Exposure to blue LED light before the onset of darkness under a long‐day photoperiod alters melatonin secretion,feeding behaviour and growth in female dairy calves

The effect of blue LED on melatonin secretion, feeding behaviour and growth was addressed in Holstein female dairy calves. In Exp.1, six animals (8 weeks old, 97 ± 4.1 kg BW) were exposed to yellow or blue LED for 2 hr before darkness over 7 days under a long‐day photoperiod (LDPP). In Exp. 2, six animals (8 weeks old, 88.5 ± 4.8 kg BW) were exposed to blue light from a white LED all daytime or a yellow LED for 2 hr before the darkness of LDPP (blue light cut) over 3 weeks. In Exp. 1, blue light mildly suppressed melatonin secretion during the 2‐hr treatment but did not affect the timing of the nightly melatonin rise. However, the rise in nighty melatonin levels was higher with yellow than blue LED. In Exp. 2, white LED completely suppressed melatonin secretion during the 2‐hr treatment, but plasma melatonin concentrations were similar during the darkness. Grass hay intake, rumination time, frequency of water intake and body weight gain were higher in animals exposed to the yellow rather than the white LED. Overall results indicate that exposure to blue light from white LEDs under an LDPP suppresses melatonin secretion and might negatively impact the development of female dairy calves.     

Microbial reduction mechanism of ferric iron in paddy soils (Part I)

In the previous paper¹⁾ the authors proved that the ferric iron reduction in submerged paddy soils is entirely or mostly effected by the activities of microorganisms in the soil. Prior to the study on the ferric iron reducing microorganisms isolated from the soil, the present paper reports the research for the microbial mechanism of iron reduction. working with the soil itself.     

The reduction mechanism of manganese in paddy soils

Hydroquinone method manganese (soluble in pH 7.0, 1 N-ammonium acetate solution containing 0.2 percent hydroquinone) and microbially active manganese (soluble in pH 7.0, 1 M-magnesium sulfate solution after flooding soils with or without Chinese milk vetch for 12 or 20 days respectively at 30°C) of 22 paddy soils were determined. The amounts of manganese reduced with sodium oxalate under acid conditions (oxalate method manganese (a) and (b), the former was determined under more rigorous conditions than the latter) were also determined and compared with hydroquinone method manganese and microbially active manganese.

Their levels of many soil samples representing soil groups were also determined to examine the dlfferences In amounts of active manganese among soil groups. The results obtained are as follows.

The relationship between microbially and chemically active manganese. 1) The amounts of microbially active manganese in soils were 48 to 68 mg Mn per 100 g oven-dried soil and these were increased by the addition of Chinese milk vetch. 2) The amounts of hydroquinone method manganese were less than microbially active manganese, and the amounts of oxalate method manganese (b) were larger than microbially active manganese. The amounts of oxalate method manganese (a) were the largest of all the types of manganese. 3) There were high correlations between the amounts of various types of active manganese described in 2). The levels of microbially and chemically active manganese. 1) The amounts of microbially active manganese lay between the amounts of chemically active manganese determined by the hydroqulnone method and by the oxalate method (b) In all soil samples representing soil groups. High correlations were found between these types of active manganese. 2) The hydroquinone method was considered to be unsuitable for quantitatively determining the amounts of chemicallY active manganese in soils of high organic matter content. 3) In both cases of microbially active manganese and chemically active manganese, tha widest range and the largest amount determined were both observed in strongly gley soila. The averages of theae types of active manganese were high in strongly gley soils, pea, and muck soils, and black soils. The differences among soil groups were smalle1 than the differences among soil samples, and little tendency was observed in the differences among soil groups.

From these findings described above it is suggested that the oxalate methoo (b) is more appropriate than the hydroqulnone method for determining chemically active manganese as an index of microbially active manganese.     

Effect of flutianil on the morphology and gene expression of powdery mildew

Flutianil, a fungicide effective only on powdery mildew, was previously reported to affect the host cell''s haustorial formation and nutrient absorption. Studies were conducted to investigate flutianil''s primary site of action on Blumeria graminis morphology using transmission electron microscope (TEM) observation and RNA sequencing (RAN-seq) techniques. TEM observation revealed that flutianil caused the extra-haustorial matrix and fungal cell wall to be obscured, without remarkable changes of other fungal organelles. RNA-seq analysis indicated that, unlike other powdery-mildew fungicides, flutianil did not significantly affect the constantly expressed genes for the survival of B. graminis. Genes whose expression is up- or downregulated by flutianil were found; these are the three sugar transporter genes and various effector genes, mainly expressed in haustoria. These findings indicate that the primary site of action of flutianil might be in the haustoria.     

Antiproliferative and antiangiogenic activities of smenospongine, a marine sponge sesquiterpene aminoquinone

We previously reported that smenospongine, a sesquiterpene aminoquinone isolated from the marine sponge Dactylospongia elegans, showed antiproliferative or cytotoxic activities on leukemia cells. In this study, we investigated the effect of smenospongine on solid tumors. Since angiogenesis is well known to be closely involved in growth and metastasis of solid tumors, the antiangiogenic effect of smenospongine was determined. We found that smenospongine inhibited proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVEC). Moreover, the inhibitory activity of smenospongine on growth of solid tumor cells was investigated. Smenospongine inhibited the growth of 39 human solid cancer cells in vitro, with a mean Log GI(50) value of -5.55. In conclusion, smenospongine exhibits antitumor activity on solid tumors via two mechanisms, an antiangiogenic effect on endothelial cells and direct inhibition of growth of tumor cells.     

Anatomical characterization of decayed wood in standing light red meranti and identification of the fungi isolated from the decayed area

To further our understanding of wood decay in living light red meranti (Shorea smithiana) trees, microscopic characteristics of the cell and cell wall degradations of S. smithiana wood in the presence of the decay fungi, the identity of the causal fungi, and the decay potential and pattern by an isolated fungus were investigated. Cell wall degradations, including cell wall thinning, bore holes formation, rounded pit erosion, and eroded channel opening were clearly observed under light and scanning electron microscopy. In transverse view, many large voids resulting from a coalition of degraded wood tissue appeared in the decayed canker zone. All these observations suggest the well-known simultaneous decay pattern caused by white-rot fungi. By phylogenetic analysis based on the sequences of internal transcribed spacer region of ribosomal DNA, a basidiomycete fungus isolated from the decayed wood was identified as Schizophyllum commune. The degradation caused by this fungus on sound S. smithiana wood in an in situ laboratory decay test was classified as the early stage of simultaneous decay, and showed a similar pattern to that observed in the wood samples naturally decayed.     

Characterization of an Alginate Lyase,FlAlyA, from Flavobacterium sp. Strain UMI-01 and Its Expression in Escherichia coli

A major alginate lyase, FlAlyA, was purified from the periplasmic fraction of an alginate-assimilating bacterium, Flavobacterium sp. strain UMI-01. FlAlyA showed a single band of ~30 kDa on SDS-PAGE and exhibited the optimal temperature and pH at 55 °C and pH 7.7, respectively. Analyses for substrate preference and reaction products indicated that FlAlyA was an endolytic poly(mannuronate) lyase (EC 4.2.2.3). A gene fragment encoding the amino-acid sequence of 288 residues for FlAlyA was amplified by inverse PCR. The N-terminal region of 21 residues except for the initiation Met in the deduced sequence was predicted as the signal peptide and the following region of six residues was regarded as propeptide, while the C-terminal region of 260 residues was regarded as the polysaccharide-lyase-family-7-type catalytic domain. The entire coding region for FlAlyA was subjected to the pCold I—Escherichia coli BL21(DE3) expression system and ~eight times higher yield of recombinant FlAlyA (recFlAlyA) than that of native FlAlyA was achieved. The recFlAlyA recovered in the periplasmic fraction of E. coli had lost the signal peptide region along with the N-terminal 3 residues of propeptide region. This suggested that the signal peptide of FlAlyA could function in part in E. coli.     

Recent advances in the high-density rotifer culture in Japan

The success of rapidly growing aquaculture industry depends on the steady supply of fish seeds. Appropriate food for initial larval stages is critical for mass scale fish seed production. Live food found better over artificial food for fish larvae culture. Rotifers have been found to be the best live food for feeding fish larvae in early life stage. Attempts have been made to develop viable techniques for the production of rotifer through batch, continuous, and semi-continuous culture methods. In order to feed increased number of fish larvae, rotifer need to be cultured under high-density method. Various efforts have been made for increasing culture density of rotifer. In Japan, stable high-density culture of rotifer has been developed in commercial scale at a rate of 20,000–30,000 ind. ml^?1. Later on, ultra-high-density rotifer culture (160,000 ind. ml^?1) was found successful, which can fulfill the increased demand for rotifer as fish larval food. Furthermore, a scope of alternative use of rotifer can be explored. The development of the high-density rotifer culture method in Japan has been reviewed. The considerations of the associated nutritional requirements, microbial aspects, and prospects of high-density culture have been discussed.     

Analysis of strigolactones,germination stimulants for striga and orobanche,by high-performance liquid chromatography/tandem mass spectrometry

A simple and rapid analytical method for strigolactones, germination stimulants for the root parasitic weeds witchweed (Striga spp.) and broomrape (Orobanche spp.), has been developed using high-performance liquid chromatography connected to tandem mass spectrometry (LC/MS/MS). The natural strigolactones (strigol, sorgolactone, orobanchol, and alectrol) were clearly separated and identified by LC/MS/MS. As low as 0.1 pg/microL of strigol and 0.5 pg/microL of sorgolactone could be quantified, whereas 1 pg/microL was needed for the quantification of orobanchol (S/N > 10). Using this method, it was found that red clover produces orobanchol and alectrol but not strigol. The roots of red clover seedlings were found to produce 13, 70, 58, and 65 pg of orobanchol/plant 1, 2, 3, and 4 weeks after germination, respectively.     

An index for evaluating the flood-prevention function of paddies

Urbanization is expanding in and around small to medium-sized cities as well as in large cities, and the expansion includes low-lying areas where the flood risk is high. Flood risk in small watersheds has been evaluated using precise mathematical models. However, these models cannot be applied to larger basins due to the complexity of data collection and analysis. As a result, quantitative evaluations of flood risk at macro scales and the flood-prevention function of paddies around urban areas have not been made. This paper proposes a method and an index that can be used to evaluate the flood-prevention function of paddies on a regional scale. In addition, the use of this system for basin-wide management is illustrated by an example for the Kinu and Kokai rivers, which are tributaries of the Tone River of Japan. The applicability of the approach is evaluated using data from a major flood that occurred in the study area.