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Extracting probability in the absence of visual awareness
No full textExtracting statistical regularities from the environment is crucial for survival. It allows us to learn cues for where and when future events will occur. Can we learn these associations even when the cues are not consciously perceived? Can these unconscious processes integrate information over long periods of time? We show that human visual system can track the probability of location contingency between an unconscious prime and a conscious target over a period of time of minutes. In a series of psychophysical experiments, we adopted an exogenous priming paradigm and manipulated the location contingency between a masked prime and a visible target (i.e., how likely the prime location predicted the target location). The prime’s invisibility was verified both subjectively and objectively. Although the participants were unaware of both the existence of the prime and the prime-target contingency, our results showed that the probability of location contingency was tracked and manifested in the subsequent priming effect. When participants were first entrained into the fully predictive prime-target probability, they exhibited faster responses to the more predictive location. On the contrary, when no contingency existed between the prime and target initially, participants later showed faster responses to the less predictive location. These results were replicated in two more experiments with increased statistical power and a fine-grained delineation of prime awareness. Together, we report that the human visual system is capable of tracking unconscious probability over a period of time, demonstrating how implicit and uncertain regularity guides behavior
Coherent tracer correlations in deep-sea corals and implications for biomineralization mechanisms underlying vital effects
No full textDeep-sea corals are a useful archive of thermocline, intermediate, and deep waters in past oceans. However, application of traditional oceanographic tracers to deep-sea corals remains a challenge due to our insufficient understanding of their “vital effects”. Deep-sea corals are ideal test organisms to study the mechanism underlying vital effects generally, due to the large tracer gradients in individual corals living under relatively constant environmental conditions. Lessons learned from these corals might apply to other scleractinia and to marine calcifiers more generally. Here we present stable isotope, minor and trace metal (Me/Ca ratios) data in a suite of modern Desmophyllum dianthus specimens, collected over multiple spatial scales in individual corals (bulk, micromill, SIMS, NanoSIMS), with multi-proxy analyses made on the same material whenever possible. Spatially coherent Me/Ca correlations are observed in the fibrous aragonite of individual corals, including positive correlations between Mg/Ca, Li/Ca and B/Ca, as well as negative correlations between Mg/Ca and Sr/Ca, consistent with previous studies. We also for the first time document strong correlations between the isotopic (δ¹⁸O and δ¹³C) and elemental compositions of the skeletons, most notably a negative correlation between δ¹⁸O and Mg/Ca. The centers of calcification (COCs) in the coral skeletons show distinct tracer correlations from the aragonite fibers that possibly reflect a more complicated formation mechanism. We interpret the spatially coherent tracer correlations in deep-sea corals with a numerical model of coral calcification previously developed for stable isotopes that considers the role of the enzyme carbonic anhydrase in the calcification processs. With the carbonate chemistry in the model constrained by the stable isotope data, we are able to explain the observed Me/Ca correlations as well as their range of variability, as a result of internal pH elevation in the extracellular calcifying fluid (ECF) of the corals with limited Ca-pumping through the calicoblastic membrane. In particular, the positive Mg/Ca–B/Ca correlation in the fibrous aragonite suggests a borate (B(OH)₄–) substitution for carbonate ion (CO₃²⁻) incorporation mechanism in biogenic aragonite. We also suggest the growth rate dependence of the incorporation of minor and trace elements based conceptually on an ion-by-ion growth model may help explain the absolute Me/Ca values in biogenic aragonites. Finally, we generally find more limited tracer variability in corals from undersaturated seawater compared to their counterparts from supersaturated conditions, suggesting a limit to their internal pH elevation in response to this environmental stress. Understanding the biomineralization mechanisms underlying the vital effects is important for better use of these tracers for paleoceanographic applications, and may shed light on the response of marine calcification to future ocean acidification
Organic Additive-derived Films on Cu Electrodes Promote Electrochemical CO₂ Reduction to C₂₊ Products Under Strongly Acidic Conditions
No full textElectrochemical CO₂ reduction (CO₂R) at low pH is desired for high CO₂ utilization; the competing hydrogen evolution reaction (HER) remains a challenge. High alkali cation concentration at a high operating current density has recently been used to promote electrochemical CO₂R at low pH. Herein we report an alternative approach to selective CO₂R (>70 % Faradaic efficiency for C₂₊ products, FE_(C2+)) at low pH (pH 2; H₃PO₄/KH₂PO₄) and low potassium concentration ([K⁺]=0.1 M) using organic film-modified polycrystalline copper (Modified-Cu). Such an electrode effectively mitigates HER due to attenuated proton transport. Modified-Cu still achieves high FE_(C2+) (45 % with Cu foil /55 % with Cu GDE) under 1.0 M H₃PO₄ (pH≈1) at low [K⁺] (0.1 M), even at low operating current, conditions where HER can otherwise dominate
A Heterozygous Mutation in MFF Associated with a Mild Mitochondrial Phenotype
No full textBackground: The number of mutations in nuclear encoded genes causing mitochondrial disease is ever increasing. Identification of these mutations is particularly important in the diagnosis of neuromuscular disorders as their presentation may mimic other acquired disorders. We present a novel heterozygous variant in mitochondrial fission factor (MFF) which mimics myasthenia gravis.
Objective: To determine if the MFF c.937G>A, p.E313K variant causes a mild mitochondrial phenotype. Methods: We used whole exome sequencing (WES) to identify a novel heterozygous variant in MFF in a patient with ptosis, fatigue and muscle weakness. Using patient derived fibroblasts, we performed assays to evaluate mitochondrial and peroxisome dynamics.
Results: We show that fibroblasts derived from this patient are defective in mitochondrial fission, despite normal recruitment of Drp1 to the mitochondria. Conclusions: The MFF c.937G>A, p.E313K variant leads to a mild mitochondrial phenotype and is associated with defective mitochondrial fission in patient-derived fibroblasts
The Scott conjecture for large Coulomb systems: a review
No full textWe review some older and more recent results concerning the energy and particle distribution in ground states of heavy Coulomb systems. The reviewed results are asymptotic in nature: they describe properties of many-particle systems in the limit of a large number of particles. Particular emphasis is put on models that take relativistic kinematics into account. While non-relativistic models are typically rather well understood, this is generally not the case for relativistic ones and leads to a variety of open questions
Effects of the environment on the multiplicity properties of stars in the STARFORGE simulations
No full textMost observed stars are part of a multiple star system, but the formation of such systems and the role of environment and various physical processes is still poorly understood. We present a suite of radiation-magnetohydrodynamic simulations of star-forming molecular clouds from the STARFORGE project that include stellar feedback with varied initial surface density, magnetic fields, level of turbulence, metallicity, interstellar radiation field, simulation geometry and turbulent driving. In our fiducial cloud, the raw simulation data reproduces the observed multiplicity fractions for Solar-type and higher mass stars, similar to previous works. However, after correcting for observational incompleteness the simulation underpredicts these values. The discrepancy is likely due to the lack of disc fragmentation, as the simulation only resolves multiples that form either through capture or core fragmentation. The raw mass distribution of companions is consistent with randomly drawing from the initial mass function for the companions of > 1 M_⊙ stars. However, accounting for observational incompleteness produces a flatter distribution similar to observations. We show that stellar multiplicity changes as the cloud evolves and anticorrelates with stellar density. This relationship also explains most multiplicity variations between runs, i.e. variations in the initial conditions that increase stellar density (increased surface density, reduced turbulence) also act to decrease multiplicity. While other parameters, such as metallicity, interstellar radiation, and geometry significantly affect the star formation history or the IMF, varying them produces no clear trend in stellar multiplicity properties
A Highly Magnified Gravitationally Lensed Red QSO at z = 2.5 with a Significant Flux Ratio Anomaly
No full textWe present the discovery of a gravitationally lensed dust-reddened QSO at z = 2.517, identified in a survey for QSOs by infrared selection. Hubble Space Telescope imaging reveals a quadruply lensed system in a cusp configuration, with a maximum image separation of ∼1″.8. We find that, compared to the central image of the cusp, the neighboring brightest image is anomalous by a factor of ∼7–10, which is the largest flux anomaly measured to date in a lensed QSO. Incorporating high-resolution Very Large Array radio imaging and submillimeter imaging with the Atacama Large Millimeter/submillimeter Array, we conclude that a low-mass perturber is the most likely explanation for the anomaly. The optical through near-infrared spectrum reveals that the QSO is moderately reddened with E(B − V) ≃ 0.7–0.9. We see an upturn in the ultraviolet spectrum due to ∼1% of the intrinsic emission being leaked back into the line of sight, which suggests that the reddening is intrinsic and not due to the lens. The QSO may have an Eddington ratio as high as L/L_Edd ≈ 0.2. Consistent with previous red QSO samples, this source exhibits outflows in its spectrum, as well as morphological properties suggestive of it being in a merger-driven transitional phase. We find a host galaxy stellar mass of log M⋆/M_⊙ = 11.4, which is higher than the local M_BH versus M⋆ relation but consistent with other high-redshift QSOs. When demagnified, this QSO is at the knee of the luminosity function, allowing for the detailed study of a more typical moderate-luminosity infrared-selected QSO at high redshift
Introduction to the special issue on celebrating the 15th anniversary of JIOHS and the 70th anniversary of HUST
No full textSince launching in 2008, Journal of Innovative Optical Health Sciences (JIOHS) has been published for 15 years until 2022. Supported by the founding advisor Prof. Britton Chance and other founding Editorial Members, JIOHS was quickly embraced by the biomedical optics community, especially in Asia. Authors submitted some of their high quality papers to JIOHS, which led to a constant Impact Factor (IF) increase from the first IF 0.632 to IF 2.396 (Journal Citation Report 2021). JIOHS is now one of the most important journals in the field of biomedical optics and biophotonics. The year 2022 is the 15th Anniversary of JIOHS and also the 70th Anniversary of Huazhong University of Science & Technology (HUST). Naturally, organizing a special issue is certainly the most important way to celebrate these two anniversaries. A brief history of the development of biophotonics and biomedical optics at HUST, associated with the formation of the journal and the development of international relations, including through the regular organization of the international conference PIBM and the Chinese-Russian Workshops, is presented in the photos. This special issue on Celebrating the 15th Anniversary of JIOHS and the 70th Anniversary of HUST consists of eight invited and two regular articles. Among them, nine articles are published in January 2023 issue, while the paper from Wei R Chen will be available in the next issue. All these articles are dedicated to highlighting the latest developments in the fields of biomedical optics and biophotonics
Wastewater surveillance for public health
No full textDating back to the origins of modern epidemiology, wastewater surveillance has predominantly been used to track pathogens spread by fecal-oral transmission such as those that cause cholera and polio. However, more than just these “enteric” pathogens are shed via the gut, as highlighted by the success of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wastewater surveillance (1, 2), recent work on tracking influenza virus (3) and monkeypox virus (4), and observations of extensive pathogen diversity in stool (5, 6). Wastewater is now a core component of infectious disease monitoring, providing a variant-specific, community-representative picture of public health trends that captures previously undetected spread and pathogen transmission links. Building on recent laboratory and analytical advances to identify the diverse pathogens present in sewage will be essential to ongoing efforts to understand disease risks and will transform infectious disease surveillance
Label-free intraoperative histology of bone tissue via deep-learning-assisted ultraviolet photoacoustic microscopy
No full textObtaining frozen sections of bone tissue for intraoperative examination is challenging. To identify the bony edge of resection, orthopaedic oncologists therefore rely on pre-operative X-ray computed tomography or magnetic resonance imaging. However, these techniques do not allow for accurate diagnosis or for intraoperative confirmation of the tumour margins, and in bony sarcomas, they can lead to bone margins up to 10-fold wider (1,000-fold volumetrically) than necessary. Here, we show that real-time three-dimensional contour-scanning of tissue via ultraviolet photoacoustic microscopy in reflection mode can be used to intraoperatively evaluate undecalcified and decalcified thick bone specimens, without the need for tissue sectioning. We validate the technique with gold-standard haematoxylin-and-eosin histology images acquired via a traditional optical microscope, and also show that an unsupervised generative adversarial network can virtually stain the ultraviolet-photoacoustic-microscopy images, allowing pathologists to readily identify cancerous features. Label-free and slide-free histology via ultraviolet photoacoustic microscopy may allow for rapid diagnoses of bone-tissue pathologies and aid the intraoperative determination of tumour margins