We make a microscopic theory of the photoswitchable magnetism in copper octacyanomolybdates. By numerically solving a time-dependent Schrödinger equation based on the relevant extended Hubbard model, ...we reproduce magnetization by green-light irradiation and subsequent demagnetization by orange-light irradiation. At the onset of the ferromagnetism, the charge-transfer gap disappears. In an attempt to stimulate experimental investigations, we simulate time evolution of the angle-resolved photoemission spectroscopy and optical-conductivity spectra.
Anthropogenic CO2 emissions are contributing to global warming and ocean acidification. Rapid and accurate measurements of seawater carbonate chemistry are critical to understand current changes in ...the ocean and to predict future effects of such changes on marine organisms and ecosystems. Total alkalinity (AT) measurements can be used to directly determine the calcification rate, but they are time-consuming and require large sample volumes. Herein, we describe an automated and transportable flow-through system that can conduct continuous AT measurement using an ion sensitive field effect transistor (ISFET) – Ag/AgCl sensor and three different reference materials. The response time, stability, and uncertainty of our system were evaluated by comparing AT values of calibrated reference materials to those calculated by our system. Our system requires only small amounts of seawater (<10 mL) and a short time per sample (<5 min) to produce results with a relative uncertainty of less than 0.1% (approx. 2.2 μmol kg−1). This system is expected to facilitate easy and rapid in-situ measurement of AT. Continuous AT measurements would enable us to determine short-term calcification responses to changes in light or temperature and improve our understanding of the metabolic mechanisms of creatures such as corals.
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•A novel transportable analysis system for continuous total alkalinity was developed.•It requires small sample volume (<10 mL) and a short time (<5 min).•The relative uncertainty of our system is less than 0.1%.•Our system is expected to facilitate in-situ total alkalinity measurement.
Non-contact HR measurement is becoming an active research area. Recently, remote photoplethysmography (rPPG) measurement based on simple skin optics model has been proposed and shown to be effective. ...In this paper, we propose an accurate remote observation of the heart rate (HR) and heart rate variability (HRV) based on hemoglobin component estimation which is based on a detailed skin optics model. We perform experiments to measure subjects at rest and under cognitive stress with the proposed method putting a polarized filter in front of the camera to evaluate the principle of the framework. From the results of the experiments, the proposed method shows a high correlation with the electrocardiograph (ECG) which is assumed as the ground truth. We also evaluate the proposed method without putting any polarized filter and confirm the usefulness for the remote observation of HRV which requires accurate detection of HR.
Carbon captured by marine living organisms is called “blue carbon”, and
seagrass meadows are a dominant blue carbon sink. However, our knowledge of
how seagrass increases sedimentary organic carbon ...(OC) stocks is limited. We
investigated two pathways of OC accumulation: trapping of organic matter in
the water column and the direct supply of belowground seagrass detritus. We
developed a new type of box corer to facilitate the retrieval of intact cores
that preserve the structures of both sediments (including coarse sediments
and dead plant structures) and live seagrasses. We measured seagrass density,
total OC mass (OCtotal) (live seagrass OC biomass
(OCbio) + sedimentary OC mass (OCsed)), and the
stable carbon isotope ratio (δ13C) of OCsed and its
potential OC sources at Thalassia hemprichii dominated back-reef and
Enhalus acoroides dominated estuarine sites in the tropical
Indo-Pacific region. At points with vegetation, OCbio accounted
for 25 % and OCsed for 75 % of OCtotal; this
contribution of OCbio to OCtotal is higher than in
globally compiled data. Belowground detritus accounted for ∼ 90 %
of the OC mass of dead plant structures (> 2 mm in size)
(OCdead). At the back-reef site, belowground seagrass biomass,
OCdead, and δ13C of OCsed (δ13Csed) were positively correlated with OCsed,
indicating that the direct supply of belowground seagrass detritus is a major
mechanism of OCsed accumulation. At the estuarine site,
aboveground seagrass biomass was positively correlated with OCsed
but δ13Csed did not correlate with OCsed,
indicating that trapping of suspended OC by seagrass leaves is a major
mechanism of OCsed accumulation there. We inferred that the
relative importance of these two pathways may depend on the supply
(productivity) of belowground biomass. Our results indicate that belowground
biomass productivity of seagrass meadows, in addition to their aboveground
morphological complexity, is an important factor controlling their OC stock.
Consideration of this factor will improve global blue carbon estimates.
Ocean acidification decreases the pH of seawater and the seawater saturation state with respect to CaCO₃ minerals. In the event of ocean acidification, Mg-calcite is considered to be the first ...mineral to dissolve. Dissolution of Mg-calcite is more prevalent at depth in the sediment than at the sediment interface because of production of CO₂ resulting from microbial decomposition of organic matter. Rates of CaCO₃ dissolution can be estimated from total alkalinity (AT) fluxes calculated from concentration gradients and diffusion coefficients. We estimated AT flux in a sandy area of the Shiraho coral reef under natural hydrodynamic conditions using eddy covariance and sedimentary AT profiles. The calculated nighttime AT flux at the sediment–water interface was 0.4–2.6 mmol m−2 h−1. Analysis of the sedimentary profile at a depth of 0–20 mm indicated that respiration by organisms consumed oxygen and produced CO₂ during night and that photosynthesis enhanced O₂ concentrations during the day. However, dissolved oxygen was depleted at all times in sediments deeper than 20 mm. The pore-water aragonite saturation state (=Ωₐ) was constant at ∼ 3.0, which is equivalent to a value of 1.0 for the saturation state with respect to foraminifera (=Ωfora), as determined in a previous study. Both organic reactions (e.g., respiration) and inorganic Mg-calcite dissolution occur in the sediment, leading to a constant Ωfora value in the sediment. These data confirm the metastable equilibrium of pore water with respect to Mg-calcite from foraminifera, which is the most soluble phase in the sediment.
In this paper, we proposed a method for matching the color and glossiness of an object between different displays by using tone mapping. Since displays have their own characteristics, such as maximum ...luminance and gamma characteristics, the color and glossiness of an object when displayed differs from one display to another. The color can be corrected by conventional color matching methods, but the glossiness, which greatly changes the impression of an object, needs to be corrected. Our practical challenge was to use tone mapping to correct the high-luminance part, also referred to as the glossy part, which cannot be fully corrected by color matching. Therefore, we performed color matching and tone mapping using high dynamic range images, which can record a wider range of luminance information as input. In addition, we varied the parameters of the tone-mapping function and the threshold at which the function was applied to study the effect on the object's appearance. We conducted a subjective evaluation experiment using the series category method on glossy-corrected images generated by applying various functions to each display. As a result, we found that the differences in glossiness between displays could be corrected by selecting the optimal function for each display.
Employing a two-orbital extended Peierls–Hubbard model, we demonstrate the photomanipulation of mixed-valent states in platinum-halide ladder compounds. There are two types of interchain valence ...arrangements, namely in-phase and out-of-phase types. The conversion of the in-phase structure to the out-of-phase structure is induced by photoirradiation, which is accelerated with increasing light intensity, while the reverse process hardly occurs. The out-of-phase arrangement is highly stabilized in the photoexcited states by the interchain electron transfer.
Cyclic polylactide (
PLA) is a structural isomer of linear polylactide (PLA) although it possesses unique functionalities in comparison to its linear counterpart. Hitherto, the control of ...stereochemical purity in conventional
PLA synthesis has not been achieved. In this study, highly stereochemically pure
PLA was synthesized in the absence of a metal catalyst and organic solvent, which required high consumption of the residual monomer. The synthesis was conducted in supercritical carbon dioxide under CO₂ plasticizing polymerization conditions in the presence of an organocatalyst and thiourea additives. In comparison with the stereocomplexes synthesized through conventional methods,
PLA from l-lactide (
PLLA) and
PLA from d-lactide (
PDLA) were synthesized with higher stereochemical purity and improved thermal stability. Moreover, the method presented herein is environmentally friendly and thus, applicable on an industrial level.
In recent years, the problem of declining birthrate has occurred, and how to increase the working-age population has been discussed as a problem to be tackled immediately. The rise in the unmarried ...rate also contributes to a decline in the birth rate. To solve these problems, you need a way to choose a partner appropriately. In this study, we investigated the relationship between heart rate variability (HRV) and sexual attractiveness while heterosexual men observed the photos and self-introduction movies of women. We measured the indicators of HRV, including low-frequency (LF) and high-frequency (HF) HRV, by computing
R
–
R
intervals of the heartbeat waveform. We also demonstrated the time-varying transition of HRV parameters during the self-introduction movies. We found that higher attractiveness evaluation scores were proportional to the transition of LF/HF. The LF/HF value increased when subjects watched videos of females who had been judged as having high attractiveness.
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