Estimation of mean tree height using small-footprint airborne LiDAR without a digital terrain model

In order to estimate mean tree height using small-footprint airborne light detection and ranging (LiDAR) data, a digital terrain model (DTM), which is a continuous elevation model of the ground surface, is usually required. However, generating accurate DTMs in mountainous forests using only the LiDAR data is laborious and time consuming, because it requires human-assisted methods, especially in the forests with poor laser penetration rates. Based on our previous finding that a hypothetical continuous surface model passing through the predominant tree tops (hereafter, called the “top surface model” or TSM) might be nearly parallel to a DTM, we assumed that the vertical difference between the TSM and the ground return was the mean tree height. According to this assumption, we propose a new methodology that does not require a DTM to estimate mean tree height. This method completely, automatically, and directly estimates mean tree height (MTH _E) from the LiDAR data without requiring a regression analysis using reference data. From the relationships between the MTH _E and the observed mean tree height (MTH _O) in different hinoki cypress forests, we demonstrate that this method effectively estimates the mean tree height with nearly 1-m accuracy.     

Epizootiological study of tick-borne encephalitis virus infection in Japan

Tick-borne encephalitis virus (TBEV) is a zoonotic agent causing severe encephalitis in humans. Rodent species that are potential hosts for TBEV are widely distributed in various regions in Japan. In this study, we carried out large-scale epizootiological surveys in rodents from various areas of Japan. A total of 931 rodent and insectivore sera were collected from field surveys. Rodents seropositive for TBEV were found in Shimane Prefecture in Honshu and in several areas of Hokkaido Prefecture. These results emphasize the need for further epizootiological and epidemiological research of TBEV and preventive measures for emerging tick-borne encephalitis in Japan.     

Early milk availability modulates the activity of choline acetyltransferase in the cerebral cortex of rats

The purpose of the present study was to investigate the effect of milk in the early stage of lactation on the maturation of cholinergic neurons in the cerebral cortex of rats. Pups were removed from their mothers immediately following parturition and placed with foster dams at days 5–7 of lactation. At days 18 and 56 after birth, the activity of choline acetyltransferase (ChAT), an enzyme responsible for acetylcholine synthesis, in different areas of the cerebral cortex was examined by high‐performance liquid chromatography electrochemical detection. In the frontal and hindlimb/parietal regions of the cerebral cortex, the lack of early milk significantly decreased ChAT activity at days 18 and 56. There was no effect on gains in the body or brain weight of infants. ChAT activity in the occipital area tended to be lower in the early milk‐deprived rats. The intake of early milk potentially contributes not only to nutrients for the growth of newborn infants, but also to the functional maturation of the cholinergic neurotransmission system in a region‐specific manner.     

Effects of Controlled-Release Fertilizers and Their Application Methods on Germination and Seedling Growth of Dent and Sweet Corns

Effects of controlled-release fertilizers (CRFs) (C-AS, polyolefin coated ammonium sulfate, 50-day-type; Dd-LP, polyolefin coated urea with dicyandiamide, 40-day-type; C-ANP, polyolefin coated ammonium nitrate phosphate, 40-day-type; and C-DAP, polyolefin coated diammonium acid phosphate, 40-day-type), ammonium sulphate and no fertilizer control, and their application methods (spot, band, surface and mixed) on germination and seedling development of sweet corn (Zea mays L.var. saccharata Sturt.) and dent corn (Zea mays L.var. indentata Sturt.) were investigated in a greenhouse. Under co-situs application (band and spot) of CRFs, there were no obvious differences in the germination speed and rate for both dent corn and sweet corn relative to control. Mortality rates of sweet corn seedlings under co-situs application were high in experiment 1, but were very low in experiment 2, because the environmental conditions were different in the two experiments. That is, under lower temperature and weaker sunlight, young seedlings easily die due to high soil nutrient concentration and slow growth speed of corn. Shoot weight of both dent and sweet corn did not greatly decrease in experiment 1. In experiment 2, there were no significant differences in shoot and root weight of both corns between cositus and surface or mixed application methods. However, with spot and band application of ammonium sulfate, shoot and root weight were significantly reduced. Soil EC and pH were considerably affected by co-situs application, especially at the fertilizer application site. For both dent and sweet corn, EC in the 0-3 cm soil was significantly higher under co-situs application and surface application than that under mixed application, whereas in the 3-6 cm soil depth the situation was reversed. Compared with control, mixed application of CRFs decreased soil pH slightly (0-3 cm depth) or greatly (3-6 cm depth).     

Migration and differentiation of gonadal germ cells under cross-sex germline chimeras condition in domestic chickens

A series of experiments was conducted to investigate migration, proliferation and differentiation of gonadal germ cells (GGCs) collected from the gonads of 7-day-old chick embryos under cross-sex germline chimera conditions. The migratory and proliferative abilities of exogenous GGCs were examined by transferring 50 fluorescently labeled GGCs collected from White Leghorn (WL) embryos into the blood of 2-day-old Rhode Island Red (RIR) embryos. No significant difference was observed in the number of fluorescently labeled GGCs in the gonads of recipient embryos among any of the four possible donor and recipient sex combinations. Cross-sex germline chimeras were produced to examine the differentiation of GGCs by transferring 100 GGCs from WL embryos into 2-day-old RIR embryos. Exogenous-GGC-derived progeny were obtained from both male and female recipients, except when female GGCs were transferred into male recipients. The migratory ability of GGCs recovered from the 7-day-old embryonic gonad was not influenced by cross-sex germ cell transfer conditions, whereas the differentiation of the GGCs was affected by the sex combinations of GGCs donors and recipients.     

Dermal dysplasia characterized by collagen disorder-related skin fragility in a cow

Holstein cow 1 was examined because of skin fragility and delayed healing of skin wounds, which were markedly exacerbated around the time of parturition. A skin biopsy sample was obtained, and light microscopy revealed irregular deposition of thin collagen fibers in a dermal matrix. Although diffuse inflammation did not occur, the number of plump fibroblasts was increased. Electron microscopy revealed poor construction of collagen fibrils in the dermal matrix. Biochemical analysis of the dermis revealed a normal amount of collagen and uronic acid, but sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed an increased proportion of soluble alpha-, beta-, and gamma-collagen chains of normal molecular weights. Neither procollagen nor its intermediates devoid of amino- or carboxy-terminal extension peptide were observed. Dermal collagen from cow 1 was more soluble in a neutral salt solvent, 0.5M acetic acid, and the acid containing pepsin than was dermal collagen from healthy cow 2. The peptic digestion profile of dermis from cow 1 revealed a lowered degree of intermolecular cross-linking and destabilization of helical structure in the dermis collagen. The extrahelical peptic cleavage of collagen before cyanogen bromide digestion resulted in release of more fragments derived from carboxy-terminal part of alpha 1 chains in dermis of cow 1 than in dermis of healthy cow 2.     

Comparative studies on lignin distribution by UV microscopy and bromination combined with EDXA

Summary In order to elucidate a previously reported discrepancy in the ratio of the lignin concentration in the middle lamella to that in the secondary wall as determined by ultraviolet (UV) microscopy and bromination combined with EDXA, the ultraviolet absorptivity of the lignin and the lignin reactivity towards bromination were compared for black spruce wood (Picea mariana Mill.). In addition, UV microscopy and EDXA techniques were applied to the determination of lignin distribution in the tracheids in order to establish the relationship between the two techniques. The results indicated that, although the ultraviolet absorptivity in different morphological regions is essentially the same, the secondary wall lignin was 1.70 times more reactive towards bromination than the middle lamella lignin. By applying the value of 1.70 as a correction to the EDXA results, the estimated lignin distribution by EDXA was in fairly good agreement with that from UV microscopy.The authors would like to thank Dr. J.-F. Revol and Dr. M. Tsuji for their assistance during this study     

Relationship between ball milling and the susceptibility of wood to digestion by cellulase

Summary Aspen wood was ball milled for times as long as 10 days. The change in wood morphology was examined in the ultraviolet microscope. The accessibility of the milled wood to cellulase was also determined. Soon after the commencement of the milling, part of the wood took on a characteristic appearance in which the cell wall material was completely broken down. The proportion of this disordered wall material (DWM) increased with increased time of milling. The accessibility to cellulase increased with the proportion of DWM produced by the milling.The authors wish to acknowledge the interest and valuable advice of Dr. B. A. Pethica throughout the conduct of this research     

Representation of tree stem taper curves and their dynamic, using a linear model and the centroaffine transformation

One main task of forestry is a reliable estimation of the stem form and its development applied in calculating total and log volume. As long as process-oriented models are not available for this practical use, empirical models must serve instead. Taper curve data of trees within stands normally show a rank maintenance,i.e., a tree which has a greater diameter than another one at a certain height, is most probably bigger at any other height, too. This property also applies to the analysed tree species, sugi (Cryptomeria japonica) and hinoki (Chamaecyparis obtusa), and will be well-represented by a linear model formulation. As model parameter sets of single stands have a very limited time validity, two approaches for future stem form prediction are discussed. The one, the centroaffine transformation of a linear taper curve function, is not suitable for representing the time-depending change of the stem form. However, this can be done by a linear unit taper curve model, the parameters of which are based on sample trees of stands of several age classes. Temporary unit parameter sets are derived for sugi and hinoki and the estimated stand volumes are compared to the real ones to evaluate the model performance, which turned out to be very good. We would like to express our gratitude to the Japan Science and Technology Corporation for the financial promotion, which enabled this research work.