1,150 research outputs found

    Finding RR Lyrae Stars with SkyMapper: an Observational Test

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    One of the major science goals of the SkyMapper Survey of the Southern Hemisphere sky is the determination of the shape and extent of the halo of the Galaxy. In this paper we quantify the likely efficiency and completeness of the survey as regards the detection of RR Lyrae variable stars, which are excellent tracers of the halo stellar population. We have accomplished this via observations of the RR Lyrae-rich globular cluster NGC 3201. We find that for single epoch uvgri observations followed by two further epochs of g, r imaging, as per the intended three-epoch survey strategy, we recover known RR Lyraes with a completeness exceeding 90%. We also investigate boundaries in the gravity-sensitive single-epoch two-color diagram that yield high completeness and high efficiency (i.e., minimal contamination by non-RR Lyraes) and the general usefulness of this diagram in separating populations.Comment: 10 pages, 5 figures, to appear in the Publications of the Astronomical Society of Australia (PASA), published by Cambridge University Pres

    Effects of ramadan fasting on cardiovascular and biochemical parameters

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    Background: Muslims abstain from food and drink from dawn to sunset every day during Ramadan - the holiest month in Islamic lunar calendar.  Methods: The effect of Ramadan fast on body mass index (BMI), blood pressure (BP), fasting blood glucose (FBG) and lipid profile were studied on 100 healthy male, adult Muslim volunteers. All parameters were recorded one week before the onset and then in the last week of Ramadan month and compared.  Results: There was no statistically significant effect on BMI, and systolic or diastolic blood pressures (p>0.05). However, fasting blood glucose (FBG), serum total cholesterol (TC), serum triglycerides (TG) were significantly decreased (p = 0.000) and high density lipoprotein cholesterol (HDL-C) level was significantly (p=0.000) increased in last week of Ramadan fasting compared to pre fasting levels. Conclusion: Our results show beneficial effects of Ramadan fasting on FBG and serum lipid profile. &nbsp

    Principles and mechanisms of ultraviolet light emitting diode technology for food industry applications

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    peer-reviewedThe application of ultraviolet (UV) light to water, food contact surfaces and medical equipment for microbial inactivation is widely employed. To date, UV disinfection sources employed are primarily low-pressure and medium-pressure mercury lamps; emitting monochromatic and polychromatic light, respectively. Despite the widespread use of mercury lamps, there are multiple drawbacks associated with their use including; high energy consumption, large size which limits reactor design, high heat emission and the presence of mercury. Light emitting diodes (LEDs) have potential for use as a highly efficient UV decontamination technology. Recent advances in semiconductor development have resulted in UV-LEDs becoming more widely available. UV-LEDs emit monochromatic light, which enables customised UV-LED disinfection systems at specific wavelengths to be developed. The application of UV-LEDs for disinfection purposes has been studied in recent years, particularly with respect to water disinfections systems. In this review, studies relating to UV-LED food applications are discussed. Furthermore, the chemical changes induced in foods, as a result of UV treatment, together with advantages and limitations of the technology are outlined

    Microstructure and Magnetic Properties of Very Thin CoCr Films Deposited on Different Underlayers by rf-Sputtering

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    Very thin CoCr films deposited on different underlayers on glass disk substrates were studied by the magneto-optic Kerr effect, VSM, torque magnetometry and TEM selected area diffraction. Square or near square perpendicular loops were obtained from Co/Ti, CoCr/Au, CoCr/Al, CoCr/C and CoCr/Si films. TEM SAD study revealed that the crystalline structure is a key factor determining the magnetic anisotropy of the very thin CoCr films. In particular, the c-axis of the hep CoCr films which exhibit square perpendicular loops is perpendicular to the film plane whilst that of the CoCr films which exhibit a thin and flat perpendicular loop lies in the film plane. The texture of the very thin CoCr films deposited on different underlayers is mainly dependent on the structure and texture of underlayers. The relation between the structure of CoCr and its underlayers is discussed

    A pilot study on the nanoscale properties of bone tissue near lacunae in fracturing women

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    The goal of this study is to investigate the causes of osteoporosis-related skeletal fragility in postmenopausal women. We hypothesize that bone fragility in these individuals is largely due to mineral, and/or intrinsic material properties in the osteocyte lacunar/peri-lacunar regions of bone tissue. Innovative measurements with nanoscale resolution, including scanning electron microscope (SEM), an atomic force microscope that is integrated with infrared spectroscopy (AFM-IR), and nanoindentation, were used to characterize osteocyte lacunar and peri-lacunar properties in bone biopsies from fracturing (Cases) and matched (Age, BMD), non-fracturing (Controls) postmenopausal healthy women. In the peri-lacunar space, the nanoindentation results show that the modulus and hardness of the Controls are lower than the Cases. The AFM-IR results conclusively show that the mineral matrix, maturity (peak) (except in outer/far regions in Controls) were greater in Controls than in Cases. Furthermore, these results indicate that while mineral-to-matrix area ratio tend to be greater, the mineral maturity and crystallinity peak ratio “near” lacunae is greater than at regions “far” or more distance from lacunae in the Controls only. Due to the heterogeneity of bone structure, additional measurements are needed to provide more convincing evidence of altered lacunar characteristics and changes in the peri-lacunar bone as mechanisms related to postmenopausal women and fragility. Such findings would motivate new osteocyte-targeted treatments to reduce fragility fracture risks in these groups

    The Pain Divide: a cross-sectional analysis of chronic pain prevalence, pain intensity and opioid utilisation in England

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    Objectives: Our central research question was, in England, are geographical inequalities in opioid use driven by health need (pain)? To answer this question, our study examined: (1) if there are regional inequalities in rates of chronic pain prevalence, pain intensity and opioid utilisation in England; (2) if opioid use and chronic pain are associated after adjusting for individual-level and area-level confounders. Design: Cross-sectional study design using data from the Health Survey for England 2011. Setting England. Primary and secondary outcome measures: Chronic pain prevalence, pain intensity and opioid utilisation. Participants: Participant data relating to chronic pain prevalence, pain intensity and opioid usage data were obtained at local authority level from the Health Survey for England 2011; in total, 5711 respondents were included in our analysis. Methods: Regional and local authority data were mapped, and a generalised linear model was then used to explore the relationships between the data. The model was adjusted to account for area-level and individual-level variables. Results: There were geographical variations in chronic pain prevalence, pain intensity and opioid utilisation across the English regions—with evidence of a ‘pain divide’ between the North and the South, whereby people in the North of England more likely to have ‘severely limiting’ or ‘moderately limiting’ chronic pain. The intensity of chronic pain was significantly and positively associated with the use of opioid analgesics. Conclusions: There are geographical differences in chronic pain prevalence, pain intensity and opioid utilisation across England—with evidence of a ‘pain divide’. Given the public health concerns associated with the long-term use of opioid analgesics—and their questionable activity in the management of chronic pain—more guidance is needed to support prescribers in the management of chronic pain, so the initiation of opioids can be avoided
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