Performance of samama (Anthocephalus macrophyllus) LVL based on veneer thickness,juvenile proportion and lay-up

ABSTRACT

A study to determine the quality of laminated veneer lumber (LVL) from samama wood (Anthocephalus macrophyllus) was carried out. Samama is a fast-growing endemic wood in eastern Indonesia. Factorial of three factors in RAL design was used to investigate the influence of veneer thickness, juvenile proportion and veneer lay-up to the quality of the resulted samama LVL. The veneer thicknesses were 1.5 and 3.0?mm. Juvenile proportions were arranged in five levels, which were 100% of juvenile veneer, 100% of mature veneer and combination of both juvenile and mature with juvenile proportion of 14%, 43% and 71%. Two veneer lay-up used in this study were loose side met loose side and tight side met loose side. The result of the study showed various specific gravity of LVL by different proportions of juvenile. This factor also affected the other physical traits. Shear strength of the LVL was equal to the solid wood, yet MOE and MOR were affected by juvenile proportion and veneer lay-up. LVL developed from 100% of mature veneer exhibited the highest MOE and MOR, yet no significant difference was noted in MOE and MOR between LVL 100% of juvenile and other tested juvenile proportions.     

Pseudorabies virus infection in hunting dogs in Oita,Japan: Report from a prefecture free from Aujeszky’s disease in domestic pigs

We isolated two pseudorabies virus (PRV) isolates (designated OT-1 and OT-2) from two hunting dogs exhibiting neurological manifestations after eating the flesh of wild boar hunted in Oita prefecture, Kyushu Island, Japan. The isolates corresponded to a previously reported PRV (MY-1 strain) isolated from a hunting dog in neighboring Miyazaki prefecture, and it clustered into genotype II based on the glycoprotein C sequence. Our results suggest that this common PRV strain may have been maintained in wild boars on Kyushu Island even though domestic pigs in this area have attained an Aujeszky’s disease-free status.     

Azolla incorporation and dual cropping influences CH4 and N2O emissions from flooded paddy ecosystems

ABSTRACT

To investigate the influence of Azolla (A. filiculoides Lam.) incorporated as a green manure and its subsequent growth as a dual crop with rice on simultaneous methane (CH₄) and nitrous oxide (N₂O) emissions from a flooded alluvial soil planted with rice, a pot experiment with three treatments, chemical fertilizers (NPK) as the control, incorporation of Azolla as green manure (AGM), and AGM plus basal chemical fertilizers (NPK+AGM) was conducted in Tsuruoka, Yamagata, Japan in 2017. AGM and NPK+AGM treatments significantly increased CH₄ emissions at early rice growth stages before 63 days after transplanting (DAT) by 123.0% and 176.7% compared to NPK, respectively. At late rice growth stages (after 63 DAT), only the NPK+AGM treatment significantly increased CH₄ emission by 22.1% compared to NPK. However, percentage of CH₄ emitted after 63 DAT relative to the seasonal CH₄ emission followed the order of NPK (86.2%) > AGM (76.5%) > NPK+AGM (73.3%). Higher CH₄ emissions from AGM and NPK+AGM before 63 DAT were attributed to the incorporated Azolla, while the higher emissions after 63 DAT in all treatment groups were ascribed to rice photosynthesis. AGM and NPK+AGM treatments significantly decreased N₂O emissions by 71.6% and 81.1% compared to NPK, respectively, at early rice growth stages. Azolla incorporation may have restricted N₂O emission from initial soil nitrate before 63 DAT and not have contributed to N₂O emissions after 63 DAT. Significantly higher grain yields were observed under the AGM (32.5%) and NPK+AGM (36.3%) compared to NPK. Together, AGM and NPK+AGM treatments significantly increased seasonal CH₄ emissions by 31.5% and 43.5%, and decreased seasonal N₂O emissions 3.4- and 4.6- fold compared to NPK, respectively. There were no significant differences in the CH₄ emissions per grain yield among the treatments; however compared to NPK, AGM and NPK+AGM treatments significantly reduced N₂O emissions per grain yield by 78.7% and 84.1%, respectively.     

The spleen morphophysiology of fruit bats

Spleen is one of the important lymphoid organs with wide variations of morphological and physiological functions according to species. Morphology and function of the spleen in bats, which are hosts to several viral strains without exhibiting clinical symptoms, remain to be fully elucidated. This study aims to examine the spleen morphology of fruit bats associated with their physiological functions. Spleen histological observations were performed in three fruit bats species: Cynopterus titthaecheilus (n = 9), Rousettus leschenaultii (n = 3) and Pteropus vampyrus (n = 3). The spleens of these fruit bats were surrounded by a thin capsule. Red pulp consisted of splenic cord and wide vascular space filled with blood. Ellipsoids in all three studied species were found numerously and adjacent to one another forming macrophages aggregates. White pulp consisted of periarteriolar lymphoid sheaths (PALS), lymphoid follicles and marginal zone. The lymphoid follicle contained a germinal centre and a tingible body macrophage that might reflect an active immune system. The marginal zone was prominent and well developed. This study reports some differences in spleen structure of fruit bats compared to other bat species previously reported and discusses possible physiological implications of the spleen based on its morphology.     

Bondability of tropical fast-growing tree species I: Indonesian wood species

To estimate the potential bonding performance of bonded wood products from tropical fast-growing tree species, a study on the bondability of Paraserianthes falcataria L. Nielsen, Pinus merkusii Jungh et. De. Vriese, and Acacia mangium Willd from Indonesia was conducted. Two-ply laminations were produced using polyvinyl acetate emulsion (PVAc), urea formaldehyde (UF), resorcinol formaldehyde (RF), and water-based polymer isocyanate (API) adhesives. In order to determine the bonding performance, the block-shear test was applied according to the Japanese Agricultural Standard for structural glued laminated timber under normal conditions and after accelerated-aging treatments. To support this study, the wettability of each wood species was also investigated through contact-angle measurement. The results showed that the bonding performance of low-density P. falcataria was better than that of medium-density P. merkusii and medium-density A. mangium, while the bonding performance of medium-density P. merkusii was better than that of medium-density A. mangium. Furthermore, compared with A. mangium, the small contact angle and good wettability in P. falcataria and P. merkusii result in better adhesion and more intimate contact between the wood surfaces and adhesive.     

Bondability of tropical fast-growing tree species III: curing behavior of resorcinol formaldehyde resin adhesive at room temperature and effects of extractives of <Emphasis Type="Italic">Acacia mangium</Emphasis> wood on bonding

The effects of curing time at room temperature and methanol extracts from Acacia mangium on the curing behavior of resorcinol formaldehyde (RF) adhesive were examined by using the thermomechanical analysis spring method. For a specimen that was cured for 3 months at room temperature, the relative elasticity (E _r) curve did not change to a hard glass state from room temperature to 200°C and the adhesive had cured completely. The initial temperature of the reactive zone for chemical and mechanical changes was 15° and 25°C higher than that for the control when 10 and 15 parts by weight methanol extract was added to the liquid adhesive, respectively. It appears that the extractives of A. mangium in RF adhesive interferes with the chemical cure of the adhesive. It is suggested that a combination of curing time and sweeping by methanol on the laminae surface can improve the bonding performance of A. mangium laminates bonded with RF at room temperature.     

Vulnerability of marine resources to small‐scale fishing in a tropical area: The example of Sunda Strait in Indonesia

Although small‐scale fisheries (SSF) play an important socio‐economic role in developing nations, overfishing seems to be increasing the risk of stock vulnerability. This study aims to quantify the pressure of SSF on fish stocks in Sunda Strait (Indonesia) using several biological indicators that are important in quantifying fishing pressure. Data on these indicators were collected monthly for three years (2012–2014) in one of the main fishing ports of the area. The results provide evidence that, although SSF would appear to be the most environmentally sustainable of all the fishing techniques being used today in the coastal waters of Indonesia, the impact of SSF fishing on juvenile fishes in certain areas such as the Sunda Strait must not be underestimated. The results also show the need to protect immature fish of species that are not only commercialised but are also important in subsistence fisheries. Although further studies are needed to assess the impact of SSF on fish stocks in the area, it is suggested management recommendations that include the implementation of marine‐protected areas in nursery grounds and establishing minimum landing sizes well above the size‐at‐maturity for each species, are needed.     

Extracellular matrix composition of different spleen compartments of fruit bats

The distribution and composition of extracellular matrix (ECM) of the spleen in two species of fruit bats, namely Cynopterus titthaecheilus and Rousettus leschenaultii, were examined by histochemistry and immunohistochemistry. Reticular fibres accompanied by laminin were identified to make up the splenic stromal network. Types I and III collagen were identified in various spleen compartments with varying intensities. Thin and short elastin fibres were scattered in several parts of the spleen. Visualization of the ECM of the spleen can better demonstrate spleen compartmentalization. The alleged vascular space structure in the fruit bats spleen was the sinus structure that was strengthened by the presence of reticular fibres that limit the sinus basement membrane. The present study identified periellipsoidal lymphoid sheath (PELS)-like structure in fruit bats spleen that had never been identified in mammals before. In addition to describing the structure, this study highlighted the variations in ECM composition of the spleen between species that can provide new insight into the phylogenetic study of spleen morphology.     

Viral-derived DNA invasion and individual variation in an Indonesian population of large flying fox Pteropus vampyrus

Here, we performed next-generation sequencing (NGS) on six large flying foxes (Pteropus vampyrus) collected in Indonesia. Seventy-five virus species in the liver tissue of each specimen were listed. Viral homologous sequences in the bat genome were identified from the listed viruses. This finding provides collateral evidence of viral endogenization into the host genome. We found that two of the six specimens bore partial sequences that were homologous to the plant pathogens Geminiviridae and Luteoviridae. These sequences were absent in the P. vampyrus chromosomal sequences. Hence, plant viral homologous sequences were localized to the hepatocytes as extrachromosomal DNA fragments. Therefore, this suggests that the bat is a potential carrier or vector of plant viruses. The present investigation on wild animals offered novel perspectives on viral invasion, variation, and host interaction.