Assessing acidity impacts in Nordic lakes and streams: Development of a macroinvertebrate-based multimetric index to quantify degradation and recovery

1) Emissions of acidifying compounds have decreased over several decades, nevertheless acidification impacts on aquatic ecosystems remains as a regionally important environmental driver resulting in biodiversity loss and impaired function in many lakes and streams. 2) Many metrics based on macroinvertebrates are currently used to assess the biological impacts of acidification. However, few include measures of community composition, abundance, diversity, and the presence/absence of tolerant/sensitive taxa, and fewer still are calibrated simultaneously for both lentic and lotic waters and across large geographic regions. 3) Data on water chemistry and benthic macroinvertebrates was extracted from a database compiled by representatives from Norway, Sweden and Finland. Using lake-and stream data on water chemistry and macroinvertebrates from Norway and Sweden, we developed a Nordic macroinvertebrate-based multimetric index (MMI) for acidity (NAMI) to assess impacts of and recovery from acidity using information on measures of community structure and traits. 4) Lake and stream datasets were explored together and independently for correlation between measures of community structure and traits to acid neutralizing capacity (ANC), modified ANC regarding 1/3 of the organic acids as strong (ANCo1) and pH. Significantly correlated candidate metrics with highest correlations were chosen using forward stepwise linear regression models against ANC, ANCo1 and pH. Results showed that the combined lake and stream MMI had the highest correlation (r-squared) with ANCo1. 5) Seven metrics were included in NAMI: one measure of composition (sum of the combined relative abundance of Gastropoda, Bivalvia and Crustacea), two measures of diversity (the number of Ephemeroptera taxa excluding leptophlebiids and the number of Bivalvia taxa), one effect trait (taxa with life cycle duration > 1 year), two response traits (taxa with resistance forms: eggs and plastron respiration) and one tolerance trait (preference > 5 pH < 5.5). 6) The NAMI is a promising metric to standardize lake and stream macroinvertebrate assessments of acidity impacts and recovery across the Nordic countries, and to harmonize chemical and biological classifications of water quality, including progress towards achieving international objectives

Tracer Dispersion in a Self-Organized Critical System

We have studied experimentally transport properties in a slowly driven granular system which recently was shown to display self-organized criticality [Frette {\em et al., Nature} {\bf 379}, 49 (1996)]. Tracer particles were added to a pile and their transit times measured. The distribution of transit times is a constant with a crossover to a decaying power law. The average transport velocity decreases with system size. This is due to an increase in the active zone depth with system size. The relaxation processes generate coherently moving regions of grains mixed with convection. This picture is supported by considering transport in a $1D$ cellular automaton modeling the experiment.Comment: 4 pages, RevTex, 1 Encapsulated PostScript and 4 PostScript available upon request, Submitted to Phys. Rev. Let

Benefits Are Better than Harms: A Reply to Feit

We have argued that the counterfactual comparative account of harm and benefit (CCA) violates the plausible adequacy condition that an act that would harm an agent cannot leave her much better off than an alternative act that would benefit her. In a recent paper in this journal, however, Neil Feit objects that our argument presupposes questionable counterfactual backtracking. He also argues that CCA proponents can justifiably reject the condition by invoking so-called plural harm and benefit. In this reply, we argue that Feit’s lines of criticism are both unsuccessful

Off-forward parton distributions and Shuvaev's transformations

We review Shuvaev's transformations, that relate off-forward parton distributions (OFPDs) to so-called effective forward parton distributions (EFPDs). The latter evolve like conventional forward partons. We express nonforward amplitudes, depending on OFPDs, directly in terms of EFPDs and construct a model for the EFPDs, which allows to consistently express them in terms of the conventional forward parton distributions and nucleon form factors. Our model is self-consistent for arbitrary x, xi, mu, and t.Comment: 13 pages, 7 eps-figures, LaTeX2e, added references, corrected typo

Laser-induced fluorescence of free diamondoid molecules

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We observe the fluorescence of pristine diamondoids in the gas phase, excited using narrow band ultraviolet laser light. The emission spectra show well- defined features, which can be attributed to transitions from the excited electronic state into different vibrational modes of the electronic ground state. We assign the normal modes responsible for the vibrational bands, and determine the geometry of the excited states. Calculations indicate that for large diamondoids, the spectral bands do not result from progressions of single modes, but rather from combination bands composed of a large number of Delta v = 1 transitions. The vibrational modes determining the spectral envelope can mainly be assigned to wagging and twisting modes of the surface atoms. We conclude that our theoretical approach accurately describes the photophysics in diamondoids and possibly other hydrocarbons in general.DFG, FOR 1282, Controlling the electronic structure of semiconductor nanoparticles by doping and hybrid formatio

Swedish CLARIN activities

Proceedings of the NODALIDA 2009 workshop Nordic Perspectives on the CLARIN Infrastructure of Language Resources. Editors: Rickard Domeij, Kimmo Koskenniemi, Steven Krauwer, Bente Maegaard, Eiríkur Rögnvaldsson and Koenraad de Smedt. NEALT Proceedings Series, Vol. 5 (2009), 1-5. © 2009 The editors and contributors. Published by Northern European Association for Language Technology (NEALT) http://omilia.uio.no/nealt . Electronically published at Tartu University Library (Estonia) http://hdl.handle.net/10062/9207