147 research outputs found

    Evidence for Cold Accretion: Primitive Gas Flowing onto a Galaxy at z~0.274

    Full text link
    We present UV and optical observations from the Cosmic Origins Spectrograph on the Hubble Space Telescope and Keck of a z= 0.27395 Lyman limit system (LLS) seen in absorption against the QSO PG1630+377. We detect H I absorption with log N(HI)=17.06\pm0.05 as well as Mg II, C III, Si III, and O VI in this system. The column densities are readily explained if this is a multi-phase system, with the intermediate and low ions arising in a very low metallicity ([Mg/ H] =-1.71 \pm 0.06) photoionized gas. We identify via Keck spectroscopy and Large Binocular Telescope imaging a 0.3 L_* star-forming galaxy projected 37 kpc from the QSO at nearly identical redshift (z=0.27406, \Delta v = -26 \kms) with near solar metallicity ([O/ H]=-0.20 \pm 0.15). The presence of very low metallicity gas in the proximity of a near-solar metallicity, sub-L_* galaxy strongly suggests that the LLS probes gas infalling onto the galaxy. A search of the literature reveals that such low metallicity LLSs are not uncommon. We found that 50% (4/8) of the well-studied z < 1 LLSs have metallicities similar to the present system and show sub-L_* galaxies with rho < 100 kpc in those fields where redshifts have been surveyed. We argue that the properties of these primitive LLSs and their host galaxies are consistent with those of cold mode accretion streams seen in galaxy simulations.Comment: Accepted for publication in the Astrophysical Journa

    Implementation and Conduct of Therapeutic Hypothermia for Perinatal Asphyxial Encephalopathy in the UK – Analysis of National Data

    Get PDF
    BACKGROUND: Delay in implementing new treatments into clinical practice results in considerable health and economic opportunity costs. Data from the UK TOBY Cooling Register provides the opportunity to examine how one new effective therapy for newborn infants suspected of suffering asphyxial encephalopathy--therapeutic hypothermia- was implemented in the UK. METHODOLOGY/PRINCIPAL FINDINGS: We analysed returned data forms from inception of the Register in December 2006 to the end of July 2011. Data forms were received for 1384 (67%) of the 2069 infants registered. The monthly rate of notifications increased from median {IQR} 18 {15-31} to 33 {30-39} after the announcement of the results of the recent TOBY trial, and to 50 {36-55} after their publication. This rate further increased to 70 {64-83} following official endorsement of the therapy, and is now close to the expected numbers of eligible infants. Cooling was started at 3.3 {1.5-5.5} hours after birth and the time taken to achieve the target 33-34 °C rectal temperature was 1 {0-3} hours. The rectal temperature was in the target range in 83% of measurements. From 2006 to 2011 there was evidence of extension of treatment to slightly less severely affected infants. 278 of 1362 (20%) infants died at 2.9 {1.4-4.1} days of age. The rates of death fell slightly over the period of the Register and, at two years of age cerebral palsy was diagnosed in 22% of infants; half of these were spastic bilateral. Factors independently associated with adverse outcome were clinical seizures prior to cooling (p&lt;0.001) and severely abnormal amplitude integrated EEG (p&lt;0.001). CONCLUSIONS/SIGNIFICANCE: Therapeutic hypothermia was implemented appropriately within the UK, with significant benefit to patients and the health economy. This may be due in part to participation by neonatal units in clinical trials, the establishment of the national Register, and its endorsement by advisory bodies

    Challenges in Australian policy processes for disinvestment from existing, ineffective health care practices

    Get PDF
    Background Internationally, many health care interventions were diffused prior to the standard use of assessments of safety, effectiveness and cost-effectiveness. Disinvestment from ineffective or inappropriately applied practices is a growing priority for health care systems for reasons of improved quality of care and sustainability of resource allocation. In this paper we examine key challenges for disinvestment from these interventions and explore potential policy-related avenues to advance a disinvestment agenda. Results We examine five key challenges in the area of policy driven disinvestment: 1) lack of resources to support disinvestment policy mechanisms; 2) lack of reliable administrative mechanisms to identify and prioritise technologies and/or practices with uncertain clinical and cost-effectiveness; 3) political, clinical and social challenges to removing an established technology or practice; 4) lack of published studies with evidence demonstrating that existing technologies/practices provide little or no benefit (highlighting complexity of design) and; 5) inadequate resources to support a research agenda to advance disinvestment methods. Partnerships are required to involve government, professional colleges and relevant stakeholder groups to put disinvestment on the agenda. Such partnerships could foster awareness raising, collaboration and improved health outcome data generation and reporting. Dedicated funds and distinct processes could be established within the Medical Services Advisory Committee and Pharmaceutical Benefits Advisory Committee to, a) identify technologies and practices for which there is relative uncertainty that could be the basis for disinvestment analysis, and b) conduct disinvestment assessments of selected item(s) to address existing practices in an analogous manner to the current focus on new and emerging technology. Finally, dedicated funding and cross-disciplinary collaboration is necessary to build health services and policy research capacity, with a focus on advancing disinvestment research methodologies and decision support tools. Conclusion The potential over-utilisation of less than effective clinical practices and the potential under-utilisation of effective clinical practices not only result in less than optimal care but also fragmented, inefficient and unsustainable resource allocation. Systematic policy approaches to disinvestment will improve equity, efficiency, quality and safety of care, as well as sustainability of resource allocation.Adam G Elshaug, Janet E Hiller, Sean R Tunis and John R Mos

    Proteomic and Physiological Responses of Kineococcus radiotolerans to Copper

    Get PDF
    Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II) concentrations (0–1.5 mM) in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II) concentration in the growth medium (R2 = 0.7). Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration

    Dietary iron intake in the first 4 months of infancy and the development of type 1 diabetes: a pilot study

    Get PDF
    <p>Abstract</p> <p>Aims</p> <p>To investigate the impact of iron intake on the development of type 1 diabetes (T1DM).</p> <p>Methods</p> <p>Case-control study with self-administered questionnaire among families of children with T1DM who were less than 10 years old at the time of the survey and developed diabetes between age 1 and 6 years. Data on the types of infant feeding in the first 4 months of life was collected from parents of children with T1DM (n = 128) and controls (n = 67) <10 years old. Because some cases had sibling controls, we used conditional logistic regression models to analyze the data in two ways. First we performed a case-control analysis of all 128 cases and 67 controls. Next, we performed a case-control analysis restricted to cases (n = 59) that had a sibling without diabetes (n = 59). Total iron intake was modeled as one standard deviation (SD) increase in iron intake. The SD for iron intake was 540 mg in the total sample and 539 mg in the restricted sample as defined above.</p> <p>Results</p> <p>The median (min, max) total iron intake in the first 4 months of life was 1159 (50, 2399) mg in T1DM cases and 466 (50, 1224) mg among controls (<it>P </it>< 0.001). For each one standard deviation increase in iron intake, the odds ratio (95% confidence interval) for type 1 diabetes was 2.01 (1.183, 3.41) among all participants (128 cases and 67 controls) while it was 2.26 (1.27, 4.03) in a restricted sample of T1 D cases with a control sibling (59 cases and 59 controls) in models adjusted for birth weight, age at the time of the survey, and birth order.</p> <p>Conclusion</p> <p>In this pilot study, high iron intake in the first 4 months of infancy is associated with T1DM. Whether iron intake is causal or a marker of another risk factor warrants further investigation.</p

    Metal-enriched, subkiloparsec gas clumps in the circumgalactic medium of a faint z = 2.5 galaxy★

    Get PDF
    We report the serendipitous detection of a 0.2 L^*, Lyman-α\alpha emitting galaxy at redshift 2.5 at an impact parameter of 50 kpc from a bright background QSO sightline. A high-resolution spectrum of the QSO reveals a partial Lyman-limit absorption system (NHI=1016.94±0.10N_\mathrm{HI}=10^{16.94\pm0.10} cm2^{-2}) with many associated metal absorption lines at the same redshift as the foreground galaxy. Using photoionization models that carefully treat measurement errors and marginalise over uncertainties in the shape and normalisation of the ionizing radiation spectrum, we derive the total hydrogen column density NH=1019.4±0.3N_\mathrm{H}=10^{19.4\pm0.3} cm2^{-2}, and show that all the absorbing clouds are metal enriched, with Z=0.1Z=0.1-0.6Z0.6 Z_\odot. These metallicities and the system's large velocity width (436436 km\,s1^{-1}) suggest the gas is produced by an outflowing wind. Using an expanding shell model we estimate a mass outflow rate of 5M\sim5 M_\odot\,yr1^{-1}. Our photoionization model yields extremely small sizes (<<100-500 pc) for the absorbing clouds, which we argue are typical of high column density absorbers in the circumgalactic medium (CGM). Given these small sizes and extreme kinematics, it is unclear how the clumps survive in the CGM without being destroyed by hydrodynamic instabilities. The small cloud sizes imply that even state-of-the-art cosmological simulations require more than a 10001000-fold improvement in mass resolution to resolve the hydrodynamics relevant for cool gas in the CGM.Comment: Fixed an incorrect reference to D'Odorico & Petitjean 2001, A&A, 370, 729. Data and code used for the paper are at https://github.com/nhmc/LA

    Tai Chi and vestibular rehabilitation improve vestibulopathic gait via different neuromuscular mechanisms: Preliminary report

    Get PDF
    BACKGROUND: Vestibular rehabilitation (VR) is a well-accepted exercise program intended to remedy balance impairment caused by damage to the peripheral vestibular system. Alternative therapies, such as Tai Chi (TC), have recently gained popularity as a treatment for balance impairment. Although VR and TC can benefit people with vestibulopathy, the degree to which gait improvements may be related to neuromuscular adaptations of the lower extremities for the two different therapies are unknown. METHODS: We examined the relationship between lower extremity neuromuscular function and trunk control in 36 older adults with vestibulopathy, randomized to 10 weeks of either VR or TC exercise. Time-distance measures (gait speed, step length, stance duration and step width), lower extremity sagittal plane mechanical energy expenditures (MEE), and trunk sagittal and frontal plane kinematics (peak and range of linear and angular velocity), were measured. RESULTS: Although gait time-distance measures were improved in both groups following treatment, no significant between-groups differences were observed for the MEE and trunk kinematic measures. Significant within groups changes, however, were observed. The TC group significantly increased ankle MEE contribution and decreased hip MEE contribution to total leg MEE, while no significant changes were found within the VR group. The TC group exhibited a positive relationship between change in leg MEE and change in trunk velocity peak and range, while the VR group exhibited a negative relationship. CONCLUSION: Gait function improved in both groups consistent with expectations of the interventions. Differences in each group's response to therapy appear to suggest that improved gait function may be due to different neuromuscular adaptations resulting from the different interventions. The TC group's improvements were associated with reorganized lower extremity neuromuscular patterns, which appear to promote a faster gait and reduced excessive hip compensation. The VR group's improvements, however, were not the result of lower extremity neuromuscular pattern changes. Lower-extremity MEE increases corresponded to attenuated forward trunk linear and angular movement in the VR group, suggesting better control of upper body motion to minimize loss of balance. These data support a growing body of evidence that Tai Chi may be a valuable complementary treatment for vestibular disorders

    Layer-by-layer technique to developing functional nanolaminate films with antifungal activity

    Get PDF
    The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.The authors acknowledge financial support from FP7 IP project BECOBIOCAP^. M. J. Fabra is recipients of a Juan de la Cierva contract from the Spanish Ministry of Economy and Competitivity. Maria L. Flores-López thanks Mexican Science and Technology Council (CONACyT, Mexico) for PhD fellowship support (CONACyT Grant Number 215499/310847). The author Miguel A. Cerqueira is a recipient of a fellowship (SFRH/BPD/72753/2010) supported by Fundação para a Ciência e Tecnologia, POPH-QREN and FSE (FCT, Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP- 01-0124-FEDER-027462) and the project BBioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,^ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER. The support of EU Cost Action FA0904 is gratefully acknowledged
    corecore