Search

IntroductionHealth professionals working in the dental environment are potentially at risk of noise-induced hearing loss (NIHL) due to the use of clinical and laboratory equipment. Workplaces engaging in the practice of dentistry within the UK are subject to legislation from the Control of Noise at Work (CNW) regulations 2005. Clinicians working in the military are at further increased risk of NIHL due to exposure from additional risk factors such as rifles or aircraft engines. To our knowledge, no authors have previously studied the noise levels experienced in a military dental setting or compared noise levels in a typical dental practice with current UK legislation.MethodMeasurements of noise levels experienced by a dentist, dental nurse and dental hygienist during a standard conservation procedure were assessed using wearable noise dose-badges. Furthermore, noise levels within a dental technician’s work space were also assessed. Noise levels produced by representative clinical and laboratory equipment were assessed and compared with CNW legislation.ResultsThe highest level for clinical equipment was produced by the suction apparatus while aspirating up a cup of water at 76 dB. For laboratory equipment, the lower exposure action value (LEAV) of 80 dB would be exceeded in 2.1 hours’ use of the trimmer, 3.6 hours’ use of the vibrating table and 9 min use of the airline.ConclusionsNoise levels experienced by clinicians within the dental surgery were well below the legislative LEAV thresholds for both peak and continuous noise. However, noise levels produced by laboratory equipment were far higher and there is clearly the potential for excessive noise exposure for dental professional in the everyday setting. Dental professionals responsible for dental laboratory settings must be familiar with the CNW regulations and measures put in place that control the inadvertent breach of legislation. Hearing protection must be mandated when using equipment that exceeds the LEAV and an educational programme is required to explain both their correct use and the rationale behind it. Methods of mitigating that risk further require exploration such as alternative methods of completing the tasks performed by the airline or reducing the noise generated by it, such as by reducing the supply pressure or using an alternative nozzle design.

Kelp ecology is heavily biased toward the conspicuous sporophyte stage, whereas understanding of the microscopic gametophyte remains limited. Given that kelp gametophytes are known to grow in/on other species of algae, we sought to determine if species-specific polymerase chain reaction could detect kelp gametophytes in situ from coextracted host DNA. Upon verifying our molecular results, we also assessed distributional patterns of the kelp gametophytes according to site, host species, and vertical placement in the intertidal zone. We sampled Chondrus crispus, Mastocarpus stellatus, and Palmaria palmata (Florideophyceae) at Wallace Cove, New Brunswick, Canada, on 13 September 2016, where kelp sporophytes were abundant, and at an adjacent location without obvious sporophyte presence, L'Etete, on 26 September 2016. Species-specific primers were used to assess the presence of Alaria esculenta and Laminaria digitata DNA from coextracted red algal DNA. We successfully amplified kelp DNA from the host ...

Background Carbapenems are traditionally reserved as the last line of defence for treatment of serious infections with multiresistant Gram-negative bacilli. Reports of Klebsiella pneumoniae carbapenemase (KPC)-producing organisms have been emerging globally, but rare in Australasia to date. We describe an outbreak of KPC-2 producing K. pneumoniae at an Australian hospital. Methods After initial detection in October 2012, a retrospective review of patients with meropenem-resistant K. pneumoniae to June 2012, and ongoing prospective surveillance, was undertaken. Included patients were admitted to the hospital after June 2012 and had meropenem-resistant K. pneumoniae isolated from any site. Available isolates underwent detection of the KPC-2 gene by polymerase chain reaction and molecular typing was performed to determine genetic relatedness between isolates. Point-prevalence screening was performed on selected wards to detect asymptomatic carriage. Infection control procedures were implemented to contain the outbreak. Results Ten cases were identified in the initial cluster. Eight were localised to a single inpatient ward. Point-prevalence screening revealed one extra case. After temporary containment, re-emergence of KPC-producing isolates was observed post October 2013 with 18 further cases identified. Four K. pneumoniae isolates in the 2012 cluster and 16 from the 2013–2014 cluster were referred for further testing. All carried the KPC-2 beta-lactamase gene. The 2012 isolates were genetically similar to the 2014 isolates. Conclusion KPC-2 mediated resistance is an emerging threat in Australia. The re-emergence of KPC despite initial containment emphasises the need for constant vigilance in the microbiology laboratory and ongoing maintenance of infection control and antimicrobial stewardship activity.

Carbapenems are traditionally reserved as the last line of defence for treatment of serious infections with multiresistant Gram-negative bacilli. Reports of Klebsiella pneumoniae carbapenemase (KPC)-producing organisms have been emerging globally, but rare in Australasia to date. We describe an outbreak of KPC-2 producing K. pneumoniae at an Australian hospital.After initial detection in October 2012, a retrospective review of patients with meropenem-resistant K. pneumoniae to June 2012, and ongoing prospective surveillance, was undertaken. Included patients were admitted to the hospital after June 2012 and had meropenem-resistant K. pneumoniae isolated from any site. Available isolates underwent detection of the KPC-2 gene by polymerase chain reaction and molecular typing was performed to determine genetic relatedness between isolates. Point-prevalence screening was performed on selected wards to detect asymptomatic carriage. Infection control procedures were implemented to contain the outbreak.Ten cases were identified in the initial cluster. Eight were localised to a single inpatient ward. Point-prevalence screening revealed one extra case. After temporary containment, re-emergence of KPC-producing isolates was observed post October 2013 with 18 further cases identified. Four K. pneumoniae isolates in the 2012 cluster and 16 from the 2013-2014 cluster were referred for further testing. All carried the KPC-2 beta-lactamase gene. The 2012 isolates were genetically similar to the 2014 isolates.KPC-2 mediated resistance is an emerging threat in Australia. The re-emergence of KPC despite initial containment emphasises the need for constant vigilance in the microbiology laboratory and ongoing maintenance of infection control and antimicrobial stewardship activity.

In this paper, an investigation on the operational envelopes of electrically excited (EE) and hybrid excitation (HE) machines for electric vehicles (EV) is highlighted. A computationally efficient calculation method utilising 2D scanning of finite element analyses (FEA) having different d- and q-axis currents is developed. Compared with the conventional method, which typically requires 3D scanning of FEA having different excitation, d- and q-axis currents, the proposed method significantly reduces the complexity and the computation time. The accuracy of the new method is validated by direct FE results. It is further found that even for EE and HE machines the maximum constant power operation in the high speed range is achieved by employing flux weakening control by the armature current instead of applying a lower excitation current, which is also validated by analytical analyses.

To furnish a systemic effect after intranasal administration, a formulation must contain the therapeutic dose in no more than 150 μL, the maximum volume that can be applied as a single administration in one nostril in man. The objectives of these studies were to examine the local toxicity of formulations containing benzodiazepines and to document the effects to support clinical trials in man. After stability, pharmacological and pharmacokinetic studies of several benzodiazepine formulations, we studied nasal toxicity after single and repeated administration to rabbits of poly(ethylene glycol) 200, tetra(ethylene glycol), glycofurolum and mixtures of these vehicles both with and without benzodiazepines. Single-dose studies with examinations 5 or 10 min after application were undertaken with poly(ethylene glycol), tetra(ethylene glycol), glycofurolum and tetra(ethylene glycol)-glycofurolum in the ratio 95:5; the reactions were similar to that after physiological saline. A 14-day repeated-dose study was conducted with diazepam, lorazepam and flunitrazepam formulations in poly(ethylene glycol), and flunitrazepam in poly(ethylene glycol)-glycofurolum in the ratio 70:30; the two vehicles without any benzodiazepine were also examined. Microscopic study revealed mild changes only in the treated groups. A final four-week study was conducted with repeated administration of clonazepam formulated in tetra(ethylene glycol)-glycofurolum in the ratio 95:5; microscopy revealed mild changes after three 150-μL doses daily, but no abnormalities after one or three 100-μL doses daily. It was concluded that these three solvents individually or as mixtures resulted in only mild local toxicity and might be acceptable as vehicles in nasal preparations of benzodiazepines and other non-irritating drugs for short-term use in man.

The athymic (nude) rat (rnu/rnu) has been used for a number of years in research into various human tumours involving xenotransplantation. We now report the validation of a continuous intravenous infusion method in nude rats using a tail cuff tether, which enables the study of the efficacy of novel anti-cancer materials in this mutant strain, using intravenous infusion and with no restriction of the animals or of the tumour implantation sites by jackets. Ten animals each had a cannula surgically implanted into the vena cava via the femoral vein and exteriorized via a tail cuff. Animals were housed singly in conventional cages following surgery. Following a recovery period of 5 days all animals were continuously infused with physiological saline at an infusion rate of 0.5 ml/h for a further 37 days. Body weights and food consumption were recorded weekly. Blood samples were taken approximately 14 days post-surgery and analysed for haematology and clinical chemistry parameters. All animals were successfully cannulated, and no unexpected adverse clinical signs were noted during the recovery period and the 37 days of infusion. The results demonstrate that it is possible to surgically cannulate the femoral vein of athymic (nude) rats and infuse them in conventional cages for a period of up to 37 days with minimal adverse effects. The minimal restraint required provides benefits both to the animal and to the conduct of studies such as assessment of tumour growth in the absence of a jacket. Recent work has demonstrated that the same techniques can be successfully applied to the nude mouse.

Biosynthetic human growth hormone was injected subcutaneously in rats for 90 days and in cynomolgus monkeys for 30 days. The daily doses were 0.5, 3.3 and 25 IU kg-1 (rats) and 0.3 and 15 IU kg-1 (monkeys). The growth hormone was tolerated well in both rats and monkeys. No drug related deaths occurred and all animals appeared to be normal and also behaved normally throughout the dosing period. Increased body weight gain, increased food utilisation and increased organ weights were seen in the rats in the high and intermediate dose groups. The higher doses of human growth hormone (3.3 and 25 IU kg-1) caused a glandular hyperplasia of the mammary gland in male and female rats with evidence of secretory activity. In the female monkeys secretory activity was seen without any sign of mammary gland hyperplasia. Mucification of the vaginal epithelium and stress induced prostatitis was observed in the rats. Additional treatment related changes in the rats were an increased haematopoietic activity in the spleen and an increase in the amounts of calcium and phosphate excreted in urine. An increase in fasting plasma glucose levels was seen in the male monkeys on the high dose level. The changes observed during the treatment periods presumably represent exaggerated pharmacological effects of the growth hormone.

The basic design for the SSC started at Snowmass in the summer of 1982. The premise is that a superferric SSC has the potential to be simple, reliable, inexpensive and provide future flexibility. A concentrated effort began in March of 1984 when the Texas Accelerator Center was formed. The Texas Accelerator Center is a group of about 50 people divided into three areas of research, a calculations group working on beam dynamics, an R and D group working on superconducting magnets, and an R and D group working on new accelerator ideas including a proton linac and a plasma-laser accelerator. This paper will emphasize the work on the superferric magnet R and D.

Promozyme®, an amylopectin debranching enzyme produced by Bacillus acidopullulyticus , was studied to evaluate its safety in the food industry. A dietary subchronic toxicity study incorporating fertility and teratogenicity studies was performed in 1-month-old rats at concentrations of 0.5, 1.5 and 5% Promozyme. No adverse effects were seen at the 0.5 and 1.5% dose levels, and at the 5% dose level only minor or equivocal signs of toxicity were recorded. With the exception of a moderate reduction in body weight gain the FIA litters at the 5% dose level, no effects were found in the fertility study, and Promozyme was not teratogenic. In a 13-wk oral toxicity study in dogs, no adverse effects resulted from 0.5 g/kg/d, whereas mild gastrointestinal disturbances were seen clinically at 1.5 and 5.0 g/kg/d. In dogs given 5.0 g/kg/d, terminal investigations showed increased kidney weights and mineralized casts in renal cortical tubules. This was probably due to the high content of ash (phosphorus) in the test material. Lack of mutagenic potential was confirmed in bacterial mutagenic assays with Salmonella typhimurium (TA 1535, TA 1537, TA 1538, TA 98 and TA 100) and in an in vivo cytogenetic study in rat bone marrow cells after a single dose and daily dosing for 5 d of up to 8 g/kg/d. In an acute inhalation study with 4 h of exposure of rats, no death occurred at the highest dose level used, i.e., 2 mg/L. The test material was non-irritating to skin and did not produce eye injury in rabbits. A skin sensitization study in guinea pigs revealed no indication that the enzyme is a sensitizer. The pathogenic potential of the enzyme-producing B. acidopullulyticus was investigated by single intraperitoneal and subcutaneous administrations to rats and mice; the microorganism was found to be nonpathogenic (LD50>1010 cells/kg). Tests of culture broths revealed that the microorganism does not produce antibiotics. Results indicated that production and the intended use of Promozyme can be regarded as safe for plant workers and consumers.

Determined whether individuals who adapted well or poorly to the loss of their vision could be differentiated on the basis of the Cattell 16PF. Well adjusted individuals were defined as those who displayed minimal depression and high social independence, while poorly adjusted individuals were highly depressed and socially dependent. By the use of discriminant analysis based upon the standard 16PF, 84.5% of highly depressed and 81% of the minimally depressed group were classified accurately. In a second analysis, 75% of socially independent and 73% of socially dependent individuals were classified correctly. Premorbid characteristics of well and poorly adjusted blind Ss were described.

The use of the transfer rate of a volatile substance (ammonia) for the expeditious development of a method for quantitation of this substance during respirometric tests was discussed. A quantitative study of the conditions and details of the method were presented.

Psychiatry must increase the knowledge of adjustment to various physical disabilities if it is to act in a strong consultant role to medicine and surgery. To this end, the study of one hundred and fourteen adventitiously, declared blind subjects was carried out through structured interviews and psychological and social adjustment measures. The variables were statistically analysed, using the F test, Duncan's Multiple Range test and Canonical Correlation Analysis. The best social function occurred in the youngest age groups, those who had the highest yearly income at the time of maximum life function and who entered rehabilitation. The best psychological and social function was found in those who had given up false hope of regaining vision. The group who had not given up this false hope did poorly on social and psychological adjustment measures and were generally unemployed, coped poorly and did not attend programs in the Canadian National Institute for the Blind (CNIB). The onset of visual loss was found to be the time of greatest crisis, while declaration of blindness in itself led to no particular crisis with associated diminished social or psychological adjustment. Some concern is noted that the CNIB, the major caregiver for the blind, cannot offer assistance at onset because of the legal definition of blindness, and poor service may be furnished by family physicians, ophthalmologists and psychosocial helpers due to lack of understanding, shifting of responsibility and at times, neglect, assuming that the CNIB is assisting when they cannot or are not. More research is needed in all aspects of psychosocial care for the blind. Communicating among helping groups and with the CNIB is imperative if the visually handicapped are to get better psychosocial care.

Sunmasy.-This experiment investigated the relationship between coven and overt aversive stimuli at two intensities, and suppression of operant behaviour. Subjects were positively reinforced for responding on two manipulanda. A picture of the manipulandum that the subject pressed most frequently was paired with one of two intensities (high and low) of the covert and overt aversive stimuli. The results indicated that stimuli of high intensity suppressed responding more than those of low intensity on the preferred manipulandurn. No differences between covert and overt stimuli were found. On the nonpreferred manipulandum the intensity effect was nonsignificant. Coven stimuli did, however, result in greater increased responding on that manipulandum than the overt stimuli. Cautela (1970) has hypothesized that the variables which determine the effectiveness of covert sensitization are the same as those which control overt aversive conditioning. This conceptualization has been referred to as the "homogeneity assumption" (Thoresen & Mahoney, 1974). One variable assumed to play a prominent role in determining the success of overt aversion therapy has been the intensity of the aversive stimulus. The rationale for this has come primarily from animal research. kin and Holz (1966) have stated in their review of the parameters which control punishment that "all studies of the intensity of punishment have found that the greater the intensity of the punishing stimulus the greater reduction of the punished response" (p. 381). Similar findings have been reported in the classical conditioning literature. Increases in intensity have resulted in more rapid acquisition of the conditioned response and greater resistance to extinction (Spence, 1958). The intensity of the noxious stimulus in aversion therapy has received little attention. Turner (1973) has examined whether the intensity of electric shock affected homosexual behaviour following conditioning. Twenty-six male homosexuals volunteered and were randomly assigned to two groups. One group selected their own intensity of shock (M = 2.5 ma) while the second group were given 5 ma of stimulation. After 20 avoidance training sessions using Feldman and MacCulloch's (1965) procedure, the two groups were compared in terms of erectile responses to slides depicting male nudes. The results indicated that 5-ma groups produced less penile change to the sight of the male nude than the subjects who received the 2.5-ma shock. Unfortunately intensity of the aversive stimulus was confounded by the clients being able to make their choice of level of intensity and having it assigned for them.

Determined whether individuals who adapted well or poorly to the loss of their vision could be differentiated on the basis of the Cattell 16PF. Well adjusted individuals were defined as those who displayed minimal depression and high social independence, while poorly adjusted individuals were highly depressed and socially dependent. By the use of discriminant analysis based upon the standard 16PF, 84.5% of highly depressed and 81% of the minimally depressed group were classified accurately. In a second analysis, 75% of socially independent and 73% of socially dependent individuals were classified correctly. Premorbid characteristics of well and poorly adjusted blind Ss were described.

THE evidence linking brain function to amineoxidase activity1 has stimulated a large production of papers2. The disagreements that have ensued2 might well be a measure of the interest in these aminases. However, we attribute much of the discord to the accepted method of studying these trace enzymes, namely, respirometry. The present communication shows that respirometry is an erratic yardstick as compared with the measurements of ammonia (or primary amine) released by the amineoxidase reaction. The ease and accuracy of these latter micromethods have been shown previously3–9.

SEVERAL of the trace metals are primarily excreted via the bile1. The kinetics of excretion and reabsorption of bile-bound isotopes have been the subject of a study at this Center2,3.