2,871 research outputs found
Does the shoe fit? Applying lessons learned in aviation to healthcare
pre-printAviation's successful use of Decision Support Systems (DSS) has not been replicated in the healthcare subset of DSS referenced as Clinical Decision Support (CDS). Here the domains of healthcare and aviation are compared and contrasted providing an overview of the adaptation of lessons learned in aviation to healthcare. We propose there are differences in characteristics inherent to the contexts of aviation and healthcare that affect the data necessary for efficient, effective CDS systems. Specifically, ten context characteristics are discussed that jointly and separately affect the availability, quantity, quality and temporal relevance of the data. By providing remedies for overcoming deficiencies and supporting accurate representation of the data perhaps then CDS systems will meet their potential for improved adoption, user satisfaction and patient outcomes
Derivation of a dynamic model of the kinetics of nitrogen uptake throughout the growth of lettuce : calibration and validation
A kinetic model of nitrogen (N) uptake throughout growth was developed for lettuce
cultivated in nutrient solution under varying natural light conditions. The model couples
nitrogen uptake with dry matter accumulation using a two-compartment mechanistic
approach, incorporating structural and non-structural pools. Maximum nitrogen uptake
rates are assumed to decline with shoot dry weight, to allow for the effects of plant
age. The model was parameterized using data from the literature, and calibrated for
differences in light intensity using an optimization algorithm utilizing data from three
experiments in different growing seasons. The calibrated model was validated against
the data from two independent experiments conducted under different light conditions.
Results showed that the model made good predictions of nitrogen uptake by plants from
seedlings to maturity under fluctuating light levels in a glasshouse. Plants grown at a
higher light intensity showed larger maximum nitrogen uptake rates, but the effect of
light intensity declined towards plant maturity
Do We Know What We Need? Preference for Feedback About Accurate Performances Does Not Benefit Sensorimotor Learning
Previous research on skill acquisition has shown that learners seem to prefer receiving knowledge of results (KR) about those trials in which they have performed more accurately. In the present study, we assessed whether this preference leads to an advantage in terms of skill acquisition, transfer, and retention of their capacity to extrapolate the motion of decelerating objects during periods of visual occlusion. Instead of questionnaires, we adopted a more direct approach to investigate learners' preferences for KR. Participants performed 90 trials of a motion extrapolation task (acquisition phase) in which, every three trials, they could decide between receiving KR about their best or worst performance. Retention and transfer tests were carried out 24 hr after the acquisition phase, without KR, to examine the effects of the self-selected KR on sensorimotor learning. Consistent with the current literature, a preference for receiving KR about the most accurate performance was observed. However, participants' preferences were not consistent throughout the experiment as less than 10% (N = 40) selected the same type of KR in all their choices. Importantly, although preferred by most participants, KR about accurate performances had detrimental effects on skill acquisition, suggesting that learners may not always choose the KR that will maximize their learning experiences and skill retention
Identification of transcription-factor genes expressed in the Arabidopsis female gametophyte
Dongfang Wang, Changqing Zhang, David J. Hearn, Il-HO Kang, megan I. Skaggs, Karen S. Schumaker, and Ramin Yadegari are with the School of Plant Sciences, University of Arizona, Tucson, Arizona 85721-0036, USA -- Il-Ho Kang, Jayson A. Punwani, and Gary N. Drews are with the Department of Biology, University of Utah, Salt Lake City, Utah 84112-0840, USA -- Changqing Zhang is with The Section of Molecular, Cell and Developmental Biology, University of Texas at Austin, Austin, Texas 78712-0159, USA -- David J. Hearn is with the Department of Biological Sciences, Towson University, Towson, Maryland 21252-0001, USA -- Il-Ho Kang is with the Department of Horticulture, Iowa State University, Ames, Iowa 50011-1100, USA --Jayson A. Punwani is with the Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3280, USABackground
In flowering plants, the female gametophyte is typically a seven-celled structure with four cell types: the egg cell, the central cell, the synergid cells, and the antipodal cells. These cells perform essential functions required for double fertilization and early seed development. Differentiation of these distinct cell types likely involves coordinated changes in gene expression regulated by transcription factors. Therefore, understanding female gametophyte cell differentiation and function will require dissection of the gene regulatory networks operating in each of the cell types. These efforts have been hampered because few transcription factor genes expressed in the female gametophyte have been identified. To identify such genes, we undertook a large-scale differential expression screen followed by promoter-fusion analysis to detect transcription-factor genes transcribed in the Arabidopsis female gametophyte.
Results
Using quantitative reverse-transcriptase PCR, we analyzed 1,482 Arabidopsis transcription-factor genes and identified 26 genes exhibiting reduced mRNA levels in determinate infertile 1 mutant ovaries, which lack female gametophytes, relative to ovaries containing female gametophytes. Spatial patterns of gene transcription within the mature female gametophyte were identified for 17 transcription-factor genes using promoter-fusion analysis. Of these, ten genes were predominantly expressed in a single cell type of the female gametophyte including the egg cell, central cell and the antipodal cells whereas the remaining seven genes were expressed in two or more cell types. After fertilization, 12 genes were transcriptionally active in the developing embryo and/or endosperm.
Conclusions
We have shown that our quantitative reverse-transcriptase PCR differential-expression screen is sufficiently sensitive to detect transcription-factor genes transcribed in the female gametophyte. Most of the genes identified in this study have not been reported previously as being expressed in the female gametophyte. Therefore, they might represent novel regulators and provide entry points for reverse genetic and molecular approaches to uncover the gene regulatory networks underlying female gametophyte development.Cellular and Molecular [email protected]
Harvester-Forwarder and Harvester-Yarder Systems for Fuel Reduction Treatments
Two harvesting systems were compared for reducing fuel loadings in overstocked conifer stands in eastern Oregon; forest managers also set a high priority on minimizing soil disturbance. Both employed cut-to-length (CTL) harvesters; one used a forwarder and the other a small skyline yarder. Both systems produced very similar and acceptable results in terms of fuels reduction and soil disturbance, but at different stump-to-mill costs: 80/green ton for the yarder system
CO21 234. Implantación trans apical de válvula aórtica: excelentes resultados en pacientes de alto riesgo
ObjetivosLa implantación transapical de válvulas aórticas es un método nuevo aplicable a pacientes de alto riesgo y estenosis grave de válvula aórtica. Un informe de nuestra experiencia inicial.MétodosDesde abril de 2008 fueron tratados 208 pacientes (edad 79±8 anos, media 36-99 años), con el método híbrido de implantación transapical de válvula aórtica. La media logística EuroSCORE (STS) fue de 40±20% (6-97%) y la media del STS score 21±16% (3-97%). Catorce pacientes ingresaron en shock cardiogénico. Operaciones combinadas fueron efectuadas en 30 pacientes. Intervención de coronarias con stent en 25 pacientes, corrección de ASD en un paciente, dilatación de estenosis pulmonar en un paciente. Aneurismectomía en dos pacientes.Implantación de stent en la arteria renal en un paciente.ResultadosEl éxito técnico de las operaciones fue del 99,5%, la mortalidad hospitalaria fue de 5,7% para todo el grupo, 21% para el grupo en shock cardiogénico. No hubo complicaciones neurológicas en ningún paciente. En el 6% de los pacientes operados hubo la necesidad de implantación de marcapasos. El análisis de regresión univariante demuestra que el shock cardiogénico, elevado B-type natriuretic peptide (BNP)-level, son claros indicadores para la mortalidad postoperatoria temprana (30 días después de la operación). Shock cardiogénico, New York Heart Association (NYHA) IV, altos scores de riesgo, insuficiencia renal grave, son factores independientes para la predicción de la mortalidad acumulativa.ConclusionesLa técnica de recambio transapical de válvulas aórticas reduce significativamente el riesgo operatorio en pacientes de alto riesgo en comparación con el método convencional de recambio valvular aórtico
The Evaluation of a Graphical Pulmonary Display in Anesthesiology
We have developed graphic technology to display data from the respiratory monitors used during anesthesia. The display uses color, texture, shape and emergent features to highlight abnormal pulmonary physiology. Nineteen anesthesiologists participated in a simulator based evaluation (METI, Sarasota, FL.). Half the subjects used the metaphor display and half did not. Each subject was trained for 10 minutes on the pulmonary display. The time difference during the obstructed endotracheal tube did prove significant (p=0.02) in favor of the pulmonary display condition. During the intrinsic PEEP scenario, the subjects treated the patient earlier (positive trend p=0.l) with the pulmonary display compared to the control condition. The group that used the pulmonary display treated a restricted upper airway more quickly (2.3 min vs. 3.9 min). Subjects liked the simplicity of the design. In future studies, we hope to further reduce the time for the detection and treatment of all scenarios by improving the design\u27s intuitiveness, integration, and emergent features
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