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Sökning: WFRF:(Ashton Michael C.)

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1.
  • Kanai, M, et al. (författare)
  • 2023
  • swepub:Mat__t
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2.
  • Niemi, MEK, et al. (författare)
  • 2021
  • swepub:Mat__t
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3.
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:2
  • Tidskriftsartikel (refereegranskat)
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4.
  • Acharya, B. S., et al. (författare)
  • Introducing the CTA concept
  • 2013
  • Ingår i: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 43, s. 3-18
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project. (C) 2013 Elsevier B.V. All rights reserved.
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5.
  • Muscarella, Robert, et al. (författare)
  • The global abundance of tree palms
  • 2020
  • Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 29:9, s. 1495-1514
  • Tidskriftsartikel (refereegranskat)abstract
    • AimPalms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change.LocationTropical and subtropical moist forests.Time periodCurrent.Major taxa studiedPalms (Arecaceae).MethodsWe assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure.ResultsOn average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work.ConclusionsTree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.
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6.
  • Hoshino, Ayuko, et al. (författare)
  • Extracellular Vesicle and Particle Biomarkers Define Multiple Human Cancers
  • 2020
  • Ingår i: Cell. - : CELL PRESS. - 0092-8674 .- 1097-4172. ; 182:4, s. 1044-
  • Tidskriftsartikel (refereegranskat)abstract
    • There is an unmet clinical need for improved tissue and liquid biopsy tools for cancer detection. We investigated the proteomic profile of extracellular vesicles and particles (EVPs) in 426 human samples from tissue explants (TEs), plasma, and other bodily fluids. Among traditional exosome markers, CD9, HSPA8, ALIX, and HSP90AB1 represent pan-EVP markers, while ACTB, MSN, and RAP1B are novel pan-EVP markers. To confirm that EVPs are ideal diagnostic tools, we analyzed proteomes of TE- (n =151) and plasma-derived (n =120) EVPs. Comparison of TE EVPs identified proteins (e.g., VCAN, TNC, and THBS2) that distinguish tumors from normal tissues with 90% sensitivity/94% specificity. Machine-learning classification of plasma-derived EVP cargo, including immunoglobulins, revealed 95% sensitivity/90% specificity in detecting cancer Finally, we defined a panel of tumor-type-specific EVP proteins in TEs and plasma, which can classify tumors of unknown primary origin. Thus, EVP proteins can serve as reliable biomarkers for cancer detection and determining cancer type.
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7.
  • Richards, Stephen, et al. (författare)
  • Genome Sequence of the Pea Aphid Acyrthosiphon pisum
  • 2010
  • Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 8:2, s. e1000313-
  • Tidskriftsartikel (refereegranskat)abstract
    • Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems.
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8.
  • Needham, E. J., et al. (författare)
  • Brain injury in COVID-19 is associated with dysregulated innate and adaptive immune responses
  • 2022
  • Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 145:11, s. 4097-4107
  • Tidskriftsartikel (refereegranskat)abstract
    • COVID-19 is associated with neurological complications including stroke, delirium and encephalitis. Furthermore, a post-viral syndrome dominated by neuropsychiatric symptoms is common, and is seemingly unrelated to COVID-19 severity. The true frequency and underlying mechanisms of neurological injury are unknown, but exaggerated host inflammatory responses appear to be a key driver of COVID-19 severity. We investigated the dynamics of, and relationship between, serum markers of brain injury [neurofilament light (NfL), glial fibrillary acidic protein (GFAP) and total tau] and markers of dysregulated host response (autoantibody production and cytokine profiles) in 175 patients admitted with COVID-19 and 45 patients with influenza. During hospitalization, sera from patients with COVID-19 demonstrated elevations of NfL and GFAP in a severity-dependent manner, with evidence of ongoing active brain injury at follow-up 4 months later. These biomarkers were associated with elevations of pro-inflammatory cytokines and the presence of autoantibodies to a large number of different antigens. Autoantibodies were commonly seen against lung surfactant proteins but also brain proteins such as myelin associated glycoprotein. Commensurate findings were seen in the influenza cohort. A distinct process characterized by elevation of serum total tau was seen in patients at follow-up, which appeared to be independent of initial disease severity and was not associated with dysregulated immune responses unlike NfL and GFAP. These results demonstrate that brain injury is a common consequence of both COVID-19 and influenza, and is therefore likely to be a feature of severe viral infection more broadly. The brain injury occurs in the context of dysregulation of both innate and adaptive immune responses, with no single pathogenic mechanism clearly responsible. Needham et al. reveal elevations in blood biomarkers of brain injury in patients hospitalised with COVID-19. The changes, which were severity-dependent, were associated with dysregulated immune responses including increases in pro-inflammatory cytokines and autoantibodies. Ongoing active brain injury could still be seen months after infection.
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9.
  • Ade, Peter, et al. (författare)
  • The Simons Observatory : science goals and forecasts
  • 2019
  • Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
  • Tidskriftsartikel (refereegranskat)abstract
    • The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu K-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu K-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
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10.
  • Nyakutira, C, et al. (författare)
  • High prevalence of the CYP2B6 516G-->T(*6) variant and effect on the population pharmacokinetics of efavirenz in HIV/AIDS outpatients in Zimbabwe.
  • 2007
  • Ingår i: European Journal of Clinical Pharmacology. - : Springer Science and Business Media LLC. - 0031-6970 .- 1432-1041. ; 64:4, s. 357-365
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: The study sought to investigate the relationship between efavirenz exposure and the CYP2B6 516G-->T(*6) genotype in HIV/AIDS outpatients, using pharmacokinetic modelling and simulation. METHODS: Blood samples where obtained from 74 outpatients treated with a combination regimen including 600 mg efavirenz daily for a duration of at least 3 weeks at clinics in Harare, Zimbabwe. The subjects were genotyped for the major CYP2B6 variant, CYP2B6*6, associated with reduced enzyme activity, using a PCR-RFLP method. Efavirenz plasma concentrations were determined by HPLC-UV. Population pharmacokinetic modelling and simulation of the data were performed in NONMEM VI. RESULTS: A high allele frequency of the CYP2B6*6 allele of 49% was observed. Efavirenz plasma concentrations were above 4 mg/L in 50% of the patients. Genotype and sex were identified as predictive covariates of efavirenz disposition. Pharmacokinetic parameter estimates indicate that a dose reduction to 400 mg efavirenz per day is possible in patients homozygous for the CYP2B6*6 genotype without compromising therapeutic efficacy. CONCLUSION: The CYP2B6*6 allele occurs at a high frequency in people of African origin and is associated with high efavirenz concentrations. Simulations indicate that an a priori 35% dose reduction in homozygous CYP2B6*6 patients would maintain drug exposure within the therapeutic range in this group of patients. Our preliminary results suggest the conduct of a prospective clinical dose optimization study to evaluate the utility of genotype-driven dose adjustment in this population.
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11.
  • Abazajian, Kevork, et al. (författare)
  • CMB-S4 : Forecasting Constraints on Primordial Gravitational Waves
  • 2022
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 926:1
  • Tidskriftsartikel (refereegranskat)abstract
    • CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, r, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2–3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for r > 0.003 at greater than 5σ, or in the absence of a detection, of reaching an upper limit of r < 0.001 at 95% CL.
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12.
  • Cooper, Declan L.M., et al. (författare)
  • Consistent patterns of common species across tropical tree communities
  • 2024
  • Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625:7996, s. 728-734
  • Tidskriftsartikel (refereegranskat)abstract
    • Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations 1–6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories 7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.
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13.
  • Frank, Brandon, et al. (författare)
  • Plasma p-tau181 shows stronger network association to Alzheimer's disease dementia than neurofilament light and total tau.
  • 2022
  • Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - : Wiley. - 1552-5279. ; 18:8, s. 1523-1536
  • Tidskriftsartikel (refereegranskat)abstract
    • We examined the ability of plasma hyperphosphorylated tau (p-tau)181 to detect cognitive impairment due to Alzheimer's disease (AD) independently and in combination with plasma total tau (t-tau) and neurofilament light (NfL).Plasma samples were analyzed using the Simoa platform for 235 participants with normal cognition (NC), 181 with mild cognitive impairment due to AD (MCI), and 153 with AD dementia. Statistical approaches included multinomial regression and Gaussian graphical models (GGMs) to assess a network of plasma biomarkers, neuropsychological tests, and demographic variables.Plasma p-tau181 discriminated AD dementia from NC, but not MCI, and correlated with dementia severity and worse neuropsychological test performance. Plasma NfL similarly discriminated diagnostic groups. Unlike plasma NfL or t-tau, p-tau181 had a direct association with cognitive diagnosis in a bootstrapped GGM.These results support plasma p-tau181 for the detection of AD dementia and the use of blood-based biomarkers for optimal disease detection.
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14.
  • Helena, Kevin J., et al. (författare)
  • Effects of oral administration of synthesized delta-amides of eflornithine in the rat
  • 2010
  • Ingår i: ARZNEIMITTEL-FORSCHUNG-DRUG RESEARCH. - 0004-4172. ; 60:11, s. 682-688
  • Tidskriftsartikel (refereegranskat)abstract
    • The purpose of this study was to synthesize a series of delta-amide derivatives of the antitrypanosomal drug eflornithine (2,5-diamino-2-(difluoromethyl)pentanoic acid hydrochloride, DMFO, CAS 70052-12-9), to determine their physicochemical properties and to assess whether they convert to eflornithine in vivo and if so, whether higher systemic exposure to eflornithine could be achieved by increase intestinal absorption, suggesting an oral treatment to be possible. The derivatives were synthesized by amidation of eflornithine on its delta-amino group using acyl chlorides. The partition coefficients (log D, pH = 7.4) were found to be between -0.78 +/- 1.07 and -0.07 +/- 1.08 while the aqueous solubility (Sw), which as determined in phosphate buffered solution (pH 7.4), ranged from 11.13 +/- 0.32 to 28.74 +/- 0.36 mg/mL. The synthesized compounds were thus mostly more lipophilic than eflornithine itself (log D = -0.98 +/- 0.88, Sw = 34.96 +/- 0.37 mg/mL). The intestinal absorption was assessed by plasma analysis after oral administration of each compound to Sprague-Dawley rats. The biological data revealed that the derivatives were either not absorbed from the gastro-intestinal tract or not metabolized into eflornithine as no parent drug was detected in the plasma.
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15.
  • Lee, Kibeom, et al. (författare)
  • Personality, Religion, and Politics : An Investigation in 33 Countries
  • 2018
  • Ingår i: European Journal of Personality. - : SAGE Publications. - 0890-2070 .- 1099-0984. ; 32:2, s. 100-115
  • Tidskriftsartikel (refereegranskat)abstract
    • The relations of HEXACO personality factors and religiosity with political orientation were examined in responses collected online from participants in 33 countries (N=141 492). Endorsement of a right-wing political orientation was negatively associated with Honesty-Humility and Openness to Experience and positively associated with religiosity. The strength of these associations varied widely across countries, such that the religiosity-politics correlations were stronger in more religious countries, whereas the personality-politics correlations were stronger in more developed countries. We also investigated the utility of the narrower traits (i.e. facets) that define the HEXACO factors. The Altruism facet (interstitially located between the Honesty-Humility, Agreeableness, and Emotionality axes) was negatively associated with right-wing political orientation, but religiosity was found to suppress this relationship, especially in religious countries. In addition to Altruism, the Greed Avoidance and Modesty facets of the Honesty-Humility factor and the Unconventionality and Aesthetic Appreciation facets of the Openness to Experience factor were also negatively associated with right-wing political orientation. We discuss the utility of examining facet-level personality traits, along with religiosity, in research on the individual difference correlates of political orientation.
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16.
  • Montoliu-Gaya, Laia, et al. (författare)
  • Optimal blood tau species for the detection of Alzheimer's disease neuropathology: an immunoprecipitation mass spectrometry and autopsy study.
  • 2024
  • Ingår i: Acta neuropathologica. - 1432-0533. ; 147:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Plasma-to-autopsy studies are essential for validation of blood biomarkers and understanding their relation to Alzheimer's disease (AD) pathology. Few such studies have been done on phosphorylated tau (p-tau) and those that exist have made limited or no comparison of the different p-tau variants. This study is the first to use immunoprecipitation mass spectrometry (IP-MS) to compare the accuracy of eight different plasma tau species in predicting autopsy-confirmed AD. The sample included 123 participants (AD=69, non-AD=54) from the Boston University Alzheimer's disease Research Center who had an available ante-mortem plasma sample and donated their brain. Plasma samples proximate to death were analyzed by targeted IP-MS for six different tryptic phosphorylated (p-tau-181, 199, 202, 205, 217, 231), and two non-phosphorylated tau (195-205, 212-221) peptides. NIA-Reagan Institute criteria were used for the neuropathological diagnosis of AD. Binary logistic regressions tested the association between each plasma peptide and autopsy-confirmed AD status. Area under the receiver operating curve (AUC) statistics were generated using predicted probabilities from the logistic regression models. Odds Ratio (OR) was used to study associations between the different plasma tau species and CERAD and Braak classifications. All tau species were increased in AD compared to non-AD, but p-tau217, p-tau205 and p-tau231 showed the highest fold-changes. Plasma p-tau217 (AUC=89.8), p-tau231 (AUC=83.4), and p-tau205 (AUC=81.3) all had excellent accuracy in discriminating AD from non-AD brain donors, even among those with CDR<1). Furthermore, p-tau217, p-tau205 and p-tau231 showed the highest ORs with both CERAD (ORp-tau217=15.29, ORp-tau205=5.05 and ORp-tau231=3.86) and Braak staging (ORp-tau217=14.29, ORp-tau205=5.27 and ORp-tau231=4.02) but presented increased levels at different amyloid and tau stages determined by neuropathological examination. Our findings support plasma p-tau217 as the most promising p-tau species for detecting AD brain pathology. Plasma p-tau231 and p-tau205 may additionally function as markers for different stages of the disease.
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17.
  • Potapov, Anton M., et al. (författare)
  • Global fine-resolution data on springtail abundance and community structure
  • 2024
  • Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 11:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.
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18.
  • Srikrishna, Meera, et al. (författare)
  • CT-based volumetric measures obtained through deep learning: Association with biomarkers of neurodegeneration
  • 2024
  • Ingår i: Alzheimers & Dementia. - 1552-5260. ; 20:1, s. 629-640
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTIONCranial computed tomography (CT) is an affordable and widely available imaging modality that is used to assess structural abnormalities, but not to quantify neurodegeneration. Previously we developed a deep-learning-based model that produced accurate and robust cranial CT tissue classification.MATERIALS AND METHODSWe analyzed 917 CT and 744 magnetic resonance (MR) scans from the Gothenburg H70 Birth Cohort, and 204 CT and 241 MR scans from participants of the Memory Clinic Cohort, Singapore. We tested associations between six CT-based volumetric measures (CTVMs) and existing clinical diagnoses, fluid and imaging biomarkers, and measures of cognition.RESULTSCTVMs differentiated cognitively healthy individuals from dementia and prodromal dementia patients with high accuracy levels comparable to MR-based measures. CTVMs were significantly associated with measures of cognition and biochemical markers of neurodegeneration.DISCUSSIONThese findings suggest the potential future use of CT-based volumetric measures as an informative first-line examination tool for neurodegenerative disease diagnostics after further validation.HIGHLIGHTSComputed tomography (CT)-based volumetric measures can distinguish between patients with neurodegenerative disease and healthy controls, as well as between patients with prodromal dementia and controls.CT-based volumetric measures associate well with relevant cognitive, biochemical, and neuroimaging markers of neurodegenerative diseases.Model performance, in terms of brain tissue classification, was consistent across two cohorts of diverse nature.Intermodality agreement between our automated CT-based and established magnetic resonance (MR)-based image segmentations was stronger than the agreement between visual CT and MR imaging assessment.
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19.
  • Timmermann, C., et al. (författare)
  • Neural correlates of the DMT experience assessed with multivariate EEG
  • 2019
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Studying transitions in and out of the altered state of consciousness caused by intravenous (IV) N,N-Dimethyltryptamine (DMT - a fast-acting tryptamine psychedelic) offers a safe and powerful means of advancing knowledge on the neurobiology of conscious states. Here we sought to investigate the effects of IV DMT on the power spectrum and signal diversity of human brain activity (6 female, 7 male) recorded via multivariate EEG, and plot relationships between subjective experience, brain activity and drug plasma concentrations across time. Compared with placebo, DMT markedly reduced oscillatory power in the alpha and beta bands and robustly increased spontaneous signal diversity. Time-referenced and neurophenomenological analyses revealed close relationships between changes in various aspects of subjective experience and changes in brain activity. Importantly, the emergence of oscillatory activity within the delta and theta frequency bands was found to correlate with the peak of the experience - particularly its eyes-closed visual component. These findings highlight marked changes in oscillatory activity and signal diversity with DMT that parallel broad and specific components of the subjective experience, thus advancing our understanding of the neurobiological underpinnings of immersive states of consciousness.
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20.
  • Yakoub, Y., et al. (författare)
  • Longitudinal blood biomarker trajectories in preclinical Alzheimer's disease
  • 2023
  • Ingår i: Alzheimers & Dementia. - 1552-5260. ; 19:12, s. 5620-5631
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Plasma biomarkers are altered years prior to Alzheimer's disease (AD) clinical onset. Methods: We measured longitudinal changes in plasma amyloid-beta (A beta)(42/40) ratio, pTau181, pTau231, neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) in a cohort of older adults at risk of AD (n = 373 total, n = 229 with A beta and tau positron emission tomography [PET] scans) considering genetic and demographic factors as possible modifiers of these markers' progression. Results: A beta(42/40) ratio concentrations decreased, while NfL and GFAP values increased over the 4-year follow-up. Apolipoprotein E (APOE) epsilon 4 carriers showed faster increase in plasma pTau181 than non-carriers. Older individuals showed a faster increase in plasma NfL, and females showed a faster increase in plasma GFAP values. In the PET subsample, individuals both A beta-PET and tau-PET positive showed faster plasma pTau181 and GFAP increase compared to PET-negative individuals. Discussion: Plasma markers can track biological change over time, with plasma pTau181 and GFAP markers showing longitudinal change in individuals with preclinical AD.
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21.
  • Adie, Bailey Ashton, et al. (författare)
  • Careers, citations, bibliometrics, and impact : perspectives of new and emerging researchers
  • 2024
  • Ingår i: How to get published in the best tourism journals. - Cheltenham : Edward Elgar Publishing. - 9781035300600 - 9781035300594 ; , s. 211-238
  • Bokkapitel (refereegranskat)abstract
    • This chapter brings together invited contributions from new and emerging academics with respect to their experiences and how publishing demands affect their careers and life, and vice versa. The provision of such experiences is important as it conveys the reality of publishing from a real-world context with respect to the pressures we face, especially when starting on the academic ladder. Authors were given a broad scope with respect to their contributions and the results are provided with only very minor editing. They have also been presented anonymously, or rather collectively, because although there are clearly different perspectives, emphasises, and interpretations, there are also commonalities in the contributors’ experiences. Nevertheless, as the reader will see, there are a number of common themes that emerge. Following the perspectives of the different contributions the chapter will discuss some of the main issues that emerge and their implications, including some of the darker aspects of the pressures of publishing.
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22.
  • Adie, Bailey Ashton, et al. (författare)
  • Conclusions and future directions
  • 2023
  • Ingår i: Second Homes and Climate Change. - : Routledge. - 9781003091295 - 9780367549466 - 9781000905533 ; , s. 157-165
  • Bokkapitel (refereegranskat)abstract
    • This chapter presents a synthesis of the entire edited collection. In doing so, three key themes are developed which emerged from the chapter contributions. These themes are as follows: planning for climate change, second home community responses to climate change, and second home impacts on climate change. These themes are elaborated in the context of the relevant supporting chapters before the argument shifts into a discussion of future directions for second home and climate change research. In particular, the need for more research in the areas of planning and policy, psychological responses of second home owners, and overall resilience is stressed.
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23.
  • Adie, Bailey Ashton, et al. (författare)
  • Just Because It Seems Impossible, Doesn't Mean We Shouldn't At Least Try : The Need for Longitudinal Perspectives on Tourism Partnerships and the SDGs
  • 2022
  • Ingår i: Journal of Sustainable Tourism. - : Taylor & Francis Group. - 0966-9582 .- 1747-7646. ; 30:10, s. 2282-2297
  • Tidskriftsartikel (refereegranskat)abstract
    • Sustainable Development Goal (SDG) 17 highlights the importance that the partnership narrative plays in the implementation of SDGs. However, given the brevity of many development projects, these partnerships are often developed and concluded rapidly, with little attention given to longer-term implications or success. This paper argues that in order to create and develop partnerships that properly address the SDGs, it is imperative that a process perspective is developed that takes into account the range of stakeholders and interests, values, and the power relations between actors prior to and during the project together with a comprehensive understanding of what is success. This requires a full awareness of the project's context and previous interventions, activities, and policies. In order to illustrate the necessity of longitudinal partnerships and perspectives, a case study, a community-based development project in New Delhi, India, is used. The goal of the project has been to ensure that the community is actively involved in the entire process, eventually becoming owners of the interventions so that, when the project and partnership eventually ends, the community continues to benefit. Examples from the project are used to emphasize the importance of long-term planning and partnership driven by context-specificity, implementation processes and policy-awareness.
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24.
  • Adie, Bailey Ashton, et al. (författare)
  • Urban tourism and urban socialist and communist heritage : beyond tragedy and farce?
  • 2017
  • Ingår i: International Journal of Tourism Cities. - : Emerald Group Publishing Limited. - 2056-5607 .- 2056-5615. ; 3:3, s. 291-304
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose - Existing literature on state socialist and communist heritage as a form of tourist consumption predominately focuses on destination contexts, such as the former Soviet countries and the few remaining state communist countries (i.e. China, North Korea and Cuba). As a result, the visitation to places linked to the history of socialism and communism in the so-called western pluralist democracies has often been overlooked and, at most, unacknowledged, especially as most research on "socialist" heritage focuses on sites connected to statist heritage rather than sites connected to socialist movements. The paper aims to discuss these issues. Design/methodology/approach - This paper aims to fill the gap in terms of research focusing on these types of sites, with evidence from a range of countries in Europe and the Americas. It does so by illustrating the presence and engagement with official and non-official communist/socialist heritage at varying levels of commodification. Findings - The paper concludes that not only is there a need to broaden the concept of socialist heritage but that its framing needs to continue to be understood from present day ideological discourses and struggles with respect to the marking of urban heritage tourist locations. Originality/value - This contribution advocates the broadening of the concept of socialist heritage by acknowledging the relevance of "hidden" urban sites related to key socialist thinkers, socialist opposition to fascism, and civil wars in which the socialist movement was involved, while also drawing parallels between the levels of socialist/heritage recognition and use as a commodity in relation to the historical narrative within the studied countries.
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25.
  • Adie, Bailey Ashton, et al. (författare)
  • Who visits World Heritage? : A comparative analysis of three cultural sites
  • 2017
  • Ingår i: Journal of Heritage Tourism. - : Taylor & Francis. - 1743-873X .- 1747-6631. ; 12:1, s. 67-80
  • Tidskriftsartikel (refereegranskat)abstract
    • Heritage tourism is a growing segment of the modern tourism industry, and several studies have been undertaken to identify the individuals who participate in this type of tourism. These have indicated that heritage tourists, generally, are middle class, middle age, and well educated. However, despite their iconic role, there has been relatively little attention paid to profile of visitors to World Heritage Sites. This study aims to better understand the demography of this specific tourism segment through the use of survey-based research at three geographically diverse World Heritage Sites: Independence Hall in the USA, Studenica Monastery in Serbia, and the Archaeological Site of Volubilis in Morocco. Through the use of descriptive statistics, several over-arching trends were noted among the three sites. World Heritage Site visitors were found to be very well educated, but they did not have any similarities in relation to age, income, or residence, which contrasts the "general" heritage tourist typology. However, there were several World Heritage specific trends. While this work is a snapshot of the three sites under study and thus is difficult to generalize, it provides the basis for more comprehensive demographic research on visitors to World Heritage Sites.
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26.
  • Adie, Bailey Ashton, et al. (författare)
  • World Heritage as a placebo brand : a comparative analysis of three sites and marketing implications
  • 2018
  • Ingår i: Journal of Sustainable Tourism. - : Routledge. - 0966-9582 .- 1747-7646. ; 26:3, s. 399-415
  • Tidskriftsartikel (refereegranskat)abstract
    • The UNESCO World Heritage (WH) List is often regarded as a successful tourism brand that motivates site nominations. However, there is relatively little research dealing specifically with WH brand attraction effects, and what does exist shows conflicting results. There is a significant research gap in terms of awareness of the WH brand and its potential impact on visitation, which this study seeks to fill through a comparative analysis of three diverse case studies: Independence Hall, USA; Studenica Monastery, Serbia; and the Archaeological Site of Volubilis, Morocco. Survey data (n = 771) from these three sites were collected and analyzed resulting in three distinct clusters of visitors. One of the clusters does exhibit higher levels of awareness of the WH brand, but members of this group were not motivated by this knowledge when planning their site visit. It is concluded that the WH brand may function as a placebo, and that its importance may be tied more to political interests than economic advancement. Thus, dependency on the WH List for tourism development may potentially be detrimental for locations in the long term. The WH brand's placebo effect could result in long-term problems for both the site and those whose livelihoods depend on tourism.
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27.
  • Ashton, Nicholas J., et al. (författare)
  • A multicentre validation study of the diagnostic value of plasma neurofilament light
  • 2021
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12, s. 1-12
  • Tidskriftsartikel (refereegranskat)abstract
    • Increased cerebrospinal fluid neurofilament light (NfL) is a recognized biomarker for neurodegeneration that can also be assessed in blood. Here, we investigate plasma NfL as a marker of neurodegeneration in 13 neurodegenerative disorders, Down syndrome, depression and cognitively unimpaired controls from two multicenter cohorts: King's College London (n = 805) and the Swedish BioFINDER study (n = 1,464). Plasma NfL was significantly increased in all cortical neurodegenerative disorders, amyotrophic lateral sclerosis and atypical parkinsonian disorders. We demonstrate that plasma NfL is clinically useful in identifying atypical parkinsonian disorders in patients with parkinsonism, dementia in individuals with Down syndrome, dementia among psychiatric disorders, and frontotemporal dementia in patients with cognitive impairment. Data-driven cut-offs highlighted the fundamental importance of age-related clinical cut-offs for disorders with a younger age of onset. Finally, plasma NfL performs best when applied to indicate no underlying neurodegeneration, with low false positives, in all age-related cut-offs.
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28.
  • Ashton, Nicholas J., et al. (författare)
  • A plasma protein classifier for predicting amyloid burden for preclinical Alzheimer's disease.
  • 2019
  • Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 5:2
  • Tidskriftsartikel (refereegranskat)abstract
    • A blood-based assessment of preclinical disease would have huge potential in the enrichment of participants for Alzheimer's disease (AD) therapeutic trials. In this study, cognitively unimpaired individuals from the AIBL and KARVIAH cohorts were defined as Aβ negative or Aβ positive by positron emission tomography. Nontargeted proteomic analysis that incorporated peptide fractionation and high-resolution mass spectrometry quantified relative protein abundances in plasma samples from all participants. A protein classifier model was trained to predict Aβ-positive participants using feature selection and machine learning in AIBL and independently assessed in KARVIAH. A 12-feature model for predicting Aβ-positive participants was established and demonstrated high accuracy (testing area under the receiver operator characteristic curve = 0.891, sensitivity = 0.78, and specificity = 0.77). This extensive plasma proteomic study has unbiasedly highlighted putative and novel candidates for AD pathology that should be further validated with automated methodologies.
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29.
  • Boberg, Mikael, et al. (författare)
  • Chiral Chromatographic Isolation on Milligram Scale of the Human African Trypanosomiasis Treatment D- and L-Eflornithine.
  • 2020
  • Ingår i: ACS omega. - : American Chemical Society (ACS). - 2470-1343. ; 5:37, s. 23885-23891
  • Tidskriftsartikel (refereegranskat)abstract
    • Eflornithine is a recommended treatment against the otherwise fatal parasitic disease late stage human African trypanosomiasis (HAT), also known as Gambian sleeping sickness. It is administered repeatedly as a racemic mixture intravenously (IV) together with oral nifurtimox. Racemic eflornithine has been investigated in clinical trials for oral dosing. However, due to low systemic exposures at a maximum tolerated oral dose, the drug is continued to be administered IV. The eflornithine enantiomers, D- and L-eflornithine, have different affinities to the target enzyme ornithine decarboxylase, suggesting that the pharmacodynamics of the enantiomers may differ. The aim of this study was to develop a method for isolation of d- and l-eflornithine from a racemic mixture. Several chiral stationary phases (CSPs) were evaluated for enantioselectivity using supercritical fluid chromatography (SFC) or high-performance liquid chromatography (HPLC). None of the tested CSPs rendered separation of the enantiomers in SFC mode. Separation of the enantiomers with SFC on the CSP Chiralpak IG was only achieved on an analytical scale after derivatization with ortho-phthalaldehyde (OPA). This was the first reported enantioselective SFC method for an eflornithine derivate. However, due to poor stability, the eflornithine-OPA derivates degraded and no chemically pure enantiomers were obtained. The CSP that showed enantioselectivity in HPLC mode was Chirobiotic R, which resulted in a successful isolation on a semipreparative milligram scale. The isolated eflornithine enantiomers will be tested in nonclinical in vitro and in vivo studies to support and assess the feasibility of a future clinical program with an oral HAT treatment.
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30.
  • Bott, Lukas Thomas, et al. (författare)
  • Coulomb dissociation of O-16 into He-4 and C-12
  • 2023
  • Ingår i: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
  • Konferensbidrag (refereegranskat)abstract
    • We measured the Coulomb dissociation of O-16 into He-4 and C-12 within the FAIR Phase-0 program at GSI Helmholtzzentrum fur Schwerionenforschung Darmstadt, Germany. From this we will extract the photon dissociation cross section O-16(alpha,gamma)C-12, which is the time reversed reaction to C-12(alpha,gamma)O-16. With this indirect method, we aim to improve on the accuracy of the experimental data at lower energies than measured so far. The expected low cross section for the Coulomb dissociation reaction and close magnetic rigidity of beam and fragments demand a high precision measurement. Hence, new detector systems were built and radical changes to the (RB)-B-3 setup were necessary to cope with the high-intensity O-16 beam. All tracking detectors were designed to let the unreacted O-16 ions pass, while detecting the C-12 and He-4.
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31.
  • Chong, J. R., et al. (författare)
  • Blood-based high sensitivity measurements of beta-amyloid and phosphorylated tau as biomarkers of Alzheimer's disease: a focused review on recent advances
  • 2021
  • Ingår i: Journal of Neurology Neurosurgery and Psychiatry. - : BMJ. - 0022-3050 .- 1468-330X. ; 92:11, s. 1231-1241
  • Forskningsöversikt (refereegranskat)abstract
    • Discovery and development of clinically useful biomarkers for Alzheimer's disease (AD) and related dementias have been the focus of recent research efforts. While cerebrospinal fluid and positron emission tomography or MRI-based neuroimaging markers have made the in vivo detection of AD pathology and its consequences possible, the high cost and invasiveness have limited their widespread use in the clinical setting. On the other hand, advances in potentially more accessible blood-based biomarkers had been impeded by lack of sensitivity in detecting changes in markers of the hallmarks of AD, including amyloid-beta (A beta) peptides and phosphorylated tau (P-tau). More recently, however, emerging technologies with superior sensitivity and specificity for measuring A beta and P-tau have reported high concordances with AD severity. In this focused review, we describe several emerging technologies, including immunoprecipitation-mass spectrometry (IP-MS), single molecule array and Meso Scale Discovery immunoassay platforms, and appraise the current literature arising from their use to identify plaques, tangles and other AD-associated pathology. While there is potential clinical utility in adopting these technologies, we also highlight the further studies needed to establish A beta and P-tau as blood-based biomarkers for AD, including validation with existing large sample sets, new independent cohorts from diverse backgrounds as well as population-based longitudinal studies. In conclusion, the availability of sensitive and reliable measurements of A beta peptides and P-tau species in blood holds promise for the diagnosis, prognosis and outcome assessments in clinical trials for AD.
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32.
  • Chong, J. R., et al. (författare)
  • Brain atrophy and white matter hyperintensities are independently associated with plasma neurofilament light chain in an Asian cohort of cognitively impaired patients with concomitant cerebral small vessel disease
  • 2023
  • Ingår i: Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring. - : Wiley. - 2352-8729. ; 15:1
  • Tidskriftsartikel (refereegranskat)abstract
    • IntroductionPlasma neurofilament light chain (NfL) is a potential biomarker for neurodegeneration in Alzheimer's disease (AD), ischemic stroke, and non-dementia cohorts with cerebral small vessel disease (CSVD). However, studies of AD in populations with high prevalence of concomitant CSVD to evaluate associations of brain atrophy, CSVD, and amyloid beta (A beta) burden on plasma NfL are lacking. MethodsAssociations were tested between plasma NfL and brain A beta, medial temporal lobe atrophy (MTA) as well as neuroimaging features of CSVD, including white matter hyperintensities (WMH), lacunes, and cerebral microbleeds. ResultsWe found that participants with either MTA (defined as MTA score >= 2; neurodegeneration [N]+WMH-) or WMH (cut-off for log-transformed WMH volume at 50th percentile; N-WMH+) manifested increased plasma NfL levels. Participants with both pathologies (N+WMH+) showed the highest NfL compared to N+WMH-, N-WMH+, and N-WMH- individuals. DiscussionPlasma NfL has potential utility in stratifying individual and combined contributions of AD pathology and CSVD to cognitive impairment.
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33.
  • Cloete, TT, et al. (författare)
  • Mono-, di- and trisubstituted derivatives of eflornithine: synthesis for in vivo delivery of DL-alpha-difluoromethylornithine in plasma
  • 2011
  • Ingår i: Arzneimittelforschung Drug Research. - 0004-4172. ; 61:5, s. 317-325
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of this study was to synthesize a series of mono-, di- and trisubstituted derivatives of the human African trypanosomiasis drug eflornithine (α-difluoro-methylornithine, DMFO, CAS 70052-12-9) to determine their partition coefficients, and to assess whether they deliver the parent drug in the plasma. If increased plasma concentrations of eflornithine could be achieved in this way, an oral dosage form would be possible. The derivatives, nine in total, were successfully synthesized by multi-step derivatisation of eflornithine on either its α-carboxylic or/and α-amino or/and 5-amino groups by either esterification or/and amidation or/and carbamylation, and their structures confirmed by NMR and MS spectroscopy. The majority of derivatives were more lipophilic than eflornithine with log D values in phosphate buffer solution (pH 7.4) ranging from −1.34 to 1.59 (vs. −0.98 for eflornithine). The in vivo absorption after oral administration to Sprague-Dawley rats showed that no derivative delivered eflornithine in the plasma, indicating that the derivatives were either not absorbed from the gastrointestinal tract or not metabolized to the parent drug. Two of the monosubstituted activities were toxic for T. brucei blood stream forms.
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34.
  • Eckernäs, Emma, 1992, et al. (författare)
  • N,N-dimethyltryptamine affects electroencephalography response in a concentration-dependent manner-A pharmacokinetic/pharmacodynamic analysis
  • 2023
  • Ingår i: Cpt-Pharmacometrics & Systems Pharmacology. - : Wiley. - 2163-8306. ; 12:4, s. 474-486
  • Tidskriftsartikel (refereegranskat)abstract
    • N,N-dimethyltryptamine (DMT) is a psychedelic substance and is being used as a research tool in investigations of the neurobiology behind the human consciousness using different brain imaging techniques. The effects of psychedelics have commonly been studied using electroencephalography (EEG) and have been shown to produce suppression of alpha power and increase in signal diversity. However, the relationship between DMT exposure and its EEG effects has never been quantified. In this work, a population pharmacokinetic/pharmacodynamic analysis was performed investigating the relationship between DMT plasma concentrations and its EEG effects. Data were obtained from a clinical study where DMT was administered by intravenous bolus dose to 13 healthy subjects. The effects on alpha power, beta power, and Lempel-Ziv complexity were evaluated. DMT was shown to fully suppress alpha power. Beta power was only partially suppressed, whereas an increase in Lempel-Ziv complexity was observed. The relationship between plasma concentrations and effects were described using effect compartment models with sigmoidal maximum inhibitory response or maximum stimulatory response models. Values of the concentration needed to reach half of the maximum response (EC50,e) were estimated at 71, 137, and 54 nM for alpha, beta, and Lempel-Ziv complexity, respectively. A large amount of between-subject variability was associated with both beta power and Lempel-Ziv complexity with coefficients of variability of 75% and 77% for the corresponding EC50,e values, respectively. Alpha power appeared to be the most robust response, with a between-subject variability in EC50,e of 29%. Having a deeper understanding of these processes might prove beneficial in choosing appropriate doses and response biomarkers in the future clinical development of DMT.
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35.
  • Eckernäs, Emma, 1992, et al. (författare)
  • Optimized infusion rates for N,N-dimethyltryptamine to achieve a target psychedelic intensity based on a modeling and simulation framework
  • 2023
  • Ingår i: Cpt-Pharmacometrics & Systems Pharmacology. - 2163-8306. ; 12:10, s. 1398-1410
  • Tidskriftsartikel (refereegranskat)abstract
    • N,N-dimethyltryptamine (DMT) is a psychedelic compound that is being studied as a therapeutic option in various psychiatric disorders. Due to its short half-life, continuous infusion of DMT has been proposed to extend the psychedelic experience and potential therapeutic effects. The primary aim of this work was to design an infusion protocol for DMT based on a desired level of psychedelic intensity using population pharmacokinetic/pharmacodynamic modeling. As a secondary aim, the impact of choosing a continuous variable or a bounded integer pharmacokinetic/pharmacodynamic model to inform such an infusion protocol was investigated. A previously published continuous variable model and two newly developed bounded integer models were used to assess optimal doses for achieving a target response. Simulations were performed to identify an optimal combination of a bolus dose and an infusion rate. Based on the simulations, optimal doses to achieve intensity ratings between 7 and 9 (possible range = 0-10) were a bolus dose of 16 mg DMT fumarate followed by an infusion rate of 1.4 mg/min based on the continuous variable model and 14 mg with 1.2 mg/min for the two bounded integer models. However, the proportion within target was low (<53%) for all models, indicating that individual dose adjustments would be necessary. Furthermore, some differences between the models were observed. The bounded integer models generally predicted lower proportions within a target of 7-9 with higher proportions exceeding target compared with the continuous variable model. However, results varied depending on target response with the major differences observed at the boundaries of the scale.
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36.
  • Eckernäs, Emma, 1992, et al. (författare)
  • Population pharmacokinetic/pharmacodynamic modeling of the psychedelic experience induced by N,N-dimethyltryptamine - Implications for dose considerations
  • 2022
  • Ingår i: Cts-Clinical and Translational Science. - : Wiley. - 1752-8054 .- 1752-8062. ; 15:12, s. 2928-2937
  • Tidskriftsartikel (refereegranskat)abstract
    • N,N-dimethyltryptamine (DMT) is a psychedelic compound that is believed to have potential as a therapeutic option in several psychiatric disorders. The number of clinical investigations with DMT is increasing. However, very little is known about the pharmacokinetic properties of DMT as well as any relationship between its exposure and effects. This study aimed to characterize population pharmacokinetics of DMT as well as the relationship between DMT plasma concentrations and its psychedelic effects as measured through subjective intensity ratings. Data were obtained from 13 healthy subjects after intravenous administration of DMT. The data were analyzed using nonlinear mixed-effects modeling in NONMEM. DMT plasma concentrations were described by a two-compartment model with first-order elimination leading to formation of the major metabolite indole 3-acetic acid. The relationship between plasma concentrations and psychedelic intensity was described by an effect site compartment model with a sigmoid maximum effect (E-max) response. DMT clearance was estimated at 26 L/min, a high value indicating elimination of DMT to be independent of blood flow. Higher concentrations of DMT were associated with a more intense experience with the concentration of DMT at the effect site required to produce half of the maximum response estimated at 95 nM. The maximum achievable intensity rating was 10 and the simulated median maximum rating was zero, 2, 4, 8, and 9 after doses of 1, 4, 7, 14, and 20 mg, respectively. The model can be useful in predicting suitable doses for clinical investigations of DMT based on the desired intensity of the subjective experience.
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37.
  • Gonzalez-Ortiz, Fernando, et al. (författare)
  • A novel ultrasensitive assay for plasma p-tau217: Performance in individuals with subjective cognitive decline and early Alzheimer's disease.
  • 2024
  • Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - 1552-5279. ; 20:2, s. 1239-1249
  • Tidskriftsartikel (refereegranskat)abstract
    • Detection of Alzheimer's disease (AD) pathophysiology among individuals with mild cognitive changesand those experiencing subjective cognitive decline (SCD) remains challenging. Plasma phosphorylated tau 217 (p-tau217) is one of the most promising of the emerging biomarkers for AD. However, accessible methods are limited.We employed a novel p-tau217 immunoassay (University of Gothenburg [UGOT] p-tau217) in four independent cohorts (n=308) including a cerebrospinal fluid (CSF) biomarker-classified cohort (Discovery), two cohorts consisting mostly of cognitively unimpaired (CU) and mild cognitively impaired (MCI) participants (MYHAT and Pittsburgh), and a population-based cohort of individuals with SCD (Barcelonaβeta Brain Research Center's Alzheimer's At-Risk Cohort [β-AARC]).UGOT p-tau217 showed high accuracy (area under the curve [AUC]=0.80-0.91) identifying amyloid beta (Aβ) pathology, determined either by Aβ positron emission tomography or CSF Aβ42/40 ratio. In individuals experiencing SCD, UGOT p-tau217 showed high accuracy identifying those with a positive CSF Aβ42/40 ratio (AUC=0.91).UGOT p-tau217 can be an easily accessible and efficient way to screen and monitor patients with suspected AD pathophysiology, even in the early stages of the continuum.
  •  
38.
  • Gonzalez-Ortiz, Fernando, et al. (författare)
  • A novel ultrasensitive assay for plasma p-tau217: performance in individuals with subjective cognitive decline and early Alzheimer's disease.
  • 2023
  • Ingår i: medRxiv : the preprint server for health sciences.
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Detection of Alzheimer's disease (AD) pathophysiology among cognitively unimpaired individuals and those experiencing subjective cognitive decline (SCD) remains challenging. Plasma p-tau217 is one of the most promising of the emerging biomarkers for AD. However, accessible methods are limited.We employed a novel p-tau217 immunoassay (UGOT p-tau217) in four independent cohorts (n=308) including a cerebrospinal fluid (CSF) biomarker-classified cohort (Discovery), two cohorts consisting mostly of cognitively unimpaired participants (MYHAT and Pittsburgh), and a population-based cohort of individuals with SCD (β-AARC).UGOT p-tau217 showed high accuracy (AUC= 0.80-0.91) identifying Aβ pathology, determined either by Aβ positron emission tomography or CSF Aβ42/40 ratio. In individuals experiencing SCD, UGOT p-tau217 showed high accuracy identifying those with a positive CSF Aβ42/40 ratio (AUC= 0.91).UGOT p-tau217 can be an easily accessible and efficient way to screen and monitor patients with suspected AD pathophysiology, even in the early stages of the continuum.
  •  
39.
  • Hall, C. Michael, et al. (författare)
  • Second home tourism and climate change
  • 2023
  • Ingår i: Second Homes and Climate Change. - : Routledge. - 9781003091295 - 9780367549466 - 9781000905533 ; , s. 1-15
  • Bokkapitel (refereegranskat)abstract
    • The chapter provides an introduction to issues associated with the relationship between second homes and climate change. A major problem identified in existing research is the lack of consistent definitions of what constitutes a second home within and between jurisdictions, which makes comparative research difficult. Existing research is geographically limited in scope although recognition of the environmental impacts of climate change has existed for many years although research on climate change related issues is much more recent. Two major strands of research exist. The first is the contribution of second homes to climate change, which is primarily the use of transport to access second homes. Private cars are identified as the major transport mode for domestic second home tourism. The second strand of research is the impacts of climate change and climate change related events on second home destinations. The latter reflects the majority of contributions to the present work.
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40.
  • Kac, Przemyslaw R., et al. (författare)
  • Plasma p-tau212: antemortem diagnostic performance and prediction of autopsy verification of Alzheimer's disease neuropathology.
  • 2023
  • Ingår i: medRxiv : the preprint server for health sciences.
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Blood phosphorylated tau (p-tau) biomarkers, including p-tau217, show high associations with Alzheimer's disease (AD) neuropathologic change and clinical stage. Certain plasma p-tau217 assays recognize tau forms phosphorylated additionally at threonine-212, but the contribution of p-tau212 alone to AD is unknown. We developed a blood-based immunoassay that is specific to p-tau212 without cross-reactivity to p-tau217. Thereafter, we examined the diagnostic utility of plasma p-tau212. In five cohorts (n=388 participants), plasma p-tau212 showed high performances for AD diagnosis and for the detection of both amyloid and tau pathology, including at autopsy as well as in memory clinic populations. The diagnostic accuracy and fold changes of plasma p-tau212 were similar to those for p-tau217 but higher than p-tau181 and p-tau231. Immunofluorescent staining of brain tissue slices showed prominent p-tau212 reactivity in neurofibrillary tangles that co-localized with p-tau217 and p-tau202/205. These findings support plasma p-tau212 as a novel peripherally accessible biomarker of AD pathophysiology.
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41.
  • Kac, Przemyslaw R., 1995, et al. (författare)
  • Plasma p-tau212 antemortem diagnostic performance and prediction of autopsy verification of Alzheimer's disease neuropathology.
  • 2024
  • Ingår i: Nature communications. - 2041-1723. ; 15:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Blood phosphorylated tau (p-tau) biomarkers, including p-tau217, show high associations with Alzheimer's disease (AD) neuropathologic change and clinical stage. Certain plasma p-tau217 assays recognize tau forms phosphorylated additionally at threonine-212, but the contribution of p-tau212 alone to AD is unknown. We developed a blood-based immunoassay that is specific to p-tau212 without cross-reactivity to p-tau217. Here, we examined the diagnostic utility of plasma p-tau212. In five cohorts (n=388 participants), plasma p-tau212 showed high performances for AD diagnosis and for the detection of both amyloid and tau pathology, including at autopsy as well as in memory clinic populations. The diagnostic accuracy and fold changes of plasma p-tau212 were similar to those for p-tau217 but higher than p-tau181 and p-tau231. Immunofluorescent staining of brain tissue slices showed prominent p-tau212 reactivity in neurofibrillary tangles that co-localized with p-tau217 and p-tau202/205. These findings support plasma p-tau212 as a peripherally accessible biomarker of AD pathophysiology.
  •  
42.
  • Kloprogge, F., et al. (författare)
  • Artemether-lumefantrine dosing for malaria treatment in young children and pregnant women: A pharmacokinetic-pharmacodynamic meta-analysis
  • 2018
  • Ingår i: Plos Medicine. - : Public Library of Science (PLoS). - 1549-1676 .- 1549-1277. ; 15:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Background The fixed dose combination of artemether-lumefantrine (AL) is the most widely used treatment for uncomplicated Plasmodium falciparum malaria. Relatively lower cure rates and lumefantrine levels have been reported in young children and in pregnant women during their second and third trimester. The aim of this study was to investigate the pharmacokinetic and pharmacodynamic properties of lumefantrine and the pharmacokinetic properties of its metabolite, desbutyl-lumefantrine, in order to inform optimal dosing regimens in all patient populations. A search in PubMed, Embase, ClinicalTrials. gov, Google Scholar, conference proceedings, and the WorldWide Antimalarial Resistance Network (WWARN) pharmacology database identified 31 relevant clinical studies published between 1 January 1990 and 31 December 2012, with 4,546 patients in whom lumefantrine concentrations were measured. Under the auspices of WWARN, relevant individual concentration-time data, clinical covariates, and outcome data from 4,122 patients were made available and pooled for the meta-analysis. The developed lumefantrine population pharmacokinetic model was used for dose optimisation through in silico simulations. Venous plasma lumefantrine concentrations 7 days after starting standard AL treatment were 24.2% and 13.4% lower in children weighing < 15 kg and 15-25 kg, respectively, and 20.2% lower in pregnant women compared with non-pregnant adults. Lumefantrine exposure decreased with increasing pre-treatment parasitaemia, and the dose limitation on absorption of lumefantrine was substantial. Simulations using the lumefantrine pharmacokinetic model suggest that, in young children and pregnant women beyond the first trimester, lengthening the dose regimen (twice daily for 5 days) and, to a lesser extent, intensifying the frequency of dosing (3 times daily for 3 days) would be more efficacious than using higher individual doses in the current standard treatment regimen (twice daily for 3 days). The model was developed using venous plasma data from patients receiving intact tablets with fat, and evaluations of alternative dosing regimens were consequently only representative for venous plasma after administration of intact tablets with fat. The absence of artemether-dihydroartemisinin data limited the prediction of parasite killing rates and recrudescent infections. Thus, the suggested optimised dosing schedule was based on the pharmacokinetic endpoint of lumefantrine plasma exposure at day 7. Our findings suggest that revised AL dosing regimens for young children and pregnant women would improve drug exposure but would require longer or more complex schedules. These dosing regimens should be evaluated in prospective clinical studies to determine whether they would improve cure rates, demonstrate adequate safety, and thereby prolong the useful therapeutic life of this valuable antimalarial treatment.
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43.
  • Meyer, Pierre-François, et al. (författare)
  • Plasma p-tau231, p-tau181, PET Biomarkers, and Cognitive Change in Older Adults.
  • 2022
  • Ingår i: Annals of neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 91:4, s. 548-560
  • Tidskriftsartikel (refereegranskat)abstract
    • The objective of this study was to evaluate novel plasma p-tau231 and p-tau181, as well as Aβ40 and Aβ42 assays as indicators of tau and Aβ pathologies measured with positron emission tomography (PET), and their association with cognitive change, in cognitively unimpaired older adults.In a cohort of 244 older adults at risk of Alzheimer's disease (AD) owing to a family history of AD dementia, we measured single molecule array (Simoa)-based plasma tau biomarkers (p-tau231 and p-tau181), Aβ40 and Aβ42 with immunoprecipitation mass spectrometry, and Simoa neurofilament light (NfL). A subset of 129 participants underwent amyloid-β (18 F-NAV4694) and tau (18 F-flortaucipir) PET assessments. We investigated plasma biomarker associations with Aβ and tau PET at the global and voxel level and tested plasma biomarker combinations for improved detection of Aβ-PET positivity. We also investigated associations with 8-year cognitive change.Plasma p-tau biomarkers correlated with flortaucipir binding in medial temporal, parietal, and inferior temporal regions. P-tau231 showed further associations in lateral parietal and occipital cortices. Plasma Aβ42/40 explained more variance in global Aβ-PET binding than Aβ42 alone. P-tau231 also showed strong and widespread associations with cortical Aβ-PET binding. Combining Aβ42/40 with p-tau231 or p-tau181 allowed for good distinction between Aβ-negative and -positive participants (area under the receiver operating characteristic curve [AUC] range=0.81-0.86). Individuals with low plasma Aβ42/40 and high p-tau experienced faster cognitive decline.Plasma p-tau231 showed more robust associations with PET biomarkers than p-tau181 in presymptomatic individuals. The combination of p-tau and Aβ42/40 biomarkers detected early AD pathology and cognitive decline. Such markers could be used as prescreening tools to reduce the cost of prevention trials. ANN NEUROL 2022.
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44.
  • Second Homes and Climate Change
  • 2023
  • Samlingsverk (redaktörskap) (refereegranskat)abstract
    • This book is the first to address the important interrelationship between second homes and climate change, which has become an increasingly relevant issue for many regions around the world.Second homes are often a key source of tourist visitation as well as economic benefit for their host communities. The chapters provide an array of international case studies and climate change impacts, including the changing biocultural landscapes in Italy, hazard risks in the mountains of Poland, and the shifting media discussion on second homes and climate change in Finland. Topics covered focus on issues around planning and governance in second home locations, adaptation and mitigation measures implemented by second home owners, and the influence of second home owners’ place attachment in relation to second home impacts. It introduces the overall topic of second homes and climate change while also laying the groundwork for future work in this burgeoning area of research.This book will be of significant interest to upper-level undergraduates, graduate students, and academics in the fields of geography, tourism, planning, housing studies, regional development, environmental management, and disaster management. It would also be of use for professionals who engage with second home communities, particularly planners, government officials, and environmental officers.
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45.
  • Tanaka, Tomotaka, et al. (författare)
  • Head-to-head comparison of amplified plasmonic exosome Aβ42 platform and single-molecule array immunoassay in a memory clinic cohort
  • 2021
  • Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 28:5, s. 1479-1489
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose: Various blood biomarkers reflecting brain amyloid-β (Aβ) load have recently been proposed with promising results. However, to date, no comparative study amongst blood biomarkers has been reported. Our objective was to examine the diagnostic performance and cost effectiveness of three blood biomarkers on the same cohort. Methods: Using the same cohort (n = 68), the performances of the single-molecule array (Simoa) Aβ40, Aβ42, Aβ42/Aβ40 and the amplified plasmonic exosome (APEX) Aβ42 blood biomarkers were compared using amyloid positron emission tomography (PET) as the reference standard. The extent to which these blood tests can reduce the recruitment cost of clinical trials was also determined by identifying amyloid positive (Aβ+) participants. Results: Compared to Simoa biomarkers, APEX-Aβ42 showed significantly higher correlations with amyloid PET retention values and excellent diagnostic performance (sensitivity 100%, specificity 93.3%, area under the curve 0.995). When utilized for clinical trial recruitment, our simulation showed that pre-screening with blood biomarkers followed by a confirmatory amyloid PET imaging would roughly half the cost (56.8% reduction for APEX-Aβ42 and 48.6% for Simoa-Aβ42/Aβ40) compared to the situation where only PET imaging is used. Moreover, with 100% sensitivity, APEX-Aβ42 pre-screening does not increase the required number of initial participants. Conclusions: With its high diagnostic performance, APEX is an ideal candidate for Aβ+ subject identification, monitoring and primary care screening, and could efficiently enrich clinical trials with Aβ+ participants whilst halving recruitment costs.
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46.
  • Thielmann, Isabel, et al. (författare)
  • The HEXACO-100 Across 16 Languages : A Large-Scale Test of Measurement Invariance
  • 2020
  • Ingår i: Journal of Personality Assessment. - : Informa UK Limited. - 0022-3891 .- 1532-7752. ; 102:5, s. 714-726
  • Tidskriftsartikel (refereegranskat)abstract
    • The HEXACO Personality Inventory-Revised (HEXACO-PI-R) has become one of the most heavily applied measurement tools for the assessment of basic personality traits. Correspondingly, the inventory has been translated to many languages for use in cross-cultural research. However, formal tests examining whether the different language versions of the HEXACO-PI-R provide equivalent measures of the 6 personality dimensions are missing. We provide a large-scale test of measurement invariance of the 100-item version of the HEXACO-PI-R across 16 languages spoken in European and Asian countries (N = 30,484). Multigroup exploratory structural equation modeling and confirmatory factor analyses revealed consistent support for configural and metric invariance, thus implying that the factor structure of the HEXACO dimensions as well as the meaning of the latent HEXACO factors is comparable across languages. However, analyses did not show overall support for scalar invariance; that is, equivalence of facet intercepts. A complementary alignment analysis supported this pattern, but also revealed substantial heterogeneity in the level of (non)invariance across facets and factors. Overall, results imply that the HEXACO-PI-R provides largely comparable measurement of the HEXACO dimensions, although the lack of scalar invariance highlights the necessity for future research clarifying the interpretation of mean-level trait differences across countries.
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47.
  • Vos, K., et al. (författare)
  • MRP2/ABCC2 C1515Y polymorphism modulates exposure to lumefantrine during artemether-lumefantrine antimalarial therapy
  • 2017
  • Ingår i: Pharmacogenomics. - : Future Medicine Ltd. - 1462-2416 .- 1744-8042. ; 18:10, s. 981-985
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: To investigate the potential involvement of the hepatic ATP-binding cassette transporters MRP2 and MDR1 in the disposition of lumefantrine (LUM) among patients with uncomplicated Plasmodium falciparum malaria. Materials & methods: The tag SNPs MDR1/ABCB1 C3435T and MRP2/ABCC2 C1515Y were determined in two artemether-LUM clinical trials, including a pharmacokinetic/pharmacodynamic study focused on the treatment phase (72 h), and an efficacy trial where day 7 (D-7) LUM levels were measured. Results: The 1515YY genotype was significantly associated with higher (p < 0.01) LUM D-7 concentrations (median 1.42 mu M), compared with 0.77 mu M for 1515CY and 0.59 mu M for 1515CC. No significant influence of the MDR1/ABCB1 C3435T was found. Conclusion: LUM body disposition may be influenced by MRP2/ABCC2 genotype.
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