Search

Body temperature is an important physiological parameter in many studies of laboratory mice. Continuous assessment of body temperature has traditionally required surgical implantation of a telemeter, but this invasive procedure adversely impacts animal welfare. Near-infrared thermography provides a non-invasive alternative by continuously measuring the highest temperature on the outside of the body (Tskin), but the reliability of these recordings as a proxy for continuous core body temperature (Tcore) measurements has not been assessed. Here, Tcore (30 s resolution) and Tskin (1 s resolution) were continuously measured for three days in mice exposed to ad libitum and restricted feeding conditions. We subsequently developed an algorithm that optimised the reliability of a Tskin-derived estimate of Tcore. This identified the average of the maximum Tskin per minute over a 30-min interval as the optimal way to estimate Tcore. Subsequent validation analyses did however demonstrate that this Tskin-derived proxy did not provide a reliable estimate of the absolute Tcore due to the high between-animal variability in the relationship between Tskin and Tcore. Conversely, validation showed that Tskin-derived estimates of Tcore reliably describe temporal patterns in physiologically-relevant Tcore changes and provide an excellent measure to perform within-animal comparisons of relative changes in Tcore.

From July to September 1993 in the intensive care unit of the Royal Victoria Hospital there were 10 cases of pneumonia associated with sputum culture of Pseudomonas aeruginosa. The isolates had an identical biotype and pyocine typing profile. The same strain of P. aeruginosa was recovered from the sink plug-hole in two rooms, and the tap handles and ventilator tubing in a third room. All strains were retrospectively typed by the random amplification of polymorphic DNA (RAPD) method using a 26-mer oligonucleotide primer, and were identical in profile. Recommendations to medical and nursing staff included secretion isolation precautions, terminal disinfection after patient discharge, use of disposable vinyl gloves by hospital staff for all body substance contacts, thorough handwashing with 4% chlorhexidine gluconate before and after dealing with all patient contacts, and prompt, appropriate antibiotic treatment for P. aeruginosa pneumonia. RAPD is a simple and effective method to determine the relatedness of P. aeruginosa isolates, and typing results are available within a single working day; thus dramatically increasing its clinical relevance over existing molecular methods.

Dynamic mechanical thermal analysis (DMTA) of virgin TR-55 silicone rubber specimens was conducted. Two dynamic temperature sweep tests, 25 to -100 C and 25 to -70 to 0 C (ramp rate = 1 C/min), were conducted at a frequency of 6.28 rad/s (1 Hz) using a torsion rectangular test geometry. A strain of 0.1% was used, which was near the upper limit of the linear viscoelastic region of the material based on an initial dynamic strain sweep test. Storage (G{prime}) and loss (G{double_prime}) moduli, the ratio G{double_prime}/G{prime} (tan {delta}), and the coefficient of linear thermal expansion ({alpha}) were determined as a function of temperature. Crystallization occurred between -40 and -60 C, with G{prime} increasing from {approx}6 x 10{sup 6} to {approx}4 x 10{sup 8} Pa. The value of {alpha} was fairly constant before ({approx}4 x 10{sup -4} mm/mm- C) and after ({approx}3 x 10{sup -4} mm/mm- C) the transition, and peaked during the transition ({approx}3 x 10{sup -3} mm/mm- C). Melting occurred around -30 C upon heating.

Dynamic mechanical thermal analysis (DMTA) of virgin TR-55 silicone rubber specimens was conducted. Dynamic frequency/temperature sweep tests were conducted over the ranges 0.1-100 rad/s and 30-100 C using a parallel plate test geometry. A strain of 0.2% was used, which was near the upper limit of the linear viscoelastic region of the material based on initial dynamic strain sweep tests. Master curves of G{prime} and G{double_prime} as a function of frequency were generated using time-temperature superposition (horizontal shift with initial vertical correction). The activation energy calculated from an Arrhenius fit to the horizontal shift factors was 178-355 kJ/mol. The calculated percent load retention at {approx}50 years was 61-68%.

TR-55 rubber specimens were previously subjected to an aging process consisting of the application of a tensile strain of approximately 67%, 100%, 133%, or 167% elongation for 4, 8, 12, or 16 h at either 250 C or room temperature. Control specimens at the same temperatures/durations were not subjected to tensile strain. The specimens were allowed to recover at room temperature without external stimuli for over 100 days before tensile testing. A single dog bone was cut from each specimen and a stress-strain curve was obtained. The elastic modulus of each specimen was calculated. Specimens aged under tensile strain exhibited rubber-like behavior dependent on the aging elongation and duration. This behavior was not evident in the unstrained controls. For the unstrained controls, exposure to 250 C resulted in an increase in modulus relative to the unheated material independent of the heating duration. The tensile strain applied during the aging process caused a reduction in modulus relative to the controls; lower moduli were observed for the shorter aging durations. Slippage of the specimens in the grips prevented determination of ultimate strength, as all specimens either slipped completely out of the grip before failure or failed at the original grip edge aftermore » slipping.« less

The process of film blowing was considered in an attempt to obtain biaxial orientation and properties for two thermotropic copolyesters: p-hydroxybenzoic acid/polyethylene terephthalate (HBA/PET) and p-hydroxybenzoic acid/6-hydroxy-2-naphthoic acid (HBA/HNA). Tensile properties of the blown film were exceptional for these materials: tensile strengths of 300 to 400 MPa and moduli of13 GPa were observed in the axial direction, for example. This result if believed due to the absence of a skin-core texture in which the core often remains relatively unoriented. Despite some improvement in the transverse direction with increasing blow up ratio (B UR), properties did not exceed 20 to 25% of those in the machine direction. Wide angle x-ray scattering measurements confirmed the predominantly axial orientation in the films, which was believed to be generated in the annular die gap and not significantly disrupted during the subsequent blowing process. The properties and morphology of the blown film were compared to those ofuniaxially drawn films. It was found that in the machine direction the properties were similar, while significantly higher properties were obtained in the transverse direction for the blown film.

Three independent measurements have been used to investigate combustion within a single cylinder four-stroke research engine operating at low load. THIN FILM GAUGES Heat transfer between the working fluid and the combustion chamber in an internal combustion engine is one of the most important parameters for cycle simulation and analysis. Heat transfer influences the in-cylinder pressure and temperature levels, engine efficiency and exhaust emissions. Heat transfer is determined using platinum thin film resistance thermometers exposed to the combustion gases. These give a frequency response of greater than 100kHz; hence can track heat transfer rate changes on the piston and cylinder head surfaces adequately. The thin film gauges overcome the problems of low bandwidths and large uncertainties associated with thermocouples. FIBRE OPTIC INSTRUMENTATION Combustion is a highly complex process where the mechanism of fuel oxidation causes many different chemical species to emit light on specific spectral lines; therefore, from a measured emission spectrum it is possible to infer the chemical species present. Measurements of the spectral content (300 to 850 nm) of the light intensities within the combustion chamber are presented. HIGH SPEED VIDEO A high frame-rate colour video camera is used to record a series of images of the firing cycle with a high spatial and temporal resolution through a cylinder head modified for optical access. The video data powerfully illustrates the complex and variable nature of the combustion process. The three techniques form part of a Data Fusion study researching the application of data processing techniques in complex multidimensional areas such as combustion. Copyright © 2002 Society of Automotive Engineers, Inc.

Three independent measurements have been used to investigate combustion within a single cylinder four-stroke research engine operating at low load. THIN FILM GAUGES - Heat transfer is determined using platinum thin film resistance thermometers exposed to the combustion gases. These give a frequency response of greater than 100kHz; hence can track heat transfer rate changes on the piston and cylinder head surfaces adequately. The thin film gauges overcome the problems of low bandwidths and large uncertainties associated with thermocouples. FIBRE OPTIC INSTRUMENTATION - Combustion is a highly complex process where the mechanism of fuel oxidation causes many different chemical species to emit light on specific spectral lines; therefore, from a measured emission spectrum it is possible to infer the chemical species present Measurements of the spectral content (300 to 850 nm) of the light intensities within the combustion chamber are presented. HIGH SPEED VIDEO - A 500fps colour video camera was used to record a series of images of the firing cycle with a high spatial and temporal resolution through a cylinder head modified for optical access.. The three techniques form part of a Data Fusion study researching the application of data processing techniques in complex multidimensional areas such as combustion.

Qualitative comparisons are made between Particle Image Velocimetry data and Computational Fluid Dynamics predictions for the flow around two adjacent rotating cylinders. For this novel flow configuration, the cylinders rotate in opposite directions with their outer surfaces in contact. Steady state sets are carried out of the following rotational Reynolds numbers, Re(phi ) equals 75, 966 and 1470. Also, test are carried out where the cylinders are suddenly started. The flow exhibits a relatively powerful jet which is ejected between the cylinders. Under transient conditions a complex flow phenomenon is observed. A numerical stochastic Lagrangian particle transport technique for studying the movement of seeding particles relative to fluids is used. Under steady conditions agreement is found between measurements and predictions.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

An outbreak of gastroenteritis arose in people who attended a charity barbecue at a hotel in a rural area of Northern Ireland in July 1995. About 120 people attended the barbecue, 98 of whom were identified. Fifty-one of them and seven members of hotel staff met the case definition. An epidemiological investigation showed that illness was significantly associated with eating foods containing mayonnaise that had been prepared using raw shell eggs and stored at too high a temperature. Salmonella enteritidis phage type 4 was cultured from 17 out of 24 faecal specimens received from people who attended the barbecue and in 17 out of 34 faecal specimens from staff, including all seven staff cases. The primary source of infection was not identified despite thorough investigation. This paper highlights the value of administering questionnaires by telephone when investigating community outbreaks of infection in rural areas, the important role of general practitioners in the identification of community outbreaks, and the need to periodically reiterate public health messages, in particular for food handlers and caterers.

A prospective survey was carried out in Northern Ireland between February and August 1994 to assess the current levels of salmonella in retail chickens, and to determine whether contamination rates differed between chickens sold in supermarkets and by butchers. One hundred and forty chilled and frozen raw chickens were sampled from retail display and examined for the presence of salmonella using an approved method. Contamination was commoner in chickens that were chilled, sold from smaller premises, and reared or slaughtered outside Northern Ireland. Salmonella enteritidis phage type 4 was the most commonly isolated type. The contamination rate of about 7% is considerably lower than in Great Britain and this may partially explain the lower rate of human salmonella infections in Northern Ireland. This finding supports the recommendations made in the Advisory Committee on the Microbiological Standards of Food's report on poultry meat, since many of the improvements proposed are already in operation in areas of the Northern Ireland poultry industry.

A multi-centre collaborative study was carried out to compare, established sub-typing techniques for C. jejuni based upon phenotypic markers namely serotype, phagetype and biotype with molecular typing methods such as 16S rRNA RFLP’s, pulsed field gel electrophoresis, RAPD, PCR-RFLP and multilocus enzyme electrophoresis, for their relative discriminatory sensitivities and specificities.

We investigated the use of [18F]fluoro-2-deoxyglucose (FDG) PET scanning for assessment of skeletal muscle viability in patients with peripheral vascular disease and in patients following free-flap skeletal muscle transfer for closure of open wounds.We obtained 32 FDG-PET scans from 30 patients, either at the time of admission for peripheral vascular disease (n = 16) or between 1 and 15 days after surgery for skeletal muscle transfer (n = 16). Ratios between injured and contralateral limb FDG tracer activity uptake were correlated with clinical outcome at 1 mo to 3 yr follow-up.Viable muscle uptake ratios ranged from 0.47 to 7.88 (mean: 2.26 +/- 1.81; n = 26), while nonviable muscle uptake ratios ranged from 0.12 to 0.46 (mean: 0.27 +/- 0.12; n = 6; p0.02). After skeletal muscle transfer, two patients with viable tissue, as documented by PET, required amputation due to osteomyelitis, and one patient with peripheral vascular disease who showed viable tissue by PET required amputation 3 mo after the PET scan because of recurrent ulcers.FDG-PET scanning can determine skeletal muscle viability in patients with peripheral vascular disease and in patients following free-flap transfer.

A review of the incidence of waterborne disease in Scotland from 1945 to 1987 has been undertaken in conjunction with the Communicable Diseases (Scotland) Unit and the Scottish Home and Health Department. Primarily, these relate to contamination of private and public supplies by microbiological and chemical agents, but incidents in which water such as river water was ingested deliberately or accidentally were included. Water-related infections such as legionellosis and leptospirosis which are acquired by non-alimentary routes have been excluded. During the period of the review there were 57 outbreaks of water-borne disease comprising of over 15,305 cases of illness. A total of 18 outbreaks occurred in public supplies and 21 in private supplies. Microbiological contamination gave rise to the greatest number of cases of water-borne disease which were caused by viral gastroenteritis and shigellosis followed by outbreaks of gastroenteritis of unknown aetiology. The highest number of outbreaks were due to chemical poisoning,caused mainly by lead and copper, followed by outbreaks of gastroenteritis of unknown aetiology. The type of deficiency giving rise to incidents of waterborne disease were described for private and public water supplies. In public supplies the need for hygenic storage of water in distribution and effective catchment control practices in conjunction with adequate water treatment facilities is emphasised. In private supplies the need to, at minimum, apply rudimentary disinfection to untreated source water is highlighted by the large numbers of people who have been affected by water-borne disease.

A method is proposed for the simultaneous staining of neutral and acidic, periodate reactive and nonperiodate reactive mucosubstances, glycogen and keratin in paraffin sections. Briefly, sections are stained by the Alcian blue (pH 2.5)-PAS method, followed by a peroxidase-antiperoxidase imiminohistochemical stain for keratin. The proposed method modifies an existing method, and expands the range of polysaccharides and mucosubstances which may be demonstrated. The proposed method is easily performed within a single working day and promises to be of value in surgical pathology as well as in studies of bronchial carcinogenesis.

SUMMARYA bacteriological study was carried out on the first Leisure Centre swimming pools in the United Kingdom to be disinfected with ozone/chlorine. Results suggested that a free chlorine concentration of approximately 0·8 mg/l was necessary to maintain the pools in a bacteriologically satisfactory condition. This amount of free chlorine was similar to that required when the pool was disinfected with chlorine alone. However, the associated amount of combined chlorine was much lower when disinfection was by ozone/chlorine and this gave more acceptable bathing conditions. Implications for the management of pools disinfected by this method are discussed.

Plasma concentrations of copper and zinc and leucocyte concentrations of zinc were measured in mothers during later pregnancy, at delivery, and 8-10 weeks after birth, and plasma concentrations of copper and zinc were measured in their infants at delivery and 8-10 weeks after birth. The 145 infants were either breast fed or fed one of two milk formulas supplying copper at different concentrations. None of the infants achieved the minimum copper intakes recommended by the World Health Organisation (WHO). At 2 months of age there were no major differences in growth or health detected in infants fed the different copper intakes. Infant birth weight correlated well with the ratio of maternal venous plasma zinc:maternal leucocyte zinc at delivery. Maternal venous plasma copper and zinc concentrations at birth correlated with umbilical venous plasma copper and zinc concentrations. Infants fed the higher copper content formulas had a low mean plasma zinc concentration without a significant increase in the mean plasma copper concentration. The present WHO recommendations regarding minimum copper intakes for infants fed formulas cannot be achieved with currently available formulas and are probably wrong.

Five cases of colonic retention of barium with severe constipation occurring in elderly patients after a barium-meal examination were seen in a two-year period and it is suggested that this complication may be unrecognized. Lactulose 50% (Duphalac) was an effective agent in inducing bowel evacuation in these patients, who were resistant to more generally used methods.

An investigation was undertaken to assess the present importance of leptospiral infections in Northern Ireland, and in particular to look for evidence of infection by leptospiral serotypes other than L. icterohaemorrhagiae and L. canicola. Blood samples from 335 patients, sent to the laboratory for a variety of tests, were examined. After initial screening with five groups of pooled antigens, tests for leptospiral agglutinins were completed with formolized antigens prepared from 13 different serotypes. In seven patients a diagnosis of acute leptospirosis was made while nine others showed serological evidence of previous leptospiral infection. Attempts to isolate leptospirae by culture from 29 blood samples were unsuccessful. The serological results indicate that two additional leptospiral serotypes, namely L. ballum and L. bratislava , are causing human infection in Northern Ireland, and presumably also in other parts of the British Isles. Some clinical and epidemiological features associated with different types of leptospiral infection are described. It is stressed that leptospirosis is essentially a febrile illness, that meningeal symptoms are common, and that (contrary to popular belief) jaundice is by no means a constant occurrence. The implications of these findings are discussed, with special reference to the diagnosis of leptospiral infections. Laboratory diagnostic procedures are briefly reviewed, and the possible deficiencies of the agglutination test commonly used in Britain are pointed out. Some suggestions are made concerning both clinical and laboratory aspects of diagnosis, and the need for a reliable screening test for all forms of leptospiral infection is emphasized.

The dynamics of a pendulum damper is treated in a more general way than hitherto, all known types being included. A new method of considering the effects of a pendulum damper when fixed at any point in an engine system is developed, showing that its action results in an alteration or displacement of the critical speeds at which the harmonic orders occur. A convenient method is outlined for arriving theoretically at the best design for a pendulum damper, whatever may be its location in the engine system. As a practical illustration, a brief account is given of experimental work which was undertaken to test the behaviour of a well-known engine when a certain pendulum damper was fitted to the flywheel. A further account of a similar application to a six-cylinder engine is also given. Special forms of pendulums, and a note on the estimation of angular amplitudes, are discussed in Appendix I, and a bibliography and a short list of the most important patent specifications relating to pendulum dampers are also included.

Over 12 months serum was collected from 45 inpatients, with acute bronchopulmonary infection, in whose sputum Branhamella catarrhalis predominated, or was the sole pathogen. Serum was examined for IgG against B catarrhalis using an immunofluorescence antibody test. Acute and convalescent sera were compared with sera of age and sex matched controls. The convalescent sera had significantly higher titres than the acute sera which in turn had higher titres than the controls. The findings confirm the role of B catarrhalis as a respiratory pathogen and suggest that patients with chronic pulmonary disease are more prone to infection with this organism than the general population.

All stages of regeneration in hamster tracheal epithelium were studied following a denuding mechanical injury. At 1 h all the cells had sloughed from the wound site leaving a bare and sometimes disrupted basal lamina. Viable cells at the wound margins rapidly changed shape, flattened and migrated to cover the denuded lesion by 12 h. In addition, epithelial cells that remained viable demonstrated sublethal changes that included the rapid discharge of mucous granules from secretory cells, internalization of cilia by ciliated cells and evidence of heterophagy in both cell types. By 24 h a wave of epithelial cell divisions occurred, primarily by secretory cells. This produced a multilayered epidermoid metaplasia that was best developed at 48 h. The metaplastic epithelium was largely composed of cells with both secretory (mucous granules) and epidermoid (tonofilament bundles and numerous desmosomes) characteristics. The peroxidase-antiperoxidase (PAP) method demonstrated a few keratin-positive cells in the wound as early as 12 h post-wounding and keratin was demonstrated in more cells by 24 h. All cells in the metaplastic wound epithelium were keratin-positive by 48 h. Following 48 h some of the most superficial keratinized cells sloughed from the epithelium and the keratin content of the remaining cells began to decline. At 72 h pre-ciliated and pre-secretory cells were seen in the wound. Pre-ciliated cells were characterized by an abundant electron-lucent cytoplasm, large pale nucleus, filiform apical microvilli and evidence of ciliogenesis, similar to that seen during fetal development. Pre-ciliated cells often contained apical mucous granules, apparently carried over from the parent secretory cells. With the appearance of these columnar cells the normal mucociliary morphology was restored in small wounds by 120 h, but some persistent epidermoid metaplasia remained in the large wounds through 168 h post-wounding. These data provide further evidence for the important role of secretory cells in the histogenesis of epidermoid metaplasia and the regeneration of normal morphology following injury. The implications of these findings in understanding the histogenesis of other lesions in the tracheo-bronchial epithelium are discussed.