Object-based forest biomass estimation using Landsat ETM+ in Kampong Thom Province, Cambodia

Information about forest biomass distribution is important for sustainable forest management and monitoring fuelwood supply. The objective of this study is to develop an accurate forest biomass map for Kampong Thom Province, Cambodia. We used a new technique (object-based approach) and a conventional technique (pixel-based approach) for the estimation of forest biomass using Landsat Enhanced Thematic Mapper Plus (ETM+). The object-based approach created segments of images, and calculated statistical and textural attributes. Our results showed that estimation accuracy of the object-based approach, with the use of band 1 and an exponential fit, was the best (R ² = 0.76), and this accuracy was comparable to that of the pixel-based approach (R ² = 0.67). Although several textural variables were related to forest biomass, they did not contribute significantly to improvement of estimation accuracy. However, the object-based method can be used for image segmentation so that the image objects are spectrally more homogeneous within individual regions than with their neighbors. Hence, they can be regarded as management units for policy-related spatial decisions. Therefore, it is possible to select either of the two methods depending upon what the situation demands.     

Unveiling a voluntary farmland registration program to secure open space for risk reduction and post-disaster restoration from earthquakes: lessons learned from practices in Chukyo and Kinki,Japan

Paddy and Water Environment - Because of rapid urbanization, urban agriculture’s capacity to reduce the risks associated with natural disasters has been receiving broad attention. Asian...     

First report of phytophthora rot on <Emphasis Type="Italic">Wasabia japonica</Emphasis> caused by <Emphasis Type="Italic">Phytophthora drechsleri</Emphasis> in Japan

In September 2014, Phytophthora rot on wasabi plants [Wasabia japonica (Miq.) Matsum.] was found for the first time in the city of Okutama, Tokyo, Japan. A Phytophthora sp. strain was constantly isolated from brown stem bases and rhizomes of infected plants. The same symptoms as those observed in the field were produced in vitro through inoculation of test plants with the isolated Phytophthora sp. The fungus was identified as Phytophthora drechsleri based on morphological and DNA sequence comparison. Phytophthora rot, “eki-byo” in Japanese, is proposed for this disease common name.     

Antifungal and antitermitic activities of wood vinegar from oil palm trunk

We evaluated the antifungal and antitermite activities of wood vinegars produced from oil palm trunk. The wood vinegars were produced at three different pyrolysis temperatures, 350, 400, and 450 °C. Antifungal activities of vinegars were evaluated using a Petri dish bioassay with 0.5, 1.0, and 1.5% (v/v) against a white-rot fungus, Trametes versicolor, and a brown-rot fungus, Fomitopsis palustris. Antitermite activities were tested using a no-choice bioassay method for Coptotermes formosanus with 2.5, 5.0, 7.5, and 10.0% (v/v). All the wood vinegars exhibited antifungal activities against T. versicolor. In particular, the wood vinegar produced at 350 °C resulted in complete inhibition of T. versicolor growth at 1.0 and 1.5%. However, higher concentrations were required to obtain growth inhibition of F. palustris. All the wood vinegars exhibited antitermite activity to C. formosanus workers in the no-choice experiment at relatively high concentrations. For instance, 10% concentration was required to achieve 100% mortality against C. formosanus at all production temperatures. The lowest mass loss of the treated filter paper of 11.75% was obtained with a 350 °C—10.0% combination.     

Potential utilization of sodium fluoride (NaF) as a biocide in particleboard production

The feasibility of sodium fluoride (NaF) incorporation as a biocide in the manufacture of particleboard was examined. Laboratory-scale particleboards prepared from untreated wood particles were incorporated with NaF powder at target retentions of 1, 1.5 and 3% of the total particle weight. An in-line treatment method was used to introduce the biocide during the blending stage just before adhesive application. Standard static bending and water resistance (water absorption and thickness swelling) tests indicated that embedding of the powder biocide up to the 3% level did not cause any detrimental effects on mechanical and physical properties. The laboratory decay and termite resistance tests showed that even the lower retention levels of 1 and 1.5% NaF were enough to suppress fungal and termite activity and significantly reduce the mass loss and consumption rate values of the specimens when compared to the untreated controls. Spectrophotometric analysis of leachate waters and the mass losses of the leached specimens revealed the tendency of the NaF to be depleted from the composite specimens. Therefore, the tested biocide was found to be appropriate for interior or protected above-ground outdoor exposure conditions.     

Adjunct ambrisentan therapy had clinical benefits in 5 dogs with sildenafil-refractory pulmonary hypertension

Although sildenafil is used in dogs with severe pulmonary hypertension, they sometimes become resistant and clinical signs deteriorate over time. The objective of this study was to determine the benefits of adjunct ambrisentan therapy in dogs with sildenafil-refractory pulmonary hypertension. In 5 dogs with severe pulmonary hypertension with deteriorating clinical signs despite ongoing sildenafil treatment, adding ambrisentan improved appetite, activity, and respiratory functions. Although peak tricuspid valve regurgitation velocity, as measured by Doppler echocardiography, did not necessarily decrease after ambrisentan administration, there was improved partial pressure of arterial oxygen and the alveolar-arterial oxygen gradient, with no apparent side effects. We concluded that ambrisentan has potential as an adjunct treatment in dogs with pulmonary hypertension that are refractory to sildenafil therapy.Key clinical message:Ambrisentan improved clinical signs in dogs with sildenafil-refractory pulmonary hypertension.     

Estimating the three-dimensional structure of canopy foliage based on the light measurements in a Betula ermanii stand

In order to more accurately evaluate the functional activity of forest stands by canopy production and evapotranspiration, we improved the methods for field measurements and statistical modeling to estimate foliage configuration (spatial distribution of leaves) while simultaneously reconstructing the three-dimensional photosynthetically active photon flux density (PPFD) distribution (PPFD pattern) in a forest canopy. By using a sensor (photodiode) array, a PPFD pattern was observed in summer 2002 under the canopy in an even-aged, pure stand of Japanese mountain birch Betula ermanii Cham. (17-years old) in Hokkaido, northern Japan. A Markov chain Monte Carlo (MCMC) sampling technique is developed such that a set of foliage configurations generated by the model referred to as the Gibbs foliage canopy (GFC) approximates the field-measured PPFD pattern. The posterior distribution of the foliage configurations is generated by the parallel tempering MCMC of eight independent series of foliage configurations. The GFC model generated the posterior distribution of the LAI estimates (mean 4.56) that appeared to be appropriate in comparison to other LAI estimates of the B. ermanii stand based on the indirect and nondestructive methods by LAI-2000 (LAI = 3.43) and litterfall traps (LAI = 5.56) because they could be under- and overestimated, respectively. Our evaluations of the canopy production and evapotranspiration rates suggest that the relationship between LAI and canopy functions was not very simple because it depended on the nonlinear functional forms of the leaf responses of photosynthesis and transpiration to PPFD. The current study demonstrates an application of MCMC techniques that can generate a set of possible structures of unobserved/unobservable objects based on the high-resolution dataset obtained by some indirect (or remote-sensing) methods.     

Changes in plasma prolactin and growth hormone concentrations during freshwater adaptation of juvenile chum salmon (Oncorhynchus keta) reared in seawater for a prolonged period

Freshwater adaptability of chum salmon was examined in juvenile fish reared in seawater for 4 months. The fish, weighing about 40g, were transferred directly to fresh water in October, when their cohorts are migrating in the North Pacific Ocean. Plasma sodium concentration decreased from 167 mM in seawater to about 130 mM during the first 24h, and increased gradually during 2–7 days after the transfer. No immunoreactive prolactin (PRL) was detected in the plasma of the seawater-adapted fish nor during the first 24h in fresh water. Significant levels of PRL were detected after 2–3 days. The maximal level (2.6 ng/ml) was observed after 5 days and became undetectable again after 7 days; no significant correlation was seen between the changes in plasma sodium and PRL levels during the transfer. Plasma growth hormone levels were relatively constant, except for a significant decrease 12h after the transfer. Although plasma thyroxine levels were highly variable during the experiment, a significant decrease and an increase were observed 12h and 5 days after the transfer, respectively. The present study indicates that juvenile chum salmon retain hyperosmoregulatory ability even after prolonged rearing in seawater. Examination of turnover rates, rather than changes in plasma levels, seems to be essential to clarify the osmoregulatory roles of the hormones.     

Odontogenic cysts in three dogs: one odontogenic keratocyst and two dentigerous cysts

Odontogenic cysts, which showed cystic radiolucency in the jaw bone by radiographic examination and computed tomography, were enucleated by operation in 3 dogs. One dog had a odontogenic keratocyst in the incisive bone of the right maxilla and another 2 cases revealed dentigerous cysts in the mandible. These cyst walls were enucleated or transpired by semiconductor laser. Afterwards, osteogenesis was confirmed at the defective part of jaw bone by extirpation of the cyst in all cases, and no recurrence has been noted in any cases. Odontogenic cyst is a disease which should be treated by surgical extirpation or transpiration.