Biology subjects

Xu, Y.

Publications and source records attributed to Xu, Y..

At least 775 records · Page 43Linked to original sources

bioRxiv2021

Stand-alone lipoylated H-protein of the glycine cleavage system enables glycine cleavage and the synthesis of glycine from one-carbon compounds in vitro

H-protein, one of the four component proteins (H, T, P and L) of glycine cleavage system (GCS), is generally considered a shuttle protein interacting with the other three GCS-proteins via a lipoyl swinging arm. We report that without P-, T- and L-proteins, lipoylated H-protein (Hlip) enables GCS reactions in both glycine cleavage and synthesis directions in vitro. This apparent catalytic activity is closely related to the cavity on the H-protein surface where the lipoyl arm is attached. Heating or mutation of selected residues in the cavity destroys or reduces the stand-alone activity of Hlip, which can be restored by adding the other three GCS-proteins. Systematic study of the Hlip-catalyzed overall GCS reactions and the individual reaction steps provides a first step towards understanding the stand-alone function of Hlip. The results in this work provide some inspiration for further understanding the mechanism of the GCS and give some interesting implications on the evolution of the GCS. Significance statementGlycine cleavage system (GCS) plays central roles in C1 and amino acids metabolisms and the biosynthesis of purines and nucleotides. Manipulations of GCS are desired to promote plant growth or to treat serious pathophysiological processes such as aging, obesity and cancers. Reversed GCS reactions form the core of the reductive glycine pathway (rGP), one of the most promising pathway for the assimilation of formate and CO2 in the emerging C1-synthetic biology. H-protein, one of the four GCS component proteins (H, T, P and L) is generally considered a shuttle protein interacting with the other three proteins via a lipoyl swinging arm. Here, we discovered that without P-, T- and L-proteins, H-protein alone can catalyze GCS reactions in both glycine cleavage and synthesis directions in vitro. The surprising catalytic activities are related to a structural region of H-protein which can be manipulated. The results have impacts on engineering GCS to treat related diseases, to improve photorespiration, and to efficiently use C1-carbon for biosynthesis.

biochemistry↗

bioRxiv2021

SMARCA4 regulates spatially restricted metabolic plasticity in 3D multicellular tissue

SWI/SNF and related chromatin remodeling complexes act as tissue-specific tumor suppressors and are frequently inactivated in different cancers. Although many regulatory activities of SWI/SNF have been identified using 2D cell culture, the effects of SWI/SNF alterations in more complex 3D tissues have remained poorly understood. Here we employed 3D cell culture conditions that yield transcriptomic states mirroring primary lung adenocarcinoma (LUAD) specimens better than 2D culture. By analyzing spatial patterns of gene expression and DNA accessibility in 3D spheroids using single-cell RNA-seq and ATAC-seq, we find that the SWI/SNF ATPase SMARCA4 (BRG1) induces state-specific changes to DNA accessibility that influence spatially heterogeneous expression patterns and metabolism. In 3D conditions, SMARCA4 promotes accessibility for AP-1 transcription factors, including ATF3, a regulator of metabolism and repressor of NRF2 antioxidant signaling. These changes reduce expression of SLC7A11 in a distinct portion of cells, which sensitizes A549 spheroids to cell death via ferroptosis under oxidizing conditions. Consistent with these results, we find that SMARCA4 alterations are associated with derepression of NRF2 targets in human tumors independently of NRF2/KEAP1 status. Our work reveals new 3D-specific features and unanticipated spatial complexity associated with chromatin remodeling in multicellular tissues.

systems biology↗

bioRxiv2021

Microglial refinement of spinal cord sensory circuitry regulates normal maturation of dynamic touch.

Sensory systems are shaped in postnatal life by the refinement of synaptic connections. In the dorsal horn of the spinal cord, sensory circuits undergo postnatal activity dependent reorganisation, including the retraction of primary afferent A-fibres from superficial to deeper laminae which is accompanied by decreases in cutaneous sensitivity. Here we show that microglia, the resident immune cells in the CNS, phagocytose A-fibre terminals in superficial laminae in the first weeks of life. Genetic perturbation of microglial engulfment at that time prevents the normal process of A-fibre retraction, resulting in increased sensitivity of dorsal horn cells to dynamic tactile cutaneous stimulation, and behavioural hypersensitivity to dynamic touch. Thus, functional microglia are necessary for normal postnatal development of dorsal horn sensory circuits. In the absence of microglial engulfment, superfluous A-fibre projections remain in the dorsal horn and the balance of sensory connectivity is disrupted, leading to lifelong hypersensitivity to dynamic touch. Impact statementMicroglia phagocytose superfluous A-fibres in the superficial spinal dorsal horn during normal development, the disruption of which leads to long term aberrant dynamic touch processing and behaviour.

neuroscience↗

bioRxiv2021

Circular RNA Vaccines against SARS-CoV-2 and Emerging Variants

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its emerging variants of concern (VOC), such as Delta (B.1.617.2) and Omicron (B.1.1.529), has continued to drive the worldwide pandemic. Therefore, there is a high demand for vaccines with enhanced efficacy, high thermostability, superior design flexibility, and fast manufacturing speed. Here, we report a circular RNA (circRNA) vaccine that encodes the trimeric RBD of SARS-CoV-2 Spike protein. Without the need of nucleotide modification, 5-capping or 3-polyadenylation, circRNA could be rapidly produced via in vitro transcription and is highly thermostable whether stored in naked or lipid-nanoparticle (LNP)-encapsulated format. LNP-encapsulated circRNARBD elicited potent neutralizing antibodies and T cell responses, providing robust protection against Beta (B.1.351) and native viruses in mice and rhesus macaques, respectively. Notably, circRNA vaccine enabled higher and more durable antigen production than 1m{Psi}-modified mRNA vaccine, eliciting a higher proportion of neutralizing antibodies and stronger Th1-biased immune responses. Importantly, we found that circRNARBD-Omicron vaccine induced effective neutralizing antibodies against only Omicron but not Delta variant. By contrast, circRNARBD-Delta could elicit high level of neutralizing antibodies against both Delta and Omicron. Following two doses of either native- or Delta-specific vaccination, circRNARBD-Delta, but not Omicron or Beta vaccines, could effectively boost the neutralizing antibodies against both Delta and Omicron variants. These results suggest that circRNARBD-Delta is a favorable choice for vaccination to provide a broad-spectrum protection against the current variants of concern of SARS-CoV-2.

immunology↗

bioRxiv2021

Hypothalamic perineuronal nets are regulated by sex and dietary interventions

Perineuronal nets (PNNs) are widely present in the hypothalamus, and are thought to provide physical protection and ion buffering for neurons, and regulate their synaptic plasticity and intracellular signaling. Recent evidence indicates that PNNs in the mediobasal hypothalamus plays an important role in the regulation of glucose homeostasis. However, whether and how hypothalamic PNNs are regulated are not fully understood. In the present study, we examined whether PNNs in various hypothalamic regions in mice can be regulated by sex, gonadal hormones, dietary interventions, or their interactions. We demonstrated that gonadal hormones are required to maintain normal PNNs in the arcuate nucleus of hypothalamus in both male and female mice. In addition, PNNs in the terete hypothalamic nucleus display a sexual dimorphism with females higher than males, and high-fat diet feeding increases terete PNNs only in female mice but not in male mice. On the other hand, PNNs in other hypothalamic regions are not influenced by sex, gonadal hormones or dietary interventions. In summary, we demonstrated that hypothalamic PNNs are regulated in a region-specific manner and these results provide a framework to further investigate the potential functions of PNNs in regulating energy/glucose homeostasis at the interplay of sex, gonadal hormones and diets.

neuroscience↗

bioRxiv2021

Development of Large-Scale Brain Network Dynamics in Children

Functional brain networks require dynamic reconfiguration to support flexible cognitive function. However, the developmental principles shaping brain network dynamics remain poorly understood. Here, we report the longitudinal development of large-scale brain network dynamics during childhood and adolescence, and its connection with gene expression profiles. Using a multilayer network model, we show the temporally varying modular architecture of child brain networks, with higher network switching primarily in the association cortex and lower switching in the primary regions. This topographical profile exhibits progressive maturation, which manifests as reduced modular dynamics, particularly in the transmodal (e.g., default-mode and frontoparietal) and sensorimotor regions. These developmental refinements mediate age-related enhancements of global network segregation and are linked with the expression profiles of genes associated with the enrichment of ion transport and nucleobase-containing compound transport. These results highlight a progressive stabilization of brain dynamics, which expand our understanding of the neural mechanisms that underlie cognitive development.

neuroscience↗

bioRxiv2021

Drug-driven reclassification of multiple tumour subtypes reveals intrinsic molecular concordance of therapy across histologically disparate cancers

Cancers that are histologically defined as the same type of cancer often need a distinct therapy based on underlying heterogeneity; likewise, histologically disparate cancers can require similar treatment approaches due to intrinsic similarities. A comprehensive analysis integrated with drug response data and genomic alterations, particularly to reveal therapeutic concordance mechanisms across histologically disparate tumour subtypes, has not yet been fully exploited. In this study, we used pharmacogenomic profiling data provided from the Cancer Genome Project (CGP) in a systematic in silico investigation of the pharmacological subtypes of cancers and the intrinsic concordance of molecular mechanisms leading to similar therapeutic responses across histologically disparate tumour subtypes. We further developed a novel approach to redefine cell-to-cell similarity and drug-to-drug similarity from the therapeutic concordance, providing a new point of view to study cancer heterogeneity. Our study identified that histologically different tumours, such as malignant melanoma and colorectal adenocarcinoma, could belong to the same pharmacological subtype regarding drug sensitivity to MEK inhibitors, which was determined by their genomic alterations, high occurrence of BRAF or KRAS mutations. Therapeutic concordance for chemotherapy drugs was identified across histologically disparate hematological tumors mainly due to the extraordinary activation of the cell cycle in blood cancers. A subcluster of SCLC had a more similar profile with hematological tumors, and was associated with the malignant phenotype, with a higher level of MYC expression. We developed a website to store and visualize the pharmacological subtypes of drugs, as well as their connected genomic and expression alterations.

bioinformatics↗

bioRxiv2021

Metabolic characteristics of taste differences under the soil and hydroponic cultures of sweet potato leaves by using non-targeted metabolomics

Sweet potato leaves are consumed as green leafy vegetables in most of the world due to their nutritional and functional values, and the taste characteristics determine their commodity value and consumer acceptance. However, the metabolic composition and formation mechanism of taste quality in its leaves are not clear. In this study, we found that sweet potato leaves under different growing patterns, soil culture and hydroponic culture, which result in different taste quality. In particular, the taste quality in leafy sweet potato was effectively improved under hydroponic culture. Meanwhile, we further profiled metabolites in leaves of sweet potatoes under different growing patterns by using GC-QToF-MS. A total of 200 metabolites were identified, covering most of the metabolic pathways in plants. A comparison of the good taste and poor taste of sweet potato leaves resulted in 71 metabolites related to taste quality formation. In addition, the leaves with poor taste had lower levels of metabolites regarding amino acids metabolism, whereas was accompanied by high levels of metabolites in carbohydrates and secondary metabolism. This study provides new insights into the improvement of taste quality in leafy sweet potato.

plant biology↗

bioRxiv2021

Time-restricted feeding near dawn entrains long-term behavioral changes through the suprachiasmatic nucleus

The suprachiasmatic nucleus (SCN) is a master circadian pacemaker known to integrate light intensity and seasonal information with peripheral tissues to coordinate daily rhythms of physiology and behavior. However, the contribution of food information to the regulation of the SCN network remains controversial. Here, we identified the effect induced by time-restricted feeding (TRF) at dawn, but not at another time widow, inducing a robust and long-term shift in locomotor behavior and increased wakefulness. Comparing the oscillations of intracellular Ca2+ signals in the SCN GABAergic neurons of freely moving mice, before and after TRF, revealed significant activation of these neurons in dawn-TRF mice. Moreover, RNA-seq profiling in the dawn TRF-induced behavioral changes identified altered expressed genes involved in regulating extracellular exosome, ion transporters, and ECM-receptor interaction, but not core clock genes. Furthermore, injection in the SCN of insulin-like growth factor (IGF2) inhibitor Chromeceptin, targeting the most upregulated gene in extracellular exosome, abolished the after effect induced by ZT0-4 TRF. Finally, GABAergic-neuron-specific disruption of the potassium-chloride cotransporter Kcc2 intensified the dawn TRF-induced after effect, indicating that Kcc2 encodes food intake derived signals that control SCN clock entrainment. Thus, our study functionally links SCN GABAergic neuron activity and central clock entrainment regulation to both hunger- and food-response-related behaviors in mice.

physiology↗

bioRxiv2021

Age and Race related changes in Gene Expression during Human PBMC aging

Human immune system functions over an entire lifetime, yet how and why the immune system becomes less effective with age are not well understood. Here, we characterize peripheral blood mononuclear cells transcriptome from 172 healthy adults with 21~90 years of age using RNA-seq and the weighted gene correlation network analyses (WGCNA). These data reveal a set of insightful gene expression modules and representative gene biomarkers for human immune system aging from Asian and Caucasian ancestry, respectively. Among them, the aging-specific modules show an age-related gene expression variation spike around early-seventies. In addition, it is not known whether Asian and Caucasian immune systems go through similar gene expression changes throughout their lifespan, and to what extent these aging-associated changes are shared among ethnicities. We find the top hub genes including NUDT7, CLPB, OXNAD1 and MLLT3 are shared between Asian and Caucasian aging related modules and further validated in human PBMCs from different age groups. Overall, the impact of age and race on transcriptional variation elucidated from this study provide insights into the transcriptional driver of immune aging.

immunology↗

bioRxiv2021

Synergy of chemotherapy and macrophage depletion leads to T cell memory activation and durable triple negative breast cancer regression

Immunosuppressive elements within the tumor microenvironment such as Tumor Associated Macrophages (TAMs) can present a barrier to successful anti-tumor responses by cytolytic T cells. We employed preclinical syngeneic p53 null mouse models of triple negative breast cancer (TNBC) to develop a treatment regimen that harnessed the immunostimulatory effects of low-dose cyclophosphamide coupled with the pharmacologic inhibition of TAMs using either a small molecule CSF1R inhibitor or an anti-CSF1R antibody. This therapeutic combination was used to successfully treat several highly aggressive TNBC murine mammary tumors and lung metastasis. Using this regimen and single cell RNA sequencing we characterized tumor infiltrating lymphocytes (TILs) including helper T cells and antigen-presenting B cells that were highly enriched in good responders to combination therapy. Using high dimensional imaging techniques, we identified the close spatial localization of B220+ CD86+ activated B cells and CD4+ T cells in tertiary lymphoid structures that were present up to 6 weeks post-treatment in one model that also exhibited long-term tumor regression post-treatment. We also characterized the transcriptional and metabolic heterogeneity of TAMS in these two closely related claudin-low/mesenchymal subtype tumor models with differential treatment responses. A murine TAM signature derived from the T12 model is highly expressed and conserved in human claudin-low breast cancers, and high expression of the T12 signature correlated with reduced overall survival. This T12 tumor TAM signature may help identify human claudin-low breast cancer patients that will benefit from the combination of cyclophosphamide and anti-CSF1R therapy. These studies illustrate the complexity of the tumor immune microenvironment and highlight different immune responses that result from rationale combinations of immunotherapy. SignificanceA treatment regimen that harnessed the immunostimulatory effects of cyclophosphamide coupled with the inhibition of CSF1R was used to successfully treat several highly aggressive claudin-low TNBC murine mammary tumors and lung metastasis.

cancer biology↗

bioRxiv2021

Dopamine receptor DOP-1 engages a sleep pathway to modulate swimming in C. elegans

Animals require robust yet flexible programs to support locomotion. While it is clear that a variety of processes must be engaged to ensure rhythmic actions, the exact mechanisms remain largely unknown. Here we report a novel pathway that connects the D1-like dopamine receptor DOP-1 with a sleep mechanism to modulate swimming in C. elegans. We show that DOP-1 plays a negative role in sustaining swimming behavior. By contrast, a pathway through the D2-like dopamine receptor DOP-3 negatively regulates the initiation of swimming, but its impact fades quickly over a few minutes. We find that DOP-1 and the GPCR kinase GRK-2 function in the sleep interneuron RIS, where DOP-1 modulates the secretion of a sleep neuropeptide FLP-11. Our genetic studies further show that DOP-1 and FLP-11 act in the same pathway to modulate swimming. Together, these results delineate a functional connection between a dopamine receptor and a sleep program to regulate swimming in C. elegans. The temporal transition between DOP-3 and DOP-1 pathways highlights the dynamic nature of neuromodulation for rhythmic movements that persist over time. HIGHLIGHTSO_LIThe D1-like dopamine receptor DOP-1 regulates swimming at 10 minutes C_LIO_LIAn integrated function of DOP-1 and DOP-3 is required for the continuity of swimming C_LIO_LIDOP-1 and GRK-2 act in the sleep neuron RIS C_LIO_LIFLP-11, a neuropeptide that promotes sleep, negatively regulates swimming C_LI IN BRIEFXu et al. investigated genetic programs that modulate swimming behavior in the nematode C. elegans. They identified a functional link that couples a D1-like dopamine receptor to a sleep program that modulates the sustained phase rather than the initial phase of swimming.

genetics↗

bioRxiv2021

Extended Graphical Lasso for Multiple Interaction Networks for High Dimensional Computational Data

There has been a spate of interest in association networks in biological and medical research, for example, genetic interaction networks. In this paper, we propose a novel method, the extended joint hub graphical lasso (EDOHA), to estimate multiple related interaction networks for high dimensional omics data across multiple distinct classes. To be specific, we construct a convex penalized log likelihood optimization problem and solve it with an alternating direction method of multipliers (ADMM) algorithm. The proposed method can also be adapted to estimate interaction networks for high dimensional compositional data such as microbial interaction networks. The performance of the proposed method in the simulated studies shows that EDOHA has remarkable advantages in recognizing class-specific hubs than the existing comparable methods. We also present three applications of real datasets. Biological interpretations of our results confirm those of previous studies and offer a more comprehensive understanding of the underlying mechanism in disease. Author summaryReconstruction of multiple association networks from high dimensional omics data is an important topic, especially in biology. Previous studies focused on estimating different networks and detecting common hubs among all classes. Integration of information over different classes of data while allowing difference in the hub nodes is also biologically plausible. Therefore, we propose a method, EDOHA, to jointly construct multiple interaction networks with capacity in finding different hub networks for each class of data. Simulation studies show the better performance over conventional methods. The method has been demonstrated in three real world data.

systems biology↗

bioRxiv2021

Soluble guanylate cyclase stimulation mitigates skeletal and cardiac muscle dysfunction in a mdx model of Duchenne muscular dystrophy

The impairment of neuronal nitric oxide synthase (nNOS) signaling contributes to disease pathology in the muscle wasting disorder Duchenne muscular dystrophy (DMD). nNOS signal propagation occurs through nitric oxide sensitive soluble guanylate cyclase (sGC), a critical source of cyclic guanosine monophosphate (cGMP) in muscle. Although both nNOS and sGC activity are impaired in DMD patients, little is known about sGC as a therapeutic target. In this study, we tested the hypothesis that stimulating sGC activity with the allosteric agonist BAY41-8543 mitigates striated muscle pathology in the mdx4cv mouse model of DMD. In contrast to DMD patients, mdx mice exhibited greater basal sGC activity than wild type controls with preservation of cGMP levels due partly to upregulation of sGC in some muscles. Stimulating sGC activity in mdx mice with BAY41-8543 substantially reduced skeletal muscle damage, macrophage densities and inflammation and significantly increased resistance to contraction-induced fatigue. BAY41-8543 also enhanced in vivo diaphragm function while reducing breathing irregularities suggesting improved respiratory function. BAY41-8543 attenuated cardiac hypertrophic remodeling, fibrosis and diastolic dysfunction including left atrium enlargement in aged mdx mice. Overall, sGC stimulation significantly mitigated skeletal and cardio-respiratory dysfunction in mdx4cv mice. Importantly, this study provides compelling pre-clinical evidence supporting sGC as a novel target in DMD and the repurposing of FDA-approved sGC stimulators, such as riociguat and veraciguat, as a novel therapeutic approach for DMD.

physiology↗

bioRxiv2021

Hydroxide ions amplified by water entanglement underly the mechanism of general anesthesia

It is believed that inhaled anesthetics occupy hydrophobic pockets within target proteins, but how inhaled anesthetics with diverse shapes and sizes fit into highly structurally selective pockets is unknown. For hydroxide ions are hydrophobic, we determined whether hydroxide ions could bridge inhaled anesthetics and protein pockets. We found that small additional load of cerebral hydroxide ions decreases anesthetic potency. Multiple-water entanglement network, derived from Ising model, has a great ability to amplify ultralow changes in the cerebral hydroxide ion concentration, and consequently, amplified hydroxide ions account for neural excitability. Molecular dynamics simulations showed that inhaled anesthetics produce anesthesia by attenuating the formation of multiple-water entanglement network. This work suggests amplified hydroxide ions underlying a unified mechanism for the anesthetic action of inhaled anesthetics.

animal behavior and cognition↗

bioRxiv2021

SMILE: Mutual Information Learning for Integration of Single Cell Omics Data

Deep learning approaches have empowered single-cell omics data analysis in many ways, generating new insights from complex cellular systems. As there is an increasing need for single cell omics data to be integrated across sources, types, and features of data, the challenges of integrating single-cell omics data are rising. Here, we present a deep clustering algorithm that learns discriminative representation for single-cell data via maximizing mutual information, SMILE (Single-cell Mutual Information Learning). Using a unique cell-pairing design, SMILE successfully integrates multi-source single-cell transcriptome data, removing batch effects and projecting similar cell types, even from different tissues, into the same representation space. SMILE can also integrate data from two or more modalities, such as joint profiling technologies using singlecell ATAC-seq, RNA-seq, DNA methylation, Hi-C, and ChIP data. SMILE works well even when feature types are unmatched, such as genes for RNA-seq and genome wide peaks for ATAC-seq.

bioinformatics↗

bioRxiv2021

TRIPLE-NEGATIVE BREAST CANCER CELLS RECRUIT NEUTROPHILS BY SECRETING TGF-β AND CXCR2 LIGANDS

Tumor associated neutrophils (TANs) are frequently detected in triple-negative breast cancer (TNBC). Recent studies also reveal the importance of neutrophils in promoting tumor progression and metastasis during breast cancer. However, the mechanisms regulating neutrophil trafficking to breast tumors are less clear. We sought to determine whether neutrophil trafficking to breast tumors is determined directly by the malignant potential of cancer cells. We found that tumor conditioned media (TCM) harvested from highly aggressive, metastatic TNBC cells induced a polarized morphology and robust neutrophil migration, while TCM derived from poorly aggressive estrogen receptor positive (ER+) breast cancer cells had no activity. In a three-dimensional (3D) type-I collagen matrix, neutrophils migrated toward TCM from aggressive breast cancer cells with increased velocity and directionality. Moreover, in a neutrophil-tumor spheroid co-culture system, neutrophils migrated with increased directionality towards spheroids generated from TNBC cells compared to ER+ cells. Based on these findings, we next sought to characterize the active factors secreted by TNBC cell lines. We found that TCM-induced neutrophil migration is dependent on tumor-derived chemokines, and screening TCM elution fractions based on their ability to induce polarized neutrophil morphology revealed the molecular weight of the active factors to be around 12 kDa. TCM from TNBC cell lines contained copious amounts of GRO (CXCL1/2/3) chemokines and TGF-{beta} cytokines compared to ER+ cell-derived TCM. TCM activity was inhibited by simultaneously blocking receptors specific to GRO chemokines and TGF-{beta}, while the activity remained intact in the presence of either single receptor inhibitor. Together, our findings establish a direct link between the malignant potential of breast cancer cells and their ability to induce neutrophil migration. Our study also uncovers a novel coordinated function of TGF-{beta} and GRO chemokines responsible for guiding neutrophil trafficking to the breast tumor.

immunology↗

bioRxiv2021

Evolutionary selection on synonymous codons in RNA G-quadruplex structural region

In addition to the amino acid sequence information, synonymous codons can encode multiple regulatory and structural signals in protein coding region. In this study, we investigated how synonymous codons have been adapted to the formation of RNA G-quadruplex (rG4) structure. We found a universal selective pressure acting on synonymous codons to facilitate rG4 formation in five eukaryotic organisms. While G-rich codons are preferred in rG4 structural region, C-rich codons are selectively unpreferred for rG4 structures. Genes codon usage bias, nucleotide composition and evolutionary rate can account for the selective variations on synonymous codons among rG4 structures within a species. Moreover, rG4 structures in translational initiation region showed significantly higher selective pressures than those in translational elongation region. These results bring us another dimension of evolutionary selection on synonymous codons for proper RNA structure and function.

bioinformatics↗