684 research outputs found
Empirically Derived Suitability Maps to Downscale Aggregated Land Use Data
Understanding mechanisms that drive present land use patterns is essential in order to derive appropriate models of land use change. When static analyses of land use drivers are performed, they rarely explicitly deal with spatial autocorrelation. Most studies are undertaken on autocorrelation-free data samples. By doing this, a great deal of information that is present in the dataset is lost. This paper presents a spatially explicit, cross-sectional, logistic analysis of land use drivers in Belgium. It is shown that purely regressive logistic models can only identify trends or global relationships between socio-economic or physico-climatic drivers and the precise location of each land use type. However, when the goal of a study is to obtain the best model of land use distribution, a purely autoregressive (or neighbourhood-based) model is appropriate. Moreover, it is also concluded that a neighbourhood based only on the 8 surrounding cells leads to the best logistic regression models at this scale of observation. This statement is valid for each land use type studied â i.e. built-up, forests, cropland and grassland.
Deep Learning for scalp High Frequency Oscillations Identification
Since last 2 decades, High Frequency Oscillations (HFOs) are studied as a
promising biomarker to localize the epileptogenic zone of patients with
refractory focal epilepsy. As HFOs visual detection is time consuming and
subjective, automatization of HFO detection is required. Most HFO detectors
were developed on invasive electroencephalograms (iEEG) whereas scalp
electroencephalograms (EEG) are used in clinical routine. In order HFO
detection can benefit to more patients, scalp HFO detectors has to be
developed. However, HFOs identification in scalp EEG is more challenging than
in iEEG since scalp HFOs are of lower rate, lower amplitude and more likely to
be corrupted by several sources of artifacts than iEEG HFOs. The main goal of
this study is to explore the ability of deep learning architecture to identify
scalp HFOs from the remaining EEG signal. Hence, a binary classification
Convolutional Neural Network (CNN) is learned to analyze High Density
Electroencephalograms (HD-EEG). EEG signals are first mapped into a 2D
time-frequency image, several color definitions are then used as an input for
the CNN. Experimental results show that deep learning allows simple end-to-end
learning of preprocessing, feature extraction and classification modules while
reaching competitive performance
Autoimmune Epilepsy: Some Epilepsy Patients Harbor Autoantibodies to Glutamate Receptors and dsDNA on both Sides of the Blood-brain Barrier, which may Kill Neurons and Decrease in Brain Fluids after Hemispherotomy
Purpose: Elucidating the potential contribution of specific autoantibodies (Ab's)
to the etiology and/or pathology of some human epilepsies. Methods: Six epilepsy
patients with Rasmussen's encephalitis (RE) and 71 patients with other epilepsies
were tested for Ab's to the âBâ peptide (amino acids 372-395) of the glutamate/AMPA
subtype 3 receptor (GluR3B peptide), double-stranded DNA (dsDNA), and
additional autoimmune disease-associated autoantigens, and for the ability of their
serum and cerebrospinal-fluid (CSF) to kill neurons. Results: Elevated anti-GluR3B
Ab's were found in serum and CSF of most RE patients, and in serum of 17/71
(24%) patients with other epilepsies. In two RE patients, anti-GluR3B Ab's
decreased drastically in CSF following functional-hemispherotomy, in association
with seizure cessation and neurological improvement. Serum and CSF of two RE
patients, and serum of 12/71 (17%) patients with other epilepsies, contained
elevated anti-dsDNA Ab's, the hallmark of systemic-lupus-erythematosus. The sera
(but not the CSF) of some RE patients contained also clinically elevated levels of
âclassicalâ autoimmune Ab's to glutamic-acid-decarboxylase,
cardiolipin,
ÎČ2-glycoprotein-I and nuclear-antigens SS-A and RNP-70. Sera and CSF of some
RE patients caused substantial death of hippocampal neurons. Conclusions: Some
epilepsy patients harbor Ab's to GluR3 and dsDNA on both sides of the blood-brain
barrier, and additional autoimmune Ab's only in serum. Since all these Ab's may
be detrimental to the nervous system and/or peripheral organs, we recommend
testing
for their presence in epilepsy, and silencing their activity in Ab-positive patients
Silencing Nociceptor Neurons Reduces Allergic Airway Inflammation
Lung nociceptors initiate cough and bronchoconstriction. To elucidate if these fibers also contribute to allergic airway inflammation, we stimulated lung nociceptors with capsaicin and observed increased neuropeptide release and immune cell infiltration. In contrast, ablating Nav1.8(+) sensory neurons or silencing them with QX-314, a charged sodium channel inhibitor that enters via large-pore ion channels to specifically block nociceptors, substantially reduced ovalbumin- or house-dust-mite-induced airway inflammation and bronchial hyperresponsiveness. We also discovered that IL-5, a cytokine produced by activated immune cells, acts directly on nociceptors to induce the release of vasoactive intestinal peptide (VIP). VIP then stimulates CD4(+) and resident innate lymphoid type 2 cells, creating an inflammatory signaling loop that promotes allergic inflammation. Our results indicate that nociceptors amplify pathological adaptive immune responses and that silencing these neurons with QX-314 interrupts this neuro-immune interplay, revealing a potential new therapeutic strategy for asthma
- âŠ