Miracle-dz/UniFAR-FTUs huggingface dataset:
Membrane Voltage Dynamics of Parvalbumin Interneurons Orchestrate Hippocampal Theta Rhythmicity

Hippocampal network activity at theta frequencies (5-10Hz) is important for behavior. However, it remains unclear how behaviorally-relevant network theta rhythms arise and interact with cellular dynamics to dictate spike timing. We performed membrane voltage (Vm) imaging of individual CA1 pyramidal cells and parvalbumin interneurons with simultaneous local field potential (LFP) recordings in mice during locomotion. We found that Vm theta rhythms organize spike timing in both cell types regardless of behavioral conditions, but the Vm of parvalbumin interneurons is better synchronized with LFP. The temporal relationships between spikes and LFP theta reliably reflect the Vm-LFP relationships in parvalbumin cells, but not in pyramidal cells. Thus, cellular theta rhythms broadly organize spike timing in CA1 neurons, and parvalbumin interneurons are critical in coordinating network theta rhythms. One-Sentence Summary Cellular membrane voltage of parvalbumin interneurons organizes spiking and network dynamics in the hippocampus.
Analysis of Larval Fish Feeding Behavior under Naturalistic Conditions

Modern research efforts concerned with animal behavior rely heavily on image and video analysis. While such data are now quick to obtain, extracting and analyzing complex behaviors under naturalistic conditions is still a major challenge, specifically when the behavior of interest is sporadic and rare. In this study, we present an end-to-end system for capturing, detecting and analyzing larval fish feeding behavior in unconstrained naturalistic environments. We first constructed a specialized system for imaging these tiny, fast-moving creatures and deployed it in large aquaculture rearing pools. We then designed an analysis pipeline using several action classification backbones, and compare their performance. A natural feature of the data was the extremely low prevalence of feeding events, leading to low sample sizes and highly imbalanced datasets despite extensive annotation efforts. Nevertheless, our pipeline successfully detected and classified the sparsely-occurring feeding behavior of fish larvae in a curated experimental setting from videos featuring multiple animals. We introduce three new annotated datasets of underwater videography, in a curated and an uncurated setting. As challenges related to data imbalance and expert’s annotation are common to the analysis of animal behavior under naturalistic conditions, we believe our findings can contribute to the growing field of computer vision for the study and understanding of animal behavior.
The insulating activity of the Drosophila BX-C chromatin boundary Fub-1 is parasegmentally regulated by lncRNA read-through

Though long non-coding RNAs (lncRNAs) represent a substantial fraction of the Pol II transcripts in multicellular animals, only a few have known functions. Here we report that the blocking activity of the Bithorax complex (BX-C) Fub-1 boundary is segmentally regulated by its own lncRNA. The Fub-1 boundary is located between the Ultrabithorax (Ubx) gene and the bxd/pbx regulatory domain, which is responsible for regulating Ubx expression in parasegment PS6/segment A1. Fub-1 consists of two hypersensitive sites, HS1 and HS2. HS1 is an insulator while HS2 functions primarily as a lncRNA promoter. To activate Ubx expression in PS6/A1 enhancers in the bxd/pbx domain must be able to bypass Fub-1 blocking activity. We show that expression of the Fub-1 lncRNAs in PS6/A1 from the HS2 promoter inactivates Fub-1 insulating activity. Inactivation is due to readthrough as the HS2 promoter must be directed towards HS1 to disrupt blocking.
The microbial composition and functional roles of different kombucha products in Singapore

Kombucha is a fermented tea traditionally known for its health-enhancing properties owing to the bioactive compounds generated by acetic acid bacteria (AAB) and lactic acid bacteria (LAB). We compared the distribution of AAB and LAB and their functional pathways across nine commercial kombucha products in Singapore using shotgun metagenomic sequencing. A high prevalence of Komagataeibacter species including Komagataeibacter saccharivorans (82.93% in B), Komagataeibacter xylinus (93.38% in D) and Komagataeibacter rhaeticus (92.20% and 30.62% in G and I) was detected in AAB-dominant kombucha. LAB-dominant kombucha was largely represented by Bacillus coagulans (~99% in E and F) and Lactobacillus nagelii (~60% in H). Despite differences in bacterial composition, both LAB-and AAB-dominant kombucha harbour pathways involved in the biosynthesis of short-chain fatty acids (SCFAs), amino and organic acids and vitamin B12. “Fatty acid and beta-oxidation II (peroxisome)” and “fatty acid and beta-oxidation I” were detected in the LAB but not the AAB-dominant kombucha.
An RNA Interference (RNAi) Toolkit and Its Utility for Functional Genetic Analysis of Leishmania (Viannia)

RNA interference (RNAi) is a powerful tool whose efficacy against a broad range of targets enables functional genetic tests individually or systematically. However, the RNAi pathway has been lost in evolution by a variety of eukaryotes including most Leishmania sp. RNAi was retained in species of the Leishmania subgenus Viannia, and here we describe the development, optimization, and application of RNAi tools to the study of L. (Viannia) braziliensis. We developed vectors facilitating generation of long-hairpin or “stem-loop” (StL) RNAi knockdown constructs, using Gateway™ site-specific recombinase technology. A survey of applications of RNAi in L. braziliensis included genes interspersed within multigene tandem arrays such as QDPR, a potential target or modulator of antifolate sensitivity. Other tests include genes involved in cell differentiation and amastigote proliferation (A600), and essential genes of the intraflagellar transport (IFT) pathway. We tested a range of stem lengths targeting the L. braziliensis hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and reporter firefly luciferase (LUC) genes and found that the efficacy of RNAi increased with stem length, and fell off greatly below about 128 nt. We used the StL length dependency to establish a useful ‘hypomorphic’ approach not possible with other gene ablation strategies, with shorter IFT140 stems yielding viable cells with compromised flagellar morphology. We showed that co-selection for RNAi against adenine phosphoryl transferase (APRT1) using 4-aminopyrazolpyrimidine (APP) could increase the efficacy of RNAi against reporter constructs, a useful tool that may facilitate improvements in future work. Thus, for many genes, RNAi provides a useful tool for studying Leishmania gene function with some unique advantages.
Selective control of synaptic plasticity in heterogeneous networks through transcranial alternating current stimulation (tACS)

Transcranial alternating current stimulation (tACS) represents a promising non-invasive treatment for an increasingly wide range of neurological and neuropsychiatric disorders. The ability to use periodically oscillating electric fields to non-invasively engage neural dynamics opens up the possibility of recruiting synaptic plasticity and to modulate brain function. However, despite consistent reports about tACS clinical effectiveness, strong state-dependence combined with the ubiquitous heterogeneity of cortical networks collectively results in high outcome variability. Introducing variations in intrinsic neuronal timescales, we explored how such heterogeneity influences stimulation-induced change in synaptic connectivity. We examined how spike timing dependent plasticity, at the level of cells, intra- and inter-laminar cortical networks, can be selectively and preferentially engaged by periodic stimulation. Using computational simulations informed by human experimental data, we analyzed cortical circuits comprised of multiple cell-types, alongside superficial multi-layered networks expressing distinct layer-specific timescales. Our results show that mismatch in neuronal timescales within and/or between cells - and the resulting variability in excitability, temporal integration properties and frequency tuning - enables selective and directional control on synaptic connectivity by tACS. Our work provides new vistas on how to recruit neural heterogeneity to guide brain plasticity using non-invasive stimulation paradigms. Author summary Brain stimulation techniques, such as transcranial alternating current stimulation (tACS), are increasingly used to treat mental health disorders and to probe brain function. Despite promising results, it remains unclear how these non-invasive interventions impact both the dynamics and connectivity of neural circuits. We developed an interdisciplinary framework showing that heterogeneity in neuronal timescales, and its consequences on cellular excitability and temporal integration properties of cortical neurons, may lead to selective and directional control on synaptic modifications by tACS. Differences in neuron responses resulting from timescale mismatch establishes phase- and frequency-specific tuning relationships which may be recruited by periodic stimuli to guide synaptic plasticity. We confirmed this using both intra - and inter-laminar cortical circuit models comprised of multiple cell-types and informed by experimental data. Our work showcases how heterogeneity might be used to guide synaptic plasticity using non-invasive stimulation paradigms.
Alpha closed-loop auditory stimulation modulates waking alpha oscillations and sleep onset dynamics in a phase-dependent manner in humans

Alpha oscillations play a vital role in managing the brain’s resources, inhibiting neural activity as a function of their phase and amplitude, and are changed in many brain disorders. Developing minimally invasive tools to modulate alpha activity and identifying the parameters that determine its response to exogenous modulators, is essential for the implementation of focussed interventions. We introduce Alpha Closed-Loop Auditory Stimulation (αCLAS) as an EEG-based method to augment and investigate these brain rhythms in humans with specificity and selectivity, using targeted auditory stimulation. Across three independent studies, we demonstrate that αCLAS alters alpha power, frequency, and connectivity in a phase, amplitude and topography-dependent manner. Using a single-pulse-αCLAS evoked potentials approach we show that the effects of auditory stimuli on alpha oscillations and resulting evoked potentials can be explained within the theoretical framework of oscillator theory and a phase-reset mechanism. Finally, we demonstrate the functional relevance of our approach by showing that αCLAS modulates sleep onset dynamics in an alpha phase-dependent manner.
Exploring the distribution of phylogenetic networks generated under a birth-death-hybridization process

Gene-flow processes such as hybridization and introgression play important roles in shaping diversity across the tree of life. Recent studies extending birth-death models have made it possible to investigate patterns of reticulation in a macroevolutionary context. These models allow for different macroevolutionary patterns of gene flow events that can either add, maintain, or remove lineages—with the gene flow itself possibly being dependent on the relatedness between species—thus creating complex diversification scenarios. Further, many reticulate phylogenetic inference methods assume specific reticulation structures or phylogenies belonging to certain network classes. However, the distributions of phylogenetic networks under reticulate birth-death processes are poorly characterized, and it is unknown whether they violate common methodological assumptions. We use simulation techniques to explore phylogenetic network space under a birth-death-hybridization process where the hybridization rate can have a linear dependence on genetic distance. Specifically, we measured the number of lineages through time and role of hybridization in diversification along with the proportion of phylogenetic networks that belong to commonly used network classes (e.g., tree-child, tree-based, or level-1 networks). We find that the growth of phylogenetic networks and class membership are largely affected by assumptions about macroevolutionary patterns of gene flow. In accordance with previous studies, a lower proportion of networks belonged to these classes based on type and density of reticulate events. However, under a birth-death-hybridization process, these factors form an antagonistic relationship; the type of reticulation events that cause high membership proportions also lead to the highest reticulation density, consequently lowering the overall proportion of phylogenies in some classes. Further, we observed that genetic distance–dependent gene flow and incomplete sampling increase the proportion of class membership, primarily due to having fewer reticulate events. Our results can inform studies if their biological expectations of gene flow are associated with evolutionary histories that satisfy the assumptions of current methodology and aid in finding phylogenetic classes that are relevant for methods development.
Semiconductor plasmonic nanodisk laser: simulation and design

An effective simulation and design platform is presented in this paper for semiconductor plasmonic nanodisk laser. The three-dimensional laser structure is modeled and simulated with a body-of-revolution finite-difference-timedomain (BOR-FDTD) combined with the multi-level gain medium model and the Drude-Lorentz metal model, which gives a comprehensive spatial and temporal electromagnetic simulation of the nano-cavity and its lasing performance above the threshold. A semiconductor plasmonic nano-disk laser embedded in silver film is designed and the spatial and temporal lasing performance is numerically demonstrated. The physical volume of the nanodisk laser is only 1.17 (λ/2n)3 (a diameter of 200 nm and a height of 300 nm) and it has lasing wavelength at 1400 nm with a pumping threshold of 0.4 μW.
The GxcM-Fbp17/RacC-WASP signaling cascade regulates polarized cortex assembly in migrating cells

The actin-rich cortex plays a fundamental role in many cellular processes. Its architecture and molecular composition vary across cell types and physiological states. The full complement of actin assembly factors driving cortex formation and how their activities are spatiotemporally regulated remain to be fully elucidated. Using Dictyostelium as a model for polarized and rapidly migrating cells, we show that GxcM, a RhoGEF localized specifically in the rear of migrating cells, functions together with F-BAR protein Fbp17, a small GTPase RacC, and the actin nucleation-promoting factor WASP to coordinately promote Arp2/3 complex-mediated cortical actin assembly. Over-activation of this signaling cascade leads to excessive actin polymerization in the rear cortex, whereas its disruption causes defects in cortical integrity and function. Therefore, different from its well-defined role in the formation of the front protrusions, the Arp2/3 complex-based actin carries out a previously unappreciated function in building the rear cortical subcompartment in rapidly migrating cells.
Integral Field Near-Infrared Spectroscopy of a Sample of Seyfert and LINER Galaxies. I. The Data

We present near-IR integral field spectroscopy of a sample of 31 Seyfert and LINER galaxies which were selected both to span a wide range of nuclear magnitudes and to possess roughly equal numbers of Seyfert type 1 and 2 nuclei. Moderate resolution (R ~ 1000; R ~ 2000 for three cases) integral field K-band spectra were obtained for all 31 galaxies in our sample and for 18 galaxies (R ~ 1000; R ~ 2000 for four cases) H-band integral field spectra were also obtained. In each case, we present nuclear, larger aperture, and difference spectra with corresponding information about emission line wavelengths, fluxes, and widths. Line-free H- and K-band continuum images as well as [Fe II] λ1. 644 μm, Brγ, and H2 1-0 S(1) emission lines are also presented. In addition, we provide extensive information about each galaxy obtained from the literature that will be useful subsequently for characterizing the sample and for comparison with our near-IR data.
Geometrical effects of distributed attached mass on the natural frequency of thick cylindrical and spherical shells using higher-order theory

In this study, free vibrations of thick composite cylindrical and spherical shell panels with uniformly distributed attached masses were analyzed, using the standard Galerkin procedure. The stiffness effect of the distributed attached mass was taken into account for the first time, and the results were compared with well-known published results for which this effect was not considered. Various results for effects such as thickness, radii of curvature, and elasticity moduli are presented in this paper. Mass inertia of the distributed attached mass decreased the natural frequencies of the system, while the stiffness effect increased these values.
Magnetotransport properties and giant anomalous Hall angle in the half-Heusler compound TbPtBi

Magnetic lanthanide half-Heuslers ($R$PtBi; $R$ being the lanthanide) represent an attractive subgroup of the Heusler family and have been identified as ideal candidates for time reversal symmetry breaking topological Weyl semimetals. In this paper, we present the detailed analysis of the magnetotransport properties of frustrated antiferromagnet TbPtBi. This material shows large, non-saturating magnetoresistance (MR) with unusual magnetic field dependence. The MR of TbPtBi is significantly anisotropic with respect to the magnetic field, applied along different crystallographic directions and indicates the anisotropic nature of the Fermi surface. The chiral anomaly induced negative longitudinal magnetoresistance confirms the presence of Weyl fermions. At low temperature, Berry phase driven large anomalous Hall conductivity has been observed. The calculated anomalous Hall angle is the largest reported so far.
The Search for an Atmospheric Signature of the Transiting Exoplanet HD 149026b

HD 149026b is a short‐period, Saturn‐mass planet that transits a metal‐rich star. The planet's radius, determined by photometry, is remarkably small compared to other known transiting planets, with a heavy‐element core that apparently comprises ∼70% of the total planet mass. Time‐series spectra were obtained at Keck before and during transit in order to model the Rossiter‐McLaughlin effect. Here we make use of these observations to carry out a differential comparison of spectra obtained in and out of transit to search for signatures of neutral atomic lithium and potassium from the planet atmosphere. No signal was detected at the 2% level; we therefore place upper limits on the column density of these atoms.
Business Model Evaluation: A Systematic Review of Methods

Background: As a result of factors such as digitization and rapid technology change, organizations are compelled to innovate their business models at an accelerated pace. While the domain of business model innovation has focused on understanding and structuring the process of innovation, it offers limited guidance for evaluating business models during the innovation process. Business model evaluation plays a vital role in supporting decision-making about the performance or viability of new business models and motivating continued investments. Existing literature on methods for business model evaluation and their application is limited and available information is scattered. Furthermore, as the BMI process covers a broad spectrum of activities - from business model initiation to implementation - the evaluation challenges and the effectiveness of evaluation methods vary across the phases of innovation. Thus, there is a need for a better understanding on methods for business model evaluation, and their timing and application for business model innovation. Method: Through a systematic literature review, we have investigated the methods available for business model evaluation and focused on understanding their characteristics and effective timing of application in the business model innovation process. Results: We have identified six groups of methods used for business model evaluation. Additionally, we find that early phase business model evaluation is predominantly qualitative in nature, whereas late phases of business model innovation are generally supported through quantitatively-oriented methods. Moreover, we observe that limited evaluation support is available in the literature to support the initiation phase of business model innovation. Based on our findings, we propose a guiding structure for aligning the available methods with the respective innovation phases. Conclusion: The proposed guiding structure offers guidance for business model evaluation in practice and serves as a basis for future research in developing more effective methods and tools for business model evaluation and development.
ALMA Detection of Bipolar Outflows: Evidence for Low-mass Star Formation within 1 pc of Sgr A*

We report the discovery of 11 bipolar outflows within a projected distance of 1 pc from Sgr A* based on deep ALMA observations of 13CO, H30α, and SiO (5−4) lines with subarcsecond and ∼1.3 km s−1 resolutions. These unambiguous signatures of young protostars manifest as approaching and receding lobes of dense gas swept up by the jets created during the formation and early evolution of stars. The lobe masses and momentum transfer rates are consistent with young protostellar outflows found throughout the disk of the Galaxy. The mean dynamical age of the outflow population is estimated to be years. The rate of star formation is ∼5 × 10−4 yr−1 assuming a mean stellar mass of ∼0.3 . This discovery provides evidence that star formation is taking place within clouds surprisingly close to Sgr A*, perhaps due to events that compress the host cloud, creating condensations with sufficient self-gravity to resist tidal disruption by Sgr A*. Low-mass star formation over the past few billion years at this level would contribute significantly to the stellar mass budget in the central few parsecs of the Galaxy. The presence of many dense clumps of molecular material within 1 pc of Sgr A* suggests that star formation could take place in the immediate vicinity of supermassive black holes in the nuclei of external galaxies.
DECAY PROPERTIES OF THE FINITE-TEMPERATURE DENSITY MATRIX IN METALS

Using ordinary Fourier analysis, the asymptotic decay behavior of the density matrix ${F(r,r}^{\ensuremath{'}})$ is derived for the case of a metal at a finite electronic temperature. An oscillatory behavior that is damped exponentially with increasing distance between $r$ and ${r}^{\ensuremath{'}}$ is found. The decay rate is not only determined by the electronic temperature, but also by the Fermi energy. The theoretical predictions are confirmed by numerical simulations.
Tests of Gravity with Galaxy Clusters

Changes in the law of gravity have far-reaching implications for the formation and evolution of galaxy clusters, and appear as peculiar signatures in their mass-observable relations, structural properties, internal dynamics, and abundance. We review the outstanding progress made in recent years towards constraining deviations from General Relativity with galaxy clusters, and give an overview of the yet untapped information becoming accessible with forthcoming surveys that will map large portions of the sky in great detail and unprecedented depth.