11,757 research outputs found
Responses of a bacterial pathogen to phosphorus limitation of its aquatic invertebrate host
Host nutrition is thought to affect the establishment, persistence, and severity of pathogenic infections. Nutrient-deficient foods possibly benefit pathogens by constraining host immune function or benefit hosts by limiting parasite growth and reproduction. However, the effects of poor elemental food quality on a host's susceptibility to infection and disease have received little study. Here we show that the bacterial microparasite Pasteuria ramosa is affected by the elemental nutrition of its aquatic invertebrate host, Daphnia magna. We found that high food carbon : phosphorus (C: P) ratios significantly reduced infection rates of Pasteuria in Daphnia and led to lower within-host pathogen multiplication. In addition, greater virulent effects of bacterial infection on host reproduction were found in Daphnia-consuming P-deficient food. Poor Daphnia elemental nutrition thus reduced the growth and reproduction of its bacterial parasite, Pasteuria. The effects of poor host nutrition on the pathogen were further evidenced by Pasteuria's greater inhibition of reproduction in P-limited Daphnia. Our results provide strong evidence that elemental food quality can significantly influence the incidence and intensity of infectious disease in invertebrate hosts
Analysis of data from NASA B-57B gust gradient program
Statistical analysis of the turbulence measured in flight 6 of the NASA B-57B over Denver, Colorado, from July 7 to July 23, 1982 included the calculations of average turbulence parameters, integral length scales, probability density functions, single point autocorrelation coefficients, two point autocorrelation coefficients, normalized autospectra, normalized two point autospectra, and two point cross sectra for gust velocities. The single point autocorrelation coefficients were compared with the theoretical model developed by von Karman. Theoretical analyses were developed which address the effects spanwise gust distributions, using two point spatial turbulence correlations
Image synthesis for SAR system, calibration and processor design
The Point Scattering Method of simulating radar imagery rigorously models all aspects of the imaging radar phenomena. Its computational algorithms operate on a symbolic representation of the terrain test site to calculate such parameters as range, angle of incidence, resolution cell size, etc. Empirical backscatter data and elevation data are utilized to model the terrain. Additionally, the important geometrical/propagation effects such as shadow, foreshortening, layover, and local angle of incidence are rigorously treated. Applications of radar image simulation to a proposed calibrated SAR system are highlighted: soil moisture detection and vegetation discrimination
Non-verbal sound processing in the primary progressive aphasias
Little is known about the processing of non-verbal sounds in the primary progressive aphasias. Here, we investigated the processing of complex non-verbal sounds in detail, in a consecutive series of 20 patients with primary progressive aphasia [12 with progressive non-fluent aphasia; eight with semantic dementia]. We designed a novel experimental neuropsychological battery to probe complex sound processing at early perceptual, apperceptive and semantic levels, using within-modality response procedures that minimized other cognitive demands and matching tests in the visual modality. Patients with primary progressive aphasia had deficits of non-verbal sound analysis compared with healthy age-matched individuals. Deficits of auditory early perceptual analysis were more common in progressive non-fluent aphasia, deficits of apperceptive processing occurred in both progressive non-fluent aphasia and semantic dementia, and deficits of semantic processing also occurred in both syndromes, but were relatively modality specific in progressive non-fluent aphasia and part of a more severe generic semantic deficit in semantic dementia. Patients with progressive non-fluent aphasia were more likely to show severe auditory than visual deficits as compared to patients with semantic dementia. These findings argue for the existence of core disorders of complex non-verbal sound perception and recognition in primary progressive aphasia and specific disorders at perceptual and semantic levels of cortical auditory processing in progressive non-fluent aphasia and semantic dementia, respectively
Responses of a bacterial pathogen to phosphorus limitation of its aquatic invertebrate host
Host nutrition is thought to affect the establishment, persistence, and severity of pathogenic infections. Nutrient-deficient foods possibly benefit pathogens by constraining host immune function or benefit hosts by limiting parasite growth and reproduction. However, the effects of poor elemental food quality on a host’s susceptibility to infection and disease have received little study. Here we show that the bacterial microparasite Pasteuria ramosa is affected by the elemental nutrition of its aquatic invertebrate host, Daphnia magna. We found that high food carbon : phosphorus (C:P) ratios significantly reduced infection rates of Pasteuria in Daphnia and led to lower within-host pathogen multiplication. In addition, greater virulent effects of bacterial infection on host reproduction were found in Daphniaconsuming P-deficient food. Poor Daphnia elemental nutrition thus reduced the growth and reproduction of its bacterial parasite, Pasteuria. The effects of poor host nutrition on the pathogen were further evidenced by Pasteuria’s greater inhibition of reproduction in P-limited Daphnia. Our results provide strong evidence that elemental food quality can significantly influence the incidence and intensity of infectious disease in invertebrate hosts.We thank H. Foy, C. Hibbert, M. Kingsbury, S. McCarthy, and D. Woolnough for their assistance with the experiments. This work was supported by grants from the Natural Sciences and Engineering Research Council of Canada and Trent University
The long road of statistical learning research: past, present and future
Published 21 November 2016
http://rstb.royalsocietypublishing.org/content/372/1711/20160047http://rstb.royalsocietypublishing.org/content/372/1711/20160047This paper was supported by the Israel Science Foundation
(grant no. 217/14 awarded to R.F.), by the National Institute of
Child Health and Human Development (RO1 HD 067364 awarded
to Ken Pugh and R.F., PO1-HD 01994 awarded to Haskins Laboratories)
and by the European Research Council (project ERC-ADG-
692502 awarded to R.F.)
Observations of celestial X-ray sources above 20 keV with the high-energy scintillation spectrometer on board OSO 8
High-energy X-ray spectra of the Crab Nebula, Cyg- XR-1, and Cen A were determined from observations with the scintillation spectrometer on board the OSO-8 satellite, launched in June, 1975. Each of these sources was observed over two periods of 8 days or more, enabling a search for day-to-day and year to year variations in the spectral and temporal characteristics of the X-ray emission. No variation in the light curve of the Crab pulsar was found from observations which span a 15-day period in March 1976, with demonstrable phase stability. Transitions associated with the binary phase of Cyg XR-1 and a large change in the emission from Con A are reported
Analysis of geologic terrain models for determination of optimum SAR sensor configuration and optimum information extraction for exploration of global non-renewable resources. Pilot study: Arkansas Remote Sensing Laboratory, part 1, part 2, and part 3
Computer-generated radar simulations and mathematical geologic terrain models were used to establish the optimum radar sensor operating parameters for geologic research. An initial set of mathematical geologic terrain models was created for three basic landforms and families of simulated radar images were prepared from these models for numerous interacting sensor, platform, and terrain variables. The tradeoffs between the various sensor parameters and the quantity and quality of the extractable geologic data were investigated as well as the development of automated techniques of digital SAR image analysis. Initial work on a texture analysis of SEASAT SAR imagery is reported. Computer-generated radar simulations are shown for combinations of two geologic models and three SAR angles of incidence
Patients’ and nurses’ experiences of fundamental nursing care: a systematic review and qualitative synthesis
This is the final version. Available on open access from Wiley via the DOI in this recordAims and objectives
To systematically identify, appraise and synthesise patients’, residents’, and nurses’ experiences of
fundamental nursing care for nutrition, elimination, mobility, and hygiene.
Background
The evidence base for effective nursing behaviours to assist people with their fundamental care
needs is sparse, hampering the development of effective interventions. Synthesising data on
patients’ and nurses’ experiences of fundamentals of nursing care could contribute to the
development of such an intervention.
Methods
Systematic review and synthesis of qualitative data from qualitative studies on patients’ and nurses’
experiences of fundamental nursing care behaviours addressing peoples’ nutrition, elimination,
mobility, and hygiene needs. We appraised study quality and relevance and used a narrative
approach to data synthesis, fulfilling PRISMA criteria (Supplementary file 1).
Results
We identified 22,374 papers, 47 met our inclusion criteria. Most papers were of low quality. Sixteen
papers met our quality and relevance criteria and were included for synthesis. Papers were about
nutrition (2) elimination (2), mobility (5), hygiene (5) and multiple care areas (2). We found nurses
and patients report that fundamental nursing care practices involve strong leadership, collaborative
2
partnerships with patients and cohesive organisational practices aligned to nursing care objectives
and actions.
Conclusions.
To improve fundamental care and interventions suitable for testing may require attention to
leadership, patient-nurse relationships and organisational coherence plus the fundamentals of care
nursing interventions themselves.
Relevance to clinical practice.
More rigorous mixed methods research about fundamental nursing care is needed to inform nursing
practice and improve patient’s experience. Nursing interventions should include effective nurse
leadership and nurse patient collaboration and a focus on fundamental care by the host
organisation
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