| 1. |
- Kanai, M, et al.
(author)
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- 2023
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swepub:Mat__t
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| 2. |
- Niemi, MEK, et al.
(author)
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- 2021
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swepub:Mat__t
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Appeltans, W., et al.
(author)
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The Magnitude of Global Marine Species Diversity
- 2012
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In: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 22:23, s. 2189-2202
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Journal article (peer-reviewed)abstract
- Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are similar to 226,000 eukaryotic marine species described. More species were described in the past decade (similar to 20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are similar to 170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 +/- 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.
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| 9. |
- Chen, Zhishan, et al.
(author)
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Fine-mapping analysis including over 254 000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes
- 2024
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In: Nature Communications. - : Springer Nature. - 2041-1723. ; 15:1
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Journal article (peer-reviewed)abstract
- Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development.
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| 10. |
- Furukawa, T. A., et al.
(author)
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Dismantling, optimising, and personalising internet cognitive behavioural therapy for depression: a systematic review and component network meta-analysis using individual data
- 2021
-
In: Lancet Psychiatry. - : Elsevier BV. - 2215-0374 .- 2215-0366. ; 8:6, s. 500-511
-
Journal article (peer-reviewed)abstract
- Findings We identified 76 RCTs, including 48 trials contributing individual participant data (11 704 participants) and 28 trials with aggregate data (6474 participants). The participants' weighted mean age was 42.0 years and 12 406 (71%) of 17 521 reported were women. There was suggestive evidence that behavioural activation might be beneficial (iMD -1.83 [95% credible interval (CrI) -2.90 to -0.80]) and that relaxation might be harmful (1.20 [95% CrI 0.17 to 2.27]). Baseline severity emerged as the strongest prognostic factor for endpoint depression. Combining human and automated encouragement reduced dropouts from treatment (incremental odds ratio, 0.32 [95% CrI 0.13 to 0.93]). The risk of bias was low for the randomisation process, missing outcome data, or selection of reported results in most of the included studies, uncertain for deviation from intended interventions, and high for measurement of outcomes. There was moderate to high heterogeneity among the studies and their components. 511
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| 11. |
- Huyghe, Jeroen R., et al.
(author)
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Discovery of common and rare genetic risk variants for colorectal cancer
- 2019
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In: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 51:1, s. 76-
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Journal article (peer-reviewed)abstract
- To further dissect the genetic architecture of colorectal cancer (CRC), we performed whole-genome sequencing of 1,439 cases and 720 controls, imputed discovered sequence variants and Haplotype Reference Consortium panel variants into genome-wide association study data, and tested for association in 34,869 cases and 29,051 controls. Findings were followed up in an additional 23,262 cases and 38,296 controls. We discovered a strongly protective 0.3% frequency variant signal at CHD1. In a combined meta-analysis of 125,478 individuals, we identified 40 new independent signals at P < 5 x 10(-8), bringing the number of known independent signals for CRC to similar to 100. New signals implicate lower-frequency variants, Kruppel-like factors, Hedgehog signaling, Hippo-YAP signaling, long noncoding RNAs and somatic drivers, and support a role for immune function. Heritability analyses suggest that CRC risk is highly polygenic, and larger, more comprehensive studies enabling rare variant analysis will improve understanding of biology underlying this risk and influence personalized screening strategies and drug development.
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| 12. |
- Das, A., et al.
(author)
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Genomic predictors of response to PD-1 inhibition in children with germline DNA replication repair deficiency
- 2022
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In: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 28:1, s. 125-135
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Journal article (peer-reviewed)abstract
- Cancers arising from germline DNA mismatch repair deficiency or polymerase proofreading deficiency (MMRD and PPD) in children harbour the highest mutational and microsatellite insertion–deletion (MS-indel) burden in humans. MMRD and PPD cancers are commonly lethal due to the inherent resistance to chemo-irradiation. Although immune checkpoint inhibitors (ICIs) have failed to benefit children in previous studies, we hypothesized that hypermutation caused by MMRD and PPD will improve outcomes following ICI treatment in these patients. Using an international consortium registry study, we report on the ICI treatment of 45 progressive or recurrent tumors from 38 patients. Durable objective responses were observed in most patients, culminating in a 3 year survival of 41.4%. High mutation burden predicted response for ultra-hypermutant cancers (>100 mutations per Mb) enriched for combined MMRD + PPD, while MS-indels predicted response in MMRD tumors with lower mutation burden (10–100 mutations per Mb). Furthermore, both mechanisms were associated with increased immune infiltration even in ‘immunologically cold’ tumors such as gliomas, contributing to the favorable response. Pseudo-progression (flare) was common and was associated with immune activation in the tumor microenvironment and systemically. Furthermore, patients with flare who continued ICI treatment achieved durable responses. This study demonstrates improved survival for patients with tumors not previously known to respond to ICI treatment, including central nervous system and synchronous cancers, and identifies the dual roles of mutation burden and MS-indels in predicting sustained response to immunotherapy. © 2022, The Author(s).
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| 13. |
- Amos, Christopher I, et al.
(author)
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Genome-wide association study identifies novel loci predisposing to cutaneous melanoma
- 2011
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 20:24, s. 23-5012
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Journal article (peer-reviewed)abstract
- We performed a multistage genome-wide association study of melanoma. In a discovery cohort of 1804 melanoma cases and 1026 controls, we identified loci at chromosomes 15q13.1 (HERC2/OCA2 region) and 16q24.3 (MC1R) regions that reached genome-wide significance within this study and also found strong evidence for genetic effects on susceptibility to melanoma from markers on chromosome 9p21.3 in the p16/ARF region and on chromosome 1q21.3 (ARNT/LASS2/ANXA9 region). The most significant single-nucleotide polymorphisms (SNPs) in the 15q13.1 locus (rs1129038 and rs12913832) lie within a genomic region that has profound effects on eye and skin color; notably, 50% of variability in eye color is associated with variation in the SNP rs12913832. Because eye and skin colors vary across European populations, we further evaluated the associations of the significant SNPs after carefully adjusting for European substructure. We also evaluated the top 10 most significant SNPs by using data from three other genome-wide scans. Additional in silico data provided replication of the findings from the most significant region on chromosome 1q21.3 rs7412746 (P = 6 × 10(-10)). Together, these data identified several candidate genes for additional studies to identify causal variants predisposing to increased risk for developing melanoma.
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| 14. |
- Arneth, A., et al.
(author)
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Historical carbon dioxide emissions caused by land-use changes are possibly larger than assumed
- 2017
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In: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 10:2, s. 79-84
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Research review (peer-reviewed)abstract
- The terrestrial biosphere absorbs about 20% of fossil-fuel CO 2 emissions. The overall magnitude of this sink is constrained by the difference between emissions, the rate of increase in atmospheric CO 2 concentrations, and the ocean sink. However, the land sink is actually composed of two largely counteracting fluxes that are poorly quantified: fluxes from land-use change and CO 2 uptake by terrestrial ecosystems. Dynamic global vegetation model simulations suggest that CO 2 emissions from land-use change have been substantially underestimated because processes such as tree harvesting and land clearing from shifting cultivation have not been considered. As the overall terrestrial sink is constrained, a larger net flux as a result of land-use change implies that terrestrial uptake of CO 2 is also larger, and that terrestrial ecosystems might have greater potential to sequester carbon in the future. Consequently, reforestation projects and efforts to avoid further deforestation could represent important mitigation pathways, with co-benefits for biodiversity. It is unclear whether a larger land carbon sink can be reconciled with our current understanding of terrestrial carbon cycling. Our possible underestimation of the historical residual terrestrial carbon sink adds further uncertainty to our capacity to predict the future of terrestrial carbon uptake and losses.
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| 15. |
- Bowden, John A., et al.
(author)
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Harmonizing lipidomics : NIST interlaboratory comparison exercise for lipidomics using SRM 1950-Metabolites in Frozen Human Plasma
- 2017
-
In: Journal of Lipid Research. - 0022-2275 .- 1539-7262. ; 58:12, s. 2275-2288
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Journal article (peer-reviewed)abstract
- As the lipidomics field continues to advance, self-evaluation within the community is critical. Here, we performed an interlaboratory comparison exercise for lipidomics using Standard Reference Material (SRM) 1950-Metabolites in Frozen Human Plasma, a commercially available reference material. The interlaboratory study comprised 31 diverse laboratories, with each laboratory using a different lipidomics workflow. A total of 1,527 unique lipids were measured across all laboratories and consensus location estimates and associated uncertainties were determined for 339 of these lipids measured at the sum composition level by five or more participating laboratories. These evaluated lipids detected in SRM 1950 serve as community-wide benchmarks for intra-and interlaboratory quality control and method validation. These analyses were performed using nonstandardized laboratory-independent workflows. The consensus locations were also compared with a previous examination of SRM 1950 by the LIPID MAPS consortium.jlr While the central theme of the interlaboratory study was to provide values to help harmonize lipids, lipid mediators, and precursor measurements across the community, it was also initiated to stimulate a discussion regarding areas in need of improvement.
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| 16. |
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| 17. |
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| 18. |
- Das, Anirban, et al.
(author)
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Combined immunotherapy improves outcome for replication repair deficient (RRD) high-grade glioma failing anti-PD1 monotherapy: A report from the International RRD Consortium.
- 2024
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In: Cancer discovery. - 2159-8290. ; 14:2, s. 258-273
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Journal article (peer-reviewed)abstract
- Immune-checkpoint inhibition (ICI) is effective for replication-repair deficient, high-grade gliomas (RRD-HGG). Clinical/biologic impact of immune-directed approaches after failing ICI-monotherapy are unknown. We performed an international study on 75 patients treated with anti-PD1; 20 are progression-free (median follow-up: 3.7-years). After 2nd-progression/recurrence (n=55), continuing ICI-based salvage prolonged survival to 11.6-months (n=38; p<0.001), particularly for those with extreme mutation burden (p=0.03). Delayed, sustained responses were observed, associated with changes in mutational spectra and immune-microenvironment. Response to re-irradiation was explained by an absence of deleterious post-radiation indel signatures (ID8). Increased CTLA4-expression over time, and subsequent CTLA4-inhibition resulted in response/stable disease in 75%. RAS-MAPK-pathway inhibition led to reinvigoration of peripheral immune and radiological responses. Local (flare) and systemic immune adverse events were frequent (biallelic mismatch-repair deficiency > Lynch syndrome). We provide mechanistic rationale for the sustained benefit in RRD-HGG from immune-directed/ synergistic salvage therapies. Future approaches need to be tailored to patient and tumor biology.
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| 19. |
- Jung, Christian, et al.
(author)
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A comparison of very old patients admitted to intensive care unit after acute versus elective surgery or intervention
- 2019
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In: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 52, s. 141-148
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Journal article (peer-reviewed)abstract
- Background: We aimed to evaluate differences in outcome between patients admitted to intensive care unit (ICU) after elective versus acute surgery in a multinational cohort of very old patients (80 years; VIP). Predictors of mortality, with special emphasis on frailty, were assessed.Methods: In total, 5063 VIPs were induded in this analysis, 922 were admitted after elective surgery or intervention, 4141 acutely, with 402 after acute surgery. Differences were calculated using Mann-Whitney-U test and Wilcoxon test. Univariate and multivariable logistic regression were used to assess associations with mortality.Results: Compared patients admitted after acute surgery, patients admitted after elective surgery suffered less often from frailty as defined as CFS (28% vs 46%; p < 0.001), evidenced lower SOFA scores (4 +/- 5 vs 7 +/- 7; p < 0.001). Presence of frailty (CFS >4) was associated with significantly increased mortality both in elective surgery patients (7% vs 12%; p = 0.01), in acute surgery (7% vs 12%; p = 0.02).Conclusions: VIPs admitted to ICU after elective surgery evidenced favorable outcome over patients after acute surgery even after correction for relevant confounders. Frailty might be used to guide clinicians in risk stratification in both patients admitted after elective and acute surgery.
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| 20. |
- Kanzler, Kathryn E, et al.
(author)
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Mitigating the Effect of Pain Severity on Activity and Disability in Patients with Chronic Pain : The Crucial Context of Acceptance.
- 2018
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In: Pain medicine (Malden, Mass.). - : Oxford University Press (OUP). - 1526-2375 .- 1526-4637.
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Journal article (peer-reviewed)abstract
- Objective: The purpose of this study was to examine the effect of pain severity on activity levels and physical disability in the context of high pain acceptance. We hypothesized that pain acceptance moderates the effect of pain severity on general activity and physical disability, such that at higher levels of acceptance, the deleterious effect of pain is mitigated.Methods: Two hundred seven patients with chronic pain were recruited from three clinics in a large southwestern military treatment facility. Participants completed an anonymous self-report battery of standardized measures, including the Chronic Pain Acceptance Questionnaire, modified Oswestry Disability Index, and Pain Severity and General Activity subscales of the West Haven-Yale Multidimensional Pain Inventory.Results: Chronic pain acceptance was found to significantly moderate relations between pain severity and general activity (b = 0.0061, t(198) = 2.75, P = 0.007, 95% confidence interval [CI] = 0.002 to 0.011) and pain severity and disability (b = 0.036, t(193) = -2.564, P = 0.011, 95% CI = -0.063 to -0.008). In the context of higher acceptance, the negative effect of pain on activity and disability appeared reduced. Conversely, in the context of low acceptance, the effect of pain on disability appeared accentuated at all levels of pain severity.Conclusions: Higher acceptance mitigated both activity level and disability in a military-affiliated clinical sample of patients with chronic pain. Results further establish the role of acceptance in relation to functioning in a unique sample of people with chronic pain. These findings have implications for understanding and enhancing functioning in chronic pain populations.
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| 21. |
- Martins, Inês S., et al.
(author)
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Widespread shifts in body size within populations and assemblages
- 2023
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In: Science. - 0036-8075 .- 1095-9203. ; 381:6662, s. 1067-1071
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Journal article (peer-reviewed)abstract
- Biotic responses to global change include directional shifts in organismal traits. Body size, an integrative trait that determines demographic rates and ecosystem functions, is thought to be shrinking in the Anthropocene. Here, we assessed the prevalence of body size change in six taxon groups across 5025 assemblage time series spanning 1960 to 2020. Using the Price equation to partition this change into within-species body size versus compositional changes, we detected prevailing decreases in body size through time driven primarily by fish, with more variable patterns in other taxa. We found that change in assemblage composition contributes more to body size changes than within-species trends, but both components show substantial variation in magnitude and direction. The biomass of assemblages remains quite stable as decreases in body size trade off with increases in abundance.
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| 22. |
- Papastefanou, Phillip, et al.
(author)
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A Dynamic Model for Strategies and Dynamics of Plant Water-Potential Regulation Under Drought Conditions
- 2020
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In: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 11
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Journal article (peer-reviewed)abstract
- Vegetation responds to drought through a complex interplay of plant hydraulic mechanisms, posing challenges for model development and parameterization. We present a mathematical model that describes the dynamics of leaf water-potential over time while considering different strategies by which plant species regulate their water-potentials. The model has two parameters: the parameter λ describing the adjustment of the leaf water potential to changes in soil water potential, and the parameter Δψww describing the typical ‘well-watered’ leaf water potentials at non-stressed (near-zero) levels of soil water potential. Our model was tested and calibrated on 110 time-series datasets containing the leaf- and soil water potentials of 66 species under drought and non-drought conditions. Our model successfully reproduces the measured leaf water potentials over time based on three different regulation strategies under drought. We found that three parameter sets derived from the measurement data reproduced the dynamics of 53% of an drought dataset, and 52% of a control dataset [root mean square error (RMSE) < 0.5 MPa)]. We conclude that, instead of quantifying water-potential-regulation of different plant species by complex modeling approaches, a small set of parameters may be sufficient to describe the water potential regulation behavior for large-scale modeling. Thus, our approach paves the way for a parsimonious representation of the full spectrum of plant hydraulic responses to drought in dynamic vegetation models.
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| 23. |
- Toreti, A, et al.
(author)
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Narrowing uncertainties in the effects of elevated CO2 on crops
- 2020
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In: Nature Food. - : Springer Science and Business Media LLC. - 2662-1355. ; 1, s. 775-782
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Journal article (peer-reviewed)abstract
- Plant responses to rising atmospheric carbon dioxide (CO2) concentrations, together with projected variations in temperature and precipitation will determine future agricultural production. Estimates of the impacts of climate change on agriculture provide essential information to design effective adaptation strategies, and develop sustainable food systems. Here, we review the current experimental evidence and crop models on the effects of elevated CO2 concentrations. Recent concerted efforts have narrowed the uncertainties in CO2-induced crop responses so that climate change impact simulations omitting CO2 can now be eliminated. To address remaining knowledge gaps and uncertainties in estimating the effects of elevated CO2 and climate change on crops, future research should expand experiments on more crop species under a wider range of growing conditions, improve the representation of responses to climate extremes in crop models, and simulate additional crop physiological processes related to nutritional quality.
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| 24. |
- Adam, J., et al.
(author)
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Fumarate Hydratase Deletion in Pancreatic beta Cells Leads to Progressive Diabetes
- 2017
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In: Cell Reports. - : Elsevier BV. - 2211-1247. ; 20:13, s. 3135-3148
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Journal article (peer-reviewed)abstract
- We explored the role of the Krebs cycle enzyme fumarate hydratase (FH) in glucose-stimulated insulin secretion (GSIS). Mice lacking Fh1 in pancreatic beta cells (Fh1 beta KO mice) appear normal for 6-8 weeks but then develop progressive glucose intolerance and diabetes. Glucose tolerance is rescued by expression of mitochondrial or cytosolic FH but not by deletion of Hif1 alpha or Nrf2. Progressive hyperglycemia in Fh1bKO mice led to dysregulated metabolism in b cells, a decrease in glucose-induced ATP production, electrical activity, cytoplasmic [Ca2+](i) elevation, and GSIS. Fh1 loss resulted in elevated intracellular fumarate, promoting succination of critical cysteines in GAPDH, GMPR, and PARK 7/DJ-1 and cytoplasmic acidification. Intracellular fumarate levels were increased in islets exposed to high glucose and in islets from human donors with type 2 diabetes (T2D). The impaired GSIS in islets from diabetic Fh1bKO mice was ameliorated after culture under normoglycemic conditions. These studies highlight the role of FH and dysregulated mitochondrial metabolism in T2D.
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| 25. |
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| 26. |
- Cordeddu, Viviana, et al.
(author)
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Activating Mutations Affecting the Dbl Homology Domain of SOS2 Cause Noonan Syndrome
- 2015
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In: Human Mutation. - : WILEY-BLACKWELL. - 1059-7794 .- 1098-1004. ; 36:11, s. 1080-1087
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Journal article (peer-reviewed)abstract
- The RASopathies constitute a family of autosomal-dominant disorders whose major features include facial dysmorphism, cardiac defects, reduced postnatal growth, variable cognitive deficits, ectodermal and skeletal anomalies, and susceptibility to certain malignancies. Noonan syndrome (NS), the commonest RASopathy, is genetically heterogeneous and caused by functional dysregulation of signal transducers and regulatory proteins with roles in the RAS/extracellular signal-regulated kinase (ERK) signal transduction pathway. Mutations in known disease genes account for approximately 80% of affected individuals. Here, we report that missense mutations altering Son of Sevenless, Drosophila, homolog 2 (SOS2), which encodes a RAS guanine nucleotide exchange factor, occur in a small percentage of subjects with NS. Four missense mutations were identified in five unrelated sporadic cases and families transmitting NS. Disease-causing mutations affected three conserved residues located in the Dbl homology (DH) domain, of which two are directly involved in the intramolecular binding network maintaining SOS2 in its autoinhibited conformation. All mutations were found to promote enhanced signaling from RAS to ERK. Similar to NS-causing SOS1 mutations, the phenotype associated with SOS2 defects is characterized by normal development and growth, as well as marked ectodermal involvement. Unlike SOS1 mutations, however, those in SOS2 are restricted to the DH domain.
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| 27. |
- Dams-O'Connor, K., et al.
(author)
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Alzheimer's Disease-Related Dementias Summit 2022: National Research Priorities for the Investigation of Post-Traumatic Brain Injury Alzheimer's Disease and Related Dementias
- 2023
-
In: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 40:15-16, s. 1512-1523
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Journal article (peer-reviewed)abstract
- Traumatic Brain Injury (TBI) is a risk factor for Alzheimer's disease and Alzheimer's disease related dementias (AD/ADRD) and otherwise classified post-traumatic neurodegeneration (PTND). Targeted research is needed to elucidate the circumstances and mechanisms through which TBI contributes to the initiation, development, and progression of AD/ADRD pathologies including multiple etiology dementia (MED). The National Institutes of Health hosts triennial ADRD summits to inform a national research agenda, and TBI was included for a second time in 2022. A multidisciplinary expert panel of TBI and dementia researchers was convened to re-evaluate the 2019 research recommendations for understanding TBI as an AD/ADRD risk factor and to assess current progress and research gaps in understanding post-TBI AD/ADRD. Refined and new recommendations were presented during the MED special topic session at the virtual ADRD Summit in March 2022. Final research recommendations incorporating broad stakeholder input are organized into four priority areas as follows: (1) Promote interdisciplinary collaboration and data harmonization to accelerate progress of rigorous, clinically meaningful research; (2) Characterize clinical and biological phenotypes of PTND associated with varied lifetime TBI histories in diverse populations to validate multimodal biomarkers; (3) Establish and enrich infrastructure to support multimodal longitudinal studies of individuals with varied TBI exposure histories and standardized methods including common data elements (CDEs) for ante-mortem and post-mortem clinical and neuropathological characterization; and (4) Support basic and translational research to elucidate mechanistic pathways, development, progression, and clinical manifestations of post-TBI AD/ADRDs. Recommendations conceptualize TBI as a contributor to MED and emphasize the unique opportunity to study AD/ADRD following known exposure, to inform disease mechanisms and treatment targets for shared common AD/ADRD pathways.
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| 28. |
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| 29. |
- Furukawa, Toshi A., et al.
(author)
-
Dismantling, optimising, and personalising internet cognitive behavioural therapy for depression : a systematic review and component network meta-analysis using individual data
- 2021
-
In: Lancet psychiatry. - London, United Kingdom : Elsevier. - 2215-0374 .- 2215-0366. ; 8:6, s. 500-511
-
Research review (peer-reviewed)abstract
- Findings We identified 76 RCTs, including 48 trials contributing individual participant data (11 704 participants) and 28 trials with aggregate data (6474 participants). The participants' weighted mean age was 42.0 years and 12 406 (71%) of 17 521 reported were women. There was suggestive evidence that behavioural activation might be beneficial (iMD -1.83 [95% credible interval (CrI) -2.90 to -0.80]) and that relaxation might be harmful (1.20 [95% CrI 0.17 to 2.27]). Baseline severity emerged as the strongest prognostic factor for endpoint depression. Combining human and automated encouragement reduced dropouts from treatment (incremental odds ratio, 0.32 [95% CrI 0.13 to 0.93]). The risk of bias was low for the randomisation process, missing outcome data, or selection of reported results in most of the included studies, uncertain for deviation from intended interventions, and high for measurement of outcomes. There was moderate to high heterogeneity among the studies and their components. 511
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| 30. |
- Hesser, Hugo, et al.
(author)
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Predicting Response to Therapist-Assisted Internet-Delivered Cognitive Behavior Therapy for Depression or Anxiety Within an Open Dissemination Trial
- 2016
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In: Behavior Therapy. - : Elsevier. - 0005-7894 .- 1878-1888. ; 47:2, s. 155-165
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Journal article (peer-reviewed)abstract
- Therapist-assisted Internet-delivered cognitive behavior therapy (ICBT) is efficacious for treating anxiety and depression, but predictors of response to treatment when delivered in clinical practice are not well understood. In this study, we explored demographic, clinical, and program variables that predicted modules started and symptom improvement (i.e., Generalized Anxiety Disorder-7 or Patient Health Questionnaire-9 total scores over pre-, mid-, and posttreatment) within a previously published open dissemination trial (Hadjistavropoulos et al., 2014). The sample consisted of 195 patients offered 12 modules of therapist-assisted ICBT for depression or generalized anxiety; ICBT was delivered by therapists working in six geographically dispersed clinics. Consistent across ICBT for depression or generalized anxiety, starting fewer modules was associated with more phone calls from therapists reflecting that therapists tended to call patients who did not start modules as scheduled. Also consistent for both ICBT programs, greater pretreatment condition severity and completion of more modules was associated with superior ICBT-derived benefit. Other predictors of response to treatment varied across the two programs. Younger age, lower education, taking psychotropic medication, being in receipt of psychiatric care and lower comfort with written communication were associated with either fewer program starts or lower symptom improvement in one of the two programs. It is concluded that monitoring response to ICBT may be particularly important in patients with these characteristics. Research directions for identifying patients who are less likely to benefit from ICBT are discussed.
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| 31. |
- Hesser, Hugo, et al.
(author)
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Therapeutic Alliance in Internet-Delivered Cognitive Behaviour Therapy for Depression or Generalized Anxiety
- 2017
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In: Clinical Psychology and Psychotherapy. - : John Wiley & Sons. - 1063-3995 .- 1099-0879. ; 24:2, s. 451-461
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Journal article (peer-reviewed)abstract
- There has been limited research on therapeutic alliance in the context of therapist-assisted Internet-delivered cognitive behaviour therapy (ICBT) when delivered in clinical practice. The present study investigated therapeutic alliance in ICBT delivered to patients seeking treatment for symptoms of depression (n=83) or generalized anxiety (n=112) as part of an open dissemination trial. ICBT was provided by 27 registered therapists or 28 graduate students working in six geographically dispersed clinics; therapist-assistance was delivered primarily through secure messages and occasionally telephone calls. The Generalized Anxiety Disorder-7 and Patient Health Questionnaire-9 were collected pre-, mid- and post-treatment, and the Therapeutic Alliance Questionnaire was assessed mid- and post-treatment. Therapeutic alliance ratings were high both at mid-treatment and post-treatment (above 80%). There was no relationship between therapeutic alliance ratings and improvement on primary outcomes. Among patients treated for depression, lower ratings of mid-treatment alliance were associated with concurrent treatment by a psychiatrist and fewer phone calls and emails from their therapist. Among patients treated for generalized anxiety, ratings of mid-treatment alliance were higher among registered providers as compared to graduate students. Multiple directions for future research on therapeutic alliance in ICBT are offered, including suggestions for developing a new measure of therapeutic alliance specific to ICBT and measuring therapeutic alliance throughout the treatment process.
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| 32. |
- Hesser, Hugo, et al.
(author)
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Therapist-assisted Internet-delivered cognitive behavior therapy for depression and anxiety : Translating evidence into clinical practice
- 2014
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In: Journal of Anxiety Disorders. - : Elsevier. - 0887-6185 .- 1873-7897. ; 28:8, s. 884-893
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Journal article (peer-reviewed)abstract
- This dissemination study examined the effectiveness of therapist-assisted Internet-delivered Cognitive Behavior Therapy (ICBT) when offered in clinical practice. A centralized unit screened and coordinated ICBT delivered by newly trained therapists working in six geographically dispersed clinical settings. Using an open trial design, 221 patients were offered 12 modules of ICBT for symptoms of generalized anxiety (n=112), depression (n=83), or panic (n=26). At baseline, midpoint and post-treatment, kpatients completed self-report measures. On average, patients completed 8 of 12 modules. Latent growth curve modeling identified significant reductions in depression, anxiety, stress and impairment (d=.65-.78), and improvements in quality of life (d=.48-.66). Improvements in primary symptoms were large (d=.91-1.25). Overall, therapist-assisted ICBT was effective when coordinated across settings in clinical practice, but further attention should be given to strategies to improve completion of treatment modules.
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| 33. |
- Kondo, Masayuki, et al.
(author)
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Are Land-Use Change Emissions in Southeast Asia Decreasing or Increasing?
- 2022
-
In: Global Biogeochemical Cycles. - 0886-6236. ; 36:1
-
Journal article (peer-reviewed)abstract
- Southeast Asia is a region known for active land-use changes (LUC) over the past 60 years; yet, how trends in net CO2 uptake and release resulting from LUC activities (net LUC flux) have changed through past decades remains uncertain. The level of uncertainty in net LUC flux from process-based models is so high that it cannot be concluded that newer estimates are necessarily more reliable than older ones. Here, we examined net LUC flux estimates of Southeast Asia for the 1980s−2010s from older and newer sets of Dynamic Global Vegetation Model simulations (TRENDY v2 and v7, respectively), and forcing data used for running those simulations, along with two book-keeping estimates (H&N and BLUE). These estimates yielded two contrasting historical LUC transitions, such that TRENDY v2 and H&N showed a transition from increased emissions from the 1980s to 1990s to declining emissions in the 2000s, while TRENDY v7 and BLUE showed the opposite transition. We found that these contrasting transitions originated in the update of LUC forcing data, which reduced the loss of forest area during the 1990s. Further evaluation of remote sensing studies, atmospheric inversions, and the history of forestry and environmental policies in Southeast Asia supported the occurrence of peak emissions in the 1990s and declining thereafter. However, whether LUC emissions continue to decline in Southeast Asia remains uncertain as key processes in recent years, such as conversion of peat forest to oil-palm plantation, are yet to be represented in the forcing data, suggesting a need for further revision.
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| 34. |
- Krysko, O, et al.
(author)
-
Severity of SARS-CoV-2 infection is associated with high numbers of alveolar mast cells and their degranulation
- 2022
-
In: Frontiers in immunology. - : Frontiers Media SA. - 1664-3224. ; 13, s. 968981-
-
Journal article (peer-reviewed)abstract
- The systemic inflammatory response post-SARS-CoV-2 infection increases pro-inflammatory cytokine production, multi-organ damage, and mortality rates. Mast cells (MC) modulate thrombo-inflammatory disease progression (e.g., deep vein thrombosis) and the inflammatory response post-infection.ObjectiveTo enhance our understanding of the contribution of MC and their proteases in SARS-CoV-2 infection and the pathogenesis of the disease, which might help to identify novel therapeutic targets.MethodsMC proteases chymase (CMA1), carboxypeptidase A3 (CPA3), and tryptase beta 2 (TPSB2), as well as cytokine levels, were measured in the serum of 60 patients with SARS-CoV-2 infection (30 moderate and 30 severe; severity of the disease assessed by chest CT) and 17 healthy controls by ELISA. MC number and degranulation were quantified by immunofluorescent staining for tryptase in lung autopsies of patients deceased from either SARS-CoV-2 infection or unrelated reasons (control). Immortalized human FcεR1+c-Kit+ LUVA MC were infected with SARS-CoV-2, or treated with its viral proteins, to assess direct MC activation by flow cytometry.ResultsThe levels of all three proteases were increased in the serum of patients with COVID-19, and strongly correlated with clinical severity. The density of degranulated MC in COVID-19 lung autopsies was increased compared to control lungs. The total number of released granules and the number of granules per each MC were elevated and positively correlated with von Willebrand factor levels in the lung. SARS-CoV-2 or its viral proteins spike and nucleocapsid did not induce activation or degranulation of LUVA MC in vitro.ConclusionIn this study, we demonstrate that SARS-CoV-2 is strongly associated with activation of MC, which likely occurs indirectly, driven by the inflammatory response. The results suggest that plasma MC protease levels could predict the disease course, and that severe COVID-19 patients might benefit from including MC-stabilizing drugs in the treatment scheme.
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| 35. |
- Li, Wei, et al.
(author)
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Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations
- 2017
-
In: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 14:22, s. 5053-5067
-
Journal article (peer-reviewed)abstract
- The use of dynamic global vegetation models (DGVMs) to estimate CO2 emissions from land-use and land-cover change (LULCC) offers a new window to account for spatial and temporal details of emissions and for ecosystem processes affected by LULCC. One drawback of LULCC emissions from DGVMs, however, is lack of observation constraint. Here, we propose a new method of using satellite-and inventory-based biomass observations to constrain historical cumulative LULCC emissions (E-LUC(c)) from an ensemble of nine DGVMs based on emerging relationships between simulated vegetation biomass and E-LUC(c). This method is applicable on the global and regional scale. The original DGVM estimates of E-LUC(c) range from 94 to 273 PgC during 1901-2012. After constraining by current biomass observations, we derive a best estimate of 155 +/- 50 PgC (1 sigma Gaussian error). The constrained LULCC emissions are higher than prior DGVM values in tropical regions but significantly lower in North America. Our emergent constraint approach independently verifies the median model estimate by biomass observations, giving support to the use of this estimate in carbon budget assessments. The uncertainty in the constrained Ec LUC is still relatively large because of the uncertainty in the biomass observations, and thus reduced uncertainty in addition to increased accuracy in biomass observations in the future will help improve the constraint. This constraint method can also be applied to evaluate the impact of land-based mitigation activities.
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| 36. |
- Manev, E, et al.
(author)
-
Frother/collector interactions in thin froth films and flotation
- 1993
-
In: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 70, s. 289-295
-
Journal article (peer-reviewed)abstract
- Thin aqueous equilibrium film studies and surface tension measurements on a mixed surfactant system consisting of polyethylene oxide (a model frother) and potassium ethyl xanthate (a model collector) enable the interaction between the two surfactants at the air/solution interface to be elucidated. For the film containing the non-ionic frother, the interface was charged and addition of low concentrations of xanthate acted as a common electrolyte and reduced the thickness of the film inducing rupture. However, at high xanthate collector concentrations, the negative charge xanthate was found to interact with the non-ionic and caused a buildup of negative charge at the air/solution. Higher frother concentrations were necessary to produce non-rupturing thin films upon increasing the xanthate concentration.
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| 37. |
- Manev, E, et al.
(author)
-
The influence of tetraalkylammonium counterions on the drainage and stability of thin films and foams stabilized by dilute aqueous solutions of sodium dodecyl sulphate
- 1997
-
In: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 186, s. 493-497
-
Journal article (peer-reviewed)abstract
- It was demonstrated that the presence of tetraalkylammonium counterions in aqueous foams and thin film lamella stabilized by sodium dodecyl sulphate (at concentrations below the cmc) can either act to promote or prevent foam stability. The increase in stability is caused by the congenial incorporation of the smaller and more hydrophilic counterions such as tetraethyl ammonium cations and to some extent tetrabutyl ammonium cations into the interfacial anionic layers. This causes regular thin film drainage rates and promotes black films and stable foams. The structure changes increase the interfacial cohesive interaction and resiliency within the thin film lamella. The decrease in stability is associated with rapid drainage rates and is caused by the penetration of larger more hydrophobic tetrapentylammonium cations in the layers. This disrupts and weakens the molecular interactions (less cohesion). This result is quite different from previously reported studies (1) describing with the action of tetraalkylammonium counterions on sodium dodecyl sulphate (at concentrations above the cmc). At these higher surfactant concentrations, a defoaming action was generally observed and could be explained in terms of a reduction in the dynamic stability (Gibbs surface elasticity).
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| 38. |
- Poptoshev, E, et al.
(author)
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Influence of surface aging on the drainage of foam films stabilized by aqueous solutions of ethyl hydroxyethyl cellulose
- 1997
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In: Langmuir. - 0743-7463 .- 1520-5827. ; 13, s. 3905-3908
-
Journal article (peer-reviewed)abstract
- The drainage times of microscopic horizontal foam films stabilised by dilute aqueous solutions of ethyl (hydroxyethyl) cellulose (EHEC) was shown to be dependent on the ageing effects (conformation changes of the adsorbed macromolecules) occuring in the freshly creates air/solution interface. At low polymer concentration (5 ppm), the films drained fairly rapidly from thickeness of about 400 to 300 nm with drainage times about 5 to 6 times greater than theoretical values calculated using the Reynolds equation. However, at higher polymer concentrations (100 ppm) at extended surface ageing (15 to 180 minutes) the films drainage times were shown to increase drastically giving values 50 times greater than theoretical values. Although these ageing effects could not be directly related to surface tension data, diffusion coefficient were calculated from interfacial tension profiles using classical diffusion theory. As the concentration of polymer increased, the diffusion coefficient were shown to decrease and were considerably smaller than previously reported experimentally values determined in bulk solution by NMR. This difference between experimental and theoretical results endorsed a kinetic rather than a diffusion or mass transport model for the transfer of EHEC molecules to the interface. The increase in drainage times with extended ageing times could be explained by the gradual formation of a steric energy barrier caused by configuration changes of the adsorbed polymer. This propably involved the progressive extension of the EHEC tails into the aqueous phase increasing the disjoining pressure, decreasing the drainage rate and producing thick stable films.
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| 39. |
- Pugh, RJ, et al.
(author)
-
A fundamental study of mica flotation in dodecylamine collector
- 1995
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In: Progress in Colloid and Polymer Science. - 0340-255X .- 1437-8027. ; 98, s. 284-287
-
Journal article (peer-reviewed)abstract
- The batch flotation response of mica in dodecylamine solution was related to foam film experiments where the stability, thickness, and interfacial potentials at the air/dodecylamine solution interface was determined. These results were compared with surface force data (reported in an earlier publication) in which hydrophobic adhesion (pull-off force), adsorbed film thickness, and the interaction between molecularly smooth mica sheets in the amine collector solution was determined. The data covered a range of pH values. Maximum flotation occurred at pH 8 and correlated to a tightly packed hydrophobio collector monolayer giving maximum hydrophobicity to the mica surface. From extended DLVO theory, it was shown that heterocoagulation between the bubble and the mica could only occur providing there was a very long range hydrophobic interaction force to counterbalance the repulsive van der Waals and electrostatic forces.
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| 40. |
- Pugh, RJ, et al.
(author)
-
Non-ionic surfactant monolayers
- 1995
-
In: Tenside Surfactants Detergents. - 0932-3414 .- 2195-8564. ; 32, s. 278-284
-
Journal article (peer-reviewed)abstract
- The foam stability of aqueous solutions of pentaethylene glycol n-decyl ether and pentaethylene glycol n-dodecyl ether surfactants was related to experimental studies carried out on thin horizontal microscopic single films of the surfactant solutions using the microinterferometric film apparatus developed by Scheludko [1]. It was observed that an initial decrease in film thickness and reduction in potential at the air/solution interface of the film, occurred at a critical surfactant concentration where "black spots" appeared in the film when it was observed in reflected light. The black spots appeared to expand and coalesce, until the entire sheet was thinned down to a metastable common black film. In addition, a sharp increase in foam stability occured above this surfactant concentration, which was about 0.1 c. m. c, and corresponded to a high surface adsorption density of surfactant. We believe that the cause of the phenomenon was a change in state of the surfactant monolayer as originally proposed by Scheludko and Exerowa [2, 3]. Such a change (condensation) from gaseous to liquid expanded monolayers, has already been established for ionic surfactants and may change the rheological properties of the adsorbed film, enhancing the foam stability. Finally, the foam stability was determined at a range of electrolyte (KCI) concentrations from which it could be suggested that two types offoam stabilization methods were operating In the low electrolyte concentration, the stability appeared to be controlled by the metastable common first black film, but at high electrolyte concentrations the stability seemed to be dependent on secondary "Newton black" films
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| 41. |
- Pugh, T. A M, et al.
(author)
-
Climate analogues suggest limited potential for intensification of production on current croplands under climate change
- 2016
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
-
Journal article (peer-reviewed)abstract
- Climate change could pose a major challenge to efforts towards strongly increase food production over the coming decades. However, model simulations of future climate-impacts on crop yields differ substantially in the magnitude and even direction of the projected change. Combining observations of current maximum-attainable yield with climate analogues, we provide a complementary method of assessing the effect of climate change on crop yields. Strong reductions in attainable yields of major cereal crops are found across a large fraction of current cropland by 2050. These areas are vulnerable to climate change and have greatly reduced opportunity for agricultural intensification. However, the total land area, including regions not currently used for crops, climatically suitable for high attainable yields of maize, wheat and rice is similar by 2050 to the present-day. Large shifts in land-use patterns and crop choice will likely be necessary to sustain production growth rates and keep pace with demand.
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| 42. |
- Shen, H, et al.
(author)
-
Flotability, selectivity and flotation separation of plastics by using a surfactant
- 2002
-
In: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 196, s. 63-70
-
Journal article (peer-reviewed)abstract
- In this paper, the floatability of seven plastics (POM, PVC, PET, PMMA, PC, PS and ABS) in the presence of alkyl ethoxylated nonionic surfactant (15-S-7) was investigated. It was found that the floatability of all the plastics decreases with the addition of the surfactant; but they are different in floatability and follow the order POM
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| 43. |
- Shen, H, et al.
(author)
-
Selective flotation separation of plastics by particle control
- 2001
-
In: Resources, Conservation and Recycling. - 0921-3449 .- 1879-0658. ; 33, s. 37-50
-
Journal article (peer-reviewed)abstract
- In this paper, the characteristics of plastics particles in the cutting products and flotation behaviours of plastics were studied. On this basis, the relation of floatability of plastics with surface chemical related factor and gravity factors was derived and discussed. From the results, it was shown that plastics flotation is dominated not only by surface chemical factors, but also significantly by gravity factors. It is suggested that plastics flotation is a combination of froth flotation and gravity separation. According to this relation, the idea of particle control was first applied for the separation of plastics mixture. From the separation results, it can be seen that this method can greatly increase the separation efficiency for flotation separation of plastics mixture
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| 44. |
- Thomas, E., et al.
(author)
-
From ‘entrepreneurial’ to ‘engaged’ universities : social innovation for regional development in the Global South
- 2020
-
In: Regional studies. - : Routledge. - 0034-3404 .- 1360-0591. ; 54:12, s. 1631-1643
-
Journal article (peer-reviewed)abstract
- Regional roles of universities in the Global South have been under-explored, and it is not clear how relevant are concepts originating from the Global North when applied in this context. The paper interrogates the concept of the ‘entrepreneurial university’ and its regional impact and engagement via a case study in Brazil. It is found that, in addition to purely entrepreneurial and economic activities and roles, initiatives relating to social innovation and entrepreneurship to solve profound regional problems are a key part of the university’s work.
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| 45. |
- Um, S-U, et al.
(author)
-
Aqueous solutions of ethyl (hydroxyethyl) cellulose and hydrophobic modified ethyl (hydroxyethyl) cellulose polymer: Dynamic surface tension measurements
- 1997
-
In: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 193, s. 41-49
-
Journal article (peer-reviewed)abstract
- The dynamic surface tension of aqueos solutions of ethyl (hydroxyethyl) cellulose (EHEC) and hydrophobic modified ethyl (hydroxyethyl) cellulose (HM-EHEC) were determined using the maximum bubble pressure method. Values were monitored over surface lifetimes ranging from 0.15 to 2.5 s (after dead time corrections). In the low concentration range (<100 ppm) HM-EHEC was shown to be more surface active and the presence of salt. (0.1M) was shown to increase the surface activity of both polymer systems. The results were compared to surface tension measurements carried out over longer time scales, determined using the du Nouy ring technique. From these results, isotherms were constructed relating the surface tension to the surface ageing time. Although the results could not be directly correlated to interfacial diffusion models, the isotherms were found to be comparable to previous data reported for lower molecular weight poly(oxyethylene ether) surfactants and a higher molecular weight EHEC polymer determined using the pendant drop technique. Essentially, the isotherms could be divided into distinct regions; induction period, fast fall region where surface coverage occurs fairly rapidly and finally the meso-equilibrium region. From the Gibbs equation, the number of segments of polymer per unit surface area at saturated adsorption levels was calculated over regions of different ageing times and the results were discussed in terms of configuration changes of the polymer at the interface.
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| 46. |
- Waltermo, Å, et al.
(author)
-
Foam films and surface force studies of aqueous solutions of octyl-ß-glucoside
- 1994
-
In: Journal of Dispersion Science and Technology. - 0193-2691 .- 1532-2351. ; 15, s. 273-296
-
Journal article (peer-reviewed)abstract
- The interactions at the air/liquid and the liquid/solid interface have been studied for octyl ß glucoside. With the thin film balance the thickness of the equilibrium liquid films is determined as a function of surfactant concentration, inert salt concentration and pH. At high surfactant concentration and/or at low. pH black films, about 4.6 nm thick, are formed. The stabilizing forces in the black films are related to the interactions within and between the layers. The forces acting between octyl-ß-glucoside surfactant layers adsorbed on hydrophobized mica were investigated with the interferometric type surface force apparatus. The forces measured between the sugar head-groups were similar to those acting between other small nonionic groups like dimethylamine oxide and monoglycerides. However, considerably more long-range repulsions are observed between surfactants with oligoethylene oxide head-groups.
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| 47. |
- Wang, Y, et al.
(author)
-
Magnetic aggregation in dispersions of mineral ultrafines
- 1995
-
In: Journal of Dispersion Science and Technology. - 0193-2691 .- 1532-2351. ; 16, s. 137-154
-
Journal article (peer-reviewed)abstract
- In the present paper, magnetic contribution on the aggregation of some magnetic mineral particle ultrafines were studied. There are two different magnetic properties that may enhance particle aggregation: a) field-induced magnetic moment; and b) magnetic moment due to the remanent magnetisation. The magnetic field-induced aggregation of the oxide mineral particle ultrafines (hematite and chromite) in aqueous suspension at moderate ionic strenght was investigated using a labortory scale electromagnetic solenoid. The experimental results relate the aggregation process (as determined by magneto-sedimentation analysis) to particle size and the external magnetic field in the antural pH value of the dispersions by using a modified form of the DLVO theory. In cases where the electrostratic repulsion was not suppressed, then the long range magnetic forces enabled aggregation to occur in the "secondary minimum" potential energy sink. This caused the formation of chains/rings, which appeared to be relatively stable at enhanced rates of settling. It is indicated in this paper that hematite ultrafines in a well-dispersed slurry are selectively aggregated with sized magnetite in the absence of aggregating reagents, high shear rates or an external magnetic field. The formation of aggregates is attributed to the presence of the remanent magnetisation in these oxide iron minerals, aminly in the magnetite.
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| 48. |
- Wang, Y, et al.
(author)
-
The influence of interparticle surface forces on the coagulation of weakly magnetic mineral ultrafines in a magnetic field
- 1994
-
In: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 90, s. 117-133
-
Journal article (peer-reviewed)abstract
- In this paper, it is shown that the coagulation of dispersions of weakly magnetic mineral ultrfines (such as hematite and chromite) in an external magnetic field can be described theoretically by invoking interparticle forces. Essentially, coagulation occurs when the short-range London-van der Waals interactions and the long-range magnetic forces outweight the stabilizing electric double layer repulsion. From classical colloid chemistry theory, we have calculated the the various components of the potential energy for different-sized particles at a series of ionic strenghts and magnetic field intensities. Principles governing the stability of the suspensions of weakly magnetic oxide mineral ultrafines in a "wet magnetic separation process". Experimentally, the magnetic-field induced coagulation of ultrafines of natural hematite and chromite in aqueous suspensions at moderate ionic strenght was investigated using a laboratory -scale electromagnetic solenoid. The experimental results relate the coagulation process (as determined by magnetosdimentation analysis) to particle size, slurry pH and the external magnetic field. In the magnetic fields, maximum coagulation occured near the pH of the point of zero charge (pH PZC)of the minerals (where the electrostatic double layer repulsionwas reduced to a minimum) enabling the particles to enter the"primary minimum" energy sink. In contrast, in cases where the electrostatic repulsion was not supressed, the long-range magnetic forces enabled coagulation to occur in the "secondary minimum". This caused the formation of chains which appeared to be relatively stable at enhanced rates of setting. The experimental results could be interpreted from a theoretical analysis of the interparticle forces controlling the process.
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| 49. |
- Wayman, Joseph P., et al.
(author)
-
Assessing taxonomic and functional change in British breeding bird assemblages over time
- 2022
-
In: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 31:5, s. 925-939
-
Journal article (peer-reviewed)abstract
- Aim: The aim was to identify the primary drivers of compositional change in breeding bird assemblages over a 40-year period. Location: Britain. Time period: From 1970 to 2010. Major taxa studied: Birds. Methods: Using morphological trait measurements and a dataset of presence–absence data for British breeding birds surveyed in 10 km × 10 km hectads during two time periods, we calculated temporal taxonomic and functional beta diversity for each hectad alongside the change in species richness, mean nearest taxon distance (MNTD) and mean pairwise distance (MPD). We also estimated potential drivers of beta diversity, including climatic and land-use and land-cover (LULC) change variables, elevation and assemblage species richness in 1970 (1970rich). We used random forest regressions to test which variables best explained compositional change in the assemblages. We also assessed spatial taxonomic and functional change by analysing multiple-site beta diversity and pairwise dissimilarities between time periods. Results: Initial (1970) species richness was the most important predictor (highest importance score) across all models, with areas characterized by higher initial richness experiencing less assemblage change overall. The coordinates included to capture spatial autocorrelation in the data were also important predictors of change. Most climate and LULC variables had relatively low explanatory power; elevation and average temperature were the most influential. All metrics increased slightly with increasing elevation, except for species richness change and MPD, which decreased. Main conclusions: The composition of British breeding bird assemblages changed substantially between 1970 and 2010. Spatial heterogeneity increased, both taxonomically and functionally. We show evidence that hectads with larger assemblages have been buffered from temporal diversity change and that those at higher elevations changed more in composition than those at lower elevations. Overall, coarse-resolution climate and LULC explained only small to moderate amounts of variation, suggesting that stochastic assembly change or finer-scale drivers might be drivers of temporal changes in assemblage composition.
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| 50. |
- Wayman, Joseph P., et al.
(author)
-
Identifying the Drivers of Spatial Taxonomic and Functional Beta-Diversity of British Breeding Birds
- 2021
-
In: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 9
-
Journal article (peer-reviewed)abstract
- Spatial variation in community composition may be driven by a variety of processes, including environmental filtering and dispersal limitation. While work has been conducted on the relative importance of these processes on various taxa and at varying resolutions, tests using high-resolution empirical data across large spatial extents are sparse. Here, we use a dataset on the presence/absence of breeding bird species collected at the 10 km × 10 km scale across the whole of Britain. Pairwise spatial taxonomic and functional beta diversity, and the constituent components of each (turnover and nestedness/richness loss or gain), were calculated alongside two other measures of functional change (mean nearest taxon distance and mean pairwise distance). Predictor variables included climate and land use measures, as well as a measure of elevation, human influence, and habitat diversity. Generalized dissimilarity modeling was used to analyze the contribution of each predictor variable to variation in the different beta diversity metrics. Overall, we found that there was a moderate and unique proportion of the variance explained by geographical distance per se, which could highlight the role of dispersal limitation in community dissimilarity. Climate, land use, and human influence all also contributed to the observed patterns, but a large proportion of the explained variance in beta diversity was shared between these variables and geographical distance. However, both taxonomic nestedness and functional nestedness were uniquely predicted by a combination of land use, human influence, elevation, and climate variables, indicating a key role for environmental filtering. These findings may have important conservation implications in the face of a warming climate and future land use change.
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