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.     

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.     

Malignant glomus tumour in a German shepherd dog

A solitary mass, 2.5 cm × 2.5 cm × 2.0 cm in size, was found in the subcutis adjacent to the ischial tuberosity of an 8-year-old male German shepherd dog. The excised mass was not encapsulated and the cut surface was solid, grey–white and had multiple red areas suggestive of haemorrhage. Microscopically, the neoplasm was composed of epithelioid cells interspersed with venous vessels of various sizes and irregular bundles of spindle-shaped tumour cells with mucinous stroma. The nuclei showed anisokaryosis and many mitotic figures were noted. Immunohistochemically, the majority of tumour cells were positive for alpha smooth-muscle actin and vimentin, but negative for cytokeratin, desmin, S-100 and factor VIII-related antigen. Ultrastructurally, the tumour cells contained irregular nuclei, few mitochondria, few rough endoplasmic reticulum, cytoplasmic myofilaments of intermediate density, pinocytotic vesicles and distinct basal lamina. Based on these pathological findings, the diagnosis was malignant glomus tumour.     

Arbuscular mycorrhizal fungal communities associated with some pioneer plants in the lahar area of Mt. Pinatubo,Philippines

An extensive area has been buried due to the repeated occurrence of mud flows (lahars) derived from volcanic deposits during the eruption of Mt. Pinatubo in the Philippines. Most of the area was covered with sparse vegetation consisting of only a few gramineous pioneer plants such as Saccharum spontaneum (site SV). However dense vegetation consisting of wild leguminous plants such as Calpogonium mucunoides showed a patch distribution (site DV). In 1999, we investigated the community composition of AMF at these two sites. S. spontaneum at both sites was slightly colonized with AMF while the leguminous plants were highly colonized. Spores of AMF were collected from the rhizosphere of these plants. Eight spore morphotypes were identified; one each for Acaulospora and Entrophospora colombiana, two for Glomus, one for Paraglomus, and three for Scutellospora. Part of the 18S rRNA gene of AMF colonizing the plant roots was amplified with AMF-specific primers, NS31 and AM1, cloned and sequenced. Fifty-three AMF clones were phylogenetically classified into 8 phylotypes as follows: one each for Acaulospora and E. colombiana, five for Glomus, and one for Scutellospora. Both molecular and morphological examinations showed that the diversity of AMF was comparable to that in other temperate ecosystems with abundant vegetation and did not differ significantly between sites SV and DV, regardless of the vegetation cover. Furthermore, S. spontaneum supported diverse AMF species in spite of its scant growth at site SV. E. colombiana was mostly associated with C. mucunoides. Significance of AMF for the primary plant succession in the lahar area was analyzed.     

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.     

The use of artificial temporary streams with and without shelters by Japanese dace Tribolodon hakonensis

SUMMARY: In order to know how fish use temporary streams, we set up artificial temporary streams with and without shelters and investigated the fish that colonized there from connected permanent streams. A total of 220 fish belonging to six species were captured over four sampling periods from May to September, with Japanese dace Tribolodon hakonensis being the most abundant (75%). More Japanese dace colonized the stream with shelters than without shelters. The standard length and condition of Japanese dace tended to be greater in the stream with shelters than without shelters. Foraging behavior and area of Japanese dace differed significantly between the two streams; more Japanese dace employing drift feeding near the entrance of the shelterless stream. Japanese dace predominantly fed upon chironomid larvae, which became abundant in stream mud in July. However, in August and September, Japanese dace rarely preyed upon chironomid larvae and their digestive canal fullness was low, probably because most chironomid larvae had been consumed. This tendency was more prominent in the stream with shelters. The use of temporary waters by Japanese dace changed dynamically in response to the abundance of chironomid larvae and the presence or absence of shelters.     

Preserving boiled eggs with a sterilization system employing microbial laccase and wood vinegar

A combination of a microbial laccase and wood vinegar was used to treat the shell surface of boiled eggs. The laccase enhanced the sterilization effect of phenolic compounds contained in the wood vinegar and resulted in prevention of microbial infection of the boiled eggs after storage for 21 days at 40°C and 75% relative humidity. Significant phenoxy radicals, formed by the catalytic reaction of the laccase, could be detected in the shell of the boiled eggs.     

A pathological study of the salivary glands of rabid dogs in the Philippines

Rabies is a zoonotic disease caused by the rabies virus. While the salivary glands are important as exit and propagation sites for the rabies virus, the mechanisms of rabies excretion remain unclear. Here, we investigated the histopathology of the salivary glands of rabid dogs and analyzed the mechanism of excretion into the oral cavity. Mandibular and parotid glands of 22 rabid dogs and three control dogs were used. Mild to moderate non-suppurative sialadenitis was observed in the mandibular glands of 19 of the 22 dogs, characterized by loss of acinar epithelium and infiltration by lymphoplasmacytic cells. Viral antigens were detected in the mucous acinar epithelium, ganglion neurons and myoepithelium. Acinar epithelium and lymphocytes were positive for anti-caspase-3 antibodies and TUNEL staining. In contrast, no notable findings were observed in the ductal epithelial cells and serous demilune. In the parotid gland, the acinar cells, myoepithelium and ductal epithelium all tested negative. These findings confirmed the path through which the rabies virus descends along the facial nerve after proliferation in the brain to reach the ganglion neurons of the mandibular gland, subsequently traveling to the acinar epithelium via the salivary gland myoepithelium. Furthermore, the observation that nerve endings passing through the myoepithelium were absent from the ductal system suggested that viral proliferation and cytotoxicity could not occur there, ensuring that secretions containing the virus are efficiently excreted into the oral cavity.     

Reactive oxygen species (ROS) generation and ROS-induced lipid peroxidation are associated with plasma membrane modifications in host cells in response to AK-toxin I from Alternaria alternata Japanese pear pathotype

AK-toxin I caused plasma membrane modifications with plasma membrane-derived membrane fragments only in sensitive Japanese pear tissues. H₂O₂ generation was abundant in both the membrane fragments and the plasma membranes of the toxin-treated sensitive tissues. Whether lipid peroxidation was induced in plasma membranes of the toxin-treated sensitive tissues was examined biochemically and histochemically. Lipid peroxidation was caused only in the toxin-treated sensitive tissues or the toxin-treated plasma membrane-enriched fractions from sensitive young pear fruits. The results indicated that the peroxidation was probably induced by reactive oxygen species in the modified plasma membranes by action of toxin, suggesting that peroxidation is closely associated with plasma membrane modifications.     

Temporal changes in liver tissue metabolome of lambs fed low‐quality roughage

Early experience with low‐quality roughage may induce adaptations in ruminants’ metabolism. This study was conducted to explore the variation in the hepatic metabolomes of lambs fed low‐quality roughage beginning early in life. Five lambs were fed Sudan grass hay (crude protein (CP): 4.6% of the dry matter (DM), neutral detergent fiber, 68.5% of DM) for 6 months during time periods P1, P2 and P3, which consisted of 2 months each. The metabolizable energy (ME) and CP intake satisfied lambs’ maintenance requirements in P1 and P2, but the ME intake was 78.5% of the maintenance ME requirement in P3. Liver metabolomics was carried out in P2 and P3 by the capillary electrophoresis and time‐of‐flight mass spectrometry system. Eight amino acids and six amino acid metabolism‐related metabolites were altered between P2 and P3. Several intermediates of glycolysis/gluconeogenesis decreased, while nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate increased in P3. Taurocholic acid and taurine increased, while glycocholic acid decreased in P3. The results suggested that amino acid utilization and the efficiency of glycolysis/gluconeogenesis might be adjusted to accommodate the low‐quality roughage fed to the lambs during early stages of life. The composition of bile acids might also be optimized to promote the efficiency of lipid absorption.