Estimation of the canopy-gap size using two photographs taken at different heights

A new, convenient method to estimate canopy-gap size using a camera is proposed. Canopy-gap size was estimated from two images taken with a vertically mounted, digital camera at high and low points (P_h and P_l) beneath a canopy gap. The actual (A_OBS) and estimated (A_1.0) canopy-gap sizes were highly correlated (R² > 0.93) for 16 canopy gaps in the Cryptomeria japonica D. Don. plantations, and the relationship between A_1.0 and A_OBS was expressed as A_1.0 = 1.16A_OBS. Thus, the method overestimated actual canopy-gap size by an average of 16%.     

Identification of a new gene responsible for the oxygen tolerance in aerobic life of Streptococcus mutans

Alkyl hydroperoxide reductase in Streptococcus mutans consists of two components, Nox-1 and AhpC. Deletion of nox-1 and ahpC in a double mutant as well as the wild-type of Streptococcus mutans can form colonies in the presence of air to the same extent. The evidence suggested the presence of some other antioxidant system(s) independent of the Nox-1/AhpC system in the bacterium. Here we identified a new antioxidant gene (dpr) and the gene product (Dpr) which complements the defect of peroxidase activity caused by the deletion of nox-1 and ahpC in S. mutans. The dpr-disruption mutant of S. mutans could form colonies anaerobically but not aerobically.     

Glycosidic fraction of flue-cured tobacco leaves: its separation and component analysis

The fraction containing glycosidic components was separated from flue-cured tobacco (Nicotiana tabacum L.) leaves by a facile method. Some components of the fraction were isolated and elucidated to be syringin, coniferin, cichoriin, benzyl-beta-D-glucoside, Blumenol A-beta-D-glucoside, and 5,6-epoxy-5,6-dihydro-3-hydroxy-beta-ionyl-beta-D-glucoside. Syringin and coniferin were detected in the Nicotiana species for the first time.     

An antibiotic from Penicillium sp. covering the cocoon of the leaf-rolling moth, Dactylioglypha tonica

An antibiotic-producing Penicillium sp. strain was isolated from cocoons of the leaf-rolling moth, Dactylioglypha tonica. An antibacterial compound was isolated from the cultured broth, and the chemical structure of the principle was determined by spectroscopic data to be a derivative of isocoumarincarboxylate.     

Laryngeal endocrine cells: topographic distribution and adaptation to chronic hypercapnic hypoxia

The morphology, topographic distribution, effects of denervation, and exposure to hypercapnic hypoxia of endocrine cells were examined in rat larynx. The endocrine cells, which were immunoreactive for protein gene product 9.5 (PGP 9.5) and calcitonin gene-related peptide (CGRP), were observed within the epithelial layer of the laryngeal cavity and in the laryngeal gland, while solitary endocrine cells with apical and/or basal cytoplasmic processes appeared near the glottis. After denervation of the left cervical vagosympathetic trunk and the superior laryngeal nerve, the number of mucosal endocrine cells in the denervated side was not significantly different from that in the intact side. After exposure to hypercapnic hypoxia for 3 months, the number of endocrine cells with PGP 9.5 and CGRP was markedly increased. In conclusion, the secretion of laryngeal endocrine cells may be stimulated by CO2 rather than O2. Furthermore, the endocrine cells and the sensory and autonomic nervous system may regulate each other by an axon reflex mechanism. Endocrine cells appear to play a very important role in the local regulation of the laryngeal mucosa.     

Bioactive peptides derived from food proteins preventing lifestyle-related diseases

Many kinds of bioactive peptides which might prevent lifestyle-related diseases are released from food proteins after enzymatic digestion. Inhibitory peptides for angiotensin I-converting enzyme (ACE) having anti-hypertensive effect have been isolated from enzymatic digests of various food proteins. LKPNM, which was isolated from the thermolysin digest of dried bonito was activated 8-fold by ACE itself and showed a prolonged effect after oral administration. Two vasorelaxing peptides, ovokinin and ovokinin(2-7), showing antihypertensive effect after oral administration were obtained from ovalbumin digests. We found that low molecular weight peptides derived from food proteins lowered serum cholesterol without increasing excretion of cholesterol and bile acids. An immunostimulating peptide isolated from an enzymatic digest of soybean protein prevented alopecia induced by cancer chemotherapy.     

A Robertsonian translocation, rob(2;28), found in Vietnamese cattle

A new Robertsonian translocation, rob(2;28), was discovered in a local population of the Vietnamese Cattle. The animal (2n = 59, XY) was found by Q- and R-banding to be a heterozygous carrier of a centric fusion translocation involving chromosomes 2 and 28. FISH analysis using a bovine satellite I DNA probe demonstrated that the centromeric heterochromatin block of the rob(2;28) chromosome become much smaller than its ancestors suggesting a monocentric nature of this centric fusion. This is the first report identifying a Robertsonian translocation in Southeast Asian cattle by karyotyping of banded chromosomes.     

Identification of heading date quantitative trait locus Hd6 and characterization of its epistatic interactions with Hd2 in rice using advanced backcross progeny

A backcrossed population (BC(4)F(2)) derived from a cross between a japonica rice variety, Nipponbare, as the recurrent parent and an indica rice variety, Kasalath, as the donor parent showed a long-range variation in days to heading. Quantitative trait loci (QTL) analysis revealed that two QTL, one on chromosome 3, designated Hd6, and another on chromosome 2, designated Hd7, were involved in this variation; and Hd6 was precisely mapped as a single Mendelian factor by using progeny testing (BC(4)F(3)). The nearly isogenic line with QTL (QTL-NIL) that carries the chromosomal segment from Kasalath for the Hd6 region in Nipponbare's genetic background was developed by marker-assisted selection. In a day-length treatment test, the QTL-NIL for Hd6 prominently increased days to heading under a 13.5-hr day length compared with the recurrent parent, Nipponbare, suggesting that Hd6 controls photoperiod sensitivity. QTL analysis of the F(2) population derived from a cross between the QTL-NILs revealed existence of an epistatic interaction between Hd2, which is one of the photoperiod sensitivity genes detected in a previous analysis, and Hd6. The day-length treatment tests of these QTL-NILs, including the line introgressing both Hd2 and Hd6, also indicated an epistatic interaction for photoperiod sensitivity between them.