823 research outputs found
Advancing NLP with Cognitive Language Processing Signals
When we read, our brain processes language and generates cognitive processing
data such as gaze patterns and brain activity. These signals can be recorded
while reading. Cognitive language processing data such as eye-tracking features
have shown improvements on single NLP tasks. We analyze whether using such
human features can show consistent improvement across tasks and data sources.
We present an extensive investigation of the benefits and limitations of using
cognitive processing data for NLP. Specifically, we use gaze and EEG features
to augment models of named entity recognition, relation classification, and
sentiment analysis. These methods significantly outperform the baselines and
show the potential and current limitations of employing human language
processing data for NLP
Decoding EEG brain activity for multi-modal natural language processing
Until recently, human behavioral data from reading has mainly been of
interest to researchers to understand human cognition. However, these human
language processing signals can also be beneficial in machine learning-based
natural language processing tasks. Using EEG brain activity to this purpose is
largely unexplored as of yet. In this paper, we present the first large-scale
study of systematically analyzing the potential of EEG brain activity data for
improving natural language processing tasks, with a special focus on which
features of the signal are most beneficial. We present a multi-modal machine
learning architecture that learns jointly from textual input as well as from
EEG features. We find that filtering the EEG signals into frequency bands is
more beneficial than using the broadband signal. Moreover, for a range of word
embedding types, EEG data improves binary and ternary sentiment classification
and outperforms multiple baselines. For more complex tasks such as relation
detection, further research is needed. Finally, EEG data shows to be
particularly promising when limited training data is available
The requirement for calcification differs between ecologically important coccolithophore species
Summary
Coccolithophores are globally distributed unicellular marine algae that are characterized by their covering of calcite coccoliths. Calcification by coccolithophores contributes significantly to global biogeochemical cycles. However, the physiological requirement for calcification remains poorly understood as nonâcalcifying strains of some commonly used model species, such as Emiliania huxleyi, grow normally in laboratory culture.
To determine whether the requirement for calcification differs between coccolithophore species, we utilized multiple independent methodologies to disrupt calcification in two important species of coccolithophore: E. huxleyi and Coccolithus braarudii. We investigated their physiological response and used timeâlapse imaging to visualize the processes of calcification and cell division in individual cells.
Disruption of calcification resulted in major growth defects in C. braarudii, but not in E. huxleyi. We found no evidence that calcification supports photosynthesis in C. braarudii, but showed that an inability to maintain an intact coccosphere results in cell cycle arrest.
We found that C. braarudii is very different from E. huxleyi as it exhibits an obligate requirement for calcification. The identification of a growth defect in C. braarudii resulting from disruption of the coccosphere may be important in considering their response to future changes in ocean carbonate chemistry
Computing the zeros of the partial sums of the Riemann zeta function
In this paper, we introduce a formula for the exact number of zeros of every partial sum of the Riemann zeta function inside infinitely many rectangles of the critical strips where they are situated
Role of silicon in the development of complex crystal shapes in coccolithophores
The development of calcification by the coccolithophores had a profound impact on ocean carbon cycling, but the evolutionary steps leading to the formation of these complex biomineralized structures are not clear. Heterococcoliths consisting of intricately shaped calcite crystals are formed intracellularly by the diploid life cycle phase. Holococcoliths consisting of simple rhombic crystals can be produced by the haploid life cycle stage but are thought to be formed extracellularly, representing an independent evolutionary origin of calcification. We use advanced microscopy techniques to determine the nature of coccolith formation and complex crystal formation in coccolithophore life cycle stages. We find that holococcoliths are formed in intracellular compartments in a similar manner to heterococcoliths. However, we show that silicon is not required for holococcolith formation and that the requirement for silicon in certain coccolithophore species relates specifically to the process of crystal morphogenesis in heterococcoliths. We therefore propose an evolutionary scheme in which the lower complexity holococcoliths represent an ancestral form of calcification in coccolithophores. The subsequent recruitment of a silicon-dependent mechanism for crystal morphogenesis in the diploid life cycle stage led to the emergence of the intricately shaped heterococcoliths, enabling the formation of the elaborate coccospheres that underpin the ecological success of coccolithophores
Characterization of the molecular mechanisms of silicon uptake in coccolithophores
Coccolithophores are an important group of calcifying marine phytoplankton. Although coccolithophores are not silicified, some species exhibit a requirement for Si in the calcification process. These species also possess a novel protein (SITL) that resembles the SIT family of Si transporters found in diatoms. However, the nature of Si transport in coccolithophores is not yet known, making it difficult to determine the wider role of Si in coccolithophore biology. Here, we show that coccolithophore SITLs act as Na+-coupled Si transporters when expressed in heterologous systems and exhibit similar characteristics to diatom SITs. We find that CbSITL from Coccolithus braarudii is transcriptionally regulated by Si availability and is expressed in environmental coccolithophore populations. However, the Si requirement of C. braarudii and other coccolithophores is very low, with transport rates of exogenous Si below the level of detection in sensitive assays of Si transport. As coccoliths contain only low levels of Si, we propose that Si acts to support the calcification process, rather than forming a structural component of the coccolith itself. Si is therefore acting as a micronutrient in coccolithophores and natural populations are only likely to experience Si limitation in circumstances where dissolved silicon (DSi) is depleted to extreme levels
The AI Neuropsychologist: Automatic scoring of memory deficits with deep learning
Memory deficits are a hallmark of many different neurological and psychiatric conditions. The Rey-Osterrieth complex figure (ROCF) is the stateâof-the-art assessment tool for neuropsychologists across the globe to assess the degree of non-verbal visual memory deterioration. To obtain a score, a trained clinician inspects a patientâs ROCF drawing and quantifies deviations from the original figure. This manual procedure is time-consuming, slow and scores vary depending on the clinicianâs experience, motivation and tiredness. Here, we leverage novel deep learning architectures to automatize the rating of memory deficits. For this, a multi-head convolutional neural network was trained on 20225 ROCF drawings. Unbiased ground truth ROCF scores were obtained from crowdsourced human intelligence. The neural network outperforms both online raters and clinicians. Our AI-powered scoring system provides healthcare institutions worldwide with a digital tool to assess objectively, reliably and time-efficiently the performance in the ROCF test from hand-drawn images
Assessment of Daily Life Physical Activities in Pulmonary Arterial Hypertension
Background: In pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patientâs daily life physical activities (DLPA). Whether DLPA are decreased in PAH and whether the 6MWT is representative of patientâs DL PA remain unknown. Methods: 15 patients with idiopathic PAH (IPAH) and 10 patients with PAH associated with limited systemic sclerosis (PAH-SSc) were matched with 15 healthy control subjects and 10 patients with limited systemic sclerosis without PAH. Each subject completed a 6MWT. The mean number of daily steps and the mean energy expenditure and duration of physical activities.3 METs were assessed with a physical activity monitor for seven consecutive days and used as markers of DLPA. Results: The mean number of daily steps and the mean daily energy expenditure and duration of physical activities.3 METs were all reduced in PAH patients compared to their controls (all p,0.05). The mean number of daily steps correlated with the 6MWT distance for both IPAH and PAH-SSc patients (r = 0.76, p,0.01 and r = 0.85, p,0.01), respectively. Conclusion: DLPA are decreased in PAH and correlate with the 6MWT distance. Functional exercise capacity may thus be a useful surrogate of DL PA in PAH
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