Changes in ocean conditions in response to climate variability and density-dependent factors are increasingly recognized as primary determinants of spatiotemporal dynamics of spawning in small ...pelagic fishes. However, the effects of climatic and density-dependent factors are complexly intertwined, and their respective effects remain controversial. We estimated climatic and density-dependent effects simultaneously using long-term egg survey data for Japanese sardine Sardinops melanostictus in the Tsushima Warm Current system. We found that in years with warmer sea surface temperature (SST) (climatic factor), egg abundance decreased in southern regions and increased in northern regions, and egg distribution expanded northward along the coast in the northernmost region. In years with colder SST, egg abundance decreased in northern regions, and egg distribution expanded offshore in the southernmost region. In contrast, spawning-stock biomass (SSB) (density-dependent factor) had little effect on the locations of main spawning grounds, whereas changes in SSB caused expansion or contraction of spawning grounds. The temporal peak of spawning shifted earlier in years with warmer SST and was delayed in years with colder SST, although the degree of the changes varied among regions. In contrast, spawning timing did not shift when SSB changed. These results indicate that climatic factors cause shifts and expansion or contraction of spawning grounds and also shifts in spawning timing, whereas density-dependent factors are related to expansion or contraction of spawning grounds but scarcely affect spawning timing. Our study shows that climatic and density-dependent factors differentially affect the spatiotemporal spawning patterns, with some overlap in their effects.
Dynamics of charged sub-micron or colloidal particles in a microfluidic device through cross-stream migration under combined pressure gradients and electric potential gradients was demonstrated using ...confocal microscopy. The microfluidic device was a rectangular cross-section poly(dimethylsiloxane) or PDMS microchannel sealed with a borosilicate glass lid to form a hybrid PDMS-glass device. We postulate that the reported particle migration may arise in response to electrophoretic particle slip, i.e., the difference between the particle and fluid velocities, due to the applied electric potential gradient across the microchannel. Colloidal particle migration was observed either towards or away from the microchannel walls depending on the relative directions for the applied potential and pressure gradients. When pressure gradient driving the fluid flow and potential gradient were applied in the same direction, colloidal particles migrate away from the microchannel walls. In the case of opposite directions for the pressure and potential gradients, colloidal particles migrate towards the microchannel walls and subsequently assemble into distinct bands next to both the bottom glass and top PDMS walls. The results reported here demonstrate that the particle dynamics due to electrophoresis in Poiseuille flow within a microchannel result in non-uniform spatial distributions of colloidal particles via cross-stream migration, with the ability to assemble particles into distinct band structures at channel walls. Such manipulation, once fully realized, could lead to several microfluidics applications in material synthesis, particle separation, and biosensing.
Achievements of NEDO durability projects on SOFC mode are summarized with a focus on the physicochemical mechanisms characterized by diffusion properties of cell components and chemical reactions of ...cell components with gaseous impurities. Ni sintering and depletion including impurity (P, B, S) effects have been examined in terms of the surface/interface energies of Ni/oxide cermet anodes. The conductivity degradation due to the transformation of the cubic YSZ electrolyte was found to be characterized in terms of two time constants for the reductive and the oxidative regions to be determined by the Y‐diffusivity and its enhancement on NiO internal reduction in YSZ, while observed gaps in conductivity degradation behavior between stacks and button cells were ascribed to differences in those physicochemical properties involved, namely cation diffusion and kinetics associated with NiO internal reduction. The cathode performance degradation due to sulfur poisoning exhibits a variety of dependences on the microstructure (dense or porous) of doped‐ceria interlayers, the thickness of YSZ electrolyte and the humidity in the anode atmosphere, suggesting effects of protons in the cathode vicinity and the SrO activity changes during fabrication the LSCF/GDC/YSZ multilayers. Some defect chemical considerations were made on how such defects are affected by fabrication processes.
Volatile compositions of asteroids provide information on the Solar System history and the origins of Earth's volatiles. Visible to near‐infrared observations at wavelengths of <2.5 µm have suggested ...a genetic link between outer main belt asteroids located at 2.5–4 au and carbonaceous chondrite meteorites (CCs) that show isotopic similarities to volatile elements on Earth. However, recent longer wavelength data for large outer main belt asteroids show 3.1 μm absorption features of ammoniated phyllosilicates that are absent in CCs and cannot easily form from materials stable at those present distances. Here, by combining data collected by the AKARI space telescope and hydrological, geochemical, and spectral models of water‐rock reactions, we show that the surface materials of asteroids having 3.1 μm absorption features and CCs can originate from different regions of a single, water‐rock‐differentiated parent body. Ammoniated phyllosilicates form within the water‐rich mantles of the differentiated bodies containing NH3 and CO2 under high water‐rock ratios (>4) and low temperatures (<70°C). CCs can originate from the rock‐dominated cores, that are likely to be preferentially sampled as meteorites by disruption and transport processes. Our results suggest that multiple large main belt asteroids formed beyond the NH3 and CO2 snow lines (currently >10 au) and could be transported to their current locations. Earth's high hydrogen to carbon ratio may be explained by accretion of these water‐rich progenitors.
Plain Language Summary
Small bodies record the Solar System history and how planets formed. Outer main belt asteroids are thought to be composed of bodies similar to carbonaceous chondrites (CCs)—meteorites which possibly sourced Earth's highly volatile elements. However, recent spectral observations suggest the presence of ammonia‐bearing clays on several large asteroids. Ammonia‐bearing clays are absent in CCs, and cannot easily form from materials stable in the current asteroid belt. To understand the conditions necessary to form minerals in those asteroids and CCs, we performed hydrological and geochemical modeling of water‐rock reactions in these bodies. Synthetic spectra were computed for the model mineral assemblages and compared with asteroid observations using a space telescope. We found that surface minerals of outer main belt asteroids, including ammonia‐bearing clays, form from starting materials containing NH3 and CO2 under water rich and low temperature conditions, while CC minerals form under water‐poor conditions. We propose that multiple large outer main belt asteroids formed at distant orbits and differentiated to form different minerals in water‐rich mantles and rock‐dominated cores. Asteroid observations are looking at the product of water‐rich mantles, whereas CCs preferentially sample the rocky cores. This scenario may also explain the elemental composition of Earth's volatiles.
Key Points
Water‐rock reactions and their products in asteroids are simulated by hydrological, geochemical, and spectral models
C‐type asteroids with ammoniated phyllosilicates possibly formed beyond the NH3 and CO2 snow lines and differentiated
Carbonaceous chondrites can originate from rock‐dominated inner cores of the differentiated bodies
Adiponectin is an adipocyte-derived hormone. Recent genome-wide scans have mapped a susceptibility locus for type 2 diabetes and metabolic syndrome to chromosome 3q27, where the gene encoding ...adiponectin is located. Here we show that decreased expression of adiponectin correlates with insulin resistance in mouse models of altered insulin sensitivity. Adiponectin decreases insulin resistance by decreasing triglyceride content in muscle and liver in obese mice. This effect results from increased expression of molecules involved in both fatty-acid combustion and energy dissipation in muscle. Moreover, insulin resistance in lipoatrophic mice was completely reversed by the combination of physiological doses of adiponectin and leptin, but only partially by either adiponectin or leptin alone. We conclude that decreased adiponectin is implicated in the development of insulin resistance in mouse models of both obesity and lipoatrophy. These data also indicate that the replenishment of adiponectin might provide a novel treatment modality for insulin resistance and type 2 diabetes.
Several advanced He-cooled W-alloy divertor concepts have been considered recently for power plant applications. They range in scale from a plate configuration with characteristic dimension of the ...order of 1
m, to the ARIES-CS T-tube configuration with characteristic dimension of the order of 10
cm, to the EU FZK finger concept with characteristic dimension of the order of 1.5
cm. The trend in moving to smaller-scale units is aimed at minimizing the thermal stress under a given heat load; however, this is done at the expense of increasing the number of units, with a corresponding impact on the reliability of the system. The possibility of optimizing the design by combining different configurations in an integrated design, based on the anticipated divertor heat flux profile, also has been proposed. Several heat transfer enhancement schemes have been considered in these designs, including slot jet, multi-hole jet, porous media and pin arrays. This paper summarizes recent US efforts in this area, including optimization and assessment of the different concepts under power plant conditions. Analytical and experimental studies of the concepts and cooling schemes are presented. Key issues are identified and discussed to help guide future R&D, including fabrication, joining, material behavior under the fusion environment and impact of design choice on reliability.
Experimental studies were carried out on fully developed and steady electro-osmotic flow in a rectangular channel where the channel height $h$ is comparable to its width and the thickness of the ...electric double layer characterized by the Debye length is much less than $h$. The nano-particle image velocimetry technique was used to measure the two components of the velocity field parallel to and within about 100 nm of the channel wall for $h\,{\leq}\,25\,\umu$m. The mobility of the particle tracers was calculated from averaged velocity data for various electric field strengths. The experimentally determined mobility values are compared with analytical predictions for dilute aqueous solutions of sodium tetraborate.
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