553 research outputs found
Genome-wide selection by mixed model ridge regression and extensions based on geostatistical models
Contrast-induced nephropathy.
Radiological procedures utilizing intravascular iodinated contrast media are being widely applied for both diagnostic and therapeutic purposes and represent one of the main causes of contrast-induced nephropathy (CIN) and hospital-acquired renal failure. Due to the lack of any effective treatment, prevention of this iatrogenic disease, which is associated with significant in-hospital and long-term morbidity and mortality and increased costs, is the key strategy. However, prevention of CIN continues to elude clinicians and is a major concern during percutaneous coronary interventions (PCI), as patients undergoing these procedures often have multiple comorbidities. The purpose of this article is to examine the pathophysiology, risk factors, and clinical course of CIN, as well as the most recent studies dealing with its prevention and potential therapeutic interventions, especially during PCI
Rigid fibrescope Bonfils: use in simulated difficult airway by novices
<p>Abstract</p> <p>Background</p> <p>The Bonfils intubation fibrescope is a promising alternative device for securing the airway. We examined the success rate of intubation and the ease of use in standardized simulated difficult airway scenarios by physicians. We compared the Bonfils to a classical laryngoscope with Macintosh blade.</p> <p>Methods</p> <p>30 physicians untrained in the use of rigid fibrescopes but experienced in airway management performed endotracheal intubation in an airway manikin (SimMan, Laerdal, Kent, UK) with three different airway conditions. We evaluated the success rate using the Bonfils (Karl Storz, Tuttlingen, Germany) or the Macintosh laryngoscope, the time needed for securing the airway, and subjective rating of both techniques.</p> <p>Results</p> <p>In normal airway all intubations were successful using laryngoscope (100%) vs. 82% using the Bonfils (p < 0.05). In the scenario "tongue oedema" success rate using the Macintosh laryngoscope was 67% and 83% using the Bonfils. In the scenario "decreased cervical range of motion with jaw trismus", success rate using the Macintosh laryngoscope was 84% vs. 76%. In difficult airway scenarios time until airway was secured did not differ between the two devices. Use of Bonfils was rated "easier" in both difficult airway scenarios.</p> <p>Conclusion</p> <p>The Bonfils can be successfully used by physicians unfamiliar with this technique in an airway manikin. The airway could be secured with at least the same success rate as using a Macintosh laryngoscope in difficult airway scenarios. Use of the Bonfils did not delay intubation in the presence of a difficult airway. These results indicate that intensive special training is advised to use the Bonfils effectively in airway management.</p
Comparison of the McGrath® Series 5 and GlideScope® Ranger with the Macintosh laryngoscope by paramedics
<p>Abstract</p> <p>Background</p> <p>Out-of-hospital endotracheal intubation performed by paramedics using the Macintosh blade for direct laryngoscopy is associated with a high incidence of complications. The novel technique of video laryngoscopy has been shown to improve glottic view and intubation success in the operating room. The aim of this study was to compare glottic view, time of intubation and success rate of the McGrath<sup>® </sup>Series 5 and GlideScope<sup>® </sup>Ranger video laryngoscopes with the Macintosh laryngoscope by paramedics.</p> <p>Methods</p> <p>Thirty paramedics performed six intubations in a randomised order with all three laryngoscopes in an airway simulator with a normal airway. Subsequently, every participant performed one intubation attempt with each device in the same manikin with simulated cervical spine rigidity using a cervical collar. Glottic view, time until visualisation of the glottis and time until first ventilation were evaluated.</p> <p>Results</p> <p>Time until first ventilation was equivalent after three intubations in the first scenario. In the scenario with decreased cervical motion, the time until first ventilation was longer using the McGrath<sup>® </sup>compared to the GlideScope<sup>® </sup>and AMacintosh (p < 0.01). The success rate for endotracheal intubation was similar for all three devices. Glottic view was only improved using the McGrath<sup>® </sup>device (p < 0.001) compared to using the Macintosh blade.</p> <p>Conclusions</p> <p>The learning curve for video laryngoscopy in paramedics was steep in this study. However, these data do not support prehospital use of the McGrath<sup>® </sup>and GlideScope<sup>® </sup>devices by paramedics.</p
The effects of cropping sequence, fertilization, and straw management on the yield stability of winter wheat (1986–2017) in the Broadbalk Wheat Experiment, Rothamsted, UK.
The development of resilient cropping systems with high yield stability is becoming increasingly important due to future climatic and agronomic challenges. Consequently, it is essential to be able to evaluate the effects of differing agronomic management practices, such as cropping sequences, and nutrient supply on the stability of crop yields. Long-term experiments are a valuable resource for investigating these effects, providing a sufficient number of years for accurate stability parameter estimation. The objective of the current study was to evaluate the effects of cropping sequence (#1: continuous vs rotational), fertilization (#2: mineral vs organic) and straw management in the case of continuous wheat (#3: removal vs incorporation) on the yield stability of winter wheat; yield risk (the probability of yield falling below a threshold yield level) and inter-annual yield variability were used as stability indicators of the effects. Long-term yield data from the Broadbalk Wheat Experiment (Rothamsted, United Kingdom) were analysed using a mixed model. Overall, the results showed that rotational cropping combined with supply of sufficient nutrients (N, P, and K) from mineral fertilizers, especially mineral N supply, ensured stable wheat yields whilst reducing the yield risk
Modellbasierte Analyse des Stoffumsatzes von Mageren Flachland-Mähwiesen in Baden-Württemberg im Critical-Loads-Konzept
Critical Loads für eutrophierenden Stickstoff werden anhand der Simple-Mass-Balance (SMB) Methode berechnet und dienen etwa in FFH-Verträglichkeitsprüfungen dem Schutz empfindlicher Ökosysteme (Anhang I FFH-Richtlinie). Die auf Basis der SMB ermittelten standortspezifischen Spannen für Critical Loads sind auf Grund von Unsicherheiten sowohl in den Eingangsgrößen als auch in den empirisch regelbasierten Methoden zur Berechnung der einzelnen Summanden in der SMB wenig vertrauenswürdig. Im Rahmen des von der Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg (LUBW) koordinierten Forschungsprojektes „Analyse und Bewertung des Stickstoffhaushalts Baden-Württemberg (AG Critical Loads)“ soll deshalb die Schaffung einer Datenbasis für eine Weiterentwicklung der bisherigen Ansätze für den in Baden-Württemberg weit verbreiteten FFH-Lebensraumtyp 6510 „Magere Flachland-Mähwiesen“ erfolgen. Einen möglichen Weg hin zu belastbaren Abschätzverfahren für die Summanden der SMB-Formel stellen dynamische Simulationen der am N-Umsatz beteiligten Stoffflüsse mit Hilfe prozessbasierter Modelle dar. Ziel der vorgestellten Studie ist es, mit Hilfe des Modellpakets Expert-N standortspezifisch für ausgewählte Flachland-Mähwiesen die mehrjährigen Mittelwerte der Mineralisierung, Denitrifikation, Immobilisierung und Nitratauswaschung zu berechnen. Als experimentelle Datengrundlage für die Modellierung werden Feldmessungen zur Abschätzung des N-Umsatzes in Abhängigkeit von Standortbedingungen und Erhaltungszustand der Vegetation durchgeführt. Dazu wird auf 4 extensiv genutzten Grünlandflächen in FFH-Gebieten über 2 Jahre ein intensives Monitoring der Stickstoffflüsse im Boden sowie begleitende Messungen zur Bodenfeuchte, -temperatur und N-Deposition durchgeführt. Der Fokus liegt auf der in situ Quantifizierung der Bruttoraten des N-Umsatzes (Mineralisierung, Nitrifizierung) als wichtige Parameter für die Modellierung des N-Kreislaufs. Die aus der prozessbasierten Modellierung gewonnenen Mittelwerte werden mit den nach den derzeitigen SMB-Ansatz berechneten Ergebnissen verglichen und diskutiert. Die Ergebnisse der Studie werden so zur Entwicklung zuverlässigerer Berechnungsmethoden für Critical Loads in Baden-Württemberg beitragen. Auf dem Poster werden die methodischen Ansätze sowie erste Ergebnisse des Versuchs vorgestellt
High-throughput field phenotyping reveals genetic variation in photosynthetic traits in durum wheat under drought
Chlorophyll fluorescence (ChlF) is a powerful non-invasive technique for probing photosynthesis. Although proposed as a method for drought tolerance screening, ChlF has not yet been fully adopted in physiological breeding, mainly due to limitations in high-throughput field phenotyping capabilities. The light-induced fluorescence transient (LIFT) sensor has recently been shown to reliably provide active ChlF data for rapid and remote characterisation of plant photosynthetic performance. We used the LIFT sensor to quantify photosynthesis traits across time in a large panel of durum wheat genotypes subjected to a progressive drought in replicated field trials over two growing seasons. The photosynthetic performance was measured at the canopy level by means of the operating efficiency of Photosystem II ((Formula presented.)) and the kinetics of electron transport measured by reoxidation rates ((Formula presented.) and (Formula presented.)). Short- and long-term changes in ChlF traits were found in response to soil water availability and due to interactions with weather fluctuations. In mild drought, (Formula presented.) and (Formula presented.) were little affected, while (Formula presented.) was consistently accelerated in water-limited compared to well-watered plants, increasingly so with rising vapour pressure deficit. This high-throughput approach allowed assessment of the native genetic diversity in ChlF traits while considering the diurnal dynamics of photosynthesis
Farmer Participatory Early-Generation Yield Testing of Sorghum in West Africa: Possibilities to Optimize Genetic Gains for Yield in Farmers’ Fields
The effectiveness of on-farm and/or on-station early generation yield testing was examined to maximize the genetic gains for sorghum yield under smallholder famer production conditions in West Africa. On-farm first-stage yield trials (augmented design, 150 genotypes with subsets of 50 genotypes tested per farmer) and second-stage yield trials (replicated α-lattice design, 21 test genotypes) were conducted, as well as on-station α-lattice first- and second-stage trials under contrasting phosphorous conditions. On-farm testing was effective, with yield showing significant genetic variance and acceptable heritabilities (0.56 in first- and 0.61 to 0.83 in second-stage trials). Predicted genetic gains from on-station yield trials were always less than from direct testing on-farm, although on-station trials under low-phosphorus and combined over multiple environments improved selection efficiencies. Modeling alternative designs for on-farm yield testing (augmented, farmer-as-incomplete-block, multiple lattice, and augmented p-rep) indicated that acceptable heritabilities (0.57 to 0.65) could be obtained with all designs for testing 150 progenies in 20 trials and 75 plots per farmer. Ease of implementation and risk of errors would thus be key criteria for choice of design. Integrating results from on-station and on-farm yield testing appeared beneficial as progenies selected both by on-farm and on-station first-stage trials showed higher on-farm yields in second-stage testing
Gene and QTL detection in a three-way barley cross under selection by a mixed model with kinship information using SNPs
Quantitative trait locus (QTL) detection is commonly performed by analysis of designed segregating populations derived from two inbred parental lines, where absence of selection, mutation and genetic drift is assumed. Even for designed populations, selection cannot always be avoided, with as consequence varying correlation between genotypes instead of uniform correlation. Akin to linkage disequilibrium mapping, ignoring this type of genetic relatedness will increase the rate of false-positives. In this paper, we advocate using mixed models including genetic relatedness, or ‘kinship’ information for QTL detection in populations where selection forces operated. We demonstrate our case with a three-way barley cross, designed to segregate for dwarfing, vernalization and spike morphology genes, in which selection occurred. The population of 161 inbred lines was screened with 1,536 single nucleotide polymorphisms (SNPs), and used for gene and QTL detection. The coefficient of coancestry matrix was estimated based on the SNPs and imposed to structure the distribution of random genotypic effects. The model incorporating kinship, coancestry, information was consistently superior to the one without kinship (according to the Akaike information criterion). We show, for three traits, that ignoring the coancestry information results in an unrealistically high number of marker–trait associations, without providing clear conclusions about QTL locations. We used a number of widely recognized dwarfing and vernalization genes known to segregate in the studied population as landmarks or references to assess the agreement of the mapping results with a priori candidate gene expectations. Additional QTLs to the major genes were detected for all traits as well
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