1,664 research outputs found

    Lumbar puncture for the generalist

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    The safe and successful performance of a lumbar puncture demands a working and yet specific knowledge as well as competency in performance. This review aims to aid understanding of the knowledge framework, the pitfalls and complications of lumbar puncture. It includes special reference to three dimensional relationships, functional anatomy, imaging anatomy, normal variation and living anatomy. A lumbar puncture is a commonly performed procedure for diagnostic and therapeutic purposes. Epidural and spinal anaesthesia, for example, are common in obstetric practice and involve the same technique as a lumbar puncture except for the endpoint of the needle being in the epidural space and subarachnoid space respectively. The procedure is by no means innocuous and some anatomical pitfalls include inability to find the correct entry site for placement of the lumbar puncture needle and lack of awareness of structures in relation to the advancing needle. Headache is the most common complication and it is important to avoid traumatic and dry taps, herniation syndromes and injury to the terminal end of the spinal cord. With a thorough knowledge of the contraindications, the regional anatomy and rationale of the technique and adequate prior skills practice, a lumbar puncture can be performed safely and successfully

    A GBT Survey for HI 21 cm Absorption in the Disks and Halos of Low-Redshift Galaxies

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    We present an HI 21 cm absorption survey with the Green Bank Telescope (GBT) of galaxy-quasar pairs selected by combining data from the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. Our sample consists of 23 sightlines through 15 low-redshift foreground galaxy - background quasar pairs with impact parameters ranging from 1.7 kpc up to 86.7 kpc. We detected one absorber in the GBT survey from the foreground dwarf galaxy, GQ1042+0747, at an impact parameter of 1.7 kpc and another possible absorber in our follow-up Very Large Array (VLA) imaging of the nearby foreground galaxy, UGC 7408. Both of the absorbers are narrow (FWHM of 3.6 and 4.8 km/s), have sub Damped Lyman alpha column densities, and most likely originate in the disk gas of the foreground galaxies. We also detected H I emission from three foreground galaxies, including UGC 7408. Although our sample contains both blue and red galaxies, the two H I absorbers as well as the H I emissions are associated with blue galaxies. We discuss the physical conditions in the 21 cm absorbers and some drawbacks of the large GBT beam for this type of survey.Comment: 15 pages, 6 figures, 3 table

    What are the communication skills and needs of doctors when communicating a poor prognosis to patients and their families? A qualitative study from South Africa

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    Background. Thousands of South Africans are diagnosed with life-threatening illness every year. Research shows that, globally, of the 20 million people who need palliative care at the end of life every year, <10% receive it.Objectives. To explore communication skills and practices of medical practitioners when conveying a poor prognosis to patients and families, and to identify their communication skills, needs and understanding of palliative care.Methods. This was an exploratory qualitative study of practising doctors, using a grounded theory approach. The study was conducted at a government-funded public hospital in Cape Town, South Africa, which is a referral centre for various illnesses, including cancer. Face-toface, one-on-one interviews using a semistructured interview guide were conducted, using audio recording.Results. The emerging theory from this study is that doctors who understand the principles of palliative care and who have an established working relationship with a palliative care team feel supported and express low levels of emotional anxiety when conveying a poor prognosis.Conclusion. Having hospital-based palliative care teams in all public hospitals will provide support for patients and doctors handling difficult conversations. All healthcare professionals should be trained in palliative care so that they can effectively communicate concerns related to poor prognosis with patients and their families. Communication, loss and grief issues should be part of the curriculum in all disciplines and throughout training in medical school

    Metal abundances at z<1.5: new measurements in sub-Damped Lyman-alpha Absorbers

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    Damped Lyman-alpha systems (DLAs) and sub-DLAs seen toward background quasars provide the most detailed probes of elemental abundances. Somewhat paradoxically these measurements are more difficult at lower redshifts due to the atmospheric cut-off, and so a few years ago our group began a programme to study abundances at z < 1.5 in quasar absorbers. In this paper, we present new UVES observations of six additional quasar absorption line systems at z < 1.5, five of which are sub-DLAs. We find solar or above solar metallicity, as measured by the abundance of zinc, assumed not to be affected by dust, in two sub-DLAs: one, towards Q0138-0005 with [Zn/H]=+0.28 +/- 0.16; the other towards Q2335+1501 with [Zn/H]=+0.07 +/- 0.34. Relatively high metallicity was observed in another system: Q0123-0058 with [Zn/H]=-0.45 +/- 0.20. Only for the one DLA in our sample, in Q0449-1645, do we find a low metallicity, [Zn/H]=-0.96 +/- 0.08. We also note that in some of these systems large relative abundance variations from component to component are observed in Si, Mn, Cr and Zn.Comment: 7 figures and 10 tables. Accepted for publication in MNRA

    An apocalyptic agenda for mission in our time

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    Addressing the interest in missional theology and responding to the recent coronavirus disease 2019 (COVID-19) pandemic, this research developed an apocalyptic missional theology for our time. Whilst the Second World War inspired an exploration of the eschatological dimensions of mission, it was argued that apocalyptic theology adds a much needed perspective on mission. In addition to replying to the pandemic, apocalyptic missiology proved to be well suited to speak about the challenges for the Church in South Africa, and introduces African modes of thinking to missiology. This study comprised a qualitative literature research method that traced the history of eschatology and apocalyptic in missional thinking (summarised apocalyptic theology), demonstrated that apocalyptic theology contributes to current missiology, and finally developed an apocalyptic agenda for the mission. The research found that apocalyptic offers new ways of speaking about God that challenges contemporary powers and power structures, and presents prophetic and ethical ways for the church to participate in the Missio Dei. Apocalyptic extends a more universal future that includes all peoples and creation, and it provides believers with a new identity and comfort in our time. In conclusion, apocalyptic theology was found to enrich missional thinking, contributing hope and joy to the Christian message. INTRADISCIPLINARY AND/OR INTERDISCIPLINARY IMPLICATIONS : This article suggested that apocalyptic theology adds new dimensions to missional theology, enriching the traditional discourse. It used the insights of biblical and religious studies, and applied it to missiology, as well as to systematic and practical theology.http://www.ve.org.zaam2021Science of Religion and Missiolog

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

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    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

    Complete homochirality induced by the nonlinear autocatalysis and recycling

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    A nonlinear autocatalysis of a chiral substance is shown to achieve homochirality in a closed system, if the back-reaction is included. Asymmetry in the concentration of two enantiomers or the enantiometric excess increases due to the nonlinear autocatalysis. Furthermore, when the back-reaction is taken into account, the reactant supplied by the decomposition of the enantiomers is recycled to produce more and more the dominant one, and eventually the homochirality is established.Comment: 4 pages, 2 figure
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