Showing papers by "Stockholm University published in 2002"

Resilience and sustainable development: building adaptive capacity in a world of transformations

Abstract: Emerging recognition of two fundamental errors under-pinning past polices for natural resource issues heralds awareness of the need for a worldwide fundamental change in thinking and in practice of environmental management. The first error has been an implicit assumption that ecosystem responses to human use are linear, predictable and controllable. The second has been an assumption that human and natural systems can be treated independently. However, evidence that has been accumulating in diverse regions all over the world suggests that natural and social systems behave in nonlinear ways, exhibit marked thresholds in their dynamics, and that social-ecological systems act as strongly coupled, complex and evolving integrated systems. This article is a summary of a report prepared on behalf of the Environmental Advisory Council to the Swedish Government, as input to the process of the World Summit on Sustainable Development (WSSD) in Johannesburg, South Africa in 26 August 4 September 2002. We use the concept of resilience—the capacity to buffer change, learn and develop—as a framework for understanding how to sustain and enhance adaptive capacity in a complex world of rapid transformations. Two useful tools for resilience-building in social-ecological systems are structured scenarios and active adaptive management. These tools require and facilitate a social context with flexible and open institutions and multi-level governance systems that allow for learning and increase adaptive capacity without foreclosing future development options.

Analysis of Acrylamide, a Carcinogen Formed in Heated Foodstuffs

Abstract: Reaction products (adducts) of acrylamide with N termini of hemoglobin (Hb) are regularly observed in persons without known exposure. The average Hb adduct level measured in Swedish adults is preliminarily estimated to correspond to a daily intake approaching 100 μg of acrylamide. Because this uptake rate could be associated with a considerable cancer risk, it was considered important to identify its origin. It was hypothesized that acrylamide was formed at elevated temperatures in cooking, which was indicated in earlier studies of rats fed fried animal feed. This paper reports the analysis of acrylamide formed during heating of different human foodstuffs. Acrylamide levels in foodstuffs were analyzed by an improved gas chromatographic−mass spectrometric (GC-MS) method after bromination of acrylamide and by a new method for measurement of the underivatized acrylamide by liquid chromatography−mass spectrometry (LC-MS), using the MS/MS mode. For both methods the reproducibility, given as coefficient of vari...

Resilience Management in Social-ecological Systems: a Working Hypothesis for a Participatory Approach

Abstract: Approaches to natural resource management are often based on a presumed ability to predict probabilistic responses to management and external drivers such as climate. They also tend to assume that the manager is outside the system being managed. However, where the objectives include long-term sustainability, linked social-ecological systems (SESs) behave as complex adaptive systems, with the managers as integral components of the system. Moreover, uncertainties are large and it may be difficult to reduce them as fast as the system changes. Sustainability involves maintaining the functionality of a system when it is perturbed, or maintaining the elements needed to renew or reorganize if a large perturbation radically alters structure and function. The ability to do this is termed "resilience." This paper presents an evolving approach to analyzing resilience in SESs, as a basis for managing resilience. We propose a framework with four steps, involving close involvement of SES stakeholders. It begins with a stakeholder-led development of a conceptual model of the system, including its historical profile (how it got to be what it is) and preliminary assessments of the drivers of the supply of key ecosystem goods and services. Step 2 deals with identifying the range of unpredictable and uncontrollable drivers, stakeholder visions for the future, and contrasting possible future policies, weaving these three factors into a limited set of future scenarios. Step 3 uses the outputs from steps 1 and 2 to explore the SES for resilience in an iterative way. It generally includes the development of simple models of the system's dynamics for exploring attributes that affect resilience. Step 4 is a stakeholder evaluation of the process and outcomes in terms of policy and management implications. This approach to resilience analysis is illustrated using two stylized examples.

Daily dataset of 20th‐century surface air temperature and precipitation series for the European Climate Assessment

Abstract: We present a dataset of daily resolution climatic time series that has been compiled for the European Climate Assessment (ECA). As of December 2001, this ECA dataset comprises 199 series of minimum, maximum and/or daily mean temperature and 195 series of daily precipitation amount observed at meteorological stations in Europe and the Middle East. Almost all series cover the standard normal period 1961–90, and about 50% extends back to at least 1925. Part of the dataset (90%) is made available for climate research on CDROM and through the Internet (at http://www.knmi.nl/samenw/eca). A comparison of the ECA dataset with existing gridded datasets, having monthly resolution, shows that correlation coefficients between ECA stations and nearest land grid boxes between 1946 and 1999 are higher than 0.8 for 93% of the temperature series and for 51% of the precipitation series. The overall trends in the ECA dataset are of comparable magnitude to those in the gridded datasets. The potential of the ECA dataset for climate studies is demonstrated in two examples. In the first example, it is shown that the winter (October–March) warming in Europe in the 1976–99 period is accompanied by a positive trend in the number of warm-spell days at most stations, but not by a negative trend in the number of cold-spell days. Instead, the number of cold-spell days increases over Europe. In the second example, it is shown for winter precipitation between 1946 and 1999 that positive trends in the mean amount per wet day prevail in areas that are getting drier and wetter. Because of its daily resolution, the ECA dataset enables a variety of empirical climate studies, including detailed analyses of changes in the occurrence of extremes in relation to changes in mean temperature and total precipitation. Copyright  2002 Royal Meteorological Society.

A comparison of measures of disproportionality for signal detection in spontaneous reporting systems for adverse drug reactions.

Abstract: SUMMARY Purpose A continuous systematic review of all combinations of drugs and suspected adverse reactions (ADRs) reported to a spontaneous reporting system, is necessary to optimize signal detection. To focus attention of human reviewers, quantitative procedures can be used to sift data in different ways. In various centres, different measures are used to quantify the extent to which an ADR is reported disproportionally to a certain drug compared to the generality of the database. The objective of this study is to examine the level of concordance of the various estimates to the measure used by the WHO Collaborating Centre for International ADR monitoring, the information component (IC), when applied to the dataset of the Netherlands Pharmacovigilance Foundation Lareb. Methods The Reporting Odds Ratio � 1.96 standard errors (SE), proportional reporting ratio � 1.96 SE, Yule’s Q � 1.96 SE, the Poisson probability and Chi-square test of all 17 330 combinations were compared with the IC minus 2 standard deviations. Additionally, the concordance of the various tests, in respect to the number of reports per combination, was examined. Results In general, sensitivity was high in respect to the reference measure when a combination of point- and precision estimate was used. The concordance increased dramatically when the number of reports per combination increased. Conclusion This study shows that the different measures used are broadly comparable when four or more cases per combination have been collected. Copyright # 2002 John Wiley & Sons, Ltd.

Spark Plasma Sintering of Alumina

Abstract: A systematic study of various spark plasma sintering (SPS) parameters, namely temperature, holding time, heating rate, pressure, and pulse sequence, was conducted to investigate their effect on the densification, grain-growth kinetics, hardness, and fracture toughness of a commercially available submicrometer-sized Al 2 O 3 powder. The obtained experimental data clearly show that the SPS process enhances both densification and grain growth. Thus, Al 2 O 3 could be fully densified at a much lower temperature (1150°C), within a much shorter time (minutes), than in more conventional sintering processes. It is suggested that the densification is enhanced in the initial part of the sintering cycle by a local spark-discharge process in the vicinity of contacting particles, and that both grain-boundary diffusion and grain-boundary migration are enhanced by the electrical field originating from the pulsed direct current used for heating the sample. Both the diffusion and the migration that promote the grain growth were found to be strongly dependent on temperature, implying that it is possible to retain the original fine-grained structure in fully densified bodies by avoiding a too high sintering temperature. Hardness values in the range 21-22 GPa and fracture toughness values of 3.5 ± 0.5 MPa.m 1/2 were found for the compacts containing submicrometer-sized Al 2 O 3 grains.

Dinitrogen fixation in the world's oceans

Abstract: The surface water of the marine environment has traditionally been viewed as a nitrogen (N) limited habitat, and this has guided the development of conceptual biogeochemical models focusing largely on the reservoir of nitrate as the critical source of N to sustain primary productivity. However, selected groups of Bacteria, including cyanobacteria, and Archaea can utilize dinitrogen (N2) as an alternative N source. In the marine environment, these microorganisms can have profound effects on net community production processes and can impact the coupling of C-N-P cycles as well as the net oceanic sequestration of atmospheric carbon dioxide. As one component of an integrated ‘Nitrogen Transport and Transformations’ project, we have begun to re-assess our understanding of (1) the biotic sources and rates of N2 fixation in the world’s oceans, (2) the major controls on rates of oceanic N2 fixation, (3) the significance of this N2 fixation for the global carbon cycle and (4) the role of human activities in the alteration of oceanic N2 fixation. Preliminary results indicate that rates of N2 fixation, especially in subtropical and tropical open ocean habitats, have a major role in the global marine N budget. Iron (Fe) bioavailability appears to be an important control and is, therefore, critical in extrapolation to global rates of N2 fixation. Anthropogenic perturbations may alter N2 fixation in coastal environments through habitat destruction and eutrophication, and open ocean N2 fixation may be enhanced by warming and increased stratification of the upper water column. Global anthropogenic and climatic changes may also affect N2 fixation rates, for example by altering dust inputs (i.e. Fe) or by expansion of subtropical boundaries. Some recent estimates of global ocean N2 fixation are in the range of 100−200 Tg N (1−2 × 1014 g N) yr −1, but have large uncertainties. These estimates are nearly an order of magnitude greater than historical, pre-1980 estimates, but approach modern estimates of oceanic denitrification.

The Nature of Job Insecurity: Understanding Employment Uncertainty on the Brink of a New Millennium

Abstract: Cet article porte sur la nature de l’insecurite au travail et traite de donnees aussi bien conceptuelles que methodologiques en rapport avec notre comprehension de ses consequences. Une revue de litterature debouche sur le constat qu’il est necessaire de faire appel a nombre de travaux theoriques et empiriques pour cerner la nature de l’insecurite au travail, developper des mesures psychometriquement valides de ses differents aspects et parvenir a des conclusions pertinentes sur les effets de l’insecurite. L’insecurite au travail est d’abord definit comme une source de stress multidimensionnelle relevant de l’experience subjective. Ensuite, les nombreux aspects de l’insecurite au travail peuvent avoir des consequences divergentes ou du moins etre differentiellement relies a des variables dependantes potentielles telles que les attitudes relatives au travail, la performance professionnelle, la sante physique, le bien-etre mental ou les symptomes de stress induits par le travail. Puis, etant donne que la plupart des recherches sur l’insecurite au travail ont ete transversales, il reste a effectuer beaucoup d’investigations avant que nous sachions comment, ou si, l’insecurite contribue a modifier ces variables, Enfin, on peut imaginer nombre de facteurs susceptibles d’avoir un impact sur les relations entre l’insecurite au travail et ses retombees possibles. Pour ameliorer la comprehenions de ce qu’est l’insecurite au travail et de ce qu’elle peut impliquer pour l’individu, il est indispensable de prendre en compte ces donnees dans des recherches aussi bien theoriques qu’empiriques. This paper focuses on the nature of job insecurity and addresses conceptual as well as methodological issues affecting our understanding of its consequences. A review of the literature suggests that a great deal of theoretical and empirical work is needed to capture the nature of job insecurity, develop psychometrically sound measures of the different aspects, and arrive at valid conclusions regarding the effects of insecurity. First, job insecurity is defined as a subjectively experienced stressor which may be divided into different dimensions. Second, the multiple aspects of job insecurity may have divergent consequences or at least be differentially related to potential outcomes such as work-related attitudes, job performance, physical health, mental well-being, and job-induced stress symptoms. Third, given that most studies on job insecurity have been cross-sectional, a lot of work remains before we know how, or if, insecurity contributes to changes in such outcomes. Fourth, there are a number of plausible factors that may moderate the relationships between job insecurity and its potential outcomes. Addressing these issues in theoretical as well as empirical work is necessary, we argue, to improve the understanding of both what job insecurity is and what it may imply for the individual.

Paths to Compliance: Enforcement, Management, and the European Union

Abstract: The contemporary debate on compliance has been framed in terms of two contending perspectives on how to best make states comply with international rules: the enforcement approach and the management approach. Whereas enforcement theorists stress a coercive strategy of monitoring and sanctions, management theorists embrace a problem-solving approach based on capacity building, rule interpretation, and transparency. This article challenges the conception of enforcement and management as competing strategies for achieving compliance. Based on the case of the EU and a comparison with other international regimes, I submit that enforcement and management mechanisms are most effective when combined. The twinning of cooperative and coercive instruments in a “management-enforcement ladder” makes the EU highly successful in combating violations, thus reducing non-compliance to a temporal phenomenon. Regimes in the areas of trade, environment, and human rights lend additional support to this proposition; compliance systems that offer both forms of mechanisms are particularly effective in securing rule conformance, whereas systems that only rely on one of the strategies suffer in identifiable ways.

Structure and bonding of water on Pt(111).

Abstract: We address the adsorption of water on Pt(111) using x-ray absorption, x-ray emission, and x-ray photoelectron spectroscopy along with calculations in the framework of density functional theory. Using the direct relationship between the electronic structure and adsorbate geometry, we show that in the first layer all the molecules bind directly to the surface and to each other through the in-layer H bonds without dissociation, creating a nearly flat overlayer. The water molecules are adsorbed through alternating metal-oxygen (M-O) and metal-hydrogen (M-HO) bonds.

Central Functions of the Lumenal and Peripheral Thylakoid Proteome of Arabidopsis Determined by Experimentation and Genome-Wide Prediction

Abstract: Experimental proteome analysis was combined with a genome-wide prediction screen to characterize the protein content of the thylakoid lumen of Arabidopsis chloroplasts. Soluble thylakoid proteins were separated by two-dimensional electrophoresis and identified by mass spectrometry. The identities of 81 proteins were established, and N termini were sequenced to validate localization prediction. Gene annotation of the identified proteins was corrected by experimental data, and an interesting case of alternative splicing was discovered. Expression of a surprising number of paralogs was detected. Expression of five isomerases of different classes suggests strong (un)folding activity in the thylakoid lumen. These isomerases possibly are connected to a network of peripheral and lumenal proteins involved in antioxidative response, including peroxiredoxins, m-type thioredoxins, and a lumenal ascorbate peroxidase. Characteristics of the experimentally identified lumenal proteins and their orthologs were used for a genome-wide prediction of the lumenal proteome. Lumenal proteins with a typical twin-arginine translocation motif were predicted with good accuracy and sensitivity and included additional isomerases and proteases. Thus, prime functions of the lumenal proteome include assistance in the folding and proteolysis of thylakoid proteins as well as protection against oxidative stress. Many of the predicted lumenal proteins must be present at concentrations at least 10,000-fold lower than proteins of the photosynthetic apparatus.

Formation of tough interlocking microstructures in silicon nitride ceramics by dynamic ripening

Abstract: Ceramics based on Si3N4 have been comprehensively studied and are widely used in structural applications1, 2. The development of an interlocking microstructure of elongated grains is vital to ensur ...

Abundance of harbour porpoise and other cetaceans in the North Sea and adjacent waters

Abstract: 1. The status of small cetaceans in the North Sea and adjacent waters has been of concern for many years. Shipboard and aerial line transect surveys were conducted to provide accurate and precise estimates of abundance as a basis for conservation strategy in European waters. 2. The survey, known as SCANS (Small Cetacean Abundance in the North Sea), was conducted in summer 1994 and designed to generate precise and unbiased abundance estimates. Thus the intensity of survey was high, and data collection and analysis methods allowed for the probability of detection of animals on the transect line being less than unity and, for shipboard surveys, also allowed for animal movement in response to the survey platform. 3. Shipboard transects covered 20 000 km in an area of 890 000 km2. Aerial transects covered 7000 km in an area of 150 000 km2. 4. Three species dominated the data. Harbour porpoise Phocoena phocoena were encountered throughout the survey area except in the Channel and the southern North Sea. Whitebeaked dolphin Lagenorhynchus albirostris and minke whale Balaenoptera acutorostrata were found mainly in the north-western North Sea. 5. Phocoena phocoena abundance for the entire survey area was estimated as 341 366 [coefficient of variation (CV) = 0.14; 95% confidence interval (CI) = 260 000-449 000]. The estimated number of B. acutorostrata was 8445 (CV = 0.24; 95% CI 5000-13 500). The estimate for L. albirostris based on confirmed sightings of this species was 7856 (CV = 0.30; 95% CI = 4000-13 000). When Atlantic whitesided dolphin Lagenorhynchus acutus and Lagenorhynchus spp. sightings were included, this estimate increased to 11 760 (CV = 0.26; 95% CI 5900-18 500). 6. Shortbeaked common dolphin Delphinus delphis were found almost exclusively in the Celtic Sea. Abundance was estimated as 75 450 (CV = 0.67; 95% CI = 23 000-149 000). 7. Current assessments and recommendations by international fora concerning the impact on P. phocoena of bycatch in gillnet fisheries in the North Sea and adjacent waters are based on these estimates.

Hypoxia in the Baltic Sea and Basin-Scale Changes in Phosphorus Biogeochemistry

Abstract: Deep-water oxygen concentrations in the Baltic Sea are influenced by eutrophication, but also by saltwater inflows from the North Sea. In the last two decades, only two major inflows have been recorded and the lack of major inflows is believed to have resulted in a long-term stagnation of the deepest bottom water. Analyzing data from 1970 to 2000 at the basin scale, we show that the estimated volume of water with oxygen, < 2m L L -1 , was actually at a minimum at the end of the longest so-called stagnation period on record. We also show that annual changes in dissolved inorganic phosphate water pools were positively correlated to the area of bottom covered by hypoxic water, but not to changes in total phosphorus load, thus addressing the legacy of eutrophication on a basinwide scale. The variations in phosphorus pools that have occurred during the past decades do not reflect any human action to reduce inputs. The long residence time and internally controlled variation of the large P pool in the Baltic Sea has important implications for management of both N and P inputs into this eutrophicated enclosed basin.

Modified phthalocyanines for efficient near-IR sensitization of nanostructured TiO(2) electrode.

Abstract: A zinc phthalocyanine with tyrosine substituents (ZnPcTyr), modified for efficient far-red/near-IR performance in dye-sensitized nanostructured TiO(2) solar cells, and its reference, glycine-substituted zinc phthalocyanine (ZnPcGly), were synthesized and characterized. The compounds were studied spectroscopically, electrochemically, and photoelectrochemically. Incorporating tyrosine groups into phthalocyanine makes the dye ethanol-soluble and reduces surface aggregation as a result of steric effects. The performance of a solar cell based on ZnPcTyr is much better than that based on ZnPcGly. Addition of 3alpha,7alpha-dihydroxy-5beta-cholic acid (cheno) and 4-tert-butylpyridine (TBP) to the dye solution when preparing a dye-sensitized TiO(2) electrode diminishes significantly the surface aggregation and, therefore, improves the performance of solar cells based on these phthalocyanines. The highest monochromatic incident photo-to-current conversion efficiency (IPCE) of approximately 24% at 690 nm and an overall conversion efficiency (eta) of 0.54% were achieved for a cell based on a ZnPcTyr-sensitized TiO(2) electrode. Addition of TBP in the electrolyte decreases the IPCE and eta considerably, although it increases the open-circuit photovoltage. Time-resolved transient absorption measurements of interfacial electron-transfer kinetics in a ZnPcTyr-sensitized nanostructured TiO(2) thin film show that electron injection from the excited state of the dye into the conduction band of TiO(2) is completed in approximately 500 fs and that more than half of the injected electrons recombines with the oxidized dye molecules in approximately 300 ps. In addition to surface aggregation, the very fast electron recombination is most likely responsible for the low performance of the solar cell based on ZnPcTyr.

A 7400-year tree-ring chronology in northern Swedish Lapland: natural climatic variability expressed on annual to millennial timescales

Abstract: Tree-ring widths from 880 living, dry dead, and subfossil northern Swedish pines (Pinus syl vestris L) have been assembled into a continuous and precisely dated chronology (the Tornetrask chronology) covering the period 5407 BC to ad 1997 Biological trends in the data were removed with autoregressive standardization (ARS) to emphasize year-to-year variability, and with regional curve stan dardization (RCS) to emphasize variability on timescales from decades to centuries The strong association with summer mean temperature (June–August) has enabled the production of a temperature reconstruction for the last 7400 years, providing information on natural summer-temperature variability on timescales from years to centuries Numerous cold episodes, comparable in severity and duration to the severe summers of the seventeenth century, are shown throughout the last seven millennia Particularly severe conditions suggested between 600 and 1 BC correspond to a known period of glacier expansion The relatively warm

Relationship Marketing in the New Economy

Abstract: This article aims to put relationship marketing in the context of the New Economy; it is a quest for valid and practical theory. It is preoccupied with the reigning marketing management paradigm and a shift to a relationship marketing paradigm. A systemic view, referred to as total relationship marketing, is presented together with the core values and beliefs of relationship marketing. The article concludes that relationship marketing is fundamentally different from traditional marketing management and that successful implementation requires new mindsets.

A Gondwanan origin of passerine birds supported by DNA sequences of the endemic New Zealand wrens

Abstract: Zoogeographic, palaeontological and biochemical data support a Southern Hemisphere origin for passerine birds, while accumulating molecular data suggest that most extant avian orders originated in the mid-Late Cretaceous. We obtained DNA sequence data from the nuclear c-myc and RAG-1 genes of the major passerine groups and here we demonstrate that the endemic New Zealand wrens (Acanthisittidae) are the sister taxon to all other extant passerines, supporting a Gondwanan origin and early radiation of passerines. We propose that (i) the acanthisittids were isolated when New Zealand separated from Gondwana (ca. 82-85 Myr ago), (ii) suboscines, in turn, were derived from an ancestral lineage that inhabited western Gondwana, and (iii) the ancestors of the oscines (songbirds) were subsequently isolated by the separation of Australia from Antarctica. The later spread of passerines into the Northern Hemisphere reflects the northward migration of these former Gondwanan elements.

Land-use history and fragmentation of traditionally managed grasslands in Scandinavia

Abstract: Plants associated with traditional agricultural landscapes in northern Europe and Scandinavia are subjected to drastic habitat fragmentation. In this paper we discuss species response to fragmentation, against a background of vegetation and land-use history. Recent evidence suggests that grassland-forest mosaics have been prevalent long before the onset of human agriculture. We suggest that the creation of infield meadows and outland grazing (during the Iron Age) increased the amount and spatial predictability of grasslands, resulting in plant communities with exceptionally high species densities. Thus, distribution of plant species in the present-day landscape reflects historical land-use. This holds also when traditional management has ceased, due to a slow response by many species to abandonment and fragmentation. The distribution patterns are thus not in equilibrium with the present habitat distribution. Fragmentation influences remaining semi-natural grasslands such that species density is l...

Prediction of MHC class I binding peptides, using SVMHC

Abstract: Background T-cells are key players in regulating a specific immune response. Activation of cytotoxic T-cells requires recognition of specific peptides bound to Major Histocompatibility Complex (MHC) class I molecules. MHC-peptide complexes are potential tools for diagnosis and treatment of pathogens and cancer, as well as for the development of peptide vaccines. Only one in 100 to 200 potential binders actually binds to a certain MHC molecule, therefore a good prediction method for MHC class I binding peptides can reduce the number of candidate binders that need to be synthesized and tested.