1,852 research outputs found
Numerical study of the small dispersion limit of the Korteweg-de Vries equation and asymptotic solutions
We study numerically the small dispersion limit for the Korteweg-de Vries
(KdV) equation for and give a
quantitative comparison of the numerical solution with various asymptotic
formulae for small in the whole -plane. The matching of the
asymptotic solutions is studied numerically
Effect of germanium substrate loss and nitrogen on dopant diffusion in germanium
Recent experimental studies demonstrate a significant germanium (Ge) substrate loss and consequently dopant loss even during low temperature annealing. Additionally, for phosphorous (P) implanted Ge the capping layer material affects P diffusion. Silicon nitride (Si3N4) capping is more efficient compared to silicon dioxide (SiO2) capping, but an accumulation of P is observed at the Ge/Si3N4 interface. In the present study, the recent experimental evidence is evaluated and with the use of electronic structure simulations the formation of relevant defects is investigated. It is predicted that the formation of clusters containing nitrogen (N) and vacancies (V) can be related to the observed accumulation of P atoms near the Ge/Si3N4 interface
Creating an Environment for a Fully Realized Right to Food: Progress, Challenges and Emerging Alternative Policy Models
Noninvasive Embedding of Single Co Atoms in Ge(111)2x1 Surfaces
We report on a combined scanning tunneling microscopy (STM) and density
functional theory (DFT) based investigation of Co atoms on Ge(111)2x1 surfaces.
When deposited on cold surfaces, individual Co atoms have a limited diffusivity
on the atomically flat areas and apparently reside on top of the upper
pi-bonded chain rows exclusively. Voltage-dependent STM imaging reveals a
highly anisotropic electronic perturbation of the Ge surface surrounding these
Co atoms and pronounced one-dimensional confinement along the pi-bonded chains.
DFT calculations reveal that the individual Co atoms are in fact embedded in
the Ge surface, where they occupy a quasi-stationary position within the big
7-member Ge ring in between the 3rd and 4th atomic Ge layer. The energy needed
for the Co atoms to overcome the potential barrier for penetration in the Ge
surface is provided by the kinetic energy resulting from the deposition
process. DFT calculations further demonstrate that the embedded Co atoms form
four covalent Co-Ge bonds, resulting in a Co4+ valence state and a 3d5
electronic configuration. Calculated STM images are in perfect agreement with
the experimental atomic resolution STM images for the broad range of applied
tunneling voltages.Comment: 19 pages, 15 figures, 3 table
Proprioceptive changes impair balance control in individuals with chronic obstructive pulmonary disease
Copyright @ 2013 Janssens et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction: Balance deficits are identified as important risk factors for falling in individuals with chronic obstructive pulmonary disease (COPD). However, the specific use of proprioception, which is of primary importance during balance control, has not been studied in individuals with COPD. The objective was to determine the specific proprioceptive control strategy during postural balance in individuals with COPD and healthy controls, and to assess whether this was related to inspiratory muscle weakness. Methods: Center of pressure displacement was determined in 20 individuals with COPD and 20 age/gender-matched controls during upright stance on an unstable support surface without vision. Ankle and back muscle vibration were applied to evaluate the relative contribution of different proprioceptive signals used in postural control. Results: Individuals with COPD showed an increased anterior-posterior body sway during upright stance (p=0.037). Compared to controls, individuals with COPD showed an increased posterior body sway during ankle muscle vibration (p=0.047), decreased anterior body sway during back muscle vibration (p=0.025), and increased posterior body sway during simultaneous ankle-muscle vibration (p=0.002). Individuals with COPD with the weakest inspiratory muscles showed the greatest reliance on ankle muscle input when compared to the stronger individuals with COPD (p=0.037). Conclusions: Individuals with COPD, especially those with inspiratory muscle weakness, increased their reliance on ankle muscle proprioceptive signals and decreased their reliance on back muscle proprioceptive signals during balance control, resulting in a decreased postural stability compared to healthy controls. These proprioceptive changes may be due to an impaired postural contribution of the inspiratory muscles to trunk stability. Further research is required to determine whether interventions such as proprioceptive training and inspiratory muscle training improve postural balance and reduce the fall risk in individuals with COPD.This work was supported by the Research Foundation β Flanders (FWO) grants 1.5.104.03, G.0674.09, G.0598.09N and G.0871.13N
Where are Hf and REE hosted in CV β CK chondrites? Clues to understanding the Ξ΅Hf heterogeneities in CHUR.
第3εζ₯΅εη§ε¦γ·γ³γγΈγ¦γ /第35εεζ₯΅ιη³γ·γ³γγΈγ¦γ 11ζ30ζ₯οΌιοΌ ε½η«ε½θͺη η©Άζ 2ιθ¬
PHP251 Assessment of Consumer Likelihood to Adopt an Electronic Health Record (EHR) Mobile Application and the Impact of Perceived Risk of Privacy Leaks
Optimal urine culture diagnostic stewardship practice- Results from an expert modified-Delphi procedure
BACKGROUND: Urine cultures are nonspecific and often lead to misdiagnosis of urinary tract infection and unnecessary antibiotics. Diagnostic stewardship is a set of procedures that modifies test ordering, processing, and reporting in order to optimize diagnosis and downstream treatment. In this study, we aimed to develop expert guidance on best practices for urine culture diagnostic stewardship.
METHODS: A RAND-modified Delphi approach with a multidisciplinary expert panel was used to ascertain diagnostic stewardship best practices. Clinical questions to guide recommendations were grouped into three thematic areas (ordering, processing, reporting) in practice settings of emergency department, inpatient, ambulatory, and long-term care. Fifteen experts ranked recommendations on a 9-point Likert scale. Recommendations on which the panel did not reach agreement were discussed during a virtual meeting, then a second round of ranking by email was completed. After secondary review of results and panel discussion, a series of guidance statements was developed.
RESULTS: One hundred and sixty-five questions were reviewed. The panel reaching agreement on 104, leading to 18 overarching guidance statements. The following strategies were recommended to optimize ordering urine cultures: requiring documentation of symptoms, sending alerts to discourage ordering in the absence of symptoms, and cancelling repeat cultures. For urine culture processing, conditional urine cultures and urine white blood cell count as criteria were supported. For urine culture reporting, appropriate practices included nudges to discourage treatment under specific conditions and selective reporting of antibiotics to guide therapy decisions.
CONCLUSIONS: These 18 guidance statements can optimize use of urine cultures for better patient outcomes
PHP243 Consumer Interest in Adopting an Electronic Health Record (EHR) Mobile Application Based on the Risk that Identifiable Information is Leaked
Impaired Postural Control Reduces Sit-to-Stand-to-Sit Performance in Individuals with Chronic Obstructive Pulmonary Disease
Abstract
Background: Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic
obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has
been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to
the decreased STSTS performance in individuals with COPD.
Methods: Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched
controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each
sit, sit-to-stand, stand and stand-to-sit phase was recorded.
Results: Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (1966 vs. 1364 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups.
Conclusions: Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD
- β¦