Potential of ten alternative grass species under different cutting regimes in Central Europe

Die Bedeutung von mehrjährigem Grasland als großflächige CO2-Senke ist hoch. Auf diesen Flächen könnten neben Futtermitteln auch Nachwachsende Rohstoffe ökologisch verträglich produziert werden. Aufgrund des fortschreitenden Klimawandels werden die Grünlandflächen Mitteleuropas künftig häufiger von Trockenheit betroffen sein als bisher.Um deren Anbaupotenzial unter mitteleuropäischen Bedingungen zu testen, wurden zehn trockentolerante Gräser (Agropyron elongatum, Agropyron intermedium, Agropyron desertorum, Agropyron trachycaulum, Elymus hoffmannii, Elymus junceus, Bromus inermis, Bromus marginatus, Festuca arundinacea und Panicum virgatum) angebaut und mit vier standortüblichen, leistungsfähigen Futtergräsern in Vergleich gestellt (Dactylis glomerata, Arrhenatherum elatius, Agrostis gigantea und Agropyron repens). Die Parzellenversuche wurden an zwei Stand­orten über zwei Versuchsjahre bei Ein- und Mehrschnittnutzung durchgeführt.Bei Einschnittnutzung lieferte P. virgatum den höchsten bereinigten Jahresertrag (14 258 kg TM ha–1), gefolgt von A. elongatum (13 086 kg TM ha–1). Die mehrjährige Ausdauer dieser zwei Arten war unter den Versuchs­bedingungen aber nur gegeben, wenn P. virgatum nicht vor dem Abfrosten und A. elongatum nur einmal pro Jahr geerntet wurde. Die Lageranfälligkeit der beiden Arten muss beachtet werden. Bei Mehrschnittnutzung konnte F. arundinacea sowohl in der Ertragshöhe (12 533 kg TM ha–1 korrigierter Jahresertrag) als auch durch das geringe Aufkommen an Begleitflora (0,1% Fläche) überzeugen. Beim Anbau dieser Grasart ist die nur mäßige Konkurrenzkraft während der Etablierungsphase zu berücksichtigen. Aufgrund der raschen Jungendentwicklung von A. trachycaulum wird erwartet, dass sich die Art für den Einsatz als Deckfrucht in Saatgutmischungen eignet. A. desertorum, A. trachycaulum, A. repens, E. junceus und B. marginatus lagen im Ertrag unterhalb des Versuchsdurchschnittes (9254,5 kg DM ha–1 bei Zweischnittnutzung). DOI: 10.5073/JfK.2014.06.01, https://doi.org/10.5073/JfK.2014.06.01Perennial grasslands play an important role as an extensive CO2 sink. Fodder and biofuels can be produced in an ecologically acceptable manner on such sites. Projected future climate-change scenarios suggest that Central Europe’s grasslands will be increasingly affected by drought. In order to determine whether there is potential for some alternative drought-adapted grass species to contribute to herbage production for either forage or biomass, we tested the agronomic performance of ten grass species (Agropyron elongatum, Agropyron intermedium, Agropyron desertorum, Agropyron trachycaulum, Elymus hoffmannii, Elymus junceus, Bromus inermis, Bromus marginatus, Festuca arundinacea and Panicum virgatum) in comparison to four reference grasses (Dactylis glomerata, Arrhenatherum elatius, Agrostis gigantea and Agropyron repens). Experiments were conducted in small-plot cutting trials at two sites across two growing seasons with either one or multiple cuts per season.In the one-cut system, P. virgatum provided the highest average annual dry matter (DM) yield (14 258 kg ha–1), followed by A. elongatum (13 086 kg ha–1). The multi-annual persistence of these two species under the experimental conditions was given only when P. virgatum was not harvested before freezing off and A. elongatum was harvested only once per year. Moreover, both species are susceptible to lodging. In the multiple-cut system, F. arundinacea showed a high yield (12 533 kg DM ha–1 average annual yield) and a low presence of associated weeds (only 0.1% surface area). Cultivating this grass species requires considering its only moderate competitiveness during the establishment phase. Based on the rapid establishment of A. trachycaulum, this species is expected to be best suited as a cover crop in seed mixtures. The yields of A. desertorum, A. trachycaulum, A. repens, E. junceus and B. marginatus were below the experimental average (9255 kg DM ha–1 at multiple cuttings). DOI: 10.5073/JfK.2014.06.01, https://doi.org/10.5073/JfK.2014.06.0

A Falsification of the Citation Impediment in the Taxonomic Literature

Current science evaluation still relies on citation performance, despite criticisms of purely bibliometric research assessments. Biological taxonomy suffers from a drain of knowledge and manpower, with poor citation performance commonly held as one reason for this impediment. But is there really such a citation impediment in taxonomy? We compared the citation numbers of 306 taxonomic and 2291 non-taxonomic research articles (2009-2012) on mosses, orchids, ciliates, ants, and snakes, using Web of Science (WoS) and correcting for journal visibility. For three of the five taxa, significant differences were absent in citation numbers between taxonomic and non-taxonomic papers. This was also true for all taxa combined, although taxonomic papers received more citations than non-taxonomic ones. Our results show that, contrary to common belief, taxonomic contributions do not generally reduce a journal's citation performance and might even increase it. The scope of many journals rarely featuring taxonomy would allow editors to encourage a larger number of taxonomic submissions. Moreover, between 1993 and 2012, taxonomic publications accumulated faster than those from all biological fields. However, less than half of the taxonomic studies were published in journals in WoS. Thus, editors of highly visible journals inviting taxonomic contributions could benefit from taxonomy's strong momentum. The taxonomic output could increase even more than at its current growth rate if: (i) taxonomists currently publishing on other topics returned to taxonomy and (ii) non-taxonomists identifying the need for taxonomic acts started publishing these, possibly in collaboration with taxonomists. Finally, considering the high number of taxonomic papers attracted by the journal Zootaxa, we expect that the taxonomic community would indeed use increased chances of publishing in WoS indexed journals. We conclude that taxonomy's standing in the present citation-focused scientific landscape could easily improve—if the community becomes aware that there is no citation impediment in taxonom

Apollo Lightcraft Project

The ultimate goal for this NASA/USRA-sponsored Apollo Lightcraft Project is to develop a revolutionary manned launch vehicle technology which can potentially reduce payload transport costs by a factor of 1000 below the Space Shuttle Orbiter. The Rensselaer design team proposes to utilize advanced, highly energetic, beamed-energy sources (laser, microwave) and innovative combined-cycle (airbreathing/rocket) engines to accomplish this goal. The research effort focuses on the concept of a 100 MW-class, laser-boosted Lightcraft Technology Demonstrator (LTD) drone. The preliminary conceptual design of this 1.4 meter diameter microspacecraft involved an analytical performance analysis of the transatmospheric engine in its two modes of operation (including an assessment of propellant and tankage requirements), and a detailed design of internal structure and external aeroshell configuration. The central theme of this advanced propulsion research was to pick a known excellent working fluid (i.e., air or LN sub 2), and then to design a combined-cycle engine concept around it. Also, a structural vibration analysis was performed on the annular shroud pulsejet engine. Finally, the sensor satellite mission was examined to identify the requisite subsystem hardware: e.g., electrical power supply, optics and sensors, communications and attitude control systems

Allele Intersection Analysis: A Novel Tool for Multi Locus Sequence Assignment in Multiply Infected Hosts

Wolbachia are wide-spread, endogenous α-Proteobacteria of arthropods and filarial nematodes. 15–75% of all insect species are infected with these endosymbionts that alter their host's reproduction to facilitate their spread. In recent years, many insect species infected with multiple Wolbachia strains have been identified. As the endosymbionts are not cultivable outside living cells, strain typing relies on molecular methods. A Multi Locus Sequence Typing (MLST) system was established for standardizing Wolbachia strain identification. However, MLST requires hosts to harbour individual and not multiple strains of supergroups without recombination. This study revisits the applicability of the current MLST protocols and introduces Allele Intersection Analysis (AIA) as a novel approach. AIA utilizes natural variations in infection patterns and allows correct strain assignment of MLST alleles in multiply infected host species without the need of artificial strain segregation. AIA identifies pairs of multiply infected individuals that share Wolbachia and differ in only one strain. In such pairs, the shared MLST sequences can be used to assign alleles to distinct strains. Furthermore, AIA is a powerful tool to detect recombination events. The underlying principle of AIA may easily be adopted for MLST approaches in other uncultivable bacterial genera that occur as multiple strain infections and the concept may find application in metagenomic high-throughput parallel sequencing projects

Statistical Training for a Large Number of Students

AbstractAt the University of Natural Resources and Life Sciences in Vienna the number of newly enrolled students increased from 696 to 3025 within the last 13 years, but the scientific staff of the statistical institute remained unchanged and consists of 4 people. About 60% of these students have to pass an introductory course in statistics at the Institute of Applied Statistics and Computing. So, depending on the branch of study, 200 to 500 students have to be supervised. As it is hardly possible to train such a high number of students, an online program was developed. It allows ongoing control of knowledge without excessively burdening the scientific staff. In addition, a program was developed, which creates test tasks for a final multiple choice test. These tasks are randomly selected from an appropriate database. Test results are automatically evaluated and graded. As this specific way of education is practiced for about 15 years, capabilities, advantages and disadvantages can be evaluated

The two-sample t test: pre-testing its assumptions does not pay off

Pre-tests, Two-sample t test, Welch-test, Wilcoxon-U test,

8th International Workshop on Simulation

This volume features original contributions and invited review articles on mathematical statistics, statistical simulation and experimental design. The selected peer-reviewed contributions originate from the 8th International Workshop on Simulation held in Vienna in 2015. The book is intended for mathematical statisticians, Ph.D. students and statisticians working in medicine, engineering, pharmacy, psychology, agriculture and other related fields. The International Workshops on Simulation are devoted to statistical techniques in stochastic simulation, data collection, design of scientific experiments and studies representing broad areas of interest. The first 6 workshops took place in St. Petersburg, Russia, in 1994 – 2009 and the 7th workshop was held in Rimini, Italy, in 2013

Biometric Unit

Tests of additivity in mixed and fixed effect two-way ANOVA models with single sub-class numbers Article (Accepted for Publication) (Refereed