Genetic variation for nutrient use efficiency in maize under different tillage and fertilization regimes with special emphasis to plant microbe interaction

Conservation tillage (no-till and reduced tillage) brings many benefits with respect to soil fertility and energy use, but it also has drawbacks regarding the need for synthetic fertilizers and herbicides. To promote conversation tillage in organic farming systems, crop rotation, fertilization and weed control have to be optimized. In addition, crop varieties are needed with improved nutrient use efficiency (NUE) and high weed competitiveness or tolerance

Diversity and Relationships among U.S. Maize Inbreds Revealed by Restriction Fragment Length Polymorphisms

Restriction fragment length polymorphisms (RFLPs) have been proposed as molecular markers for characterizing the genetic diversity in maize (Zea mays L.). The objectives of this study were to evaluate the usefulness of RFLP data for (i) elucidating heterotic patterns among maize inbreds and (ii) assessing genetic similarity among related and unrelated lines. Thirty-two maize inbreds from the U.S. Corn Belt were analyzed for RFLPs with two restriction enzymes and 83 DNA probes distributed over the maize genome. Eighty-two probes detected polymorphisms with at least one enzyme. On average, 4.3 variants were found per probe-enzyme combination across all 32 inbreds. Genetic distances among lines, estimated from RFLP data as Rogers\u27 distance (RD), revealed considerable diversity among lines from Iowa Stiff Stalk Synthetic (BSSS), Reid Yellow Dent (RYD), and Lancaster Sure Crop (LSC). Lines from different heterotic groups had a slightly greater RD mean than unrelated lines from the same heterotic group, yet differences were small when compared with the wide range of RDs for individual lines combinations within each group. RDs between related lines agreed well with expectations based on coancestry coefficients determined from pedigree data with few exceptions. Principal component analyses of RFLP data resulted in a separate grouping of lines from BSSS/RYD and LSC. Dispersion of lines of miscellaneous origins was generally consistent with expectations based on known breeding behavior and pedigrees. Results from this study suggest that RFLP data can be used for assigning inbreds into heterotic groups and quantifying genetic similarity between related lines, but it seems that a large number of probe-enzyme combinations are required to obtain reliable estimates of genetic distance

Genetic diversity among progenitors and elite lines from the Iowa Stiff Stalk Synthetic (BSSS) maize population: comparison of allozyme and RFLP data

Data for restriction fragment length polymorphisms (RFLPs) of 144 clone-enzyme combinations and for 22 allozyme loci from 21 U.S. Corn Belt maize (Zea mays L.) inbreds were analyzed. The genetic materials included 14 progenitors of the Iowa Stiff Stalk Synthetic (BSSS) maize population, both parents of one missing BSSS progenitor, four elite inbreds derived from BSSS, and inbred Mo17. Objectives were to characterize the genetic variation among these 21 inbreds for both allozymes and RFLPs, to compare the results from both types of molecular markers, and to estimate the proportion of unique alleles in the BSSS progenitors. Genetic diversity among the 21 inbreds was substantially greater for RFLPs than for allozymes, but the percentages of unique RFLP variants (27%) and unique allozyme alleles (25%) in the BSSS progenitors were similar. Genetic distances between inbreds, estimated as Rogers\u27 distance (RD), were, on average, twice as large for RFLP (0.51) as for allozyme data (0.24). RDs obtained from allozyme and RFLP data for individual line combinations were only poorly correlated (r = 0.23); possible reasons for discrepancies are discussed. Principal component analysis of RFLP data, in contrast to allozyme data, resulted in separate groupings of the ten BSSS progenitors derived from the ‘Reid Yellow Dent’ population, the four BSSS elite lines, and Mo17. The remaining six BSSS progenitors were genetically rather diverse and contributed a large number of rare alleles to BSSS. The results of this study corroborate the fact that RFLPs are superior to allozymes for characterizing the genetic diversity of maize breeding materials, because of (1) the almost unlimited number of markers available and (2) the greater amount of polymorphisms found. In particular, RFLPs allow related lines and inbreds with common genetic background to be identified, but a large number of probe-enzyme combinations is needed to estimate genetic distances with the precision required

Interdisziplinäres Schockraum-Management unfallchirurgischer Patienten aus der Sicht der Mitarbeitenden

Zusammenfassung: Einleitung: Wir untersuchten, ob die Mitarbeiterbefragung in der Qualitätskontrolle des Schockraum-Managements von Nutzen sein kann. Methode: Konsekutive anonyme schriftliche Befragung (15Fragen, Likert-Skala 1-5) der klinisch Mitarbeitenden aller Schockraumeinsätze mit Verdacht auf Mehrfachverletzung von Juli 2002 bis Dezember 2003 (Anova; p<0,05). Ergebnisse: Bei 171 unfallchirurgischen Einsätzen retournierten 884Beteiligte den Antwortbogen. Die Beobachtungen der Mitarbeitenden hingen signifikant von der jeweiligen Schockraumsituation ab. Am meisten kritisiert wurden das Zeitmanagement und die eigene Ausbildung (Likert-Skala <4). Leitende- und Oberärzte bewerteten ihren Ausbildungsstand besser als Assistenzärzte und hatten häufiger einen ATLS®-Kurs absolviert (p<0,001). Es fanden sich signifikante systematische Unterschiede in den Beurteilungen, z.B. je nach Fachdisziplin der Antwortenden. Schlussfolgerung: Unser Fragebogen erwies sich als gut diskriminierendes Instrument und kann somit die Erfassung klinischer Parameter im Qualitätsmanagement der Schockraumphase sinnvoll ergänzen. Vor einer breiteren Anwendung werden allerdings zusätzliche Validierungs- und Korrelationsuntersuchungen benötig

A network traffic flow model for motorway and urban highways

The research reported in this paper develops a network level traffic flow model (NTFM) which is applicable for both motorway and urban roads. It forecasts the traffic flow rates, queue propagation at the junctions and travel delays through the network. NTFM uses sub-models associated with all road and junction types which comprise the highway. The flow at any one part of the network is obviously very dependent upon the flows at all other parts of the network. To predict the two-way traffic flow in NTFM, an iterative simulation method is executed to generate the evolution of dependent traffic flows and queues. To demonstrate the capability of the model it is applied to a small case study network and a local Loughborough-Nottingham highway network. The results indicate that NTFM is capable of identifying the relationship between traffic flows and capturing traffic phenomena such as queue dynamics. By introducing a reduced flow rate on links of the network then the effects of strategies employed to carry out roadworks can be mimicked

Temporal Correlation of Hard X-rays and Meter/Decimeter Radio Structures in Solar Flares

We investigate the relative timing between hard X-ray (HXR) peaks and structures in metric and decimetric radio emissions of solar flares using data from the RHESSI and Phoenix-2 instruments. The radio events under consideration are predominantly classified as type III bursts, decimetric pulsations and patches. The RHESSI data are demodulated using special techniques appropriate for a Phoenix-2 temporal resolution of 0.1s. The absolute timing accuracy of the two instruments is found to be about 170 ms, and much better on the average. It is found that type III radio groups often coincide with enhanced HXR emission, but only a relatively small fraction ($\sim$ 20%) of the groups show close correlation on time scales $<$ 1s. If structures correlate, the HXRs precede the type III emissions in a majority of cases, and by 0.69$\pm$0.19 s on the average. Reversed drift type III bursts are also delayed, but high-frequency and harmonic emission is retarded less. The decimetric pulsations and patches (DCIM) have a larger scatter of delays, but do not have a statistically significant sign or an average different from zero. The time delay does not show a center-to-limb variation excluding simple propagation effects. The delay by scattering near the source region is suggested to be the most efficient process on the average for delaying type III radio emission

Survey on solar X-ray flares and associated coherent radio emissions

The radio emission during 201 X-ray selected solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zurich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June 30, 2003. Detailed association rates of radio emission during X-ray flares are reported. In the decimeter wavelength range, type III bursts and the genuinely decimetric emissions (pulsations, continua, and narrowband spikes) were found equally frequently. Both occur predominantly in the peak phase of hard X-ray (HXR) emission, but are less in tune with HXRs than the high-frequency continuum exceeding 4 GHz, attributed to gyrosynchrotron radiation. In 10% of the HXR flares, an intense radiation of the above genuine decimetric types followed in the decay phase or later. Classic meter-wave type III bursts are associated in 33% of all HXR flares, but only in 4% they are the exclusive radio emission. Noise storms were the only radio emission in 5% of the HXR flares, some of them with extended duration. Despite the spatial association (same active region), the noise storm variations are found to be only loosely correlated in time with the X-ray flux. In a surprising 17% of the HXR flares, no coherent radio emission was found in the extremely broad band surveyed. The association but loose correlation between HXR and coherent radio emission is interpreted by multiple reconnection sites connected by common field lines.Comment: Solar Physics, in pres

Application of network traffic flow model to road maintenance

The study shows how the evolution of two-way traffic flows on a local highway network can be predicted over time using a network-level traffic flow model (NTFM) to model both urban and motorway road networks. After a brief review of the main principles of the NTFM and its associated sub-models, the paper describes how a maintenance worksite can be modelled using a roadwork-node sub-model and a network solution routine in the NTFM. In order to model the two-way traffic flow in the road network, an iterative simulation method is used to generate the evolution of dependent traffic flows and queues. The NTFM has been applied to model the traffic characteristics and the effects of maintenance activities on the local Loughborough–Nottingham highway network. The study has demonstrated that the methodology is useful in selecting various worksite arrangements in order to reduce the effects of maintenance on road users