802 research outputs found
A five year epidemiology and cost analysis of electrical injuries sustained following copper theft at a welsh centre for burns and plastic surgery
Advanced transport operating system software upgrade: Flight management/flight controls software description
The Flight Management/Flight Controls (FM/FC) software for the Norden 2 (PDP-11/70M) computer installed on the NASA 737 aircraft is described. The software computes the navigation position estimates, guidance commands, those commands to be issued to the control surfaces to direct the aircraft in flight based on the modes selected on the Advanced Guidance Control System (AGSC) mode panel, and the flight path selected via the Navigation Control/Display Unit (NCDU)
Recent Decisions
Comments on recent decisions by Joseph N. Low, Robert A. Stewart, William M. Dickson, Edward G. Coleman, James F. O\u27Rieley, James J. Haranzo, Robert C. Enburg, E. Milton Farley III, Jerome A. Kolenda, Bernard James McGraw, Joseph C. Spalding, R. Emmett Fitzgerald, Joseph T. Helling, John F. Laughlin, Andrew V. Giorgi, and Jack Fena
Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka B.P
There is much uncertainty surrounding the mechanisms that forced the abrupt climate fluctuations found in many palaeoclimate records during Marine Isotope Stage (MIS)-3. One of the processes thought to be involved in these events is the Atlantic Meridional Overturning Circulation (MOC), which exhibited large changes in its dominant mode throughout the last glacial period. Giant piston core MD95-2006 from the northeast Atlantic Ocean records a suite of palaeoceanographic proxies related to the activity of both surface and deep water masses through a period of MIS-3 when abrupt climate fluctuations were extremely pronounced. A two-stage progression of surface water warming during interstadial warm events is proposed, with initial warming related to the northward advection of a thin warm surface layer within the North Atlantic Current, which only extended into deeper surface layers as the interstadial progressed. Benthic foraminifera isotope data also show millennial-scale oscillations but of a different structure to the abrupt surface water changes. These changes are argued to partly be related to the influence of low-salinity deepwater brines. The influence of deepwater brines over the site of MD95-2006 reached a maximum at times of rapid warming of surface waters. This observation supports the suggestion that brine formation may have helped to destabilize the accumulation of warm, saline surface waters at low latitudes, helping to force the MOC into a warm mode of operation. The contribution of deepwater brines relative to other mechanisms proposed to alter the state of the MOC needs to be examined further in future studies
Triggered Star Formation in a Massive Galaxy at z=3.8: 4C41.17
Spectropolarimetric observations obtained with the W. M. Keck Telescope of
the z=3.8 radio galaxy 4C41.17 show that the UV continuum emission from this
galaxy, which is aligned with the radio axis, is unpolarized (P[2sigma] <
2.4%). This implies that scattered AGN light, which is generally the dominant
contributor to the rest-frame UV emission in z~1 radio galaxies, is unlikely to
be a major component of the UV flux from 4C41.17. The spectrum shows absorption
lines that are similar to those detected in the spectra of the recently
discovered population of star forming galaxies at z~2-3. A galaxian outflow may
contribute partially to the low ionization absorption lines; however, the high
velocity wings of the high ionization lines are unlikely to be dominated by a
galaxian wind since the implied outflow mass is very large. The detection of
stellar absorption lines, the shape of the SiIV profile, the unpolarized
continuum, the inability of any AGN-related processes to account for the UV
flux, and the similarity of the UV continuum spectra of 4C41.17 and the nearby
starburst region NGC 1741B1 suggest that the UV light in 4C41.17 is dominated
by young stars. If so, the implied star-formation rate is roughly
140-1100Msun/yr. We discuss the possibility that star formation in 4C41.17 was
triggered by the radio source. Our data are consistent with the hypothesis that
4C41.17 is undergoing its major epoch of star formation at z~4, and that by z~1
it will have evolved to have spectral and morphological properties similar to
those observed in known z~1 powerful radio galaxies.Comment: 28 pages (Latex text + figures); Accepted for publication in The
Astrophysical Journal (Dec 1, 1997 issue
The first NINDS/NIBIB consensus meeting to define neuropathological criteria for the diagnosis of chronic traumatic encephalopathy.
Chronic traumatic encephalopathy (CTE) is a neurodegeneration characterized by the abnormal accumulation of hyperphosphorylated tau protein within the brain. Like many other neurodegenerative conditions, at present, CTE can only be definitively diagnosed by post-mortem examination of brain tissue. As the first part of a series of consensus panels funded by the NINDS/NIBIB to define the neuropathological criteria for CTE, preliminary neuropathological criteria were used by 7 neuropathologists to blindly evaluate 25 cases of various tauopathies, including CTE, Alzheimer's disease, progressive supranuclear palsy, argyrophilic grain disease, corticobasal degeneration, primary age-related tauopathy, and parkinsonism dementia complex of Guam. The results demonstrated that there was good agreement among the neuropathologists who reviewed the cases (Cohen's kappa, 0.67) and even better agreement between reviewers and the diagnosis of CTE (Cohen's kappa, 0.78). Based on these results, the panel defined the pathognomonic lesion of CTE as an accumulation of abnormal hyperphosphorylated tau (p-tau) in neurons and astroglia distributed around small blood vessels at the depths of cortical sulci and in an irregular pattern. The group also defined supportive but non-specific p-tau-immunoreactive features of CTE as: pretangles and NFTs affecting superficial layers (layers II-III) of cerebral cortex; pretangles, NFTs or extracellular tangles in CA2 and pretangles and proximal dendritic swellings in CA4 of the hippocampus; neuronal and astrocytic aggregates in subcortical nuclei; thorn-shaped astrocytes at the glial limitans of the subpial and periventricular regions; and large grain-like and dot-like structures. Supportive non-p-tau pathologies include TDP-43 immunoreactive neuronal cytoplasmic inclusions and dot-like structures in the hippocampus, anteromedial temporal cortex and amygdala. The panel also recommended a minimum blocking and staining scheme for pathological evaluation and made recommendations for future study. This study provides the first step towards the development of validated neuropathological criteria for CTE and will pave the way towards future clinical and mechanistic studies
Criteria for the diagnosis of corticobasal degeneration
Current criteria for the clinical diagnosis of pathologically confirmed corticobasal degeneration (CBD) no longer reflect the expanding understanding of this disease and its clinicopathologic correlations. An international consortium of behavioral neurology, neuropsychology, and movement disorders specialists developed new criteria based on consensus and a systematic literature review. Clinical diagnoses (early or late) were identified for 267 nonoverlapping pathologically confirmed CBD cases from published reports and brain banks. Combined with consensus, 4 CBD phenotypes emerged: corticobasal syndrome (CBS), frontal behavioral-spatial syndrome (FBS), nonfluent/agrammatic variant of primary progressive aphasia (naPPA), and progressive supranuclear palsy syndrome (PSPS). Clinical features of CBD cases were extracted from descriptions of 209 brain bank and published patients, providing a comprehensive description of CBD and correcting common misconceptions. Clinical CBD phenotypes and features were combined to create 2 sets of criteria: more specific clinical research criteria for probable CBD and broader criteria for possible CBD that are more inclusive but have a higher chance to detect other tau-based pathologies. Probable CBD criteria require insidious onset and gradual progression for at least 1 year, age at onset ≥50 years, no similar family history or known tau mutations, and a clinical phenotype of probable CBS or either FBS or naPPA with at least 1 CBS feature. The possible CBD category uses similar criteria but has no restrictions on age or family history, allows tau mutations, permits less rigorous phenotype fulfillment, and includes a PSPS phenotype. Future validation and refinement of the proposed criteria are needed
IP6 is an HIV pocket factor that prevents capsid collapse and promotes DNA synthesis.
The HIV capsid is semipermeable and covered in electropositive pores that are essential for viral DNA synthesis and infection. Here, we show that these pores bind the abundant cellular polyanion IP6, transforming viral stability from minutes to hours and allowing newly synthesised DNA to accumulate inside the capsid. An arginine ring within the pore coordinates IP6, which strengthens capsid hexamers by almost 10°C. Single molecule measurements demonstrate that this renders native HIV capsids highly stable and protected from spontaneous collapse. Moreover, encapsidated reverse transcription assays reveal that, once stabilised by IP6, the accumulation of new viral DNA inside the capsid increases >100 fold. Remarkably, isotopic labelling of inositol in virus-producing cells reveals that HIV selectively packages over 300 IP6 molecules per infectious virion. We propose that HIV recruits IP6 to regulate capsid stability and uncoating, analogous to picornavirus pocket factors. HIV-1/IP6/capsid/co-factor/reverse transcription
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