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- MacDougall, Andrew S., et al.
(author)
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Widening global variability in grassland biomass since the 1980s
- 2024
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In: Nature Ecology & Evolution. - : Springer Nature. - 2397-334X.
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Journal article (peer-reviewed)abstract
- Global change is associated with variable shifts in the annual production of aboveground plant biomass, suggesting localized sensitivities with unclear causal origins. Combining remotely sensed normalized difference vegetation index data since the 1980s with contemporary field data from 84 grasslands on 6 continents, we show a widening divergence in site-level biomass ranging from +51% to −34% globally. Biomass generally increased in warmer, wetter and species-rich sites with longer growing seasons and declined in species-poor arid areas. Phenological changes were widespread, revealing substantive transitions in grassland seasonal cycling. Grazing, nitrogen deposition and plant invasion were prevalent in some regions but did not predict overall trends. Grasslands are undergoing sizable changes in production, with implications for food security, biodiversity and carbon storage especially in arid regions where declines are accelerating.
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| 2. |
- Villalaín, C., et al.
(author)
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Diagnostic accuracy of prenatal ultrasound in coarctation of aorta : systematic review and individual participant data meta-analysis
- 2024
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In: Ultrasound in Obstetrics and Gynecology. - 0960-7692. ; 63:4, s. 446-456
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Research review (peer-reviewed)abstract
- Objective: To determine the diagnostic accuracy of prenatal ultrasound in detecting coarctation of the aorta (CoA). Methods: An individual participant data meta-analysis was performed to report on the strength of association and diagnostic accuracy of different ultrasound signs in detecting CoA prenatally. MEDLINE, EMBASE and CINAHL were searched for studies published between January 2000 and November 2021. Inclusion criteria were fetuses with suspected isolated CoA, defined as ventricular and/or great vessel disproportion with right dominance on ultrasound assessment. Individual participant-level data were obtained by two leading teams. PRISMA-IPD and PRISMA-DTA guidelines were used for extracting data, and the QUADAS-2 tool was used for assessing quality and applicability. The reference standard was CoA, defined as narrowing of the aortic arch, diagnosed after birth. The most commonly evaluated parameters on ultrasound, both in B-mode and on Doppler, constituted the index test. Summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and likelihood ratios were computed using the hierarchical summary receiver-operating-characteristics model. Results: The initial search yielded 72 studies, of which 25 met the inclusion criteria. Seventeen studies (640 fetuses) were included. On random-effects logistic regression analysis, tricuspid valve/mitral valve diameter ratio > 1.4 and > 1.6, aortic isthmus/arterial duct diameter ratio < 0.7, hypoplastic aortic arch (all P < 0.001), aortic isthmus diameter Z-score of < −2 in the sagittal (P = 0.003) and three-vessel-and-trachea (P < 0.001) views, pulmonary artery/ascending aorta diameter ratio > 1.4 (P = 0.048) and bidirectional flow at the foramen ovale (P = 0.012) were independently associated with CoA. Redundant foramen ovale was inversely associated with CoA (P = 0.037). Regarding diagnostic accuracy, tricuspid valve/mitral valve diameter ratio > 1.4 had a sensitivity of 72.6% (95% CI, 48.2–88.3%), specificity of 65.4% (95% CI, 46.9–80.2%) and DOR of 5.02 (95% CI, 1.82–13.9). The sensitivity and specificity values were, respectively, 75.0% (95% CI, 61.1–86.0%) and 39.7% (95% CI, 27.0–53.4%) for pulmonary artery/ascending aorta diameter ratio > 1.4, 47.8% (95% CI, 14.6–83.0%) and 87.6% (95% CI, 27.3–99.3%) for aortic isthmus diameter Z-score of < –2 in the sagittal view and 74.1% (95% CI, 58.0–85.6%) and 62.0% (95% CI, 41.6–78.9%) for aortic isthmus diameter Z-score of < –2 in the three-vessel-and-trachea view. Hypoplastic aortic arch had a sensitivity of 70.0% (95% CI, 42.0–88.6%), specificity of 91.3% (95% CI, 78.6–96.8%) and DOR of 24.9 (95% CI, 6.18–100). The diagnostic yield of prenatal ultrasound in detecting CoA did not change significantly when considering multiple categorical parameters. Five of the 11 evaluated continuous parameters were independently associated with CoA (all P < 0.001) but all had low-to-moderate diagnostic yield. Conclusions: Several prenatal ultrasound parameters are associated with an increased risk for postnatal CoA. However, diagnostic accuracy is only moderate, even when combinations of parameters are considered.
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| 5. |
- D'Antonio, F, et al.
(author)
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Visual hallucinations in Lewy body disease: pathophysiological insights from phenomenology
- 2022
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In: Journal of neurology. - : Springer Science and Business Media LLC. - 1432-1459 .- 0340-5354. ; 269:7, s. 3636-3652
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Journal article (peer-reviewed)abstract
- Visual hallucinations (VH) in Lewy body disease (LBD) have a heterogenous phenomenology classified into minor phenomena (MVH) and complex hallucinations (CVH). Mechanisms underpinning VH and their temporal aspects are largely unknown. According to the hodotopic model, we investigated whether changes in distinct cognitive domains and neural networks in the hallucination trait underpin temporal aspects of MVH and CVH in the hallucination state. 35 LBD patients with VH underwent a complete neuropsychological evaluation and resting-state fMRI. North-East-Visual-Hallucinations-Interview was used to assess their typical VH content, duration, and frequency. We found that MVH was not associated with cognitive impairment, while CVH was associated with impairments in visuoperceptual processes, attention and visual abstract reasoning. In seed-to-seed functional connectivity (FC) analysis we identified functional couplings associated with MVH and CVH temporal severity (duration x frequency), duration and frequency. MVH severity was negatively associated with FC between early visual areas (EVA) and ventral-visual-stream regions, and negatively associated with FC between brainstem and EVA, which may be linked to LBD brainstem neuropathology. CVH duration was positively associated with FC between ventral-visual stream and salience network (SN). CVH frequency was negatively associated with FC between DMN and SN. Functional alterations in distinct visual and attentional networks and their dynamic interaction in trait LBD hallucinators are linked to both the phenomenology of state content and its temporal characteristics. Within a network, VH frequency and duration may be linked to different types of functional alterations: increased connectivity leading to sustained activity prolonging VH (duration) and decreased connectivity increasing dysregulated, spontaneous activity (frequency). These findings support the hodotopic hypothesis of VH and may reflect a link between VH phenomenology, LBD neuropathological progression and the involvement of specific neurotransmitter systems.
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