Preliminary reports of the Quaternary sediment core drilled in Nakatokushima-cho Tokushima City, West Japan

A 80 m-long borehole core (TK-B-1) drilled in the Tokushima Plain was examined. Based on the sedimentary facies, volcanic ash layers, pollen fossils and radiocarbon dates, this core was divided into the following 13 units. Unit 1 is a metamorphic rock that forms the base of the Tokushima Plain. Units 3 to 8 are Pleistocene and consist of marine and fluvial strata. Units 12-10 are considered to be Alluvium based on radiocarbon dates, and K-Ah tephra found in Unit 11. In Unit 10, we found a volcanic glass concentration derived from AT tephra, but the concentration is a possibility of rework. We intend to reveal the subsurface geological structure of the Tokushima Plain based on the database of borehole data, lithologic stratigraphy, volcanic ash stratigraphy and biostratigraphy

Paleoclimatic and paleoceanographic records through Marine Isotope Stage 19 at the Chiba composite section, central Japan: A key reference for the EarlyeMiddle Pleistocene Subseries boundary

Marine Isotope Stage (MIS) 19 is an important analogue for the present interglacial because of its similar orbital configuration, especially the phasing of the obliquity maximum to precession minimum. However, sedimentary records suitable for capturing both terrestrial and marine environmental changes are limited, and thus the climatic forcing mechanisms for MIS 19 are still largely unknown. The Chiba composite section, east-central Japanese archipelago, is a continuous and expanded marine sedimentary succession well suited to capture terrestrial and marine environmental changes through MIS 19. In this study, a detailed oxygen isotope chronology is established from late MIS 20 to early MIS 18, supported by a U-Pb zircon age and the presence of the Matuyama–Brunhes boundary. New pollen, marine microfossil, and planktonic foraminiferal δ18O and Mg/Ca paleotemperature records reveal the complex interplay of climatic influences. Our pollen data suggest that the duration of full interglacial conditions during MIS 19 extends from 785.0 to 775.1 ka (9.9 kyr), which offers an important natural baseline in predicting the duration of the present interglacial. A Younger Dryas-type cooling event is present during Termination IX, suggesting that such events are linked to this orbital configuration. Millennial- to multi-millennial-scale variations in our δ18O and Mg/Ca records imply that the Subarctic Front fluctuated in the northwestern Pacific Ocean during late MIS 19, probably in response to East Asian winter monsoon variability. The climatic setting at this time appears to be related to less severe summer insolation minima at 65˚N and/or high winter insolation at 50˚N. Our records do not support a recently hypothesized direct coupling between variations in the geomagnetic field intensity and global/regional climate change. Our highly resolved paleoclimatic and paleoceanographic records, coupled with a well-defined Matuyama–Brunhes boundary (772.9 ka; duration 1.9 kyr), establish the Chiba composite section as an exceptional climatic and chronological reference section for the Early–Middle Pleistocene boundary.ArticleQuaternary Science Reviews 191: 406-430(2018)journal articl

GW501516, a PPARδ Agonist, Ameliorates Tubulointerstitial Inflammation in Proteinuric Kidney Disease via Inhibition of TAK1-NFκB Pathway in Mice

Peroxisome proliferator-activated receptors (PPARs) are a nuclear receptor family of ligand-inducible transcription factors, which have three different isoforms: PPARα, δ and γ. It has been demonstrated that PPARα and γ agonists have renoprotective effects in proteinuric kidney diseases; however, the role of PPARδ agonists in kidney diseases remains unclear. Thus, we examined the renoprotective effect of GW501516, a PPARδ agonist, in a protein-overload mouse nephropathy model and identified its molecular mechanism. Mice fed with a control diet or GW501516-containing diet were intraperitoneally injected with free fatty acid (FFA)-bound albumin or PBS(−). In the control group, protein overload caused tubular damages, macrophage infiltration and increased mRNA expression of MCP-1 and TNFα. These effects were prevented by GW501516 treatment. In proteinuric kidney diseases, excess exposure of proximal tubular cells to albumin, FFA bound to albumin or cytokines such as TNFα is detrimental. In vitro studies using cultured proximal tubular cells showed that GW501516 attenuated both TNFα- and FFA (palmitate)-induced, but not albumin-induced, MCP-1 expression via direct inhibition of the TGF-β activated kinase 1 (TAK1)-NFκB pathway, a common downstream signaling pathway to TNFα receptor and toll-like receptor-4. In conclusion, we demonstrate that GW501516 has an anti-inflammatory effect in renal tubular cells and may serve as a therapeutic candidate to attenuate tubulointerstitial lesions in proteinuric kidney diseases

Pliocene integrated chronostratigraphy from the Anno Formation, Awa Group, Boso Peninsula, central Japan, and its paleoceanographic implications

Abstract The Pliocene climate is one of the best analogs for the climate of a globally warmer future. Here, we present a new Pliocene integrated chronostratigraphy from the Anno Formation in the uppermost Awa Group, which is distributed throughout the Boso Peninsula, central Japan, based on paleomagnetic and benthic foraminiferal oxygen isotope records. This new chronostratigraphy provides valuable constraints for paleoceanographic and paleoclimatic studies in the northwestern Pacific Ocean, where the number of paleoceanographic records is limited due to the lack of calcareous microfossils from deep-sea sediment cores, with the exception of some plateaus at water depths above the calcite compensation depth (CCD). Paleomagnetic results indicate that the Anno Formation corresponds to the period extending from the Nunivak normal polarity subchronozone (4.493–4.631 Ma) to Chron C2An.2n (3.116–3.207 Ma), which is just above the Mammoth reversed polarity subchronozone. Although foraminifera are not found in the middle Anno Formation, our oxygen isotope records from the upper and lower Anno Formation demonstrate the recording of glacial–interglacial cycles. However, the amplitude of our δ18O profile is much larger than that of the LR04 stack, with similar to slightly lower glacial values and much lower interglacial values. This observation implies that the bottom water had lower δ18O values and/or a warmer water mass during interglacials compared with global average deep-water regions

Paleomagnetic direction and paleointensity variations during the Matuyama-Brunhes polarity transition from a marine succession in the Chiba composite section of the Boso Peninsula, central Japan

The youngest geomagnetic polarity reversal, the Matuyama-Brunhes (M-B) boundary, provides an important plane of data for sediments, ice cores, and lavas. The geomagnetic field intensity and directional changes that occurred during the reversal also provide important information for understanding the dynamics of the Earth's outer core, which generates the magnetic field. However, the reversal process is relatively rapid in terms of the geological timescale; therefore, adequate temporal resolution of the geomagnetic field record is essential for addressing these topics. Here, we report a new high-resolution paleomagnetic record from a continuous marine succession in the Chiba composite section of the Kokumoto Formation of the Kazusa Group, Japan, that reveals detailed behaviors of the virtual geomagnetic poles (VGPs) and relative paleointensity changes during the M-B polarity transition. The resultant relative paleointensity and VGP records show a significant paleointensity minimum near the M-B boundary, which is accompanied by a clear "polarity switch." A newly obtained high-resolution oxygen isotope chronology for the Chiba composite section indicates that the M-B boundary is located in the middle of marine isotope stage (MIS) 19 and yields an age of 771.7 ka for the boundary. This age is consistent with those based on the latest astronomically tuned marine and ice core records and with the recalculated age of 770.9 +/- 7.3 ka deduced from the U-Pb zircon age of the Byk-E tephra. To the best of our knowledge, our new paleomagnetic data represent one of the most detailed records on this geomagnetic field reversal that has thus far been obtained from marine sediments and will therefore be key for understanding the dynamics of the geomagnetic dynamo and for calibrating the geological timescale

MOESM1 of Paleomagnetic direction and paleointensity variations during the Matuyama–Brunhes polarity transition from a marine succession in the Chiba composite section of the Boso Peninsula, central Japan

Additional file 1 Rock-magnetic and paleomagnetic results from the Yoro-River and Yoro-Tabuchi sections, which were used for Figure 6

High-resolution 10Be and paleomagnetic recording of the last polarity reversal in the Chiba composite section: Age and dynamics of the Matuyama–Brunhes transition

International audienceWe present new magnetic (direction and relative paleointensity) and beryllium isotope (10 Be, 9 Be and 10 Be/ 9 Be ratio) results covering the last geomagnetic reversal, i.e., the Matuyama-Brunhes transition (MBT), from the Chiba composite section (CbCS), east-central Japan. The very high sedimentation rates (>90 cm/ka) of the studied site, a candidate site for the global boundary stratotype section and point (GSSP) of the Lower-Middle Pleistocene boundary, allow the acquisition of a dataset of exceptional resolution. Coupled cosmogenic 10 Be and magnetic results measured on the same samples demonstrate that the magnetization acquisition conserved the timing of rapid geomagnetic features, allowing accurate paleomagnetic interpretations. A polarity switch (PS) capturing most of the angular deviation occurring between 771.9 and 773.9 ka was followed by a directional instability rebound (IC1) until 768.5 ka. This sequence with 5.4 ka duration was characterized by a weak dipole field as low as 2.3 ± 0.3 × 10 22 Am 2. Four rapid episodes of directional instabilities preceding and following the PS-IC1 phase completed the reversal sequence. The asymmetry observed between the long-term dipole decay and sharp recovery, and rapid oscillations (<1 ka) demonstrate the complex transitional field behavior during dipole moment low before reestablishment of the full polarity state. Our observations reinforce the fact that most reversal records do not integrate the full field behavior associated with the geodynamo action. Although this poses problems for understanding the underlying physical processes that produce reversals, it does not hamper stratigraphic correlations among most geologic records

Effects of a single use of the GnRH analog buserelin on the induction of ovulation and endocrine profiles in heavy draft mares

We observed structural changes in the follicles and uterus of heavy draft mares during estrus and examined the effect of a single injection of the gonadotropin-releasing hormone analog buserelin on ovulation and endocrine profiles. Twenty-two heavy draft mares were divided into a buserelin-treated group (n=8) and a control group (n=14). Mares were given an intramuscular injection of 40 µg buserelin when they presented signs of estrus to a teaser stallion, had ≥45 mm diameter follicles, and presented decreased uterine edema compared with the previous examination. The follicles and uterus were monitored using transrectal ultrasound imaging and measurement of blood levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone, and estradiol-17β. The ovulation rates within 48 hr was significantly higher in the treated group (100%, 8/8) than in the control group (57.1%, 8/14; P=0.051). The mean ± SEM time before confirmation of ovulation was 29 ± 9 hr for the treated group and 59 ± 7 hr for the control group. There were no significant differences in mating frequency, double ovulation rate, or fertility rate between the two groups. One to two days after administering buserelin, LH and FSH temporarily increased, and in the control group, LH was high during ovulation, whereas FSH temporarily increased with the growth of the follicle. These results indicate that a single injection of 40 µg buserelin when follicles are at least 45 mm in diameter and uterine edema is decreased is effective for inducing ovulation.https://www.jstage.jst.go.jp/article/jes/27/4/27_1615/_article/-char/ja