Biology subjects

Davis, N.

Publications and source records attributed to Davis, N..

3 recordsLinked to original sources

bioRxiv2021

Annotation of Putative Circadian Rhythm-Associated Genes in Diaphorina citri (Hemiptera : Liviidae)

The circadian rhythm is a process involving multiple genes that generates an internal molecular clock, allowing organisms to anticipate environmental conditions produced by the earths rotation on its axis. This report presents the results of the manual curation of twenty-seven genes likely associated with circadian rhythm in the genome of Diaphorina citri, the Asian citrus psyllid. This insect acts as the vector of the bacterial pathogen Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus greening disease (Huanglongbing). This disease is the most severe detriment to citrus industries and has drastically decreased crop yields worldwide. Based on the genes identified in the psyllid genome, namely cry1 and cry2, D. citri likely possesses a circadian model similar to that of the lepidopteran butterfly, Danaus plexippus. Manual annotation of these genes will allow future molecular therapeutics to be developed that can disrupt the psyllid biology.

bioinformatics↗

bioRxiv2020

Generalized neural decoders for transfer learning across participants and recording modalities

ObjectiveAdvances in neural decoding have enabled brain-computer interfaces to perform increasingly complex and clinically-relevant tasks. However, such decoders are often tailored to specific participants, days, and recording sites, limiting their practical long-term usage. Therefore, a fundamental challenge is to develop neural decoders that can robustly train on pooled, multi-participant data and generalize to new participants. ApproachWe introduce a new decoder, HTNet, which uses a convolutional neural network with two innovations: (1) a Hilbert transform that computes spectral power at data-driven frequencies and (2) a layer that projects electrode-level data onto predefined brain regions. The projection layer critically enables applications with intracranial electrocorticography (ECoG), where electrode locations are not standardized and vary widely across participants. We trained HTNet to decode arm movements using pooled ECoG data from 11 of 12 participants and tested performance on unseen ECoG or electroencephalography (EEG) participants; these pretrained models were also subsequently fine-tuned to each test participant. Main resultsHTNet outperformed state-of-the-art decoders when tested on unseen participants, even when a different recording modality was used. By fine-tuning these generalized HTNet decoders, we achieved performance approaching the best tailored decoders with as few as 50 ECoG or 20 EEG events. We were also able to interpret HTNets trained weights and demonstrate its ability to extract physiologically-relevant features. SignificanceBy generalizing to new participants and recording modalities, robustly handling variations in electrode placement, and allowing participant-specific fine-tuning with minimal data, HTNet is applicable across a broader range of neural decoding applications compared to current state-of-the-art decoders.

neuroscience↗

bioRxiv2019

Association the 25(OH) vitamin D status with Upper Respiratory Tract Infections Morbidity in Water Sports Elite Athletes

BACKGROUNDThe aim of this study is to identify seasonal changes in total 25(OH) vitamin D (VD) concentrations and determine its influence on acute upper respiratory tract infection (URTI) morbidity among elite athletes engaged in water sports. METHODSThe study was planned as a prospective, non-interventional, observational study. Study participants included 40 elite athletes and 30 control individuals. Serum levels of 25(OH) VD and TNF-, IFN-{gamma}, IL-4 and IL-6 were detected by ELISA technique. Morbidity and frequency of acute URTI in participants were determined by self-reported questionnaire during the year. RESULTSThe predominance of VD insufficiency was found in both groups of elite athletes and in the control individuals. Prevalence of VD insufficiency/deficiency depends on the season, but independently on the season the highest values were observed among athletes. VD sufficiency was detected in 30% and 13.3% of the control individuals in August and February and only in 10% of swimmers in August. More than 3 episodes of URTI were detected only in the elite athletes in winter-spring. The elevated level of TNF-, IL-4, IL-6 was detected in all athletes, but more expressed increase was observed in swimmers. CONCLUSIONSVD insufficiency is quite pronounced among elite athletes engaged in synchronized swimming and in swimmers. It is accompanied with a decrease of IFN-{gamma}, increase of TNF-, IL-4 and IL-6 level, and elevation of URTI morbidity. Seasonal monitoring and correction of the VD level for normalization of cytokine profile and decrease of URTI morbidity is definitely advised.

epidemiology↗