14,945 research outputs found
Advanced flight deck/crew station simulator functional requirements
This report documents a study of flight deck/crew system research facility requirements for investigating issues involved with developing systems, and procedures for interfacing transport aircraft with air traffic control systems planned for 1985 to 2000. Crew system needs of NASA, the U.S. Air Force, and industry were investigated and reported. A matrix of these is included, as are recommended functional requirements and design criteria for simulation facilities in which to conduct this research. Methods of exploiting the commonality and similarity in facilities are identified, and plans for exploiting this in order to reduce implementation costs and allow efficient transfer of experiments from one facility to another are presented
High accuracy results for the energy levels of the molecular ions H2+, D2+ and HD+, up to J=2
We present a nonrelativistic calculation of the rotation-vibration levels of
the molecular ions H2+, D2+ and HD+, relying on the diagonalization of the
exact three-body Hamiltonian. The J=2 levels are obtained with a very high
accuracy of 10^{-14} a.u. (for most levels) representing an improvement by five
orders of magnitude over previous calculations. The accuracy is also improved
for the J=1 levels of H2+ and D2+ with respect to earlier works. Moreover, we
have computed the sensitivities of the energy levels with respect to the mass
ratios, allowing these levels to be used for metrological purposes.Comment: 11 page
Investigation in haemodynamic stability during intermittent haemodialysis in the critically ill
No abstract available
An investigation into the effects of commencing haemodialysis in the critically ill
<b>Introduction:</b>
We have aimed to describe haemodynamic changes when haemodialysis is instituted in the critically ill. 3
hypotheses are tested: 1)The initial session is associated with cardiovascular instability, 2)The initial session is
associated with more cardiovascular instability compared to subsequent sessions, and 3)Looking at unstable
sessions alone, there will be a greater proportion of potentially harmful changes in the initial sessions compared
to subsequent ones.
<b>Methods:</b>
Data was collected for 209 patients, identifying 1605 dialysis sessions. Analysis was performed on hourly
records, classifying sessions as stable/unstable by a cutoff of >+/-20% change in baseline physiology
(HR/MAP). Data from 3 hours prior, and 4 hours after dialysis was included, and average and minimum values
derived. 3 time comparisons were made (pre-HD:during, during HD:post, pre-HD:post). Initial sessions were
analysed separately from subsequent sessions to derive 2 groups. If a session was identified as being unstable,
then the nature of instability was examined by recording whether changes crossed defined physiological ranges.
The changes seen in unstable sessions could be described as to their effects: being harmful/potentially harmful,
or beneficial/potentially beneficial.
<b>Results:</b>
Discarding incomplete data, 181 initial and 1382 subsequent sessions were analysed. A session was deemed to
be stable if there was no significant change (>+/-20%) in the time-averaged or minimum MAP/HR across time
comparisons. By this definition 85/181 initial sessions were unstable (47%, 95% CI SEM 39.8-54.2). Therefore
Hypothesis 1 is accepted. This compares to 44% of subsequent sessions (95% CI 41.1-46.3). Comparing these
proportions and their respective CI gives a 95% CI for the standard error of the difference of -4% to 10%.
Therefore Hypothesis 2 is rejected. In initial sessions there were 92/1020 harmful changes. This gives a
proportion of 9.0% (95% CI SEM 7.4-10.9). In the subsequent sessions there were 712/7248 harmful changes.
This gives a proportion of 9.8% (95% CI SEM 9.1-10.5). Comparing the two unpaired proportions gives a
difference of -0.08% with a 95% CI of the SE of the difference of -2.5 to +1.2. Hypothesis 3 is rejected. Fisher’s
exact test gives a result of p=0.68, reinforcing the lack of significant variance.
<b>Conclusions:</b>
Our results reject the claims that using haemodialysis is an inherently unstable choice of therapy. Although
proportionally more of the initial sessions are classed as unstable, the majority of MAP and HR changes are
beneficial in nature
Recommended from our members
Barriers to reporting non-motor symptoms to health-care providers in people with Parkinson's
Background: Non-motor symptoms (NMS) are common in Parkinson's disease (PD) and cause significant distress. A high rate of non-declaration of NMS by patients to healthcare providers (HCP) means that many NMS remain untreated. Current understanding of the factors preventing disclosure of NMS to HCPs is limited. The present study aimed to i) further assess the prevalence of NMS and associated distress, ii) establish current rates of NMS reporting across a range of sources, and iii) explore overall and any symptom specific barriers to help-seeking for NMS.
Methods: 358 PD patients completed a cross-sectional survey of NMS severity, reporting and barriers to help-seeking. A series of Generalised Estimating Equations were used to determine whether barriers were symptom specific.
Results: A mean of 10.5 NMS were reported by each patient. Rates of non-reporting of NMS ranged from 15 to 72% of those experiencing distressing symptoms. The most commonly reported barriers to help-seeking were acceptance of symptoms; lack of awareness that a symptom was associated with PD, and belief that no effective treatments were available. Symptom specific barriers were found for sexual dysfunction (embarrassment), unexplained pain and urinary problems (belief about lack of treatment availability).
Conclusion: A diverse range of barriers prevent PD patients reporting NMS to HCPs and these barriers differ between NMS. The study provides the foundations for developing interventions to increase reporting by targeting individual NMS. Increasing rates of help-seeking for NMS by patients to their Parkinson's healthcare providers will increase appropriate clinical care which may improve quality of life and well-being
COMPARING MANAGEMENT SYSTEMS FOR BEEF CATTLE BACKGROUNDING: A MULTIDISCIPLINARY APPROACH
Livestock Production/Industries,
Resistance and Propulsion Test Results on Two Cb=0.60 Merchant Hull Geosims
http://deepblue.lib.umich.edu/bitstream/2027.42/96607/1/39015087358712.pd
Warm inflation model building
We review the main aspects of the warm inflation scenario, focusing on the
inflationary dynamics and the predictions related to the primordial spectrum of
perturbations, to be compared with the recent cosmological observations. We
study in detail three different classes of inflationary models, chaotic, hybrid
models and hilltop models, and discuss their embedding into supersymmetric
models and the consequences for model building of the warm inflationary
dynamics based on first principles calculations. Due to the extra friction term
introduced in the inflaton background evolution generated by the dissipative
dynamics, inflation can take place generically for smaller values of the field,
and larger values of couplings and masses. When the dissipative dynamics
dominates over the expansion, in the so-called strong dissipative regime,
inflation proceeds with sub-planckian inflaton values. Models can be naturally
embedded into a supergravity framework, with sugra corrections suppressed by
the Planck mass now under control, for a larger class of K\"ahler potentials.
In particular, this provides a simpler solution to the "eta" problem in
supersymmetric hybrid inflation, without restricting the K\"ahler potentials
compatible with inflation. For chaotic models dissipation leads to a smaller
prediction for the tensor-to-scalar ratio and a less tilted spectrum when
compared to the cold inflation scenario. We find in particular that a small
component of dissipation renders the quartic model now consistent with the
current CMB data.Comment: 22 pages, 5 figure
Local Approximations for Effective Scalar Field Equations of Motion
Fluctuation and dissipation dynamics is examined at all temperature ranges
for the general case of a background time evolving scalar field coupled to
heavy intermediate quantum fields which in turn are coupled to light quantum
fields. The evolution of the background field induces particle production from
the light fields through the action of the intermediate catalyzing heavy
fields. Such field configurations are generically present in most particle
physics models, including Grand Unified and Supersymmetry theories, with
application of this mechanism possible in inflation, heavy ion collision and
phase transition dynamics. The effective evolution equation for the background
field is obtained and a fluctuation-dissipation theorem is derived for this
system. The effective evolution in general is nonlocal in time. Appropriate
conditions are found for when these time nonlocal effects can be approximated
by local terms. Here careful distinction is made between a local expansion and
the special case of a derivative expansion to all orders, which requires
analytic behavior of the evolution equation in Fourier space.Comment: 14 pages, 2 figures. Replaced with published version. Some extra
typos correcte
MOXE: An X-ray all-sky monitor for Soviet Spectrum-X-Gamma Mission
A Monitoring Monitoring X-Ray Equipment (MOXE) is being developed for the Soviet Spectrum-X-Gamma Mission. MOXE is an X-ray all-sky monitor based on array of pinhole cameras, to be provided via a collaboration between Goddard Space Flight Center and Los Alamos National Laboratory. The objectives are to alert other observers on Spectrum-X-Gamma and other platforms of interesting transient activity, and to synoptically monitor the X-ray sky and study long-term changes in X-ray binaries. MOXE will be sensitive to sources as faint as 2 milliCrab (5 sigma) in 1 day, and cover the 2 to 20 KeV band
- …