20 research outputs found
Daily allergy burden and heart rate characteristics in adults with allergic rhinitis based on a wearable telemonitoring system
Background: Allergic rhinitis includes a certain degree of autonomic imbalance. However, no information is available on how daily changes in allergy burden affect autonomic imbalance. We aimed to estimate associations between daily allergy burden (allergy symptoms and mood) and daily heart rate characteristics (resting heart rate and sample entropy, both biomarkers of autonomic balance) of adults with allergic rhinitis, based on real-world measurements with a wearable telemonitoring system. Methods: Adults with a tree pollen allergy used a smartphone application to self-report daily allergy symptoms (score 0–44) and mood (score 0–4), and a Mio Alpha 2 wristwatch to collect heart rate characteristics during two pollen seasons of hazel, alder and birch in Belgium. Associations between daily allergy burden and heart rate characteristics were estimated using linear mixed effects distributed lag models with a random intercept for individuals and adjusted for potential confounders. Results: Analyses included 2497 participant-days of 72 participants. A one-point increase in allergy symptom score was associated with an increase in next-day resting heart rate of 0.08 (95% CI: 0.02–0.15) beats per minute. A one-point increase in mood score was associated with an increase in same-day sample entropy of 0.80 (95% CI: 0.34–1.26) × 10−2. No associations were found between allergy symptoms and heart rate sample entropy, nor between mood and resting heart rate. Conclusion: Daily repeated measurements with a wearable telemonitoring system revealed that the daily allergy burden of adults with allergic rhinitis has systemic effects beyond merely the respiratory system.</p
BLOOM: A 176B-Parameter Open-Access Multilingual Language Model
Large language models (LLMs) have been shown to be able to perform new tasks
based on a few demonstrations or natural language instructions. While these
capabilities have led to widespread adoption, most LLMs are developed by
resource-rich organizations and are frequently kept from the public. As a step
towards democratizing this powerful technology, we present BLOOM, a
176B-parameter open-access language model designed and built thanks to a
collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer
language model that was trained on the ROOTS corpus, a dataset comprising
hundreds of sources in 46 natural and 13 programming languages (59 in total).
We find that BLOOM achieves competitive performance on a wide variety of
benchmarks, with stronger results after undergoing multitask prompted
finetuning. To facilitate future research and applications using LLMs, we
publicly release our models and code under the Responsible AI License
Health effects of exposure to green space, airborne pollen and air pollution A mobile health study on adults with tree pollen allergy
Over the past decades the prevalence of pollen allergy has increased. This trend is expected to continue due to ongoing urbanization, climate change and increasing air pollution. In order to mitigate urban heat and improve air quality in the city, urban green space has been promoted. Urban green spaces have been associated with numerous health benefits. Contact with the natural environment strengthens the human microbiome and immune system. Green spaces promote an active lifestyle and provide mental health benefits. By improving the air quality, green spaces can also contribute to better respiratory health. However, urban vegetation is also a source of airborne pollen.
The literature provides contradicting results regarding the effects of green space on the health of pollen allergy patients. These contradictions stem from the complex interactions between environmental factors, as well as from a heterogeneity in approaches when it comes to exposure studies. To properly study the health effects from exposure to green space on the health of people with pollen allergy we need detailed spatial data on green space and the allergenic trees within these greenspaces. In addition, we need insights in the effects of local vegetation on local pollen composition. Until now, the majority of exposure studies relied on exposure within various buffers around the residence. Nevertheless, a significant share of exposure takes place outside the residential area and pollen and air pollutant concentrations vary in time and space. In order to define exposure more realistically there is need for a method that can account for the spatiotemporal aspect of personal exposure.
Nevertheless, the first step towards an exposure analysis is the generation of a distribution model of potential allergenic trees. For Flanders a database with validated observations of vascular plants at a 1 km resolution is available (Florabank). The observations can be combined with environmental covariates (soil characteristics, land use, habitat type) in a species distribution model. We modelled habitat suitability for 13 wind-pollinated tree genera. Genus-specific thresholds were used to obtain presence-absence maps. By summing the 13 presence-absence maps we obtained a tree diversity map at genus-level. We find that summing binary maps does not result in an overestimation of diversity when the study area is urbanized (Flanders) and the spatial resolution is coarse (1 km). The obtained diversity map can be used to determine exposure to biodiversity in health studies.
In a second step, we studied the effects of local vegetation on the pollen composition. Although pollen can travel long distances, local vegetation contributes to local peak concentrations of pollen. Standardized pollen monitoring takes place at roof top level and measures a background level of pollen. Possible local peaks remain undetected, yet contribute to human pollen exposure. By mounting passive samplers at 2 m above the ground in 13 locations in Flanders we aimed to measure local pollen compositions during the tree pollen season (February-May) of 2017. The passive samplers successfully measured local pollen compositions characterized by 12 taxa. We used Non-metric Multidimensional Scaling (NMDS) to characterize each sampling site by its pollen composition. Then we use an indirect gradient analysis to associate the pollen composition with the land cover within a 20, 200, 500, 1000, 2000 and 5000 m radius around the sampling site. We found an urban-rural and wet-dry gradient associated with the first and second NMDS axis. Most of the associations were found for the land cover in a 1000-5000 m radius. This local scale effect is of importance for urban green management: urban forests at the edge of the city contribute to the pollen concentration within the city. In addition, we understand that environmental health studies require sufficiently large exposure radii.
Thus, in the residential exposure study we determined garden cover, grassland cover and forest cover within a 1, 2 and 5 km radius around the residence of 157 adults with a tree pollen allergy. The density of allergenic trees (alder, hazel and birch) was derived from the regional forest inventories. We used a generalized linear models with a Poisson distribution to associate residential exposure to mental well-being (standardized questionnaires) and respiratory health (average symptom severity reported in a smartphone application). All green space types were protective for mental well-being, yet a risk factor for symptom severity. The density of allergenic trees in forests was a risk factor for mental well-being as well as symptom severity. We found that green space effects on health became smaller as the exposure radius increased.
In an attempt to determine personal exposure more realistically, we used GPS data gathered by a smartphone application. We compared exposure between case-days with severe allergy symptoms and control-days without symptoms. We determined exposure by extracting green space cover, allergenic tree density, birch pollen levels and pollutant levels at the GPS point locations. For each day we could determine the average exposure taking into account spatiotemporal variability. Grassland cover, forest cover, alder density and hazel density protected against severe allergy symptoms. Birch density and birch pollen as well as pollutants (nitrogen dioxide (NO2), ozone (O3), and particulate matter < 10 µm (PM10)) were risk factors for severe allergy symptoms. For GPS tracks that were entirely within Flanders, we could calculate exposure to the tree diversity model at genus level. We found no associations between severe allergy symptoms and alpha-diversity of tree genera.
This manuscript shows that adults with a tree pollen allergy experience mental and respiratory health benefits from exposure to green space, given that density of allergenic trees (birch) is low. GPS tracking allowed for a more realistic approximation of personal exposure. Although we did not identify a diversity effect, we do promote biodiverse urban green spaces in order to prevent domination of allergenic vegetation.status: accepte
Detectie van spatio-temporele patronen in de verplaatsingen van everzwijn o.b.v. GPS-telemetrie
status: publishe
A comparison of machine learning algorithms for regional wheat yield prediction using NDVI time series of SPOT-VGT
This study compares two machine learning algorithms to predict regional winter wheat yields. The models, based on Boosted Regression Trees (BRT) and Support Vector Machines (SVM), are constructed of Normalized Difference Vegetation Indices (NDVI) derived from low resolution SPOT VEGETATION imagery. Three types of NDVI-related predictors were used: Single NDVI, Incremental NDVI and Targeted NDVI. BRT and SVM were first used to select features with high relevance for predicting the yield. Periods of high influence spanning from March to June were detected by both machine learning methods. After feature selection, BRT and SVM models were applied to the subset of selected features for yield forecasting. BRT seems to consistently outperform SVM.status: publishe
Everzwijnen met halsband
Moderne technologiën zorgen ervoor dat we dieren op een veel nauwkeurigere manier kunnen bestuderen. Dankzij GPS-halsbanden slagen we erin om bewegingspatronen van everzwijnen gedetailleerd weer te geven. Deze gegevens kunnen worden gebruikt om schade door everzwijnen in kaart te brengen en de groeiende populatie op een duurzame manier te beherenstatus: publishe
Residential green space and mental health in a prospective cohort of tree pollen allergy patients
BACKGROUND: Green space may improve human health, for example by promoting physical activity and by reducing stress. Conversely, green space may exacerbate the burden of allergic disease by emitting aeroallergens.
OBJECTIVES: We examined whether residential exposure to green space had impacts on mental health in adults sensitized to tree pollen allergens during two airborne tree pollen seasons (2017, 2018).
METHODS: In this cross-sectional study, data from a prospective Belgian cohort of tree pollen allergy patients (N = 88) were analyzed using Poisson regression. The primary outcome was self-reported mental health, assessed with the standardized 12-item General Health Questionnaire (GHQ-12). Predictors of distress included perceived presence of allergenic trees near the residence (hazel, alder, birch) and cumulative green space area within 1 km distance. Results were compared to distress in a representative sample of the general population (N = 2,467).
RESULTS: Short-term distress [mean GHQ-12 score 2.1 (95% confidence interval 1.5–2.7)] was higher in the study population than in the general population [1.5 (1.4–1.7)]. Distress increased with BMI {adjusted odds ratio [95% confidence interval] 1.06 (1.02–1.10)}, smoking [2.10 (1.02–4.38)] and perceived presence of allergenic trees [2.04 (1.36–3.07)]. Physical activity [>1×/week 20 minutes of activity vs. less: 0.59 (0.42–0.85)], age [0.97 (0.96–0.99)] and green space [≥ 3m tall, per combined surface area of 10 ha: 0.94 (0.90–0.99); < 3m tall, per 10 ha: 0.85 (0.78–0.93)] had protective effects against short-term distress.
CONCLUSIONS: The perceived proximity to allergenic tree species modulates the protective effect of residential green space against short-term emotional distress during the airborne pollen season. Negative expectations of adults sensitized to tree pollen allergens regarding exposure to allergenic tree species may affect short-term mental health outcomes during the pollen season.status: publishe
An evaluation of species distribution models to estimate tree diversity at genus level in a heterogeneous urban-rural landscape
Trees provide ecosystem services that improve the environment and human health. The magnitude of these improvements may be related to tree diversity within green spaces, yet spatially explicit diversity data necessary to investigate such associations are often missing. Here, we evaluate two methods to model tree diversity at genus level based on environmental covariates and presence point data. We want to identify the drivers and suitable methods for urban and rural tree diversity models in the heterogeneous region of Flanders, Belgium.
We stratified our research area into dominantly rural and dominantly urban areas and developed distribution models for 13 tree genera for both strata as well as for the area as a whole. Occurrence data were obtained from an open-access presence-only database of validated observations of vascular plants. These occurrence data are combined with environmental covariates in MaxEnt models. Tree diversity is modelled by adding up the individual species distribution models.
Models in the dominantly rural areas are driven by soil characteristics (soil texture and drainage class). Models in the dominantly urban areas are driven by environmental covariates explaining urban heterogeneity. Nevertheless, the stratification into urban and rural did not contribute to a higher model quality. Generic tree diversity estimates were better when presences derived from distribution models were simply added up (binary stacking, True Positive Rate of 0.903). The application of macro-ecological constraints resulted in an underestimation of generic tree diversity (probability stacking, True Positive Rate of 0.533). We conclude that summing presences derived from species distribution models (binary stacking) is a suitable approach to increase knowledge on regional diversity.status: Published onlin
Association between local airborne tree pollen composition and surrounding land cover across different spatial scales in Northern Belgium
Airborne pollen are important aeroallergens affecting human health. Local airborne pollen compositions can pose health-risks for the sensitized population, but at present little is known about fine-scale pollen composition patterns.
The overall objective of this study is to determine local variations in tree pollen composition with passive samplers and to identify the surrounding landscape characteristics that drive them. In February–May 2017, during the tree pollen season, airborne tree pollen were measured by passive sampling at 2 m height above ground-level in 14 sites in the Flanders and Brussels-Capital region (Belgium). Non-metric multidimensional scaling was used to investigate environmental gradients that determine the pollen composition and amounts. Land cover types were identified across spatial scales ranging between 20 m and 5 km.
The passive samplers detected the same pollen taxa during the same time windows as the validated volumetric Burkard samplers. Using passive samplers, we were able to measure local airborne pollen compositions. Corylus and Platanus pollen were associated to urban areas; Populus, Juglans and Fraxinus pollen to agricultural areas; forests and wetlands were sources of Alnus and Quercus pollen. Salix, Populus and Betula pollen were also mainly associated to wetlands. The landscape context drives the airborne tree pollen composition at a meso-scale (1−5 km) rather than at finer scale (20−500 m). Thus, land cover types (e.g. forest, bush land, agricultural lands and wetlands) surrounding urban areas may increase exposure to allergenic pollen in the urban area, potentially affecting the health of a large proportion of the population.</p
Predicting allergenic tree species distributions from the Belgian soil map and a gridded presence database of vascular plants
Tree pollen are a major source of aeroallergens which trigger allergic reactions in sensitized people. Climate change increases the burden of tree-related allergic diseases as higher temperatures and changes in precipitation patterns increase the duration and intensity of pollination of allergenic tree species such as birch (Betula spp.). Information on the distribution of allergenic tree species may be helpful to quantify the potential exposure to tree allergens but to date such detailed species distribution maps are lacking. To address this issue, we modelled the probability of occurrence of the thirteen most prominent allergenic tree species in Flanders.
We used maximum entropy modelling to calculate probabilities of tree species occurrence based on presence-only data sourced from an open access databank of plant species distributions in Flanders and environmental variables related to the potential natural distribution of tree species in Flanders. Soil texture was used as a proxy for soil fertility and soil drainage class as a proxy for soil moisture. Both variables were derived from the Belgian Soil Map resampled to 1×1 km grid cells. We used landscape types from the Biological Valuation Map and average lowest and highest ground water from Ecoplan as additional environmental predictor variables.
Species distribution models were more meaningful than a random distribution for all thirteen allergenic tree species. The Area Under Curve (AUC) varied between 0.53 for Salix and 0.92 for Platanus. Texture class and drainage class were consequently among the most important variables contributing to the models. Probabilities of occurrence were converted to distribution maps using varying expert-based thresholds for the different allergenic tree species. A combined alpha diversity map of allergenic tree species shows hotspots of allergenic tree species diversity in the Campine region and a lower diversity in more industrialised or agriculture dominated parts of Flanders.status: publishe