128 research outputs found

    The quest for sustained multiple morbidity reduction in very low-birth-weight infants: the Antifragility project.

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    OBJECTIVE: Can a comprehensive, explicitly directive evidence-based guideline for all therapies that might affect the major morbidities of very low-birth-weight (VLBW) infants help a neonatal intensive care unit (NICU) further improve generally favorable morbidity rates? Can Antifragility principles of provider adaptive growth from stressors, enhanced infant risk assessment and adherence to effective therapies minimize unproven treatments and reduce all morbidities? STUDY DESIGN: Prospectively planned observational trial in VLBW infants: control group born October 2011 to September 2013 and study group October 2013 to September 2015. Multi-disciplinary evidence-based review assigned all NICU treatments into one of four distinct categories: (1) always employ this therapy for VLBW infants, (2) never use this therapy, (3) employ this questionable therapy thoughtfully, only in certain circumstances and (4) this therapy has insufficient evidence of efficacy and safety. Extensive staff education emphasized evidence-based potentially better practice (PBP) selection with compliance checks, appreciation of intertwined co-morbidities and prioritizing infant risk reduction strategies. RESULTS: Control included 221 infants, mean (s.d.) age 29 (2.6) weeks, birth weight 1129 (257) g and Study included 197 infants, 29 (2.7) weeks, 1093 (292) g. One hundred and four distinct therapies were placed into categories 1 to 4, with 32 specific compliance checks. Overall mean compliance with the process checks during the second era was 70%, high: 100% (exclusive breast milk use), low: 24% (correct pulse oximetry alarm settings). Morbidity and mortality rates did not significantly change during the second era. CONCLUSIONS: In our NICU with favorable morbidity rates, an expanded effort using a comprehensive therapy guideline for VLBW infants did not further improve outcomes. We need deeper understanding of continuous quality improvement (CQI) fundamentals, therapy compliance, co-morbidity relationships and enhanced sensitivity of risk assessment. Our innovative Antifragility PBP guideline could be useful to other NICUs seeking improvement in VLBW infant morbidities, as we offer a reasoned and concise template of a broad array of therapies categorized efficiently for transparency and review, designed to enhance responsible CQI decision-making

    Automated Determination of Stellar Parameters from Simulated Dispersed Images for DIVA

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    We have assessed how well stellar parameters (T_eff, logg and [Fe/H]) can be retrieved from low-resolution dispersed images to be obtained by the DIVA satellite. Although DIVA is primarily an all-sky astrometric mission, it will also obtain spectrophotometric information for about 13 million stars (operational limiting magnitude V ~ 13.5 mag). Constructional studies foresee a grating system yielding a dispersion of ~200nm/mm on the focal plane (first spectral order). For astrometric reasons there will be no cross dispersion which results in the overlapping of the first to third diffraction orders. The one-dimensional, position related intensity function is called a DISPI (DISPersed Intensity). We simulated DISPIS from synthetic spectra (...) for a limited range of metallicites i.e. our results are for [Fe/H] in the range -0.3 to 1 dex. We show that there is no need to deconvolve these low resolution signals in order to obtain basic stellar parameters. Using neural network methods and by including simulated data of DIVA's UV telescope, we can determine T_eff to an average accuracy of about 2% for DISPIS from stars with 2000 K < T_eff < 20000 K and visual magnitudes of V=13 mag (end of mission data). logg can be determined for all temperatures with an accuracy better than 0.25 dex for magnitudes brighter than V=12 mag. For low temperature stars with 2000 K < T_eff < 5000 K and for metallicities in the range -0.3 to +1 dex a determination of [Fe/H] is possible (to better than 0.2 dex) for these magnitudes. Additionally we examined the effects of extinction E(B-V) on DISPIS and found that it can be determined to better than 0.07 mag for magnitudes brighter than V=14 mag if the UV information is included.Comment: 12 pages, 8 figures, Accepted for publication in A&

    Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

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    We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

    A fine balance of synaptophysin levels underlies efficient retrieval of synaptobrevin II to synaptic vesicles

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    Synaptobrevin II (sybII) is a vesicular soluble NSF attachment protein receptor (SNARE) protein that is essential for neurotransmitter release, and thus its correct trafficking to synaptic vesicles (SVs) is critical to render them fusion competent. The SV protein synaptophysin binds to sybII and facilitates its retrieval to SVs during endocytosis. Synaptophysin and sybII are the two most abundant proteins on SVs, being present in a 1:2 ratio. Synaptophysin and sybII are proposed to form a large multimeric complex, and the copy number of the proteins in this complex is also in a 1:2 ratio. We investigated the importance of this ratio between these proteins for the localisation and trafficking of sybII in central neurons. SybII was overexpressed in mouse hippocampal neurons at either 1.6 or 2.15-2.35-fold over endogenous protein levels, in the absence or presence of varying levels of synaptophysin. In the absence of exogenous synaptophysin, exogenous sybII was dispersed along the axon, trapped on the plasma membrane and retrieved slowly during endocytosis. Co-expression of exogenous synaptophysin rescued all of these defects. Importantly, the expression of synaptophysin at nerve terminals in a 1:2 ratio with sybII was sufficient to fully rescue normal sybII trafficking. These results demonstrate that the balance between synaptophysin and sybII levels is critical for the correct targeting of sybII to SVs and suggests that small alterations in synaptophysin levels might affect the localisation of sybII and subsequent presynaptic performance

    Double standards in US warfare: Exploring the historical legacy of civilian protection and the complex nature of the moral-legal nexus

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    This article investigates how – by breaking with the historical double standards regarding civilian protection in conflicts – by the end of the twentieth century, US warfare has come to comply with International Humanitarian Law (IHL). Yet, civilians are still being killed. This has sparked controversies over what constitutes legitimate targeting practices and as to whether higher levels of civilian protection could be achieved. Through an engagement with these debates, including an exploration of the evolution of the norm of non-combatant immunity with specific reference to US warfare, the article argues that IHL does not provide fully satisfactory answers to these issues as it is too permissive in relation to the killing of civilians. The article proposes that more stringent moral guidelines, such as those underpinning the idea of ‘due care’, have the potential to go much further in providing protection for the innocent in war

    THE DIGITAL DIVIDE: Scarcity, inequality and conflict (Last Moyo) Case study: Virtual wars

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    Sousveilling the ‘Global War on Terror’

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    This article theorises what it means to challenge official regimes of surveillance in the War on Terror by further developing the notion of ‘sousveillance’. In particular, we focus on the performative dimension of surveillance by attending to its sites of struggle, particularly where alternative and counter-performances work to disrupt and dislodge official regimes of vision. These potent counter-performances have become important flashpoints for discussion in the ongoing negotiation of security state power since the onset of the War on Terror. The article begins by considering what it means to call surveillance ‘performative’ and how such official performances have had a documented chilling effect on free expression and democratic deliberation. It continues by exploring Steve Mann’s notion of ‘sousveillance’, or the view from below, as a theoretical resource for understanding counter-visual performances that otherwise challenge authoritarian surveillant practices. Finally, the article illustrates these dynamics through a number of sousveillant performances that have provoked new deliberative spaces in the context of the War on Terror. © 2019, © 2019 Australian Institute of International Affairs
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