TY  - GEN
A1  - Ellis, S. C.
A1  - Bauer, S.
A1  - Bacigalupo, C.
A1  - Bland-Hawthorn, J.
A1  - Bryant, J. J.
A1  - Case, S.
A1  - Content, R.
A1  - Fechner, T.
A1  - Giannone, D.
A1  - Haynes, R.
A1  - Hernandez, E.
A1  - Horton, A. J.
A1  - Klauser, U.
A1  - Lawrence, J. S.
A1  - Leon-Saval, S. G.
A1  - Lindley, E.
A1  - Löhmannsröben, Hans-Gerd
A1  - Min, S. -S.
A1  - Pai, N.
A1  - Roth, M.
A1  - Shortridge, K.
A1  - Waller, L.
A1  - Xavier, Pascal
A1  - Zhelem, Ross
T1  - PRAXIS: an OH suppression optimised near infrared spectrograph
T2  - Ground-based and Airborne Instrumentation for Astronomy VII
N2  - The problem of atmospheric emission from OH molecules is a long standing problem for near-infrared astronomy. PRAXIS is a unique spectrograph which is fed by fibres that remove the OH background and is optimised specifically to benefit from OH-Suppression. The OH suppression is achieved with fibre Bragg gratings, which were tested successfully on the GNOSIS instrument. PRAXIS uses the same fibre Bragg gratings as GNOSIS in its first implementation, and will exploit new, cheaper and more efficient, multicore fibre Bragg gratings in the second implementation. The OH lines are suppressed by a factor of similar to 1000, and the expected increase in the signal-to-noise in the interline regions compared to GNOSIS is a factor of similar to 9 with the GNOSIS gratings and a factor of similar to 17 with the new gratings. PRAXIS will enable the full exploitation of OH suppression for the first time, which was not achieved by GNOSIS (a retrofit to an existing instrument that was not OH-Suppression optimised) due to high thermal emission, low spectrograph transmission and detector noise. PRAXIS has extremely low thermal emission, through the cooling of all significantly emitting parts, including the fore-optics, the fibre Bragg gratings, a long length of fibre, and the fibre slit, and an optical design that minimises leaks of thermal emission from outside the spectrograph. PRAXIS has low detector noise through the use of a Hawaii-2RG detector, and a high throughput through a efficient VPH based spectrograph. PRAXIS will determine the absolute level of the interline continuum and enable observations of individual objects via an IFU. In this paper we give a status update and report on acceptance tests.
KW  - Near infrared
KW  - spectroscopy
KW  - OH suppression
KW  - astrophotonics
KW  - fibre Bragg gratings
Y1  - 2018
SN  - 978-1-5106-1958-6
U6  - https://doi.org/10.1117/12.2311898
SN  - 0277-786X
SN  - 1996-756X
VL  - 10702
PB  - SPIE-INT Soc Optical Engineering
CY  - Bellingham
ER  - 
TY  - JOUR
A1  - Krause, Sascha
A1  - Le Roux, Xavier
A1  - Niklaus, Pascal A.
A1  - Van Bodegom, Peter M.
A1  - Lennon, Jay T.
A1  - Bertilsson, Stefan
A1  - Grossart, Hans-Peter
A1  - Philippot, Laurent
A1  - Bodelier, Paul L. E.
T1  - Trait-based approaches for understanding microbial biodiversity and ecosystem functioning
JF  - Frontiers in microbiology
N2  - In ecology, biodiversity-ecosystem functioning (BEE) research has seen a shift in perspective from taxonomy to function in the last two decades, with successful application of trait-based approaches. This shift offers opportunities for a deeper mechanistic understanding of the role of biodiversity in maintaining multiple ecosystem processes and services. In this paper, we highlight studies that have focused on BEE of microbial communities with an emphasis on integrating trait-based approaches to microbial ecology. In doing so, we explore some of the inherent challenges and opportunities of understanding BEE using microbial systems. For example, microbial biologists characterize communities using gene phylogenies that are often unable to resolve functional traits. Additionally, experimental designs of existing microbial BEE studies are often inadequate to unravel BEE relationships. We argue that combining eco-physiological studies with contemporary molecular tools in a trait-based framework can reinforce our ability to link microbial diversity to ecosystem processes. We conclude that such trait-based approaches are a promising framework to increase the understanding of microbial BEE relationships and thus generating systematic principles in microbial ecology and more generally ecology.
KW  - functional traits
KW  - ecosystem function
KW  - ecological theory
KW  - study designs
KW  - microbial diversity
Y1  - 2014
U6  - https://doi.org/10.3389/fmicb.2014.00251
SN  - 1664-302X
VL  - 5
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Allan, Eric
A1  - Weisser, Wolfgang W.
A1  - Fischer, Markus
A1  - Schulze, Ernst-Detlef
A1  - Weigelt, Alexandra
A1  - Roscher, Christiane
A1  - Baade, Jussi
A1  - Barnard, Romain L.
A1  - Bessler, Holger
A1  - Buchmann, Nina
A1  - Ebeling, Anne
A1  - Eisenhauer, Nico
A1  - Engels, Christof
A1  - Fergus, Alexander J. F.
A1  - Gleixner, Gerd
A1  - Gubsch, Marlen
A1  - Halle, Stefan
A1  - Klein, Alexandra-Maria
A1  - Kertscher, Ilona
A1  - Kuu, Annely
A1  - Lange, Markus
A1  - Le Roux, Xavier
A1  - Meyer, Sebastian T.
A1  - Migunova, Varvara D.
A1  - Milcu, Alexandru
A1  - Niklaus, Pascal A.
A1  - Oelmann, Yvonne
A1  - Pasalic, Esther
A1  - Petermann, Jana S.
A1  - Poly, Franck
A1  - Rottstock, Tanja
A1  - Sabais, Alexander C. W.
A1  - Scherber, Christoph
A1  - Scherer-Lorenzen, Michael
A1  - Scheu, Stefan
A1  - Steinbeiss, Sibylle
A1  - Schwichtenberg, Guido
A1  - Temperton, Vicky
A1  - Tscharntke, Teja
A1  - Voigt, Winfried
A1  - Wilcke, Wolfgang
A1  - Wirth, Christian
A1  - Schmid, Bernhard
T1  - A comparison of the strength of biodiversity effects across multiple functions
JF  - Oecologia
N2  - In order to predict which ecosystem functions are most at risk from biodiversity loss, meta-analyses have generalised results from biodiversity experiments over different sites and ecosystem types. In contrast, comparing the strength of biodiversity effects across a large number of ecosystem processes measured in a single experiment permits more direct comparisons. Here, we present an analysis of 418 separate measures of 38 ecosystem processes. Overall, 45 % of processes were significantly affected by plant species richness, suggesting that, while diversity affects a large number of processes not all respond to biodiversity. We therefore compared the strength of plant diversity effects between different categories of ecosystem processes, grouping processes according to the year of measurement, their biogeochemical cycle, trophic level and compartment (above- or belowground) and according to whether they were measures of biodiversity or other ecosystem processes, biotic or abiotic and static or dynamic. Overall, and for several individual processes, we found that biodiversity effects became stronger over time. Measures of the carbon cycle were also affected more strongly by plant species richness than were the measures associated with the nitrogen cycle. Further, we found greater plant species richness effects on measures of biodiversity than on other processes. The differential effects of plant diversity on the various types of ecosystem processes indicate that future research and political effort should shift from a general debate about whether biodiversity loss impairs ecosystem functions to focussing on the specific functions of interest and ways to preserve them individually or in combination.
KW  - Bottom-up effects
KW  - Carbon cycling
KW  - Ecological synthesis
KW  - Ecosystem processes
KW  - Grasslands
KW  - Jena experiment
KW  - Nitrogen cycling
Y1  - 2013
U6  - https://doi.org/10.1007/s00442-012-2589-0
SN  - 0029-8549
VL  - 173
IS  - 1
SP  - 223
EP  - 237
PB  - Springer
CY  - New York
ER  -