3,686 research outputs found
Aspects of the washout of salmonid eggs. 4. Effects of a standard mechanical shock, applied at different stage of development, upon survival and development of eggs of brown trout (Salmo trutta L.)
It is generally accepted by fish culturists that salmonid eggs are sensitive to mechanical shock and that the sensitivity varies with the stage of development of the eggs. In general, the period of greatest sensitivity is thought to occur between fertilization and ”eyeing”. However, it is reasonable to expect that, during a period (perhaps of several hours) following fertilization, sensitivity will be low because in nature during this period the eggs may be subject to some mechanical shock caused by the parent fish covering them with gravel. In 1983-4 and 1984-5 experiments were performed on brown trout (Salmo trutta L.) eggs to examine the effect of a standard mechanical shock (c. 2,500 eggs in 1983-4 and c. 8,400 eggs in 1984-5) at various stages of development upon survival to hatching and time of hatching.The results of these experiments are reported in this study
Groundbased near-IR observations of the surface of Venus
We present images of the nightside of Venus taken in the near-infrared windows at 1.0, 1.1, 1.18, 1.28, 1.31, and 2.3 microns with the new infrared camera/spectrometer IRIS on the Anglo-Australian Telescope. These data were taken in spectral-mapping mode. This technique involves scanning the telescope perpendicular to the slit, while collecting spectra at successive slit positions across the planet. We produce data cubes with one spectral and two spatial dimensions. Images can be extracted over any wavelength regions. Each image has square pixels of 0.8 inch resolution. We reduced the scattered light from the sunlit crescent in images extracted from each window by subtracting images taken on either side of the window, where the Venus atmosphere is opaque. Unlike the short wavelength windows, which reveal thermal contrasts that originate primarily from the surface and deep atmosphere, the emission in the 2.3 microns window is produced at much higher altitudes (30-40 km). Emission contrasts seen near 2.3 microns are associated with horizontal variations in the cloud optical depths, and have rotation periods of about six days. We detect large contrasts in infrared emission (20-40 percent) across the disc of Venus in the 1.0-, 1.1-, 1.18-, 1.28-, and 1.31-micron images. Contrasts at these wavelengths may be due to a combination of variations in the optical depths of the overlying sulfuric acid clouds and differences in surface emission. Comparison with the 2.3-micron images show that the patterns seen in the 1.28- and 1.31-micron windows are consistent with cloud optical depth variations alone and require no contribution from the surface. However, images at 1.0, 1.1, and 1.8 microns from July 1991 show a dark feature having a contrast that increases with decreasing wavelength. This behavior is contrary to that expected of cloud absorption. Images taken on three successive days in October show another dark feature that is stationary with respect to the surface. These regions of lower emission correspond closely to the high-altitude surface regions of Beta Regio and Aphrodite Terra. The images can potentially reveal the near-infrared emissiveity of the surface of Venus, thereby complementing Magellan radar reflectivity and ground based radio emissivity measurements. The contrast ratio between highlands and plains is much smaller than would be expected for blackbody radiation from the surface along. Unlike at radio wavelengths, where the atmosphere is essentially transparent, at near-infrared wavelengths the atmosphere emits, absorbs, and scatters radiation, and can modify the observed topographically induced contrasts. The additional radiation from the atmosphere reduces the contrast, and further modification would be expected if terrain at different altitudes has different emissivities. A fit to our data therefore requires, and may constrain, a model of the lowest scale height of the atmosphere
Do schools promote social inclusion? The experiences of intercountry adoptees in Australia
Intercountry adoption programs have brought children from racially and culturally diverse backgrounds to live as Australians, including 30 children from Rangsit Children’s Home who arrived in South Australia in the late 1980s and early 1990s. As part of a project which explored the life experiences of 12 adults who had arrived as children aged between 4 and 9 from Rangsit, this paper explores the role of schools in facilitating their inclusion into life in Australia. The school experience was often critical in learning English and was pre-requisite for acceptance in the school yard but also a place in which most of these Thai-born intercountry adoptees experienced racism. More than half of the participants did not complete secondary school but all had employment. However, many of these jobs were low-paying and this precluded them from participating in opportunities to return to Thailand to learn more about their Thai origins or participating as adoptive parents in intercountry adoption programs. Hence, while schools can play an important role in facilitating social inclusion, the school system alone may be unable to address the multiple dimensions of exclusion experienced by intercountry adoptees
Near-infrared oxygen airglow from the Venus nightside
Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen airglow emission from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The airglow is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) airglow. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus
From Paper to Praxis: Advancing the Discipline in a Small College Environment
This article proposes the advancement of communications discipline at a small college in Georgia. In the small liberal arts college, one tends to find many faculty members who have had little or no experience with departments of communication. It is also plausible that some approaches to the study of communication may be deemed unsuitable in a small liberal arts setting. To meet the demands of the millennial technological environment, the dean of the college decided to reexamine the communication major in terms of its scope and function on campus. The proposals for the advancement of the discipline are discussed herein
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RFID Enabled Health Monitoring System for Aircraft Landing Gear
RFID has been used in the aviation industry to track and identify emergency equipment and other in-cabin assets on commercial aircraft for some time. Recently, the industry is looking to expand the use of RFID to more demanding parts and surfaces both inside and outside of an aircraft’s cabin, where RFID tags face much harsher conditions. The lLanding gear (LG) is one of the critical subsystems of an aircraft that plays an essential role in dispersing the energy of landing events and taxiing. Health monitoring of the LG has been suggested to help reduce both operational and maintenance costs, and extend the life of the LG beyond its current, fixed, designed service life. In this paper, we propose such a health monitoring system using a combination of active wired sensors and passive RFID tags. We present the measurement of UHF RFID tags on an aircraft landing gear using an aircraft-mounted fixed RFID reader. The results indicate that all major landing gear components and assemblies are shown to be identifiable by their EPC, and a 7 dB system margin has been achieved using 2 RFID reader antennas. Such a margin will tolerate degradations caused by harsh environments (e.g. low temperatures and high humidity) and enable update of information (e.g. flight count) to be stored on the RFID tags
Are codes of ethics promoting religious literacy for social work practice?
As codes of ethics play at least a symbolic, if not educational, role in highlighting and informing professional priorities, 16 codes of ethics for social work practice were examined for references to religion and belief and analysed against the four domains of Dinham’s religious literacy framework. Although religion and belief are mentioned in all but two of the documents, approximately half the surveyed codes only mention religion and belief in respect of either knowledge or skills. Some recognise the need for social workers to be aware of their own biases, but very few recognise the need to explain what is meant by religion and belief, despite these terms being in flux. While codes of ethics can contribute to the development of religious literacy among social workers, this requires social workers who already have some religious literacy to actively participate when codes of ethics are being revised
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