Light and Electron Microscopic Observation in a Case of Congenital Renal Proximal Tubular Dysfunction

We report a case of congenital renal proximal tubular dysfunction (CRPTD) accompanied by IgA nephropathy. The mesangial matrix was slightly increased with depositions of IgA and C3. Podocytes contained many clear vacuoles. Cuboidal cells, as well as squamous cells, lined the parietal epithelium of Bowman's capsule, although the functional or pathological significance of the cuboidal cells is unknown. The proximal tubular cells appeared to have a less-developed apical endocytic complex, basal infoldings and fewer lysosomes. These morphological changes may reflect proximal tubular dysfunction

An Examination of the Sea Ice Rheology for Seasonal Ice Zones Based on Ice Drift and Thickness Observations

The validity of the sea ice rheological model formulated by Hibler (1979), which is widely used in present numerical sea ice models, is examined for the Sea of Okhotsk as an example of the seasonal ice zone (SIZ), based on satellite-derived sea ice velocity, concentration and thickness. Our focus was the formulation of the yield curve, the shape of which can be estimated from ice drift pattern based on the energy equation of deformation, while the strength of the ice cover that determines its magnitude was evaluated using ice concentration and thickness data. Ice drift was obtained with a grid spacing of 37.5 km from the AMSR-E 89 GHz brightness temperature using a maximum cross-correlation method. The ice thickness was obtained with a spatial resolution of 100 m from a regression of the PALSAR backscatter coefficients with ice thickness. To assess scale dependence, the ice drift data derived from a coastal radar covering a 70 km range in the southernmost Sea of Okhotsk were similarly analyzed. The results obtained were mostly consistent with Hibler's formulation that was based on the Arctic Ocean on both scales with no dependence on a time scale, and justify the treatment of sea ice as a plastic material, with an elliptical shaped yield curve to some extent. However, it also highlights the difficulty in parameterizing sub-grid scale ridging in the model because grid scale ice velocities reduce the deformation magnitude by half due to the large variation of the deformation field in the SIZ. Plain Language Summary Sea ice plays an important role in shaping the polar climate. Therefore, it is quite important to accurately simulate its behavior in climate models. This study focuses on the treatment of the dynamical processes of sea ice in numerical models, especially the rheology relating ice stress to deformation. In these models, sea ice rheology is closely related to ice thickness. In many present models, the viscous-plastic rheology formulated by Hibler has been used, irrespective of region modeled and grid scales. In this study, the validity of this formulation was examined for the Sea of Okhotsk ice, a typical seasonal ice zone (SIZ), based on AMSR-derived ice drift and PALSAR-derived ice thickness, in comparison with the Beaufort Sea in the Arctic. The nearby coastal radar data were also used to assess scale dependence. Our observational results support the Hibler's formulation to some extent, suggesting its validity and applicability to the SIZ. However, it was also noted that the variation of the deformation field in the Sea of Okhotsk is so large that the deformation magnitude obtained on a grid scale is reduced by half, indicating the difficulty in parameterizing subgrid scale ridging in the model

Measuring Deformed Sea Ice in Seasonal Ice Zones Using L-Band SAR Images

In order to improve the understanding of the dynamical deformation processes of sea ice in the seasonal ice zone (SIZ), measures to detect deformed ice were developed and validated using satellite L-band synthetic aperture radar (ScanSAR) images for the southern Sea of Okhotsk. To approach, sea ice was categorized into three ice types, typical of the sea ice in this region: nilas (thin level), pancake ice (thin rough), and deformed ice (thick rough), and then the measures to classify into these categories were developed using ALOS/Phased Array type L-band Synthetic Aperture Radar (PALSAR) as a function of backscatter coefficients at HH polarization (sigma(0)(HH)) and incidence angle (theta(i)), based on the field observations. Comparative analysis confirmed that PALSAR can detect deformed ice more efficiently than RADARSAT-2 (C-band SAR). The temporal evolution of the area, judged as deformed ice from these measures, shows significant variability with both time and space, and deformed ice regions appear in relatively linear alignments with a width of a few tens of kilometers in the inner ice pack region, consistent with ice drift convergence. To confirm the results, PALSAR-2 images at HH and HV polarizations were examined as a function of theta(i), based on the four-year field observations in the same area. The results revealed that sigma(0)(HH) and sigma(0)(HV) are both subject to floe sizes as well as deformed ice, and sigma(0)(HV) is more sensitive. This indicates that care should be taken when applying these measures to the ice areas where significantly small floes are dominant like the marginal ice zone

Administration of 8-Methoxypsoralen and Ultraviolet A Irradiation (PUVA) Induces Turnover of Mast Cells in the Skin of C57BL/6 Mice

Administration of 8-methoxypsoralen followed by ultraviolet A irradiation (PUVA treatment) has been used as a therapy for urticaria pigmentosa. The effect of PUVA treatment on cutaneous mast cells in mice was investigated by using giant granules of mast cells from C57BL/6-bgJ/bgJ (Chediak-Higashi syndrome) mice as a marker. C57BL/6-+/+ mice were lethally irradiated and rescued by bone marrow transplantation from C57BL/6-bgJ/bgJ mice. In the radiation chimeras, mast cells in the skin were of +/+ type and mast-cell precursors migrating in the bloodstream were bgJ/bgJ. When PUVA treatment was applied to the skin of the radiation chimeras, the total number of mast cells continued to decrease until the third week after the treatment and then recovered to pre-treatment levels. The initial reduction was attributed to the decrease of +/+-type mast cells, and the subsequent recovery to be as a result of the increase of bgJ/bgJ-type mast cells. This observation may explain the fact that the therapeutic effect of PUVA treatment is transient. Symptoms of urticaria pigmentosa become manifest after the cessation of PUVA treatment probably because new mast cells differentiate from bone marrow – derived precursors

Mechanism of ice-band pattern formation caused by resonant interaction between sea ice and internal waves in a continuously stratified ocean

In polar oceans, ice-band patterns are frequently observed around the ice edge in the winter, where sea ice production and melting continually occur. A better understanding of such fundamental processes in marginal ice zones (MIZs) may be key to accurate predictions of sea-ice evolution. Ice bands exhibit approximately 10-km-scale regular band spacings, and their long axes turn to the counter-clockwise (clockwise) with respect to the wind direction in the Northern (Southern) Hemisphere. We formulate a theory that is relevant for a continuously stratified ocean and compare the theoretical results with the numerical-model results and satellite observations. The numerical results quantitatively agree well with the theory. In particular, resonance condition, on which the phase speed of internal wave matches with the ice-band propagation speed, is always satisfied even if wind speed becomes slow. This is because there are an infinite number of baroclinic modes in continuously stratified ocean. We also show that an ice-band pattern emerges from a random initial ice concentration even though the wind is homogeneous. Plume-like ice bands along ice edge, which are frequently observed by satellites, are well explained by the pattern formation from random noise. Various effects of the ice-band formation were explored with respect to the relationship between the initial ice concentration and the wind direction, ice roughness, ice thickness, temporal variation of wind, and the Coriolis parameter

The Interannual Variability of Sea Ice Area, Thickness, and Volume in the Southern Sea of Okhotsk and Its Likely Factors

The lowest latitude sea ice in the world (excluding coastal freezing) is in the southern Sea of Okhotsk (south of 46 degrees N), where it has significant impacts on freshwater input and primary production. This region is subject to climate change, and accordingly the monitoring of sea ice conditions is important. However, the interannual variability of the region's sea ice is poorly understood due to its logistical challenges. Sea ice observations have been conducted in this region every winter for the period 1996-2020. The interannual variability of the ice conditions and the likely factors responsible for it were investigated using visual observations following the international ASPeCt protocol, combined with satellite SSM/I-SSMIS ice concentration data (1988-2020). AMSR-derived ice drift data sets and ERA5 meteorological reanalysis data sets were also analyzed to examine the effects of dynamic and thermodynamic processes. Our analysis revealed that (a) sea ice area in this region varies differently from that in the central and northern Sea of Okhotsk, where decreasing trends are reported, (b) sea ice volume has remarkable interannual variation and the peaks appeared much to more affected by dynamically deformed ice than freezing conditions, and (c) prominently deformed ice can be explained by taking shear components into account based on sea ice rheology. These results suggest the importance of including the proper sea ice rheology in numerical sea ice models to reproduce the realistic sea ice volume and deformation processes, for all seasonal ice zones. Plain Language Summary The southern Sea of Okhotsk (south of 46 degrees N) is the southernmost area of the northern hemisphere, excluding coastal freezing, where there is wintertime sea ice cover. Although this sea ice has significant impacts on the surface heat and freshwater balance and biogeochemical cycles across a wide region, its interannual variability is not well understood yet. Long-term field observations from the patrol vessel in this region for 1996-2020, in combination with satellite data, reveals that the variability of sea ice area south of 46 degrees N is uncorrelated with that in the northern and central regions, and that the sea ice thickness and volume is mainly controlled by dynamical pile-up processes, rather than the thermodynamical freezing conditions. Analysis of satellite-derived ice drift datasets shows that the rheology traditionally used in many sea ice models, in which sea ice behaves like a plastic under the ordinary stress, holds consistently explaining the yearly variations of deformed ice contribution. Considering that sea ice rheology is essential to the dynamical part of sea ice models, our result promotes the possibility of accurately predicting sea ice thickness and volume in the seasonal ice zone