Late Pleistocene Flora from the Pacific Coast of Fukushima Prefecture, Japan

Based upon the abundant fossil plants collected from the Tsukabara Formation of the third of the five terraces recognized along the Pacific coastal area of Fukushima Prefecture in Northeast Honshu, Japan, analysis was made of the vegetation assemblages, interpretation of the paleoecology, determination of the geological age, and the relationship of the Tsukabara Formation to Pleistocene eustatic movements. From the results of investigation of the cited items it was judged that the fossil flora from the Tsukabara Formation represents the vegetation that fluorished during the last high sea-level and moderate climate of the Late Pleistocene age along the Pacific coast of Fukushima Prefecture. Remarks and or descriptions are given to certain of the plant species

The Effect of Cutting Fluids on Reaming Operation

In order to investigate the effect of cutting fluids on reaming operation, reaming tests were performed with various kinds of cutting fluids, and reaming torque and accuracy of reamed holes were compared for dry and wet cuttings. Tests were also made dry and wet for different cutting conditions, and effects of conditions on reaming torque and accuracy of reamed holes were investigated. Application of cutting fluids improved the accuracy of reamed holes, though reaming torque was increased. The cutting torque component was scarcely affected by cutting fluids. But cutting fluids increased the burnishing torque component in the order of dry, cutting oils, and soluble oils. Dry reaming and reaming with cutting oils produced oversized holes. Reaming with soluble oils produced smaller holes than the actual size of the reamer. The smaller the amount of enlargement of the reamed hole, the larger the burnishing torque component, and the better the surface finish in the order of dry, cutting oils, and soluble oils. With increases in cutting speed, feed, and depth of cut, the amount of enlargement increased and the surface finish of the reamed hole became worse for both dry and wet conditions. The sharp reamer showed a peculiar phenomenon for torque pattern in relation to feed rate. The stable reamer which was used several dozen times produced better reamed holes than the sharp reamer

ひろがるDOHaDの世界

シンポジウム(1-1

Association between Total Antioxidant Capacity in Breast Milk and Postnatal Age in Days in Premature Infants

This study aimed to consider the significance of breast milk in preventing oxidative stress by comparing total antioxidant capacity (TAC) in breast milk and formula milk for premature infants, demonstrating the relationship between TAC in breast milk and postnatal age in days. We used the biological anti-oxidant potential test, a new method to measure TAC in breast milk. Breast milk for premature infants were stored at −20°C and thawed within 48 h of collection. We measured TAC in two types of formula milk in the same way. TAC was clearly higher in breast milk than formula milk. Although a negative correlation was observed between TAC in breast milk and age when collected, TAC was always higher than the average TAC in formula milk. TAC in breast milk is higher than TAC in formula milk. We suggest the importance of breast milk for preventing oxidative stress and starting breastfeeding early

Image-based quantitative determination of DNA damage signal reveals a threshold for G2 checkpoint activation in response to ionizing radiation

Background: Proteins involved in the DNA damage response accumulate as microscopically-visible nuclear foci on the chromatin flanking DNA double-strand breaks (DSBs). As growth of ionizing radiation (IR)-induced foci amplifies the ATM-dependent DNA damage signal, the formation of discrete foci plays a crucial role in cell cycle checkpoint activation, especially in cells exposed to lower doses of IR. However, there is no quantitative parameter for the foci which considers both the number and their size. Therefore, we have developed a novel parameter for DNA damage signal based on the image analysis of the foci and quantified the amount of the signal sufficient for G2 arrest.Results: The parameter that we have developed here was designated as SOID. SOID is an abbreviation of Sum Of Integrated Density, which represents the sum of fluorescence of each focus within one nucleus. The SOID was calculated for individual nucleus as the sum of (area (total pixel numbers) of each focus) x (mean fluorescence intensity per pixel of each focus). Therefore, the SOID accounts for the number, size, and fluorescence density of IR-induced foci, and the parameter reflects the flux of DNA damage signal much more accurately than foci number. Using very low doses of X-rays, we performed a "two-way" comparison of SOID of Ser139-phosphorylated histone H2AX foci between G2-arrested cells and mitosis-progressing cells, and between mitosis-progressing cells in the presence or absence of ATM or Chk1/2 inhibitor, both of which abrogate IR-induced G2/M checkpoint. The analysis revealed that there was a threshold of DNA damage signal for G2 arrest, which was around 4000~5000 SOID. G2 cells with < 4000 SOID were neglected by G2/M checkpoint, and thus, the cells could progress to mitosis. Chromosome analysis revealed that the checkpoint-neglected and mitosis-progressing cells had approximately two chromatid breaks on average, indicating that 4000~5000 SOID was equivalent to a few DNA double strand breaks.Conclusions: We developed a novel parameter for quantitative analysis of DNA damage signal, and we determined the threshold of DNA damage signal for IR-induced G2 arrest, which was represented by 4000~5000 SOID. The present study emphasizes that not only the foci number but also the size of the foci must be taken into consideration for the proper quantification of DNA damage signal

Deoxidation of Liquid Iron with Silicon

The mechanism of the deoxidation of liquid iron with Si was studied on the basis of the various facts obtained by the following experiments A, B, and C. Experiment A ; An investigation was made of the change in the oxygen content in liquid iron and the shape and the size distribution of the inclusion after the addition of metallic Si. Experiment B ; The process of growth and the composition of the deoxidation products were studied after the prompt and homogeneous dissolution of deoxidizer Si or Si-Al. Experiment C ; The mechanism of dissolution of oxygen from the SiO_2 crucible into liquid iron was studied. (1) The formation of SiO_2 is not completed immediately after the addition of Si, and consequently, the supersaturation in liquid iron occurs until the equilibrium is reached. (2) It was concluded that the growth of oxide particle or the deoxidation reaction was not controlled by the diffusion of the solute atom, but the reaction rate at the particle surface, and in general, the local equilibrium was not maintained there even at steelmaking temperatures. (3) The ratio of the rate constants for the reactions Si+2O→SiO_2 and 2Al+3O→2Al_2O_3 was estimated by means of the composition of the products obtained by the Si-Al deoxidation in experiment B. The ratio was constant in a wide range of the concentration of aluminium, silicon and oxygen in liquid iron. (4) In experiment A, a great part of the primary inclusion float out rapidly and the total oxygen agrees nearly with the dissolved oxygen in 5 minutes after the addition of silicon. (5) The mechanism of the formation of the inclusion during solidification was discussed from the point of the nucleation and growth of oxide particle

Clostridium botulinum Type E Toxins Bind to Caco-2 Cells by a Different Mechanism from That of Type A Toxins

Cultured Clostridium botulinum strains produce progenitor toxins designated as 12S, 16S, and 19S toxins. The 12S toxin consists of a neurotoxin (NTX, 7S) and a non-toxic non-hemagglutinin (NTNH). The 16S and 19S toxins are formed by conjugation of the 12S toxin with hemagglutinin (HA), and the 19S toxin is a dimer of the 16S toxin. Type A cultures produce all 3 of these progenitor toxins, while type E produces only the 12S toxin. The 7S toxin is cleaved into heavy (H) and light (L) chains by a protease(s) in some strains, and the H chain has 2 domains, the N-terminus (Hn) and C-terminus (Hc). It has been reported that type A toxins bind to the intestinal cells or cultured cells via either HA or Hc. In this study, we investigated the binding of type A and E toxins to Caco-2 cells using Western blot analysis. Both the type E 7S and 12S toxins bound to the cells, with the 7S toxin binding more strongly, whereas, in the type A strain, only the 16S/19S toxins showed obvious binding. Pre-incubation of the type E 7S toxin with IgG against recombinant type E Hc significantly inhibited the 7S toxin binding, indicating that Hc might be a main binding domain of the type E toxin