166 research outputs found
Predictors of outcome of prematurely born infants with pulmonary interstitial emphysema
Aim: To determine how oxygenation, ventilation efficiency and tidal volume requirements changed with the development of pulmonary interstitial emphysema (PIE) and whether in affected patients a composite gas exchange index predicted death or bronchopulmonary dysplasia (BPD). Methods: Infants who developed PIE from 2010 to 2016 were identified. The oxygenation index (OI), ventilation efficiency index (VEI), ventilation to perfusion ratio and inspiratory tidal volume were calculated before radiological evidence of PIE (pre-PIE) and at the worst PIE radiographic appearance (PIE-worst). Results: Thirty infants, median (IQR) gestational age of 24.6 (24.3–26.7) weeks were assessed. Their age at pre-PIE was 11 (6–19) days and 23 (13–42) days at PIE-worst. Compared to pre-PIE, at PIE-worst, the OI was higher [14.5 (10.7–19.2) vs 4.8 (3.1–6.1), respectively, p 11.4 at PIE-worst predicted death or BPD with 80% sensitivity and 100% specificity. Conclusion: Development of PIE was associated with poorer oxygenation and ventilation efficiency despite increased tidal volumes. The OI at PIE-worst predicted death or BPD
Transition to turbulence and effect of initial conditions on three-dimensional compressible mixing in planar blast-wave-driven systems
Perturbations on an interface driven by a strong blast wave grow in time due to a combination of Rayleigh–Taylor, Richtmyer–Meshkov, and decompression effects. In this paper, results from three-dimensional (3D) numerical simulations of such a system under drive conditions to be attainable on the National Ignition Facility [E. M. Campbell, Laser Part. Beams 9, 209 (1991)] are presented. Using the multiphysics, adaptive mesh refinement, higher order Godunov Eulerian hydrocode, Raptor [L. H. Howell and J. A. Greenough, J. Comput. Phys. 184, 53 (2003)], the late nonlinear instability evolution, including transition to turbulence, is considered for various multimode perturbation spectra. The 3D post-transition state differs from the 2D result, but the process of transition proceeds similarly in both 2D and 3D. The turbulent mixing transition results in a reduction in the growth rate of the mixing layer relative to its pretransition value and, in the case of the bubble front, relative to the 2D result. The post-transition spike front velocity is approximately the same in 2D and 3D. Implications for hydrodynamic mixing in core-collapse supernovae are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87764/2/056317_1.pd
Preliminary assessment of fluorine-18 fluorodeoxyglucose positron mission tomography in patients with bladder cancer
The purpose of this study was to assess the feasibility of imaging of bladder cancer with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scanning. We studied 12 patients with histologically proven bladder cancer who had undergone surgical procedures and/or radiotherapy. Retrograde irrigation of the urinary bladder with 1000–3710 ml saline was performed during nine of the studies. Dynamic and static PET images were obtained, and standardized uptake value images were reconstructed. FDG-PET scanning was true-positive in eight patients (66.7%), but false-negative in four (33.3%). Of 20 organs with tumor mass lesions confirmed pathologically or clinically, 16 (80%) were detected by FDG-PET scanning. FDG-PET scanning detected all of 17 distant metastatic lesions and two of three proven regional lymph node metastases. FDG-PET was also capable of differentiating viable recurrent bladder cancer from radiation-induced alterations in two patients. In conclusion, these preliminary data indicate the feasibility of FDG-PET imaging in patients with bladder cancer, although a major remaining pitfall is intense FDG accumulation in the urine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46842/1/259_2004_Article_BF00841398.pd
‘It Takes Two Hands to Clap’: How Gaddi Shepherds in the Indian Himalayas Negotiate Access to Grazing
This article examines the effects of state intervention on the workings of informal institutions that coordinate the communal use and management of natural resources. Specifically it focuses on the case of the nomadic Gaddi
shepherds and official attempts to regulate their access to grazing pastures in the Indian Himalayas. It is often predicted that the increased presence of the modern state critically undermines locally appropriate and community-based resource management arrangements. Drawing on the work of Pauline Peters and Francis Cleaver, I identify key instances of socially embedded ‘common’ management institutions and explain the evolution of these arrangements
through dynamic interactions between individuals, communities and the agents of the state. Through describing the ‘living space’ of Gaddi shepherds across the annual cycle of nomadic migration with their flocks I explore the
ways in which they have been able to creatively reinterpret external interventions, and suggest how contemporary arrangements for accessing pasture at different moments of the annual cycle involve complex combinations of the
formal and the informal, the ‘traditional’ and the ‘modern’
Observation of collapsing radiative shocks in laboratory experiments
This article reports the observation of the dense, collapsed layer produced by a radiative shock in a laboratory experiment. The experiment uses laser irradiation to accelerate a thin layer of solid-density material to above 100 km/s100km∕s, the first to probe such high velocities in a radiative shock. The layer in turn drives a shock wave through a cylindrical volume of Xe gas (at ∼ 6 mg/cm3∼6mg∕cm3). Radiation from the shocked Xe removes enough energy that the shocked layer increases in density and collapses spatially. This type of system is relevant to a number of astrophysical contexts, providing the potential to observe phenomena of interest to astrophysics and to test astrophysical computer codes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87760/2/082901_1.pd
Neutralizing Antibody Fails to Impact the Course of Ebola Virus Infection in Monkeys
Prophylaxis with high doses of neutralizing antibody typically offers protection against challenge with viruses producing acute infections. In this study, we have investigated the ability of the neutralizing human monoclonal antibody, KZ52, to protect against Ebola virus in rhesus macaques. This antibody was previously shown to fully protect guinea pigs from infection. Four rhesus macaques were given 50 mg/kg of neutralizing human monoclonal antibody KZ52 intravenously 1 d before challenge with 1,000 plaque-forming units of Ebola virus, followed by a second dose of 50 mg/kg antibody 4 d after challenge. A control animal was exposed to virus in the absence of antibody treatment. Passive transfer of the neutralizing human monoclonal antibody not only failed to protect macaques against challenge with Ebola virus but also had a minimal effect on the explosive viral replication following infection. We show that the inability of antibody to impact infection was not due to neutralization escape. It appears that Ebola virus has a mechanism of infection propagation in vivo in macaques that is uniquely insensitive even to high concentrations of neutralizing antibody
Health effects of indoor air quality on children and young people
Air pollution is the environmental public health problem of our time. The United Nations Convention on the Rights of the Child sets out clear guidance to protecting the rights of children and young people, including a child's right to the best possible health (Article 24) and the right to a good standard of living. Unicef also consider that clean air is a right for all children. The UK Royal Medical Colleges vigorously advocate for a healthy environment at the population level and in local communities, especially where socio-economic circumstances limit the choice of where people can live, and which school children attend. Despite substantial progress in understanding outdoor air pollution, the potential risk to health, especially that of children and young people, from the indoor air has been largely overlooked, yet in modern times, the indoor environment has never been more important as lockdown with the Covi-19 virus pandemic has shown us. Here we provide an abridged version of the RCPCH/RCP Report The inside story: Health effects of indoor air quality on children and young people but without the section on recommendations. The full Report along with recommendations, released on 28 January 2020, can be accessed at https://www.rcpch.ac.uk/resources/inside-story-health-effects-indoor-air-quality-children-young-people. While we recognise that some aspects of this commentary are UK specific, much of the content has wide implication
Dancing with death. A historical perspective on coping with covid-19
In this paper, we address the question on how societies coped with pandemic crises, how they tried to control or adapt to the disease, or even managed to overcome the death trap in history. On the basis of historical research, we describe how societies in the western world accommodated to or exited hardship and restrictive measures over the course of the last four centuries. In particular, we are interested in how historically embedded citizens' resources were directed towards living with and to a certain extent accepting the virus. Such an approach of “applied history” to the management of crises and public hazards, we believe, helps address today's pressing question of what adaptive strategies can be adopted to return to a normalized life, including living with socially acceptable medical, hygienic and other pandemic‐related measures
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