N. E. A. 1903

Envelope labelled N. E. A. 1903, containing cards and a second envelope relating to the National Educational Association

Briefing: UK Ministry of Defence Force Protection Engineering Programme

The Defence Science and Technology Laboratory sponsored, QinetiQ-led Force Protection Engineering Research Programme has two main strands, applied and underpinning research. The underpinning strand is led by Blastech Ltd. One focus of this research is into the response of geomaterials to threat loading. The programme on locally won fill is split into four main characterisation strands: high-stress (GPa) static pressure–volume; medium-rate pressure–volume (split Hopkinson bar); high-rate (flyer plate) pressure–volume; and unifying modelling research at the University of Sheffield, which has focused on developing a high-quality dataset for locally won fill in low and medium strain rates. With the test apparatus at Sheffield well-controlled tests can be conducted at both high strain rate and pseudo-static rates up to stress levels of 1 GPa. The University of Cambridge has focused on using one-dimensional shock experiments to examine high-rate pressure–volume relationships. Both establishments are examining the effect of moisture content and starting density on emergent rate effects. Blastech Ltd has been undertaking carefully controlled fragment impact experiments, within the dataspace developed by the Universities of Sheffield and Cambridge. The data from experiments are unified by the QinetiQ-led modelling team, to predict material behaviour and to derive a scalable locally won fill model for use in any situation

A magánszférához való jog

A szerzők a magánszférához való jog jogrendszerbeli elhelyezésére tesznek kísérletet. Warren és Brandeis cikke az első ebben a tárgyban született jogtudományi tanulmány, publikálására 1890-ben került sor. Az angolszász jog common law rendszerében a magánszférához való jog elismerésére tett javaslatuk a magánszféráról alkotott jogelmélet alapját képezi. A magánszférához való jogot úgy definiálják, mint azt a jogot, hogy az ember egyedül lehessen. Első ízben kerül magyarul az olvasó kezébe a magánszférához való jog diskurzus- megalapozó klasszikusa

Discovery of an ultramassive pulsating white dwarf

We announce the discovery of the most massive pulsating hydrogen-atmosphere (DA) white dwarf (WD) ever discovered, GD 518. Model atmosphere fits to the optical spectrum of this star show it is a 12,030 +/- 210 K WD with a log(g) = 9.08 +/- 0.06, which corresponds to a mass of 1.20 +/- 0.03 Msun. Stellar evolution models indicate that the progenitor of such a high-mass WD endured a stable carbon-burning phase, producing an oxygen-neon-core WD. The discovery of pulsations in GD 518 thus offers the first opportunity to probe the interior of a WD with a possible oxygen-neon core. Such a massive WD should also be significantly crystallized at this temperature. The star exhibits multi-periodic luminosity variations at timescales ranging from roughly 425-595 s and amplitudes up to 0.7%, consistent in period and amplitude with the observed variability of typical ZZ Ceti stars, which exhibit non-radial g-mode pulsations driven by a hydrogen partial ionization zone. Successfully unraveling both the total mass and core composition of GD 518 provides a unique opportunity to investigate intermediate-mass stellar evolution, and can possibly place an upper limit to the mass of a carbon-oxygen-core WD, which in turn constrains SNe Ia progenitor systems.Comment: 5 pages, 3 figures, Astrophysical Journal Letters, 771, L2 (2013

Discovery of pulsations, including possible pressure modes, in two new extremely low mass, He-core white dwarfs

We report the discovery of the second and third pulsating extremely low mass white dwarfs (WDs), SDSS J111215.82+111745.0 (hereafter J1112) and SDSS J151826.68+065813.2 (hereafter J1518). Both have masses < 0.25 Msun and effective temperatures below 10,000 K, establishing these putatively He-core WDs as a cooler class of pulsating hydrogen-atmosphere WDs (DAVs, or ZZ Ceti stars). The short-period pulsations evidenced in the light curve of J1112 may also represent the first observation of acoustic (p-mode) pulsations in any WD, which provide an exciting opportunity to probe this WD in a complimentary way compared to the long-period g-modes also present. J1112 is a Teff = 9590 +/- 140 K and log(g) = 6.36 +/- 0.06 WD. The star displays sinusoidal variability at five distinct periodicities between 1792-2855 s. In this star we also see short-period variability, strongest at 134.3 s, well short of expected g-modes for such a low-mass WD. The other new pulsating WD, J1518, is a Teff = 9900 +/- 140 K and log(g) = 6.80 +/- 0.05 WD. The light curve of J1518 is highly non-sinusoidal, with at least seven significant periods between 1335-3848 s. Consistent with the expectation that ELM WDs must be formed in binaries, these two new pulsating He-core WDs, in addition to the prototype SDSS J184037.78+642312.3, have close companions. However, the observed variability is inconsistent with tidally induced pulsations and is so far best explained by the same hydrogen partial-ionization driving mechanism at work in classic C/O-core ZZ Ceti stars.Comment: 9 pages, 5 figures, accepted to The Astrophysical Journa

Radius constraints from high-speed photometry of 20 low-mass white dwarf binaries

We carry out high-speed photometry on 20 of the shortest-period, detached white dwarf binaries known and discover systems with eclipses, ellipsoidal variations (due to tidal deformations of the visible white dwarf), and Doppler beaming. All of the binaries contain low-mass white dwarfs with orbital periods less than 4 hr. Our observations identify the first eight tidally distorted white dwarfs, four of which are reported for the first time here, which we use to put empirical constraints on the mass-radius relationship for extremely low-mass (<0.30 Msun) white dwarfs. We also detect Doppler beaming in several of these binaries, which confirms the high-amplitude radial-velocity variability. All of these systems are strong sources of gravitational radiation, and long-term monitoring of those that display ellipsoidal variations can be used to detect spin-up of the tidal bulge due to orbital decay.Comment: 14 pages, 5 figures, accepted for publication in The Astrophysical Journa

Universal screening of Tanzanian HIV-infected adult inpatients with the serum cryptococcal antigen to improve diagnosis and reduce mortality: an operational study

Cryptococcal meningitis is a leading cause of death among HIV-infected individuals in sub-Saharan Africa. Recent developments include the availability of intravenous fluconazole, cryptococcal antigen assays and new data to support fluconazole pre-emptive treatment. In this study, we describe the impact of screening HIV-positive adult inpatients with serum cryptococcal antigen (CRAG) at a Tanzanian referral hospital. All adults admitted to the medical ward of Bugando Medical Centre are counseled and tested for HIV. In this prospective cohort study, we consecutively enrolled HIV-positive patients admitted between September 2009 and January 2010. All patients were interviewed, examined and screened with serum CRAG. Patients with positive serum CRAG or signs of meningitis underwent lumbar puncture. Patients were managed according to standard World Health Organization treatment guidelines. Discharge diagnoses and in-hospital mortality were recorded.\ud Of 333 HIV-infected adults enrolled in our study, 15 (4.4%) had confirmed cryptococcal meningitis and 10 of these 15 (66%) died. All patients with cryptococcal meningitis had at least two of four classic symptoms and signs of meningitis: fever, headache, neck stiffness and altered mental status. Cryptococcal meningitis accounted for a quarter of all in-hospital deaths. Despite screening of all HIV-positive adult inpatients with the serum CRAG at the time of admission and prompt treatment with high-dose intravenous fluconazole in those with confirmed cryptococcal meningitis, the in-hospital mortality rate remained unacceptably high. Improved strategies for earlier diagnosis and treatment of HIV, implementation of fluconazole pre-emptive treatment for high-risk patients and acquisition of better resources for treatment of cryptococcal meningitis are needed

Heterotopic ossification after patellar tendon repair in a man with trisomy 8 mosaicism: a case report and literature review

<p>Abstract</p> <p>Introduction</p> <p>Heterotopic ossification is the abnormal formation of lamellar bone in soft tissue. Its presence jeopardizes functional outcome, impairs rehabilitation and increases costs due to subsequent surgical interventions.</p> <p>Case presentation</p> <p>We present a case of a 32-year-old African-American man with trisomy 8 mosaicism who developed severe heterotopic ossification of his right extensor mechanism subsequent to repair of a patellar tendon rupture.</p> <p>Conclusion</p> <p>To the best of our knowledge there are no prior reports of heterotopic ossification as a complication of patellar tendon repair. This case may suggest an association between trisomy 8 mosaicism and increased risk of heterotopic ossification.</p