72 research outputs found
Macrophage Migration Inhibitory Factor: Gene Polymorphisms and Susceptibility to Inflammatory Diseases
The cytokine macrophage migration inhibitory factor (MIF) is a constitutive element of the host antimicrobial defenses and stress response that promotes proinflammatory function of the innate and acquired immune systems. MIF plays an important role in the pathogenesis of acute and chronic inflammatory or autoimmune disorders, such as sepsis, acute respiratory distress syndrome, asthma, rheumatoid arthritis, and inflammatory bowel diseases. Polymorphisms of the humanMIF gene (that is, guanine-to-cytosine transition at position -173 or CATT-tetranucleotide repeat at position -794) have been associated with increased susceptibility to or severity of juvenile idiopathic and adult rheumatoid arthritis, ulcerative colitis, atopy, or sarcoidosis. Whether theseMIF polymorphisms affect the susceptibility to and outcome of sepsis has not yet been examined. Analyses ofMIF genotypes in patients with sepsis may help to classify patients into risk categories and to identify those patients who may benefit from anti-MIF therapeutic strategie
Exploring Category Structure with Contextual Language Models and Lexical Semantic Networks
Recent work on predicting category structure with distributional models,
using either static word embeddings (Heyman and Heyman, 2019) or contextualized
language models (CLMs) (Misra et al., 2021), report low correlations with human
ratings, thus calling into question their plausibility as models of human
semantic memory. In this work, we revisit this question testing a wider array
of methods for probing CLMs for predicting typicality scores. Our experiments,
using BERT (Devlin et al., 2018), show the importance of using the right type
of CLM probes, as our best BERT-based typicality prediction methods
substantially improve over previous works. Second, our results highlight the
importance of polysemy in this task: our best results are obtained when using a
disambiguation mechanism. Finally, additional experiments reveal that
Information Contentbased WordNet (Miller, 1995), also endowed with
disambiguation, match the performance of the best BERT-based method, and in
fact capture complementary information, which can be combined with BERT to
achieve enhanced typicality predictions
Association between High Levels of Blood Macrophage Migration Inhibitory Factor, Inappropriate Adrenal Response, and Early Death in Patients with Severe Sepsis
Background.Identification of new therapeutic targets remains an imperative goal to improve the morbidity and mortality associated with severe sepsis and septic shock. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and counterregulator of glucocorticoids, has recently emerged as a critical mediator of innate immunity and experimental sepsis, and it is an attractive new target for the treatment of sepsis. Methods.Circulating concentrations of MIF were measured in 2 clinical trial cohorts of 145 pediatric and adult patients who had severe sepsis or septic shock caused predominantly by infection with Neisseria meningitidis or other gram-negative bacteria, to study the kinetics of MIF during sepsis, to analyze the interplay between MIF and other mediators of sepsis or stress hormones (adrenocorticotropic hormone and cortisol), and to determine whether MIF is associated with patient outcome. Results.Circulating concentrations of MIF were markedly elevated in 96% of children and adults who had severe sepsis or septic shock, and they remained elevated for several days. MIF levels were correlated with sepsis severity scores, presence of shock, disseminated intravascular coagulation, urine output, blood pH, and lactate and cytokine levels. High levels of MIF were associated with a rapidly fatal outcome. Moreover, in meningococcal sepsis, concentrations of MIF were positively correlated with adrenocorticotropic hormone levels and negatively correlated with cortisol levels and the cortisol : adrenocorticotropic hormone ratio, suggesting an inappropriate adrenal response to sepsis. Conclusions.MIF is markedly and persistently up-regulated in children and adults with gram-negative sepsis and is associated with parameters of disease severity, with dysregulated pituitary-adrenal function in meningococcal sepsis, and with early deat
EEG Data Quality: Determinants and Impact in a Multicenter Study of Children, Adolescents, and Adults with Attention-Deficit/Hyperactivity Disorder (ADHD)
Electroencephalography (EEG) represents a widely established method for assessing altered and typically developing brain function. However, systematic studies on EEG data quality, its
correlates, and consequences are scarce. To address this research gap, the current study focused on
the percentage of artifact-free segments after standard EEG pre-processing as a data quality index.
We analyzed participant-related and methodological influences, and validity by replicating landmark
EEG effects. Further, effects of data quality on spectral power analyses beyond participant-related
characteristics were explored. EEG data from a multicenter ADHD-cohort (age range 6 to 45 years),
and a non-ADHD school-age control group were analyzed (ntotal = 305). Resting-state data during
eyes open, and eyes closed conditions, and task-related data during a cued Continuous Performance
Task (CPT) were collected. After pre-processing, general linear models, and stepwise regression
models were fitted to the data. We found that EEG data quality was strongly related to demographic
characteristics, but not to methodological factors. We were able to replicate maturational, task,
and ADHD effects reported in the EEG literature, establishing a link with EEG-landmark effects.
Furthermore, we showed that poor data quality significantly increases spectral power beyond effects of maturation and symptom severity. Taken together, the current results indicate that with
a careful design and systematic quality control, informative large-scale multicenter trials characterizing neurophysiological mechanisms in neurodevelopmental disorders across the lifespan are
feasible. Nevertheless, results are restricted to the limitations reported. Future work will clarify
predictive value
Integrated global assessment of the natural forest carbon potential
Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system 1. Remote-sensing estimates to quantify carbon losses from global forests 2–5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced 6 and satellite-derived approaches 2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea 2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets
The global biogeography of tree leaf form and habit
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling
The global biogeography of tree leaf form and habit
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling
The global biogeography of tree leaf form and habit.
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling
The global biogeography of tree leaf form and habit
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling
The global biogeography of tree leaf form and habit
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cyclin
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