Miracle-dz/UniFAR-FTUs huggingface dataset:
Suppressing feedback signals to visual cortex abolishes attentional modulation

Attention improves perception by enhancing the neural encoding of sensory information. A long-standing hypothesis is that cortical feedback projections carry top-down signals to influence sensory coding. However, this hypothesis has never been tested to establish causal links. We used viral tools to label feedback connections from cortical area V4 targeting early visual cortex (area V1). While monkeys performed a visual–spatial attention task, inactivating feedback axonal terminals in V1 without altering local intracortical and feedforward inputs reduced the response gain of single cells and impaired the accuracy of neural populations for encoding external stimuli. These effects are primarily manifested in the superficial layers of V1 and propagate to downstream area V4. Attention enhances sensory coding across visual cortex by specifically altering the strength of corticocortical feedback in a layer-dependent manner. Description Attention alters cortical feedback The neural underpinnings of attention are still incompletely understood. Debes and Dragoi present causal evidence that the attentional modulation of individual neurons and cell populations is performed by cortical feedback projections. Suppressing cortical area V4 feedback axons to area V1 without altering local and feedforward intracortical inputs virtually abolished the attention-induced benefits on response gain, the accuracy of network computations, and the attentional modulation of postsynaptic area V4 neuron responses. These findings indicate that feedback signals modulate visual cortical responses only when stimuli are attended. Because feedback has been hypothesized to control other top-down processes, these results could have implications for a broad range of phenomena across many modalities. —PRS Feedback projections in the primate visual system convey attention-related modulation of neuronal firing activity.
Northern Yellow Bat Dasypterus intermedius Activity and Habitat Selection on an Atlantic Barrier Island

Knowledge and understanding of bat activity and habitat associations are important for effective conservation and management, especially in landscapes undergoing land use changes. Dasypterus intermedius (northern yellow bat), a broadly distributed species in the Coastal Plain of the southeastern United States, is a species of conservation concern due to habitat loss. We examined the influence of landscape factors on D. intermedius activity on Little Saint Simons Island (LSSI), Georgia, USA, an Atlantic barrier island characterized by a limited human disturbance history. From April to October 2013, we recorded a total of 6,921 D. intermedius passes and 138 feeding buzzes among six land cover types across three biologically relevant seasons. We used GLMMs to model total and foraging activity using landscape variables and season as covariates. We found no significant differences in total activity among cover types, but observed a clear pattern of greater activity in cover types with low vegetation clutter. We observed significantly greater total activity later in the year after juveniles became volant and were able to forage on their own. Based on feeding buzzes, our results demonstrated greater foraging activity in maritime grasslands than in the oak and pine cover types. Distance to water, edge, and roosting habitat had little influence on total or foraging activity. Our results provide baseline information regarding D. intermedius habitat use from a relatively undisturbed coastal environment that can aid management decisions when considering bats in landscapes experiencing changes from development.
Molecular Characterization and Morpho-Taxonomy of Gambierdiscus caribaeus Vandersea, Litaker, M.A.Faust, Kibler, W.C.Holland & P.A.Tester (Dinophyceae) from Mauritius Island, South-West Indian Ocean

ABSTRACT Species of the marine benthic dinoflagellate genus Gambierdiscus Adachi & Fukuyo are morphologically similar, and DNA based sequence analyses are necessary to complement morphological species determination. Gambierdiscus species may produce ciguatoxins, the causative agents of human illness ciguatera poisoning (CP). In this study, morphological descriptions, based on laboratory cultures, using light and scanning electron microscopy and DNA based characterisation of one strain (ISOG4) isolated from Petite Rivière Noire, Mauritius are provided. Our morphological observations coupled with DNA based sequence analyses indicate that the Mauritian strain is Gambierdiscus caribaeus Vandersea, Litaker, M.A.Faust, Kibler, W.C. Holland & P.A. Tester. Our strain bears close similarity (LSU 99% identity) to Gambierdiscus caribaeus (GenBank[KY448444]) isolated from Canary Islands, Spain, and phylogenetic results depict it as sister to G. jejuensis S.H.Jang & H.J.Jeong. Gambierdiscus caribaeus (ISOG4) is herein a first report from Mauritius Island and the Mascarene region. RÉSUMÉ Caractérisation moléculaire et morpho-taxonomie de Gambierdiscus caribaeus Vandersea, Litaker, M.A.Faust, Kibler, W.C. Holland & P.A. Tester (Dinophyceae) de l'île Maurice, sud-ouest de l'océan Indien. Les espèces du genre de dinoflagellés benthiques marins Gambierdiscus Adachi & Fukuyo sont morphologiquement similaires, et des analyses de séquences basées sur l'ADN sont nécessaires pour compléter la détermination morphologique des espèces. Les espèces de Gambierdiscus peuvent produire des ciguatoxines, agents responsables de la maladie humaine qu'est la ciguatera (CP). Dans cette étude, des descriptions morphologiques, basées sur des cultures en laboratoire, réalisées par microscopie optique et électronique à balayage, et une caractérisation basée sur l'ADN d'une souche (ISOG4) isolée de Petite Rivière Noire, Maurice sont fournies. Nos observations morphologiques couplées aux analyses de séquences basées sur l'ADN indiquent que la souche mauricienne est Gambierdiscus caribaeus Vandersea, Litaker, M.A.Faust, Kibler, W.C. Holland & P.A. Tester. Notre souche est très similaire (LSU 99 %) à Gambierdiscus caribaeus (GenBank[KY448444]) isolé des îles Canaries, Espagne, et les résultats phylogénétiques la décrivent comme sœur de G. jejuensis S.H.Jang & H.J.Jeong. Gambierdiscus caribaeus (ISOG4) est ici signalé pour la première fois à l'île Maurice et dans la région des Mascareignes.
Orbital Dynamics of Space Vehicles

THE PROBLEMS of mass transfer have long been the concern of chemical engineers who have developed an extensive theory of such transfer processes. In recent years however, important applications have been discussed in other areas, notably in highspeed aircraft and rocket propulsion, combustion processes generally, and in the heating problems associated with high-speed flight. The methods used in these various areas have developed along slightly different lines, with different assumptions appropriate to the conditions encountered, and Professor Spalding's book provides a very welcome unified account of the whole theory of mass transfer, which will be suitable for engineers working in any of the fields in which mass transfer processes occur. As the author points out, specialists in particular fields may find the notation unfamiliar and apparently clumsy, but this is a small penalty to be weighed against the valuable simplifications arising from the use of single set of concepts applicable to all mass transfer problems. The level of mathematical knowledge demanded of the reader is not high and, as the author says, this has restricted the completeness of the derivation of formulae and the range of practical problems considered. However a later volume is promised in which the theoretical foundations of the subject will be firmly laid and, as far as practical problems are concerned, the present volume covers a wide enough field, presenting methods of calculation appropriate to absorption processes, transpiration cooling, simple combustion processes, and cooling tower design.
High‐quality 4H‐SiC homoepitaxial layers grown by step‐controlled epitaxy

4H‐SiC bulk crystals were grown controllably by means of a modified Lely method. Homoepitaxial growth of 4H‐SiC was carried out by vapor phase epitaxy utilizing step‐controlled epitaxy on 4H‐SiC substrates prepared by the modified Lely method. The physical properties (electrical and optical properties) of 4H‐SiC epilayers were characterized by Hall effects and photoluminescence (PL) measurements. The electron mobilities as high as 720 cm2/V s at 292 K, and 11 000 cm2/V s at 77 K were obtained. In the PL measurement, the epilayers with a thickness more than 20 μm showed luminescence attributed to free exciton recombination, which indicates the improvement of crystal quality by step‐controlled epitaxy.
IMeP: Impedance Matching Enhanced Power-Delivered-to-Load Optimization for Magnetic MIMO Wireless Power Transfer System

Recently, multiple-input multiple-output (MIMO) technology has been introduced into magnetic resonant coupling (MRC) enabled wireless power transfer (WPT) systems for concurrent charging of multiple devices. However, impedance mismatching phenomena caused by strong TX-RX, TX-TX, or RX-RX coupling greatly affect the power delivered to load (PDL) in practical charging systems. To solve this issue, we propose an effective scheduling algorithm for Impedance Matching–enhanced PDL optimization in MIMO MRC-WPT systems (called IMeP), which integrates the transmitter scheduling together with the impedance matching techniques, i.e., adjusting TX coils for tuning TX-RX/TX-TX coupling and grouping RXs to separate strongly coupled RX pairs. We formulate this as a joint optimization problem and decouple it into three sub-problems, i.e., current scheduling, coil adjustment, and RX grouping. We then solve them through alternating direction method of multipliers–based, randomized beamforming–based, and graph clique cover–based algorithms, respectively. Extensive experiments are performed on a prototype testbed, and the results demonstrate the effectiveness of our solution. Compared with the state-of-the-art power transfer efficiency maximization solution, the proposed algorithm IMeP achieves a 74.7× performance improvement of PDL on average.
Polypharmacology-based kinome screen identifies new regulators of KSHV reactivation

Kaposi’s sarcoma-associated herpesvirus (KSHV) causes several human diseases including Kaposi’s sarcoma (KS), a leading cause of cancer in Africa and in patients with AIDS. KS tumor cells harbor KSHV predominantly in a latent form, while typically <5% contain lytic replicating virus. Because both latent and lytic stages likely contribute to cancer initiation and progression, continued dissection of host regulators of this biological switch will provide insights into fundamental pathways controlling the KSHV life cycle and related disease pathogenesis. Several cellular protein kinases have been reported to promote or restrict KSHV reactivation, but our knowledge of these signaling mediators and pathways is incomplete. We employed a polypharmacology-based kinome screen to identifiy specific kinases that regulate KSHV reactivation. Those identified by the screen and validated by knockdown experiments included several kinases that enhance lytic reactivation: ERBB2 (HER2 or neu), ERBB3 (HER3), ERBB4 (HER4), MKNK2 (MNK2), ITK, TEC, and DSTYK (RIPK5). Conversely, ERBB1 (EGFR1 or HER1), MKNK1 (MNK1) and FRK (PTK5) were found to promote the maintenance of latency. Mechanistic characterization of ERBB2 pro-lytic functions revealed a signaling connection between ERBB2 and the activation of CREB1, a transcription factor that drives KSHV lytic gene expression. These studies provided a proof-of-principle application of a polypharmacology-based kinome screen for the study of KSHV reactivation and enabled the discovery of both kinase inhibitors and specific kinases that regulate the KSHV latent-to-lytic replication switch. Author Summary Kaposi’s sarcoma-associated herpesvirus (KSHV) causes Kaposi’s sarcoma, a cancer particularly prevalent in Africa. In cancer cells, the virus persists in a quiescent form called latency, in which only a few viral genes are made. Periodically, the virus switches into an active replicative cycle in which most of the viral genes are made and new virus is produced. What controls the switch from latency to active replication is not well understood, but cellular kinases, enzymes that control many cellular processes, have been implicated. Using a cell culture model of KSHV reactivation along with an innovative screening method that probes the effects of many cellular kinases simultaneously, we identified drugs that significantly limit KSHV reactivation, as well as specific kinases that either enhance or restrict KSHV replicative cycle. Among these were the ERBB kinases which are known to regulate growth of cancer cells. Understanding how these and other kinases contribute to the switch leading to production of more infectious virus helps us understand the mediators and mechanisms of KSHV diseases. Additionally, because kinase inhibitors are proving to be effective for treating other diseases including some cancers, identifying ones that restrict KSHV replicative cycle may lead to new approaches to treating KSHV-related diseases.
Gnotobiotic zebrafish microbiota display inter-individual variability affecting host physiology

Gnotobiotic animal models reconventionalized under controlled laboratory conditions with multi-species bacterial communities are commonly used to study host-microbiota interactions under presumably more reproducible conditions than conventional animals. The usefulness of these models is however limited by inter-animal variability in bacterial colonization and our general lack of understanding of the inter-individual fluctuation and spatio-temporal dynamics of microbiota assemblies at the micron to millimeter scale. Here, we show underreported variability in gnotobiotic models by analyzing differences in gut colonization efficiency, bacterial composition, and host intestinal mucus production between conventional and gnotobiotic zebrafish larvae re-conventionalized with a mix of 9 bacteria isolated from conventional microbiota. Despite similar bacterial community composition, we observed high variability in the spatial distribution of bacteria along the intestinal tract in the reconventionalized model. We also observed that, whereas bacteria abundance and intestinal mucus per fish were not correlated, reconventionalized fish had lower intestinal mucus compared to conventional animals, indicating that the stimulation of mucus production depends on the microbiota composition. Our findings, therefore, suggest that variable colonization phenotypes affect host physiology and impact the reproducibility of experimental outcomes in studies that use gnotobiotic animals. This work provides insights into the heterogeneity of gnotobiotic models and the need to accurately assess re-conventionalization for reproducibility in host-microbiota studies.
Bacterial Microbiota of Ostreobium, the Coral-Isolated Chlorophyte Ectosymbiont, at Contrasted Salinities

Microscopic filaments of the siphonous green algae Ostreobium (Ulvophyceae, Bryopsidales) colonize and dissolve the calcium carbonate skeletons of coral colonies, in shallow-water reef environments of contrasted salinities. Their bacterial composition and plasticity in response to salinity remain unknown. Here, we analyzed the bacteria associated with coral-isolated Ostreobium strains from two distinct rbcL lineages, representative of IndoPacific environmental phylotypes, that had been pre-acclimatized (>9months) to three ecologically-relevant reef salinities: 32.9, 35.1 and 40.2 psu. Bacterial phylotypes were visualized at filament scale by CARD-FISH in algal tissue sections, localized to the surface, within filaments or in the algal mucilage. Ostreobium-associated communities, characterized by bacterial 16S rRNA metabarcoding of cultured thalli and corresponding supernatants, were structured by host genotype more than salinity and partly overlapped with those of environmental (Ostreobium-colonized) coral skeletons. Alphaproteobacteria dominated the thalli communities, enriched in Kiloniellaceae or Rhodospirillaceae depending on algal genotype. A small core microbiota composed of 7 ASVs (∼1.5% of thalli ASVs, 19%-36% cumulated proportions), shared by multiple cultures of both Ostreobium genotypes and persistent across 3 salinities, included putative intracellular Amoebophilus and Rickettsiales bacteria. This novel knowledge on the taxonomic diversity of Ostreobium bacterial associates paves the way to functional interaction studies within the coral holobiont.
Genetic control of mRNA splicing as a potential mechanism for incomplete penetrance of rare coding variants

Exonic variants present some of the strongest links between genotype and phenotype. However, these variants can have significant inter-individual pathogenicity differences, known as variable penetrance. In this study, we propose a model where genetically controlled mRNA splicing modulates the pathogenicity of exonic variants. By first cataloging exonic inclusion from RNA-seq data in GTEx v8, we find that pathogenic alleles are depleted on highly included exons. Using a large-scale phased WGS data from the TOPMed consortium, we observe that this effect may be driven by common splice-regulatory genetic variants, and that natural selection acts on haplotype configurations that reduce the transcript inclusion of putatively pathogenic variants, especially when limiting to haploinsufficient genes. Finally, we test if this effect may be relevant for autism risk using families from the Simons Simplex Collection, but find that splicing of pathogenic alleles has a penetrance reducing effect here as well. Overall, our results indicate that common splice-regulatory variants may play a role in reducing the damaging effects of rare exonic variants.
Delayed normalization model captures disparate nonlinear neural dynamics measured with different techniques in macaque and human V1

Neuronal representations throughout the primate visual system display a wide range of nonlinear dynamics in response to static visual stimuli. To understand the neural basis of visual perception, it is important to quantify these nonlinearities and to develop general models that allow one to predict response dynamics to visual stimuli with arbitrary temporal waveform. Voltage-sensitive dye imaging (VSDI) is a powerful method for measuring neural population responses from the cortex of awake, behaving, subjects. Here we used VSDI to measure the dynamics of neural population responses in macaque V1 to visual stimuli with a wide range of time courses. We found that beyond clear nonlinearities for briefly presented visual stimuli, stimulus-evoked VSDI responses are surprisingly near additive in time. These results are qualitatively different from neural dynamics to similar stimuli previously measured in human visual cortex using fMRI and electrocorticography (ECoG), which show strong sub-additivity in time. To test whether this discrepancy is specific to VSDI, a signal dominated by subthreshold neural activity, we repeated our measurements using a genetically encoded calcium indicator (GCaMP), a signal dominated by spiking activity. We found that GCaMP signals in macaque V1 are also near-additive. Therefore, the discrepancies in the degree of additivity between these different measurements are not attributed to the difference between sub- and supra-threshold neural response. Finally, we show that a simple yet flexible delayed normalization model can capture the dynamics of all of these measurements, suggesting that dynamic gain-control is an important mechanism contributing to neural processing in the brain.
Single-crystal Mössbauer study of phlogopite mica

In this first single-crystal Mossbauer study of mica we have measured the room-temperature spectra for different orientations (with respect to the -γ-ray flux) of a well-characterized monocrystalline wafer of natural phlogopite. We apply a new method (D. G. Rancourt, Nucl. Instrum. Methods Phys. Res. B44, 199 (1989). of performing thickness corrections, which yields the intrinsic absorber cross section. The simplest physical model that is consistent with all the spectra is described as follows. The Fe2+ spectral contribution is due to correlated distributions of hyperfine electric-field gradient (efg) magnitudes and directions that can be understood in terms of two families of octahedral sites: a cis-like family having a narrower distribution of larger efg magnitudes and directions in the ab-plane and probably along the b axis, and a trans-like defect family having a broader distribution of smaller efg magnitudes and more out-of-plane efg directions. The Fe3+ spectral component is also due to broad and co.
Dynamic Complexity of Regular Languages: Big Changes, Small Work

Whether a changing string is member of a certain regular language can be maintained in the DynFO framework of Patnaik and Immerman: after changing the symbol at one position of the string, a first-order update formula can express – using additionally stored information – whether the resulting string is in the regular language. We extend this and further known results by considering changes of many positions at once. We also investigate to which degree the obtained update formulas imply work-efficient parallel dynamic algorithms.
Neutron-induced noise in National Ignition Facility-class diagnostic instruments

Neutron yields from deuterium–tritium-filled inertial-confinement-fusion targets have reached 1014. Above 1013, a significant neutron-induced background appears in images recorded with nearby streak cameras. Since camera components (streak tube, image-intensifier tube, and charge coupled device arrays) are similar to components that will be used in many National Ignition Facility (NIF) instruments, streak camera images provide information about neutron-induced backgrounds that will be encountered in the NIF environment. At a fluence of 107 neutrons/cm2, the background consists of two distinct components: a uniform component equal to nearly 20% of the camera’s linear range and sharp, intense spikes each localized to just a couple of image pixels. About 80% of the uniform background is caused by interactions with the streak tube and image-intensifier tube. Nearly all the sharp spikes are caused by interactions with pixels of the charged-coupled device array. The spikes make the most significant contribution.
Dispersion of phonon-assisted nonresonant third-order nonlinearities

An analysis of the dispersion of two-photon absorption and Kerr nonlinearity of indirect semiconductors below the indirect bandgap is presented. Similar to the case of linear absorption, third-order nonlinear processes are found to be mediated by phonon-assisted transitions. The Kerr coefficient n/sub 2/ is positive below the indirect gap, and the dispersion of the third-order nonlinearities is reduced relative to direct semiconductors. The results are compared with existing experimental data in silicon.