Stereoselective syntheses of all stereoisomers of lariciresinol and their plant growth inhibitory activities

All stereoisomers of lariciresinol were synthesized to examine the effect of stereochemistry on plant growth. Configuration of benzylic 7-positions was constructed through S(N)1 or S(N)2 intramolecular etherification. 8- and 8'-position configurations were established from the starting material except for all cis stereoisomers, the 8-position configurations of which were achieved by employing stereoselective hydroboration. (-)-Lariciresinol and its 7S,8S,8'R stereoisomer inhibited the root growth of Italian ryegrass to 51-55% relative to the negative control, whereas other stereoisomers had less effect. These results demonstrate that the stereochemistry of lignans is one of the important factors influencing their inhibitory activity.     

A complex with chromatin modifiers that occupies E2F- and Myc-responsive genes in G0 cells

E2F-6 contributes to gene silencing in a manner independent of retinoblastoma protein family members. To better elucidate the molecular mechanism of repression by E2F-6, we have purified the factor from cultured cells. E2F-6 is found in a multimeric protein complex that contains Mga and Max, and thus the complex can bind not only to the E2F-binding site but also to Myc- and Brachyury-binding sites. Moreover, the complex contains chromatin modifiers such as a novel histone methyltransferase that modifies lysine 9 of histone H3, HP1gamma, and Polycomb group (PcG) proteins. The E2F-6 complex preferentially occupies target promoters in G0 cells rather than in G1 cells. These data suggest that these chromatin modifiers contribute to silencing of E2F- and Myc-responsive genes in quiescent cells.     

片切磨削方法构造的自由曲面磨削支持系统

以操作者高效准确操作数控磨削中心为目的，开发了自由曲面磨削支持系统，进行了基于球头磨具的磨削中心基础研究。讨论了获得高精度曲面的加工要点，并提出了片切磨削方法。     

Impact of clod (aggregate) size on evaporation rate and soil moisture profile during the drying process

Large clods (centimetres in size) can be formed by tillage in clayey paddy fields where upland crops are planted. These clods cause early water depletion near the soil surface, which decreases crop germination and emergence rates. Because of the difficulty in reducing clod size, desiccation damage to seeds can be avoided by adjusting the seeding depth based on the clod size-dependent soil moisture profile. This study aimed to clarify the effect of clod size on (1) the evaporation rate (E) and soil moisture profile and (2) the mobility of soil water during the drying process. Evaporation experiments were conducted in an air-conditioned greenhouse with natural light using cylindrical columns filled with artificially made clods 3 (L columns) and 1 cm (S columns) in diameter. We measured E, potential evaporation rate (PE), and total soil moisture content (w_tot) throughout the experiment and the soil moisture profiles at the end of the experiment. The water diffusivity (D_w) and apparent vapour diffusion coefficient (d_vap) were calculated as the mobility of soil water and water vapour, respectively. We found that w_tot was lower in the L column than in the S column, although not at the onset of the experiment. At the end of the experiment, the soil moisture content was lower in the L column than in the S column throughout the soil layer. In contrast, E/PE was higher in the L column than in the S column throughout the experiment and even at the same w_tot. Regarding mobility, D_w was slightly greater in the L column than in the S column in the soil moisture content range, where vapour movement could be greater than liquid water movement. In addition, the ratio of d_vap to the diffusion coefficient of water vapour in soil was higher than unity in both columns and was 2.4–3.2 times higher in the L column than in the S column. In summary, larger clods caused a higher evaporation rate and lower soil moisture content, owing to the increased enhancement of water vapour movement probably induced by wind.     

cDNA cloning of Japanese oyster stress protein homologous to the mammalian 78-kDa glucose regulated protein and its induction by heatshock

ABSTRACT:    The 78-kDa glucose regulated protein (GRP78), a member of stress proteins, was cloned from a cDNA library of Japanese oyster Crassostrea gigas . The analysis on Japanese oyster GRP78 clone of approximately 2.6 kb revealed that the entire open reading frame was 1983 bp long and encoded 661 amino acid residues. At the DNA sequence level, the coding region of Japanese oyster GRP78 gene was 72, 62, and 62% identical to those of chicken GRP78, Japanese flounder HSP70, and Japanese flounder HSC71 genes, respectively. Deduced amino acid sequence of Japanese oyster GRP78 was 84, 62, and 62% identical to those of chicken GRP78, Japanese flounder HSP70, and Japanese flounder HSC71, respectively. Japanese oyster GRP78 contained an 18-residue sequence at the N-terminus that exhibits characteristics of a cleavable signal sequence. It also contained an ATPase domain, and a peptide-binding domain in addition to a Lys-Asp-Glu-Leu (KDEL) peptide motif that is involved in determining endoplasmic reticulum localization. Northern blot analysis showed that GRP78 mRNA was induced with heatshock treatment in the oyster tissues.     

Differing body size between the autumn and the winter–spring cohorts of neon flying squid (Ommastrephes bartramii) related to the oceanographic regime in the North Pacific: a hypothesis

The neon flying squid (Ommastrephes bartramii), which is the target of an important North Pacific fishery, is comprised of an autumn and winter–spring cohort. During summer, there is a clear separation of mantle length (ML) between the autumn (ML range: 38–46 cm) and the winter–spring cohorts (ML range: 16–28 cm) despite their apparently contiguous hatching periods. We examined oceanic conditions associated with spawning/nursery and northward migration habitats of the two different‐sized cohorts. The seasonal meridional movement of the sea surface temperature (SST) range at which spawning is thought to occur (21–25°C) indicates that the spawning ground occurs farther north during autumn (28–34°N) than winter–spring (20–28°N). The autumn spawning ground coincides with the Subtropical Frontal Zone (STFZ), characterized by enhanced productivity in winter because of its close proximity to the Transition Zone Chlorophyll Front (TZCF), which move south to the STFZ from the Subarctic Boundary. Hence this area is thought to become a food‐rich nursery ground in winter. The winter–spring spawning ground, on the other hand, coincides with the Subtropical Domain, which is less productive throughout the year. Furthermore, as the TZCF and SST front migrate northward in spring and summer, the autumn cohort has the advantage of being in the SST front and productive area north of the chlorophyll front, whereas the winter–spring cohort remains to the south in a less productive area. Thus, the autumn cohort can utilize a food‐rich habitat from winter through summer, which, we hypothesize, causes its members to grow larger than those in the winter–spring cohort in summer.     

Plasma cortisol and prolactin secretion rhythms in cattle under varying external environments and management techniques

The secretion rhythms of plasma cortisol (CORT) and prolactin (PRL), hormones related to stress responsiveness and biological rhythm and controlled by light and temperature, were investigated under varying external environments and different management techniques. Serial blood samples were collected from female cattle reared in free‐stall and freely fed (FF) conditions (n = 4) or in tie‐stall and restricted feeding (RF) conditions (hay and concentrate twice daily, n = 4). Plasma CORT and PRL concentrations, eating behavior, and environmental parameters were analyzed. Cyclic patterns for each parameter were examined using spectral analysis, and correlations between CORT, PRL and other parameters were investigated using cross‐spectral analysis. Under FF conditions, CORT secretion was not related to the lighting intensity and eating behavior. However, under RF conditions, the CORT secretion rhythm showed a distinct correlation with lighting intensity and eating behavior. Under FF conditions, the PRL secretion rhythm was similar in all seasons. However, under RF conditions, the PRL rhythm oscillated with high frequency in summer and low frequency in winter, indicating a seasonal change in rhythm. The present study demonstrates that hormone secretion rhythms change under different environments and management techniques.     

Properties of alkaline‐hydrolyzed waterfowl feather keratin

The properties of hydrolyzed feather keratin (HFK) were compared to those of hydrolyzed wool keratin (HWK) with the aim of developing better ways to utilize feather keratin waste. Amino acid analysis showed that HFK contained more hydrophobic amino acids did than HWK. Although gel permeation chromatography indicated that HFK and HWK had more low‐molecular weight peptides than their intact sources, Fourier transform infrared spectroscopy indicated that both hydrolyzed keratins retained their original secondary structure. The physical properties of HFK were evaluated by treating HFK to human hair fibers. HFK treatment enhanced significantly the surface hydrophobicity and strength of fibers, and HFK was more permeable into hair fibers. These results suggest that HFK is suitable for industrial applications to improve fibers. In addition, HFK may be suitable for raw material of products requiring both flexibility and hydrophobicity, such as films and biodegradable plastics.     

Toluene Exposure Leads to a Change in Expression Patterns of β Defensins in the Mouse Tracheal Epithelium

Defensins are generally implicated in the quick resistance of epithelial surfaces to microbials; however, recent reports have indicated that defensins also have unknown purposes in relation to noninfectious diseases. In this study, the localization patterns of anti-microbial peptides, β defensins (BDs), in the tracheal epithelium of male C3H mice under exposure to toluene were analyzed by immunohistochemistry. Mice were exposed one to ten times to toluene for 30 min by nose-only inhalation. Expression of BDs was revealed by immunohistochemistry in serial sections of trachea after the final exposure. Expression of BD-1 was usually observed at almost the same levels in all exposure groups, and expression of BD-2 was observed in the control group; however, the signals for BD-2 decreased gradually with frequency of exposure. In the group exposed ten times, expression of BD-2 decreased to far lower than that of the control group. No expression of BD-3 was detected in any groups. Interestingly, expression of BD-4 increased to the maximum in the group exposed four times and decreased to a level lower than that of the control in the group exposed ten times. The results of the present study indicated that toluene gas might change the expression pattern of BDs in the tracheal epithelial cells. The oscillation of expression of BD-4 was quite characteristic and might contribute to morphological damage in on the epithelial cells.