samples and low numbers of Campylobacter jejuni were found in the sewage and plume. Salmonella serotypes that were associated with the sewage and plume were distinct from those in the stormwater and beachwater, indicating that stormwater may be an important source of pollution on Bondi beach.

At least 2000 persons were involved in an Australia-wide outbreak of oyster-associated food poisoning in June and July, 1978. At the time, this episode presented a major health risk to the community as a whole and has subsequently posed a serious economic problem for the oyster farming and distributing industry. Although bacteriological investigations indicated some batches of oysters were contaminated by sewage, no bacterial cause could be established. The causative organism was shown to be Norwalk virus, a known cause of acute non-bacterial gastroenteritis. This virus was found in 39% of faecal specimens examined by electron microscopy and an antibody response was demonstrated by immune electron microscopy in 75% of paired sera tested. Norwalk virus has not been identified previously outside the United States of America and has not been linked to food-borne gastroenteritis before. Purification of oysters and other measures have been instituted to prevent a recurrence of the outbreak.

Following the widespread outbreaks of oyster-associated gastroenteritis which occurred throughout Australia in 1978, several programmes were introduced to minimise the occurrence of further outbreaks. One programme included the depuration (purification) of oysters and the use of human volunteers to test-consume samples from batches of depurated oysters before their sale to the public. Oysters from the Georges River and Brisbane Waters were test-consumed from December, 1978, to August, 1979. None of the volunteers was ill after consuming Brisbane Waters oysters but 52 reported ill after eating Georges River oysters. The predominant symptoms were nausea, vomiting and diarrhoea with an average incubation period of 42 hours. Recovery was usually complete in 36-48 hours. Of the 52 illnesses reported 31 (60%) occurred in two particular weeks ending July 1st and 22nd when rates of 18.3% and 7.8% were reported. The average illness rate for the remainder of the period under study was only 1%. Norwalk virus was found in 8 of 25 (32%) stools, and antibody increases demonstrated in seven of ten paired sera, giving an overall diagnostic rate for Norwalk infection of 37.0% for these two peak periods. Heavy rain preceded these two weeks in which the illnesses occurred. No evidence of Norwalk infection was found at any other time. These studies confirmed the epidemiological findings of the major outbreak of gastroenteritis in 1978, and showed that only Georges River oysters caused Norwalk virus infections and that depuration as carried out in 1979 was not entirely satisfactory.

Following widespread outbreaks of oyster-associated gastroenteritis in Australia during 1978 in which Norwalk virus was implicated as the causative agent, collaborative studies were undertaken between laboratories in Australia and the United States to confirm the etiology. Immune electron microscopy (IEM) techniques were used in Australia and radioimmunoassay (RIA) methods in the United States. Norwalk virus was detected by IEM in seven of 15 faecal samples, and four were positive by RIA. A much better correlation was found with antibody determinations. Both methods demonstrated significant increases in antibody to Norwalk virus in 22 of 30 sets (73%) of "acute" and "convalescent" sera, confirming that Norwalk virus was responsible for the majority of cases. It is significant that the RIA serology was determined using Norwalk antigen originating in the United States and the IEM serology was determined using 27--30-nm particles originating in Australia.

Summary: Hepatitis A outbreak in a residential school. C. R. Boughton, R. A. Hawkes, N. I. Lehmann and G. S. Grohmann, Aust. N.Z. J. Med., 1980, 10, pp. 4–6. Outbreaks of hepatitis A occurred sequentially in two wards for children in a residential institution for the mentally retarded in Sydney. Twenty-six of 47 children were initially susceptible to hepatitis A. In the first ward affected, 77 of 13 susceptible children (85%), and in the second ward, four of 13 susceptible (31%), were infected. Of the 15 showing serological evidence of infection, five (33%) were clinically jaundiced.