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Biomedical subjects

W C Harris

Publications and source records attributed to W C Harris.

8 recordsLinked to original sources
PubMed2004

Out of the Smokescreen: does an anti-smoking advertisement affect young women's perception of smoking in movies and their intention to smoke?

OBJECTIVE: To evaluate the effect of an anti-smoking advertisement on young women's perceptions of smoking in movies and their intention to smoke. SUBJECTS/ SETTING: 2038 females aged 12-17 years attending cinemas in New South Wales, Australia. DESIGN/ INTERVENTION: Quasi-experimental study of patrons, who were surveyed after having viewed a movie at their local cinema. The control group was surveyed during week 1 and the intervention group, during week 2. Before seeing the movie in week 2, a 30 second anti-smoking advertisement was shown, which featured a well known female actor drawing attention to the prevalence of smoking in movies. OUTCOMES: Attitude of current smokers and non-smokers to smoking in the movies; intention of current smokers and non-smokers to be smoking in 12 months time. RESULTS: Among non-smokers, 48.2% of the intervention subjects thought that the smoking in the movie they viewed was "not OK" compared with 28.3% of the control subjects (p < 0.0001). However, there was no difference among smokers in the intervention (26.4%) and control (16.9%) groups (p = 0.28). A higher percentage of current smokers in the intervention group indicated they were unlikely to smoke in 12 months time (47.8%) than smokers in the control condition (31.9%) (p = 0.03). For non-smokers, there was no difference in smoking intentions between conditions, with 95% saying they would be unlikely to be smoking in 12 months time. CONCLUSIONS: This "real world" study suggests that placing an anti-smoking advertisement before movies containing smoking scenes can help to "immunise" young women against the influences of film stars smoking.

Adolescent↗
PubMed1995

Performance, workload, and fatigue changes associated with automation.

The experiments discussed in this article addressed the influence of part-task automation on operator performance, workload, and fatigue in a multitask environment. The overall task environment included tracking, resource management, and multiple monitoring subtasks. Slower, more accurate monitoring and better resource management were observed when the tracking subtask was automated. Although lower workload was reported when tracking was automated, fatigue increased equally during periods of manual and automatic tracking. When participants could control workload by shifting between manual and automatic tracking, participants with 7 hr of training switched between automatic and manual tracking. Their performance during optional automation periods was superior to their performance in conditions in which only manual control or only automated control was available. The findings argue for the utility of discretionary control of automated systems.

Adult↗
PubMed1985

A Raman spectroscopic study on the effect of cholesterol on lipid packing in diether phosphatidylcholine bilayer dispersions.

For assessing lipid-sterol packing characteristics in model membrane systems, the vibrational Raman spectra of 1,2-di-O-hexadecyl-sn-glycero-3-phosphocholine (DHPC) multilamellar dispersions containing 18 mol% cholesterol were examined. The thermotropic behavior of the pure diether- and cholesterol-containing bilayers were studied in both the C-H stretching (2800-3100 cm-1) and C-C stretching (1000-1200 cm-1) mode regions, spectral intervals reflecting intermolecular and intramolecular order/disorder characteristics. Pure DHPC bilayers exhibit the pretransition and gel to liquid-crystalline phase transition temperatures at approx. 31 and 42.8 degrees C, respectively. In contrast to the temperature behavior of dipalmitoylphosphatidylcholine-cholesterol bilayers in which the primary phase transition Tm, is simply broadened, Tm is increased to approx. 49.6 degrees C in the DHPC (diether PC) liposomes containing 18 mol% cholesterol. As in the saturated chain diacyl-cholesterol bilayer systems, the sterol disorders the DHPC gel phase and eliminates the pretransition, while ordering the liquid-crystalline phase. Pure diether liposomes exhibit a headgroup dehydration effect as the multilamellar dispersions are cycled slowly over a temperature range including the gel and liquid-crystalline forms. That is, on multiple passages through the phase transitions, both the gel and liquid-crystalline bilayer forms assume an increased hydrocarbon chain order. In the cholesterol-containing diether bilayers, only the disordered intra- and interchain states are formed.

Chemical Phenomena↗
PubMed1984

Distribution of calcium during interphase and mitosis as observed by ion microscopy.

The ion microscope, based on secondary ion mass spectrometry, has been used to demonstrate the distribution of calcium in the root tip cells of two plant species, Allium cepa and Vicia faba. Interphase nuclei showed higher intensities of calcium than cytoplasm, while nucleoli exhibited higher calcium intensities than the rest of the nucleoplasm. The chromosomes showed high intensities of calcium at all stages of mitosis. Calcium was also detected in the cell plate and phragmoplast region of dividing cells. It appears that during prophase calcium concentrates in the condensing chromosomes, and during telophase it is transferred to nucleoli. These observations suggest that chromosomes may serve as a reservoir of calcium during mitosis.

Calcium↗