| 1. |
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| 2. |
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| 3. |
- Adam, J, et al.
(author)
-
Measurement of pion, kaon and proton production in proton-proton collisions at [Formula: see text] TeV.
- 2015
-
In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 75:5
-
Journal article (peer-reviewed)abstract
- The measurement of primary [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] production at mid-rapidity ([Formula: see text] 0.5) in proton-proton collisions at [Formula: see text][Formula: see text] 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/[Formula: see text] for pions, from 0.2 up to 6 GeV/[Formula: see text] for kaons and from 0.3 up to 6 GeV/[Formula: see text] for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.
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| 4. |
- Abelev, B, et al.
(author)
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Directed Flow of Charged Particles at Midrapidity Relative to the Spectator Plane in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV.
- 2013
-
In: Physical Review Letters. - 1079-7114. ; 111:23
-
Journal article (peer-reviewed)abstract
- The directed flow of charged particles at midrapidity is measured in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV relative to the collision symmetry plane defined by the spectator nucleons. A negative slope of the rapidity-odd directed flow component with approximately 3 times smaller magnitude than found at the highest RHIC energy is observed. This suggests a smaller longitudinal tilt of the initial system and disfavors the strong fireball rotation predicted for the LHC energies. The rapidity-even directed flow component is measured for the first time with spectators and found to be independent of pseudorapidity with a sign change at transverse momenta p_{T} between 1.2 and 1.7 GeV/c. Combined with the observation of a vanishing rapidity-even p_{T} shift along the spectator deflection this is strong evidence for dipolelike initial density fluctuations in the overlap zone of the nuclei. Similar trends in the rapidity-even directed flow and the estimate from two-particle correlations at midrapidity, which is larger by about a factor of 40, indicate a weak correlation between fluctuating participant and spectator symmetry planes. These observations open new possibilities for investigation of the initial conditions in heavy-ion collisions with spectator nucleons.
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| 5. |
- Abelev, B, et al.
(author)
-
K_{S}^{0} and Λ Production in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV.
- 2013
-
In: Physical Review Letters. - 1079-7114. ; 111:22
-
Journal article (peer-reviewed)abstract
- The ALICE measurement of K_{S}^{0} and Λ production at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV is presented. The transverse momentum (p_{T}) spectra are shown for several collision centrality intervals and in the p_{T} range from 0.4 GeV/c (0.6 GeV/c for Λ) to 12 GeV/c. The p_{T} dependence of the Λ/K_{S}^{0} ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher p_{T} with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate p_{T} is not observed in pp interactions at sqrt[s]=0.9 TeV and at sqrt[s]=7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured p_{T} spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of p_{T}, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the p_{T} dependence of the Λ/K_{S}^{0} ratio.
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| 6. |
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| 7. |
- Sachdev, P. S., et al.
(author)
-
STROKOG (stroke and cognition consortium): An international consortium to examine the epidemiology, diagnosis, and treatment of neurocognitive disorders in relation to cerebrovascular disease
- 2017
-
In: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 7, s. 11-23
-
Journal article (peer-reviewed)abstract
- Introduction The Stroke and Cognition consortium (STROKOG) aims to facilitate a better understanding of the determinants of vascular contributions to cognitive disorders and help improve the diagnosis and treatment of vascular cognitive disorders (VCD). Methods Longitudinal studies with ≥75 participants who had suffered or were at risk of stroke or TIA and which evaluated cognitive function were invited to join STROKOG. The consortium will facilitate projects investigating rates and patterns of cognitive decline, risk factors for VCD, and biomarkers of vascular dementia. Results Currently, STROKOG includes 25 (21 published) studies, with 12,092 participants from five continents. The duration of follow-up ranges from 3months to 21years. Discussion Although data harmonization will be a key challenge, STROKOG is in a unique position to reuse and combine international cohort data and fully explore patient level characteristics and outcomes. STROKOG could potentially transform our understanding of VCD and have a worldwide impact on promoting better vascular cognitive outcomes. © 2016 The Authors
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| 8. |
- Böhm, M., et al.
(author)
-
The conservation status of the world’s freshwater molluscs
- 2021
-
In: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 848, s. 3231-3254
-
Journal article (peer-reviewed)abstract
- With the biodiversity crisis continuing unchecked, we need to establish levels and drivers of extinction risk, and reassessments over time, to effectively allocate conservation resources and track progress towards global conservation targets. Given that threat appears particularly high in freshwaters, we assessed the extinction risk of 1428 randomly selected freshwater molluscs using the IUCN Red List Categories and Criteria, as part of the Sampled Red List Index project. We show that close to one-third of species in our sample are estimated to be threatened with extinction, with highest levels of threat in the Nearctic, Palearctic and Australasia and among gastropods. Threat levels were higher in lotic than lentic systems. Pollution (chemical and physical) and the modification of natural systems (e.g. through damming and water abstraction) were the most frequently reported threats to freshwater molluscs, with some regional variation. Given that we found little spatial congruence between species richness patterns of freshwater molluscs and other freshwater taxa, apart from crayfish, new additional conservation priority areas emerged from our study. We discuss the implications of our findings for freshwater mollusc conservation, the adequacy of a sampled approach and important next steps to estimate trends in freshwater mollusc extinction risk over time. © 2020, Springer Nature Switzerland AG.
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| 9. |
- König, Alexandra, et al.
(author)
-
Screening over Speech in Unselected Populations for Clinical Trials in AD (PROSPECT-AD) : Study Design and Protocol
- 2023
-
In: Journal of Prevention of Alzheimer's Disease. - : SERDI. - 2274-5807. ; 10, s. 314-321
-
Journal article (peer-reviewed)abstract
- Background: Speech impairments are an early feature of Alzheimer’s disease (AD) and consequently, analysing speech performance is a promising new digital biomarker for AD screening. Future clinical AD trials on disease modifying drugs will require a shift to very early identification of individuals at risk of dementia. Hence, digital markers of language and speech may offer a method for screening of at-risk populations that are at the earliest stages of AD, eventually in combination with advanced machine learning. To this end, we developed a screening battery consisting of speech-based neurocognitive tests. The automated test performs a remote primary screening using a simple telephone. Objectives: PROSPECT-AD aims to validate speech biomarkers for identification of individuals with early signs of AD and monitor their longitudinal course through access to well-phenotyped cohorts. Design: PROSPECT-AD leverages ongoing cohorts such as EPAD (UK), DESCRIBE and DELCODE (Germany), and BioFINDER Primary Care (Sweden) and Beta-AARC (Spain) by adding a collection of speech data over the telephone to existing longitudinal follow-ups. Participants at risk of dementia are recruited from existing parent cohorts across Europe to form an AD ‘probability-spectrum’, i.e., individuals with a low risk to high risk of developing AD dementia. The characterization of cognition, biomarker and risk factor (genetic and environmental) status of each research participants over time combined with audio recordings of speech samples will provide a well-phenotyped population for comparing novel speech markers with current gold standard biomarkers and cognitive scores. Participants: N= 1000 participants aged 50 or older will be included in total, with a clinical dementia rating scale (CDR) score of 0 or 0.5. The study protocol is planned to run according to sites between 12 and 18 months. Measurements: The speech protocol includes the following neurocognitive tests which will be administered remotely: Word List [Memory Function], Verbal Fluency [Executive Functions] and spontaneous free speech [Psychological and/ or behavioral symptoms]. Speech features on the linguistic and paralinguistic level will be extracted from the recordings and compared to data from CSF and blood biomarkers, neuroimaging, neuropsychological evaluations, genetic profiles, and family history. Primary candidate marker from speech will be a combination of most significant features in comparison to biomarkers as reference measure. Machine learning and computational techniques will be employed to identify the most significant speech biomarkers that could represent an early indicator of AD pathology. Furthermore, based on the analysis of speech performances, models will be trained to predict cognitive decline and disease progression across the AD continuum. Conclusion: The outcome of PROSPECT-AD may support AD drug development research as well as primary or tertiary prevention of dementia by providing a validated tool using a remote approach for identifying individuals at risk of dementia and monitoring individuals over time, either in a screening context or in clinical trials.
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| 10. |
- Deans, Andrew R, et al.
(author)
-
Finding Our Way through Phenotypes.
- 2015
-
In: PLoS Biology. - : Public Library of Science (PLoS). - 1545-7885. ; 13:1
-
Journal article (peer-reviewed)abstract
- Despite a large and multifaceted effort to understand the vast landscape of phenotypic data, their current form inhibits productive data analysis. The lack of a community-wide, consensus-based, human- and machine-interpretable language for describing phenotypes and their genomic and environmental contexts is perhaps the most pressing scientific bottleneck to integration across many key fields in biology, including genomics, systems biology, development, medicine, evolution, ecology, and systematics. Here we survey the current phenomics landscape, including data resources and handling, and the progress that has been made to accurately capture relevant data descriptions for phenotypes. We present an example of the kind of integration across domains that computable phenotypes would enable, and we call upon the broader biology community, publishers, and relevant funding agencies to support efforts to surmount today's data barriers and facilitate analytical reproducibility.
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| 11. |
- Jansen, Willemijn J, et al.
(author)
-
Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia.
- 2018
-
In: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 75:1, s. 84-95
-
Journal article (peer-reviewed)abstract
- Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P=.16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P<.001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P<.001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years.Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
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| 12. |
- Jansen, Willemijn J, et al.
(author)
-
Prevalence of cerebral amyloid pathology in persons without dementia: a meta-analysis.
- 2015
-
In: JAMA. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 313:19, s. 1924-38
-
Journal article (peer-reviewed)abstract
- Cerebral amyloid-β aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies.
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| 13. |
- Moroder, M., et al.
(author)
-
Stable bipolarons in open quantum systems
- 2023
-
In: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 107:21
-
Journal article (peer-reviewed)abstract
- Recent advances in numerical methods significantly pushed forward the understanding of electrons coupled to quantized lattice vibrations. At this stage, it becomes increasingly important to also account for the effects of physically inevitable environments. Here, we combine state-of-the-art tensor-network and quantum trajectories methods in order to study the impact of dissipation on realistic condensed matter models including highly excited phononic modes. In particular, we study the transport properties of the Hubbard-Holstein Hamiltonian that models a large class of materials characterized by strong electron-phonon coupling, in contact with a dissipative environment. We combine the non-Markovian hierarchy of pure states method and the Markovian quantum jumps method with the newly introduced projected purified density-matrix renormalization group, creating powerful tensor-network methods for dissipative quantum many-body systems. Investigating their numerical properties, we find a significant speedup up to a factor approximate to 30 compared to conventional tensor-network techniques. We apply these methods to study dissipative quenches, aiming for an in-depth understanding of the formation, stability, and quasiparticle properties of bipolarons. Surprisingly, our results show that in the metallic phase dissipation localizes the bipolarons, which is reminiscent of an indirect quantum Zeno effect. However, the bipolaronic binding energy remains mainly unaffected, even in the presence of strong dissipation, exhibiting remarkable bipolaron stability. These findings shed light on the problem of designing real materials exhibiting phonon-mediated high-TC superconductivity.
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| 14. |
- Rosolymou, E., et al.
(author)
-
Electrodeposition of photocatalytic sn-ni matrix composite coatings embedded with doped TiO2 particles
- 2020
-
In: Coatings. - : MDPI. - 2079-6412. ; 10:8
-
Journal article (peer-reviewed)abstract
- Direct current electrodeposited Sn-Ni/TiO2 nanostructured coatings were produced by embedding two different doped types of TiO2 particles within the alloy matrix, a commercially available doped carbon-based and doped N, S-TiO2 particles. The structural characteristics of the composite coatings have been correlated with the effect of loading, type of particles in the electrolytic bath, and the applied current density. Regardless of the type of doped particles TiO2, increasing values of applied current density resulted in a reduction of the co-deposition percentage of TiO2 particles and an increase of Tin content into the alloy matrix. The application of low current density values accompanied by a high load of particles in the bath led to the highest codeposition percentage (~3.25 wt. %) achieved in the case of embedding N, S-TiO2 particles. X-ray diffraction data demonstrated that in composite coatings the incorporation of the different types of TiO2 particles in the alloy metal matrix modified significantly the nano-crystalline structure in comparison with the pure coatings. The best photocatalytic behavior under visible irradiation was revealed for the composite coatings with the highest co-deposition percentage of doped N, S-TiO2 particles, that also exhibited enhanced wear resistance and slightly reduced microhardness compared to pure ones.
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| 15. |
- Cascone, Claudia, et al.
(author)
-
AbspectroscoPY, a Python toolbox for absorbance-based sensor data in water quality monitoring
- 2022
-
In: Environmental Science: Water Research & Technology. - 2053-1419. ; 8:4, s. 836-848
-
Journal article (peer-reviewed)abstract
- The long-term trend of increasing natural organic matter (NOM) in boreal and north European surface waters represents an economic and environmental challenge for drinking water treatment plants (DWTPs). High-frequency measurements from absorbance-based online spectrophotometers are often used in modern DWTPs to measure the chromophoric fraction of dissolved organic matter (CDOM) over time. These data contain valuable information that can be used to optimise NOM removal at various stages of treatment and/or diagnose the causes of underperformance at the DWTP. However, automated monitoring systems generate large datasets that need careful preprocessing, followed by variable selection and signal processing before interpretation. In this work we introduce AbspectroscoPY (“Absorbance spectroscopic analysis inPython”), a Python toolbox for processing time-series datasets collected by in situ spectrophotometers. The toolbox addresses some of the main challenges in data preprocessing by handling duplicates, systematic time shifts, baseline corrections and outliers. It contains automated functions to compute a range of spectral metrics for the time-series data, including absorbance ratios, exponential fits, slope ratios and spectral slope curves. To demonstrate its utility, AbspectroscoPY was applied to 15-month datasets from three onlinespectrophotometers in a drinking water treatment plant. Despite only small variations in surface water quality over the time period, variability in the spectrophotometric profiles of treated water could be identified, quantified and related to lake turnover or operational changes in the DWTP. This toolboxrepresents a step toward automated early warning systems for detecting and responding to potential threats to treatment performance caused by rapid changes in incoming water quality.
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| 16. |
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| 17. |
- Köhler, S, et al.
(author)
-
Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden
- 2002
-
In: Water Research, Volume. ; 36:18, s. 4487-96
-
Journal article (peer-reviewed)abstract
- The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mgL-1 TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.
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| 18. |
- Köhler, Thomas, et al.
(author)
-
Formation of spatial patterns by spin-selective excitations of interacting fermions
- 2020
-
In: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 102:23
-
Journal article (peer-reviewed)abstract
- We describe the formation of charge- and spin-density patterns induced by spin-selective photoexcitations of interacting fermionic systems in the presence of a microstructure. As an example, we consider a one-dimensional Hubbard-like system with a periodic magnetic microstructure, which has a uniform charge distribution in its ground state, and in which a long-lived charge-density pattern is induced by the spin-selective photoexcitation. Using tensor-network methods, we study the full quantum dynamics in the presence of electron-electron interactions and identify doublons as the main decay channel for the induced charge pattern. Our setup is compared to the optically induced spin transfer (OISTR) mechanism, in which ultrafast optically induced spin transfer in Heusler and magnetic compounds is associated to the difference of the local density of states of the different elements in the alloys. We find that applying a spin-selective excitation there induces spatially periodic patterns in local observables. Implications for pump-probe experiments on correlated materials and experiments with ultracold gases on optical lattices are discussed.
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| 19. |
- Köhler, Th., et al.
(author)
-
Precision measurement of strong interaction isotope effects in antiprotonic 16O, 17O, and 18O atoms
- 1986
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 176:3-4, s. 327-333
-
Journal article (peer-reviewed)abstract
- The strong-interaction effects in antiprotonic 16O, 17O, and 18O atoms were measured at the CERN antiproton facility, LEAR. The shifts ε{lunate} and the widths Γ of the 3d level were determined to be -112±20 eV (16O), -140±46 eV (17O), -195±20 eV (18O), and 495±45 eV (16O), 540±150 (17O), 640±40 eV (18O), respectively. © 1986.
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| 20. |
- Peters, Ruth, et al.
(author)
-
An investigation of antihypertensive class, dementia, and cognitive decline: A meta-analysis.
- 2020
-
In: Neurology. - 1526-632X. ; 94:3
-
Journal article (peer-reviewed)abstract
- High blood pressure is one of the main modifiable risk factors for dementia. However, there is conflicting evidence regarding the best antihypertensive class for optimizing cognition. Our objective was to determine whether any particular antihypertensive class was associated with a reduced risk of cognitive decline or dementia using comprehensive meta-analysis including reanalysis of original participant data.To identify suitable studies, MEDLINE, Embase, and PsycINFO and preexisting study consortia were searched from inception to December 2017. Authors of prospective longitudinal human studies or trials of antihypertensives were contacted for data sharing and collaboration. Outcome measures were incident dementia or incident cognitive decline (classified using the reliable change index method). Data were separated into mid and late-life (>65 years) and each antihypertensive class was compared to no treatment and to treatment with other antihypertensives. Meta-analysis was used to synthesize data.Over 50,000 participants from 27 studies were included. Among those aged >65 years, with the exception of diuretics, we found no relationship by class with incident cognitive decline or dementia. Diuretic use was suggestive of benefit in some analyses but results were not consistent across follow-up time, comparator group, and outcome. Limited data precluded meaningful analyses in those ≤65 years of age.Our findings, drawn from the current evidence base, support clinical freedom in the selection of antihypertensive regimens to achieve blood pressure goals.The review was registered with the international prospective register of systematic reviews (PROSPERO), registration number CRD42016045454.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
- Bishop, K, et al.
(author)
-
Testing the steady-state water chemistry model predictions of pre-industrial lake pH with paleolimnological data from northern Sweden.
- 2008
-
In: Sci Total Environ. - : Elsevier BV. - 0048-9697. ; 407:1, s. 723-9
-
Journal article (peer-reviewed)abstract
- Criteria are needed for distinguishing naturally acid water from that acidified by air pollution, especially in the organic-rich waters of northern Sweden. The Steady-State Water Chemistry Model (SSWC) was augmented to include organic acidity so that it could predict pre-industrial pH in organic-rich waters. The resulting model predictions of preindustrial ANC and pH were then tested against diatom predictions of pre-industrial pH and alkalinity in 58 lakes from N. Sweden (after alkalinity was converted to ANC using the CBALK method). The SSWC Model's predictions of pre-industrial lake pH in N. Sweden did not correspond well with the diatom predictions, even when accounting for the uncertainty in the diatom model. This was due to the SSWC's sensitivity to short-term fluctuations in contemporary water chemistry. Thus the SSWC Model is not suitable for judging the acidification of individual lakes in areas such as northern Sweden where the degree of chronic acidification is small, or without a good average value of contemporary water chemistry. These results should be considered when assessing the accuracy of critical loads calculated using SSWC.
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| 28. |
- Bollmark, Gunnar, et al.
(author)
-
Solving 2D and 3D lattice models of correlated fermions : combining matrix product states with mean-field theory
- 2023
-
In: Physical Review X. - : American Physical Society. - 2160-3308. ; 13:1
-
Journal article (peer-reviewed)abstract
- Correlated electron states are at the root of many important phenomena including unconventional superconductivity (USC), where electron pairing arises from repulsive interactions. Computing the properties of correlated electrons, such as the critical temperature Tc for the onset of USC, efficiently and reliably from the microscopic physics with quantitative methods remains a major challenge for almost all models and materials. In this theoretical work, we combine matrix product states (MPS) with static mean field (MF) to provide a solution to this challenge for quasi-one-dimensional (Q1D) systems: two- and three-dimensional materials comprised of weakly coupled correlated 1D fermions. This MPS+MF framework for the ground state and thermal equilibrium properties of Q1D fermions is developed and validated for attractive Hubbard systems first, and further enhanced via analytical field theory. We then deploy it to compute Tc for superconductivity in 3D arrays of weakly coupled, doped, and repulsive Hubbard ladders. The MPS+MF framework thus enables the quantitative study of USC and high-Tc superconductivity—and potentially many more correlated phases—in fermionic Q1D systems based directly on their microscopic parameters, in ways inaccessible to previous methods. This approach further allows one to treat competing macroscopic orders, such as superconducting and insulating ones, on an equal footing. Benchmarks of the framework using auxiliary-field quantum Monte Carlo techniques show that the overestimation of, e.g., Tc due to its mean-field component, is near constant in microscopic parameters. These features of the MPS+MF approach to correlated fermions open up the possibility of designing deliberately optimized Q1D superconductors, from experiments in ultracold gases to synthesizing new materials.
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| 29. |
- Cascone, C., et al.
(author)
-
AbspectroscoPY, a Python toolbox for absorbance-based sensor data in water quality monitoring
- 2022
-
In: Environmental Science. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 8:4, s. 836-848
-
Journal article (peer-reviewed)abstract
- The long-term trend of increasing natural organic matter (NOM) in boreal and north European surface waters represents an economic and environmental challenge for drinking water treatment plants (DWTPs). High-frequency measurements from absorbance-based online spectrophotometers are often used in modern DWTPs to measure the chromophoric fraction of dissolved organic matter (CDOM) over time. These data contain valuable information that can be used to optimise NOM removal at various stages of treatment and/or diagnose the causes of underperformance at the DWTP. However, automated monitoring systems generate large datasets that need careful preprocessing, followed by variable selection and signal processing before interpretation. In this work we introduce AbspectroscoPY (“Absorbance spectroscopic analysis in Python”), a Python toolbox for processing time-series datasets collected by in situ spectrophotometers. The toolbox addresses some of the main challenges in data preprocessing by handling duplicates, systematic time shifts, baseline corrections and outliers. It contains automated functions to compute a range of spectral metrics for the time-series data, including absorbance ratios, exponential fits, slope ratios and spectral slope curves. To demonstrate its utility, AbspectroscoPY was applied to 15-month datasets from three online spectrophotometers in a drinking water treatment plant. Despite only small variations in surface water quality over the time period, variability in the spectrophotometric profiles of treated water could be identified, quantified and related to lake turnover or operational changes in the DWTP. This toolbox represents a step toward automated early warning systems for detecting and responding to potential threats to treatment performance caused by rapid changes in incoming water quality.
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| 30. |
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| 31. |
- Denoyes-Rothan, B, et al.
(author)
-
QTL analysis for resistances to Colletotrichum acutatum and Phytophthora cactorum in octoploid strawberry (Fragaria x ananassa)
- 2004
-
In: Proceedings of the XIth Eucarpia Symposium on Fruit Breeding and Genetics, Vols 1 and 2. - : INTERNATIONAL SOCIETY HORTICULTURAL SCIENCE. ; , s. 147-151
-
Conference paper (peer-reviewed)abstract
- Colletotrichum acutatum and Phytophthora cactorum are two of the most important pathogens of strawberry in Europe, and particularly in France. The characterization of quantitative trait loci (QTL) controlling resistances to these two pathogens would allow a better knowledge of the genetic architecture of these resistances in order to develop durable resistance. A pseudo-testcross strawberry population derived from the cross between Capitola and CF1116 was used for detecting QTLs associated with C. acutatum and P cactorum resistances. One hundred and eighty five individuals were inoculated with C. acutatum by dipping cold stored plants in a conidial suspension adjusted to 2.10(6) conidia per ml. They were also inoculated separately with P cactorum by inserting an agar disk containing mycelium into the crown. Each inoculation was conducted twice. Putative QTLs for resistance to C acutatum and P cactorum were identified by Interval Mapping (Mapmaker-QTL) using a LOD threshold of 2.
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| 32. |
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| 33. |
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| 34. |
- Erlandsson, M., et al.
(author)
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Spatial and temporal variations of base cation release from chemical weathering on a hillslope scale
- 2016
-
In: Chemical Geology. - : Elsevier BV. - 0009-2541 .- 1872-6836. ; 441, s. 1-13
-
Journal article (peer-reviewed)abstract
- Cation release rates to catchment runoff from chemical weathering were assessed using an integrated catchment model that included the soil's unsaturated, saturated and riparian zones. In-situ mineral dissolution rates were calculated in these zones as a function of pH, aluminum and dissolved organic carbon (DOC) concentrations along a hillslope in Northern Sweden where soil water was monitored over nine years. Three independent sets of mineral dissolution equations of varying complexity were used: PROFILE, Transition-State Theory (TST), and the Palandri & Kharaka database. Normalization of the rate-coefficients was necessary to compare the equations, as published rate-coefficients gave base cation release rates differing by several orders of magnitude. After normalizing the TST- and Palandri & Kharaka-rate coefficients to match the base cation release rates calculated from the PROFILE-equations, calculated Ca2 + and Mg2 + release rates are consistent with mass balance calculations, whereas those of Na+ and K+ are overestimated. Our calculations further indicate that a significant proportion of base cations are released from the organic soils in the near-stream zone, in part due to its finer texture. Of the three sets of rate equations, the base cation release rates calculated from the normalized TST-equations were more variable than those calculated using the other two sets of equations, both spatially and temporally, due to its higher sensitivity to pH. In contrast, the normalized Palandri & Kharaka-equations were more sensitive to variations in soil temperature.
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| 35. |
- Haas, Jan, et al.
(author)
-
Atlas of the clinical genetics of human dilated cardiomyopathy
- 2015
-
In: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 36:18, s. 1123-U43
-
Journal article (peer-reviewed)abstract
- Aim: We were able to show that targeted Next-Generation Sequencing is well suited to be applied in clinical routine diagnostics, substantiating the ongoing paradigm shift from low- to high-throughput genomics in medicine. By means of our atlas of the genetics of human DCM, we aspire to soon be able to apply our findings to the individual patient with cardiomyopathy in daily clinical practice. Numerous genes are known to cause dilated cardiomyopathy (DCM). However, until now technological limitations have hindered elucidation of the contribution of all clinically relevant disease genes to DCM phenotypes in larger cohorts. We now utilized next-generation sequencing to overcome these limitations and screened all DCM disease genes in a large cohort. Methods and results: In this multi-centre, multi-national study, we have enrolled 639 patients with sporadic or familial DCM. To all samples, we applied a standardized protocol for ultra-high coverage next-generation sequencing of 84 genes, leading to 99.1% coverage of the target region with at least 50-fold and a mean read depth of 2415. In this well characterized cohort, we find the highest number of known cardiomyopathy mutations in plakophilin-2, myosin-binding protein C-3, and desmoplakin. When we include yet unknown but predicted disease variants, we find titin, plakophilin-2, myosin-binding protein-C 3, desmoplakin, ryanodine receptor 2, desmocollin-2, desmoglein-2, and SCN5A variants among the most commonly mutated genes. The overlap between DCM, hypertrophic cardiomyopathy (HCM), and channelopathy causing mutations is considerably high. Of note, we find that >38% of patients have compound or combined mutations and 12.8% have three or even more mutations. When comparing patients recruited in the eight participating European countries we find remarkably little differences in mutation frequencies and affected genes. Conclusion: This is to our knowledge, the first study that comprehensively investigated the genetics of DCM in a large-scale cohort and across a broad gene panel of the known DCM genes. Our results underline the high analytical quality and feasibility of Next-Generation Sequencing in clinical genetic diagnostics and provide a sound database of the genetic causes of DCM.
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| 36. |
- Hilt, Sabine, et al.
(author)
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Response of submerged macrophyte communities to external and internal restoration measures in north temperate shallow lakes
- 2018
-
In: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 9
-
Journal article (peer-reviewed)abstract
- Submerged macrophytes play a key role in north temperate shallow lakes by stabilizing clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analyzed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterized by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterized by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallowareas, germinate early in spring, have energy-rich vegetative propagules facilitating rapid initial growth and that can complete their life cycle by early summer. Later in the growing season these plants are, according to our simulations, outcompeted by periphyton, leading to late-summer phytoplankton blooms. Internal lake restoration measures often coincide with a rapid but transient colonization by hornworts, waterweeds or charophytes. Stable clear-water conditions and a diverse macrophyte flora only occurred decades after external nutrient load reduction or when measures were combined.
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| 37. |
- Köhler, Christian, et al.
(author)
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Dynamic allosteric communication pathway directing differential activation of the glucocorticoid receptor
- 2020
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In: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:29
-
Journal article (peer-reviewed)abstract
- Allosteric communication within proteins is a hallmark of biochemical signaling, but the dynamic transmission pathways remain poorly characterized. We combined NMR spectroscopy and surface plasmon resonance to reveal these pathways and quantify their energetics in the glucocorticoid receptor, a transcriptional regulator controlling development, metabolism, and immune response. Our results delineate a dynamic communication network of residues linking the ligand-binding pocket to the activation function-2 interface, where helix 12, a switch for transcriptional activation, exhibits ligand- and coregulator-dependent dynamics coupled to graded activation. The allosteric free energy responds to variations in ligand structure: subtle changes gradually tune allostery while preserving the transmission pathway, whereas substitution of the entire pharmacophore leads to divergent allosteric control by apparently rewiring the communication network. Our results provide key insights that should aid in the design of mechanistically differentiated ligands.
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| 38. |
- Köhler, Elof, 1980, et al.
(author)
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Fabrication of High Temperature Thermoelectric Energy Harvesters for Wireless Sensors
- 2013
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 476:1, s. Art. no. 012036-
-
Conference paper (peer-reviewed)abstract
- Implementing energy harvesters and wireless sensors in jet engines could simplify development and decrease costs. A thermoelectric energy harvester could be placed in the cooling channels where the temperature is between 500–900°C. This paper covers the synthesis of suitable materials and the design and fabrication of a thermoelectric module. The material choices and other design variables were done from an analytic model by numerical analysis. The module was optimized for 600–800°C with the materials Ba8Ga16Ge30 and La-doped Yb14MnSb11, both having the highest measured zT value in this region. The design goal was to be able to maintain a temperature gradient of at least 200°C with high power output. The La-doped Yb14MnSb11 was synthesized and its structure confirmed by x-ray diffraction. Measurement of properties of this material was not possible due to insufficient size of the crystals. Ba8Ga16Ge30 was synthesized and resulted in an approximated zT value of 0.83 at 700°C. Calculations based on a module with 17 couples gave a power output of 1100mW/g or 600mW/cm2 with a temperature gradient of 200K.
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| 39. |
- Köhler, Elof, 1980, et al.
(author)
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High temperature energy harvester for wireless sensors
- 2014
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In: Smart Materials and Structures. - : IOP Publishing. - 0964-1726 .- 1361-665X. ; 23:9, s. Art. no. 095042-
-
Journal article (peer-reviewed)abstract
- Implementing energy harvesters and wireless sensors in jet engines will simplify development and decrease costs by reducing the need for cables. Such a device could include a small thermoelectric generator placed in the cooling channels of the jet engine where the temperature is between 500-900 degrees C. This paper covers the synthesis of suitable thermoelectric materials, design of module and proof of concept tests of a thermoelectric module. The materials and other design variables were chosen based on an analytic model and numerical analysis. The module was optimized for 600-800 degrees C with the thermoelectric materials n-type Ba8Ga16Ge30 and p-type La-doped Yb14MnSb11, both with among the highest reported figure-of-merit values, zT, for bulk materials in this region. The materials were synthesized and their structures confirmed by x-ray diffraction. Proof of concept modules containing only two thermoelectric legs were built and tested at high temperatures and under high temperature gradients. The modules were designed to survive an ambient temperature gradient of up to 200 degrees C. The first measurements at low temperature showed that the thermoelectric legs could withstand a temperature gradient of 123 degrees C and still be functional. The high temperature measurement with 800 degrees C on the hot side showed that the module remained functional at this temperature.
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| 40. |
- Köhler, Elof, 1980, et al.
(author)
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Proof of concept thermoelectric energy harvester powering wireless sensor on gas turbine
- 2016
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In: EVI-GTI and PIWG Joint Conference on Gas Turbine Instrumentation, Berlin, Germany, 27-29 September 2016. - : Institution of Engineering and Technology. ; 2016:CP693
-
Conference paper (peer-reviewed)abstract
- The thermoelectric energy harvester went from simulations to synthesis of materials and fabrication of test prototypes. We also made measurements on a 1-couple module which did show that the technology is feasible, however very demanding and difficult to build at current state. We also showed with commercial modules that the high temperature energy harvester could power a Wi-Fi at current size of 1 cm2 and 0.4 g if a durable prototype with 7 couples could be manufactured successfully.
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| 41. |
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| 42. |
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| 43. |
- Köhler, S.J., et al.
(author)
-
Climate's control of intra-annual and interannual variability of total organic carbon concentration and flux in two contrasting boreal landscape elements
- 2008
-
In: Journal of Geophysical Research - Biogeosciences. - : American Geophysical Union (AGU). - 2169-8953 .- 2169-8961. ; 113:G3
-
Journal article (peer-reviewed)abstract
- [1] Large spatial and temporal variations in stream total organic carbon (TOC) concentration and export occurred during an 11-year observation period (1993-2003) in a boreal headwater catchment. TOC flux and concentration patterns from mire- and forest-dominated subcatchments differed ( mean annual flux 8.2 g m(-2)a(-1) versus 5.8 g m(-2) a(-1)). Temporal variations in stream TOC concentrations in both landscape types were primarily driven by variations in streamflow, with the mire stream generally diluting by half with increased runoff during spring flood and TOC from the forested landscape increasing during runoff peaks irrespective of season. Average TOC concentration in the mire stream in the snow-free season increased with increased seasonal precipitation from around 20 to 40 mg L-1 but then dropped to around 35 mg L-1 during very wet years. Average snow-free season TOC concentration at the forested site remained stable when summer precipitation was below average but then increased from 10 to around 25 mg L-1 during exceptionally wet years. For both the forested subcatchment and the whole catchment, TOC concentrations increased during the warm summer months during wet years, but no such increase occurred during dry years. Interannual variations in TOC flux were primarily driven by variations during the snow-free period. Wet years decreased the relative TOC export from the mire and favored the relative export of TOC from areas dominated by forest, an observation that also held true on a larger scale when similar landscape types were considered. Predicted climate change in rainfall and temperature patterns will affect the amount and character of TOC exported downstream from boreal landscapes with a mix of forest and mire.
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| 44. |
- Köhler, S. J., et al.
(author)
-
Dynamics of stream water TOC concentrations in a boreal headwater catchment : Controlling factors and implications for climate scenarios
- 2009
-
In: Journal of Hydrology. - : Elsevier BV. - 0022-1694 .- 1879-2707. ; 373:1-2, s. 44-56
-
Journal article (peer-reviewed)abstract
- Two different but complementary modelling approaches for reproducing the observed dynamics of total organic carbon (TOC) in a boreal stream are presented. One is based on a regression analysis, while the other is based on riparian soil conditions using a convolution of flow and concentration. Both approaches are relatively simple to establish and help to identify gaps in the process understanding of the TOC transport from soils to catchments runoff. The largest part of the temporal variation of stream TOC concentrations (4-46 mg L-1) in a forested headwater stream in the boreal zone in northern Sweden may be described using a four-parameter regression equation that has runoff and transformed air temperature as sole input variables. Runoff is assumed to be a proxy for soil wetness conditions and changing flow pathways which in turn caused most of the stream TOC variation. Temperature explained a significant part of the observed inter-annual variability. Long-term riparian hydrochemistry in soil solutions within 4 m of the stream also captures a surprisingly large part of the observed variation of stream TOC and highlights the importance of riparian soils. The riparian zone was used to reproduce stream TOC with the help of a convolution model based on flow and average riparian chemistry as input variables. There is a significant effect of wetting of the riparian soil that translates into a memory effect for subsequent episodes and thus contributes to controlling stream TOC concentrations. Situations with high flow introduce a large amount of variability into stream water TOC that may be related to memory effects, rapid groundwater fluctuations and other processes not identified so far. Two different climate scenarios for the region based on the IPCC scenarios were applied to the regression equation to test what effect the expected increase in precipitation and temperature and resulting changes in runoff would have on stream TOC concentrations assuming that the soil conditions remain unchanged. Both scenarios resulted in a mean increase of stream TOC concentrations of between 1.5 and 2.5 mg L-1 during the snow free season, which amounts to approximately 15% more TOC export compared to present conditions. Wetter and warmer conditions in the late autumn led to a difference of monthly average TOC of up to 5 mg L-1, suggesting that stream TOC may be particularly susceptible to climate variability during this season.
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| 45. |
- Lerceteau-Köhler, Estelle, et al.
(author)
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QTL analysis for fruit quality traits in octoploid strawberry (Fragaria x ananassa)
- 2004
-
In: PROCEEDINGS OF THE XITH EUCARPIA SYMPOSIUM ON FRUIT BREEDING AND GENETICS, VOLS 1 AND 2. - : INT SOC HORTICULTURAL SCIENCE. ; , s. 331-335
-
Conference paper (peer-reviewed)abstract
- Mapping of quantitative trait loci (QTL) controlling components of strawberry (Fragaria x ananassa Duch., 2n=8x=56) fruit quality can be used to provide a better understanding of their genetic control, and to develop marker assisted selection for breeders. For this purpose, a segregating population of 213 individuals of a cross between ‘Capitola’ and CF1116, two genotypes with many contrasting fruit quality traits, was used for genetic mapping. A total of 34 traits involved in fruit quality were evaluated, including developmental and fruit aspect related traits, texture related traits, fruit acidity, sugar and ascorbate concentrations. Amino acid concentrations were quantified using one-dimensional proton NMR spectroscopy. Most of the traits except the amino acid concentrations were evaluated during two successive years. A total of 22 significant QTLs were detected by simple interval mapping (LOD > 3.0) in year 1, four on the female map and 18 on the male map, whereas 17 were detected in year 2, ten on the female map and seven on the male map. Only two QTLs could be detected in both years. When removing the year effect, 22 QTLs were observed, eight on the female and 14 on the male map. The percentages of phenotypic variance explained by each QTL ranged from 6.5% to 16.0%.
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| 46. |
- Liu, Ning-Ning, et al.
(author)
-
Intersection of phosphate transport, oxidative stress and TOR signalling in Candida albicans virulence
- 2018
-
In: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 14:7
-
Journal article (peer-reviewed)abstract
- Phosphate is an essential macronutrient required for cell growth and division. Pho84 is the major high-affinity cell-surface phosphate importer of Saccharomyces cerevisiae and a crucial element in the phosphate homeostatic system of this model yeast. We found that loss of Candida albicans Pho84 attenuated virulence in Drosophila and murine oropharyngeal and disseminated models of invasive infection, and conferred hypersensitivity to neutrophil killing. Susceptibility of cells lacking Pho84 to neutrophil attack depended on reactive oxygen species (ROS): pho84-/- cells were no more susceptible than wild type C. albicans to neutrophils from a patient with chronic granulomatous disease, or to those whose oxidative burst was pharmacologically inhibited or neutralized. pho84-/- mutants hyperactivated oxidative stress signalling. They accumulated intracellular ROS in the absence of extrinsic oxidative stress, in high as well as low ambient phosphate conditions. ROS accumulation correlated with diminished levels of the unique superoxide dismutase Sod3 in pho84-/- cells, while SOD3 overexpression from a conditional promoter substantially restored these cells' oxidative stress resistance in vitro. Repression of SOD3 expression sharply increased their oxidative stress hypersensitivity. Neither of these oxidative stress management effects of manipulating SOD3 transcription was observed in PHO84 wild type cells. Sod3 levels were not the only factor driving oxidative stress effects on pho84-/- cells, though, because overexpressing SOD3 did not ameliorate these cells' hypersensitivity to neutrophil killing ex vivo, indicating Pho84 has further roles in oxidative stress resistance and virulence. Measurement of cellular metal concentrations demonstrated that diminished Sod3 expression was not due to decreased import of its metal cofactor manganese, as predicted from the function of S. cerevisiae Pho84 as a low-affinity manganese transporter. Instead of a role of Pho84 in metal transport, we found its role in TORC1 activation to impact oxidative stress management: overexpression of the TORC1-activating GTPase Gtr1 relieved the Sod3 deficit and ROS excess in pho84-/- null mutant cells, though it did not suppress their hypersensitivity to neutrophil killing or hyphal growth defect. Pharmacologic inhibition of Pho84 by small molecules including the FDA-approved drug foscarnet also induced ROS accumulation. Inhibiting Pho84 could hence support host defenses by sensitizing C. albicans to oxidative stress.
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| 47. |
- Reimer, Paula J., et al.
(author)
-
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0-55 cal kBP)
- 2020
-
In: Radiocarbon. - 0033-8222. ; 62:4, s. 725-757
-
Journal article (peer-reviewed)abstract
- Radiocarbon (C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
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| 48. |
- Schenekar, T., et al.
(author)
-
Fine-scale phylogeographic contact zone in Austrian brown trout Salmo trutta reveals multiple waves of post-glacial colonization and a pre-dominance of natural versus anthropogenic admixture
- 2014
-
In: Conservation Genetics. - : SPRINGER. - 1566-0621 .- 1572-9737. ; 15:3, s. 561-572
-
Journal article (peer-reviewed)abstract
- Two major mtDNA lineages of brown trout come into contact in the upper Danube basin of Central Europe. The region is additionally confronted with stock management programs that often use domesticated foreign strains creating confusion as to what constitutes native and non-native populations as well as how to define major management units. In a unique system in north eastern Austria we provide additional support that the so-called Atlantic lineage of brown trout is native to the upper Danube and provide a high resolution microsatellite screening protocol that clearly distinguishes between natural and anthropogenic introgression, with the latter being minimal. Sequencing of 6,000 bp of mtDNA also shows that domesticated stocks primarily stem from a distinct albeit genetically diverse sub-clade of the Atlantic lineage, approximately 50,000-100,000 years divergent from the native Atlantic stocks, thought to have expanded into the region during the Holocene. The futility in defining large-scale management units based on mtDNA lineages for such broadly distributed and highly fragmented species is discussed.
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| 49. |
- Sigolaeva, Larisa, et al.
(author)
-
Long-term stable poly(ionic liquid)/MWCNTs inks enable enhanced surface modification for electrooxidative detection and quantification of dsDNA
- 2019
-
In: Polymer. - : Elsevier BV. - 0032-3861 .- 1873-2291. ; 168, s. 95-103
-
Journal article (peer-reviewed)abstract
- This work demonstrates the use of imidazolium-based poly(ionic liquid)s (PILs) as efficient dispersants of multiwalled carbon nanotubes (MWCNTs). With these polymeric dispersants, highly stable fine dispersions of MWCNTs (inks) can be easily prepared in aqueous media and applied for rather simple but efficient surface modification of screen-printed electrodes (SPEs). Such a modification of SPEs remarkably increases the electroactive surface area and accelerates the electron transfer rate due to synergistic combination of specific features of MWCNTs such as strong adsorptive property and high specific surface with the advantages of PILs like ion conductivity and dispersability. We further show that the PIL/MWCNT-modified SPEs can be beneficially utilized for direct electrochemical analysis of double stranded DNA (dsDNA). Specifically, it is exemplified by the direct electrooxidation of guanine and adenine bases in salmon testes dsDNA chosen as a model system. The linear ranges for the determination of dsDNA correspond to 5-500 mu g/mL for the oxidative peak of guanine and 0.5-50 mu g/mL for the oxidative peak of adenine. This makes direct electrochemical dsDNA detection with the use of the easy-preparable PIL/MWCNT-modified SPEs strongly competing to currently applied spectral and fluorescent techniques. Furthermore, we show that the developed constructs are capable of sensing a single point mutation in the 12-bases single-stranded DNA fragments. Such detection is of high clinical significance in choosing an adequate anticancer treatment, where the electrochemical identification of the point mutation could offer time and cost benefits.
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| 50. |
- Sjöstedt, Carin S., et al.
(author)
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Chemical Equilibrium Modeling of Organic Acids, pH, Aluminum, and Iron in Swedish Surface Waters
- 2010
-
In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:22, s. 8587-8593
-
Journal article (peer-reviewed)abstract
- A consistent chemical equilibrium model that calculates pH from charge balance constraints and aluminum and iron speciation in the presence of natural organic matter is presented. The model requires input data for total aluminum, iron, organic carbon, fluoride, sulfate, and charge balance ANC. The model is calibrated to pH measurements (n = 322) by adjusting the fraction of active organic matter only, which results in an error of pH prediction on average below 0.2 pH units. The small systematic discrepancy between the analytical results for the monomeric aluminum fractionation and the model results is corrected for separately for two different fractionation techniques (n = 499) and validated on a large number In = 3419) of geographically widely spread samples all over Sweden. The resulting average error for inorganic monomeric aluminum is around 1 mu M. In its present form the model is the first internally consistent modeling approach for Sweden and may now be used as a tool for environmental quality management Soil gibbsite with a log *K-s of 8.29 at 25 degrees C together with a pH dependent loading function that uses molar Al/C ratios describes the amount of aluminum in solution in the presence of organic matter if the pH is roughly above 6.0.
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