| 1. |
- Jaeger, Anna, et al.
(författare)
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Transformation of organic micropollutants along hyporheic flow in bedforms of river-simulating flumes
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Urban streams receive increasing loads of organic micropollutants from treated wastewaters. A comprehensive understanding of the in-stream fate of micropollutants is thus of high interest for water quality management. Bedforms induce pumping effects considerably contributing to whole stream hyporheic exchange and are hotspots of biogeochemical turnover processes. However, little is known about the transformation of micropollutants in such structures. In the present study, we set up recirculating flumes to examine the transformation of a set of micropollutants along single flowpaths in two triangular bedforms. We sampled porewater from four locations in the bedforms over 78 days and analysed the resulting concentration curves using the results of a hydrodynamic model in combination with a reactive transport model accounting for advection, dispersion, first-order removal and retardation. The four porewater sampling locations were positioned on individual flowpaths with median solute travel times ranging from 11.5 to 43.3 h as shown in a hydrodynamic model previously. Highest stability was estimated for hydrochlorothiazide on all flowpaths. Lowest detectable half-lives were estimated for sotalol (0.7 h) and sitagliptin (0.2 h) along the shortest flowpath. Also, venlafaxine, acesulfame, bezafibrate, irbesartan, valsartan, ibuprofen and naproxen displayed lower half-lives at shorter flowpaths in the first bedform. However, the behavior of many compounds in the second bedform deviated from expectations, where particularly transformation products, e.g. valsartan acid, showed high concentrations. Flowpath-specific behavior as observed for metformin or flume-specific behavior as observed for metoprolol acid, for instance, was attributed to potential small-scale or flume-scale heterogeneity of microbial community compositions, respectively. The results of the study indicate that the shallow hyporheic flow field and the small-scale heterogeneity of the microbial community are major controlling factors for the transformation of relevant micropollutants in river sediments.
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| 2. |
- Jaeger, Anna, et al.
(författare)
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Using recirculating flumes and a response surface model to investigate the role of hyporheic exchange and bacterial diversity on micropollutant half-lives
- 2019
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Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 21:12, s. 2093-2108
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Tidskriftsartikel (refereegranskat)abstract
- Enhancing the understanding of the fate of wastewater-derived organic micropollutants in rivers is crucial to improve risk assessment, regulatory decision making and river management. Hyporheic exchange and sediment bacterial diversity are two factors gaining increasing importance as drivers for micropollutant degradation, but are complex to study in field experiments and usually ignored in laboratory tests aimed to estimate environmental half-lives. Flume mesocosms are useful to investigate micropollutant degradation processes, bridging the gap between the field and batch experiments. However, few studies have used flumes in this context. We present a novel experimental setup using 20 recirculating flumes and a response surface model to study the influence of hyporheic exchange and sediment bacterial diversity on half-lives of the anti-epileptic drug carbamazepine (CBZ) and the artificial sweetener acesulfame (ACS). The effect of bedform-induced hyporheic exchange was tested by three treatment levels differing in number of bedforms (0, 3 and 6). Three levels of sediment bacterial diversity were obtained by diluting sediment from the River Erpe in Berlin, Germany, with sand (1 : 10, 1 : 1000 and 1 : 100 000). Our results show that ACS half-lives were significantly influenced by sediment dilution and number of bedforms. Half-lives of CBZ were higher than ACS, and were significantly affected only by the sediment dilution variable, and thus by bacterial diversity. Our results show that (1) the flume-setup is a useful tool to study the fate of micropollutants in rivers, and that (2) higher hyporheic exchange and bacterial diversity in the sediment can increase the degradation of micropollutants in rivers.
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| 3. |
- Lewandowski, Jörg, et al.
(författare)
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Is the Hyporheic Zone Relevant beyond the Scientific Community?
- 2019
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors.
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| 4. |
- Bach, Lennart T, et al.
(författare)
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Influence of Ocean Acidification on a Natural Winter-to-Summer Plankton Succession: First Insights from a Long-Term Mesocosm Study Draw Attention to Periods of Low Nutrient Concentrations
- 2016
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Every year, the oceans absorb about 30% of anthropogenic carbon dioxide (CO2) leading to a re-equilibration of the marine carbonate system and decreasing seawater pH. Today, there is increasing awareness that these changes-summarized by the term ocean acidification (OA)-could differentially affect the competitive ability of marine organisms, thereby provoking a restructuring of marine ecosystems and biogeochemical element cycles. In winter 2013, we deployed ten pelagic mesocosms in the Gullmar Fjord at the Swedish west coast in order to study the effect of OA on plankton ecology and biogeochemistry under close to natural conditions. Five of the ten mesocosms were left unperturbed and served as controls (similar to 380 mu atm pCO(2)), whereas the others were enriched with CO2-saturated water to simulate realistic end-of-the-century carbonate chemistry conditions (mu 760 mu atm pCO(2)). We ran the experiment for 113 days which allowed us to study the influence of high CO2 on an entire winter-to-summer plankton succession and to investigate the potential of some plankton organisms for evolutionary adaptation to OA in their natural environment. This paper is the first in a PLOS collection and provides a detailed overview on the experimental design, important events, and the key complexities of such a "long-term mesocosm" approach. Furthermore, we analyzed whether simulated end-of-the-century carbonate chemistry conditions could lead to a significant restructuring of the plankton community in the course of the succession. At the level of detail analyzed in this overview paper we found that CO2-induced differences in plankton community composition were non-detectable during most of the succession except for a period where a phytoplankton bloom was fueled by remineralized nutrients. These results indicate: (1) Long-term studies with pelagic ecosystems are necessary to uncover OA-sensitive stages of succession. (2) Plankton communities fueled by regenerated nutrients may be more responsive to changing carbonate chemistry than those having access to high inorganic nutrient concentrations and may deserve particular attention in future studies.
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| 5. |
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| 6. |
- Dolfini, Andrea, et al.
(författare)
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Prehistoric warfare and violence - quantitative and qualitative approaches
- 2018
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- This is the first book to explore prehistoric warfare and violence by integrating qualitative research methods with quantitative, scientific techniques of analysis such as paleopathology, morphometry, wear analysis, and experimental archaeology. It investigates early warfare and violence from the standpoint of four broad interdisciplinary themes: skeletal markers of violence and weapon training; conflict in prehistoric rock-art; the material culture of conflict; and intergroup violence in archaeological discourse. The book has a wide-ranging chronological and geographic scope, from early Neolithic to late Iron Age and from Western Europe to East Asia. It includes world-renowned sites and artefact collections such as the Tollense Valley Bronze Age battlefield (Germany), the UNESCO World Heritage Site at Tanum (Sweden), and the British Museum collection of bronze weaponry from the late Shang period (China). Original case studies are presented in each section by a diverse international authorship. The study of warfare and violence in prehistoric and pre-literate societies has been at the forefront of archaeological debate since the publication of Keeley’s provocative monograph ‘War Before Civilization’ (Oxford 1996). The problem has been approached from a number of standpoints including anthropological and behavioural studies of interpersonal violence, osteological examinations of sharp lesions and blunt-force traumas, wear analysis of ancient weaponry, and field experiments with replica weapons and armour. This research, however, is often confined within the boundaries of the various disciplines and specialist fields. In particular, a gap can often be detected between the research approaches grounded in the humanities and social sciences and those based on the archaeological sciences. The consequence is that, to this day, the subject is dominated by a number of undemonstrated assumptions regarding the nature of warfare, combat, and violence in non-literate societies. Moreover, important methodological questions remain unanswered: can we securely distinguish between violence-related and accidental trauma on skeletal remains? To what extent can wear analysis shed light on long-forgotten fighting styles? Can we design meaningful combat tests based on historic martial arts? And can the study of rock-art unlock the social realities of prehistoric warfare? By breaking the mould of entrenched subject boundaries, this edited volume promotes interdisciplinary debate in the study of prehistoric warfare and violence by presenting a number of innovative approaches that integrate qualitative and quantitative methods of research and analysis.
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| 7. |
- García-Montaner, Andrea, 1988-
(författare)
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Genome evolution of a bee-associated bacterium
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of large-scale comparative genomics allows us to explore the genetic diversity and mechanisms of evolution of related organisms. This thesis has focused on the application of such approaches to study Lactobacillus kunkeei, a bacterial inhabitant of the honeybee gut.We produced 102 novel complete genomes from L. kunkeei, which were used in four large comparative studies. In the first study, 41 bacterial strains were isolated from the crop of honeybees whose populations were geographically isolated. Their genome sequences revealed differences in gene contents, including the mobilome, which were mostly phylogroup-specific. However, differences in strain diversity and co-occurrence between both locations were observed. In the second study, we obtained 61 bacterial isolates from neighboring hives at different timepoints during the summer. We observed that strain diversity seemed hive-specific and relatively constant in time. Surprisingly, the observed mobilome also showed hive specificity and was maintained through the summer.The novel genome data were combined with previously published genomes, allowing us to perform deep comparative analyses on the evolution of the species using a total of 126 genomes. We determined that, despite the large number of sequenced genomes, L. kunkeei has an open pangenome. Besides, we evaluated the effects of recombination on the species core genome, and concluded that it mainly evolves through mutation events.In the last study we described the mechanisms of evolution of a cluster of 5 giant genes (about 90 kb long in total) that are unique to L. kunkeei and the closest sister species. Their patterns of evolution do not reflect those of the species core genome. We concluded that they originated by duplication events, and have diverged by accumulation of both mutations and recombination events. We predicted a potential interaction between the proteins encoded by two of them, and we hypothesized a role in host-specific interaction for another protein.In conclusion, these studies have provided novel and cohesive knowledge on the composition and dynamics of different populations of L. kunkeei, and may have contributed to better understand its ecological niche.
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| 8. |
- Grindegård, Linnéa, et al.
(författare)
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Association Between EEG Patterns and Serum Neurofilament Light After Cardiac Arrest: A Post Hoc Analysis of the TTM Trial.
- 2022
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Ingår i: Neurology. - 1526-632X .- 0028-3878. ; 98:24
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Tidskriftsartikel (refereegranskat)abstract
- Electroencephalography (EEG) is widely used for prediction of neurological outcome after cardiac arrest. To better understand the relationship between EEG and neuronal injury, we explore the association between EEG and neurofilament light (NFL) as a marker of neuroaxonal injury. We evaluate whether highly malignant EEG patterns are reflected by high NFL levels. Additionally, we explore the association of EEG backgrounds and EEG discharges with NFL.Post-hoc analysis of the Target Temperature Management after out-of-hospital cardiac arrest (TTM)-trial. Routine EEGs were prospectively performed after the temperature intervention ≥36 hours post-arrest. Patients who awoke or died prior to 36 hours post-arrest were excluded. EEG-experts blinded to clinical information classified EEG background, amount of discharges and highly malignant EEG patterns according to the standardized American Clinical Neurophysiology Society terminology. Prospectively collected serum samples were analyzed for NFL after trial completion. The highest available concentration at 48 or 72-hours post-arrest was used.262/939 patients with EEG and NFL data were included. Patients with highly malignant EEG patterns had 2.9 times higher NFL levels than patients with malignant patterns and NFL levels were 13 times higher in patients with malignant patterns than those with benign patterns (95% CI: 1.4-6.1 and 6.5-26.2 respectively, effect size 0.47, p<0.001). Both background and the amount of discharges were independently strongly associated with NFL levels (p<0.001). The EEG background had a stronger association with NFL levels than EEG discharges (R2=0.30 and R2=0.10, respectively). NFL levels in patients with a continuous background were lower than for any other background (95% CI for discontinuous, burst-suppression and suppression, respectively: 2.26-18.06, 3.91-41.71 and 5.74-41.74, effect size 0.30 and p<0.001 for all). NFL levels did not differ between suppression and burst-suppression. Superimposed discharges were only associated with higher NFL levels if the EEG background was continuous.Benign, malignant, and highly malignant EEG patterns reflect the extent of brain injury as measured by NFL in serum. The extent of brain injury is more strongly related to the EEG background than superimposed discharges. Combining EEG and NFL may be useful to better identify patients misclassified by single methods.clinicaltrials.gov, NCT01020916.
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| 9. |
- Iwaya, Leonardo H, et al.
(författare)
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Organisational Privacy Culture and Climate : A Scoping Review
- 2022
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 10, s. 73907-73930
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Forskningsöversikt (refereegranskat)abstract
- New regulations worldwide are increasingly pressing organisations to review how they collect and process personal data to ensure the protection of individual privacy rights. This organisational transformation involves implementing several privacy practices (e.g., privacy policies, governance frameworks, and privacy-by-design methods) across multiple departments. The literature points to a strong influence of the organisations’ culture and climate in implementing such privacy practices, depending on how leaders and employees perceive and address privacy concerns. However, this new hybrid topic referred to as Organisational Privacy Culture and Climate (OPCC), remains poorly demarcated and weakly defined. In this paper, we report a Scoping Review (ScR) on the topic of OPCC to systematically identify and map studies, contributing with a synthesis of the existing work, distinguishing core and adjacent publications, research gaps, and pathways of future research. This ScR includes 36 studies categorised according to their demographics, research types, contribution types, research designs, proposed definitions, and conceptualisations. Also, 18 studies categorised as primary research were critically appraised, assessing the studies’ methodological quality and credibility of the evidence. Although published research has significantly advanced the topic of OPCC, more research is still needed. Our findings show that the topic is still in its embryonic stage. The theory behind OPCC has not yet been fully articulated, even though some definitions have been independently proposed. Only one measuring instrument for privacy culture was identified, but it needs to be further developed in terms of identifying and analysing its factors, and evaluating its validity and reliability. Initiatives of future research in OPCC will require interdisciplinary research efforts and close cooperation with industry to further propose and rigorously evaluate instruments. Only then OPCC would be considered an evidence-based research topic that can be reliably used to evaluate, measure, and embed privacy in organisations.
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| 10. |
- Lindblad-Toh, Kerstin, et al.
(författare)
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Genome sequence, comparative analysis and haplotype structure of the domestic dog.
- 2005
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 438:7069, s. 803-19
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Tidskriftsartikel (refereegranskat)abstract
- Here we report a high-quality draft genome sequence of the domestic dog (Canis familiaris), together with a dense map of single nucleotide polymorphisms (SNPs) across breeds. The dog is of particular interest because it provides important evolutionary information and because existing breeds show great phenotypic diversity for morphological, physiological and behavioural traits. We use sequence comparison with the primate and rodent lineages to shed light on the structure and evolution of genomes and genes. Notably, the majority of the most highly conserved non-coding sequences in mammalian genomes are clustered near a small subset of genes with important roles in development. Analysis of SNPs reveals long-range haplotypes across the entire dog genome, and defines the nature of genetic diversity within and across breeds. The current SNP map now makes it possible for genome-wide association studies to identify genes responsible for diseases and traits, with important consequences for human and companion animal health.
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| 11. |
- Moseby-Knappe, Marion, et al.
(författare)
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Head computed tomography for prognostication of poor outcome in comatose patients after cardiac arrest and targeted temperature management
- 2017
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Ingår i: Resuscitation. - : Elsevier BV. - 1873-1570 .- 0300-9572. ; 119, s. 89-94
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: A multimodal approach to prognostication of outcome after cardiac arrest (CA) is recommended. Evidence for combinations of methods is low. In this post-hoc analysis we described findings on head computed tomography (CT) after CA. We also examined whether generalised oedema on CT alone or together with the biomarker Neuron-specific enolase (NSE) could predict poor outcome.METHODS: Patients participating in the Target Temperature Management after out-of-hospital-cardiac-arrest-trial underwent CT based on clinical indications. Findings were divided into pre-specified categories according to local radiologists descriptions. Generalised oedema alone and in combination with peak NSE at either 48h or 72h was correlated with poor outcome at 6 months follow-up using the Cerebral Performance Category (CPC 3-5).RESULTS: 356/939 (37.9%) of patients underwent head CT. Initial CT≤24h after CA was normal in 174/218 (79.8%), whilst generalised oedema was diagnosed in 21/218 (9.6%). Between days 1-7, generalised oedema was seen in 65/143 (45.5%), acute/subacute infarction in 27/143 (18.9%) and bleeding in 9/143 (6.3%). Overall, generalised oedema predicted poor outcome with 33.6% sensitivity (95%CI:28.1-39.5) and 98.4% specificity (95%CI:94.3-99.6), whilst peak NSE demonstrated sensitivities of 61.5-64.8% and specificity 95.7% (95%CI:89.5-98.4). The combination of peak NSE>38ng/l and generalised oedema on CT predicted poor outcome with 46.0% sensitivity (95%CI:36.5-55.8) with no false positives. NSE was significantly higher in patients with generalised oedema.CONCLUSION: In this study, generalised oedema was more common >24h≤7d after CA. The combination of CT and NSE improved sensitivity and specificity compared to CT alone, with no false positives in this limited population.
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| 12. |
- Peluso, Lorenzo, et al.
(författare)
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Neurological pupil index and its association with other prognostic tools after cardiac arrest : A post hoc analysis
- 2022
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572. ; 179, s. 259-266
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: We evaluated the concordance of the Neurological pupil Index (NPi) with other predictors of outcome after cardiac arrest (CA). Methods: Post hoc analysis of a prospective, international, multicenter study including adult CA patients. Predictors of unfavorable outcome (UO, Cerebral Performance Category of 3–5 at 3 months) included: a) worst NPi ≤ 2; b) presence of discontinuous encephalography (EEG) background; c) bilateral absence of N20 waves on somatosensory evoked potentials (N20ABS); d) peak neuron-specific enolase (NSE) blood levels > 60 mcg/L; e) myoclonus, which were all tested in a subset of patients who underwent complete multimodal assessment (MMM). Results: A total of 269/456 (59 %) patients had UO and 186 (41 %) underwent MMM. The presence of myoclonus was assessed in all patients, EEG in 358 (78 %), N20 in 186 (41 %) and NSE measurement in 228 (50 %). Patients with discontinuous EEG, N20ABS or high NSE had a higher proportion of worst NPi ≤ 2. The accuracy for NPi to predict a discontinuous EEG, N20ABS, high NSE and the presence of myoclonus was moderate. Concordance with NPi ≤ 2 was high for NSE, and moderate for discontinuous EEG and N20ABS. Also, the higher the number of concordant predictors of poor outcome, the lower the observed NPi. Conclusions: In this study, NPi ≤ 2 had moderate to high concordance with other unfavorable outcome prognosticators of hypoxic-ischemic brain injury. This indicates that NPi measurement could be considered as a valid tool for coma prognostication after cardiac arrest.
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| 13. |
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| 14. |
- Sampson, Joshua N., et al.
(författare)
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Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
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| 15. |
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| 16. |
- Sandroni, Claudio, et al.
(författare)
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Prognostication in comatose survivors of cardiac arrest: An advisory statement from the European Resuscitation Council and the European Society of Intensive Care Medicine
- 2014
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 40:12, s. 1816-1831
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Tidskriftsartikel (refereegranskat)abstract
- To review and update the evidence on predictors of poor outcome (death, persistent vegetative state or severe neurological disability) in adult comatose survivors of cardiac arrest, either treated or not treated with controlled temperature, to identify knowledge gaps and to suggest a reliable prognostication strategy. GRADE-based systematic review followed by expert consensus achieved using Web-based Delphi methodology, conference calls and face-to-face meetings. Predictors based on clinical examination, electrophysiology, biomarkers and imaging were included. Evidence from a total of 73 studies was reviewed. The quality of evidence was low or very low for almost all studies. In patients who are comatose with absent or extensor motor response at a parts per thousand yen72 h from arrest, either treated or not treated with controlled temperature, bilateral absence of either pupillary and corneal reflexes or N20 wave of short-latency somatosensory evoked potentials were identified as the most robust predictors. Early status myoclonus, elevated values of neuron-specific enolase at 48-72 h from arrest, unreactive malignant EEG patterns after rewarming, and presence of diffuse signs of postanoxic injury on either computed tomography or magnetic resonance imaging were identified as useful but less robust predictors. Prolonged observation and repeated assessments should be considered when results of initial assessment are inconclusive. Although no specific combination of predictors is sufficiently supported by available evidence, a multimodal prognostication approach is recommended in all patients.
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| 17. |
- Strömer, Hinrik, et al.
(författare)
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Growth hormone- and pressure overload-induced cardiac hypertrophy evoke different responses to ischemia-reperfusion and mechanical stretch.
- 2006
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Ingår i: Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society. - : Elsevier BV. - 1096-6374. ; 16:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare the molecular, histological, and functional characteristics of growth hormone (GH)- and pressure overload-induced cardiac hypertrophy, and their responses to ischemia-reperfusion and mechanical stretch. DESIGN: Four groups of male Wistar rats were studied: aortic banding (n=24, AB) or sham (n=24, controls) for 10 weeks, and GH treatment (n=24; 3.5mg/kg/day, GH) or placebo (n=24, controls) for 4 weeks. At 13 weeks, the rats were randomly subjected to: (i) assessment of basal left ventricular mRNA expression of sarcoplasmic reticulum calcium-ATPase (SERCA-2), phospholamban (PLB), and Na(+)-Ca(2+) exchanger (NCX) and collagen volume fraction (CVF) (Protocol A, 8 rats in each group); (ii) left ventricular no-flow ischemia with simultaneous evaluation of intracellular Ca(2+) handling and ATP, phosphocreatine (PCr) and inorganic phosphate (Pi) content (Protocol B, 12 rats in each group); or (iii) left ventricular mechanical stretch for 40 min with assessment of tumor necrosis-alpha (TNF-alpha) mRNA (Protocol C, 4 rats in each group). Protocol B and C were carried out in a Langendorff apparatus. RESULTS: In Protocol A, no difference was found as to myocardial mRNA content of Ca(2+) regulating proteins and CVF in GH animals vs controls. In contrast, in the AB group, myocardial mRNA expression of SERCA-2 and PLB was downregulated while that of NCX and CVF were increased vs. controls (p<0.05). In Protocol B, recovery of left ventricular function was significantly decreased in AB vs GH groups and controls and this was associated with 1.6-fold increase in intracellular Ca(2+) overload during reperfusion (p<0.05). Baseline ATP content was similar in the four study groups, whereas PCr and Pi was lower in AB vs GH rats and controls. However, the time courses of high-energy phosphate metabolic changes did not differ during ischemia and reperfusion in the four study groups. In Protocol C, no detectable TNF-alpha mRNA level was found in the left ventricular myocardium of GH treated rats and controls at baseline, while a modest expression was noted in AB animals. Mechanical stretch resulted in de novo myocardial TNF-alpha mRNA expression in GH group and controls, which was dramatically increased in AB animals ( approximately 5-fold above baseline, p<0.001). CONCLUSIONS: The data show that cardiac hypertrophy activated by short-term GH treatment confers cardioprotection compared with pressure overload with regard to molecular and histological characteristics, and responses to ischemia-reperfusion and mechanical stretch.
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| 18. |
- Taucher, Jan, et al.
(författare)
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Influence of ocean acidification and deep water upwelling on oligotrophic plankton communities in the subtropical North Atlantic : insights from an in situ mesocosm study
- 2017
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Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Oceanic uptake of anthropogenic carbon dioxide (CO2) causes pronounced shifts in marine carbonate chemistry and a decrease in seawater pH. Increasing evidence indicates that these changes—summarized by the term ocean acidification (OA)—can significantly affect marine food webs and biogeochemical cycles. However, current scientific knowledge is largely based on laboratory experiments with single species and artificial boundary conditions, whereas studies of natural plankton communities are still relatively rare. Moreover, the few existing community-level studies were mostly conducted in rather eutrophic environments, while less attention has been paid to oligotrophic systems such as the subtropical ocean gyres. Here we report from a recent in situ mesocosm experiment off the coast of Gran Canaria in the eastern subtropical North Atlantic, where we investigated the influence of OA on the ecology and biogeochemistry of plankton communities in oligotrophic waters under close-to-natural conditions. This paper is the first in this Research Topic of Frontiers in Marine Biogeochemistry and provides (1) a detailed overview of the experimental design and important events during our mesocosm campaign, and (2) first insights into the ecological responses of plankton communities to simulated OA over the course of the 62-day experiment. One particular scientific objective of our mesocosm experiment was to investigate how OA impacts might differ between oligotrophic conditions and phases of high biological productivity, which regularly occur in response to upwelling of nutrient-rich deep water in the study region. Therefore, we specifically developed a deep water collection system that allowed us to obtain ~85 m3 of seawater from ~650 m depth. Thereby, we replaced ~20% of each mesocosm's volume with deep water and successfully simulated a deep water upwelling event that induced a pronounced plankton bloom. Our study revealed significant effects of OA on the entire food web, leading to a restructuring of plankton communities that emerged during the oligotrophic phase, and was further amplified during the bloom that developed in response to deep water addition. Such CO2-related shifts in plankton community composition could have consequences for ecosystem productivity, biomass transfer to higher trophic levels, and biogeochemical element cycling of oligotrophic ocean regions.
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| 19. |
- Westhall, Erik, et al.
(författare)
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Electroencephalography (EEG) for neurological prognostication after cardiac arrest and targeted temperature management; rationale and study design
- 2014
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Ingår i: BMC Neurology. - : Springer Science and Business Media LLC. - 1471-2377. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Electroencephalography (EEG) is widely used to assess neurological prognosis in patients who are comatose after cardiac arrest, but its value is limited by varying definitions of pathological patterns and by inter-rater variability. The American Clinical Neurophysiology Society (ACNS) has recently proposed a standardized EEG-terminology for critical care to address these limitations. In the Target Temperature Management (TTM) trial, a large international trial on temperature management after cardiac arrest, EEG-examinations were part of the prospective study design. The main objective of this study is to evaluate EEG-data from the TTM-trial and to identify malignant EEG-patterns reliably predicting a poor neurological outcome. Methods/Design: In the TTM-trial, 399 post cardiac arrest patients who remained comatose after rewarming underwent a routine EEG. The presence of clinical seizures, use of sedatives and antiepileptic drugs during the EEG-registration were prospectively documented. After the end of the trial, the EEGs were retrieved to form a central EEG-database. The EEG-data will be analysed using the ACNS EEG terminology. We designed an electronic case record form (eCRF). Four EEG-specialists from different countries, blinded to patient outcome, will independently classify the EEGs and report through the eCRF. We will describe the prognostic values of pre-specified EEG patterns to predict poor as well as good outcome. We hypothesise three patterns to always be associated with a poor outcome (suppressed background without discharges, suppressed background with continuous periodic discharges and burst-suppression). Inter- and intra-rater variability and whether sedation or level of temperature affects the prognostic values will also be analyzed. Discussion: A well-defined terminology for interpreting post cardiac arrest EEGs is critical for the use of EEG as a prognostic tool. The results of this study may help to validate the ACNS terminology for assessing post cardiac arrest EEGs and identify patterns that could reliably predict outcome.
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| 20. |
- Westhall, Erik, et al.
(författare)
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Interrater agreement of EEG interpretation in comatose post cardiac arrest patients
- 2015
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Ingår i: Clinical Neurophysiology. - : Elsevier BV. - 1388-2457. ; 126:8, s. 171-171
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Konferensbidrag (refereegranskat)abstract
- Question: What is the interrater agreement of EEG interpretation in adult comatose post cardiac arrest patients using the American Clinical Neurophysiology Society (ACNS) standardized critical care EEG terminology? Methods: The EEG-data were obtained from patients included in the Target Temperature Management trial (TTM), an international, multicenter, clinical trial of temperature management in comatose cardiac arrest patients [N Engl J Med 2013]. In the TTM trial a routine EEG was performed in patients still comatose 12-36. h after rewarming.For this study, one EEG-specialist (IR) chose 20 EEGs, covering important aspects of the ACNS EEG terminology. Four EEG-specialists with different nationalities (Sweden: EW, Denmark: TWK, The Netherlands: AFvR and Switzerland: AOR) acquired the ACNS EEG terminology [J Clin Neurophys 2013;30:1-27] and studied a web-based training-module. The four EEG-specialists subsequently interpreted (blinded to patients' identity) the 20 EEGs, reporting the findings according to the ACNS EEG terminology. Percent agreement and Fleiss kappa values for every category in the terminology were calculated. Percent agreement was defined as the proportion of the 20 EEGs in which all interpreters reported identical findings. Results: There was 65% agreement on whether a rhythmic or periodic pattern was present or not (Kappa 0.44). If a rhythmic or periodic pattern was present there was 93% agreement on which type of pattern (periodic discharges, rhythmic delta activity, rhythmic spike-and-wave/polyspike-and-wave/sharp-and-slow-wave) (Kappa 0.65). Conclusions: Using the ACNS EEG terminology in adult comatose post cardiac arrest patients there was moderate agreement on the presence and type of periodic and rhythmic patterns.
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| 21. |
- Westhall, Erik, et al.
(författare)
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Interrater variability of EEG interpretation in comatose cardiac arrest patients.
- 2015
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Ingår i: Clinical Neurophysiology. - : Elsevier BV. - 1872-8952 .- 1388-2457. ; 126:12, s. 2397-2404
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Tidskriftsartikel (refereegranskat)abstract
- EEG is widely used to predict outcome in comatose cardiac arrest patients, but its value has been limited by lack of a uniform classification. We used the EEG terminology proposed by the American Clinical Neurophysiology Society (ACNS) to assess interrater variability in a cohort of cardiac arrest patients included in the Target Temperature Management trial. The main objective was to evaluate if malignant EEG-patterns could reliably be identified.
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| 22. |
- Westhall, Erik, et al.
(författare)
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Standardized EEG interpretation accurately predicts prognosis after cardiac arrest
- 2016
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Ingår i: Neurology. - 0028-3878. ; 86:16, s. 1482-1490
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To identify reliable predictors of outcome in comatose patients after cardiac arrest using a single routine EEG and standardized interpretation according to the terminology proposed by the American Clinical Neurophysiology Society. Methods: In this cohort study, 4 EEG specialists, blinded to outcome, evaluated prospectively recorded EEGs in the Target Temperature Management trial (TTM trial) that randomized patients to 33°C vs 36°C. Routine EEG was performed in patients still comatose after rewarming. EEGs were classified into highly malignant (suppression, suppression with periodic discharges, burst-suppression), malignant (periodic or rhythmic patterns, pathological or nonreactive background), and benign EEG (absence of malignant features). Poor outcome was defined as best Cerebral Performance Category score 3-5 until 180 days. Results: Eight TTM sites randomized 202 patients. EEGs were recorded in 103 patients at a median 77 hours after cardiac arrest; 37% had a highly malignant EEG and all had a poor outcome (specificity 100%, sensitivity 50%). Any malignant EEG feature had a low specificity to predict poor prognosis (48%) but if 2 malignant EEG features were present specificity increased to 96% (p <0.001). Specificity and sensitivity were not significantly affected by targeted temperature or sedation. A benign EEG was found in 1% of the patients with a poor outcome. Conclusions: Highly malignant EEG after rewarming reliably predicted poor outcome in half of patients without false predictions. An isolated finding of a single malignant feature did not predict poor outcome whereas a benign EEG was highly predictive of a good outcome.
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