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The diffractograms of syn-gypsum and of fine gas desulfurization products indicate that CaSO4.2H2O is converted to other phase(s) when heated to 100°C. Syn-hannebachite (CaSO30.5H2O) is unaffected by similar thermal treatment.
We investigate the Galois structures of
-adic cohomology groups of general
-adic representations over finite extensions of number fields. We show, in particular, that as the field extensions vary over natural families the Galois modules formed by these cohomology groups always decompose as the direct sum of a projective module and a complementary module of bounded
-rank. We use this result to derive new (upper and lower) bounds on the changes in ranks of Selmer groups over extensions of number fields and descriptions of the explicit Galois structures of natural arithmetic modules.
The strong self-damped Lyman α absorption systems present in the spectra of high redshift QSOs represent a unique population of absorber which has recently been associated with the precursors of current disk galaxies. In a low resolution survey for what we have come to call “Lyman α disk systems” performed at Lick Observatory (Wolfe, et al. 1986, Ap. J. Suppl. 61, 249) approximately 18 systems with confirmed damped Lyman α profiles and rest frame equivalent widths greater than 5 Å were detected in a sample of 68 high redshift QSOs (Smith, Cohen and Bradley 1986, Ap. J. 310, 583). Subsequent higher resolution study has shown these systems to have the following properties (Turnshek, et al. 1988, Ap. J., in press):
2.Low-mixed ionization state. Typically the low ionization states dominate the high ionization states (e.g. CII ≫ CIV). Some enrichment has occurred, −2≲[X/H]⊙ ≲0.
3.Gas density, n ≲ 1 cm−3.
4.The gas shows two components, a quiescent (disk) component, σν ≲ 10 km s−1, and a turbulent (halo) component, σν ≲ 20 km s−1. Some systems show only the low velocity dispersion component.
5.At least one system intervening toward a radio QSO (Pks 0458-020) shows 21-cm absorption. The system shows multiple cloud structure with σν ≈ 6 km s−1, Ts ≈ 100 K, and structure extended over several kpc on the sky.
6.There is evidence that these systems may be self gravitating with scale height of the order of 300 pc.
7.These systems represent a unique population of absorber (distinct from the ‘Lyman a forest’ and heavy element systems) covering approximately 20% of the sky to z ≈ 3 and accounting for all of the baryonic matter at that redshift.
In a continuing redshift observation program, we have recently determined or confirmed the redshifts of 32 R ≥ 0 Abell clusters. With these data added to the previously measured cluster redshifts, there is now a sample of Abell clusters to z = 0.085 that is 92% complete in redshift measurements. The sample consists of 225 clusters in the North and South Galactic Caps, with latitude |b| > 30° to minimize obscuration effects. The longitude range 270° < l < 360° was also excluded for this sample because of an apparent large spur of galactic absorption.
The structure within the distribution of rich clusters is described. In particular, the Pisces-Cetus region is shown to contain a dense supercluster, a long filament of galaxies and clusters, and a ring of 12 Abell clusters surrounding a diameter void.
The amount of structure present among the Abell clusters out to redshift z = 0.085 has been compared with numerical supercomputer simulations (with 643 particles) of the isothermal, neutrino, and cold particle models for large-scale structure, assuming a flat universe and H = 50 km sec−1 Mpc−1. High-density clusters of particles were identified in each simulation. Correlation and percolation tests were then used to compare the spatial distribution of these high-density points with the apparent superclustering among Abell clusters. While all of the models had some small superclusters (the neutrino model has too many), none came very close to possessing the extremely extensive structures found in the Abell clusters (generally, disagreement by 2σ or more).
A second set of simulations used the cold particle model with Ω = 0.2 and 0.5. The structures found in these simulations were certainly larger than those of the Ω = 1.0 cold particle case, but still > 2σ too small in comparisons with the Abell clusters.
New VLA observations have revealed sharp gradients in both the depolarization and rotation measure in the lobes of Cen A. We attribute these jumps to a foreground screen in the southern lobe, and to the passage of the jet through a shock in a Malin shell in the northern lobe.
An MHD computation of a restarting jet is presented and compared with observations of classical double radio sources. Assuming ideal MHD and an adiabatic equation of state, it is found that a “partial” jet exists for about 25% of the time, and that the terminal hotspot dissipates quickly compared to other physical time scales once the outflow of the jet is terminated.
The notion of creating artificial vision using visual prostheses has been
well represented though science fiction literature and films. When we think
of retinal prostheses, we immediately think of fictional characters like The
Terminator scanning across a bar to assess patrons for appropriately fitting
clothing, or Star Trek’s Geordi La Forge with his VISOR, a visual
instrument and sensory organ replacement placed across his eyes and attached
into his temples to provide him with vision. Such devices are no longer
farfetched. In the past 20 years, significant research has been undertaken
across the globe in the race for a “Bionic Eye”. Advances in
Bionic Eye research have come from improvements in the design and
fabrication of multielectrode arrays (MEAs) for medical applications. MEAs
are already commonplace in medicine with use in applications such as the
cochlear device, cardiac pacemakers, and deep brain stimulators where
interfacing with neuronal cell populations is required.
The use of MEAs for vision prostheses is currently of significant interest.
For the most part, retinal prostheses have dominated the research landscape
owing to the ease of access and direct contact to the retinal ganglion nerve
cells. However, MEAs are also in use for direct stimulation into the optic
nerve . Retinal prostheses bypass the damaged photoreceptor cells within
the retina and instead replace the degenerate retina with electrical
stimulation to the nerve cells. Using electrical stimulation, stimulated
retinal ganglion cells have been shown to elicit a percept in the form of a
phosphene in blind patients [2–6]. Accordingly, the two diseases
commonly linked to the justification for Bionic Eye research are age-related
macular degeneration (AMD) and retinitis pigmentosa (RP), diseases which
lead to progressive loss of photoreceptor cells and diseases where the
patient has had previous vision and thus exhibits prior visual-brain
pathways. At present, there has been no reliable cure for any of the retinal
diseases that target the photoreceptor cells, and thus the development of
prosthetic devices is a viable clinical treatment option [7–9].
White matter disruptions have been identified in individuals with congenital heart disease (CHD). However, no specific theory-driven relationships between microstructural white matter disruptions and cognition have been established in CHD. We conducted a two-part study. First, we identified significant differences in fractional anisotropy (FA) of emerging adults with CHD using Tract-Based Spatial Statistics (TBSS). TBSS analyses between 22 participants with CHD and 18 demographically similar controls identified five regions of normal appearing white matter with significantly lower FA in CHD, and two higher. Next, two regions of lower FA in CHD were selected to examine theory-driven differential relationships with cognition: voxels along the left uncinate fasciculus (UF; a tract theorized to contribute to verbal memory) and voxels along the right middle cerebellar peduncle (MCP; a tract previously linked to attention). In CHD, a significant positive correlation between UF FA and memory was found, r(20)=.42, p=.049 (uncorrected). There was no correlation between UF and auditory attention span. A positive correlation between MCP FA and auditory attention span was found, r(20)=.47, p=.027 (uncorrected). There was no correlation between MCP and memory. In controls, no significant relationships were identified. These results are consistent with previous literature demonstrating lower FA in younger CHD samples, and provide novel evidence for disrupted white matter integrity in emerging adults with CHD. Furthermore, a correlational double dissociation established distinct white matter circuitry (UF and MCP) and differential cognitive correlates (memory and attention span, respectively) in young adults with CHD. (JINS, 2015, 21, 22–33)
Disparities in access to medical care and outcomes of medical treatment related to insurance status are documented. However, little attention has been given to the effect of health care funding status on outcomes in trauma patients.
This study evaluated if adult trauma patients who arrived by air transport to a trauma center had different clinical outcomes based on their health insurance status.
A retrospective analysis was performed of all adult trauma patients arriving by prehospital flight services to a Level I Trauma Center over a 5-year period. Patients were classified as unfunded or funded based on health insurance status. Injury severity scores (ISS) were compared, while the end points evaluated in the study included duration of stay in the intensive care unit (ICU), duration of hospitalization, and mortality.
A total of 1,877 adult patients met inclusion criteria for the study, with 14% (n = 259) classified as unfunded and 86% (n = 1,618) classified as funded. Unfunded patients compared to funded patients had a significantly lower average ISS (12.82 vs 15.56; P < .001) but a significantly higher mortality rate (16.6% vs 10.7%; P < .01) and a 1.54 relative risk of death (95% CI, 1.136-2.098). Neither mean ICU stay (3.44 days vs 4.98 days; P = .264) nor duration of hospitalization (11.18 days vs 13.34 days; P = .382) was significantly different when controlling for ISS.
Unfunded health insurance status is associated with worse outcomes following less significant injury. Further investigation of baseline health disparities for identification and early intervention may improve outcomes. Additionally, these findings may have implications for the health systems of other countries that lack universal health care coverage.
GurienLA, ChesireDJ, KoonceSL, BurnsJBJr. An Evaluation of Trauma Outcomes Related to Insurance Status in Patients Requiring Prehospital Helicopter Transport. Prehosp Disaster Med. 2014;29(6):1-4.
This article is an executive summary of a report from the Centers for Disease Control and Prevention Ventilator-Associated Pneumonia Surveillance Definition Working Group, entitled “Developing a new, national approach to surveillance for ventilator-associated events” and published in Critical Care Medicine. The full report provides a comprehensive description of the Working Group process and outcome.
In September 2011, the Centers for Disease Control and Prevention (CDC) convened a Ventilator-Associated Pneumonia (VAP) Surveillance Definition Working Group to organize a formal process for leaders and experts of key stakeholder organizations to discuss the challenges of VAP surveillance definitions and to propose new approaches to VAP surveillance in adult patients (Table 1).
Using Burgers’ equation with mixed Neumann–Dirichlet boundary conditions, we highlight a
problem that can arise in the numerical approximation of nonlinear dynamical systems on
computers with a finite precision floating point number system. We describe the dynamical
system generated by Burgers’ equation with mixed boundary conditions, summarize some of
its properties and analyze the equilibrium states for finite dimensional dynamical systems
that are generated by numerical approximations of this system. It is important to note
that there are two fundamental differences between Burgers’ equation with mixed
Neumann–Dirichlet boundary conditions and Burgers’ equation with both Dirichlet boundary
conditions. First, Burgers’ equation with homogenous mixed boundary conditions on a finite
interval cannot be linearized by the Cole–Hopf transformation. Thus, on finite intervals
Burgers’ equation with a homogenous Neumann boundary condition is truly nonlinear. Second,
the nonlinear term in Burgers’ equation with a homogenous Neumann boundary condition is
not conservative. This structure plays a key role in understanding the complex dynamics
generated by Burgers’ equation with a Neumann boundary condition and how this structure
impacts numerical approximations. The key point is that, regardless of the particular
numerical scheme, finite precision arithmetic will always lead to numerically generated
equilibrium states that do not correspond to equilibrium states of the Burgers’ equation.
In this paper we establish the existence and stability properties of these numerical
stationary solutions and employ a bifurcation analysis to provide a detailed mathematical
explanation of why numerical schemes fail to capture the correct asymptotic dynamics. We
extend the results in [E. Allen, J.A. Burns, D.S. Gilliam, J. Hill and V.I. Shubov,
Math. Comput. Modelling 35 (2002) 1165–1195] and prove
that the effect of finite precision arithmetic persists in generating a nonzero numerical
false solution to the stationary Burgers’ problem. Thus, we show that the results obtained
in [E. Allen, J.A. Burns, D.S. Gilliam, J. Hill and V.I. Shubov, Math. Comput.
Modelling 35 (2002) 1165–1195] are not dependent on a specific
time marching scheme, but are generic to all convergent numerical approximations of