13,060 research outputs found
Investigation of strength of isolated vertebrae, phase IV Final technical report, 29 Oct. 1965 - 28 Oct. 1966
Dynamic strength measurements of human vertebrae under axial compressio
Investigation of strength of isolated vertebrae Quarterly report, 30 Jan. - 29 May 1966
Strength of human vertebrae under various static and dynamic load
Disease associated with equine coronavirus infection and high case fatality rate.
BackgroundEquine coronavirus (ECoV) is associated with clinical disease in adult horses. Outbreaks are associated with a low case fatality rate and a small number of animals with signs of encephalopathic disease are described.ObjectivesThe aim of this study is to describe the epidemiological and clinical features of two outbreaks of ECoV infection that were associated with an high case fatality rate.Animals14 miniature horses and 1 miniature donkey testing fecal positive for ECoV from two related disease outbreaks.MethodsRetrospective study describing the epidemiological findings, clinicopathological findings, and fecal viral load from affected horses.ResultsIn EcoV positive horses, 27% (4/15) of the animals died or were euthanized. Severe hyperammonemia (677 μmol/L, reference range ≤ 60 μmol/L) was identified in one animal with signs of encephalopathic disease that subsequently died. Fecal viral load (ECoV genome equivalents per gram of feces) was significantly higher in the nonsurvivors compared to animals that survived (P = .02).Conclusions and clinical importanceEquine coronavirus had a higher case fatality rate in this group of miniature horses than previously reported in other outbreaks of varying breeds. Hyperammonemia could contribute to signs of encephalopathic disease, and the fecal viral load might be of prognostic value in affected horses
Person-centred oral hydration care for older people with dementia admitted to acute hospital wards: Empirical research qualitative.
To conduct an in-depth exploration of oral hydration care provided to people living with dementia in acute hospital wards, using a person-centred care framework. Oral hydration care is an important, yet rarely explored aspect of fundamental care for people with dementia admitted to acute hospitals. Using person-centred care as a conceptual framework we investigated how oral hydration care is delivered for people living with dementia in acute hospital wards. A qualitative, multiple-case study. The cases were three acute wards in one hospital. Direct observation of care for 13 people with dementia (132 h), semistructured interviews with ward staff (n = 28), ward leaders (n = 4), organisational leaders (n = 5), people with dementia (n = 6), their relatives (n = 5), documentary analysis of clinical inpatient records (n = 26) and relevant hospital policies. Data were analysed using framework analysis. Four themes were identified: (1) The acute hospital: oral hydration is obscured and not prioritised (2) Overshadowing of oral hydration at ward level (3) Siloed nature of hydration roles (4) Strategies for, and barriers to, delivering person-centred oral hydration care. This study combines the concept of person-centred care and oral hydration care for people living with dementia admitted to acute hospital wards, demonstrating that person-centred hydration care was complex and not prioritised. Nurses should consider means of improving prioritisation and cohesive delivery of person-centred hydration care in acute hospital wards. [Abstract copyright: © 2023 The Authors. Journal of Clinical Nursing published by John Wiley & Sons Ltd.
Statistical Mechanics of Vibration-Induced Compaction of Powders
We propose a theory which describes the density relaxation of loosely packed,
cohesionless granular material under mechanical tapping. Using the compactivity
concept we develope a formalism of statistical mechanics which allows us to
calculate the density of a powder as a function of time and compactivity. A
simple fluctuation-dissipation relation which relates compactivity to the
amplitude and frequency of a tapping is proposed. Experimental data of
E.R.Nowak et al. [{\it Powder Technology} 94, 79 (1997) ] show how density of
initially deposited in a fluffy state powder evolves under carefully controlled
tapping towards a random close packing (RCP) density. Ramping the vibration
amplitude repeatedly up and back down again reveals the existence of reversible
and irreversible branches in the response. In the framework of our approach the
reversible branch (along which the RCP density is obtained) corresponds to the
steady state solution of the Fokker-Planck equation whereas the irreversible
one is represented by a superposition of "excited states" eigenfunctions. These
two regimes of response are analyzed theoretically and a qualitative
explanation of the hysteresis curve is offered.Comment: 11 pages, 2 figures, Latex. Revised tex
The distribution of extremal points of Gaussian scalar fields
We consider the signed density of the extremal points of (two-dimensional)
scalar fields with a Gaussian distribution. We assign a positive unit charge to
the maxima and minima of the function and a negative one to its saddles. At
first, we compute the average density for a field in half-space with Dirichlet
boundary conditions. Then we calculate the charge-charge correlation function
(without boundary). We apply the general results to random waves and random
surfaces. Furthermore, we find a generating functional for the two-point
function. Its Legendre transform is the integral over the scalar curvature of a
4-dimensional Riemannian manifold.Comment: 22 pages, 8 figures, corrected published versio
Testing non-Gaussianity in CMB Maps by Morphological Statistic
The assumption of Gaussianity of the primordial perturbations plays an
important role in modern cosmology. The most direct test of this hypothesis
consists in testing Gaussianity of the CMB maps. Counting the pixels with the
temperatures in given ranges and thus estimating the one point probability
function of the field is the simplest of all the tests. Other usually more
complex tests of Gaussianity generally use a great deal of the information
already contained in the probability function. However, the most interesting
outcome of such a test would be the signal of non-Gaussianity independent of
the probability function. It is shown that the independent information has
purely morphological character i.e. it depends on the geometry and topology of
the level contours only. As an example we discuss in detail the quadratic model
( is a Gaussian field with and ,
is a parameter) which may arise in slow-roll or two-field inflation
models. We show that in the limit of small amplitude the full
information about the non-Gaussianity is contained in the probability function.
If other tests are performed on this model they simply recycle the same
information. A simple procedure allowing to assess the sensitivity of any
statistics to the morphological information is suggested. We provide an
analytic estimate of the statistical limit for detecting the quadratic
non-Gaussianity \a_c as a function of the map size in the ideal situation
when the scale of the field is resolved. This estimate is in a good agreement
with the results of the Monte Carlo simulations of and maps.
The effect of resolution on the detection quadratic non-Gaussianity is also
briefly discussed.Comment: 26 pages, 9 figure
Waterfowl and Habitat Changes After 40 Years on the Waubay Study Area
We collected data on upland and aquatic habitats, waterfowl populations, and landowner demographics in the Waubay study area to document habitat, land use, demographic, and ownership changes and to determine temporal and spatial changes in the physical and vegetative characteristics of wetlands since 1950-53. We also compared current waterfowl abundances and reproductive indices with those of the earlier study. Results from our study will provide waterfowl managers in the prairie pothole region a comprehensive evaluation of landscape changes and their relationships to waterfowl abundances over a 40- year time period
Slow plasmon modes in polymeric salt solutions
The dynamics of polymeric salt solutions are presented. The salt consists of
chains and , which are chemically different and interact with a
Flory-interaction parameter , the chain ends carry a positive
charge whereas the chain ends are modified by negative charges. The
static structure factor shows a peak corresponding to a micro phase separation.
At low momentum transfer, the interdiffusion mode is driven by electrostatics
and is of the plasmon-type, but with an unusually low frequency, easily
accessible by experiments. This is due to the polymer connectivity that
introduces high friction and amplifies the charge scattering thus allowing for
low charge densities. The interdiffusion mode shows a minimum (critical slowing
down) at finite when the interaction parameter increases we find then a low
frequency quasi-plateau.Comment: accepted in Europhys. Let
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