A systematic review reveals conflicting evidence for the prevalence of antibodies against the sialic acid 'xenoautoantigen' Neu5Gc in humans and the need for a standardised approach to quantification.

Despite an array of hypothesised implications for health, disease, and therapeutic development, antibodies against the non-human sialic acid N-glycolylneuraminic acid (Neu5Gc) remain a subject of much debate. This systematic review of 114 publications aimed to generate a comprehensive overview of published studies in this field, addressing both the reported prevalence of anti-Neu5Gc antibodies in the human population and whether experimental variation accounts for the conflicting reports about the extent of this response. Absolute titres of anti-Neu5Gc antibodies, the reported prevalence of these antibodies, and the individual variation observed within experiments were analysed and grouped according to biological context ('inflammation', 'xenotransplantation', 'biotherapeutic use', 'cancer', and 'healthy populations'), detection method, target epitope selection, and choice of blocking agent. These analyses revealed that the experimental method had a notable impact on both the reported prevalence and absolute titres of anti-Neu5Gc antibodies in the general population, thereby limiting the ability to ascribe reported trends to genuine biological differences or the consequence of experimental design. Overall, this review highlights important knowledge gaps in the study of antibodies against this important xenoautoantigen and the need to establish a standardised method for their quantification if the extent of the importance of Neu5Gc in human health is to be fully understood.

Trans-radial cerebral angiography for stereotactic radiosurgery treatment of arteriovenous malformations.

OBJECTIVES: The popularity of trans-radial access (TRA) for cerebral angiography is growing. Potential benefits of TRA over traditional trans-femoral access (TFA) are multitude. This study aimed to evaluate discharge outcomes and patient opinion of TRA compared to TFA in patients undergoing cerebral angiography prior to stereotactic radiosurgery (SRS) treatment for cerebral arteriovenous malformations. METHODS: Consecutive patients treated at the National Centre for Stereotactic Radiosurgery (Sheffield, United Kingdom) over a 22-month period were included. All patients underwent cerebral angiography with either TRA or TFA as part of treatment planning prior to SRS. TRA patients who had previously undergone TFA in other centres were surveyed for their experience of cerebral angiography using a questionnaire. SRS staff at our centre was approached for their opinion. RESULTS: 492 patients were included (median age = 43 years, 57.5% male, median lesions treated = 1). More patients underwent angiography with TFA (75.2%) than TRA (24.8%). No difference was found in accumulated dose for angiography between the groups (p>0.05). There was 17.6% reduction in overnight stay between TRA and TRF, the proportion of patients requiring overnight admission was higher for the TFA (35.2%) than TRA (17.6%, p<0.05). 101 patients were surveyed, with a response rate of 47%. Most respondents (79%) indicated preference for TRA over TFA. CONCLUSIONS: Use of TRA in pre-SRS cerebral angiography is feasible and improves both patient and staff experience. The adoption of TRA could have important implications for department resources and costs by reducing the proportion of overnight admissions.

Short-Term Disruption of TGFß Signaling in Adult Mice Renders the Aorta Vulnerable to Hypertension-Induced Dissection.

Hypertension and transient increases in blood pressure from extreme exertion are risk factors for aortic dissection in patients with age-related vascular degeneration or inherited connective tissue disorders. Yet, the common experimental model of angiotensin II-induced aortopathy in mice appears independent of high blood pressure as lesions do not occur in response to an alternative vasoconstrictor, norepinephrine, and are not prevented by co-treatment with a vasodilator, hydralazine. We investigated vasoconstrictor administration to adult mice 1 week after disruption of TGFß signaling in smooth muscle cells. Norepinephrine increased blood pressure and induced aortic dissection by 7 days and even within 30 minutes that was rescued by hydralazine; results were similar with angiotensin II. Changes in regulatory contractile molecule expression were not of pathological significance. Rather, reduced synthesis of extracellular matrix yielded a vulnerable aortic phenotype by decreasing medial collagen, most dynamically type XVIII, and impairing cell-matrix adhesion. We conclude that transient and sustained increases in blood pressure cause dissection in aortas rendered vulnerable by inhibition of TGFß-driven extracellular matrix production by smooth muscle cells. A corollary is that medial fibrosis, a frequent feature of medial degeneration, may afford some protection against aortic dissection.

Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass-loss rate and stabilization.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The genes mgtE and spoVG are involved in zinc tolerance of Staphylococcus aureus.

Metals are essential for all living organisms, but the type of metal and its concentration determines its action. Even low concentrations of metals may have toxic effects on organisms and therefore exhibit antimicrobial activities. In this study, we investigate the evolutionary adaptation processes of Staphylococcus aureus to metals and common genes for metal tolerance. Laboratory and clinical isolates were treated with manganese, cobalt, zinc, or nickel metal salts to generate growth-adapted mutants. After growth in medium supplemented with zinc, whole-genome sequencing identified, among others, two genes, mgtE (SAUSA300_0910), a putative magnesium transporter and spoVG (SAUSA300_0475), a global transcriptional regulator, as hot spots for stress-induced single-nucleotide polymorphisms (SNPs). SNPs in mgtE were also detected in mutants treated with high levels of cobalt or nickel salts. To investigate the effect of these genes on metal tolerance, deletion mutants and complementation strains in an S. aureus USA300 LAC* laboratory strain were generated. Both, the mgtE and spoVG deletion strains were more tolerant to cobalt, manganese, and zinc. The mgtE mutant was also more tolerant to nickel exposure. Inductively coupled plasma mass spectrometry analysis demonstrated that the mgtE deletion mutant accumulated less intracellular zinc than the wild type, explaining increased tolerance. From these results, we conclude that mgtE gene inactivation increases zinc tolerance presumably due to reduced uptake of zinc. For the SpoVG mutant, no direct effect on the intracellular zinc concentration was detected, indicating toward different pathways to increase tolerance. Importantly, inactivation of these genes offers a growth advantage in environments containing certain metals, pointing toward a common tolerance mechanism. IMPORTANCE: Staphylococcus aureus is an opportunistic pathogen causing tremendous public health burden and high mortality in invasive infections. Treatment is becoming increasingly difficult due to antimicrobial resistances. The use of metals in animal husbandry and aquaculture to reduce bacterial growth and subsequent acquisition of metal resistances has been shown to co-select for antimicrobial resistance. Therefore, understanding adaptive mechanisms that help S. aureus to survive metal exposure is essential. Using a screening approach, we were able to identify two genes encoding the transporter MgtE and the transcriptional regulator SpoVG, which conferred increased tolerance to specific metals such as zinc when inactivated. Further testing showed that the deletion of mgtE leads to reduced intracellular zinc levels, suggesting a role in zinc uptake. The accumulation of mutations in these genes when exposed to other metals suggests that inactivation of these genes could be a common mechanism for intrinsic tolerance to certain metals.

Evaluating the oral delivery of GalNAc-conjugated siRNAs in rodents and non-human primates.

Oral delivery is the most widely used and convenient route of administration of medicine. However, oral administration of hydrophilic macromolecules is commonly limited by low intestinal permeability and pre-systemic degradation in the gastrointestinal (GI) tract. Overcoming some of these challenges allowed emergence of oral dosage forms of peptide-based drugs in clinical settings. Antisense oligonucleotides (ASOs) have also been investigated for oral administration but despite the recent progress, the bioavailability remains low. Given the advancement with highly potent and durable trivalent N-acetylgalactosamine (GalNAc)-conjugated small interfering RNAs (siRNAs) via subcutaneous (s.c.) injection, we explored their activities after oral administration. We report robust RNA interference (RNAi) activity of orally administrated GalNAc-siRNAs co-formulated with permeation enhancers (PEs) in rodents and non-human primates (NHPs). The relative bioavailability calculated from NHP liver exposure was <2.0% despite minimal enzymatic degradation in the GI. To investigate the impact of oligonucleotide size on oral delivery, highly specific GalNAc-conjugated single-stranded oligonucleotides known as REVERSIRs with different lengths were employed and their activities for reversal of RNAi effect were monitored. Our data suggests that intestinal permeability is highly influenced by the size of oligonucleotides. Further improvements in the potency of siRNA and PE could make oral delivery of GalNAc-siRNAs as a practical solution.

Statistical modeling of acute and chronic pain patient-reported outcomes obtained from ecological momentary assessment.

ABSTRACT: Ecological momentary assessment (EMA) allows for the collection of participant-reported outcomes (PROs), including pain, in the normal environment at high resolution and with reduced recall bias. Ecological momentary assessment is an important component in studies of pain, providing detailed information about the frequency, intensity, and degree of interference of individuals' pain. However, there is no universally agreed on standard for summarizing pain measures from repeated PRO assessment using EMA into a single, clinically meaningful measure of pain. Here, we quantify the accuracy of summaries (eg, mean and median) of pain outcomes obtained from EMA and the effect of thresholding these summaries to obtain binary clinical end points of chronic pain status (yes/no). Data applications and simulations indicate that binarizing empirical estimators (eg, sample mean, random intercept linear mixed model) can perform well. However, linear mixed-effect modeling estimators that account for the nonlinear relationship between average and variability of pain scores perform better for quantifying the true average pain and reduce estimation error by up to 50%, with larger improvements for individuals with more variable pain scores. We also show that binarizing pain scores (eg, <3 and ≥3) can lead to a substantial loss of statistical power (40%-50%). Thus, when examining pain outcomes using EMA, the use of linear mixed models using the entire scale (0-10) is superior to splitting the outcomes into 2 groups (<3 and ≥3) providing greater statistical power and sensitivity.

The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans.

The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the C. elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6 , a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1 , which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.

Aminated clay-polymer composite as soil amendment for stabilizing the short- and long-chain per- and poly-fluoroalkyl substances in contaminated soil.

Soils contaminated with per- and poly- fluoroalkyl substances (PFAS) require immediate remediation to protect the surrounding environment and human health. A novel animated clay-polymer composite was developed by applying polyethyleneimine (PEI) solution onto a montmorillonite clay-chitosan polymer composite. The resulting product, PEI-modified montmorillonite chitosan beads (MMTCBs) were characterized as an adsorptive soil amendment for immobilizing PFAS contaminants. The MMTCBs exhibited good efficiency to adsorb the PFAS, showing adsorption capacities of 12.2, 16.7, 18.5, and 20.8 mg g-1 for PFBA, PFBS, PFOA, and PFOS, respectively, which were higher than those obtained by granular activated carbon (GAC) (i.e., an adsorbent used as a reference). Column leaching tests demonstrated that amending soil with 10% MMTCBs resulted in a substantial decrease in the leaching of PFOA, PFOS, PFBA, and PFBS by 90%, 100%, 64%, and 68%, respectively. These reductions were comparable to the values obtained for GAC-modified soil, particularly for long-chain PFAS. Incorporating MMTCBs into the soil not only preserved the structural integrity of the soil matrix but also enhanced its shear strength (kPa). Conversely, adding GAC to the soil resulted in a reduction of the soil's mechanical properties.

EEG functional connectivity as a Riemannian mediator: An application to malnutrition and cognition.

Mediation analysis assesses whether an exposure directly produces changes in cognitive behavior or is influenced by intermediate "mediators". Electroencephalographic (EEG) spectral measurements have been previously used as effective mediators representing diverse aspects of brain function. However, it has been necessary to collapse EEG measures onto a single scalar using standard mediation methods. In this article, we overcome this limitation and examine EEG frequency-resolved functional connectivity measures as a mediator using the full EEG cross-spectral tensor (CST). Since CST samples do not exist in Euclidean space but in the Riemannian manifold of positive-definite tensors, we transform the problem, allowing for the use of classic multivariate statistics. Toward this end, we map the data from the original manifold space to the Euclidean tangent space, eliminating redundant information to conform to a "compressed CST." The resulting object is a matrix with rows corresponding to frequencies and columns to cross spectra between channels. We have developed a novel matrix mediation approach that leverages a nuclear norm regularization to determine the matrix-valued regression parameters. Furthermore, we introduced a global test for the overall CST mediation and a test to determine specific channels and frequencies driving the mediation. We validated the method through simulations and applied it to our well-studied 50+-year Barbados Nutrition Study dataset by comparing EEGs collected in school-age children (5-11 years) who were malnourished in the first year of life with those of healthy classmate controls. We hypothesized that the CST mediates the effect of malnutrition on cognitive performance. We can now explicitly pinpoint the frequencies (delta, theta, alpha, and beta bands) and regions (frontal, central, and occipital) in which functional connectivity was altered in previously malnourished children, an improvement to prior studies. Understanding the specific networks impacted by a history of postnatal malnutrition could pave the way for developing more targeted and personalized therapeutic interventions. Our methods offer a versatile framework applicable to mediation studies encompassing matrix and Hermitian 3D tensor mediators alongside scalar exposures and outcomes, facilitating comprehensive analyses across diverse research domains.

Low intraoperative end-tidal carbon dioxide levels are associated with improved recurrence-free survival after elective colorectal cancer surgery.

STUDY OBJECTIVE: Higher levels of carbon dioxide (CO2) increase the invasive abilities of colon cancer cells in vitro. Studies assessing target values for end-tidal CO2 concentrations (EtCO2) to improve surgical outcome after colorectal cancer surgery are lacking. Therefore, we evaluated whether intraoperative EtCO2 was associated with differences in recurrence-free survival after elective colorectal cancer (CRC) surgery. DESIGN: Single center, retrospective analysis. SETTING: Anesthesia records, surgical databases and hospital information system of a tertiary university hospital. PATIENTS: We analyzed 528 patients undergoing elective resection of colorectal cancer at Heidelberg University Hospital between 2009 and 2018. INTERVENTIONS: None. MEASUREMENTS: Intraoperative mean EtCO2 values were calculated. The study cohort was equally stratified into low-and high-EtCO2 groups. The primary endpoint measure was recurrence-free survival until last known follow-up. Groups were compared using Kaplan-Meier analysis. Cox-regression analysis was used to control for covariates. Sepsis, reoperations, surgical site infections and cardiovascular events during hospital stay, and overall survival were secondary outcomes. MAIN RESULTS: Mean EtCO2 was 33.8 mmHg ±1.2 in the low- EtCO2 group vs. 37.3 mmHg ±1.6 in the high-EtCO2 group. Median follow-up was 3.8 (Q1-Q3, 2.5-5.1) years. Recurrence-free survival was higher in the low-EtCO2 group (log-rank-test: p = .024). After correction for confounding factors, lower EtCO2 was associated with increased recurrence-free survival (HR = 1.138, 95%-CI:1.015-1.276, p = .027); the hazard for the primary outcome decreased by 12.1% per 1 mmHg decrease in mean EtCO2. 1-year and 5-year survival was also higher in the low-EtCO2 group. We did not find differences in the other secondary endpoints. CONCLUSIONS: Lower intraoperative EtCO2 target values in CRC surgery might benefit oncological outcome and should be evaluated in confirmative studies.

Palliative care integration and end-of-life care intensity for patients with NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) without oncogenic driver mutations is considered to have a poor prognosis, although recent therapeutic progress. This study aims to assess the real-life integration of palliative care (PC) and the intensity of end-of-life (EOL) care for this population. METHODS: This was an observational cohort study of decedent patients from metastatic NSCLC without oncogenic driver mutations over the period 01/2018 to 12/2022, treated in first line with immunotherapy +/- chemotherapy. We analysed PC integration and aggressiveness criteria of EOL care in the last month before death: systemic anti-cancer treatment administration, emergency room visits, intensive care unit admission, hospitalization, hospitalization duration > 14 days, and hospital death. RESULTS: Among 149 patients, 75 (50 %) met the PC team at least once, and the median time from the first encounter to death was 2.3 months. In the last month before death, at least one criterion of aggressive EOL care was present for 97 patients (70 %). For patients with PC use < 30 days and for patients with PC use < 90 days before death, there were significant changes: increase in the frequency of systemic anti-cancer treatment (respectively 51.1 % vs 20 %; p < 0.001 and 58.7 % vs 6.2 %; p < 0.001); decrease in hospitalization lasting > 14 days (respectively 30 % vs 7 %; p = 0.001 and 36 % vs 6.2 %; p = 0.018) and in death hospitalisation (respectively 66 % and 18 %; p < 0.001 and 58.7 % and 10.3 %; p < 0.001). After adjusting for the factors tested, patients with no PC or late PC use in the last month before death or in the last three month before death, the odds ratio (OR) remained significantly greater than 1 (respectively OR = 3.97 [1.70; 9.98]; p = 0.001 and OR = 23.1 [5.21-177.0], p < 0.0001). CONCLUSION: PC is still insufficiently integrated for patients with NSCL cancer. Cancer centres should monitor key indicators such as PC use and aggressiveness criteria of EOL care.

Novel applications of Convolutional Neural Networks in the age of Transformers.

Convolutional Neural Networks (CNNs) have been central to the Deep Learning revolution and played a key role in initiating the new age of Artificial Intelligence. However, in recent years newer architectures such as Transformers have dominated both research and practical applications. While CNNs still play critical roles in many of the newer developments such as Generative AI, they are far from being thoroughly understood and utilised to their full potential. Here we show that CNNs can recognise patterns in images with scattered pixels and can be used to analyse complex datasets by transforming them into pseudo images with minimal processing for any high dimensional dataset, representing a more general approach to the application of CNNs to datasets such as in molecular biology, text, and speech. We introduce a pipeline called DeepMapper, which allows analysis of very high dimensional datasets without intermediate filtering and dimension reduction, thus preserving the full texture of the data, enabling detection of small variations normally deemed 'noise'. We demonstrate that DeepMapper can identify very small perturbations in large datasets with mostly random variables, and that it is superior in speed and on par in accuracy to prior work in processing large datasets with large numbers of features.

Experience in the Management of Complex Apple Peel Intestinal Atresia in a Limited-Resource Health Center in Mexico.

Surgical treatment of complex intestinal atresia is challenging. Moreover, multiple surgical techniques have been described to treat these congenital malformations. As no single/universal technique is useful for every patient, individualized surgical treatment for these complex cases is mandatory. Isolated apple peel atresia (type IIIb), in coexistence with other types of atresia, is a rare event with a poor functional prognosis, which is difficult to treat surgically. Furthermore, the ability to achieve good surgical results becomes more difficult in resource-limited health facilities, such as the Hospital Pediatrico Moctezuma (Mexico City). The objective of this case report of two full-term female newborns with isolated apple peel atresia and an apple peel malformation with distal type IV atresia is to describe the successful surgical technique used in these patients and how to deal with certain postsurgical complications.

ALACEN: A Holistic Herbaceous Biomass Fractionation Process Attaining a Xylose-Rich Stream for Direct Microbial Conversion to Bioplastics.

Lignocellulose biorefining is a promising technology for the sustainable production of chemicals and biopolymers. Usually, when one component is focused on, the chemical nature and yield of the others are compromised. Thus, one of the bottlenecks in biomass biorefining is harnessing the maximum value from all of the lignocellulosic components. Here, we describe a mild stepwise process in a flow-through setup leading to separate flow-out streams containing cinnamic acid derivatives, glucose, xylose, and lignin as the main components from different herbaceous sources. The proposed process shows that minimal degradation of the individual components and conservation of their natural structure are possible. Under optimized conditions, the following fractions are produced from wheat straw based on their respective contents in the feed by the ALkaline ACid ENzyme process: (i) 78% ferulic acid from a mild ALkali step, (ii) 51% monomeric xylose free of fermentation inhibitors by mild ACidic treatment, (iii) 82% glucose from ENzymatic degradation of cellulose, and (iv) 55% native-like lignin. The benefits of using the flow-through setup are demonstrated. The retention of the lignin aryl ether structure was confirmed by HSQC NMR, and this allowed monomers to form from hydrogenolysis. More importantly, the crude xylose-rich fraction was shown to be suitable for producing polyhydroxybutyrate bioplastics. The direct use of the xylose-rich fraction by means of the thermophilic bacteria Schlegelella thermodepolymerans matched 91% of the PHA produced with commercial pure xylose, achieving 138.6 mgPHA/gxylose. Overall, the ALACEN fractionation method allows for a holistic valorization of the principal components of herbaceous biomasses.

Can the Dose of Belimumab be Reduced in Patients with Systemic Lupus Erythematosus?

OBJECTIVES: The aims of this study were to investigate the prevalence of dose reduction in patients with SLE treated with belimumab (BEL) in Spain, analyze treatment modalities, and determine impact on control of disease activity. METHODS: Retrospective longitudinal and multicentre study of SLE patients treated with BEL. Data on disease activity, treatments and outcomes were recorded before and after reduction (6-12 months), and they were compared. RESULTS: A total of 324 patients were included. The dose was reduced in 29 patients (8.9%). The dosing interval was increased in 9 patients receiving subcutaneous BEL and in 6 patients receiving intravenous BEL. The dose per administration was reduced in 16 patients.Pre-reduction status was remission (2021 DORIS) in 15/26 patients (57.7%) and LLDAS in 23/26 patients (88.5%). After reduction, 2/24 patients (8.3%) and 3/22 patients (13.6%) lost remission at 6 months and 12 months, respectively (not statistically significant [NS]). As for LLDAS, 2/23 patients (8.7%) and 2/21 patients (9.5%) lost their status at 6 and 12 months, respectively (NS). Significantly fewer patients were taking glucocorticoids (GCs) at their 12-month visit, although the median dose of GCs was higher at the 12-month visit (5 [0.62-8.75] vs 2.5 [0-5] at baseline). CONCLUSION: Doses of BEL can be reduced with no relevant changes in disease activity-at least in the short term-in a significant percentage of patients, and most maintain the reduced dose. However, increased clinical or serologic activity may be observed in some patients. Consequently, tighter post-reduction follow-up is advisable.

Biological invasions are a population-level rather than a species-level phenomenon.

Biological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio-economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general-via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species-level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population-level processes that govern successful invasions. To address these issues, we analyse non-native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species-level risk screenings and real population-level data were also identified, highlighting the inherent challenges in accurately assessing population-level effects through species-level assessments. In recognition of the importance of population-level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region-specific and population-focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies.

Deep learning-based auditory attention decoding in listeners with hearing impairment.

Objective.This study develops a deep learning (DL) method for fast auditory attention decoding (AAD) using electroencephalography (EEG) from listeners with hearing impairment (HI). It addresses three classification tasks: differentiating noise from speech-in-noise, classifying the direction of attended speech (left vs. right) and identifying the activation status of hearing aid noise reduction algorithms (OFF vs. ON). These tasks contribute to our understanding of how hearing technology influences auditory processing in the hearing-impaired population.Approach.Deep convolutional neural network (DCNN) models were designed for each task. Two training strategies were employed to clarify the impact of data splitting on AAD tasks: inter-trial, where the testing set used classification windows from trials that the training set had not seen, and intra-trial, where the testing set used unseen classification windows from trials where other segments were seen during training. The models were evaluated on EEG data from 31 participants with HI, listening to competing talkers amidst background noise.Main results.Using 1 s classification windows, DCNN models achieve accuracy (ACC) of 69.8%, 73.3% and 82.9% and area-under-curve (AUC) of 77.2%, 80.6% and 92.1% for the three tasks respectively on inter-trial strategy. In the intra-trial strategy, they achieved ACC of 87.9%, 80.1% and 97.5%, along with AUC of 94.6%, 89.1%, and 99.8%. Our DCNN models show good performance on short 1 s EEG samples, making them suitable for real-world applications. Conclusion: Our DCNN models successfully addressed three tasks with short 1 s EEG windows from participants with HI, showcasing their potential. While the inter-trial strategy demonstrated promise for assessing AAD, the intra-trial approach yielded inflated results, underscoring the important role of proper data splitting in EEG-based AAD tasks.Significance.Our findings showcase the promising potential of EEG-based tools for assessing auditory attention in clinical contexts and advancing hearing technology, while also promoting further exploration of alternative DL architectures and their potential constraints.

Hierarchical syntax model of music predicts theta power during music listening.

Linguistic research showed that the depth of syntactic embedding is reflected in brain theta power. Here, we test whether this also extends to non-linguistic stimuli, specifically music. We used a hierarchical model of musical syntax to continuously quantify two types of expert-annotated harmonic dependencies throughout a piece of Western classical music: prolongation and preparation. Prolongations can roughly be understood as a musical analogue to linguistic coordination between constituents that share the same function (e.g., 'pizza' and 'pasta' in 'I ate pizza and pasta'). Preparation refers to the dependency between two harmonies whereby the first implies a resolution towards the second (e.g., dominant towards tonic; similar to how the adjective implies the presence of a noun in 'I like spicy … '). Source reconstructed MEG data of sixty-five participants listening to the musical piece was then analysed. We used Bayesian Mixed Effects models to predict theta envelope in the brain, using the number of open prolongation and preparation dependencies as predictors whilst controlling for audio envelope. We observed that prolongation and preparation both carry independent and distinguishable predictive value for theta band fluctuation in key linguistic areas such as the Angular, Superior Temporal, and Heschl's Gyri, or their right-lateralised homologues, with preparation showing additional predictive value for areas associated with the reward system and prediction. Musical expertise further mediated these effects in language-related brain areas. Results show that predictions of precisely formalised music-theoretical models are reflected in the brain activity of listeners which furthers our understanding of the perception and cognition of musical structure.

Spiking activity in the visual thalamus is coupled to pupil dynamics across temporal scales.

The processing of sensory information, even at early stages, is influenced by the internal state of the animal. Internal states, such as arousal, are often characterized by relating neural activity to a single "level" of arousal, defined by a behavioral indicator such as pupil size. In this study, we expand the understanding of arousal-related modulations in sensory systems by uncovering multiple timescales of pupil dynamics and their relationship to neural activity. Specifically, we observed a robust coupling between spiking activity in the mouse dorsolateral geniculate nucleus (dLGN) of the thalamus and pupil dynamics across timescales spanning a few seconds to several minutes. Throughout all these timescales, 2 distinct spiking modes-individual tonic spikes and tightly clustered bursts of spikes-preferred opposite phases of pupil dynamics. This multi-scale coupling reveals modulations distinct from those captured by pupil size per se, locomotion, and eye movements. Furthermore, coupling persisted even during viewing of a naturalistic movie, where it contributed to differences in the encoding of visual information. We conclude that dLGN spiking activity is under the simultaneous influence of multiple arousal-related processes associated with pupil dynamics occurring over a broad range of timescales.