2,025 research outputs found

    Uniaxial magnetocrystalline anisotropy in CaRuO3{\rm CaRuO_3}

    Full text link
    CaRuO3{\rm CaRuO_3} is a paramagnetic metal and since its low temperature resistivity is described by ρ=ρ0+ATγ\rho=\rho_0+AT^\gamma with γ1.5\gamma \sim 1.5, it is also considered a non-Fermi liquid (NFL) metal. We have performed extensive magnetoresistance and Hall effect measurements of untwinned epitaxial films of CaRuO3{\rm CaRuO_3}. These measurements reveal that CaRuO3{\rm CaRuO_3} exhibits uniaxial magnetocrystalline anisotropy. In addition, the low-temperature NFL behavior is most effectively suppressed when a magnetic field is applied along the easy axis, suggesting that critical spin fluctuations, possibly due to proximity of a quantum critical phase transition, are related to the NFL behavior.Comment: 7 figure

    Bunk attendance of feedlot cattle monitored with radio frequency technology

    Get PDF
    Bunk attendance of 72 feedlot cattle (412 ± 23.6 kg) was monitored for 86 d using radio frequency technology. Late morning and late afternoon were confirmed as primary ad libitum feeding periods. The system detected differences (P \u3c 0.005) in feeding behaviour in response to level of feeding and frequency of meals

    A survey of SiO 5-4 emission towards outflows from massive young stellar objects

    Full text link
    Results are presented of a survey of SiO 5-4 emission observed with the James Clerk Maxwell Telescope (JCMT) towards a sample of outflows from massive young stellar objects. The sample is drawn from a single-distance study by Ridge & Moore. In a sample of 12 sources, the 5-4 line was detected in 5, a detection rate of 42 per cent. This detection rate is higher than that found for a sample of low-luminosity outflow sources, although for sources of comparable luminosity, it is in good agreement with the results of a previous survey of high luminosity sources. For most of the detected sources, the 5-4 emission is compact or slightly extended along the direction of the outflow. NGC6334I shows a clear bipolar flow in the 5-4 line. Additional data were obtained for W3-IRS5, AFGL5142 and W75N for the 2-1 transition of SiO using the Berkeley-Illinois-Maryland Association (BIMA) millimetre interferometer. There is broad agreement between the appearance of the SiO emission in both lines, though there are some minor differences. The 2-1 emission in AFGL5142 is resolved into two outflow lobes which are spatially coincident on the sky, in good agreement with previous observations. In general the SiO emission is clearly associated with the outflow. The primary indicator of SiO 5-4 detectability is the outflow velocity, i.e. the presence of SiO is an indicator of a high velocity outflow. This result is consistent with the existence of a critical shock velocity required to disrupt dust grains and subsequent SiO formation in post-shock gas. There is also weak evidence that higher luminosity sources and denser outflows are more likely to be detected.Comment: Accepted for publication in MNRA

    Zoonotic host diversity increases in human-dominated ecosystems

    Get PDF
    Land use change—for example, the conversion of natural habitats to agricultural or urban ecosystems—is widely recognized to influence the risk and emergence of zoonotic disease in humans1,2. However, whether such changes in risk are underpinned by predictable ecological changes remains unclear. It has been suggested that habitat disturbance might cause predictable changes in the local diversity and taxonomic composition of potential reservoir hosts, owing to systematic, trait-mediated differences in species resilience to human pressures3,4. Here we analyse 6,801 ecological assemblages and 376 host species worldwide, controlling for research effort, and show that land use has global and systematic effects on local zoonotic host communities. Known wildlife hosts of human-shared pathogens and parasites overall comprise a greater proportion of local species richness (18–72% higher) and total abundance (21–144% higher) in sites under substantial human use (secondary, agricultural and urban ecosystems) compared with nearby undisturbed habitats. The magnitude of this effect varies taxonomically and is strongest for rodent, bat and passerine bird zoonotic host species, which may be one factor that underpins the global importance of these taxa as zoonotic reservoirs. We further show that mammal species that harbour more pathogens overall (either human-shared or non-human-shared) are more likely to occur in human-managed ecosystems, suggesting that these trends may be mediated by ecological or life-history traits that influence both host status and tolerance to human disturbance5,6. Our results suggest that global changes in the mode and the intensity of land use are creating expanding hazardous interfaces between people, livestock and wildlife reservoirs of zoonotic disease

    The Upper Limit for CH4 in the Protostellar Disk toward HL Tauri

    Get PDF
    We used high-resolution infrared spectra of the heavily embedded T Tauri star HL Tau to search for evidence of absorption due to the R0, R1, and R2 gas-phase CH4 ν3 lines near 3.3 μm. From this, we report a 3 σ upper limit of 1.3 × 1015 cm-2 for the CH4 gas column density toward HL Tau. Our results are compared to those found for CO gas toward this source and to the recent model for chemistry in the inner (10 AU) disks around T Tauri stars by Markwick et al. We find that the upper limit of methane ice+gas column density toward HL Tau, when compared to CO, is somewhat lower than but consistent with that measured toward other interstellar sources (~1%) but that it is much lower than that predicted in the Markwick et al. model and much less than the CH4/CO ratio (10%-80%) found in cometary volatiles. This has important implications for the processing of interstellar material and its incorporation into planetary bodies

    Effects of salt water on the ballistic protective performance of bullet-resistant body armour

    Get PDF
    Bullet-resistant body armour is used by law enforcement agencies and military personnel worldwide, often in inclement weather. Some fibre types used in body armour perform poorly when wet, resulting in a reduced level of protection; this is why most body armour protective elements are water-repellent treated and/or protected by a water-resistant cover. Some of the users operate in the maritime environment. The effect of salt water on body armour performance has not been previously reported. In this work the effect of soaking body armour in salt water and exposing body armour for up to 10 soaking and drying cycles in salt water was investigated. The effectiveness of the water-resistant cover was investigated by considering three cover conditions: (i) intact, (ii) cut and (iii) removed. Wet armour was heavier and provided significantly less protection from 9 mm Luger FMJ ammunition when compared to not-exposed armour irrespective of cover condition. A degradation in performance of armours exposed to soaking and drying cycles was noted, but this was similar across all regimes considered (one, three, five and ten cycles) and not as great as for wet armours

    CO and H+3 Toward MWC 1080, MWC 349, and LkHα 101

    Get PDF
    We present high-resolution, near-infrared NIRSPEC observations of the fundamental rovibrational CO and H+ 3 R(1,0), R(1,1) u , and Q(1,0) transitions toward three early-type young stars: MWC 1080, MWC 349, and LkHα 101. These observations were performed for the purpose of constraining the physical characteristics of the interstellar material along each line of sight. Toward MWC 1080, we detected strong CO absorption and determined a column density upper limit of 1.4 × 1014 cm–2 for H+ 3. We infer that there is very little diffuse material along the line of sight toward MWC 1080 and that the CO absorption is consistent with an origin in the dispersing natal cloud. We detected both cold CO and H+ 3 toward MWC 349, consistent with a diffuse cloud origin. Similarly, both CO and H+ 3 were detected toward LkHα 101. Using a recently revised value for the cosmic ray ionization rate, we conclude that the CO absorption is consistent with a dense cloud origin while the H+ 3 could originate in either the dense or diffuse interstellar medium. We also find no evidence for CO fractionation toward LkHα 101 as reported by Goto et al

    Post-Outburst Infrared Spectra of V1647 Ori, the Illuminating Star of McNeil\u27s Nebula

    Get PDF
    V1647 Ori is a low mass star in the L1630 star-forming region that underwent an outburst in late 2003/early 2004. We present post-outburst infrared spectra obtained with NIRSPEC (Keck II) and SpeX (IRTF) and compare these to spectra taken during the outburst. The results show that the temperature of the hot CO formed in the inner part of the disk has declined by ~800 K, while the water and CO ice and low-J CO gas features remained unchanged, consistent with previous assertions that the latter, low-temperature features arise in the foreground cloud. The P-Cygni profiles of the Paschen series that were present in the outburst spectra taken in March 2004 disappeared by late 2004. The equivalent width of the helium absorption line at 1.0830 µm decreased from 8.9 Å to 3.9 Å between March and November 2004, evidence that the hot, fast wind has decreased substantially. We discuss the implications for categorizing V1647 Ori among the known classes of outbursting young stars

    A champion-driven pathway towards quality improvement in the medical management of osteoporotic fractures

    Get PDF
    The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Tim Yu-Ting Lu, Jennifer A Pink, Lauren E Whitten, Catherine L Hill, Robert J Adams and Catherine Gib
    corecore