8,663 research outputs found

    A layered approach to (past) habituality in English

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    In this paper, we investigate whether expressions of habituality in UK English, in particular adverbs of event distribution and the auxiliaries used to and would, pertain to hierarchically different layers of semantic organization, in the sense that they would have different portions of the semantic structure in their scope. This question is addressed using the framework of Functional Discourse Grammar. The application of the Complement Clause Test and the Scope Test reveals that indeed habituality operates at three different layers: adverbs of event distribution operate at the layer of the Configurational Property, used to at the next higher layer, that of the State of Affairs, and would at the next higher layer, that of the Episode

    Focusing of Intense Subpicosecond Laser Pulses in Wedge Targets

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    Two dimensional particle-in-cell simulations characterizing the interaction of ultraintense short pulse lasers in the range 10^{18} \leq I \leq 10^{20} W/cm^{2} with converging target geometries are presented. Seeking to examine intensity amplification in high-power laser systems, where focal spots are typically non-diffraction limited, we describe key dynamical features as the injected laser intensity and convergence angle of the target are systematically varied. We find that laser pulses are focused down to a wavelength with the peak intensity amplified by an order of magnitude beyond its vacuum value, and develop a simple model for how the peak location moves back towards the injection plane over time. This performance is sustained over hundreds of femtoseconds and scales to laser intensities beyond 10^{20} W/cm^{2} at 1 \mu m wavelength.Comment: 5 pages, 6 figures, accepted for publication in Physics of Plasma

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    Australian parents’ experiences with universal child and family health services

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    © 2018 Australian College of Nursing Ltd Background: Australian governments provide free services to promote maternal and child health, and to support parenting for families with children up to age five. Services are principally provided by dedicated child and family health nurses, but also by general practitioners, practice nurses, pharmacy nurses and midwives. Aim: This study aimed to examine the experiences of families with young children across Australia in accessing and receiving health care for well children, parenting support and advice from a range of providers. Methods: The study used quantitative and qualitative data from an online survey of 719 parents and carers with children aged up to five years. Findings: On quantitative scales, most respondents rated healthcare providers favourably for accessibility, credibility and their approach to families. However, qualitative responses revealed widely varying reactions to child and family health provision. Parents described both positive and negative experiences, highlighting elements of practice that are critical to consumer engagement. Discussion: Parents require health care and support that are accessible, consistent, affordable, encouraging, trustworthy, evidence-based and non-judgemental. Parents feel more confidence in the information and care provided by health professionals who are well-informed, resourceful and who respect their knowledge and beliefs. Conclusion: The findings demonstrate ways in which child and family health providers can engage and effectively support families with young children

    Two Galaxy Clusters: A3565 and A3560

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    We report 102 new redshifts and magnitudes for a sample of galaxies to RF ~ 15.5 mag in a 2.17 deg x 2.17 deg region centered on the galaxy IC 4296, the most luminous member of the A3565 cluster. Up to the limiting magnitude we find 29 cluster members, and measure a velocity dispersion of 228 km/s. The estimated total mass for this system is ~ 3.0 x h**-1 10**13 Msun (where h = H0/100 km/s/Mpc), and its dynamical properties are quite typical of poor clusters presenting X-ray emission. We also find that galaxies with absorption lines are more concentrated towards the center of the cluster, while systems with emission lines are mainly located in the outer parts. The small velocity dispersion of the cluster, coupled to the known presence of an interacting pair of galaxies, and the large extent of the brightest cluster galaxy, could indicate that galaxy formation through mergers may still be underway in this system. The surveyed region also contains galaxies belonging to the Shapley Concentration cluster A3560. Within 30 arc min of the cluster center, we detect 32 galaxies, for which we measure a velocity dispersion of 588 km/s and a mass of ~2 x h**-1 10**14 Msun. However, because our sample is restricted to galaxies brighter than M*, these values should be considered only as rough estimates.Comment: 33 pages, including 6 tables and 9 postscript figures. Uses AAS Latex macros. Postscript file and ASCII versions of Tables 4 and 6 are available at http://www.dan.on.br/other_surveys/a3565.html. Scheduled for September 1999 issue of The Astronomical Journa

    A comparison of four different imaging modalities - conventional, cross polarized, infra-red and ultra-violet in the assessment of childhood bruising

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    Background It is standard practice to image concerning bruises in children. We aim to compare the clarity and measurements of bruises using cross polarized, infra-red (IR) and ultra-violet (UV) images to conventional images. Methods Children aged <11 years with incidental bruising were recruited. Demographics, skin and bruise details were recorded. Bruises were imaged by standard protocols in conventional, cross-polarized, IR and UV lights. Bruises were assessed in vivo for contrast, uniformity and diffuseness, and these characteristics were then compared across image modalities. Color images (conventional, cross polarized) were segmented and measured by ImageJ. Bruises of grey scale images (IR, UV) were measured by a ‘plug in’ of ImageJ. The maximum and minimum Feret's diameter, area and aspect ratio, were determined. Comparison of measurements across imaging modalities was conducted using Wilcoxon rank sum tests and modified Bland-Altman graphs. Significance was set at p < 0.05. Results Twenty five children had 39 bruises. Bruises that were of low contrast, i.e. difficult to distinguish from surrounding skin, were also more diffuse, and less uniformity in vivo. Low contrast bruises were best seen on conventional and cross-polarized images and less distinctive on IR and UV images. Of the 19 bruises visible in all modalities, the only significant difference was maximum and minimum Feret's diameters and area were smaller on IR compared to conventional images. Aspect ratios were not affected by the modality. Conclusions Conventional and cross-polarized imaging provides the most consistent bruise measurement, particularly in bruises that are not easily distinguished from surrounding skin visually

    Perceived importance of components of asynchronous music in circuit training

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    This study examined regular exercisers’ perceptions of specific components of music during circuit training. Twenty-four men (38.8 years, s = 11.8 years) and 31 women (32.4 years, s = 9.6 years) completed two questionnaires immediately after a circuit training class. Participants rated the importance of 13 components of music (rhythm, melody, etc.) in relation to exercise enjoyment, and each completed the Affect Intensity Measure (Larsen, 1984) to measure emotional reactivity. Independent t tests were used to evaluate gender differences in perceptions of musical importance. Pearson correlations were computed to evaluate the relationships between affect intensity, age and importance of musical components. Consistent with previous research and theoretical predictions, rhythm response components (rhythm, tempo, beat) were rated as most important. Women rated the importance of melody significantly higher than did men, while men gave more importance to music associated with sport. Affect intensity was found to be positively and significantly related to the perceived importance of melody, lyrical content, musical style, personal associations and emotional content. Results suggest that exercise leaders need to be sensitive to personal factors when choosing music to accompany exercise. Qualitative research that focuses on the personal meaning of music is encouraged

    GRB 021004: A Possible Shell Nebula around a Wolf-Rayet Star Gamma-Ray Burst Progenitor

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    The rapid localization of GRB 021004 by the HETE-2 satellite allowed nearly continuous monitoring of its early optical afterglow decay, as well as high-quality optical spectra that determined a redshift of z3=2.328 for its host galaxy, an active starburst galaxy with strong Lyman-alpha emission and several absorption lines. Spectral observations show multiple absorbers at z3A=2.323, z3B= 2.317, and z3C= 2.293 blueshifted by 450, 990, and 3,155 km/s respectively relative to the host galaxy Lyman-alpha emission. We argue that these correspond to a fragmented shell nebula that has been radiatively accelerated by the gamma-ray burst (GRB) afterglow at a distance greater than 0.3 pc from a Wolf-Rayet star progenitor. The chemical abundance ratios indicate that the nebula is overabundant in carbon and silicon. The high level of carbon and silicon is consistent with a swept-up shell nebula gradually enriched by a WCL progenitor wind over the lifetime of the nebula prior to the GRB onset. The detection of statistically significant fluctuations and color changes about the jet-like optical decay further supports this interpretation since fluctuations must be present at some level due to inhomogeneities in a clumpy stellar wind medium or if the progenitor has undergone massive ejection prior to the GRB onset. This evidence suggests that the mass-loss process in a Wolf-Rayet star might lead naturally to an iron-core collapse with sufficient angular momentum that could serve as a suitable GRB progenitor.Comment: Replaced with version accepted by ApJ; 40 pages, 9 figure

    Increased pCO2 changes the lipid production in important aquacultural feedstock algae Isochrysis galbana, but not in Tetraselmis suecica

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    Increased anthropogenic CO2 emissions are leading to an increase in CO2 uptake by the world's oceans and seas, resulting in ocean acidification with a decrease in global ocean water pH by as much as 0.3–0.4 units by the year 2100. The direct effects of changing pCO2 on important microalgal feedstocks are not as well understood. Few studies have focused on lipid composition changes in specific algal species in response to ocean acidification and yet microalgae are an indispensable food source for various marine species, including juvenile shellfish. Isochrysis galbana and Tetraselmis suecica are widely used in aquaculture as feeds for mussels and other shellfish. The total lipid contents and concentrations of I. galbana and T. suecica were investigated when grown under present day (400 ppm) and ocean acidification conditions (1000 ppm) to elucidate the impact of increasing pCO2 on an important algae feedstock. Total lipids, long-chain alkenones (LCAs) and alkenoates decreased at 1000 ppm in I. galbana. I. galbana produces higher lipids than T. suecica, and is perhaps as a result more impacted by the change in carbon available for lipid production under higher pCO2. I. galbana is an important feedstock, more easily assimilated for growth in juvenile shellfish and reductions in lipid composition may prove problematic for the growth of future shellfish aquaculture. Our findings suggest that higher pCO2 impacts on algal lipid growth are species specific and warrant further study. It is therefore vital to examine the impact of high CO2 on algal lipid production, especially those commercial shellfish feed varieties to predict future impacts on commercial aquaculture
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