Nature of mixed infection type 2(5) observed in rye (Secale cereale L.) plants carrying the Pr1 leaf-rust resistance gene

Bei der Inokulation von Trägern des dominanten Braunrostresistenzgens Pr1 mit einer komplexen Braunrostpopulation kommt es vorwiegend zur Entwicklung eines gemischten Infektionstyps IT 2(5). In der hier vorgestellten Studie wurde die Entstehung dieses gemischten Infektionstyps untersucht. Die Ergebnisse belegen, dass IT 2(5) weder durch partielle Dominanz des Resistenzgens Pr1, noch durch Einflüsse des genetischen Hintergrundes verursacht wird. Die Entstehung von IT 2(5) liegt vielmehr in der Existenz einer Pr1-virulenten Braunrostrasse im verwendeten Inokulum begründet, die in einer niedrigen Frequenz auftritt. Mit Hilfe eines einfachen Versuchsansatzes wurde die Frequenz der Pr1-virulenten Braunrostrasse in der verwendeten Braunrostpopulation geschätzt. Hierbei wurden vergleichende Blattsegmenttests von Pr1-Trägern und Genotypen ohne Pr1 durch­geführt und die bei beiden Genotypen erfassten Pustelanzahlen zueinander in Beziehung gesetzt. Im vorliegenden Fall wurde für die Pr1-virulente Braunrostrasse innerhalb einer im Feld gesammelten lokalen Braunrostpopulation eine Frequenz von 3,19% geschätzt. Durch ein Validierungsexperiment, in dem eine aus einer Pr1-virulenten und einer Pr1-avirulenten Braunrostrasse erstellte Rostpopulation eingesetzt wurde, konnte die geschätzte Frequenz bestätigt werden.When challenged with a complex leaf-rust inoculum, rye plants carrying the dominant leaf-rust resistance gene Pr1 predominantly react with a mixed infection type, IT 2(5). The present study investigates the nature of this mixed infection type. The results demonstrate, that IT 2(5) is not caused by partial dominance of Pr1 nor by the genetic background. Rather, IT 2(5) reflects the occurrence of Pr1-virulent leaf-rust races among the inoculum in low frequency. A simple approach was followed to estimate the frequency of Pr1-virulent races in a leaf-rust population. This approach included comparative detached-leaf testing of Pr1 carriers and Pr1-deficient genotypes and relating the numbers of pustules observed on both genotypes. For the present case we estimated a frequency of 3.19% of Pr1-virulent leaf-rust races among a local leaf-rust population sampled in the field. This estimate was verified in a validation experiment

Contributions of plant breeding to climate protection and to the adaptation to climate change

Die Pflanzenzüchtung kann durch die Entwicklung und Bereitstellung neuer Genotypen in zweierlei Hinsicht dem fortschreitenden Klimawandel begegnen. Zum Einen werden Pflanzensorten zur Verfügung gestellt, die unter geänderten Klima- und Witterungsbedingungen hinreichend stabile Erträge ermöglichen und auf diesem Wege einen wesentlichen Beitrag zur Klimaanpassung der Landwirtschaft leisten. Zum Anderen kann die Entwicklung von Kulturarten und Sorten, die z.B. im Hinblick auf den Düngemitteleinsatz betriebsmitteleffizient sowie in ihrem Flächenertrag auf ihren Einsatz als erneuerbare Energieträger optimiert sind, durch die Einsparung fossiler Energieträger einen aktiven Beitrag zum Klimaschutz darstellen. Eine Strategie zur Verbesserung von Nutzpflanzen als erneuerbare Energieträger ist die agrono­mische Anpassung von bislang wenig verwendeten oder neuen Kulturarten mit hohem Biomassepotenzial an hiesige Produktionsbedingungen. Eine weitere Strategie ist die Anpassung traditioneller Kulturarten an neue Nutzungszwecke und Anbausysteme. In der hier vorgestellten Studie wurden exemplarisch die genetisch-züchterischen Biomassepotenziale der Frucht­arten Sorghumhirse und Winterroggen zur Energieerzeugung untersucht. Dabei zeigten Sorghum bicolor × S. bicolor-Hybriden in einem im Witterungsverlauf begüns­tigten Jahr unter norddeutschen Anbaubedingungen nach Aussaat Ende Juni mit einem Gesamttrockenmasse-Ertrag von maximal 146,3 dt/ha ein sehr hohes Ertragspotenzial, das im Untersuchungsjahr im Leistungs­bereich von Silomais lag. Kühlfeuchte Bedingungen während der Jugendentwicklung führten in einem zweiten Anbaujahr allerdings zu erheblich verminderten Erträgen und zeigten den Bedarf an weiterer züchterischer Anpassung der Sorghumhirse auf. Die Prüfung unterschiedlichen Roggenmaterials zur Biomasseproduktion zeigte zu verschiedenen Schnittzeitpunkten eine hohe züchterisch nutzbare Variabilität und viel versprechende Gesamttrockenmasse-Erträge. Auf Grund der nachgewiesenen Kombination von hoher Eigenleistung mit ansprechendem Heterosiszuwachs erscheint die Entwicklung von Hochleistungsenergie-Hybriden für diese Nutzungsrichtung besonders unter Verwendung von Grünschnittroggen und pflanzengenetischen Ressourcen mittelfristig machbar und viel versprechend. Das Ertragspotenzial des Anbausystems 'Roggen/Sorghum' wird als hoch eingeschätzt und kann nach den vorliegenden Ergebnissen in einem günstigen Anbaujahr auf einen Bereich jenseits von 300 dt/ha Gesamttrocken­masse (GTM) prognostiziert werden. Besonders leistungs­stark erscheint das Anbausystem 'Roggen/Sorghum' dabei im Hinblick auf trockenere Standorte.    Plant breeding has the potential to meet the challenges of a changing climate in two ways. Firstly, plant breeding provides new varieties which offer better yield stability than previous ones under modified climate and weather conditions and, thus, make a substantial contribution to adapt agriculture to the climate change. Secondly, breeding varieties which have improved resource efficiency (e.g., with regard to the use of fertilisers), augmented yields per unit area, and suitability for use as renewable energy sources contributes to active climate protection by saving fossil energy resources. One strategy to improve crop plants for renewable energy production is to agronomically adapt scarcely used or novel crop plants with high biomass potential to local growing conditions. A second one is to adapt traditional crop plants to novel types of use and to dedicated cultivation systems. In the present study, the genetic potentials of (i) sorghum and (ii) rye for biomass production were investigated. After sowing the trial at the end of June and under favourable growing conditions in northern Germany, Sorghum bicolor × S. bicolor-hybrids displayed a very high yield potential of total dry matter yield of 146,3 dt/ha, which was comparable to silage maize yields in that year. However, in a second experimental year, nippy and clammy weather during early growth led to considerably reduced total dry matter yields, showing up the need for further adaptation of sorghum via breeding. Assessment of various rye forms for their biomass production ability revealed (1) high genetic variance reclaim­able for breeding purposes and (2) promising total dry-matter yields. Several entries showed a combination of high population per se performance and significant heterotic increase. Hence, including specific accessions such as forage rye or non-adapted plant genetic resources in the breeding process should enable the development of high-performance energy hybrid rye varieties in the medium-term. Taken together, the genetic biomass potential of the cropping system “rye – sorghum” seems to be high and may be predicted to exceed 300 dt/ha total dry matter under favourable growing conditions.   &nbsp

Rye (Secale cereale L.) for biogas production – Breeding capability

In den vorliegenden Untersuchungen wurde divergentes Roggenmaterial (Populationssorten mit Körner- und Grünschnittnutzung, Hybriden, aktuelles Zuchtmaterial, Tetraploider Roggen, pflanzengenetische Ressourcen (PGR)) in einem zweijährigen Anbau anhand seiner Biomasseleistung auf seine Eignung zur energetischen Nutzung von Roggen überprüft, die erfassten agronomischen Merkmale wurden auf ihre Relevanz für die Biomasse­bildung beurteilt, verschiedene Schnittzeitpunkte zur Biomassenutzung untersucht und über einen NIRS-Ansatz Aussagen über das Gasbildungsvermögen der untersuchten Roggenformen getroffen. Für die Merkmale Gesamttrockenmasseertrag (GTM-Ertrag) und Biogasausbeute zu zwei Grünschnitt-Zeitpunkten – Mitte Ährenschieben und Milchreife – sowie Kornertrag lagen im untersuchten Material signifikante genotypische Varianzen vor. Bei den Grünschnitten 1 und 2 betrugen die mittleren GTM-Erträge 70,1 und 131,9 dt/ha. Grünschnittroggen-Sorten erwiesen sich im 1. Grünschnitt und Hybriden im 2. Grünschnitt als über­legen, wogegen in der Testkreuzungsleistung beim 2. Grünschnitt mehrere Grünschnittroggen und PGRs sowie eine Populationssorte die höchsten GTM-Erträge zeigten. Bei den Grünschnitten 1 und 2 sowie dem Kornertrag ergaben sich beachtliche Heterosiszuwächse von durchschnittlich 9,3%, 11,6% bzw. 32,3%. Bedeutsame Merkmale für die Biomasseproduktion (Wuchshöhe, Termin Ährenschieben, TS-Gehalt) wurden identifiziert und deren Korrelationen berechnet. Die für das Gasbildungsvermögen wesentlichen Inhaltstoffe konnten mittels NIRS-Untersuchungen quantifiziert und die Biogas­ausbeute rechnerisch bestimmt werden. Korrelationen zwischen dem GTM-Ertrag, der Biogasausbeute und dem Ligningehalt wurden ermittelt. Die Ergebnisse unter­streichen das hohe Biomassepotenzial verschiedener Roggen-Materialgruppen für die Bioenergienutzung.The focal points of the present investigation were to examine the suitability of different rye forms (population varieties with forage grain use, hybrids, current breeding material, tetraploid rye, plant genetic resources) for biomass production, to identify the ideal growing stage for harvesting the biomass of these rye forms, to identify relevant traits for biomass production and to estimate their potential of gas production by NIRS analysis. In a two-year trial, significant genetic variances in both the population per se (pps) performance and the testcross performance were demonstrated for total dry matter (TDM) yield at cutting dates 1 and 2 as well as for grain yield. At cutting dates 1 and 2 the average yields amounted to 70.1 and 131.9 dt/ha TDM, respectively. Forage rye materials were superior with regard to TDM yield at cutting date 1 while forage rye, plant genetic resources and a population variety achieved the highest TDM yield at cutting date 2 in the testcross performance. The heterotic increase averaged a substantial level of 9.3%, 11.6% and 32.3% at cutting dates 1 and 2 and for grain yield, respectively. Traits with high relevance for biomass production were identified (height, date of ear emergence, dry mass content) and correlations were calculated. The biogas production of the rye entries was assessed by quantifying the essential ingredients for biogas production via NIRS. Correlations between the TDM yield, the biogas production and the content of lignin were determined. The high capability of different rye forms for bioenergy recovery was underlined

Fast relaxation in a fragile liquid under pressure

The incoherent dynamic structure factor of ortho-terphenyl has been measured by neutron time-of-flight and backscattering technique in the pressure range from 0.1 MPa to 240 MPa for temperatures between 301 K and 335 K. Tagged-particle correlations in the compressed liquid decay in two steps. The alpha-relaxation lineshape is independent of pressure, and the relaxation time proportional to viscosity. A kink in the amplitude f_Q(P) reveals the onset of beta relaxation. The beta-relaxation regime can be described by the mode-coupling scaling function; amplitudes and time scales allow a consistent determination of the critical pressure P_c(T). alpha and beta relaxation depend in the same way on the thermodynamic state; close to the mode-coupling cross-over, this dependence can be parametrised by an effective coupling Gamma ~ n*T**{-1/4}.Comment: 4 Pages of RevTeX, 4 figures (submitted to Physical Review Letters

Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture II: Intermediate Scattering Function and Dynamic Susceptibility

We have performed a molecular dynamics computer simulation of a supercooled binary Lennard-Jones system in order to compare the dynamical behavior of this system with the predictions of the idealized version of mode-coupling theory (MCT). By scaling the time $t$ by the temperature dependent $\alpha$-relaxation time $\tau(T)$, we find that in the $\alpha$-relaxation regime $F(q,t)$ and $F_s(q,t)$, the coherent and incoherent intermediate scattering functions, for different temperatures each follows a $q$-dependent master curve as a function of scaled time. We show that during the early part of the $\alpha$-relaxation, which is equivalent to the late part of the $\beta$-relaxation, these master curves are well approximated by the master curve predicted by MCT for the $\beta$-relaxation. This part is also fitted well by a power-law, the so-called von Schweidler law. We show that the effective exponent $b'$ of this power-law depends on the wave vector $q$ if $q$ is varied over a large range. The early part of the $\beta$-relaxation regime does not show the critical decay predicted by MCT. The $q$-dependence of the nonergodicity parameter for $F_{s}(q,t)$ and $F(q,t)$ are in qualitative agreement with MCT. On the time scale of the late $\alpha$-relaxation the correlation functions show a Kohlrausch-Williams-Watt behavior (KWW). The KWW exponent $\beta$ is significantly different from the effective von Schweidler exponent $b'$. At low temperatures the $\alpha$-relaxation time $\tau(T)$ shows a power-law behavior with a critical temperature that is the same as the one found previously for the diffusion constant [Phys. Rev. Lett. {\bf 73}, 1376 (1994)]. The critical exponent of this power-law and the von Schweidler exponent $b'$ fulfill the connection proposed by MCT between these two quantities. We also show that theComment: 28 Pages of REVTEX, Figures available from W. Ko

Proximity to Sports Facilities and Sports Participation for Adolescents in Germany

Objectives - To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany. Methods - A sample of 1,768 adolescents aged 11–17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities. Results - The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively. Conclusions - Improved proximity to gyms is likely to be more important for female adolescents living in rural areas

Virulence of 32 Salmonella Strains in Mice

Virulence and persistence in the BALB/c mouse gut was tested for 32 strains of Salmonella enterica for which genome sequencing is complete or underway, including 17 serovars within subspecies I (enterica), and two representatives of each of the other five subspecies. Only serovar Paratyphi C strain BAA1715 and serovar Typhimurium strain 14028 were fully virulent in mice. Three divergent atypical Enteritidis strains were not virulent in BALB/c, but two efficiently persisted. Most of the other strains in all six subspecies persisted in the mouse intestinal tract for several weeks in multiple repeat experiments although the frequency and level of persistence varied considerably. Strains with heavily degraded genomes persisted very poorly, if at all. None of the strains tested provided immunity to Typhimurium infection. These data greatly expand on the known significant strain-to-strain variation in mouse virulence and highlight the need for comparative genomic and phenotypic studies

Computational Prediction of Host-Parasite Protein Interactions between P. falciparum and H. sapiens

To obtain candidates of interactions between proteins of the malaria parasite Plasmodium falciparum and the human host, homologous and conserved interactions were inferred from various sources of interaction data. Such candidate interactions were assessed by applying a machine learning approach and further filtered according to expression and molecular characteristics, enabling involved proteins to indeed interact. The analysis of predicted interactions indicated that parasite proteins predominantly target central proteins to take control of a human host cell. Furthermore, parasite proteins utilized their protein repertoire in a combinatorial manner, providing a broad connection to host cellular processes. In particular, several prominent pathways of signaling and regulation proteins were predicted to interact with parasite chaperones. Such a result suggests an important role of remodeling proteins in the interaction interface between the human host and the parasite. Identification of such molecular strategies that allow the parasite to take control of the host has the potential to deepen our understanding of the parasite specific remodeling processes of the host cell and illuminate new avenues of disease intervention

Generational distribution of a Candida glabrata population: Resilient old cells prevail, while younger cells dominate in the vulnerable host.

Similar to other yeasts, the human pathogen Candida glabrata ages when it undergoes asymmetric, finite cell divisions, which determines its replicative lifespan. We sought to investigate if and how aging changes resilience of C. glabrata populations in the host environment. Our data demonstrate that old C. glabrata are more resistant to hydrogen peroxide and neutrophil killing, whereas young cells adhere better to epithelial cell layers. Consequently, virulence of old compared to younger C. glabrata cells is enhanced in the Galleria mellonella infection model. Electron microscopy images of old C. glabrata cells indicate a marked increase in cell wall thickness. Comparison of transcriptomes of old and young C. glabrata cells reveals differential regulation of ergosterol and Hog pathway associated genes as well as adhesion proteins, and suggests that aging is accompanied by remodeling of the fungal cell wall. Biochemical analysis supports this conclusion as older cells exhibit a qualitatively different lipid composition, leading to the observed increased emergence of fluconazole resistance when grown in the presence of fluconazole selection pressure. Older C. glabrata cells accumulate during murine and human infection, which is statistically unlikely without very strong selection. Therefore, we tested the hypothesis that neutrophils constitute the predominant selection pressure in vivo. When we altered experimentally the selection pressure by antibody-mediated removal of neutrophils, we observed a significantly younger pathogen population in mice. Mathematical modeling confirmed that differential selection of older cells is sufficient to cause the observed demographic shift in the fungal population. Hence our data support the concept that pathogenesis is affected by the generational age distribution of the infecting C. glabrata population in a host. We conclude that replicative aging constitutes an emerging trait, which is selected by the host and may even play an unanticipated role in the transition from a commensal to a pathogen state.post-print10768 K

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries