Search

Background: Investigations of oral ethanol self-administration in nonhuman primates have revealed important parallels with human alcohol use and abuse, yet many fundamental questions concerning the individual risk to, and the biological basis of, excessive ethanol consumption remain unanswered. Moreover, many conditions of access to ethanol in nonhuman primate research are largely unexplored. This set of experiments extends within- and across-session exposure to ethanol to more fully characterize individual differences in oral ethanol self-administration. Methods: Eight male and eight female adult cynomolgus monkeys (Macaca fascicularis) were exposed to daily oral ethanol self-administration sessions for approximately 9 months. During the first 3 months, a fixed-time (FT) schedule of food delivery was used to induce the consumption of an allotted dose of ethanol in 16-hr sessions. Subsequently, the FT schedule was suspended, and ethanol was available ad libitum for 6 months in 16- or 22-hr sessions. Results: Cynomolgus monkeys varied greatly in their propensity to self-administer ethanol, with sex and individual differences apparent within 10 days of ethanol exposure. Over the last 3 months of ethanol access, individual average ethanol intakes ranged from 0.6 to 4.0 g/kg/day, resulting in blood ethanol concentrations from 5 to 235 mg/dl. Males drank approximately 1.5-fold more than females. In addition, heavy-, moderate-, and light-drinking phenotypes were identified by using daily ethanol intake and the percentage of daily calories obtained from ethanol as criteria. Conclusions: Cynomolgus monkeys displayed a wide intersubject range of oral ethanol self-administration with a procedure that used a uniform and prolonged induction that restricted early exposure to ethanol and subsequently allowed unlimited access to ethanol. There were sex and stable individual differences in the propensity of monkeys to consume ethanol, indicating that this species will be important in characterizing risk factors associated with heavy-drinking phenotypes.

We investigated life history traits (body sizes, sexual maturity, sexual dimorphism, clutch size) and dietary preferences in the sympatric lizards, Oligosoma nigriplantare polychroma and Oligosoma lineoocellatum (Scincidae). One‐hundred and forty O. n. polychroma and 153 O. lineoocellatum were collected for a twelve month period. Our results show that these sympatric species have different life history traits, notably in body size, size at maturity, and reproductive output. O. n. polychroma were smaller (51.72 mm adult males, 56.74 mm adult females) than O. lineoocellatum (70.70 mm adult males, 76.30 mm adult females). Size at maturity was determined by logistic regression models of snout‐vent length (SVL) for both species. O. n. polychroma reached sexual maturity at a relatively smaller SVL (42.21 mm) than O. lineoocellatum (62.11 mm), and had a larger mean clutch size (5.79) than O. lineoocellatum (3.82). There were some differences in diet, although both species consumed a wide range of prey, ...

For efficiently measuring ultraviolet transmission through clothing materials for a large number of samples, an automated measuring system with a broad-band method has been built and calibrated against a spectroradiometer based instrument. The apparatus can be used to test 60 samples in 25 min. A selection of clothing materials of known composition, weave, color and state have been tested, using the broad band method and the automated measuring system together with a solar ultraviolet simulator. Variations of about eleven times for different weave structure, about two times in the ultraviolet transmittance for different colors, and about 20 times for some stretched samples were observed. For wet conditions, an increment in ultraviolet transmittance for cotton and lycra materials and a decrement for polyester and polyester(65%)/cotton(35%) were also observed.

The population size, distribution, breeding, and onshore habitats of New Zealand fur seals in the Nelson‐northern Marlborough region, New Zealand, were investigated. Breeding occurs at four relatively new rookeries along the southern shores of Cook Strait: at Stephens Island in the outer Marlborough Sounds, at Archway Islands and Pillar Point near Cape Farewell, and at Tonga Island in Tasman Bay. These rookeries were established in about 1970, 1980, 1988, and 1988, respectively. In 1993–94 about 500 pups were born and the extant population breeding or born at the four rookeries was assessed as 2410. There were also 17 hauling grounds, each with 25 or more seals ashore in winter, and about 50 other sites where lesser numbers hauled out regularly. Comparison with earlier estimates indicates that the summer population increased from about 70 in 1973 to about 1000 in 1994—a sevenfold increase of yearling and older seals. The number of pups produced increased at a mean annual rate of 23% since 1970–71...

Honeydew drops produced by beech scale insects (Ultracoelostoma assimile) on beech trees (Nothofagus) were measured on three areas of trunk: an unprotected control area, an area screened to allow insects but not birds to feed on the honeydew, and an area screened to exclude all insects and birds. The experiments showed honeyeater birds (tui, bellbirds, and silvereyes) had little effect on the honeydew, but that cropping by German wasps (Vespula germanica), and particularly by common wasps (V. vulgaris), in the summer and autumn months markedly reduced the number, size, and sugar concentration of the honeydew drops. The energy in drops per unit area of tree trunk was reduced by at least 99.1%, 98.4%, and 91.3% in January, March, and May, respectively. Wasps reduced the standing crop (number, size, and sugar concentration) of the honeydew drops by cropping them before they could be fully recharged and before evaporation could concentrate the sugars. Cropping by feral honey bees (Apis mellifera) may ...

Aerial reconnaissance and photography were used in the Ross Sea sector of Antarctica to determine the breeding locations of Adelie penguinsPygoscelis adeliae, and to count the numbers of nests occupied during the early incubation period. From 1981 to 1987, all islands and sea coasts between 158°E and 175°E were searched, and 11 previously unreported breeding rookeries were discovered. Thirty-eight Adé1ie rookeries are now known from the region, with a total of about 1,082,000 breeding pairs — almost half the world population. Some rookeries were photographed in all, or most, of the seven seasons to study the pattern of natural fluctuations in Adelie populations, and comparisons have been made with earlier counts. Populations at nearly all rookeries have increased in size over the last 10–20 years. Possible reasons for this, and for annual fluctuations in numbers breeding, include seasonal variations in. sea ice and weather conditions, and longer-term climatic change.

In 1975, the Masters Degree in Medical Physics was first made available at the Queensland Institute of Technology (now Queensland University of Technology, QUT), and is offered on both a part time and full time basis. An option for a Graduate Diploma award after completion of the in-house course work stage is available. The research project may be undertaken either in Brisbane or elsewhere. Such projects have been undertaken in Perth, Hong Kong, Sydney, etc. It is a broad based program, embracing activities of current professional importance while including aspects which have potential importance. Recognition that medical physics is a dynamic speciality ensures that the content of the program is kept under continuous review, and changes made as required. It is of interest to observe that of graduates from the course, approximately 50% have moved into the hospitals and private medical research, 11% into government health departments, 16% into the mining industry, 9% into tertiary education, and 14% into non medical or sales areas. Many have gained senior positions in their selected vocations. The success of the program in providing a useful professional person is due in no small measure to the collaboration of many dedicated professionals in the field. This collaboration relates to informal and formal contact between academic staff and students within the Physics Department, and personnel in hospitals, public health establishments and industry.

Measurements have been made of high-energy capture gamma -ray spectra following neutron capture by 93Nb for discrete resonances up to 1 keV and for unresolved regions up to 6 keV, with the aim of investigating the reaction mechanism. Spin assignments have been made for s-wave and p-wave resonances using the low-level population method, and also using primary transitions. A determination of the neutron binding energy has been made, and a level scheme of 94Nb has been constructed for states up to 1520 keV populated by primary transitions. A significant correlation has been found between (d,p) intensities and average partial radiation widths to the same final states, for resolved p-wave resonances below 1 keV and for average regions at higher energies (up to 6 keV). The distributions of partial radiation widths for M1 and E1 transitions in s-wave and p-wave resonances were consistent with the Porter-Thomas prediction.

Measurements have been made of high-energy neutron capture gamma ray spectra from the 103Rh(n, gamma )104Rh reaction for discrete resonances up to 850 eV and for unresolved regions up to 6 keV, with the aim of investigating the reaction mechanism. Spins of stronger resolved s-wave resonances up to 1272 eV were assigned using low-energy capture gamma rays, and in some cases also using high energy gamma rays. A value was obtained for the neutron binding energy, and a level scheme was constructed for 104Rh states up to 1 MeV populated by primary transitions. The distribution of a sample of 1938 reduced partial radiation widths in spin 1 resonances were found. The averaged gamma -ray spectra up to 6 keV showed an enhancement in the region 6.0-6.2 MeV, confirming previous observations. No correlations were found between resonance reduced neutron widths and reduced partial radiation widths in any part of the gamma -ray spectrum.

Neisseria meningitidis was recovered from the urethra of nine and from the anal canal of seven men, and from the cervix of two women. Twelve of the 16 men were admitted homosexuals. Seven men had no symptoms, while the remainder had mild to moderate symptoms. One woman was asymptomatic and the other was in hospital with acute salpingitis. Reports of previous isolations of meningococci from the urethra, cervix, or anal canal are reviewed. It is concluded that in men, these infections are usually mild and self-limited, but in women, meningococcal genital infections frequently proceed to severe disease.

It is argued that capture of a carrier into the ground state of a deep, charged trap will be preceded by capture into a shallow, excited state. The temperature dependences of capture and re-emission are worked out as consequences of this two step model. Predictions are compared with measurements on the hole trap in GaP at E T = E v + 0·75eV.

A system designed for the in vivo measurement of the cadmium content of the liver or kidneys is described. Performance characteristics are given and compared with those of two other portable systems reported in the literature. The present system uses a new source-subject-detector arrangement and incorporates considerably cheaper shielding materials. The system is in use to measure liver and kidney levels in industrially exposed workers and in persons with diseases in which cadmium may be involved.

The results of a programme of research on nitrogen doped green-emitting diffused VPE LEDs are reported. The purpose of this work was to establish whether the recombination processes which control final device efficiencies occur on the p or n side of the junction. To do this we have used a novel technique which involves fabricating diodes down a bevelled epitaxial “sandwich” structure consisting of a nitrogen doped region between non nitrogen doped ones. We find that the light output from the n side is approximately a factor 1.5 times the p side output. Hence both the p and n regions of these diffused structures yield significant light outputs, although the contribution from the n side usually dominates. The above result together with cathodoluminesence efficiency measurements on p - and n -type material suggests the device injection ratio (β), defined as the ratio of injected hole and electrom currents, is β = J h / J e ∼ 3 − 4.5. Attempts at calculating β for these LEDs have shown that the effects of high level injection, built-in field and breakdown of the depletion approximation must be taken into account if realistic device modelling is to be carried out. The results of this work are believed to have important practical implications because they suggest that significant improvements in device efficiencies can be obtained by modifying the doping profile to increase the electron injection efficiency into the higher luminescence efficiency p -type material.

Hoplodactylus rakiurae n.sp. is described, and some aspects of its ecology arc noted. It has enlarged apical plates on all digits, and is the most brightly coloured Hoplodactylus. Heteropholis nebulosus McCann, also from Stewart Island, is synonymised with Hoplodactylus granulatus (Gray), for which an updated synonymy is listed and discussed.

A group of 200 Queensland adults without known health problems had in-vivo estimation of finger bone lead concentrations using X-ray fluorescence analysis (XRF). Forty of these subjects had elevated levels of bone lead of 25 ppm or more, consistent with exposure to the metal. Although the correlation between Queensland residence during childhood and raised bone lead levels was not significant, there were significant correlations between childhood residence in a painted wooden house and raised levels, and between occupational exposure and raised levels. Of the 40 subjects with elevated lead levels only two had neither a history of occupational exposure or childhood residence in a wooden house, whereas 11 of the 25 who had a history of both occupational and residential exposure were positive. The data are consistent with lead in housepaint, or absorbed during occupational exposure, being the two major sources of raised bone lead concentrations.

Ion implantation of P, V, N, O, Ar and Ne into n-type Li-doped ZnO has been investigated with energy up to 300 keV at dose levels 1012-1016 cm−2. Measurements of sheet conductivity and Hall mobility as a function of anneal temperature have given evidence of n-type layers after P and V implantation, with sheet conductivities 105 times higher than unimplanted and Ar-implanted material. It has also been found that an isochronal anneal sequence, terminated by a 1 h, 450 °C vacuum anneal and then a water quench, is sufficient to remove most of the electrical effects of damage produced by ion implantation.

Photostimulated exoelectron emission resulting from the plastic deformation of aluminium has recently been shown to originate from the slip lines produced. In this letter it is shown that the origin of the contrast mechanism is better described in terms of exoelectron emission from a transitional metal-oxide layer which forms over the exposed metal at the slip plane, rather than from the bare metal as proposed.